SemaOverload.cpp revision 74eb6581973124a0e7e6ffe50bde081379030c34
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->getNameAsString() << "'"; 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 !std::equal(OldType->arg_type_begin(), OldType->arg_type_end(), 378 NewType->arg_type_begin()))) 379 return true; 380 381 // C++ [temp.over.link]p4: 382 // The signature of a function template consists of its function 383 // signature, its return type and its template parameter list. The names 384 // of the template parameters are significant only for establishing the 385 // relationship between the template parameters and the rest of the 386 // signature. 387 // 388 // We check the return type and template parameter lists for function 389 // templates first; the remaining checks follow. 390 if (NewTemplate && 391 (!TemplateParameterListsAreEqual(NewTemplate->getTemplateParameters(), 392 OldTemplate->getTemplateParameters(), 393 false, TPL_TemplateMatch) || 394 OldType->getResultType() != NewType->getResultType())) 395 return true; 396 397 // If the function is a class member, its signature includes the 398 // cv-qualifiers (if any) on the function itself. 399 // 400 // As part of this, also check whether one of the member functions 401 // is static, in which case they are not overloads (C++ 402 // 13.1p2). While not part of the definition of the signature, 403 // this check is important to determine whether these functions 404 // can be overloaded. 405 CXXMethodDecl* OldMethod = dyn_cast<CXXMethodDecl>(Old); 406 CXXMethodDecl* NewMethod = dyn_cast<CXXMethodDecl>(New); 407 if (OldMethod && NewMethod && 408 !OldMethod->isStatic() && !NewMethod->isStatic() && 409 OldMethod->getTypeQualifiers() != NewMethod->getTypeQualifiers()) 410 return true; 411 412 // The signatures match; this is not an overload. 413 return false; 414} 415 416/// TryImplicitConversion - Attempt to perform an implicit conversion 417/// from the given expression (Expr) to the given type (ToType). This 418/// function returns an implicit conversion sequence that can be used 419/// to perform the initialization. Given 420/// 421/// void f(float f); 422/// void g(int i) { f(i); } 423/// 424/// this routine would produce an implicit conversion sequence to 425/// describe the initialization of f from i, which will be a standard 426/// conversion sequence containing an lvalue-to-rvalue conversion (C++ 427/// 4.1) followed by a floating-integral conversion (C++ 4.9). 428// 429/// Note that this routine only determines how the conversion can be 430/// performed; it does not actually perform the conversion. As such, 431/// it will not produce any diagnostics if no conversion is available, 432/// but will instead return an implicit conversion sequence of kind 433/// "BadConversion". 434/// 435/// If @p SuppressUserConversions, then user-defined conversions are 436/// not permitted. 437/// If @p AllowExplicit, then explicit user-defined conversions are 438/// permitted. 439/// If @p ForceRValue, then overloading is performed as if From was an rvalue, 440/// no matter its actual lvalueness. 441/// If @p UserCast, the implicit conversion is being done for a user-specified 442/// cast. 443ImplicitConversionSequence 444Sema::TryImplicitConversion(Expr* From, QualType ToType, 445 bool SuppressUserConversions, 446 bool AllowExplicit, bool ForceRValue, 447 bool InOverloadResolution, 448 bool UserCast) { 449 ImplicitConversionSequence ICS; 450 if (IsStandardConversion(From, ToType, InOverloadResolution, ICS.Standard)) { 451 ICS.setStandard(); 452 return ICS; 453 } 454 455 if (!getLangOptions().CPlusPlus) { 456 ICS.setBad(BadConversionSequence::no_conversion, From, ToType); 457 return ICS; 458 } 459 460 OverloadCandidateSet Conversions(From->getExprLoc()); 461 OverloadingResult UserDefResult 462 = IsUserDefinedConversion(From, ToType, ICS.UserDefined, Conversions, 463 !SuppressUserConversions, AllowExplicit, 464 UserCast); 465 466 if (UserDefResult == OR_Success) { 467 ICS.setUserDefined(); 468 // C++ [over.ics.user]p4: 469 // A conversion of an expression of class type to the same class 470 // type is given Exact Match rank, and a conversion of an 471 // expression of class type to a base class of that type is 472 // given Conversion rank, in spite of the fact that a copy 473 // constructor (i.e., a user-defined conversion function) is 474 // called for those cases. 475 if (CXXConstructorDecl *Constructor 476 = dyn_cast<CXXConstructorDecl>(ICS.UserDefined.ConversionFunction)) { 477 QualType FromCanon 478 = Context.getCanonicalType(From->getType().getUnqualifiedType()); 479 QualType ToCanon = Context.getCanonicalType(ToType).getUnqualifiedType(); 480 if (Constructor->isCopyConstructor() && 481 (FromCanon == ToCanon || IsDerivedFrom(FromCanon, ToCanon))) { 482 // Turn this into a "standard" conversion sequence, so that it 483 // gets ranked with standard conversion sequences. 484 ICS.setStandard(); 485 ICS.Standard.setAsIdentityConversion(); 486 ICS.Standard.setFromType(From->getType()); 487 ICS.Standard.setAllToTypes(ToType); 488 ICS.Standard.CopyConstructor = Constructor; 489 if (ToCanon != FromCanon) 490 ICS.Standard.Second = ICK_Derived_To_Base; 491 } 492 } 493 494 // C++ [over.best.ics]p4: 495 // However, when considering the argument of a user-defined 496 // conversion function that is a candidate by 13.3.1.3 when 497 // invoked for the copying of the temporary in the second step 498 // of a class copy-initialization, or by 13.3.1.4, 13.3.1.5, or 499 // 13.3.1.6 in all cases, only standard conversion sequences and 500 // ellipsis conversion sequences are allowed. 501 if (SuppressUserConversions && ICS.isUserDefined()) { 502 ICS.setBad(BadConversionSequence::suppressed_user, From, ToType); 503 } 504 } else if (UserDefResult == OR_Ambiguous && !SuppressUserConversions) { 505 ICS.setAmbiguous(); 506 ICS.Ambiguous.setFromType(From->getType()); 507 ICS.Ambiguous.setToType(ToType); 508 for (OverloadCandidateSet::iterator Cand = Conversions.begin(); 509 Cand != Conversions.end(); ++Cand) 510 if (Cand->Viable) 511 ICS.Ambiguous.addConversion(Cand->Function); 512 } else { 513 ICS.setBad(BadConversionSequence::no_conversion, From, ToType); 514 } 515 516 return ICS; 517} 518 519/// \brief Determine whether the conversion from FromType to ToType is a valid 520/// conversion that strips "noreturn" off the nested function type. 521static bool IsNoReturnConversion(ASTContext &Context, QualType FromType, 522 QualType ToType, QualType &ResultTy) { 523 if (Context.hasSameUnqualifiedType(FromType, ToType)) 524 return false; 525 526 // Strip the noreturn off the type we're converting from; noreturn can 527 // safely be removed. 528 FromType = Context.getNoReturnType(FromType, false); 529 if (!Context.hasSameUnqualifiedType(FromType, ToType)) 530 return false; 531 532 ResultTy = FromType; 533 return true; 534} 535 536/// IsStandardConversion - Determines whether there is a standard 537/// conversion sequence (C++ [conv], C++ [over.ics.scs]) from the 538/// expression From to the type ToType. Standard conversion sequences 539/// only consider non-class types; for conversions that involve class 540/// types, use TryImplicitConversion. If a conversion exists, SCS will 541/// contain the standard conversion sequence required to perform this 542/// conversion and this routine will return true. Otherwise, this 543/// routine will return false and the value of SCS is unspecified. 