SemaOverload.cpp revision c30614b7e2bad089f2509499379de509f33162d6
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 Compute an implicit conversion sequence for reference 2626/// initialization. 2627static ImplicitConversionSequence 2628TryReferenceInit(Sema &S, Expr *&Init, QualType DeclType, 2629 SourceLocation DeclLoc, 2630 bool SuppressUserConversions, 2631 bool AllowExplicit) { 2632 assert(DeclType->isReferenceType() && "Reference init needs a reference"); 2633 2634 // Most paths end in a failed conversion. 2635 ImplicitConversionSequence ICS; 2636 ICS.setBad(BadConversionSequence::no_conversion, Init, DeclType); 2637 2638 QualType T1 = DeclType->getAs<ReferenceType>()->getPointeeType(); 2639 QualType T2 = Init->getType(); 2640 2641 // If the initializer is the address of an overloaded function, try 2642 // to resolve the overloaded function. If all goes well, T2 is the 2643 // type of the resulting function. 2644 if (S.Context.getCanonicalType(T2) == S.Context.OverloadTy) { 2645 DeclAccessPair Found; 2646 if (FunctionDecl *Fn = S.ResolveAddressOfOverloadedFunction(Init, DeclType, 2647 false, Found)) 2648 T2 = Fn->getType(); 2649 } 2650 2651 // Compute some basic properties of the types and the initializer. 2652 bool isRValRef = DeclType->isRValueReferenceType(); 2653 bool DerivedToBase = false; 2654 Expr::isLvalueResult InitLvalue = Init->isLvalue(S.Context); 2655 Sema::ReferenceCompareResult RefRelationship 2656 = S.CompareReferenceRelationship(DeclLoc, T1, T2, DerivedToBase); 2657 2658 2659 // C++ [over.ics.ref]p3: 2660 // Except for an implicit object parameter, for which see 13.3.1, 2661 // a standard conversion sequence cannot be formed if it requires 2662 // binding an lvalue reference to non-const to an rvalue or 2663 // binding an rvalue reference to an lvalue. 2664 // 2665 // FIXME: DPG doesn't trust this code. It seems far too early to 2666 // abort because of a binding of an rvalue reference to an lvalue. 2667 if (isRValRef && InitLvalue == Expr::LV_Valid) 2668 return ICS; 2669 2670 // C++0x [dcl.init.ref]p16: 2671 // A reference to type "cv1 T1" is initialized by an expression 2672 // of type "cv2 T2" as follows: 2673 2674 // -- If the initializer expression 2675 // -- is an lvalue (but is not a bit-field), and "cv1 T1" is 2676 // reference-compatible with "cv2 T2," or 2677 // 2678 // Per C++ [over.ics.ref]p4, we don't check the bit-field property here. 2679 if (InitLvalue == Expr::LV_Valid && 2680 RefRelationship >= Sema::Ref_Compatible_With_Added_Qualification) { 2681 // C++ [over.ics.ref]p1: 2682 // When a parameter of reference type binds directly (8.5.3) 2683 // to an argument expression, the implicit conversion sequence 2684 // is the identity conversion, unless the argument expression 2685 // has a type that is a derived class of the parameter type, 2686 // in which case the implicit conversion sequence is a 2687 // derived-to-base Conversion (13.3.3.1). 2688 ICS.setStandard(); 2689 ICS.Standard.First = ICK_Identity; 2690 ICS.Standard.Second = DerivedToBase? ICK_Derived_To_Base : ICK_Identity; 2691 ICS.Standard.Third = ICK_Identity; 2692 ICS.Standard.FromTypePtr = T2.getAsOpaquePtr(); 2693 ICS.Standard.setToType(0, T2); 2694 ICS.Standard.setToType(1, T1); 2695 ICS.Standard.setToType(2, T1); 2696 ICS.Standard.ReferenceBinding = true; 2697 ICS.Standard.DirectBinding = true; 2698 ICS.Standard.RRefBinding = false; 2699 ICS.Standard.CopyConstructor = 0; 2700 2701 // Nothing more to do: the inaccessibility/ambiguity check for 2702 // derived-to-base conversions is suppressed when we're 2703 // computing the implicit conversion sequence (C++ 2704 // [over.best.ics]p2). 2705 return ICS; 2706 } 2707 2708 // -- has a class type (i.e., T2 is a class type), where T1 is 2709 // not reference-related to T2, and can be implicitly 2710 // converted to an lvalue of type "cv3 T3," where "cv1 T1" 2711 // is reference-compatible with "cv3 T3" 92) (this 2712 // conversion is selected by enumerating the applicable 2713 // conversion functions (13.3.1.6) and choosing the best 2714 // one through overload resolution (13.3)), 2715 if (!isRValRef && !SuppressUserConversions && T2->isRecordType() && 2716 !S.RequireCompleteType(DeclLoc, T2, 0) && 2717 RefRelationship == Sema::Ref_Incompatible) { 2718 CXXRecordDecl *T2RecordDecl 2719 = dyn_cast<CXXRecordDecl>(T2->getAs<RecordType>()->getDecl()); 2720 2721 OverloadCandidateSet CandidateSet(DeclLoc); 2722 const UnresolvedSetImpl *Conversions 2723 = T2RecordDecl->getVisibleConversionFunctions(); 2724 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 2725 E = Conversions->end(); I != E; ++I) { 2726 NamedDecl *D = *I; 2727 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(D->getDeclContext()); 2728 if (isa<UsingShadowDecl>(D)) 2729 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 2730 2731 FunctionTemplateDecl *ConvTemplate 2732 = dyn_cast<FunctionTemplateDecl>(D); 2733 CXXConversionDecl *Conv; 2734 if (ConvTemplate) 2735 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 2736 else 2737 Conv = cast<CXXConversionDecl>(D); 2738 2739 // If the conversion function doesn't return a reference type, 2740 // it can't be considered for this conversion. 2741 if (Conv->getConversionType()->isLValueReferenceType() && 2742 (AllowExplicit || !Conv->isExplicit())) { 2743 if (ConvTemplate) 2744 S.AddTemplateConversionCandidate(ConvTemplate, I.getPair(), ActingDC, 2745 Init, DeclType, CandidateSet); 2746 else 2747 S.AddConversionCandidate(Conv, I.getPair(), ActingDC, Init, 2748 DeclType, CandidateSet); 2749 } 2750 } 2751 2752 OverloadCandidateSet::iterator Best; 2753 switch (S.BestViableFunction(CandidateSet, DeclLoc, Best)) { 2754 case OR_Success: 2755 // C++ [over.ics.ref]p1: 2756 // 2757 // [...] If the parameter binds directly to the result of 2758 // applying a conversion function to the argument 2759 // expression, the implicit conversion sequence is a 2760 // user-defined conversion sequence (13.3.3.1.2), with the 2761 // second standard conversion sequence either an identity 2762 // conversion or, if the conversion function returns an 2763 // entity of a type that is a derived class of the parameter 2764 // type, a derived-to-base Conversion. 2765 if (!Best->FinalConversion.DirectBinding) 2766 break; 2767 2768 ICS.setUserDefined(); 2769 ICS.UserDefined.Before = Best->Conversions[0].Standard; 2770 ICS.UserDefined.After = Best->FinalConversion; 2771 ICS.UserDefined.ConversionFunction = Best->Function; 2772 ICS.UserDefined.EllipsisConversion = false; 2773 assert(ICS.UserDefined.After.ReferenceBinding && 2774 ICS.UserDefined.After.DirectBinding && 2775 "Expected a direct reference binding!"); 2776 return ICS; 2777 2778 case OR_Ambiguous: 2779 ICS.setAmbiguous(); 2780 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 2781 Cand != CandidateSet.end(); ++Cand) 2782 if (Cand->Viable) 2783 ICS.Ambiguous.addConversion(Cand->Function); 2784 return ICS; 2785 2786 case OR_No_Viable_Function: 2787 case OR_Deleted: 2788 // There was no suitable conversion, or we found a deleted 2789 // conversion; continue with other checks. 2790 break; 2791 } 2792 } 2793 2794 // -- Otherwise, the reference shall be to a non-volatile const 2795 // type (i.e., cv1 shall be const), or the reference shall be an 2796 // rvalue reference and the initializer expression shall be an rvalue. 2797 // 2798 // We actually handle one oddity of C++ [over.ics.ref] at this 2799 // point, which is that, due to p2 (which short-circuits reference 2800 // binding by only attempting a simple conversion for non-direct 2801 // bindings) and p3's strange wording, we allow a const volatile 2802 // reference to bind to an rvalue. Hence the check for the presence 2803 // of "const" rather than checking for "const" being the only 2804 // qualifier. 2805 if (!isRValRef && !T1.isConstQualified()) 2806 return ICS; 2807 2808 // -- if T2 is a class type and 2809 // -- the initializer expression is an rvalue and "cv1 T1" 2810 // is reference-compatible with "cv2 T2," or 2811 // 2812 // -- T1 is not reference-related to T2 and the initializer 2813 // expression can be implicitly converted to an rvalue 2814 // of type "cv3 T3" (this conversion is selected by 2815 // enumerating the applicable conversion functions 2816 // (13.3.1.6) and choosing the best one through overload 2817 // resolution (13.3)), 2818 // 2819 // then the reference is bound to the initializer 2820 // expression rvalue in the first case and to the object 2821 // that is the result of the conversion in the second case 2822 // (or, in either case, to the appropriate base class 2823 // subobject of the object). 2824 // 2825 // We're only checking the first case here, which is a direct 2826 // binding in C++0x but not in C++03. 2827 if (InitLvalue != Expr::LV_Valid && T2->isRecordType() && 2828 RefRelationship >= Sema::Ref_Compatible_With_Added_Qualification) { 2829 ICS.setStandard(); 2830 ICS.Standard.First = ICK_Identity; 2831 ICS.Standard.Second = DerivedToBase? ICK_Derived_To_Base : ICK_Identity; 2832 ICS.Standard.Third = ICK_Identity; 2833 ICS.Standard.FromTypePtr = T2.getAsOpaquePtr(); 2834 ICS.Standard.setToType(0, T2); 2835 ICS.Standard.setToType(1, T1); 2836 ICS.Standard.setToType(2, T1); 2837 ICS.Standard.ReferenceBinding = true; 2838 ICS.Standard.DirectBinding = S.getLangOptions().CPlusPlus0x; 2839 ICS.Standard.RRefBinding = isRValRef; 2840 ICS.Standard.CopyConstructor = 0; 2841 return ICS; 2842 } 2843 2844 // -- Otherwise, a temporary of type "cv1 T1" is created and 2845 // initialized from the initializer expression using the 2846 // rules for a non-reference copy initialization (8.5). The 2847 // reference is then bound to the temporary. If T1 is 2848 // reference-related to T2, cv1 must be the same 2849 // cv-qualification as, or greater cv-qualification than, 2850 // cv2; otherwise, the program is ill-formed. 2851 if (RefRelationship == Sema::Ref_Related) { 2852 // If cv1 == cv2 or cv1 is a greater cv-qualified than cv2, then 2853 // we would be reference-compatible or reference-compatible with 2854 // added qualification. But that wasn't the case, so the reference 2855 // initialization fails. 2856 return ICS; 2857 } 2858 2859 // If at least one of the types is a class type, the types are not 2860 // related, and we aren't allowed any user conversions, the 2861 // reference binding fails. This case is important for breaking 2862 // recursion, since TryImplicitConversion below will attempt to 2863 // create a temporary through the use of a copy constructor. 2864 if (SuppressUserConversions && RefRelationship == Sema::Ref_Incompatible && 2865 (T1->isRecordType() || T2->isRecordType())) 2866 return ICS; 2867 2868 // C++ [over.ics.ref]p2: 2869 // When a parameter of reference type is not bound directly to 2870 // an argument expression, the conversion sequence is the one 2871 // required to convert the argument expression to the 2872 // underlying type of the reference according to 2873 // 13.3.3.1. Conceptually, this conversion sequence corresponds 2874 // to copy-initializing a temporary of the underlying type with 2875 // the argument expression. Any difference in top-level 2876 // cv-qualification is subsumed by the initialization itself 2877 // and does not constitute a conversion. 2878 ICS = S.TryImplicitConversion(Init, T1, SuppressUserConversions, 2879 /*AllowExplicit=*/false, 2880 /*InOverloadResolution=*/false); 2881 2882 // Of course, that's still a reference binding. 2883 if (ICS.isStandard()) { 2884 ICS.Standard.ReferenceBinding = true; 2885 ICS.Standard.RRefBinding = isRValRef; 2886 } else if (ICS.isUserDefined()) { 2887 ICS.UserDefined.After.ReferenceBinding = true; 2888 ICS.UserDefined.After.RRefBinding = isRValRef; 2889 } 2890 return ICS; 2891} 2892 2893/// TryCopyInitialization - Try to copy-initialize a value of type 2894/// ToType from the expression From. Return the implicit conversion 2895/// sequence required to pass this argument, which may be a bad 2896/// conversion sequence (meaning that the argument cannot be passed to 2897/// a parameter of this type). If @p SuppressUserConversions, then we 2898/// do not permit any user-defined conversion sequences. 2899static ImplicitConversionSequence 2900TryCopyInitialization(Sema &S, Expr *From, QualType ToType, 2901 bool SuppressUserConversions, 2902 bool InOverloadResolution) { 2903 if (ToType->isReferenceType()) 2904 return TryReferenceInit(S, From, ToType, 2905 /*FIXME:*/From->getLocStart(), 2906 SuppressUserConversions, 2907 /*AllowExplicit=*/false); 2908 2909 return S.TryImplicitConversion(From, ToType, 2910 SuppressUserConversions, 2911 /*AllowExplicit=*/false, 2912 InOverloadResolution); 2913} 2914 2915/// TryObjectArgumentInitialization - Try to initialize the object 2916/// parameter of the given member function (@c Method) from the 2917/// expression @p From. 2918ImplicitConversionSequence 2919Sema::TryObjectArgumentInitialization(QualType OrigFromType, 2920 CXXMethodDecl *Method, 2921 CXXRecordDecl *ActingContext) { 2922 QualType ClassType = Context.getTypeDeclType(ActingContext); 2923 // [class.dtor]p2: A destructor can be invoked for a const, volatile or 2924 // const volatile object. 2925 unsigned Quals = isa<CXXDestructorDecl>(Method) ? 2926 Qualifiers::Const | Qualifiers::Volatile : Method->getTypeQualifiers(); 2927 QualType ImplicitParamType = Context.getCVRQualifiedType(ClassType, Quals); 2928 2929 // Set up the conversion sequence as a "bad" conversion, to allow us 2930 // to exit early. 2931 ImplicitConversionSequence ICS; 2932 2933 // We need to have an object of class type. 2934 QualType FromType = OrigFromType; 2935 if (const PointerType *PT = FromType->getAs<PointerType>()) 2936 FromType = PT->getPointeeType(); 2937 2938 assert(FromType->isRecordType()); 2939 2940 // The implicit object parameter is has the type "reference to cv X", 2941 // where X is the class of which the function is a member 2942 // (C++ [over.match.funcs]p4). However, when finding an implicit 2943 // conversion sequence for the argument, we are not allowed to 2944 // create temporaries or perform user-defined conversions 2945 // (C++ [over.match.funcs]p5). We perform a simplified version of 2946 // reference binding here, that allows class rvalues to bind to 2947 // non-constant references. 2948 2949 // First check the qualifiers. We don't care about lvalue-vs-rvalue 2950 // with the implicit object parameter (C++ [over.match.funcs]p5). 2951 QualType FromTypeCanon = Context.getCanonicalType(FromType); 2952 if (ImplicitParamType.getCVRQualifiers() 2953 != FromTypeCanon.getLocalCVRQualifiers() && 2954 !ImplicitParamType.isAtLeastAsQualifiedAs(FromTypeCanon)) { 2955 ICS.setBad(BadConversionSequence::bad_qualifiers, 2956 OrigFromType, ImplicitParamType); 2957 return ICS; 2958 } 2959 2960 // Check that we have either the same type or a derived type. It 2961 // affects the conversion rank. 2962 QualType ClassTypeCanon = Context.getCanonicalType(ClassType); 2963 ImplicitConversionKind SecondKind; 2964 if (ClassTypeCanon == FromTypeCanon.getLocalUnqualifiedType()) { 2965 SecondKind = ICK_Identity; 2966 } else if (IsDerivedFrom(FromType, ClassType)) 2967 SecondKind = ICK_Derived_To_Base; 2968 else { 2969 ICS.setBad(BadConversionSequence::unrelated_class, 2970 FromType, ImplicitParamType); 2971 return ICS; 2972 } 2973 2974 // Success. Mark this as a reference binding. 2975 ICS.setStandard(); 2976 ICS.Standard.setAsIdentityConversion(); 2977 ICS.Standard.Second = SecondKind; 2978 ICS.Standard.setFromType(FromType); 2979 ICS.Standard.setAllToTypes(ImplicitParamType); 2980 ICS.Standard.ReferenceBinding = true; 2981 ICS.Standard.DirectBinding = true; 2982 ICS.Standard.RRefBinding = false; 2983 return ICS; 2984} 2985 2986/// PerformObjectArgumentInitialization - Perform initialization of 2987/// the implicit object parameter for the given Method with the given 2988/// expression. 2989bool 2990Sema::PerformObjectArgumentInitialization(Expr *&From, 2991 NestedNameSpecifier *Qualifier, 2992 NamedDecl *FoundDecl, 2993 CXXMethodDecl *Method) { 2994 QualType FromRecordType, DestType; 2995 QualType ImplicitParamRecordType = 2996 Method->getThisType(Context)->getAs<PointerType>()->getPointeeType(); 2997 2998 if (const PointerType *PT = From->getType()->getAs<PointerType>()) { 2999 FromRecordType = PT->getPointeeType(); 3000 DestType = Method->getThisType(Context); 3001 } else { 3002 FromRecordType = From->getType(); 3003 DestType = ImplicitParamRecordType; 3004 } 3005 3006 // Note that we always use the true parent context when performing 3007 // the actual argument initialization. 3008 ImplicitConversionSequence ICS 3009 = TryObjectArgumentInitialization(From->getType(), Method, 3010 Method->getParent()); 3011 if (ICS.isBad()) 3012 return Diag(From->getSourceRange().getBegin(), 3013 diag::err_implicit_object_parameter_init) 3014 << ImplicitParamRecordType << FromRecordType << From->getSourceRange(); 3015 3016 if (ICS.Standard.Second == ICK_Derived_To_Base) 3017 return PerformObjectMemberConversion(From, Qualifier, FoundDecl, Method); 3018 3019 if (!Context.hasSameType(From->getType(), DestType)) 3020 ImpCastExprToType(From, DestType, CastExpr::CK_NoOp, 3021 /*isLvalue=*/!From->getType()->isPointerType()); 3022 return false; 3023} 3024 3025/// TryContextuallyConvertToBool - Attempt to contextually convert the 3026/// expression From to bool (C++0x [conv]p3). 3027ImplicitConversionSequence Sema::TryContextuallyConvertToBool(Expr *From) { 3028 // FIXME: This is pretty broken. 3029 return TryImplicitConversion(From, Context.BoolTy, 3030 // FIXME: Are these flags correct? 3031 /*SuppressUserConversions=*/false, 3032 /*AllowExplicit=*/true, 3033 /*InOverloadResolution=*/false); 3034} 3035 3036/// PerformContextuallyConvertToBool - Perform a contextual conversion 3037/// of the expression From to bool (C++0x [conv]p3). 3038bool Sema::PerformContextuallyConvertToBool(Expr *&From) { 3039 ImplicitConversionSequence ICS = TryContextuallyConvertToBool(From); 3040 if (!ICS.isBad()) 3041 return PerformImplicitConversion(From, Context.BoolTy, ICS, AA_Converting); 3042 3043 if (!DiagnoseMultipleUserDefinedConversion(From, Context.BoolTy)) 3044 return Diag(From->getSourceRange().getBegin(), 3045 diag::err_typecheck_bool_condition) 3046 << From->getType() << From->getSourceRange(); 3047 return true; 3048} 3049 3050/// TryContextuallyConvertToObjCId - Attempt to contextually convert the 3051/// expression From to 'id'. 3052ImplicitConversionSequence Sema::TryContextuallyConvertToObjCId(Expr *From) { 3053 QualType Ty = Context.getObjCIdType(); 3054 return TryImplicitConversion(From, Ty, 3055 // FIXME: Are these flags correct? 3056 /*SuppressUserConversions=*/false, 3057 /*AllowExplicit=*/true, 3058 /*InOverloadResolution=*/false); 3059} 3060 3061/// PerformContextuallyConvertToObjCId - Perform a contextual conversion 3062/// of the expression From to 'id'. 3063bool Sema::PerformContextuallyConvertToObjCId(Expr *&From) { 3064 QualType Ty = Context.getObjCIdType(); 3065 ImplicitConversionSequence ICS = TryContextuallyConvertToObjCId(From); 3066 if (!ICS.isBad()) 3067 return PerformImplicitConversion(From, Ty, ICS, AA_Converting); 3068 return true; 3069} 3070 3071/// \brief Attempt to convert the given expression to an integral or 3072/// enumeration type. 3073/// 3074/// This routine will attempt to convert an expression of class type to an 3075/// integral or enumeration type, if that class type only has a single 3076/// conversion to an integral or enumeration type. 3077/// 3078/// \param From The expression we're converting from. 3079/// 3080/// \returns The expression converted to an integral or enumeration type, 3081/// if successful, or an invalid expression. 3082Sema::OwningExprResult 3083Sema::ConvertToIntegralOrEnumerationType(SourceLocation Loc, ExprArg FromE, 3084 const PartialDiagnostic &NotIntDiag, 3085 const PartialDiagnostic &IncompleteDiag, 3086 const PartialDiagnostic &ExplicitConvDiag, 3087 const PartialDiagnostic &ExplicitConvNote, 3088 const PartialDiagnostic &AmbigDiag, 3089 const PartialDiagnostic &AmbigNote) { 3090 Expr *From = static_cast<Expr *>(FromE.get()); 3091 3092 // We can't perform any more checking for type-dependent expressions. 3093 if (From->isTypeDependent()) 3094 return move(FromE); 3095 3096 // If the expression already has integral or enumeration type, we're golden. 3097 QualType T = From->getType(); 3098 if (T->isIntegralOrEnumerationType()) 3099 return move(FromE); 3100 3101 // FIXME: Check for missing '()' if T is a function type? 3102 3103 // If we don't have a class type in C++, there's no way we can get an 3104 // expression of integral or enumeration type. 3105 const RecordType *RecordTy = T->getAs<RecordType>(); 3106 if (!RecordTy || !getLangOptions().CPlusPlus) { 3107 Diag(Loc, NotIntDiag) 3108 << T << From->getSourceRange(); 3109 return ExprError(); 3110 } 3111 3112 // We must have a complete class type. 3113 if (RequireCompleteType(Loc, T, IncompleteDiag)) 3114 return ExprError(); 3115 3116 // Look for a conversion to an integral or enumeration type. 3117 UnresolvedSet<4> ViableConversions; 3118 UnresolvedSet<4> ExplicitConversions; 3119 const UnresolvedSetImpl *Conversions 3120 = cast<CXXRecordDecl>(RecordTy->getDecl())->getVisibleConversionFunctions(); 3121 3122 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 3123 E = Conversions->end(); 3124 I != E; 3125 ++I) { 3126 if (CXXConversionDecl *Conversion 3127 = dyn_cast<CXXConversionDecl>((*I)->getUnderlyingDecl())) 3128 if (Conversion->getConversionType().getNonReferenceType() 3129 ->isIntegralOrEnumerationType()) { 3130 if (Conversion->isExplicit()) 3131 ExplicitConversions.addDecl(I.getDecl(), I.getAccess()); 3132 else 3133 ViableConversions.addDecl(I.getDecl(), I.getAccess()); 3134 } 3135 } 3136 3137 switch (ViableConversions.size()) { 3138 case 0: 3139 if (ExplicitConversions.size() == 1) { 3140 DeclAccessPair Found = ExplicitConversions[0]; 3141 CXXConversionDecl *Conversion 3142 = cast<CXXConversionDecl>(Found->getUnderlyingDecl()); 3143 3144 // The user probably meant to invoke the given explicit 3145 // conversion; use it. 3146 QualType ConvTy 3147 = Conversion->getConversionType().getNonReferenceType(); 3148 std::string TypeStr; 3149 ConvTy.getAsStringInternal(TypeStr, Context.PrintingPolicy); 3150 3151 Diag(Loc, ExplicitConvDiag) 3152 << T << ConvTy 3153 << FixItHint::CreateInsertion(From->getLocStart(), 3154 "static_cast<" + TypeStr + ">(") 3155 << FixItHint::CreateInsertion(PP.getLocForEndOfToken(From->getLocEnd()), 3156 ")"); 3157 Diag(Conversion->getLocation(), ExplicitConvNote) 3158 << ConvTy->isEnumeralType() << ConvTy; 3159 3160 // If we aren't in a SFINAE context, build a call to the 3161 // explicit conversion function. 3162 if (isSFINAEContext()) 3163 return ExprError(); 3164 3165 CheckMemberOperatorAccess(From->getExprLoc(), From, 0, Found); 3166 From = BuildCXXMemberCallExpr(FromE.takeAs<Expr>(), Found, Conversion); 3167 FromE = Owned(From); 3168 } 3169 3170 // We'll complain below about a non-integral condition type. 3171 break; 3172 3173 case 1: { 3174 // Apply this conversion. 3175 DeclAccessPair Found = ViableConversions[0]; 3176 CheckMemberOperatorAccess(From->getExprLoc(), From, 0, Found); 3177 From = BuildCXXMemberCallExpr(FromE.takeAs<Expr>(), Found, 3178 cast<CXXConversionDecl>(Found->getUnderlyingDecl())); 3179 FromE = Owned(From); 3180 break; 3181 } 3182 3183 default: 3184 Diag(Loc, AmbigDiag) 3185 << T << From->getSourceRange(); 3186 for (unsigned I = 0, N = ViableConversions.size(); I != N; ++I) { 3187 CXXConversionDecl *Conv 3188 = cast<CXXConversionDecl>(ViableConversions[I]->getUnderlyingDecl()); 3189 QualType ConvTy = Conv->getConversionType().getNonReferenceType(); 3190 Diag(Conv->getLocation(), AmbigNote) 3191 << ConvTy->isEnumeralType() << ConvTy; 3192 } 3193 return ExprError(); 3194 } 3195 3196 if (!From->getType()->isIntegralOrEnumerationType()) { 3197 Diag(Loc, NotIntDiag) 3198 << From->getType() << From->getSourceRange(); 3199 return ExprError(); 3200 } 3201 3202 return move(FromE); 3203} 3204 3205/// AddOverloadCandidate - Adds the given function to the set of 3206/// candidate functions, using the given function call arguments. If 3207/// @p SuppressUserConversions, then don't allow user-defined 3208/// conversions via constructors or conversion operators. 