SemaOverload.cpp revision ad517574c8fe0250e3eca1fa10c596bfebfbe099
1//===--- SemaOverload.cpp - C++ Overloading ---------------------*- C++ -*-===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This file provides Sema routines for C++ overloading. 11// 12//===----------------------------------------------------------------------===// 13 14#include "Sema.h" 15#include "Lookup.h" 16#include "SemaInit.h" 17#include "clang/Basic/Diagnostic.h" 18#include "clang/Lex/Preprocessor.h" 19#include "clang/AST/ASTContext.h" 20#include "clang/AST/CXXInheritance.h" 21#include "clang/AST/Expr.h" 22#include "clang/AST/ExprCXX.h" 23#include "clang/AST/TypeOrdering.h" 24#include "clang/Basic/PartialDiagnostic.h" 25#include "llvm/ADT/SmallPtrSet.h" 26#include "llvm/ADT/STLExtras.h" 27#include <algorithm> 28 29namespace clang { 30 31/// GetConversionCategory - Retrieve the implicit conversion 32/// category corresponding to the given implicit conversion kind. 33ImplicitConversionCategory 34GetConversionCategory(ImplicitConversionKind Kind) { 35 static const ImplicitConversionCategory 36 Category[(int)ICK_Num_Conversion_Kinds] = { 37 ICC_Identity, 38 ICC_Lvalue_Transformation, 39 ICC_Lvalue_Transformation, 40 ICC_Lvalue_Transformation, 41 ICC_Identity, 42 ICC_Qualification_Adjustment, 43 ICC_Promotion, 44 ICC_Promotion, 45 ICC_Promotion, 46 ICC_Conversion, 47 ICC_Conversion, 48 ICC_Conversion, 49 ICC_Conversion, 50 ICC_Conversion, 51 ICC_Conversion, 52 ICC_Conversion, 53 ICC_Conversion, 54 ICC_Conversion, 55 ICC_Conversion 56 }; 57 return Category[(int)Kind]; 58} 59 60/// GetConversionRank - Retrieve the implicit conversion rank 61/// corresponding to the given implicit conversion kind. 62ImplicitConversionRank GetConversionRank(ImplicitConversionKind Kind) { 63 static const ImplicitConversionRank 64 Rank[(int)ICK_Num_Conversion_Kinds] = { 65 ICR_Exact_Match, 66 ICR_Exact_Match, 67 ICR_Exact_Match, 68 ICR_Exact_Match, 69 ICR_Exact_Match, 70 ICR_Exact_Match, 71 ICR_Promotion, 72 ICR_Promotion, 73 ICR_Promotion, 74 ICR_Conversion, 75 ICR_Conversion, 76 ICR_Conversion, 77 ICR_Conversion, 78 ICR_Conversion, 79 ICR_Conversion, 80 ICR_Conversion, 81 ICR_Conversion, 82 ICR_Conversion, 83 ICR_Complex_Real_Conversion 84 }; 85 return Rank[(int)Kind]; 86} 87 88/// GetImplicitConversionName - Return the name of this kind of 89/// implicit conversion. 90const char* GetImplicitConversionName(ImplicitConversionKind Kind) { 91 static const char* const Name[(int)ICK_Num_Conversion_Kinds] = { 92 "No conversion", 93 "Lvalue-to-rvalue", 94 "Array-to-pointer", 95 "Function-to-pointer", 96 "Noreturn adjustment", 97 "Qualification", 98 "Integral promotion", 99 "Floating point promotion", 100 "Complex promotion", 101 "Integral conversion", 102 "Floating conversion", 103 "Complex conversion", 104 "Floating-integral conversion", 105 "Complex-real conversion", 106 "Pointer conversion", 107 "Pointer-to-member conversion", 108 "Boolean conversion", 109 "Compatible-types conversion", 110 "Derived-to-base conversion" 111 }; 112 return Name[Kind]; 113} 114 115/// StandardConversionSequence - Set the standard conversion 116/// sequence to the identity conversion. 117void StandardConversionSequence::setAsIdentityConversion() { 118 First = ICK_Identity; 119 Second = ICK_Identity; 120 Third = ICK_Identity; 121 DeprecatedStringLiteralToCharPtr = false; 122 ReferenceBinding = false; 123 DirectBinding = false; 124 RRefBinding = false; 125 CopyConstructor = 0; 126} 127 128/// getRank - Retrieve the rank of this standard conversion sequence 129/// (C++ 13.3.3.1.1p3). The rank is the largest rank of each of the 130/// implicit conversions. 131ImplicitConversionRank StandardConversionSequence::getRank() const { 132 ImplicitConversionRank Rank = ICR_Exact_Match; 133 if (GetConversionRank(First) > Rank) 134 Rank = GetConversionRank(First); 135 if (GetConversionRank(Second) > Rank) 136 Rank = GetConversionRank(Second); 137 if (GetConversionRank(Third) > Rank) 138 Rank = GetConversionRank(Third); 139 return Rank; 140} 141 142/// isPointerConversionToBool - Determines whether this conversion is 143/// a conversion of a pointer or pointer-to-member to bool. This is 144/// used as part of the ranking of standard conversion sequences 145/// (C++ 13.3.3.2p4). 146bool StandardConversionSequence::isPointerConversionToBool() const { 147 // Note that FromType has not necessarily been transformed by the 148 // array-to-pointer or function-to-pointer implicit conversions, so 149 // check for their presence as well as checking whether FromType is 150 // a pointer. 151 if (getToType(1)->isBooleanType() && 152 (getFromType()->isPointerType() || getFromType()->isBlockPointerType() || 153 First == ICK_Array_To_Pointer || First == ICK_Function_To_Pointer)) 154 return true; 155 156 return false; 157} 158 159/// isPointerConversionToVoidPointer - Determines whether this 160/// conversion is a conversion of a pointer to a void pointer. This is 161/// used as part of the ranking of standard conversion sequences (C++ 162/// 13.3.3.2p4). 163bool 164StandardConversionSequence:: 165isPointerConversionToVoidPointer(ASTContext& Context) const { 166 QualType FromType = getFromType(); 167 QualType ToType = getToType(1); 168 169 // Note that FromType has not necessarily been transformed by the 170 // array-to-pointer implicit conversion, so check for its presence 171 // and redo the conversion to get a pointer. 172 if (First == ICK_Array_To_Pointer) 173 FromType = Context.getArrayDecayedType(FromType); 174 175 if (Second == ICK_Pointer_Conversion && FromType->isPointerType()) 176 if (const PointerType* ToPtrType = ToType->getAs<PointerType>()) 177 return ToPtrType->getPointeeType()->isVoidType(); 178 179 return false; 180} 181 182/// DebugPrint - Print this standard conversion sequence to standard 183/// error. Useful for debugging overloading issues. 184void StandardConversionSequence::DebugPrint() const { 185 llvm::raw_ostream &OS = llvm::errs(); 186 bool PrintedSomething = false; 187 if (First != ICK_Identity) { 188 OS << GetImplicitConversionName(First); 189 PrintedSomething = true; 190 } 191 192 if (Second != ICK_Identity) { 193 if (PrintedSomething) { 194 OS << " -> "; 195 } 196 OS << GetImplicitConversionName(Second); 197 198 if (CopyConstructor) { 199 OS << " (by copy constructor)"; 200 } else if (DirectBinding) { 201 OS << " (direct reference binding)"; 202 } else if (ReferenceBinding) { 203 OS << " (reference binding)"; 204 } 205 PrintedSomething = true; 206 } 207 208 if (Third != ICK_Identity) { 209 if (PrintedSomething) { 210 OS << " -> "; 211 } 212 OS << GetImplicitConversionName(Third); 213 PrintedSomething = true; 214 } 215 216 if (!PrintedSomething) { 217 OS << "No conversions required"; 218 } 219} 220 221/// DebugPrint - Print this user-defined conversion sequence to standard 222/// error. Useful for debugging overloading issues. 223void UserDefinedConversionSequence::DebugPrint() const { 224 llvm::raw_ostream &OS = llvm::errs(); 225 if (Before.First || Before.Second || Before.Third) { 226 Before.DebugPrint(); 227 OS << " -> "; 228 } 229 OS << '\'' << ConversionFunction << '\''; 230 if (After.First || After.Second || After.Third) { 231 OS << " -> "; 232 After.DebugPrint(); 233 } 234} 235 236/// DebugPrint - Print this implicit conversion sequence to standard 237/// error. Useful for debugging overloading issues. 238void ImplicitConversionSequence::DebugPrint() const { 239 llvm::raw_ostream &OS = llvm::errs(); 240 switch (ConversionKind) { 241 case StandardConversion: 242 OS << "Standard conversion: "; 243 Standard.DebugPrint(); 244 break; 245 case UserDefinedConversion: 246 OS << "User-defined conversion: "; 247 UserDefined.DebugPrint(); 248 break; 249 case EllipsisConversion: 250 OS << "Ellipsis conversion"; 251 break; 252 case AmbiguousConversion: 253 OS << "Ambiguous conversion"; 254 break; 255 case BadConversion: 256 OS << "Bad conversion"; 257 break; 258 } 259 260 OS << "\n"; 261} 262 263void AmbiguousConversionSequence::construct() { 264 new (&conversions()) ConversionSet(); 265} 266 267void AmbiguousConversionSequence::destruct() { 268 conversions().~ConversionSet(); 269} 270 271void 272AmbiguousConversionSequence::copyFrom(const AmbiguousConversionSequence &O) { 273 FromTypePtr = O.FromTypePtr; 274 ToTypePtr = O.ToTypePtr; 275 new (&conversions()) ConversionSet(O.conversions()); 276} 277 278 279// IsOverload - Determine whether the given New declaration is an 280// overload of the declarations in Old. This routine returns false if 281// New and Old cannot be overloaded, e.g., if New has the same 282// signature as some function in Old (C++ 1.3.10) or if the Old 283// declarations aren't functions (or function templates) at all. When 284// it does return false, MatchedDecl will point to the decl that New 285// cannot be overloaded with. This decl may be a UsingShadowDecl on 286// top of the underlying declaration. 287// 288// Example: Given the following input: 289// 290// void f(int, float); // #1 291// void f(int, int); // #2 292// int f(int, int); // #3 293// 294// When we process #1, there is no previous declaration of "f", 295// so IsOverload will not be used. 296// 297// When we process #2, Old contains only the FunctionDecl for #1. By 298// comparing the parameter types, we see that #1 and #2 are overloaded 299// (since they have different signatures), so this routine returns 300// false; MatchedDecl is unchanged. 301// 302// When we process #3, Old is an overload set containing #1 and #2. We 303// compare the signatures of #3 to #1 (they're overloaded, so we do 304// nothing) and then #3 to #2. Since the signatures of #3 and #2 are 305// identical (return types of functions are not part of the 306// signature), IsOverload returns false and MatchedDecl will be set to 307// point to the FunctionDecl for #2. 308Sema::OverloadKind 309Sema::CheckOverload(FunctionDecl *New, const LookupResult &Old, 310 NamedDecl *&Match) { 311 for (LookupResult::iterator I = Old.begin(), E = Old.end(); 312 I != E; ++I) { 313 NamedDecl *OldD = (*I)->getUnderlyingDecl(); 314 if (FunctionTemplateDecl *OldT = dyn_cast<FunctionTemplateDecl>(OldD)) { 315 if (!IsOverload(New, OldT->getTemplatedDecl())) { 316 Match = *I; 317 return Ovl_Match; 318 } 319 } else if (FunctionDecl *OldF = dyn_cast<FunctionDecl>(OldD)) { 320 if (!IsOverload(New, OldF)) { 321 Match = *I; 322 return Ovl_Match; 323 } 324 } else if (isa<UsingDecl>(OldD) || isa<TagDecl>(OldD)) { 325 // We can overload with these, which can show up when doing 326 // redeclaration checks for UsingDecls. 327 assert(Old.getLookupKind() == LookupUsingDeclName); 328 } else if (isa<UnresolvedUsingValueDecl>(OldD)) { 329 // Optimistically assume that an unresolved using decl will 330 // overload; if it doesn't, we'll have to diagnose during 331 // template instantiation. 332 } else { 333 // (C++ 13p1): 334 // Only function declarations can be overloaded; object and type 335 // declarations cannot be overloaded. 336 Match = *I; 337 return Ovl_NonFunction; 338 } 339 } 340 341 return Ovl_Overload; 342} 343 344bool Sema::IsOverload(FunctionDecl *New, FunctionDecl *Old) { 345 FunctionTemplateDecl *OldTemplate = Old->getDescribedFunctionTemplate(); 346 FunctionTemplateDecl *NewTemplate = New->getDescribedFunctionTemplate(); 347 348 // C++ [temp.fct]p2: 349 // A function template can be overloaded with other function templates 350 // and with normal (non-template) functions. 351 if ((OldTemplate == 0) != (NewTemplate == 0)) 352 return true; 353 354 // Is the function New an overload of the function Old? 355 QualType OldQType = Context.getCanonicalType(Old->getType()); 356 QualType NewQType = Context.getCanonicalType(New->getType()); 357 358 // Compare the signatures (C++ 1.3.10) of the two functions to 359 // determine whether they are overloads. If we find any mismatch 360 // in the signature, they are overloads. 361 362 // If either of these functions is a K&R-style function (no 363 // prototype), then we consider them to have matching signatures. 364 if (isa<FunctionNoProtoType>(OldQType.getTypePtr()) || 365 isa<FunctionNoProtoType>(NewQType.getTypePtr())) 366 return false; 367 368 FunctionProtoType* OldType = cast<FunctionProtoType>(OldQType); 369 FunctionProtoType* NewType = cast<FunctionProtoType>(NewQType); 370 371 // The signature of a function includes the types of its 372 // parameters (C++ 1.3.10), which includes the presence or absence 373 // of the ellipsis; see C++ DR 357). 374 if (OldQType != NewQType && 375 (OldType->getNumArgs() != NewType->getNumArgs() || 376 OldType->isVariadic() != NewType->isVariadic() || 377 !FunctionArgTypesAreEqual(OldType, NewType))) 378 return true; 379 380 // C++ [temp.over.link]p4: 381 // The signature of a function template consists of its function 382 // signature, its return type and its template parameter list. The names 383 // of the template parameters are significant only for establishing the 384 // relationship between the template parameters and the rest of the 385 // signature. 386 // 387 // We check the return type and template parameter lists for function 388 // templates first; the remaining checks follow. 389 if (NewTemplate && 390 (!TemplateParameterListsAreEqual(NewTemplate->getTemplateParameters(), 391 OldTemplate->getTemplateParameters(), 392 false, TPL_TemplateMatch) || 393 OldType->getResultType() != NewType->getResultType())) 394 return true; 395 396 // If the function is a class member, its signature includes the 397 // cv-qualifiers (if any) on the function itself. 398 // 399 // As part of this, also check whether one of the member functions 400 // is static, in which case they are not overloads (C++ 401 // 13.1p2). While not part of the definition of the signature, 402 // this check is important to determine whether these functions 403 // can be overloaded. 404 CXXMethodDecl* OldMethod = dyn_cast<CXXMethodDecl>(Old); 405 CXXMethodDecl* NewMethod = dyn_cast<CXXMethodDecl>(New); 406 if (OldMethod && NewMethod && 407 !OldMethod->isStatic() && !NewMethod->isStatic() && 408 OldMethod->getTypeQualifiers() != NewMethod->getTypeQualifiers()) 409 return true; 410 411 // The signatures match; this is not an overload. 412 return false; 413} 414 415/// TryImplicitConversion - Attempt to perform an implicit conversion 416/// from the given expression (Expr) to the given type (ToType). This 417/// function returns an implicit conversion sequence that can be used 418/// to perform the initialization. Given 419/// 420/// void f(float f); 421/// void g(int i) { f(i); } 422/// 423/// this routine would produce an implicit conversion sequence to 424/// describe the initialization of f from i, which will be a standard 425/// conversion sequence containing an lvalue-to-rvalue conversion (C++ 426/// 4.1) followed by a floating-integral conversion (C++ 4.9). 427// 428/// Note that this routine only determines how the conversion can be 429/// performed; it does not actually perform the conversion. As such, 430/// it will not produce any diagnostics if no conversion is available, 431/// but will instead return an implicit conversion sequence of kind 432/// "BadConversion". 433/// 434/// If @p SuppressUserConversions, then user-defined conversions are 435/// not permitted. 436/// If @p AllowExplicit, then explicit user-defined conversions are 437/// permitted. 438ImplicitConversionSequence 439Sema::TryImplicitConversion(Expr* From, QualType ToType, 440 bool SuppressUserConversions, 441 bool AllowExplicit, 442 bool InOverloadResolution) { 443 ImplicitConversionSequence ICS; 444 if (IsStandardConversion(From, ToType, InOverloadResolution, ICS.Standard)) { 445 ICS.setStandard(); 446 return ICS; 447 } 448 449 if (!getLangOptions().CPlusPlus) { 450 ICS.setBad(BadConversionSequence::no_conversion, From, ToType); 451 return ICS; 452 } 453 454 if (SuppressUserConversions) { 455 // C++ [over.ics.user]p4: 456 // A conversion of an expression of class type to the same class 457 // type is given Exact Match rank, and a conversion of an 458 // expression of class type to a base class of that type is 459 // given Conversion rank, in spite of the fact that a copy/move 460 // constructor (i.e., a user-defined conversion function) is 461 // called for those cases. 462 QualType FromType = From->getType(); 463 if (!ToType->getAs<RecordType>() || !FromType->getAs<RecordType>() || 464 !(Context.hasSameUnqualifiedType(FromType, ToType) || 465 IsDerivedFrom(FromType, ToType))) { 466 // We're not in the case above, so there is no conversion that 467 // we can perform. 468 ICS.setBad(BadConversionSequence::no_conversion, From, ToType); 469 return ICS; 470 } 471 472 ICS.setStandard(); 473 ICS.Standard.setAsIdentityConversion(); 474 ICS.Standard.setFromType(FromType); 475 ICS.Standard.setAllToTypes(ToType); 476 477 // We don't actually check at this point whether there is a valid 478 // copy/move constructor, since overloading just assumes that it 479 // exists. When we actually perform initialization, we'll find the 480 // appropriate constructor to copy the returned object, if needed. 481 ICS.Standard.CopyConstructor = 0; 482 483 // Determine whether this is considered a derived-to-base conversion. 484 if (!Context.hasSameUnqualifiedType(FromType, ToType)) 485 ICS.Standard.Second = ICK_Derived_To_Base; 486 487 return ICS; 488 } 489 490 // Attempt user-defined conversion. 491 OverloadCandidateSet Conversions(From->getExprLoc()); 492 OverloadingResult UserDefResult 493 = IsUserDefinedConversion(From, ToType, ICS.UserDefined, Conversions, 494 AllowExplicit); 495 496 if (UserDefResult == OR_Success) { 497 ICS.setUserDefined(); 498 // C++ [over.ics.user]p4: 499 // A conversion of an expression of class type to the same class 500 // type is given Exact Match rank, and a conversion of an 501 // expression of class type to a base class of that type is 502 // given Conversion rank, in spite of the fact that a copy 503 // constructor (i.e., a user-defined conversion function) is 504 // called for those cases. 505 if (CXXConstructorDecl *Constructor 506 = dyn_cast<CXXConstructorDecl>(ICS.UserDefined.ConversionFunction)) { 507 QualType FromCanon 508 = Context.getCanonicalType(From->getType().getUnqualifiedType()); 509 QualType ToCanon = Context.getCanonicalType(ToType).getUnqualifiedType(); 510 if (Constructor->isCopyConstructor() && 511 (FromCanon == ToCanon || IsDerivedFrom(FromCanon, ToCanon))) { 512 // Turn this into a "standard" conversion sequence, so that it 513 // gets ranked with standard conversion sequences. 514 ICS.setStandard(); 515 ICS.Standard.setAsIdentityConversion(); 516 ICS.Standard.setFromType(From->getType()); 517 ICS.Standard.setAllToTypes(ToType); 518 ICS.Standard.CopyConstructor = Constructor; 519 if (ToCanon != FromCanon) 520 ICS.Standard.Second = ICK_Derived_To_Base; 521 } 522 } 523 524 // C++ [over.best.ics]p4: 525 // However, when considering the argument of a user-defined 526 // conversion function that is a candidate by 13.3.1.3 when 527 // invoked for the copying of the temporary in the second step 528 // of a class copy-initialization, or by 13.3.1.4, 13.3.1.5, or 529 // 13.3.1.6 in all cases, only standard conversion sequences and 530 // ellipsis conversion sequences are allowed. 531 if (SuppressUserConversions && ICS.isUserDefined()) { 532 ICS.setBad(BadConversionSequence::suppressed_user, From, ToType); 533 } 534 } else if (UserDefResult == OR_Ambiguous && !SuppressUserConversions) { 535 ICS.setAmbiguous(); 536 ICS.Ambiguous.setFromType(From->getType()); 537 ICS.Ambiguous.setToType(ToType); 538 for (OverloadCandidateSet::iterator Cand = Conversions.begin(); 539 Cand != Conversions.end(); ++Cand) 540 if (Cand->Viable) 541 ICS.Ambiguous.addConversion(Cand->Function); 542 } else { 543 ICS.setBad(BadConversionSequence::no_conversion, From, ToType); 544 } 545 546 return ICS; 547} 548 549/// PerformImplicitConversion - Perform an implicit conversion of the 550/// expression From to the type ToType. Returns true if there was an 551/// error, false otherwise. The expression From is replaced with the 552/// converted expression. Flavor is the kind of conversion we're 553/// performing, used in the error message. If @p AllowExplicit, 554/// explicit user-defined conversions are permitted. 555bool 556Sema::PerformImplicitConversion(Expr *&From, QualType ToType, 557 AssignmentAction Action, bool AllowExplicit) { 558 ImplicitConversionSequence ICS; 559 return PerformImplicitConversion(From, ToType, Action, AllowExplicit, ICS); 560} 561 562bool 563Sema::PerformImplicitConversion(Expr *&From, QualType ToType, 564 AssignmentAction Action, bool AllowExplicit, 565 ImplicitConversionSequence& ICS) { 566 ICS = TryImplicitConversion(From, ToType, 567 /*SuppressUserConversions=*/false, 568 AllowExplicit, 569 /*InOverloadResolution=*/false); 570 return PerformImplicitConversion(From, ToType, ICS, Action); 571} 572 573/// \brief Determine whether the conversion from FromType to ToType is a valid 574/// conversion that strips "noreturn" off the nested function type. 575static bool IsNoReturnConversion(ASTContext &Context, QualType FromType, 576 QualType ToType, QualType &ResultTy) { 577 if (Context.hasSameUnqualifiedType(FromType, ToType)) 578 return false; 579 580 // Strip the noreturn off the type we're converting from; noreturn can 581 // safely be removed. 582 FromType = Context.getNoReturnType(FromType, false); 583 if (!Context.hasSameUnqualifiedType(FromType, ToType)) 584 return false; 585 586 ResultTy = FromType; 587 return true; 588} 589 590/// IsStandardConversion - Determines whether there is a standard 591/// conversion sequence (C++ [conv], C++ [over.ics.scs]) from the 592/// expression From to the type ToType. Standard conversion sequences 593/// only consider non-class types; for conversions that involve class 594/// types, use TryImplicitConversion. If a conversion exists, SCS will 595/// contain the standard conversion sequence required to perform this 596/// conversion and this routine will return true. Otherwise, this 597/// routine will return false and the value of SCS is unspecified. 598bool 599Sema::IsStandardConversion(Expr* From, QualType ToType, 600 bool InOverloadResolution, 601 StandardConversionSequence &SCS) { 602 QualType FromType = From->getType(); 603 604 // Standard conversions (C++ [conv]) 605 SCS.setAsIdentityConversion(); 606 SCS.DeprecatedStringLiteralToCharPtr = false; 607 SCS.IncompatibleObjC = false; 608 SCS.setFromType(FromType); 609 SCS.CopyConstructor = 0; 610 611 // There are no standard conversions for class types in C++, so 612 // abort early. When overloading in C, however, we do permit 613 if (FromType->isRecordType() || ToType->isRecordType()) { 614 if (getLangOptions().CPlusPlus) 615 return false; 616 617 // When we're overloading in C, we allow, as standard conversions, 618 } 619 620 // The first conversion can be an lvalue-to-rvalue conversion, 621 // array-to-pointer conversion, or function-to-pointer conversion 622 // (C++ 4p1). 623 624 if (FromType == Context.OverloadTy) { 625 DeclAccessPair AccessPair; 626 if (FunctionDecl *Fn 627 = ResolveAddressOfOverloadedFunction(From, ToType, false, 628 AccessPair)) { 629 // We were able to resolve the address of the overloaded function, 630 // so we can convert to the type of that function. 631 FromType = Fn->getType(); 632 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 633 if (!Method->isStatic()) { 634 Type *ClassType 635 = Context.getTypeDeclType(Method->getParent()).getTypePtr(); 636 FromType = Context.getMemberPointerType(FromType, ClassType); 637 } 638 } 639 640 // If the "from" expression takes the address of the overloaded 641 // function, update the type of the resulting expression accordingly. 642 if (FromType->getAs<FunctionType>()) 643 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(From->IgnoreParens())) 644 if (UnOp->getOpcode() == UnaryOperator::AddrOf) 645 FromType = Context.getPointerType(FromType); 646 647 // Check that we've computed the proper type after overload resolution. 648 assert(Context.hasSameType(FromType, 649 FixOverloadedFunctionReference(From, AccessPair, Fn)->getType())); 650 } else { 651 return false; 652 } 653 } 654 // Lvalue-to-rvalue conversion (C++ 4.1): 655 // An lvalue (3.10) of a non-function, non-array type T can be 656 // converted to an rvalue. 657 Expr::isLvalueResult argIsLvalue = From->isLvalue(Context); 658 if (argIsLvalue == Expr::LV_Valid && 659 !FromType->isFunctionType() && !FromType->isArrayType() && 660 Context.getCanonicalType(FromType) != Context.OverloadTy) { 661 SCS.First = ICK_Lvalue_To_Rvalue; 662 663 // If T is a non-class type, the type of the rvalue is the 664 // cv-unqualified version of T. Otherwise, the type of the rvalue 665 // is T (C++ 4.1p1). C++ can't get here with class types; in C, we 666 // just strip the qualifiers because they don't matter. 667 FromType = FromType.getUnqualifiedType(); 668 } else if (FromType->isArrayType()) { 669 // Array-to-pointer conversion (C++ 4.2) 670 SCS.First = ICK_Array_To_Pointer; 671 672 // An lvalue or rvalue of type "array of N T" or "array of unknown 673 // bound of T" can be converted to an rvalue of type "pointer to 674 // T" (C++ 4.2p1). 675 FromType = Context.getArrayDecayedType(FromType); 676 677 if (IsStringLiteralToNonConstPointerConversion(From, ToType)) { 678 // This conversion is deprecated. (C++ D.4). 679 SCS.DeprecatedStringLiteralToCharPtr = true; 680 681 // For the purpose of ranking in overload resolution 682 // (13.3.3.1.1), this conversion is considered an 683 // array-to-pointer conversion followed by a qualification 684 // conversion (4.4). (C++ 4.2p2) 685 SCS.Second = ICK_Identity; 686 SCS.Third = ICK_Qualification; 687 SCS.setAllToTypes(FromType); 688 return true; 689 } 690 } else if (FromType->isFunctionType() && argIsLvalue == Expr::LV_Valid) { 691 // Function-to-pointer conversion (C++ 4.3). 692 SCS.First = ICK_Function_To_Pointer; 693 694 // An lvalue of function type T can be converted to an rvalue of 695 // type "pointer to T." The result is a pointer to the 696 // function. (C++ 4.3p1). 697 FromType = Context.getPointerType(FromType); 698 } else { 699 // We don't require any conversions for the first step. 700 SCS.First = ICK_Identity; 701 } 702 SCS.setToType(0, FromType); 703 704 // The second conversion can be an integral promotion, floating 705 // point promotion, integral conversion, floating point conversion, 706 // floating-integral conversion, pointer conversion, 707 // pointer-to-member conversion, or boolean conversion (C++ 4p1). 708 // For overloading in C, this can also be a "compatible-type" 709 // conversion. 710 bool IncompatibleObjC = false; 711 if (Context.hasSameUnqualifiedType(FromType, ToType)) { 712 // The unqualified versions of the types are the same: there's no 713 // conversion to do. 714 SCS.Second = ICK_Identity; 715 } else if (IsIntegralPromotion(From, FromType, ToType)) { 716 // Integral promotion (C++ 4.5). 717 SCS.Second = ICK_Integral_Promotion; 718 FromType = ToType.getUnqualifiedType(); 719 } else if (IsFloatingPointPromotion(FromType, ToType)) { 720 // Floating point promotion (C++ 4.6). 721 SCS.Second = ICK_Floating_Promotion; 722 FromType = ToType.getUnqualifiedType(); 723 } else if (IsComplexPromotion(FromType, ToType)) { 724 // Complex promotion (Clang extension) 725 SCS.Second = ICK_Complex_Promotion; 726 FromType = ToType.getUnqualifiedType(); 727 } else if ((FromType->isIntegralType() || FromType->isEnumeralType()) && 728 (ToType->isIntegralType() && !ToType->isEnumeralType())) { 729 // Integral conversions (C++ 4.7). 730 SCS.Second = ICK_Integral_Conversion; 731 FromType = ToType.getUnqualifiedType(); 732 } else if (FromType->isComplexType() && ToType->isComplexType()) { 733 // Complex conversions (C99 6.3.1.6) 734 SCS.Second = ICK_Complex_Conversion; 735 FromType = ToType.getUnqualifiedType(); 736 } else if ((FromType->isComplexType() && ToType->isArithmeticType()) || 737 (ToType->isComplexType() && FromType->isArithmeticType())) { 738 // Complex-real conversions (C99 6.3.1.7) 739 SCS.Second = ICK_Complex_Real; 740 FromType = ToType.getUnqualifiedType(); 741 } else if (FromType->isFloatingType() && ToType->isFloatingType()) { 742 // Floating point conversions (C++ 4.8). 743 SCS.Second = ICK_Floating_Conversion; 744 FromType = ToType.getUnqualifiedType(); 745 } else if ((FromType->isFloatingType() && 746 ToType->isIntegralType() && (!ToType->isBooleanType() && 747 !ToType->isEnumeralType())) || 748 ((FromType->isIntegralType() || FromType->isEnumeralType()) && 749 ToType->isFloatingType())) { 750 // Floating-integral conversions (C++ 4.9). 751 SCS.Second = ICK_Floating_Integral; 752 FromType = ToType.getUnqualifiedType(); 753 } else if (IsPointerConversion(From, FromType, ToType, InOverloadResolution, 754 FromType, IncompatibleObjC)) { 755 // Pointer conversions (C++ 4.10). 756 SCS.Second = ICK_Pointer_Conversion; 757 SCS.IncompatibleObjC = IncompatibleObjC; 758 } else if (IsMemberPointerConversion(From, FromType, ToType, 759 InOverloadResolution, FromType)) { 760 // Pointer to member conversions (4.11). 761 SCS.Second = ICK_Pointer_Member; 762 } else if (ToType->isBooleanType() && 763 (FromType->isArithmeticType() || 764 FromType->isEnumeralType() || 765 FromType->isAnyPointerType() || 766 FromType->isBlockPointerType() || 767 FromType->isMemberPointerType() || 768 FromType->isNullPtrType())) { 769 // Boolean conversions (C++ 4.12). 770 SCS.Second = ICK_Boolean_Conversion; 771 FromType = Context.BoolTy; 772 } else if (!getLangOptions().CPlusPlus && 773 Context.typesAreCompatible(ToType, FromType)) { 774 // Compatible conversions (Clang extension for C function overloading) 775 SCS.Second = ICK_Compatible_Conversion; 776 } else if (IsNoReturnConversion(Context, FromType, ToType, FromType)) { 777 // Treat a conversion that strips "noreturn" as an identity conversion. 778 SCS.Second = ICK_NoReturn_Adjustment; 779 } else { 780 // No second conversion required. 781 SCS.Second = ICK_Identity; 782 } 783 SCS.setToType(1, FromType); 784 785 QualType CanonFrom; 786 QualType CanonTo; 787 // The third conversion can be a qualification conversion (C++ 4p1). 788 if (IsQualificationConversion(FromType, ToType)) { 789 SCS.Third = ICK_Qualification; 790 FromType = ToType; 791 CanonFrom = Context.getCanonicalType(FromType); 792 CanonTo = Context.getCanonicalType(ToType); 793 } else { 794 // No conversion required 795 SCS.Third = ICK_Identity; 796 797 // C++ [over.best.ics]p6: 798 // [...] Any difference in top-level cv-qualification is 799 // subsumed by the initialization itself and does not constitute 800 // a conversion. [...] 801 CanonFrom = Context.getCanonicalType(FromType); 802 CanonTo = Context.getCanonicalType(ToType); 803 if (CanonFrom.getLocalUnqualifiedType() 804 == CanonTo.getLocalUnqualifiedType() && 805 CanonFrom.getLocalCVRQualifiers() != CanonTo.getLocalCVRQualifiers()) { 806 FromType = ToType; 807 CanonFrom = CanonTo; 808 } 809 } 810 SCS.setToType(2, FromType); 811 812 // If we have not converted the argument type to the parameter type, 813 // this is a bad conversion sequence. 814 if (CanonFrom != CanonTo) 815 return false; 816 817 return true; 818} 819 820/// IsIntegralPromotion - Determines whether the conversion from the 821/// expression From (whose potentially-adjusted type is FromType) to 822/// ToType is an integral promotion (C++ 4.5). If so, returns true and 823/// sets PromotedType to the promoted type. 824bool Sema::IsIntegralPromotion(Expr *From, QualType FromType, QualType ToType) { 825 const BuiltinType *To = ToType->getAs<BuiltinType>(); 826 // All integers are built-in. 827 if (!To) { 828 return false; 829 } 830 831 // An rvalue of type char, signed char, unsigned char, short int, or 832 // unsigned short int can be converted to an rvalue of type int if 833 // int can represent all the values of the source type; otherwise, 834 // the source rvalue can be converted to an rvalue of type unsigned 835 // int (C++ 4.5p1). 836 if (FromType->isPromotableIntegerType() && !FromType->isBooleanType() && 837 !FromType->isEnumeralType()) { 838 if (// We can promote any signed, promotable integer type to an int 839 (FromType->isSignedIntegerType() || 840 // We can promote any unsigned integer type whose size is 841 // less than int to an int. 842 (!FromType->isSignedIntegerType() && 843 Context.getTypeSize(FromType) < Context.getTypeSize(ToType)))) { 844 return To->getKind() == BuiltinType::Int; 845 } 846 847 return To->getKind() == BuiltinType::UInt; 848 } 849 850 // An rvalue of type wchar_t (3.9.1) or an enumeration type (7.2) 851 // can be converted to an rvalue of the first of the following types 852 // that can represent all the values of its underlying type: int, 853 // unsigned int, long, or unsigned long (C++ 4.5p2). 854 855 // We pre-calculate the promotion type for enum types. 856 if (const EnumType *FromEnumType = FromType->getAs<EnumType>()) 857 if (ToType->isIntegerType()) 858 return Context.hasSameUnqualifiedType(ToType, 859 FromEnumType->getDecl()->getPromotionType()); 860 861 if (FromType->isWideCharType() && ToType->isIntegerType()) { 862 // Determine whether the type we're converting from is signed or 863 // unsigned. 864 bool FromIsSigned; 865 uint64_t FromSize = Context.getTypeSize(FromType); 866 867 // FIXME: Is wchar_t signed or unsigned? We assume it's signed for now. 868 FromIsSigned = true; 869 870 // The types we'll try to promote to, in the appropriate 871 // order. Try each of these types. 872 QualType PromoteTypes[6] = { 873 Context.IntTy, Context.UnsignedIntTy, 874 Context.LongTy, Context.UnsignedLongTy , 875 Context.LongLongTy, Context.UnsignedLongLongTy 876 }; 877 for (int Idx = 0; Idx < 6; ++Idx) { 878 uint64_t ToSize = Context.getTypeSize(PromoteTypes[Idx]); 879 if (FromSize < ToSize || 880 (FromSize == ToSize && 881 FromIsSigned == PromoteTypes[Idx]->isSignedIntegerType())) { 882 // We found the type that we can promote to. If this is the 883 // type we wanted, we have a promotion. Otherwise, no 884 // promotion. 885 return Context.hasSameUnqualifiedType(ToType, PromoteTypes[Idx]); 886 } 887 } 888 } 889 890 // An rvalue for an integral bit-field (9.6) can be converted to an 891 // rvalue of type int if int can represent all the values of the 892 // bit-field; otherwise, it can be converted to unsigned int if 893 // unsigned int can represent all the values of the bit-field. If 894 // the bit-field is larger yet, no integral promotion applies to 895 // it. If the bit-field has an enumerated type, it is treated as any 896 // other value of that type for promotion purposes (C++ 4.5p3). 