SemaOverload.cpp revision 9ae2f076ca5ab1feb3ba95629099ec2319833701
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 "clang/Sema/Sema.h" 15#include "clang/Sema/Lookup.h" 16#include "clang/Sema/Initialization.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 // If the unqualified pointee types are the same, this can't be a 1410 // pointer conversion, so don't do all of the work below. 1411 if (Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType)) 1412 return false; 1413 1414 // An rvalue of type "pointer to cv T," where T is an object type, 1415 // can be converted to an rvalue of type "pointer to cv void" (C++ 1416 // 4.10p2). 1417 if (FromPointeeType->isIncompleteOrObjectType() && 1418 ToPointeeType->isVoidType()) { 1419 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1420 ToPointeeType, 1421 ToType, Context); 1422 return true; 1423 } 1424 1425 // When we're overloading in C, we allow a special kind of pointer 1426 // conversion for compatible-but-not-identical pointee types. 1427 if (!getLangOptions().CPlusPlus && 1428 Context.typesAreCompatible(FromPointeeType, ToPointeeType)) { 1429 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1430 ToPointeeType, 1431 ToType, Context); 1432 return true; 1433 } 1434 1435 // C++ [conv.ptr]p3: 1436 // 1437 // An rvalue of type "pointer to cv D," where D is a class type, 1438 // can be converted to an rvalue of type "pointer to cv B," where 1439 // B is a base class (clause 10) of D. If B is an inaccessible 1440 // (clause 11) or ambiguous (10.2) base class of D, a program that 1441 // necessitates this conversion is ill-formed. The result of the 1442 // conversion is a pointer to the base class sub-object of the 1443 // derived class object. The null pointer value is converted to 1444 // the null pointer value of the destination type. 1445 // 1446 // Note that we do not check for ambiguity or inaccessibility 1447 // here. That is handled by CheckPointerConversion. 1448 if (getLangOptions().CPlusPlus && 1449 FromPointeeType->isRecordType() && ToPointeeType->isRecordType() && 1450 !Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType) && 1451 !RequireCompleteType(From->getLocStart(), FromPointeeType, PDiag()) && 1452 IsDerivedFrom(FromPointeeType, ToPointeeType)) { 1453 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1454 ToPointeeType, 1455 ToType, Context); 1456 return true; 1457 } 1458 1459 return false; 1460} 1461 1462/// isObjCPointerConversion - Determines whether this is an 1463/// Objective-C pointer conversion. Subroutine of IsPointerConversion, 1464/// with the same arguments and return values. 1465bool Sema::isObjCPointerConversion(QualType FromType, QualType ToType, 1466 QualType& ConvertedType, 1467 bool &IncompatibleObjC) { 1468 if (!getLangOptions().ObjC1) 1469 return false; 1470 1471 // First, we handle all conversions on ObjC object pointer types. 1472 const ObjCObjectPointerType* ToObjCPtr = ToType->getAs<ObjCObjectPointerType>(); 1473 const ObjCObjectPointerType *FromObjCPtr = 1474 FromType->getAs<ObjCObjectPointerType>(); 1475 1476 if (ToObjCPtr && FromObjCPtr) { 1477 // Objective C++: We're able to convert between "id" or "Class" and a 1478 // pointer to any interface (in both directions). 1479 if (ToObjCPtr->isObjCBuiltinType() && FromObjCPtr->isObjCBuiltinType()) { 1480 ConvertedType = ToType; 1481 return true; 1482 } 1483 // Conversions with Objective-C's id<...>. 1484 if ((FromObjCPtr->isObjCQualifiedIdType() || 1485 ToObjCPtr->isObjCQualifiedIdType()) && 1486 Context.ObjCQualifiedIdTypesAreCompatible(ToType, FromType, 1487 /*compare=*/false)) { 1488 ConvertedType = ToType; 1489 return true; 1490 } 1491 // Objective C++: We're able to convert from a pointer to an 1492 // interface to a pointer to a different interface. 1493 if (Context.canAssignObjCInterfaces(ToObjCPtr, FromObjCPtr)) { 1494 const ObjCInterfaceType* LHS = ToObjCPtr->getInterfaceType(); 1495 const ObjCInterfaceType* RHS = FromObjCPtr->getInterfaceType(); 1496 if (getLangOptions().CPlusPlus && LHS && RHS && 1497 !ToObjCPtr->getPointeeType().isAtLeastAsQualifiedAs( 1498 FromObjCPtr->getPointeeType())) 1499 return false; 1500 ConvertedType = ToType; 1501 return true; 1502 } 1503 1504 if (Context.canAssignObjCInterfaces(FromObjCPtr, ToObjCPtr)) { 1505 // Okay: this is some kind of implicit downcast of Objective-C 1506 // interfaces, which is permitted. However, we're going to 1507 // complain about it. 1508 IncompatibleObjC = true; 1509 ConvertedType = FromType; 1510 return true; 1511 } 1512 } 1513 // Beyond this point, both types need to be C pointers or block pointers. 1514 QualType ToPointeeType; 1515 if (const PointerType *ToCPtr = ToType->getAs<PointerType>()) 1516 ToPointeeType = ToCPtr->getPointeeType(); 1517 else if (const BlockPointerType *ToBlockPtr = 1518 ToType->getAs<BlockPointerType>()) { 1519 // Objective C++: We're able to convert from a pointer to any object 1520 // to a block pointer type. 1521 if (FromObjCPtr && FromObjCPtr->isObjCBuiltinType()) { 1522 ConvertedType = ToType; 1523 return true; 1524 } 1525 ToPointeeType = ToBlockPtr->getPointeeType(); 1526 } 1527 else if (FromType->getAs<BlockPointerType>() && 1528 ToObjCPtr && ToObjCPtr->isObjCBuiltinType()) { 1529 // Objective C++: We're able to convert from a block pointer type to a 1530 // pointer to any object. 1531 ConvertedType = ToType; 1532 return true; 1533 } 1534 else 1535 return false; 1536 1537 QualType FromPointeeType; 1538 if (const PointerType *FromCPtr = FromType->getAs<PointerType>()) 1539 FromPointeeType = FromCPtr->getPointeeType(); 1540 else if (const BlockPointerType *FromBlockPtr = FromType->getAs<BlockPointerType>()) 1541 FromPointeeType = FromBlockPtr->getPointeeType(); 1542 else 1543 return false; 1544 1545 // If we have pointers to pointers, recursively check whether this 1546 // is an Objective-C conversion. 1547 if (FromPointeeType->isPointerType() && ToPointeeType->isPointerType() && 1548 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, 1549 IncompatibleObjC)) { 1550 // We always complain about this conversion. 1551 IncompatibleObjC = true; 1552 ConvertedType = ToType; 1553 return true; 1554 } 1555 // Allow conversion of pointee being objective-c pointer to another one; 1556 // as in I* to id. 1557 if (FromPointeeType->getAs<ObjCObjectPointerType>() && 1558 ToPointeeType->getAs<ObjCObjectPointerType>() && 1559 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, 1560 IncompatibleObjC)) { 1561 ConvertedType = ToType; 1562 return true; 1563 } 1564 1565 // If we have pointers to functions or blocks, check whether the only 1566 // differences in the argument and result types are in Objective-C 1567 // pointer conversions. If so, we permit the conversion (but 1568 // complain about it). 1569 const FunctionProtoType *FromFunctionType 1570 = FromPointeeType->getAs<FunctionProtoType>(); 1571 const FunctionProtoType *ToFunctionType 1572 = ToPointeeType->getAs<FunctionProtoType>(); 1573 if (FromFunctionType && ToFunctionType) { 1574 // If the function types are exactly the same, this isn't an 1575 // Objective-C pointer conversion. 1576 if (Context.getCanonicalType(FromPointeeType) 1577 == Context.getCanonicalType(ToPointeeType)) 1578 return false; 1579 1580 // Perform the quick checks that will tell us whether these 1581 // function types are obviously different. 1582 if (FromFunctionType->getNumArgs() != ToFunctionType->getNumArgs() || 1583 FromFunctionType->isVariadic() != ToFunctionType->isVariadic() || 1584 FromFunctionType->getTypeQuals() != ToFunctionType->getTypeQuals()) 1585 return false; 1586 1587 bool HasObjCConversion = false; 1588 if (Context.getCanonicalType(FromFunctionType->getResultType()) 1589 == Context.getCanonicalType(ToFunctionType->getResultType())) { 1590 // Okay, the types match exactly. Nothing to do. 1591 } else if (isObjCPointerConversion(FromFunctionType->getResultType(), 1592 ToFunctionType->getResultType(), 1593 ConvertedType, IncompatibleObjC)) { 1594 // Okay, we have an Objective-C pointer conversion. 1595 HasObjCConversion = true; 1596 } else { 1597 // Function types are too different. Abort. 1598 return false; 1599 } 1600 1601 // Check argument types. 1602 for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumArgs(); 1603 ArgIdx != NumArgs; ++ArgIdx) { 1604 QualType FromArgType = FromFunctionType->getArgType(ArgIdx); 1605 QualType ToArgType = ToFunctionType->getArgType(ArgIdx); 1606 if (Context.getCanonicalType(FromArgType) 1607 == Context.getCanonicalType(ToArgType)) { 1608 // Okay, the types match exactly. Nothing to do. 1609 } else if (isObjCPointerConversion(FromArgType, ToArgType, 1610 ConvertedType, IncompatibleObjC)) { 1611 // Okay, we have an Objective-C pointer conversion. 1612 HasObjCConversion = true; 1613 } else { 1614 // Argument types are too different. Abort. 1615 return false; 1616 } 1617 } 1618 1619 if (HasObjCConversion) { 1620 // We had an Objective-C conversion. Allow this pointer 1621 // conversion, but complain about it. 1622 ConvertedType = ToType; 1623 IncompatibleObjC = true; 1624 return true; 1625 } 1626 } 1627 1628 return false; 1629} 1630 1631/// FunctionArgTypesAreEqual - This routine checks two function proto types 1632/// for equlity of their argument types. Caller has already checked that 1633/// they have same number of arguments. This routine assumes that Objective-C 1634/// pointer types which only differ in their protocol qualifiers are equal. 1635bool Sema::FunctionArgTypesAreEqual(FunctionProtoType* OldType, 1636 FunctionProtoType* NewType){ 1637 if (!getLangOptions().ObjC1) 1638 return std::equal(OldType->arg_type_begin(), OldType->arg_type_end(), 1639 NewType->arg_type_begin()); 1640 1641 for (FunctionProtoType::arg_type_iterator O = OldType->arg_type_begin(), 1642 N = NewType->arg_type_begin(), 1643 E = OldType->arg_type_end(); O && (O != E); ++O, ++N) { 1644 QualType ToType = (*O); 1645 QualType FromType = (*N); 1646 if (ToType != FromType) { 1647 if (const PointerType *PTTo = ToType->getAs<PointerType>()) { 1648 if (const PointerType *PTFr = FromType->getAs<PointerType>()) 1649 if ((PTTo->getPointeeType()->isObjCQualifiedIdType() && 1650 PTFr->getPointeeType()->isObjCQualifiedIdType()) || 1651 (PTTo->getPointeeType()->isObjCQualifiedClassType() && 1652 PTFr->getPointeeType()->isObjCQualifiedClassType())) 1653 continue; 1654 } 1655 else if (const ObjCObjectPointerType *PTTo = 1656 ToType->getAs<ObjCObjectPointerType>()) { 1657 if (const ObjCObjectPointerType *PTFr = 1658 FromType->getAs<ObjCObjectPointerType>()) 1659 if (PTTo->getInterfaceDecl() == PTFr->getInterfaceDecl()) 1660 continue; 1661 } 1662 return false; 1663 } 1664 } 1665 return true; 1666} 1667 1668/// CheckPointerConversion - Check the pointer conversion from the 1669/// expression From to the type ToType. This routine checks for 1670/// ambiguous or inaccessible derived-to-base pointer 1671/// conversions for which IsPointerConversion has already returned 1672/// true. It returns true and produces a diagnostic if there was an 1673/// error, or returns false otherwise. 1674bool Sema::CheckPointerConversion(Expr *From, QualType ToType, 1675 CastExpr::CastKind &Kind, 1676 CXXCastPath& BasePath, 1677 bool IgnoreBaseAccess) { 1678 QualType FromType = From->getType(); 1679 1680 if (CXXBoolLiteralExpr* LitBool 1681 = dyn_cast<CXXBoolLiteralExpr>(From->IgnoreParens())) 1682 if (LitBool->getValue() == false) 1683 Diag(LitBool->getExprLoc(), diag::warn_init_pointer_from_false) 1684 << ToType; 1685 1686 if (const PointerType *FromPtrType = FromType->getAs<PointerType>()) 1687 if (const PointerType *ToPtrType = ToType->getAs<PointerType>()) { 1688 QualType FromPointeeType = FromPtrType->getPointeeType(), 1689 ToPointeeType = ToPtrType->getPointeeType(); 1690 1691 if (FromPointeeType->isRecordType() && ToPointeeType->isRecordType() && 1692 !Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType)) { 1693 // We must have a derived-to-base conversion. Check an 1694 // ambiguous or inaccessible conversion. 1695 if (CheckDerivedToBaseConversion(FromPointeeType, ToPointeeType, 1696 From->getExprLoc(), 1697 From->getSourceRange(), &BasePath, 1698 IgnoreBaseAccess)) 1699 return true; 1700 1701 // The conversion was successful. 1702 Kind = CastExpr::CK_DerivedToBase; 1703 } 1704 } 1705 if (const ObjCObjectPointerType *FromPtrType = 1706 FromType->getAs<ObjCObjectPointerType>()) 1707 if (const ObjCObjectPointerType *ToPtrType = 1708 ToType->getAs<ObjCObjectPointerType>()) { 1709 // Objective-C++ conversions are always okay. 1710 // FIXME: We should have a different class of conversions for the 1711 // Objective-C++ implicit conversions. 1712 if (FromPtrType->isObjCBuiltinType() || ToPtrType->isObjCBuiltinType()) 1713 return false; 1714 1715 } 1716 return false; 1717} 1718 1719/// IsMemberPointerConversion - Determines whether the conversion of the 1720/// expression From, which has the (possibly adjusted) type FromType, can be 1721/// converted to the type ToType via a member pointer conversion (C++ 4.11). 1722/// If so, returns true and places the converted type (that might differ from 1723/// ToType in its cv-qualifiers at some level) into ConvertedType. 1724bool Sema::IsMemberPointerConversion(Expr *From, QualType FromType, 1725 QualType ToType, 1726 bool InOverloadResolution, 1727 QualType &ConvertedType) { 1728 const MemberPointerType *ToTypePtr = ToType->getAs<MemberPointerType>(); 1729 if (!ToTypePtr) 1730 return false; 1731 1732 // A null pointer constant can be converted to a member pointer (C++ 4.11p1) 1733 if (From->isNullPointerConstant(Context, 1734 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull 1735 : Expr::NPC_ValueDependentIsNull)) { 1736 ConvertedType = ToType; 1737 return true; 1738 } 1739 1740 // Otherwise, both types have to be member pointers. 1741 const MemberPointerType *FromTypePtr = FromType->getAs<MemberPointerType>(); 1742 if (!FromTypePtr) 1743 return false; 1744 1745 // A pointer to member of B can be converted to a pointer to member of D, 1746 // where D is derived from B (C++ 4.11p2). 1747 QualType FromClass(FromTypePtr->getClass(), 0); 1748 QualType ToClass(ToTypePtr->getClass(), 0); 1749 // FIXME: What happens when these are dependent? Is this function even called? 1750 1751 if (IsDerivedFrom(ToClass, FromClass)) { 1752 ConvertedType = Context.getMemberPointerType(FromTypePtr->getPointeeType(), 1753 ToClass.getTypePtr()); 1754 return true; 1755 } 1756 1757 return false; 1758} 1759 1760/// CheckMemberPointerConversion - Check the member pointer conversion from the 1761/// expression From to the type ToType. This routine checks for ambiguous or 1762/// virtual or inaccessible base-to-derived member pointer conversions 1763/// for which IsMemberPointerConversion has already returned true. It returns 1764/// true and produces a diagnostic if there was an error, or returns false 1765/// otherwise. 1766bool Sema::CheckMemberPointerConversion(Expr *From, QualType ToType, 1767 CastExpr::CastKind &Kind, 1768 CXXCastPath &BasePath, 1769 bool IgnoreBaseAccess) { 1770 QualType FromType = From->getType(); 1771 const MemberPointerType *FromPtrType = FromType->getAs<MemberPointerType>(); 1772 if (!FromPtrType) { 1773 // This must be a null pointer to member pointer conversion 1774 assert(From->isNullPointerConstant(Context, 1775 Expr::NPC_ValueDependentIsNull) && 1776 "Expr must be null pointer constant!"); 1777 Kind = CastExpr::CK_NullToMemberPointer; 1778 return false; 1779 } 1780 1781 const MemberPointerType *ToPtrType = ToType->getAs<MemberPointerType>(); 1782 assert(ToPtrType && "No member pointer cast has a target type " 1783 "that is not a member pointer."); 1784 1785 QualType FromClass = QualType(FromPtrType->getClass(), 0); 1786 QualType ToClass = QualType(ToPtrType->getClass(), 0); 1787 1788 // FIXME: What about dependent types? 1789 assert(FromClass->isRecordType() && "Pointer into non-class."); 1790 assert(ToClass->isRecordType() && "Pointer into non-class."); 1791 1792 CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true, 1793 /*DetectVirtual=*/true); 1794 bool DerivationOkay = IsDerivedFrom(ToClass, FromClass, Paths); 1795 assert(DerivationOkay && 1796 "Should not have been called if derivation isn't OK."); 1797 (void)DerivationOkay; 1798 1799 if (Paths.isAmbiguous(Context.getCanonicalType(FromClass). 1800 getUnqualifiedType())) { 1801 std::string PathDisplayStr = getAmbiguousPathsDisplayString(Paths); 1802 Diag(From->getExprLoc(), diag::err_ambiguous_memptr_conv) 1803 << 0 << FromClass << ToClass << PathDisplayStr << From->getSourceRange(); 1804 return true; 1805 } 1806 1807 if (const RecordType *VBase = Paths.getDetectedVirtual()) { 1808 Diag(From->getExprLoc(), diag::err_memptr_conv_via_virtual) 1809 << FromClass << ToClass << QualType(VBase, 0) 1810 << From->getSourceRange(); 1811 return true; 1812 } 1813 1814 if (!IgnoreBaseAccess) 1815 CheckBaseClassAccess(From->getExprLoc(), FromClass, ToClass, 1816 Paths.front(), 1817 diag::err_downcast_from_inaccessible_base); 1818 1819 // Must be a base to derived member conversion. 1820 BuildBasePathArray(Paths, BasePath); 1821 Kind = CastExpr::CK_BaseToDerivedMemberPointer; 1822 return false; 1823} 1824 1825/// IsQualificationConversion - Determines whether the conversion from 1826/// an rvalue of type FromType to ToType is a qualification conversion 1827/// (C++ 4.4). 1828bool 1829Sema::IsQualificationConversion(QualType FromType, QualType ToType) { 1830 FromType = Context.getCanonicalType(FromType); 1831 ToType = Context.getCanonicalType(ToType); 1832 1833 // If FromType and ToType are the same type, this is not a 1834 // qualification conversion. 1835 if (FromType.getUnqualifiedType() == ToType.getUnqualifiedType()) 1836 return false; 1837 1838 // (C++ 4.4p4): 1839 // A conversion can add cv-qualifiers at levels other than the first 1840 // in multi-level pointers, subject to the following rules: [...] 1841 bool PreviousToQualsIncludeConst = true; 1842 bool UnwrappedAnyPointer = false; 1843 while (Context.UnwrapSimilarPointerTypes(FromType, ToType)) { 1844 // Within each iteration of the loop, we check the qualifiers to 1845 // determine if this still looks like a qualification 1846 // conversion. Then, if all is well, we unwrap one more level of 1847 // pointers or pointers-to-members and do it all again 1848 // until there are no more pointers or pointers-to-members left to 1849 // unwrap. 1850 UnwrappedAnyPointer = true; 1851 1852 // -- for every j > 0, if const is in cv 1,j then const is in cv 1853 // 2,j, and similarly for volatile. 1854 if (!ToType.isAtLeastAsQualifiedAs(FromType)) 1855 return false; 1856 1857 // -- if the cv 1,j and cv 2,j are different, then const is in 1858 // every cv for 0 < k < j. 1859 if (FromType.getCVRQualifiers() != ToType.getCVRQualifiers() 1860 && !PreviousToQualsIncludeConst) 1861 return false; 1862 1863 // Keep track of whether all prior cv-qualifiers in the "to" type 1864 // include const. 1865 PreviousToQualsIncludeConst 1866 = PreviousToQualsIncludeConst && ToType.isConstQualified(); 1867 } 1868 1869 // We are left with FromType and ToType being the pointee types 1870 // after unwrapping the original FromType and ToType the same number 1871 // of types. If we unwrapped any pointers, and if FromType and 1872 // ToType have the same unqualified type (since we checked 1873 // qualifiers above), then this is a qualification conversion. 1874 return UnwrappedAnyPointer && Context.hasSameUnqualifiedType(FromType,ToType); 1875} 1876 1877/// Determines whether there is a user-defined conversion sequence 1878/// (C++ [over.ics.user]) that converts expression From to the type 1879/// ToType. If such a conversion exists, User will contain the 1880/// user-defined conversion sequence that performs such a conversion 1881/// and this routine will return true. Otherwise, this routine returns 1882/// false and User is unspecified. 1883/// 1884/// \param AllowExplicit true if the conversion should consider C++0x 1885/// "explicit" conversion functions as well as non-explicit conversion 1886/// functions (C++0x [class.conv.fct]p2). 1887OverloadingResult Sema::IsUserDefinedConversion(Expr *From, QualType ToType, 1888 UserDefinedConversionSequence& User, 1889 OverloadCandidateSet& CandidateSet, 1890 bool AllowExplicit) { 1891 // Whether we will only visit constructors. 1892 bool ConstructorsOnly = false; 1893 1894 // If the type we are conversion to is a class type, enumerate its 1895 // constructors. 1896 if (const RecordType *ToRecordType = ToType->getAs<RecordType>()) { 1897 // C++ [over.match.ctor]p1: 1898 // When objects of class type are direct-initialized (8.5), or 1899 // copy-initialized from an expression of the same or a 1900 // derived class type (8.5), overload resolution selects the 1901 // constructor. [...] For copy-initialization, the candidate 1902 // functions are all the converting constructors (12.3.1) of 1903 // that class. The argument list is the expression-list within 1904 // the parentheses of the initializer. 1905 if (Context.hasSameUnqualifiedType(ToType, From->getType()) || 1906 (From->getType()->getAs<RecordType>() && 1907 IsDerivedFrom(From->getType(), ToType))) 1908 ConstructorsOnly = true; 1909 1910 if (RequireCompleteType(From->getLocStart(), ToType, PDiag())) { 1911 // We're not going to find any constructors. 1912 } else if (CXXRecordDecl *ToRecordDecl 1913 = dyn_cast<CXXRecordDecl>(ToRecordType->getDecl())) { 1914 DeclContext::lookup_iterator Con, ConEnd; 1915 for (llvm::tie(Con, ConEnd) = LookupConstructors(ToRecordDecl); 1916 Con != ConEnd; ++Con) { 1917 NamedDecl *D = *Con; 1918 DeclAccessPair FoundDecl = DeclAccessPair::make(D, D->getAccess()); 1919 1920 // Find the constructor (which may be a template). 1921 CXXConstructorDecl *Constructor = 0; 1922 FunctionTemplateDecl *ConstructorTmpl 1923 = dyn_cast<FunctionTemplateDecl>(D); 1924 if (ConstructorTmpl) 1925 Constructor 1926 = cast<CXXConstructorDecl>(ConstructorTmpl->getTemplatedDecl()); 1927 else 1928 Constructor = cast<CXXConstructorDecl>(D); 1929 1930 if (!Constructor->isInvalidDecl() && 1931 Constructor->isConvertingConstructor(AllowExplicit)) { 1932 if (ConstructorTmpl) 1933 AddTemplateOverloadCandidate(ConstructorTmpl, FoundDecl, 1934 /*ExplicitArgs*/ 0, 1935 &From, 1, CandidateSet, 1936 /*SuppressUserConversions=*/!ConstructorsOnly); 1937 else 1938 // Allow one user-defined conversion when user specifies a 1939 // From->ToType conversion via an static cast (c-style, etc). 1940 AddOverloadCandidate(Constructor, FoundDecl, 1941 &From, 1, CandidateSet, 1942 /*SuppressUserConversions=*/!ConstructorsOnly); 1943 } 1944 } 1945 } 1946 } 1947 1948 // Enumerate conversion functions, if we're allowed to. 1949 if (ConstructorsOnly) { 1950 } else if (RequireCompleteType(From->getLocStart(), From->getType(), 1951 PDiag(0) << From->getSourceRange())) { 1952 // No conversion functions from incomplete types. 1953 } else if (const RecordType *FromRecordType 1954 = From->getType()->getAs<RecordType>()) { 1955 if (CXXRecordDecl *FromRecordDecl 1956 = dyn_cast<CXXRecordDecl>(FromRecordType->getDecl())) { 1957 // Add all of the conversion functions as candidates. 1958 const UnresolvedSetImpl *Conversions 1959 = FromRecordDecl->getVisibleConversionFunctions(); 1960 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 1961 E = Conversions->end(); I != E; ++I) { 1962 DeclAccessPair FoundDecl = I.getPair(); 1963 NamedDecl *D = FoundDecl.getDecl(); 1964 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext()); 1965 if (isa<UsingShadowDecl>(D)) 1966 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 1967 1968 CXXConversionDecl *Conv; 1969 FunctionTemplateDecl *ConvTemplate; 1970 if ((ConvTemplate = dyn_cast<FunctionTemplateDecl>(D))) 1971 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 1972 else 1973 Conv = cast<CXXConversionDecl>(D); 1974 1975 if (AllowExplicit || !Conv->isExplicit()) { 1976 if (ConvTemplate) 1977 AddTemplateConversionCandidate(ConvTemplate, FoundDecl, 1978 ActingContext, From, ToType, 1979 CandidateSet); 1980 else 1981 AddConversionCandidate(Conv, FoundDecl, ActingContext, 1982 From, ToType, CandidateSet); 1983 } 1984 } 1985 } 1986 } 1987 1988 OverloadCandidateSet::iterator Best; 1989 switch (BestViableFunction(CandidateSet, From->getLocStart(), Best)) { 1990 case OR_Success: 1991 // Record the standard conversion we used and the conversion function. 1992 if (CXXConstructorDecl *Constructor 1993 = dyn_cast<CXXConstructorDecl>(Best->Function)) { 1994 // C++ [over.ics.user]p1: 1995 // If the user-defined conversion is specified by a 1996 // constructor (12.3.1), the initial standard conversion 1997 // sequence converts the source type to the type required by 1998 // the argument of the constructor. 1999 // 2000 QualType ThisType = Constructor->getThisType(Context); 2001 if (Best->Conversions[0].isEllipsis()) 2002 User.EllipsisConversion = true; 2003 else { 2004 User.Before = Best->Conversions[0].Standard; 2005 User.EllipsisConversion = false; 2006 } 2007 User.ConversionFunction = Constructor; 2008 User.After.setAsIdentityConversion(); 2009 User.After.setFromType( 2010 ThisType->getAs<PointerType>()->getPointeeType()); 2011 User.After.setAllToTypes(ToType); 2012 return OR_Success; 2013 } else if (CXXConversionDecl *Conversion 2014 = dyn_cast<CXXConversionDecl>(Best->Function)) { 2015 // C++ [over.ics.user]p1: 2016 // 2017 // [...] If the user-defined conversion is specified by a 2018 // conversion function (12.3.2), the initial standard 2019 // conversion sequence converts the source type to the 2020 // implicit object parameter of the conversion function. 2021 User.Before = Best->Conversions[0].Standard; 2022 User.ConversionFunction = Conversion; 2023 User.EllipsisConversion = false; 2024 2025 // C++ [over.ics.user]p2: 2026 // The second standard conversion sequence converts the 2027 // result of the user-defined conversion to the target type 2028 // for the sequence. Since an implicit conversion sequence 2029 // is an initialization, the special rules for 2030 // initialization by user-defined conversion apply when 2031 // selecting the best user-defined conversion for a 2032 // user-defined conversion sequence (see 13.3.3 and 2033 // 13.3.3.1). 2034 User.After = Best->FinalConversion; 2035 return OR_Success; 2036 } else { 2037 assert(false && "Not a constructor or conversion function?"); 2038 return OR_No_Viable_Function; 2039 } 2040 2041 case OR_No_Viable_Function: 2042 return OR_No_Viable_Function; 2043 case OR_Deleted: 2044 // No conversion here! We're done. 2045 return OR_Deleted; 2046 2047 case OR_Ambiguous: 2048 return OR_Ambiguous; 2049 } 2050 2051 return OR_No_Viable_Function; 2052} 2053 2054bool 2055Sema::DiagnoseMultipleUserDefinedConversion(Expr *From, QualType ToType) { 2056 ImplicitConversionSequence ICS; 2057 OverloadCandidateSet CandidateSet(From->getExprLoc()); 2058 OverloadingResult OvResult = 2059 IsUserDefinedConversion(From, ToType, ICS.UserDefined, 2060 CandidateSet, false); 2061 if (OvResult == OR_Ambiguous) 2062 Diag(From->getSourceRange().getBegin(), 2063 diag::err_typecheck_ambiguous_condition) 2064 << From->getType() << ToType << From->getSourceRange(); 2065 else if (OvResult == OR_No_Viable_Function && !CandidateSet.empty()) 2066 Diag(From->getSourceRange().getBegin(), 2067 diag::err_typecheck_nonviable_condition) 2068 << From->getType() << ToType << From->getSourceRange(); 2069 else 2070 return false; 2071 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, &From, 1); 2072 return true; 2073} 2074 2075/// CompareImplicitConversionSequences - Compare two implicit 2076/// conversion sequences to determine whether one is better than the 2077/// other or if they are indistinguishable (C++ 13.3.3.2). 2078ImplicitConversionSequence::CompareKind 2079Sema::CompareImplicitConversionSequences(const ImplicitConversionSequence& ICS1, 2080 const ImplicitConversionSequence& ICS2) 2081{ 2082 // (C++ 13.3.3.2p2): When comparing the basic forms of implicit 2083 // conversion sequences (as defined in 13.3.3.1) 2084 // -- a standard conversion sequence (13.3.3.1.1) is a better 2085 // conversion sequence than a user-defined conversion sequence or 2086 // an ellipsis conversion sequence, and 2087 // -- a user-defined conversion sequence (13.3.3.1.2) is a better 2088 // conversion sequence than an ellipsis conversion sequence 2089 // (13.3.3.1.3). 2090 // 2091 // C++0x [over.best.ics]p10: 2092 // For the purpose of ranking implicit conversion sequences as 2093 // described in 13.3.3.2, the ambiguous conversion sequence is 2094 // treated as a user-defined sequence that is indistinguishable 2095 // from any other user-defined conversion sequence. 2096 if (ICS1.getKindRank() < ICS2.getKindRank()) 2097 return ImplicitConversionSequence::Better; 2098 else if (ICS2.getKindRank() < ICS1.getKindRank()) 2099 return ImplicitConversionSequence::Worse; 2100 2101 // The following checks require both conversion sequences to be of 2102 // the same kind. 2103 if (ICS1.getKind() != ICS2.getKind()) 2104 return ImplicitConversionSequence::Indistinguishable; 2105 2106 // Two implicit conversion sequences of the same form are 2107 // indistinguishable conversion sequences unless one of the 2108 // following rules apply: (C++ 13.3.3.2p3): 2109 if (ICS1.isStandard()) 2110 return CompareStandardConversionSequences(ICS1.Standard, ICS2.Standard); 2111 else if (ICS1.isUserDefined()) { 2112 // User-defined conversion sequence U1 is a better conversion 2113 // sequence than another user-defined conversion sequence U2 if 2114 // they contain the same user-defined conversion function or 2115 // constructor and if the second standard conversion sequence of 2116 // U1 is better than the second standard conversion sequence of 2117 // U2 (C++ 13.3.3.2p3). 2118 if (ICS1.UserDefined.ConversionFunction == 2119 ICS2.UserDefined.ConversionFunction) 2120 return CompareStandardConversionSequences(ICS1.UserDefined.After, 2121 ICS2.UserDefined.After); 2122 } 2123 2124 return ImplicitConversionSequence::Indistinguishable; 2125} 2126 2127static bool hasSimilarType(ASTContext &Context, QualType T1, QualType T2) { 2128 while (Context.UnwrapSimilarPointerTypes(T1, T2)) { 2129 Qualifiers Quals; 2130 T1 = Context.getUnqualifiedArrayType(T1, Quals); 2131 T2 = Context.getUnqualifiedArrayType(T2, Quals); 2132 } 2133 2134 return Context.hasSameUnqualifiedType(T1, T2); 2135} 2136 2137// Per 13.3.3.2p3, compare the given standard conversion sequences to 2138// determine if one is a proper subset of the other. 