SemaOverload.cpp revision 57e97786433e70197a089360228d8f0d82e3ad4c
1//===--- SemaOverload.cpp - C++ Overloading ---------------------*- C++ -*-===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This file provides Sema routines for C++ overloading. 11// 12//===----------------------------------------------------------------------===// 13 14#include "Sema.h" 15#include "Lookup.h" 16#include "SemaInit.h" 17#include "clang/Basic/Diagnostic.h" 18#include "clang/Lex/Preprocessor.h" 19#include "clang/AST/ASTContext.h" 20#include "clang/AST/CXXInheritance.h" 21#include "clang/AST/Expr.h" 22#include "clang/AST/ExprCXX.h" 23#include "clang/AST/TypeOrdering.h" 24#include "clang/Basic/PartialDiagnostic.h" 25#include "llvm/ADT/SmallPtrSet.h" 26#include "llvm/ADT/STLExtras.h" 27#include <algorithm> 28 29namespace clang { 30 31/// GetConversionCategory - Retrieve the implicit conversion 32/// category corresponding to the given implicit conversion kind. 33ImplicitConversionCategory 34GetConversionCategory(ImplicitConversionKind Kind) { 35 static const ImplicitConversionCategory 36 Category[(int)ICK_Num_Conversion_Kinds] = { 37 ICC_Identity, 38 ICC_Lvalue_Transformation, 39 ICC_Lvalue_Transformation, 40 ICC_Lvalue_Transformation, 41 ICC_Identity, 42 ICC_Qualification_Adjustment, 43 ICC_Promotion, 44 ICC_Promotion, 45 ICC_Promotion, 46 ICC_Conversion, 47 ICC_Conversion, 48 ICC_Conversion, 49 ICC_Conversion, 50 ICC_Conversion, 51 ICC_Conversion, 52 ICC_Conversion, 53 ICC_Conversion, 54 ICC_Conversion, 55 ICC_Conversion, 56 ICC_Conversion, 57 ICC_Conversion 58 }; 59 return Category[(int)Kind]; 60} 61 62/// GetConversionRank - Retrieve the implicit conversion rank 63/// corresponding to the given implicit conversion kind. 64ImplicitConversionRank GetConversionRank(ImplicitConversionKind Kind) { 65 static const ImplicitConversionRank 66 Rank[(int)ICK_Num_Conversion_Kinds] = { 67 ICR_Exact_Match, 68 ICR_Exact_Match, 69 ICR_Exact_Match, 70 ICR_Exact_Match, 71 ICR_Exact_Match, 72 ICR_Exact_Match, 73 ICR_Promotion, 74 ICR_Promotion, 75 ICR_Promotion, 76 ICR_Conversion, 77 ICR_Conversion, 78 ICR_Conversion, 79 ICR_Conversion, 80 ICR_Conversion, 81 ICR_Conversion, 82 ICR_Conversion, 83 ICR_Conversion, 84 ICR_Conversion, 85 ICR_Conversion, 86 ICR_Conversion, 87 ICR_Complex_Real_Conversion 88 }; 89 return Rank[(int)Kind]; 90} 91 92/// GetImplicitConversionName - Return the name of this kind of 93/// implicit conversion. 94const char* GetImplicitConversionName(ImplicitConversionKind Kind) { 95 static const char* const Name[(int)ICK_Num_Conversion_Kinds] = { 96 "No conversion", 97 "Lvalue-to-rvalue", 98 "Array-to-pointer", 99 "Function-to-pointer", 100 "Noreturn adjustment", 101 "Qualification", 102 "Integral promotion", 103 "Floating point promotion", 104 "Complex promotion", 105 "Integral conversion", 106 "Floating conversion", 107 "Complex conversion", 108 "Floating-integral conversion", 109 "Pointer conversion", 110 "Pointer-to-member conversion", 111 "Boolean conversion", 112 "Compatible-types conversion", 113 "Derived-to-base conversion", 114 "Vector conversion", 115 "Vector splat", 116 "Complex-real conversion" 117 }; 118 return Name[Kind]; 119} 120 121/// StandardConversionSequence - Set the standard conversion 122/// sequence to the identity conversion. 123void StandardConversionSequence::setAsIdentityConversion() { 124 First = ICK_Identity; 125 Second = ICK_Identity; 126 Third = ICK_Identity; 127 DeprecatedStringLiteralToCharPtr = false; 128 ReferenceBinding = false; 129 DirectBinding = false; 130 RRefBinding = false; 131 CopyConstructor = 0; 132} 133 134/// getRank - Retrieve the rank of this standard conversion sequence 135/// (C++ 13.3.3.1.1p3). The rank is the largest rank of each of the 136/// implicit conversions. 137ImplicitConversionRank StandardConversionSequence::getRank() const { 138 ImplicitConversionRank Rank = ICR_Exact_Match; 139 if (GetConversionRank(First) > Rank) 140 Rank = GetConversionRank(First); 141 if (GetConversionRank(Second) > Rank) 142 Rank = GetConversionRank(Second); 143 if (GetConversionRank(Third) > Rank) 144 Rank = GetConversionRank(Third); 145 return Rank; 146} 147 148/// isPointerConversionToBool - Determines whether this conversion is 149/// a conversion of a pointer or pointer-to-member to bool. This is 150/// used as part of the ranking of standard conversion sequences 151/// (C++ 13.3.3.2p4). 152bool StandardConversionSequence::isPointerConversionToBool() const { 153 // Note that FromType has not necessarily been transformed by the 154 // array-to-pointer or function-to-pointer implicit conversions, so 155 // check for their presence as well as checking whether FromType is 156 // a pointer. 157 if (getToType(1)->isBooleanType() && 158 (getFromType()->isPointerType() || 159 getFromType()->isObjCObjectPointerType() || 160 getFromType()->isBlockPointerType() || 161 First == ICK_Array_To_Pointer || First == ICK_Function_To_Pointer)) 162 return true; 163 164 return false; 165} 166 167/// isPointerConversionToVoidPointer - Determines whether this 168/// conversion is a conversion of a pointer to a void pointer. This is 169/// used as part of the ranking of standard conversion sequences (C++ 170/// 13.3.3.2p4). 171bool 172StandardConversionSequence:: 173isPointerConversionToVoidPointer(ASTContext& Context) const { 174 QualType FromType = getFromType(); 175 QualType ToType = getToType(1); 176 177 // Note that FromType has not necessarily been transformed by the 178 // array-to-pointer implicit conversion, so check for its presence 179 // and redo the conversion to get a pointer. 180 if (First == ICK_Array_To_Pointer) 181 FromType = Context.getArrayDecayedType(FromType); 182 183 if (Second == ICK_Pointer_Conversion && FromType->isPointerType()) 184 if (const PointerType* ToPtrType = ToType->getAs<PointerType>()) 185 return ToPtrType->getPointeeType()->isVoidType(); 186 187 return false; 188} 189 190/// DebugPrint - Print this standard conversion sequence to standard 191/// error. Useful for debugging overloading issues. 192void StandardConversionSequence::DebugPrint() const { 193 llvm::raw_ostream &OS = llvm::errs(); 194 bool PrintedSomething = false; 195 if (First != ICK_Identity) { 196 OS << GetImplicitConversionName(First); 197 PrintedSomething = true; 198 } 199 200 if (Second != ICK_Identity) { 201 if (PrintedSomething) { 202 OS << " -> "; 203 } 204 OS << GetImplicitConversionName(Second); 205 206 if (CopyConstructor) { 207 OS << " (by copy constructor)"; 208 } else if (DirectBinding) { 209 OS << " (direct reference binding)"; 210 } else if (ReferenceBinding) { 211 OS << " (reference binding)"; 212 } 213 PrintedSomething = true; 214 } 215 216 if (Third != ICK_Identity) { 217 if (PrintedSomething) { 218 OS << " -> "; 219 } 220 OS << GetImplicitConversionName(Third); 221 PrintedSomething = true; 222 } 223 224 if (!PrintedSomething) { 225 OS << "No conversions required"; 226 } 227} 228 229/// DebugPrint - Print this user-defined conversion sequence to standard 230/// error. Useful for debugging overloading issues. 231void UserDefinedConversionSequence::DebugPrint() const { 232 llvm::raw_ostream &OS = llvm::errs(); 233 if (Before.First || Before.Second || Before.Third) { 234 Before.DebugPrint(); 235 OS << " -> "; 236 } 237 OS << '\'' << ConversionFunction << '\''; 238 if (After.First || After.Second || After.Third) { 239 OS << " -> "; 240 After.DebugPrint(); 241 } 242} 243 244/// DebugPrint - Print this implicit conversion sequence to standard 245/// error. Useful for debugging overloading issues. 246void ImplicitConversionSequence::DebugPrint() const { 247 llvm::raw_ostream &OS = llvm::errs(); 248 switch (ConversionKind) { 249 case StandardConversion: 250 OS << "Standard conversion: "; 251 Standard.DebugPrint(); 252 break; 253 case UserDefinedConversion: 254 OS << "User-defined conversion: "; 255 UserDefined.DebugPrint(); 256 break; 257 case EllipsisConversion: 258 OS << "Ellipsis conversion"; 259 break; 260 case AmbiguousConversion: 261 OS << "Ambiguous conversion"; 262 break; 263 case BadConversion: 264 OS << "Bad conversion"; 265 break; 266 } 267 268 OS << "\n"; 269} 270 271void AmbiguousConversionSequence::construct() { 272 new (&conversions()) ConversionSet(); 273} 274 275void AmbiguousConversionSequence::destruct() { 276 conversions().~ConversionSet(); 277} 278 279void 280AmbiguousConversionSequence::copyFrom(const AmbiguousConversionSequence &O) { 281 FromTypePtr = O.FromTypePtr; 282 ToTypePtr = O.ToTypePtr; 283 new (&conversions()) ConversionSet(O.conversions()); 284} 285 286namespace { 287 // Structure used by OverloadCandidate::DeductionFailureInfo to store 288 // template parameter and template argument information. 289 struct DFIParamWithArguments { 290 TemplateParameter Param; 291 TemplateArgument FirstArg; 292 TemplateArgument SecondArg; 293 }; 294} 295 296/// \brief Convert from Sema's representation of template deduction information 297/// to the form used in overload-candidate information. 298OverloadCandidate::DeductionFailureInfo 299static MakeDeductionFailureInfo(ASTContext &Context, 300 Sema::TemplateDeductionResult TDK, 301 Sema::TemplateDeductionInfo &Info) { 302 OverloadCandidate::DeductionFailureInfo Result; 303 Result.Result = static_cast<unsigned>(TDK); 304 Result.Data = 0; 305 switch (TDK) { 306 case Sema::TDK_Success: 307 case Sema::TDK_InstantiationDepth: 308 case Sema::TDK_TooManyArguments: 309 case Sema::TDK_TooFewArguments: 310 break; 311 312 case Sema::TDK_Incomplete: 313 case Sema::TDK_InvalidExplicitArguments: 314 Result.Data = Info.Param.getOpaqueValue(); 315 break; 316 317 case Sema::TDK_Inconsistent: 318 case Sema::TDK_Underqualified: { 319 // FIXME: Should allocate from normal heap so that we can free this later. 320 DFIParamWithArguments *Saved = new (Context) DFIParamWithArguments; 321 Saved->Param = Info.Param; 322 Saved->FirstArg = Info.FirstArg; 323 Saved->SecondArg = Info.SecondArg; 324 Result.Data = Saved; 325 break; 326 } 327 328 case Sema::TDK_SubstitutionFailure: 329 Result.Data = Info.take(); 330 break; 331 332 case Sema::TDK_NonDeducedMismatch: 333 case Sema::TDK_FailedOverloadResolution: 334 break; 335 } 336 337 return Result; 338} 339 340void OverloadCandidate::DeductionFailureInfo::Destroy() { 341 switch (static_cast<Sema::TemplateDeductionResult>(Result)) { 342 case Sema::TDK_Success: 343 case Sema::TDK_InstantiationDepth: 344 case Sema::TDK_Incomplete: 345 case Sema::TDK_TooManyArguments: 346 case Sema::TDK_TooFewArguments: 347 case Sema::TDK_InvalidExplicitArguments: 348 break; 349 350 case Sema::TDK_Inconsistent: 351 case Sema::TDK_Underqualified: 352 // FIXME: Destroy the data? 353 Data = 0; 354 break; 355 356 case Sema::TDK_SubstitutionFailure: 357 // FIXME: Destroy the template arugment list? 358 Data = 0; 359 break; 360 361 // Unhandled 362 case Sema::TDK_NonDeducedMismatch: 363 case Sema::TDK_FailedOverloadResolution: 364 break; 365 } 366} 367 368TemplateParameter 369OverloadCandidate::DeductionFailureInfo::getTemplateParameter() { 370 switch (static_cast<Sema::TemplateDeductionResult>(Result)) { 371 case Sema::TDK_Success: 372 case Sema::TDK_InstantiationDepth: 373 case Sema::TDK_TooManyArguments: 374 case Sema::TDK_TooFewArguments: 375 case Sema::TDK_SubstitutionFailure: 376 return TemplateParameter(); 377 378 case Sema::TDK_Incomplete: 379 case Sema::TDK_InvalidExplicitArguments: 380 return TemplateParameter::getFromOpaqueValue(Data); 381 382 case Sema::TDK_Inconsistent: 383 case Sema::TDK_Underqualified: 384 return static_cast<DFIParamWithArguments*>(Data)->Param; 385 386 // Unhandled 387 case Sema::TDK_NonDeducedMismatch: 388 case Sema::TDK_FailedOverloadResolution: 389 break; 390 } 391 392 return TemplateParameter(); 393} 394 395TemplateArgumentList * 396OverloadCandidate::DeductionFailureInfo::getTemplateArgumentList() { 397 switch (static_cast<Sema::TemplateDeductionResult>(Result)) { 398 case Sema::TDK_Success: 399 case Sema::TDK_InstantiationDepth: 400 case Sema::TDK_TooManyArguments: 401 case Sema::TDK_TooFewArguments: 402 case Sema::TDK_Incomplete: 403 case Sema::TDK_InvalidExplicitArguments: 404 case Sema::TDK_Inconsistent: 405 case Sema::TDK_Underqualified: 406 return 0; 407 408 case Sema::TDK_SubstitutionFailure: 409 return static_cast<TemplateArgumentList*>(Data); 410 411 // Unhandled 412 case Sema::TDK_NonDeducedMismatch: 413 case Sema::TDK_FailedOverloadResolution: 414 break; 415 } 416 417 return 0; 418} 419 420const TemplateArgument *OverloadCandidate::DeductionFailureInfo::getFirstArg() { 421 switch (static_cast<Sema::TemplateDeductionResult>(Result)) { 422 case Sema::TDK_Success: 423 case Sema::TDK_InstantiationDepth: 424 case Sema::TDK_Incomplete: 425 case Sema::TDK_TooManyArguments: 426 case Sema::TDK_TooFewArguments: 427 case Sema::TDK_InvalidExplicitArguments: 428 case Sema::TDK_SubstitutionFailure: 429 return 0; 430 431 case Sema::TDK_Inconsistent: 432 case Sema::TDK_Underqualified: 433 return &static_cast<DFIParamWithArguments*>(Data)->FirstArg; 434 435 // Unhandled 436 case Sema::TDK_NonDeducedMismatch: 437 case Sema::TDK_FailedOverloadResolution: 438 break; 439 } 440 441 return 0; 442} 443 444const TemplateArgument * 445OverloadCandidate::DeductionFailureInfo::getSecondArg() { 446 switch (static_cast<Sema::TemplateDeductionResult>(Result)) { 447 case Sema::TDK_Success: 448 case Sema::TDK_InstantiationDepth: 449 case Sema::TDK_Incomplete: 450 case Sema::TDK_TooManyArguments: 451 case Sema::TDK_TooFewArguments: 452 case Sema::TDK_InvalidExplicitArguments: 453 case Sema::TDK_SubstitutionFailure: 454 return 0; 455 456 case Sema::TDK_Inconsistent: 457 case Sema::TDK_Underqualified: 458 return &static_cast<DFIParamWithArguments*>(Data)->SecondArg; 459 460 // Unhandled 461 case Sema::TDK_NonDeducedMismatch: 462 case Sema::TDK_FailedOverloadResolution: 463 break; 464 } 465 466 return 0; 467} 468 469void OverloadCandidateSet::clear() { 470 inherited::clear(); 471 Functions.clear(); 472} 473 474// IsOverload - Determine whether the given New declaration is an 475// overload of the declarations in Old. This routine returns false if 476// New and Old cannot be overloaded, e.g., if New has the same 477// signature as some function in Old (C++ 1.3.10) or if the Old 478// declarations aren't functions (or function templates) at all. When 479// it does return false, MatchedDecl will point to the decl that New 480// cannot be overloaded with. This decl may be a UsingShadowDecl on 481// top of the underlying declaration. 482// 483// Example: Given the following input: 484// 485// void f(int, float); // #1 486// void f(int, int); // #2 487// int f(int, int); // #3 488// 489// When we process #1, there is no previous declaration of "f", 490// so IsOverload will not be used. 491// 492// When we process #2, Old contains only the FunctionDecl for #1. By 493// comparing the parameter types, we see that #1 and #2 are overloaded 494// (since they have different signatures), so this routine returns 495// false; MatchedDecl is unchanged. 496// 497// When we process #3, Old is an overload set containing #1 and #2. We 498// compare the signatures of #3 to #1 (they're overloaded, so we do 499// nothing) and then #3 to #2. Since the signatures of #3 and #2 are 500// identical (return types of functions are not part of the 501// signature), IsOverload returns false and MatchedDecl will be set to 502// point to the FunctionDecl for #2. 503// 504// 'NewIsUsingShadowDecl' indicates that 'New' is being introduced 505// into a class by a using declaration. The rules for whether to hide 506// shadow declarations ignore some properties which otherwise figure 507// into a function template's signature. 508Sema::OverloadKind 509Sema::CheckOverload(Scope *S, FunctionDecl *New, const LookupResult &Old, 510 NamedDecl *&Match, bool NewIsUsingDecl) { 511 for (LookupResult::iterator I = Old.begin(), E = Old.end(); 512 I != E; ++I) { 513 NamedDecl *OldD = *I; 514 515 bool OldIsUsingDecl = false; 516 if (isa<UsingShadowDecl>(OldD)) { 517 OldIsUsingDecl = true; 518 519 // We can always introduce two using declarations into the same 520 // context, even if they have identical signatures. 521 if (NewIsUsingDecl) continue; 522 523 OldD = cast<UsingShadowDecl>(OldD)->getTargetDecl(); 524 } 525 526 // If either declaration was introduced by a using declaration, 527 // we'll need to use slightly different rules for matching. 528 // Essentially, these rules are the normal rules, except that 529 // function templates hide function templates with different 530 // return types or template parameter lists. 531 bool UseMemberUsingDeclRules = 532 (OldIsUsingDecl || NewIsUsingDecl) && CurContext->isRecord(); 533 534 if (FunctionTemplateDecl *OldT = dyn_cast<FunctionTemplateDecl>(OldD)) { 535 if (!IsOverload(New, OldT->getTemplatedDecl(), UseMemberUsingDeclRules)) { 536 if (UseMemberUsingDeclRules && OldIsUsingDecl) { 537 HideUsingShadowDecl(S, cast<UsingShadowDecl>(*I)); 538 continue; 539 } 540 541 Match = *I; 542 return Ovl_Match; 543 } 544 } else if (FunctionDecl *OldF = dyn_cast<FunctionDecl>(OldD)) { 545 if (!IsOverload(New, OldF, UseMemberUsingDeclRules)) { 546 if (UseMemberUsingDeclRules && OldIsUsingDecl) { 547 HideUsingShadowDecl(S, cast<UsingShadowDecl>(*I)); 548 continue; 549 } 550 551 Match = *I; 552 return Ovl_Match; 553 } 554 } else if (isa<UsingDecl>(OldD) || isa<TagDecl>(OldD)) { 555 // We can overload with these, which can show up when doing 556 // redeclaration checks for UsingDecls. 557 assert(Old.getLookupKind() == LookupUsingDeclName); 558 } else if (isa<UnresolvedUsingValueDecl>(OldD)) { 559 // Optimistically assume that an unresolved using decl will 560 // overload; if it doesn't, we'll have to diagnose during 561 // template instantiation. 562 } else { 563 // (C++ 13p1): 564 // Only function declarations can be overloaded; object and type 565 // declarations cannot be overloaded. 566 Match = *I; 567 return Ovl_NonFunction; 568 } 569 } 570 571 return Ovl_Overload; 572} 573 574bool Sema::IsOverload(FunctionDecl *New, FunctionDecl *Old, 575 bool UseUsingDeclRules) { 576 FunctionTemplateDecl *OldTemplate = Old->getDescribedFunctionTemplate(); 577 FunctionTemplateDecl *NewTemplate = New->getDescribedFunctionTemplate(); 578 579 // C++ [temp.fct]p2: 580 // A function template can be overloaded with other function templates 581 // and with normal (non-template) functions. 582 if ((OldTemplate == 0) != (NewTemplate == 0)) 583 return true; 584 585 // Is the function New an overload of the function Old? 586 QualType OldQType = Context.getCanonicalType(Old->getType()); 587 QualType NewQType = Context.getCanonicalType(New->getType()); 588 589 // Compare the signatures (C++ 1.3.10) of the two functions to 590 // determine whether they are overloads. If we find any mismatch 591 // in the signature, they are overloads. 592 593 // If either of these functions is a K&R-style function (no 594 // prototype), then we consider them to have matching signatures. 595 if (isa<FunctionNoProtoType>(OldQType.getTypePtr()) || 596 isa<FunctionNoProtoType>(NewQType.getTypePtr())) 597 return false; 598 599 FunctionProtoType* OldType = cast<FunctionProtoType>(OldQType); 600 FunctionProtoType* NewType = cast<FunctionProtoType>(NewQType); 601 602 // The signature of a function includes the types of its 603 // parameters (C++ 1.3.10), which includes the presence or absence 604 // of the ellipsis; see C++ DR 357). 605 if (OldQType != NewQType && 606 (OldType->getNumArgs() != NewType->getNumArgs() || 607 OldType->isVariadic() != NewType->isVariadic() || 608 !FunctionArgTypesAreEqual(OldType, NewType))) 609 return true; 610 611 // C++ [temp.over.link]p4: 612 // The signature of a function template consists of its function 613 // signature, its return type and its template parameter list. The names 614 // of the template parameters are significant only for establishing the 615 // relationship between the template parameters and the rest of the 616 // signature. 617 // 618 // We check the return type and template parameter lists for function 619 // templates first; the remaining checks follow. 620 // 621 // However, we don't consider either of these when deciding whether 622 // a member introduced by a shadow declaration is hidden. 623 if (!UseUsingDeclRules && NewTemplate && 624 (!TemplateParameterListsAreEqual(NewTemplate->getTemplateParameters(), 625 OldTemplate->getTemplateParameters(), 626 false, TPL_TemplateMatch) || 627 OldType->getResultType() != NewType->getResultType())) 628 return true; 629 630 // If the function is a class member, its signature includes the 631 // cv-qualifiers (if any) on the function itself. 632 // 633 // As part of this, also check whether one of the member functions 634 // is static, in which case they are not overloads (C++ 635 // 13.1p2). While not part of the definition of the signature, 636 // this check is important to determine whether these functions 637 // can be overloaded. 638 CXXMethodDecl* OldMethod = dyn_cast<CXXMethodDecl>(Old); 639 CXXMethodDecl* NewMethod = dyn_cast<CXXMethodDecl>(New); 640 if (OldMethod && NewMethod && 641 !OldMethod->isStatic() && !NewMethod->isStatic() && 642 OldMethod->getTypeQualifiers() != NewMethod->getTypeQualifiers()) 643 return true; 644 645 // The signatures match; this is not an overload. 646 return false; 647} 648 649/// TryImplicitConversion - Attempt to perform an implicit conversion 650/// from the given expression (Expr) to the given type (ToType). This 651/// function returns an implicit conversion sequence that can be used 652/// to perform the initialization. Given 653/// 654/// void f(float f); 655/// void g(int i) { f(i); } 656/// 657/// this routine would produce an implicit conversion sequence to 658/// describe the initialization of f from i, which will be a standard 659/// conversion sequence containing an lvalue-to-rvalue conversion (C++ 660/// 4.1) followed by a floating-integral conversion (C++ 4.9). 661// 662/// Note that this routine only determines how the conversion can be 663/// performed; it does not actually perform the conversion. As such, 664/// it will not produce any diagnostics if no conversion is available, 665/// but will instead return an implicit conversion sequence of kind 666/// "BadConversion". 667/// 668/// If @p SuppressUserConversions, then user-defined conversions are 669/// not permitted. 670/// If @p AllowExplicit, then explicit user-defined conversions are 671/// permitted. 672ImplicitConversionSequence 673Sema::TryImplicitConversion(Expr* From, QualType ToType, 674 bool SuppressUserConversions, 675 bool AllowExplicit, 676 bool InOverloadResolution) { 677 ImplicitConversionSequence ICS; 678 if (IsStandardConversion(From, ToType, InOverloadResolution, ICS.Standard)) { 679 ICS.setStandard(); 680 return ICS; 681 } 682 683 if (!getLangOptions().CPlusPlus) { 684 ICS.setBad(BadConversionSequence::no_conversion, From, ToType); 685 return ICS; 686 } 687 688 if (SuppressUserConversions) { 689 // C++ [over.ics.user]p4: 690 // A conversion of an expression of class type to the same class 691 // type is given Exact Match rank, and a conversion of an 692 // expression of class type to a base class of that type is 693 // given Conversion rank, in spite of the fact that a copy/move 694 // constructor (i.e., a user-defined conversion function) is 695 // called for those cases. 696 QualType FromType = From->getType(); 697 if (!ToType->getAs<RecordType>() || !FromType->getAs<RecordType>() || 698 !(Context.hasSameUnqualifiedType(FromType, ToType) || 699 IsDerivedFrom(FromType, ToType))) { 700 // We're not in the case above, so there is no conversion that 701 // we can perform. 702 ICS.setBad(BadConversionSequence::no_conversion, From, ToType); 703 return ICS; 704 } 705 706 ICS.setStandard(); 707 ICS.Standard.setAsIdentityConversion(); 708 ICS.Standard.setFromType(FromType); 709 ICS.Standard.setAllToTypes(ToType); 710 711 // We don't actually check at this point whether there is a valid 712 // copy/move constructor, since overloading just assumes that it 713 // exists. When we actually perform initialization, we'll find the 714 // appropriate constructor to copy the returned object, if needed. 715 ICS.Standard.CopyConstructor = 0; 716 717 // Determine whether this is considered a derived-to-base conversion. 718 if (!Context.hasSameUnqualifiedType(FromType, ToType)) 719 ICS.Standard.Second = ICK_Derived_To_Base; 720 721 return ICS; 722 } 723 724 // Attempt user-defined conversion. 725 OverloadCandidateSet Conversions(From->getExprLoc()); 726 OverloadingResult UserDefResult 727 = IsUserDefinedConversion(From, ToType, ICS.UserDefined, Conversions, 728 AllowExplicit); 729 730 if (UserDefResult == OR_Success) { 731 ICS.setUserDefined(); 732 // C++ [over.ics.user]p4: 733 // A conversion of an expression of class type to the same class 734 // type is given Exact Match rank, and a conversion of an 735 // expression of class type to a base class of that type is 736 // given Conversion rank, in spite of the fact that a copy 737 // constructor (i.e., a user-defined conversion function) is 738 // called for those cases. 739 if (CXXConstructorDecl *Constructor 740 = dyn_cast<CXXConstructorDecl>(ICS.UserDefined.ConversionFunction)) { 741 QualType FromCanon 742 = Context.getCanonicalType(From->getType().getUnqualifiedType()); 743 QualType ToCanon = Context.getCanonicalType(ToType).getUnqualifiedType(); 744 if (Constructor->isCopyConstructor() && 745 (FromCanon == ToCanon || IsDerivedFrom(FromCanon, ToCanon))) { 746 // Turn this into a "standard" conversion sequence, so that it 747 // gets ranked with standard conversion sequences. 748 ICS.setStandard(); 749 ICS.Standard.setAsIdentityConversion(); 750 ICS.Standard.setFromType(From->getType()); 751 ICS.Standard.setAllToTypes(ToType); 752 ICS.Standard.CopyConstructor = Constructor; 753 if (ToCanon != FromCanon) 754 ICS.Standard.Second = ICK_Derived_To_Base; 755 } 756 } 757 758 // C++ [over.best.ics]p4: 759 // However, when considering the argument of a user-defined 760 // conversion function that is a candidate by 13.3.1.3 when 761 // invoked for the copying of the temporary in the second step 762 // of a class copy-initialization, or by 13.3.1.4, 13.3.1.5, or 763 // 13.3.1.6 in all cases, only standard conversion sequences and 764 // ellipsis conversion sequences are allowed. 765 if (SuppressUserConversions && ICS.isUserDefined()) { 766 ICS.setBad(BadConversionSequence::suppressed_user, From, ToType); 767 } 768 } else if (UserDefResult == OR_Ambiguous && !SuppressUserConversions) { 769 ICS.setAmbiguous(); 770 ICS.Ambiguous.setFromType(From->getType()); 771 ICS.Ambiguous.setToType(ToType); 772 for (OverloadCandidateSet::iterator Cand = Conversions.begin(); 773 Cand != Conversions.end(); ++Cand) 774 if (Cand->Viable) 775 ICS.Ambiguous.addConversion(Cand->Function); 776 } else { 777 ICS.setBad(BadConversionSequence::no_conversion, From, ToType); 778 } 779 780 return ICS; 781} 782 783/// PerformImplicitConversion - Perform an implicit conversion of the 784/// expression From to the type ToType. Returns true if there was an 785/// error, false otherwise. The expression From is replaced with the 786/// converted expression. Flavor is the kind of conversion we're 787/// performing, used in the error message. If @p AllowExplicit, 788/// explicit user-defined conversions are permitted. 789bool 790Sema::PerformImplicitConversion(Expr *&From, QualType ToType, 791 AssignmentAction Action, bool AllowExplicit) { 792 ImplicitConversionSequence ICS; 793 return PerformImplicitConversion(From, ToType, Action, AllowExplicit, ICS); 794} 795 796bool 797Sema::PerformImplicitConversion(Expr *&From, QualType ToType, 798 AssignmentAction Action, bool AllowExplicit, 799 ImplicitConversionSequence& ICS) { 800 ICS = TryImplicitConversion(From, ToType, 801 /*SuppressUserConversions=*/false, 802 AllowExplicit, 803 /*InOverloadResolution=*/false); 804 return PerformImplicitConversion(From, ToType, ICS, Action); 805} 806 807/// \brief Determine whether the conversion from FromType to ToType is a valid 808/// conversion that strips "noreturn" off the nested function type. 809static bool IsNoReturnConversion(ASTContext &Context, QualType FromType, 810 QualType ToType, QualType &ResultTy) { 811 if (Context.hasSameUnqualifiedType(FromType, ToType)) 812 return false; 813 814 // Strip the noreturn off the type we're converting from; noreturn can 815 // safely be removed. 816 FromType = Context.getNoReturnType(FromType, false); 817 if (!Context.hasSameUnqualifiedType(FromType, ToType)) 818 return false; 819 820 ResultTy = FromType; 821 return true; 822} 823 824/// \brief Determine whether the conversion from FromType to ToType is a valid 825/// vector conversion. 826/// 827/// \param ICK Will be set to the vector conversion kind, if this is a vector 828/// conversion. 829static bool IsVectorConversion(ASTContext &Context, QualType FromType, 830 QualType ToType, ImplicitConversionKind &ICK) { 831 // We need at least one of these types to be a vector type to have a vector 832 // conversion. 833 if (!ToType->isVectorType() && !FromType->isVectorType()) 834 return false; 835 836 // Identical types require no conversions. 837 if (Context.hasSameUnqualifiedType(FromType, ToType)) 838 return false; 839 840 // There are no conversions between extended vector types, only identity. 841 if (ToType->isExtVectorType()) { 842 // There are no conversions between extended vector types other than the 843 // identity conversion. 844 if (FromType->isExtVectorType()) 845 return false; 846 847 // Vector splat from any arithmetic type to a vector. 848 if (FromType->isArithmeticType()) { 849 ICK = ICK_Vector_Splat; 850 return true; 851 } 852 } 853 854 // If lax vector conversions are permitted and the vector types are of the 855 // same size, we can perform the conversion. 856 if (Context.getLangOptions().LaxVectorConversions && 857 FromType->isVectorType() && ToType->isVectorType() && 858 Context.getTypeSize(FromType) == Context.getTypeSize(ToType)) { 859 ICK = ICK_Vector_Conversion; 860 return true; 861 } 862 863 return false; 864} 865 866/// IsStandardConversion - Determines whether there is a standard 867/// conversion sequence (C++ [conv], C++ [over.ics.scs]) from the 868/// expression From to the type ToType. Standard conversion sequences 869/// only consider non-class types; for conversions that involve class 870/// types, use TryImplicitConversion. If a conversion exists, SCS will 871/// contain the standard conversion sequence required to perform this 872/// conversion and this routine will return true. Otherwise, this 873/// routine will return false and the value of SCS is unspecified. 874bool 875Sema::IsStandardConversion(Expr* From, QualType ToType, 876 bool InOverloadResolution, 877 StandardConversionSequence &SCS) { 878 QualType FromType = From->getType(); 879 880 // Standard conversions (C++ [conv]) 881 SCS.setAsIdentityConversion(); 882 SCS.DeprecatedStringLiteralToCharPtr = false; 883 SCS.IncompatibleObjC = false; 884 SCS.setFromType(FromType); 885 SCS.CopyConstructor = 0; 886 887 // There are no standard conversions for class types in C++, so 888 // abort early. When overloading in C, however, we do permit 889 if (FromType->isRecordType() || ToType->isRecordType()) { 890 if (getLangOptions().CPlusPlus) 891 return false; 892 893 // When we're overloading in C, we allow, as standard conversions, 894 } 895 896 // The first conversion can be an lvalue-to-rvalue conversion, 897 // array-to-pointer conversion, or function-to-pointer conversion 898 // (C++ 4p1). 899 900 if (FromType == Context.OverloadTy) { 901 DeclAccessPair AccessPair; 902 if (FunctionDecl *Fn 903 = ResolveAddressOfOverloadedFunction(From, ToType, false, 904 AccessPair)) { 905 // We were able to resolve the address of the overloaded function, 906 // so we can convert to the type of that function. 907 FromType = Fn->getType(); 908 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 909 if (!Method->isStatic()) { 910 Type *ClassType 911 = Context.getTypeDeclType(Method->getParent()).getTypePtr(); 912 FromType = Context.getMemberPointerType(FromType, ClassType); 913 } 914 } 915 916 // If the "from" expression takes the address of the overloaded 917 // function, update the type of the resulting expression accordingly. 918 if (FromType->getAs<FunctionType>()) 919 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(From->IgnoreParens())) 920 if (UnOp->getOpcode() == UnaryOperator::AddrOf) 921 FromType = Context.getPointerType(FromType); 922 923 // Check that we've computed the proper type after overload resolution. 924 assert(Context.hasSameType(FromType, 925 FixOverloadedFunctionReference(From, AccessPair, Fn)->getType())); 926 } else { 927 return false; 928 } 929 } 930 // Lvalue-to-rvalue conversion (C++ 4.1): 931 // An lvalue (3.10) of a non-function, non-array type T can be 932 // converted to an rvalue. 933 Expr::isLvalueResult argIsLvalue = From->isLvalue(Context); 934 if (argIsLvalue == Expr::LV_Valid && 935 !FromType->isFunctionType() && !FromType->isArrayType() && 936 Context.getCanonicalType(FromType) != Context.OverloadTy) { 937 SCS.First = ICK_Lvalue_To_Rvalue; 938 939 // If T is a non-class type, the type of the rvalue is the 940 // cv-unqualified version of T. Otherwise, the type of the rvalue 941 // is T (C++ 4.1p1). C++ can't get here with class types; in C, we 942 // just strip the qualifiers because they don't matter. 943 FromType = FromType.getUnqualifiedType(); 944 } else if (FromType->isArrayType()) { 945 // Array-to-pointer conversion (C++ 4.2) 946 SCS.First = ICK_Array_To_Pointer; 947 948 // An lvalue or rvalue of type "array of N T" or "array of unknown 949 // bound of T" can be converted to an rvalue of type "pointer to 950 // T" (C++ 4.2p1). 951 FromType = Context.getArrayDecayedType(FromType); 952 953 if (IsStringLiteralToNonConstPointerConversion(From, ToType)) { 954 // This conversion is deprecated. (C++ D.4). 955 SCS.DeprecatedStringLiteralToCharPtr = true; 956 957 // For the purpose of ranking in overload resolution 958 // (13.3.3.1.1), this conversion is considered an 959 // array-to-pointer conversion followed by a qualification 960 // conversion (4.4). (C++ 4.2p2) 961 SCS.Second = ICK_Identity; 962 SCS.Third = ICK_Qualification; 963 SCS.setAllToTypes(FromType); 964 return true; 965 } 966 } else if (FromType->isFunctionType() && argIsLvalue == Expr::LV_Valid) { 967 // Function-to-pointer conversion (C++ 4.3). 968 SCS.First = ICK_Function_To_Pointer; 969 970 // An lvalue of function type T can be converted to an rvalue of 971 // type "pointer to T." The result is a pointer to the 972 // function. (C++ 4.3p1). 973 FromType = Context.getPointerType(FromType); 974 } else { 975 // We don't require any conversions for the first step. 976 SCS.First = ICK_Identity; 977 } 978 SCS.setToType(0, FromType); 979 980 // The second conversion can be an integral promotion, floating 981 // point promotion, integral conversion, floating point conversion, 982 // floating-integral conversion, pointer conversion, 983 // pointer-to-member conversion, or boolean conversion (C++ 4p1). 984 // For overloading in C, this can also be a "compatible-type" 985 // conversion. 986 bool IncompatibleObjC = false; 987 ImplicitConversionKind SecondICK = ICK_Identity; 988 if (Context.hasSameUnqualifiedType(FromType, ToType)) { 989 // The unqualified versions of the types are the same: there's no 990 // conversion to do. 991 SCS.Second = ICK_Identity; 992 } else if (IsIntegralPromotion(From, FromType, ToType)) { 993 // Integral promotion (C++ 4.5). 994 SCS.Second = ICK_Integral_Promotion; 995 FromType = ToType.getUnqualifiedType(); 996 } else if (IsFloatingPointPromotion(FromType, ToType)) { 997 // Floating point promotion (C++ 4.6). 998 SCS.Second = ICK_Floating_Promotion; 999 FromType = ToType.getUnqualifiedType(); 1000 } else if (IsComplexPromotion(FromType, ToType)) { 1001 // Complex promotion (Clang extension) 1002 SCS.Second = ICK_Complex_Promotion; 1003 FromType = ToType.getUnqualifiedType(); 1004 } else if (FromType->isIntegralOrEnumerationType() && 1005 ToType->isIntegralType(Context)) { 1006 // Integral conversions (C++ 4.7). 1007 SCS.Second = ICK_Integral_Conversion; 1008 FromType = ToType.getUnqualifiedType(); 1009 } else if (FromType->isComplexType() && ToType->isComplexType()) { 1010 // Complex conversions (C99 6.3.1.6) 1011 SCS.Second = ICK_Complex_Conversion; 1012 FromType = ToType.getUnqualifiedType(); 1013 } else if ((FromType->isComplexType() && ToType->isArithmeticType()) || 1014 (ToType->isComplexType() && FromType->isArithmeticType())) { 1015 // Complex-real conversions (C99 6.3.1.7) 1016 SCS.Second = ICK_Complex_Real; 1017 FromType = ToType.getUnqualifiedType(); 1018 } else if (FromType->isRealFloatingType() && ToType->isRealFloatingType()) { 1019 // Floating point conversions (C++ 4.8). 1020 SCS.Second = ICK_Floating_Conversion; 1021 FromType = ToType.getUnqualifiedType(); 1022 } else if ((FromType->isRealFloatingType() && 1023 ToType->isIntegralType(Context) && !ToType->isBooleanType()) || 1024 (FromType->isIntegralOrEnumerationType() && 1025 ToType->isRealFloatingType())) { 1026 // Floating-integral conversions (C++ 4.9). 1027 SCS.Second = ICK_Floating_Integral; 1028 FromType = ToType.getUnqualifiedType(); 1029 } else if (IsPointerConversion(From, FromType, ToType, InOverloadResolution, 1030 FromType, IncompatibleObjC)) { 1031 // Pointer conversions (C++ 4.10). 1032 SCS.Second = ICK_Pointer_Conversion; 1033 SCS.IncompatibleObjC = IncompatibleObjC; 1034 } else if (IsMemberPointerConversion(From, FromType, ToType, 1035 InOverloadResolution, FromType)) { 1036 // Pointer to member conversions (4.11). 1037 SCS.Second = ICK_Pointer_Member; 1038 } else if (ToType->isBooleanType() && 1039 (FromType->isArithmeticType() || 1040 FromType->isEnumeralType() || 1041 FromType->isAnyPointerType() || 1042 FromType->isBlockPointerType() || 1043 FromType->isMemberPointerType() || 1044 FromType->isNullPtrType())) { 1045 // Boolean conversions (C++ 4.12). 