3209/// 3210/// \para PartialOverloading true if we are performing "partial" overloading 3211/// based on an incomplete set of function arguments. This feature is used by 3212/// code completion. 3213void 3214Sema::AddOverloadCandidate(FunctionDecl *Function, 3215 DeclAccessPair FoundDecl, 3216 Expr **Args, unsigned NumArgs, 3217 OverloadCandidateSet& CandidateSet, 3218 bool SuppressUserConversions, 3219 bool PartialOverloading) { 3220 const FunctionProtoType* Proto 3221 = dyn_cast<FunctionProtoType>(Function->getType()->getAs<FunctionType>()); 3222 assert(Proto && "Functions without a prototype cannot be overloaded"); 3223 assert(!Function->getDescribedFunctionTemplate() && 3224 "Use AddTemplateOverloadCandidate for function templates"); 3225 3226 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Function)) { 3227 if (!isa<CXXConstructorDecl>(Method)) { 3228 // If we get here, it's because we're calling a member function 3229 // that is named without a member access expression (e.g., 3230 // "this->f") that was either written explicitly or created 3231 // implicitly. This can happen with a qualified call to a member 3232 // function, e.g., X::f(). We use an empty type for the implied 3233 // object argument (C++ [over.call.func]p3), and the acting context 3234 // is irrelevant. 3235 AddMethodCandidate(Method, FoundDecl, Method->getParent(), 3236 QualType(), Args, NumArgs, CandidateSet, 3237 SuppressUserConversions); 3238 return; 3239 } 3240 // We treat a constructor like a non-member function, since its object 3241 // argument doesn't participate in overload resolution. 3242 } 3243 3244 if (!CandidateSet.isNewCandidate(Function)) 3245 return; 3246 3247 // Overload resolution is always an unevaluated context. 3248 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 3249 3250 if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(Function)){ 3251 // C++ [class.copy]p3: 3252 // A member function template is never instantiated to perform the copy 3253 // of a class object to an object of its class type. 3254 QualType ClassType = Context.getTypeDeclType(Constructor->getParent()); 3255 if (NumArgs == 1 && 3256 Constructor->isCopyConstructorLikeSpecialization() && 3257 (Context.hasSameUnqualifiedType(ClassType, Args[0]->getType()) || 3258 IsDerivedFrom(Args[0]->getType(), ClassType))) 3259 return; 3260 } 3261 3262 // Add this candidate 3263 CandidateSet.push_back(OverloadCandidate()); 3264 OverloadCandidate& Candidate = CandidateSet.back(); 3265 Candidate.FoundDecl = FoundDecl; 3266 Candidate.Function = Function; 3267 Candidate.Viable = true; 3268 Candidate.IsSurrogate = false; 3269 Candidate.IgnoreObjectArgument = false; 3270 3271 unsigned NumArgsInProto = Proto->getNumArgs(); 3272 3273 // (C++ 13.3.2p2): A candidate function having fewer than m 3274 // parameters is viable only if it has an ellipsis in its parameter 3275 // list (8.3.5). 3276 if ((NumArgs + (PartialOverloading && NumArgs)) > NumArgsInProto && 3277 !Proto->isVariadic()) { 3278 Candidate.Viable = false; 3279 Candidate.FailureKind = ovl_fail_too_many_arguments; 3280 return; 3281 } 3282 3283 // (C++ 13.3.2p2): A candidate function having more than m parameters 3284 // is viable only if the (m+1)st parameter has a default argument 3285 // (8.3.6). For the purposes of overload resolution, the 3286 // parameter list is truncated on the right, so that there are 3287 // exactly m parameters. 3288 unsigned MinRequiredArgs = Function->getMinRequiredArguments(); 3289 if (NumArgs < MinRequiredArgs && !PartialOverloading) { 3290 // Not enough arguments. 3291 Candidate.Viable = false; 3292 Candidate.FailureKind = ovl_fail_too_few_arguments; 3293 return; 3294 } 3295 3296 // Determine the implicit conversion sequences for each of the 3297 // arguments. 3298 Candidate.Conversions.resize(NumArgs); 3299 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 3300 if (ArgIdx < NumArgsInProto) { 3301 // (C++ 13.3.2p3): for F to be a viable function, there shall 3302 // exist for each argument an implicit conversion sequence 3303 // (13.3.3.1) that converts that argument to the corresponding 3304 // parameter of F. 3305 QualType ParamType = Proto->getArgType(ArgIdx); 3306 Candidate.Conversions[ArgIdx] 3307 = TryCopyInitialization(*this, Args[ArgIdx], ParamType, 3308 SuppressUserConversions, 3309 /*InOverloadResolution=*/true); 3310 if (Candidate.Conversions[ArgIdx].isBad()) { 3311 Candidate.Viable = false; 3312 Candidate.FailureKind = ovl_fail_bad_conversion; 3313 break; 3314 } 3315 } else { 3316 // (C++ 13.3.2p2): For the purposes of overload resolution, any 3317 // argument for which there is no corresponding parameter is 3318 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 3319 Candidate.Conversions[ArgIdx].setEllipsis(); 3320 } 3321 } 3322} 3323 3324/// \brief Add all of the function declarations in the given function set to 3325/// the overload canddiate set. 3326void Sema::AddFunctionCandidates(const UnresolvedSetImpl &Fns, 3327 Expr **Args, unsigned NumArgs, 3328 OverloadCandidateSet& CandidateSet, 3329 bool SuppressUserConversions) { 3330 for (UnresolvedSetIterator F = Fns.begin(), E = Fns.end(); F != E; ++F) { 3331 NamedDecl *D = F.getDecl()->getUnderlyingDecl(); 3332 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { 3333 if (isa<CXXMethodDecl>(FD) && !cast<CXXMethodDecl>(FD)->isStatic()) 3334 AddMethodCandidate(cast<CXXMethodDecl>(FD), F.getPair(), 3335 cast<CXXMethodDecl>(FD)->getParent(), 3336 Args[0]->getType(), Args + 1, NumArgs - 1, 3337 CandidateSet, SuppressUserConversions); 3338 else 3339 AddOverloadCandidate(FD, F.getPair(), Args, NumArgs, CandidateSet, 3340 SuppressUserConversions); 3341 } else { 3342 FunctionTemplateDecl *FunTmpl = cast<FunctionTemplateDecl>(D); 3343 if (isa<CXXMethodDecl>(FunTmpl->getTemplatedDecl()) && 3344 !cast<CXXMethodDecl>(FunTmpl->getTemplatedDecl())->isStatic()) 3345 AddMethodTemplateCandidate(FunTmpl, F.getPair(), 3346 cast<CXXRecordDecl>(FunTmpl->getDeclContext()), 3347 /*FIXME: explicit args */ 0, 3348 Args[0]->getType(), Args + 1, NumArgs - 1, 3349 CandidateSet, 3350 SuppressUserConversions); 3351 else 3352 AddTemplateOverloadCandidate(FunTmpl, F.getPair(), 3353 /*FIXME: explicit args */ 0, 3354 Args, NumArgs, CandidateSet, 3355 SuppressUserConversions); 3356 } 3357 } 3358} 3359 3360/// AddMethodCandidate - Adds a named decl (which is some kind of 3361/// method) as a method candidate to the given overload set. 3362void Sema::AddMethodCandidate(DeclAccessPair FoundDecl, 3363 QualType ObjectType, 3364 Expr **Args, unsigned NumArgs, 3365 OverloadCandidateSet& CandidateSet, 3366 bool SuppressUserConversions) { 3367 NamedDecl *Decl = FoundDecl.getDecl(); 3368 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(Decl->getDeclContext()); 3369 3370 if (isa<UsingShadowDecl>(Decl)) 3371 Decl = cast<UsingShadowDecl>(Decl)->getTargetDecl(); 3372 3373 if (FunctionTemplateDecl *TD = dyn_cast<FunctionTemplateDecl>(Decl)) { 3374 assert(isa<CXXMethodDecl>(TD->getTemplatedDecl()) && 3375 "Expected a member function template"); 3376 AddMethodTemplateCandidate(TD, FoundDecl, ActingContext, 3377 /*ExplicitArgs*/ 0, 3378 ObjectType, Args, NumArgs, 3379 CandidateSet, 3380 SuppressUserConversions); 3381 } else { 3382 AddMethodCandidate(cast<CXXMethodDecl>(Decl), FoundDecl, ActingContext, 3383 ObjectType, Args, NumArgs, 3384 CandidateSet, SuppressUserConversions); 3385 } 3386} 3387 3388/// AddMethodCandidate - Adds the given C++ member function to the set 3389/// of candidate functions, using the given function call arguments 3390/// and the object argument (@c Object). For example, in a call 3391/// @c o.f(a1,a2), @c Object will contain @c o and @c Args will contain 3392/// both @c a1 and @c a2. If @p SuppressUserConversions, then don't 3393/// allow user-defined conversions via constructors or conversion 3394/// operators. 3395void 3396Sema::AddMethodCandidate(CXXMethodDecl *Method, DeclAccessPair FoundDecl, 3397 CXXRecordDecl *ActingContext, QualType ObjectType, 3398 Expr **Args, unsigned NumArgs, 3399 OverloadCandidateSet& CandidateSet, 3400 bool SuppressUserConversions) { 3401 const FunctionProtoType* Proto 3402 = dyn_cast<FunctionProtoType>(Method->getType()->getAs<FunctionType>()); 3403 assert(Proto && "Methods without a prototype cannot be overloaded"); 3404 assert(!isa<CXXConstructorDecl>(Method) && 3405 "Use AddOverloadCandidate for constructors"); 3406 3407 if (!CandidateSet.isNewCandidate(Method)) 3408 return; 3409 3410 // Overload resolution is always an unevaluated context. 3411 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 3412 3413 // Add this candidate 3414 CandidateSet.push_back(OverloadCandidate()); 3415 OverloadCandidate& Candidate = CandidateSet.back(); 3416 Candidate.FoundDecl = FoundDecl; 3417 Candidate.Function = Method; 3418 Candidate.IsSurrogate = false; 3419 Candidate.IgnoreObjectArgument = false; 3420 3421 unsigned NumArgsInProto = Proto->getNumArgs(); 3422 3423 // (C++ 13.3.2p2): A candidate function having fewer than m 3424 // parameters is viable only if it has an ellipsis in its parameter 3425 // list (8.3.5). 3426 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 3427 Candidate.Viable = false; 3428 Candidate.FailureKind = ovl_fail_too_many_arguments; 3429 return; 3430 } 3431 3432 // (C++ 13.3.2p2): A candidate function having more than m parameters 3433 // is viable only if the (m+1)st parameter has a default argument 3434 // (8.3.6). For the purposes of overload resolution, the 3435 // parameter list is truncated on the right, so that there are 3436 // exactly m parameters. 3437 unsigned MinRequiredArgs = Method->getMinRequiredArguments(); 3438 if (NumArgs < MinRequiredArgs) { 3439 // Not enough arguments. 3440 Candidate.Viable = false; 3441 Candidate.FailureKind = ovl_fail_too_few_arguments; 3442 return; 3443 } 3444 3445 Candidate.Viable = true; 3446 Candidate.Conversions.resize(NumArgs + 1); 3447 3448 if (Method->isStatic() || ObjectType.isNull()) 3449 // The implicit object argument is ignored. 3450 Candidate.IgnoreObjectArgument = true; 3451 else { 3452 // Determine the implicit conversion sequence for the object 3453 // parameter. 3454 Candidate.Conversions[0] 3455 = TryObjectArgumentInitialization(ObjectType, Method, ActingContext); 3456 if (Candidate.Conversions[0].isBad()) { 3457 Candidate.Viable = false; 3458 Candidate.FailureKind = ovl_fail_bad_conversion; 3459 return; 3460 } 3461 } 3462 3463 // Determine the implicit conversion sequences for each of the 3464 // arguments. 3465 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 3466 if (ArgIdx < NumArgsInProto) { 3467 // (C++ 13.3.2p3): for F to be a viable function, there shall 3468 // exist for each argument an implicit conversion sequence 3469 // (13.3.3.1) that converts that argument to the corresponding 3470 // parameter of F. 3471 QualType ParamType = Proto->getArgType(ArgIdx); 3472 Candidate.Conversions[ArgIdx + 1] 3473 = TryCopyInitialization(*this, Args[ArgIdx], ParamType, 3474 SuppressUserConversions, 3475 /*InOverloadResolution=*/true); 3476 if (Candidate.Conversions[ArgIdx + 1].isBad()) { 3477 Candidate.Viable = false; 3478 Candidate.FailureKind = ovl_fail_bad_conversion; 3479 break; 3480 } 3481 } else { 3482 // (C++ 13.3.2p2): For the purposes of overload resolution, any 3483 // argument for which there is no corresponding parameter is 3484 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 3485 Candidate.Conversions[ArgIdx + 1].setEllipsis(); 3486 } 3487 } 3488} 3489 3490/// \brief Add a C++ member function template as a candidate to the candidate 3491/// set, using template argument deduction to produce an appropriate member 3492/// function template specialization. 3493void 3494Sema::AddMethodTemplateCandidate(FunctionTemplateDecl *MethodTmpl, 3495 DeclAccessPair FoundDecl, 3496 CXXRecordDecl *ActingContext, 3497 const TemplateArgumentListInfo *ExplicitTemplateArgs, 3498 QualType ObjectType, 3499 Expr **Args, unsigned NumArgs, 3500 OverloadCandidateSet& CandidateSet, 3501 bool SuppressUserConversions) { 3502 if (!CandidateSet.isNewCandidate(MethodTmpl)) 3503 return; 3504 3505 // C++ [over.match.funcs]p7: 3506 // In each case where a candidate is a function template, candidate 3507 // function template specializations are generated using template argument 3508 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 3509 // candidate functions in the usual way.113) A given name can refer to one 3510 // or more function templates and also to a set of overloaded non-template 3511 // functions. In such a case, the candidate functions generated from each 3512 // function template are combined with the set of non-template candidate 3513 // functions. 3514 TemplateDeductionInfo Info(Context, CandidateSet.getLocation()); 3515 FunctionDecl *Specialization = 0; 3516 if (TemplateDeductionResult Result 3517 = DeduceTemplateArguments(MethodTmpl, ExplicitTemplateArgs, 3518 Args, NumArgs, Specialization, Info)) { 3519 CandidateSet.push_back(OverloadCandidate()); 3520 OverloadCandidate &Candidate = CandidateSet.back(); 3521 Candidate.FoundDecl = FoundDecl; 3522 Candidate.Function = MethodTmpl->getTemplatedDecl(); 3523 Candidate.Viable = false; 3524 Candidate.FailureKind = ovl_fail_bad_deduction; 3525 Candidate.IsSurrogate = false; 3526 Candidate.IgnoreObjectArgument = false; 3527 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result, 3528 Info); 3529 return; 3530 } 3531 3532 // Add the function template specialization produced by template argument 3533 // deduction as a candidate. 3534 assert(Specialization && "Missing member function template specialization?"); 3535 assert(isa<CXXMethodDecl>(Specialization) && 3536 "Specialization is not a member function?"); 3537 AddMethodCandidate(cast<CXXMethodDecl>(Specialization), FoundDecl, 3538 ActingContext, ObjectType, Args, NumArgs, 3539 CandidateSet, SuppressUserConversions); 3540} 3541 3542/// \brief Add a C++ function template specialization as a candidate 3543/// in the candidate set, using template argument deduction to produce 3544/// an appropriate function template specialization. 3545void 3546Sema::AddTemplateOverloadCandidate(FunctionTemplateDecl *FunctionTemplate, 3547 DeclAccessPair FoundDecl, 3548 const TemplateArgumentListInfo *ExplicitTemplateArgs, 3549 Expr **Args, unsigned NumArgs, 3550 OverloadCandidateSet& CandidateSet, 3551 bool SuppressUserConversions) { 3552 if (!CandidateSet.isNewCandidate(FunctionTemplate)) 3553 return; 3554 3555 // C++ [over.match.funcs]p7: 3556 // In each case where a candidate is a function template, candidate 3557 // function template specializations are generated using template argument 3558 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 3559 // candidate functions in the usual way.113) A given name can refer to one 3560 // or more function templates and also to a set of overloaded non-template 3561 // functions. In such a case, the candidate functions generated from each 3562 // function template are combined with the set of non-template candidate 3563 // functions. 3564 TemplateDeductionInfo Info(Context, CandidateSet.getLocation()); 3565 FunctionDecl *Specialization = 0; 3566 if (TemplateDeductionResult Result 3567 = DeduceTemplateArguments(FunctionTemplate, ExplicitTemplateArgs, 3568 Args, NumArgs, Specialization, Info)) { 3569 CandidateSet.push_back(OverloadCandidate()); 3570 OverloadCandidate &Candidate = CandidateSet.back(); 3571 Candidate.FoundDecl = FoundDecl; 3572 Candidate.Function = FunctionTemplate->getTemplatedDecl(); 3573 Candidate.Viable = false; 3574 Candidate.FailureKind = ovl_fail_bad_deduction; 3575 Candidate.IsSurrogate = false; 3576 Candidate.IgnoreObjectArgument = false; 3577 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result, 3578 Info); 3579 return; 3580 } 3581 3582 // Add the function template specialization produced by template argument 3583 // deduction as a candidate. 3584 assert(Specialization && "Missing function template specialization?"); 3585 AddOverloadCandidate(Specialization, FoundDecl, Args, NumArgs, CandidateSet, 3586 SuppressUserConversions); 3587} 3588 3589/// AddConversionCandidate - Add a C++ conversion function as a 3590/// candidate in the candidate set (C++ [over.match.conv], 3591/// C++ [over.match.copy]). From is the expression we're converting from, 3592/// and ToType is the type that we're eventually trying to convert to 3593/// (which may or may not be the same type as the type that the 3594/// conversion function produces). 3595void 3596Sema::AddConversionCandidate(CXXConversionDecl *Conversion, 3597 DeclAccessPair FoundDecl, 3598 CXXRecordDecl *ActingContext, 3599 Expr *From, QualType ToType, 3600 OverloadCandidateSet& CandidateSet) { 3601 assert(!Conversion->getDescribedFunctionTemplate() && 3602 "Conversion function templates use AddTemplateConversionCandidate"); 3603 QualType ConvType = Conversion->getConversionType().getNonReferenceType(); 3604 if (!CandidateSet.isNewCandidate(Conversion)) 3605 return; 3606 3607 // Overload resolution is always an unevaluated context. 3608 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 3609 3610 // Add this candidate 3611 CandidateSet.push_back(OverloadCandidate()); 3612 OverloadCandidate& Candidate = CandidateSet.back(); 3613 Candidate.FoundDecl = FoundDecl; 3614 Candidate.Function = Conversion; 3615 Candidate.IsSurrogate = false; 3616 Candidate.IgnoreObjectArgument = false; 3617 Candidate.FinalConversion.setAsIdentityConversion(); 3618 Candidate.FinalConversion.setFromType(ConvType); 3619 Candidate.FinalConversion.setAllToTypes(ToType); 3620 3621 // Determine the implicit conversion sequence for the implicit 3622 // object parameter. 3623 Candidate.Viable = true; 3624 Candidate.Conversions.resize(1); 3625 Candidate.Conversions[0] 3626 = TryObjectArgumentInitialization(From->getType(), Conversion, 3627 ActingContext); 3628 // Conversion functions to a different type in the base class is visible in 3629 // the derived class. So, a derived to base conversion should not participate 3630 // in overload resolution. 3631 if (Candidate.Conversions[0].Standard.Second == ICK_Derived_To_Base) 3632 Candidate.Conversions[0].Standard.Second = ICK_Identity; 3633 if (Candidate.Conversions[0].isBad()) { 3634 Candidate.Viable = false; 3635 Candidate.FailureKind = ovl_fail_bad_conversion; 3636 return; 3637 } 3638 3639 // We won't go through a user-define type conversion function to convert a 3640 // derived to base as such conversions are given Conversion Rank. They only 3641 // go through a copy constructor. 13.3.3.1.2-p4 [over.ics.user] 3642 QualType FromCanon 3643 = Context.getCanonicalType(From->getType().getUnqualifiedType()); 3644 QualType ToCanon = Context.getCanonicalType(ToType).getUnqualifiedType(); 3645 if (FromCanon == ToCanon || IsDerivedFrom(FromCanon, ToCanon)) { 3646 Candidate.Viable = false; 3647 Candidate.FailureKind = ovl_fail_trivial_conversion; 3648 return; 3649 } 3650 3651 // To determine what the conversion from the result of calling the 3652 // conversion function to the type we're eventually trying to 3653 // convert to (ToType), we need to synthesize a call to the 3654 // conversion function and attempt copy initialization from it. This 3655 // makes sure that we get the right semantics with respect to 3656 // lvalues/rvalues and the type. Fortunately, we can allocate this 3657 // call on the stack and we don't need its arguments to be 3658 // well-formed. 3659 DeclRefExpr ConversionRef(Conversion, Conversion->getType(), 3660 From->getLocStart()); 3661 ImplicitCastExpr ConversionFn(Context.getPointerType(Conversion->getType()), 3662 CastExpr::CK_FunctionToPointerDecay, 3663 &ConversionRef, CXXBaseSpecifierArray(), false); 3664 3665 // Note that it is safe to allocate CallExpr on the stack here because 3666 // there are 0 arguments (i.e., nothing is allocated using ASTContext's 3667 // allocator). 3668 CallExpr Call(Context, &ConversionFn, 0, 0, 3669 Conversion->getConversionType().getNonReferenceType(), 3670 From->getLocStart()); 3671 ImplicitConversionSequence ICS = 3672 TryCopyInitialization(*this, &Call, ToType, 3673 /*SuppressUserConversions=*/true, 3674 /*InOverloadResolution=*/false); 3675 3676 switch (ICS.getKind()) { 3677 case ImplicitConversionSequence::StandardConversion: 3678 Candidate.FinalConversion = ICS.Standard; 3679 3680 // C++ [over.ics.user]p3: 3681 // If the user-defined conversion is specified by a specialization of a 3682 // conversion function template, the second standard conversion sequence 3683 // shall have exact match rank. 3684 if (Conversion->getPrimaryTemplate() && 3685 GetConversionRank(ICS.Standard.Second) != ICR_Exact_Match) { 3686 Candidate.Viable = false; 3687 Candidate.FailureKind = ovl_fail_final_conversion_not_exact; 3688 } 3689 3690 break; 3691 3692 case ImplicitConversionSequence::BadConversion: 3693 Candidate.Viable = false; 3694 Candidate.FailureKind = ovl_fail_bad_final_conversion; 3695 break; 3696 3697 default: 3698 assert(false && 3699 "Can only end up with a standard conversion sequence or failure"); 3700 } 3701} 3702 3703/// \brief Adds a conversion function template specialization 3704/// candidate to the overload set, using template argument deduction 3705/// to deduce the template arguments of the conversion function 3706/// template from the type that we are converting to (C++ 3707/// [temp.deduct.conv]). 3708void 3709Sema::AddTemplateConversionCandidate(FunctionTemplateDecl *FunctionTemplate, 3710 DeclAccessPair FoundDecl, 3711 CXXRecordDecl *ActingDC, 3712 Expr *From, QualType ToType, 3713 OverloadCandidateSet &CandidateSet) { 3714 assert(isa<CXXConversionDecl>(FunctionTemplate->getTemplatedDecl()) && 3715 "Only conversion function templates permitted here"); 3716 3717 if (!CandidateSet.isNewCandidate(FunctionTemplate)) 3718 return; 3719 3720 TemplateDeductionInfo Info(Context, CandidateSet.getLocation()); 3721 CXXConversionDecl *Specialization = 0; 3722 if (TemplateDeductionResult Result 3723 = DeduceTemplateArguments(FunctionTemplate, ToType, 3724 Specialization, Info)) { 3725 CandidateSet.push_back(OverloadCandidate()); 3726 OverloadCandidate &Candidate = CandidateSet.back(); 3727 Candidate.FoundDecl = FoundDecl; 3728 Candidate.Function = FunctionTemplate->getTemplatedDecl(); 3729 Candidate.Viable = false; 3730 Candidate.FailureKind = ovl_fail_bad_deduction; 3731 Candidate.IsSurrogate = false; 3732 Candidate.IgnoreObjectArgument = false; 3733 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result, 3734 Info); 3735 return; 3736 } 3737 3738 // Add the conversion function template specialization produced by 3739 // template argument deduction as a candidate. 3740 assert(Specialization && "Missing function template specialization?"); 3741 AddConversionCandidate(Specialization, FoundDecl, ActingDC, From, ToType, 3742 CandidateSet); 3743} 3744 3745/// AddSurrogateCandidate - Adds a "surrogate" candidate function that 3746/// converts the given @c Object to a function pointer via the 3747/// conversion function @c Conversion, and then attempts to call it 3748/// with the given arguments (C++ [over.call.object]p2-4). Proto is 3749/// the type of function that we'll eventually be calling. 3750void Sema::AddSurrogateCandidate(CXXConversionDecl *Conversion, 3751 DeclAccessPair FoundDecl, 3752 CXXRecordDecl *ActingContext, 3753 const FunctionProtoType *Proto, 3754 QualType ObjectType, 3755 Expr **Args, unsigned NumArgs, 3756 OverloadCandidateSet& CandidateSet) { 3757 if (!CandidateSet.isNewCandidate(Conversion)) 3758 return; 3759 3760 // Overload resolution is always an unevaluated context. 3761 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 3762 3763 CandidateSet.push_back(OverloadCandidate()); 3764 OverloadCandidate& Candidate = CandidateSet.back(); 3765 Candidate.FoundDecl = FoundDecl; 3766 Candidate.Function = 0; 3767 Candidate.Surrogate = Conversion; 3768 Candidate.Viable = true; 3769 Candidate.IsSurrogate = true; 3770 Candidate.IgnoreObjectArgument = false; 3771 Candidate.Conversions.resize(NumArgs + 1); 3772 3773 // Determine the implicit conversion sequence for the implicit 3774 // object parameter. 