2139static ImplicitConversionSequence::CompareKind 2140compareStandardConversionSubsets(ASTContext &Context, 2141 const StandardConversionSequence& SCS1, 2142 const StandardConversionSequence& SCS2) { 2143 ImplicitConversionSequence::CompareKind Result 2144 = ImplicitConversionSequence::Indistinguishable; 2145 2146 // the identity conversion sequence is considered to be a subsequence of 2147 // any non-identity conversion sequence 2148 if (SCS1.ReferenceBinding == SCS2.ReferenceBinding) { 2149 if (SCS1.isIdentityConversion() && !SCS2.isIdentityConversion()) 2150 return ImplicitConversionSequence::Better; 2151 else if (!SCS1.isIdentityConversion() && SCS2.isIdentityConversion()) 2152 return ImplicitConversionSequence::Worse; 2153 } 2154 2155 if (SCS1.Second != SCS2.Second) { 2156 if (SCS1.Second == ICK_Identity) 2157 Result = ImplicitConversionSequence::Better; 2158 else if (SCS2.Second == ICK_Identity) 2159 Result = ImplicitConversionSequence::Worse; 2160 else 2161 return ImplicitConversionSequence::Indistinguishable; 2162 } else if (!hasSimilarType(Context, SCS1.getToType(1), SCS2.getToType(1))) 2163 return ImplicitConversionSequence::Indistinguishable; 2164 2165 if (SCS1.Third == SCS2.Third) { 2166 return Context.hasSameType(SCS1.getToType(2), SCS2.getToType(2))? Result 2167 : ImplicitConversionSequence::Indistinguishable; 2168 } 2169 2170 if (SCS1.Third == ICK_Identity) 2171 return Result == ImplicitConversionSequence::Worse 2172 ? ImplicitConversionSequence::Indistinguishable 2173 : ImplicitConversionSequence::Better; 2174 2175 if (SCS2.Third == ICK_Identity) 2176 return Result == ImplicitConversionSequence::Better 2177 ? ImplicitConversionSequence::Indistinguishable 2178 : ImplicitConversionSequence::Worse; 2179 2180 return ImplicitConversionSequence::Indistinguishable; 2181} 2182 2183/// CompareStandardConversionSequences - Compare two standard 2184/// conversion sequences to determine whether one is better than the 2185/// other or if they are indistinguishable (C++ 13.3.3.2p3). 2186ImplicitConversionSequence::CompareKind 2187Sema::CompareStandardConversionSequences(const StandardConversionSequence& SCS1, 2188 const StandardConversionSequence& SCS2) 2189{ 2190 // Standard conversion sequence S1 is a better conversion sequence 2191 // than standard conversion sequence S2 if (C++ 13.3.3.2p3): 2192 2193 // -- S1 is a proper subsequence of S2 (comparing the conversion 2194 // sequences in the canonical form defined by 13.3.3.1.1, 2195 // excluding any Lvalue Transformation; the identity conversion 2196 // sequence is considered to be a subsequence of any 2197 // non-identity conversion sequence) or, if not that, 2198 if (ImplicitConversionSequence::CompareKind CK 2199 = compareStandardConversionSubsets(Context, SCS1, SCS2)) 2200 return CK; 2201 2202 // -- the rank of S1 is better than the rank of S2 (by the rules 2203 // defined below), or, if not that, 2204 ImplicitConversionRank Rank1 = SCS1.getRank(); 2205 ImplicitConversionRank Rank2 = SCS2.getRank(); 2206 if (Rank1 < Rank2) 2207 return ImplicitConversionSequence::Better; 2208 else if (Rank2 < Rank1) 2209 return ImplicitConversionSequence::Worse; 2210 2211 // (C++ 13.3.3.2p4): Two conversion sequences with the same rank 2212 // are indistinguishable unless one of the following rules 2213 // applies: 2214 2215 // A conversion that is not a conversion of a pointer, or 2216 // pointer to member, to bool is better than another conversion 2217 // that is such a conversion. 2218 if (SCS1.isPointerConversionToBool() != SCS2.isPointerConversionToBool()) 2219 return SCS2.isPointerConversionToBool() 2220 ? ImplicitConversionSequence::Better 2221 : ImplicitConversionSequence::Worse; 2222 2223 // C++ [over.ics.rank]p4b2: 2224 // 2225 // If class B is derived directly or indirectly from class A, 2226 // conversion of B* to A* is better than conversion of B* to 2227 // void*, and conversion of A* to void* is better than conversion 2228 // of B* to void*. 2229 bool SCS1ConvertsToVoid 2230 = SCS1.isPointerConversionToVoidPointer(Context); 2231 bool SCS2ConvertsToVoid 2232 = SCS2.isPointerConversionToVoidPointer(Context); 2233 if (SCS1ConvertsToVoid != SCS2ConvertsToVoid) { 2234 // Exactly one of the conversion sequences is a conversion to 2235 // a void pointer; it's the worse conversion. 2236 return SCS2ConvertsToVoid ? ImplicitConversionSequence::Better 2237 : ImplicitConversionSequence::Worse; 2238 } else if (!SCS1ConvertsToVoid && !SCS2ConvertsToVoid) { 2239 // Neither conversion sequence converts to a void pointer; compare 2240 // their derived-to-base conversions. 2241 if (ImplicitConversionSequence::CompareKind DerivedCK 2242 = CompareDerivedToBaseConversions(SCS1, SCS2)) 2243 return DerivedCK; 2244 } else if (SCS1ConvertsToVoid && SCS2ConvertsToVoid) { 2245 // Both conversion sequences are conversions to void 2246 // pointers. Compare the source types to determine if there's an 2247 // inheritance relationship in their sources. 2248 QualType FromType1 = SCS1.getFromType(); 2249 QualType FromType2 = SCS2.getFromType(); 2250 2251 // Adjust the types we're converting from via the array-to-pointer 2252 // conversion, if we need to. 2253 if (SCS1.First == ICK_Array_To_Pointer) 2254 FromType1 = Context.getArrayDecayedType(FromType1); 2255 if (SCS2.First == ICK_Array_To_Pointer) 2256 FromType2 = Context.getArrayDecayedType(FromType2); 2257 2258 QualType FromPointee1 2259 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2260 QualType FromPointee2 2261 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2262 2263 if (IsDerivedFrom(FromPointee2, FromPointee1)) 2264 return ImplicitConversionSequence::Better; 2265 else if (IsDerivedFrom(FromPointee1, FromPointee2)) 2266 return ImplicitConversionSequence::Worse; 2267 2268 // Objective-C++: If one interface is more specific than the 2269 // other, it is the better one. 2270 const ObjCObjectType* FromIface1 = FromPointee1->getAs<ObjCObjectType>(); 2271 const ObjCObjectType* FromIface2 = FromPointee2->getAs<ObjCObjectType>(); 2272 if (FromIface1 && FromIface1) { 2273 if (Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 2274 return ImplicitConversionSequence::Better; 2275 else if (Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 2276 return ImplicitConversionSequence::Worse; 2277 } 2278 } 2279 2280 // Compare based on qualification conversions (C++ 13.3.3.2p3, 2281 // bullet 3). 2282 if (ImplicitConversionSequence::CompareKind QualCK 2283 = CompareQualificationConversions(SCS1, SCS2)) 2284 return QualCK; 2285 2286 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding) { 2287 // C++0x [over.ics.rank]p3b4: 2288 // -- S1 and S2 are reference bindings (8.5.3) and neither refers to an 2289 // implicit object parameter of a non-static member function declared 2290 // without a ref-qualifier, and S1 binds an rvalue reference to an 2291 // rvalue and S2 binds an lvalue reference. 2292 // FIXME: We don't know if we're dealing with the implicit object parameter, 2293 // or if the member function in this case has a ref qualifier. 2294 // (Of course, we don't have ref qualifiers yet.) 2295 if (SCS1.RRefBinding != SCS2.RRefBinding) 2296 return SCS1.RRefBinding ? ImplicitConversionSequence::Better 2297 : ImplicitConversionSequence::Worse; 2298 2299 // C++ [over.ics.rank]p3b4: 2300 // -- S1 and S2 are reference bindings (8.5.3), and the types to 2301 // which the references refer are the same type except for 2302 // top-level cv-qualifiers, and the type to which the reference 2303 // initialized by S2 refers is more cv-qualified than the type 2304 // to which the reference initialized by S1 refers. 2305 QualType T1 = SCS1.getToType(2); 2306 QualType T2 = SCS2.getToType(2); 2307 T1 = Context.getCanonicalType(T1); 2308 T2 = Context.getCanonicalType(T2); 2309 Qualifiers T1Quals, T2Quals; 2310 QualType UnqualT1 = Context.getUnqualifiedArrayType(T1, T1Quals); 2311 QualType UnqualT2 = Context.getUnqualifiedArrayType(T2, T2Quals); 2312 if (UnqualT1 == UnqualT2) { 2313 // If the type is an array type, promote the element qualifiers to the type 2314 // for comparison. 2315 if (isa<ArrayType>(T1) && T1Quals) 2316 T1 = Context.getQualifiedType(UnqualT1, T1Quals); 2317 if (isa<ArrayType>(T2) && T2Quals) 2318 T2 = Context.getQualifiedType(UnqualT2, T2Quals); 2319 if (T2.isMoreQualifiedThan(T1)) 2320 return ImplicitConversionSequence::Better; 2321 else if (T1.isMoreQualifiedThan(T2)) 2322 return ImplicitConversionSequence::Worse; 2323 } 2324 } 2325 2326 return ImplicitConversionSequence::Indistinguishable; 2327} 2328 2329/// CompareQualificationConversions - Compares two standard conversion 2330/// sequences to determine whether they can be ranked based on their 2331/// qualification conversions (C++ 13.3.3.2p3 bullet 3). 2332ImplicitConversionSequence::CompareKind 2333Sema::CompareQualificationConversions(const StandardConversionSequence& SCS1, 2334 const StandardConversionSequence& SCS2) { 2335 // C++ 13.3.3.2p3: 2336 // -- S1 and S2 differ only in their qualification conversion and 2337 // yield similar types T1 and T2 (C++ 4.4), respectively, and the 2338 // cv-qualification signature of type T1 is a proper subset of 2339 // the cv-qualification signature of type T2, and S1 is not the 2340 // deprecated string literal array-to-pointer conversion (4.2). 2341 if (SCS1.First != SCS2.First || SCS1.Second != SCS2.Second || 2342 SCS1.Third != SCS2.Third || SCS1.Third != ICK_Qualification) 2343 return ImplicitConversionSequence::Indistinguishable; 2344 2345 // FIXME: the example in the standard doesn't use a qualification 2346 // conversion (!) 2347 QualType T1 = SCS1.getToType(2); 2348 QualType T2 = SCS2.getToType(2); 2349 T1 = Context.getCanonicalType(T1); 2350 T2 = Context.getCanonicalType(T2); 2351 Qualifiers T1Quals, T2Quals; 2352 QualType UnqualT1 = Context.getUnqualifiedArrayType(T1, T1Quals); 2353 QualType UnqualT2 = Context.getUnqualifiedArrayType(T2, T2Quals); 2354 2355 // If the types are the same, we won't learn anything by unwrapped 2356 // them. 2357 if (UnqualT1 == UnqualT2) 2358 return ImplicitConversionSequence::Indistinguishable; 2359 2360 // If the type is an array type, promote the element qualifiers to the type 2361 // for comparison. 2362 if (isa<ArrayType>(T1) && T1Quals) 2363 T1 = Context.getQualifiedType(UnqualT1, T1Quals); 2364 if (isa<ArrayType>(T2) && T2Quals) 2365 T2 = Context.getQualifiedType(UnqualT2, T2Quals); 2366 2367 ImplicitConversionSequence::CompareKind Result 2368 = ImplicitConversionSequence::Indistinguishable; 2369 while (Context.UnwrapSimilarPointerTypes(T1, T2)) { 2370 // Within each iteration of the loop, we check the qualifiers to 2371 // determine if this still looks like a qualification 2372 // conversion. Then, if all is well, we unwrap one more level of 2373 // pointers or pointers-to-members and do it all again 2374 // until there are no more pointers or pointers-to-members left 2375 // to unwrap. This essentially mimics what 2376 // IsQualificationConversion does, but here we're checking for a 2377 // strict subset of qualifiers. 2378 if (T1.getCVRQualifiers() == T2.getCVRQualifiers()) 2379 // The qualifiers are the same, so this doesn't tell us anything 2380 // about how the sequences rank. 2381 ; 2382 else if (T2.isMoreQualifiedThan(T1)) { 2383 // T1 has fewer qualifiers, so it could be the better sequence. 2384 if (Result == ImplicitConversionSequence::Worse) 2385 // Neither has qualifiers that are a subset of the other's 2386 // qualifiers. 2387 return ImplicitConversionSequence::Indistinguishable; 2388 2389 Result = ImplicitConversionSequence::Better; 2390 } else if (T1.isMoreQualifiedThan(T2)) { 2391 // T2 has fewer qualifiers, so it could be the better sequence. 2392 if (Result == ImplicitConversionSequence::Better) 2393 // Neither has qualifiers that are a subset of the other's 2394 // qualifiers. 2395 return ImplicitConversionSequence::Indistinguishable; 2396 2397 Result = ImplicitConversionSequence::Worse; 2398 } else { 2399 // Qualifiers are disjoint. 2400 return ImplicitConversionSequence::Indistinguishable; 2401 } 2402 2403 // If the types after this point are equivalent, we're done. 2404 if (Context.hasSameUnqualifiedType(T1, T2)) 2405 break; 2406 } 2407 2408 // Check that the winning standard conversion sequence isn't using 2409 // the deprecated string literal array to pointer conversion. 2410 switch (Result) { 2411 case ImplicitConversionSequence::Better: 2412 if (SCS1.DeprecatedStringLiteralToCharPtr) 2413 Result = ImplicitConversionSequence::Indistinguishable; 2414 break; 2415 2416 case ImplicitConversionSequence::Indistinguishable: 2417 break; 2418 2419 case ImplicitConversionSequence::Worse: 2420 if (SCS2.DeprecatedStringLiteralToCharPtr) 2421 Result = ImplicitConversionSequence::Indistinguishable; 2422 break; 2423 } 2424 2425 return Result; 2426} 2427 2428/// CompareDerivedToBaseConversions - Compares two standard conversion 2429/// sequences to determine whether they can be ranked based on their 2430/// various kinds of derived-to-base conversions (C++ 2431/// [over.ics.rank]p4b3). As part of these checks, we also look at 2432/// conversions between Objective-C interface types. 2433ImplicitConversionSequence::CompareKind 2434Sema::CompareDerivedToBaseConversions(const StandardConversionSequence& SCS1, 2435 const StandardConversionSequence& SCS2) { 2436 QualType FromType1 = SCS1.getFromType(); 2437 QualType ToType1 = SCS1.getToType(1); 2438 QualType FromType2 = SCS2.getFromType(); 2439 QualType ToType2 = SCS2.getToType(1); 2440 2441 // Adjust the types we're converting from via the array-to-pointer 2442 // conversion, if we need to. 2443 if (SCS1.First == ICK_Array_To_Pointer) 2444 FromType1 = Context.getArrayDecayedType(FromType1); 2445 if (SCS2.First == ICK_Array_To_Pointer) 2446 FromType2 = Context.getArrayDecayedType(FromType2); 2447 2448 // Canonicalize all of the types. 2449 FromType1 = Context.getCanonicalType(FromType1); 2450 ToType1 = Context.getCanonicalType(ToType1); 2451 FromType2 = Context.getCanonicalType(FromType2); 2452 ToType2 = Context.getCanonicalType(ToType2); 2453 2454 // C++ [over.ics.rank]p4b3: 2455 // 2456 // If class B is derived directly or indirectly from class A and 2457 // class C is derived directly or indirectly from B, 2458 // 2459 // For Objective-C, we let A, B, and C also be Objective-C 2460 // interfaces. 2461 2462 // Compare based on pointer conversions. 2463 if (SCS1.Second == ICK_Pointer_Conversion && 2464 SCS2.Second == ICK_Pointer_Conversion && 2465 /*FIXME: Remove if Objective-C id conversions get their own rank*/ 2466 FromType1->isPointerType() && FromType2->isPointerType() && 2467 ToType1->isPointerType() && ToType2->isPointerType()) { 2468 QualType FromPointee1 2469 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2470 QualType ToPointee1 2471 = ToType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2472 QualType FromPointee2 2473 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2474 QualType ToPointee2 2475 = ToType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2476 2477 const ObjCObjectType* FromIface1 = FromPointee1->getAs<ObjCObjectType>(); 2478 const ObjCObjectType* FromIface2 = FromPointee2->getAs<ObjCObjectType>(); 2479 const ObjCObjectType* ToIface1 = ToPointee1->getAs<ObjCObjectType>(); 2480 const ObjCObjectType* ToIface2 = ToPointee2->getAs<ObjCObjectType>(); 2481 2482 // -- conversion of C* to B* is better than conversion of C* to A*, 2483 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 2484 if (IsDerivedFrom(ToPointee1, ToPointee2)) 2485 return ImplicitConversionSequence::Better; 2486 else if (IsDerivedFrom(ToPointee2, ToPointee1)) 2487 return ImplicitConversionSequence::Worse; 2488 2489 if (ToIface1 && ToIface2) { 2490 if (Context.canAssignObjCInterfaces(ToIface2, ToIface1)) 2491 return ImplicitConversionSequence::Better; 2492 else if (Context.canAssignObjCInterfaces(ToIface1, ToIface2)) 2493 return ImplicitConversionSequence::Worse; 2494 } 2495 } 2496 2497 // -- conversion of B* to A* is better than conversion of C* to A*, 2498 if (FromPointee1 != FromPointee2 && ToPointee1 == ToPointee2) { 2499 if (IsDerivedFrom(FromPointee2, FromPointee1)) 2500 return ImplicitConversionSequence::Better; 2501 else if (IsDerivedFrom(FromPointee1, FromPointee2)) 2502 return ImplicitConversionSequence::Worse; 2503 2504 if (FromIface1 && FromIface2) { 2505 if (Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 2506 return ImplicitConversionSequence::Better; 2507 else if (Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 2508 return ImplicitConversionSequence::Worse; 2509 } 2510 } 2511 } 2512 2513 // Ranking of member-pointer types. 2514 if (SCS1.Second == ICK_Pointer_Member && SCS2.Second == ICK_Pointer_Member && 2515 FromType1->isMemberPointerType() && FromType2->isMemberPointerType() && 2516 ToType1->isMemberPointerType() && ToType2->isMemberPointerType()) { 2517 const MemberPointerType * FromMemPointer1 = 2518 FromType1->getAs<MemberPointerType>(); 2519 const MemberPointerType * ToMemPointer1 = 2520 ToType1->getAs<MemberPointerType>(); 2521 const MemberPointerType * FromMemPointer2 = 2522 FromType2->getAs<MemberPointerType>(); 2523 const MemberPointerType * ToMemPointer2 = 2524 ToType2->getAs<MemberPointerType>(); 2525 const Type *FromPointeeType1 = FromMemPointer1->getClass(); 2526 const Type *ToPointeeType1 = ToMemPointer1->getClass(); 2527 const Type *FromPointeeType2 = FromMemPointer2->getClass(); 2528 const Type *ToPointeeType2 = ToMemPointer2->getClass(); 2529 QualType FromPointee1 = QualType(FromPointeeType1, 0).getUnqualifiedType(); 2530 QualType ToPointee1 = QualType(ToPointeeType1, 0).getUnqualifiedType(); 2531 QualType FromPointee2 = QualType(FromPointeeType2, 0).getUnqualifiedType(); 2532 QualType ToPointee2 = QualType(ToPointeeType2, 0).getUnqualifiedType(); 2533 // conversion of A::* to B::* is better than conversion of A::* to C::*, 2534 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 2535 if (IsDerivedFrom(ToPointee1, ToPointee2)) 2536 return ImplicitConversionSequence::Worse; 2537 else if (IsDerivedFrom(ToPointee2, ToPointee1)) 2538 return ImplicitConversionSequence::Better; 2539 } 2540 // conversion of B::* to C::* is better than conversion of A::* to C::* 2541 if (ToPointee1 == ToPointee2 && FromPointee1 != FromPointee2) { 2542 if (IsDerivedFrom(FromPointee1, FromPointee2)) 2543 return ImplicitConversionSequence::Better; 2544 else if (IsDerivedFrom(FromPointee2, FromPointee1)) 2545 return ImplicitConversionSequence::Worse; 2546 } 2547 } 2548 2549 if (SCS1.Second == ICK_Derived_To_Base) { 2550 // -- conversion of C to B is better than conversion of C to A, 2551 // -- binding of an expression of type C to a reference of type 2552 // B& is better than binding an expression of type C to a 2553 // reference of type A&, 2554 if (Context.hasSameUnqualifiedType(FromType1, FromType2) && 2555 !Context.hasSameUnqualifiedType(ToType1, ToType2)) { 2556 if (IsDerivedFrom(ToType1, ToType2)) 2557 return ImplicitConversionSequence::Better; 2558 else if (IsDerivedFrom(ToType2, ToType1)) 2559 return ImplicitConversionSequence::Worse; 2560 } 2561 2562 // -- conversion of B to A is better than conversion of C to A. 2563 // -- binding of an expression of type B to a reference of type 2564 // A& is better than binding an expression of type C to a 2565 // reference of type A&, 2566 if (!Context.hasSameUnqualifiedType(FromType1, FromType2) && 2567 Context.hasSameUnqualifiedType(ToType1, ToType2)) { 2568 if (IsDerivedFrom(FromType2, FromType1)) 2569 return ImplicitConversionSequence::Better; 2570 else if (IsDerivedFrom(FromType1, FromType2)) 2571 return ImplicitConversionSequence::Worse; 2572 } 2573 } 2574 2575 return ImplicitConversionSequence::Indistinguishable; 2576} 2577 2578/// CompareReferenceRelationship - Compare the two types T1 and T2 to 2579/// determine whether they are reference-related, 2580/// reference-compatible, reference-compatible with added 2581/// qualification, or incompatible, for use in C++ initialization by 2582/// reference (C++ [dcl.ref.init]p4). Neither type can be a reference 2583/// type, and the first type (T1) is the pointee type of the reference 2584/// type being initialized. 2585Sema::ReferenceCompareResult 2586Sema::CompareReferenceRelationship(SourceLocation Loc, 2587 QualType OrigT1, QualType OrigT2, 2588 bool &DerivedToBase, 2589 bool &ObjCConversion) { 2590 assert(!OrigT1->isReferenceType() && 2591 "T1 must be the pointee type of the reference type"); 2592 assert(!OrigT2->isReferenceType() && "T2 cannot be a reference type"); 2593 2594 QualType T1 = Context.getCanonicalType(OrigT1); 2595 QualType T2 = Context.getCanonicalType(OrigT2); 2596 Qualifiers T1Quals, T2Quals; 2597 QualType UnqualT1 = Context.getUnqualifiedArrayType(T1, T1Quals); 2598 QualType UnqualT2 = Context.getUnqualifiedArrayType(T2, T2Quals); 2599 2600 // C++ [dcl.init.ref]p4: 2601 // Given types "cv1 T1" and "cv2 T2," "cv1 T1" is 2602 // reference-related to "cv2 T2" if T1 is the same type as T2, or 2603 // T1 is a base class of T2. 2604 DerivedToBase = false; 2605 ObjCConversion = false; 2606 if (UnqualT1 == UnqualT2) { 2607 // Nothing to do. 2608 } else if (!RequireCompleteType(Loc, OrigT2, PDiag()) && 2609 IsDerivedFrom(UnqualT2, UnqualT1)) 2610 DerivedToBase = true; 2611 else if (UnqualT1->isObjCObjectOrInterfaceType() && 2612 UnqualT2->isObjCObjectOrInterfaceType() && 2613 Context.canBindObjCObjectType(UnqualT1, UnqualT2)) 2614 ObjCConversion = true; 2615 else 2616 return Ref_Incompatible; 2617 2618 // At this point, we know that T1 and T2 are reference-related (at 2619 // least). 2620 2621 // If the type is an array type, promote the element qualifiers to the type 2622 // for comparison. 2623 if (isa<ArrayType>(T1) && T1Quals) 2624 T1 = Context.getQualifiedType(UnqualT1, T1Quals); 2625 if (isa<ArrayType>(T2) && T2Quals) 2626 T2 = Context.getQualifiedType(UnqualT2, T2Quals); 2627 2628 // C++ [dcl.init.ref]p4: 2629 // "cv1 T1" is reference-compatible with "cv2 T2" if T1 is 2630 // reference-related to T2 and cv1 is the same cv-qualification 2631 // as, or greater cv-qualification than, cv2. For purposes of 2632 // overload resolution, cases for which cv1 is greater 2633 // cv-qualification than cv2 are identified as 2634 // reference-compatible with added qualification (see 13.3.3.2). 2635 if (T1Quals.getCVRQualifiers() == T2Quals.getCVRQualifiers()) 2636 return Ref_Compatible; 2637 else if (T1.isMoreQualifiedThan(T2)) 2638 return Ref_Compatible_With_Added_Qualification; 2639 else 2640 return Ref_Related; 2641} 2642 2643/// \brief Look for a user-defined conversion to an value reference-compatible 2644/// with DeclType. Return true if something definite is found. 2645static bool 2646FindConversionForRefInit(Sema &S, ImplicitConversionSequence &ICS, 2647 QualType DeclType, SourceLocation DeclLoc, 2648 Expr *Init, QualType T2, bool AllowRvalues, 2649 bool AllowExplicit) { 2650 assert(T2->isRecordType() && "Can only find conversions of record types."); 2651 CXXRecordDecl *T2RecordDecl 2652 = dyn_cast<CXXRecordDecl>(T2->getAs<RecordType>()->getDecl()); 2653 2654 QualType ToType 2655 = AllowRvalues? DeclType->getAs<ReferenceType>()->getPointeeType() 2656 : DeclType; 2657 2658 OverloadCandidateSet CandidateSet(DeclLoc); 2659 const UnresolvedSetImpl *Conversions 2660 = T2RecordDecl->getVisibleConversionFunctions(); 2661 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 2662 E = Conversions->end(); I != E; ++I) { 2663 NamedDecl *D = *I; 2664 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(D->getDeclContext()); 2665 if (isa<UsingShadowDecl>(D)) 2666 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 2667 2668 FunctionTemplateDecl *ConvTemplate 2669 = dyn_cast<FunctionTemplateDecl>(D); 2670 CXXConversionDecl *Conv; 2671 if (ConvTemplate) 2672 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 2673 else 2674 Conv = cast<CXXConversionDecl>(D); 2675 2676 // If this is an explicit conversion, and we're not allowed to consider 2677 // explicit conversions, skip it. 2678 if (!AllowExplicit && Conv->isExplicit()) 2679 continue; 2680 2681 if (AllowRvalues) { 2682 bool DerivedToBase = false; 2683 bool ObjCConversion = false; 2684 if (!ConvTemplate && 2685 S.CompareReferenceRelationship(DeclLoc, 2686 Conv->getConversionType().getNonReferenceType().getUnqualifiedType(), 2687 DeclType.getNonReferenceType().getUnqualifiedType(), 2688 DerivedToBase, ObjCConversion) 2689 == Sema::Ref_Incompatible) 2690 continue; 2691 } else { 2692 // If the conversion function doesn't return a reference type, 2693 // it can't be considered for this conversion. An rvalue reference 2694 // is only acceptable if its referencee is a function type. 2695 2696 const ReferenceType *RefType = 2697 Conv->getConversionType()->getAs<ReferenceType>(); 2698 if (!RefType || 2699 (!RefType->isLValueReferenceType() && 2700 !RefType->getPointeeType()->isFunctionType())) 2701 continue; 2702 } 2703 2704 if (ConvTemplate) 2705 S.AddTemplateConversionCandidate(ConvTemplate, I.getPair(), ActingDC, 2706 Init, ToType, CandidateSet); 2707 else 2708 S.AddConversionCandidate(Conv, I.getPair(), ActingDC, Init, 2709 ToType, CandidateSet); 2710 } 2711 2712 OverloadCandidateSet::iterator Best; 2713 switch (S.BestViableFunction(CandidateSet, DeclLoc, Best)) { 2714 case OR_Success: 2715 // C++ [over.ics.ref]p1: 2716 // 2717 // [...] If the parameter binds directly to the result of 2718 // applying a conversion function to the argument 2719 // expression, the implicit conversion sequence is a 2720 // user-defined conversion sequence (13.3.3.1.2), with the 2721 // second standard conversion sequence either an identity 2722 // conversion or, if the conversion function returns an 2723 // entity of a type that is a derived class of the parameter 2724 // type, a derived-to-base Conversion. 2725 if (!Best->FinalConversion.DirectBinding) 2726 return false; 2727 2728 ICS.setUserDefined(); 2729 ICS.UserDefined.Before = Best->Conversions[0].Standard; 2730 ICS.UserDefined.After = Best->FinalConversion; 2731 ICS.UserDefined.ConversionFunction = Best->Function; 2732 ICS.UserDefined.EllipsisConversion = false; 2733 assert(ICS.UserDefined.After.ReferenceBinding && 2734 ICS.UserDefined.After.DirectBinding && 2735 "Expected a direct reference binding!"); 2736 return true; 2737 2738 case OR_Ambiguous: 2739 ICS.setAmbiguous(); 2740 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 2741 Cand != CandidateSet.end(); ++Cand) 2742 if (Cand->Viable) 2743 ICS.Ambiguous.addConversion(Cand->Function); 2744 return true; 2745 2746 case OR_No_Viable_Function: 2747 case OR_Deleted: 2748 // There was no suitable conversion, or we found a deleted 2749 // conversion; continue with other checks. 2750 return false; 2751 } 2752 2753 return false; 2754} 2755 2756/// \brief Compute an implicit conversion sequence for reference 2757/// initialization. 2758static ImplicitConversionSequence 2759TryReferenceInit(Sema &S, Expr *&Init, QualType DeclType, 2760 SourceLocation DeclLoc, 2761 bool SuppressUserConversions, 2762 bool AllowExplicit) { 2763 assert(DeclType->isReferenceType() && "Reference init needs a reference"); 2764 2765 // Most paths end in a failed conversion. 2766 ImplicitConversionSequence ICS; 2767 ICS.setBad(BadConversionSequence::no_conversion, Init, DeclType); 2768 2769 QualType T1 = DeclType->getAs<ReferenceType>()->getPointeeType(); 2770 QualType T2 = Init->getType(); 2771 2772 // If the initializer is the address of an overloaded function, try 2773 // to resolve the overloaded function. If all goes well, T2 is the 2774 // type of the resulting function. 2775 if (S.Context.getCanonicalType(T2) == S.Context.OverloadTy) { 2776 DeclAccessPair Found; 2777 if (FunctionDecl *Fn = S.ResolveAddressOfOverloadedFunction(Init, DeclType, 2778 false, Found)) 2779 T2 = Fn->getType(); 2780 } 2781 2782 // Compute some basic properties of the types and the initializer. 2783 bool isRValRef = DeclType->isRValueReferenceType(); 2784 bool DerivedToBase = false; 2785 bool ObjCConversion = false; 2786 Expr::Classification InitCategory = Init->Classify(S.Context); 2787 Sema::ReferenceCompareResult RefRelationship 2788 = S.CompareReferenceRelationship(DeclLoc, T1, T2, DerivedToBase, 2789 ObjCConversion); 2790 2791 2792 // C++0x [dcl.init.ref]p5: 2793 // A reference to type "cv1 T1" is initialized by an expression 2794 // of type "cv2 T2" as follows: 2795 2796 // -- If reference is an lvalue reference and the initializer expression 2797 // The next bullet point (T1 is a function) is pretty much equivalent to this 2798 // one, so it's handled here. 2799 if (!isRValRef || T1->isFunctionType()) { 2800 // -- is an lvalue (but is not a bit-field), and "cv1 T1" is 2801 // reference-compatible with "cv2 T2," or 2802 // 2803 // Per C++ [over.ics.ref]p4, we don't check the bit-field property here. 2804 if (InitCategory.isLValue() && 2805 RefRelationship >= Sema::Ref_Compatible_With_Added_Qualification) { 2806 // C++ [over.ics.ref]p1: 2807 // When a parameter of reference type binds directly (8.5.3) 2808 // to an argument expression, the implicit conversion sequence 2809 // is the identity conversion, unless the argument expression 2810 // has a type that is a derived class of the parameter type, 2811 // in which case the implicit conversion sequence is a 2812 // derived-to-base Conversion (13.3.3.1). 2813 ICS.setStandard(); 2814 ICS.Standard.First = ICK_Identity; 2815 ICS.Standard.Second = DerivedToBase? ICK_Derived_To_Base 2816 : ObjCConversion? ICK_Compatible_Conversion 2817 : ICK_Identity; 2818 ICS.Standard.Third = ICK_Identity; 2819 ICS.Standard.FromTypePtr = T2.getAsOpaquePtr(); 2820 ICS.Standard.setToType(0, T2); 2821 ICS.Standard.setToType(1, T1); 2822 ICS.Standard.setToType(2, T1); 2823 ICS.Standard.ReferenceBinding = true; 2824 ICS.Standard.DirectBinding = true; 2825 ICS.Standard.RRefBinding = isRValRef; 2826 ICS.Standard.CopyConstructor = 0; 2827 2828 // Nothing more to do: the inaccessibility/ambiguity check for 2829 // derived-to-base conversions is suppressed when we're 2830 // computing the implicit conversion sequence (C++ 2831 // [over.best.ics]p2). 2832 return ICS; 2833 } 2834 2835 // -- has a class type (i.e., T2 is a class type), where T1 is 2836 // not reference-related to T2, and can be implicitly 2837 // converted to an lvalue of type "cv3 T3," where "cv1 T1" 2838 // is reference-compatible with "cv3 T3" 92) (this 2839 // conversion is selected by enumerating the applicable 2840 // conversion functions (13.3.1.6) and choosing the best 2841 // one through overload resolution (13.3)), 2842 if (!SuppressUserConversions && T2->isRecordType() && 2843 !S.RequireCompleteType(DeclLoc, T2, 0) && 2844 RefRelationship == Sema::Ref_Incompatible) { 2845 if (FindConversionForRefInit(S, ICS, DeclType, DeclLoc, 2846 Init, T2, /*AllowRvalues=*/false, 2847 AllowExplicit)) 2848 return ICS; 2849 } 2850 } 2851 2852 // -- Otherwise, the reference shall be an lvalue reference to a 2853 // non-volatile const type (i.e., cv1 shall be const), or the reference 2854 // shall be an rvalue reference and the initializer expression shall be 2855 // an rvalue or have a function type. 2856 // 2857 // We actually handle one oddity of C++ [over.ics.ref] at this 2858 // point, which is that, due to p2 (which short-circuits reference 2859 // binding by only attempting a simple conversion for non-direct 2860 // bindings) and p3's strange wording, we allow a const volatile 2861 // reference to bind to an rvalue. Hence the check for the presence 2862 // of "const" rather than checking for "const" being the only 2863 // qualifier. 