1046 SCS.Second = ICK_Boolean_Conversion; 1047 FromType = Context.BoolTy; 1048 } else if (IsVectorConversion(Context, FromType, ToType, SecondICK)) { 1049 SCS.Second = SecondICK; 1050 FromType = ToType.getUnqualifiedType(); 1051 } else if (!getLangOptions().CPlusPlus && 1052 Context.typesAreCompatible(ToType, FromType)) { 1053 // Compatible conversions (Clang extension for C function overloading) 1054 SCS.Second = ICK_Compatible_Conversion; 1055 FromType = ToType.getUnqualifiedType(); 1056 } else if (IsNoReturnConversion(Context, FromType, ToType, FromType)) { 1057 // Treat a conversion that strips "noreturn" as an identity conversion. 1058 SCS.Second = ICK_NoReturn_Adjustment; 1059 } else { 1060 // No second conversion required. 1061 SCS.Second = ICK_Identity; 1062 } 1063 SCS.setToType(1, FromType); 1064 1065 QualType CanonFrom; 1066 QualType CanonTo; 1067 // The third conversion can be a qualification conversion (C++ 4p1). 1068 if (IsQualificationConversion(FromType, ToType)) { 1069 SCS.Third = ICK_Qualification; 1070 FromType = ToType; 1071 CanonFrom = Context.getCanonicalType(FromType); 1072 CanonTo = Context.getCanonicalType(ToType); 1073 } else { 1074 // No conversion required 1075 SCS.Third = ICK_Identity; 1076 1077 // C++ [over.best.ics]p6: 1078 // [...] Any difference in top-level cv-qualification is 1079 // subsumed by the initialization itself and does not constitute 1080 // a conversion. [...] 1081 CanonFrom = Context.getCanonicalType(FromType); 1082 CanonTo = Context.getCanonicalType(ToType); 1083 if (CanonFrom.getLocalUnqualifiedType() 1084 == CanonTo.getLocalUnqualifiedType() && 1085 (CanonFrom.getLocalCVRQualifiers() != CanonTo.getLocalCVRQualifiers() 1086 || CanonFrom.getObjCGCAttr() != CanonTo.getObjCGCAttr())) { 1087 FromType = ToType; 1088 CanonFrom = CanonTo; 1089 } 1090 } 1091 SCS.setToType(2, FromType); 1092 1093 // If we have not converted the argument type to the parameter type, 1094 // this is a bad conversion sequence. 1095 if (CanonFrom != CanonTo) 1096 return false; 1097 1098 return true; 1099} 1100 1101/// IsIntegralPromotion - Determines whether the conversion from the 1102/// expression From (whose potentially-adjusted type is FromType) to 1103/// ToType is an integral promotion (C++ 4.5). If so, returns true and 1104/// sets PromotedType to the promoted type. 1105bool Sema::IsIntegralPromotion(Expr *From, QualType FromType, QualType ToType) { 1106 const BuiltinType *To = ToType->getAs<BuiltinType>(); 1107 // All integers are built-in. 1108 if (!To) { 1109 return false; 1110 } 1111 1112 // An rvalue of type char, signed char, unsigned char, short int, or 1113 // unsigned short int can be converted to an rvalue of type int if 1114 // int can represent all the values of the source type; otherwise, 1115 // the source rvalue can be converted to an rvalue of type unsigned 1116 // int (C++ 4.5p1). 1117 if (FromType->isPromotableIntegerType() && !FromType->isBooleanType() && 1118 !FromType->isEnumeralType()) { 1119 if (// We can promote any signed, promotable integer type to an int 1120 (FromType->isSignedIntegerType() || 1121 // We can promote any unsigned integer type whose size is 1122 // less than int to an int. 1123 (!FromType->isSignedIntegerType() && 1124 Context.getTypeSize(FromType) < Context.getTypeSize(ToType)))) { 1125 return To->getKind() == BuiltinType::Int; 1126 } 1127 1128 return To->getKind() == BuiltinType::UInt; 1129 } 1130 1131 // An rvalue of type wchar_t (3.9.1) or an enumeration type (7.2) 1132 // can be converted to an rvalue of the first of the following types 1133 // that can represent all the values of its underlying type: int, 1134 // unsigned int, long, or unsigned long (C++ 4.5p2). 1135 1136 // We pre-calculate the promotion type for enum types. 1137 if (const EnumType *FromEnumType = FromType->getAs<EnumType>()) 1138 if (ToType->isIntegerType()) 1139 return Context.hasSameUnqualifiedType(ToType, 1140 FromEnumType->getDecl()->getPromotionType()); 1141 1142 if (FromType->isWideCharType() && ToType->isIntegerType()) { 1143 // Determine whether the type we're converting from is signed or 1144 // unsigned. 1145 bool FromIsSigned; 1146 uint64_t FromSize = Context.getTypeSize(FromType); 1147 1148 // FIXME: Is wchar_t signed or unsigned? We assume it's signed for now. 1149 FromIsSigned = true; 1150 1151 // The types we'll try to promote to, in the appropriate 1152 // order. Try each of these types. 1153 QualType PromoteTypes[6] = { 1154 Context.IntTy, Context.UnsignedIntTy, 1155 Context.LongTy, Context.UnsignedLongTy , 1156 Context.LongLongTy, Context.UnsignedLongLongTy 1157 }; 1158 for (int Idx = 0; Idx < 6; ++Idx) { 1159 uint64_t ToSize = Context.getTypeSize(PromoteTypes[Idx]); 1160 if (FromSize < ToSize || 1161 (FromSize == ToSize && 1162 FromIsSigned == PromoteTypes[Idx]->isSignedIntegerType())) { 1163 // We found the type that we can promote to. If this is the 1164 // type we wanted, we have a promotion. Otherwise, no 1165 // promotion. 1166 return Context.hasSameUnqualifiedType(ToType, PromoteTypes[Idx]); 1167 } 1168 } 1169 } 1170 1171 // An rvalue for an integral bit-field (9.6) can be converted to an 1172 // rvalue of type int if int can represent all the values of the 1173 // bit-field; otherwise, it can be converted to unsigned int if 1174 // unsigned int can represent all the values of the bit-field. If 1175 // the bit-field is larger yet, no integral promotion applies to 1176 // it. If the bit-field has an enumerated type, it is treated as any 1177 // other value of that type for promotion purposes (C++ 4.5p3). 1178 // FIXME: We should delay checking of bit-fields until we actually perform the 1179 // conversion. 1180 using llvm::APSInt; 1181 if (From) 1182 if (FieldDecl *MemberDecl = From->getBitField()) { 1183 APSInt BitWidth; 1184 if (FromType->isIntegralType(Context) && 1185 MemberDecl->getBitWidth()->isIntegerConstantExpr(BitWidth, Context)) { 1186 APSInt ToSize(BitWidth.getBitWidth(), BitWidth.isUnsigned()); 1187 ToSize = Context.getTypeSize(ToType); 1188 1189 // Are we promoting to an int from a bitfield that fits in an int? 1190 if (BitWidth < ToSize || 1191 (FromType->isSignedIntegerType() && BitWidth <= ToSize)) { 1192 return To->getKind() == BuiltinType::Int; 1193 } 1194 1195 // Are we promoting to an unsigned int from an unsigned bitfield 1196 // that fits into an unsigned int? 1197 if (FromType->isUnsignedIntegerType() && BitWidth <= ToSize) { 1198 return To->getKind() == BuiltinType::UInt; 1199 } 1200 1201 return false; 1202 } 1203 } 1204 1205 // An rvalue of type bool can be converted to an rvalue of type int, 1206 // with false becoming zero and true becoming one (C++ 4.5p4). 1207 if (FromType->isBooleanType() && To->getKind() == BuiltinType::Int) { 1208 return true; 1209 } 1210 1211 return false; 1212} 1213 1214/// IsFloatingPointPromotion - Determines whether the conversion from 1215/// FromType to ToType is a floating point promotion (C++ 4.6). If so, 1216/// returns true and sets PromotedType to the promoted type. 1217bool Sema::IsFloatingPointPromotion(QualType FromType, QualType ToType) { 1218 /// An rvalue of type float can be converted to an rvalue of type 1219 /// double. (C++ 4.6p1). 1220 if (const BuiltinType *FromBuiltin = FromType->getAs<BuiltinType>()) 1221 if (const BuiltinType *ToBuiltin = ToType->getAs<BuiltinType>()) { 1222 if (FromBuiltin->getKind() == BuiltinType::Float && 1223 ToBuiltin->getKind() == BuiltinType::Double) 1224 return true; 1225 1226 // C99 6.3.1.5p1: 1227 // When a float is promoted to double or long double, or a 1228 // double is promoted to long double [...]. 1229 if (!getLangOptions().CPlusPlus && 1230 (FromBuiltin->getKind() == BuiltinType::Float || 1231 FromBuiltin->getKind() == BuiltinType::Double) && 1232 (ToBuiltin->getKind() == BuiltinType::LongDouble)) 1233 return true; 1234 } 1235 1236 return false; 1237} 1238 1239/// \brief Determine if a conversion is a complex promotion. 1240/// 1241/// A complex promotion is defined as a complex -> complex conversion 1242/// where the conversion between the underlying real types is a 1243/// floating-point or integral promotion. 1244bool Sema::IsComplexPromotion(QualType FromType, QualType ToType) { 1245 const ComplexType *FromComplex = FromType->getAs<ComplexType>(); 1246 if (!FromComplex) 1247 return false; 1248 1249 const ComplexType *ToComplex = ToType->getAs<ComplexType>(); 1250 if (!ToComplex) 1251 return false; 1252 1253 return IsFloatingPointPromotion(FromComplex->getElementType(), 1254 ToComplex->getElementType()) || 1255 IsIntegralPromotion(0, FromComplex->getElementType(), 1256 ToComplex->getElementType()); 1257} 1258 1259/// BuildSimilarlyQualifiedPointerType - In a pointer conversion from 1260/// the pointer type FromPtr to a pointer to type ToPointee, with the 1261/// same type qualifiers as FromPtr has on its pointee type. ToType, 1262/// if non-empty, will be a pointer to ToType that may or may not have 1263/// the right set of qualifiers on its pointee. 1264static QualType 1265BuildSimilarlyQualifiedPointerType(const PointerType *FromPtr, 1266 QualType ToPointee, QualType ToType, 1267 ASTContext &Context) { 1268 QualType CanonFromPointee = Context.getCanonicalType(FromPtr->getPointeeType()); 1269 QualType CanonToPointee = Context.getCanonicalType(ToPointee); 1270 Qualifiers Quals = CanonFromPointee.getQualifiers(); 1271 1272 // Exact qualifier match -> return the pointer type we're converting to. 1273 if (CanonToPointee.getLocalQualifiers() == Quals) { 1274 // ToType is exactly what we need. Return it. 1275 if (!ToType.isNull()) 1276 return ToType.getUnqualifiedType(); 1277 1278 // Build a pointer to ToPointee. It has the right qualifiers 1279 // already. 1280 return Context.getPointerType(ToPointee); 1281 } 1282 1283 // Just build a canonical type that has the right qualifiers. 1284 return Context.getPointerType( 1285 Context.getQualifiedType(CanonToPointee.getLocalUnqualifiedType(), 1286 Quals)); 1287} 1288 1289/// BuildSimilarlyQualifiedObjCObjectPointerType - In a pointer conversion from 1290/// the FromType, which is an objective-c pointer, to ToType, which may or may 1291/// not have the right set of qualifiers. 1292static QualType 1293BuildSimilarlyQualifiedObjCObjectPointerType(QualType FromType, 1294 QualType ToType, 1295 ASTContext &Context) { 1296 QualType CanonFromType = Context.getCanonicalType(FromType); 1297 QualType CanonToType = Context.getCanonicalType(ToType); 1298 Qualifiers Quals = CanonFromType.getQualifiers(); 1299 1300 // Exact qualifier match -> return the pointer type we're converting to. 1301 if (CanonToType.getLocalQualifiers() == Quals) 1302 return ToType; 1303 1304 // Just build a canonical type that has the right qualifiers. 1305 return Context.getQualifiedType(CanonToType.getLocalUnqualifiedType(), Quals); 1306} 1307 1308static bool isNullPointerConstantForConversion(Expr *Expr, 1309 bool InOverloadResolution, 1310 ASTContext &Context) { 1311 // Handle value-dependent integral null pointer constants correctly. 1312 // http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#903 1313 if (Expr->isValueDependent() && !Expr->isTypeDependent() && 1314 Expr->getType()->isIntegerType() && !Expr->getType()->isEnumeralType()) 1315 return !InOverloadResolution; 1316 1317 return Expr->isNullPointerConstant(Context, 1318 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull 1319 : Expr::NPC_ValueDependentIsNull); 1320} 1321 1322/// IsPointerConversion - Determines whether the conversion of the 1323/// expression From, which has the (possibly adjusted) type FromType, 1324/// can be converted to the type ToType via a pointer conversion (C++ 1325/// 4.10). If so, returns true and places the converted type (that 1326/// might differ from ToType in its cv-qualifiers at some level) into 1327/// ConvertedType. 1328/// 1329/// This routine also supports conversions to and from block pointers 1330/// and conversions with Objective-C's 'id', 'id<protocols...>', and 1331/// pointers to interfaces. FIXME: Once we've determined the 1332/// appropriate overloading rules for Objective-C, we may want to 1333/// split the Objective-C checks into a different routine; however, 1334/// GCC seems to consider all of these conversions to be pointer 1335/// conversions, so for now they live here. IncompatibleObjC will be 1336/// set if the conversion is an allowed Objective-C conversion that 1337/// should result in a warning. 1338bool Sema::IsPointerConversion(Expr *From, QualType FromType, QualType ToType, 1339 bool InOverloadResolution, 1340 QualType& ConvertedType, 1341 bool &IncompatibleObjC) { 1342 IncompatibleObjC = false; 1343 if (isObjCPointerConversion(FromType, ToType, ConvertedType, IncompatibleObjC)) 1344 return true; 1345 1346 // Conversion from a null pointer constant to any Objective-C pointer type. 1347 if (ToType->isObjCObjectPointerType() && 1348 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1349 ConvertedType = ToType; 1350 return true; 1351 } 1352 1353 // Blocks: Block pointers can be converted to void*. 1354 if (FromType->isBlockPointerType() && ToType->isPointerType() && 1355 ToType->getAs<PointerType>()->getPointeeType()->isVoidType()) { 1356 ConvertedType = ToType; 1357 return true; 1358 } 1359 // Blocks: A null pointer constant can be converted to a block 1360 // pointer type. 1361 if (ToType->isBlockPointerType() && 1362 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1363 ConvertedType = ToType; 1364 return true; 1365 } 1366 1367 // If the left-hand-side is nullptr_t, the right side can be a null 1368 // pointer constant. 1369 if (ToType->isNullPtrType() && 1370 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1371 ConvertedType = ToType; 1372 return true; 1373 } 1374 1375 const PointerType* ToTypePtr = ToType->getAs<PointerType>(); 1376 if (!ToTypePtr) 1377 return false; 1378 1379 // A null pointer constant can be converted to a pointer type (C++ 4.10p1). 1380 if (isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1381 ConvertedType = ToType; 1382 return true; 1383 } 1384 1385 // Beyond this point, both types need to be pointers 1386 // , including objective-c pointers. 1387 QualType ToPointeeType = ToTypePtr->getPointeeType(); 1388 if (FromType->isObjCObjectPointerType() && ToPointeeType->isVoidType()) { 1389 ConvertedType = BuildSimilarlyQualifiedObjCObjectPointerType(FromType, 1390 ToType, Context); 1391 return true; 1392 1393 } 1394 const PointerType *FromTypePtr = FromType->getAs<PointerType>(); 1395 if (!FromTypePtr) 1396 return false; 1397 1398 QualType FromPointeeType = FromTypePtr->getPointeeType(); 1399 1400 // An rvalue of type "pointer to cv T," where T is an object type, 1401 // can be converted to an rvalue of type "pointer to cv void" (C++ 1402 // 4.10p2). 1403 if (FromPointeeType->isIncompleteOrObjectType() && 1404 ToPointeeType->isVoidType()) { 1405 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1406 ToPointeeType, 1407 ToType, Context); 1408 return true; 1409 } 1410 1411 // When we're overloading in C, we allow a special kind of pointer 1412 // conversion for compatible-but-not-identical pointee types. 1413 if (!getLangOptions().CPlusPlus && 1414 Context.typesAreCompatible(FromPointeeType, ToPointeeType)) { 1415 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1416 ToPointeeType, 1417 ToType, Context); 1418 return true; 1419 } 1420 1421 // C++ [conv.ptr]p3: 1422 // 1423 // An rvalue of type "pointer to cv D," where D is a class type, 1424 // can be converted to an rvalue of type "pointer to cv B," where 1425 // B is a base class (clause 10) of D. If B is an inaccessible 1426 // (clause 11) or ambiguous (10.2) base class of D, a program that 1427 // necessitates this conversion is ill-formed. The result of the 1428 // conversion is a pointer to the base class sub-object of the 1429 // derived class object. The null pointer value is converted to 1430 // the null pointer value of the destination type. 1431 // 1432 // Note that we do not check for ambiguity or inaccessibility 1433 // here. That is handled by CheckPointerConversion. 1434 if (getLangOptions().CPlusPlus && 1435 FromPointeeType->isRecordType() && ToPointeeType->isRecordType() && 1436 !Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType) && 1437 !RequireCompleteType(From->getLocStart(), FromPointeeType, PDiag()) && 1438 IsDerivedFrom(FromPointeeType, ToPointeeType)) { 1439 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1440 ToPointeeType, 1441 ToType, Context); 1442 return true; 1443 } 1444 1445 return false; 1446} 1447 1448/// isObjCPointerConversion - Determines whether this is an 1449/// Objective-C pointer conversion. Subroutine of IsPointerConversion, 1450/// with the same arguments and return values. 1451bool Sema::isObjCPointerConversion(QualType FromType, QualType ToType, 1452 QualType& ConvertedType, 1453 bool &IncompatibleObjC) { 1454 if (!getLangOptions().ObjC1) 1455 return false; 1456 1457 // First, we handle all conversions on ObjC object pointer types. 1458 const ObjCObjectPointerType* ToObjCPtr = ToType->getAs<ObjCObjectPointerType>(); 1459 const ObjCObjectPointerType *FromObjCPtr = 1460 FromType->getAs<ObjCObjectPointerType>(); 1461 1462 if (ToObjCPtr && FromObjCPtr) { 1463 // Objective C++: We're able to convert between "id" or "Class" and a 1464 // pointer to any interface (in both directions). 1465 if (ToObjCPtr->isObjCBuiltinType() && FromObjCPtr->isObjCBuiltinType()) { 1466 ConvertedType = ToType; 1467 return true; 1468 } 1469 // Conversions with Objective-C's id<...>. 1470 if ((FromObjCPtr->isObjCQualifiedIdType() || 1471 ToObjCPtr->isObjCQualifiedIdType()) && 1472 Context.ObjCQualifiedIdTypesAreCompatible(ToType, FromType, 1473 /*compare=*/false)) { 1474 ConvertedType = ToType; 1475 return true; 1476 } 1477 // Objective C++: We're able to convert from a pointer to an 1478 // interface to a pointer to a different interface. 1479 if (Context.canAssignObjCInterfaces(ToObjCPtr, FromObjCPtr)) { 1480 const ObjCInterfaceType* LHS = ToObjCPtr->getInterfaceType(); 1481 const ObjCInterfaceType* RHS = FromObjCPtr->getInterfaceType(); 1482 if (getLangOptions().CPlusPlus && LHS && RHS && 1483 !ToObjCPtr->getPointeeType().isAtLeastAsQualifiedAs( 1484 FromObjCPtr->getPointeeType())) 1485 return false; 1486 ConvertedType = ToType; 1487 return true; 1488 } 1489 1490 if (Context.canAssignObjCInterfaces(FromObjCPtr, ToObjCPtr)) { 1491 // Okay: this is some kind of implicit downcast of Objective-C 1492 // interfaces, which is permitted. However, we're going to 1493 // complain about it. 1494 IncompatibleObjC = true; 1495 ConvertedType = FromType; 1496 return true; 1497 } 1498 } 1499 // Beyond this point, both types need to be C pointers or block pointers. 1500 QualType ToPointeeType; 1501 if (const PointerType *ToCPtr = ToType->getAs<PointerType>()) 1502 ToPointeeType = ToCPtr->getPointeeType(); 1503 else if (const BlockPointerType *ToBlockPtr = 1504 ToType->getAs<BlockPointerType>()) { 1505 // Objective C++: We're able to convert from a pointer to any object 1506 // to a block pointer type. 1507 if (FromObjCPtr && FromObjCPtr->isObjCBuiltinType()) { 1508 ConvertedType = ToType; 1509 return true; 1510 } 1511 ToPointeeType = ToBlockPtr->getPointeeType(); 1512 } 1513 else if (FromType->getAs<BlockPointerType>() && 1514 ToObjCPtr && ToObjCPtr->isObjCBuiltinType()) { 1515 // Objective C++: We're able to convert from a block pointer type to a 1516 // pointer to any object. 1517 ConvertedType = ToType; 1518 return true; 1519 } 1520 else 1521 return false; 1522 1523 QualType FromPointeeType; 1524 if (const PointerType *FromCPtr = FromType->getAs<PointerType>()) 1525 FromPointeeType = FromCPtr->getPointeeType(); 1526 else if (const BlockPointerType *FromBlockPtr = FromType->getAs<BlockPointerType>()) 1527 FromPointeeType = FromBlockPtr->getPointeeType(); 1528 else 1529 return false; 1530 1531 // If we have pointers to pointers, recursively check whether this 1532 // is an Objective-C conversion. 1533 if (FromPointeeType->isPointerType() && ToPointeeType->isPointerType() && 1534 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, 1535 IncompatibleObjC)) { 1536 // We always complain about this conversion. 1537 IncompatibleObjC = true; 1538 ConvertedType = ToType; 1539 return true; 1540 } 1541 // Allow conversion of pointee being objective-c pointer to another one; 1542 // as in I* to id. 1543 if (FromPointeeType->getAs<ObjCObjectPointerType>() && 1544 ToPointeeType->getAs<ObjCObjectPointerType>() && 1545 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, 1546 IncompatibleObjC)) { 1547 ConvertedType = ToType; 1548 return true; 1549 } 1550 1551 // If we have pointers to functions or blocks, check whether the only 1552 // differences in the argument and result types are in Objective-C 1553 // pointer conversions. If so, we permit the conversion (but 1554 // complain about it). 1555 const FunctionProtoType *FromFunctionType 1556 = FromPointeeType->getAs<FunctionProtoType>(); 1557 const FunctionProtoType *ToFunctionType 1558 = ToPointeeType->getAs<FunctionProtoType>(); 1559 if (FromFunctionType && ToFunctionType) { 1560 // If the function types are exactly the same, this isn't an 1561 // Objective-C pointer conversion. 1562 if (Context.getCanonicalType(FromPointeeType) 1563 == Context.getCanonicalType(ToPointeeType)) 1564 return false; 1565 1566 // Perform the quick checks that will tell us whether these 1567 // function types are obviously different. 1568 if (FromFunctionType->getNumArgs() != ToFunctionType->getNumArgs() || 1569 FromFunctionType->isVariadic() != ToFunctionType->isVariadic() || 1570 FromFunctionType->getTypeQuals() != ToFunctionType->getTypeQuals()) 1571 return false; 1572 1573 bool HasObjCConversion = false; 1574 if (Context.getCanonicalType(FromFunctionType->getResultType()) 1575 == Context.getCanonicalType(ToFunctionType->getResultType())) { 1576 // Okay, the types match exactly. Nothing to do. 1577 } else if (isObjCPointerConversion(FromFunctionType->getResultType(), 1578 ToFunctionType->getResultType(), 1579 ConvertedType, IncompatibleObjC)) { 1580 // Okay, we have an Objective-C pointer conversion. 1581 HasObjCConversion = true; 1582 } else { 1583 // Function types are too different. Abort. 1584 return false; 1585 } 1586 1587 // Check argument types. 1588 for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumArgs(); 1589 ArgIdx != NumArgs; ++ArgIdx) { 1590 QualType FromArgType = FromFunctionType->getArgType(ArgIdx); 1591 QualType ToArgType = ToFunctionType->getArgType(ArgIdx); 1592 if (Context.getCanonicalType(FromArgType) 1593 == Context.getCanonicalType(ToArgType)) { 1594 // Okay, the types match exactly. Nothing to do. 1595 } else if (isObjCPointerConversion(FromArgType, ToArgType, 1596 ConvertedType, IncompatibleObjC)) { 1597 // Okay, we have an Objective-C pointer conversion. 1598 HasObjCConversion = true; 1599 } else { 1600 // Argument types are too different. Abort. 1601 return false; 1602 } 1603 } 1604 1605 if (HasObjCConversion) { 1606 // We had an Objective-C conversion. Allow this pointer 1607 // conversion, but complain about it. 1608 ConvertedType = ToType; 1609 IncompatibleObjC = true; 1610 return true; 1611 } 1612 } 1613 1614 return false; 1615} 1616 1617/// FunctionArgTypesAreEqual - This routine checks two function proto types 1618/// for equlity of their argument types. Caller has already checked that 1619/// they have same number of arguments. This routine assumes that Objective-C 1620/// pointer types which only differ in their protocol qualifiers are equal. 1621bool Sema::FunctionArgTypesAreEqual(FunctionProtoType* OldType, 1622 FunctionProtoType* NewType){ 1623 if (!getLangOptions().ObjC1) 1624 return std::equal(OldType->arg_type_begin(), OldType->arg_type_end(), 1625 NewType->arg_type_begin()); 1626 1627 for (FunctionProtoType::arg_type_iterator O = OldType->arg_type_begin(), 1628 N = NewType->arg_type_begin(), 1629 E = OldType->arg_type_end(); O && (O != E); ++O, ++N) { 1630 QualType ToType = (*O); 1631 QualType FromType = (*N); 1632 if (ToType != FromType) { 1633 if (const PointerType *PTTo = ToType->getAs<PointerType>()) { 1634 if (const PointerType *PTFr = FromType->getAs<PointerType>()) 1635 if ((PTTo->getPointeeType()->isObjCQualifiedIdType() && 1636 PTFr->getPointeeType()->isObjCQualifiedIdType()) || 1637 (PTTo->getPointeeType()->isObjCQualifiedClassType() && 1638 PTFr->getPointeeType()->isObjCQualifiedClassType())) 1639 continue; 1640 } 1641 else if (const ObjCObjectPointerType *PTTo = 1642 ToType->getAs<ObjCObjectPointerType>()) { 1643 if (const ObjCObjectPointerType *PTFr = 1644 FromType->getAs<ObjCObjectPointerType>()) 1645 if (PTTo->getInterfaceDecl() == PTFr->getInterfaceDecl()) 1646 continue; 1647 } 1648 return false; 1649 } 1650 } 1651 return true; 1652} 1653 1654/// CheckPointerConversion - Check the pointer conversion from the 1655/// expression From to the type ToType. This routine checks for 1656/// ambiguous or inaccessible derived-to-base pointer 1657/// conversions for which IsPointerConversion has already returned 1658/// true. It returns true and produces a diagnostic if there was an 1659/// error, or returns false otherwise. 1660bool Sema::CheckPointerConversion(Expr *From, QualType ToType, 1661 CastExpr::CastKind &Kind, 1662 CXXBaseSpecifierArray& BasePath, 1663 bool IgnoreBaseAccess) { 1664 QualType FromType = From->getType(); 1665 1666 if (CXXBoolLiteralExpr* LitBool 1667 = dyn_cast<CXXBoolLiteralExpr>(From->IgnoreParens())) 1668 if (LitBool->getValue() == false) 1669 Diag(LitBool->getExprLoc(), diag::warn_init_pointer_from_false) 1670 << ToType; 1671 1672 if (const PointerType *FromPtrType = FromType->getAs<PointerType>()) 1673 if (const PointerType *ToPtrType = ToType->getAs<PointerType>()) { 1674 QualType FromPointeeType = FromPtrType->getPointeeType(), 1675 ToPointeeType = ToPtrType->getPointeeType(); 1676 1677 if (FromPointeeType->isRecordType() && ToPointeeType->isRecordType() && 1678 !Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType)) { 1679 // We must have a derived-to-base conversion. Check an 1680 // ambiguous or inaccessible conversion. 1681 if (CheckDerivedToBaseConversion(FromPointeeType, ToPointeeType, 1682 From->getExprLoc(), 1683 From->getSourceRange(), &BasePath, 1684 IgnoreBaseAccess)) 1685 return true; 1686 1687 // The conversion was successful. 1688 Kind = CastExpr::CK_DerivedToBase; 1689 } 1690 } 1691 if (const ObjCObjectPointerType *FromPtrType = 1692 FromType->getAs<ObjCObjectPointerType>()) 1693 if (const ObjCObjectPointerType *ToPtrType = 1694 ToType->getAs<ObjCObjectPointerType>()) { 1695 // Objective-C++ conversions are always okay. 1696 // FIXME: We should have a different class of conversions for the 1697 // Objective-C++ implicit conversions. 1698 if (FromPtrType->isObjCBuiltinType() || ToPtrType->isObjCBuiltinType()) 1699 return false; 1700 1701 } 1702 return false; 1703} 1704 1705/// IsMemberPointerConversion - Determines whether the conversion of the 1706/// expression From, which has the (possibly adjusted) type FromType, can be 1707/// converted to the type ToType via a member pointer conversion (C++ 4.11). 1708/// If so, returns true and places the converted type (that might differ from 1709/// ToType in its cv-qualifiers at some level) into ConvertedType. 1710bool Sema::IsMemberPointerConversion(Expr *From, QualType FromType, 1711 QualType ToType, 1712 bool InOverloadResolution, 1713 QualType &ConvertedType) { 1714 const MemberPointerType *ToTypePtr = ToType->getAs<MemberPointerType>(); 1715 if (!ToTypePtr) 1716 return false; 1717 1718 // A null pointer constant can be converted to a member pointer (C++ 4.11p1) 1719 if (From->isNullPointerConstant(Context, 1720 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull 1721 : Expr::NPC_ValueDependentIsNull)) { 1722 ConvertedType = ToType; 1723 return true; 1724 } 1725 1726 // Otherwise, both types have to be member pointers. 1727 const MemberPointerType *FromTypePtr = FromType->getAs<MemberPointerType>(); 1728 if (!FromTypePtr) 1729 return false; 1730 1731 // A pointer to member of B can be converted to a pointer to member of D, 1732 // where D is derived from B (C++ 4.11p2). 1733 QualType FromClass(FromTypePtr->getClass(), 0); 1734 QualType ToClass(ToTypePtr->getClass(), 0); 1735 // FIXME: What happens when these are dependent? Is this function even called? 1736 1737 if (IsDerivedFrom(ToClass, FromClass)) { 1738 ConvertedType = Context.getMemberPointerType(FromTypePtr->getPointeeType(), 1739 ToClass.getTypePtr()); 1740 return true; 1741 } 1742 1743 return false; 1744} 1745 1746/// CheckMemberPointerConversion - Check the member pointer conversion from the 1747/// expression From to the type ToType. This routine checks for ambiguous or 1748/// virtual or inaccessible base-to-derived member pointer conversions 1749/// for which IsMemberPointerConversion has already returned true. It returns 1750/// true and produces a diagnostic if there was an error, or returns false 1751/// otherwise. 1752bool Sema::CheckMemberPointerConversion(Expr *From, QualType ToType, 1753 CastExpr::CastKind &Kind, 1754 CXXBaseSpecifierArray &BasePath, 1755 bool IgnoreBaseAccess) { 1756 QualType FromType = From->getType(); 1757 const MemberPointerType *FromPtrType = FromType->getAs<MemberPointerType>(); 1758 if (!FromPtrType) { 1759 // This must be a null pointer to member pointer conversion 1760 assert(From->isNullPointerConstant(Context, 1761 Expr::NPC_ValueDependentIsNull) && 1762 "Expr must be null pointer constant!"); 1763 Kind = CastExpr::CK_NullToMemberPointer; 1764 return false; 1765 } 1766 1767 const MemberPointerType *ToPtrType = ToType->getAs<MemberPointerType>(); 1768 assert(ToPtrType && "No member pointer cast has a target type " 1769 "that is not a member pointer."); 1770 1771 QualType FromClass = QualType(FromPtrType->getClass(), 0); 1772 QualType ToClass = QualType(ToPtrType->getClass(), 0); 1773 1774 // FIXME: What about dependent types? 1775 assert(FromClass->isRecordType() && "Pointer into non-class."); 1776 assert(ToClass->isRecordType() && "Pointer into non-class."); 1777 1778 CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true, 1779 /*DetectVirtual=*/true); 1780 bool DerivationOkay = IsDerivedFrom(ToClass, FromClass, Paths); 1781 assert(DerivationOkay && 1782 "Should not have been called if derivation isn't OK."); 1783 (void)DerivationOkay; 1784 1785 if (Paths.isAmbiguous(Context.getCanonicalType(FromClass). 1786 getUnqualifiedType())) { 1787 std::string PathDisplayStr = getAmbiguousPathsDisplayString(Paths); 1788 Diag(From->getExprLoc(), diag::err_ambiguous_memptr_conv) 1789 << 0 << FromClass << ToClass << PathDisplayStr << From->getSourceRange(); 1790 return true; 1791 } 1792 1793 if (const RecordType *VBase = Paths.getDetectedVirtual()) { 1794 Diag(From->getExprLoc(), diag::err_memptr_conv_via_virtual) 1795 << FromClass << ToClass << QualType(VBase, 0) 1796 << From->getSourceRange(); 1797 return true; 1798 } 1799 1800 if (!IgnoreBaseAccess) 1801 CheckBaseClassAccess(From->getExprLoc(), FromClass, ToClass, 1802 Paths.front(), 1803 diag::err_downcast_from_inaccessible_base); 1804 1805 // Must be a base to derived member conversion. 1806 BuildBasePathArray(Paths, BasePath); 1807 Kind = CastExpr::CK_BaseToDerivedMemberPointer; 1808 return false; 1809} 1810 1811/// IsQualificationConversion - Determines whether the conversion from 1812/// an rvalue of type FromType to ToType is a qualification conversion 1813/// (C++ 4.4). 1814bool 1815Sema::IsQualificationConversion(QualType FromType, QualType ToType) { 1816 FromType = Context.getCanonicalType(FromType); 1817 ToType = Context.getCanonicalType(ToType); 1818 1819 // If FromType and ToType are the same type, this is not a 1820 // qualification conversion. 1821 if (FromType.getUnqualifiedType() == ToType.getUnqualifiedType()) 1822 return false; 1823 1824 // (C++ 4.4p4): 1825 // A conversion can add cv-qualifiers at levels other than the first 1826 // in multi-level pointers, subject to the following rules: [...] 1827 bool PreviousToQualsIncludeConst = true; 1828 bool UnwrappedAnyPointer = false; 1829 while (Context.UnwrapSimilarPointerTypes(FromType, ToType)) { 1830 // Within each iteration of the loop, we check the qualifiers to 1831 // determine if this still looks like a qualification 1832 // conversion. Then, if all is well, we unwrap one more level of 1833 // pointers or pointers-to-members and do it all again 1834 // until there are no more pointers or pointers-to-members left to 1835 // unwrap. 1836 UnwrappedAnyPointer = true; 1837 1838 // -- for every j > 0, if const is in cv 1,j then const is in cv 1839 // 2,j, and similarly for volatile. 1840 if (!ToType.isAtLeastAsQualifiedAs(FromType)) 1841 return false; 1842 1843 // -- if the cv 1,j and cv 2,j are different, then const is in 1844 // every cv for 0 < k < j. 1845 if (FromType.getCVRQualifiers() != ToType.getCVRQualifiers() 1846 && !PreviousToQualsIncludeConst) 1847 return false; 1848 1849 // Keep track of whether all prior cv-qualifiers in the "to" type 1850 // include const. 1851 PreviousToQualsIncludeConst 1852 = PreviousToQualsIncludeConst && ToType.isConstQualified(); 1853 } 1854 1855 // We are left with FromType and ToType being the pointee types 1856 // after unwrapping the original FromType and ToType the same number 1857 // of types. If we unwrapped any pointers, and if FromType and 1858 // ToType have the same unqualified type (since we checked 1859 // qualifiers above), then this is a qualification conversion. 1860 return UnwrappedAnyPointer && Context.hasSameUnqualifiedType(FromType,ToType); 1861} 1862 1863/// Determines whether there is a user-defined conversion sequence 1864/// (C++ [over.ics.user]) that converts expression From to the type 1865/// ToType. If such a conversion exists, User will contain the 1866/// user-defined conversion sequence that performs such a conversion 1867/// and this routine will return true. Otherwise, this routine returns 1868/// false and User is unspecified. 1869/// 1870/// \param AllowExplicit true if the conversion should consider C++0x 1871/// "explicit" conversion functions as well as non-explicit conversion 1872/// functions (C++0x [class.conv.fct]p2). 1873OverloadingResult Sema::IsUserDefinedConversion(Expr *From, QualType ToType, 1874 UserDefinedConversionSequence& User, 1875 OverloadCandidateSet& CandidateSet, 1876 bool AllowExplicit) { 1877 // Whether we will only visit constructors. 1878 bool ConstructorsOnly = false; 1879 1880 // If the type we are conversion to is a class type, enumerate its 1881 // constructors. 1882 if (const RecordType *ToRecordType = ToType->getAs<RecordType>()) { 1883 // C++ [over.match.ctor]p1: 1884 // When objects of class type are direct-initialized (8.5), or 1885 // copy-initialized from an expression of the same or a 1886 // derived class type (8.5), overload resolution selects the 1887 // constructor. [...] For copy-initialization, the candidate 1888 // functions are all the converting constructors (12.3.1) of 1889 // that class. The argument list is the expression-list within 1890 // the parentheses of the initializer. 1891 if (Context.hasSameUnqualifiedType(ToType, From->getType()) || 1892 (From->getType()->getAs<RecordType>() && 1893 IsDerivedFrom(From->getType(), ToType))) 1894 ConstructorsOnly = true; 1895 1896 if (RequireCompleteType(From->getLocStart(), ToType, PDiag())) { 1897 // We're not going to find any constructors. 1898 } else if (CXXRecordDecl *ToRecordDecl 1899 = dyn_cast<CXXRecordDecl>(ToRecordType->getDecl())) { 1900 DeclContext::lookup_iterator Con, ConEnd; 1901 for (llvm::tie(Con, ConEnd) = LookupConstructors(ToRecordDecl); 1902 Con != ConEnd; ++Con) { 1903 NamedDecl *D = *Con; 1904 DeclAccessPair FoundDecl = DeclAccessPair::make(D, D->getAccess()); 1905 1906 // Find the constructor (which may be a template). 1907 CXXConstructorDecl *Constructor = 0; 1908 FunctionTemplateDecl *ConstructorTmpl 1909 = dyn_cast<FunctionTemplateDecl>(D); 1910 if (ConstructorTmpl) 1911 Constructor 1912 = cast<CXXConstructorDecl>(ConstructorTmpl->getTemplatedDecl()); 1913 else 1914 Constructor = cast<CXXConstructorDecl>(D); 1915 1916 if (!Constructor->isInvalidDecl() && 1917 Constructor->isConvertingConstructor(AllowExplicit)) { 1918 if (ConstructorTmpl) 1919 AddTemplateOverloadCandidate(ConstructorTmpl, FoundDecl, 1920 /*ExplicitArgs*/ 0, 1921 &From, 1, CandidateSet, 1922 /*SuppressUserConversions=*/!ConstructorsOnly); 1923 else 1924 // Allow one user-defined conversion when user specifies a 1925 // From->ToType conversion via an static cast (c-style, etc). 1926 AddOverloadCandidate(Constructor, FoundDecl, 1927 &From, 1, CandidateSet, 1928 /*SuppressUserConversions=*/!ConstructorsOnly); 1929 } 1930 } 1931 } 1932 } 1933 1934 // Enumerate conversion functions, if we're allowed to. 1935 if (ConstructorsOnly) { 1936 } else if (RequireCompleteType(From->getLocStart(), From->getType(), 1937 PDiag(0) << From->getSourceRange())) { 1938 // No conversion functions from incomplete types. 1939 } else if (const RecordType *FromRecordType 1940 = From->getType()->getAs<RecordType>()) { 1941 if (CXXRecordDecl *FromRecordDecl 1942 = dyn_cast<CXXRecordDecl>(FromRecordType->getDecl())) { 1943 // Add all of the conversion functions as candidates. 