544bool 545Sema::IsStandardConversion(Expr* From, QualType ToType, 546 bool InOverloadResolution, 547 StandardConversionSequence &SCS) { 548 QualType FromType = From->getType(); 549 550 // Standard conversions (C++ [conv]) 551 SCS.setAsIdentityConversion(); 552 SCS.DeprecatedStringLiteralToCharPtr = false; 553 SCS.IncompatibleObjC = false; 554 SCS.setFromType(FromType); 555 SCS.CopyConstructor = 0; 556 557 // There are no standard conversions for class types in C++, so 558 // abort early. When overloading in C, however, we do permit 559 if (FromType->isRecordType() || ToType->isRecordType()) { 560 if (getLangOptions().CPlusPlus) 561 return false; 562 563 // When we're overloading in C, we allow, as standard conversions, 564 } 565 566 // The first conversion can be an lvalue-to-rvalue conversion, 567 // array-to-pointer conversion, or function-to-pointer conversion 568 // (C++ 4p1). 569 570 DeclAccessPair AccessPair; 571 572 // Lvalue-to-rvalue conversion (C++ 4.1): 573 // An lvalue (3.10) of a non-function, non-array type T can be 574 // converted to an rvalue. 575 Expr::isLvalueResult argIsLvalue = From->isLvalue(Context); 576 if (argIsLvalue == Expr::LV_Valid && 577 !FromType->isFunctionType() && !FromType->isArrayType() && 578 Context.getCanonicalType(FromType) != Context.OverloadTy) { 579 SCS.First = ICK_Lvalue_To_Rvalue; 580 581 // If T is a non-class type, the type of the rvalue is the 582 // cv-unqualified version of T. Otherwise, the type of the rvalue 583 // is T (C++ 4.1p1). C++ can't get here with class types; in C, we 584 // just strip the qualifiers because they don't matter. 585 FromType = FromType.getUnqualifiedType(); 586 } else if (FromType->isArrayType()) { 587 // Array-to-pointer conversion (C++ 4.2) 588 SCS.First = ICK_Array_To_Pointer; 589 590 // An lvalue or rvalue of type "array of N T" or "array of unknown 591 // bound of T" can be converted to an rvalue of type "pointer to 592 // T" (C++ 4.2p1). 593 FromType = Context.getArrayDecayedType(FromType); 594 595 if (IsStringLiteralToNonConstPointerConversion(From, ToType)) { 596 // This conversion is deprecated. (C++ D.4). 597 SCS.DeprecatedStringLiteralToCharPtr = true; 598 599 // For the purpose of ranking in overload resolution 600 // (13.3.3.1.1), this conversion is considered an 601 // array-to-pointer conversion followed by a qualification 602 // conversion (4.4). (C++ 4.2p2) 603 SCS.Second = ICK_Identity; 604 SCS.Third = ICK_Qualification; 605 SCS.setAllToTypes(FromType); 606 return true; 607 } 608 } else if (FromType->isFunctionType() && argIsLvalue == Expr::LV_Valid) { 609 // Function-to-pointer conversion (C++ 4.3). 610 SCS.First = ICK_Function_To_Pointer; 611 612 // An lvalue of function type T can be converted to an rvalue of 613 // type "pointer to T." The result is a pointer to the 614 // function. (C++ 4.3p1). 615 FromType = Context.getPointerType(FromType); 616 } else if (From->getType() == Context.OverloadTy) { 617 if (FunctionDecl *Fn 618 = ResolveAddressOfOverloadedFunction(From, ToType, false, 619 AccessPair)) { 620 // Address of overloaded function (C++ [over.over]). 621 SCS.First = ICK_Function_To_Pointer; 622 623 // We were able to resolve the address of the overloaded function, 624 // so we can convert to the type of that function. 625 FromType = Fn->getType(); 626 if (ToType->isLValueReferenceType()) 627 FromType = Context.getLValueReferenceType(FromType); 628 else if (ToType->isRValueReferenceType()) 629 FromType = Context.getRValueReferenceType(FromType); 630 else if (ToType->isMemberPointerType()) { 631 // Resolve address only succeeds if both sides are member pointers, 632 // but it doesn't have to be the same class. See DR 247. 633 // Note that this means that the type of &Derived::fn can be 634 // Ret (Base::*)(Args) if the fn overload actually found is from the 635 // base class, even if it was brought into the derived class via a 636 // using declaration. The standard isn't clear on this issue at all. 637 CXXMethodDecl *M = cast<CXXMethodDecl>(Fn); 638 FromType = Context.getMemberPointerType(FromType, 639 Context.getTypeDeclType(M->getParent()).getTypePtr()); 640 } else { 641 FromType = Context.getPointerType(FromType); 642 } 643 } else { 644 return false; 645 } 646 } else { 647 // We don't require any conversions for the first step. 648 SCS.First = ICK_Identity; 649 } 650 SCS.setToType(0, FromType); 651 652 // The second conversion can be an integral promotion, floating 653 // point promotion, integral conversion, floating point conversion, 654 // floating-integral conversion, pointer conversion, 655 // pointer-to-member conversion, or boolean conversion (C++ 4p1). 656 // For overloading in C, this can also be a "compatible-type" 657 // conversion. 658 bool IncompatibleObjC = false; 659 if (Context.hasSameUnqualifiedType(FromType, ToType)) { 660 // The unqualified versions of the types are the same: there's no 661 // conversion to do. 662 SCS.Second = ICK_Identity; 663 } else if (IsIntegralPromotion(From, FromType, ToType)) { 664 // Integral promotion (C++ 4.5). 665 SCS.Second = ICK_Integral_Promotion; 666 FromType = ToType.getUnqualifiedType(); 667 } else if (IsFloatingPointPromotion(FromType, ToType)) { 668 // Floating point promotion (C++ 4.6). 669 SCS.Second = ICK_Floating_Promotion; 670 FromType = ToType.getUnqualifiedType(); 671 } else if (IsComplexPromotion(FromType, ToType)) { 672 // Complex promotion (Clang extension) 673 SCS.Second = ICK_Complex_Promotion; 674 FromType = ToType.getUnqualifiedType(); 675 } else if ((FromType->isIntegralType() || FromType->isEnumeralType()) && 676 (ToType->isIntegralType() && !ToType->isEnumeralType())) { 677 // Integral conversions (C++ 4.7). 678 SCS.Second = ICK_Integral_Conversion; 679 FromType = ToType.getUnqualifiedType(); 680 } else if (FromType->isComplexType() && ToType->isComplexType()) { 681 // Complex conversions (C99 6.3.1.6) 682 SCS.Second = ICK_Complex_Conversion; 683 FromType = ToType.getUnqualifiedType(); 684 } else if ((FromType->isComplexType() && ToType->isArithmeticType()) || 685 (ToType->isComplexType() && FromType->isArithmeticType())) { 686 // Complex-real conversions (C99 6.3.1.7) 687 SCS.Second = ICK_Complex_Real; 688 FromType = ToType.getUnqualifiedType(); 689 } else if (FromType->isFloatingType() && ToType->isFloatingType()) { 690 // Floating point conversions (C++ 4.8). 691 SCS.Second = ICK_Floating_Conversion; 692 FromType = ToType.getUnqualifiedType(); 693 } else if ((FromType->isFloatingType() && 694 ToType->isIntegralType() && (!ToType->isBooleanType() && 695 !ToType->isEnumeralType())) || 696 ((FromType->isIntegralType() || FromType->isEnumeralType()) && 697 ToType->isFloatingType())) { 698 // Floating-integral conversions (C++ 4.9). 699 SCS.Second = ICK_Floating_Integral; 700 FromType = ToType.getUnqualifiedType(); 701 } else if (IsPointerConversion(From, FromType, ToType, InOverloadResolution, 702 FromType, IncompatibleObjC)) { 703 // Pointer conversions (C++ 4.10). 704 SCS.Second = ICK_Pointer_Conversion; 705 SCS.IncompatibleObjC = IncompatibleObjC; 706 } else if (IsMemberPointerConversion(From, FromType, ToType, 707 InOverloadResolution, FromType)) { 708 // Pointer to member conversions (4.11). 709 SCS.Second = ICK_Pointer_Member; 710 } else if (ToType->isBooleanType() && 711 (FromType->isArithmeticType() || 712 FromType->isEnumeralType() || 713 FromType->isAnyPointerType() || 714 FromType->isBlockPointerType() || 715 FromType->isMemberPointerType() || 716 FromType->isNullPtrType())) { 717 // Boolean conversions (C++ 4.12). 718 SCS.Second = ICK_Boolean_Conversion; 719 FromType = Context.BoolTy; 720 } else if (!getLangOptions().CPlusPlus && 721 Context.typesAreCompatible(ToType, FromType)) { 722 // Compatible conversions (Clang extension for C function overloading) 723 SCS.Second = ICK_Compatible_Conversion; 724 } else if (IsNoReturnConversion(Context, FromType, ToType, FromType)) { 725 // Treat a conversion that strips "noreturn" as an identity conversion. 726 SCS.Second = ICK_NoReturn_Adjustment; 727 } else { 728 // No second conversion required. 729 SCS.Second = ICK_Identity; 730 } 731 SCS.setToType(1, FromType); 732 733 QualType CanonFrom; 734 QualType CanonTo; 735 // The third conversion can be a qualification conversion (C++ 4p1). 