SemaOverload.cpp revision 7b49202090678f45fa0c0bb5fa560d8a27b0c604
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 // If both of the functions are extern "C", then they are not 577 // overloads. 578 if (Old->isExternC() && New->isExternC()) 579 return false; 580 581 FunctionTemplateDecl *OldTemplate = Old->getDescribedFunctionTemplate(); 582 FunctionTemplateDecl *NewTemplate = New->getDescribedFunctionTemplate(); 583 584 // C++ [temp.fct]p2: 585 // A function template can be overloaded with other function templates 586 // and with normal (non-template) functions. 587 if ((OldTemplate == 0) != (NewTemplate == 0)) 588 return true; 589 590 // Is the function New an overload of the function Old? 591 QualType OldQType = Context.getCanonicalType(Old->getType()); 592 QualType NewQType = Context.getCanonicalType(New->getType()); 593 594 // Compare the signatures (C++ 1.3.10) of the two functions to 595 // determine whether they are overloads. If we find any mismatch 596 // in the signature, they are overloads. 597 598 // If either of these functions is a K&R-style function (no 599 // prototype), then we consider them to have matching signatures. 600 if (isa<FunctionNoProtoType>(OldQType.getTypePtr()) || 601 isa<FunctionNoProtoType>(NewQType.getTypePtr())) 602 return false; 603 604 FunctionProtoType* OldType = cast<FunctionProtoType>(OldQType); 605 FunctionProtoType* NewType = cast<FunctionProtoType>(NewQType); 606 607 // The signature of a function includes the types of its 608 // parameters (C++ 1.3.10), which includes the presence or absence 609 // of the ellipsis; see C++ DR 357). 610 if (OldQType != NewQType && 611 (OldType->getNumArgs() != NewType->getNumArgs() || 612 OldType->isVariadic() != NewType->isVariadic() || 613 !FunctionArgTypesAreEqual(OldType, NewType))) 614 return true; 615 616 // C++ [temp.over.link]p4: 617 // The signature of a function template consists of its function 618 // signature, its return type and its template parameter list. The names 619 // of the template parameters are significant only for establishing the 620 // relationship between the template parameters and the rest of the 621 // signature. 622 // 623 // We check the return type and template parameter lists for function 624 // templates first; the remaining checks follow. 625 // 626 // However, we don't consider either of these when deciding whether 627 // a member introduced by a shadow declaration is hidden. 628 if (!UseUsingDeclRules && NewTemplate && 629 (!TemplateParameterListsAreEqual(NewTemplate->getTemplateParameters(), 630 OldTemplate->getTemplateParameters(), 631 false, TPL_TemplateMatch) || 632 OldType->getResultType() != NewType->getResultType())) 633 return true; 634 635 // If the function is a class member, its signature includes the 636 // cv-qualifiers (if any) on the function itself. 637 // 638 // As part of this, also check whether one of the member functions 639 // is static, in which case they are not overloads (C++ 640 // 13.1p2). While not part of the definition of the signature, 641 // this check is important to determine whether these functions 642 // can be overloaded. 643 CXXMethodDecl* OldMethod = dyn_cast<CXXMethodDecl>(Old); 644 CXXMethodDecl* NewMethod = dyn_cast<CXXMethodDecl>(New); 645 if (OldMethod && NewMethod && 646 !OldMethod->isStatic() && !NewMethod->isStatic() && 647 OldMethod->getTypeQualifiers() != NewMethod->getTypeQualifiers()) 648 return true; 649 650 // The signatures match; this is not an overload. 651 return false; 652} 653 654/// TryImplicitConversion - Attempt to perform an implicit conversion 655/// from the given expression (Expr) to the given type (ToType). This 656/// function returns an implicit conversion sequence that can be used 657/// to perform the initialization. Given 658/// 659/// void f(float f); 660/// void g(int i) { f(i); } 661/// 662/// this routine would produce an implicit conversion sequence to 663/// describe the initialization of f from i, which will be a standard 664/// conversion sequence containing an lvalue-to-rvalue conversion (C++ 665/// 4.1) followed by a floating-integral conversion (C++ 4.9). 666// 667/// Note that this routine only determines how the conversion can be 668/// performed; it does not actually perform the conversion. As such, 669/// it will not produce any diagnostics if no conversion is available, 670/// but will instead return an implicit conversion sequence of kind 671/// "BadConversion". 672/// 673/// If @p SuppressUserConversions, then user-defined conversions are 674/// not permitted. 675/// If @p AllowExplicit, then explicit user-defined conversions are 676/// permitted. 677ImplicitConversionSequence 678Sema::TryImplicitConversion(Expr* From, QualType ToType, 679 bool SuppressUserConversions, 680 bool AllowExplicit, 681 bool InOverloadResolution) { 682 ImplicitConversionSequence ICS; 683 if (IsStandardConversion(From, ToType, InOverloadResolution, ICS.Standard)) { 684 ICS.setStandard(); 685 return ICS; 686 } 687 688 if (!getLangOptions().CPlusPlus) { 689 ICS.setBad(BadConversionSequence::no_conversion, From, ToType); 690 return ICS; 691 } 692 693 // C++ [over.ics.user]p4: 694 // A conversion of an expression of class type to the same class 695 // type is given Exact Match rank, and a conversion of an 696 // expression of class type to a base class of that type is 697 // given Conversion rank, in spite of the fact that a copy/move 698 // constructor (i.e., a user-defined conversion function) is 699 // called for those cases. 700 QualType FromType = From->getType(); 701 if (ToType->getAs<RecordType>() && FromType->getAs<RecordType>() && 702 (Context.hasSameUnqualifiedType(FromType, ToType) || 703 IsDerivedFrom(FromType, ToType))) { 704 ICS.setStandard(); 705 ICS.Standard.setAsIdentityConversion(); 706 ICS.Standard.setFromType(FromType); 707 ICS.Standard.setAllToTypes(ToType); 708 709 // We don't actually check at this point whether there is a valid 710 // copy/move constructor, since overloading just assumes that it 711 // exists. When we actually perform initialization, we'll find the 712 // appropriate constructor to copy the returned object, if needed. 713 ICS.Standard.CopyConstructor = 0; 714 715 // Determine whether this is considered a derived-to-base conversion. 716 if (!Context.hasSameUnqualifiedType(FromType, ToType)) 717 ICS.Standard.Second = ICK_Derived_To_Base; 718 719 return ICS; 720 } 721 722 if (SuppressUserConversions) { 723 // We're not in the case above, so there is no conversion that 724 // we can perform. 725 ICS.setBad(BadConversionSequence::no_conversion, From, ToType); 726 return ICS; 727 } 728 729 // Attempt user-defined conversion. 730 OverloadCandidateSet Conversions(From->getExprLoc()); 731 OverloadingResult UserDefResult 732 = IsUserDefinedConversion(From, ToType, ICS.UserDefined, Conversions, 733 AllowExplicit); 734 735 if (UserDefResult == OR_Success) { 736 ICS.setUserDefined(); 737 // C++ [over.ics.user]p4: 738 // A conversion of an expression of class type to the same class 739 // type is given Exact Match rank, and a conversion of an 740 // expression of class type to a base class of that type is 741 // given Conversion rank, in spite of the fact that a copy 742 // constructor (i.e., a user-defined conversion function) is 743 // called for those cases. 744 if (CXXConstructorDecl *Constructor 745 = dyn_cast<CXXConstructorDecl>(ICS.UserDefined.ConversionFunction)) { 746 QualType FromCanon 747 = Context.getCanonicalType(From->getType().getUnqualifiedType()); 748 QualType ToCanon = Context.getCanonicalType(ToType).getUnqualifiedType(); 749 if (Constructor->isCopyConstructor() && 750 (FromCanon == ToCanon || IsDerivedFrom(FromCanon, ToCanon))) { 751 // Turn this into a "standard" conversion sequence, so that it 752 // gets ranked with standard conversion sequences. 753 ICS.setStandard(); 754 ICS.Standard.setAsIdentityConversion(); 755 ICS.Standard.setFromType(From->getType()); 756 ICS.Standard.setAllToTypes(ToType); 757 ICS.Standard.CopyConstructor = Constructor; 758 if (ToCanon != FromCanon) 759 ICS.Standard.Second = ICK_Derived_To_Base; 760 } 761 } 762 763 // C++ [over.best.ics]p4: 764 // However, when considering the argument of a user-defined 765 // conversion function that is a candidate by 13.3.1.3 when 766 // invoked for the copying of the temporary in the second step 767 // of a class copy-initialization, or by 13.3.1.4, 13.3.1.5, or 768 // 13.3.1.6 in all cases, only standard conversion sequences and 769 // ellipsis conversion sequences are allowed. 770 if (SuppressUserConversions && ICS.isUserDefined()) { 771 ICS.setBad(BadConversionSequence::suppressed_user, From, ToType); 772 } 773 } else if (UserDefResult == OR_Ambiguous && !SuppressUserConversions) { 774 ICS.setAmbiguous(); 775 ICS.Ambiguous.setFromType(From->getType()); 776 ICS.Ambiguous.setToType(ToType); 777 for (OverloadCandidateSet::iterator Cand = Conversions.begin(); 778 Cand != Conversions.end(); ++Cand) 779 if (Cand->Viable) 780 ICS.Ambiguous.addConversion(Cand->Function); 781 } else { 782 ICS.setBad(BadConversionSequence::no_conversion, From, ToType); 783 } 784 785 return ICS; 786} 787 788/// PerformImplicitConversion - Perform an implicit conversion of the 789/// expression From to the type ToType. Returns true if there was an 790/// error, false otherwise. The expression From is replaced with the 791/// converted expression. Flavor is the kind of conversion we're 792/// performing, used in the error message. If @p AllowExplicit, 793/// explicit user-defined conversions are permitted. 794bool 795Sema::PerformImplicitConversion(Expr *&From, QualType ToType, 796 AssignmentAction Action, bool AllowExplicit) { 797 ImplicitConversionSequence ICS; 798 return PerformImplicitConversion(From, ToType, Action, AllowExplicit, ICS); 799} 800 801bool 802Sema::PerformImplicitConversion(Expr *&From, QualType ToType, 803 AssignmentAction Action, bool AllowExplicit, 804 ImplicitConversionSequence& ICS) { 805 ICS = TryImplicitConversion(From, ToType, 806 /*SuppressUserConversions=*/false, 807 AllowExplicit, 808 /*InOverloadResolution=*/false); 809 return PerformImplicitConversion(From, ToType, ICS, Action); 810} 811 812/// \brief Determine whether the conversion from FromType to ToType is a valid 813/// conversion that strips "noreturn" off the nested function type. 814static bool IsNoReturnConversion(ASTContext &Context, QualType FromType, 815 QualType ToType, QualType &ResultTy) { 816 if (Context.hasSameUnqualifiedType(FromType, ToType)) 817 return false; 818 819 // Strip the noreturn off the type we're converting from; noreturn can 820 // safely be removed. 821 FromType = Context.getNoReturnType(FromType, false); 822 if (!Context.hasSameUnqualifiedType(FromType, ToType)) 823 return false; 824 825 ResultTy = FromType; 826 return true; 827} 828 829/// \brief Determine whether the conversion from FromType to ToType is a valid 830/// vector conversion. 831/// 832/// \param ICK Will be set to the vector conversion kind, if this is a vector 833/// conversion. 834static bool IsVectorConversion(ASTContext &Context, QualType FromType, 835 QualType ToType, ImplicitConversionKind &ICK) { 836 // We need at least one of these types to be a vector type to have a vector 837 // conversion. 838 if (!ToType->isVectorType() && !FromType->isVectorType()) 839 return false; 840 841 // Identical types require no conversions. 842 if (Context.hasSameUnqualifiedType(FromType, ToType)) 843 return false; 844 845 // There are no conversions between extended vector types, only identity. 846 if (ToType->isExtVectorType()) { 847 // There are no conversions between extended vector types other than the 848 // identity conversion. 849 if (FromType->isExtVectorType()) 850 return false; 851 852 // Vector splat from any arithmetic type to a vector. 853 if (FromType->isArithmeticType()) { 854 ICK = ICK_Vector_Splat; 855 return true; 856 } 857 } 858 859 // We can perform the conversion between vector types in the following cases: 860 // 1)vector types are equivalent AltiVec and GCC vector types 861 // 2)lax vector conversions are permitted and the vector types are of the 862 // same size 863 if (ToType->isVectorType() && FromType->isVectorType()) { 864 if (Context.areCompatibleVectorTypes(FromType, ToType) || 865 (Context.getLangOptions().LaxVectorConversions && 866 (Context.getTypeSize(FromType) == Context.getTypeSize(ToType)))) { 867 ICK = ICK_Vector_Conversion; 868 return true; 869 } 870 } 871 872 return false; 873} 874 875/// IsStandardConversion - Determines whether there is a standard 876/// conversion sequence (C++ [conv], C++ [over.ics.scs]) from the 877/// expression From to the type ToType. Standard conversion sequences 878/// only consider non-class types; for conversions that involve class 879/// types, use TryImplicitConversion. If a conversion exists, SCS will 880/// contain the standard conversion sequence required to perform this 881/// conversion and this routine will return true. Otherwise, this 882/// routine will return false and the value of SCS is unspecified. 883bool 884Sema::IsStandardConversion(Expr* From, QualType ToType, 885 bool InOverloadResolution, 886 StandardConversionSequence &SCS) { 887 QualType FromType = From->getType(); 888 889 // Standard conversions (C++ [conv]) 890 SCS.setAsIdentityConversion(); 891 SCS.DeprecatedStringLiteralToCharPtr = false; 892 SCS.IncompatibleObjC = false; 893 SCS.setFromType(FromType); 894 SCS.CopyConstructor = 0; 895 896 // There are no standard conversions for class types in C++, so 897 // abort early. When overloading in C, however, we do permit 898 if (FromType->isRecordType() || ToType->isRecordType()) { 899 if (getLangOptions().CPlusPlus) 900 return false; 901 902 // When we're overloading in C, we allow, as standard conversions, 903 } 904 905 // The first conversion can be an lvalue-to-rvalue conversion, 906 // array-to-pointer conversion, or function-to-pointer conversion 907 // (C++ 4p1). 908 909 if (FromType == Context.OverloadTy) { 910 DeclAccessPair AccessPair; 911 if (FunctionDecl *Fn 912 = ResolveAddressOfOverloadedFunction(From, ToType, false, 913 AccessPair)) { 914 // We were able to resolve the address of the overloaded function, 915 // so we can convert to the type of that function. 916 FromType = Fn->getType(); 917 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 918 if (!Method->isStatic()) { 919 Type *ClassType 920 = Context.getTypeDeclType(Method->getParent()).getTypePtr(); 921 FromType = Context.getMemberPointerType(FromType, ClassType); 922 } 923 } 924 925 // If the "from" expression takes the address of the overloaded 926 // function, update the type of the resulting expression accordingly. 927 if (FromType->getAs<FunctionType>()) 928 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(From->IgnoreParens())) 929 if (UnOp->getOpcode() == UnaryOperator::AddrOf) 930 FromType = Context.getPointerType(FromType); 931 932 // Check that we've computed the proper type after overload resolution. 933 assert(Context.hasSameType(FromType, 934 FixOverloadedFunctionReference(From, AccessPair, Fn)->getType())); 935 } else { 936 return false; 937 } 938 } 939 // Lvalue-to-rvalue conversion (C++ 4.1): 940 // An lvalue (3.10) of a non-function, non-array type T can be 941 // converted to an rvalue. 942 Expr::isLvalueResult argIsLvalue = From->isLvalue(Context); 943 if (argIsLvalue == Expr::LV_Valid && 944 !FromType->isFunctionType() && !FromType->isArrayType() && 945 Context.getCanonicalType(FromType) != Context.OverloadTy) { 946 SCS.First = ICK_Lvalue_To_Rvalue; 947 948 // If T is a non-class type, the type of the rvalue is the 949 // cv-unqualified version of T. Otherwise, the type of the rvalue 950 // is T (C++ 4.1p1). C++ can't get here with class types; in C, we 951 // just strip the qualifiers because they don't matter. 952 FromType = FromType.getUnqualifiedType(); 953 } else if (FromType->isArrayType()) { 954 // Array-to-pointer conversion (C++ 4.2) 955 SCS.First = ICK_Array_To_Pointer; 956 957 // An lvalue or rvalue of type "array of N T" or "array of unknown 958 // bound of T" can be converted to an rvalue of type "pointer to 959 // T" (C++ 4.2p1). 960 FromType = Context.getArrayDecayedType(FromType); 961 962 if (IsStringLiteralToNonConstPointerConversion(From, ToType)) { 963 // This conversion is deprecated. (C++ D.4). 964 SCS.DeprecatedStringLiteralToCharPtr = true; 965 966 // For the purpose of ranking in overload resolution 967 // (13.3.3.1.1), this conversion is considered an 968 // array-to-pointer conversion followed by a qualification 969 // conversion (4.4). (C++ 4.2p2) 970 SCS.Second = ICK_Identity; 971 SCS.Third = ICK_Qualification; 972 SCS.setAllToTypes(FromType); 973 return true; 974 } 975 } else if (FromType->isFunctionType() && argIsLvalue == Expr::LV_Valid) { 976 // Function-to-pointer conversion (C++ 4.3). 977 SCS.First = ICK_Function_To_Pointer; 978 979 // An lvalue of function type T can be converted to an rvalue of 980 // type "pointer to T." The result is a pointer to the 981 // function. (C++ 4.3p1). 982 FromType = Context.getPointerType(FromType); 983 } else { 984 // We don't require any conversions for the first step. 985 SCS.First = ICK_Identity; 986 } 987 SCS.setToType(0, FromType); 988 989 // The second conversion can be an integral promotion, floating 990 // point promotion, integral conversion, floating point conversion, 991 // floating-integral conversion, pointer conversion, 992 // pointer-to-member conversion, or boolean conversion (C++ 4p1). 993 // For overloading in C, this can also be a "compatible-type" 994 // conversion. 995 bool IncompatibleObjC = false; 996 ImplicitConversionKind SecondICK = ICK_Identity; 997 if (Context.hasSameUnqualifiedType(FromType, ToType)) { 998 // The unqualified versions of the types are the same: there's no 999 // conversion to do. 1000 SCS.Second = ICK_Identity; 1001 } else if (IsIntegralPromotion(From, FromType, ToType)) { 1002 // Integral promotion (C++ 4.5). 1003 SCS.Second = ICK_Integral_Promotion; 1004 FromType = ToType.getUnqualifiedType(); 1005 } else if (IsFloatingPointPromotion(FromType, ToType)) { 1006 // Floating point promotion (C++ 4.6). 1007 SCS.Second = ICK_Floating_Promotion; 1008 FromType = ToType.getUnqualifiedType(); 1009 } else if (IsComplexPromotion(FromType, ToType)) { 1010 // Complex promotion (Clang extension) 1011 SCS.Second = ICK_Complex_Promotion; 1012 FromType = ToType.getUnqualifiedType(); 1013 } else if (FromType->isIntegralOrEnumerationType() && 1014 ToType->isIntegralType(Context)) { 1015 // Integral conversions (C++ 4.7). 1016 SCS.Second = ICK_Integral_Conversion; 1017 FromType = ToType.getUnqualifiedType(); 1018 } else if (FromType->isComplexType() && ToType->isComplexType()) { 1019 // Complex conversions (C99 6.3.1.6) 1020 SCS.Second = ICK_Complex_Conversion; 1021 FromType = ToType.getUnqualifiedType(); 1022 } else if ((FromType->isComplexType() && ToType->isArithmeticType()) || 1023 (ToType->isComplexType() && FromType->isArithmeticType())) { 1024 // Complex-real conversions (C99 6.3.1.7) 1025 SCS.Second = ICK_Complex_Real; 1026 FromType = ToType.getUnqualifiedType(); 1027 } else if (FromType->isRealFloatingType() && ToType->isRealFloatingType()) { 1028 // Floating point conversions (C++ 4.8). 1029 SCS.Second = ICK_Floating_Conversion; 1030 FromType = ToType.getUnqualifiedType(); 1031 } else if ((FromType->isRealFloatingType() && 1032 ToType->isIntegralType(Context) && !ToType->isBooleanType()) || 1033 (FromType->isIntegralOrEnumerationType() && 1034 ToType->isRealFloatingType())) { 1035 // Floating-integral conversions (C++ 4.9). 1036 SCS.Second = ICK_Floating_Integral; 1037 FromType = ToType.getUnqualifiedType(); 1038 } else if (IsPointerConversion(From, FromType, ToType, InOverloadResolution, 1039 FromType, IncompatibleObjC)) { 1040 // Pointer conversions (C++ 4.10). 1041 SCS.Second = ICK_Pointer_Conversion; 1042 SCS.IncompatibleObjC = IncompatibleObjC; 1043 } else if (IsMemberPointerConversion(From, FromType, ToType, 1044 InOverloadResolution, FromType)) { 1045 // Pointer to member conversions (4.11). 1046 SCS.Second = ICK_Pointer_Member; 1047 } else if (ToType->isBooleanType() && 1048 (FromType->isArithmeticType() || 1049 FromType->isEnumeralType() || 1050 FromType->isAnyPointerType() || 1051 FromType->isBlockPointerType() || 1052 FromType->isMemberPointerType() || 1053 FromType->isNullPtrType())) { 1054 // Boolean conversions (C++ 4.12). 1055 SCS.Second = ICK_Boolean_Conversion; 1056 FromType = Context.BoolTy; 1057 } else if (IsVectorConversion(Context, FromType, ToType, SecondICK)) { 1058 SCS.Second = SecondICK; 1059 FromType = ToType.getUnqualifiedType(); 1060 } else if (!getLangOptions().CPlusPlus && 1061 Context.typesAreCompatible(ToType, FromType)) { 1062 // Compatible conversions (Clang extension for C function overloading) 1063 SCS.Second = ICK_Compatible_Conversion; 1064 FromType = ToType.getUnqualifiedType(); 1065 } else if (IsNoReturnConversion(Context, FromType, ToType, FromType)) { 1066 // Treat a conversion that strips "noreturn" as an identity conversion. 1067 SCS.Second = ICK_NoReturn_Adjustment; 1068 } else { 1069 // No second conversion required. 1070 SCS.Second = ICK_Identity; 1071 } 1072 SCS.setToType(1, FromType); 1073 1074 QualType CanonFrom; 1075 QualType CanonTo; 1076 // The third conversion can be a qualification conversion (C++ 4p1). 1077 if (IsQualificationConversion(FromType, ToType)) { 1078 SCS.Third = ICK_Qualification; 1079 FromType = ToType; 1080 CanonFrom = Context.getCanonicalType(FromType); 1081 CanonTo = Context.getCanonicalType(ToType); 1082 } else { 1083 // No conversion required 1084 SCS.Third = ICK_Identity; 1085 1086 // C++ [over.best.ics]p6: 1087 // [...] Any difference in top-level cv-qualification is 1088 // subsumed by the initialization itself and does not constitute 1089 // a conversion. [...] 1090 CanonFrom = Context.getCanonicalType(FromType); 1091 CanonTo = Context.getCanonicalType(ToType); 1092 if (CanonFrom.getLocalUnqualifiedType() 1093 == CanonTo.getLocalUnqualifiedType() && 1094 (CanonFrom.getLocalCVRQualifiers() != CanonTo.getLocalCVRQualifiers() 1095 || CanonFrom.getObjCGCAttr() != CanonTo.getObjCGCAttr())) { 1096 FromType = ToType; 1097 CanonFrom = CanonTo; 1098 } 1099 } 1100 SCS.setToType(2, FromType); 1101 1102 // If we have not converted the argument type to the parameter type, 1103 // this is a bad conversion sequence. 1104 if (CanonFrom != CanonTo) 1105 return false; 1106 1107 return true; 1108} 1109 1110/// IsIntegralPromotion - Determines whether the conversion from the 1111/// expression From (whose potentially-adjusted type is FromType) to 1112/// ToType is an integral promotion (C++ 4.5). If so, returns true and 1113/// sets PromotedType to the promoted type. 1114bool Sema::IsIntegralPromotion(Expr *From, QualType FromType, QualType ToType) { 1115 const BuiltinType *To = ToType->getAs<BuiltinType>(); 1116 // All integers are built-in. 1117 if (!To) { 1118 return false; 1119 } 1120 1121 // An rvalue of type char, signed char, unsigned char, short int, or 1122 // unsigned short int can be converted to an rvalue of type int if 1123 // int can represent all the values of the source type; otherwise, 1124 // the source rvalue can be converted to an rvalue of type unsigned 1125 // int (C++ 4.5p1). 1126 if (FromType->isPromotableIntegerType() && !FromType->isBooleanType() && 1127 !FromType->isEnumeralType()) { 1128 if (// We can promote any signed, promotable integer type to an int 1129 (FromType->isSignedIntegerType() || 1130 // We can promote any unsigned integer type whose size is 1131 // less than int to an int. 1132 (!FromType->isSignedIntegerType() && 1133 Context.getTypeSize(FromType) < Context.getTypeSize(ToType)))) { 1134 return To->getKind() == BuiltinType::Int; 1135 } 1136 1137 return To->getKind() == BuiltinType::UInt; 1138 } 1139 1140 // An rvalue of type wchar_t (3.9.1) or an enumeration type (7.2) 1141 // can be converted to an rvalue of the first of the following types 1142 // that can represent all the values of its underlying type: int, 1143 // unsigned int, long, or unsigned long (C++ 4.5p2). 1144 1145 // We pre-calculate the promotion type for enum types. 1146 if (const EnumType *FromEnumType = FromType->getAs<EnumType>()) 1147 if (ToType->isIntegerType()) 1148 return Context.hasSameUnqualifiedType(ToType, 1149 FromEnumType->getDecl()->getPromotionType()); 1150 1151 if (FromType->isWideCharType() && ToType->isIntegerType()) { 1152 // Determine whether the type we're converting from is signed or 1153 // unsigned. 1154 bool FromIsSigned; 1155 uint64_t FromSize = Context.getTypeSize(FromType); 1156 1157 // FIXME: Is wchar_t signed or unsigned? We assume it's signed for now. 1158 FromIsSigned = true; 1159 1160 // The types we'll try to promote to, in the appropriate 1161 // order. Try each of these types. 1162 QualType PromoteTypes[6] = { 1163 Context.IntTy, Context.UnsignedIntTy, 1164 Context.LongTy, Context.UnsignedLongTy , 1165 Context.LongLongTy, Context.UnsignedLongLongTy 1166 }; 1167 for (int Idx = 0; Idx < 6; ++Idx) { 1168 uint64_t ToSize = Context.getTypeSize(PromoteTypes[Idx]); 1169 if (FromSize < ToSize || 1170 (FromSize == ToSize && 1171 FromIsSigned == PromoteTypes[Idx]->isSignedIntegerType())) { 1172 // We found the type that we can promote to. If this is the 1173 // type we wanted, we have a promotion. Otherwise, no 1174 // promotion. 1175 return Context.hasSameUnqualifiedType(ToType, PromoteTypes[Idx]); 1176 } 1177 } 1178 } 1179 1180 // An rvalue for an integral bit-field (9.6) can be converted to an 1181 // rvalue of type int if int can represent all the values of the 1182 // bit-field; otherwise, it can be converted to unsigned int if 1183 // unsigned int can represent all the values of the bit-field. If 1184 // the bit-field is larger yet, no integral promotion applies to 1185 // it. If the bit-field has an enumerated type, it is treated as any 1186 // other value of that type for promotion purposes (C++ 4.5p3). 1187 // FIXME: We should delay checking of bit-fields until we actually perform the 1188 // conversion. 1189 using llvm::APSInt; 1190 if (From) 1191 if (FieldDecl *MemberDecl = From->getBitField()) { 1192 APSInt BitWidth; 1193 if (FromType->isIntegralType(Context) && 1194 MemberDecl->getBitWidth()->isIntegerConstantExpr(BitWidth, Context)) { 1195 APSInt ToSize(BitWidth.getBitWidth(), BitWidth.isUnsigned()); 1196 ToSize = Context.getTypeSize(ToType); 1197 1198 // Are we promoting to an int from a bitfield that fits in an int? 1199 if (BitWidth < ToSize || 1200 (FromType->isSignedIntegerType() && BitWidth <= ToSize)) { 1201 return To->getKind() == BuiltinType::Int; 1202 } 1203 1204 // Are we promoting to an unsigned int from an unsigned bitfield 1205 // that fits into an unsigned int? 1206 if (FromType->isUnsignedIntegerType() && BitWidth <= ToSize) { 1207 return To->getKind() == BuiltinType::UInt; 1208 } 1209 1210 return false; 1211 } 1212 } 1213 1214 // An rvalue of type bool can be converted to an rvalue of type int, 1215 // with false becoming zero and true becoming one (C++ 4.5p4). 1216 if (FromType->isBooleanType() && To->getKind() == BuiltinType::Int) { 1217 return true; 1218 } 1219 1220 return false; 1221} 1222 1223/// IsFloatingPointPromotion - Determines whether the conversion from 1224/// FromType to ToType is a floating point promotion (C++ 4.6). If so, 1225/// returns true and sets PromotedType to the promoted type. 1226bool Sema::IsFloatingPointPromotion(QualType FromType, QualType ToType) { 1227 /// An rvalue of type float can be converted to an rvalue of type 1228 /// double. (C++ 4.6p1). 1229 if (const BuiltinType *FromBuiltin = FromType->getAs<BuiltinType>()) 1230 if (const BuiltinType *ToBuiltin = ToType->getAs<BuiltinType>()) { 1231 if (FromBuiltin->getKind() == BuiltinType::Float && 1232 ToBuiltin->getKind() == BuiltinType::Double) 1233 return true; 1234 1235 // C99 6.3.1.5p1: 1236 // When a float is promoted to double or long double, or a 1237 // double is promoted to long double [...]. 1238 if (!getLangOptions().CPlusPlus && 1239 (FromBuiltin->getKind() == BuiltinType::Float || 1240 FromBuiltin->getKind() == BuiltinType::Double) && 1241 (ToBuiltin->getKind() == BuiltinType::LongDouble)) 1242 return true; 1243 } 1244 1245 return false; 1246} 1247 1248/// \brief Determine if a conversion is a complex promotion. 1249/// 1250/// A complex promotion is defined as a complex -> complex conversion 1251/// where the conversion between the underlying real types is a 1252/// floating-point or integral promotion. 1253bool Sema::IsComplexPromotion(QualType FromType, QualType ToType) { 1254 const ComplexType *FromComplex = FromType->getAs<ComplexType>(); 1255 if (!FromComplex) 1256 return false; 1257 1258 const ComplexType *ToComplex = ToType->getAs<ComplexType>(); 1259 if (!ToComplex) 1260 return false; 1261 1262 return IsFloatingPointPromotion(FromComplex->getElementType(), 1263 ToComplex->getElementType()) || 1264 IsIntegralPromotion(0, FromComplex->getElementType(), 1265 ToComplex->getElementType()); 1266} 1267 1268/// BuildSimilarlyQualifiedPointerType - In a pointer conversion from 1269/// the pointer type FromPtr to a pointer to type ToPointee, with the 1270/// same type qualifiers as FromPtr has on its pointee type. ToType, 1271/// if non-empty, will be a pointer to ToType that may or may not have 1272/// the right set of qualifiers on its pointee. 1273static QualType 1274BuildSimilarlyQualifiedPointerType(const PointerType *FromPtr, 1275 QualType ToPointee, QualType ToType, 1276 ASTContext &Context) { 1277 QualType CanonFromPointee = Context.getCanonicalType(FromPtr->getPointeeType()); 1278 QualType CanonToPointee = Context.getCanonicalType(ToPointee); 1279 Qualifiers Quals = CanonFromPointee.getQualifiers(); 1280 1281 // Exact qualifier match -> return the pointer type we're converting to. 1282 if (CanonToPointee.getLocalQualifiers() == Quals) { 1283 // ToType is exactly what we need. Return it. 1284 if (!ToType.isNull()) 1285 return ToType.getUnqualifiedType(); 1286 1287 // Build a pointer to ToPointee. It has the right qualifiers 1288 // already. 1289 return Context.getPointerType(ToPointee); 1290 } 1291 1292 // Just build a canonical type that has the right qualifiers. 1293 return Context.getPointerType( 1294 Context.getQualifiedType(CanonToPointee.getLocalUnqualifiedType(), 1295 Quals)); 1296} 1297 1298/// BuildSimilarlyQualifiedObjCObjectPointerType - In a pointer conversion from 1299/// the FromType, which is an objective-c pointer, to ToType, which may or may 1300/// not have the right set of qualifiers. 1301static QualType 1302BuildSimilarlyQualifiedObjCObjectPointerType(QualType FromType, 1303 QualType ToType, 1304 ASTContext &Context) { 1305 QualType CanonFromType = Context.getCanonicalType(FromType); 1306 QualType CanonToType = Context.getCanonicalType(ToType); 1307 Qualifiers Quals = CanonFromType.getQualifiers(); 1308 1309 // Exact qualifier match -> return the pointer type we're converting to. 1310 if (CanonToType.getLocalQualifiers() == Quals) 1311 return ToType; 1312 1313 // Just build a canonical type that has the right qualifiers. 1314 return Context.getQualifiedType(CanonToType.getLocalUnqualifiedType(), Quals); 1315} 1316 1317static bool isNullPointerConstantForConversion(Expr *Expr, 1318 bool InOverloadResolution, 1319 ASTContext &Context) { 1320 // Handle value-dependent integral null pointer constants correctly. 1321 // http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#903 1322 if (Expr->isValueDependent() && !Expr->isTypeDependent() && 1323 Expr->getType()->isIntegerType() && !Expr->getType()->isEnumeralType()) 1324 return !InOverloadResolution; 1325 1326 return Expr->isNullPointerConstant(Context, 1327 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull 1328 : Expr::NPC_ValueDependentIsNull); 1329} 1330 1331/// IsPointerConversion - Determines whether the conversion of the 1332/// expression From, which has the (possibly adjusted) type FromType, 1333/// can be converted to the type ToType via a pointer conversion (C++ 1334/// 4.10). If so, returns true and places the converted type (that 1335/// might differ from ToType in its cv-qualifiers at some level) into 1336/// ConvertedType. 1337/// 1338/// This routine also supports conversions to and from block pointers 1339/// and conversions with Objective-C's 'id', 'id<protocols...>', and 1340/// pointers to interfaces. FIXME: Once we've determined the 1341/// appropriate overloading rules for Objective-C, we may want to 1342/// split the Objective-C checks into a different routine; however, 1343/// GCC seems to consider all of these conversions to be pointer 1344/// conversions, so for now they live here. IncompatibleObjC will be 1345/// set if the conversion is an allowed Objective-C conversion that 1346/// should result in a warning. 1347bool Sema::IsPointerConversion(Expr *From, QualType FromType, QualType ToType, 1348 bool InOverloadResolution, 1349 QualType& ConvertedType, 1350 bool &IncompatibleObjC) { 1351 IncompatibleObjC = false; 1352 if (isObjCPointerConversion(FromType, ToType, ConvertedType, IncompatibleObjC)) 1353 return true; 1354 1355 // Conversion from a null pointer constant to any Objective-C pointer type. 1356 if (ToType->isObjCObjectPointerType() && 1357 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1358 ConvertedType = ToType; 1359 return true; 1360 } 1361 1362 // Blocks: Block pointers can be converted to void*. 1363 if (FromType->isBlockPointerType() && ToType->isPointerType() && 1364 ToType->getAs<PointerType>()->getPointeeType()->isVoidType()) { 1365 ConvertedType = ToType; 1366 return true; 1367 } 1368 // Blocks: A null pointer constant can be converted to a block 1369 // pointer type. 1370 if (ToType->isBlockPointerType() && 1371 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1372 ConvertedType = ToType; 1373 return true; 1374 } 1375 1376 // If the left-hand-side is nullptr_t, the right side can be a null 1377 // pointer constant. 1378 if (ToType->isNullPtrType() && 1379 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1380 ConvertedType = ToType; 1381 return true; 1382 } 1383 1384 const PointerType* ToTypePtr = ToType->getAs<PointerType>(); 1385 if (!ToTypePtr) 1386 return false; 1387 1388 // A null pointer constant can be converted to a pointer type (C++ 4.10p1). 1389 if (isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1390 ConvertedType = ToType; 1391 return true; 1392 } 1393 1394 // Beyond this point, both types need to be pointers 1395 // , including objective-c pointers. 1396 QualType ToPointeeType = ToTypePtr->getPointeeType(); 1397 if (FromType->isObjCObjectPointerType() && ToPointeeType->isVoidType()) { 1398 ConvertedType = BuildSimilarlyQualifiedObjCObjectPointerType(FromType, 1399 ToType, Context); 1400 return true; 1401 1402 } 1403 const PointerType *FromTypePtr = FromType->getAs<PointerType>(); 1404 if (!FromTypePtr) 1405 return false; 1406 1407 QualType FromPointeeType = FromTypePtr->getPointeeType(); 1408 1409 // An rvalue of type "pointer to cv T," where T is an object type, 1410 // can be converted to an rvalue of type "pointer to cv void" (C++ 1411 // 4.10p2). 1412 if (FromPointeeType->isIncompleteOrObjectType() && 1413 ToPointeeType->isVoidType()) { 1414 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1415 ToPointeeType, 1416 ToType, Context); 1417 return true; 1418 } 1419 1420 // When we're overloading in C, we allow a special kind of pointer 1421 // conversion for compatible-but-not-identical pointee types. 