3775 ImplicitConversionSequence ObjectInit 3776 = TryObjectArgumentInitialization(ObjectType, Conversion, ActingContext); 3777 if (ObjectInit.isBad()) { 3778 Candidate.Viable = false; 3779 Candidate.FailureKind = ovl_fail_bad_conversion; 3780 Candidate.Conversions[0] = ObjectInit; 3781 return; 3782 } 3783 3784 // The first conversion is actually a user-defined conversion whose 3785 // first conversion is ObjectInit's standard conversion (which is 3786 // effectively a reference binding). Record it as such. 3787 Candidate.Conversions[0].setUserDefined(); 3788 Candidate.Conversions[0].UserDefined.Before = ObjectInit.Standard; 3789 Candidate.Conversions[0].UserDefined.EllipsisConversion = false; 3790 Candidate.Conversions[0].UserDefined.ConversionFunction = Conversion; 3791 Candidate.Conversions[0].UserDefined.After 3792 = Candidate.Conversions[0].UserDefined.Before; 3793 Candidate.Conversions[0].UserDefined.After.setAsIdentityConversion(); 3794 3795 // Find the 3796 unsigned NumArgsInProto = Proto->getNumArgs(); 3797 3798 // (C++ 13.3.2p2): A candidate function having fewer than m 3799 // parameters is viable only if it has an ellipsis in its parameter 3800 // list (8.3.5). 3801 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 3802 Candidate.Viable = false; 3803 Candidate.FailureKind = ovl_fail_too_many_arguments; 3804 return; 3805 } 3806 3807 // Function types don't have any default arguments, so just check if 3808 // we have enough arguments. 3809 if (NumArgs < NumArgsInProto) { 3810 // Not enough arguments. 3811 Candidate.Viable = false; 3812 Candidate.FailureKind = ovl_fail_too_few_arguments; 3813 return; 3814 } 3815 3816 // Determine the implicit conversion sequences for each of the 3817 // arguments. 3818 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 3819 if (ArgIdx < NumArgsInProto) { 3820 // (C++ 13.3.2p3): for F to be a viable function, there shall 3821 // exist for each argument an implicit conversion sequence 3822 // (13.3.3.1) that converts that argument to the corresponding 3823 // parameter of F. 3824 QualType ParamType = Proto->getArgType(ArgIdx); 3825 Candidate.Conversions[ArgIdx + 1] 3826 = TryCopyInitialization(*this, Args[ArgIdx], ParamType, 3827 /*SuppressUserConversions=*/false, 3828 /*InOverloadResolution=*/false); 3829 if (Candidate.Conversions[ArgIdx + 1].isBad()) { 3830 Candidate.Viable = false; 3831 Candidate.FailureKind = ovl_fail_bad_conversion; 3832 break; 3833 } 3834 } else { 3835 // (C++ 13.3.2p2): For the purposes of overload resolution, any 3836 // argument for which there is no corresponding parameter is 3837 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 3838 Candidate.Conversions[ArgIdx + 1].setEllipsis(); 3839 } 3840 } 3841} 3842 3843/// \brief Add overload candidates for overloaded operators that are 3844/// member functions. 3845/// 3846/// Add the overloaded operator candidates that are member functions 3847/// for the operator Op that was used in an operator expression such 3848/// as "x Op y". , Args/NumArgs provides the operator arguments, and 3849/// CandidateSet will store the added overload candidates. (C++ 3850/// [over.match.oper]). 3851void Sema::AddMemberOperatorCandidates(OverloadedOperatorKind Op, 3852 SourceLocation OpLoc, 3853 Expr **Args, unsigned NumArgs, 3854 OverloadCandidateSet& CandidateSet, 3855 SourceRange OpRange) { 3856 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 3857 3858 // C++ [over.match.oper]p3: 3859 // For a unary operator @ with an operand of a type whose 3860 // cv-unqualified version is T1, and for a binary operator @ with 3861 // a left operand of a type whose cv-unqualified version is T1 and 3862 // a right operand of a type whose cv-unqualified version is T2, 3863 // three sets of candidate functions, designated member 3864 // candidates, non-member candidates and built-in candidates, are 3865 // constructed as follows: 3866 QualType T1 = Args[0]->getType(); 3867 QualType T2; 3868 if (NumArgs > 1) 3869 T2 = Args[1]->getType(); 3870 3871 // -- If T1 is a class type, the set of member candidates is the 3872 // result of the qualified lookup of T1::operator@ 3873 // (13.3.1.1.1); otherwise, the set of member candidates is 3874 // empty. 3875 if (const RecordType *T1Rec = T1->getAs<RecordType>()) { 3876 // Complete the type if it can be completed. Otherwise, we're done. 3877 if (RequireCompleteType(OpLoc, T1, PDiag())) 3878 return; 3879 3880 LookupResult Operators(*this, OpName, OpLoc, LookupOrdinaryName); 3881 LookupQualifiedName(Operators, T1Rec->getDecl()); 3882 Operators.suppressDiagnostics(); 3883 3884 for (LookupResult::iterator Oper = Operators.begin(), 3885 OperEnd = Operators.end(); 3886 Oper != OperEnd; 3887 ++Oper) 3888 AddMethodCandidate(Oper.getPair(), Args[0]->getType(), 3889 Args + 1, NumArgs - 1, CandidateSet, 3890 /* SuppressUserConversions = */ false); 3891 } 3892} 3893 3894/// AddBuiltinCandidate - Add a candidate for a built-in 3895/// operator. ResultTy and ParamTys are the result and parameter types 3896/// of the built-in candidate, respectively. Args and NumArgs are the 3897/// arguments being passed to the candidate. IsAssignmentOperator 3898/// should be true when this built-in candidate is an assignment 3899/// operator. NumContextualBoolArguments is the number of arguments 3900/// (at the beginning of the argument list) that will be contextually 3901/// converted to bool. 3902void Sema::AddBuiltinCandidate(QualType ResultTy, QualType *ParamTys, 3903 Expr **Args, unsigned NumArgs, 3904 OverloadCandidateSet& CandidateSet, 3905 bool IsAssignmentOperator, 3906 unsigned NumContextualBoolArguments) { 3907 // Overload resolution is always an unevaluated context. 3908 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 3909 3910 // Add this candidate 3911 CandidateSet.push_back(OverloadCandidate()); 3912 OverloadCandidate& Candidate = CandidateSet.back(); 3913 Candidate.FoundDecl = DeclAccessPair::make(0, AS_none); 3914 Candidate.Function = 0; 3915 Candidate.IsSurrogate = false; 3916 Candidate.IgnoreObjectArgument = false; 3917 Candidate.BuiltinTypes.ResultTy = ResultTy; 3918 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 3919 Candidate.BuiltinTypes.ParamTypes[ArgIdx] = ParamTys[ArgIdx]; 3920 3921 // Determine the implicit conversion sequences for each of the 3922 // arguments. 3923 Candidate.Viable = true; 3924 Candidate.Conversions.resize(NumArgs); 3925 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 3926 // C++ [over.match.oper]p4: 3927 // For the built-in assignment operators, conversions of the 3928 // left operand are restricted as follows: 3929 // -- no temporaries are introduced to hold the left operand, and 3930 // -- no user-defined conversions are applied to the left 3931 // operand to achieve a type match with the left-most 3932 // parameter of a built-in candidate. 3933 // 3934 // We block these conversions by turning off user-defined 3935 // conversions, since that is the only way that initialization of 3936 // a reference to a non-class type can occur from something that 3937 // is not of the same type. 3938 if (ArgIdx < NumContextualBoolArguments) { 3939 assert(ParamTys[ArgIdx] == Context.BoolTy && 3940 "Contextual conversion to bool requires bool type"); 3941 Candidate.Conversions[ArgIdx] = TryContextuallyConvertToBool(Args[ArgIdx]); 3942 } else { 3943 Candidate.Conversions[ArgIdx] 3944 = TryCopyInitialization(*this, Args[ArgIdx], ParamTys[ArgIdx], 3945 ArgIdx == 0 && IsAssignmentOperator, 3946 /*InOverloadResolution=*/false); 3947 } 3948 if (Candidate.Conversions[ArgIdx].isBad()) { 3949 Candidate.Viable = false; 3950 Candidate.FailureKind = ovl_fail_bad_conversion; 3951 break; 3952 } 3953 } 3954} 3955 3956/// BuiltinCandidateTypeSet - A set of types that will be used for the 3957/// candidate operator functions for built-in operators (C++ 3958/// [over.built]). The types are separated into pointer types and 3959/// enumeration types. 3960class BuiltinCandidateTypeSet { 3961 /// TypeSet - A set of types. 3962 typedef llvm::SmallPtrSet<QualType, 8> TypeSet; 3963 3964 /// PointerTypes - The set of pointer types that will be used in the 3965 /// built-in candidates. 3966 TypeSet PointerTypes; 3967 3968 /// MemberPointerTypes - The set of member pointer types that will be 3969 /// used in the built-in candidates. 3970 TypeSet MemberPointerTypes; 3971 3972 /// EnumerationTypes - The set of enumeration types that will be 3973 /// used in the built-in candidates. 3974 TypeSet EnumerationTypes; 3975 3976 /// \brief The set of vector types that will be used in the built-in 3977 /// candidates. 3978 TypeSet VectorTypes; 3979 3980 /// Sema - The semantic analysis instance where we are building the 3981 /// candidate type set. 3982 Sema &SemaRef; 3983 3984 /// Context - The AST context in which we will build the type sets. 3985 ASTContext &Context; 3986 3987 bool AddPointerWithMoreQualifiedTypeVariants(QualType Ty, 3988 const Qualifiers &VisibleQuals); 3989 bool AddMemberPointerWithMoreQualifiedTypeVariants(QualType Ty); 3990 3991public: 3992 /// iterator - Iterates through the types that are part of the set. 3993 typedef TypeSet::iterator iterator; 3994 3995 BuiltinCandidateTypeSet(Sema &SemaRef) 3996 : SemaRef(SemaRef), Context(SemaRef.Context) { } 3997 3998 void AddTypesConvertedFrom(QualType Ty, 3999 SourceLocation Loc, 4000 bool AllowUserConversions, 4001 bool AllowExplicitConversions, 4002 const Qualifiers &VisibleTypeConversionsQuals); 4003 4004 /// pointer_begin - First pointer type found; 4005 iterator pointer_begin() { return PointerTypes.begin(); } 4006 4007 /// pointer_end - Past the last pointer type found; 4008 iterator pointer_end() { return PointerTypes.end(); } 4009 4010 /// member_pointer_begin - First member pointer type found; 4011 iterator member_pointer_begin() { return MemberPointerTypes.begin(); } 4012 4013 /// member_pointer_end - Past the last member pointer type found; 4014 iterator member_pointer_end() { return MemberPointerTypes.end(); } 4015 4016 /// enumeration_begin - First enumeration type found; 4017 iterator enumeration_begin() { return EnumerationTypes.begin(); } 4018 4019 /// enumeration_end - Past the last enumeration type found; 4020 iterator enumeration_end() { return EnumerationTypes.end(); } 4021 4022 iterator vector_begin() { return VectorTypes.begin(); } 4023 iterator vector_end() { return VectorTypes.end(); } 4024}; 4025 4026/// AddPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty to 4027/// the set of pointer types along with any more-qualified variants of 4028/// that type. For example, if @p Ty is "int const *", this routine 4029/// will add "int const *", "int const volatile *", "int const 4030/// restrict *", and "int const volatile restrict *" to the set of 4031/// pointer types. Returns true if the add of @p Ty itself succeeded, 4032/// false otherwise. 4033/// 4034/// FIXME: what to do about extended qualifiers? 4035bool 4036BuiltinCandidateTypeSet::AddPointerWithMoreQualifiedTypeVariants(QualType Ty, 4037 const Qualifiers &VisibleQuals) { 4038 4039 // Insert this type. 4040 if (!PointerTypes.insert(Ty)) 4041 return false; 4042 4043 const PointerType *PointerTy = Ty->getAs<PointerType>(); 4044 assert(PointerTy && "type was not a pointer type!"); 4045 4046 QualType PointeeTy = PointerTy->getPointeeType(); 4047 // Don't add qualified variants of arrays. For one, they're not allowed 4048 // (the qualifier would sink to the element type), and for another, the 4049 // only overload situation where it matters is subscript or pointer +- int, 4050 // and those shouldn't have qualifier variants anyway. 4051 if (PointeeTy->isArrayType()) 4052 return true; 4053 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 4054 if (const ConstantArrayType *Array =Context.getAsConstantArrayType(PointeeTy)) 4055 BaseCVR = Array->getElementType().getCVRQualifiers(); 4056 bool hasVolatile = VisibleQuals.hasVolatile(); 4057 bool hasRestrict = VisibleQuals.hasRestrict(); 4058 4059 // Iterate through all strict supersets of BaseCVR. 4060 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 4061 if ((CVR | BaseCVR) != CVR) continue; 4062 // Skip over Volatile/Restrict if no Volatile/Restrict found anywhere 4063 // in the types. 4064 if ((CVR & Qualifiers::Volatile) && !hasVolatile) continue; 4065 if ((CVR & Qualifiers::Restrict) && !hasRestrict) continue; 4066 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 4067 PointerTypes.insert(Context.getPointerType(QPointeeTy)); 4068 } 4069 4070 return true; 4071} 4072 4073/// AddMemberPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty 4074/// to the set of pointer types along with any more-qualified variants of 4075/// that type. For example, if @p Ty is "int const *", this routine 4076/// will add "int const *", "int const volatile *", "int const 4077/// restrict *", and "int const volatile restrict *" to the set of 4078/// pointer types. Returns true if the add of @p Ty itself succeeded, 4079/// false otherwise. 4080/// 4081/// FIXME: what to do about extended qualifiers? 4082bool 4083BuiltinCandidateTypeSet::AddMemberPointerWithMoreQualifiedTypeVariants( 4084 QualType Ty) { 4085 // Insert this type. 4086 if (!MemberPointerTypes.insert(Ty)) 4087 return false; 4088 4089 const MemberPointerType *PointerTy = Ty->getAs<MemberPointerType>(); 4090 assert(PointerTy && "type was not a member pointer type!"); 4091 4092 QualType PointeeTy = PointerTy->getPointeeType(); 4093 // Don't add qualified variants of arrays. For one, they're not allowed 4094 // (the qualifier would sink to the element type), and for another, the 4095 // only overload situation where it matters is subscript or pointer +- int, 4096 // and those shouldn't have qualifier variants anyway. 4097 if (PointeeTy->isArrayType()) 4098 return true; 4099 const Type *ClassTy = PointerTy->getClass(); 4100 4101 // Iterate through all strict supersets of the pointee type's CVR 4102 // qualifiers. 4103 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 4104 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 4105 if ((CVR | BaseCVR) != CVR) continue; 4106 4107 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 4108 MemberPointerTypes.insert(Context.getMemberPointerType(QPointeeTy, ClassTy)); 4109 } 4110 4111 return true; 4112} 4113 4114/// AddTypesConvertedFrom - Add each of the types to which the type @p 4115/// Ty can be implicit converted to the given set of @p Types. We're 4116/// primarily interested in pointer types and enumeration types. We also 4117/// take member pointer types, for the conditional operator. 4118/// AllowUserConversions is true if we should look at the conversion 4119/// functions of a class type, and AllowExplicitConversions if we 4120/// should also include the explicit conversion functions of a class 4121/// type. 4122void 4123BuiltinCandidateTypeSet::AddTypesConvertedFrom(QualType Ty, 4124 SourceLocation Loc, 4125 bool AllowUserConversions, 4126 bool AllowExplicitConversions, 4127 const Qualifiers &VisibleQuals) { 4128 // Only deal with canonical types. 4129 Ty = Context.getCanonicalType(Ty); 4130 4131 // Look through reference types; they aren't part of the type of an 4132 // expression for the purposes of conversions. 4133 if (const ReferenceType *RefTy = Ty->getAs<ReferenceType>()) 4134 Ty = RefTy->getPointeeType(); 4135 4136 // We don't care about qualifiers on the type. 4137 Ty = Ty.getLocalUnqualifiedType(); 4138 4139 // If we're dealing with an array type, decay to the pointer. 4140 if (Ty->isArrayType()) 4141 Ty = SemaRef.Context.getArrayDecayedType(Ty); 4142 4143 if (const PointerType *PointerTy = Ty->getAs<PointerType>()) { 4144 QualType PointeeTy = PointerTy->getPointeeType(); 4145 4146 // Insert our type, and its more-qualified variants, into the set 4147 // of types. 4148 if (!AddPointerWithMoreQualifiedTypeVariants(Ty, VisibleQuals)) 4149 return; 4150 } else if (Ty->isMemberPointerType()) { 4151 // Member pointers are far easier, since the pointee can't be converted. 4152 if (!AddMemberPointerWithMoreQualifiedTypeVariants(Ty)) 4153 return; 4154 } else if (Ty->isEnumeralType()) { 4155 EnumerationTypes.insert(Ty); 4156 } else if (Ty->isVectorType()) { 4157 VectorTypes.insert(Ty); 4158 } else if (AllowUserConversions) { 4159 if (const RecordType *TyRec = Ty->getAs<RecordType>()) { 4160 if (SemaRef.RequireCompleteType(Loc, Ty, 0)) { 4161 // No conversion functions in incomplete types. 4162 return; 4163 } 4164 4165 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 4166 const UnresolvedSetImpl *Conversions 4167 = ClassDecl->getVisibleConversionFunctions(); 4168 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 4169 E = Conversions->end(); I != E; ++I) { 4170 NamedDecl *D = I.getDecl(); 4171 if (isa<UsingShadowDecl>(D)) 4172 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 4173 4174 // Skip conversion function templates; they don't tell us anything 4175 // about which builtin types we can convert to. 4176 if (isa<FunctionTemplateDecl>(D)) 4177 continue; 4178 4179 CXXConversionDecl *Conv = cast<CXXConversionDecl>(D); 4180 if (AllowExplicitConversions || !Conv->isExplicit()) { 4181 AddTypesConvertedFrom(Conv->getConversionType(), Loc, false, false, 4182 VisibleQuals); 4183 } 4184 } 4185 } 4186 } 4187} 4188 4189/// \brief Helper function for AddBuiltinOperatorCandidates() that adds 4190/// the volatile- and non-volatile-qualified assignment operators for the 4191/// given type to the candidate set. 4192static void AddBuiltinAssignmentOperatorCandidates(Sema &S, 4193 QualType T, 4194 Expr **Args, 4195 unsigned NumArgs, 4196 OverloadCandidateSet &CandidateSet) { 4197 QualType ParamTypes[2]; 4198 4199 // T& operator=(T&, T) 4200 ParamTypes[0] = S.Context.getLValueReferenceType(T); 4201 ParamTypes[1] = T; 4202 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4203 /*IsAssignmentOperator=*/true); 4204 4205 if (!S.Context.getCanonicalType(T).isVolatileQualified()) { 4206 // volatile T& operator=(volatile T&, T) 4207 ParamTypes[0] 4208 = S.Context.getLValueReferenceType(S.Context.getVolatileType(T)); 4209 ParamTypes[1] = T; 4210 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4211 /*IsAssignmentOperator=*/true); 4212 } 4213} 4214 4215/// CollectVRQualifiers - This routine returns Volatile/Restrict qualifiers, 4216/// if any, found in visible type conversion functions found in ArgExpr's type. 4217static Qualifiers CollectVRQualifiers(ASTContext &Context, Expr* ArgExpr) { 4218 Qualifiers VRQuals; 4219 const RecordType *TyRec; 4220 if (const MemberPointerType *RHSMPType = 4221 ArgExpr->getType()->getAs<MemberPointerType>()) 4222 TyRec = RHSMPType->getClass()->getAs<RecordType>(); 4223 else 4224 TyRec = ArgExpr->getType()->getAs<RecordType>(); 4225 if (!TyRec) { 4226 // Just to be safe, assume the worst case. 4227 VRQuals.addVolatile(); 4228 VRQuals.addRestrict(); 4229 return VRQuals; 4230 } 4231 4232 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 4233 if (!ClassDecl->hasDefinition()) 4234 return VRQuals; 4235 4236 const UnresolvedSetImpl *Conversions = 4237 ClassDecl->getVisibleConversionFunctions(); 4238 4239 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 4240 E = Conversions->end(); I != E; ++I) { 4241 NamedDecl *D = I.getDecl(); 4242 if (isa<UsingShadowDecl>(D)) 4243 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 4244 if (CXXConversionDecl *Conv = dyn_cast<CXXConversionDecl>(D)) { 4245 QualType CanTy = Context.getCanonicalType(Conv->getConversionType()); 4246 if (const ReferenceType *ResTypeRef = CanTy->getAs<ReferenceType>()) 4247 CanTy = ResTypeRef->getPointeeType(); 4248 // Need to go down the pointer/mempointer chain and add qualifiers 4249 // as see them. 4250 bool done = false; 4251 while (!done) { 4252 if (const PointerType *ResTypePtr = CanTy->getAs<PointerType>()) 4253 CanTy = ResTypePtr->getPointeeType(); 4254 else if (const MemberPointerType *ResTypeMPtr = 4255 CanTy->getAs<MemberPointerType>()) 4256 CanTy = ResTypeMPtr->getPointeeType(); 4257 else 4258 done = true; 4259 if (CanTy.isVolatileQualified()) 4260 VRQuals.addVolatile(); 4261 if (CanTy.isRestrictQualified()) 4262 VRQuals.addRestrict(); 4263 if (VRQuals.hasRestrict() && VRQuals.hasVolatile()) 4264 return VRQuals; 4265 } 4266 } 4267 } 4268 return VRQuals; 4269} 4270 4271/// AddBuiltinOperatorCandidates - Add the appropriate built-in 4272/// operator overloads to the candidate set (C++ [over.built]), based 4273/// on the operator @p Op and the arguments given. For example, if the 4274/// operator is a binary '+', this routine might add "int 4275/// operator+(int, int)" to cover integer addition. 4276void 4277Sema::AddBuiltinOperatorCandidates(OverloadedOperatorKind Op, 4278 SourceLocation OpLoc, 4279 Expr **Args, unsigned NumArgs, 4280 OverloadCandidateSet& CandidateSet) { 4281 // The set of "promoted arithmetic types", which are the arithmetic 4282 // types are that preserved by promotion (C++ [over.built]p2). Note 4283 // that the first few of these types are the promoted integral 4284 // types; these types need to be first. 4285 // FIXME: What about complex? 4286 const unsigned FirstIntegralType = 0; 4287 const unsigned LastIntegralType = 13; 4288 const unsigned FirstPromotedIntegralType = 7, 4289 LastPromotedIntegralType = 13; 4290 const unsigned FirstPromotedArithmeticType = 7, 4291 LastPromotedArithmeticType = 16; 4292 const unsigned NumArithmeticTypes = 16; 4293 QualType ArithmeticTypes[NumArithmeticTypes] = { 4294 Context.BoolTy, Context.CharTy, Context.WCharTy, 4295// FIXME: Context.Char16Ty, Context.Char32Ty, 4296 Context.SignedCharTy, Context.ShortTy, 4297 Context.UnsignedCharTy, Context.UnsignedShortTy, 4298 Context.IntTy, Context.LongTy, Context.LongLongTy, 4299 Context.UnsignedIntTy, Context.UnsignedLongTy, Context.UnsignedLongLongTy, 4300 Context.FloatTy, Context.DoubleTy, Context.LongDoubleTy 4301 }; 4302 assert(ArithmeticTypes[FirstPromotedIntegralType] == Context.IntTy && 4303 "Invalid first promoted integral type"); 4304 assert(ArithmeticTypes[LastPromotedIntegralType - 1] 4305 == Context.UnsignedLongLongTy && 4306 "Invalid last promoted integral type"); 4307 assert(ArithmeticTypes[FirstPromotedArithmeticType] == Context.IntTy && 4308 "Invalid first promoted arithmetic type"); 4309 assert(ArithmeticTypes[LastPromotedArithmeticType - 1] 4310 == Context.LongDoubleTy && 4311 "Invalid last promoted arithmetic type"); 4312 4313 // Find all of the types that the arguments can convert to, but only 4314 // if the operator we're looking at has built-in operator candidates 4315 // that make use of these types. 4316 Qualifiers VisibleTypeConversionsQuals; 4317 VisibleTypeConversionsQuals.addConst(); 4318 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 4319 VisibleTypeConversionsQuals += CollectVRQualifiers(Context, Args[ArgIdx]); 4320 4321 BuiltinCandidateTypeSet CandidateTypes(*this); 4322 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 4323 CandidateTypes.AddTypesConvertedFrom(Args[ArgIdx]->getType(), 4324 OpLoc, 4325 true, 4326 (Op == OO_Exclaim || 4327 Op == OO_AmpAmp || 4328 Op == OO_PipePipe), 4329 VisibleTypeConversionsQuals); 4330 4331 bool isComparison = false; 4332 switch (Op) { 4333 case OO_None: 4334 case NUM_OVERLOADED_OPERATORS: 4335 assert(false && "Expected an overloaded operator"); 4336 break; 4337 4338 case OO_Star: // '*' is either unary or binary 4339 if (NumArgs == 1) 4340 goto UnaryStar; 4341 else 4342 goto BinaryStar; 4343 break; 4344 4345 case OO_Plus: // '+' is either unary or binary 4346 if (NumArgs == 1) 4347 goto UnaryPlus; 4348 else 4349 goto BinaryPlus; 4350 break; 4351 4352 case OO_Minus: // '-' is either unary or binary 4353 if (NumArgs == 1) 4354 goto UnaryMinus; 4355 else 4356 goto BinaryMinus; 4357 break; 4358 4359 case OO_Amp: // '&' is either unary or binary 4360 if (NumArgs == 1) 4361 goto UnaryAmp; 4362 else 4363 goto BinaryAmp; 4364 4365 case OO_PlusPlus: 4366 case OO_MinusMinus: 4367 // C++ [over.built]p3: 4368 // 4369 // For every pair (T, VQ), where T is an arithmetic type, and VQ 4370 // is either volatile or empty, there exist candidate operator 4371 // functions of the form 4372 // 4373 // VQ T& operator++(VQ T&); 4374 // T operator++(VQ T&, int); 4375 // 4376 // C++ [over.built]p4: 4377 // 4378 // For every pair (T, VQ), where T is an arithmetic type other 4379 // than bool, and VQ is either volatile or empty, there exist 4380 // candidate operator functions of the form 4381 // 4382 // VQ T& operator--(VQ T&); 4383 // T operator--(VQ T&, int); 4384 for (unsigned Arith = (Op == OO_PlusPlus? 