1944 const UnresolvedSetImpl *Conversions 1945 = FromRecordDecl->getVisibleConversionFunctions(); 1946 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 1947 E = Conversions->end(); I != E; ++I) { 1948 DeclAccessPair FoundDecl = I.getPair(); 1949 NamedDecl *D = FoundDecl.getDecl(); 1950 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext()); 1951 if (isa<UsingShadowDecl>(D)) 1952 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 1953 1954 CXXConversionDecl *Conv; 1955 FunctionTemplateDecl *ConvTemplate; 1956 if ((ConvTemplate = dyn_cast<FunctionTemplateDecl>(D))) 1957 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 1958 else 1959 Conv = cast<CXXConversionDecl>(D); 1960 1961 if (AllowExplicit || !Conv->isExplicit()) { 1962 if (ConvTemplate) 1963 AddTemplateConversionCandidate(ConvTemplate, FoundDecl, 1964 ActingContext, From, ToType, 1965 CandidateSet); 1966 else 1967 AddConversionCandidate(Conv, FoundDecl, ActingContext, 1968 From, ToType, CandidateSet); 1969 } 1970 } 1971 } 1972 } 1973 1974 OverloadCandidateSet::iterator Best; 1975 switch (BestViableFunction(CandidateSet, From->getLocStart(), Best)) { 1976 case OR_Success: 1977 // Record the standard conversion we used and the conversion function. 1978 if (CXXConstructorDecl *Constructor 1979 = dyn_cast<CXXConstructorDecl>(Best->Function)) { 1980 // C++ [over.ics.user]p1: 1981 // If the user-defined conversion is specified by a 1982 // constructor (12.3.1), the initial standard conversion 1983 // sequence converts the source type to the type required by 1984 // the argument of the constructor. 1985 // 1986 QualType ThisType = Constructor->getThisType(Context); 1987 if (Best->Conversions[0].isEllipsis()) 1988 User.EllipsisConversion = true; 1989 else { 1990 User.Before = Best->Conversions[0].Standard; 1991 User.EllipsisConversion = false; 1992 } 1993 User.ConversionFunction = Constructor; 1994 User.After.setAsIdentityConversion(); 1995 User.After.setFromType( 1996 ThisType->getAs<PointerType>()->getPointeeType()); 1997 User.After.setAllToTypes(ToType); 1998 return OR_Success; 1999 } else if (CXXConversionDecl *Conversion 2000 = dyn_cast<CXXConversionDecl>(Best->Function)) { 2001 // C++ [over.ics.user]p1: 2002 // 2003 // [...] If the user-defined conversion is specified by a 2004 // conversion function (12.3.2), the initial standard 2005 // conversion sequence converts the source type to the 2006 // implicit object parameter of the conversion function. 2007 User.Before = Best->Conversions[0].Standard; 2008 User.ConversionFunction = Conversion; 2009 User.EllipsisConversion = false; 2010 2011 // C++ [over.ics.user]p2: 2012 // The second standard conversion sequence converts the 2013 // result of the user-defined conversion to the target type 2014 // for the sequence. Since an implicit conversion sequence 2015 // is an initialization, the special rules for 2016 // initialization by user-defined conversion apply when 2017 // selecting the best user-defined conversion for a 2018 // user-defined conversion sequence (see 13.3.3 and 2019 // 13.3.3.1). 2020 User.After = Best->FinalConversion; 2021 return OR_Success; 2022 } else { 2023 assert(false && "Not a constructor or conversion function?"); 2024 return OR_No_Viable_Function; 2025 } 2026 2027 case OR_No_Viable_Function: 2028 return OR_No_Viable_Function; 2029 case OR_Deleted: 2030 // No conversion here! We're done. 2031 return OR_Deleted; 2032 2033 case OR_Ambiguous: 2034 return OR_Ambiguous; 2035 } 2036 2037 return OR_No_Viable_Function; 2038} 2039 2040bool 2041Sema::DiagnoseMultipleUserDefinedConversion(Expr *From, QualType ToType) { 2042 ImplicitConversionSequence ICS; 2043 OverloadCandidateSet CandidateSet(From->getExprLoc()); 2044 OverloadingResult OvResult = 2045 IsUserDefinedConversion(From, ToType, ICS.UserDefined, 2046 CandidateSet, false); 2047 if (OvResult == OR_Ambiguous) 2048 Diag(From->getSourceRange().getBegin(), 2049 diag::err_typecheck_ambiguous_condition) 2050 << From->getType() << ToType << From->getSourceRange(); 2051 else if (OvResult == OR_No_Viable_Function && !CandidateSet.empty()) 2052 Diag(From->getSourceRange().getBegin(), 2053 diag::err_typecheck_nonviable_condition) 2054 << From->getType() << ToType << From->getSourceRange(); 2055 else 2056 return false; 2057 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, &From, 1); 2058 return true; 2059} 2060 2061/// CompareImplicitConversionSequences - Compare two implicit 2062/// conversion sequences to determine whether one is better than the 2063/// other or if they are indistinguishable (C++ 13.3.3.2). 2064ImplicitConversionSequence::CompareKind 2065Sema::CompareImplicitConversionSequences(const ImplicitConversionSequence& ICS1, 2066 const ImplicitConversionSequence& ICS2) 2067{ 2068 // (C++ 13.3.3.2p2): When comparing the basic forms of implicit 2069 // conversion sequences (as defined in 13.3.3.1) 2070 // -- a standard conversion sequence (13.3.3.1.1) is a better 2071 // conversion sequence than a user-defined conversion sequence or 2072 // an ellipsis conversion sequence, and 2073 // -- a user-defined conversion sequence (13.3.3.1.2) is a better 2074 // conversion sequence than an ellipsis conversion sequence 2075 // (13.3.3.1.3). 2076 // 2077 // C++0x [over.best.ics]p10: 2078 // For the purpose of ranking implicit conversion sequences as 2079 // described in 13.3.3.2, the ambiguous conversion sequence is 2080 // treated as a user-defined sequence that is indistinguishable 2081 // from any other user-defined conversion sequence. 2082 if (ICS1.getKindRank() < ICS2.getKindRank()) 2083 return ImplicitConversionSequence::Better; 2084 else if (ICS2.getKindRank() < ICS1.getKindRank()) 2085 return ImplicitConversionSequence::Worse; 2086 2087 // The following checks require both conversion sequences to be of 2088 // the same kind. 2089 if (ICS1.getKind() != ICS2.getKind()) 2090 return ImplicitConversionSequence::Indistinguishable; 2091 2092 // Two implicit conversion sequences of the same form are 2093 // indistinguishable conversion sequences unless one of the 2094 // following rules apply: (C++ 13.3.3.2p3): 2095 if (ICS1.isStandard()) 2096 return CompareStandardConversionSequences(ICS1.Standard, ICS2.Standard); 2097 else if (ICS1.isUserDefined()) { 2098 // User-defined conversion sequence U1 is a better conversion 2099 // sequence than another user-defined conversion sequence U2 if 2100 // they contain the same user-defined conversion function or 2101 // constructor and if the second standard conversion sequence of 2102 // U1 is better than the second standard conversion sequence of 2103 // U2 (C++ 13.3.3.2p3). 2104 if (ICS1.UserDefined.ConversionFunction == 2105 ICS2.UserDefined.ConversionFunction) 2106 return CompareStandardConversionSequences(ICS1.UserDefined.After, 2107 ICS2.UserDefined.After); 2108 } 2109 2110 return ImplicitConversionSequence::Indistinguishable; 2111} 2112 2113static bool hasSimilarType(ASTContext &Context, QualType T1, QualType T2) { 2114 while (Context.UnwrapSimilarPointerTypes(T1, T2)) { 2115 Qualifiers Quals; 2116 T1 = Context.getUnqualifiedArrayType(T1, Quals); 2117 T2 = Context.getUnqualifiedArrayType(T2, Quals); 2118 } 2119 2120 return Context.hasSameUnqualifiedType(T1, T2); 2121} 2122 2123// Per 13.3.3.2p3, compare the given standard conversion sequences to 2124// determine if one is a proper subset of the other. 2125static ImplicitConversionSequence::CompareKind 2126compareStandardConversionSubsets(ASTContext &Context, 2127 const StandardConversionSequence& SCS1, 2128 const StandardConversionSequence& SCS2) { 2129 ImplicitConversionSequence::CompareKind Result 2130 = ImplicitConversionSequence::Indistinguishable; 2131 2132 // the identity conversion sequence is considered to be a subsequence of 2133 // any non-identity conversion sequence 2134 if (SCS1.ReferenceBinding == SCS2.ReferenceBinding) { 2135 if (SCS1.isIdentityConversion() && !SCS2.isIdentityConversion()) 2136 return ImplicitConversionSequence::Better; 2137 else if (!SCS1.isIdentityConversion() && SCS2.isIdentityConversion()) 2138 return ImplicitConversionSequence::Worse; 2139 } 2140 2141 if (SCS1.Second != SCS2.Second) { 2142 if (SCS1.Second == ICK_Identity) 2143 Result = ImplicitConversionSequence::Better; 2144 else if (SCS2.Second == ICK_Identity) 2145 Result = ImplicitConversionSequence::Worse; 2146 else 2147 return ImplicitConversionSequence::Indistinguishable; 2148 } else if (!hasSimilarType(Context, SCS1.getToType(1), SCS2.getToType(1))) 2149 return ImplicitConversionSequence::Indistinguishable; 2150 2151 if (SCS1.Third == SCS2.Third) { 2152 return Context.hasSameType(SCS1.getToType(2), SCS2.getToType(2))? Result 2153 : ImplicitConversionSequence::Indistinguishable; 2154 } 2155 2156 if (SCS1.Third == ICK_Identity) 2157 return Result == ImplicitConversionSequence::Worse 2158 ? ImplicitConversionSequence::Indistinguishable 2159 : ImplicitConversionSequence::Better; 2160 2161 if (SCS2.Third == ICK_Identity) 2162 return Result == ImplicitConversionSequence::Better 2163 ? ImplicitConversionSequence::Indistinguishable 2164 : ImplicitConversionSequence::Worse; 2165 2166 return ImplicitConversionSequence::Indistinguishable; 2167} 2168 2169/// CompareStandardConversionSequences - Compare two standard 2170/// conversion sequences to determine whether one is better than the 2171/// other or if they are indistinguishable (C++ 13.3.3.2p3). 2172ImplicitConversionSequence::CompareKind 2173Sema::CompareStandardConversionSequences(const StandardConversionSequence& SCS1, 2174 const StandardConversionSequence& SCS2) 2175{ 2176 // Standard conversion sequence S1 is a better conversion sequence 2177 // than standard conversion sequence S2 if (C++ 13.3.3.2p3): 2178 2179 // -- S1 is a proper subsequence of S2 (comparing the conversion 2180 // sequences in the canonical form defined by 13.3.3.1.1, 2181 // excluding any Lvalue Transformation; the identity conversion 2182 // sequence is considered to be a subsequence of any 2183 // non-identity conversion sequence) or, if not that, 2184 if (ImplicitConversionSequence::CompareKind CK 2185 = compareStandardConversionSubsets(Context, SCS1, SCS2)) 2186 return CK; 2187 2188 // -- the rank of S1 is better than the rank of S2 (by the rules 2189 // defined below), or, if not that, 2190 ImplicitConversionRank Rank1 = SCS1.getRank(); 2191 ImplicitConversionRank Rank2 = SCS2.getRank(); 2192 if (Rank1 < Rank2) 2193 return ImplicitConversionSequence::Better; 2194 else if (Rank2 < Rank1) 2195 return ImplicitConversionSequence::Worse; 2196 2197 // (C++ 13.3.3.2p4): Two conversion sequences with the same rank 2198 // are indistinguishable unless one of the following rules 2199 // applies: 2200 2201 // A conversion that is not a conversion of a pointer, or 2202 // pointer to member, to bool is better than another conversion 2203 // that is such a conversion. 2204 if (SCS1.isPointerConversionToBool() != SCS2.isPointerConversionToBool()) 2205 return SCS2.isPointerConversionToBool() 2206 ? ImplicitConversionSequence::Better 2207 : ImplicitConversionSequence::Worse; 2208 2209 // C++ [over.ics.rank]p4b2: 2210 // 2211 // If class B is derived directly or indirectly from class A, 2212 // conversion of B* to A* is better than conversion of B* to 2213 // void*, and conversion of A* to void* is better than conversion 2214 // of B* to void*. 2215 bool SCS1ConvertsToVoid 2216 = SCS1.isPointerConversionToVoidPointer(Context); 2217 bool SCS2ConvertsToVoid 2218 = SCS2.isPointerConversionToVoidPointer(Context); 2219 if (SCS1ConvertsToVoid != SCS2ConvertsToVoid) { 2220 // Exactly one of the conversion sequences is a conversion to 2221 // a void pointer; it's the worse conversion. 2222 return SCS2ConvertsToVoid ? ImplicitConversionSequence::Better 2223 : ImplicitConversionSequence::Worse; 2224 } else if (!SCS1ConvertsToVoid && !SCS2ConvertsToVoid) { 2225 // Neither conversion sequence converts to a void pointer; compare 2226 // their derived-to-base conversions. 2227 if (ImplicitConversionSequence::CompareKind DerivedCK 2228 = CompareDerivedToBaseConversions(SCS1, SCS2)) 2229 return DerivedCK; 2230 } else if (SCS1ConvertsToVoid && SCS2ConvertsToVoid) { 2231 // Both conversion sequences are conversions to void 2232 // pointers. Compare the source types to determine if there's an 2233 // inheritance relationship in their sources. 2234 QualType FromType1 = SCS1.getFromType(); 2235 QualType FromType2 = SCS2.getFromType(); 2236 2237 // Adjust the types we're converting from via the array-to-pointer 2238 // conversion, if we need to. 2239 if (SCS1.First == ICK_Array_To_Pointer) 2240 FromType1 = Context.getArrayDecayedType(FromType1); 2241 if (SCS2.First == ICK_Array_To_Pointer) 2242 FromType2 = Context.getArrayDecayedType(FromType2); 2243 2244 QualType FromPointee1 2245 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2246 QualType FromPointee2 2247 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2248 2249 if (IsDerivedFrom(FromPointee2, FromPointee1)) 2250 return ImplicitConversionSequence::Better; 2251 else if (IsDerivedFrom(FromPointee1, FromPointee2)) 2252 return ImplicitConversionSequence::Worse; 2253 2254 // Objective-C++: If one interface is more specific than the 2255 // other, it is the better one. 2256 const ObjCObjectType* FromIface1 = FromPointee1->getAs<ObjCObjectType>(); 2257 const ObjCObjectType* FromIface2 = FromPointee2->getAs<ObjCObjectType>(); 2258 if (FromIface1 && FromIface1) { 2259 if (Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 2260 return ImplicitConversionSequence::Better; 2261 else if (Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 2262 return ImplicitConversionSequence::Worse; 2263 } 2264 } 2265 2266 // Compare based on qualification conversions (C++ 13.3.3.2p3, 2267 // bullet 3). 2268 if (ImplicitConversionSequence::CompareKind QualCK 2269 = CompareQualificationConversions(SCS1, SCS2)) 2270 return QualCK; 2271 2272 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding) { 2273 // C++0x [over.ics.rank]p3b4: 2274 // -- S1 and S2 are reference bindings (8.5.3) and neither refers to an 2275 // implicit object parameter of a non-static member function declared 2276 // without a ref-qualifier, and S1 binds an rvalue reference to an 2277 // rvalue and S2 binds an lvalue reference. 2278 // FIXME: We don't know if we're dealing with the implicit object parameter, 2279 // or if the member function in this case has a ref qualifier. 2280 // (Of course, we don't have ref qualifiers yet.) 2281 if (SCS1.RRefBinding != SCS2.RRefBinding) 2282 return SCS1.RRefBinding ? ImplicitConversionSequence::Better 2283 : ImplicitConversionSequence::Worse; 2284 2285 // C++ [over.ics.rank]p3b4: 2286 // -- S1 and S2 are reference bindings (8.5.3), and the types to 2287 // which the references refer are the same type except for 2288 // top-level cv-qualifiers, and the type to which the reference 2289 // initialized by S2 refers is more cv-qualified than the type 2290 // to which the reference initialized by S1 refers. 2291 QualType T1 = SCS1.getToType(2); 2292 QualType T2 = SCS2.getToType(2); 2293 T1 = Context.getCanonicalType(T1); 2294 T2 = Context.getCanonicalType(T2); 2295 Qualifiers T1Quals, T2Quals; 2296 QualType UnqualT1 = Context.getUnqualifiedArrayType(T1, T1Quals); 2297 QualType UnqualT2 = Context.getUnqualifiedArrayType(T2, T2Quals); 2298 if (UnqualT1 == UnqualT2) { 2299 // If the type is an array type, promote the element qualifiers to the type 2300 // for comparison. 2301 if (isa<ArrayType>(T1) && T1Quals) 2302 T1 = Context.getQualifiedType(UnqualT1, T1Quals); 2303 if (isa<ArrayType>(T2) && T2Quals) 2304 T2 = Context.getQualifiedType(UnqualT2, T2Quals); 2305 if (T2.isMoreQualifiedThan(T1)) 2306 return ImplicitConversionSequence::Better; 2307 else if (T1.isMoreQualifiedThan(T2)) 2308 return ImplicitConversionSequence::Worse; 2309 } 2310 } 2311 2312 return ImplicitConversionSequence::Indistinguishable; 2313} 2314 2315/// CompareQualificationConversions - Compares two standard conversion 2316/// sequences to determine whether they can be ranked based on their 2317/// qualification conversions (C++ 13.3.3.2p3 bullet 3). 2318ImplicitConversionSequence::CompareKind 2319Sema::CompareQualificationConversions(const StandardConversionSequence& SCS1, 2320 const StandardConversionSequence& SCS2) { 2321 // C++ 13.3.3.2p3: 2322 // -- S1 and S2 differ only in their qualification conversion and 2323 // yield similar types T1 and T2 (C++ 4.4), respectively, and the 2324 // cv-qualification signature of type T1 is a proper subset of 2325 // the cv-qualification signature of type T2, and S1 is not the 2326 // deprecated string literal array-to-pointer conversion (4.2). 2327 if (SCS1.First != SCS2.First || SCS1.Second != SCS2.Second || 2328 SCS1.Third != SCS2.Third || SCS1.Third != ICK_Qualification) 2329 return ImplicitConversionSequence::Indistinguishable; 2330 2331 // FIXME: the example in the standard doesn't use a qualification 2332 // conversion (!) 2333 QualType T1 = SCS1.getToType(2); 2334 QualType T2 = SCS2.getToType(2); 2335 T1 = Context.getCanonicalType(T1); 2336 T2 = Context.getCanonicalType(T2); 2337 Qualifiers T1Quals, T2Quals; 2338 QualType UnqualT1 = Context.getUnqualifiedArrayType(T1, T1Quals); 2339 QualType UnqualT2 = Context.getUnqualifiedArrayType(T2, T2Quals); 2340 2341 // If the types are the same, we won't learn anything by unwrapped 2342 // them. 2343 if (UnqualT1 == UnqualT2) 2344 return ImplicitConversionSequence::Indistinguishable; 2345 2346 // If the type is an array type, promote the element qualifiers to the type 2347 // for comparison. 2348 if (isa<ArrayType>(T1) && T1Quals) 2349 T1 = Context.getQualifiedType(UnqualT1, T1Quals); 2350 if (isa<ArrayType>(T2) && T2Quals) 2351 T2 = Context.getQualifiedType(UnqualT2, T2Quals); 2352 2353 ImplicitConversionSequence::CompareKind Result 2354 = ImplicitConversionSequence::Indistinguishable; 2355 while (Context.UnwrapSimilarPointerTypes(T1, T2)) { 2356 // Within each iteration of the loop, we check the qualifiers to 2357 // determine if this still looks like a qualification 2358 // conversion. Then, if all is well, we unwrap one more level of 2359 // pointers or pointers-to-members and do it all again 2360 // until there are no more pointers or pointers-to-members left 2361 // to unwrap. This essentially mimics what 2362 // IsQualificationConversion does, but here we're checking for a 2363 // strict subset of qualifiers. 2364 if (T1.getCVRQualifiers() == T2.getCVRQualifiers()) 2365 // The qualifiers are the same, so this doesn't tell us anything 2366 // about how the sequences rank. 2367 ; 2368 else if (T2.isMoreQualifiedThan(T1)) { 2369 // T1 has fewer qualifiers, so it could be the better sequence. 2370 if (Result == ImplicitConversionSequence::Worse) 2371 // Neither has qualifiers that are a subset of the other's 2372 // qualifiers. 2373 return ImplicitConversionSequence::Indistinguishable; 2374 2375 Result = ImplicitConversionSequence::Better; 2376 } else if (T1.isMoreQualifiedThan(T2)) { 2377 // T2 has fewer qualifiers, so it could be the better sequence. 2378 if (Result == ImplicitConversionSequence::Better) 2379 // Neither has qualifiers that are a subset of the other's 2380 // qualifiers. 2381 return ImplicitConversionSequence::Indistinguishable; 2382 2383 Result = ImplicitConversionSequence::Worse; 2384 } else { 2385 // Qualifiers are disjoint. 2386 return ImplicitConversionSequence::Indistinguishable; 2387 } 2388 2389 // If the types after this point are equivalent, we're done. 2390 if (Context.hasSameUnqualifiedType(T1, T2)) 2391 break; 2392 } 2393 2394 // Check that the winning standard conversion sequence isn't using 2395 // the deprecated string literal array to pointer conversion. 2396 switch (Result) { 2397 case ImplicitConversionSequence::Better: 2398 if (SCS1.DeprecatedStringLiteralToCharPtr) 2399 Result = ImplicitConversionSequence::Indistinguishable; 2400 break; 2401 2402 case ImplicitConversionSequence::Indistinguishable: 2403 break; 2404 2405 case ImplicitConversionSequence::Worse: 2406 if (SCS2.DeprecatedStringLiteralToCharPtr) 2407 Result = ImplicitConversionSequence::Indistinguishable; 2408 break; 2409 } 2410 2411 return Result; 2412} 2413 2414/// CompareDerivedToBaseConversions - Compares two standard conversion 2415/// sequences to determine whether they can be ranked based on their 2416/// various kinds of derived-to-base conversions (C++ 2417/// [over.ics.rank]p4b3). As part of these checks, we also look at 2418/// conversions between Objective-C interface types. 2419ImplicitConversionSequence::CompareKind 2420Sema::CompareDerivedToBaseConversions(const StandardConversionSequence& SCS1, 2421 const StandardConversionSequence& SCS2) { 2422 QualType FromType1 = SCS1.getFromType(); 2423 QualType ToType1 = SCS1.getToType(1); 2424 QualType FromType2 = SCS2.getFromType(); 2425 QualType ToType2 = SCS2.getToType(1); 2426 2427 // Adjust the types we're converting from via the array-to-pointer 2428 // conversion, if we need to. 2429 if (SCS1.First == ICK_Array_To_Pointer) 2430 FromType1 = Context.getArrayDecayedType(FromType1); 2431 if (SCS2.First == ICK_Array_To_Pointer) 2432 FromType2 = Context.getArrayDecayedType(FromType2); 2433 2434 // Canonicalize all of the types. 2435 FromType1 = Context.getCanonicalType(FromType1); 2436 ToType1 = Context.getCanonicalType(ToType1); 2437 FromType2 = Context.getCanonicalType(FromType2); 2438 ToType2 = Context.getCanonicalType(ToType2); 2439 2440 // C++ [over.ics.rank]p4b3: 2441 // 2442 // If class B is derived directly or indirectly from class A and 2443 // class C is derived directly or indirectly from B, 2444 // 2445 // For Objective-C, we let A, B, and C also be Objective-C 2446 // interfaces. 2447 2448 // Compare based on pointer conversions. 2449 if (SCS1.Second == ICK_Pointer_Conversion && 2450 SCS2.Second == ICK_Pointer_Conversion && 2451 /*FIXME: Remove if Objective-C id conversions get their own rank*/ 2452 FromType1->isPointerType() && FromType2->isPointerType() && 2453 ToType1->isPointerType() && ToType2->isPointerType()) { 2454 QualType FromPointee1 2455 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2456 QualType ToPointee1 2457 = ToType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2458 QualType FromPointee2 2459 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2460 QualType ToPointee2 2461 = ToType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2462 2463 const ObjCObjectType* FromIface1 = FromPointee1->getAs<ObjCObjectType>(); 2464 const ObjCObjectType* FromIface2 = FromPointee2->getAs<ObjCObjectType>(); 2465 const ObjCObjectType* ToIface1 = ToPointee1->getAs<ObjCObjectType>(); 2466 const ObjCObjectType* ToIface2 = ToPointee2->getAs<ObjCObjectType>(); 2467 2468 // -- conversion of C* to B* is better than conversion of C* to A*, 2469 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 2470 if (IsDerivedFrom(ToPointee1, ToPointee2)) 2471 return ImplicitConversionSequence::Better; 2472 else if (IsDerivedFrom(ToPointee2, ToPointee1)) 2473 return ImplicitConversionSequence::Worse; 2474 2475 if (ToIface1 && ToIface2) { 2476 if (Context.canAssignObjCInterfaces(ToIface2, ToIface1)) 2477 return ImplicitConversionSequence::Better; 2478 else if (Context.canAssignObjCInterfaces(ToIface1, ToIface2)) 2479 return ImplicitConversionSequence::Worse; 2480 } 2481 } 2482 2483 // -- conversion of B* to A* is better than conversion of C* to A*, 2484 if (FromPointee1 != FromPointee2 && ToPointee1 == ToPointee2) { 2485 if (IsDerivedFrom(FromPointee2, FromPointee1)) 2486 return ImplicitConversionSequence::Better; 2487 else if (IsDerivedFrom(FromPointee1, FromPointee2)) 2488 return ImplicitConversionSequence::Worse; 2489 2490 if (FromIface1 && FromIface2) { 2491 if (Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 2492 return ImplicitConversionSequence::Better; 2493 else if (Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 2494 return ImplicitConversionSequence::Worse; 2495 } 2496 } 2497 } 2498 2499 // Ranking of member-pointer types. 2500 if (SCS1.Second == ICK_Pointer_Member && SCS2.Second == ICK_Pointer_Member && 2501 FromType1->isMemberPointerType() && FromType2->isMemberPointerType() && 2502 ToType1->isMemberPointerType() && ToType2->isMemberPointerType()) { 2503 const MemberPointerType * FromMemPointer1 = 2504 FromType1->getAs<MemberPointerType>(); 2505 const MemberPointerType * ToMemPointer1 = 2506 ToType1->getAs<MemberPointerType>(); 2507 const MemberPointerType * FromMemPointer2 = 2508 FromType2->getAs<MemberPointerType>(); 2509 const MemberPointerType * ToMemPointer2 = 2510 ToType2->getAs<MemberPointerType>(); 2511 const Type *FromPointeeType1 = FromMemPointer1->getClass(); 2512 const Type *ToPointeeType1 = ToMemPointer1->getClass(); 2513 const Type *FromPointeeType2 = FromMemPointer2->getClass(); 2514 const Type *ToPointeeType2 = ToMemPointer2->getClass(); 2515 QualType FromPointee1 = QualType(FromPointeeType1, 0).getUnqualifiedType(); 2516 QualType ToPointee1 = QualType(ToPointeeType1, 0).getUnqualifiedType(); 2517 QualType FromPointee2 = QualType(FromPointeeType2, 0).getUnqualifiedType(); 2518 QualType ToPointee2 = QualType(ToPointeeType2, 0).getUnqualifiedType(); 2519 // conversion of A::* to B::* is better than conversion of A::* to C::*, 2520 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 2521 if (IsDerivedFrom(ToPointee1, ToPointee2)) 2522 return ImplicitConversionSequence::Worse; 2523 else if (IsDerivedFrom(ToPointee2, ToPointee1)) 2524 return ImplicitConversionSequence::Better; 2525 } 2526 // conversion of B::* to C::* is better than conversion of A::* to C::* 2527 if (ToPointee1 == ToPointee2 && FromPointee1 != FromPointee2) { 2528 if (IsDerivedFrom(FromPointee1, FromPointee2)) 2529 return ImplicitConversionSequence::Better; 2530 else if (IsDerivedFrom(FromPointee2, FromPointee1)) 2531 return ImplicitConversionSequence::Worse; 2532 } 2533 } 2534 2535 if (SCS1.Second == ICK_Derived_To_Base) { 2536 // -- conversion of C to B is better than conversion of C to A, 2537 // -- binding of an expression of type C to a reference of type 2538 // B& is better than binding an expression of type C to a 2539 // reference of type A&, 2540 if (Context.hasSameUnqualifiedType(FromType1, FromType2) && 2541 !Context.hasSameUnqualifiedType(ToType1, ToType2)) { 2542 if (IsDerivedFrom(ToType1, ToType2)) 2543 return ImplicitConversionSequence::Better; 2544 else if (IsDerivedFrom(ToType2, ToType1)) 2545 return ImplicitConversionSequence::Worse; 2546 } 2547 2548 // -- conversion of B to A is better than conversion of C to A. 2549 // -- binding of an expression of type B to a reference of type 2550 // A& is better than binding an expression of type C to a 2551 // reference of type A&, 2552 if (!Context.hasSameUnqualifiedType(FromType1, FromType2) && 2553 Context.hasSameUnqualifiedType(ToType1, ToType2)) { 2554 if (IsDerivedFrom(FromType2, FromType1)) 2555 return ImplicitConversionSequence::Better; 2556 else if (IsDerivedFrom(FromType1, FromType2)) 2557 return ImplicitConversionSequence::Worse; 2558 } 2559 } 2560 2561 return ImplicitConversionSequence::Indistinguishable; 2562} 2563 2564/// CompareReferenceRelationship - Compare the two types T1 and T2 to 2565/// determine whether they are reference-related, 2566/// reference-compatible, reference-compatible with added 2567/// qualification, or incompatible, for use in C++ initialization by 2568/// reference (C++ [dcl.ref.init]p4). Neither type can be a reference 2569/// type, and the first type (T1) is the pointee type of the reference 2570/// type being initialized. 2571Sema::ReferenceCompareResult 2572Sema::CompareReferenceRelationship(SourceLocation Loc, 2573 QualType OrigT1, QualType OrigT2, 2574 bool& DerivedToBase) { 2575 assert(!OrigT1->isReferenceType() && 2576 "T1 must be the pointee type of the reference type"); 2577 assert(!OrigT2->isReferenceType() && "T2 cannot be a reference type"); 2578 2579 QualType T1 = Context.getCanonicalType(OrigT1); 2580 QualType T2 = Context.getCanonicalType(OrigT2); 2581 Qualifiers T1Quals, T2Quals; 2582 QualType UnqualT1 = Context.getUnqualifiedArrayType(T1, T1Quals); 2583 QualType UnqualT2 = Context.getUnqualifiedArrayType(T2, T2Quals); 2584 2585 // C++ [dcl.init.ref]p4: 2586 // Given types "cv1 T1" and "cv2 T2," "cv1 T1" is 2587 // reference-related to "cv2 T2" if T1 is the same type as T2, or 2588 // T1 is a base class of T2. 2589 if (UnqualT1 == UnqualT2) 2590 DerivedToBase = false; 2591 else if (!RequireCompleteType(Loc, OrigT2, PDiag()) && 2592 IsDerivedFrom(UnqualT2, UnqualT1)) 2593 DerivedToBase = true; 2594 else 2595 return Ref_Incompatible; 2596 2597 // At this point, we know that T1 and T2 are reference-related (at 2598 // least). 2599 2600 // If the type is an array type, promote the element qualifiers to the type 2601 // for comparison. 2602 if (isa<ArrayType>(T1) && T1Quals) 2603 T1 = Context.getQualifiedType(UnqualT1, T1Quals); 2604 if (isa<ArrayType>(T2) && T2Quals) 2605 T2 = Context.getQualifiedType(UnqualT2, T2Quals); 2606 2607 // C++ [dcl.init.ref]p4: 2608 // "cv1 T1" is reference-compatible with "cv2 T2" if T1 is 2609 // reference-related to T2 and cv1 is the same cv-qualification 2610 // as, or greater cv-qualification than, cv2. For purposes of 2611 // overload resolution, cases for which cv1 is greater 2612 // cv-qualification than cv2 are identified as 2613 // reference-compatible with added qualification (see 13.3.3.2). 2614 if (T1Quals.getCVRQualifiers() == T2Quals.getCVRQualifiers()) 2615 return Ref_Compatible; 2616 else if (T1.isMoreQualifiedThan(T2)) 2617 return Ref_Compatible_With_Added_Qualification; 2618 else 2619 return Ref_Related; 2620} 2621 2622/// \brief Look for a user-defined conversion to an lvalue reference-compatible 2623/// with DeclType. Return true if something definite is found. 2624static bool 2625FindConversionToLValue(Sema &S, ImplicitConversionSequence &ICS, 2626 QualType DeclType, SourceLocation DeclLoc, 2627 Expr *Init, QualType T2, bool AllowExplicit) { 2628 assert(T2->isRecordType() && "Can only find conversions of record types."); 2629 CXXRecordDecl *T2RecordDecl 2630 = dyn_cast<CXXRecordDecl>(T2->getAs<RecordType>()->getDecl()); 2631 2632 OverloadCandidateSet CandidateSet(DeclLoc); 2633 const UnresolvedSetImpl *Conversions 2634 = T2RecordDecl->getVisibleConversionFunctions(); 2635 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 2636 E = Conversions->end(); I != E; ++I) { 2637 NamedDecl *D = *I; 2638 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(D->getDeclContext()); 2639 if (isa<UsingShadowDecl>(D)) 2640 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 2641 2642 FunctionTemplateDecl *ConvTemplate 2643 = dyn_cast<FunctionTemplateDecl>(D); 2644 CXXConversionDecl *Conv; 2645 if (ConvTemplate) 2646 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 2647 else 2648 Conv = cast<CXXConversionDecl>(D); 2649 2650 // If the conversion function doesn't return a reference type, 2651 // it can't be considered for this conversion. An rvalue reference 2652 // is only acceptable if its referencee is a function type. 2653 const ReferenceType *RefType = 2654 Conv->getConversionType()->getAs<ReferenceType>(); 2655 if (RefType && (RefType->isLValueReferenceType() || 2656 RefType->getPointeeType()->isFunctionType()) && 2657 (AllowExplicit || !Conv->isExplicit())) { 2658 if (ConvTemplate) 2659 S.AddTemplateConversionCandidate(ConvTemplate, I.getPair(), ActingDC, 2660 Init, DeclType, CandidateSet); 2661 else 2662 S.AddConversionCandidate(Conv, I.getPair(), ActingDC, Init, 2663 DeclType, CandidateSet); 2664 } 2665 } 2666 2667 OverloadCandidateSet::iterator Best; 2668 switch (S.BestViableFunction(CandidateSet, DeclLoc, Best)) { 2669 case OR_Success: 2670 // C++ [over.ics.ref]p1: 2671 // 2672 // [...] If the parameter binds directly to the result of 2673 // applying a conversion function to the argument 2674 // expression, the implicit conversion sequence is a 2675 // user-defined conversion sequence (13.3.3.1.2), with the 2676 // second standard conversion sequence either an identity 2677 // conversion or, if the conversion function returns an 2678 // entity of a type that is a derived class of the parameter 2679 // type, a derived-to-base Conversion. 2680 if (!Best->FinalConversion.DirectBinding) 2681 return false; 2682 2683 ICS.setUserDefined(); 2684 ICS.UserDefined.Before = Best->Conversions[0].Standard; 2685 ICS.UserDefined.After = Best->FinalConversion; 2686 ICS.UserDefined.ConversionFunction = Best->Function; 2687 ICS.UserDefined.EllipsisConversion = false; 2688 assert(ICS.UserDefined.After.ReferenceBinding && 2689 ICS.UserDefined.After.DirectBinding && 2690 "Expected a direct reference binding!"); 2691 return true; 2692 2693 case OR_Ambiguous: 2694 ICS.setAmbiguous(); 2695 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 2696 Cand != CandidateSet.end(); ++Cand) 2697 if (Cand->Viable) 2698 ICS.Ambiguous.addConversion(Cand->Function); 2699 return true; 2700 2701 case OR_No_Viable_Function: 2702 case OR_Deleted: 2703 // There was no suitable conversion, or we found a deleted 2704 // conversion; continue with other checks. 2705 return false; 2706 } 2707 2708 return false; 2709} 2710 2711/// \brief Compute an implicit conversion sequence for reference 2712/// initialization. 2713static ImplicitConversionSequence 2714TryReferenceInit(Sema &S, Expr *&Init, QualType DeclType, 2715 SourceLocation DeclLoc, 2716 bool SuppressUserConversions, 2717 bool AllowExplicit) { 2718 assert(DeclType->isReferenceType() && "Reference init needs a reference"); 2719 2720 // Most paths end in a failed conversion. 2721 ImplicitConversionSequence ICS; 2722 ICS.setBad(BadConversionSequence::no_conversion, Init, DeclType); 2723 2724 QualType T1 = DeclType->getAs<ReferenceType>()->getPointeeType(); 2725 QualType T2 = Init->getType(); 2726 2727 // If the initializer is the address of an overloaded function, try 2728 // to resolve the overloaded function. If all goes well, T2 is the 2729 // type of the resulting function. 2730 if (S.Context.getCanonicalType(T2) == S.Context.OverloadTy) { 2731 DeclAccessPair Found; 2732 if (FunctionDecl *Fn = S.ResolveAddressOfOverloadedFunction(Init, DeclType, 2733 false, Found)) 2734 T2 = Fn->getType(); 2735 } 2736 2737 // Compute some basic properties of the types and the initializer. 2738 bool isRValRef = DeclType->isRValueReferenceType(); 2739 bool DerivedToBase = false; 2740 Expr::Classification InitCategory = Init->Classify(S.Context); 2741 Sema::ReferenceCompareResult RefRelationship 2742 = S.CompareReferenceRelationship(DeclLoc, T1, T2, DerivedToBase); 2743 2744 2745 // C++0x [dcl.init.ref]p5: 2746 // A reference to type "cv1 T1" is initialized by an expression 2747 // of type "cv2 T2" as follows: 2748 2749 // -- If reference is an lvalue reference and the initializer expression 2750 // The next bullet point (T1 is a function) is pretty much equivalent to this 2751 // one, so it's handled here. 2752 if (!isRValRef || T1->isFunctionType()) { 2753 // -- is an lvalue (but is not a bit-field), and "cv1 T1" is 2754 // reference-compatible with "cv2 T2," or 2755 // 2756 // Per C++ [over.ics.ref]p4, we don't check the bit-field property here. 2757 if (InitCategory.isLValue() && 2758 RefRelationship >= Sema::Ref_Compatible_With_Added_Qualification) { 2759 // C++ [over.ics.ref]p1: 2760 // When a parameter of reference type binds directly (8.5.3) 2761 // to an argument expression, the implicit conversion sequence 2762 // is the identity conversion, unless the argument expression 2763 // has a type that is a derived class of the parameter type, 2764 // in which case the implicit conversion sequence is a 2765 // derived-to-base Conversion (13.3.3.1). 2766 ICS.setStandard(); 2767 ICS.Standard.First = ICK_Identity; 2768 ICS.Standard.Second = DerivedToBase? ICK_Derived_To_Base : ICK_Identity; 2769 ICS.Standard.Third = ICK_Identity; 2770 ICS.Standard.FromTypePtr = T2.getAsOpaquePtr(); 2771 ICS.Standard.setToType(0, T2); 2772 ICS.Standard.setToType(1, T1); 2773 ICS.Standard.setToType(2, T1); 2774 ICS.Standard.ReferenceBinding = true; 2775 ICS.Standard.DirectBinding = true; 2776 ICS.Standard.RRefBinding = isRValRef; 2777 ICS.Standard.CopyConstructor = 0; 2778 2779 // Nothing more to do: the inaccessibility/ambiguity check for 2780 // derived-to-base conversions is suppressed when we're 2781 // computing the implicit conversion sequence (C++ 2782 // [over.best.ics]p2). 2783 return ICS; 2784 } 2785 2786 // -- has a class type (i.e., T2 is a class type), where T1 is 2787 // not reference-related to T2, and can be implicitly 2788 // converted to an lvalue of type "cv3 T3," where "cv1 T1" 2789 // is reference-compatible with "cv3 T3" 92) (this 2790 // conversion is selected by enumerating the applicable 2791 // conversion functions (13.3.1.6) and choosing the best 2792 // one through overload resolution (13.3)), 2793 if (!SuppressUserConversions && T2->isRecordType() && 2794 !S.RequireCompleteType(DeclLoc, T2, 0) && 2795 RefRelationship == Sema::Ref_Incompatible) { 2796 if (FindConversionToLValue(S, ICS, DeclType, DeclLoc, 2797 Init, T2, AllowExplicit)) 2798 return ICS; 2799 } 2800 } 2801 2802 // -- Otherwise, the reference shall be an lvalue reference to a 2803 // non-volatile const type (i.e., cv1 shall be const), or the reference 2804 // shall be an rvalue reference and the initializer expression shall be 2805 // an rvalue or have a function type. 2806 // 2807 // We actually handle one oddity of C++ [over.ics.ref] at this 2808 // point, which is that, due to p2 (which short-circuits reference 2809 // binding by only attempting a simple conversion for non-direct 2810 // bindings) and p3's strange wording, we allow a const volatile 2811 // reference to bind to an rvalue. Hence the check for the presence 2812 // of "const" rather than checking for "const" being the only 2813 // qualifier. 2814 // This is also the point where rvalue references and lvalue inits no longer 2815 // go together. 2816 if ((!isRValRef && !T1.isConstQualified()) || 2817 (isRValRef && InitCategory.isLValue())) 2818 return ICS; 2819 2820 // -- If T1 is a function type, then 2821 // -- if T2 is the same type as T1, the reference is bound to the 2822 // initializer expression lvalue; 2823 // -- if T2 is a class type and the initializer expression can be 2824 // implicitly converted to an lvalue of type T1 [...], the 2825 // reference is bound to the function lvalue that is the result 2826 // of the conversion; 2827 // This is the same as for the lvalue case above, so it was handled there. 