1422 if (!getLangOptions().CPlusPlus && 1423 Context.typesAreCompatible(FromPointeeType, ToPointeeType)) { 1424 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1425 ToPointeeType, 1426 ToType, Context); 1427 return true; 1428 } 1429 1430 // C++ [conv.ptr]p3: 1431 // 1432 // An rvalue of type "pointer to cv D," where D is a class type, 1433 // can be converted to an rvalue of type "pointer to cv B," where 1434 // B is a base class (clause 10) of D. If B is an inaccessible 1435 // (clause 11) or ambiguous (10.2) base class of D, a program that 1436 // necessitates this conversion is ill-formed. The result of the 1437 // conversion is a pointer to the base class sub-object of the 1438 // derived class object. The null pointer value is converted to 1439 // the null pointer value of the destination type. 1440 // 1441 // Note that we do not check for ambiguity or inaccessibility 1442 // here. That is handled by CheckPointerConversion. 1443 if (getLangOptions().CPlusPlus && 1444 FromPointeeType->isRecordType() && ToPointeeType->isRecordType() && 1445 !Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType) && 1446 !RequireCompleteType(From->getLocStart(), FromPointeeType, PDiag()) && 1447 IsDerivedFrom(FromPointeeType, ToPointeeType)) { 1448 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1449 ToPointeeType, 1450 ToType, Context); 1451 return true; 1452 } 1453 1454 return false; 1455} 1456 1457/// isObjCPointerConversion - Determines whether this is an 1458/// Objective-C pointer conversion. Subroutine of IsPointerConversion, 1459/// with the same arguments and return values. 1460bool Sema::isObjCPointerConversion(QualType FromType, QualType ToType, 1461 QualType& ConvertedType, 1462 bool &IncompatibleObjC) { 1463 if (!getLangOptions().ObjC1) 1464 return false; 1465 1466 // First, we handle all conversions on ObjC object pointer types. 1467 const ObjCObjectPointerType* ToObjCPtr = ToType->getAs<ObjCObjectPointerType>(); 1468 const ObjCObjectPointerType *FromObjCPtr = 1469 FromType->getAs<ObjCObjectPointerType>(); 1470 1471 if (ToObjCPtr && FromObjCPtr) { 1472 // Objective C++: We're able to convert between "id" or "Class" and a 1473 // pointer to any interface (in both directions). 1474 if (ToObjCPtr->isObjCBuiltinType() && FromObjCPtr->isObjCBuiltinType()) { 1475 ConvertedType = ToType; 1476 return true; 1477 } 1478 // Conversions with Objective-C's id<...>. 1479 if ((FromObjCPtr->isObjCQualifiedIdType() || 1480 ToObjCPtr->isObjCQualifiedIdType()) && 1481 Context.ObjCQualifiedIdTypesAreCompatible(ToType, FromType, 1482 /*compare=*/false)) { 1483 ConvertedType = ToType; 1484 return true; 1485 } 1486 // Objective C++: We're able to convert from a pointer to an 1487 // interface to a pointer to a different interface. 1488 if (Context.canAssignObjCInterfaces(ToObjCPtr, FromObjCPtr)) { 1489 const ObjCInterfaceType* LHS = ToObjCPtr->getInterfaceType(); 1490 const ObjCInterfaceType* RHS = FromObjCPtr->getInterfaceType(); 1491 if (getLangOptions().CPlusPlus && LHS && RHS && 1492 !ToObjCPtr->getPointeeType().isAtLeastAsQualifiedAs( 1493 FromObjCPtr->getPointeeType())) 1494 return false; 1495 ConvertedType = ToType; 1496 return true; 1497 } 1498 1499 if (Context.canAssignObjCInterfaces(FromObjCPtr, ToObjCPtr)) { 1500 // Okay: this is some kind of implicit downcast of Objective-C 1501 // interfaces, which is permitted. However, we're going to 1502 // complain about it. 1503 IncompatibleObjC = true; 1504 ConvertedType = FromType; 1505 return true; 1506 } 1507 } 1508 // Beyond this point, both types need to be C pointers or block pointers. 1509 QualType ToPointeeType; 1510 if (const PointerType *ToCPtr = ToType->getAs<PointerType>()) 1511 ToPointeeType = ToCPtr->getPointeeType(); 1512 else if (const BlockPointerType *ToBlockPtr = 1513 ToType->getAs<BlockPointerType>()) { 1514 // Objective C++: We're able to convert from a pointer to any object 1515 // to a block pointer type. 1516 if (FromObjCPtr && FromObjCPtr->isObjCBuiltinType()) { 1517 ConvertedType = ToType; 1518 return true; 1519 } 1520 ToPointeeType = ToBlockPtr->getPointeeType(); 1521 } 1522 else if (FromType->getAs<BlockPointerType>() && 1523 ToObjCPtr && ToObjCPtr->isObjCBuiltinType()) { 1524 // Objective C++: We're able to convert from a block pointer type to a 1525 // pointer to any object. 1526 ConvertedType = ToType; 1527 return true; 1528 } 1529 else 1530 return false; 1531 1532 QualType FromPointeeType; 1533 if (const PointerType *FromCPtr = FromType->getAs<PointerType>()) 1534 FromPointeeType = FromCPtr->getPointeeType(); 1535 else if (const BlockPointerType *FromBlockPtr = FromType->getAs<BlockPointerType>()) 1536 FromPointeeType = FromBlockPtr->getPointeeType(); 1537 else 1538 return false; 1539 1540 // If we have pointers to pointers, recursively check whether this 1541 // is an Objective-C conversion. 1542 if (FromPointeeType->isPointerType() && ToPointeeType->isPointerType() && 1543 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, 1544 IncompatibleObjC)) { 1545 // We always complain about this conversion. 1546 IncompatibleObjC = true; 1547 ConvertedType = ToType; 1548 return true; 1549 } 1550 // Allow conversion of pointee being objective-c pointer to another one; 1551 // as in I* to id. 1552 if (FromPointeeType->getAs<ObjCObjectPointerType>() && 1553 ToPointeeType->getAs<ObjCObjectPointerType>() && 1554 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, 1555 IncompatibleObjC)) { 1556 ConvertedType = ToType; 1557 return true; 1558 } 1559 1560 // If we have pointers to functions or blocks, check whether the only 1561 // differences in the argument and result types are in Objective-C 1562 // pointer conversions. If so, we permit the conversion (but 1563 // complain about it). 1564 const FunctionProtoType *FromFunctionType 1565 = FromPointeeType->getAs<FunctionProtoType>(); 1566 const FunctionProtoType *ToFunctionType 1567 = ToPointeeType->getAs<FunctionProtoType>(); 1568 if (FromFunctionType && ToFunctionType) { 1569 // If the function types are exactly the same, this isn't an 1570 // Objective-C pointer conversion. 1571 if (Context.getCanonicalType(FromPointeeType) 1572 == Context.getCanonicalType(ToPointeeType)) 1573 return false; 1574 1575 // Perform the quick checks that will tell us whether these 1576 // function types are obviously different. 1577 if (FromFunctionType->getNumArgs() != ToFunctionType->getNumArgs() || 1578 FromFunctionType->isVariadic() != ToFunctionType->isVariadic() || 1579 FromFunctionType->getTypeQuals() != ToFunctionType->getTypeQuals()) 1580 return false; 1581 1582 bool HasObjCConversion = false; 1583 if (Context.getCanonicalType(FromFunctionType->getResultType()) 1584 == Context.getCanonicalType(ToFunctionType->getResultType())) { 1585 // Okay, the types match exactly. Nothing to do. 1586 } else if (isObjCPointerConversion(FromFunctionType->getResultType(), 1587 ToFunctionType->getResultType(), 1588 ConvertedType, IncompatibleObjC)) { 1589 // Okay, we have an Objective-C pointer conversion. 1590 HasObjCConversion = true; 1591 } else { 1592 // Function types are too different. Abort. 1593 return false; 1594 } 1595 1596 // Check argument types. 1597 for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumArgs(); 1598 ArgIdx != NumArgs; ++ArgIdx) { 1599 QualType FromArgType = FromFunctionType->getArgType(ArgIdx); 1600 QualType ToArgType = ToFunctionType->getArgType(ArgIdx); 1601 if (Context.getCanonicalType(FromArgType) 1602 == Context.getCanonicalType(ToArgType)) { 1603 // Okay, the types match exactly. Nothing to do. 1604 } else if (isObjCPointerConversion(FromArgType, ToArgType, 1605 ConvertedType, IncompatibleObjC)) { 1606 // Okay, we have an Objective-C pointer conversion. 1607 HasObjCConversion = true; 1608 } else { 1609 // Argument types are too different. Abort. 1610 return false; 1611 } 1612 } 1613 1614 if (HasObjCConversion) { 1615 // We had an Objective-C conversion. Allow this pointer 1616 // conversion, but complain about it. 1617 ConvertedType = ToType; 1618 IncompatibleObjC = true; 1619 return true; 1620 } 1621 } 1622 1623 return false; 1624} 1625 1626/// FunctionArgTypesAreEqual - This routine checks two function proto types 1627/// for equlity of their argument types. Caller has already checked that 1628/// they have same number of arguments. This routine assumes that Objective-C 1629/// pointer types which only differ in their protocol qualifiers are equal. 1630bool Sema::FunctionArgTypesAreEqual(FunctionProtoType* OldType, 1631 FunctionProtoType* NewType){ 1632 if (!getLangOptions().ObjC1) 1633 return std::equal(OldType->arg_type_begin(), OldType->arg_type_end(), 1634 NewType->arg_type_begin()); 1635 1636 for (FunctionProtoType::arg_type_iterator O = OldType->arg_type_begin(), 1637 N = NewType->arg_type_begin(), 1638 E = OldType->arg_type_end(); O && (O != E); ++O, ++N) { 1639 QualType ToType = (*O); 1640 QualType FromType = (*N); 1641 if (ToType != FromType) { 1642 if (const PointerType *PTTo = ToType->getAs<PointerType>()) { 1643 if (const PointerType *PTFr = FromType->getAs<PointerType>()) 1644 if ((PTTo->getPointeeType()->isObjCQualifiedIdType() && 1645 PTFr->getPointeeType()->isObjCQualifiedIdType()) || 1646 (PTTo->getPointeeType()->isObjCQualifiedClassType() && 1647 PTFr->getPointeeType()->isObjCQualifiedClassType())) 1648 continue; 1649 } 1650 else if (const ObjCObjectPointerType *PTTo = 1651 ToType->getAs<ObjCObjectPointerType>()) { 1652 if (const ObjCObjectPointerType *PTFr = 1653 FromType->getAs<ObjCObjectPointerType>()) 1654 if (PTTo->getInterfaceDecl() == PTFr->getInterfaceDecl()) 1655 continue; 1656 } 1657 return false; 1658 } 1659 } 1660 return true; 1661} 1662 1663/// CheckPointerConversion - Check the pointer conversion from the 1664/// expression From to the type ToType. This routine checks for 1665/// ambiguous or inaccessible derived-to-base pointer 1666/// conversions for which IsPointerConversion has already returned 1667/// true. It returns true and produces a diagnostic if there was an 1668/// error, or returns false otherwise. 1669bool Sema::CheckPointerConversion(Expr *From, QualType ToType, 1670 CastExpr::CastKind &Kind, 1671 CXXCastPath& BasePath, 1672 bool IgnoreBaseAccess) { 1673 QualType FromType = From->getType(); 1674 1675 if (CXXBoolLiteralExpr* LitBool 1676 = dyn_cast<CXXBoolLiteralExpr>(From->IgnoreParens())) 1677 if (LitBool->getValue() == false) 1678 Diag(LitBool->getExprLoc(), diag::warn_init_pointer_from_false) 1679 << ToType; 1680 1681 if (const PointerType *FromPtrType = FromType->getAs<PointerType>()) 1682 if (const PointerType *ToPtrType = ToType->getAs<PointerType>()) { 1683 QualType FromPointeeType = FromPtrType->getPointeeType(), 1684 ToPointeeType = ToPtrType->getPointeeType(); 1685 1686 if (FromPointeeType->isRecordType() && ToPointeeType->isRecordType() && 1687 !Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType)) { 1688 // We must have a derived-to-base conversion. Check an 1689 // ambiguous or inaccessible conversion. 1690 if (CheckDerivedToBaseConversion(FromPointeeType, ToPointeeType, 1691 From->getExprLoc(), 1692 From->getSourceRange(), &BasePath, 1693 IgnoreBaseAccess)) 1694 return true; 1695 1696 // The conversion was successful. 1697 Kind = CastExpr::CK_DerivedToBase; 1698 } 1699 } 1700 if (const ObjCObjectPointerType *FromPtrType = 1701 FromType->getAs<ObjCObjectPointerType>()) 1702 if (const ObjCObjectPointerType *ToPtrType = 1703 ToType->getAs<ObjCObjectPointerType>()) { 1704 // Objective-C++ conversions are always okay. 1705 // FIXME: We should have a different class of conversions for the 1706 // Objective-C++ implicit conversions. 1707 if (FromPtrType->isObjCBuiltinType() || ToPtrType->isObjCBuiltinType()) 1708 return false; 1709 1710 } 1711 return false; 1712} 1713 1714/// IsMemberPointerConversion - Determines whether the conversion of the 1715/// expression From, which has the (possibly adjusted) type FromType, can be 1716/// converted to the type ToType via a member pointer conversion (C++ 4.11). 1717/// If so, returns true and places the converted type (that might differ from 1718/// ToType in its cv-qualifiers at some level) into ConvertedType. 1719bool Sema::IsMemberPointerConversion(Expr *From, QualType FromType, 1720 QualType ToType, 1721 bool InOverloadResolution, 1722 QualType &ConvertedType) { 1723 const MemberPointerType *ToTypePtr = ToType->getAs<MemberPointerType>(); 1724 if (!ToTypePtr) 1725 return false; 1726 1727 // A null pointer constant can be converted to a member pointer (C++ 4.11p1) 1728 if (From->isNullPointerConstant(Context, 1729 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull 1730 : Expr::NPC_ValueDependentIsNull)) { 1731 ConvertedType = ToType; 1732 return true; 1733 } 1734 1735 // Otherwise, both types have to be member pointers. 1736 const MemberPointerType *FromTypePtr = FromType->getAs<MemberPointerType>(); 1737 if (!FromTypePtr) 1738 return false; 1739 1740 // A pointer to member of B can be converted to a pointer to member of D, 1741 // where D is derived from B (C++ 4.11p2). 1742 QualType FromClass(FromTypePtr->getClass(), 0); 1743 QualType ToClass(ToTypePtr->getClass(), 0); 1744 // FIXME: What happens when these are dependent? Is this function even called? 1745 1746 if (IsDerivedFrom(ToClass, FromClass)) { 1747 ConvertedType = Context.getMemberPointerType(FromTypePtr->getPointeeType(), 1748 ToClass.getTypePtr()); 1749 return true; 1750 } 1751 1752 return false; 1753} 1754 1755/// CheckMemberPointerConversion - Check the member pointer conversion from the 1756/// expression From to the type ToType. This routine checks for ambiguous or 1757/// virtual or inaccessible base-to-derived member pointer conversions 1758/// for which IsMemberPointerConversion has already returned true. It returns 1759/// true and produces a diagnostic if there was an error, or returns false 1760/// otherwise. 1761bool Sema::CheckMemberPointerConversion(Expr *From, QualType ToType, 1762 CastExpr::CastKind &Kind, 1763 CXXCastPath &BasePath, 1764 bool IgnoreBaseAccess) { 1765 QualType FromType = From->getType(); 1766 const MemberPointerType *FromPtrType = FromType->getAs<MemberPointerType>(); 1767 if (!FromPtrType) { 1768 // This must be a null pointer to member pointer conversion 1769 assert(From->isNullPointerConstant(Context, 1770 Expr::NPC_ValueDependentIsNull) && 1771 "Expr must be null pointer constant!"); 1772 Kind = CastExpr::CK_NullToMemberPointer; 1773 return false; 1774 } 1775 1776 const MemberPointerType *ToPtrType = ToType->getAs<MemberPointerType>(); 1777 assert(ToPtrType && "No member pointer cast has a target type " 1778 "that is not a member pointer."); 1779 1780 QualType FromClass = QualType(FromPtrType->getClass(), 0); 1781 QualType ToClass = QualType(ToPtrType->getClass(), 0); 1782 1783 // FIXME: What about dependent types? 1784 assert(FromClass->isRecordType() && "Pointer into non-class."); 1785 assert(ToClass->isRecordType() && "Pointer into non-class."); 1786 1787 CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true, 1788 /*DetectVirtual=*/true); 1789 bool DerivationOkay = IsDerivedFrom(ToClass, FromClass, Paths); 1790 assert(DerivationOkay && 1791 "Should not have been called if derivation isn't OK."); 1792 (void)DerivationOkay; 1793 1794 if (Paths.isAmbiguous(Context.getCanonicalType(FromClass). 1795 getUnqualifiedType())) { 1796 std::string PathDisplayStr = getAmbiguousPathsDisplayString(Paths); 1797 Diag(From->getExprLoc(), diag::err_ambiguous_memptr_conv) 1798 << 0 << FromClass << ToClass << PathDisplayStr << From->getSourceRange(); 1799 return true; 1800 } 1801 1802 if (const RecordType *VBase = Paths.getDetectedVirtual()) { 1803 Diag(From->getExprLoc(), diag::err_memptr_conv_via_virtual) 1804 << FromClass << ToClass << QualType(VBase, 0) 1805 << From->getSourceRange(); 1806 return true; 1807 } 1808 1809 if (!IgnoreBaseAccess) 1810 CheckBaseClassAccess(From->getExprLoc(), FromClass, ToClass, 1811 Paths.front(), 1812 diag::err_downcast_from_inaccessible_base); 1813 1814 // Must be a base to derived member conversion. 1815 BuildBasePathArray(Paths, BasePath); 1816 Kind = CastExpr::CK_BaseToDerivedMemberPointer; 1817 return false; 1818} 1819 1820/// IsQualificationConversion - Determines whether the conversion from 1821/// an rvalue of type FromType to ToType is a qualification conversion 1822/// (C++ 4.4). 1823bool 1824Sema::IsQualificationConversion(QualType FromType, QualType ToType) { 1825 FromType = Context.getCanonicalType(FromType); 1826 ToType = Context.getCanonicalType(ToType); 1827 1828 // If FromType and ToType are the same type, this is not a 1829 // qualification conversion. 1830 if (FromType.getUnqualifiedType() == ToType.getUnqualifiedType()) 1831 return false; 1832 1833 // (C++ 4.4p4): 1834 // A conversion can add cv-qualifiers at levels other than the first 1835 // in multi-level pointers, subject to the following rules: [...] 1836 bool PreviousToQualsIncludeConst = true; 1837 bool UnwrappedAnyPointer = false; 1838 while (Context.UnwrapSimilarPointerTypes(FromType, ToType)) { 1839 // Within each iteration of the loop, we check the qualifiers to 1840 // determine if this still looks like a qualification 1841 // conversion. Then, if all is well, we unwrap one more level of 1842 // pointers or pointers-to-members and do it all again 1843 // until there are no more pointers or pointers-to-members left to 1844 // unwrap. 1845 UnwrappedAnyPointer = true; 1846 1847 // -- for every j > 0, if const is in cv 1,j then const is in cv 1848 // 2,j, and similarly for volatile. 1849 if (!ToType.isAtLeastAsQualifiedAs(FromType)) 1850 return false; 1851 1852 // -- if the cv 1,j and cv 2,j are different, then const is in 1853 // every cv for 0 < k < j. 1854 if (FromType.getCVRQualifiers() != ToType.getCVRQualifiers() 1855 && !PreviousToQualsIncludeConst) 1856 return false; 1857 1858 // Keep track of whether all prior cv-qualifiers in the "to" type 1859 // include const. 1860 PreviousToQualsIncludeConst 1861 = PreviousToQualsIncludeConst && ToType.isConstQualified(); 1862 } 1863 1864 // We are left with FromType and ToType being the pointee types 1865 // after unwrapping the original FromType and ToType the same number 1866 // of types. If we unwrapped any pointers, and if FromType and 1867 // ToType have the same unqualified type (since we checked 1868 // qualifiers above), then this is a qualification conversion. 1869 return UnwrappedAnyPointer && Context.hasSameUnqualifiedType(FromType,ToType); 1870} 1871 1872/// Determines whether there is a user-defined conversion sequence 1873/// (C++ [over.ics.user]) that converts expression From to the type 1874/// ToType. If such a conversion exists, User will contain the 1875/// user-defined conversion sequence that performs such a conversion 1876/// and this routine will return true. Otherwise, this routine returns 1877/// false and User is unspecified. 1878/// 1879/// \param AllowExplicit true if the conversion should consider C++0x 1880/// "explicit" conversion functions as well as non-explicit conversion 1881/// functions (C++0x [class.conv.fct]p2). 1882OverloadingResult Sema::IsUserDefinedConversion(Expr *From, QualType ToType, 1883 UserDefinedConversionSequence& User, 1884 OverloadCandidateSet& CandidateSet, 1885 bool AllowExplicit) { 1886 // Whether we will only visit constructors. 1887 bool ConstructorsOnly = false; 1888 1889 // If the type we are conversion to is a class type, enumerate its 1890 // constructors. 1891 if (const RecordType *ToRecordType = ToType->getAs<RecordType>()) { 1892 // C++ [over.match.ctor]p1: 1893 // When objects of class type are direct-initialized (8.5), or 1894 // copy-initialized from an expression of the same or a 1895 // derived class type (8.5), overload resolution selects the 1896 // constructor. [...] For copy-initialization, the candidate 1897 // functions are all the converting constructors (12.3.1) of 1898 // that class. The argument list is the expression-list within 1899 // the parentheses of the initializer. 1900 if (Context.hasSameUnqualifiedType(ToType, From->getType()) || 1901 (From->getType()->getAs<RecordType>() && 1902 IsDerivedFrom(From->getType(), ToType))) 1903 ConstructorsOnly = true; 1904 1905 if (RequireCompleteType(From->getLocStart(), ToType, PDiag())) { 1906 // We're not going to find any constructors. 1907 } else if (CXXRecordDecl *ToRecordDecl 1908 = dyn_cast<CXXRecordDecl>(ToRecordType->getDecl())) { 1909 DeclContext::lookup_iterator Con, ConEnd; 1910 for (llvm::tie(Con, ConEnd) = LookupConstructors(ToRecordDecl); 1911 Con != ConEnd; ++Con) { 1912 NamedDecl *D = *Con; 1913 DeclAccessPair FoundDecl = DeclAccessPair::make(D, D->getAccess()); 1914 1915 // Find the constructor (which may be a template). 1916 CXXConstructorDecl *Constructor = 0; 1917 FunctionTemplateDecl *ConstructorTmpl 1918 = dyn_cast<FunctionTemplateDecl>(D); 1919 if (ConstructorTmpl) 1920 Constructor 1921 = cast<CXXConstructorDecl>(ConstructorTmpl->getTemplatedDecl()); 1922 else 1923 Constructor = cast<CXXConstructorDecl>(D); 1924 1925 if (!Constructor->isInvalidDecl() && 1926 Constructor->isConvertingConstructor(AllowExplicit)) { 1927 if (ConstructorTmpl) 1928 AddTemplateOverloadCandidate(ConstructorTmpl, FoundDecl, 1929 /*ExplicitArgs*/ 0, 1930 &From, 1, CandidateSet, 1931 /*SuppressUserConversions=*/!ConstructorsOnly); 1932 else 1933 // Allow one user-defined conversion when user specifies a 1934 // From->ToType conversion via an static cast (c-style, etc). 1935 AddOverloadCandidate(Constructor, FoundDecl, 1936 &From, 1, CandidateSet, 1937 /*SuppressUserConversions=*/!ConstructorsOnly); 1938 } 1939 } 1940 } 1941 } 1942 1943 // Enumerate conversion functions, if we're allowed to. 1944 if (ConstructorsOnly) { 1945 } else if (RequireCompleteType(From->getLocStart(), From->getType(), 1946 PDiag(0) << From->getSourceRange())) { 1947 // No conversion functions from incomplete types. 1948 } else if (const RecordType *FromRecordType 1949 = From->getType()->getAs<RecordType>()) { 1950 if (CXXRecordDecl *FromRecordDecl 1951 = dyn_cast<CXXRecordDecl>(FromRecordType->getDecl())) { 1952 // Add all of the conversion functions as candidates. 1953 const UnresolvedSetImpl *Conversions 1954 = FromRecordDecl->getVisibleConversionFunctions(); 1955 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 1956 E = Conversions->end(); I != E; ++I) { 1957 DeclAccessPair FoundDecl = I.getPair(); 1958 NamedDecl *D = FoundDecl.getDecl(); 1959 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext()); 1960 if (isa<UsingShadowDecl>(D)) 1961 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 1962 1963 CXXConversionDecl *Conv; 1964 FunctionTemplateDecl *ConvTemplate; 1965 if ((ConvTemplate = dyn_cast<FunctionTemplateDecl>(D))) 1966 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 1967 else 1968 Conv = cast<CXXConversionDecl>(D); 1969 1970 if (AllowExplicit || !Conv->isExplicit()) { 1971 if (ConvTemplate) 1972 AddTemplateConversionCandidate(ConvTemplate, FoundDecl, 1973 ActingContext, From, ToType, 1974 CandidateSet); 1975 else 1976 AddConversionCandidate(Conv, FoundDecl, ActingContext, 1977 From, ToType, CandidateSet); 1978 } 1979 } 1980 } 1981 } 1982 1983 OverloadCandidateSet::iterator Best; 1984 switch (BestViableFunction(CandidateSet, From->getLocStart(), Best)) { 1985 case OR_Success: 1986 // Record the standard conversion we used and the conversion function. 1987 if (CXXConstructorDecl *Constructor 1988 = dyn_cast<CXXConstructorDecl>(Best->Function)) { 1989 // C++ [over.ics.user]p1: 1990 // If the user-defined conversion is specified by a 1991 // constructor (12.3.1), the initial standard conversion 1992 // sequence converts the source type to the type required by 1993 // the argument of the constructor. 1994 // 1995 QualType ThisType = Constructor->getThisType(Context); 1996 if (Best->Conversions[0].isEllipsis()) 1997 User.EllipsisConversion = true; 1998 else { 1999 User.Before = Best->Conversions[0].Standard; 2000 User.EllipsisConversion = false; 2001 } 2002 User.ConversionFunction = Constructor; 2003 User.After.setAsIdentityConversion(); 2004 User.After.setFromType( 2005 ThisType->getAs<PointerType>()->getPointeeType()); 2006 User.After.setAllToTypes(ToType); 2007 return OR_Success; 2008 } else if (CXXConversionDecl *Conversion 2009 = dyn_cast<CXXConversionDecl>(Best->Function)) { 2010 // C++ [over.ics.user]p1: 2011 // 2012 // [...] If the user-defined conversion is specified by a 2013 // conversion function (12.3.2), the initial standard 2014 // conversion sequence converts the source type to the 2015 // implicit object parameter of the conversion function. 2016 User.Before = Best->Conversions[0].Standard; 2017 User.ConversionFunction = Conversion; 2018 User.EllipsisConversion = false; 2019 2020 // C++ [over.ics.user]p2: 2021 // The second standard conversion sequence converts the 2022 // result of the user-defined conversion to the target type 2023 // for the sequence. Since an implicit conversion sequence 2024 // is an initialization, the special rules for 2025 // initialization by user-defined conversion apply when 2026 // selecting the best user-defined conversion for a 2027 // user-defined conversion sequence (see 13.3.3 and 2028 // 13.3.3.1). 2029 User.After = Best->FinalConversion; 2030 return OR_Success; 2031 } else { 2032 assert(false && "Not a constructor or conversion function?"); 2033 return OR_No_Viable_Function; 2034 } 2035 2036 case OR_No_Viable_Function: 2037 return OR_No_Viable_Function; 2038 case OR_Deleted: 2039 // No conversion here! We're done. 2040 return OR_Deleted; 2041 2042 case OR_Ambiguous: 2043 return OR_Ambiguous; 2044 } 2045 2046 return OR_No_Viable_Function; 2047} 2048 2049bool 2050Sema::DiagnoseMultipleUserDefinedConversion(Expr *From, QualType ToType) { 2051 ImplicitConversionSequence ICS; 2052 OverloadCandidateSet CandidateSet(From->getExprLoc()); 2053 OverloadingResult OvResult = 2054 IsUserDefinedConversion(From, ToType, ICS.UserDefined, 2055 CandidateSet, false); 2056 if (OvResult == OR_Ambiguous) 2057 Diag(From->getSourceRange().getBegin(), 2058 diag::err_typecheck_ambiguous_condition) 2059 << From->getType() << ToType << From->getSourceRange(); 2060 else if (OvResult == OR_No_Viable_Function && !CandidateSet.empty()) 2061 Diag(From->getSourceRange().getBegin(), 2062 diag::err_typecheck_nonviable_condition) 2063 << From->getType() << ToType << From->getSourceRange(); 2064 else 2065 return false; 2066 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, &From, 1); 2067 return true; 2068} 2069 2070/// CompareImplicitConversionSequences - Compare two implicit 2071/// conversion sequences to determine whether one is better than the 2072/// other or if they are indistinguishable (C++ 13.3.3.2). 2073ImplicitConversionSequence::CompareKind 2074Sema::CompareImplicitConversionSequences(const ImplicitConversionSequence& ICS1, 2075 const ImplicitConversionSequence& ICS2) 2076{ 2077 // (C++ 13.3.3.2p2): When comparing the basic forms of implicit 2078 // conversion sequences (as defined in 13.3.3.1) 2079 // -- a standard conversion sequence (13.3.3.1.1) is a better 2080 // conversion sequence than a user-defined conversion sequence or 2081 // an ellipsis conversion sequence, and 2082 // -- a user-defined conversion sequence (13.3.3.1.2) is a better 2083 // conversion sequence than an ellipsis conversion sequence 2084 // (13.3.3.1.3). 2085 // 2086 // C++0x [over.best.ics]p10: 2087 // For the purpose of ranking implicit conversion sequences as 2088 // described in 13.3.3.2, the ambiguous conversion sequence is 2089 // treated as a user-defined sequence that is indistinguishable 2090 // from any other user-defined conversion sequence. 2091 if (ICS1.getKindRank() < ICS2.getKindRank()) 2092 return ImplicitConversionSequence::Better; 2093 else if (ICS2.getKindRank() < ICS1.getKindRank()) 2094 return ImplicitConversionSequence::Worse; 2095 2096 // The following checks require both conversion sequences to be of 2097 // the same kind. 2098 if (ICS1.getKind() != ICS2.getKind()) 2099 return ImplicitConversionSequence::Indistinguishable; 2100 2101 // Two implicit conversion sequences of the same form are 2102 // indistinguishable conversion sequences unless one of the 2103 // following rules apply: (C++ 13.3.3.2p3): 2104 if (ICS1.isStandard()) 2105 return CompareStandardConversionSequences(ICS1.Standard, ICS2.Standard); 2106 else if (ICS1.isUserDefined()) { 2107 // User-defined conversion sequence U1 is a better conversion 2108 // sequence than another user-defined conversion sequence U2 if 2109 // they contain the same user-defined conversion function or 2110 // constructor and if the second standard conversion sequence of 2111 // U1 is better than the second standard conversion sequence of 2112 // U2 (C++ 13.3.3.2p3). 2113 if (ICS1.UserDefined.ConversionFunction == 2114 ICS2.UserDefined.ConversionFunction) 2115 return CompareStandardConversionSequences(ICS1.UserDefined.After, 2116 ICS2.UserDefined.After); 2117 } 2118 2119 return ImplicitConversionSequence::Indistinguishable; 2120} 2121 2122static bool hasSimilarType(ASTContext &Context, QualType T1, QualType T2) { 2123 while (Context.UnwrapSimilarPointerTypes(T1, T2)) { 2124 Qualifiers Quals; 2125 T1 = Context.getUnqualifiedArrayType(T1, Quals); 2126 T2 = Context.getUnqualifiedArrayType(T2, Quals); 2127 } 2128 2129 return Context.hasSameUnqualifiedType(T1, T2); 2130} 2131 2132// Per 13.3.3.2p3, compare the given standard conversion sequences to 2133// determine if one is a proper subset of the other. 2134static ImplicitConversionSequence::CompareKind 2135compareStandardConversionSubsets(ASTContext &Context, 2136 const StandardConversionSequence& SCS1, 2137 const StandardConversionSequence& SCS2) { 2138 ImplicitConversionSequence::CompareKind Result 2139 = ImplicitConversionSequence::Indistinguishable; 2140 2141 // the identity conversion sequence is considered to be a subsequence of 2142 // any non-identity conversion sequence 2143 if (SCS1.ReferenceBinding == SCS2.ReferenceBinding) { 2144 if (SCS1.isIdentityConversion() && !SCS2.isIdentityConversion()) 2145 return ImplicitConversionSequence::Better; 2146 else if (!SCS1.isIdentityConversion() && SCS2.isIdentityConversion()) 2147 return ImplicitConversionSequence::Worse; 2148 } 2149 2150 if (SCS1.Second != SCS2.Second) { 2151 if (SCS1.Second == ICK_Identity) 2152 Result = ImplicitConversionSequence::Better; 2153 else if (SCS2.Second == ICK_Identity) 2154 Result = ImplicitConversionSequence::Worse; 2155 else 2156 return ImplicitConversionSequence::Indistinguishable; 2157 } else if (!hasSimilarType(Context, SCS1.getToType(1), SCS2.getToType(1))) 2158 return ImplicitConversionSequence::Indistinguishable; 2159 2160 if (SCS1.Third == SCS2.Third) { 2161 return Context.hasSameType(SCS1.getToType(2), SCS2.getToType(2))? Result 2162 : ImplicitConversionSequence::Indistinguishable; 2163 } 2164 2165 if (SCS1.Third == ICK_Identity) 2166 return Result == ImplicitConversionSequence::Worse 2167 ? ImplicitConversionSequence::Indistinguishable 2168 : ImplicitConversionSequence::Better; 2169 2170 if (SCS2.Third == ICK_Identity) 2171 return Result == ImplicitConversionSequence::Better 2172 ? ImplicitConversionSequence::Indistinguishable 2173 : ImplicitConversionSequence::Worse; 2174 2175 return ImplicitConversionSequence::Indistinguishable; 2176} 2177 2178/// CompareStandardConversionSequences - Compare two standard 2179/// conversion sequences to determine whether one is better than the 2180/// other or if they are indistinguishable (C++ 13.3.3.2p3). 2181ImplicitConversionSequence::CompareKind 2182Sema::CompareStandardConversionSequences(const StandardConversionSequence& SCS1, 2183 const StandardConversionSequence& SCS2) 2184{ 2185 // Standard conversion sequence S1 is a better conversion sequence 2186 // than standard conversion sequence S2 if (C++ 13.3.3.2p3): 2187 2188 // -- S1 is a proper subsequence of S2 (comparing the conversion 2189 // sequences in the canonical form defined by 13.3.3.1.1, 2190 // excluding any Lvalue Transformation; the identity conversion 2191 // sequence is considered to be a subsequence of any 2192 // non-identity conversion sequence) or, if not that, 2193 if (ImplicitConversionSequence::CompareKind CK 2194 = compareStandardConversionSubsets(Context, SCS1, SCS2)) 2195 return CK; 2196 2197 // -- the rank of S1 is better than the rank of S2 (by the rules 2198 // defined below), or, if not that, 2199 ImplicitConversionRank Rank1 = SCS1.getRank(); 2200 ImplicitConversionRank Rank2 = SCS2.getRank(); 2201 if (Rank1 < Rank2) 2202 return ImplicitConversionSequence::Better; 2203 else if (Rank2 < Rank1) 2204 return ImplicitConversionSequence::Worse; 2205 2206 // (C++ 13.3.3.2p4): Two conversion sequences with the same rank 2207 // are indistinguishable unless one of the following rules 2208 // applies: 2209 2210 // A conversion that is not a conversion of a pointer, or 2211 // pointer to member, to bool is better than another conversion 2212 // that is such a conversion. 2213 if (SCS1.isPointerConversionToBool() != SCS2.isPointerConversionToBool()) 2214 return SCS2.isPointerConversionToBool() 2215 ? ImplicitConversionSequence::Better 2216 : ImplicitConversionSequence::Worse; 2217 2218 // C++ [over.ics.rank]p4b2: 2219 // 2220 // If class B is derived directly or indirectly from class A, 2221 // conversion of B* to A* is better than conversion of B* to 2222 // void*, and conversion of A* to void* is better than conversion 2223 // of B* to void*. 2224 bool SCS1ConvertsToVoid 2225 = SCS1.isPointerConversionToVoidPointer(Context); 2226 bool SCS2ConvertsToVoid 2227 = SCS2.isPointerConversionToVoidPointer(Context); 2228 if (SCS1ConvertsToVoid != SCS2ConvertsToVoid) { 2229 // Exactly one of the conversion sequences is a conversion to 2230 // a void pointer; it's the worse conversion. 2231 return SCS2ConvertsToVoid ? ImplicitConversionSequence::Better 2232 : ImplicitConversionSequence::Worse; 2233 } else if (!SCS1ConvertsToVoid && !SCS2ConvertsToVoid) { 2234 // Neither conversion sequence converts to a void pointer; compare 2235 // their derived-to-base conversions. 2236 if (ImplicitConversionSequence::CompareKind DerivedCK 2237 = CompareDerivedToBaseConversions(SCS1, SCS2)) 2238 return DerivedCK; 2239 } else if (SCS1ConvertsToVoid && SCS2ConvertsToVoid) { 2240 // Both conversion sequences are conversions to void 2241 // pointers. Compare the source types to determine if there's an 2242 // inheritance relationship in their sources. 2243 QualType FromType1 = SCS1.getFromType(); 2244 QualType FromType2 = SCS2.getFromType(); 2245 2246 // Adjust the types we're converting from via the array-to-pointer 2247 // conversion, if we need to. 2248 if (SCS1.First == ICK_Array_To_Pointer) 2249 FromType1 = Context.getArrayDecayedType(FromType1); 2250 if (SCS2.First == ICK_Array_To_Pointer) 2251 FromType2 = Context.getArrayDecayedType(FromType2); 2252 2253 QualType FromPointee1 2254 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2255 QualType FromPointee2 2256 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2257 2258 if (IsDerivedFrom(FromPointee2, FromPointee1)) 2259 return ImplicitConversionSequence::Better; 2260 else if (IsDerivedFrom(FromPointee1, FromPointee2)) 2261 return ImplicitConversionSequence::Worse; 2262 2263 // Objective-C++: If one interface is more specific than the 2264 // other, it is the better one. 2265 const ObjCObjectType* FromIface1 = FromPointee1->getAs<ObjCObjectType>(); 2266 const ObjCObjectType* FromIface2 = FromPointee2->getAs<ObjCObjectType>(); 2267 if (FromIface1 && FromIface1) { 2268 if (Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 2269 return ImplicitConversionSequence::Better; 2270 else if (Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 2271 return ImplicitConversionSequence::Worse; 2272 } 2273 } 2274 2275 // Compare based on qualification conversions (C++ 13.3.3.2p3, 2276 // bullet 3). 2277 if (ImplicitConversionSequence::CompareKind QualCK 2278 = CompareQualificationConversions(SCS1, SCS2)) 2279 return QualCK; 2280 2281 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding) { 2282 // C++0x [over.ics.rank]p3b4: 2283 // -- S1 and S2 are reference bindings (8.5.3) and neither refers to an 2284 // implicit object parameter of a non-static member function declared 2285 // without a ref-qualifier, and S1 binds an rvalue reference to an 2286 // rvalue and S2 binds an lvalue reference. 