SemaOverload.cpp revision 9d3347a5887d2d25afe8b0bd35783a72ec86cce2
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. 503Sema::OverloadKind 504Sema::CheckOverload(FunctionDecl *New, const LookupResult &Old, 505 NamedDecl *&Match) { 506 for (LookupResult::iterator I = Old.begin(), E = Old.end(); 507 I != E; ++I) { 508 NamedDecl *OldD = (*I)->getUnderlyingDecl(); 509 if (FunctionTemplateDecl *OldT = dyn_cast<FunctionTemplateDecl>(OldD)) { 510 if (!IsOverload(New, OldT->getTemplatedDecl())) { 511 Match = *I; 512 return Ovl_Match; 513 } 514 } else if (FunctionDecl *OldF = dyn_cast<FunctionDecl>(OldD)) { 515 if (!IsOverload(New, OldF)) { 516 Match = *I; 517 return Ovl_Match; 518 } 519 } else if (isa<UsingDecl>(OldD) || isa<TagDecl>(OldD)) { 520 // We can overload with these, which can show up when doing 521 // redeclaration checks for UsingDecls. 522 assert(Old.getLookupKind() == LookupUsingDeclName); 523 } else if (isa<UnresolvedUsingValueDecl>(OldD)) { 524 // Optimistically assume that an unresolved using decl will 525 // overload; if it doesn't, we'll have to diagnose during 526 // template instantiation. 527 } else { 528 // (C++ 13p1): 529 // Only function declarations can be overloaded; object and type 530 // declarations cannot be overloaded. 531 Match = *I; 532 return Ovl_NonFunction; 533 } 534 } 535 536 return Ovl_Overload; 537} 538 539bool Sema::IsOverload(FunctionDecl *New, FunctionDecl *Old) { 540 FunctionTemplateDecl *OldTemplate = Old->getDescribedFunctionTemplate(); 541 FunctionTemplateDecl *NewTemplate = New->getDescribedFunctionTemplate(); 542 543 // C++ [temp.fct]p2: 544 // A function template can be overloaded with other function templates 545 // and with normal (non-template) functions. 546 if ((OldTemplate == 0) != (NewTemplate == 0)) 547 return true; 548 549 // Is the function New an overload of the function Old? 550 QualType OldQType = Context.getCanonicalType(Old->getType()); 551 QualType NewQType = Context.getCanonicalType(New->getType()); 552 553 // Compare the signatures (C++ 1.3.10) of the two functions to 554 // determine whether they are overloads. If we find any mismatch 555 // in the signature, they are overloads. 556 557 // If either of these functions is a K&R-style function (no 558 // prototype), then we consider them to have matching signatures. 559 if (isa<FunctionNoProtoType>(OldQType.getTypePtr()) || 560 isa<FunctionNoProtoType>(NewQType.getTypePtr())) 561 return false; 562 563 FunctionProtoType* OldType = cast<FunctionProtoType>(OldQType); 564 FunctionProtoType* NewType = cast<FunctionProtoType>(NewQType); 565 566 // The signature of a function includes the types of its 567 // parameters (C++ 1.3.10), which includes the presence or absence 568 // of the ellipsis; see C++ DR 357). 569 if (OldQType != NewQType && 570 (OldType->getNumArgs() != NewType->getNumArgs() || 571 OldType->isVariadic() != NewType->isVariadic() || 572 !FunctionArgTypesAreEqual(OldType, NewType))) 573 return true; 574 575 // C++ [temp.over.link]p4: 576 // The signature of a function template consists of its function 577 // signature, its return type and its template parameter list. The names 578 // of the template parameters are significant only for establishing the 579 // relationship between the template parameters and the rest of the 580 // signature. 581 // 582 // We check the return type and template parameter lists for function 583 // templates first; the remaining checks follow. 584 if (NewTemplate && 585 (!TemplateParameterListsAreEqual(NewTemplate->getTemplateParameters(), 586 OldTemplate->getTemplateParameters(), 587 false, TPL_TemplateMatch) || 588 OldType->getResultType() != NewType->getResultType())) 589 return true; 590 591 // If the function is a class member, its signature includes the 592 // cv-qualifiers (if any) on the function itself. 593 // 594 // As part of this, also check whether one of the member functions 595 // is static, in which case they are not overloads (C++ 596 // 13.1p2). While not part of the definition of the signature, 597 // this check is important to determine whether these functions 598 // can be overloaded. 599 CXXMethodDecl* OldMethod = dyn_cast<CXXMethodDecl>(Old); 600 CXXMethodDecl* NewMethod = dyn_cast<CXXMethodDecl>(New); 601 if (OldMethod && NewMethod && 602 !OldMethod->isStatic() && !NewMethod->isStatic() && 603 OldMethod->getTypeQualifiers() != NewMethod->getTypeQualifiers()) 604 return true; 605 606 // The signatures match; this is not an overload. 607 return false; 608} 609 610/// TryImplicitConversion - Attempt to perform an implicit conversion 611/// from the given expression (Expr) to the given type (ToType). This 612/// function returns an implicit conversion sequence that can be used 613/// to perform the initialization. Given 614/// 615/// void f(float f); 616/// void g(int i) { f(i); } 617/// 618/// this routine would produce an implicit conversion sequence to 619/// describe the initialization of f from i, which will be a standard 620/// conversion sequence containing an lvalue-to-rvalue conversion (C++ 621/// 4.1) followed by a floating-integral conversion (C++ 4.9). 622// 623/// Note that this routine only determines how the conversion can be 624/// performed; it does not actually perform the conversion. As such, 625/// it will not produce any diagnostics if no conversion is available, 626/// but will instead return an implicit conversion sequence of kind 627/// "BadConversion". 628/// 629/// If @p SuppressUserConversions, then user-defined conversions are 630/// not permitted. 631/// If @p AllowExplicit, then explicit user-defined conversions are 632/// permitted. 633ImplicitConversionSequence 634Sema::TryImplicitConversion(Expr* From, QualType ToType, 635 bool SuppressUserConversions, 636 bool AllowExplicit, 637 bool InOverloadResolution) { 638 ImplicitConversionSequence ICS; 639 if (IsStandardConversion(From, ToType, InOverloadResolution, ICS.Standard)) { 640 ICS.setStandard(); 641 return ICS; 642 } 643 644 if (!getLangOptions().CPlusPlus) { 645 ICS.setBad(BadConversionSequence::no_conversion, From, ToType); 646 return ICS; 647 } 648 649 if (SuppressUserConversions) { 650 // C++ [over.ics.user]p4: 651 // A conversion of an expression of class type to the same class 652 // type is given Exact Match rank, and a conversion of an 653 // expression of class type to a base class of that type is 654 // given Conversion rank, in spite of the fact that a copy/move 655 // constructor (i.e., a user-defined conversion function) is 656 // called for those cases. 657 QualType FromType = From->getType(); 658 if (!ToType->getAs<RecordType>() || !FromType->getAs<RecordType>() || 659 !(Context.hasSameUnqualifiedType(FromType, ToType) || 660 IsDerivedFrom(FromType, ToType))) { 661 // We're not in the case above, so there is no conversion that 662 // we can perform. 663 ICS.setBad(BadConversionSequence::no_conversion, From, ToType); 664 return ICS; 665 } 666 667 ICS.setStandard(); 668 ICS.Standard.setAsIdentityConversion(); 669 ICS.Standard.setFromType(FromType); 670 ICS.Standard.setAllToTypes(ToType); 671 672 // We don't actually check at this point whether there is a valid 673 // copy/move constructor, since overloading just assumes that it 674 // exists. When we actually perform initialization, we'll find the 675 // appropriate constructor to copy the returned object, if needed. 676 ICS.Standard.CopyConstructor = 0; 677 678 // Determine whether this is considered a derived-to-base conversion. 679 if (!Context.hasSameUnqualifiedType(FromType, ToType)) 680 ICS.Standard.Second = ICK_Derived_To_Base; 681 682 return ICS; 683 } 684 685 // Attempt user-defined conversion. 686 OverloadCandidateSet Conversions(From->getExprLoc()); 687 OverloadingResult UserDefResult 688 = IsUserDefinedConversion(From, ToType, ICS.UserDefined, Conversions, 689 AllowExplicit); 690 691 if (UserDefResult == OR_Success) { 692 ICS.setUserDefined(); 693 // C++ [over.ics.user]p4: 694 // A conversion of an expression of class type to the same class 695 // type is given Exact Match rank, and a conversion of an 696 // expression of class type to a base class of that type is 697 // given Conversion rank, in spite of the fact that a copy 698 // constructor (i.e., a user-defined conversion function) is 699 // called for those cases. 700 if (CXXConstructorDecl *Constructor 701 = dyn_cast<CXXConstructorDecl>(ICS.UserDefined.ConversionFunction)) { 702 QualType FromCanon 703 = Context.getCanonicalType(From->getType().getUnqualifiedType()); 704 QualType ToCanon = Context.getCanonicalType(ToType).getUnqualifiedType(); 705 if (Constructor->isCopyConstructor() && 706 (FromCanon == ToCanon || IsDerivedFrom(FromCanon, ToCanon))) { 707 // Turn this into a "standard" conversion sequence, so that it 708 // gets ranked with standard conversion sequences. 709 ICS.setStandard(); 710 ICS.Standard.setAsIdentityConversion(); 711 ICS.Standard.setFromType(From->getType()); 712 ICS.Standard.setAllToTypes(ToType); 713 ICS.Standard.CopyConstructor = Constructor; 714 if (ToCanon != FromCanon) 715 ICS.Standard.Second = ICK_Derived_To_Base; 716 } 717 } 718 719 // C++ [over.best.ics]p4: 720 // However, when considering the argument of a user-defined 721 // conversion function that is a candidate by 13.3.1.3 when 722 // invoked for the copying of the temporary in the second step 723 // of a class copy-initialization, or by 13.3.1.4, 13.3.1.5, or 724 // 13.3.1.6 in all cases, only standard conversion sequences and 725 // ellipsis conversion sequences are allowed. 726 if (SuppressUserConversions && ICS.isUserDefined()) { 727 ICS.setBad(BadConversionSequence::suppressed_user, From, ToType); 728 } 729 } else if (UserDefResult == OR_Ambiguous && !SuppressUserConversions) { 730 ICS.setAmbiguous(); 731 ICS.Ambiguous.setFromType(From->getType()); 732 ICS.Ambiguous.setToType(ToType); 733 for (OverloadCandidateSet::iterator Cand = Conversions.begin(); 734 Cand != Conversions.end(); ++Cand) 735 if (Cand->Viable) 736 ICS.Ambiguous.addConversion(Cand->Function); 737 } else { 738 ICS.setBad(BadConversionSequence::no_conversion, From, ToType); 739 } 740 741 return ICS; 742} 743 744/// PerformImplicitConversion - Perform an implicit conversion of the 745/// expression From to the type ToType. Returns true if there was an 746/// error, false otherwise. The expression From is replaced with the 747/// converted expression. Flavor is the kind of conversion we're 748/// performing, used in the error message. If @p AllowExplicit, 749/// explicit user-defined conversions are permitted. 750bool 751Sema::PerformImplicitConversion(Expr *&From, QualType ToType, 752 AssignmentAction Action, bool AllowExplicit) { 753 ImplicitConversionSequence ICS; 754 return PerformImplicitConversion(From, ToType, Action, AllowExplicit, ICS); 755} 756 757bool 758Sema::PerformImplicitConversion(Expr *&From, QualType ToType, 759 AssignmentAction Action, bool AllowExplicit, 760 ImplicitConversionSequence& ICS) { 761 ICS = TryImplicitConversion(From, ToType, 762 /*SuppressUserConversions=*/false, 763 AllowExplicit, 764 /*InOverloadResolution=*/false); 765 return PerformImplicitConversion(From, ToType, ICS, Action); 766} 767 768/// \brief Determine whether the conversion from FromType to ToType is a valid 769/// conversion that strips "noreturn" off the nested function type. 770static bool IsNoReturnConversion(ASTContext &Context, QualType FromType, 771 QualType ToType, QualType &ResultTy) { 772 if (Context.hasSameUnqualifiedType(FromType, ToType)) 773 return false; 774 775 // Strip the noreturn off the type we're converting from; noreturn can 776 // safely be removed. 777 FromType = Context.getNoReturnType(FromType, false); 778 if (!Context.hasSameUnqualifiedType(FromType, ToType)) 779 return false; 780 781 ResultTy = FromType; 782 return true; 783} 784 785/// \brief Determine whether the conversion from FromType to ToType is a valid 786/// vector conversion. 787/// 788/// \param ICK Will be set to the vector conversion kind, if this is a vector 789/// conversion. 790static bool IsVectorConversion(ASTContext &Context, QualType FromType, 791 QualType ToType, ImplicitConversionKind &ICK) { 792 // We need at least one of these types to be a vector type to have a vector 793 // conversion. 794 if (!ToType->isVectorType() && !FromType->isVectorType()) 795 return false; 796 797 // Identical types require no conversions. 798 if (Context.hasSameUnqualifiedType(FromType, ToType)) 799 return false; 800 801 // There are no conversions between extended vector types, only identity. 802 if (ToType->isExtVectorType()) { 803 // There are no conversions between extended vector types other than the 804 // identity conversion. 805 if (FromType->isExtVectorType()) 806 return false; 807 808 // Vector splat from any arithmetic type to a vector. 809 if (!FromType->isVectorType() && FromType->isArithmeticType()) { 810 ICK = ICK_Vector_Splat; 811 return true; 812 } 813 } 814 815 // If lax vector conversions are permitted and the vector types are of the 816 // same size, we can perform the conversion. 817 if (Context.getLangOptions().LaxVectorConversions && 818 FromType->isVectorType() && ToType->isVectorType() && 819 Context.getTypeSize(FromType) == Context.getTypeSize(ToType)) { 820 ICK = ICK_Vector_Conversion; 821 return true; 822 } 823 824 return false; 825} 826 827/// IsStandardConversion - Determines whether there is a standard 828/// conversion sequence (C++ [conv], C++ [over.ics.scs]) from the 829/// expression From to the type ToType. Standard conversion sequences 830/// only consider non-class types; for conversions that involve class 831/// types, use TryImplicitConversion. If a conversion exists, SCS will 832/// contain the standard conversion sequence required to perform this 833/// conversion and this routine will return true. Otherwise, this 834/// routine will return false and the value of SCS is unspecified. 835bool 836Sema::IsStandardConversion(Expr* From, QualType ToType, 837 bool InOverloadResolution, 838 StandardConversionSequence &SCS) { 839 QualType FromType = From->getType(); 840 841 // Standard conversions (C++ [conv]) 842 SCS.setAsIdentityConversion(); 843 SCS.DeprecatedStringLiteralToCharPtr = false; 844 SCS.IncompatibleObjC = false; 845 SCS.setFromType(FromType); 846 SCS.CopyConstructor = 0; 847 848 // There are no standard conversions for class types in C++, so 849 // abort early. When overloading in C, however, we do permit 850 if (FromType->isRecordType() || ToType->isRecordType()) { 851 if (getLangOptions().CPlusPlus) 852 return false; 853 854 // When we're overloading in C, we allow, as standard conversions, 855 } 856 857 // The first conversion can be an lvalue-to-rvalue conversion, 858 // array-to-pointer conversion, or function-to-pointer conversion 859 // (C++ 4p1). 860 861 if (FromType == Context.OverloadTy) { 862 DeclAccessPair AccessPair; 863 if (FunctionDecl *Fn 864 = ResolveAddressOfOverloadedFunction(From, ToType, false, 865 AccessPair)) { 866 // We were able to resolve the address of the overloaded function, 867 // so we can convert to the type of that function. 868 FromType = Fn->getType(); 869 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 870 if (!Method->isStatic()) { 871 Type *ClassType 872 = Context.getTypeDeclType(Method->getParent()).getTypePtr(); 873 FromType = Context.getMemberPointerType(FromType, ClassType); 874 } 875 } 876 877 // If the "from" expression takes the address of the overloaded 878 // function, update the type of the resulting expression accordingly. 879 if (FromType->getAs<FunctionType>()) 880 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(From->IgnoreParens())) 881 if (UnOp->getOpcode() == UnaryOperator::AddrOf) 882 FromType = Context.getPointerType(FromType); 883 884 // Check that we've computed the proper type after overload resolution. 885 assert(Context.hasSameType(FromType, 886 FixOverloadedFunctionReference(From, AccessPair, Fn)->getType())); 887 } else { 888 return false; 889 } 890 } 891 // Lvalue-to-rvalue conversion (C++ 4.1): 892 // An lvalue (3.10) of a non-function, non-array type T can be 893 // converted to an rvalue. 894 Expr::isLvalueResult argIsLvalue = From->isLvalue(Context); 895 if (argIsLvalue == Expr::LV_Valid && 896 !FromType->isFunctionType() && !FromType->isArrayType() && 897 Context.getCanonicalType(FromType) != Context.OverloadTy) { 898 SCS.First = ICK_Lvalue_To_Rvalue; 899 900 // If T is a non-class type, the type of the rvalue is the 901 // cv-unqualified version of T. Otherwise, the type of the rvalue 902 // is T (C++ 4.1p1). C++ can't get here with class types; in C, we 903 // just strip the qualifiers because they don't matter. 904 FromType = FromType.getUnqualifiedType(); 905 } else if (FromType->isArrayType()) { 906 // Array-to-pointer conversion (C++ 4.2) 907 SCS.First = ICK_Array_To_Pointer; 908 909 // An lvalue or rvalue of type "array of N T" or "array of unknown 910 // bound of T" can be converted to an rvalue of type "pointer to 911 // T" (C++ 4.2p1). 912 FromType = Context.getArrayDecayedType(FromType); 913 914 if (IsStringLiteralToNonConstPointerConversion(From, ToType)) { 915 // This conversion is deprecated. (C++ D.4). 916 SCS.DeprecatedStringLiteralToCharPtr = true; 917 918 // For the purpose of ranking in overload resolution 919 // (13.3.3.1.1), this conversion is considered an 920 // array-to-pointer conversion followed by a qualification 921 // conversion (4.4). (C++ 4.2p2) 922 SCS.Second = ICK_Identity; 923 SCS.Third = ICK_Qualification; 924 SCS.setAllToTypes(FromType); 925 return true; 926 } 927 } else if (FromType->isFunctionType() && argIsLvalue == Expr::LV_Valid) { 928 // Function-to-pointer conversion (C++ 4.3). 929 SCS.First = ICK_Function_To_Pointer; 930 931 // An lvalue of function type T can be converted to an rvalue of 932 // type "pointer to T." The result is a pointer to the 933 // function. (C++ 4.3p1). 934 FromType = Context.getPointerType(FromType); 935 } else { 936 // We don't require any conversions for the first step. 937 SCS.First = ICK_Identity; 938 } 939 SCS.setToType(0, FromType); 940 941 // The second conversion can be an integral promotion, floating 942 // point promotion, integral conversion, floating point conversion, 943 // floating-integral conversion, pointer conversion, 944 // pointer-to-member conversion, or boolean conversion (C++ 4p1). 945 // For overloading in C, this can also be a "compatible-type" 946 // conversion. 947 bool IncompatibleObjC = false; 948 ImplicitConversionKind SecondICK = ICK_Identity; 949 if (Context.hasSameUnqualifiedType(FromType, ToType)) { 950 // The unqualified versions of the types are the same: there's no 951 // conversion to do. 952 SCS.Second = ICK_Identity; 953 } else if (IsIntegralPromotion(From, FromType, ToType)) { 954 // Integral promotion (C++ 4.5). 955 SCS.Second = ICK_Integral_Promotion; 956 FromType = ToType.getUnqualifiedType(); 957 } else if (IsFloatingPointPromotion(FromType, ToType)) { 958 // Floating point promotion (C++ 4.6). 959 SCS.Second = ICK_Floating_Promotion; 960 FromType = ToType.getUnqualifiedType(); 961 } else if (IsComplexPromotion(FromType, ToType)) { 962 // Complex promotion (Clang extension) 963 SCS.Second = ICK_Complex_Promotion; 964 FromType = ToType.getUnqualifiedType(); 965 } else if (FromType->isIntegralOrEnumerationType() && 966 ToType->isIntegralType(Context)) { 967 // Integral conversions (C++ 4.7). 968 SCS.Second = ICK_Integral_Conversion; 969 FromType = ToType.getUnqualifiedType(); 970 } else if (FromType->isComplexType() && ToType->isComplexType()) { 971 // Complex conversions (C99 6.3.1.6) 972 SCS.Second = ICK_Complex_Conversion; 973 FromType = ToType.getUnqualifiedType(); 974 } else if ((FromType->isComplexType() && ToType->isArithmeticType()) || 975 (ToType->isComplexType() && FromType->isArithmeticType())) { 976 // Complex-real conversions (C99 6.3.1.7) 977 SCS.Second = ICK_Complex_Real; 978 FromType = ToType.getUnqualifiedType(); 979 } else if (FromType->isFloatingType() && ToType->isFloatingType()) { 980 // Floating point conversions (C++ 4.8). 981 SCS.Second = ICK_Floating_Conversion; 982 FromType = ToType.getUnqualifiedType(); 983 } else if ((FromType->isFloatingType() && 984 ToType->isIntegralType(Context) && !ToType->isBooleanType()) || 985 (FromType->isIntegralOrEnumerationType() && 986 ToType->isFloatingType())) { 987 // Floating-integral conversions (C++ 4.9). 988 SCS.Second = ICK_Floating_Integral; 989 FromType = ToType.getUnqualifiedType(); 990 } else if (IsPointerConversion(From, FromType, ToType, InOverloadResolution, 991 FromType, IncompatibleObjC)) { 992 // Pointer conversions (C++ 4.10). 993 SCS.Second = ICK_Pointer_Conversion; 994 SCS.IncompatibleObjC = IncompatibleObjC; 995 } else if (IsMemberPointerConversion(From, FromType, ToType, 996 InOverloadResolution, FromType)) { 997 // Pointer to member conversions (4.11). 998 SCS.Second = ICK_Pointer_Member; 999 } else if (ToType->isBooleanType() && 1000 (FromType->isArithmeticType() || 1001 FromType->isEnumeralType() || 1002 FromType->isAnyPointerType() || 1003 FromType->isBlockPointerType() || 1004 FromType->isMemberPointerType() || 1005 FromType->isNullPtrType())) { 1006 // Boolean conversions (C++ 4.12). 1007 SCS.Second = ICK_Boolean_Conversion; 1008 FromType = Context.BoolTy; 1009 } else if (IsVectorConversion(Context, FromType, ToType, SecondICK)) { 1010 SCS.Second = SecondICK; 1011 FromType = ToType.getUnqualifiedType(); 1012 } else if (!getLangOptions().CPlusPlus && 1013 Context.typesAreCompatible(ToType, FromType)) { 1014 // Compatible conversions (Clang extension for C function overloading) 1015 SCS.Second = ICK_Compatible_Conversion; 1016 FromType = ToType.getUnqualifiedType(); 1017 } else if (IsNoReturnConversion(Context, FromType, ToType, FromType)) { 1018 // Treat a conversion that strips "noreturn" as an identity conversion. 1019 SCS.Second = ICK_NoReturn_Adjustment; 1020 } else { 1021 // No second conversion required. 1022 SCS.Second = ICK_Identity; 1023 } 1024 SCS.setToType(1, FromType); 1025 1026 QualType CanonFrom; 1027 QualType CanonTo; 1028 // The third conversion can be a qualification conversion (C++ 4p1). 1029 if (IsQualificationConversion(FromType, ToType)) { 1030 SCS.Third = ICK_Qualification; 1031 FromType = ToType; 1032 CanonFrom = Context.getCanonicalType(FromType); 1033 CanonTo = Context.getCanonicalType(ToType); 1034 } else { 1035 // No conversion required 1036 SCS.Third = ICK_Identity; 1037 1038 // C++ [over.best.ics]p6: 1039 // [...] Any difference in top-level cv-qualification is 1040 // subsumed by the initialization itself and does not constitute 1041 // a conversion. [...] 1042 CanonFrom = Context.getCanonicalType(FromType); 1043 CanonTo = Context.getCanonicalType(ToType); 1044 if (CanonFrom.getLocalUnqualifiedType() 1045 == CanonTo.getLocalUnqualifiedType() && 1046 (CanonFrom.getLocalCVRQualifiers() != CanonTo.getLocalCVRQualifiers() 1047 || CanonFrom.getObjCGCAttr() != CanonTo.getObjCGCAttr())) { 1048 FromType = ToType; 1049 CanonFrom = CanonTo; 1050 } 1051 } 1052 SCS.setToType(2, FromType); 1053 1054 // If we have not converted the argument type to the parameter type, 1055 // this is a bad conversion sequence. 1056 if (CanonFrom != CanonTo) 1057 return false; 1058 1059 return true; 1060} 1061 1062/// IsIntegralPromotion - Determines whether the conversion from the 1063/// expression From (whose potentially-adjusted type is FromType) to 1064/// ToType is an integral promotion (C++ 4.5). If so, returns true and 1065/// sets PromotedType to the promoted type. 1066bool Sema::IsIntegralPromotion(Expr *From, QualType FromType, QualType ToType) { 1067 const BuiltinType *To = ToType->getAs<BuiltinType>(); 1068 // All integers are built-in. 1069 if (!To) { 1070 return false; 1071 } 1072 1073 // An rvalue of type char, signed char, unsigned char, short int, or 1074 // unsigned short int can be converted to an rvalue of type int if 1075 // int can represent all the values of the source type; otherwise, 1076 // the source rvalue can be converted to an rvalue of type unsigned 1077 // int (C++ 4.5p1). 1078 if (FromType->isPromotableIntegerType() && !FromType->isBooleanType() && 1079 !FromType->isEnumeralType()) { 1080 if (// We can promote any signed, promotable integer type to an int 1081 (FromType->isSignedIntegerType() || 1082 // We can promote any unsigned integer type whose size is 1083 // less than int to an int. 1084 (!FromType->isSignedIntegerType() && 1085 Context.getTypeSize(FromType) < Context.getTypeSize(ToType)))) { 1086 return To->getKind() == BuiltinType::Int; 1087 } 1088 1089 return To->getKind() == BuiltinType::UInt; 1090 } 1091 1092 // An rvalue of type wchar_t (3.9.1) or an enumeration type (7.2) 1093 // can be converted to an rvalue of the first of the following types 1094 // that can represent all the values of its underlying type: int, 1095 // unsigned int, long, or unsigned long (C++ 4.5p2). 1096 1097 // We pre-calculate the promotion type for enum types. 1098 if (const EnumType *FromEnumType = FromType->getAs<EnumType>()) 1099 if (ToType->isIntegerType()) 1100 return Context.hasSameUnqualifiedType(ToType, 1101 FromEnumType->getDecl()->getPromotionType()); 1102 1103 if (FromType->isWideCharType() && ToType->isIntegerType()) { 1104 // Determine whether the type we're converting from is signed or 1105 // unsigned. 1106 bool FromIsSigned; 1107 uint64_t FromSize = Context.getTypeSize(FromType); 1108 1109 // FIXME: Is wchar_t signed or unsigned? We assume it's signed for now. 1110 FromIsSigned = true; 1111 1112 // The types we'll try to promote to, in the appropriate 1113 // order. Try each of these types. 1114 QualType PromoteTypes[6] = { 1115 Context.IntTy, Context.UnsignedIntTy, 1116 Context.LongTy, Context.UnsignedLongTy , 1117 Context.LongLongTy, Context.UnsignedLongLongTy 1118 }; 1119 for (int Idx = 0; Idx < 6; ++Idx) { 1120 uint64_t ToSize = Context.getTypeSize(PromoteTypes[Idx]); 1121 if (FromSize < ToSize || 1122 (FromSize == ToSize && 1123 FromIsSigned == PromoteTypes[Idx]->isSignedIntegerType())) { 1124 // We found the type that we can promote to. If this is the 1125 // type we wanted, we have a promotion. Otherwise, no 1126 // promotion. 1127 return Context.hasSameUnqualifiedType(ToType, PromoteTypes[Idx]); 1128 } 1129 } 1130 } 1131 1132 // An rvalue for an integral bit-field (9.6) can be converted to an 1133 // rvalue of type int if int can represent all the values of the 1134 // bit-field; otherwise, it can be converted to unsigned int if 1135 // unsigned int can represent all the values of the bit-field. If 1136 // the bit-field is larger yet, no integral promotion applies to 1137 // it. If the bit-field has an enumerated type, it is treated as any 1138 // other value of that type for promotion purposes (C++ 4.5p3). 1139 // FIXME: We should delay checking of bit-fields until we actually perform the 1140 // conversion. 1141 using llvm::APSInt; 1142 if (From) 1143 if (FieldDecl *MemberDecl = From->getBitField()) { 1144 APSInt BitWidth; 1145 if (FromType->isIntegralType(Context) && 1146 MemberDecl->getBitWidth()->isIntegerConstantExpr(BitWidth, Context)) { 1147 APSInt ToSize(BitWidth.getBitWidth(), BitWidth.isUnsigned()); 1148 ToSize = Context.getTypeSize(ToType); 1149 1150 // Are we promoting to an int from a bitfield that fits in an int? 1151 if (BitWidth < ToSize || 1152 (FromType->isSignedIntegerType() && BitWidth <= ToSize)) { 1153 return To->getKind() == BuiltinType::Int; 1154 } 1155 1156 // Are we promoting to an unsigned int from an unsigned bitfield 1157 // that fits into an unsigned int? 1158 if (FromType->isUnsignedIntegerType() && BitWidth <= ToSize) { 1159 return To->getKind() == BuiltinType::UInt; 1160 } 1161 1162 return false; 1163 } 1164 } 1165 1166 // An rvalue of type bool can be converted to an rvalue of type int, 1167 // with false becoming zero and true becoming one (C++ 4.5p4). 1168 if (FromType->isBooleanType() && To->getKind() == BuiltinType::Int) { 1169 return true; 1170 } 1171 1172 return false; 1173} 1174 1175/// IsFloatingPointPromotion - Determines whether the conversion from 1176/// FromType to ToType is a floating point promotion (C++ 4.6). If so, 1177/// returns true and sets PromotedType to the promoted type. 1178bool Sema::IsFloatingPointPromotion(QualType FromType, QualType ToType) { 1179 /// An rvalue of type float can be converted to an rvalue of type 1180 /// double. (C++ 4.6p1). 1181 if (const BuiltinType *FromBuiltin = FromType->getAs<BuiltinType>()) 1182 if (const BuiltinType *ToBuiltin = ToType->getAs<BuiltinType>()) { 1183 if (FromBuiltin->getKind() == BuiltinType::Float && 1184 ToBuiltin->getKind() == BuiltinType::Double) 1185 return true; 1186 1187 // C99 6.3.1.5p1: 1188 // When a float is promoted to double or long double, or a 1189 // double is promoted to long double [...]. 1190 if (!getLangOptions().CPlusPlus && 1191 (FromBuiltin->getKind() == BuiltinType::Float || 1192 FromBuiltin->getKind() == BuiltinType::Double) && 1193 (ToBuiltin->getKind() == BuiltinType::LongDouble)) 1194 return true; 1195 } 1196 1197 return false; 1198} 1199 1200/// \brief Determine if a conversion is a complex promotion. 1201/// 1202/// A complex promotion is defined as a complex -> complex conversion 1203/// where the conversion between the underlying real types is a 1204/// floating-point or integral promotion. 1205bool Sema::IsComplexPromotion(QualType FromType, QualType ToType) { 1206 const ComplexType *FromComplex = FromType->getAs<ComplexType>(); 1207 if (!FromComplex) 1208 return false; 1209 1210 const ComplexType *ToComplex = ToType->getAs<ComplexType>(); 1211 if (!ToComplex) 1212 return false; 1213 1214 return IsFloatingPointPromotion(FromComplex->getElementType(), 1215 ToComplex->getElementType()) || 1216 IsIntegralPromotion(0, FromComplex->getElementType(), 1217 ToComplex->getElementType()); 1218} 1219 1220/// BuildSimilarlyQualifiedPointerType - In a pointer conversion from 1221/// the pointer type FromPtr to a pointer to type ToPointee, with the 1222/// same type qualifiers as FromPtr has on its pointee type. ToType, 1223/// if non-empty, will be a pointer to ToType that may or may not have 1224/// the right set of qualifiers on its pointee. 1225static QualType 1226BuildSimilarlyQualifiedPointerType(const PointerType *FromPtr, 1227 QualType ToPointee, QualType ToType, 1228 ASTContext &Context) { 1229 QualType CanonFromPointee = Context.getCanonicalType(FromPtr->getPointeeType()); 1230 QualType CanonToPointee = Context.getCanonicalType(ToPointee); 1231 Qualifiers Quals = CanonFromPointee.getQualifiers(); 1232 1233 // Exact qualifier match -> return the pointer type we're converting to. 1234 if (CanonToPointee.getLocalQualifiers() == Quals) { 1235 // ToType is exactly what we need. Return it. 1236 if (!ToType.isNull()) 1237 return ToType.getUnqualifiedType(); 1238 1239 // Build a pointer to ToPointee. It has the right qualifiers 1240 // already. 1241 return Context.getPointerType(ToPointee); 1242 } 1243 1244 // Just build a canonical type that has the right qualifiers. 1245 return Context.getPointerType( 1246 Context.getQualifiedType(CanonToPointee.getLocalUnqualifiedType(), 1247 Quals)); 1248} 1249 1250/// BuildSimilarlyQualifiedObjCObjectPointerType - In a pointer conversion from 1251/// the FromType, which is an objective-c pointer, to ToType, which may or may 1252/// not have the right set of qualifiers. 1253static QualType 1254BuildSimilarlyQualifiedObjCObjectPointerType(QualType FromType, 1255 QualType ToType, 1256 ASTContext &Context) { 1257 QualType CanonFromType = Context.getCanonicalType(FromType); 1258 QualType CanonToType = Context.getCanonicalType(ToType); 1259 Qualifiers Quals = CanonFromType.getQualifiers(); 1260 1261 // Exact qualifier match -> return the pointer type we're converting to. 1262 if (CanonToType.getLocalQualifiers() == Quals) 1263 return ToType; 1264 1265 // Just build a canonical type that has the right qualifiers. 1266 return Context.getQualifiedType(CanonToType.getLocalUnqualifiedType(), Quals); 1267} 1268 1269static bool isNullPointerConstantForConversion(Expr *Expr, 1270 bool InOverloadResolution, 1271 ASTContext &Context) { 1272 // Handle value-dependent integral null pointer constants correctly. 1273 // http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#903 1274 if (Expr->isValueDependent() && !Expr->isTypeDependent() && 1275 Expr->getType()->isIntegerType() && !Expr->getType()->isEnumeralType()) 1276 return !InOverloadResolution; 1277 1278 return Expr->isNullPointerConstant(Context, 1279 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull 1280 : Expr::NPC_ValueDependentIsNull); 1281} 1282 1283/// IsPointerConversion - Determines whether the conversion of the 1284/// expression From, which has the (possibly adjusted) type FromType, 1285/// can be converted to the type ToType via a pointer conversion (C++ 1286/// 4.10). If so, returns true and places the converted type (that 1287/// might differ from ToType in its cv-qualifiers at some level) into 1288/// ConvertedType. 1289/// 1290/// This routine also supports conversions to and from block pointers 1291/// and conversions with Objective-C's 'id', 'id<protocols...>', and 1292/// pointers to interfaces. FIXME: Once we've determined the 1293/// appropriate overloading rules for Objective-C, we may want to 1294/// split the Objective-C checks into a different routine; however, 1295/// GCC seems to consider all of these conversions to be pointer 1296/// conversions, so for now they live here. IncompatibleObjC will be 1297/// set if the conversion is an allowed Objective-C conversion that 1298/// should result in a warning. 1299bool Sema::IsPointerConversion(Expr *From, QualType FromType, QualType ToType, 1300 bool InOverloadResolution, 1301 QualType& ConvertedType, 1302 bool &IncompatibleObjC) { 1303 IncompatibleObjC = false; 1304 if (isObjCPointerConversion(FromType, ToType, ConvertedType, IncompatibleObjC)) 1305 return true; 1306 1307 // Conversion from a null pointer constant to any Objective-C pointer type. 1308 if (ToType->isObjCObjectPointerType() && 1309 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1310 ConvertedType = ToType; 1311 return true; 1312 } 1313 1314 // Blocks: Block pointers can be converted to void*. 1315 if (FromType->isBlockPointerType() && ToType->isPointerType() && 1316 ToType->getAs<PointerType>()->getPointeeType()->isVoidType()) { 1317 ConvertedType = ToType; 1318 return true; 1319 } 1320 // Blocks: A null pointer constant can be converted to a block 1321 // pointer type. 1322 if (ToType->isBlockPointerType() && 1323 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1324 ConvertedType = ToType; 1325 return true; 1326 } 1327 1328 // If the left-hand-side is nullptr_t, the right side can be a null 1329 // pointer constant. 