897 // FIXME: We should delay checking of bit-fields until we actually perform the 898 // conversion. 899 using llvm::APSInt; 900 if (From) 901 if (FieldDecl *MemberDecl = From->getBitField()) { 902 APSInt BitWidth; 903 if (FromType->isIntegralType() && !FromType->isEnumeralType() && 904 MemberDecl->getBitWidth()->isIntegerConstantExpr(BitWidth, Context)) { 905 APSInt ToSize(BitWidth.getBitWidth(), BitWidth.isUnsigned()); 906 ToSize = Context.getTypeSize(ToType); 907 908 // Are we promoting to an int from a bitfield that fits in an int? 909 if (BitWidth < ToSize || 910 (FromType->isSignedIntegerType() && BitWidth <= ToSize)) { 911 return To->getKind() == BuiltinType::Int; 912 } 913 914 // Are we promoting to an unsigned int from an unsigned bitfield 915 // that fits into an unsigned int? 916 if (FromType->isUnsignedIntegerType() && BitWidth <= ToSize) { 917 return To->getKind() == BuiltinType::UInt; 918 } 919 920 return false; 921 } 922 } 923 924 // An rvalue of type bool can be converted to an rvalue of type int, 925 // with false becoming zero and true becoming one (C++ 4.5p4). 926 if (FromType->isBooleanType() && To->getKind() == BuiltinType::Int) { 927 return true; 928 } 929 930 return false; 931} 932 933/// IsFloatingPointPromotion - Determines whether the conversion from 934/// FromType to ToType is a floating point promotion (C++ 4.6). If so, 935/// returns true and sets PromotedType to the promoted type. 936bool Sema::IsFloatingPointPromotion(QualType FromType, QualType ToType) { 937 /// An rvalue of type float can be converted to an rvalue of type 938 /// double. (C++ 4.6p1). 939 if (const BuiltinType *FromBuiltin = FromType->getAs<BuiltinType>()) 940 if (const BuiltinType *ToBuiltin = ToType->getAs<BuiltinType>()) { 941 if (FromBuiltin->getKind() == BuiltinType::Float && 942 ToBuiltin->getKind() == BuiltinType::Double) 943 return true; 944 945 // C99 6.3.1.5p1: 946 // When a float is promoted to double or long double, or a 947 // double is promoted to long double [...]. 948 if (!getLangOptions().CPlusPlus && 949 (FromBuiltin->getKind() == BuiltinType::Float || 950 FromBuiltin->getKind() == BuiltinType::Double) && 951 (ToBuiltin->getKind() == BuiltinType::LongDouble)) 952 return true; 953 } 954 955 return false; 956} 957 958/// \brief Determine if a conversion is a complex promotion. 959/// 960/// A complex promotion is defined as a complex -> complex conversion 961/// where the conversion between the underlying real types is a 962/// floating-point or integral promotion. 963bool Sema::IsComplexPromotion(QualType FromType, QualType ToType) { 964 const ComplexType *FromComplex = FromType->getAs<ComplexType>(); 965 if (!FromComplex) 966 return false; 967 968 const ComplexType *ToComplex = ToType->getAs<ComplexType>(); 969 if (!ToComplex) 970 return false; 971 972 return IsFloatingPointPromotion(FromComplex->getElementType(), 973 ToComplex->getElementType()) || 974 IsIntegralPromotion(0, FromComplex->getElementType(), 975 ToComplex->getElementType()); 976} 977 978/// BuildSimilarlyQualifiedPointerType - In a pointer conversion from 979/// the pointer type FromPtr to a pointer to type ToPointee, with the 980/// same type qualifiers as FromPtr has on its pointee type. ToType, 981/// if non-empty, will be a pointer to ToType that may or may not have 982/// the right set of qualifiers on its pointee. 983static QualType 984BuildSimilarlyQualifiedPointerType(const PointerType *FromPtr, 985 QualType ToPointee, QualType ToType, 986 ASTContext &Context) { 987 QualType CanonFromPointee = Context.getCanonicalType(FromPtr->getPointeeType()); 988 QualType CanonToPointee = Context.getCanonicalType(ToPointee); 989 Qualifiers Quals = CanonFromPointee.getQualifiers(); 990 991 // Exact qualifier match -> return the pointer type we're converting to. 992 if (CanonToPointee.getLocalQualifiers() == Quals) { 993 // ToType is exactly what we need. Return it. 994 if (!ToType.isNull()) 995 return ToType; 996 997 // Build a pointer to ToPointee. It has the right qualifiers 998 // already. 999 return Context.getPointerType(ToPointee); 1000 } 1001 1002 // Just build a canonical type that has the right qualifiers. 1003 return Context.getPointerType( 1004 Context.getQualifiedType(CanonToPointee.getLocalUnqualifiedType(), 1005 Quals)); 1006} 1007 1008/// BuildSimilarlyQualifiedObjCObjectPointerType - In a pointer conversion from 1009/// the FromType, which is an objective-c pointer, to ToType, which may or may 1010/// not have the right set of qualifiers. 1011static QualType 1012BuildSimilarlyQualifiedObjCObjectPointerType(QualType FromType, 1013 QualType ToType, 1014 ASTContext &Context) { 1015 QualType CanonFromType = Context.getCanonicalType(FromType); 1016 QualType CanonToType = Context.getCanonicalType(ToType); 1017 Qualifiers Quals = CanonFromType.getQualifiers(); 1018 1019 // Exact qualifier match -> return the pointer type we're converting to. 1020 if (CanonToType.getLocalQualifiers() == Quals) 1021 return ToType; 1022 1023 // Just build a canonical type that has the right qualifiers. 1024 return Context.getQualifiedType(CanonToType.getLocalUnqualifiedType(), Quals); 1025} 1026 1027static bool isNullPointerConstantForConversion(Expr *Expr, 1028 bool InOverloadResolution, 1029 ASTContext &Context) { 1030 // Handle value-dependent integral null pointer constants correctly. 1031 // http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#903 1032 if (Expr->isValueDependent() && !Expr->isTypeDependent() && 1033 Expr->getType()->isIntegralType()) 1034 return !InOverloadResolution; 1035 1036 return Expr->isNullPointerConstant(Context, 1037 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull 1038 : Expr::NPC_ValueDependentIsNull); 1039} 1040 1041/// IsPointerConversion - Determines whether the conversion of the 1042/// expression From, which has the (possibly adjusted) type FromType, 1043/// can be converted to the type ToType via a pointer conversion (C++ 1044/// 4.10). If so, returns true and places the converted type (that 1045/// might differ from ToType in its cv-qualifiers at some level) into 1046/// ConvertedType. 1047/// 1048/// This routine also supports conversions to and from block pointers 1049/// and conversions with Objective-C's 'id', 'id<protocols...>', and 1050/// pointers to interfaces. FIXME: Once we've determined the 1051/// appropriate overloading rules for Objective-C, we may want to 1052/// split the Objective-C checks into a different routine; however, 1053/// GCC seems to consider all of these conversions to be pointer 1054/// conversions, so for now they live here. IncompatibleObjC will be 1055/// set if the conversion is an allowed Objective-C conversion that 1056/// should result in a warning. 1057bool Sema::IsPointerConversion(Expr *From, QualType FromType, QualType ToType, 1058 bool InOverloadResolution, 1059 QualType& ConvertedType, 1060 bool &IncompatibleObjC) { 1061 IncompatibleObjC = false; 1062 if (isObjCPointerConversion(FromType, ToType, ConvertedType, IncompatibleObjC)) 1063 return true; 1064 1065 // Conversion from a null pointer constant to any Objective-C pointer type. 1066 if (ToType->isObjCObjectPointerType() && 1067 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1068 ConvertedType = ToType; 1069 return true; 1070 } 1071 1072 // Blocks: Block pointers can be converted to void*. 1073 if (FromType->isBlockPointerType() && ToType->isPointerType() && 1074 ToType->getAs<PointerType>()->getPointeeType()->isVoidType()) { 1075 ConvertedType = ToType; 1076 return true; 1077 } 1078 // Blocks: A null pointer constant can be converted to a block 1079 // pointer type. 1080 if (ToType->isBlockPointerType() && 1081 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1082 ConvertedType = ToType; 1083 return true; 1084 } 1085 1086 // If the left-hand-side is nullptr_t, the right side can be a null 1087 // pointer constant. 1088 if (ToType->isNullPtrType() && 1089 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1090 ConvertedType = ToType; 1091 return true; 1092 } 1093 1094 const PointerType* ToTypePtr = ToType->getAs<PointerType>(); 1095 if (!ToTypePtr) 1096 return false; 1097 1098 // A null pointer constant can be converted to a pointer type (C++ 4.10p1). 1099 if (isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1100 ConvertedType = ToType; 1101 return true; 1102 } 1103 1104 // Beyond this point, both types need to be pointers 1105 // , including objective-c pointers. 1106 QualType ToPointeeType = ToTypePtr->getPointeeType(); 1107 if (FromType->isObjCObjectPointerType() && ToPointeeType->isVoidType()) { 1108 ConvertedType = BuildSimilarlyQualifiedObjCObjectPointerType(FromType, 1109 ToType, Context); 1110 return true; 1111 1112 } 1113 const PointerType *FromTypePtr = FromType->getAs<PointerType>(); 1114 if (!FromTypePtr) 1115 return false; 1116 1117 QualType FromPointeeType = FromTypePtr->getPointeeType(); 1118 1119 // An rvalue of type "pointer to cv T," where T is an object type, 1120 // can be converted to an rvalue of type "pointer to cv void" (C++ 1121 // 4.10p2). 1122 if (FromPointeeType->isObjectType() && ToPointeeType->isVoidType()) { 1123 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1124 ToPointeeType, 1125 ToType, Context); 1126 return true; 1127 } 1128 1129 // When we're overloading in C, we allow a special kind of pointer 1130 // conversion for compatible-but-not-identical pointee types. 1131 if (!getLangOptions().CPlusPlus && 1132 Context.typesAreCompatible(FromPointeeType, ToPointeeType)) { 1133 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1134 ToPointeeType, 1135 ToType, Context); 1136 return true; 1137 } 1138 1139 // C++ [conv.ptr]p3: 1140 // 1141 // An rvalue of type "pointer to cv D," where D is a class type, 1142 // can be converted to an rvalue of type "pointer to cv B," where 1143 // B is a base class (clause 10) of D. If B is an inaccessible 1144 // (clause 11) or ambiguous (10.2) base class of D, a program that 1145 // necessitates this conversion is ill-formed. The result of the 1146 // conversion is a pointer to the base class sub-object of the 1147 // derived class object. The null pointer value is converted to 1148 // the null pointer value of the destination type. 1149 // 1150 // Note that we do not check for ambiguity or inaccessibility 1151 // here. That is handled by CheckPointerConversion. 1152 if (getLangOptions().CPlusPlus && 1153 FromPointeeType->isRecordType() && ToPointeeType->isRecordType() && 1154 !Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType) && 1155 !RequireCompleteType(From->getLocStart(), FromPointeeType, PDiag()) && 1156 IsDerivedFrom(FromPointeeType, ToPointeeType)) { 1157 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1158 ToPointeeType, 1159 ToType, Context); 1160 return true; 1161 } 1162 1163 return false; 1164} 1165 1166/// isObjCPointerConversion - Determines whether this is an 1167/// Objective-C pointer conversion. Subroutine of IsPointerConversion, 1168/// with the same arguments and return values. 1169bool Sema::isObjCPointerConversion(QualType FromType, QualType ToType, 1170 QualType& ConvertedType, 1171 bool &IncompatibleObjC) { 1172 if (!getLangOptions().ObjC1) 1173 return false; 1174 1175 // First, we handle all conversions on ObjC object pointer types. 1176 const ObjCObjectPointerType* ToObjCPtr = ToType->getAs<ObjCObjectPointerType>(); 1177 const ObjCObjectPointerType *FromObjCPtr = 1178 FromType->getAs<ObjCObjectPointerType>(); 1179 1180 if (ToObjCPtr && FromObjCPtr) { 1181 // Objective C++: We're able to convert between "id" or "Class" and a 1182 // pointer to any interface (in both directions). 1183 if (ToObjCPtr->isObjCBuiltinType() && FromObjCPtr->isObjCBuiltinType()) { 1184 ConvertedType = ToType; 1185 return true; 1186 } 1187 // Conversions with Objective-C's id<...>. 1188 if ((FromObjCPtr->isObjCQualifiedIdType() || 1189 ToObjCPtr->isObjCQualifiedIdType()) && 1190 Context.ObjCQualifiedIdTypesAreCompatible(ToType, FromType, 1191 /*compare=*/false)) { 1192 ConvertedType = ToType; 1193 return true; 1194 } 1195 // Objective C++: We're able to convert from a pointer to an 1196 // interface to a pointer to a different interface. 1197 if (Context.canAssignObjCInterfaces(ToObjCPtr, FromObjCPtr)) { 1198 const ObjCInterfaceType* LHS = ToObjCPtr->getInterfaceType(); 1199 const ObjCInterfaceType* RHS = FromObjCPtr->getInterfaceType(); 1200 if (getLangOptions().CPlusPlus && LHS && RHS && 1201 !ToObjCPtr->getPointeeType().isAtLeastAsQualifiedAs( 1202 FromObjCPtr->getPointeeType())) 1203 return false; 1204 ConvertedType = ToType; 1205 return true; 1206 } 1207 1208 if (Context.canAssignObjCInterfaces(FromObjCPtr, ToObjCPtr)) { 1209 // Okay: this is some kind of implicit downcast of Objective-C 1210 // interfaces, which is permitted. However, we're going to 1211 // complain about it. 1212 IncompatibleObjC = true; 1213 ConvertedType = FromType; 1214 return true; 1215 } 1216 } 1217 // Beyond this point, both types need to be C pointers or block pointers. 1218 QualType ToPointeeType; 1219 if (const PointerType *ToCPtr = ToType->getAs<PointerType>()) 1220 ToPointeeType = ToCPtr->getPointeeType(); 1221 else if (const BlockPointerType *ToBlockPtr = 1222 ToType->getAs<BlockPointerType>()) { 1223 // Objective C++: We're able to convert from a pointer to any object 1224 // to a block pointer type. 1225 if (FromObjCPtr && FromObjCPtr->isObjCBuiltinType()) { 1226 ConvertedType = ToType; 1227 return true; 1228 } 1229 ToPointeeType = ToBlockPtr->getPointeeType(); 1230 } 1231 else if (FromType->getAs<BlockPointerType>() && 1232 ToObjCPtr && ToObjCPtr->isObjCBuiltinType()) { 1233 // Objective C++: We're able to convert from a block pointer type to a 1234 // pointer to any object. 1235 ConvertedType = ToType; 1236 return true; 1237 } 1238 else 1239 return false; 1240 1241 QualType FromPointeeType; 1242 if (const PointerType *FromCPtr = FromType->getAs<PointerType>()) 1243 FromPointeeType = FromCPtr->getPointeeType(); 1244 else if (const BlockPointerType *FromBlockPtr = FromType->getAs<BlockPointerType>()) 1245 FromPointeeType = FromBlockPtr->getPointeeType(); 1246 else 1247 return false; 1248 1249 // If we have pointers to pointers, recursively check whether this 1250 // is an Objective-C conversion. 1251 if (FromPointeeType->isPointerType() && ToPointeeType->isPointerType() && 1252 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, 1253 IncompatibleObjC)) { 1254 // We always complain about this conversion. 1255 IncompatibleObjC = true; 1256 ConvertedType = ToType; 1257 return true; 1258 } 1259 // Allow conversion of pointee being objective-c pointer to another one; 1260 // as in I* to id. 1261 if (FromPointeeType->getAs<ObjCObjectPointerType>() && 1262 ToPointeeType->getAs<ObjCObjectPointerType>() && 1263 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, 1264 IncompatibleObjC)) { 1265 ConvertedType = ToType; 1266 return true; 1267 } 1268 1269 // If we have pointers to functions or blocks, check whether the only 1270 // differences in the argument and result types are in Objective-C 1271 // pointer conversions. If so, we permit the conversion (but 1272 // complain about it). 1273 const FunctionProtoType *FromFunctionType 1274 = FromPointeeType->getAs<FunctionProtoType>(); 1275 const FunctionProtoType *ToFunctionType 1276 = ToPointeeType->getAs<FunctionProtoType>(); 1277 if (FromFunctionType && ToFunctionType) { 1278 // If the function types are exactly the same, this isn't an 1279 // Objective-C pointer conversion. 1280 if (Context.getCanonicalType(FromPointeeType) 1281 == Context.getCanonicalType(ToPointeeType)) 1282 return false; 1283 1284 // Perform the quick checks that will tell us whether these 1285 // function types are obviously different. 1286 if (FromFunctionType->getNumArgs() != ToFunctionType->getNumArgs() || 1287 FromFunctionType->isVariadic() != ToFunctionType->isVariadic() || 1288 FromFunctionType->getTypeQuals() != ToFunctionType->getTypeQuals()) 1289 return false; 1290 1291 bool HasObjCConversion = false; 1292 if (Context.getCanonicalType(FromFunctionType->getResultType()) 1293 == Context.getCanonicalType(ToFunctionType->getResultType())) { 1294 // Okay, the types match exactly. Nothing to do. 1295 } else if (isObjCPointerConversion(FromFunctionType->getResultType(), 1296 ToFunctionType->getResultType(), 1297 ConvertedType, IncompatibleObjC)) { 1298 // Okay, we have an Objective-C pointer conversion. 1299 HasObjCConversion = true; 1300 } else { 1301 // Function types are too different. Abort. 1302 return false; 1303 } 1304 1305 // Check argument types. 1306 for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumArgs(); 1307 ArgIdx != NumArgs; ++ArgIdx) { 1308 QualType FromArgType = FromFunctionType->getArgType(ArgIdx); 1309 QualType ToArgType = ToFunctionType->getArgType(ArgIdx); 1310 if (Context.getCanonicalType(FromArgType) 1311 == Context.getCanonicalType(ToArgType)) { 1312 // Okay, the types match exactly. Nothing to do. 1313 } else if (isObjCPointerConversion(FromArgType, ToArgType, 1314 ConvertedType, IncompatibleObjC)) { 1315 // Okay, we have an Objective-C pointer conversion. 1316 HasObjCConversion = true; 1317 } else { 1318 // Argument types are too different. Abort. 1319 return false; 1320 } 1321 } 1322 1323 if (HasObjCConversion) { 1324 // We had an Objective-C conversion. Allow this pointer 1325 // conversion, but complain about it. 1326 ConvertedType = ToType; 1327 IncompatibleObjC = true; 1328 return true; 1329 } 1330 } 1331 1332 return false; 1333} 1334 1335/// FunctionArgTypesAreEqual - This routine checks two function proto types 1336/// for equlity of their argument types. Caller has already checked that 1337/// they have same number of arguments. This routine assumes that Objective-C 1338/// pointer types which only differ in their protocol qualifiers are equal. 1339bool Sema::FunctionArgTypesAreEqual(FunctionProtoType* OldType, 1340 FunctionProtoType* NewType){ 1341 if (!getLangOptions().ObjC1) 1342 return std::equal(OldType->arg_type_begin(), OldType->arg_type_end(), 1343 NewType->arg_type_begin()); 1344 1345 for (FunctionProtoType::arg_type_iterator O = OldType->arg_type_begin(), 1346 N = NewType->arg_type_begin(), 1347 E = OldType->arg_type_end(); O && (O != E); ++O, ++N) { 1348 QualType ToType = (*O); 1349 QualType FromType = (*N); 1350 if (ToType != FromType) { 1351 if (const PointerType *PTTo = ToType->getAs<PointerType>()) { 1352 if (const PointerType *PTFr = FromType->getAs<PointerType>()) 1353 if ((PTTo->getPointeeType()->isObjCQualifiedIdType() && 1354 PTFr->getPointeeType()->isObjCQualifiedIdType()) || 1355 (PTTo->getPointeeType()->isObjCQualifiedClassType() && 1356 PTFr->getPointeeType()->isObjCQualifiedClassType())) 1357 continue; 1358 } 1359 else if (ToType->isObjCObjectPointerType() && 1360 FromType->isObjCObjectPointerType()) { 1361 QualType ToInterfaceTy = ToType->getPointeeType(); 1362 QualType FromInterfaceTy = FromType->getPointeeType(); 1363 if (const ObjCInterfaceType *OITTo = 1364 ToInterfaceTy->getAs<ObjCInterfaceType>()) 1365 if (const ObjCInterfaceType *OITFr = 1366 FromInterfaceTy->getAs<ObjCInterfaceType>()) 1367 if (OITTo->getDecl() == OITFr->getDecl()) 1368 continue; 1369 } 1370 return false; 1371 } 1372 } 1373 return true; 1374} 1375 1376/// CheckPointerConversion - Check the pointer conversion from the 1377/// expression From to the type ToType. This routine checks for 1378/// ambiguous or inaccessible derived-to-base pointer 1379/// conversions for which IsPointerConversion has already returned 1380/// true. It returns true and produces a diagnostic if there was an 1381/// error, or returns false otherwise. 1382bool Sema::CheckPointerConversion(Expr *From, QualType ToType, 1383 CastExpr::CastKind &Kind, 1384 CXXBaseSpecifierArray& BasePath, 1385 bool IgnoreBaseAccess) { 1386 QualType FromType = From->getType(); 1387 1388 if (const PointerType *FromPtrType = FromType->getAs<PointerType>()) 1389 if (const PointerType *ToPtrType = ToType->getAs<PointerType>()) { 1390 QualType FromPointeeType = FromPtrType->getPointeeType(), 1391 ToPointeeType = ToPtrType->getPointeeType(); 1392 1393 if (FromPointeeType->isRecordType() && ToPointeeType->isRecordType() && 1394 !Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType)) { 1395 // We must have a derived-to-base conversion. Check an 1396 // ambiguous or inaccessible conversion. 1397 if (CheckDerivedToBaseConversion(FromPointeeType, ToPointeeType, 1398 From->getExprLoc(), 1399 From->getSourceRange(), &BasePath, 1400 IgnoreBaseAccess)) 1401 return true; 1402 1403 // The conversion was successful. 1404 Kind = CastExpr::CK_DerivedToBase; 1405 } 1406 } 1407 if (const ObjCObjectPointerType *FromPtrType = 1408 FromType->getAs<ObjCObjectPointerType>()) 1409 if (const ObjCObjectPointerType *ToPtrType = 1410 ToType->getAs<ObjCObjectPointerType>()) { 1411 // Objective-C++ conversions are always okay. 1412 // FIXME: We should have a different class of conversions for the 1413 // Objective-C++ implicit conversions. 1414 if (FromPtrType->isObjCBuiltinType() || ToPtrType->isObjCBuiltinType()) 1415 return false; 1416 1417 } 1418 return false; 1419} 1420 1421/// IsMemberPointerConversion - Determines whether the conversion of the 1422/// expression From, which has the (possibly adjusted) type FromType, can be 1423/// converted to the type ToType via a member pointer conversion (C++ 4.11). 1424/// If so, returns true and places the converted type (that might differ from 1425/// ToType in its cv-qualifiers at some level) into ConvertedType. 1426bool Sema::IsMemberPointerConversion(Expr *From, QualType FromType, 1427 QualType ToType, 1428 bool InOverloadResolution, 1429 QualType &ConvertedType) { 1430 const MemberPointerType *ToTypePtr = ToType->getAs<MemberPointerType>(); 1431 if (!ToTypePtr) 1432 return false; 1433 1434 // A null pointer constant can be converted to a member pointer (C++ 4.11p1) 1435 if (From->isNullPointerConstant(Context, 1436 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull 1437 : Expr::NPC_ValueDependentIsNull)) { 1438 ConvertedType = ToType; 1439 return true; 1440 } 1441 1442 // Otherwise, both types have to be member pointers. 1443 const MemberPointerType *FromTypePtr = FromType->getAs<MemberPointerType>(); 1444 if (!FromTypePtr) 1445 return false; 1446 1447 // A pointer to member of B can be converted to a pointer to member of D, 1448 // where D is derived from B (C++ 4.11p2). 1449 QualType FromClass(FromTypePtr->getClass(), 0); 1450 QualType ToClass(ToTypePtr->getClass(), 0); 1451 // FIXME: What happens when these are dependent? Is this function even called? 1452 1453 if (IsDerivedFrom(ToClass, FromClass)) { 1454 ConvertedType = Context.getMemberPointerType(FromTypePtr->getPointeeType(), 1455 ToClass.getTypePtr()); 1456 return true; 1457 } 1458 1459 return false; 1460} 1461 1462/// CheckMemberPointerConversion - Check the member pointer conversion from the 1463/// expression From to the type ToType. This routine checks for ambiguous or 1464/// virtual or inaccessible base-to-derived member pointer conversions 1465/// for which IsMemberPointerConversion has already returned true. It returns 1466/// true and produces a diagnostic if there was an error, or returns false 1467/// otherwise. 1468bool Sema::CheckMemberPointerConversion(Expr *From, QualType ToType, 1469 CastExpr::CastKind &Kind, 1470 CXXBaseSpecifierArray &BasePath, 1471 bool IgnoreBaseAccess) { 1472 QualType FromType = From->getType(); 1473 const MemberPointerType *FromPtrType = FromType->getAs<MemberPointerType>(); 1474 if (!FromPtrType) { 1475 // This must be a null pointer to member pointer conversion 1476 assert(From->isNullPointerConstant(Context, 1477 Expr::NPC_ValueDependentIsNull) && 1478 "Expr must be null pointer constant!"); 1479 Kind = CastExpr::CK_NullToMemberPointer; 1480 return false; 1481 } 1482 1483 const MemberPointerType *ToPtrType = ToType->getAs<MemberPointerType>(); 1484 assert(ToPtrType && "No member pointer cast has a target type " 1485 "that is not a member pointer."); 1486 1487 QualType FromClass = QualType(FromPtrType->getClass(), 0); 1488 QualType ToClass = QualType(ToPtrType->getClass(), 0); 1489 1490 // FIXME: What about dependent types? 1491 assert(FromClass->isRecordType() && "Pointer into non-class."); 1492 assert(ToClass->isRecordType() && "Pointer into non-class."); 1493 1494 CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true, 1495 /*DetectVirtual=*/true); 1496 bool DerivationOkay = IsDerivedFrom(ToClass, FromClass, Paths); 1497 assert(DerivationOkay && 1498 "Should not have been called if derivation isn't OK."); 1499 (void)DerivationOkay; 1500 1501 if (Paths.isAmbiguous(Context.getCanonicalType(FromClass). 1502 getUnqualifiedType())) { 1503 std::string PathDisplayStr = getAmbiguousPathsDisplayString(Paths); 1504 Diag(From->getExprLoc(), diag::err_ambiguous_memptr_conv) 1505 << 0 << FromClass << ToClass << PathDisplayStr << From->getSourceRange(); 1506 return true; 1507 } 1508 1509 if (const RecordType *VBase = Paths.getDetectedVirtual()) { 1510 Diag(From->getExprLoc(), diag::err_memptr_conv_via_virtual) 1511 << FromClass << ToClass << QualType(VBase, 0) 1512 << From->getSourceRange(); 1513 return true; 1514 } 1515 1516 if (!IgnoreBaseAccess) 1517 CheckBaseClassAccess(From->getExprLoc(), FromClass, ToClass, 1518 Paths.front(), 1519 diag::err_downcast_from_inaccessible_base); 1520 1521 // Must be a base to derived member conversion. 1522 BuildBasePathArray(Paths, BasePath); 1523 Kind = CastExpr::CK_BaseToDerivedMemberPointer; 1524 return false; 1525} 1526 1527/// IsQualificationConversion - Determines whether the conversion from 1528/// an rvalue of type FromType to ToType is a qualification conversion 1529/// (C++ 4.4). 1530bool 1531Sema::IsQualificationConversion(QualType FromType, QualType ToType) { 1532 FromType = Context.getCanonicalType(FromType); 1533 ToType = Context.getCanonicalType(ToType); 1534 1535 // If FromType and ToType are the same type, this is not a 1536 // qualification conversion. 1537 if (FromType.getUnqualifiedType() == ToType.getUnqualifiedType()) 1538 return false; 1539 1540 // (C++ 4.4p4): 1541 // A conversion can add cv-qualifiers at levels other than the first 1542 // in multi-level pointers, subject to the following rules: [...] 1543 bool PreviousToQualsIncludeConst = true; 1544 bool UnwrappedAnyPointer = false; 1545 while (UnwrapSimilarPointerTypes(FromType, ToType)) { 1546 // Within each iteration of the loop, we check the qualifiers to 1547 // determine if this still looks like a qualification 1548 // conversion. Then, if all is well, we unwrap one more level of 1549 // pointers or pointers-to-members and do it all again 1550 // until there are no more pointers or pointers-to-members left to 1551 // unwrap. 1552 UnwrappedAnyPointer = true; 1553 1554 // -- for every j > 0, if const is in cv 1,j then const is in cv 1555 // 2,j, and similarly for volatile. 1556 if (!ToType.isAtLeastAsQualifiedAs(FromType)) 1557 return false; 1558 1559 // -- if the cv 1,j and cv 2,j are different, then const is in 1560 // every cv for 0 < k < j. 1561 if (FromType.getCVRQualifiers() != ToType.getCVRQualifiers() 1562 && !PreviousToQualsIncludeConst) 1563 return false; 1564 1565 // Keep track of whether all prior cv-qualifiers in the "to" type 1566 // include const. 1567 PreviousToQualsIncludeConst 1568 = PreviousToQualsIncludeConst && ToType.isConstQualified(); 1569 } 1570 1571 // We are left with FromType and ToType being the pointee types 1572 // after unwrapping the original FromType and ToType the same number 1573 // of types. If we unwrapped any pointers, and if FromType and 1574 // ToType have the same unqualified type (since we checked 1575 // qualifiers above), then this is a qualification conversion. 1576 return UnwrappedAnyPointer && Context.hasSameUnqualifiedType(FromType,ToType); 1577} 1578 1579/// Determines whether there is a user-defined conversion sequence 1580/// (C++ [over.ics.user]) that converts expression From to the type 1581/// ToType. If such a conversion exists, User will contain the 1582/// user-defined conversion sequence that performs such a conversion 1583/// and this routine will return true. Otherwise, this routine returns 1584/// false and User is unspecified. 1585/// 1586/// \param AllowExplicit true if the conversion should consider C++0x 1587/// "explicit" conversion functions as well as non-explicit conversion 1588/// functions (C++0x [class.conv.fct]p2). 1589OverloadingResult Sema::IsUserDefinedConversion(Expr *From, QualType ToType, 1590 UserDefinedConversionSequence& User, 1591 OverloadCandidateSet& CandidateSet, 1592 bool AllowExplicit) { 1593 // Whether we will only visit constructors. 1594 bool ConstructorsOnly = false; 1595 1596 // If the type we are conversion to is a class type, enumerate its 1597 // constructors. 1598 if (const RecordType *ToRecordType = ToType->getAs<RecordType>()) { 1599 // C++ [over.match.ctor]p1: 1600 // When objects of class type are direct-initialized (8.5), or 1601 // copy-initialized from an expression of the same or a 1602 // derived class type (8.5), overload resolution selects the 1603 // constructor. [...] For copy-initialization, the candidate 1604 // functions are all the converting constructors (12.3.1) of 1605 // that class. The argument list is the expression-list within 1606 // the parentheses of the initializer. 1607 if (Context.hasSameUnqualifiedType(ToType, From->getType()) || 1608 (From->getType()->getAs<RecordType>() && 1609 IsDerivedFrom(From->getType(), ToType))) 1610 ConstructorsOnly = true; 1611 1612 if (RequireCompleteType(From->getLocStart(), ToType, PDiag())) { 1613 // We're not going to find any constructors. 1614 } else if (CXXRecordDecl *ToRecordDecl 1615 = dyn_cast<CXXRecordDecl>(ToRecordType->getDecl())) { 1616 DeclarationName ConstructorName 1617 = Context.DeclarationNames.getCXXConstructorName( 1618 Context.getCanonicalType(ToType).getUnqualifiedType()); 1619 DeclContext::lookup_iterator Con, ConEnd; 1620 for (llvm::tie(Con, ConEnd) 1621 = ToRecordDecl->lookup(ConstructorName); 1622 Con != ConEnd; ++Con) { 1623 NamedDecl *D = *Con; 1624 DeclAccessPair FoundDecl = DeclAccessPair::make(D, D->getAccess()); 1625 1626 // Find the constructor (which may be a template). 1627 CXXConstructorDecl *Constructor = 0; 1628 FunctionTemplateDecl *ConstructorTmpl 1629 = dyn_cast<FunctionTemplateDecl>(D); 1630 if (ConstructorTmpl) 1631 Constructor 1632 = cast<CXXConstructorDecl>(ConstructorTmpl->getTemplatedDecl()); 1633 else 1634 Constructor = cast<CXXConstructorDecl>(D); 1635 1636 if (!Constructor->isInvalidDecl() && 1637 Constructor->isConvertingConstructor(AllowExplicit)) { 1638 if (ConstructorTmpl) 1639 AddTemplateOverloadCandidate(ConstructorTmpl, FoundDecl, 1640 /*ExplicitArgs*/ 0, 1641 &From, 1, CandidateSet, 1642 /*SuppressUserConversions=*/!ConstructorsOnly); 1643 else 1644 // Allow one user-defined conversion when user specifies a 1645 // From->ToType conversion via an static cast (c-style, etc). 1646 AddOverloadCandidate(Constructor, FoundDecl, 1647 &From, 1, CandidateSet, 1648 /*SuppressUserConversions=*/!ConstructorsOnly); 1649 } 1650 } 1651 } 1652 } 1653 1654 // Enumerate conversion functions, if we're allowed to. 1655 if (ConstructorsOnly) { 1656 } else if (RequireCompleteType(From->getLocStart(), From->getType(), 1657 PDiag(0) << From->getSourceRange())) { 1658 // No conversion functions from incomplete types. 1659 } else if (const RecordType *FromRecordType 1660 = From->getType()->getAs<RecordType>()) { 1661 if (CXXRecordDecl *FromRecordDecl 1662 = dyn_cast<CXXRecordDecl>(FromRecordType->getDecl())) { 1663 // Add all of the conversion functions as candidates. 1664 const UnresolvedSetImpl *Conversions 1665 = FromRecordDecl->getVisibleConversionFunctions(); 1666 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 1667 E = Conversions->end(); I != E; ++I) { 1668 DeclAccessPair FoundDecl = I.getPair(); 1669 NamedDecl *D = FoundDecl.getDecl(); 1670 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext()); 1671 if (isa<UsingShadowDecl>(D)) 1672 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 1673 1674 CXXConversionDecl *Conv; 1675 FunctionTemplateDecl *ConvTemplate; 1676 if ((ConvTemplate = dyn_cast<FunctionTemplateDecl>(D))) 1677 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 1678 else 1679 Conv = cast<CXXConversionDecl>(D); 1680 1681 if (AllowExplicit || !Conv->isExplicit()) { 1682 if (ConvTemplate) 1683 AddTemplateConversionCandidate(ConvTemplate, FoundDecl, 1684 ActingContext, From, ToType, 1685 CandidateSet); 1686 else 1687 AddConversionCandidate(Conv, FoundDecl, ActingContext, 1688 From, ToType, CandidateSet); 1689 } 1690 } 1691 } 1692 } 1693 1694 OverloadCandidateSet::iterator Best; 1695 switch (BestViableFunction(CandidateSet, From->getLocStart(), Best)) { 1696 case OR_Success: 1697 // Record the standard conversion we used and the conversion function. 1698 if (CXXConstructorDecl *Constructor 1699 = dyn_cast<CXXConstructorDecl>(Best->Function)) { 1700 // C++ [over.ics.user]p1: 1701 // If the user-defined conversion is specified by a 1702 // constructor (12.3.1), the initial standard conversion 1703 // sequence converts the source type to the type required by 1704 // the argument of the constructor. 1705 // 1706 QualType ThisType = Constructor->getThisType(Context); 1707 if (Best->Conversions[0].isEllipsis()) 1708 User.EllipsisConversion = true; 1709 else { 1710 User.Before = Best->Conversions[0].Standard; 1711 User.EllipsisConversion = false; 1712 } 1713 User.ConversionFunction = Constructor; 1714 User.After.setAsIdentityConversion(); 1715 User.After.setFromType( 1716 ThisType->getAs<PointerType>()->getPointeeType()); 1717 User.After.setAllToTypes(ToType); 1718 return OR_Success; 1719 } else if (CXXConversionDecl *Conversion 1720 = dyn_cast<CXXConversionDecl>(Best->Function)) { 1721 // C++ [over.ics.user]p1: 1722 // 1723 // [...] If the user-defined conversion is specified by a 1724 // conversion function (12.3.2), the initial standard 1725 // conversion sequence converts the source type to the 1726 // implicit object parameter of the conversion function. 1727 User.Before = Best->Conversions[0].Standard; 1728 User.ConversionFunction = Conversion; 1729 User.EllipsisConversion = false; 1730 1731 // C++ [over.ics.user]p2: 1732 // The second standard conversion sequence converts the 1733 // result of the user-defined conversion to the target type 1734 // for the sequence. Since an implicit conversion sequence 1735 // is an initialization, the special rules for 1736 // initialization by user-defined conversion apply when 1737 // selecting the best user-defined conversion for a 1738 // user-defined conversion sequence (see 13.3.3 and 1739 // 13.3.3.1). 