2287 // FIXME: We don't know if we're dealing with the implicit object parameter, 2288 // or if the member function in this case has a ref qualifier. 2289 // (Of course, we don't have ref qualifiers yet.) 2290 if (SCS1.RRefBinding != SCS2.RRefBinding) 2291 return SCS1.RRefBinding ? ImplicitConversionSequence::Better 2292 : ImplicitConversionSequence::Worse; 2293 2294 // C++ [over.ics.rank]p3b4: 2295 // -- S1 and S2 are reference bindings (8.5.3), and the types to 2296 // which the references refer are the same type except for 2297 // top-level cv-qualifiers, and the type to which the reference 2298 // initialized by S2 refers is more cv-qualified than the type 2299 // to which the reference initialized by S1 refers. 2300 QualType T1 = SCS1.getToType(2); 2301 QualType T2 = SCS2.getToType(2); 2302 T1 = Context.getCanonicalType(T1); 2303 T2 = Context.getCanonicalType(T2); 2304 Qualifiers T1Quals, T2Quals; 2305 QualType UnqualT1 = Context.getUnqualifiedArrayType(T1, T1Quals); 2306 QualType UnqualT2 = Context.getUnqualifiedArrayType(T2, T2Quals); 2307 if (UnqualT1 == UnqualT2) { 2308 // If the type is an array type, promote the element qualifiers to the type 2309 // for comparison. 2310 if (isa<ArrayType>(T1) && T1Quals) 2311 T1 = Context.getQualifiedType(UnqualT1, T1Quals); 2312 if (isa<ArrayType>(T2) && T2Quals) 2313 T2 = Context.getQualifiedType(UnqualT2, T2Quals); 2314 if (T2.isMoreQualifiedThan(T1)) 2315 return ImplicitConversionSequence::Better; 2316 else if (T1.isMoreQualifiedThan(T2)) 2317 return ImplicitConversionSequence::Worse; 2318 } 2319 } 2320 2321 return ImplicitConversionSequence::Indistinguishable; 2322} 2323 2324/// CompareQualificationConversions - Compares two standard conversion 2325/// sequences to determine whether they can be ranked based on their 2326/// qualification conversions (C++ 13.3.3.2p3 bullet 3). 2327ImplicitConversionSequence::CompareKind 2328Sema::CompareQualificationConversions(const StandardConversionSequence& SCS1, 2329 const StandardConversionSequence& SCS2) { 2330 // C++ 13.3.3.2p3: 2331 // -- S1 and S2 differ only in their qualification conversion and 2332 // yield similar types T1 and T2 (C++ 4.4), respectively, and the 2333 // cv-qualification signature of type T1 is a proper subset of 2334 // the cv-qualification signature of type T2, and S1 is not the 2335 // deprecated string literal array-to-pointer conversion (4.2). 2336 if (SCS1.First != SCS2.First || SCS1.Second != SCS2.Second || 2337 SCS1.Third != SCS2.Third || SCS1.Third != ICK_Qualification) 2338 return ImplicitConversionSequence::Indistinguishable; 2339 2340 // FIXME: the example in the standard doesn't use a qualification 2341 // conversion (!) 2342 QualType T1 = SCS1.getToType(2); 2343 QualType T2 = SCS2.getToType(2); 2344 T1 = Context.getCanonicalType(T1); 2345 T2 = Context.getCanonicalType(T2); 2346 Qualifiers T1Quals, T2Quals; 2347 QualType UnqualT1 = Context.getUnqualifiedArrayType(T1, T1Quals); 2348 QualType UnqualT2 = Context.getUnqualifiedArrayType(T2, T2Quals); 2349 2350 // If the types are the same, we won't learn anything by unwrapped 2351 // them. 2352 if (UnqualT1 == UnqualT2) 2353 return ImplicitConversionSequence::Indistinguishable; 2354 2355 // If the type is an array type, promote the element qualifiers to the type 2356 // for comparison. 2357 if (isa<ArrayType>(T1) && T1Quals) 2358 T1 = Context.getQualifiedType(UnqualT1, T1Quals); 2359 if (isa<ArrayType>(T2) && T2Quals) 2360 T2 = Context.getQualifiedType(UnqualT2, T2Quals); 2361 2362 ImplicitConversionSequence::CompareKind Result 2363 = ImplicitConversionSequence::Indistinguishable; 2364 while (Context.UnwrapSimilarPointerTypes(T1, T2)) { 2365 // Within each iteration of the loop, we check the qualifiers to 2366 // determine if this still looks like a qualification 2367 // conversion. Then, if all is well, we unwrap one more level of 2368 // pointers or pointers-to-members and do it all again 2369 // until there are no more pointers or pointers-to-members left 2370 // to unwrap. This essentially mimics what 2371 // IsQualificationConversion does, but here we're checking for a 2372 // strict subset of qualifiers. 2373 if (T1.getCVRQualifiers() == T2.getCVRQualifiers()) 2374 // The qualifiers are the same, so this doesn't tell us anything 2375 // about how the sequences rank. 2376 ; 2377 else if (T2.isMoreQualifiedThan(T1)) { 2378 // T1 has fewer qualifiers, so it could be the better sequence. 2379 if (Result == ImplicitConversionSequence::Worse) 2380 // Neither has qualifiers that are a subset of the other's 2381 // qualifiers. 2382 return ImplicitConversionSequence::Indistinguishable; 2383 2384 Result = ImplicitConversionSequence::Better; 2385 } else if (T1.isMoreQualifiedThan(T2)) { 2386 // T2 has fewer qualifiers, so it could be the better sequence. 2387 if (Result == ImplicitConversionSequence::Better) 2388 // Neither has qualifiers that are a subset of the other's 2389 // qualifiers. 2390 return ImplicitConversionSequence::Indistinguishable; 2391 2392 Result = ImplicitConversionSequence::Worse; 2393 } else { 2394 // Qualifiers are disjoint. 2395 return ImplicitConversionSequence::Indistinguishable; 2396 } 2397 2398 // If the types after this point are equivalent, we're done. 2399 if (Context.hasSameUnqualifiedType(T1, T2)) 2400 break; 2401 } 2402 2403 // Check that the winning standard conversion sequence isn't using 2404 // the deprecated string literal array to pointer conversion. 2405 switch (Result) { 2406 case ImplicitConversionSequence::Better: 2407 if (SCS1.DeprecatedStringLiteralToCharPtr) 2408 Result = ImplicitConversionSequence::Indistinguishable; 2409 break; 2410 2411 case ImplicitConversionSequence::Indistinguishable: 2412 break; 2413 2414 case ImplicitConversionSequence::Worse: 2415 if (SCS2.DeprecatedStringLiteralToCharPtr) 2416 Result = ImplicitConversionSequence::Indistinguishable; 2417 break; 2418 } 2419 2420 return Result; 2421} 2422 2423/// CompareDerivedToBaseConversions - Compares two standard conversion 2424/// sequences to determine whether they can be ranked based on their 2425/// various kinds of derived-to-base conversions (C++ 2426/// [over.ics.rank]p4b3). As part of these checks, we also look at 2427/// conversions between Objective-C interface types. 2428ImplicitConversionSequence::CompareKind 2429Sema::CompareDerivedToBaseConversions(const StandardConversionSequence& SCS1, 2430 const StandardConversionSequence& SCS2) { 2431 QualType FromType1 = SCS1.getFromType(); 2432 QualType ToType1 = SCS1.getToType(1); 2433 QualType FromType2 = SCS2.getFromType(); 2434 QualType ToType2 = SCS2.getToType(1); 2435 2436 // Adjust the types we're converting from via the array-to-pointer 2437 // conversion, if we need to. 2438 if (SCS1.First == ICK_Array_To_Pointer) 2439 FromType1 = Context.getArrayDecayedType(FromType1); 2440 if (SCS2.First == ICK_Array_To_Pointer) 2441 FromType2 = Context.getArrayDecayedType(FromType2); 2442 2443 // Canonicalize all of the types. 2444 FromType1 = Context.getCanonicalType(FromType1); 2445 ToType1 = Context.getCanonicalType(ToType1); 2446 FromType2 = Context.getCanonicalType(FromType2); 2447 ToType2 = Context.getCanonicalType(ToType2); 2448 2449 // C++ [over.ics.rank]p4b3: 2450 // 2451 // If class B is derived directly or indirectly from class A and 2452 // class C is derived directly or indirectly from B, 2453 // 2454 // For Objective-C, we let A, B, and C also be Objective-C 2455 // interfaces. 2456 2457 // Compare based on pointer conversions. 2458 if (SCS1.Second == ICK_Pointer_Conversion && 2459 SCS2.Second == ICK_Pointer_Conversion && 2460 /*FIXME: Remove if Objective-C id conversions get their own rank*/ 2461 FromType1->isPointerType() && FromType2->isPointerType() && 2462 ToType1->isPointerType() && ToType2->isPointerType()) { 2463 QualType FromPointee1 2464 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2465 QualType ToPointee1 2466 = ToType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2467 QualType FromPointee2 2468 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2469 QualType ToPointee2 2470 = ToType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2471 2472 const ObjCObjectType* FromIface1 = FromPointee1->getAs<ObjCObjectType>(); 2473 const ObjCObjectType* FromIface2 = FromPointee2->getAs<ObjCObjectType>(); 2474 const ObjCObjectType* ToIface1 = ToPointee1->getAs<ObjCObjectType>(); 2475 const ObjCObjectType* ToIface2 = ToPointee2->getAs<ObjCObjectType>(); 2476 2477 // -- conversion of C* to B* is better than conversion of C* to A*, 2478 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 2479 if (IsDerivedFrom(ToPointee1, ToPointee2)) 2480 return ImplicitConversionSequence::Better; 2481 else if (IsDerivedFrom(ToPointee2, ToPointee1)) 2482 return ImplicitConversionSequence::Worse; 2483 2484 if (ToIface1 && ToIface2) { 2485 if (Context.canAssignObjCInterfaces(ToIface2, ToIface1)) 2486 return ImplicitConversionSequence::Better; 2487 else if (Context.canAssignObjCInterfaces(ToIface1, ToIface2)) 2488 return ImplicitConversionSequence::Worse; 2489 } 2490 } 2491 2492 // -- conversion of B* to A* is better than conversion of C* to A*, 2493 if (FromPointee1 != FromPointee2 && ToPointee1 == ToPointee2) { 2494 if (IsDerivedFrom(FromPointee2, FromPointee1)) 2495 return ImplicitConversionSequence::Better; 2496 else if (IsDerivedFrom(FromPointee1, FromPointee2)) 2497 return ImplicitConversionSequence::Worse; 2498 2499 if (FromIface1 && FromIface2) { 2500 if (Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 2501 return ImplicitConversionSequence::Better; 2502 else if (Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 2503 return ImplicitConversionSequence::Worse; 2504 } 2505 } 2506 } 2507 2508 // Ranking of member-pointer types. 2509 if (SCS1.Second == ICK_Pointer_Member && SCS2.Second == ICK_Pointer_Member && 2510 FromType1->isMemberPointerType() && FromType2->isMemberPointerType() && 2511 ToType1->isMemberPointerType() && ToType2->isMemberPointerType()) { 2512 const MemberPointerType * FromMemPointer1 = 2513 FromType1->getAs<MemberPointerType>(); 2514 const MemberPointerType * ToMemPointer1 = 2515 ToType1->getAs<MemberPointerType>(); 2516 const MemberPointerType * FromMemPointer2 = 2517 FromType2->getAs<MemberPointerType>(); 2518 const MemberPointerType * ToMemPointer2 = 2519 ToType2->getAs<MemberPointerType>(); 2520 const Type *FromPointeeType1 = FromMemPointer1->getClass(); 2521 const Type *ToPointeeType1 = ToMemPointer1->getClass(); 2522 const Type *FromPointeeType2 = FromMemPointer2->getClass(); 2523 const Type *ToPointeeType2 = ToMemPointer2->getClass(); 2524 QualType FromPointee1 = QualType(FromPointeeType1, 0).getUnqualifiedType(); 2525 QualType ToPointee1 = QualType(ToPointeeType1, 0).getUnqualifiedType(); 2526 QualType FromPointee2 = QualType(FromPointeeType2, 0).getUnqualifiedType(); 2527 QualType ToPointee2 = QualType(ToPointeeType2, 0).getUnqualifiedType(); 2528 // conversion of A::* to B::* is better than conversion of A::* to C::*, 2529 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 2530 if (IsDerivedFrom(ToPointee1, ToPointee2)) 2531 return ImplicitConversionSequence::Worse; 2532 else if (IsDerivedFrom(ToPointee2, ToPointee1)) 2533 return ImplicitConversionSequence::Better; 2534 } 2535 // conversion of B::* to C::* is better than conversion of A::* to C::* 2536 if (ToPointee1 == ToPointee2 && FromPointee1 != FromPointee2) { 2537 if (IsDerivedFrom(FromPointee1, FromPointee2)) 2538 return ImplicitConversionSequence::Better; 2539 else if (IsDerivedFrom(FromPointee2, FromPointee1)) 2540 return ImplicitConversionSequence::Worse; 2541 } 2542 } 2543 2544 if (SCS1.Second == ICK_Derived_To_Base) { 2545 // -- conversion of C to B is better than conversion of C to A, 2546 // -- binding of an expression of type C to a reference of type 2547 // B& is better than binding an expression of type C to a 2548 // reference of type A&, 2549 if (Context.hasSameUnqualifiedType(FromType1, FromType2) && 2550 !Context.hasSameUnqualifiedType(ToType1, ToType2)) { 2551 if (IsDerivedFrom(ToType1, ToType2)) 2552 return ImplicitConversionSequence::Better; 2553 else if (IsDerivedFrom(ToType2, ToType1)) 2554 return ImplicitConversionSequence::Worse; 2555 } 2556 2557 // -- conversion of B to A is better than conversion of C to A. 2558 // -- binding of an expression of type B to a reference of type 2559 // A& is better than binding an expression of type C to a 2560 // reference of type A&, 2561 if (!Context.hasSameUnqualifiedType(FromType1, FromType2) && 2562 Context.hasSameUnqualifiedType(ToType1, ToType2)) { 2563 if (IsDerivedFrom(FromType2, FromType1)) 2564 return ImplicitConversionSequence::Better; 2565 else if (IsDerivedFrom(FromType1, FromType2)) 2566 return ImplicitConversionSequence::Worse; 2567 } 2568 } 2569 2570 return ImplicitConversionSequence::Indistinguishable; 2571} 2572 2573/// CompareReferenceRelationship - Compare the two types T1 and T2 to 2574/// determine whether they are reference-related, 2575/// reference-compatible, reference-compatible with added 2576/// qualification, or incompatible, for use in C++ initialization by 2577/// reference (C++ [dcl.ref.init]p4). Neither type can be a reference 2578/// type, and the first type (T1) is the pointee type of the reference 2579/// type being initialized. 2580Sema::ReferenceCompareResult 2581Sema::CompareReferenceRelationship(SourceLocation Loc, 2582 QualType OrigT1, QualType OrigT2, 2583 bool &DerivedToBase, 2584 bool &ObjCConversion) { 2585 assert(!OrigT1->isReferenceType() && 2586 "T1 must be the pointee type of the reference type"); 2587 assert(!OrigT2->isReferenceType() && "T2 cannot be a reference type"); 2588 2589 QualType T1 = Context.getCanonicalType(OrigT1); 2590 QualType T2 = Context.getCanonicalType(OrigT2); 2591 Qualifiers T1Quals, T2Quals; 2592 QualType UnqualT1 = Context.getUnqualifiedArrayType(T1, T1Quals); 2593 QualType UnqualT2 = Context.getUnqualifiedArrayType(T2, T2Quals); 2594 2595 // C++ [dcl.init.ref]p4: 2596 // Given types "cv1 T1" and "cv2 T2," "cv1 T1" is 2597 // reference-related to "cv2 T2" if T1 is the same type as T2, or 2598 // T1 is a base class of T2. 2599 DerivedToBase = false; 2600 ObjCConversion = false; 2601 if (UnqualT1 == UnqualT2) { 2602 // Nothing to do. 2603 } else if (!RequireCompleteType(Loc, OrigT2, PDiag()) && 2604 IsDerivedFrom(UnqualT2, UnqualT1)) 2605 DerivedToBase = true; 2606 else if (UnqualT1->isObjCObjectOrInterfaceType() && 2607 UnqualT2->isObjCObjectOrInterfaceType() && 2608 Context.canBindObjCObjectType(UnqualT1, UnqualT2)) 2609 ObjCConversion = true; 2610 else 2611 return Ref_Incompatible; 2612 2613 // At this point, we know that T1 and T2 are reference-related (at 2614 // least). 2615 2616 // If the type is an array type, promote the element qualifiers to the type 2617 // for comparison. 2618 if (isa<ArrayType>(T1) && T1Quals) 2619 T1 = Context.getQualifiedType(UnqualT1, T1Quals); 2620 if (isa<ArrayType>(T2) && T2Quals) 2621 T2 = Context.getQualifiedType(UnqualT2, T2Quals); 2622 2623 // C++ [dcl.init.ref]p4: 2624 // "cv1 T1" is reference-compatible with "cv2 T2" if T1 is 2625 // reference-related to T2 and cv1 is the same cv-qualification 2626 // as, or greater cv-qualification than, cv2. For purposes of 2627 // overload resolution, cases for which cv1 is greater 2628 // cv-qualification than cv2 are identified as 2629 // reference-compatible with added qualification (see 13.3.3.2). 2630 if (T1Quals.getCVRQualifiers() == T2Quals.getCVRQualifiers()) 2631 return Ref_Compatible; 2632 else if (T1.isMoreQualifiedThan(T2)) 2633 return Ref_Compatible_With_Added_Qualification; 2634 else 2635 return Ref_Related; 2636} 2637 2638/// \brief Look for a user-defined conversion to an value reference-compatible 2639/// with DeclType. Return true if something definite is found. 2640static bool 2641FindConversionForRefInit(Sema &S, ImplicitConversionSequence &ICS, 2642 QualType DeclType, SourceLocation DeclLoc, 2643 Expr *Init, QualType T2, bool AllowRvalues, 2644 bool AllowExplicit) { 2645 assert(T2->isRecordType() && "Can only find conversions of record types."); 2646 CXXRecordDecl *T2RecordDecl 2647 = dyn_cast<CXXRecordDecl>(T2->getAs<RecordType>()->getDecl()); 2648 2649 QualType ToType 2650 = AllowRvalues? DeclType->getAs<ReferenceType>()->getPointeeType() 2651 : DeclType; 2652 2653 OverloadCandidateSet CandidateSet(DeclLoc); 2654 const UnresolvedSetImpl *Conversions 2655 = T2RecordDecl->getVisibleConversionFunctions(); 2656 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 2657 E = Conversions->end(); I != E; ++I) { 2658 NamedDecl *D = *I; 2659 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(D->getDeclContext()); 2660 if (isa<UsingShadowDecl>(D)) 2661 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 2662 2663 FunctionTemplateDecl *ConvTemplate 2664 = dyn_cast<FunctionTemplateDecl>(D); 2665 CXXConversionDecl *Conv; 2666 if (ConvTemplate) 2667 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 2668 else 2669 Conv = cast<CXXConversionDecl>(D); 2670 2671 // If this is an explicit conversion, and we're not allowed to consider 2672 // explicit conversions, skip it. 2673 if (!AllowExplicit && Conv->isExplicit()) 2674 continue; 2675 2676 if (AllowRvalues) { 2677 bool DerivedToBase = false; 2678 bool ObjCConversion = false; 2679 if (!ConvTemplate && 2680 S.CompareReferenceRelationship(DeclLoc, 2681 Conv->getConversionType().getNonReferenceType().getUnqualifiedType(), 2682 DeclType.getNonReferenceType().getUnqualifiedType(), 2683 DerivedToBase, ObjCConversion) 2684 == Sema::Ref_Incompatible) 2685 continue; 2686 } else { 2687 // If the conversion function doesn't return a reference type, 2688 // it can't be considered for this conversion. An rvalue reference 2689 // is only acceptable if its referencee is a function type. 2690 2691 const ReferenceType *RefType = 2692 Conv->getConversionType()->getAs<ReferenceType>(); 2693 if (!RefType || 2694 (!RefType->isLValueReferenceType() && 2695 !RefType->getPointeeType()->isFunctionType())) 2696 continue; 2697 } 2698 2699 if (ConvTemplate) 2700 S.AddTemplateConversionCandidate(ConvTemplate, I.getPair(), ActingDC, 2701 Init, ToType, CandidateSet); 2702 else 2703 S.AddConversionCandidate(Conv, I.getPair(), ActingDC, Init, 2704 ToType, CandidateSet); 2705 } 2706 2707 OverloadCandidateSet::iterator Best; 2708 switch (S.BestViableFunction(CandidateSet, DeclLoc, Best)) { 2709 case OR_Success: 2710 // C++ [over.ics.ref]p1: 2711 // 2712 // [...] If the parameter binds directly to the result of 2713 // applying a conversion function to the argument 2714 // expression, the implicit conversion sequence is a 2715 // user-defined conversion sequence (13.3.3.1.2), with the 2716 // second standard conversion sequence either an identity 2717 // conversion or, if the conversion function returns an 2718 // entity of a type that is a derived class of the parameter 2719 // type, a derived-to-base Conversion. 2720 if (!Best->FinalConversion.DirectBinding) 2721 return false; 2722 2723 ICS.setUserDefined(); 2724 ICS.UserDefined.Before = Best->Conversions[0].Standard; 2725 ICS.UserDefined.After = Best->FinalConversion; 2726 ICS.UserDefined.ConversionFunction = Best->Function; 2727 ICS.UserDefined.EllipsisConversion = false; 2728 assert(ICS.UserDefined.After.ReferenceBinding && 2729 ICS.UserDefined.After.DirectBinding && 2730 "Expected a direct reference binding!"); 2731 return true; 2732 2733 case OR_Ambiguous: 2734 ICS.setAmbiguous(); 2735 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 2736 Cand != CandidateSet.end(); ++Cand) 2737 if (Cand->Viable) 2738 ICS.Ambiguous.addConversion(Cand->Function); 2739 return true; 2740 2741 case OR_No_Viable_Function: 2742 case OR_Deleted: 2743 // There was no suitable conversion, or we found a deleted 2744 // conversion; continue with other checks. 2745 return false; 2746 } 2747 2748 return false; 2749} 2750 2751/// \brief Compute an implicit conversion sequence for reference 2752/// initialization. 2753static ImplicitConversionSequence 2754TryReferenceInit(Sema &S, Expr *&Init, QualType DeclType, 2755 SourceLocation DeclLoc, 2756 bool SuppressUserConversions, 2757 bool AllowExplicit) { 2758 assert(DeclType->isReferenceType() && "Reference init needs a reference"); 2759 2760 // Most paths end in a failed conversion. 2761 ImplicitConversionSequence ICS; 2762 ICS.setBad(BadConversionSequence::no_conversion, Init, DeclType); 2763 2764 QualType T1 = DeclType->getAs<ReferenceType>()->getPointeeType(); 2765 QualType T2 = Init->getType(); 2766 2767 // If the initializer is the address of an overloaded function, try 2768 // to resolve the overloaded function. If all goes well, T2 is the 2769 // type of the resulting function. 2770 if (S.Context.getCanonicalType(T2) == S.Context.OverloadTy) { 2771 DeclAccessPair Found; 2772 if (FunctionDecl *Fn = S.ResolveAddressOfOverloadedFunction(Init, DeclType, 2773 false, Found)) 2774 T2 = Fn->getType(); 2775 } 2776 2777 // Compute some basic properties of the types and the initializer. 2778 bool isRValRef = DeclType->isRValueReferenceType(); 2779 bool DerivedToBase = false; 2780 bool ObjCConversion = false; 2781 Expr::Classification InitCategory = Init->Classify(S.Context); 2782 Sema::ReferenceCompareResult RefRelationship 2783 = S.CompareReferenceRelationship(DeclLoc, T1, T2, DerivedToBase, 2784 ObjCConversion); 2785 2786 2787 // C++0x [dcl.init.ref]p5: 2788 // A reference to type "cv1 T1" is initialized by an expression 2789 // of type "cv2 T2" as follows: 2790 2791 // -- If reference is an lvalue reference and the initializer expression 2792 // The next bullet point (T1 is a function) is pretty much equivalent to this 2793 // one, so it's handled here. 2794 if (!isRValRef || T1->isFunctionType()) { 2795 // -- is an lvalue (but is not a bit-field), and "cv1 T1" is 2796 // reference-compatible with "cv2 T2," or 2797 // 2798 // Per C++ [over.ics.ref]p4, we don't check the bit-field property here. 2799 if (InitCategory.isLValue() && 2800 RefRelationship >= Sema::Ref_Compatible_With_Added_Qualification) { 2801 // C++ [over.ics.ref]p1: 2802 // When a parameter of reference type binds directly (8.5.3) 2803 // to an argument expression, the implicit conversion sequence 2804 // is the identity conversion, unless the argument expression 2805 // has a type that is a derived class of the parameter type, 2806 // in which case the implicit conversion sequence is a 2807 // derived-to-base Conversion (13.3.3.1). 2808 ICS.setStandard(); 2809 ICS.Standard.First = ICK_Identity; 2810 ICS.Standard.Second = DerivedToBase? ICK_Derived_To_Base 2811 : ObjCConversion? ICK_Compatible_Conversion 2812 : ICK_Identity; 2813 ICS.Standard.Third = ICK_Identity; 2814 ICS.Standard.FromTypePtr = T2.getAsOpaquePtr(); 2815 ICS.Standard.setToType(0, T2); 2816 ICS.Standard.setToType(1, T1); 2817 ICS.Standard.setToType(2, T1); 2818 ICS.Standard.ReferenceBinding = true; 2819 ICS.Standard.DirectBinding = true; 2820 ICS.Standard.RRefBinding = isRValRef; 2821 ICS.Standard.CopyConstructor = 0; 2822 2823 // Nothing more to do: the inaccessibility/ambiguity check for 2824 // derived-to-base conversions is suppressed when we're 2825 // computing the implicit conversion sequence (C++ 2826 // [over.best.ics]p2). 2827 return ICS; 2828 } 2829 2830 // -- has a class type (i.e., T2 is a class type), where T1 is 2831 // not reference-related to T2, and can be implicitly 2832 // converted to an lvalue of type "cv3 T3," where "cv1 T1" 2833 // is reference-compatible with "cv3 T3" 92) (this 2834 // conversion is selected by enumerating the applicable 2835 // conversion functions (13.3.1.6) and choosing the best 2836 // one through overload resolution (13.3)), 2837 if (!SuppressUserConversions && T2->isRecordType() && 2838 !S.RequireCompleteType(DeclLoc, T2, 0) && 2839 RefRelationship == Sema::Ref_Incompatible) { 2840 if (FindConversionForRefInit(S, ICS, DeclType, DeclLoc, 2841 Init, T2, /*AllowRvalues=*/false, 2842 AllowExplicit)) 2843 return ICS; 2844 } 2845 } 2846 2847 // -- Otherwise, the reference shall be an lvalue reference to a 2848 // non-volatile const type (i.e., cv1 shall be const), or the reference 2849 // shall be an rvalue reference and the initializer expression shall be 2850 // an rvalue or have a function type. 2851 // 2852 // We actually handle one oddity of C++ [over.ics.ref] at this 2853 // point, which is that, due to p2 (which short-circuits reference 2854 // binding by only attempting a simple conversion for non-direct 2855 // bindings) and p3's strange wording, we allow a const volatile 2856 // reference to bind to an rvalue. Hence the check for the presence 2857 // of "const" rather than checking for "const" being the only 2858 // qualifier. 2859 // This is also the point where rvalue references and lvalue inits no longer 2860 // go together. 2861 if ((!isRValRef && !T1.isConstQualified()) || 2862 (isRValRef && InitCategory.isLValue())) 2863 return ICS; 2864 2865 // -- If T1 is a function type, then 2866 // -- if T2 is the same type as T1, the reference is bound to the 2867 // initializer expression lvalue; 2868 // -- if T2 is a class type and the initializer expression can be 2869 // implicitly converted to an lvalue of type T1 [...], the 2870 // reference is bound to the function lvalue that is the result 2871 // of the conversion; 2872 // This is the same as for the lvalue case above, so it was handled there. 2873 // -- otherwise, the program is ill-formed. 2874 // This is the one difference to the lvalue case. 2875 if (T1->isFunctionType()) 2876 return ICS; 2877 2878 // -- Otherwise, if T2 is a class type and 2879 // -- the initializer expression is an rvalue and "cv1 T1" 2880 // is reference-compatible with "cv2 T2," or 2881 // 2882 // -- T1 is not reference-related to T2 and the initializer 2883 // expression can be implicitly converted to an rvalue 2884 // of type "cv3 T3" (this conversion is selected by 2885 // enumerating the applicable conversion functions 2886 // (13.3.1.6) and choosing the best one through overload 2887 // resolution (13.3)), 2888 // 2889 // then the reference is bound to the initializer 2890 // expression rvalue in the first case and to the object 2891 // that is the result of the conversion in the second case 2892 // (or, in either case, to the appropriate base class 2893 // subobject of the object). 2894 if (T2->isRecordType()) { 2895 // First case: "cv1 T1" is reference-compatible with "cv2 T2". This is a 2896 // direct binding in C++0x but not in C++03. 2897 if (InitCategory.isRValue() && 2898 RefRelationship >= Sema::Ref_Compatible_With_Added_Qualification) { 2899 ICS.setStandard(); 2900 ICS.Standard.First = ICK_Identity; 2901 ICS.Standard.Second = DerivedToBase? ICK_Derived_To_Base 2902 : ObjCConversion? ICK_Compatible_Conversion 2903 : ICK_Identity; 2904 ICS.Standard.Third = ICK_Identity; 2905 ICS.Standard.FromTypePtr = T2.getAsOpaquePtr(); 2906 ICS.Standard.setToType(0, T2); 2907 ICS.Standard.setToType(1, T1); 2908 ICS.Standard.setToType(2, T1); 2909 ICS.Standard.ReferenceBinding = true; 2910 ICS.Standard.DirectBinding = S.getLangOptions().CPlusPlus0x; 2911 ICS.Standard.RRefBinding = isRValRef; 2912 ICS.Standard.CopyConstructor = 0; 2913 return ICS; 2914 } 2915 2916 // Second case: not reference-related. 2917 if (RefRelationship == Sema::Ref_Incompatible && 2918 !S.RequireCompleteType(DeclLoc, T2, 0) && 2919 FindConversionForRefInit(S, ICS, DeclType, DeclLoc, 2920 Init, T2, /*AllowRvalues=*/true, 2921 AllowExplicit)) 2922 return ICS; 2923 } 2924 2925 // -- Otherwise, a temporary of type "cv1 T1" is created and 2926 // initialized from the initializer expression using the 2927 // rules for a non-reference copy initialization (8.5). The 2928 // reference is then bound to the temporary. If T1 is 2929 // reference-related to T2, cv1 must be the same 2930 // cv-qualification as, or greater cv-qualification than, 2931 // cv2; otherwise, the program is ill-formed. 2932 if (RefRelationship == Sema::Ref_Related) { 2933 // If cv1 == cv2 or cv1 is a greater cv-qualified than cv2, then 2934 // we would be reference-compatible or reference-compatible with 2935 // added qualification. But that wasn't the case, so the reference 2936 // initialization fails. 2937 return ICS; 2938 } 2939 2940 // If at least one of the types is a class type, the types are not 2941 // related, and we aren't allowed any user conversions, the 2942 // reference binding fails. This case is important for breaking 2943 // recursion, since TryImplicitConversion below will attempt to 2944 // create a temporary through the use of a copy constructor. 2945 if (SuppressUserConversions && RefRelationship == Sema::Ref_Incompatible && 2946 (T1->isRecordType() || T2->isRecordType())) 2947 return ICS; 2948 2949 // C++ [over.ics.ref]p2: 2950 // When a parameter of reference type is not bound directly to 2951 // an argument expression, the conversion sequence is the one 2952 // required to convert the argument expression to the 2953 // underlying type of the reference according to 2954 // 13.3.3.1. Conceptually, this conversion sequence corresponds 2955 // to copy-initializing a temporary of the underlying type with 2956 // the argument expression. Any difference in top-level 2957 // cv-qualification is subsumed by the initialization itself 2958 // and does not constitute a conversion. 2959 ICS = S.TryImplicitConversion(Init, T1, SuppressUserConversions, 2960 /*AllowExplicit=*/false, 2961 /*InOverloadResolution=*/false); 2962 2963 // Of course, that's still a reference binding. 2964 if (ICS.isStandard()) { 2965 ICS.Standard.ReferenceBinding = true; 2966 ICS.Standard.RRefBinding = isRValRef; 2967 } else if (ICS.isUserDefined()) { 2968 ICS.UserDefined.After.ReferenceBinding = true; 2969 ICS.UserDefined.After.RRefBinding = isRValRef; 2970 } 2971 return ICS; 2972} 2973 2974/// TryCopyInitialization - Try to copy-initialize a value of type 2975/// ToType from the expression From. Return the implicit conversion 2976/// sequence required to pass this argument, which may be a bad 2977/// conversion sequence (meaning that the argument cannot be passed to 2978/// a parameter of this type). If @p SuppressUserConversions, then we 2979/// do not permit any user-defined conversion sequences. 2980static ImplicitConversionSequence 2981TryCopyInitialization(Sema &S, Expr *From, QualType ToType, 2982 bool SuppressUserConversions, 2983 bool InOverloadResolution) { 2984 if (ToType->isReferenceType()) 2985 return TryReferenceInit(S, From, ToType, 2986 /*FIXME:*/From->getLocStart(), 2987 SuppressUserConversions, 2988 /*AllowExplicit=*/false); 2989 2990 return S.TryImplicitConversion(From, ToType, 2991 SuppressUserConversions, 2992 /*AllowExplicit=*/false, 2993 InOverloadResolution); 2994} 2995 2996/// TryObjectArgumentInitialization - Try to initialize the object 2997/// parameter of the given member function (@c Method) from the 2998/// expression @p From. 2999ImplicitConversionSequence 3000Sema::TryObjectArgumentInitialization(QualType OrigFromType, 3001 CXXMethodDecl *Method, 3002 CXXRecordDecl *ActingContext) { 3003 QualType ClassType = Context.getTypeDeclType(ActingContext); 3004 // [class.dtor]p2: A destructor can be invoked for a const, volatile or 3005 // const volatile object. 3006 unsigned Quals = isa<CXXDestructorDecl>(Method) ? 3007 Qualifiers::Const | Qualifiers::Volatile : Method->getTypeQualifiers(); 3008 QualType ImplicitParamType = Context.getCVRQualifiedType(ClassType, Quals); 3009 3010 // Set up the conversion sequence as a "bad" conversion, to allow us 3011 // to exit early. 3012 ImplicitConversionSequence ICS; 3013 3014 // We need to have an object of class type. 3015 QualType FromType = OrigFromType; 3016 if (const PointerType *PT = FromType->getAs<PointerType>()) 3017 FromType = PT->getPointeeType(); 3018 3019 assert(FromType->isRecordType()); 3020 3021 // The implicit object parameter is has the type "reference to cv X", 3022 // where X is the class of which the function is a member 3023 // (C++ [over.match.funcs]p4). However, when finding an implicit 3024 // conversion sequence for the argument, we are not allowed to 3025 // create temporaries or perform user-defined conversions 3026 // (C++ [over.match.funcs]p5). We perform a simplified version of 3027 // reference binding here, that allows class rvalues to bind to 3028 // non-constant references. 3029 3030 // First check the qualifiers. We don't care about lvalue-vs-rvalue 3031 // with the implicit object parameter (C++ [over.match.funcs]p5). 3032 QualType FromTypeCanon = Context.getCanonicalType(FromType); 3033 if (ImplicitParamType.getCVRQualifiers() 3034 != FromTypeCanon.getLocalCVRQualifiers() && 3035 !ImplicitParamType.isAtLeastAsQualifiedAs(FromTypeCanon)) { 3036 ICS.setBad(BadConversionSequence::bad_qualifiers, 3037 OrigFromType, ImplicitParamType); 3038 return ICS; 3039 } 3040 3041 // Check that we have either the same type or a derived type. It 3042 // affects the conversion rank. 3043 QualType ClassTypeCanon = Context.getCanonicalType(ClassType); 3044 ImplicitConversionKind SecondKind; 3045 if (ClassTypeCanon == FromTypeCanon.getLocalUnqualifiedType()) { 3046 SecondKind = ICK_Identity; 3047 } else if (IsDerivedFrom(FromType, ClassType)) 3048 SecondKind = ICK_Derived_To_Base; 3049 else { 3050 ICS.setBad(BadConversionSequence::unrelated_class, 3051 FromType, ImplicitParamType); 3052 return ICS; 3053 } 3054 3055 // Success. Mark this as a reference binding. 3056 ICS.setStandard(); 3057 ICS.Standard.setAsIdentityConversion(); 3058 ICS.Standard.Second = SecondKind; 3059 ICS.Standard.setFromType(FromType); 3060 ICS.Standard.setAllToTypes(ImplicitParamType); 3061 ICS.Standard.ReferenceBinding = true; 3062 ICS.Standard.DirectBinding = true; 3063 ICS.Standard.RRefBinding = false; 3064 return ICS; 3065} 3066 3067/// PerformObjectArgumentInitialization - Perform initialization of 3068/// the implicit object parameter for the given Method with the given 3069/// expression. 3070bool 3071Sema::PerformObjectArgumentInitialization(Expr *&From, 3072 NestedNameSpecifier *Qualifier, 3073 NamedDecl *FoundDecl, 3074 CXXMethodDecl *Method) { 3075 QualType FromRecordType, DestType; 3076 QualType ImplicitParamRecordType = 3077 Method->getThisType(Context)->getAs<PointerType>()->getPointeeType(); 3078 3079 if (const PointerType *PT = From->getType()->getAs<PointerType>()) { 3080 FromRecordType = PT->getPointeeType(); 3081 DestType = Method->getThisType(Context); 3082 } else { 3083 FromRecordType = From->getType(); 3084 DestType = ImplicitParamRecordType; 3085 } 3086 3087 // Note that we always use the true parent context when performing 3088 // the actual argument initialization. 3089 ImplicitConversionSequence ICS 3090 = TryObjectArgumentInitialization(From->getType(), Method, 3091 Method->getParent()); 3092 if (ICS.isBad()) 3093 return Diag(From->getSourceRange().getBegin(), 3094 diag::err_implicit_object_parameter_init) 3095 << ImplicitParamRecordType << FromRecordType << From->getSourceRange(); 3096 3097 if (ICS.Standard.Second == ICK_Derived_To_Base) 3098 return PerformObjectMemberConversion(From, Qualifier, FoundDecl, Method); 3099 3100 if (!Context.hasSameType(From->getType(), DestType)) 3101 ImpCastExprToType(From, DestType, CastExpr::CK_NoOp, 3102 From->getType()->isPointerType() ? 3103 ImplicitCastExpr::RValue : ImplicitCastExpr::LValue); 3104 return false; 3105} 3106 3107/// TryContextuallyConvertToBool - Attempt to contextually convert the 3108/// expression From to bool (C++0x [conv]p3). 3109ImplicitConversionSequence Sema::TryContextuallyConvertToBool(Expr *From) { 3110 // FIXME: This is pretty broken. 3111 return TryImplicitConversion(From, Context.BoolTy, 3112 // FIXME: Are these flags correct? 3113 /*SuppressUserConversions=*/false, 3114 /*AllowExplicit=*/true, 3115 /*InOverloadResolution=*/false); 3116} 3117 3118/// PerformContextuallyConvertToBool - Perform a contextual conversion 3119/// of the expression From to bool (C++0x [conv]p3). 