0 : 1); 4385 Arith < NumArithmeticTypes; ++Arith) { 4386 QualType ArithTy = ArithmeticTypes[Arith]; 4387 QualType ParamTypes[2] 4388 = { Context.getLValueReferenceType(ArithTy), Context.IntTy }; 4389 4390 // Non-volatile version. 4391 if (NumArgs == 1) 4392 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 4393 else 4394 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 4395 // heuristic to reduce number of builtin candidates in the set. 4396 // Add volatile version only if there are conversions to a volatile type. 4397 if (VisibleTypeConversionsQuals.hasVolatile()) { 4398 // Volatile version 4399 ParamTypes[0] 4400 = Context.getLValueReferenceType(Context.getVolatileType(ArithTy)); 4401 if (NumArgs == 1) 4402 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 4403 else 4404 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 4405 } 4406 } 4407 4408 // C++ [over.built]p5: 4409 // 4410 // For every pair (T, VQ), where T is a cv-qualified or 4411 // cv-unqualified object type, and VQ is either volatile or 4412 // empty, there exist candidate operator functions of the form 4413 // 4414 // T*VQ& operator++(T*VQ&); 4415 // T*VQ& operator--(T*VQ&); 4416 // T* operator++(T*VQ&, int); 4417 // T* operator--(T*VQ&, int); 4418 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 4419 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4420 // Skip pointer types that aren't pointers to object types. 4421 if (!(*Ptr)->getAs<PointerType>()->getPointeeType()->isObjectType()) 4422 continue; 4423 4424 QualType ParamTypes[2] = { 4425 Context.getLValueReferenceType(*Ptr), Context.IntTy 4426 }; 4427 4428 // Without volatile 4429 if (NumArgs == 1) 4430 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 4431 else 4432 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 4433 4434 if (!Context.getCanonicalType(*Ptr).isVolatileQualified() && 4435 VisibleTypeConversionsQuals.hasVolatile()) { 4436 // With volatile 4437 ParamTypes[0] 4438 = Context.getLValueReferenceType(Context.getVolatileType(*Ptr)); 4439 if (NumArgs == 1) 4440 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 4441 else 4442 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 4443 } 4444 } 4445 break; 4446 4447 UnaryStar: 4448 // C++ [over.built]p6: 4449 // For every cv-qualified or cv-unqualified object type T, there 4450 // exist candidate operator functions of the form 4451 // 4452 // T& operator*(T*); 4453 // 4454 // C++ [over.built]p7: 4455 // For every function type T, there exist candidate operator 4456 // functions of the form 4457 // T& operator*(T*); 4458 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 4459 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4460 QualType ParamTy = *Ptr; 4461 QualType PointeeTy = ParamTy->getAs<PointerType>()->getPointeeType(); 4462 AddBuiltinCandidate(Context.getLValueReferenceType(PointeeTy), 4463 &ParamTy, Args, 1, CandidateSet); 4464 } 4465 break; 4466 4467 UnaryPlus: 4468 // C++ [over.built]p8: 4469 // For every type T, there exist candidate operator functions of 4470 // the form 4471 // 4472 // T* operator+(T*); 4473 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 4474 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4475 QualType ParamTy = *Ptr; 4476 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet); 4477 } 4478 4479 // Fall through 4480 4481 UnaryMinus: 4482 // C++ [over.built]p9: 4483 // For every promoted arithmetic type T, there exist candidate 4484 // operator functions of the form 4485 // 4486 // T operator+(T); 4487 // T operator-(T); 4488 for (unsigned Arith = FirstPromotedArithmeticType; 4489 Arith < LastPromotedArithmeticType; ++Arith) { 4490 QualType ArithTy = ArithmeticTypes[Arith]; 4491 AddBuiltinCandidate(ArithTy, &ArithTy, Args, 1, CandidateSet); 4492 } 4493 4494 // Extension: We also add these operators for vector types. 4495 for (BuiltinCandidateTypeSet::iterator Vec = CandidateTypes.vector_begin(), 4496 VecEnd = CandidateTypes.vector_end(); 4497 Vec != VecEnd; ++Vec) { 4498 QualType VecTy = *Vec; 4499 AddBuiltinCandidate(VecTy, &VecTy, Args, 1, CandidateSet); 4500 } 4501 break; 4502 4503 case OO_Tilde: 4504 // C++ [over.built]p10: 4505 // For every promoted integral type T, there exist candidate 4506 // operator functions of the form 4507 // 4508 // T operator~(T); 4509 for (unsigned Int = FirstPromotedIntegralType; 4510 Int < LastPromotedIntegralType; ++Int) { 4511 QualType IntTy = ArithmeticTypes[Int]; 4512 AddBuiltinCandidate(IntTy, &IntTy, Args, 1, CandidateSet); 4513 } 4514 4515 // Extension: We also add this operator for vector types. 4516 for (BuiltinCandidateTypeSet::iterator Vec = CandidateTypes.vector_begin(), 4517 VecEnd = CandidateTypes.vector_end(); 4518 Vec != VecEnd; ++Vec) { 4519 QualType VecTy = *Vec; 4520 AddBuiltinCandidate(VecTy, &VecTy, Args, 1, CandidateSet); 4521 } 4522 break; 4523 4524 case OO_New: 4525 case OO_Delete: 4526 case OO_Array_New: 4527 case OO_Array_Delete: 4528 case OO_Call: 4529 assert(false && "Special operators don't use AddBuiltinOperatorCandidates"); 4530 break; 4531 4532 case OO_Comma: 4533 UnaryAmp: 4534 case OO_Arrow: 4535 // C++ [over.match.oper]p3: 4536 // -- For the operator ',', the unary operator '&', or the 4537 // operator '->', the built-in candidates set is empty. 4538 break; 4539 4540 case OO_EqualEqual: 4541 case OO_ExclaimEqual: 4542 // C++ [over.match.oper]p16: 4543 // For every pointer to member type T, there exist candidate operator 4544 // functions of the form 4545 // 4546 // bool operator==(T,T); 4547 // bool operator!=(T,T); 4548 for (BuiltinCandidateTypeSet::iterator 4549 MemPtr = CandidateTypes.member_pointer_begin(), 4550 MemPtrEnd = CandidateTypes.member_pointer_end(); 4551 MemPtr != MemPtrEnd; 4552 ++MemPtr) { 4553 QualType ParamTypes[2] = { *MemPtr, *MemPtr }; 4554 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 4555 } 4556 4557 // Fall through 4558 4559 case OO_Less: 4560 case OO_Greater: 4561 case OO_LessEqual: 4562 case OO_GreaterEqual: 4563 // C++ [over.built]p15: 4564 // 4565 // For every pointer or enumeration type T, there exist 4566 // candidate operator functions of the form 4567 // 4568 // bool operator<(T, T); 4569 // bool operator>(T, T); 4570 // bool operator<=(T, T); 4571 // bool operator>=(T, T); 4572 // bool operator==(T, T); 4573 // bool operator!=(T, T); 4574 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 4575 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4576 QualType ParamTypes[2] = { *Ptr, *Ptr }; 4577 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 4578 } 4579 for (BuiltinCandidateTypeSet::iterator Enum 4580 = CandidateTypes.enumeration_begin(); 4581 Enum != CandidateTypes.enumeration_end(); ++Enum) { 4582 QualType ParamTypes[2] = { *Enum, *Enum }; 4583 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 4584 } 4585 4586 // Fall through. 4587 isComparison = true; 4588 4589 BinaryPlus: 4590 BinaryMinus: 4591 if (!isComparison) { 4592 // We didn't fall through, so we must have OO_Plus or OO_Minus. 4593 4594 // C++ [over.built]p13: 4595 // 4596 // For every cv-qualified or cv-unqualified object type T 4597 // there exist candidate operator functions of the form 4598 // 4599 // T* operator+(T*, ptrdiff_t); 4600 // T& operator[](T*, ptrdiff_t); [BELOW] 4601 // T* operator-(T*, ptrdiff_t); 4602 // T* operator+(ptrdiff_t, T*); 4603 // T& operator[](ptrdiff_t, T*); [BELOW] 4604 // 4605 // C++ [over.built]p14: 4606 // 4607 // For every T, where T is a pointer to object type, there 4608 // exist candidate operator functions of the form 4609 // 4610 // ptrdiff_t operator-(T, T); 4611 for (BuiltinCandidateTypeSet::iterator Ptr 4612 = CandidateTypes.pointer_begin(); 4613 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4614 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 4615 4616 // operator+(T*, ptrdiff_t) or operator-(T*, ptrdiff_t) 4617 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 4618 4619 if (Op == OO_Plus) { 4620 // T* operator+(ptrdiff_t, T*); 4621 ParamTypes[0] = ParamTypes[1]; 4622 ParamTypes[1] = *Ptr; 4623 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 4624 } else { 4625 // ptrdiff_t operator-(T, T); 4626 ParamTypes[1] = *Ptr; 4627 AddBuiltinCandidate(Context.getPointerDiffType(), ParamTypes, 4628 Args, 2, CandidateSet); 4629 } 4630 } 4631 } 4632 // Fall through 4633 4634 case OO_Slash: 4635 BinaryStar: 4636 Conditional: 4637 // C++ [over.built]p12: 4638 // 4639 // For every pair of promoted arithmetic types L and R, there 4640 // exist candidate operator functions of the form 4641 // 4642 // LR operator*(L, R); 4643 // LR operator/(L, R); 4644 // LR operator+(L, R); 4645 // LR operator-(L, R); 4646 // bool operator<(L, R); 4647 // bool operator>(L, R); 4648 // bool operator<=(L, R); 4649 // bool operator>=(L, R); 4650 // bool operator==(L, R); 4651 // bool operator!=(L, R); 4652 // 4653 // where LR is the result of the usual arithmetic conversions 4654 // between types L and R. 4655 // 4656 // C++ [over.built]p24: 4657 // 4658 // For every pair of promoted arithmetic types L and R, there exist 4659 // candidate operator functions of the form 4660 // 4661 // LR operator?(bool, L, R); 4662 // 4663 // where LR is the result of the usual arithmetic conversions 4664 // between types L and R. 4665 // Our candidates ignore the first parameter. 4666 for (unsigned Left = FirstPromotedArithmeticType; 4667 Left < LastPromotedArithmeticType; ++Left) { 4668 for (unsigned Right = FirstPromotedArithmeticType; 4669 Right < LastPromotedArithmeticType; ++Right) { 4670 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 4671 QualType Result 4672 = isComparison 4673 ? Context.BoolTy 4674 : Context.UsualArithmeticConversionsType(LandR[0], LandR[1]); 4675 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 4676 } 4677 } 4678 4679 // Extension: Add the binary operators ==, !=, <, <=, >=, >, *, /, and the 4680 // conditional operator for vector types. 4681 for (BuiltinCandidateTypeSet::iterator Vec1 = CandidateTypes.vector_begin(), 4682 Vec1End = CandidateTypes.vector_end(); 4683 Vec1 != Vec1End; ++Vec1) 4684 for (BuiltinCandidateTypeSet::iterator 4685 Vec2 = CandidateTypes.vector_begin(), 4686 Vec2End = CandidateTypes.vector_end(); 4687 Vec2 != Vec2End; ++Vec2) { 4688 QualType LandR[2] = { *Vec1, *Vec2 }; 4689 QualType Result; 4690 if (isComparison) 4691 Result = Context.BoolTy; 4692 else { 4693 if ((*Vec1)->isExtVectorType() || !(*Vec2)->isExtVectorType()) 4694 Result = *Vec1; 4695 else 4696 Result = *Vec2; 4697 } 4698 4699 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 4700 } 4701 4702 break; 4703 4704 case OO_Percent: 4705 BinaryAmp: 4706 case OO_Caret: 4707 case OO_Pipe: 4708 case OO_LessLess: 4709 case OO_GreaterGreater: 4710 // C++ [over.built]p17: 4711 // 4712 // For every pair of promoted integral types L and R, there 4713 // exist candidate operator functions of the form 4714 // 4715 // LR operator%(L, R); 4716 // LR operator&(L, R); 4717 // LR operator^(L, R); 4718 // LR operator|(L, R); 4719 // L operator<<(L, R); 4720 // L operator>>(L, R); 4721 // 4722 // where LR is the result of the usual arithmetic conversions 4723 // between types L and R. 4724 for (unsigned Left = FirstPromotedIntegralType; 4725 Left < LastPromotedIntegralType; ++Left) { 4726 for (unsigned Right = FirstPromotedIntegralType; 4727 Right < LastPromotedIntegralType; ++Right) { 4728 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 4729 QualType Result = (Op == OO_LessLess || Op == OO_GreaterGreater) 4730 ? LandR[0] 4731 : Context.UsualArithmeticConversionsType(LandR[0], LandR[1]); 4732 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 4733 } 4734 } 4735 break; 4736 4737 case OO_Equal: 4738 // C++ [over.built]p20: 4739 // 4740 // For every pair (T, VQ), where T is an enumeration or 4741 // pointer to member type and VQ is either volatile or 4742 // empty, there exist candidate operator functions of the form 4743 // 4744 // VQ T& operator=(VQ T&, T); 4745 for (BuiltinCandidateTypeSet::iterator 4746 Enum = CandidateTypes.enumeration_begin(), 4747 EnumEnd = CandidateTypes.enumeration_end(); 4748 Enum != EnumEnd; ++Enum) 4749 AddBuiltinAssignmentOperatorCandidates(*this, *Enum, Args, 2, 4750 CandidateSet); 4751 for (BuiltinCandidateTypeSet::iterator 4752 MemPtr = CandidateTypes.member_pointer_begin(), 4753 MemPtrEnd = CandidateTypes.member_pointer_end(); 4754 MemPtr != MemPtrEnd; ++MemPtr) 4755 AddBuiltinAssignmentOperatorCandidates(*this, *MemPtr, Args, 2, 4756 CandidateSet); 4757 4758 // Fall through. 4759 4760 case OO_PlusEqual: 4761 case OO_MinusEqual: 4762 // C++ [over.built]p19: 4763 // 4764 // For every pair (T, VQ), where T is any type and VQ is either 4765 // volatile or empty, there exist candidate operator functions 4766 // of the form 4767 // 4768 // T*VQ& operator=(T*VQ&, T*); 4769 // 4770 // C++ [over.built]p21: 4771 // 4772 // For every pair (T, VQ), where T is a cv-qualified or 4773 // cv-unqualified object type and VQ is either volatile or 4774 // empty, there exist candidate operator functions of the form 4775 // 4776 // T*VQ& operator+=(T*VQ&, ptrdiff_t); 4777 // T*VQ& operator-=(T*VQ&, ptrdiff_t); 4778 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 4779 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4780 QualType ParamTypes[2]; 4781 ParamTypes[1] = (Op == OO_Equal)? *Ptr : Context.getPointerDiffType(); 4782 4783 // non-volatile version 4784 ParamTypes[0] = Context.getLValueReferenceType(*Ptr); 4785 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4786 /*IsAssigmentOperator=*/Op == OO_Equal); 4787 4788 if (!Context.getCanonicalType(*Ptr).isVolatileQualified() && 4789 VisibleTypeConversionsQuals.hasVolatile()) { 4790 // volatile version 4791 ParamTypes[0] 4792 = Context.getLValueReferenceType(Context.getVolatileType(*Ptr)); 4793 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4794 /*IsAssigmentOperator=*/Op == OO_Equal); 4795 } 4796 } 4797 // Fall through. 4798 4799 case OO_StarEqual: 4800 case OO_SlashEqual: 4801 // C++ [over.built]p18: 4802 // 4803 // For every triple (L, VQ, R), where L is an arithmetic type, 4804 // VQ is either volatile or empty, and R is a promoted 4805 // arithmetic type, there exist candidate operator functions of 4806 // the form 4807 // 4808 // VQ L& operator=(VQ L&, R); 4809 // VQ L& operator*=(VQ L&, R); 4810 // VQ L& operator/=(VQ L&, R); 4811 // VQ L& operator+=(VQ L&, R); 4812 // VQ L& operator-=(VQ L&, R); 4813 for (unsigned Left = 0; Left < NumArithmeticTypes; ++Left) { 4814 for (unsigned Right = FirstPromotedArithmeticType; 4815 Right < LastPromotedArithmeticType; ++Right) { 4816 QualType ParamTypes[2]; 4817 ParamTypes[1] = ArithmeticTypes[Right]; 4818 4819 // Add this built-in operator as a candidate (VQ is empty). 4820 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 4821 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4822 /*IsAssigmentOperator=*/Op == OO_Equal); 4823 4824 // Add this built-in operator as a candidate (VQ is 'volatile'). 4825 if (VisibleTypeConversionsQuals.hasVolatile()) { 4826 ParamTypes[0] = Context.getVolatileType(ArithmeticTypes[Left]); 4827 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 4828 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4829 /*IsAssigmentOperator=*/Op == OO_Equal); 4830 } 4831 } 4832 } 4833 4834 // Extension: Add the binary operators =, +=, -=, *=, /= for vector types. 4835 for (BuiltinCandidateTypeSet::iterator Vec1 = CandidateTypes.vector_begin(), 4836 Vec1End = CandidateTypes.vector_end(); 4837 Vec1 != Vec1End; ++Vec1) 4838 for (BuiltinCandidateTypeSet::iterator 4839 Vec2 = CandidateTypes.vector_begin(), 4840 Vec2End = CandidateTypes.vector_end(); 4841 Vec2 != Vec2End; ++Vec2) { 4842 QualType ParamTypes[2]; 4843 ParamTypes[1] = *Vec2; 4844 // Add this built-in operator as a candidate (VQ is empty). 4845 ParamTypes[0] = Context.getLValueReferenceType(*Vec1); 4846 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4847 /*IsAssigmentOperator=*/Op == OO_Equal); 4848 4849 // Add this built-in operator as a candidate (VQ is 'volatile'). 4850 if (VisibleTypeConversionsQuals.hasVolatile()) { 4851 ParamTypes[0] = Context.getVolatileType(*Vec1); 4852 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 4853 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4854 /*IsAssigmentOperator=*/Op == OO_Equal); 4855 } 4856 } 4857 break; 4858 4859 case OO_PercentEqual: 4860 case OO_LessLessEqual: 4861 case OO_GreaterGreaterEqual: 4862 case OO_AmpEqual: 4863 case OO_CaretEqual: 4864 case OO_PipeEqual: 4865 // C++ [over.built]p22: 4866 // 4867 // For every triple (L, VQ, R), where L is an integral type, VQ 4868 // is either volatile or empty, and R is a promoted integral 4869 // type, there exist candidate operator functions of the form 4870 // 4871 // VQ L& operator%=(VQ L&, R); 4872 // VQ L& operator<<=(VQ L&, R); 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 for (unsigned Left = FirstIntegralType; Left < LastIntegralType; ++Left) { 4878 for (unsigned Right = FirstPromotedIntegralType; 4879 Right < LastPromotedIntegralType; ++Right) { 4880 QualType ParamTypes[2]; 4881 ParamTypes[1] = ArithmeticTypes[Right]; 4882 4883 // Add this built-in operator as a candidate (VQ is empty). 4884 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 4885 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 4886 if (VisibleTypeConversionsQuals.hasVolatile()) { 4887 // Add this built-in operator as a candidate (VQ is 'volatile'). 4888 ParamTypes[0] = ArithmeticTypes[Left]; 4889 ParamTypes[0] = Context.getVolatileType(ParamTypes[0]); 4890 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 4891 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 4892 } 4893 } 4894 } 4895 break; 4896 4897 case OO_Exclaim: { 4898 // C++ [over.operator]p23: 4899 // 4900 // There also exist candidate operator functions of the form 4901 // 4902 // bool operator!(bool); 4903 // bool operator&&(bool, bool); [BELOW] 4904 // bool operator||(bool, bool); [BELOW] 4905 QualType ParamTy = Context.BoolTy; 4906 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet, 4907 /*IsAssignmentOperator=*/false, 4908 /*NumContextualBoolArguments=*/1); 4909 break; 4910 } 4911 4912 case OO_AmpAmp: 4913 case OO_PipePipe: { 4914 // C++ [over.operator]p23: 4915 // 4916 // There also exist candidate operator functions of the form 4917 // 4918 // bool operator!(bool); [ABOVE] 4919 // bool operator&&(bool, bool); 4920 // bool operator||(bool, bool); 4921 QualType ParamTypes[2] = { Context.BoolTy, Context.BoolTy }; 4922 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet, 4923 /*IsAssignmentOperator=*/false, 4924 /*NumContextualBoolArguments=*/2); 4925 break; 4926 } 4927 4928 case OO_Subscript: 4929 // C++ [over.built]p13: 4930 // 4931 // For every cv-qualified or cv-unqualified object type T there 4932 // exist candidate operator functions of the form 4933 // 4934 // T* operator+(T*, ptrdiff_t); [ABOVE] 4935 // T& operator[](T*, ptrdiff_t); 4936 // T* operator-(T*, ptrdiff_t); [ABOVE] 4937 // T* operator+(ptrdiff_t, T*); [ABOVE] 4938 // T& operator[](ptrdiff_t, T*); 4939 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 4940 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4941 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 4942 QualType PointeeType = (*Ptr)->getAs<PointerType>()->getPointeeType(); 4943 QualType ResultTy = Context.getLValueReferenceType(PointeeType); 4944 4945 // T& operator[](T*, ptrdiff_t) 4946 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 4947 4948 // T& operator[](ptrdiff_t, T*); 4949 ParamTypes[0] = ParamTypes[1]; 4950 ParamTypes[1] = *Ptr; 4951 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 4952 } 4953 break; 4954 4955 case OO_ArrowStar: 4956 // C++ [over.built]p11: 4957 // For every quintuple (C1, C2, T, CV1, CV2), where C2 is a class type, 4958 // C1 is the same type as C2 or is a derived class of C2, T is an object 4959 // type or a function type, and CV1 and CV2 are cv-qualifier-seqs, 4960 // there exist candidate operator functions of the form 4961 // CV12 T& operator->*(CV1 C1*, CV2 T C2::*); 4962 // where CV12 is the union of CV1 and CV2. 4963 { 4964 for (BuiltinCandidateTypeSet::iterator Ptr = 4965 CandidateTypes.pointer_begin(); 4966 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4967 QualType C1Ty = (*Ptr); 4968 QualType C1; 4969 QualifierCollector Q1; 4970 if (const PointerType *PointerTy = C1Ty->getAs<PointerType>()) { 4971 C1 = QualType(Q1.strip(PointerTy->getPointeeType()), 0); 4972 if (!isa<RecordType>(C1)) 4973 continue; 4974 // heuristic to reduce number of builtin candidates in the set. 4975 // Add volatile/restrict version only if there are conversions to a 4976 // volatile/restrict type. 4977 if (!VisibleTypeConversionsQuals.hasVolatile() && Q1.hasVolatile()) 4978 continue; 4979 if (!VisibleTypeConversionsQuals.hasRestrict() && Q1.hasRestrict()) 4980 continue; 4981 } 4982 for (BuiltinCandidateTypeSet::iterator 4983 MemPtr = CandidateTypes.member_pointer_begin(), 4984 MemPtrEnd = CandidateTypes.member_pointer_end(); 4985 MemPtr != MemPtrEnd; ++MemPtr) { 4986 const MemberPointerType *mptr = cast<MemberPointerType>(*MemPtr); 4987 QualType C2 = QualType(mptr->getClass(), 0); 4988 C2 = C2.getUnqualifiedType(); 4989 if (C1 != C2 && !IsDerivedFrom(C1, C2)) 4990 break; 4991 QualType ParamTypes[2] = { *Ptr, *MemPtr }; 4992 // build CV12 T& 4993 QualType T = mptr->getPointeeType(); 4994 if (!VisibleTypeConversionsQuals.hasVolatile() && 4995 T.isVolatileQualified()) 4996 continue; 4997 if (!VisibleTypeConversionsQuals.hasRestrict() && 4998 T.isRestrictQualified()) 4999 continue; 5000 T = Q1.apply(T); 5001 QualType ResultTy = Context.getLValueReferenceType(T); 5002 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 5003 } 5004 } 5005 } 5006 break; 5007 5008 case OO_Conditional: 5009 // Note that we don't consider the first argument, since it has been 5010 // contextually converted to bool long ago. The candidates below are 5011 // therefore added as binary. 5012 // 5013 // C++ [over.built]p24: 5014 // For every type T, where T is a pointer or pointer-to-member type, 5015 // there exist candidate operator functions of the form 5016 // 5017 // T operator?(bool, T, T); 5018 // 5019 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(), 5020 E = CandidateTypes.pointer_end(); Ptr != E; ++Ptr) { 5021 QualType ParamTypes[2] = { *Ptr, *Ptr }; 5022 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 5023 } 5024 for (BuiltinCandidateTypeSet::iterator Ptr = 5025 CandidateTypes.member_pointer_begin(), 5026 E = CandidateTypes.member_pointer_end(); Ptr != E; ++Ptr) { 5027 QualType ParamTypes[2] = { *Ptr, *Ptr }; 5028 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 5029 } 5030 goto Conditional; 5031 } 5032} 5033 5034/// \brief Add function candidates found via argument-dependent lookup 5035/// to the set of overloading candidates. 5036/// 5037/// This routine performs argument-dependent name lookup based on the 5038/// given function name (which may also be an operator name) and adds 5039/// all of the overload candidates found by ADL to the overload 5040/// candidate set (C++ [basic.lookup.argdep]). 5041void 5042Sema::AddArgumentDependentLookupCandidates(DeclarationName Name, 5043 bool Operator, 5044 Expr **Args, unsigned NumArgs, 5045 const TemplateArgumentListInfo *ExplicitTemplateArgs, 5046 OverloadCandidateSet& CandidateSet, 5047 bool PartialOverloading) { 5048 ADLResult Fns; 5049 5050 // FIXME: This approach for uniquing ADL results (and removing 5051 // redundant candidates from the set) relies on pointer-equality, 5052 // which means we need to key off the canonical decl. However, 5053 // always going back to the canonical decl might not get us the 5054 // right set of default arguments. What default arguments are 5055 // we supposed to consider on ADL candidates, anyway? 