2828 // -- otherwise, the program is ill-formed. 2829 // This is the one difference to the lvalue case. 2830 if (T1->isFunctionType()) 2831 return ICS; 2832 2833 // -- Otherwise, if T2 is a class type and 2834 // -- the initializer expression is an rvalue and "cv1 T1" 2835 // is reference-compatible with "cv2 T2," or 2836 // 2837 // -- T1 is not reference-related to T2 and the initializer 2838 // expression can be implicitly converted to an rvalue 2839 // of type "cv3 T3" (this conversion is selected by 2840 // enumerating the applicable conversion functions 2841 // (13.3.1.6) and choosing the best one through overload 2842 // resolution (13.3)), 2843 // 2844 // then the reference is bound to the initializer 2845 // expression rvalue in the first case and to the object 2846 // that is the result of the conversion in the second case 2847 // (or, in either case, to the appropriate base class 2848 // subobject of the object). 2849 // 2850 // We're only checking the first case here, which is a direct 2851 // binding in C++0x but not in C++03. 2852 if (InitCategory.isRValue() && T2->isRecordType() && 2853 RefRelationship >= Sema::Ref_Compatible_With_Added_Qualification) { 2854 ICS.setStandard(); 2855 ICS.Standard.First = ICK_Identity; 2856 ICS.Standard.Second = DerivedToBase? ICK_Derived_To_Base : ICK_Identity; 2857 ICS.Standard.Third = ICK_Identity; 2858 ICS.Standard.FromTypePtr = T2.getAsOpaquePtr(); 2859 ICS.Standard.setToType(0, T2); 2860 ICS.Standard.setToType(1, T1); 2861 ICS.Standard.setToType(2, T1); 2862 ICS.Standard.ReferenceBinding = true; 2863 ICS.Standard.DirectBinding = S.getLangOptions().CPlusPlus0x; 2864 ICS.Standard.RRefBinding = isRValRef; 2865 ICS.Standard.CopyConstructor = 0; 2866 return ICS; 2867 } 2868 2869 // -- Otherwise, a temporary of type "cv1 T1" is created and 2870 // initialized from the initializer expression using the 2871 // rules for a non-reference copy initialization (8.5). The 2872 // reference is then bound to the temporary. If T1 is 2873 // reference-related to T2, cv1 must be the same 2874 // cv-qualification as, or greater cv-qualification than, 2875 // cv2; otherwise, the program is ill-formed. 2876 if (RefRelationship == Sema::Ref_Related) { 2877 // If cv1 == cv2 or cv1 is a greater cv-qualified than cv2, then 2878 // we would be reference-compatible or reference-compatible with 2879 // added qualification. But that wasn't the case, so the reference 2880 // initialization fails. 2881 return ICS; 2882 } 2883 2884 // If at least one of the types is a class type, the types are not 2885 // related, and we aren't allowed any user conversions, the 2886 // reference binding fails. This case is important for breaking 2887 // recursion, since TryImplicitConversion below will attempt to 2888 // create a temporary through the use of a copy constructor. 2889 if (SuppressUserConversions && RefRelationship == Sema::Ref_Incompatible && 2890 (T1->isRecordType() || T2->isRecordType())) 2891 return ICS; 2892 2893 // C++ [over.ics.ref]p2: 2894 // When a parameter of reference type is not bound directly to 2895 // an argument expression, the conversion sequence is the one 2896 // required to convert the argument expression to the 2897 // underlying type of the reference according to 2898 // 13.3.3.1. Conceptually, this conversion sequence corresponds 2899 // to copy-initializing a temporary of the underlying type with 2900 // the argument expression. Any difference in top-level 2901 // cv-qualification is subsumed by the initialization itself 2902 // and does not constitute a conversion. 2903 ICS = S.TryImplicitConversion(Init, T1, SuppressUserConversions, 2904 /*AllowExplicit=*/false, 2905 /*InOverloadResolution=*/false); 2906 2907 // Of course, that's still a reference binding. 2908 if (ICS.isStandard()) { 2909 ICS.Standard.ReferenceBinding = true; 2910 ICS.Standard.RRefBinding = isRValRef; 2911 } else if (ICS.isUserDefined()) { 2912 ICS.UserDefined.After.ReferenceBinding = true; 2913 ICS.UserDefined.After.RRefBinding = isRValRef; 2914 } 2915 return ICS; 2916} 2917 2918/// TryCopyInitialization - Try to copy-initialize a value of type 2919/// ToType from the expression From. Return the implicit conversion 2920/// sequence required to pass this argument, which may be a bad 2921/// conversion sequence (meaning that the argument cannot be passed to 2922/// a parameter of this type). If @p SuppressUserConversions, then we 2923/// do not permit any user-defined conversion sequences. 2924static ImplicitConversionSequence 2925TryCopyInitialization(Sema &S, Expr *From, QualType ToType, 2926 bool SuppressUserConversions, 2927 bool InOverloadResolution) { 2928 if (ToType->isReferenceType()) 2929 return TryReferenceInit(S, From, ToType, 2930 /*FIXME:*/From->getLocStart(), 2931 SuppressUserConversions, 2932 /*AllowExplicit=*/false); 2933 2934 return S.TryImplicitConversion(From, ToType, 2935 SuppressUserConversions, 2936 /*AllowExplicit=*/false, 2937 InOverloadResolution); 2938} 2939 2940/// TryObjectArgumentInitialization - Try to initialize the object 2941/// parameter of the given member function (@c Method) from the 2942/// expression @p From. 2943ImplicitConversionSequence 2944Sema::TryObjectArgumentInitialization(QualType OrigFromType, 2945 CXXMethodDecl *Method, 2946 CXXRecordDecl *ActingContext) { 2947 QualType ClassType = Context.getTypeDeclType(ActingContext); 2948 // [class.dtor]p2: A destructor can be invoked for a const, volatile or 2949 // const volatile object. 2950 unsigned Quals = isa<CXXDestructorDecl>(Method) ? 2951 Qualifiers::Const | Qualifiers::Volatile : Method->getTypeQualifiers(); 2952 QualType ImplicitParamType = Context.getCVRQualifiedType(ClassType, Quals); 2953 2954 // Set up the conversion sequence as a "bad" conversion, to allow us 2955 // to exit early. 2956 ImplicitConversionSequence ICS; 2957 2958 // We need to have an object of class type. 2959 QualType FromType = OrigFromType; 2960 if (const PointerType *PT = FromType->getAs<PointerType>()) 2961 FromType = PT->getPointeeType(); 2962 2963 assert(FromType->isRecordType()); 2964 2965 // The implicit object parameter is has the type "reference to cv X", 2966 // where X is the class of which the function is a member 2967 // (C++ [over.match.funcs]p4). However, when finding an implicit 2968 // conversion sequence for the argument, we are not allowed to 2969 // create temporaries or perform user-defined conversions 2970 // (C++ [over.match.funcs]p5). We perform a simplified version of 2971 // reference binding here, that allows class rvalues to bind to 2972 // non-constant references. 2973 2974 // First check the qualifiers. We don't care about lvalue-vs-rvalue 2975 // with the implicit object parameter (C++ [over.match.funcs]p5). 2976 QualType FromTypeCanon = Context.getCanonicalType(FromType); 2977 if (ImplicitParamType.getCVRQualifiers() 2978 != FromTypeCanon.getLocalCVRQualifiers() && 2979 !ImplicitParamType.isAtLeastAsQualifiedAs(FromTypeCanon)) { 2980 ICS.setBad(BadConversionSequence::bad_qualifiers, 2981 OrigFromType, ImplicitParamType); 2982 return ICS; 2983 } 2984 2985 // Check that we have either the same type or a derived type. It 2986 // affects the conversion rank. 2987 QualType ClassTypeCanon = Context.getCanonicalType(ClassType); 2988 ImplicitConversionKind SecondKind; 2989 if (ClassTypeCanon == FromTypeCanon.getLocalUnqualifiedType()) { 2990 SecondKind = ICK_Identity; 2991 } else if (IsDerivedFrom(FromType, ClassType)) 2992 SecondKind = ICK_Derived_To_Base; 2993 else { 2994 ICS.setBad(BadConversionSequence::unrelated_class, 2995 FromType, ImplicitParamType); 2996 return ICS; 2997 } 2998 2999 // Success. Mark this as a reference binding. 3000 ICS.setStandard(); 3001 ICS.Standard.setAsIdentityConversion(); 3002 ICS.Standard.Second = SecondKind; 3003 ICS.Standard.setFromType(FromType); 3004 ICS.Standard.setAllToTypes(ImplicitParamType); 3005 ICS.Standard.ReferenceBinding = true; 3006 ICS.Standard.DirectBinding = true; 3007 ICS.Standard.RRefBinding = false; 3008 return ICS; 3009} 3010 3011/// PerformObjectArgumentInitialization - Perform initialization of 3012/// the implicit object parameter for the given Method with the given 3013/// expression. 3014bool 3015Sema::PerformObjectArgumentInitialization(Expr *&From, 3016 NestedNameSpecifier *Qualifier, 3017 NamedDecl *FoundDecl, 3018 CXXMethodDecl *Method) { 3019 QualType FromRecordType, DestType; 3020 QualType ImplicitParamRecordType = 3021 Method->getThisType(Context)->getAs<PointerType>()->getPointeeType(); 3022 3023 if (const PointerType *PT = From->getType()->getAs<PointerType>()) { 3024 FromRecordType = PT->getPointeeType(); 3025 DestType = Method->getThisType(Context); 3026 } else { 3027 FromRecordType = From->getType(); 3028 DestType = ImplicitParamRecordType; 3029 } 3030 3031 // Note that we always use the true parent context when performing 3032 // the actual argument initialization. 3033 ImplicitConversionSequence ICS 3034 = TryObjectArgumentInitialization(From->getType(), Method, 3035 Method->getParent()); 3036 if (ICS.isBad()) 3037 return Diag(From->getSourceRange().getBegin(), 3038 diag::err_implicit_object_parameter_init) 3039 << ImplicitParamRecordType << FromRecordType << From->getSourceRange(); 3040 3041 if (ICS.Standard.Second == ICK_Derived_To_Base) 3042 return PerformObjectMemberConversion(From, Qualifier, FoundDecl, Method); 3043 3044 if (!Context.hasSameType(From->getType(), DestType)) 3045 ImpCastExprToType(From, DestType, CastExpr::CK_NoOp, 3046 From->getType()->isPointerType() ? 3047 ImplicitCastExpr::RValue : ImplicitCastExpr::LValue); 3048 return false; 3049} 3050 3051/// TryContextuallyConvertToBool - Attempt to contextually convert the 3052/// expression From to bool (C++0x [conv]p3). 3053ImplicitConversionSequence Sema::TryContextuallyConvertToBool(Expr *From) { 3054 // FIXME: This is pretty broken. 3055 return TryImplicitConversion(From, Context.BoolTy, 3056 // FIXME: Are these flags correct? 3057 /*SuppressUserConversions=*/false, 3058 /*AllowExplicit=*/true, 3059 /*InOverloadResolution=*/false); 3060} 3061 3062/// PerformContextuallyConvertToBool - Perform a contextual conversion 3063/// of the expression From to bool (C++0x [conv]p3). 3064bool Sema::PerformContextuallyConvertToBool(Expr *&From) { 3065 ImplicitConversionSequence ICS = TryContextuallyConvertToBool(From); 3066 if (!ICS.isBad()) 3067 return PerformImplicitConversion(From, Context.BoolTy, ICS, AA_Converting); 3068 3069 if (!DiagnoseMultipleUserDefinedConversion(From, Context.BoolTy)) 3070 return Diag(From->getSourceRange().getBegin(), 3071 diag::err_typecheck_bool_condition) 3072 << From->getType() << From->getSourceRange(); 3073 return true; 3074} 3075 3076/// TryContextuallyConvertToObjCId - Attempt to contextually convert the 3077/// expression From to 'id'. 3078ImplicitConversionSequence Sema::TryContextuallyConvertToObjCId(Expr *From) { 3079 QualType Ty = Context.getObjCIdType(); 3080 return TryImplicitConversion(From, Ty, 3081 // FIXME: Are these flags correct? 3082 /*SuppressUserConversions=*/false, 3083 /*AllowExplicit=*/true, 3084 /*InOverloadResolution=*/false); 3085} 3086 3087/// PerformContextuallyConvertToObjCId - Perform a contextual conversion 3088/// of the expression From to 'id'. 3089bool Sema::PerformContextuallyConvertToObjCId(Expr *&From) { 3090 QualType Ty = Context.getObjCIdType(); 3091 ImplicitConversionSequence ICS = TryContextuallyConvertToObjCId(From); 3092 if (!ICS.isBad()) 3093 return PerformImplicitConversion(From, Ty, ICS, AA_Converting); 3094 return true; 3095} 3096 3097/// \brief Attempt to convert the given expression to an integral or 3098/// enumeration type. 3099/// 3100/// This routine will attempt to convert an expression of class type to an 3101/// integral or enumeration type, if that class type only has a single 3102/// conversion to an integral or enumeration type. 3103/// 3104/// \param Loc The source location of the construct that requires the 3105/// conversion. 3106/// 3107/// \param FromE The expression we're converting from. 3108/// 3109/// \param NotIntDiag The diagnostic to be emitted if the expression does not 3110/// have integral or enumeration type. 3111/// 3112/// \param IncompleteDiag The diagnostic to be emitted if the expression has 3113/// incomplete class type. 3114/// 3115/// \param ExplicitConvDiag The diagnostic to be emitted if we're calling an 3116/// explicit conversion function (because no implicit conversion functions 3117/// were available). This is a recovery mode. 3118/// 3119/// \param ExplicitConvNote The note to be emitted with \p ExplicitConvDiag, 3120/// showing which conversion was picked. 3121/// 3122/// \param AmbigDiag The diagnostic to be emitted if there is more than one 3123/// conversion function that could convert to integral or enumeration type. 3124/// 3125/// \param AmbigNote The note to be emitted with \p AmbigDiag for each 3126/// usable conversion function. 3127/// 3128/// \param ConvDiag The diagnostic to be emitted if we are calling a conversion 3129/// function, which may be an extension in this case. 3130/// 3131/// \returns The expression, converted to an integral or enumeration type if 3132/// successful. 3133Sema::OwningExprResult 3134Sema::ConvertToIntegralOrEnumerationType(SourceLocation Loc, ExprArg FromE, 3135 const PartialDiagnostic &NotIntDiag, 3136 const PartialDiagnostic &IncompleteDiag, 3137 const PartialDiagnostic &ExplicitConvDiag, 3138 const PartialDiagnostic &ExplicitConvNote, 3139 const PartialDiagnostic &AmbigDiag, 3140 const PartialDiagnostic &AmbigNote, 3141 const PartialDiagnostic &ConvDiag) { 3142 Expr *From = static_cast<Expr *>(FromE.get()); 3143 3144 // We can't perform any more checking for type-dependent expressions. 3145 if (From->isTypeDependent()) 3146 return move(FromE); 3147 3148 // If the expression already has integral or enumeration type, we're golden. 3149 QualType T = From->getType(); 3150 if (T->isIntegralOrEnumerationType()) 3151 return move(FromE); 3152 3153 // FIXME: Check for missing '()' if T is a function type? 3154 3155 // If we don't have a class type in C++, there's no way we can get an 3156 // expression of integral or enumeration type. 3157 const RecordType *RecordTy = T->getAs<RecordType>(); 3158 if (!RecordTy || !getLangOptions().CPlusPlus) { 3159 Diag(Loc, NotIntDiag) 3160 << T << From->getSourceRange(); 3161 return move(FromE); 3162 } 3163 3164 // We must have a complete class type. 3165 if (RequireCompleteType(Loc, T, IncompleteDiag)) 3166 return move(FromE); 3167 3168 // Look for a conversion to an integral or enumeration type. 3169 UnresolvedSet<4> ViableConversions; 3170 UnresolvedSet<4> ExplicitConversions; 3171 const UnresolvedSetImpl *Conversions 3172 = cast<CXXRecordDecl>(RecordTy->getDecl())->getVisibleConversionFunctions(); 3173 3174 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 3175 E = Conversions->end(); 3176 I != E; 3177 ++I) { 3178 if (CXXConversionDecl *Conversion 3179 = dyn_cast<CXXConversionDecl>((*I)->getUnderlyingDecl())) 3180 if (Conversion->getConversionType().getNonReferenceType() 3181 ->isIntegralOrEnumerationType()) { 3182 if (Conversion->isExplicit()) 3183 ExplicitConversions.addDecl(I.getDecl(), I.getAccess()); 3184 else 3185 ViableConversions.addDecl(I.getDecl(), I.getAccess()); 3186 } 3187 } 3188 3189 switch (ViableConversions.size()) { 3190 case 0: 3191 if (ExplicitConversions.size() == 1) { 3192 DeclAccessPair Found = ExplicitConversions[0]; 3193 CXXConversionDecl *Conversion 3194 = cast<CXXConversionDecl>(Found->getUnderlyingDecl()); 3195 3196 // The user probably meant to invoke the given explicit 3197 // conversion; use it. 3198 QualType ConvTy 3199 = Conversion->getConversionType().getNonReferenceType(); 3200 std::string TypeStr; 3201 ConvTy.getAsStringInternal(TypeStr, Context.PrintingPolicy); 3202 3203 Diag(Loc, ExplicitConvDiag) 3204 << T << ConvTy 3205 << FixItHint::CreateInsertion(From->getLocStart(), 3206 "static_cast<" + TypeStr + ">(") 3207 << FixItHint::CreateInsertion(PP.getLocForEndOfToken(From->getLocEnd()), 3208 ")"); 3209 Diag(Conversion->getLocation(), ExplicitConvNote) 3210 << ConvTy->isEnumeralType() << ConvTy; 3211 3212 // If we aren't in a SFINAE context, build a call to the 3213 // explicit conversion function. 3214 if (isSFINAEContext()) 3215 return ExprError(); 3216 3217 CheckMemberOperatorAccess(From->getExprLoc(), From, 0, Found); 3218 From = BuildCXXMemberCallExpr(FromE.takeAs<Expr>(), Found, Conversion); 3219 FromE = Owned(From); 3220 } 3221 3222 // We'll complain below about a non-integral condition type. 3223 break; 3224 3225 case 1: { 3226 // Apply this conversion. 3227 DeclAccessPair Found = ViableConversions[0]; 3228 CheckMemberOperatorAccess(From->getExprLoc(), From, 0, Found); 3229 3230 CXXConversionDecl *Conversion 3231 = cast<CXXConversionDecl>(Found->getUnderlyingDecl()); 3232 QualType ConvTy 3233 = Conversion->getConversionType().getNonReferenceType(); 3234 if (ConvDiag.getDiagID()) { 3235 if (isSFINAEContext()) 3236 return ExprError(); 3237 3238 Diag(Loc, ConvDiag) 3239 << T << ConvTy->isEnumeralType() << ConvTy << From->getSourceRange(); 3240 } 3241 3242 From = BuildCXXMemberCallExpr(FromE.takeAs<Expr>(), Found, 3243 cast<CXXConversionDecl>(Found->getUnderlyingDecl())); 3244 FromE = Owned(From); 3245 break; 3246 } 3247 3248 default: 3249 Diag(Loc, AmbigDiag) 3250 << T << From->getSourceRange(); 3251 for (unsigned I = 0, N = ViableConversions.size(); I != N; ++I) { 3252 CXXConversionDecl *Conv 3253 = cast<CXXConversionDecl>(ViableConversions[I]->getUnderlyingDecl()); 3254 QualType ConvTy = Conv->getConversionType().getNonReferenceType(); 3255 Diag(Conv->getLocation(), AmbigNote) 3256 << ConvTy->isEnumeralType() << ConvTy; 3257 } 3258 return move(FromE); 3259 } 3260 3261 if (!From->getType()->isIntegralOrEnumerationType()) 3262 Diag(Loc, NotIntDiag) 3263 << From->getType() << From->getSourceRange(); 3264 3265 return move(FromE); 3266} 3267 3268/// AddOverloadCandidate - Adds the given function to the set of 3269/// candidate functions, using the given function call arguments. If 3270/// @p SuppressUserConversions, then don't allow user-defined 3271/// conversions via constructors or conversion operators. 3272/// 3273/// \para PartialOverloading true if we are performing "partial" overloading 3274/// based on an incomplete set of function arguments. This feature is used by 3275/// code completion. 3276void 3277Sema::AddOverloadCandidate(FunctionDecl *Function, 3278 DeclAccessPair FoundDecl, 3279 Expr **Args, unsigned NumArgs, 3280 OverloadCandidateSet& CandidateSet, 3281 bool SuppressUserConversions, 3282 bool PartialOverloading) { 3283 const FunctionProtoType* Proto 3284 = dyn_cast<FunctionProtoType>(Function->getType()->getAs<FunctionType>()); 3285 assert(Proto && "Functions without a prototype cannot be overloaded"); 3286 assert(!Function->getDescribedFunctionTemplate() && 3287 "Use AddTemplateOverloadCandidate for function templates"); 3288 3289 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Function)) { 3290 if (!isa<CXXConstructorDecl>(Method)) { 3291 // If we get here, it's because we're calling a member function 3292 // that is named without a member access expression (e.g., 3293 // "this->f") that was either written explicitly or created 3294 // implicitly. This can happen with a qualified call to a member 3295 // function, e.g., X::f(). We use an empty type for the implied 3296 // object argument (C++ [over.call.func]p3), and the acting context 3297 // is irrelevant. 3298 AddMethodCandidate(Method, FoundDecl, Method->getParent(), 3299 QualType(), Args, NumArgs, CandidateSet, 3300 SuppressUserConversions); 3301 return; 3302 } 3303 // We treat a constructor like a non-member function, since its object 3304 // argument doesn't participate in overload resolution. 3305 } 3306 3307 if (!CandidateSet.isNewCandidate(Function)) 3308 return; 3309 3310 // Overload resolution is always an unevaluated context. 3311 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 3312 3313 if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(Function)){ 3314 // C++ [class.copy]p3: 3315 // A member function template is never instantiated to perform the copy 3316 // of a class object to an object of its class type. 3317 QualType ClassType = Context.getTypeDeclType(Constructor->getParent()); 3318 if (NumArgs == 1 && 3319 Constructor->isCopyConstructorLikeSpecialization() && 3320 (Context.hasSameUnqualifiedType(ClassType, Args[0]->getType()) || 3321 IsDerivedFrom(Args[0]->getType(), ClassType))) 3322 return; 3323 } 3324 3325 // Add this candidate 3326 CandidateSet.push_back(OverloadCandidate()); 3327 OverloadCandidate& Candidate = CandidateSet.back(); 3328 Candidate.FoundDecl = FoundDecl; 3329 Candidate.Function = Function; 3330 Candidate.Viable = true; 3331 Candidate.IsSurrogate = false; 3332 Candidate.IgnoreObjectArgument = false; 3333 3334 unsigned NumArgsInProto = Proto->getNumArgs(); 3335 3336 // (C++ 13.3.2p2): A candidate function having fewer than m 3337 // parameters is viable only if it has an ellipsis in its parameter 3338 // list (8.3.5). 3339 if ((NumArgs + (PartialOverloading && NumArgs)) > NumArgsInProto && 3340 !Proto->isVariadic()) { 3341 Candidate.Viable = false; 3342 Candidate.FailureKind = ovl_fail_too_many_arguments; 3343 return; 3344 } 3345 3346 // (C++ 13.3.2p2): A candidate function having more than m parameters 3347 // is viable only if the (m+1)st parameter has a default argument 3348 // (8.3.6). For the purposes of overload resolution, the 3349 // parameter list is truncated on the right, so that there are 3350 // exactly m parameters. 3351 unsigned MinRequiredArgs = Function->getMinRequiredArguments(); 3352 if (NumArgs < MinRequiredArgs && !PartialOverloading) { 3353 // Not enough arguments. 3354 Candidate.Viable = false; 3355 Candidate.FailureKind = ovl_fail_too_few_arguments; 3356 return; 3357 } 3358 3359 // Determine the implicit conversion sequences for each of the 3360 // arguments. 3361 Candidate.Conversions.resize(NumArgs); 3362 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 3363 if (ArgIdx < NumArgsInProto) { 3364 // (C++ 13.3.2p3): for F to be a viable function, there shall 3365 // exist for each argument an implicit conversion sequence 3366 // (13.3.3.1) that converts that argument to the corresponding 3367 // parameter of F. 3368 QualType ParamType = Proto->getArgType(ArgIdx); 3369 Candidate.Conversions[ArgIdx] 3370 = TryCopyInitialization(*this, Args[ArgIdx], ParamType, 3371 SuppressUserConversions, 3372 /*InOverloadResolution=*/true); 3373 if (Candidate.Conversions[ArgIdx].isBad()) { 3374 Candidate.Viable = false; 3375 Candidate.FailureKind = ovl_fail_bad_conversion; 3376 break; 3377 } 3378 } else { 3379 // (C++ 13.3.2p2): For the purposes of overload resolution, any 3380 // argument for which there is no corresponding parameter is 3381 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 3382 Candidate.Conversions[ArgIdx].setEllipsis(); 3383 } 3384 } 3385} 3386 3387/// \brief Add all of the function declarations in the given function set to 3388/// the overload canddiate set. 3389void Sema::AddFunctionCandidates(const UnresolvedSetImpl &Fns, 3390 Expr **Args, unsigned NumArgs, 3391 OverloadCandidateSet& CandidateSet, 3392 bool SuppressUserConversions) { 3393 for (UnresolvedSetIterator F = Fns.begin(), E = Fns.end(); F != E; ++F) { 3394 NamedDecl *D = F.getDecl()->getUnderlyingDecl(); 3395 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { 3396 if (isa<CXXMethodDecl>(FD) && !cast<CXXMethodDecl>(FD)->isStatic()) 3397 AddMethodCandidate(cast<CXXMethodDecl>(FD), F.getPair(), 3398 cast<CXXMethodDecl>(FD)->getParent(), 3399 Args[0]->getType(), Args + 1, NumArgs - 1, 3400 CandidateSet, SuppressUserConversions); 3401 else 3402 AddOverloadCandidate(FD, F.getPair(), Args, NumArgs, CandidateSet, 3403 SuppressUserConversions); 3404 } else { 3405 FunctionTemplateDecl *FunTmpl = cast<FunctionTemplateDecl>(D); 3406 if (isa<CXXMethodDecl>(FunTmpl->getTemplatedDecl()) && 3407 !cast<CXXMethodDecl>(FunTmpl->getTemplatedDecl())->isStatic()) 3408 AddMethodTemplateCandidate(FunTmpl, F.getPair(), 3409 cast<CXXRecordDecl>(FunTmpl->getDeclContext()), 3410 /*FIXME: explicit args */ 0, 3411 Args[0]->getType(), Args + 1, NumArgs - 1, 3412 CandidateSet, 3413 SuppressUserConversions); 3414 else 3415 AddTemplateOverloadCandidate(FunTmpl, F.getPair(), 3416 /*FIXME: explicit args */ 0, 3417 Args, NumArgs, CandidateSet, 3418 SuppressUserConversions); 3419 } 3420 } 3421} 3422 3423/// AddMethodCandidate - Adds a named decl (which is some kind of 3424/// method) as a method candidate to the given overload set. 3425void Sema::AddMethodCandidate(DeclAccessPair FoundDecl, 3426 QualType ObjectType, 3427 Expr **Args, unsigned NumArgs, 3428 OverloadCandidateSet& CandidateSet, 3429 bool SuppressUserConversions) { 3430 NamedDecl *Decl = FoundDecl.getDecl(); 3431 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(Decl->getDeclContext()); 3432 3433 if (isa<UsingShadowDecl>(Decl)) 3434 Decl = cast<UsingShadowDecl>(Decl)->getTargetDecl(); 3435 3436 if (FunctionTemplateDecl *TD = dyn_cast<FunctionTemplateDecl>(Decl)) { 3437 assert(isa<CXXMethodDecl>(TD->getTemplatedDecl()) && 3438 "Expected a member function template"); 3439 AddMethodTemplateCandidate(TD, FoundDecl, ActingContext, 3440 /*ExplicitArgs*/ 0, 3441 ObjectType, Args, NumArgs, 3442 CandidateSet, 3443 SuppressUserConversions); 3444 } else { 3445 AddMethodCandidate(cast<CXXMethodDecl>(Decl), FoundDecl, ActingContext, 3446 ObjectType, Args, NumArgs, 3447 CandidateSet, SuppressUserConversions); 3448 } 3449} 3450 3451/// AddMethodCandidate - Adds the given C++ member function to the set 3452/// of candidate functions, using the given function call arguments 3453/// and the object argument (@c Object). For example, in a call 3454/// @c o.f(a1,a2), @c Object will contain @c o and @c Args will contain 3455/// both @c a1 and @c a2. If @p SuppressUserConversions, then don't 3456/// allow user-defined conversions via constructors or conversion 3457/// operators. 3458void 3459Sema::AddMethodCandidate(CXXMethodDecl *Method, DeclAccessPair FoundDecl, 3460 CXXRecordDecl *ActingContext, QualType ObjectType, 3461 Expr **Args, unsigned NumArgs, 3462 OverloadCandidateSet& CandidateSet, 3463 bool SuppressUserConversions) { 3464 const FunctionProtoType* Proto 3465 = dyn_cast<FunctionProtoType>(Method->getType()->getAs<FunctionType>()); 3466 assert(Proto && "Methods without a prototype cannot be overloaded"); 3467 assert(!isa<CXXConstructorDecl>(Method) && 3468 "Use AddOverloadCandidate for constructors"); 3469 3470 if (!CandidateSet.isNewCandidate(Method)) 3471 return; 3472 3473 // Overload resolution is always an unevaluated context. 3474 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 3475 3476 // Add this candidate 3477 CandidateSet.push_back(OverloadCandidate()); 3478 OverloadCandidate& Candidate = CandidateSet.back(); 3479 Candidate.FoundDecl = FoundDecl; 3480 Candidate.Function = Method; 3481 Candidate.IsSurrogate = false; 3482 Candidate.IgnoreObjectArgument = false; 3483 3484 unsigned NumArgsInProto = Proto->getNumArgs(); 3485 3486 // (C++ 13.3.2p2): A candidate function having fewer than m 3487 // parameters is viable only if it has an ellipsis in its parameter 3488 // list (8.3.5). 3489 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 3490 Candidate.Viable = false; 3491 Candidate.FailureKind = ovl_fail_too_many_arguments; 3492 return; 3493 } 3494 3495 // (C++ 13.3.2p2): A candidate function having more than m parameters 3496 // is viable only if the (m+1)st parameter has a default argument 3497 // (8.3.6). For the purposes of overload resolution, the 3498 // parameter list is truncated on the right, so that there are 3499 // exactly m parameters. 3500 unsigned MinRequiredArgs = Method->getMinRequiredArguments(); 3501 if (NumArgs < MinRequiredArgs) { 3502 // Not enough arguments. 3503 Candidate.Viable = false; 3504 Candidate.FailureKind = ovl_fail_too_few_arguments; 3505 return; 3506 } 3507 3508 Candidate.Viable = true; 3509 Candidate.Conversions.resize(NumArgs + 1); 3510 3511 if (Method->isStatic() || ObjectType.isNull()) 3512 // The implicit object argument is ignored. 3513 Candidate.IgnoreObjectArgument = true; 3514 else { 3515 // Determine the implicit conversion sequence for the object 3516 // parameter. 3517 Candidate.Conversions[0] 3518 = TryObjectArgumentInitialization(ObjectType, Method, ActingContext); 3519 if (Candidate.Conversions[0].isBad()) { 3520 Candidate.Viable = false; 3521 Candidate.FailureKind = ovl_fail_bad_conversion; 3522 return; 3523 } 3524 } 3525 3526 // Determine the implicit conversion sequences for each of the 3527 // arguments. 3528 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 3529 if (ArgIdx < NumArgsInProto) { 3530 // (C++ 13.3.2p3): for F to be a viable function, there shall 3531 // exist for each argument an implicit conversion sequence 3532 // (13.3.3.1) that converts that argument to the corresponding 3533 // parameter of F. 3534 QualType ParamType = Proto->getArgType(ArgIdx); 3535 Candidate.Conversions[ArgIdx + 1] 3536 = TryCopyInitialization(*this, Args[ArgIdx], ParamType, 3537 SuppressUserConversions, 3538 /*InOverloadResolution=*/true); 3539 if (Candidate.Conversions[ArgIdx + 1].isBad()) { 3540 Candidate.Viable = false; 3541 Candidate.FailureKind = ovl_fail_bad_conversion; 3542 break; 3543 } 3544 } else { 3545 // (C++ 13.3.2p2): For the purposes of overload resolution, any 3546 // argument for which there is no corresponding parameter is 3547 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 3548 Candidate.Conversions[ArgIdx + 1].setEllipsis(); 3549 } 3550 } 3551} 3552 3553/// \brief Add a C++ member function template as a candidate to the candidate 3554/// set, using template argument deduction to produce an appropriate member 3555/// function template specialization. 3556void 3557Sema::AddMethodTemplateCandidate(FunctionTemplateDecl *MethodTmpl, 3558 DeclAccessPair FoundDecl, 3559 CXXRecordDecl *ActingContext, 3560 const TemplateArgumentListInfo *ExplicitTemplateArgs, 3561 QualType ObjectType, 3562 Expr **Args, unsigned NumArgs, 3563 OverloadCandidateSet& CandidateSet, 3564 bool SuppressUserConversions) { 3565 if (!CandidateSet.isNewCandidate(MethodTmpl)) 3566 return; 3567 3568 // C++ [over.match.funcs]p7: 3569 // In each case where a candidate is a function template, candidate 3570 // function template specializations are generated using template argument 3571 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 3572 // candidate functions in the usual way.113) A given name can refer to one 3573 // or more function templates and also to a set of overloaded non-template 3574 // functions. In such a case, the candidate functions generated from each 3575 // function template are combined with the set of non-template candidate 3576 // functions. 3577 TemplateDeductionInfo Info(Context, CandidateSet.getLocation()); 3578 FunctionDecl *Specialization = 0; 3579 if (TemplateDeductionResult Result 3580 = DeduceTemplateArguments(MethodTmpl, ExplicitTemplateArgs, 3581 Args, NumArgs, Specialization, Info)) { 3582 CandidateSet.push_back(OverloadCandidate()); 3583 OverloadCandidate &Candidate = CandidateSet.back(); 3584 Candidate.FoundDecl = FoundDecl; 3585 Candidate.Function = MethodTmpl->getTemplatedDecl(); 3586 Candidate.Viable = false; 3587 Candidate.FailureKind = ovl_fail_bad_deduction; 3588 Candidate.IsSurrogate = false; 3589 Candidate.IgnoreObjectArgument = false; 3590 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result, 3591 Info); 3592 return; 3593 } 3594 3595 // Add the function template specialization produced by template argument 3596 // deduction as a candidate. 3597 assert(Specialization && "Missing member function template specialization?"); 3598 assert(isa<CXXMethodDecl>(Specialization) && 3599 "Specialization is not a member function?"); 3600 AddMethodCandidate(cast<CXXMethodDecl>(Specialization), FoundDecl, 3601 ActingContext, ObjectType, Args, NumArgs, 3602 CandidateSet, SuppressUserConversions); 3603} 3604 3605/// \brief Add a C++ function template specialization as a candidate 3606/// in the candidate set, using template argument deduction to produce 3607/// an appropriate function template specialization. 3608void 3609Sema::AddTemplateOverloadCandidate(FunctionTemplateDecl *FunctionTemplate, 3610 DeclAccessPair FoundDecl, 3611 const TemplateArgumentListInfo *ExplicitTemplateArgs, 3612 Expr **Args, unsigned NumArgs, 3613 OverloadCandidateSet& CandidateSet, 3614 bool SuppressUserConversions) { 3615 if (!CandidateSet.isNewCandidate(FunctionTemplate)) 3616 return; 3617 3618 // C++ [over.match.funcs]p7: 3619 // In each case where a candidate is a function template, candidate 3620 // function template specializations are generated using template argument 3621 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 3622 // candidate functions in the usual way.113) A given name can refer to one 3623 // or more function templates and also to a set of overloaded non-template 3624 // functions. In such a case, the candidate functions generated from each 3625 // function template are combined with the set of non-template candidate 3626 // functions. 3627 TemplateDeductionInfo Info(Context, CandidateSet.getLocation()); 3628 FunctionDecl *Specialization = 0; 3629 if (TemplateDeductionResult Result 3630 = DeduceTemplateArguments(FunctionTemplate, ExplicitTemplateArgs, 3631 Args, NumArgs, Specialization, Info)) { 3632 CandidateSet.push_back(OverloadCandidate()); 3633 OverloadCandidate &Candidate = CandidateSet.back(); 3634 Candidate.FoundDecl = FoundDecl; 3635 Candidate.Function = FunctionTemplate->getTemplatedDecl(); 3636 Candidate.Viable = false; 3637 Candidate.FailureKind = ovl_fail_bad_deduction; 3638 Candidate.IsSurrogate = false; 3639 Candidate.IgnoreObjectArgument = false; 3640 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result, 3641 Info); 3642 return; 3643 } 3644 3645 // Add the function template specialization produced by template argument 3646 // deduction as a candidate. 3647 assert(Specialization && "Missing function template specialization?"); 3648 AddOverloadCandidate(Specialization, FoundDecl, Args, NumArgs, CandidateSet, 3649 SuppressUserConversions); 3650} 3651 3652/// AddConversionCandidate - Add a C++ conversion function as a 3653/// candidate in the candidate set (C++ [over.match.conv], 3654/// C++ [over.match.copy]). From is the expression we're converting from, 3655/// and ToType is the type that we're eventually trying to convert to 3656/// (which may or may not be the same type as the type that the 3657/// conversion function produces). 3658void 3659Sema::AddConversionCandidate(CXXConversionDecl *Conversion, 3660 DeclAccessPair FoundDecl, 3661 CXXRecordDecl *ActingContext, 3662 Expr *From, QualType ToType, 3663 OverloadCandidateSet& CandidateSet) { 3664 assert(!Conversion->getDescribedFunctionTemplate() && 3665 "Conversion function templates use AddTemplateConversionCandidate"); 3666 QualType ConvType = Conversion->getConversionType().getNonReferenceType(); 3667 if (!CandidateSet.isNewCandidate(Conversion)) 3668 return; 3669 3670 // Overload resolution is always an unevaluated context. 3671 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 3672 3673 // Add this candidate 3674 CandidateSet.push_back(OverloadCandidate()); 3675 OverloadCandidate& Candidate = CandidateSet.back(); 3676 Candidate.FoundDecl = FoundDecl; 3677 Candidate.Function = Conversion; 3678 Candidate.IsSurrogate = false; 3679 Candidate.IgnoreObjectArgument = false; 3680 Candidate.FinalConversion.setAsIdentityConversion(); 3681 Candidate.FinalConversion.setFromType(ConvType); 3682 Candidate.FinalConversion.setAllToTypes(ToType); 3683 3684 // Determine the implicit conversion sequence for the implicit 3685 // object parameter. 3686 Candidate.Viable = true; 3687 Candidate.Conversions.resize(1); 3688 Candidate.Conversions[0] 3689 = TryObjectArgumentInitialization(From->getType(), Conversion, 3690 ActingContext); 3691 // Conversion functions to a different type in the base class is visible in 3692 // the derived class. So, a derived to base conversion should not participate 3693 // in overload resolution. 3694 if (Candidate.Conversions[0].Standard.Second == ICK_Derived_To_Base) 3695 Candidate.Conversions[0].Standard.Second = ICK_Identity; 3696 if (Candidate.Conversions[0].isBad()) { 3697 Candidate.Viable = false; 3698 Candidate.FailureKind = ovl_fail_bad_conversion; 3699 return; 3700 } 3701 3702 // We won't go through a user-define type conversion function to convert a 3703 // derived to base as such conversions are given Conversion Rank. They only 3704 // go through a copy constructor. 13.3.3.1.2-p4 [over.ics.user] 3705 QualType FromCanon 3706 = Context.getCanonicalType(From->getType().getUnqualifiedType()); 3707 QualType ToCanon = Context.getCanonicalType(ToType).getUnqualifiedType(); 3708 if (FromCanon == ToCanon || IsDerivedFrom(FromCanon, ToCanon)) { 3709 Candidate.Viable = false; 3710 Candidate.FailureKind = ovl_fail_trivial_conversion; 3711 return; 3712 } 3713 3714 // To determine what the conversion from the result of calling the 3715 // conversion function to the type we're eventually trying to 3716 // convert to (ToType), we need to synthesize a call to the 3717 // conversion function and attempt copy initialization from it. This 3718 // makes sure that we get the right semantics with respect to 3719 // lvalues/rvalues and the type. Fortunately, we can allocate this 3720 // call on the stack and we don't need its arguments to be 3721 // well-formed. 