736 if (IsQualificationConversion(FromType, ToType)) { 737 SCS.Third = ICK_Qualification; 738 FromType = ToType; 739 CanonFrom = Context.getCanonicalType(FromType); 740 CanonTo = Context.getCanonicalType(ToType); 741 } else { 742 // No conversion required 743 SCS.Third = ICK_Identity; 744 745 // C++ [over.best.ics]p6: 746 // [...] Any difference in top-level cv-qualification is 747 // subsumed by the initialization itself and does not constitute 748 // a conversion. [...] 749 CanonFrom = Context.getCanonicalType(FromType); 750 CanonTo = Context.getCanonicalType(ToType); 751 if (CanonFrom.getLocalUnqualifiedType() 752 == CanonTo.getLocalUnqualifiedType() && 753 CanonFrom.getLocalCVRQualifiers() != CanonTo.getLocalCVRQualifiers()) { 754 FromType = ToType; 755 CanonFrom = CanonTo; 756 } 757 } 758 SCS.setToType(2, FromType); 759 760 // If we have not converted the argument type to the parameter type, 761 // this is a bad conversion sequence. 762 if (CanonFrom != CanonTo) 763 return false; 764 765 return true; 766} 767 768/// IsIntegralPromotion - Determines whether the conversion from the 769/// expression From (whose potentially-adjusted type is FromType) to 770/// ToType is an integral promotion (C++ 4.5). If so, returns true and 771/// sets PromotedType to the promoted type. 772bool Sema::IsIntegralPromotion(Expr *From, QualType FromType, QualType ToType) { 773 const BuiltinType *To = ToType->getAs<BuiltinType>(); 774 // All integers are built-in. 775 if (!To) { 776 return false; 777 } 778 779 // An rvalue of type char, signed char, unsigned char, short int, or 780 // unsigned short int can be converted to an rvalue of type int if 781 // int can represent all the values of the source type; otherwise, 782 // the source rvalue can be converted to an rvalue of type unsigned 783 // int (C++ 4.5p1). 784 if (FromType->isPromotableIntegerType() && !FromType->isBooleanType() && 785 !FromType->isEnumeralType()) { 786 if (// We can promote any signed, promotable integer type to an int 787 (FromType->isSignedIntegerType() || 788 // We can promote any unsigned integer type whose size is 789 // less than int to an int. 790 (!FromType->isSignedIntegerType() && 791 Context.getTypeSize(FromType) < Context.getTypeSize(ToType)))) { 792 return To->getKind() == BuiltinType::Int; 793 } 794 795 return To->getKind() == BuiltinType::UInt; 796 } 797 798 // An rvalue of type wchar_t (3.9.1) or an enumeration type (7.2) 799 // can be converted to an rvalue of the first of the following types 800 // that can represent all the values of its underlying type: int, 801 // unsigned int, long, or unsigned long (C++ 4.5p2). 802 803 // We pre-calculate the promotion type for enum types. 804 if (const EnumType *FromEnumType = FromType->getAs<EnumType>()) 805 if (ToType->isIntegerType()) 806 return Context.hasSameUnqualifiedType(ToType, 807 FromEnumType->getDecl()->getPromotionType()); 808 809 if (FromType->isWideCharType() && ToType->isIntegerType()) { 810 // Determine whether the type we're converting from is signed or 811 // unsigned. 812 bool FromIsSigned; 813 uint64_t FromSize = Context.getTypeSize(FromType); 814 815 // FIXME: Is wchar_t signed or unsigned? We assume it's signed for now. 816 FromIsSigned = true; 817 818 // The types we'll try to promote to, in the appropriate 819 // order. Try each of these types. 820 QualType PromoteTypes[6] = { 821 Context.IntTy, Context.UnsignedIntTy, 822 Context.LongTy, Context.UnsignedLongTy , 823 Context.LongLongTy, Context.UnsignedLongLongTy 824 }; 825 for (int Idx = 0; Idx < 6; ++Idx) { 826 uint64_t ToSize = Context.getTypeSize(PromoteTypes[Idx]); 827 if (FromSize < ToSize || 828 (FromSize == ToSize && 829 FromIsSigned == PromoteTypes[Idx]->isSignedIntegerType())) { 830 // We found the type that we can promote to. If this is the 831 // type we wanted, we have a promotion. Otherwise, no 832 // promotion. 833 return Context.hasSameUnqualifiedType(ToType, PromoteTypes[Idx]); 834 } 835 } 836 } 837 838 // An rvalue for an integral bit-field (9.6) can be converted to an 839 // rvalue of type int if int can represent all the values of the 840 // bit-field; otherwise, it can be converted to unsigned int if 841 // unsigned int can represent all the values of the bit-field. If 842 // the bit-field is larger yet, no integral promotion applies to 843 // it. If the bit-field has an enumerated type, it is treated as any 844 // other value of that type for promotion purposes (C++ 4.5p3). 845 // FIXME: We should delay checking of bit-fields until we actually perform the 846 // conversion. 847 using llvm::APSInt; 848 if (From) 849 if (FieldDecl *MemberDecl = From->getBitField()) { 850 APSInt BitWidth; 851 if (FromType->isIntegralType() && !FromType->isEnumeralType() && 852 MemberDecl->getBitWidth()->isIntegerConstantExpr(BitWidth, Context)) { 853 APSInt ToSize(BitWidth.getBitWidth(), BitWidth.isUnsigned()); 854 ToSize = Context.getTypeSize(ToType); 855 856 // Are we promoting to an int from a bitfield that fits in an int? 857 if (BitWidth < ToSize || 858 (FromType->isSignedIntegerType() && BitWidth <= ToSize)) { 859 return To->getKind() == BuiltinType::Int; 860 } 861 862 // Are we promoting to an unsigned int from an unsigned bitfield 863 // that fits into an unsigned int? 864 if (FromType->isUnsignedIntegerType() && BitWidth <= ToSize) { 865 return To->getKind() == BuiltinType::UInt; 866 } 867 868 return false; 869 } 870 } 871 872 // An rvalue of type bool can be converted to an rvalue of type int, 873 // with false becoming zero and true becoming one (C++ 4.5p4). 874 if (FromType->isBooleanType() && To->getKind() == BuiltinType::Int) { 875 return true; 876 } 877 878 return false; 879} 880 881/// IsFloatingPointPromotion - Determines whether the conversion from 882/// FromType to ToType is a floating point promotion (C++ 4.6). If so, 883/// returns true and sets PromotedType to the promoted type. 884bool Sema::IsFloatingPointPromotion(QualType FromType, QualType ToType) { 885 /// An rvalue of type float can be converted to an rvalue of type 886 /// double. (C++ 4.6p1). 887 if (const BuiltinType *FromBuiltin = FromType->getAs<BuiltinType>()) 888 if (const BuiltinType *ToBuiltin = ToType->getAs<BuiltinType>()) { 889 if (FromBuiltin->getKind() == BuiltinType::Float && 890 ToBuiltin->getKind() == BuiltinType::Double) 891 return true; 892 893 // C99 6.3.1.5p1: 894 // When a float is promoted to double or long double, or a 895 // double is promoted to long double [...]. 896 if (!getLangOptions().CPlusPlus && 897 (FromBuiltin->getKind() == BuiltinType::Float || 898 FromBuiltin->getKind() == BuiltinType::Double) && 899 (ToBuiltin->getKind() == BuiltinType::LongDouble)) 900 return true; 901 } 902 903 return false; 904} 905 906/// \brief Determine if a conversion is a complex promotion. 907/// 908/// A complex promotion is defined as a complex -> complex conversion 909/// where the conversion between the underlying real types is a 910/// floating-point or integral promotion. 911bool Sema::IsComplexPromotion(QualType FromType, QualType ToType) { 912 const ComplexType *FromComplex = FromType->getAs<ComplexType>(); 913 if (!FromComplex) 914 return false; 915 916 const ComplexType *ToComplex = ToType->getAs<ComplexType>(); 917 if (!ToComplex) 918 return false; 919 920 return IsFloatingPointPromotion(FromComplex->getElementType(), 921 ToComplex->getElementType()) || 922 IsIntegralPromotion(0, FromComplex->getElementType(), 923 ToComplex->getElementType()); 924} 925 926/// BuildSimilarlyQualifiedPointerType - In a pointer conversion from 927/// the pointer type FromPtr to a pointer to type ToPointee, with the 928/// same type qualifiers as FromPtr has on its pointee type. ToType, 929/// if non-empty, will be a pointer to ToType that may or may not have 930/// the right set of qualifiers on its pointee. 