3120bool Sema::PerformContextuallyConvertToBool(Expr *&From) { 3121 ImplicitConversionSequence ICS = TryContextuallyConvertToBool(From); 3122 if (!ICS.isBad()) 3123 return PerformImplicitConversion(From, Context.BoolTy, ICS, AA_Converting); 3124 3125 if (!DiagnoseMultipleUserDefinedConversion(From, Context.BoolTy)) 3126 return Diag(From->getSourceRange().getBegin(), 3127 diag::err_typecheck_bool_condition) 3128 << From->getType() << From->getSourceRange(); 3129 return true; 3130} 3131 3132/// TryContextuallyConvertToObjCId - Attempt to contextually convert the 3133/// expression From to 'id'. 3134ImplicitConversionSequence Sema::TryContextuallyConvertToObjCId(Expr *From) { 3135 QualType Ty = Context.getObjCIdType(); 3136 return TryImplicitConversion(From, Ty, 3137 // FIXME: Are these flags correct? 3138 /*SuppressUserConversions=*/false, 3139 /*AllowExplicit=*/true, 3140 /*InOverloadResolution=*/false); 3141} 3142 3143/// PerformContextuallyConvertToObjCId - Perform a contextual conversion 3144/// of the expression From to 'id'. 3145bool Sema::PerformContextuallyConvertToObjCId(Expr *&From) { 3146 QualType Ty = Context.getObjCIdType(); 3147 ImplicitConversionSequence ICS = TryContextuallyConvertToObjCId(From); 3148 if (!ICS.isBad()) 3149 return PerformImplicitConversion(From, Ty, ICS, AA_Converting); 3150 return true; 3151} 3152 3153/// \brief Attempt to convert the given expression to an integral or 3154/// enumeration type. 3155/// 3156/// This routine will attempt to convert an expression of class type to an 3157/// integral or enumeration type, if that class type only has a single 3158/// conversion to an integral or enumeration type. 3159/// 3160/// \param Loc The source location of the construct that requires the 3161/// conversion. 3162/// 3163/// \param FromE The expression we're converting from. 3164/// 3165/// \param NotIntDiag The diagnostic to be emitted if the expression does not 3166/// have integral or enumeration type. 3167/// 3168/// \param IncompleteDiag The diagnostic to be emitted if the expression has 3169/// incomplete class type. 3170/// 3171/// \param ExplicitConvDiag The diagnostic to be emitted if we're calling an 3172/// explicit conversion function (because no implicit conversion functions 3173/// were available). This is a recovery mode. 3174/// 3175/// \param ExplicitConvNote The note to be emitted with \p ExplicitConvDiag, 3176/// showing which conversion was picked. 3177/// 3178/// \param AmbigDiag The diagnostic to be emitted if there is more than one 3179/// conversion function that could convert to integral or enumeration type. 3180/// 3181/// \param AmbigNote The note to be emitted with \p AmbigDiag for each 3182/// usable conversion function. 3183/// 3184/// \param ConvDiag The diagnostic to be emitted if we are calling a conversion 3185/// function, which may be an extension in this case. 3186/// 3187/// \returns The expression, converted to an integral or enumeration type if 3188/// successful. 3189Sema::OwningExprResult 3190Sema::ConvertToIntegralOrEnumerationType(SourceLocation Loc, ExprArg FromE, 3191 const PartialDiagnostic &NotIntDiag, 3192 const PartialDiagnostic &IncompleteDiag, 3193 const PartialDiagnostic &ExplicitConvDiag, 3194 const PartialDiagnostic &ExplicitConvNote, 3195 const PartialDiagnostic &AmbigDiag, 3196 const PartialDiagnostic &AmbigNote, 3197 const PartialDiagnostic &ConvDiag) { 3198 Expr *From = static_cast<Expr *>(FromE.get()); 3199 3200 // We can't perform any more checking for type-dependent expressions. 3201 if (From->isTypeDependent()) 3202 return move(FromE); 3203 3204 // If the expression already has integral or enumeration type, we're golden. 3205 QualType T = From->getType(); 3206 if (T->isIntegralOrEnumerationType()) 3207 return move(FromE); 3208 3209 // FIXME: Check for missing '()' if T is a function type? 3210 3211 // If we don't have a class type in C++, there's no way we can get an 3212 // expression of integral or enumeration type. 3213 const RecordType *RecordTy = T->getAs<RecordType>(); 3214 if (!RecordTy || !getLangOptions().CPlusPlus) { 3215 Diag(Loc, NotIntDiag) 3216 << T << From->getSourceRange(); 3217 return move(FromE); 3218 } 3219 3220 // We must have a complete class type. 3221 if (RequireCompleteType(Loc, T, IncompleteDiag)) 3222 return move(FromE); 3223 3224 // Look for a conversion to an integral or enumeration type. 3225 UnresolvedSet<4> ViableConversions; 3226 UnresolvedSet<4> ExplicitConversions; 3227 const UnresolvedSetImpl *Conversions 3228 = cast<CXXRecordDecl>(RecordTy->getDecl())->getVisibleConversionFunctions(); 3229 3230 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 3231 E = Conversions->end(); 3232 I != E; 3233 ++I) { 3234 if (CXXConversionDecl *Conversion 3235 = dyn_cast<CXXConversionDecl>((*I)->getUnderlyingDecl())) 3236 if (Conversion->getConversionType().getNonReferenceType() 3237 ->isIntegralOrEnumerationType()) { 3238 if (Conversion->isExplicit()) 3239 ExplicitConversions.addDecl(I.getDecl(), I.getAccess()); 3240 else 3241 ViableConversions.addDecl(I.getDecl(), I.getAccess()); 3242 } 3243 } 3244 3245 switch (ViableConversions.size()) { 3246 case 0: 3247 if (ExplicitConversions.size() == 1) { 3248 DeclAccessPair Found = ExplicitConversions[0]; 3249 CXXConversionDecl *Conversion 3250 = cast<CXXConversionDecl>(Found->getUnderlyingDecl()); 3251 3252 // The user probably meant to invoke the given explicit 3253 // conversion; use it. 3254 QualType ConvTy 3255 = Conversion->getConversionType().getNonReferenceType(); 3256 std::string TypeStr; 3257 ConvTy.getAsStringInternal(TypeStr, Context.PrintingPolicy); 3258 3259 Diag(Loc, ExplicitConvDiag) 3260 << T << ConvTy 3261 << FixItHint::CreateInsertion(From->getLocStart(), 3262 "static_cast<" + TypeStr + ">(") 3263 << FixItHint::CreateInsertion(PP.getLocForEndOfToken(From->getLocEnd()), 3264 ")"); 3265 Diag(Conversion->getLocation(), ExplicitConvNote) 3266 << ConvTy->isEnumeralType() << ConvTy; 3267 3268 // If we aren't in a SFINAE context, build a call to the 3269 // explicit conversion function. 3270 if (isSFINAEContext()) 3271 return ExprError(); 3272 3273 CheckMemberOperatorAccess(From->getExprLoc(), From, 0, Found); 3274 From = BuildCXXMemberCallExpr(FromE.takeAs<Expr>(), Found, Conversion); 3275 FromE = Owned(From); 3276 } 3277 3278 // We'll complain below about a non-integral condition type. 3279 break; 3280 3281 case 1: { 3282 // Apply this conversion. 3283 DeclAccessPair Found = ViableConversions[0]; 3284 CheckMemberOperatorAccess(From->getExprLoc(), From, 0, Found); 3285 3286 CXXConversionDecl *Conversion 3287 = cast<CXXConversionDecl>(Found->getUnderlyingDecl()); 3288 QualType ConvTy 3289 = Conversion->getConversionType().getNonReferenceType(); 3290 if (ConvDiag.getDiagID()) { 3291 if (isSFINAEContext()) 3292 return ExprError(); 3293 3294 Diag(Loc, ConvDiag) 3295 << T << ConvTy->isEnumeralType() << ConvTy << From->getSourceRange(); 3296 } 3297 3298 From = BuildCXXMemberCallExpr(FromE.takeAs<Expr>(), Found, 3299 cast<CXXConversionDecl>(Found->getUnderlyingDecl())); 3300 FromE = Owned(From); 3301 break; 3302 } 3303 3304 default: 3305 Diag(Loc, AmbigDiag) 3306 << T << From->getSourceRange(); 3307 for (unsigned I = 0, N = ViableConversions.size(); I != N; ++I) { 3308 CXXConversionDecl *Conv 3309 = cast<CXXConversionDecl>(ViableConversions[I]->getUnderlyingDecl()); 3310 QualType ConvTy = Conv->getConversionType().getNonReferenceType(); 3311 Diag(Conv->getLocation(), AmbigNote) 3312 << ConvTy->isEnumeralType() << ConvTy; 3313 } 3314 return move(FromE); 3315 } 3316 3317 if (!From->getType()->isIntegralOrEnumerationType()) 3318 Diag(Loc, NotIntDiag) 3319 << From->getType() << From->getSourceRange(); 3320 3321 return move(FromE); 3322} 3323 3324/// AddOverloadCandidate - Adds the given function to the set of 3325/// candidate functions, using the given function call arguments. If 3326/// @p SuppressUserConversions, then don't allow user-defined 3327/// conversions via constructors or conversion operators. 3328/// 3329/// \para PartialOverloading true if we are performing "partial" overloading 3330/// based on an incomplete set of function arguments. This feature is used by 3331/// code completion. 3332void 3333Sema::AddOverloadCandidate(FunctionDecl *Function, 3334 DeclAccessPair FoundDecl, 3335 Expr **Args, unsigned NumArgs, 3336 OverloadCandidateSet& CandidateSet, 3337 bool SuppressUserConversions, 3338 bool PartialOverloading) { 3339 const FunctionProtoType* Proto 3340 = dyn_cast<FunctionProtoType>(Function->getType()->getAs<FunctionType>()); 3341 assert(Proto && "Functions without a prototype cannot be overloaded"); 3342 assert(!Function->getDescribedFunctionTemplate() && 3343 "Use AddTemplateOverloadCandidate for function templates"); 3344 3345 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Function)) { 3346 if (!isa<CXXConstructorDecl>(Method)) { 3347 // If we get here, it's because we're calling a member function 3348 // that is named without a member access expression (e.g., 3349 // "this->f") that was either written explicitly or created 3350 // implicitly. This can happen with a qualified call to a member 3351 // function, e.g., X::f(). We use an empty type for the implied 3352 // object argument (C++ [over.call.func]p3), and the acting context 3353 // is irrelevant. 3354 AddMethodCandidate(Method, FoundDecl, Method->getParent(), 3355 QualType(), Args, NumArgs, CandidateSet, 3356 SuppressUserConversions); 3357 return; 3358 } 3359 // We treat a constructor like a non-member function, since its object 3360 // argument doesn't participate in overload resolution. 3361 } 3362 3363 if (!CandidateSet.isNewCandidate(Function)) 3364 return; 3365 3366 // Overload resolution is always an unevaluated context. 3367 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 3368 3369 if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(Function)){ 3370 // C++ [class.copy]p3: 3371 // A member function template is never instantiated to perform the copy 3372 // of a class object to an object of its class type. 3373 QualType ClassType = Context.getTypeDeclType(Constructor->getParent()); 3374 if (NumArgs == 1 && 3375 Constructor->isCopyConstructorLikeSpecialization() && 3376 (Context.hasSameUnqualifiedType(ClassType, Args[0]->getType()) || 3377 IsDerivedFrom(Args[0]->getType(), ClassType))) 3378 return; 3379 } 3380 3381 // Add this candidate 3382 CandidateSet.push_back(OverloadCandidate()); 3383 OverloadCandidate& Candidate = CandidateSet.back(); 3384 Candidate.FoundDecl = FoundDecl; 3385 Candidate.Function = Function; 3386 Candidate.Viable = true; 3387 Candidate.IsSurrogate = false; 3388 Candidate.IgnoreObjectArgument = false; 3389 3390 unsigned NumArgsInProto = Proto->getNumArgs(); 3391 3392 // (C++ 13.3.2p2): A candidate function having fewer than m 3393 // parameters is viable only if it has an ellipsis in its parameter 3394 // list (8.3.5). 3395 if ((NumArgs + (PartialOverloading && NumArgs)) > NumArgsInProto && 3396 !Proto->isVariadic()) { 3397 Candidate.Viable = false; 3398 Candidate.FailureKind = ovl_fail_too_many_arguments; 3399 return; 3400 } 3401 3402 // (C++ 13.3.2p2): A candidate function having more than m parameters 3403 // is viable only if the (m+1)st parameter has a default argument 3404 // (8.3.6). For the purposes of overload resolution, the 3405 // parameter list is truncated on the right, so that there are 3406 // exactly m parameters. 3407 unsigned MinRequiredArgs = Function->getMinRequiredArguments(); 3408 if (NumArgs < MinRequiredArgs && !PartialOverloading) { 3409 // Not enough arguments. 3410 Candidate.Viable = false; 3411 Candidate.FailureKind = ovl_fail_too_few_arguments; 3412 return; 3413 } 3414 3415 // Determine the implicit conversion sequences for each of the 3416 // arguments. 3417 Candidate.Conversions.resize(NumArgs); 3418 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 3419 if (ArgIdx < NumArgsInProto) { 3420 // (C++ 13.3.2p3): for F to be a viable function, there shall 3421 // exist for each argument an implicit conversion sequence 3422 // (13.3.3.1) that converts that argument to the corresponding 3423 // parameter of F. 3424 QualType ParamType = Proto->getArgType(ArgIdx); 3425 Candidate.Conversions[ArgIdx] 3426 = TryCopyInitialization(*this, Args[ArgIdx], ParamType, 3427 SuppressUserConversions, 3428 /*InOverloadResolution=*/true); 3429 if (Candidate.Conversions[ArgIdx].isBad()) { 3430 Candidate.Viable = false; 3431 Candidate.FailureKind = ovl_fail_bad_conversion; 3432 break; 3433 } 3434 } else { 3435 // (C++ 13.3.2p2): For the purposes of overload resolution, any 3436 // argument for which there is no corresponding parameter is 3437 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 3438 Candidate.Conversions[ArgIdx].setEllipsis(); 3439 } 3440 } 3441} 3442 3443/// \brief Add all of the function declarations in the given function set to 3444/// the overload canddiate set. 3445void Sema::AddFunctionCandidates(const UnresolvedSetImpl &Fns, 3446 Expr **Args, unsigned NumArgs, 3447 OverloadCandidateSet& CandidateSet, 3448 bool SuppressUserConversions) { 3449 for (UnresolvedSetIterator F = Fns.begin(), E = Fns.end(); F != E; ++F) { 3450 NamedDecl *D = F.getDecl()->getUnderlyingDecl(); 3451 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { 3452 if (isa<CXXMethodDecl>(FD) && !cast<CXXMethodDecl>(FD)->isStatic()) 3453 AddMethodCandidate(cast<CXXMethodDecl>(FD), F.getPair(), 3454 cast<CXXMethodDecl>(FD)->getParent(), 3455 Args[0]->getType(), Args + 1, NumArgs - 1, 3456 CandidateSet, SuppressUserConversions); 3457 else 3458 AddOverloadCandidate(FD, F.getPair(), Args, NumArgs, CandidateSet, 3459 SuppressUserConversions); 3460 } else { 3461 FunctionTemplateDecl *FunTmpl = cast<FunctionTemplateDecl>(D); 3462 if (isa<CXXMethodDecl>(FunTmpl->getTemplatedDecl()) && 3463 !cast<CXXMethodDecl>(FunTmpl->getTemplatedDecl())->isStatic()) 3464 AddMethodTemplateCandidate(FunTmpl, F.getPair(), 3465 cast<CXXRecordDecl>(FunTmpl->getDeclContext()), 3466 /*FIXME: explicit args */ 0, 3467 Args[0]->getType(), Args + 1, NumArgs - 1, 3468 CandidateSet, 3469 SuppressUserConversions); 3470 else 3471 AddTemplateOverloadCandidate(FunTmpl, F.getPair(), 3472 /*FIXME: explicit args */ 0, 3473 Args, NumArgs, CandidateSet, 3474 SuppressUserConversions); 3475 } 3476 } 3477} 3478 3479/// AddMethodCandidate - Adds a named decl (which is some kind of 3480/// method) as a method candidate to the given overload set. 3481void Sema::AddMethodCandidate(DeclAccessPair FoundDecl, 3482 QualType ObjectType, 3483 Expr **Args, unsigned NumArgs, 3484 OverloadCandidateSet& CandidateSet, 3485 bool SuppressUserConversions) { 3486 NamedDecl *Decl = FoundDecl.getDecl(); 3487 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(Decl->getDeclContext()); 3488 3489 if (isa<UsingShadowDecl>(Decl)) 3490 Decl = cast<UsingShadowDecl>(Decl)->getTargetDecl(); 3491 3492 if (FunctionTemplateDecl *TD = dyn_cast<FunctionTemplateDecl>(Decl)) { 3493 assert(isa<CXXMethodDecl>(TD->getTemplatedDecl()) && 3494 "Expected a member function template"); 3495 AddMethodTemplateCandidate(TD, FoundDecl, ActingContext, 3496 /*ExplicitArgs*/ 0, 3497 ObjectType, Args, NumArgs, 3498 CandidateSet, 3499 SuppressUserConversions); 3500 } else { 3501 AddMethodCandidate(cast<CXXMethodDecl>(Decl), FoundDecl, ActingContext, 3502 ObjectType, Args, NumArgs, 3503 CandidateSet, SuppressUserConversions); 3504 } 3505} 3506 3507/// AddMethodCandidate - Adds the given C++ member function to the set 3508/// of candidate functions, using the given function call arguments 3509/// and the object argument (@c Object). For example, in a call 3510/// @c o.f(a1,a2), @c Object will contain @c o and @c Args will contain 3511/// both @c a1 and @c a2. If @p SuppressUserConversions, then don't 3512/// allow user-defined conversions via constructors or conversion 3513/// operators. 3514void 3515Sema::AddMethodCandidate(CXXMethodDecl *Method, DeclAccessPair FoundDecl, 3516 CXXRecordDecl *ActingContext, QualType ObjectType, 3517 Expr **Args, unsigned NumArgs, 3518 OverloadCandidateSet& CandidateSet, 3519 bool SuppressUserConversions) { 3520 const FunctionProtoType* Proto 3521 = dyn_cast<FunctionProtoType>(Method->getType()->getAs<FunctionType>()); 3522 assert(Proto && "Methods without a prototype cannot be overloaded"); 3523 assert(!isa<CXXConstructorDecl>(Method) && 3524 "Use AddOverloadCandidate for constructors"); 3525 3526 if (!CandidateSet.isNewCandidate(Method)) 3527 return; 3528 3529 // Overload resolution is always an unevaluated context. 3530 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 3531 3532 // Add this candidate 3533 CandidateSet.push_back(OverloadCandidate()); 3534 OverloadCandidate& Candidate = CandidateSet.back(); 3535 Candidate.FoundDecl = FoundDecl; 3536 Candidate.Function = Method; 3537 Candidate.IsSurrogate = false; 3538 Candidate.IgnoreObjectArgument = false; 3539 3540 unsigned NumArgsInProto = Proto->getNumArgs(); 3541 3542 // (C++ 13.3.2p2): A candidate function having fewer than m 3543 // parameters is viable only if it has an ellipsis in its parameter 3544 // list (8.3.5). 3545 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 3546 Candidate.Viable = false; 3547 Candidate.FailureKind = ovl_fail_too_many_arguments; 3548 return; 3549 } 3550 3551 // (C++ 13.3.2p2): A candidate function having more than m parameters 3552 // is viable only if the (m+1)st parameter has a default argument 3553 // (8.3.6). For the purposes of overload resolution, the 3554 // parameter list is truncated on the right, so that there are 3555 // exactly m parameters. 3556 unsigned MinRequiredArgs = Method->getMinRequiredArguments(); 3557 if (NumArgs < MinRequiredArgs) { 3558 // Not enough arguments. 3559 Candidate.Viable = false; 3560 Candidate.FailureKind = ovl_fail_too_few_arguments; 3561 return; 3562 } 3563 3564 Candidate.Viable = true; 3565 Candidate.Conversions.resize(NumArgs + 1); 3566 3567 if (Method->isStatic() || ObjectType.isNull()) 3568 // The implicit object argument is ignored. 3569 Candidate.IgnoreObjectArgument = true; 3570 else { 3571 // Determine the implicit conversion sequence for the object 3572 // parameter. 3573 Candidate.Conversions[0] 3574 = TryObjectArgumentInitialization(ObjectType, Method, ActingContext); 3575 if (Candidate.Conversions[0].isBad()) { 3576 Candidate.Viable = false; 3577 Candidate.FailureKind = ovl_fail_bad_conversion; 3578 return; 3579 } 3580 } 3581 3582 // Determine the implicit conversion sequences for each of the 3583 // arguments. 3584 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 3585 if (ArgIdx < NumArgsInProto) { 3586 // (C++ 13.3.2p3): for F to be a viable function, there shall 3587 // exist for each argument an implicit conversion sequence 3588 // (13.3.3.1) that converts that argument to the corresponding 3589 // parameter of F. 3590 QualType ParamType = Proto->getArgType(ArgIdx); 3591 Candidate.Conversions[ArgIdx + 1] 3592 = TryCopyInitialization(*this, Args[ArgIdx], ParamType, 3593 SuppressUserConversions, 3594 /*InOverloadResolution=*/true); 3595 if (Candidate.Conversions[ArgIdx + 1].isBad()) { 3596 Candidate.Viable = false; 3597 Candidate.FailureKind = ovl_fail_bad_conversion; 3598 break; 3599 } 3600 } else { 3601 // (C++ 13.3.2p2): For the purposes of overload resolution, any 3602 // argument for which there is no corresponding parameter is 3603 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 3604 Candidate.Conversions[ArgIdx + 1].setEllipsis(); 3605 } 3606 } 3607} 3608 3609/// \brief Add a C++ member function template as a candidate to the candidate 3610/// set, using template argument deduction to produce an appropriate member 3611/// function template specialization. 3612void 3613Sema::AddMethodTemplateCandidate(FunctionTemplateDecl *MethodTmpl, 3614 DeclAccessPair FoundDecl, 3615 CXXRecordDecl *ActingContext, 3616 const TemplateArgumentListInfo *ExplicitTemplateArgs, 3617 QualType ObjectType, 3618 Expr **Args, unsigned NumArgs, 3619 OverloadCandidateSet& CandidateSet, 3620 bool SuppressUserConversions) { 3621 if (!CandidateSet.isNewCandidate(MethodTmpl)) 3622 return; 3623 3624 // C++ [over.match.funcs]p7: 3625 // In each case where a candidate is a function template, candidate 3626 // function template specializations are generated using template argument 3627 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 3628 // candidate functions in the usual way.113) A given name can refer to one 3629 // or more function templates and also to a set of overloaded non-template 3630 // functions. In such a case, the candidate functions generated from each 3631 // function template are combined with the set of non-template candidate 3632 // functions. 3633 TemplateDeductionInfo Info(Context, CandidateSet.getLocation()); 3634 FunctionDecl *Specialization = 0; 3635 if (TemplateDeductionResult Result 3636 = DeduceTemplateArguments(MethodTmpl, ExplicitTemplateArgs, 3637 Args, NumArgs, Specialization, Info)) { 3638 CandidateSet.push_back(OverloadCandidate()); 3639 OverloadCandidate &Candidate = CandidateSet.back(); 3640 Candidate.FoundDecl = FoundDecl; 3641 Candidate.Function = MethodTmpl->getTemplatedDecl(); 3642 Candidate.Viable = false; 3643 Candidate.FailureKind = ovl_fail_bad_deduction; 3644 Candidate.IsSurrogate = false; 3645 Candidate.IgnoreObjectArgument = false; 3646 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result, 3647 Info); 3648 return; 3649 } 3650 3651 // Add the function template specialization produced by template argument 3652 // deduction as a candidate. 3653 assert(Specialization && "Missing member function template specialization?"); 3654 assert(isa<CXXMethodDecl>(Specialization) && 3655 "Specialization is not a member function?"); 3656 AddMethodCandidate(cast<CXXMethodDecl>(Specialization), FoundDecl, 3657 ActingContext, ObjectType, Args, NumArgs, 3658 CandidateSet, SuppressUserConversions); 3659} 3660 3661/// \brief Add a C++ function template specialization as a candidate 3662/// in the candidate set, using template argument deduction to produce 3663/// an appropriate function template specialization. 3664void 3665Sema::AddTemplateOverloadCandidate(FunctionTemplateDecl *FunctionTemplate, 3666 DeclAccessPair FoundDecl, 3667 const TemplateArgumentListInfo *ExplicitTemplateArgs, 3668 Expr **Args, unsigned NumArgs, 3669 OverloadCandidateSet& CandidateSet, 3670 bool SuppressUserConversions) { 3671 if (!CandidateSet.isNewCandidate(FunctionTemplate)) 3672 return; 3673 3674 // C++ [over.match.funcs]p7: 3675 // In each case where a candidate is a function template, candidate 3676 // function template specializations are generated using template argument 3677 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 3678 // candidate functions in the usual way.113) A given name can refer to one 3679 // or more function templates and also to a set of overloaded non-template 3680 // functions. In such a case, the candidate functions generated from each 3681 // function template are combined with the set of non-template candidate 3682 // functions. 3683 TemplateDeductionInfo Info(Context, CandidateSet.getLocation()); 3684 FunctionDecl *Specialization = 0; 3685 if (TemplateDeductionResult Result 3686 = DeduceTemplateArguments(FunctionTemplate, ExplicitTemplateArgs, 3687 Args, NumArgs, Specialization, Info)) { 3688 CandidateSet.push_back(OverloadCandidate()); 3689 OverloadCandidate &Candidate = CandidateSet.back(); 3690 Candidate.FoundDecl = FoundDecl; 3691 Candidate.Function = FunctionTemplate->getTemplatedDecl(); 3692 Candidate.Viable = false; 3693 Candidate.FailureKind = ovl_fail_bad_deduction; 3694 Candidate.IsSurrogate = false; 3695 Candidate.IgnoreObjectArgument = false; 3696 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result, 3697 Info); 3698 return; 3699 } 3700 3701 // Add the function template specialization produced by template argument 3702 // deduction as a candidate. 3703 assert(Specialization && "Missing function template specialization?"); 3704 AddOverloadCandidate(Specialization, FoundDecl, Args, NumArgs, CandidateSet, 3705 SuppressUserConversions); 3706} 3707 3708/// AddConversionCandidate - Add a C++ conversion function as a 3709/// candidate in the candidate set (C++ [over.match.conv], 3710/// C++ [over.match.copy]). From is the expression we're converting from, 3711/// and ToType is the type that we're eventually trying to convert to 3712/// (which may or may not be the same type as the type that the 3713/// conversion function produces). 3714void 3715Sema::AddConversionCandidate(CXXConversionDecl *Conversion, 3716 DeclAccessPair FoundDecl, 3717 CXXRecordDecl *ActingContext, 3718 Expr *From, QualType ToType, 3719 OverloadCandidateSet& CandidateSet) { 3720 assert(!Conversion->getDescribedFunctionTemplate() && 3721 "Conversion function templates use AddTemplateConversionCandidate"); 3722 QualType ConvType = Conversion->getConversionType().getNonReferenceType(); 3723 if (!CandidateSet.isNewCandidate(Conversion)) 3724 return; 3725 3726 // Overload resolution is always an unevaluated context. 3727 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 3728 3729 // Add this candidate 3730 CandidateSet.push_back(OverloadCandidate()); 3731 OverloadCandidate& Candidate = CandidateSet.back(); 3732 Candidate.FoundDecl = FoundDecl; 3733 Candidate.Function = Conversion; 3734 Candidate.IsSurrogate = false; 3735 Candidate.IgnoreObjectArgument = false; 3736 Candidate.FinalConversion.setAsIdentityConversion(); 3737 Candidate.FinalConversion.setFromType(ConvType); 3738 Candidate.FinalConversion.setAllToTypes(ToType); 3739 3740 // Determine the implicit conversion sequence for the implicit 3741 // object parameter. 3742 Candidate.Viable = true; 3743 Candidate.Conversions.resize(1); 3744 Candidate.Conversions[0] 3745 = TryObjectArgumentInitialization(From->getType(), Conversion, 3746 ActingContext); 3747 // Conversion functions to a different type in the base class is visible in 3748 // the derived class. So, a derived to base conversion should not participate 3749 // in overload resolution. 3750 if (Candidate.Conversions[0].Standard.Second == ICK_Derived_To_Base) 3751 Candidate.Conversions[0].Standard.Second = ICK_Identity; 3752 if (Candidate.Conversions[0].isBad()) { 3753 Candidate.Viable = false; 3754 Candidate.FailureKind = ovl_fail_bad_conversion; 3755 return; 3756 } 3757 3758 // We won't go through a user-define type conversion function to convert a 3759 // derived to base as such conversions are given Conversion Rank. They only 3760 // go through a copy constructor. 13.3.3.1.2-p4 [over.ics.user] 3761 QualType FromCanon 3762 = Context.getCanonicalType(From->getType().getUnqualifiedType()); 3763 QualType ToCanon = Context.getCanonicalType(ToType).getUnqualifiedType(); 3764 if (FromCanon == ToCanon || IsDerivedFrom(FromCanon, ToCanon)) { 3765 Candidate.Viable = false; 3766 Candidate.FailureKind = ovl_fail_trivial_conversion; 3767 return; 3768 } 3769 3770 // To determine what the conversion from the result of calling the 3771 // conversion function to the type we're eventually trying to 3772 // convert to (ToType), we need to synthesize a call to the 3773 // conversion function and attempt copy initialization from it. This 3774 // makes sure that we get the right semantics with respect to 3775 // lvalues/rvalues and the type. Fortunately, we can allocate this 3776 // call on the stack and we don't need its arguments to be 3777 // well-formed. 3778 DeclRefExpr ConversionRef(Conversion, Conversion->getType(), 3779 From->getLocStart()); 3780 ImplicitCastExpr ConversionFn(ImplicitCastExpr::OnStack, 3781 Context.getPointerType(Conversion->getType()), 3782 CastExpr::CK_FunctionToPointerDecay, 3783 &ConversionRef, ImplicitCastExpr::RValue); 3784 3785 // Note that it is safe to allocate CallExpr on the stack here because 3786 // there are 0 arguments (i.e., nothing is allocated using ASTContext's 3787 // allocator). 3788 CallExpr Call(Context, &ConversionFn, 0, 0, 3789 Conversion->getConversionType().getNonLValueExprType(Context), 3790 From->getLocStart()); 3791 ImplicitConversionSequence ICS = 3792 TryCopyInitialization(*this, &Call, ToType, 3793 /*SuppressUserConversions=*/true, 3794 /*InOverloadResolution=*/false); 3795 3796 switch (ICS.getKind()) { 3797 case ImplicitConversionSequence::StandardConversion: 3798 Candidate.FinalConversion = ICS.Standard; 3799 3800 // C++ [over.ics.user]p3: 3801 // If the user-defined conversion is specified by a specialization of a 3802 // conversion function template, the second standard conversion sequence 3803 // shall have exact match rank. 3804 if (Conversion->getPrimaryTemplate() && 3805 GetConversionRank(ICS.Standard.Second) != ICR_Exact_Match) { 3806 Candidate.Viable = false; 3807 Candidate.FailureKind = ovl_fail_final_conversion_not_exact; 3808 } 3809 3810 break; 3811 3812 case ImplicitConversionSequence::BadConversion: 3813 Candidate.Viable = false; 3814 Candidate.FailureKind = ovl_fail_bad_final_conversion; 3815 break; 3816 3817 default: 3818 assert(false && 3819 "Can only end up with a standard conversion sequence or failure"); 3820 } 3821} 3822 3823/// \brief Adds a conversion function template specialization 3824/// candidate to the overload set, using template argument deduction 3825/// to deduce the template arguments of the conversion function 3826/// template from the type that we are converting to (C++ 3827/// [temp.deduct.conv]). 3828void 3829Sema::AddTemplateConversionCandidate(FunctionTemplateDecl *FunctionTemplate, 3830 DeclAccessPair FoundDecl, 3831 CXXRecordDecl *ActingDC, 3832 Expr *From, QualType ToType, 3833 OverloadCandidateSet &CandidateSet) { 3834 assert(isa<CXXConversionDecl>(FunctionTemplate->getTemplatedDecl()) && 3835 "Only conversion function templates permitted here"); 3836 3837 if (!CandidateSet.isNewCandidate(FunctionTemplate)) 3838 return; 3839 3840 TemplateDeductionInfo Info(Context, CandidateSet.getLocation()); 3841 CXXConversionDecl *Specialization = 0; 3842 if (TemplateDeductionResult Result 3843 = DeduceTemplateArguments(FunctionTemplate, ToType, 3844 Specialization, Info)) { 3845 CandidateSet.push_back(OverloadCandidate()); 3846 OverloadCandidate &Candidate = CandidateSet.back(); 3847 Candidate.FoundDecl = FoundDecl; 3848 Candidate.Function = FunctionTemplate->getTemplatedDecl(); 3849 Candidate.Viable = false; 3850 Candidate.FailureKind = ovl_fail_bad_deduction; 3851 Candidate.IsSurrogate = false; 3852 Candidate.IgnoreObjectArgument = false; 3853 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result, 3854 Info); 3855 return; 3856 } 3857 3858 // Add the conversion function template specialization produced by 3859 // template argument deduction as a candidate. 3860 assert(Specialization && "Missing function template specialization?"); 3861 AddConversionCandidate(Specialization, FoundDecl, ActingDC, From, ToType, 3862 CandidateSet); 3863} 3864 3865/// AddSurrogateCandidate - Adds a "surrogate" candidate function that 3866/// converts the given @c Object to a function pointer via the 3867/// conversion function @c Conversion, and then attempts to call it 3868/// with the given arguments (C++ [over.call.object]p2-4). Proto is 3869/// the type of function that we'll eventually be calling. 3870void Sema::AddSurrogateCandidate(CXXConversionDecl *Conversion, 3871 DeclAccessPair FoundDecl, 3872 CXXRecordDecl *ActingContext, 3873 const FunctionProtoType *Proto, 3874 QualType ObjectType, 3875 Expr **Args, unsigned NumArgs, 3876 OverloadCandidateSet& CandidateSet) { 3877 if (!CandidateSet.isNewCandidate(Conversion)) 3878 return; 3879 3880 // Overload resolution is always an unevaluated context. 3881 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 3882 3883 CandidateSet.push_back(OverloadCandidate()); 3884 OverloadCandidate& Candidate = CandidateSet.back(); 3885 Candidate.FoundDecl = FoundDecl; 3886 Candidate.Function = 0; 3887 Candidate.Surrogate = Conversion; 3888 Candidate.Viable = true; 3889 Candidate.IsSurrogate = true; 3890 Candidate.IgnoreObjectArgument = false; 3891 Candidate.Conversions.resize(NumArgs + 1); 3892 3893 // Determine the implicit conversion sequence for the implicit 3894 // object parameter. 3895 ImplicitConversionSequence ObjectInit 3896 = TryObjectArgumentInitialization(ObjectType, Conversion, ActingContext); 3897 if (ObjectInit.isBad()) { 3898 Candidate.Viable = false; 3899 Candidate.FailureKind = ovl_fail_bad_conversion; 3900 Candidate.Conversions[0] = ObjectInit; 3901 return; 3902 } 3903 3904 // The first conversion is actually a user-defined conversion whose 3905 // first conversion is ObjectInit's standard conversion (which is 3906 // effectively a reference binding). Record it as such. 3907 Candidate.Conversions[0].setUserDefined(); 3908 Candidate.Conversions[0].UserDefined.Before = ObjectInit.Standard; 3909 Candidate.Conversions[0].UserDefined.EllipsisConversion = false; 3910 Candidate.Conversions[0].UserDefined.ConversionFunction = Conversion; 3911 Candidate.Conversions[0].UserDefined.After 3912 = Candidate.Conversions[0].UserDefined.Before; 3913 Candidate.Conversions[0].UserDefined.After.setAsIdentityConversion(); 3914 3915 // Find the 3916 unsigned NumArgsInProto = Proto->getNumArgs(); 3917 3918 // (C++ 13.3.2p2): A candidate function having fewer than m 3919 // parameters is viable only if it has an ellipsis in its parameter 3920 // list (8.3.5). 3921 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 3922 Candidate.Viable = false; 3923 Candidate.FailureKind = ovl_fail_too_many_arguments; 3924 return; 3925 } 3926 3927 // Function types don't have any default arguments, so just check if 3928 // we have enough arguments. 3929 if (NumArgs < NumArgsInProto) { 3930 // Not enough arguments. 3931 Candidate.Viable = false; 3932 Candidate.FailureKind = ovl_fail_too_few_arguments; 3933 return; 3934 } 3935 3936 // Determine the implicit conversion sequences for each of the 3937 // arguments. 3938 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 3939 if (ArgIdx < NumArgsInProto) { 3940 // (C++ 13.3.2p3): for F to be a viable function, there shall 3941 // exist for each argument an implicit conversion sequence 3942 // (13.3.3.1) that converts that argument to the corresponding 3943 // parameter of F. 3944 QualType ParamType = Proto->getArgType(ArgIdx); 3945 Candidate.Conversions[ArgIdx + 1] 3946 = TryCopyInitialization(*this, Args[ArgIdx], ParamType, 3947 /*SuppressUserConversions=*/false, 3948 /*InOverloadResolution=*/false); 3949 if (Candidate.Conversions[ArgIdx + 1].isBad()) { 3950 Candidate.Viable = false; 3951 Candidate.FailureKind = ovl_fail_bad_conversion; 3952 break; 3953 } 3954 } else { 3955 // (C++ 13.3.2p2): For the purposes of overload resolution, any 3956 // argument for which there is no corresponding parameter is 3957 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 3958 Candidate.Conversions[ArgIdx + 1].setEllipsis(); 3959 } 3960 } 3961} 3962 3963/// \brief Add overload candidates for overloaded operators that are 3964/// member functions. 3965/// 3966/// Add the overloaded operator candidates that are member functions 3967/// for the operator Op that was used in an operator expression such 3968/// as "x Op y". , Args/NumArgs provides the operator arguments, and 3969/// CandidateSet will store the added overload candidates. (C++ 3970/// [over.match.oper]). 3971void Sema::AddMemberOperatorCandidates(OverloadedOperatorKind Op, 3972 SourceLocation OpLoc, 3973 Expr **Args, unsigned NumArgs, 3974 OverloadCandidateSet& CandidateSet, 3975 SourceRange OpRange) { 3976 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 3977 3978 // C++ [over.match.oper]p3: 3979 // For a unary operator @ with an operand of a type whose 3980 // cv-unqualified version is T1, and for a binary operator @ with 3981 // a left operand of a type whose cv-unqualified version is T1 and 3982 // a right operand of a type whose cv-unqualified version is T2, 3983 // three sets of candidate functions, designated member 3984 // candidates, non-member candidates and built-in candidates, are 3985 // constructed as follows: 3986 QualType T1 = Args[0]->getType(); 3987 QualType T2; 3988 if (NumArgs > 1) 3989 T2 = Args[1]->getType(); 3990 3991 // -- If T1 is a class type, the set of member candidates is the 3992 // result of the qualified lookup of T1::operator@ 3993 // (13.3.1.1.1); otherwise, the set of member candidates is 3994 // empty. 