3722 DeclRefExpr ConversionRef(Conversion, Conversion->getType(), 3723 From->getLocStart()); 3724 ImplicitCastExpr ConversionFn(Context.getPointerType(Conversion->getType()), 3725 CastExpr::CK_FunctionToPointerDecay, 3726 &ConversionRef, CXXBaseSpecifierArray(), 3727 ImplicitCastExpr::RValue); 3728 3729 // Note that it is safe to allocate CallExpr on the stack here because 3730 // there are 0 arguments (i.e., nothing is allocated using ASTContext's 3731 // allocator). 3732 CallExpr Call(Context, &ConversionFn, 0, 0, 3733 Conversion->getConversionType().getNonLValueExprType(Context), 3734 From->getLocStart()); 3735 ImplicitConversionSequence ICS = 3736 TryCopyInitialization(*this, &Call, ToType, 3737 /*SuppressUserConversions=*/true, 3738 /*InOverloadResolution=*/false); 3739 3740 switch (ICS.getKind()) { 3741 case ImplicitConversionSequence::StandardConversion: 3742 Candidate.FinalConversion = ICS.Standard; 3743 3744 // C++ [over.ics.user]p3: 3745 // If the user-defined conversion is specified by a specialization of a 3746 // conversion function template, the second standard conversion sequence 3747 // shall have exact match rank. 3748 if (Conversion->getPrimaryTemplate() && 3749 GetConversionRank(ICS.Standard.Second) != ICR_Exact_Match) { 3750 Candidate.Viable = false; 3751 Candidate.FailureKind = ovl_fail_final_conversion_not_exact; 3752 } 3753 3754 break; 3755 3756 case ImplicitConversionSequence::BadConversion: 3757 Candidate.Viable = false; 3758 Candidate.FailureKind = ovl_fail_bad_final_conversion; 3759 break; 3760 3761 default: 3762 assert(false && 3763 "Can only end up with a standard conversion sequence or failure"); 3764 } 3765} 3766 3767/// \brief Adds a conversion function template specialization 3768/// candidate to the overload set, using template argument deduction 3769/// to deduce the template arguments of the conversion function 3770/// template from the type that we are converting to (C++ 3771/// [temp.deduct.conv]). 3772void 3773Sema::AddTemplateConversionCandidate(FunctionTemplateDecl *FunctionTemplate, 3774 DeclAccessPair FoundDecl, 3775 CXXRecordDecl *ActingDC, 3776 Expr *From, QualType ToType, 3777 OverloadCandidateSet &CandidateSet) { 3778 assert(isa<CXXConversionDecl>(FunctionTemplate->getTemplatedDecl()) && 3779 "Only conversion function templates permitted here"); 3780 3781 if (!CandidateSet.isNewCandidate(FunctionTemplate)) 3782 return; 3783 3784 TemplateDeductionInfo Info(Context, CandidateSet.getLocation()); 3785 CXXConversionDecl *Specialization = 0; 3786 if (TemplateDeductionResult Result 3787 = DeduceTemplateArguments(FunctionTemplate, ToType, 3788 Specialization, Info)) { 3789 CandidateSet.push_back(OverloadCandidate()); 3790 OverloadCandidate &Candidate = CandidateSet.back(); 3791 Candidate.FoundDecl = FoundDecl; 3792 Candidate.Function = FunctionTemplate->getTemplatedDecl(); 3793 Candidate.Viable = false; 3794 Candidate.FailureKind = ovl_fail_bad_deduction; 3795 Candidate.IsSurrogate = false; 3796 Candidate.IgnoreObjectArgument = false; 3797 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result, 3798 Info); 3799 return; 3800 } 3801 3802 // Add the conversion function template specialization produced by 3803 // template argument deduction as a candidate. 3804 assert(Specialization && "Missing function template specialization?"); 3805 AddConversionCandidate(Specialization, FoundDecl, ActingDC, From, ToType, 3806 CandidateSet); 3807} 3808 3809/// AddSurrogateCandidate - Adds a "surrogate" candidate function that 3810/// converts the given @c Object to a function pointer via the 3811/// conversion function @c Conversion, and then attempts to call it 3812/// with the given arguments (C++ [over.call.object]p2-4). Proto is 3813/// the type of function that we'll eventually be calling. 3814void Sema::AddSurrogateCandidate(CXXConversionDecl *Conversion, 3815 DeclAccessPair FoundDecl, 3816 CXXRecordDecl *ActingContext, 3817 const FunctionProtoType *Proto, 3818 QualType ObjectType, 3819 Expr **Args, unsigned NumArgs, 3820 OverloadCandidateSet& CandidateSet) { 3821 if (!CandidateSet.isNewCandidate(Conversion)) 3822 return; 3823 3824 // Overload resolution is always an unevaluated context. 3825 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 3826 3827 CandidateSet.push_back(OverloadCandidate()); 3828 OverloadCandidate& Candidate = CandidateSet.back(); 3829 Candidate.FoundDecl = FoundDecl; 3830 Candidate.Function = 0; 3831 Candidate.Surrogate = Conversion; 3832 Candidate.Viable = true; 3833 Candidate.IsSurrogate = true; 3834 Candidate.IgnoreObjectArgument = false; 3835 Candidate.Conversions.resize(NumArgs + 1); 3836 3837 // Determine the implicit conversion sequence for the implicit 3838 // object parameter. 3839 ImplicitConversionSequence ObjectInit 3840 = TryObjectArgumentInitialization(ObjectType, Conversion, ActingContext); 3841 if (ObjectInit.isBad()) { 3842 Candidate.Viable = false; 3843 Candidate.FailureKind = ovl_fail_bad_conversion; 3844 Candidate.Conversions[0] = ObjectInit; 3845 return; 3846 } 3847 3848 // The first conversion is actually a user-defined conversion whose 3849 // first conversion is ObjectInit's standard conversion (which is 3850 // effectively a reference binding). Record it as such. 3851 Candidate.Conversions[0].setUserDefined(); 3852 Candidate.Conversions[0].UserDefined.Before = ObjectInit.Standard; 3853 Candidate.Conversions[0].UserDefined.EllipsisConversion = false; 3854 Candidate.Conversions[0].UserDefined.ConversionFunction = Conversion; 3855 Candidate.Conversions[0].UserDefined.After 3856 = Candidate.Conversions[0].UserDefined.Before; 3857 Candidate.Conversions[0].UserDefined.After.setAsIdentityConversion(); 3858 3859 // Find the 3860 unsigned NumArgsInProto = Proto->getNumArgs(); 3861 3862 // (C++ 13.3.2p2): A candidate function having fewer than m 3863 // parameters is viable only if it has an ellipsis in its parameter 3864 // list (8.3.5). 3865 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 3866 Candidate.Viable = false; 3867 Candidate.FailureKind = ovl_fail_too_many_arguments; 3868 return; 3869 } 3870 3871 // Function types don't have any default arguments, so just check if 3872 // we have enough arguments. 3873 if (NumArgs < NumArgsInProto) { 3874 // Not enough arguments. 3875 Candidate.Viable = false; 3876 Candidate.FailureKind = ovl_fail_too_few_arguments; 3877 return; 3878 } 3879 3880 // Determine the implicit conversion sequences for each of the 3881 // arguments. 3882 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 3883 if (ArgIdx < NumArgsInProto) { 3884 // (C++ 13.3.2p3): for F to be a viable function, there shall 3885 // exist for each argument an implicit conversion sequence 3886 // (13.3.3.1) that converts that argument to the corresponding 3887 // parameter of F. 3888 QualType ParamType = Proto->getArgType(ArgIdx); 3889 Candidate.Conversions[ArgIdx + 1] 3890 = TryCopyInitialization(*this, Args[ArgIdx], ParamType, 3891 /*SuppressUserConversions=*/false, 3892 /*InOverloadResolution=*/false); 3893 if (Candidate.Conversions[ArgIdx + 1].isBad()) { 3894 Candidate.Viable = false; 3895 Candidate.FailureKind = ovl_fail_bad_conversion; 3896 break; 3897 } 3898 } else { 3899 // (C++ 13.3.2p2): For the purposes of overload resolution, any 3900 // argument for which there is no corresponding parameter is 3901 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 3902 Candidate.Conversions[ArgIdx + 1].setEllipsis(); 3903 } 3904 } 3905} 3906 3907/// \brief Add overload candidates for overloaded operators that are 3908/// member functions. 3909/// 3910/// Add the overloaded operator candidates that are member functions 3911/// for the operator Op that was used in an operator expression such 3912/// as "x Op y". , Args/NumArgs provides the operator arguments, and 3913/// CandidateSet will store the added overload candidates. (C++ 3914/// [over.match.oper]). 3915void Sema::AddMemberOperatorCandidates(OverloadedOperatorKind Op, 3916 SourceLocation OpLoc, 3917 Expr **Args, unsigned NumArgs, 3918 OverloadCandidateSet& CandidateSet, 3919 SourceRange OpRange) { 3920 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 3921 3922 // C++ [over.match.oper]p3: 3923 // For a unary operator @ with an operand of a type whose 3924 // cv-unqualified version is T1, and for a binary operator @ with 3925 // a left operand of a type whose cv-unqualified version is T1 and 3926 // a right operand of a type whose cv-unqualified version is T2, 3927 // three sets of candidate functions, designated member 3928 // candidates, non-member candidates and built-in candidates, are 3929 // constructed as follows: 3930 QualType T1 = Args[0]->getType(); 3931 QualType T2; 3932 if (NumArgs > 1) 3933 T2 = Args[1]->getType(); 3934 3935 // -- If T1 is a class type, the set of member candidates is the 3936 // result of the qualified lookup of T1::operator@ 3937 // (13.3.1.1.1); otherwise, the set of member candidates is 3938 // empty. 3939 if (const RecordType *T1Rec = T1->getAs<RecordType>()) { 3940 // Complete the type if it can be completed. Otherwise, we're done. 3941 if (RequireCompleteType(OpLoc, T1, PDiag())) 3942 return; 3943 3944 LookupResult Operators(*this, OpName, OpLoc, LookupOrdinaryName); 3945 LookupQualifiedName(Operators, T1Rec->getDecl()); 3946 Operators.suppressDiagnostics(); 3947 3948 for (LookupResult::iterator Oper = Operators.begin(), 3949 OperEnd = Operators.end(); 3950 Oper != OperEnd; 3951 ++Oper) 3952 AddMethodCandidate(Oper.getPair(), Args[0]->getType(), 3953 Args + 1, NumArgs - 1, CandidateSet, 3954 /* SuppressUserConversions = */ false); 3955 } 3956} 3957 3958/// AddBuiltinCandidate - Add a candidate for a built-in 3959/// operator. ResultTy and ParamTys are the result and parameter types 3960/// of the built-in candidate, respectively. Args and NumArgs are the 3961/// arguments being passed to the candidate. IsAssignmentOperator 3962/// should be true when this built-in candidate is an assignment 3963/// operator. NumContextualBoolArguments is the number of arguments 3964/// (at the beginning of the argument list) that will be contextually 3965/// converted to bool. 3966void Sema::AddBuiltinCandidate(QualType ResultTy, QualType *ParamTys, 3967 Expr **Args, unsigned NumArgs, 3968 OverloadCandidateSet& CandidateSet, 3969 bool IsAssignmentOperator, 3970 unsigned NumContextualBoolArguments) { 3971 // Overload resolution is always an unevaluated context. 3972 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 3973 3974 // Add this candidate 3975 CandidateSet.push_back(OverloadCandidate()); 3976 OverloadCandidate& Candidate = CandidateSet.back(); 3977 Candidate.FoundDecl = DeclAccessPair::make(0, AS_none); 3978 Candidate.Function = 0; 3979 Candidate.IsSurrogate = false; 3980 Candidate.IgnoreObjectArgument = false; 3981 Candidate.BuiltinTypes.ResultTy = ResultTy; 3982 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 3983 Candidate.BuiltinTypes.ParamTypes[ArgIdx] = ParamTys[ArgIdx]; 3984 3985 // Determine the implicit conversion sequences for each of the 3986 // arguments. 3987 Candidate.Viable = true; 3988 Candidate.Conversions.resize(NumArgs); 3989 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 3990 // C++ [over.match.oper]p4: 3991 // For the built-in assignment operators, conversions of the 3992 // left operand are restricted as follows: 3993 // -- no temporaries are introduced to hold the left operand, and 3994 // -- no user-defined conversions are applied to the left 3995 // operand to achieve a type match with the left-most 3996 // parameter of a built-in candidate. 3997 // 3998 // We block these conversions by turning off user-defined 3999 // conversions, since that is the only way that initialization of 4000 // a reference to a non-class type can occur from something that 4001 // is not of the same type. 4002 if (ArgIdx < NumContextualBoolArguments) { 4003 assert(ParamTys[ArgIdx] == Context.BoolTy && 4004 "Contextual conversion to bool requires bool type"); 4005 Candidate.Conversions[ArgIdx] = TryContextuallyConvertToBool(Args[ArgIdx]); 4006 } else { 4007 Candidate.Conversions[ArgIdx] 4008 = TryCopyInitialization(*this, Args[ArgIdx], ParamTys[ArgIdx], 4009 ArgIdx == 0 && IsAssignmentOperator, 4010 /*InOverloadResolution=*/false); 4011 } 4012 if (Candidate.Conversions[ArgIdx].isBad()) { 4013 Candidate.Viable = false; 4014 Candidate.FailureKind = ovl_fail_bad_conversion; 4015 break; 4016 } 4017 } 4018} 4019 4020/// BuiltinCandidateTypeSet - A set of types that will be used for the 4021/// candidate operator functions for built-in operators (C++ 4022/// [over.built]). The types are separated into pointer types and 4023/// enumeration types. 4024class BuiltinCandidateTypeSet { 4025 /// TypeSet - A set of types. 4026 typedef llvm::SmallPtrSet<QualType, 8> TypeSet; 4027 4028 /// PointerTypes - The set of pointer types that will be used in the 4029 /// built-in candidates. 4030 TypeSet PointerTypes; 4031 4032 /// MemberPointerTypes - The set of member pointer types that will be 4033 /// used in the built-in candidates. 4034 TypeSet MemberPointerTypes; 4035 4036 /// EnumerationTypes - The set of enumeration types that will be 4037 /// used in the built-in candidates. 4038 TypeSet EnumerationTypes; 4039 4040 /// \brief The set of vector types that will be used in the built-in 4041 /// candidates. 4042 TypeSet VectorTypes; 4043 4044 /// Sema - The semantic analysis instance where we are building the 4045 /// candidate type set. 4046 Sema &SemaRef; 4047 4048 /// Context - The AST context in which we will build the type sets. 4049 ASTContext &Context; 4050 4051 bool AddPointerWithMoreQualifiedTypeVariants(QualType Ty, 4052 const Qualifiers &VisibleQuals); 4053 bool AddMemberPointerWithMoreQualifiedTypeVariants(QualType Ty); 4054 4055public: 4056 /// iterator - Iterates through the types that are part of the set. 4057 typedef TypeSet::iterator iterator; 4058 4059 BuiltinCandidateTypeSet(Sema &SemaRef) 4060 : SemaRef(SemaRef), Context(SemaRef.Context) { } 4061 4062 void AddTypesConvertedFrom(QualType Ty, 4063 SourceLocation Loc, 4064 bool AllowUserConversions, 4065 bool AllowExplicitConversions, 4066 const Qualifiers &VisibleTypeConversionsQuals); 4067 4068 /// pointer_begin - First pointer type found; 4069 iterator pointer_begin() { return PointerTypes.begin(); } 4070 4071 /// pointer_end - Past the last pointer type found; 4072 iterator pointer_end() { return PointerTypes.end(); } 4073 4074 /// member_pointer_begin - First member pointer type found; 4075 iterator member_pointer_begin() { return MemberPointerTypes.begin(); } 4076 4077 /// member_pointer_end - Past the last member pointer type found; 4078 iterator member_pointer_end() { return MemberPointerTypes.end(); } 4079 4080 /// enumeration_begin - First enumeration type found; 4081 iterator enumeration_begin() { return EnumerationTypes.begin(); } 4082 4083 /// enumeration_end - Past the last enumeration type found; 4084 iterator enumeration_end() { return EnumerationTypes.end(); } 4085 4086 iterator vector_begin() { return VectorTypes.begin(); } 4087 iterator vector_end() { return VectorTypes.end(); } 4088}; 4089 4090/// AddPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty to 4091/// the set of pointer types along with any more-qualified variants of 4092/// that type. For example, if @p Ty is "int const *", this routine 4093/// will add "int const *", "int const volatile *", "int const 4094/// restrict *", and "int const volatile restrict *" to the set of 4095/// pointer types. Returns true if the add of @p Ty itself succeeded, 4096/// false otherwise. 4097/// 4098/// FIXME: what to do about extended qualifiers? 4099bool 4100BuiltinCandidateTypeSet::AddPointerWithMoreQualifiedTypeVariants(QualType Ty, 4101 const Qualifiers &VisibleQuals) { 4102 4103 // Insert this type. 4104 if (!PointerTypes.insert(Ty)) 4105 return false; 4106 4107 const PointerType *PointerTy = Ty->getAs<PointerType>(); 4108 assert(PointerTy && "type was not a pointer type!"); 4109 4110 QualType PointeeTy = PointerTy->getPointeeType(); 4111 // Don't add qualified variants of arrays. For one, they're not allowed 4112 // (the qualifier would sink to the element type), and for another, the 4113 // only overload situation where it matters is subscript or pointer +- int, 4114 // and those shouldn't have qualifier variants anyway. 4115 if (PointeeTy->isArrayType()) 4116 return true; 4117 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 4118 if (const ConstantArrayType *Array =Context.getAsConstantArrayType(PointeeTy)) 4119 BaseCVR = Array->getElementType().getCVRQualifiers(); 4120 bool hasVolatile = VisibleQuals.hasVolatile(); 4121 bool hasRestrict = VisibleQuals.hasRestrict(); 4122 4123 // Iterate through all strict supersets of BaseCVR. 4124 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 4125 if ((CVR | BaseCVR) != CVR) continue; 4126 // Skip over Volatile/Restrict if no Volatile/Restrict found anywhere 4127 // in the types. 4128 if ((CVR & Qualifiers::Volatile) && !hasVolatile) continue; 4129 if ((CVR & Qualifiers::Restrict) && !hasRestrict) continue; 4130 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 4131 PointerTypes.insert(Context.getPointerType(QPointeeTy)); 4132 } 4133 4134 return true; 4135} 4136 4137/// AddMemberPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty 4138/// to the set of pointer types along with any more-qualified variants of 4139/// that type. For example, if @p Ty is "int const *", this routine 4140/// will add "int const *", "int const volatile *", "int const 4141/// restrict *", and "int const volatile restrict *" to the set of 4142/// pointer types. Returns true if the add of @p Ty itself succeeded, 4143/// false otherwise. 4144/// 4145/// FIXME: what to do about extended qualifiers? 4146bool 4147BuiltinCandidateTypeSet::AddMemberPointerWithMoreQualifiedTypeVariants( 4148 QualType Ty) { 4149 // Insert this type. 4150 if (!MemberPointerTypes.insert(Ty)) 4151 return false; 4152 4153 const MemberPointerType *PointerTy = Ty->getAs<MemberPointerType>(); 4154 assert(PointerTy && "type was not a member pointer type!"); 4155 4156 QualType PointeeTy = PointerTy->getPointeeType(); 4157 // Don't add qualified variants of arrays. For one, they're not allowed 4158 // (the qualifier would sink to the element type), and for another, the 4159 // only overload situation where it matters is subscript or pointer +- int, 4160 // and those shouldn't have qualifier variants anyway. 4161 if (PointeeTy->isArrayType()) 4162 return true; 4163 const Type *ClassTy = PointerTy->getClass(); 4164 4165 // Iterate through all strict supersets of the pointee type's CVR 4166 // qualifiers. 4167 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 4168 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 4169 if ((CVR | BaseCVR) != CVR) continue; 4170 4171 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 4172 MemberPointerTypes.insert(Context.getMemberPointerType(QPointeeTy, ClassTy)); 4173 } 4174 4175 return true; 4176} 4177 4178/// AddTypesConvertedFrom - Add each of the types to which the type @p 4179/// Ty can be implicit converted to the given set of @p Types. We're 4180/// primarily interested in pointer types and enumeration types. We also 4181/// take member pointer types, for the conditional operator. 4182/// AllowUserConversions is true if we should look at the conversion 4183/// functions of a class type, and AllowExplicitConversions if we 4184/// should also include the explicit conversion functions of a class 4185/// type. 4186void 4187BuiltinCandidateTypeSet::AddTypesConvertedFrom(QualType Ty, 4188 SourceLocation Loc, 4189 bool AllowUserConversions, 4190 bool AllowExplicitConversions, 4191 const Qualifiers &VisibleQuals) { 4192 // Only deal with canonical types. 4193 Ty = Context.getCanonicalType(Ty); 4194 4195 // Look through reference types; they aren't part of the type of an 4196 // expression for the purposes of conversions. 4197 if (const ReferenceType *RefTy = Ty->getAs<ReferenceType>()) 4198 Ty = RefTy->getPointeeType(); 4199 4200 // We don't care about qualifiers on the type. 4201 Ty = Ty.getLocalUnqualifiedType(); 4202 4203 // If we're dealing with an array type, decay to the pointer. 4204 if (Ty->isArrayType()) 4205 Ty = SemaRef.Context.getArrayDecayedType(Ty); 4206 4207 if (const PointerType *PointerTy = Ty->getAs<PointerType>()) { 4208 QualType PointeeTy = PointerTy->getPointeeType(); 4209 4210 // Insert our type, and its more-qualified variants, into the set 4211 // of types. 4212 if (!AddPointerWithMoreQualifiedTypeVariants(Ty, VisibleQuals)) 4213 return; 4214 } else if (Ty->isMemberPointerType()) { 4215 // Member pointers are far easier, since the pointee can't be converted. 4216 if (!AddMemberPointerWithMoreQualifiedTypeVariants(Ty)) 4217 return; 4218 } else if (Ty->isEnumeralType()) { 4219 EnumerationTypes.insert(Ty); 4220 } else if (Ty->isVectorType()) { 4221 VectorTypes.insert(Ty); 4222 } else if (AllowUserConversions) { 4223 if (const RecordType *TyRec = Ty->getAs<RecordType>()) { 4224 if (SemaRef.RequireCompleteType(Loc, Ty, 0)) { 4225 // No conversion functions in incomplete types. 4226 return; 4227 } 4228 4229 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 4230 const UnresolvedSetImpl *Conversions 4231 = ClassDecl->getVisibleConversionFunctions(); 4232 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 4233 E = Conversions->end(); I != E; ++I) { 4234 NamedDecl *D = I.getDecl(); 4235 if (isa<UsingShadowDecl>(D)) 4236 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 4237 4238 // Skip conversion function templates; they don't tell us anything 4239 // about which builtin types we can convert to. 4240 if (isa<FunctionTemplateDecl>(D)) 4241 continue; 4242 4243 CXXConversionDecl *Conv = cast<CXXConversionDecl>(D); 4244 if (AllowExplicitConversions || !Conv->isExplicit()) { 4245 AddTypesConvertedFrom(Conv->getConversionType(), Loc, false, false, 4246 VisibleQuals); 4247 } 4248 } 4249 } 4250 } 4251} 4252 4253/// \brief Helper function for AddBuiltinOperatorCandidates() that adds 4254/// the volatile- and non-volatile-qualified assignment operators for the 4255/// given type to the candidate set. 4256static void AddBuiltinAssignmentOperatorCandidates(Sema &S, 4257 QualType T, 4258 Expr **Args, 4259 unsigned NumArgs, 4260 OverloadCandidateSet &CandidateSet) { 4261 QualType ParamTypes[2]; 4262 4263 // T& operator=(T&, T) 4264 ParamTypes[0] = S.Context.getLValueReferenceType(T); 4265 ParamTypes[1] = T; 4266 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4267 /*IsAssignmentOperator=*/true); 4268 4269 if (!S.Context.getCanonicalType(T).isVolatileQualified()) { 4270 // volatile T& operator=(volatile T&, T) 4271 ParamTypes[0] 4272 = S.Context.getLValueReferenceType(S.Context.getVolatileType(T)); 4273 ParamTypes[1] = T; 4274 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4275 /*IsAssignmentOperator=*/true); 4276 } 4277} 4278 4279/// CollectVRQualifiers - This routine returns Volatile/Restrict qualifiers, 4280/// if any, found in visible type conversion functions found in ArgExpr's type. 4281static Qualifiers CollectVRQualifiers(ASTContext &Context, Expr* ArgExpr) { 4282 Qualifiers VRQuals; 4283 const RecordType *TyRec; 4284 if (const MemberPointerType *RHSMPType = 4285 ArgExpr->getType()->getAs<MemberPointerType>()) 4286 TyRec = RHSMPType->getClass()->getAs<RecordType>(); 4287 else 4288 TyRec = ArgExpr->getType()->getAs<RecordType>(); 4289 if (!TyRec) { 4290 // Just to be safe, assume the worst case. 4291 VRQuals.addVolatile(); 4292 VRQuals.addRestrict(); 4293 return VRQuals; 4294 } 4295 4296 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 4297 if (!ClassDecl->hasDefinition()) 4298 return VRQuals; 4299 4300 const UnresolvedSetImpl *Conversions = 4301 ClassDecl->getVisibleConversionFunctions(); 4302 4303 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 4304 E = Conversions->end(); I != E; ++I) { 4305 NamedDecl *D = I.getDecl(); 4306 if (isa<UsingShadowDecl>(D)) 4307 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 4308 if (CXXConversionDecl *Conv = dyn_cast<CXXConversionDecl>(D)) { 4309 QualType CanTy = Context.getCanonicalType(Conv->getConversionType()); 4310 if (const ReferenceType *ResTypeRef = CanTy->getAs<ReferenceType>()) 4311 CanTy = ResTypeRef->getPointeeType(); 4312 // Need to go down the pointer/mempointer chain and add qualifiers 4313 // as see them. 4314 bool done = false; 4315 while (!done) { 4316 if (const PointerType *ResTypePtr = CanTy->getAs<PointerType>()) 4317 CanTy = ResTypePtr->getPointeeType(); 4318 else if (const MemberPointerType *ResTypeMPtr = 4319 CanTy->getAs<MemberPointerType>()) 4320 CanTy = ResTypeMPtr->getPointeeType(); 4321 else 4322 done = true; 4323 if (CanTy.isVolatileQualified()) 4324 VRQuals.addVolatile(); 4325 if (CanTy.isRestrictQualified()) 4326 VRQuals.addRestrict(); 4327 if (VRQuals.hasRestrict() && VRQuals.hasVolatile()) 4328 return VRQuals; 4329 } 4330 } 4331 } 4332 return VRQuals; 4333} 4334 4335/// AddBuiltinOperatorCandidates - Add the appropriate built-in 4336/// operator overloads to the candidate set (C++ [over.built]), based 4337/// on the operator @p Op and the arguments given. For example, if the 4338/// operator is a binary '+', this routine might add "int 4339/// operator+(int, int)" to cover integer addition. 4340void 4341Sema::AddBuiltinOperatorCandidates(OverloadedOperatorKind Op, 4342 SourceLocation OpLoc, 4343 Expr **Args, unsigned NumArgs, 4344 OverloadCandidateSet& CandidateSet) { 4345 // The set of "promoted arithmetic types", which are the arithmetic 4346 // types are that preserved by promotion (C++ [over.built]p2). Note 4347 // that the first few of these types are the promoted integral 4348 // types; these types need to be first. 4349 // FIXME: What about complex? 4350 const unsigned FirstIntegralType = 0; 4351 const unsigned LastIntegralType = 13; 4352 const unsigned FirstPromotedIntegralType = 7, 4353 LastPromotedIntegralType = 13; 4354 const unsigned FirstPromotedArithmeticType = 7, 4355 LastPromotedArithmeticType = 16; 4356 const unsigned NumArithmeticTypes = 16; 4357 QualType ArithmeticTypes[NumArithmeticTypes] = { 4358 Context.BoolTy, Context.CharTy, Context.WCharTy, 4359// FIXME: Context.Char16Ty, Context.Char32Ty, 4360 Context.SignedCharTy, Context.ShortTy, 4361 Context.UnsignedCharTy, Context.UnsignedShortTy, 4362 Context.IntTy, Context.LongTy, Context.LongLongTy, 4363 Context.UnsignedIntTy, Context.UnsignedLongTy, Context.UnsignedLongLongTy, 4364 Context.FloatTy, Context.DoubleTy, Context.LongDoubleTy 4365 }; 4366 assert(ArithmeticTypes[FirstPromotedIntegralType] == Context.IntTy && 4367 "Invalid first promoted integral type"); 4368 assert(ArithmeticTypes[LastPromotedIntegralType - 1] 4369 == Context.UnsignedLongLongTy && 4370 "Invalid last promoted integral type"); 4371 assert(ArithmeticTypes[FirstPromotedArithmeticType] == Context.IntTy && 4372 "Invalid first promoted arithmetic type"); 4373 assert(ArithmeticTypes[LastPromotedArithmeticType - 1] 4374 == Context.LongDoubleTy && 4375 "Invalid last promoted arithmetic type"); 4376 4377 // Find all of the types that the arguments can convert to, but only 4378 // if the operator we're looking at has built-in operator candidates 4379 // that make use of these types. 4380 Qualifiers VisibleTypeConversionsQuals; 4381 VisibleTypeConversionsQuals.addConst(); 4382 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 4383 VisibleTypeConversionsQuals += CollectVRQualifiers(Context, Args[ArgIdx]); 4384 4385 BuiltinCandidateTypeSet CandidateTypes(*this); 4386 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 4387 CandidateTypes.AddTypesConvertedFrom(Args[ArgIdx]->getType(), 4388 OpLoc, 4389 true, 4390 (Op == OO_Exclaim || 4391 Op == OO_AmpAmp || 4392 Op == OO_PipePipe), 4393 VisibleTypeConversionsQuals); 4394 4395 bool isComparison = false; 4396 switch (Op) { 4397 case OO_None: 4398 case NUM_OVERLOADED_OPERATORS: 4399 assert(false && "Expected an overloaded operator"); 4400 break; 4401 4402 case OO_Star: // '*' is either unary or binary 4403 if (NumArgs == 1) 4404 goto UnaryStar; 4405 else 4406 goto BinaryStar; 4407 break; 4408 4409 case OO_Plus: // '+' is either unary or binary 4410 if (NumArgs == 1) 4411 goto UnaryPlus; 4412 else 4413 goto BinaryPlus; 4414 break; 4415 4416 case OO_Minus: // '-' is either unary or binary 4417 if (NumArgs == 1) 4418 goto UnaryMinus; 4419 else 4420 goto BinaryMinus; 4421 break; 4422 4423 case OO_Amp: // '&' is either unary or binary 4424 if (NumArgs == 1) 4425 goto UnaryAmp; 4426 else 4427 goto BinaryAmp; 4428 4429 case OO_PlusPlus: 4430 case OO_MinusMinus: 4431 // C++ [over.built]p3: 4432 // 4433 // For every pair (T, VQ), where T is an arithmetic type, and VQ 4434 // is either volatile or empty, there exist candidate operator 4435 // functions of the form 4436 // 4437 // VQ T& operator++(VQ T&); 4438 // T operator++(VQ T&, int); 4439 // 4440 // C++ [over.built]p4: 4441 // 4442 // For every pair (T, VQ), where T is an arithmetic type other 4443 // than bool, and VQ is either volatile or empty, there exist 4444 // candidate operator functions of the form 4445 // 4446 // VQ T& operator--(VQ T&); 4447 // T operator--(VQ T&, int); 4448 for (unsigned Arith = (Op == OO_PlusPlus? 0 : 1); 4449 Arith < NumArithmeticTypes; ++Arith) { 4450 QualType ArithTy = ArithmeticTypes[Arith]; 4451 QualType ParamTypes[2] 4452 = { Context.getLValueReferenceType(ArithTy), Context.IntTy }; 4453 4454 // Non-volatile version. 4455 if (NumArgs == 1) 4456 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 4457 else 4458 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 4459 // heuristic to reduce number of builtin candidates in the set. 4460 // Add volatile version only if there are conversions to a volatile type. 4461 if (VisibleTypeConversionsQuals.hasVolatile()) { 4462 // Volatile version 4463 ParamTypes[0] 4464 = Context.getLValueReferenceType(Context.getVolatileType(ArithTy)); 4465 if (NumArgs == 1) 4466 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 4467 else 4468 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 4469 } 4470 } 4471 4472 // C++ [over.built]p5: 4473 // 4474 // For every pair (T, VQ), where T is a cv-qualified or 4475 // cv-unqualified object type, and VQ is either volatile or 4476 // empty, there exist candidate operator functions of the form 4477 // 4478 // T*VQ& operator++(T*VQ&); 4479 // T*VQ& operator--(T*VQ&); 4480 // T* operator++(T*VQ&, int); 4481 // T* operator--(T*VQ&, int); 4482 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 4483 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4484 // Skip pointer types that aren't pointers to object types. 4485 if (!(*Ptr)->getPointeeType()->isIncompleteOrObjectType()) 4486 continue; 4487 4488 QualType ParamTypes[2] = { 4489 Context.getLValueReferenceType(*Ptr), Context.IntTy 4490 }; 4491 4492 // Without volatile 4493 if (NumArgs == 1) 4494 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 4495 else 4496 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 4497 4498 if (!Context.getCanonicalType(*Ptr).isVolatileQualified() && 4499 VisibleTypeConversionsQuals.hasVolatile()) { 4500 // With volatile 4501 ParamTypes[0] 4502 = Context.getLValueReferenceType(Context.getVolatileType(*Ptr)); 4503 if (NumArgs == 1) 4504 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 4505 else 4506 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 4507 } 4508 } 4509 break; 4510 4511 UnaryStar: 4512 // C++ [over.built]p6: 4513 // For every cv-qualified or cv-unqualified object type T, there 4514 // exist candidate operator functions of the form 4515 // 4516 // T& operator*(T*); 4517 // 4518 // C++ [over.built]p7: 4519 // For every function type T, there exist candidate operator 4520 // functions of the form 4521 // T& operator*(T*); 4522 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 4523 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4524 QualType ParamTy = *Ptr; 4525 QualType PointeeTy = ParamTy->getAs<PointerType>()->getPointeeType(); 4526 AddBuiltinCandidate(Context.getLValueReferenceType(PointeeTy), 4527 &ParamTy, Args, 1, CandidateSet); 4528 } 4529 break; 4530 4531 UnaryPlus: 4532 // C++ [over.built]p8: 4533 // For every type T, there exist candidate operator functions of 4534 // the form 4535 // 4536 // T* operator+(T*); 4537 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 4538 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4539 QualType ParamTy = *Ptr; 4540 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet); 4541 } 4542 4543 // Fall through 4544 4545 UnaryMinus: 4546 // C++ [over.built]p9: 4547 // For every promoted arithmetic type T, there exist candidate 4548 // operator functions of the form 4549 // 4550 // T operator+(T); 4551 // T operator-(T); 4552 for (unsigned Arith = FirstPromotedArithmeticType; 4553 Arith < LastPromotedArithmeticType; ++Arith) { 4554 QualType ArithTy = ArithmeticTypes[Arith]; 4555 AddBuiltinCandidate(ArithTy, &ArithTy, Args, 1, CandidateSet); 4556 } 4557 4558 // Extension: We also add these operators for vector types. 4559 for (BuiltinCandidateTypeSet::iterator Vec = CandidateTypes.vector_begin(), 4560 VecEnd = CandidateTypes.vector_end(); 4561 Vec != VecEnd; ++Vec) { 4562 QualType VecTy = *Vec; 4563 AddBuiltinCandidate(VecTy, &VecTy, Args, 1, CandidateSet); 4564 } 4565 break; 4566 4567 case OO_Tilde: 4568 // C++ [over.built]p10: 4569 // For every promoted integral type T, there exist candidate 4570 // operator functions of the form 4571 // 4572 // T operator~(T); 4573 for (unsigned Int = FirstPromotedIntegralType; 4574 Int < LastPromotedIntegralType; ++Int) { 4575 QualType IntTy = ArithmeticTypes[Int]; 4576 AddBuiltinCandidate(IntTy, &IntTy, Args, 1, CandidateSet); 4577 } 4578 4579 // Extension: We also add this operator for vector types. 4580 for (BuiltinCandidateTypeSet::iterator Vec = CandidateTypes.vector_begin(), 4581 VecEnd = CandidateTypes.vector_end(); 4582 Vec != VecEnd; ++Vec) { 4583 QualType VecTy = *Vec; 4584 AddBuiltinCandidate(VecTy, &VecTy, Args, 1, CandidateSet); 4585 } 4586 break; 4587 4588 case OO_New: 4589 case OO_Delete: 4590 case OO_Array_New: 4591 case OO_Array_Delete: 4592 case OO_Call: 4593 assert(false && "Special operators don't use AddBuiltinOperatorCandidates"); 4594 break; 4595 4596 case OO_Comma: 4597 UnaryAmp: 4598 case OO_Arrow: 4599 // C++ [over.match.oper]p3: 4600 // -- For the operator ',', the unary operator '&', or the 4601 // operator '->', the built-in candidates set is empty. 4602 break; 4603 4604 case OO_EqualEqual: 4605 case OO_ExclaimEqual: 4606 // C++ [over.match.oper]p16: 4607 // For every pointer to member type T, there exist candidate operator 4608 // functions of the form 4609 // 4610 // bool operator==(T,T); 4611 // bool operator!=(T,T); 4612 for (BuiltinCandidateTypeSet::iterator 4613 MemPtr = CandidateTypes.member_pointer_begin(), 4614 MemPtrEnd = CandidateTypes.member_pointer_end(); 4615 MemPtr != MemPtrEnd; 4616 ++MemPtr) { 4617 QualType ParamTypes[2] = { *MemPtr, *MemPtr }; 4618 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 4619 } 4620 4621 // Fall through 4622 4623 case OO_Less: 4624 case OO_Greater: 4625 case OO_LessEqual: 4626 case OO_GreaterEqual: 4627 // C++ [over.built]p15: 4628 // 4629 // For every pointer or enumeration type T, there exist 4630 // candidate operator functions of the form 4631 // 4632 // bool operator<(T, T); 4633 // bool operator>(T, T); 4634 // bool operator<=(T, T); 4635 // bool operator>=(T, T); 4636 // bool operator==(T, T); 4637 // bool operator!=(T, T); 4638 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 4639 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4640 QualType ParamTypes[2] = { *Ptr, *Ptr }; 4641 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 4642 } 4643 for (BuiltinCandidateTypeSet::iterator Enum 4644 = CandidateTypes.enumeration_begin(); 4645 Enum != CandidateTypes.enumeration_end(); ++Enum) { 4646 QualType ParamTypes[2] = { *Enum, *Enum }; 4647 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 4648 } 4649 4650 // Fall through. 4651 isComparison = true; 4652 4653 BinaryPlus: 4654 BinaryMinus: 4655 if (!isComparison) { 4656 // We didn't fall through, so we must have OO_Plus or OO_Minus. 4657 4658 // C++ [over.built]p13: 4659 // 4660 // For every cv-qualified or cv-unqualified object type T 4661 // there exist candidate operator functions of the form 4662 // 4663 // T* operator+(T*, ptrdiff_t); 4664 // T& operator[](T*, ptrdiff_t); [BELOW] 4665 // T* operator-(T*, ptrdiff_t); 4666 // T* operator+(ptrdiff_t, T*); 4667 // T& operator[](ptrdiff_t, T*); [BELOW] 4668 // 4669 // C++ [over.built]p14: 4670 // 4671 // For every T, where T is a pointer to object type, there 4672 // exist candidate operator functions of the form 4673 // 4674 // ptrdiff_t operator-(T, T); 4675 for (BuiltinCandidateTypeSet::iterator Ptr 4676 = CandidateTypes.pointer_begin(); 4677 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4678 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 4679 4680 // operator+(T*, ptrdiff_t) or operator-(T*, ptrdiff_t) 4681 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 4682 4683 if (Op == OO_Plus) { 4684 // T* operator+(ptrdiff_t, T*); 4685 ParamTypes[0] = ParamTypes[1]; 4686 ParamTypes[1] = *Ptr; 4687 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 4688 } else { 4689 // ptrdiff_t operator-(T, T); 4690 ParamTypes[1] = *Ptr; 4691 AddBuiltinCandidate(Context.getPointerDiffType(), ParamTypes, 4692 Args, 2, CandidateSet); 4693 } 4694 } 4695 } 4696 // Fall through 4697 4698 case OO_Slash: 4699 BinaryStar: 4700 Conditional: 4701 // C++ [over.built]p12: 4702 // 4703 // For every pair of promoted arithmetic types L and R, there 4704 // exist candidate operator functions of the form 4705 // 4706 // LR operator*(L, R); 4707 // LR operator/(L, R); 4708 // LR operator+(L, R); 4709 // LR operator-(L, R); 4710 // bool operator<(L, R); 4711 // bool operator>(L, R); 4712 // bool operator<=(L, R); 4713 // bool operator>=(L, R); 4714 // bool operator==(L, R); 4715 // bool operator!