SemaOverload.cpp revision 208600
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() || getFromType()->isBlockPointerType() || 159 First == ICK_Array_To_Pointer || First == ICK_Function_To_Pointer)) 160 return true; 161 162 return false; 163} 164 165/// isPointerConversionToVoidPointer - Determines whether this 166/// conversion is a conversion of a pointer to a void pointer. This is 167/// used as part of the ranking of standard conversion sequences (C++ 168/// 13.3.3.2p4). 169bool 170StandardConversionSequence:: 171isPointerConversionToVoidPointer(ASTContext& Context) const { 172 QualType FromType = getFromType(); 173 QualType ToType = getToType(1); 174 175 // Note that FromType has not necessarily been transformed by the 176 // array-to-pointer implicit conversion, so check for its presence 177 // and redo the conversion to get a pointer. 178 if (First == ICK_Array_To_Pointer) 179 FromType = Context.getArrayDecayedType(FromType); 180 181 if (Second == ICK_Pointer_Conversion && FromType->isPointerType()) 182 if (const PointerType* ToPtrType = ToType->getAs<PointerType>()) 183 return ToPtrType->getPointeeType()->isVoidType(); 184 185 return false; 186} 187 188/// DebugPrint - Print this standard conversion sequence to standard 189/// error. Useful for debugging overloading issues. 190void StandardConversionSequence::DebugPrint() const { 191 llvm::raw_ostream &OS = llvm::errs(); 192 bool PrintedSomething = false; 193 if (First != ICK_Identity) { 194 OS << GetImplicitConversionName(First); 195 PrintedSomething = true; 196 } 197 198 if (Second != ICK_Identity) { 199 if (PrintedSomething) { 200 OS << " -> "; 201 } 202 OS << GetImplicitConversionName(Second); 203 204 if (CopyConstructor) { 205 OS << " (by copy constructor)"; 206 } else if (DirectBinding) { 207 OS << " (direct reference binding)"; 208 } else if (ReferenceBinding) { 209 OS << " (reference binding)"; 210 } 211 PrintedSomething = true; 212 } 213 214 if (Third != ICK_Identity) { 215 if (PrintedSomething) { 216 OS << " -> "; 217 } 218 OS << GetImplicitConversionName(Third); 219 PrintedSomething = true; 220 } 221 222 if (!PrintedSomething) { 223 OS << "No conversions required"; 224 } 225} 226 227/// DebugPrint - Print this user-defined conversion sequence to standard 228/// error. Useful for debugging overloading issues. 229void UserDefinedConversionSequence::DebugPrint() const { 230 llvm::raw_ostream &OS = llvm::errs(); 231 if (Before.First || Before.Second || Before.Third) { 232 Before.DebugPrint(); 233 OS << " -> "; 234 } 235 OS << '\'' << ConversionFunction << '\''; 236 if (After.First || After.Second || After.Third) { 237 OS << " -> "; 238 After.DebugPrint(); 239 } 240} 241 242/// DebugPrint - Print this implicit conversion sequence to standard 243/// error. Useful for debugging overloading issues. 244void ImplicitConversionSequence::DebugPrint() const { 245 llvm::raw_ostream &OS = llvm::errs(); 246 switch (ConversionKind) { 247 case StandardConversion: 248 OS << "Standard conversion: "; 249 Standard.DebugPrint(); 250 break; 251 case UserDefinedConversion: 252 OS << "User-defined conversion: "; 253 UserDefined.DebugPrint(); 254 break; 255 case EllipsisConversion: 256 OS << "Ellipsis conversion"; 257 break; 258 case AmbiguousConversion: 259 OS << "Ambiguous conversion"; 260 break; 261 case BadConversion: 262 OS << "Bad conversion"; 263 break; 264 } 265 266 OS << "\n"; 267} 268 269void AmbiguousConversionSequence::construct() { 270 new (&conversions()) ConversionSet(); 271} 272 273void AmbiguousConversionSequence::destruct() { 274 conversions().~ConversionSet(); 275} 276 277void 278AmbiguousConversionSequence::copyFrom(const AmbiguousConversionSequence &O) { 279 FromTypePtr = O.FromTypePtr; 280 ToTypePtr = O.ToTypePtr; 281 new (&conversions()) ConversionSet(O.conversions()); 282} 283 284namespace { 285 // Structure used by OverloadCandidate::DeductionFailureInfo to store 286 // template parameter and template argument information. 287 struct DFIParamWithArguments { 288 TemplateParameter Param; 289 TemplateArgument FirstArg; 290 TemplateArgument SecondArg; 291 }; 292} 293 294/// \brief Convert from Sema's representation of template deduction information 295/// to the form used in overload-candidate information. 296OverloadCandidate::DeductionFailureInfo 297static MakeDeductionFailureInfo(ASTContext &Context, 298 Sema::TemplateDeductionResult TDK, 299 Sema::TemplateDeductionInfo &Info) { 300 OverloadCandidate::DeductionFailureInfo Result; 301 Result.Result = static_cast<unsigned>(TDK); 302 Result.Data = 0; 303 switch (TDK) { 304 case Sema::TDK_Success: 305 case Sema::TDK_InstantiationDepth: 306 case Sema::TDK_TooManyArguments: 307 case Sema::TDK_TooFewArguments: 308 break; 309 310 case Sema::TDK_Incomplete: 311 case Sema::TDK_InvalidExplicitArguments: 312 Result.Data = Info.Param.getOpaqueValue(); 313 break; 314 315 case Sema::TDK_Inconsistent: 316 case Sema::TDK_InconsistentQuals: { 317 // FIXME: Should allocate from normal heap so that we can free this later. 318 DFIParamWithArguments *Saved = new (Context) DFIParamWithArguments; 319 Saved->Param = Info.Param; 320 Saved->FirstArg = Info.FirstArg; 321 Saved->SecondArg = Info.SecondArg; 322 Result.Data = Saved; 323 break; 324 } 325 326 case Sema::TDK_SubstitutionFailure: 327 Result.Data = Info.take(); 328 break; 329 330 case Sema::TDK_NonDeducedMismatch: 331 case Sema::TDK_FailedOverloadResolution: 332 break; 333 } 334 335 return Result; 336} 337 338void OverloadCandidate::DeductionFailureInfo::Destroy() { 339 switch (static_cast<Sema::TemplateDeductionResult>(Result)) { 340 case Sema::TDK_Success: 341 case Sema::TDK_InstantiationDepth: 342 case Sema::TDK_Incomplete: 343 case Sema::TDK_TooManyArguments: 344 case Sema::TDK_TooFewArguments: 345 case Sema::TDK_InvalidExplicitArguments: 346 break; 347 348 case Sema::TDK_Inconsistent: 349 case Sema::TDK_InconsistentQuals: 350 // FIXME: Destroy the data? 351 Data = 0; 352 break; 353 354 case Sema::TDK_SubstitutionFailure: 355 // FIXME: Destroy the template arugment list? 356 Data = 0; 357 break; 358 359 // Unhandled 360 case Sema::TDK_NonDeducedMismatch: 361 case Sema::TDK_FailedOverloadResolution: 362 break; 363 } 364} 365 366TemplateParameter 367OverloadCandidate::DeductionFailureInfo::getTemplateParameter() { 368 switch (static_cast<Sema::TemplateDeductionResult>(Result)) { 369 case Sema::TDK_Success: 370 case Sema::TDK_InstantiationDepth: 371 case Sema::TDK_TooManyArguments: 372 case Sema::TDK_TooFewArguments: 373 case Sema::TDK_SubstitutionFailure: 374 return TemplateParameter(); 375 376 case Sema::TDK_Incomplete: 377 case Sema::TDK_InvalidExplicitArguments: 378 return TemplateParameter::getFromOpaqueValue(Data); 379 380 case Sema::TDK_Inconsistent: 381 case Sema::TDK_InconsistentQuals: 382 return static_cast<DFIParamWithArguments*>(Data)->Param; 383 384 // Unhandled 385 case Sema::TDK_NonDeducedMismatch: 386 case Sema::TDK_FailedOverloadResolution: 387 break; 388 } 389 390 return TemplateParameter(); 391} 392 393TemplateArgumentList * 394OverloadCandidate::DeductionFailureInfo::getTemplateArgumentList() { 395 switch (static_cast<Sema::TemplateDeductionResult>(Result)) { 396 case Sema::TDK_Success: 397 case Sema::TDK_InstantiationDepth: 398 case Sema::TDK_TooManyArguments: 399 case Sema::TDK_TooFewArguments: 400 case Sema::TDK_Incomplete: 401 case Sema::TDK_InvalidExplicitArguments: 402 case Sema::TDK_Inconsistent: 403 case Sema::TDK_InconsistentQuals: 404 return 0; 405 406 case Sema::TDK_SubstitutionFailure: 407 return static_cast<TemplateArgumentList*>(Data); 408 409 // Unhandled 410 case Sema::TDK_NonDeducedMismatch: 411 case Sema::TDK_FailedOverloadResolution: 412 break; 413 } 414 415 return 0; 416} 417 418const TemplateArgument *OverloadCandidate::DeductionFailureInfo::getFirstArg() { 419 switch (static_cast<Sema::TemplateDeductionResult>(Result)) { 420 case Sema::TDK_Success: 421 case Sema::TDK_InstantiationDepth: 422 case Sema::TDK_Incomplete: 423 case Sema::TDK_TooManyArguments: 424 case Sema::TDK_TooFewArguments: 425 case Sema::TDK_InvalidExplicitArguments: 426 case Sema::TDK_SubstitutionFailure: 427 return 0; 428 429 case Sema::TDK_Inconsistent: 430 case Sema::TDK_InconsistentQuals: 431 return &static_cast<DFIParamWithArguments*>(Data)->FirstArg; 432 433 // Unhandled 434 case Sema::TDK_NonDeducedMismatch: 435 case Sema::TDK_FailedOverloadResolution: 436 break; 437 } 438 439 return 0; 440} 441 442const TemplateArgument * 443OverloadCandidate::DeductionFailureInfo::getSecondArg() { 444 switch (static_cast<Sema::TemplateDeductionResult>(Result)) { 445 case Sema::TDK_Success: 446 case Sema::TDK_InstantiationDepth: 447 case Sema::TDK_Incomplete: 448 case Sema::TDK_TooManyArguments: 449 case Sema::TDK_TooFewArguments: 450 case Sema::TDK_InvalidExplicitArguments: 451 case Sema::TDK_SubstitutionFailure: 452 return 0; 453 454 case Sema::TDK_Inconsistent: 455 case Sema::TDK_InconsistentQuals: 456 return &static_cast<DFIParamWithArguments*>(Data)->SecondArg; 457 458 // Unhandled 459 case Sema::TDK_NonDeducedMismatch: 460 case Sema::TDK_FailedOverloadResolution: 461 break; 462 } 463 464 return 0; 465} 466 467void OverloadCandidateSet::clear() { 468 inherited::clear(); 469 Functions.clear(); 470} 471 472// IsOverload - Determine whether the given New declaration is an 473// overload of the declarations in Old. This routine returns false if 474// New and Old cannot be overloaded, e.g., if New has the same 475// signature as some function in Old (C++ 1.3.10) or if the Old 476// declarations aren't functions (or function templates) at all. When 477// it does return false, MatchedDecl will point to the decl that New 478// cannot be overloaded with. This decl may be a UsingShadowDecl on 479// top of the underlying declaration. 480// 481// Example: Given the following input: 482// 483// void f(int, float); // #1 484// void f(int, int); // #2 485// int f(int, int); // #3 486// 487// When we process #1, there is no previous declaration of "f", 488// so IsOverload will not be used. 489// 490// When we process #2, Old contains only the FunctionDecl for #1. By 491// comparing the parameter types, we see that #1 and #2 are overloaded 492// (since they have different signatures), so this routine returns 493// false; MatchedDecl is unchanged. 494// 495// When we process #3, Old is an overload set containing #1 and #2. We 496// compare the signatures of #3 to #1 (they're overloaded, so we do 497// nothing) and then #3 to #2. Since the signatures of #3 and #2 are 498// identical (return types of functions are not part of the 499// signature), IsOverload returns false and MatchedDecl will be set to 500// point to the FunctionDecl for #2. 501Sema::OverloadKind 502Sema::CheckOverload(FunctionDecl *New, const LookupResult &Old, 503 NamedDecl *&Match) { 504 for (LookupResult::iterator I = Old.begin(), E = Old.end(); 505 I != E; ++I) { 506 NamedDecl *OldD = (*I)->getUnderlyingDecl(); 507 if (FunctionTemplateDecl *OldT = dyn_cast<FunctionTemplateDecl>(OldD)) { 508 if (!IsOverload(New, OldT->getTemplatedDecl())) { 509 Match = *I; 510 return Ovl_Match; 511 } 512 } else if (FunctionDecl *OldF = dyn_cast<FunctionDecl>(OldD)) { 513 if (!IsOverload(New, OldF)) { 514 Match = *I; 515 return Ovl_Match; 516 } 517 } else if (isa<UsingDecl>(OldD) || isa<TagDecl>(OldD)) { 518 // We can overload with these, which can show up when doing 519 // redeclaration checks for UsingDecls. 520 assert(Old.getLookupKind() == LookupUsingDeclName); 521 } else if (isa<UnresolvedUsingValueDecl>(OldD)) { 522 // Optimistically assume that an unresolved using decl will 523 // overload; if it doesn't, we'll have to diagnose during 524 // template instantiation. 525 } else { 526 // (C++ 13p1): 527 // Only function declarations can be overloaded; object and type 528 // declarations cannot be overloaded. 529 Match = *I; 530 return Ovl_NonFunction; 531 } 532 } 533 534 return Ovl_Overload; 535} 536 537bool Sema::IsOverload(FunctionDecl *New, FunctionDecl *Old) { 538 FunctionTemplateDecl *OldTemplate = Old->getDescribedFunctionTemplate(); 539 FunctionTemplateDecl *NewTemplate = New->getDescribedFunctionTemplate(); 540 541 // C++ [temp.fct]p2: 542 // A function template can be overloaded with other function templates 543 // and with normal (non-template) functions. 544 if ((OldTemplate == 0) != (NewTemplate == 0)) 545 return true; 546 547 // Is the function New an overload of the function Old? 548 QualType OldQType = Context.getCanonicalType(Old->getType()); 549 QualType NewQType = Context.getCanonicalType(New->getType()); 550 551 // Compare the signatures (C++ 1.3.10) of the two functions to 552 // determine whether they are overloads. If we find any mismatch 553 // in the signature, they are overloads. 554 555 // If either of these functions is a K&R-style function (no 556 // prototype), then we consider them to have matching signatures. 557 if (isa<FunctionNoProtoType>(OldQType.getTypePtr()) || 558 isa<FunctionNoProtoType>(NewQType.getTypePtr())) 559 return false; 560 561 FunctionProtoType* OldType = cast<FunctionProtoType>(OldQType); 562 FunctionProtoType* NewType = cast<FunctionProtoType>(NewQType); 563 564 // The signature of a function includes the types of its 565 // parameters (C++ 1.3.10), which includes the presence or absence 566 // of the ellipsis; see C++ DR 357). 567 if (OldQType != NewQType && 568 (OldType->getNumArgs() != NewType->getNumArgs() || 569 OldType->isVariadic() != NewType->isVariadic() || 570 !FunctionArgTypesAreEqual(OldType, NewType))) 571 return true; 572 573 // C++ [temp.over.link]p4: 574 // The signature of a function template consists of its function 575 // signature, its return type and its template parameter list. The names 576 // of the template parameters are significant only for establishing the 577 // relationship between the template parameters and the rest of the 578 // signature. 579 // 580 // We check the return type and template parameter lists for function 581 // templates first; the remaining checks follow. 582 if (NewTemplate && 583 (!TemplateParameterListsAreEqual(NewTemplate->getTemplateParameters(), 584 OldTemplate->getTemplateParameters(), 585 false, TPL_TemplateMatch) || 586 OldType->getResultType() != NewType->getResultType())) 587 return true; 588 589 // If the function is a class member, its signature includes the 590 // cv-qualifiers (if any) on the function itself. 591 // 592 // As part of this, also check whether one of the member functions 593 // is static, in which case they are not overloads (C++ 594 // 13.1p2). While not part of the definition of the signature, 595 // this check is important to determine whether these functions 596 // can be overloaded. 597 CXXMethodDecl* OldMethod = dyn_cast<CXXMethodDecl>(Old); 598 CXXMethodDecl* NewMethod = dyn_cast<CXXMethodDecl>(New); 599 if (OldMethod && NewMethod && 600 !OldMethod->isStatic() && !NewMethod->isStatic() && 601 OldMethod->getTypeQualifiers() != NewMethod->getTypeQualifiers()) 602 return true; 603 604 // The signatures match; this is not an overload. 605 return false; 606} 607 608/// TryImplicitConversion - Attempt to perform an implicit conversion 609/// from the given expression (Expr) to the given type (ToType). This 610/// function returns an implicit conversion sequence that can be used 611/// to perform the initialization. Given 612/// 613/// void f(float f); 614/// void g(int i) { f(i); } 615/// 616/// this routine would produce an implicit conversion sequence to 617/// describe the initialization of f from i, which will be a standard 618/// conversion sequence containing an lvalue-to-rvalue conversion (C++ 619/// 4.1) followed by a floating-integral conversion (C++ 4.9). 620// 621/// Note that this routine only determines how the conversion can be 622/// performed; it does not actually perform the conversion. As such, 623/// it will not produce any diagnostics if no conversion is available, 624/// but will instead return an implicit conversion sequence of kind 625/// "BadConversion". 626/// 627/// If @p SuppressUserConversions, then user-defined conversions are 628/// not permitted. 629/// If @p AllowExplicit, then explicit user-defined conversions are 630/// permitted. 631ImplicitConversionSequence 632Sema::TryImplicitConversion(Expr* From, QualType ToType, 633 bool SuppressUserConversions, 634 bool AllowExplicit, 635 bool InOverloadResolution) { 636 ImplicitConversionSequence ICS; 637 if (IsStandardConversion(From, ToType, InOverloadResolution, ICS.Standard)) { 638 ICS.setStandard(); 639 return ICS; 640 } 641 642 if (!getLangOptions().CPlusPlus) { 643 ICS.setBad(BadConversionSequence::no_conversion, From, ToType); 644 return ICS; 645 } 646 647 if (SuppressUserConversions) { 648 // C++ [over.ics.user]p4: 649 // A conversion of an expression of class type to the same class 650 // type is given Exact Match rank, and a conversion of an 651 // expression of class type to a base class of that type is 652 // given Conversion rank, in spite of the fact that a copy/move 653 // constructor (i.e., a user-defined conversion function) is 654 // called for those cases. 655 QualType FromType = From->getType(); 656 if (!ToType->getAs<RecordType>() || !FromType->getAs<RecordType>() || 657 !(Context.hasSameUnqualifiedType(FromType, ToType) || 658 IsDerivedFrom(FromType, ToType))) { 659 // We're not in the case above, so there is no conversion that 660 // we can perform. 661 ICS.setBad(BadConversionSequence::no_conversion, From, ToType); 662 return ICS; 663 } 664 665 ICS.setStandard(); 666 ICS.Standard.setAsIdentityConversion(); 667 ICS.Standard.setFromType(FromType); 668 ICS.Standard.setAllToTypes(ToType); 669 670 // We don't actually check at this point whether there is a valid 671 // copy/move constructor, since overloading just assumes that it 672 // exists. When we actually perform initialization, we'll find the 673 // appropriate constructor to copy the returned object, if needed. 674 ICS.Standard.CopyConstructor = 0; 675 676 // Determine whether this is considered a derived-to-base conversion. 677 if (!Context.hasSameUnqualifiedType(FromType, ToType)) 678 ICS.Standard.Second = ICK_Derived_To_Base; 679 680 return ICS; 681 } 682 683 // Attempt user-defined conversion. 684 OverloadCandidateSet Conversions(From->getExprLoc()); 685 OverloadingResult UserDefResult 686 = IsUserDefinedConversion(From, ToType, ICS.UserDefined, Conversions, 687 AllowExplicit); 688 689 if (UserDefResult == OR_Success) { 690 ICS.setUserDefined(); 691 // C++ [over.ics.user]p4: 692 // A conversion of an expression of class type to the same class 693 // type is given Exact Match rank, and a conversion of an 694 // expression of class type to a base class of that type is 695 // given Conversion rank, in spite of the fact that a copy 696 // constructor (i.e., a user-defined conversion function) is 697 // called for those cases. 698 if (CXXConstructorDecl *Constructor 699 = dyn_cast<CXXConstructorDecl>(ICS.UserDefined.ConversionFunction)) { 700 QualType FromCanon 701 = Context.getCanonicalType(From->getType().getUnqualifiedType()); 702 QualType ToCanon = Context.getCanonicalType(ToType).getUnqualifiedType(); 703 if (Constructor->isCopyConstructor() && 704 (FromCanon == ToCanon || IsDerivedFrom(FromCanon, ToCanon))) { 705 // Turn this into a "standard" conversion sequence, so that it 706 // gets ranked with standard conversion sequences. 707 ICS.setStandard(); 708 ICS.Standard.setAsIdentityConversion(); 709 ICS.Standard.setFromType(From->getType()); 710 ICS.Standard.setAllToTypes(ToType); 711 ICS.Standard.CopyConstructor = Constructor; 712 if (ToCanon != FromCanon) 713 ICS.Standard.Second = ICK_Derived_To_Base; 714 } 715 } 716 717 // C++ [over.best.ics]p4: 718 // However, when considering the argument of a user-defined 719 // conversion function that is a candidate by 13.3.1.3 when 720 // invoked for the copying of the temporary in the second step 721 // of a class copy-initialization, or by 13.3.1.4, 13.3.1.5, or 722 // 13.3.1.6 in all cases, only standard conversion sequences and 723 // ellipsis conversion sequences are allowed. 724 if (SuppressUserConversions && ICS.isUserDefined()) { 725 ICS.setBad(BadConversionSequence::suppressed_user, From, ToType); 726 } 727 } else if (UserDefResult == OR_Ambiguous && !SuppressUserConversions) { 728 ICS.setAmbiguous(); 729 ICS.Ambiguous.setFromType(From->getType()); 730 ICS.Ambiguous.setToType(ToType); 731 for (OverloadCandidateSet::iterator Cand = Conversions.begin(); 732 Cand != Conversions.end(); ++Cand) 733 if (Cand->Viable) 734 ICS.Ambiguous.addConversion(Cand->Function); 735 } else { 736 ICS.setBad(BadConversionSequence::no_conversion, From, ToType); 737 } 738 739 return ICS; 740} 741 742/// PerformImplicitConversion - Perform an implicit conversion of the 743/// expression From to the type ToType. Returns true if there was an 744/// error, false otherwise. The expression From is replaced with the 745/// converted expression. Flavor is the kind of conversion we're 746/// performing, used in the error message. If @p AllowExplicit, 747/// explicit user-defined conversions are permitted. 748bool 749Sema::PerformImplicitConversion(Expr *&From, QualType ToType, 750 AssignmentAction Action, bool AllowExplicit) { 751 ImplicitConversionSequence ICS; 752 return PerformImplicitConversion(From, ToType, Action, AllowExplicit, ICS); 753} 754 755bool 756Sema::PerformImplicitConversion(Expr *&From, QualType ToType, 757 AssignmentAction Action, bool AllowExplicit, 758 ImplicitConversionSequence& ICS) { 759 ICS = TryImplicitConversion(From, ToType, 760 /*SuppressUserConversions=*/false, 761 AllowExplicit, 762 /*InOverloadResolution=*/false); 763 return PerformImplicitConversion(From, ToType, ICS, Action); 764} 765 766/// \brief Determine whether the conversion from FromType to ToType is a valid 767/// conversion that strips "noreturn" off the nested function type. 768static bool IsNoReturnConversion(ASTContext &Context, QualType FromType, 769 QualType ToType, QualType &ResultTy) { 770 if (Context.hasSameUnqualifiedType(FromType, ToType)) 771 return false; 772 773 // Strip the noreturn off the type we're converting from; noreturn can 774 // safely be removed. 775 FromType = Context.getNoReturnType(FromType, false); 776 if (!Context.hasSameUnqualifiedType(FromType, ToType)) 777 return false; 778 779 ResultTy = FromType; 780 return true; 781} 782 783/// \brief Determine whether the conversion from FromType to ToType is a valid 784/// vector conversion. 785/// 786/// \param ICK Will be set to the vector conversion kind, if this is a vector 787/// conversion. 788static bool IsVectorConversion(ASTContext &Context, QualType FromType, 789 QualType ToType, ImplicitConversionKind &ICK) { 790 // We need at least one of these types to be a vector type to have a vector 791 // conversion. 792 if (!ToType->isVectorType() && !FromType->isVectorType()) 793 return false; 794 795 // Identical types require no conversions. 796 if (Context.hasSameUnqualifiedType(FromType, ToType)) 797 return false; 798 799 // There are no conversions between extended vector types, only identity. 800 if (ToType->isExtVectorType()) { 801 // There are no conversions between extended vector types other than the 802 // identity conversion. 803 if (FromType->isExtVectorType()) 804 return false; 805 806 // Vector splat from any arithmetic type to a vector. 807 if (!FromType->isVectorType() && FromType->isArithmeticType()) { 808 ICK = ICK_Vector_Splat; 809 return true; 810 } 811 } 812 813 // If lax vector conversions are permitted and the vector types are of the 814 // same size, we can perform the conversion. 815 if (Context.getLangOptions().LaxVectorConversions && 816 FromType->isVectorType() && ToType->isVectorType() && 817 Context.getTypeSize(FromType) == Context.getTypeSize(ToType)) { 818 ICK = ICK_Vector_Conversion; 819 return true; 820 } 821 822 return false; 823} 824 825/// IsStandardConversion - Determines whether there is a standard 826/// conversion sequence (C++ [conv], C++ [over.ics.scs]) from the 827/// expression From to the type ToType. Standard conversion sequences 828/// only consider non-class types; for conversions that involve class 829/// types, use TryImplicitConversion. If a conversion exists, SCS will 830/// contain the standard conversion sequence required to perform this 831/// conversion and this routine will return true. Otherwise, this 832/// routine will return false and the value of SCS is unspecified. 833bool 834Sema::IsStandardConversion(Expr* From, QualType ToType, 835 bool InOverloadResolution, 836 StandardConversionSequence &SCS) { 837 QualType FromType = From->getType(); 838 839 // Standard conversions (C++ [conv]) 840 SCS.setAsIdentityConversion(); 841 SCS.DeprecatedStringLiteralToCharPtr = false; 842 SCS.IncompatibleObjC = false; 843 SCS.setFromType(FromType); 844 SCS.CopyConstructor = 0; 845 846 // There are no standard conversions for class types in C++, so 847 // abort early. When overloading in C, however, we do permit 848 if (FromType->isRecordType() || ToType->isRecordType()) { 849 if (getLangOptions().CPlusPlus) 850 return false; 851 852 // When we're overloading in C, we allow, as standard conversions, 853 } 854 855 // The first conversion can be an lvalue-to-rvalue conversion, 856 // array-to-pointer conversion, or function-to-pointer conversion 857 // (C++ 4p1). 858 859 if (FromType == Context.OverloadTy) { 860 DeclAccessPair AccessPair; 861 if (FunctionDecl *Fn 862 = ResolveAddressOfOverloadedFunction(From, ToType, false, 863 AccessPair)) { 864 // We were able to resolve the address of the overloaded function, 865 // so we can convert to the type of that function. 866 FromType = Fn->getType(); 867 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 868 if (!Method->isStatic()) { 869 Type *ClassType 870 = Context.getTypeDeclType(Method->getParent()).getTypePtr(); 871 FromType = Context.getMemberPointerType(FromType, ClassType); 872 } 873 } 874 875 // If the "from" expression takes the address of the overloaded 876 // function, update the type of the resulting expression accordingly. 877 if (FromType->getAs<FunctionType>()) 878 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(From->IgnoreParens())) 879 if (UnOp->getOpcode() == UnaryOperator::AddrOf) 880 FromType = Context.getPointerType(FromType); 881 882 // Check that we've computed the proper type after overload resolution. 883 assert(Context.hasSameType(FromType, 884 FixOverloadedFunctionReference(From, AccessPair, Fn)->getType())); 885 } else { 886 return false; 887 } 888 } 889 // Lvalue-to-rvalue conversion (C++ 4.1): 890 // An lvalue (3.10) of a non-function, non-array type T can be 891 // converted to an rvalue. 892 Expr::isLvalueResult argIsLvalue = From->isLvalue(Context); 893 if (argIsLvalue == Expr::LV_Valid && 894 !FromType->isFunctionType() && !FromType->isArrayType() && 895 Context.getCanonicalType(FromType) != Context.OverloadTy) { 896 SCS.First = ICK_Lvalue_To_Rvalue; 897 898 // If T is a non-class type, the type of the rvalue is the 899 // cv-unqualified version of T. Otherwise, the type of the rvalue 900 // is T (C++ 4.1p1). C++ can't get here with class types; in C, we 901 // just strip the qualifiers because they don't matter. 902 FromType = FromType.getUnqualifiedType(); 903 } else if (FromType->isArrayType()) { 904 // Array-to-pointer conversion (C++ 4.2) 905 SCS.First = ICK_Array_To_Pointer; 906 907 // An lvalue or rvalue of type "array of N T" or "array of unknown 908 // bound of T" can be converted to an rvalue of type "pointer to 909 // T" (C++ 4.2p1). 910 FromType = Context.getArrayDecayedType(FromType); 911 912 if (IsStringLiteralToNonConstPointerConversion(From, ToType)) { 913 // This conversion is deprecated. (C++ D.4). 914 SCS.DeprecatedStringLiteralToCharPtr = true; 915 916 // For the purpose of ranking in overload resolution 917 // (13.3.3.1.1), this conversion is considered an 918 // array-to-pointer conversion followed by a qualification 919 // conversion (4.4). (C++ 4.2p2) 920 SCS.Second = ICK_Identity; 921 SCS.Third = ICK_Qualification; 922 SCS.setAllToTypes(FromType); 923 return true; 924 } 925 } else if (FromType->isFunctionType() && argIsLvalue == Expr::LV_Valid) { 926 // Function-to-pointer conversion (C++ 4.3). 927 SCS.First = ICK_Function_To_Pointer; 928 929 // An lvalue of function type T can be converted to an rvalue of 930 // type "pointer to T." The result is a pointer to the 931 // function. (C++ 4.3p1). 932 FromType = Context.getPointerType(FromType); 933 } else { 934 // We don't require any conversions for the first step. 935 SCS.First = ICK_Identity; 936 } 937 SCS.setToType(0, FromType); 938 939 // The second conversion can be an integral promotion, floating 940 // point promotion, integral conversion, floating point conversion, 941 // floating-integral conversion, pointer conversion, 942 // pointer-to-member conversion, or boolean conversion (C++ 4p1). 943 // For overloading in C, this can also be a "compatible-type" 944 // conversion. 945 bool IncompatibleObjC = false; 946 ImplicitConversionKind SecondICK = ICK_Identity; 947 if (Context.hasSameUnqualifiedType(FromType, ToType)) { 948 // The unqualified versions of the types are the same: there's no 949 // conversion to do. 950 SCS.Second = ICK_Identity; 951 } else if (IsIntegralPromotion(From, FromType, ToType)) { 952 // Integral promotion (C++ 4.5). 953 SCS.Second = ICK_Integral_Promotion; 954 FromType = ToType.getUnqualifiedType(); 955 } else if (IsFloatingPointPromotion(FromType, ToType)) { 956 // Floating point promotion (C++ 4.6). 957 SCS.Second = ICK_Floating_Promotion; 958 FromType = ToType.getUnqualifiedType(); 959 } else if (IsComplexPromotion(FromType, ToType)) { 960 // Complex promotion (Clang extension) 961 SCS.Second = ICK_Complex_Promotion; 962 FromType = ToType.getUnqualifiedType(); 963 } else if ((FromType->isIntegralType() || FromType->isEnumeralType()) && 964 (ToType->isIntegralType() && !ToType->isEnumeralType())) { 965 // Integral conversions (C++ 4.7). 966 SCS.Second = ICK_Integral_Conversion; 967 FromType = ToType.getUnqualifiedType(); 968 } else if (FromType->isComplexType() && ToType->isComplexType()) { 969 // Complex conversions (C99 6.3.1.6) 970 SCS.Second = ICK_Complex_Conversion; 971 FromType = ToType.getUnqualifiedType(); 972 } else if ((FromType->isComplexType() && ToType->isArithmeticType()) || 973 (ToType->isComplexType() && FromType->isArithmeticType())) { 974 // Complex-real conversions (C99 6.3.1.7) 975 SCS.Second = ICK_Complex_Real; 976 FromType = ToType.getUnqualifiedType(); 977 } else if (FromType->isFloatingType() && ToType->isFloatingType()) { 978 // Floating point conversions (C++ 4.8). 979 SCS.Second = ICK_Floating_Conversion; 980 FromType = ToType.getUnqualifiedType(); 981 } else if ((FromType->isFloatingType() && 982 ToType->isIntegralType() && (!ToType->isBooleanType() && 983 !ToType->isEnumeralType())) || 984 ((FromType->isIntegralType() || FromType->isEnumeralType()) && 985 ToType->isFloatingType())) { 986 // Floating-integral conversions (C++ 4.9). 987 SCS.Second = ICK_Floating_Integral; 988 FromType = ToType.getUnqualifiedType(); 989 } else if (IsPointerConversion(From, FromType, ToType, InOverloadResolution, 990 FromType, IncompatibleObjC)) { 991 // Pointer conversions (C++ 4.10). 992 SCS.Second = ICK_Pointer_Conversion; 993 SCS.IncompatibleObjC = IncompatibleObjC; 994 } else if (IsMemberPointerConversion(From, FromType, ToType, 995 InOverloadResolution, FromType)) { 996 // Pointer to member conversions (4.11). 997 SCS.Second = ICK_Pointer_Member; 998 } else if (ToType->isBooleanType() && 999 (FromType->isArithmeticType() || 1000 FromType->isEnumeralType() || 1001 FromType->isAnyPointerType() || 1002 FromType->isBlockPointerType() || 1003 FromType->isMemberPointerType() || 1004 FromType->isNullPtrType())) { 1005 // Boolean conversions (C++ 4.12). 1006 SCS.Second = ICK_Boolean_Conversion; 1007 FromType = Context.BoolTy; 1008 } else if (IsVectorConversion(Context, FromType, ToType, SecondICK)) { 1009 SCS.Second = SecondICK; 1010 FromType = ToType.getUnqualifiedType(); 1011 } else if (!getLangOptions().CPlusPlus && 1012 Context.typesAreCompatible(ToType, FromType)) { 1013 // Compatible conversions (Clang extension for C function overloading) 1014 SCS.Second = ICK_Compatible_Conversion; 1015 FromType = ToType.getUnqualifiedType(); 1016 } else if (IsNoReturnConversion(Context, FromType, ToType, FromType)) { 1017 // Treat a conversion that strips "noreturn" as an identity conversion. 1018 SCS.Second = ICK_NoReturn_Adjustment; 1019 } else { 1020 // No second conversion required. 1021 SCS.Second = ICK_Identity; 1022 } 1023 SCS.setToType(1, FromType); 1024 1025 QualType CanonFrom; 1026 QualType CanonTo; 1027 // The third conversion can be a qualification conversion (C++ 4p1). 1028 if (IsQualificationConversion(FromType, ToType)) { 1029 SCS.Third = ICK_Qualification; 1030 FromType = ToType; 1031 CanonFrom = Context.getCanonicalType(FromType); 1032 CanonTo = Context.getCanonicalType(ToType); 1033 } else { 1034 // No conversion required 1035 SCS.Third = ICK_Identity; 1036 1037 // C++ [over.best.ics]p6: 1038 // [...] Any difference in top-level cv-qualification is 1039 // subsumed by the initialization itself and does not constitute 1040 // a conversion. [...] 1041 CanonFrom = Context.getCanonicalType(FromType); 1042 CanonTo = Context.getCanonicalType(ToType); 1043 if (CanonFrom.getLocalUnqualifiedType() 1044 == CanonTo.getLocalUnqualifiedType() && 1045 (CanonFrom.getLocalCVRQualifiers() != CanonTo.getLocalCVRQualifiers() 1046 || CanonFrom.getObjCGCAttr() != CanonTo.getObjCGCAttr())) { 1047 FromType = ToType; 1048 CanonFrom = CanonTo; 1049 } 1050 } 1051 SCS.setToType(2, FromType); 1052 1053 // If we have not converted the argument type to the parameter type, 1054 // this is a bad conversion sequence. 1055 if (CanonFrom != CanonTo) 1056 return false; 1057 1058 return true; 1059} 1060 1061/// IsIntegralPromotion - Determines whether the conversion from the 1062/// expression From (whose potentially-adjusted type is FromType) to 1063/// ToType is an integral promotion (C++ 4.5). If so, returns true and 1064/// sets PromotedType to the promoted type. 1065bool Sema::IsIntegralPromotion(Expr *From, QualType FromType, QualType ToType) { 1066 const BuiltinType *To = ToType->getAs<BuiltinType>(); 1067 // All integers are built-in. 1068 if (!To) { 1069 return false; 1070 } 1071 1072 // An rvalue of type char, signed char, unsigned char, short int, or 1073 // unsigned short int can be converted to an rvalue of type int if 1074 // int can represent all the values of the source type; otherwise, 1075 // the source rvalue can be converted to an rvalue of type unsigned 1076 // int (C++ 4.5p1). 1077 if (FromType->isPromotableIntegerType() && !FromType->isBooleanType() && 1078 !FromType->isEnumeralType()) { 1079 if (// We can promote any signed, promotable integer type to an int 1080 (FromType->isSignedIntegerType() || 1081 // We can promote any unsigned integer type whose size is 1082 // less than int to an int. 1083 (!FromType->isSignedIntegerType() && 1084 Context.getTypeSize(FromType) < Context.getTypeSize(ToType)))) { 1085 return To->getKind() == BuiltinType::Int; 1086 } 1087 1088 return To->getKind() == BuiltinType::UInt; 1089 } 1090 1091 // An rvalue of type wchar_t (3.9.1) or an enumeration type (7.2) 1092 // can be converted to an rvalue of the first of the following types 1093 // that can represent all the values of its underlying type: int, 1094 // unsigned int, long, or unsigned long (C++ 4.5p2). 1095 1096 // We pre-calculate the promotion type for enum types. 