2864 // This is also the point where rvalue references and lvalue inits no longer 2865 // go together. 2866 if ((!isRValRef && !T1.isConstQualified()) || 2867 (isRValRef && InitCategory.isLValue())) 2868 return ICS; 2869 2870 // -- If T1 is a function type, then 2871 // -- if T2 is the same type as T1, the reference is bound to the 2872 // initializer expression lvalue; 2873 // -- if T2 is a class type and the initializer expression can be 2874 // implicitly converted to an lvalue of type T1 [...], the 2875 // reference is bound to the function lvalue that is the result 2876 // of the conversion; 2877 // This is the same as for the lvalue case above, so it was handled there. 2878 // -- otherwise, the program is ill-formed. 2879 // This is the one difference to the lvalue case. 2880 if (T1->isFunctionType()) 2881 return ICS; 2882 2883 // -- Otherwise, if T2 is a class type and 2884 // -- the initializer expression is an rvalue and "cv1 T1" 2885 // is reference-compatible with "cv2 T2," or 2886 // 2887 // -- T1 is not reference-related to T2 and the initializer 2888 // expression can be implicitly converted to an rvalue 2889 // of type "cv3 T3" (this conversion is selected by 2890 // enumerating the applicable conversion functions 2891 // (13.3.1.6) and choosing the best one through overload 2892 // resolution (13.3)), 2893 // 2894 // then the reference is bound to the initializer 2895 // expression rvalue in the first case and to the object 2896 // that is the result of the conversion in the second case 2897 // (or, in either case, to the appropriate base class 2898 // subobject of the object). 2899 if (T2->isRecordType()) { 2900 // First case: "cv1 T1" is reference-compatible with "cv2 T2". This is a 2901 // direct binding in C++0x but not in C++03. 2902 if (InitCategory.isRValue() && 2903 RefRelationship >= Sema::Ref_Compatible_With_Added_Qualification) { 2904 ICS.setStandard(); 2905 ICS.Standard.First = ICK_Identity; 2906 ICS.Standard.Second = DerivedToBase? ICK_Derived_To_Base 2907 : ObjCConversion? ICK_Compatible_Conversion 2908 : ICK_Identity; 2909 ICS.Standard.Third = ICK_Identity; 2910 ICS.Standard.FromTypePtr = T2.getAsOpaquePtr(); 2911 ICS.Standard.setToType(0, T2); 2912 ICS.Standard.setToType(1, T1); 2913 ICS.Standard.setToType(2, T1); 2914 ICS.Standard.ReferenceBinding = true; 2915 ICS.Standard.DirectBinding = S.getLangOptions().CPlusPlus0x; 2916 ICS.Standard.RRefBinding = isRValRef; 2917 ICS.Standard.CopyConstructor = 0; 2918 return ICS; 2919 } 2920 2921 // Second case: not reference-related. 2922 if (RefRelationship == Sema::Ref_Incompatible && 2923 !S.RequireCompleteType(DeclLoc, T2, 0) && 2924 FindConversionForRefInit(S, ICS, DeclType, DeclLoc, 2925 Init, T2, /*AllowRvalues=*/true, 2926 AllowExplicit)) 2927 return ICS; 2928 } 2929 2930 // -- Otherwise, a temporary of type "cv1 T1" is created and 2931 // initialized from the initializer expression using the 2932 // rules for a non-reference copy initialization (8.5). The 2933 // reference is then bound to the temporary. If T1 is 2934 // reference-related to T2, cv1 must be the same 2935 // cv-qualification as, or greater cv-qualification than, 2936 // cv2; otherwise, the program is ill-formed. 2937 if (RefRelationship == Sema::Ref_Related) { 2938 // If cv1 == cv2 or cv1 is a greater cv-qualified than cv2, then 2939 // we would be reference-compatible or reference-compatible with 2940 // added qualification. But that wasn't the case, so the reference 2941 // initialization fails. 2942 return ICS; 2943 } 2944 2945 // If at least one of the types is a class type, the types are not 2946 // related, and we aren't allowed any user conversions, the 2947 // reference binding fails. This case is important for breaking 2948 // recursion, since TryImplicitConversion below will attempt to 2949 // create a temporary through the use of a copy constructor. 2950 if (SuppressUserConversions && RefRelationship == Sema::Ref_Incompatible && 2951 (T1->isRecordType() || T2->isRecordType())) 2952 return ICS; 2953 2954 // C++ [over.ics.ref]p2: 2955 // When a parameter of reference type is not bound directly to 2956 // an argument expression, the conversion sequence is the one 2957 // required to convert the argument expression to the 2958 // underlying type of the reference according to 2959 // 13.3.3.1. Conceptually, this conversion sequence corresponds 2960 // to copy-initializing a temporary of the underlying type with 2961 // the argument expression. Any difference in top-level 2962 // cv-qualification is subsumed by the initialization itself 2963 // and does not constitute a conversion. 2964 ICS = S.TryImplicitConversion(Init, T1, SuppressUserConversions, 2965 /*AllowExplicit=*/false, 2966 /*InOverloadResolution=*/false); 2967 2968 // Of course, that's still a reference binding. 2969 if (ICS.isStandard()) { 2970 ICS.Standard.ReferenceBinding = true; 2971 ICS.Standard.RRefBinding = isRValRef; 2972 } else if (ICS.isUserDefined()) { 2973 ICS.UserDefined.After.ReferenceBinding = true; 2974 ICS.UserDefined.After.RRefBinding = isRValRef; 2975 } 2976 return ICS; 2977} 2978 2979/// TryCopyInitialization - Try to copy-initialize a value of type 2980/// ToType from the expression From. Return the implicit conversion 2981/// sequence required to pass this argument, which may be a bad 2982/// conversion sequence (meaning that the argument cannot be passed to 2983/// a parameter of this type). If @p SuppressUserConversions, then we 2984/// do not permit any user-defined conversion sequences. 2985static ImplicitConversionSequence 2986TryCopyInitialization(Sema &S, Expr *From, QualType ToType, 2987 bool SuppressUserConversions, 2988 bool InOverloadResolution) { 2989 if (ToType->isReferenceType()) 2990 return TryReferenceInit(S, From, ToType, 2991 /*FIXME:*/From->getLocStart(), 2992 SuppressUserConversions, 2993 /*AllowExplicit=*/false); 2994 2995 return S.TryImplicitConversion(From, ToType, 2996 SuppressUserConversions, 2997 /*AllowExplicit=*/false, 2998 InOverloadResolution); 2999} 3000 3001/// TryObjectArgumentInitialization - Try to initialize the object 3002/// parameter of the given member function (@c Method) from the 3003/// expression @p From. 3004ImplicitConversionSequence 3005Sema::TryObjectArgumentInitialization(QualType OrigFromType, 3006 CXXMethodDecl *Method, 3007 CXXRecordDecl *ActingContext) { 3008 QualType ClassType = Context.getTypeDeclType(ActingContext); 3009 // [class.dtor]p2: A destructor can be invoked for a const, volatile or 3010 // const volatile object. 3011 unsigned Quals = isa<CXXDestructorDecl>(Method) ? 3012 Qualifiers::Const | Qualifiers::Volatile : Method->getTypeQualifiers(); 3013 QualType ImplicitParamType = Context.getCVRQualifiedType(ClassType, Quals); 3014 3015 // Set up the conversion sequence as a "bad" conversion, to allow us 3016 // to exit early. 3017 ImplicitConversionSequence ICS; 3018 3019 // We need to have an object of class type. 3020 QualType FromType = OrigFromType; 3021 if (const PointerType *PT = FromType->getAs<PointerType>()) 3022 FromType = PT->getPointeeType(); 3023 3024 assert(FromType->isRecordType()); 3025 3026 // The implicit object parameter is has the type "reference to cv X", 3027 // where X is the class of which the function is a member 3028 // (C++ [over.match.funcs]p4). However, when finding an implicit 3029 // conversion sequence for the argument, we are not allowed to 3030 // create temporaries or perform user-defined conversions 3031 // (C++ [over.match.funcs]p5). We perform a simplified version of 3032 // reference binding here, that allows class rvalues to bind to 3033 // non-constant references. 3034 3035 // First check the qualifiers. We don't care about lvalue-vs-rvalue 3036 // with the implicit object parameter (C++ [over.match.funcs]p5). 3037 QualType FromTypeCanon = Context.getCanonicalType(FromType); 3038 if (ImplicitParamType.getCVRQualifiers() 3039 != FromTypeCanon.getLocalCVRQualifiers() && 3040 !ImplicitParamType.isAtLeastAsQualifiedAs(FromTypeCanon)) { 3041 ICS.setBad(BadConversionSequence::bad_qualifiers, 3042 OrigFromType, ImplicitParamType); 3043 return ICS; 3044 } 3045 3046 // Check that we have either the same type or a derived type. It 3047 // affects the conversion rank. 3048 QualType ClassTypeCanon = Context.getCanonicalType(ClassType); 3049 ImplicitConversionKind SecondKind; 3050 if (ClassTypeCanon == FromTypeCanon.getLocalUnqualifiedType()) { 3051 SecondKind = ICK_Identity; 3052 } else if (IsDerivedFrom(FromType, ClassType)) 3053 SecondKind = ICK_Derived_To_Base; 3054 else { 3055 ICS.setBad(BadConversionSequence::unrelated_class, 3056 FromType, ImplicitParamType); 3057 return ICS; 3058 } 3059 3060 // Success. Mark this as a reference binding. 3061 ICS.setStandard(); 3062 ICS.Standard.setAsIdentityConversion(); 3063 ICS.Standard.Second = SecondKind; 3064 ICS.Standard.setFromType(FromType); 3065 ICS.Standard.setAllToTypes(ImplicitParamType); 3066 ICS.Standard.ReferenceBinding = true; 3067 ICS.Standard.DirectBinding = true; 3068 ICS.Standard.RRefBinding = false; 3069 return ICS; 3070} 3071 3072/// PerformObjectArgumentInitialization - Perform initialization of 3073/// the implicit object parameter for the given Method with the given 3074/// expression. 3075bool 3076Sema::PerformObjectArgumentInitialization(Expr *&From, 3077 NestedNameSpecifier *Qualifier, 3078 NamedDecl *FoundDecl, 3079 CXXMethodDecl *Method) { 3080 QualType FromRecordType, DestType; 3081 QualType ImplicitParamRecordType = 3082 Method->getThisType(Context)->getAs<PointerType>()->getPointeeType(); 3083 3084 if (const PointerType *PT = From->getType()->getAs<PointerType>()) { 3085 FromRecordType = PT->getPointeeType(); 3086 DestType = Method->getThisType(Context); 3087 } else { 3088 FromRecordType = From->getType(); 3089 DestType = ImplicitParamRecordType; 3090 } 3091 3092 // Note that we always use the true parent context when performing 3093 // the actual argument initialization. 3094 ImplicitConversionSequence ICS 3095 = TryObjectArgumentInitialization(From->getType(), Method, 3096 Method->getParent()); 3097 if (ICS.isBad()) 3098 return Diag(From->getSourceRange().getBegin(), 3099 diag::err_implicit_object_parameter_init) 3100 << ImplicitParamRecordType << FromRecordType << From->getSourceRange(); 3101 3102 if (ICS.Standard.Second == ICK_Derived_To_Base) 3103 return PerformObjectMemberConversion(From, Qualifier, FoundDecl, Method); 3104 3105 if (!Context.hasSameType(From->getType(), DestType)) 3106 ImpCastExprToType(From, DestType, CastExpr::CK_NoOp, 3107 From->getType()->isPointerType() ? 3108 ImplicitCastExpr::RValue : ImplicitCastExpr::LValue); 3109 return false; 3110} 3111 3112/// TryContextuallyConvertToBool - Attempt to contextually convert the 3113/// expression From to bool (C++0x [conv]p3). 3114ImplicitConversionSequence Sema::TryContextuallyConvertToBool(Expr *From) { 3115 // FIXME: This is pretty broken. 3116 return TryImplicitConversion(From, Context.BoolTy, 3117 // FIXME: Are these flags correct? 3118 /*SuppressUserConversions=*/false, 3119 /*AllowExplicit=*/true, 3120 /*InOverloadResolution=*/false); 3121} 3122 3123/// PerformContextuallyConvertToBool - Perform a contextual conversion 3124/// of the expression From to bool (C++0x [conv]p3). 3125bool Sema::PerformContextuallyConvertToBool(Expr *&From) { 3126 ImplicitConversionSequence ICS = TryContextuallyConvertToBool(From); 3127 if (!ICS.isBad()) 3128 return PerformImplicitConversion(From, Context.BoolTy, ICS, AA_Converting); 3129 3130 if (!DiagnoseMultipleUserDefinedConversion(From, Context.BoolTy)) 3131 return Diag(From->getSourceRange().getBegin(), 3132 diag::err_typecheck_bool_condition) 3133 << From->getType() << From->getSourceRange(); 3134 return true; 3135} 3136 3137/// TryContextuallyConvertToObjCId - Attempt to contextually convert the 3138/// expression From to 'id'. 3139ImplicitConversionSequence Sema::TryContextuallyConvertToObjCId(Expr *From) { 3140 QualType Ty = Context.getObjCIdType(); 3141 return TryImplicitConversion(From, Ty, 3142 // FIXME: Are these flags correct? 3143 /*SuppressUserConversions=*/false, 3144 /*AllowExplicit=*/true, 3145 /*InOverloadResolution=*/false); 3146} 3147 3148/// PerformContextuallyConvertToObjCId - Perform a contextual conversion 3149/// of the expression From to 'id'. 3150bool Sema::PerformContextuallyConvertToObjCId(Expr *&From) { 3151 QualType Ty = Context.getObjCIdType(); 3152 ImplicitConversionSequence ICS = TryContextuallyConvertToObjCId(From); 3153 if (!ICS.isBad()) 3154 return PerformImplicitConversion(From, Ty, ICS, AA_Converting); 3155 return true; 3156} 3157 3158/// \brief Attempt to convert the given expression to an integral or 3159/// enumeration type. 3160/// 3161/// This routine will attempt to convert an expression of class type to an 3162/// integral or enumeration type, if that class type only has a single 3163/// conversion to an integral or enumeration type. 3164/// 3165/// \param Loc The source location of the construct that requires the 3166/// conversion. 3167/// 3168/// \param FromE The expression we're converting from. 3169/// 3170/// \param NotIntDiag The diagnostic to be emitted if the expression does not 3171/// have integral or enumeration type. 3172/// 3173/// \param IncompleteDiag The diagnostic to be emitted if the expression has 3174/// incomplete class type. 3175/// 3176/// \param ExplicitConvDiag The diagnostic to be emitted if we're calling an 3177/// explicit conversion function (because no implicit conversion functions 3178/// were available). This is a recovery mode. 3179/// 3180/// \param ExplicitConvNote The note to be emitted with \p ExplicitConvDiag, 3181/// showing which conversion was picked. 3182/// 3183/// \param AmbigDiag The diagnostic to be emitted if there is more than one 3184/// conversion function that could convert to integral or enumeration type. 3185/// 3186/// \param AmbigNote The note to be emitted with \p AmbigDiag for each 3187/// usable conversion function. 3188/// 3189/// \param ConvDiag The diagnostic to be emitted if we are calling a conversion 3190/// function, which may be an extension in this case. 3191/// 3192/// \returns The expression, converted to an integral or enumeration type if 3193/// successful. 3194Sema::OwningExprResult 3195Sema::ConvertToIntegralOrEnumerationType(SourceLocation Loc, Expr *From, 3196 const PartialDiagnostic &NotIntDiag, 3197 const PartialDiagnostic &IncompleteDiag, 3198 const PartialDiagnostic &ExplicitConvDiag, 3199 const PartialDiagnostic &ExplicitConvNote, 3200 const PartialDiagnostic &AmbigDiag, 3201 const PartialDiagnostic &AmbigNote, 3202 const PartialDiagnostic &ConvDiag) { 3203 // We can't perform any more checking for type-dependent expressions. 3204 if (From->isTypeDependent()) 3205 return Owned(From); 3206 3207 // If the expression already has integral or enumeration type, we're golden. 3208 QualType T = From->getType(); 3209 if (T->isIntegralOrEnumerationType()) 3210 return Owned(From); 3211 3212 // FIXME: Check for missing '()' if T is a function type? 3213 3214 // If we don't have a class type in C++, there's no way we can get an 3215 // expression of integral or enumeration type. 3216 const RecordType *RecordTy = T->getAs<RecordType>(); 3217 if (!RecordTy || !getLangOptions().CPlusPlus) { 3218 Diag(Loc, NotIntDiag) 3219 << T << From->getSourceRange(); 3220 return Owned(From); 3221 } 3222 3223 // We must have a complete class type. 3224 if (RequireCompleteType(Loc, T, IncompleteDiag)) 3225 return Owned(From); 3226 3227 // Look for a conversion to an integral or enumeration type. 3228 UnresolvedSet<4> ViableConversions; 3229 UnresolvedSet<4> ExplicitConversions; 3230 const UnresolvedSetImpl *Conversions 3231 = cast<CXXRecordDecl>(RecordTy->getDecl())->getVisibleConversionFunctions(); 3232 3233 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 3234 E = Conversions->end(); 3235 I != E; 3236 ++I) { 3237 if (CXXConversionDecl *Conversion 3238 = dyn_cast<CXXConversionDecl>((*I)->getUnderlyingDecl())) 3239 if (Conversion->getConversionType().getNonReferenceType() 3240 ->isIntegralOrEnumerationType()) { 3241 if (Conversion->isExplicit()) 3242 ExplicitConversions.addDecl(I.getDecl(), I.getAccess()); 3243 else 3244 ViableConversions.addDecl(I.getDecl(), I.getAccess()); 3245 } 3246 } 3247 3248 switch (ViableConversions.size()) { 3249 case 0: 3250 if (ExplicitConversions.size() == 1) { 3251 DeclAccessPair Found = ExplicitConversions[0]; 3252 CXXConversionDecl *Conversion 3253 = cast<CXXConversionDecl>(Found->getUnderlyingDecl()); 3254 3255 // The user probably meant to invoke the given explicit 3256 // conversion; use it. 3257 QualType ConvTy 3258 = Conversion->getConversionType().getNonReferenceType(); 3259 std::string TypeStr; 3260 ConvTy.getAsStringInternal(TypeStr, Context.PrintingPolicy); 3261 3262 Diag(Loc, ExplicitConvDiag) 3263 << T << ConvTy 3264 << FixItHint::CreateInsertion(From->getLocStart(), 3265 "static_cast<" + TypeStr + ">(") 3266 << FixItHint::CreateInsertion(PP.getLocForEndOfToken(From->getLocEnd()), 3267 ")"); 3268 Diag(Conversion->getLocation(), ExplicitConvNote) 3269 << ConvTy->isEnumeralType() << ConvTy; 3270 3271 // If we aren't in a SFINAE context, build a call to the 3272 // explicit conversion function. 3273 if (isSFINAEContext()) 3274 return ExprError(); 3275 3276 CheckMemberOperatorAccess(From->getExprLoc(), From, 0, Found); 3277 From = BuildCXXMemberCallExpr(From, Found, Conversion); 3278 } 3279 3280 // We'll complain below about a non-integral condition type. 3281 break; 3282 3283 case 1: { 3284 // Apply this conversion. 3285 DeclAccessPair Found = ViableConversions[0]; 3286 CheckMemberOperatorAccess(From->getExprLoc(), From, 0, Found); 3287 3288 CXXConversionDecl *Conversion 3289 = cast<CXXConversionDecl>(Found->getUnderlyingDecl()); 3290 QualType ConvTy 3291 = Conversion->getConversionType().getNonReferenceType(); 3292 if (ConvDiag.getDiagID()) { 3293 if (isSFINAEContext()) 3294 return ExprError(); 3295 3296 Diag(Loc, ConvDiag) 3297 << T << ConvTy->isEnumeralType() << ConvTy << From->getSourceRange(); 3298 } 3299 3300 From = BuildCXXMemberCallExpr(From, Found, 3301 cast<CXXConversionDecl>(Found->getUnderlyingDecl())); 3302 break; 3303 } 3304 3305 default: 3306 Diag(Loc, AmbigDiag) 3307 << T << From->getSourceRange(); 3308 for (unsigned I = 0, N = ViableConversions.size(); I != N; ++I) { 3309 CXXConversionDecl *Conv 3310 = cast<CXXConversionDecl>(ViableConversions[I]->getUnderlyingDecl()); 3311 QualType ConvTy = Conv->getConversionType().getNonReferenceType(); 3312 Diag(Conv->getLocation(), AmbigNote) 3313 << ConvTy->isEnumeralType() << ConvTy; 3314 } 3315 return Owned(From); 3316 } 3317 3318 if (!From->getType()->isIntegralOrEnumerationType()) 3319 Diag(Loc, NotIntDiag) 3320 << From->getType() << From->getSourceRange(); 3321 3322 return Owned(From); 3323} 3324 3325/// AddOverloadCandidate - Adds the given function to the set of 3326/// candidate functions, using the given function call arguments. If 3327/// @p SuppressUserConversions, then don't allow user-defined 3328/// conversions via constructors or conversion operators. 3329/// 3330/// \para PartialOverloading true if we are performing "partial" overloading 3331/// based on an incomplete set of function arguments. This feature is used by 3332/// code completion. 3333void 3334Sema::AddOverloadCandidate(FunctionDecl *Function, 3335 DeclAccessPair FoundDecl, 3336 Expr **Args, unsigned NumArgs, 3337 OverloadCandidateSet& CandidateSet, 3338 bool SuppressUserConversions, 3339 bool PartialOverloading) { 3340 const FunctionProtoType* Proto 3341 = dyn_cast<FunctionProtoType>(Function->getType()->getAs<FunctionType>()); 3342 assert(Proto && "Functions without a prototype cannot be overloaded"); 3343 assert(!Function->getDescribedFunctionTemplate() && 3344 "Use AddTemplateOverloadCandidate for function templates"); 3345 3346 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Function)) { 3347 if (!isa<CXXConstructorDecl>(Method)) { 3348 // If we get here, it's because we're calling a member function 3349 // that is named without a member access expression (e.g., 3350 // "this->f") that was either written explicitly or created 3351 // implicitly. This can happen with a qualified call to a member 3352 // function, e.g., X::f(). We use an empty type for the implied 3353 // object argument (C++ [over.call.func]p3), and the acting context 3354 // is irrelevant. 3355 AddMethodCandidate(Method, FoundDecl, Method->getParent(), 3356 QualType(), Args, NumArgs, CandidateSet, 3357 SuppressUserConversions); 3358 return; 3359 } 3360 // We treat a constructor like a non-member function, since its object 3361 // argument doesn't participate in overload resolution. 3362 } 3363 3364 if (!CandidateSet.isNewCandidate(Function)) 3365 return; 3366 3367 // Overload resolution is always an unevaluated context. 3368 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 3369 3370 if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(Function)){ 3371 // C++ [class.copy]p3: 3372 // A member function template is never instantiated to perform the copy 3373 // of a class object to an object of its class type. 3374 QualType ClassType = Context.getTypeDeclType(Constructor->getParent()); 3375 if (NumArgs == 1 && 3376 Constructor->isCopyConstructorLikeSpecialization() && 3377 (Context.hasSameUnqualifiedType(ClassType, Args[0]->getType()) || 3378 IsDerivedFrom(Args[0]->getType(), ClassType))) 3379 return; 3380 } 3381 3382 // Add this candidate 3383 CandidateSet.push_back(OverloadCandidate()); 3384 OverloadCandidate& Candidate = CandidateSet.back(); 3385 Candidate.FoundDecl = FoundDecl; 3386 Candidate.Function = Function; 3387 Candidate.Viable = true; 3388 Candidate.IsSurrogate = false; 3389 Candidate.IgnoreObjectArgument = false; 3390 3391 unsigned NumArgsInProto = Proto->getNumArgs(); 3392 3393 // (C++ 13.3.2p2): A candidate function having fewer than m 3394 // parameters is viable only if it has an ellipsis in its parameter 3395 // list (8.3.5). 3396 if ((NumArgs + (PartialOverloading && NumArgs)) > NumArgsInProto && 3397 !Proto->isVariadic()) { 3398 Candidate.Viable = false; 3399 Candidate.FailureKind = ovl_fail_too_many_arguments; 3400 return; 3401 } 3402 3403 // (C++ 13.3.2p2): A candidate function having more than m parameters 3404 // is viable only if the (m+1)st parameter has a default argument 3405 // (8.3.6). For the purposes of overload resolution, the 3406 // parameter list is truncated on the right, so that there are 3407 // exactly m parameters. 3408 unsigned MinRequiredArgs = Function->getMinRequiredArguments(); 3409 if (NumArgs < MinRequiredArgs && !PartialOverloading) { 3410 // Not enough arguments. 3411 Candidate.Viable = false; 3412 Candidate.FailureKind = ovl_fail_too_few_arguments; 3413 return; 3414 } 3415 3416 // Determine the implicit conversion sequences for each of the 3417 // arguments. 3418 Candidate.Conversions.resize(NumArgs); 3419 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 3420 if (ArgIdx < NumArgsInProto) { 3421 // (C++ 13.3.2p3): for F to be a viable function, there shall 3422 // exist for each argument an implicit conversion sequence 3423 // (13.3.3.1) that converts that argument to the corresponding 3424 // parameter of F. 3425 QualType ParamType = Proto->getArgType(ArgIdx); 3426 Candidate.Conversions[ArgIdx] 3427 = TryCopyInitialization(*this, Args[ArgIdx], ParamType, 3428 SuppressUserConversions, 3429 /*InOverloadResolution=*/true); 3430 if (Candidate.Conversions[ArgIdx].isBad()) { 3431 Candidate.Viable = false; 3432 Candidate.FailureKind = ovl_fail_bad_conversion; 3433 break; 3434 } 3435 } else { 3436 // (C++ 13.3.2p2): For the purposes of overload resolution, any 3437 // argument for which there is no corresponding parameter is 3438 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 3439 Candidate.Conversions[ArgIdx].setEllipsis(); 3440 } 3441 } 3442} 3443 3444/// \brief Add all of the function declarations in the given function set to 3445/// the overload canddiate set. 3446void Sema::AddFunctionCandidates(const UnresolvedSetImpl &Fns, 3447 Expr **Args, unsigned NumArgs, 3448 OverloadCandidateSet& CandidateSet, 3449 bool SuppressUserConversions) { 3450 for (UnresolvedSetIterator F = Fns.begin(), E = Fns.end(); F != E; ++F) { 3451 NamedDecl *D = F.getDecl()->getUnderlyingDecl(); 3452 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { 3453 if (isa<CXXMethodDecl>(FD) && !cast<CXXMethodDecl>(FD)->isStatic()) 3454 AddMethodCandidate(cast<CXXMethodDecl>(FD), F.getPair(), 3455 cast<CXXMethodDecl>(FD)->getParent(), 3456 Args[0]->getType(), Args + 1, NumArgs - 1, 3457 CandidateSet, SuppressUserConversions); 3458 else 3459 AddOverloadCandidate(FD, F.getPair(), Args, NumArgs, CandidateSet, 3460 SuppressUserConversions); 3461 } else { 3462 FunctionTemplateDecl *FunTmpl = cast<FunctionTemplateDecl>(D); 3463 if (isa<CXXMethodDecl>(FunTmpl->getTemplatedDecl()) && 3464 !cast<CXXMethodDecl>(FunTmpl->getTemplatedDecl())->isStatic()) 3465 AddMethodTemplateCandidate(FunTmpl, F.getPair(), 3466 cast<CXXRecordDecl>(FunTmpl->getDeclContext()), 3467 /*FIXME: explicit args */ 0, 3468 Args[0]->getType(), Args + 1, NumArgs - 1, 3469 CandidateSet, 3470 SuppressUserConversions); 3471 else 3472 AddTemplateOverloadCandidate(FunTmpl, F.getPair(), 3473 /*FIXME: explicit args */ 0, 3474 Args, NumArgs, CandidateSet, 3475 SuppressUserConversions); 3476 } 3477 } 3478} 3479 3480/// AddMethodCandidate - Adds a named decl (which is some kind of 3481/// method) as a method candidate to the given overload set. 3482void Sema::AddMethodCandidate(DeclAccessPair FoundDecl, 3483 QualType ObjectType, 3484 Expr **Args, unsigned NumArgs, 3485 OverloadCandidateSet& CandidateSet, 3486 bool SuppressUserConversions) { 3487 NamedDecl *Decl = FoundDecl.getDecl(); 3488 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(Decl->getDeclContext()); 3489 3490 if (isa<UsingShadowDecl>(Decl)) 3491 Decl = cast<UsingShadowDecl>(Decl)->getTargetDecl(); 3492 3493 if (FunctionTemplateDecl *TD = dyn_cast<FunctionTemplateDecl>(Decl)) { 3494 assert(isa<CXXMethodDecl>(TD->getTemplatedDecl()) && 3495 "Expected a member function template"); 3496 AddMethodTemplateCandidate(TD, FoundDecl, ActingContext, 3497 /*ExplicitArgs*/ 0, 3498 ObjectType, Args, NumArgs, 3499 CandidateSet, 3500 SuppressUserConversions); 3501 } else { 3502 AddMethodCandidate(cast<CXXMethodDecl>(Decl), FoundDecl, ActingContext, 3503 ObjectType, Args, NumArgs, 3504 CandidateSet, SuppressUserConversions); 3505 } 3506} 3507 3508/// AddMethodCandidate - Adds the given C++ member function to the set 3509/// of candidate functions, using the given function call arguments 3510/// and the object argument (@c Object). For example, in a call 3511/// @c o.f(a1,a2), @c Object will contain @c o and @c Args will contain 3512/// both @c a1 and @c a2. If @p SuppressUserConversions, then don't 3513/// allow user-defined conversions via constructors or conversion 3514/// operators. 3515void 3516Sema::AddMethodCandidate(CXXMethodDecl *Method, DeclAccessPair FoundDecl, 3517 CXXRecordDecl *ActingContext, QualType ObjectType, 3518 Expr **Args, unsigned NumArgs, 3519 OverloadCandidateSet& CandidateSet, 3520 bool SuppressUserConversions) { 3521 const FunctionProtoType* Proto 3522 = dyn_cast<FunctionProtoType>(Method->getType()->getAs<FunctionType>()); 3523 assert(Proto && "Methods without a prototype cannot be overloaded"); 3524 assert(!isa<CXXConstructorDecl>(Method) && 3525 "Use AddOverloadCandidate for constructors"); 3526 3527 if (!CandidateSet.isNewCandidate(Method)) 3528 return; 3529 3530 // Overload resolution is always an unevaluated context. 3531 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 3532 3533 // Add this candidate 3534 CandidateSet.push_back(OverloadCandidate()); 3535 OverloadCandidate& Candidate = CandidateSet.back(); 3536 Candidate.FoundDecl = FoundDecl; 3537 Candidate.Function = Method; 3538 Candidate.IsSurrogate = false; 3539 Candidate.IgnoreObjectArgument = false; 3540 3541 unsigned NumArgsInProto = Proto->getNumArgs(); 3542 3543 // (C++ 13.3.2p2): A candidate function having fewer than m 3544 // parameters is viable only if it has an ellipsis in its parameter 3545 // list (8.3.5). 3546 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 3547 Candidate.Viable = false; 3548 Candidate.FailureKind = ovl_fail_too_many_arguments; 3549 return; 3550 } 3551 3552 // (C++ 13.3.2p2): A candidate function having more than m parameters 3553 // is viable only if the (m+1)st parameter has a default argument 3554 // (8.3.6). For the purposes of overload resolution, the 3555 // parameter list is truncated on the right, so that there are 3556 // exactly m parameters. 3557 unsigned MinRequiredArgs = Method->getMinRequiredArguments(); 3558 if (NumArgs < MinRequiredArgs) { 3559 // Not enough arguments. 3560 Candidate.Viable = false; 3561 Candidate.FailureKind = ovl_fail_too_few_arguments; 3562 return; 3563 } 3564 3565 Candidate.Viable = true; 3566 Candidate.Conversions.resize(NumArgs + 1); 3567 3568 if (Method->isStatic() || ObjectType.isNull()) 3569 // The implicit object argument is ignored. 3570 Candidate.IgnoreObjectArgument = true; 3571 else { 3572 // Determine the implicit conversion sequence for the object 3573 // parameter. 3574 Candidate.Conversions[0] 3575 = TryObjectArgumentInitialization(ObjectType, Method, ActingContext); 3576 if (Candidate.Conversions[0].isBad()) { 3577 Candidate.Viable = false; 3578 Candidate.FailureKind = ovl_fail_bad_conversion; 3579 return; 3580 } 3581 } 3582 3583 // Determine the implicit conversion sequences for each of the 3584 // arguments. 3585 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 3586 if (ArgIdx < NumArgsInProto) { 3587 // (C++ 13.3.2p3): for F to be a viable function, there shall 3588 // exist for each argument an implicit conversion sequence 3589 // (13.3.3.1) that converts that argument to the corresponding 3590 // parameter of F. 3591 QualType ParamType = Proto->getArgType(ArgIdx); 3592 Candidate.Conversions[ArgIdx + 1] 3593 = TryCopyInitialization(*this, Args[ArgIdx], ParamType, 3594 SuppressUserConversions, 3595 /*InOverloadResolution=*/true); 3596 if (Candidate.Conversions[ArgIdx + 1].isBad()) { 3597 Candidate.Viable = false; 3598 Candidate.FailureKind = ovl_fail_bad_conversion; 3599 break; 3600 } 3601 } else { 3602 // (C++ 13.3.2p2): For the purposes of overload resolution, any 3603 // argument for which there is no corresponding parameter is 3604 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 3605 Candidate.Conversions[ArgIdx + 1].setEllipsis(); 3606 } 3607 } 3608} 3609 3610/// \brief Add a C++ member function template as a candidate to the candidate 3611/// set, using template argument deduction to produce an appropriate member 3612/// function template specialization. 