=(L, R); 4716 // 4717 // where LR is the result of the usual arithmetic conversions 4718 // between types L and R. 4719 // 4720 // C++ [over.built]p24: 4721 // 4722 // For every pair of promoted arithmetic types L and R, there exist 4723 // candidate operator functions of the form 4724 // 4725 // LR operator?(bool, L, R); 4726 // 4727 // where LR is the result of the usual arithmetic conversions 4728 // between types L and R. 4729 // Our candidates ignore the first parameter. 4730 for (unsigned Left = FirstPromotedArithmeticType; 4731 Left < LastPromotedArithmeticType; ++Left) { 4732 for (unsigned Right = FirstPromotedArithmeticType; 4733 Right < LastPromotedArithmeticType; ++Right) { 4734 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 4735 QualType Result 4736 = isComparison 4737 ? Context.BoolTy 4738 : Context.UsualArithmeticConversionsType(LandR[0], LandR[1]); 4739 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 4740 } 4741 } 4742 4743 // Extension: Add the binary operators ==, !=, <, <=, >=, >, *, /, and the 4744 // conditional operator for vector types. 4745 for (BuiltinCandidateTypeSet::iterator Vec1 = CandidateTypes.vector_begin(), 4746 Vec1End = CandidateTypes.vector_end(); 4747 Vec1 != Vec1End; ++Vec1) 4748 for (BuiltinCandidateTypeSet::iterator 4749 Vec2 = CandidateTypes.vector_begin(), 4750 Vec2End = CandidateTypes.vector_end(); 4751 Vec2 != Vec2End; ++Vec2) { 4752 QualType LandR[2] = { *Vec1, *Vec2 }; 4753 QualType Result; 4754 if (isComparison) 4755 Result = Context.BoolTy; 4756 else { 4757 if ((*Vec1)->isExtVectorType() || !(*Vec2)->isExtVectorType()) 4758 Result = *Vec1; 4759 else 4760 Result = *Vec2; 4761 } 4762 4763 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 4764 } 4765 4766 break; 4767 4768 case OO_Percent: 4769 BinaryAmp: 4770 case OO_Caret: 4771 case OO_Pipe: 4772 case OO_LessLess: 4773 case OO_GreaterGreater: 4774 // C++ [over.built]p17: 4775 // 4776 // For every pair of promoted integral types L and R, there 4777 // exist candidate operator functions of the form 4778 // 4779 // LR operator%(L, R); 4780 // LR operator&(L, R); 4781 // LR operator^(L, R); 4782 // LR operator|(L, R); 4783 // L operator<<(L, R); 4784 // L operator>>(L, R); 4785 // 4786 // where LR is the result of the usual arithmetic conversions 4787 // between types L and R. 4788 for (unsigned Left = FirstPromotedIntegralType; 4789 Left < LastPromotedIntegralType; ++Left) { 4790 for (unsigned Right = FirstPromotedIntegralType; 4791 Right < LastPromotedIntegralType; ++Right) { 4792 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 4793 QualType Result = (Op == OO_LessLess || Op == OO_GreaterGreater) 4794 ? LandR[0] 4795 : Context.UsualArithmeticConversionsType(LandR[0], LandR[1]); 4796 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 4797 } 4798 } 4799 break; 4800 4801 case OO_Equal: 4802 // C++ [over.built]p20: 4803 // 4804 // For every pair (T, VQ), where T is an enumeration or 4805 // pointer to member type and VQ is either volatile or 4806 // empty, there exist candidate operator functions of the form 4807 // 4808 // VQ T& operator=(VQ T&, T); 4809 for (BuiltinCandidateTypeSet::iterator 4810 Enum = CandidateTypes.enumeration_begin(), 4811 EnumEnd = CandidateTypes.enumeration_end(); 4812 Enum != EnumEnd; ++Enum) 4813 AddBuiltinAssignmentOperatorCandidates(*this, *Enum, Args, 2, 4814 CandidateSet); 4815 for (BuiltinCandidateTypeSet::iterator 4816 MemPtr = CandidateTypes.member_pointer_begin(), 4817 MemPtrEnd = CandidateTypes.member_pointer_end(); 4818 MemPtr != MemPtrEnd; ++MemPtr) 4819 AddBuiltinAssignmentOperatorCandidates(*this, *MemPtr, Args, 2, 4820 CandidateSet); 4821 4822 // Fall through. 4823 4824 case OO_PlusEqual: 4825 case OO_MinusEqual: 4826 // C++ [over.built]p19: 4827 // 4828 // For every pair (T, VQ), where T is any type and VQ is either 4829 // volatile or empty, there exist candidate operator functions 4830 // of the form 4831 // 4832 // T*VQ& operator=(T*VQ&, T*); 4833 // 4834 // C++ [over.built]p21: 4835 // 4836 // For every pair (T, VQ), where T is a cv-qualified or 4837 // cv-unqualified object type and VQ is either volatile or 4838 // empty, there exist candidate operator functions of the form 4839 // 4840 // T*VQ& operator+=(T*VQ&, ptrdiff_t); 4841 // T*VQ& operator-=(T*VQ&, ptrdiff_t); 4842 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 4843 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4844 QualType ParamTypes[2]; 4845 ParamTypes[1] = (Op == OO_Equal)? *Ptr : Context.getPointerDiffType(); 4846 4847 // non-volatile version 4848 ParamTypes[0] = Context.getLValueReferenceType(*Ptr); 4849 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4850 /*IsAssigmentOperator=*/Op == OO_Equal); 4851 4852 if (!Context.getCanonicalType(*Ptr).isVolatileQualified() && 4853 VisibleTypeConversionsQuals.hasVolatile()) { 4854 // volatile version 4855 ParamTypes[0] 4856 = Context.getLValueReferenceType(Context.getVolatileType(*Ptr)); 4857 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4858 /*IsAssigmentOperator=*/Op == OO_Equal); 4859 } 4860 } 4861 // Fall through. 4862 4863 case OO_StarEqual: 4864 case OO_SlashEqual: 4865 // C++ [over.built]p18: 4866 // 4867 // For every triple (L, VQ, R), where L is an arithmetic type, 4868 // VQ is either volatile or empty, and R is a promoted 4869 // arithmetic type, there exist candidate operator functions of 4870 // the form 4871 // 4872 // VQ L& operator=(VQ L&, R); 4873 // VQ L& operator*=(VQ L&, R); 4874 // VQ L& operator/=(VQ L&, R); 4875 // VQ L& operator+=(VQ L&, R); 4876 // VQ L& operator-=(VQ L&, R); 4877 for (unsigned Left = 0; Left < NumArithmeticTypes; ++Left) { 4878 for (unsigned Right = FirstPromotedArithmeticType; 4879 Right < LastPromotedArithmeticType; ++Right) { 4880 QualType ParamTypes[2]; 4881 ParamTypes[1] = ArithmeticTypes[Right]; 4882 4883 // Add this built-in operator as a candidate (VQ is empty). 4884 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 4885 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4886 /*IsAssigmentOperator=*/Op == OO_Equal); 4887 4888 // Add this built-in operator as a candidate (VQ is 'volatile'). 4889 if (VisibleTypeConversionsQuals.hasVolatile()) { 4890 ParamTypes[0] = Context.getVolatileType(ArithmeticTypes[Left]); 4891 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 4892 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4893 /*IsAssigmentOperator=*/Op == OO_Equal); 4894 } 4895 } 4896 } 4897 4898 // Extension: Add the binary operators =, +=, -=, *=, /= for vector types. 4899 for (BuiltinCandidateTypeSet::iterator Vec1 = CandidateTypes.vector_begin(), 4900 Vec1End = CandidateTypes.vector_end(); 4901 Vec1 != Vec1End; ++Vec1) 4902 for (BuiltinCandidateTypeSet::iterator 4903 Vec2 = CandidateTypes.vector_begin(), 4904 Vec2End = CandidateTypes.vector_end(); 4905 Vec2 != Vec2End; ++Vec2) { 4906 QualType ParamTypes[2]; 4907 ParamTypes[1] = *Vec2; 4908 // Add this built-in operator as a candidate (VQ is empty). 4909 ParamTypes[0] = Context.getLValueReferenceType(*Vec1); 4910 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4911 /*IsAssigmentOperator=*/Op == OO_Equal); 4912 4913 // Add this built-in operator as a candidate (VQ is 'volatile'). 4914 if (VisibleTypeConversionsQuals.hasVolatile()) { 4915 ParamTypes[0] = Context.getVolatileType(*Vec1); 4916 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 4917 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4918 /*IsAssigmentOperator=*/Op == OO_Equal); 4919 } 4920 } 4921 break; 4922 4923 case OO_PercentEqual: 4924 case OO_LessLessEqual: 4925 case OO_GreaterGreaterEqual: 4926 case OO_AmpEqual: 4927 case OO_CaretEqual: 4928 case OO_PipeEqual: 4929 // C++ [over.built]p22: 4930 // 4931 // For every triple (L, VQ, R), where L is an integral type, VQ 4932 // is either volatile or empty, and R is a promoted integral 4933 // type, there exist candidate operator functions of the form 4934 // 4935 // VQ L& operator%=(VQ L&, R); 4936 // VQ L& operator<<=(VQ L&, R); 4937 // VQ L& operator>>=(VQ L&, R); 4938 // VQ L& operator&=(VQ L&, R); 4939 // VQ L& operator^=(VQ L&, R); 4940 // VQ L& operator|=(VQ L&, R); 4941 for (unsigned Left = FirstIntegralType; Left < LastIntegralType; ++Left) { 4942 for (unsigned Right = FirstPromotedIntegralType; 4943 Right < LastPromotedIntegralType; ++Right) { 4944 QualType ParamTypes[2]; 4945 ParamTypes[1] = ArithmeticTypes[Right]; 4946 4947 // Add this built-in operator as a candidate (VQ is empty). 4948 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 4949 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 4950 if (VisibleTypeConversionsQuals.hasVolatile()) { 4951 // Add this built-in operator as a candidate (VQ is 'volatile'). 4952 ParamTypes[0] = ArithmeticTypes[Left]; 4953 ParamTypes[0] = Context.getVolatileType(ParamTypes[0]); 4954 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 4955 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 4956 } 4957 } 4958 } 4959 break; 4960 4961 case OO_Exclaim: { 4962 // C++ [over.operator]p23: 4963 // 4964 // There also exist candidate operator functions of the form 4965 // 4966 // bool operator!(bool); 4967 // bool operator&&(bool, bool); [BELOW] 4968 // bool operator||(bool, bool); [BELOW] 4969 QualType ParamTy = Context.BoolTy; 4970 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet, 4971 /*IsAssignmentOperator=*/false, 4972 /*NumContextualBoolArguments=*/1); 4973 break; 4974 } 4975 4976 case OO_AmpAmp: 4977 case OO_PipePipe: { 4978 // C++ [over.operator]p23: 4979 // 4980 // There also exist candidate operator functions of the form 4981 // 4982 // bool operator!(bool); [ABOVE] 4983 // bool operator&&(bool, bool); 4984 // bool operator||(bool, bool); 4985 QualType ParamTypes[2] = { Context.BoolTy, Context.BoolTy }; 4986 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet, 4987 /*IsAssignmentOperator=*/false, 4988 /*NumContextualBoolArguments=*/2); 4989 break; 4990 } 4991 4992 case OO_Subscript: 4993 // C++ [over.built]p13: 4994 // 4995 // For every cv-qualified or cv-unqualified object type T there 4996 // exist candidate operator functions of the form 4997 // 4998 // T* operator+(T*, ptrdiff_t); [ABOVE] 4999 // T& operator[](T*, ptrdiff_t); 5000 // T* operator-(T*, ptrdiff_t); [ABOVE] 5001 // T* operator+(ptrdiff_t, T*); [ABOVE] 5002 // T& operator[](ptrdiff_t, T*); 5003 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 5004 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 5005 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 5006 QualType PointeeType = (*Ptr)->getAs<PointerType>()->getPointeeType(); 5007 QualType ResultTy = Context.getLValueReferenceType(PointeeType); 5008 5009 // T& operator[](T*, ptrdiff_t) 5010 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 5011 5012 // T& operator[](ptrdiff_t, T*); 5013 ParamTypes[0] = ParamTypes[1]; 5014 ParamTypes[1] = *Ptr; 5015 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 5016 } 5017 break; 5018 5019 case OO_ArrowStar: 5020 // C++ [over.built]p11: 5021 // For every quintuple (C1, C2, T, CV1, CV2), where C2 is a class type, 5022 // C1 is the same type as C2 or is a derived class of C2, T is an object 5023 // type or a function type, and CV1 and CV2 are cv-qualifier-seqs, 5024 // there exist candidate operator functions of the form 5025 // CV12 T& operator->*(CV1 C1*, CV2 T C2::*); 5026 // where CV12 is the union of CV1 and CV2. 5027 { 5028 for (BuiltinCandidateTypeSet::iterator Ptr = 5029 CandidateTypes.pointer_begin(); 5030 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 5031 QualType C1Ty = (*Ptr); 5032 QualType C1; 5033 QualifierCollector Q1; 5034 if (const PointerType *PointerTy = C1Ty->getAs<PointerType>()) { 5035 C1 = QualType(Q1.strip(PointerTy->getPointeeType()), 0); 5036 if (!isa<RecordType>(C1)) 5037 continue; 5038 // heuristic to reduce number of builtin candidates in the set. 5039 // Add volatile/restrict version only if there are conversions to a 5040 // volatile/restrict type. 5041 if (!VisibleTypeConversionsQuals.hasVolatile() && Q1.hasVolatile()) 5042 continue; 5043 if (!VisibleTypeConversionsQuals.hasRestrict() && Q1.hasRestrict()) 5044 continue; 5045 } 5046 for (BuiltinCandidateTypeSet::iterator 5047 MemPtr = CandidateTypes.member_pointer_begin(), 5048 MemPtrEnd = CandidateTypes.member_pointer_end(); 5049 MemPtr != MemPtrEnd; ++MemPtr) { 5050 const MemberPointerType *mptr = cast<MemberPointerType>(*MemPtr); 5051 QualType C2 = QualType(mptr->getClass(), 0); 5052 C2 = C2.getUnqualifiedType(); 5053 if (C1 != C2 && !IsDerivedFrom(C1, C2)) 5054 break; 5055 QualType ParamTypes[2] = { *Ptr, *MemPtr }; 5056 // build CV12 T& 5057 QualType T = mptr->getPointeeType(); 5058 if (!VisibleTypeConversionsQuals.hasVolatile() && 5059 T.isVolatileQualified()) 5060 continue; 5061 if (!VisibleTypeConversionsQuals.hasRestrict() && 5062 T.isRestrictQualified()) 5063 continue; 5064 T = Q1.apply(T); 5065 QualType ResultTy = Context.getLValueReferenceType(T); 5066 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 5067 } 5068 } 5069 } 5070 break; 5071 5072 case OO_Conditional: 5073 // Note that we don't consider the first argument, since it has been 5074 // contextually converted to bool long ago. The candidates below are 5075 // therefore added as binary. 5076 // 5077 // C++ [over.built]p24: 5078 // For every type T, where T is a pointer or pointer-to-member type, 5079 // there exist candidate operator functions of the form 5080 // 5081 // T operator?(bool, T, T); 5082 // 5083 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(), 5084 E = CandidateTypes.pointer_end(); Ptr != E; ++Ptr) { 5085 QualType ParamTypes[2] = { *Ptr, *Ptr }; 5086 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 5087 } 5088 for (BuiltinCandidateTypeSet::iterator Ptr = 5089 CandidateTypes.member_pointer_begin(), 5090 E = CandidateTypes.member_pointer_end(); Ptr != E; ++Ptr) { 5091 QualType ParamTypes[2] = { *Ptr, *Ptr }; 5092 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 5093 } 5094 goto Conditional; 5095 } 5096} 5097 5098/// \brief Add function candidates found via argument-dependent lookup 5099/// to the set of overloading candidates. 5100/// 5101/// This routine performs argument-dependent name lookup based on the 5102/// given function name (which may also be an operator name) and adds 5103/// all of the overload candidates found by ADL to the overload 5104/// candidate set (C++ [basic.lookup.argdep]). 5105void 5106Sema::AddArgumentDependentLookupCandidates(DeclarationName Name, 5107 bool Operator, 5108 Expr **Args, unsigned NumArgs, 5109 const TemplateArgumentListInfo *ExplicitTemplateArgs, 5110 OverloadCandidateSet& CandidateSet, 5111 bool PartialOverloading) { 5112 ADLResult Fns; 5113 5114 // FIXME: This approach for uniquing ADL results (and removing 5115 // redundant candidates from the set) relies on pointer-equality, 5116 // which means we need to key off the canonical decl. However, 5117 // always going back to the canonical decl might not get us the 5118 // right set of default arguments. What default arguments are 5119 // we supposed to consider on ADL candidates, anyway? 5120 5121 // FIXME: Pass in the explicit template arguments? 5122 ArgumentDependentLookup(Name, Operator, Args, NumArgs, Fns); 5123 5124 // Erase all of the candidates we already knew about. 5125 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 5126 CandEnd = CandidateSet.end(); 5127 Cand != CandEnd; ++Cand) 5128 if (Cand->Function) { 5129 Fns.erase(Cand->Function); 5130 if (FunctionTemplateDecl *FunTmpl = Cand->Function->getPrimaryTemplate()) 5131 Fns.erase(FunTmpl); 5132 } 5133 5134 // For each of the ADL candidates we found, add it to the overload 5135 // set. 5136 for (ADLResult::iterator I = Fns.begin(), E = Fns.end(); I != E; ++I) { 5137 DeclAccessPair FoundDecl = DeclAccessPair::make(*I, AS_none); 5138 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*I)) { 5139 if (ExplicitTemplateArgs) 5140 continue; 5141 5142 AddOverloadCandidate(FD, FoundDecl, Args, NumArgs, CandidateSet, 5143 false, PartialOverloading); 5144 } else 5145 AddTemplateOverloadCandidate(cast<FunctionTemplateDecl>(*I), 5146 FoundDecl, ExplicitTemplateArgs, 5147 Args, NumArgs, CandidateSet); 5148 } 5149} 5150 5151/// isBetterOverloadCandidate - Determines whether the first overload 5152/// candidate is a better candidate than the second (C++ 13.3.3p1). 5153bool 5154Sema::isBetterOverloadCandidate(const OverloadCandidate& Cand1, 5155 const OverloadCandidate& Cand2, 5156 SourceLocation Loc) { 5157 // Define viable functions to be better candidates than non-viable 5158 // functions. 5159 if (!Cand2.Viable) 5160 return Cand1.Viable; 5161 else if (!Cand1.Viable) 5162 return false; 5163 5164 // C++ [over.match.best]p1: 5165 // 5166 // -- if F is a static member function, ICS1(F) is defined such 5167 // that ICS1(F) is neither better nor worse than ICS1(G) for 5168 // any function G, and, symmetrically, ICS1(G) is neither 5169 // better nor worse than ICS1(F). 5170 unsigned StartArg = 0; 5171 if (Cand1.IgnoreObjectArgument || Cand2.IgnoreObjectArgument) 5172 StartArg = 1; 5173 5174 // C++ [over.match.best]p1: 5175 // A viable function F1 is defined to be a better function than another 5176 // viable function F2 if for all arguments i, ICSi(F1) is not a worse 5177 // conversion sequence than ICSi(F2), and then... 5178 unsigned NumArgs = Cand1.Conversions.size(); 5179 assert(Cand2.Conversions.size() == NumArgs && "Overload candidate mismatch"); 5180 bool HasBetterConversion = false; 5181 for (unsigned ArgIdx = StartArg; ArgIdx < NumArgs; ++ArgIdx) { 5182 switch (CompareImplicitConversionSequences(Cand1.Conversions[ArgIdx], 5183 Cand2.Conversions[ArgIdx])) { 5184 case ImplicitConversionSequence::Better: 5185 // Cand1 has a better conversion sequence. 5186 HasBetterConversion = true; 5187 break; 5188 5189 case ImplicitConversionSequence::Worse: 5190 // Cand1 can't be better than Cand2. 5191 return false; 5192 5193 case ImplicitConversionSequence::Indistinguishable: 5194 // Do nothing. 5195 break; 5196 } 5197 } 5198 5199 // -- for some argument j, ICSj(F1) is a better conversion sequence than 5200 // ICSj(F2), or, if not that, 5201 if (HasBetterConversion) 5202 return true; 5203 5204 // - F1 is a non-template function and F2 is a function template 5205 // specialization, or, if not that, 5206 if ((!Cand1.Function || !Cand1.Function->getPrimaryTemplate()) && 5207 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 5208 return true; 5209 5210 // -- F1 and F2 are function template specializations, and the function 5211 // template for F1 is more specialized than the template for F2 5212 // according to the partial ordering rules described in 14.5.5.2, or, 5213 // if not that, 5214 if (Cand1.Function && Cand1.Function->getPrimaryTemplate() && 5215 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 5216 if (FunctionTemplateDecl *BetterTemplate 5217 = getMoreSpecializedTemplate(Cand1.Function->getPrimaryTemplate(), 5218 Cand2.Function->getPrimaryTemplate(), 5219 Loc, 5220 isa<CXXConversionDecl>(Cand1.Function)? TPOC_Conversion 5221 : TPOC_Call)) 5222 return BetterTemplate == Cand1.Function->getPrimaryTemplate(); 5223 5224 // -- the context is an initialization by user-defined conversion 5225 // (see 8.5, 13.3.1.5) and the standard conversion sequence 5226 // from the return type of F1 to the destination type (i.e., 5227 // the type of the entity being initialized) is a better 5228 // conversion sequence than the standard conversion sequence 5229 // from the return type of F2 to the destination type. 5230 if (Cand1.Function && Cand2.Function && 5231 isa<CXXConversionDecl>(Cand1.Function) && 5232 isa<CXXConversionDecl>(Cand2.Function)) { 5233 switch (CompareStandardConversionSequences(Cand1.FinalConversion, 5234 Cand2.FinalConversion)) { 5235 case ImplicitConversionSequence::Better: 5236 // Cand1 has a better conversion sequence. 5237 return true; 5238 5239 case ImplicitConversionSequence::Worse: 5240 // Cand1 can't be better than Cand2. 5241 return false; 5242 5243 case ImplicitConversionSequence::Indistinguishable: 5244 // Do nothing 5245 break; 5246 } 5247 } 5248 5249 return false; 5250} 5251 5252/// \brief Computes the best viable function (C++ 13.3.3) 5253/// within an overload candidate set. 5254/// 5255/// \param CandidateSet the set of candidate functions. 5256/// 5257/// \param Loc the location of the function name (or operator symbol) for 5258/// which overload resolution occurs. 5259/// 5260/// \param Best f overload resolution was successful or found a deleted 5261/// function, Best points to the candidate function found. 5262/// 5263/// \returns The result of overload resolution. 5264OverloadingResult Sema::BestViableFunction(OverloadCandidateSet& CandidateSet, 5265 SourceLocation Loc, 5266 OverloadCandidateSet::iterator& Best) { 5267 // Find the best viable function. 5268 Best = CandidateSet.end(); 5269 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 5270 Cand != CandidateSet.end(); ++Cand) { 5271 if (Cand->Viable) { 5272 if (Best == CandidateSet.end() || 5273 isBetterOverloadCandidate(*Cand, *Best, Loc)) 5274 Best = Cand; 5275 } 5276 } 5277 5278 // If we didn't find any viable functions, abort. 5279 if (Best == CandidateSet.end()) 5280 return OR_No_Viable_Function; 5281 5282 // Make sure that this function is better than every other viable 5283 // function. If not, we have an ambiguity. 5284 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 5285 Cand != CandidateSet.end(); ++Cand) { 5286 if (Cand->Viable && 5287 Cand != Best && 5288 !isBetterOverloadCandidate(*Best, *Cand, Loc)) { 5289 Best = CandidateSet.end(); 5290 return OR_Ambiguous; 5291 } 5292 } 5293 5294 // Best is the best viable function. 5295 if (Best->Function && 5296 (Best->Function->isDeleted() || 5297 Best->Function->getAttr<UnavailableAttr>())) 5298 return OR_Deleted; 5299 5300 // C++ [basic.def.odr]p2: 5301 // An overloaded function is used if it is selected by overload resolution 5302 // when referred to from a potentially-evaluated expression. [Note: this 5303 // covers calls to named functions (5.2.2), operator overloading 5304 // (clause 13), user-defined conversions (12.3.2), allocation function for 5305 // placement new (5.3.4), as well as non-default initialization (8.5). 5306 if (Best->Function) 5307 MarkDeclarationReferenced(Loc, Best->Function); 5308 return OR_Success; 5309} 5310 5311namespace { 5312 5313enum OverloadCandidateKind { 5314 oc_function, 5315 oc_method, 5316 oc_constructor, 5317 oc_function_template, 5318 oc_method_template, 5319 oc_constructor_template, 5320 oc_implicit_default_constructor, 5321 oc_implicit_copy_constructor, 5322 oc_implicit_copy_assignment 5323}; 5324 5325OverloadCandidateKind ClassifyOverloadCandidate(Sema &S, 5326 FunctionDecl *Fn, 5327 std::string &Description) { 5328 bool isTemplate = false; 5329 5330 if (FunctionTemplateDecl *FunTmpl = Fn->getPrimaryTemplate()) { 5331 isTemplate = true; 5332 Description = S.getTemplateArgumentBindingsText( 5333 FunTmpl->getTemplateParameters(), *Fn->getTemplateSpecializationArgs()); 5334 } 5335 5336 if (CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(Fn)) { 5337 if (!Ctor->isImplicit()) 5338 return isTemplate ? oc_constructor_template : oc_constructor; 5339 5340 return Ctor->isCopyConstructor() ? oc_implicit_copy_constructor 5341 : oc_implicit_default_constructor; 5342 } 5343 5344 if (CXXMethodDecl *Meth = dyn_cast<CXXMethodDecl>(Fn)) { 5345 // This actually gets spelled 'candidate function' for now, but 5346 // it doesn't hurt to split it out. 5347 if (!Meth->isImplicit()) 5348 return isTemplate ? oc_method_template : oc_method; 5349 5350 assert(Meth->isCopyAssignment() 5351 && "implicit method is not copy assignment operator?"); 5352 return oc_implicit_copy_assignment; 5353 } 5354 5355 return isTemplate ? oc_function_template : oc_function; 5356} 5357 5358} // end anonymous namespace 5359 5360// Notes the location of an overload candidate. 5361void Sema::NoteOverloadCandidate(FunctionDecl *Fn) { 5362 std::string FnDesc; 5363 OverloadCandidateKind K = ClassifyOverloadCandidate(*this, Fn, FnDesc); 5364 Diag(Fn->getLocation(), diag::note_ovl_candidate) 5365 << (unsigned) K << FnDesc; 5366} 5367 5368/// Diagnoses an ambiguous conversion. The partial diagnostic is the 5369/// "lead" diagnostic; it will be given two arguments, the source and 5370/// target types of the conversion. 5371void Sema::DiagnoseAmbiguousConversion(const ImplicitConversionSequence &ICS, 5372 SourceLocation CaretLoc, 5373 const PartialDiagnostic &PDiag) { 5374 Diag(CaretLoc, PDiag) 5375 << ICS.Ambiguous.getFromType() << ICS.Ambiguous.getToType(); 5376 for (AmbiguousConversionSequence::const_iterator 5377 I = ICS.Ambiguous.begin(), E = ICS.Ambiguous.end(); I != E; ++I) { 5378 NoteOverloadCandidate(*I); 5379 } 5380} 5381 5382namespace { 5383 5384void DiagnoseBadConversion(Sema &S, OverloadCandidate *Cand, unsigned I) { 5385 const ImplicitConversionSequence &Conv = Cand->Conversions[I]; 5386 assert(Conv.isBad()); 5387 assert(Cand->Function && "for now, candidate must be a function"); 5388 FunctionDecl *Fn = Cand->Function; 5389 5390 // There's a conversion slot for the object argument if this is a 5391 // non-constructor method. Note that 'I' corresponds the 5392 // conversion-slot index. 5393 bool isObjectArgument = false; 5394 if (isa<CXXMethodDecl>(Fn) && !isa<CXXConstructorDecl>(Fn)) { 5395 if (I == 0) 5396 isObjectArgument = true; 5397 else 5398 I--; 5399 } 5400 5401 std::string FnDesc; 5402 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, FnDesc); 5403 5404 Expr *FromExpr = Conv.Bad.FromExpr; 5405 QualType FromTy = Conv.Bad.getFromType(); 5406 QualType ToTy = Conv.Bad.getToType(); 5407 5408 if (FromTy == S.Context.OverloadTy) { 5409 assert(FromExpr && "overload set argument came from implicit argument?"); 5410 Expr *E = FromExpr->IgnoreParens(); 5411 if (isa<UnaryOperator>(E)) 5412 E = cast<UnaryOperator>(E)->getSubExpr()->IgnoreParens(); 5413 DeclarationName Name = cast<OverloadExpr>(E)->getName(); 5414 5415 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_overload) 5416 << (unsigned) FnKind << FnDesc 5417 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 5418 << ToTy << Name << I+1; 5419 return; 5420 } 5421 5422 // Do some hand-waving analysis to see if the non-viability is due 5423 // to a qualifier mismatch. 5424 CanQualType CFromTy = S.Context.getCanonicalType(FromTy); 5425 CanQualType CToTy = S.Context.getCanonicalType(ToTy); 5426 if (CanQual<ReferenceType> RT = CToTy->getAs<ReferenceType>()) 5427 CToTy = RT->getPointeeType(); 5428 else { 5429 // TODO: detect and diagnose the full richness of const mismatches. 5430 if (CanQual<PointerType> FromPT = CFromTy->getAs<PointerType>()) 5431 if (CanQual<PointerType> ToPT = CToTy->getAs<PointerType>()) 5432 CFromTy = FromPT->getPointeeType(), CToTy = ToPT->getPointeeType(); 5433 } 5434 5435 if (CToTy.getUnqualifiedType() == CFromTy.getUnqualifiedType() && 5436 !CToTy.isAtLeastAsQualifiedAs(CFromTy)) { 5437 // It is dumb that we have to do this here. 5438 while (isa<ArrayType>(CFromTy)) 5439 CFromTy = CFromTy->getAs<ArrayType>()->getElementType(); 5440 while (isa<ArrayType>(CToTy)) 5441 CToTy = CFromTy->getAs<ArrayType>()->getElementType(); 5442 5443 Qualifiers FromQs = CFromTy.getQualifiers(); 5444 Qualifiers ToQs = CToTy.getQualifiers(); 5445 5446 if (FromQs.getAddressSpace() != ToQs.getAddressSpace()) { 5447 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_addrspace) 5448 << (unsigned) FnKind << FnDesc 5449 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 5450 << FromTy 5451 << FromQs.getAddressSpace() << ToQs.getAddressSpace() 5452 << (unsigned) isObjectArgument << I+1; 5453 return; 5454 } 5455 5456 unsigned CVR = FromQs.getCVRQualifiers() & ~ToQs.getCVRQualifiers(); 5457 assert(CVR && "unexpected qualifiers mismatch"); 5458 5459 if (isObjectArgument) { 5460 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr_this) 5461 << (unsigned) FnKind << FnDesc 5462 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 5463 << FromTy << (CVR - 1); 5464 } else { 5465 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr) 5466 << (unsigned) FnKind << FnDesc 5467 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 5468 << FromTy << (CVR - 1) << I+1; 5469 } 5470 return; 5471 } 5472 5473 // Diagnose references or pointers to incomplete types differently, 5474 // since it's far from impossible that the incompleteness triggered 5475 // the failure. 5476 QualType TempFromTy = FromTy.getNonReferenceType(); 5477 if (const PointerType *PTy = TempFromTy->getAs<PointerType>()) 5478 TempFromTy = PTy->getPointeeType(); 5479 if (TempFromTy->isIncompleteType()) { 5480 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_conv_incomplete) 5481 << (unsigned) FnKind << FnDesc 5482 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 5483 << FromTy << ToTy << (unsigned) isObjectArgument << I+1; 5484 return; 5485 } 5486 5487 // Diagnose base -> derived pointer conversions. 5488 unsigned BaseToDerivedConversion = 0; 5489 if (const PointerType *FromPtrTy = FromTy->getAs<PointerType>()) { 5490 if (const PointerType *ToPtrTy = ToTy->getAs<PointerType>()) { 5491 if (ToPtrTy->getPointeeType().isAtLeastAsQualifiedAs( 5492 FromPtrTy->getPointeeType()) && 5493 !FromPtrTy->getPointeeType()->isIncompleteType() && 5494 !ToPtrTy->getPointeeType()->isIncompleteType() && 5495 S.IsDerivedFrom(ToPtrTy->getPointeeType(), 5496 FromPtrTy->getPointeeType())) 5497 BaseToDerivedConversion = 1; 5498 } 5499 } else if (const ObjCObjectPointerType *FromPtrTy 5500 = FromTy->getAs<ObjCObjectPointerType>()) { 5501 if (const ObjCObjectPointerType *ToPtrTy 5502 = ToTy->getAs<ObjCObjectPointerType>()) 5503 if (const ObjCInterfaceDecl *FromIface = FromPtrTy->getInterfaceDecl()) 5504 if (const ObjCInterfaceDecl *ToIface = ToPtrTy->getInterfaceDecl()) 5505 if (ToPtrTy->getPointeeType().isAtLeastAsQualifiedAs( 5506 FromPtrTy->getPointeeType()) && 5507 FromIface->isSuperClassOf(ToIface)) 5508 BaseToDerivedConversion = 2; 5509 } else if (const ReferenceType *ToRefTy = ToTy->getAs<ReferenceType>()) { 5510 if (ToRefTy->getPointeeType().isAtLeastAsQualifiedAs(FromTy) && 5511 !FromTy->isIncompleteType() && 5512 !ToRefTy->getPointeeType()->isIncompleteType() && 5513 S.IsDerivedFrom(ToRefTy->getPointeeType(), FromTy)) 5514 BaseToDerivedConversion = 3; 5515 } 5516 5517 if (BaseToDerivedConversion) { 5518 S.Diag(Fn->getLocation(), 5519 diag::note_ovl_candidate_bad_base_to_derived_conv) 5520 << (unsigned) FnKind << FnDesc 5521 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 5522 << (BaseToDerivedConversion - 1) 5523 << FromTy << ToTy << I+1; 5524 return; 5525 } 5526 5527 // TODO: specialize more based on the kind of mismatch 5528 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_conv) 5529 << (unsigned) FnKind << FnDesc 5530 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 5531 << FromTy << ToTy << (unsigned) isObjectArgument << I+1; 5532} 5533 5534void DiagnoseArityMismatch(Sema &S, OverloadCandidate *Cand, 5535 unsigned NumFormalArgs) { 5536 // TODO: treat calls to a missing default constructor as a special case 5537 5538 FunctionDecl *Fn = Cand->Function; 5539 const FunctionProtoType *FnTy = Fn->getType()->getAs<FunctionProtoType>(); 5540 5541 unsigned MinParams = Fn->getMinRequiredArguments(); 5542 5543 // at least / at most / exactly 5544 // FIXME: variadic templates "at most" should account for parameter packs 5545 unsigned mode, modeCount; 5546 if (NumFormalArgs < MinParams) { 5547 assert((Cand->FailureKind == ovl_fail_too_few_arguments) || 5548 (Cand->FailureKind == ovl_fail_bad_deduction && 5549 Cand->DeductionFailure.Result == Sema::TDK_TooFewArguments)); 5550 if (MinParams != FnTy->getNumArgs() || FnTy->isVariadic()) 5551 mode = 0; // "at least" 5552 else 5553 mode = 2; // "exactly" 5554 modeCount = MinParams; 5555 } else { 5556 assert((Cand->FailureKind == ovl_fail_too_many_arguments) || 5557 (Cand->FailureKind == ovl_fail_bad_deduction && 5558 Cand->DeductionFailure.Result == Sema::TDK_TooManyArguments)); 5559 if (MinParams != FnTy->getNumArgs()) 5560 mode = 1; // "at most" 5561 else 5562 mode = 2; // "exactly" 5563 modeCount = FnTy->getNumArgs(); 5564 } 5565 5566 std::string Description; 5567 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, Description); 5568 5569 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_arity) 5570 << (unsigned) FnKind << (Fn->getDescribedFunctionTemplate() != 0) << mode 5571 << modeCount << NumFormalArgs; 5572} 5573 5574/// Diagnose a failed template-argument deduction. 5575void DiagnoseBadDeduction(Sema &S, OverloadCandidate *Cand, 5576 Expr **Args, unsigned NumArgs) { 5577 FunctionDecl *Fn = Cand->Function; // pattern 5578 5579 TemplateParameter Param = Cand->DeductionFailure.getTemplateParameter(); 5580 NamedDecl *ParamD; 5581 (ParamD = Param.dyn_cast<TemplateTypeParmDecl*>()) || 5582 (ParamD = Param.dyn_cast<NonTypeTemplateParmDecl*>()) || 5583 (ParamD = Param.dyn_cast<TemplateTemplateParmDecl*>()); 5584 switch (Cand->DeductionFailure.Result) { 5585 case Sema::TDK_Success: 5586 llvm_unreachable("TDK_success while diagnosing bad deduction"); 5587 5588 case Sema::TDK_Incomplete: { 5589 assert(ParamD && "no parameter found for incomplete deduction result"); 5590 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_incomplete_deduction) 5591 << ParamD->getDeclName(); 5592 return; 5593 } 5594 5595 case Sema::TDK_Underqualified: { 5596 assert(ParamD && "no parameter found for bad qualifiers deduction result"); 5597 TemplateTypeParmDecl *TParam = cast<TemplateTypeParmDecl>(ParamD); 5598 5599 QualType Param = Cand->DeductionFailure.getFirstArg()->getAsType(); 5600 5601 // Param will have been canonicalized, but it should just be a 5602 // qualified version of ParamD, so move the qualifiers to that. 5603 QualifierCollector Qs(S.Context); 5604 Qs.strip(Param); 5605 QualType NonCanonParam = Qs.apply(TParam->getTypeForDecl()); 5606 assert(S.Context.hasSameType(Param, NonCanonParam)); 5607 5608 // Arg has also been canonicalized, but there's nothing we can do 5609 // about that. It also doesn't matter as much, because it won't 5610 // have any template parameters in it (because deduction isn't 5611 // done on dependent types). 5612 QualType Arg = Cand->DeductionFailure.getSecondArg()->getAsType(); 5613 5614 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_underqualified) 5615 << ParamD->getDeclName() << Arg << NonCanonParam; 5616 return; 5617 } 5618 5619 case Sema::TDK_Inconsistent: { 5620 assert(ParamD && "no parameter found for inconsistent deduction result"); 5621 int which = 0; 5622 if (isa<TemplateTypeParmDecl>(ParamD)) 5623 which = 0; 5624 else if (isa<NonTypeTemplateParmDecl>(ParamD)) 5625 which = 1; 5626 else { 5627 which = 2; 5628 } 5629 5630 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_inconsistent_deduction) 5631 << which << ParamD->getDeclName() 5632 << *Cand->DeductionFailure.getFirstArg() 5633 << *Cand->DeductionFailure.getSecondArg(); 5634 return; 5635 } 5636 5637 case Sema::TDK_InvalidExplicitArguments: 5638 assert(ParamD && "no parameter found for invalid explicit arguments"); 5639 if (ParamD->getDeclName()) 5640 S.Diag(Fn->getLocation(), 5641 diag::note_ovl_candidate_explicit_arg_mismatch_named) 5642 << ParamD->getDeclName(); 5643 else { 5644 int index = 0; 5645 if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(ParamD)) 5646 index = TTP->getIndex(); 5647 else if (NonTypeTemplateParmDecl *NTTP 5648 = dyn_cast<NonTypeTemplateParmDecl>(ParamD)) 5649 index = NTTP->getIndex(); 5650 else 5651 index = cast<TemplateTemplateParmDecl>(ParamD)->getIndex(); 5652 S.Diag(Fn->getLocation(), 5653 diag::note_ovl_candidate_explicit_arg_mismatch_unnamed) 5654 << (index + 1); 5655 } 5656 return; 5657 5658 case Sema::TDK_TooManyArguments: 5659 case Sema::TDK_TooFewArguments: 5660 DiagnoseArityMismatch(S, Cand, NumArgs); 5661 return; 5662 5663 case Sema::TDK_InstantiationDepth: 5664 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_instantiation_depth); 5665 return; 5666 5667 case Sema::TDK_SubstitutionFailure: { 5668 std::string ArgString; 5669 if (TemplateArgumentList *Args 5670 = Cand->DeductionFailure.getTemplateArgumentList()) 5671 ArgString = S.getTemplateArgumentBindingsText( 5672 Fn->getDescribedFunctionTemplate()->getTemplateParameters(), 5673 *Args); 5674 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_substitution_failure) 5675 << ArgString; 5676 return; 5677 } 5678 5679 // TODO: diagnose these individually, then kill off 5680 // note_ovl_candidate_bad_deduction, which is uselessly vague. 5681 case Sema::TDK_NonDeducedMismatch: 5682 case Sema::TDK_FailedOverloadResolution: 5683 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_deduction); 5684 return; 5685 } 5686} 5687 5688/// Generates a 'note' diagnostic for an overload candidate. We've 5689/// already generated a primary error at the call site. 5690/// 5691/// It really does need to be a single diagnostic with its caret 5692/// pointed at the candidate declaration. Yes, this creates some 5693/// major challenges of technical writing. Yes, this makes pointing 5694/// out problems with specific arguments quite awkward. It's still 5695/// better than generating twenty screens of text for every failed 5696/// overload. 5697/// 5698/// It would be great to be able to express per-candidate problems 5699/// more richly for those diagnostic clients that cared, but we'd 5700/// still have to be just as careful with the default diagnostics. 5701void NoteFunctionCandidate(Sema &S, OverloadCandidate *Cand, 5702 Expr **Args, unsigned NumArgs) { 5703 FunctionDecl *Fn = Cand->Function; 5704 5705 // Note deleted candidates, but only if they're viable. 5706 if (Cand->Viable && (Fn->isDeleted() || Fn->hasAttr<UnavailableAttr>())) { 5707 std::string FnDesc; 5708 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, FnDesc); 5709 5710 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_deleted) 5711 << FnKind << FnDesc << Fn->isDeleted(); 5712 return; 5713 } 5714 5715 // We don't really have anything else to say about viable candidates. 