1740 User.After = Best->FinalConversion; 1741 return OR_Success; 1742 } else { 1743 assert(false && "Not a constructor or conversion function?"); 1744 return OR_No_Viable_Function; 1745 } 1746 1747 case OR_No_Viable_Function: 1748 return OR_No_Viable_Function; 1749 case OR_Deleted: 1750 // No conversion here! We're done. 1751 return OR_Deleted; 1752 1753 case OR_Ambiguous: 1754 return OR_Ambiguous; 1755 } 1756 1757 return OR_No_Viable_Function; 1758} 1759 1760bool 1761Sema::DiagnoseMultipleUserDefinedConversion(Expr *From, QualType ToType) { 1762 ImplicitConversionSequence ICS; 1763 OverloadCandidateSet CandidateSet(From->getExprLoc()); 1764 OverloadingResult OvResult = 1765 IsUserDefinedConversion(From, ToType, ICS.UserDefined, 1766 CandidateSet, false); 1767 if (OvResult == OR_Ambiguous) 1768 Diag(From->getSourceRange().getBegin(), 1769 diag::err_typecheck_ambiguous_condition) 1770 << From->getType() << ToType << From->getSourceRange(); 1771 else if (OvResult == OR_No_Viable_Function && !CandidateSet.empty()) 1772 Diag(From->getSourceRange().getBegin(), 1773 diag::err_typecheck_nonviable_condition) 1774 << From->getType() << ToType << From->getSourceRange(); 1775 else 1776 return false; 1777 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, &From, 1); 1778 return true; 1779} 1780 1781/// CompareImplicitConversionSequences - Compare two implicit 1782/// conversion sequences to determine whether one is better than the 1783/// other or if they are indistinguishable (C++ 13.3.3.2). 1784ImplicitConversionSequence::CompareKind 1785Sema::CompareImplicitConversionSequences(const ImplicitConversionSequence& ICS1, 1786 const ImplicitConversionSequence& ICS2) 1787{ 1788 // (C++ 13.3.3.2p2): When comparing the basic forms of implicit 1789 // conversion sequences (as defined in 13.3.3.1) 1790 // -- a standard conversion sequence (13.3.3.1.1) is a better 1791 // conversion sequence than a user-defined conversion sequence or 1792 // an ellipsis conversion sequence, and 1793 // -- a user-defined conversion sequence (13.3.3.1.2) is a better 1794 // conversion sequence than an ellipsis conversion sequence 1795 // (13.3.3.1.3). 1796 // 1797 // C++0x [over.best.ics]p10: 1798 // For the purpose of ranking implicit conversion sequences as 1799 // described in 13.3.3.2, the ambiguous conversion sequence is 1800 // treated as a user-defined sequence that is indistinguishable 1801 // from any other user-defined conversion sequence. 1802 if (ICS1.getKindRank() < ICS2.getKindRank()) 1803 return ImplicitConversionSequence::Better; 1804 else if (ICS2.getKindRank() < ICS1.getKindRank()) 1805 return ImplicitConversionSequence::Worse; 1806 1807 // The following checks require both conversion sequences to be of 1808 // the same kind. 1809 if (ICS1.getKind() != ICS2.getKind()) 1810 return ImplicitConversionSequence::Indistinguishable; 1811 1812 // Two implicit conversion sequences of the same form are 1813 // indistinguishable conversion sequences unless one of the 1814 // following rules apply: (C++ 13.3.3.2p3): 1815 if (ICS1.isStandard()) 1816 return CompareStandardConversionSequences(ICS1.Standard, ICS2.Standard); 1817 else if (ICS1.isUserDefined()) { 1818 // User-defined conversion sequence U1 is a better conversion 1819 // sequence than another user-defined conversion sequence U2 if 1820 // they contain the same user-defined conversion function or 1821 // constructor and if the second standard conversion sequence of 1822 // U1 is better than the second standard conversion sequence of 1823 // U2 (C++ 13.3.3.2p3). 1824 if (ICS1.UserDefined.ConversionFunction == 1825 ICS2.UserDefined.ConversionFunction) 1826 return CompareStandardConversionSequences(ICS1.UserDefined.After, 1827 ICS2.UserDefined.After); 1828 } 1829 1830 return ImplicitConversionSequence::Indistinguishable; 1831} 1832 1833// Per 13.3.3.2p3, compare the given standard conversion sequences to 1834// determine if one is a proper subset of the other. 1835static ImplicitConversionSequence::CompareKind 1836compareStandardConversionSubsets(ASTContext &Context, 1837 const StandardConversionSequence& SCS1, 1838 const StandardConversionSequence& SCS2) { 1839 ImplicitConversionSequence::CompareKind Result 1840 = ImplicitConversionSequence::Indistinguishable; 1841 1842 if (SCS1.Second != SCS2.Second) { 1843 if (SCS1.Second == ICK_Identity) 1844 Result = ImplicitConversionSequence::Better; 1845 else if (SCS2.Second == ICK_Identity) 1846 Result = ImplicitConversionSequence::Worse; 1847 else 1848 return ImplicitConversionSequence::Indistinguishable; 1849 } else if (!Context.hasSameType(SCS1.getToType(1), SCS2.getToType(1))) 1850 return ImplicitConversionSequence::Indistinguishable; 1851 1852 if (SCS1.Third == SCS2.Third) { 1853 return Context.hasSameType(SCS1.getToType(2), SCS2.getToType(2))? Result 1854 : ImplicitConversionSequence::Indistinguishable; 1855 } 1856 1857 if (SCS1.Third == ICK_Identity) 1858 return Result == ImplicitConversionSequence::Worse 1859 ? ImplicitConversionSequence::Indistinguishable 1860 : ImplicitConversionSequence::Better; 1861 1862 if (SCS2.Third == ICK_Identity) 1863 return Result == ImplicitConversionSequence::Better 1864 ? ImplicitConversionSequence::Indistinguishable 1865 : ImplicitConversionSequence::Worse; 1866 1867 return ImplicitConversionSequence::Indistinguishable; 1868} 1869 1870/// CompareStandardConversionSequences - Compare two standard 1871/// conversion sequences to determine whether one is better than the 1872/// other or if they are indistinguishable (C++ 13.3.3.2p3). 1873ImplicitConversionSequence::CompareKind 1874Sema::CompareStandardConversionSequences(const StandardConversionSequence& SCS1, 1875 const StandardConversionSequence& SCS2) 1876{ 1877 // Standard conversion sequence S1 is a better conversion sequence 1878 // than standard conversion sequence S2 if (C++ 13.3.3.2p3): 1879 1880 // -- S1 is a proper subsequence of S2 (comparing the conversion 1881 // sequences in the canonical form defined by 13.3.3.1.1, 1882 // excluding any Lvalue Transformation; the identity conversion 1883 // sequence is considered to be a subsequence of any 1884 // non-identity conversion sequence) or, if not that, 1885 if (ImplicitConversionSequence::CompareKind CK 1886 = compareStandardConversionSubsets(Context, SCS1, SCS2)) 1887 return CK; 1888 1889 // -- the rank of S1 is better than the rank of S2 (by the rules 1890 // defined below), or, if not that, 1891 ImplicitConversionRank Rank1 = SCS1.getRank(); 1892 ImplicitConversionRank Rank2 = SCS2.getRank(); 1893 if (Rank1 < Rank2) 1894 return ImplicitConversionSequence::Better; 1895 else if (Rank2 < Rank1) 1896 return ImplicitConversionSequence::Worse; 1897 1898 // (C++ 13.3.3.2p4): Two conversion sequences with the same rank 1899 // are indistinguishable unless one of the following rules 1900 // applies: 1901 1902 // A conversion that is not a conversion of a pointer, or 1903 // pointer to member, to bool is better than another conversion 1904 // that is such a conversion. 1905 if (SCS1.isPointerConversionToBool() != SCS2.isPointerConversionToBool()) 1906 return SCS2.isPointerConversionToBool() 1907 ? ImplicitConversionSequence::Better 1908 : ImplicitConversionSequence::Worse; 1909 1910 // C++ [over.ics.rank]p4b2: 1911 // 1912 // If class B is derived directly or indirectly from class A, 1913 // conversion of B* to A* is better than conversion of B* to 1914 // void*, and conversion of A* to void* is better than conversion 1915 // of B* to void*. 1916 bool SCS1ConvertsToVoid 1917 = SCS1.isPointerConversionToVoidPointer(Context); 1918 bool SCS2ConvertsToVoid 1919 = SCS2.isPointerConversionToVoidPointer(Context); 1920 if (SCS1ConvertsToVoid != SCS2ConvertsToVoid) { 1921 // Exactly one of the conversion sequences is a conversion to 1922 // a void pointer; it's the worse conversion. 1923 return SCS2ConvertsToVoid ? ImplicitConversionSequence::Better 1924 : ImplicitConversionSequence::Worse; 1925 } else if (!SCS1ConvertsToVoid && !SCS2ConvertsToVoid) { 1926 // Neither conversion sequence converts to a void pointer; compare 1927 // their derived-to-base conversions. 1928 if (ImplicitConversionSequence::CompareKind DerivedCK 1929 = CompareDerivedToBaseConversions(SCS1, SCS2)) 1930 return DerivedCK; 1931 } else if (SCS1ConvertsToVoid && SCS2ConvertsToVoid) { 1932 // Both conversion sequences are conversions to void 1933 // pointers. Compare the source types to determine if there's an 1934 // inheritance relationship in their sources. 1935 QualType FromType1 = SCS1.getFromType(); 1936 QualType FromType2 = SCS2.getFromType(); 1937 1938 // Adjust the types we're converting from via the array-to-pointer 1939 // conversion, if we need to. 1940 if (SCS1.First == ICK_Array_To_Pointer) 1941 FromType1 = Context.getArrayDecayedType(FromType1); 1942 if (SCS2.First == ICK_Array_To_Pointer) 1943 FromType2 = Context.getArrayDecayedType(FromType2); 1944 1945 QualType FromPointee1 1946 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1947 QualType FromPointee2 1948 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1949 1950 if (IsDerivedFrom(FromPointee2, FromPointee1)) 1951 return ImplicitConversionSequence::Better; 1952 else if (IsDerivedFrom(FromPointee1, FromPointee2)) 1953 return ImplicitConversionSequence::Worse; 1954 1955 // Objective-C++: If one interface is more specific than the 1956 // other, it is the better one. 1957 const ObjCInterfaceType* FromIface1 = FromPointee1->getAs<ObjCInterfaceType>(); 1958 const ObjCInterfaceType* FromIface2 = FromPointee2->getAs<ObjCInterfaceType>(); 1959 if (FromIface1 && FromIface1) { 1960 if (Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 1961 return ImplicitConversionSequence::Better; 1962 else if (Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 1963 return ImplicitConversionSequence::Worse; 1964 } 1965 } 1966 1967 // Compare based on qualification conversions (C++ 13.3.3.2p3, 1968 // bullet 3). 1969 if (ImplicitConversionSequence::CompareKind QualCK 1970 = CompareQualificationConversions(SCS1, SCS2)) 1971 return QualCK; 1972 1973 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding) { 1974 // C++0x [over.ics.rank]p3b4: 1975 // -- S1 and S2 are reference bindings (8.5.3) and neither refers to an 1976 // implicit object parameter of a non-static member function declared 1977 // without a ref-qualifier, and S1 binds an rvalue reference to an 1978 // rvalue and S2 binds an lvalue reference. 1979 // FIXME: We don't know if we're dealing with the implicit object parameter, 1980 // or if the member function in this case has a ref qualifier. 1981 // (Of course, we don't have ref qualifiers yet.) 1982 if (SCS1.RRefBinding != SCS2.RRefBinding) 1983 return SCS1.RRefBinding ? ImplicitConversionSequence::Better 1984 : ImplicitConversionSequence::Worse; 1985 1986 // C++ [over.ics.rank]p3b4: 1987 // -- S1 and S2 are reference bindings (8.5.3), and the types to 1988 // which the references refer are the same type except for 1989 // top-level cv-qualifiers, and the type to which the reference 1990 // initialized by S2 refers is more cv-qualified than the type 1991 // to which the reference initialized by S1 refers. 1992 QualType T1 = SCS1.getToType(2); 1993 QualType T2 = SCS2.getToType(2); 1994 T1 = Context.getCanonicalType(T1); 1995 T2 = Context.getCanonicalType(T2); 1996 Qualifiers T1Quals, T2Quals; 1997 QualType UnqualT1 = Context.getUnqualifiedArrayType(T1, T1Quals); 1998 QualType UnqualT2 = Context.getUnqualifiedArrayType(T2, T2Quals); 1999 if (UnqualT1 == UnqualT2) { 2000 // If the type is an array type, promote the element qualifiers to the type 2001 // for comparison. 2002 if (isa<ArrayType>(T1) && T1Quals) 2003 T1 = Context.getQualifiedType(UnqualT1, T1Quals); 2004 if (isa<ArrayType>(T2) && T2Quals) 2005 T2 = Context.getQualifiedType(UnqualT2, T2Quals); 2006 if (T2.isMoreQualifiedThan(T1)) 2007 return ImplicitConversionSequence::Better; 2008 else if (T1.isMoreQualifiedThan(T2)) 2009 return ImplicitConversionSequence::Worse; 2010 } 2011 } 2012 2013 return ImplicitConversionSequence::Indistinguishable; 2014} 2015 2016/// CompareQualificationConversions - Compares two standard conversion 2017/// sequences to determine whether they can be ranked based on their 2018/// qualification conversions (C++ 13.3.3.2p3 bullet 3). 2019ImplicitConversionSequence::CompareKind 2020Sema::CompareQualificationConversions(const StandardConversionSequence& SCS1, 2021 const StandardConversionSequence& SCS2) { 2022 // C++ 13.3.3.2p3: 2023 // -- S1 and S2 differ only in their qualification conversion and 2024 // yield similar types T1 and T2 (C++ 4.4), respectively, and the 2025 // cv-qualification signature of type T1 is a proper subset of 2026 // the cv-qualification signature of type T2, and S1 is not the 2027 // deprecated string literal array-to-pointer conversion (4.2). 2028 if (SCS1.First != SCS2.First || SCS1.Second != SCS2.Second || 2029 SCS1.Third != SCS2.Third || SCS1.Third != ICK_Qualification) 2030 return ImplicitConversionSequence::Indistinguishable; 2031 2032 // FIXME: the example in the standard doesn't use a qualification 2033 // conversion (!) 2034 QualType T1 = SCS1.getToType(2); 2035 QualType T2 = SCS2.getToType(2); 2036 T1 = Context.getCanonicalType(T1); 2037 T2 = Context.getCanonicalType(T2); 2038 Qualifiers T1Quals, T2Quals; 2039 QualType UnqualT1 = Context.getUnqualifiedArrayType(T1, T1Quals); 2040 QualType UnqualT2 = Context.getUnqualifiedArrayType(T2, T2Quals); 2041 2042 // If the types are the same, we won't learn anything by unwrapped 2043 // them. 2044 if (UnqualT1 == UnqualT2) 2045 return ImplicitConversionSequence::Indistinguishable; 2046 2047 // If the type is an array type, promote the element qualifiers to the type 2048 // for comparison. 2049 if (isa<ArrayType>(T1) && T1Quals) 2050 T1 = Context.getQualifiedType(UnqualT1, T1Quals); 2051 if (isa<ArrayType>(T2) && T2Quals) 2052 T2 = Context.getQualifiedType(UnqualT2, T2Quals); 2053 2054 ImplicitConversionSequence::CompareKind Result 2055 = ImplicitConversionSequence::Indistinguishable; 2056 while (UnwrapSimilarPointerTypes(T1, T2)) { 2057 // Within each iteration of the loop, we check the qualifiers to 2058 // determine if this still looks like a qualification 2059 // conversion. Then, if all is well, we unwrap one more level of 2060 // pointers or pointers-to-members and do it all again 2061 // until there are no more pointers or pointers-to-members left 2062 // to unwrap. This essentially mimics what 2063 // IsQualificationConversion does, but here we're checking for a 2064 // strict subset of qualifiers. 2065 if (T1.getCVRQualifiers() == T2.getCVRQualifiers()) 2066 // The qualifiers are the same, so this doesn't tell us anything 2067 // about how the sequences rank. 2068 ; 2069 else if (T2.isMoreQualifiedThan(T1)) { 2070 // T1 has fewer qualifiers, so it could be the better sequence. 2071 if (Result == ImplicitConversionSequence::Worse) 2072 // Neither has qualifiers that are a subset of the other's 2073 // qualifiers. 2074 return ImplicitConversionSequence::Indistinguishable; 2075 2076 Result = ImplicitConversionSequence::Better; 2077 } else if (T1.isMoreQualifiedThan(T2)) { 2078 // T2 has fewer qualifiers, so it could be the better sequence. 2079 if (Result == ImplicitConversionSequence::Better) 2080 // Neither has qualifiers that are a subset of the other's 2081 // qualifiers. 2082 return ImplicitConversionSequence::Indistinguishable; 2083 2084 Result = ImplicitConversionSequence::Worse; 2085 } else { 2086 // Qualifiers are disjoint. 2087 return ImplicitConversionSequence::Indistinguishable; 2088 } 2089 2090 // If the types after this point are equivalent, we're done. 2091 if (Context.hasSameUnqualifiedType(T1, T2)) 2092 break; 2093 } 2094 2095 // Check that the winning standard conversion sequence isn't using 2096 // the deprecated string literal array to pointer conversion. 2097 switch (Result) { 2098 case ImplicitConversionSequence::Better: 2099 if (SCS1.DeprecatedStringLiteralToCharPtr) 2100 Result = ImplicitConversionSequence::Indistinguishable; 2101 break; 2102 2103 case ImplicitConversionSequence::Indistinguishable: 2104 break; 2105 2106 case ImplicitConversionSequence::Worse: 2107 if (SCS2.DeprecatedStringLiteralToCharPtr) 2108 Result = ImplicitConversionSequence::Indistinguishable; 2109 break; 2110 } 2111 2112 return Result; 2113} 2114 2115/// CompareDerivedToBaseConversions - Compares two standard conversion 2116/// sequences to determine whether they can be ranked based on their 2117/// various kinds of derived-to-base conversions (C++ 2118/// [over.ics.rank]p4b3). As part of these checks, we also look at 2119/// conversions between Objective-C interface types. 2120ImplicitConversionSequence::CompareKind 2121Sema::CompareDerivedToBaseConversions(const StandardConversionSequence& SCS1, 2122 const StandardConversionSequence& SCS2) { 2123 QualType FromType1 = SCS1.getFromType(); 2124 QualType ToType1 = SCS1.getToType(1); 2125 QualType FromType2 = SCS2.getFromType(); 2126 QualType ToType2 = SCS2.getToType(1); 2127 2128 // Adjust the types we're converting from via the array-to-pointer 2129 // conversion, if we need to. 2130 if (SCS1.First == ICK_Array_To_Pointer) 2131 FromType1 = Context.getArrayDecayedType(FromType1); 2132 if (SCS2.First == ICK_Array_To_Pointer) 2133 FromType2 = Context.getArrayDecayedType(FromType2); 2134 2135 // Canonicalize all of the types. 2136 FromType1 = Context.getCanonicalType(FromType1); 2137 ToType1 = Context.getCanonicalType(ToType1); 2138 FromType2 = Context.getCanonicalType(FromType2); 2139 ToType2 = Context.getCanonicalType(ToType2); 2140 2141 // C++ [over.ics.rank]p4b3: 2142 // 2143 // If class B is derived directly or indirectly from class A and 2144 // class C is derived directly or indirectly from B, 2145 // 2146 // For Objective-C, we let A, B, and C also be Objective-C 2147 // interfaces. 2148 2149 // Compare based on pointer conversions. 2150 if (SCS1.Second == ICK_Pointer_Conversion && 2151 SCS2.Second == ICK_Pointer_Conversion && 2152 /*FIXME: Remove if Objective-C id conversions get their own rank*/ 2153 FromType1->isPointerType() && FromType2->isPointerType() && 2154 ToType1->isPointerType() && ToType2->isPointerType()) { 2155 QualType FromPointee1 2156 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2157 QualType ToPointee1 2158 = ToType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2159 QualType FromPointee2 2160 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2161 QualType ToPointee2 2162 = ToType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2163 2164 const ObjCInterfaceType* FromIface1 = FromPointee1->getAs<ObjCInterfaceType>(); 2165 const ObjCInterfaceType* FromIface2 = FromPointee2->getAs<ObjCInterfaceType>(); 2166 const ObjCInterfaceType* ToIface1 = ToPointee1->getAs<ObjCInterfaceType>(); 2167 const ObjCInterfaceType* ToIface2 = ToPointee2->getAs<ObjCInterfaceType>(); 2168 2169 // -- conversion of C* to B* is better than conversion of C* to A*, 2170 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 2171 if (IsDerivedFrom(ToPointee1, ToPointee2)) 2172 return ImplicitConversionSequence::Better; 2173 else if (IsDerivedFrom(ToPointee2, ToPointee1)) 2174 return ImplicitConversionSequence::Worse; 2175 2176 if (ToIface1 && ToIface2) { 2177 if (Context.canAssignObjCInterfaces(ToIface2, ToIface1)) 2178 return ImplicitConversionSequence::Better; 2179 else if (Context.canAssignObjCInterfaces(ToIface1, ToIface2)) 2180 return ImplicitConversionSequence::Worse; 2181 } 2182 } 2183 2184 // -- conversion of B* to A* is better than conversion of C* to A*, 2185 if (FromPointee1 != FromPointee2 && ToPointee1 == ToPointee2) { 2186 if (IsDerivedFrom(FromPointee2, FromPointee1)) 2187 return ImplicitConversionSequence::Better; 2188 else if (IsDerivedFrom(FromPointee1, FromPointee2)) 2189 return ImplicitConversionSequence::Worse; 2190 2191 if (FromIface1 && FromIface2) { 2192 if (Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 2193 return ImplicitConversionSequence::Better; 2194 else if (Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 2195 return ImplicitConversionSequence::Worse; 2196 } 2197 } 2198 } 2199 2200 // Ranking of member-pointer types. 2201 if (SCS1.Second == ICK_Pointer_Member && SCS2.Second == ICK_Pointer_Member && 2202 FromType1->isMemberPointerType() && FromType2->isMemberPointerType() && 2203 ToType1->isMemberPointerType() && ToType2->isMemberPointerType()) { 2204 const MemberPointerType * FromMemPointer1 = 2205 FromType1->getAs<MemberPointerType>(); 2206 const MemberPointerType * ToMemPointer1 = 2207 ToType1->getAs<MemberPointerType>(); 2208 const MemberPointerType * FromMemPointer2 = 2209 FromType2->getAs<MemberPointerType>(); 2210 const MemberPointerType * ToMemPointer2 = 2211 ToType2->getAs<MemberPointerType>(); 2212 const Type *FromPointeeType1 = FromMemPointer1->getClass(); 2213 const Type *ToPointeeType1 = ToMemPointer1->getClass(); 2214 const Type *FromPointeeType2 = FromMemPointer2->getClass(); 2215 const Type *ToPointeeType2 = ToMemPointer2->getClass(); 2216 QualType FromPointee1 = QualType(FromPointeeType1, 0).getUnqualifiedType(); 2217 QualType ToPointee1 = QualType(ToPointeeType1, 0).getUnqualifiedType(); 2218 QualType FromPointee2 = QualType(FromPointeeType2, 0).getUnqualifiedType(); 2219 QualType ToPointee2 = QualType(ToPointeeType2, 0).getUnqualifiedType(); 2220 // conversion of A::* to B::* is better than conversion of A::* to C::*, 2221 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 2222 if (IsDerivedFrom(ToPointee1, ToPointee2)) 2223 return ImplicitConversionSequence::Worse; 2224 else if (IsDerivedFrom(ToPointee2, ToPointee1)) 2225 return ImplicitConversionSequence::Better; 2226 } 2227 // conversion of B::* to C::* is better than conversion of A::* to C::* 2228 if (ToPointee1 == ToPointee2 && FromPointee1 != FromPointee2) { 2229 if (IsDerivedFrom(FromPointee1, FromPointee2)) 2230 return ImplicitConversionSequence::Better; 2231 else if (IsDerivedFrom(FromPointee2, FromPointee1)) 2232 return ImplicitConversionSequence::Worse; 2233 } 2234 } 2235 2236 if (SCS1.Second == ICK_Derived_To_Base) { 2237 // -- conversion of C to B is better than conversion of C to A, 2238 // -- binding of an expression of type C to a reference of type 2239 // B& is better than binding an expression of type C to a 2240 // reference of type A&, 2241 if (Context.hasSameUnqualifiedType(FromType1, FromType2) && 2242 !Context.hasSameUnqualifiedType(ToType1, ToType2)) { 2243 if (IsDerivedFrom(ToType1, ToType2)) 2244 return ImplicitConversionSequence::Better; 2245 else if (IsDerivedFrom(ToType2, ToType1)) 2246 return ImplicitConversionSequence::Worse; 2247 } 2248 2249 // -- conversion of B to A is better than conversion of C to A. 2250 // -- binding of an expression of type B to a reference of type 2251 // A& is better than binding an expression of type C to a 2252 // reference of type A&, 2253 if (!Context.hasSameUnqualifiedType(FromType1, FromType2) && 2254 Context.hasSameUnqualifiedType(ToType1, ToType2)) { 2255 if (IsDerivedFrom(FromType2, FromType1)) 2256 return ImplicitConversionSequence::Better; 2257 else if (IsDerivedFrom(FromType1, FromType2)) 2258 return ImplicitConversionSequence::Worse; 2259 } 2260 } 2261 2262 return ImplicitConversionSequence::Indistinguishable; 2263} 2264 2265/// CompareReferenceRelationship - Compare the two types T1 and T2 to 2266/// determine whether they are reference-related, 2267/// reference-compatible, reference-compatible with added 2268/// qualification, or incompatible, for use in C++ initialization by 2269/// reference (C++ [dcl.ref.init]p4). Neither type can be a reference 2270/// type, and the first type (T1) is the pointee type of the reference 2271/// type being initialized. 2272Sema::ReferenceCompareResult 2273Sema::CompareReferenceRelationship(SourceLocation Loc, 2274 QualType OrigT1, QualType OrigT2, 2275 bool& DerivedToBase) { 2276 assert(!OrigT1->isReferenceType() && 2277 "T1 must be the pointee type of the reference type"); 2278 assert(!OrigT2->isReferenceType() && "T2 cannot be a reference type"); 2279 2280 QualType T1 = Context.getCanonicalType(OrigT1); 2281 QualType T2 = Context.getCanonicalType(OrigT2); 2282 Qualifiers T1Quals, T2Quals; 2283 QualType UnqualT1 = Context.getUnqualifiedArrayType(T1, T1Quals); 2284 QualType UnqualT2 = Context.getUnqualifiedArrayType(T2, T2Quals); 2285 2286 // C++ [dcl.init.ref]p4: 2287 // Given types "cv1 T1" and "cv2 T2," "cv1 T1" is 2288 // reference-related to "cv2 T2" if T1 is the same type as T2, or 2289 // T1 is a base class of T2. 2290 if (UnqualT1 == UnqualT2) 2291 DerivedToBase = false; 2292 else if (!RequireCompleteType(Loc, OrigT1, PDiag()) && 2293 !RequireCompleteType(Loc, OrigT2, PDiag()) && 2294 IsDerivedFrom(UnqualT2, UnqualT1)) 2295 DerivedToBase = true; 2296 else 2297 return Ref_Incompatible; 2298 2299 // At this point, we know that T1 and T2 are reference-related (at 2300 // least). 2301 2302 // If the type is an array type, promote the element qualifiers to the type 2303 // for comparison. 2304 if (isa<ArrayType>(T1) && T1Quals) 2305 T1 = Context.getQualifiedType(UnqualT1, T1Quals); 2306 if (isa<ArrayType>(T2) && T2Quals) 2307 T2 = Context.getQualifiedType(UnqualT2, T2Quals); 2308 2309 // C++ [dcl.init.ref]p4: 2310 // "cv1 T1" is reference-compatible with "cv2 T2" if T1 is 2311 // reference-related to T2 and cv1 is the same cv-qualification 2312 // as, or greater cv-qualification than, cv2. For purposes of 2313 // overload resolution, cases for which cv1 is greater 2314 // cv-qualification than cv2 are identified as 2315 // reference-compatible with added qualification (see 13.3.3.2). 2316 if (T1Quals.getCVRQualifiers() == T2Quals.getCVRQualifiers()) 2317 return Ref_Compatible; 2318 else if (T1.isMoreQualifiedThan(T2)) 2319 return Ref_Compatible_With_Added_Qualification; 2320 else 2321 return Ref_Related; 2322} 2323 2324/// \brief Compute an implicit conversion sequence for reference 2325/// initialization. 2326static ImplicitConversionSequence 2327TryReferenceInit(Sema &S, Expr *&Init, QualType DeclType, 2328 SourceLocation DeclLoc, 2329 bool SuppressUserConversions, 2330 bool AllowExplicit) { 2331 assert(DeclType->isReferenceType() && "Reference init needs a reference"); 2332 2333 // Most paths end in a failed conversion. 2334 ImplicitConversionSequence ICS; 2335 ICS.setBad(BadConversionSequence::no_conversion, Init, DeclType); 2336 2337 QualType T1 = DeclType->getAs<ReferenceType>()->getPointeeType(); 2338 QualType T2 = Init->getType(); 2339 2340 // If the initializer is the address of an overloaded function, try 2341 // to resolve the overloaded function. If all goes well, T2 is the 2342 // type of the resulting function. 2343 if (S.Context.getCanonicalType(T2) == S.Context.OverloadTy) { 2344 DeclAccessPair Found; 2345 if (FunctionDecl *Fn = S.ResolveAddressOfOverloadedFunction(Init, DeclType, 2346 false, Found)) 2347 T2 = Fn->getType(); 2348 } 2349 2350 // Compute some basic properties of the types and the initializer. 2351 bool isRValRef = DeclType->isRValueReferenceType(); 2352 bool DerivedToBase = false; 2353 Expr::isLvalueResult InitLvalue = Init->isLvalue(S.Context); 2354 Sema::ReferenceCompareResult RefRelationship 2355 = S.CompareReferenceRelationship(DeclLoc, T1, T2, DerivedToBase); 2356 2357 2358 // C++ [over.ics.ref]p3: 2359 // Except for an implicit object parameter, for which see 13.3.1, 2360 // a standard conversion sequence cannot be formed if it requires 2361 // binding an lvalue reference to non-const to an rvalue or 2362 // binding an rvalue reference to an lvalue. 2363 // 2364 // FIXME: DPG doesn't trust this code. It seems far too early to 2365 // abort because of a binding of an rvalue reference to an lvalue. 2366 if (isRValRef && InitLvalue == Expr::LV_Valid) 2367 return ICS; 2368 2369 // C++0x [dcl.init.ref]p16: 2370 // A reference to type "cv1 T1" is initialized by an expression 2371 // of type "cv2 T2" as follows: 2372 2373 // -- If the initializer expression 2374 // -- is an lvalue (but is not a bit-field), and "cv1 T1" is 2375 // reference-compatible with "cv2 T2," or 2376 // 2377 // Per C++ [over.ics.ref]p4, we don't check the bit-field property here. 2378 if (InitLvalue == Expr::LV_Valid && 2379 RefRelationship >= Sema::Ref_Compatible_With_Added_Qualification) { 2380 // C++ [over.ics.ref]p1: 2381 // When a parameter of reference type binds directly (8.5.3) 2382 // to an argument expression, the implicit conversion sequence 2383 // is the identity conversion, unless the argument expression 2384 // has a type that is a derived class of the parameter type, 2385 // in which case the implicit conversion sequence is a 2386 // derived-to-base Conversion (13.3.3.1). 2387 ICS.setStandard(); 2388 ICS.Standard.First = ICK_Identity; 2389 ICS.Standard.Second = DerivedToBase? ICK_Derived_To_Base : ICK_Identity; 2390 ICS.Standard.Third = ICK_Identity; 2391 ICS.Standard.FromTypePtr = T2.getAsOpaquePtr(); 2392 ICS.Standard.setToType(0, T2); 2393 ICS.Standard.setToType(1, T1); 2394 ICS.Standard.setToType(2, T1); 2395 ICS.Standard.ReferenceBinding = true; 2396 ICS.Standard.DirectBinding = true; 2397 ICS.Standard.RRefBinding = false; 2398 ICS.Standard.CopyConstructor = 0; 2399 2400 // Nothing more to do: the inaccessibility/ambiguity check for 2401 // derived-to-base conversions is suppressed when we're 2402 // computing the implicit conversion sequence (C++ 2403 // [over.best.ics]p2). 2404 return ICS; 2405 } 2406 2407 // -- has a class type (i.e., T2 is a class type), where T1 is 2408 // not reference-related to T2, and can be implicitly 2409 // converted to an lvalue of type "cv3 T3," where "cv1 T1" 2410 // is reference-compatible with "cv3 T3" 92) (this 2411 // conversion is selected by enumerating the applicable 2412 // conversion functions (13.3.1.6) and choosing the best 2413 // one through overload resolution (13.3)), 2414 if (!isRValRef && !SuppressUserConversions && T2->isRecordType() && 2415 !S.RequireCompleteType(DeclLoc, T2, 0) && 2416 RefRelationship == Sema::Ref_Incompatible) { 2417 CXXRecordDecl *T2RecordDecl 2418 = dyn_cast<CXXRecordDecl>(T2->getAs<RecordType>()->getDecl()); 2419 2420 OverloadCandidateSet CandidateSet(DeclLoc); 2421 const UnresolvedSetImpl *Conversions 2422 = T2RecordDecl->getVisibleConversionFunctions(); 2423 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 2424 E = Conversions->end(); I != E; ++I) { 2425 NamedDecl *D = *I; 2426 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(D->getDeclContext()); 2427 if (isa<UsingShadowDecl>(D)) 2428 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 2429 2430 FunctionTemplateDecl *ConvTemplate 2431 = dyn_cast<FunctionTemplateDecl>(D); 2432 CXXConversionDecl *Conv; 2433 if (ConvTemplate) 2434 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 2435 else 2436 Conv = cast<CXXConversionDecl>(D); 2437 2438 // If the conversion function doesn't return a reference type, 2439 // it can't be considered for this conversion. 2440 if (Conv->getConversionType()->isLValueReferenceType() && 2441 (AllowExplicit || !Conv->isExplicit())) { 2442 if (ConvTemplate) 2443 S.AddTemplateConversionCandidate(ConvTemplate, I.getPair(), ActingDC, 2444 Init, DeclType, CandidateSet); 2445 else 2446 S.AddConversionCandidate(Conv, I.getPair(), ActingDC, Init, 2447 DeclType, CandidateSet); 2448 } 2449 } 2450 2451 OverloadCandidateSet::iterator Best; 2452 switch (S.BestViableFunction(CandidateSet, DeclLoc, Best)) { 2453 case OR_Success: 2454 // C++ [over.ics.ref]p1: 2455 // 2456 // [...] If the parameter binds directly to the result of 2457 // applying a conversion function to the argument 2458 // expression, the implicit conversion sequence is a 2459 // user-defined conversion sequence (13.3.3.1.2), with the 2460 // second standard conversion sequence either an identity 2461 // conversion or, if the conversion function returns an 2462 // entity of a type that is a derived class of the parameter 2463 // type, a derived-to-base Conversion. 2464 if (!Best->FinalConversion.DirectBinding) 2465 break; 2466 2467 ICS.setUserDefined(); 2468 ICS.UserDefined.Before = Best->Conversions[0].Standard; 2469 ICS.UserDefined.After = Best->FinalConversion; 2470 ICS.UserDefined.ConversionFunction = Best->Function; 2471 ICS.UserDefined.EllipsisConversion = false; 2472 assert(ICS.UserDefined.After.ReferenceBinding && 2473 ICS.UserDefined.After.DirectBinding && 2474 "Expected a direct reference binding!"); 2475 return ICS; 2476 2477 case OR_Ambiguous: 2478 ICS.setAmbiguous(); 2479 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 2480 Cand != CandidateSet.end(); ++Cand) 2481 if (Cand->Viable) 2482 ICS.Ambiguous.addConversion(Cand->Function); 2483 return ICS; 2484 2485 case OR_No_Viable_Function: 2486 case OR_Deleted: 2487 // There was no suitable conversion, or we found a deleted 2488 // conversion; continue with other checks. 2489 break; 2490 } 2491 } 2492 2493 // -- Otherwise, the reference shall be to a non-volatile const 2494 // type (i.e., cv1 shall be const), or the reference shall be an 2495 // rvalue reference and the initializer expression shall be an rvalue. 2496 // 2497 // We actually handle one oddity of C++ [over.ics.ref] at this 2498 // point, which is that, due to p2 (which short-circuits reference 2499 // binding by only attempting a simple conversion for non-direct 2500 // bindings) and p3's strange wording, we allow a const volatile 2501 // reference to bind to an rvalue. Hence the check for the presence 2502 // of "const" rather than checking for "const" being the only 2503 // qualifier. 2504 if (!isRValRef && !T1.isConstQualified()) 2505 return ICS; 2506 2507 // -- if T2 is a class type and 2508 // -- the initializer expression is an rvalue and "cv1 T1" 2509 // is reference-compatible with "cv2 T2," or 2510 // 2511 // -- T1 is not reference-related to T2 and the initializer 2512 // expression can be implicitly converted to an rvalue 2513 // of type "cv3 T3" (this conversion is selected by 2514 // enumerating the applicable conversion functions 2515 // (13.3.1.6) and choosing the best one through overload 2516 // resolution (13.3)), 2517 // 2518 // then the reference is bound to the initializer 2519 // expression rvalue in the first case and to the object 2520 // that is the result of the conversion in the second case 2521 // (or, in either case, to the appropriate base class 2522 // subobject of the object). 