1097 if (const EnumType *FromEnumType = FromType->getAs<EnumType>()) 1098 if (ToType->isIntegerType()) 1099 return Context.hasSameUnqualifiedType(ToType, 1100 FromEnumType->getDecl()->getPromotionType()); 1101 1102 if (FromType->isWideCharType() && ToType->isIntegerType()) { 1103 // Determine whether the type we're converting from is signed or 1104 // unsigned. 1105 bool FromIsSigned; 1106 uint64_t FromSize = Context.getTypeSize(FromType); 1107 1108 // FIXME: Is wchar_t signed or unsigned? We assume it's signed for now. 1109 FromIsSigned = true; 1110 1111 // The types we'll try to promote to, in the appropriate 1112 // order. Try each of these types. 1113 QualType PromoteTypes[6] = { 1114 Context.IntTy, Context.UnsignedIntTy, 1115 Context.LongTy, Context.UnsignedLongTy , 1116 Context.LongLongTy, Context.UnsignedLongLongTy 1117 }; 1118 for (int Idx = 0; Idx < 6; ++Idx) { 1119 uint64_t ToSize = Context.getTypeSize(PromoteTypes[Idx]); 1120 if (FromSize < ToSize || 1121 (FromSize == ToSize && 1122 FromIsSigned == PromoteTypes[Idx]->isSignedIntegerType())) { 1123 // We found the type that we can promote to. If this is the 1124 // type we wanted, we have a promotion. Otherwise, no 1125 // promotion. 1126 return Context.hasSameUnqualifiedType(ToType, PromoteTypes[Idx]); 1127 } 1128 } 1129 } 1130 1131 // An rvalue for an integral bit-field (9.6) can be converted to an 1132 // rvalue of type int if int can represent all the values of the 1133 // bit-field; otherwise, it can be converted to unsigned int if 1134 // unsigned int can represent all the values of the bit-field. If 1135 // the bit-field is larger yet, no integral promotion applies to 1136 // it. If the bit-field has an enumerated type, it is treated as any 1137 // other value of that type for promotion purposes (C++ 4.5p3). 1138 // FIXME: We should delay checking of bit-fields until we actually perform the 1139 // conversion. 1140 using llvm::APSInt; 1141 if (From) 1142 if (FieldDecl *MemberDecl = From->getBitField()) { 1143 APSInt BitWidth; 1144 if (FromType->isIntegralType() && !FromType->isEnumeralType() && 1145 MemberDecl->getBitWidth()->isIntegerConstantExpr(BitWidth, Context)) { 1146 APSInt ToSize(BitWidth.getBitWidth(), BitWidth.isUnsigned()); 1147 ToSize = Context.getTypeSize(ToType); 1148 1149 // Are we promoting to an int from a bitfield that fits in an int? 1150 if (BitWidth < ToSize || 1151 (FromType->isSignedIntegerType() && BitWidth <= ToSize)) { 1152 return To->getKind() == BuiltinType::Int; 1153 } 1154 1155 // Are we promoting to an unsigned int from an unsigned bitfield 1156 // that fits into an unsigned int? 1157 if (FromType->isUnsignedIntegerType() && BitWidth <= ToSize) { 1158 return To->getKind() == BuiltinType::UInt; 1159 } 1160 1161 return false; 1162 } 1163 } 1164 1165 // An rvalue of type bool can be converted to an rvalue of type int, 1166 // with false becoming zero and true becoming one (C++ 4.5p4). 1167 if (FromType->isBooleanType() && To->getKind() == BuiltinType::Int) { 1168 return true; 1169 } 1170 1171 return false; 1172} 1173 1174/// IsFloatingPointPromotion - Determines whether the conversion from 1175/// FromType to ToType is a floating point promotion (C++ 4.6). If so, 1176/// returns true and sets PromotedType to the promoted type. 1177bool Sema::IsFloatingPointPromotion(QualType FromType, QualType ToType) { 1178 /// An rvalue of type float can be converted to an rvalue of type 1179 /// double. (C++ 4.6p1). 1180 if (const BuiltinType *FromBuiltin = FromType->getAs<BuiltinType>()) 1181 if (const BuiltinType *ToBuiltin = ToType->getAs<BuiltinType>()) { 1182 if (FromBuiltin->getKind() == BuiltinType::Float && 1183 ToBuiltin->getKind() == BuiltinType::Double) 1184 return true; 1185 1186 // C99 6.3.1.5p1: 1187 // When a float is promoted to double or long double, or a 1188 // double is promoted to long double [...]. 1189 if (!getLangOptions().CPlusPlus && 1190 (FromBuiltin->getKind() == BuiltinType::Float || 1191 FromBuiltin->getKind() == BuiltinType::Double) && 1192 (ToBuiltin->getKind() == BuiltinType::LongDouble)) 1193 return true; 1194 } 1195 1196 return false; 1197} 1198 1199/// \brief Determine if a conversion is a complex promotion. 1200/// 1201/// A complex promotion is defined as a complex -> complex conversion 1202/// where the conversion between the underlying real types is a 1203/// floating-point or integral promotion. 1204bool Sema::IsComplexPromotion(QualType FromType, QualType ToType) { 1205 const ComplexType *FromComplex = FromType->getAs<ComplexType>(); 1206 if (!FromComplex) 1207 return false; 1208 1209 const ComplexType *ToComplex = ToType->getAs<ComplexType>(); 1210 if (!ToComplex) 1211 return false; 1212 1213 return IsFloatingPointPromotion(FromComplex->getElementType(), 1214 ToComplex->getElementType()) || 1215 IsIntegralPromotion(0, FromComplex->getElementType(), 1216 ToComplex->getElementType()); 1217} 1218 1219/// BuildSimilarlyQualifiedPointerType - In a pointer conversion from 1220/// the pointer type FromPtr to a pointer to type ToPointee, with the 1221/// same type qualifiers as FromPtr has on its pointee type. ToType, 1222/// if non-empty, will be a pointer to ToType that may or may not have 1223/// the right set of qualifiers on its pointee. 1224static QualType 1225BuildSimilarlyQualifiedPointerType(const PointerType *FromPtr, 1226 QualType ToPointee, QualType ToType, 1227 ASTContext &Context) { 1228 QualType CanonFromPointee = Context.getCanonicalType(FromPtr->getPointeeType()); 1229 QualType CanonToPointee = Context.getCanonicalType(ToPointee); 1230 Qualifiers Quals = CanonFromPointee.getQualifiers(); 1231 1232 // Exact qualifier match -> return the pointer type we're converting to. 1233 if (CanonToPointee.getLocalQualifiers() == Quals) { 1234 // ToType is exactly what we need. Return it. 1235 if (!ToType.isNull()) 1236 return ToType.getUnqualifiedType(); 1237 1238 // Build a pointer to ToPointee. It has the right qualifiers 1239 // already. 1240 return Context.getPointerType(ToPointee); 1241 } 1242 1243 // Just build a canonical type that has the right qualifiers. 1244 return Context.getPointerType( 1245 Context.getQualifiedType(CanonToPointee.getLocalUnqualifiedType(), 1246 Quals)); 1247} 1248 1249/// BuildSimilarlyQualifiedObjCObjectPointerType - In a pointer conversion from 1250/// the FromType, which is an objective-c pointer, to ToType, which may or may 1251/// not have the right set of qualifiers. 1252static QualType 1253BuildSimilarlyQualifiedObjCObjectPointerType(QualType FromType, 1254 QualType ToType, 1255 ASTContext &Context) { 1256 QualType CanonFromType = Context.getCanonicalType(FromType); 1257 QualType CanonToType = Context.getCanonicalType(ToType); 1258 Qualifiers Quals = CanonFromType.getQualifiers(); 1259 1260 // Exact qualifier match -> return the pointer type we're converting to. 1261 if (CanonToType.getLocalQualifiers() == Quals) 1262 return ToType; 1263 1264 // Just build a canonical type that has the right qualifiers. 1265 return Context.getQualifiedType(CanonToType.getLocalUnqualifiedType(), Quals); 1266} 1267 1268static bool isNullPointerConstantForConversion(Expr *Expr, 1269 bool InOverloadResolution, 1270 ASTContext &Context) { 1271 // Handle value-dependent integral null pointer constants correctly. 1272 // http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#903 1273 if (Expr->isValueDependent() && !Expr->isTypeDependent() && 1274 Expr->getType()->isIntegralType()) 1275 return !InOverloadResolution; 1276 1277 return Expr->isNullPointerConstant(Context, 1278 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull 1279 : Expr::NPC_ValueDependentIsNull); 1280} 1281 1282/// IsPointerConversion - Determines whether the conversion of the 1283/// expression From, which has the (possibly adjusted) type FromType, 1284/// can be converted to the type ToType via a pointer conversion (C++ 1285/// 4.10). If so, returns true and places the converted type (that 1286/// might differ from ToType in its cv-qualifiers at some level) into 1287/// ConvertedType. 1288/// 1289/// This routine also supports conversions to and from block pointers 1290/// and conversions with Objective-C's 'id', 'id<protocols...>', and 1291/// pointers to interfaces. FIXME: Once we've determined the 1292/// appropriate overloading rules for Objective-C, we may want to 1293/// split the Objective-C checks into a different routine; however, 1294/// GCC seems to consider all of these conversions to be pointer 1295/// conversions, so for now they live here. IncompatibleObjC will be 1296/// set if the conversion is an allowed Objective-C conversion that 1297/// should result in a warning. 1298bool Sema::IsPointerConversion(Expr *From, QualType FromType, QualType ToType, 1299 bool InOverloadResolution, 1300 QualType& ConvertedType, 1301 bool &IncompatibleObjC) { 1302 IncompatibleObjC = false; 1303 if (isObjCPointerConversion(FromType, ToType, ConvertedType, IncompatibleObjC)) 1304 return true; 1305 1306 // Conversion from a null pointer constant to any Objective-C pointer type. 1307 if (ToType->isObjCObjectPointerType() && 1308 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1309 ConvertedType = ToType; 1310 return true; 1311 } 1312 1313 // Blocks: Block pointers can be converted to void*. 1314 if (FromType->isBlockPointerType() && ToType->isPointerType() && 1315 ToType->getAs<PointerType>()->getPointeeType()->isVoidType()) { 1316 ConvertedType = ToType; 1317 return true; 1318 } 1319 // Blocks: A null pointer constant can be converted to a block 1320 // pointer type. 1321 if (ToType->isBlockPointerType() && 1322 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1323 ConvertedType = ToType; 1324 return true; 1325 } 1326 1327 // If the left-hand-side is nullptr_t, the right side can be a null 1328 // pointer constant. 1329 if (ToType->isNullPtrType() && 1330 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1331 ConvertedType = ToType; 1332 return true; 1333 } 1334 1335 const PointerType* ToTypePtr = ToType->getAs<PointerType>(); 1336 if (!ToTypePtr) 1337 return false; 1338 1339 // A null pointer constant can be converted to a pointer type (C++ 4.10p1). 1340 if (isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1341 ConvertedType = ToType; 1342 return true; 1343 } 1344 1345 // Beyond this point, both types need to be pointers 1346 // , including objective-c pointers. 1347 QualType ToPointeeType = ToTypePtr->getPointeeType(); 1348 if (FromType->isObjCObjectPointerType() && ToPointeeType->isVoidType()) { 1349 ConvertedType = BuildSimilarlyQualifiedObjCObjectPointerType(FromType, 1350 ToType, Context); 1351 return true; 1352 1353 } 1354 const PointerType *FromTypePtr = FromType->getAs<PointerType>(); 1355 if (!FromTypePtr) 1356 return false; 1357 1358 QualType FromPointeeType = FromTypePtr->getPointeeType(); 1359 1360 // An rvalue of type "pointer to cv T," where T is an object type, 1361 // can be converted to an rvalue of type "pointer to cv void" (C++ 1362 // 4.10p2). 1363 if (FromPointeeType->isObjectType() && ToPointeeType->isVoidType()) { 1364 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1365 ToPointeeType, 1366 ToType, Context); 1367 return true; 1368 } 1369 1370 // When we're overloading in C, we allow a special kind of pointer 1371 // conversion for compatible-but-not-identical pointee types. 1372 if (!getLangOptions().CPlusPlus && 1373 Context.typesAreCompatible(FromPointeeType, ToPointeeType)) { 1374 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1375 ToPointeeType, 1376 ToType, Context); 1377 return true; 1378 } 1379 1380 // C++ [conv.ptr]p3: 1381 // 1382 // An rvalue of type "pointer to cv D," where D is a class type, 1383 // can be converted to an rvalue of type "pointer to cv B," where 1384 // B is a base class (clause 10) of D. If B is an inaccessible 1385 // (clause 11) or ambiguous (10.2) base class of D, a program that 1386 // necessitates this conversion is ill-formed. The result of the 1387 // conversion is a pointer to the base class sub-object of the 1388 // derived class object. The null pointer value is converted to 1389 // the null pointer value of the destination type. 1390 // 1391 // Note that we do not check for ambiguity or inaccessibility 1392 // here. That is handled by CheckPointerConversion. 1393 if (getLangOptions().CPlusPlus && 1394 FromPointeeType->isRecordType() && ToPointeeType->isRecordType() && 1395 !Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType) && 1396 !RequireCompleteType(From->getLocStart(), FromPointeeType, PDiag()) && 1397 IsDerivedFrom(FromPointeeType, ToPointeeType)) { 1398 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1399 ToPointeeType, 1400 ToType, Context); 1401 return true; 1402 } 1403 1404 return false; 1405} 1406 1407/// isObjCPointerConversion - Determines whether this is an 1408/// Objective-C pointer conversion. Subroutine of IsPointerConversion, 1409/// with the same arguments and return values. 1410bool Sema::isObjCPointerConversion(QualType FromType, QualType ToType, 1411 QualType& ConvertedType, 1412 bool &IncompatibleObjC) { 1413 if (!getLangOptions().ObjC1) 1414 return false; 1415 1416 // First, we handle all conversions on ObjC object pointer types. 1417 const ObjCObjectPointerType* ToObjCPtr = ToType->getAs<ObjCObjectPointerType>(); 1418 const ObjCObjectPointerType *FromObjCPtr = 1419 FromType->getAs<ObjCObjectPointerType>(); 1420 1421 if (ToObjCPtr && FromObjCPtr) { 1422 // Objective C++: We're able to convert between "id" or "Class" and a 1423 // pointer to any interface (in both directions). 1424 if (ToObjCPtr->isObjCBuiltinType() && FromObjCPtr->isObjCBuiltinType()) { 1425 ConvertedType = ToType; 1426 return true; 1427 } 1428 // Conversions with Objective-C's id<...>. 1429 if ((FromObjCPtr->isObjCQualifiedIdType() || 1430 ToObjCPtr->isObjCQualifiedIdType()) && 1431 Context.ObjCQualifiedIdTypesAreCompatible(ToType, FromType, 1432 /*compare=*/false)) { 1433 ConvertedType = ToType; 1434 return true; 1435 } 1436 // Objective C++: We're able to convert from a pointer to an 1437 // interface to a pointer to a different interface. 1438 if (Context.canAssignObjCInterfaces(ToObjCPtr, FromObjCPtr)) { 1439 const ObjCInterfaceType* LHS = ToObjCPtr->getInterfaceType(); 1440 const ObjCInterfaceType* RHS = FromObjCPtr->getInterfaceType(); 1441 if (getLangOptions().CPlusPlus && LHS && RHS && 1442 !ToObjCPtr->getPointeeType().isAtLeastAsQualifiedAs( 1443 FromObjCPtr->getPointeeType())) 1444 return false; 1445 ConvertedType = ToType; 1446 return true; 1447 } 1448 1449 if (Context.canAssignObjCInterfaces(FromObjCPtr, ToObjCPtr)) { 1450 // Okay: this is some kind of implicit downcast of Objective-C 1451 // interfaces, which is permitted. However, we're going to 1452 // complain about it. 1453 IncompatibleObjC = true; 1454 ConvertedType = FromType; 1455 return true; 1456 } 1457 } 1458 // Beyond this point, both types need to be C pointers or block pointers. 1459 QualType ToPointeeType; 1460 if (const PointerType *ToCPtr = ToType->getAs<PointerType>()) 1461 ToPointeeType = ToCPtr->getPointeeType(); 1462 else if (const BlockPointerType *ToBlockPtr = 1463 ToType->getAs<BlockPointerType>()) { 1464 // Objective C++: We're able to convert from a pointer to any object 1465 // to a block pointer type. 1466 if (FromObjCPtr && FromObjCPtr->isObjCBuiltinType()) { 1467 ConvertedType = ToType; 1468 return true; 1469 } 1470 ToPointeeType = ToBlockPtr->getPointeeType(); 1471 } 1472 else if (FromType->getAs<BlockPointerType>() && 1473 ToObjCPtr && ToObjCPtr->isObjCBuiltinType()) { 1474 // Objective C++: We're able to convert from a block pointer type to a 1475 // pointer to any object. 1476 ConvertedType = ToType; 1477 return true; 1478 } 1479 else 1480 return false; 1481 1482 QualType FromPointeeType; 1483 if (const PointerType *FromCPtr = FromType->getAs<PointerType>()) 1484 FromPointeeType = FromCPtr->getPointeeType(); 1485 else if (const BlockPointerType *FromBlockPtr = FromType->getAs<BlockPointerType>()) 1486 FromPointeeType = FromBlockPtr->getPointeeType(); 1487 else 1488 return false; 1489 1490 // If we have pointers to pointers, recursively check whether this 1491 // is an Objective-C conversion. 1492 if (FromPointeeType->isPointerType() && ToPointeeType->isPointerType() && 1493 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, 1494 IncompatibleObjC)) { 1495 // We always complain about this conversion. 1496 IncompatibleObjC = true; 1497 ConvertedType = ToType; 1498 return true; 1499 } 1500 // Allow conversion of pointee being objective-c pointer to another one; 1501 // as in I* to id. 1502 if (FromPointeeType->getAs<ObjCObjectPointerType>() && 1503 ToPointeeType->getAs<ObjCObjectPointerType>() && 1504 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, 1505 IncompatibleObjC)) { 1506 ConvertedType = ToType; 1507 return true; 1508 } 1509 1510 // If we have pointers to functions or blocks, check whether the only 1511 // differences in the argument and result types are in Objective-C 1512 // pointer conversions. If so, we permit the conversion (but 1513 // complain about it). 1514 const FunctionProtoType *FromFunctionType 1515 = FromPointeeType->getAs<FunctionProtoType>(); 1516 const FunctionProtoType *ToFunctionType 1517 = ToPointeeType->getAs<FunctionProtoType>(); 1518 if (FromFunctionType && ToFunctionType) { 1519 // If the function types are exactly the same, this isn't an 1520 // Objective-C pointer conversion. 1521 if (Context.getCanonicalType(FromPointeeType) 1522 == Context.getCanonicalType(ToPointeeType)) 1523 return false; 1524 1525 // Perform the quick checks that will tell us whether these 1526 // function types are obviously different. 1527 if (FromFunctionType->getNumArgs() != ToFunctionType->getNumArgs() || 1528 FromFunctionType->isVariadic() != ToFunctionType->isVariadic() || 1529 FromFunctionType->getTypeQuals() != ToFunctionType->getTypeQuals()) 1530 return false; 1531 1532 bool HasObjCConversion = false; 1533 if (Context.getCanonicalType(FromFunctionType->getResultType()) 1534 == Context.getCanonicalType(ToFunctionType->getResultType())) { 1535 // Okay, the types match exactly. Nothing to do. 1536 } else if (isObjCPointerConversion(FromFunctionType->getResultType(), 1537 ToFunctionType->getResultType(), 1538 ConvertedType, IncompatibleObjC)) { 1539 // Okay, we have an Objective-C pointer conversion. 1540 HasObjCConversion = true; 1541 } else { 1542 // Function types are too different. Abort. 1543 return false; 1544 } 1545 1546 // Check argument types. 1547 for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumArgs(); 1548 ArgIdx != NumArgs; ++ArgIdx) { 1549 QualType FromArgType = FromFunctionType->getArgType(ArgIdx); 1550 QualType ToArgType = ToFunctionType->getArgType(ArgIdx); 1551 if (Context.getCanonicalType(FromArgType) 1552 == Context.getCanonicalType(ToArgType)) { 1553 // Okay, the types match exactly. Nothing to do. 1554 } else if (isObjCPointerConversion(FromArgType, ToArgType, 1555 ConvertedType, IncompatibleObjC)) { 1556 // Okay, we have an Objective-C pointer conversion. 1557 HasObjCConversion = true; 1558 } else { 1559 // Argument types are too different. Abort. 1560 return false; 1561 } 1562 } 1563 1564 if (HasObjCConversion) { 1565 // We had an Objective-C conversion. Allow this pointer 1566 // conversion, but complain about it. 1567 ConvertedType = ToType; 1568 IncompatibleObjC = true; 1569 return true; 1570 } 1571 } 1572 1573 return false; 1574} 1575 1576/// FunctionArgTypesAreEqual - This routine checks two function proto types 1577/// for equlity of their argument types. Caller has already checked that 1578/// they have same number of arguments. This routine assumes that Objective-C 1579/// pointer types which only differ in their protocol qualifiers are equal. 1580bool Sema::FunctionArgTypesAreEqual(FunctionProtoType* OldType, 1581 FunctionProtoType* NewType){ 1582 if (!getLangOptions().ObjC1) 1583 return std::equal(OldType->arg_type_begin(), OldType->arg_type_end(), 1584 NewType->arg_type_begin()); 1585 1586 for (FunctionProtoType::arg_type_iterator O = OldType->arg_type_begin(), 1587 N = NewType->arg_type_begin(), 1588 E = OldType->arg_type_end(); O && (O != E); ++O, ++N) { 1589 QualType ToType = (*O); 1590 QualType FromType = (*N); 1591 if (ToType != FromType) { 1592 if (const PointerType *PTTo = ToType->getAs<PointerType>()) { 1593 if (const PointerType *PTFr = FromType->getAs<PointerType>()) 1594 if ((PTTo->getPointeeType()->isObjCQualifiedIdType() && 1595 PTFr->getPointeeType()->isObjCQualifiedIdType()) || 1596 (PTTo->getPointeeType()->isObjCQualifiedClassType() && 1597 PTFr->getPointeeType()->isObjCQualifiedClassType())) 1598 continue; 1599 } 1600 else if (const ObjCObjectPointerType *PTTo = 1601 ToType->getAs<ObjCObjectPointerType>()) { 1602 if (const ObjCObjectPointerType *PTFr = 1603 FromType->getAs<ObjCObjectPointerType>()) 1604 if (PTTo->getInterfaceDecl() == PTFr->getInterfaceDecl()) 1605 continue; 1606 } 1607 return false; 1608 } 1609 } 1610 return true; 1611} 1612 1613/// CheckPointerConversion - Check the pointer conversion from the 1614/// expression From to the type ToType. This routine checks for 1615/// ambiguous or inaccessible derived-to-base pointer 1616/// conversions for which IsPointerConversion has already returned 1617/// true. It returns true and produces a diagnostic if there was an 1618/// error, or returns false otherwise. 1619bool Sema::CheckPointerConversion(Expr *From, QualType ToType, 1620 CastExpr::CastKind &Kind, 1621 CXXBaseSpecifierArray& BasePath, 1622 bool IgnoreBaseAccess) { 1623 QualType FromType = From->getType(); 1624 1625 if (const PointerType *FromPtrType = FromType->getAs<PointerType>()) 1626 if (const PointerType *ToPtrType = ToType->getAs<PointerType>()) { 1627 QualType FromPointeeType = FromPtrType->getPointeeType(), 1628 ToPointeeType = ToPtrType->getPointeeType(); 1629 1630 if (FromPointeeType->isRecordType() && ToPointeeType->isRecordType() && 1631 !Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType)) { 1632 // We must have a derived-to-base conversion. Check an 1633 // ambiguous or inaccessible conversion. 1634 if (CheckDerivedToBaseConversion(FromPointeeType, ToPointeeType, 1635 From->getExprLoc(), 1636 From->getSourceRange(), &BasePath, 1637 IgnoreBaseAccess)) 1638 return true; 1639 1640 // The conversion was successful. 1641 Kind = CastExpr::CK_DerivedToBase; 1642 } 1643 } 1644 if (const ObjCObjectPointerType *FromPtrType = 1645 FromType->getAs<ObjCObjectPointerType>()) 1646 if (const ObjCObjectPointerType *ToPtrType = 1647 ToType->getAs<ObjCObjectPointerType>()) { 1648 // Objective-C++ conversions are always okay. 1649 // FIXME: We should have a different class of conversions for the 1650 // Objective-C++ implicit conversions. 1651 if (FromPtrType->isObjCBuiltinType() || ToPtrType->isObjCBuiltinType()) 1652 return false; 1653 1654 } 1655 return false; 1656} 1657 1658/// IsMemberPointerConversion - Determines whether the conversion of the 1659/// expression From, which has the (possibly adjusted) type FromType, can be 1660/// converted to the type ToType via a member pointer conversion (C++ 4.11). 1661/// If so, returns true and places the converted type (that might differ from 1662/// ToType in its cv-qualifiers at some level) into ConvertedType. 1663bool Sema::IsMemberPointerConversion(Expr *From, QualType FromType, 1664 QualType ToType, 1665 bool InOverloadResolution, 1666 QualType &ConvertedType) { 1667 const MemberPointerType *ToTypePtr = ToType->getAs<MemberPointerType>(); 1668 if (!ToTypePtr) 1669 return false; 1670 1671 // A null pointer constant can be converted to a member pointer (C++ 4.11p1) 1672 if (From->isNullPointerConstant(Context, 1673 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull 1674 : Expr::NPC_ValueDependentIsNull)) { 1675 ConvertedType = ToType; 1676 return true; 1677 } 1678 1679 // Otherwise, both types have to be member pointers. 1680 const MemberPointerType *FromTypePtr = FromType->getAs<MemberPointerType>(); 1681 if (!FromTypePtr) 1682 return false; 1683 1684 // A pointer to member of B can be converted to a pointer to member of D, 1685 // where D is derived from B (C++ 4.11p2). 1686 QualType FromClass(FromTypePtr->getClass(), 0); 1687 QualType ToClass(ToTypePtr->getClass(), 0); 1688 // FIXME: What happens when these are dependent? Is this function even called? 1689 1690 if (IsDerivedFrom(ToClass, FromClass)) { 1691 ConvertedType = Context.getMemberPointerType(FromTypePtr->getPointeeType(), 1692 ToClass.getTypePtr()); 1693 return true; 1694 } 1695 1696 return false; 1697} 1698 1699/// CheckMemberPointerConversion - Check the member pointer conversion from the 1700/// expression From to the type ToType. This routine checks for ambiguous or 1701/// virtual or inaccessible base-to-derived member pointer conversions 1702/// for which IsMemberPointerConversion has already returned true. It returns 1703/// true and produces a diagnostic if there was an error, or returns false 1704/// otherwise. 1705bool Sema::CheckMemberPointerConversion(Expr *From, QualType ToType, 1706 CastExpr::CastKind &Kind, 1707 CXXBaseSpecifierArray &BasePath, 1708 bool IgnoreBaseAccess) { 1709 QualType FromType = From->getType(); 1710 const MemberPointerType *FromPtrType = FromType->getAs<MemberPointerType>(); 1711 if (!FromPtrType) { 1712 // This must be a null pointer to member pointer conversion 1713 assert(From->isNullPointerConstant(Context, 1714 Expr::NPC_ValueDependentIsNull) && 1715 "Expr must be null pointer constant!"); 1716 Kind = CastExpr::CK_NullToMemberPointer; 1717 return false; 1718 } 1719 1720 const MemberPointerType *ToPtrType = ToType->getAs<MemberPointerType>(); 1721 assert(ToPtrType && "No member pointer cast has a target type " 1722 "that is not a member pointer."); 1723 1724 QualType FromClass = QualType(FromPtrType->getClass(), 0); 1725 QualType ToClass = QualType(ToPtrType->getClass(), 0); 1726 1727 // FIXME: What about dependent types? 1728 assert(FromClass->isRecordType() && "Pointer into non-class."); 1729 assert(ToClass->isRecordType() && "Pointer into non-class."); 1730 1731 CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true, 1732 /*DetectVirtual=*/true); 1733 bool DerivationOkay = IsDerivedFrom(ToClass, FromClass, Paths); 1734 assert(DerivationOkay && 1735 "Should not have been called if derivation isn't OK."); 1736 (void)DerivationOkay; 1737 1738 if (Paths.isAmbiguous(Context.getCanonicalType(FromClass). 1739 getUnqualifiedType())) { 1740 std::string PathDisplayStr = getAmbiguousPathsDisplayString(Paths); 1741 Diag(From->getExprLoc(), diag::err_ambiguous_memptr_conv) 1742 << 0 << FromClass << ToClass << PathDisplayStr << From->getSourceRange(); 1743 return true; 1744 } 1745 1746 if (const RecordType *VBase = Paths.getDetectedVirtual()) { 1747 Diag(From->getExprLoc(), diag::err_memptr_conv_via_virtual) 1748 << FromClass << ToClass << QualType(VBase, 0) 1749 << From->getSourceRange(); 1750 return true; 1751 } 1752 1753 if (!IgnoreBaseAccess) 1754 CheckBaseClassAccess(From->getExprLoc(), FromClass, ToClass, 1755 Paths.front(), 1756 diag::err_downcast_from_inaccessible_base); 1757 1758 // Must be a base to derived member conversion. 1759 BuildBasePathArray(Paths, BasePath); 1760 Kind = CastExpr::CK_BaseToDerivedMemberPointer; 1761 return false; 1762} 1763 1764/// IsQualificationConversion - Determines whether the conversion from 1765/// an rvalue of type FromType to ToType is a qualification conversion 1766/// (C++ 4.4). 1767bool 1768Sema::IsQualificationConversion(QualType FromType, QualType ToType) { 1769 FromType = Context.getCanonicalType(FromType); 1770 ToType = Context.getCanonicalType(ToType); 1771 1772 // If FromType and ToType are the same type, this is not a 1773 // qualification conversion. 1774 if (FromType.getUnqualifiedType() == ToType.getUnqualifiedType()) 1775 return false; 1776 1777 // (C++ 4.4p4): 1778 // A conversion can add cv-qualifiers at levels other than the first 1779 // in multi-level pointers, subject to the following rules: [...] 1780 bool PreviousToQualsIncludeConst = true; 1781 bool UnwrappedAnyPointer = false; 1782 while (UnwrapSimilarPointerTypes(FromType, ToType)) { 1783 // Within each iteration of the loop, we check the qualifiers to 1784 // determine if this still looks like a qualification 1785 // conversion. Then, if all is well, we unwrap one more level of 1786 // pointers or pointers-to-members and do it all again 1787 // until there are no more pointers or pointers-to-members left to 1788 // unwrap. 1789 UnwrappedAnyPointer = true; 1790 1791 // -- for every j > 0, if const is in cv 1,j then const is in cv 1792 // 2,j, and similarly for volatile. 1793 if (!ToType.isAtLeastAsQualifiedAs(FromType)) 1794 return false; 1795 1796 // -- if the cv 1,j and cv 2,j are different, then const is in 1797 // every cv for 0 < k < j. 1798 if (FromType.getCVRQualifiers() != ToType.getCVRQualifiers() 1799 && !PreviousToQualsIncludeConst) 1800 return false; 1801 1802 // Keep track of whether all prior cv-qualifiers in the "to" type 1803 // include const. 1804 PreviousToQualsIncludeConst 1805 = PreviousToQualsIncludeConst && ToType.isConstQualified(); 1806 } 1807 1808 // We are left with FromType and ToType being the pointee types 1809 // after unwrapping the original FromType and ToType the same number 1810 // of types. If we unwrapped any pointers, and if FromType and 1811 // ToType have the same unqualified type (since we checked 1812 // qualifiers above), then this is a qualification conversion. 1813 return UnwrappedAnyPointer && Context.hasSameUnqualifiedType(FromType,ToType); 1814} 1815 1816/// Determines whether there is a user-defined conversion sequence 1817/// (C++ [over.ics.user]) that converts expression From to the type 1818/// ToType. If such a conversion exists, User will contain the 1819/// user-defined conversion sequence that performs such a conversion 1820/// and this routine will return true. Otherwise, this routine returns 1821/// false and User is unspecified. 1822/// 1823/// \param AllowExplicit true if the conversion should consider C++0x 1824/// "explicit" conversion functions as well as non-explicit conversion 1825/// functions (C++0x [class.conv.fct]p2). 1826OverloadingResult Sema::IsUserDefinedConversion(Expr *From, QualType ToType, 1827 UserDefinedConversionSequence& User, 1828 OverloadCandidateSet& CandidateSet, 1829 bool AllowExplicit) { 1830 // Whether we will only visit constructors. 1831 bool ConstructorsOnly = false; 1832 1833 // If the type we are conversion to is a class type, enumerate its 1834 // constructors. 1835 if (const RecordType *ToRecordType = ToType->getAs<RecordType>()) { 1836 // C++ [over.match.ctor]p1: 1837 // When objects of class type are direct-initialized (8.5), or 1838 // copy-initialized from an expression of the same or a 1839 // derived class type (8.5), overload resolution selects the 1840 // constructor. [...] For copy-initialization, the candidate 1841 // functions are all the converting constructors (12.3.1) of 1842 // that class. The argument list is the expression-list within 1843 // the parentheses of the initializer. 1844 if (Context.hasSameUnqualifiedType(ToType, From->getType()) || 1845 (From->getType()->getAs<RecordType>() && 1846 IsDerivedFrom(From->getType(), ToType))) 1847 ConstructorsOnly = true; 1848 1849 if (RequireCompleteType(From->getLocStart(), ToType, PDiag())) { 1850 // We're not going to find any constructors. 1851 } else if (CXXRecordDecl *ToRecordDecl 1852 = dyn_cast<CXXRecordDecl>(ToRecordType->getDecl())) { 1853 DeclarationName ConstructorName 1854 = Context.DeclarationNames.getCXXConstructorName( 1855 Context.getCanonicalType(ToType).getUnqualifiedType()); 1856 DeclContext::lookup_iterator Con, ConEnd; 1857 for (llvm::tie(Con, ConEnd) 1858 = ToRecordDecl->lookup(ConstructorName); 1859 Con != ConEnd; ++Con) { 1860 NamedDecl *D = *Con; 1861 DeclAccessPair FoundDecl = DeclAccessPair::make(D, D->getAccess()); 1862 1863 // Find the constructor (which may be a template). 1864 CXXConstructorDecl *Constructor = 0; 1865 FunctionTemplateDecl *ConstructorTmpl 1866 = dyn_cast<FunctionTemplateDecl>(D); 1867 if (ConstructorTmpl) 1868 Constructor 1869 = cast<CXXConstructorDecl>(ConstructorTmpl->getTemplatedDecl()); 1870 else 1871 Constructor = cast<CXXConstructorDecl>(D); 1872 1873 if (!Constructor->isInvalidDecl() && 1874 Constructor->isConvertingConstructor(AllowExplicit)) { 1875 if (ConstructorTmpl) 1876 AddTemplateOverloadCandidate(ConstructorTmpl, FoundDecl, 1877 /*ExplicitArgs*/ 0, 1878 &From, 1, CandidateSet, 1879 /*SuppressUserConversions=*/!ConstructorsOnly); 1880 else 1881 // Allow one user-defined conversion when user specifies a 1882 // From->ToType conversion via an static cast (c-style, etc). 1883 AddOverloadCandidate(Constructor, FoundDecl, 1884 &From, 1, CandidateSet, 1885 /*SuppressUserConversions=*/!ConstructorsOnly); 1886 } 1887 } 1888 } 1889 } 1890 1891 // Enumerate conversion functions, if we're allowed to. 1892 if (ConstructorsOnly) { 1893 } else if (RequireCompleteType(From->getLocStart(), From->getType(), 1894 PDiag(0) << From->getSourceRange())) { 1895 // No conversion functions from incomplete types. 1896 } else if (const RecordType *FromRecordType 1897 = From->getType()->getAs<RecordType>()) { 1898 if (CXXRecordDecl *FromRecordDecl 1899 = dyn_cast<CXXRecordDecl>(FromRecordType->getDecl())) { 1900 // Add all of the conversion functions as candidates. 1901 const UnresolvedSetImpl *Conversions 1902 = FromRecordDecl->getVisibleConversionFunctions(); 1903 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 1904 E = Conversions->end(); I != E; ++I) { 1905 DeclAccessPair FoundDecl = I.getPair(); 1906 NamedDecl *D = FoundDecl.getDecl(); 1907 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext()); 1908 if (isa<UsingShadowDecl>(D)) 1909 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 1910 1911 CXXConversionDecl *Conv; 1912 FunctionTemplateDecl *ConvTemplate; 1913 if ((ConvTemplate = dyn_cast<FunctionTemplateDecl>(D))) 1914 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 1915 else 1916 Conv = cast<CXXConversionDecl>(D); 1917 1918 if (AllowExplicit || !Conv->isExplicit()) { 1919 if (ConvTemplate) 1920 AddTemplateConversionCandidate(ConvTemplate, FoundDecl, 1921 ActingContext, From, ToType, 1922 CandidateSet); 1923 else 1924 AddConversionCandidate(Conv, FoundDecl, ActingContext, 1925 From, ToType, CandidateSet); 1926 } 1927 } 1928 } 1929 } 1930 1931 OverloadCandidateSet::iterator Best; 1932 switch (BestViableFunction(CandidateSet, From->getLocStart(), Best)) { 1933 case OR_Success: 1934 // Record the standard conversion we used and the conversion function. 1935 if (CXXConstructorDecl *Constructor 1936 = dyn_cast<CXXConstructorDecl>(Best->Function)) { 1937 // C++ [over.ics.user]p1: 1938 // If the user-defined conversion is specified by a 1939 // constructor (12.3.1), the initial standard conversion 1940 // sequence converts the source type to the type required by 1941 // the argument of the constructor. 1942 // 1943 QualType ThisType = Constructor->getThisType(Context); 1944 if (Best->Conversions[0].isEllipsis()) 1945 User.EllipsisConversion = true; 1946 else { 1947 User.Before = Best->Conversions[0].Standard; 1948 User.EllipsisConversion = false; 1949 } 1950 User.ConversionFunction = Constructor; 1951 User.After.setAsIdentityConversion(); 1952 User.After.setFromType( 1953 ThisType->getAs<PointerType>()->getPointeeType()); 1954 User.After.setAllToTypes(ToType); 1955 return OR_Success; 1956 } else if (CXXConversionDecl *Conversion 1957 = dyn_cast<CXXConversionDecl>(Best->Function)) { 1958 // C++ [over.ics.user]p1: 1959 // 1960 // [...] If the user-defined conversion is specified by a 1961 // conversion function (12.3.2), the initial standard 1962 // conversion sequence converts the source type to the 1963 // implicit object parameter of the conversion function. 