3995 if (const RecordType *T1Rec = T1->getAs<RecordType>()) { 3996 // Complete the type if it can be completed. Otherwise, we're done. 3997 if (RequireCompleteType(OpLoc, T1, PDiag())) 3998 return; 3999 4000 LookupResult Operators(*this, OpName, OpLoc, LookupOrdinaryName); 4001 LookupQualifiedName(Operators, T1Rec->getDecl()); 4002 Operators.suppressDiagnostics(); 4003 4004 for (LookupResult::iterator Oper = Operators.begin(), 4005 OperEnd = Operators.end(); 4006 Oper != OperEnd; 4007 ++Oper) 4008 AddMethodCandidate(Oper.getPair(), Args[0]->getType(), 4009 Args + 1, NumArgs - 1, CandidateSet, 4010 /* SuppressUserConversions = */ false); 4011 } 4012} 4013 4014/// AddBuiltinCandidate - Add a candidate for a built-in 4015/// operator. ResultTy and ParamTys are the result and parameter types 4016/// of the built-in candidate, respectively. Args and NumArgs are the 4017/// arguments being passed to the candidate. IsAssignmentOperator 4018/// should be true when this built-in candidate is an assignment 4019/// operator. NumContextualBoolArguments is the number of arguments 4020/// (at the beginning of the argument list) that will be contextually 4021/// converted to bool. 4022void Sema::AddBuiltinCandidate(QualType ResultTy, QualType *ParamTys, 4023 Expr **Args, unsigned NumArgs, 4024 OverloadCandidateSet& CandidateSet, 4025 bool IsAssignmentOperator, 4026 unsigned NumContextualBoolArguments) { 4027 // Overload resolution is always an unevaluated context. 4028 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 4029 4030 // Add this candidate 4031 CandidateSet.push_back(OverloadCandidate()); 4032 OverloadCandidate& Candidate = CandidateSet.back(); 4033 Candidate.FoundDecl = DeclAccessPair::make(0, AS_none); 4034 Candidate.Function = 0; 4035 Candidate.IsSurrogate = false; 4036 Candidate.IgnoreObjectArgument = false; 4037 Candidate.BuiltinTypes.ResultTy = ResultTy; 4038 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 4039 Candidate.BuiltinTypes.ParamTypes[ArgIdx] = ParamTys[ArgIdx]; 4040 4041 // Determine the implicit conversion sequences for each of the 4042 // arguments. 4043 Candidate.Viable = true; 4044 Candidate.Conversions.resize(NumArgs); 4045 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 4046 // C++ [over.match.oper]p4: 4047 // For the built-in assignment operators, conversions of the 4048 // left operand are restricted as follows: 4049 // -- no temporaries are introduced to hold the left operand, and 4050 // -- no user-defined conversions are applied to the left 4051 // operand to achieve a type match with the left-most 4052 // parameter of a built-in candidate. 4053 // 4054 // We block these conversions by turning off user-defined 4055 // conversions, since that is the only way that initialization of 4056 // a reference to a non-class type can occur from something that 4057 // is not of the same type. 4058 if (ArgIdx < NumContextualBoolArguments) { 4059 assert(ParamTys[ArgIdx] == Context.BoolTy && 4060 "Contextual conversion to bool requires bool type"); 4061 Candidate.Conversions[ArgIdx] = TryContextuallyConvertToBool(Args[ArgIdx]); 4062 } else { 4063 Candidate.Conversions[ArgIdx] 4064 = TryCopyInitialization(*this, Args[ArgIdx], ParamTys[ArgIdx], 4065 ArgIdx == 0 && IsAssignmentOperator, 4066 /*InOverloadResolution=*/false); 4067 } 4068 if (Candidate.Conversions[ArgIdx].isBad()) { 4069 Candidate.Viable = false; 4070 Candidate.FailureKind = ovl_fail_bad_conversion; 4071 break; 4072 } 4073 } 4074} 4075 4076/// BuiltinCandidateTypeSet - A set of types that will be used for the 4077/// candidate operator functions for built-in operators (C++ 4078/// [over.built]). The types are separated into pointer types and 4079/// enumeration types. 4080class BuiltinCandidateTypeSet { 4081 /// TypeSet - A set of types. 4082 typedef llvm::SmallPtrSet<QualType, 8> TypeSet; 4083 4084 /// PointerTypes - The set of pointer types that will be used in the 4085 /// built-in candidates. 4086 TypeSet PointerTypes; 4087 4088 /// MemberPointerTypes - The set of member pointer types that will be 4089 /// used in the built-in candidates. 4090 TypeSet MemberPointerTypes; 4091 4092 /// EnumerationTypes - The set of enumeration types that will be 4093 /// used in the built-in candidates. 4094 TypeSet EnumerationTypes; 4095 4096 /// \brief The set of vector types that will be used in the built-in 4097 /// candidates. 4098 TypeSet VectorTypes; 4099 4100 /// Sema - The semantic analysis instance where we are building the 4101 /// candidate type set. 4102 Sema &SemaRef; 4103 4104 /// Context - The AST context in which we will build the type sets. 4105 ASTContext &Context; 4106 4107 bool AddPointerWithMoreQualifiedTypeVariants(QualType Ty, 4108 const Qualifiers &VisibleQuals); 4109 bool AddMemberPointerWithMoreQualifiedTypeVariants(QualType Ty); 4110 4111public: 4112 /// iterator - Iterates through the types that are part of the set. 4113 typedef TypeSet::iterator iterator; 4114 4115 BuiltinCandidateTypeSet(Sema &SemaRef) 4116 : SemaRef(SemaRef), Context(SemaRef.Context) { } 4117 4118 void AddTypesConvertedFrom(QualType Ty, 4119 SourceLocation Loc, 4120 bool AllowUserConversions, 4121 bool AllowExplicitConversions, 4122 const Qualifiers &VisibleTypeConversionsQuals); 4123 4124 /// pointer_begin - First pointer type found; 4125 iterator pointer_begin() { return PointerTypes.begin(); } 4126 4127 /// pointer_end - Past the last pointer type found; 4128 iterator pointer_end() { return PointerTypes.end(); } 4129 4130 /// member_pointer_begin - First member pointer type found; 4131 iterator member_pointer_begin() { return MemberPointerTypes.begin(); } 4132 4133 /// member_pointer_end - Past the last member pointer type found; 4134 iterator member_pointer_end() { return MemberPointerTypes.end(); } 4135 4136 /// enumeration_begin - First enumeration type found; 4137 iterator enumeration_begin() { return EnumerationTypes.begin(); } 4138 4139 /// enumeration_end - Past the last enumeration type found; 4140 iterator enumeration_end() { return EnumerationTypes.end(); } 4141 4142 iterator vector_begin() { return VectorTypes.begin(); } 4143 iterator vector_end() { return VectorTypes.end(); } 4144}; 4145 4146/// AddPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty to 4147/// the set of pointer types along with any more-qualified variants of 4148/// that type. For example, if @p Ty is "int const *", this routine 4149/// will add "int const *", "int const volatile *", "int const 4150/// restrict *", and "int const volatile restrict *" to the set of 4151/// pointer types. Returns true if the add of @p Ty itself succeeded, 4152/// false otherwise. 4153/// 4154/// FIXME: what to do about extended qualifiers? 4155bool 4156BuiltinCandidateTypeSet::AddPointerWithMoreQualifiedTypeVariants(QualType Ty, 4157 const Qualifiers &VisibleQuals) { 4158 4159 // Insert this type. 4160 if (!PointerTypes.insert(Ty)) 4161 return false; 4162 4163 const PointerType *PointerTy = Ty->getAs<PointerType>(); 4164 assert(PointerTy && "type was not a pointer type!"); 4165 4166 QualType PointeeTy = PointerTy->getPointeeType(); 4167 // Don't add qualified variants of arrays. For one, they're not allowed 4168 // (the qualifier would sink to the element type), and for another, the 4169 // only overload situation where it matters is subscript or pointer +- int, 4170 // and those shouldn't have qualifier variants anyway. 4171 if (PointeeTy->isArrayType()) 4172 return true; 4173 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 4174 if (const ConstantArrayType *Array =Context.getAsConstantArrayType(PointeeTy)) 4175 BaseCVR = Array->getElementType().getCVRQualifiers(); 4176 bool hasVolatile = VisibleQuals.hasVolatile(); 4177 bool hasRestrict = VisibleQuals.hasRestrict(); 4178 4179 // Iterate through all strict supersets of BaseCVR. 4180 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 4181 if ((CVR | BaseCVR) != CVR) continue; 4182 // Skip over Volatile/Restrict if no Volatile/Restrict found anywhere 4183 // in the types. 4184 if ((CVR & Qualifiers::Volatile) && !hasVolatile) continue; 4185 if ((CVR & Qualifiers::Restrict) && !hasRestrict) continue; 4186 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 4187 PointerTypes.insert(Context.getPointerType(QPointeeTy)); 4188 } 4189 4190 return true; 4191} 4192 4193/// AddMemberPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty 4194/// to the set of pointer types along with any more-qualified variants of 4195/// that type. For example, if @p Ty is "int const *", this routine 4196/// will add "int const *", "int const volatile *", "int const 4197/// restrict *", and "int const volatile restrict *" to the set of 4198/// pointer types. Returns true if the add of @p Ty itself succeeded, 4199/// false otherwise. 4200/// 4201/// FIXME: what to do about extended qualifiers? 4202bool 4203BuiltinCandidateTypeSet::AddMemberPointerWithMoreQualifiedTypeVariants( 4204 QualType Ty) { 4205 // Insert this type. 4206 if (!MemberPointerTypes.insert(Ty)) 4207 return false; 4208 4209 const MemberPointerType *PointerTy = Ty->getAs<MemberPointerType>(); 4210 assert(PointerTy && "type was not a member pointer type!"); 4211 4212 QualType PointeeTy = PointerTy->getPointeeType(); 4213 // Don't add qualified variants of arrays. For one, they're not allowed 4214 // (the qualifier would sink to the element type), and for another, the 4215 // only overload situation where it matters is subscript or pointer +- int, 4216 // and those shouldn't have qualifier variants anyway. 4217 if (PointeeTy->isArrayType()) 4218 return true; 4219 const Type *ClassTy = PointerTy->getClass(); 4220 4221 // Iterate through all strict supersets of the pointee type's CVR 4222 // qualifiers. 4223 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 4224 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 4225 if ((CVR | BaseCVR) != CVR) continue; 4226 4227 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 4228 MemberPointerTypes.insert(Context.getMemberPointerType(QPointeeTy, ClassTy)); 4229 } 4230 4231 return true; 4232} 4233 4234/// AddTypesConvertedFrom - Add each of the types to which the type @p 4235/// Ty can be implicit converted to the given set of @p Types. We're 4236/// primarily interested in pointer types and enumeration types. We also 4237/// take member pointer types, for the conditional operator. 4238/// AllowUserConversions is true if we should look at the conversion 4239/// functions of a class type, and AllowExplicitConversions if we 4240/// should also include the explicit conversion functions of a class 4241/// type. 4242void 4243BuiltinCandidateTypeSet::AddTypesConvertedFrom(QualType Ty, 4244 SourceLocation Loc, 4245 bool AllowUserConversions, 4246 bool AllowExplicitConversions, 4247 const Qualifiers &VisibleQuals) { 4248 // Only deal with canonical types. 4249 Ty = Context.getCanonicalType(Ty); 4250 4251 // Look through reference types; they aren't part of the type of an 4252 // expression for the purposes of conversions. 4253 if (const ReferenceType *RefTy = Ty->getAs<ReferenceType>()) 4254 Ty = RefTy->getPointeeType(); 4255 4256 // We don't care about qualifiers on the type. 4257 Ty = Ty.getLocalUnqualifiedType(); 4258 4259 // If we're dealing with an array type, decay to the pointer. 4260 if (Ty->isArrayType()) 4261 Ty = SemaRef.Context.getArrayDecayedType(Ty); 4262 4263 if (const PointerType *PointerTy = Ty->getAs<PointerType>()) { 4264 QualType PointeeTy = PointerTy->getPointeeType(); 4265 4266 // Insert our type, and its more-qualified variants, into the set 4267 // of types. 4268 if (!AddPointerWithMoreQualifiedTypeVariants(Ty, VisibleQuals)) 4269 return; 4270 } else if (Ty->isMemberPointerType()) { 4271 // Member pointers are far easier, since the pointee can't be converted. 4272 if (!AddMemberPointerWithMoreQualifiedTypeVariants(Ty)) 4273 return; 4274 } else if (Ty->isEnumeralType()) { 4275 EnumerationTypes.insert(Ty); 4276 } else if (Ty->isVectorType()) { 4277 VectorTypes.insert(Ty); 4278 } else if (AllowUserConversions) { 4279 if (const RecordType *TyRec = Ty->getAs<RecordType>()) { 4280 if (SemaRef.RequireCompleteType(Loc, Ty, 0)) { 4281 // No conversion functions in incomplete types. 4282 return; 4283 } 4284 4285 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 4286 const UnresolvedSetImpl *Conversions 4287 = ClassDecl->getVisibleConversionFunctions(); 4288 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 4289 E = Conversions->end(); I != E; ++I) { 4290 NamedDecl *D = I.getDecl(); 4291 if (isa<UsingShadowDecl>(D)) 4292 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 4293 4294 // Skip conversion function templates; they don't tell us anything 4295 // about which builtin types we can convert to. 4296 if (isa<FunctionTemplateDecl>(D)) 4297 continue; 4298 4299 CXXConversionDecl *Conv = cast<CXXConversionDecl>(D); 4300 if (AllowExplicitConversions || !Conv->isExplicit()) { 4301 AddTypesConvertedFrom(Conv->getConversionType(), Loc, false, false, 4302 VisibleQuals); 4303 } 4304 } 4305 } 4306 } 4307} 4308 4309/// \brief Helper function for AddBuiltinOperatorCandidates() that adds 4310/// the volatile- and non-volatile-qualified assignment operators for the 4311/// given type to the candidate set. 4312static void AddBuiltinAssignmentOperatorCandidates(Sema &S, 4313 QualType T, 4314 Expr **Args, 4315 unsigned NumArgs, 4316 OverloadCandidateSet &CandidateSet) { 4317 QualType ParamTypes[2]; 4318 4319 // T& operator=(T&, T) 4320 ParamTypes[0] = S.Context.getLValueReferenceType(T); 4321 ParamTypes[1] = T; 4322 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4323 /*IsAssignmentOperator=*/true); 4324 4325 if (!S.Context.getCanonicalType(T).isVolatileQualified()) { 4326 // volatile T& operator=(volatile T&, T) 4327 ParamTypes[0] 4328 = S.Context.getLValueReferenceType(S.Context.getVolatileType(T)); 4329 ParamTypes[1] = T; 4330 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4331 /*IsAssignmentOperator=*/true); 4332 } 4333} 4334 4335/// CollectVRQualifiers - This routine returns Volatile/Restrict qualifiers, 4336/// if any, found in visible type conversion functions found in ArgExpr's type. 4337static Qualifiers CollectVRQualifiers(ASTContext &Context, Expr* ArgExpr) { 4338 Qualifiers VRQuals; 4339 const RecordType *TyRec; 4340 if (const MemberPointerType *RHSMPType = 4341 ArgExpr->getType()->getAs<MemberPointerType>()) 4342 TyRec = RHSMPType->getClass()->getAs<RecordType>(); 4343 else 4344 TyRec = ArgExpr->getType()->getAs<RecordType>(); 4345 if (!TyRec) { 4346 // Just to be safe, assume the worst case. 4347 VRQuals.addVolatile(); 4348 VRQuals.addRestrict(); 4349 return VRQuals; 4350 } 4351 4352 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 4353 if (!ClassDecl->hasDefinition()) 4354 return VRQuals; 4355 4356 const UnresolvedSetImpl *Conversions = 4357 ClassDecl->getVisibleConversionFunctions(); 4358 4359 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 4360 E = Conversions->end(); I != E; ++I) { 4361 NamedDecl *D = I.getDecl(); 4362 if (isa<UsingShadowDecl>(D)) 4363 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 4364 if (CXXConversionDecl *Conv = dyn_cast<CXXConversionDecl>(D)) { 4365 QualType CanTy = Context.getCanonicalType(Conv->getConversionType()); 4366 if (const ReferenceType *ResTypeRef = CanTy->getAs<ReferenceType>()) 4367 CanTy = ResTypeRef->getPointeeType(); 4368 // Need to go down the pointer/mempointer chain and add qualifiers 4369 // as see them. 4370 bool done = false; 4371 while (!done) { 4372 if (const PointerType *ResTypePtr = CanTy->getAs<PointerType>()) 4373 CanTy = ResTypePtr->getPointeeType(); 4374 else if (const MemberPointerType *ResTypeMPtr = 4375 CanTy->getAs<MemberPointerType>()) 4376 CanTy = ResTypeMPtr->getPointeeType(); 4377 else 4378 done = true; 4379 if (CanTy.isVolatileQualified()) 4380 VRQuals.addVolatile(); 4381 if (CanTy.isRestrictQualified()) 4382 VRQuals.addRestrict(); 4383 if (VRQuals.hasRestrict() && VRQuals.hasVolatile()) 4384 return VRQuals; 4385 } 4386 } 4387 } 4388 return VRQuals; 4389} 4390 4391/// AddBuiltinOperatorCandidates - Add the appropriate built-in 4392/// operator overloads to the candidate set (C++ [over.built]), based 4393/// on the operator @p Op and the arguments given. For example, if the 4394/// operator is a binary '+', this routine might add "int 4395/// operator+(int, int)" to cover integer addition. 4396void 4397Sema::AddBuiltinOperatorCandidates(OverloadedOperatorKind Op, 4398 SourceLocation OpLoc, 4399 Expr **Args, unsigned NumArgs, 4400 OverloadCandidateSet& CandidateSet) { 4401 // The set of "promoted arithmetic types", which are the arithmetic 4402 // types are that preserved by promotion (C++ [over.built]p2). Note 4403 // that the first few of these types are the promoted integral 4404 // types; these types need to be first. 4405 // FIXME: What about complex? 4406 const unsigned FirstIntegralType = 0; 4407 const unsigned LastIntegralType = 13; 4408 const unsigned FirstPromotedIntegralType = 7, 4409 LastPromotedIntegralType = 13; 4410 const unsigned FirstPromotedArithmeticType = 7, 4411 LastPromotedArithmeticType = 16; 4412 const unsigned NumArithmeticTypes = 16; 4413 QualType ArithmeticTypes[NumArithmeticTypes] = { 4414 Context.BoolTy, Context.CharTy, Context.WCharTy, 4415// FIXME: Context.Char16Ty, Context.Char32Ty, 4416 Context.SignedCharTy, Context.ShortTy, 4417 Context.UnsignedCharTy, Context.UnsignedShortTy, 4418 Context.IntTy, Context.LongTy, Context.LongLongTy, 4419 Context.UnsignedIntTy, Context.UnsignedLongTy, Context.UnsignedLongLongTy, 4420 Context.FloatTy, Context.DoubleTy, Context.LongDoubleTy 4421 }; 4422 assert(ArithmeticTypes[FirstPromotedIntegralType] == Context.IntTy && 4423 "Invalid first promoted integral type"); 4424 assert(ArithmeticTypes[LastPromotedIntegralType - 1] 4425 == Context.UnsignedLongLongTy && 4426 "Invalid last promoted integral type"); 4427 assert(ArithmeticTypes[FirstPromotedArithmeticType] == Context.IntTy && 4428 "Invalid first promoted arithmetic type"); 4429 assert(ArithmeticTypes[LastPromotedArithmeticType - 1] 4430 == Context.LongDoubleTy && 4431 "Invalid last promoted arithmetic type"); 4432 4433 // Find all of the types that the arguments can convert to, but only 4434 // if the operator we're looking at has built-in operator candidates 4435 // that make use of these types. 4436 Qualifiers VisibleTypeConversionsQuals; 4437 VisibleTypeConversionsQuals.addConst(); 4438 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 4439 VisibleTypeConversionsQuals += CollectVRQualifiers(Context, Args[ArgIdx]); 4440 4441 BuiltinCandidateTypeSet CandidateTypes(*this); 4442 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 4443 CandidateTypes.AddTypesConvertedFrom(Args[ArgIdx]->getType(), 4444 OpLoc, 4445 true, 4446 (Op == OO_Exclaim || 4447 Op == OO_AmpAmp || 4448 Op == OO_PipePipe), 4449 VisibleTypeConversionsQuals); 4450 4451 bool isComparison = false; 4452 switch (Op) { 4453 case OO_None: 4454 case NUM_OVERLOADED_OPERATORS: 4455 assert(false && "Expected an overloaded operator"); 4456 break; 4457 4458 case OO_Star: // '*' is either unary or binary 4459 if (NumArgs == 1) 4460 goto UnaryStar; 4461 else 4462 goto BinaryStar; 4463 break; 4464 4465 case OO_Plus: // '+' is either unary or binary 4466 if (NumArgs == 1) 4467 goto UnaryPlus; 4468 else 4469 goto BinaryPlus; 4470 break; 4471 4472 case OO_Minus: // '-' is either unary or binary 4473 if (NumArgs == 1) 4474 goto UnaryMinus; 4475 else 4476 goto BinaryMinus; 4477 break; 4478 4479 case OO_Amp: // '&' is either unary or binary 4480 if (NumArgs == 1) 4481 goto UnaryAmp; 4482 else 4483 goto BinaryAmp; 4484 4485 case OO_PlusPlus: 4486 case OO_MinusMinus: 4487 // C++ [over.built]p3: 4488 // 4489 // For every pair (T, VQ), where T is an arithmetic type, and VQ 4490 // is either volatile or empty, there exist candidate operator 4491 // functions of the form 4492 // 4493 // VQ T& operator++(VQ T&); 4494 // T operator++(VQ T&, int); 4495 // 4496 // C++ [over.built]p4: 4497 // 4498 // For every pair (T, VQ), where T is an arithmetic type other 4499 // than bool, and VQ is either volatile or empty, there exist 4500 // candidate operator functions of the form 4501 // 4502 // VQ T& operator--(VQ T&); 4503 // T operator--(VQ T&, int); 4504 for (unsigned Arith = (Op == OO_PlusPlus? 0 : 1); 4505 Arith < NumArithmeticTypes; ++Arith) { 4506 QualType ArithTy = ArithmeticTypes[Arith]; 4507 QualType ParamTypes[2] 4508 = { Context.getLValueReferenceType(ArithTy), Context.IntTy }; 4509 4510 // Non-volatile version. 4511 if (NumArgs == 1) 4512 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 4513 else 4514 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 4515 // heuristic to reduce number of builtin candidates in the set. 4516 // Add volatile version only if there are conversions to a volatile type. 4517 if (VisibleTypeConversionsQuals.hasVolatile()) { 4518 // Volatile version 4519 ParamTypes[0] 4520 = Context.getLValueReferenceType(Context.getVolatileType(ArithTy)); 4521 if (NumArgs == 1) 4522 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 4523 else 4524 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 4525 } 4526 } 4527 4528 // C++ [over.built]p5: 4529 // 4530 // For every pair (T, VQ), where T is a cv-qualified or 4531 // cv-unqualified object type, and VQ is either volatile or 4532 // empty, there exist candidate operator functions of the form 4533 // 4534 // T*VQ& operator++(T*VQ&); 4535 // T*VQ& operator--(T*VQ&); 4536 // T* operator++(T*VQ&, int); 4537 // T* operator--(T*VQ&, int); 4538 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 4539 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4540 // Skip pointer types that aren't pointers to object types. 4541 if (!(*Ptr)->getPointeeType()->isIncompleteOrObjectType()) 4542 continue; 4543 4544 QualType ParamTypes[2] = { 4545 Context.getLValueReferenceType(*Ptr), Context.IntTy 4546 }; 4547 4548 // Without volatile 4549 if (NumArgs == 1) 4550 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 4551 else 4552 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 4553 4554 if (!Context.getCanonicalType(*Ptr).isVolatileQualified() && 4555 VisibleTypeConversionsQuals.hasVolatile()) { 4556 // With volatile 4557 ParamTypes[0] 4558 = Context.getLValueReferenceType(Context.getVolatileType(*Ptr)); 4559 if (NumArgs == 1) 4560 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 4561 else 4562 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 4563 } 4564 } 4565 break; 4566 4567 UnaryStar: 4568 // C++ [over.built]p6: 4569 // For every cv-qualified or cv-unqualified object type T, there 4570 // exist candidate operator functions of the form 4571 // 4572 // T& operator*(T*); 4573 // 4574 // C++ [over.built]p7: 4575 // For every function type T, there exist candidate operator 4576 // functions of the form 4577 // T& operator*(T*); 4578 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 4579 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4580 QualType ParamTy = *Ptr; 4581 QualType PointeeTy = ParamTy->getAs<PointerType>()->getPointeeType(); 4582 AddBuiltinCandidate(Context.getLValueReferenceType(PointeeTy), 4583 &ParamTy, Args, 1, CandidateSet); 4584 } 4585 break; 4586 4587 UnaryPlus: 4588 // C++ [over.built]p8: 4589 // For every type T, there exist candidate operator functions of 4590 // the form 4591 // 4592 // T* operator+(T*); 4593 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 4594 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4595 QualType ParamTy = *Ptr; 4596 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet); 4597 } 4598 4599 // Fall through 4600 4601 UnaryMinus: 4602 // C++ [over.built]p9: 4603 // For every promoted arithmetic type T, there exist candidate 4604 // operator functions of the form 4605 // 4606 // T operator+(T); 4607 // T operator-(T); 4608 for (unsigned Arith = FirstPromotedArithmeticType; 4609 Arith < LastPromotedArithmeticType; ++Arith) { 4610 QualType ArithTy = ArithmeticTypes[Arith]; 4611 AddBuiltinCandidate(ArithTy, &ArithTy, Args, 1, CandidateSet); 4612 } 4613 4614 // Extension: We also add these operators for vector types. 4615 for (BuiltinCandidateTypeSet::iterator Vec = CandidateTypes.vector_begin(), 4616 VecEnd = CandidateTypes.vector_end(); 4617 Vec != VecEnd; ++Vec) { 4618 QualType VecTy = *Vec; 4619 AddBuiltinCandidate(VecTy, &VecTy, Args, 1, CandidateSet); 4620 } 4621 break; 4622 4623 case OO_Tilde: 4624 // C++ [over.built]p10: 4625 // For every promoted integral type T, there exist candidate 4626 // operator functions of the form 4627 // 4628 // T operator~(T); 4629 for (unsigned Int = FirstPromotedIntegralType; 4630 Int < LastPromotedIntegralType; ++Int) { 4631 QualType IntTy = ArithmeticTypes[Int]; 4632 AddBuiltinCandidate(IntTy, &IntTy, Args, 1, CandidateSet); 4633 } 4634 4635 // Extension: We also add this operator for vector types. 4636 for (BuiltinCandidateTypeSet::iterator Vec = CandidateTypes.vector_begin(), 4637 VecEnd = CandidateTypes.vector_end(); 4638 Vec != VecEnd; ++Vec) { 4639 QualType VecTy = *Vec; 4640 AddBuiltinCandidate(VecTy, &VecTy, Args, 1, CandidateSet); 4641 } 4642 break; 4643 4644 case OO_New: 4645 case OO_Delete: 4646 case OO_Array_New: 4647 case OO_Array_Delete: 4648 case OO_Call: 4649 assert(false && "Special operators don't use AddBuiltinOperatorCandidates"); 4650 break; 4651 4652 case OO_Comma: 4653 UnaryAmp: 4654 case OO_Arrow: 4655 // C++ [over.match.oper]p3: 4656 // -- For the operator ',', the unary operator '&', or the 4657 // operator '->', the built-in candidates set is empty. 4658 break; 4659 4660 case OO_EqualEqual: 4661 case OO_ExclaimEqual: 4662 // C++ [over.match.oper]p16: 4663 // For every pointer to member type T, there exist candidate operator 4664 // functions of the form 4665 // 4666 // bool operator==(T,T); 4667 // bool operator!=(T,T); 4668 for (BuiltinCandidateTypeSet::iterator 4669 MemPtr = CandidateTypes.member_pointer_begin(), 4670 MemPtrEnd = CandidateTypes.member_pointer_end(); 4671 MemPtr != MemPtrEnd; 4672 ++MemPtr) { 4673 QualType ParamTypes[2] = { *MemPtr, *MemPtr }; 4674 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 4675 } 4676 4677 // Fall through 4678 4679 case OO_Less: 4680 case OO_Greater: 4681 case OO_LessEqual: 4682 case OO_GreaterEqual: 4683 // C++ [over.built]p15: 4684 // 4685 // For every pointer or enumeration type T, there exist 4686 // candidate operator functions of the form 4687 // 4688 // bool operator<(T, T); 4689 // bool operator>(T, T); 4690 // bool operator<=(T, T); 4691 // bool operator>=(T, T); 4692 // bool operator==(T, T); 4693 // bool operator!=(T, T); 4694 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 4695 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4696 QualType ParamTypes[2] = { *Ptr, *Ptr }; 4697 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 4698 } 4699 for (BuiltinCandidateTypeSet::iterator Enum 4700 = CandidateTypes.enumeration_begin(); 4701 Enum != CandidateTypes.enumeration_end(); ++Enum) { 4702 QualType ParamTypes[2] = { *Enum, *Enum }; 4703 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 4704 } 4705 4706 // Fall through. 4707 isComparison = true; 4708 4709 BinaryPlus: 4710 BinaryMinus: 4711 if (!isComparison) { 4712 // We didn't fall through, so we must have OO_Plus or OO_Minus. 4713 4714 // C++ [over.built]p13: 4715 // 4716 // For every cv-qualified or cv-unqualified object type T 4717 // there exist candidate operator functions of the form 4718 // 4719 // T* operator+(T*, ptrdiff_t); 4720 // T& operator[](T*, ptrdiff_t); [BELOW] 4721 // T* operator-(T*, ptrdiff_t); 4722 // T* operator+(ptrdiff_t, T*); 4723 // T& operator[](ptrdiff_t, T*); [BELOW] 4724 // 4725 // C++ [over.built]p14: 4726 // 4727 // For every T, where T is a pointer to object type, there 4728 // exist candidate operator functions of the form 4729 // 4730 // ptrdiff_t operator-(T, T); 4731 for (BuiltinCandidateTypeSet::iterator Ptr 4732 = CandidateTypes.pointer_begin(); 4733 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4734 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 4735 4736 // operator+(T*, ptrdiff_t) or operator-(T*, ptrdiff_t) 4737 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 4738 4739 if (Op == OO_Plus) { 4740 // T* operator+(ptrdiff_t, T*); 4741 ParamTypes[0] = ParamTypes[1]; 4742 ParamTypes[1] = *Ptr; 4743 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 4744 } else { 4745 // ptrdiff_t operator-(T, T); 4746 ParamTypes[1] = *Ptr; 4747 AddBuiltinCandidate(Context.getPointerDiffType(), ParamTypes, 4748 Args, 2, CandidateSet); 4749 } 4750 } 4751 } 4752 // Fall through 4753 4754 case OO_Slash: 4755 BinaryStar: 4756 Conditional: 4757 // C++ [over.built]p12: 4758 // 4759 // For every pair of promoted arithmetic types L and R, there 4760 // exist candidate operator functions of the form 4761 // 4762 // LR operator*(L, R); 4763 // LR operator/(L, R); 4764 // LR operator+(L, R); 4765 // LR operator-(L, R); 4766 // bool operator<(L, R); 4767 // bool operator>(L, R); 4768 // bool operator<=(L, R); 4769 // bool operator>=(L, R); 4770 // bool operator==(L, R); 4771 // bool operator!=(L, R); 4772 // 4773 // where LR is the result of the usual arithmetic conversions 4774 // between types L and R. 4775 // 4776 // C++ [over.built]p24: 4777 // 4778 // For every pair of promoted arithmetic types L and R, there exist 4779 // candidate operator functions of the form 4780 // 4781 // LR operator?(bool, L, R); 4782 // 4783 // where LR is the result of the usual arithmetic conversions 4784 // between types L and R. 4785 // Our candidates ignore the first parameter. 4786 for (unsigned Left = FirstPromotedArithmeticType; 4787 Left < LastPromotedArithmeticType; ++Left) { 4788 for (unsigned Right = FirstPromotedArithmeticType; 4789 Right < LastPromotedArithmeticType; ++Right) { 4790 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 4791 QualType Result 4792 = isComparison 4793 ? Context.BoolTy 4794 : Context.UsualArithmeticConversionsType(LandR[0], LandR[1]); 4795 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 4796 } 4797 } 4798 4799 // Extension: Add the binary operators ==, !=, <, <=, >=, >, *, /, and the 4800 // conditional operator for vector types. 4801 for (BuiltinCandidateTypeSet::iterator Vec1 = CandidateTypes.vector_begin(), 4802 Vec1End = CandidateTypes.vector_end(); 4803 Vec1 != Vec1End; ++Vec1) 4804 for (BuiltinCandidateTypeSet::iterator 4805 Vec2 = CandidateTypes.vector_begin(), 4806 Vec2End = CandidateTypes.vector_end(); 4807 Vec2 != Vec2End; ++Vec2) { 4808 QualType LandR[2] = { *Vec1, *Vec2 }; 4809 QualType Result; 4810 if (isComparison) 4811 Result = Context.BoolTy; 4812 else { 4813 if ((*Vec1)->isExtVectorType() || !(*Vec2)->isExtVectorType()) 4814 Result = *Vec1; 4815 else 4816 Result = *Vec2; 4817 } 4818 4819 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 4820 } 4821 4822 break; 4823 4824 case OO_Percent: 4825 BinaryAmp: 4826 case OO_Caret: 4827 case OO_Pipe: 4828 case OO_LessLess: 4829 case OO_GreaterGreater: 4830 // C++ [over.built]p17: 4831 // 4832 // For every pair of promoted integral types L and R, there 4833 // exist candidate operator functions of the form 4834 // 4835 // LR operator%(L, R); 4836 // LR operator&(L, R); 4837 // LR operator^(L, R); 4838 // LR operator|(L, R); 4839 // L operator<<(L, R); 4840 // L operator>>(L, R); 4841 // 4842 // where LR is the result of the usual arithmetic conversions 4843 // between types L and R. 4844 for (unsigned Left = FirstPromotedIntegralType; 4845 Left < LastPromotedIntegralType; ++Left) { 4846 for (unsigned Right = FirstPromotedIntegralType; 4847 Right < LastPromotedIntegralType; ++Right) { 4848 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 4849 QualType Result = (Op == OO_LessLess || Op == OO_GreaterGreater) 4850 ? LandR[0] 4851 : Context.UsualArithmeticConversionsType(LandR[0], LandR[1]); 4852 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 4853 } 4854 } 4855 break; 4856 4857 case OO_Equal: 4858 // C++ [over.built]p20: 4859 // 4860 // For every pair (T, VQ), where T is an enumeration or 4861 // pointer to member type and VQ is either volatile or 4862 // empty, there exist candidate operator functions of the form 4863 // 4864 // VQ T& operator=(VQ T&, T); 4865 for (BuiltinCandidateTypeSet::iterator 4866 Enum = CandidateTypes.enumeration_begin(), 4867 EnumEnd = CandidateTypes.enumeration_end(); 4868 Enum != EnumEnd; ++Enum) 4869 AddBuiltinAssignmentOperatorCandidates(*this, *Enum, Args, 2, 4870 CandidateSet); 4871 for (BuiltinCandidateTypeSet::iterator 4872 MemPtr = CandidateTypes.member_pointer_begin(), 4873 MemPtrEnd = CandidateTypes.member_pointer_end(); 4874 MemPtr != MemPtrEnd; ++MemPtr) 4875 AddBuiltinAssignmentOperatorCandidates(*this, *MemPtr, Args, 2, 4876 CandidateSet); 4877 4878 // Fall through. 4879 4880 case OO_PlusEqual: 4881 case OO_MinusEqual: 4882 // C++ [over.built]p19: 4883 // 4884 // For every pair (T, VQ), where T is any type and VQ is either 4885 // volatile or empty, there exist candidate operator functions 4886 // of the form 4887 // 4888 // T*VQ& operator=(T*VQ&, T*); 4889 // 4890 // C++ [over.built]p21: 4891 // 4892 // For every pair (T, VQ), where T is a cv-qualified or 4893 // cv-unqualified object type and VQ is either volatile or 4894 // empty, there exist candidate operator functions of the form 4895 // 4896 // T*VQ& operator+=(T*VQ&, ptrdiff_t); 4897 // T*VQ& operator-=(T*VQ&, ptrdiff_t); 4898 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 4899 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4900 QualType ParamTypes[2]; 4901 ParamTypes[1] = (Op == OO_Equal)? *Ptr : Context.getPointerDiffType(); 4902 4903 // non-volatile version 4904 ParamTypes[0] = Context.getLValueReferenceType(*Ptr); 4905 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4906 /*IsAssigmentOperator=*/Op == OO_Equal); 4907 4908 if (!Context.getCanonicalType(*Ptr).isVolatileQualified() && 4909 VisibleTypeConversionsQuals.hasVolatile()) { 4910 // volatile version 4911 ParamTypes[0] 4912 = Context.getLValueReferenceType(Context.getVolatileType(*Ptr)); 4913 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4914 /*IsAssigmentOperator=*/Op == OO_Equal); 4915 } 4916 } 4917 // Fall through. 4918 4919 case OO_StarEqual: 4920 case OO_SlashEqual: 4921 // C++ [over.built]p18: 4922 // 4923 // For every triple (L, VQ, R), where L is an arithmetic type, 4924 // VQ is either volatile or empty, and R is a promoted 4925 // arithmetic type, there exist candidate operator functions of 4926 // the form 4927 // 4928 // VQ L& operator=(VQ L&, R); 4929 // VQ L& operator*=(VQ L&, R); 4930 // VQ L& operator/=(VQ L&, R); 4931 // VQ L& operator+=(VQ L&, R); 4932 // VQ L& operator-=(VQ L&, R); 4933 for (unsigned Left = 0; Left < NumArithmeticTypes; ++Left) { 4934 for (unsigned Right = FirstPromotedArithmeticType; 4935 Right < LastPromotedArithmeticType; ++Right) { 4936 QualType ParamTypes[2]; 4937 ParamTypes[1] = ArithmeticTypes[Right]; 4938 4939 // Add this built-in operator as a candidate (VQ is empty). 4940 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 4941 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4942 /*IsAssigmentOperator=*/Op == OO_Equal); 4943 4944 // Add this built-in operator as a candidate (VQ is 'volatile'). 4945 if (VisibleTypeConversionsQuals.hasVolatile()) { 4946 ParamTypes[0] = Context.getVolatileType(ArithmeticTypes[Left]); 4947 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 4948 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4949 /*IsAssigmentOperator=*/Op == OO_Equal); 4950 } 4951 } 4952 } 4953 4954 // Extension: Add the binary operators =, +=, -=, *=, /= for vector types. 