2523 // 2524 // We're only checking the first case here, which is a direct 2525 // binding in C++0x but not in C++03. 2526 if (InitLvalue != Expr::LV_Valid && T2->isRecordType() && 2527 RefRelationship >= Sema::Ref_Compatible_With_Added_Qualification) { 2528 ICS.setStandard(); 2529 ICS.Standard.First = ICK_Identity; 2530 ICS.Standard.Second = DerivedToBase? ICK_Derived_To_Base : ICK_Identity; 2531 ICS.Standard.Third = ICK_Identity; 2532 ICS.Standard.FromTypePtr = T2.getAsOpaquePtr(); 2533 ICS.Standard.setToType(0, T2); 2534 ICS.Standard.setToType(1, T1); 2535 ICS.Standard.setToType(2, T1); 2536 ICS.Standard.ReferenceBinding = true; 2537 ICS.Standard.DirectBinding = S.getLangOptions().CPlusPlus0x; 2538 ICS.Standard.RRefBinding = isRValRef; 2539 ICS.Standard.CopyConstructor = 0; 2540 return ICS; 2541 } 2542 2543 // -- Otherwise, a temporary of type "cv1 T1" is created and 2544 // initialized from the initializer expression using the 2545 // rules for a non-reference copy initialization (8.5). The 2546 // reference is then bound to the temporary. If T1 is 2547 // reference-related to T2, cv1 must be the same 2548 // cv-qualification as, or greater cv-qualification than, 2549 // cv2; otherwise, the program is ill-formed. 2550 if (RefRelationship == Sema::Ref_Related) { 2551 // If cv1 == cv2 or cv1 is a greater cv-qualified than cv2, then 2552 // we would be reference-compatible or reference-compatible with 2553 // added qualification. But that wasn't the case, so the reference 2554 // initialization fails. 2555 return ICS; 2556 } 2557 2558 // If at least one of the types is a class type, the types are not 2559 // related, and we aren't allowed any user conversions, the 2560 // reference binding fails. This case is important for breaking 2561 // recursion, since TryImplicitConversion below will attempt to 2562 // create a temporary through the use of a copy constructor. 2563 if (SuppressUserConversions && RefRelationship == Sema::Ref_Incompatible && 2564 (T1->isRecordType() || T2->isRecordType())) 2565 return ICS; 2566 2567 // C++ [over.ics.ref]p2: 2568 // When a parameter of reference type is not bound directly to 2569 // an argument expression, the conversion sequence is the one 2570 // required to convert the argument expression to the 2571 // underlying type of the reference according to 2572 // 13.3.3.1. Conceptually, this conversion sequence corresponds 2573 // to copy-initializing a temporary of the underlying type with 2574 // the argument expression. Any difference in top-level 2575 // cv-qualification is subsumed by the initialization itself 2576 // and does not constitute a conversion. 2577 ICS = S.TryImplicitConversion(Init, T1, SuppressUserConversions, 2578 /*AllowExplicit=*/false, 2579 /*InOverloadResolution=*/false); 2580 2581 // Of course, that's still a reference binding. 2582 if (ICS.isStandard()) { 2583 ICS.Standard.ReferenceBinding = true; 2584 ICS.Standard.RRefBinding = isRValRef; 2585 } else if (ICS.isUserDefined()) { 2586 ICS.UserDefined.After.ReferenceBinding = true; 2587 ICS.UserDefined.After.RRefBinding = isRValRef; 2588 } 2589 return ICS; 2590} 2591 2592/// TryCopyInitialization - Try to copy-initialize a value of type 2593/// ToType from the expression From. Return the implicit conversion 2594/// sequence required to pass this argument, which may be a bad 2595/// conversion sequence (meaning that the argument cannot be passed to 2596/// a parameter of this type). If @p SuppressUserConversions, then we 2597/// do not permit any user-defined conversion sequences. 2598static ImplicitConversionSequence 2599TryCopyInitialization(Sema &S, Expr *From, QualType ToType, 2600 bool SuppressUserConversions, 2601 bool InOverloadResolution) { 2602 if (ToType->isReferenceType()) 2603 return TryReferenceInit(S, From, ToType, 2604 /*FIXME:*/From->getLocStart(), 2605 SuppressUserConversions, 2606 /*AllowExplicit=*/false); 2607 2608 return S.TryImplicitConversion(From, ToType, 2609 SuppressUserConversions, 2610 /*AllowExplicit=*/false, 2611 InOverloadResolution); 2612} 2613 2614/// TryObjectArgumentInitialization - Try to initialize the object 2615/// parameter of the given member function (@c Method) from the 2616/// expression @p From. 2617ImplicitConversionSequence 2618Sema::TryObjectArgumentInitialization(QualType OrigFromType, 2619 CXXMethodDecl *Method, 2620 CXXRecordDecl *ActingContext) { 2621 QualType ClassType = Context.getTypeDeclType(ActingContext); 2622 // [class.dtor]p2: A destructor can be invoked for a const, volatile or 2623 // const volatile object. 2624 unsigned Quals = isa<CXXDestructorDecl>(Method) ? 2625 Qualifiers::Const | Qualifiers::Volatile : Method->getTypeQualifiers(); 2626 QualType ImplicitParamType = Context.getCVRQualifiedType(ClassType, Quals); 2627 2628 // Set up the conversion sequence as a "bad" conversion, to allow us 2629 // to exit early. 2630 ImplicitConversionSequence ICS; 2631 2632 // We need to have an object of class type. 2633 QualType FromType = OrigFromType; 2634 if (const PointerType *PT = FromType->getAs<PointerType>()) 2635 FromType = PT->getPointeeType(); 2636 2637 assert(FromType->isRecordType()); 2638 2639 // The implicit object parameter is has the type "reference to cv X", 2640 // where X is the class of which the function is a member 2641 // (C++ [over.match.funcs]p4). However, when finding an implicit 2642 // conversion sequence for the argument, we are not allowed to 2643 // create temporaries or perform user-defined conversions 2644 // (C++ [over.match.funcs]p5). We perform a simplified version of 2645 // reference binding here, that allows class rvalues to bind to 2646 // non-constant references. 2647 2648 // First check the qualifiers. We don't care about lvalue-vs-rvalue 2649 // with the implicit object parameter (C++ [over.match.funcs]p5). 2650 QualType FromTypeCanon = Context.getCanonicalType(FromType); 2651 if (ImplicitParamType.getCVRQualifiers() 2652 != FromTypeCanon.getLocalCVRQualifiers() && 2653 !ImplicitParamType.isAtLeastAsQualifiedAs(FromTypeCanon)) { 2654 ICS.setBad(BadConversionSequence::bad_qualifiers, 2655 OrigFromType, ImplicitParamType); 2656 return ICS; 2657 } 2658 2659 // Check that we have either the same type or a derived type. It 2660 // affects the conversion rank. 2661 QualType ClassTypeCanon = Context.getCanonicalType(ClassType); 2662 ImplicitConversionKind SecondKind; 2663 if (ClassTypeCanon == FromTypeCanon.getLocalUnqualifiedType()) { 2664 SecondKind = ICK_Identity; 2665 } else if (IsDerivedFrom(FromType, ClassType)) 2666 SecondKind = ICK_Derived_To_Base; 2667 else { 2668 ICS.setBad(BadConversionSequence::unrelated_class, 2669 FromType, ImplicitParamType); 2670 return ICS; 2671 } 2672 2673 // Success. Mark this as a reference binding. 2674 ICS.setStandard(); 2675 ICS.Standard.setAsIdentityConversion(); 2676 ICS.Standard.Second = SecondKind; 2677 ICS.Standard.setFromType(FromType); 2678 ICS.Standard.setAllToTypes(ImplicitParamType); 2679 ICS.Standard.ReferenceBinding = true; 2680 ICS.Standard.DirectBinding = true; 2681 ICS.Standard.RRefBinding = false; 2682 return ICS; 2683} 2684 2685/// PerformObjectArgumentInitialization - Perform initialization of 2686/// the implicit object parameter for the given Method with the given 2687/// expression. 2688bool 2689Sema::PerformObjectArgumentInitialization(Expr *&From, 2690 NestedNameSpecifier *Qualifier, 2691 NamedDecl *FoundDecl, 2692 CXXMethodDecl *Method) { 2693 QualType FromRecordType, DestType; 2694 QualType ImplicitParamRecordType = 2695 Method->getThisType(Context)->getAs<PointerType>()->getPointeeType(); 2696 2697 if (const PointerType *PT = From->getType()->getAs<PointerType>()) { 2698 FromRecordType = PT->getPointeeType(); 2699 DestType = Method->getThisType(Context); 2700 } else { 2701 FromRecordType = From->getType(); 2702 DestType = ImplicitParamRecordType; 2703 } 2704 2705 // Note that we always use the true parent context when performing 2706 // the actual argument initialization. 2707 ImplicitConversionSequence ICS 2708 = TryObjectArgumentInitialization(From->getType(), Method, 2709 Method->getParent()); 2710 if (ICS.isBad()) 2711 return Diag(From->getSourceRange().getBegin(), 2712 diag::err_implicit_object_parameter_init) 2713 << ImplicitParamRecordType << FromRecordType << From->getSourceRange(); 2714 2715 if (ICS.Standard.Second == ICK_Derived_To_Base) 2716 return PerformObjectMemberConversion(From, Qualifier, FoundDecl, Method); 2717 2718 if (!Context.hasSameType(From->getType(), DestType)) 2719 ImpCastExprToType(From, DestType, CastExpr::CK_NoOp, 2720 /*isLvalue=*/!From->getType()->isPointerType()); 2721 return false; 2722} 2723 2724/// TryContextuallyConvertToBool - Attempt to contextually convert the 2725/// expression From to bool (C++0x [conv]p3). 2726ImplicitConversionSequence Sema::TryContextuallyConvertToBool(Expr *From) { 2727 return TryImplicitConversion(From, Context.BoolTy, 2728 // FIXME: Are these flags correct? 2729 /*SuppressUserConversions=*/false, 2730 /*AllowExplicit=*/true, 2731 /*InOverloadResolution=*/false); 2732} 2733 2734/// PerformContextuallyConvertToBool - Perform a contextual conversion 2735/// of the expression From to bool (C++0x [conv]p3). 2736bool Sema::PerformContextuallyConvertToBool(Expr *&From) { 2737 ImplicitConversionSequence ICS = TryContextuallyConvertToBool(From); 2738 if (!ICS.isBad()) 2739 return PerformImplicitConversion(From, Context.BoolTy, ICS, AA_Converting); 2740 2741 if (!DiagnoseMultipleUserDefinedConversion(From, Context.BoolTy)) 2742 return Diag(From->getSourceRange().getBegin(), 2743 diag::err_typecheck_bool_condition) 2744 << From->getType() << From->getSourceRange(); 2745 return true; 2746} 2747 2748/// AddOverloadCandidate - Adds the given function to the set of 2749/// candidate functions, using the given function call arguments. If 2750/// @p SuppressUserConversions, then don't allow user-defined 2751/// conversions via constructors or conversion operators. 2752/// 2753/// \para PartialOverloading true if we are performing "partial" overloading 2754/// based on an incomplete set of function arguments. This feature is used by 2755/// code completion. 2756void 2757Sema::AddOverloadCandidate(FunctionDecl *Function, 2758 DeclAccessPair FoundDecl, 2759 Expr **Args, unsigned NumArgs, 2760 OverloadCandidateSet& CandidateSet, 2761 bool SuppressUserConversions, 2762 bool PartialOverloading) { 2763 const FunctionProtoType* Proto 2764 = dyn_cast<FunctionProtoType>(Function->getType()->getAs<FunctionType>()); 2765 assert(Proto && "Functions without a prototype cannot be overloaded"); 2766 assert(!Function->getDescribedFunctionTemplate() && 2767 "Use AddTemplateOverloadCandidate for function templates"); 2768 2769 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Function)) { 2770 if (!isa<CXXConstructorDecl>(Method)) { 2771 // If we get here, it's because we're calling a member function 2772 // that is named without a member access expression (e.g., 2773 // "this->f") that was either written explicitly or created 2774 // implicitly. This can happen with a qualified call to a member 2775 // function, e.g., X::f(). We use an empty type for the implied 2776 // object argument (C++ [over.call.func]p3), and the acting context 2777 // is irrelevant. 2778 AddMethodCandidate(Method, FoundDecl, Method->getParent(), 2779 QualType(), Args, NumArgs, CandidateSet, 2780 SuppressUserConversions); 2781 return; 2782 } 2783 // We treat a constructor like a non-member function, since its object 2784 // argument doesn't participate in overload resolution. 2785 } 2786 2787 if (!CandidateSet.isNewCandidate(Function)) 2788 return; 2789 2790 // Overload resolution is always an unevaluated context. 2791 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 2792 2793 if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(Function)){ 2794 // C++ [class.copy]p3: 2795 // A member function template is never instantiated to perform the copy 2796 // of a class object to an object of its class type. 2797 QualType ClassType = Context.getTypeDeclType(Constructor->getParent()); 2798 if (NumArgs == 1 && 2799 Constructor->isCopyConstructorLikeSpecialization() && 2800 (Context.hasSameUnqualifiedType(ClassType, Args[0]->getType()) || 2801 IsDerivedFrom(Args[0]->getType(), ClassType))) 2802 return; 2803 } 2804 2805 // Add this candidate 2806 CandidateSet.push_back(OverloadCandidate()); 2807 OverloadCandidate& Candidate = CandidateSet.back(); 2808 Candidate.FoundDecl = FoundDecl; 2809 Candidate.Function = Function; 2810 Candidate.Viable = true; 2811 Candidate.IsSurrogate = false; 2812 Candidate.IgnoreObjectArgument = false; 2813 2814 unsigned NumArgsInProto = Proto->getNumArgs(); 2815 2816 // (C++ 13.3.2p2): A candidate function having fewer than m 2817 // parameters is viable only if it has an ellipsis in its parameter 2818 // list (8.3.5). 2819 if ((NumArgs + (PartialOverloading && NumArgs)) > NumArgsInProto && 2820 !Proto->isVariadic()) { 2821 Candidate.Viable = false; 2822 Candidate.FailureKind = ovl_fail_too_many_arguments; 2823 return; 2824 } 2825 2826 // (C++ 13.3.2p2): A candidate function having more than m parameters 2827 // is viable only if the (m+1)st parameter has a default argument 2828 // (8.3.6). For the purposes of overload resolution, the 2829 // parameter list is truncated on the right, so that there are 2830 // exactly m parameters. 2831 unsigned MinRequiredArgs = Function->getMinRequiredArguments(); 2832 if (NumArgs < MinRequiredArgs && !PartialOverloading) { 2833 // Not enough arguments. 2834 Candidate.Viable = false; 2835 Candidate.FailureKind = ovl_fail_too_few_arguments; 2836 return; 2837 } 2838 2839 // Determine the implicit conversion sequences for each of the 2840 // arguments. 2841 Candidate.Conversions.resize(NumArgs); 2842 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2843 if (ArgIdx < NumArgsInProto) { 2844 // (C++ 13.3.2p3): for F to be a viable function, there shall 2845 // exist for each argument an implicit conversion sequence 2846 // (13.3.3.1) that converts that argument to the corresponding 2847 // parameter of F. 2848 QualType ParamType = Proto->getArgType(ArgIdx); 2849 Candidate.Conversions[ArgIdx] 2850 = TryCopyInitialization(*this, Args[ArgIdx], ParamType, 2851 SuppressUserConversions, 2852 /*InOverloadResolution=*/true); 2853 if (Candidate.Conversions[ArgIdx].isBad()) { 2854 Candidate.Viable = false; 2855 Candidate.FailureKind = ovl_fail_bad_conversion; 2856 break; 2857 } 2858 } else { 2859 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2860 // argument for which there is no corresponding parameter is 2861 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2862 Candidate.Conversions[ArgIdx].setEllipsis(); 2863 } 2864 } 2865} 2866 2867/// \brief Add all of the function declarations in the given function set to 2868/// the overload canddiate set. 2869void Sema::AddFunctionCandidates(const UnresolvedSetImpl &Fns, 2870 Expr **Args, unsigned NumArgs, 2871 OverloadCandidateSet& CandidateSet, 2872 bool SuppressUserConversions) { 2873 for (UnresolvedSetIterator F = Fns.begin(), E = Fns.end(); F != E; ++F) { 2874 NamedDecl *D = F.getDecl()->getUnderlyingDecl(); 2875 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { 2876 if (isa<CXXMethodDecl>(FD) && !cast<CXXMethodDecl>(FD)->isStatic()) 2877 AddMethodCandidate(cast<CXXMethodDecl>(FD), F.getPair(), 2878 cast<CXXMethodDecl>(FD)->getParent(), 2879 Args[0]->getType(), Args + 1, NumArgs - 1, 2880 CandidateSet, SuppressUserConversions); 2881 else 2882 AddOverloadCandidate(FD, F.getPair(), Args, NumArgs, CandidateSet, 2883 SuppressUserConversions); 2884 } else { 2885 FunctionTemplateDecl *FunTmpl = cast<FunctionTemplateDecl>(D); 2886 if (isa<CXXMethodDecl>(FunTmpl->getTemplatedDecl()) && 2887 !cast<CXXMethodDecl>(FunTmpl->getTemplatedDecl())->isStatic()) 2888 AddMethodTemplateCandidate(FunTmpl, F.getPair(), 2889 cast<CXXRecordDecl>(FunTmpl->getDeclContext()), 2890 /*FIXME: explicit args */ 0, 2891 Args[0]->getType(), Args + 1, NumArgs - 1, 2892 CandidateSet, 2893 SuppressUserConversions); 2894 else 2895 AddTemplateOverloadCandidate(FunTmpl, F.getPair(), 2896 /*FIXME: explicit args */ 0, 2897 Args, NumArgs, CandidateSet, 2898 SuppressUserConversions); 2899 } 2900 } 2901} 2902 2903/// AddMethodCandidate - Adds a named decl (which is some kind of 2904/// method) as a method candidate to the given overload set. 2905void Sema::AddMethodCandidate(DeclAccessPair FoundDecl, 2906 QualType ObjectType, 2907 Expr **Args, unsigned NumArgs, 2908 OverloadCandidateSet& CandidateSet, 2909 bool SuppressUserConversions) { 2910 NamedDecl *Decl = FoundDecl.getDecl(); 2911 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(Decl->getDeclContext()); 2912 2913 if (isa<UsingShadowDecl>(Decl)) 2914 Decl = cast<UsingShadowDecl>(Decl)->getTargetDecl(); 2915 2916 if (FunctionTemplateDecl *TD = dyn_cast<FunctionTemplateDecl>(Decl)) { 2917 assert(isa<CXXMethodDecl>(TD->getTemplatedDecl()) && 2918 "Expected a member function template"); 2919 AddMethodTemplateCandidate(TD, FoundDecl, ActingContext, 2920 /*ExplicitArgs*/ 0, 2921 ObjectType, Args, NumArgs, 2922 CandidateSet, 2923 SuppressUserConversions); 2924 } else { 2925 AddMethodCandidate(cast<CXXMethodDecl>(Decl), FoundDecl, ActingContext, 2926 ObjectType, Args, NumArgs, 2927 CandidateSet, SuppressUserConversions); 2928 } 2929} 2930 2931/// AddMethodCandidate - Adds the given C++ member function to the set 2932/// of candidate functions, using the given function call arguments 2933/// and the object argument (@c Object). For example, in a call 2934/// @c o.f(a1,a2), @c Object will contain @c o and @c Args will contain 2935/// both @c a1 and @c a2. If @p SuppressUserConversions, then don't 2936/// allow user-defined conversions via constructors or conversion 2937/// operators. 2938void 2939Sema::AddMethodCandidate(CXXMethodDecl *Method, DeclAccessPair FoundDecl, 2940 CXXRecordDecl *ActingContext, QualType ObjectType, 2941 Expr **Args, unsigned NumArgs, 2942 OverloadCandidateSet& CandidateSet, 2943 bool SuppressUserConversions) { 2944 const FunctionProtoType* Proto 2945 = dyn_cast<FunctionProtoType>(Method->getType()->getAs<FunctionType>()); 2946 assert(Proto && "Methods without a prototype cannot be overloaded"); 2947 assert(!isa<CXXConstructorDecl>(Method) && 2948 "Use AddOverloadCandidate for constructors"); 2949 2950 if (!CandidateSet.isNewCandidate(Method)) 2951 return; 2952 2953 // Overload resolution is always an unevaluated context. 2954 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 2955 2956 // Add this candidate 2957 CandidateSet.push_back(OverloadCandidate()); 2958 OverloadCandidate& Candidate = CandidateSet.back(); 2959 Candidate.FoundDecl = FoundDecl; 2960 Candidate.Function = Method; 2961 Candidate.IsSurrogate = false; 2962 Candidate.IgnoreObjectArgument = false; 2963 2964 unsigned NumArgsInProto = Proto->getNumArgs(); 2965 2966 // (C++ 13.3.2p2): A candidate function having fewer than m 2967 // parameters is viable only if it has an ellipsis in its parameter 2968 // list (8.3.5). 2969 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 2970 Candidate.Viable = false; 2971 Candidate.FailureKind = ovl_fail_too_many_arguments; 2972 return; 2973 } 2974 2975 // (C++ 13.3.2p2): A candidate function having more than m parameters 2976 // is viable only if the (m+1)st parameter has a default argument 2977 // (8.3.6). For the purposes of overload resolution, the 2978 // parameter list is truncated on the right, so that there are 2979 // exactly m parameters. 2980 unsigned MinRequiredArgs = Method->getMinRequiredArguments(); 2981 if (NumArgs < MinRequiredArgs) { 2982 // Not enough arguments. 2983 Candidate.Viable = false; 2984 Candidate.FailureKind = ovl_fail_too_few_arguments; 2985 return; 2986 } 2987 2988 Candidate.Viable = true; 2989 Candidate.Conversions.resize(NumArgs + 1); 2990 2991 if (Method->isStatic() || ObjectType.isNull()) 2992 // The implicit object argument is ignored. 2993 Candidate.IgnoreObjectArgument = true; 2994 else { 2995 // Determine the implicit conversion sequence for the object 2996 // parameter. 2997 Candidate.Conversions[0] 2998 = TryObjectArgumentInitialization(ObjectType, Method, ActingContext); 2999 if (Candidate.Conversions[0].isBad()) { 3000 Candidate.Viable = false; 3001 Candidate.FailureKind = ovl_fail_bad_conversion; 3002 return; 3003 } 3004 } 3005 3006 // Determine the implicit conversion sequences for each of the 3007 // arguments. 3008 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 3009 if (ArgIdx < NumArgsInProto) { 3010 // (C++ 13.3.2p3): for F to be a viable function, there shall 3011 // exist for each argument an implicit conversion sequence 3012 // (13.3.3.1) that converts that argument to the corresponding 3013 // parameter of F. 3014 QualType ParamType = Proto->getArgType(ArgIdx); 3015 Candidate.Conversions[ArgIdx + 1] 3016 = TryCopyInitialization(*this, Args[ArgIdx], ParamType, 3017 SuppressUserConversions, 3018 /*InOverloadResolution=*/true); 3019 if (Candidate.Conversions[ArgIdx + 1].isBad()) { 3020 Candidate.Viable = false; 3021 Candidate.FailureKind = ovl_fail_bad_conversion; 3022 break; 3023 } 3024 } else { 3025 // (C++ 13.3.2p2): For the purposes of overload resolution, any 3026 // argument for which there is no corresponding parameter is 3027 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 3028 Candidate.Conversions[ArgIdx + 1].setEllipsis(); 3029 } 3030 } 3031} 3032 3033/// \brief Add a C++ member function template as a candidate to the candidate 3034/// set, using template argument deduction to produce an appropriate member 3035/// function template specialization. 3036void 3037Sema::AddMethodTemplateCandidate(FunctionTemplateDecl *MethodTmpl, 3038 DeclAccessPair FoundDecl, 3039 CXXRecordDecl *ActingContext, 3040 const TemplateArgumentListInfo *ExplicitTemplateArgs, 3041 QualType ObjectType, 3042 Expr **Args, unsigned NumArgs, 3043 OverloadCandidateSet& CandidateSet, 3044 bool SuppressUserConversions) { 3045 if (!CandidateSet.isNewCandidate(MethodTmpl)) 3046 return; 3047 3048 // C++ [over.match.funcs]p7: 3049 // In each case where a candidate is a function template, candidate 3050 // function template specializations are generated using template argument 3051 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 3052 // candidate functions in the usual way.113) A given name can refer to one 3053 // or more function templates and also to a set of overloaded non-template 3054 // functions. In such a case, the candidate functions generated from each 3055 // function template are combined with the set of non-template candidate 3056 // functions. 3057 TemplateDeductionInfo Info(Context, CandidateSet.getLocation()); 3058 FunctionDecl *Specialization = 0; 3059 if (TemplateDeductionResult Result 3060 = DeduceTemplateArguments(MethodTmpl, ExplicitTemplateArgs, 3061 Args, NumArgs, Specialization, Info)) { 3062 // FIXME: Record what happened with template argument deduction, so 3063 // that we can give the user a beautiful diagnostic. 3064 (void)Result; 3065 return; 3066 } 3067 3068 // Add the function template specialization produced by template argument 3069 // deduction as a candidate. 3070 assert(Specialization && "Missing member function template specialization?"); 3071 assert(isa<CXXMethodDecl>(Specialization) && 3072 "Specialization is not a member function?"); 3073 AddMethodCandidate(cast<CXXMethodDecl>(Specialization), FoundDecl, 3074 ActingContext, ObjectType, Args, NumArgs, 3075 CandidateSet, SuppressUserConversions); 3076} 3077 3078/// \brief Add a C++ function template specialization as a candidate 3079/// in the candidate set, using template argument deduction to produce 3080/// an appropriate function template specialization. 3081void 3082Sema::AddTemplateOverloadCandidate(FunctionTemplateDecl *FunctionTemplate, 3083 DeclAccessPair FoundDecl, 3084 const TemplateArgumentListInfo *ExplicitTemplateArgs, 3085 Expr **Args, unsigned NumArgs, 3086 OverloadCandidateSet& CandidateSet, 3087 bool SuppressUserConversions) { 3088 if (!CandidateSet.isNewCandidate(FunctionTemplate)) 3089 return; 3090 3091 // C++ [over.match.funcs]p7: 3092 // In each case where a candidate is a function template, candidate 3093 // function template specializations are generated using template argument 3094 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 3095 // candidate functions in the usual way.113) A given name can refer to one 3096 // or more function templates and also to a set of overloaded non-template 3097 // functions. In such a case, the candidate functions generated from each 3098 // function template are combined with the set of non-template candidate 3099 // functions. 3100 TemplateDeductionInfo Info(Context, CandidateSet.getLocation()); 3101 FunctionDecl *Specialization = 0; 3102 if (TemplateDeductionResult Result 3103 = DeduceTemplateArguments(FunctionTemplate, ExplicitTemplateArgs, 3104 Args, NumArgs, Specialization, Info)) { 3105 CandidateSet.push_back(OverloadCandidate()); 3106 OverloadCandidate &Candidate = CandidateSet.back(); 3107 Candidate.FoundDecl = FoundDecl; 3108 Candidate.Function = FunctionTemplate->getTemplatedDecl(); 3109 Candidate.Viable = false; 3110 Candidate.FailureKind = ovl_fail_bad_deduction; 3111 Candidate.IsSurrogate = false; 3112 Candidate.IgnoreObjectArgument = false; 3113 3114 // TODO: record more information about failed template arguments 3115 Candidate.DeductionFailure.Result = Result; 3116 Candidate.DeductionFailure.TemplateParameter = Info.Param.getOpaqueValue(); 3117 return; 3118 } 3119 3120 // Add the function template specialization produced by template argument 3121 // deduction as a candidate. 3122 assert(Specialization && "Missing function template specialization?"); 3123 AddOverloadCandidate(Specialization, FoundDecl, Args, NumArgs, CandidateSet, 3124 SuppressUserConversions); 3125} 3126 3127/// AddConversionCandidate - Add a C++ conversion function as a 3128/// candidate in the candidate set (C++ [over.match.conv], 3129/// C++ [over.match.copy]). From is the expression we're converting from, 3130/// and ToType is the type that we're eventually trying to convert to 3131/// (which may or may not be the same type as the type that the 3132/// conversion function produces). 3133void 3134Sema::AddConversionCandidate(CXXConversionDecl *Conversion, 3135 DeclAccessPair FoundDecl, 3136 CXXRecordDecl *ActingContext, 3137 Expr *From, QualType ToType, 3138 OverloadCandidateSet& CandidateSet) { 3139 assert(!Conversion->getDescribedFunctionTemplate() && 3140 "Conversion function templates use AddTemplateConversionCandidate"); 3141 QualType ConvType = Conversion->getConversionType().getNonReferenceType(); 3142 if (!CandidateSet.isNewCandidate(Conversion)) 3143 return; 3144 3145 // Overload resolution is always an unevaluated context. 3146 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 3147 3148 // Add this candidate 3149 CandidateSet.push_back(OverloadCandidate()); 3150 OverloadCandidate& Candidate = CandidateSet.back(); 3151 Candidate.FoundDecl = FoundDecl; 3152 Candidate.Function = Conversion; 3153 Candidate.IsSurrogate = false; 3154 Candidate.IgnoreObjectArgument = false; 3155 Candidate.FinalConversion.setAsIdentityConversion(); 3156 Candidate.FinalConversion.setFromType(ConvType); 3157 Candidate.FinalConversion.setAllToTypes(ToType); 3158 3159 // Determine the implicit conversion sequence for the implicit 3160 // object parameter. 3161 Candidate.Viable = true; 3162 Candidate.Conversions.resize(1); 3163 Candidate.Conversions[0] 3164 = TryObjectArgumentInitialization(From->getType(), Conversion, 3165 ActingContext); 3166 // Conversion functions to a different type in the base class is visible in 3167 // the derived class. So, a derived to base conversion should not participate 3168 // in overload resolution. 3169 if (Candidate.Conversions[0].Standard.Second == ICK_Derived_To_Base) 3170 Candidate.Conversions[0].Standard.Second = ICK_Identity; 3171 if (Candidate.Conversions[0].isBad()) { 3172 Candidate.Viable = false; 3173 Candidate.FailureKind = ovl_fail_bad_conversion; 3174 return; 3175 } 3176 3177 // We won't go through a user-define type conversion function to convert a 3178 // derived to base as such conversions are given Conversion Rank. They only 3179 // go through a copy constructor. 13.3.3.1.2-p4 [over.ics.user] 3180 QualType FromCanon 3181 = Context.getCanonicalType(From->getType().getUnqualifiedType()); 3182 QualType ToCanon = Context.getCanonicalType(ToType).getUnqualifiedType(); 3183 if (FromCanon == ToCanon || IsDerivedFrom(FromCanon, ToCanon)) { 3184 Candidate.Viable = false; 3185 Candidate.FailureKind = ovl_fail_trivial_conversion; 3186 return; 3187 } 3188 3189 // To determine what the conversion from the result of calling the 3190 // conversion function to the type we're eventually trying to 3191 // convert to (ToType), we need to synthesize a call to the 3192 // conversion function and attempt copy initialization from it. This 3193 // makes sure that we get the right semantics with respect to 3194 // lvalues/rvalues and the type. Fortunately, we can allocate this 3195 // call on the stack and we don't need its arguments to be 3196 // well-formed. 3197 DeclRefExpr ConversionRef(Conversion, Conversion->getType(), 3198 From->getLocStart()); 3199 ImplicitCastExpr ConversionFn(Context.getPointerType(Conversion->getType()), 3200 CastExpr::CK_FunctionToPointerDecay, 3201 &ConversionRef, CXXBaseSpecifierArray(), false); 3202 3203 // Note that it is safe to allocate CallExpr on the stack here because 3204 // there are 0 arguments (i.e., nothing is allocated using ASTContext's 3205 // allocator). 3206 CallExpr Call(Context, &ConversionFn, 0, 0, 3207 Conversion->getConversionType().getNonReferenceType(), 3208 From->getLocStart()); 3209 ImplicitConversionSequence ICS = 3210 TryCopyInitialization(*this, &Call, ToType, 3211 /*SuppressUserConversions=*/true, 3212 /*InOverloadResolution=*/false); 3213 3214 switch (ICS.getKind()) { 3215 case ImplicitConversionSequence::StandardConversion: 3216 Candidate.FinalConversion = ICS.Standard; 3217 3218 // C++ [over.ics.user]p3: 3219 // If the user-defined conversion is specified by a specialization of a 3220 // conversion function template, the second standard conversion sequence 3221 // shall have exact match rank. 3222 if (Conversion->getPrimaryTemplate() && 3223 GetConversionRank(ICS.Standard.Second) != ICR_Exact_Match) { 3224 Candidate.Viable = false; 3225 Candidate.FailureKind = ovl_fail_final_conversion_not_exact; 3226 } 3227 3228 break; 3229 3230 case ImplicitConversionSequence::BadConversion: 3231 Candidate.Viable = false; 3232 Candidate.FailureKind = ovl_fail_bad_final_conversion; 3233 break; 3234 3235 default: 3236 assert(false && 3237 "Can only end up with a standard conversion sequence or failure"); 3238 } 3239} 3240 3241/// \brief Adds a conversion function template specialization 3242/// candidate to the overload set, using template argument deduction 3243/// to deduce the template arguments of the conversion function 3244/// template from the type that we are converting to (C++ 3245/// [temp.deduct.conv]). 3246void 3247Sema::AddTemplateConversionCandidate(FunctionTemplateDecl *FunctionTemplate, 3248 DeclAccessPair FoundDecl, 3249 CXXRecordDecl *ActingDC, 3250 Expr *From, QualType ToType, 3251 OverloadCandidateSet &CandidateSet) { 3252 assert(isa<CXXConversionDecl>(FunctionTemplate->getTemplatedDecl()) && 3253 "Only conversion function templates permitted here"); 3254 3255 if (!CandidateSet.isNewCandidate(FunctionTemplate)) 3256 return; 3257 3258 TemplateDeductionInfo Info(Context, CandidateSet.getLocation()); 3259 CXXConversionDecl *Specialization = 0; 3260 if (TemplateDeductionResult Result 3261 = DeduceTemplateArguments(FunctionTemplate, ToType, 3262 Specialization, Info)) { 3263 // FIXME: Record what happened with template argument deduction, so 3264 // that we can give the user a beautiful diagnostic. 3265 (void)Result; 3266 return; 3267 } 3268 3269 // Add the conversion function template specialization produced by 3270 // template argument deduction as a candidate. 3271 assert(Specialization && "Missing function template specialization?"); 3272 AddConversionCandidate(Specialization, FoundDecl, ActingDC, From, ToType, 3273 CandidateSet); 3274} 3275 3276/// AddSurrogateCandidate - Adds a "surrogate" candidate function that 3277/// converts the given @c Object to a function pointer via the 3278/// conversion function @c Conversion, and then attempts to call it 3279/// with the given arguments (C++ [over.call.object]p2-4). Proto is 3280/// the type of function that we'll eventually be calling. 3281void Sema::AddSurrogateCandidate(CXXConversionDecl *Conversion, 3282 DeclAccessPair FoundDecl, 3283 CXXRecordDecl *ActingContext, 3284 const FunctionProtoType *Proto, 3285 QualType ObjectType, 3286 Expr **Args, unsigned NumArgs, 3287 OverloadCandidateSet& CandidateSet) { 3288 if (!CandidateSet.isNewCandidate(Conversion)) 3289 return; 3290 3291 // Overload resolution is always an unevaluated context. 3292 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 3293 3294 CandidateSet.push_back(OverloadCandidate()); 3295 OverloadCandidate& Candidate = CandidateSet.back(); 3296 Candidate.FoundDecl = FoundDecl; 3297 Candidate.Function = 0; 3298 Candidate.Surrogate = Conversion; 3299 Candidate.Viable = true; 3300 Candidate.IsSurrogate = true; 3301 Candidate.IgnoreObjectArgument = false; 3302 Candidate.Conversions.resize(NumArgs + 1); 3303 3304 // Determine the implicit conversion sequence for the implicit 3305 // object parameter. 3306 ImplicitConversionSequence ObjectInit 3307 = TryObjectArgumentInitialization(ObjectType, Conversion, ActingContext); 3308 if (ObjectInit.isBad()) { 3309 Candidate.Viable = false; 3310 Candidate.FailureKind = ovl_fail_bad_conversion; 3311 Candidate.Conversions[0] = ObjectInit; 3312 return; 3313 } 3314 3315 // The first conversion is actually a user-defined conversion whose 3316 // first conversion is ObjectInit's standard conversion (which is 3317 // effectively a reference binding). Record it as such. 3318 Candidate.Conversions[0].setUserDefined(); 3319 Candidate.Conversions[0].UserDefined.Before = ObjectInit.Standard; 3320 Candidate.Conversions[0].UserDefined.EllipsisConversion = false; 3321 Candidate.Conversions[0].UserDefined.ConversionFunction = Conversion; 3322 Candidate.Conversions[0].UserDefined.After 3323 = Candidate.Conversions[0].UserDefined.Before; 3324 Candidate.Conversions[0].UserDefined.After.setAsIdentityConversion(); 3325 3326 // Find the 3327 unsigned NumArgsInProto = Proto->getNumArgs(); 3328 3329 // (C++ 13.3.2p2): A candidate function having fewer than m 3330 // parameters is viable only if it has an ellipsis in its parameter 3331 // list (8.3.5). 