1964 User.Before = Best->Conversions[0].Standard; 1965 User.ConversionFunction = Conversion; 1966 User.EllipsisConversion = false; 1967 1968 // C++ [over.ics.user]p2: 1969 // The second standard conversion sequence converts the 1970 // result of the user-defined conversion to the target type 1971 // for the sequence. Since an implicit conversion sequence 1972 // is an initialization, the special rules for 1973 // initialization by user-defined conversion apply when 1974 // selecting the best user-defined conversion for a 1975 // user-defined conversion sequence (see 13.3.3 and 1976 // 13.3.3.1). 1977 User.After = Best->FinalConversion; 1978 return OR_Success; 1979 } else { 1980 assert(false && "Not a constructor or conversion function?"); 1981 return OR_No_Viable_Function; 1982 } 1983 1984 case OR_No_Viable_Function: 1985 return OR_No_Viable_Function; 1986 case OR_Deleted: 1987 // No conversion here! We're done. 1988 return OR_Deleted; 1989 1990 case OR_Ambiguous: 1991 return OR_Ambiguous; 1992 } 1993 1994 return OR_No_Viable_Function; 1995} 1996 1997bool 1998Sema::DiagnoseMultipleUserDefinedConversion(Expr *From, QualType ToType) { 1999 ImplicitConversionSequence ICS; 2000 OverloadCandidateSet CandidateSet(From->getExprLoc()); 2001 OverloadingResult OvResult = 2002 IsUserDefinedConversion(From, ToType, ICS.UserDefined, 2003 CandidateSet, false); 2004 if (OvResult == OR_Ambiguous) 2005 Diag(From->getSourceRange().getBegin(), 2006 diag::err_typecheck_ambiguous_condition) 2007 << From->getType() << ToType << From->getSourceRange(); 2008 else if (OvResult == OR_No_Viable_Function && !CandidateSet.empty()) 2009 Diag(From->getSourceRange().getBegin(), 2010 diag::err_typecheck_nonviable_condition) 2011 << From->getType() << ToType << From->getSourceRange(); 2012 else 2013 return false; 2014 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, &From, 1); 2015 return true; 2016} 2017 2018/// CompareImplicitConversionSequences - Compare two implicit 2019/// conversion sequences to determine whether one is better than the 2020/// other or if they are indistinguishable (C++ 13.3.3.2). 2021ImplicitConversionSequence::CompareKind 2022Sema::CompareImplicitConversionSequences(const ImplicitConversionSequence& ICS1, 2023 const ImplicitConversionSequence& ICS2) 2024{ 2025 // (C++ 13.3.3.2p2): When comparing the basic forms of implicit 2026 // conversion sequences (as defined in 13.3.3.1) 2027 // -- a standard conversion sequence (13.3.3.1.1) is a better 2028 // conversion sequence than a user-defined conversion sequence or 2029 // an ellipsis conversion sequence, and 2030 // -- a user-defined conversion sequence (13.3.3.1.2) is a better 2031 // conversion sequence than an ellipsis conversion sequence 2032 // (13.3.3.1.3). 2033 // 2034 // C++0x [over.best.ics]p10: 2035 // For the purpose of ranking implicit conversion sequences as 2036 // described in 13.3.3.2, the ambiguous conversion sequence is 2037 // treated as a user-defined sequence that is indistinguishable 2038 // from any other user-defined conversion sequence. 2039 if (ICS1.getKindRank() < ICS2.getKindRank()) 2040 return ImplicitConversionSequence::Better; 2041 else if (ICS2.getKindRank() < ICS1.getKindRank()) 2042 return ImplicitConversionSequence::Worse; 2043 2044 // The following checks require both conversion sequences to be of 2045 // the same kind. 2046 if (ICS1.getKind() != ICS2.getKind()) 2047 return ImplicitConversionSequence::Indistinguishable; 2048 2049 // Two implicit conversion sequences of the same form are 2050 // indistinguishable conversion sequences unless one of the 2051 // following rules apply: (C++ 13.3.3.2p3): 2052 if (ICS1.isStandard()) 2053 return CompareStandardConversionSequences(ICS1.Standard, ICS2.Standard); 2054 else if (ICS1.isUserDefined()) { 2055 // User-defined conversion sequence U1 is a better conversion 2056 // sequence than another user-defined conversion sequence U2 if 2057 // they contain the same user-defined conversion function or 2058 // constructor and if the second standard conversion sequence of 2059 // U1 is better than the second standard conversion sequence of 2060 // U2 (C++ 13.3.3.2p3). 2061 if (ICS1.UserDefined.ConversionFunction == 2062 ICS2.UserDefined.ConversionFunction) 2063 return CompareStandardConversionSequences(ICS1.UserDefined.After, 2064 ICS2.UserDefined.After); 2065 } 2066 2067 return ImplicitConversionSequence::Indistinguishable; 2068} 2069 2070// Per 13.3.3.2p3, compare the given standard conversion sequences to 2071// determine if one is a proper subset of the other. 2072static ImplicitConversionSequence::CompareKind 2073compareStandardConversionSubsets(ASTContext &Context, 2074 const StandardConversionSequence& SCS1, 2075 const StandardConversionSequence& SCS2) { 2076 ImplicitConversionSequence::CompareKind Result 2077 = ImplicitConversionSequence::Indistinguishable; 2078 2079 // the identity conversion sequence is considered to be a subsequence of 2080 // any non-identity conversion sequence 2081 if (SCS1.ReferenceBinding == SCS2.ReferenceBinding) { 2082 if (SCS1.isIdentityConversion() && !SCS2.isIdentityConversion()) 2083 return ImplicitConversionSequence::Better; 2084 else if (!SCS1.isIdentityConversion() && SCS2.isIdentityConversion()) 2085 return ImplicitConversionSequence::Worse; 2086 } 2087 2088 if (SCS1.Second != SCS2.Second) { 2089 if (SCS1.Second == ICK_Identity) 2090 Result = ImplicitConversionSequence::Better; 2091 else if (SCS2.Second == ICK_Identity) 2092 Result = ImplicitConversionSequence::Worse; 2093 else 2094 return ImplicitConversionSequence::Indistinguishable; 2095 } else if (!Context.hasSameType(SCS1.getToType(1), SCS2.getToType(1))) 2096 return ImplicitConversionSequence::Indistinguishable; 2097 2098 if (SCS1.Third == SCS2.Third) { 2099 return Context.hasSameType(SCS1.getToType(2), SCS2.getToType(2))? Result 2100 : ImplicitConversionSequence::Indistinguishable; 2101 } 2102 2103 if (SCS1.Third == ICK_Identity) 2104 return Result == ImplicitConversionSequence::Worse 2105 ? ImplicitConversionSequence::Indistinguishable 2106 : ImplicitConversionSequence::Better; 2107 2108 if (SCS2.Third == ICK_Identity) 2109 return Result == ImplicitConversionSequence::Better 2110 ? ImplicitConversionSequence::Indistinguishable 2111 : ImplicitConversionSequence::Worse; 2112 2113 return ImplicitConversionSequence::Indistinguishable; 2114} 2115 2116/// CompareStandardConversionSequences - Compare two standard 2117/// conversion sequences to determine whether one is better than the 2118/// other or if they are indistinguishable (C++ 13.3.3.2p3). 2119ImplicitConversionSequence::CompareKind 2120Sema::CompareStandardConversionSequences(const StandardConversionSequence& SCS1, 2121 const StandardConversionSequence& SCS2) 2122{ 2123 // Standard conversion sequence S1 is a better conversion sequence 2124 // than standard conversion sequence S2 if (C++ 13.3.3.2p3): 2125 2126 // -- S1 is a proper subsequence of S2 (comparing the conversion 2127 // sequences in the canonical form defined by 13.3.3.1.1, 2128 // excluding any Lvalue Transformation; the identity conversion 2129 // sequence is considered to be a subsequence of any 2130 // non-identity conversion sequence) or, if not that, 2131 if (ImplicitConversionSequence::CompareKind CK 2132 = compareStandardConversionSubsets(Context, SCS1, SCS2)) 2133 return CK; 2134 2135 // -- the rank of S1 is better than the rank of S2 (by the rules 2136 // defined below), or, if not that, 2137 ImplicitConversionRank Rank1 = SCS1.getRank(); 2138 ImplicitConversionRank Rank2 = SCS2.getRank(); 2139 if (Rank1 < Rank2) 2140 return ImplicitConversionSequence::Better; 2141 else if (Rank2 < Rank1) 2142 return ImplicitConversionSequence::Worse; 2143 2144 // (C++ 13.3.3.2p4): Two conversion sequences with the same rank 2145 // are indistinguishable unless one of the following rules 2146 // applies: 2147 2148 // A conversion that is not a conversion of a pointer, or 2149 // pointer to member, to bool is better than another conversion 2150 // that is such a conversion. 2151 if (SCS1.isPointerConversionToBool() != SCS2.isPointerConversionToBool()) 2152 return SCS2.isPointerConversionToBool() 2153 ? ImplicitConversionSequence::Better 2154 : ImplicitConversionSequence::Worse; 2155 2156 // C++ [over.ics.rank]p4b2: 2157 // 2158 // If class B is derived directly or indirectly from class A, 2159 // conversion of B* to A* is better than conversion of B* to 2160 // void*, and conversion of A* to void* is better than conversion 2161 // of B* to void*. 2162 bool SCS1ConvertsToVoid 2163 = SCS1.isPointerConversionToVoidPointer(Context); 2164 bool SCS2ConvertsToVoid 2165 = SCS2.isPointerConversionToVoidPointer(Context); 2166 if (SCS1ConvertsToVoid != SCS2ConvertsToVoid) { 2167 // Exactly one of the conversion sequences is a conversion to 2168 // a void pointer; it's the worse conversion. 2169 return SCS2ConvertsToVoid ? ImplicitConversionSequence::Better 2170 : ImplicitConversionSequence::Worse; 2171 } else if (!SCS1ConvertsToVoid && !SCS2ConvertsToVoid) { 2172 // Neither conversion sequence converts to a void pointer; compare 2173 // their derived-to-base conversions. 2174 if (ImplicitConversionSequence::CompareKind DerivedCK 2175 = CompareDerivedToBaseConversions(SCS1, SCS2)) 2176 return DerivedCK; 2177 } else if (SCS1ConvertsToVoid && SCS2ConvertsToVoid) { 2178 // Both conversion sequences are conversions to void 2179 // pointers. Compare the source types to determine if there's an 2180 // inheritance relationship in their sources. 2181 QualType FromType1 = SCS1.getFromType(); 2182 QualType FromType2 = SCS2.getFromType(); 2183 2184 // Adjust the types we're converting from via the array-to-pointer 2185 // conversion, if we need to. 2186 if (SCS1.First == ICK_Array_To_Pointer) 2187 FromType1 = Context.getArrayDecayedType(FromType1); 2188 if (SCS2.First == ICK_Array_To_Pointer) 2189 FromType2 = Context.getArrayDecayedType(FromType2); 2190 2191 QualType FromPointee1 2192 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2193 QualType FromPointee2 2194 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2195 2196 if (IsDerivedFrom(FromPointee2, FromPointee1)) 2197 return ImplicitConversionSequence::Better; 2198 else if (IsDerivedFrom(FromPointee1, FromPointee2)) 2199 return ImplicitConversionSequence::Worse; 2200 2201 // Objective-C++: If one interface is more specific than the 2202 // other, it is the better one. 2203 const ObjCObjectType* FromIface1 = FromPointee1->getAs<ObjCObjectType>(); 2204 const ObjCObjectType* FromIface2 = FromPointee2->getAs<ObjCObjectType>(); 2205 if (FromIface1 && FromIface1) { 2206 if (Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 2207 return ImplicitConversionSequence::Better; 2208 else if (Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 2209 return ImplicitConversionSequence::Worse; 2210 } 2211 } 2212 2213 // Compare based on qualification conversions (C++ 13.3.3.2p3, 2214 // bullet 3). 2215 if (ImplicitConversionSequence::CompareKind QualCK 2216 = CompareQualificationConversions(SCS1, SCS2)) 2217 return QualCK; 2218 2219 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding) { 2220 // C++0x [over.ics.rank]p3b4: 2221 // -- S1 and S2 are reference bindings (8.5.3) and neither refers to an 2222 // implicit object parameter of a non-static member function declared 2223 // without a ref-qualifier, and S1 binds an rvalue reference to an 2224 // rvalue and S2 binds an lvalue reference. 2225 // FIXME: We don't know if we're dealing with the implicit object parameter, 2226 // or if the member function in this case has a ref qualifier. 2227 // (Of course, we don't have ref qualifiers yet.) 2228 if (SCS1.RRefBinding != SCS2.RRefBinding) 2229 return SCS1.RRefBinding ? ImplicitConversionSequence::Better 2230 : ImplicitConversionSequence::Worse; 2231 2232 // C++ [over.ics.rank]p3b4: 2233 // -- S1 and S2 are reference bindings (8.5.3), and the types to 2234 // which the references refer are the same type except for 2235 // top-level cv-qualifiers, and the type to which the reference 2236 // initialized by S2 refers is more cv-qualified than the type 2237 // to which the reference initialized by S1 refers. 2238 QualType T1 = SCS1.getToType(2); 2239 QualType T2 = SCS2.getToType(2); 2240 T1 = Context.getCanonicalType(T1); 2241 T2 = Context.getCanonicalType(T2); 2242 Qualifiers T1Quals, T2Quals; 2243 QualType UnqualT1 = Context.getUnqualifiedArrayType(T1, T1Quals); 2244 QualType UnqualT2 = Context.getUnqualifiedArrayType(T2, T2Quals); 2245 if (UnqualT1 == UnqualT2) { 2246 // If the type is an array type, promote the element qualifiers to the type 2247 // for comparison. 2248 if (isa<ArrayType>(T1) && T1Quals) 2249 T1 = Context.getQualifiedType(UnqualT1, T1Quals); 2250 if (isa<ArrayType>(T2) && T2Quals) 2251 T2 = Context.getQualifiedType(UnqualT2, T2Quals); 2252 if (T2.isMoreQualifiedThan(T1)) 2253 return ImplicitConversionSequence::Better; 2254 else if (T1.isMoreQualifiedThan(T2)) 2255 return ImplicitConversionSequence::Worse; 2256 } 2257 } 2258 2259 return ImplicitConversionSequence::Indistinguishable; 2260} 2261 2262/// CompareQualificationConversions - Compares two standard conversion 2263/// sequences to determine whether they can be ranked based on their 2264/// qualification conversions (C++ 13.3.3.2p3 bullet 3). 2265ImplicitConversionSequence::CompareKind 2266Sema::CompareQualificationConversions(const StandardConversionSequence& SCS1, 2267 const StandardConversionSequence& SCS2) { 2268 // C++ 13.3.3.2p3: 2269 // -- S1 and S2 differ only in their qualification conversion and 2270 // yield similar types T1 and T2 (C++ 4.4), respectively, and the 2271 // cv-qualification signature of type T1 is a proper subset of 2272 // the cv-qualification signature of type T2, and S1 is not the 2273 // deprecated string literal array-to-pointer conversion (4.2). 2274 if (SCS1.First != SCS2.First || SCS1.Second != SCS2.Second || 2275 SCS1.Third != SCS2.Third || SCS1.Third != ICK_Qualification) 2276 return ImplicitConversionSequence::Indistinguishable; 2277 2278 // FIXME: the example in the standard doesn't use a qualification 2279 // conversion (!) 2280 QualType T1 = SCS1.getToType(2); 2281 QualType T2 = SCS2.getToType(2); 2282 T1 = Context.getCanonicalType(T1); 2283 T2 = Context.getCanonicalType(T2); 2284 Qualifiers T1Quals, T2Quals; 2285 QualType UnqualT1 = Context.getUnqualifiedArrayType(T1, T1Quals); 2286 QualType UnqualT2 = Context.getUnqualifiedArrayType(T2, T2Quals); 2287 2288 // If the types are the same, we won't learn anything by unwrapped 2289 // them. 2290 if (UnqualT1 == UnqualT2) 2291 return ImplicitConversionSequence::Indistinguishable; 2292 2293 // If the type is an array type, promote the element qualifiers to the type 2294 // for comparison. 2295 if (isa<ArrayType>(T1) && T1Quals) 2296 T1 = Context.getQualifiedType(UnqualT1, T1Quals); 2297 if (isa<ArrayType>(T2) && T2Quals) 2298 T2 = Context.getQualifiedType(UnqualT2, T2Quals); 2299 2300 ImplicitConversionSequence::CompareKind Result 2301 = ImplicitConversionSequence::Indistinguishable; 2302 while (UnwrapSimilarPointerTypes(T1, T2)) { 2303 // Within each iteration of the loop, we check the qualifiers to 2304 // determine if this still looks like a qualification 2305 // conversion. Then, if all is well, we unwrap one more level of 2306 // pointers or pointers-to-members and do it all again 2307 // until there are no more pointers or pointers-to-members left 2308 // to unwrap. This essentially mimics what 2309 // IsQualificationConversion does, but here we're checking for a 2310 // strict subset of qualifiers. 2311 if (T1.getCVRQualifiers() == T2.getCVRQualifiers()) 2312 // The qualifiers are the same, so this doesn't tell us anything 2313 // about how the sequences rank. 2314 ; 2315 else if (T2.isMoreQualifiedThan(T1)) { 2316 // T1 has fewer qualifiers, so it could be the better sequence. 2317 if (Result == ImplicitConversionSequence::Worse) 2318 // Neither has qualifiers that are a subset of the other's 2319 // qualifiers. 2320 return ImplicitConversionSequence::Indistinguishable; 2321 2322 Result = ImplicitConversionSequence::Better; 2323 } else if (T1.isMoreQualifiedThan(T2)) { 2324 // T2 has fewer qualifiers, so it could be the better sequence. 2325 if (Result == ImplicitConversionSequence::Better) 2326 // Neither has qualifiers that are a subset of the other's 2327 // qualifiers. 2328 return ImplicitConversionSequence::Indistinguishable; 2329 2330 Result = ImplicitConversionSequence::Worse; 2331 } else { 2332 // Qualifiers are disjoint. 2333 return ImplicitConversionSequence::Indistinguishable; 2334 } 2335 2336 // If the types after this point are equivalent, we're done. 2337 if (Context.hasSameUnqualifiedType(T1, T2)) 2338 break; 2339 } 2340 2341 // Check that the winning standard conversion sequence isn't using 2342 // the deprecated string literal array to pointer conversion. 2343 switch (Result) { 2344 case ImplicitConversionSequence::Better: 2345 if (SCS1.DeprecatedStringLiteralToCharPtr) 2346 Result = ImplicitConversionSequence::Indistinguishable; 2347 break; 2348 2349 case ImplicitConversionSequence::Indistinguishable: 2350 break; 2351 2352 case ImplicitConversionSequence::Worse: 2353 if (SCS2.DeprecatedStringLiteralToCharPtr) 2354 Result = ImplicitConversionSequence::Indistinguishable; 2355 break; 2356 } 2357 2358 return Result; 2359} 2360 2361/// CompareDerivedToBaseConversions - Compares two standard conversion 2362/// sequences to determine whether they can be ranked based on their 2363/// various kinds of derived-to-base conversions (C++ 2364/// [over.ics.rank]p4b3). As part of these checks, we also look at 2365/// conversions between Objective-C interface types. 2366ImplicitConversionSequence::CompareKind 2367Sema::CompareDerivedToBaseConversions(const StandardConversionSequence& SCS1, 2368 const StandardConversionSequence& SCS2) { 2369 QualType FromType1 = SCS1.getFromType(); 2370 QualType ToType1 = SCS1.getToType(1); 2371 QualType FromType2 = SCS2.getFromType(); 2372 QualType ToType2 = SCS2.getToType(1); 2373 2374 // Adjust the types we're converting from via the array-to-pointer 2375 // conversion, if we need to. 2376 if (SCS1.First == ICK_Array_To_Pointer) 2377 FromType1 = Context.getArrayDecayedType(FromType1); 2378 if (SCS2.First == ICK_Array_To_Pointer) 2379 FromType2 = Context.getArrayDecayedType(FromType2); 2380 2381 // Canonicalize all of the types. 2382 FromType1 = Context.getCanonicalType(FromType1); 2383 ToType1 = Context.getCanonicalType(ToType1); 2384 FromType2 = Context.getCanonicalType(FromType2); 2385 ToType2 = Context.getCanonicalType(ToType2); 2386 2387 // C++ [over.ics.rank]p4b3: 2388 // 2389 // If class B is derived directly or indirectly from class A and 2390 // class C is derived directly or indirectly from B, 2391 // 2392 // For Objective-C, we let A, B, and C also be Objective-C 2393 // interfaces. 2394 2395 // Compare based on pointer conversions. 2396 if (SCS1.Second == ICK_Pointer_Conversion && 2397 SCS2.Second == ICK_Pointer_Conversion && 2398 /*FIXME: Remove if Objective-C id conversions get their own rank*/ 2399 FromType1->isPointerType() && FromType2->isPointerType() && 2400 ToType1->isPointerType() && ToType2->isPointerType()) { 2401 QualType FromPointee1 2402 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2403 QualType ToPointee1 2404 = ToType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2405 QualType FromPointee2 2406 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2407 QualType ToPointee2 2408 = ToType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2409 2410 const ObjCObjectType* FromIface1 = FromPointee1->getAs<ObjCObjectType>(); 2411 const ObjCObjectType* FromIface2 = FromPointee2->getAs<ObjCObjectType>(); 2412 const ObjCObjectType* ToIface1 = ToPointee1->getAs<ObjCObjectType>(); 2413 const ObjCObjectType* ToIface2 = ToPointee2->getAs<ObjCObjectType>(); 2414 2415 // -- conversion of C* to B* is better than conversion of C* to A*, 2416 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 2417 if (IsDerivedFrom(ToPointee1, ToPointee2)) 2418 return ImplicitConversionSequence::Better; 2419 else if (IsDerivedFrom(ToPointee2, ToPointee1)) 2420 return ImplicitConversionSequence::Worse; 2421 2422 if (ToIface1 && ToIface2) { 2423 if (Context.canAssignObjCInterfaces(ToIface2, ToIface1)) 2424 return ImplicitConversionSequence::Better; 2425 else if (Context.canAssignObjCInterfaces(ToIface1, ToIface2)) 2426 return ImplicitConversionSequence::Worse; 2427 } 2428 } 2429 2430 // -- conversion of B* to A* is better than conversion of C* to A*, 2431 if (FromPointee1 != FromPointee2 && ToPointee1 == ToPointee2) { 2432 if (IsDerivedFrom(FromPointee2, FromPointee1)) 2433 return ImplicitConversionSequence::Better; 2434 else if (IsDerivedFrom(FromPointee1, FromPointee2)) 2435 return ImplicitConversionSequence::Worse; 2436 2437 if (FromIface1 && FromIface2) { 2438 if (Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 2439 return ImplicitConversionSequence::Better; 2440 else if (Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 2441 return ImplicitConversionSequence::Worse; 2442 } 2443 } 2444 } 2445 2446 // Ranking of member-pointer types. 2447 if (SCS1.Second == ICK_Pointer_Member && SCS2.Second == ICK_Pointer_Member && 2448 FromType1->isMemberPointerType() && FromType2->isMemberPointerType() && 2449 ToType1->isMemberPointerType() && ToType2->isMemberPointerType()) { 2450 const MemberPointerType * FromMemPointer1 = 2451 FromType1->getAs<MemberPointerType>(); 2452 const MemberPointerType * ToMemPointer1 = 2453 ToType1->getAs<MemberPointerType>(); 2454 const MemberPointerType * FromMemPointer2 = 2455 FromType2->getAs<MemberPointerType>(); 2456 const MemberPointerType * ToMemPointer2 = 2457 ToType2->getAs<MemberPointerType>(); 2458 const Type *FromPointeeType1 = FromMemPointer1->getClass(); 2459 const Type *ToPointeeType1 = ToMemPointer1->getClass(); 2460 const Type *FromPointeeType2 = FromMemPointer2->getClass(); 2461 const Type *ToPointeeType2 = ToMemPointer2->getClass(); 2462 QualType FromPointee1 = QualType(FromPointeeType1, 0).getUnqualifiedType(); 2463 QualType ToPointee1 = QualType(ToPointeeType1, 0).getUnqualifiedType(); 2464 QualType FromPointee2 = QualType(FromPointeeType2, 0).getUnqualifiedType(); 2465 QualType ToPointee2 = QualType(ToPointeeType2, 0).getUnqualifiedType(); 2466 // conversion of A::* to B::* is better than conversion of A::* to C::*, 2467 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 2468 if (IsDerivedFrom(ToPointee1, ToPointee2)) 2469 return ImplicitConversionSequence::Worse; 2470 else if (IsDerivedFrom(ToPointee2, ToPointee1)) 2471 return ImplicitConversionSequence::Better; 2472 } 2473 // conversion of B::* to C::* is better than conversion of A::* to C::* 2474 if (ToPointee1 == ToPointee2 && FromPointee1 != FromPointee2) { 2475 if (IsDerivedFrom(FromPointee1, FromPointee2)) 2476 return ImplicitConversionSequence::Better; 2477 else if (IsDerivedFrom(FromPointee2, FromPointee1)) 2478 return ImplicitConversionSequence::Worse; 2479 } 2480 } 2481 2482 if (SCS1.Second == ICK_Derived_To_Base) { 2483 // -- conversion of C to B is better than conversion of C to A, 2484 // -- binding of an expression of type C to a reference of type 2485 // B& is better than binding an expression of type C to a 2486 // reference of type A&, 2487 if (Context.hasSameUnqualifiedType(FromType1, FromType2) && 2488 !Context.hasSameUnqualifiedType(ToType1, ToType2)) { 2489 if (IsDerivedFrom(ToType1, ToType2)) 2490 return ImplicitConversionSequence::Better; 2491 else if (IsDerivedFrom(ToType2, ToType1)) 2492 return ImplicitConversionSequence::Worse; 2493 } 2494 2495 // -- conversion of B to A is better than conversion of C to A. 2496 // -- binding of an expression of type B to a reference of type 2497 // A& is better than binding an expression of type C to a 2498 // reference of type A&, 2499 if (!Context.hasSameUnqualifiedType(FromType1, FromType2) && 2500 Context.hasSameUnqualifiedType(ToType1, ToType2)) { 2501 if (IsDerivedFrom(FromType2, FromType1)) 2502 return ImplicitConversionSequence::Better; 2503 else if (IsDerivedFrom(FromType1, FromType2)) 2504 return ImplicitConversionSequence::Worse; 2505 } 2506 } 2507 2508 return ImplicitConversionSequence::Indistinguishable; 2509} 2510 2511/// CompareReferenceRelationship - Compare the two types T1 and T2 to 2512/// determine whether they are reference-related, 2513/// reference-compatible, reference-compatible with added 2514/// qualification, or incompatible, for use in C++ initialization by 2515/// reference (C++ [dcl.ref.init]p4). Neither type can be a reference 2516/// type, and the first type (T1) is the pointee type of the reference 2517/// type being initialized. 2518Sema::ReferenceCompareResult 2519Sema::CompareReferenceRelationship(SourceLocation Loc, 2520 QualType OrigT1, QualType OrigT2, 2521 bool& DerivedToBase) { 2522 assert(!OrigT1->isReferenceType() && 2523 "T1 must be the pointee type of the reference type"); 2524 assert(!OrigT2->isReferenceType() && "T2 cannot be a reference type"); 2525 2526 QualType T1 = Context.getCanonicalType(OrigT1); 2527 QualType T2 = Context.getCanonicalType(OrigT2); 2528 Qualifiers T1Quals, T2Quals; 2529 QualType UnqualT1 = Context.getUnqualifiedArrayType(T1, T1Quals); 2530 QualType UnqualT2 = Context.getUnqualifiedArrayType(T2, T2Quals); 2531 2532 // C++ [dcl.init.ref]p4: 2533 // Given types "cv1 T1" and "cv2 T2," "cv1 T1" is 2534 // reference-related to "cv2 T2" if T1 is the same type as T2, or 2535 // T1 is a base class of T2. 2536 if (UnqualT1 == UnqualT2) 2537 DerivedToBase = false; 2538 else if (!RequireCompleteType(Loc, OrigT2, PDiag()) && 2539 IsDerivedFrom(UnqualT2, UnqualT1)) 2540 DerivedToBase = true; 2541 else 2542 return Ref_Incompatible; 2543 2544 // At this point, we know that T1 and T2 are reference-related (at 2545 // least). 2546 2547 // If the type is an array type, promote the element qualifiers to the type 2548 // for comparison. 2549 if (isa<ArrayType>(T1) && T1Quals) 2550 T1 = Context.getQualifiedType(UnqualT1, T1Quals); 2551 if (isa<ArrayType>(T2) && T2Quals) 2552 T2 = Context.getQualifiedType(UnqualT2, T2Quals); 2553 2554 // C++ [dcl.init.ref]p4: 2555 // "cv1 T1" is reference-compatible with "cv2 T2" if T1 is 2556 // reference-related to T2 and cv1 is the same cv-qualification 2557 // as, or greater cv-qualification than, cv2. For purposes of 2558 // overload resolution, cases for which cv1 is greater 2559 // cv-qualification than cv2 are identified as 2560 // reference-compatible with added qualification (see 13.3.3.2). 2561 if (T1Quals.getCVRQualifiers() == T2Quals.getCVRQualifiers()) 2562 return Ref_Compatible; 2563 else if (T1.isMoreQualifiedThan(T2)) 2564 return Ref_Compatible_With_Added_Qualification; 2565 else 2566 return Ref_Related; 2567} 2568 2569/// \brief Compute an implicit conversion sequence for reference 2570/// initialization. 2571static ImplicitConversionSequence 2572TryReferenceInit(Sema &S, Expr *&Init, QualType DeclType, 2573 SourceLocation DeclLoc, 2574 bool SuppressUserConversions, 2575 bool AllowExplicit) { 2576 assert(DeclType->isReferenceType() && "Reference init needs a reference"); 2577 2578 // Most paths end in a failed conversion. 2579 ImplicitConversionSequence ICS; 2580 ICS.setBad(BadConversionSequence::no_conversion, Init, DeclType); 2581 2582 QualType T1 = DeclType->getAs<ReferenceType>()->getPointeeType(); 2583 QualType T2 = Init->getType(); 2584 2585 // If the initializer is the address of an overloaded function, try 2586 // to resolve the overloaded function. If all goes well, T2 is the 2587 // type of the resulting function. 2588 if (S.Context.getCanonicalType(T2) == S.Context.OverloadTy) { 2589 DeclAccessPair Found; 2590 if (FunctionDecl *Fn = S.ResolveAddressOfOverloadedFunction(Init, DeclType, 2591 false, Found)) 2592 T2 = Fn->getType(); 2593 } 2594 2595 // Compute some basic properties of the types and the initializer. 2596 bool isRValRef = DeclType->isRValueReferenceType(); 2597 bool DerivedToBase = false; 2598 Expr::isLvalueResult InitLvalue = Init->isLvalue(S.Context); 2599 Sema::ReferenceCompareResult RefRelationship 2600 = S.CompareReferenceRelationship(DeclLoc, T1, T2, DerivedToBase); 2601 2602 2603 // C++ [over.ics.ref]p3: 2604 // Except for an implicit object parameter, for which see 13.3.1, 2605 // a standard conversion sequence cannot be formed if it requires 2606 // binding an lvalue reference to non-const to an rvalue or 2607 // binding an rvalue reference to an lvalue. 2608 // 2609 // FIXME: DPG doesn't trust this code. It seems far too early to 2610 // abort because of a binding of an rvalue reference to an lvalue. 2611 if (isRValRef && InitLvalue == Expr::LV_Valid) 2612 return ICS; 2613 2614 // C++0x [dcl.init.ref]p16: 2615 // A reference to type "cv1 T1" is initialized by an expression 2616 // of type "cv2 T2" as follows: 2617 2618 // -- If the initializer expression 2619 // -- is an lvalue (but is not a bit-field), and "cv1 T1" is 2620 // reference-compatible with "cv2 T2," or 2621 // 2622 // Per C++ [over.ics.ref]p4, we don't check the bit-field property here. 2623 if (InitLvalue == Expr::LV_Valid && 2624 RefRelationship >= Sema::Ref_Compatible_With_Added_Qualification) { 2625 // C++ [over.ics.ref]p1: 2626 // When a parameter of reference type binds directly (8.5.3) 2627 // to an argument expression, the implicit conversion sequence 2628 // is the identity conversion, unless the argument expression 2629 // has a type that is a derived class of the parameter type, 2630 // in which case the implicit conversion sequence is a 2631 // derived-to-base Conversion (13.3.3.1). 2632 ICS.setStandard(); 2633 ICS.Standard.First = ICK_Identity; 2634 ICS.Standard.Second = DerivedToBase? ICK_Derived_To_Base : ICK_Identity; 2635 ICS.Standard.Third = ICK_Identity; 2636 ICS.Standard.FromTypePtr = T2.getAsOpaquePtr(); 2637 ICS.Standard.setToType(0, T2); 2638 ICS.Standard.setToType(1, T1); 2639 ICS.Standard.setToType(2, T1); 2640 ICS.Standard.ReferenceBinding = true; 2641 ICS.Standard.DirectBinding = true; 2642 ICS.Standard.RRefBinding = false; 2643 ICS.Standard.CopyConstructor = 0; 2644 2645 // Nothing more to do: the inaccessibility/ambiguity check for 2646 // derived-to-base conversions is suppressed when we're 2647 // computing the implicit conversion sequence (C++ 2648 // [over.best.ics]p2). 2649 return ICS; 2650 } 2651 2652 // -- has a class type (i.e., T2 is a class type), where T1 is 2653 // not reference-related to T2, and can be implicitly 2654 // converted to an lvalue of type "cv3 T3," where "cv1 T1" 2655 // is reference-compatible with "cv3 T3" 92) (this 2656 // conversion is selected by enumerating the applicable 2657 // conversion functions (13.3.1.6) and choosing the best 2658 // one through overload resolution (13.3)), 2659 if (!isRValRef && !SuppressUserConversions && T2->isRecordType() && 2660 !S.RequireCompleteType(DeclLoc, T2, 0) && 2661 RefRelationship == Sema::Ref_Incompatible) { 2662 CXXRecordDecl *T2RecordDecl 2663 = dyn_cast<CXXRecordDecl>(T2->getAs<RecordType>()->getDecl()); 2664 2665 OverloadCandidateSet CandidateSet(DeclLoc); 2666 const UnresolvedSetImpl *Conversions 2667 = T2RecordDecl->getVisibleConversionFunctions(); 2668 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 2669 E = Conversions->end(); I != E; ++I) { 2670 NamedDecl *D = *I; 2671 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(D->getDeclContext()); 2672 if (isa<UsingShadowDecl>(D)) 2673 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 2674 2675 FunctionTemplateDecl *ConvTemplate 2676 = dyn_cast<FunctionTemplateDecl>(D); 2677 CXXConversionDecl *Conv; 2678 if (ConvTemplate) 2679 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 2680 else 2681 Conv = cast<CXXConversionDecl>(D); 2682 2683 // If the conversion function doesn't return a reference type, 2684 // it can't be considered for this conversion. 2685 if (Conv->getConversionType()->isLValueReferenceType() && 2686 (AllowExplicit || !Conv->isExplicit())) { 2687 if (ConvTemplate) 2688 S.AddTemplateConversionCandidate(ConvTemplate, I.getPair(), ActingDC, 2689 Init, DeclType, CandidateSet); 2690 else 2691 S.AddConversionCandidate(Conv, I.getPair(), ActingDC, Init, 2692 DeclType, CandidateSet); 2693 } 2694 } 2695 2696 OverloadCandidateSet::iterator Best; 2697 switch (S.BestViableFunction(CandidateSet, DeclLoc, Best)) { 2698 case OR_Success: 2699 // C++ [over.ics.ref]p1: 2700 // 2701 // [...] If the parameter binds directly to the result of 2702 // applying a conversion function to the argument 2703 // expression, the implicit conversion sequence is a 2704 // user-defined conversion sequence (13.3.3.1.2), with the 2705 // second standard conversion sequence either an identity 2706 // conversion or, if the conversion function returns an 2707 // entity of a type that is a derived class of the parameter 2708 // type, a derived-to-base Conversion. 2709 if (!Best->FinalConversion.DirectBinding) 2710 break; 2711 2712 ICS.setUserDefined(); 2713 ICS.UserDefined.Before = Best->Conversions[0].Standard; 2714 ICS.UserDefined.After = Best->FinalConversion; 2715 ICS.UserDefined.ConversionFunction = Best->Function; 2716 ICS.UserDefined.EllipsisConversion = false; 2717 assert(ICS.UserDefined.After.ReferenceBinding && 2718 ICS.UserDefined.After.DirectBinding && 2719 "Expected a direct reference binding!"); 2720 return ICS; 2721 2722 case OR_Ambiguous: 2723 ICS.setAmbiguous(); 2724 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 2725 Cand != CandidateSet.end(); ++Cand) 2726 if (Cand->Viable) 2727 ICS.Ambiguous.addConversion(Cand->Function); 2728 return ICS; 2729 2730 case OR_No_Viable_Function: 2731 case OR_Deleted: 2732 // There was no suitable conversion, or we found a deleted 2733 // conversion; continue with other checks. 2734 break; 2735 } 2736 } 2737 2738 // -- Otherwise, the reference shall be to a non-volatile const 2739 // type (i.e., cv1 shall be const), or the reference shall be an 2740 // rvalue reference and the initializer expression shall be an rvalue. 2741 // 2742 // We actually handle one oddity of C++ [over.ics.ref] at this 2743 // point, which is that, due to p2 (which short-circuits reference 2744 // binding by only attempting a simple conversion for non-direct 2745 // bindings) and p3's strange wording, we allow a const volatile 2746 // reference to bind to an rvalue. Hence the check for the presence 2747 // of "const" rather than checking for "const" being the only 2748 // qualifier. 2749 if (!isRValRef && !T1.isConstQualified()) 2750 return ICS; 2751 2752 // -- if T2 is a class type and 2753 // -- the initializer expression is an rvalue and "cv1 T1" 2754 // is reference-compatible with "cv2 T2," or 2755 // 2756 // -- T1 is not reference-related to T2 and the initializer 2757 // expression can be implicitly converted to an rvalue 2758 // of type "cv3 T3" (this conversion is selected by 2759 // enumerating the applicable conversion functions 2760 // (13.3.1.6) and choosing the best one through overload 2761 // resolution (13.3)), 2762 // 2763 // then the reference is bound to the initializer 2764 // expression rvalue in the first case and to the object 2765 // that is the result of the conversion in the second case 2766 // (or, in either case, to the appropriate base class 2767 // subobject of the object). 2768 // 2769 // We're only checking the first case here, which is a direct 2770 // binding in C++0x but not in C++03. 