4955 for (BuiltinCandidateTypeSet::iterator Vec1 = CandidateTypes.vector_begin(), 4956 Vec1End = CandidateTypes.vector_end(); 4957 Vec1 != Vec1End; ++Vec1) 4958 for (BuiltinCandidateTypeSet::iterator 4959 Vec2 = CandidateTypes.vector_begin(), 4960 Vec2End = CandidateTypes.vector_end(); 4961 Vec2 != Vec2End; ++Vec2) { 4962 QualType ParamTypes[2]; 4963 ParamTypes[1] = *Vec2; 4964 // Add this built-in operator as a candidate (VQ is empty). 4965 ParamTypes[0] = Context.getLValueReferenceType(*Vec1); 4966 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4967 /*IsAssigmentOperator=*/Op == OO_Equal); 4968 4969 // Add this built-in operator as a candidate (VQ is 'volatile'). 4970 if (VisibleTypeConversionsQuals.hasVolatile()) { 4971 ParamTypes[0] = Context.getVolatileType(*Vec1); 4972 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 4973 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4974 /*IsAssigmentOperator=*/Op == OO_Equal); 4975 } 4976 } 4977 break; 4978 4979 case OO_PercentEqual: 4980 case OO_LessLessEqual: 4981 case OO_GreaterGreaterEqual: 4982 case OO_AmpEqual: 4983 case OO_CaretEqual: 4984 case OO_PipeEqual: 4985 // C++ [over.built]p22: 4986 // 4987 // For every triple (L, VQ, R), where L is an integral type, VQ 4988 // is either volatile or empty, and R is a promoted integral 4989 // type, there exist candidate operator functions of the form 4990 // 4991 // VQ L& operator%=(VQ L&, R); 4992 // VQ L& operator<<=(VQ L&, R); 4993 // VQ L& operator>>=(VQ L&, R); 4994 // VQ L& operator&=(VQ L&, R); 4995 // VQ L& operator^=(VQ L&, R); 4996 // VQ L& operator|=(VQ L&, R); 4997 for (unsigned Left = FirstIntegralType; Left < LastIntegralType; ++Left) { 4998 for (unsigned Right = FirstPromotedIntegralType; 4999 Right < LastPromotedIntegralType; ++Right) { 5000 QualType ParamTypes[2]; 5001 ParamTypes[1] = ArithmeticTypes[Right]; 5002 5003 // Add this built-in operator as a candidate (VQ is empty). 5004 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 5005 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 5006 if (VisibleTypeConversionsQuals.hasVolatile()) { 5007 // Add this built-in operator as a candidate (VQ is 'volatile'). 5008 ParamTypes[0] = ArithmeticTypes[Left]; 5009 ParamTypes[0] = Context.getVolatileType(ParamTypes[0]); 5010 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 5011 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 5012 } 5013 } 5014 } 5015 break; 5016 5017 case OO_Exclaim: { 5018 // C++ [over.operator]p23: 5019 // 5020 // There also exist candidate operator functions of the form 5021 // 5022 // bool operator!(bool); 5023 // bool operator&&(bool, bool); [BELOW] 5024 // bool operator||(bool, bool); [BELOW] 5025 QualType ParamTy = Context.BoolTy; 5026 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet, 5027 /*IsAssignmentOperator=*/false, 5028 /*NumContextualBoolArguments=*/1); 5029 break; 5030 } 5031 5032 case OO_AmpAmp: 5033 case OO_PipePipe: { 5034 // C++ [over.operator]p23: 5035 // 5036 // There also exist candidate operator functions of the form 5037 // 5038 // bool operator!(bool); [ABOVE] 5039 // bool operator&&(bool, bool); 5040 // bool operator||(bool, bool); 5041 QualType ParamTypes[2] = { Context.BoolTy, Context.BoolTy }; 5042 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet, 5043 /*IsAssignmentOperator=*/false, 5044 /*NumContextualBoolArguments=*/2); 5045 break; 5046 } 5047 5048 case OO_Subscript: 5049 // C++ [over.built]p13: 5050 // 5051 // For every cv-qualified or cv-unqualified object type T there 5052 // exist candidate operator functions of the form 5053 // 5054 // T* operator+(T*, ptrdiff_t); [ABOVE] 5055 // T& operator[](T*, ptrdiff_t); 5056 // T* operator-(T*, ptrdiff_t); [ABOVE] 5057 // T* operator+(ptrdiff_t, T*); [ABOVE] 5058 // T& operator[](ptrdiff_t, T*); 5059 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 5060 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 5061 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 5062 QualType PointeeType = (*Ptr)->getAs<PointerType>()->getPointeeType(); 5063 QualType ResultTy = Context.getLValueReferenceType(PointeeType); 5064 5065 // T& operator[](T*, ptrdiff_t) 5066 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 5067 5068 // T& operator[](ptrdiff_t, T*); 5069 ParamTypes[0] = ParamTypes[1]; 5070 ParamTypes[1] = *Ptr; 5071 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 5072 } 5073 break; 5074 5075 case OO_ArrowStar: 5076 // C++ [over.built]p11: 5077 // For every quintuple (C1, C2, T, CV1, CV2), where C2 is a class type, 5078 // C1 is the same type as C2 or is a derived class of C2, T is an object 5079 // type or a function type, and CV1 and CV2 are cv-qualifier-seqs, 5080 // there exist candidate operator functions of the form 5081 // CV12 T& operator->*(CV1 C1*, CV2 T C2::*); 5082 // where CV12 is the union of CV1 and CV2. 5083 { 5084 for (BuiltinCandidateTypeSet::iterator Ptr = 5085 CandidateTypes.pointer_begin(); 5086 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 5087 QualType C1Ty = (*Ptr); 5088 QualType C1; 5089 QualifierCollector Q1; 5090 if (const PointerType *PointerTy = C1Ty->getAs<PointerType>()) { 5091 C1 = QualType(Q1.strip(PointerTy->getPointeeType()), 0); 5092 if (!isa<RecordType>(C1)) 5093 continue; 5094 // heuristic to reduce number of builtin candidates in the set. 5095 // Add volatile/restrict version only if there are conversions to a 5096 // volatile/restrict type. 5097 if (!VisibleTypeConversionsQuals.hasVolatile() && Q1.hasVolatile()) 5098 continue; 5099 if (!VisibleTypeConversionsQuals.hasRestrict() && Q1.hasRestrict()) 5100 continue; 5101 } 5102 for (BuiltinCandidateTypeSet::iterator 5103 MemPtr = CandidateTypes.member_pointer_begin(), 5104 MemPtrEnd = CandidateTypes.member_pointer_end(); 5105 MemPtr != MemPtrEnd; ++MemPtr) { 5106 const MemberPointerType *mptr = cast<MemberPointerType>(*MemPtr); 5107 QualType C2 = QualType(mptr->getClass(), 0); 5108 C2 = C2.getUnqualifiedType(); 5109 if (C1 != C2 && !IsDerivedFrom(C1, C2)) 5110 break; 5111 QualType ParamTypes[2] = { *Ptr, *MemPtr }; 5112 // build CV12 T& 5113 QualType T = mptr->getPointeeType(); 5114 if (!VisibleTypeConversionsQuals.hasVolatile() && 5115 T.isVolatileQualified()) 5116 continue; 5117 if (!VisibleTypeConversionsQuals.hasRestrict() && 5118 T.isRestrictQualified()) 5119 continue; 5120 T = Q1.apply(T); 5121 QualType ResultTy = Context.getLValueReferenceType(T); 5122 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 5123 } 5124 } 5125 } 5126 break; 5127 5128 case OO_Conditional: 5129 // Note that we don't consider the first argument, since it has been 5130 // contextually converted to bool long ago. The candidates below are 5131 // therefore added as binary. 5132 // 5133 // C++ [over.built]p24: 5134 // For every type T, where T is a pointer or pointer-to-member type, 5135 // there exist candidate operator functions of the form 5136 // 5137 // T operator?(bool, T, T); 5138 // 5139 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(), 5140 E = CandidateTypes.pointer_end(); Ptr != E; ++Ptr) { 5141 QualType ParamTypes[2] = { *Ptr, *Ptr }; 5142 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 5143 } 5144 for (BuiltinCandidateTypeSet::iterator Ptr = 5145 CandidateTypes.member_pointer_begin(), 5146 E = CandidateTypes.member_pointer_end(); Ptr != E; ++Ptr) { 5147 QualType ParamTypes[2] = { *Ptr, *Ptr }; 5148 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 5149 } 5150 goto Conditional; 5151 } 5152} 5153 5154/// \brief Add function candidates found via argument-dependent lookup 5155/// to the set of overloading candidates. 5156/// 5157/// This routine performs argument-dependent name lookup based on the 5158/// given function name (which may also be an operator name) and adds 5159/// all of the overload candidates found by ADL to the overload 5160/// candidate set (C++ [basic.lookup.argdep]). 5161void 5162Sema::AddArgumentDependentLookupCandidates(DeclarationName Name, 5163 bool Operator, 5164 Expr **Args, unsigned NumArgs, 5165 const TemplateArgumentListInfo *ExplicitTemplateArgs, 5166 OverloadCandidateSet& CandidateSet, 5167 bool PartialOverloading) { 5168 ADLResult Fns; 5169 5170 // FIXME: This approach for uniquing ADL results (and removing 5171 // redundant candidates from the set) relies on pointer-equality, 5172 // which means we need to key off the canonical decl. However, 5173 // always going back to the canonical decl might not get us the 5174 // right set of default arguments. What default arguments are 5175 // we supposed to consider on ADL candidates, anyway? 5176 5177 // FIXME: Pass in the explicit template arguments? 5178 ArgumentDependentLookup(Name, Operator, Args, NumArgs, Fns); 5179 5180 // Erase all of the candidates we already knew about. 5181 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 5182 CandEnd = CandidateSet.end(); 5183 Cand != CandEnd; ++Cand) 5184 if (Cand->Function) { 5185 Fns.erase(Cand->Function); 5186 if (FunctionTemplateDecl *FunTmpl = Cand->Function->getPrimaryTemplate()) 5187 Fns.erase(FunTmpl); 5188 } 5189 5190 // For each of the ADL candidates we found, add it to the overload 5191 // set. 5192 for (ADLResult::iterator I = Fns.begin(), E = Fns.end(); I != E; ++I) { 5193 DeclAccessPair FoundDecl = DeclAccessPair::make(*I, AS_none); 5194 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*I)) { 5195 if (ExplicitTemplateArgs) 5196 continue; 5197 5198 AddOverloadCandidate(FD, FoundDecl, Args, NumArgs, CandidateSet, 5199 false, PartialOverloading); 5200 } else 5201 AddTemplateOverloadCandidate(cast<FunctionTemplateDecl>(*I), 5202 FoundDecl, ExplicitTemplateArgs, 5203 Args, NumArgs, CandidateSet); 5204 } 5205} 5206 5207/// isBetterOverloadCandidate - Determines whether the first overload 5208/// candidate is a better candidate than the second (C++ 13.3.3p1). 5209bool 5210Sema::isBetterOverloadCandidate(const OverloadCandidate& Cand1, 5211 const OverloadCandidate& Cand2, 5212 SourceLocation Loc) { 5213 // Define viable functions to be better candidates than non-viable 5214 // functions. 5215 if (!Cand2.Viable) 5216 return Cand1.Viable; 5217 else if (!Cand1.Viable) 5218 return false; 5219 5220 // C++ [over.match.best]p1: 5221 // 5222 // -- if F is a static member function, ICS1(F) is defined such 5223 // that ICS1(F) is neither better nor worse than ICS1(G) for 5224 // any function G, and, symmetrically, ICS1(G) is neither 5225 // better nor worse than ICS1(F). 5226 unsigned StartArg = 0; 5227 if (Cand1.IgnoreObjectArgument || Cand2.IgnoreObjectArgument) 5228 StartArg = 1; 5229 5230 // C++ [over.match.best]p1: 5231 // A viable function F1 is defined to be a better function than another 5232 // viable function F2 if for all arguments i, ICSi(F1) is not a worse 5233 // conversion sequence than ICSi(F2), and then... 5234 unsigned NumArgs = Cand1.Conversions.size(); 5235 assert(Cand2.Conversions.size() == NumArgs && "Overload candidate mismatch"); 5236 bool HasBetterConversion = false; 5237 for (unsigned ArgIdx = StartArg; ArgIdx < NumArgs; ++ArgIdx) { 5238 switch (CompareImplicitConversionSequences(Cand1.Conversions[ArgIdx], 5239 Cand2.Conversions[ArgIdx])) { 5240 case ImplicitConversionSequence::Better: 5241 // Cand1 has a better conversion sequence. 5242 HasBetterConversion = true; 5243 break; 5244 5245 case ImplicitConversionSequence::Worse: 5246 // Cand1 can't be better than Cand2. 5247 return false; 5248 5249 case ImplicitConversionSequence::Indistinguishable: 5250 // Do nothing. 5251 break; 5252 } 5253 } 5254 5255 // -- for some argument j, ICSj(F1) is a better conversion sequence than 5256 // ICSj(F2), or, if not that, 5257 if (HasBetterConversion) 5258 return true; 5259 5260 // - F1 is a non-template function and F2 is a function template 5261 // specialization, or, if not that, 5262 if ((!Cand1.Function || !Cand1.Function->getPrimaryTemplate()) && 5263 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 5264 return true; 5265 5266 // -- F1 and F2 are function template specializations, and the function 5267 // template for F1 is more specialized than the template for F2 5268 // according to the partial ordering rules described in 14.5.5.2, or, 5269 // if not that, 5270 if (Cand1.Function && Cand1.Function->getPrimaryTemplate() && 5271 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 5272 if (FunctionTemplateDecl *BetterTemplate 5273 = getMoreSpecializedTemplate(Cand1.Function->getPrimaryTemplate(), 5274 Cand2.Function->getPrimaryTemplate(), 5275 Loc, 5276 isa<CXXConversionDecl>(Cand1.Function)? TPOC_Conversion 5277 : TPOC_Call)) 5278 return BetterTemplate == Cand1.Function->getPrimaryTemplate(); 5279 5280 // -- the context is an initialization by user-defined conversion 5281 // (see 8.5, 13.3.1.5) and the standard conversion sequence 5282 // from the return type of F1 to the destination type (i.e., 5283 // the type of the entity being initialized) is a better 5284 // conversion sequence than the standard conversion sequence 5285 // from the return type of F2 to the destination type. 5286 if (Cand1.Function && Cand2.Function && 5287 isa<CXXConversionDecl>(Cand1.Function) && 5288 isa<CXXConversionDecl>(Cand2.Function)) { 5289 switch (CompareStandardConversionSequences(Cand1.FinalConversion, 5290 Cand2.FinalConversion)) { 5291 case ImplicitConversionSequence::Better: 5292 // Cand1 has a better conversion sequence. 5293 return true; 5294 5295 case ImplicitConversionSequence::Worse: 5296 // Cand1 can't be better than Cand2. 5297 return false; 5298 5299 case ImplicitConversionSequence::Indistinguishable: 5300 // Do nothing 5301 break; 5302 } 5303 } 5304 5305 return false; 5306} 5307 5308/// \brief Computes the best viable function (C++ 13.3.3) 5309/// within an overload candidate set. 5310/// 5311/// \param CandidateSet the set of candidate functions. 5312/// 5313/// \param Loc the location of the function name (or operator symbol) for 5314/// which overload resolution occurs. 5315/// 5316/// \param Best f overload resolution was successful or found a deleted 5317/// function, Best points to the candidate function found. 5318/// 5319/// \returns The result of overload resolution. 5320OverloadingResult Sema::BestViableFunction(OverloadCandidateSet& CandidateSet, 5321 SourceLocation Loc, 5322 OverloadCandidateSet::iterator& Best) { 5323 // Find the best viable function. 5324 Best = CandidateSet.end(); 5325 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 5326 Cand != CandidateSet.end(); ++Cand) { 5327 if (Cand->Viable) { 5328 if (Best == CandidateSet.end() || 5329 isBetterOverloadCandidate(*Cand, *Best, Loc)) 5330 Best = Cand; 5331 } 5332 } 5333 5334 // If we didn't find any viable functions, abort. 5335 if (Best == CandidateSet.end()) 5336 return OR_No_Viable_Function; 5337 5338 // Make sure that this function is better than every other viable 5339 // function. If not, we have an ambiguity. 5340 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 5341 Cand != CandidateSet.end(); ++Cand) { 5342 if (Cand->Viable && 5343 Cand != Best && 5344 !isBetterOverloadCandidate(*Best, *Cand, Loc)) { 5345 Best = CandidateSet.end(); 5346 return OR_Ambiguous; 5347 } 5348 } 5349 5350 // Best is the best viable function. 5351 if (Best->Function && 5352 (Best->Function->isDeleted() || 5353 Best->Function->getAttr<UnavailableAttr>())) 5354 return OR_Deleted; 5355 5356 // C++ [basic.def.odr]p2: 5357 // An overloaded function is used if it is selected by overload resolution 5358 // when referred to from a potentially-evaluated expression. [Note: this 5359 // covers calls to named functions (5.2.2), operator overloading 5360 // (clause 13), user-defined conversions (12.3.2), allocation function for 5361 // placement new (5.3.4), as well as non-default initialization (8.5). 5362 if (Best->Function) 5363 MarkDeclarationReferenced(Loc, Best->Function); 5364 return OR_Success; 5365} 5366 5367namespace { 5368 5369enum OverloadCandidateKind { 5370 oc_function, 5371 oc_method, 5372 oc_constructor, 5373 oc_function_template, 5374 oc_method_template, 5375 oc_constructor_template, 5376 oc_implicit_default_constructor, 5377 oc_implicit_copy_constructor, 5378 oc_implicit_copy_assignment 5379}; 5380 5381OverloadCandidateKind ClassifyOverloadCandidate(Sema &S, 5382 FunctionDecl *Fn, 5383 std::string &Description) { 5384 bool isTemplate = false; 5385 5386 if (FunctionTemplateDecl *FunTmpl = Fn->getPrimaryTemplate()) { 5387 isTemplate = true; 5388 Description = S.getTemplateArgumentBindingsText( 5389 FunTmpl->getTemplateParameters(), *Fn->getTemplateSpecializationArgs()); 5390 } 5391 5392 if (CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(Fn)) { 5393 if (!Ctor->isImplicit()) 5394 return isTemplate ? oc_constructor_template : oc_constructor; 5395 5396 return Ctor->isCopyConstructor() ? oc_implicit_copy_constructor 5397 : oc_implicit_default_constructor; 5398 } 5399 5400 if (CXXMethodDecl *Meth = dyn_cast<CXXMethodDecl>(Fn)) { 5401 // This actually gets spelled 'candidate function' for now, but 5402 // it doesn't hurt to split it out. 5403 if (!Meth->isImplicit()) 5404 return isTemplate ? oc_method_template : oc_method; 5405 5406 assert(Meth->isCopyAssignment() 5407 && "implicit method is not copy assignment operator?"); 5408 return oc_implicit_copy_assignment; 5409 } 5410 5411 return isTemplate ? oc_function_template : oc_function; 5412} 5413 5414} // end anonymous namespace 5415 5416// Notes the location of an overload candidate. 5417void Sema::NoteOverloadCandidate(FunctionDecl *Fn) { 5418 std::string FnDesc; 5419 OverloadCandidateKind K = ClassifyOverloadCandidate(*this, Fn, FnDesc); 5420 Diag(Fn->getLocation(), diag::note_ovl_candidate) 5421 << (unsigned) K << FnDesc; 5422} 5423 5424/// Diagnoses an ambiguous conversion. The partial diagnostic is the 5425/// "lead" diagnostic; it will be given two arguments, the source and 5426/// target types of the conversion. 5427void Sema::DiagnoseAmbiguousConversion(const ImplicitConversionSequence &ICS, 5428 SourceLocation CaretLoc, 5429 const PartialDiagnostic &PDiag) { 5430 Diag(CaretLoc, PDiag) 5431 << ICS.Ambiguous.getFromType() << ICS.Ambiguous.getToType(); 5432 for (AmbiguousConversionSequence::const_iterator 5433 I = ICS.Ambiguous.begin(), E = ICS.Ambiguous.end(); I != E; ++I) { 5434 NoteOverloadCandidate(*I); 5435 } 5436} 5437 5438namespace { 5439 5440void DiagnoseBadConversion(Sema &S, OverloadCandidate *Cand, unsigned I) { 5441 const ImplicitConversionSequence &Conv = Cand->Conversions[I]; 5442 assert(Conv.isBad()); 5443 assert(Cand->Function && "for now, candidate must be a function"); 5444 FunctionDecl *Fn = Cand->Function; 5445 5446 // There's a conversion slot for the object argument if this is a 5447 // non-constructor method. Note that 'I' corresponds the 5448 // conversion-slot index. 5449 bool isObjectArgument = false; 5450 if (isa<CXXMethodDecl>(Fn) && !isa<CXXConstructorDecl>(Fn)) { 5451 if (I == 0) 5452 isObjectArgument = true; 5453 else 5454 I--; 5455 } 5456 5457 std::string FnDesc; 5458 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, FnDesc); 5459 5460 Expr *FromExpr = Conv.Bad.FromExpr; 5461 QualType FromTy = Conv.Bad.getFromType(); 5462 QualType ToTy = Conv.Bad.getToType(); 5463 5464 if (FromTy == S.Context.OverloadTy) { 5465 assert(FromExpr && "overload set argument came from implicit argument?"); 5466 Expr *E = FromExpr->IgnoreParens(); 5467 if (isa<UnaryOperator>(E)) 5468 E = cast<UnaryOperator>(E)->getSubExpr()->IgnoreParens(); 5469 DeclarationName Name = cast<OverloadExpr>(E)->getName(); 5470 5471 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_overload) 5472 << (unsigned) FnKind << FnDesc 5473 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 5474 << ToTy << Name << I+1; 5475 return; 5476 } 5477 5478 // Do some hand-waving analysis to see if the non-viability is due 5479 // to a qualifier mismatch. 5480 CanQualType CFromTy = S.Context.getCanonicalType(FromTy); 5481 CanQualType CToTy = S.Context.getCanonicalType(ToTy); 5482 if (CanQual<ReferenceType> RT = CToTy->getAs<ReferenceType>()) 5483 CToTy = RT->getPointeeType(); 5484 else { 5485 // TODO: detect and diagnose the full richness of const mismatches. 5486 if (CanQual<PointerType> FromPT = CFromTy->getAs<PointerType>()) 5487 if (CanQual<PointerType> ToPT = CToTy->getAs<PointerType>()) 5488 CFromTy = FromPT->getPointeeType(), CToTy = ToPT->getPointeeType(); 5489 } 5490 5491 if (CToTy.getUnqualifiedType() == CFromTy.getUnqualifiedType() && 5492 !CToTy.isAtLeastAsQualifiedAs(CFromTy)) { 5493 // It is dumb that we have to do this here. 5494 while (isa<ArrayType>(CFromTy)) 5495 CFromTy = CFromTy->getAs<ArrayType>()->getElementType(); 5496 while (isa<ArrayType>(CToTy)) 5497 CToTy = CFromTy->getAs<ArrayType>()->getElementType(); 5498 5499 Qualifiers FromQs = CFromTy.getQualifiers(); 5500 Qualifiers ToQs = CToTy.getQualifiers(); 5501 5502 if (FromQs.getAddressSpace() != ToQs.getAddressSpace()) { 5503 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_addrspace) 5504 << (unsigned) FnKind << FnDesc 5505 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 5506 << FromTy 5507 << FromQs.getAddressSpace() << ToQs.getAddressSpace() 5508 << (unsigned) isObjectArgument << I+1; 5509 return; 5510 } 5511 5512 unsigned CVR = FromQs.getCVRQualifiers() & ~ToQs.getCVRQualifiers(); 5513 assert(CVR && "unexpected qualifiers mismatch"); 5514 5515 if (isObjectArgument) { 5516 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr_this) 5517 << (unsigned) FnKind << FnDesc 5518 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 5519 << FromTy << (CVR - 1); 5520 } else { 5521 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr) 5522 << (unsigned) FnKind << FnDesc 5523 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 5524 << FromTy << (CVR - 1) << I+1; 5525 } 5526 return; 5527 } 5528 5529 // Diagnose references or pointers to incomplete types differently, 5530 // since it's far from impossible that the incompleteness triggered 5531 // the failure. 5532 QualType TempFromTy = FromTy.getNonReferenceType(); 5533 if (const PointerType *PTy = TempFromTy->getAs<PointerType>()) 5534 TempFromTy = PTy->getPointeeType(); 5535 if (TempFromTy->isIncompleteType()) { 5536 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_conv_incomplete) 5537 << (unsigned) FnKind << FnDesc 5538 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 5539 << FromTy << ToTy << (unsigned) isObjectArgument << I+1; 5540 return; 5541 } 5542 5543 // Diagnose base -> derived pointer conversions. 5544 unsigned BaseToDerivedConversion = 0; 5545 if (const PointerType *FromPtrTy = FromTy->getAs<PointerType>()) { 5546 if (const PointerType *ToPtrTy = ToTy->getAs<PointerType>()) { 5547 if (ToPtrTy->getPointeeType().isAtLeastAsQualifiedAs( 5548 FromPtrTy->getPointeeType()) && 5549 !FromPtrTy->getPointeeType()->isIncompleteType() && 5550 !ToPtrTy->getPointeeType()->isIncompleteType() && 5551 S.IsDerivedFrom(ToPtrTy->getPointeeType(), 5552 FromPtrTy->getPointeeType())) 5553 BaseToDerivedConversion = 1; 5554 } 5555 } else if (const ObjCObjectPointerType *FromPtrTy 5556 = FromTy->getAs<ObjCObjectPointerType>()) { 5557 if (const ObjCObjectPointerType *ToPtrTy 5558 = ToTy->getAs<ObjCObjectPointerType>()) 5559 if (const ObjCInterfaceDecl *FromIface = FromPtrTy->getInterfaceDecl()) 5560 if (const ObjCInterfaceDecl *ToIface = ToPtrTy->getInterfaceDecl()) 5561 if (ToPtrTy->getPointeeType().isAtLeastAsQualifiedAs( 5562 FromPtrTy->getPointeeType()) && 5563 FromIface->isSuperClassOf(ToIface)) 5564 BaseToDerivedConversion = 2; 5565 } else if (const ReferenceType *ToRefTy = ToTy->getAs<ReferenceType>()) { 5566 if (ToRefTy->getPointeeType().isAtLeastAsQualifiedAs(FromTy) && 5567 !FromTy->isIncompleteType() && 5568 !ToRefTy->getPointeeType()->isIncompleteType() && 5569 S.IsDerivedFrom(ToRefTy->getPointeeType(), FromTy)) 5570 BaseToDerivedConversion = 3; 5571 } 5572 5573 if (BaseToDerivedConversion) { 5574 S.Diag(Fn->getLocation(), 5575 diag::note_ovl_candidate_bad_base_to_derived_conv) 5576 << (unsigned) FnKind << FnDesc 5577 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 5578 << (BaseToDerivedConversion - 1) 5579 << FromTy << ToTy << I+1; 5580 return; 5581 } 5582 5583 // TODO: specialize more based on the kind of mismatch 5584 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_conv) 5585 << (unsigned) FnKind << FnDesc 5586 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 5587 << FromTy << ToTy << (unsigned) isObjectArgument << I+1; 5588} 5589 5590void DiagnoseArityMismatch(Sema &S, OverloadCandidate *Cand, 5591 unsigned NumFormalArgs) { 5592 // TODO: treat calls to a missing default constructor as a special case 5593 5594 FunctionDecl *Fn = Cand->Function; 5595 const FunctionProtoType *FnTy = Fn->getType()->getAs<FunctionProtoType>(); 5596 5597 unsigned MinParams = Fn->getMinRequiredArguments(); 5598 5599 // at least / at most / exactly 5600 // FIXME: variadic templates "at most" should account for parameter packs 5601 unsigned mode, modeCount; 5602 if (NumFormalArgs < MinParams) { 5603 assert((Cand->FailureKind == ovl_fail_too_few_arguments) || 5604 (Cand->FailureKind == ovl_fail_bad_deduction && 5605 Cand->DeductionFailure.Result == Sema::TDK_TooFewArguments)); 5606 if (MinParams != FnTy->getNumArgs() || FnTy->isVariadic()) 5607 mode = 0; // "at least" 5608 else 5609 mode = 2; // "exactly" 5610 modeCount = MinParams; 5611 } else { 5612 assert((Cand->FailureKind == ovl_fail_too_many_arguments) || 5613 (Cand->FailureKind == ovl_fail_bad_deduction && 5614 Cand->DeductionFailure.Result == Sema::TDK_TooManyArguments)); 5615 if (MinParams != FnTy->getNumArgs()) 5616 mode = 1; // "at most" 5617 else 5618 mode = 2; // "exactly" 5619 modeCount = FnTy->getNumArgs(); 5620 } 5621 5622 std::string Description; 5623 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, Description); 5624 5625 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_arity) 5626 << (unsigned) FnKind << (Fn->getDescribedFunctionTemplate() != 0) << mode 5627 << modeCount << NumFormalArgs; 5628} 5629 5630/// Diagnose a failed template-argument deduction. 5631void DiagnoseBadDeduction(Sema &S, OverloadCandidate *Cand, 5632 Expr **Args, unsigned NumArgs) { 5633 FunctionDecl *Fn = Cand->Function; // pattern 5634 5635 TemplateParameter Param = Cand->DeductionFailure.getTemplateParameter(); 5636 NamedDecl *ParamD; 5637 (ParamD = Param.dyn_cast<TemplateTypeParmDecl*>()) || 5638 (ParamD = Param.dyn_cast<NonTypeTemplateParmDecl*>()) || 5639 (ParamD = Param.dyn_cast<TemplateTemplateParmDecl*>()); 5640 switch (Cand->DeductionFailure.Result) { 5641 case Sema::TDK_Success: 5642 llvm_unreachable("TDK_success while diagnosing bad deduction"); 5643 5644 case Sema::TDK_Incomplete: { 5645 assert(ParamD && "no parameter found for incomplete deduction result"); 5646 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_incomplete_deduction) 5647 << ParamD->getDeclName(); 5648 return; 5649 } 5650 5651 case Sema::TDK_Underqualified: { 5652 assert(ParamD && "no parameter found for bad qualifiers deduction result"); 5653 TemplateTypeParmDecl *TParam = cast<TemplateTypeParmDecl>(ParamD); 5654 5655 QualType Param = Cand->DeductionFailure.getFirstArg()->getAsType(); 5656 5657 // Param will have been canonicalized, but it should just be a 5658 // qualified version of ParamD, so move the qualifiers to that. 5659 QualifierCollector Qs(S.Context); 5660 Qs.strip(Param); 5661 QualType NonCanonParam = Qs.apply(TParam->getTypeForDecl()); 5662 assert(S.Context.hasSameType(Param, NonCanonParam)); 5663 5664 // Arg has also been canonicalized, but there's nothing we can do 5665 // about that. It also doesn't matter as much, because it won't 5666 // have any template parameters in it (because deduction isn't 5667 // done on dependent types). 5668 QualType Arg = Cand->DeductionFailure.getSecondArg()->getAsType(); 5669 5670 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_underqualified) 5671 << ParamD->getDeclName() << Arg << NonCanonParam; 5672 return; 5673 } 5674 5675 case Sema::TDK_Inconsistent: { 5676 assert(ParamD && "no parameter found for inconsistent deduction result"); 5677 int which = 0; 5678 if (isa<TemplateTypeParmDecl>(ParamD)) 5679 which = 0; 5680 else if (isa<NonTypeTemplateParmDecl>(ParamD)) 5681 which = 1; 5682 else { 5683 which = 2; 5684 } 5685 5686 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_inconsistent_deduction) 5687 << which << ParamD->getDeclName() 5688 << *Cand->DeductionFailure.getFirstArg() 5689 << *Cand->DeductionFailure.getSecondArg(); 5690 return; 5691 } 5692 5693 case Sema::TDK_InvalidExplicitArguments: 5694 assert(ParamD && "no parameter found for invalid explicit arguments"); 5695 if (ParamD->getDeclName()) 5696 S.Diag(Fn->getLocation(), 5697 diag::note_ovl_candidate_explicit_arg_mismatch_named) 5698 << ParamD->getDeclName(); 5699 else { 5700 int index = 0; 5701 if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(ParamD)) 5702 index = TTP->getIndex(); 5703 else if (NonTypeTemplateParmDecl *NTTP 5704 = dyn_cast<NonTypeTemplateParmDecl>(ParamD)) 5705 index = NTTP->getIndex(); 5706 else 5707 index = cast<TemplateTemplateParmDecl>(ParamD)->getIndex(); 5708 S.Diag(Fn->getLocation(), 5709 diag::note_ovl_candidate_explicit_arg_mismatch_unnamed) 5710 << (index + 1); 5711 } 5712 return; 5713 5714 case Sema::TDK_TooManyArguments: 5715 case Sema::TDK_TooFewArguments: 5716 DiagnoseArityMismatch(S, Cand, NumArgs); 5717 return; 5718 5719 case Sema::TDK_InstantiationDepth: 5720 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_instantiation_depth); 5721 return; 5722 5723 case Sema::TDK_SubstitutionFailure: { 5724 std::string ArgString; 5725 if (TemplateArgumentList *Args 5726 = Cand->DeductionFailure.getTemplateArgumentList()) 5727 ArgString = S.getTemplateArgumentBindingsText( 5728 Fn->getDescribedFunctionTemplate()->getTemplateParameters(), 5729 *Args); 5730 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_substitution_failure) 5731 << ArgString; 5732 return; 5733 } 5734 5735 // TODO: diagnose these individually, then kill off 5736 // note_ovl_candidate_bad_deduction, which is uselessly vague. 5737 case Sema::TDK_NonDeducedMismatch: 5738 case Sema::TDK_FailedOverloadResolution: 5739 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_deduction); 5740 return; 5741 } 5742} 5743 5744/// Generates a 'note' diagnostic for an overload candidate. We've 5745/// already generated a primary error at the call site. 5746/// 5747/// It really does need to be a single diagnostic with its caret 5748/// pointed at the candidate declaration. Yes, this creates some 5749/// major challenges of technical writing. Yes, this makes pointing 5750/// out problems with specific arguments quite awkward. It's still 5751/// better than generating twenty screens of text for every failed 5752/// overload. 5753/// 5754/// It would be great to be able to express per-candidate problems 5755/// more richly for those diagnostic clients that cared, but we'd 5756/// still have to be just as careful with the default diagnostics. 5757void NoteFunctionCandidate(Sema &S, OverloadCandidate *Cand, 5758 Expr **Args, unsigned NumArgs) { 5759 FunctionDecl *Fn = Cand->Function; 5760 5761 // Note deleted candidates, but only if they're viable. 5762 if (Cand->Viable && (Fn->isDeleted() || Fn->hasAttr<UnavailableAttr>())) { 5763 std::string FnDesc; 5764 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, FnDesc); 5765 5766 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_deleted) 5767 << FnKind << FnDesc << Fn->isDeleted(); 5768 return; 5769 } 5770 5771 // We don't really have anything else to say about viable candidates. 5772 if (Cand->Viable) { 5773 S.NoteOverloadCandidate(Fn); 5774 return; 5775 } 5776 5777 switch (Cand->FailureKind) { 5778 case ovl_fail_too_many_arguments: 5779 case ovl_fail_too_few_arguments: 5780 return DiagnoseArityMismatch(S, Cand, NumArgs); 5781 5782 case ovl_fail_bad_deduction: 5783 return DiagnoseBadDeduction(S, Cand, Args, NumArgs); 5784 5785 case ovl_fail_trivial_conversion: 5786 case ovl_fail_bad_final_conversion: 5787 case ovl_fail_final_conversion_not_exact: 5788 return S.NoteOverloadCandidate(Fn); 5789 5790 case ovl_fail_bad_conversion: { 5791 unsigned I = (Cand->IgnoreObjectArgument ? 1 : 0); 5792 for (unsigned N = Cand->Conversions.size(); I != N; ++I) 5793 if (Cand->Conversions[I].isBad()) 5794 return DiagnoseBadConversion(S, Cand, I); 5795 5796 // FIXME: this currently happens when we're called from SemaInit 5797 // when user-conversion overload fails. Figure out how to handle 5798 // those conditions and diagnose them well. 5799 return S.NoteOverloadCandidate(Fn); 5800 } 5801 } 5802} 5803 5804void NoteSurrogateCandidate(Sema &S, OverloadCandidate *Cand) { 5805 // Desugar the type of the surrogate down to a function type, 5806 // retaining as many typedefs as possible while still showing 5807 // the function type (and, therefore, its parameter types). 5808 QualType FnType = Cand->Surrogate->getConversionType(); 5809 bool isLValueReference = false; 5810 bool isRValueReference = false; 5811 bool isPointer = false; 5812 if (const LValueReferenceType *FnTypeRef = 5813 FnType->getAs<LValueReferenceType>()) { 5814 FnType = FnTypeRef->getPointeeType(); 5815 isLValueReference = true; 5816 } else if (const RValueReferenceType *FnTypeRef = 5817 FnType->getAs<RValueReferenceType>()) { 5818 FnType = FnTypeRef->getPointeeType(); 5819 isRValueReference = true; 5820 } 5821 if (const PointerType *FnTypePtr = FnType->getAs<PointerType>()) { 5822 FnType = FnTypePtr->getPointeeType(); 5823 isPointer = true; 5824 } 5825 // Desugar down to a function type. 5826 FnType = QualType(FnType->getAs<FunctionType>(), 0); 5827 // Reconstruct the pointer/reference as appropriate. 5828 if (isPointer) FnType = S.Context.getPointerType(FnType); 5829 if (isRValueReference) FnType = S.Context.getRValueReferenceType(FnType); 5830 if (isLValueReference) FnType = S.Context.getLValueReferenceType(FnType); 5831 5832 S.Diag(Cand->Surrogate->getLocation(), diag::note_ovl_surrogate_cand) 5833 << FnType; 5834} 5835 5836void NoteBuiltinOperatorCandidate(Sema &S, 5837 const char *Opc, 5838 SourceLocation OpLoc, 5839 OverloadCandidate *Cand) { 5840 assert(Cand->Conversions.size() <= 2 && "builtin operator is not binary"); 5841 std::string TypeStr("operator"); 5842 TypeStr += Opc; 5843 TypeStr += "("; 5844 TypeStr += Cand->BuiltinTypes.ParamTypes[0].getAsString(); 5845 if (Cand->Conversions.size() == 1) { 5846 TypeStr += ")"; 5847 S.Diag(OpLoc, diag::note_ovl_builtin_unary_candidate) << TypeStr; 5848 } else { 5849 TypeStr += ", "; 5850 TypeStr += Cand->BuiltinTypes.ParamTypes[1].getAsString(); 5851 TypeStr += ")"; 5852 S.Diag(OpLoc, diag::note_ovl_builtin_binary_candidate) << TypeStr; 5853 } 5854} 5855 5856void NoteAmbiguousUserConversions(Sema &S, SourceLocation OpLoc, 5857 OverloadCandidate *Cand) { 5858 unsigned NoOperands = Cand->Conversions.size(); 5859 for (unsigned ArgIdx = 0; ArgIdx < NoOperands; ++ArgIdx) { 5860 const ImplicitConversionSequence &ICS = Cand->Conversions[ArgIdx]; 5861 if (ICS.isBad()) break; // all meaningless after first invalid 5862 if (!ICS.isAmbiguous()) continue; 5863 5864 S.DiagnoseAmbiguousConversion(ICS, OpLoc, 5865 S.PDiag(diag::note_ambiguous_type_conversion)); 5866 } 5867} 5868 5869SourceLocation GetLocationForCandidate(const OverloadCandidate *Cand) { 5870 if (Cand->Function) 5871 return Cand->Function->getLocation(); 5872 if (Cand->IsSurrogate) 5873 return Cand->Surrogate->getLocation(); 5874 return SourceLocation(); 5875} 5876 5877struct CompareOverloadCandidatesForDisplay { 5878 Sema &S; 5879 CompareOverloadCandidatesForDisplay(Sema &S) : S(S) {} 5880 5881 bool operator()(const OverloadCandidate *L, 5882 const OverloadCandidate *R) { 5883 // Fast-path this check. 5884 if (L == R) return false; 5885 5886 // Order first by viability. 