5056 5057 // FIXME: Pass in the explicit template arguments? 5058 ArgumentDependentLookup(Name, Operator, Args, NumArgs, Fns); 5059 5060 // Erase all of the candidates we already knew about. 5061 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 5062 CandEnd = CandidateSet.end(); 5063 Cand != CandEnd; ++Cand) 5064 if (Cand->Function) { 5065 Fns.erase(Cand->Function); 5066 if (FunctionTemplateDecl *FunTmpl = Cand->Function->getPrimaryTemplate()) 5067 Fns.erase(FunTmpl); 5068 } 5069 5070 // For each of the ADL candidates we found, add it to the overload 5071 // set. 5072 for (ADLResult::iterator I = Fns.begin(), E = Fns.end(); I != E; ++I) { 5073 DeclAccessPair FoundDecl = DeclAccessPair::make(*I, AS_none); 5074 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*I)) { 5075 if (ExplicitTemplateArgs) 5076 continue; 5077 5078 AddOverloadCandidate(FD, FoundDecl, Args, NumArgs, CandidateSet, 5079 false, PartialOverloading); 5080 } else 5081 AddTemplateOverloadCandidate(cast<FunctionTemplateDecl>(*I), 5082 FoundDecl, ExplicitTemplateArgs, 5083 Args, NumArgs, CandidateSet); 5084 } 5085} 5086 5087/// isBetterOverloadCandidate - Determines whether the first overload 5088/// candidate is a better candidate than the second (C++ 13.3.3p1). 5089bool 5090Sema::isBetterOverloadCandidate(const OverloadCandidate& Cand1, 5091 const OverloadCandidate& Cand2, 5092 SourceLocation Loc) { 5093 // Define viable functions to be better candidates than non-viable 5094 // functions. 5095 if (!Cand2.Viable) 5096 return Cand1.Viable; 5097 else if (!Cand1.Viable) 5098 return false; 5099 5100 // C++ [over.match.best]p1: 5101 // 5102 // -- if F is a static member function, ICS1(F) is defined such 5103 // that ICS1(F) is neither better nor worse than ICS1(G) for 5104 // any function G, and, symmetrically, ICS1(G) is neither 5105 // better nor worse than ICS1(F). 5106 unsigned StartArg = 0; 5107 if (Cand1.IgnoreObjectArgument || Cand2.IgnoreObjectArgument) 5108 StartArg = 1; 5109 5110 // C++ [over.match.best]p1: 5111 // A viable function F1 is defined to be a better function than another 5112 // viable function F2 if for all arguments i, ICSi(F1) is not a worse 5113 // conversion sequence than ICSi(F2), and then... 5114 unsigned NumArgs = Cand1.Conversions.size(); 5115 assert(Cand2.Conversions.size() == NumArgs && "Overload candidate mismatch"); 5116 bool HasBetterConversion = false; 5117 for (unsigned ArgIdx = StartArg; ArgIdx < NumArgs; ++ArgIdx) { 5118 switch (CompareImplicitConversionSequences(Cand1.Conversions[ArgIdx], 5119 Cand2.Conversions[ArgIdx])) { 5120 case ImplicitConversionSequence::Better: 5121 // Cand1 has a better conversion sequence. 5122 HasBetterConversion = true; 5123 break; 5124 5125 case ImplicitConversionSequence::Worse: 5126 // Cand1 can't be better than Cand2. 5127 return false; 5128 5129 case ImplicitConversionSequence::Indistinguishable: 5130 // Do nothing. 5131 break; 5132 } 5133 } 5134 5135 // -- for some argument j, ICSj(F1) is a better conversion sequence than 5136 // ICSj(F2), or, if not that, 5137 if (HasBetterConversion) 5138 return true; 5139 5140 // - F1 is a non-template function and F2 is a function template 5141 // specialization, or, if not that, 5142 if ((!Cand1.Function || !Cand1.Function->getPrimaryTemplate()) && 5143 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 5144 return true; 5145 5146 // -- F1 and F2 are function template specializations, and the function 5147 // template for F1 is more specialized than the template for F2 5148 // according to the partial ordering rules described in 14.5.5.2, or, 5149 // if not that, 5150 if (Cand1.Function && Cand1.Function->getPrimaryTemplate() && 5151 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 5152 if (FunctionTemplateDecl *BetterTemplate 5153 = getMoreSpecializedTemplate(Cand1.Function->getPrimaryTemplate(), 5154 Cand2.Function->getPrimaryTemplate(), 5155 Loc, 5156 isa<CXXConversionDecl>(Cand1.Function)? TPOC_Conversion 5157 : TPOC_Call)) 5158 return BetterTemplate == Cand1.Function->getPrimaryTemplate(); 5159 5160 // -- the context is an initialization by user-defined conversion 5161 // (see 8.5, 13.3.1.5) and the standard conversion sequence 5162 // from the return type of F1 to the destination type (i.e., 5163 // the type of the entity being initialized) is a better 5164 // conversion sequence than the standard conversion sequence 5165 // from the return type of F2 to the destination type. 5166 if (Cand1.Function && Cand2.Function && 5167 isa<CXXConversionDecl>(Cand1.Function) && 5168 isa<CXXConversionDecl>(Cand2.Function)) { 5169 switch (CompareStandardConversionSequences(Cand1.FinalConversion, 5170 Cand2.FinalConversion)) { 5171 case ImplicitConversionSequence::Better: 5172 // Cand1 has a better conversion sequence. 5173 return true; 5174 5175 case ImplicitConversionSequence::Worse: 5176 // Cand1 can't be better than Cand2. 5177 return false; 5178 5179 case ImplicitConversionSequence::Indistinguishable: 5180 // Do nothing 5181 break; 5182 } 5183 } 5184 5185 return false; 5186} 5187 5188/// \brief Computes the best viable function (C++ 13.3.3) 5189/// within an overload candidate set. 5190/// 5191/// \param CandidateSet the set of candidate functions. 5192/// 5193/// \param Loc the location of the function name (or operator symbol) for 5194/// which overload resolution occurs. 5195/// 5196/// \param Best f overload resolution was successful or found a deleted 5197/// function, Best points to the candidate function found. 5198/// 5199/// \returns The result of overload resolution. 5200OverloadingResult Sema::BestViableFunction(OverloadCandidateSet& CandidateSet, 5201 SourceLocation Loc, 5202 OverloadCandidateSet::iterator& Best) { 5203 // Find the best viable function. 5204 Best = CandidateSet.end(); 5205 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 5206 Cand != CandidateSet.end(); ++Cand) { 5207 if (Cand->Viable) { 5208 if (Best == CandidateSet.end() || 5209 isBetterOverloadCandidate(*Cand, *Best, Loc)) 5210 Best = Cand; 5211 } 5212 } 5213 5214 // If we didn't find any viable functions, abort. 5215 if (Best == CandidateSet.end()) 5216 return OR_No_Viable_Function; 5217 5218 // Make sure that this function is better than every other viable 5219 // function. If not, we have an ambiguity. 5220 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 5221 Cand != CandidateSet.end(); ++Cand) { 5222 if (Cand->Viable && 5223 Cand != Best && 5224 !isBetterOverloadCandidate(*Best, *Cand, Loc)) { 5225 Best = CandidateSet.end(); 5226 return OR_Ambiguous; 5227 } 5228 } 5229 5230 // Best is the best viable function. 5231 if (Best->Function && 5232 (Best->Function->isDeleted() || 5233 Best->Function->getAttr<UnavailableAttr>())) 5234 return OR_Deleted; 5235 5236 // C++ [basic.def.odr]p2: 5237 // An overloaded function is used if it is selected by overload resolution 5238 // when referred to from a potentially-evaluated expression. [Note: this 5239 // covers calls to named functions (5.2.2), operator overloading 5240 // (clause 13), user-defined conversions (12.3.2), allocation function for 5241 // placement new (5.3.4), as well as non-default initialization (8.5). 5242 if (Best->Function) 5243 MarkDeclarationReferenced(Loc, Best->Function); 5244 return OR_Success; 5245} 5246 5247namespace { 5248 5249enum OverloadCandidateKind { 5250 oc_function, 5251 oc_method, 5252 oc_constructor, 5253 oc_function_template, 5254 oc_method_template, 5255 oc_constructor_template, 5256 oc_implicit_default_constructor, 5257 oc_implicit_copy_constructor, 5258 oc_implicit_copy_assignment 5259}; 5260 5261OverloadCandidateKind ClassifyOverloadCandidate(Sema &S, 5262 FunctionDecl *Fn, 5263 std::string &Description) { 5264 bool isTemplate = false; 5265 5266 if (FunctionTemplateDecl *FunTmpl = Fn->getPrimaryTemplate()) { 5267 isTemplate = true; 5268 Description = S.getTemplateArgumentBindingsText( 5269 FunTmpl->getTemplateParameters(), *Fn->getTemplateSpecializationArgs()); 5270 } 5271 5272 if (CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(Fn)) { 5273 if (!Ctor->isImplicit()) 5274 return isTemplate ? oc_constructor_template : oc_constructor; 5275 5276 return Ctor->isCopyConstructor() ? oc_implicit_copy_constructor 5277 : oc_implicit_default_constructor; 5278 } 5279 5280 if (CXXMethodDecl *Meth = dyn_cast<CXXMethodDecl>(Fn)) { 5281 // This actually gets spelled 'candidate function' for now, but 5282 // it doesn't hurt to split it out. 5283 if (!Meth->isImplicit()) 5284 return isTemplate ? oc_method_template : oc_method; 5285 5286 assert(Meth->isCopyAssignment() 5287 && "implicit method is not copy assignment operator?"); 5288 return oc_implicit_copy_assignment; 5289 } 5290 5291 return isTemplate ? oc_function_template : oc_function; 5292} 5293 5294} // end anonymous namespace 5295 5296// Notes the location of an overload candidate. 5297void Sema::NoteOverloadCandidate(FunctionDecl *Fn) { 5298 std::string FnDesc; 5299 OverloadCandidateKind K = ClassifyOverloadCandidate(*this, Fn, FnDesc); 5300 Diag(Fn->getLocation(), diag::note_ovl_candidate) 5301 << (unsigned) K << FnDesc; 5302} 5303 5304/// Diagnoses an ambiguous conversion. The partial diagnostic is the 5305/// "lead" diagnostic; it will be given two arguments, the source and 5306/// target types of the conversion. 5307void Sema::DiagnoseAmbiguousConversion(const ImplicitConversionSequence &ICS, 5308 SourceLocation CaretLoc, 5309 const PartialDiagnostic &PDiag) { 5310 Diag(CaretLoc, PDiag) 5311 << ICS.Ambiguous.getFromType() << ICS.Ambiguous.getToType(); 5312 for (AmbiguousConversionSequence::const_iterator 5313 I = ICS.Ambiguous.begin(), E = ICS.Ambiguous.end(); I != E; ++I) { 5314 NoteOverloadCandidate(*I); 5315 } 5316} 5317 5318namespace { 5319 5320void DiagnoseBadConversion(Sema &S, OverloadCandidate *Cand, unsigned I) { 5321 const ImplicitConversionSequence &Conv = Cand->Conversions[I]; 5322 assert(Conv.isBad()); 5323 assert(Cand->Function && "for now, candidate must be a function"); 5324 FunctionDecl *Fn = Cand->Function; 5325 5326 // There's a conversion slot for the object argument if this is a 5327 // non-constructor method. Note that 'I' corresponds the 5328 // conversion-slot index. 5329 bool isObjectArgument = false; 5330 if (isa<CXXMethodDecl>(Fn) && !isa<CXXConstructorDecl>(Fn)) { 5331 if (I == 0) 5332 isObjectArgument = true; 5333 else 5334 I--; 5335 } 5336 5337 std::string FnDesc; 5338 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, FnDesc); 5339 5340 Expr *FromExpr = Conv.Bad.FromExpr; 5341 QualType FromTy = Conv.Bad.getFromType(); 5342 QualType ToTy = Conv.Bad.getToType(); 5343 5344 if (FromTy == S.Context.OverloadTy) { 5345 assert(FromExpr && "overload set argument came from implicit argument?"); 5346 Expr *E = FromExpr->IgnoreParens(); 5347 if (isa<UnaryOperator>(E)) 5348 E = cast<UnaryOperator>(E)->getSubExpr()->IgnoreParens(); 5349 DeclarationName Name = cast<OverloadExpr>(E)->getName(); 5350 5351 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_overload) 5352 << (unsigned) FnKind << FnDesc 5353 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 5354 << ToTy << Name << I+1; 5355 return; 5356 } 5357 5358 // Do some hand-waving analysis to see if the non-viability is due 5359 // to a qualifier mismatch. 5360 CanQualType CFromTy = S.Context.getCanonicalType(FromTy); 5361 CanQualType CToTy = S.Context.getCanonicalType(ToTy); 5362 if (CanQual<ReferenceType> RT = CToTy->getAs<ReferenceType>()) 5363 CToTy = RT->getPointeeType(); 5364 else { 5365 // TODO: detect and diagnose the full richness of const mismatches. 5366 if (CanQual<PointerType> FromPT = CFromTy->getAs<PointerType>()) 5367 if (CanQual<PointerType> ToPT = CToTy->getAs<PointerType>()) 5368 CFromTy = FromPT->getPointeeType(), CToTy = ToPT->getPointeeType(); 5369 } 5370 5371 if (CToTy.getUnqualifiedType() == CFromTy.getUnqualifiedType() && 5372 !CToTy.isAtLeastAsQualifiedAs(CFromTy)) { 5373 // It is dumb that we have to do this here. 5374 while (isa<ArrayType>(CFromTy)) 5375 CFromTy = CFromTy->getAs<ArrayType>()->getElementType(); 5376 while (isa<ArrayType>(CToTy)) 5377 CToTy = CFromTy->getAs<ArrayType>()->getElementType(); 5378 5379 Qualifiers FromQs = CFromTy.getQualifiers(); 5380 Qualifiers ToQs = CToTy.getQualifiers(); 5381 5382 if (FromQs.getAddressSpace() != ToQs.getAddressSpace()) { 5383 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_addrspace) 5384 << (unsigned) FnKind << FnDesc 5385 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 5386 << FromTy 5387 << FromQs.getAddressSpace() << ToQs.getAddressSpace() 5388 << (unsigned) isObjectArgument << I+1; 5389 return; 5390 } 5391 5392 unsigned CVR = FromQs.getCVRQualifiers() & ~ToQs.getCVRQualifiers(); 5393 assert(CVR && "unexpected qualifiers mismatch"); 5394 5395 if (isObjectArgument) { 5396 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr_this) 5397 << (unsigned) FnKind << FnDesc 5398 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 5399 << FromTy << (CVR - 1); 5400 } else { 5401 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr) 5402 << (unsigned) FnKind << FnDesc 5403 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 5404 << FromTy << (CVR - 1) << I+1; 5405 } 5406 return; 5407 } 5408 5409 // Diagnose references or pointers to incomplete types differently, 5410 // since it's far from impossible that the incompleteness triggered 5411 // the failure. 5412 QualType TempFromTy = FromTy.getNonReferenceType(); 5413 if (const PointerType *PTy = TempFromTy->getAs<PointerType>()) 5414 TempFromTy = PTy->getPointeeType(); 5415 if (TempFromTy->isIncompleteType()) { 5416 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_conv_incomplete) 5417 << (unsigned) FnKind << FnDesc 5418 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 5419 << FromTy << ToTy << (unsigned) isObjectArgument << I+1; 5420 return; 5421 } 5422 5423 // TODO: specialize more based on the kind of mismatch 5424 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_conv) 5425 << (unsigned) FnKind << FnDesc 5426 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 5427 << FromTy << ToTy << (unsigned) isObjectArgument << I+1; 5428} 5429 5430void DiagnoseArityMismatch(Sema &S, OverloadCandidate *Cand, 5431 unsigned NumFormalArgs) { 5432 // TODO: treat calls to a missing default constructor as a special case 5433 5434 FunctionDecl *Fn = Cand->Function; 5435 const FunctionProtoType *FnTy = Fn->getType()->getAs<FunctionProtoType>(); 5436 5437 unsigned MinParams = Fn->getMinRequiredArguments(); 5438 5439 // at least / at most / exactly 5440 // FIXME: variadic templates "at most" should account for parameter packs 5441 unsigned mode, modeCount; 5442 if (NumFormalArgs < MinParams) { 5443 assert((Cand->FailureKind == ovl_fail_too_few_arguments) || 5444 (Cand->FailureKind == ovl_fail_bad_deduction && 5445 Cand->DeductionFailure.Result == Sema::TDK_TooFewArguments)); 5446 if (MinParams != FnTy->getNumArgs() || FnTy->isVariadic()) 5447 mode = 0; // "at least" 5448 else 5449 mode = 2; // "exactly" 5450 modeCount = MinParams; 5451 } else { 5452 assert((Cand->FailureKind == ovl_fail_too_many_arguments) || 5453 (Cand->FailureKind == ovl_fail_bad_deduction && 5454 Cand->DeductionFailure.Result == Sema::TDK_TooManyArguments)); 5455 if (MinParams != FnTy->getNumArgs()) 5456 mode = 1; // "at most" 5457 else 5458 mode = 2; // "exactly" 5459 modeCount = FnTy->getNumArgs(); 5460 } 5461 5462 std::string Description; 5463 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, Description); 5464 5465 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_arity) 5466 << (unsigned) FnKind << (Fn->getDescribedFunctionTemplate() != 0) << mode 5467 << modeCount << NumFormalArgs; 5468} 5469 5470/// Diagnose a failed template-argument deduction. 5471void DiagnoseBadDeduction(Sema &S, OverloadCandidate *Cand, 5472 Expr **Args, unsigned NumArgs) { 5473 FunctionDecl *Fn = Cand->Function; // pattern 5474 5475 TemplateParameter Param = Cand->DeductionFailure.getTemplateParameter(); 5476 NamedDecl *ParamD; 5477 (ParamD = Param.dyn_cast<TemplateTypeParmDecl*>()) || 5478 (ParamD = Param.dyn_cast<NonTypeTemplateParmDecl*>()) || 5479 (ParamD = Param.dyn_cast<TemplateTemplateParmDecl*>()); 5480 switch (Cand->DeductionFailure.Result) { 5481 case Sema::TDK_Success: 5482 llvm_unreachable("TDK_success while diagnosing bad deduction"); 5483 5484 case Sema::TDK_Incomplete: { 5485 assert(ParamD && "no parameter found for incomplete deduction result"); 5486 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_incomplete_deduction) 5487 << ParamD->getDeclName(); 5488 return; 5489 } 5490 5491 case Sema::TDK_Inconsistent: 5492 case Sema::TDK_InconsistentQuals: { 5493 assert(ParamD && "no parameter found for inconsistent deduction result"); 5494 int which = 0; 5495 if (isa<TemplateTypeParmDecl>(ParamD)) 5496 which = 0; 5497 else if (isa<NonTypeTemplateParmDecl>(ParamD)) 5498 which = 1; 5499 else { 5500 which = 2; 5501 } 5502 5503 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_inconsistent_deduction) 5504 << which << ParamD->getDeclName() 5505 << *Cand->DeductionFailure.getFirstArg() 5506 << *Cand->DeductionFailure.getSecondArg(); 5507 return; 5508 } 5509 5510 case Sema::TDK_InvalidExplicitArguments: 5511 assert(ParamD && "no parameter found for invalid explicit arguments"); 5512 if (ParamD->getDeclName()) 5513 S.Diag(Fn->getLocation(), 5514 diag::note_ovl_candidate_explicit_arg_mismatch_named) 5515 << ParamD->getDeclName(); 5516 else { 5517 int index = 0; 5518 if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(ParamD)) 5519 index = TTP->getIndex(); 5520 else if (NonTypeTemplateParmDecl *NTTP 5521 = dyn_cast<NonTypeTemplateParmDecl>(ParamD)) 5522 index = NTTP->getIndex(); 5523 else 5524 index = cast<TemplateTemplateParmDecl>(ParamD)->getIndex(); 5525 S.Diag(Fn->getLocation(), 5526 diag::note_ovl_candidate_explicit_arg_mismatch_unnamed) 5527 << (index + 1); 5528 } 5529 return; 5530 5531 case Sema::TDK_TooManyArguments: 5532 case Sema::TDK_TooFewArguments: 5533 DiagnoseArityMismatch(S, Cand, NumArgs); 5534 return; 5535 5536 case Sema::TDK_InstantiationDepth: 5537 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_instantiation_depth); 5538 return; 5539 5540 case Sema::TDK_SubstitutionFailure: { 5541 std::string ArgString; 5542 if (TemplateArgumentList *Args 5543 = Cand->DeductionFailure.getTemplateArgumentList()) 5544 ArgString = S.getTemplateArgumentBindingsText( 5545 Fn->getDescribedFunctionTemplate()->getTemplateParameters(), 5546 *Args); 5547 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_substitution_failure) 5548 << ArgString; 5549 return; 5550 } 5551 5552 // TODO: diagnose these individually, then kill off 5553 // note_ovl_candidate_bad_deduction, which is uselessly vague. 5554 case Sema::TDK_NonDeducedMismatch: 5555 case Sema::TDK_FailedOverloadResolution: 5556 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_deduction); 5557 return; 5558 } 5559} 5560 5561/// Generates a 'note' diagnostic for an overload candidate. We've 5562/// already generated a primary error at the call site. 5563/// 5564/// It really does need to be a single diagnostic with its caret 5565/// pointed at the candidate declaration. Yes, this creates some 5566/// major challenges of technical writing. Yes, this makes pointing 5567/// out problems with specific arguments quite awkward. It's still 5568/// better than generating twenty screens of text for every failed 5569/// overload. 5570/// 5571/// It would be great to be able to express per-candidate problems 5572/// more richly for those diagnostic clients that cared, but we'd 5573/// still have to be just as careful with the default diagnostics. 5574void NoteFunctionCandidate(Sema &S, OverloadCandidate *Cand, 5575 Expr **Args, unsigned NumArgs) { 5576 FunctionDecl *Fn = Cand->Function; 5577 5578 // Note deleted candidates, but only if they're viable. 5579 if (Cand->Viable && (Fn->isDeleted() || Fn->hasAttr<UnavailableAttr>())) { 5580 std::string FnDesc; 5581 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, FnDesc); 5582 5583 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_deleted) 5584 << FnKind << FnDesc << Fn->isDeleted(); 5585 return; 5586 } 5587 5588 // We don't really have anything else to say about viable candidates. 5589 if (Cand->Viable) { 5590 S.NoteOverloadCandidate(Fn); 5591 return; 5592 } 5593 5594 switch (Cand->FailureKind) { 5595 case ovl_fail_too_many_arguments: 5596 case ovl_fail_too_few_arguments: 5597 return DiagnoseArityMismatch(S, Cand, NumArgs); 5598 5599 case ovl_fail_bad_deduction: 5600 return DiagnoseBadDeduction(S, Cand, Args, NumArgs); 5601 5602 case ovl_fail_trivial_conversion: 5603 case ovl_fail_bad_final_conversion: 5604 case ovl_fail_final_conversion_not_exact: 5605 return S.NoteOverloadCandidate(Fn); 5606 5607 case ovl_fail_bad_conversion: { 5608 unsigned I = (Cand->IgnoreObjectArgument ? 1 : 0); 5609 for (unsigned N = Cand->Conversions.size(); I != N; ++I) 5610 if (Cand->Conversions[I].isBad()) 5611 return DiagnoseBadConversion(S, Cand, I); 5612 5613 // FIXME: this currently happens when we're called from SemaInit 5614 // when user-conversion overload fails. Figure out how to handle 5615 // those conditions and diagnose them well. 5616 return S.NoteOverloadCandidate(Fn); 5617 } 5618 } 5619} 5620 5621void NoteSurrogateCandidate(Sema &S, OverloadCandidate *Cand) { 5622 // Desugar the type of the surrogate down to a function type, 5623 // retaining as many typedefs as possible while still showing 5624 // the function type (and, therefore, its parameter types). 5625 QualType FnType = Cand->Surrogate->getConversionType(); 5626 bool isLValueReference = false; 5627 bool isRValueReference = false; 5628 bool isPointer = false; 5629 if (const LValueReferenceType *FnTypeRef = 5630 FnType->getAs<LValueReferenceType>()) { 5631 FnType = FnTypeRef->getPointeeType(); 5632 isLValueReference = true; 5633 } else if (const RValueReferenceType *FnTypeRef = 5634 FnType->getAs<RValueReferenceType>()) { 5635 FnType = FnTypeRef->getPointeeType(); 5636 isRValueReference = true; 5637 } 5638 if (const PointerType *FnTypePtr = FnType->getAs<PointerType>()) { 5639 FnType = FnTypePtr->getPointeeType(); 5640 isPointer = true; 5641 } 5642 // Desugar down to a function type. 5643 FnType = QualType(FnType->getAs<FunctionType>(), 0); 5644 // Reconstruct the pointer/reference as appropriate. 5645 if (isPointer) FnType = S.Context.getPointerType(FnType); 5646 if (isRValueReference) FnType = S.Context.getRValueReferenceType(FnType); 5647 if (isLValueReference) FnType = S.Context.getLValueReferenceType(FnType); 5648 5649 S.Diag(Cand->Surrogate->getLocation(), diag::note_ovl_surrogate_cand) 5650 << FnType; 5651} 5652 5653void NoteBuiltinOperatorCandidate(Sema &S, 5654 const char *Opc, 5655 SourceLocation OpLoc, 5656 OverloadCandidate *Cand) { 5657 assert(Cand->Conversions.size() <= 2 && "builtin operator is not binary"); 5658 std::string TypeStr("operator"); 5659 TypeStr += Opc; 5660 TypeStr += "("; 5661 TypeStr += Cand->BuiltinTypes.ParamTypes[0].getAsString(); 5662 if (Cand->Conversions.size() == 1) { 5663 TypeStr += ")"; 5664 S.Diag(OpLoc, diag::note_ovl_builtin_unary_candidate) << TypeStr; 5665 } else { 5666 TypeStr += ", "; 5667 TypeStr += Cand->BuiltinTypes.ParamTypes[1].getAsString(); 5668 TypeStr += ")"; 5669 S.Diag(OpLoc, diag::note_ovl_builtin_binary_candidate) << TypeStr; 5670 } 5671} 5672 5673void NoteAmbiguousUserConversions(Sema &S, SourceLocation OpLoc, 5674 OverloadCandidate *Cand) { 5675 unsigned NoOperands = Cand->Conversions.size(); 5676 for (unsigned ArgIdx = 0; ArgIdx < NoOperands; ++ArgIdx) { 5677 const ImplicitConversionSequence &ICS = Cand->Conversions[ArgIdx]; 5678 if (ICS.isBad()) break; // all meaningless after first invalid 5679 if (!ICS.isAmbiguous()) continue; 5680 5681 S.DiagnoseAmbiguousConversion(ICS, OpLoc, 5682 S.PDiag(diag::note_ambiguous_type_conversion)); 5683 } 5684} 5685 5686SourceLocation GetLocationForCandidate(const OverloadCandidate *Cand) { 5687 if (Cand->Function) 5688 return Cand->Function->getLocation(); 5689 if (Cand->IsSurrogate) 5690 return Cand->Surrogate->getLocation(); 5691 return SourceLocation(); 5692} 5693 5694struct CompareOverloadCandidatesForDisplay { 5695 Sema &S; 5696 CompareOverloadCandidatesForDisplay(Sema &S) : S(S) {} 5697 5698 bool operator()(const OverloadCandidate *L, 5699 const OverloadCandidate *R) { 5700 // Fast-path this check. 