3613void 3614Sema::AddMethodTemplateCandidate(FunctionTemplateDecl *MethodTmpl, 3615 DeclAccessPair FoundDecl, 3616 CXXRecordDecl *ActingContext, 3617 const TemplateArgumentListInfo *ExplicitTemplateArgs, 3618 QualType ObjectType, 3619 Expr **Args, unsigned NumArgs, 3620 OverloadCandidateSet& CandidateSet, 3621 bool SuppressUserConversions) { 3622 if (!CandidateSet.isNewCandidate(MethodTmpl)) 3623 return; 3624 3625 // C++ [over.match.funcs]p7: 3626 // In each case where a candidate is a function template, candidate 3627 // function template specializations are generated using template argument 3628 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 3629 // candidate functions in the usual way.113) A given name can refer to one 3630 // or more function templates and also to a set of overloaded non-template 3631 // functions. In such a case, the candidate functions generated from each 3632 // function template are combined with the set of non-template candidate 3633 // functions. 3634 TemplateDeductionInfo Info(Context, CandidateSet.getLocation()); 3635 FunctionDecl *Specialization = 0; 3636 if (TemplateDeductionResult Result 3637 = DeduceTemplateArguments(MethodTmpl, ExplicitTemplateArgs, 3638 Args, NumArgs, Specialization, Info)) { 3639 CandidateSet.push_back(OverloadCandidate()); 3640 OverloadCandidate &Candidate = CandidateSet.back(); 3641 Candidate.FoundDecl = FoundDecl; 3642 Candidate.Function = MethodTmpl->getTemplatedDecl(); 3643 Candidate.Viable = false; 3644 Candidate.FailureKind = ovl_fail_bad_deduction; 3645 Candidate.IsSurrogate = false; 3646 Candidate.IgnoreObjectArgument = false; 3647 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result, 3648 Info); 3649 return; 3650 } 3651 3652 // Add the function template specialization produced by template argument 3653 // deduction as a candidate. 3654 assert(Specialization && "Missing member function template specialization?"); 3655 assert(isa<CXXMethodDecl>(Specialization) && 3656 "Specialization is not a member function?"); 3657 AddMethodCandidate(cast<CXXMethodDecl>(Specialization), FoundDecl, 3658 ActingContext, ObjectType, Args, NumArgs, 3659 CandidateSet, SuppressUserConversions); 3660} 3661 3662/// \brief Add a C++ function template specialization as a candidate 3663/// in the candidate set, using template argument deduction to produce 3664/// an appropriate function template specialization. 3665void 3666Sema::AddTemplateOverloadCandidate(FunctionTemplateDecl *FunctionTemplate, 3667 DeclAccessPair FoundDecl, 3668 const TemplateArgumentListInfo *ExplicitTemplateArgs, 3669 Expr **Args, unsigned NumArgs, 3670 OverloadCandidateSet& CandidateSet, 3671 bool SuppressUserConversions) { 3672 if (!CandidateSet.isNewCandidate(FunctionTemplate)) 3673 return; 3674 3675 // C++ [over.match.funcs]p7: 3676 // In each case where a candidate is a function template, candidate 3677 // function template specializations are generated using template argument 3678 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 3679 // candidate functions in the usual way.113) A given name can refer to one 3680 // or more function templates and also to a set of overloaded non-template 3681 // functions. In such a case, the candidate functions generated from each 3682 // function template are combined with the set of non-template candidate 3683 // functions. 3684 TemplateDeductionInfo Info(Context, CandidateSet.getLocation()); 3685 FunctionDecl *Specialization = 0; 3686 if (TemplateDeductionResult Result 3687 = DeduceTemplateArguments(FunctionTemplate, ExplicitTemplateArgs, 3688 Args, NumArgs, Specialization, Info)) { 3689 CandidateSet.push_back(OverloadCandidate()); 3690 OverloadCandidate &Candidate = CandidateSet.back(); 3691 Candidate.FoundDecl = FoundDecl; 3692 Candidate.Function = FunctionTemplate->getTemplatedDecl(); 3693 Candidate.Viable = false; 3694 Candidate.FailureKind = ovl_fail_bad_deduction; 3695 Candidate.IsSurrogate = false; 3696 Candidate.IgnoreObjectArgument = false; 3697 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result, 3698 Info); 3699 return; 3700 } 3701 3702 // Add the function template specialization produced by template argument 3703 // deduction as a candidate. 3704 assert(Specialization && "Missing function template specialization?"); 3705 AddOverloadCandidate(Specialization, FoundDecl, Args, NumArgs, CandidateSet, 3706 SuppressUserConversions); 3707} 3708 3709/// AddConversionCandidate - Add a C++ conversion function as a 3710/// candidate in the candidate set (C++ [over.match.conv], 3711/// C++ [over.match.copy]). From is the expression we're converting from, 3712/// and ToType is the type that we're eventually trying to convert to 3713/// (which may or may not be the same type as the type that the 3714/// conversion function produces). 3715void 3716Sema::AddConversionCandidate(CXXConversionDecl *Conversion, 3717 DeclAccessPair FoundDecl, 3718 CXXRecordDecl *ActingContext, 3719 Expr *From, QualType ToType, 3720 OverloadCandidateSet& CandidateSet) { 3721 assert(!Conversion->getDescribedFunctionTemplate() && 3722 "Conversion function templates use AddTemplateConversionCandidate"); 3723 QualType ConvType = Conversion->getConversionType().getNonReferenceType(); 3724 if (!CandidateSet.isNewCandidate(Conversion)) 3725 return; 3726 3727 // Overload resolution is always an unevaluated context. 3728 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 3729 3730 // Add this candidate 3731 CandidateSet.push_back(OverloadCandidate()); 3732 OverloadCandidate& Candidate = CandidateSet.back(); 3733 Candidate.FoundDecl = FoundDecl; 3734 Candidate.Function = Conversion; 3735 Candidate.IsSurrogate = false; 3736 Candidate.IgnoreObjectArgument = false; 3737 Candidate.FinalConversion.setAsIdentityConversion(); 3738 Candidate.FinalConversion.setFromType(ConvType); 3739 Candidate.FinalConversion.setAllToTypes(ToType); 3740 Candidate.Viable = true; 3741 Candidate.Conversions.resize(1); 3742 3743 // C++ [over.match.funcs]p4: 3744 // For conversion functions, the function is considered to be a member of 3745 // the class of the implicit implied object argument for the purpose of 3746 // defining the type of the implicit object parameter. 3747 // 3748 // Determine the implicit conversion sequence for the implicit 3749 // object parameter. 3750 QualType ImplicitParamType = From->getType(); 3751 if (const PointerType *FromPtrType = ImplicitParamType->getAs<PointerType>()) 3752 ImplicitParamType = FromPtrType->getPointeeType(); 3753 CXXRecordDecl *ConversionContext 3754 = cast<CXXRecordDecl>(ImplicitParamType->getAs<RecordType>()->getDecl()); 3755 3756 Candidate.Conversions[0] 3757 = TryObjectArgumentInitialization(From->getType(), Conversion, 3758 ConversionContext); 3759 3760 if (Candidate.Conversions[0].isBad()) { 3761 Candidate.Viable = false; 3762 Candidate.FailureKind = ovl_fail_bad_conversion; 3763 return; 3764 } 3765 3766 // We won't go through a user-define type conversion function to convert a 3767 // derived to base as such conversions are given Conversion Rank. They only 3768 // go through a copy constructor. 13.3.3.1.2-p4 [over.ics.user] 3769 QualType FromCanon 3770 = Context.getCanonicalType(From->getType().getUnqualifiedType()); 3771 QualType ToCanon = Context.getCanonicalType(ToType).getUnqualifiedType(); 3772 if (FromCanon == ToCanon || IsDerivedFrom(FromCanon, ToCanon)) { 3773 Candidate.Viable = false; 3774 Candidate.FailureKind = ovl_fail_trivial_conversion; 3775 return; 3776 } 3777 3778 // To determine what the conversion from the result of calling the 3779 // conversion function to the type we're eventually trying to 3780 // convert to (ToType), we need to synthesize a call to the 3781 // conversion function and attempt copy initialization from it. This 3782 // makes sure that we get the right semantics with respect to 3783 // lvalues/rvalues and the type. Fortunately, we can allocate this 3784 // call on the stack and we don't need its arguments to be 3785 // well-formed. 3786 DeclRefExpr ConversionRef(Conversion, Conversion->getType(), 3787 From->getLocStart()); 3788 ImplicitCastExpr ConversionFn(ImplicitCastExpr::OnStack, 3789 Context.getPointerType(Conversion->getType()), 3790 CastExpr::CK_FunctionToPointerDecay, 3791 &ConversionRef, ImplicitCastExpr::RValue); 3792 3793 // Note that it is safe to allocate CallExpr on the stack here because 3794 // there are 0 arguments (i.e., nothing is allocated using ASTContext's 3795 // allocator). 3796 CallExpr Call(Context, &ConversionFn, 0, 0, 3797 Conversion->getConversionType().getNonLValueExprType(Context), 3798 From->getLocStart()); 3799 ImplicitConversionSequence ICS = 3800 TryCopyInitialization(*this, &Call, ToType, 3801 /*SuppressUserConversions=*/true, 3802 /*InOverloadResolution=*/false); 3803 3804 switch (ICS.getKind()) { 3805 case ImplicitConversionSequence::StandardConversion: 3806 Candidate.FinalConversion = ICS.Standard; 3807 3808 // C++ [over.ics.user]p3: 3809 // If the user-defined conversion is specified by a specialization of a 3810 // conversion function template, the second standard conversion sequence 3811 // shall have exact match rank. 3812 if (Conversion->getPrimaryTemplate() && 3813 GetConversionRank(ICS.Standard.Second) != ICR_Exact_Match) { 3814 Candidate.Viable = false; 3815 Candidate.FailureKind = ovl_fail_final_conversion_not_exact; 3816 } 3817 3818 break; 3819 3820 case ImplicitConversionSequence::BadConversion: 3821 Candidate.Viable = false; 3822 Candidate.FailureKind = ovl_fail_bad_final_conversion; 3823 break; 3824 3825 default: 3826 assert(false && 3827 "Can only end up with a standard conversion sequence or failure"); 3828 } 3829} 3830 3831/// \brief Adds a conversion function template specialization 3832/// candidate to the overload set, using template argument deduction 3833/// to deduce the template arguments of the conversion function 3834/// template from the type that we are converting to (C++ 3835/// [temp.deduct.conv]). 3836void 3837Sema::AddTemplateConversionCandidate(FunctionTemplateDecl *FunctionTemplate, 3838 DeclAccessPair FoundDecl, 3839 CXXRecordDecl *ActingDC, 3840 Expr *From, QualType ToType, 3841 OverloadCandidateSet &CandidateSet) { 3842 assert(isa<CXXConversionDecl>(FunctionTemplate->getTemplatedDecl()) && 3843 "Only conversion function templates permitted here"); 3844 3845 if (!CandidateSet.isNewCandidate(FunctionTemplate)) 3846 return; 3847 3848 TemplateDeductionInfo Info(Context, CandidateSet.getLocation()); 3849 CXXConversionDecl *Specialization = 0; 3850 if (TemplateDeductionResult Result 3851 = DeduceTemplateArguments(FunctionTemplate, ToType, 3852 Specialization, Info)) { 3853 CandidateSet.push_back(OverloadCandidate()); 3854 OverloadCandidate &Candidate = CandidateSet.back(); 3855 Candidate.FoundDecl = FoundDecl; 3856 Candidate.Function = FunctionTemplate->getTemplatedDecl(); 3857 Candidate.Viable = false; 3858 Candidate.FailureKind = ovl_fail_bad_deduction; 3859 Candidate.IsSurrogate = false; 3860 Candidate.IgnoreObjectArgument = false; 3861 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result, 3862 Info); 3863 return; 3864 } 3865 3866 // Add the conversion function template specialization produced by 3867 // template argument deduction as a candidate. 3868 assert(Specialization && "Missing function template specialization?"); 3869 AddConversionCandidate(Specialization, FoundDecl, ActingDC, From, ToType, 3870 CandidateSet); 3871} 3872 3873/// AddSurrogateCandidate - Adds a "surrogate" candidate function that 3874/// converts the given @c Object to a function pointer via the 3875/// conversion function @c Conversion, and then attempts to call it 3876/// with the given arguments (C++ [over.call.object]p2-4). Proto is 3877/// the type of function that we'll eventually be calling. 3878void Sema::AddSurrogateCandidate(CXXConversionDecl *Conversion, 3879 DeclAccessPair FoundDecl, 3880 CXXRecordDecl *ActingContext, 3881 const FunctionProtoType *Proto, 3882 QualType ObjectType, 3883 Expr **Args, unsigned NumArgs, 3884 OverloadCandidateSet& CandidateSet) { 3885 if (!CandidateSet.isNewCandidate(Conversion)) 3886 return; 3887 3888 // Overload resolution is always an unevaluated context. 3889 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 3890 3891 CandidateSet.push_back(OverloadCandidate()); 3892 OverloadCandidate& Candidate = CandidateSet.back(); 3893 Candidate.FoundDecl = FoundDecl; 3894 Candidate.Function = 0; 3895 Candidate.Surrogate = Conversion; 3896 Candidate.Viable = true; 3897 Candidate.IsSurrogate = true; 3898 Candidate.IgnoreObjectArgument = false; 3899 Candidate.Conversions.resize(NumArgs + 1); 3900 3901 // Determine the implicit conversion sequence for the implicit 3902 // object parameter. 3903 ImplicitConversionSequence ObjectInit 3904 = TryObjectArgumentInitialization(ObjectType, Conversion, ActingContext); 3905 if (ObjectInit.isBad()) { 3906 Candidate.Viable = false; 3907 Candidate.FailureKind = ovl_fail_bad_conversion; 3908 Candidate.Conversions[0] = ObjectInit; 3909 return; 3910 } 3911 3912 // The first conversion is actually a user-defined conversion whose 3913 // first conversion is ObjectInit's standard conversion (which is 3914 // effectively a reference binding). Record it as such. 3915 Candidate.Conversions[0].setUserDefined(); 3916 Candidate.Conversions[0].UserDefined.Before = ObjectInit.Standard; 3917 Candidate.Conversions[0].UserDefined.EllipsisConversion = false; 3918 Candidate.Conversions[0].UserDefined.ConversionFunction = Conversion; 3919 Candidate.Conversions[0].UserDefined.After 3920 = Candidate.Conversions[0].UserDefined.Before; 3921 Candidate.Conversions[0].UserDefined.After.setAsIdentityConversion(); 3922 3923 // Find the 3924 unsigned NumArgsInProto = Proto->getNumArgs(); 3925 3926 // (C++ 13.3.2p2): A candidate function having fewer than m 3927 // parameters is viable only if it has an ellipsis in its parameter 3928 // list (8.3.5). 3929 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 3930 Candidate.Viable = false; 3931 Candidate.FailureKind = ovl_fail_too_many_arguments; 3932 return; 3933 } 3934 3935 // Function types don't have any default arguments, so just check if 3936 // we have enough arguments. 3937 if (NumArgs < NumArgsInProto) { 3938 // Not enough arguments. 3939 Candidate.Viable = false; 3940 Candidate.FailureKind = ovl_fail_too_few_arguments; 3941 return; 3942 } 3943 3944 // Determine the implicit conversion sequences for each of the 3945 // arguments. 3946 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 3947 if (ArgIdx < NumArgsInProto) { 3948 // (C++ 13.3.2p3): for F to be a viable function, there shall 3949 // exist for each argument an implicit conversion sequence 3950 // (13.3.3.1) that converts that argument to the corresponding 3951 // parameter of F. 3952 QualType ParamType = Proto->getArgType(ArgIdx); 3953 Candidate.Conversions[ArgIdx + 1] 3954 = TryCopyInitialization(*this, Args[ArgIdx], ParamType, 3955 /*SuppressUserConversions=*/false, 3956 /*InOverloadResolution=*/false); 3957 if (Candidate.Conversions[ArgIdx + 1].isBad()) { 3958 Candidate.Viable = false; 3959 Candidate.FailureKind = ovl_fail_bad_conversion; 3960 break; 3961 } 3962 } else { 3963 // (C++ 13.3.2p2): For the purposes of overload resolution, any 3964 // argument for which there is no corresponding parameter is 3965 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 3966 Candidate.Conversions[ArgIdx + 1].setEllipsis(); 3967 } 3968 } 3969} 3970 3971/// \brief Add overload candidates for overloaded operators that are 3972/// member functions. 3973/// 3974/// Add the overloaded operator candidates that are member functions 3975/// for the operator Op that was used in an operator expression such 3976/// as "x Op y". , Args/NumArgs provides the operator arguments, and 3977/// CandidateSet will store the added overload candidates. (C++ 3978/// [over.match.oper]). 3979void Sema::AddMemberOperatorCandidates(OverloadedOperatorKind Op, 3980 SourceLocation OpLoc, 3981 Expr **Args, unsigned NumArgs, 3982 OverloadCandidateSet& CandidateSet, 3983 SourceRange OpRange) { 3984 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 3985 3986 // C++ [over.match.oper]p3: 3987 // For a unary operator @ with an operand of a type whose 3988 // cv-unqualified version is T1, and for a binary operator @ with 3989 // a left operand of a type whose cv-unqualified version is T1 and 3990 // a right operand of a type whose cv-unqualified version is T2, 3991 // three sets of candidate functions, designated member 3992 // candidates, non-member candidates and built-in candidates, are 3993 // constructed as follows: 3994 QualType T1 = Args[0]->getType(); 3995 3996 // -- If T1 is a class type, the set of member candidates is the 3997 // result of the qualified lookup of T1::operator@ 3998 // (13.3.1.1.1); otherwise, the set of member candidates is 3999 // empty. 4000 if (const RecordType *T1Rec = T1->getAs<RecordType>()) { 4001 // Complete the type if it can be completed. Otherwise, we're done. 4002 if (RequireCompleteType(OpLoc, T1, PDiag())) 4003 return; 4004 4005 LookupResult Operators(*this, OpName, OpLoc, LookupOrdinaryName); 4006 LookupQualifiedName(Operators, T1Rec->getDecl()); 4007 Operators.suppressDiagnostics(); 4008 4009 for (LookupResult::iterator Oper = Operators.begin(), 4010 OperEnd = Operators.end(); 4011 Oper != OperEnd; 4012 ++Oper) 4013 AddMethodCandidate(Oper.getPair(), Args[0]->getType(), 4014 Args + 1, NumArgs - 1, CandidateSet, 4015 /* SuppressUserConversions = */ false); 4016 } 4017} 4018 4019/// AddBuiltinCandidate - Add a candidate for a built-in 4020/// operator. ResultTy and ParamTys are the result and parameter types 4021/// of the built-in candidate, respectively. Args and NumArgs are the 4022/// arguments being passed to the candidate. IsAssignmentOperator 4023/// should be true when this built-in candidate is an assignment 4024/// operator. NumContextualBoolArguments is the number of arguments 4025/// (at the beginning of the argument list) that will be contextually 4026/// converted to bool. 4027void Sema::AddBuiltinCandidate(QualType ResultTy, QualType *ParamTys, 4028 Expr **Args, unsigned NumArgs, 4029 OverloadCandidateSet& CandidateSet, 4030 bool IsAssignmentOperator, 4031 unsigned NumContextualBoolArguments) { 4032 // Overload resolution is always an unevaluated context. 4033 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 4034 4035 // Add this candidate 4036 CandidateSet.push_back(OverloadCandidate()); 4037 OverloadCandidate& Candidate = CandidateSet.back(); 4038 Candidate.FoundDecl = DeclAccessPair::make(0, AS_none); 4039 Candidate.Function = 0; 4040 Candidate.IsSurrogate = false; 4041 Candidate.IgnoreObjectArgument = false; 4042 Candidate.BuiltinTypes.ResultTy = ResultTy; 4043 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 4044 Candidate.BuiltinTypes.ParamTypes[ArgIdx] = ParamTys[ArgIdx]; 4045 4046 // Determine the implicit conversion sequences for each of the 4047 // arguments. 4048 Candidate.Viable = true; 4049 Candidate.Conversions.resize(NumArgs); 4050 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 4051 // C++ [over.match.oper]p4: 4052 // For the built-in assignment operators, conversions of the 4053 // left operand are restricted as follows: 4054 // -- no temporaries are introduced to hold the left operand, and 4055 // -- no user-defined conversions are applied to the left 4056 // operand to achieve a type match with the left-most 4057 // parameter of a built-in candidate. 4058 // 4059 // We block these conversions by turning off user-defined 4060 // conversions, since that is the only way that initialization of 4061 // a reference to a non-class type can occur from something that 4062 // is not of the same type. 4063 if (ArgIdx < NumContextualBoolArguments) { 4064 assert(ParamTys[ArgIdx] == Context.BoolTy && 4065 "Contextual conversion to bool requires bool type"); 4066 Candidate.Conversions[ArgIdx] = TryContextuallyConvertToBool(Args[ArgIdx]); 4067 } else { 4068 Candidate.Conversions[ArgIdx] 4069 = TryCopyInitialization(*this, Args[ArgIdx], ParamTys[ArgIdx], 4070 ArgIdx == 0 && IsAssignmentOperator, 4071 /*InOverloadResolution=*/false); 4072 } 4073 if (Candidate.Conversions[ArgIdx].isBad()) { 4074 Candidate.Viable = false; 4075 Candidate.FailureKind = ovl_fail_bad_conversion; 4076 break; 4077 } 4078 } 4079} 4080 4081/// BuiltinCandidateTypeSet - A set of types that will be used for the 4082/// candidate operator functions for built-in operators (C++ 4083/// [over.built]). The types are separated into pointer types and 4084/// enumeration types. 4085class BuiltinCandidateTypeSet { 4086 /// TypeSet - A set of types. 4087 typedef llvm::SmallPtrSet<QualType, 8> TypeSet; 4088 4089 /// PointerTypes - The set of pointer types that will be used in the 4090 /// built-in candidates. 4091 TypeSet PointerTypes; 4092 4093 /// MemberPointerTypes - The set of member pointer types that will be 4094 /// used in the built-in candidates. 4095 TypeSet MemberPointerTypes; 4096 4097 /// EnumerationTypes - The set of enumeration types that will be 4098 /// used in the built-in candidates. 4099 TypeSet EnumerationTypes; 4100 4101 /// \brief The set of vector types that will be used in the built-in 4102 /// candidates. 4103 TypeSet VectorTypes; 4104 4105 /// Sema - The semantic analysis instance where we are building the 4106 /// candidate type set. 4107 Sema &SemaRef; 4108 4109 /// Context - The AST context in which we will build the type sets. 4110 ASTContext &Context; 4111 4112 bool AddPointerWithMoreQualifiedTypeVariants(QualType Ty, 4113 const Qualifiers &VisibleQuals); 4114 bool AddMemberPointerWithMoreQualifiedTypeVariants(QualType Ty); 4115 4116public: 4117 /// iterator - Iterates through the types that are part of the set. 4118 typedef TypeSet::iterator iterator; 4119 4120 BuiltinCandidateTypeSet(Sema &SemaRef) 4121 : SemaRef(SemaRef), Context(SemaRef.Context) { } 4122 4123 void AddTypesConvertedFrom(QualType Ty, 4124 SourceLocation Loc, 4125 bool AllowUserConversions, 4126 bool AllowExplicitConversions, 4127 const Qualifiers &VisibleTypeConversionsQuals); 4128 4129 /// pointer_begin - First pointer type found; 4130 iterator pointer_begin() { return PointerTypes.begin(); } 4131 4132 /// pointer_end - Past the last pointer type found; 4133 iterator pointer_end() { return PointerTypes.end(); } 4134 4135 /// member_pointer_begin - First member pointer type found; 4136 iterator member_pointer_begin() { return MemberPointerTypes.begin(); } 4137 4138 /// member_pointer_end - Past the last member pointer type found; 4139 iterator member_pointer_end() { return MemberPointerTypes.end(); } 4140 4141 /// enumeration_begin - First enumeration type found; 4142 iterator enumeration_begin() { return EnumerationTypes.begin(); } 4143 4144 /// enumeration_end - Past the last enumeration type found; 4145 iterator enumeration_end() { return EnumerationTypes.end(); } 4146 4147 iterator vector_begin() { return VectorTypes.begin(); } 4148 iterator vector_end() { return VectorTypes.end(); } 4149}; 4150 4151/// AddPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty to 4152/// the set of pointer types along with any more-qualified variants of 4153/// that type. For example, if @p Ty is "int const *", this routine 4154/// will add "int const *", "int const volatile *", "int const 4155/// restrict *", and "int const volatile restrict *" to the set of 4156/// pointer types. Returns true if the add of @p Ty itself succeeded, 4157/// false otherwise. 4158/// 4159/// FIXME: what to do about extended qualifiers? 4160bool 4161BuiltinCandidateTypeSet::AddPointerWithMoreQualifiedTypeVariants(QualType Ty, 4162 const Qualifiers &VisibleQuals) { 4163 4164 // Insert this type. 4165 if (!PointerTypes.insert(Ty)) 4166 return false; 4167 4168 QualType PointeeTy; 4169 const PointerType *PointerTy = Ty->getAs<PointerType>(); 4170 bool buildObjCPtr = false; 4171 if (!PointerTy) { 4172 if (const ObjCObjectPointerType *PTy = Ty->getAs<ObjCObjectPointerType>()) { 4173 PointeeTy = PTy->getPointeeType(); 4174 buildObjCPtr = true; 4175 } 4176 else 4177 assert(false && "type was not a pointer type!"); 4178 } 4179 else 4180 PointeeTy = PointerTy->getPointeeType(); 4181 4182 // Don't add qualified variants of arrays. For one, they're not allowed 4183 // (the qualifier would sink to the element type), and for another, the 4184 // only overload situation where it matters is subscript or pointer +- int, 4185 // and those shouldn't have qualifier variants anyway. 4186 if (PointeeTy->isArrayType()) 4187 return true; 4188 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 4189 if (const ConstantArrayType *Array =Context.getAsConstantArrayType(PointeeTy)) 4190 BaseCVR = Array->getElementType().getCVRQualifiers(); 4191 bool hasVolatile = VisibleQuals.hasVolatile(); 4192 bool hasRestrict = VisibleQuals.hasRestrict(); 4193 4194 // Iterate through all strict supersets of BaseCVR. 4195 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 4196 if ((CVR | BaseCVR) != CVR) continue; 4197 // Skip over Volatile/Restrict if no Volatile/Restrict found anywhere 4198 // in the types. 4199 if ((CVR & Qualifiers::Volatile) && !hasVolatile) continue; 4200 if ((CVR & Qualifiers::Restrict) && !hasRestrict) continue; 4201 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 4202 if (!buildObjCPtr) 4203 PointerTypes.insert(Context.getPointerType(QPointeeTy)); 4204 else 4205 PointerTypes.insert(Context.getObjCObjectPointerType(QPointeeTy)); 4206 } 4207 4208 return true; 4209} 4210 4211/// AddMemberPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty 4212/// to the set of pointer types along with any more-qualified variants of 4213/// that type. For example, if @p Ty is "int const *", this routine 4214/// will add "int const *", "int const volatile *", "int const 4215/// restrict *", and "int const volatile restrict *" to the set of 4216/// pointer types. Returns true if the add of @p Ty itself succeeded, 4217/// false otherwise. 4218/// 4219/// FIXME: what to do about extended qualifiers? 4220bool 4221BuiltinCandidateTypeSet::AddMemberPointerWithMoreQualifiedTypeVariants( 4222 QualType Ty) { 4223 // Insert this type. 4224 if (!MemberPointerTypes.insert(Ty)) 4225 return false; 4226 4227 const MemberPointerType *PointerTy = Ty->getAs<MemberPointerType>(); 4228 assert(PointerTy && "type was not a member pointer type!"); 4229 4230 QualType PointeeTy = PointerTy->getPointeeType(); 4231 // Don't add qualified variants of arrays. For one, they're not allowed 4232 // (the qualifier would sink to the element type), and for another, the 4233 // only overload situation where it matters is subscript or pointer +- int, 4234 // and those shouldn't have qualifier variants anyway. 4235 if (PointeeTy->isArrayType()) 4236 return true; 4237 const Type *ClassTy = PointerTy->getClass(); 4238 4239 // Iterate through all strict supersets of the pointee type's CVR 4240 // qualifiers. 4241 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 4242 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 4243 if ((CVR | BaseCVR) != CVR) continue; 4244 4245 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 4246 MemberPointerTypes.insert(Context.getMemberPointerType(QPointeeTy, ClassTy)); 4247 } 4248 4249 return true; 4250} 4251 4252/// AddTypesConvertedFrom - Add each of the types to which the type @p 4253/// Ty can be implicit converted to the given set of @p Types. We're 4254/// primarily interested in pointer types and enumeration types. We also 4255/// take member pointer types, for the conditional operator. 4256/// AllowUserConversions is true if we should look at the conversion 4257/// functions of a class type, and AllowExplicitConversions if we 4258/// should also include the explicit conversion functions of a class 4259/// type. 4260void 4261BuiltinCandidateTypeSet::AddTypesConvertedFrom(QualType Ty, 4262 SourceLocation Loc, 4263 bool AllowUserConversions, 4264 bool AllowExplicitConversions, 4265 const Qualifiers &VisibleQuals) { 4266 // Only deal with canonical types. 4267 Ty = Context.getCanonicalType(Ty); 4268 4269 // Look through reference types; they aren't part of the type of an 4270 // expression for the purposes of conversions. 4271 if (const ReferenceType *RefTy = Ty->getAs<ReferenceType>()) 4272 Ty = RefTy->getPointeeType(); 4273 4274 // We don't care about qualifiers on the type. 4275 Ty = Ty.getLocalUnqualifiedType(); 4276 4277 // If we're dealing with an array type, decay to the pointer. 4278 if (Ty->isArrayType()) 4279 Ty = SemaRef.Context.getArrayDecayedType(Ty); 4280 if (Ty->isObjCIdType() || Ty->isObjCClassType()) 4281 PointerTypes.insert(Ty); 4282 else if (Ty->getAs<PointerType>() || Ty->getAs<ObjCObjectPointerType>()) { 4283 // Insert our type, and its more-qualified variants, into the set 4284 // of types. 4285 if (!AddPointerWithMoreQualifiedTypeVariants(Ty, VisibleQuals)) 4286 return; 4287 } else if (Ty->isMemberPointerType()) { 4288 // Member pointers are far easier, since the pointee can't be converted. 4289 if (!AddMemberPointerWithMoreQualifiedTypeVariants(Ty)) 4290 return; 4291 } else if (Ty->isEnumeralType()) { 4292 EnumerationTypes.insert(Ty); 4293 } else if (Ty->isVectorType()) { 4294 VectorTypes.insert(Ty); 4295 } else if (AllowUserConversions) { 4296 if (const RecordType *TyRec = Ty->getAs<RecordType>()) { 4297 if (SemaRef.RequireCompleteType(Loc, Ty, 0)) { 4298 // No conversion functions in incomplete types. 