931static QualType 932BuildSimilarlyQualifiedPointerType(const PointerType *FromPtr, 933 QualType ToPointee, QualType ToType, 934 ASTContext &Context) { 935 QualType CanonFromPointee = Context.getCanonicalType(FromPtr->getPointeeType()); 936 QualType CanonToPointee = Context.getCanonicalType(ToPointee); 937 Qualifiers Quals = CanonFromPointee.getQualifiers(); 938 939 // Exact qualifier match -> return the pointer type we're converting to. 940 if (CanonToPointee.getLocalQualifiers() == Quals) { 941 // ToType is exactly what we need. Return it. 942 if (!ToType.isNull()) 943 return ToType; 944 945 // Build a pointer to ToPointee. It has the right qualifiers 946 // already. 947 return Context.getPointerType(ToPointee); 948 } 949 950 // Just build a canonical type that has the right qualifiers. 951 return Context.getPointerType( 952 Context.getQualifiedType(CanonToPointee.getLocalUnqualifiedType(), 953 Quals)); 954} 955 956/// BuildSimilarlyQualifiedObjCObjectPointerType - In a pointer conversion from 957/// the FromType, which is an objective-c pointer, to ToType, which may or may 958/// not have the right set of qualifiers. 959static QualType 960BuildSimilarlyQualifiedObjCObjectPointerType(QualType FromType, 961 QualType ToType, 962 ASTContext &Context) { 963 QualType CanonFromType = Context.getCanonicalType(FromType); 964 QualType CanonToType = Context.getCanonicalType(ToType); 965 Qualifiers Quals = CanonFromType.getQualifiers(); 966 967 // Exact qualifier match -> return the pointer type we're converting to. 968 if (CanonToType.getLocalQualifiers() == Quals) 969 return ToType; 970 971 // Just build a canonical type that has the right qualifiers. 972 return Context.getQualifiedType(CanonToType.getLocalUnqualifiedType(), Quals); 973} 974 975static bool isNullPointerConstantForConversion(Expr *Expr, 976 bool InOverloadResolution, 977 ASTContext &Context) { 978 // Handle value-dependent integral null pointer constants correctly. 979 // http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#903 980 if (Expr->isValueDependent() && !Expr->isTypeDependent() && 981 Expr->getType()->isIntegralType()) 982 return !InOverloadResolution; 983 984 return Expr->isNullPointerConstant(Context, 985 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull 986 : Expr::NPC_ValueDependentIsNull); 987} 988 989/// IsPointerConversion - Determines whether the conversion of the 990/// expression From, which has the (possibly adjusted) type FromType, 991/// can be converted to the type ToType via a pointer conversion (C++ 992/// 4.10). If so, returns true and places the converted type (that 993/// might differ from ToType in its cv-qualifiers at some level) into 994/// ConvertedType. 995/// 996/// This routine also supports conversions to and from block pointers 997/// and conversions with Objective-C's 'id', 'id<protocols...>', and 998/// pointers to interfaces. FIXME: Once we've determined the 999/// appropriate overloading rules for Objective-C, we may want to 1000/// split the Objective-C checks into a different routine; however, 1001/// GCC seems to consider all of these conversions to be pointer 1002/// conversions, so for now they live here. IncompatibleObjC will be 1003/// set if the conversion is an allowed Objective-C conversion that 1004/// should result in a warning. 1005bool Sema::IsPointerConversion(Expr *From, QualType FromType, QualType ToType, 1006 bool InOverloadResolution, 1007 QualType& ConvertedType, 1008 bool &IncompatibleObjC) { 1009 IncompatibleObjC = false; 1010 if (isObjCPointerConversion(FromType, ToType, ConvertedType, IncompatibleObjC)) 1011 return true; 1012 1013 // Conversion from a null pointer constant to any Objective-C pointer type. 1014 if (ToType->isObjCObjectPointerType() && 1015 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1016 ConvertedType = ToType; 1017 return true; 1018 } 1019 1020 // Blocks: Block pointers can be converted to void*. 1021 if (FromType->isBlockPointerType() && ToType->isPointerType() && 1022 ToType->getAs<PointerType>()->getPointeeType()->isVoidType()) { 1023 ConvertedType = ToType; 1024 return true; 1025 } 1026 // Blocks: A null pointer constant can be converted to a block 1027 // pointer type. 1028 if (ToType->isBlockPointerType() && 1029 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1030 ConvertedType = ToType; 1031 return true; 1032 } 1033 1034 // If the left-hand-side is nullptr_t, the right side can be a null 1035 // pointer constant. 1036 if (ToType->isNullPtrType() && 1037 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1038 ConvertedType = ToType; 1039 return true; 1040 } 1041 1042 const PointerType* ToTypePtr = ToType->getAs<PointerType>(); 1043 if (!ToTypePtr) 1044 return false; 1045 1046 // A null pointer constant can be converted to a pointer type (C++ 4.10p1). 1047 if (isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1048 ConvertedType = ToType; 1049 return true; 1050 } 1051 1052 // Beyond this point, both types need to be pointers 1053 // , including objective-c pointers. 1054 QualType ToPointeeType = ToTypePtr->getPointeeType(); 1055 if (FromType->isObjCObjectPointerType() && ToPointeeType->isVoidType()) { 1056 ConvertedType = BuildSimilarlyQualifiedObjCObjectPointerType(FromType, 1057 ToType, Context); 1058 return true; 1059 1060 } 1061 const PointerType *FromTypePtr = FromType->getAs<PointerType>(); 1062 if (!FromTypePtr) 1063 return false; 1064 1065 QualType FromPointeeType = FromTypePtr->getPointeeType(); 1066 1067 // An rvalue of type "pointer to cv T," where T is an object type, 1068 // can be converted to an rvalue of type "pointer to cv void" (C++ 1069 // 4.10p2). 1070 if (FromPointeeType->isObjectType() && ToPointeeType->isVoidType()) { 1071 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1072 ToPointeeType, 1073 ToType, Context); 1074 return true; 1075 } 1076 1077 // When we're overloading in C, we allow a special kind of pointer 1078 // conversion for compatible-but-not-identical pointee types. 1079 if (!getLangOptions().CPlusPlus && 1080 Context.typesAreCompatible(FromPointeeType, ToPointeeType)) { 1081 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1082 ToPointeeType, 1083 ToType, Context); 1084 return true; 1085 } 1086 1087 // C++ [conv.ptr]p3: 1088 // 1089 // An rvalue of type "pointer to cv D," where D is a class type, 1090 // can be converted to an rvalue of type "pointer to cv B," where 1091 // B is a base class (clause 10) of D. If B is an inaccessible 1092 // (clause 11) or ambiguous (10.2) base class of D, a program that 1093 // necessitates this conversion is ill-formed. The result of the 1094 // conversion is a pointer to the base class sub-object of the 1095 // derived class object. The null pointer value is converted to 1096 // the null pointer value of the destination type. 1097 // 1098 // Note that we do not check for ambiguity or inaccessibility 1099 // here. That is handled by CheckPointerConversion. 1100 if (getLangOptions().CPlusPlus && 1101 FromPointeeType->isRecordType() && ToPointeeType->isRecordType() && 1102 !Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType) && 1103 !RequireCompleteType(From->getLocStart(), FromPointeeType, PDiag()) && 1104 IsDerivedFrom(FromPointeeType, ToPointeeType)) { 1105 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1106 ToPointeeType, 1107 ToType, Context); 1108 return true; 1109 } 1110 1111 return false; 1112} 1113 1114/// isObjCPointerConversion - Determines whether this is an 1115/// Objective-C pointer conversion. Subroutine of IsPointerConversion, 1116/// with the same arguments and return values. 1117bool Sema::isObjCPointerConversion(QualType FromType, QualType ToType, 1118 QualType& ConvertedType, 1119 bool &IncompatibleObjC) { 1120 if (!getLangOptions().ObjC1) 1121 return false; 1122 1123 // First, we handle all conversions on ObjC object pointer types. 