5701 if (L == R) return false; 5702 5703 // Order first by viability. 5704 if (L->Viable) { 5705 if (!R->Viable) return true; 5706 5707 // TODO: introduce a tri-valued comparison for overload 5708 // candidates. Would be more worthwhile if we had a sort 5709 // that could exploit it. 5710 if (S.isBetterOverloadCandidate(*L, *R, SourceLocation())) return true; 5711 if (S.isBetterOverloadCandidate(*R, *L, SourceLocation())) return false; 5712 } else if (R->Viable) 5713 return false; 5714 5715 assert(L->Viable == R->Viable); 5716 5717 // Criteria by which we can sort non-viable candidates: 5718 if (!L->Viable) { 5719 // 1. Arity mismatches come after other candidates. 5720 if (L->FailureKind == ovl_fail_too_many_arguments || 5721 L->FailureKind == ovl_fail_too_few_arguments) 5722 return false; 5723 if (R->FailureKind == ovl_fail_too_many_arguments || 5724 R->FailureKind == ovl_fail_too_few_arguments) 5725 return true; 5726 5727 // 2. Bad conversions come first and are ordered by the number 5728 // of bad conversions and quality of good conversions. 5729 if (L->FailureKind == ovl_fail_bad_conversion) { 5730 if (R->FailureKind != ovl_fail_bad_conversion) 5731 return true; 5732 5733 // If there's any ordering between the defined conversions... 5734 // FIXME: this might not be transitive. 5735 assert(L->Conversions.size() == R->Conversions.size()); 5736 5737 int leftBetter = 0; 5738 unsigned I = (L->IgnoreObjectArgument || R->IgnoreObjectArgument); 5739 for (unsigned E = L->Conversions.size(); I != E; ++I) { 5740 switch (S.CompareImplicitConversionSequences(L->Conversions[I], 5741 R->Conversions[I])) { 5742 case ImplicitConversionSequence::Better: 5743 leftBetter++; 5744 break; 5745 5746 case ImplicitConversionSequence::Worse: 5747 leftBetter--; 5748 break; 5749 5750 case ImplicitConversionSequence::Indistinguishable: 5751 break; 5752 } 5753 } 5754 if (leftBetter > 0) return true; 5755 if (leftBetter < 0) return false; 5756 5757 } else if (R->FailureKind == ovl_fail_bad_conversion) 5758 return false; 5759 5760 // TODO: others? 5761 } 5762 5763 // Sort everything else by location. 5764 SourceLocation LLoc = GetLocationForCandidate(L); 5765 SourceLocation RLoc = GetLocationForCandidate(R); 5766 5767 // Put candidates without locations (e.g. builtins) at the end. 5768 if (LLoc.isInvalid()) return false; 5769 if (RLoc.isInvalid()) return true; 5770 5771 return S.SourceMgr.isBeforeInTranslationUnit(LLoc, RLoc); 5772 } 5773}; 5774 5775/// CompleteNonViableCandidate - Normally, overload resolution only 5776/// computes up to the first 5777void CompleteNonViableCandidate(Sema &S, OverloadCandidate *Cand, 5778 Expr **Args, unsigned NumArgs) { 5779 assert(!Cand->Viable); 5780 5781 // Don't do anything on failures other than bad conversion. 5782 if (Cand->FailureKind != ovl_fail_bad_conversion) return; 5783 5784 // Skip forward to the first bad conversion. 5785 unsigned ConvIdx = (Cand->IgnoreObjectArgument ? 1 : 0); 5786 unsigned ConvCount = Cand->Conversions.size(); 5787 while (true) { 5788 assert(ConvIdx != ConvCount && "no bad conversion in candidate"); 5789 ConvIdx++; 5790 if (Cand->Conversions[ConvIdx - 1].isBad()) 5791 break; 5792 } 5793 5794 if (ConvIdx == ConvCount) 5795 return; 5796 5797 assert(!Cand->Conversions[ConvIdx].isInitialized() && 5798 "remaining conversion is initialized?"); 5799 5800 // FIXME: this should probably be preserved from the overload 5801 // operation somehow. 5802 bool SuppressUserConversions = false; 5803 5804 const FunctionProtoType* Proto; 5805 unsigned ArgIdx = ConvIdx; 5806 5807 if (Cand->IsSurrogate) { 5808 QualType ConvType 5809 = Cand->Surrogate->getConversionType().getNonReferenceType(); 5810 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 5811 ConvType = ConvPtrType->getPointeeType(); 5812 Proto = ConvType->getAs<FunctionProtoType>(); 5813 ArgIdx--; 5814 } else if (Cand->Function) { 5815 Proto = Cand->Function->getType()->getAs<FunctionProtoType>(); 5816 if (isa<CXXMethodDecl>(Cand->Function) && 5817 !isa<CXXConstructorDecl>(Cand->Function)) 5818 ArgIdx--; 5819 } else { 5820 // Builtin binary operator with a bad first conversion. 5821 assert(ConvCount <= 3); 5822 for (; ConvIdx != ConvCount; ++ConvIdx) 5823 Cand->Conversions[ConvIdx] 5824 = TryCopyInitialization(S, Args[ConvIdx], 5825 Cand->BuiltinTypes.ParamTypes[ConvIdx], 5826 SuppressUserConversions, 5827 /*InOverloadResolution*/ true); 5828 return; 5829 } 5830 5831 // Fill in the rest of the conversions. 5832 unsigned NumArgsInProto = Proto->getNumArgs(); 5833 for (; ConvIdx != ConvCount; ++ConvIdx, ++ArgIdx) { 5834 if (ArgIdx < NumArgsInProto) 5835 Cand->Conversions[ConvIdx] 5836 = TryCopyInitialization(S, Args[ArgIdx], Proto->getArgType(ArgIdx), 5837 SuppressUserConversions, 5838 /*InOverloadResolution=*/true); 5839 else 5840 Cand->Conversions[ConvIdx].setEllipsis(); 5841 } 5842} 5843 5844} // end anonymous namespace 5845 5846/// PrintOverloadCandidates - When overload resolution fails, prints 5847/// diagnostic messages containing the candidates in the candidate 5848/// set. 5849void 5850Sema::PrintOverloadCandidates(OverloadCandidateSet& CandidateSet, 5851 OverloadCandidateDisplayKind OCD, 5852 Expr **Args, unsigned NumArgs, 5853 const char *Opc, 5854 SourceLocation OpLoc) { 5855 // Sort the candidates by viability and position. Sorting directly would 5856 // be prohibitive, so we make a set of pointers and sort those. 5857 llvm::SmallVector<OverloadCandidate*, 32> Cands; 5858 if (OCD == OCD_AllCandidates) Cands.reserve(CandidateSet.size()); 5859 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 5860 LastCand = CandidateSet.end(); 5861 Cand != LastCand; ++Cand) { 5862 if (Cand->Viable) 5863 Cands.push_back(Cand); 5864 else if (OCD == OCD_AllCandidates) { 5865 CompleteNonViableCandidate(*this, Cand, Args, NumArgs); 5866 if (Cand->Function || Cand->IsSurrogate) 5867 Cands.push_back(Cand); 5868 // Otherwise, this a non-viable builtin candidate. We do not, in general, 5869 // want to list every possible builtin candidate. 5870 } 5871 } 5872 5873 std::sort(Cands.begin(), Cands.end(), 5874 CompareOverloadCandidatesForDisplay(*this)); 5875 5876 bool ReportedAmbiguousConversions = false; 5877 5878 llvm::SmallVectorImpl<OverloadCandidate*>::iterator I, E; 5879 const Diagnostic::OverloadsShown ShowOverloads = Diags.getShowOverloads(); 5880 unsigned CandsShown = 0; 5881 for (I = Cands.begin(), E = Cands.end(); I != E; ++I) { 5882 OverloadCandidate *Cand = *I; 5883 5884 // Set an arbitrary limit on the number of candidate functions we'll spam 5885 // the user with. FIXME: This limit should depend on details of the 5886 // candidate list. 5887 if (CandsShown >= 4 && ShowOverloads == Diagnostic::Ovl_Best) { 5888 break; 5889 } 5890 ++CandsShown; 5891 5892 if (Cand->Function) 5893 NoteFunctionCandidate(*this, Cand, Args, NumArgs); 5894 else if (Cand->IsSurrogate) 5895 NoteSurrogateCandidate(*this, Cand); 5896 else { 5897 assert(Cand->Viable && 5898 "Non-viable built-in candidates are not added to Cands."); 5899 // Generally we only see ambiguities including viable builtin 5900 // operators if overload resolution got screwed up by an 5901 // ambiguous user-defined conversion. 5902 // 5903 // FIXME: It's quite possible for different conversions to see 5904 // different ambiguities, though. 5905 if (!ReportedAmbiguousConversions) { 5906 NoteAmbiguousUserConversions(*this, OpLoc, Cand); 5907 ReportedAmbiguousConversions = true; 5908 } 5909 5910 // If this is a viable builtin, print it. 5911 NoteBuiltinOperatorCandidate(*this, Opc, OpLoc, Cand); 5912 } 5913 } 5914 5915 if (I != E) 5916 Diag(OpLoc, diag::note_ovl_too_many_candidates) << int(E - I); 5917} 5918 5919static bool CheckUnresolvedAccess(Sema &S, OverloadExpr *E, DeclAccessPair D) { 5920 if (isa<UnresolvedLookupExpr>(E)) 5921 return S.CheckUnresolvedLookupAccess(cast<UnresolvedLookupExpr>(E), D); 5922 5923 return S.CheckUnresolvedMemberAccess(cast<UnresolvedMemberExpr>(E), D); 5924} 5925 5926/// ResolveAddressOfOverloadedFunction - Try to resolve the address of 5927/// an overloaded function (C++ [over.over]), where @p From is an 5928/// expression with overloaded function type and @p ToType is the type 5929/// we're trying to resolve to. For example: 5930/// 5931/// @code 5932/// int f(double); 5933/// int f(int); 5934/// 5935/// int (*pfd)(double) = f; // selects f(double) 5936/// @endcode 5937/// 5938/// This routine returns the resulting FunctionDecl if it could be 5939/// resolved, and NULL otherwise. When @p Complain is true, this 5940/// routine will emit diagnostics if there is an error. 5941FunctionDecl * 5942Sema::ResolveAddressOfOverloadedFunction(Expr *From, QualType ToType, 5943 bool Complain, 5944 DeclAccessPair &FoundResult) { 5945 QualType FunctionType = ToType; 5946 bool IsMember = false; 5947 if (const PointerType *ToTypePtr = ToType->getAs<PointerType>()) 5948 FunctionType = ToTypePtr->getPointeeType(); 5949 else if (const ReferenceType *ToTypeRef = ToType->getAs<ReferenceType>()) 5950 FunctionType = ToTypeRef->getPointeeType(); 5951 else if (const MemberPointerType *MemTypePtr = 5952 ToType->getAs<MemberPointerType>()) { 5953 FunctionType = MemTypePtr->getPointeeType(); 5954 IsMember = true; 5955 } 5956 5957 // C++ [over.over]p1: 5958 // [...] [Note: any redundant set of parentheses surrounding the 5959 // overloaded function name is ignored (5.1). ] 5960 // C++ [over.over]p1: 5961 // [...] The overloaded function name can be preceded by the & 5962 // operator. 5963 OverloadExpr *OvlExpr = OverloadExpr::find(From).getPointer(); 5964 TemplateArgumentListInfo ETABuffer, *ExplicitTemplateArgs = 0; 5965 if (OvlExpr->hasExplicitTemplateArgs()) { 5966 OvlExpr->getExplicitTemplateArgs().copyInto(ETABuffer); 5967 ExplicitTemplateArgs = &ETABuffer; 5968 } 5969 5970 // We expect a pointer or reference to function, or a function pointer. 5971 FunctionType = Context.getCanonicalType(FunctionType).getUnqualifiedType(); 5972 if (!FunctionType->isFunctionType()) { 5973 if (Complain) 5974 Diag(From->getLocStart(), diag::err_addr_ovl_not_func_ptrref) 5975 << OvlExpr->getName() << ToType; 5976 5977 return 0; 5978 } 5979 5980 assert(From->getType() == Context.OverloadTy); 5981 5982 // Look through all of the overloaded functions, searching for one 5983 // whose type matches exactly. 5984 llvm::SmallVector<std::pair<DeclAccessPair, FunctionDecl*>, 4> Matches; 5985 llvm::SmallVector<FunctionDecl *, 4> NonMatches; 5986 5987 bool FoundNonTemplateFunction = false; 5988 for (UnresolvedSetIterator I = OvlExpr->decls_begin(), 5989 E = OvlExpr->decls_end(); I != E; ++I) { 5990 // Look through any using declarations to find the underlying function. 5991 NamedDecl *Fn = (*I)->getUnderlyingDecl(); 5992 5993 // C++ [over.over]p3: 5994 // Non-member functions and static member functions match 5995 // targets of type "pointer-to-function" or "reference-to-function." 5996 // Nonstatic member functions match targets of 5997 // type "pointer-to-member-function." 5998 // Note that according to DR 247, the containing class does not matter. 5999 6000 if (FunctionTemplateDecl *FunctionTemplate 6001 = dyn_cast<FunctionTemplateDecl>(Fn)) { 6002 if (CXXMethodDecl *Method 6003 = dyn_cast<CXXMethodDecl>(FunctionTemplate->getTemplatedDecl())) { 6004 // Skip non-static function templates when converting to pointer, and 6005 // static when converting to member pointer. 6006 if (Method->isStatic() == IsMember) 6007 continue; 6008 } else if (IsMember) 6009 continue; 6010 6011 // C++ [over.over]p2: 6012 // If the name is a function template, template argument deduction is 6013 // done (14.8.2.2), and if the argument deduction succeeds, the 6014 // resulting template argument list is used to generate a single 6015 // function template specialization, which is added to the set of 6016 // overloaded functions considered. 6017 // FIXME: We don't really want to build the specialization here, do we? 6018 FunctionDecl *Specialization = 0; 6019 TemplateDeductionInfo Info(Context, OvlExpr->getNameLoc()); 6020 if (TemplateDeductionResult Result 6021 = DeduceTemplateArguments(FunctionTemplate, ExplicitTemplateArgs, 6022 FunctionType, Specialization, Info)) { 6023 // FIXME: make a note of the failed deduction for diagnostics. 6024 (void)Result; 6025 } else { 6026 // FIXME: If the match isn't exact, shouldn't we just drop this as 6027 // a candidate? Find a testcase before changing the code. 6028 assert(FunctionType 6029 == Context.getCanonicalType(Specialization->getType())); 6030 Matches.push_back(std::make_pair(I.getPair(), 6031 cast<FunctionDecl>(Specialization->getCanonicalDecl()))); 6032 } 6033 6034 continue; 6035 } 6036 6037 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 6038 // Skip non-static functions when converting to pointer, and static 6039 // when converting to member pointer. 6040 if (Method->isStatic() == IsMember) 6041 continue; 6042 6043 // If we have explicit template arguments, skip non-templates. 6044 if (OvlExpr->hasExplicitTemplateArgs()) 6045 continue; 6046 } else if (IsMember) 6047 continue; 6048 6049 if (FunctionDecl *FunDecl = dyn_cast<FunctionDecl>(Fn)) { 6050 QualType ResultTy; 6051 if (Context.hasSameUnqualifiedType(FunctionType, FunDecl->getType()) || 6052 IsNoReturnConversion(Context, FunDecl->getType(), FunctionType, 6053 ResultTy)) { 6054 Matches.push_back(std::make_pair(I.getPair(), 6055 cast<FunctionDecl>(FunDecl->getCanonicalDecl()))); 6056 FoundNonTemplateFunction = true; 6057 } 6058 } 6059 } 6060 6061 // If there were 0 or 1 matches, we're done. 6062 if (Matches.empty()) { 6063 if (Complain) { 6064 Diag(From->getLocStart(), diag::err_addr_ovl_no_viable) 6065 << OvlExpr->getName() << FunctionType; 6066 for (UnresolvedSetIterator I = OvlExpr->decls_begin(), 6067 E = OvlExpr->decls_end(); 6068 I != E; ++I) 6069 if (FunctionDecl *F = dyn_cast<FunctionDecl>((*I)->getUnderlyingDecl())) 6070 NoteOverloadCandidate(F); 6071 } 6072 6073 return 0; 6074 } else if (Matches.size() == 1) { 6075 FunctionDecl *Result = Matches[0].second; 6076 FoundResult = Matches[0].first; 6077 MarkDeclarationReferenced(From->getLocStart(), Result); 6078 if (Complain) 6079 CheckAddressOfMemberAccess(OvlExpr, Matches[0].first); 6080 return Result; 6081 } 6082 6083 // C++ [over.over]p4: 6084 // If more than one function is selected, [...] 6085 if (!FoundNonTemplateFunction) { 6086 // [...] and any given function template specialization F1 is 6087 // eliminated if the set contains a second function template 6088 // specialization whose function template is more specialized 6089 // than the function template of F1 according to the partial 6090 // ordering rules of 14.5.5.2. 6091 6092 // The algorithm specified above is quadratic. We instead use a 6093 // two-pass algorithm (similar to the one used to identify the 6094 // best viable function in an overload set) that identifies the 6095 // best function template (if it exists). 6096 6097 UnresolvedSet<4> MatchesCopy; // TODO: avoid! 6098 for (unsigned I = 0, E = Matches.size(); I != E; ++I) 6099 MatchesCopy.addDecl(Matches[I].second, Matches[I].first.getAccess()); 6100 6101 UnresolvedSetIterator Result = 6102 getMostSpecialized(MatchesCopy.begin(), MatchesCopy.end(), 6103 TPOC_Other, From->getLocStart(), 6104 PDiag(), 6105 PDiag(diag::err_addr_ovl_ambiguous) 6106 << Matches[0].second->getDeclName(), 6107 PDiag(diag::note_ovl_candidate) 6108 << (unsigned) oc_function_template); 6109 assert(Result != MatchesCopy.end() && "no most-specialized template"); 6110 MarkDeclarationReferenced(From->getLocStart(), *Result); 6111 FoundResult = Matches[Result - MatchesCopy.begin()].first; 6112 if (Complain) { 6113 CheckUnresolvedAccess(*this, OvlExpr, FoundResult); 6114 DiagnoseUseOfDecl(FoundResult, OvlExpr->getNameLoc()); 6115 } 6116 return cast<FunctionDecl>(*Result); 6117 } 6118 6119 // [...] any function template specializations in the set are 6120 // eliminated if the set also contains a non-template function, [...] 6121 for (unsigned I = 0, N = Matches.size(); I != N; ) { 6122 if (Matches[I].second->getPrimaryTemplate() == 0) 6123 ++I; 6124 else { 6125 Matches[I] = Matches[--N]; 6126 Matches.set_size(N); 6127 } 6128 } 6129 6130 // [...] After such eliminations, if any, there shall remain exactly one 6131 // selected function. 6132 if (Matches.size() == 1) { 6133 MarkDeclarationReferenced(From->getLocStart(), Matches[0].second); 6134 FoundResult = Matches[0].first; 6135 if (Complain) { 6136 CheckUnresolvedAccess(*this, OvlExpr, Matches[0].first); 6137 DiagnoseUseOfDecl(Matches[0].first, OvlExpr->getNameLoc()); 6138 } 6139 return cast<FunctionDecl>(Matches[0].second); 6140 } 6141 6142 // FIXME: We should probably return the same thing that BestViableFunction 6143 // returns (even if we issue the diagnostics here). 6144 Diag(From->getLocStart(), diag::err_addr_ovl_ambiguous) 6145 << Matches[0].second->getDeclName(); 6146 for (unsigned I = 0, E = Matches.size(); I != E; ++I) 6147 NoteOverloadCandidate(Matches[I].second); 6148 return 0; 6149} 6150 6151/// \brief Given an expression that refers to an overloaded function, try to 6152/// resolve that overloaded function expression down to a single function. 6153/// 6154/// This routine can only resolve template-ids that refer to a single function 6155/// template, where that template-id refers to a single template whose template 6156/// arguments are either provided by the template-id or have defaults, 6157/// as described in C++0x [temp.arg.explicit]p3. 6158FunctionDecl *Sema::ResolveSingleFunctionTemplateSpecialization(Expr *From) { 6159 // C++ [over.over]p1: 6160 // [...] [Note: any redundant set of parentheses surrounding the 6161 // overloaded function name is ignored (5.1). ] 6162 // C++ [over.over]p1: 6163 // [...] The overloaded function name can be preceded by the & 6164 // operator. 6165 6166 if (From->getType() != Context.OverloadTy) 6167 return 0; 6168 6169 OverloadExpr *OvlExpr = OverloadExpr::find(From).getPointer(); 6170 6171 // If we didn't actually find any template-ids, we're done. 6172 if (!OvlExpr->hasExplicitTemplateArgs()) 6173 return 0; 6174 6175 TemplateArgumentListInfo ExplicitTemplateArgs; 6176 OvlExpr->getExplicitTemplateArgs().copyInto(ExplicitTemplateArgs); 6177 6178 // Look through all of the overloaded functions, searching for one 6179 // whose type matches exactly. 6180 FunctionDecl *Matched = 0; 6181 for (UnresolvedSetIterator I = OvlExpr->decls_begin(), 6182 E = OvlExpr->decls_end(); I != E; ++I) { 6183 // C++0x [temp.arg.explicit]p3: 6184 // [...] In contexts where deduction is done and fails, or in contexts 6185 // where deduction is not done, if a template argument list is 6186 // specified and it, along with any default template arguments, 6187 // identifies a single function template specialization, then the 6188 // template-id is an lvalue for the function template specialization. 6189 FunctionTemplateDecl *FunctionTemplate = cast<FunctionTemplateDecl>(*I); 6190 6191 // C++ [over.over]p2: 6192 // If the name is a function template, template argument deduction is 6193 // done (14.8.2.2), and if the argument deduction succeeds, the 6194 // resulting template argument list is used to generate a single 6195 // function template specialization, which is added to the set of 6196 // overloaded functions considered. 6197 FunctionDecl *Specialization = 0; 6198 TemplateDeductionInfo Info(Context, OvlExpr->getNameLoc()); 6199 if (TemplateDeductionResult Result 6200 = DeduceTemplateArguments(FunctionTemplate, &ExplicitTemplateArgs, 6201 Specialization, Info)) { 6202 // FIXME: make a note of the failed deduction for diagnostics. 6203 (void)Result; 6204 continue; 6205 } 6206 6207 // Multiple matches; we can't resolve to a single declaration. 6208 if (Matched) 6209 return 0; 6210 6211 Matched = Specialization; 6212 } 6213 6214 return Matched; 6215} 6216 6217/// \brief Add a single candidate to the overload set. 6218static void AddOverloadedCallCandidate(Sema &S, 6219 DeclAccessPair FoundDecl, 6220 const TemplateArgumentListInfo *ExplicitTemplateArgs, 6221 Expr **Args, unsigned NumArgs, 6222 OverloadCandidateSet &CandidateSet, 6223 bool PartialOverloading) { 6224 NamedDecl *Callee = FoundDecl.getDecl(); 6225 if (isa<UsingShadowDecl>(Callee)) 6226 Callee = cast<UsingShadowDecl>(Callee)->getTargetDecl(); 6227 6228 if (FunctionDecl *Func = dyn_cast<FunctionDecl>(Callee)) { 6229 assert(!ExplicitTemplateArgs && "Explicit template arguments?"); 6230 S.AddOverloadCandidate(Func, FoundDecl, Args, NumArgs, CandidateSet, 6231 false, PartialOverloading); 6232 return; 6233 } 6234 6235 if (FunctionTemplateDecl *FuncTemplate 6236 = dyn_cast<FunctionTemplateDecl>(Callee)) { 6237 S.AddTemplateOverloadCandidate(FuncTemplate, FoundDecl, 6238 ExplicitTemplateArgs, 6239 Args, NumArgs, CandidateSet); 6240 return; 6241 } 6242 6243 assert(false && "unhandled case in overloaded call candidate"); 6244 6245 // do nothing? 6246} 6247 6248/// \brief Add the overload candidates named by callee and/or found by argument 6249/// dependent lookup to the given overload set. 6250void Sema::AddOverloadedCallCandidates(UnresolvedLookupExpr *ULE, 6251 Expr **Args, unsigned NumArgs, 6252 OverloadCandidateSet &CandidateSet, 6253 bool PartialOverloading) { 6254 6255#ifndef NDEBUG 6256 // Verify that ArgumentDependentLookup is consistent with the rules 6257 // in C++0x [basic.lookup.argdep]p3: 6258 // 6259 // Let X be the lookup set produced by unqualified lookup (3.4.1) 6260 // and let Y be the lookup set produced by argument dependent 6261 // lookup (defined as follows). If X contains 6262 // 6263 // -- a declaration of a class member, or 6264 // 6265 // -- a block-scope function declaration that is not a 6266 // using-declaration, or 6267 // 6268 // -- a declaration that is neither a function or a function 6269 // template 6270 // 6271 // then Y is empty. 6272 6273 if (ULE->requiresADL()) { 6274 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(), 6275 E = ULE->decls_end(); I != E; ++I) { 6276 assert(!(*I)->getDeclContext()->isRecord()); 6277 assert(isa<UsingShadowDecl>(*I) || 6278 !(*I)->getDeclContext()->isFunctionOrMethod()); 6279 assert((*I)->getUnderlyingDecl()->isFunctionOrFunctionTemplate()); 6280 } 6281 } 6282#endif 6283 6284 // It would be nice to avoid this copy. 6285 TemplateArgumentListInfo TABuffer; 6286 const TemplateArgumentListInfo *ExplicitTemplateArgs = 0; 6287 if (ULE->hasExplicitTemplateArgs()) { 6288 ULE->copyTemplateArgumentsInto(TABuffer); 6289 ExplicitTemplateArgs = &TABuffer; 6290 } 6291 6292 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(), 6293 E = ULE->decls_end(); I != E; ++I) 6294 AddOverloadedCallCandidate(*this, I.getPair(), ExplicitTemplateArgs, 6295 Args, NumArgs, CandidateSet, 6296 PartialOverloading); 6297 6298 if (ULE->requiresADL()) 6299 AddArgumentDependentLookupCandidates(ULE->getName(), /*Operator*/ false, 6300 Args, NumArgs, 6301 ExplicitTemplateArgs, 6302 CandidateSet, 6303 PartialOverloading); 6304} 6305 6306static Sema::OwningExprResult Destroy(Sema &SemaRef, Expr *Fn, 6307 Expr **Args, unsigned NumArgs) { 6308 Fn->Destroy(SemaRef.Context); 6309 for (unsigned Arg = 0; Arg < NumArgs; ++Arg) 6310 Args[Arg]->Destroy(SemaRef.Context); 6311 return SemaRef.ExprError(); 6312} 6313 6314/// Attempts to recover from a call where no functions were found. 6315/// 6316/// Returns true if new candidates were found. 