3332 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 3333 Candidate.Viable = false; 3334 Candidate.FailureKind = ovl_fail_too_many_arguments; 3335 return; 3336 } 3337 3338 // Function types don't have any default arguments, so just check if 3339 // we have enough arguments. 3340 if (NumArgs < NumArgsInProto) { 3341 // Not enough arguments. 3342 Candidate.Viable = false; 3343 Candidate.FailureKind = ovl_fail_too_few_arguments; 3344 return; 3345 } 3346 3347 // Determine the implicit conversion sequences for each of the 3348 // arguments. 3349 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 3350 if (ArgIdx < NumArgsInProto) { 3351 // (C++ 13.3.2p3): for F to be a viable function, there shall 3352 // exist for each argument an implicit conversion sequence 3353 // (13.3.3.1) that converts that argument to the corresponding 3354 // parameter of F. 3355 QualType ParamType = Proto->getArgType(ArgIdx); 3356 Candidate.Conversions[ArgIdx + 1] 3357 = TryCopyInitialization(*this, Args[ArgIdx], ParamType, 3358 /*SuppressUserConversions=*/false, 3359 /*InOverloadResolution=*/false); 3360 if (Candidate.Conversions[ArgIdx + 1].isBad()) { 3361 Candidate.Viable = false; 3362 Candidate.FailureKind = ovl_fail_bad_conversion; 3363 break; 3364 } 3365 } else { 3366 // (C++ 13.3.2p2): For the purposes of overload resolution, any 3367 // argument for which there is no corresponding parameter is 3368 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 3369 Candidate.Conversions[ArgIdx + 1].setEllipsis(); 3370 } 3371 } 3372} 3373 3374/// \brief Add overload candidates for overloaded operators that are 3375/// member functions. 3376/// 3377/// Add the overloaded operator candidates that are member functions 3378/// for the operator Op that was used in an operator expression such 3379/// as "x Op y". , Args/NumArgs provides the operator arguments, and 3380/// CandidateSet will store the added overload candidates. (C++ 3381/// [over.match.oper]). 3382void Sema::AddMemberOperatorCandidates(OverloadedOperatorKind Op, 3383 SourceLocation OpLoc, 3384 Expr **Args, unsigned NumArgs, 3385 OverloadCandidateSet& CandidateSet, 3386 SourceRange OpRange) { 3387 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 3388 3389 // C++ [over.match.oper]p3: 3390 // For a unary operator @ with an operand of a type whose 3391 // cv-unqualified version is T1, and for a binary operator @ with 3392 // a left operand of a type whose cv-unqualified version is T1 and 3393 // a right operand of a type whose cv-unqualified version is T2, 3394 // three sets of candidate functions, designated member 3395 // candidates, non-member candidates and built-in candidates, are 3396 // constructed as follows: 3397 QualType T1 = Args[0]->getType(); 3398 QualType T2; 3399 if (NumArgs > 1) 3400 T2 = Args[1]->getType(); 3401 3402 // -- If T1 is a class type, the set of member candidates is the 3403 // result of the qualified lookup of T1::operator@ 3404 // (13.3.1.1.1); otherwise, the set of member candidates is 3405 // empty. 3406 if (const RecordType *T1Rec = T1->getAs<RecordType>()) { 3407 // Complete the type if it can be completed. Otherwise, we're done. 3408 if (RequireCompleteType(OpLoc, T1, PDiag())) 3409 return; 3410 3411 LookupResult Operators(*this, OpName, OpLoc, LookupOrdinaryName); 3412 LookupQualifiedName(Operators, T1Rec->getDecl()); 3413 Operators.suppressDiagnostics(); 3414 3415 for (LookupResult::iterator Oper = Operators.begin(), 3416 OperEnd = Operators.end(); 3417 Oper != OperEnd; 3418 ++Oper) 3419 AddMethodCandidate(Oper.getPair(), Args[0]->getType(), 3420 Args + 1, NumArgs - 1, CandidateSet, 3421 /* SuppressUserConversions = */ false); 3422 } 3423} 3424 3425/// AddBuiltinCandidate - Add a candidate for a built-in 3426/// operator. ResultTy and ParamTys are the result and parameter types 3427/// of the built-in candidate, respectively. Args and NumArgs are the 3428/// arguments being passed to the candidate. IsAssignmentOperator 3429/// should be true when this built-in candidate is an assignment 3430/// operator. NumContextualBoolArguments is the number of arguments 3431/// (at the beginning of the argument list) that will be contextually 3432/// converted to bool. 3433void Sema::AddBuiltinCandidate(QualType ResultTy, QualType *ParamTys, 3434 Expr **Args, unsigned NumArgs, 3435 OverloadCandidateSet& CandidateSet, 3436 bool IsAssignmentOperator, 3437 unsigned NumContextualBoolArguments) { 3438 // Overload resolution is always an unevaluated context. 3439 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 3440 3441 // Add this candidate 3442 CandidateSet.push_back(OverloadCandidate()); 3443 OverloadCandidate& Candidate = CandidateSet.back(); 3444 Candidate.FoundDecl = DeclAccessPair::make(0, AS_none); 3445 Candidate.Function = 0; 3446 Candidate.IsSurrogate = false; 3447 Candidate.IgnoreObjectArgument = false; 3448 Candidate.BuiltinTypes.ResultTy = ResultTy; 3449 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 3450 Candidate.BuiltinTypes.ParamTypes[ArgIdx] = ParamTys[ArgIdx]; 3451 3452 // Determine the implicit conversion sequences for each of the 3453 // arguments. 3454 Candidate.Viable = true; 3455 Candidate.Conversions.resize(NumArgs); 3456 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 3457 // C++ [over.match.oper]p4: 3458 // For the built-in assignment operators, conversions of the 3459 // left operand are restricted as follows: 3460 // -- no temporaries are introduced to hold the left operand, and 3461 // -- no user-defined conversions are applied to the left 3462 // operand to achieve a type match with the left-most 3463 // parameter of a built-in candidate. 3464 // 3465 // We block these conversions by turning off user-defined 3466 // conversions, since that is the only way that initialization of 3467 // a reference to a non-class type can occur from something that 3468 // is not of the same type. 3469 if (ArgIdx < NumContextualBoolArguments) { 3470 assert(ParamTys[ArgIdx] == Context.BoolTy && 3471 "Contextual conversion to bool requires bool type"); 3472 Candidate.Conversions[ArgIdx] = TryContextuallyConvertToBool(Args[ArgIdx]); 3473 } else { 3474 Candidate.Conversions[ArgIdx] 3475 = TryCopyInitialization(*this, Args[ArgIdx], ParamTys[ArgIdx], 3476 ArgIdx == 0 && IsAssignmentOperator, 3477 /*InOverloadResolution=*/false); 3478 } 3479 if (Candidate.Conversions[ArgIdx].isBad()) { 3480 Candidate.Viable = false; 3481 Candidate.FailureKind = ovl_fail_bad_conversion; 3482 break; 3483 } 3484 } 3485} 3486 3487/// BuiltinCandidateTypeSet - A set of types that will be used for the 3488/// candidate operator functions for built-in operators (C++ 3489/// [over.built]). The types are separated into pointer types and 3490/// enumeration types. 3491class BuiltinCandidateTypeSet { 3492 /// TypeSet - A set of types. 3493 typedef llvm::SmallPtrSet<QualType, 8> TypeSet; 3494 3495 /// PointerTypes - The set of pointer types that will be used in the 3496 /// built-in candidates. 3497 TypeSet PointerTypes; 3498 3499 /// MemberPointerTypes - The set of member pointer types that will be 3500 /// used in the built-in candidates. 3501 TypeSet MemberPointerTypes; 3502 3503 /// EnumerationTypes - The set of enumeration types that will be 3504 /// used in the built-in candidates. 3505 TypeSet EnumerationTypes; 3506 3507 /// Sema - The semantic analysis instance where we are building the 3508 /// candidate type set. 3509 Sema &SemaRef; 3510 3511 /// Context - The AST context in which we will build the type sets. 3512 ASTContext &Context; 3513 3514 bool AddPointerWithMoreQualifiedTypeVariants(QualType Ty, 3515 const Qualifiers &VisibleQuals); 3516 bool AddMemberPointerWithMoreQualifiedTypeVariants(QualType Ty); 3517 3518public: 3519 /// iterator - Iterates through the types that are part of the set. 3520 typedef TypeSet::iterator iterator; 3521 3522 BuiltinCandidateTypeSet(Sema &SemaRef) 3523 : SemaRef(SemaRef), Context(SemaRef.Context) { } 3524 3525 void AddTypesConvertedFrom(QualType Ty, 3526 SourceLocation Loc, 3527 bool AllowUserConversions, 3528 bool AllowExplicitConversions, 3529 const Qualifiers &VisibleTypeConversionsQuals); 3530 3531 /// pointer_begin - First pointer type found; 3532 iterator pointer_begin() { return PointerTypes.begin(); } 3533 3534 /// pointer_end - Past the last pointer type found; 3535 iterator pointer_end() { return PointerTypes.end(); } 3536 3537 /// member_pointer_begin - First member pointer type found; 3538 iterator member_pointer_begin() { return MemberPointerTypes.begin(); } 3539 3540 /// member_pointer_end - Past the last member pointer type found; 3541 iterator member_pointer_end() { return MemberPointerTypes.end(); } 3542 3543 /// enumeration_begin - First enumeration type found; 3544 iterator enumeration_begin() { return EnumerationTypes.begin(); } 3545 3546 /// enumeration_end - Past the last enumeration type found; 3547 iterator enumeration_end() { return EnumerationTypes.end(); } 3548}; 3549 3550/// AddPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty to 3551/// the set of pointer types along with any more-qualified variants of 3552/// that type. For example, if @p Ty is "int const *", this routine 3553/// will add "int const *", "int const volatile *", "int const 3554/// restrict *", and "int const volatile restrict *" to the set of 3555/// pointer types. Returns true if the add of @p Ty itself succeeded, 3556/// false otherwise. 3557/// 3558/// FIXME: what to do about extended qualifiers? 3559bool 3560BuiltinCandidateTypeSet::AddPointerWithMoreQualifiedTypeVariants(QualType Ty, 3561 const Qualifiers &VisibleQuals) { 3562 3563 // Insert this type. 3564 if (!PointerTypes.insert(Ty)) 3565 return false; 3566 3567 const PointerType *PointerTy = Ty->getAs<PointerType>(); 3568 assert(PointerTy && "type was not a pointer type!"); 3569 3570 QualType PointeeTy = PointerTy->getPointeeType(); 3571 // Don't add qualified variants of arrays. For one, they're not allowed 3572 // (the qualifier would sink to the element type), and for another, the 3573 // only overload situation where it matters is subscript or pointer +- int, 3574 // and those shouldn't have qualifier variants anyway. 3575 if (PointeeTy->isArrayType()) 3576 return true; 3577 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 3578 if (const ConstantArrayType *Array =Context.getAsConstantArrayType(PointeeTy)) 3579 BaseCVR = Array->getElementType().getCVRQualifiers(); 3580 bool hasVolatile = VisibleQuals.hasVolatile(); 3581 bool hasRestrict = VisibleQuals.hasRestrict(); 3582 3583 // Iterate through all strict supersets of BaseCVR. 3584 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 3585 if ((CVR | BaseCVR) != CVR) continue; 3586 // Skip over Volatile/Restrict if no Volatile/Restrict found anywhere 3587 // in the types. 3588 if ((CVR & Qualifiers::Volatile) && !hasVolatile) continue; 3589 if ((CVR & Qualifiers::Restrict) && !hasRestrict) continue; 3590 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 3591 PointerTypes.insert(Context.getPointerType(QPointeeTy)); 3592 } 3593 3594 return true; 3595} 3596 3597/// AddMemberPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty 3598/// to the set of pointer types along with any more-qualified variants of 3599/// that type. For example, if @p Ty is "int const *", this routine 3600/// will add "int const *", "int const volatile *", "int const 3601/// restrict *", and "int const volatile restrict *" to the set of 3602/// pointer types. Returns true if the add of @p Ty itself succeeded, 3603/// false otherwise. 3604/// 3605/// FIXME: what to do about extended qualifiers? 3606bool 3607BuiltinCandidateTypeSet::AddMemberPointerWithMoreQualifiedTypeVariants( 3608 QualType Ty) { 3609 // Insert this type. 3610 if (!MemberPointerTypes.insert(Ty)) 3611 return false; 3612 3613 const MemberPointerType *PointerTy = Ty->getAs<MemberPointerType>(); 3614 assert(PointerTy && "type was not a member pointer type!"); 3615 3616 QualType PointeeTy = PointerTy->getPointeeType(); 3617 // Don't add qualified variants of arrays. For one, they're not allowed 3618 // (the qualifier would sink to the element type), and for another, the 3619 // only overload situation where it matters is subscript or pointer +- int, 3620 // and those shouldn't have qualifier variants anyway. 3621 if (PointeeTy->isArrayType()) 3622 return true; 3623 const Type *ClassTy = PointerTy->getClass(); 3624 3625 // Iterate through all strict supersets of the pointee type's CVR 3626 // qualifiers. 3627 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 3628 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 3629 if ((CVR | BaseCVR) != CVR) continue; 3630 3631 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 3632 MemberPointerTypes.insert(Context.getMemberPointerType(QPointeeTy, ClassTy)); 3633 } 3634 3635 return true; 3636} 3637 3638/// AddTypesConvertedFrom - Add each of the types to which the type @p 3639/// Ty can be implicit converted to the given set of @p Types. We're 3640/// primarily interested in pointer types and enumeration types. We also 3641/// take member pointer types, for the conditional operator. 3642/// AllowUserConversions is true if we should look at the conversion 3643/// functions of a class type, and AllowExplicitConversions if we 3644/// should also include the explicit conversion functions of a class 3645/// type. 3646void 3647BuiltinCandidateTypeSet::AddTypesConvertedFrom(QualType Ty, 3648 SourceLocation Loc, 3649 bool AllowUserConversions, 3650 bool AllowExplicitConversions, 3651 const Qualifiers &VisibleQuals) { 3652 // Only deal with canonical types. 3653 Ty = Context.getCanonicalType(Ty); 3654 3655 // Look through reference types; they aren't part of the type of an 3656 // expression for the purposes of conversions. 3657 if (const ReferenceType *RefTy = Ty->getAs<ReferenceType>()) 3658 Ty = RefTy->getPointeeType(); 3659 3660 // We don't care about qualifiers on the type. 3661 Ty = Ty.getLocalUnqualifiedType(); 3662 3663 // If we're dealing with an array type, decay to the pointer. 3664 if (Ty->isArrayType()) 3665 Ty = SemaRef.Context.getArrayDecayedType(Ty); 3666 3667 if (const PointerType *PointerTy = Ty->getAs<PointerType>()) { 3668 QualType PointeeTy = PointerTy->getPointeeType(); 3669 3670 // Insert our type, and its more-qualified variants, into the set 3671 // of types. 3672 if (!AddPointerWithMoreQualifiedTypeVariants(Ty, VisibleQuals)) 3673 return; 3674 } else if (Ty->isMemberPointerType()) { 3675 // Member pointers are far easier, since the pointee can't be converted. 3676 if (!AddMemberPointerWithMoreQualifiedTypeVariants(Ty)) 3677 return; 3678 } else if (Ty->isEnumeralType()) { 3679 EnumerationTypes.insert(Ty); 3680 } else if (AllowUserConversions) { 3681 if (const RecordType *TyRec = Ty->getAs<RecordType>()) { 3682 if (SemaRef.RequireCompleteType(Loc, Ty, 0)) { 3683 // No conversion functions in incomplete types. 3684 return; 3685 } 3686 3687 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 3688 const UnresolvedSetImpl *Conversions 3689 = ClassDecl->getVisibleConversionFunctions(); 3690 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 3691 E = Conversions->end(); I != E; ++I) { 3692 NamedDecl *D = I.getDecl(); 3693 if (isa<UsingShadowDecl>(D)) 3694 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 3695 3696 // Skip conversion function templates; they don't tell us anything 3697 // about which builtin types we can convert to. 3698 if (isa<FunctionTemplateDecl>(D)) 3699 continue; 3700 3701 CXXConversionDecl *Conv = cast<CXXConversionDecl>(D); 3702 if (AllowExplicitConversions || !Conv->isExplicit()) { 3703 AddTypesConvertedFrom(Conv->getConversionType(), Loc, false, false, 3704 VisibleQuals); 3705 } 3706 } 3707 } 3708 } 3709} 3710 3711/// \brief Helper function for AddBuiltinOperatorCandidates() that adds 3712/// the volatile- and non-volatile-qualified assignment operators for the 3713/// given type to the candidate set. 3714static void AddBuiltinAssignmentOperatorCandidates(Sema &S, 3715 QualType T, 3716 Expr **Args, 3717 unsigned NumArgs, 3718 OverloadCandidateSet &CandidateSet) { 3719 QualType ParamTypes[2]; 3720 3721 // T& operator=(T&, T) 3722 ParamTypes[0] = S.Context.getLValueReferenceType(T); 3723 ParamTypes[1] = T; 3724 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3725 /*IsAssignmentOperator=*/true); 3726 3727 if (!S.Context.getCanonicalType(T).isVolatileQualified()) { 3728 // volatile T& operator=(volatile T&, T) 3729 ParamTypes[0] 3730 = S.Context.getLValueReferenceType(S.Context.getVolatileType(T)); 3731 ParamTypes[1] = T; 3732 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3733 /*IsAssignmentOperator=*/true); 3734 } 3735} 3736 3737/// CollectVRQualifiers - This routine returns Volatile/Restrict qualifiers, 3738/// if any, found in visible type conversion functions found in ArgExpr's type. 3739static Qualifiers CollectVRQualifiers(ASTContext &Context, Expr* ArgExpr) { 3740 Qualifiers VRQuals; 3741 const RecordType *TyRec; 3742 if (const MemberPointerType *RHSMPType = 3743 ArgExpr->getType()->getAs<MemberPointerType>()) 3744 TyRec = RHSMPType->getClass()->getAs<RecordType>(); 3745 else 3746 TyRec = ArgExpr->getType()->getAs<RecordType>(); 3747 if (!TyRec) { 3748 // Just to be safe, assume the worst case. 3749 VRQuals.addVolatile(); 3750 VRQuals.addRestrict(); 3751 return VRQuals; 3752 } 3753 3754 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 3755 if (!ClassDecl->hasDefinition()) 3756 return VRQuals; 3757 3758 const UnresolvedSetImpl *Conversions = 3759 ClassDecl->getVisibleConversionFunctions(); 3760 3761 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 3762 E = Conversions->end(); I != E; ++I) { 3763 NamedDecl *D = I.getDecl(); 3764 if (isa<UsingShadowDecl>(D)) 3765 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 3766 if (CXXConversionDecl *Conv = dyn_cast<CXXConversionDecl>(D)) { 3767 QualType CanTy = Context.getCanonicalType(Conv->getConversionType()); 3768 if (const ReferenceType *ResTypeRef = CanTy->getAs<ReferenceType>()) 3769 CanTy = ResTypeRef->getPointeeType(); 3770 // Need to go down the pointer/mempointer chain and add qualifiers 3771 // as see them. 3772 bool done = false; 3773 while (!done) { 3774 if (const PointerType *ResTypePtr = CanTy->getAs<PointerType>()) 3775 CanTy = ResTypePtr->getPointeeType(); 3776 else if (const MemberPointerType *ResTypeMPtr = 3777 CanTy->getAs<MemberPointerType>()) 3778 CanTy = ResTypeMPtr->getPointeeType(); 3779 else 3780 done = true; 3781 if (CanTy.isVolatileQualified()) 3782 VRQuals.addVolatile(); 3783 if (CanTy.isRestrictQualified()) 3784 VRQuals.addRestrict(); 3785 if (VRQuals.hasRestrict() && VRQuals.hasVolatile()) 3786 return VRQuals; 3787 } 3788 } 3789 } 3790 return VRQuals; 3791} 3792 3793/// AddBuiltinOperatorCandidates - Add the appropriate built-in 3794/// operator overloads to the candidate set (C++ [over.built]), based 3795/// on the operator @p Op and the arguments given. For example, if the 3796/// operator is a binary '+', this routine might add "int 3797/// operator+(int, int)" to cover integer addition. 3798void 3799Sema::AddBuiltinOperatorCandidates(OverloadedOperatorKind Op, 3800 SourceLocation OpLoc, 3801 Expr **Args, unsigned NumArgs, 3802 OverloadCandidateSet& CandidateSet) { 3803 // The set of "promoted arithmetic types", which are the arithmetic 3804 // types are that preserved by promotion (C++ [over.built]p2). Note 3805 // that the first few of these types are the promoted integral 3806 // types; these types need to be first. 3807 // FIXME: What about complex? 3808 const unsigned FirstIntegralType = 0; 3809 const unsigned LastIntegralType = 13; 3810 const unsigned FirstPromotedIntegralType = 7, 3811 LastPromotedIntegralType = 13; 3812 const unsigned FirstPromotedArithmeticType = 7, 3813 LastPromotedArithmeticType = 16; 3814 const unsigned NumArithmeticTypes = 16; 3815 QualType ArithmeticTypes[NumArithmeticTypes] = { 3816 Context.BoolTy, Context.CharTy, Context.WCharTy, 3817// FIXME: Context.Char16Ty, Context.Char32Ty, 3818 Context.SignedCharTy, Context.ShortTy, 3819 Context.UnsignedCharTy, Context.UnsignedShortTy, 3820 Context.IntTy, Context.LongTy, Context.LongLongTy, 3821 Context.UnsignedIntTy, Context.UnsignedLongTy, Context.UnsignedLongLongTy, 3822 Context.FloatTy, Context.DoubleTy, Context.LongDoubleTy 3823 }; 3824 assert(ArithmeticTypes[FirstPromotedIntegralType] == Context.IntTy && 3825 "Invalid first promoted integral type"); 3826 assert(ArithmeticTypes[LastPromotedIntegralType - 1] 3827 == Context.UnsignedLongLongTy && 3828 "Invalid last promoted integral type"); 3829 assert(ArithmeticTypes[FirstPromotedArithmeticType] == Context.IntTy && 3830 "Invalid first promoted arithmetic type"); 3831 assert(ArithmeticTypes[LastPromotedArithmeticType - 1] 3832 == Context.LongDoubleTy && 3833 "Invalid last promoted arithmetic type"); 3834 3835 // Find all of the types that the arguments can convert to, but only 3836 // if the operator we're looking at has built-in operator candidates 3837 // that make use of these types. 3838 Qualifiers VisibleTypeConversionsQuals; 3839 VisibleTypeConversionsQuals.addConst(); 3840 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 3841 VisibleTypeConversionsQuals += CollectVRQualifiers(Context, Args[ArgIdx]); 3842 3843 BuiltinCandidateTypeSet CandidateTypes(*this); 3844 if (Op == OO_Less || Op == OO_Greater || Op == OO_LessEqual || 3845 Op == OO_GreaterEqual || Op == OO_EqualEqual || Op == OO_ExclaimEqual || 3846 Op == OO_Plus || (Op == OO_Minus && NumArgs == 2) || Op == OO_Equal || 3847 Op == OO_PlusEqual || Op == OO_MinusEqual || Op == OO_Subscript || 3848 Op == OO_ArrowStar || Op == OO_PlusPlus || Op == OO_MinusMinus || 3849 (Op == OO_Star && NumArgs == 1) || Op == OO_Conditional) { 3850 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 3851 CandidateTypes.AddTypesConvertedFrom(Args[ArgIdx]->getType(), 3852 OpLoc, 3853 true, 3854 (Op == OO_Exclaim || 3855 Op == OO_AmpAmp || 3856 Op == OO_PipePipe), 3857 VisibleTypeConversionsQuals); 3858 } 3859 3860 bool isComparison = false; 3861 switch (Op) { 3862 case OO_None: 3863 case NUM_OVERLOADED_OPERATORS: 3864 assert(false && "Expected an overloaded operator"); 3865 break; 3866 3867 case OO_Star: // '*' is either unary or binary 3868 if (NumArgs == 1) 3869 goto UnaryStar; 3870 else 3871 goto BinaryStar; 3872 break; 3873 3874 case OO_Plus: // '+' is either unary or binary 3875 if (NumArgs == 1) 3876 goto UnaryPlus; 3877 else 3878 goto BinaryPlus; 3879 break; 3880 3881 case OO_Minus: // '-' is either unary or binary 3882 if (NumArgs == 1) 3883 goto UnaryMinus; 3884 else 3885 goto BinaryMinus; 3886 break; 3887 3888 case OO_Amp: // '&' is either unary or binary 3889 if (NumArgs == 1) 3890 goto UnaryAmp; 3891 else 3892 goto BinaryAmp; 3893 3894 case OO_PlusPlus: 3895 case OO_MinusMinus: 3896 // C++ [over.built]p3: 3897 // 3898 // For every pair (T, VQ), where T is an arithmetic type, and VQ 3899 // is either volatile or empty, there exist candidate operator 3900 // functions of the form 3901 // 3902 // VQ T& operator++(VQ T&); 3903 // T operator++(VQ T&, int); 3904 // 3905 // C++ [over.built]p4: 3906 // 3907 // For every pair (T, VQ), where T is an arithmetic type other 3908 // than bool, and VQ is either volatile or empty, there exist 3909 // candidate operator functions of the form 3910 // 3911 // VQ T& operator--(VQ T&); 3912 // T operator--(VQ T&, int); 3913 for (unsigned Arith = (Op == OO_PlusPlus? 0 : 1); 3914 Arith < NumArithmeticTypes; ++Arith) { 3915 QualType ArithTy = ArithmeticTypes[Arith]; 3916 QualType ParamTypes[2] 3917 = { Context.getLValueReferenceType(ArithTy), Context.IntTy }; 3918 3919 // Non-volatile version. 3920 if (NumArgs == 1) 3921 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3922 else 3923 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 3924 // heuristic to reduce number of builtin candidates in the set. 3925 // Add volatile version only if there are conversions to a volatile type. 3926 if (VisibleTypeConversionsQuals.hasVolatile()) { 3927 // Volatile version 3928 ParamTypes[0] 3929 = Context.getLValueReferenceType(Context.getVolatileType(ArithTy)); 3930 if (NumArgs == 1) 3931 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3932 else 3933 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 3934 } 3935 } 3936 3937 // C++ [over.built]p5: 3938 // 3939 // For every pair (T, VQ), where T is a cv-qualified or 3940 // cv-unqualified object type, and VQ is either volatile or 3941 // empty, there exist candidate operator functions of the form 3942 // 3943 // T*VQ& operator++(T*VQ&); 3944 // T*VQ& operator--(T*VQ&); 3945 // T* operator++(T*VQ&, int); 3946 // T* operator--(T*VQ&, int); 3947 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3948 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3949 // Skip pointer types that aren't pointers to object types. 3950 if (!(*Ptr)->getAs<PointerType>()->getPointeeType()->isObjectType()) 3951 continue; 3952 3953 QualType ParamTypes[2] = { 3954 Context.getLValueReferenceType(*Ptr), Context.IntTy 3955 }; 3956 3957 // Without volatile 3958 if (NumArgs == 1) 3959 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3960 else 3961 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3962 3963 if (!Context.getCanonicalType(*Ptr).isVolatileQualified() && 3964 VisibleTypeConversionsQuals.hasVolatile()) { 3965 // With volatile 3966 ParamTypes[0] 3967 = Context.getLValueReferenceType(Context.getVolatileType(*Ptr)); 3968 if (NumArgs == 1) 3969 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3970 else 3971 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3972 } 3973 } 3974 break; 3975 3976 UnaryStar: 3977 // C++ [over.built]p6: 3978 // For every cv-qualified or cv-unqualified object type T, there 3979 // exist candidate operator functions of the form 3980 // 3981 // T& operator*(T*); 3982 // 3983 // C++ [over.built]p7: 3984 // For every function type T, there exist candidate operator 3985 // functions of the form 3986 // T& operator*(T*); 3987 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3988 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3989 QualType ParamTy = *Ptr; 3990 QualType PointeeTy = ParamTy->getAs<PointerType>()->getPointeeType(); 3991 AddBuiltinCandidate(Context.getLValueReferenceType(PointeeTy), 3992 &ParamTy, Args, 1, CandidateSet); 3993 } 3994 break; 3995 3996 UnaryPlus: 3997 // C++ [over.built]p8: 3998 // For every type T, there exist candidate operator functions of 3999 // the form 4000 // 4001 // T* operator+(T*); 4002 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 4003 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4004 QualType ParamTy = *Ptr; 4005 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet); 4006 } 4007 4008 // Fall through 4009 4010 UnaryMinus: 4011 // C++ [over.built]p9: 4012 // For every promoted arithmetic type T, there exist candidate 4013 // operator functions of the form 4014 // 4015 // T operator+(T); 4016 // T operator-(T); 4017 for (unsigned Arith = FirstPromotedArithmeticType; 4018 Arith < LastPromotedArithmeticType; ++Arith) { 4019 QualType ArithTy = ArithmeticTypes[Arith]; 4020 AddBuiltinCandidate(ArithTy, &ArithTy, Args, 1, CandidateSet); 4021 } 4022 break; 4023 4024 case OO_Tilde: 4025 // C++ [over.built]p10: 4026 // For every promoted integral type T, there exist candidate 4027 // operator functions of the form 4028 // 4029 // T operator~(T); 4030 for (unsigned Int = FirstPromotedIntegralType; 4031 Int < LastPromotedIntegralType; ++Int) { 4032 QualType IntTy = ArithmeticTypes[Int]; 4033 AddBuiltinCandidate(IntTy, &IntTy, Args, 1, CandidateSet); 4034 } 4035 break; 4036 4037 case OO_New: 4038 case OO_Delete: 4039 case OO_Array_New: 4040 case OO_Array_Delete: 4041 case OO_Call: 4042 assert(false && "Special operators don't use AddBuiltinOperatorCandidates"); 4043 break; 4044 4045 case OO_Comma: 4046 UnaryAmp: 4047 case OO_Arrow: 4048 // C++ [over.match.oper]p3: 4049 // -- For the operator ',', the unary operator '&', or the 4050 // operator '->', the built-in candidates set is empty. 4051 break; 4052 4053 case OO_EqualEqual: 4054 case OO_ExclaimEqual: 4055 // C++ [over.match.oper]p16: 4056 // For every pointer to member type T, there exist candidate operator 4057 // functions of the form 4058 // 4059 // bool operator==(T,T); 4060 // bool operator!=(T,T); 4061 for (BuiltinCandidateTypeSet::iterator 4062 MemPtr = CandidateTypes.member_pointer_begin(), 4063 MemPtrEnd = CandidateTypes.member_pointer_end(); 4064 MemPtr != MemPtrEnd; 4065 ++MemPtr) { 4066 QualType ParamTypes[2] = { *MemPtr, *MemPtr }; 4067 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 4068 } 4069 4070 // Fall through 4071 4072 case OO_Less: 4073 case OO_Greater: 4074 case OO_LessEqual: 4075 case OO_GreaterEqual: 4076 // C++ [over.built]p15: 4077 // 4078 // For every pointer or enumeration type T, there exist 4079 // candidate operator functions of the form 4080 // 4081 // bool operator<(T, T); 4082 // bool operator>(T, T); 4083 // bool operator<=(T, T); 4084 // bool operator>=(T, T); 4085 // bool operator==(T, T); 4086 // bool operator!=(T, T); 4087 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 4088 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4089 QualType ParamTypes[2] = { *Ptr, *Ptr }; 4090 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 4091 } 4092 for (BuiltinCandidateTypeSet::iterator Enum 4093 = CandidateTypes.enumeration_begin(); 4094 Enum != CandidateTypes.enumeration_end(); ++Enum) { 4095 QualType ParamTypes[2] = { *Enum, *Enum }; 4096 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 4097 } 4098 4099 // Fall through. 4100 isComparison = true; 4101 4102 BinaryPlus: 4103 BinaryMinus: 4104 if (!isComparison) { 4105 // We didn't fall through, so we must have OO_Plus or OO_Minus. 4106 4107 // C++ [over.built]p13: 4108 // 4109 // For every cv-qualified or cv-unqualified object type T 4110 // there exist candidate operator functions of the form 4111 // 4112 // T* operator+(T*, ptrdiff_t); 4113 // T& operator[](T*, ptrdiff_t); [BELOW] 4114 // T* operator-(T*, ptrdiff_t); 4115 // T* operator+(ptrdiff_t, T*); 4116 // T& operator[](ptrdiff_t, T*); [BELOW] 4117 // 4118 // C++ [over.built]p14: 4119 // 4120 // For every T, where T is a pointer to object type, there 4121 // exist candidate operator functions of the form 4122 // 4123 // ptrdiff_t operator-(T, T); 4124 for (BuiltinCandidateTypeSet::iterator Ptr 4125 = CandidateTypes.pointer_begin(); 4126 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4127 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 4128 4129 // operator+(T*, ptrdiff_t) or operator-(T*, ptrdiff_t) 4130 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 4131 4132 if (Op == OO_Plus) { 4133 // T* operator+(ptrdiff_t, T*); 4134 ParamTypes[0] = ParamTypes[1]; 4135 ParamTypes[1] = *Ptr; 4136 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 4137 } else { 4138 // ptrdiff_t operator-(T, T); 4139 ParamTypes[1] = *Ptr; 4140 AddBuiltinCandidate(Context.getPointerDiffType(), ParamTypes, 4141 Args, 2, CandidateSet); 4142 } 4143 } 4144 } 4145 // Fall through 4146 4147 case OO_Slash: 4148 BinaryStar: 4149 Conditional: 4150 // C++ [over.built]p12: 4151 // 4152 // For every pair of promoted arithmetic types L and R, there 4153 // exist candidate operator functions of the form 4154 // 4155 // LR operator*(L, R); 4156 // LR operator/(L, R); 4157 // LR operator+(L, R); 4158 // LR operator-(L, R); 4159 // bool operator<(L, R); 4160 // bool operator>(L, R); 4161 // bool operator<=(L, R); 4162 // bool operator>=(L, R); 4163 // bool operator==(L, R); 4164 // bool operator!=(L, R); 4165 // 4166 // where LR is the result of the usual arithmetic conversions 4167 // between types L and R. 4168 // 4169 // C++ [over.built]p24: 4170 // 4171 // For every pair of promoted arithmetic types L and R, there exist 4172 // candidate operator functions of the form 4173 // 4174 // LR operator?(bool, L, R); 4175 // 4176 // where LR is the result of the usual arithmetic conversions 4177 // between types L and R. 4178 // Our candidates ignore the first parameter. 4179 for (unsigned Left = FirstPromotedArithmeticType; 4180 Left < LastPromotedArithmeticType; ++Left) { 4181 for (unsigned Right = FirstPromotedArithmeticType; 4182 Right < LastPromotedArithmeticType; ++Right) { 4183 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 4184 QualType Result 4185 = isComparison 4186 ? Context.BoolTy 4187 : Context.UsualArithmeticConversionsType(LandR[0], LandR[1]); 4188 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 4189 } 4190 } 4191 break; 4192 4193 case OO_Percent: 4194 BinaryAmp: 4195 case OO_Caret: 4196 case OO_Pipe: 4197 case OO_LessLess: 4198 case OO_GreaterGreater: 4199 // C++ [over.built]p17: 4200 // 4201 // For every pair of promoted integral types L and R, there 4202 // exist candidate operator functions of the form 4203 // 4204 // LR operator%(L, R); 4205 // LR operator&(L, R); 4206 // LR operator^(L, R); 4207 // LR operator|(L, R); 4208 // L operator<<(L, R); 4209 // L operator>>(L, R); 4210 // 4211 // where LR is the result of the usual arithmetic conversions 4212 // between types L and R. 4213 for (unsigned Left = FirstPromotedIntegralType; 4214 Left < LastPromotedIntegralType; ++Left) { 4215 for (unsigned Right = FirstPromotedIntegralType; 4216 Right < LastPromotedIntegralType; ++Right) { 4217 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 4218 QualType Result = (Op == OO_LessLess || Op == OO_GreaterGreater) 4219 ? LandR[0] 4220 : Context.UsualArithmeticConversionsType(LandR[0], LandR[1]); 4221 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 4222 } 4223 } 4224 break; 4225 4226 case OO_Equal: 4227 // C++ [over.built]p20: 4228 // 4229 // For every pair (T, VQ), where T is an enumeration or 4230 // pointer to member type and VQ is either volatile or 4231 // empty, there exist candidate operator functions of the form 4232 // 4233 // VQ T& operator=(VQ T&, T); 4234 for (BuiltinCandidateTypeSet::iterator 4235 Enum = CandidateTypes.enumeration_begin(), 4236 EnumEnd = CandidateTypes.enumeration_end(); 4237 Enum != EnumEnd; ++Enum) 4238 AddBuiltinAssignmentOperatorCandidates(*this, *Enum, Args, 2, 4239 CandidateSet); 4240 for (BuiltinCandidateTypeSet::iterator 4241 MemPtr = CandidateTypes.member_pointer_begin(), 4242 MemPtrEnd = CandidateTypes.member_pointer_end(); 4243 MemPtr != MemPtrEnd; ++MemPtr) 4244 AddBuiltinAssignmentOperatorCandidates(*this, *MemPtr, Args, 2, 4245 CandidateSet); 4246 // Fall through. 