2771 if (InitLvalue != Expr::LV_Valid && T2->isRecordType() && 2772 RefRelationship >= Sema::Ref_Compatible_With_Added_Qualification) { 2773 ICS.setStandard(); 2774 ICS.Standard.First = ICK_Identity; 2775 ICS.Standard.Second = DerivedToBase? ICK_Derived_To_Base : ICK_Identity; 2776 ICS.Standard.Third = ICK_Identity; 2777 ICS.Standard.FromTypePtr = T2.getAsOpaquePtr(); 2778 ICS.Standard.setToType(0, T2); 2779 ICS.Standard.setToType(1, T1); 2780 ICS.Standard.setToType(2, T1); 2781 ICS.Standard.ReferenceBinding = true; 2782 ICS.Standard.DirectBinding = S.getLangOptions().CPlusPlus0x; 2783 ICS.Standard.RRefBinding = isRValRef; 2784 ICS.Standard.CopyConstructor = 0; 2785 return ICS; 2786 } 2787 2788 // -- Otherwise, a temporary of type "cv1 T1" is created and 2789 // initialized from the initializer expression using the 2790 // rules for a non-reference copy initialization (8.5). The 2791 // reference is then bound to the temporary. If T1 is 2792 // reference-related to T2, cv1 must be the same 2793 // cv-qualification as, or greater cv-qualification than, 2794 // cv2; otherwise, the program is ill-formed. 2795 if (RefRelationship == Sema::Ref_Related) { 2796 // If cv1 == cv2 or cv1 is a greater cv-qualified than cv2, then 2797 // we would be reference-compatible or reference-compatible with 2798 // added qualification. But that wasn't the case, so the reference 2799 // initialization fails. 2800 return ICS; 2801 } 2802 2803 // If at least one of the types is a class type, the types are not 2804 // related, and we aren't allowed any user conversions, the 2805 // reference binding fails. This case is important for breaking 2806 // recursion, since TryImplicitConversion below will attempt to 2807 // create a temporary through the use of a copy constructor. 2808 if (SuppressUserConversions && RefRelationship == Sema::Ref_Incompatible && 2809 (T1->isRecordType() || T2->isRecordType())) 2810 return ICS; 2811 2812 // C++ [over.ics.ref]p2: 2813 // When a parameter of reference type is not bound directly to 2814 // an argument expression, the conversion sequence is the one 2815 // required to convert the argument expression to the 2816 // underlying type of the reference according to 2817 // 13.3.3.1. Conceptually, this conversion sequence corresponds 2818 // to copy-initializing a temporary of the underlying type with 2819 // the argument expression. Any difference in top-level 2820 // cv-qualification is subsumed by the initialization itself 2821 // and does not constitute a conversion. 2822 ICS = S.TryImplicitConversion(Init, T1, SuppressUserConversions, 2823 /*AllowExplicit=*/false, 2824 /*InOverloadResolution=*/false); 2825 2826 // Of course, that's still a reference binding. 2827 if (ICS.isStandard()) { 2828 ICS.Standard.ReferenceBinding = true; 2829 ICS.Standard.RRefBinding = isRValRef; 2830 } else if (ICS.isUserDefined()) { 2831 ICS.UserDefined.After.ReferenceBinding = true; 2832 ICS.UserDefined.After.RRefBinding = isRValRef; 2833 } 2834 return ICS; 2835} 2836 2837/// TryCopyInitialization - Try to copy-initialize a value of type 2838/// ToType from the expression From. Return the implicit conversion 2839/// sequence required to pass this argument, which may be a bad 2840/// conversion sequence (meaning that the argument cannot be passed to 2841/// a parameter of this type). If @p SuppressUserConversions, then we 2842/// do not permit any user-defined conversion sequences. 2843static ImplicitConversionSequence 2844TryCopyInitialization(Sema &S, Expr *From, QualType ToType, 2845 bool SuppressUserConversions, 2846 bool InOverloadResolution) { 2847 if (ToType->isReferenceType()) 2848 return TryReferenceInit(S, From, ToType, 2849 /*FIXME:*/From->getLocStart(), 2850 SuppressUserConversions, 2851 /*AllowExplicit=*/false); 2852 2853 return S.TryImplicitConversion(From, ToType, 2854 SuppressUserConversions, 2855 /*AllowExplicit=*/false, 2856 InOverloadResolution); 2857} 2858 2859/// TryObjectArgumentInitialization - Try to initialize the object 2860/// parameter of the given member function (@c Method) from the 2861/// expression @p From. 2862ImplicitConversionSequence 2863Sema::TryObjectArgumentInitialization(QualType OrigFromType, 2864 CXXMethodDecl *Method, 2865 CXXRecordDecl *ActingContext) { 2866 QualType ClassType = Context.getTypeDeclType(ActingContext); 2867 // [class.dtor]p2: A destructor can be invoked for a const, volatile or 2868 // const volatile object. 2869 unsigned Quals = isa<CXXDestructorDecl>(Method) ? 2870 Qualifiers::Const | Qualifiers::Volatile : Method->getTypeQualifiers(); 2871 QualType ImplicitParamType = Context.getCVRQualifiedType(ClassType, Quals); 2872 2873 // Set up the conversion sequence as a "bad" conversion, to allow us 2874 // to exit early. 2875 ImplicitConversionSequence ICS; 2876 2877 // We need to have an object of class type. 2878 QualType FromType = OrigFromType; 2879 if (const PointerType *PT = FromType->getAs<PointerType>()) 2880 FromType = PT->getPointeeType(); 2881 2882 assert(FromType->isRecordType()); 2883 2884 // The implicit object parameter is has the type "reference to cv X", 2885 // where X is the class of which the function is a member 2886 // (C++ [over.match.funcs]p4). However, when finding an implicit 2887 // conversion sequence for the argument, we are not allowed to 2888 // create temporaries or perform user-defined conversions 2889 // (C++ [over.match.funcs]p5). We perform a simplified version of 2890 // reference binding here, that allows class rvalues to bind to 2891 // non-constant references. 2892 2893 // First check the qualifiers. We don't care about lvalue-vs-rvalue 2894 // with the implicit object parameter (C++ [over.match.funcs]p5). 2895 QualType FromTypeCanon = Context.getCanonicalType(FromType); 2896 if (ImplicitParamType.getCVRQualifiers() 2897 != FromTypeCanon.getLocalCVRQualifiers() && 2898 !ImplicitParamType.isAtLeastAsQualifiedAs(FromTypeCanon)) { 2899 ICS.setBad(BadConversionSequence::bad_qualifiers, 2900 OrigFromType, ImplicitParamType); 2901 return ICS; 2902 } 2903 2904 // Check that we have either the same type or a derived type. It 2905 // affects the conversion rank. 2906 QualType ClassTypeCanon = Context.getCanonicalType(ClassType); 2907 ImplicitConversionKind SecondKind; 2908 if (ClassTypeCanon == FromTypeCanon.getLocalUnqualifiedType()) { 2909 SecondKind = ICK_Identity; 2910 } else if (IsDerivedFrom(FromType, ClassType)) 2911 SecondKind = ICK_Derived_To_Base; 2912 else { 2913 ICS.setBad(BadConversionSequence::unrelated_class, 2914 FromType, ImplicitParamType); 2915 return ICS; 2916 } 2917 2918 // Success. Mark this as a reference binding. 2919 ICS.setStandard(); 2920 ICS.Standard.setAsIdentityConversion(); 2921 ICS.Standard.Second = SecondKind; 2922 ICS.Standard.setFromType(FromType); 2923 ICS.Standard.setAllToTypes(ImplicitParamType); 2924 ICS.Standard.ReferenceBinding = true; 2925 ICS.Standard.DirectBinding = true; 2926 ICS.Standard.RRefBinding = false; 2927 return ICS; 2928} 2929 2930/// PerformObjectArgumentInitialization - Perform initialization of 2931/// the implicit object parameter for the given Method with the given 2932/// expression. 2933bool 2934Sema::PerformObjectArgumentInitialization(Expr *&From, 2935 NestedNameSpecifier *Qualifier, 2936 NamedDecl *FoundDecl, 2937 CXXMethodDecl *Method) { 2938 QualType FromRecordType, DestType; 2939 QualType ImplicitParamRecordType = 2940 Method->getThisType(Context)->getAs<PointerType>()->getPointeeType(); 2941 2942 if (const PointerType *PT = From->getType()->getAs<PointerType>()) { 2943 FromRecordType = PT->getPointeeType(); 2944 DestType = Method->getThisType(Context); 2945 } else { 2946 FromRecordType = From->getType(); 2947 DestType = ImplicitParamRecordType; 2948 } 2949 2950 // Note that we always use the true parent context when performing 2951 // the actual argument initialization. 2952 ImplicitConversionSequence ICS 2953 = TryObjectArgumentInitialization(From->getType(), Method, 2954 Method->getParent()); 2955 if (ICS.isBad()) 2956 return Diag(From->getSourceRange().getBegin(), 2957 diag::err_implicit_object_parameter_init) 2958 << ImplicitParamRecordType << FromRecordType << From->getSourceRange(); 2959 2960 if (ICS.Standard.Second == ICK_Derived_To_Base) 2961 return PerformObjectMemberConversion(From, Qualifier, FoundDecl, Method); 2962 2963 if (!Context.hasSameType(From->getType(), DestType)) 2964 ImpCastExprToType(From, DestType, CastExpr::CK_NoOp, 2965 /*isLvalue=*/!From->getType()->isPointerType()); 2966 return false; 2967} 2968 2969/// TryContextuallyConvertToBool - Attempt to contextually convert the 2970/// expression From to bool (C++0x [conv]p3). 2971ImplicitConversionSequence Sema::TryContextuallyConvertToBool(Expr *From) { 2972 // FIXME: This is pretty broken. 2973 return TryImplicitConversion(From, Context.BoolTy, 2974 // FIXME: Are these flags correct? 2975 /*SuppressUserConversions=*/false, 2976 /*AllowExplicit=*/true, 2977 /*InOverloadResolution=*/false); 2978} 2979 2980/// PerformContextuallyConvertToBool - Perform a contextual conversion 2981/// of the expression From to bool (C++0x [conv]p3). 2982bool Sema::PerformContextuallyConvertToBool(Expr *&From) { 2983 ImplicitConversionSequence ICS = TryContextuallyConvertToBool(From); 2984 if (!ICS.isBad()) 2985 return PerformImplicitConversion(From, Context.BoolTy, ICS, AA_Converting); 2986 2987 if (!DiagnoseMultipleUserDefinedConversion(From, Context.BoolTy)) 2988 return Diag(From->getSourceRange().getBegin(), 2989 diag::err_typecheck_bool_condition) 2990 << From->getType() << From->getSourceRange(); 2991 return true; 2992} 2993 2994/// TryContextuallyConvertToObjCId - Attempt to contextually convert the 2995/// expression From to 'id'. 2996ImplicitConversionSequence Sema::TryContextuallyConvertToObjCId(Expr *From) { 2997 QualType Ty = Context.getObjCIdType(); 2998 return TryImplicitConversion(From, Ty, 2999 // FIXME: Are these flags correct? 3000 /*SuppressUserConversions=*/false, 3001 /*AllowExplicit=*/true, 3002 /*InOverloadResolution=*/false); 3003} 3004 3005/// PerformContextuallyConvertToObjCId - Perform a contextual conversion 3006/// of the expression From to 'id'. 3007bool Sema::PerformContextuallyConvertToObjCId(Expr *&From) { 3008 QualType Ty = Context.getObjCIdType(); 3009 ImplicitConversionSequence ICS = TryContextuallyConvertToObjCId(From); 3010 if (!ICS.isBad()) 3011 return PerformImplicitConversion(From, Ty, ICS, AA_Converting); 3012 return true; 3013} 3014 3015/// AddOverloadCandidate - Adds the given function to the set of 3016/// candidate functions, using the given function call arguments. If 3017/// @p SuppressUserConversions, then don't allow user-defined 3018/// conversions via constructors or conversion operators. 3019/// 3020/// \para PartialOverloading true if we are performing "partial" overloading 3021/// based on an incomplete set of function arguments. This feature is used by 3022/// code completion. 3023void 3024Sema::AddOverloadCandidate(FunctionDecl *Function, 3025 DeclAccessPair FoundDecl, 3026 Expr **Args, unsigned NumArgs, 3027 OverloadCandidateSet& CandidateSet, 3028 bool SuppressUserConversions, 3029 bool PartialOverloading) { 3030 const FunctionProtoType* Proto 3031 = dyn_cast<FunctionProtoType>(Function->getType()->getAs<FunctionType>()); 3032 assert(Proto && "Functions without a prototype cannot be overloaded"); 3033 assert(!Function->getDescribedFunctionTemplate() && 3034 "Use AddTemplateOverloadCandidate for function templates"); 3035 3036 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Function)) { 3037 if (!isa<CXXConstructorDecl>(Method)) { 3038 // If we get here, it's because we're calling a member function 3039 // that is named without a member access expression (e.g., 3040 // "this->f") that was either written explicitly or created 3041 // implicitly. This can happen with a qualified call to a member 3042 // function, e.g., X::f(). We use an empty type for the implied 3043 // object argument (C++ [over.call.func]p3), and the acting context 3044 // is irrelevant. 3045 AddMethodCandidate(Method, FoundDecl, Method->getParent(), 3046 QualType(), Args, NumArgs, CandidateSet, 3047 SuppressUserConversions); 3048 return; 3049 } 3050 // We treat a constructor like a non-member function, since its object 3051 // argument doesn't participate in overload resolution. 3052 } 3053 3054 if (!CandidateSet.isNewCandidate(Function)) 3055 return; 3056 3057 // Overload resolution is always an unevaluated context. 3058 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 3059 3060 if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(Function)){ 3061 // C++ [class.copy]p3: 3062 // A member function template is never instantiated to perform the copy 3063 // of a class object to an object of its class type. 3064 QualType ClassType = Context.getTypeDeclType(Constructor->getParent()); 3065 if (NumArgs == 1 && 3066 Constructor->isCopyConstructorLikeSpecialization() && 3067 (Context.hasSameUnqualifiedType(ClassType, Args[0]->getType()) || 3068 IsDerivedFrom(Args[0]->getType(), ClassType))) 3069 return; 3070 } 3071 3072 // Add this candidate 3073 CandidateSet.push_back(OverloadCandidate()); 3074 OverloadCandidate& Candidate = CandidateSet.back(); 3075 Candidate.FoundDecl = FoundDecl; 3076 Candidate.Function = Function; 3077 Candidate.Viable = true; 3078 Candidate.IsSurrogate = false; 3079 Candidate.IgnoreObjectArgument = false; 3080 3081 unsigned NumArgsInProto = Proto->getNumArgs(); 3082 3083 // (C++ 13.3.2p2): A candidate function having fewer than m 3084 // parameters is viable only if it has an ellipsis in its parameter 3085 // list (8.3.5). 3086 if ((NumArgs + (PartialOverloading && NumArgs)) > NumArgsInProto && 3087 !Proto->isVariadic()) { 3088 Candidate.Viable = false; 3089 Candidate.FailureKind = ovl_fail_too_many_arguments; 3090 return; 3091 } 3092 3093 // (C++ 13.3.2p2): A candidate function having more than m parameters 3094 // is viable only if the (m+1)st parameter has a default argument 3095 // (8.3.6). For the purposes of overload resolution, the 3096 // parameter list is truncated on the right, so that there are 3097 // exactly m parameters. 3098 unsigned MinRequiredArgs = Function->getMinRequiredArguments(); 3099 if (NumArgs < MinRequiredArgs && !PartialOverloading) { 3100 // Not enough arguments. 3101 Candidate.Viable = false; 3102 Candidate.FailureKind = ovl_fail_too_few_arguments; 3103 return; 3104 } 3105 3106 // Determine the implicit conversion sequences for each of the 3107 // arguments. 3108 Candidate.Conversions.resize(NumArgs); 3109 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 3110 if (ArgIdx < NumArgsInProto) { 3111 // (C++ 13.3.2p3): for F to be a viable function, there shall 3112 // exist for each argument an implicit conversion sequence 3113 // (13.3.3.1) that converts that argument to the corresponding 3114 // parameter of F. 3115 QualType ParamType = Proto->getArgType(ArgIdx); 3116 Candidate.Conversions[ArgIdx] 3117 = TryCopyInitialization(*this, Args[ArgIdx], ParamType, 3118 SuppressUserConversions, 3119 /*InOverloadResolution=*/true); 3120 if (Candidate.Conversions[ArgIdx].isBad()) { 3121 Candidate.Viable = false; 3122 Candidate.FailureKind = ovl_fail_bad_conversion; 3123 break; 3124 } 3125 } else { 3126 // (C++ 13.3.2p2): For the purposes of overload resolution, any 3127 // argument for which there is no corresponding parameter is 3128 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 3129 Candidate.Conversions[ArgIdx].setEllipsis(); 3130 } 3131 } 3132} 3133 3134/// \brief Add all of the function declarations in the given function set to 3135/// the overload canddiate set. 3136void Sema::AddFunctionCandidates(const UnresolvedSetImpl &Fns, 3137 Expr **Args, unsigned NumArgs, 3138 OverloadCandidateSet& CandidateSet, 3139 bool SuppressUserConversions) { 3140 for (UnresolvedSetIterator F = Fns.begin(), E = Fns.end(); F != E; ++F) { 3141 NamedDecl *D = F.getDecl()->getUnderlyingDecl(); 3142 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { 3143 if (isa<CXXMethodDecl>(FD) && !cast<CXXMethodDecl>(FD)->isStatic()) 3144 AddMethodCandidate(cast<CXXMethodDecl>(FD), F.getPair(), 3145 cast<CXXMethodDecl>(FD)->getParent(), 3146 Args[0]->getType(), Args + 1, NumArgs - 1, 3147 CandidateSet, SuppressUserConversions); 3148 else 3149 AddOverloadCandidate(FD, F.getPair(), Args, NumArgs, CandidateSet, 3150 SuppressUserConversions); 3151 } else { 3152 FunctionTemplateDecl *FunTmpl = cast<FunctionTemplateDecl>(D); 3153 if (isa<CXXMethodDecl>(FunTmpl->getTemplatedDecl()) && 3154 !cast<CXXMethodDecl>(FunTmpl->getTemplatedDecl())->isStatic()) 3155 AddMethodTemplateCandidate(FunTmpl, F.getPair(), 3156 cast<CXXRecordDecl>(FunTmpl->getDeclContext()), 3157 /*FIXME: explicit args */ 0, 3158 Args[0]->getType(), Args + 1, NumArgs - 1, 3159 CandidateSet, 3160 SuppressUserConversions); 3161 else 3162 AddTemplateOverloadCandidate(FunTmpl, F.getPair(), 3163 /*FIXME: explicit args */ 0, 3164 Args, NumArgs, CandidateSet, 3165 SuppressUserConversions); 3166 } 3167 } 3168} 3169 3170/// AddMethodCandidate - Adds a named decl (which is some kind of 3171/// method) as a method candidate to the given overload set. 3172void Sema::AddMethodCandidate(DeclAccessPair FoundDecl, 3173 QualType ObjectType, 3174 Expr **Args, unsigned NumArgs, 3175 OverloadCandidateSet& CandidateSet, 3176 bool SuppressUserConversions) { 3177 NamedDecl *Decl = FoundDecl.getDecl(); 3178 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(Decl->getDeclContext()); 3179 3180 if (isa<UsingShadowDecl>(Decl)) 3181 Decl = cast<UsingShadowDecl>(Decl)->getTargetDecl(); 3182 3183 if (FunctionTemplateDecl *TD = dyn_cast<FunctionTemplateDecl>(Decl)) { 3184 assert(isa<CXXMethodDecl>(TD->getTemplatedDecl()) && 3185 "Expected a member function template"); 3186 AddMethodTemplateCandidate(TD, FoundDecl, ActingContext, 3187 /*ExplicitArgs*/ 0, 3188 ObjectType, Args, NumArgs, 3189 CandidateSet, 3190 SuppressUserConversions); 3191 } else { 3192 AddMethodCandidate(cast<CXXMethodDecl>(Decl), FoundDecl, ActingContext, 3193 ObjectType, Args, NumArgs, 3194 CandidateSet, SuppressUserConversions); 3195 } 3196} 3197 3198/// AddMethodCandidate - Adds the given C++ member function to the set 3199/// of candidate functions, using the given function call arguments 3200/// and the object argument (@c Object). For example, in a call 3201/// @c o.f(a1,a2), @c Object will contain @c o and @c Args will contain 3202/// both @c a1 and @c a2. If @p SuppressUserConversions, then don't 3203/// allow user-defined conversions via constructors or conversion 3204/// operators. 3205void 3206Sema::AddMethodCandidate(CXXMethodDecl *Method, DeclAccessPair FoundDecl, 3207 CXXRecordDecl *ActingContext, QualType ObjectType, 3208 Expr **Args, unsigned NumArgs, 3209 OverloadCandidateSet& CandidateSet, 3210 bool SuppressUserConversions) { 3211 const FunctionProtoType* Proto 3212 = dyn_cast<FunctionProtoType>(Method->getType()->getAs<FunctionType>()); 3213 assert(Proto && "Methods without a prototype cannot be overloaded"); 3214 assert(!isa<CXXConstructorDecl>(Method) && 3215 "Use AddOverloadCandidate for constructors"); 3216 3217 if (!CandidateSet.isNewCandidate(Method)) 3218 return; 3219 3220 // Overload resolution is always an unevaluated context. 3221 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 3222 3223 // Add this candidate 3224 CandidateSet.push_back(OverloadCandidate()); 3225 OverloadCandidate& Candidate = CandidateSet.back(); 3226 Candidate.FoundDecl = FoundDecl; 3227 Candidate.Function = Method; 3228 Candidate.IsSurrogate = false; 3229 Candidate.IgnoreObjectArgument = false; 3230 3231 unsigned NumArgsInProto = Proto->getNumArgs(); 3232 3233 // (C++ 13.3.2p2): A candidate function having fewer than m 3234 // parameters is viable only if it has an ellipsis in its parameter 3235 // list (8.3.5). 3236 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 3237 Candidate.Viable = false; 3238 Candidate.FailureKind = ovl_fail_too_many_arguments; 3239 return; 3240 } 3241 3242 // (C++ 13.3.2p2): A candidate function having more than m parameters 3243 // is viable only if the (m+1)st parameter has a default argument 3244 // (8.3.6). For the purposes of overload resolution, the 3245 // parameter list is truncated on the right, so that there are 3246 // exactly m parameters. 3247 unsigned MinRequiredArgs = Method->getMinRequiredArguments(); 3248 if (NumArgs < MinRequiredArgs) { 3249 // Not enough arguments. 3250 Candidate.Viable = false; 3251 Candidate.FailureKind = ovl_fail_too_few_arguments; 3252 return; 3253 } 3254 3255 Candidate.Viable = true; 3256 Candidate.Conversions.resize(NumArgs + 1); 3257 3258 if (Method->isStatic() || ObjectType.isNull()) 3259 // The implicit object argument is ignored. 3260 Candidate.IgnoreObjectArgument = true; 3261 else { 3262 // Determine the implicit conversion sequence for the object 3263 // parameter. 3264 Candidate.Conversions[0] 3265 = TryObjectArgumentInitialization(ObjectType, Method, ActingContext); 3266 if (Candidate.Conversions[0].isBad()) { 3267 Candidate.Viable = false; 3268 Candidate.FailureKind = ovl_fail_bad_conversion; 3269 return; 3270 } 3271 } 3272 3273 // Determine the implicit conversion sequences for each of the 3274 // arguments. 3275 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 3276 if (ArgIdx < NumArgsInProto) { 3277 // (C++ 13.3.2p3): for F to be a viable function, there shall 3278 // exist for each argument an implicit conversion sequence 3279 // (13.3.3.1) that converts that argument to the corresponding 3280 // parameter of F. 3281 QualType ParamType = Proto->getArgType(ArgIdx); 3282 Candidate.Conversions[ArgIdx + 1] 3283 = TryCopyInitialization(*this, Args[ArgIdx], ParamType, 3284 SuppressUserConversions, 3285 /*InOverloadResolution=*/true); 3286 if (Candidate.Conversions[ArgIdx + 1].isBad()) { 3287 Candidate.Viable = false; 3288 Candidate.FailureKind = ovl_fail_bad_conversion; 3289 break; 3290 } 3291 } else { 3292 // (C++ 13.3.2p2): For the purposes of overload resolution, any 3293 // argument for which there is no corresponding parameter is 3294 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 3295 Candidate.Conversions[ArgIdx + 1].setEllipsis(); 3296 } 3297 } 3298} 3299 3300/// \brief Add a C++ member function template as a candidate to the candidate 3301/// set, using template argument deduction to produce an appropriate member 3302/// function template specialization. 3303void 3304Sema::AddMethodTemplateCandidate(FunctionTemplateDecl *MethodTmpl, 3305 DeclAccessPair FoundDecl, 3306 CXXRecordDecl *ActingContext, 3307 const TemplateArgumentListInfo *ExplicitTemplateArgs, 3308 QualType ObjectType, 3309 Expr **Args, unsigned NumArgs, 3310 OverloadCandidateSet& CandidateSet, 3311 bool SuppressUserConversions) { 3312 if (!CandidateSet.isNewCandidate(MethodTmpl)) 3313 return; 3314 3315 // C++ [over.match.funcs]p7: 3316 // In each case where a candidate is a function template, candidate 3317 // function template specializations are generated using template argument 3318 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 3319 // candidate functions in the usual way.113) A given name can refer to one 3320 // or more function templates and also to a set of overloaded non-template 3321 // functions. In such a case, the candidate functions generated from each 3322 // function template are combined with the set of non-template candidate 3323 // functions. 3324 TemplateDeductionInfo Info(Context, CandidateSet.getLocation()); 3325 FunctionDecl *Specialization = 0; 3326 if (TemplateDeductionResult Result 3327 = DeduceTemplateArguments(MethodTmpl, ExplicitTemplateArgs, 3328 Args, NumArgs, Specialization, Info)) { 3329 CandidateSet.push_back(OverloadCandidate()); 3330 OverloadCandidate &Candidate = CandidateSet.back(); 3331 Candidate.FoundDecl = FoundDecl; 3332 Candidate.Function = MethodTmpl->getTemplatedDecl(); 3333 Candidate.Viable = false; 3334 Candidate.FailureKind = ovl_fail_bad_deduction; 3335 Candidate.IsSurrogate = false; 3336 Candidate.IgnoreObjectArgument = false; 3337 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result, 3338 Info); 3339 return; 3340 } 3341 3342 // Add the function template specialization produced by template argument 3343 // deduction as a candidate. 3344 assert(Specialization && "Missing member function template specialization?"); 3345 assert(isa<CXXMethodDecl>(Specialization) && 3346 "Specialization is not a member function?"); 3347 AddMethodCandidate(cast<CXXMethodDecl>(Specialization), FoundDecl, 3348 ActingContext, ObjectType, Args, NumArgs, 3349 CandidateSet, SuppressUserConversions); 3350} 3351 3352/// \brief Add a C++ function template specialization as a candidate 3353/// in the candidate set, using template argument deduction to produce 3354/// an appropriate function template specialization. 3355void 3356Sema::AddTemplateOverloadCandidate(FunctionTemplateDecl *FunctionTemplate, 3357 DeclAccessPair FoundDecl, 3358 const TemplateArgumentListInfo *ExplicitTemplateArgs, 3359 Expr **Args, unsigned NumArgs, 3360 OverloadCandidateSet& CandidateSet, 3361 bool SuppressUserConversions) { 3362 if (!CandidateSet.isNewCandidate(FunctionTemplate)) 3363 return; 3364 3365 // C++ [over.match.funcs]p7: 3366 // In each case where a candidate is a function template, candidate 3367 // function template specializations are generated using template argument 3368 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 3369 // candidate functions in the usual way.113) A given name can refer to one 3370 // or more function templates and also to a set of overloaded non-template 3371 // functions. In such a case, the candidate functions generated from each 3372 // function template are combined with the set of non-template candidate 3373 // functions. 3374 TemplateDeductionInfo Info(Context, CandidateSet.getLocation()); 3375 FunctionDecl *Specialization = 0; 3376 if (TemplateDeductionResult Result 3377 = DeduceTemplateArguments(FunctionTemplate, ExplicitTemplateArgs, 3378 Args, NumArgs, Specialization, Info)) { 3379 CandidateSet.push_back(OverloadCandidate()); 3380 OverloadCandidate &Candidate = CandidateSet.back(); 3381 Candidate.FoundDecl = FoundDecl; 3382 Candidate.Function = FunctionTemplate->getTemplatedDecl(); 3383 Candidate.Viable = false; 3384 Candidate.FailureKind = ovl_fail_bad_deduction; 3385 Candidate.IsSurrogate = false; 3386 Candidate.IgnoreObjectArgument = false; 3387 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result, 3388 Info); 3389 return; 3390 } 3391 3392 // Add the function template specialization produced by template argument 3393 // deduction as a candidate. 3394 assert(Specialization && "Missing function template specialization?"); 3395 AddOverloadCandidate(Specialization, FoundDecl, Args, NumArgs, CandidateSet, 3396 SuppressUserConversions); 3397} 3398 3399/// AddConversionCandidate - Add a C++ conversion function as a 3400/// candidate in the candidate set (C++ [over.match.conv], 3401/// C++ [over.match.copy]). From is the expression we're converting from, 3402/// and ToType is the type that we're eventually trying to convert to 3403/// (which may or may not be the same type as the type that the 3404/// conversion function produces). 3405void 3406Sema::AddConversionCandidate(CXXConversionDecl *Conversion, 3407 DeclAccessPair FoundDecl, 3408 CXXRecordDecl *ActingContext, 3409 Expr *From, QualType ToType, 3410 OverloadCandidateSet& CandidateSet) { 3411 assert(!Conversion->getDescribedFunctionTemplate() && 3412 "Conversion function templates use AddTemplateConversionCandidate"); 3413 QualType ConvType = Conversion->getConversionType().getNonReferenceType(); 3414 if (!CandidateSet.isNewCandidate(Conversion)) 3415 return; 3416 3417 // Overload resolution is always an unevaluated context. 3418 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 3419 3420 // Add this candidate 3421 CandidateSet.push_back(OverloadCandidate()); 3422 OverloadCandidate& Candidate = CandidateSet.back(); 3423 Candidate.FoundDecl = FoundDecl; 3424 Candidate.Function = Conversion; 3425 Candidate.IsSurrogate = false; 3426 Candidate.IgnoreObjectArgument = false; 3427 Candidate.FinalConversion.setAsIdentityConversion(); 3428 Candidate.FinalConversion.setFromType(ConvType); 3429 Candidate.FinalConversion.setAllToTypes(ToType); 3430 3431 // Determine the implicit conversion sequence for the implicit 3432 // object parameter. 3433 Candidate.Viable = true; 3434 Candidate.Conversions.resize(1); 3435 Candidate.Conversions[0] 3436 = TryObjectArgumentInitialization(From->getType(), Conversion, 3437 ActingContext); 3438 // Conversion functions to a different type in the base class is visible in 3439 // the derived class. So, a derived to base conversion should not participate 3440 // in overload resolution. 3441 if (Candidate.Conversions[0].Standard.Second == ICK_Derived_To_Base) 3442 Candidate.Conversions[0].Standard.Second = ICK_Identity; 3443 if (Candidate.Conversions[0].isBad()) { 3444 Candidate.Viable = false; 3445 Candidate.FailureKind = ovl_fail_bad_conversion; 3446 return; 3447 } 3448 3449 // We won't go through a user-define type conversion function to convert a 3450 // derived to base as such conversions are given Conversion Rank. They only 3451 // go through a copy constructor. 13.3.3.1.2-p4 [over.ics.user] 3452 QualType FromCanon 3453 = Context.getCanonicalType(From->getType().getUnqualifiedType()); 3454 QualType ToCanon = Context.getCanonicalType(ToType).getUnqualifiedType(); 3455 if (FromCanon == ToCanon || IsDerivedFrom(FromCanon, ToCanon)) { 3456 Candidate.Viable = false; 3457 Candidate.FailureKind = ovl_fail_trivial_conversion; 3458 return; 3459 } 3460 3461 // To determine what the conversion from the result of calling the 3462 // conversion function to the type we're eventually trying to 3463 // convert to (ToType), we need to synthesize a call to the 3464 // conversion function and attempt copy initialization from it. This 3465 // makes sure that we get the right semantics with respect to 3466 // lvalues/rvalues and the type. Fortunately, we can allocate this 3467 // call on the stack and we don't need its arguments to be 3468 // well-formed. 3469 DeclRefExpr ConversionRef(Conversion, Conversion->getType(), 3470 From->getLocStart()); 3471 ImplicitCastExpr ConversionFn(Context.getPointerType(Conversion->getType()), 3472 CastExpr::CK_FunctionToPointerDecay, 3473 &ConversionRef, CXXBaseSpecifierArray(), false); 3474 3475 // Note that it is safe to allocate CallExpr on the stack here because 3476 // there are 0 arguments (i.e., nothing is allocated using ASTContext's 3477 // allocator). 3478 CallExpr Call(Context, &ConversionFn, 0, 0, 3479 Conversion->getConversionType().getNonReferenceType(), 3480 From->getLocStart()); 3481 ImplicitConversionSequence ICS = 3482 TryCopyInitialization(*this, &Call, ToType, 3483 /*SuppressUserConversions=*/true, 3484 /*InOverloadResolution=*/false); 3485 3486 switch (ICS.getKind()) { 3487 case ImplicitConversionSequence::StandardConversion: 3488 Candidate.FinalConversion = ICS.Standard; 3489 3490 // C++ [over.ics.user]p3: 3491 // If the user-defined conversion is specified by a specialization of a 3492 // conversion function template, the second standard conversion sequence 3493 // shall have exact match rank. 3494 if (Conversion->getPrimaryTemplate() && 3495 GetConversionRank(ICS.Standard.Second) != ICR_Exact_Match) { 3496 Candidate.Viable = false; 3497 Candidate.FailureKind = ovl_fail_final_conversion_not_exact; 3498 } 3499 3500 break; 3501 3502 case ImplicitConversionSequence::BadConversion: 3503 Candidate.Viable = false; 3504 Candidate.FailureKind = ovl_fail_bad_final_conversion; 3505 break; 3506 3507 default: 3508 assert(false && 3509 "Can only end up with a standard conversion sequence or failure"); 3510 } 3511} 3512 3513/// \brief Adds a conversion function template specialization 3514/// candidate to the overload set, using template argument deduction 3515/// to deduce the template arguments of the conversion function 3516/// template from the type that we are converting to (C++ 3517/// [temp.deduct.conv]). 3518void 3519Sema::AddTemplateConversionCandidate(FunctionTemplateDecl *FunctionTemplate, 3520 DeclAccessPair FoundDecl, 3521 CXXRecordDecl *ActingDC, 3522 Expr *From, QualType ToType, 3523 OverloadCandidateSet &CandidateSet) { 3524 assert(isa<CXXConversionDecl>(FunctionTemplate->getTemplatedDecl()) && 3525 "Only conversion function templates permitted here"); 3526 3527 if (!CandidateSet.isNewCandidate(FunctionTemplate)) 3528 return; 3529 3530 TemplateDeductionInfo Info(Context, CandidateSet.getLocation()); 3531 CXXConversionDecl *Specialization = 0; 3532 if (TemplateDeductionResult Result 3533 = DeduceTemplateArguments(FunctionTemplate, ToType, 3534 Specialization, Info)) { 3535 CandidateSet.push_back(OverloadCandidate()); 3536 OverloadCandidate &Candidate = CandidateSet.back(); 3537 Candidate.FoundDecl = FoundDecl; 3538 Candidate.Function = FunctionTemplate->getTemplatedDecl(); 3539 Candidate.Viable = false; 3540 Candidate.FailureKind = ovl_fail_bad_deduction; 3541 Candidate.IsSurrogate = false; 3542 Candidate.IgnoreObjectArgument = false; 3543 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result, 3544 Info); 3545 return; 3546 } 3547 3548 // Add the conversion function template specialization produced by 3549 // template argument deduction as a candidate. 3550 assert(Specialization && "Missing function template specialization?"); 3551 AddConversionCandidate(Specialization, FoundDecl, ActingDC, From, ToType, 3552 CandidateSet); 3553} 3554 3555/// AddSurrogateCandidate - Adds a "surrogate" candidate function that 3556/// converts the given @c Object to a function pointer via the 3557/// conversion function @c Conversion, and then attempts to call it 3558/// with the given arguments (C++ [over.call.object]p2-4). Proto is 3559/// the type of function that we'll eventually be calling. 3560void Sema::AddSurrogateCandidate(CXXConversionDecl *Conversion, 3561 DeclAccessPair FoundDecl, 3562 CXXRecordDecl *ActingContext, 3563 const FunctionProtoType *Proto, 3564 QualType ObjectType, 3565 Expr **Args, unsigned NumArgs, 3566 OverloadCandidateSet& CandidateSet) { 3567 if (!CandidateSet.isNewCandidate(Conversion)) 3568 return; 3569 3570 // Overload resolution is always an unevaluated context. 3571 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 3572 3573 CandidateSet.push_back(OverloadCandidate()); 3574 OverloadCandidate& Candidate = CandidateSet.back(); 3575 Candidate.FoundDecl = FoundDecl; 3576 Candidate.Function = 0; 3577 Candidate.Surrogate = Conversion; 3578 Candidate.Viable = true; 3579 Candidate.IsSurrogate = true; 3580 Candidate.IgnoreObjectArgument = false; 3581 Candidate.Conversions.resize(NumArgs + 1); 3582 3583 // Determine the implicit conversion sequence for the implicit 3584 // object parameter. 3585 ImplicitConversionSequence ObjectInit 3586 = TryObjectArgumentInitialization(ObjectType, Conversion, ActingContext); 3587 if (ObjectInit.isBad()) { 3588 Candidate.Viable = false; 3589 Candidate.FailureKind = ovl_fail_bad_conversion; 3590 Candidate.Conversions[0] = ObjectInit; 3591 return; 3592 } 3593 3594 // The first conversion is actually a user-defined conversion whose 3595 // first conversion is ObjectInit's standard conversion (which is 3596 // effectively a reference binding). Record it as such. 3597 Candidate.Conversions[0].setUserDefined(); 3598 Candidate.Conversions[0].UserDefined.Before = ObjectInit.Standard; 3599 Candidate.Conversions[0].UserDefined.EllipsisConversion = false; 3600 Candidate.Conversions[0].UserDefined.ConversionFunction = Conversion; 3601 Candidate.Conversions[0].UserDefined.After 3602 = Candidate.Conversions[0].UserDefined.Before; 3603 Candidate.Conversions[0].UserDefined.After.setAsIdentityConversion(); 3604 3605 // Find the 3606 unsigned NumArgsInProto = Proto->getNumArgs(); 3607 3608 // (C++ 13.3.2p2): A candidate function having fewer than m 3609 // parameters is viable only if it has an ellipsis in its parameter 3610 // list (8.3.5). 3611 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 3612 Candidate.Viable = false; 3613 Candidate.FailureKind = ovl_fail_too_many_arguments; 3614 return; 3615 } 3616 3617 // Function types don't have any default arguments, so just check if 3618 // we have enough arguments. 