6317static Sema::OwningExprResult 6318BuildRecoveryCallExpr(Sema &SemaRef, Scope *S, Expr *Fn, 6319 UnresolvedLookupExpr *ULE, 6320 SourceLocation LParenLoc, 6321 Expr **Args, unsigned NumArgs, 6322 SourceLocation *CommaLocs, 6323 SourceLocation RParenLoc) { 6324 6325 CXXScopeSpec SS; 6326 if (ULE->getQualifier()) { 6327 SS.setScopeRep(ULE->getQualifier()); 6328 SS.setRange(ULE->getQualifierRange()); 6329 } 6330 6331 TemplateArgumentListInfo TABuffer; 6332 const TemplateArgumentListInfo *ExplicitTemplateArgs = 0; 6333 if (ULE->hasExplicitTemplateArgs()) { 6334 ULE->copyTemplateArgumentsInto(TABuffer); 6335 ExplicitTemplateArgs = &TABuffer; 6336 } 6337 6338 LookupResult R(SemaRef, ULE->getName(), ULE->getNameLoc(), 6339 Sema::LookupOrdinaryName); 6340 if (SemaRef.DiagnoseEmptyLookup(S, SS, R, Sema::CTC_Expression)) 6341 return Destroy(SemaRef, Fn, Args, NumArgs); 6342 6343 assert(!R.empty() && "lookup results empty despite recovery"); 6344 6345 // Build an implicit member call if appropriate. Just drop the 6346 // casts and such from the call, we don't really care. 6347 Sema::OwningExprResult NewFn = SemaRef.ExprError(); 6348 if ((*R.begin())->isCXXClassMember()) 6349 NewFn = SemaRef.BuildPossibleImplicitMemberExpr(SS, R, ExplicitTemplateArgs); 6350 else if (ExplicitTemplateArgs) 6351 NewFn = SemaRef.BuildTemplateIdExpr(SS, R, false, *ExplicitTemplateArgs); 6352 else 6353 NewFn = SemaRef.BuildDeclarationNameExpr(SS, R, false); 6354 6355 if (NewFn.isInvalid()) 6356 return Destroy(SemaRef, Fn, Args, NumArgs); 6357 6358 Fn->Destroy(SemaRef.Context); 6359 6360 // This shouldn't cause an infinite loop because we're giving it 6361 // an expression with non-empty lookup results, which should never 6362 // end up here. 6363 return SemaRef.ActOnCallExpr(/*Scope*/ 0, move(NewFn), LParenLoc, 6364 Sema::MultiExprArg(SemaRef, (void**) Args, NumArgs), 6365 CommaLocs, RParenLoc); 6366} 6367 6368/// ResolveOverloadedCallFn - Given the call expression that calls Fn 6369/// (which eventually refers to the declaration Func) and the call 6370/// arguments Args/NumArgs, attempt to resolve the function call down 6371/// to a specific function. If overload resolution succeeds, returns 6372/// the function declaration produced by overload 6373/// resolution. Otherwise, emits diagnostics, deletes all of the 6374/// arguments and Fn, and returns NULL. 6375Sema::OwningExprResult 6376Sema::BuildOverloadedCallExpr(Scope *S, Expr *Fn, UnresolvedLookupExpr *ULE, 6377 SourceLocation LParenLoc, 6378 Expr **Args, unsigned NumArgs, 6379 SourceLocation *CommaLocs, 6380 SourceLocation RParenLoc) { 6381#ifndef NDEBUG 6382 if (ULE->requiresADL()) { 6383 // To do ADL, we must have found an unqualified name. 6384 assert(!ULE->getQualifier() && "qualified name with ADL"); 6385 6386 // We don't perform ADL for implicit declarations of builtins. 6387 // Verify that this was correctly set up. 6388 FunctionDecl *F; 6389 if (ULE->decls_begin() + 1 == ULE->decls_end() && 6390 (F = dyn_cast<FunctionDecl>(*ULE->decls_begin())) && 6391 F->getBuiltinID() && F->isImplicit()) 6392 assert(0 && "performing ADL for builtin"); 6393 6394 // We don't perform ADL in C. 6395 assert(getLangOptions().CPlusPlus && "ADL enabled in C"); 6396 } 6397#endif 6398 6399 OverloadCandidateSet CandidateSet(Fn->getExprLoc()); 6400 6401 // Add the functions denoted by the callee to the set of candidate 6402 // functions, including those from argument-dependent lookup. 6403 AddOverloadedCallCandidates(ULE, Args, NumArgs, CandidateSet); 6404 6405 // If we found nothing, try to recover. 6406 // AddRecoveryCallCandidates diagnoses the error itself, so we just 6407 // bailout out if it fails. 6408 if (CandidateSet.empty()) 6409 return BuildRecoveryCallExpr(*this, S, Fn, ULE, LParenLoc, Args, NumArgs, 6410 CommaLocs, RParenLoc); 6411 6412 OverloadCandidateSet::iterator Best; 6413 switch (BestViableFunction(CandidateSet, Fn->getLocStart(), Best)) { 6414 case OR_Success: { 6415 FunctionDecl *FDecl = Best->Function; 6416 CheckUnresolvedLookupAccess(ULE, Best->FoundDecl); 6417 DiagnoseUseOfDecl(Best->FoundDecl, ULE->getNameLoc()); 6418 Fn = FixOverloadedFunctionReference(Fn, Best->FoundDecl, FDecl); 6419 return BuildResolvedCallExpr(Fn, FDecl, LParenLoc, Args, NumArgs, RParenLoc); 6420 } 6421 6422 case OR_No_Viable_Function: 6423 Diag(Fn->getSourceRange().getBegin(), 6424 diag::err_ovl_no_viable_function_in_call) 6425 << ULE->getName() << Fn->getSourceRange(); 6426 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6427 break; 6428 6429 case OR_Ambiguous: 6430 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_ambiguous_call) 6431 << ULE->getName() << Fn->getSourceRange(); 6432 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, NumArgs); 6433 break; 6434 6435 case OR_Deleted: 6436 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_deleted_call) 6437 << Best->Function->isDeleted() 6438 << ULE->getName() 6439 << Fn->getSourceRange(); 6440 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6441 break; 6442 } 6443 6444 // Overload resolution failed. Destroy all of the subexpressions and 6445 // return NULL. 6446 Fn->Destroy(Context); 6447 for (unsigned Arg = 0; Arg < NumArgs; ++Arg) 6448 Args[Arg]->Destroy(Context); 6449 return ExprError(); 6450} 6451 6452static bool IsOverloaded(const UnresolvedSetImpl &Functions) { 6453 return Functions.size() > 1 || 6454 (Functions.size() == 1 && isa<FunctionTemplateDecl>(*Functions.begin())); 6455} 6456 6457/// \brief Create a unary operation that may resolve to an overloaded 6458/// operator. 6459/// 6460/// \param OpLoc The location of the operator itself (e.g., '*'). 6461/// 6462/// \param OpcIn The UnaryOperator::Opcode that describes this 6463/// operator. 6464/// 6465/// \param Functions The set of non-member functions that will be 6466/// considered by overload resolution. The caller needs to build this 6467/// set based on the context using, e.g., 6468/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 6469/// set should not contain any member functions; those will be added 6470/// by CreateOverloadedUnaryOp(). 6471/// 6472/// \param input The input argument. 6473Sema::OwningExprResult 6474Sema::CreateOverloadedUnaryOp(SourceLocation OpLoc, unsigned OpcIn, 6475 const UnresolvedSetImpl &Fns, 6476 ExprArg input) { 6477 UnaryOperator::Opcode Opc = static_cast<UnaryOperator::Opcode>(OpcIn); 6478 Expr *Input = (Expr *)input.get(); 6479 6480 OverloadedOperatorKind Op = UnaryOperator::getOverloadedOperator(Opc); 6481 assert(Op != OO_None && "Invalid opcode for overloaded unary operator"); 6482 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 6483 6484 Expr *Args[2] = { Input, 0 }; 6485 unsigned NumArgs = 1; 6486 6487 // For post-increment and post-decrement, add the implicit '0' as 6488 // the second argument, so that we know this is a post-increment or 6489 // post-decrement. 6490 if (Opc == UnaryOperator::PostInc || Opc == UnaryOperator::PostDec) { 6491 llvm::APSInt Zero(Context.getTypeSize(Context.IntTy), false); 6492 Args[1] = new (Context) IntegerLiteral(Zero, Context.IntTy, 6493 SourceLocation()); 6494 NumArgs = 2; 6495 } 6496 6497 if (Input->isTypeDependent()) { 6498 if (Fns.empty()) 6499 return Owned(new (Context) UnaryOperator(input.takeAs<Expr>(), 6500 Opc, 6501 Context.DependentTy, 6502 OpLoc)); 6503 6504 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 6505 UnresolvedLookupExpr *Fn 6506 = UnresolvedLookupExpr::Create(Context, /*Dependent*/ true, NamingClass, 6507 0, SourceRange(), OpName, OpLoc, 6508 /*ADL*/ true, IsOverloaded(Fns), 6509 Fns.begin(), Fns.end()); 6510 input.release(); 6511 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 6512 &Args[0], NumArgs, 6513 Context.DependentTy, 6514 OpLoc)); 6515 } 6516 6517 // Build an empty overload set. 6518 OverloadCandidateSet CandidateSet(OpLoc); 6519 6520 // Add the candidates from the given function set. 6521 AddFunctionCandidates(Fns, &Args[0], NumArgs, CandidateSet, false); 6522 6523 // Add operator candidates that are member functions. 6524 AddMemberOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 6525 6526 // Add candidates from ADL. 6527 AddArgumentDependentLookupCandidates(OpName, /*Operator*/ true, 6528 Args, NumArgs, 6529 /*ExplicitTemplateArgs*/ 0, 6530 CandidateSet); 6531 6532 // Add builtin operator candidates. 6533 AddBuiltinOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 6534 6535 // Perform overload resolution. 6536 OverloadCandidateSet::iterator Best; 6537 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 6538 case OR_Success: { 6539 // We found a built-in operator or an overloaded operator. 6540 FunctionDecl *FnDecl = Best->Function; 6541 6542 if (FnDecl) { 6543 // We matched an overloaded operator. Build a call to that 6544 // operator. 6545 6546 // Convert the arguments. 6547 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 6548 CheckMemberOperatorAccess(OpLoc, Args[0], 0, Best->FoundDecl); 6549 6550 if (PerformObjectArgumentInitialization(Input, /*Qualifier=*/0, 6551 Best->FoundDecl, Method)) 6552 return ExprError(); 6553 } else { 6554 // Convert the arguments. 6555 OwningExprResult InputInit 6556 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 6557 FnDecl->getParamDecl(0)), 6558 SourceLocation(), 6559 move(input)); 6560 if (InputInit.isInvalid()) 6561 return ExprError(); 6562 6563 input = move(InputInit); 6564 Input = (Expr *)input.get(); 6565 } 6566 6567 DiagnoseUseOfDecl(Best->FoundDecl, OpLoc); 6568 6569 // Determine the result type 6570 QualType ResultTy = FnDecl->getResultType().getNonReferenceType(); 6571 6572 // Build the actual expression node. 6573 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 6574 SourceLocation()); 6575 UsualUnaryConversions(FnExpr); 6576 6577 input.release(); 6578 Args[0] = Input; 6579 ExprOwningPtr<CallExpr> TheCall(this, 6580 new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 6581 Args, NumArgs, ResultTy, OpLoc)); 6582 6583 if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall.get(), 6584 FnDecl)) 6585 return ExprError(); 6586 6587 return MaybeBindToTemporary(TheCall.release()); 6588 } else { 6589 // We matched a built-in operator. Convert the arguments, then 6590 // break out so that we will build the appropriate built-in 6591 // operator node. 6592 if (PerformImplicitConversion(Input, Best->BuiltinTypes.ParamTypes[0], 6593 Best->Conversions[0], AA_Passing)) 6594 return ExprError(); 6595 6596 break; 6597 } 6598 } 6599 6600 case OR_No_Viable_Function: 6601 // No viable function; fall through to handling this as a 6602 // built-in operator, which will produce an error message for us. 6603 break; 6604 6605 case OR_Ambiguous: 6606 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 6607 << UnaryOperator::getOpcodeStr(Opc) 6608 << Input->getSourceRange(); 6609 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, NumArgs, 6610 UnaryOperator::getOpcodeStr(Opc), OpLoc); 6611 return ExprError(); 6612 6613 case OR_Deleted: 6614 Diag(OpLoc, diag::err_ovl_deleted_oper) 6615 << Best->Function->isDeleted() 6616 << UnaryOperator::getOpcodeStr(Opc) 6617 << Input->getSourceRange(); 6618 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6619 return ExprError(); 6620 } 6621 6622 // Either we found no viable overloaded operator or we matched a 6623 // built-in operator. In either case, fall through to trying to 6624 // build a built-in operation. 6625 input.release(); 6626 return CreateBuiltinUnaryOp(OpLoc, Opc, Owned(Input)); 6627} 6628 6629/// \brief Create a binary operation that may resolve to an overloaded 6630/// operator. 6631/// 6632/// \param OpLoc The location of the operator itself (e.g., '+'). 6633/// 6634/// \param OpcIn The BinaryOperator::Opcode that describes this 6635/// operator. 6636/// 6637/// \param Functions The set of non-member functions that will be 6638/// considered by overload resolution. The caller needs to build this 6639/// set based on the context using, e.g., 6640/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 6641/// set should not contain any member functions; those will be added 6642/// by CreateOverloadedBinOp(). 6643/// 6644/// \param LHS Left-hand argument. 6645/// \param RHS Right-hand argument. 6646Sema::OwningExprResult 6647Sema::CreateOverloadedBinOp(SourceLocation OpLoc, 6648 unsigned OpcIn, 6649 const UnresolvedSetImpl &Fns, 6650 Expr *LHS, Expr *RHS) { 6651 Expr *Args[2] = { LHS, RHS }; 6652 LHS=RHS=0; //Please use only Args instead of LHS/RHS couple 6653 6654 BinaryOperator::Opcode Opc = static_cast<BinaryOperator::Opcode>(OpcIn); 6655 OverloadedOperatorKind Op = BinaryOperator::getOverloadedOperator(Opc); 6656 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 6657 6658 // If either side is type-dependent, create an appropriate dependent 6659 // expression. 6660 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 6661 if (Fns.empty()) { 6662 // If there are no functions to store, just build a dependent 6663 // BinaryOperator or CompoundAssignment. 6664 if (Opc <= BinaryOperator::Assign || Opc > BinaryOperator::OrAssign) 6665 return Owned(new (Context) BinaryOperator(Args[0], Args[1], Opc, 6666 Context.DependentTy, OpLoc)); 6667 6668 return Owned(new (Context) CompoundAssignOperator(Args[0], Args[1], Opc, 6669 Context.DependentTy, 6670 Context.DependentTy, 6671 Context.DependentTy, 6672 OpLoc)); 6673 } 6674 6675 // FIXME: save results of ADL from here? 6676 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 6677 UnresolvedLookupExpr *Fn 6678 = UnresolvedLookupExpr::Create(Context, /*Dependent*/ true, NamingClass, 6679 0, SourceRange(), OpName, OpLoc, 6680 /*ADL*/ true, IsOverloaded(Fns), 6681 Fns.begin(), Fns.end()); 6682 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 6683 Args, 2, 6684 Context.DependentTy, 6685 OpLoc)); 6686 } 6687 6688 // If this is the .* operator, which is not overloadable, just 6689 // create a built-in binary operator. 6690 if (Opc == BinaryOperator::PtrMemD) 6691 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 6692 6693 // If this is the assignment operator, we only perform overload resolution 6694 // if the left-hand side is a class or enumeration type. This is actually 6695 // a hack. The standard requires that we do overload resolution between the 6696 // various built-in candidates, but as DR507 points out, this can lead to 6697 // problems. So we do it this way, which pretty much follows what GCC does. 6698 // Note that we go the traditional code path for compound assignment forms. 6699 if (Opc==BinaryOperator::Assign && !Args[0]->getType()->isOverloadableType()) 6700 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 6701 6702 // Build an empty overload set. 6703 OverloadCandidateSet CandidateSet(OpLoc); 6704 6705 // Add the candidates from the given function set. 6706 AddFunctionCandidates(Fns, Args, 2, CandidateSet, false); 6707 6708 // Add operator candidates that are member functions. 6709 AddMemberOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 6710 6711 // Add candidates from ADL. 6712 AddArgumentDependentLookupCandidates(OpName, /*Operator*/ true, 6713 Args, 2, 6714 /*ExplicitTemplateArgs*/ 0, 6715 CandidateSet); 6716 6717 // Add builtin operator candidates. 6718 AddBuiltinOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 6719 6720 // Perform overload resolution. 6721 OverloadCandidateSet::iterator Best; 6722 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 6723 case OR_Success: { 6724 // We found a built-in operator or an overloaded operator. 6725 FunctionDecl *FnDecl = Best->Function; 6726 6727 if (FnDecl) { 6728 // We matched an overloaded operator. Build a call to that 6729 // operator. 6730 6731 // Convert the arguments. 6732 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 6733 // Best->Access is only meaningful for class members. 6734 CheckMemberOperatorAccess(OpLoc, Args[0], Args[1], Best->FoundDecl); 6735 6736 OwningExprResult Arg1 6737 = PerformCopyInitialization( 6738 InitializedEntity::InitializeParameter( 6739 FnDecl->getParamDecl(0)), 6740 SourceLocation(), 6741 Owned(Args[1])); 6742 if (Arg1.isInvalid()) 6743 return ExprError(); 6744 6745 if (PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/0, 6746 Best->FoundDecl, Method)) 6747 return ExprError(); 6748 6749 Args[1] = RHS = Arg1.takeAs<Expr>(); 6750 } else { 6751 // Convert the arguments. 6752 OwningExprResult Arg0 6753 = PerformCopyInitialization( 6754 InitializedEntity::InitializeParameter( 6755 FnDecl->getParamDecl(0)), 6756 SourceLocation(), 6757 Owned(Args[0])); 6758 if (Arg0.isInvalid()) 6759 return ExprError(); 6760 6761 OwningExprResult Arg1 6762 = PerformCopyInitialization( 6763 InitializedEntity::InitializeParameter( 6764 FnDecl->getParamDecl(1)), 6765 SourceLocation(), 6766 Owned(Args[1])); 6767 if (Arg1.isInvalid()) 6768 return ExprError(); 6769 Args[0] = LHS = Arg0.takeAs<Expr>(); 6770 Args[1] = RHS = Arg1.takeAs<Expr>(); 6771 } 6772 6773 DiagnoseUseOfDecl(Best->FoundDecl, OpLoc); 6774 6775 // Determine the result type 6776 QualType ResultTy 6777 = FnDecl->getType()->getAs<FunctionType>()->getResultType(); 6778 ResultTy = ResultTy.getNonReferenceType(); 6779 6780 // Build the actual expression node. 6781 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 6782 OpLoc); 6783 UsualUnaryConversions(FnExpr); 6784 6785 ExprOwningPtr<CXXOperatorCallExpr> 6786 TheCall(this, new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 6787 Args, 2, ResultTy, 6788 OpLoc)); 6789 6790 if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall.get(), 6791 FnDecl)) 6792 return ExprError(); 6793 6794 return MaybeBindToTemporary(TheCall.release()); 6795 } else { 6796 // We matched a built-in operator. Convert the arguments, then 6797 // break out so that we will build the appropriate built-in 6798 // operator node. 6799 if (PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 6800 Best->Conversions[0], AA_Passing) || 6801 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 6802 Best->Conversions[1], AA_Passing)) 6803 return ExprError(); 6804 6805 break; 6806 } 6807 } 6808 6809 case OR_No_Viable_Function: { 6810 // C++ [over.match.oper]p9: 6811 // If the operator is the operator , [...] and there are no 6812 // viable functions, then the operator is assumed to be the 6813 // built-in operator and interpreted according to clause 5. 6814 if (Opc == BinaryOperator::Comma) 6815 break; 6816 6817 // For class as left operand for assignment or compound assigment operator 6818 // do not fall through to handling in built-in, but report that no overloaded 6819 // assignment operator found 6820 OwningExprResult Result = ExprError(); 6821 if (Args[0]->getType()->isRecordType() && 6822 Opc >= BinaryOperator::Assign && Opc <= BinaryOperator::OrAssign) { 6823 Diag(OpLoc, diag::err_ovl_no_viable_oper) 6824 << BinaryOperator::getOpcodeStr(Opc) 6825 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 6826 } else { 6827 // No viable function; try to create a built-in operation, which will 6828 // produce an error. Then, show the non-viable candidates. 6829 Result = CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 6830 } 6831 assert(Result.isInvalid() && 6832 "C++ binary operator overloading is missing candidates!"); 6833 if (Result.isInvalid()) 6834 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2, 6835 BinaryOperator::getOpcodeStr(Opc), OpLoc); 6836 return move(Result); 6837 } 6838 6839 case OR_Ambiguous: 6840 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 6841 << BinaryOperator::getOpcodeStr(Opc) 6842 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 6843 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, 2, 6844 BinaryOperator::getOpcodeStr(Opc), OpLoc); 6845 return ExprError(); 6846 6847 case OR_Deleted: 6848 Diag(OpLoc, diag::err_ovl_deleted_oper) 6849 << Best->Function->isDeleted() 6850 << BinaryOperator::getOpcodeStr(Opc) 6851 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 6852 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2); 6853 return ExprError(); 6854 } 6855 6856 // We matched a built-in operator; build it. 6857 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 6858} 6859 6860Action::OwningExprResult 6861Sema::CreateOverloadedArraySubscriptExpr(SourceLocation LLoc, 6862 SourceLocation RLoc, 6863 ExprArg Base, ExprArg Idx) { 6864 Expr *Args[2] = { static_cast<Expr*>(Base.get()), 6865 static_cast<Expr*>(Idx.get()) }; 6866 DeclarationName OpName = 6867 Context.DeclarationNames.getCXXOperatorName(OO_Subscript); 6868 6869 // If either side is type-dependent, create an appropriate dependent 6870 // expression. 6871 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 6872 6873 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 6874 UnresolvedLookupExpr *Fn 6875 = UnresolvedLookupExpr::Create(Context, /*Dependent*/ true, NamingClass, 6876 0, SourceRange(), OpName, LLoc, 6877 /*ADL*/ true, /*Overloaded*/ false, 6878 UnresolvedSetIterator(), 6879 UnresolvedSetIterator()); 6880 // Can't add any actual overloads yet 6881 6882 Base.release(); 6883 Idx.release(); 6884 return Owned(new (Context) CXXOperatorCallExpr(Context, OO_Subscript, Fn, 6885 Args, 2, 6886 Context.DependentTy, 6887 RLoc)); 6888 } 6889 6890 // Build an empty overload set. 6891 OverloadCandidateSet CandidateSet(LLoc); 6892 6893 // Subscript can only be overloaded as a member function. 6894 6895 // Add operator candidates that are member functions. 6896 AddMemberOperatorCandidates(OO_Subscript, LLoc, Args, 2, CandidateSet); 6897 6898 // Add builtin operator candidates. 6899 AddBuiltinOperatorCandidates(OO_Subscript, LLoc, Args, 2, CandidateSet); 6900 6901 // Perform overload resolution. 6902 OverloadCandidateSet::iterator Best; 6903 switch (BestViableFunction(CandidateSet, LLoc, Best)) { 6904 case OR_Success: { 6905 // We found a built-in operator or an overloaded operator. 6906 FunctionDecl *FnDecl = Best->Function; 6907 6908 if (FnDecl) { 6909 // We matched an overloaded operator. Build a call to that 6910 // operator. 6911 6912 CheckMemberOperatorAccess(LLoc, Args[0], Args[1], Best->FoundDecl); 6913 DiagnoseUseOfDecl(Best->FoundDecl, LLoc); 6914 6915 // Convert the arguments. 6916 CXXMethodDecl *Method = cast<CXXMethodDecl>(FnDecl); 6917 if (PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/0, 6918 Best->FoundDecl, Method)) 6919 return ExprError(); 6920 6921 // Convert the arguments. 6922 OwningExprResult InputInit 6923 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 6924 FnDecl->getParamDecl(0)), 6925 SourceLocation(), 6926 Owned(Args[1])); 6927 if (InputInit.isInvalid()) 6928 return ExprError(); 6929 6930 Args[1] = InputInit.takeAs<Expr>(); 6931 6932 // Determine the result type 6933 QualType ResultTy 6934 = FnDecl->getType()->getAs<FunctionType>()->getResultType(); 6935 ResultTy = ResultTy.getNonReferenceType(); 6936 6937 // Build the actual expression node. 6938 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 6939 LLoc); 6940 UsualUnaryConversions(FnExpr); 6941 6942 Base.release(); 6943 Idx.release(); 6944 ExprOwningPtr<CXXOperatorCallExpr> 6945 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Subscript, 6946 FnExpr, Args, 2, 6947 ResultTy, RLoc)); 6948 6949 if (CheckCallReturnType(FnDecl->getResultType(), LLoc, TheCall.get(), 6950 FnDecl)) 6951 return ExprError(); 6952 6953 return MaybeBindToTemporary(TheCall.release()); 6954 } else { 6955 // We matched a built-in operator. Convert the arguments, then 6956 // break out so that we will build the appropriate built-in 6957 // operator node. 6958 if (PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 6959 Best->Conversions[0], AA_Passing) || 6960 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 6961 Best->Conversions[1], AA_Passing)) 6962 return ExprError(); 6963 6964 break; 6965 } 6966 } 6967 6968 case OR_No_Viable_Function: { 6969 if (CandidateSet.empty()) 6970 Diag(LLoc, diag::err_ovl_no_oper) 6971 << Args[0]->getType() << /*subscript*/ 0 6972 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 6973 else 6974 Diag(LLoc, diag::err_ovl_no_viable_subscript) 6975 << Args[0]->getType() 6976 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 6977 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2, 6978 "[]", LLoc); 6979 return ExprError(); 6980 } 6981 6982 case OR_Ambiguous: 6983 Diag(LLoc, diag::err_ovl_ambiguous_oper) 6984 << "[]" << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 6985 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, 2, 6986 "[]", LLoc); 6987 return ExprError(); 6988 6989 case OR_Deleted: 6990 Diag(LLoc, diag::err_ovl_deleted_oper) 6991 << Best->Function->isDeleted() << "[]" 6992 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 6993 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2, 6994 "[]", LLoc); 6995 return ExprError(); 6996 } 6997 6998 // We matched a built-in operator; build it. 6999 Base.release(); 7000 Idx.release(); 7001 return CreateBuiltinArraySubscriptExpr(Owned(Args[0]), LLoc, 7002 Owned(Args[1]), RLoc); 7003} 7004 7005/// BuildCallToMemberFunction - Build a call to a member 7006/// function. MemExpr is the expression that refers to the member 7007/// function (and includes the object parameter), Args/NumArgs are the 7008/// arguments to the function call (not including the object 7009/// parameter). The caller needs to validate that the member 7010/// expression refers to a member function or an overloaded member 7011/// function. 