1330 if (ToType->isNullPtrType() && 1331 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1332 ConvertedType = ToType; 1333 return true; 1334 } 1335 1336 const PointerType* ToTypePtr = ToType->getAs<PointerType>(); 1337 if (!ToTypePtr) 1338 return false; 1339 1340 // A null pointer constant can be converted to a pointer type (C++ 4.10p1). 1341 if (isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1342 ConvertedType = ToType; 1343 return true; 1344 } 1345 1346 // Beyond this point, both types need to be pointers 1347 // , including objective-c pointers. 1348 QualType ToPointeeType = ToTypePtr->getPointeeType(); 1349 if (FromType->isObjCObjectPointerType() && ToPointeeType->isVoidType()) { 1350 ConvertedType = BuildSimilarlyQualifiedObjCObjectPointerType(FromType, 1351 ToType, Context); 1352 return true; 1353 1354 } 1355 const PointerType *FromTypePtr = FromType->getAs<PointerType>(); 1356 if (!FromTypePtr) 1357 return false; 1358 1359 QualType FromPointeeType = FromTypePtr->getPointeeType(); 1360 1361 // An rvalue of type "pointer to cv T," where T is an object type, 1362 // can be converted to an rvalue of type "pointer to cv void" (C++ 1363 // 4.10p2). 1364 if (FromPointeeType->isObjectType() && ToPointeeType->isVoidType()) { 1365 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1366 ToPointeeType, 1367 ToType, Context); 1368 return true; 1369 } 1370 1371 // When we're overloading in C, we allow a special kind of pointer 1372 // conversion for compatible-but-not-identical pointee types. 1373 if (!getLangOptions().CPlusPlus && 1374 Context.typesAreCompatible(FromPointeeType, ToPointeeType)) { 1375 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1376 ToPointeeType, 1377 ToType, Context); 1378 return true; 1379 } 1380 1381 // C++ [conv.ptr]p3: 1382 // 1383 // An rvalue of type "pointer to cv D," where D is a class type, 1384 // can be converted to an rvalue of type "pointer to cv B," where 1385 // B is a base class (clause 10) of D. If B is an inaccessible 1386 // (clause 11) or ambiguous (10.2) base class of D, a program that 1387 // necessitates this conversion is ill-formed. The result of the 1388 // conversion is a pointer to the base class sub-object of the 1389 // derived class object. The null pointer value is converted to 1390 // the null pointer value of the destination type. 1391 // 1392 // Note that we do not check for ambiguity or inaccessibility 1393 // here. That is handled by CheckPointerConversion. 1394 if (getLangOptions().CPlusPlus && 1395 FromPointeeType->isRecordType() && ToPointeeType->isRecordType() && 1396 !Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType) && 1397 !RequireCompleteType(From->getLocStart(), FromPointeeType, PDiag()) && 1398 IsDerivedFrom(FromPointeeType, ToPointeeType)) { 1399 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1400 ToPointeeType, 1401 ToType, Context); 1402 return true; 1403 } 1404 1405 return false; 1406} 1407 1408/// isObjCPointerConversion - Determines whether this is an 1409/// Objective-C pointer conversion. Subroutine of IsPointerConversion, 1410/// with the same arguments and return values. 1411bool Sema::isObjCPointerConversion(QualType FromType, QualType ToType, 1412 QualType& ConvertedType, 1413 bool &IncompatibleObjC) { 1414 if (!getLangOptions().ObjC1) 1415 return false; 1416 1417 // First, we handle all conversions on ObjC object pointer types. 1418 const ObjCObjectPointerType* ToObjCPtr = ToType->getAs<ObjCObjectPointerType>(); 1419 const ObjCObjectPointerType *FromObjCPtr = 1420 FromType->getAs<ObjCObjectPointerType>(); 1421 1422 if (ToObjCPtr && FromObjCPtr) { 1423 // Objective C++: We're able to convert between "id" or "Class" and a 1424 // pointer to any interface (in both directions). 1425 if (ToObjCPtr->isObjCBuiltinType() && FromObjCPtr->isObjCBuiltinType()) { 1426 ConvertedType = ToType; 1427 return true; 1428 } 1429 // Conversions with Objective-C's id<...>. 1430 if ((FromObjCPtr->isObjCQualifiedIdType() || 1431 ToObjCPtr->isObjCQualifiedIdType()) && 1432 Context.ObjCQualifiedIdTypesAreCompatible(ToType, FromType, 1433 /*compare=*/false)) { 1434 ConvertedType = ToType; 1435 return true; 1436 } 1437 // Objective C++: We're able to convert from a pointer to an 1438 // interface to a pointer to a different interface. 1439 if (Context.canAssignObjCInterfaces(ToObjCPtr, FromObjCPtr)) { 1440 const ObjCInterfaceType* LHS = ToObjCPtr->getInterfaceType(); 1441 const ObjCInterfaceType* RHS = FromObjCPtr->getInterfaceType(); 1442 if (getLangOptions().CPlusPlus && LHS && RHS && 1443 !ToObjCPtr->getPointeeType().isAtLeastAsQualifiedAs( 1444 FromObjCPtr->getPointeeType())) 1445 return false; 1446 ConvertedType = ToType; 1447 return true; 1448 } 1449 1450 if (Context.canAssignObjCInterfaces(FromObjCPtr, ToObjCPtr)) { 1451 // Okay: this is some kind of implicit downcast of Objective-C 1452 // interfaces, which is permitted. However, we're going to 1453 // complain about it. 1454 IncompatibleObjC = true; 1455 ConvertedType = FromType; 1456 return true; 1457 } 1458 } 1459 // Beyond this point, both types need to be C pointers or block pointers. 1460 QualType ToPointeeType; 1461 if (const PointerType *ToCPtr = ToType->getAs<PointerType>()) 1462 ToPointeeType = ToCPtr->getPointeeType(); 1463 else if (const BlockPointerType *ToBlockPtr = 1464 ToType->getAs<BlockPointerType>()) { 1465 // Objective C++: We're able to convert from a pointer to any object 1466 // to a block pointer type. 1467 if (FromObjCPtr && FromObjCPtr->isObjCBuiltinType()) { 1468 ConvertedType = ToType; 1469 return true; 1470 } 1471 ToPointeeType = ToBlockPtr->getPointeeType(); 1472 } 1473 else if (FromType->getAs<BlockPointerType>() && 1474 ToObjCPtr && ToObjCPtr->isObjCBuiltinType()) { 1475 // Objective C++: We're able to convert from a block pointer type to a 1476 // pointer to any object. 1477 ConvertedType = ToType; 1478 return true; 1479 } 1480 else 1481 return false; 1482 1483 QualType FromPointeeType; 1484 if (const PointerType *FromCPtr = FromType->getAs<PointerType>()) 1485 FromPointeeType = FromCPtr->getPointeeType(); 1486 else if (const BlockPointerType *FromBlockPtr = FromType->getAs<BlockPointerType>()) 1487 FromPointeeType = FromBlockPtr->getPointeeType(); 1488 else 1489 return false; 1490 1491 // If we have pointers to pointers, recursively check whether this 1492 // is an Objective-C conversion. 1493 if (FromPointeeType->isPointerType() && ToPointeeType->isPointerType() && 1494 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, 1495 IncompatibleObjC)) { 1496 // We always complain about this conversion. 1497 IncompatibleObjC = true; 1498 ConvertedType = ToType; 1499 return true; 1500 } 1501 // Allow conversion of pointee being objective-c pointer to another one; 1502 // as in I* to id. 1503 if (FromPointeeType->getAs<ObjCObjectPointerType>() && 1504 ToPointeeType->getAs<ObjCObjectPointerType>() && 1505 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, 1506 IncompatibleObjC)) { 1507 ConvertedType = ToType; 1508 return true; 1509 } 1510 1511 // If we have pointers to functions or blocks, check whether the only 1512 // differences in the argument and result types are in Objective-C 1513 // pointer conversions. If so, we permit the conversion (but 1514 // complain about it). 1515 const FunctionProtoType *FromFunctionType 1516 = FromPointeeType->getAs<FunctionProtoType>(); 1517 const FunctionProtoType *ToFunctionType 1518 = ToPointeeType->getAs<FunctionProtoType>(); 1519 if (FromFunctionType && ToFunctionType) { 1520 // If the function types are exactly the same, this isn't an 1521 // Objective-C pointer conversion. 1522 if (Context.getCanonicalType(FromPointeeType) 1523 == Context.getCanonicalType(ToPointeeType)) 1524 return false; 1525 1526 // Perform the quick checks that will tell us whether these 1527 // function types are obviously different. 1528 if (FromFunctionType->getNumArgs() != ToFunctionType->getNumArgs() || 1529 FromFunctionType->isVariadic() != ToFunctionType->isVariadic() || 1530 FromFunctionType->getTypeQuals() != ToFunctionType->getTypeQuals()) 1531 return false; 1532 1533 bool HasObjCConversion = false; 1534 if (Context.getCanonicalType(FromFunctionType->getResultType()) 1535 == Context.getCanonicalType(ToFunctionType->getResultType())) { 1536 // Okay, the types match exactly. Nothing to do. 1537 } else if (isObjCPointerConversion(FromFunctionType->getResultType(), 1538 ToFunctionType->getResultType(), 1539 ConvertedType, IncompatibleObjC)) { 1540 // Okay, we have an Objective-C pointer conversion. 1541 HasObjCConversion = true; 1542 } else { 1543 // Function types are too different. Abort. 1544 return false; 1545 } 1546 1547 // Check argument types. 1548 for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumArgs(); 1549 ArgIdx != NumArgs; ++ArgIdx) { 1550 QualType FromArgType = FromFunctionType->getArgType(ArgIdx); 1551 QualType ToArgType = ToFunctionType->getArgType(ArgIdx); 1552 if (Context.getCanonicalType(FromArgType) 1553 == Context.getCanonicalType(ToArgType)) { 1554 // Okay, the types match exactly. Nothing to do. 1555 } else if (isObjCPointerConversion(FromArgType, ToArgType, 1556 ConvertedType, IncompatibleObjC)) { 1557 // Okay, we have an Objective-C pointer conversion. 1558 HasObjCConversion = true; 1559 } else { 1560 // Argument types are too different. Abort. 1561 return false; 1562 } 1563 } 1564 1565 if (HasObjCConversion) { 1566 // We had an Objective-C conversion. Allow this pointer 1567 // conversion, but complain about it. 1568 ConvertedType = ToType; 1569 IncompatibleObjC = true; 1570 return true; 1571 } 1572 } 1573 1574 return false; 1575} 1576 1577/// FunctionArgTypesAreEqual - This routine checks two function proto types 1578/// for equlity of their argument types. Caller has already checked that 1579/// they have same number of arguments. This routine assumes that Objective-C 1580/// pointer types which only differ in their protocol qualifiers are equal. 1581bool Sema::FunctionArgTypesAreEqual(FunctionProtoType* OldType, 1582 FunctionProtoType* NewType){ 1583 if (!getLangOptions().ObjC1) 1584 return std::equal(OldType->arg_type_begin(), OldType->arg_type_end(), 1585 NewType->arg_type_begin()); 1586 1587 for (FunctionProtoType::arg_type_iterator O = OldType->arg_type_begin(), 1588 N = NewType->arg_type_begin(), 1589 E = OldType->arg_type_end(); O && (O != E); ++O, ++N) { 1590 QualType ToType = (*O); 1591 QualType FromType = (*N); 1592 if (ToType != FromType) { 1593 if (const PointerType *PTTo = ToType->getAs<PointerType>()) { 1594 if (const PointerType *PTFr = FromType->getAs<PointerType>()) 1595 if ((PTTo->getPointeeType()->isObjCQualifiedIdType() && 1596 PTFr->getPointeeType()->isObjCQualifiedIdType()) || 1597 (PTTo->getPointeeType()->isObjCQualifiedClassType() && 1598 PTFr->getPointeeType()->isObjCQualifiedClassType())) 1599 continue; 1600 } 1601 else if (const ObjCObjectPointerType *PTTo = 1602 ToType->getAs<ObjCObjectPointerType>()) { 1603 if (const ObjCObjectPointerType *PTFr = 1604 FromType->getAs<ObjCObjectPointerType>()) 1605 if (PTTo->getInterfaceDecl() == PTFr->getInterfaceDecl()) 1606 continue; 1607 } 1608 return false; 1609 } 1610 } 1611 return true; 1612} 1613 1614/// CheckPointerConversion - Check the pointer conversion from the 1615/// expression From to the type ToType. This routine checks for 1616/// ambiguous or inaccessible derived-to-base pointer 1617/// conversions for which IsPointerConversion has already returned 1618/// true. It returns true and produces a diagnostic if there was an 1619/// error, or returns false otherwise. 1620bool Sema::CheckPointerConversion(Expr *From, QualType ToType, 1621 CastExpr::CastKind &Kind, 1622 CXXBaseSpecifierArray& BasePath, 1623 bool IgnoreBaseAccess) { 1624 QualType FromType = From->getType(); 1625 1626 if (CXXBoolLiteralExpr* LitBool 1627 = dyn_cast<CXXBoolLiteralExpr>(From->IgnoreParens())) 1628 if (LitBool->getValue() == false) 1629 Diag(LitBool->getExprLoc(), diag::warn_init_pointer_from_false) 1630 << ToType; 1631 1632 if (const PointerType *FromPtrType = FromType->getAs<PointerType>()) 1633 if (const PointerType *ToPtrType = ToType->getAs<PointerType>()) { 1634 QualType FromPointeeType = FromPtrType->getPointeeType(), 1635 ToPointeeType = ToPtrType->getPointeeType(); 1636 1637 if (FromPointeeType->isRecordType() && ToPointeeType->isRecordType() && 1638 !Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType)) { 1639 // We must have a derived-to-base conversion. Check an 1640 // ambiguous or inaccessible conversion. 1641 if (CheckDerivedToBaseConversion(FromPointeeType, ToPointeeType, 1642 From->getExprLoc(), 1643 From->getSourceRange(), &BasePath, 1644 IgnoreBaseAccess)) 1645 return true; 1646 1647 // The conversion was successful. 1648 Kind = CastExpr::CK_DerivedToBase; 1649 } 1650 } 1651 if (const ObjCObjectPointerType *FromPtrType = 1652 FromType->getAs<ObjCObjectPointerType>()) 1653 if (const ObjCObjectPointerType *ToPtrType = 1654 ToType->getAs<ObjCObjectPointerType>()) { 1655 // Objective-C++ conversions are always okay. 1656 // FIXME: We should have a different class of conversions for the 1657 // Objective-C++ implicit conversions. 1658 if (FromPtrType->isObjCBuiltinType() || ToPtrType->isObjCBuiltinType()) 1659 return false; 1660 1661 } 1662 return false; 1663} 1664 1665/// IsMemberPointerConversion - Determines whether the conversion of the 1666/// expression From, which has the (possibly adjusted) type FromType, can be 1667/// converted to the type ToType via a member pointer conversion (C++ 4.11). 1668/// If so, returns true and places the converted type (that might differ from 1669/// ToType in its cv-qualifiers at some level) into ConvertedType. 1670bool Sema::IsMemberPointerConversion(Expr *From, QualType FromType, 1671 QualType ToType, 1672 bool InOverloadResolution, 1673 QualType &ConvertedType) { 1674 const MemberPointerType *ToTypePtr = ToType->getAs<MemberPointerType>(); 1675 if (!ToTypePtr) 1676 return false; 1677 1678 // A null pointer constant can be converted to a member pointer (C++ 4.11p1) 1679 if (From->isNullPointerConstant(Context, 1680 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull 1681 : Expr::NPC_ValueDependentIsNull)) { 1682 ConvertedType = ToType; 1683 return true; 1684 } 1685 1686 // Otherwise, both types have to be member pointers. 1687 const MemberPointerType *FromTypePtr = FromType->getAs<MemberPointerType>(); 1688 if (!FromTypePtr) 1689 return false; 1690 1691 // A pointer to member of B can be converted to a pointer to member of D, 1692 // where D is derived from B (C++ 4.11p2). 1693 QualType FromClass(FromTypePtr->getClass(), 0); 1694 QualType ToClass(ToTypePtr->getClass(), 0); 1695 // FIXME: What happens when these are dependent? Is this function even called? 1696 1697 if (IsDerivedFrom(ToClass, FromClass)) { 1698 ConvertedType = Context.getMemberPointerType(FromTypePtr->getPointeeType(), 1699 ToClass.getTypePtr()); 1700 return true; 1701 } 1702 1703 return false; 1704} 1705 1706/// CheckMemberPointerConversion - Check the member pointer conversion from the 1707/// expression From to the type ToType. This routine checks for ambiguous or 1708/// virtual or inaccessible base-to-derived member pointer conversions 1709/// for which IsMemberPointerConversion has already returned true. It returns 1710/// true and produces a diagnostic if there was an error, or returns false 1711/// otherwise. 1712bool Sema::CheckMemberPointerConversion(Expr *From, QualType ToType, 1713 CastExpr::CastKind &Kind, 1714 CXXBaseSpecifierArray &BasePath, 1715 bool IgnoreBaseAccess) { 1716 QualType FromType = From->getType(); 1717 const MemberPointerType *FromPtrType = FromType->getAs<MemberPointerType>(); 1718 if (!FromPtrType) { 1719 // This must be a null pointer to member pointer conversion 1720 assert(From->isNullPointerConstant(Context, 1721 Expr::NPC_ValueDependentIsNull) && 1722 "Expr must be null pointer constant!"); 1723 Kind = CastExpr::CK_NullToMemberPointer; 1724 return false; 1725 } 1726 1727 const MemberPointerType *ToPtrType = ToType->getAs<MemberPointerType>(); 1728 assert(ToPtrType && "No member pointer cast has a target type " 1729 "that is not a member pointer."); 1730 1731 QualType FromClass = QualType(FromPtrType->getClass(), 0); 1732 QualType ToClass = QualType(ToPtrType->getClass(), 0); 1733 1734 // FIXME: What about dependent types? 1735 assert(FromClass->isRecordType() && "Pointer into non-class."); 1736 assert(ToClass->isRecordType() && "Pointer into non-class."); 1737 1738 CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true, 1739 /*DetectVirtual=*/true); 1740 bool DerivationOkay = IsDerivedFrom(ToClass, FromClass, Paths); 1741 assert(DerivationOkay && 1742 "Should not have been called if derivation isn't OK."); 1743 (void)DerivationOkay; 1744 1745 if (Paths.isAmbiguous(Context.getCanonicalType(FromClass). 1746 getUnqualifiedType())) { 1747 std::string PathDisplayStr = getAmbiguousPathsDisplayString(Paths); 1748 Diag(From->getExprLoc(), diag::err_ambiguous_memptr_conv) 1749 << 0 << FromClass << ToClass << PathDisplayStr << From->getSourceRange(); 1750 return true; 1751 } 1752 1753 if (const RecordType *VBase = Paths.getDetectedVirtual()) { 1754 Diag(From->getExprLoc(), diag::err_memptr_conv_via_virtual) 1755 << FromClass << ToClass << QualType(VBase, 0) 1756 << From->getSourceRange(); 1757 return true; 1758 } 1759 1760 if (!IgnoreBaseAccess) 1761 CheckBaseClassAccess(From->getExprLoc(), FromClass, ToClass, 1762 Paths.front(), 1763 diag::err_downcast_from_inaccessible_base); 1764 1765 // Must be a base to derived member conversion. 1766 BuildBasePathArray(Paths, BasePath); 1767 Kind = CastExpr::CK_BaseToDerivedMemberPointer; 1768 return false; 1769} 1770 1771/// IsQualificationConversion - Determines whether the conversion from 1772/// an rvalue of type FromType to ToType is a qualification conversion 1773/// (C++ 4.4). 1774bool 1775Sema::IsQualificationConversion(QualType FromType, QualType ToType) { 1776 FromType = Context.getCanonicalType(FromType); 1777 ToType = Context.getCanonicalType(ToType); 1778 1779 // If FromType and ToType are the same type, this is not a 1780 // qualification conversion. 1781 if (FromType.getUnqualifiedType() == ToType.getUnqualifiedType()) 1782 return false; 1783 1784 // (C++ 4.4p4): 1785 // A conversion can add cv-qualifiers at levels other than the first 1786 // in multi-level pointers, subject to the following rules: [...] 1787 bool PreviousToQualsIncludeConst = true; 1788 bool UnwrappedAnyPointer = false; 1789 while (Context.UnwrapSimilarPointerTypes(FromType, ToType)) { 1790 // Within each iteration of the loop, we check the qualifiers to 1791 // determine if this still looks like a qualification 1792 // conversion. Then, if all is well, we unwrap one more level of 1793 // pointers or pointers-to-members and do it all again 1794 // until there are no more pointers or pointers-to-members left to 1795 // unwrap. 1796 UnwrappedAnyPointer = true; 1797 1798 // -- for every j > 0, if const is in cv 1,j then const is in cv 1799 // 2,j, and similarly for volatile. 1800 if (!ToType.isAtLeastAsQualifiedAs(FromType)) 1801 return false; 1802 1803 // -- if the cv 1,j and cv 2,j are different, then const is in 1804 // every cv for 0 < k < j. 1805 if (FromType.getCVRQualifiers() != ToType.getCVRQualifiers() 1806 && !PreviousToQualsIncludeConst) 1807 return false; 1808 1809 // Keep track of whether all prior cv-qualifiers in the "to" type 1810 // include const. 1811 PreviousToQualsIncludeConst 1812 = PreviousToQualsIncludeConst && ToType.isConstQualified(); 1813 } 1814 1815 // We are left with FromType and ToType being the pointee types 1816 // after unwrapping the original FromType and ToType the same number 1817 // of types. If we unwrapped any pointers, and if FromType and 1818 // ToType have the same unqualified type (since we checked 1819 // qualifiers above), then this is a qualification conversion. 1820 return UnwrappedAnyPointer && Context.hasSameUnqualifiedType(FromType,ToType); 1821} 1822 1823/// Determines whether there is a user-defined conversion sequence 1824/// (C++ [over.ics.user]) that converts expression From to the type 1825/// ToType. If such a conversion exists, User will contain the 1826/// user-defined conversion sequence that performs such a conversion 1827/// and this routine will return true. Otherwise, this routine returns 1828/// false and User is unspecified. 1829/// 1830/// \param AllowExplicit true if the conversion should consider C++0x 1831/// "explicit" conversion functions as well as non-explicit conversion 1832/// functions (C++0x [class.conv.fct]p2). 1833OverloadingResult Sema::IsUserDefinedConversion(Expr *From, QualType ToType, 1834 UserDefinedConversionSequence& User, 1835 OverloadCandidateSet& CandidateSet, 1836 bool AllowExplicit) { 1837 // Whether we will only visit constructors. 1838 bool ConstructorsOnly = false; 1839 1840 // If the type we are conversion to is a class type, enumerate its 1841 // constructors. 1842 if (const RecordType *ToRecordType = ToType->getAs<RecordType>()) { 1843 // C++ [over.match.ctor]p1: 1844 // When objects of class type are direct-initialized (8.5), or 1845 // copy-initialized from an expression of the same or a 1846 // derived class type (8.5), overload resolution selects the 1847 // constructor. [...] For copy-initialization, the candidate 1848 // functions are all the converting constructors (12.3.1) of 1849 // that class. The argument list is the expression-list within 1850 // the parentheses of the initializer. 1851 if (Context.hasSameUnqualifiedType(ToType, From->getType()) || 1852 (From->getType()->getAs<RecordType>() && 1853 IsDerivedFrom(From->getType(), ToType))) 1854 ConstructorsOnly = true; 1855 1856 if (RequireCompleteType(From->getLocStart(), ToType, PDiag())) { 1857 // We're not going to find any constructors. 1858 } else if (CXXRecordDecl *ToRecordDecl 1859 = dyn_cast<CXXRecordDecl>(ToRecordType->getDecl())) { 1860 DeclarationName ConstructorName 1861 = Context.DeclarationNames.getCXXConstructorName( 1862 Context.getCanonicalType(ToType).getUnqualifiedType()); 1863 DeclContext::lookup_iterator Con, ConEnd; 1864 for (llvm::tie(Con, ConEnd) 1865 = ToRecordDecl->lookup(ConstructorName); 1866 Con != ConEnd; ++Con) { 1867 NamedDecl *D = *Con; 1868 DeclAccessPair FoundDecl = DeclAccessPair::make(D, D->getAccess()); 1869 1870 // Find the constructor (which may be a template). 1871 CXXConstructorDecl *Constructor = 0; 1872 FunctionTemplateDecl *ConstructorTmpl 1873 = dyn_cast<FunctionTemplateDecl>(D); 1874 if (ConstructorTmpl) 1875 Constructor 1876 = cast<CXXConstructorDecl>(ConstructorTmpl->getTemplatedDecl()); 1877 else 1878 Constructor = cast<CXXConstructorDecl>(D); 1879 1880 if (!Constructor->isInvalidDecl() && 1881 Constructor->isConvertingConstructor(AllowExplicit)) { 1882 if (ConstructorTmpl) 1883 AddTemplateOverloadCandidate(ConstructorTmpl, FoundDecl, 1884 /*ExplicitArgs*/ 0, 1885 &From, 1, CandidateSet, 1886 /*SuppressUserConversions=*/!ConstructorsOnly); 1887 else 1888 // Allow one user-defined conversion when user specifies a 1889 // From->ToType conversion via an static cast (c-style, etc). 1890 AddOverloadCandidate(Constructor, FoundDecl, 1891 &From, 1, CandidateSet, 1892 /*SuppressUserConversions=*/!ConstructorsOnly); 1893 } 1894 } 1895 } 1896 } 1897 1898 // Enumerate conversion functions, if we're allowed to. 1899 if (ConstructorsOnly) { 1900 } else if (RequireCompleteType(From->getLocStart(), From->getType(), 1901 PDiag(0) << From->getSourceRange())) { 1902 // No conversion functions from incomplete types. 1903 } else if (const RecordType *FromRecordType 1904 = From->getType()->getAs<RecordType>()) { 1905 if (CXXRecordDecl *FromRecordDecl 1906 = dyn_cast<CXXRecordDecl>(FromRecordType->getDecl())) { 1907 // Add all of the conversion functions as candidates. 1908 const UnresolvedSetImpl *Conversions 1909 = FromRecordDecl->getVisibleConversionFunctions(); 1910 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 1911 E = Conversions->end(); I != E; ++I) { 1912 DeclAccessPair FoundDecl = I.getPair(); 1913 NamedDecl *D = FoundDecl.getDecl(); 1914 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext()); 1915 if (isa<UsingShadowDecl>(D)) 1916 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 1917 1918 CXXConversionDecl *Conv; 1919 FunctionTemplateDecl *ConvTemplate; 1920 if ((ConvTemplate = dyn_cast<FunctionTemplateDecl>(D))) 1921 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 1922 else 1923 Conv = cast<CXXConversionDecl>(D); 1924 1925 if (AllowExplicit || !Conv->isExplicit()) { 1926 if (ConvTemplate) 1927 AddTemplateConversionCandidate(ConvTemplate, FoundDecl, 1928 ActingContext, From, ToType, 1929 CandidateSet); 1930 else 1931 AddConversionCandidate(Conv, FoundDecl, ActingContext, 1932 From, ToType, CandidateSet); 1933 } 1934 } 1935 } 1936 } 1937 1938 OverloadCandidateSet::iterator Best; 1939 switch (BestViableFunction(CandidateSet, From->getLocStart(), Best)) { 1940 case OR_Success: 1941 // Record the standard conversion we used and the conversion function. 1942 if (CXXConstructorDecl *Constructor 1943 = dyn_cast<CXXConstructorDecl>(Best->Function)) { 1944 // C++ [over.ics.user]p1: 1945 // If the user-defined conversion is specified by a 1946 // constructor (12.3.1), the initial standard conversion 1947 // sequence converts the source type to the type required by 1948 // the argument of the constructor. 1949 // 1950 QualType ThisType = Constructor->getThisType(Context); 1951 if (Best->Conversions[0].isEllipsis()) 1952 User.EllipsisConversion = true; 1953 else { 1954 User.Before = Best->Conversions[0].Standard; 1955 User.EllipsisConversion = false; 1956 } 1957 User.ConversionFunction = Constructor; 1958 User.After.setAsIdentityConversion(); 1959 User.After.setFromType( 1960 ThisType->getAs<PointerType>()->getPointeeType()); 1961 User.After.setAllToTypes(ToType); 1962 return OR_Success; 1963 } else if (CXXConversionDecl *Conversion 1964 = dyn_cast<CXXConversionDecl>(Best->Function)) { 1965 // C++ [over.ics.user]p1: 1966 // 1967 // [...] If the user-defined conversion is specified by a 1968 // conversion function (12.3.2), the initial standard 1969 // conversion sequence converts the source type to the 1970 // implicit object parameter of the conversion function. 1971 User.Before = Best->Conversions[0].Standard; 1972 User.ConversionFunction = Conversion; 1973 User.EllipsisConversion = false; 1974 1975 // C++ [over.ics.user]p2: 1976 // The second standard conversion sequence converts the 1977 // result of the user-defined conversion to the target type 1978 // for the sequence. Since an implicit conversion sequence 1979 // is an initialization, the special rules for 1980 // initialization by user-defined conversion apply when 1981 // selecting the best user-defined conversion for a 1982 // user-defined conversion sequence (see 13.3.3 and 1983 // 13.3.3.1). 1984 User.After = Best->FinalConversion; 1985 return OR_Success; 1986 } else { 1987 assert(false && "Not a constructor or conversion function?"); 1988 return OR_No_Viable_Function; 1989 } 1990 1991 case OR_No_Viable_Function: 1992 return OR_No_Viable_Function; 1993 case OR_Deleted: 1994 // No conversion here! We're done. 1995 return OR_Deleted; 1996 1997 case OR_Ambiguous: 1998 return OR_Ambiguous; 1999 } 2000 2001 return OR_No_Viable_Function; 2002} 2003 2004bool 2005Sema::DiagnoseMultipleUserDefinedConversion(Expr *From, QualType ToType) { 2006 ImplicitConversionSequence ICS; 2007 OverloadCandidateSet CandidateSet(From->getExprLoc()); 2008 OverloadingResult OvResult = 2009 IsUserDefinedConversion(From, ToType, ICS.UserDefined, 2010 CandidateSet, false); 2011 if (OvResult == OR_Ambiguous) 2012 Diag(From->getSourceRange().getBegin(), 2013 diag::err_typecheck_ambiguous_condition) 2014 << From->getType() << ToType << From->getSourceRange(); 2015 else if (OvResult == OR_No_Viable_Function && !CandidateSet.empty()) 2016 Diag(From->getSourceRange().getBegin(), 2017 diag::err_typecheck_nonviable_condition) 2018 << From->getType() << ToType << From->getSourceRange(); 2019 else 2020 return false; 2021 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, &From, 1); 2022 return true; 2023} 2024 2025/// CompareImplicitConversionSequences - Compare two implicit 2026/// conversion sequences to determine whether one is better than the 2027/// other or if they are indistinguishable (C++ 13.3.3.2). 2028ImplicitConversionSequence::CompareKind 2029Sema::CompareImplicitConversionSequences(const ImplicitConversionSequence& ICS1, 2030 const ImplicitConversionSequence& ICS2) 2031{ 2032 // (C++ 13.3.3.2p2): When comparing the basic forms of implicit 2033 // conversion sequences (as defined in 13.3.3.1) 2034 // -- a standard conversion sequence (13.3.3.1.1) is a better 2035 // conversion sequence than a user-defined conversion sequence or 2036 // an ellipsis conversion sequence, and 2037 // -- a user-defined conversion sequence (13.3.3.1.2) is a better 2038 // conversion sequence than an ellipsis conversion sequence 2039 // (13.3.3.1.3). 2040 // 2041 // C++0x [over.best.ics]p10: 2042 // For the purpose of ranking implicit conversion sequences as 2043 // described in 13.3.3.2, the ambiguous conversion sequence is 2044 // treated as a user-defined sequence that is indistinguishable 2045 // from any other user-defined conversion sequence. 2046 if (ICS1.getKindRank() < ICS2.getKindRank()) 2047 return ImplicitConversionSequence::Better; 2048 else if (ICS2.getKindRank() < ICS1.getKindRank()) 2049 return ImplicitConversionSequence::Worse; 2050 2051 // The following checks require both conversion sequences to be of 2052 // the same kind. 2053 if (ICS1.getKind() != ICS2.getKind()) 2054 return ImplicitConversionSequence::Indistinguishable; 2055 2056 // Two implicit conversion sequences of the same form are 2057 // indistinguishable conversion sequences unless one of the 2058 // following rules apply: (C++ 13.3.3.2p3): 2059 if (ICS1.isStandard()) 2060 return CompareStandardConversionSequences(ICS1.Standard, ICS2.Standard); 2061 else if (ICS1.isUserDefined()) { 2062 // User-defined conversion sequence U1 is a better conversion 2063 // sequence than another user-defined conversion sequence U2 if 2064 // they contain the same user-defined conversion function or 2065 // constructor and if the second standard conversion sequence of 2066 // U1 is better than the second standard conversion sequence of 2067 // U2 (C++ 13.3.3.2p3). 2068 if (ICS1.UserDefined.ConversionFunction == 2069 ICS2.UserDefined.ConversionFunction) 2070 return CompareStandardConversionSequences(ICS1.UserDefined.After, 2071 ICS2.UserDefined.After); 2072 } 2073 2074 return ImplicitConversionSequence::Indistinguishable; 2075} 2076 2077static bool hasSimilarType(ASTContext &Context, QualType T1, QualType T2) { 2078 while (Context.UnwrapSimilarPointerTypes(T1, T2)) { 2079 Qualifiers Quals; 2080 T1 = Context.getUnqualifiedArrayType(T1, Quals); 2081 T2 = Context.getUnqualifiedArrayType(T2, Quals); 2082 } 2083 2084 return Context.hasSameUnqualifiedType(T1, T2); 2085} 2086 2087// Per 13.3.3.2p3, compare the given standard conversion sequences to 2088// determine if one is a proper subset of the other. 2089static ImplicitConversionSequence::CompareKind 2090compareStandardConversionSubsets(ASTContext &Context, 2091 const StandardConversionSequence& SCS1, 2092 const StandardConversionSequence& SCS2) { 2093 ImplicitConversionSequence::CompareKind Result 2094 = ImplicitConversionSequence::Indistinguishable; 2095 2096 // the identity conversion sequence is considered to be a subsequence of 2097 // any non-identity conversion sequence 2098 if (SCS1.ReferenceBinding == SCS2.ReferenceBinding) { 2099 if (SCS1.isIdentityConversion() && !SCS2.isIdentityConversion()) 2100 return ImplicitConversionSequence::Better; 2101 else if (!SCS1.isIdentityConversion() && SCS2.isIdentityConversion()) 2102 return ImplicitConversionSequence::Worse; 2103 } 2104 2105 if (SCS1.Second != SCS2.Second) { 2106 if (SCS1.Second == ICK_Identity) 2107 Result = ImplicitConversionSequence::Better; 2108 else if (SCS2.Second == ICK_Identity) 2109 Result = ImplicitConversionSequence::Worse; 2110 else 2111 return ImplicitConversionSequence::Indistinguishable; 2112 } else if (!hasSimilarType(Context, SCS1.getToType(1), SCS2.getToType(1))) 2113 return ImplicitConversionSequence::Indistinguishable; 2114 2115 if (SCS1.Third == SCS2.Third) { 2116 return Context.hasSameType(SCS1.getToType(2), SCS2.getToType(2))? Result 2117 : ImplicitConversionSequence::Indistinguishable; 2118 } 2119 2120 if (SCS1.Third == ICK_Identity) 2121 return Result == ImplicitConversionSequence::Worse 2122 ? ImplicitConversionSequence::Indistinguishable 2123 : ImplicitConversionSequence::Better; 2124 2125 if (SCS2.Third == ICK_Identity) 2126 return Result == ImplicitConversionSequence::Better 2127 ? ImplicitConversionSequence::Indistinguishable 2128 : ImplicitConversionSequence::Worse; 2129 2130 return ImplicitConversionSequence::Indistinguishable; 2131} 2132 2133/// CompareStandardConversionSequences - Compare two standard 2134/// conversion sequences to determine whether one is better than the 2135/// other or if they are indistinguishable (C++ 13.3.3.2p3). 2136ImplicitConversionSequence::CompareKind 2137Sema::CompareStandardConversionSequences(const StandardConversionSequence& SCS1, 2138 const StandardConversionSequence& SCS2) 2139{ 2140 // Standard conversion sequence S1 is a better conversion sequence 2141 // than standard conversion sequence S2 if (C++ 13.3.3.2p3): 2142 2143 // -- S1 is a proper subsequence of S2 (comparing the conversion 2144 // sequences in the canonical form defined by 13.3.3.1.1, 2145 // excluding any Lvalue Transformation; the identity conversion 2146 // sequence is considered to be a subsequence of any 2147 // non-identity conversion sequence) or, if not that, 2148 if (ImplicitConversionSequence::CompareKind CK 2149 = compareStandardConversionSubsets(Context, SCS1, SCS2)) 2150 return CK; 2151 2152 // -- the rank of S1 is better than the rank of S2 (by the rules 2153 // defined below), or, if not that, 2154 ImplicitConversionRank Rank1 = SCS1.getRank(); 2155 ImplicitConversionRank Rank2 = SCS2.getRank(); 2156 if (Rank1 < Rank2) 2157 return ImplicitConversionSequence::Better; 2158 else if (Rank2 < Rank1) 2159 return ImplicitConversionSequence::Worse; 2160 2161 // (C++ 13.3.3.2p4): Two conversion sequences with the same rank 2162 // are indistinguishable unless one of the following rules 2163 // applies: 2164 2165 // A conversion that is not a conversion of a pointer, or 2166 // pointer to member, to bool is better than another conversion 2167 // that is such a conversion. 