4247 4248 case OO_PlusEqual: 4249 case OO_MinusEqual: 4250 // C++ [over.built]p19: 4251 // 4252 // For every pair (T, VQ), where T is any type and VQ is either 4253 // volatile or empty, there exist candidate operator functions 4254 // of the form 4255 // 4256 // T*VQ& operator=(T*VQ&, T*); 4257 // 4258 // C++ [over.built]p21: 4259 // 4260 // For every pair (T, VQ), where T is a cv-qualified or 4261 // cv-unqualified object type and VQ is either volatile or 4262 // empty, there exist candidate operator functions of the form 4263 // 4264 // T*VQ& operator+=(T*VQ&, ptrdiff_t); 4265 // T*VQ& operator-=(T*VQ&, ptrdiff_t); 4266 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 4267 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4268 QualType ParamTypes[2]; 4269 ParamTypes[1] = (Op == OO_Equal)? *Ptr : Context.getPointerDiffType(); 4270 4271 // non-volatile version 4272 ParamTypes[0] = Context.getLValueReferenceType(*Ptr); 4273 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4274 /*IsAssigmentOperator=*/Op == OO_Equal); 4275 4276 if (!Context.getCanonicalType(*Ptr).isVolatileQualified() && 4277 VisibleTypeConversionsQuals.hasVolatile()) { 4278 // volatile version 4279 ParamTypes[0] 4280 = Context.getLValueReferenceType(Context.getVolatileType(*Ptr)); 4281 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4282 /*IsAssigmentOperator=*/Op == OO_Equal); 4283 } 4284 } 4285 // Fall through. 4286 4287 case OO_StarEqual: 4288 case OO_SlashEqual: 4289 // C++ [over.built]p18: 4290 // 4291 // For every triple (L, VQ, R), where L is an arithmetic type, 4292 // VQ is either volatile or empty, and R is a promoted 4293 // arithmetic type, there exist candidate operator functions of 4294 // the form 4295 // 4296 // VQ L& operator=(VQ L&, R); 4297 // VQ L& operator*=(VQ L&, R); 4298 // VQ L& operator/=(VQ L&, R); 4299 // VQ L& operator+=(VQ L&, R); 4300 // VQ L& operator-=(VQ L&, R); 4301 for (unsigned Left = 0; Left < NumArithmeticTypes; ++Left) { 4302 for (unsigned Right = FirstPromotedArithmeticType; 4303 Right < LastPromotedArithmeticType; ++Right) { 4304 QualType ParamTypes[2]; 4305 ParamTypes[1] = ArithmeticTypes[Right]; 4306 4307 // Add this built-in operator as a candidate (VQ is empty). 4308 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 4309 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4310 /*IsAssigmentOperator=*/Op == OO_Equal); 4311 4312 // Add this built-in operator as a candidate (VQ is 'volatile'). 4313 if (VisibleTypeConversionsQuals.hasVolatile()) { 4314 ParamTypes[0] = Context.getVolatileType(ArithmeticTypes[Left]); 4315 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 4316 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4317 /*IsAssigmentOperator=*/Op == OO_Equal); 4318 } 4319 } 4320 } 4321 break; 4322 4323 case OO_PercentEqual: 4324 case OO_LessLessEqual: 4325 case OO_GreaterGreaterEqual: 4326 case OO_AmpEqual: 4327 case OO_CaretEqual: 4328 case OO_PipeEqual: 4329 // C++ [over.built]p22: 4330 // 4331 // For every triple (L, VQ, R), where L is an integral type, VQ 4332 // is either volatile or empty, and R is a promoted integral 4333 // type, there exist candidate operator functions of the form 4334 // 4335 // VQ L& operator%=(VQ L&, R); 4336 // VQ L& operator<<=(VQ L&, R); 4337 // VQ L& operator>>=(VQ L&, R); 4338 // VQ L& operator&=(VQ L&, R); 4339 // VQ L& operator^=(VQ L&, R); 4340 // VQ L& operator|=(VQ L&, R); 4341 for (unsigned Left = FirstIntegralType; Left < LastIntegralType; ++Left) { 4342 for (unsigned Right = FirstPromotedIntegralType; 4343 Right < LastPromotedIntegralType; ++Right) { 4344 QualType ParamTypes[2]; 4345 ParamTypes[1] = ArithmeticTypes[Right]; 4346 4347 // Add this built-in operator as a candidate (VQ is empty). 4348 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 4349 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 4350 if (VisibleTypeConversionsQuals.hasVolatile()) { 4351 // Add this built-in operator as a candidate (VQ is 'volatile'). 4352 ParamTypes[0] = ArithmeticTypes[Left]; 4353 ParamTypes[0] = Context.getVolatileType(ParamTypes[0]); 4354 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 4355 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 4356 } 4357 } 4358 } 4359 break; 4360 4361 case OO_Exclaim: { 4362 // C++ [over.operator]p23: 4363 // 4364 // There also exist candidate operator functions of the form 4365 // 4366 // bool operator!(bool); 4367 // bool operator&&(bool, bool); [BELOW] 4368 // bool operator||(bool, bool); [BELOW] 4369 QualType ParamTy = Context.BoolTy; 4370 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet, 4371 /*IsAssignmentOperator=*/false, 4372 /*NumContextualBoolArguments=*/1); 4373 break; 4374 } 4375 4376 case OO_AmpAmp: 4377 case OO_PipePipe: { 4378 // C++ [over.operator]p23: 4379 // 4380 // There also exist candidate operator functions of the form 4381 // 4382 // bool operator!(bool); [ABOVE] 4383 // bool operator&&(bool, bool); 4384 // bool operator||(bool, bool); 4385 QualType ParamTypes[2] = { Context.BoolTy, Context.BoolTy }; 4386 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet, 4387 /*IsAssignmentOperator=*/false, 4388 /*NumContextualBoolArguments=*/2); 4389 break; 4390 } 4391 4392 case OO_Subscript: 4393 // C++ [over.built]p13: 4394 // 4395 // For every cv-qualified or cv-unqualified object type T there 4396 // exist candidate operator functions of the form 4397 // 4398 // T* operator+(T*, ptrdiff_t); [ABOVE] 4399 // T& operator[](T*, ptrdiff_t); 4400 // T* operator-(T*, ptrdiff_t); [ABOVE] 4401 // T* operator+(ptrdiff_t, T*); [ABOVE] 4402 // T& operator[](ptrdiff_t, T*); 4403 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 4404 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4405 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 4406 QualType PointeeType = (*Ptr)->getAs<PointerType>()->getPointeeType(); 4407 QualType ResultTy = Context.getLValueReferenceType(PointeeType); 4408 4409 // T& operator[](T*, ptrdiff_t) 4410 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 4411 4412 // T& operator[](ptrdiff_t, T*); 4413 ParamTypes[0] = ParamTypes[1]; 4414 ParamTypes[1] = *Ptr; 4415 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 4416 } 4417 break; 4418 4419 case OO_ArrowStar: 4420 // C++ [over.built]p11: 4421 // For every quintuple (C1, C2, T, CV1, CV2), where C2 is a class type, 4422 // C1 is the same type as C2 or is a derived class of C2, T is an object 4423 // type or a function type, and CV1 and CV2 are cv-qualifier-seqs, 4424 // there exist candidate operator functions of the form 4425 // CV12 T& operator->*(CV1 C1*, CV2 T C2::*); 4426 // where CV12 is the union of CV1 and CV2. 4427 { 4428 for (BuiltinCandidateTypeSet::iterator Ptr = 4429 CandidateTypes.pointer_begin(); 4430 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4431 QualType C1Ty = (*Ptr); 4432 QualType C1; 4433 QualifierCollector Q1; 4434 if (const PointerType *PointerTy = C1Ty->getAs<PointerType>()) { 4435 C1 = QualType(Q1.strip(PointerTy->getPointeeType()), 0); 4436 if (!isa<RecordType>(C1)) 4437 continue; 4438 // heuristic to reduce number of builtin candidates in the set. 4439 // Add volatile/restrict version only if there are conversions to a 4440 // volatile/restrict type. 4441 if (!VisibleTypeConversionsQuals.hasVolatile() && Q1.hasVolatile()) 4442 continue; 4443 if (!VisibleTypeConversionsQuals.hasRestrict() && Q1.hasRestrict()) 4444 continue; 4445 } 4446 for (BuiltinCandidateTypeSet::iterator 4447 MemPtr = CandidateTypes.member_pointer_begin(), 4448 MemPtrEnd = CandidateTypes.member_pointer_end(); 4449 MemPtr != MemPtrEnd; ++MemPtr) { 4450 const MemberPointerType *mptr = cast<MemberPointerType>(*MemPtr); 4451 QualType C2 = QualType(mptr->getClass(), 0); 4452 C2 = C2.getUnqualifiedType(); 4453 if (C1 != C2 && !IsDerivedFrom(C1, C2)) 4454 break; 4455 QualType ParamTypes[2] = { *Ptr, *MemPtr }; 4456 // build CV12 T& 4457 QualType T = mptr->getPointeeType(); 4458 if (!VisibleTypeConversionsQuals.hasVolatile() && 4459 T.isVolatileQualified()) 4460 continue; 4461 if (!VisibleTypeConversionsQuals.hasRestrict() && 4462 T.isRestrictQualified()) 4463 continue; 4464 T = Q1.apply(T); 4465 QualType ResultTy = Context.getLValueReferenceType(T); 4466 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 4467 } 4468 } 4469 } 4470 break; 4471 4472 case OO_Conditional: 4473 // Note that we don't consider the first argument, since it has been 4474 // contextually converted to bool long ago. The candidates below are 4475 // therefore added as binary. 4476 // 4477 // C++ [over.built]p24: 4478 // For every type T, where T is a pointer or pointer-to-member type, 4479 // there exist candidate operator functions of the form 4480 // 4481 // T operator?(bool, T, T); 4482 // 4483 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(), 4484 E = CandidateTypes.pointer_end(); Ptr != E; ++Ptr) { 4485 QualType ParamTypes[2] = { *Ptr, *Ptr }; 4486 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 4487 } 4488 for (BuiltinCandidateTypeSet::iterator Ptr = 4489 CandidateTypes.member_pointer_begin(), 4490 E = CandidateTypes.member_pointer_end(); Ptr != E; ++Ptr) { 4491 QualType ParamTypes[2] = { *Ptr, *Ptr }; 4492 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 4493 } 4494 goto Conditional; 4495 } 4496} 4497 4498/// \brief Add function candidates found via argument-dependent lookup 4499/// to the set of overloading candidates. 4500/// 4501/// This routine performs argument-dependent name lookup based on the 4502/// given function name (which may also be an operator name) and adds 4503/// all of the overload candidates found by ADL to the overload 4504/// candidate set (C++ [basic.lookup.argdep]). 4505void 4506Sema::AddArgumentDependentLookupCandidates(DeclarationName Name, 4507 bool Operator, 4508 Expr **Args, unsigned NumArgs, 4509 const TemplateArgumentListInfo *ExplicitTemplateArgs, 4510 OverloadCandidateSet& CandidateSet, 4511 bool PartialOverloading) { 4512 ADLResult Fns; 4513 4514 // FIXME: This approach for uniquing ADL results (and removing 4515 // redundant candidates from the set) relies on pointer-equality, 4516 // which means we need to key off the canonical decl. However, 4517 // always going back to the canonical decl might not get us the 4518 // right set of default arguments. What default arguments are 4519 // we supposed to consider on ADL candidates, anyway? 4520 4521 // FIXME: Pass in the explicit template arguments? 4522 ArgumentDependentLookup(Name, Operator, Args, NumArgs, Fns); 4523 4524 // Erase all of the candidates we already knew about. 4525 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 4526 CandEnd = CandidateSet.end(); 4527 Cand != CandEnd; ++Cand) 4528 if (Cand->Function) { 4529 Fns.erase(Cand->Function); 4530 if (FunctionTemplateDecl *FunTmpl = Cand->Function->getPrimaryTemplate()) 4531 Fns.erase(FunTmpl); 4532 } 4533 4534 // For each of the ADL candidates we found, add it to the overload 4535 // set. 4536 for (ADLResult::iterator I = Fns.begin(), E = Fns.end(); I != E; ++I) { 4537 DeclAccessPair FoundDecl = DeclAccessPair::make(*I, AS_none); 4538 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*I)) { 4539 if (ExplicitTemplateArgs) 4540 continue; 4541 4542 AddOverloadCandidate(FD, FoundDecl, Args, NumArgs, CandidateSet, 4543 false, PartialOverloading); 4544 } else 4545 AddTemplateOverloadCandidate(cast<FunctionTemplateDecl>(*I), 4546 FoundDecl, ExplicitTemplateArgs, 4547 Args, NumArgs, CandidateSet); 4548 } 4549} 4550 4551/// isBetterOverloadCandidate - Determines whether the first overload 4552/// candidate is a better candidate than the second (C++ 13.3.3p1). 4553bool 4554Sema::isBetterOverloadCandidate(const OverloadCandidate& Cand1, 4555 const OverloadCandidate& Cand2, 4556 SourceLocation Loc) { 4557 // Define viable functions to be better candidates than non-viable 4558 // functions. 4559 if (!Cand2.Viable) 4560 return Cand1.Viable; 4561 else if (!Cand1.Viable) 4562 return false; 4563 4564 // C++ [over.match.best]p1: 4565 // 4566 // -- if F is a static member function, ICS1(F) is defined such 4567 // that ICS1(F) is neither better nor worse than ICS1(G) for 4568 // any function G, and, symmetrically, ICS1(G) is neither 4569 // better nor worse than ICS1(F). 4570 unsigned StartArg = 0; 4571 if (Cand1.IgnoreObjectArgument || Cand2.IgnoreObjectArgument) 4572 StartArg = 1; 4573 4574 // C++ [over.match.best]p1: 4575 // A viable function F1 is defined to be a better function than another 4576 // viable function F2 if for all arguments i, ICSi(F1) is not a worse 4577 // conversion sequence than ICSi(F2), and then... 4578 unsigned NumArgs = Cand1.Conversions.size(); 4579 assert(Cand2.Conversions.size() == NumArgs && "Overload candidate mismatch"); 4580 bool HasBetterConversion = false; 4581 for (unsigned ArgIdx = StartArg; ArgIdx < NumArgs; ++ArgIdx) { 4582 switch (CompareImplicitConversionSequences(Cand1.Conversions[ArgIdx], 4583 Cand2.Conversions[ArgIdx])) { 4584 case ImplicitConversionSequence::Better: 4585 // Cand1 has a better conversion sequence. 4586 HasBetterConversion = true; 4587 break; 4588 4589 case ImplicitConversionSequence::Worse: 4590 // Cand1 can't be better than Cand2. 4591 return false; 4592 4593 case ImplicitConversionSequence::Indistinguishable: 4594 // Do nothing. 4595 break; 4596 } 4597 } 4598 4599 // -- for some argument j, ICSj(F1) is a better conversion sequence than 4600 // ICSj(F2), or, if not that, 4601 if (HasBetterConversion) 4602 return true; 4603 4604 // - F1 is a non-template function and F2 is a function template 4605 // specialization, or, if not that, 4606 if (Cand1.Function && !Cand1.Function->getPrimaryTemplate() && 4607 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 4608 return true; 4609 4610 // -- F1 and F2 are function template specializations, and the function 4611 // template for F1 is more specialized than the template for F2 4612 // according to the partial ordering rules described in 14.5.5.2, or, 4613 // if not that, 4614 if (Cand1.Function && Cand1.Function->getPrimaryTemplate() && 4615 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 4616 if (FunctionTemplateDecl *BetterTemplate 4617 = getMoreSpecializedTemplate(Cand1.Function->getPrimaryTemplate(), 4618 Cand2.Function->getPrimaryTemplate(), 4619 Loc, 4620 isa<CXXConversionDecl>(Cand1.Function)? TPOC_Conversion 4621 : TPOC_Call)) 4622 return BetterTemplate == Cand1.Function->getPrimaryTemplate(); 4623 4624 // -- the context is an initialization by user-defined conversion 4625 // (see 8.5, 13.3.1.5) and the standard conversion sequence 4626 // from the return type of F1 to the destination type (i.e., 4627 // the type of the entity being initialized) is a better 4628 // conversion sequence than the standard conversion sequence 4629 // from the return type of F2 to the destination type. 4630 if (Cand1.Function && Cand2.Function && 4631 isa<CXXConversionDecl>(Cand1.Function) && 4632 isa<CXXConversionDecl>(Cand2.Function)) { 4633 switch (CompareStandardConversionSequences(Cand1.FinalConversion, 4634 Cand2.FinalConversion)) { 4635 case ImplicitConversionSequence::Better: 4636 // Cand1 has a better conversion sequence. 4637 return true; 4638 4639 case ImplicitConversionSequence::Worse: 4640 // Cand1 can't be better than Cand2. 4641 return false; 4642 4643 case ImplicitConversionSequence::Indistinguishable: 4644 // Do nothing 4645 break; 4646 } 4647 } 4648 4649 return false; 4650} 4651 4652/// \brief Computes the best viable function (C++ 13.3.3) 4653/// within an overload candidate set. 4654/// 4655/// \param CandidateSet the set of candidate functions. 4656/// 4657/// \param Loc the location of the function name (or operator symbol) for 4658/// which overload resolution occurs. 4659/// 4660/// \param Best f overload resolution was successful or found a deleted 4661/// function, Best points to the candidate function found. 4662/// 4663/// \returns The result of overload resolution. 4664OverloadingResult Sema::BestViableFunction(OverloadCandidateSet& CandidateSet, 4665 SourceLocation Loc, 4666 OverloadCandidateSet::iterator& Best) { 4667 // Find the best viable function. 4668 Best = CandidateSet.end(); 4669 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 4670 Cand != CandidateSet.end(); ++Cand) { 4671 if (Cand->Viable) { 4672 if (Best == CandidateSet.end() || 4673 isBetterOverloadCandidate(*Cand, *Best, Loc)) 4674 Best = Cand; 4675 } 4676 } 4677 4678 // If we didn't find any viable functions, abort. 4679 if (Best == CandidateSet.end()) 4680 return OR_No_Viable_Function; 4681 4682 // Make sure that this function is better than every other viable 4683 // function. If not, we have an ambiguity. 4684 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 4685 Cand != CandidateSet.end(); ++Cand) { 4686 if (Cand->Viable && 4687 Cand != Best && 4688 !isBetterOverloadCandidate(*Best, *Cand, Loc)) { 4689 Best = CandidateSet.end(); 4690 return OR_Ambiguous; 4691 } 4692 } 4693 4694 // Best is the best viable function. 4695 if (Best->Function && 4696 (Best->Function->isDeleted() || 4697 Best->Function->getAttr<UnavailableAttr>())) 4698 return OR_Deleted; 4699 4700 // C++ [basic.def.odr]p2: 4701 // An overloaded function is used if it is selected by overload resolution 4702 // when referred to from a potentially-evaluated expression. [Note: this 4703 // covers calls to named functions (5.2.2), operator overloading 4704 // (clause 13), user-defined conversions (12.3.2), allocation function for 4705 // placement new (5.3.4), as well as non-default initialization (8.5). 4706 if (Best->Function) 4707 MarkDeclarationReferenced(Loc, Best->Function); 4708 return OR_Success; 4709} 4710 4711namespace { 4712 4713enum OverloadCandidateKind { 4714 oc_function, 4715 oc_method, 4716 oc_constructor, 4717 oc_function_template, 4718 oc_method_template, 4719 oc_constructor_template, 4720 oc_implicit_default_constructor, 4721 oc_implicit_copy_constructor, 4722 oc_implicit_copy_assignment 4723}; 4724 4725OverloadCandidateKind ClassifyOverloadCandidate(Sema &S, 4726 FunctionDecl *Fn, 4727 std::string &Description) { 4728 bool isTemplate = false; 4729 4730 if (FunctionTemplateDecl *FunTmpl = Fn->getPrimaryTemplate()) { 4731 isTemplate = true; 4732 Description = S.getTemplateArgumentBindingsText( 4733 FunTmpl->getTemplateParameters(), *Fn->getTemplateSpecializationArgs()); 4734 } 4735 4736 if (CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(Fn)) { 4737 if (!Ctor->isImplicit()) 4738 return isTemplate ? oc_constructor_template : oc_constructor; 4739 4740 return Ctor->isCopyConstructor() ? oc_implicit_copy_constructor 4741 : oc_implicit_default_constructor; 4742 } 4743 4744 if (CXXMethodDecl *Meth = dyn_cast<CXXMethodDecl>(Fn)) { 4745 // This actually gets spelled 'candidate function' for now, but 4746 // it doesn't hurt to split it out. 4747 if (!Meth->isImplicit()) 4748 return isTemplate ? oc_method_template : oc_method; 4749 4750 assert(Meth->isCopyAssignment() 4751 && "implicit method is not copy assignment operator?"); 4752 return oc_implicit_copy_assignment; 4753 } 4754 4755 return isTemplate ? oc_function_template : oc_function; 4756} 4757 4758} // end anonymous namespace 4759 4760// Notes the location of an overload candidate. 4761void Sema::NoteOverloadCandidate(FunctionDecl *Fn) { 4762 std::string FnDesc; 4763 OverloadCandidateKind K = ClassifyOverloadCandidate(*this, Fn, FnDesc); 4764 Diag(Fn->getLocation(), diag::note_ovl_candidate) 4765 << (unsigned) K << FnDesc; 4766} 4767 4768/// Diagnoses an ambiguous conversion. The partial diagnostic is the 4769/// "lead" diagnostic; it will be given two arguments, the source and 4770/// target types of the conversion. 4771void Sema::DiagnoseAmbiguousConversion(const ImplicitConversionSequence &ICS, 4772 SourceLocation CaretLoc, 4773 const PartialDiagnostic &PDiag) { 4774 Diag(CaretLoc, PDiag) 4775 << ICS.Ambiguous.getFromType() << ICS.Ambiguous.getToType(); 4776 for (AmbiguousConversionSequence::const_iterator 4777 I = ICS.Ambiguous.begin(), E = ICS.Ambiguous.end(); I != E; ++I) { 4778 NoteOverloadCandidate(*I); 4779 } 4780} 4781 4782namespace { 4783 4784void DiagnoseBadConversion(Sema &S, OverloadCandidate *Cand, unsigned I) { 4785 const ImplicitConversionSequence &Conv = Cand->Conversions[I]; 4786 assert(Conv.isBad()); 4787 assert(Cand->Function && "for now, candidate must be a function"); 4788 FunctionDecl *Fn = Cand->Function; 4789 4790 // There's a conversion slot for the object argument if this is a 4791 // non-constructor method. Note that 'I' corresponds the 4792 // conversion-slot index. 4793 bool isObjectArgument = false; 4794 if (isa<CXXMethodDecl>(Fn) && !isa<CXXConstructorDecl>(Fn)) { 4795 if (I == 0) 4796 isObjectArgument = true; 4797 else 4798 I--; 4799 } 4800 4801 std::string FnDesc; 4802 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, FnDesc); 4803 4804 Expr *FromExpr = Conv.Bad.FromExpr; 4805 QualType FromTy = Conv.Bad.getFromType(); 4806 QualType ToTy = Conv.Bad.getToType(); 4807 4808 if (FromTy == S.Context.OverloadTy) { 4809 assert(FromExpr && "overload set argument came from implicit argument?"); 4810 Expr *E = FromExpr->IgnoreParens(); 4811 if (isa<UnaryOperator>(E)) 4812 E = cast<UnaryOperator>(E)->getSubExpr()->IgnoreParens(); 4813 DeclarationName Name = cast<OverloadExpr>(E)->getName(); 4814 4815 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_overload) 4816 << (unsigned) FnKind << FnDesc 4817 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 4818 << ToTy << Name << I+1; 4819 return; 4820 } 4821 4822 // Do some hand-waving analysis to see if the non-viability is due 4823 // to a qualifier mismatch. 4824 CanQualType CFromTy = S.Context.getCanonicalType(FromTy); 4825 CanQualType CToTy = S.Context.getCanonicalType(ToTy); 4826 if (CanQual<ReferenceType> RT = CToTy->getAs<ReferenceType>()) 4827 CToTy = RT->getPointeeType(); 4828 else { 4829 // TODO: detect and diagnose the full richness of const mismatches. 4830 if (CanQual<PointerType> FromPT = CFromTy->getAs<PointerType>()) 4831 if (CanQual<PointerType> ToPT = CToTy->getAs<PointerType>()) 4832 CFromTy = FromPT->getPointeeType(), CToTy = ToPT->getPointeeType(); 4833 } 4834 4835 if (CToTy.getUnqualifiedType() == CFromTy.getUnqualifiedType() && 4836 !CToTy.isAtLeastAsQualifiedAs(CFromTy)) { 4837 // It is dumb that we have to do this here. 4838 while (isa<ArrayType>(CFromTy)) 4839 CFromTy = CFromTy->getAs<ArrayType>()->getElementType(); 4840 while (isa<ArrayType>(CToTy)) 4841 CToTy = CFromTy->getAs<ArrayType>()->getElementType(); 4842 4843 Qualifiers FromQs = CFromTy.getQualifiers(); 4844 Qualifiers ToQs = CToTy.getQualifiers(); 4845 4846 if (FromQs.getAddressSpace() != ToQs.getAddressSpace()) { 4847 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_addrspace) 4848 << (unsigned) FnKind << FnDesc 4849 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 4850 << FromTy 4851 << FromQs.getAddressSpace() << ToQs.getAddressSpace() 4852 << (unsigned) isObjectArgument << I+1; 4853 return; 4854 } 4855 4856 unsigned CVR = FromQs.getCVRQualifiers() & ~ToQs.getCVRQualifiers(); 4857 assert(CVR && "unexpected qualifiers mismatch"); 4858 4859 if (isObjectArgument) { 4860 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr_this) 4861 << (unsigned) FnKind << FnDesc 4862 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 4863 << FromTy << (CVR - 1); 4864 } else { 4865 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr) 4866 << (unsigned) FnKind << FnDesc 4867 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 4868 << FromTy << (CVR - 1) << I+1; 4869 } 4870 return; 4871 } 4872 4873 // Diagnose references or pointers to incomplete types differently, 4874 // since it's far from impossible that the incompleteness triggered 4875 // the failure. 4876 QualType TempFromTy = FromTy.getNonReferenceType(); 4877 if (const PointerType *PTy = TempFromTy->getAs<PointerType>()) 4878 TempFromTy = PTy->getPointeeType(); 4879 if (TempFromTy->isIncompleteType()) { 4880 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_conv_incomplete) 4881 << (unsigned) FnKind << FnDesc 4882 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 4883 << FromTy << ToTy << (unsigned) isObjectArgument << I+1; 4884 return; 4885 } 4886 4887 // TODO: specialize more based on the kind of mismatch 4888 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_conv) 4889 << (unsigned) FnKind << FnDesc 4890 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 4891 << FromTy << ToTy << (unsigned) isObjectArgument << I+1; 4892} 4893 4894void DiagnoseArityMismatch(Sema &S, OverloadCandidate *Cand, 4895 unsigned NumFormalArgs) { 4896 // TODO: treat calls to a missing default constructor as a special case 4897 4898 FunctionDecl *Fn = Cand->Function; 4899 const FunctionProtoType *FnTy = Fn->getType()->getAs<FunctionProtoType>(); 4900 4901 unsigned MinParams = Fn->getMinRequiredArguments(); 4902 4903 // at least / at most / exactly 4904 unsigned mode, modeCount; 4905 if (NumFormalArgs < MinParams) { 4906 assert(Cand->FailureKind == ovl_fail_too_few_arguments); 4907 if (MinParams != FnTy->getNumArgs() || FnTy->isVariadic()) 4908 mode = 0; // "at least" 4909 else 4910 mode = 2; // "exactly" 4911 modeCount = MinParams; 4912 } else { 4913 assert(Cand->FailureKind == ovl_fail_too_many_arguments); 4914 if (MinParams != FnTy->getNumArgs()) 4915 mode = 1; // "at most" 4916 else 4917 mode = 2; // "exactly" 4918 modeCount = FnTy->getNumArgs(); 4919 } 4920 4921 std::string Description; 4922 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, Description); 4923 4924 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_arity) 4925 << (unsigned) FnKind << Description << mode << modeCount << NumFormalArgs; 4926} 4927 4928/// Diagnose a failed template-argument deduction. 4929void DiagnoseBadDeduction(Sema &S, OverloadCandidate *Cand, 4930 Expr **Args, unsigned NumArgs) { 4931 FunctionDecl *Fn = Cand->Function; // pattern 4932 4933 TemplateParameter Param = TemplateParameter::getFromOpaqueValue( 4934 Cand->DeductionFailure.TemplateParameter); 4935 4936 switch (Cand->DeductionFailure.Result) { 4937 case Sema::TDK_Success: 4938 llvm_unreachable("TDK_success while diagnosing bad deduction"); 4939 4940 case Sema::TDK_Incomplete: { 4941 NamedDecl *ParamD; 4942 (ParamD = Param.dyn_cast<TemplateTypeParmDecl*>()) || 4943 (ParamD = Param.dyn_cast<NonTypeTemplateParmDecl*>()) || 4944 (ParamD = Param.dyn_cast<TemplateTemplateParmDecl*>()); 4945 assert(ParamD && "no parameter found for incomplete deduction result"); 4946 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_incomplete_deduction) 4947 << ParamD->getDeclName(); 4948 return; 4949 } 4950 4951 // TODO: diagnose these individually, then kill off 4952 // note_ovl_candidate_bad_deduction, which is uselessly vague. 4953 case Sema::TDK_InstantiationDepth: 4954 case Sema::TDK_Inconsistent: 4955 case Sema::TDK_InconsistentQuals: 4956 case Sema::TDK_SubstitutionFailure: 4957 case Sema::TDK_NonDeducedMismatch: 4958 case Sema::TDK_TooManyArguments: 4959 case Sema::TDK_TooFewArguments: 4960 case Sema::TDK_InvalidExplicitArguments: 4961 case Sema::TDK_FailedOverloadResolution: 4962 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_deduction); 4963 return; 4964 } 4965} 4966 4967/// Generates a 'note' diagnostic for an overload candidate. We've 4968/// already generated a primary error at the call site. 4969/// 4970/// It really does need to be a single diagnostic with its caret 4971/// pointed at the candidate declaration. Yes, this creates some 4972/// major challenges of technical writing. Yes, this makes pointing 4973/// out problems with specific arguments quite awkward. It's still 4974/// better than generating twenty screens of text for every failed 4975/// overload. 4976/// 4977/// It would be great to be able to express per-candidate problems 4978/// more richly for those diagnostic clients that cared, but we'd 4979/// still have to be just as careful with the default diagnostics. 4980void NoteFunctionCandidate(Sema &S, OverloadCandidate *Cand, 4981 Expr **Args, unsigned NumArgs) { 4982 FunctionDecl *Fn = Cand->Function; 4983 4984 // Note deleted candidates, but only if they're viable. 4985 if (Cand->Viable && (Fn->isDeleted() || Fn->hasAttr<UnavailableAttr>())) { 4986 std::string FnDesc; 4987 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, FnDesc); 4988 4989 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_deleted) 4990 << FnKind << FnDesc << Fn->isDeleted(); 4991 return; 4992 } 4993 4994 // We don't really have anything else to say about viable candidates. 4995 if (Cand->Viable) { 4996 S.NoteOverloadCandidate(Fn); 4997 return; 4998 } 4999 5000 switch (Cand->FailureKind) { 5001 case ovl_fail_too_many_arguments: 5002 case ovl_fail_too_few_arguments: 5003 return DiagnoseArityMismatch(S, Cand, NumArgs); 5004 5005 case ovl_fail_bad_deduction: 5006 return DiagnoseBadDeduction(S, Cand, Args, NumArgs); 5007 5008 case ovl_fail_trivial_conversion: 5009 case ovl_fail_bad_final_conversion: 5010 case ovl_fail_final_conversion_not_exact: 5011 return S.NoteOverloadCandidate(Fn); 5012 5013 case ovl_fail_bad_conversion: { 5014 unsigned I = (Cand->IgnoreObjectArgument ? 1 : 0); 5015 for (unsigned N = Cand->Conversions.size(); I != N; ++I) 5016 if (Cand->Conversions[I].isBad()) 5017 return DiagnoseBadConversion(S, Cand, I); 5018 5019 // FIXME: this currently happens when we're called from SemaInit 5020 // when user-conversion overload fails. Figure out how to handle 5021 // those conditions and diagnose them well. 5022 return S.NoteOverloadCandidate(Fn); 5023 } 5024 } 5025} 5026 5027void NoteSurrogateCandidate(Sema &S, OverloadCandidate *Cand) { 5028 // Desugar the type of the surrogate down to a function type, 5029 // retaining as many typedefs as possible while still showing 5030 // the function type (and, therefore, its parameter types). 5031 QualType FnType = Cand->Surrogate->getConversionType(); 5032 bool isLValueReference = false; 5033 bool isRValueReference = false; 5034 bool isPointer = false; 5035 if (const LValueReferenceType *FnTypeRef = 5036 FnType->getAs<LValueReferenceType>()) { 5037 FnType = FnTypeRef->getPointeeType(); 5038 isLValueReference = true; 5039 } else if (const RValueReferenceType *FnTypeRef = 5040 FnType->getAs<RValueReferenceType>()) { 5041 FnType = FnTypeRef->getPointeeType(); 5042 isRValueReference = true; 5043 } 5044 if (const PointerType *FnTypePtr = FnType->getAs<PointerType>()) { 5045 FnType = FnTypePtr->getPointeeType(); 5046 isPointer = true; 5047 } 5048 // Desugar down to a function type. 5049 FnType = QualType(FnType->getAs<FunctionType>(), 0); 5050 // Reconstruct the pointer/reference as appropriate. 5051 if (isPointer) FnType = S.Context.getPointerType(FnType); 5052 if (isRValueReference) FnType = S.Context.getRValueReferenceType(FnType); 5053 if (isLValueReference) FnType = S.Context.getLValueReferenceType(FnType); 5054 5055 S.Diag(Cand->Surrogate->getLocation(), diag::note_ovl_surrogate_cand) 5056 << FnType; 5057} 5058 5059void NoteBuiltinOperatorCandidate(Sema &S, 5060 const char *Opc, 5061 SourceLocation OpLoc, 5062 OverloadCandidate *Cand) { 5063 assert(Cand->Conversions.size() <= 2 && "builtin operator is not binary"); 5064 std::string TypeStr("operator"); 5065 TypeStr += Opc; 5066 TypeStr += "("; 5067 TypeStr += Cand->BuiltinTypes.ParamTypes[0].getAsString(); 5068 if (Cand->Conversions.size() == 1) { 5069 TypeStr += ")"; 5070 S.Diag(OpLoc, diag::note_ovl_builtin_unary_candidate) << TypeStr; 5071 } else { 5072 TypeStr += ", "; 5073 TypeStr += Cand->BuiltinTypes.ParamTypes[1].getAsString(); 5074 TypeStr += ")"; 5075 S.Diag(OpLoc, diag::note_ovl_builtin_binary_candidate) << TypeStr; 5076 } 5077} 5078 5079void NoteAmbiguousUserConversions(Sema &S, SourceLocation OpLoc, 5080 OverloadCandidate *Cand) { 5081 unsigned NoOperands = Cand->Conversions.size(); 5082 for (unsigned ArgIdx = 0; ArgIdx < NoOperands; ++ArgIdx) { 5083 const ImplicitConversionSequence &ICS = Cand->Conversions[ArgIdx]; 5084 if (ICS.isBad()) break; // all meaningless after first invalid 5085 if (!ICS.isAmbiguous()) continue; 5086 5087 S.DiagnoseAmbiguousConversion(ICS, OpLoc, 5088 S.PDiag(diag::note_ambiguous_type_conversion)); 5089 } 5090} 5091 5092SourceLocation GetLocationForCandidate(const OverloadCandidate *Cand) { 5093 if (Cand->Function) 5094 return Cand->Function->getLocation(); 5095 if (Cand->IsSurrogate) 5096 return Cand->Surrogate->getLocation(); 5097 return SourceLocation(); 5098} 5099 5100struct CompareOverloadCandidatesForDisplay { 5101 Sema &S; 5102 CompareOverloadCandidatesForDisplay(Sema &S) : S(S) {} 5103 5104 bool operator()(const OverloadCandidate *L, 5105 const OverloadCandidate *R) { 5106 // Fast-path this check. 5107 if (L == R) return false; 5108 5109 // Order first by viability. 5110 if (L->Viable) { 5111 if (!R->Viable) return true; 5112 5113 // TODO: introduce a tri-valued comparison for overload 5114 // candidates. Would be more worthwhile if we had a sort 5115 // that could exploit it. 5116 if (S.isBetterOverloadCandidate(*L, *R, SourceLocation())) return true; 5117 if (S.isBetterOverloadCandidate(*R, *L, SourceLocation())) return false; 5118 } else if (R->Viable) 5119 return false; 5120 5121 assert(L->Viable == R->Viable); 5122 5123 // Criteria by which we can sort non-viable candidates: 5124 if (!L->Viable) { 5125 // 1. Arity mismatches come after other candidates. 5126 if (L->FailureKind == ovl_fail_too_many_arguments || 5127 L->FailureKind == ovl_fail_too_few_arguments) 5128 return false; 5129 if (R->FailureKind == ovl_fail_too_many_arguments || 5130 R->FailureKind == ovl_fail_too_few_arguments) 5131 return true; 5132 5133 // 2. Bad conversions come first and are ordered by the number 5134 // of bad conversions and quality of good conversions. 5135 if (L->FailureKind == ovl_fail_bad_conversion) { 5136 if (R->FailureKind != ovl_fail_bad_conversion) 5137 return true; 5138 5139 // If there's any ordering between the defined conversions... 5140 // FIXME: this might not be transitive. 5141 assert(L->Conversions.size() == R->Conversions.size()); 5142 5143 int leftBetter = 0; 5144 unsigned I = (L->IgnoreObjectArgument || R->IgnoreObjectArgument); 5145 for (unsigned E = L->Conversions.size(); I != E; ++I) { 5146 switch (S.CompareImplicitConversionSequences(L->Conversions[I], 5147 R->Conversions[I])) { 5148 case ImplicitConversionSequence::Better: 5149 leftBetter++; 5150 break; 5151 5152 case ImplicitConversionSequence::Worse: 5153 leftBetter--; 5154 break; 5155 5156 case ImplicitConversionSequence::Indistinguishable: 5157 break; 5158 } 5159 } 5160 if (leftBetter > 0) return true; 5161 if (leftBetter < 0) return false; 5162 5163 } else if (R->FailureKind == ovl_fail_bad_conversion) 5164 return false; 5165 5166 // TODO: others? 