4299 return; 4300 } 4301 4302 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 4303 const UnresolvedSetImpl *Conversions 4304 = ClassDecl->getVisibleConversionFunctions(); 4305 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 4306 E = Conversions->end(); I != E; ++I) { 4307 NamedDecl *D = I.getDecl(); 4308 if (isa<UsingShadowDecl>(D)) 4309 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 4310 4311 // Skip conversion function templates; they don't tell us anything 4312 // about which builtin types we can convert to. 4313 if (isa<FunctionTemplateDecl>(D)) 4314 continue; 4315 4316 CXXConversionDecl *Conv = cast<CXXConversionDecl>(D); 4317 if (AllowExplicitConversions || !Conv->isExplicit()) { 4318 AddTypesConvertedFrom(Conv->getConversionType(), Loc, false, false, 4319 VisibleQuals); 4320 } 4321 } 4322 } 4323 } 4324} 4325 4326/// \brief Helper function for AddBuiltinOperatorCandidates() that adds 4327/// the volatile- and non-volatile-qualified assignment operators for the 4328/// given type to the candidate set. 4329static void AddBuiltinAssignmentOperatorCandidates(Sema &S, 4330 QualType T, 4331 Expr **Args, 4332 unsigned NumArgs, 4333 OverloadCandidateSet &CandidateSet) { 4334 QualType ParamTypes[2]; 4335 4336 // T& operator=(T&, T) 4337 ParamTypes[0] = S.Context.getLValueReferenceType(T); 4338 ParamTypes[1] = T; 4339 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4340 /*IsAssignmentOperator=*/true); 4341 4342 if (!S.Context.getCanonicalType(T).isVolatileQualified()) { 4343 // volatile T& operator=(volatile T&, T) 4344 ParamTypes[0] 4345 = S.Context.getLValueReferenceType(S.Context.getVolatileType(T)); 4346 ParamTypes[1] = T; 4347 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4348 /*IsAssignmentOperator=*/true); 4349 } 4350} 4351 4352/// CollectVRQualifiers - This routine returns Volatile/Restrict qualifiers, 4353/// if any, found in visible type conversion functions found in ArgExpr's type. 4354static Qualifiers CollectVRQualifiers(ASTContext &Context, Expr* ArgExpr) { 4355 Qualifiers VRQuals; 4356 const RecordType *TyRec; 4357 if (const MemberPointerType *RHSMPType = 4358 ArgExpr->getType()->getAs<MemberPointerType>()) 4359 TyRec = RHSMPType->getClass()->getAs<RecordType>(); 4360 else 4361 TyRec = ArgExpr->getType()->getAs<RecordType>(); 4362 if (!TyRec) { 4363 // Just to be safe, assume the worst case. 4364 VRQuals.addVolatile(); 4365 VRQuals.addRestrict(); 4366 return VRQuals; 4367 } 4368 4369 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 4370 if (!ClassDecl->hasDefinition()) 4371 return VRQuals; 4372 4373 const UnresolvedSetImpl *Conversions = 4374 ClassDecl->getVisibleConversionFunctions(); 4375 4376 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 4377 E = Conversions->end(); I != E; ++I) { 4378 NamedDecl *D = I.getDecl(); 4379 if (isa<UsingShadowDecl>(D)) 4380 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 4381 if (CXXConversionDecl *Conv = dyn_cast<CXXConversionDecl>(D)) { 4382 QualType CanTy = Context.getCanonicalType(Conv->getConversionType()); 4383 if (const ReferenceType *ResTypeRef = CanTy->getAs<ReferenceType>()) 4384 CanTy = ResTypeRef->getPointeeType(); 4385 // Need to go down the pointer/mempointer chain and add qualifiers 4386 // as see them. 4387 bool done = false; 4388 while (!done) { 4389 if (const PointerType *ResTypePtr = CanTy->getAs<PointerType>()) 4390 CanTy = ResTypePtr->getPointeeType(); 4391 else if (const MemberPointerType *ResTypeMPtr = 4392 CanTy->getAs<MemberPointerType>()) 4393 CanTy = ResTypeMPtr->getPointeeType(); 4394 else 4395 done = true; 4396 if (CanTy.isVolatileQualified()) 4397 VRQuals.addVolatile(); 4398 if (CanTy.isRestrictQualified()) 4399 VRQuals.addRestrict(); 4400 if (VRQuals.hasRestrict() && VRQuals.hasVolatile()) 4401 return VRQuals; 4402 } 4403 } 4404 } 4405 return VRQuals; 4406} 4407 4408/// AddBuiltinOperatorCandidates - Add the appropriate built-in 4409/// operator overloads to the candidate set (C++ [over.built]), based 4410/// on the operator @p Op and the arguments given. For example, if the 4411/// operator is a binary '+', this routine might add "int 4412/// operator+(int, int)" to cover integer addition. 4413void 4414Sema::AddBuiltinOperatorCandidates(OverloadedOperatorKind Op, 4415 SourceLocation OpLoc, 4416 Expr **Args, unsigned NumArgs, 4417 OverloadCandidateSet& CandidateSet) { 4418 // The set of "promoted arithmetic types", which are the arithmetic 4419 // types are that preserved by promotion (C++ [over.built]p2). Note 4420 // that the first few of these types are the promoted integral 4421 // types; these types need to be first. 4422 // FIXME: What about complex? 4423 const unsigned FirstIntegralType = 0; 4424 const unsigned LastIntegralType = 13; 4425 const unsigned FirstPromotedIntegralType = 7, 4426 LastPromotedIntegralType = 13; 4427 const unsigned FirstPromotedArithmeticType = 7, 4428 LastPromotedArithmeticType = 16; 4429 const unsigned NumArithmeticTypes = 16; 4430 QualType ArithmeticTypes[NumArithmeticTypes] = { 4431 Context.BoolTy, Context.CharTy, Context.WCharTy, 4432// FIXME: Context.Char16Ty, Context.Char32Ty, 4433 Context.SignedCharTy, Context.ShortTy, 4434 Context.UnsignedCharTy, Context.UnsignedShortTy, 4435 Context.IntTy, Context.LongTy, Context.LongLongTy, 4436 Context.UnsignedIntTy, Context.UnsignedLongTy, Context.UnsignedLongLongTy, 4437 Context.FloatTy, Context.DoubleTy, Context.LongDoubleTy 4438 }; 4439 assert(ArithmeticTypes[FirstPromotedIntegralType] == Context.IntTy && 4440 "Invalid first promoted integral type"); 4441 assert(ArithmeticTypes[LastPromotedIntegralType - 1] 4442 == Context.UnsignedLongLongTy && 4443 "Invalid last promoted integral type"); 4444 assert(ArithmeticTypes[FirstPromotedArithmeticType] == Context.IntTy && 4445 "Invalid first promoted arithmetic type"); 4446 assert(ArithmeticTypes[LastPromotedArithmeticType - 1] 4447 == Context.LongDoubleTy && 4448 "Invalid last promoted arithmetic type"); 4449 4450 // Find all of the types that the arguments can convert to, but only 4451 // if the operator we're looking at has built-in operator candidates 4452 // that make use of these types. 4453 Qualifiers VisibleTypeConversionsQuals; 4454 VisibleTypeConversionsQuals.addConst(); 4455 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 4456 VisibleTypeConversionsQuals += CollectVRQualifiers(Context, Args[ArgIdx]); 4457 4458 BuiltinCandidateTypeSet CandidateTypes(*this); 4459 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 4460 CandidateTypes.AddTypesConvertedFrom(Args[ArgIdx]->getType(), 4461 OpLoc, 4462 true, 4463 (Op == OO_Exclaim || 4464 Op == OO_AmpAmp || 4465 Op == OO_PipePipe), 4466 VisibleTypeConversionsQuals); 4467 4468 bool isComparison = false; 4469 switch (Op) { 4470 case OO_None: 4471 case NUM_OVERLOADED_OPERATORS: 4472 assert(false && "Expected an overloaded operator"); 4473 break; 4474 4475 case OO_Star: // '*' is either unary or binary 4476 if (NumArgs == 1) 4477 goto UnaryStar; 4478 else 4479 goto BinaryStar; 4480 break; 4481 4482 case OO_Plus: // '+' is either unary or binary 4483 if (NumArgs == 1) 4484 goto UnaryPlus; 4485 else 4486 goto BinaryPlus; 4487 break; 4488 4489 case OO_Minus: // '-' is either unary or binary 4490 if (NumArgs == 1) 4491 goto UnaryMinus; 4492 else 4493 goto BinaryMinus; 4494 break; 4495 4496 case OO_Amp: // '&' is either unary or binary 4497 if (NumArgs == 1) 4498 goto UnaryAmp; 4499 else 4500 goto BinaryAmp; 4501 4502 case OO_PlusPlus: 4503 case OO_MinusMinus: 4504 // C++ [over.built]p3: 4505 // 4506 // For every pair (T, VQ), where T is an arithmetic type, and VQ 4507 // is either volatile or empty, there exist candidate operator 4508 // functions of the form 4509 // 4510 // VQ T& operator++(VQ T&); 4511 // T operator++(VQ T&, int); 4512 // 4513 // C++ [over.built]p4: 4514 // 4515 // For every pair (T, VQ), where T is an arithmetic type other 4516 // than bool, and VQ is either volatile or empty, there exist 4517 // candidate operator functions of the form 4518 // 4519 // VQ T& operator--(VQ T&); 4520 // T operator--(VQ T&, int); 4521 for (unsigned Arith = (Op == OO_PlusPlus? 0 : 1); 4522 Arith < NumArithmeticTypes; ++Arith) { 4523 QualType ArithTy = ArithmeticTypes[Arith]; 4524 QualType ParamTypes[2] 4525 = { Context.getLValueReferenceType(ArithTy), Context.IntTy }; 4526 4527 // Non-volatile version. 4528 if (NumArgs == 1) 4529 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 4530 else 4531 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 4532 // heuristic to reduce number of builtin candidates in the set. 4533 // Add volatile version only if there are conversions to a volatile type. 4534 if (VisibleTypeConversionsQuals.hasVolatile()) { 4535 // Volatile version 4536 ParamTypes[0] 4537 = Context.getLValueReferenceType(Context.getVolatileType(ArithTy)); 4538 if (NumArgs == 1) 4539 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 4540 else 4541 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 4542 } 4543 } 4544 4545 // C++ [over.built]p5: 4546 // 4547 // For every pair (T, VQ), where T is a cv-qualified or 4548 // cv-unqualified object type, and VQ is either volatile or 4549 // empty, there exist candidate operator functions of the form 4550 // 4551 // T*VQ& operator++(T*VQ&); 4552 // T*VQ& operator--(T*VQ&); 4553 // T* operator++(T*VQ&, int); 4554 // T* operator--(T*VQ&, int); 4555 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 4556 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4557 // Skip pointer types that aren't pointers to object types. 4558 if (!(*Ptr)->getPointeeType()->isIncompleteOrObjectType()) 4559 continue; 4560 4561 QualType ParamTypes[2] = { 4562 Context.getLValueReferenceType(*Ptr), Context.IntTy 4563 }; 4564 4565 // Without volatile 4566 if (NumArgs == 1) 4567 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 4568 else 4569 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 4570 4571 if (!Context.getCanonicalType(*Ptr).isVolatileQualified() && 4572 VisibleTypeConversionsQuals.hasVolatile()) { 4573 // With volatile 4574 ParamTypes[0] 4575 = Context.getLValueReferenceType(Context.getVolatileType(*Ptr)); 4576 if (NumArgs == 1) 4577 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 4578 else 4579 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 4580 } 4581 } 4582 break; 4583 4584 UnaryStar: 4585 // C++ [over.built]p6: 4586 // For every cv-qualified or cv-unqualified object type T, there 4587 // exist candidate operator functions of the form 4588 // 4589 // T& operator*(T*); 4590 // 4591 // C++ [over.built]p7: 4592 // For every function type T, there exist candidate operator 4593 // functions of the form 4594 // T& operator*(T*); 4595 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 4596 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4597 QualType ParamTy = *Ptr; 4598 QualType PointeeTy = ParamTy->getPointeeType(); 4599 AddBuiltinCandidate(Context.getLValueReferenceType(PointeeTy), 4600 &ParamTy, Args, 1, CandidateSet); 4601 } 4602 break; 4603 4604 UnaryPlus: 4605 // C++ [over.built]p8: 4606 // For every type T, there exist candidate operator functions of 4607 // the form 4608 // 4609 // T* operator+(T*); 4610 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 4611 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4612 QualType ParamTy = *Ptr; 4613 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet); 4614 } 4615 4616 // Fall through 4617 4618 UnaryMinus: 4619 // C++ [over.built]p9: 4620 // For every promoted arithmetic type T, there exist candidate 4621 // operator functions of the form 4622 // 4623 // T operator+(T); 4624 // T operator-(T); 4625 for (unsigned Arith = FirstPromotedArithmeticType; 4626 Arith < LastPromotedArithmeticType; ++Arith) { 4627 QualType ArithTy = ArithmeticTypes[Arith]; 4628 AddBuiltinCandidate(ArithTy, &ArithTy, Args, 1, CandidateSet); 4629 } 4630 4631 // Extension: We also add these operators for vector types. 4632 for (BuiltinCandidateTypeSet::iterator Vec = CandidateTypes.vector_begin(), 4633 VecEnd = CandidateTypes.vector_end(); 4634 Vec != VecEnd; ++Vec) { 4635 QualType VecTy = *Vec; 4636 AddBuiltinCandidate(VecTy, &VecTy, Args, 1, CandidateSet); 4637 } 4638 break; 4639 4640 case OO_Tilde: 4641 // C++ [over.built]p10: 4642 // For every promoted integral type T, there exist candidate 4643 // operator functions of the form 4644 // 4645 // T operator~(T); 4646 for (unsigned Int = FirstPromotedIntegralType; 4647 Int < LastPromotedIntegralType; ++Int) { 4648 QualType IntTy = ArithmeticTypes[Int]; 4649 AddBuiltinCandidate(IntTy, &IntTy, Args, 1, CandidateSet); 4650 } 4651 4652 // Extension: We also add this operator for vector types. 4653 for (BuiltinCandidateTypeSet::iterator Vec = CandidateTypes.vector_begin(), 4654 VecEnd = CandidateTypes.vector_end(); 4655 Vec != VecEnd; ++Vec) { 4656 QualType VecTy = *Vec; 4657 AddBuiltinCandidate(VecTy, &VecTy, Args, 1, CandidateSet); 4658 } 4659 break; 4660 4661 case OO_New: 4662 case OO_Delete: 4663 case OO_Array_New: 4664 case OO_Array_Delete: 4665 case OO_Call: 4666 assert(false && "Special operators don't use AddBuiltinOperatorCandidates"); 4667 break; 4668 4669 case OO_Comma: 4670 UnaryAmp: 4671 case OO_Arrow: 4672 // C++ [over.match.oper]p3: 4673 // -- For the operator ',', the unary operator '&', or the 4674 // operator '->', the built-in candidates set is empty. 4675 break; 4676 4677 case OO_EqualEqual: 4678 case OO_ExclaimEqual: 4679 // C++ [over.match.oper]p16: 4680 // For every pointer to member type T, there exist candidate operator 4681 // functions of the form 4682 // 4683 // bool operator==(T,T); 4684 // bool operator!=(T,T); 4685 for (BuiltinCandidateTypeSet::iterator 4686 MemPtr = CandidateTypes.member_pointer_begin(), 4687 MemPtrEnd = CandidateTypes.member_pointer_end(); 4688 MemPtr != MemPtrEnd; 4689 ++MemPtr) { 4690 QualType ParamTypes[2] = { *MemPtr, *MemPtr }; 4691 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 4692 } 4693 4694 // Fall through 4695 4696 case OO_Less: 4697 case OO_Greater: 4698 case OO_LessEqual: 4699 case OO_GreaterEqual: 4700 // C++ [over.built]p15: 4701 // 4702 // For every pointer or enumeration type T, there exist 4703 // candidate operator functions of the form 4704 // 4705 // bool operator<(T, T); 4706 // bool operator>(T, T); 4707 // bool operator<=(T, T); 4708 // bool operator>=(T, T); 4709 // bool operator==(T, T); 4710 // bool operator!=(T, T); 4711 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 4712 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4713 QualType ParamTypes[2] = { *Ptr, *Ptr }; 4714 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 4715 } 4716 for (BuiltinCandidateTypeSet::iterator Enum 4717 = CandidateTypes.enumeration_begin(); 4718 Enum != CandidateTypes.enumeration_end(); ++Enum) { 4719 QualType ParamTypes[2] = { *Enum, *Enum }; 4720 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 4721 } 4722 4723 // Fall through. 4724 isComparison = true; 4725 4726 BinaryPlus: 4727 BinaryMinus: 4728 if (!isComparison) { 4729 // We didn't fall through, so we must have OO_Plus or OO_Minus. 4730 4731 // C++ [over.built]p13: 4732 // 4733 // For every cv-qualified or cv-unqualified object type T 4734 // there exist candidate operator functions of the form 4735 // 4736 // T* operator+(T*, ptrdiff_t); 4737 // T& operator[](T*, ptrdiff_t); [BELOW] 4738 // T* operator-(T*, ptrdiff_t); 4739 // T* operator+(ptrdiff_t, T*); 4740 // T& operator[](ptrdiff_t, T*); [BELOW] 4741 // 4742 // C++ [over.built]p14: 4743 // 4744 // For every T, where T is a pointer to object type, there 4745 // exist candidate operator functions of the form 4746 // 4747 // ptrdiff_t operator-(T, T); 4748 for (BuiltinCandidateTypeSet::iterator Ptr 4749 = CandidateTypes.pointer_begin(); 4750 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4751 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 4752 4753 // operator+(T*, ptrdiff_t) or operator-(T*, ptrdiff_t) 4754 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 4755 4756 if (Op == OO_Plus) { 4757 // T* operator+(ptrdiff_t, T*); 4758 ParamTypes[0] = ParamTypes[1]; 4759 ParamTypes[1] = *Ptr; 4760 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 4761 } else { 4762 // ptrdiff_t operator-(T, T); 4763 ParamTypes[1] = *Ptr; 4764 AddBuiltinCandidate(Context.getPointerDiffType(), ParamTypes, 4765 Args, 2, CandidateSet); 4766 } 4767 } 4768 } 4769 // Fall through 4770 4771 case OO_Slash: 4772 BinaryStar: 4773 Conditional: 4774 // C++ [over.built]p12: 4775 // 4776 // For every pair of promoted arithmetic types L and R, there 4777 // exist candidate operator functions of the form 4778 // 4779 // LR operator*(L, R); 4780 // LR operator/(L, R); 4781 // LR operator+(L, R); 4782 // LR operator-(L, R); 4783 // bool operator<(L, R); 4784 // bool operator>(L, R); 4785 // bool operator<=(L, R); 4786 // bool operator>=(L, R); 4787 // bool operator==(L, R); 4788 // bool operator!=(L, R); 4789 // 4790 // where LR is the result of the usual arithmetic conversions 4791 // between types L and R. 4792 // 4793 // C++ [over.built]p24: 4794 // 4795 // For every pair of promoted arithmetic types L and R, there exist 4796 // candidate operator functions of the form 4797 // 4798 // LR operator?(bool, L, R); 4799 // 4800 // where LR is the result of the usual arithmetic conversions 4801 // between types L and R. 4802 // Our candidates ignore the first parameter. 4803 for (unsigned Left = FirstPromotedArithmeticType; 4804 Left < LastPromotedArithmeticType; ++Left) { 4805 for (unsigned Right = FirstPromotedArithmeticType; 4806 Right < LastPromotedArithmeticType; ++Right) { 4807 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 4808 QualType Result 4809 = isComparison 4810 ? Context.BoolTy 4811 : Context.UsualArithmeticConversionsType(LandR[0], LandR[1]); 4812 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 4813 } 4814 } 4815 4816 // Extension: Add the binary operators ==, !=, <, <=, >=, >, *, /, and the 4817 // conditional operator for vector types. 4818 for (BuiltinCandidateTypeSet::iterator Vec1 = CandidateTypes.vector_begin(), 4819 Vec1End = CandidateTypes.vector_end(); 4820 Vec1 != Vec1End; ++Vec1) 4821 for (BuiltinCandidateTypeSet::iterator 4822 Vec2 = CandidateTypes.vector_begin(), 4823 Vec2End = CandidateTypes.vector_end(); 4824 Vec2 != Vec2End; ++Vec2) { 4825 QualType LandR[2] = { *Vec1, *Vec2 }; 4826 QualType Result; 4827 if (isComparison) 4828 Result = Context.BoolTy; 4829 else { 4830 if ((*Vec1)->isExtVectorType() || !(*Vec2)->isExtVectorType()) 4831 Result = *Vec1; 4832 else 4833 Result = *Vec2; 4834 } 4835 4836 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 4837 } 4838 4839 break; 4840 4841 case OO_Percent: 4842 BinaryAmp: 4843 case OO_Caret: 4844 case OO_Pipe: 4845 case OO_LessLess: 4846 case OO_GreaterGreater: 4847 // C++ [over.built]p17: 4848 // 4849 // For every pair of promoted integral types L and R, there 4850 // exist candidate operator functions of the form 4851 // 4852 // LR operator%(L, R); 4853 // LR operator&(L, R); 4854 // LR operator^(L, R); 4855 // LR operator|(L, R); 4856 // L operator<<(L, R); 4857 // L operator>>(L, R); 4858 // 4859 // where LR is the result of the usual arithmetic conversions 4860 // between types L and R. 4861 for (unsigned Left = FirstPromotedIntegralType; 4862 Left < LastPromotedIntegralType; ++Left) { 4863 for (unsigned Right = FirstPromotedIntegralType; 4864 Right < LastPromotedIntegralType; ++Right) { 4865 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 4866 QualType Result = (Op == OO_LessLess || Op == OO_GreaterGreater) 4867 ? LandR[0] 4868 : Context.UsualArithmeticConversionsType(LandR[0], LandR[1]); 4869 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 4870 } 4871 } 4872 break; 4873 4874 case OO_Equal: 4875 // C++ [over.built]p20: 4876 // 4877 // For every pair (T, VQ), where T is an enumeration or 4878 // pointer to member type and VQ is either volatile or 4879 // empty, there exist candidate operator functions of the form 4880 // 4881 // VQ T& operator=(VQ T&, T); 4882 for (BuiltinCandidateTypeSet::iterator 4883 Enum = CandidateTypes.enumeration_begin(), 4884 EnumEnd = CandidateTypes.enumeration_end(); 4885 Enum != EnumEnd; ++Enum) 4886 AddBuiltinAssignmentOperatorCandidates(*this, *Enum, Args, 2, 4887 CandidateSet); 4888 for (BuiltinCandidateTypeSet::iterator 4889 MemPtr = CandidateTypes.member_pointer_begin(), 4890 MemPtrEnd = CandidateTypes.member_pointer_end(); 4891 MemPtr != MemPtrEnd; ++MemPtr) 4892 AddBuiltinAssignmentOperatorCandidates(*this, *MemPtr, Args, 2, 4893 CandidateSet); 4894 4895 // Fall through. 4896 4897 case OO_PlusEqual: 4898 case OO_MinusEqual: 4899 // C++ [over.built]p19: 4900 // 4901 // For every pair (T, VQ), where T is any type and VQ is either 4902 // volatile or empty, there exist candidate operator functions 4903 // of the form 4904 // 4905 // T*VQ& operator=(T*VQ&, T*); 4906 // 4907 // C++ [over.built]p21: 4908 // 4909 // For every pair (T, VQ), where T is a cv-qualified or 4910 // cv-unqualified object type and VQ is either volatile or 4911 // empty, there exist candidate operator functions of the form 4912 // 4913 // T*VQ& operator+=(T*VQ&, ptrdiff_t); 4914 // T*VQ& operator-=(T*VQ&, ptrdiff_t); 4915 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 4916 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4917 QualType ParamTypes[2]; 4918 ParamTypes[1] = (Op == OO_Equal)? *Ptr : Context.getPointerDiffType(); 4919 4920 // non-volatile version 4921 ParamTypes[0] = Context.getLValueReferenceType(*Ptr); 4922 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4923 /*IsAssigmentOperator=*/Op == OO_Equal); 4924 4925 if (!Context.getCanonicalType(*Ptr).isVolatileQualified() && 4926 VisibleTypeConversionsQuals.hasVolatile()) { 4927 // volatile version 4928 ParamTypes[0] 4929 = Context.getLValueReferenceType(Context.getVolatileType(*Ptr)); 4930 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4931 /*IsAssigmentOperator=*/Op == OO_Equal); 4932 } 4933 } 4934 // Fall through. 4935 4936 case OO_StarEqual: 4937 case OO_SlashEqual: 4938 // C++ [over.built]p18: 4939 // 4940 // For every triple (L, VQ, R), where L is an arithmetic type, 4941 // VQ is either volatile or empty, and R is a promoted 4942 // arithmetic type, there exist candidate operator functions of 4943 // the form 4944 // 4945 // VQ L& operator=(VQ L&, R); 4946 // VQ L& operator*=(VQ L&, R); 4947 // VQ L& operator/=(VQ L&, R); 4948 // VQ L& operator+=(VQ L&, R); 4949 // VQ L& operator-=(VQ L&, R); 4950 for (unsigned Left = 0; Left < NumArithmeticTypes; ++Left) { 4951 for (unsigned Right = FirstPromotedArithmeticType; 4952 Right < LastPromotedArithmeticType; ++Right) { 4953 QualType ParamTypes[2]; 4954 ParamTypes[1] = ArithmeticTypes[Right]; 4955 4956 // Add this built-in operator as a candidate (VQ is empty). 4957 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 4958 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4959 /*IsAssigmentOperator=*/Op == OO_Equal); 4960 4961 // Add this built-in operator as a candidate (VQ is 'volatile'). 4962 if (VisibleTypeConversionsQuals.hasVolatile()) { 4963 ParamTypes[0] = Context.getVolatileType(ArithmeticTypes[Left]); 4964 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 4965 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4966 /*IsAssigmentOperator=*/Op == OO_Equal); 4967 } 4968 } 4969 } 4970 4971 // Extension: Add the binary operators =, +=, -=, *=, /= for vector types. 4972 for (BuiltinCandidateTypeSet::iterator Vec1 = CandidateTypes.vector_begin(), 4973 Vec1End = CandidateTypes.vector_end(); 4974 Vec1 != Vec1End; ++Vec1) 4975 for (BuiltinCandidateTypeSet::iterator 4976 Vec2 = CandidateTypes.vector_begin(), 4977 Vec2End = CandidateTypes.vector_end(); 4978 Vec2 != Vec2End; ++Vec2) { 4979 QualType ParamTypes[2]; 4980 ParamTypes[1] = *Vec2; 4981 // Add this built-in operator as a candidate (VQ is empty). 4982 ParamTypes[0] = Context.getLValueReferenceType(*Vec1); 4983 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4984 /*IsAssigmentOperator=*/Op == OO_Equal); 4985 4986 // Add this built-in operator as a candidate (VQ is 'volatile'). 4987 if (VisibleTypeConversionsQuals.hasVolatile()) { 4988 ParamTypes[0] = Context.getVolatileType(*Vec1); 4989 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 4990 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4991 /*IsAssigmentOperator=*/Op == OO_Equal); 4992 } 4993 } 4994 break; 4995 4996 case OO_PercentEqual: 4997 case OO_LessLessEqual: 4998 case OO_GreaterGreaterEqual: 4999 case OO_AmpEqual: 5000 case OO_CaretEqual: 5001 case OO_PipeEqual: 5002 // C++ [over.built]p22: 5003 // 5004 // For every triple (L, VQ, R), where L is an integral type, VQ 5005 // is either volatile or empty, and R is a promoted integral 5006 // type, there exist candidate operator functions of the form 5007 // 5008 // VQ L& operator%=(VQ L&, R); 5009 // VQ L& operator<<=(VQ L&, R); 5010 // VQ L& operator>>=(VQ L&, R); 5011 // VQ L& operator&=(VQ L&, R); 5012 // VQ L& operator^=(VQ L&, R); 5013 // VQ L& operator|=(VQ L&, R); 5014 for (unsigned Left = FirstIntegralType; Left < LastIntegralType; ++Left) { 5015 for (unsigned Right = FirstPromotedIntegralType; 5016 Right < LastPromotedIntegralType; ++Right) { 5017 QualType ParamTypes[2]; 5018 ParamTypes[1] = ArithmeticTypes[Right]; 5019 5020 // Add this built-in operator as a candidate (VQ is empty). 5021 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 5022 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 5023 if (VisibleTypeConversionsQuals.hasVolatile()) { 5024 // Add this built-in operator as a candidate (VQ is 'volatile'). 5025 ParamTypes[0] = ArithmeticTypes[Left]; 5026 ParamTypes[0] = Context.getVolatileType(ParamTypes[0]); 5027 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 5028 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 5029 } 5030 } 5031 } 5032 break; 5033 5034 case OO_Exclaim: { 5035 // C++ [over.operator]p23: 5036 // 5037 // There also exist candidate operator functions of the form 5038 // 5039 // bool operator!(bool); 5040 // bool operator&&(bool, bool); [BELOW] 5041 // bool operator||(bool, bool); [BELOW] 5042 QualType ParamTy = Context.BoolTy; 5043 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet, 5044 /*IsAssignmentOperator=*/false, 5045 /*NumContextualBoolArguments=*/1); 5046 break; 5047 } 5048 5049 case OO_AmpAmp: 5050 case OO_PipePipe: { 5051 // C++ [over.operator]p23: 5052 // 5053 // There also exist candidate operator functions of the form 5054 // 5055 // bool operator!(bool); [ABOVE] 5056 // bool operator&&(bool, bool); 5057 // bool operator||(bool, bool); 5058 QualType ParamTypes[2] = { Context.BoolTy, Context.BoolTy }; 5059 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet, 5060 /*IsAssignmentOperator=*/false, 5061 /*NumContextualBoolArguments=*/2); 5062 break; 5063 } 5064 5065 case OO_Subscript: 5066 // C++ [over.built]p13: 5067 // 5068 // For every cv-qualified or cv-unqualified object type T there 5069 // exist candidate operator functions of the form 5070 // 5071 // T* operator+(T*, ptrdiff_t); [ABOVE] 5072 // T& operator[](T*, ptrdiff_t); 5073 // T* operator-(T*, ptrdiff_t); [ABOVE] 5074 // T* operator+(ptrdiff_t, T*); [ABOVE] 5075 // T& operator[](ptrdiff_t, T*); 5076 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 5077 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 5078 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 5079 QualType PointeeType = (*Ptr)->getPointeeType(); 5080 QualType ResultTy = Context.getLValueReferenceType(PointeeType); 5081 5082 // T& operator[](T*, ptrdiff_t) 5083 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 5084 5085 // T& operator[](ptrdiff_t, T*); 5086 ParamTypes[0] = ParamTypes[1]; 5087 ParamTypes[1] = *Ptr; 5088 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 5089 } 5090 break; 5091 5092 case OO_ArrowStar: 5093 // C++ [over.built]p11: 5094 // For every quintuple (C1, C2, T, CV1, CV2), where C2 is a class type, 5095 // C1 is the same type as C2 or is a derived class of C2, T is an object 5096 // type or a function type, and CV1 and CV2 are cv-qualifier-seqs, 5097 // there exist candidate operator functions of the form 5098 // CV12 T& operator->*(CV1 C1*, CV2 T C2::*); 5099 // where CV12 is the union of CV1 and CV2. 5100 { 5101 for (BuiltinCandidateTypeSet::iterator Ptr = 5102 CandidateTypes.pointer_begin(); 5103 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 5104 QualType C1Ty = (*Ptr); 5105 QualType C1; 5106 QualifierCollector Q1; 5107 C1 = QualType(Q1.strip(C1Ty->getPointeeType()), 0); 5108 if (!isa<RecordType>(C1)) 5109 continue; 5110 // heuristic to reduce number of builtin candidates in the set. 5111 // Add volatile/restrict version only if there are conversions to a 5112 // volatile/restrict type. 5113 if (!VisibleTypeConversionsQuals.hasVolatile() && Q1.hasVolatile()) 5114 continue; 5115 if (!VisibleTypeConversionsQuals.hasRestrict() && Q1.hasRestrict()) 5116 continue; 5117 for (BuiltinCandidateTypeSet::iterator 5118 MemPtr = CandidateTypes.member_pointer_begin(), 5119 MemPtrEnd = CandidateTypes.member_pointer_end(); 5120 MemPtr != MemPtrEnd; ++MemPtr) { 5121 const MemberPointerType *mptr = cast<MemberPointerType>(*MemPtr); 5122 QualType C2 = QualType(mptr->getClass(), 0); 5123 C2 = C2.getUnqualifiedType(); 5124 if (C1 != C2 && !IsDerivedFrom(C1, C2)) 5125 break; 5126 QualType ParamTypes[2] = { *Ptr, *MemPtr }; 5127 // build CV12 T& 5128 QualType T = mptr->getPointeeType(); 5129 if (!VisibleTypeConversionsQuals.hasVolatile() && 5130 T.isVolatileQualified()) 5131 continue; 5132 if (!VisibleTypeConversionsQuals.hasRestrict() && 5133 T.isRestrictQualified()) 5134 continue; 5135 T = Q1.apply(T); 5136 QualType ResultTy = Context.getLValueReferenceType(T); 5137 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 5138 } 5139 } 5140 } 5141 break; 5142 5143 case OO_Conditional: 5144 // Note that we don't consider the first argument, since it has been 5145 // contextually converted to bool long ago. The candidates below are 5146 // therefore added as binary. 5147 // 5148 // C++ [over.built]p24: 5149 // For every type T, where T is a pointer or pointer-to-member type, 5150 // there exist candidate operator functions of the form 5151 // 5152 // T operator?(bool, T, T); 5153 // 5154 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(), 5155 E = CandidateTypes.pointer_end(); Ptr != E; ++Ptr) { 5156 QualType ParamTypes[2] = { *Ptr, *Ptr }; 5157 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 5158 } 5159 for (BuiltinCandidateTypeSet::iterator Ptr = 5160 CandidateTypes.member_pointer_begin(), 5161 E = CandidateTypes.member_pointer_end(); Ptr != E; ++Ptr) { 5162 QualType ParamTypes[2] = { *Ptr, *Ptr }; 5163 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 5164 } 5165 goto Conditional; 5166 } 5167} 5168 5169/// \brief Add function candidates found via argument-dependent lookup 5170/// to the set of overloading candidates. 5171/// 5172/// This routine performs argument-dependent name lookup based on the 5173/// given function name (which may also be an operator name) and adds 5174/// all of the overload candidates found by ADL to the overload 5175/// candidate set (C++ [basic.lookup.argdep]). 5176void 5177Sema::AddArgumentDependentLookupCandidates(DeclarationName Name, 5178 bool Operator, 5179 Expr **Args, unsigned NumArgs, 5180 const TemplateArgumentListInfo *ExplicitTemplateArgs, 5181 OverloadCandidateSet& CandidateSet, 5182 bool PartialOverloading) { 5183 ADLResult Fns; 5184 5185 // FIXME: This approach for uniquing ADL results (and removing 5186 // redundant candidates from the set) relies on pointer-equality, 5187 // which means we need to key off the canonical decl. However, 5188 // always going back to the canonical decl might not get us the 5189 // right set of default arguments. What default arguments are 5190 // we supposed to consider on ADL candidates, anyway? 5191 5192 // FIXME: Pass in the explicit template arguments? 5193 ArgumentDependentLookup(Name, Operator, Args, NumArgs, Fns); 5194 5195 // Erase all of the candidates we already knew about. 5196 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 5197 CandEnd = CandidateSet.end(); 5198 Cand != CandEnd; ++Cand) 5199 if (Cand->Function) { 5200 Fns.erase(Cand->Function); 5201 if (FunctionTemplateDecl *FunTmpl = Cand->Function->getPrimaryTemplate()) 5202 Fns.erase(FunTmpl); 5203 } 5204 5205 // For each of the ADL candidates we found, add it to the overload 5206 // set. 5207 for (ADLResult::iterator I = Fns.begin(), E = Fns.end(); I != E; ++I) { 5208 DeclAccessPair FoundDecl = DeclAccessPair::make(*I, AS_none); 5209 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*I)) { 5210 if (ExplicitTemplateArgs) 5211 continue; 5212 5213 AddOverloadCandidate(FD, FoundDecl, Args, NumArgs, CandidateSet, 5214 false, PartialOverloading); 5215 } else 5216 AddTemplateOverloadCandidate(cast<FunctionTemplateDecl>(*I), 5217 FoundDecl, ExplicitTemplateArgs, 5218 Args, NumArgs, CandidateSet); 5219 } 5220} 5221 5222/// isBetterOverloadCandidate - Determines whether the first overload 5223/// candidate is a better candidate than the second (C++ 13.3.3p1). 