1124 const ObjCObjectPointerType* ToObjCPtr = ToType->getAs<ObjCObjectPointerType>(); 1125 const ObjCObjectPointerType *FromObjCPtr = 1126 FromType->getAs<ObjCObjectPointerType>(); 1127 1128 if (ToObjCPtr && FromObjCPtr) { 1129 // Objective C++: We're able to convert between "id" or "Class" and a 1130 // pointer to any interface (in both directions). 1131 if (ToObjCPtr->isObjCBuiltinType() && FromObjCPtr->isObjCBuiltinType()) { 1132 ConvertedType = ToType; 1133 return true; 1134 } 1135 // Conversions with Objective-C's id<...>. 1136 if ((FromObjCPtr->isObjCQualifiedIdType() || 1137 ToObjCPtr->isObjCQualifiedIdType()) && 1138 Context.ObjCQualifiedIdTypesAreCompatible(ToType, FromType, 1139 /*compare=*/false)) { 1140 ConvertedType = ToType; 1141 return true; 1142 } 1143 // Objective C++: We're able to convert from a pointer to an 1144 // interface to a pointer to a different interface. 1145 if (Context.canAssignObjCInterfaces(ToObjCPtr, FromObjCPtr)) { 1146 const ObjCInterfaceType* LHS = ToObjCPtr->getInterfaceType(); 1147 const ObjCInterfaceType* RHS = FromObjCPtr->getInterfaceType(); 1148 if (getLangOptions().CPlusPlus && LHS && RHS && 1149 !ToObjCPtr->getPointeeType().isAtLeastAsQualifiedAs( 1150 FromObjCPtr->getPointeeType())) 1151 return false; 1152 ConvertedType = ToType; 1153 return true; 1154 } 1155 1156 if (Context.canAssignObjCInterfaces(FromObjCPtr, ToObjCPtr)) { 1157 // Okay: this is some kind of implicit downcast of Objective-C 1158 // interfaces, which is permitted. However, we're going to 1159 // complain about it. 1160 IncompatibleObjC = true; 1161 ConvertedType = FromType; 1162 return true; 1163 } 1164 } 1165 // Beyond this point, both types need to be C pointers or block pointers. 1166 QualType ToPointeeType; 1167 if (const PointerType *ToCPtr = ToType->getAs<PointerType>()) 1168 ToPointeeType = ToCPtr->getPointeeType(); 1169 else if (const BlockPointerType *ToBlockPtr = 1170 ToType->getAs<BlockPointerType>()) { 1171 // Objective C++: We're able to convert from a pointer to any object 1172 // to a block pointer type. 1173 if (FromObjCPtr && FromObjCPtr->isObjCBuiltinType()) { 1174 ConvertedType = ToType; 1175 return true; 1176 } 1177 ToPointeeType = ToBlockPtr->getPointeeType(); 1178 } 1179 else if (FromType->getAs<BlockPointerType>() && 1180 ToObjCPtr && ToObjCPtr->isObjCBuiltinType()) { 1181 // Objective C++: We're able to convert from a block pointer type to a 1182 // pointer to any object. 1183 ConvertedType = ToType; 1184 return true; 1185 } 1186 else 1187 return false; 1188 1189 QualType FromPointeeType; 1190 if (const PointerType *FromCPtr = FromType->getAs<PointerType>()) 1191 FromPointeeType = FromCPtr->getPointeeType(); 1192 else if (const BlockPointerType *FromBlockPtr = FromType->getAs<BlockPointerType>()) 1193 FromPointeeType = FromBlockPtr->getPointeeType(); 1194 else 1195 return false; 1196 1197 // If we have pointers to pointers, recursively check whether this 1198 // is an Objective-C conversion. 1199 if (FromPointeeType->isPointerType() && ToPointeeType->isPointerType() && 1200 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, 1201 IncompatibleObjC)) { 1202 // We always complain about this conversion. 1203 IncompatibleObjC = true; 1204 ConvertedType = ToType; 1205 return true; 1206 } 1207 // Allow conversion of pointee being objective-c pointer to another one; 1208 // as in I* to id. 1209 if (FromPointeeType->getAs<ObjCObjectPointerType>() && 1210 ToPointeeType->getAs<ObjCObjectPointerType>() && 1211 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, 1212 IncompatibleObjC)) { 1213 ConvertedType = ToType; 1214 return true; 1215 } 1216 1217 // If we have pointers to functions or blocks, check whether the only 1218 // differences in the argument and result types are in Objective-C 1219 // pointer conversions. If so, we permit the conversion (but 1220 // complain about it). 1221 const FunctionProtoType *FromFunctionType 1222 = FromPointeeType->getAs<FunctionProtoType>(); 1223 const FunctionProtoType *ToFunctionType 1224 = ToPointeeType->getAs<FunctionProtoType>(); 1225 if (FromFunctionType && ToFunctionType) { 1226 // If the function types are exactly the same, this isn't an 1227 // Objective-C pointer conversion. 1228 if (Context.getCanonicalType(FromPointeeType) 1229 == Context.getCanonicalType(ToPointeeType)) 1230 return false; 1231 1232 // Perform the quick checks that will tell us whether these 1233 // function types are obviously different. 1234 if (FromFunctionType->getNumArgs() != ToFunctionType->getNumArgs() || 1235 FromFunctionType->isVariadic() != ToFunctionType->isVariadic() || 1236 FromFunctionType->getTypeQuals() != ToFunctionType->getTypeQuals()) 1237 return false; 1238 1239 bool HasObjCConversion = false; 1240 if (Context.getCanonicalType(FromFunctionType->getResultType()) 1241 == Context.getCanonicalType(ToFunctionType->getResultType())) { 1242 // Okay, the types match exactly. Nothing to do. 1243 } else if (isObjCPointerConversion(FromFunctionType->getResultType(), 1244 ToFunctionType->getResultType(), 1245 ConvertedType, IncompatibleObjC)) { 1246 // Okay, we have an Objective-C pointer conversion. 1247 HasObjCConversion = true; 1248 } else { 1249 // Function types are too different. Abort. 1250 return false; 1251 } 1252 1253 // Check argument types. 1254 for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumArgs(); 1255 ArgIdx != NumArgs; ++ArgIdx) { 1256 QualType FromArgType = FromFunctionType->getArgType(ArgIdx); 1257 QualType ToArgType = ToFunctionType->getArgType(ArgIdx); 1258 if (Context.getCanonicalType(FromArgType) 1259 == Context.getCanonicalType(ToArgType)) { 1260 // Okay, the types match exactly. Nothing to do. 1261 } else if (isObjCPointerConversion(FromArgType, ToArgType, 1262 ConvertedType, IncompatibleObjC)) { 1263 // Okay, we have an Objective-C pointer conversion. 1264 HasObjCConversion = true; 1265 } else { 1266 // Argument types are too different. Abort. 1267 return false; 1268 } 1269 } 1270 1271 if (HasObjCConversion) { 1272 // We had an Objective-C conversion. Allow this pointer 1273 // conversion, but complain about it. 1274 ConvertedType = ToType; 1275 IncompatibleObjC = true; 1276 return true; 1277 } 1278 } 1279 1280 return false; 1281} 1282 1283/// CheckPointerConversion - Check the pointer conversion from the 1284/// expression From to the type ToType. This routine checks for 1285/// ambiguous or inaccessible derived-to-base pointer 1286/// conversions for which IsPointerConversion has already returned 1287/// true. It returns true and produces a diagnostic if there was an 1288/// error, or returns false otherwise. 1289bool Sema::CheckPointerConversion(Expr *From, QualType ToType, 1290 CastExpr::CastKind &Kind, 1291 bool IgnoreBaseAccess) { 1292 QualType FromType = From->getType(); 1293 1294 if (const PointerType *FromPtrType = FromType->getAs<PointerType>()) 1295 if (const PointerType *ToPtrType = ToType->getAs<PointerType>()) { 1296 QualType FromPointeeType = FromPtrType->getPointeeType(), 1297 ToPointeeType = ToPtrType->getPointeeType(); 1298 1299 if (FromPointeeType->isRecordType() && ToPointeeType->isRecordType() && 1300 !Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType)) { 1301 // We must have a derived-to-base conversion. Check an 1302 // ambiguous or inaccessible conversion. 1303 if (CheckDerivedToBaseConversion(FromPointeeType, ToPointeeType, 1304 From->getExprLoc(), 1305 From->getSourceRange(), 1306 IgnoreBaseAccess)) 1307 return true; 1308 1309 // The conversion was successful. 1310 Kind = CastExpr::CK_DerivedToBase; 1311 } 1312 } 1313 if (const ObjCObjectPointerType *FromPtrType = 1314 FromType->getAs<ObjCObjectPointerType>()) 1315 if (const ObjCObjectPointerType *ToPtrType = 1316 ToType->getAs<ObjCObjectPointerType>()) { 1317 // Objective-C++ conversions are always okay. 1318 // FIXME: We should have a different class of conversions for the 1319 // Objective-C++ implicit conversions. 