3619 if (NumArgs < NumArgsInProto) { 3620 // Not enough arguments. 3621 Candidate.Viable = false; 3622 Candidate.FailureKind = ovl_fail_too_few_arguments; 3623 return; 3624 } 3625 3626 // Determine the implicit conversion sequences for each of the 3627 // arguments. 3628 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 3629 if (ArgIdx < NumArgsInProto) { 3630 // (C++ 13.3.2p3): for F to be a viable function, there shall 3631 // exist for each argument an implicit conversion sequence 3632 // (13.3.3.1) that converts that argument to the corresponding 3633 // parameter of F. 3634 QualType ParamType = Proto->getArgType(ArgIdx); 3635 Candidate.Conversions[ArgIdx + 1] 3636 = TryCopyInitialization(*this, Args[ArgIdx], ParamType, 3637 /*SuppressUserConversions=*/false, 3638 /*InOverloadResolution=*/false); 3639 if (Candidate.Conversions[ArgIdx + 1].isBad()) { 3640 Candidate.Viable = false; 3641 Candidate.FailureKind = ovl_fail_bad_conversion; 3642 break; 3643 } 3644 } else { 3645 // (C++ 13.3.2p2): For the purposes of overload resolution, any 3646 // argument for which there is no corresponding parameter is 3647 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 3648 Candidate.Conversions[ArgIdx + 1].setEllipsis(); 3649 } 3650 } 3651} 3652 3653/// \brief Add overload candidates for overloaded operators that are 3654/// member functions. 3655/// 3656/// Add the overloaded operator candidates that are member functions 3657/// for the operator Op that was used in an operator expression such 3658/// as "x Op y". , Args/NumArgs provides the operator arguments, and 3659/// CandidateSet will store the added overload candidates. (C++ 3660/// [over.match.oper]). 3661void Sema::AddMemberOperatorCandidates(OverloadedOperatorKind Op, 3662 SourceLocation OpLoc, 3663 Expr **Args, unsigned NumArgs, 3664 OverloadCandidateSet& CandidateSet, 3665 SourceRange OpRange) { 3666 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 3667 3668 // C++ [over.match.oper]p3: 3669 // For a unary operator @ with an operand of a type whose 3670 // cv-unqualified version is T1, and for a binary operator @ with 3671 // a left operand of a type whose cv-unqualified version is T1 and 3672 // a right operand of a type whose cv-unqualified version is T2, 3673 // three sets of candidate functions, designated member 3674 // candidates, non-member candidates and built-in candidates, are 3675 // constructed as follows: 3676 QualType T1 = Args[0]->getType(); 3677 QualType T2; 3678 if (NumArgs > 1) 3679 T2 = Args[1]->getType(); 3680 3681 // -- If T1 is a class type, the set of member candidates is the 3682 // result of the qualified lookup of T1::operator@ 3683 // (13.3.1.1.1); otherwise, the set of member candidates is 3684 // empty. 3685 if (const RecordType *T1Rec = T1->getAs<RecordType>()) { 3686 // Complete the type if it can be completed. Otherwise, we're done. 3687 if (RequireCompleteType(OpLoc, T1, PDiag())) 3688 return; 3689 3690 LookupResult Operators(*this, OpName, OpLoc, LookupOrdinaryName); 3691 LookupQualifiedName(Operators, T1Rec->getDecl()); 3692 Operators.suppressDiagnostics(); 3693 3694 for (LookupResult::iterator Oper = Operators.begin(), 3695 OperEnd = Operators.end(); 3696 Oper != OperEnd; 3697 ++Oper) 3698 AddMethodCandidate(Oper.getPair(), Args[0]->getType(), 3699 Args + 1, NumArgs - 1, CandidateSet, 3700 /* SuppressUserConversions = */ false); 3701 } 3702} 3703 3704/// AddBuiltinCandidate - Add a candidate for a built-in 3705/// operator. ResultTy and ParamTys are the result and parameter types 3706/// of the built-in candidate, respectively. Args and NumArgs are the 3707/// arguments being passed to the candidate. IsAssignmentOperator 3708/// should be true when this built-in candidate is an assignment 3709/// operator. NumContextualBoolArguments is the number of arguments 3710/// (at the beginning of the argument list) that will be contextually 3711/// converted to bool. 3712void Sema::AddBuiltinCandidate(QualType ResultTy, QualType *ParamTys, 3713 Expr **Args, unsigned NumArgs, 3714 OverloadCandidateSet& CandidateSet, 3715 bool IsAssignmentOperator, 3716 unsigned NumContextualBoolArguments) { 3717 // Overload resolution is always an unevaluated context. 3718 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 3719 3720 // Add this candidate 3721 CandidateSet.push_back(OverloadCandidate()); 3722 OverloadCandidate& Candidate = CandidateSet.back(); 3723 Candidate.FoundDecl = DeclAccessPair::make(0, AS_none); 3724 Candidate.Function = 0; 3725 Candidate.IsSurrogate = false; 3726 Candidate.IgnoreObjectArgument = false; 3727 Candidate.BuiltinTypes.ResultTy = ResultTy; 3728 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 3729 Candidate.BuiltinTypes.ParamTypes[ArgIdx] = ParamTys[ArgIdx]; 3730 3731 // Determine the implicit conversion sequences for each of the 3732 // arguments. 3733 Candidate.Viable = true; 3734 Candidate.Conversions.resize(NumArgs); 3735 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 3736 // C++ [over.match.oper]p4: 3737 // For the built-in assignment operators, conversions of the 3738 // left operand are restricted as follows: 3739 // -- no temporaries are introduced to hold the left operand, and 3740 // -- no user-defined conversions are applied to the left 3741 // operand to achieve a type match with the left-most 3742 // parameter of a built-in candidate. 3743 // 3744 // We block these conversions by turning off user-defined 3745 // conversions, since that is the only way that initialization of 3746 // a reference to a non-class type can occur from something that 3747 // is not of the same type. 3748 if (ArgIdx < NumContextualBoolArguments) { 3749 assert(ParamTys[ArgIdx] == Context.BoolTy && 3750 "Contextual conversion to bool requires bool type"); 3751 Candidate.Conversions[ArgIdx] = TryContextuallyConvertToBool(Args[ArgIdx]); 3752 } else { 3753 Candidate.Conversions[ArgIdx] 3754 = TryCopyInitialization(*this, Args[ArgIdx], ParamTys[ArgIdx], 3755 ArgIdx == 0 && IsAssignmentOperator, 3756 /*InOverloadResolution=*/false); 3757 } 3758 if (Candidate.Conversions[ArgIdx].isBad()) { 3759 Candidate.Viable = false; 3760 Candidate.FailureKind = ovl_fail_bad_conversion; 3761 break; 3762 } 3763 } 3764} 3765 3766/// BuiltinCandidateTypeSet - A set of types that will be used for the 3767/// candidate operator functions for built-in operators (C++ 3768/// [over.built]). The types are separated into pointer types and 3769/// enumeration types. 3770class BuiltinCandidateTypeSet { 3771 /// TypeSet - A set of types. 3772 typedef llvm::SmallPtrSet<QualType, 8> TypeSet; 3773 3774 /// PointerTypes - The set of pointer types that will be used in the 3775 /// built-in candidates. 3776 TypeSet PointerTypes; 3777 3778 /// MemberPointerTypes - The set of member pointer types that will be 3779 /// used in the built-in candidates. 3780 TypeSet MemberPointerTypes; 3781 3782 /// EnumerationTypes - The set of enumeration types that will be 3783 /// used in the built-in candidates. 3784 TypeSet EnumerationTypes; 3785 3786 /// \brief The set of vector types that will be used in the built-in 3787 /// candidates. 3788 TypeSet VectorTypes; 3789 3790 /// Sema - The semantic analysis instance where we are building the 3791 /// candidate type set. 3792 Sema &SemaRef; 3793 3794 /// Context - The AST context in which we will build the type sets. 3795 ASTContext &Context; 3796 3797 bool AddPointerWithMoreQualifiedTypeVariants(QualType Ty, 3798 const Qualifiers &VisibleQuals); 3799 bool AddMemberPointerWithMoreQualifiedTypeVariants(QualType Ty); 3800 3801public: 3802 /// iterator - Iterates through the types that are part of the set. 3803 typedef TypeSet::iterator iterator; 3804 3805 BuiltinCandidateTypeSet(Sema &SemaRef) 3806 : SemaRef(SemaRef), Context(SemaRef.Context) { } 3807 3808 void AddTypesConvertedFrom(QualType Ty, 3809 SourceLocation Loc, 3810 bool AllowUserConversions, 3811 bool AllowExplicitConversions, 3812 const Qualifiers &VisibleTypeConversionsQuals); 3813 3814 /// pointer_begin - First pointer type found; 3815 iterator pointer_begin() { return PointerTypes.begin(); } 3816 3817 /// pointer_end - Past the last pointer type found; 3818 iterator pointer_end() { return PointerTypes.end(); } 3819 3820 /// member_pointer_begin - First member pointer type found; 3821 iterator member_pointer_begin() { return MemberPointerTypes.begin(); } 3822 3823 /// member_pointer_end - Past the last member pointer type found; 3824 iterator member_pointer_end() { return MemberPointerTypes.end(); } 3825 3826 /// enumeration_begin - First enumeration type found; 3827 iterator enumeration_begin() { return EnumerationTypes.begin(); } 3828 3829 /// enumeration_end - Past the last enumeration type found; 3830 iterator enumeration_end() { return EnumerationTypes.end(); } 3831 3832 iterator vector_begin() { return VectorTypes.begin(); } 3833 iterator vector_end() { return VectorTypes.end(); } 3834}; 3835 3836/// AddPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty to 3837/// the set of pointer types along with any more-qualified variants of 3838/// that type. For example, if @p Ty is "int const *", this routine 3839/// will add "int const *", "int const volatile *", "int const 3840/// restrict *", and "int const volatile restrict *" to the set of 3841/// pointer types. Returns true if the add of @p Ty itself succeeded, 3842/// false otherwise. 3843/// 3844/// FIXME: what to do about extended qualifiers? 3845bool 3846BuiltinCandidateTypeSet::AddPointerWithMoreQualifiedTypeVariants(QualType Ty, 3847 const Qualifiers &VisibleQuals) { 3848 3849 // Insert this type. 3850 if (!PointerTypes.insert(Ty)) 3851 return false; 3852 3853 const PointerType *PointerTy = Ty->getAs<PointerType>(); 3854 assert(PointerTy && "type was not a pointer type!"); 3855 3856 QualType PointeeTy = PointerTy->getPointeeType(); 3857 // Don't add qualified variants of arrays. For one, they're not allowed 3858 // (the qualifier would sink to the element type), and for another, the 3859 // only overload situation where it matters is subscript or pointer +- int, 3860 // and those shouldn't have qualifier variants anyway. 3861 if (PointeeTy->isArrayType()) 3862 return true; 3863 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 3864 if (const ConstantArrayType *Array =Context.getAsConstantArrayType(PointeeTy)) 3865 BaseCVR = Array->getElementType().getCVRQualifiers(); 3866 bool hasVolatile = VisibleQuals.hasVolatile(); 3867 bool hasRestrict = VisibleQuals.hasRestrict(); 3868 3869 // Iterate through all strict supersets of BaseCVR. 3870 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 3871 if ((CVR | BaseCVR) != CVR) continue; 3872 // Skip over Volatile/Restrict if no Volatile/Restrict found anywhere 3873 // in the types. 3874 if ((CVR & Qualifiers::Volatile) && !hasVolatile) continue; 3875 if ((CVR & Qualifiers::Restrict) && !hasRestrict) continue; 3876 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 3877 PointerTypes.insert(Context.getPointerType(QPointeeTy)); 3878 } 3879 3880 return true; 3881} 3882 3883/// AddMemberPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty 3884/// to the set of pointer types along with any more-qualified variants of 3885/// that type. For example, if @p Ty is "int const *", this routine 3886/// will add "int const *", "int const volatile *", "int const 3887/// restrict *", and "int const volatile restrict *" to the set of 3888/// pointer types. Returns true if the add of @p Ty itself succeeded, 3889/// false otherwise. 3890/// 3891/// FIXME: what to do about extended qualifiers? 3892bool 3893BuiltinCandidateTypeSet::AddMemberPointerWithMoreQualifiedTypeVariants( 3894 QualType Ty) { 3895 // Insert this type. 3896 if (!MemberPointerTypes.insert(Ty)) 3897 return false; 3898 3899 const MemberPointerType *PointerTy = Ty->getAs<MemberPointerType>(); 3900 assert(PointerTy && "type was not a member pointer type!"); 3901 3902 QualType PointeeTy = PointerTy->getPointeeType(); 3903 // Don't add qualified variants of arrays. For one, they're not allowed 3904 // (the qualifier would sink to the element type), and for another, the 3905 // only overload situation where it matters is subscript or pointer +- int, 3906 // and those shouldn't have qualifier variants anyway. 3907 if (PointeeTy->isArrayType()) 3908 return true; 3909 const Type *ClassTy = PointerTy->getClass(); 3910 3911 // Iterate through all strict supersets of the pointee type's CVR 3912 // qualifiers. 3913 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 3914 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 3915 if ((CVR | BaseCVR) != CVR) continue; 3916 3917 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 3918 MemberPointerTypes.insert(Context.getMemberPointerType(QPointeeTy, ClassTy)); 3919 } 3920 3921 return true; 3922} 3923 3924/// AddTypesConvertedFrom - Add each of the types to which the type @p 3925/// Ty can be implicit converted to the given set of @p Types. We're 3926/// primarily interested in pointer types and enumeration types. We also 3927/// take member pointer types, for the conditional operator. 3928/// AllowUserConversions is true if we should look at the conversion 3929/// functions of a class type, and AllowExplicitConversions if we 3930/// should also include the explicit conversion functions of a class 3931/// type. 3932void 3933BuiltinCandidateTypeSet::AddTypesConvertedFrom(QualType Ty, 3934 SourceLocation Loc, 3935 bool AllowUserConversions, 3936 bool AllowExplicitConversions, 3937 const Qualifiers &VisibleQuals) { 3938 // Only deal with canonical types. 3939 Ty = Context.getCanonicalType(Ty); 3940 3941 // Look through reference types; they aren't part of the type of an 3942 // expression for the purposes of conversions. 3943 if (const ReferenceType *RefTy = Ty->getAs<ReferenceType>()) 3944 Ty = RefTy->getPointeeType(); 3945 3946 // We don't care about qualifiers on the type. 3947 Ty = Ty.getLocalUnqualifiedType(); 3948 3949 // If we're dealing with an array type, decay to the pointer. 3950 if (Ty->isArrayType()) 3951 Ty = SemaRef.Context.getArrayDecayedType(Ty); 3952 3953 if (const PointerType *PointerTy = Ty->getAs<PointerType>()) { 3954 QualType PointeeTy = PointerTy->getPointeeType(); 3955 3956 // Insert our type, and its more-qualified variants, into the set 3957 // of types. 3958 if (!AddPointerWithMoreQualifiedTypeVariants(Ty, VisibleQuals)) 3959 return; 3960 } else if (Ty->isMemberPointerType()) { 3961 // Member pointers are far easier, since the pointee can't be converted. 3962 if (!AddMemberPointerWithMoreQualifiedTypeVariants(Ty)) 3963 return; 3964 } else if (Ty->isEnumeralType()) { 3965 EnumerationTypes.insert(Ty); 3966 } else if (Ty->isVectorType()) { 3967 VectorTypes.insert(Ty); 3968 } else if (AllowUserConversions) { 3969 if (const RecordType *TyRec = Ty->getAs<RecordType>()) { 3970 if (SemaRef.RequireCompleteType(Loc, Ty, 0)) { 3971 // No conversion functions in incomplete types. 3972 return; 3973 } 3974 3975 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 3976 const UnresolvedSetImpl *Conversions 3977 = ClassDecl->getVisibleConversionFunctions(); 3978 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 3979 E = Conversions->end(); I != E; ++I) { 3980 NamedDecl *D = I.getDecl(); 3981 if (isa<UsingShadowDecl>(D)) 3982 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 3983 3984 // Skip conversion function templates; they don't tell us anything 3985 // about which builtin types we can convert to. 3986 if (isa<FunctionTemplateDecl>(D)) 3987 continue; 3988 3989 CXXConversionDecl *Conv = cast<CXXConversionDecl>(D); 3990 if (AllowExplicitConversions || !Conv->isExplicit()) { 3991 AddTypesConvertedFrom(Conv->getConversionType(), Loc, false, false, 3992 VisibleQuals); 3993 } 3994 } 3995 } 3996 } 3997} 3998 3999/// \brief Helper function for AddBuiltinOperatorCandidates() that adds 4000/// the volatile- and non-volatile-qualified assignment operators for the 4001/// given type to the candidate set. 4002static void AddBuiltinAssignmentOperatorCandidates(Sema &S, 4003 QualType T, 4004 Expr **Args, 4005 unsigned NumArgs, 4006 OverloadCandidateSet &CandidateSet) { 4007 QualType ParamTypes[2]; 4008 4009 // T& operator=(T&, T) 4010 ParamTypes[0] = S.Context.getLValueReferenceType(T); 4011 ParamTypes[1] = T; 4012 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4013 /*IsAssignmentOperator=*/true); 4014 4015 if (!S.Context.getCanonicalType(T).isVolatileQualified()) { 4016 // volatile T& operator=(volatile T&, T) 4017 ParamTypes[0] 4018 = S.Context.getLValueReferenceType(S.Context.getVolatileType(T)); 4019 ParamTypes[1] = T; 4020 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4021 /*IsAssignmentOperator=*/true); 4022 } 4023} 4024 4025/// CollectVRQualifiers - This routine returns Volatile/Restrict qualifiers, 4026/// if any, found in visible type conversion functions found in ArgExpr's type. 4027static Qualifiers CollectVRQualifiers(ASTContext &Context, Expr* ArgExpr) { 4028 Qualifiers VRQuals; 4029 const RecordType *TyRec; 4030 if (const MemberPointerType *RHSMPType = 4031 ArgExpr->getType()->getAs<MemberPointerType>()) 4032 TyRec = RHSMPType->getClass()->getAs<RecordType>(); 4033 else 4034 TyRec = ArgExpr->getType()->getAs<RecordType>(); 4035 if (!TyRec) { 4036 // Just to be safe, assume the worst case. 4037 VRQuals.addVolatile(); 4038 VRQuals.addRestrict(); 4039 return VRQuals; 4040 } 4041 4042 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 4043 if (!ClassDecl->hasDefinition()) 4044 return VRQuals; 4045 4046 const UnresolvedSetImpl *Conversions = 4047 ClassDecl->getVisibleConversionFunctions(); 4048 4049 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 4050 E = Conversions->end(); I != E; ++I) { 4051 NamedDecl *D = I.getDecl(); 4052 if (isa<UsingShadowDecl>(D)) 4053 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 4054 if (CXXConversionDecl *Conv = dyn_cast<CXXConversionDecl>(D)) { 4055 QualType CanTy = Context.getCanonicalType(Conv->getConversionType()); 4056 if (const ReferenceType *ResTypeRef = CanTy->getAs<ReferenceType>()) 4057 CanTy = ResTypeRef->getPointeeType(); 4058 // Need to go down the pointer/mempointer chain and add qualifiers 4059 // as see them. 4060 bool done = false; 4061 while (!done) { 4062 if (const PointerType *ResTypePtr = CanTy->getAs<PointerType>()) 4063 CanTy = ResTypePtr->getPointeeType(); 4064 else if (const MemberPointerType *ResTypeMPtr = 4065 CanTy->getAs<MemberPointerType>()) 4066 CanTy = ResTypeMPtr->getPointeeType(); 4067 else 4068 done = true; 4069 if (CanTy.isVolatileQualified()) 4070 VRQuals.addVolatile(); 4071 if (CanTy.isRestrictQualified()) 4072 VRQuals.addRestrict(); 4073 if (VRQuals.hasRestrict() && VRQuals.hasVolatile()) 4074 return VRQuals; 4075 } 4076 } 4077 } 4078 return VRQuals; 4079} 4080 4081/// AddBuiltinOperatorCandidates - Add the appropriate built-in 4082/// operator overloads to the candidate set (C++ [over.built]), based 4083/// on the operator @p Op and the arguments given. For example, if the 4084/// operator is a binary '+', this routine might add "int 4085/// operator+(int, int)" to cover integer addition. 4086void 4087Sema::AddBuiltinOperatorCandidates(OverloadedOperatorKind Op, 4088 SourceLocation OpLoc, 4089 Expr **Args, unsigned NumArgs, 4090 OverloadCandidateSet& CandidateSet) { 4091 // The set of "promoted arithmetic types", which are the arithmetic 4092 // types are that preserved by promotion (C++ [over.built]p2). Note 4093 // that the first few of these types are the promoted integral 4094 // types; these types need to be first. 4095 // FIXME: What about complex? 4096 const unsigned FirstIntegralType = 0; 4097 const unsigned LastIntegralType = 13; 4098 const unsigned FirstPromotedIntegralType = 7, 4099 LastPromotedIntegralType = 13; 4100 const unsigned FirstPromotedArithmeticType = 7, 4101 LastPromotedArithmeticType = 16; 4102 const unsigned NumArithmeticTypes = 16; 4103 QualType ArithmeticTypes[NumArithmeticTypes] = { 4104 Context.BoolTy, Context.CharTy, Context.WCharTy, 4105// FIXME: Context.Char16Ty, Context.Char32Ty, 4106 Context.SignedCharTy, Context.ShortTy, 4107 Context.UnsignedCharTy, Context.UnsignedShortTy, 4108 Context.IntTy, Context.LongTy, Context.LongLongTy, 4109 Context.UnsignedIntTy, Context.UnsignedLongTy, Context.UnsignedLongLongTy, 4110 Context.FloatTy, Context.DoubleTy, Context.LongDoubleTy 4111 }; 4112 assert(ArithmeticTypes[FirstPromotedIntegralType] == Context.IntTy && 4113 "Invalid first promoted integral type"); 4114 assert(ArithmeticTypes[LastPromotedIntegralType - 1] 4115 == Context.UnsignedLongLongTy && 4116 "Invalid last promoted integral type"); 4117 assert(ArithmeticTypes[FirstPromotedArithmeticType] == Context.IntTy && 4118 "Invalid first promoted arithmetic type"); 4119 assert(ArithmeticTypes[LastPromotedArithmeticType - 1] 4120 == Context.LongDoubleTy && 4121 "Invalid last promoted arithmetic type"); 4122 4123 // Find all of the types that the arguments can convert to, but only 4124 // if the operator we're looking at has built-in operator candidates 4125 // that make use of these types. 4126 Qualifiers VisibleTypeConversionsQuals; 4127 VisibleTypeConversionsQuals.addConst(); 4128 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 4129 VisibleTypeConversionsQuals += CollectVRQualifiers(Context, Args[ArgIdx]); 4130 4131 BuiltinCandidateTypeSet CandidateTypes(*this); 4132 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 4133 CandidateTypes.AddTypesConvertedFrom(Args[ArgIdx]->getType(), 4134 OpLoc, 4135 true, 4136 (Op == OO_Exclaim || 4137 Op == OO_AmpAmp || 4138 Op == OO_PipePipe), 4139 VisibleTypeConversionsQuals); 4140 4141 bool isComparison = false; 4142 switch (Op) { 4143 case OO_None: 4144 case NUM_OVERLOADED_OPERATORS: 4145 assert(false && "Expected an overloaded operator"); 4146 break; 4147 4148 case OO_Star: // '*' is either unary or binary 4149 if (NumArgs == 1) 4150 goto UnaryStar; 4151 else 4152 goto BinaryStar; 4153 break; 4154 4155 case OO_Plus: // '+' is either unary or binary 4156 if (NumArgs == 1) 4157 goto UnaryPlus; 4158 else 4159 goto BinaryPlus; 4160 break; 4161 4162 case OO_Minus: // '-' is either unary or binary 4163 if (NumArgs == 1) 4164 goto UnaryMinus; 4165 else 4166 goto BinaryMinus; 4167 break; 4168 4169 case OO_Amp: // '&' is either unary or binary 4170 if (NumArgs == 1) 4171 goto UnaryAmp; 4172 else 4173 goto BinaryAmp; 4174 4175 case OO_PlusPlus: 4176 case OO_MinusMinus: 4177 // C++ [over.built]p3: 4178 // 4179 // For every pair (T, VQ), where T is an arithmetic type, and VQ 4180 // is either volatile or empty, there exist candidate operator 4181 // functions of the form 4182 // 4183 // VQ T& operator++(VQ T&); 4184 // T operator++(VQ T&, int); 4185 // 4186 // C++ [over.built]p4: 4187 // 4188 // For every pair (T, VQ), where T is an arithmetic type other 4189 // than bool, and VQ is either volatile or empty, there exist 4190 // candidate operator functions of the form 4191 // 4192 // VQ T& operator--(VQ T&); 4193 // T operator--(VQ T&, int); 4194 for (unsigned Arith = (Op == OO_PlusPlus? 0 : 1); 4195 Arith < NumArithmeticTypes; ++Arith) { 4196 QualType ArithTy = ArithmeticTypes[Arith]; 4197 QualType ParamTypes[2] 4198 = { Context.getLValueReferenceType(ArithTy), Context.IntTy }; 4199 4200 // Non-volatile version. 4201 if (NumArgs == 1) 4202 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 4203 else 4204 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 4205 // heuristic to reduce number of builtin candidates in the set. 4206 // Add volatile version only if there are conversions to a volatile type. 4207 if (VisibleTypeConversionsQuals.hasVolatile()) { 4208 // Volatile version 4209 ParamTypes[0] 4210 = Context.getLValueReferenceType(Context.getVolatileType(ArithTy)); 4211 if (NumArgs == 1) 4212 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 4213 else 4214 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 4215 } 4216 } 4217 4218 // C++ [over.built]p5: 4219 // 4220 // For every pair (T, VQ), where T is a cv-qualified or 4221 // cv-unqualified object type, and VQ is either volatile or 4222 // empty, there exist candidate operator functions of the form 4223 // 4224 // T*VQ& operator++(T*VQ&); 4225 // T*VQ& operator--(T*VQ&); 4226 // T* operator++(T*VQ&, int); 4227 // T* operator--(T*VQ&, int); 4228 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 4229 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4230 // Skip pointer types that aren't pointers to object types. 4231 if (!(*Ptr)->getAs<PointerType>()->getPointeeType()->isObjectType()) 4232 continue; 4233 4234 QualType ParamTypes[2] = { 4235 Context.getLValueReferenceType(*Ptr), Context.IntTy 4236 }; 4237 4238 // Without volatile 4239 if (NumArgs == 1) 4240 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 4241 else 4242 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 4243 4244 if (!Context.getCanonicalType(*Ptr).isVolatileQualified() && 4245 VisibleTypeConversionsQuals.hasVolatile()) { 4246 // With volatile 4247 ParamTypes[0] 4248 = Context.getLValueReferenceType(Context.getVolatileType(*Ptr)); 4249 if (NumArgs == 1) 4250 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 4251 else 4252 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 4253 } 4254 } 4255 break; 4256 4257 UnaryStar: 4258 // C++ [over.built]p6: 4259 // For every cv-qualified or cv-unqualified object type T, there 4260 // exist candidate operator functions of the form 4261 // 4262 // T& operator*(T*); 4263 // 4264 // C++ [over.built]p7: 4265 // For every function type T, there exist candidate operator 4266 // functions of the form 4267 // T& operator*(T*); 4268 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 4269 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4270 QualType ParamTy = *Ptr; 4271 QualType PointeeTy = ParamTy->getAs<PointerType>()->getPointeeType(); 4272 AddBuiltinCandidate(Context.getLValueReferenceType(PointeeTy), 4273 &ParamTy, Args, 1, CandidateSet); 4274 } 4275 break; 4276 4277 UnaryPlus: 4278 // C++ [over.built]p8: 4279 // For every type T, there exist candidate operator functions of 4280 // the form 4281 // 4282 // T* operator+(T*); 4283 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 4284 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4285 QualType ParamTy = *Ptr; 4286 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet); 4287 } 4288 4289 // Fall through 4290 4291 UnaryMinus: 4292 // C++ [over.built]p9: 4293 // For every promoted arithmetic type T, there exist candidate 4294 // operator functions of the form 4295 // 4296 // T operator+(T); 4297 // T operator-(T); 4298 for (unsigned Arith = FirstPromotedArithmeticType; 4299 Arith < LastPromotedArithmeticType; ++Arith) { 4300 QualType ArithTy = ArithmeticTypes[Arith]; 4301 AddBuiltinCandidate(ArithTy, &ArithTy, Args, 1, CandidateSet); 4302 } 4303 4304 // Extension: We also add these operators for vector types. 4305 for (BuiltinCandidateTypeSet::iterator Vec = CandidateTypes.vector_begin(), 4306 VecEnd = CandidateTypes.vector_end(); 4307 Vec != VecEnd; ++Vec) { 4308 QualType VecTy = *Vec; 4309 AddBuiltinCandidate(VecTy, &VecTy, Args, 1, CandidateSet); 4310 } 4311 break; 4312 4313 case OO_Tilde: 4314 // C++ [over.built]p10: 4315 // For every promoted integral type T, there exist candidate 4316 // operator functions of the form 4317 // 4318 // T operator~(T); 4319 for (unsigned Int = FirstPromotedIntegralType; 4320 Int < LastPromotedIntegralType; ++Int) { 4321 QualType IntTy = ArithmeticTypes[Int]; 4322 AddBuiltinCandidate(IntTy, &IntTy, Args, 1, CandidateSet); 4323 } 4324 4325 // Extension: We also add this operator for vector types. 4326 for (BuiltinCandidateTypeSet::iterator Vec = CandidateTypes.vector_begin(), 4327 VecEnd = CandidateTypes.vector_end(); 4328 Vec != VecEnd; ++Vec) { 4329 QualType VecTy = *Vec; 4330 AddBuiltinCandidate(VecTy, &VecTy, Args, 1, CandidateSet); 4331 } 4332 break; 4333 4334 case OO_New: 4335 case OO_Delete: 4336 case OO_Array_New: 4337 case OO_Array_Delete: 4338 case OO_Call: 4339 assert(false && "Special operators don't use AddBuiltinOperatorCandidates"); 4340 break; 4341 4342 case OO_Comma: 4343 UnaryAmp: 4344 case OO_Arrow: 4345 // C++ [over.match.oper]p3: 4346 // -- For the operator ',', the unary operator '&', or the 4347 // operator '->', the built-in candidates set is empty. 4348 break; 4349 4350 case OO_EqualEqual: 4351 case OO_ExclaimEqual: 4352 // C++ [over.match.oper]p16: 4353 // For every pointer to member type T, there exist candidate operator 4354 // functions of the form 4355 // 4356 // bool operator==(T,T); 4357 // bool operator!=(T,T); 4358 for (BuiltinCandidateTypeSet::iterator 4359 MemPtr = CandidateTypes.member_pointer_begin(), 4360 MemPtrEnd = CandidateTypes.member_pointer_end(); 4361 MemPtr != MemPtrEnd; 4362 ++MemPtr) { 4363 QualType ParamTypes[2] = { *MemPtr, *MemPtr }; 4364 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 4365 } 4366 4367 // Fall through 4368 4369 case OO_Less: 4370 case OO_Greater: 4371 case OO_LessEqual: 4372 case OO_GreaterEqual: 4373 // C++ [over.built]p15: 4374 // 4375 // For every pointer or enumeration type T, there exist 4376 // candidate operator functions of the form 4377 // 4378 // bool operator<(T, T); 4379 // bool operator>(T, T); 4380 // bool operator<=(T, T); 4381 // bool operator>=(T, T); 4382 // bool operator==(T, T); 4383 // bool operator!=(T, T); 4384 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 4385 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4386 QualType ParamTypes[2] = { *Ptr, *Ptr }; 4387 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 4388 } 4389 for (BuiltinCandidateTypeSet::iterator Enum 4390 = CandidateTypes.enumeration_begin(); 4391 Enum != CandidateTypes.enumeration_end(); ++Enum) { 4392 QualType ParamTypes[2] = { *Enum, *Enum }; 4393 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 4394 } 4395 4396 // Fall through. 4397 isComparison = true; 4398 4399 BinaryPlus: 4400 BinaryMinus: 4401 if (!isComparison) { 4402 // We didn't fall through, so we must have OO_Plus or OO_Minus. 4403 4404 // C++ [over.built]p13: 4405 // 4406 // For every cv-qualified or cv-unqualified object type T 4407 // there exist candidate operator functions of the form 4408 // 4409 // T* operator+(T*, ptrdiff_t); 4410 // T& operator[](T*, ptrdiff_t); [BELOW] 4411 // T* operator-(T*, ptrdiff_t); 4412 // T* operator+(ptrdiff_t, T*); 4413 // T& operator[](ptrdiff_t, T*); [BELOW] 4414 // 4415 // C++ [over.built]p14: 4416 // 4417 // For every T, where T is a pointer to object type, there 4418 // exist candidate operator functions of the form 4419 // 4420 // ptrdiff_t operator-(T, T); 4421 for (BuiltinCandidateTypeSet::iterator Ptr 4422 = CandidateTypes.pointer_begin(); 4423 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4424 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 4425 4426 // operator+(T*, ptrdiff_t) or operator-(T*, ptrdiff_t) 4427 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 4428 4429 if (Op == OO_Plus) { 4430 // T* operator+(ptrdiff_t, T*); 4431 ParamTypes[0] = ParamTypes[1]; 4432 ParamTypes[1] = *Ptr; 4433 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 4434 } else { 4435 // ptrdiff_t operator-(T, T); 4436 ParamTypes[1] = *Ptr; 4437 AddBuiltinCandidate(Context.getPointerDiffType(), ParamTypes, 4438 Args, 2, CandidateSet); 4439 } 4440 } 4441 } 4442 // Fall through 4443 4444 case OO_Slash: 4445 BinaryStar: 4446 Conditional: 4447 // C++ [over.built]p12: 4448 // 4449 // For every pair of promoted arithmetic types L and R, there 4450 // exist candidate operator functions of the form 4451 // 4452 // LR operator*(L, R); 4453 // LR operator/(L, R); 4454 // LR operator+(L, R); 4455 // LR operator-(L, R); 4456 // bool operator<(L, R); 4457 // bool operator>(L, R); 4458 // bool operator<=(L, R); 4459 // bool operator>=(L, R); 4460 // bool operator==(L, R); 4461 // bool operator!=(L, R); 4462 // 4463 // where LR is the result of the usual arithmetic conversions 4464 // between types L and R. 4465 // 4466 // C++ [over.built]p24: 4467 // 4468 // For every pair of promoted arithmetic types L and R, there exist 4469 // candidate operator functions of the form 4470 // 4471 // LR operator?(bool, L, R); 4472 // 4473 // where LR is the result of the usual arithmetic conversions 4474 // between types L and R. 4475 // Our candidates ignore the first parameter. 4476 for (unsigned Left = FirstPromotedArithmeticType; 4477 Left < LastPromotedArithmeticType; ++Left) { 4478 for (unsigned Right = FirstPromotedArithmeticType; 4479 Right < LastPromotedArithmeticType; ++Right) { 4480 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 4481 QualType Result 4482 = isComparison 4483 ? Context.BoolTy 4484 : Context.UsualArithmeticConversionsType(LandR[0], LandR[1]); 4485 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 4486 } 4487 } 4488 4489 // Extension: Add the binary operators ==, !=, <, <=, >=, >, *, /, and the 4490 // conditional operator for vector types. 4491 for (BuiltinCandidateTypeSet::iterator Vec1 = CandidateTypes.vector_begin(), 4492 Vec1End = CandidateTypes.vector_end(); 4493 Vec1 != Vec1End; ++Vec1) 4494 for (BuiltinCandidateTypeSet::iterator 4495 Vec2 = CandidateTypes.vector_begin(), 4496 Vec2End = CandidateTypes.vector_end(); 4497 Vec2 != Vec2End; ++Vec2) { 4498 QualType LandR[2] = { *Vec1, *Vec2 }; 4499 QualType Result; 4500 if (isComparison) 4501 Result = Context.BoolTy; 4502 else { 4503 if ((*Vec1)->isExtVectorType() || !(*Vec2)->isExtVectorType()) 4504 Result = *Vec1; 4505 else 4506 Result = *Vec2; 4507 } 4508 4509 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 4510 } 4511 4512 break; 4513 4514 case OO_Percent: 4515 BinaryAmp: 4516 case OO_Caret: 4517 case OO_Pipe: 4518 case OO_LessLess: 4519 case OO_GreaterGreater: 4520 // C++ [over.built]p17: 4521 // 4522 // For every pair of promoted integral types L and R, there 4523 // exist candidate operator functions of the form 4524 // 4525 // LR operator%(L, R); 4526 // LR operator&(L, R); 4527 // LR operator^(L, R); 4528 // LR operator|(L, R); 4529 // L operator<<(L, R); 4530 // L operator>>(L, R); 4531 // 4532 // where LR is the result of the usual arithmetic conversions 4533 // between types L and R. 4534 for (unsigned Left = FirstPromotedIntegralType; 4535 Left < LastPromotedIntegralType; ++Left) { 4536 for (unsigned Right = FirstPromotedIntegralType; 4537 Right < LastPromotedIntegralType; ++Right) { 4538 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 4539 QualType Result = (Op == OO_LessLess || Op == OO_GreaterGreater) 4540 ? LandR[0] 4541 : Context.UsualArithmeticConversionsType(LandR[0], LandR[1]); 4542 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 4543 } 4544 } 4545 break; 4546 4547 case OO_Equal: 4548 // C++ [over.built]p20: 4549 // 4550 // For every pair (T, VQ), where T is an enumeration or 4551 // pointer to member type and VQ is either volatile or 4552 // empty, there exist candidate operator functions of the form 4553 // 4554 // VQ T& operator=(VQ T&, T); 4555 for (BuiltinCandidateTypeSet::iterator 4556 Enum = CandidateTypes.enumeration_begin(), 4557 EnumEnd = CandidateTypes.enumeration_end(); 4558 Enum != EnumEnd; ++Enum) 4559 AddBuiltinAssignmentOperatorCandidates(*this, *Enum, Args, 2, 4560 CandidateSet); 4561 for (BuiltinCandidateTypeSet::iterator 4562 MemPtr = CandidateTypes.member_pointer_begin(), 4563 MemPtrEnd = CandidateTypes.member_pointer_end(); 4564 MemPtr != MemPtrEnd; ++MemPtr) 4565 AddBuiltinAssignmentOperatorCandidates(*this, *MemPtr, Args, 2, 4566 CandidateSet); 4567 4568 // Fall through. 