5887 if (L->Viable) { 5888 if (!R->Viable) return true; 5889 5890 // TODO: introduce a tri-valued comparison for overload 5891 // candidates. Would be more worthwhile if we had a sort 5892 // that could exploit it. 5893 if (S.isBetterOverloadCandidate(*L, *R, SourceLocation())) return true; 5894 if (S.isBetterOverloadCandidate(*R, *L, SourceLocation())) return false; 5895 } else if (R->Viable) 5896 return false; 5897 5898 assert(L->Viable == R->Viable); 5899 5900 // Criteria by which we can sort non-viable candidates: 5901 if (!L->Viable) { 5902 // 1. Arity mismatches come after other candidates. 5903 if (L->FailureKind == ovl_fail_too_many_arguments || 5904 L->FailureKind == ovl_fail_too_few_arguments) 5905 return false; 5906 if (R->FailureKind == ovl_fail_too_many_arguments || 5907 R->FailureKind == ovl_fail_too_few_arguments) 5908 return true; 5909 5910 // 2. Bad conversions come first and are ordered by the number 5911 // of bad conversions and quality of good conversions. 5912 if (L->FailureKind == ovl_fail_bad_conversion) { 5913 if (R->FailureKind != ovl_fail_bad_conversion) 5914 return true; 5915 5916 // If there's any ordering between the defined conversions... 5917 // FIXME: this might not be transitive. 5918 assert(L->Conversions.size() == R->Conversions.size()); 5919 5920 int leftBetter = 0; 5921 unsigned I = (L->IgnoreObjectArgument || R->IgnoreObjectArgument); 5922 for (unsigned E = L->Conversions.size(); I != E; ++I) { 5923 switch (S.CompareImplicitConversionSequences(L->Conversions[I], 5924 R->Conversions[I])) { 5925 case ImplicitConversionSequence::Better: 5926 leftBetter++; 5927 break; 5928 5929 case ImplicitConversionSequence::Worse: 5930 leftBetter--; 5931 break; 5932 5933 case ImplicitConversionSequence::Indistinguishable: 5934 break; 5935 } 5936 } 5937 if (leftBetter > 0) return true; 5938 if (leftBetter < 0) return false; 5939 5940 } else if (R->FailureKind == ovl_fail_bad_conversion) 5941 return false; 5942 5943 // TODO: others? 5944 } 5945 5946 // Sort everything else by location. 5947 SourceLocation LLoc = GetLocationForCandidate(L); 5948 SourceLocation RLoc = GetLocationForCandidate(R); 5949 5950 // Put candidates without locations (e.g. builtins) at the end. 5951 if (LLoc.isInvalid()) return false; 5952 if (RLoc.isInvalid()) return true; 5953 5954 return S.SourceMgr.isBeforeInTranslationUnit(LLoc, RLoc); 5955 } 5956}; 5957 5958/// CompleteNonViableCandidate - Normally, overload resolution only 5959/// computes up to the first 5960void CompleteNonViableCandidate(Sema &S, OverloadCandidate *Cand, 5961 Expr **Args, unsigned NumArgs) { 5962 assert(!Cand->Viable); 5963 5964 // Don't do anything on failures other than bad conversion. 5965 if (Cand->FailureKind != ovl_fail_bad_conversion) return; 5966 5967 // Skip forward to the first bad conversion. 5968 unsigned ConvIdx = (Cand->IgnoreObjectArgument ? 1 : 0); 5969 unsigned ConvCount = Cand->Conversions.size(); 5970 while (true) { 5971 assert(ConvIdx != ConvCount && "no bad conversion in candidate"); 5972 ConvIdx++; 5973 if (Cand->Conversions[ConvIdx - 1].isBad()) 5974 break; 5975 } 5976 5977 if (ConvIdx == ConvCount) 5978 return; 5979 5980 assert(!Cand->Conversions[ConvIdx].isInitialized() && 5981 "remaining conversion is initialized?"); 5982 5983 // FIXME: this should probably be preserved from the overload 5984 // operation somehow. 5985 bool SuppressUserConversions = false; 5986 5987 const FunctionProtoType* Proto; 5988 unsigned ArgIdx = ConvIdx; 5989 5990 if (Cand->IsSurrogate) { 5991 QualType ConvType 5992 = Cand->Surrogate->getConversionType().getNonReferenceType(); 5993 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 5994 ConvType = ConvPtrType->getPointeeType(); 5995 Proto = ConvType->getAs<FunctionProtoType>(); 5996 ArgIdx--; 5997 } else if (Cand->Function) { 5998 Proto = Cand->Function->getType()->getAs<FunctionProtoType>(); 5999 if (isa<CXXMethodDecl>(Cand->Function) && 6000 !isa<CXXConstructorDecl>(Cand->Function)) 6001 ArgIdx--; 6002 } else { 6003 // Builtin binary operator with a bad first conversion. 6004 assert(ConvCount <= 3); 6005 for (; ConvIdx != ConvCount; ++ConvIdx) 6006 Cand->Conversions[ConvIdx] 6007 = TryCopyInitialization(S, Args[ConvIdx], 6008 Cand->BuiltinTypes.ParamTypes[ConvIdx], 6009 SuppressUserConversions, 6010 /*InOverloadResolution*/ true); 6011 return; 6012 } 6013 6014 // Fill in the rest of the conversions. 6015 unsigned NumArgsInProto = Proto->getNumArgs(); 6016 for (; ConvIdx != ConvCount; ++ConvIdx, ++ArgIdx) { 6017 if (ArgIdx < NumArgsInProto) 6018 Cand->Conversions[ConvIdx] 6019 = TryCopyInitialization(S, Args[ArgIdx], Proto->getArgType(ArgIdx), 6020 SuppressUserConversions, 6021 /*InOverloadResolution=*/true); 6022 else 6023 Cand->Conversions[ConvIdx].setEllipsis(); 6024 } 6025} 6026 6027} // end anonymous namespace 6028 6029/// PrintOverloadCandidates - When overload resolution fails, prints 6030/// diagnostic messages containing the candidates in the candidate 6031/// set. 6032void 6033Sema::PrintOverloadCandidates(OverloadCandidateSet& CandidateSet, 6034 OverloadCandidateDisplayKind OCD, 6035 Expr **Args, unsigned NumArgs, 6036 const char *Opc, 6037 SourceLocation OpLoc) { 6038 // Sort the candidates by viability and position. Sorting directly would 6039 // be prohibitive, so we make a set of pointers and sort those. 6040 llvm::SmallVector<OverloadCandidate*, 32> Cands; 6041 if (OCD == OCD_AllCandidates) Cands.reserve(CandidateSet.size()); 6042 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 6043 LastCand = CandidateSet.end(); 6044 Cand != LastCand; ++Cand) { 6045 if (Cand->Viable) 6046 Cands.push_back(Cand); 6047 else if (OCD == OCD_AllCandidates) { 6048 CompleteNonViableCandidate(*this, Cand, Args, NumArgs); 6049 if (Cand->Function || Cand->IsSurrogate) 6050 Cands.push_back(Cand); 6051 // Otherwise, this a non-viable builtin candidate. We do not, in general, 6052 // want to list every possible builtin candidate. 6053 } 6054 } 6055 6056 std::sort(Cands.begin(), Cands.end(), 6057 CompareOverloadCandidatesForDisplay(*this)); 6058 6059 bool ReportedAmbiguousConversions = false; 6060 6061 llvm::SmallVectorImpl<OverloadCandidate*>::iterator I, E; 6062 const Diagnostic::OverloadsShown ShowOverloads = Diags.getShowOverloads(); 6063 unsigned CandsShown = 0; 6064 for (I = Cands.begin(), E = Cands.end(); I != E; ++I) { 6065 OverloadCandidate *Cand = *I; 6066 6067 // Set an arbitrary limit on the number of candidate functions we'll spam 6068 // the user with. FIXME: This limit should depend on details of the 6069 // candidate list. 6070 if (CandsShown >= 4 && ShowOverloads == Diagnostic::Ovl_Best) { 6071 break; 6072 } 6073 ++CandsShown; 6074 6075 if (Cand->Function) 6076 NoteFunctionCandidate(*this, Cand, Args, NumArgs); 6077 else if (Cand->IsSurrogate) 6078 NoteSurrogateCandidate(*this, Cand); 6079 else { 6080 assert(Cand->Viable && 6081 "Non-viable built-in candidates are not added to Cands."); 6082 // Generally we only see ambiguities including viable builtin 6083 // operators if overload resolution got screwed up by an 6084 // ambiguous user-defined conversion. 6085 // 6086 // FIXME: It's quite possible for different conversions to see 6087 // different ambiguities, though. 6088 if (!ReportedAmbiguousConversions) { 6089 NoteAmbiguousUserConversions(*this, OpLoc, Cand); 6090 ReportedAmbiguousConversions = true; 6091 } 6092 6093 // If this is a viable builtin, print it. 6094 NoteBuiltinOperatorCandidate(*this, Opc, OpLoc, Cand); 6095 } 6096 } 6097 6098 if (I != E) 6099 Diag(OpLoc, diag::note_ovl_too_many_candidates) << int(E - I); 6100} 6101 6102static bool CheckUnresolvedAccess(Sema &S, OverloadExpr *E, DeclAccessPair D) { 6103 if (isa<UnresolvedLookupExpr>(E)) 6104 return S.CheckUnresolvedLookupAccess(cast<UnresolvedLookupExpr>(E), D); 6105 6106 return S.CheckUnresolvedMemberAccess(cast<UnresolvedMemberExpr>(E), D); 6107} 6108 6109/// ResolveAddressOfOverloadedFunction - Try to resolve the address of 6110/// an overloaded function (C++ [over.over]), where @p From is an 6111/// expression with overloaded function type and @p ToType is the type 6112/// we're trying to resolve to. For example: 6113/// 6114/// @code 6115/// int f(double); 6116/// int f(int); 6117/// 6118/// int (*pfd)(double) = f; // selects f(double) 6119/// @endcode 6120/// 6121/// This routine returns the resulting FunctionDecl if it could be 6122/// resolved, and NULL otherwise. When @p Complain is true, this 6123/// routine will emit diagnostics if there is an error. 6124FunctionDecl * 6125Sema::ResolveAddressOfOverloadedFunction(Expr *From, QualType ToType, 6126 bool Complain, 6127 DeclAccessPair &FoundResult) { 6128 QualType FunctionType = ToType; 6129 bool IsMember = false; 6130 if (const PointerType *ToTypePtr = ToType->getAs<PointerType>()) 6131 FunctionType = ToTypePtr->getPointeeType(); 6132 else if (const ReferenceType *ToTypeRef = ToType->getAs<ReferenceType>()) 6133 FunctionType = ToTypeRef->getPointeeType(); 6134 else if (const MemberPointerType *MemTypePtr = 6135 ToType->getAs<MemberPointerType>()) { 6136 FunctionType = MemTypePtr->getPointeeType(); 6137 IsMember = true; 6138 } 6139 6140 // C++ [over.over]p1: 6141 // [...] [Note: any redundant set of parentheses surrounding the 6142 // overloaded function name is ignored (5.1). ] 6143 // C++ [over.over]p1: 6144 // [...] The overloaded function name can be preceded by the & 6145 // operator. 6146 OverloadExpr *OvlExpr = OverloadExpr::find(From).getPointer(); 6147 TemplateArgumentListInfo ETABuffer, *ExplicitTemplateArgs = 0; 6148 if (OvlExpr->hasExplicitTemplateArgs()) { 6149 OvlExpr->getExplicitTemplateArgs().copyInto(ETABuffer); 6150 ExplicitTemplateArgs = &ETABuffer; 6151 } 6152 6153 // We expect a pointer or reference to function, or a function pointer. 6154 FunctionType = Context.getCanonicalType(FunctionType).getUnqualifiedType(); 6155 if (!FunctionType->isFunctionType()) { 6156 if (Complain) 6157 Diag(From->getLocStart(), diag::err_addr_ovl_not_func_ptrref) 6158 << OvlExpr->getName() << ToType; 6159 6160 return 0; 6161 } 6162 6163 assert(From->getType() == Context.OverloadTy); 6164 6165 // Look through all of the overloaded functions, searching for one 6166 // whose type matches exactly. 6167 llvm::SmallVector<std::pair<DeclAccessPair, FunctionDecl*>, 4> Matches; 6168 llvm::SmallVector<FunctionDecl *, 4> NonMatches; 6169 6170 bool FoundNonTemplateFunction = false; 6171 for (UnresolvedSetIterator I = OvlExpr->decls_begin(), 6172 E = OvlExpr->decls_end(); I != E; ++I) { 6173 // Look through any using declarations to find the underlying function. 6174 NamedDecl *Fn = (*I)->getUnderlyingDecl(); 6175 6176 // C++ [over.over]p3: 6177 // Non-member functions and static member functions match 6178 // targets of type "pointer-to-function" or "reference-to-function." 6179 // Nonstatic member functions match targets of 6180 // type "pointer-to-member-function." 6181 // Note that according to DR 247, the containing class does not matter. 6182 6183 if (FunctionTemplateDecl *FunctionTemplate 6184 = dyn_cast<FunctionTemplateDecl>(Fn)) { 6185 if (CXXMethodDecl *Method 6186 = dyn_cast<CXXMethodDecl>(FunctionTemplate->getTemplatedDecl())) { 6187 // Skip non-static function templates when converting to pointer, and 6188 // static when converting to member pointer. 6189 if (Method->isStatic() == IsMember) 6190 continue; 6191 } else if (IsMember) 6192 continue; 6193 6194 // C++ [over.over]p2: 6195 // If the name is a function template, template argument deduction is 6196 // done (14.8.2.2), and if the argument deduction succeeds, the 6197 // resulting template argument list is used to generate a single 6198 // function template specialization, which is added to the set of 6199 // overloaded functions considered. 6200 // FIXME: We don't really want to build the specialization here, do we? 6201 FunctionDecl *Specialization = 0; 6202 TemplateDeductionInfo Info(Context, OvlExpr->getNameLoc()); 6203 if (TemplateDeductionResult Result 6204 = DeduceTemplateArguments(FunctionTemplate, ExplicitTemplateArgs, 6205 FunctionType, Specialization, Info)) { 6206 // FIXME: make a note of the failed deduction for diagnostics. 6207 (void)Result; 6208 } else { 6209 // FIXME: If the match isn't exact, shouldn't we just drop this as 6210 // a candidate? Find a testcase before changing the code. 6211 assert(FunctionType 6212 == Context.getCanonicalType(Specialization->getType())); 6213 Matches.push_back(std::make_pair(I.getPair(), 6214 cast<FunctionDecl>(Specialization->getCanonicalDecl()))); 6215 } 6216 6217 continue; 6218 } 6219 6220 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 6221 // Skip non-static functions when converting to pointer, and static 6222 // when converting to member pointer. 6223 if (Method->isStatic() == IsMember) 6224 continue; 6225 6226 // If we have explicit template arguments, skip non-templates. 6227 if (OvlExpr->hasExplicitTemplateArgs()) 6228 continue; 6229 } else if (IsMember) 6230 continue; 6231 6232 if (FunctionDecl *FunDecl = dyn_cast<FunctionDecl>(Fn)) { 6233 QualType ResultTy; 6234 if (Context.hasSameUnqualifiedType(FunctionType, FunDecl->getType()) || 6235 IsNoReturnConversion(Context, FunDecl->getType(), FunctionType, 6236 ResultTy)) { 6237 Matches.push_back(std::make_pair(I.getPair(), 6238 cast<FunctionDecl>(FunDecl->getCanonicalDecl()))); 6239 FoundNonTemplateFunction = true; 6240 } 6241 } 6242 } 6243 6244 // If there were 0 or 1 matches, we're done. 6245 if (Matches.empty()) { 6246 if (Complain) { 6247 Diag(From->getLocStart(), diag::err_addr_ovl_no_viable) 6248 << OvlExpr->getName() << FunctionType; 6249 for (UnresolvedSetIterator I = OvlExpr->decls_begin(), 6250 E = OvlExpr->decls_end(); 6251 I != E; ++I) 6252 if (FunctionDecl *F = dyn_cast<FunctionDecl>((*I)->getUnderlyingDecl())) 6253 NoteOverloadCandidate(F); 6254 } 6255 6256 return 0; 6257 } else if (Matches.size() == 1) { 6258 FunctionDecl *Result = Matches[0].second; 6259 FoundResult = Matches[0].first; 6260 MarkDeclarationReferenced(From->getLocStart(), Result); 6261 if (Complain) 6262 CheckAddressOfMemberAccess(OvlExpr, Matches[0].first); 6263 return Result; 6264 } 6265 6266 // C++ [over.over]p4: 6267 // If more than one function is selected, [...] 6268 if (!FoundNonTemplateFunction) { 6269 // [...] and any given function template specialization F1 is 6270 // eliminated if the set contains a second function template 6271 // specialization whose function template is more specialized 6272 // than the function template of F1 according to the partial 6273 // ordering rules of 14.5.5.2. 6274 6275 // The algorithm specified above is quadratic. We instead use a 6276 // two-pass algorithm (similar to the one used to identify the 6277 // best viable function in an overload set) that identifies the 6278 // best function template (if it exists). 6279 6280 UnresolvedSet<4> MatchesCopy; // TODO: avoid! 6281 for (unsigned I = 0, E = Matches.size(); I != E; ++I) 6282 MatchesCopy.addDecl(Matches[I].second, Matches[I].first.getAccess()); 6283 6284 UnresolvedSetIterator Result = 6285 getMostSpecialized(MatchesCopy.begin(), MatchesCopy.end(), 6286 TPOC_Other, From->getLocStart(), 6287 PDiag(), 6288 PDiag(diag::err_addr_ovl_ambiguous) 6289 << Matches[0].second->getDeclName(), 6290 PDiag(diag::note_ovl_candidate) 6291 << (unsigned) oc_function_template); 6292 assert(Result != MatchesCopy.end() && "no most-specialized template"); 6293 MarkDeclarationReferenced(From->getLocStart(), *Result); 6294 FoundResult = Matches[Result - MatchesCopy.begin()].first; 6295 if (Complain) { 6296 CheckUnresolvedAccess(*this, OvlExpr, FoundResult); 6297 DiagnoseUseOfDecl(FoundResult, OvlExpr->getNameLoc()); 6298 } 6299 return cast<FunctionDecl>(*Result); 6300 } 6301 6302 // [...] any function template specializations in the set are 6303 // eliminated if the set also contains a non-template function, [...] 6304 for (unsigned I = 0, N = Matches.size(); I != N; ) { 6305 if (Matches[I].second->getPrimaryTemplate() == 0) 6306 ++I; 6307 else { 6308 Matches[I] = Matches[--N]; 6309 Matches.set_size(N); 6310 } 6311 } 6312 6313 // [...] After such eliminations, if any, there shall remain exactly one 6314 // selected function. 6315 if (Matches.size() == 1) { 6316 MarkDeclarationReferenced(From->getLocStart(), Matches[0].second); 6317 FoundResult = Matches[0].first; 6318 if (Complain) { 6319 CheckUnresolvedAccess(*this, OvlExpr, Matches[0].first); 6320 DiagnoseUseOfDecl(Matches[0].first, OvlExpr->getNameLoc()); 6321 } 6322 return cast<FunctionDecl>(Matches[0].second); 6323 } 6324 6325 // FIXME: We should probably return the same thing that BestViableFunction 6326 // returns (even if we issue the diagnostics here). 6327 Diag(From->getLocStart(), diag::err_addr_ovl_ambiguous) 6328 << Matches[0].second->getDeclName(); 6329 for (unsigned I = 0, E = Matches.size(); I != E; ++I) 6330 NoteOverloadCandidate(Matches[I].second); 6331 return 0; 6332} 6333 6334/// \brief Given an expression that refers to an overloaded function, try to 6335/// resolve that overloaded function expression down to a single function. 6336/// 6337/// This routine can only resolve template-ids that refer to a single function 6338/// template, where that template-id refers to a single template whose template 6339/// arguments are either provided by the template-id or have defaults, 6340/// as described in C++0x [temp.arg.explicit]p3. 6341FunctionDecl *Sema::ResolveSingleFunctionTemplateSpecialization(Expr *From) { 6342 // C++ [over.over]p1: 6343 // [...] [Note: any redundant set of parentheses surrounding the 6344 // overloaded function name is ignored (5.1). ] 6345 // C++ [over.over]p1: 6346 // [...] The overloaded function name can be preceded by the & 6347 // operator. 6348 6349 if (From->getType() != Context.OverloadTy) 6350 return 0; 6351 6352 OverloadExpr *OvlExpr = OverloadExpr::find(From).getPointer(); 6353 6354 // If we didn't actually find any template-ids, we're done. 6355 if (!OvlExpr->hasExplicitTemplateArgs()) 6356 return 0; 6357 6358 TemplateArgumentListInfo ExplicitTemplateArgs; 6359 OvlExpr->getExplicitTemplateArgs().copyInto(ExplicitTemplateArgs); 6360 6361 // Look through all of the overloaded functions, searching for one 6362 // whose type matches exactly. 6363 FunctionDecl *Matched = 0; 6364 for (UnresolvedSetIterator I = OvlExpr->decls_begin(), 6365 E = OvlExpr->decls_end(); I != E; ++I) { 6366 // C++0x [temp.arg.explicit]p3: 6367 // [...] In contexts where deduction is done and fails, or in contexts 6368 // where deduction is not done, if a template argument list is 6369 // specified and it, along with any default template arguments, 6370 // identifies a single function template specialization, then the 6371 // template-id is an lvalue for the function template specialization. 6372 FunctionTemplateDecl *FunctionTemplate 6373 = cast<FunctionTemplateDecl>((*I)->getUnderlyingDecl()); 6374 6375 // C++ [over.over]p2: 6376 // If the name is a function template, template argument deduction is 6377 // done (14.8.2.2), and if the argument deduction succeeds, the 6378 // resulting template argument list is used to generate a single 6379 // function template specialization, which is added to the set of 6380 // overloaded functions considered. 6381 FunctionDecl *Specialization = 0; 6382 TemplateDeductionInfo Info(Context, OvlExpr->getNameLoc()); 6383 if (TemplateDeductionResult Result 6384 = DeduceTemplateArguments(FunctionTemplate, &ExplicitTemplateArgs, 6385 Specialization, Info)) { 6386 // FIXME: make a note of the failed deduction for diagnostics. 6387 (void)Result; 6388 continue; 6389 } 6390 6391 // Multiple matches; we can't resolve to a single declaration. 6392 if (Matched) 6393 return 0; 6394 6395 Matched = Specialization; 6396 } 6397 6398 return Matched; 6399} 6400 6401/// \brief Add a single candidate to the overload set. 6402static void AddOverloadedCallCandidate(Sema &S, 6403 DeclAccessPair FoundDecl, 6404 const TemplateArgumentListInfo *ExplicitTemplateArgs, 6405 Expr **Args, unsigned NumArgs, 6406 OverloadCandidateSet &CandidateSet, 6407 bool PartialOverloading) { 6408 NamedDecl *Callee = FoundDecl.getDecl(); 6409 if (isa<UsingShadowDecl>(Callee)) 6410 Callee = cast<UsingShadowDecl>(Callee)->getTargetDecl(); 6411 6412 if (FunctionDecl *Func = dyn_cast<FunctionDecl>(Callee)) { 6413 assert(!ExplicitTemplateArgs && "Explicit template arguments?"); 6414 S.AddOverloadCandidate(Func, FoundDecl, Args, NumArgs, CandidateSet, 6415 false, PartialOverloading); 6416 return; 6417 } 6418 6419 if (FunctionTemplateDecl *FuncTemplate 6420 = dyn_cast<FunctionTemplateDecl>(Callee)) { 6421 S.AddTemplateOverloadCandidate(FuncTemplate, FoundDecl, 6422 ExplicitTemplateArgs, 6423 Args, NumArgs, CandidateSet); 6424 return; 6425 } 6426 6427 assert(false && "unhandled case in overloaded call candidate"); 6428 6429 // do nothing? 6430} 6431 6432/// \brief Add the overload candidates named by callee and/or found by argument 6433/// dependent lookup to the given overload set. 6434void Sema::AddOverloadedCallCandidates(UnresolvedLookupExpr *ULE, 6435 Expr **Args, unsigned NumArgs, 6436 OverloadCandidateSet &CandidateSet, 6437 bool PartialOverloading) { 6438 6439#ifndef NDEBUG 6440 // Verify that ArgumentDependentLookup is consistent with the rules 6441 // in C++0x [basic.lookup.argdep]p3: 6442 // 6443 // Let X be the lookup set produced by unqualified lookup (3.4.1) 6444 // and let Y be the lookup set produced by argument dependent 6445 // lookup (defined as follows). If X contains 6446 // 6447 // -- a declaration of a class member, or 6448 // 6449 // -- a block-scope function declaration that is not a 6450 // using-declaration, or 6451 // 6452 // -- a declaration that is neither a function or a function 6453 // template 6454 // 6455 // then Y is empty. 6456 6457 if (ULE->requiresADL()) { 6458 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(), 6459 E = ULE->decls_end(); I != E; ++I) { 6460 assert(!(*I)->getDeclContext()->isRecord()); 6461 assert(isa<UsingShadowDecl>(*I) || 6462 !(*I)->getDeclContext()->isFunctionOrMethod()); 6463 assert((*I)->getUnderlyingDecl()->isFunctionOrFunctionTemplate()); 6464 } 6465 } 6466#endif 6467 6468 // It would be nice to avoid this copy. 6469 TemplateArgumentListInfo TABuffer; 6470 const TemplateArgumentListInfo *ExplicitTemplateArgs = 0; 6471 if (ULE->hasExplicitTemplateArgs()) { 6472 ULE->copyTemplateArgumentsInto(TABuffer); 6473 ExplicitTemplateArgs = &TABuffer; 6474 } 6475 6476 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(), 6477 E = ULE->decls_end(); I != E; ++I) 6478 AddOverloadedCallCandidate(*this, I.getPair(), ExplicitTemplateArgs, 6479 Args, NumArgs, CandidateSet, 6480 PartialOverloading); 6481 6482 if (ULE->requiresADL()) 6483 AddArgumentDependentLookupCandidates(ULE->getName(), /*Operator*/ false, 6484 Args, NumArgs, 6485 ExplicitTemplateArgs, 6486 CandidateSet, 6487 PartialOverloading); 6488} 6489 6490/// Attempts to recover from a call where no functions were found. 6491/// 6492/// Returns true if new candidates were found. 6493static Sema::OwningExprResult 6494BuildRecoveryCallExpr(Sema &SemaRef, Scope *S, Expr *Fn, 6495 UnresolvedLookupExpr *ULE, 6496 SourceLocation LParenLoc, 6497 Expr **Args, unsigned NumArgs, 6498 SourceLocation *CommaLocs, 6499 SourceLocation RParenLoc) { 6500 6501 CXXScopeSpec SS; 6502 if (ULE->getQualifier()) { 6503 SS.setScopeRep(ULE->getQualifier()); 6504 SS.setRange(ULE->getQualifierRange()); 6505 } 6506 6507 TemplateArgumentListInfo TABuffer; 6508 const TemplateArgumentListInfo *ExplicitTemplateArgs = 0; 6509 if (ULE->hasExplicitTemplateArgs()) { 6510 ULE->copyTemplateArgumentsInto(TABuffer); 6511 ExplicitTemplateArgs = &TABuffer; 6512 } 6513 6514 LookupResult R(SemaRef, ULE->getName(), ULE->getNameLoc(), 6515 Sema::LookupOrdinaryName); 6516 if (SemaRef.DiagnoseEmptyLookup(S, SS, R, Sema::CTC_Expression)) 6517 return SemaRef.ExprError(); 6518 6519 assert(!R.empty() && "lookup results empty despite recovery"); 6520 6521 // Build an implicit member call if appropriate. Just drop the 6522 // casts and such from the call, we don't really care. 6523 Sema::OwningExprResult NewFn = SemaRef.ExprError(); 6524 if ((*R.begin())->isCXXClassMember()) 6525 NewFn = SemaRef.BuildPossibleImplicitMemberExpr(SS, R, ExplicitTemplateArgs); 6526 else if (ExplicitTemplateArgs) 6527 NewFn = SemaRef.BuildTemplateIdExpr(SS, R, false, *ExplicitTemplateArgs); 6528 else 6529 NewFn = SemaRef.BuildDeclarationNameExpr(SS, R, false); 6530 6531 if (NewFn.isInvalid()) 6532 return SemaRef.ExprError(); 6533 6534 // This shouldn't cause an infinite loop because we're giving it 6535 // an expression with non-empty lookup results, which should never 6536 // end up here. 6537 return SemaRef.ActOnCallExpr(/*Scope*/ 0, move(NewFn), LParenLoc, 6538 Sema::MultiExprArg(SemaRef, (void**) Args, NumArgs), 6539 CommaLocs, RParenLoc); 6540} 6541 6542/// ResolveOverloadedCallFn - Given the call expression that calls Fn 6543/// (which eventually refers to the declaration Func) and the call 6544/// arguments Args/NumArgs, attempt to resolve the function call down 6545/// to a specific function. If overload resolution succeeds, returns 6546/// the function declaration produced by overload 6547/// resolution. Otherwise, emits diagnostics, deletes all of the 6548/// arguments and Fn, and returns NULL. 6549Sema::OwningExprResult 6550Sema::BuildOverloadedCallExpr(Scope *S, Expr *Fn, UnresolvedLookupExpr *ULE, 6551 SourceLocation LParenLoc, 6552 Expr **Args, unsigned NumArgs, 6553 SourceLocation *CommaLocs, 6554 SourceLocation RParenLoc) { 6555#ifndef NDEBUG 6556 if (ULE->requiresADL()) { 6557 // To do ADL, we must have found an unqualified name. 6558 assert(!ULE->getQualifier() && "qualified name with ADL"); 6559 6560 // We don't perform ADL for implicit declarations of builtins. 6561 // Verify that this was correctly set up. 6562 FunctionDecl *F; 6563 if (ULE->decls_begin() + 1 == ULE->decls_end() && 6564 (F = dyn_cast<FunctionDecl>(*ULE->decls_begin())) && 6565 F->getBuiltinID() && F->isImplicit()) 6566 assert(0 && "performing ADL for builtin"); 6567 6568 // We don't perform ADL in C. 6569 assert(getLangOptions().CPlusPlus && "ADL enabled in C"); 6570 } 6571#endif 6572 6573 OverloadCandidateSet CandidateSet(Fn->getExprLoc()); 6574 6575 // Add the functions denoted by the callee to the set of candidate 6576 // functions, including those from argument-dependent lookup. 6577 AddOverloadedCallCandidates(ULE, Args, NumArgs, CandidateSet); 6578 6579 // If we found nothing, try to recover. 6580 // AddRecoveryCallCandidates diagnoses the error itself, so we just 6581 // bailout out if it fails. 6582 if (CandidateSet.empty()) 6583 return BuildRecoveryCallExpr(*this, S, Fn, ULE, LParenLoc, Args, NumArgs, 6584 CommaLocs, RParenLoc); 6585 6586 OverloadCandidateSet::iterator Best; 6587 switch (BestViableFunction(CandidateSet, Fn->getLocStart(), Best)) { 6588 case OR_Success: { 6589 FunctionDecl *FDecl = Best->Function; 6590 CheckUnresolvedLookupAccess(ULE, Best->FoundDecl); 6591 DiagnoseUseOfDecl(Best->FoundDecl, ULE->getNameLoc()); 6592 Fn = FixOverloadedFunctionReference(Fn, Best->FoundDecl, FDecl); 6593 return BuildResolvedCallExpr(Fn, FDecl, LParenLoc, Args, NumArgs, RParenLoc); 6594 } 6595 6596 case OR_No_Viable_Function: 6597 Diag(Fn->getSourceRange().getBegin(), 6598 diag::err_ovl_no_viable_function_in_call) 6599 << ULE->getName() << Fn->getSourceRange(); 6600 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6601 break; 6602 6603 case OR_Ambiguous: 6604 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_ambiguous_call) 6605 << ULE->getName() << Fn->getSourceRange(); 6606 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, NumArgs); 6607 break; 6608 6609 case OR_Deleted: 6610 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_deleted_call) 6611 << Best->Function->isDeleted() 6612 << ULE->getName() 6613 << Fn->getSourceRange(); 6614 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6615 break; 6616 } 6617 6618 // Overload resolution failed. 6619 return ExprError(); 6620} 6621 6622static bool IsOverloaded(const UnresolvedSetImpl &Functions) { 6623 return Functions.size() > 1 || 6624 (Functions.size() == 1 && isa<FunctionTemplateDecl>(*Functions.begin())); 6625} 6626 6627/// \brief Create a unary operation that may resolve to an overloaded 6628/// operator. 6629/// 6630/// \param OpLoc The location of the operator itself (e.g., '*'). 6631/// 6632/// \param OpcIn The UnaryOperator::Opcode that describes this 6633/// operator. 6634/// 6635/// \param Functions The set of non-member functions that will be 6636/// considered by overload resolution. The caller needs to build this 6637/// set based on the context using, e.g., 6638/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 6639/// set should not contain any member functions; those will be added 6640/// by CreateOverloadedUnaryOp(). 6641/// 6642/// \param input The input argument. 6643Sema::OwningExprResult 6644Sema::CreateOverloadedUnaryOp(SourceLocation OpLoc, unsigned OpcIn, 6645 const UnresolvedSetImpl &Fns, 6646 ExprArg input) { 6647 UnaryOperator::Opcode Opc = static_cast<UnaryOperator::Opcode>(OpcIn); 6648 Expr *Input = (Expr *)input.get(); 6649 6650 OverloadedOperatorKind Op = UnaryOperator::getOverloadedOperator(Opc); 6651 assert(Op != OO_None && "Invalid opcode for overloaded unary operator"); 6652 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 6653 // TODO: provide better source location info. 6654 DeclarationNameInfo OpNameInfo(OpName, OpLoc); 6655 6656 Expr *Args[2] = { Input, 0 }; 6657 unsigned NumArgs = 1; 6658 6659 // For post-increment and post-decrement, add the implicit '0' as 6660 // the second argument, so that we know this is a post-increment or 6661 // post-decrement. 6662 if (Opc == UnaryOperator::PostInc || Opc == UnaryOperator::PostDec) { 6663 llvm::APSInt Zero(Context.getTypeSize(Context.IntTy), false); 6664 Args[1] = new (Context) IntegerLiteral(Zero, Context.IntTy, 6665 SourceLocation()); 6666 NumArgs = 2; 6667 } 6668 6669 if (Input->isTypeDependent()) { 6670 if (Fns.empty()) 6671 return Owned(new (Context) UnaryOperator(input.takeAs<Expr>(), 6672 Opc, 6673 Context.DependentTy, 6674 OpLoc)); 6675 6676 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 6677 UnresolvedLookupExpr *Fn 6678 = UnresolvedLookupExpr::Create(Context, /*Dependent*/ true, NamingClass, 6679 0, SourceRange(), OpNameInfo, 6680 /*ADL*/ true, IsOverloaded(Fns), 6681 Fns.begin(), Fns.end()); 6682 input.release(); 6683 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 6684 &Args[0], NumArgs, 6685 Context.DependentTy, 6686 OpLoc)); 6687 } 6688 6689 // Build an empty overload set. 6690 OverloadCandidateSet CandidateSet(OpLoc); 6691 6692 // Add the candidates from the given function set. 6693 AddFunctionCandidates(Fns, &Args[0], NumArgs, CandidateSet, false); 6694 6695 // Add operator candidates that are member functions. 6696 AddMemberOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 6697 6698 // Add candidates from ADL. 6699 AddArgumentDependentLookupCandidates(OpName, /*Operator*/ true, 6700 Args, NumArgs, 6701 /*ExplicitTemplateArgs*/ 0, 6702 CandidateSet); 6703 6704 // Add builtin operator candidates. 6705 AddBuiltinOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 6706 6707 // Perform overload resolution. 6708 OverloadCandidateSet::iterator Best; 6709 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 6710 case OR_Success: { 6711 // We found a built-in operator or an overloaded operator. 6712 FunctionDecl *FnDecl = Best->Function; 6713 6714 if (FnDecl) { 6715 // We matched an overloaded operator. Build a call to that 6716 // operator. 6717 6718 // Convert the arguments. 6719 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 6720 CheckMemberOperatorAccess(OpLoc, Args[0], 0, Best->FoundDecl); 6721 6722 if (PerformObjectArgumentInitialization(Input, /*Qualifier=*/0, 6723 Best->FoundDecl, Method)) 6724 return ExprError(); 6725 } else { 6726 // Convert the arguments. 6727 OwningExprResult InputInit 6728 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 6729 FnDecl->getParamDecl(0)), 6730 SourceLocation(), 6731 move(input)); 6732 if (InputInit.isInvalid()) 6733 return ExprError(); 6734 6735 input = move(InputInit); 6736 Input = (Expr *)input.get(); 6737 } 6738 6739 DiagnoseUseOfDecl(Best->FoundDecl, OpLoc); 6740 6741 // Determine the result type 6742 QualType ResultTy = FnDecl->getCallResultType(); 6743 6744 // Build the actual expression node. 6745 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 6746 SourceLocation()); 6747 UsualUnaryConversions(FnExpr); 6748 6749 input.release(); 6750 Args[0] = Input; 6751 ExprOwningPtr<CallExpr> TheCall(this, 6752 new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 6753 Args, NumArgs, ResultTy, OpLoc)); 6754 6755 if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall.get(), 6756 FnDecl)) 6757 return ExprError(); 6758 6759 return MaybeBindToTemporary(TheCall.release()); 6760 } else { 6761 // We matched a built-in operator. Convert the arguments, then 6762 // break out so that we will build the appropriate built-in 6763 // operator node. 6764 if (PerformImplicitConversion(Input, Best->BuiltinTypes.ParamTypes[0], 6765 Best->Conversions[0], AA_Passing)) 6766 return ExprError(); 6767 6768 break; 6769 } 6770 } 6771 6772 case OR_No_Viable_Function: 6773 // No viable function; fall through to handling this as a 6774 // built-in operator, which will produce an error message for us. 6775 break; 6776 6777 case OR_Ambiguous: 6778 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 6779 << UnaryOperator::getOpcodeStr(Opc) 6780 << Input->getSourceRange(); 6781 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, NumArgs, 6782 UnaryOperator::getOpcodeStr(Opc), OpLoc); 6783 return ExprError(); 6784 6785 case OR_Deleted: 6786 Diag(OpLoc, diag::err_ovl_deleted_oper) 6787 << Best->Function->isDeleted() 6788 << UnaryOperator::getOpcodeStr(Opc) 6789 << Input->getSourceRange(); 6790 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6791 return ExprError(); 6792 } 6793 6794 // Either we found no viable overloaded operator or we matched a 6795 // built-in operator. In either case, fall through to trying to 6796 // build a built-in operation. 6797 input.release(); 6798 return CreateBuiltinUnaryOp(OpLoc, Opc, Owned(Input)); 6799} 6800 6801/// \brief Create a binary operation that may resolve to an overloaded 6802/// operator. 6803/// 6804/// \param OpLoc The location of the operator itself (e.g., '+'). 6805/// 6806/// \param OpcIn The BinaryOperator::Opcode that describes this 6807/// operator. 6808/// 6809/// \param Functions The set of non-member functions that will be 6810/// considered by overload resolution. The caller needs to build this 6811/// set based on the context using, e.g., 6812/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 6813/// set should not contain any member functions; those will be added 6814/// by CreateOverloadedBinOp(). 6815/// 6816/// \param LHS Left-hand argument. 6817/// \param RHS Right-hand argument. 6818Sema::OwningExprResult 6819Sema::CreateOverloadedBinOp(SourceLocation OpLoc, 6820 unsigned OpcIn, 6821 const UnresolvedSetImpl &Fns, 6822 Expr *LHS, Expr *RHS) { 6823 Expr *Args[2] = { LHS, RHS }; 6824 LHS=RHS=0; //Please use only Args instead of LHS/RHS couple 6825 6826 BinaryOperator::Opcode Opc = static_cast<BinaryOperator::Opcode>(OpcIn); 6827 OverloadedOperatorKind Op = BinaryOperator::getOverloadedOperator(Opc); 6828 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 6829 6830 // If either side is type-dependent, create an appropriate dependent 6831 // expression. 6832 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 6833 if (Fns.empty()) { 6834 // If there are no functions to store, just build a dependent 6835 // BinaryOperator or CompoundAssignment. 