5224bool 5225Sema::isBetterOverloadCandidate(const OverloadCandidate& Cand1, 5226 const OverloadCandidate& Cand2, 5227 SourceLocation Loc) { 5228 // Define viable functions to be better candidates than non-viable 5229 // functions. 5230 if (!Cand2.Viable) 5231 return Cand1.Viable; 5232 else if (!Cand1.Viable) 5233 return false; 5234 5235 // C++ [over.match.best]p1: 5236 // 5237 // -- if F is a static member function, ICS1(F) is defined such 5238 // that ICS1(F) is neither better nor worse than ICS1(G) for 5239 // any function G, and, symmetrically, ICS1(G) is neither 5240 // better nor worse than ICS1(F). 5241 unsigned StartArg = 0; 5242 if (Cand1.IgnoreObjectArgument || Cand2.IgnoreObjectArgument) 5243 StartArg = 1; 5244 5245 // C++ [over.match.best]p1: 5246 // A viable function F1 is defined to be a better function than another 5247 // viable function F2 if for all arguments i, ICSi(F1) is not a worse 5248 // conversion sequence than ICSi(F2), and then... 5249 unsigned NumArgs = Cand1.Conversions.size(); 5250 assert(Cand2.Conversions.size() == NumArgs && "Overload candidate mismatch"); 5251 bool HasBetterConversion = false; 5252 for (unsigned ArgIdx = StartArg; ArgIdx < NumArgs; ++ArgIdx) { 5253 switch (CompareImplicitConversionSequences(Cand1.Conversions[ArgIdx], 5254 Cand2.Conversions[ArgIdx])) { 5255 case ImplicitConversionSequence::Better: 5256 // Cand1 has a better conversion sequence. 5257 HasBetterConversion = true; 5258 break; 5259 5260 case ImplicitConversionSequence::Worse: 5261 // Cand1 can't be better than Cand2. 5262 return false; 5263 5264 case ImplicitConversionSequence::Indistinguishable: 5265 // Do nothing. 5266 break; 5267 } 5268 } 5269 5270 // -- for some argument j, ICSj(F1) is a better conversion sequence than 5271 // ICSj(F2), or, if not that, 5272 if (HasBetterConversion) 5273 return true; 5274 5275 // - F1 is a non-template function and F2 is a function template 5276 // specialization, or, if not that, 5277 if ((!Cand1.Function || !Cand1.Function->getPrimaryTemplate()) && 5278 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 5279 return true; 5280 5281 // -- F1 and F2 are function template specializations, and the function 5282 // template for F1 is more specialized than the template for F2 5283 // according to the partial ordering rules described in 14.5.5.2, or, 5284 // if not that, 5285 if (Cand1.Function && Cand1.Function->getPrimaryTemplate() && 5286 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 5287 if (FunctionTemplateDecl *BetterTemplate 5288 = getMoreSpecializedTemplate(Cand1.Function->getPrimaryTemplate(), 5289 Cand2.Function->getPrimaryTemplate(), 5290 Loc, 5291 isa<CXXConversionDecl>(Cand1.Function)? TPOC_Conversion 5292 : TPOC_Call)) 5293 return BetterTemplate == Cand1.Function->getPrimaryTemplate(); 5294 5295 // -- the context is an initialization by user-defined conversion 5296 // (see 8.5, 13.3.1.5) and the standard conversion sequence 5297 // from the return type of F1 to the destination type (i.e., 5298 // the type of the entity being initialized) is a better 5299 // conversion sequence than the standard conversion sequence 5300 // from the return type of F2 to the destination type. 5301 if (Cand1.Function && Cand2.Function && 5302 isa<CXXConversionDecl>(Cand1.Function) && 5303 isa<CXXConversionDecl>(Cand2.Function)) { 5304 switch (CompareStandardConversionSequences(Cand1.FinalConversion, 5305 Cand2.FinalConversion)) { 5306 case ImplicitConversionSequence::Better: 5307 // Cand1 has a better conversion sequence. 5308 return true; 5309 5310 case ImplicitConversionSequence::Worse: 5311 // Cand1 can't be better than Cand2. 5312 return false; 5313 5314 case ImplicitConversionSequence::Indistinguishable: 5315 // Do nothing 5316 break; 5317 } 5318 } 5319 5320 return false; 5321} 5322 5323/// \brief Computes the best viable function (C++ 13.3.3) 5324/// within an overload candidate set. 5325/// 5326/// \param CandidateSet the set of candidate functions. 5327/// 5328/// \param Loc the location of the function name (or operator symbol) for 5329/// which overload resolution occurs. 5330/// 5331/// \param Best f overload resolution was successful or found a deleted 5332/// function, Best points to the candidate function found. 5333/// 5334/// \returns The result of overload resolution. 5335OverloadingResult Sema::BestViableFunction(OverloadCandidateSet& CandidateSet, 5336 SourceLocation Loc, 5337 OverloadCandidateSet::iterator& Best) { 5338 // Find the best viable function. 5339 Best = CandidateSet.end(); 5340 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 5341 Cand != CandidateSet.end(); ++Cand) { 5342 if (Cand->Viable) { 5343 if (Best == CandidateSet.end() || 5344 isBetterOverloadCandidate(*Cand, *Best, Loc)) 5345 Best = Cand; 5346 } 5347 } 5348 5349 // If we didn't find any viable functions, abort. 5350 if (Best == CandidateSet.end()) 5351 return OR_No_Viable_Function; 5352 5353 // Make sure that this function is better than every other viable 5354 // function. If not, we have an ambiguity. 5355 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 5356 Cand != CandidateSet.end(); ++Cand) { 5357 if (Cand->Viable && 5358 Cand != Best && 5359 !isBetterOverloadCandidate(*Best, *Cand, Loc)) { 5360 Best = CandidateSet.end(); 5361 return OR_Ambiguous; 5362 } 5363 } 5364 5365 // Best is the best viable function. 5366 if (Best->Function && 5367 (Best->Function->isDeleted() || 5368 Best->Function->getAttr<UnavailableAttr>())) 5369 return OR_Deleted; 5370 5371 // C++ [basic.def.odr]p2: 5372 // An overloaded function is used if it is selected by overload resolution 5373 // when referred to from a potentially-evaluated expression. [Note: this 5374 // covers calls to named functions (5.2.2), operator overloading 5375 // (clause 13), user-defined conversions (12.3.2), allocation function for 5376 // placement new (5.3.4), as well as non-default initialization (8.5). 5377 if (Best->Function) 5378 MarkDeclarationReferenced(Loc, Best->Function); 5379 return OR_Success; 5380} 5381 5382namespace { 5383 5384enum OverloadCandidateKind { 5385 oc_function, 5386 oc_method, 5387 oc_constructor, 5388 oc_function_template, 5389 oc_method_template, 5390 oc_constructor_template, 5391 oc_implicit_default_constructor, 5392 oc_implicit_copy_constructor, 5393 oc_implicit_copy_assignment 5394}; 5395 5396OverloadCandidateKind ClassifyOverloadCandidate(Sema &S, 5397 FunctionDecl *Fn, 5398 std::string &Description) { 5399 bool isTemplate = false; 5400 5401 if (FunctionTemplateDecl *FunTmpl = Fn->getPrimaryTemplate()) { 5402 isTemplate = true; 5403 Description = S.getTemplateArgumentBindingsText( 5404 FunTmpl->getTemplateParameters(), *Fn->getTemplateSpecializationArgs()); 5405 } 5406 5407 if (CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(Fn)) { 5408 if (!Ctor->isImplicit()) 5409 return isTemplate ? oc_constructor_template : oc_constructor; 5410 5411 return Ctor->isCopyConstructor() ? oc_implicit_copy_constructor 5412 : oc_implicit_default_constructor; 5413 } 5414 5415 if (CXXMethodDecl *Meth = dyn_cast<CXXMethodDecl>(Fn)) { 5416 // This actually gets spelled 'candidate function' for now, but 5417 // it doesn't hurt to split it out. 5418 if (!Meth->isImplicit()) 5419 return isTemplate ? oc_method_template : oc_method; 5420 5421 assert(Meth->isCopyAssignment() 5422 && "implicit method is not copy assignment operator?"); 5423 return oc_implicit_copy_assignment; 5424 } 5425 5426 return isTemplate ? oc_function_template : oc_function; 5427} 5428 5429} // end anonymous namespace 5430 5431// Notes the location of an overload candidate. 5432void Sema::NoteOverloadCandidate(FunctionDecl *Fn) { 5433 std::string FnDesc; 5434 OverloadCandidateKind K = ClassifyOverloadCandidate(*this, Fn, FnDesc); 5435 Diag(Fn->getLocation(), diag::note_ovl_candidate) 5436 << (unsigned) K << FnDesc; 5437} 5438 5439/// Diagnoses an ambiguous conversion. The partial diagnostic is the 5440/// "lead" diagnostic; it will be given two arguments, the source and 5441/// target types of the conversion. 5442void Sema::DiagnoseAmbiguousConversion(const ImplicitConversionSequence &ICS, 5443 SourceLocation CaretLoc, 5444 const PartialDiagnostic &PDiag) { 5445 Diag(CaretLoc, PDiag) 5446 << ICS.Ambiguous.getFromType() << ICS.Ambiguous.getToType(); 5447 for (AmbiguousConversionSequence::const_iterator 5448 I = ICS.Ambiguous.begin(), E = ICS.Ambiguous.end(); I != E; ++I) { 5449 NoteOverloadCandidate(*I); 5450 } 5451} 5452 5453namespace { 5454 5455void DiagnoseBadConversion(Sema &S, OverloadCandidate *Cand, unsigned I) { 5456 const ImplicitConversionSequence &Conv = Cand->Conversions[I]; 5457 assert(Conv.isBad()); 5458 assert(Cand->Function && "for now, candidate must be a function"); 5459 FunctionDecl *Fn = Cand->Function; 5460 5461 // There's a conversion slot for the object argument if this is a 5462 // non-constructor method. Note that 'I' corresponds the 5463 // conversion-slot index. 5464 bool isObjectArgument = false; 5465 if (isa<CXXMethodDecl>(Fn) && !isa<CXXConstructorDecl>(Fn)) { 5466 if (I == 0) 5467 isObjectArgument = true; 5468 else 5469 I--; 5470 } 5471 5472 std::string FnDesc; 5473 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, FnDesc); 5474 5475 Expr *FromExpr = Conv.Bad.FromExpr; 5476 QualType FromTy = Conv.Bad.getFromType(); 5477 QualType ToTy = Conv.Bad.getToType(); 5478 5479 if (FromTy == S.Context.OverloadTy) { 5480 assert(FromExpr && "overload set argument came from implicit argument?"); 5481 Expr *E = FromExpr->IgnoreParens(); 5482 if (isa<UnaryOperator>(E)) 5483 E = cast<UnaryOperator>(E)->getSubExpr()->IgnoreParens(); 5484 DeclarationName Name = cast<OverloadExpr>(E)->getName(); 5485 5486 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_overload) 5487 << (unsigned) FnKind << FnDesc 5488 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 5489 << ToTy << Name << I+1; 5490 return; 5491 } 5492 5493 // Do some hand-waving analysis to see if the non-viability is due 5494 // to a qualifier mismatch. 5495 CanQualType CFromTy = S.Context.getCanonicalType(FromTy); 5496 CanQualType CToTy = S.Context.getCanonicalType(ToTy); 5497 if (CanQual<ReferenceType> RT = CToTy->getAs<ReferenceType>()) 5498 CToTy = RT->getPointeeType(); 5499 else { 5500 // TODO: detect and diagnose the full richness of const mismatches. 5501 if (CanQual<PointerType> FromPT = CFromTy->getAs<PointerType>()) 5502 if (CanQual<PointerType> ToPT = CToTy->getAs<PointerType>()) 5503 CFromTy = FromPT->getPointeeType(), CToTy = ToPT->getPointeeType(); 5504 } 5505 5506 if (CToTy.getUnqualifiedType() == CFromTy.getUnqualifiedType() && 5507 !CToTy.isAtLeastAsQualifiedAs(CFromTy)) { 5508 // It is dumb that we have to do this here. 5509 while (isa<ArrayType>(CFromTy)) 5510 CFromTy = CFromTy->getAs<ArrayType>()->getElementType(); 5511 while (isa<ArrayType>(CToTy)) 5512 CToTy = CFromTy->getAs<ArrayType>()->getElementType(); 5513 5514 Qualifiers FromQs = CFromTy.getQualifiers(); 5515 Qualifiers ToQs = CToTy.getQualifiers(); 5516 5517 if (FromQs.getAddressSpace() != ToQs.getAddressSpace()) { 5518 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_addrspace) 5519 << (unsigned) FnKind << FnDesc 5520 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 5521 << FromTy 5522 << FromQs.getAddressSpace() << ToQs.getAddressSpace() 5523 << (unsigned) isObjectArgument << I+1; 5524 return; 5525 } 5526 5527 unsigned CVR = FromQs.getCVRQualifiers() & ~ToQs.getCVRQualifiers(); 5528 assert(CVR && "unexpected qualifiers mismatch"); 5529 5530 if (isObjectArgument) { 5531 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr_this) 5532 << (unsigned) FnKind << FnDesc 5533 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 5534 << FromTy << (CVR - 1); 5535 } else { 5536 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr) 5537 << (unsigned) FnKind << FnDesc 5538 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 5539 << FromTy << (CVR - 1) << I+1; 5540 } 5541 return; 5542 } 5543 5544 // Diagnose references or pointers to incomplete types differently, 5545 // since it's far from impossible that the incompleteness triggered 5546 // the failure. 5547 QualType TempFromTy = FromTy.getNonReferenceType(); 5548 if (const PointerType *PTy = TempFromTy->getAs<PointerType>()) 5549 TempFromTy = PTy->getPointeeType(); 5550 if (TempFromTy->isIncompleteType()) { 5551 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_conv_incomplete) 5552 << (unsigned) FnKind << FnDesc 5553 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 5554 << FromTy << ToTy << (unsigned) isObjectArgument << I+1; 5555 return; 5556 } 5557 5558 // Diagnose base -> derived pointer conversions. 5559 unsigned BaseToDerivedConversion = 0; 5560 if (const PointerType *FromPtrTy = FromTy->getAs<PointerType>()) { 5561 if (const PointerType *ToPtrTy = ToTy->getAs<PointerType>()) { 5562 if (ToPtrTy->getPointeeType().isAtLeastAsQualifiedAs( 5563 FromPtrTy->getPointeeType()) && 5564 !FromPtrTy->getPointeeType()->isIncompleteType() && 5565 !ToPtrTy->getPointeeType()->isIncompleteType() && 5566 S.IsDerivedFrom(ToPtrTy->getPointeeType(), 5567 FromPtrTy->getPointeeType())) 5568 BaseToDerivedConversion = 1; 5569 } 5570 } else if (const ObjCObjectPointerType *FromPtrTy 5571 = FromTy->getAs<ObjCObjectPointerType>()) { 5572 if (const ObjCObjectPointerType *ToPtrTy 5573 = ToTy->getAs<ObjCObjectPointerType>()) 5574 if (const ObjCInterfaceDecl *FromIface = FromPtrTy->getInterfaceDecl()) 5575 if (const ObjCInterfaceDecl *ToIface = ToPtrTy->getInterfaceDecl()) 5576 if (ToPtrTy->getPointeeType().isAtLeastAsQualifiedAs( 5577 FromPtrTy->getPointeeType()) && 5578 FromIface->isSuperClassOf(ToIface)) 5579 BaseToDerivedConversion = 2; 5580 } else if (const ReferenceType *ToRefTy = ToTy->getAs<ReferenceType>()) { 5581 if (ToRefTy->getPointeeType().isAtLeastAsQualifiedAs(FromTy) && 5582 !FromTy->isIncompleteType() && 5583 !ToRefTy->getPointeeType()->isIncompleteType() && 5584 S.IsDerivedFrom(ToRefTy->getPointeeType(), FromTy)) 5585 BaseToDerivedConversion = 3; 5586 } 5587 5588 if (BaseToDerivedConversion) { 5589 S.Diag(Fn->getLocation(), 5590 diag::note_ovl_candidate_bad_base_to_derived_conv) 5591 << (unsigned) FnKind << FnDesc 5592 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 5593 << (BaseToDerivedConversion - 1) 5594 << FromTy << ToTy << I+1; 5595 return; 5596 } 5597 5598 // TODO: specialize more based on the kind of mismatch 5599 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_conv) 5600 << (unsigned) FnKind << FnDesc 5601 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 5602 << FromTy << ToTy << (unsigned) isObjectArgument << I+1; 5603} 5604 5605void DiagnoseArityMismatch(Sema &S, OverloadCandidate *Cand, 5606 unsigned NumFormalArgs) { 5607 // TODO: treat calls to a missing default constructor as a special case 5608 5609 FunctionDecl *Fn = Cand->Function; 5610 const FunctionProtoType *FnTy = Fn->getType()->getAs<FunctionProtoType>(); 5611 5612 unsigned MinParams = Fn->getMinRequiredArguments(); 5613 5614 // at least / at most / exactly 5615 // FIXME: variadic templates "at most" should account for parameter packs 5616 unsigned mode, modeCount; 5617 if (NumFormalArgs < MinParams) { 5618 assert((Cand->FailureKind == ovl_fail_too_few_arguments) || 5619 (Cand->FailureKind == ovl_fail_bad_deduction && 5620 Cand->DeductionFailure.Result == Sema::TDK_TooFewArguments)); 5621 if (MinParams != FnTy->getNumArgs() || FnTy->isVariadic()) 5622 mode = 0; // "at least" 5623 else 5624 mode = 2; // "exactly" 5625 modeCount = MinParams; 5626 } else { 5627 assert((Cand->FailureKind == ovl_fail_too_many_arguments) || 5628 (Cand->FailureKind == ovl_fail_bad_deduction && 5629 Cand->DeductionFailure.Result == Sema::TDK_TooManyArguments)); 5630 if (MinParams != FnTy->getNumArgs()) 5631 mode = 1; // "at most" 5632 else 5633 mode = 2; // "exactly" 5634 modeCount = FnTy->getNumArgs(); 5635 } 5636 5637 std::string Description; 5638 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, Description); 5639 5640 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_arity) 5641 << (unsigned) FnKind << (Fn->getDescribedFunctionTemplate() != 0) << mode 5642 << modeCount << NumFormalArgs; 5643} 5644 5645/// Diagnose a failed template-argument deduction. 5646void DiagnoseBadDeduction(Sema &S, OverloadCandidate *Cand, 5647 Expr **Args, unsigned NumArgs) { 5648 FunctionDecl *Fn = Cand->Function; // pattern 5649 5650 TemplateParameter Param = Cand->DeductionFailure.getTemplateParameter(); 5651 NamedDecl *ParamD; 5652 (ParamD = Param.dyn_cast<TemplateTypeParmDecl*>()) || 5653 (ParamD = Param.dyn_cast<NonTypeTemplateParmDecl*>()) || 5654 (ParamD = Param.dyn_cast<TemplateTemplateParmDecl*>()); 5655 switch (Cand->DeductionFailure.Result) { 5656 case Sema::TDK_Success: 5657 llvm_unreachable("TDK_success while diagnosing bad deduction"); 5658 5659 case Sema::TDK_Incomplete: { 5660 assert(ParamD && "no parameter found for incomplete deduction result"); 5661 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_incomplete_deduction) 5662 << ParamD->getDeclName(); 5663 return; 5664 } 5665 5666 case Sema::TDK_Underqualified: { 5667 assert(ParamD && "no parameter found for bad qualifiers deduction result"); 5668 TemplateTypeParmDecl *TParam = cast<TemplateTypeParmDecl>(ParamD); 5669 5670 QualType Param = Cand->DeductionFailure.getFirstArg()->getAsType(); 5671 5672 // Param will have been canonicalized, but it should just be a 5673 // qualified version of ParamD, so move the qualifiers to that. 5674 QualifierCollector Qs(S.Context); 5675 Qs.strip(Param); 5676 QualType NonCanonParam = Qs.apply(TParam->getTypeForDecl()); 5677 assert(S.Context.hasSameType(Param, NonCanonParam)); 5678 5679 // Arg has also been canonicalized, but there's nothing we can do 5680 // about that. It also doesn't matter as much, because it won't 5681 // have any template parameters in it (because deduction isn't 5682 // done on dependent types). 5683 QualType Arg = Cand->DeductionFailure.getSecondArg()->getAsType(); 5684 5685 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_underqualified) 5686 << ParamD->getDeclName() << Arg << NonCanonParam; 5687 return; 5688 } 5689 5690 case Sema::TDK_Inconsistent: { 5691 assert(ParamD && "no parameter found for inconsistent deduction result"); 5692 int which = 0; 5693 if (isa<TemplateTypeParmDecl>(ParamD)) 5694 which = 0; 5695 else if (isa<NonTypeTemplateParmDecl>(ParamD)) 5696 which = 1; 5697 else { 5698 which = 2; 5699 } 5700 5701 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_inconsistent_deduction) 5702 << which << ParamD->getDeclName() 5703 << *Cand->DeductionFailure.getFirstArg() 5704 << *Cand->DeductionFailure.getSecondArg(); 5705 return; 5706 } 5707 5708 case Sema::TDK_InvalidExplicitArguments: 5709 assert(ParamD && "no parameter found for invalid explicit arguments"); 5710 if (ParamD->getDeclName()) 5711 S.Diag(Fn->getLocation(), 5712 diag::note_ovl_candidate_explicit_arg_mismatch_named) 5713 << ParamD->getDeclName(); 5714 else { 5715 int index = 0; 5716 if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(ParamD)) 5717 index = TTP->getIndex(); 5718 else if (NonTypeTemplateParmDecl *NTTP 5719 = dyn_cast<NonTypeTemplateParmDecl>(ParamD)) 5720 index = NTTP->getIndex(); 5721 else 5722 index = cast<TemplateTemplateParmDecl>(ParamD)->getIndex(); 5723 S.Diag(Fn->getLocation(), 5724 diag::note_ovl_candidate_explicit_arg_mismatch_unnamed) 5725 << (index + 1); 5726 } 5727 return; 5728 5729 case Sema::TDK_TooManyArguments: 5730 case Sema::TDK_TooFewArguments: 5731 DiagnoseArityMismatch(S, Cand, NumArgs); 5732 return; 5733 5734 case Sema::TDK_InstantiationDepth: 5735 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_instantiation_depth); 5736 return; 5737 5738 case Sema::TDK_SubstitutionFailure: { 5739 std::string ArgString; 5740 if (TemplateArgumentList *Args 5741 = Cand->DeductionFailure.getTemplateArgumentList()) 5742 ArgString = S.getTemplateArgumentBindingsText( 5743 Fn->getDescribedFunctionTemplate()->getTemplateParameters(), 5744 *Args); 5745 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_substitution_failure) 5746 << ArgString; 5747 return; 5748 } 5749 5750 // TODO: diagnose these individually, then kill off 5751 // note_ovl_candidate_bad_deduction, which is uselessly vague. 5752 case Sema::TDK_NonDeducedMismatch: 5753 case Sema::TDK_FailedOverloadResolution: 5754 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_deduction); 5755 return; 5756 } 5757} 5758 5759/// Generates a 'note' diagnostic for an overload candidate. We've 5760/// already generated a primary error at the call site. 5761/// 5762/// It really does need to be a single diagnostic with its caret 5763/// pointed at the candidate declaration. Yes, this creates some 5764/// major challenges of technical writing. Yes, this makes pointing 5765/// out problems with specific arguments quite awkward. It's still 5766/// better than generating twenty screens of text for every failed 5767/// overload. 5768/// 5769/// It would be great to be able to express per-candidate problems 5770/// more richly for those diagnostic clients that cared, but we'd 5771/// still have to be just as careful with the default diagnostics. 5772void NoteFunctionCandidate(Sema &S, OverloadCandidate *Cand, 5773 Expr **Args, unsigned NumArgs) { 5774 FunctionDecl *Fn = Cand->Function; 5775 5776 // Note deleted candidates, but only if they're viable. 5777 if (Cand->Viable && (Fn->isDeleted() || Fn->hasAttr<UnavailableAttr>())) { 5778 std::string FnDesc; 5779 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, FnDesc); 5780 5781 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_deleted) 5782 << FnKind << FnDesc << Fn->isDeleted(); 5783 return; 5784 } 5785 5786 // We don't really have anything else to say about viable candidates. 5787 if (Cand->Viable) { 5788 S.NoteOverloadCandidate(Fn); 5789 return; 5790 } 5791 5792 switch (Cand->FailureKind) { 5793 case ovl_fail_too_many_arguments: 5794 case ovl_fail_too_few_arguments: 5795 return DiagnoseArityMismatch(S, Cand, NumArgs); 5796 5797 case ovl_fail_bad_deduction: 5798 return DiagnoseBadDeduction(S, Cand, Args, NumArgs); 5799 5800 case ovl_fail_trivial_conversion: 5801 case ovl_fail_bad_final_conversion: 5802 case ovl_fail_final_conversion_not_exact: 5803 return S.NoteOverloadCandidate(Fn); 5804 5805 case ovl_fail_bad_conversion: { 5806 unsigned I = (Cand->IgnoreObjectArgument ? 1 : 0); 5807 for (unsigned N = Cand->Conversions.size(); I != N; ++I) 5808 if (Cand->Conversions[I].isBad()) 5809 return DiagnoseBadConversion(S, Cand, I); 5810 5811 // FIXME: this currently happens when we're called from SemaInit 5812 // when user-conversion overload fails. Figure out how to handle 5813 // those conditions and diagnose them well. 5814 return S.NoteOverloadCandidate(Fn); 5815 } 5816 } 5817} 5818 5819void NoteSurrogateCandidate(Sema &S, OverloadCandidate *Cand) { 5820 // Desugar the type of the surrogate down to a function type, 5821 // retaining as many typedefs as possible while still showing 5822 // the function type (and, therefore, its parameter types). 5823 QualType FnType = Cand->Surrogate->getConversionType(); 5824 bool isLValueReference = false; 5825 bool isRValueReference = false; 5826 bool isPointer = false; 5827 if (const LValueReferenceType *FnTypeRef = 5828 FnType->getAs<LValueReferenceType>()) { 5829 FnType = FnTypeRef->getPointeeType(); 5830 isLValueReference = true; 5831 } else if (const RValueReferenceType *FnTypeRef = 5832 FnType->getAs<RValueReferenceType>()) { 5833 FnType = FnTypeRef->getPointeeType(); 5834 isRValueReference = true; 5835 } 5836 if (const PointerType *FnTypePtr = FnType->getAs<PointerType>()) { 5837 FnType = FnTypePtr->getPointeeType(); 5838 isPointer = true; 5839 } 5840 // Desugar down to a function type. 5841 FnType = QualType(FnType->getAs<FunctionType>(), 0); 5842 // Reconstruct the pointer/reference as appropriate. 5843 if (isPointer) FnType = S.Context.getPointerType(FnType); 5844 if (isRValueReference) FnType = S.Context.getRValueReferenceType(FnType); 5845 if (isLValueReference) FnType = S.Context.getLValueReferenceType(FnType); 5846 5847 S.Diag(Cand->Surrogate->getLocation(), diag::note_ovl_surrogate_cand) 5848 << FnType; 5849} 5850 5851void NoteBuiltinOperatorCandidate(Sema &S, 5852 const char *Opc, 5853 SourceLocation OpLoc, 5854 OverloadCandidate *Cand) { 5855 assert(Cand->Conversions.size() <= 2 && "builtin operator is not binary"); 5856 std::string TypeStr("operator"); 5857 TypeStr += Opc; 5858 TypeStr += "("; 5859 TypeStr += Cand->BuiltinTypes.ParamTypes[0].getAsString(); 5860 if (Cand->Conversions.size() == 1) { 5861 TypeStr += ")"; 5862 S.Diag(OpLoc, diag::note_ovl_builtin_unary_candidate) << TypeStr; 5863 } else { 5864 TypeStr += ", "; 5865 TypeStr += Cand->BuiltinTypes.ParamTypes[1].getAsString(); 5866 TypeStr += ")"; 5867 S.Diag(OpLoc, diag::note_ovl_builtin_binary_candidate) << TypeStr; 5868 } 5869} 5870 5871void NoteAmbiguousUserConversions(Sema &S, SourceLocation OpLoc, 5872 OverloadCandidate *Cand) { 5873 unsigned NoOperands = Cand->Conversions.size(); 5874 for (unsigned ArgIdx = 0; ArgIdx < NoOperands; ++ArgIdx) { 5875 const ImplicitConversionSequence &ICS = Cand->Conversions[ArgIdx]; 5876 if (ICS.isBad()) break; // all meaningless after first invalid 5877 if (!ICS.isAmbiguous()) continue; 5878 5879 S.DiagnoseAmbiguousConversion(ICS, OpLoc, 5880 S.PDiag(diag::note_ambiguous_type_conversion)); 5881 } 5882} 5883 5884SourceLocation GetLocationForCandidate(const OverloadCandidate *Cand) { 5885 if (Cand->Function) 5886 return Cand->Function->getLocation(); 5887 if (Cand->IsSurrogate) 5888 return Cand->Surrogate->getLocation(); 5889 return SourceLocation(); 5890} 5891 5892struct CompareOverloadCandidatesForDisplay { 5893 Sema &S; 5894 CompareOverloadCandidatesForDisplay(Sema &S) : S(S) {} 5895 5896 bool operator()(const OverloadCandidate *L, 5897 const OverloadCandidate *R) { 5898 // Fast-path this check. 5899 if (L == R) return false; 5900 5901 // Order first by viability. 5902 if (L->Viable) { 5903 if (!R->Viable) return true; 5904 5905 // TODO: introduce a tri-valued comparison for overload 5906 // candidates. Would be more worthwhile if we had a sort 5907 // that could exploit it. 5908 if (S.isBetterOverloadCandidate(*L, *R, SourceLocation())) return true; 5909 if (S.isBetterOverloadCandidate(*R, *L, SourceLocation())) return false; 5910 } else if (R->Viable) 5911 return false; 5912 5913 assert(L->Viable == R->Viable); 5914 5915 // Criteria by which we can sort non-viable candidates: 5916 if (!L->Viable) { 5917 // 1. Arity mismatches come after other candidates. 5918 if (L->FailureKind == ovl_fail_too_many_arguments || 5919 L->FailureKind == ovl_fail_too_few_arguments) 5920 return false; 5921 if (R->FailureKind == ovl_fail_too_many_arguments || 5922 R->FailureKind == ovl_fail_too_few_arguments) 5923 return true; 5924 5925 // 2. Bad conversions come first and are ordered by the number 5926 // of bad conversions and quality of good conversions. 5927 if (L->FailureKind == ovl_fail_bad_conversion) { 5928 if (R->FailureKind != ovl_fail_bad_conversion) 5929 return true; 5930 5931 // If there's any ordering between the defined conversions... 5932 // FIXME: this might not be transitive. 5933 assert(L->Conversions.size() == R->Conversions.size()); 5934 5935 int leftBetter = 0; 5936 unsigned I = (L->IgnoreObjectArgument || R->IgnoreObjectArgument); 5937 for (unsigned E = L->Conversions.size(); I != E; ++I) { 5938 switch (S.CompareImplicitConversionSequences(L->Conversions[I], 5939 R->Conversions[I])) { 5940 case ImplicitConversionSequence::Better: 5941 leftBetter++; 5942 break; 5943 5944 case ImplicitConversionSequence::Worse: 5945 leftBetter--; 5946 break; 5947 5948 case ImplicitConversionSequence::Indistinguishable: 5949 break; 5950 } 5951 } 5952 if (leftBetter > 0) return true; 5953 if (leftBetter < 0) return false; 5954 5955 } else if (R->FailureKind == ovl_fail_bad_conversion) 5956 return false; 5957 5958 // TODO: others? 5959 } 5960 5961 // Sort everything else by location. 5962 SourceLocation LLoc = GetLocationForCandidate(L); 5963 SourceLocation RLoc = GetLocationForCandidate(R); 5964 5965 // Put candidates without locations (e.g. builtins) at the end. 5966 if (LLoc.isInvalid()) return false; 5967 if (RLoc.isInvalid()) return true; 5968 5969 return S.SourceMgr.isBeforeInTranslationUnit(LLoc, RLoc); 5970 } 5971}; 5972 5973/// CompleteNonViableCandidate - Normally, overload resolution only 5974/// computes up to the first 5975void CompleteNonViableCandidate(Sema &S, OverloadCandidate *Cand, 5976 Expr **Args, unsigned NumArgs) { 5977 assert(!Cand->Viable); 5978 5979 // Don't do anything on failures other than bad conversion. 5980 if (Cand->FailureKind != ovl_fail_bad_conversion) return; 5981 5982 // Skip forward to the first bad conversion. 5983 unsigned ConvIdx = (Cand->IgnoreObjectArgument ? 1 : 0); 5984 unsigned ConvCount = Cand->Conversions.size(); 5985 while (true) { 5986 assert(ConvIdx != ConvCount && "no bad conversion in candidate"); 5987 ConvIdx++; 5988 if (Cand->Conversions[ConvIdx - 1].isBad()) 5989 break; 5990 } 5991 5992 if (ConvIdx == ConvCount) 5993 return; 5994 5995 assert(!Cand->Conversions[ConvIdx].isInitialized() && 5996 "remaining conversion is initialized?"); 5997 5998 // FIXME: this should probably be preserved from the overload 5999 // operation somehow. 6000 bool SuppressUserConversions = false; 6001 6002 const FunctionProtoType* Proto; 6003 unsigned ArgIdx = ConvIdx; 6004 6005 if (Cand->IsSurrogate) { 6006 QualType ConvType 6007 = Cand->Surrogate->getConversionType().getNonReferenceType(); 6008 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 6009 ConvType = ConvPtrType->getPointeeType(); 6010 Proto = ConvType->getAs<FunctionProtoType>(); 6011 ArgIdx--; 6012 } else if (Cand->Function) { 6013 Proto = Cand->Function->getType()->getAs<FunctionProtoType>(); 6014 if (isa<CXXMethodDecl>(Cand->Function) && 6015 !isa<CXXConstructorDecl>(Cand->Function)) 6016 ArgIdx--; 6017 } else { 6018 // Builtin binary operator with a bad first conversion. 6019 assert(ConvCount <= 3); 6020 for (; ConvIdx != ConvCount; ++ConvIdx) 6021 Cand->Conversions[ConvIdx] 6022 = TryCopyInitialization(S, Args[ConvIdx], 6023 Cand->BuiltinTypes.ParamTypes[ConvIdx], 6024 SuppressUserConversions, 6025 /*InOverloadResolution*/ true); 6026 return; 6027 } 6028 6029 // Fill in the rest of the conversions. 