2168 if (SCS1.isPointerConversionToBool() != SCS2.isPointerConversionToBool()) 2169 return SCS2.isPointerConversionToBool() 2170 ? ImplicitConversionSequence::Better 2171 : ImplicitConversionSequence::Worse; 2172 2173 // C++ [over.ics.rank]p4b2: 2174 // 2175 // If class B is derived directly or indirectly from class A, 2176 // conversion of B* to A* is better than conversion of B* to 2177 // void*, and conversion of A* to void* is better than conversion 2178 // of B* to void*. 2179 bool SCS1ConvertsToVoid 2180 = SCS1.isPointerConversionToVoidPointer(Context); 2181 bool SCS2ConvertsToVoid 2182 = SCS2.isPointerConversionToVoidPointer(Context); 2183 if (SCS1ConvertsToVoid != SCS2ConvertsToVoid) { 2184 // Exactly one of the conversion sequences is a conversion to 2185 // a void pointer; it's the worse conversion. 2186 return SCS2ConvertsToVoid ? ImplicitConversionSequence::Better 2187 : ImplicitConversionSequence::Worse; 2188 } else if (!SCS1ConvertsToVoid && !SCS2ConvertsToVoid) { 2189 // Neither conversion sequence converts to a void pointer; compare 2190 // their derived-to-base conversions. 2191 if (ImplicitConversionSequence::CompareKind DerivedCK 2192 = CompareDerivedToBaseConversions(SCS1, SCS2)) 2193 return DerivedCK; 2194 } else if (SCS1ConvertsToVoid && SCS2ConvertsToVoid) { 2195 // Both conversion sequences are conversions to void 2196 // pointers. Compare the source types to determine if there's an 2197 // inheritance relationship in their sources. 2198 QualType FromType1 = SCS1.getFromType(); 2199 QualType FromType2 = SCS2.getFromType(); 2200 2201 // Adjust the types we're converting from via the array-to-pointer 2202 // conversion, if we need to. 2203 if (SCS1.First == ICK_Array_To_Pointer) 2204 FromType1 = Context.getArrayDecayedType(FromType1); 2205 if (SCS2.First == ICK_Array_To_Pointer) 2206 FromType2 = Context.getArrayDecayedType(FromType2); 2207 2208 QualType FromPointee1 2209 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2210 QualType FromPointee2 2211 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2212 2213 if (IsDerivedFrom(FromPointee2, FromPointee1)) 2214 return ImplicitConversionSequence::Better; 2215 else if (IsDerivedFrom(FromPointee1, FromPointee2)) 2216 return ImplicitConversionSequence::Worse; 2217 2218 // Objective-C++: If one interface is more specific than the 2219 // other, it is the better one. 2220 const ObjCObjectType* FromIface1 = FromPointee1->getAs<ObjCObjectType>(); 2221 const ObjCObjectType* FromIface2 = FromPointee2->getAs<ObjCObjectType>(); 2222 if (FromIface1 && FromIface1) { 2223 if (Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 2224 return ImplicitConversionSequence::Better; 2225 else if (Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 2226 return ImplicitConversionSequence::Worse; 2227 } 2228 } 2229 2230 // Compare based on qualification conversions (C++ 13.3.3.2p3, 2231 // bullet 3). 2232 if (ImplicitConversionSequence::CompareKind QualCK 2233 = CompareQualificationConversions(SCS1, SCS2)) 2234 return QualCK; 2235 2236 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding) { 2237 // C++0x [over.ics.rank]p3b4: 2238 // -- S1 and S2 are reference bindings (8.5.3) and neither refers to an 2239 // implicit object parameter of a non-static member function declared 2240 // without a ref-qualifier, and S1 binds an rvalue reference to an 2241 // rvalue and S2 binds an lvalue reference. 2242 // FIXME: We don't know if we're dealing with the implicit object parameter, 2243 // or if the member function in this case has a ref qualifier. 2244 // (Of course, we don't have ref qualifiers yet.) 2245 if (SCS1.RRefBinding != SCS2.RRefBinding) 2246 return SCS1.RRefBinding ? ImplicitConversionSequence::Better 2247 : ImplicitConversionSequence::Worse; 2248 2249 // C++ [over.ics.rank]p3b4: 2250 // -- S1 and S2 are reference bindings (8.5.3), and the types to 2251 // which the references refer are the same type except for 2252 // top-level cv-qualifiers, and the type to which the reference 2253 // initialized by S2 refers is more cv-qualified than the type 2254 // to which the reference initialized by S1 refers. 2255 QualType T1 = SCS1.getToType(2); 2256 QualType T2 = SCS2.getToType(2); 2257 T1 = Context.getCanonicalType(T1); 2258 T2 = Context.getCanonicalType(T2); 2259 Qualifiers T1Quals, T2Quals; 2260 QualType UnqualT1 = Context.getUnqualifiedArrayType(T1, T1Quals); 2261 QualType UnqualT2 = Context.getUnqualifiedArrayType(T2, T2Quals); 2262 if (UnqualT1 == UnqualT2) { 2263 // If the type is an array type, promote the element qualifiers to the type 2264 // for comparison. 2265 if (isa<ArrayType>(T1) && T1Quals) 2266 T1 = Context.getQualifiedType(UnqualT1, T1Quals); 2267 if (isa<ArrayType>(T2) && T2Quals) 2268 T2 = Context.getQualifiedType(UnqualT2, T2Quals); 2269 if (T2.isMoreQualifiedThan(T1)) 2270 return ImplicitConversionSequence::Better; 2271 else if (T1.isMoreQualifiedThan(T2)) 2272 return ImplicitConversionSequence::Worse; 2273 } 2274 } 2275 2276 return ImplicitConversionSequence::Indistinguishable; 2277} 2278 2279/// CompareQualificationConversions - Compares two standard conversion 2280/// sequences to determine whether they can be ranked based on their 2281/// qualification conversions (C++ 13.3.3.2p3 bullet 3). 2282ImplicitConversionSequence::CompareKind 2283Sema::CompareQualificationConversions(const StandardConversionSequence& SCS1, 2284 const StandardConversionSequence& SCS2) { 2285 // C++ 13.3.3.2p3: 2286 // -- S1 and S2 differ only in their qualification conversion and 2287 // yield similar types T1 and T2 (C++ 4.4), respectively, and the 2288 // cv-qualification signature of type T1 is a proper subset of 2289 // the cv-qualification signature of type T2, and S1 is not the 2290 // deprecated string literal array-to-pointer conversion (4.2). 2291 if (SCS1.First != SCS2.First || SCS1.Second != SCS2.Second || 2292 SCS1.Third != SCS2.Third || SCS1.Third != ICK_Qualification) 2293 return ImplicitConversionSequence::Indistinguishable; 2294 2295 // FIXME: the example in the standard doesn't use a qualification 2296 // conversion (!) 2297 QualType T1 = SCS1.getToType(2); 2298 QualType T2 = SCS2.getToType(2); 2299 T1 = Context.getCanonicalType(T1); 2300 T2 = Context.getCanonicalType(T2); 2301 Qualifiers T1Quals, T2Quals; 2302 QualType UnqualT1 = Context.getUnqualifiedArrayType(T1, T1Quals); 2303 QualType UnqualT2 = Context.getUnqualifiedArrayType(T2, T2Quals); 2304 2305 // If the types are the same, we won't learn anything by unwrapped 2306 // them. 2307 if (UnqualT1 == UnqualT2) 2308 return ImplicitConversionSequence::Indistinguishable; 2309 2310 // If the type is an array type, promote the element qualifiers to the type 2311 // for comparison. 2312 if (isa<ArrayType>(T1) && T1Quals) 2313 T1 = Context.getQualifiedType(UnqualT1, T1Quals); 2314 if (isa<ArrayType>(T2) && T2Quals) 2315 T2 = Context.getQualifiedType(UnqualT2, T2Quals); 2316 2317 ImplicitConversionSequence::CompareKind Result 2318 = ImplicitConversionSequence::Indistinguishable; 2319 while (Context.UnwrapSimilarPointerTypes(T1, T2)) { 2320 // Within each iteration of the loop, we check the qualifiers to 2321 // determine if this still looks like a qualification 2322 // conversion. Then, if all is well, we unwrap one more level of 2323 // pointers or pointers-to-members and do it all again 2324 // until there are no more pointers or pointers-to-members left 2325 // to unwrap. This essentially mimics what 2326 // IsQualificationConversion does, but here we're checking for a 2327 // strict subset of qualifiers. 2328 if (T1.getCVRQualifiers() == T2.getCVRQualifiers()) 2329 // The qualifiers are the same, so this doesn't tell us anything 2330 // about how the sequences rank. 2331 ; 2332 else if (T2.isMoreQualifiedThan(T1)) { 2333 // T1 has fewer qualifiers, so it could be the better sequence. 2334 if (Result == ImplicitConversionSequence::Worse) 2335 // Neither has qualifiers that are a subset of the other's 2336 // qualifiers. 2337 return ImplicitConversionSequence::Indistinguishable; 2338 2339 Result = ImplicitConversionSequence::Better; 2340 } else if (T1.isMoreQualifiedThan(T2)) { 2341 // T2 has fewer qualifiers, so it could be the better sequence. 2342 if (Result == ImplicitConversionSequence::Better) 2343 // Neither has qualifiers that are a subset of the other's 2344 // qualifiers. 2345 return ImplicitConversionSequence::Indistinguishable; 2346 2347 Result = ImplicitConversionSequence::Worse; 2348 } else { 2349 // Qualifiers are disjoint. 2350 return ImplicitConversionSequence::Indistinguishable; 2351 } 2352 2353 // If the types after this point are equivalent, we're done. 2354 if (Context.hasSameUnqualifiedType(T1, T2)) 2355 break; 2356 } 2357 2358 // Check that the winning standard conversion sequence isn't using 2359 // the deprecated string literal array to pointer conversion. 2360 switch (Result) { 2361 case ImplicitConversionSequence::Better: 2362 if (SCS1.DeprecatedStringLiteralToCharPtr) 2363 Result = ImplicitConversionSequence::Indistinguishable; 2364 break; 2365 2366 case ImplicitConversionSequence::Indistinguishable: 2367 break; 2368 2369 case ImplicitConversionSequence::Worse: 2370 if (SCS2.DeprecatedStringLiteralToCharPtr) 2371 Result = ImplicitConversionSequence::Indistinguishable; 2372 break; 2373 } 2374 2375 return Result; 2376} 2377 2378/// CompareDerivedToBaseConversions - Compares two standard conversion 2379/// sequences to determine whether they can be ranked based on their 2380/// various kinds of derived-to-base conversions (C++ 2381/// [over.ics.rank]p4b3). As part of these checks, we also look at 2382/// conversions between Objective-C interface types. 2383ImplicitConversionSequence::CompareKind 2384Sema::CompareDerivedToBaseConversions(const StandardConversionSequence& SCS1, 2385 const StandardConversionSequence& SCS2) { 2386 QualType FromType1 = SCS1.getFromType(); 2387 QualType ToType1 = SCS1.getToType(1); 2388 QualType FromType2 = SCS2.getFromType(); 2389 QualType ToType2 = SCS2.getToType(1); 2390 2391 // Adjust the types we're converting from via the array-to-pointer 2392 // conversion, if we need to. 2393 if (SCS1.First == ICK_Array_To_Pointer) 2394 FromType1 = Context.getArrayDecayedType(FromType1); 2395 if (SCS2.First == ICK_Array_To_Pointer) 2396 FromType2 = Context.getArrayDecayedType(FromType2); 2397 2398 // Canonicalize all of the types. 2399 FromType1 = Context.getCanonicalType(FromType1); 2400 ToType1 = Context.getCanonicalType(ToType1); 2401 FromType2 = Context.getCanonicalType(FromType2); 2402 ToType2 = Context.getCanonicalType(ToType2); 2403 2404 // C++ [over.ics.rank]p4b3: 2405 // 2406 // If class B is derived directly or indirectly from class A and 2407 // class C is derived directly or indirectly from B, 2408 // 2409 // For Objective-C, we let A, B, and C also be Objective-C 2410 // interfaces. 2411 2412 // Compare based on pointer conversions. 2413 if (SCS1.Second == ICK_Pointer_Conversion && 2414 SCS2.Second == ICK_Pointer_Conversion && 2415 /*FIXME: Remove if Objective-C id conversions get their own rank*/ 2416 FromType1->isPointerType() && FromType2->isPointerType() && 2417 ToType1->isPointerType() && ToType2->isPointerType()) { 2418 QualType FromPointee1 2419 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2420 QualType ToPointee1 2421 = ToType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2422 QualType FromPointee2 2423 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2424 QualType ToPointee2 2425 = ToType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2426 2427 const ObjCObjectType* FromIface1 = FromPointee1->getAs<ObjCObjectType>(); 2428 const ObjCObjectType* FromIface2 = FromPointee2->getAs<ObjCObjectType>(); 2429 const ObjCObjectType* ToIface1 = ToPointee1->getAs<ObjCObjectType>(); 2430 const ObjCObjectType* ToIface2 = ToPointee2->getAs<ObjCObjectType>(); 2431 2432 // -- conversion of C* to B* is better than conversion of C* to A*, 2433 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 2434 if (IsDerivedFrom(ToPointee1, ToPointee2)) 2435 return ImplicitConversionSequence::Better; 2436 else if (IsDerivedFrom(ToPointee2, ToPointee1)) 2437 return ImplicitConversionSequence::Worse; 2438 2439 if (ToIface1 && ToIface2) { 2440 if (Context.canAssignObjCInterfaces(ToIface2, ToIface1)) 2441 return ImplicitConversionSequence::Better; 2442 else if (Context.canAssignObjCInterfaces(ToIface1, ToIface2)) 2443 return ImplicitConversionSequence::Worse; 2444 } 2445 } 2446 2447 // -- conversion of B* to A* is better than conversion of C* to A*, 2448 if (FromPointee1 != FromPointee2 && ToPointee1 == ToPointee2) { 2449 if (IsDerivedFrom(FromPointee2, FromPointee1)) 2450 return ImplicitConversionSequence::Better; 2451 else if (IsDerivedFrom(FromPointee1, FromPointee2)) 2452 return ImplicitConversionSequence::Worse; 2453 2454 if (FromIface1 && FromIface2) { 2455 if (Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 2456 return ImplicitConversionSequence::Better; 2457 else if (Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 2458 return ImplicitConversionSequence::Worse; 2459 } 2460 } 2461 } 2462 2463 // Ranking of member-pointer types. 2464 if (SCS1.Second == ICK_Pointer_Member && SCS2.Second == ICK_Pointer_Member && 2465 FromType1->isMemberPointerType() && FromType2->isMemberPointerType() && 2466 ToType1->isMemberPointerType() && ToType2->isMemberPointerType()) { 2467 const MemberPointerType * FromMemPointer1 = 2468 FromType1->getAs<MemberPointerType>(); 2469 const MemberPointerType * ToMemPointer1 = 2470 ToType1->getAs<MemberPointerType>(); 2471 const MemberPointerType * FromMemPointer2 = 2472 FromType2->getAs<MemberPointerType>(); 2473 const MemberPointerType * ToMemPointer2 = 2474 ToType2->getAs<MemberPointerType>(); 2475 const Type *FromPointeeType1 = FromMemPointer1->getClass(); 2476 const Type *ToPointeeType1 = ToMemPointer1->getClass(); 2477 const Type *FromPointeeType2 = FromMemPointer2->getClass(); 2478 const Type *ToPointeeType2 = ToMemPointer2->getClass(); 2479 QualType FromPointee1 = QualType(FromPointeeType1, 0).getUnqualifiedType(); 2480 QualType ToPointee1 = QualType(ToPointeeType1, 0).getUnqualifiedType(); 2481 QualType FromPointee2 = QualType(FromPointeeType2, 0).getUnqualifiedType(); 2482 QualType ToPointee2 = QualType(ToPointeeType2, 0).getUnqualifiedType(); 2483 // conversion of A::* to B::* is better than conversion of A::* to C::*, 2484 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 2485 if (IsDerivedFrom(ToPointee1, ToPointee2)) 2486 return ImplicitConversionSequence::Worse; 2487 else if (IsDerivedFrom(ToPointee2, ToPointee1)) 2488 return ImplicitConversionSequence::Better; 2489 } 2490 // conversion of B::* to C::* is better than conversion of A::* to C::* 2491 if (ToPointee1 == ToPointee2 && FromPointee1 != FromPointee2) { 2492 if (IsDerivedFrom(FromPointee1, FromPointee2)) 2493 return ImplicitConversionSequence::Better; 2494 else if (IsDerivedFrom(FromPointee2, FromPointee1)) 2495 return ImplicitConversionSequence::Worse; 2496 } 2497 } 2498 2499 if (SCS1.Second == ICK_Derived_To_Base) { 2500 // -- conversion of C to B is better than conversion of C to A, 2501 // -- binding of an expression of type C to a reference of type 2502 // B& is better than binding an expression of type C to a 2503 // reference of type A&, 2504 if (Context.hasSameUnqualifiedType(FromType1, FromType2) && 2505 !Context.hasSameUnqualifiedType(ToType1, ToType2)) { 2506 if (IsDerivedFrom(ToType1, ToType2)) 2507 return ImplicitConversionSequence::Better; 2508 else if (IsDerivedFrom(ToType2, ToType1)) 2509 return ImplicitConversionSequence::Worse; 2510 } 2511 2512 // -- conversion of B to A is better than conversion of C to A. 2513 // -- binding of an expression of type B to a reference of type 2514 // A& is better than binding an expression of type C to a 2515 // reference of type A&, 2516 if (!Context.hasSameUnqualifiedType(FromType1, FromType2) && 2517 Context.hasSameUnqualifiedType(ToType1, ToType2)) { 2518 if (IsDerivedFrom(FromType2, FromType1)) 2519 return ImplicitConversionSequence::Better; 2520 else if (IsDerivedFrom(FromType1, FromType2)) 2521 return ImplicitConversionSequence::Worse; 2522 } 2523 } 2524 2525 return ImplicitConversionSequence::Indistinguishable; 2526} 2527 2528/// CompareReferenceRelationship - Compare the two types T1 and T2 to 2529/// determine whether they are reference-related, 2530/// reference-compatible, reference-compatible with added 2531/// qualification, or incompatible, for use in C++ initialization by 2532/// reference (C++ [dcl.ref.init]p4). Neither type can be a reference 2533/// type, and the first type (T1) is the pointee type of the reference 2534/// type being initialized. 2535Sema::ReferenceCompareResult 2536Sema::CompareReferenceRelationship(SourceLocation Loc, 2537 QualType OrigT1, QualType OrigT2, 2538 bool& DerivedToBase) { 2539 assert(!OrigT1->isReferenceType() && 2540 "T1 must be the pointee type of the reference type"); 2541 assert(!OrigT2->isReferenceType() && "T2 cannot be a reference type"); 2542 2543 QualType T1 = Context.getCanonicalType(OrigT1); 2544 QualType T2 = Context.getCanonicalType(OrigT2); 2545 Qualifiers T1Quals, T2Quals; 2546 QualType UnqualT1 = Context.getUnqualifiedArrayType(T1, T1Quals); 2547 QualType UnqualT2 = Context.getUnqualifiedArrayType(T2, T2Quals); 2548 2549 // C++ [dcl.init.ref]p4: 2550 // Given types "cv1 T1" and "cv2 T2," "cv1 T1" is 2551 // reference-related to "cv2 T2" if T1 is the same type as T2, or 2552 // T1 is a base class of T2. 2553 if (UnqualT1 == UnqualT2) 2554 DerivedToBase = false; 2555 else if (!RequireCompleteType(Loc, OrigT2, PDiag()) && 2556 IsDerivedFrom(UnqualT2, UnqualT1)) 2557 DerivedToBase = true; 2558 else 2559 return Ref_Incompatible; 2560 2561 // At this point, we know that T1 and T2 are reference-related (at 2562 // least). 2563 2564 // If the type is an array type, promote the element qualifiers to the type 2565 // for comparison. 2566 if (isa<ArrayType>(T1) && T1Quals) 2567 T1 = Context.getQualifiedType(UnqualT1, T1Quals); 2568 if (isa<ArrayType>(T2) && T2Quals) 2569 T2 = Context.getQualifiedType(UnqualT2, T2Quals); 2570 2571 // C++ [dcl.init.ref]p4: 2572 // "cv1 T1" is reference-compatible with "cv2 T2" if T1 is 2573 // reference-related to T2 and cv1 is the same cv-qualification 2574 // as, or greater cv-qualification than, cv2. For purposes of 2575 // overload resolution, cases for which cv1 is greater 2576 // cv-qualification than cv2 are identified as 2577 // reference-compatible with added qualification (see 13.3.3.2). 2578 if (T1Quals.getCVRQualifiers() == T2Quals.getCVRQualifiers()) 2579 return Ref_Compatible; 2580 else if (T1.isMoreQualifiedThan(T2)) 2581 return Ref_Compatible_With_Added_Qualification; 2582 else 2583 return Ref_Related; 2584} 2585 2586/// \brief Compute an implicit conversion sequence for reference 2587/// initialization. 2588static ImplicitConversionSequence 2589TryReferenceInit(Sema &S, Expr *&Init, QualType DeclType, 2590 SourceLocation DeclLoc, 2591 bool SuppressUserConversions, 2592 bool AllowExplicit) { 2593 assert(DeclType->isReferenceType() && "Reference init needs a reference"); 2594 2595 // Most paths end in a failed conversion. 2596 ImplicitConversionSequence ICS; 2597 ICS.setBad(BadConversionSequence::no_conversion, Init, DeclType); 2598 2599 QualType T1 = DeclType->getAs<ReferenceType>()->getPointeeType(); 2600 QualType T2 = Init->getType(); 2601 2602 // If the initializer is the address of an overloaded function, try 2603 // to resolve the overloaded function. If all goes well, T2 is the 2604 // type of the resulting function. 2605 if (S.Context.getCanonicalType(T2) == S.Context.OverloadTy) { 2606 DeclAccessPair Found; 2607 if (FunctionDecl *Fn = S.ResolveAddressOfOverloadedFunction(Init, DeclType, 2608 false, Found)) 2609 T2 = Fn->getType(); 2610 } 2611 2612 // Compute some basic properties of the types and the initializer. 2613 bool isRValRef = DeclType->isRValueReferenceType(); 2614 bool DerivedToBase = false; 2615 Expr::isLvalueResult InitLvalue = Init->isLvalue(S.Context); 2616 Sema::ReferenceCompareResult RefRelationship 2617 = S.CompareReferenceRelationship(DeclLoc, T1, T2, DerivedToBase); 2618 2619 2620 // C++ [over.ics.ref]p3: 2621 // Except for an implicit object parameter, for which see 13.3.1, 2622 // a standard conversion sequence cannot be formed if it requires 2623 // binding an lvalue reference to non-const to an rvalue or 2624 // binding an rvalue reference to an lvalue. 2625 // 2626 // FIXME: DPG doesn't trust this code. It seems far too early to 2627 // abort because of a binding of an rvalue reference to an lvalue. 2628 if (isRValRef && InitLvalue == Expr::LV_Valid) 2629 return ICS; 2630 2631 // C++0x [dcl.init.ref]p16: 2632 // A reference to type "cv1 T1" is initialized by an expression 2633 // of type "cv2 T2" as follows: 2634 2635 // -- If the initializer expression 2636 // -- is an lvalue (but is not a bit-field), and "cv1 T1" is 2637 // reference-compatible with "cv2 T2," or 2638 // 2639 // Per C++ [over.ics.ref]p4, we don't check the bit-field property here. 2640 if (InitLvalue == Expr::LV_Valid && 2641 RefRelationship >= Sema::Ref_Compatible_With_Added_Qualification) { 2642 // C++ [over.ics.ref]p1: 2643 // When a parameter of reference type binds directly (8.5.3) 2644 // to an argument expression, the implicit conversion sequence 2645 // is the identity conversion, unless the argument expression 2646 // has a type that is a derived class of the parameter type, 2647 // in which case the implicit conversion sequence is a 2648 // derived-to-base Conversion (13.3.3.1). 2649 ICS.setStandard(); 2650 ICS.Standard.First = ICK_Identity; 2651 ICS.Standard.Second = DerivedToBase? ICK_Derived_To_Base : ICK_Identity; 2652 ICS.Standard.Third = ICK_Identity; 2653 ICS.Standard.FromTypePtr = T2.getAsOpaquePtr(); 2654 ICS.Standard.setToType(0, T2); 2655 ICS.Standard.setToType(1, T1); 2656 ICS.Standard.setToType(2, T1); 2657 ICS.Standard.ReferenceBinding = true; 2658 ICS.Standard.DirectBinding = true; 2659 ICS.Standard.RRefBinding = false; 2660 ICS.Standard.CopyConstructor = 0; 2661 2662 // Nothing more to do: the inaccessibility/ambiguity check for 2663 // derived-to-base conversions is suppressed when we're 2664 // computing the implicit conversion sequence (C++ 2665 // [over.best.ics]p2). 2666 return ICS; 2667 } 2668 2669 // -- has a class type (i.e., T2 is a class type), where T1 is 2670 // not reference-related to T2, and can be implicitly 2671 // converted to an lvalue of type "cv3 T3," where "cv1 T1" 2672 // is reference-compatible with "cv3 T3" 92) (this 2673 // conversion is selected by enumerating the applicable 2674 // conversion functions (13.3.1.6) and choosing the best 2675 // one through overload resolution (13.3)), 2676 if (!isRValRef && !SuppressUserConversions && T2->isRecordType() && 2677 !S.RequireCompleteType(DeclLoc, T2, 0) && 2678 RefRelationship == Sema::Ref_Incompatible) { 2679 CXXRecordDecl *T2RecordDecl 2680 = dyn_cast<CXXRecordDecl>(T2->getAs<RecordType>()->getDecl()); 2681 2682 OverloadCandidateSet CandidateSet(DeclLoc); 2683 const UnresolvedSetImpl *Conversions 2684 = T2RecordDecl->getVisibleConversionFunctions(); 2685 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 2686 E = Conversions->end(); I != E; ++I) { 2687 NamedDecl *D = *I; 2688 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(D->getDeclContext()); 2689 if (isa<UsingShadowDecl>(D)) 2690 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 2691 2692 FunctionTemplateDecl *ConvTemplate 2693 = dyn_cast<FunctionTemplateDecl>(D); 2694 CXXConversionDecl *Conv; 2695 if (ConvTemplate) 2696 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 2697 else 2698 Conv = cast<CXXConversionDecl>(D); 2699 2700 // If the conversion function doesn't return a reference type, 2701 // it can't be considered for this conversion. 2702 if (Conv->getConversionType()->isLValueReferenceType() && 2703 (AllowExplicit || !Conv->isExplicit())) { 2704 if (ConvTemplate) 2705 S.AddTemplateConversionCandidate(ConvTemplate, I.getPair(), ActingDC, 2706 Init, DeclType, CandidateSet); 2707 else 2708 S.AddConversionCandidate(Conv, I.getPair(), ActingDC, Init, 2709 DeclType, CandidateSet); 2710 } 2711 } 2712 2713 OverloadCandidateSet::iterator Best; 2714 switch (S.BestViableFunction(CandidateSet, DeclLoc, Best)) { 2715 case OR_Success: 2716 // C++ [over.ics.ref]p1: 2717 // 2718 // [...] If the parameter binds directly to the result of 2719 // applying a conversion function to the argument 2720 // expression, the implicit conversion sequence is a 2721 // user-defined conversion sequence (13.3.3.1.2), with the 2722 // second standard conversion sequence either an identity 2723 // conversion or, if the conversion function returns an 2724 // entity of a type that is a derived class of the parameter 2725 // type, a derived-to-base Conversion. 2726 if (!Best->FinalConversion.DirectBinding) 2727 break; 2728 2729 ICS.setUserDefined(); 2730 ICS.UserDefined.Before = Best->Conversions[0].Standard; 2731 ICS.UserDefined.After = Best->FinalConversion; 2732 ICS.UserDefined.ConversionFunction = Best->Function; 2733 ICS.UserDefined.EllipsisConversion = false; 2734 assert(ICS.UserDefined.After.ReferenceBinding && 2735 ICS.UserDefined.After.DirectBinding && 2736 "Expected a direct reference binding!"); 2737 return ICS; 2738 2739 case OR_Ambiguous: 2740 ICS.setAmbiguous(); 2741 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 2742 Cand != CandidateSet.end(); ++Cand) 2743 if (Cand->Viable) 2744 ICS.Ambiguous.addConversion(Cand->Function); 2745 return ICS; 2746 2747 case OR_No_Viable_Function: 2748 case OR_Deleted: 2749 // There was no suitable conversion, or we found a deleted 2750 // conversion; continue with other checks. 2751 break; 2752 } 2753 } 2754 2755 // -- Otherwise, the reference shall be to a non-volatile const 2756 // type (i.e., cv1 shall be const), or the reference shall be an 2757 // rvalue reference and the initializer expression shall be an rvalue. 2758 // 2759 // We actually handle one oddity of C++ [over.ics.ref] at this 2760 // point, which is that, due to p2 (which short-circuits reference 2761 // binding by only attempting a simple conversion for non-direct 2762 // bindings) and p3's strange wording, we allow a const volatile 2763 // reference to bind to an rvalue. Hence the check for the presence 2764 // of "const" rather than checking for "const" being the only 2765 // qualifier. 2766 if (!isRValRef && !T1.isConstQualified()) 2767 return ICS; 2768 2769 // -- if T2 is a class type and 2770 // -- the initializer expression is an rvalue and "cv1 T1" 2771 // is reference-compatible with "cv2 T2," or 2772 // 2773 // -- T1 is not reference-related to T2 and the initializer 2774 // expression can be implicitly converted to an rvalue 2775 // of type "cv3 T3" (this conversion is selected by 2776 // enumerating the applicable conversion functions 2777 // (13.3.1.6) and choosing the best one through overload 2778 // resolution (13.3)), 2779 // 2780 // then the reference is bound to the initializer 2781 // expression rvalue in the first case and to the object 2782 // that is the result of the conversion in the second case 2783 // (or, in either case, to the appropriate base class 2784 // subobject of the object). 2785 // 2786 // We're only checking the first case here, which is a direct 2787 // binding in C++0x but not in C++03. 2788 if (InitLvalue != Expr::LV_Valid && T2->isRecordType() && 2789 RefRelationship >= Sema::Ref_Compatible_With_Added_Qualification) { 2790 ICS.setStandard(); 2791 ICS.Standard.First = ICK_Identity; 2792 ICS.Standard.Second = DerivedToBase? ICK_Derived_To_Base : ICK_Identity; 2793 ICS.Standard.Third = ICK_Identity; 2794 ICS.Standard.FromTypePtr = T2.getAsOpaquePtr(); 2795 ICS.Standard.setToType(0, T2); 2796 ICS.Standard.setToType(1, T1); 2797 ICS.Standard.setToType(2, T1); 2798 ICS.Standard.ReferenceBinding = true; 2799 ICS.Standard.DirectBinding = S.getLangOptions().CPlusPlus0x; 2800 ICS.Standard.RRefBinding = isRValRef; 2801 ICS.Standard.CopyConstructor = 0; 2802 return ICS; 2803 } 2804 2805 // -- Otherwise, a temporary of type "cv1 T1" is created and 2806 // initialized from the initializer expression using the 2807 // rules for a non-reference copy initialization (8.5). The 2808 // reference is then bound to the temporary. If T1 is 2809 // reference-related to T2, cv1 must be the same 2810 // cv-qualification as, or greater cv-qualification than, 2811 // cv2; otherwise, the program is ill-formed. 2812 if (RefRelationship == Sema::Ref_Related) { 2813 // If cv1 == cv2 or cv1 is a greater cv-qualified than cv2, then 2814 // we would be reference-compatible or reference-compatible with 2815 // added qualification. But that wasn't the case, so the reference 2816 // initialization fails. 2817 return ICS; 2818 } 2819 2820 // If at least one of the types is a class type, the types are not 2821 // related, and we aren't allowed any user conversions, the 2822 // reference binding fails. This case is important for breaking 2823 // recursion, since TryImplicitConversion below will attempt to 2824 // create a temporary through the use of a copy constructor. 2825 if (SuppressUserConversions && RefRelationship == Sema::Ref_Incompatible && 2826 (T1->isRecordType() || T2->isRecordType())) 2827 return ICS; 2828 2829 // C++ [over.ics.ref]p2: 2830 // When a parameter of reference type is not bound directly to 2831 // an argument expression, the conversion sequence is the one 2832 // required to convert the argument expression to the 2833 // underlying type of the reference according to 2834 // 13.3.3.1. Conceptually, this conversion sequence corresponds 2835 // to copy-initializing a temporary of the underlying type with 2836 // the argument expression. Any difference in top-level 2837 // cv-qualification is subsumed by the initialization itself 2838 // and does not constitute a conversion. 2839 ICS = S.TryImplicitConversion(Init, T1, SuppressUserConversions, 2840 /*AllowExplicit=*/false, 2841 /*InOverloadResolution=*/false); 2842 2843 // Of course, that's still a reference binding. 2844 if (ICS.isStandard()) { 2845 ICS.Standard.ReferenceBinding = true; 2846 ICS.Standard.RRefBinding = isRValRef; 2847 } else if (ICS.isUserDefined()) { 2848 ICS.UserDefined.After.ReferenceBinding = true; 2849 ICS.UserDefined.After.RRefBinding = isRValRef; 2850 } 2851 return ICS; 2852} 2853 2854/// TryCopyInitialization - Try to copy-initialize a value of type 2855/// ToType from the expression From. Return the implicit conversion 2856/// sequence required to pass this argument, which may be a bad 2857/// conversion sequence (meaning that the argument cannot be passed to 2858/// a parameter of this type). If @p SuppressUserConversions, then we 2859/// do not permit any user-defined conversion sequences. 2860static ImplicitConversionSequence 2861TryCopyInitialization(Sema &S, Expr *From, QualType ToType, 2862 bool SuppressUserConversions, 2863 bool InOverloadResolution) { 2864 if (ToType->isReferenceType()) 2865 return TryReferenceInit(S, From, ToType, 2866 /*FIXME:*/From->getLocStart(), 2867 SuppressUserConversions, 2868 /*AllowExplicit=*/false); 2869 2870 return S.TryImplicitConversion(From, ToType, 2871 SuppressUserConversions, 2872 /*AllowExplicit=*/false, 2873 InOverloadResolution); 2874} 2875 2876/// TryObjectArgumentInitialization - Try to initialize the object 2877/// parameter of the given member function (@c Method) from the 2878/// expression @p From. 2879ImplicitConversionSequence 2880Sema::TryObjectArgumentInitialization(QualType OrigFromType, 2881 CXXMethodDecl *Method, 2882 CXXRecordDecl *ActingContext) { 2883 QualType ClassType = Context.getTypeDeclType(ActingContext); 2884 // [class.dtor]p2: A destructor can be invoked for a const, volatile or 2885 // const volatile object. 2886 unsigned Quals = isa<CXXDestructorDecl>(Method) ? 2887 Qualifiers::Const | Qualifiers::Volatile : Method->getTypeQualifiers(); 2888 QualType ImplicitParamType = Context.getCVRQualifiedType(ClassType, Quals); 2889 2890 // Set up the conversion sequence as a "bad" conversion, to allow us 2891 // to exit early. 2892 ImplicitConversionSequence ICS; 2893 2894 // We need to have an object of class type. 2895 QualType FromType = OrigFromType; 2896 if (const PointerType *PT = FromType->getAs<PointerType>()) 2897 FromType = PT->getPointeeType(); 2898 2899 assert(FromType->isRecordType()); 2900 2901 // The implicit object parameter is has the type "reference to cv X", 2902 // where X is the class of which the function is a member 2903 // (C++ [over.match.funcs]p4). However, when finding an implicit 2904 // conversion sequence for the argument, we are not allowed to 2905 // create temporaries or perform user-defined conversions 2906 // (C++ [over.match.funcs]p5). We perform a simplified version of 2907 // reference binding here, that allows class rvalues to bind to 2908 // non-constant references. 2909 2910 // First check the qualifiers. We don't care about lvalue-vs-rvalue 2911 // with the implicit object parameter (C++ [over.match.funcs]p5). 2912 QualType FromTypeCanon = Context.getCanonicalType(FromType); 2913 if (ImplicitParamType.getCVRQualifiers() 2914 != FromTypeCanon.getLocalCVRQualifiers() && 2915 !ImplicitParamType.isAtLeastAsQualifiedAs(FromTypeCanon)) { 2916 ICS.setBad(BadConversionSequence::bad_qualifiers, 2917 OrigFromType, ImplicitParamType); 2918 return ICS; 2919 } 2920 2921 // Check that we have either the same type or a derived type. It 2922 // affects the conversion rank. 2923 QualType ClassTypeCanon = Context.getCanonicalType(ClassType); 2924 ImplicitConversionKind SecondKind; 2925 if (ClassTypeCanon == FromTypeCanon.getLocalUnqualifiedType()) { 2926 SecondKind = ICK_Identity; 2927 } else if (IsDerivedFrom(FromType, ClassType)) 2928 SecondKind = ICK_Derived_To_Base; 2929 else { 2930 ICS.setBad(BadConversionSequence::unrelated_class, 2931 FromType, ImplicitParamType); 2932 return ICS; 2933 } 2934 2935 // Success. Mark this as a reference binding. 2936 ICS.setStandard(); 2937 ICS.Standard.setAsIdentityConversion(); 2938 ICS.Standard.Second = SecondKind; 2939 ICS.Standard.setFromType(FromType); 2940 ICS.Standard.setAllToTypes(ImplicitParamType); 2941 ICS.Standard.ReferenceBinding = true; 2942 ICS.Standard.DirectBinding = true; 2943 ICS.Standard.RRefBinding = false; 2944 return ICS; 2945} 2946 2947/// PerformObjectArgumentInitialization - Perform initialization of 2948/// the implicit object parameter for the given Method with the given 2949/// expression. 