7012Sema::OwningExprResult 7013Sema::BuildCallToMemberFunction(Scope *S, Expr *MemExprE, 7014 SourceLocation LParenLoc, Expr **Args, 7015 unsigned NumArgs, SourceLocation *CommaLocs, 7016 SourceLocation RParenLoc) { 7017 // Dig out the member expression. This holds both the object 7018 // argument and the member function we're referring to. 7019 Expr *NakedMemExpr = MemExprE->IgnoreParens(); 7020 7021 MemberExpr *MemExpr; 7022 CXXMethodDecl *Method = 0; 7023 DeclAccessPair FoundDecl = DeclAccessPair::make(0, AS_public); 7024 NestedNameSpecifier *Qualifier = 0; 7025 if (isa<MemberExpr>(NakedMemExpr)) { 7026 MemExpr = cast<MemberExpr>(NakedMemExpr); 7027 Method = cast<CXXMethodDecl>(MemExpr->getMemberDecl()); 7028 FoundDecl = MemExpr->getFoundDecl(); 7029 Qualifier = MemExpr->getQualifier(); 7030 } else { 7031 UnresolvedMemberExpr *UnresExpr = cast<UnresolvedMemberExpr>(NakedMemExpr); 7032 Qualifier = UnresExpr->getQualifier(); 7033 7034 QualType ObjectType = UnresExpr->getBaseType(); 7035 7036 // Add overload candidates 7037 OverloadCandidateSet CandidateSet(UnresExpr->getMemberLoc()); 7038 7039 // FIXME: avoid copy. 7040 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 7041 if (UnresExpr->hasExplicitTemplateArgs()) { 7042 UnresExpr->copyTemplateArgumentsInto(TemplateArgsBuffer); 7043 TemplateArgs = &TemplateArgsBuffer; 7044 } 7045 7046 for (UnresolvedMemberExpr::decls_iterator I = UnresExpr->decls_begin(), 7047 E = UnresExpr->decls_end(); I != E; ++I) { 7048 7049 NamedDecl *Func = *I; 7050 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(Func->getDeclContext()); 7051 if (isa<UsingShadowDecl>(Func)) 7052 Func = cast<UsingShadowDecl>(Func)->getTargetDecl(); 7053 7054 if ((Method = dyn_cast<CXXMethodDecl>(Func))) { 7055 // If explicit template arguments were provided, we can't call a 7056 // non-template member function. 7057 if (TemplateArgs) 7058 continue; 7059 7060 AddMethodCandidate(Method, I.getPair(), ActingDC, ObjectType, 7061 Args, NumArgs, 7062 CandidateSet, /*SuppressUserConversions=*/false); 7063 } else { 7064 AddMethodTemplateCandidate(cast<FunctionTemplateDecl>(Func), 7065 I.getPair(), ActingDC, TemplateArgs, 7066 ObjectType, Args, NumArgs, 7067 CandidateSet, 7068 /*SuppressUsedConversions=*/false); 7069 } 7070 } 7071 7072 DeclarationName DeclName = UnresExpr->getMemberName(); 7073 7074 OverloadCandidateSet::iterator Best; 7075 switch (BestViableFunction(CandidateSet, UnresExpr->getLocStart(), Best)) { 7076 case OR_Success: 7077 Method = cast<CXXMethodDecl>(Best->Function); 7078 FoundDecl = Best->FoundDecl; 7079 CheckUnresolvedMemberAccess(UnresExpr, Best->FoundDecl); 7080 DiagnoseUseOfDecl(Best->FoundDecl, UnresExpr->getNameLoc()); 7081 break; 7082 7083 case OR_No_Viable_Function: 7084 Diag(UnresExpr->getMemberLoc(), 7085 diag::err_ovl_no_viable_member_function_in_call) 7086 << DeclName << MemExprE->getSourceRange(); 7087 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 7088 // FIXME: Leaking incoming expressions! 7089 return ExprError(); 7090 7091 case OR_Ambiguous: 7092 Diag(UnresExpr->getMemberLoc(), diag::err_ovl_ambiguous_member_call) 7093 << DeclName << MemExprE->getSourceRange(); 7094 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 7095 // FIXME: Leaking incoming expressions! 7096 return ExprError(); 7097 7098 case OR_Deleted: 7099 Diag(UnresExpr->getMemberLoc(), diag::err_ovl_deleted_member_call) 7100 << Best->Function->isDeleted() 7101 << DeclName << MemExprE->getSourceRange(); 7102 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 7103 // FIXME: Leaking incoming expressions! 7104 return ExprError(); 7105 } 7106 7107 MemExprE = FixOverloadedFunctionReference(MemExprE, FoundDecl, Method); 7108 7109 // If overload resolution picked a static member, build a 7110 // non-member call based on that function. 7111 if (Method->isStatic()) { 7112 return BuildResolvedCallExpr(MemExprE, Method, LParenLoc, 7113 Args, NumArgs, RParenLoc); 7114 } 7115 7116 MemExpr = cast<MemberExpr>(MemExprE->IgnoreParens()); 7117 } 7118 7119 assert(Method && "Member call to something that isn't a method?"); 7120 ExprOwningPtr<CXXMemberCallExpr> 7121 TheCall(this, new (Context) CXXMemberCallExpr(Context, MemExprE, Args, 7122 NumArgs, 7123 Method->getResultType().getNonReferenceType(), 7124 RParenLoc)); 7125 7126 // Check for a valid return type. 7127 if (CheckCallReturnType(Method->getResultType(), MemExpr->getMemberLoc(), 7128 TheCall.get(), Method)) 7129 return ExprError(); 7130 7131 // Convert the object argument (for a non-static member function call). 7132 // We only need to do this if there was actually an overload; otherwise 7133 // it was done at lookup. 7134 Expr *ObjectArg = MemExpr->getBase(); 7135 if (!Method->isStatic() && 7136 PerformObjectArgumentInitialization(ObjectArg, Qualifier, 7137 FoundDecl, Method)) 7138 return ExprError(); 7139 MemExpr->setBase(ObjectArg); 7140 7141 // Convert the rest of the arguments 7142 const FunctionProtoType *Proto = Method->getType()->getAs<FunctionProtoType>(); 7143 if (ConvertArgumentsForCall(&*TheCall, MemExpr, Method, Proto, Args, NumArgs, 7144 RParenLoc)) 7145 return ExprError(); 7146 7147 if (CheckFunctionCall(Method, TheCall.get())) 7148 return ExprError(); 7149 7150 return MaybeBindToTemporary(TheCall.release()); 7151} 7152 7153/// BuildCallToObjectOfClassType - Build a call to an object of class 7154/// type (C++ [over.call.object]), which can end up invoking an 7155/// overloaded function call operator (@c operator()) or performing a 7156/// user-defined conversion on the object argument. 7157Sema::ExprResult 7158Sema::BuildCallToObjectOfClassType(Scope *S, Expr *Object, 7159 SourceLocation LParenLoc, 7160 Expr **Args, unsigned NumArgs, 7161 SourceLocation *CommaLocs, 7162 SourceLocation RParenLoc) { 7163 assert(Object->getType()->isRecordType() && "Requires object type argument"); 7164 const RecordType *Record = Object->getType()->getAs<RecordType>(); 7165 7166 // C++ [over.call.object]p1: 7167 // If the primary-expression E in the function call syntax 7168 // evaluates to a class object of type "cv T", then the set of 7169 // candidate functions includes at least the function call 7170 // operators of T. The function call operators of T are obtained by 7171 // ordinary lookup of the name operator() in the context of 7172 // (E).operator(). 7173 OverloadCandidateSet CandidateSet(LParenLoc); 7174 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Call); 7175 7176 if (RequireCompleteType(LParenLoc, Object->getType(), 7177 PDiag(diag::err_incomplete_object_call) 7178 << Object->getSourceRange())) 7179 return true; 7180 7181 LookupResult R(*this, OpName, LParenLoc, LookupOrdinaryName); 7182 LookupQualifiedName(R, Record->getDecl()); 7183 R.suppressDiagnostics(); 7184 7185 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 7186 Oper != OperEnd; ++Oper) { 7187 AddMethodCandidate(Oper.getPair(), Object->getType(), 7188 Args, NumArgs, CandidateSet, 7189 /*SuppressUserConversions=*/ false); 7190 } 7191 7192 // C++ [over.call.object]p2: 7193 // In addition, for each conversion function declared in T of the 7194 // form 7195 // 7196 // operator conversion-type-id () cv-qualifier; 7197 // 7198 // where cv-qualifier is the same cv-qualification as, or a 7199 // greater cv-qualification than, cv, and where conversion-type-id 7200 // denotes the type "pointer to function of (P1,...,Pn) returning 7201 // R", or the type "reference to pointer to function of 7202 // (P1,...,Pn) returning R", or the type "reference to function 7203 // of (P1,...,Pn) returning R", a surrogate call function [...] 7204 // is also considered as a candidate function. Similarly, 7205 // surrogate call functions are added to the set of candidate 7206 // functions for each conversion function declared in an 7207 // accessible base class provided the function is not hidden 7208 // within T by another intervening declaration. 7209 const UnresolvedSetImpl *Conversions 7210 = cast<CXXRecordDecl>(Record->getDecl())->getVisibleConversionFunctions(); 7211 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 7212 E = Conversions->end(); I != E; ++I) { 7213 NamedDecl *D = *I; 7214 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext()); 7215 if (isa<UsingShadowDecl>(D)) 7216 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 7217 7218 // Skip over templated conversion functions; they aren't 7219 // surrogates. 7220 if (isa<FunctionTemplateDecl>(D)) 7221 continue; 7222 7223 CXXConversionDecl *Conv = cast<CXXConversionDecl>(D); 7224 7225 // Strip the reference type (if any) and then the pointer type (if 7226 // any) to get down to what might be a function type. 7227 QualType ConvType = Conv->getConversionType().getNonReferenceType(); 7228 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 7229 ConvType = ConvPtrType->getPointeeType(); 7230 7231 if (const FunctionProtoType *Proto = ConvType->getAs<FunctionProtoType>()) 7232 AddSurrogateCandidate(Conv, I.getPair(), ActingContext, Proto, 7233 Object->getType(), Args, NumArgs, 7234 CandidateSet); 7235 } 7236 7237 // Perform overload resolution. 7238 OverloadCandidateSet::iterator Best; 7239 switch (BestViableFunction(CandidateSet, Object->getLocStart(), Best)) { 7240 case OR_Success: 7241 // Overload resolution succeeded; we'll build the appropriate call 7242 // below. 7243 break; 7244 7245 case OR_No_Viable_Function: 7246 if (CandidateSet.empty()) 7247 Diag(Object->getSourceRange().getBegin(), diag::err_ovl_no_oper) 7248 << Object->getType() << /*call*/ 1 7249 << Object->getSourceRange(); 7250 else 7251 Diag(Object->getSourceRange().getBegin(), 7252 diag::err_ovl_no_viable_object_call) 7253 << Object->getType() << Object->getSourceRange(); 7254 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 7255 break; 7256 7257 case OR_Ambiguous: 7258 Diag(Object->getSourceRange().getBegin(), 7259 diag::err_ovl_ambiguous_object_call) 7260 << Object->getType() << Object->getSourceRange(); 7261 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, NumArgs); 7262 break; 7263 7264 case OR_Deleted: 7265 Diag(Object->getSourceRange().getBegin(), 7266 diag::err_ovl_deleted_object_call) 7267 << Best->Function->isDeleted() 7268 << Object->getType() << Object->getSourceRange(); 7269 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 7270 break; 7271 } 7272 7273 if (Best == CandidateSet.end()) { 7274 // We had an error; delete all of the subexpressions and return 7275 // the error. 7276 Object->Destroy(Context); 7277 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 7278 Args[ArgIdx]->Destroy(Context); 7279 return true; 7280 } 7281 7282 if (Best->Function == 0) { 7283 // Since there is no function declaration, this is one of the 7284 // surrogate candidates. Dig out the conversion function. 7285 CXXConversionDecl *Conv 7286 = cast<CXXConversionDecl>( 7287 Best->Conversions[0].UserDefined.ConversionFunction); 7288 7289 CheckMemberOperatorAccess(LParenLoc, Object, 0, Best->FoundDecl); 7290 DiagnoseUseOfDecl(Best->FoundDecl, LParenLoc); 7291 7292 // We selected one of the surrogate functions that converts the 7293 // object parameter to a function pointer. Perform the conversion 7294 // on the object argument, then let ActOnCallExpr finish the job. 7295 7296 // Create an implicit member expr to refer to the conversion operator. 7297 // and then call it. 7298 CXXMemberCallExpr *CE = BuildCXXMemberCallExpr(Object, Best->FoundDecl, 7299 Conv); 7300 7301 return ActOnCallExpr(S, ExprArg(*this, CE), LParenLoc, 7302 MultiExprArg(*this, (ExprTy**)Args, NumArgs), 7303 CommaLocs, RParenLoc).result(); 7304 } 7305 7306 CheckMemberOperatorAccess(LParenLoc, Object, 0, Best->FoundDecl); 7307 DiagnoseUseOfDecl(Best->FoundDecl, LParenLoc); 7308 7309 // We found an overloaded operator(). Build a CXXOperatorCallExpr 7310 // that calls this method, using Object for the implicit object 7311 // parameter and passing along the remaining arguments. 7312 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 7313 const FunctionProtoType *Proto = Method->getType()->getAs<FunctionProtoType>(); 7314 7315 unsigned NumArgsInProto = Proto->getNumArgs(); 7316 unsigned NumArgsToCheck = NumArgs; 7317 7318 // Build the full argument list for the method call (the 7319 // implicit object parameter is placed at the beginning of the 7320 // list). 7321 Expr **MethodArgs; 7322 if (NumArgs < NumArgsInProto) { 7323 NumArgsToCheck = NumArgsInProto; 7324 MethodArgs = new Expr*[NumArgsInProto + 1]; 7325 } else { 7326 MethodArgs = new Expr*[NumArgs + 1]; 7327 } 7328 MethodArgs[0] = Object; 7329 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 7330 MethodArgs[ArgIdx + 1] = Args[ArgIdx]; 7331 7332 Expr *NewFn = new (Context) DeclRefExpr(Method, Method->getType(), 7333 SourceLocation()); 7334 UsualUnaryConversions(NewFn); 7335 7336 // Once we've built TheCall, all of the expressions are properly 7337 // owned. 7338 QualType ResultTy = Method->getResultType().getNonReferenceType(); 7339 ExprOwningPtr<CXXOperatorCallExpr> 7340 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Call, NewFn, 7341 MethodArgs, NumArgs + 1, 7342 ResultTy, RParenLoc)); 7343 delete [] MethodArgs; 7344 7345 if (CheckCallReturnType(Method->getResultType(), LParenLoc, TheCall.get(), 7346 Method)) 7347 return true; 7348 7349 // We may have default arguments. If so, we need to allocate more 7350 // slots in the call for them. 7351 if (NumArgs < NumArgsInProto) 7352 TheCall->setNumArgs(Context, NumArgsInProto + 1); 7353 else if (NumArgs > NumArgsInProto) 7354 NumArgsToCheck = NumArgsInProto; 7355 7356 bool IsError = false; 7357 7358 // Initialize the implicit object parameter. 7359 IsError |= PerformObjectArgumentInitialization(Object, /*Qualifier=*/0, 7360 Best->FoundDecl, Method); 7361 TheCall->setArg(0, Object); 7362 7363 7364 // Check the argument types. 7365 for (unsigned i = 0; i != NumArgsToCheck; i++) { 7366 Expr *Arg; 7367 if (i < NumArgs) { 7368 Arg = Args[i]; 7369 7370 // Pass the argument. 7371 7372 OwningExprResult InputInit 7373 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 7374 Method->getParamDecl(i)), 7375 SourceLocation(), Owned(Arg)); 7376 7377 IsError |= InputInit.isInvalid(); 7378 Arg = InputInit.takeAs<Expr>(); 7379 } else { 7380 OwningExprResult DefArg 7381 = BuildCXXDefaultArgExpr(LParenLoc, Method, Method->getParamDecl(i)); 7382 if (DefArg.isInvalid()) { 7383 IsError = true; 7384 break; 7385 } 7386 7387 Arg = DefArg.takeAs<Expr>(); 7388 } 7389 7390 TheCall->setArg(i + 1, Arg); 7391 } 7392 7393 // If this is a variadic call, handle args passed through "...". 7394 if (Proto->isVariadic()) { 7395 // Promote the arguments (C99 6.5.2.2p7). 7396 for (unsigned i = NumArgsInProto; i != NumArgs; i++) { 7397 Expr *Arg = Args[i]; 7398 IsError |= DefaultVariadicArgumentPromotion(Arg, VariadicMethod, 0); 7399 TheCall->setArg(i + 1, Arg); 7400 } 7401 } 7402 7403 if (IsError) return true; 7404 7405 if (CheckFunctionCall(Method, TheCall.get())) 7406 return true; 7407 7408 return MaybeBindToTemporary(TheCall.release()).result(); 7409} 7410 7411/// BuildOverloadedArrowExpr - Build a call to an overloaded @c operator-> 7412/// (if one exists), where @c Base is an expression of class type and 7413/// @c Member is the name of the member we're trying to find. 7414Sema::OwningExprResult 7415Sema::BuildOverloadedArrowExpr(Scope *S, ExprArg BaseIn, SourceLocation OpLoc) { 7416 Expr *Base = static_cast<Expr *>(BaseIn.get()); 7417 assert(Base->getType()->isRecordType() && "left-hand side must have class type"); 7418 7419 SourceLocation Loc = Base->getExprLoc(); 7420 7421 // C++ [over.ref]p1: 7422 // 7423 // [...] An expression x->m is interpreted as (x.operator->())->m 7424 // for a class object x of type T if T::operator->() exists and if 7425 // the operator is selected as the best match function by the 7426 // overload resolution mechanism (13.3). 7427 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Arrow); 7428 OverloadCandidateSet CandidateSet(Loc); 7429 const RecordType *BaseRecord = Base->getType()->getAs<RecordType>(); 7430 7431 if (RequireCompleteType(Loc, Base->getType(), 7432 PDiag(diag::err_typecheck_incomplete_tag) 7433 << Base->getSourceRange())) 7434 return ExprError(); 7435 7436 LookupResult R(*this, OpName, OpLoc, LookupOrdinaryName); 7437 LookupQualifiedName(R, BaseRecord->getDecl()); 7438 R.suppressDiagnostics(); 7439 7440 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 7441 Oper != OperEnd; ++Oper) { 7442 AddMethodCandidate(Oper.getPair(), Base->getType(), 0, 0, CandidateSet, 7443 /*SuppressUserConversions=*/false); 7444 } 7445 7446 // Perform overload resolution. 7447 OverloadCandidateSet::iterator Best; 7448 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 7449 case OR_Success: 7450 // Overload resolution succeeded; we'll build the call below. 7451 break; 7452 7453 case OR_No_Viable_Function: 7454 if (CandidateSet.empty()) 7455 Diag(OpLoc, diag::err_typecheck_member_reference_arrow) 7456 << Base->getType() << Base->getSourceRange(); 7457 else 7458 Diag(OpLoc, diag::err_ovl_no_viable_oper) 7459 << "operator->" << Base->getSourceRange(); 7460 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, &Base, 1); 7461 return ExprError(); 7462 7463 case OR_Ambiguous: 7464 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 7465 << "->" << Base->getSourceRange(); 7466 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, &Base, 1); 7467 return ExprError(); 7468 7469 case OR_Deleted: 7470 Diag(OpLoc, diag::err_ovl_deleted_oper) 7471 << Best->Function->isDeleted() 7472 << "->" << Base->getSourceRange(); 7473 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, &Base, 1); 7474 return ExprError(); 7475 } 7476 7477 CheckMemberOperatorAccess(OpLoc, Base, 0, Best->FoundDecl); 7478 DiagnoseUseOfDecl(Best->FoundDecl, OpLoc); 7479 7480 // Convert the object parameter. 7481 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 7482 if (PerformObjectArgumentInitialization(Base, /*Qualifier=*/0, 7483 Best->FoundDecl, Method)) 7484 return ExprError(); 7485 7486 // No concerns about early exits now. 7487 BaseIn.release(); 7488 7489 // Build the operator call. 7490 Expr *FnExpr = new (Context) DeclRefExpr(Method, Method->getType(), 7491 SourceLocation()); 7492 UsualUnaryConversions(FnExpr); 7493 7494 QualType ResultTy = Method->getResultType().getNonReferenceType(); 7495 ExprOwningPtr<CXXOperatorCallExpr> 7496 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Arrow, FnExpr, 7497 &Base, 1, ResultTy, OpLoc)); 7498 7499 if (CheckCallReturnType(Method->getResultType(), OpLoc, TheCall.get(), 7500 Method)) 7501 return ExprError(); 7502 return move(TheCall); 7503} 7504 7505/// FixOverloadedFunctionReference - E is an expression that refers to 7506/// a C++ overloaded function (possibly with some parentheses and 7507/// perhaps a '&' around it). We have resolved the overloaded function 7508/// to the function declaration Fn, so patch up the expression E to 7509/// refer (possibly indirectly) to Fn. Returns the new expr. 7510Expr *Sema::FixOverloadedFunctionReference(Expr *E, DeclAccessPair Found, 7511 FunctionDecl *Fn) { 7512 if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) { 7513 Expr *SubExpr = FixOverloadedFunctionReference(PE->getSubExpr(), 7514 Found, Fn); 7515 if (SubExpr == PE->getSubExpr()) 7516 return PE->Retain(); 7517 7518 return new (Context) ParenExpr(PE->getLParen(), PE->getRParen(), SubExpr); 7519 } 7520 7521 if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) { 7522 Expr *SubExpr = FixOverloadedFunctionReference(ICE->getSubExpr(), 7523 Found, Fn); 7524 assert(Context.hasSameType(ICE->getSubExpr()->getType(), 7525 SubExpr->getType()) && 7526 "Implicit cast type cannot be determined from overload"); 7527 if (SubExpr == ICE->getSubExpr()) 7528 return ICE->Retain(); 7529 7530 return new (Context) ImplicitCastExpr(ICE->getType(), 7531 ICE->getCastKind(), 7532 SubExpr, CXXBaseSpecifierArray(), 7533 ICE->isLvalueCast()); 7534 } 7535 7536 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(E)) { 7537 assert(UnOp->getOpcode() == UnaryOperator::AddrOf && 7538 "Can only take the address of an overloaded function"); 7539 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 7540 if (Method->isStatic()) { 7541 // Do nothing: static member functions aren't any different 7542 // from non-member functions. 7543 } else { 7544 // Fix the sub expression, which really has to be an 7545 // UnresolvedLookupExpr holding an overloaded member function 7546 // or template. 7547 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(), 7548 Found, Fn); 7549 if (SubExpr == UnOp->getSubExpr()) 7550 return UnOp->Retain(); 7551 7552 assert(isa<DeclRefExpr>(SubExpr) 7553 && "fixed to something other than a decl ref"); 7554 assert(cast<DeclRefExpr>(SubExpr)->getQualifier() 7555 && "fixed to a member ref with no nested name qualifier"); 7556 7557 // We have taken the address of a pointer to member 7558 // function. Perform the computation here so that we get the 7559 // appropriate pointer to member type. 7560 QualType ClassType 7561 = Context.getTypeDeclType(cast<RecordDecl>(Method->getDeclContext())); 7562 QualType MemPtrType 7563 = Context.getMemberPointerType(Fn->getType(), ClassType.getTypePtr()); 7564 7565 return new (Context) UnaryOperator(SubExpr, UnaryOperator::AddrOf, 7566 MemPtrType, UnOp->getOperatorLoc()); 7567 } 7568 } 7569 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(), 7570 Found, Fn); 7571 if (SubExpr == UnOp->getSubExpr()) 7572 return UnOp->Retain(); 7573 7574 return new (Context) UnaryOperator(SubExpr, UnaryOperator::AddrOf, 7575 Context.getPointerType(SubExpr->getType()), 7576 UnOp->getOperatorLoc()); 7577 } 7578 7579 if (UnresolvedLookupExpr *ULE = dyn_cast<UnresolvedLookupExpr>(E)) { 7580 // FIXME: avoid copy. 7581 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 7582 if (ULE->hasExplicitTemplateArgs()) { 7583 ULE->copyTemplateArgumentsInto(TemplateArgsBuffer); 7584 TemplateArgs = &TemplateArgsBuffer; 7585 } 7586 7587 return DeclRefExpr::Create(Context, 7588 ULE->getQualifier(), 7589 ULE->getQualifierRange(), 7590 Fn, 7591 ULE->getNameLoc(), 7592 Fn->getType(), 7593 TemplateArgs); 7594 } 7595 7596 if (UnresolvedMemberExpr *MemExpr = dyn_cast<UnresolvedMemberExpr>(E)) { 7597 // FIXME: avoid copy. 7598 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 7599 if (MemExpr->hasExplicitTemplateArgs()) { 7600 MemExpr->copyTemplateArgumentsInto(TemplateArgsBuffer); 7601 TemplateArgs = &TemplateArgsBuffer; 7602 } 7603 7604 Expr *Base; 7605 7606 // If we're filling in 7607 if (MemExpr->isImplicitAccess()) { 7608 if (cast<CXXMethodDecl>(Fn)->isStatic()) { 7609 return DeclRefExpr::Create(Context, 7610 MemExpr->getQualifier(), 7611 MemExpr->getQualifierRange(), 7612 Fn, 7613 MemExpr->getMemberLoc(), 7614 Fn->getType(), 7615 TemplateArgs); 7616 } else { 7617 SourceLocation Loc = MemExpr->getMemberLoc(); 7618 if (MemExpr->getQualifier()) 7619 Loc = MemExpr->getQualifierRange().getBegin(); 7620 Base = new (Context) CXXThisExpr(Loc, 7621 MemExpr->getBaseType(), 7622 /*isImplicit=*/true); 7623 } 7624 } else 7625 Base = MemExpr->getBase()->Retain(); 7626 7627 return MemberExpr::Create(Context, Base, 7628 MemExpr->isArrow(), 7629 MemExpr->getQualifier(), 7630 MemExpr->getQualifierRange(), 7631 Fn, 7632 Found, 7633 MemExpr->getMemberLoc(), 7634 TemplateArgs, 7635 Fn->getType()); 7636 } 7637 7638 assert(false && "Invalid reference to overloaded function"); 7639 return E->Retain(); 7640} 7641 7642Sema::OwningExprResult Sema::FixOverloadedFunctionReference(OwningExprResult E, 7643 DeclAccessPair Found, 7644 FunctionDecl *Fn) { 7645 return Owned(FixOverloadedFunctionReference((Expr *)E.get(), Found, Fn)); 7646} 7647 7648} // end namespace clang 7649