1320 if (FromPtrType->isObjCBuiltinType() || ToPtrType->isObjCBuiltinType()) 1321 return false; 1322 1323 } 1324 return false; 1325} 1326 1327/// IsMemberPointerConversion - Determines whether the conversion of the 1328/// expression From, which has the (possibly adjusted) type FromType, can be 1329/// converted to the type ToType via a member pointer conversion (C++ 4.11). 1330/// If so, returns true and places the converted type (that might differ from 1331/// ToType in its cv-qualifiers at some level) into ConvertedType. 1332bool Sema::IsMemberPointerConversion(Expr *From, QualType FromType, 1333 QualType ToType, 1334 bool InOverloadResolution, 1335 QualType &ConvertedType) { 1336 const MemberPointerType *ToTypePtr = ToType->getAs<MemberPointerType>(); 1337 if (!ToTypePtr) 1338 return false; 1339 1340 // A null pointer constant can be converted to a member pointer (C++ 4.11p1) 1341 if (From->isNullPointerConstant(Context, 1342 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull 1343 : Expr::NPC_ValueDependentIsNull)) { 1344 ConvertedType = ToType; 1345 return true; 1346 } 1347 1348 // Otherwise, both types have to be member pointers. 1349 const MemberPointerType *FromTypePtr = FromType->getAs<MemberPointerType>(); 1350 if (!FromTypePtr) 1351 return false; 1352 1353 // A pointer to member of B can be converted to a pointer to member of D, 1354 // where D is derived from B (C++ 4.11p2). 1355 QualType FromClass(FromTypePtr->getClass(), 0); 1356 QualType ToClass(ToTypePtr->getClass(), 0); 1357 // FIXME: What happens when these are dependent? Is this function even called? 1358 1359 if (IsDerivedFrom(ToClass, FromClass)) { 1360 ConvertedType = Context.getMemberPointerType(FromTypePtr->getPointeeType(), 1361 ToClass.getTypePtr()); 1362 return true; 1363 } 1364 1365 return false; 1366} 1367 1368/// CheckMemberPointerConversion - Check the member pointer conversion from the 1369/// expression From to the type ToType. This routine checks for ambiguous or 1370/// virtual or inaccessible base-to-derived member pointer conversions 1371/// for which IsMemberPointerConversion has already returned true. It returns 1372/// true and produces a diagnostic if there was an error, or returns false 1373/// otherwise. 1374bool Sema::CheckMemberPointerConversion(Expr *From, QualType ToType, 1375 CastExpr::CastKind &Kind, 1376 bool IgnoreBaseAccess) { 1377 QualType FromType = From->getType(); 1378 const MemberPointerType *FromPtrType = FromType->getAs<MemberPointerType>(); 1379 if (!FromPtrType) { 1380 // This must be a null pointer to member pointer conversion 1381 assert(From->isNullPointerConstant(Context, 1382 Expr::NPC_ValueDependentIsNull) && 1383 "Expr must be null pointer constant!"); 1384 Kind = CastExpr::CK_NullToMemberPointer; 1385 return false; 1386 } 1387 1388 const MemberPointerType *ToPtrType = ToType->getAs<MemberPointerType>(); 1389 assert(ToPtrType && "No member pointer cast has a target type " 1390 "that is not a member pointer."); 1391 1392 QualType FromClass = QualType(FromPtrType->getClass(), 0); 1393 QualType ToClass = QualType(ToPtrType->getClass(), 0); 1394 1395 // FIXME: What about dependent types? 1396 assert(FromClass->isRecordType() && "Pointer into non-class."); 1397 assert(ToClass->isRecordType() && "Pointer into non-class."); 1398 1399 CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/ true, 1400 /*DetectVirtual=*/true); 1401 bool DerivationOkay = IsDerivedFrom(ToClass, FromClass, Paths); 1402 assert(DerivationOkay && 1403 "Should not have been called if derivation isn't OK."); 1404 (void)DerivationOkay; 1405 1406 if (Paths.isAmbiguous(Context.getCanonicalType(FromClass). 1407 getUnqualifiedType())) { 1408 std::string PathDisplayStr = getAmbiguousPathsDisplayString(Paths); 1409 Diag(From->getExprLoc(), diag::err_ambiguous_memptr_conv) 1410 << 0 << FromClass << ToClass << PathDisplayStr << From->getSourceRange(); 1411 return true; 1412 } 1413 1414 if (const RecordType *VBase = Paths.getDetectedVirtual()) { 1415 Diag(From->getExprLoc(), diag::err_memptr_conv_via_virtual) 1416 << FromClass << ToClass << QualType(VBase, 0) 1417 << From->getSourceRange(); 1418 return true; 1419 } 1420 1421 if (!IgnoreBaseAccess) 1422 CheckBaseClassAccess(From->getExprLoc(), FromClass, ToClass, 1423 Paths.front(), 1424 diag::err_downcast_from_inaccessible_base); 1425 1426 // Must be a base to derived member conversion. 1427 Kind = CastExpr::CK_BaseToDerivedMemberPointer; 1428 return false; 1429} 1430 1431/// IsQualificationConversion - Determines whether the conversion from 1432/// an rvalue of type FromType to ToType is a qualification conversion 1433/// (C++ 4.4). 1434bool 1435Sema::IsQualificationConversion(QualType FromType, QualType ToType) { 1436 FromType = Context.getCanonicalType(FromType); 1437 ToType = Context.getCanonicalType(ToType); 1438 1439 // If FromType and ToType are the same type, this is not a 1440 // qualification conversion. 1441 if (FromType.getUnqualifiedType() == ToType.getUnqualifiedType()) 1442 return false; 1443 1444 // (C++ 4.4p4): 1445 // A conversion can add cv-qualifiers at levels other than the first 1446 // in multi-level pointers, subject to the following rules: [...] 1447 bool PreviousToQualsIncludeConst = true; 1448 bool UnwrappedAnyPointer = false; 1449 while (UnwrapSimilarPointerTypes(FromType, ToType)) { 1450 // Within each iteration of the loop, we check the qualifiers to 1451 // determine if this still looks like a qualification 1452 // conversion. Then, if all is well, we unwrap one more level of 1453 // pointers or pointers-to-members and do it all again 1454 // until there are no more pointers or pointers-to-members left to 1455 // unwrap. 1456 UnwrappedAnyPointer = true; 1457 1458 // -- for every j > 0, if const is in cv 1,j then const is in cv 1459 // 2,j, and similarly for volatile. 1460 if (!ToType.isAtLeastAsQualifiedAs(FromType)) 1461 return false; 1462 1463 // -- if the cv 1,j and cv 2,j are different, then const is in 1464 // every cv for 0 < k < j. 1465 if (FromType.getCVRQualifiers() != ToType.getCVRQualifiers() 1466 && !PreviousToQualsIncludeConst) 1467 return false; 1468 1469 // Keep track of whether all prior cv-qualifiers in the "to" type 1470 // include const. 1471 PreviousToQualsIncludeConst 1472 = PreviousToQualsIncludeConst && ToType.isConstQualified(); 1473 } 1474 1475 // We are left with FromType and ToType being the pointee types 1476 // after unwrapping the original FromType and ToType the same number 1477 // of types. If we unwrapped any pointers, and if FromType and 1478 // ToType have the same unqualified type (since we checked 1479 // qualifiers above), then this is a qualification conversion. 1480 return UnwrappedAnyPointer && Context.hasSameUnqualifiedType(FromType,ToType); 1481} 1482 1483/// Determines whether there is a user-defined conversion sequence 1484/// (C++ [over.ics.user]) that converts expression From to the type 1485/// ToType. If such a conversion exists, User will contain the 1486/// user-defined conversion sequence that performs such a conversion 1487/// and this routine will return true. Otherwise, this routine returns 1488/// false and User is unspecified. 1489/// 1490/// \param AllowConversionFunctions true if the conversion should 1491/// consider conversion functions at all. If false, only constructors 1492/// will be considered. 1493/// 1494/// \param AllowExplicit true if the conversion should consider C++0x 1495/// "explicit" conversion functions as well as non-explicit conversion 1496/// functions (C++0x [class.conv.fct]p2). 1497/// 1498/// \param UserCast true if looking for user defined conversion for a static 1499/// cast. 1500OverloadingResult Sema::IsUserDefinedConversion(Expr *From, QualType ToType, 1501 UserDefinedConversionSequence& User, 1502 OverloadCandidateSet& CandidateSet, 1503 bool AllowConversionFunctions, 1504 bool AllowExplicit, 1505 bool UserCast) { 1506 if (const RecordType *ToRecordType = ToType->getAs<RecordType>()) { 1507 if (RequireCompleteType(From->getLocStart(), ToType, PDiag())) { 1508 // We're not going to find any constructors. 