2950bool 2951Sema::PerformObjectArgumentInitialization(Expr *&From, 2952 NestedNameSpecifier *Qualifier, 2953 NamedDecl *FoundDecl, 2954 CXXMethodDecl *Method) { 2955 QualType FromRecordType, DestType; 2956 QualType ImplicitParamRecordType = 2957 Method->getThisType(Context)->getAs<PointerType>()->getPointeeType(); 2958 2959 if (const PointerType *PT = From->getType()->getAs<PointerType>()) { 2960 FromRecordType = PT->getPointeeType(); 2961 DestType = Method->getThisType(Context); 2962 } else { 2963 FromRecordType = From->getType(); 2964 DestType = ImplicitParamRecordType; 2965 } 2966 2967 // Note that we always use the true parent context when performing 2968 // the actual argument initialization. 2969 ImplicitConversionSequence ICS 2970 = TryObjectArgumentInitialization(From->getType(), Method, 2971 Method->getParent()); 2972 if (ICS.isBad()) 2973 return Diag(From->getSourceRange().getBegin(), 2974 diag::err_implicit_object_parameter_init) 2975 << ImplicitParamRecordType << FromRecordType << From->getSourceRange(); 2976 2977 if (ICS.Standard.Second == ICK_Derived_To_Base) 2978 return PerformObjectMemberConversion(From, Qualifier, FoundDecl, Method); 2979 2980 if (!Context.hasSameType(From->getType(), DestType)) 2981 ImpCastExprToType(From, DestType, CastExpr::CK_NoOp, 2982 /*isLvalue=*/!From->getType()->isPointerType()); 2983 return false; 2984} 2985 2986/// TryContextuallyConvertToBool - Attempt to contextually convert the 2987/// expression From to bool (C++0x [conv]p3). 2988ImplicitConversionSequence Sema::TryContextuallyConvertToBool(Expr *From) { 2989 // FIXME: This is pretty broken. 2990 return TryImplicitConversion(From, Context.BoolTy, 2991 // FIXME: Are these flags correct? 2992 /*SuppressUserConversions=*/false, 2993 /*AllowExplicit=*/true, 2994 /*InOverloadResolution=*/false); 2995} 2996 2997/// PerformContextuallyConvertToBool - Perform a contextual conversion 2998/// of the expression From to bool (C++0x [conv]p3). 2999bool Sema::PerformContextuallyConvertToBool(Expr *&From) { 3000 ImplicitConversionSequence ICS = TryContextuallyConvertToBool(From); 3001 if (!ICS.isBad()) 3002 return PerformImplicitConversion(From, Context.BoolTy, ICS, AA_Converting); 3003 3004 if (!DiagnoseMultipleUserDefinedConversion(From, Context.BoolTy)) 3005 return Diag(From->getSourceRange().getBegin(), 3006 diag::err_typecheck_bool_condition) 3007 << From->getType() << From->getSourceRange(); 3008 return true; 3009} 3010 3011/// TryContextuallyConvertToObjCId - Attempt to contextually convert the 3012/// expression From to 'id'. 3013ImplicitConversionSequence Sema::TryContextuallyConvertToObjCId(Expr *From) { 3014 QualType Ty = Context.getObjCIdType(); 3015 return TryImplicitConversion(From, Ty, 3016 // FIXME: Are these flags correct? 3017 /*SuppressUserConversions=*/false, 3018 /*AllowExplicit=*/true, 3019 /*InOverloadResolution=*/false); 3020} 3021 3022/// PerformContextuallyConvertToObjCId - Perform a contextual conversion 3023/// of the expression From to 'id'. 3024bool Sema::PerformContextuallyConvertToObjCId(Expr *&From) { 3025 QualType Ty = Context.getObjCIdType(); 3026 ImplicitConversionSequence ICS = TryContextuallyConvertToObjCId(From); 3027 if (!ICS.isBad()) 3028 return PerformImplicitConversion(From, Ty, ICS, AA_Converting); 3029 return true; 3030} 3031 3032/// AddOverloadCandidate - Adds the given function to the set of 3033/// candidate functions, using the given function call arguments. If 3034/// @p SuppressUserConversions, then don't allow user-defined 3035/// conversions via constructors or conversion operators. 3036/// 3037/// \para PartialOverloading true if we are performing "partial" overloading 3038/// based on an incomplete set of function arguments. This feature is used by 3039/// code completion. 3040void 3041Sema::AddOverloadCandidate(FunctionDecl *Function, 3042 DeclAccessPair FoundDecl, 3043 Expr **Args, unsigned NumArgs, 3044 OverloadCandidateSet& CandidateSet, 3045 bool SuppressUserConversions, 3046 bool PartialOverloading) { 3047 const FunctionProtoType* Proto 3048 = dyn_cast<FunctionProtoType>(Function->getType()->getAs<FunctionType>()); 3049 assert(Proto && "Functions without a prototype cannot be overloaded"); 3050 assert(!Function->getDescribedFunctionTemplate() && 3051 "Use AddTemplateOverloadCandidate for function templates"); 3052 3053 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Function)) { 3054 if (!isa<CXXConstructorDecl>(Method)) { 3055 // If we get here, it's because we're calling a member function 3056 // that is named without a member access expression (e.g., 3057 // "this->f") that was either written explicitly or created 3058 // implicitly. This can happen with a qualified call to a member 3059 // function, e.g., X::f(). We use an empty type for the implied 3060 // object argument (C++ [over.call.func]p3), and the acting context 3061 // is irrelevant. 3062 AddMethodCandidate(Method, FoundDecl, Method->getParent(), 3063 QualType(), Args, NumArgs, CandidateSet, 3064 SuppressUserConversions); 3065 return; 3066 } 3067 // We treat a constructor like a non-member function, since its object 3068 // argument doesn't participate in overload resolution. 3069 } 3070 3071 if (!CandidateSet.isNewCandidate(Function)) 3072 return; 3073 3074 // Overload resolution is always an unevaluated context. 3075 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 3076 3077 if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(Function)){ 3078 // C++ [class.copy]p3: 3079 // A member function template is never instantiated to perform the copy 3080 // of a class object to an object of its class type. 3081 QualType ClassType = Context.getTypeDeclType(Constructor->getParent()); 3082 if (NumArgs == 1 && 3083 Constructor->isCopyConstructorLikeSpecialization() && 3084 (Context.hasSameUnqualifiedType(ClassType, Args[0]->getType()) || 3085 IsDerivedFrom(Args[0]->getType(), ClassType))) 3086 return; 3087 } 3088 3089 // Add this candidate 3090 CandidateSet.push_back(OverloadCandidate()); 3091 OverloadCandidate& Candidate = CandidateSet.back(); 3092 Candidate.FoundDecl = FoundDecl; 3093 Candidate.Function = Function; 3094 Candidate.Viable = true; 3095 Candidate.IsSurrogate = false; 3096 Candidate.IgnoreObjectArgument = false; 3097 3098 unsigned NumArgsInProto = Proto->getNumArgs(); 3099 3100 // (C++ 13.3.2p2): A candidate function having fewer than m 3101 // parameters is viable only if it has an ellipsis in its parameter 3102 // list (8.3.5). 3103 if ((NumArgs + (PartialOverloading && NumArgs)) > NumArgsInProto && 3104 !Proto->isVariadic()) { 3105 Candidate.Viable = false; 3106 Candidate.FailureKind = ovl_fail_too_many_arguments; 3107 return; 3108 } 3109 3110 // (C++ 13.3.2p2): A candidate function having more than m parameters 3111 // is viable only if the (m+1)st parameter has a default argument 3112 // (8.3.6). For the purposes of overload resolution, the 3113 // parameter list is truncated on the right, so that there are 3114 // exactly m parameters. 3115 unsigned MinRequiredArgs = Function->getMinRequiredArguments(); 3116 if (NumArgs < MinRequiredArgs && !PartialOverloading) { 3117 // Not enough arguments. 3118 Candidate.Viable = false; 3119 Candidate.FailureKind = ovl_fail_too_few_arguments; 3120 return; 3121 } 3122 3123 // Determine the implicit conversion sequences for each of the 3124 // arguments. 3125 Candidate.Conversions.resize(NumArgs); 3126 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 3127 if (ArgIdx < NumArgsInProto) { 3128 // (C++ 13.3.2p3): for F to be a viable function, there shall 3129 // exist for each argument an implicit conversion sequence 3130 // (13.3.3.1) that converts that argument to the corresponding 3131 // parameter of F. 3132 QualType ParamType = Proto->getArgType(ArgIdx); 3133 Candidate.Conversions[ArgIdx] 3134 = TryCopyInitialization(*this, Args[ArgIdx], ParamType, 3135 SuppressUserConversions, 3136 /*InOverloadResolution=*/true); 3137 if (Candidate.Conversions[ArgIdx].isBad()) { 3138 Candidate.Viable = false; 3139 Candidate.FailureKind = ovl_fail_bad_conversion; 3140 break; 3141 } 3142 } else { 3143 // (C++ 13.3.2p2): For the purposes of overload resolution, any 3144 // argument for which there is no corresponding parameter is 3145 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 3146 Candidate.Conversions[ArgIdx].setEllipsis(); 3147 } 3148 } 3149} 3150 3151/// \brief Add all of the function declarations in the given function set to 3152/// the overload canddiate set. 3153void Sema::AddFunctionCandidates(const UnresolvedSetImpl &Fns, 3154 Expr **Args, unsigned NumArgs, 3155 OverloadCandidateSet& CandidateSet, 3156 bool SuppressUserConversions) { 3157 for (UnresolvedSetIterator F = Fns.begin(), E = Fns.end(); F != E; ++F) { 3158 NamedDecl *D = F.getDecl()->getUnderlyingDecl(); 3159 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { 3160 if (isa<CXXMethodDecl>(FD) && !cast<CXXMethodDecl>(FD)->isStatic()) 3161 AddMethodCandidate(cast<CXXMethodDecl>(FD), F.getPair(), 3162 cast<CXXMethodDecl>(FD)->getParent(), 3163 Args[0]->getType(), Args + 1, NumArgs - 1, 3164 CandidateSet, SuppressUserConversions); 3165 else 3166 AddOverloadCandidate(FD, F.getPair(), Args, NumArgs, CandidateSet, 3167 SuppressUserConversions); 3168 } else { 3169 FunctionTemplateDecl *FunTmpl = cast<FunctionTemplateDecl>(D); 3170 if (isa<CXXMethodDecl>(FunTmpl->getTemplatedDecl()) && 3171 !cast<CXXMethodDecl>(FunTmpl->getTemplatedDecl())->isStatic()) 3172 AddMethodTemplateCandidate(FunTmpl, F.getPair(), 3173 cast<CXXRecordDecl>(FunTmpl->getDeclContext()), 3174 /*FIXME: explicit args */ 0, 3175 Args[0]->getType(), Args + 1, NumArgs - 1, 3176 CandidateSet, 3177 SuppressUserConversions); 3178 else 3179 AddTemplateOverloadCandidate(FunTmpl, F.getPair(), 3180 /*FIXME: explicit args */ 0, 3181 Args, NumArgs, CandidateSet, 3182 SuppressUserConversions); 3183 } 3184 } 3185} 3186 3187/// AddMethodCandidate - Adds a named decl (which is some kind of 3188/// method) as a method candidate to the given overload set. 3189void Sema::AddMethodCandidate(DeclAccessPair FoundDecl, 3190 QualType ObjectType, 3191 Expr **Args, unsigned NumArgs, 3192 OverloadCandidateSet& CandidateSet, 3193 bool SuppressUserConversions) { 3194 NamedDecl *Decl = FoundDecl.getDecl(); 3195 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(Decl->getDeclContext()); 3196 3197 if (isa<UsingShadowDecl>(Decl)) 3198 Decl = cast<UsingShadowDecl>(Decl)->getTargetDecl(); 3199 3200 if (FunctionTemplateDecl *TD = dyn_cast<FunctionTemplateDecl>(Decl)) { 3201 assert(isa<CXXMethodDecl>(TD->getTemplatedDecl()) && 3202 "Expected a member function template"); 3203 AddMethodTemplateCandidate(TD, FoundDecl, ActingContext, 3204 /*ExplicitArgs*/ 0, 3205 ObjectType, Args, NumArgs, 3206 CandidateSet, 3207 SuppressUserConversions); 3208 } else { 3209 AddMethodCandidate(cast<CXXMethodDecl>(Decl), FoundDecl, ActingContext, 3210 ObjectType, Args, NumArgs, 3211 CandidateSet, SuppressUserConversions); 3212 } 3213} 3214 3215/// AddMethodCandidate - Adds the given C++ member function to the set 3216/// of candidate functions, using the given function call arguments 3217/// and the object argument (@c Object). For example, in a call 3218/// @c o.f(a1,a2), @c Object will contain @c o and @c Args will contain 3219/// both @c a1 and @c a2. If @p SuppressUserConversions, then don't 3220/// allow user-defined conversions via constructors or conversion 3221/// operators. 3222void 3223Sema::AddMethodCandidate(CXXMethodDecl *Method, DeclAccessPair FoundDecl, 3224 CXXRecordDecl *ActingContext, QualType ObjectType, 3225 Expr **Args, unsigned NumArgs, 3226 OverloadCandidateSet& CandidateSet, 3227 bool SuppressUserConversions) { 3228 const FunctionProtoType* Proto 3229 = dyn_cast<FunctionProtoType>(Method->getType()->getAs<FunctionType>()); 3230 assert(Proto && "Methods without a prototype cannot be overloaded"); 3231 assert(!isa<CXXConstructorDecl>(Method) && 3232 "Use AddOverloadCandidate for constructors"); 3233 3234 if (!CandidateSet.isNewCandidate(Method)) 3235 return; 3236 3237 // Overload resolution is always an unevaluated context. 3238 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 3239 3240 // Add this candidate 3241 CandidateSet.push_back(OverloadCandidate()); 3242 OverloadCandidate& Candidate = CandidateSet.back(); 3243 Candidate.FoundDecl = FoundDecl; 3244 Candidate.Function = Method; 3245 Candidate.IsSurrogate = false; 3246 Candidate.IgnoreObjectArgument = false; 3247 3248 unsigned NumArgsInProto = Proto->getNumArgs(); 3249 3250 // (C++ 13.3.2p2): A candidate function having fewer than m 3251 // parameters is viable only if it has an ellipsis in its parameter 3252 // list (8.3.5). 3253 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 3254 Candidate.Viable = false; 3255 Candidate.FailureKind = ovl_fail_too_many_arguments; 3256 return; 3257 } 3258 3259 // (C++ 13.3.2p2): A candidate function having more than m parameters 3260 // is viable only if the (m+1)st parameter has a default argument 3261 // (8.3.6). For the purposes of overload resolution, the 3262 // parameter list is truncated on the right, so that there are 3263 // exactly m parameters. 3264 unsigned MinRequiredArgs = Method->getMinRequiredArguments(); 3265 if (NumArgs < MinRequiredArgs) { 3266 // Not enough arguments. 3267 Candidate.Viable = false; 3268 Candidate.FailureKind = ovl_fail_too_few_arguments; 3269 return; 3270 } 3271 3272 Candidate.Viable = true; 3273 Candidate.Conversions.resize(NumArgs + 1); 3274 3275 if (Method->isStatic() || ObjectType.isNull()) 3276 // The implicit object argument is ignored. 3277 Candidate.IgnoreObjectArgument = true; 3278 else { 3279 // Determine the implicit conversion sequence for the object 3280 // parameter. 3281 Candidate.Conversions[0] 3282 = TryObjectArgumentInitialization(ObjectType, Method, ActingContext); 3283 if (Candidate.Conversions[0].isBad()) { 3284 Candidate.Viable = false; 3285 Candidate.FailureKind = ovl_fail_bad_conversion; 3286 return; 3287 } 3288 } 3289 3290 // Determine the implicit conversion sequences for each of the 3291 // arguments. 3292 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 3293 if (ArgIdx < NumArgsInProto) { 3294 // (C++ 13.3.2p3): for F to be a viable function, there shall 3295 // exist for each argument an implicit conversion sequence 3296 // (13.3.3.1) that converts that argument to the corresponding 3297 // parameter of F. 3298 QualType ParamType = Proto->getArgType(ArgIdx); 3299 Candidate.Conversions[ArgIdx + 1] 3300 = TryCopyInitialization(*this, Args[ArgIdx], ParamType, 3301 SuppressUserConversions, 3302 /*InOverloadResolution=*/true); 3303 if (Candidate.Conversions[ArgIdx + 1].isBad()) { 3304 Candidate.Viable = false; 3305 Candidate.FailureKind = ovl_fail_bad_conversion; 3306 break; 3307 } 3308 } else { 3309 // (C++ 13.3.2p2): For the purposes of overload resolution, any 3310 // argument for which there is no corresponding parameter is 3311 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 3312 Candidate.Conversions[ArgIdx + 1].setEllipsis(); 3313 } 3314 } 3315} 3316 3317/// \brief Add a C++ member function template as a candidate to the candidate 3318/// set, using template argument deduction to produce an appropriate member 3319/// function template specialization. 3320void 3321Sema::AddMethodTemplateCandidate(FunctionTemplateDecl *MethodTmpl, 3322 DeclAccessPair FoundDecl, 3323 CXXRecordDecl *ActingContext, 3324 const TemplateArgumentListInfo *ExplicitTemplateArgs, 3325 QualType ObjectType, 3326 Expr **Args, unsigned NumArgs, 3327 OverloadCandidateSet& CandidateSet, 3328 bool SuppressUserConversions) { 3329 if (!CandidateSet.isNewCandidate(MethodTmpl)) 3330 return; 3331 3332 // C++ [over.match.funcs]p7: 3333 // In each case where a candidate is a function template, candidate 3334 // function template specializations are generated using template argument 3335 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 3336 // candidate functions in the usual way.113) A given name can refer to one 3337 // or more function templates and also to a set of overloaded non-template 3338 // functions. In such a case, the candidate functions generated from each 3339 // function template are combined with the set of non-template candidate 3340 // functions. 3341 TemplateDeductionInfo Info(Context, CandidateSet.getLocation()); 3342 FunctionDecl *Specialization = 0; 3343 if (TemplateDeductionResult Result 3344 = DeduceTemplateArguments(MethodTmpl, ExplicitTemplateArgs, 3345 Args, NumArgs, Specialization, Info)) { 3346 CandidateSet.push_back(OverloadCandidate()); 3347 OverloadCandidate &Candidate = CandidateSet.back(); 3348 Candidate.FoundDecl = FoundDecl; 3349 Candidate.Function = MethodTmpl->getTemplatedDecl(); 3350 Candidate.Viable = false; 3351 Candidate.FailureKind = ovl_fail_bad_deduction; 3352 Candidate.IsSurrogate = false; 3353 Candidate.IgnoreObjectArgument = false; 3354 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result, 3355 Info); 3356 return; 3357 } 3358 3359 // Add the function template specialization produced by template argument 3360 // deduction as a candidate. 3361 assert(Specialization && "Missing member function template specialization?"); 3362 assert(isa<CXXMethodDecl>(Specialization) && 3363 "Specialization is not a member function?"); 3364 AddMethodCandidate(cast<CXXMethodDecl>(Specialization), FoundDecl, 3365 ActingContext, ObjectType, Args, NumArgs, 3366 CandidateSet, SuppressUserConversions); 3367} 3368 3369/// \brief Add a C++ function template specialization as a candidate 3370/// in the candidate set, using template argument deduction to produce 3371/// an appropriate function template specialization. 3372void 3373Sema::AddTemplateOverloadCandidate(FunctionTemplateDecl *FunctionTemplate, 3374 DeclAccessPair FoundDecl, 3375 const TemplateArgumentListInfo *ExplicitTemplateArgs, 3376 Expr **Args, unsigned NumArgs, 3377 OverloadCandidateSet& CandidateSet, 3378 bool SuppressUserConversions) { 3379 if (!CandidateSet.isNewCandidate(FunctionTemplate)) 3380 return; 3381 3382 // C++ [over.match.funcs]p7: 3383 // In each case where a candidate is a function template, candidate 3384 // function template specializations are generated using template argument 3385 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 3386 // candidate functions in the usual way.113) A given name can refer to one 3387 // or more function templates and also to a set of overloaded non-template 3388 // functions. In such a case, the candidate functions generated from each 3389 // function template are combined with the set of non-template candidate 3390 // functions. 3391 TemplateDeductionInfo Info(Context, CandidateSet.getLocation()); 3392 FunctionDecl *Specialization = 0; 3393 if (TemplateDeductionResult Result 3394 = DeduceTemplateArguments(FunctionTemplate, ExplicitTemplateArgs, 3395 Args, NumArgs, Specialization, Info)) { 3396 CandidateSet.push_back(OverloadCandidate()); 3397 OverloadCandidate &Candidate = CandidateSet.back(); 3398 Candidate.FoundDecl = FoundDecl; 3399 Candidate.Function = FunctionTemplate->getTemplatedDecl(); 3400 Candidate.Viable = false; 3401 Candidate.FailureKind = ovl_fail_bad_deduction; 3402 Candidate.IsSurrogate = false; 3403 Candidate.IgnoreObjectArgument = false; 3404 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result, 3405 Info); 3406 return; 3407 } 3408 3409 // Add the function template specialization produced by template argument 3410 // deduction as a candidate. 3411 assert(Specialization && "Missing function template specialization?"); 3412 AddOverloadCandidate(Specialization, FoundDecl, Args, NumArgs, CandidateSet, 3413 SuppressUserConversions); 3414} 3415 3416/// AddConversionCandidate - Add a C++ conversion function as a 3417/// candidate in the candidate set (C++ [over.match.conv], 3418/// C++ [over.match.copy]). From is the expression we're converting from, 3419/// and ToType is the type that we're eventually trying to convert to 3420/// (which may or may not be the same type as the type that the 3421/// conversion function produces). 3422void 3423Sema::AddConversionCandidate(CXXConversionDecl *Conversion, 3424 DeclAccessPair FoundDecl, 3425 CXXRecordDecl *ActingContext, 3426 Expr *From, QualType ToType, 3427 OverloadCandidateSet& CandidateSet) { 3428 assert(!Conversion->getDescribedFunctionTemplate() && 3429 "Conversion function templates use AddTemplateConversionCandidate"); 3430 QualType ConvType = Conversion->getConversionType().getNonReferenceType(); 3431 if (!CandidateSet.isNewCandidate(Conversion)) 3432 return; 3433 3434 // Overload resolution is always an unevaluated context. 3435 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 3436 3437 // Add this candidate 3438 CandidateSet.push_back(OverloadCandidate()); 3439 OverloadCandidate& Candidate = CandidateSet.back(); 3440 Candidate.FoundDecl = FoundDecl; 3441 Candidate.Function = Conversion; 3442 Candidate.IsSurrogate = false; 3443 Candidate.IgnoreObjectArgument = false; 3444 Candidate.FinalConversion.setAsIdentityConversion(); 3445 Candidate.FinalConversion.setFromType(ConvType); 3446 Candidate.FinalConversion.setAllToTypes(ToType); 3447 3448 // Determine the implicit conversion sequence for the implicit 3449 // object parameter. 3450 Candidate.Viable = true; 3451 Candidate.Conversions.resize(1); 3452 Candidate.Conversions[0] 3453 = TryObjectArgumentInitialization(From->getType(), Conversion, 3454 ActingContext); 3455 // Conversion functions to a different type in the base class is visible in 3456 // the derived class. So, a derived to base conversion should not participate 3457 // in overload resolution. 3458 if (Candidate.Conversions[0].Standard.Second == ICK_Derived_To_Base) 3459 Candidate.Conversions[0].Standard.Second = ICK_Identity; 3460 if (Candidate.Conversions[0].isBad()) { 3461 Candidate.Viable = false; 3462 Candidate.FailureKind = ovl_fail_bad_conversion; 3463 return; 3464 } 3465 3466 // We won't go through a user-define type conversion function to convert a 3467 // derived to base as such conversions are given Conversion Rank. They only 3468 // go through a copy constructor. 13.3.3.1.2-p4 [over.ics.user] 3469 QualType FromCanon 3470 = Context.getCanonicalType(From->getType().getUnqualifiedType()); 3471 QualType ToCanon = Context.getCanonicalType(ToType).getUnqualifiedType(); 3472 if (FromCanon == ToCanon || IsDerivedFrom(FromCanon, ToCanon)) { 3473 Candidate.Viable = false; 3474 Candidate.FailureKind = ovl_fail_trivial_conversion; 3475 return; 3476 } 3477 3478 // To determine what the conversion from the result of calling the 3479 // conversion function to the type we're eventually trying to 3480 // convert to (ToType), we need to synthesize a call to the 3481 // conversion function and attempt copy initialization from it. This 3482 // makes sure that we get the right semantics with respect to 3483 // lvalues/rvalues and the type. Fortunately, we can allocate this 3484 // call on the stack and we don't need its arguments to be 3485 // well-formed. 3486 DeclRefExpr ConversionRef(Conversion, Conversion->getType(), 3487 From->getLocStart()); 3488 ImplicitCastExpr ConversionFn(Context.getPointerType(Conversion->getType()), 3489 CastExpr::CK_FunctionToPointerDecay, 3490 &ConversionRef, CXXBaseSpecifierArray(), false); 3491 3492 // Note that it is safe to allocate CallExpr on the stack here because 3493 // there are 0 arguments (i.e., nothing is allocated using ASTContext's 3494 // allocator). 3495 CallExpr Call(Context, &ConversionFn, 0, 0, 3496 Conversion->getConversionType().getNonReferenceType(), 3497 From->getLocStart()); 3498 ImplicitConversionSequence ICS = 3499 TryCopyInitialization(*this, &Call, ToType, 3500 /*SuppressUserConversions=*/true, 3501 /*InOverloadResolution=*/false); 3502 3503 switch (ICS.getKind()) { 3504 case ImplicitConversionSequence::StandardConversion: 3505 Candidate.FinalConversion = ICS.Standard; 3506 3507 // C++ [over.ics.user]p3: 3508 // If the user-defined conversion is specified by a specialization of a 3509 // conversion function template, the second standard conversion sequence 3510 // shall have exact match rank. 3511 if (Conversion->getPrimaryTemplate() && 3512 GetConversionRank(ICS.Standard.Second) != ICR_Exact_Match) { 3513 Candidate.Viable = false; 3514 Candidate.FailureKind = ovl_fail_final_conversion_not_exact; 3515 } 3516 3517 break; 3518 3519 case ImplicitConversionSequence::BadConversion: 3520 Candidate.Viable = false; 3521 Candidate.FailureKind = ovl_fail_bad_final_conversion; 3522 break; 3523 3524 default: 3525 assert(false && 3526 "Can only end up with a standard conversion sequence or failure"); 3527 } 3528} 3529 3530/// \brief Adds a conversion function template specialization 3531/// candidate to the overload set, using template argument deduction 3532/// to deduce the template arguments of the conversion function 3533/// template from the type that we are converting to (C++ 3534/// [temp.deduct.conv]). 3535void 3536Sema::AddTemplateConversionCandidate(FunctionTemplateDecl *FunctionTemplate, 3537 DeclAccessPair FoundDecl, 3538 CXXRecordDecl *ActingDC, 3539 Expr *From, QualType ToType, 3540 OverloadCandidateSet &CandidateSet) { 3541 assert(isa<CXXConversionDecl>(FunctionTemplate->getTemplatedDecl()) && 3542 "Only conversion function templates permitted here"); 3543 3544 if (!CandidateSet.isNewCandidate(FunctionTemplate)) 3545 return; 3546 3547 TemplateDeductionInfo Info(Context, CandidateSet.getLocation()); 3548 CXXConversionDecl *Specialization = 0; 3549 if (TemplateDeductionResult Result 3550 = DeduceTemplateArguments(FunctionTemplate, ToType, 3551 Specialization, Info)) { 3552 CandidateSet.push_back(OverloadCandidate()); 3553 OverloadCandidate &Candidate = CandidateSet.back(); 3554 Candidate.FoundDecl = FoundDecl; 3555 Candidate.Function = FunctionTemplate->getTemplatedDecl(); 3556 Candidate.Viable = false; 3557 Candidate.FailureKind = ovl_fail_bad_deduction; 3558 Candidate.IsSurrogate = false; 3559 Candidate.IgnoreObjectArgument = false; 3560 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result, 3561 Info); 3562 return; 3563 } 3564 3565 // Add the conversion function template specialization produced by 3566 // template argument deduction as a candidate. 3567 assert(Specialization && "Missing function template specialization?"); 3568 AddConversionCandidate(Specialization, FoundDecl, ActingDC, From, ToType, 3569 CandidateSet); 3570} 3571 3572/// AddSurrogateCandidate - Adds a "surrogate" candidate function that 3573/// converts the given @c Object to a function pointer via the 3574/// conversion function @c Conversion, and then attempts to call it 3575/// with the given arguments (C++ [over.call.object]p2-4). Proto is 3576/// the type of function that we'll eventually be calling. 3577void Sema::AddSurrogateCandidate(CXXConversionDecl *Conversion, 3578 DeclAccessPair FoundDecl, 3579 CXXRecordDecl *ActingContext, 3580 const FunctionProtoType *Proto, 3581 QualType ObjectType, 3582 Expr **Args, unsigned NumArgs, 3583 OverloadCandidateSet& CandidateSet) { 3584 if (!CandidateSet.isNewCandidate(Conversion)) 3585 return; 3586 3587 // Overload resolution is always an unevaluated context. 3588 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 3589 3590 CandidateSet.push_back(OverloadCandidate()); 3591 OverloadCandidate& Candidate = CandidateSet.back(); 3592 Candidate.FoundDecl = FoundDecl; 3593 Candidate.Function = 0; 3594 Candidate.Surrogate = Conversion; 3595 Candidate.Viable = true; 3596 Candidate.IsSurrogate = true; 3597 Candidate.IgnoreObjectArgument = false; 3598 Candidate.Conversions.resize(NumArgs + 1); 3599 3600 // Determine the implicit conversion sequence for the implicit 3601 // object parameter. 3602 ImplicitConversionSequence ObjectInit 3603 = TryObjectArgumentInitialization(ObjectType, Conversion, ActingContext); 3604 if (ObjectInit.isBad()) { 3605 Candidate.Viable = false; 3606 Candidate.FailureKind = ovl_fail_bad_conversion; 3607 Candidate.Conversions[0] = ObjectInit; 3608 return; 3609 } 3610 3611 // The first conversion is actually a user-defined conversion whose 3612 // first conversion is ObjectInit's standard conversion (which is 3613 // effectively a reference binding). Record it as such. 3614 Candidate.Conversions[0].setUserDefined(); 3615 Candidate.Conversions[0].UserDefined.Before = ObjectInit.Standard; 3616 Candidate.Conversions[0].UserDefined.EllipsisConversion = false; 3617 Candidate.Conversions[0].UserDefined.ConversionFunction = Conversion; 3618 Candidate.Conversions[0].UserDefined.After 3619 = Candidate.Conversions[0].UserDefined.Before; 3620 Candidate.Conversions[0].UserDefined.After.setAsIdentityConversion(); 3621 3622 // Find the 3623 unsigned NumArgsInProto = Proto->getNumArgs(); 3624 3625 // (C++ 13.3.2p2): A candidate function having fewer than m 3626 // parameters is viable only if it has an ellipsis in its parameter 3627 // list (8.3.5). 3628 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 3629 Candidate.Viable = false; 3630 Candidate.FailureKind = ovl_fail_too_many_arguments; 3631 return; 3632 } 3633 3634 // Function types don't have any default arguments, so just check if 3635 // we have enough arguments. 3636 if (NumArgs < NumArgsInProto) { 3637 // Not enough arguments. 3638 Candidate.Viable = false; 3639 Candidate.FailureKind = ovl_fail_too_few_arguments; 3640 return; 3641 } 3642 3643 // Determine the implicit conversion sequences for each of the 3644 // arguments. 3645 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 3646 if (ArgIdx < NumArgsInProto) { 3647 // (C++ 13.3.2p3): for F to be a viable function, there shall 3648 // exist for each argument an implicit conversion sequence 3649 // (13.3.3.1) that converts that argument to the corresponding 3650 // parameter of F. 3651 QualType ParamType = Proto->getArgType(ArgIdx); 3652 Candidate.Conversions[ArgIdx + 1] 3653 = TryCopyInitialization(*this, Args[ArgIdx], ParamType, 3654 /*SuppressUserConversions=*/false, 3655 /*InOverloadResolution=*/false); 3656 if (Candidate.Conversions[ArgIdx + 1].isBad()) { 3657 Candidate.Viable = false; 3658 Candidate.FailureKind = ovl_fail_bad_conversion; 3659 break; 3660 } 3661 } else { 3662 // (C++ 13.3.2p2): For the purposes of overload resolution, any 3663 // argument for which there is no corresponding parameter is 3664 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 3665 Candidate.Conversions[ArgIdx + 1].setEllipsis(); 3666 } 3667 } 3668} 3669 3670/// \brief Add overload candidates for overloaded operators that are 3671/// member functions. 3672/// 3673/// Add the overloaded operator candidates that are member functions 3674/// for the operator Op that was used in an operator expression such 3675/// as "x Op y". , Args/NumArgs provides the operator arguments, and 3676/// CandidateSet will store the added overload candidates. (C++ 3677/// [over.match.oper]). 3678void Sema::AddMemberOperatorCandidates(OverloadedOperatorKind Op, 3679 SourceLocation OpLoc, 3680 Expr **Args, unsigned NumArgs, 3681 OverloadCandidateSet& CandidateSet, 3682 SourceRange OpRange) { 3683 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 3684 3685 // C++ [over.match.oper]p3: 3686 // For a unary operator @ with an operand of a type whose 3687 // cv-unqualified version is T1, and for a binary operator @ with 3688 // a left operand of a type whose cv-unqualified version is T1 and 3689 // a right operand of a type whose cv-unqualified version is T2, 3690 // three sets of candidate functions, designated member 3691 // candidates, non-member candidates and built-in candidates, are 3692 // constructed as follows: 3693 QualType T1 = Args[0]->getType(); 3694 QualType T2; 3695 if (NumArgs > 1) 3696 T2 = Args[1]->getType(); 3697 3698 // -- If T1 is a class type, the set of member candidates is the 3699 // result of the qualified lookup of T1::operator@ 3700 // (13.3.1.1.1); otherwise, the set of member candidates is 3701 // empty. 3702 if (const RecordType *T1Rec = T1->getAs<RecordType>()) { 3703 // Complete the type if it can be completed. Otherwise, we're done. 3704 if (RequireCompleteType(OpLoc, T1, PDiag())) 3705 return; 3706 3707 LookupResult Operators(*this, OpName, OpLoc, LookupOrdinaryName); 3708 LookupQualifiedName(Operators, T1Rec->getDecl()); 3709 Operators.suppressDiagnostics(); 3710 3711 for (LookupResult::iterator Oper = Operators.begin(), 3712 OperEnd = Operators.end(); 3713 Oper != OperEnd; 3714 ++Oper) 3715 AddMethodCandidate(Oper.getPair(), Args[0]->getType(), 3716 Args + 1, NumArgs - 1, CandidateSet, 3717 /* SuppressUserConversions = */ false); 3718 } 3719} 3720 3721/// AddBuiltinCandidate - Add a candidate for a built-in 3722/// operator. ResultTy and ParamTys are the result and parameter types 3723/// of the built-in candidate, respectively. Args and NumArgs are the 3724/// arguments being passed to the candidate. IsAssignmentOperator 3725/// should be true when this built-in candidate is an assignment 3726/// operator. NumContextualBoolArguments is the number of arguments 3727/// (at the beginning of the argument list) that will be contextually 3728/// converted to bool. 3729void Sema::AddBuiltinCandidate(QualType ResultTy, QualType *ParamTys, 3730 Expr **Args, unsigned NumArgs, 3731 OverloadCandidateSet& CandidateSet, 3732 bool IsAssignmentOperator, 3733 unsigned NumContextualBoolArguments) { 3734 // Overload resolution is always an unevaluated context. 3735 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 3736 3737 // Add this candidate 3738 CandidateSet.push_back(OverloadCandidate()); 3739 OverloadCandidate& Candidate = CandidateSet.back(); 3740 Candidate.FoundDecl = DeclAccessPair::make(0, AS_none); 3741 Candidate.Function = 0; 3742 Candidate.IsSurrogate = false; 3743 Candidate.IgnoreObjectArgument = false; 3744 Candidate.BuiltinTypes.ResultTy = ResultTy; 3745 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 3746 Candidate.BuiltinTypes.ParamTypes[ArgIdx] = ParamTys[ArgIdx]; 3747 3748 // Determine the implicit conversion sequences for each of the 3749 // arguments. 3750 Candidate.Viable = true; 3751 Candidate.Conversions.resize(NumArgs); 3752 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 3753 // C++ [over.match.oper]p4: 3754 // For the built-in assignment operators, conversions of the 3755 // left operand are restricted as follows: 3756 // -- no temporaries are introduced to hold the left operand, and 3757 // -- no user-defined conversions are applied to the left 3758 // operand to achieve a type match with the left-most 3759 // parameter of a built-in candidate. 