6836 if (Opc <= BinaryOperator::Assign || Opc > BinaryOperator::OrAssign) 6837 return Owned(new (Context) BinaryOperator(Args[0], Args[1], Opc, 6838 Context.DependentTy, OpLoc)); 6839 6840 return Owned(new (Context) CompoundAssignOperator(Args[0], Args[1], Opc, 6841 Context.DependentTy, 6842 Context.DependentTy, 6843 Context.DependentTy, 6844 OpLoc)); 6845 } 6846 6847 // FIXME: save results of ADL from here? 6848 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 6849 // TODO: provide better source location info in DNLoc component. 6850 DeclarationNameInfo OpNameInfo(OpName, OpLoc); 6851 UnresolvedLookupExpr *Fn 6852 = UnresolvedLookupExpr::Create(Context, /*Dependent*/ true, NamingClass, 6853 0, SourceRange(), OpNameInfo, 6854 /*ADL*/ true, IsOverloaded(Fns), 6855 Fns.begin(), Fns.end()); 6856 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 6857 Args, 2, 6858 Context.DependentTy, 6859 OpLoc)); 6860 } 6861 6862 // If this is the .* operator, which is not overloadable, just 6863 // create a built-in binary operator. 6864 if (Opc == BinaryOperator::PtrMemD) 6865 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 6866 6867 // If this is the assignment operator, we only perform overload resolution 6868 // if the left-hand side is a class or enumeration type. This is actually 6869 // a hack. The standard requires that we do overload resolution between the 6870 // various built-in candidates, but as DR507 points out, this can lead to 6871 // problems. So we do it this way, which pretty much follows what GCC does. 6872 // Note that we go the traditional code path for compound assignment forms. 6873 if (Opc==BinaryOperator::Assign && !Args[0]->getType()->isOverloadableType()) 6874 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 6875 6876 // Build an empty overload set. 6877 OverloadCandidateSet CandidateSet(OpLoc); 6878 6879 // Add the candidates from the given function set. 6880 AddFunctionCandidates(Fns, Args, 2, CandidateSet, false); 6881 6882 // Add operator candidates that are member functions. 6883 AddMemberOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 6884 6885 // Add candidates from ADL. 6886 AddArgumentDependentLookupCandidates(OpName, /*Operator*/ true, 6887 Args, 2, 6888 /*ExplicitTemplateArgs*/ 0, 6889 CandidateSet); 6890 6891 // Add builtin operator candidates. 6892 AddBuiltinOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 6893 6894 // Perform overload resolution. 6895 OverloadCandidateSet::iterator Best; 6896 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 6897 case OR_Success: { 6898 // We found a built-in operator or an overloaded operator. 6899 FunctionDecl *FnDecl = Best->Function; 6900 6901 if (FnDecl) { 6902 // We matched an overloaded operator. Build a call to that 6903 // operator. 6904 6905 // Convert the arguments. 6906 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 6907 // Best->Access is only meaningful for class members. 6908 CheckMemberOperatorAccess(OpLoc, Args[0], Args[1], Best->FoundDecl); 6909 6910 OwningExprResult Arg1 6911 = PerformCopyInitialization( 6912 InitializedEntity::InitializeParameter( 6913 FnDecl->getParamDecl(0)), 6914 SourceLocation(), 6915 Owned(Args[1])); 6916 if (Arg1.isInvalid()) 6917 return ExprError(); 6918 6919 if (PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/0, 6920 Best->FoundDecl, Method)) 6921 return ExprError(); 6922 6923 Args[1] = RHS = Arg1.takeAs<Expr>(); 6924 } else { 6925 // Convert the arguments. 6926 OwningExprResult Arg0 6927 = PerformCopyInitialization( 6928 InitializedEntity::InitializeParameter( 6929 FnDecl->getParamDecl(0)), 6930 SourceLocation(), 6931 Owned(Args[0])); 6932 if (Arg0.isInvalid()) 6933 return ExprError(); 6934 6935 OwningExprResult Arg1 6936 = PerformCopyInitialization( 6937 InitializedEntity::InitializeParameter( 6938 FnDecl->getParamDecl(1)), 6939 SourceLocation(), 6940 Owned(Args[1])); 6941 if (Arg1.isInvalid()) 6942 return ExprError(); 6943 Args[0] = LHS = Arg0.takeAs<Expr>(); 6944 Args[1] = RHS = Arg1.takeAs<Expr>(); 6945 } 6946 6947 DiagnoseUseOfDecl(Best->FoundDecl, OpLoc); 6948 6949 // Determine the result type 6950 QualType ResultTy 6951 = FnDecl->getType()->getAs<FunctionType>() 6952 ->getCallResultType(Context); 6953 6954 // Build the actual expression node. 6955 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 6956 OpLoc); 6957 UsualUnaryConversions(FnExpr); 6958 6959 ExprOwningPtr<CXXOperatorCallExpr> 6960 TheCall(this, new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 6961 Args, 2, ResultTy, 6962 OpLoc)); 6963 6964 if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall.get(), 6965 FnDecl)) 6966 return ExprError(); 6967 6968 return MaybeBindToTemporary(TheCall.release()); 6969 } else { 6970 // We matched a built-in operator. Convert the arguments, then 6971 // break out so that we will build the appropriate built-in 6972 // operator node. 6973 if (PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 6974 Best->Conversions[0], AA_Passing) || 6975 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 6976 Best->Conversions[1], AA_Passing)) 6977 return ExprError(); 6978 6979 break; 6980 } 6981 } 6982 6983 case OR_No_Viable_Function: { 6984 // C++ [over.match.oper]p9: 6985 // If the operator is the operator , [...] and there are no 6986 // viable functions, then the operator is assumed to be the 6987 // built-in operator and interpreted according to clause 5. 6988 if (Opc == BinaryOperator::Comma) 6989 break; 6990 6991 // For class as left operand for assignment or compound assigment operator 6992 // do not fall through to handling in built-in, but report that no overloaded 6993 // assignment operator found 6994 OwningExprResult Result = ExprError(); 6995 if (Args[0]->getType()->isRecordType() && 6996 Opc >= BinaryOperator::Assign && Opc <= BinaryOperator::OrAssign) { 6997 Diag(OpLoc, diag::err_ovl_no_viable_oper) 6998 << BinaryOperator::getOpcodeStr(Opc) 6999 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 7000 } else { 7001 // No viable function; try to create a built-in operation, which will 7002 // produce an error. Then, show the non-viable candidates. 7003 Result = CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 7004 } 7005 assert(Result.isInvalid() && 7006 "C++ binary operator overloading is missing candidates!"); 7007 if (Result.isInvalid()) 7008 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2, 7009 BinaryOperator::getOpcodeStr(Opc), OpLoc); 7010 return move(Result); 7011 } 7012 7013 case OR_Ambiguous: 7014 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 7015 << BinaryOperator::getOpcodeStr(Opc) 7016 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 7017 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, 2, 7018 BinaryOperator::getOpcodeStr(Opc), OpLoc); 7019 return ExprError(); 7020 7021 case OR_Deleted: 7022 Diag(OpLoc, diag::err_ovl_deleted_oper) 7023 << Best->Function->isDeleted() 7024 << BinaryOperator::getOpcodeStr(Opc) 7025 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 7026 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2); 7027 return ExprError(); 7028 } 7029 7030 // We matched a built-in operator; build it. 7031 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 7032} 7033 7034Action::OwningExprResult 7035Sema::CreateOverloadedArraySubscriptExpr(SourceLocation LLoc, 7036 SourceLocation RLoc, 7037 ExprArg Base, ExprArg Idx) { 7038 Expr *Args[2] = { static_cast<Expr*>(Base.get()), 7039 static_cast<Expr*>(Idx.get()) }; 7040 DeclarationName OpName = 7041 Context.DeclarationNames.getCXXOperatorName(OO_Subscript); 7042 7043 // If either side is type-dependent, create an appropriate dependent 7044 // expression. 7045 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 7046 7047 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 7048 // CHECKME: no 'operator' keyword? 7049 DeclarationNameInfo OpNameInfo(OpName, LLoc); 7050 OpNameInfo.setCXXOperatorNameRange(SourceRange(LLoc, RLoc)); 7051 UnresolvedLookupExpr *Fn 7052 = UnresolvedLookupExpr::Create(Context, /*Dependent*/ true, NamingClass, 7053 0, SourceRange(), OpNameInfo, 7054 /*ADL*/ true, /*Overloaded*/ false, 7055 UnresolvedSetIterator(), 7056 UnresolvedSetIterator()); 7057 // Can't add any actual overloads yet 7058 7059 Base.release(); 7060 Idx.release(); 7061 return Owned(new (Context) CXXOperatorCallExpr(Context, OO_Subscript, Fn, 7062 Args, 2, 7063 Context.DependentTy, 7064 RLoc)); 7065 } 7066 7067 // Build an empty overload set. 7068 OverloadCandidateSet CandidateSet(LLoc); 7069 7070 // Subscript can only be overloaded as a member function. 7071 7072 // Add operator candidates that are member functions. 7073 AddMemberOperatorCandidates(OO_Subscript, LLoc, Args, 2, CandidateSet); 7074 7075 // Add builtin operator candidates. 7076 AddBuiltinOperatorCandidates(OO_Subscript, LLoc, Args, 2, CandidateSet); 7077 7078 // Perform overload resolution. 7079 OverloadCandidateSet::iterator Best; 7080 switch (BestViableFunction(CandidateSet, LLoc, Best)) { 7081 case OR_Success: { 7082 // We found a built-in operator or an overloaded operator. 7083 FunctionDecl *FnDecl = Best->Function; 7084 7085 if (FnDecl) { 7086 // We matched an overloaded operator. Build a call to that 7087 // operator. 7088 7089 CheckMemberOperatorAccess(LLoc, Args[0], Args[1], Best->FoundDecl); 7090 DiagnoseUseOfDecl(Best->FoundDecl, LLoc); 7091 7092 // Convert the arguments. 7093 CXXMethodDecl *Method = cast<CXXMethodDecl>(FnDecl); 7094 if (PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/0, 7095 Best->FoundDecl, Method)) 7096 return ExprError(); 7097 7098 // Convert the arguments. 7099 OwningExprResult InputInit 7100 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 7101 FnDecl->getParamDecl(0)), 7102 SourceLocation(), 7103 Owned(Args[1])); 7104 if (InputInit.isInvalid()) 7105 return ExprError(); 7106 7107 Args[1] = InputInit.takeAs<Expr>(); 7108 7109 // Determine the result type 7110 QualType ResultTy 7111 = FnDecl->getType()->getAs<FunctionType>() 7112 ->getCallResultType(Context); 7113 7114 // Build the actual expression node. 7115 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 7116 LLoc); 7117 UsualUnaryConversions(FnExpr); 7118 7119 Base.release(); 7120 Idx.release(); 7121 ExprOwningPtr<CXXOperatorCallExpr> 7122 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Subscript, 7123 FnExpr, Args, 2, 7124 ResultTy, RLoc)); 7125 7126 if (CheckCallReturnType(FnDecl->getResultType(), LLoc, TheCall.get(), 7127 FnDecl)) 7128 return ExprError(); 7129 7130 return MaybeBindToTemporary(TheCall.release()); 7131 } else { 7132 // We matched a built-in operator. Convert the arguments, then 7133 // break out so that we will build the appropriate built-in 7134 // operator node. 7135 if (PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 7136 Best->Conversions[0], AA_Passing) || 7137 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 7138 Best->Conversions[1], AA_Passing)) 7139 return ExprError(); 7140 7141 break; 7142 } 7143 } 7144 7145 case OR_No_Viable_Function: { 7146 if (CandidateSet.empty()) 7147 Diag(LLoc, diag::err_ovl_no_oper) 7148 << Args[0]->getType() << /*subscript*/ 0 7149 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 7150 else 7151 Diag(LLoc, diag::err_ovl_no_viable_subscript) 7152 << Args[0]->getType() 7153 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 7154 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2, 7155 "[]", LLoc); 7156 return ExprError(); 7157 } 7158 7159 case OR_Ambiguous: 7160 Diag(LLoc, diag::err_ovl_ambiguous_oper) 7161 << "[]" << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 7162 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, 2, 7163 "[]", LLoc); 7164 return ExprError(); 7165 7166 case OR_Deleted: 7167 Diag(LLoc, diag::err_ovl_deleted_oper) 7168 << Best->Function->isDeleted() << "[]" 7169 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 7170 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2, 7171 "[]", LLoc); 7172 return ExprError(); 7173 } 7174 7175 // We matched a built-in operator; build it. 7176 Base.release(); 7177 Idx.release(); 7178 return CreateBuiltinArraySubscriptExpr(Owned(Args[0]), LLoc, 7179 Owned(Args[1]), RLoc); 7180} 7181 7182/// BuildCallToMemberFunction - Build a call to a member 7183/// function. MemExpr is the expression that refers to the member 7184/// function (and includes the object parameter), Args/NumArgs are the 7185/// arguments to the function call (not including the object 7186/// parameter). The caller needs to validate that the member 7187/// expression refers to a member function or an overloaded member 7188/// function. 7189Sema::OwningExprResult 7190Sema::BuildCallToMemberFunction(Scope *S, Expr *MemExprE, 7191 SourceLocation LParenLoc, Expr **Args, 7192 unsigned NumArgs, SourceLocation *CommaLocs, 7193 SourceLocation RParenLoc) { 7194 // Dig out the member expression. This holds both the object 7195 // argument and the member function we're referring to. 7196 Expr *NakedMemExpr = MemExprE->IgnoreParens(); 7197 7198 MemberExpr *MemExpr; 7199 CXXMethodDecl *Method = 0; 7200 DeclAccessPair FoundDecl = DeclAccessPair::make(0, AS_public); 7201 NestedNameSpecifier *Qualifier = 0; 7202 if (isa<MemberExpr>(NakedMemExpr)) { 7203 MemExpr = cast<MemberExpr>(NakedMemExpr); 7204 Method = cast<CXXMethodDecl>(MemExpr->getMemberDecl()); 7205 FoundDecl = MemExpr->getFoundDecl(); 7206 Qualifier = MemExpr->getQualifier(); 7207 } else { 7208 UnresolvedMemberExpr *UnresExpr = cast<UnresolvedMemberExpr>(NakedMemExpr); 7209 Qualifier = UnresExpr->getQualifier(); 7210 7211 QualType ObjectType = UnresExpr->getBaseType(); 7212 7213 // Add overload candidates 7214 OverloadCandidateSet CandidateSet(UnresExpr->getMemberLoc()); 7215 7216 // FIXME: avoid copy. 7217 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 7218 if (UnresExpr->hasExplicitTemplateArgs()) { 7219 UnresExpr->copyTemplateArgumentsInto(TemplateArgsBuffer); 7220 TemplateArgs = &TemplateArgsBuffer; 7221 } 7222 7223 for (UnresolvedMemberExpr::decls_iterator I = UnresExpr->decls_begin(), 7224 E = UnresExpr->decls_end(); I != E; ++I) { 7225 7226 NamedDecl *Func = *I; 7227 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(Func->getDeclContext()); 7228 if (isa<UsingShadowDecl>(Func)) 7229 Func = cast<UsingShadowDecl>(Func)->getTargetDecl(); 7230 7231 if ((Method = dyn_cast<CXXMethodDecl>(Func))) { 7232 // If explicit template arguments were provided, we can't call a 7233 // non-template member function. 7234 if (TemplateArgs) 7235 continue; 7236 7237 AddMethodCandidate(Method, I.getPair(), ActingDC, ObjectType, 7238 Args, NumArgs, 7239 CandidateSet, /*SuppressUserConversions=*/false); 7240 } else { 7241 AddMethodTemplateCandidate(cast<FunctionTemplateDecl>(Func), 7242 I.getPair(), ActingDC, TemplateArgs, 7243 ObjectType, Args, NumArgs, 7244 CandidateSet, 7245 /*SuppressUsedConversions=*/false); 7246 } 7247 } 7248 7249 DeclarationName DeclName = UnresExpr->getMemberName(); 7250 7251 OverloadCandidateSet::iterator Best; 7252 switch (BestViableFunction(CandidateSet, UnresExpr->getLocStart(), Best)) { 7253 case OR_Success: 7254 Method = cast<CXXMethodDecl>(Best->Function); 7255 FoundDecl = Best->FoundDecl; 7256 CheckUnresolvedMemberAccess(UnresExpr, Best->FoundDecl); 7257 DiagnoseUseOfDecl(Best->FoundDecl, UnresExpr->getNameLoc()); 7258 break; 7259 7260 case OR_No_Viable_Function: 7261 Diag(UnresExpr->getMemberLoc(), 7262 diag::err_ovl_no_viable_member_function_in_call) 7263 << DeclName << MemExprE->getSourceRange(); 7264 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 7265 // FIXME: Leaking incoming expressions! 7266 return ExprError(); 7267 7268 case OR_Ambiguous: 7269 Diag(UnresExpr->getMemberLoc(), diag::err_ovl_ambiguous_member_call) 7270 << DeclName << MemExprE->getSourceRange(); 7271 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 7272 // FIXME: Leaking incoming expressions! 7273 return ExprError(); 7274 7275 case OR_Deleted: 7276 Diag(UnresExpr->getMemberLoc(), diag::err_ovl_deleted_member_call) 7277 << Best->Function->isDeleted() 7278 << DeclName << MemExprE->getSourceRange(); 7279 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 7280 // FIXME: Leaking incoming expressions! 7281 return ExprError(); 7282 } 7283 7284 MemExprE = FixOverloadedFunctionReference(MemExprE, FoundDecl, Method); 7285 7286 // If overload resolution picked a static member, build a 7287 // non-member call based on that function. 7288 if (Method->isStatic()) { 7289 return BuildResolvedCallExpr(MemExprE, Method, LParenLoc, 7290 Args, NumArgs, RParenLoc); 7291 } 7292 7293 MemExpr = cast<MemberExpr>(MemExprE->IgnoreParens()); 7294 } 7295 7296 assert(Method && "Member call to something that isn't a method?"); 7297 ExprOwningPtr<CXXMemberCallExpr> 7298 TheCall(this, new (Context) CXXMemberCallExpr(Context, MemExprE, Args, 7299 NumArgs, 7300 Method->getCallResultType(), 7301 RParenLoc)); 7302 7303 // Check for a valid return type. 7304 if (CheckCallReturnType(Method->getResultType(), MemExpr->getMemberLoc(), 7305 TheCall.get(), Method)) 7306 return ExprError(); 7307 7308 // Convert the object argument (for a non-static member function call). 7309 // We only need to do this if there was actually an overload; otherwise 7310 // it was done at lookup. 7311 Expr *ObjectArg = MemExpr->getBase(); 7312 if (!Method->isStatic() && 7313 PerformObjectArgumentInitialization(ObjectArg, Qualifier, 7314 FoundDecl, Method)) 7315 return ExprError(); 7316 MemExpr->setBase(ObjectArg); 7317 7318 // Convert the rest of the arguments 7319 const FunctionProtoType *Proto = Method->getType()->getAs<FunctionProtoType>(); 7320 if (ConvertArgumentsForCall(&*TheCall, MemExpr, Method, Proto, Args, NumArgs, 7321 RParenLoc)) 7322 return ExprError(); 7323 7324 if (CheckFunctionCall(Method, TheCall.get())) 7325 return ExprError(); 7326 7327 return MaybeBindToTemporary(TheCall.release()); 7328} 7329 7330/// BuildCallToObjectOfClassType - Build a call to an object of class 7331/// type (C++ [over.call.object]), which can end up invoking an 7332/// overloaded function call operator (@c operator()) or performing a 7333/// user-defined conversion on the object argument. 7334Sema::ExprResult 7335Sema::BuildCallToObjectOfClassType(Scope *S, Expr *Object, 7336 SourceLocation LParenLoc, 7337 Expr **Args, unsigned NumArgs, 7338 SourceLocation *CommaLocs, 7339 SourceLocation RParenLoc) { 7340 assert(Object->getType()->isRecordType() && "Requires object type argument"); 7341 const RecordType *Record = Object->getType()->getAs<RecordType>(); 7342 7343 // C++ [over.call.object]p1: 7344 // If the primary-expression E in the function call syntax 7345 // evaluates to a class object of type "cv T", then the set of 7346 // candidate functions includes at least the function call 7347 // operators of T. The function call operators of T are obtained by 7348 // ordinary lookup of the name operator() in the context of 7349 // (E).operator(). 7350 OverloadCandidateSet CandidateSet(LParenLoc); 7351 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Call); 7352 7353 if (RequireCompleteType(LParenLoc, Object->getType(), 7354 PDiag(diag::err_incomplete_object_call) 7355 << Object->getSourceRange())) 7356 return true; 7357 7358 LookupResult R(*this, OpName, LParenLoc, LookupOrdinaryName); 7359 LookupQualifiedName(R, Record->getDecl()); 7360 R.suppressDiagnostics(); 7361 7362 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 7363 Oper != OperEnd; ++Oper) { 7364 AddMethodCandidate(Oper.getPair(), Object->getType(), 7365 Args, NumArgs, CandidateSet, 7366 /*SuppressUserConversions=*/ false); 7367 } 7368 7369 // C++ [over.call.object]p2: 7370 // In addition, for each conversion function declared in T of the 7371 // form 7372 // 7373 // operator conversion-type-id () cv-qualifier; 7374 // 7375 // where cv-qualifier is the same cv-qualification as, or a 7376 // greater cv-qualification than, cv, and where conversion-type-id 7377 // denotes the type "pointer to function of (P1,...,Pn) returning 7378 // R", or the type "reference to pointer to function of 7379 // (P1,...,Pn) returning R", or the type "reference to function 7380 // of (P1,...,Pn) returning R", a surrogate call function [...] 7381 // is also considered as a candidate function. Similarly, 7382 // surrogate call functions are added to the set of candidate 7383 // functions for each conversion function declared in an 7384 // accessible base class provided the function is not hidden 7385 // within T by another intervening declaration. 7386 const UnresolvedSetImpl *Conversions 7387 = cast<CXXRecordDecl>(Record->getDecl())->getVisibleConversionFunctions(); 7388 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 7389 E = Conversions->end(); I != E; ++I) { 7390 NamedDecl *D = *I; 7391 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext()); 7392 if (isa<UsingShadowDecl>(D)) 7393 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 7394 7395 // Skip over templated conversion functions; they aren't 7396 // surrogates. 7397 if (isa<FunctionTemplateDecl>(D)) 7398 continue; 7399 7400 CXXConversionDecl *Conv = cast<CXXConversionDecl>(D); 7401 7402 // Strip the reference type (if any) and then the pointer type (if 7403 // any) to get down to what might be a function type. 7404 QualType ConvType = Conv->getConversionType().getNonReferenceType(); 7405 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 7406 ConvType = ConvPtrType->getPointeeType(); 7407 7408 if (const FunctionProtoType *Proto = ConvType->getAs<FunctionProtoType>()) 7409 AddSurrogateCandidate(Conv, I.getPair(), ActingContext, Proto, 7410 Object->getType(), Args, NumArgs, 7411 CandidateSet); 7412 } 7413 7414 // Perform overload resolution. 7415 OverloadCandidateSet::iterator Best; 7416 switch (BestViableFunction(CandidateSet, Object->getLocStart(), Best)) { 7417 case OR_Success: 7418 // Overload resolution succeeded; we'll build the appropriate call 7419 // below. 7420 break; 7421 7422 case OR_No_Viable_Function: 7423 if (CandidateSet.empty()) 7424 Diag(Object->getSourceRange().getBegin(), diag::err_ovl_no_oper) 7425 << Object->getType() << /*call*/ 1 7426 << Object->getSourceRange(); 7427 else 7428 Diag(Object->getSourceRange().getBegin(), 7429 diag::err_ovl_no_viable_object_call) 7430 << Object->getType() << Object->getSourceRange(); 7431 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 7432 break; 7433 7434 case OR_Ambiguous: 7435 Diag(Object->getSourceRange().getBegin(), 7436 diag::err_ovl_ambiguous_object_call) 7437 << Object->getType() << Object->getSourceRange(); 7438 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, NumArgs); 7439 break; 7440 7441 case OR_Deleted: 7442 Diag(Object->getSourceRange().getBegin(), 7443 diag::err_ovl_deleted_object_call) 7444 << Best->Function->isDeleted() 7445 << Object->getType() << Object->getSourceRange(); 7446 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 7447 break; 7448 } 7449 7450 if (Best == CandidateSet.end()) 7451 return true; 7452 7453 if (Best->Function == 0) { 7454 // Since there is no function declaration, this is one of the 7455 // surrogate candidates. Dig out the conversion function. 7456 CXXConversionDecl *Conv 7457 = cast<CXXConversionDecl>( 7458 Best->Conversions[0].UserDefined.ConversionFunction); 7459 7460 CheckMemberOperatorAccess(LParenLoc, Object, 0, Best->FoundDecl); 7461 DiagnoseUseOfDecl(Best->FoundDecl, LParenLoc); 7462 7463 // We selected one of the surrogate functions that converts the 7464 // object parameter to a function pointer. Perform the conversion 7465 // on the object argument, then let ActOnCallExpr finish the job. 7466 7467 // Create an implicit member expr to refer to the conversion operator. 7468 // and then call it. 7469 CXXMemberCallExpr *CE = BuildCXXMemberCallExpr(Object, Best->FoundDecl, 7470 Conv); 7471 7472 return ActOnCallExpr(S, ExprArg(*this, CE), LParenLoc, 7473 MultiExprArg(*this, (ExprTy**)Args, NumArgs), 7474 CommaLocs, RParenLoc).result(); 7475 } 7476 7477 CheckMemberOperatorAccess(LParenLoc, Object, 0, Best->FoundDecl); 7478 DiagnoseUseOfDecl(Best->FoundDecl, LParenLoc); 7479 7480 // We found an overloaded operator(). Build a CXXOperatorCallExpr 7481 // that calls this method, using Object for the implicit object 7482 // parameter and passing along the remaining arguments. 7483 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 7484 const FunctionProtoType *Proto = Method->getType()->getAs<FunctionProtoType>(); 7485 7486 unsigned NumArgsInProto = Proto->getNumArgs(); 7487 unsigned NumArgsToCheck = NumArgs; 7488 7489 // Build the full argument list for the method call (the 7490 // implicit object parameter is placed at the beginning of the 7491 // list). 7492 Expr **MethodArgs; 7493 if (NumArgs < NumArgsInProto) { 7494 NumArgsToCheck = NumArgsInProto; 7495 MethodArgs = new Expr*[NumArgsInProto + 1]; 7496 } else { 7497 MethodArgs = new Expr*[NumArgs + 1]; 7498 } 7499 MethodArgs[0] = Object; 7500 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 7501 MethodArgs[ArgIdx + 1] = Args[ArgIdx]; 7502 7503 Expr *NewFn = new (Context) DeclRefExpr(Method, Method->getType(), 7504 SourceLocation()); 7505 UsualUnaryConversions(NewFn); 7506 7507 // Once we've built TheCall, all of the expressions are properly 7508 // owned. 7509 QualType ResultTy = Method->getCallResultType(); 7510 ExprOwningPtr<CXXOperatorCallExpr> 7511 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Call, NewFn, 7512 MethodArgs, NumArgs + 1, 7513 ResultTy, RParenLoc)); 7514 delete [] MethodArgs; 7515 7516 if (CheckCallReturnType(Method->getResultType(), LParenLoc, TheCall.get(), 7517 Method)) 7518 return true; 7519 7520 // We may have default arguments. If so, we need to allocate more 7521 // slots in the call for them. 7522 if (NumArgs < NumArgsInProto) 7523 TheCall->setNumArgs(Context, NumArgsInProto + 1); 7524 else if (NumArgs > NumArgsInProto) 7525 NumArgsToCheck = NumArgsInProto; 7526 7527 bool IsError = false; 7528 7529 // Initialize the implicit object parameter. 7530 IsError |= PerformObjectArgumentInitialization(Object, /*Qualifier=*/0, 7531 Best->FoundDecl, Method); 7532 TheCall->setArg(0, Object); 7533 7534 7535 // Check the argument types. 7536 for (unsigned i = 0; i != NumArgsToCheck; i++) { 7537 Expr *Arg; 7538 if (i < NumArgs) { 7539 Arg = Args[i]; 7540 7541 // Pass the argument. 7542 7543 OwningExprResult InputInit 7544 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 7545 Method->getParamDecl(i)), 7546 SourceLocation(), Owned(Arg)); 7547 7548 IsError |= InputInit.isInvalid(); 7549 Arg = InputInit.takeAs<Expr>(); 7550 } else { 7551 OwningExprResult DefArg 7552 = BuildCXXDefaultArgExpr(LParenLoc, Method, Method->getParamDecl(i)); 7553 if (DefArg.isInvalid()) { 7554 IsError = true; 7555 break; 7556 } 7557 7558 Arg = DefArg.takeAs<Expr>(); 7559 } 7560 7561 TheCall->setArg(i + 1, Arg); 7562 } 7563 7564 // If this is a variadic call, handle args passed through "...". 7565 if (Proto->isVariadic()) { 7566 // Promote the arguments (C99 6.5.2.2p7). 7567 for (unsigned i = NumArgsInProto; i != NumArgs; i++) { 7568 Expr *Arg = Args[i]; 7569 IsError |= DefaultVariadicArgumentPromotion(Arg, VariadicMethod, 0); 7570 TheCall->setArg(i + 1, Arg); 7571 } 7572 } 7573 7574 if (IsError) return true; 7575 7576 if (CheckFunctionCall(Method, TheCall.get())) 7577 return true; 7578 7579 return MaybeBindToTemporary(TheCall.release()).result(); 7580} 7581 7582/// BuildOverloadedArrowExpr - Build a call to an overloaded @c operator-> 7583/// (if one exists), where @c Base is an expression of class type and 7584/// @c Member is the name of the member we're trying to find. 7585Sema::OwningExprResult 7586Sema::BuildOverloadedArrowExpr(Scope *S, ExprArg BaseIn, SourceLocation OpLoc) { 7587 Expr *Base = static_cast<Expr *>(BaseIn.get()); 7588 assert(Base->getType()->isRecordType() && "left-hand side must have class type"); 7589 7590 SourceLocation Loc = Base->getExprLoc(); 7591 7592 // C++ [over.ref]p1: 7593 // 7594 // [...] An expression x->m is interpreted as (x.operator->())->m 7595 // for a class object x of type T if T::operator->() exists and if 7596 // the operator is selected as the best match function by the 7597 // overload resolution mechanism (13.3). 7598 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Arrow); 7599 OverloadCandidateSet CandidateSet(Loc); 7600 const RecordType *BaseRecord = Base->getType()->getAs<RecordType>(); 7601 7602 if (RequireCompleteType(Loc, Base->getType(), 7603 PDiag(diag::err_typecheck_incomplete_tag) 7604 << Base->getSourceRange())) 7605 return ExprError(); 7606 7607 LookupResult R(*this, OpName, OpLoc, LookupOrdinaryName); 7608 LookupQualifiedName(R, BaseRecord->getDecl()); 7609 R.suppressDiagnostics(); 7610 7611 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 7612 Oper != OperEnd; ++Oper) { 7613 AddMethodCandidate(Oper.getPair(), Base->getType(), 0, 0, CandidateSet, 7614 /*SuppressUserConversions=*/false); 7615 } 7616 7617 // Perform overload resolution. 7618 OverloadCandidateSet::iterator Best; 7619 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 7620 case OR_Success: 7621 // Overload resolution succeeded; we'll build the call below. 7622 break; 7623 7624 case OR_No_Viable_Function: 7625 if (CandidateSet.empty()) 7626 Diag(OpLoc, diag::err_typecheck_member_reference_arrow) 7627 << Base->getType() << Base->getSourceRange(); 7628 else 7629 Diag(OpLoc, diag::err_ovl_no_viable_oper) 7630 << "operator->" << Base->getSourceRange(); 7631 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, &Base, 1); 7632 return ExprError(); 7633 7634 case OR_Ambiguous: 7635 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 7636 << "->" << Base->getSourceRange(); 7637 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, &Base, 1); 7638 return ExprError(); 7639 7640 case OR_Deleted: 7641 Diag(OpLoc, diag::err_ovl_deleted_oper) 7642 << Best->Function->isDeleted() 7643 << "->" << Base->getSourceRange(); 7644 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, &Base, 1); 7645 return ExprError(); 7646 } 7647 7648 CheckMemberOperatorAccess(OpLoc, Base, 0, Best->FoundDecl); 7649 DiagnoseUseOfDecl(Best->FoundDecl, OpLoc); 7650 7651 // Convert the object parameter. 7652 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 7653 if (PerformObjectArgumentInitialization(Base, /*Qualifier=*/0, 7654 Best->FoundDecl, Method)) 7655 return ExprError(); 7656 7657 // No concerns about early exits now. 7658 BaseIn.release(); 7659 7660 // Build the operator call. 7661 Expr *FnExpr = new (Context) DeclRefExpr(Method, Method->getType(), 7662 SourceLocation()); 7663 UsualUnaryConversions(FnExpr); 7664 7665 QualType ResultTy = Method->getCallResultType(); 7666 ExprOwningPtr<CXXOperatorCallExpr> 7667 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Arrow, FnExpr, 7668 &Base, 1, ResultTy, OpLoc)); 7669 7670 if (CheckCallReturnType(Method->getResultType(), OpLoc, TheCall.get(), 7671 Method)) 7672 return ExprError(); 7673 return move(TheCall); 7674} 7675 7676/// FixOverloadedFunctionReference - E is an expression that refers to 7677/// a C++ overloaded function (possibly with some parentheses and 7678/// perhaps a '&' around it). We have resolved the overloaded function 7679/// to the function declaration Fn, so patch up the expression E to 7680/// refer (possibly indirectly) to Fn. Returns the new expr. 7681Expr *Sema::FixOverloadedFunctionReference(Expr *E, DeclAccessPair Found, 7682 FunctionDecl *Fn) { 7683 if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) { 7684 Expr *SubExpr = FixOverloadedFunctionReference(PE->getSubExpr(), 7685 Found, Fn); 7686 if (SubExpr == PE->getSubExpr()) 7687 return PE->Retain(); 7688 7689 return new (Context) ParenExpr(PE->getLParen(), PE->getRParen(), SubExpr); 7690 } 7691 7692 if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) { 7693 Expr *SubExpr = FixOverloadedFunctionReference(ICE->getSubExpr(), 7694 Found, Fn); 7695 assert(Context.hasSameType(ICE->getSubExpr()->getType(), 7696 SubExpr->getType()) && 7697 "Implicit cast type cannot be determined from overload"); 7698 assert(ICE->path_empty() && "fixing up hierarchy conversion?"); 7699 if (SubExpr == ICE->getSubExpr()) 7700 return ICE->Retain(); 7701 7702 return ImplicitCastExpr::Create(Context, ICE->getType(), 7703 ICE->getCastKind(), 7704 SubExpr, 0, 7705 ICE->getCategory()); 7706 } 7707 7708 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(E)) { 7709 assert(UnOp->getOpcode() == UnaryOperator::AddrOf && 7710 "Can only take the address of an overloaded function"); 7711 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 7712 if (Method->isStatic()) { 7713 // Do nothing: static member functions aren't any different 7714 // from non-member functions. 7715 } else { 7716 // Fix the sub expression, which really has to be an 7717 // UnresolvedLookupExpr holding an overloaded member function 7718 // or template. 7719 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(), 7720 Found, Fn); 7721 if (SubExpr == UnOp->getSubExpr()) 7722 return UnOp->Retain(); 7723 7724 assert(isa<DeclRefExpr>(SubExpr) 7725 && "fixed to something other than a decl ref"); 7726 assert(cast<DeclRefExpr>(SubExpr)->getQualifier() 7727 && "fixed to a member ref with no nested name qualifier"); 7728 7729 // We have taken the address of a pointer to member 7730 // function. Perform the computation here so that we get the 7731 // appropriate pointer to member type. 7732 QualType ClassType 7733 = Context.getTypeDeclType(cast<RecordDecl>(Method->getDeclContext())); 7734 QualType MemPtrType 7735 = Context.getMemberPointerType(Fn->getType(), ClassType.getTypePtr()); 7736 7737 return new (Context) UnaryOperator(SubExpr, UnaryOperator::AddrOf, 7738 MemPtrType, UnOp->getOperatorLoc()); 7739 } 7740 } 7741 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(), 7742 Found, Fn); 7743 if (SubExpr == UnOp->getSubExpr()) 7744 return UnOp->Retain(); 7745 7746 return new (Context) UnaryOperator(SubExpr, UnaryOperator::AddrOf, 7747 Context.getPointerType(SubExpr->getType()), 7748 UnOp->getOperatorLoc()); 7749 } 7750 7751 if (UnresolvedLookupExpr *ULE = dyn_cast<UnresolvedLookupExpr>(E)) { 7752 // FIXME: avoid copy. 7753 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 7754 if (ULE->hasExplicitTemplateArgs()) { 7755 ULE->copyTemplateArgumentsInto(TemplateArgsBuffer); 7756 TemplateArgs = &TemplateArgsBuffer; 7757 } 7758 7759 return DeclRefExpr::Create(Context, 7760 ULE->getQualifier(), 7761 ULE->getQualifierRange(), 7762 Fn, 7763 ULE->getNameLoc(), 7764 Fn->getType(), 7765 TemplateArgs); 7766 } 7767 7768 if (UnresolvedMemberExpr *MemExpr = dyn_cast<UnresolvedMemberExpr>(E)) { 7769 // FIXME: avoid copy. 7770 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 7771 if (MemExpr->hasExplicitTemplateArgs()) { 7772 MemExpr->copyTemplateArgumentsInto(TemplateArgsBuffer); 7773 TemplateArgs = &TemplateArgsBuffer; 7774 } 7775 7776 Expr *Base; 7777 7778 // If we're filling in 7779 if (MemExpr->isImplicitAccess()) { 7780 if (cast<CXXMethodDecl>(Fn)->isStatic()) { 7781 return DeclRefExpr::Create(Context, 7782 MemExpr->getQualifier(), 7783 MemExpr->getQualifierRange(), 7784 Fn, 7785 MemExpr->getMemberLoc(), 7786 Fn->getType(), 7787 TemplateArgs); 7788 } else { 7789 SourceLocation Loc = MemExpr->getMemberLoc(); 7790 if (MemExpr->getQualifier()) 7791 Loc = MemExpr->getQualifierRange().getBegin(); 7792 Base = new (Context) CXXThisExpr(Loc, 7793 MemExpr->getBaseType(), 7794 /*isImplicit=*/true); 7795 } 7796 } else 7797 Base = MemExpr->getBase()->Retain(); 7798 7799 return MemberExpr::Create(Context, Base, 7800 MemExpr->isArrow(), 7801 MemExpr->getQualifier(), 7802 MemExpr->getQualifierRange(), 7803 Fn, 7804 Found, 7805 MemExpr->getMemberNameInfo(), 7806 TemplateArgs, 7807 Fn->getType()); 7808 } 7809 7810 assert(false && "Invalid reference to overloaded function"); 7811 return E->Retain(); 7812} 7813 7814Sema::OwningExprResult Sema::FixOverloadedFunctionReference(OwningExprResult E, 7815 DeclAccessPair Found, 7816 FunctionDecl *Fn) { 7817 return Owned(FixOverloadedFunctionReference((Expr *)E.get(), Found, Fn)); 7818} 7819 7820} // end namespace clang 7821