4569 4570 case OO_PlusEqual: 4571 case OO_MinusEqual: 4572 // C++ [over.built]p19: 4573 // 4574 // For every pair (T, VQ), where T is any type and VQ is either 4575 // volatile or empty, there exist candidate operator functions 4576 // of the form 4577 // 4578 // T*VQ& operator=(T*VQ&, T*); 4579 // 4580 // C++ [over.built]p21: 4581 // 4582 // For every pair (T, VQ), where T is a cv-qualified or 4583 // cv-unqualified object type and VQ is either volatile or 4584 // empty, there exist candidate operator functions of the form 4585 // 4586 // T*VQ& operator+=(T*VQ&, ptrdiff_t); 4587 // T*VQ& operator-=(T*VQ&, ptrdiff_t); 4588 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 4589 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4590 QualType ParamTypes[2]; 4591 ParamTypes[1] = (Op == OO_Equal)? *Ptr : Context.getPointerDiffType(); 4592 4593 // non-volatile version 4594 ParamTypes[0] = Context.getLValueReferenceType(*Ptr); 4595 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4596 /*IsAssigmentOperator=*/Op == OO_Equal); 4597 4598 if (!Context.getCanonicalType(*Ptr).isVolatileQualified() && 4599 VisibleTypeConversionsQuals.hasVolatile()) { 4600 // volatile version 4601 ParamTypes[0] 4602 = Context.getLValueReferenceType(Context.getVolatileType(*Ptr)); 4603 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4604 /*IsAssigmentOperator=*/Op == OO_Equal); 4605 } 4606 } 4607 // Fall through. 4608 4609 case OO_StarEqual: 4610 case OO_SlashEqual: 4611 // C++ [over.built]p18: 4612 // 4613 // For every triple (L, VQ, R), where L is an arithmetic type, 4614 // VQ is either volatile or empty, and R is a promoted 4615 // arithmetic type, there exist candidate operator functions of 4616 // the form 4617 // 4618 // VQ L& operator=(VQ L&, R); 4619 // VQ L& operator*=(VQ L&, R); 4620 // VQ L& operator/=(VQ L&, R); 4621 // VQ L& operator+=(VQ L&, R); 4622 // VQ L& operator-=(VQ L&, R); 4623 for (unsigned Left = 0; Left < NumArithmeticTypes; ++Left) { 4624 for (unsigned Right = FirstPromotedArithmeticType; 4625 Right < LastPromotedArithmeticType; ++Right) { 4626 QualType ParamTypes[2]; 4627 ParamTypes[1] = ArithmeticTypes[Right]; 4628 4629 // Add this built-in operator as a candidate (VQ is empty). 4630 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 4631 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4632 /*IsAssigmentOperator=*/Op == OO_Equal); 4633 4634 // Add this built-in operator as a candidate (VQ is 'volatile'). 4635 if (VisibleTypeConversionsQuals.hasVolatile()) { 4636 ParamTypes[0] = Context.getVolatileType(ArithmeticTypes[Left]); 4637 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 4638 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4639 /*IsAssigmentOperator=*/Op == OO_Equal); 4640 } 4641 } 4642 } 4643 4644 // Extension: Add the binary operators =, +=, -=, *=, /= for vector types. 4645 for (BuiltinCandidateTypeSet::iterator Vec1 = CandidateTypes.vector_begin(), 4646 Vec1End = CandidateTypes.vector_end(); 4647 Vec1 != Vec1End; ++Vec1) 4648 for (BuiltinCandidateTypeSet::iterator 4649 Vec2 = CandidateTypes.vector_begin(), 4650 Vec2End = CandidateTypes.vector_end(); 4651 Vec2 != Vec2End; ++Vec2) { 4652 QualType ParamTypes[2]; 4653 ParamTypes[1] = *Vec2; 4654 // Add this built-in operator as a candidate (VQ is empty). 4655 ParamTypes[0] = Context.getLValueReferenceType(*Vec1); 4656 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4657 /*IsAssigmentOperator=*/Op == OO_Equal); 4658 4659 // Add this built-in operator as a candidate (VQ is 'volatile'). 4660 if (VisibleTypeConversionsQuals.hasVolatile()) { 4661 ParamTypes[0] = Context.getVolatileType(*Vec1); 4662 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 4663 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4664 /*IsAssigmentOperator=*/Op == OO_Equal); 4665 } 4666 } 4667 break; 4668 4669 case OO_PercentEqual: 4670 case OO_LessLessEqual: 4671 case OO_GreaterGreaterEqual: 4672 case OO_AmpEqual: 4673 case OO_CaretEqual: 4674 case OO_PipeEqual: 4675 // C++ [over.built]p22: 4676 // 4677 // For every triple (L, VQ, R), where L is an integral type, VQ 4678 // is either volatile or empty, and R is a promoted integral 4679 // type, there exist candidate operator functions of the form 4680 // 4681 // VQ L& operator%=(VQ L&, R); 4682 // VQ L& operator<<=(VQ L&, R); 4683 // VQ L& operator>>=(VQ L&, R); 4684 // VQ L& operator&=(VQ L&, R); 4685 // VQ L& operator^=(VQ L&, R); 4686 // VQ L& operator|=(VQ L&, R); 4687 for (unsigned Left = FirstIntegralType; Left < LastIntegralType; ++Left) { 4688 for (unsigned Right = FirstPromotedIntegralType; 4689 Right < LastPromotedIntegralType; ++Right) { 4690 QualType ParamTypes[2]; 4691 ParamTypes[1] = ArithmeticTypes[Right]; 4692 4693 // Add this built-in operator as a candidate (VQ is empty). 4694 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 4695 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 4696 if (VisibleTypeConversionsQuals.hasVolatile()) { 4697 // Add this built-in operator as a candidate (VQ is 'volatile'). 4698 ParamTypes[0] = ArithmeticTypes[Left]; 4699 ParamTypes[0] = Context.getVolatileType(ParamTypes[0]); 4700 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 4701 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 4702 } 4703 } 4704 } 4705 break; 4706 4707 case OO_Exclaim: { 4708 // C++ [over.operator]p23: 4709 // 4710 // There also exist candidate operator functions of the form 4711 // 4712 // bool operator!(bool); 4713 // bool operator&&(bool, bool); [BELOW] 4714 // bool operator||(bool, bool); [BELOW] 4715 QualType ParamTy = Context.BoolTy; 4716 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet, 4717 /*IsAssignmentOperator=*/false, 4718 /*NumContextualBoolArguments=*/1); 4719 break; 4720 } 4721 4722 case OO_AmpAmp: 4723 case OO_PipePipe: { 4724 // C++ [over.operator]p23: 4725 // 4726 // There also exist candidate operator functions of the form 4727 // 4728 // bool operator!(bool); [ABOVE] 4729 // bool operator&&(bool, bool); 4730 // bool operator||(bool, bool); 4731 QualType ParamTypes[2] = { Context.BoolTy, Context.BoolTy }; 4732 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet, 4733 /*IsAssignmentOperator=*/false, 4734 /*NumContextualBoolArguments=*/2); 4735 break; 4736 } 4737 4738 case OO_Subscript: 4739 // C++ [over.built]p13: 4740 // 4741 // For every cv-qualified or cv-unqualified object type T there 4742 // exist candidate operator functions of the form 4743 // 4744 // T* operator+(T*, ptrdiff_t); [ABOVE] 4745 // T& operator[](T*, ptrdiff_t); 4746 // T* operator-(T*, ptrdiff_t); [ABOVE] 4747 // T* operator+(ptrdiff_t, T*); [ABOVE] 4748 // T& operator[](ptrdiff_t, T*); 4749 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 4750 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4751 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 4752 QualType PointeeType = (*Ptr)->getAs<PointerType>()->getPointeeType(); 4753 QualType ResultTy = Context.getLValueReferenceType(PointeeType); 4754 4755 // T& operator[](T*, ptrdiff_t) 4756 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 4757 4758 // T& operator[](ptrdiff_t, T*); 4759 ParamTypes[0] = ParamTypes[1]; 4760 ParamTypes[1] = *Ptr; 4761 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 4762 } 4763 break; 4764 4765 case OO_ArrowStar: 4766 // C++ [over.built]p11: 4767 // For every quintuple (C1, C2, T, CV1, CV2), where C2 is a class type, 4768 // C1 is the same type as C2 or is a derived class of C2, T is an object 4769 // type or a function type, and CV1 and CV2 are cv-qualifier-seqs, 4770 // there exist candidate operator functions of the form 4771 // CV12 T& operator->*(CV1 C1*, CV2 T C2::*); 4772 // where CV12 is the union of CV1 and CV2. 4773 { 4774 for (BuiltinCandidateTypeSet::iterator Ptr = 4775 CandidateTypes.pointer_begin(); 4776 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4777 QualType C1Ty = (*Ptr); 4778 QualType C1; 4779 QualifierCollector Q1; 4780 if (const PointerType *PointerTy = C1Ty->getAs<PointerType>()) { 4781 C1 = QualType(Q1.strip(PointerTy->getPointeeType()), 0); 4782 if (!isa<RecordType>(C1)) 4783 continue; 4784 // heuristic to reduce number of builtin candidates in the set. 4785 // Add volatile/restrict version only if there are conversions to a 4786 // volatile/restrict type. 4787 if (!VisibleTypeConversionsQuals.hasVolatile() && Q1.hasVolatile()) 4788 continue; 4789 if (!VisibleTypeConversionsQuals.hasRestrict() && Q1.hasRestrict()) 4790 continue; 4791 } 4792 for (BuiltinCandidateTypeSet::iterator 4793 MemPtr = CandidateTypes.member_pointer_begin(), 4794 MemPtrEnd = CandidateTypes.member_pointer_end(); 4795 MemPtr != MemPtrEnd; ++MemPtr) { 4796 const MemberPointerType *mptr = cast<MemberPointerType>(*MemPtr); 4797 QualType C2 = QualType(mptr->getClass(), 0); 4798 C2 = C2.getUnqualifiedType(); 4799 if (C1 != C2 && !IsDerivedFrom(C1, C2)) 4800 break; 4801 QualType ParamTypes[2] = { *Ptr, *MemPtr }; 4802 // build CV12 T& 4803 QualType T = mptr->getPointeeType(); 4804 if (!VisibleTypeConversionsQuals.hasVolatile() && 4805 T.isVolatileQualified()) 4806 continue; 4807 if (!VisibleTypeConversionsQuals.hasRestrict() && 4808 T.isRestrictQualified()) 4809 continue; 4810 T = Q1.apply(T); 4811 QualType ResultTy = Context.getLValueReferenceType(T); 4812 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 4813 } 4814 } 4815 } 4816 break; 4817 4818 case OO_Conditional: 4819 // Note that we don't consider the first argument, since it has been 4820 // contextually converted to bool long ago. The candidates below are 4821 // therefore added as binary. 4822 // 4823 // C++ [over.built]p24: 4824 // For every type T, where T is a pointer or pointer-to-member type, 4825 // there exist candidate operator functions of the form 4826 // 4827 // T operator?(bool, T, T); 4828 // 4829 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(), 4830 E = CandidateTypes.pointer_end(); Ptr != E; ++Ptr) { 4831 QualType ParamTypes[2] = { *Ptr, *Ptr }; 4832 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 4833 } 4834 for (BuiltinCandidateTypeSet::iterator Ptr = 4835 CandidateTypes.member_pointer_begin(), 4836 E = CandidateTypes.member_pointer_end(); Ptr != E; ++Ptr) { 4837 QualType ParamTypes[2] = { *Ptr, *Ptr }; 4838 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 4839 } 4840 goto Conditional; 4841 } 4842} 4843 4844/// \brief Add function candidates found via argument-dependent lookup 4845/// to the set of overloading candidates. 4846/// 4847/// This routine performs argument-dependent name lookup based on the 4848/// given function name (which may also be an operator name) and adds 4849/// all of the overload candidates found by ADL to the overload 4850/// candidate set (C++ [basic.lookup.argdep]). 4851void 4852Sema::AddArgumentDependentLookupCandidates(DeclarationName Name, 4853 bool Operator, 4854 Expr **Args, unsigned NumArgs, 4855 const TemplateArgumentListInfo *ExplicitTemplateArgs, 4856 OverloadCandidateSet& CandidateSet, 4857 bool PartialOverloading) { 4858 ADLResult Fns; 4859 4860 // FIXME: This approach for uniquing ADL results (and removing 4861 // redundant candidates from the set) relies on pointer-equality, 4862 // which means we need to key off the canonical decl. However, 4863 // always going back to the canonical decl might not get us the 4864 // right set of default arguments. What default arguments are 4865 // we supposed to consider on ADL candidates, anyway? 4866 4867 // FIXME: Pass in the explicit template arguments? 4868 ArgumentDependentLookup(Name, Operator, Args, NumArgs, Fns); 4869 4870 // Erase all of the candidates we already knew about. 4871 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 4872 CandEnd = CandidateSet.end(); 4873 Cand != CandEnd; ++Cand) 4874 if (Cand->Function) { 4875 Fns.erase(Cand->Function); 4876 if (FunctionTemplateDecl *FunTmpl = Cand->Function->getPrimaryTemplate()) 4877 Fns.erase(FunTmpl); 4878 } 4879 4880 // For each of the ADL candidates we found, add it to the overload 4881 // set. 4882 for (ADLResult::iterator I = Fns.begin(), E = Fns.end(); I != E; ++I) { 4883 DeclAccessPair FoundDecl = DeclAccessPair::make(*I, AS_none); 4884 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*I)) { 4885 if (ExplicitTemplateArgs) 4886 continue; 4887 4888 AddOverloadCandidate(FD, FoundDecl, Args, NumArgs, CandidateSet, 4889 false, PartialOverloading); 4890 } else 4891 AddTemplateOverloadCandidate(cast<FunctionTemplateDecl>(*I), 4892 FoundDecl, ExplicitTemplateArgs, 4893 Args, NumArgs, CandidateSet); 4894 } 4895} 4896 4897/// isBetterOverloadCandidate - Determines whether the first overload 4898/// candidate is a better candidate than the second (C++ 13.3.3p1). 4899bool 4900Sema::isBetterOverloadCandidate(const OverloadCandidate& Cand1, 4901 const OverloadCandidate& Cand2, 4902 SourceLocation Loc) { 4903 // Define viable functions to be better candidates than non-viable 4904 // functions. 4905 if (!Cand2.Viable) 4906 return Cand1.Viable; 4907 else if (!Cand1.Viable) 4908 return false; 4909 4910 // C++ [over.match.best]p1: 4911 // 4912 // -- if F is a static member function, ICS1(F) is defined such 4913 // that ICS1(F) is neither better nor worse than ICS1(G) for 4914 // any function G, and, symmetrically, ICS1(G) is neither 4915 // better nor worse than ICS1(F). 4916 unsigned StartArg = 0; 4917 if (Cand1.IgnoreObjectArgument || Cand2.IgnoreObjectArgument) 4918 StartArg = 1; 4919 4920 // C++ [over.match.best]p1: 4921 // A viable function F1 is defined to be a better function than another 4922 // viable function F2 if for all arguments i, ICSi(F1) is not a worse 4923 // conversion sequence than ICSi(F2), and then... 4924 unsigned NumArgs = Cand1.Conversions.size(); 4925 assert(Cand2.Conversions.size() == NumArgs && "Overload candidate mismatch"); 4926 bool HasBetterConversion = false; 4927 for (unsigned ArgIdx = StartArg; ArgIdx < NumArgs; ++ArgIdx) { 4928 switch (CompareImplicitConversionSequences(Cand1.Conversions[ArgIdx], 4929 Cand2.Conversions[ArgIdx])) { 4930 case ImplicitConversionSequence::Better: 4931 // Cand1 has a better conversion sequence. 4932 HasBetterConversion = true; 4933 break; 4934 4935 case ImplicitConversionSequence::Worse: 4936 // Cand1 can't be better than Cand2. 4937 return false; 4938 4939 case ImplicitConversionSequence::Indistinguishable: 4940 // Do nothing. 4941 break; 4942 } 4943 } 4944 4945 // -- for some argument j, ICSj(F1) is a better conversion sequence than 4946 // ICSj(F2), or, if not that, 4947 if (HasBetterConversion) 4948 return true; 4949 4950 // - F1 is a non-template function and F2 is a function template 4951 // specialization, or, if not that, 4952 if (Cand1.Function && !Cand1.Function->getPrimaryTemplate() && 4953 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 4954 return true; 4955 4956 // -- F1 and F2 are function template specializations, and the function 4957 // template for F1 is more specialized than the template for F2 4958 // according to the partial ordering rules described in 14.5.5.2, or, 4959 // if not that, 4960 if (Cand1.Function && Cand1.Function->getPrimaryTemplate() && 4961 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 4962 if (FunctionTemplateDecl *BetterTemplate 4963 = getMoreSpecializedTemplate(Cand1.Function->getPrimaryTemplate(), 4964 Cand2.Function->getPrimaryTemplate(), 4965 Loc, 4966 isa<CXXConversionDecl>(Cand1.Function)? TPOC_Conversion 4967 : TPOC_Call)) 4968 return BetterTemplate == Cand1.Function->getPrimaryTemplate(); 4969 4970 // -- the context is an initialization by user-defined conversion 4971 // (see 8.5, 13.3.1.5) and the standard conversion sequence 4972 // from the return type of F1 to the destination type (i.e., 4973 // the type of the entity being initialized) is a better 4974 // conversion sequence than the standard conversion sequence 4975 // from the return type of F2 to the destination type. 4976 if (Cand1.Function && Cand2.Function && 4977 isa<CXXConversionDecl>(Cand1.Function) && 4978 isa<CXXConversionDecl>(Cand2.Function)) { 4979 switch (CompareStandardConversionSequences(Cand1.FinalConversion, 4980 Cand2.FinalConversion)) { 4981 case ImplicitConversionSequence::Better: 4982 // Cand1 has a better conversion sequence. 4983 return true; 4984 4985 case ImplicitConversionSequence::Worse: 4986 // Cand1 can't be better than Cand2. 4987 return false; 4988 4989 case ImplicitConversionSequence::Indistinguishable: 4990 // Do nothing 4991 break; 4992 } 4993 } 4994 4995 return false; 4996} 4997 4998/// \brief Computes the best viable function (C++ 13.3.3) 4999/// within an overload candidate set. 5000/// 5001/// \param CandidateSet the set of candidate functions. 5002/// 5003/// \param Loc the location of the function name (or operator symbol) for 5004/// which overload resolution occurs. 5005/// 5006/// \param Best f overload resolution was successful or found a deleted 5007/// function, Best points to the candidate function found. 5008/// 5009/// \returns The result of overload resolution. 5010OverloadingResult Sema::BestViableFunction(OverloadCandidateSet& CandidateSet, 5011 SourceLocation Loc, 5012 OverloadCandidateSet::iterator& Best) { 5013 // Find the best viable function. 5014 Best = CandidateSet.end(); 5015 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 5016 Cand != CandidateSet.end(); ++Cand) { 5017 if (Cand->Viable) { 5018 if (Best == CandidateSet.end() || 5019 isBetterOverloadCandidate(*Cand, *Best, Loc)) 5020 Best = Cand; 5021 } 5022 } 5023 5024 // If we didn't find any viable functions, abort. 5025 if (Best == CandidateSet.end()) 5026 return OR_No_Viable_Function; 5027 5028 // Make sure that this function is better than every other viable 5029 // function. If not, we have an ambiguity. 5030 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 5031 Cand != CandidateSet.end(); ++Cand) { 5032 if (Cand->Viable && 5033 Cand != Best && 5034 !isBetterOverloadCandidate(*Best, *Cand, Loc)) { 5035 Best = CandidateSet.end(); 5036 return OR_Ambiguous; 5037 } 5038 } 5039 5040 // Best is the best viable function. 5041 if (Best->Function && 5042 (Best->Function->isDeleted() || 5043 Best->Function->getAttr<UnavailableAttr>())) 5044 return OR_Deleted; 5045 5046 // C++ [basic.def.odr]p2: 5047 // An overloaded function is used if it is selected by overload resolution 5048 // when referred to from a potentially-evaluated expression. [Note: this 5049 // covers calls to named functions (5.2.2), operator overloading 5050 // (clause 13), user-defined conversions (12.3.2), allocation function for 5051 // placement new (5.3.4), as well as non-default initialization (8.5). 5052 if (Best->Function) 5053 MarkDeclarationReferenced(Loc, Best->Function); 5054 return OR_Success; 5055} 5056 5057namespace { 5058 5059enum OverloadCandidateKind { 5060 oc_function, 5061 oc_method, 5062 oc_constructor, 5063 oc_function_template, 5064 oc_method_template, 5065 oc_constructor_template, 5066 oc_implicit_default_constructor, 5067 oc_implicit_copy_constructor, 5068 oc_implicit_copy_assignment 5069}; 5070 5071OverloadCandidateKind ClassifyOverloadCandidate(Sema &S, 5072 FunctionDecl *Fn, 5073 std::string &Description) { 5074 bool isTemplate = false; 5075 5076 if (FunctionTemplateDecl *FunTmpl = Fn->getPrimaryTemplate()) { 5077 isTemplate = true; 5078 Description = S.getTemplateArgumentBindingsText( 5079 FunTmpl->getTemplateParameters(), *Fn->getTemplateSpecializationArgs()); 5080 } 5081 5082 if (CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(Fn)) { 5083 if (!Ctor->isImplicit()) 5084 return isTemplate ? oc_constructor_template : oc_constructor; 5085 5086 return Ctor->isCopyConstructor() ? oc_implicit_copy_constructor 5087 : oc_implicit_default_constructor; 5088 } 5089 5090 if (CXXMethodDecl *Meth = dyn_cast<CXXMethodDecl>(Fn)) { 5091 // This actually gets spelled 'candidate function' for now, but 5092 // it doesn't hurt to split it out. 5093 if (!Meth->isImplicit()) 5094 return isTemplate ? oc_method_template : oc_method; 5095 5096 assert(Meth->isCopyAssignment() 5097 && "implicit method is not copy assignment operator?"); 5098 return oc_implicit_copy_assignment; 5099 } 5100 5101 return isTemplate ? oc_function_template : oc_function; 5102} 5103 5104} // end anonymous namespace 5105 5106// Notes the location of an overload candidate. 5107void Sema::NoteOverloadCandidate(FunctionDecl *Fn) { 5108 std::string FnDesc; 5109 OverloadCandidateKind K = ClassifyOverloadCandidate(*this, Fn, FnDesc); 5110 Diag(Fn->getLocation(), diag::note_ovl_candidate) 5111 << (unsigned) K << FnDesc; 5112} 5113 5114/// Diagnoses an ambiguous conversion. The partial diagnostic is the 5115/// "lead" diagnostic; it will be given two arguments, the source and 5116/// target types of the conversion. 5117void Sema::DiagnoseAmbiguousConversion(const ImplicitConversionSequence &ICS, 5118 SourceLocation CaretLoc, 5119 const PartialDiagnostic &PDiag) { 5120 Diag(CaretLoc, PDiag) 5121 << ICS.Ambiguous.getFromType() << ICS.Ambiguous.getToType(); 5122 for (AmbiguousConversionSequence::const_iterator 5123 I = ICS.Ambiguous.begin(), E = ICS.Ambiguous.end(); I != E; ++I) { 5124 NoteOverloadCandidate(*I); 5125 } 5126} 5127 5128namespace { 5129 5130void DiagnoseBadConversion(Sema &S, OverloadCandidate *Cand, unsigned I) { 5131 const ImplicitConversionSequence &Conv = Cand->Conversions[I]; 5132 assert(Conv.isBad()); 5133 assert(Cand->Function && "for now, candidate must be a function"); 5134 FunctionDecl *Fn = Cand->Function; 5135 5136 // There's a conversion slot for the object argument if this is a 5137 // non-constructor method. Note that 'I' corresponds the 5138 // conversion-slot index. 5139 bool isObjectArgument = false; 5140 if (isa<CXXMethodDecl>(Fn) && !isa<CXXConstructorDecl>(Fn)) { 5141 if (I == 0) 5142 isObjectArgument = true; 5143 else 5144 I--; 5145 } 5146 5147 std::string FnDesc; 5148 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, FnDesc); 5149 5150 Expr *FromExpr = Conv.Bad.FromExpr; 5151 QualType FromTy = Conv.Bad.getFromType(); 5152 QualType ToTy = Conv.Bad.getToType(); 5153 5154 if (FromTy == S.Context.OverloadTy) { 5155 assert(FromExpr && "overload set argument came from implicit argument?"); 5156 Expr *E = FromExpr->IgnoreParens(); 5157 if (isa<UnaryOperator>(E)) 5158 E = cast<UnaryOperator>(E)->getSubExpr()->IgnoreParens(); 5159 DeclarationName Name = cast<OverloadExpr>(E)->getName(); 5160 5161 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_overload) 5162 << (unsigned) FnKind << FnDesc 5163 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 5164 << ToTy << Name << I+1; 5165 return; 5166 } 5167 5168 // Do some hand-waving analysis to see if the non-viability is due 5169 // to a qualifier mismatch. 5170 CanQualType CFromTy = S.Context.getCanonicalType(FromTy); 5171 CanQualType CToTy = S.Context.getCanonicalType(ToTy); 5172 if (CanQual<ReferenceType> RT = CToTy->getAs<ReferenceType>()) 5173 CToTy = RT->getPointeeType(); 5174 else { 5175 // TODO: detect and diagnose the full richness of const mismatches. 5176 if (CanQual<PointerType> FromPT = CFromTy->getAs<PointerType>()) 5177 if (CanQual<PointerType> ToPT = CToTy->getAs<PointerType>()) 5178 CFromTy = FromPT->getPointeeType(), CToTy = ToPT->getPointeeType(); 5179 } 5180 5181 if (CToTy.getUnqualifiedType() == CFromTy.getUnqualifiedType() && 5182 !CToTy.isAtLeastAsQualifiedAs(CFromTy)) { 5183 // It is dumb that we have to do this here. 5184 while (isa<ArrayType>(CFromTy)) 5185 CFromTy = CFromTy->getAs<ArrayType>()->getElementType(); 5186 while (isa<ArrayType>(CToTy)) 5187 CToTy = CFromTy->getAs<ArrayType>()->getElementType(); 5188 5189 Qualifiers FromQs = CFromTy.getQualifiers(); 5190 Qualifiers ToQs = CToTy.getQualifiers(); 5191 5192 if (FromQs.getAddressSpace() != ToQs.getAddressSpace()) { 5193 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_addrspace) 5194 << (unsigned) FnKind << FnDesc 5195 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 5196 << FromTy 5197 << FromQs.getAddressSpace() << ToQs.getAddressSpace() 5198 << (unsigned) isObjectArgument << I+1; 5199 return; 5200 } 5201 5202 unsigned CVR = FromQs.getCVRQualifiers() & ~ToQs.getCVRQualifiers(); 5203 assert(CVR && "unexpected qualifiers mismatch"); 5204 5205 if (isObjectArgument) { 5206 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr_this) 5207 << (unsigned) FnKind << FnDesc 5208 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 5209 << FromTy << (CVR - 1); 5210 } else { 5211 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr) 5212 << (unsigned) FnKind << FnDesc 5213 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 5214 << FromTy << (CVR - 1) << I+1; 5215 } 5216 return; 5217 } 5218 5219 // Diagnose references or pointers to incomplete types differently, 5220 // since it's far from impossible that the incompleteness triggered 5221 // the failure. 5222 QualType TempFromTy = FromTy.getNonReferenceType(); 5223 if (const PointerType *PTy = TempFromTy->getAs<PointerType>()) 5224 TempFromTy = PTy->getPointeeType(); 5225 if (TempFromTy->isIncompleteType()) { 5226 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_conv_incomplete) 5227 << (unsigned) FnKind << FnDesc 5228 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 5229 << FromTy << ToTy << (unsigned) isObjectArgument << I+1; 5230 return; 5231 } 5232 5233 // TODO: specialize more based on the kind of mismatch 5234 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_conv) 5235 << (unsigned) FnKind << FnDesc 5236 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 5237 << FromTy << ToTy << (unsigned) isObjectArgument << I+1; 5238} 5239 5240void DiagnoseArityMismatch(Sema &S, OverloadCandidate *Cand, 5241 unsigned NumFormalArgs) { 5242 // TODO: treat calls to a missing default constructor as a special case 5243 5244 FunctionDecl *Fn = Cand->Function; 5245 const FunctionProtoType *FnTy = Fn->getType()->getAs<FunctionProtoType>(); 5246 5247 unsigned MinParams = Fn->getMinRequiredArguments(); 5248 5249 // at least / at most / exactly 5250 // FIXME: variadic templates "at most" should account for parameter packs 5251 unsigned mode, modeCount; 5252 if (NumFormalArgs < MinParams) { 5253 assert((Cand->FailureKind == ovl_fail_too_few_arguments) || 5254 (Cand->FailureKind == ovl_fail_bad_deduction && 5255 Cand->DeductionFailure.Result == Sema::TDK_TooFewArguments)); 5256 if (MinParams != FnTy->getNumArgs() || FnTy->isVariadic()) 5257 mode = 0; // "at least" 5258 else 5259 mode = 2; // "exactly" 5260 modeCount = MinParams; 5261 } else { 5262 assert((Cand->FailureKind == ovl_fail_too_many_arguments) || 5263 (Cand->FailureKind == ovl_fail_bad_deduction && 5264 Cand->DeductionFailure.Result == Sema::TDK_TooManyArguments)); 5265 if (MinParams != FnTy->getNumArgs()) 5266 mode = 1; // "at most" 5267 else 5268 mode = 2; // "exactly" 5269 modeCount = FnTy->getNumArgs(); 5270 } 5271 5272 std::string Description; 5273 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, Description); 5274 5275 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_arity) 5276 << (unsigned) FnKind << (Fn->getDescribedFunctionTemplate() != 0) << mode 5277 << modeCount << NumFormalArgs; 5278} 5279 5280/// Diagnose a failed template-argument deduction. 5281void DiagnoseBadDeduction(Sema &S, OverloadCandidate *Cand, 5282 Expr **Args, unsigned NumArgs) { 5283 FunctionDecl *Fn = Cand->Function; // pattern 5284 5285 TemplateParameter Param = Cand->DeductionFailure.getTemplateParameter(); 5286 NamedDecl *ParamD; 5287 (ParamD = Param.dyn_cast<TemplateTypeParmDecl*>()) || 5288 (ParamD = Param.dyn_cast<NonTypeTemplateParmDecl*>()) || 5289 (ParamD = Param.dyn_cast<TemplateTemplateParmDecl*>()); 5290 switch (Cand->DeductionFailure.Result) { 5291 case Sema::TDK_Success: 5292 llvm_unreachable("TDK_success while diagnosing bad deduction"); 5293 5294 case Sema::TDK_Incomplete: { 5295 assert(ParamD && "no parameter found for incomplete deduction result"); 5296 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_incomplete_deduction) 5297 << ParamD->getDeclName(); 5298 return; 5299 } 5300 5301 case Sema::TDK_Inconsistent: 5302 case Sema::TDK_InconsistentQuals: { 5303 assert(ParamD && "no parameter found for inconsistent deduction result"); 5304 int which = 0; 5305 if (isa<TemplateTypeParmDecl>(ParamD)) 5306 which = 0; 5307 else if (isa<NonTypeTemplateParmDecl>(ParamD)) 5308 which = 1; 5309 else { 5310 which = 2; 5311 } 5312 5313 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_inconsistent_deduction) 5314 << which << ParamD->getDeclName() 5315 << *Cand->DeductionFailure.getFirstArg() 5316 << *Cand->DeductionFailure.getSecondArg(); 5317 return; 5318 } 5319 5320 case Sema::TDK_InvalidExplicitArguments: 5321 assert(ParamD && "no parameter found for invalid explicit arguments"); 5322 if (ParamD->getDeclName()) 5323 S.Diag(Fn->getLocation(), 5324 diag::note_ovl_candidate_explicit_arg_mismatch_named) 5325 << ParamD->getDeclName(); 5326 else { 5327 int index = 0; 5328 if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(ParamD)) 5329 index = TTP->getIndex(); 5330 else if (NonTypeTemplateParmDecl *NTTP 5331 = dyn_cast<NonTypeTemplateParmDecl>(ParamD)) 5332 index = NTTP->getIndex(); 5333 else 5334 index = cast<TemplateTemplateParmDecl>(ParamD)->getIndex(); 5335 S.Diag(Fn->getLocation(), 5336 diag::note_ovl_candidate_explicit_arg_mismatch_unnamed) 5337 << (index + 1); 5338 } 5339 return; 5340 5341 case Sema::TDK_TooManyArguments: 5342 case Sema::TDK_TooFewArguments: 5343 DiagnoseArityMismatch(S, Cand, NumArgs); 5344 return; 5345 5346 case Sema::TDK_InstantiationDepth: 5347 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_instantiation_depth); 5348 return; 5349 5350 case Sema::TDK_SubstitutionFailure: { 5351 std::string ArgString; 5352 if (TemplateArgumentList *Args 5353 = Cand->DeductionFailure.getTemplateArgumentList()) 5354 ArgString = S.getTemplateArgumentBindingsText( 5355 Fn->getDescribedFunctionTemplate()->getTemplateParameters(), 5356 *Args); 5357 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_substitution_failure) 5358 << ArgString; 5359 return; 5360 } 5361 5362 // TODO: diagnose these individually, then kill off 5363 // note_ovl_candidate_bad_deduction, which is uselessly vague. 5364 case Sema::TDK_NonDeducedMismatch: 5365 case Sema::TDK_FailedOverloadResolution: 5366 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_deduction); 5367 return; 5368 } 5369} 5370 5371/// Generates a 'note' diagnostic for an overload candidate. We've 5372/// already generated a primary error at the call site. 5373/// 5374/// It really does need to be a single diagnostic with its caret 5375/// pointed at the candidate declaration. Yes, this creates some 5376/// major challenges of technical writing. Yes, this makes pointing 5377/// out problems with specific arguments quite awkward. It's still 5378/// better than generating twenty screens of text for every failed 5379/// overload. 5380/// 5381/// It would be great to be able to express per-candidate problems 5382/// more richly for those diagnostic clients that cared, but we'd 5383/// still have to be just as careful with the default diagnostics. 5384void NoteFunctionCandidate(Sema &S, OverloadCandidate *Cand, 5385 Expr **Args, unsigned NumArgs) { 5386 FunctionDecl *Fn = Cand->Function; 5387 5388 // Note deleted candidates, but only if they're viable. 5389 if (Cand->Viable && (Fn->isDeleted() || Fn->hasAttr<UnavailableAttr>())) { 5390 std::string FnDesc; 5391 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, FnDesc); 5392 5393 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_deleted) 5394 << FnKind << FnDesc << Fn->isDeleted(); 5395 return; 5396 } 5397 5398 // We don't really have anything else to say about viable candidates. 5399 if (Cand->Viable) { 5400 S.NoteOverloadCandidate(Fn); 5401 return; 5402 } 5403 5404 switch (Cand->FailureKind) { 5405 case ovl_fail_too_many_arguments: 5406 case ovl_fail_too_few_arguments: 5407 return DiagnoseArityMismatch(S, Cand, NumArgs); 5408 5409 case ovl_fail_bad_deduction: 5410 return DiagnoseBadDeduction(S, Cand, Args, NumArgs); 5411 5412 case ovl_fail_trivial_conversion: 5413 case ovl_fail_bad_final_conversion: 5414 case ovl_fail_final_conversion_not_exact: 5415 return S.NoteOverloadCandidate(Fn); 5416 5417 case ovl_fail_bad_conversion: { 5418 unsigned I = (Cand->IgnoreObjectArgument ? 1 : 0); 5419 for (unsigned N = Cand->Conversions.size(); I != N; ++I) 5420 if (Cand->Conversions[I].isBad()) 5421 return DiagnoseBadConversion(S, Cand, I); 5422 5423 // FIXME: this currently happens when we're called from SemaInit 5424 // when user-conversion overload fails. Figure out how to handle 5425 // those conditions and diagnose them well. 5426 return S.NoteOverloadCandidate(Fn); 5427 } 5428 } 5429} 5430 5431void NoteSurrogateCandidate(Sema &S, OverloadCandidate *Cand) { 5432 // Desugar the type of the surrogate down to a function type, 5433 // retaining as many typedefs as possible while still showing 5434 // the function type (and, therefore, its parameter types). 5435 QualType FnType = Cand->Surrogate->getConversionType(); 5436 bool isLValueReference = false; 5437 bool isRValueReference = false; 5438 bool isPointer = false; 5439 if (const LValueReferenceType *FnTypeRef = 5440 FnType->getAs<LValueReferenceType>()) { 5441 FnType = FnTypeRef->getPointeeType(); 5442 isLValueReference = true; 5443 } else if (const RValueReferenceType *FnTypeRef = 5444 FnType->getAs<RValueReferenceType>()) { 5445 FnType = FnTypeRef->getPointeeType(); 5446 isRValueReference = true; 5447 } 5448 if (const PointerType *FnTypePtr = FnType->getAs<PointerType>()) { 5449 FnType = FnTypePtr->getPointeeType(); 5450 isPointer = true; 5451 } 5452 // Desugar down to a function type. 5453 FnType = QualType(FnType->getAs<FunctionType>(), 0); 5454 // Reconstruct the pointer/reference as appropriate. 5455 if (isPointer) FnType = S.Context.getPointerType(FnType); 5456 if (isRValueReference) FnType = S.Context.getRValueReferenceType(FnType); 5457 if (isLValueReference) FnType = S.Context.getLValueReferenceType(FnType); 5458 5459 S.Diag(Cand->Surrogate->getLocation(), diag::note_ovl_surrogate_cand) 5460 << FnType; 5461} 5462 5463void NoteBuiltinOperatorCandidate(Sema &S, 5464 const char *Opc, 5465 SourceLocation OpLoc, 5466 OverloadCandidate *Cand) { 5467 assert(Cand->Conversions.size() <= 2 && "builtin operator is not binary"); 5468 std::string TypeStr("operator"); 5469 TypeStr += Opc; 5470 TypeStr += "("; 5471 TypeStr += Cand->BuiltinTypes.ParamTypes[0].getAsString(); 5472 if (Cand->Conversions.size() == 1) { 5473 TypeStr += ")"; 5474 S.Diag(OpLoc, diag::note_ovl_builtin_unary_candidate) << TypeStr; 5475 } else { 5476 TypeStr += ", "; 5477 TypeStr += Cand->BuiltinTypes.ParamTypes[1].getAsString(); 5478 TypeStr += ")"; 5479 S.Diag(OpLoc, diag::note_ovl_builtin_binary_candidate) << TypeStr; 5480 } 5481} 5482 5483void NoteAmbiguousUserConversions(Sema &S, SourceLocation OpLoc, 5484 OverloadCandidate *Cand) { 5485 unsigned NoOperands = Cand->Conversions.size(); 5486 for (unsigned ArgIdx = 0; ArgIdx < NoOperands; ++ArgIdx) { 5487 const ImplicitConversionSequence &ICS = Cand->Conversions[ArgIdx]; 5488 if (ICS.isBad()) break; // all meaningless after first invalid 5489 if (!ICS.isAmbiguous()) continue; 5490 5491 S.DiagnoseAmbiguousConversion(ICS, OpLoc, 5492 S.PDiag(diag::note_ambiguous_type_conversion)); 5493 } 5494} 5495 5496SourceLocation GetLocationForCandidate(const OverloadCandidate *Cand) { 5497 if (Cand->Function) 5498 return Cand->Function->getLocation(); 5499 if (Cand->IsSurrogate) 5500 return Cand->Surrogate->getLocation(); 5501 return SourceLocation(); 5502} 5503 5504struct CompareOverloadCandidatesForDisplay { 5505 Sema &S; 5506 CompareOverloadCandidatesForDisplay(Sema &S) : S(S) {} 5507 5508 bool operator()(const OverloadCandidate *L, 5509 const OverloadCandidate *R) { 5510 // Fast-path this check. 5511 if (L == R) return false; 5512 5513 // Order first by viability. 