3760 // 3761 // We block these conversions by turning off user-defined 3762 // conversions, since that is the only way that initialization of 3763 // a reference to a non-class type can occur from something that 3764 // is not of the same type. 3765 if (ArgIdx < NumContextualBoolArguments) { 3766 assert(ParamTys[ArgIdx] == Context.BoolTy && 3767 "Contextual conversion to bool requires bool type"); 3768 Candidate.Conversions[ArgIdx] = TryContextuallyConvertToBool(Args[ArgIdx]); 3769 } else { 3770 Candidate.Conversions[ArgIdx] 3771 = TryCopyInitialization(*this, Args[ArgIdx], ParamTys[ArgIdx], 3772 ArgIdx == 0 && IsAssignmentOperator, 3773 /*InOverloadResolution=*/false); 3774 } 3775 if (Candidate.Conversions[ArgIdx].isBad()) { 3776 Candidate.Viable = false; 3777 Candidate.FailureKind = ovl_fail_bad_conversion; 3778 break; 3779 } 3780 } 3781} 3782 3783/// BuiltinCandidateTypeSet - A set of types that will be used for the 3784/// candidate operator functions for built-in operators (C++ 3785/// [over.built]). The types are separated into pointer types and 3786/// enumeration types. 3787class BuiltinCandidateTypeSet { 3788 /// TypeSet - A set of types. 3789 typedef llvm::SmallPtrSet<QualType, 8> TypeSet; 3790 3791 /// PointerTypes - The set of pointer types that will be used in the 3792 /// built-in candidates. 3793 TypeSet PointerTypes; 3794 3795 /// MemberPointerTypes - The set of member pointer types that will be 3796 /// used in the built-in candidates. 3797 TypeSet MemberPointerTypes; 3798 3799 /// EnumerationTypes - The set of enumeration types that will be 3800 /// used in the built-in candidates. 3801 TypeSet EnumerationTypes; 3802 3803 /// \brief The set of vector types that will be used in the built-in 3804 /// candidates. 3805 TypeSet VectorTypes; 3806 3807 /// Sema - The semantic analysis instance where we are building the 3808 /// candidate type set. 3809 Sema &SemaRef; 3810 3811 /// Context - The AST context in which we will build the type sets. 3812 ASTContext &Context; 3813 3814 bool AddPointerWithMoreQualifiedTypeVariants(QualType Ty, 3815 const Qualifiers &VisibleQuals); 3816 bool AddMemberPointerWithMoreQualifiedTypeVariants(QualType Ty); 3817 3818public: 3819 /// iterator - Iterates through the types that are part of the set. 3820 typedef TypeSet::iterator iterator; 3821 3822 BuiltinCandidateTypeSet(Sema &SemaRef) 3823 : SemaRef(SemaRef), Context(SemaRef.Context) { } 3824 3825 void AddTypesConvertedFrom(QualType Ty, 3826 SourceLocation Loc, 3827 bool AllowUserConversions, 3828 bool AllowExplicitConversions, 3829 const Qualifiers &VisibleTypeConversionsQuals); 3830 3831 /// pointer_begin - First pointer type found; 3832 iterator pointer_begin() { return PointerTypes.begin(); } 3833 3834 /// pointer_end - Past the last pointer type found; 3835 iterator pointer_end() { return PointerTypes.end(); } 3836 3837 /// member_pointer_begin - First member pointer type found; 3838 iterator member_pointer_begin() { return MemberPointerTypes.begin(); } 3839 3840 /// member_pointer_end - Past the last member pointer type found; 3841 iterator member_pointer_end() { return MemberPointerTypes.end(); } 3842 3843 /// enumeration_begin - First enumeration type found; 3844 iterator enumeration_begin() { return EnumerationTypes.begin(); } 3845 3846 /// enumeration_end - Past the last enumeration type found; 3847 iterator enumeration_end() { return EnumerationTypes.end(); } 3848 3849 iterator vector_begin() { return VectorTypes.begin(); } 3850 iterator vector_end() { return VectorTypes.end(); } 3851}; 3852 3853/// AddPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty to 3854/// the set of pointer types along with any more-qualified variants of 3855/// that type. For example, if @p Ty is "int const *", this routine 3856/// will add "int const *", "int const volatile *", "int const 3857/// restrict *", and "int const volatile restrict *" to the set of 3858/// pointer types. Returns true if the add of @p Ty itself succeeded, 3859/// false otherwise. 3860/// 3861/// FIXME: what to do about extended qualifiers? 3862bool 3863BuiltinCandidateTypeSet::AddPointerWithMoreQualifiedTypeVariants(QualType Ty, 3864 const Qualifiers &VisibleQuals) { 3865 3866 // Insert this type. 3867 if (!PointerTypes.insert(Ty)) 3868 return false; 3869 3870 const PointerType *PointerTy = Ty->getAs<PointerType>(); 3871 assert(PointerTy && "type was not a pointer type!"); 3872 3873 QualType PointeeTy = PointerTy->getPointeeType(); 3874 // Don't add qualified variants of arrays. For one, they're not allowed 3875 // (the qualifier would sink to the element type), and for another, the 3876 // only overload situation where it matters is subscript or pointer +- int, 3877 // and those shouldn't have qualifier variants anyway. 3878 if (PointeeTy->isArrayType()) 3879 return true; 3880 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 3881 if (const ConstantArrayType *Array =Context.getAsConstantArrayType(PointeeTy)) 3882 BaseCVR = Array->getElementType().getCVRQualifiers(); 3883 bool hasVolatile = VisibleQuals.hasVolatile(); 3884 bool hasRestrict = VisibleQuals.hasRestrict(); 3885 3886 // Iterate through all strict supersets of BaseCVR. 3887 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 3888 if ((CVR | BaseCVR) != CVR) continue; 3889 // Skip over Volatile/Restrict if no Volatile/Restrict found anywhere 3890 // in the types. 3891 if ((CVR & Qualifiers::Volatile) && !hasVolatile) continue; 3892 if ((CVR & Qualifiers::Restrict) && !hasRestrict) continue; 3893 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 3894 PointerTypes.insert(Context.getPointerType(QPointeeTy)); 3895 } 3896 3897 return true; 3898} 3899 3900/// AddMemberPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty 3901/// to the set of pointer types along with any more-qualified variants of 3902/// that type. For example, if @p Ty is "int const *", this routine 3903/// will add "int const *", "int const volatile *", "int const 3904/// restrict *", and "int const volatile restrict *" to the set of 3905/// pointer types. Returns true if the add of @p Ty itself succeeded, 3906/// false otherwise. 3907/// 3908/// FIXME: what to do about extended qualifiers? 3909bool 3910BuiltinCandidateTypeSet::AddMemberPointerWithMoreQualifiedTypeVariants( 3911 QualType Ty) { 3912 // Insert this type. 3913 if (!MemberPointerTypes.insert(Ty)) 3914 return false; 3915 3916 const MemberPointerType *PointerTy = Ty->getAs<MemberPointerType>(); 3917 assert(PointerTy && "type was not a member pointer type!"); 3918 3919 QualType PointeeTy = PointerTy->getPointeeType(); 3920 // Don't add qualified variants of arrays. For one, they're not allowed 3921 // (the qualifier would sink to the element type), and for another, the 3922 // only overload situation where it matters is subscript or pointer +- int, 3923 // and those shouldn't have qualifier variants anyway. 3924 if (PointeeTy->isArrayType()) 3925 return true; 3926 const Type *ClassTy = PointerTy->getClass(); 3927 3928 // Iterate through all strict supersets of the pointee type's CVR 3929 // qualifiers. 3930 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 3931 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 3932 if ((CVR | BaseCVR) != CVR) continue; 3933 3934 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 3935 MemberPointerTypes.insert(Context.getMemberPointerType(QPointeeTy, ClassTy)); 3936 } 3937 3938 return true; 3939} 3940 3941/// AddTypesConvertedFrom - Add each of the types to which the type @p 3942/// Ty can be implicit converted to the given set of @p Types. We're 3943/// primarily interested in pointer types and enumeration types. We also 3944/// take member pointer types, for the conditional operator. 3945/// AllowUserConversions is true if we should look at the conversion 3946/// functions of a class type, and AllowExplicitConversions if we 3947/// should also include the explicit conversion functions of a class 3948/// type. 3949void 3950BuiltinCandidateTypeSet::AddTypesConvertedFrom(QualType Ty, 3951 SourceLocation Loc, 3952 bool AllowUserConversions, 3953 bool AllowExplicitConversions, 3954 const Qualifiers &VisibleQuals) { 3955 // Only deal with canonical types. 3956 Ty = Context.getCanonicalType(Ty); 3957 3958 // Look through reference types; they aren't part of the type of an 3959 // expression for the purposes of conversions. 3960 if (const ReferenceType *RefTy = Ty->getAs<ReferenceType>()) 3961 Ty = RefTy->getPointeeType(); 3962 3963 // We don't care about qualifiers on the type. 3964 Ty = Ty.getLocalUnqualifiedType(); 3965 3966 // If we're dealing with an array type, decay to the pointer. 3967 if (Ty->isArrayType()) 3968 Ty = SemaRef.Context.getArrayDecayedType(Ty); 3969 3970 if (const PointerType *PointerTy = Ty->getAs<PointerType>()) { 3971 QualType PointeeTy = PointerTy->getPointeeType(); 3972 3973 // Insert our type, and its more-qualified variants, into the set 3974 // of types. 3975 if (!AddPointerWithMoreQualifiedTypeVariants(Ty, VisibleQuals)) 3976 return; 3977 } else if (Ty->isMemberPointerType()) { 3978 // Member pointers are far easier, since the pointee can't be converted. 3979 if (!AddMemberPointerWithMoreQualifiedTypeVariants(Ty)) 3980 return; 3981 } else if (Ty->isEnumeralType()) { 3982 EnumerationTypes.insert(Ty); 3983 } else if (Ty->isVectorType()) { 3984 VectorTypes.insert(Ty); 3985 } else if (AllowUserConversions) { 3986 if (const RecordType *TyRec = Ty->getAs<RecordType>()) { 3987 if (SemaRef.RequireCompleteType(Loc, Ty, 0)) { 3988 // No conversion functions in incomplete types. 3989 return; 3990 } 3991 3992 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 3993 const UnresolvedSetImpl *Conversions 3994 = ClassDecl->getVisibleConversionFunctions(); 3995 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 3996 E = Conversions->end(); I != E; ++I) { 3997 NamedDecl *D = I.getDecl(); 3998 if (isa<UsingShadowDecl>(D)) 3999 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 4000 4001 // Skip conversion function templates; they don't tell us anything 4002 // about which builtin types we can convert to. 4003 if (isa<FunctionTemplateDecl>(D)) 4004 continue; 4005 4006 CXXConversionDecl *Conv = cast<CXXConversionDecl>(D); 4007 if (AllowExplicitConversions || !Conv->isExplicit()) { 4008 AddTypesConvertedFrom(Conv->getConversionType(), Loc, false, false, 4009 VisibleQuals); 4010 } 4011 } 4012 } 4013 } 4014} 4015 4016/// \brief Helper function for AddBuiltinOperatorCandidates() that adds 4017/// the volatile- and non-volatile-qualified assignment operators for the 4018/// given type to the candidate set. 4019static void AddBuiltinAssignmentOperatorCandidates(Sema &S, 4020 QualType T, 4021 Expr **Args, 4022 unsigned NumArgs, 4023 OverloadCandidateSet &CandidateSet) { 4024 QualType ParamTypes[2]; 4025 4026 // T& operator=(T&, T) 4027 ParamTypes[0] = S.Context.getLValueReferenceType(T); 4028 ParamTypes[1] = T; 4029 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4030 /*IsAssignmentOperator=*/true); 4031 4032 if (!S.Context.getCanonicalType(T).isVolatileQualified()) { 4033 // volatile T& operator=(volatile T&, T) 4034 ParamTypes[0] 4035 = S.Context.getLValueReferenceType(S.Context.getVolatileType(T)); 4036 ParamTypes[1] = T; 4037 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4038 /*IsAssignmentOperator=*/true); 4039 } 4040} 4041 4042/// CollectVRQualifiers - This routine returns Volatile/Restrict qualifiers, 4043/// if any, found in visible type conversion functions found in ArgExpr's type. 4044static Qualifiers CollectVRQualifiers(ASTContext &Context, Expr* ArgExpr) { 4045 Qualifiers VRQuals; 4046 const RecordType *TyRec; 4047 if (const MemberPointerType *RHSMPType = 4048 ArgExpr->getType()->getAs<MemberPointerType>()) 4049 TyRec = RHSMPType->getClass()->getAs<RecordType>(); 4050 else 4051 TyRec = ArgExpr->getType()->getAs<RecordType>(); 4052 if (!TyRec) { 4053 // Just to be safe, assume the worst case. 4054 VRQuals.addVolatile(); 4055 VRQuals.addRestrict(); 4056 return VRQuals; 4057 } 4058 4059 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 4060 if (!ClassDecl->hasDefinition()) 4061 return VRQuals; 4062 4063 const UnresolvedSetImpl *Conversions = 4064 ClassDecl->getVisibleConversionFunctions(); 4065 4066 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 4067 E = Conversions->end(); I != E; ++I) { 4068 NamedDecl *D = I.getDecl(); 4069 if (isa<UsingShadowDecl>(D)) 4070 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 4071 if (CXXConversionDecl *Conv = dyn_cast<CXXConversionDecl>(D)) { 4072 QualType CanTy = Context.getCanonicalType(Conv->getConversionType()); 4073 if (const ReferenceType *ResTypeRef = CanTy->getAs<ReferenceType>()) 4074 CanTy = ResTypeRef->getPointeeType(); 4075 // Need to go down the pointer/mempointer chain and add qualifiers 4076 // as see them. 4077 bool done = false; 4078 while (!done) { 4079 if (const PointerType *ResTypePtr = CanTy->getAs<PointerType>()) 4080 CanTy = ResTypePtr->getPointeeType(); 4081 else if (const MemberPointerType *ResTypeMPtr = 4082 CanTy->getAs<MemberPointerType>()) 4083 CanTy = ResTypeMPtr->getPointeeType(); 4084 else 4085 done = true; 4086 if (CanTy.isVolatileQualified()) 4087 VRQuals.addVolatile(); 4088 if (CanTy.isRestrictQualified()) 4089 VRQuals.addRestrict(); 4090 if (VRQuals.hasRestrict() && VRQuals.hasVolatile()) 4091 return VRQuals; 4092 } 4093 } 4094 } 4095 return VRQuals; 4096} 4097 4098/// AddBuiltinOperatorCandidates - Add the appropriate built-in 4099/// operator overloads to the candidate set (C++ [over.built]), based 4100/// on the operator @p Op and the arguments given. For example, if the 4101/// operator is a binary '+', this routine might add "int 4102/// operator+(int, int)" to cover integer addition. 4103void 4104Sema::AddBuiltinOperatorCandidates(OverloadedOperatorKind Op, 4105 SourceLocation OpLoc, 4106 Expr **Args, unsigned NumArgs, 4107 OverloadCandidateSet& CandidateSet) { 4108 // The set of "promoted arithmetic types", which are the arithmetic 4109 // types are that preserved by promotion (C++ [over.built]p2). Note 4110 // that the first few of these types are the promoted integral 4111 // types; these types need to be first. 4112 // FIXME: What about complex? 4113 const unsigned FirstIntegralType = 0; 4114 const unsigned LastIntegralType = 13; 4115 const unsigned FirstPromotedIntegralType = 7, 4116 LastPromotedIntegralType = 13; 4117 const unsigned FirstPromotedArithmeticType = 7, 4118 LastPromotedArithmeticType = 16; 4119 const unsigned NumArithmeticTypes = 16; 4120 QualType ArithmeticTypes[NumArithmeticTypes] = { 4121 Context.BoolTy, Context.CharTy, Context.WCharTy, 4122// FIXME: Context.Char16Ty, Context.Char32Ty, 4123 Context.SignedCharTy, Context.ShortTy, 4124 Context.UnsignedCharTy, Context.UnsignedShortTy, 4125 Context.IntTy, Context.LongTy, Context.LongLongTy, 4126 Context.UnsignedIntTy, Context.UnsignedLongTy, Context.UnsignedLongLongTy, 4127 Context.FloatTy, Context.DoubleTy, Context.LongDoubleTy 4128 }; 4129 assert(ArithmeticTypes[FirstPromotedIntegralType] == Context.IntTy && 4130 "Invalid first promoted integral type"); 4131 assert(ArithmeticTypes[LastPromotedIntegralType - 1] 4132 == Context.UnsignedLongLongTy && 4133 "Invalid last promoted integral type"); 4134 assert(ArithmeticTypes[FirstPromotedArithmeticType] == Context.IntTy && 4135 "Invalid first promoted arithmetic type"); 4136 assert(ArithmeticTypes[LastPromotedArithmeticType - 1] 4137 == Context.LongDoubleTy && 4138 "Invalid last promoted arithmetic type"); 4139 4140 // Find all of the types that the arguments can convert to, but only 4141 // if the operator we're looking at has built-in operator candidates 4142 // that make use of these types. 4143 Qualifiers VisibleTypeConversionsQuals; 4144 VisibleTypeConversionsQuals.addConst(); 4145 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 4146 VisibleTypeConversionsQuals += CollectVRQualifiers(Context, Args[ArgIdx]); 4147 4148 BuiltinCandidateTypeSet CandidateTypes(*this); 4149 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 4150 CandidateTypes.AddTypesConvertedFrom(Args[ArgIdx]->getType(), 4151 OpLoc, 4152 true, 4153 (Op == OO_Exclaim || 4154 Op == OO_AmpAmp || 4155 Op == OO_PipePipe), 4156 VisibleTypeConversionsQuals); 4157 4158 bool isComparison = false; 4159 switch (Op) { 4160 case OO_None: 4161 case NUM_OVERLOADED_OPERATORS: 4162 assert(false && "Expected an overloaded operator"); 4163 break; 4164 4165 case OO_Star: // '*' is either unary or binary 4166 if (NumArgs == 1) 4167 goto UnaryStar; 4168 else 4169 goto BinaryStar; 4170 break; 4171 4172 case OO_Plus: // '+' is either unary or binary 4173 if (NumArgs == 1) 4174 goto UnaryPlus; 4175 else 4176 goto BinaryPlus; 4177 break; 4178 4179 case OO_Minus: // '-' is either unary or binary 4180 if (NumArgs == 1) 4181 goto UnaryMinus; 4182 else 4183 goto BinaryMinus; 4184 break; 4185 4186 case OO_Amp: // '&' is either unary or binary 4187 if (NumArgs == 1) 4188 goto UnaryAmp; 4189 else 4190 goto BinaryAmp; 4191 4192 case OO_PlusPlus: 4193 case OO_MinusMinus: 4194 // C++ [over.built]p3: 4195 // 4196 // For every pair (T, VQ), where T is an arithmetic type, and VQ 4197 // is either volatile or empty, there exist candidate operator 4198 // functions of the form 4199 // 4200 // VQ T& operator++(VQ T&); 4201 // T operator++(VQ T&, int); 4202 // 4203 // C++ [over.built]p4: 4204 // 4205 // For every pair (T, VQ), where T is an arithmetic type other 4206 // than bool, and VQ is either volatile or empty, there exist 4207 // candidate operator functions of the form 4208 // 4209 // VQ T& operator--(VQ T&); 4210 // T operator--(VQ T&, int); 4211 for (unsigned Arith = (Op == OO_PlusPlus? 0 : 1); 4212 Arith < NumArithmeticTypes; ++Arith) { 4213 QualType ArithTy = ArithmeticTypes[Arith]; 4214 QualType ParamTypes[2] 4215 = { Context.getLValueReferenceType(ArithTy), Context.IntTy }; 4216 4217 // Non-volatile version. 4218 if (NumArgs == 1) 4219 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 4220 else 4221 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 4222 // heuristic to reduce number of builtin candidates in the set. 4223 // Add volatile version only if there are conversions to a volatile type. 4224 if (VisibleTypeConversionsQuals.hasVolatile()) { 4225 // Volatile version 4226 ParamTypes[0] 4227 = Context.getLValueReferenceType(Context.getVolatileType(ArithTy)); 4228 if (NumArgs == 1) 4229 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 4230 else 4231 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 4232 } 4233 } 4234 4235 // C++ [over.built]p5: 4236 // 4237 // For every pair (T, VQ), where T is a cv-qualified or 4238 // cv-unqualified object type, and VQ is either volatile or 4239 // empty, there exist candidate operator functions of the form 4240 // 4241 // T*VQ& operator++(T*VQ&); 4242 // T*VQ& operator--(T*VQ&); 4243 // T* operator++(T*VQ&, int); 4244 // T* operator--(T*VQ&, int); 4245 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 4246 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4247 // Skip pointer types that aren't pointers to object types. 4248 if (!(*Ptr)->getAs<PointerType>()->getPointeeType()->isObjectType()) 4249 continue; 4250 4251 QualType ParamTypes[2] = { 4252 Context.getLValueReferenceType(*Ptr), Context.IntTy 4253 }; 4254 4255 // Without volatile 4256 if (NumArgs == 1) 4257 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 4258 else 4259 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 4260 4261 if (!Context.getCanonicalType(*Ptr).isVolatileQualified() && 4262 VisibleTypeConversionsQuals.hasVolatile()) { 4263 // With volatile 4264 ParamTypes[0] 4265 = Context.getLValueReferenceType(Context.getVolatileType(*Ptr)); 4266 if (NumArgs == 1) 4267 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 4268 else 4269 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 4270 } 4271 } 4272 break; 4273 4274 UnaryStar: 4275 // C++ [over.built]p6: 4276 // For every cv-qualified or cv-unqualified object type T, there 4277 // exist candidate operator functions of the form 4278 // 4279 // T& operator*(T*); 4280 // 4281 // C++ [over.built]p7: 4282 // For every function type T, there exist candidate operator 4283 // functions of the form 4284 // T& operator*(T*); 4285 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 4286 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4287 QualType ParamTy = *Ptr; 4288 QualType PointeeTy = ParamTy->getAs<PointerType>()->getPointeeType(); 4289 AddBuiltinCandidate(Context.getLValueReferenceType(PointeeTy), 4290 &ParamTy, Args, 1, CandidateSet); 4291 } 4292 break; 4293 4294 UnaryPlus: 4295 // C++ [over.built]p8: 4296 // For every type T, there exist candidate operator functions of 4297 // the form 4298 // 4299 // T* operator+(T*); 4300 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 4301 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4302 QualType ParamTy = *Ptr; 4303 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet); 4304 } 4305 4306 // Fall through 4307 4308 UnaryMinus: 4309 // C++ [over.built]p9: 4310 // For every promoted arithmetic type T, there exist candidate 4311 // operator functions of the form 4312 // 4313 // T operator+(T); 4314 // T operator-(T); 4315 for (unsigned Arith = FirstPromotedArithmeticType; 4316 Arith < LastPromotedArithmeticType; ++Arith) { 4317 QualType ArithTy = ArithmeticTypes[Arith]; 4318 AddBuiltinCandidate(ArithTy, &ArithTy, Args, 1, CandidateSet); 4319 } 4320 4321 // Extension: We also add these operators for vector types. 4322 for (BuiltinCandidateTypeSet::iterator Vec = CandidateTypes.vector_begin(), 4323 VecEnd = CandidateTypes.vector_end(); 4324 Vec != VecEnd; ++Vec) { 4325 QualType VecTy = *Vec; 4326 AddBuiltinCandidate(VecTy, &VecTy, Args, 1, CandidateSet); 4327 } 4328 break; 4329 4330 case OO_Tilde: 4331 // C++ [over.built]p10: 4332 // For every promoted integral type T, there exist candidate 4333 // operator functions of the form 4334 // 4335 // T operator~(T); 4336 for (unsigned Int = FirstPromotedIntegralType; 4337 Int < LastPromotedIntegralType; ++Int) { 4338 QualType IntTy = ArithmeticTypes[Int]; 4339 AddBuiltinCandidate(IntTy, &IntTy, Args, 1, CandidateSet); 4340 } 4341 4342 // Extension: We also add this operator for vector types. 4343 for (BuiltinCandidateTypeSet::iterator Vec = CandidateTypes.vector_begin(), 4344 VecEnd = CandidateTypes.vector_end(); 4345 Vec != VecEnd; ++Vec) { 4346 QualType VecTy = *Vec; 4347 AddBuiltinCandidate(VecTy, &VecTy, Args, 1, CandidateSet); 4348 } 4349 break; 4350 4351 case OO_New: 4352 case OO_Delete: 4353 case OO_Array_New: 4354 case OO_Array_Delete: 4355 case OO_Call: 4356 assert(false && "Special operators don't use AddBuiltinOperatorCandidates"); 4357 break; 4358 4359 case OO_Comma: 4360 UnaryAmp: 4361 case OO_Arrow: 4362 // C++ [over.match.oper]p3: 4363 // -- For the operator ',', the unary operator '&', or the 4364 // operator '->', the built-in candidates set is empty. 4365 break; 4366 4367 case OO_EqualEqual: 4368 case OO_ExclaimEqual: 4369 // C++ [over.match.oper]p16: 4370 // For every pointer to member type T, there exist candidate operator 4371 // functions of the form 4372 // 4373 // bool operator==(T,T); 4374 // bool operator!=(T,T); 4375 for (BuiltinCandidateTypeSet::iterator 4376 MemPtr = CandidateTypes.member_pointer_begin(), 4377 MemPtrEnd = CandidateTypes.member_pointer_end(); 4378 MemPtr != MemPtrEnd; 4379 ++MemPtr) { 4380 QualType ParamTypes[2] = { *MemPtr, *MemPtr }; 4381 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 4382 } 4383 4384 // Fall through 4385 4386 case OO_Less: 4387 case OO_Greater: 4388 case OO_LessEqual: 4389 case OO_GreaterEqual: 4390 // C++ [over.built]p15: 4391 // 4392 // For every pointer or enumeration type T, there exist 4393 // candidate operator functions of the form 4394 // 4395 // bool operator<(T, T); 4396 // bool operator>(T, T); 4397 // bool operator<=(T, T); 4398 // bool operator>=(T, T); 4399 // bool operator==(T, T); 4400 // bool operator!=(T, T); 4401 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 4402 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4403 QualType ParamTypes[2] = { *Ptr, *Ptr }; 4404 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 4405 } 4406 for (BuiltinCandidateTypeSet::iterator Enum 4407 = CandidateTypes.enumeration_begin(); 4408 Enum != CandidateTypes.enumeration_end(); ++Enum) { 4409 QualType ParamTypes[2] = { *Enum, *Enum }; 4410 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 4411 } 4412 4413 // Fall through. 4414 isComparison = true; 4415 4416 BinaryPlus: 4417 BinaryMinus: 4418 if (!isComparison) { 4419 // We didn't fall through, so we must have OO_Plus or OO_Minus. 4420 4421 // C++ [over.built]p13: 4422 // 4423 // For every cv-qualified or cv-unqualified object type T 4424 // there exist candidate operator functions of the form 4425 // 4426 // T* operator+(T*, ptrdiff_t); 4427 // T& operator[](T*, ptrdiff_t); [BELOW] 4428 // T* operator-(T*, ptrdiff_t); 4429 // T* operator+(ptrdiff_t, T*); 4430 // T& operator[](ptrdiff_t, T*); [BELOW] 4431 // 4432 // C++ [over.built]p14: 4433 // 4434 // For every T, where T is a pointer to object type, there 4435 // exist candidate operator functions of the form 4436 // 4437 // ptrdiff_t operator-(T, T); 4438 for (BuiltinCandidateTypeSet::iterator Ptr 4439 = CandidateTypes.pointer_begin(); 4440 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4441 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 4442 4443 // operator+(T*, ptrdiff_t) or operator-(T*, ptrdiff_t) 4444 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 4445 4446 if (Op == OO_Plus) { 4447 // T* operator+(ptrdiff_t, T*); 4448 ParamTypes[0] = ParamTypes[1]; 4449 ParamTypes[1] = *Ptr; 4450 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 4451 } else { 4452 // ptrdiff_t operator-(T, T); 4453 ParamTypes[1] = *Ptr; 4454 AddBuiltinCandidate(Context.getPointerDiffType(), ParamTypes, 4455 Args, 2, CandidateSet); 4456 } 4457 } 4458 } 4459 // Fall through 4460 4461 case OO_Slash: 4462 BinaryStar: 4463 Conditional: 4464 // C++ [over.built]p12: 4465 // 4466 // For every pair of promoted arithmetic types L and R, there 4467 // exist candidate operator functions of the form 4468 // 4469 // LR operator*(L, R); 4470 // LR operator/(L, R); 4471 // LR operator+(L, R); 4472 // LR operator-(L, R); 4473 // bool operator<(L, R); 4474 // bool operator>(L, R); 4475 // bool operator<=(L, R); 4476 // bool operator>=(L, R); 4477 // bool operator==(L, R); 4478 // bool operator!=(L, R); 4479 // 4480 // where LR is the result of the usual arithmetic conversions 4481 // between types L and R. 4482 // 4483 // C++ [over.built]p24: 4484 // 4485 // For every pair of promoted arithmetic types L and R, there exist 4486 // candidate operator functions of the form 4487 // 4488 // LR operator?(bool, L, R); 4489 // 4490 // where LR is the result of the usual arithmetic conversions 4491 // between types L and R. 4492 // Our candidates ignore the first parameter. 4493 for (unsigned Left = FirstPromotedArithmeticType; 4494 Left < LastPromotedArithmeticType; ++Left) { 4495 for (unsigned Right = FirstPromotedArithmeticType; 4496 Right < LastPromotedArithmeticType; ++Right) { 4497 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 4498 QualType Result 4499 = isComparison 4500 ? Context.BoolTy 4501 : Context.UsualArithmeticConversionsType(LandR[0], LandR[1]); 4502 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 4503 } 4504 } 4505 4506 // Extension: Add the binary operators ==, !=, <, <=, >=, >, *, /, and the 4507 // conditional operator for vector types. 4508 for (BuiltinCandidateTypeSet::iterator Vec1 = CandidateTypes.vector_begin(), 4509 Vec1End = CandidateTypes.vector_end(); 4510 Vec1 != Vec1End; ++Vec1) 4511 for (BuiltinCandidateTypeSet::iterator 4512 Vec2 = CandidateTypes.vector_begin(), 4513 Vec2End = CandidateTypes.vector_end(); 4514 Vec2 != Vec2End; ++Vec2) { 4515 QualType LandR[2] = { *Vec1, *Vec2 }; 4516 QualType Result; 4517 if (isComparison) 4518 Result = Context.BoolTy; 4519 else { 4520 if ((*Vec1)->isExtVectorType() || !(*Vec2)->isExtVectorType()) 4521 Result = *Vec1; 4522 else 4523 Result = *Vec2; 4524 } 4525 4526 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 4527 } 4528 4529 break; 4530 4531 case OO_Percent: 4532 BinaryAmp: 4533 case OO_Caret: 4534 case OO_Pipe: 4535 case OO_LessLess: 4536 case OO_GreaterGreater: 4537 // C++ [over.built]p17: 4538 // 4539 // For every pair of promoted integral types L and R, there 4540 // exist candidate operator functions of the form 4541 // 4542 // LR operator%(L, R); 4543 // LR operator&(L, R); 4544 // LR operator^(L, R); 4545 // LR operator|(L, R); 4546 // L operator<<(L, R); 4547 // L operator>>(L, R); 4548 // 4549 // where LR is the result of the usual arithmetic conversions 4550 // between types L and R. 4551 for (unsigned Left = FirstPromotedIntegralType; 4552 Left < LastPromotedIntegralType; ++Left) { 4553 for (unsigned Right = FirstPromotedIntegralType; 4554 Right < LastPromotedIntegralType; ++Right) { 4555 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 4556 QualType Result = (Op == OO_LessLess || Op == OO_GreaterGreater) 4557 ? LandR[0] 4558 : Context.UsualArithmeticConversionsType(LandR[0], LandR[1]); 4559 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 4560 } 4561 } 4562 break; 4563 4564 case OO_Equal: 4565 // C++ [over.built]p20: 4566 // 4567 // For every pair (T, VQ), where T is an enumeration or 4568 // pointer to member type and VQ is either volatile or 4569 // empty, there exist candidate operator functions of the form 4570 // 4571 // VQ T& operator=(VQ T&, T); 4572 for (BuiltinCandidateTypeSet::iterator 4573 Enum = CandidateTypes.enumeration_begin(), 4574 EnumEnd = CandidateTypes.enumeration_end(); 4575 Enum != EnumEnd; ++Enum) 4576 AddBuiltinAssignmentOperatorCandidates(*this, *Enum, Args, 2, 4577 CandidateSet); 4578 for (BuiltinCandidateTypeSet::iterator 4579 MemPtr = CandidateTypes.member_pointer_begin(), 4580 MemPtrEnd = CandidateTypes.member_pointer_end(); 4581 MemPtr != MemPtrEnd; ++MemPtr) 4582 AddBuiltinAssignmentOperatorCandidates(*this, *MemPtr, Args, 2, 4583 CandidateSet); 4584 4585 // Fall through. 4586 4587 case OO_PlusEqual: 4588 case OO_MinusEqual: 4589 // C++ [over.built]p19: 4590 // 4591 // For every pair (T, VQ), where T is any type and VQ is either 4592 // volatile or empty, there exist candidate operator functions 4593 // of the form 4594 // 4595 // T*VQ& operator=(T*VQ&, T*); 4596 // 4597 // C++ [over.built]p21: 4598 // 4599 // For every pair (T, VQ), where T is a cv-qualified or 4600 // cv-unqualified object type and VQ is either volatile or 4601 // empty, there exist candidate operator functions of the form 4602 // 4603 // T*VQ& operator+=(T*VQ&, ptrdiff_t); 4604 // T*VQ& operator-=(T*VQ&, ptrdiff_t); 4605 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 4606 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4607 QualType ParamTypes[2]; 4608 ParamTypes[1] = (Op == OO_Equal)? *Ptr : Context.getPointerDiffType(); 4609 4610 // non-volatile version 4611 ParamTypes[0] = Context.getLValueReferenceType(*Ptr); 4612 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4613 /*IsAssigmentOperator=*/Op == OO_Equal); 4614 4615 if (!Context.getCanonicalType(*Ptr).isVolatileQualified() && 4616 VisibleTypeConversionsQuals.hasVolatile()) { 4617 // volatile version 4618 ParamTypes[0] 4619 = Context.getLValueReferenceType(Context.getVolatileType(*Ptr)); 4620 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4621 /*IsAssigmentOperator=*/Op == OO_Equal); 4622 } 4623 } 4624 // Fall through. 4625 4626 case OO_StarEqual: 4627 case OO_SlashEqual: 4628 // C++ [over.built]p18: 4629 // 4630 // For every triple (L, VQ, R), where L is an arithmetic type, 4631 // VQ is either volatile or empty, and R is a promoted 4632 // arithmetic type, there exist candidate operator functions of 4633 // the form 4634 // 4635 // VQ L& operator=(VQ L&, R); 4636 // VQ L& operator*=(VQ L&, R); 4637 // VQ L& operator/=(VQ L&, R); 4638 // VQ L& operator+=(VQ L&, R); 4639 // VQ L& operator-=(VQ L&, R); 4640 for (unsigned Left = 0; Left < NumArithmeticTypes; ++Left) { 4641 for (unsigned Right = FirstPromotedArithmeticType; 4642 Right < LastPromotedArithmeticType; ++Right) { 4643 QualType ParamTypes[2]; 4644 ParamTypes[1] = ArithmeticTypes[Right]; 4645 4646 // Add this built-in operator as a candidate (VQ is empty). 4647 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 4648 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4649 /*IsAssigmentOperator=*/Op == OO_Equal); 4650 4651 // Add this built-in operator as a candidate (VQ is 'volatile'). 4652 if (VisibleTypeConversionsQuals.hasVolatile()) { 4653 ParamTypes[0] = Context.getVolatileType(ArithmeticTypes[Left]); 4654 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 4655 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4656 /*IsAssigmentOperator=*/Op == OO_Equal); 4657 } 4658 } 4659 } 4660 4661 // Extension: Add the binary operators =, +=, -=, *=, /= for vector types. 4662 for (BuiltinCandidateTypeSet::iterator Vec1 = CandidateTypes.vector_begin(), 4663 Vec1End = CandidateTypes.vector_end(); 4664 Vec1 != Vec1End; ++Vec1) 4665 for (BuiltinCandidateTypeSet::iterator 4666 Vec2 = CandidateTypes.vector_begin(), 4667 Vec2End = CandidateTypes.vector_end(); 4668 Vec2 != Vec2End; ++Vec2) { 4669 QualType ParamTypes[2]; 4670 ParamTypes[1] = *Vec2; 4671 // Add this built-in operator as a candidate (VQ is empty). 4672 ParamTypes[0] = Context.getLValueReferenceType(*Vec1); 4673 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4674 /*IsAssigmentOperator=*/Op == OO_Equal); 4675 4676 // Add this built-in operator as a candidate (VQ is 'volatile'). 4677 if (VisibleTypeConversionsQuals.hasVolatile()) { 4678 ParamTypes[0] = Context.getVolatileType(*Vec1); 4679 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 4680 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4681 /*IsAssigmentOperator=*/Op == OO_Equal); 4682 } 4683 } 4684 break; 4685 4686 case OO_PercentEqual: 4687 case OO_LessLessEqual: 4688 case OO_GreaterGreaterEqual: 4689 case OO_AmpEqual: 4690 case OO_CaretEqual: 4691 case OO_PipeEqual: 4692 // C++ [over.built]p22: 4693 // 4694 // For every triple (L, VQ, R), where L is an integral type, VQ 4695 // is either volatile or empty, and R is a promoted integral 4696 // type, there exist candidate operator functions of the form 4697 // 4698 // VQ L& operator%=(VQ L&, R); 4699 // VQ L& operator<<=(VQ L&, R); 4700 // VQ L& operator>>=(VQ L&, R); 4701 // VQ L& operator&=(VQ L&, R); 4702 // VQ L& operator^=(VQ L&, R); 4703 // VQ L& operator|=(VQ L&, R); 4704 for (unsigned Left = FirstIntegralType; Left < LastIntegralType; ++Left) { 4705 for (unsigned Right = FirstPromotedIntegralType; 4706 Right < LastPromotedIntegralType; ++Right) { 4707 QualType ParamTypes[2]; 4708 ParamTypes[1] = ArithmeticTypes[Right]; 4709 4710 // Add this built-in operator as a candidate (VQ is empty). 