5167 } 5168 5169 // Sort everything else by location. 5170 SourceLocation LLoc = GetLocationForCandidate(L); 5171 SourceLocation RLoc = GetLocationForCandidate(R); 5172 5173 // Put candidates without locations (e.g. builtins) at the end. 5174 if (LLoc.isInvalid()) return false; 5175 if (RLoc.isInvalid()) return true; 5176 5177 return S.SourceMgr.isBeforeInTranslationUnit(LLoc, RLoc); 5178 } 5179}; 5180 5181/// CompleteNonViableCandidate - Normally, overload resolution only 5182/// computes up to the first 5183void CompleteNonViableCandidate(Sema &S, OverloadCandidate *Cand, 5184 Expr **Args, unsigned NumArgs) { 5185 assert(!Cand->Viable); 5186 5187 // Don't do anything on failures other than bad conversion. 5188 if (Cand->FailureKind != ovl_fail_bad_conversion) return; 5189 5190 // Skip forward to the first bad conversion. 5191 unsigned ConvIdx = (Cand->IgnoreObjectArgument ? 1 : 0); 5192 unsigned ConvCount = Cand->Conversions.size(); 5193 while (true) { 5194 assert(ConvIdx != ConvCount && "no bad conversion in candidate"); 5195 ConvIdx++; 5196 if (Cand->Conversions[ConvIdx - 1].isBad()) 5197 break; 5198 } 5199 5200 if (ConvIdx == ConvCount) 5201 return; 5202 5203 assert(!Cand->Conversions[ConvIdx].isInitialized() && 5204 "remaining conversion is initialized?"); 5205 5206 // FIXME: this should probably be preserved from the overload 5207 // operation somehow. 5208 bool SuppressUserConversions = false; 5209 5210 const FunctionProtoType* Proto; 5211 unsigned ArgIdx = ConvIdx; 5212 5213 if (Cand->IsSurrogate) { 5214 QualType ConvType 5215 = Cand->Surrogate->getConversionType().getNonReferenceType(); 5216 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 5217 ConvType = ConvPtrType->getPointeeType(); 5218 Proto = ConvType->getAs<FunctionProtoType>(); 5219 ArgIdx--; 5220 } else if (Cand->Function) { 5221 Proto = Cand->Function->getType()->getAs<FunctionProtoType>(); 5222 if (isa<CXXMethodDecl>(Cand->Function) && 5223 !isa<CXXConstructorDecl>(Cand->Function)) 5224 ArgIdx--; 5225 } else { 5226 // Builtin binary operator with a bad first conversion. 5227 assert(ConvCount <= 3); 5228 for (; ConvIdx != ConvCount; ++ConvIdx) 5229 Cand->Conversions[ConvIdx] 5230 = TryCopyInitialization(S, Args[ConvIdx], 5231 Cand->BuiltinTypes.ParamTypes[ConvIdx], 5232 SuppressUserConversions, 5233 /*InOverloadResolution*/ true); 5234 return; 5235 } 5236 5237 // Fill in the rest of the conversions. 5238 unsigned NumArgsInProto = Proto->getNumArgs(); 5239 for (; ConvIdx != ConvCount; ++ConvIdx, ++ArgIdx) { 5240 if (ArgIdx < NumArgsInProto) 5241 Cand->Conversions[ConvIdx] 5242 = TryCopyInitialization(S, Args[ArgIdx], Proto->getArgType(ArgIdx), 5243 SuppressUserConversions, 5244 /*InOverloadResolution=*/true); 5245 else 5246 Cand->Conversions[ConvIdx].setEllipsis(); 5247 } 5248} 5249 5250} // end anonymous namespace 5251 5252/// PrintOverloadCandidates - When overload resolution fails, prints 5253/// diagnostic messages containing the candidates in the candidate 5254/// set. 5255void 5256Sema::PrintOverloadCandidates(OverloadCandidateSet& CandidateSet, 5257 OverloadCandidateDisplayKind OCD, 5258 Expr **Args, unsigned NumArgs, 5259 const char *Opc, 5260 SourceLocation OpLoc) { 5261 // Sort the candidates by viability and position. Sorting directly would 5262 // be prohibitive, so we make a set of pointers and sort those. 5263 llvm::SmallVector<OverloadCandidate*, 32> Cands; 5264 if (OCD == OCD_AllCandidates) Cands.reserve(CandidateSet.size()); 5265 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 5266 LastCand = CandidateSet.end(); 5267 Cand != LastCand; ++Cand) { 5268 if (Cand->Viable) 5269 Cands.push_back(Cand); 5270 else if (OCD == OCD_AllCandidates) { 5271 CompleteNonViableCandidate(*this, Cand, Args, NumArgs); 5272 Cands.push_back(Cand); 5273 } 5274 } 5275 5276 std::sort(Cands.begin(), Cands.end(), 5277 CompareOverloadCandidatesForDisplay(*this)); 5278 5279 bool ReportedAmbiguousConversions = false; 5280 5281 llvm::SmallVectorImpl<OverloadCandidate*>::iterator I, E; 5282 for (I = Cands.begin(), E = Cands.end(); I != E; ++I) { 5283 OverloadCandidate *Cand = *I; 5284 5285 if (Cand->Function) 5286 NoteFunctionCandidate(*this, Cand, Args, NumArgs); 5287 else if (Cand->IsSurrogate) 5288 NoteSurrogateCandidate(*this, Cand); 5289 5290 // This a builtin candidate. We do not, in general, want to list 5291 // every possible builtin candidate. 5292 else if (Cand->Viable) { 5293 // Generally we only see ambiguities including viable builtin 5294 // operators if overload resolution got screwed up by an 5295 // ambiguous user-defined conversion. 5296 // 5297 // FIXME: It's quite possible for different conversions to see 5298 // different ambiguities, though. 5299 if (!ReportedAmbiguousConversions) { 5300 NoteAmbiguousUserConversions(*this, OpLoc, Cand); 5301 ReportedAmbiguousConversions = true; 5302 } 5303 5304 // If this is a viable builtin, print it. 5305 NoteBuiltinOperatorCandidate(*this, Opc, OpLoc, Cand); 5306 } 5307 } 5308} 5309 5310static bool CheckUnresolvedAccess(Sema &S, OverloadExpr *E, DeclAccessPair D) { 5311 if (isa<UnresolvedLookupExpr>(E)) 5312 return S.CheckUnresolvedLookupAccess(cast<UnresolvedLookupExpr>(E), D); 5313 5314 return S.CheckUnresolvedMemberAccess(cast<UnresolvedMemberExpr>(E), D); 5315} 5316 5317/// ResolveAddressOfOverloadedFunction - Try to resolve the address of 5318/// an overloaded function (C++ [over.over]), where @p From is an 5319/// expression with overloaded function type and @p ToType is the type 5320/// we're trying to resolve to. For example: 5321/// 5322/// @code 5323/// int f(double); 5324/// int f(int); 5325/// 5326/// int (*pfd)(double) = f; // selects f(double) 5327/// @endcode 5328/// 5329/// This routine returns the resulting FunctionDecl if it could be 5330/// resolved, and NULL otherwise. When @p Complain is true, this 5331/// routine will emit diagnostics if there is an error. 5332FunctionDecl * 5333Sema::ResolveAddressOfOverloadedFunction(Expr *From, QualType ToType, 5334 bool Complain, 5335 DeclAccessPair &FoundResult) { 5336 QualType FunctionType = ToType; 5337 bool IsMember = false; 5338 if (const PointerType *ToTypePtr = ToType->getAs<PointerType>()) 5339 FunctionType = ToTypePtr->getPointeeType(); 5340 else if (const ReferenceType *ToTypeRef = ToType->getAs<ReferenceType>()) 5341 FunctionType = ToTypeRef->getPointeeType(); 5342 else if (const MemberPointerType *MemTypePtr = 5343 ToType->getAs<MemberPointerType>()) { 5344 FunctionType = MemTypePtr->getPointeeType(); 5345 IsMember = true; 5346 } 5347 5348 // C++ [over.over]p1: 5349 // [...] [Note: any redundant set of parentheses surrounding the 5350 // overloaded function name is ignored (5.1). ] 5351 // C++ [over.over]p1: 5352 // [...] The overloaded function name can be preceded by the & 5353 // operator. 5354 OverloadExpr *OvlExpr = OverloadExpr::find(From).getPointer(); 5355 TemplateArgumentListInfo ETABuffer, *ExplicitTemplateArgs = 0; 5356 if (OvlExpr->hasExplicitTemplateArgs()) { 5357 OvlExpr->getExplicitTemplateArgs().copyInto(ETABuffer); 5358 ExplicitTemplateArgs = &ETABuffer; 5359 } 5360 5361 // We expect a pointer or reference to function, or a function pointer. 5362 FunctionType = Context.getCanonicalType(FunctionType).getUnqualifiedType(); 5363 if (!FunctionType->isFunctionType()) { 5364 if (Complain) 5365 Diag(From->getLocStart(), diag::err_addr_ovl_not_func_ptrref) 5366 << OvlExpr->getName() << ToType; 5367 5368 return 0; 5369 } 5370 5371 assert(From->getType() == Context.OverloadTy); 5372 5373 // Look through all of the overloaded functions, searching for one 5374 // whose type matches exactly. 5375 llvm::SmallVector<std::pair<DeclAccessPair, FunctionDecl*>, 4> Matches; 5376 llvm::SmallVector<FunctionDecl *, 4> NonMatches; 5377 5378 bool FoundNonTemplateFunction = false; 5379 for (UnresolvedSetIterator I = OvlExpr->decls_begin(), 5380 E = OvlExpr->decls_end(); I != E; ++I) { 5381 // Look through any using declarations to find the underlying function. 5382 NamedDecl *Fn = (*I)->getUnderlyingDecl(); 5383 5384 // C++ [over.over]p3: 5385 // Non-member functions and static member functions match 5386 // targets of type "pointer-to-function" or "reference-to-function." 5387 // Nonstatic member functions match targets of 5388 // type "pointer-to-member-function." 5389 // Note that according to DR 247, the containing class does not matter. 5390 5391 if (FunctionTemplateDecl *FunctionTemplate 5392 = dyn_cast<FunctionTemplateDecl>(Fn)) { 5393 if (CXXMethodDecl *Method 5394 = dyn_cast<CXXMethodDecl>(FunctionTemplate->getTemplatedDecl())) { 5395 // Skip non-static function templates when converting to pointer, and 5396 // static when converting to member pointer. 5397 if (Method->isStatic() == IsMember) 5398 continue; 5399 } else if (IsMember) 5400 continue; 5401 5402 // C++ [over.over]p2: 5403 // If the name is a function template, template argument deduction is 5404 // done (14.8.2.2), and if the argument deduction succeeds, the 5405 // resulting template argument list is used to generate a single 5406 // function template specialization, which is added to the set of 5407 // overloaded functions considered. 5408 // FIXME: We don't really want to build the specialization here, do we? 5409 FunctionDecl *Specialization = 0; 5410 TemplateDeductionInfo Info(Context, OvlExpr->getNameLoc()); 5411 if (TemplateDeductionResult Result 5412 = DeduceTemplateArguments(FunctionTemplate, ExplicitTemplateArgs, 5413 FunctionType, Specialization, Info)) { 5414 // FIXME: make a note of the failed deduction for diagnostics. 5415 (void)Result; 5416 } else { 5417 // FIXME: If the match isn't exact, shouldn't we just drop this as 5418 // a candidate? Find a testcase before changing the code. 5419 assert(FunctionType 5420 == Context.getCanonicalType(Specialization->getType())); 5421 Matches.push_back(std::make_pair(I.getPair(), 5422 cast<FunctionDecl>(Specialization->getCanonicalDecl()))); 5423 } 5424 5425 continue; 5426 } 5427 5428 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 5429 // Skip non-static functions when converting to pointer, and static 5430 // when converting to member pointer. 5431 if (Method->isStatic() == IsMember) 5432 continue; 5433 5434 // If we have explicit template arguments, skip non-templates. 5435 if (OvlExpr->hasExplicitTemplateArgs()) 5436 continue; 5437 } else if (IsMember) 5438 continue; 5439 5440 if (FunctionDecl *FunDecl = dyn_cast<FunctionDecl>(Fn)) { 5441 QualType ResultTy; 5442 if (Context.hasSameUnqualifiedType(FunctionType, FunDecl->getType()) || 5443 IsNoReturnConversion(Context, FunDecl->getType(), FunctionType, 5444 ResultTy)) { 5445 Matches.push_back(std::make_pair(I.getPair(), 5446 cast<FunctionDecl>(FunDecl->getCanonicalDecl()))); 5447 FoundNonTemplateFunction = true; 5448 } 5449 } 5450 } 5451 5452 // If there were 0 or 1 matches, we're done. 5453 if (Matches.empty()) { 5454 if (Complain) { 5455 Diag(From->getLocStart(), diag::err_addr_ovl_no_viable) 5456 << OvlExpr->getName() << FunctionType; 5457 for (UnresolvedSetIterator I = OvlExpr->decls_begin(), 5458 E = OvlExpr->decls_end(); 5459 I != E; ++I) 5460 if (FunctionDecl *F = dyn_cast<FunctionDecl>((*I)->getUnderlyingDecl())) 5461 NoteOverloadCandidate(F); 5462 } 5463 5464 return 0; 5465 } else if (Matches.size() == 1) { 5466 FunctionDecl *Result = Matches[0].second; 5467 FoundResult = Matches[0].first; 5468 MarkDeclarationReferenced(From->getLocStart(), Result); 5469 if (Complain) 5470 CheckAddressOfMemberAccess(OvlExpr, Matches[0].first); 5471 return Result; 5472 } 5473 5474 // C++ [over.over]p4: 5475 // If more than one function is selected, [...] 5476 if (!FoundNonTemplateFunction) { 5477 // [...] and any given function template specialization F1 is 5478 // eliminated if the set contains a second function template 5479 // specialization whose function template is more specialized 5480 // than the function template of F1 according to the partial 5481 // ordering rules of 14.5.5.2. 5482 5483 // The algorithm specified above is quadratic. We instead use a 5484 // two-pass algorithm (similar to the one used to identify the 5485 // best viable function in an overload set) that identifies the 5486 // best function template (if it exists). 5487 5488 UnresolvedSet<4> MatchesCopy; // TODO: avoid! 5489 for (unsigned I = 0, E = Matches.size(); I != E; ++I) 5490 MatchesCopy.addDecl(Matches[I].second, Matches[I].first.getAccess()); 5491 5492 UnresolvedSetIterator Result = 5493 getMostSpecialized(MatchesCopy.begin(), MatchesCopy.end(), 5494 TPOC_Other, From->getLocStart(), 5495 PDiag(), 5496 PDiag(diag::err_addr_ovl_ambiguous) 5497 << Matches[0].second->getDeclName(), 5498 PDiag(diag::note_ovl_candidate) 5499 << (unsigned) oc_function_template); 5500 assert(Result != MatchesCopy.end() && "no most-specialized template"); 5501 MarkDeclarationReferenced(From->getLocStart(), *Result); 5502 FoundResult = Matches[Result - MatchesCopy.begin()].first; 5503 if (Complain) 5504 CheckUnresolvedAccess(*this, OvlExpr, FoundResult); 5505 return cast<FunctionDecl>(*Result); 5506 } 5507 5508 // [...] any function template specializations in the set are 5509 // eliminated if the set also contains a non-template function, [...] 5510 for (unsigned I = 0, N = Matches.size(); I != N; ) { 5511 if (Matches[I].second->getPrimaryTemplate() == 0) 5512 ++I; 5513 else { 5514 Matches[I] = Matches[--N]; 5515 Matches.set_size(N); 5516 } 5517 } 5518 5519 // [...] After such eliminations, if any, there shall remain exactly one 5520 // selected function. 5521 if (Matches.size() == 1) { 5522 MarkDeclarationReferenced(From->getLocStart(), Matches[0].second); 5523 FoundResult = Matches[0].first; 5524 if (Complain) 5525 CheckUnresolvedAccess(*this, OvlExpr, Matches[0].first); 5526 return cast<FunctionDecl>(Matches[0].second); 5527 } 5528 5529 // FIXME: We should probably return the same thing that BestViableFunction 5530 // returns (even if we issue the diagnostics here). 5531 Diag(From->getLocStart(), diag::err_addr_ovl_ambiguous) 5532 << Matches[0].second->getDeclName(); 5533 for (unsigned I = 0, E = Matches.size(); I != E; ++I) 5534 NoteOverloadCandidate(Matches[I].second); 5535 return 0; 5536} 5537 5538/// \brief Given an expression that refers to an overloaded function, try to 5539/// resolve that overloaded function expression down to a single function. 5540/// 5541/// This routine can only resolve template-ids that refer to a single function 5542/// template, where that template-id refers to a single template whose template 5543/// arguments are either provided by the template-id or have defaults, 5544/// as described in C++0x [temp.arg.explicit]p3. 5545FunctionDecl *Sema::ResolveSingleFunctionTemplateSpecialization(Expr *From) { 5546 // C++ [over.over]p1: 5547 // [...] [Note: any redundant set of parentheses surrounding the 5548 // overloaded function name is ignored (5.1). ] 5549 // C++ [over.over]p1: 5550 // [...] The overloaded function name can be preceded by the & 5551 // operator. 5552 5553 if (From->getType() != Context.OverloadTy) 5554 return 0; 5555 5556 OverloadExpr *OvlExpr = OverloadExpr::find(From).getPointer(); 5557 5558 // If we didn't actually find any template-ids, we're done. 5559 if (!OvlExpr->hasExplicitTemplateArgs()) 5560 return 0; 5561 5562 TemplateArgumentListInfo ExplicitTemplateArgs; 5563 OvlExpr->getExplicitTemplateArgs().copyInto(ExplicitTemplateArgs); 5564 5565 // Look through all of the overloaded functions, searching for one 5566 // whose type matches exactly. 5567 FunctionDecl *Matched = 0; 5568 for (UnresolvedSetIterator I = OvlExpr->decls_begin(), 5569 E = OvlExpr->decls_end(); I != E; ++I) { 5570 // C++0x [temp.arg.explicit]p3: 5571 // [...] In contexts where deduction is done and fails, or in contexts 5572 // where deduction is not done, if a template argument list is 5573 // specified and it, along with any default template arguments, 5574 // identifies a single function template specialization, then the 5575 // template-id is an lvalue for the function template specialization. 5576 FunctionTemplateDecl *FunctionTemplate = cast<FunctionTemplateDecl>(*I); 5577 5578 // C++ [over.over]p2: 5579 // If the name is a function template, template argument deduction is 5580 // done (14.8.2.2), and if the argument deduction succeeds, the 5581 // resulting template argument list is used to generate a single 5582 // function template specialization, which is added to the set of 5583 // overloaded functions considered. 5584 FunctionDecl *Specialization = 0; 5585 TemplateDeductionInfo Info(Context, OvlExpr->getNameLoc()); 5586 if (TemplateDeductionResult Result 5587 = DeduceTemplateArguments(FunctionTemplate, &ExplicitTemplateArgs, 5588 Specialization, Info)) { 5589 // FIXME: make a note of the failed deduction for diagnostics. 5590 (void)Result; 5591 continue; 5592 } 5593 5594 // Multiple matches; we can't resolve to a single declaration. 5595 if (Matched) 5596 return 0; 5597 5598 Matched = Specialization; 5599 } 5600 5601 return Matched; 5602} 5603 5604/// \brief Add a single candidate to the overload set. 5605static void AddOverloadedCallCandidate(Sema &S, 5606 DeclAccessPair FoundDecl, 5607 const TemplateArgumentListInfo *ExplicitTemplateArgs, 5608 Expr **Args, unsigned NumArgs, 5609 OverloadCandidateSet &CandidateSet, 5610 bool PartialOverloading) { 5611 NamedDecl *Callee = FoundDecl.getDecl(); 5612 if (isa<UsingShadowDecl>(Callee)) 5613 Callee = cast<UsingShadowDecl>(Callee)->getTargetDecl(); 5614 5615 if (FunctionDecl *Func = dyn_cast<FunctionDecl>(Callee)) { 5616 assert(!ExplicitTemplateArgs && "Explicit template arguments?"); 5617 S.AddOverloadCandidate(Func, FoundDecl, Args, NumArgs, CandidateSet, 5618 false, PartialOverloading); 5619 return; 5620 } 5621 5622 if (FunctionTemplateDecl *FuncTemplate 5623 = dyn_cast<FunctionTemplateDecl>(Callee)) { 5624 S.AddTemplateOverloadCandidate(FuncTemplate, FoundDecl, 5625 ExplicitTemplateArgs, 5626 Args, NumArgs, CandidateSet); 5627 return; 5628 } 5629 5630 assert(false && "unhandled case in overloaded call candidate"); 5631 5632 // do nothing? 5633} 5634 5635/// \brief Add the overload candidates named by callee and/or found by argument 5636/// dependent lookup to the given overload set. 5637void Sema::AddOverloadedCallCandidates(UnresolvedLookupExpr *ULE, 5638 Expr **Args, unsigned NumArgs, 5639 OverloadCandidateSet &CandidateSet, 5640 bool PartialOverloading) { 5641 5642#ifndef NDEBUG 5643 // Verify that ArgumentDependentLookup is consistent with the rules 5644 // in C++0x [basic.lookup.argdep]p3: 5645 // 5646 // Let X be the lookup set produced by unqualified lookup (3.4.1) 5647 // and let Y be the lookup set produced by argument dependent 5648 // lookup (defined as follows). If X contains 5649 // 5650 // -- a declaration of a class member, or 5651 // 5652 // -- a block-scope function declaration that is not a 5653 // using-declaration, or 5654 // 5655 // -- a declaration that is neither a function or a function 5656 // template 5657 // 5658 // then Y is empty. 5659 5660 if (ULE->requiresADL()) { 5661 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(), 5662 E = ULE->decls_end(); I != E; ++I) { 5663 assert(!(*I)->getDeclContext()->isRecord()); 5664 assert(isa<UsingShadowDecl>(*I) || 5665 !(*I)->getDeclContext()->isFunctionOrMethod()); 5666 assert((*I)->getUnderlyingDecl()->isFunctionOrFunctionTemplate()); 5667 } 5668 } 5669#endif 5670 5671 // It would be nice to avoid this copy. 5672 TemplateArgumentListInfo TABuffer; 5673 const TemplateArgumentListInfo *ExplicitTemplateArgs = 0; 5674 if (ULE->hasExplicitTemplateArgs()) { 5675 ULE->copyTemplateArgumentsInto(TABuffer); 5676 ExplicitTemplateArgs = &TABuffer; 5677 } 5678 5679 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(), 5680 E = ULE->decls_end(); I != E; ++I) 5681 AddOverloadedCallCandidate(*this, I.getPair(), ExplicitTemplateArgs, 5682 Args, NumArgs, CandidateSet, 5683 PartialOverloading); 5684 5685 if (ULE->requiresADL()) 5686 AddArgumentDependentLookupCandidates(ULE->getName(), /*Operator*/ false, 5687 Args, NumArgs, 5688 ExplicitTemplateArgs, 5689 CandidateSet, 5690 PartialOverloading); 5691} 5692 5693static Sema::OwningExprResult Destroy(Sema &SemaRef, Expr *Fn, 5694 Expr **Args, unsigned NumArgs) { 5695 Fn->Destroy(SemaRef.Context); 5696 for (unsigned Arg = 0; Arg < NumArgs; ++Arg) 5697 Args[Arg]->Destroy(SemaRef.Context); 5698 return SemaRef.ExprError(); 5699} 5700 5701/// Attempts to recover from a call where no functions were found. 5702/// 5703/// Returns true if new candidates were found. 5704static Sema::OwningExprResult 5705BuildRecoveryCallExpr(Sema &SemaRef, Scope *S, Expr *Fn, 5706 UnresolvedLookupExpr *ULE, 5707 SourceLocation LParenLoc, 5708 Expr **Args, unsigned NumArgs, 5709 SourceLocation *CommaLocs, 5710 SourceLocation RParenLoc) { 5711 5712 CXXScopeSpec SS; 5713 if (ULE->getQualifier()) { 5714 SS.setScopeRep(ULE->getQualifier()); 5715 SS.setRange(ULE->getQualifierRange()); 5716 } 5717 5718 TemplateArgumentListInfo TABuffer; 5719 const TemplateArgumentListInfo *ExplicitTemplateArgs = 0; 5720 if (ULE->hasExplicitTemplateArgs()) { 5721 ULE->copyTemplateArgumentsInto(TABuffer); 5722 ExplicitTemplateArgs = &TABuffer; 5723 } 5724 5725 LookupResult R(SemaRef, ULE->getName(), ULE->getNameLoc(), 5726 Sema::LookupOrdinaryName); 5727 if (SemaRef.DiagnoseEmptyLookup(S, SS, R)) 5728 return Destroy(SemaRef, Fn, Args, NumArgs); 5729 5730 assert(!R.empty() && "lookup results empty despite recovery"); 5731 5732 // Build an implicit member call if appropriate. Just drop the 5733 // casts and such from the call, we don't really care. 5734 Sema::OwningExprResult NewFn = SemaRef.ExprError(); 5735 if ((*R.begin())->isCXXClassMember()) 5736 NewFn = SemaRef.BuildPossibleImplicitMemberExpr(SS, R, ExplicitTemplateArgs); 5737 else if (ExplicitTemplateArgs) 5738 NewFn = SemaRef.BuildTemplateIdExpr(SS, R, false, *ExplicitTemplateArgs); 5739 else 5740 NewFn = SemaRef.BuildDeclarationNameExpr(SS, R, false); 5741 5742 if (NewFn.isInvalid()) 5743 return Destroy(SemaRef, Fn, Args, NumArgs); 5744 5745 Fn->Destroy(SemaRef.Context); 5746 5747 // This shouldn't cause an infinite loop because we're giving it 5748 // an expression with non-empty lookup results, which should never 5749 // end up here. 5750 return SemaRef.ActOnCallExpr(/*Scope*/ 0, move(NewFn), LParenLoc, 5751 Sema::MultiExprArg(SemaRef, (void**) Args, NumArgs), 5752 CommaLocs, RParenLoc); 5753} 5754 5755/// ResolveOverloadedCallFn - Given the call expression that calls Fn 5756/// (which eventually refers to the declaration Func) and the call 5757/// arguments Args/NumArgs, attempt to resolve the function call down 5758/// to a specific function. If overload resolution succeeds, returns 5759/// the function declaration produced by overload 5760/// resolution. Otherwise, emits diagnostics, deletes all of the 5761/// arguments and Fn, and returns NULL. 5762Sema::OwningExprResult 5763Sema::BuildOverloadedCallExpr(Scope *S, Expr *Fn, UnresolvedLookupExpr *ULE, 5764 SourceLocation LParenLoc, 5765 Expr **Args, unsigned NumArgs, 5766 SourceLocation *CommaLocs, 5767 SourceLocation RParenLoc) { 5768#ifndef NDEBUG 5769 if (ULE->requiresADL()) { 5770 // To do ADL, we must have found an unqualified name. 5771 assert(!ULE->getQualifier() && "qualified name with ADL"); 5772 5773 // We don't perform ADL for implicit declarations of builtins. 5774 // Verify that this was correctly set up. 5775 FunctionDecl *F; 5776 if (ULE->decls_begin() + 1 == ULE->decls_end() && 5777 (F = dyn_cast<FunctionDecl>(*ULE->decls_begin())) && 5778 F->getBuiltinID() && F->isImplicit()) 5779 assert(0 && "performing ADL for builtin"); 5780 5781 // We don't perform ADL in C. 5782 assert(getLangOptions().CPlusPlus && "ADL enabled in C"); 5783 } 5784#endif 5785 5786 OverloadCandidateSet CandidateSet(Fn->getExprLoc()); 5787 5788 // Add the functions denoted by the callee to the set of candidate 5789 // functions, including those from argument-dependent lookup. 5790 AddOverloadedCallCandidates(ULE, Args, NumArgs, CandidateSet); 5791 5792 // If we found nothing, try to recover. 5793 // AddRecoveryCallCandidates diagnoses the error itself, so we just 5794 // bailout out if it fails. 5795 if (CandidateSet.empty()) 5796 return BuildRecoveryCallExpr(*this, S, Fn, ULE, LParenLoc, Args, NumArgs, 5797 CommaLocs, RParenLoc); 5798 5799 OverloadCandidateSet::iterator Best; 5800 switch (BestViableFunction(CandidateSet, Fn->getLocStart(), Best)) { 5801 case OR_Success: { 5802 FunctionDecl *FDecl = Best->Function; 5803 CheckUnresolvedLookupAccess(ULE, Best->FoundDecl); 5804 Fn = FixOverloadedFunctionReference(Fn, Best->FoundDecl, FDecl); 5805 return BuildResolvedCallExpr(Fn, FDecl, LParenLoc, Args, NumArgs, RParenLoc); 5806 } 5807 5808 case OR_No_Viable_Function: 5809 Diag(Fn->getSourceRange().getBegin(), 5810 diag::err_ovl_no_viable_function_in_call) 5811 << ULE->getName() << Fn->getSourceRange(); 5812 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 5813 break; 5814 5815 case OR_Ambiguous: 5816 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_ambiguous_call) 5817 << ULE->getName() << Fn->getSourceRange(); 5818 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, NumArgs); 5819 break; 5820 5821 case OR_Deleted: 5822 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_deleted_call) 5823 << Best->Function->isDeleted() 5824 << ULE->getName() 5825 << Fn->getSourceRange(); 5826 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 5827 break; 5828 } 5829 5830 // Overload resolution failed. Destroy all of the subexpressions and 5831 // return NULL. 5832 Fn->Destroy(Context); 5833 for (unsigned Arg = 0; Arg < NumArgs; ++Arg) 5834 Args[Arg]->Destroy(Context); 5835 return ExprError(); 5836} 5837 5838static bool IsOverloaded(const UnresolvedSetImpl &Functions) { 5839 return Functions.size() > 1 || 5840 (Functions.size() == 1 && isa<FunctionTemplateDecl>(*Functions.begin())); 5841} 5842 5843/// \brief Create a unary operation that may resolve to an overloaded 5844/// operator. 5845/// 5846/// \param OpLoc The location of the operator itself (e.g., '*'). 5847/// 5848/// \param OpcIn The UnaryOperator::Opcode that describes this 5849/// operator. 5850/// 5851/// \param Functions The set of non-member functions that will be 5852/// considered by overload resolution. The caller needs to build this 5853/// set based on the context using, e.g., 5854/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 5855/// set should not contain any member functions; those will be added 5856/// by CreateOverloadedUnaryOp(). 5857/// 5858/// \param input The input argument. 5859Sema::OwningExprResult 5860Sema::CreateOverloadedUnaryOp(SourceLocation OpLoc, unsigned OpcIn, 5861 const UnresolvedSetImpl &Fns, 5862 ExprArg input) { 5863 UnaryOperator::Opcode Opc = static_cast<UnaryOperator::Opcode>(OpcIn); 5864 Expr *Input = (Expr *)input.get(); 5865 5866 OverloadedOperatorKind Op = UnaryOperator::getOverloadedOperator(Opc); 5867 assert(Op != OO_None && "Invalid opcode for overloaded unary operator"); 5868 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 5869 5870 Expr *Args[2] = { Input, 0 }; 5871 unsigned NumArgs = 1; 5872 5873 // For post-increment and post-decrement, add the implicit '0' as 5874 // the second argument, so that we know this is a post-increment or 5875 // post-decrement. 5876 if (Opc == UnaryOperator::PostInc || Opc == UnaryOperator::PostDec) { 5877 llvm::APSInt Zero(Context.getTypeSize(Context.IntTy), false); 5878 Args[1] = new (Context) IntegerLiteral(Zero, Context.IntTy, 5879 SourceLocation()); 5880 NumArgs = 2; 5881 } 5882 5883 if (Input->isTypeDependent()) { 5884 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 5885 UnresolvedLookupExpr *Fn 5886 = UnresolvedLookupExpr::Create(Context, /*Dependent*/ true, NamingClass, 5887 0, SourceRange(), OpName, OpLoc, 5888 /*ADL*/ true, IsOverloaded(Fns)); 5889 Fn->addDecls(Fns.begin(), Fns.end()); 5890 5891 input.release(); 5892 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 5893 &Args[0], NumArgs, 5894 Context.DependentTy, 5895 OpLoc)); 5896 } 5897 5898 // Build an empty overload set. 5899 OverloadCandidateSet CandidateSet(OpLoc); 5900 5901 // Add the candidates from the given function set. 5902 AddFunctionCandidates(Fns, &Args[0], NumArgs, CandidateSet, false); 5903 5904 // Add operator candidates that are member functions. 5905 AddMemberOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 5906 5907 // Add candidates from ADL. 5908 AddArgumentDependentLookupCandidates(OpName, /*Operator*/ true, 5909 Args, NumArgs, 5910 /*ExplicitTemplateArgs*/ 0, 5911 CandidateSet); 5912 5913 // Add builtin operator candidates. 5914 AddBuiltinOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 5915 5916 // Perform overload resolution. 5917 OverloadCandidateSet::iterator Best; 5918 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 5919 case OR_Success: { 5920 // We found a built-in operator or an overloaded operator. 5921 FunctionDecl *FnDecl = Best->Function; 5922 5923 if (FnDecl) { 5924 // We matched an overloaded operator. Build a call to that 5925 // operator. 5926 5927 // Convert the arguments. 5928 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 5929 CheckMemberOperatorAccess(OpLoc, Args[0], 0, Best->FoundDecl); 5930 5931 if (PerformObjectArgumentInitialization(Input, /*Qualifier=*/0, 5932 Best->FoundDecl, Method)) 5933 return ExprError(); 5934 } else { 5935 // Convert the arguments. 5936 OwningExprResult InputInit 5937 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 5938 FnDecl->getParamDecl(0)), 5939 SourceLocation(), 5940 move(input)); 5941 if (InputInit.isInvalid()) 5942 return ExprError(); 5943 5944 input = move(InputInit); 5945 Input = (Expr *)input.get(); 5946 } 5947 5948 // Determine the result type 5949 QualType ResultTy = FnDecl->getResultType().getNonReferenceType(); 5950 5951 // Build the actual expression node. 5952 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 5953 SourceLocation()); 5954 UsualUnaryConversions(FnExpr); 5955 5956 input.release(); 5957 Args[0] = Input; 5958 ExprOwningPtr<CallExpr> TheCall(this, 5959 new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 5960 Args, NumArgs, ResultTy, OpLoc)); 5961 5962 if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall.get(), 5963 FnDecl)) 5964 return ExprError(); 5965 5966 return MaybeBindToTemporary(TheCall.release()); 5967 } else { 5968 // We matched a built-in operator. Convert the arguments, then 5969 // break out so that we will build the appropriate built-in 5970 // operator node. 5971 if (PerformImplicitConversion(Input, Best->BuiltinTypes.ParamTypes[0], 5972 Best->Conversions[0], AA_Passing)) 5973 return ExprError(); 5974 5975 break; 5976 } 5977 } 5978 5979 case OR_No_Viable_Function: 5980 // No viable function; fall through to handling this as a 5981 // built-in operator, which will produce an error message for us. 5982 break; 5983 5984 case OR_Ambiguous: 5985 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 5986 << UnaryOperator::getOpcodeStr(Opc) 5987 << Input->getSourceRange(); 5988 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, NumArgs, 5989 UnaryOperator::getOpcodeStr(Opc), OpLoc); 5990 return ExprError(); 5991 5992 case OR_Deleted: 5993 Diag(OpLoc, diag::err_ovl_deleted_oper) 5994 << Best->Function->isDeleted() 5995 << UnaryOperator::getOpcodeStr(Opc) 5996 << Input->getSourceRange(); 5997 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 5998 return ExprError(); 5999 } 6000 6001 // Either we found no viable overloaded operator or we matched a 6002 // built-in operator. In either case, fall through to trying to 6003 // build a built-in operation. 6004 input.release(); 6005 return CreateBuiltinUnaryOp(OpLoc, Opc, Owned(Input)); 6006} 6007 6008/// \brief Create a binary operation that may resolve to an overloaded 6009/// operator. 6010/// 6011/// \param OpLoc The location of the operator itself (e.g., '+'). 6012/// 6013/// \param OpcIn The BinaryOperator::Opcode that describes this 6014/// operator. 6015/// 6016/// \param Functions The set of non-member functions that will be 6017/// considered by overload resolution. The caller needs to build this 6018/// set based on the context using, e.g., 6019/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 6020/// set should not contain any member functions; those will be added 6021/// by CreateOverloadedBinOp(). 6022/// 6023/// \param LHS Left-hand argument. 6024/// \param RHS Right-hand argument. 6025Sema::OwningExprResult 6026Sema::CreateOverloadedBinOp(SourceLocation OpLoc, 6027 unsigned OpcIn, 6028 const UnresolvedSetImpl &Fns, 6029 Expr *LHS, Expr *RHS) { 6030 Expr *Args[2] = { LHS, RHS }; 6031 LHS=RHS=0; //Please use only Args instead of LHS/RHS couple 6032 6033 BinaryOperator::Opcode Opc = static_cast<BinaryOperator::Opcode>(OpcIn); 6034 OverloadedOperatorKind Op = BinaryOperator::getOverloadedOperator(Opc); 6035 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 6036 6037 // If either side is type-dependent, create an appropriate dependent 6038 // expression. 6039 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 6040 if (Fns.empty()) { 6041 // If there are no functions to store, just build a dependent 6042 // BinaryOperator or CompoundAssignment. 6043 if (Opc <= BinaryOperator::Assign || Opc > BinaryOperator::OrAssign) 6044 return Owned(new (Context) BinaryOperator(Args[0], Args[1], Opc, 6045 Context.DependentTy, OpLoc)); 6046 6047 return Owned(new (Context) CompoundAssignOperator(Args[0], Args[1], Opc, 6048 Context.DependentTy, 6049 Context.DependentTy, 6050 Context.DependentTy, 6051 OpLoc)); 6052 } 6053 6054 // FIXME: save results of ADL from here? 6055 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 6056 UnresolvedLookupExpr *Fn 6057 = UnresolvedLookupExpr::Create(Context, /*Dependent*/ true, NamingClass, 6058 0, SourceRange(), OpName, OpLoc, 6059 /*ADL*/ true, IsOverloaded(Fns)); 6060 6061 Fn->addDecls(Fns.begin(), Fns.end()); 6062 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 6063 Args, 2, 6064 Context.DependentTy, 6065 OpLoc)); 6066 } 6067 6068 // If this is the .* operator, which is not overloadable, just 6069 // create a built-in binary operator. 