6030 unsigned NumArgsInProto = Proto->getNumArgs(); 6031 for (; ConvIdx != ConvCount; ++ConvIdx, ++ArgIdx) { 6032 if (ArgIdx < NumArgsInProto) 6033 Cand->Conversions[ConvIdx] 6034 = TryCopyInitialization(S, Args[ArgIdx], Proto->getArgType(ArgIdx), 6035 SuppressUserConversions, 6036 /*InOverloadResolution=*/true); 6037 else 6038 Cand->Conversions[ConvIdx].setEllipsis(); 6039 } 6040} 6041 6042} // end anonymous namespace 6043 6044/// PrintOverloadCandidates - When overload resolution fails, prints 6045/// diagnostic messages containing the candidates in the candidate 6046/// set. 6047void 6048Sema::PrintOverloadCandidates(OverloadCandidateSet& CandidateSet, 6049 OverloadCandidateDisplayKind OCD, 6050 Expr **Args, unsigned NumArgs, 6051 const char *Opc, 6052 SourceLocation OpLoc) { 6053 // Sort the candidates by viability and position. Sorting directly would 6054 // be prohibitive, so we make a set of pointers and sort those. 6055 llvm::SmallVector<OverloadCandidate*, 32> Cands; 6056 if (OCD == OCD_AllCandidates) Cands.reserve(CandidateSet.size()); 6057 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 6058 LastCand = CandidateSet.end(); 6059 Cand != LastCand; ++Cand) { 6060 if (Cand->Viable) 6061 Cands.push_back(Cand); 6062 else if (OCD == OCD_AllCandidates) { 6063 CompleteNonViableCandidate(*this, Cand, Args, NumArgs); 6064 if (Cand->Function || Cand->IsSurrogate) 6065 Cands.push_back(Cand); 6066 // Otherwise, this a non-viable builtin candidate. We do not, in general, 6067 // want to list every possible builtin candidate. 6068 } 6069 } 6070 6071 std::sort(Cands.begin(), Cands.end(), 6072 CompareOverloadCandidatesForDisplay(*this)); 6073 6074 bool ReportedAmbiguousConversions = false; 6075 6076 llvm::SmallVectorImpl<OverloadCandidate*>::iterator I, E; 6077 const Diagnostic::OverloadsShown ShowOverloads = Diags.getShowOverloads(); 6078 unsigned CandsShown = 0; 6079 for (I = Cands.begin(), E = Cands.end(); I != E; ++I) { 6080 OverloadCandidate *Cand = *I; 6081 6082 // Set an arbitrary limit on the number of candidate functions we'll spam 6083 // the user with. FIXME: This limit should depend on details of the 6084 // candidate list. 6085 if (CandsShown >= 4 && ShowOverloads == Diagnostic::Ovl_Best) { 6086 break; 6087 } 6088 ++CandsShown; 6089 6090 if (Cand->Function) 6091 NoteFunctionCandidate(*this, Cand, Args, NumArgs); 6092 else if (Cand->IsSurrogate) 6093 NoteSurrogateCandidate(*this, Cand); 6094 else { 6095 assert(Cand->Viable && 6096 "Non-viable built-in candidates are not added to Cands."); 6097 // Generally we only see ambiguities including viable builtin 6098 // operators if overload resolution got screwed up by an 6099 // ambiguous user-defined conversion. 6100 // 6101 // FIXME: It's quite possible for different conversions to see 6102 // different ambiguities, though. 6103 if (!ReportedAmbiguousConversions) { 6104 NoteAmbiguousUserConversions(*this, OpLoc, Cand); 6105 ReportedAmbiguousConversions = true; 6106 } 6107 6108 // If this is a viable builtin, print it. 6109 NoteBuiltinOperatorCandidate(*this, Opc, OpLoc, Cand); 6110 } 6111 } 6112 6113 if (I != E) 6114 Diag(OpLoc, diag::note_ovl_too_many_candidates) << int(E - I); 6115} 6116 6117static bool CheckUnresolvedAccess(Sema &S, OverloadExpr *E, DeclAccessPair D) { 6118 if (isa<UnresolvedLookupExpr>(E)) 6119 return S.CheckUnresolvedLookupAccess(cast<UnresolvedLookupExpr>(E), D); 6120 6121 return S.CheckUnresolvedMemberAccess(cast<UnresolvedMemberExpr>(E), D); 6122} 6123 6124/// ResolveAddressOfOverloadedFunction - Try to resolve the address of 6125/// an overloaded function (C++ [over.over]), where @p From is an 6126/// expression with overloaded function type and @p ToType is the type 6127/// we're trying to resolve to. For example: 6128/// 6129/// @code 6130/// int f(double); 6131/// int f(int); 6132/// 6133/// int (*pfd)(double) = f; // selects f(double) 6134/// @endcode 6135/// 6136/// This routine returns the resulting FunctionDecl if it could be 6137/// resolved, and NULL otherwise. When @p Complain is true, this 6138/// routine will emit diagnostics if there is an error. 6139FunctionDecl * 6140Sema::ResolveAddressOfOverloadedFunction(Expr *From, QualType ToType, 6141 bool Complain, 6142 DeclAccessPair &FoundResult) { 6143 QualType FunctionType = ToType; 6144 bool IsMember = false; 6145 if (const PointerType *ToTypePtr = ToType->getAs<PointerType>()) 6146 FunctionType = ToTypePtr->getPointeeType(); 6147 else if (const ReferenceType *ToTypeRef = ToType->getAs<ReferenceType>()) 6148 FunctionType = ToTypeRef->getPointeeType(); 6149 else if (const MemberPointerType *MemTypePtr = 6150 ToType->getAs<MemberPointerType>()) { 6151 FunctionType = MemTypePtr->getPointeeType(); 6152 IsMember = true; 6153 } 6154 6155 // C++ [over.over]p1: 6156 // [...] [Note: any redundant set of parentheses surrounding the 6157 // overloaded function name is ignored (5.1). ] 6158 // C++ [over.over]p1: 6159 // [...] The overloaded function name can be preceded by the & 6160 // operator. 6161 OverloadExpr *OvlExpr = OverloadExpr::find(From).getPointer(); 6162 TemplateArgumentListInfo ETABuffer, *ExplicitTemplateArgs = 0; 6163 if (OvlExpr->hasExplicitTemplateArgs()) { 6164 OvlExpr->getExplicitTemplateArgs().copyInto(ETABuffer); 6165 ExplicitTemplateArgs = &ETABuffer; 6166 } 6167 6168 // We expect a pointer or reference to function, or a function pointer. 6169 FunctionType = Context.getCanonicalType(FunctionType).getUnqualifiedType(); 6170 if (!FunctionType->isFunctionType()) { 6171 if (Complain) 6172 Diag(From->getLocStart(), diag::err_addr_ovl_not_func_ptrref) 6173 << OvlExpr->getName() << ToType; 6174 6175 return 0; 6176 } 6177 6178 assert(From->getType() == Context.OverloadTy); 6179 6180 // Look through all of the overloaded functions, searching for one 6181 // whose type matches exactly. 6182 llvm::SmallVector<std::pair<DeclAccessPair, FunctionDecl*>, 4> Matches; 6183 llvm::SmallVector<FunctionDecl *, 4> NonMatches; 6184 6185 bool FoundNonTemplateFunction = false; 6186 for (UnresolvedSetIterator I = OvlExpr->decls_begin(), 6187 E = OvlExpr->decls_end(); I != E; ++I) { 6188 // Look through any using declarations to find the underlying function. 6189 NamedDecl *Fn = (*I)->getUnderlyingDecl(); 6190 6191 // C++ [over.over]p3: 6192 // Non-member functions and static member functions match 6193 // targets of type "pointer-to-function" or "reference-to-function." 6194 // Nonstatic member functions match targets of 6195 // type "pointer-to-member-function." 6196 // Note that according to DR 247, the containing class does not matter. 6197 6198 if (FunctionTemplateDecl *FunctionTemplate 6199 = dyn_cast<FunctionTemplateDecl>(Fn)) { 6200 if (CXXMethodDecl *Method 6201 = dyn_cast<CXXMethodDecl>(FunctionTemplate->getTemplatedDecl())) { 6202 // Skip non-static function templates when converting to pointer, and 6203 // static when converting to member pointer. 6204 if (Method->isStatic() == IsMember) 6205 continue; 6206 } else if (IsMember) 6207 continue; 6208 6209 // C++ [over.over]p2: 6210 // If the name is a function template, template argument deduction is 6211 // done (14.8.2.2), and if the argument deduction succeeds, the 6212 // resulting template argument list is used to generate a single 6213 // function template specialization, which is added to the set of 6214 // overloaded functions considered. 6215 // FIXME: We don't really want to build the specialization here, do we? 6216 FunctionDecl *Specialization = 0; 6217 TemplateDeductionInfo Info(Context, OvlExpr->getNameLoc()); 6218 if (TemplateDeductionResult Result 6219 = DeduceTemplateArguments(FunctionTemplate, ExplicitTemplateArgs, 6220 FunctionType, Specialization, Info)) { 6221 // FIXME: make a note of the failed deduction for diagnostics. 6222 (void)Result; 6223 } else { 6224 // FIXME: If the match isn't exact, shouldn't we just drop this as 6225 // a candidate? Find a testcase before changing the code. 6226 assert(FunctionType 6227 == Context.getCanonicalType(Specialization->getType())); 6228 Matches.push_back(std::make_pair(I.getPair(), 6229 cast<FunctionDecl>(Specialization->getCanonicalDecl()))); 6230 } 6231 6232 continue; 6233 } 6234 6235 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 6236 // Skip non-static functions when converting to pointer, and static 6237 // when converting to member pointer. 6238 if (Method->isStatic() == IsMember) 6239 continue; 6240 6241 // If we have explicit template arguments, skip non-templates. 6242 if (OvlExpr->hasExplicitTemplateArgs()) 6243 continue; 6244 } else if (IsMember) 6245 continue; 6246 6247 if (FunctionDecl *FunDecl = dyn_cast<FunctionDecl>(Fn)) { 6248 QualType ResultTy; 6249 if (Context.hasSameUnqualifiedType(FunctionType, FunDecl->getType()) || 6250 IsNoReturnConversion(Context, FunDecl->getType(), FunctionType, 6251 ResultTy)) { 6252 Matches.push_back(std::make_pair(I.getPair(), 6253 cast<FunctionDecl>(FunDecl->getCanonicalDecl()))); 6254 FoundNonTemplateFunction = true; 6255 } 6256 } 6257 } 6258 6259 // If there were 0 or 1 matches, we're done. 6260 if (Matches.empty()) { 6261 if (Complain) { 6262 Diag(From->getLocStart(), diag::err_addr_ovl_no_viable) 6263 << OvlExpr->getName() << FunctionType; 6264 for (UnresolvedSetIterator I = OvlExpr->decls_begin(), 6265 E = OvlExpr->decls_end(); 6266 I != E; ++I) 6267 if (FunctionDecl *F = dyn_cast<FunctionDecl>((*I)->getUnderlyingDecl())) 6268 NoteOverloadCandidate(F); 6269 } 6270 6271 return 0; 6272 } else if (Matches.size() == 1) { 6273 FunctionDecl *Result = Matches[0].second; 6274 FoundResult = Matches[0].first; 6275 MarkDeclarationReferenced(From->getLocStart(), Result); 6276 if (Complain) 6277 CheckAddressOfMemberAccess(OvlExpr, Matches[0].first); 6278 return Result; 6279 } 6280 6281 // C++ [over.over]p4: 6282 // If more than one function is selected, [...] 6283 if (!FoundNonTemplateFunction) { 6284 // [...] and any given function template specialization F1 is 6285 // eliminated if the set contains a second function template 6286 // specialization whose function template is more specialized 6287 // than the function template of F1 according to the partial 6288 // ordering rules of 14.5.5.2. 6289 6290 // The algorithm specified above is quadratic. We instead use a 6291 // two-pass algorithm (similar to the one used to identify the 6292 // best viable function in an overload set) that identifies the 6293 // best function template (if it exists). 6294 6295 UnresolvedSet<4> MatchesCopy; // TODO: avoid! 6296 for (unsigned I = 0, E = Matches.size(); I != E; ++I) 6297 MatchesCopy.addDecl(Matches[I].second, Matches[I].first.getAccess()); 6298 6299 UnresolvedSetIterator Result = 6300 getMostSpecialized(MatchesCopy.begin(), MatchesCopy.end(), 6301 TPOC_Other, From->getLocStart(), 6302 PDiag(), 6303 PDiag(diag::err_addr_ovl_ambiguous) 6304 << Matches[0].second->getDeclName(), 6305 PDiag(diag::note_ovl_candidate) 6306 << (unsigned) oc_function_template); 6307 assert(Result != MatchesCopy.end() && "no most-specialized template"); 6308 MarkDeclarationReferenced(From->getLocStart(), *Result); 6309 FoundResult = Matches[Result - MatchesCopy.begin()].first; 6310 if (Complain) { 6311 CheckUnresolvedAccess(*this, OvlExpr, FoundResult); 6312 DiagnoseUseOfDecl(FoundResult, OvlExpr->getNameLoc()); 6313 } 6314 return cast<FunctionDecl>(*Result); 6315 } 6316 6317 // [...] any function template specializations in the set are 6318 // eliminated if the set also contains a non-template function, [...] 6319 for (unsigned I = 0, N = Matches.size(); I != N; ) { 6320 if (Matches[I].second->getPrimaryTemplate() == 0) 6321 ++I; 6322 else { 6323 Matches[I] = Matches[--N]; 6324 Matches.set_size(N); 6325 } 6326 } 6327 6328 // [...] After such eliminations, if any, there shall remain exactly one 6329 // selected function. 6330 if (Matches.size() == 1) { 6331 MarkDeclarationReferenced(From->getLocStart(), Matches[0].second); 6332 FoundResult = Matches[0].first; 6333 if (Complain) { 6334 CheckUnresolvedAccess(*this, OvlExpr, Matches[0].first); 6335 DiagnoseUseOfDecl(Matches[0].first, OvlExpr->getNameLoc()); 6336 } 6337 return cast<FunctionDecl>(Matches[0].second); 6338 } 6339 6340 // FIXME: We should probably return the same thing that BestViableFunction 6341 // returns (even if we issue the diagnostics here). 6342 Diag(From->getLocStart(), diag::err_addr_ovl_ambiguous) 6343 << Matches[0].second->getDeclName(); 6344 for (unsigned I = 0, E = Matches.size(); I != E; ++I) 6345 NoteOverloadCandidate(Matches[I].second); 6346 return 0; 6347} 6348 6349/// \brief Given an expression that refers to an overloaded function, try to 6350/// resolve that overloaded function expression down to a single function. 6351/// 6352/// This routine can only resolve template-ids that refer to a single function 6353/// template, where that template-id refers to a single template whose template 6354/// arguments are either provided by the template-id or have defaults, 6355/// as described in C++0x [temp.arg.explicit]p3. 6356FunctionDecl *Sema::ResolveSingleFunctionTemplateSpecialization(Expr *From) { 6357 // C++ [over.over]p1: 6358 // [...] [Note: any redundant set of parentheses surrounding the 6359 // overloaded function name is ignored (5.1). ] 6360 // C++ [over.over]p1: 6361 // [...] The overloaded function name can be preceded by the & 6362 // operator. 6363 6364 if (From->getType() != Context.OverloadTy) 6365 return 0; 6366 6367 OverloadExpr *OvlExpr = OverloadExpr::find(From).getPointer(); 6368 6369 // If we didn't actually find any template-ids, we're done. 6370 if (!OvlExpr->hasExplicitTemplateArgs()) 6371 return 0; 6372 6373 TemplateArgumentListInfo ExplicitTemplateArgs; 6374 OvlExpr->getExplicitTemplateArgs().copyInto(ExplicitTemplateArgs); 6375 6376 // Look through all of the overloaded functions, searching for one 6377 // whose type matches exactly. 6378 FunctionDecl *Matched = 0; 6379 for (UnresolvedSetIterator I = OvlExpr->decls_begin(), 6380 E = OvlExpr->decls_end(); I != E; ++I) { 6381 // C++0x [temp.arg.explicit]p3: 6382 // [...] In contexts where deduction is done and fails, or in contexts 6383 // where deduction is not done, if a template argument list is 6384 // specified and it, along with any default template arguments, 6385 // identifies a single function template specialization, then the 6386 // template-id is an lvalue for the function template specialization. 6387 FunctionTemplateDecl *FunctionTemplate 6388 = cast<FunctionTemplateDecl>((*I)->getUnderlyingDecl()); 6389 6390 // C++ [over.over]p2: 6391 // If the name is a function template, template argument deduction is 6392 // done (14.8.2.2), and if the argument deduction succeeds, the 6393 // resulting template argument list is used to generate a single 6394 // function template specialization, which is added to the set of 6395 // overloaded functions considered. 6396 FunctionDecl *Specialization = 0; 6397 TemplateDeductionInfo Info(Context, OvlExpr->getNameLoc()); 6398 if (TemplateDeductionResult Result 6399 = DeduceTemplateArguments(FunctionTemplate, &ExplicitTemplateArgs, 6400 Specialization, Info)) { 6401 // FIXME: make a note of the failed deduction for diagnostics. 6402 (void)Result; 6403 continue; 6404 } 6405 6406 // Multiple matches; we can't resolve to a single declaration. 6407 if (Matched) 6408 return 0; 6409 6410 Matched = Specialization; 6411 } 6412 6413 return Matched; 6414} 6415 6416/// \brief Add a single candidate to the overload set. 6417static void AddOverloadedCallCandidate(Sema &S, 6418 DeclAccessPair FoundDecl, 6419 const TemplateArgumentListInfo *ExplicitTemplateArgs, 6420 Expr **Args, unsigned NumArgs, 6421 OverloadCandidateSet &CandidateSet, 6422 bool PartialOverloading) { 6423 NamedDecl *Callee = FoundDecl.getDecl(); 6424 if (isa<UsingShadowDecl>(Callee)) 6425 Callee = cast<UsingShadowDecl>(Callee)->getTargetDecl(); 6426 6427 if (FunctionDecl *Func = dyn_cast<FunctionDecl>(Callee)) { 6428 assert(!ExplicitTemplateArgs && "Explicit template arguments?"); 6429 S.AddOverloadCandidate(Func, FoundDecl, Args, NumArgs, CandidateSet, 6430 false, PartialOverloading); 6431 return; 6432 } 6433 6434 if (FunctionTemplateDecl *FuncTemplate 6435 = dyn_cast<FunctionTemplateDecl>(Callee)) { 6436 S.AddTemplateOverloadCandidate(FuncTemplate, FoundDecl, 6437 ExplicitTemplateArgs, 6438 Args, NumArgs, CandidateSet); 6439 return; 6440 } 6441 6442 assert(false && "unhandled case in overloaded call candidate"); 6443 6444 // do nothing? 6445} 6446 6447/// \brief Add the overload candidates named by callee and/or found by argument 6448/// dependent lookup to the given overload set. 6449void Sema::AddOverloadedCallCandidates(UnresolvedLookupExpr *ULE, 6450 Expr **Args, unsigned NumArgs, 6451 OverloadCandidateSet &CandidateSet, 6452 bool PartialOverloading) { 6453 6454#ifndef NDEBUG 6455 // Verify that ArgumentDependentLookup is consistent with the rules 6456 // in C++0x [basic.lookup.argdep]p3: 6457 // 6458 // Let X be the lookup set produced by unqualified lookup (3.4.1) 6459 // and let Y be the lookup set produced by argument dependent 6460 // lookup (defined as follows). If X contains 6461 // 6462 // -- a declaration of a class member, or 6463 // 6464 // -- a block-scope function declaration that is not a 6465 // using-declaration, or 6466 // 6467 // -- a declaration that is neither a function or a function 6468 // template 6469 // 6470 // then Y is empty. 6471 6472 if (ULE->requiresADL()) { 6473 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(), 6474 E = ULE->decls_end(); I != E; ++I) { 6475 assert(!(*I)->getDeclContext()->isRecord()); 6476 assert(isa<UsingShadowDecl>(*I) || 6477 !(*I)->getDeclContext()->isFunctionOrMethod()); 6478 assert((*I)->getUnderlyingDecl()->isFunctionOrFunctionTemplate()); 6479 } 6480 } 6481#endif 6482 6483 // It would be nice to avoid this copy. 6484 TemplateArgumentListInfo TABuffer; 6485 const TemplateArgumentListInfo *ExplicitTemplateArgs = 0; 6486 if (ULE->hasExplicitTemplateArgs()) { 6487 ULE->copyTemplateArgumentsInto(TABuffer); 6488 ExplicitTemplateArgs = &TABuffer; 6489 } 6490 6491 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(), 6492 E = ULE->decls_end(); I != E; ++I) 6493 AddOverloadedCallCandidate(*this, I.getPair(), ExplicitTemplateArgs, 6494 Args, NumArgs, CandidateSet, 6495 PartialOverloading); 6496 6497 if (ULE->requiresADL()) 6498 AddArgumentDependentLookupCandidates(ULE->getName(), /*Operator*/ false, 6499 Args, NumArgs, 6500 ExplicitTemplateArgs, 6501 CandidateSet, 6502 PartialOverloading); 6503} 6504 6505/// Attempts to recover from a call where no functions were found. 6506/// 6507/// Returns true if new candidates were found. 6508static Sema::OwningExprResult 6509BuildRecoveryCallExpr(Sema &SemaRef, Scope *S, Expr *Fn, 6510 UnresolvedLookupExpr *ULE, 6511 SourceLocation LParenLoc, 6512 Expr **Args, unsigned NumArgs, 6513 SourceLocation *CommaLocs, 6514 SourceLocation RParenLoc) { 6515 6516 CXXScopeSpec SS; 6517 if (ULE->getQualifier()) { 6518 SS.setScopeRep(ULE->getQualifier()); 6519 SS.setRange(ULE->getQualifierRange()); 6520 } 6521 6522 TemplateArgumentListInfo TABuffer; 6523 const TemplateArgumentListInfo *ExplicitTemplateArgs = 0; 6524 if (ULE->hasExplicitTemplateArgs()) { 6525 ULE->copyTemplateArgumentsInto(TABuffer); 6526 ExplicitTemplateArgs = &TABuffer; 6527 } 6528 6529 LookupResult R(SemaRef, ULE->getName(), ULE->getNameLoc(), 6530 Sema::LookupOrdinaryName); 6531 if (SemaRef.DiagnoseEmptyLookup(S, SS, R, Sema::CTC_Expression)) 6532 return SemaRef.ExprError(); 6533 6534 assert(!R.empty() && "lookup results empty despite recovery"); 6535 6536 // Build an implicit member call if appropriate. Just drop the 6537 // casts and such from the call, we don't really care. 6538 Sema::OwningExprResult NewFn = SemaRef.ExprError(); 6539 if ((*R.begin())->isCXXClassMember()) 6540 NewFn = SemaRef.BuildPossibleImplicitMemberExpr(SS, R, ExplicitTemplateArgs); 6541 else if (ExplicitTemplateArgs) 6542 NewFn = SemaRef.BuildTemplateIdExpr(SS, R, false, *ExplicitTemplateArgs); 6543 else 6544 NewFn = SemaRef.BuildDeclarationNameExpr(SS, R, false); 6545 6546 if (NewFn.isInvalid()) 6547 return SemaRef.ExprError(); 6548 6549 // This shouldn't cause an infinite loop because we're giving it 6550 // an expression with non-empty lookup results, which should never 6551 // end up here. 6552 return SemaRef.ActOnCallExpr(/*Scope*/ 0, NewFn.take(), LParenLoc, 6553 Sema::MultiExprArg(SemaRef, Args, NumArgs), 6554 CommaLocs, RParenLoc); 6555} 6556 6557/// ResolveOverloadedCallFn - Given the call expression that calls Fn 6558/// (which eventually refers to the declaration Func) and the call 6559/// arguments Args/NumArgs, attempt to resolve the function call down 6560/// to a specific function. If overload resolution succeeds, returns 6561/// the function declaration produced by overload 6562/// resolution. Otherwise, emits diagnostics, deletes all of the 6563/// arguments and Fn, and returns NULL. 6564Sema::OwningExprResult 6565Sema::BuildOverloadedCallExpr(Scope *S, Expr *Fn, UnresolvedLookupExpr *ULE, 6566 SourceLocation LParenLoc, 6567 Expr **Args, unsigned NumArgs, 6568 SourceLocation *CommaLocs, 6569 SourceLocation RParenLoc) { 6570#ifndef NDEBUG 6571 if (ULE->requiresADL()) { 6572 // To do ADL, we must have found an unqualified name. 6573 assert(!ULE->getQualifier() && "qualified name with ADL"); 6574 6575 // We don't perform ADL for implicit declarations of builtins. 6576 // Verify that this was correctly set up. 6577 FunctionDecl *F; 6578 if (ULE->decls_begin() + 1 == ULE->decls_end() && 6579 (F = dyn_cast<FunctionDecl>(*ULE->decls_begin())) && 6580 F->getBuiltinID() && F->isImplicit()) 6581 assert(0 && "performing ADL for builtin"); 6582 6583 // We don't perform ADL in C. 6584 assert(getLangOptions().CPlusPlus && "ADL enabled in C"); 6585 } 6586#endif 6587 6588 OverloadCandidateSet CandidateSet(Fn->getExprLoc()); 6589 6590 // Add the functions denoted by the callee to the set of candidate 6591 // functions, including those from argument-dependent lookup. 6592 AddOverloadedCallCandidates(ULE, Args, NumArgs, CandidateSet); 6593 6594 // If we found nothing, try to recover. 6595 // AddRecoveryCallCandidates diagnoses the error itself, so we just 6596 // bailout out if it fails. 6597 if (CandidateSet.empty()) 6598 return BuildRecoveryCallExpr(*this, S, Fn, ULE, LParenLoc, Args, NumArgs, 6599 CommaLocs, RParenLoc); 6600 6601 OverloadCandidateSet::iterator Best; 6602 switch (BestViableFunction(CandidateSet, Fn->getLocStart(), Best)) { 6603 case OR_Success: { 6604 FunctionDecl *FDecl = Best->Function; 6605 CheckUnresolvedLookupAccess(ULE, Best->FoundDecl); 6606 DiagnoseUseOfDecl(Best->FoundDecl, ULE->getNameLoc()); 6607 Fn = FixOverloadedFunctionReference(Fn, Best->FoundDecl, FDecl); 6608 return BuildResolvedCallExpr(Fn, FDecl, LParenLoc, Args, NumArgs, RParenLoc); 6609 } 6610 6611 case OR_No_Viable_Function: 6612 Diag(Fn->getSourceRange().getBegin(), 6613 diag::err_ovl_no_viable_function_in_call) 6614 << ULE->getName() << Fn->getSourceRange(); 6615 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6616 break; 6617 6618 case OR_Ambiguous: 6619 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_ambiguous_call) 6620 << ULE->getName() << Fn->getSourceRange(); 6621 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, NumArgs); 6622 break; 6623 6624 case OR_Deleted: 6625 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_deleted_call) 6626 << Best->Function->isDeleted() 6627 << ULE->getName() 6628 << Fn->getSourceRange(); 6629 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6630 break; 6631 } 6632 6633 // Overload resolution failed. 6634 return ExprError(); 6635} 6636 6637static bool IsOverloaded(const UnresolvedSetImpl &Functions) { 6638 return Functions.size() > 1 || 6639 (Functions.size() == 1 && isa<FunctionTemplateDecl>(*Functions.begin())); 6640} 6641 6642/// \brief Create a unary operation that may resolve to an overloaded 6643/// operator. 6644/// 6645/// \param OpLoc The location of the operator itself (e.g., '*'). 6646/// 6647/// \param OpcIn The UnaryOperator::Opcode that describes this 6648/// operator. 6649/// 6650/// \param Functions The set of non-member functions that will be 6651/// considered by overload resolution. The caller needs to build this 6652/// set based on the context using, e.g., 6653/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 6654/// set should not contain any member functions; those will be added 6655/// by CreateOverloadedUnaryOp(). 6656/// 6657/// \param input The input argument. 6658Sema::OwningExprResult 6659Sema::CreateOverloadedUnaryOp(SourceLocation OpLoc, unsigned OpcIn, 6660 const UnresolvedSetImpl &Fns, 6661 Expr *Input) { 6662 UnaryOperator::Opcode Opc = static_cast<UnaryOperator::Opcode>(OpcIn); 6663 6664 OverloadedOperatorKind Op = UnaryOperator::getOverloadedOperator(Opc); 6665 assert(Op != OO_None && "Invalid opcode for overloaded unary operator"); 6666 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 6667 // TODO: provide better source location info. 6668 DeclarationNameInfo OpNameInfo(OpName, OpLoc); 6669 6670 Expr *Args[2] = { Input, 0 }; 6671 unsigned NumArgs = 1; 6672 6673 // For post-increment and post-decrement, add the implicit '0' as 6674 // the second argument, so that we know this is a post-increment or 6675 // post-decrement. 6676 if (Opc == UnaryOperator::PostInc || Opc == UnaryOperator::PostDec) { 6677 llvm::APSInt Zero(Context.getTypeSize(Context.IntTy), false); 6678 Args[1] = new (Context) IntegerLiteral(Zero, Context.IntTy, 6679 SourceLocation()); 6680 NumArgs = 2; 6681 } 6682 6683 if (Input->isTypeDependent()) { 6684 if (Fns.empty()) 6685 return Owned(new (Context) UnaryOperator(Input, 6686 Opc, 6687 Context.DependentTy, 6688 OpLoc)); 6689 6690 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 6691 UnresolvedLookupExpr *Fn 6692 = UnresolvedLookupExpr::Create(Context, /*Dependent*/ true, NamingClass, 6693 0, SourceRange(), OpNameInfo, 6694 /*ADL*/ true, IsOverloaded(Fns), 6695 Fns.begin(), Fns.end()); 6696 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 6697 &Args[0], NumArgs, 6698 Context.DependentTy, 6699 OpLoc)); 6700 } 6701 6702 // Build an empty overload set. 6703 OverloadCandidateSet CandidateSet(OpLoc); 6704 6705 // Add the candidates from the given function set. 6706 AddFunctionCandidates(Fns, &Args[0], NumArgs, CandidateSet, false); 6707 6708 // Add operator candidates that are member functions. 6709 AddMemberOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 6710 6711 // Add candidates from ADL. 6712 AddArgumentDependentLookupCandidates(OpName, /*Operator*/ true, 6713 Args, NumArgs, 6714 /*ExplicitTemplateArgs*/ 0, 6715 CandidateSet); 6716 6717 // Add builtin operator candidates. 6718 AddBuiltinOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 6719 6720 // Perform overload resolution. 6721 OverloadCandidateSet::iterator Best; 6722 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 6723 case OR_Success: { 6724 // We found a built-in operator or an overloaded operator. 6725 FunctionDecl *FnDecl = Best->Function; 6726 6727 if (FnDecl) { 6728 // We matched an overloaded operator. Build a call to that 6729 // operator. 6730 6731 // Convert the arguments. 6732 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 6733 CheckMemberOperatorAccess(OpLoc, Args[0], 0, Best->FoundDecl); 6734 6735 if (PerformObjectArgumentInitialization(Input, /*Qualifier=*/0, 6736 Best->FoundDecl, Method)) 6737 return ExprError(); 6738 } else { 6739 // Convert the arguments. 6740 OwningExprResult InputInit 6741 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 6742 FnDecl->getParamDecl(0)), 6743 SourceLocation(), 6744 Input); 6745 if (InputInit.isInvalid()) 6746 return ExprError(); 6747 Input = InputInit.take(); 6748 } 6749 6750 DiagnoseUseOfDecl(Best->FoundDecl, OpLoc); 6751 6752 // Determine the result type 6753 QualType ResultTy = FnDecl->getCallResultType(); 6754 6755 // Build the actual expression node. 6756 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 6757 SourceLocation()); 6758 UsualUnaryConversions(FnExpr); 6759 6760 Args[0] = Input; 6761 CallExpr *TheCall = 6762 new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 6763 Args, NumArgs, ResultTy, OpLoc); 6764 6765 if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall, 6766 FnDecl)) 6767 return ExprError(); 6768 6769 return MaybeBindToTemporary(TheCall); 6770 } else { 6771 // We matched a built-in operator. Convert the arguments, then 6772 // break out so that we will build the appropriate built-in 6773 // operator node. 6774 if (PerformImplicitConversion(Input, Best->BuiltinTypes.ParamTypes[0], 6775 Best->Conversions[0], AA_Passing)) 6776 return ExprError(); 6777 6778 break; 6779 } 6780 } 6781 6782 case OR_No_Viable_Function: 6783 // No viable function; fall through to handling this as a 6784 // built-in operator, which will produce an error message for us. 6785 break; 6786 6787 case OR_Ambiguous: 6788 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 6789 << UnaryOperator::getOpcodeStr(Opc) 6790 << Input->getSourceRange(); 6791 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, NumArgs, 6792 UnaryOperator::getOpcodeStr(Opc), OpLoc); 6793 return ExprError(); 6794 6795 case OR_Deleted: 6796 Diag(OpLoc, diag::err_ovl_deleted_oper) 6797 << Best->Function->isDeleted() 6798 << UnaryOperator::getOpcodeStr(Opc) 6799 << Input->getSourceRange(); 6800 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6801 return ExprError(); 6802 } 6803 6804 // Either we found no viable overloaded operator or we matched a 6805 // built-in operator. In either case, fall through to trying to 6806 // build a built-in operation. 6807 return CreateBuiltinUnaryOp(OpLoc, Opc, Input); 6808} 6809 6810/// \brief Create a binary operation that may resolve to an overloaded 6811/// operator. 6812/// 6813/// \param OpLoc The location of the operator itself (e.g., '+'). 6814/// 6815/// \param OpcIn The BinaryOperator::Opcode that describes this 6816/// operator. 6817/// 6818/// \param Functions The set of non-member functions that will be 6819/// considered by overload resolution. The caller needs to build this 6820/// set based on the context using, e.g., 6821/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 6822/// set should not contain any member functions; those will be added 6823/// by CreateOverloadedBinOp(). 6824/// 6825/// \param LHS Left-hand argument. 6826/// \param RHS Right-hand argument. 6827Sema::OwningExprResult 6828Sema::CreateOverloadedBinOp(SourceLocation OpLoc, 6829 unsigned OpcIn, 6830 const UnresolvedSetImpl &Fns, 6831 Expr *LHS, Expr *RHS) { 6832 Expr *Args[2] = { LHS, RHS }; 6833 LHS=RHS=0; //Please use only Args instead of LHS/RHS couple 6834 6835 BinaryOperator::Opcode Opc = static_cast<BinaryOperator::Opcode>(OpcIn); 6836 OverloadedOperatorKind Op = BinaryOperator::getOverloadedOperator(Opc); 6837 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 6838 6839 // If either side is type-dependent, create an appropriate dependent 6840 // expression. 6841 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 6842 if (Fns.empty()) { 6843 // If there are no functions to store, just build a dependent 6844 // BinaryOperator or CompoundAssignment. 