4711 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 4712 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 4713 if (VisibleTypeConversionsQuals.hasVolatile()) { 4714 // Add this built-in operator as a candidate (VQ is 'volatile'). 4715 ParamTypes[0] = ArithmeticTypes[Left]; 4716 ParamTypes[0] = Context.getVolatileType(ParamTypes[0]); 4717 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 4718 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 4719 } 4720 } 4721 } 4722 break; 4723 4724 case OO_Exclaim: { 4725 // C++ [over.operator]p23: 4726 // 4727 // There also exist candidate operator functions of the form 4728 // 4729 // bool operator!(bool); 4730 // bool operator&&(bool, bool); [BELOW] 4731 // bool operator||(bool, bool); [BELOW] 4732 QualType ParamTy = Context.BoolTy; 4733 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet, 4734 /*IsAssignmentOperator=*/false, 4735 /*NumContextualBoolArguments=*/1); 4736 break; 4737 } 4738 4739 case OO_AmpAmp: 4740 case OO_PipePipe: { 4741 // C++ [over.operator]p23: 4742 // 4743 // There also exist candidate operator functions of the form 4744 // 4745 // bool operator!(bool); [ABOVE] 4746 // bool operator&&(bool, bool); 4747 // bool operator||(bool, bool); 4748 QualType ParamTypes[2] = { Context.BoolTy, Context.BoolTy }; 4749 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet, 4750 /*IsAssignmentOperator=*/false, 4751 /*NumContextualBoolArguments=*/2); 4752 break; 4753 } 4754 4755 case OO_Subscript: 4756 // C++ [over.built]p13: 4757 // 4758 // For every cv-qualified or cv-unqualified object type T there 4759 // exist candidate operator functions of the form 4760 // 4761 // T* operator+(T*, ptrdiff_t); [ABOVE] 4762 // T& operator[](T*, ptrdiff_t); 4763 // T* operator-(T*, ptrdiff_t); [ABOVE] 4764 // T* operator+(ptrdiff_t, T*); [ABOVE] 4765 // T& operator[](ptrdiff_t, T*); 4766 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 4767 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4768 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 4769 QualType PointeeType = (*Ptr)->getAs<PointerType>()->getPointeeType(); 4770 QualType ResultTy = Context.getLValueReferenceType(PointeeType); 4771 4772 // T& operator[](T*, ptrdiff_t) 4773 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 4774 4775 // T& operator[](ptrdiff_t, T*); 4776 ParamTypes[0] = ParamTypes[1]; 4777 ParamTypes[1] = *Ptr; 4778 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 4779 } 4780 break; 4781 4782 case OO_ArrowStar: 4783 // C++ [over.built]p11: 4784 // For every quintuple (C1, C2, T, CV1, CV2), where C2 is a class type, 4785 // C1 is the same type as C2 or is a derived class of C2, T is an object 4786 // type or a function type, and CV1 and CV2 are cv-qualifier-seqs, 4787 // there exist candidate operator functions of the form 4788 // CV12 T& operator->*(CV1 C1*, CV2 T C2::*); 4789 // where CV12 is the union of CV1 and CV2. 4790 { 4791 for (BuiltinCandidateTypeSet::iterator Ptr = 4792 CandidateTypes.pointer_begin(); 4793 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4794 QualType C1Ty = (*Ptr); 4795 QualType C1; 4796 QualifierCollector Q1; 4797 if (const PointerType *PointerTy = C1Ty->getAs<PointerType>()) { 4798 C1 = QualType(Q1.strip(PointerTy->getPointeeType()), 0); 4799 if (!isa<RecordType>(C1)) 4800 continue; 4801 // heuristic to reduce number of builtin candidates in the set. 4802 // Add volatile/restrict version only if there are conversions to a 4803 // volatile/restrict type. 4804 if (!VisibleTypeConversionsQuals.hasVolatile() && Q1.hasVolatile()) 4805 continue; 4806 if (!VisibleTypeConversionsQuals.hasRestrict() && Q1.hasRestrict()) 4807 continue; 4808 } 4809 for (BuiltinCandidateTypeSet::iterator 4810 MemPtr = CandidateTypes.member_pointer_begin(), 4811 MemPtrEnd = CandidateTypes.member_pointer_end(); 4812 MemPtr != MemPtrEnd; ++MemPtr) { 4813 const MemberPointerType *mptr = cast<MemberPointerType>(*MemPtr); 4814 QualType C2 = QualType(mptr->getClass(), 0); 4815 C2 = C2.getUnqualifiedType(); 4816 if (C1 != C2 && !IsDerivedFrom(C1, C2)) 4817 break; 4818 QualType ParamTypes[2] = { *Ptr, *MemPtr }; 4819 // build CV12 T& 4820 QualType T = mptr->getPointeeType(); 4821 if (!VisibleTypeConversionsQuals.hasVolatile() && 4822 T.isVolatileQualified()) 4823 continue; 4824 if (!VisibleTypeConversionsQuals.hasRestrict() && 4825 T.isRestrictQualified()) 4826 continue; 4827 T = Q1.apply(T); 4828 QualType ResultTy = Context.getLValueReferenceType(T); 4829 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 4830 } 4831 } 4832 } 4833 break; 4834 4835 case OO_Conditional: 4836 // Note that we don't consider the first argument, since it has been 4837 // contextually converted to bool long ago. The candidates below are 4838 // therefore added as binary. 4839 // 4840 // C++ [over.built]p24: 4841 // For every type T, where T is a pointer or pointer-to-member type, 4842 // there exist candidate operator functions of the form 4843 // 4844 // T operator?(bool, T, T); 4845 // 4846 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(), 4847 E = CandidateTypes.pointer_end(); Ptr != E; ++Ptr) { 4848 QualType ParamTypes[2] = { *Ptr, *Ptr }; 4849 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 4850 } 4851 for (BuiltinCandidateTypeSet::iterator Ptr = 4852 CandidateTypes.member_pointer_begin(), 4853 E = CandidateTypes.member_pointer_end(); Ptr != E; ++Ptr) { 4854 QualType ParamTypes[2] = { *Ptr, *Ptr }; 4855 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 4856 } 4857 goto Conditional; 4858 } 4859} 4860 4861/// \brief Add function candidates found via argument-dependent lookup 4862/// to the set of overloading candidates. 4863/// 4864/// This routine performs argument-dependent name lookup based on the 4865/// given function name (which may also be an operator name) and adds 4866/// all of the overload candidates found by ADL to the overload 4867/// candidate set (C++ [basic.lookup.argdep]). 4868void 4869Sema::AddArgumentDependentLookupCandidates(DeclarationName Name, 4870 bool Operator, 4871 Expr **Args, unsigned NumArgs, 4872 const TemplateArgumentListInfo *ExplicitTemplateArgs, 4873 OverloadCandidateSet& CandidateSet, 4874 bool PartialOverloading) { 4875 ADLResult Fns; 4876 4877 // FIXME: This approach for uniquing ADL results (and removing 4878 // redundant candidates from the set) relies on pointer-equality, 4879 // which means we need to key off the canonical decl. However, 4880 // always going back to the canonical decl might not get us the 4881 // right set of default arguments. What default arguments are 4882 // we supposed to consider on ADL candidates, anyway? 4883 4884 // FIXME: Pass in the explicit template arguments? 4885 ArgumentDependentLookup(Name, Operator, Args, NumArgs, Fns); 4886 4887 // Erase all of the candidates we already knew about. 4888 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 4889 CandEnd = CandidateSet.end(); 4890 Cand != CandEnd; ++Cand) 4891 if (Cand->Function) { 4892 Fns.erase(Cand->Function); 4893 if (FunctionTemplateDecl *FunTmpl = Cand->Function->getPrimaryTemplate()) 4894 Fns.erase(FunTmpl); 4895 } 4896 4897 // For each of the ADL candidates we found, add it to the overload 4898 // set. 4899 for (ADLResult::iterator I = Fns.begin(), E = Fns.end(); I != E; ++I) { 4900 DeclAccessPair FoundDecl = DeclAccessPair::make(*I, AS_none); 4901 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*I)) { 4902 if (ExplicitTemplateArgs) 4903 continue; 4904 4905 AddOverloadCandidate(FD, FoundDecl, Args, NumArgs, CandidateSet, 4906 false, PartialOverloading); 4907 } else 4908 AddTemplateOverloadCandidate(cast<FunctionTemplateDecl>(*I), 4909 FoundDecl, ExplicitTemplateArgs, 4910 Args, NumArgs, CandidateSet); 4911 } 4912} 4913 4914/// isBetterOverloadCandidate - Determines whether the first overload 4915/// candidate is a better candidate than the second (C++ 13.3.3p1). 4916bool 4917Sema::isBetterOverloadCandidate(const OverloadCandidate& Cand1, 4918 const OverloadCandidate& Cand2, 4919 SourceLocation Loc) { 4920 // Define viable functions to be better candidates than non-viable 4921 // functions. 4922 if (!Cand2.Viable) 4923 return Cand1.Viable; 4924 else if (!Cand1.Viable) 4925 return false; 4926 4927 // C++ [over.match.best]p1: 4928 // 4929 // -- if F is a static member function, ICS1(F) is defined such 4930 // that ICS1(F) is neither better nor worse than ICS1(G) for 4931 // any function G, and, symmetrically, ICS1(G) is neither 4932 // better nor worse than ICS1(F). 4933 unsigned StartArg = 0; 4934 if (Cand1.IgnoreObjectArgument || Cand2.IgnoreObjectArgument) 4935 StartArg = 1; 4936 4937 // C++ [over.match.best]p1: 4938 // A viable function F1 is defined to be a better function than another 4939 // viable function F2 if for all arguments i, ICSi(F1) is not a worse 4940 // conversion sequence than ICSi(F2), and then... 4941 unsigned NumArgs = Cand1.Conversions.size(); 4942 assert(Cand2.Conversions.size() == NumArgs && "Overload candidate mismatch"); 4943 bool HasBetterConversion = false; 4944 for (unsigned ArgIdx = StartArg; ArgIdx < NumArgs; ++ArgIdx) { 4945 switch (CompareImplicitConversionSequences(Cand1.Conversions[ArgIdx], 4946 Cand2.Conversions[ArgIdx])) { 4947 case ImplicitConversionSequence::Better: 4948 // Cand1 has a better conversion sequence. 4949 HasBetterConversion = true; 4950 break; 4951 4952 case ImplicitConversionSequence::Worse: 4953 // Cand1 can't be better than Cand2. 4954 return false; 4955 4956 case ImplicitConversionSequence::Indistinguishable: 4957 // Do nothing. 4958 break; 4959 } 4960 } 4961 4962 // -- for some argument j, ICSj(F1) is a better conversion sequence than 4963 // ICSj(F2), or, if not that, 4964 if (HasBetterConversion) 4965 return true; 4966 4967 // - F1 is a non-template function and F2 is a function template 4968 // specialization, or, if not that, 4969 if ((!Cand1.Function || !Cand1.Function->getPrimaryTemplate()) && 4970 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 4971 return true; 4972 4973 // -- F1 and F2 are function template specializations, and the function 4974 // template for F1 is more specialized than the template for F2 4975 // according to the partial ordering rules described in 14.5.5.2, or, 4976 // if not that, 4977 if (Cand1.Function && Cand1.Function->getPrimaryTemplate() && 4978 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 4979 if (FunctionTemplateDecl *BetterTemplate 4980 = getMoreSpecializedTemplate(Cand1.Function->getPrimaryTemplate(), 4981 Cand2.Function->getPrimaryTemplate(), 4982 Loc, 4983 isa<CXXConversionDecl>(Cand1.Function)? TPOC_Conversion 4984 : TPOC_Call)) 4985 return BetterTemplate == Cand1.Function->getPrimaryTemplate(); 4986 4987 // -- the context is an initialization by user-defined conversion 4988 // (see 8.5, 13.3.1.5) and the standard conversion sequence 4989 // from the return type of F1 to the destination type (i.e., 4990 // the type of the entity being initialized) is a better 4991 // conversion sequence than the standard conversion sequence 4992 // from the return type of F2 to the destination type. 4993 if (Cand1.Function && Cand2.Function && 4994 isa<CXXConversionDecl>(Cand1.Function) && 4995 isa<CXXConversionDecl>(Cand2.Function)) { 4996 switch (CompareStandardConversionSequences(Cand1.FinalConversion, 4997 Cand2.FinalConversion)) { 4998 case ImplicitConversionSequence::Better: 4999 // Cand1 has a better conversion sequence. 5000 return true; 5001 5002 case ImplicitConversionSequence::Worse: 5003 // Cand1 can't be better than Cand2. 5004 return false; 5005 5006 case ImplicitConversionSequence::Indistinguishable: 5007 // Do nothing 5008 break; 5009 } 5010 } 5011 5012 return false; 5013} 5014 5015/// \brief Computes the best viable function (C++ 13.3.3) 5016/// within an overload candidate set. 5017/// 5018/// \param CandidateSet the set of candidate functions. 5019/// 5020/// \param Loc the location of the function name (or operator symbol) for 5021/// which overload resolution occurs. 5022/// 5023/// \param Best f overload resolution was successful or found a deleted 5024/// function, Best points to the candidate function found. 5025/// 5026/// \returns The result of overload resolution. 5027OverloadingResult Sema::BestViableFunction(OverloadCandidateSet& CandidateSet, 5028 SourceLocation Loc, 5029 OverloadCandidateSet::iterator& Best) { 5030 // Find the best viable function. 5031 Best = CandidateSet.end(); 5032 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 5033 Cand != CandidateSet.end(); ++Cand) { 5034 if (Cand->Viable) { 5035 if (Best == CandidateSet.end() || 5036 isBetterOverloadCandidate(*Cand, *Best, Loc)) 5037 Best = Cand; 5038 } 5039 } 5040 5041 // If we didn't find any viable functions, abort. 5042 if (Best == CandidateSet.end()) 5043 return OR_No_Viable_Function; 5044 5045 // Make sure that this function is better than every other viable 5046 // function. If not, we have an ambiguity. 5047 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 5048 Cand != CandidateSet.end(); ++Cand) { 5049 if (Cand->Viable && 5050 Cand != Best && 5051 !isBetterOverloadCandidate(*Best, *Cand, Loc)) { 5052 Best = CandidateSet.end(); 5053 return OR_Ambiguous; 5054 } 5055 } 5056 5057 // Best is the best viable function. 5058 if (Best->Function && 5059 (Best->Function->isDeleted() || 5060 Best->Function->getAttr<UnavailableAttr>())) 5061 return OR_Deleted; 5062 5063 // C++ [basic.def.odr]p2: 5064 // An overloaded function is used if it is selected by overload resolution 5065 // when referred to from a potentially-evaluated expression. [Note: this 5066 // covers calls to named functions (5.2.2), operator overloading 5067 // (clause 13), user-defined conversions (12.3.2), allocation function for 5068 // placement new (5.3.4), as well as non-default initialization (8.5). 5069 if (Best->Function) 5070 MarkDeclarationReferenced(Loc, Best->Function); 5071 return OR_Success; 5072} 5073 5074namespace { 5075 5076enum OverloadCandidateKind { 5077 oc_function, 5078 oc_method, 5079 oc_constructor, 5080 oc_function_template, 5081 oc_method_template, 5082 oc_constructor_template, 5083 oc_implicit_default_constructor, 5084 oc_implicit_copy_constructor, 5085 oc_implicit_copy_assignment 5086}; 5087 5088OverloadCandidateKind ClassifyOverloadCandidate(Sema &S, 5089 FunctionDecl *Fn, 5090 std::string &Description) { 5091 bool isTemplate = false; 5092 5093 if (FunctionTemplateDecl *FunTmpl = Fn->getPrimaryTemplate()) { 5094 isTemplate = true; 5095 Description = S.getTemplateArgumentBindingsText( 5096 FunTmpl->getTemplateParameters(), *Fn->getTemplateSpecializationArgs()); 5097 } 5098 5099 if (CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(Fn)) { 5100 if (!Ctor->isImplicit()) 5101 return isTemplate ? oc_constructor_template : oc_constructor; 5102 5103 return Ctor->isCopyConstructor() ? oc_implicit_copy_constructor 5104 : oc_implicit_default_constructor; 5105 } 5106 5107 if (CXXMethodDecl *Meth = dyn_cast<CXXMethodDecl>(Fn)) { 5108 // This actually gets spelled 'candidate function' for now, but 5109 // it doesn't hurt to split it out. 5110 if (!Meth->isImplicit()) 5111 return isTemplate ? oc_method_template : oc_method; 5112 5113 assert(Meth->isCopyAssignment() 5114 && "implicit method is not copy assignment operator?"); 5115 return oc_implicit_copy_assignment; 5116 } 5117 5118 return isTemplate ? oc_function_template : oc_function; 5119} 5120 5121} // end anonymous namespace 5122 5123// Notes the location of an overload candidate. 5124void Sema::NoteOverloadCandidate(FunctionDecl *Fn) { 5125 std::string FnDesc; 5126 OverloadCandidateKind K = ClassifyOverloadCandidate(*this, Fn, FnDesc); 5127 Diag(Fn->getLocation(), diag::note_ovl_candidate) 5128 << (unsigned) K << FnDesc; 5129} 5130 5131/// Diagnoses an ambiguous conversion. The partial diagnostic is the 5132/// "lead" diagnostic; it will be given two arguments, the source and 5133/// target types of the conversion. 5134void Sema::DiagnoseAmbiguousConversion(const ImplicitConversionSequence &ICS, 5135 SourceLocation CaretLoc, 5136 const PartialDiagnostic &PDiag) { 5137 Diag(CaretLoc, PDiag) 5138 << ICS.Ambiguous.getFromType() << ICS.Ambiguous.getToType(); 5139 for (AmbiguousConversionSequence::const_iterator 5140 I = ICS.Ambiguous.begin(), E = ICS.Ambiguous.end(); I != E; ++I) { 5141 NoteOverloadCandidate(*I); 5142 } 5143} 5144 5145namespace { 5146 5147void DiagnoseBadConversion(Sema &S, OverloadCandidate *Cand, unsigned I) { 5148 const ImplicitConversionSequence &Conv = Cand->Conversions[I]; 5149 assert(Conv.isBad()); 5150 assert(Cand->Function && "for now, candidate must be a function"); 5151 FunctionDecl *Fn = Cand->Function; 5152 5153 // There's a conversion slot for the object argument if this is a 5154 // non-constructor method. Note that 'I' corresponds the 5155 // conversion-slot index. 5156 bool isObjectArgument = false; 5157 if (isa<CXXMethodDecl>(Fn) && !isa<CXXConstructorDecl>(Fn)) { 5158 if (I == 0) 5159 isObjectArgument = true; 5160 else 5161 I--; 5162 } 5163 5164 std::string FnDesc; 5165 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, FnDesc); 5166 5167 Expr *FromExpr = Conv.Bad.FromExpr; 5168 QualType FromTy = Conv.Bad.getFromType(); 5169 QualType ToTy = Conv.Bad.getToType(); 5170 5171 if (FromTy == S.Context.OverloadTy) { 5172 assert(FromExpr && "overload set argument came from implicit argument?"); 5173 Expr *E = FromExpr->IgnoreParens(); 5174 if (isa<UnaryOperator>(E)) 5175 E = cast<UnaryOperator>(E)->getSubExpr()->IgnoreParens(); 5176 DeclarationName Name = cast<OverloadExpr>(E)->getName(); 5177 5178 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_overload) 5179 << (unsigned) FnKind << FnDesc 5180 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 5181 << ToTy << Name << I+1; 5182 return; 5183 } 5184 5185 // Do some hand-waving analysis to see if the non-viability is due 5186 // to a qualifier mismatch. 5187 CanQualType CFromTy = S.Context.getCanonicalType(FromTy); 5188 CanQualType CToTy = S.Context.getCanonicalType(ToTy); 5189 if (CanQual<ReferenceType> RT = CToTy->getAs<ReferenceType>()) 5190 CToTy = RT->getPointeeType(); 5191 else { 5192 // TODO: detect and diagnose the full richness of const mismatches. 5193 if (CanQual<PointerType> FromPT = CFromTy->getAs<PointerType>()) 5194 if (CanQual<PointerType> ToPT = CToTy->getAs<PointerType>()) 5195 CFromTy = FromPT->getPointeeType(), CToTy = ToPT->getPointeeType(); 5196 } 5197 5198 if (CToTy.getUnqualifiedType() == CFromTy.getUnqualifiedType() && 5199 !CToTy.isAtLeastAsQualifiedAs(CFromTy)) { 5200 // It is dumb that we have to do this here. 5201 while (isa<ArrayType>(CFromTy)) 5202 CFromTy = CFromTy->getAs<ArrayType>()->getElementType(); 5203 while (isa<ArrayType>(CToTy)) 5204 CToTy = CFromTy->getAs<ArrayType>()->getElementType(); 5205 5206 Qualifiers FromQs = CFromTy.getQualifiers(); 5207 Qualifiers ToQs = CToTy.getQualifiers(); 5208 5209 if (FromQs.getAddressSpace() != ToQs.getAddressSpace()) { 5210 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_addrspace) 5211 << (unsigned) FnKind << FnDesc 5212 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 5213 << FromTy 5214 << FromQs.getAddressSpace() << ToQs.getAddressSpace() 5215 << (unsigned) isObjectArgument << I+1; 5216 return; 5217 } 5218 5219 unsigned CVR = FromQs.getCVRQualifiers() & ~ToQs.getCVRQualifiers(); 5220 assert(CVR && "unexpected qualifiers mismatch"); 5221 5222 if (isObjectArgument) { 5223 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr_this) 5224 << (unsigned) FnKind << FnDesc 5225 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 5226 << FromTy << (CVR - 1); 5227 } else { 5228 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr) 5229 << (unsigned) FnKind << FnDesc 5230 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 5231 << FromTy << (CVR - 1) << I+1; 5232 } 5233 return; 5234 } 5235 5236 // Diagnose references or pointers to incomplete types differently, 5237 // since it's far from impossible that the incompleteness triggered 5238 // the failure. 5239 QualType TempFromTy = FromTy.getNonReferenceType(); 5240 if (const PointerType *PTy = TempFromTy->getAs<PointerType>()) 5241 TempFromTy = PTy->getPointeeType(); 5242 if (TempFromTy->isIncompleteType()) { 5243 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_conv_incomplete) 5244 << (unsigned) FnKind << FnDesc 5245 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 5246 << FromTy << ToTy << (unsigned) isObjectArgument << I+1; 5247 return; 5248 } 5249 5250 // TODO: specialize more based on the kind of mismatch 5251 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_conv) 5252 << (unsigned) FnKind << FnDesc 5253 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 5254 << FromTy << ToTy << (unsigned) isObjectArgument << I+1; 5255} 5256 5257void DiagnoseArityMismatch(Sema &S, OverloadCandidate *Cand, 5258 unsigned NumFormalArgs) { 5259 // TODO: treat calls to a missing default constructor as a special case 5260 5261 FunctionDecl *Fn = Cand->Function; 5262 const FunctionProtoType *FnTy = Fn->getType()->getAs<FunctionProtoType>(); 5263 5264 unsigned MinParams = Fn->getMinRequiredArguments(); 5265 5266 // at least / at most / exactly 5267 // FIXME: variadic templates "at most" should account for parameter packs 5268 unsigned mode, modeCount; 5269 if (NumFormalArgs < MinParams) { 5270 assert((Cand->FailureKind == ovl_fail_too_few_arguments) || 5271 (Cand->FailureKind == ovl_fail_bad_deduction && 5272 Cand->DeductionFailure.Result == Sema::TDK_TooFewArguments)); 5273 if (MinParams != FnTy->getNumArgs() || FnTy->isVariadic()) 5274 mode = 0; // "at least" 5275 else 5276 mode = 2; // "exactly" 5277 modeCount = MinParams; 5278 } else { 5279 assert((Cand->FailureKind == ovl_fail_too_many_arguments) || 5280 (Cand->FailureKind == ovl_fail_bad_deduction && 5281 Cand->DeductionFailure.Result == Sema::TDK_TooManyArguments)); 5282 if (MinParams != FnTy->getNumArgs()) 5283 mode = 1; // "at most" 5284 else 5285 mode = 2; // "exactly" 5286 modeCount = FnTy->getNumArgs(); 5287 } 5288 5289 std::string Description; 5290 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, Description); 5291 5292 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_arity) 5293 << (unsigned) FnKind << (Fn->getDescribedFunctionTemplate() != 0) << mode 5294 << modeCount << NumFormalArgs; 5295} 5296 5297/// Diagnose a failed template-argument deduction. 5298void DiagnoseBadDeduction(Sema &S, OverloadCandidate *Cand, 5299 Expr **Args, unsigned NumArgs) { 5300 FunctionDecl *Fn = Cand->Function; // pattern 5301 5302 TemplateParameter Param = Cand->DeductionFailure.getTemplateParameter(); 5303 NamedDecl *ParamD; 5304 (ParamD = Param.dyn_cast<TemplateTypeParmDecl*>()) || 5305 (ParamD = Param.dyn_cast<NonTypeTemplateParmDecl*>()) || 5306 (ParamD = Param.dyn_cast<TemplateTemplateParmDecl*>()); 5307 switch (Cand->DeductionFailure.Result) { 5308 case Sema::TDK_Success: 5309 llvm_unreachable("TDK_success while diagnosing bad deduction"); 5310 5311 case Sema::TDK_Incomplete: { 5312 assert(ParamD && "no parameter found for incomplete deduction result"); 5313 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_incomplete_deduction) 5314 << ParamD->getDeclName(); 5315 return; 5316 } 5317 5318 case Sema::TDK_Inconsistent: 5319 case Sema::TDK_InconsistentQuals: { 5320 assert(ParamD && "no parameter found for inconsistent deduction result"); 5321 int which = 0; 5322 if (isa<TemplateTypeParmDecl>(ParamD)) 5323 which = 0; 5324 else if (isa<NonTypeTemplateParmDecl>(ParamD)) 5325 which = 1; 5326 else { 5327 which = 2; 5328 } 5329 5330 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_inconsistent_deduction) 5331 << which << ParamD->getDeclName() 5332 << *Cand->DeductionFailure.getFirstArg() 5333 << *Cand->DeductionFailure.getSecondArg(); 5334 return; 5335 } 5336 5337 case Sema::TDK_InvalidExplicitArguments: 5338 assert(ParamD && "no parameter found for invalid explicit arguments"); 5339 if (ParamD->getDeclName()) 5340 S.Diag(Fn->getLocation(), 5341 diag::note_ovl_candidate_explicit_arg_mismatch_named) 5342 << ParamD->getDeclName(); 5343 else { 5344 int index = 0; 5345 if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(ParamD)) 5346 index = TTP->getIndex(); 5347 else if (NonTypeTemplateParmDecl *NTTP 5348 = dyn_cast<NonTypeTemplateParmDecl>(ParamD)) 5349 index = NTTP->getIndex(); 5350 else 5351 index = cast<TemplateTemplateParmDecl>(ParamD)->getIndex(); 5352 S.Diag(Fn->getLocation(), 5353 diag::note_ovl_candidate_explicit_arg_mismatch_unnamed) 5354 << (index + 1); 5355 } 5356 return; 5357 5358 case Sema::TDK_TooManyArguments: 5359 case Sema::TDK_TooFewArguments: 5360 DiagnoseArityMismatch(S, Cand, NumArgs); 5361 return; 5362 5363 case Sema::TDK_InstantiationDepth: 5364 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_instantiation_depth); 5365 return; 5366 5367 case Sema::TDK_SubstitutionFailure: { 5368 std::string ArgString; 5369 if (TemplateArgumentList *Args 5370 = Cand->DeductionFailure.getTemplateArgumentList()) 5371 ArgString = S.getTemplateArgumentBindingsText( 5372 Fn->getDescribedFunctionTemplate()->getTemplateParameters(), 5373 *Args); 5374 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_substitution_failure) 5375 << ArgString; 5376 return; 5377 } 5378 5379 // TODO: diagnose these individually, then kill off 5380 // note_ovl_candidate_bad_deduction, which is uselessly vague. 5381 case Sema::TDK_NonDeducedMismatch: 5382 case Sema::TDK_FailedOverloadResolution: 5383 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_deduction); 5384 return; 5385 } 5386} 5387 5388/// Generates a 'note' diagnostic for an overload candidate. We've 5389/// already generated a primary error at the call site. 5390/// 5391/// It really does need to be a single diagnostic with its caret 5392/// pointed at the candidate declaration. Yes, this creates some 5393/// major challenges of technical writing. Yes, this makes pointing 5394/// out problems with specific arguments quite awkward. It's still 5395/// better than generating twenty screens of text for every failed 5396/// overload. 5397/// 5398/// It would be great to be able to express per-candidate problems 5399/// more richly for those diagnostic clients that cared, but we'd 5400/// still have to be just as careful with the default diagnostics. 5401void NoteFunctionCandidate(Sema &S, OverloadCandidate *Cand, 5402 Expr **Args, unsigned NumArgs) { 5403 FunctionDecl *Fn = Cand->Function; 5404 5405 // Note deleted candidates, but only if they're viable. 5406 if (Cand->Viable && (Fn->isDeleted() || Fn->hasAttr<UnavailableAttr>())) { 5407 std::string FnDesc; 5408 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, FnDesc); 5409 5410 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_deleted) 5411 << FnKind << FnDesc << Fn->isDeleted(); 5412 return; 5413 } 5414 5415 // We don't really have anything else to say about viable candidates. 5416 if (Cand->Viable) { 5417 S.NoteOverloadCandidate(Fn); 5418 return; 5419 } 5420 5421 switch (Cand->FailureKind) { 5422 case ovl_fail_too_many_arguments: 5423 case ovl_fail_too_few_arguments: 5424 return DiagnoseArityMismatch(S, Cand, NumArgs); 5425 5426 case ovl_fail_bad_deduction: 5427 return DiagnoseBadDeduction(S, Cand, Args, NumArgs); 5428 5429 case ovl_fail_trivial_conversion: 5430 case ovl_fail_bad_final_conversion: 5431 case ovl_fail_final_conversion_not_exact: 5432 return S.NoteOverloadCandidate(Fn); 5433 5434 case ovl_fail_bad_conversion: { 5435 unsigned I = (Cand->IgnoreObjectArgument ? 1 : 0); 5436 for (unsigned N = Cand->Conversions.size(); I != N; ++I) 5437 if (Cand->Conversions[I].isBad()) 5438 return DiagnoseBadConversion(S, Cand, I); 5439 5440 // FIXME: this currently happens when we're called from SemaInit 5441 // when user-conversion overload fails. Figure out how to handle 5442 // those conditions and diagnose them well. 5443 return S.NoteOverloadCandidate(Fn); 5444 } 5445 } 5446} 5447 5448void NoteSurrogateCandidate(Sema &S, OverloadCandidate *Cand) { 5449 // Desugar the type of the surrogate down to a function type, 5450 // retaining as many typedefs as possible while still showing 5451 // the function type (and, therefore, its parameter types). 5452 QualType FnType = Cand->Surrogate->getConversionType(); 5453 bool isLValueReference = false; 5454 bool isRValueReference = false; 5455 bool isPointer = false; 5456 if (const LValueReferenceType *FnTypeRef = 5457 FnType->getAs<LValueReferenceType>()) { 5458 FnType = FnTypeRef->getPointeeType(); 5459 isLValueReference = true; 5460 } else if (const RValueReferenceType *FnTypeRef = 5461 FnType->getAs<RValueReferenceType>()) { 5462 FnType = FnTypeRef->getPointeeType(); 5463 isRValueReference = true; 5464 } 5465 if (const PointerType *FnTypePtr = FnType->getAs<PointerType>()) { 5466 FnType = FnTypePtr->getPointeeType(); 5467 isPointer = true; 5468 } 5469 // Desugar down to a function type. 5470 FnType = QualType(FnType->getAs<FunctionType>(), 0); 5471 // Reconstruct the pointer/reference as appropriate. 5472 if (isPointer) FnType = S.Context.getPointerType(FnType); 5473 if (isRValueReference) FnType = S.Context.getRValueReferenceType(FnType); 5474 if (isLValueReference) FnType = S.Context.getLValueReferenceType(FnType); 5475 5476 S.Diag(Cand->Surrogate->getLocation(), diag::note_ovl_surrogate_cand) 5477 << FnType; 5478} 5479 5480void NoteBuiltinOperatorCandidate(Sema &S, 5481 const char *Opc, 5482 SourceLocation OpLoc, 5483 OverloadCandidate *Cand) { 5484 assert(Cand->Conversions.size() <= 2 && "builtin operator is not binary"); 5485 std::string TypeStr("operator"); 5486 TypeStr += Opc; 5487 TypeStr += "("; 5488 TypeStr += Cand->BuiltinTypes.ParamTypes[0].getAsString(); 5489 if (Cand->Conversions.size() == 1) { 5490 TypeStr += ")"; 5491 S.Diag(OpLoc, diag::note_ovl_builtin_unary_candidate) << TypeStr; 5492 } else { 5493 TypeStr += ", "; 5494 TypeStr += Cand->BuiltinTypes.ParamTypes[1].getAsString(); 5495 TypeStr += ")"; 5496 S.Diag(OpLoc, diag::note_ovl_builtin_binary_candidate) << TypeStr; 5497 } 5498} 5499 5500void NoteAmbiguousUserConversions(Sema &S, SourceLocation OpLoc, 5501 OverloadCandidate *Cand) { 5502 unsigned NoOperands = Cand->Conversions.size(); 5503 for (unsigned ArgIdx = 0; ArgIdx < NoOperands; ++ArgIdx) { 5504 const ImplicitConversionSequence &ICS = Cand->Conversions[ArgIdx]; 5505 if (ICS.isBad()) break; // all meaningless after first invalid 5506 if (!ICS.isAmbiguous()) continue; 5507 5508 S.DiagnoseAmbiguousConversion(ICS, OpLoc, 5509 S.PDiag(diag::note_ambiguous_type_conversion)); 5510 } 5511} 5512 5513SourceLocation GetLocationForCandidate(const OverloadCandidate *Cand) { 5514 if (Cand->Function) 5515 return Cand->Function->getLocation(); 5516 if (Cand->IsSurrogate) 5517 return Cand->Surrogate->getLocation(); 5518 return SourceLocation(); 5519} 5520 5521struct CompareOverloadCandidatesForDisplay { 5522 Sema &S; 5523 CompareOverloadCandidatesForDisplay(Sema &S) : S(S) {} 5524 5525 bool operator()(const OverloadCandidate *L, 5526 const OverloadCandidate *R) { 5527 // Fast-path this check. 5528 if (L == R) return false; 5529 5530 // Order first by viability. 5531 if (L->Viable) { 5532 if (!R->Viable) return true; 5533 5534 // TODO: introduce a tri-valued comparison for overload 5535 // candidates. Would be more worthwhile if we had a sort 5536 // that could exploit it. 5537 if (S.isBetterOverloadCandidate(*L, *R, SourceLocation())) return true; 5538 if (S.isBetterOverloadCandidate(*R, *L, SourceLocation())) return false; 5539 } else if (R->Viable) 5540 return false; 5541 5542 assert(L->Viable == R->Viable); 5543 5544 // Criteria by which we can sort non-viable candidates: 5545 if (!L->Viable) { 5546 // 1. Arity mismatches come after other candidates. 5547 if (L->FailureKind == ovl_fail_too_many_arguments || 5548 L->FailureKind == ovl_fail_too_few_arguments) 5549 return false; 5550 if (R->FailureKind == ovl_fail_too_many_arguments || 5551 R->FailureKind == ovl_fail_too_few_arguments) 5552 return true; 5553 5554 // 2. Bad conversions come first and are ordered by the number 5555 // of bad conversions and quality of good conversions. 5556 if (L->FailureKind == ovl_fail_bad_conversion) { 5557 if (R->FailureKind != ovl_fail_bad_conversion) 5558 return true; 5559 5560 // If there's any ordering between the defined conversions... 5561 // FIXME: this might not be transitive. 5562 assert(L->Conversions.size() == R->Conversions.size()); 5563 5564 int leftBetter = 0; 5565 unsigned I = (L->IgnoreObjectArgument || R->IgnoreObjectArgument); 5566 for (unsigned E = L->Conversions.size(); I != E; ++I) { 5567 switch (S.CompareImplicitConversionSequences(L->Conversions[I], 5568 R->Conversions[I])) { 5569 case ImplicitConversionSequence::Better: 5570 leftBetter++; 5571 break; 5572 5573 case ImplicitConversionSequence::Worse: 5574 leftBetter--; 5575 break; 5576 5577 case ImplicitConversionSequence::Indistinguishable: 5578 break; 5579 } 5580 } 5581 if (leftBetter > 0) return true; 5582 if (leftBetter < 0) return false; 5583 5584 } else if (R->FailureKind == ovl_fail_bad_conversion) 5585 return false; 5586 5587 // TODO: others? 5588 } 5589 5590 // Sort everything else by location. 5591 SourceLocation LLoc = GetLocationForCandidate(L); 5592 SourceLocation RLoc = GetLocationForCandidate(R); 5593 5594 // Put candidates without locations (e.g. builtins) at the end. 5595 if (LLoc.isInvalid()) return false; 5596 if (RLoc.isInvalid()) return true; 5597 5598 return S.SourceMgr.isBeforeInTranslationUnit(LLoc, RLoc); 5599 } 5600}; 5601 5602/// CompleteNonViableCandidate - Normally, overload resolution only 5603/// computes up to the first 5604void CompleteNonViableCandidate(Sema &S, OverloadCandidate *Cand, 5605 Expr **Args, unsigned NumArgs) { 5606 assert(!Cand->Viable); 5607 5608 // Don't do anything on failures other than bad conversion. 5609 if (Cand->FailureKind != ovl_fail_bad_conversion) return; 5610 5611 // Skip forward to the first bad conversion. 5612 unsigned ConvIdx = (Cand->IgnoreObjectArgument ? 