5716 if (Cand->Viable) { 5717 S.NoteOverloadCandidate(Fn); 5718 return; 5719 } 5720 5721 switch (Cand->FailureKind) { 5722 case ovl_fail_too_many_arguments: 5723 case ovl_fail_too_few_arguments: 5724 return DiagnoseArityMismatch(S, Cand, NumArgs); 5725 5726 case ovl_fail_bad_deduction: 5727 return DiagnoseBadDeduction(S, Cand, Args, NumArgs); 5728 5729 case ovl_fail_trivial_conversion: 5730 case ovl_fail_bad_final_conversion: 5731 case ovl_fail_final_conversion_not_exact: 5732 return S.NoteOverloadCandidate(Fn); 5733 5734 case ovl_fail_bad_conversion: { 5735 unsigned I = (Cand->IgnoreObjectArgument ? 1 : 0); 5736 for (unsigned N = Cand->Conversions.size(); I != N; ++I) 5737 if (Cand->Conversions[I].isBad()) 5738 return DiagnoseBadConversion(S, Cand, I); 5739 5740 // FIXME: this currently happens when we're called from SemaInit 5741 // when user-conversion overload fails. Figure out how to handle 5742 // those conditions and diagnose them well. 5743 return S.NoteOverloadCandidate(Fn); 5744 } 5745 } 5746} 5747 5748void NoteSurrogateCandidate(Sema &S, OverloadCandidate *Cand) { 5749 // Desugar the type of the surrogate down to a function type, 5750 // retaining as many typedefs as possible while still showing 5751 // the function type (and, therefore, its parameter types). 5752 QualType FnType = Cand->Surrogate->getConversionType(); 5753 bool isLValueReference = false; 5754 bool isRValueReference = false; 5755 bool isPointer = false; 5756 if (const LValueReferenceType *FnTypeRef = 5757 FnType->getAs<LValueReferenceType>()) { 5758 FnType = FnTypeRef->getPointeeType(); 5759 isLValueReference = true; 5760 } else if (const RValueReferenceType *FnTypeRef = 5761 FnType->getAs<RValueReferenceType>()) { 5762 FnType = FnTypeRef->getPointeeType(); 5763 isRValueReference = true; 5764 } 5765 if (const PointerType *FnTypePtr = FnType->getAs<PointerType>()) { 5766 FnType = FnTypePtr->getPointeeType(); 5767 isPointer = true; 5768 } 5769 // Desugar down to a function type. 5770 FnType = QualType(FnType->getAs<FunctionType>(), 0); 5771 // Reconstruct the pointer/reference as appropriate. 5772 if (isPointer) FnType = S.Context.getPointerType(FnType); 5773 if (isRValueReference) FnType = S.Context.getRValueReferenceType(FnType); 5774 if (isLValueReference) FnType = S.Context.getLValueReferenceType(FnType); 5775 5776 S.Diag(Cand->Surrogate->getLocation(), diag::note_ovl_surrogate_cand) 5777 << FnType; 5778} 5779 5780void NoteBuiltinOperatorCandidate(Sema &S, 5781 const char *Opc, 5782 SourceLocation OpLoc, 5783 OverloadCandidate *Cand) { 5784 assert(Cand->Conversions.size() <= 2 && "builtin operator is not binary"); 5785 std::string TypeStr("operator"); 5786 TypeStr += Opc; 5787 TypeStr += "("; 5788 TypeStr += Cand->BuiltinTypes.ParamTypes[0].getAsString(); 5789 if (Cand->Conversions.size() == 1) { 5790 TypeStr += ")"; 5791 S.Diag(OpLoc, diag::note_ovl_builtin_unary_candidate) << TypeStr; 5792 } else { 5793 TypeStr += ", "; 5794 TypeStr += Cand->BuiltinTypes.ParamTypes[1].getAsString(); 5795 TypeStr += ")"; 5796 S.Diag(OpLoc, diag::note_ovl_builtin_binary_candidate) << TypeStr; 5797 } 5798} 5799 5800void NoteAmbiguousUserConversions(Sema &S, SourceLocation OpLoc, 5801 OverloadCandidate *Cand) { 5802 unsigned NoOperands = Cand->Conversions.size(); 5803 for (unsigned ArgIdx = 0; ArgIdx < NoOperands; ++ArgIdx) { 5804 const ImplicitConversionSequence &ICS = Cand->Conversions[ArgIdx]; 5805 if (ICS.isBad()) break; // all meaningless after first invalid 5806 if (!ICS.isAmbiguous()) continue; 5807 5808 S.DiagnoseAmbiguousConversion(ICS, OpLoc, 5809 S.PDiag(diag::note_ambiguous_type_conversion)); 5810 } 5811} 5812 5813SourceLocation GetLocationForCandidate(const OverloadCandidate *Cand) { 5814 if (Cand->Function) 5815 return Cand->Function->getLocation(); 5816 if (Cand->IsSurrogate) 5817 return Cand->Surrogate->getLocation(); 5818 return SourceLocation(); 5819} 5820 5821struct CompareOverloadCandidatesForDisplay { 5822 Sema &S; 5823 CompareOverloadCandidatesForDisplay(Sema &S) : S(S) {} 5824 5825 bool operator()(const OverloadCandidate *L, 5826 const OverloadCandidate *R) { 5827 // Fast-path this check. 5828 if (L == R) return false; 5829 5830 // Order first by viability. 5831 if (L->Viable) { 5832 if (!R->Viable) return true; 5833 5834 // TODO: introduce a tri-valued comparison for overload 5835 // candidates. Would be more worthwhile if we had a sort 5836 // that could exploit it. 5837 if (S.isBetterOverloadCandidate(*L, *R, SourceLocation())) return true; 5838 if (S.isBetterOverloadCandidate(*R, *L, SourceLocation())) return false; 5839 } else if (R->Viable) 5840 return false; 5841 5842 assert(L->Viable == R->Viable); 5843 5844 // Criteria by which we can sort non-viable candidates: 5845 if (!L->Viable) { 5846 // 1. Arity mismatches come after other candidates. 5847 if (L->FailureKind == ovl_fail_too_many_arguments || 5848 L->FailureKind == ovl_fail_too_few_arguments) 5849 return false; 5850 if (R->FailureKind == ovl_fail_too_many_arguments || 5851 R->FailureKind == ovl_fail_too_few_arguments) 5852 return true; 5853 5854 // 2. Bad conversions come first and are ordered by the number 5855 // of bad conversions and quality of good conversions. 5856 if (L->FailureKind == ovl_fail_bad_conversion) { 5857 if (R->FailureKind != ovl_fail_bad_conversion) 5858 return true; 5859 5860 // If there's any ordering between the defined conversions... 5861 // FIXME: this might not be transitive. 5862 assert(L->Conversions.size() == R->Conversions.size()); 5863 5864 int leftBetter = 0; 5865 unsigned I = (L->IgnoreObjectArgument || R->IgnoreObjectArgument); 5866 for (unsigned E = L->Conversions.size(); I != E; ++I) { 5867 switch (S.CompareImplicitConversionSequences(L->Conversions[I], 5868 R->Conversions[I])) { 5869 case ImplicitConversionSequence::Better: 5870 leftBetter++; 5871 break; 5872 5873 case ImplicitConversionSequence::Worse: 5874 leftBetter--; 5875 break; 5876 5877 case ImplicitConversionSequence::Indistinguishable: 5878 break; 5879 } 5880 } 5881 if (leftBetter > 0) return true; 5882 if (leftBetter < 0) return false; 5883 5884 } else if (R->FailureKind == ovl_fail_bad_conversion) 5885 return false; 5886 5887 // TODO: others? 5888 } 5889 5890 // Sort everything else by location. 5891 SourceLocation LLoc = GetLocationForCandidate(L); 5892 SourceLocation RLoc = GetLocationForCandidate(R); 5893 5894 // Put candidates without locations (e.g. builtins) at the end. 5895 if (LLoc.isInvalid()) return false; 5896 if (RLoc.isInvalid()) return true; 5897 5898 return S.SourceMgr.isBeforeInTranslationUnit(LLoc, RLoc); 5899 } 5900}; 5901 5902/// CompleteNonViableCandidate - Normally, overload resolution only 5903/// computes up to the first 5904void CompleteNonViableCandidate(Sema &S, OverloadCandidate *Cand, 5905 Expr **Args, unsigned NumArgs) { 5906 assert(!Cand->Viable); 5907 5908 // Don't do anything on failures other than bad conversion. 5909 if (Cand->FailureKind != ovl_fail_bad_conversion) return; 5910 5911 // Skip forward to the first bad conversion. 5912 unsigned ConvIdx = (Cand->IgnoreObjectArgument ? 1 : 0); 5913 unsigned ConvCount = Cand->Conversions.size(); 5914 while (true) { 5915 assert(ConvIdx != ConvCount && "no bad conversion in candidate"); 5916 ConvIdx++; 5917 if (Cand->Conversions[ConvIdx - 1].isBad()) 5918 break; 5919 } 5920 5921 if (ConvIdx == ConvCount) 5922 return; 5923 5924 assert(!Cand->Conversions[ConvIdx].isInitialized() && 5925 "remaining conversion is initialized?"); 5926 5927 // FIXME: this should probably be preserved from the overload 5928 // operation somehow. 5929 bool SuppressUserConversions = false; 5930 5931 const FunctionProtoType* Proto; 5932 unsigned ArgIdx = ConvIdx; 5933 5934 if (Cand->IsSurrogate) { 5935 QualType ConvType 5936 = Cand->Surrogate->getConversionType().getNonReferenceType(); 5937 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 5938 ConvType = ConvPtrType->getPointeeType(); 5939 Proto = ConvType->getAs<FunctionProtoType>(); 5940 ArgIdx--; 5941 } else if (Cand->Function) { 5942 Proto = Cand->Function->getType()->getAs<FunctionProtoType>(); 5943 if (isa<CXXMethodDecl>(Cand->Function) && 5944 !isa<CXXConstructorDecl>(Cand->Function)) 5945 ArgIdx--; 5946 } else { 5947 // Builtin binary operator with a bad first conversion. 5948 assert(ConvCount <= 3); 5949 for (; ConvIdx != ConvCount; ++ConvIdx) 5950 Cand->Conversions[ConvIdx] 5951 = TryCopyInitialization(S, Args[ConvIdx], 5952 Cand->BuiltinTypes.ParamTypes[ConvIdx], 5953 SuppressUserConversions, 5954 /*InOverloadResolution*/ true); 5955 return; 5956 } 5957 5958 // Fill in the rest of the conversions. 5959 unsigned NumArgsInProto = Proto->getNumArgs(); 5960 for (; ConvIdx != ConvCount; ++ConvIdx, ++ArgIdx) { 5961 if (ArgIdx < NumArgsInProto) 5962 Cand->Conversions[ConvIdx] 5963 = TryCopyInitialization(S, Args[ArgIdx], Proto->getArgType(ArgIdx), 5964 SuppressUserConversions, 5965 /*InOverloadResolution=*/true); 5966 else 5967 Cand->Conversions[ConvIdx].setEllipsis(); 5968 } 5969} 5970 5971} // end anonymous namespace 5972 5973/// PrintOverloadCandidates - When overload resolution fails, prints 5974/// diagnostic messages containing the candidates in the candidate 5975/// set. 5976void 5977Sema::PrintOverloadCandidates(OverloadCandidateSet& CandidateSet, 5978 OverloadCandidateDisplayKind OCD, 5979 Expr **Args, unsigned NumArgs, 5980 const char *Opc, 5981 SourceLocation OpLoc) { 5982 // Sort the candidates by viability and position. Sorting directly would 5983 // be prohibitive, so we make a set of pointers and sort those. 5984 llvm::SmallVector<OverloadCandidate*, 32> Cands; 5985 if (OCD == OCD_AllCandidates) Cands.reserve(CandidateSet.size()); 5986 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 5987 LastCand = CandidateSet.end(); 5988 Cand != LastCand; ++Cand) { 5989 if (Cand->Viable) 5990 Cands.push_back(Cand); 5991 else if (OCD == OCD_AllCandidates) { 5992 CompleteNonViableCandidate(*this, Cand, Args, NumArgs); 5993 if (Cand->Function || Cand->IsSurrogate) 5994 Cands.push_back(Cand); 5995 // Otherwise, this a non-viable builtin candidate. We do not, in general, 5996 // want to list every possible builtin candidate. 5997 } 5998 } 5999 6000 std::sort(Cands.begin(), Cands.end(), 6001 CompareOverloadCandidatesForDisplay(*this)); 6002 6003 bool ReportedAmbiguousConversions = false; 6004 6005 llvm::SmallVectorImpl<OverloadCandidate*>::iterator I, E; 6006 const Diagnostic::OverloadsShown ShowOverloads = Diags.getShowOverloads(); 6007 unsigned CandsShown = 0; 6008 for (I = Cands.begin(), E = Cands.end(); I != E; ++I) { 6009 OverloadCandidate *Cand = *I; 6010 6011 // Set an arbitrary limit on the number of candidate functions we'll spam 6012 // the user with. FIXME: This limit should depend on details of the 6013 // candidate list. 6014 if (CandsShown >= 4 && ShowOverloads == Diagnostic::Ovl_Best) { 6015 break; 6016 } 6017 ++CandsShown; 6018 6019 if (Cand->Function) 6020 NoteFunctionCandidate(*this, Cand, Args, NumArgs); 6021 else if (Cand->IsSurrogate) 6022 NoteSurrogateCandidate(*this, Cand); 6023 else { 6024 assert(Cand->Viable && 6025 "Non-viable built-in candidates are not added to Cands."); 6026 // Generally we only see ambiguities including viable builtin 6027 // operators if overload resolution got screwed up by an 6028 // ambiguous user-defined conversion. 6029 // 6030 // FIXME: It's quite possible for different conversions to see 6031 // different ambiguities, though. 6032 if (!ReportedAmbiguousConversions) { 6033 NoteAmbiguousUserConversions(*this, OpLoc, Cand); 6034 ReportedAmbiguousConversions = true; 6035 } 6036 6037 // If this is a viable builtin, print it. 6038 NoteBuiltinOperatorCandidate(*this, Opc, OpLoc, Cand); 6039 } 6040 } 6041 6042 if (I != E) 6043 Diag(OpLoc, diag::note_ovl_too_many_candidates) << int(E - I); 6044} 6045 6046static bool CheckUnresolvedAccess(Sema &S, OverloadExpr *E, DeclAccessPair D) { 6047 if (isa<UnresolvedLookupExpr>(E)) 6048 return S.CheckUnresolvedLookupAccess(cast<UnresolvedLookupExpr>(E), D); 6049 6050 return S.CheckUnresolvedMemberAccess(cast<UnresolvedMemberExpr>(E), D); 6051} 6052 6053/// ResolveAddressOfOverloadedFunction - Try to resolve the address of 6054/// an overloaded function (C++ [over.over]), where @p From is an 6055/// expression with overloaded function type and @p ToType is the type 6056/// we're trying to resolve to. For example: 6057/// 6058/// @code 6059/// int f(double); 6060/// int f(int); 6061/// 6062/// int (*pfd)(double) = f; // selects f(double) 6063/// @endcode 6064/// 6065/// This routine returns the resulting FunctionDecl if it could be 6066/// resolved, and NULL otherwise. When @p Complain is true, this 6067/// routine will emit diagnostics if there is an error. 6068FunctionDecl * 6069Sema::ResolveAddressOfOverloadedFunction(Expr *From, QualType ToType, 6070 bool Complain, 6071 DeclAccessPair &FoundResult) { 6072 QualType FunctionType = ToType; 6073 bool IsMember = false; 6074 if (const PointerType *ToTypePtr = ToType->getAs<PointerType>()) 6075 FunctionType = ToTypePtr->getPointeeType(); 6076 else if (const ReferenceType *ToTypeRef = ToType->getAs<ReferenceType>()) 6077 FunctionType = ToTypeRef->getPointeeType(); 6078 else if (const MemberPointerType *MemTypePtr = 6079 ToType->getAs<MemberPointerType>()) { 6080 FunctionType = MemTypePtr->getPointeeType(); 6081 IsMember = true; 6082 } 6083 6084 // C++ [over.over]p1: 6085 // [...] [Note: any redundant set of parentheses surrounding the 6086 // overloaded function name is ignored (5.1). ] 6087 // C++ [over.over]p1: 6088 // [...] The overloaded function name can be preceded by the & 6089 // operator. 6090 OverloadExpr *OvlExpr = OverloadExpr::find(From).getPointer(); 6091 TemplateArgumentListInfo ETABuffer, *ExplicitTemplateArgs = 0; 6092 if (OvlExpr->hasExplicitTemplateArgs()) { 6093 OvlExpr->getExplicitTemplateArgs().copyInto(ETABuffer); 6094 ExplicitTemplateArgs = &ETABuffer; 6095 } 6096 6097 // We expect a pointer or reference to function, or a function pointer. 6098 FunctionType = Context.getCanonicalType(FunctionType).getUnqualifiedType(); 6099 if (!FunctionType->isFunctionType()) { 6100 if (Complain) 6101 Diag(From->getLocStart(), diag::err_addr_ovl_not_func_ptrref) 6102 << OvlExpr->getName() << ToType; 6103 6104 return 0; 6105 } 6106 6107 assert(From->getType() == Context.OverloadTy); 6108 6109 // Look through all of the overloaded functions, searching for one 6110 // whose type matches exactly. 6111 llvm::SmallVector<std::pair<DeclAccessPair, FunctionDecl*>, 4> Matches; 6112 llvm::SmallVector<FunctionDecl *, 4> NonMatches; 6113 6114 bool FoundNonTemplateFunction = false; 6115 for (UnresolvedSetIterator I = OvlExpr->decls_begin(), 6116 E = OvlExpr->decls_end(); I != E; ++I) { 6117 // Look through any using declarations to find the underlying function. 6118 NamedDecl *Fn = (*I)->getUnderlyingDecl(); 6119 6120 // C++ [over.over]p3: 6121 // Non-member functions and static member functions match 6122 // targets of type "pointer-to-function" or "reference-to-function." 6123 // Nonstatic member functions match targets of 6124 // type "pointer-to-member-function." 6125 // Note that according to DR 247, the containing class does not matter. 6126 6127 if (FunctionTemplateDecl *FunctionTemplate 6128 = dyn_cast<FunctionTemplateDecl>(Fn)) { 6129 if (CXXMethodDecl *Method 6130 = dyn_cast<CXXMethodDecl>(FunctionTemplate->getTemplatedDecl())) { 6131 // Skip non-static function templates when converting to pointer, and 6132 // static when converting to member pointer. 6133 if (Method->isStatic() == IsMember) 6134 continue; 6135 } else if (IsMember) 6136 continue; 6137 6138 // C++ [over.over]p2: 6139 // If the name is a function template, template argument deduction is 6140 // done (14.8.2.2), and if the argument deduction succeeds, the 6141 // resulting template argument list is used to generate a single 6142 // function template specialization, which is added to the set of 6143 // overloaded functions considered. 6144 // FIXME: We don't really want to build the specialization here, do we? 6145 FunctionDecl *Specialization = 0; 6146 TemplateDeductionInfo Info(Context, OvlExpr->getNameLoc()); 6147 if (TemplateDeductionResult Result 6148 = DeduceTemplateArguments(FunctionTemplate, ExplicitTemplateArgs, 6149 FunctionType, Specialization, Info)) { 6150 // FIXME: make a note of the failed deduction for diagnostics. 6151 (void)Result; 6152 } else { 6153 // FIXME: If the match isn't exact, shouldn't we just drop this as 6154 // a candidate? Find a testcase before changing the code. 6155 assert(FunctionType 6156 == Context.getCanonicalType(Specialization->getType())); 6157 Matches.push_back(std::make_pair(I.getPair(), 6158 cast<FunctionDecl>(Specialization->getCanonicalDecl()))); 6159 } 6160 6161 continue; 6162 } 6163 6164 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 6165 // Skip non-static functions when converting to pointer, and static 6166 // when converting to member pointer. 6167 if (Method->isStatic() == IsMember) 6168 continue; 6169 6170 // If we have explicit template arguments, skip non-templates. 6171 if (OvlExpr->hasExplicitTemplateArgs()) 6172 continue; 6173 } else if (IsMember) 6174 continue; 6175 6176 if (FunctionDecl *FunDecl = dyn_cast<FunctionDecl>(Fn)) { 6177 QualType ResultTy; 6178 if (Context.hasSameUnqualifiedType(FunctionType, FunDecl->getType()) || 6179 IsNoReturnConversion(Context, FunDecl->getType(), FunctionType, 6180 ResultTy)) { 6181 Matches.push_back(std::make_pair(I.getPair(), 6182 cast<FunctionDecl>(FunDecl->getCanonicalDecl()))); 6183 FoundNonTemplateFunction = true; 6184 } 6185 } 6186 } 6187 6188 // If there were 0 or 1 matches, we're done. 6189 if (Matches.empty()) { 6190 if (Complain) { 6191 Diag(From->getLocStart(), diag::err_addr_ovl_no_viable) 6192 << OvlExpr->getName() << FunctionType; 6193 for (UnresolvedSetIterator I = OvlExpr->decls_begin(), 6194 E = OvlExpr->decls_end(); 6195 I != E; ++I) 6196 if (FunctionDecl *F = dyn_cast<FunctionDecl>((*I)->getUnderlyingDecl())) 6197 NoteOverloadCandidate(F); 6198 } 6199 6200 return 0; 6201 } else if (Matches.size() == 1) { 6202 FunctionDecl *Result = Matches[0].second; 6203 FoundResult = Matches[0].first; 6204 MarkDeclarationReferenced(From->getLocStart(), Result); 6205 if (Complain) 6206 CheckAddressOfMemberAccess(OvlExpr, Matches[0].first); 6207 return Result; 6208 } 6209 6210 // C++ [over.over]p4: 6211 // If more than one function is selected, [...] 6212 if (!FoundNonTemplateFunction) { 6213 // [...] and any given function template specialization F1 is 6214 // eliminated if the set contains a second function template 6215 // specialization whose function template is more specialized 6216 // than the function template of F1 according to the partial 6217 // ordering rules of 14.5.5.2. 6218 6219 // The algorithm specified above is quadratic. We instead use a 6220 // two-pass algorithm (similar to the one used to identify the 6221 // best viable function in an overload set) that identifies the 6222 // best function template (if it exists). 6223 6224 UnresolvedSet<4> MatchesCopy; // TODO: avoid! 6225 for (unsigned I = 0, E = Matches.size(); I != E; ++I) 6226 MatchesCopy.addDecl(Matches[I].second, Matches[I].first.getAccess()); 6227 6228 UnresolvedSetIterator Result = 6229 getMostSpecialized(MatchesCopy.begin(), MatchesCopy.end(), 6230 TPOC_Other, From->getLocStart(), 6231 PDiag(), 6232 PDiag(diag::err_addr_ovl_ambiguous) 6233 << Matches[0].second->getDeclName(), 6234 PDiag(diag::note_ovl_candidate) 6235 << (unsigned) oc_function_template); 6236 assert(Result != MatchesCopy.end() && "no most-specialized template"); 6237 MarkDeclarationReferenced(From->getLocStart(), *Result); 6238 FoundResult = Matches[Result - MatchesCopy.begin()].first; 6239 if (Complain) { 6240 CheckUnresolvedAccess(*this, OvlExpr, FoundResult); 6241 DiagnoseUseOfDecl(FoundResult, OvlExpr->getNameLoc()); 6242 } 6243 return cast<FunctionDecl>(*Result); 6244 } 6245 6246 // [...] any function template specializations in the set are 6247 // eliminated if the set also contains a non-template function, [...] 6248 for (unsigned I = 0, N = Matches.size(); I != N; ) { 6249 if (Matches[I].second->getPrimaryTemplate() == 0) 6250 ++I; 6251 else { 6252 Matches[I] = Matches[--N]; 6253 Matches.set_size(N); 6254 } 6255 } 6256 6257 // [...] After such eliminations, if any, there shall remain exactly one 6258 // selected function. 6259 if (Matches.size() == 1) { 6260 MarkDeclarationReferenced(From->getLocStart(), Matches[0].second); 6261 FoundResult = Matches[0].first; 6262 if (Complain) { 6263 CheckUnresolvedAccess(*this, OvlExpr, Matches[0].first); 6264 DiagnoseUseOfDecl(Matches[0].first, OvlExpr->getNameLoc()); 6265 } 6266 return cast<FunctionDecl>(Matches[0].second); 6267 } 6268 6269 // FIXME: We should probably return the same thing that BestViableFunction 6270 // returns (even if we issue the diagnostics here). 6271 Diag(From->getLocStart(), diag::err_addr_ovl_ambiguous) 6272 << Matches[0].second->getDeclName(); 6273 for (unsigned I = 0, E = Matches.size(); I != E; ++I) 6274 NoteOverloadCandidate(Matches[I].second); 6275 return 0; 6276} 6277 6278/// \brief Given an expression that refers to an overloaded function, try to 6279/// resolve that overloaded function expression down to a single function. 6280/// 6281/// This routine can only resolve template-ids that refer to a single function 6282/// template, where that template-id refers to a single template whose template 6283/// arguments are either provided by the template-id or have defaults, 6284/// as described in C++0x [temp.arg.explicit]p3. 6285FunctionDecl *Sema::ResolveSingleFunctionTemplateSpecialization(Expr *From) { 6286 // C++ [over.over]p1: 6287 // [...] [Note: any redundant set of parentheses surrounding the 6288 // overloaded function name is ignored (5.1). ] 6289 // C++ [over.over]p1: 6290 // [...] The overloaded function name can be preceded by the & 6291 // operator. 6292 6293 if (From->getType() != Context.OverloadTy) 6294 return 0; 6295 6296 OverloadExpr *OvlExpr = OverloadExpr::find(From).getPointer(); 6297 6298 // If we didn't actually find any template-ids, we're done. 6299 if (!OvlExpr->hasExplicitTemplateArgs()) 6300 return 0; 6301 6302 TemplateArgumentListInfo ExplicitTemplateArgs; 6303 OvlExpr->getExplicitTemplateArgs().copyInto(ExplicitTemplateArgs); 6304 6305 // Look through all of the overloaded functions, searching for one 6306 // whose type matches exactly. 6307 FunctionDecl *Matched = 0; 6308 for (UnresolvedSetIterator I = OvlExpr->decls_begin(), 6309 E = OvlExpr->decls_end(); I != E; ++I) { 6310 // C++0x [temp.arg.explicit]p3: 6311 // [...] In contexts where deduction is done and fails, or in contexts 6312 // where deduction is not done, if a template argument list is 6313 // specified and it, along with any default template arguments, 6314 // identifies a single function template specialization, then the 6315 // template-id is an lvalue for the function template specialization. 6316 FunctionTemplateDecl *FunctionTemplate 6317 = cast<FunctionTemplateDecl>((*I)->getUnderlyingDecl()); 6318 6319 // C++ [over.over]p2: 6320 // If the name is a function template, template argument deduction is 6321 // done (14.8.2.2), and if the argument deduction succeeds, the 6322 // resulting template argument list is used to generate a single 6323 // function template specialization, which is added to the set of 6324 // overloaded functions considered. 6325 FunctionDecl *Specialization = 0; 6326 TemplateDeductionInfo Info(Context, OvlExpr->getNameLoc()); 6327 if (TemplateDeductionResult Result 6328 = DeduceTemplateArguments(FunctionTemplate, &ExplicitTemplateArgs, 6329 Specialization, Info)) { 6330 // FIXME: make a note of the failed deduction for diagnostics. 6331 (void)Result; 6332 continue; 6333 } 6334 6335 // Multiple matches; we can't resolve to a single declaration. 6336 if (Matched) 6337 return 0; 6338 6339 Matched = Specialization; 6340 } 6341 6342 return Matched; 6343} 6344 6345/// \brief Add a single candidate to the overload set. 6346static void AddOverloadedCallCandidate(Sema &S, 6347 DeclAccessPair FoundDecl, 6348 const TemplateArgumentListInfo *ExplicitTemplateArgs, 6349 Expr **Args, unsigned NumArgs, 6350 OverloadCandidateSet &CandidateSet, 6351 bool PartialOverloading) { 6352 NamedDecl *Callee = FoundDecl.getDecl(); 6353 if (isa<UsingShadowDecl>(Callee)) 6354 Callee = cast<UsingShadowDecl>(Callee)->getTargetDecl(); 6355 6356 if (FunctionDecl *Func = dyn_cast<FunctionDecl>(Callee)) { 6357 assert(!ExplicitTemplateArgs && "Explicit template arguments?"); 6358 S.AddOverloadCandidate(Func, FoundDecl, Args, NumArgs, CandidateSet, 6359 false, PartialOverloading); 6360 return; 6361 } 6362 6363 if (FunctionTemplateDecl *FuncTemplate 6364 = dyn_cast<FunctionTemplateDecl>(Callee)) { 6365 S.AddTemplateOverloadCandidate(FuncTemplate, FoundDecl, 6366 ExplicitTemplateArgs, 6367 Args, NumArgs, CandidateSet); 6368 return; 6369 } 6370 6371 assert(false && "unhandled case in overloaded call candidate"); 6372 6373 // do nothing? 6374} 6375 6376/// \brief Add the overload candidates named by callee and/or found by argument 6377/// dependent lookup to the given overload set. 6378void Sema::AddOverloadedCallCandidates(UnresolvedLookupExpr *ULE, 6379 Expr **Args, unsigned NumArgs, 6380 OverloadCandidateSet &CandidateSet, 6381 bool PartialOverloading) { 6382 6383#ifndef NDEBUG 6384 // Verify that ArgumentDependentLookup is consistent with the rules 6385 // in C++0x [basic.lookup.argdep]p3: 6386 // 6387 // Let X be the lookup set produced by unqualified lookup (3.4.1) 6388 // and let Y be the lookup set produced by argument dependent 6389 // lookup (defined as follows). If X contains 6390 // 6391 // -- a declaration of a class member, or 6392 // 6393 // -- a block-scope function declaration that is not a 6394 // using-declaration, or 6395 // 6396 // -- a declaration that is neither a function or a function 6397 // template 6398 // 6399 // then Y is empty. 6400 6401 if (ULE->requiresADL()) { 6402 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(), 6403 E = ULE->decls_end(); I != E; ++I) { 6404 assert(!(*I)->getDeclContext()->isRecord()); 6405 assert(isa<UsingShadowDecl>(*I) || 6406 !(*I)->getDeclContext()->isFunctionOrMethod()); 6407 assert((*I)->getUnderlyingDecl()->isFunctionOrFunctionTemplate()); 6408 } 6409 } 6410#endif 6411 6412 // It would be nice to avoid this copy. 6413 TemplateArgumentListInfo TABuffer; 6414 const TemplateArgumentListInfo *ExplicitTemplateArgs = 0; 6415 if (ULE->hasExplicitTemplateArgs()) { 6416 ULE->copyTemplateArgumentsInto(TABuffer); 6417 ExplicitTemplateArgs = &TABuffer; 6418 } 6419 6420 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(), 6421 E = ULE->decls_end(); I != E; ++I) 6422 AddOverloadedCallCandidate(*this, I.getPair(), ExplicitTemplateArgs, 6423 Args, NumArgs, CandidateSet, 6424 PartialOverloading); 6425 6426 if (ULE->requiresADL()) 6427 AddArgumentDependentLookupCandidates(ULE->getName(), /*Operator*/ false, 6428 Args, NumArgs, 6429 ExplicitTemplateArgs, 6430 CandidateSet, 6431 PartialOverloading); 6432} 6433 6434/// Attempts to recover from a call where no functions were found. 6435/// 6436/// Returns true if new candidates were found. 6437static Sema::OwningExprResult 6438BuildRecoveryCallExpr(Sema &SemaRef, Scope *S, Expr *Fn, 6439 UnresolvedLookupExpr *ULE, 6440 SourceLocation LParenLoc, 6441 Expr **Args, unsigned NumArgs, 6442 SourceLocation *CommaLocs, 6443 SourceLocation RParenLoc) { 6444 6445 CXXScopeSpec SS; 6446 if (ULE->getQualifier()) { 6447 SS.setScopeRep(ULE->getQualifier()); 6448 SS.setRange(ULE->getQualifierRange()); 6449 } 6450 6451 TemplateArgumentListInfo TABuffer; 6452 const TemplateArgumentListInfo *ExplicitTemplateArgs = 0; 6453 if (ULE->hasExplicitTemplateArgs()) { 6454 ULE->copyTemplateArgumentsInto(TABuffer); 6455 ExplicitTemplateArgs = &TABuffer; 6456 } 6457 6458 LookupResult R(SemaRef, ULE->getName(), ULE->getNameLoc(), 6459 Sema::LookupOrdinaryName); 6460 if (SemaRef.DiagnoseEmptyLookup(S, SS, R, Sema::CTC_Expression)) 6461 return SemaRef.ExprError(); 6462 6463 assert(!R.empty() && "lookup results empty despite recovery"); 6464 6465 // Build an implicit member call if appropriate. Just drop the 6466 // casts and such from the call, we don't really care. 6467 Sema::OwningExprResult NewFn = SemaRef.ExprError(); 6468 if ((*R.begin())->isCXXClassMember()) 6469 NewFn = SemaRef.BuildPossibleImplicitMemberExpr(SS, R, ExplicitTemplateArgs); 6470 else if (ExplicitTemplateArgs) 6471 NewFn = SemaRef.BuildTemplateIdExpr(SS, R, false, *ExplicitTemplateArgs); 6472 else 6473 NewFn = SemaRef.BuildDeclarationNameExpr(SS, R, false); 6474 6475 if (NewFn.isInvalid()) 6476 return SemaRef.ExprError(); 6477 6478 // This shouldn't cause an infinite loop because we're giving it 6479 // an expression with non-empty lookup results, which should never 6480 // end up here. 6481 return SemaRef.ActOnCallExpr(/*Scope*/ 0, move(NewFn), LParenLoc, 6482 Sema::MultiExprArg(SemaRef, (void**) Args, NumArgs), 6483 CommaLocs, RParenLoc); 6484} 6485 6486/// ResolveOverloadedCallFn - Given the call expression that calls Fn 6487/// (which eventually refers to the declaration Func) and the call 6488/// arguments Args/NumArgs, attempt to resolve the function call down 6489/// to a specific function. If overload resolution succeeds, returns 6490/// the function declaration produced by overload 6491/// resolution. Otherwise, emits diagnostics, deletes all of the 6492/// arguments and Fn, and returns NULL. 6493Sema::OwningExprResult 6494Sema::BuildOverloadedCallExpr(Scope *S, Expr *Fn, UnresolvedLookupExpr *ULE, 6495 SourceLocation LParenLoc, 6496 Expr **Args, unsigned NumArgs, 6497 SourceLocation *CommaLocs, 6498 SourceLocation RParenLoc) { 6499#ifndef NDEBUG 6500 if (ULE->requiresADL()) { 6501 // To do ADL, we must have found an unqualified name. 6502 assert(!ULE->getQualifier() && "qualified name with ADL"); 6503 6504 // We don't perform ADL for implicit declarations of builtins. 6505 // Verify that this was correctly set up. 6506 FunctionDecl *F; 6507 if (ULE->decls_begin() + 1 == ULE->decls_end() && 6508 (F = dyn_cast<FunctionDecl>(*ULE->decls_begin())) && 6509 F->getBuiltinID() && F->isImplicit()) 6510 assert(0 && "performing ADL for builtin"); 6511 6512 // We don't perform ADL in C. 6513 assert(getLangOptions().CPlusPlus && "ADL enabled in C"); 6514 } 6515#endif 6516 6517 OverloadCandidateSet CandidateSet(Fn->getExprLoc()); 6518 6519 // Add the functions denoted by the callee to the set of candidate 6520 // functions, including those from argument-dependent lookup. 6521 AddOverloadedCallCandidates(ULE, Args, NumArgs, CandidateSet); 6522 6523 // If we found nothing, try to recover. 6524 // AddRecoveryCallCandidates diagnoses the error itself, so we just 6525 // bailout out if it fails. 6526 if (CandidateSet.empty()) 6527 return BuildRecoveryCallExpr(*this, S, Fn, ULE, LParenLoc, Args, NumArgs, 6528 CommaLocs, RParenLoc); 6529 6530 OverloadCandidateSet::iterator Best; 6531 switch (BestViableFunction(CandidateSet, Fn->getLocStart(), Best)) { 6532 case OR_Success: { 6533 FunctionDecl *FDecl = Best->Function; 6534 CheckUnresolvedLookupAccess(ULE, Best->FoundDecl); 6535 DiagnoseUseOfDecl(Best->FoundDecl, ULE->getNameLoc()); 6536 Fn = FixOverloadedFunctionReference(Fn, Best->FoundDecl, FDecl); 6537 return BuildResolvedCallExpr(Fn, FDecl, LParenLoc, Args, NumArgs, RParenLoc); 6538 } 6539 6540 case OR_No_Viable_Function: 6541 Diag(Fn->getSourceRange().getBegin(), 6542 diag::err_ovl_no_viable_function_in_call) 6543 << ULE->getName() << Fn->getSourceRange(); 6544 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6545 break; 6546 6547 case OR_Ambiguous: 6548 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_ambiguous_call) 6549 << ULE->getName() << Fn->getSourceRange(); 6550 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, NumArgs); 6551 break; 6552 6553 case OR_Deleted: 6554 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_deleted_call) 6555 << Best->Function->isDeleted() 6556 << ULE->getName() 6557 << Fn->getSourceRange(); 6558 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6559 break; 6560 } 6561 6562 // Overload resolution failed. 6563 return ExprError(); 6564} 6565 6566static bool IsOverloaded(const UnresolvedSetImpl &Functions) { 6567 return Functions.size() > 1 || 6568 (Functions.size() == 1 && isa<FunctionTemplateDecl>(*Functions.begin())); 6569} 6570 6571/// \brief Create a unary operation that may resolve to an overloaded 6572/// operator. 6573/// 6574/// \param OpLoc The location of the operator itself (e.g., '*'). 6575/// 6576/// \param OpcIn The UnaryOperator::Opcode that describes this 6577/// operator. 6578/// 6579/// \param Functions The set of non-member functions that will be 6580/// considered by overload resolution. The caller needs to build this 6581/// set based on the context using, e.g., 6582/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 6583/// set should not contain any member functions; those will be added 6584/// by CreateOverloadedUnaryOp(). 6585/// 6586/// \param input The input argument. 6587Sema::OwningExprResult 6588Sema::CreateOverloadedUnaryOp(SourceLocation OpLoc, unsigned OpcIn, 6589 const UnresolvedSetImpl &Fns, 6590 ExprArg input) { 6591 UnaryOperator::Opcode Opc = static_cast<UnaryOperator::Opcode>(OpcIn); 6592 Expr *Input = (Expr *)input.get(); 6593 6594 OverloadedOperatorKind Op = UnaryOperator::getOverloadedOperator(Opc); 6595 assert(Op != OO_None && "Invalid opcode for overloaded unary operator"); 6596 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 6597 6598 Expr *Args[2] = { Input, 0 }; 6599 unsigned NumArgs = 1; 6600 6601 // For post-increment and post-decrement, add the implicit '0' as 6602 // the second argument, so that we know this is a post-increment or 6603 // post-decrement. 6604 if (Opc == UnaryOperator::PostInc || Opc == UnaryOperator::PostDec) { 6605 llvm::APSInt Zero(Context.getTypeSize(Context.IntTy), false); 6606 Args[1] = new (Context) IntegerLiteral(Zero, Context.IntTy, 6607 SourceLocation()); 6608 NumArgs = 2; 6609 } 6610 6611 if (Input->isTypeDependent()) { 6612 if (Fns.empty()) 6613 return Owned(new (Context) UnaryOperator(input.takeAs<Expr>(), 6614 Opc, 6615 Context.DependentTy, 6616 OpLoc)); 6617 6618 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 6619 UnresolvedLookupExpr *Fn 6620 = UnresolvedLookupExpr::Create(Context, /*Dependent*/ true, NamingClass, 6621 0, SourceRange(), OpName, OpLoc, 6622 /*ADL*/ true, IsOverloaded(Fns), 6623 Fns.begin(), Fns.end()); 6624 input.release(); 6625 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 6626 &Args[0], NumArgs, 6627 Context.DependentTy, 6628 OpLoc)); 6629 } 6630 6631 // Build an empty overload set. 6632 OverloadCandidateSet CandidateSet(OpLoc); 6633 6634 // Add the candidates from the given function set. 6635 AddFunctionCandidates(Fns, &Args[0], NumArgs, CandidateSet, false); 6636 6637 // Add operator candidates that are member functions. 6638 AddMemberOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 6639 6640 // Add candidates from ADL. 6641 AddArgumentDependentLookupCandidates(OpName, /*Operator*/ true, 6642 Args, NumArgs, 6643 /*ExplicitTemplateArgs*/ 0, 6644 CandidateSet); 6645 6646 // Add builtin operator candidates. 6647 AddBuiltinOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 6648 6649 // Perform overload resolution. 6650 OverloadCandidateSet::iterator Best; 6651 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 6652 case OR_Success: { 6653 // We found a built-in operator or an overloaded operator. 6654 FunctionDecl *FnDecl = Best->Function; 6655 6656 if (FnDecl) { 6657 // We matched an overloaded operator. Build a call to that 6658 // operator. 6659 6660 // Convert the arguments. 6661 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 6662 CheckMemberOperatorAccess(OpLoc, Args[0], 0, Best->FoundDecl); 6663 6664 if (PerformObjectArgumentInitialization(Input, /*Qualifier=*/0, 6665 Best->FoundDecl, Method)) 6666 return ExprError(); 6667 } else { 6668 // Convert the arguments. 6669 OwningExprResult InputInit 6670 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 6671 FnDecl->getParamDecl(0)), 6672 SourceLocation(), 6673 move(input)); 6674 if (InputInit.isInvalid()) 6675 return ExprError(); 6676 6677 input = move(InputInit); 6678 Input = (Expr *)input.get(); 6679 } 6680 6681 DiagnoseUseOfDecl(Best->FoundDecl, OpLoc); 6682 6683 // Determine the result type 6684 QualType ResultTy = FnDecl->getCallResultType(); 6685 6686 // Build the actual expression node. 6687 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 6688 SourceLocation()); 6689 UsualUnaryConversions(FnExpr); 6690 6691 input.release(); 6692 Args[0] = Input; 6693 ExprOwningPtr<CallExpr> TheCall(this, 6694 new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 6695 Args, NumArgs, ResultTy, OpLoc)); 6696 6697 if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall.get(), 6698 FnDecl)) 6699 return ExprError(); 6700 6701 return MaybeBindToTemporary(TheCall.release()); 6702 } else { 6703 // We matched a built-in operator. Convert the arguments, then 6704 // break out so that we will build the appropriate built-in 6705 // operator node. 6706 if (PerformImplicitConversion(Input, Best->BuiltinTypes.ParamTypes[0], 6707 Best->Conversions[0], AA_Passing)) 6708 return ExprError(); 6709 6710 break; 6711 } 6712 } 6713 6714 case OR_No_Viable_Function: 6715 // No viable function; fall through to handling this as a 6716 // built-in operator, which will produce an error message for us. 6717 break; 6718 6719 case OR_Ambiguous: 6720 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 6721 << UnaryOperator::getOpcodeStr(Opc) 6722 << Input->getSourceRange(); 6723 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, NumArgs, 6724 UnaryOperator::getOpcodeStr(Opc), OpLoc); 6725 return ExprError(); 6726 6727 case OR_Deleted: 6728 Diag(OpLoc, diag::err_ovl_deleted_oper) 6729 << Best->Function->isDeleted() 6730 << UnaryOperator::getOpcodeStr(Opc) 6731 << Input->getSourceRange(); 6732 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6733 return ExprError(); 6734 } 6735 6736 // Either we found no viable overloaded operator or we matched a 6737 // built-in operator. In either case, fall through to trying to 6738 // build a built-in operation. 