6845 if (Opc <= BinaryOperator::Assign || Opc > BinaryOperator::OrAssign) 6846 return Owned(new (Context) BinaryOperator(Args[0], Args[1], Opc, 6847 Context.DependentTy, OpLoc)); 6848 6849 return Owned(new (Context) CompoundAssignOperator(Args[0], Args[1], Opc, 6850 Context.DependentTy, 6851 Context.DependentTy, 6852 Context.DependentTy, 6853 OpLoc)); 6854 } 6855 6856 // FIXME: save results of ADL from here? 6857 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 6858 // TODO: provide better source location info in DNLoc component. 6859 DeclarationNameInfo OpNameInfo(OpName, OpLoc); 6860 UnresolvedLookupExpr *Fn 6861 = UnresolvedLookupExpr::Create(Context, /*Dependent*/ true, NamingClass, 6862 0, SourceRange(), OpNameInfo, 6863 /*ADL*/ true, IsOverloaded(Fns), 6864 Fns.begin(), Fns.end()); 6865 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 6866 Args, 2, 6867 Context.DependentTy, 6868 OpLoc)); 6869 } 6870 6871 // If this is the .* operator, which is not overloadable, just 6872 // create a built-in binary operator. 6873 if (Opc == BinaryOperator::PtrMemD) 6874 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 6875 6876 // If this is the assignment operator, we only perform overload resolution 6877 // if the left-hand side is a class or enumeration type. This is actually 6878 // a hack. The standard requires that we do overload resolution between the 6879 // various built-in candidates, but as DR507 points out, this can lead to 6880 // problems. So we do it this way, which pretty much follows what GCC does. 6881 // Note that we go the traditional code path for compound assignment forms. 6882 if (Opc==BinaryOperator::Assign && !Args[0]->getType()->isOverloadableType()) 6883 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 6884 6885 // Build an empty overload set. 6886 OverloadCandidateSet CandidateSet(OpLoc); 6887 6888 // Add the candidates from the given function set. 6889 AddFunctionCandidates(Fns, Args, 2, CandidateSet, false); 6890 6891 // Add operator candidates that are member functions. 6892 AddMemberOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 6893 6894 // Add candidates from ADL. 6895 AddArgumentDependentLookupCandidates(OpName, /*Operator*/ true, 6896 Args, 2, 6897 /*ExplicitTemplateArgs*/ 0, 6898 CandidateSet); 6899 6900 // Add builtin operator candidates. 6901 AddBuiltinOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 6902 6903 // Perform overload resolution. 6904 OverloadCandidateSet::iterator Best; 6905 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 6906 case OR_Success: { 6907 // We found a built-in operator or an overloaded operator. 6908 FunctionDecl *FnDecl = Best->Function; 6909 6910 if (FnDecl) { 6911 // We matched an overloaded operator. Build a call to that 6912 // operator. 6913 6914 // Convert the arguments. 6915 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 6916 // Best->Access is only meaningful for class members. 6917 CheckMemberOperatorAccess(OpLoc, Args[0], Args[1], Best->FoundDecl); 6918 6919 OwningExprResult Arg1 6920 = PerformCopyInitialization( 6921 InitializedEntity::InitializeParameter( 6922 FnDecl->getParamDecl(0)), 6923 SourceLocation(), 6924 Owned(Args[1])); 6925 if (Arg1.isInvalid()) 6926 return ExprError(); 6927 6928 if (PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/0, 6929 Best->FoundDecl, Method)) 6930 return ExprError(); 6931 6932 Args[1] = RHS = Arg1.takeAs<Expr>(); 6933 } else { 6934 // Convert the arguments. 6935 OwningExprResult Arg0 6936 = PerformCopyInitialization( 6937 InitializedEntity::InitializeParameter( 6938 FnDecl->getParamDecl(0)), 6939 SourceLocation(), 6940 Owned(Args[0])); 6941 if (Arg0.isInvalid()) 6942 return ExprError(); 6943 6944 OwningExprResult Arg1 6945 = PerformCopyInitialization( 6946 InitializedEntity::InitializeParameter( 6947 FnDecl->getParamDecl(1)), 6948 SourceLocation(), 6949 Owned(Args[1])); 6950 if (Arg1.isInvalid()) 6951 return ExprError(); 6952 Args[0] = LHS = Arg0.takeAs<Expr>(); 6953 Args[1] = RHS = Arg1.takeAs<Expr>(); 6954 } 6955 6956 DiagnoseUseOfDecl(Best->FoundDecl, OpLoc); 6957 6958 // Determine the result type 6959 QualType ResultTy 6960 = FnDecl->getType()->getAs<FunctionType>() 6961 ->getCallResultType(Context); 6962 6963 // Build the actual expression node. 6964 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 6965 OpLoc); 6966 UsualUnaryConversions(FnExpr); 6967 6968 CXXOperatorCallExpr *TheCall = 6969 new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 6970 Args, 2, ResultTy, OpLoc); 6971 6972 if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall, 6973 FnDecl)) 6974 return ExprError(); 6975 6976 return MaybeBindToTemporary(TheCall); 6977 } else { 6978 // We matched a built-in operator. Convert the arguments, then 6979 // break out so that we will build the appropriate built-in 6980 // operator node. 6981 if (PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 6982 Best->Conversions[0], AA_Passing) || 6983 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 6984 Best->Conversions[1], AA_Passing)) 6985 return ExprError(); 6986 6987 break; 6988 } 6989 } 6990 6991 case OR_No_Viable_Function: { 6992 // C++ [over.match.oper]p9: 6993 // If the operator is the operator , [...] and there are no 6994 // viable functions, then the operator is assumed to be the 6995 // built-in operator and interpreted according to clause 5. 6996 if (Opc == BinaryOperator::Comma) 6997 break; 6998 6999 // For class as left operand for assignment or compound assigment operator 7000 // do not fall through to handling in built-in, but report that no overloaded 7001 // assignment operator found 7002 OwningExprResult Result = ExprError(); 7003 if (Args[0]->getType()->isRecordType() && 7004 Opc >= BinaryOperator::Assign && Opc <= BinaryOperator::OrAssign) { 7005 Diag(OpLoc, diag::err_ovl_no_viable_oper) 7006 << BinaryOperator::getOpcodeStr(Opc) 7007 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 7008 } else { 7009 // No viable function; try to create a built-in operation, which will 7010 // produce an error. Then, show the non-viable candidates. 7011 Result = CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 7012 } 7013 assert(Result.isInvalid() && 7014 "C++ binary operator overloading is missing candidates!"); 7015 if (Result.isInvalid()) 7016 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2, 7017 BinaryOperator::getOpcodeStr(Opc), OpLoc); 7018 return move(Result); 7019 } 7020 7021 case OR_Ambiguous: 7022 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 7023 << BinaryOperator::getOpcodeStr(Opc) 7024 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 7025 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, 2, 7026 BinaryOperator::getOpcodeStr(Opc), OpLoc); 7027 return ExprError(); 7028 7029 case OR_Deleted: 7030 Diag(OpLoc, diag::err_ovl_deleted_oper) 7031 << Best->Function->isDeleted() 7032 << BinaryOperator::getOpcodeStr(Opc) 7033 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 7034 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2); 7035 return ExprError(); 7036 } 7037 7038 // We matched a built-in operator; build it. 7039 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 7040} 7041 7042Action::OwningExprResult 7043Sema::CreateOverloadedArraySubscriptExpr(SourceLocation LLoc, 7044 SourceLocation RLoc, 7045 Expr *Base, Expr *Idx) { 7046 Expr *Args[2] = { Base, Idx }; 7047 DeclarationName OpName = 7048 Context.DeclarationNames.getCXXOperatorName(OO_Subscript); 7049 7050 // If either side is type-dependent, create an appropriate dependent 7051 // expression. 7052 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 7053 7054 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 7055 // CHECKME: no 'operator' keyword? 7056 DeclarationNameInfo OpNameInfo(OpName, LLoc); 7057 OpNameInfo.setCXXOperatorNameRange(SourceRange(LLoc, RLoc)); 7058 UnresolvedLookupExpr *Fn 7059 = UnresolvedLookupExpr::Create(Context, /*Dependent*/ true, NamingClass, 7060 0, SourceRange(), OpNameInfo, 7061 /*ADL*/ true, /*Overloaded*/ false, 7062 UnresolvedSetIterator(), 7063 UnresolvedSetIterator()); 7064 // Can't add any actual overloads yet 7065 7066 return Owned(new (Context) CXXOperatorCallExpr(Context, OO_Subscript, Fn, 7067 Args, 2, 7068 Context.DependentTy, 7069 RLoc)); 7070 } 7071 7072 // Build an empty overload set. 7073 OverloadCandidateSet CandidateSet(LLoc); 7074 7075 // Subscript can only be overloaded as a member function. 7076 7077 // Add operator candidates that are member functions. 7078 AddMemberOperatorCandidates(OO_Subscript, LLoc, Args, 2, CandidateSet); 7079 7080 // Add builtin operator candidates. 7081 AddBuiltinOperatorCandidates(OO_Subscript, LLoc, Args, 2, CandidateSet); 7082 7083 // Perform overload resolution. 7084 OverloadCandidateSet::iterator Best; 7085 switch (BestViableFunction(CandidateSet, LLoc, Best)) { 7086 case OR_Success: { 7087 // We found a built-in operator or an overloaded operator. 7088 FunctionDecl *FnDecl = Best->Function; 7089 7090 if (FnDecl) { 7091 // We matched an overloaded operator. Build a call to that 7092 // operator. 7093 7094 CheckMemberOperatorAccess(LLoc, Args[0], Args[1], Best->FoundDecl); 7095 DiagnoseUseOfDecl(Best->FoundDecl, LLoc); 7096 7097 // Convert the arguments. 7098 CXXMethodDecl *Method = cast<CXXMethodDecl>(FnDecl); 7099 if (PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/0, 7100 Best->FoundDecl, Method)) 7101 return ExprError(); 7102 7103 // Convert the arguments. 7104 OwningExprResult InputInit 7105 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 7106 FnDecl->getParamDecl(0)), 7107 SourceLocation(), 7108 Owned(Args[1])); 7109 if (InputInit.isInvalid()) 7110 return ExprError(); 7111 7112 Args[1] = InputInit.takeAs<Expr>(); 7113 7114 // Determine the result type 7115 QualType ResultTy 7116 = FnDecl->getType()->getAs<FunctionType>() 7117 ->getCallResultType(Context); 7118 7119 // Build the actual expression node. 7120 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 7121 LLoc); 7122 UsualUnaryConversions(FnExpr); 7123 7124 CXXOperatorCallExpr *TheCall = 7125 new (Context) CXXOperatorCallExpr(Context, OO_Subscript, 7126 FnExpr, Args, 2, 7127 ResultTy, RLoc); 7128 7129 if (CheckCallReturnType(FnDecl->getResultType(), LLoc, TheCall, 7130 FnDecl)) 7131 return ExprError(); 7132 7133 return MaybeBindToTemporary(TheCall); 7134 } else { 7135 // We matched a built-in operator. Convert the arguments, then 7136 // break out so that we will build the appropriate built-in 7137 // operator node. 7138 if (PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 7139 Best->Conversions[0], AA_Passing) || 7140 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 7141 Best->Conversions[1], AA_Passing)) 7142 return ExprError(); 7143 7144 break; 7145 } 7146 } 7147 7148 case OR_No_Viable_Function: { 7149 if (CandidateSet.empty()) 7150 Diag(LLoc, diag::err_ovl_no_oper) 7151 << Args[0]->getType() << /*subscript*/ 0 7152 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 7153 else 7154 Diag(LLoc, diag::err_ovl_no_viable_subscript) 7155 << Args[0]->getType() 7156 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 7157 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2, 7158 "[]", LLoc); 7159 return ExprError(); 7160 } 7161 7162 case OR_Ambiguous: 7163 Diag(LLoc, diag::err_ovl_ambiguous_oper) 7164 << "[]" << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 7165 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, 2, 7166 "[]", LLoc); 7167 return ExprError(); 7168 7169 case OR_Deleted: 7170 Diag(LLoc, diag::err_ovl_deleted_oper) 7171 << Best->Function->isDeleted() << "[]" 7172 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 7173 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2, 7174 "[]", LLoc); 7175 return ExprError(); 7176 } 7177 7178 // We matched a built-in operator; build it. 7179 return CreateBuiltinArraySubscriptExpr(Args[0], LLoc, 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 CXXMemberCallExpr *TheCall = 7298 new (Context) CXXMemberCallExpr(Context, MemExprE, Args, NumArgs, 7299 Method->getCallResultType(), 7300 RParenLoc); 7301 7302 // Check for a valid return type. 7303 if (CheckCallReturnType(Method->getResultType(), MemExpr->getMemberLoc(), 7304 TheCall, Method)) 7305 return ExprError(); 7306 7307 // Convert the object argument (for a non-static member function call). 7308 // We only need to do this if there was actually an overload; otherwise 7309 // it was done at lookup. 7310 Expr *ObjectArg = MemExpr->getBase(); 7311 if (!Method->isStatic() && 7312 PerformObjectArgumentInitialization(ObjectArg, Qualifier, 7313 FoundDecl, Method)) 7314 return ExprError(); 7315 MemExpr->setBase(ObjectArg); 7316 7317 // Convert the rest of the arguments 7318 const FunctionProtoType *Proto = Method->getType()->getAs<FunctionProtoType>(); 7319 if (ConvertArgumentsForCall(TheCall, MemExpr, Method, Proto, Args, NumArgs, 7320 RParenLoc)) 7321 return ExprError(); 7322 7323 if (CheckFunctionCall(Method, TheCall)) 7324 return ExprError(); 7325 7326 return MaybeBindToTemporary(TheCall); 7327} 7328 7329/// BuildCallToObjectOfClassType - Build a call to an object of class 7330/// type (C++ [over.call.object]), which can end up invoking an 7331/// overloaded function call operator (@c operator()) or performing a 7332/// user-defined conversion on the object argument. 7333Sema::ExprResult 7334Sema::BuildCallToObjectOfClassType(Scope *S, Expr *Object, 7335 SourceLocation LParenLoc, 7336 Expr **Args, unsigned NumArgs, 7337 SourceLocation *CommaLocs, 7338 SourceLocation RParenLoc) { 7339 assert(Object->getType()->isRecordType() && "Requires object type argument"); 7340 const RecordType *Record = Object->getType()->getAs<RecordType>(); 7341 7342 // C++ [over.call.object]p1: 7343 // If the primary-expression E in the function call syntax 7344 // evaluates to a class object of type "cv T", then the set of 7345 // candidate functions includes at least the function call 7346 // operators of T. The function call operators of T are obtained by 7347 // ordinary lookup of the name operator() in the context of 7348 // (E).operator(). 7349 OverloadCandidateSet CandidateSet(LParenLoc); 7350 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Call); 7351 7352 if (RequireCompleteType(LParenLoc, Object->getType(), 7353 PDiag(diag::err_incomplete_object_call) 7354 << Object->getSourceRange())) 7355 return true; 7356 7357 LookupResult R(*this, OpName, LParenLoc, LookupOrdinaryName); 7358 LookupQualifiedName(R, Record->getDecl()); 7359 R.suppressDiagnostics(); 7360 7361 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 7362 Oper != OperEnd; ++Oper) { 7363 AddMethodCandidate(Oper.getPair(), Object->getType(), 7364 Args, NumArgs, CandidateSet, 7365 /*SuppressUserConversions=*/ false); 7366 } 7367 7368 // C++ [over.call.object]p2: 7369 // In addition, for each conversion function declared in T of the 7370 // form 7371 // 7372 // operator conversion-type-id () cv-qualifier; 7373 // 7374 // where cv-qualifier is the same cv-qualification as, or a 7375 // greater cv-qualification than, cv, and where conversion-type-id 7376 // denotes the type "pointer to function of (P1,...,Pn) returning 7377 // R", or the type "reference to pointer to function of 7378 // (P1,...,Pn) returning R", or the type "reference to function 7379 // of (P1,...,Pn) returning R", a surrogate call function [...] 7380 // is also considered as a candidate function. Similarly, 7381 // surrogate call functions are added to the set of candidate 7382 // functions for each conversion function declared in an 7383 // accessible base class provided the function is not hidden 7384 // within T by another intervening declaration. 7385 const UnresolvedSetImpl *Conversions 7386 = cast<CXXRecordDecl>(Record->getDecl())->getVisibleConversionFunctions(); 7387 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 7388 E = Conversions->end(); I != E; ++I) { 7389 NamedDecl *D = *I; 7390 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext()); 7391 if (isa<UsingShadowDecl>(D)) 7392 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 7393 7394 // Skip over templated conversion functions; they aren't 7395 // surrogates. 7396 if (isa<FunctionTemplateDecl>(D)) 7397 continue; 7398 7399 CXXConversionDecl *Conv = cast<CXXConversionDecl>(D); 7400 7401 // Strip the reference type (if any) and then the pointer type (if 7402 // any) to get down to what might be a function type. 7403 QualType ConvType = Conv->getConversionType().getNonReferenceType(); 7404 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 7405 ConvType = ConvPtrType->getPointeeType(); 7406 7407 if (const FunctionProtoType *Proto = ConvType->getAs<FunctionProtoType>()) 7408 AddSurrogateCandidate(Conv, I.getPair(), ActingContext, Proto, 7409 Object->getType(), Args, NumArgs, 7410 CandidateSet); 7411 } 7412 7413 // Perform overload resolution. 7414 OverloadCandidateSet::iterator Best; 7415 switch (BestViableFunction(CandidateSet, Object->getLocStart(), Best)) { 7416 case OR_Success: 7417 // Overload resolution succeeded; we'll build the appropriate call 7418 // below. 7419 break; 7420 7421 case OR_No_Viable_Function: 7422 if (CandidateSet.empty()) 7423 Diag(Object->getSourceRange().getBegin(), diag::err_ovl_no_oper) 7424 << Object->getType() << /*call*/ 1 7425 << Object->getSourceRange(); 7426 else 7427 Diag(Object->getSourceRange().getBegin(), 7428 diag::err_ovl_no_viable_object_call) 7429 << Object->getType() << Object->getSourceRange(); 7430 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 7431 break; 7432 7433 case OR_Ambiguous: 7434 Diag(Object->getSourceRange().getBegin(), 7435 diag::err_ovl_ambiguous_object_call) 7436 << Object->getType() << Object->getSourceRange(); 7437 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, NumArgs); 7438 break; 7439 7440 case OR_Deleted: 7441 Diag(Object->getSourceRange().getBegin(), 7442 diag::err_ovl_deleted_object_call) 7443 << Best->Function->isDeleted() 7444 << Object->getType() << Object->getSourceRange(); 7445 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 7446 break; 7447 } 7448 7449 if (Best == CandidateSet.end()) 7450 return true; 7451 7452 if (Best->Function == 0) { 7453 // Since there is no function declaration, this is one of the 7454 // surrogate candidates. Dig out the conversion function. 7455 CXXConversionDecl *Conv 7456 = cast<CXXConversionDecl>( 7457 Best->Conversions[0].UserDefined.ConversionFunction); 7458 7459 CheckMemberOperatorAccess(LParenLoc, Object, 0, Best->FoundDecl); 7460 DiagnoseUseOfDecl(Best->FoundDecl, LParenLoc); 7461 7462 // We selected one of the surrogate functions that converts the 7463 // object parameter to a function pointer. Perform the conversion 7464 // on the object argument, then let ActOnCallExpr finish the job. 7465 7466 // Create an implicit member expr to refer to the conversion operator. 7467 // and then call it. 7468 CXXMemberCallExpr *CE = BuildCXXMemberCallExpr(Object, Best->FoundDecl, 7469 Conv); 7470 7471 return ActOnCallExpr(S, CE, LParenLoc, 7472 MultiExprArg(*this, (ExprTy**)Args, NumArgs), 7473 CommaLocs, RParenLoc).result(); 7474 } 7475 7476 CheckMemberOperatorAccess(LParenLoc, Object, 0, Best->FoundDecl); 7477 DiagnoseUseOfDecl(Best->FoundDecl, LParenLoc); 7478 7479 // We found an overloaded operator(). Build a CXXOperatorCallExpr 7480 // that calls this method, using Object for the implicit object 7481 // parameter and passing along the remaining arguments. 7482 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 7483 const FunctionProtoType *Proto = Method->getType()->getAs<FunctionProtoType>(); 7484 7485 unsigned NumArgsInProto = Proto->getNumArgs(); 7486 unsigned NumArgsToCheck = NumArgs; 7487 7488 // Build the full argument list for the method call (the 7489 // implicit object parameter is placed at the beginning of the 7490 // list). 7491 Expr **MethodArgs; 7492 if (NumArgs < NumArgsInProto) { 7493 NumArgsToCheck = NumArgsInProto; 7494 MethodArgs = new Expr*[NumArgsInProto + 1]; 7495 } else { 7496 MethodArgs = new Expr*[NumArgs + 1]; 7497 } 7498 MethodArgs[0] = Object; 7499 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 7500 MethodArgs[ArgIdx + 1] = Args[ArgIdx]; 7501 7502 Expr *NewFn = new (Context) DeclRefExpr(Method, Method->getType(), 7503 SourceLocation()); 7504 UsualUnaryConversions(NewFn); 7505 7506 // Once we've built TheCall, all of the expressions are properly 7507 // owned. 7508 QualType ResultTy = Method->getCallResultType(); 7509 CXXOperatorCallExpr *TheCall = 7510 new (Context) CXXOperatorCallExpr(Context, OO_Call, NewFn, 7511 MethodArgs, NumArgs + 1, 7512 ResultTy, RParenLoc); 7513 delete [] MethodArgs; 7514 7515 if (CheckCallReturnType(Method->getResultType(), LParenLoc, TheCall, 7516 Method)) 7517 return true; 7518 7519 // We may have default arguments. If so, we need to allocate more 7520 // slots in the call for them. 7521 if (NumArgs < NumArgsInProto) 7522 TheCall->setNumArgs(Context, NumArgsInProto + 1); 7523 else if (NumArgs > NumArgsInProto) 7524 NumArgsToCheck = NumArgsInProto; 7525 7526 bool IsError = false; 7527 7528 // Initialize the implicit object parameter. 7529 IsError |= PerformObjectArgumentInitialization(Object, /*Qualifier=*/0, 7530 Best->FoundDecl, Method); 7531 TheCall->setArg(0, Object); 7532 7533 7534 // Check the argument types. 7535 for (unsigned i = 0; i != NumArgsToCheck; i++) { 7536 Expr *Arg; 7537 if (i < NumArgs) { 7538 Arg = Args[i]; 7539 7540 // Pass the argument. 7541 7542 OwningExprResult InputInit 7543 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 7544 Method->getParamDecl(i)), 7545 SourceLocation(), Arg); 7546 7547 IsError |= InputInit.isInvalid(); 7548 Arg = InputInit.takeAs<Expr>(); 7549 } else { 7550 OwningExprResult DefArg 7551 = BuildCXXDefaultArgExpr(LParenLoc, Method, Method->getParamDecl(i)); 7552 if (DefArg.isInvalid()) { 7553 IsError = true; 7554 break; 7555 } 7556 7557 Arg = DefArg.takeAs<Expr>(); 7558 } 7559 7560 TheCall->setArg(i + 1, Arg); 7561 } 7562 7563 // If this is a variadic call, handle args passed through "...". 7564 if (Proto->isVariadic()) { 7565 // Promote the arguments (C99 6.5.2.2p7). 7566 for (unsigned i = NumArgsInProto; i != NumArgs; i++) { 7567 Expr *Arg = Args[i]; 7568 IsError |= DefaultVariadicArgumentPromotion(Arg, VariadicMethod, 0); 7569 TheCall->setArg(i + 1, Arg); 7570 } 7571 } 7572 7573 if (IsError) return true; 7574 7575 if (CheckFunctionCall(Method, TheCall)) 7576 return true; 7577 7578 return MaybeBindToTemporary(TheCall).result(); 7579} 7580 7581/// BuildOverloadedArrowExpr - Build a call to an overloaded @c operator-> 7582/// (if one exists), where @c Base is an expression of class type and 7583/// @c Member is the name of the member we're trying to find. 7584Sema::OwningExprResult 7585Sema::BuildOverloadedArrowExpr(Scope *S, Expr *Base, SourceLocation OpLoc) { 7586 assert(Base->getType()->isRecordType() && "left-hand side must have class type"); 7587 7588 SourceLocation Loc = Base->getExprLoc(); 7589 7590 // C++ [over.ref]p1: 7591 // 7592 // [...] An expression x->m is interpreted as (x.operator->())->m 7593 // for a class object x of type T if T::operator->() exists and if 7594 // the operator is selected as the best match function by the 7595 // overload resolution mechanism (13.3). 7596 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Arrow); 7597 OverloadCandidateSet CandidateSet(Loc); 7598 const RecordType *BaseRecord = Base->getType()->getAs<RecordType>(); 7599 7600 if (RequireCompleteType(Loc, Base->getType(), 7601 PDiag(diag::err_typecheck_incomplete_tag) 7602 << Base->getSourceRange())) 7603 return ExprError(); 7604 7605 LookupResult R(*this, OpName, OpLoc, LookupOrdinaryName); 7606 LookupQualifiedName(R, BaseRecord->getDecl()); 7607 R.suppressDiagnostics(); 7608 7609 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 7610 Oper != OperEnd; ++Oper) { 7611 AddMethodCandidate(Oper.getPair(), Base->getType(), 0, 0, CandidateSet, 7612 /*SuppressUserConversions=*/false); 7613 } 7614 7615 // Perform overload resolution. 7616 OverloadCandidateSet::iterator Best; 7617 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 7618 case OR_Success: 7619 // Overload resolution succeeded; we'll build the call below. 7620 break; 7621 7622 case OR_No_Viable_Function: 7623 if (CandidateSet.empty()) 7624 Diag(OpLoc, diag::err_typecheck_member_reference_arrow) 7625 << Base->getType() << Base->getSourceRange(); 7626 else 7627 Diag(OpLoc, diag::err_ovl_no_viable_oper) 7628 << "operator->" << Base->getSourceRange(); 7629 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, &Base, 1); 7630 return ExprError(); 7631 7632 case OR_Ambiguous: 7633 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 7634 << "->" << Base->getSourceRange(); 7635 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, &Base, 1); 7636 return ExprError(); 7637 7638 case OR_Deleted: 7639 Diag(OpLoc, diag::err_ovl_deleted_oper) 7640 << Best->Function->isDeleted() 7641 << "->" << Base->getSourceRange(); 7642 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, &Base, 1); 7643 return ExprError(); 7644 } 7645 7646 CheckMemberOperatorAccess(OpLoc, Base, 0, Best->FoundDecl); 7647 DiagnoseUseOfDecl(Best->FoundDecl, OpLoc); 7648 7649 // Convert the object parameter. 7650 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 7651 if (PerformObjectArgumentInitialization(Base, /*Qualifier=*/0, 7652 Best->FoundDecl, Method)) 7653 return ExprError(); 7654 7655 // Build the operator call. 7656 Expr *FnExpr = new (Context) DeclRefExpr(Method, Method->getType(), 7657 SourceLocation()); 7658 UsualUnaryConversions(FnExpr); 7659 7660 QualType ResultTy = Method->getCallResultType(); 7661 CXXOperatorCallExpr *TheCall = 7662 new (Context) CXXOperatorCallExpr(Context, OO_Arrow, FnExpr, 7663 &Base, 1, ResultTy, OpLoc); 7664 7665 if (CheckCallReturnType(Method->getResultType(), OpLoc, TheCall, 7666 Method)) 7667 return ExprError(); 7668 return Owned(TheCall); 7669} 7670 7671/// FixOverloadedFunctionReference - E is an expression that refers to 7672/// a C++ overloaded function (possibly with some parentheses and 7673/// perhaps a '&' around it). We have resolved the overloaded function 7674/// to the function declaration Fn, so patch up the expression E to 7675/// refer (possibly indirectly) to Fn. Returns the new expr. 7676Expr *Sema::FixOverloadedFunctionReference(Expr *E, DeclAccessPair Found, 7677 FunctionDecl *Fn) { 7678 if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) { 7679 Expr *SubExpr = FixOverloadedFunctionReference(PE->getSubExpr(), 7680 Found, Fn); 7681 if (SubExpr == PE->getSubExpr()) 7682 return PE->Retain(); 7683 7684 return new (Context) ParenExpr(PE->getLParen(), PE->getRParen(), SubExpr); 7685 } 7686 7687 if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) { 7688 Expr *SubExpr = FixOverloadedFunctionReference(ICE->getSubExpr(), 7689 Found, Fn); 7690 assert(Context.hasSameType(ICE->getSubExpr()->getType(), 7691 SubExpr->getType()) && 7692 "Implicit cast type cannot be determined from overload"); 7693 assert(ICE->path_empty() && "fixing up hierarchy conversion?"); 7694 if (SubExpr == ICE->getSubExpr()) 7695 return ICE->Retain(); 7696 7697 return ImplicitCastExpr::Create(Context, ICE->getType(), 7698 ICE->getCastKind(), 7699 SubExpr, 0, 7700 ICE->getCategory()); 7701 } 7702 7703 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(E)) { 7704 assert(UnOp->getOpcode() == UnaryOperator::AddrOf && 7705 "Can only take the address of an overloaded function"); 7706 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 7707 if (Method->isStatic()) { 7708 // Do nothing: static member functions aren't any different 7709 // from non-member functions. 7710 } else { 7711 // Fix the sub expression, which really has to be an 7712 // UnresolvedLookupExpr holding an overloaded member function 7713 // or template. 7714 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(), 7715 Found, Fn); 7716 if (SubExpr == UnOp->getSubExpr()) 7717 return UnOp->Retain(); 7718 7719 assert(isa<DeclRefExpr>(SubExpr) 7720 && "fixed to something other than a decl ref"); 7721 assert(cast<DeclRefExpr>(SubExpr)->getQualifier() 7722 && "fixed to a member ref with no nested name qualifier"); 7723 7724 // We have taken the address of a pointer to member 7725 // function. Perform the computation here so that we get the 7726 // appropriate pointer to member type. 7727 QualType ClassType 7728 = Context.getTypeDeclType(cast<RecordDecl>(Method->getDeclContext())); 7729 QualType MemPtrType 7730 = Context.getMemberPointerType(Fn->getType(), ClassType.getTypePtr()); 7731 7732 return new (Context) UnaryOperator(SubExpr, UnaryOperator::AddrOf, 7733 MemPtrType, UnOp->getOperatorLoc()); 7734 } 7735 } 7736 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(), 7737 Found, Fn); 7738 if (SubExpr == UnOp->getSubExpr()) 7739 return UnOp->Retain(); 7740 7741 return new (Context) UnaryOperator(SubExpr, UnaryOperator::AddrOf, 7742 Context.getPointerType(SubExpr->getType()), 7743 UnOp->getOperatorLoc()); 7744 } 7745 7746 if (UnresolvedLookupExpr *ULE = dyn_cast<UnresolvedLookupExpr>(E)) { 7747 // FIXME: avoid copy. 7748 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 7749 if (ULE->hasExplicitTemplateArgs()) { 7750 ULE->copyTemplateArgumentsInto(TemplateArgsBuffer); 7751 TemplateArgs = &TemplateArgsBuffer; 7752 } 7753 7754 return DeclRefExpr::Create(Context, 7755 ULE->getQualifier(), 7756 ULE->getQualifierRange(), 7757 Fn, 7758 ULE->getNameLoc(), 7759 Fn->getType(), 7760 TemplateArgs); 7761 } 7762 7763 if (UnresolvedMemberExpr *MemExpr = dyn_cast<UnresolvedMemberExpr>(E)) { 7764 // FIXME: avoid copy. 7765 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 7766 if (MemExpr->hasExplicitTemplateArgs()) { 7767 MemExpr->copyTemplateArgumentsInto(TemplateArgsBuffer); 7768 TemplateArgs = &TemplateArgsBuffer; 7769 } 7770 7771 Expr *Base; 7772 7773 // If we're filling in 7774 if (MemExpr->isImplicitAccess()) { 7775 if (cast<CXXMethodDecl>(Fn)->isStatic()) { 7776 return DeclRefExpr::Create(Context, 7777 MemExpr->getQualifier(), 7778 MemExpr->getQualifierRange(), 7779 Fn, 7780 MemExpr->getMemberLoc(), 7781 Fn->getType(), 7782 TemplateArgs); 7783 } else { 7784 SourceLocation Loc = MemExpr->getMemberLoc(); 7785 if (MemExpr->getQualifier()) 7786 Loc = MemExpr->getQualifierRange().getBegin(); 7787 Base = new (Context) CXXThisExpr(Loc, 7788 MemExpr->getBaseType(), 7789 /*isImplicit=*/true); 7790 } 7791 } else 7792 Base = MemExpr->getBase()->Retain(); 7793 7794 return MemberExpr::Create(Context, Base, 7795 MemExpr->isArrow(), 7796 MemExpr->getQualifier(), 7797 MemExpr->getQualifierRange(), 7798 Fn, 7799 Found, 7800 MemExpr->getMemberNameInfo(), 7801 TemplateArgs, 7802 Fn->getType()); 7803 } 7804 7805 assert(false && "Invalid reference to overloaded function"); 7806 return E->Retain(); 7807} 7808 7809Sema::OwningExprResult Sema::FixOverloadedFunctionReference(OwningExprResult E, 7810 DeclAccessPair Found, 7811 FunctionDecl *Fn) { 7812 return Owned(FixOverloadedFunctionReference((Expr *)E.get(), Found, Fn)); 7813} 7814 7815} // end namespace clang 7816