5514 if (L->Viable) { 5515 if (!R->Viable) return true; 5516 5517 // TODO: introduce a tri-valued comparison for overload 5518 // candidates. Would be more worthwhile if we had a sort 5519 // that could exploit it. 5520 if (S.isBetterOverloadCandidate(*L, *R, SourceLocation())) return true; 5521 if (S.isBetterOverloadCandidate(*R, *L, SourceLocation())) return false; 5522 } else if (R->Viable) 5523 return false; 5524 5525 assert(L->Viable == R->Viable); 5526 5527 // Criteria by which we can sort non-viable candidates: 5528 if (!L->Viable) { 5529 // 1. Arity mismatches come after other candidates. 5530 if (L->FailureKind == ovl_fail_too_many_arguments || 5531 L->FailureKind == ovl_fail_too_few_arguments) 5532 return false; 5533 if (R->FailureKind == ovl_fail_too_many_arguments || 5534 R->FailureKind == ovl_fail_too_few_arguments) 5535 return true; 5536 5537 // 2. Bad conversions come first and are ordered by the number 5538 // of bad conversions and quality of good conversions. 5539 if (L->FailureKind == ovl_fail_bad_conversion) { 5540 if (R->FailureKind != ovl_fail_bad_conversion) 5541 return true; 5542 5543 // If there's any ordering between the defined conversions... 5544 // FIXME: this might not be transitive. 5545 assert(L->Conversions.size() == R->Conversions.size()); 5546 5547 int leftBetter = 0; 5548 unsigned I = (L->IgnoreObjectArgument || R->IgnoreObjectArgument); 5549 for (unsigned E = L->Conversions.size(); I != E; ++I) { 5550 switch (S.CompareImplicitConversionSequences(L->Conversions[I], 5551 R->Conversions[I])) { 5552 case ImplicitConversionSequence::Better: 5553 leftBetter++; 5554 break; 5555 5556 case ImplicitConversionSequence::Worse: 5557 leftBetter--; 5558 break; 5559 5560 case ImplicitConversionSequence::Indistinguishable: 5561 break; 5562 } 5563 } 5564 if (leftBetter > 0) return true; 5565 if (leftBetter < 0) return false; 5566 5567 } else if (R->FailureKind == ovl_fail_bad_conversion) 5568 return false; 5569 5570 // TODO: others? 5571 } 5572 5573 // Sort everything else by location. 5574 SourceLocation LLoc = GetLocationForCandidate(L); 5575 SourceLocation RLoc = GetLocationForCandidate(R); 5576 5577 // Put candidates without locations (e.g. builtins) at the end. 5578 if (LLoc.isInvalid()) return false; 5579 if (RLoc.isInvalid()) return true; 5580 5581 return S.SourceMgr.isBeforeInTranslationUnit(LLoc, RLoc); 5582 } 5583}; 5584 5585/// CompleteNonViableCandidate - Normally, overload resolution only 5586/// computes up to the first 5587void CompleteNonViableCandidate(Sema &S, OverloadCandidate *Cand, 5588 Expr **Args, unsigned NumArgs) { 5589 assert(!Cand->Viable); 5590 5591 // Don't do anything on failures other than bad conversion. 5592 if (Cand->FailureKind != ovl_fail_bad_conversion) return; 5593 5594 // Skip forward to the first bad conversion. 5595 unsigned ConvIdx = (Cand->IgnoreObjectArgument ? 1 : 0); 5596 unsigned ConvCount = Cand->Conversions.size(); 5597 while (true) { 5598 assert(ConvIdx != ConvCount && "no bad conversion in candidate"); 5599 ConvIdx++; 5600 if (Cand->Conversions[ConvIdx - 1].isBad()) 5601 break; 5602 } 5603 5604 if (ConvIdx == ConvCount) 5605 return; 5606 5607 assert(!Cand->Conversions[ConvIdx].isInitialized() && 5608 "remaining conversion is initialized?"); 5609 5610 // FIXME: this should probably be preserved from the overload 5611 // operation somehow. 5612 bool SuppressUserConversions = false; 5613 5614 const FunctionProtoType* Proto; 5615 unsigned ArgIdx = ConvIdx; 5616 5617 if (Cand->IsSurrogate) { 5618 QualType ConvType 5619 = Cand->Surrogate->getConversionType().getNonReferenceType(); 5620 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 5621 ConvType = ConvPtrType->getPointeeType(); 5622 Proto = ConvType->getAs<FunctionProtoType>(); 5623 ArgIdx--; 5624 } else if (Cand->Function) { 5625 Proto = Cand->Function->getType()->getAs<FunctionProtoType>(); 5626 if (isa<CXXMethodDecl>(Cand->Function) && 5627 !isa<CXXConstructorDecl>(Cand->Function)) 5628 ArgIdx--; 5629 } else { 5630 // Builtin binary operator with a bad first conversion. 5631 assert(ConvCount <= 3); 5632 for (; ConvIdx != ConvCount; ++ConvIdx) 5633 Cand->Conversions[ConvIdx] 5634 = TryCopyInitialization(S, Args[ConvIdx], 5635 Cand->BuiltinTypes.ParamTypes[ConvIdx], 5636 SuppressUserConversions, 5637 /*InOverloadResolution*/ true); 5638 return; 5639 } 5640 5641 // Fill in the rest of the conversions. 5642 unsigned NumArgsInProto = Proto->getNumArgs(); 5643 for (; ConvIdx != ConvCount; ++ConvIdx, ++ArgIdx) { 5644 if (ArgIdx < NumArgsInProto) 5645 Cand->Conversions[ConvIdx] 5646 = TryCopyInitialization(S, Args[ArgIdx], Proto->getArgType(ArgIdx), 5647 SuppressUserConversions, 5648 /*InOverloadResolution=*/true); 5649 else 5650 Cand->Conversions[ConvIdx].setEllipsis(); 5651 } 5652} 5653 5654} // end anonymous namespace 5655 5656/// PrintOverloadCandidates - When overload resolution fails, prints 5657/// diagnostic messages containing the candidates in the candidate 5658/// set. 5659void 5660Sema::PrintOverloadCandidates(OverloadCandidateSet& CandidateSet, 5661 OverloadCandidateDisplayKind OCD, 5662 Expr **Args, unsigned NumArgs, 5663 const char *Opc, 5664 SourceLocation OpLoc) { 5665 // Sort the candidates by viability and position. Sorting directly would 5666 // be prohibitive, so we make a set of pointers and sort those. 5667 llvm::SmallVector<OverloadCandidate*, 32> Cands; 5668 if (OCD == OCD_AllCandidates) Cands.reserve(CandidateSet.size()); 5669 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 5670 LastCand = CandidateSet.end(); 5671 Cand != LastCand; ++Cand) { 5672 if (Cand->Viable) 5673 Cands.push_back(Cand); 5674 else if (OCD == OCD_AllCandidates) { 5675 CompleteNonViableCandidate(*this, Cand, Args, NumArgs); 5676 Cands.push_back(Cand); 5677 } 5678 } 5679 5680 std::sort(Cands.begin(), Cands.end(), 5681 CompareOverloadCandidatesForDisplay(*this)); 5682 5683 bool ReportedAmbiguousConversions = false; 5684 5685 llvm::SmallVectorImpl<OverloadCandidate*>::iterator I, E; 5686 for (I = Cands.begin(), E = Cands.end(); I != E; ++I) { 5687 OverloadCandidate *Cand = *I; 5688 5689 if (Cand->Function) 5690 NoteFunctionCandidate(*this, Cand, Args, NumArgs); 5691 else if (Cand->IsSurrogate) 5692 NoteSurrogateCandidate(*this, Cand); 5693 5694 // This a builtin candidate. We do not, in general, want to list 5695 // every possible builtin candidate. 5696 else if (Cand->Viable) { 5697 // Generally we only see ambiguities including viable builtin 5698 // operators if overload resolution got screwed up by an 5699 // ambiguous user-defined conversion. 5700 // 5701 // FIXME: It's quite possible for different conversions to see 5702 // different ambiguities, though. 5703 if (!ReportedAmbiguousConversions) { 5704 NoteAmbiguousUserConversions(*this, OpLoc, Cand); 5705 ReportedAmbiguousConversions = true; 5706 } 5707 5708 // If this is a viable builtin, print it. 5709 NoteBuiltinOperatorCandidate(*this, Opc, OpLoc, Cand); 5710 } 5711 } 5712} 5713 5714static bool CheckUnresolvedAccess(Sema &S, OverloadExpr *E, DeclAccessPair D) { 5715 if (isa<UnresolvedLookupExpr>(E)) 5716 return S.CheckUnresolvedLookupAccess(cast<UnresolvedLookupExpr>(E), D); 5717 5718 return S.CheckUnresolvedMemberAccess(cast<UnresolvedMemberExpr>(E), D); 5719} 5720 5721/// ResolveAddressOfOverloadedFunction - Try to resolve the address of 5722/// an overloaded function (C++ [over.over]), where @p From is an 5723/// expression with overloaded function type and @p ToType is the type 5724/// we're trying to resolve to. For example: 5725/// 5726/// @code 5727/// int f(double); 5728/// int f(int); 5729/// 5730/// int (*pfd)(double) = f; // selects f(double) 5731/// @endcode 5732/// 5733/// This routine returns the resulting FunctionDecl if it could be 5734/// resolved, and NULL otherwise. When @p Complain is true, this 5735/// routine will emit diagnostics if there is an error. 5736FunctionDecl * 5737Sema::ResolveAddressOfOverloadedFunction(Expr *From, QualType ToType, 5738 bool Complain, 5739 DeclAccessPair &FoundResult) { 5740 QualType FunctionType = ToType; 5741 bool IsMember = false; 5742 if (const PointerType *ToTypePtr = ToType->getAs<PointerType>()) 5743 FunctionType = ToTypePtr->getPointeeType(); 5744 else if (const ReferenceType *ToTypeRef = ToType->getAs<ReferenceType>()) 5745 FunctionType = ToTypeRef->getPointeeType(); 5746 else if (const MemberPointerType *MemTypePtr = 5747 ToType->getAs<MemberPointerType>()) { 5748 FunctionType = MemTypePtr->getPointeeType(); 5749 IsMember = true; 5750 } 5751 5752 // C++ [over.over]p1: 5753 // [...] [Note: any redundant set of parentheses surrounding the 5754 // overloaded function name is ignored (5.1). ] 5755 // C++ [over.over]p1: 5756 // [...] The overloaded function name can be preceded by the & 5757 // operator. 5758 OverloadExpr *OvlExpr = OverloadExpr::find(From).getPointer(); 5759 TemplateArgumentListInfo ETABuffer, *ExplicitTemplateArgs = 0; 5760 if (OvlExpr->hasExplicitTemplateArgs()) { 5761 OvlExpr->getExplicitTemplateArgs().copyInto(ETABuffer); 5762 ExplicitTemplateArgs = &ETABuffer; 5763 } 5764 5765 // We expect a pointer or reference to function, or a function pointer. 5766 FunctionType = Context.getCanonicalType(FunctionType).getUnqualifiedType(); 5767 if (!FunctionType->isFunctionType()) { 5768 if (Complain) 5769 Diag(From->getLocStart(), diag::err_addr_ovl_not_func_ptrref) 5770 << OvlExpr->getName() << ToType; 5771 5772 return 0; 5773 } 5774 5775 assert(From->getType() == Context.OverloadTy); 5776 5777 // Look through all of the overloaded functions, searching for one 5778 // whose type matches exactly. 5779 llvm::SmallVector<std::pair<DeclAccessPair, FunctionDecl*>, 4> Matches; 5780 llvm::SmallVector<FunctionDecl *, 4> NonMatches; 5781 5782 bool FoundNonTemplateFunction = false; 5783 for (UnresolvedSetIterator I = OvlExpr->decls_begin(), 5784 E = OvlExpr->decls_end(); I != E; ++I) { 5785 // Look through any using declarations to find the underlying function. 5786 NamedDecl *Fn = (*I)->getUnderlyingDecl(); 5787 5788 // C++ [over.over]p3: 5789 // Non-member functions and static member functions match 5790 // targets of type "pointer-to-function" or "reference-to-function." 5791 // Nonstatic member functions match targets of 5792 // type "pointer-to-member-function." 5793 // Note that according to DR 247, the containing class does not matter. 5794 5795 if (FunctionTemplateDecl *FunctionTemplate 5796 = dyn_cast<FunctionTemplateDecl>(Fn)) { 5797 if (CXXMethodDecl *Method 5798 = dyn_cast<CXXMethodDecl>(FunctionTemplate->getTemplatedDecl())) { 5799 // Skip non-static function templates when converting to pointer, and 5800 // static when converting to member pointer. 5801 if (Method->isStatic() == IsMember) 5802 continue; 5803 } else if (IsMember) 5804 continue; 5805 5806 // C++ [over.over]p2: 5807 // If the name is a function template, template argument deduction is 5808 // done (14.8.2.2), and if the argument deduction succeeds, the 5809 // resulting template argument list is used to generate a single 5810 // function template specialization, which is added to the set of 5811 // overloaded functions considered. 5812 // FIXME: We don't really want to build the specialization here, do we? 5813 FunctionDecl *Specialization = 0; 5814 TemplateDeductionInfo Info(Context, OvlExpr->getNameLoc()); 5815 if (TemplateDeductionResult Result 5816 = DeduceTemplateArguments(FunctionTemplate, ExplicitTemplateArgs, 5817 FunctionType, Specialization, Info)) { 5818 // FIXME: make a note of the failed deduction for diagnostics. 5819 (void)Result; 5820 } else { 5821 // FIXME: If the match isn't exact, shouldn't we just drop this as 5822 // a candidate? Find a testcase before changing the code. 5823 assert(FunctionType 5824 == Context.getCanonicalType(Specialization->getType())); 5825 Matches.push_back(std::make_pair(I.getPair(), 5826 cast<FunctionDecl>(Specialization->getCanonicalDecl()))); 5827 } 5828 5829 continue; 5830 } 5831 5832 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 5833 // Skip non-static functions when converting to pointer, and static 5834 // when converting to member pointer. 5835 if (Method->isStatic() == IsMember) 5836 continue; 5837 5838 // If we have explicit template arguments, skip non-templates. 5839 if (OvlExpr->hasExplicitTemplateArgs()) 5840 continue; 5841 } else if (IsMember) 5842 continue; 5843 5844 if (FunctionDecl *FunDecl = dyn_cast<FunctionDecl>(Fn)) { 5845 QualType ResultTy; 5846 if (Context.hasSameUnqualifiedType(FunctionType, FunDecl->getType()) || 5847 IsNoReturnConversion(Context, FunDecl->getType(), FunctionType, 5848 ResultTy)) { 5849 Matches.push_back(std::make_pair(I.getPair(), 5850 cast<FunctionDecl>(FunDecl->getCanonicalDecl()))); 5851 FoundNonTemplateFunction = true; 5852 } 5853 } 5854 } 5855 5856 // If there were 0 or 1 matches, we're done. 5857 if (Matches.empty()) { 5858 if (Complain) { 5859 Diag(From->getLocStart(), diag::err_addr_ovl_no_viable) 5860 << OvlExpr->getName() << FunctionType; 5861 for (UnresolvedSetIterator I = OvlExpr->decls_begin(), 5862 E = OvlExpr->decls_end(); 5863 I != E; ++I) 5864 if (FunctionDecl *F = dyn_cast<FunctionDecl>((*I)->getUnderlyingDecl())) 5865 NoteOverloadCandidate(F); 5866 } 5867 5868 return 0; 5869 } else if (Matches.size() == 1) { 5870 FunctionDecl *Result = Matches[0].second; 5871 FoundResult = Matches[0].first; 5872 MarkDeclarationReferenced(From->getLocStart(), Result); 5873 if (Complain) 5874 CheckAddressOfMemberAccess(OvlExpr, Matches[0].first); 5875 return Result; 5876 } 5877 5878 // C++ [over.over]p4: 5879 // If more than one function is selected, [...] 5880 if (!FoundNonTemplateFunction) { 5881 // [...] and any given function template specialization F1 is 5882 // eliminated if the set contains a second function template 5883 // specialization whose function template is more specialized 5884 // than the function template of F1 according to the partial 5885 // ordering rules of 14.5.5.2. 5886 5887 // The algorithm specified above is quadratic. We instead use a 5888 // two-pass algorithm (similar to the one used to identify the 5889 // best viable function in an overload set) that identifies the 5890 // best function template (if it exists). 5891 5892 UnresolvedSet<4> MatchesCopy; // TODO: avoid! 5893 for (unsigned I = 0, E = Matches.size(); I != E; ++I) 5894 MatchesCopy.addDecl(Matches[I].second, Matches[I].first.getAccess()); 5895 5896 UnresolvedSetIterator Result = 5897 getMostSpecialized(MatchesCopy.begin(), MatchesCopy.end(), 5898 TPOC_Other, From->getLocStart(), 5899 PDiag(), 5900 PDiag(diag::err_addr_ovl_ambiguous) 5901 << Matches[0].second->getDeclName(), 5902 PDiag(diag::note_ovl_candidate) 5903 << (unsigned) oc_function_template); 5904 assert(Result != MatchesCopy.end() && "no most-specialized template"); 5905 MarkDeclarationReferenced(From->getLocStart(), *Result); 5906 FoundResult = Matches[Result - MatchesCopy.begin()].first; 5907 if (Complain) { 5908 CheckUnresolvedAccess(*this, OvlExpr, FoundResult); 5909 DiagnoseUseOfDecl(FoundResult, OvlExpr->getNameLoc()); 5910 } 5911 return cast<FunctionDecl>(*Result); 5912 } 5913 5914 // [...] any function template specializations in the set are 5915 // eliminated if the set also contains a non-template function, [...] 5916 for (unsigned I = 0, N = Matches.size(); I != N; ) { 5917 if (Matches[I].second->getPrimaryTemplate() == 0) 5918 ++I; 5919 else { 5920 Matches[I] = Matches[--N]; 5921 Matches.set_size(N); 5922 } 5923 } 5924 5925 // [...] After such eliminations, if any, there shall remain exactly one 5926 // selected function. 5927 if (Matches.size() == 1) { 5928 MarkDeclarationReferenced(From->getLocStart(), Matches[0].second); 5929 FoundResult = Matches[0].first; 5930 if (Complain) { 5931 CheckUnresolvedAccess(*this, OvlExpr, Matches[0].first); 5932 DiagnoseUseOfDecl(Matches[0].first, OvlExpr->getNameLoc()); 5933 } 5934 return cast<FunctionDecl>(Matches[0].second); 5935 } 5936 5937 // FIXME: We should probably return the same thing that BestViableFunction 5938 // returns (even if we issue the diagnostics here). 5939 Diag(From->getLocStart(), diag::err_addr_ovl_ambiguous) 5940 << Matches[0].second->getDeclName(); 5941 for (unsigned I = 0, E = Matches.size(); I != E; ++I) 5942 NoteOverloadCandidate(Matches[I].second); 5943 return 0; 5944} 5945 5946/// \brief Given an expression that refers to an overloaded function, try to 5947/// resolve that overloaded function expression down to a single function. 5948/// 5949/// This routine can only resolve template-ids that refer to a single function 5950/// template, where that template-id refers to a single template whose template 5951/// arguments are either provided by the template-id or have defaults, 5952/// as described in C++0x [temp.arg.explicit]p3. 5953FunctionDecl *Sema::ResolveSingleFunctionTemplateSpecialization(Expr *From) { 5954 // C++ [over.over]p1: 5955 // [...] [Note: any redundant set of parentheses surrounding the 5956 // overloaded function name is ignored (5.1). ] 5957 // C++ [over.over]p1: 5958 // [...] The overloaded function name can be preceded by the & 5959 // operator. 5960 5961 if (From->getType() != Context.OverloadTy) 5962 return 0; 5963 5964 OverloadExpr *OvlExpr = OverloadExpr::find(From).getPointer(); 5965 5966 // If we didn't actually find any template-ids, we're done. 5967 if (!OvlExpr->hasExplicitTemplateArgs()) 5968 return 0; 5969 5970 TemplateArgumentListInfo ExplicitTemplateArgs; 5971 OvlExpr->getExplicitTemplateArgs().copyInto(ExplicitTemplateArgs); 5972 5973 // Look through all of the overloaded functions, searching for one 5974 // whose type matches exactly. 5975 FunctionDecl *Matched = 0; 5976 for (UnresolvedSetIterator I = OvlExpr->decls_begin(), 5977 E = OvlExpr->decls_end(); I != E; ++I) { 5978 // C++0x [temp.arg.explicit]p3: 5979 // [...] In contexts where deduction is done and fails, or in contexts 5980 // where deduction is not done, if a template argument list is 5981 // specified and it, along with any default template arguments, 5982 // identifies a single function template specialization, then the 5983 // template-id is an lvalue for the function template specialization. 5984 FunctionTemplateDecl *FunctionTemplate = cast<FunctionTemplateDecl>(*I); 5985 5986 // C++ [over.over]p2: 5987 // If the name is a function template, template argument deduction is 5988 // done (14.8.2.2), and if the argument deduction succeeds, the 5989 // resulting template argument list is used to generate a single 5990 // function template specialization, which is added to the set of 5991 // overloaded functions considered. 5992 FunctionDecl *Specialization = 0; 5993 TemplateDeductionInfo Info(Context, OvlExpr->getNameLoc()); 5994 if (TemplateDeductionResult Result 5995 = DeduceTemplateArguments(FunctionTemplate, &ExplicitTemplateArgs, 5996 Specialization, Info)) { 5997 // FIXME: make a note of the failed deduction for diagnostics. 5998 (void)Result; 5999 continue; 6000 } 6001 6002 // Multiple matches; we can't resolve to a single declaration. 6003 if (Matched) 6004 return 0; 6005 6006 Matched = Specialization; 6007 } 6008 6009 return Matched; 6010} 6011 6012/// \brief Add a single candidate to the overload set. 6013static void AddOverloadedCallCandidate(Sema &S, 6014 DeclAccessPair FoundDecl, 6015 const TemplateArgumentListInfo *ExplicitTemplateArgs, 6016 Expr **Args, unsigned NumArgs, 6017 OverloadCandidateSet &CandidateSet, 6018 bool PartialOverloading) { 6019 NamedDecl *Callee = FoundDecl.getDecl(); 6020 if (isa<UsingShadowDecl>(Callee)) 6021 Callee = cast<UsingShadowDecl>(Callee)->getTargetDecl(); 6022 6023 if (FunctionDecl *Func = dyn_cast<FunctionDecl>(Callee)) { 6024 assert(!ExplicitTemplateArgs && "Explicit template arguments?"); 6025 S.AddOverloadCandidate(Func, FoundDecl, Args, NumArgs, CandidateSet, 6026 false, PartialOverloading); 6027 return; 6028 } 6029 6030 if (FunctionTemplateDecl *FuncTemplate 6031 = dyn_cast<FunctionTemplateDecl>(Callee)) { 6032 S.AddTemplateOverloadCandidate(FuncTemplate, FoundDecl, 6033 ExplicitTemplateArgs, 6034 Args, NumArgs, CandidateSet); 6035 return; 6036 } 6037 6038 assert(false && "unhandled case in overloaded call candidate"); 6039 6040 // do nothing? 6041} 6042 6043/// \brief Add the overload candidates named by callee and/or found by argument 6044/// dependent lookup to the given overload set. 6045void Sema::AddOverloadedCallCandidates(UnresolvedLookupExpr *ULE, 6046 Expr **Args, unsigned NumArgs, 6047 OverloadCandidateSet &CandidateSet, 6048 bool PartialOverloading) { 6049 6050#ifndef NDEBUG 6051 // Verify that ArgumentDependentLookup is consistent with the rules 6052 // in C++0x [basic.lookup.argdep]p3: 6053 // 6054 // Let X be the lookup set produced by unqualified lookup (3.4.1) 6055 // and let Y be the lookup set produced by argument dependent 6056 // lookup (defined as follows). If X contains 6057 // 6058 // -- a declaration of a class member, or 6059 // 6060 // -- a block-scope function declaration that is not a 6061 // using-declaration, or 6062 // 6063 // -- a declaration that is neither a function or a function 6064 // template 6065 // 6066 // then Y is empty. 6067 6068 if (ULE->requiresADL()) { 6069 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(), 6070 E = ULE->decls_end(); I != E; ++I) { 6071 assert(!(*I)->getDeclContext()->isRecord()); 6072 assert(isa<UsingShadowDecl>(*I) || 6073 !(*I)->getDeclContext()->isFunctionOrMethod()); 6074 assert((*I)->getUnderlyingDecl()->isFunctionOrFunctionTemplate()); 6075 } 6076 } 6077#endif 6078 6079 // It would be nice to avoid this copy. 6080 TemplateArgumentListInfo TABuffer; 6081 const TemplateArgumentListInfo *ExplicitTemplateArgs = 0; 6082 if (ULE->hasExplicitTemplateArgs()) { 6083 ULE->copyTemplateArgumentsInto(TABuffer); 6084 ExplicitTemplateArgs = &TABuffer; 6085 } 6086 6087 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(), 6088 E = ULE->decls_end(); I != E; ++I) 6089 AddOverloadedCallCandidate(*this, I.getPair(), ExplicitTemplateArgs, 6090 Args, NumArgs, CandidateSet, 6091 PartialOverloading); 6092 6093 if (ULE->requiresADL()) 6094 AddArgumentDependentLookupCandidates(ULE->getName(), /*Operator*/ false, 6095 Args, NumArgs, 6096 ExplicitTemplateArgs, 6097 CandidateSet, 6098 PartialOverloading); 6099} 6100 6101static Sema::OwningExprResult Destroy(Sema &SemaRef, Expr *Fn, 6102 Expr **Args, unsigned NumArgs) { 6103 Fn->Destroy(SemaRef.Context); 6104 for (unsigned Arg = 0; Arg < NumArgs; ++Arg) 6105 Args[Arg]->Destroy(SemaRef.Context); 6106 return SemaRef.ExprError(); 6107} 6108 6109/// Attempts to recover from a call where no functions were found. 6110/// 6111/// Returns true if new candidates were found. 6112static Sema::OwningExprResult 6113BuildRecoveryCallExpr(Sema &SemaRef, Scope *S, Expr *Fn, 6114 UnresolvedLookupExpr *ULE, 6115 SourceLocation LParenLoc, 6116 Expr **Args, unsigned NumArgs, 6117 SourceLocation *CommaLocs, 6118 SourceLocation RParenLoc) { 6119 6120 CXXScopeSpec SS; 6121 if (ULE->getQualifier()) { 6122 SS.setScopeRep(ULE->getQualifier()); 6123 SS.setRange(ULE->getQualifierRange()); 6124 } 6125 6126 TemplateArgumentListInfo TABuffer; 6127 const TemplateArgumentListInfo *ExplicitTemplateArgs = 0; 6128 if (ULE->hasExplicitTemplateArgs()) { 6129 ULE->copyTemplateArgumentsInto(TABuffer); 6130 ExplicitTemplateArgs = &TABuffer; 6131 } 6132 6133 LookupResult R(SemaRef, ULE->getName(), ULE->getNameLoc(), 6134 Sema::LookupOrdinaryName); 6135 if (SemaRef.DiagnoseEmptyLookup(S, SS, R, Sema::CTC_Expression)) 6136 return Destroy(SemaRef, Fn, Args, NumArgs); 6137 6138 assert(!R.empty() && "lookup results empty despite recovery"); 6139 6140 // Build an implicit member call if appropriate. Just drop the 6141 // casts and such from the call, we don't really care. 6142 Sema::OwningExprResult NewFn = SemaRef.ExprError(); 6143 if ((*R.begin())->isCXXClassMember()) 6144 NewFn = SemaRef.BuildPossibleImplicitMemberExpr(SS, R, ExplicitTemplateArgs); 6145 else if (ExplicitTemplateArgs) 6146 NewFn = SemaRef.BuildTemplateIdExpr(SS, R, false, *ExplicitTemplateArgs); 6147 else 6148 NewFn = SemaRef.BuildDeclarationNameExpr(SS, R, false); 6149 6150 if (NewFn.isInvalid()) 6151 return Destroy(SemaRef, Fn, Args, NumArgs); 6152 6153 Fn->Destroy(SemaRef.Context); 6154 6155 // This shouldn't cause an infinite loop because we're giving it 6156 // an expression with non-empty lookup results, which should never 6157 // end up here. 6158 return SemaRef.ActOnCallExpr(/*Scope*/ 0, move(NewFn), LParenLoc, 6159 Sema::MultiExprArg(SemaRef, (void**) Args, NumArgs), 6160 CommaLocs, RParenLoc); 6161} 6162 6163/// ResolveOverloadedCallFn - Given the call expression that calls Fn 6164/// (which eventually refers to the declaration Func) and the call 6165/// arguments Args/NumArgs, attempt to resolve the function call down 6166/// to a specific function. If overload resolution succeeds, returns 6167/// the function declaration produced by overload 6168/// resolution. Otherwise, emits diagnostics, deletes all of the 6169/// arguments and Fn, and returns NULL. 6170Sema::OwningExprResult 6171Sema::BuildOverloadedCallExpr(Scope *S, Expr *Fn, UnresolvedLookupExpr *ULE, 6172 SourceLocation LParenLoc, 6173 Expr **Args, unsigned NumArgs, 6174 SourceLocation *CommaLocs, 6175 SourceLocation RParenLoc) { 6176#ifndef NDEBUG 6177 if (ULE->requiresADL()) { 6178 // To do ADL, we must have found an unqualified name. 6179 assert(!ULE->getQualifier() && "qualified name with ADL"); 6180 6181 // We don't perform ADL for implicit declarations of builtins. 6182 // Verify that this was correctly set up. 6183 FunctionDecl *F; 6184 if (ULE->decls_begin() + 1 == ULE->decls_end() && 6185 (F = dyn_cast<FunctionDecl>(*ULE->decls_begin())) && 6186 F->getBuiltinID() && F->isImplicit()) 6187 assert(0 && "performing ADL for builtin"); 6188 6189 // We don't perform ADL in C. 6190 assert(getLangOptions().CPlusPlus && "ADL enabled in C"); 6191 } 6192#endif 6193 6194 OverloadCandidateSet CandidateSet(Fn->getExprLoc()); 6195 6196 // Add the functions denoted by the callee to the set of candidate 6197 // functions, including those from argument-dependent lookup. 6198 AddOverloadedCallCandidates(ULE, Args, NumArgs, CandidateSet); 6199 6200 // If we found nothing, try to recover. 6201 // AddRecoveryCallCandidates diagnoses the error itself, so we just 6202 // bailout out if it fails. 6203 if (CandidateSet.empty()) 6204 return BuildRecoveryCallExpr(*this, S, Fn, ULE, LParenLoc, Args, NumArgs, 6205 CommaLocs, RParenLoc); 6206 6207 OverloadCandidateSet::iterator Best; 6208 switch (BestViableFunction(CandidateSet, Fn->getLocStart(), Best)) { 6209 case OR_Success: { 6210 FunctionDecl *FDecl = Best->Function; 6211 CheckUnresolvedLookupAccess(ULE, Best->FoundDecl); 6212 DiagnoseUseOfDecl(Best->FoundDecl, ULE->getNameLoc()); 6213 Fn = FixOverloadedFunctionReference(Fn, Best->FoundDecl, FDecl); 6214 return BuildResolvedCallExpr(Fn, FDecl, LParenLoc, Args, NumArgs, RParenLoc); 6215 } 6216 6217 case OR_No_Viable_Function: 6218 Diag(Fn->getSourceRange().getBegin(), 6219 diag::err_ovl_no_viable_function_in_call) 6220 << ULE->getName() << Fn->getSourceRange(); 6221 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6222 break; 6223 6224 case OR_Ambiguous: 6225 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_ambiguous_call) 6226 << ULE->getName() << Fn->getSourceRange(); 6227 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, NumArgs); 6228 break; 6229 6230 case OR_Deleted: 6231 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_deleted_call) 6232 << Best->Function->isDeleted() 6233 << ULE->getName() 6234 << Fn->getSourceRange(); 6235 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6236 break; 6237 } 6238 6239 // Overload resolution failed. Destroy all of the subexpressions and 6240 // return NULL. 6241 Fn->Destroy(Context); 6242 for (unsigned Arg = 0; Arg < NumArgs; ++Arg) 6243 Args[Arg]->Destroy(Context); 6244 return ExprError(); 6245} 6246 6247static bool IsOverloaded(const UnresolvedSetImpl &Functions) { 6248 return Functions.size() > 1 || 6249 (Functions.size() == 1 && isa<FunctionTemplateDecl>(*Functions.begin())); 6250} 6251 6252/// \brief Create a unary operation that may resolve to an overloaded 6253/// operator. 6254/// 6255/// \param OpLoc The location of the operator itself (e.g., '*'). 6256/// 6257/// \param OpcIn The UnaryOperator::Opcode that describes this 6258/// operator. 6259/// 6260/// \param Functions The set of non-member functions that will be 6261/// considered by overload resolution. The caller needs to build this 6262/// set based on the context using, e.g., 6263/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 6264/// set should not contain any member functions; those will be added 6265/// by CreateOverloadedUnaryOp(). 6266/// 6267/// \param input The input argument. 6268Sema::OwningExprResult 6269Sema::CreateOverloadedUnaryOp(SourceLocation OpLoc, unsigned OpcIn, 6270 const UnresolvedSetImpl &Fns, 6271 ExprArg input) { 6272 UnaryOperator::Opcode Opc = static_cast<UnaryOperator::Opcode>(OpcIn); 6273 Expr *Input = (Expr *)input.get(); 6274 6275 OverloadedOperatorKind Op = UnaryOperator::getOverloadedOperator(Opc); 6276 assert(Op != OO_None && "Invalid opcode for overloaded unary operator"); 6277 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 6278 6279 Expr *Args[2] = { Input, 0 }; 6280 unsigned NumArgs = 1; 6281 6282 // For post-increment and post-decrement, add the implicit '0' as 6283 // the second argument, so that we know this is a post-increment or 6284 // post-decrement. 6285 if (Opc == UnaryOperator::PostInc || Opc == UnaryOperator::PostDec) { 6286 llvm::APSInt Zero(Context.getTypeSize(Context.IntTy), false); 6287 Args[1] = new (Context) IntegerLiteral(Zero, Context.IntTy, 6288 SourceLocation()); 6289 NumArgs = 2; 6290 } 6291 6292 if (Input->isTypeDependent()) { 6293 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 6294 UnresolvedLookupExpr *Fn 6295 = UnresolvedLookupExpr::Create(Context, /*Dependent*/ true, NamingClass, 6296 0, SourceRange(), OpName, OpLoc, 6297 /*ADL*/ true, IsOverloaded(Fns), 6298 Fns.begin(), Fns.end()); 6299 input.release(); 6300 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 6301 &Args[0], NumArgs, 6302 Context.DependentTy, 6303 OpLoc)); 6304 } 6305 6306 // Build an empty overload set. 6307 OverloadCandidateSet CandidateSet(OpLoc); 6308 6309 // Add the candidates from the given function set. 6310 AddFunctionCandidates(Fns, &Args[0], NumArgs, CandidateSet, false); 6311 6312 // Add operator candidates that are member functions. 6313 AddMemberOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 6314 6315 // Add candidates from ADL. 6316 AddArgumentDependentLookupCandidates(OpName, /*Operator*/ true, 6317 Args, NumArgs, 6318 /*ExplicitTemplateArgs*/ 0, 6319 CandidateSet); 6320 6321 // Add builtin operator candidates. 6322 AddBuiltinOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 6323 6324 // Perform overload resolution. 6325 OverloadCandidateSet::iterator Best; 6326 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 6327 case OR_Success: { 6328 // We found a built-in operator or an overloaded operator. 6329 FunctionDecl *FnDecl = Best->Function; 6330 6331 if (FnDecl) { 6332 // We matched an overloaded operator. Build a call to that 6333 // operator. 6334 6335 // Convert the arguments. 6336 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 6337 CheckMemberOperatorAccess(OpLoc, Args[0], 0, Best->FoundDecl); 6338 6339 if (PerformObjectArgumentInitialization(Input, /*Qualifier=*/0, 6340 Best->FoundDecl, Method)) 6341 return ExprError(); 6342 } else { 6343 // Convert the arguments. 6344 OwningExprResult InputInit 6345 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 6346 FnDecl->getParamDecl(0)), 6347 SourceLocation(), 6348 move(input)); 6349 if (InputInit.isInvalid()) 6350 return ExprError(); 6351 6352 input = move(InputInit); 6353 Input = (Expr *)input.get(); 6354 } 6355 6356 DiagnoseUseOfDecl(Best->FoundDecl, OpLoc); 6357 6358 // Determine the result type 6359 QualType ResultTy = FnDecl->getResultType().getNonReferenceType(); 6360 6361 // Build the actual expression node. 6362 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 6363 SourceLocation()); 6364 UsualUnaryConversions(FnExpr); 6365 6366 input.release(); 6367 Args[0] = Input; 6368 ExprOwningPtr<CallExpr> TheCall(this, 6369 new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 6370 Args, NumArgs, ResultTy, OpLoc)); 6371 6372 if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall.get(), 6373 FnDecl)) 6374 return ExprError(); 6375 6376 return MaybeBindToTemporary(TheCall.release()); 6377 } else { 6378 // We matched a built-in operator. Convert the arguments, then 6379 // break out so that we will build the appropriate built-in 6380 // operator node. 6381 if (PerformImplicitConversion(Input, Best->BuiltinTypes.ParamTypes[0], 6382 Best->Conversions[0], AA_Passing)) 6383 return ExprError(); 6384 6385 break; 6386 } 6387 } 6388 6389 case OR_No_Viable_Function: 6390 // No viable function; fall through to handling this as a 6391 // built-in operator, which will produce an error message for us. 6392 break; 6393 6394 case OR_Ambiguous: 6395 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 6396 << UnaryOperator::getOpcodeStr(Opc) 6397 << Input->getSourceRange(); 6398 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, NumArgs, 6399 UnaryOperator::getOpcodeStr(Opc), OpLoc); 6400 return ExprError(); 6401 6402 case OR_Deleted: 6403 Diag(OpLoc, diag::err_ovl_deleted_oper) 6404 << Best->Function->isDeleted() 6405 << UnaryOperator::getOpcodeStr(Opc) 6406 << Input->getSourceRange(); 6407 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6408 return ExprError(); 6409 } 6410 6411 // Either we found no viable overloaded operator or we matched a 6412 // built-in operator. In either case, fall through to trying to 6413 // build a built-in operation. 6414 input.release(); 6415 return CreateBuiltinUnaryOp(OpLoc, Opc, Owned(Input)); 6416} 6417 6418/// \brief Create a binary operation that may resolve to an overloaded 6419/// operator. 6420/// 6421/// \param OpLoc The location of the operator itself (e.g., '+'). 6422/// 6423/// \param OpcIn The BinaryOperator::Opcode that describes this 6424/// operator. 6425/// 6426/// \param Functions The set of non-member functions that will be 6427/// considered by overload resolution. The caller needs to build this 6428/// set based on the context using, e.g., 6429/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 6430/// set should not contain any member functions; those will be added 6431/// by CreateOverloadedBinOp(). 6432/// 6433/// \param LHS Left-hand argument. 6434/// \param RHS Right-hand argument. 6435Sema::OwningExprResult 6436Sema::CreateOverloadedBinOp(SourceLocation OpLoc, 6437 unsigned OpcIn, 6438 const UnresolvedSetImpl &Fns, 6439 Expr *LHS, Expr *RHS) { 6440 Expr *Args[2] = { LHS, RHS }; 6441 LHS=RHS=0; //Please use only Args instead of LHS/RHS couple 6442 6443 BinaryOperator::Opcode Opc = static_cast<BinaryOperator::Opcode>(OpcIn); 6444 OverloadedOperatorKind Op = BinaryOperator::getOverloadedOperator(Opc); 6445 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 6446 6447 // If either side is type-dependent, create an appropriate dependent 6448 // expression. 6449 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 6450 if (Fns.empty()) { 6451 // If there are no functions to store, just build a dependent 6452 // BinaryOperator or CompoundAssignment. 