1509 } else if (CXXRecordDecl *ToRecordDecl 1510 = dyn_cast<CXXRecordDecl>(ToRecordType->getDecl())) { 1511 // C++ [over.match.ctor]p1: 1512 // When objects of class type are direct-initialized (8.5), or 1513 // copy-initialized from an expression of the same or a 1514 // derived class type (8.5), overload resolution selects the 1515 // constructor. [...] For copy-initialization, the candidate 1516 // functions are all the converting constructors (12.3.1) of 1517 // that class. The argument list is the expression-list within 1518 // the parentheses of the initializer. 1519 bool SuppressUserConversions = !UserCast; 1520 if (Context.hasSameUnqualifiedType(ToType, From->getType()) || 1521 IsDerivedFrom(From->getType(), ToType)) { 1522 SuppressUserConversions = false; 1523 AllowConversionFunctions = false; 1524 } 1525 1526 DeclarationName ConstructorName 1527 = Context.DeclarationNames.getCXXConstructorName( 1528 Context.getCanonicalType(ToType).getUnqualifiedType()); 1529 DeclContext::lookup_iterator Con, ConEnd; 1530 for (llvm::tie(Con, ConEnd) 1531 = ToRecordDecl->lookup(ConstructorName); 1532 Con != ConEnd; ++Con) { 1533 NamedDecl *D = *Con; 1534 DeclAccessPair FoundDecl = DeclAccessPair::make(D, D->getAccess()); 1535 1536 // Find the constructor (which may be a template). 1537 CXXConstructorDecl *Constructor = 0; 1538 FunctionTemplateDecl *ConstructorTmpl 1539 = dyn_cast<FunctionTemplateDecl>(D); 1540 if (ConstructorTmpl) 1541 Constructor 1542 = cast<CXXConstructorDecl>(ConstructorTmpl->getTemplatedDecl()); 1543 else 1544 Constructor = cast<CXXConstructorDecl>(D); 1545 1546 if (!Constructor->isInvalidDecl() && 1547 Constructor->isConvertingConstructor(AllowExplicit)) { 1548 if (ConstructorTmpl) 1549 AddTemplateOverloadCandidate(ConstructorTmpl, FoundDecl, 1550 /*ExplicitArgs*/ 0, 1551 &From, 1, CandidateSet, 1552 SuppressUserConversions); 1553 else 1554 // Allow one user-defined conversion when user specifies a 1555 // From->ToType conversion via an static cast (c-style, etc). 1556 AddOverloadCandidate(Constructor, FoundDecl, 1557 &From, 1, CandidateSet, 1558 SuppressUserConversions); 1559 } 1560 } 1561 } 1562 } 1563 1564 if (!AllowConversionFunctions) { 1565 // Don't allow any conversion functions to enter the overload set. 1566 } else if (RequireCompleteType(From->getLocStart(), From->getType(), 1567 PDiag(0) 1568 << From->getSourceRange())) { 1569 // No conversion functions from incomplete types. 1570 } else if (const RecordType *FromRecordType 1571 = From->getType()->getAs<RecordType>()) { 1572 if (CXXRecordDecl *FromRecordDecl 1573 = dyn_cast<CXXRecordDecl>(FromRecordType->getDecl())) { 1574 // Add all of the conversion functions as candidates. 1575 const UnresolvedSetImpl *Conversions 1576 = FromRecordDecl->getVisibleConversionFunctions(); 1577 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 1578 E = Conversions->end(); I != E; ++I) { 1579 DeclAccessPair FoundDecl = I.getPair(); 1580 NamedDecl *D = FoundDecl.getDecl(); 1581 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext()); 1582 if (isa<UsingShadowDecl>(D)) 1583 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 1584 1585 CXXConversionDecl *Conv; 1586 FunctionTemplateDecl *ConvTemplate; 1587 if ((ConvTemplate = dyn_cast<FunctionTemplateDecl>(D))) 1588 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 1589 else 1590 Conv = cast<CXXConversionDecl>(D); 1591 1592 if (AllowExplicit || !Conv->isExplicit()) { 1593 if (ConvTemplate) 1594 AddTemplateConversionCandidate(ConvTemplate, FoundDecl, 1595 ActingContext, From, ToType, 1596 CandidateSet); 1597 else 1598 AddConversionCandidate(Conv, FoundDecl, ActingContext, 1599 From, ToType, CandidateSet); 1600 } 1601 } 1602 } 1603 } 1604 1605 OverloadCandidateSet::iterator Best; 1606 switch (BestViableFunction(CandidateSet, From->getLocStart(), Best)) { 1607 case OR_Success: 1608 // Record the standard conversion we used and the conversion function. 1609 if (CXXConstructorDecl *Constructor 1610 = dyn_cast<CXXConstructorDecl>(Best->Function)) { 1611 // C++ [over.ics.user]p1: 1612 // If the user-defined conversion is specified by a 1613 // constructor (12.3.1), the initial standard conversion 1614 // sequence converts the source type to the type required by 1615 // the argument of the constructor. 1616 // 1617 QualType ThisType = Constructor->getThisType(Context); 1618 if (Best->Conversions[0].isEllipsis()) 1619 User.EllipsisConversion = true; 1620 else { 1621 User.Before = Best->Conversions[0].Standard; 1622 User.EllipsisConversion = false; 1623 } 1624 User.ConversionFunction = Constructor; 1625 User.After.setAsIdentityConversion(); 1626 User.After.setFromType( 1627 ThisType->getAs<PointerType>()->getPointeeType()); 1628 User.After.setAllToTypes(ToType); 1629 return OR_Success; 1630 } else if (CXXConversionDecl *Conversion 1631 = dyn_cast<CXXConversionDecl>(Best->Function)) { 1632 // C++ [over.ics.user]p1: 1633 // 1634 // [...] If the user-defined conversion is specified by a 1635 // conversion function (12.3.2), the initial standard 1636 // conversion sequence converts the source type to the 1637 // implicit object parameter of the conversion function. 1638 User.Before = Best->Conversions[0].Standard; 1639 User.ConversionFunction = Conversion; 1640 User.EllipsisConversion = false; 1641 1642 // C++ [over.ics.user]p2: 1643 // The second standard conversion sequence converts the 1644 // result of the user-defined conversion to the target type 1645 // for the sequence. Since an implicit conversion sequence 1646 // is an initialization, the special rules for 1647 // initialization by user-defined conversion apply when 1648 // selecting the best user-defined conversion for a 1649 // user-defined conversion sequence (see 13.3.3 and 1650 // 13.3.3.1). 1651 User.After = Best->FinalConversion; 1652 return OR_Success; 1653 } else { 1654 assert(false && "Not a constructor or conversion function?"); 1655 return OR_No_Viable_Function; 1656 } 1657 1658 case OR_No_Viable_Function: 1659 return OR_No_Viable_Function; 1660 case OR_Deleted: 1661 // No conversion here! We're done. 1662 return OR_Deleted; 1663 1664 case OR_Ambiguous: 1665 return OR_Ambiguous; 1666 } 1667 1668 return OR_No_Viable_Function; 1669} 1670 1671bool 1672Sema::DiagnoseMultipleUserDefinedConversion(Expr *From, QualType ToType) { 1673 ImplicitConversionSequence ICS; 1674 OverloadCandidateSet CandidateSet(From->getExprLoc()); 1675 OverloadingResult OvResult = 1676 IsUserDefinedConversion(From, ToType, ICS.UserDefined, 1677 CandidateSet, true, false, false); 1678 if (OvResult == OR_Ambiguous) 1679 Diag(From->getSourceRange().getBegin(), 1680 diag::err_typecheck_ambiguous_condition) 1681 << From->getType() << ToType << From->getSourceRange(); 1682 else if (OvResult == OR_No_Viable_Function && !CandidateSet.empty()) 1683 Diag(From->getSourceRange().getBegin(), 1684 diag::err_typecheck_nonviable_condition) 1685 << From->getType() << ToType << From->getSourceRange(); 1686 else 1687 return false; 1688 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, &From, 1); 1689 return true; 1690} 1691 1692/// CompareImplicitConversionSequences - Compare two implicit 1693/// conversion sequences to determine whether one is better than the 1694/// other or if they are indistinguishable (C++ 13.3.3.2). 1695ImplicitConversionSequence::CompareKind 1696Sema::CompareImplicitConversionSequences(const ImplicitConversionSequence& ICS1, 1697 const ImplicitConversionSequence& ICS2) 1698{ 1699 // (C++ 13.3.3.2p2): When comparing the basic forms of implicit 1700 // conversion sequences (as defined in 13.3.3.1) 1701 // -- a standard conversion sequence (13.3.3.1.1) is a better 1702 // conversion sequence than a user-defined conversion sequence or 1703 // an ellipsis conversion sequence, and 1704 // -- a user-defined conversion sequence (13.3.3.1.2) is a better 1705 // conversion sequence than an ellipsis conversion sequence 1706 // (13.3.3.1.3). 