1 : 0); 5613 unsigned ConvCount = Cand->Conversions.size(); 5614 while (true) { 5615 assert(ConvIdx != ConvCount && "no bad conversion in candidate"); 5616 ConvIdx++; 5617 if (Cand->Conversions[ConvIdx - 1].isBad()) 5618 break; 5619 } 5620 5621 if (ConvIdx == ConvCount) 5622 return; 5623 5624 assert(!Cand->Conversions[ConvIdx].isInitialized() && 5625 "remaining conversion is initialized?"); 5626 5627 // FIXME: this should probably be preserved from the overload 5628 // operation somehow. 5629 bool SuppressUserConversions = false; 5630 5631 const FunctionProtoType* Proto; 5632 unsigned ArgIdx = ConvIdx; 5633 5634 if (Cand->IsSurrogate) { 5635 QualType ConvType 5636 = Cand->Surrogate->getConversionType().getNonReferenceType(); 5637 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 5638 ConvType = ConvPtrType->getPointeeType(); 5639 Proto = ConvType->getAs<FunctionProtoType>(); 5640 ArgIdx--; 5641 } else if (Cand->Function) { 5642 Proto = Cand->Function->getType()->getAs<FunctionProtoType>(); 5643 if (isa<CXXMethodDecl>(Cand->Function) && 5644 !isa<CXXConstructorDecl>(Cand->Function)) 5645 ArgIdx--; 5646 } else { 5647 // Builtin binary operator with a bad first conversion. 5648 assert(ConvCount <= 3); 5649 for (; ConvIdx != ConvCount; ++ConvIdx) 5650 Cand->Conversions[ConvIdx] 5651 = TryCopyInitialization(S, Args[ConvIdx], 5652 Cand->BuiltinTypes.ParamTypes[ConvIdx], 5653 SuppressUserConversions, 5654 /*InOverloadResolution*/ true); 5655 return; 5656 } 5657 5658 // Fill in the rest of the conversions. 5659 unsigned NumArgsInProto = Proto->getNumArgs(); 5660 for (; ConvIdx != ConvCount; ++ConvIdx, ++ArgIdx) { 5661 if (ArgIdx < NumArgsInProto) 5662 Cand->Conversions[ConvIdx] 5663 = TryCopyInitialization(S, Args[ArgIdx], Proto->getArgType(ArgIdx), 5664 SuppressUserConversions, 5665 /*InOverloadResolution=*/true); 5666 else 5667 Cand->Conversions[ConvIdx].setEllipsis(); 5668 } 5669} 5670 5671} // end anonymous namespace 5672 5673/// PrintOverloadCandidates - When overload resolution fails, prints 5674/// diagnostic messages containing the candidates in the candidate 5675/// set. 5676void 5677Sema::PrintOverloadCandidates(OverloadCandidateSet& CandidateSet, 5678 OverloadCandidateDisplayKind OCD, 5679 Expr **Args, unsigned NumArgs, 5680 const char *Opc, 5681 SourceLocation OpLoc) { 5682 // Sort the candidates by viability and position. Sorting directly would 5683 // be prohibitive, so we make a set of pointers and sort those. 5684 llvm::SmallVector<OverloadCandidate*, 32> Cands; 5685 if (OCD == OCD_AllCandidates) Cands.reserve(CandidateSet.size()); 5686 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 5687 LastCand = CandidateSet.end(); 5688 Cand != LastCand; ++Cand) { 5689 if (Cand->Viable) 5690 Cands.push_back(Cand); 5691 else if (OCD == OCD_AllCandidates) { 5692 CompleteNonViableCandidate(*this, Cand, Args, NumArgs); 5693 if (Cand->Function || Cand->IsSurrogate) 5694 Cands.push_back(Cand); 5695 // Otherwise, this a non-viable builtin candidate. We do not, in general, 5696 // want to list every possible builtin candidate. 5697 } 5698 } 5699 5700 std::sort(Cands.begin(), Cands.end(), 5701 CompareOverloadCandidatesForDisplay(*this)); 5702 5703 bool ReportedAmbiguousConversions = false; 5704 5705 llvm::SmallVectorImpl<OverloadCandidate*>::iterator I, E; 5706 const Diagnostic::OverloadsShown ShowOverloads = Diags.getShowOverloads(); 5707 unsigned CandsShown = 0; 5708 for (I = Cands.begin(), E = Cands.end(); I != E; ++I) { 5709 OverloadCandidate *Cand = *I; 5710 5711 // Set an arbitrary limit on the number of candidate functions we'll spam 5712 // the user with. FIXME: This limit should depend on details of the 5713 // candidate list. 5714 if (CandsShown >= 4 && ShowOverloads == Diagnostic::Ovl_Best) { 5715 break; 5716 } 5717 ++CandsShown; 5718 5719 if (Cand->Function) 5720 NoteFunctionCandidate(*this, Cand, Args, NumArgs); 5721 else if (Cand->IsSurrogate) 5722 NoteSurrogateCandidate(*this, Cand); 5723 else { 5724 assert(Cand->Viable && 5725 "Non-viable built-in candidates are not added to Cands."); 5726 // Generally we only see ambiguities including viable builtin 5727 // operators if overload resolution got screwed up by an 5728 // ambiguous user-defined conversion. 5729 // 5730 // FIXME: It's quite possible for different conversions to see 5731 // different ambiguities, though. 5732 if (!ReportedAmbiguousConversions) { 5733 NoteAmbiguousUserConversions(*this, OpLoc, Cand); 5734 ReportedAmbiguousConversions = true; 5735 } 5736 5737 // If this is a viable builtin, print it. 5738 NoteBuiltinOperatorCandidate(*this, Opc, OpLoc, Cand); 5739 } 5740 } 5741 5742 if (I != E) 5743 Diag(OpLoc, diag::note_ovl_too_many_candidates) << int(E - I); 5744} 5745 5746static bool CheckUnresolvedAccess(Sema &S, OverloadExpr *E, DeclAccessPair D) { 5747 if (isa<UnresolvedLookupExpr>(E)) 5748 return S.CheckUnresolvedLookupAccess(cast<UnresolvedLookupExpr>(E), D); 5749 5750 return S.CheckUnresolvedMemberAccess(cast<UnresolvedMemberExpr>(E), D); 5751} 5752 5753/// ResolveAddressOfOverloadedFunction - Try to resolve the address of 5754/// an overloaded function (C++ [over.over]), where @p From is an 5755/// expression with overloaded function type and @p ToType is the type 5756/// we're trying to resolve to. For example: 5757/// 5758/// @code 5759/// int f(double); 5760/// int f(int); 5761/// 5762/// int (*pfd)(double) = f; // selects f(double) 5763/// @endcode 5764/// 5765/// This routine returns the resulting FunctionDecl if it could be 5766/// resolved, and NULL otherwise. When @p Complain is true, this 5767/// routine will emit diagnostics if there is an error. 5768FunctionDecl * 5769Sema::ResolveAddressOfOverloadedFunction(Expr *From, QualType ToType, 5770 bool Complain, 5771 DeclAccessPair &FoundResult) { 5772 QualType FunctionType = ToType; 5773 bool IsMember = false; 5774 if (const PointerType *ToTypePtr = ToType->getAs<PointerType>()) 5775 FunctionType = ToTypePtr->getPointeeType(); 5776 else if (const ReferenceType *ToTypeRef = ToType->getAs<ReferenceType>()) 5777 FunctionType = ToTypeRef->getPointeeType(); 5778 else if (const MemberPointerType *MemTypePtr = 5779 ToType->getAs<MemberPointerType>()) { 5780 FunctionType = MemTypePtr->getPointeeType(); 5781 IsMember = true; 5782 } 5783 5784 // C++ [over.over]p1: 5785 // [...] [Note: any redundant set of parentheses surrounding the 5786 // overloaded function name is ignored (5.1). ] 5787 // C++ [over.over]p1: 5788 // [...] The overloaded function name can be preceded by the & 5789 // operator. 5790 OverloadExpr *OvlExpr = OverloadExpr::find(From).getPointer(); 5791 TemplateArgumentListInfo ETABuffer, *ExplicitTemplateArgs = 0; 5792 if (OvlExpr->hasExplicitTemplateArgs()) { 5793 OvlExpr->getExplicitTemplateArgs().copyInto(ETABuffer); 5794 ExplicitTemplateArgs = &ETABuffer; 5795 } 5796 5797 // We expect a pointer or reference to function, or a function pointer. 5798 FunctionType = Context.getCanonicalType(FunctionType).getUnqualifiedType(); 5799 if (!FunctionType->isFunctionType()) { 5800 if (Complain) 5801 Diag(From->getLocStart(), diag::err_addr_ovl_not_func_ptrref) 5802 << OvlExpr->getName() << ToType; 5803 5804 return 0; 5805 } 5806 5807 assert(From->getType() == Context.OverloadTy); 5808 5809 // Look through all of the overloaded functions, searching for one 5810 // whose type matches exactly. 5811 llvm::SmallVector<std::pair<DeclAccessPair, FunctionDecl*>, 4> Matches; 5812 llvm::SmallVector<FunctionDecl *, 4> NonMatches; 5813 5814 bool FoundNonTemplateFunction = false; 5815 for (UnresolvedSetIterator I = OvlExpr->decls_begin(), 5816 E = OvlExpr->decls_end(); I != E; ++I) { 5817 // Look through any using declarations to find the underlying function. 5818 NamedDecl *Fn = (*I)->getUnderlyingDecl(); 5819 5820 // C++ [over.over]p3: 5821 // Non-member functions and static member functions match 5822 // targets of type "pointer-to-function" or "reference-to-function." 5823 // Nonstatic member functions match targets of 5824 // type "pointer-to-member-function." 5825 // Note that according to DR 247, the containing class does not matter. 5826 5827 if (FunctionTemplateDecl *FunctionTemplate 5828 = dyn_cast<FunctionTemplateDecl>(Fn)) { 5829 if (CXXMethodDecl *Method 5830 = dyn_cast<CXXMethodDecl>(FunctionTemplate->getTemplatedDecl())) { 5831 // Skip non-static function templates when converting to pointer, and 5832 // static when converting to member pointer. 5833 if (Method->isStatic() == IsMember) 5834 continue; 5835 } else if (IsMember) 5836 continue; 5837 5838 // C++ [over.over]p2: 5839 // If the name is a function template, template argument deduction is 5840 // done (14.8.2.2), and if the argument deduction succeeds, the 5841 // resulting template argument list is used to generate a single 5842 // function template specialization, which is added to the set of 5843 // overloaded functions considered. 5844 // FIXME: We don't really want to build the specialization here, do we? 5845 FunctionDecl *Specialization = 0; 5846 TemplateDeductionInfo Info(Context, OvlExpr->getNameLoc()); 5847 if (TemplateDeductionResult Result 5848 = DeduceTemplateArguments(FunctionTemplate, ExplicitTemplateArgs, 5849 FunctionType, Specialization, Info)) { 5850 // FIXME: make a note of the failed deduction for diagnostics. 5851 (void)Result; 5852 } else { 5853 // FIXME: If the match isn't exact, shouldn't we just drop this as 5854 // a candidate? Find a testcase before changing the code. 5855 assert(FunctionType 5856 == Context.getCanonicalType(Specialization->getType())); 5857 Matches.push_back(std::make_pair(I.getPair(), 5858 cast<FunctionDecl>(Specialization->getCanonicalDecl()))); 5859 } 5860 5861 continue; 5862 } 5863 5864 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 5865 // Skip non-static functions when converting to pointer, and static 5866 // when converting to member pointer. 5867 if (Method->isStatic() == IsMember) 5868 continue; 5869 5870 // If we have explicit template arguments, skip non-templates. 5871 if (OvlExpr->hasExplicitTemplateArgs()) 5872 continue; 5873 } else if (IsMember) 5874 continue; 5875 5876 if (FunctionDecl *FunDecl = dyn_cast<FunctionDecl>(Fn)) { 5877 QualType ResultTy; 5878 if (Context.hasSameUnqualifiedType(FunctionType, FunDecl->getType()) || 5879 IsNoReturnConversion(Context, FunDecl->getType(), FunctionType, 5880 ResultTy)) { 5881 Matches.push_back(std::make_pair(I.getPair(), 5882 cast<FunctionDecl>(FunDecl->getCanonicalDecl()))); 5883 FoundNonTemplateFunction = true; 5884 } 5885 } 5886 } 5887 5888 // If there were 0 or 1 matches, we're done. 5889 if (Matches.empty()) { 5890 if (Complain) { 5891 Diag(From->getLocStart(), diag::err_addr_ovl_no_viable) 5892 << OvlExpr->getName() << FunctionType; 5893 for (UnresolvedSetIterator I = OvlExpr->decls_begin(), 5894 E = OvlExpr->decls_end(); 5895 I != E; ++I) 5896 if (FunctionDecl *F = dyn_cast<FunctionDecl>((*I)->getUnderlyingDecl())) 5897 NoteOverloadCandidate(F); 5898 } 5899 5900 return 0; 5901 } else if (Matches.size() == 1) { 5902 FunctionDecl *Result = Matches[0].second; 5903 FoundResult = Matches[0].first; 5904 MarkDeclarationReferenced(From->getLocStart(), Result); 5905 if (Complain) 5906 CheckAddressOfMemberAccess(OvlExpr, Matches[0].first); 5907 return Result; 5908 } 5909 5910 // C++ [over.over]p4: 5911 // If more than one function is selected, [...] 5912 if (!FoundNonTemplateFunction) { 5913 // [...] and any given function template specialization F1 is 5914 // eliminated if the set contains a second function template 5915 // specialization whose function template is more specialized 5916 // than the function template of F1 according to the partial 5917 // ordering rules of 14.5.5.2. 5918 5919 // The algorithm specified above is quadratic. We instead use a 5920 // two-pass algorithm (similar to the one used to identify the 5921 // best viable function in an overload set) that identifies the 5922 // best function template (if it exists). 5923 5924 UnresolvedSet<4> MatchesCopy; // TODO: avoid! 5925 for (unsigned I = 0, E = Matches.size(); I != E; ++I) 5926 MatchesCopy.addDecl(Matches[I].second, Matches[I].first.getAccess()); 5927 5928 UnresolvedSetIterator Result = 5929 getMostSpecialized(MatchesCopy.begin(), MatchesCopy.end(), 5930 TPOC_Other, From->getLocStart(), 5931 PDiag(), 5932 PDiag(diag::err_addr_ovl_ambiguous) 5933 << Matches[0].second->getDeclName(), 5934 PDiag(diag::note_ovl_candidate) 5935 << (unsigned) oc_function_template); 5936 assert(Result != MatchesCopy.end() && "no most-specialized template"); 5937 MarkDeclarationReferenced(From->getLocStart(), *Result); 5938 FoundResult = Matches[Result - MatchesCopy.begin()].first; 5939 if (Complain) { 5940 CheckUnresolvedAccess(*this, OvlExpr, FoundResult); 5941 DiagnoseUseOfDecl(FoundResult, OvlExpr->getNameLoc()); 5942 } 5943 return cast<FunctionDecl>(*Result); 5944 } 5945 5946 // [...] any function template specializations in the set are 5947 // eliminated if the set also contains a non-template function, [...] 5948 for (unsigned I = 0, N = Matches.size(); I != N; ) { 5949 if (Matches[I].second->getPrimaryTemplate() == 0) 5950 ++I; 5951 else { 5952 Matches[I] = Matches[--N]; 5953 Matches.set_size(N); 5954 } 5955 } 5956 5957 // [...] After such eliminations, if any, there shall remain exactly one 5958 // selected function. 5959 if (Matches.size() == 1) { 5960 MarkDeclarationReferenced(From->getLocStart(), Matches[0].second); 5961 FoundResult = Matches[0].first; 5962 if (Complain) { 5963 CheckUnresolvedAccess(*this, OvlExpr, Matches[0].first); 5964 DiagnoseUseOfDecl(Matches[0].first, OvlExpr->getNameLoc()); 5965 } 5966 return cast<FunctionDecl>(Matches[0].second); 5967 } 5968 5969 // FIXME: We should probably return the same thing that BestViableFunction 5970 // returns (even if we issue the diagnostics here). 5971 Diag(From->getLocStart(), diag::err_addr_ovl_ambiguous) 5972 << Matches[0].second->getDeclName(); 5973 for (unsigned I = 0, E = Matches.size(); I != E; ++I) 5974 NoteOverloadCandidate(Matches[I].second); 5975 return 0; 5976} 5977 5978/// \brief Given an expression that refers to an overloaded function, try to 5979/// resolve that overloaded function expression down to a single function. 5980/// 5981/// This routine can only resolve template-ids that refer to a single function 5982/// template, where that template-id refers to a single template whose template 5983/// arguments are either provided by the template-id or have defaults, 5984/// as described in C++0x [temp.arg.explicit]p3. 5985FunctionDecl *Sema::ResolveSingleFunctionTemplateSpecialization(Expr *From) { 5986 // C++ [over.over]p1: 5987 // [...] [Note: any redundant set of parentheses surrounding the 5988 // overloaded function name is ignored (5.1). ] 5989 // C++ [over.over]p1: 5990 // [...] The overloaded function name can be preceded by the & 5991 // operator. 5992 5993 if (From->getType() != Context.OverloadTy) 5994 return 0; 5995 5996 OverloadExpr *OvlExpr = OverloadExpr::find(From).getPointer(); 5997 5998 // If we didn't actually find any template-ids, we're done. 5999 if (!OvlExpr->hasExplicitTemplateArgs()) 6000 return 0; 6001 6002 TemplateArgumentListInfo ExplicitTemplateArgs; 6003 OvlExpr->getExplicitTemplateArgs().copyInto(ExplicitTemplateArgs); 6004 6005 // Look through all of the overloaded functions, searching for one 6006 // whose type matches exactly. 6007 FunctionDecl *Matched = 0; 6008 for (UnresolvedSetIterator I = OvlExpr->decls_begin(), 6009 E = OvlExpr->decls_end(); I != E; ++I) { 6010 // C++0x [temp.arg.explicit]p3: 6011 // [...] In contexts where deduction is done and fails, or in contexts 6012 // where deduction is not done, if a template argument list is 6013 // specified and it, along with any default template arguments, 6014 // identifies a single function template specialization, then the 6015 // template-id is an lvalue for the function template specialization. 6016 FunctionTemplateDecl *FunctionTemplate = cast<FunctionTemplateDecl>(*I); 6017 6018 // C++ [over.over]p2: 6019 // If the name is a function template, template argument deduction is 6020 // done (14.8.2.2), and if the argument deduction succeeds, the 6021 // resulting template argument list is used to generate a single 6022 // function template specialization, which is added to the set of 6023 // overloaded functions considered. 6024 FunctionDecl *Specialization = 0; 6025 TemplateDeductionInfo Info(Context, OvlExpr->getNameLoc()); 6026 if (TemplateDeductionResult Result 6027 = DeduceTemplateArguments(FunctionTemplate, &ExplicitTemplateArgs, 6028 Specialization, Info)) { 6029 // FIXME: make a note of the failed deduction for diagnostics. 6030 (void)Result; 6031 continue; 6032 } 6033 6034 // Multiple matches; we can't resolve to a single declaration. 6035 if (Matched) 6036 return 0; 6037 6038 Matched = Specialization; 6039 } 6040 6041 return Matched; 6042} 6043 6044/// \brief Add a single candidate to the overload set. 6045static void AddOverloadedCallCandidate(Sema &S, 6046 DeclAccessPair FoundDecl, 6047 const TemplateArgumentListInfo *ExplicitTemplateArgs, 6048 Expr **Args, unsigned NumArgs, 6049 OverloadCandidateSet &CandidateSet, 6050 bool PartialOverloading) { 6051 NamedDecl *Callee = FoundDecl.getDecl(); 6052 if (isa<UsingShadowDecl>(Callee)) 6053 Callee = cast<UsingShadowDecl>(Callee)->getTargetDecl(); 6054 6055 if (FunctionDecl *Func = dyn_cast<FunctionDecl>(Callee)) { 6056 assert(!ExplicitTemplateArgs && "Explicit template arguments?"); 6057 S.AddOverloadCandidate(Func, FoundDecl, Args, NumArgs, CandidateSet, 6058 false, PartialOverloading); 6059 return; 6060 } 6061 6062 if (FunctionTemplateDecl *FuncTemplate 6063 = dyn_cast<FunctionTemplateDecl>(Callee)) { 6064 S.AddTemplateOverloadCandidate(FuncTemplate, FoundDecl, 6065 ExplicitTemplateArgs, 6066 Args, NumArgs, CandidateSet); 6067 return; 6068 } 6069 6070 assert(false && "unhandled case in overloaded call candidate"); 6071 6072 // do nothing? 6073} 6074 6075/// \brief Add the overload candidates named by callee and/or found by argument 6076/// dependent lookup to the given overload set. 6077void Sema::AddOverloadedCallCandidates(UnresolvedLookupExpr *ULE, 6078 Expr **Args, unsigned NumArgs, 6079 OverloadCandidateSet &CandidateSet, 6080 bool PartialOverloading) { 6081 6082#ifndef NDEBUG 6083 // Verify that ArgumentDependentLookup is consistent with the rules 6084 // in C++0x [basic.lookup.argdep]p3: 6085 // 6086 // Let X be the lookup set produced by unqualified lookup (3.4.1) 6087 // and let Y be the lookup set produced by argument dependent 6088 // lookup (defined as follows). If X contains 6089 // 6090 // -- a declaration of a class member, or 6091 // 6092 // -- a block-scope function declaration that is not a 6093 // using-declaration, or 6094 // 6095 // -- a declaration that is neither a function or a function 6096 // template 6097 // 6098 // then Y is empty. 6099 6100 if (ULE->requiresADL()) { 6101 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(), 6102 E = ULE->decls_end(); I != E; ++I) { 6103 assert(!(*I)->getDeclContext()->isRecord()); 6104 assert(isa<UsingShadowDecl>(*I) || 6105 !(*I)->getDeclContext()->isFunctionOrMethod()); 6106 assert((*I)->getUnderlyingDecl()->isFunctionOrFunctionTemplate()); 6107 } 6108 } 6109#endif 6110 6111 // It would be nice to avoid this copy. 6112 TemplateArgumentListInfo TABuffer; 6113 const TemplateArgumentListInfo *ExplicitTemplateArgs = 0; 6114 if (ULE->hasExplicitTemplateArgs()) { 6115 ULE->copyTemplateArgumentsInto(TABuffer); 6116 ExplicitTemplateArgs = &TABuffer; 6117 } 6118 6119 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(), 6120 E = ULE->decls_end(); I != E; ++I) 6121 AddOverloadedCallCandidate(*this, I.getPair(), ExplicitTemplateArgs, 6122 Args, NumArgs, CandidateSet, 6123 PartialOverloading); 6124 6125 if (ULE->requiresADL()) 6126 AddArgumentDependentLookupCandidates(ULE->getName(), /*Operator*/ false, 6127 Args, NumArgs, 6128 ExplicitTemplateArgs, 6129 CandidateSet, 6130 PartialOverloading); 6131} 6132 6133static Sema::OwningExprResult Destroy(Sema &SemaRef, Expr *Fn, 6134 Expr **Args, unsigned NumArgs) { 6135 Fn->Destroy(SemaRef.Context); 6136 for (unsigned Arg = 0; Arg < NumArgs; ++Arg) 6137 Args[Arg]->Destroy(SemaRef.Context); 6138 return SemaRef.ExprError(); 6139} 6140 6141/// Attempts to recover from a call where no functions were found. 6142/// 6143/// Returns true if new candidates were found. 6144static Sema::OwningExprResult 6145BuildRecoveryCallExpr(Sema &SemaRef, Scope *S, Expr *Fn, 6146 UnresolvedLookupExpr *ULE, 6147 SourceLocation LParenLoc, 6148 Expr **Args, unsigned NumArgs, 6149 SourceLocation *CommaLocs, 6150 SourceLocation RParenLoc) { 6151 6152 CXXScopeSpec SS; 6153 if (ULE->getQualifier()) { 6154 SS.setScopeRep(ULE->getQualifier()); 6155 SS.setRange(ULE->getQualifierRange()); 6156 } 6157 6158 TemplateArgumentListInfo TABuffer; 6159 const TemplateArgumentListInfo *ExplicitTemplateArgs = 0; 6160 if (ULE->hasExplicitTemplateArgs()) { 6161 ULE->copyTemplateArgumentsInto(TABuffer); 6162 ExplicitTemplateArgs = &TABuffer; 6163 } 6164 6165 LookupResult R(SemaRef, ULE->getName(), ULE->getNameLoc(), 6166 Sema::LookupOrdinaryName); 6167 if (SemaRef.DiagnoseEmptyLookup(S, SS, R, Sema::CTC_Expression)) 6168 return Destroy(SemaRef, Fn, Args, NumArgs); 6169 6170 assert(!R.empty() && "lookup results empty despite recovery"); 6171 6172 // Build an implicit member call if appropriate. Just drop the 6173 // casts and such from the call, we don't really care. 6174 Sema::OwningExprResult NewFn = SemaRef.ExprError(); 6175 if ((*R.begin())->isCXXClassMember()) 6176 NewFn = SemaRef.BuildPossibleImplicitMemberExpr(SS, R, ExplicitTemplateArgs); 6177 else if (ExplicitTemplateArgs) 6178 NewFn = SemaRef.BuildTemplateIdExpr(SS, R, false, *ExplicitTemplateArgs); 6179 else 6180 NewFn = SemaRef.BuildDeclarationNameExpr(SS, R, false); 6181 6182 if (NewFn.isInvalid()) 6183 return Destroy(SemaRef, Fn, Args, NumArgs); 6184 6185 Fn->Destroy(SemaRef.Context); 6186 6187 // This shouldn't cause an infinite loop because we're giving it 6188 // an expression with non-empty lookup results, which should never 6189 // end up here. 6190 return SemaRef.ActOnCallExpr(/*Scope*/ 0, move(NewFn), LParenLoc, 6191 Sema::MultiExprArg(SemaRef, (void**) Args, NumArgs), 6192 CommaLocs, RParenLoc); 6193} 6194 6195/// ResolveOverloadedCallFn - Given the call expression that calls Fn 6196/// (which eventually refers to the declaration Func) and the call 6197/// arguments Args/NumArgs, attempt to resolve the function call down 6198/// to a specific function. If overload resolution succeeds, returns 6199/// the function declaration produced by overload 6200/// resolution. Otherwise, emits diagnostics, deletes all of the 6201/// arguments and Fn, and returns NULL. 6202Sema::OwningExprResult 6203Sema::BuildOverloadedCallExpr(Scope *S, Expr *Fn, UnresolvedLookupExpr *ULE, 6204 SourceLocation LParenLoc, 6205 Expr **Args, unsigned NumArgs, 6206 SourceLocation *CommaLocs, 6207 SourceLocation RParenLoc) { 6208#ifndef NDEBUG 6209 if (ULE->requiresADL()) { 6210 // To do ADL, we must have found an unqualified name. 6211 assert(!ULE->getQualifier() && "qualified name with ADL"); 6212 6213 // We don't perform ADL for implicit declarations of builtins. 6214 // Verify that this was correctly set up. 6215 FunctionDecl *F; 6216 if (ULE->decls_begin() + 1 == ULE->decls_end() && 6217 (F = dyn_cast<FunctionDecl>(*ULE->decls_begin())) && 6218 F->getBuiltinID() && F->isImplicit()) 6219 assert(0 && "performing ADL for builtin"); 6220 6221 // We don't perform ADL in C. 6222 assert(getLangOptions().CPlusPlus && "ADL enabled in C"); 6223 } 6224#endif 6225 6226 OverloadCandidateSet CandidateSet(Fn->getExprLoc()); 6227 6228 // Add the functions denoted by the callee to the set of candidate 6229 // functions, including those from argument-dependent lookup. 6230 AddOverloadedCallCandidates(ULE, Args, NumArgs, CandidateSet); 6231 6232 // If we found nothing, try to recover. 6233 // AddRecoveryCallCandidates diagnoses the error itself, so we just 6234 // bailout out if it fails. 6235 if (CandidateSet.empty()) 6236 return BuildRecoveryCallExpr(*this, S, Fn, ULE, LParenLoc, Args, NumArgs, 6237 CommaLocs, RParenLoc); 6238 6239 OverloadCandidateSet::iterator Best; 6240 switch (BestViableFunction(CandidateSet, Fn->getLocStart(), Best)) { 6241 case OR_Success: { 6242 FunctionDecl *FDecl = Best->Function; 6243 CheckUnresolvedLookupAccess(ULE, Best->FoundDecl); 6244 DiagnoseUseOfDecl(Best->FoundDecl, ULE->getNameLoc()); 6245 Fn = FixOverloadedFunctionReference(Fn, Best->FoundDecl, FDecl); 6246 return BuildResolvedCallExpr(Fn, FDecl, LParenLoc, Args, NumArgs, RParenLoc); 6247 } 6248 6249 case OR_No_Viable_Function: 6250 Diag(Fn->getSourceRange().getBegin(), 6251 diag::err_ovl_no_viable_function_in_call) 6252 << ULE->getName() << Fn->getSourceRange(); 6253 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6254 break; 6255 6256 case OR_Ambiguous: 6257 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_ambiguous_call) 6258 << ULE->getName() << Fn->getSourceRange(); 6259 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, NumArgs); 6260 break; 6261 6262 case OR_Deleted: 6263 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_deleted_call) 6264 << Best->Function->isDeleted() 6265 << ULE->getName() 6266 << Fn->getSourceRange(); 6267 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6268 break; 6269 } 6270 6271 // Overload resolution failed. Destroy all of the subexpressions and 6272 // return NULL. 6273 Fn->Destroy(Context); 6274 for (unsigned Arg = 0; Arg < NumArgs; ++Arg) 6275 Args[Arg]->Destroy(Context); 6276 return ExprError(); 6277} 6278 6279static bool IsOverloaded(const UnresolvedSetImpl &Functions) { 6280 return Functions.size() > 1 || 6281 (Functions.size() == 1 && isa<FunctionTemplateDecl>(*Functions.begin())); 6282} 6283 6284/// \brief Create a unary operation that may resolve to an overloaded 6285/// operator. 6286/// 6287/// \param OpLoc The location of the operator itself (e.g., '*'). 6288/// 6289/// \param OpcIn The UnaryOperator::Opcode that describes this 6290/// operator. 6291/// 6292/// \param Functions The set of non-member functions that will be 6293/// considered by overload resolution. The caller needs to build this 6294/// set based on the context using, e.g., 6295/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 6296/// set should not contain any member functions; those will be added 6297/// by CreateOverloadedUnaryOp(). 6298/// 6299/// \param input The input argument. 6300Sema::OwningExprResult 6301Sema::CreateOverloadedUnaryOp(SourceLocation OpLoc, unsigned OpcIn, 6302 const UnresolvedSetImpl &Fns, 6303 ExprArg input) { 6304 UnaryOperator::Opcode Opc = static_cast<UnaryOperator::Opcode>(OpcIn); 6305 Expr *Input = (Expr *)input.get(); 6306 6307 OverloadedOperatorKind Op = UnaryOperator::getOverloadedOperator(Opc); 6308 assert(Op != OO_None && "Invalid opcode for overloaded unary operator"); 6309 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 6310 6311 Expr *Args[2] = { Input, 0 }; 6312 unsigned NumArgs = 1; 6313 6314 // For post-increment and post-decrement, add the implicit '0' as 6315 // the second argument, so that we know this is a post-increment or 6316 // post-decrement. 6317 if (Opc == UnaryOperator::PostInc || Opc == UnaryOperator::PostDec) { 6318 llvm::APSInt Zero(Context.getTypeSize(Context.IntTy), false); 6319 Args[1] = new (Context) IntegerLiteral(Zero, Context.IntTy, 6320 SourceLocation()); 6321 NumArgs = 2; 6322 } 6323 6324 if (Input->isTypeDependent()) { 6325 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 6326 UnresolvedLookupExpr *Fn 6327 = UnresolvedLookupExpr::Create(Context, /*Dependent*/ true, NamingClass, 6328 0, SourceRange(), OpName, OpLoc, 6329 /*ADL*/ true, IsOverloaded(Fns), 6330 Fns.begin(), Fns.end()); 6331 input.release(); 6332 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 6333 &Args[0], NumArgs, 6334 Context.DependentTy, 6335 OpLoc)); 6336 } 6337 6338 // Build an empty overload set. 6339 OverloadCandidateSet CandidateSet(OpLoc); 6340 6341 // Add the candidates from the given function set. 6342 AddFunctionCandidates(Fns, &Args[0], NumArgs, CandidateSet, false); 6343 6344 // Add operator candidates that are member functions. 6345 AddMemberOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 6346 6347 // Add candidates from ADL. 6348 AddArgumentDependentLookupCandidates(OpName, /*Operator*/ true, 6349 Args, NumArgs, 6350 /*ExplicitTemplateArgs*/ 0, 6351 CandidateSet); 6352 6353 // Add builtin operator candidates. 6354 AddBuiltinOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 6355 6356 // Perform overload resolution. 6357 OverloadCandidateSet::iterator Best; 6358 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 6359 case OR_Success: { 6360 // We found a built-in operator or an overloaded operator. 6361 FunctionDecl *FnDecl = Best->Function; 6362 6363 if (FnDecl) { 6364 // We matched an overloaded operator. Build a call to that 6365 // operator. 6366 6367 // Convert the arguments. 6368 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 6369 CheckMemberOperatorAccess(OpLoc, Args[0], 0, Best->FoundDecl); 6370 6371 if (PerformObjectArgumentInitialization(Input, /*Qualifier=*/0, 6372 Best->FoundDecl, Method)) 6373 return ExprError(); 6374 } else { 6375 // Convert the arguments. 6376 OwningExprResult InputInit 6377 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 6378 FnDecl->getParamDecl(0)), 6379 SourceLocation(), 6380 move(input)); 6381 if (InputInit.isInvalid()) 6382 return ExprError(); 6383 6384 input = move(InputInit); 6385 Input = (Expr *)input.get(); 6386 } 6387 6388 DiagnoseUseOfDecl(Best->FoundDecl, OpLoc); 6389 6390 // Determine the result type 6391 QualType ResultTy = FnDecl->getResultType().getNonReferenceType(); 6392 6393 // Build the actual expression node. 6394 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 6395 SourceLocation()); 6396 UsualUnaryConversions(FnExpr); 6397 6398 input.release(); 6399 Args[0] = Input; 6400 ExprOwningPtr<CallExpr> TheCall(this, 6401 new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 6402 Args, NumArgs, ResultTy, OpLoc)); 6403 6404 if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall.get(), 6405 FnDecl)) 6406 return ExprError(); 6407 6408 return MaybeBindToTemporary(TheCall.release()); 6409 } else { 6410 // We matched a built-in operator. Convert the arguments, then 6411 // break out so that we will build the appropriate built-in 6412 // operator node. 6413 if (PerformImplicitConversion(Input, Best->BuiltinTypes.ParamTypes[0], 6414 Best->Conversions[0], AA_Passing)) 6415 return ExprError(); 6416 6417 break; 6418 } 6419 } 6420 6421 case OR_No_Viable_Function: 6422 // No viable function; fall through to handling this as a 6423 // built-in operator, which will produce an error message for us. 6424 break; 6425 6426 case OR_Ambiguous: 6427 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 6428 << UnaryOperator::getOpcodeStr(Opc) 6429 << Input->getSourceRange(); 6430 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, NumArgs, 6431 UnaryOperator::getOpcodeStr(Opc), OpLoc); 6432 return ExprError(); 6433 6434 case OR_Deleted: 6435 Diag(OpLoc, diag::err_ovl_deleted_oper) 6436 << Best->Function->isDeleted() 6437 << UnaryOperator::getOpcodeStr(Opc) 6438 << Input->getSourceRange(); 6439 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6440 return ExprError(); 6441 } 6442 6443 // Either we found no viable overloaded operator or we matched a 6444 // built-in operator. In either case, fall through to trying to 6445 // build a built-in operation. 6446 input.release(); 6447 return CreateBuiltinUnaryOp(OpLoc, Opc, Owned(Input)); 6448} 6449 6450/// \brief Create a binary operation that may resolve to an overloaded 6451/// operator. 6452/// 6453/// \param OpLoc The location of the operator itself (e.g., '+'). 6454/// 6455/// \param OpcIn The BinaryOperator::Opcode that describes this 6456/// operator. 6457/// 6458/// \param Functions The set of non-member functions that will be 6459/// considered by overload resolution. The caller needs to build this 6460/// set based on the context using, e.g., 6461/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 6462/// set should not contain any member functions; those will be added 6463/// by CreateOverloadedBinOp(). 6464/// 6465/// \param LHS Left-hand argument. 6466/// \param RHS Right-hand argument. 6467Sema::OwningExprResult 6468Sema::CreateOverloadedBinOp(SourceLocation OpLoc, 6469 unsigned OpcIn, 6470 const UnresolvedSetImpl &Fns, 6471 Expr *LHS, Expr *RHS) { 6472 Expr *Args[2] = { LHS, RHS }; 6473 LHS=RHS=0; //Please use only Args instead of LHS/RHS couple 6474 6475 BinaryOperator::Opcode Opc = static_cast<BinaryOperator::Opcode>(OpcIn); 6476 OverloadedOperatorKind Op = BinaryOperator::getOverloadedOperator(Opc); 6477 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 6478 6479 // If either side is type-dependent, create an appropriate dependent 6480 // expression. 6481 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 6482 if (Fns.empty()) { 6483 // If there are no functions to store, just build a dependent 6484 // BinaryOperator or CompoundAssignment. 6485 if (Opc <= BinaryOperator::Assign || Opc > BinaryOperator::OrAssign) 6486 return Owned(new (Context) BinaryOperator(Args[0], Args[1], Opc, 6487 Context.DependentTy, OpLoc)); 6488 6489 return Owned(new (Context) CompoundAssignOperator(Args[0], Args[1], Opc, 6490 Context.DependentTy, 6491 Context.DependentTy, 6492 Context.DependentTy, 6493 OpLoc)); 6494 } 6495 6496 // FIXME: save results of ADL from here? 6497 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 6498 UnresolvedLookupExpr *Fn 6499 = UnresolvedLookupExpr::Create(Context, /*Dependent*/ true, NamingClass, 6500 0, SourceRange(), OpName, OpLoc, 6501 /*ADL*/ true, IsOverloaded(Fns), 6502 Fns.begin(), Fns.end()); 6503 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 6504 Args, 2, 6505 Context.DependentTy, 6506 OpLoc)); 6507 } 6508 6509 // If this is the .* operator, which is not overloadable, just 6510 // create a built-in binary operator. 6511 if (Opc == BinaryOperator::PtrMemD) 6512 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 6513 6514 // If this is the assignment operator, we only perform overload resolution 6515 // if the left-hand side is a class or enumeration type. This is actually 6516 // a hack. The standard requires that we do overload resolution between the 6517 // various built-in candidates, but as DR507 points out, this can lead to 6518 // problems. So we do it this way, which pretty much follows what GCC does. 6519 // Note that we go the traditional code path for compound assignment forms. 