6739 input.release(); 6740 return CreateBuiltinUnaryOp(OpLoc, Opc, Owned(Input)); 6741} 6742 6743/// \brief Create a binary operation that may resolve to an overloaded 6744/// operator. 6745/// 6746/// \param OpLoc The location of the operator itself (e.g., '+'). 6747/// 6748/// \param OpcIn The BinaryOperator::Opcode that describes this 6749/// operator. 6750/// 6751/// \param Functions The set of non-member functions that will be 6752/// considered by overload resolution. The caller needs to build this 6753/// set based on the context using, e.g., 6754/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 6755/// set should not contain any member functions; those will be added 6756/// by CreateOverloadedBinOp(). 6757/// 6758/// \param LHS Left-hand argument. 6759/// \param RHS Right-hand argument. 6760Sema::OwningExprResult 6761Sema::CreateOverloadedBinOp(SourceLocation OpLoc, 6762 unsigned OpcIn, 6763 const UnresolvedSetImpl &Fns, 6764 Expr *LHS, Expr *RHS) { 6765 Expr *Args[2] = { LHS, RHS }; 6766 LHS=RHS=0; //Please use only Args instead of LHS/RHS couple 6767 6768 BinaryOperator::Opcode Opc = static_cast<BinaryOperator::Opcode>(OpcIn); 6769 OverloadedOperatorKind Op = BinaryOperator::getOverloadedOperator(Opc); 6770 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 6771 6772 // If either side is type-dependent, create an appropriate dependent 6773 // expression. 6774 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 6775 if (Fns.empty()) { 6776 // If there are no functions to store, just build a dependent 6777 // BinaryOperator or CompoundAssignment. 6778 if (Opc <= BinaryOperator::Assign || Opc > BinaryOperator::OrAssign) 6779 return Owned(new (Context) BinaryOperator(Args[0], Args[1], Opc, 6780 Context.DependentTy, OpLoc)); 6781 6782 return Owned(new (Context) CompoundAssignOperator(Args[0], Args[1], Opc, 6783 Context.DependentTy, 6784 Context.DependentTy, 6785 Context.DependentTy, 6786 OpLoc)); 6787 } 6788 6789 // FIXME: save results of ADL from here? 6790 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 6791 UnresolvedLookupExpr *Fn 6792 = UnresolvedLookupExpr::Create(Context, /*Dependent*/ true, NamingClass, 6793 0, SourceRange(), OpName, OpLoc, 6794 /*ADL*/ true, IsOverloaded(Fns), 6795 Fns.begin(), Fns.end()); 6796 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 6797 Args, 2, 6798 Context.DependentTy, 6799 OpLoc)); 6800 } 6801 6802 // If this is the .* operator, which is not overloadable, just 6803 // create a built-in binary operator. 6804 if (Opc == BinaryOperator::PtrMemD) 6805 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 6806 6807 // If this is the assignment operator, we only perform overload resolution 6808 // if the left-hand side is a class or enumeration type. This is actually 6809 // a hack. The standard requires that we do overload resolution between the 6810 // various built-in candidates, but as DR507 points out, this can lead to 6811 // problems. So we do it this way, which pretty much follows what GCC does. 6812 // Note that we go the traditional code path for compound assignment forms. 6813 if (Opc==BinaryOperator::Assign && !Args[0]->getType()->isOverloadableType()) 6814 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 6815 6816 // Build an empty overload set. 6817 OverloadCandidateSet CandidateSet(OpLoc); 6818 6819 // Add the candidates from the given function set. 6820 AddFunctionCandidates(Fns, Args, 2, CandidateSet, false); 6821 6822 // Add operator candidates that are member functions. 6823 AddMemberOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 6824 6825 // Add candidates from ADL. 6826 AddArgumentDependentLookupCandidates(OpName, /*Operator*/ true, 6827 Args, 2, 6828 /*ExplicitTemplateArgs*/ 0, 6829 CandidateSet); 6830 6831 // Add builtin operator candidates. 6832 AddBuiltinOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 6833 6834 // Perform overload resolution. 6835 OverloadCandidateSet::iterator Best; 6836 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 6837 case OR_Success: { 6838 // We found a built-in operator or an overloaded operator. 6839 FunctionDecl *FnDecl = Best->Function; 6840 6841 if (FnDecl) { 6842 // We matched an overloaded operator. Build a call to that 6843 // operator. 6844 6845 // Convert the arguments. 6846 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 6847 // Best->Access is only meaningful for class members. 6848 CheckMemberOperatorAccess(OpLoc, Args[0], Args[1], Best->FoundDecl); 6849 6850 OwningExprResult Arg1 6851 = PerformCopyInitialization( 6852 InitializedEntity::InitializeParameter( 6853 FnDecl->getParamDecl(0)), 6854 SourceLocation(), 6855 Owned(Args[1])); 6856 if (Arg1.isInvalid()) 6857 return ExprError(); 6858 6859 if (PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/0, 6860 Best->FoundDecl, Method)) 6861 return ExprError(); 6862 6863 Args[1] = RHS = Arg1.takeAs<Expr>(); 6864 } else { 6865 // Convert the arguments. 6866 OwningExprResult Arg0 6867 = PerformCopyInitialization( 6868 InitializedEntity::InitializeParameter( 6869 FnDecl->getParamDecl(0)), 6870 SourceLocation(), 6871 Owned(Args[0])); 6872 if (Arg0.isInvalid()) 6873 return ExprError(); 6874 6875 OwningExprResult Arg1 6876 = PerformCopyInitialization( 6877 InitializedEntity::InitializeParameter( 6878 FnDecl->getParamDecl(1)), 6879 SourceLocation(), 6880 Owned(Args[1])); 6881 if (Arg1.isInvalid()) 6882 return ExprError(); 6883 Args[0] = LHS = Arg0.takeAs<Expr>(); 6884 Args[1] = RHS = Arg1.takeAs<Expr>(); 6885 } 6886 6887 DiagnoseUseOfDecl(Best->FoundDecl, OpLoc); 6888 6889 // Determine the result type 6890 QualType ResultTy 6891 = FnDecl->getType()->getAs<FunctionType>() 6892 ->getCallResultType(Context); 6893 6894 // Build the actual expression node. 6895 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 6896 OpLoc); 6897 UsualUnaryConversions(FnExpr); 6898 6899 ExprOwningPtr<CXXOperatorCallExpr> 6900 TheCall(this, new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 6901 Args, 2, ResultTy, 6902 OpLoc)); 6903 6904 if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall.get(), 6905 FnDecl)) 6906 return ExprError(); 6907 6908 return MaybeBindToTemporary(TheCall.release()); 6909 } else { 6910 // We matched a built-in operator. Convert the arguments, then 6911 // break out so that we will build the appropriate built-in 6912 // operator node. 6913 if (PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 6914 Best->Conversions[0], AA_Passing) || 6915 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 6916 Best->Conversions[1], AA_Passing)) 6917 return ExprError(); 6918 6919 break; 6920 } 6921 } 6922 6923 case OR_No_Viable_Function: { 6924 // C++ [over.match.oper]p9: 6925 // If the operator is the operator , [...] and there are no 6926 // viable functions, then the operator is assumed to be the 6927 // built-in operator and interpreted according to clause 5. 6928 if (Opc == BinaryOperator::Comma) 6929 break; 6930 6931 // For class as left operand for assignment or compound assigment operator 6932 // do not fall through to handling in built-in, but report that no overloaded 6933 // assignment operator found 6934 OwningExprResult Result = ExprError(); 6935 if (Args[0]->getType()->isRecordType() && 6936 Opc >= BinaryOperator::Assign && Opc <= BinaryOperator::OrAssign) { 6937 Diag(OpLoc, diag::err_ovl_no_viable_oper) 6938 << BinaryOperator::getOpcodeStr(Opc) 6939 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 6940 } else { 6941 // No viable function; try to create a built-in operation, which will 6942 // produce an error. Then, show the non-viable candidates. 6943 Result = CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 6944 } 6945 assert(Result.isInvalid() && 6946 "C++ binary operator overloading is missing candidates!"); 6947 if (Result.isInvalid()) 6948 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2, 6949 BinaryOperator::getOpcodeStr(Opc), OpLoc); 6950 return move(Result); 6951 } 6952 6953 case OR_Ambiguous: 6954 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 6955 << BinaryOperator::getOpcodeStr(Opc) 6956 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 6957 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, 2, 6958 BinaryOperator::getOpcodeStr(Opc), OpLoc); 6959 return ExprError(); 6960 6961 case OR_Deleted: 6962 Diag(OpLoc, diag::err_ovl_deleted_oper) 6963 << Best->Function->isDeleted() 6964 << BinaryOperator::getOpcodeStr(Opc) 6965 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 6966 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2); 6967 return ExprError(); 6968 } 6969 6970 // We matched a built-in operator; build it. 6971 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 6972} 6973 6974Action::OwningExprResult 6975Sema::CreateOverloadedArraySubscriptExpr(SourceLocation LLoc, 6976 SourceLocation RLoc, 6977 ExprArg Base, ExprArg Idx) { 6978 Expr *Args[2] = { static_cast<Expr*>(Base.get()), 6979 static_cast<Expr*>(Idx.get()) }; 6980 DeclarationName OpName = 6981 Context.DeclarationNames.getCXXOperatorName(OO_Subscript); 6982 6983 // If either side is type-dependent, create an appropriate dependent 6984 // expression. 6985 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 6986 6987 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 6988 UnresolvedLookupExpr *Fn 6989 = UnresolvedLookupExpr::Create(Context, /*Dependent*/ true, NamingClass, 6990 0, SourceRange(), OpName, LLoc, 6991 /*ADL*/ true, /*Overloaded*/ false, 6992 UnresolvedSetIterator(), 6993 UnresolvedSetIterator()); 6994 // Can't add any actual overloads yet 6995 6996 Base.release(); 6997 Idx.release(); 6998 return Owned(new (Context) CXXOperatorCallExpr(Context, OO_Subscript, Fn, 6999 Args, 2, 7000 Context.DependentTy, 7001 RLoc)); 7002 } 7003 7004 // Build an empty overload set. 7005 OverloadCandidateSet CandidateSet(LLoc); 7006 7007 // Subscript can only be overloaded as a member function. 7008 7009 // Add operator candidates that are member functions. 7010 AddMemberOperatorCandidates(OO_Subscript, LLoc, Args, 2, CandidateSet); 7011 7012 // Add builtin operator candidates. 7013 AddBuiltinOperatorCandidates(OO_Subscript, LLoc, Args, 2, CandidateSet); 7014 7015 // Perform overload resolution. 7016 OverloadCandidateSet::iterator Best; 7017 switch (BestViableFunction(CandidateSet, LLoc, Best)) { 7018 case OR_Success: { 7019 // We found a built-in operator or an overloaded operator. 7020 FunctionDecl *FnDecl = Best->Function; 7021 7022 if (FnDecl) { 7023 // We matched an overloaded operator. Build a call to that 7024 // operator. 7025 7026 CheckMemberOperatorAccess(LLoc, Args[0], Args[1], Best->FoundDecl); 7027 DiagnoseUseOfDecl(Best->FoundDecl, LLoc); 7028 7029 // Convert the arguments. 7030 CXXMethodDecl *Method = cast<CXXMethodDecl>(FnDecl); 7031 if (PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/0, 7032 Best->FoundDecl, Method)) 7033 return ExprError(); 7034 7035 // Convert the arguments. 7036 OwningExprResult InputInit 7037 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 7038 FnDecl->getParamDecl(0)), 7039 SourceLocation(), 7040 Owned(Args[1])); 7041 if (InputInit.isInvalid()) 7042 return ExprError(); 7043 7044 Args[1] = InputInit.takeAs<Expr>(); 7045 7046 // Determine the result type 7047 QualType ResultTy 7048 = FnDecl->getType()->getAs<FunctionType>() 7049 ->getCallResultType(Context); 7050 7051 // Build the actual expression node. 7052 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 7053 LLoc); 7054 UsualUnaryConversions(FnExpr); 7055 7056 Base.release(); 7057 Idx.release(); 7058 ExprOwningPtr<CXXOperatorCallExpr> 7059 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Subscript, 7060 FnExpr, Args, 2, 7061 ResultTy, RLoc)); 7062 7063 if (CheckCallReturnType(FnDecl->getResultType(), LLoc, TheCall.get(), 7064 FnDecl)) 7065 return ExprError(); 7066 7067 return MaybeBindToTemporary(TheCall.release()); 7068 } else { 7069 // We matched a built-in operator. Convert the arguments, then 7070 // break out so that we will build the appropriate built-in 7071 // operator node. 7072 if (PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 7073 Best->Conversions[0], AA_Passing) || 7074 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 7075 Best->Conversions[1], AA_Passing)) 7076 return ExprError(); 7077 7078 break; 7079 } 7080 } 7081 7082 case OR_No_Viable_Function: { 7083 if (CandidateSet.empty()) 7084 Diag(LLoc, diag::err_ovl_no_oper) 7085 << Args[0]->getType() << /*subscript*/ 0 7086 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 7087 else 7088 Diag(LLoc, diag::err_ovl_no_viable_subscript) 7089 << Args[0]->getType() 7090 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 7091 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2, 7092 "[]", LLoc); 7093 return ExprError(); 7094 } 7095 7096 case OR_Ambiguous: 7097 Diag(LLoc, diag::err_ovl_ambiguous_oper) 7098 << "[]" << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 7099 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, 2, 7100 "[]", LLoc); 7101 return ExprError(); 7102 7103 case OR_Deleted: 7104 Diag(LLoc, diag::err_ovl_deleted_oper) 7105 << Best->Function->isDeleted() << "[]" 7106 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 7107 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2, 7108 "[]", LLoc); 7109 return ExprError(); 7110 } 7111 7112 // We matched a built-in operator; build it. 7113 Base.release(); 7114 Idx.release(); 7115 return CreateBuiltinArraySubscriptExpr(Owned(Args[0]), LLoc, 7116 Owned(Args[1]), RLoc); 7117} 7118 7119/// BuildCallToMemberFunction - Build a call to a member 7120/// function. MemExpr is the expression that refers to the member 7121/// function (and includes the object parameter), Args/NumArgs are the 7122/// arguments to the function call (not including the object 7123/// parameter). The caller needs to validate that the member 7124/// expression refers to a member function or an overloaded member 7125/// function. 7126Sema::OwningExprResult 7127Sema::BuildCallToMemberFunction(Scope *S, Expr *MemExprE, 7128 SourceLocation LParenLoc, Expr **Args, 7129 unsigned NumArgs, SourceLocation *CommaLocs, 7130 SourceLocation RParenLoc) { 7131 // Dig out the member expression. This holds both the object 7132 // argument and the member function we're referring to. 7133 Expr *NakedMemExpr = MemExprE->IgnoreParens(); 7134 7135 MemberExpr *MemExpr; 7136 CXXMethodDecl *Method = 0; 7137 DeclAccessPair FoundDecl = DeclAccessPair::make(0, AS_public); 7138 NestedNameSpecifier *Qualifier = 0; 7139 if (isa<MemberExpr>(NakedMemExpr)) { 7140 MemExpr = cast<MemberExpr>(NakedMemExpr); 7141 Method = cast<CXXMethodDecl>(MemExpr->getMemberDecl()); 7142 FoundDecl = MemExpr->getFoundDecl(); 7143 Qualifier = MemExpr->getQualifier(); 7144 } else { 7145 UnresolvedMemberExpr *UnresExpr = cast<UnresolvedMemberExpr>(NakedMemExpr); 7146 Qualifier = UnresExpr->getQualifier(); 7147 7148 QualType ObjectType = UnresExpr->getBaseType(); 7149 7150 // Add overload candidates 7151 OverloadCandidateSet CandidateSet(UnresExpr->getMemberLoc()); 7152 7153 // FIXME: avoid copy. 7154 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 7155 if (UnresExpr->hasExplicitTemplateArgs()) { 7156 UnresExpr->copyTemplateArgumentsInto(TemplateArgsBuffer); 7157 TemplateArgs = &TemplateArgsBuffer; 7158 } 7159 7160 for (UnresolvedMemberExpr::decls_iterator I = UnresExpr->decls_begin(), 7161 E = UnresExpr->decls_end(); I != E; ++I) { 7162 7163 NamedDecl *Func = *I; 7164 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(Func->getDeclContext()); 7165 if (isa<UsingShadowDecl>(Func)) 7166 Func = cast<UsingShadowDecl>(Func)->getTargetDecl(); 7167 7168 if ((Method = dyn_cast<CXXMethodDecl>(Func))) { 7169 // If explicit template arguments were provided, we can't call a 7170 // non-template member function. 7171 if (TemplateArgs) 7172 continue; 7173 7174 AddMethodCandidate(Method, I.getPair(), ActingDC, ObjectType, 7175 Args, NumArgs, 7176 CandidateSet, /*SuppressUserConversions=*/false); 7177 } else { 7178 AddMethodTemplateCandidate(cast<FunctionTemplateDecl>(Func), 7179 I.getPair(), ActingDC, TemplateArgs, 7180 ObjectType, Args, NumArgs, 7181 CandidateSet, 7182 /*SuppressUsedConversions=*/false); 7183 } 7184 } 7185 7186 DeclarationName DeclName = UnresExpr->getMemberName(); 7187 7188 OverloadCandidateSet::iterator Best; 7189 switch (BestViableFunction(CandidateSet, UnresExpr->getLocStart(), Best)) { 7190 case OR_Success: 7191 Method = cast<CXXMethodDecl>(Best->Function); 7192 FoundDecl = Best->FoundDecl; 7193 CheckUnresolvedMemberAccess(UnresExpr, Best->FoundDecl); 7194 DiagnoseUseOfDecl(Best->FoundDecl, UnresExpr->getNameLoc()); 7195 break; 7196 7197 case OR_No_Viable_Function: 7198 Diag(UnresExpr->getMemberLoc(), 7199 diag::err_ovl_no_viable_member_function_in_call) 7200 << DeclName << MemExprE->getSourceRange(); 7201 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 7202 // FIXME: Leaking incoming expressions! 7203 return ExprError(); 7204 7205 case OR_Ambiguous: 7206 Diag(UnresExpr->getMemberLoc(), diag::err_ovl_ambiguous_member_call) 7207 << DeclName << MemExprE->getSourceRange(); 7208 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 7209 // FIXME: Leaking incoming expressions! 7210 return ExprError(); 7211 7212 case OR_Deleted: 7213 Diag(UnresExpr->getMemberLoc(), diag::err_ovl_deleted_member_call) 7214 << Best->Function->isDeleted() 7215 << DeclName << MemExprE->getSourceRange(); 7216 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 7217 // FIXME: Leaking incoming expressions! 7218 return ExprError(); 7219 } 7220 7221 MemExprE = FixOverloadedFunctionReference(MemExprE, FoundDecl, Method); 7222 7223 // If overload resolution picked a static member, build a 7224 // non-member call based on that function. 7225 if (Method->isStatic()) { 7226 return BuildResolvedCallExpr(MemExprE, Method, LParenLoc, 7227 Args, NumArgs, RParenLoc); 7228 } 7229 7230 MemExpr = cast<MemberExpr>(MemExprE->IgnoreParens()); 7231 } 7232 7233 assert(Method && "Member call to something that isn't a method?"); 7234 ExprOwningPtr<CXXMemberCallExpr> 7235 TheCall(this, new (Context) CXXMemberCallExpr(Context, MemExprE, Args, 7236 NumArgs, 7237 Method->getCallResultType(), 7238 RParenLoc)); 7239 7240 // Check for a valid return type. 7241 if (CheckCallReturnType(Method->getResultType(), MemExpr->getMemberLoc(), 7242 TheCall.get(), Method)) 7243 return ExprError(); 7244 7245 // Convert the object argument (for a non-static member function call). 7246 // We only need to do this if there was actually an overload; otherwise 7247 // it was done at lookup. 7248 Expr *ObjectArg = MemExpr->getBase(); 7249 if (!Method->isStatic() && 7250 PerformObjectArgumentInitialization(ObjectArg, Qualifier, 7251 FoundDecl, Method)) 7252 return ExprError(); 7253 MemExpr->setBase(ObjectArg); 7254 7255 // Convert the rest of the arguments 7256 const FunctionProtoType *Proto = Method->getType()->getAs<FunctionProtoType>(); 7257 if (ConvertArgumentsForCall(&*TheCall, MemExpr, Method, Proto, Args, NumArgs, 7258 RParenLoc)) 7259 return ExprError(); 7260 7261 if (CheckFunctionCall(Method, TheCall.get())) 7262 return ExprError(); 7263 7264 return MaybeBindToTemporary(TheCall.release()); 7265} 7266 7267/// BuildCallToObjectOfClassType - Build a call to an object of class 7268/// type (C++ [over.call.object]), which can end up invoking an 7269/// overloaded function call operator (@c operator()) or performing a 7270/// user-defined conversion on the object argument. 7271Sema::ExprResult 7272Sema::BuildCallToObjectOfClassType(Scope *S, Expr *Object, 7273 SourceLocation LParenLoc, 7274 Expr **Args, unsigned NumArgs, 7275 SourceLocation *CommaLocs, 7276 SourceLocation RParenLoc) { 7277 assert(Object->getType()->isRecordType() && "Requires object type argument"); 7278 const RecordType *Record = Object->getType()->getAs<RecordType>(); 7279 7280 // C++ [over.call.object]p1: 7281 // If the primary-expression E in the function call syntax 7282 // evaluates to a class object of type "cv T", then the set of 7283 // candidate functions includes at least the function call 7284 // operators of T. The function call operators of T are obtained by 7285 // ordinary lookup of the name operator() in the context of 7286 // (E).operator(). 7287 OverloadCandidateSet CandidateSet(LParenLoc); 7288 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Call); 7289 7290 if (RequireCompleteType(LParenLoc, Object->getType(), 7291 PDiag(diag::err_incomplete_object_call) 7292 << Object->getSourceRange())) 7293 return true; 7294 7295 LookupResult R(*this, OpName, LParenLoc, LookupOrdinaryName); 7296 LookupQualifiedName(R, Record->getDecl()); 7297 R.suppressDiagnostics(); 7298 7299 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 7300 Oper != OperEnd; ++Oper) { 7301 AddMethodCandidate(Oper.getPair(), Object->getType(), 7302 Args, NumArgs, CandidateSet, 7303 /*SuppressUserConversions=*/ false); 7304 } 7305 7306 // C++ [over.call.object]p2: 7307 // In addition, for each conversion function declared in T of the 7308 // form 7309 // 7310 // operator conversion-type-id () cv-qualifier; 7311 // 7312 // where cv-qualifier is the same cv-qualification as, or a 7313 // greater cv-qualification than, cv, and where conversion-type-id 7314 // denotes the type "pointer to function of (P1,...,Pn) returning 7315 // R", or the type "reference to pointer to function of 7316 // (P1,...,Pn) returning R", or the type "reference to function 7317 // of (P1,...,Pn) returning R", a surrogate call function [...] 7318 // is also considered as a candidate function. Similarly, 7319 // surrogate call functions are added to the set of candidate 7320 // functions for each conversion function declared in an 7321 // accessible base class provided the function is not hidden 7322 // within T by another intervening declaration. 7323 const UnresolvedSetImpl *Conversions 7324 = cast<CXXRecordDecl>(Record->getDecl())->getVisibleConversionFunctions(); 7325 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 7326 E = Conversions->end(); I != E; ++I) { 7327 NamedDecl *D = *I; 7328 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext()); 7329 if (isa<UsingShadowDecl>(D)) 7330 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 7331 7332 // Skip over templated conversion functions; they aren't 7333 // surrogates. 7334 if (isa<FunctionTemplateDecl>(D)) 7335 continue; 7336 7337 CXXConversionDecl *Conv = cast<CXXConversionDecl>(D); 7338 7339 // Strip the reference type (if any) and then the pointer type (if 7340 // any) to get down to what might be a function type. 7341 QualType ConvType = Conv->getConversionType().getNonReferenceType(); 7342 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 7343 ConvType = ConvPtrType->getPointeeType(); 7344 7345 if (const FunctionProtoType *Proto = ConvType->getAs<FunctionProtoType>()) 7346 AddSurrogateCandidate(Conv, I.getPair(), ActingContext, Proto, 7347 Object->getType(), Args, NumArgs, 7348 CandidateSet); 7349 } 7350 7351 // Perform overload resolution. 7352 OverloadCandidateSet::iterator Best; 7353 switch (BestViableFunction(CandidateSet, Object->getLocStart(), Best)) { 7354 case OR_Success: 7355 // Overload resolution succeeded; we'll build the appropriate call 7356 // below. 7357 break; 7358 7359 case OR_No_Viable_Function: 7360 if (CandidateSet.empty()) 7361 Diag(Object->getSourceRange().getBegin(), diag::err_ovl_no_oper) 7362 << Object->getType() << /*call*/ 1 7363 << Object->getSourceRange(); 7364 else 7365 Diag(Object->getSourceRange().getBegin(), 7366 diag::err_ovl_no_viable_object_call) 7367 << Object->getType() << Object->getSourceRange(); 7368 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 7369 break; 7370 7371 case OR_Ambiguous: 7372 Diag(Object->getSourceRange().getBegin(), 7373 diag::err_ovl_ambiguous_object_call) 7374 << Object->getType() << Object->getSourceRange(); 7375 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, NumArgs); 7376 break; 7377 7378 case OR_Deleted: 7379 Diag(Object->getSourceRange().getBegin(), 7380 diag::err_ovl_deleted_object_call) 7381 << Best->Function->isDeleted() 7382 << Object->getType() << Object->getSourceRange(); 7383 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 7384 break; 7385 } 7386 7387 if (Best == CandidateSet.end()) 7388 return true; 7389 7390 if (Best->Function == 0) { 7391 // Since there is no function declaration, this is one of the 7392 // surrogate candidates. Dig out the conversion function. 7393 CXXConversionDecl *Conv 7394 = cast<CXXConversionDecl>( 7395 Best->Conversions[0].UserDefined.ConversionFunction); 7396 7397 CheckMemberOperatorAccess(LParenLoc, Object, 0, Best->FoundDecl); 7398 DiagnoseUseOfDecl(Best->FoundDecl, LParenLoc); 7399 7400 // We selected one of the surrogate functions that converts the 7401 // object parameter to a function pointer. Perform the conversion 7402 // on the object argument, then let ActOnCallExpr finish the job. 7403 7404 // Create an implicit member expr to refer to the conversion operator. 7405 // and then call it. 7406 CXXMemberCallExpr *CE = BuildCXXMemberCallExpr(Object, Best->FoundDecl, 7407 Conv); 7408 7409 return ActOnCallExpr(S, ExprArg(*this, CE), LParenLoc, 7410 MultiExprArg(*this, (ExprTy**)Args, NumArgs), 7411 CommaLocs, RParenLoc).result(); 7412 } 7413 7414 CheckMemberOperatorAccess(LParenLoc, Object, 0, Best->FoundDecl); 7415 DiagnoseUseOfDecl(Best->FoundDecl, LParenLoc); 7416 7417 // We found an overloaded operator(). Build a CXXOperatorCallExpr 7418 // that calls this method, using Object for the implicit object 7419 // parameter and passing along the remaining arguments. 7420 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 7421 const FunctionProtoType *Proto = Method->getType()->getAs<FunctionProtoType>(); 7422 7423 unsigned NumArgsInProto = Proto->getNumArgs(); 7424 unsigned NumArgsToCheck = NumArgs; 7425 7426 // Build the full argument list for the method call (the 7427 // implicit object parameter is placed at the beginning of the 7428 // list). 7429 Expr **MethodArgs; 7430 if (NumArgs < NumArgsInProto) { 7431 NumArgsToCheck = NumArgsInProto; 7432 MethodArgs = new Expr*[NumArgsInProto + 1]; 7433 } else { 7434 MethodArgs = new Expr*[NumArgs + 1]; 7435 } 7436 MethodArgs[0] = Object; 7437 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 7438 MethodArgs[ArgIdx + 1] = Args[ArgIdx]; 7439 7440 Expr *NewFn = new (Context) DeclRefExpr(Method, Method->getType(), 7441 SourceLocation()); 7442 UsualUnaryConversions(NewFn); 7443 7444 // Once we've built TheCall, all of the expressions are properly 7445 // owned. 7446 QualType ResultTy = Method->getCallResultType(); 7447 ExprOwningPtr<CXXOperatorCallExpr> 7448 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Call, NewFn, 7449 MethodArgs, NumArgs + 1, 7450 ResultTy, RParenLoc)); 7451 delete [] MethodArgs; 7452 7453 if (CheckCallReturnType(Method->getResultType(), LParenLoc, TheCall.get(), 7454 Method)) 7455 return true; 7456 7457 // We may have default arguments. If so, we need to allocate more 7458 // slots in the call for them. 7459 if (NumArgs < NumArgsInProto) 7460 TheCall->setNumArgs(Context, NumArgsInProto + 1); 7461 else if (NumArgs > NumArgsInProto) 7462 NumArgsToCheck = NumArgsInProto; 7463 7464 bool IsError = false; 7465 7466 // Initialize the implicit object parameter. 7467 IsError |= PerformObjectArgumentInitialization(Object, /*Qualifier=*/0, 7468 Best->FoundDecl, Method); 7469 TheCall->setArg(0, Object); 7470 7471 7472 // Check the argument types. 7473 for (unsigned i = 0; i != NumArgsToCheck; i++) { 7474 Expr *Arg; 7475 if (i < NumArgs) { 7476 Arg = Args[i]; 7477 7478 // Pass the argument. 7479 7480 OwningExprResult InputInit 7481 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 7482 Method->getParamDecl(i)), 7483 SourceLocation(), Owned(Arg)); 7484 7485 IsError |= InputInit.isInvalid(); 7486 Arg = InputInit.takeAs<Expr>(); 7487 } else { 7488 OwningExprResult DefArg 7489 = BuildCXXDefaultArgExpr(LParenLoc, Method, Method->getParamDecl(i)); 7490 if (DefArg.isInvalid()) { 7491 IsError = true; 7492 break; 7493 } 7494 7495 Arg = DefArg.takeAs<Expr>(); 7496 } 7497 7498 TheCall->setArg(i + 1, Arg); 7499 } 7500 7501 // If this is a variadic call, handle args passed through "...". 7502 if (Proto->isVariadic()) { 7503 // Promote the arguments (C99 6.5.2.2p7). 7504 for (unsigned i = NumArgsInProto; i != NumArgs; i++) { 7505 Expr *Arg = Args[i]; 7506 IsError |= DefaultVariadicArgumentPromotion(Arg, VariadicMethod, 0); 7507 TheCall->setArg(i + 1, Arg); 7508 } 7509 } 7510 7511 if (IsError) return true; 7512 7513 if (CheckFunctionCall(Method, TheCall.get())) 7514 return true; 7515 7516 return MaybeBindToTemporary(TheCall.release()).result(); 7517} 7518 7519/// BuildOverloadedArrowExpr - Build a call to an overloaded @c operator-> 7520/// (if one exists), where @c Base is an expression of class type and 7521/// @c Member is the name of the member we're trying to find. 7522Sema::OwningExprResult 7523Sema::BuildOverloadedArrowExpr(Scope *S, ExprArg BaseIn, SourceLocation OpLoc) { 7524 Expr *Base = static_cast<Expr *>(BaseIn.get()); 7525 assert(Base->getType()->isRecordType() && "left-hand side must have class type"); 7526 7527 SourceLocation Loc = Base->getExprLoc(); 7528 7529 // C++ [over.ref]p1: 7530 // 7531 // [...] An expression x->m is interpreted as (x.operator->())->m 7532 // for a class object x of type T if T::operator->() exists and if 7533 // the operator is selected as the best match function by the 7534 // overload resolution mechanism (13.3). 7535 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Arrow); 7536 OverloadCandidateSet CandidateSet(Loc); 7537 const RecordType *BaseRecord = Base->getType()->getAs<RecordType>(); 7538 7539 if (RequireCompleteType(Loc, Base->getType(), 7540 PDiag(diag::err_typecheck_incomplete_tag) 7541 << Base->getSourceRange())) 7542 return ExprError(); 7543 7544 LookupResult R(*this, OpName, OpLoc, LookupOrdinaryName); 7545 LookupQualifiedName(R, BaseRecord->getDecl()); 7546 R.suppressDiagnostics(); 7547 7548 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 7549 Oper != OperEnd; ++Oper) { 7550 AddMethodCandidate(Oper.getPair(), Base->getType(), 0, 0, CandidateSet, 7551 /*SuppressUserConversions=*/false); 7552 } 7553 7554 // Perform overload resolution. 7555 OverloadCandidateSet::iterator Best; 7556 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 7557 case OR_Success: 7558 // Overload resolution succeeded; we'll build the call below. 7559 break; 7560 7561 case OR_No_Viable_Function: 7562 if (CandidateSet.empty()) 7563 Diag(OpLoc, diag::err_typecheck_member_reference_arrow) 7564 << Base->getType() << Base->getSourceRange(); 7565 else 7566 Diag(OpLoc, diag::err_ovl_no_viable_oper) 7567 << "operator->" << Base->getSourceRange(); 7568 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, &Base, 1); 7569 return ExprError(); 7570 7571 case OR_Ambiguous: 7572 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 7573 << "->" << Base->getSourceRange(); 7574 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, &Base, 1); 7575 return ExprError(); 7576 7577 case OR_Deleted: 7578 Diag(OpLoc, diag::err_ovl_deleted_oper) 7579 << Best->Function->isDeleted() 7580 << "->" << Base->getSourceRange(); 7581 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, &Base, 1); 7582 return ExprError(); 7583 } 7584 7585 CheckMemberOperatorAccess(OpLoc, Base, 0, Best->FoundDecl); 7586 DiagnoseUseOfDecl(Best->FoundDecl, OpLoc); 7587 7588 // Convert the object parameter. 7589 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 7590 if (PerformObjectArgumentInitialization(Base, /*Qualifier=*/0, 7591 Best->FoundDecl, Method)) 7592 return ExprError(); 7593 7594 // No concerns about early exits now. 7595 BaseIn.release(); 7596 7597 // Build the operator call. 7598 Expr *FnExpr = new (Context) DeclRefExpr(Method, Method->getType(), 7599 SourceLocation()); 7600 UsualUnaryConversions(FnExpr); 7601 7602 QualType ResultTy = Method->getCallResultType(); 7603 ExprOwningPtr<CXXOperatorCallExpr> 7604 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Arrow, FnExpr, 7605 &Base, 1, ResultTy, OpLoc)); 7606 7607 if (CheckCallReturnType(Method->getResultType(), OpLoc, TheCall.get(), 7608 Method)) 7609 return ExprError(); 7610 return move(TheCall); 7611} 7612 7613/// FixOverloadedFunctionReference - E is an expression that refers to 7614/// a C++ overloaded function (possibly with some parentheses and 7615/// perhaps a '&' around it). We have resolved the overloaded function 7616/// to the function declaration Fn, so patch up the expression E to 7617/// refer (possibly indirectly) to Fn. Returns the new expr. 7618Expr *Sema::FixOverloadedFunctionReference(Expr *E, DeclAccessPair Found, 7619 FunctionDecl *Fn) { 7620 if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) { 7621 Expr *SubExpr = FixOverloadedFunctionReference(PE->getSubExpr(), 7622 Found, Fn); 7623 if (SubExpr == PE->getSubExpr()) 7624 return PE->Retain(); 7625 7626 return new (Context) ParenExpr(PE->getLParen(), PE->getRParen(), SubExpr); 7627 } 7628 7629 if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) { 7630 Expr *SubExpr = FixOverloadedFunctionReference(ICE->getSubExpr(), 7631 Found, Fn); 7632 assert(Context.hasSameType(ICE->getSubExpr()->getType(), 7633 SubExpr->getType()) && 7634 "Implicit cast type cannot be determined from overload"); 7635 if (SubExpr == ICE->getSubExpr()) 7636 return ICE->Retain(); 7637 7638 return new (Context) ImplicitCastExpr(ICE->getType(), 7639 ICE->getCastKind(), 7640 SubExpr, CXXBaseSpecifierArray(), 7641 ICE->getCategory()); 7642 } 7643 7644 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(E)) { 7645 assert(UnOp->getOpcode() == UnaryOperator::AddrOf && 7646 "Can only take the address of an overloaded function"); 7647 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 7648 if (Method->isStatic()) { 7649 // Do nothing: static member functions aren't any different 7650 // from non-member functions. 7651 } else { 7652 // Fix the sub expression, which really has to be an 7653 // UnresolvedLookupExpr holding an overloaded member function 7654 // or template. 7655 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(), 7656 Found, Fn); 7657 if (SubExpr == UnOp->getSubExpr()) 7658 return UnOp->Retain(); 7659 7660 assert(isa<DeclRefExpr>(SubExpr) 7661 && "fixed to something other than a decl ref"); 7662 assert(cast<DeclRefExpr>(SubExpr)->getQualifier() 7663 && "fixed to a member ref with no nested name qualifier"); 7664 7665 // We have taken the address of a pointer to member 7666 // function. Perform the computation here so that we get the 7667 // appropriate pointer to member type. 7668 QualType ClassType 7669 = Context.getTypeDeclType(cast<RecordDecl>(Method->getDeclContext())); 7670 QualType MemPtrType 7671 = Context.getMemberPointerType(Fn->getType(), ClassType.getTypePtr()); 7672 7673 return new (Context) UnaryOperator(SubExpr, UnaryOperator::AddrOf, 7674 MemPtrType, UnOp->getOperatorLoc()); 7675 } 7676 } 7677 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(), 7678 Found, Fn); 7679 if (SubExpr == UnOp->getSubExpr()) 7680 return UnOp->Retain(); 7681 7682 return new (Context) UnaryOperator(SubExpr, UnaryOperator::AddrOf, 7683 Context.getPointerType(SubExpr->getType()), 7684 UnOp->getOperatorLoc()); 7685 } 7686 7687 if (UnresolvedLookupExpr *ULE = dyn_cast<UnresolvedLookupExpr>(E)) { 7688 // FIXME: avoid copy. 7689 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 7690 if (ULE->hasExplicitTemplateArgs()) { 7691 ULE->copyTemplateArgumentsInto(TemplateArgsBuffer); 7692 TemplateArgs = &TemplateArgsBuffer; 7693 } 7694 7695 return DeclRefExpr::Create(Context, 7696 ULE->getQualifier(), 7697 ULE->getQualifierRange(), 7698 Fn, 7699 ULE->getNameLoc(), 7700 Fn->getType(), 7701 TemplateArgs); 7702 } 7703 7704 if (UnresolvedMemberExpr *MemExpr = dyn_cast<UnresolvedMemberExpr>(E)) { 7705 // FIXME: avoid copy. 7706 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 7707 if (MemExpr->hasExplicitTemplateArgs()) { 7708 MemExpr->copyTemplateArgumentsInto(TemplateArgsBuffer); 7709 TemplateArgs = &TemplateArgsBuffer; 7710 } 7711 7712 Expr *Base; 7713 7714 // If we're filling in 7715 if (MemExpr->isImplicitAccess()) { 7716 if (cast<CXXMethodDecl>(Fn)->isStatic()) { 7717 return DeclRefExpr::Create(Context, 7718 MemExpr->getQualifier(), 7719 MemExpr->getQualifierRange(), 7720 Fn, 7721 MemExpr->getMemberLoc(), 7722 Fn->getType(), 7723 TemplateArgs); 7724 } else { 7725 SourceLocation Loc = MemExpr->getMemberLoc(); 7726 if (MemExpr->getQualifier()) 7727 Loc = MemExpr->getQualifierRange().getBegin(); 7728 Base = new (Context) CXXThisExpr(Loc, 7729 MemExpr->getBaseType(), 7730 /*isImplicit=*/true); 7731 } 7732 } else 7733 Base = MemExpr->getBase()->Retain(); 7734 7735 return MemberExpr::Create(Context, Base, 7736 MemExpr->isArrow(), 7737 MemExpr->getQualifier(), 7738 MemExpr->getQualifierRange(), 7739 Fn, 7740 Found, 7741 MemExpr->getMemberLoc(), 7742 TemplateArgs, 7743 Fn->getType()); 7744 } 7745 7746 assert(false && "Invalid reference to overloaded function"); 7747 return E->Retain(); 7748} 7749 7750Sema::OwningExprResult Sema::FixOverloadedFunctionReference(OwningExprResult E, 7751 DeclAccessPair Found, 7752 FunctionDecl *Fn) { 7753 return Owned(FixOverloadedFunctionReference((Expr *)E.get(), Found, Fn)); 7754} 7755 7756} // end namespace clang 7757