6070 if (Opc == BinaryOperator::PtrMemD) 6071 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 6072 6073 // If this is the assignment operator, we only perform overload resolution 6074 // if the left-hand side is a class or enumeration type. This is actually 6075 // a hack. The standard requires that we do overload resolution between the 6076 // various built-in candidates, but as DR507 points out, this can lead to 6077 // problems. So we do it this way, which pretty much follows what GCC does. 6078 // Note that we go the traditional code path for compound assignment forms. 6079 if (Opc==BinaryOperator::Assign && !Args[0]->getType()->isOverloadableType()) 6080 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 6081 6082 // Build an empty overload set. 6083 OverloadCandidateSet CandidateSet(OpLoc); 6084 6085 // Add the candidates from the given function set. 6086 AddFunctionCandidates(Fns, Args, 2, CandidateSet, false); 6087 6088 // Add operator candidates that are member functions. 6089 AddMemberOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 6090 6091 // Add candidates from ADL. 6092 AddArgumentDependentLookupCandidates(OpName, /*Operator*/ true, 6093 Args, 2, 6094 /*ExplicitTemplateArgs*/ 0, 6095 CandidateSet); 6096 6097 // Add builtin operator candidates. 6098 AddBuiltinOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 6099 6100 // Perform overload resolution. 6101 OverloadCandidateSet::iterator Best; 6102 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 6103 case OR_Success: { 6104 // We found a built-in operator or an overloaded operator. 6105 FunctionDecl *FnDecl = Best->Function; 6106 6107 if (FnDecl) { 6108 // We matched an overloaded operator. Build a call to that 6109 // operator. 6110 6111 // Convert the arguments. 6112 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 6113 // Best->Access is only meaningful for class members. 6114 CheckMemberOperatorAccess(OpLoc, Args[0], Args[1], Best->FoundDecl); 6115 6116 OwningExprResult Arg1 6117 = PerformCopyInitialization( 6118 InitializedEntity::InitializeParameter( 6119 FnDecl->getParamDecl(0)), 6120 SourceLocation(), 6121 Owned(Args[1])); 6122 if (Arg1.isInvalid()) 6123 return ExprError(); 6124 6125 if (PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/0, 6126 Best->FoundDecl, Method)) 6127 return ExprError(); 6128 6129 Args[1] = RHS = Arg1.takeAs<Expr>(); 6130 } else { 6131 // Convert the arguments. 6132 OwningExprResult Arg0 6133 = PerformCopyInitialization( 6134 InitializedEntity::InitializeParameter( 6135 FnDecl->getParamDecl(0)), 6136 SourceLocation(), 6137 Owned(Args[0])); 6138 if (Arg0.isInvalid()) 6139 return ExprError(); 6140 6141 OwningExprResult Arg1 6142 = PerformCopyInitialization( 6143 InitializedEntity::InitializeParameter( 6144 FnDecl->getParamDecl(1)), 6145 SourceLocation(), 6146 Owned(Args[1])); 6147 if (Arg1.isInvalid()) 6148 return ExprError(); 6149 Args[0] = LHS = Arg0.takeAs<Expr>(); 6150 Args[1] = RHS = Arg1.takeAs<Expr>(); 6151 } 6152 6153 // Determine the result type 6154 QualType ResultTy 6155 = FnDecl->getType()->getAs<FunctionType>()->getResultType(); 6156 ResultTy = ResultTy.getNonReferenceType(); 6157 6158 // Build the actual expression node. 6159 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 6160 OpLoc); 6161 UsualUnaryConversions(FnExpr); 6162 6163 ExprOwningPtr<CXXOperatorCallExpr> 6164 TheCall(this, new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 6165 Args, 2, ResultTy, 6166 OpLoc)); 6167 6168 if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall.get(), 6169 FnDecl)) 6170 return ExprError(); 6171 6172 return MaybeBindToTemporary(TheCall.release()); 6173 } else { 6174 // We matched a built-in operator. Convert the arguments, then 6175 // break out so that we will build the appropriate built-in 6176 // operator node. 6177 if (PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 6178 Best->Conversions[0], AA_Passing) || 6179 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 6180 Best->Conversions[1], AA_Passing)) 6181 return ExprError(); 6182 6183 break; 6184 } 6185 } 6186 6187 case OR_No_Viable_Function: { 6188 // C++ [over.match.oper]p9: 6189 // If the operator is the operator , [...] and there are no 6190 // viable functions, then the operator is assumed to be the 6191 // built-in operator and interpreted according to clause 5. 6192 if (Opc == BinaryOperator::Comma) 6193 break; 6194 6195 // For class as left operand for assignment or compound assigment operator 6196 // do not fall through to handling in built-in, but report that no overloaded 6197 // assignment operator found 6198 OwningExprResult Result = ExprError(); 6199 if (Args[0]->getType()->isRecordType() && 6200 Opc >= BinaryOperator::Assign && Opc <= BinaryOperator::OrAssign) { 6201 Diag(OpLoc, diag::err_ovl_no_viable_oper) 6202 << BinaryOperator::getOpcodeStr(Opc) 6203 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 6204 } else { 6205 // No viable function; try to create a built-in operation, which will 6206 // produce an error. Then, show the non-viable candidates. 6207 Result = CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 6208 } 6209 assert(Result.isInvalid() && 6210 "C++ binary operator overloading is missing candidates!"); 6211 if (Result.isInvalid()) 6212 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2, 6213 BinaryOperator::getOpcodeStr(Opc), OpLoc); 6214 return move(Result); 6215 } 6216 6217 case OR_Ambiguous: 6218 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 6219 << BinaryOperator::getOpcodeStr(Opc) 6220 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 6221 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, 2, 6222 BinaryOperator::getOpcodeStr(Opc), OpLoc); 6223 return ExprError(); 6224 6225 case OR_Deleted: 6226 Diag(OpLoc, diag::err_ovl_deleted_oper) 6227 << Best->Function->isDeleted() 6228 << BinaryOperator::getOpcodeStr(Opc) 6229 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 6230 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2); 6231 return ExprError(); 6232 } 6233 6234 // We matched a built-in operator; build it. 6235 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 6236} 6237 6238Action::OwningExprResult 6239Sema::CreateOverloadedArraySubscriptExpr(SourceLocation LLoc, 6240 SourceLocation RLoc, 6241 ExprArg Base, ExprArg Idx) { 6242 Expr *Args[2] = { static_cast<Expr*>(Base.get()), 6243 static_cast<Expr*>(Idx.get()) }; 6244 DeclarationName OpName = 6245 Context.DeclarationNames.getCXXOperatorName(OO_Subscript); 6246 6247 // If either side is type-dependent, create an appropriate dependent 6248 // expression. 6249 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 6250 6251 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 6252 UnresolvedLookupExpr *Fn 6253 = UnresolvedLookupExpr::Create(Context, /*Dependent*/ true, NamingClass, 6254 0, SourceRange(), OpName, LLoc, 6255 /*ADL*/ true, /*Overloaded*/ false); 6256 // Can't add any actual overloads yet 6257 6258 Base.release(); 6259 Idx.release(); 6260 return Owned(new (Context) CXXOperatorCallExpr(Context, OO_Subscript, Fn, 6261 Args, 2, 6262 Context.DependentTy, 6263 RLoc)); 6264 } 6265 6266 // Build an empty overload set. 6267 OverloadCandidateSet CandidateSet(LLoc); 6268 6269 // Subscript can only be overloaded as a member function. 6270 6271 // Add operator candidates that are member functions. 6272 AddMemberOperatorCandidates(OO_Subscript, LLoc, Args, 2, CandidateSet); 6273 6274 // Add builtin operator candidates. 6275 AddBuiltinOperatorCandidates(OO_Subscript, LLoc, Args, 2, CandidateSet); 6276 6277 // Perform overload resolution. 6278 OverloadCandidateSet::iterator Best; 6279 switch (BestViableFunction(CandidateSet, LLoc, Best)) { 6280 case OR_Success: { 6281 // We found a built-in operator or an overloaded operator. 6282 FunctionDecl *FnDecl = Best->Function; 6283 6284 if (FnDecl) { 6285 // We matched an overloaded operator. Build a call to that 6286 // operator. 6287 6288 CheckMemberOperatorAccess(LLoc, Args[0], Args[1], Best->FoundDecl); 6289 6290 // Convert the arguments. 6291 CXXMethodDecl *Method = cast<CXXMethodDecl>(FnDecl); 6292 if (PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/0, 6293 Best->FoundDecl, Method)) 6294 return ExprError(); 6295 6296 // Convert the arguments. 6297 OwningExprResult InputInit 6298 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 6299 FnDecl->getParamDecl(0)), 6300 SourceLocation(), 6301 Owned(Args[1])); 6302 if (InputInit.isInvalid()) 6303 return ExprError(); 6304 6305 Args[1] = InputInit.takeAs<Expr>(); 6306 6307 // Determine the result type 6308 QualType ResultTy 6309 = FnDecl->getType()->getAs<FunctionType>()->getResultType(); 6310 ResultTy = ResultTy.getNonReferenceType(); 6311 6312 // Build the actual expression node. 6313 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 6314 LLoc); 6315 UsualUnaryConversions(FnExpr); 6316 6317 Base.release(); 6318 Idx.release(); 6319 ExprOwningPtr<CXXOperatorCallExpr> 6320 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Subscript, 6321 FnExpr, Args, 2, 6322 ResultTy, RLoc)); 6323 6324 if (CheckCallReturnType(FnDecl->getResultType(), LLoc, TheCall.get(), 6325 FnDecl)) 6326 return ExprError(); 6327 6328 return MaybeBindToTemporary(TheCall.release()); 6329 } else { 6330 // We matched a built-in operator. Convert the arguments, then 6331 // break out so that we will build the appropriate built-in 6332 // operator node. 6333 if (PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 6334 Best->Conversions[0], AA_Passing) || 6335 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 6336 Best->Conversions[1], AA_Passing)) 6337 return ExprError(); 6338 6339 break; 6340 } 6341 } 6342 6343 case OR_No_Viable_Function: { 6344 if (CandidateSet.empty()) 6345 Diag(LLoc, diag::err_ovl_no_oper) 6346 << Args[0]->getType() << /*subscript*/ 0 6347 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 6348 else 6349 Diag(LLoc, diag::err_ovl_no_viable_subscript) 6350 << Args[0]->getType() 6351 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 6352 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2, 6353 "[]", LLoc); 6354 return ExprError(); 6355 } 6356 6357 case OR_Ambiguous: 6358 Diag(LLoc, diag::err_ovl_ambiguous_oper) 6359 << "[]" << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 6360 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, 2, 6361 "[]", LLoc); 6362 return ExprError(); 6363 6364 case OR_Deleted: 6365 Diag(LLoc, diag::err_ovl_deleted_oper) 6366 << Best->Function->isDeleted() << "[]" 6367 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 6368 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2, 6369 "[]", LLoc); 6370 return ExprError(); 6371 } 6372 6373 // We matched a built-in operator; build it. 6374 Base.release(); 6375 Idx.release(); 6376 return CreateBuiltinArraySubscriptExpr(Owned(Args[0]), LLoc, 6377 Owned(Args[1]), RLoc); 6378} 6379 6380/// BuildCallToMemberFunction - Build a call to a member 6381/// function. MemExpr is the expression that refers to the member 6382/// function (and includes the object parameter), Args/NumArgs are the 6383/// arguments to the function call (not including the object 6384/// parameter). The caller needs to validate that the member 6385/// expression refers to a member function or an overloaded member 6386/// function. 6387Sema::OwningExprResult 6388Sema::BuildCallToMemberFunction(Scope *S, Expr *MemExprE, 6389 SourceLocation LParenLoc, Expr **Args, 6390 unsigned NumArgs, SourceLocation *CommaLocs, 6391 SourceLocation RParenLoc) { 6392 // Dig out the member expression. This holds both the object 6393 // argument and the member function we're referring to. 6394 Expr *NakedMemExpr = MemExprE->IgnoreParens(); 6395 6396 MemberExpr *MemExpr; 6397 CXXMethodDecl *Method = 0; 6398 DeclAccessPair FoundDecl = DeclAccessPair::make(0, AS_public); 6399 NestedNameSpecifier *Qualifier = 0; 6400 if (isa<MemberExpr>(NakedMemExpr)) { 6401 MemExpr = cast<MemberExpr>(NakedMemExpr); 6402 Method = cast<CXXMethodDecl>(MemExpr->getMemberDecl()); 6403 FoundDecl = MemExpr->getFoundDecl(); 6404 Qualifier = MemExpr->getQualifier(); 6405 } else { 6406 UnresolvedMemberExpr *UnresExpr = cast<UnresolvedMemberExpr>(NakedMemExpr); 6407 Qualifier = UnresExpr->getQualifier(); 6408 6409 QualType ObjectType = UnresExpr->getBaseType(); 6410 6411 // Add overload candidates 6412 OverloadCandidateSet CandidateSet(UnresExpr->getMemberLoc()); 6413 6414 // FIXME: avoid copy. 6415 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 6416 if (UnresExpr->hasExplicitTemplateArgs()) { 6417 UnresExpr->copyTemplateArgumentsInto(TemplateArgsBuffer); 6418 TemplateArgs = &TemplateArgsBuffer; 6419 } 6420 6421 for (UnresolvedMemberExpr::decls_iterator I = UnresExpr->decls_begin(), 6422 E = UnresExpr->decls_end(); I != E; ++I) { 6423 6424 NamedDecl *Func = *I; 6425 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(Func->getDeclContext()); 6426 if (isa<UsingShadowDecl>(Func)) 6427 Func = cast<UsingShadowDecl>(Func)->getTargetDecl(); 6428 6429 if ((Method = dyn_cast<CXXMethodDecl>(Func))) { 6430 // If explicit template arguments were provided, we can't call a 6431 // non-template member function. 6432 if (TemplateArgs) 6433 continue; 6434 6435 AddMethodCandidate(Method, I.getPair(), ActingDC, ObjectType, 6436 Args, NumArgs, 6437 CandidateSet, /*SuppressUserConversions=*/false); 6438 } else { 6439 AddMethodTemplateCandidate(cast<FunctionTemplateDecl>(Func), 6440 I.getPair(), ActingDC, TemplateArgs, 6441 ObjectType, Args, NumArgs, 6442 CandidateSet, 6443 /*SuppressUsedConversions=*/false); 6444 } 6445 } 6446 6447 DeclarationName DeclName = UnresExpr->getMemberName(); 6448 6449 OverloadCandidateSet::iterator Best; 6450 switch (BestViableFunction(CandidateSet, UnresExpr->getLocStart(), Best)) { 6451 case OR_Success: 6452 Method = cast<CXXMethodDecl>(Best->Function); 6453 FoundDecl = Best->FoundDecl; 6454 CheckUnresolvedMemberAccess(UnresExpr, Best->FoundDecl); 6455 break; 6456 6457 case OR_No_Viable_Function: 6458 Diag(UnresExpr->getMemberLoc(), 6459 diag::err_ovl_no_viable_member_function_in_call) 6460 << DeclName << MemExprE->getSourceRange(); 6461 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6462 // FIXME: Leaking incoming expressions! 6463 return ExprError(); 6464 6465 case OR_Ambiguous: 6466 Diag(UnresExpr->getMemberLoc(), diag::err_ovl_ambiguous_member_call) 6467 << DeclName << MemExprE->getSourceRange(); 6468 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6469 // FIXME: Leaking incoming expressions! 6470 return ExprError(); 6471 6472 case OR_Deleted: 6473 Diag(UnresExpr->getMemberLoc(), diag::err_ovl_deleted_member_call) 6474 << Best->Function->isDeleted() 6475 << DeclName << MemExprE->getSourceRange(); 6476 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6477 // FIXME: Leaking incoming expressions! 6478 return ExprError(); 6479 } 6480 6481 MemExprE = FixOverloadedFunctionReference(MemExprE, FoundDecl, Method); 6482 6483 // If overload resolution picked a static member, build a 6484 // non-member call based on that function. 6485 if (Method->isStatic()) { 6486 return BuildResolvedCallExpr(MemExprE, Method, LParenLoc, 6487 Args, NumArgs, RParenLoc); 6488 } 6489 6490 MemExpr = cast<MemberExpr>(MemExprE->IgnoreParens()); 6491 } 6492 6493 assert(Method && "Member call to something that isn't a method?"); 6494 ExprOwningPtr<CXXMemberCallExpr> 6495 TheCall(this, new (Context) CXXMemberCallExpr(Context, MemExprE, Args, 6496 NumArgs, 6497 Method->getResultType().getNonReferenceType(), 6498 RParenLoc)); 6499 6500 // Check for a valid return type. 6501 if (CheckCallReturnType(Method->getResultType(), MemExpr->getMemberLoc(), 6502 TheCall.get(), Method)) 6503 return ExprError(); 6504 6505 // Convert the object argument (for a non-static member function call). 6506 // We only need to do this if there was actually an overload; otherwise 6507 // it was done at lookup. 6508 Expr *ObjectArg = MemExpr->getBase(); 6509 if (!Method->isStatic() && 6510 PerformObjectArgumentInitialization(ObjectArg, Qualifier, 6511 FoundDecl, Method)) 6512 return ExprError(); 6513 MemExpr->setBase(ObjectArg); 6514 6515 // Convert the rest of the arguments 6516 const FunctionProtoType *Proto = Method->getType()->getAs<FunctionProtoType>(); 6517 if (ConvertArgumentsForCall(&*TheCall, MemExpr, Method, Proto, Args, NumArgs, 6518 RParenLoc)) 6519 return ExprError(); 6520 6521 if (CheckFunctionCall(Method, TheCall.get())) 6522 return ExprError(); 6523 6524 return MaybeBindToTemporary(TheCall.release()); 6525} 6526 6527/// BuildCallToObjectOfClassType - Build a call to an object of class 6528/// type (C++ [over.call.object]), which can end up invoking an 6529/// overloaded function call operator (@c operator()) or performing a 6530/// user-defined conversion on the object argument. 6531Sema::ExprResult 6532Sema::BuildCallToObjectOfClassType(Scope *S, Expr *Object, 6533 SourceLocation LParenLoc, 6534 Expr **Args, unsigned NumArgs, 6535 SourceLocation *CommaLocs, 6536 SourceLocation RParenLoc) { 6537 assert(Object->getType()->isRecordType() && "Requires object type argument"); 6538 const RecordType *Record = Object->getType()->getAs<RecordType>(); 6539 6540 // C++ [over.call.object]p1: 6541 // If the primary-expression E in the function call syntax 6542 // evaluates to a class object of type "cv T", then the set of 6543 // candidate functions includes at least the function call 6544 // operators of T. The function call operators of T are obtained by 6545 // ordinary lookup of the name operator() in the context of 6546 // (E).operator(). 6547 OverloadCandidateSet CandidateSet(LParenLoc); 6548 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Call); 6549 6550 if (RequireCompleteType(LParenLoc, Object->getType(), 6551 PDiag(diag::err_incomplete_object_call) 6552 << Object->getSourceRange())) 6553 return true; 6554 6555 LookupResult R(*this, OpName, LParenLoc, LookupOrdinaryName); 6556 LookupQualifiedName(R, Record->getDecl()); 6557 R.suppressDiagnostics(); 6558 6559 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 6560 Oper != OperEnd; ++Oper) { 6561 AddMethodCandidate(Oper.getPair(), Object->getType(), 6562 Args, NumArgs, CandidateSet, 6563 /*SuppressUserConversions=*/ false); 6564 } 6565 6566 // C++ [over.call.object]p2: 6567 // In addition, for each conversion function declared in T of the 6568 // form 6569 // 6570 // operator conversion-type-id () cv-qualifier; 6571 // 6572 // where cv-qualifier is the same cv-qualification as, or a 6573 // greater cv-qualification than, cv, and where conversion-type-id 6574 // denotes the type "pointer to function of (P1,...,Pn) returning 6575 // R", or the type "reference to pointer to function of 6576 // (P1,...,Pn) returning R", or the type "reference to function 6577 // of (P1,...,Pn) returning R", a surrogate call function [...] 6578 // is also considered as a candidate function. Similarly, 6579 // surrogate call functions are added to the set of candidate 6580 // functions for each conversion function declared in an 6581 // accessible base class provided the function is not hidden 6582 // within T by another intervening declaration. 6583 const UnresolvedSetImpl *Conversions 6584 = cast<CXXRecordDecl>(Record->getDecl())->getVisibleConversionFunctions(); 6585 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 6586 E = Conversions->end(); I != E; ++I) { 6587 NamedDecl *D = *I; 6588 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext()); 6589 if (isa<UsingShadowDecl>(D)) 6590 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 6591 6592 // Skip over templated conversion functions; they aren't 6593 // surrogates. 6594 if (isa<FunctionTemplateDecl>(D)) 6595 continue; 6596 6597 CXXConversionDecl *Conv = cast<CXXConversionDecl>(D); 6598 6599 // Strip the reference type (if any) and then the pointer type (if 6600 // any) to get down to what might be a function type. 6601 QualType ConvType = Conv->getConversionType().getNonReferenceType(); 6602 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 6603 ConvType = ConvPtrType->getPointeeType(); 6604 6605 if (const FunctionProtoType *Proto = ConvType->getAs<FunctionProtoType>()) 6606 AddSurrogateCandidate(Conv, I.getPair(), ActingContext, Proto, 6607 Object->getType(), Args, NumArgs, 6608 CandidateSet); 6609 } 6610 6611 // Perform overload resolution. 6612 OverloadCandidateSet::iterator Best; 6613 switch (BestViableFunction(CandidateSet, Object->getLocStart(), Best)) { 6614 case OR_Success: 6615 // Overload resolution succeeded; we'll build the appropriate call 6616 // below. 6617 break; 6618 6619 case OR_No_Viable_Function: 6620 if (CandidateSet.empty()) 6621 Diag(Object->getSourceRange().getBegin(), diag::err_ovl_no_oper) 6622 << Object->getType() << /*call*/ 1 6623 << Object->getSourceRange(); 6624 else 6625 Diag(Object->getSourceRange().getBegin(), 6626 diag::err_ovl_no_viable_object_call) 6627 << Object->getType() << Object->getSourceRange(); 6628 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6629 break; 6630 6631 case OR_Ambiguous: 6632 Diag(Object->getSourceRange().getBegin(), 6633 diag::err_ovl_ambiguous_object_call) 6634 << Object->getType() << Object->getSourceRange(); 6635 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, NumArgs); 6636 break; 6637 6638 case OR_Deleted: 6639 Diag(Object->getSourceRange().getBegin(), 6640 diag::err_ovl_deleted_object_call) 6641 << Best->Function->isDeleted() 6642 << Object->getType() << Object->getSourceRange(); 6643 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6644 break; 6645 } 6646 6647 if (Best == CandidateSet.end()) { 6648 // We had an error; delete all of the subexpressions and return 6649 // the error. 6650 Object->Destroy(Context); 6651 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 6652 Args[ArgIdx]->Destroy(Context); 6653 return true; 6654 } 6655 6656 if (Best->Function == 0) { 6657 // Since there is no function declaration, this is one of the 6658 // surrogate candidates. Dig out the conversion function. 6659 CXXConversionDecl *Conv 6660 = cast<CXXConversionDecl>( 6661 Best->Conversions[0].UserDefined.ConversionFunction); 6662 6663 CheckMemberOperatorAccess(LParenLoc, Object, 0, Best->FoundDecl); 6664 6665 // We selected one of the surrogate functions that converts the 6666 // object parameter to a function pointer. Perform the conversion 6667 // on the object argument, then let ActOnCallExpr finish the job. 6668 6669 // Create an implicit member expr to refer to the conversion operator. 6670 // and then call it. 6671 CXXMemberCallExpr *CE = BuildCXXMemberCallExpr(Object, Best->FoundDecl, 6672 Conv); 6673 6674 return ActOnCallExpr(S, ExprArg(*this, CE), LParenLoc, 6675 MultiExprArg(*this, (ExprTy**)Args, NumArgs), 6676 CommaLocs, RParenLoc).result(); 6677 } 6678 6679 CheckMemberOperatorAccess(LParenLoc, Object, 0, Best->FoundDecl); 6680 6681 // We found an overloaded operator(). Build a CXXOperatorCallExpr 6682 // that calls this method, using Object for the implicit object 6683 // parameter and passing along the remaining arguments. 6684 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 6685 const FunctionProtoType *Proto = Method->getType()->getAs<FunctionProtoType>(); 6686 6687 unsigned NumArgsInProto = Proto->getNumArgs(); 6688 unsigned NumArgsToCheck = NumArgs; 6689 6690 // Build the full argument list for the method call (the 6691 // implicit object parameter is placed at the beginning of the 6692 // list). 6693 Expr **MethodArgs; 6694 if (NumArgs < NumArgsInProto) { 6695 NumArgsToCheck = NumArgsInProto; 6696 MethodArgs = new Expr*[NumArgsInProto + 1]; 6697 } else { 6698 MethodArgs = new Expr*[NumArgs + 1]; 6699 } 6700 MethodArgs[0] = Object; 6701 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 6702 MethodArgs[ArgIdx + 1] = Args[ArgIdx]; 6703 6704 Expr *NewFn = new (Context) DeclRefExpr(Method, Method->getType(), 6705 SourceLocation()); 6706 UsualUnaryConversions(NewFn); 6707 6708 // Once we've built TheCall, all of the expressions are properly 6709 // owned. 6710 QualType ResultTy = Method->getResultType().getNonReferenceType(); 6711 ExprOwningPtr<CXXOperatorCallExpr> 6712 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Call, NewFn, 6713 MethodArgs, NumArgs + 1, 6714 ResultTy, RParenLoc)); 6715 delete [] MethodArgs; 6716 6717 if (CheckCallReturnType(Method->getResultType(), LParenLoc, TheCall.get(), 6718 Method)) 6719 return true; 6720 6721 // We may have default arguments. If so, we need to allocate more 6722 // slots in the call for them. 6723 if (NumArgs < NumArgsInProto) 6724 TheCall->setNumArgs(Context, NumArgsInProto + 1); 6725 else if (NumArgs > NumArgsInProto) 6726 NumArgsToCheck = NumArgsInProto; 6727 6728 bool IsError = false; 6729 6730 // Initialize the implicit object parameter. 6731 IsError |= PerformObjectArgumentInitialization(Object, /*Qualifier=*/0, 6732 Best->FoundDecl, Method); 6733 TheCall->setArg(0, Object); 6734 6735 6736 // Check the argument types. 6737 for (unsigned i = 0; i != NumArgsToCheck; i++) { 6738 Expr *Arg; 6739 if (i < NumArgs) { 6740 Arg = Args[i]; 6741 6742 // Pass the argument. 6743 6744 OwningExprResult InputInit 6745 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 6746 Method->getParamDecl(i)), 6747 SourceLocation(), Owned(Arg)); 6748 6749 IsError |= InputInit.isInvalid(); 6750 Arg = InputInit.takeAs<Expr>(); 6751 } else { 6752 OwningExprResult DefArg 6753 = BuildCXXDefaultArgExpr(LParenLoc, Method, Method->getParamDecl(i)); 6754 if (DefArg.isInvalid()) { 6755 IsError = true; 6756 break; 6757 } 6758 6759 Arg = DefArg.takeAs<Expr>(); 6760 } 6761 6762 TheCall->setArg(i + 1, Arg); 6763 } 6764 6765 // If this is a variadic call, handle args passed through "...". 6766 if (Proto->isVariadic()) { 6767 // Promote the arguments (C99 6.5.2.2p7). 6768 for (unsigned i = NumArgsInProto; i != NumArgs; i++) { 6769 Expr *Arg = Args[i]; 6770 IsError |= DefaultVariadicArgumentPromotion(Arg, VariadicMethod); 6771 TheCall->setArg(i + 1, Arg); 6772 } 6773 } 6774 6775 if (IsError) return true; 6776 6777 if (CheckFunctionCall(Method, TheCall.get())) 6778 return true; 6779 6780 return MaybeBindToTemporary(TheCall.release()).result(); 6781} 6782 6783/// BuildOverloadedArrowExpr - Build a call to an overloaded @c operator-> 6784/// (if one exists), where @c Base is an expression of class type and 6785/// @c Member is the name of the member we're trying to find. 6786Sema::OwningExprResult 6787Sema::BuildOverloadedArrowExpr(Scope *S, ExprArg BaseIn, SourceLocation OpLoc) { 6788 Expr *Base = static_cast<Expr *>(BaseIn.get()); 6789 assert(Base->getType()->isRecordType() && "left-hand side must have class type"); 6790 6791 SourceLocation Loc = Base->getExprLoc(); 6792 6793 // C++ [over.ref]p1: 6794 // 6795 // [...] An expression x->m is interpreted as (x.operator->())->m 6796 // for a class object x of type T if T::operator->() exists and if 6797 // the operator is selected as the best match function by the 6798 // overload resolution mechanism (13.3). 6799 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Arrow); 6800 OverloadCandidateSet CandidateSet(Loc); 6801 const RecordType *BaseRecord = Base->getType()->getAs<RecordType>(); 6802 6803 if (RequireCompleteType(Loc, Base->getType(), 6804 PDiag(diag::err_typecheck_incomplete_tag) 6805 << Base->getSourceRange())) 6806 return ExprError(); 6807 6808 LookupResult R(*this, OpName, OpLoc, LookupOrdinaryName); 6809 LookupQualifiedName(R, BaseRecord->getDecl()); 6810 R.suppressDiagnostics(); 6811 6812 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 6813 Oper != OperEnd; ++Oper) { 6814 AddMethodCandidate(Oper.getPair(), Base->getType(), 0, 0, CandidateSet, 6815 /*SuppressUserConversions=*/false); 6816 } 6817 6818 // Perform overload resolution. 6819 OverloadCandidateSet::iterator Best; 6820 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 6821 case OR_Success: 6822 // Overload resolution succeeded; we'll build the call below. 6823 break; 6824 6825 case OR_No_Viable_Function: 6826 if (CandidateSet.empty()) 6827 Diag(OpLoc, diag::err_typecheck_member_reference_arrow) 6828 << Base->getType() << Base->getSourceRange(); 6829 else 6830 Diag(OpLoc, diag::err_ovl_no_viable_oper) 6831 << "operator->" << Base->getSourceRange(); 6832 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, &Base, 1); 6833 return ExprError(); 6834 6835 case OR_Ambiguous: 6836 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 6837 << "->" << Base->getSourceRange(); 6838 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, &Base, 1); 6839 return ExprError(); 6840 6841 case OR_Deleted: 6842 Diag(OpLoc, diag::err_ovl_deleted_oper) 6843 << Best->Function->isDeleted() 6844 << "->" << Base->getSourceRange(); 6845 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, &Base, 1); 6846 return ExprError(); 6847 } 6848 6849 CheckMemberOperatorAccess(OpLoc, Base, 0, Best->FoundDecl); 6850 6851 // Convert the object parameter. 6852 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 6853 if (PerformObjectArgumentInitialization(Base, /*Qualifier=*/0, 6854 Best->FoundDecl, Method)) 6855 return ExprError(); 6856 6857 // No concerns about early exits now. 6858 BaseIn.release(); 6859 6860 // Build the operator call. 6861 Expr *FnExpr = new (Context) DeclRefExpr(Method, Method->getType(), 6862 SourceLocation()); 6863 UsualUnaryConversions(FnExpr); 6864 6865 QualType ResultTy = Method->getResultType().getNonReferenceType(); 6866 ExprOwningPtr<CXXOperatorCallExpr> 6867 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Arrow, FnExpr, 6868 &Base, 1, ResultTy, OpLoc)); 6869 6870 if (CheckCallReturnType(Method->getResultType(), OpLoc, TheCall.get(), 6871 Method)) 6872 return ExprError(); 6873 return move(TheCall); 6874} 6875 6876/// FixOverloadedFunctionReference - E is an expression that refers to 6877/// a C++ overloaded function (possibly with some parentheses and 6878/// perhaps a '&' around it). We have resolved the overloaded function 6879/// to the function declaration Fn, so patch up the expression E to 6880/// refer (possibly indirectly) to Fn. Returns the new expr. 6881Expr *Sema::FixOverloadedFunctionReference(Expr *E, DeclAccessPair Found, 6882 FunctionDecl *Fn) { 6883 if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) { 6884 Expr *SubExpr = FixOverloadedFunctionReference(PE->getSubExpr(), 6885 Found, Fn); 6886 if (SubExpr == PE->getSubExpr()) 6887 return PE->Retain(); 6888 6889 return new (Context) ParenExpr(PE->getLParen(), PE->getRParen(), SubExpr); 6890 } 6891 6892 if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) { 6893 Expr *SubExpr = FixOverloadedFunctionReference(ICE->getSubExpr(), 6894 Found, Fn); 6895 assert(Context.hasSameType(ICE->getSubExpr()->getType(), 6896 SubExpr->getType()) && 6897 "Implicit cast type cannot be determined from overload"); 6898 if (SubExpr == ICE->getSubExpr()) 6899 return ICE->Retain(); 6900 6901 return new (Context) ImplicitCastExpr(ICE->getType(), 6902 ICE->getCastKind(), 6903 SubExpr, CXXBaseSpecifierArray(), 6904 ICE->isLvalueCast()); 6905 } 6906 6907 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(E)) { 6908 assert(UnOp->getOpcode() == UnaryOperator::AddrOf && 6909 "Can only take the address of an overloaded function"); 6910 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 6911 if (Method->isStatic()) { 6912 // Do nothing: static member functions aren't any different 6913 // from non-member functions. 6914 } else { 6915 // Fix the sub expression, which really has to be an 6916 // UnresolvedLookupExpr holding an overloaded member function 6917 // or template. 6918 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(), 6919 Found, Fn); 6920 if (SubExpr == UnOp->getSubExpr()) 6921 return UnOp->Retain(); 6922 6923 assert(isa<DeclRefExpr>(SubExpr) 6924 && "fixed to something other than a decl ref"); 6925 assert(cast<DeclRefExpr>(SubExpr)->getQualifier() 6926 && "fixed to a member ref with no nested name qualifier"); 6927 6928 // We have taken the address of a pointer to member 6929 // function. Perform the computation here so that we get the 6930 // appropriate pointer to member type. 6931 QualType ClassType 6932 = Context.getTypeDeclType(cast<RecordDecl>(Method->getDeclContext())); 6933 QualType MemPtrType 6934 = Context.getMemberPointerType(Fn->getType(), ClassType.getTypePtr()); 6935 6936 return new (Context) UnaryOperator(SubExpr, UnaryOperator::AddrOf, 6937 MemPtrType, UnOp->getOperatorLoc()); 6938 } 6939 } 6940 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(), 6941 Found, Fn); 6942 if (SubExpr == UnOp->getSubExpr()) 6943 return UnOp->Retain(); 6944 6945 return new (Context) UnaryOperator(SubExpr, UnaryOperator::AddrOf, 6946 Context.getPointerType(SubExpr->getType()), 6947 UnOp->getOperatorLoc()); 6948 } 6949 6950 if (UnresolvedLookupExpr *ULE = dyn_cast<UnresolvedLookupExpr>(E)) { 6951 // FIXME: avoid copy. 6952 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 6953 if (ULE->hasExplicitTemplateArgs()) { 6954 ULE->copyTemplateArgumentsInto(TemplateArgsBuffer); 6955 TemplateArgs = &TemplateArgsBuffer; 6956 } 6957 6958 return DeclRefExpr::Create(Context, 6959 ULE->getQualifier(), 6960 ULE->getQualifierRange(), 6961 Fn, 6962 ULE->getNameLoc(), 6963 Fn->getType(), 6964 TemplateArgs); 6965 } 6966 6967 if (UnresolvedMemberExpr *MemExpr = dyn_cast<UnresolvedMemberExpr>(E)) { 6968 // FIXME: avoid copy. 6969 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 6970 if (MemExpr->hasExplicitTemplateArgs()) { 6971 MemExpr->copyTemplateArgumentsInto(TemplateArgsBuffer); 6972 TemplateArgs = &TemplateArgsBuffer; 6973 } 6974 6975 Expr *Base; 6976 6977 // If we're filling in 6978 if (MemExpr->isImplicitAccess()) { 6979 if (cast<CXXMethodDecl>(Fn)->isStatic()) { 6980 return DeclRefExpr::Create(Context, 6981 MemExpr->getQualifier(), 6982 MemExpr->getQualifierRange(), 6983 Fn, 6984 MemExpr->getMemberLoc(), 6985 Fn->getType(), 6986 TemplateArgs); 6987 } else { 6988 SourceLocation Loc = MemExpr->getMemberLoc(); 6989 if (MemExpr->getQualifier()) 6990 Loc = MemExpr->getQualifierRange().getBegin(); 6991 Base = new (Context) CXXThisExpr(Loc, 6992 MemExpr->getBaseType(), 6993 /*isImplicit=*/true); 6994 } 6995 } else 6996 Base = MemExpr->getBase()->Retain(); 6997 6998 return MemberExpr::Create(Context, Base, 6999 MemExpr->isArrow(), 7000 MemExpr->getQualifier(), 7001 MemExpr->getQualifierRange(), 7002 Fn, 7003 Found, 7004 MemExpr->getMemberLoc(), 7005 TemplateArgs, 7006 Fn->getType()); 7007 } 7008 7009 assert(false && "Invalid reference to overloaded function"); 7010 return E->Retain(); 7011} 7012 7013Sema::OwningExprResult Sema::FixOverloadedFunctionReference(OwningExprResult E, 7014 DeclAccessPair Found, 7015 FunctionDecl *Fn) { 7016 return Owned(FixOverloadedFunctionReference((Expr *)E.get(), Found, Fn)); 7017} 7018 7019} // end namespace clang 7020