6520 if (Opc==BinaryOperator::Assign && !Args[0]->getType()->isOverloadableType()) 6521 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 6522 6523 // Build an empty overload set. 6524 OverloadCandidateSet CandidateSet(OpLoc); 6525 6526 // Add the candidates from the given function set. 6527 AddFunctionCandidates(Fns, Args, 2, CandidateSet, false); 6528 6529 // Add operator candidates that are member functions. 6530 AddMemberOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 6531 6532 // Add candidates from ADL. 6533 AddArgumentDependentLookupCandidates(OpName, /*Operator*/ true, 6534 Args, 2, 6535 /*ExplicitTemplateArgs*/ 0, 6536 CandidateSet); 6537 6538 // Add builtin operator candidates. 6539 AddBuiltinOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 6540 6541 // Perform overload resolution. 6542 OverloadCandidateSet::iterator Best; 6543 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 6544 case OR_Success: { 6545 // We found a built-in operator or an overloaded operator. 6546 FunctionDecl *FnDecl = Best->Function; 6547 6548 if (FnDecl) { 6549 // We matched an overloaded operator. Build a call to that 6550 // operator. 6551 6552 // Convert the arguments. 6553 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 6554 // Best->Access is only meaningful for class members. 6555 CheckMemberOperatorAccess(OpLoc, Args[0], Args[1], Best->FoundDecl); 6556 6557 OwningExprResult Arg1 6558 = PerformCopyInitialization( 6559 InitializedEntity::InitializeParameter( 6560 FnDecl->getParamDecl(0)), 6561 SourceLocation(), 6562 Owned(Args[1])); 6563 if (Arg1.isInvalid()) 6564 return ExprError(); 6565 6566 if (PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/0, 6567 Best->FoundDecl, Method)) 6568 return ExprError(); 6569 6570 Args[1] = RHS = Arg1.takeAs<Expr>(); 6571 } else { 6572 // Convert the arguments. 6573 OwningExprResult Arg0 6574 = PerformCopyInitialization( 6575 InitializedEntity::InitializeParameter( 6576 FnDecl->getParamDecl(0)), 6577 SourceLocation(), 6578 Owned(Args[0])); 6579 if (Arg0.isInvalid()) 6580 return ExprError(); 6581 6582 OwningExprResult Arg1 6583 = PerformCopyInitialization( 6584 InitializedEntity::InitializeParameter( 6585 FnDecl->getParamDecl(1)), 6586 SourceLocation(), 6587 Owned(Args[1])); 6588 if (Arg1.isInvalid()) 6589 return ExprError(); 6590 Args[0] = LHS = Arg0.takeAs<Expr>(); 6591 Args[1] = RHS = Arg1.takeAs<Expr>(); 6592 } 6593 6594 DiagnoseUseOfDecl(Best->FoundDecl, OpLoc); 6595 6596 // Determine the result type 6597 QualType ResultTy 6598 = FnDecl->getType()->getAs<FunctionType>()->getResultType(); 6599 ResultTy = ResultTy.getNonReferenceType(); 6600 6601 // Build the actual expression node. 6602 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 6603 OpLoc); 6604 UsualUnaryConversions(FnExpr); 6605 6606 ExprOwningPtr<CXXOperatorCallExpr> 6607 TheCall(this, new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 6608 Args, 2, ResultTy, 6609 OpLoc)); 6610 6611 if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall.get(), 6612 FnDecl)) 6613 return ExprError(); 6614 6615 return MaybeBindToTemporary(TheCall.release()); 6616 } else { 6617 // We matched a built-in operator. Convert the arguments, then 6618 // break out so that we will build the appropriate built-in 6619 // operator node. 6620 if (PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 6621 Best->Conversions[0], AA_Passing) || 6622 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 6623 Best->Conversions[1], AA_Passing)) 6624 return ExprError(); 6625 6626 break; 6627 } 6628 } 6629 6630 case OR_No_Viable_Function: { 6631 // C++ [over.match.oper]p9: 6632 // If the operator is the operator , [...] and there are no 6633 // viable functions, then the operator is assumed to be the 6634 // built-in operator and interpreted according to clause 5. 6635 if (Opc == BinaryOperator::Comma) 6636 break; 6637 6638 // For class as left operand for assignment or compound assigment operator 6639 // do not fall through to handling in built-in, but report that no overloaded 6640 // assignment operator found 6641 OwningExprResult Result = ExprError(); 6642 if (Args[0]->getType()->isRecordType() && 6643 Opc >= BinaryOperator::Assign && Opc <= BinaryOperator::OrAssign) { 6644 Diag(OpLoc, diag::err_ovl_no_viable_oper) 6645 << BinaryOperator::getOpcodeStr(Opc) 6646 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 6647 } else { 6648 // No viable function; try to create a built-in operation, which will 6649 // produce an error. Then, show the non-viable candidates. 6650 Result = CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 6651 } 6652 assert(Result.isInvalid() && 6653 "C++ binary operator overloading is missing candidates!"); 6654 if (Result.isInvalid()) 6655 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2, 6656 BinaryOperator::getOpcodeStr(Opc), OpLoc); 6657 return move(Result); 6658 } 6659 6660 case OR_Ambiguous: 6661 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 6662 << BinaryOperator::getOpcodeStr(Opc) 6663 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 6664 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, 2, 6665 BinaryOperator::getOpcodeStr(Opc), OpLoc); 6666 return ExprError(); 6667 6668 case OR_Deleted: 6669 Diag(OpLoc, diag::err_ovl_deleted_oper) 6670 << Best->Function->isDeleted() 6671 << BinaryOperator::getOpcodeStr(Opc) 6672 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 6673 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2); 6674 return ExprError(); 6675 } 6676 6677 // We matched a built-in operator; build it. 6678 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 6679} 6680 6681Action::OwningExprResult 6682Sema::CreateOverloadedArraySubscriptExpr(SourceLocation LLoc, 6683 SourceLocation RLoc, 6684 ExprArg Base, ExprArg Idx) { 6685 Expr *Args[2] = { static_cast<Expr*>(Base.get()), 6686 static_cast<Expr*>(Idx.get()) }; 6687 DeclarationName OpName = 6688 Context.DeclarationNames.getCXXOperatorName(OO_Subscript); 6689 6690 // If either side is type-dependent, create an appropriate dependent 6691 // expression. 6692 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 6693 6694 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 6695 UnresolvedLookupExpr *Fn 6696 = UnresolvedLookupExpr::Create(Context, /*Dependent*/ true, NamingClass, 6697 0, SourceRange(), OpName, LLoc, 6698 /*ADL*/ true, /*Overloaded*/ false, 6699 UnresolvedSetIterator(), 6700 UnresolvedSetIterator()); 6701 // Can't add any actual overloads yet 6702 6703 Base.release(); 6704 Idx.release(); 6705 return Owned(new (Context) CXXOperatorCallExpr(Context, OO_Subscript, Fn, 6706 Args, 2, 6707 Context.DependentTy, 6708 RLoc)); 6709 } 6710 6711 // Build an empty overload set. 6712 OverloadCandidateSet CandidateSet(LLoc); 6713 6714 // Subscript can only be overloaded as a member function. 6715 6716 // Add operator candidates that are member functions. 6717 AddMemberOperatorCandidates(OO_Subscript, LLoc, Args, 2, CandidateSet); 6718 6719 // Add builtin operator candidates. 6720 AddBuiltinOperatorCandidates(OO_Subscript, LLoc, Args, 2, CandidateSet); 6721 6722 // Perform overload resolution. 6723 OverloadCandidateSet::iterator Best; 6724 switch (BestViableFunction(CandidateSet, LLoc, Best)) { 6725 case OR_Success: { 6726 // We found a built-in operator or an overloaded operator. 6727 FunctionDecl *FnDecl = Best->Function; 6728 6729 if (FnDecl) { 6730 // We matched an overloaded operator. Build a call to that 6731 // operator. 6732 6733 CheckMemberOperatorAccess(LLoc, Args[0], Args[1], Best->FoundDecl); 6734 DiagnoseUseOfDecl(Best->FoundDecl, LLoc); 6735 6736 // Convert the arguments. 6737 CXXMethodDecl *Method = cast<CXXMethodDecl>(FnDecl); 6738 if (PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/0, 6739 Best->FoundDecl, Method)) 6740 return ExprError(); 6741 6742 // Convert the arguments. 6743 OwningExprResult InputInit 6744 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 6745 FnDecl->getParamDecl(0)), 6746 SourceLocation(), 6747 Owned(Args[1])); 6748 if (InputInit.isInvalid()) 6749 return ExprError(); 6750 6751 Args[1] = InputInit.takeAs<Expr>(); 6752 6753 // Determine the result type 6754 QualType ResultTy 6755 = FnDecl->getType()->getAs<FunctionType>()->getResultType(); 6756 ResultTy = ResultTy.getNonReferenceType(); 6757 6758 // Build the actual expression node. 6759 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 6760 LLoc); 6761 UsualUnaryConversions(FnExpr); 6762 6763 Base.release(); 6764 Idx.release(); 6765 ExprOwningPtr<CXXOperatorCallExpr> 6766 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Subscript, 6767 FnExpr, Args, 2, 6768 ResultTy, RLoc)); 6769 6770 if (CheckCallReturnType(FnDecl->getResultType(), LLoc, TheCall.get(), 6771 FnDecl)) 6772 return ExprError(); 6773 6774 return MaybeBindToTemporary(TheCall.release()); 6775 } else { 6776 // We matched a built-in operator. Convert the arguments, then 6777 // break out so that we will build the appropriate built-in 6778 // operator node. 6779 if (PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 6780 Best->Conversions[0], AA_Passing) || 6781 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 6782 Best->Conversions[1], AA_Passing)) 6783 return ExprError(); 6784 6785 break; 6786 } 6787 } 6788 6789 case OR_No_Viable_Function: { 6790 if (CandidateSet.empty()) 6791 Diag(LLoc, diag::err_ovl_no_oper) 6792 << Args[0]->getType() << /*subscript*/ 0 6793 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 6794 else 6795 Diag(LLoc, diag::err_ovl_no_viable_subscript) 6796 << Args[0]->getType() 6797 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 6798 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2, 6799 "[]", LLoc); 6800 return ExprError(); 6801 } 6802 6803 case OR_Ambiguous: 6804 Diag(LLoc, diag::err_ovl_ambiguous_oper) 6805 << "[]" << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 6806 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, 2, 6807 "[]", LLoc); 6808 return ExprError(); 6809 6810 case OR_Deleted: 6811 Diag(LLoc, diag::err_ovl_deleted_oper) 6812 << Best->Function->isDeleted() << "[]" 6813 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 6814 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2, 6815 "[]", LLoc); 6816 return ExprError(); 6817 } 6818 6819 // We matched a built-in operator; build it. 6820 Base.release(); 6821 Idx.release(); 6822 return CreateBuiltinArraySubscriptExpr(Owned(Args[0]), LLoc, 6823 Owned(Args[1]), RLoc); 6824} 6825 6826/// BuildCallToMemberFunction - Build a call to a member 6827/// function. MemExpr is the expression that refers to the member 6828/// function (and includes the object parameter), Args/NumArgs are the 6829/// arguments to the function call (not including the object 6830/// parameter). The caller needs to validate that the member 6831/// expression refers to a member function or an overloaded member 6832/// function. 6833Sema::OwningExprResult 6834Sema::BuildCallToMemberFunction(Scope *S, Expr *MemExprE, 6835 SourceLocation LParenLoc, Expr **Args, 6836 unsigned NumArgs, SourceLocation *CommaLocs, 6837 SourceLocation RParenLoc) { 6838 // Dig out the member expression. This holds both the object 6839 // argument and the member function we're referring to. 6840 Expr *NakedMemExpr = MemExprE->IgnoreParens(); 6841 6842 MemberExpr *MemExpr; 6843 CXXMethodDecl *Method = 0; 6844 DeclAccessPair FoundDecl = DeclAccessPair::make(0, AS_public); 6845 NestedNameSpecifier *Qualifier = 0; 6846 if (isa<MemberExpr>(NakedMemExpr)) { 6847 MemExpr = cast<MemberExpr>(NakedMemExpr); 6848 Method = cast<CXXMethodDecl>(MemExpr->getMemberDecl()); 6849 FoundDecl = MemExpr->getFoundDecl(); 6850 Qualifier = MemExpr->getQualifier(); 6851 } else { 6852 UnresolvedMemberExpr *UnresExpr = cast<UnresolvedMemberExpr>(NakedMemExpr); 6853 Qualifier = UnresExpr->getQualifier(); 6854 6855 QualType ObjectType = UnresExpr->getBaseType(); 6856 6857 // Add overload candidates 6858 OverloadCandidateSet CandidateSet(UnresExpr->getMemberLoc()); 6859 6860 // FIXME: avoid copy. 6861 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 6862 if (UnresExpr->hasExplicitTemplateArgs()) { 6863 UnresExpr->copyTemplateArgumentsInto(TemplateArgsBuffer); 6864 TemplateArgs = &TemplateArgsBuffer; 6865 } 6866 6867 for (UnresolvedMemberExpr::decls_iterator I = UnresExpr->decls_begin(), 6868 E = UnresExpr->decls_end(); I != E; ++I) { 6869 6870 NamedDecl *Func = *I; 6871 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(Func->getDeclContext()); 6872 if (isa<UsingShadowDecl>(Func)) 6873 Func = cast<UsingShadowDecl>(Func)->getTargetDecl(); 6874 6875 if ((Method = dyn_cast<CXXMethodDecl>(Func))) { 6876 // If explicit template arguments were provided, we can't call a 6877 // non-template member function. 6878 if (TemplateArgs) 6879 continue; 6880 6881 AddMethodCandidate(Method, I.getPair(), ActingDC, ObjectType, 6882 Args, NumArgs, 6883 CandidateSet, /*SuppressUserConversions=*/false); 6884 } else { 6885 AddMethodTemplateCandidate(cast<FunctionTemplateDecl>(Func), 6886 I.getPair(), ActingDC, TemplateArgs, 6887 ObjectType, Args, NumArgs, 6888 CandidateSet, 6889 /*SuppressUsedConversions=*/false); 6890 } 6891 } 6892 6893 DeclarationName DeclName = UnresExpr->getMemberName(); 6894 6895 OverloadCandidateSet::iterator Best; 6896 switch (BestViableFunction(CandidateSet, UnresExpr->getLocStart(), Best)) { 6897 case OR_Success: 6898 Method = cast<CXXMethodDecl>(Best->Function); 6899 FoundDecl = Best->FoundDecl; 6900 CheckUnresolvedMemberAccess(UnresExpr, Best->FoundDecl); 6901 DiagnoseUseOfDecl(Best->FoundDecl, UnresExpr->getNameLoc()); 6902 break; 6903 6904 case OR_No_Viable_Function: 6905 Diag(UnresExpr->getMemberLoc(), 6906 diag::err_ovl_no_viable_member_function_in_call) 6907 << DeclName << MemExprE->getSourceRange(); 6908 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6909 // FIXME: Leaking incoming expressions! 6910 return ExprError(); 6911 6912 case OR_Ambiguous: 6913 Diag(UnresExpr->getMemberLoc(), diag::err_ovl_ambiguous_member_call) 6914 << DeclName << MemExprE->getSourceRange(); 6915 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6916 // FIXME: Leaking incoming expressions! 6917 return ExprError(); 6918 6919 case OR_Deleted: 6920 Diag(UnresExpr->getMemberLoc(), diag::err_ovl_deleted_member_call) 6921 << Best->Function->isDeleted() 6922 << DeclName << MemExprE->getSourceRange(); 6923 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6924 // FIXME: Leaking incoming expressions! 6925 return ExprError(); 6926 } 6927 6928 MemExprE = FixOverloadedFunctionReference(MemExprE, FoundDecl, Method); 6929 6930 // If overload resolution picked a static member, build a 6931 // non-member call based on that function. 6932 if (Method->isStatic()) { 6933 return BuildResolvedCallExpr(MemExprE, Method, LParenLoc, 6934 Args, NumArgs, RParenLoc); 6935 } 6936 6937 MemExpr = cast<MemberExpr>(MemExprE->IgnoreParens()); 6938 } 6939 6940 assert(Method && "Member call to something that isn't a method?"); 6941 ExprOwningPtr<CXXMemberCallExpr> 6942 TheCall(this, new (Context) CXXMemberCallExpr(Context, MemExprE, Args, 6943 NumArgs, 6944 Method->getResultType().getNonReferenceType(), 6945 RParenLoc)); 6946 6947 // Check for a valid return type. 6948 if (CheckCallReturnType(Method->getResultType(), MemExpr->getMemberLoc(), 6949 TheCall.get(), Method)) 6950 return ExprError(); 6951 6952 // Convert the object argument (for a non-static member function call). 6953 // We only need to do this if there was actually an overload; otherwise 6954 // it was done at lookup. 6955 Expr *ObjectArg = MemExpr->getBase(); 6956 if (!Method->isStatic() && 6957 PerformObjectArgumentInitialization(ObjectArg, Qualifier, 6958 FoundDecl, Method)) 6959 return ExprError(); 6960 MemExpr->setBase(ObjectArg); 6961 6962 // Convert the rest of the arguments 6963 const FunctionProtoType *Proto = Method->getType()->getAs<FunctionProtoType>(); 6964 if (ConvertArgumentsForCall(&*TheCall, MemExpr, Method, Proto, Args, NumArgs, 6965 RParenLoc)) 6966 return ExprError(); 6967 6968 if (CheckFunctionCall(Method, TheCall.get())) 6969 return ExprError(); 6970 6971 return MaybeBindToTemporary(TheCall.release()); 6972} 6973 6974/// BuildCallToObjectOfClassType - Build a call to an object of class 6975/// type (C++ [over.call.object]), which can end up invoking an 6976/// overloaded function call operator (@c operator()) or performing a 6977/// user-defined conversion on the object argument. 6978Sema::ExprResult 6979Sema::BuildCallToObjectOfClassType(Scope *S, Expr *Object, 6980 SourceLocation LParenLoc, 6981 Expr **Args, unsigned NumArgs, 6982 SourceLocation *CommaLocs, 6983 SourceLocation RParenLoc) { 6984 assert(Object->getType()->isRecordType() && "Requires object type argument"); 6985 const RecordType *Record = Object->getType()->getAs<RecordType>(); 6986 6987 // C++ [over.call.object]p1: 6988 // If the primary-expression E in the function call syntax 6989 // evaluates to a class object of type "cv T", then the set of 6990 // candidate functions includes at least the function call 6991 // operators of T. The function call operators of T are obtained by 6992 // ordinary lookup of the name operator() in the context of 6993 // (E).operator(). 6994 OverloadCandidateSet CandidateSet(LParenLoc); 6995 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Call); 6996 6997 if (RequireCompleteType(LParenLoc, Object->getType(), 6998 PDiag(diag::err_incomplete_object_call) 6999 << Object->getSourceRange())) 7000 return true; 7001 7002 LookupResult R(*this, OpName, LParenLoc, LookupOrdinaryName); 7003 LookupQualifiedName(R, Record->getDecl()); 7004 R.suppressDiagnostics(); 7005 7006 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 7007 Oper != OperEnd; ++Oper) { 7008 AddMethodCandidate(Oper.getPair(), Object->getType(), 7009 Args, NumArgs, CandidateSet, 7010 /*SuppressUserConversions=*/ false); 7011 } 7012 7013 // C++ [over.call.object]p2: 7014 // In addition, for each conversion function declared in T of the 7015 // form 7016 // 7017 // operator conversion-type-id () cv-qualifier; 7018 // 7019 // where cv-qualifier is the same cv-qualification as, or a 7020 // greater cv-qualification than, cv, and where conversion-type-id 7021 // denotes the type "pointer to function of (P1,...,Pn) returning 7022 // R", or the type "reference to pointer to function of 7023 // (P1,...,Pn) returning R", or the type "reference to function 7024 // of (P1,...,Pn) returning R", a surrogate call function [...] 7025 // is also considered as a candidate function. Similarly, 7026 // surrogate call functions are added to the set of candidate 7027 // functions for each conversion function declared in an 7028 // accessible base class provided the function is not hidden 7029 // within T by another intervening declaration. 7030 const UnresolvedSetImpl *Conversions 7031 = cast<CXXRecordDecl>(Record->getDecl())->getVisibleConversionFunctions(); 7032 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 7033 E = Conversions->end(); I != E; ++I) { 7034 NamedDecl *D = *I; 7035 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext()); 7036 if (isa<UsingShadowDecl>(D)) 7037 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 7038 7039 // Skip over templated conversion functions; they aren't 7040 // surrogates. 7041 if (isa<FunctionTemplateDecl>(D)) 7042 continue; 7043 7044 CXXConversionDecl *Conv = cast<CXXConversionDecl>(D); 7045 7046 // Strip the reference type (if any) and then the pointer type (if 7047 // any) to get down to what might be a function type. 7048 QualType ConvType = Conv->getConversionType().getNonReferenceType(); 7049 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 7050 ConvType = ConvPtrType->getPointeeType(); 7051 7052 if (const FunctionProtoType *Proto = ConvType->getAs<FunctionProtoType>()) 7053 AddSurrogateCandidate(Conv, I.getPair(), ActingContext, Proto, 7054 Object->getType(), Args, NumArgs, 7055 CandidateSet); 7056 } 7057 7058 // Perform overload resolution. 7059 OverloadCandidateSet::iterator Best; 7060 switch (BestViableFunction(CandidateSet, Object->getLocStart(), Best)) { 7061 case OR_Success: 7062 // Overload resolution succeeded; we'll build the appropriate call 7063 // below. 7064 break; 7065 7066 case OR_No_Viable_Function: 7067 if (CandidateSet.empty()) 7068 Diag(Object->getSourceRange().getBegin(), diag::err_ovl_no_oper) 7069 << Object->getType() << /*call*/ 1 7070 << Object->getSourceRange(); 7071 else 7072 Diag(Object->getSourceRange().getBegin(), 7073 diag::err_ovl_no_viable_object_call) 7074 << Object->getType() << Object->getSourceRange(); 7075 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 7076 break; 7077 7078 case OR_Ambiguous: 7079 Diag(Object->getSourceRange().getBegin(), 7080 diag::err_ovl_ambiguous_object_call) 7081 << Object->getType() << Object->getSourceRange(); 7082 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, NumArgs); 7083 break; 7084 7085 case OR_Deleted: 7086 Diag(Object->getSourceRange().getBegin(), 7087 diag::err_ovl_deleted_object_call) 7088 << Best->Function->isDeleted() 7089 << Object->getType() << Object->getSourceRange(); 7090 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 7091 break; 7092 } 7093 7094 if (Best == CandidateSet.end()) { 7095 // We had an error; delete all of the subexpressions and return 7096 // the error. 7097 Object->Destroy(Context); 7098 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 7099 Args[ArgIdx]->Destroy(Context); 7100 return true; 7101 } 7102 7103 if (Best->Function == 0) { 7104 // Since there is no function declaration, this is one of the 7105 // surrogate candidates. Dig out the conversion function. 7106 CXXConversionDecl *Conv 7107 = cast<CXXConversionDecl>( 7108 Best->Conversions[0].UserDefined.ConversionFunction); 7109 7110 CheckMemberOperatorAccess(LParenLoc, Object, 0, Best->FoundDecl); 7111 DiagnoseUseOfDecl(Best->FoundDecl, LParenLoc); 7112 7113 // We selected one of the surrogate functions that converts the 7114 // object parameter to a function pointer. Perform the conversion 7115 // on the object argument, then let ActOnCallExpr finish the job. 7116 7117 // Create an implicit member expr to refer to the conversion operator. 7118 // and then call it. 7119 CXXMemberCallExpr *CE = BuildCXXMemberCallExpr(Object, Best->FoundDecl, 7120 Conv); 7121 7122 return ActOnCallExpr(S, ExprArg(*this, CE), LParenLoc, 7123 MultiExprArg(*this, (ExprTy**)Args, NumArgs), 7124 CommaLocs, RParenLoc).result(); 7125 } 7126 7127 CheckMemberOperatorAccess(LParenLoc, Object, 0, Best->FoundDecl); 7128 DiagnoseUseOfDecl(Best->FoundDecl, LParenLoc); 7129 7130 // We found an overloaded operator(). Build a CXXOperatorCallExpr 7131 // that calls this method, using Object for the implicit object 7132 // parameter and passing along the remaining arguments. 7133 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 7134 const FunctionProtoType *Proto = Method->getType()->getAs<FunctionProtoType>(); 7135 7136 unsigned NumArgsInProto = Proto->getNumArgs(); 7137 unsigned NumArgsToCheck = NumArgs; 7138 7139 // Build the full argument list for the method call (the 7140 // implicit object parameter is placed at the beginning of the 7141 // list). 7142 Expr **MethodArgs; 7143 if (NumArgs < NumArgsInProto) { 7144 NumArgsToCheck = NumArgsInProto; 7145 MethodArgs = new Expr*[NumArgsInProto + 1]; 7146 } else { 7147 MethodArgs = new Expr*[NumArgs + 1]; 7148 } 7149 MethodArgs[0] = Object; 7150 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 7151 MethodArgs[ArgIdx + 1] = Args[ArgIdx]; 7152 7153 Expr *NewFn = new (Context) DeclRefExpr(Method, Method->getType(), 7154 SourceLocation()); 7155 UsualUnaryConversions(NewFn); 7156 7157 // Once we've built TheCall, all of the expressions are properly 7158 // owned. 7159 QualType ResultTy = Method->getResultType().getNonReferenceType(); 7160 ExprOwningPtr<CXXOperatorCallExpr> 7161 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Call, NewFn, 7162 MethodArgs, NumArgs + 1, 7163 ResultTy, RParenLoc)); 7164 delete [] MethodArgs; 7165 7166 if (CheckCallReturnType(Method->getResultType(), LParenLoc, TheCall.get(), 7167 Method)) 7168 return true; 7169 7170 // We may have default arguments. If so, we need to allocate more 7171 // slots in the call for them. 7172 if (NumArgs < NumArgsInProto) 7173 TheCall->setNumArgs(Context, NumArgsInProto + 1); 7174 else if (NumArgs > NumArgsInProto) 7175 NumArgsToCheck = NumArgsInProto; 7176 7177 bool IsError = false; 7178 7179 // Initialize the implicit object parameter. 7180 IsError |= PerformObjectArgumentInitialization(Object, /*Qualifier=*/0, 7181 Best->FoundDecl, Method); 7182 TheCall->setArg(0, Object); 7183 7184 7185 // Check the argument types. 7186 for (unsigned i = 0; i != NumArgsToCheck; i++) { 7187 Expr *Arg; 7188 if (i < NumArgs) { 7189 Arg = Args[i]; 7190 7191 // Pass the argument. 7192 7193 OwningExprResult InputInit 7194 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 7195 Method->getParamDecl(i)), 7196 SourceLocation(), Owned(Arg)); 7197 7198 IsError |= InputInit.isInvalid(); 7199 Arg = InputInit.takeAs<Expr>(); 7200 } else { 7201 OwningExprResult DefArg 7202 = BuildCXXDefaultArgExpr(LParenLoc, Method, Method->getParamDecl(i)); 7203 if (DefArg.isInvalid()) { 7204 IsError = true; 7205 break; 7206 } 7207 7208 Arg = DefArg.takeAs<Expr>(); 7209 } 7210 7211 TheCall->setArg(i + 1, Arg); 7212 } 7213 7214 // If this is a variadic call, handle args passed through "...". 7215 if (Proto->isVariadic()) { 7216 // Promote the arguments (C99 6.5.2.2p7). 7217 for (unsigned i = NumArgsInProto; i != NumArgs; i++) { 7218 Expr *Arg = Args[i]; 7219 IsError |= DefaultVariadicArgumentPromotion(Arg, VariadicMethod, 0); 7220 TheCall->setArg(i + 1, Arg); 7221 } 7222 } 7223 7224 if (IsError) return true; 7225 7226 if (CheckFunctionCall(Method, TheCall.get())) 7227 return true; 7228 7229 return MaybeBindToTemporary(TheCall.release()).result(); 7230} 7231 7232/// BuildOverloadedArrowExpr - Build a call to an overloaded @c operator-> 7233/// (if one exists), where @c Base is an expression of class type and 7234/// @c Member is the name of the member we're trying to find. 7235Sema::OwningExprResult 7236Sema::BuildOverloadedArrowExpr(Scope *S, ExprArg BaseIn, SourceLocation OpLoc) { 7237 Expr *Base = static_cast<Expr *>(BaseIn.get()); 7238 assert(Base->getType()->isRecordType() && "left-hand side must have class type"); 7239 7240 SourceLocation Loc = Base->getExprLoc(); 7241 7242 // C++ [over.ref]p1: 7243 // 7244 // [...] An expression x->m is interpreted as (x.operator->())->m 7245 // for a class object x of type T if T::operator->() exists and if 7246 // the operator is selected as the best match function by the 7247 // overload resolution mechanism (13.3). 7248 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Arrow); 7249 OverloadCandidateSet CandidateSet(Loc); 7250 const RecordType *BaseRecord = Base->getType()->getAs<RecordType>(); 7251 7252 if (RequireCompleteType(Loc, Base->getType(), 7253 PDiag(diag::err_typecheck_incomplete_tag) 7254 << Base->getSourceRange())) 7255 return ExprError(); 7256 7257 LookupResult R(*this, OpName, OpLoc, LookupOrdinaryName); 7258 LookupQualifiedName(R, BaseRecord->getDecl()); 7259 R.suppressDiagnostics(); 7260 7261 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 7262 Oper != OperEnd; ++Oper) { 7263 AddMethodCandidate(Oper.getPair(), Base->getType(), 0, 0, CandidateSet, 7264 /*SuppressUserConversions=*/false); 7265 } 7266 7267 // Perform overload resolution. 7268 OverloadCandidateSet::iterator Best; 7269 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 7270 case OR_Success: 7271 // Overload resolution succeeded; we'll build the call below. 7272 break; 7273 7274 case OR_No_Viable_Function: 7275 if (CandidateSet.empty()) 7276 Diag(OpLoc, diag::err_typecheck_member_reference_arrow) 7277 << Base->getType() << Base->getSourceRange(); 7278 else 7279 Diag(OpLoc, diag::err_ovl_no_viable_oper) 7280 << "operator->" << Base->getSourceRange(); 7281 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, &Base, 1); 7282 return ExprError(); 7283 7284 case OR_Ambiguous: 7285 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 7286 << "->" << Base->getSourceRange(); 7287 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, &Base, 1); 7288 return ExprError(); 7289 7290 case OR_Deleted: 7291 Diag(OpLoc, diag::err_ovl_deleted_oper) 7292 << Best->Function->isDeleted() 7293 << "->" << Base->getSourceRange(); 7294 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, &Base, 1); 7295 return ExprError(); 7296 } 7297 7298 CheckMemberOperatorAccess(OpLoc, Base, 0, Best->FoundDecl); 7299 DiagnoseUseOfDecl(Best->FoundDecl, OpLoc); 7300 7301 // Convert the object parameter. 7302 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 7303 if (PerformObjectArgumentInitialization(Base, /*Qualifier=*/0, 7304 Best->FoundDecl, Method)) 7305 return ExprError(); 7306 7307 // No concerns about early exits now. 7308 BaseIn.release(); 7309 7310 // Build the operator call. 7311 Expr *FnExpr = new (Context) DeclRefExpr(Method, Method->getType(), 7312 SourceLocation()); 7313 UsualUnaryConversions(FnExpr); 7314 7315 QualType ResultTy = Method->getResultType().getNonReferenceType(); 7316 ExprOwningPtr<CXXOperatorCallExpr> 7317 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Arrow, FnExpr, 7318 &Base, 1, ResultTy, OpLoc)); 7319 7320 if (CheckCallReturnType(Method->getResultType(), OpLoc, TheCall.get(), 7321 Method)) 7322 return ExprError(); 7323 return move(TheCall); 7324} 7325 7326/// FixOverloadedFunctionReference - E is an expression that refers to 7327/// a C++ overloaded function (possibly with some parentheses and 7328/// perhaps a '&' around it). We have resolved the overloaded function 7329/// to the function declaration Fn, so patch up the expression E to 7330/// refer (possibly indirectly) to Fn. Returns the new expr. 7331Expr *Sema::FixOverloadedFunctionReference(Expr *E, DeclAccessPair Found, 7332 FunctionDecl *Fn) { 7333 if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) { 7334 Expr *SubExpr = FixOverloadedFunctionReference(PE->getSubExpr(), 7335 Found, Fn); 7336 if (SubExpr == PE->getSubExpr()) 7337 return PE->Retain(); 7338 7339 return new (Context) ParenExpr(PE->getLParen(), PE->getRParen(), SubExpr); 7340 } 7341 7342 if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) { 7343 Expr *SubExpr = FixOverloadedFunctionReference(ICE->getSubExpr(), 7344 Found, Fn); 7345 assert(Context.hasSameType(ICE->getSubExpr()->getType(), 7346 SubExpr->getType()) && 7347 "Implicit cast type cannot be determined from overload"); 7348 if (SubExpr == ICE->getSubExpr()) 7349 return ICE->Retain(); 7350 7351 return new (Context) ImplicitCastExpr(ICE->getType(), 7352 ICE->getCastKind(), 7353 SubExpr, CXXBaseSpecifierArray(), 7354 ICE->isLvalueCast()); 7355 } 7356 7357 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(E)) { 7358 assert(UnOp->getOpcode() == UnaryOperator::AddrOf && 7359 "Can only take the address of an overloaded function"); 7360 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 7361 if (Method->isStatic()) { 7362 // Do nothing: static member functions aren't any different 7363 // from non-member functions. 7364 } else { 7365 // Fix the sub expression, which really has to be an 7366 // UnresolvedLookupExpr holding an overloaded member function 7367 // or template. 7368 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(), 7369 Found, Fn); 7370 if (SubExpr == UnOp->getSubExpr()) 7371 return UnOp->Retain(); 7372 7373 assert(isa<DeclRefExpr>(SubExpr) 7374 && "fixed to something other than a decl ref"); 7375 assert(cast<DeclRefExpr>(SubExpr)->getQualifier() 7376 && "fixed to a member ref with no nested name qualifier"); 7377 7378 // We have taken the address of a pointer to member 7379 // function. Perform the computation here so that we get the 7380 // appropriate pointer to member type. 7381 QualType ClassType 7382 = Context.getTypeDeclType(cast<RecordDecl>(Method->getDeclContext())); 7383 QualType MemPtrType 7384 = Context.getMemberPointerType(Fn->getType(), ClassType.getTypePtr()); 7385 7386 return new (Context) UnaryOperator(SubExpr, UnaryOperator::AddrOf, 7387 MemPtrType, UnOp->getOperatorLoc()); 7388 } 7389 } 7390 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(), 7391 Found, Fn); 7392 if (SubExpr == UnOp->getSubExpr()) 7393 return UnOp->Retain(); 7394 7395 return new (Context) UnaryOperator(SubExpr, UnaryOperator::AddrOf, 7396 Context.getPointerType(SubExpr->getType()), 7397 UnOp->getOperatorLoc()); 7398 } 7399 7400 if (UnresolvedLookupExpr *ULE = dyn_cast<UnresolvedLookupExpr>(E)) { 7401 // FIXME: avoid copy. 7402 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 7403 if (ULE->hasExplicitTemplateArgs()) { 7404 ULE->copyTemplateArgumentsInto(TemplateArgsBuffer); 7405 TemplateArgs = &TemplateArgsBuffer; 7406 } 7407 7408 return DeclRefExpr::Create(Context, 7409 ULE->getQualifier(), 7410 ULE->getQualifierRange(), 7411 Fn, 7412 ULE->getNameLoc(), 7413 Fn->getType(), 7414 TemplateArgs); 7415 } 7416 7417 if (UnresolvedMemberExpr *MemExpr = dyn_cast<UnresolvedMemberExpr>(E)) { 7418 // FIXME: avoid copy. 7419 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 7420 if (MemExpr->hasExplicitTemplateArgs()) { 7421 MemExpr->copyTemplateArgumentsInto(TemplateArgsBuffer); 7422 TemplateArgs = &TemplateArgsBuffer; 7423 } 7424 7425 Expr *Base; 7426 7427 // If we're filling in 7428 if (MemExpr->isImplicitAccess()) { 7429 if (cast<CXXMethodDecl>(Fn)->isStatic()) { 7430 return DeclRefExpr::Create(Context, 7431 MemExpr->getQualifier(), 7432 MemExpr->getQualifierRange(), 7433 Fn, 7434 MemExpr->getMemberLoc(), 7435 Fn->getType(), 7436 TemplateArgs); 7437 } else { 7438 SourceLocation Loc = MemExpr->getMemberLoc(); 7439 if (MemExpr->getQualifier()) 7440 Loc = MemExpr->getQualifierRange().getBegin(); 7441 Base = new (Context) CXXThisExpr(Loc, 7442 MemExpr->getBaseType(), 7443 /*isImplicit=*/true); 7444 } 7445 } else 7446 Base = MemExpr->getBase()->Retain(); 7447 7448 return MemberExpr::Create(Context, Base, 7449 MemExpr->isArrow(), 7450 MemExpr->getQualifier(), 7451 MemExpr->getQualifierRange(), 7452 Fn, 7453 Found, 7454 MemExpr->getMemberLoc(), 7455 TemplateArgs, 7456 Fn->getType()); 7457 } 7458 7459 assert(false && "Invalid reference to overloaded function"); 7460 return E->Retain(); 7461} 7462 7463Sema::OwningExprResult Sema::FixOverloadedFunctionReference(OwningExprResult E, 7464 DeclAccessPair Found, 7465 FunctionDecl *Fn) { 7466 return Owned(FixOverloadedFunctionReference((Expr *)E.get(), Found, Fn)); 7467} 7468 7469} // end namespace clang 7470