6453 if (Opc <= BinaryOperator::Assign || Opc > BinaryOperator::OrAssign) 6454 return Owned(new (Context) BinaryOperator(Args[0], Args[1], Opc, 6455 Context.DependentTy, OpLoc)); 6456 6457 return Owned(new (Context) CompoundAssignOperator(Args[0], Args[1], Opc, 6458 Context.DependentTy, 6459 Context.DependentTy, 6460 Context.DependentTy, 6461 OpLoc)); 6462 } 6463 6464 // FIXME: save results of ADL from here? 6465 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 6466 UnresolvedLookupExpr *Fn 6467 = UnresolvedLookupExpr::Create(Context, /*Dependent*/ true, NamingClass, 6468 0, SourceRange(), OpName, OpLoc, 6469 /*ADL*/ true, IsOverloaded(Fns), 6470 Fns.begin(), Fns.end()); 6471 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 6472 Args, 2, 6473 Context.DependentTy, 6474 OpLoc)); 6475 } 6476 6477 // If this is the .* operator, which is not overloadable, just 6478 // create a built-in binary operator. 6479 if (Opc == BinaryOperator::PtrMemD) 6480 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 6481 6482 // If this is the assignment operator, we only perform overload resolution 6483 // if the left-hand side is a class or enumeration type. This is actually 6484 // a hack. The standard requires that we do overload resolution between the 6485 // various built-in candidates, but as DR507 points out, this can lead to 6486 // problems. So we do it this way, which pretty much follows what GCC does. 6487 // Note that we go the traditional code path for compound assignment forms. 6488 if (Opc==BinaryOperator::Assign && !Args[0]->getType()->isOverloadableType()) 6489 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 6490 6491 // Build an empty overload set. 6492 OverloadCandidateSet CandidateSet(OpLoc); 6493 6494 // Add the candidates from the given function set. 6495 AddFunctionCandidates(Fns, Args, 2, CandidateSet, false); 6496 6497 // Add operator candidates that are member functions. 6498 AddMemberOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 6499 6500 // Add candidates from ADL. 6501 AddArgumentDependentLookupCandidates(OpName, /*Operator*/ true, 6502 Args, 2, 6503 /*ExplicitTemplateArgs*/ 0, 6504 CandidateSet); 6505 6506 // Add builtin operator candidates. 6507 AddBuiltinOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 6508 6509 // Perform overload resolution. 6510 OverloadCandidateSet::iterator Best; 6511 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 6512 case OR_Success: { 6513 // We found a built-in operator or an overloaded operator. 6514 FunctionDecl *FnDecl = Best->Function; 6515 6516 if (FnDecl) { 6517 // We matched an overloaded operator. Build a call to that 6518 // operator. 6519 6520 // Convert the arguments. 6521 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 6522 // Best->Access is only meaningful for class members. 6523 CheckMemberOperatorAccess(OpLoc, Args[0], Args[1], Best->FoundDecl); 6524 6525 OwningExprResult Arg1 6526 = PerformCopyInitialization( 6527 InitializedEntity::InitializeParameter( 6528 FnDecl->getParamDecl(0)), 6529 SourceLocation(), 6530 Owned(Args[1])); 6531 if (Arg1.isInvalid()) 6532 return ExprError(); 6533 6534 if (PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/0, 6535 Best->FoundDecl, Method)) 6536 return ExprError(); 6537 6538 Args[1] = RHS = Arg1.takeAs<Expr>(); 6539 } else { 6540 // Convert the arguments. 6541 OwningExprResult Arg0 6542 = PerformCopyInitialization( 6543 InitializedEntity::InitializeParameter( 6544 FnDecl->getParamDecl(0)), 6545 SourceLocation(), 6546 Owned(Args[0])); 6547 if (Arg0.isInvalid()) 6548 return ExprError(); 6549 6550 OwningExprResult Arg1 6551 = PerformCopyInitialization( 6552 InitializedEntity::InitializeParameter( 6553 FnDecl->getParamDecl(1)), 6554 SourceLocation(), 6555 Owned(Args[1])); 6556 if (Arg1.isInvalid()) 6557 return ExprError(); 6558 Args[0] = LHS = Arg0.takeAs<Expr>(); 6559 Args[1] = RHS = Arg1.takeAs<Expr>(); 6560 } 6561 6562 DiagnoseUseOfDecl(Best->FoundDecl, OpLoc); 6563 6564 // Determine the result type 6565 QualType ResultTy 6566 = FnDecl->getType()->getAs<FunctionType>()->getResultType(); 6567 ResultTy = ResultTy.getNonReferenceType(); 6568 6569 // Build the actual expression node. 6570 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 6571 OpLoc); 6572 UsualUnaryConversions(FnExpr); 6573 6574 ExprOwningPtr<CXXOperatorCallExpr> 6575 TheCall(this, new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 6576 Args, 2, ResultTy, 6577 OpLoc)); 6578 6579 if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall.get(), 6580 FnDecl)) 6581 return ExprError(); 6582 6583 return MaybeBindToTemporary(TheCall.release()); 6584 } else { 6585 // We matched a built-in operator. Convert the arguments, then 6586 // break out so that we will build the appropriate built-in 6587 // operator node. 6588 if (PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 6589 Best->Conversions[0], AA_Passing) || 6590 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 6591 Best->Conversions[1], AA_Passing)) 6592 return ExprError(); 6593 6594 break; 6595 } 6596 } 6597 6598 case OR_No_Viable_Function: { 6599 // C++ [over.match.oper]p9: 6600 // If the operator is the operator , [...] and there are no 6601 // viable functions, then the operator is assumed to be the 6602 // built-in operator and interpreted according to clause 5. 6603 if (Opc == BinaryOperator::Comma) 6604 break; 6605 6606 // For class as left operand for assignment or compound assigment operator 6607 // do not fall through to handling in built-in, but report that no overloaded 6608 // assignment operator found 6609 OwningExprResult Result = ExprError(); 6610 if (Args[0]->getType()->isRecordType() && 6611 Opc >= BinaryOperator::Assign && Opc <= BinaryOperator::OrAssign) { 6612 Diag(OpLoc, diag::err_ovl_no_viable_oper) 6613 << BinaryOperator::getOpcodeStr(Opc) 6614 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 6615 } else { 6616 // No viable function; try to create a built-in operation, which will 6617 // produce an error. Then, show the non-viable candidates. 6618 Result = CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 6619 } 6620 assert(Result.isInvalid() && 6621 "C++ binary operator overloading is missing candidates!"); 6622 if (Result.isInvalid()) 6623 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2, 6624 BinaryOperator::getOpcodeStr(Opc), OpLoc); 6625 return move(Result); 6626 } 6627 6628 case OR_Ambiguous: 6629 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 6630 << BinaryOperator::getOpcodeStr(Opc) 6631 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 6632 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, 2, 6633 BinaryOperator::getOpcodeStr(Opc), OpLoc); 6634 return ExprError(); 6635 6636 case OR_Deleted: 6637 Diag(OpLoc, diag::err_ovl_deleted_oper) 6638 << Best->Function->isDeleted() 6639 << BinaryOperator::getOpcodeStr(Opc) 6640 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 6641 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2); 6642 return ExprError(); 6643 } 6644 6645 // We matched a built-in operator; build it. 6646 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 6647} 6648 6649Action::OwningExprResult 6650Sema::CreateOverloadedArraySubscriptExpr(SourceLocation LLoc, 6651 SourceLocation RLoc, 6652 ExprArg Base, ExprArg Idx) { 6653 Expr *Args[2] = { static_cast<Expr*>(Base.get()), 6654 static_cast<Expr*>(Idx.get()) }; 6655 DeclarationName OpName = 6656 Context.DeclarationNames.getCXXOperatorName(OO_Subscript); 6657 6658 // If either side is type-dependent, create an appropriate dependent 6659 // expression. 6660 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 6661 6662 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 6663 UnresolvedLookupExpr *Fn 6664 = UnresolvedLookupExpr::Create(Context, /*Dependent*/ true, NamingClass, 6665 0, SourceRange(), OpName, LLoc, 6666 /*ADL*/ true, /*Overloaded*/ false, 6667 UnresolvedSetIterator(), 6668 UnresolvedSetIterator()); 6669 // Can't add any actual overloads yet 6670 6671 Base.release(); 6672 Idx.release(); 6673 return Owned(new (Context) CXXOperatorCallExpr(Context, OO_Subscript, Fn, 6674 Args, 2, 6675 Context.DependentTy, 6676 RLoc)); 6677 } 6678 6679 // Build an empty overload set. 6680 OverloadCandidateSet CandidateSet(LLoc); 6681 6682 // Subscript can only be overloaded as a member function. 6683 6684 // Add operator candidates that are member functions. 6685 AddMemberOperatorCandidates(OO_Subscript, LLoc, Args, 2, CandidateSet); 6686 6687 // Add builtin operator candidates. 6688 AddBuiltinOperatorCandidates(OO_Subscript, LLoc, Args, 2, CandidateSet); 6689 6690 // Perform overload resolution. 6691 OverloadCandidateSet::iterator Best; 6692 switch (BestViableFunction(CandidateSet, LLoc, Best)) { 6693 case OR_Success: { 6694 // We found a built-in operator or an overloaded operator. 6695 FunctionDecl *FnDecl = Best->Function; 6696 6697 if (FnDecl) { 6698 // We matched an overloaded operator. Build a call to that 6699 // operator. 6700 6701 CheckMemberOperatorAccess(LLoc, Args[0], Args[1], Best->FoundDecl); 6702 DiagnoseUseOfDecl(Best->FoundDecl, LLoc); 6703 6704 // Convert the arguments. 6705 CXXMethodDecl *Method = cast<CXXMethodDecl>(FnDecl); 6706 if (PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/0, 6707 Best->FoundDecl, Method)) 6708 return ExprError(); 6709 6710 // Convert the arguments. 6711 OwningExprResult InputInit 6712 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 6713 FnDecl->getParamDecl(0)), 6714 SourceLocation(), 6715 Owned(Args[1])); 6716 if (InputInit.isInvalid()) 6717 return ExprError(); 6718 6719 Args[1] = InputInit.takeAs<Expr>(); 6720 6721 // Determine the result type 6722 QualType ResultTy 6723 = FnDecl->getType()->getAs<FunctionType>()->getResultType(); 6724 ResultTy = ResultTy.getNonReferenceType(); 6725 6726 // Build the actual expression node. 6727 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 6728 LLoc); 6729 UsualUnaryConversions(FnExpr); 6730 6731 Base.release(); 6732 Idx.release(); 6733 ExprOwningPtr<CXXOperatorCallExpr> 6734 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Subscript, 6735 FnExpr, Args, 2, 6736 ResultTy, RLoc)); 6737 6738 if (CheckCallReturnType(FnDecl->getResultType(), LLoc, TheCall.get(), 6739 FnDecl)) 6740 return ExprError(); 6741 6742 return MaybeBindToTemporary(TheCall.release()); 6743 } else { 6744 // We matched a built-in operator. Convert the arguments, then 6745 // break out so that we will build the appropriate built-in 6746 // operator node. 6747 if (PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 6748 Best->Conversions[0], AA_Passing) || 6749 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 6750 Best->Conversions[1], AA_Passing)) 6751 return ExprError(); 6752 6753 break; 6754 } 6755 } 6756 6757 case OR_No_Viable_Function: { 6758 if (CandidateSet.empty()) 6759 Diag(LLoc, diag::err_ovl_no_oper) 6760 << Args[0]->getType() << /*subscript*/ 0 6761 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 6762 else 6763 Diag(LLoc, diag::err_ovl_no_viable_subscript) 6764 << Args[0]->getType() 6765 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 6766 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2, 6767 "[]", LLoc); 6768 return ExprError(); 6769 } 6770 6771 case OR_Ambiguous: 6772 Diag(LLoc, diag::err_ovl_ambiguous_oper) 6773 << "[]" << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 6774 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, 2, 6775 "[]", LLoc); 6776 return ExprError(); 6777 6778 case OR_Deleted: 6779 Diag(LLoc, diag::err_ovl_deleted_oper) 6780 << Best->Function->isDeleted() << "[]" 6781 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 6782 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2, 6783 "[]", LLoc); 6784 return ExprError(); 6785 } 6786 6787 // We matched a built-in operator; build it. 6788 Base.release(); 6789 Idx.release(); 6790 return CreateBuiltinArraySubscriptExpr(Owned(Args[0]), LLoc, 6791 Owned(Args[1]), RLoc); 6792} 6793 6794/// BuildCallToMemberFunction - Build a call to a member 6795/// function. MemExpr is the expression that refers to the member 6796/// function (and includes the object parameter), Args/NumArgs are the 6797/// arguments to the function call (not including the object 6798/// parameter). The caller needs to validate that the member 6799/// expression refers to a member function or an overloaded member 6800/// function. 6801Sema::OwningExprResult 6802Sema::BuildCallToMemberFunction(Scope *S, Expr *MemExprE, 6803 SourceLocation LParenLoc, Expr **Args, 6804 unsigned NumArgs, SourceLocation *CommaLocs, 6805 SourceLocation RParenLoc) { 6806 // Dig out the member expression. This holds both the object 6807 // argument and the member function we're referring to. 6808 Expr *NakedMemExpr = MemExprE->IgnoreParens(); 6809 6810 MemberExpr *MemExpr; 6811 CXXMethodDecl *Method = 0; 6812 DeclAccessPair FoundDecl = DeclAccessPair::make(0, AS_public); 6813 NestedNameSpecifier *Qualifier = 0; 6814 if (isa<MemberExpr>(NakedMemExpr)) { 6815 MemExpr = cast<MemberExpr>(NakedMemExpr); 6816 Method = cast<CXXMethodDecl>(MemExpr->getMemberDecl()); 6817 FoundDecl = MemExpr->getFoundDecl(); 6818 Qualifier = MemExpr->getQualifier(); 6819 } else { 6820 UnresolvedMemberExpr *UnresExpr = cast<UnresolvedMemberExpr>(NakedMemExpr); 6821 Qualifier = UnresExpr->getQualifier(); 6822 6823 QualType ObjectType = UnresExpr->getBaseType(); 6824 6825 // Add overload candidates 6826 OverloadCandidateSet CandidateSet(UnresExpr->getMemberLoc()); 6827 6828 // FIXME: avoid copy. 6829 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 6830 if (UnresExpr->hasExplicitTemplateArgs()) { 6831 UnresExpr->copyTemplateArgumentsInto(TemplateArgsBuffer); 6832 TemplateArgs = &TemplateArgsBuffer; 6833 } 6834 6835 for (UnresolvedMemberExpr::decls_iterator I = UnresExpr->decls_begin(), 6836 E = UnresExpr->decls_end(); I != E; ++I) { 6837 6838 NamedDecl *Func = *I; 6839 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(Func->getDeclContext()); 6840 if (isa<UsingShadowDecl>(Func)) 6841 Func = cast<UsingShadowDecl>(Func)->getTargetDecl(); 6842 6843 if ((Method = dyn_cast<CXXMethodDecl>(Func))) { 6844 // If explicit template arguments were provided, we can't call a 6845 // non-template member function. 6846 if (TemplateArgs) 6847 continue; 6848 6849 AddMethodCandidate(Method, I.getPair(), ActingDC, ObjectType, 6850 Args, NumArgs, 6851 CandidateSet, /*SuppressUserConversions=*/false); 6852 } else { 6853 AddMethodTemplateCandidate(cast<FunctionTemplateDecl>(Func), 6854 I.getPair(), ActingDC, TemplateArgs, 6855 ObjectType, Args, NumArgs, 6856 CandidateSet, 6857 /*SuppressUsedConversions=*/false); 6858 } 6859 } 6860 6861 DeclarationName DeclName = UnresExpr->getMemberName(); 6862 6863 OverloadCandidateSet::iterator Best; 6864 switch (BestViableFunction(CandidateSet, UnresExpr->getLocStart(), Best)) { 6865 case OR_Success: 6866 Method = cast<CXXMethodDecl>(Best->Function); 6867 FoundDecl = Best->FoundDecl; 6868 CheckUnresolvedMemberAccess(UnresExpr, Best->FoundDecl); 6869 DiagnoseUseOfDecl(Best->FoundDecl, UnresExpr->getNameLoc()); 6870 break; 6871 6872 case OR_No_Viable_Function: 6873 Diag(UnresExpr->getMemberLoc(), 6874 diag::err_ovl_no_viable_member_function_in_call) 6875 << DeclName << MemExprE->getSourceRange(); 6876 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6877 // FIXME: Leaking incoming expressions! 6878 return ExprError(); 6879 6880 case OR_Ambiguous: 6881 Diag(UnresExpr->getMemberLoc(), diag::err_ovl_ambiguous_member_call) 6882 << DeclName << MemExprE->getSourceRange(); 6883 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6884 // FIXME: Leaking incoming expressions! 6885 return ExprError(); 6886 6887 case OR_Deleted: 6888 Diag(UnresExpr->getMemberLoc(), diag::err_ovl_deleted_member_call) 6889 << Best->Function->isDeleted() 6890 << DeclName << MemExprE->getSourceRange(); 6891 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6892 // FIXME: Leaking incoming expressions! 6893 return ExprError(); 6894 } 6895 6896 MemExprE = FixOverloadedFunctionReference(MemExprE, FoundDecl, Method); 6897 6898 // If overload resolution picked a static member, build a 6899 // non-member call based on that function. 6900 if (Method->isStatic()) { 6901 return BuildResolvedCallExpr(MemExprE, Method, LParenLoc, 6902 Args, NumArgs, RParenLoc); 6903 } 6904 6905 MemExpr = cast<MemberExpr>(MemExprE->IgnoreParens()); 6906 } 6907 6908 assert(Method && "Member call to something that isn't a method?"); 6909 ExprOwningPtr<CXXMemberCallExpr> 6910 TheCall(this, new (Context) CXXMemberCallExpr(Context, MemExprE, Args, 6911 NumArgs, 6912 Method->getResultType().getNonReferenceType(), 6913 RParenLoc)); 6914 6915 // Check for a valid return type. 6916 if (CheckCallReturnType(Method->getResultType(), MemExpr->getMemberLoc(), 6917 TheCall.get(), Method)) 6918 return ExprError(); 6919 6920 // Convert the object argument (for a non-static member function call). 6921 // We only need to do this if there was actually an overload; otherwise 6922 // it was done at lookup. 6923 Expr *ObjectArg = MemExpr->getBase(); 6924 if (!Method->isStatic() && 6925 PerformObjectArgumentInitialization(ObjectArg, Qualifier, 6926 FoundDecl, Method)) 6927 return ExprError(); 6928 MemExpr->setBase(ObjectArg); 6929 6930 // Convert the rest of the arguments 6931 const FunctionProtoType *Proto = Method->getType()->getAs<FunctionProtoType>(); 6932 if (ConvertArgumentsForCall(&*TheCall, MemExpr, Method, Proto, Args, NumArgs, 6933 RParenLoc)) 6934 return ExprError(); 6935 6936 if (CheckFunctionCall(Method, TheCall.get())) 6937 return ExprError(); 6938 6939 return MaybeBindToTemporary(TheCall.release()); 6940} 6941 6942/// BuildCallToObjectOfClassType - Build a call to an object of class 6943/// type (C++ [over.call.object]), which can end up invoking an 6944/// overloaded function call operator (@c operator()) or performing a 6945/// user-defined conversion on the object argument. 6946Sema::ExprResult 6947Sema::BuildCallToObjectOfClassType(Scope *S, Expr *Object, 6948 SourceLocation LParenLoc, 6949 Expr **Args, unsigned NumArgs, 6950 SourceLocation *CommaLocs, 6951 SourceLocation RParenLoc) { 6952 assert(Object->getType()->isRecordType() && "Requires object type argument"); 6953 const RecordType *Record = Object->getType()->getAs<RecordType>(); 6954 6955 // C++ [over.call.object]p1: 6956 // If the primary-expression E in the function call syntax 6957 // evaluates to a class object of type "cv T", then the set of 6958 // candidate functions includes at least the function call 6959 // operators of T. The function call operators of T are obtained by 6960 // ordinary lookup of the name operator() in the context of 6961 // (E).operator(). 6962 OverloadCandidateSet CandidateSet(LParenLoc); 6963 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Call); 6964 6965 if (RequireCompleteType(LParenLoc, Object->getType(), 6966 PDiag(diag::err_incomplete_object_call) 6967 << Object->getSourceRange())) 6968 return true; 6969 6970 LookupResult R(*this, OpName, LParenLoc, LookupOrdinaryName); 6971 LookupQualifiedName(R, Record->getDecl()); 6972 R.suppressDiagnostics(); 6973 6974 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 6975 Oper != OperEnd; ++Oper) { 6976 AddMethodCandidate(Oper.getPair(), Object->getType(), 6977 Args, NumArgs, CandidateSet, 6978 /*SuppressUserConversions=*/ false); 6979 } 6980 6981 // C++ [over.call.object]p2: 6982 // In addition, for each conversion function declared in T of the 6983 // form 6984 // 6985 // operator conversion-type-id () cv-qualifier; 6986 // 6987 // where cv-qualifier is the same cv-qualification as, or a 6988 // greater cv-qualification than, cv, and where conversion-type-id 6989 // denotes the type "pointer to function of (P1,...,Pn) returning 6990 // R", or the type "reference to pointer to function of 6991 // (P1,...,Pn) returning R", or the type "reference to function 6992 // of (P1,...,Pn) returning R", a surrogate call function [...] 6993 // is also considered as a candidate function. Similarly, 6994 // surrogate call functions are added to the set of candidate 6995 // functions for each conversion function declared in an 6996 // accessible base class provided the function is not hidden 6997 // within T by another intervening declaration. 6998 const UnresolvedSetImpl *Conversions 6999 = cast<CXXRecordDecl>(Record->getDecl())->getVisibleConversionFunctions(); 7000 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 7001 E = Conversions->end(); I != E; ++I) { 7002 NamedDecl *D = *I; 7003 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext()); 7004 if (isa<UsingShadowDecl>(D)) 7005 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 7006 7007 // Skip over templated conversion functions; they aren't 7008 // surrogates. 7009 if (isa<FunctionTemplateDecl>(D)) 7010 continue; 7011 7012 CXXConversionDecl *Conv = cast<CXXConversionDecl>(D); 7013 7014 // Strip the reference type (if any) and then the pointer type (if 7015 // any) to get down to what might be a function type. 7016 QualType ConvType = Conv->getConversionType().getNonReferenceType(); 7017 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 7018 ConvType = ConvPtrType->getPointeeType(); 7019 7020 if (const FunctionProtoType *Proto = ConvType->getAs<FunctionProtoType>()) 7021 AddSurrogateCandidate(Conv, I.getPair(), ActingContext, Proto, 7022 Object->getType(), Args, NumArgs, 7023 CandidateSet); 7024 } 7025 7026 // Perform overload resolution. 7027 OverloadCandidateSet::iterator Best; 7028 switch (BestViableFunction(CandidateSet, Object->getLocStart(), Best)) { 7029 case OR_Success: 7030 // Overload resolution succeeded; we'll build the appropriate call 7031 // below. 7032 break; 7033 7034 case OR_No_Viable_Function: 7035 if (CandidateSet.empty()) 7036 Diag(Object->getSourceRange().getBegin(), diag::err_ovl_no_oper) 7037 << Object->getType() << /*call*/ 1 7038 << Object->getSourceRange(); 7039 else 7040 Diag(Object->getSourceRange().getBegin(), 7041 diag::err_ovl_no_viable_object_call) 7042 << Object->getType() << Object->getSourceRange(); 7043 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 7044 break; 7045 7046 case OR_Ambiguous: 7047 Diag(Object->getSourceRange().getBegin(), 7048 diag::err_ovl_ambiguous_object_call) 7049 << Object->getType() << Object->getSourceRange(); 7050 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, NumArgs); 7051 break; 7052 7053 case OR_Deleted: 7054 Diag(Object->getSourceRange().getBegin(), 7055 diag::err_ovl_deleted_object_call) 7056 << Best->Function->isDeleted() 7057 << Object->getType() << Object->getSourceRange(); 7058 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 7059 break; 7060 } 7061 7062 if (Best == CandidateSet.end()) { 7063 // We had an error; delete all of the subexpressions and return 7064 // the error. 7065 Object->Destroy(Context); 7066 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 7067 Args[ArgIdx]->Destroy(Context); 7068 return true; 7069 } 7070 7071 if (Best->Function == 0) { 7072 // Since there is no function declaration, this is one of the 7073 // surrogate candidates. Dig out the conversion function. 7074 CXXConversionDecl *Conv 7075 = cast<CXXConversionDecl>( 7076 Best->Conversions[0].UserDefined.ConversionFunction); 7077 7078 CheckMemberOperatorAccess(LParenLoc, Object, 0, Best->FoundDecl); 7079 DiagnoseUseOfDecl(Best->FoundDecl, LParenLoc); 7080 7081 // We selected one of the surrogate functions that converts the 7082 // object parameter to a function pointer. Perform the conversion 7083 // on the object argument, then let ActOnCallExpr finish the job. 7084 7085 // Create an implicit member expr to refer to the conversion operator. 7086 // and then call it. 7087 CXXMemberCallExpr *CE = BuildCXXMemberCallExpr(Object, Best->FoundDecl, 7088 Conv); 7089 7090 return ActOnCallExpr(S, ExprArg(*this, CE), LParenLoc, 7091 MultiExprArg(*this, (ExprTy**)Args, NumArgs), 7092 CommaLocs, RParenLoc).result(); 7093 } 7094 7095 CheckMemberOperatorAccess(LParenLoc, Object, 0, Best->FoundDecl); 7096 DiagnoseUseOfDecl(Best->FoundDecl, LParenLoc); 7097 7098 // We found an overloaded operator(). Build a CXXOperatorCallExpr 7099 // that calls this method, using Object for the implicit object 7100 // parameter and passing along the remaining arguments. 7101 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 7102 const FunctionProtoType *Proto = Method->getType()->getAs<FunctionProtoType>(); 7103 7104 unsigned NumArgsInProto = Proto->getNumArgs(); 7105 unsigned NumArgsToCheck = NumArgs; 7106 7107 // Build the full argument list for the method call (the 7108 // implicit object parameter is placed at the beginning of the 7109 // list). 7110 Expr **MethodArgs; 7111 if (NumArgs < NumArgsInProto) { 7112 NumArgsToCheck = NumArgsInProto; 7113 MethodArgs = new Expr*[NumArgsInProto + 1]; 7114 } else { 7115 MethodArgs = new Expr*[NumArgs + 1]; 7116 } 7117 MethodArgs[0] = Object; 7118 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 7119 MethodArgs[ArgIdx + 1] = Args[ArgIdx]; 7120 7121 Expr *NewFn = new (Context) DeclRefExpr(Method, Method->getType(), 7122 SourceLocation()); 7123 UsualUnaryConversions(NewFn); 7124 7125 // Once we've built TheCall, all of the expressions are properly 7126 // owned. 7127 QualType ResultTy = Method->getResultType().getNonReferenceType(); 7128 ExprOwningPtr<CXXOperatorCallExpr> 7129 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Call, NewFn, 7130 MethodArgs, NumArgs + 1, 7131 ResultTy, RParenLoc)); 7132 delete [] MethodArgs; 7133 7134 if (CheckCallReturnType(Method->getResultType(), LParenLoc, TheCall.get(), 7135 Method)) 7136 return true; 7137 7138 // We may have default arguments. If so, we need to allocate more 7139 // slots in the call for them. 7140 if (NumArgs < NumArgsInProto) 7141 TheCall->setNumArgs(Context, NumArgsInProto + 1); 7142 else if (NumArgs > NumArgsInProto) 7143 NumArgsToCheck = NumArgsInProto; 7144 7145 bool IsError = false; 7146 7147 // Initialize the implicit object parameter. 7148 IsError |= PerformObjectArgumentInitialization(Object, /*Qualifier=*/0, 7149 Best->FoundDecl, Method); 7150 TheCall->setArg(0, Object); 7151 7152 7153 // Check the argument types. 7154 for (unsigned i = 0; i != NumArgsToCheck; i++) { 7155 Expr *Arg; 7156 if (i < NumArgs) { 7157 Arg = Args[i]; 7158 7159 // Pass the argument. 7160 7161 OwningExprResult InputInit 7162 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 7163 Method->getParamDecl(i)), 7164 SourceLocation(), Owned(Arg)); 7165 7166 IsError |= InputInit.isInvalid(); 7167 Arg = InputInit.takeAs<Expr>(); 7168 } else { 7169 OwningExprResult DefArg 7170 = BuildCXXDefaultArgExpr(LParenLoc, Method, Method->getParamDecl(i)); 7171 if (DefArg.isInvalid()) { 7172 IsError = true; 7173 break; 7174 } 7175 7176 Arg = DefArg.takeAs<Expr>(); 7177 } 7178 7179 TheCall->setArg(i + 1, Arg); 7180 } 7181 7182 // If this is a variadic call, handle args passed through "...". 7183 if (Proto->isVariadic()) { 7184 // Promote the arguments (C99 6.5.2.2p7). 7185 for (unsigned i = NumArgsInProto; i != NumArgs; i++) { 7186 Expr *Arg = Args[i]; 7187 IsError |= DefaultVariadicArgumentPromotion(Arg, VariadicMethod, 0); 7188 TheCall->setArg(i + 1, Arg); 7189 } 7190 } 7191 7192 if (IsError) return true; 7193 7194 if (CheckFunctionCall(Method, TheCall.get())) 7195 return true; 7196 7197 return MaybeBindToTemporary(TheCall.release()).result(); 7198} 7199 7200/// BuildOverloadedArrowExpr - Build a call to an overloaded @c operator-> 7201/// (if one exists), where @c Base is an expression of class type and 7202/// @c Member is the name of the member we're trying to find. 7203Sema::OwningExprResult 7204Sema::BuildOverloadedArrowExpr(Scope *S, ExprArg BaseIn, SourceLocation OpLoc) { 7205 Expr *Base = static_cast<Expr *>(BaseIn.get()); 7206 assert(Base->getType()->isRecordType() && "left-hand side must have class type"); 7207 7208 SourceLocation Loc = Base->getExprLoc(); 7209 7210 // C++ [over.ref]p1: 7211 // 7212 // [...] An expression x->m is interpreted as (x.operator->())->m 7213 // for a class object x of type T if T::operator->() exists and if 7214 // the operator is selected as the best match function by the 7215 // overload resolution mechanism (13.3). 7216 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Arrow); 7217 OverloadCandidateSet CandidateSet(Loc); 7218 const RecordType *BaseRecord = Base->getType()->getAs<RecordType>(); 7219 7220 if (RequireCompleteType(Loc, Base->getType(), 7221 PDiag(diag::err_typecheck_incomplete_tag) 7222 << Base->getSourceRange())) 7223 return ExprError(); 7224 7225 LookupResult R(*this, OpName, OpLoc, LookupOrdinaryName); 7226 LookupQualifiedName(R, BaseRecord->getDecl()); 7227 R.suppressDiagnostics(); 7228 7229 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 7230 Oper != OperEnd; ++Oper) { 7231 AddMethodCandidate(Oper.getPair(), Base->getType(), 0, 0, CandidateSet, 7232 /*SuppressUserConversions=*/false); 7233 } 7234 7235 // Perform overload resolution. 7236 OverloadCandidateSet::iterator Best; 7237 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 7238 case OR_Success: 7239 // Overload resolution succeeded; we'll build the call below. 7240 break; 7241 7242 case OR_No_Viable_Function: 7243 if (CandidateSet.empty()) 7244 Diag(OpLoc, diag::err_typecheck_member_reference_arrow) 7245 << Base->getType() << Base->getSourceRange(); 7246 else 7247 Diag(OpLoc, diag::err_ovl_no_viable_oper) 7248 << "operator->" << Base->getSourceRange(); 7249 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, &Base, 1); 7250 return ExprError(); 7251 7252 case OR_Ambiguous: 7253 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 7254 << "->" << Base->getSourceRange(); 7255 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, &Base, 1); 7256 return ExprError(); 7257 7258 case OR_Deleted: 7259 Diag(OpLoc, diag::err_ovl_deleted_oper) 7260 << Best->Function->isDeleted() 7261 << "->" << Base->getSourceRange(); 7262 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, &Base, 1); 7263 return ExprError(); 7264 } 7265 7266 CheckMemberOperatorAccess(OpLoc, Base, 0, Best->FoundDecl); 7267 DiagnoseUseOfDecl(Best->FoundDecl, OpLoc); 7268 7269 // Convert the object parameter. 7270 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 7271 if (PerformObjectArgumentInitialization(Base, /*Qualifier=*/0, 7272 Best->FoundDecl, Method)) 7273 return ExprError(); 7274 7275 // No concerns about early exits now. 7276 BaseIn.release(); 7277 7278 // Build the operator call. 7279 Expr *FnExpr = new (Context) DeclRefExpr(Method, Method->getType(), 7280 SourceLocation()); 7281 UsualUnaryConversions(FnExpr); 7282 7283 QualType ResultTy = Method->getResultType().getNonReferenceType(); 7284 ExprOwningPtr<CXXOperatorCallExpr> 7285 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Arrow, FnExpr, 7286 &Base, 1, ResultTy, OpLoc)); 7287 7288 if (CheckCallReturnType(Method->getResultType(), OpLoc, TheCall.get(), 7289 Method)) 7290 return ExprError(); 7291 return move(TheCall); 7292} 7293 7294/// FixOverloadedFunctionReference - E is an expression that refers to 7295/// a C++ overloaded function (possibly with some parentheses and 7296/// perhaps a '&' around it). We have resolved the overloaded function 7297/// to the function declaration Fn, so patch up the expression E to 7298/// refer (possibly indirectly) to Fn. Returns the new expr. 7299Expr *Sema::FixOverloadedFunctionReference(Expr *E, DeclAccessPair Found, 7300 FunctionDecl *Fn) { 7301 if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) { 7302 Expr *SubExpr = FixOverloadedFunctionReference(PE->getSubExpr(), 7303 Found, Fn); 7304 if (SubExpr == PE->getSubExpr()) 7305 return PE->Retain(); 7306 7307 return new (Context) ParenExpr(PE->getLParen(), PE->getRParen(), SubExpr); 7308 } 7309 7310 if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) { 7311 Expr *SubExpr = FixOverloadedFunctionReference(ICE->getSubExpr(), 7312 Found, Fn); 7313 assert(Context.hasSameType(ICE->getSubExpr()->getType(), 7314 SubExpr->getType()) && 7315 "Implicit cast type cannot be determined from overload"); 7316 if (SubExpr == ICE->getSubExpr()) 7317 return ICE->Retain(); 7318 7319 return new (Context) ImplicitCastExpr(ICE->getType(), 7320 ICE->getCastKind(), 7321 SubExpr, CXXBaseSpecifierArray(), 7322 ICE->isLvalueCast()); 7323 } 7324 7325 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(E)) { 7326 assert(UnOp->getOpcode() == UnaryOperator::AddrOf && 7327 "Can only take the address of an overloaded function"); 7328 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 7329 if (Method->isStatic()) { 7330 // Do nothing: static member functions aren't any different 7331 // from non-member functions. 7332 } else { 7333 // Fix the sub expression, which really has to be an 7334 // UnresolvedLookupExpr holding an overloaded member function 7335 // or template. 7336 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(), 7337 Found, Fn); 7338 if (SubExpr == UnOp->getSubExpr()) 7339 return UnOp->Retain(); 7340 7341 assert(isa<DeclRefExpr>(SubExpr) 7342 && "fixed to something other than a decl ref"); 7343 assert(cast<DeclRefExpr>(SubExpr)->getQualifier() 7344 && "fixed to a member ref with no nested name qualifier"); 7345 7346 // We have taken the address of a pointer to member 7347 // function. Perform the computation here so that we get the 7348 // appropriate pointer to member type. 7349 QualType ClassType 7350 = Context.getTypeDeclType(cast<RecordDecl>(Method->getDeclContext())); 7351 QualType MemPtrType 7352 = Context.getMemberPointerType(Fn->getType(), ClassType.getTypePtr()); 7353 7354 return new (Context) UnaryOperator(SubExpr, UnaryOperator::AddrOf, 7355 MemPtrType, UnOp->getOperatorLoc()); 7356 } 7357 } 7358 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(), 7359 Found, Fn); 7360 if (SubExpr == UnOp->getSubExpr()) 7361 return UnOp->Retain(); 7362 7363 return new (Context) UnaryOperator(SubExpr, UnaryOperator::AddrOf, 7364 Context.getPointerType(SubExpr->getType()), 7365 UnOp->getOperatorLoc()); 7366 } 7367 7368 if (UnresolvedLookupExpr *ULE = dyn_cast<UnresolvedLookupExpr>(E)) { 7369 // FIXME: avoid copy. 7370 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 7371 if (ULE->hasExplicitTemplateArgs()) { 7372 ULE->copyTemplateArgumentsInto(TemplateArgsBuffer); 7373 TemplateArgs = &TemplateArgsBuffer; 7374 } 7375 7376 return DeclRefExpr::Create(Context, 7377 ULE->getQualifier(), 7378 ULE->getQualifierRange(), 7379 Fn, 7380 ULE->getNameLoc(), 7381 Fn->getType(), 7382 TemplateArgs); 7383 } 7384 7385 if (UnresolvedMemberExpr *MemExpr = dyn_cast<UnresolvedMemberExpr>(E)) { 7386 // FIXME: avoid copy. 7387 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 7388 if (MemExpr->hasExplicitTemplateArgs()) { 7389 MemExpr->copyTemplateArgumentsInto(TemplateArgsBuffer); 7390 TemplateArgs = &TemplateArgsBuffer; 7391 } 7392 7393 Expr *Base; 7394 7395 // If we're filling in 7396 if (MemExpr->isImplicitAccess()) { 7397 if (cast<CXXMethodDecl>(Fn)->isStatic()) { 7398 return DeclRefExpr::Create(Context, 7399 MemExpr->getQualifier(), 7400 MemExpr->getQualifierRange(), 7401 Fn, 7402 MemExpr->getMemberLoc(), 7403 Fn->getType(), 7404 TemplateArgs); 7405 } else { 7406 SourceLocation Loc = MemExpr->getMemberLoc(); 7407 if (MemExpr->getQualifier()) 7408 Loc = MemExpr->getQualifierRange().getBegin(); 7409 Base = new (Context) CXXThisExpr(Loc, 7410 MemExpr->getBaseType(), 7411 /*isImplicit=*/true); 7412 } 7413 } else 7414 Base = MemExpr->getBase()->Retain(); 7415 7416 return MemberExpr::Create(Context, Base, 7417 MemExpr->isArrow(), 7418 MemExpr->getQualifier(), 7419 MemExpr->getQualifierRange(), 7420 Fn, 7421 Found, 7422 MemExpr->getMemberLoc(), 7423 TemplateArgs, 7424 Fn->getType()); 7425 } 7426 7427 assert(false && "Invalid reference to overloaded function"); 7428 return E->Retain(); 7429} 7430 7431Sema::OwningExprResult Sema::FixOverloadedFunctionReference(OwningExprResult E, 7432 DeclAccessPair Found, 7433 FunctionDecl *Fn) { 7434 return Owned(FixOverloadedFunctionReference((Expr *)E.get(), Found, Fn)); 7435} 7436 7437} // end namespace clang 7438