1707 // 1708 // C++0x [over.best.ics]p10: 1709 // For the purpose of ranking implicit conversion sequences as 1710 // described in 13.3.3.2, the ambiguous conversion sequence is 1711 // treated as a user-defined sequence that is indistinguishable 1712 // from any other user-defined conversion sequence. 1713 if (ICS1.getKind() < ICS2.getKind()) { 1714 if (!(ICS1.isUserDefined() && ICS2.isAmbiguous())) 1715 return ImplicitConversionSequence::Better; 1716 } else if (ICS2.getKind() < ICS1.getKind()) { 1717 if (!(ICS2.isUserDefined() && ICS1.isAmbiguous())) 1718 return ImplicitConversionSequence::Worse; 1719 } 1720 1721 if (ICS1.isAmbiguous() || ICS2.isAmbiguous()) 1722 return ImplicitConversionSequence::Indistinguishable; 1723 1724 // Two implicit conversion sequences of the same form are 1725 // indistinguishable conversion sequences unless one of the 1726 // following rules apply: (C++ 13.3.3.2p3): 1727 if (ICS1.isStandard()) 1728 return CompareStandardConversionSequences(ICS1.Standard, ICS2.Standard); 1729 else if (ICS1.isUserDefined()) { 1730 // User-defined conversion sequence U1 is a better conversion 1731 // sequence than another user-defined conversion sequence U2 if 1732 // they contain the same user-defined conversion function or 1733 // constructor and if the second standard conversion sequence of 1734 // U1 is better than the second standard conversion sequence of 1735 // U2 (C++ 13.3.3.2p3). 1736 if (ICS1.UserDefined.ConversionFunction == 1737 ICS2.UserDefined.ConversionFunction) 1738 return CompareStandardConversionSequences(ICS1.UserDefined.After, 1739 ICS2.UserDefined.After); 1740 } 1741 1742 return ImplicitConversionSequence::Indistinguishable; 1743} 1744 1745// Per 13.3.3.2p3, compare the given standard conversion sequences to 1746// determine if one is a proper subset of the other. 1747static ImplicitConversionSequence::CompareKind 1748compareStandardConversionSubsets(ASTContext &Context, 1749 const StandardConversionSequence& SCS1, 1750 const StandardConversionSequence& SCS2) { 1751 ImplicitConversionSequence::CompareKind Result 1752 = ImplicitConversionSequence::Indistinguishable; 1753 1754 if (SCS1.Second != SCS2.Second) { 1755 if (SCS1.Second == ICK_Identity) 1756 Result = ImplicitConversionSequence::Better; 1757 else if (SCS2.Second == ICK_Identity) 1758 Result = ImplicitConversionSequence::Worse; 1759 else 1760 return ImplicitConversionSequence::Indistinguishable; 1761 } else if (!Context.hasSameType(SCS1.getToType(1), SCS2.getToType(1))) 1762 return ImplicitConversionSequence::Indistinguishable; 1763 1764 if (SCS1.Third == SCS2.Third) { 1765 return Context.hasSameType(SCS1.getToType(2), SCS2.getToType(2))? Result 1766 : ImplicitConversionSequence::Indistinguishable; 1767 } 1768 1769 if (SCS1.Third == ICK_Identity) 1770 return Result == ImplicitConversionSequence::Worse 1771 ? ImplicitConversionSequence::Indistinguishable 1772 : ImplicitConversionSequence::Better; 1773 1774 if (SCS2.Third == ICK_Identity) 1775 return Result == ImplicitConversionSequence::Better 1776 ? ImplicitConversionSequence::Indistinguishable 1777 : ImplicitConversionSequence::Worse; 1778 1779 return ImplicitConversionSequence::Indistinguishable; 1780} 1781 1782/// CompareStandardConversionSequences - Compare two standard 1783/// conversion sequences to determine whether one is better than the 1784/// other or if they are indistinguishable (C++ 13.3.3.2p3). 1785ImplicitConversionSequence::CompareKind 1786Sema::CompareStandardConversionSequences(const StandardConversionSequence& SCS1, 1787 const StandardConversionSequence& SCS2) 1788{ 1789 // Standard conversion sequence S1 is a better conversion sequence 1790 // than standard conversion sequence S2 if (C++ 13.3.3.2p3): 1791 1792 // -- S1 is a proper subsequence of S2 (comparing the conversion 1793 // sequences in the canonical form defined by 13.3.3.1.1, 1794 // excluding any Lvalue Transformation; the identity conversion 1795 // sequence is considered to be a subsequence of any 1796 // non-identity conversion sequence) or, if not that, 1797 if (ImplicitConversionSequence::CompareKind CK 1798 = compareStandardConversionSubsets(Context, SCS1, SCS2)) 1799 return CK; 1800 1801 // -- the rank of S1 is better than the rank of S2 (by the rules 1802 // defined below), or, if not that, 1803 ImplicitConversionRank Rank1 = SCS1.getRank(); 1804 ImplicitConversionRank Rank2 = SCS2.getRank(); 1805 if (Rank1 < Rank2) 1806 return ImplicitConversionSequence::Better; 1807 else if (Rank2 < Rank1) 1808 return ImplicitConversionSequence::Worse; 1809 1810 // (C++ 13.3.3.2p4): Two conversion sequences with the same rank 1811 // are indistinguishable unless one of the following rules 1812 // applies: 1813 1814 // A conversion that is not a conversion of a pointer, or 1815 // pointer to member, to bool is better than another conversion 1816 // that is such a conversion. 1817 if (SCS1.isPointerConversionToBool() != SCS2.isPointerConversionToBool()) 1818 return SCS2.isPointerConversionToBool() 1819 ? ImplicitConversionSequence::Better 1820 : ImplicitConversionSequence::Worse; 1821 1822 // C++ [over.ics.rank]p4b2: 1823 // 1824 // If class B is derived directly or indirectly from class A, 1825 // conversion of B* to A* is better than conversion of B* to 1826 // void*, and conversion of A* to void* is better than conversion 1827 // of B* to void*. 1828 bool SCS1ConvertsToVoid 1829 = SCS1.isPointerConversionToVoidPointer(Context); 1830 bool SCS2ConvertsToVoid 1831 = SCS2.isPointerConversionToVoidPointer(Context); 1832 if (SCS1ConvertsToVoid != SCS2ConvertsToVoid) { 1833 // Exactly one of the conversion sequences is a conversion to 1834 // a void pointer; it's the worse conversion. 1835 return SCS2ConvertsToVoid ? ImplicitConversionSequence::Better 1836 : ImplicitConversionSequence::Worse; 1837 } else if (!SCS1ConvertsToVoid && !SCS2ConvertsToVoid) { 1838 // Neither conversion sequence converts to a void pointer; compare 1839 // their derived-to-base conversions. 1840 if (ImplicitConversionSequence::CompareKind DerivedCK 1841 = CompareDerivedToBaseConversions(SCS1, SCS2)) 1842 return DerivedCK; 1843 } else if (SCS1ConvertsToVoid && SCS2ConvertsToVoid) { 1844 // Both conversion sequences are conversions to void 1845 // pointers. Compare the source types to determine if there's an 1846 // inheritance relationship in their sources. 1847 QualType FromType1 = SCS1.getFromType(); 1848 QualType FromType2 = SCS2.getFromType(); 1849 1850 // Adjust the types we're converting from via the array-to-pointer 1851 // conversion, if we need to. 1852 if (SCS1.First == ICK_Array_To_Pointer) 1853 FromType1 = Context.getArrayDecayedType(FromType1); 1854 if (SCS2.First == ICK_Array_To_Pointer) 1855 FromType2 = Context.getArrayDecayedType(FromType2); 1856 1857 QualType FromPointee1 1858 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1859 QualType FromPointee2 1860 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1861 1862 if (IsDerivedFrom(FromPointee2, FromPointee1)) 1863 return ImplicitConversionSequence::Better; 1864 else if (IsDerivedFrom(FromPointee1, FromPointee2)) 1865 return ImplicitConversionSequence::Worse; 1866 1867 // Objective-C++: If one interface is more specific than the 1868 // other, it is the better one. 1869 const ObjCInterfaceType* FromIface1 = FromPointee1->getAs<ObjCInterfaceType>(); 1870 const ObjCInterfaceType* FromIface2 = FromPointee2->getAs<ObjCInterfaceType>(); 1871 if (FromIface1 && FromIface1) { 1872 if (Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 1873 return ImplicitConversionSequence::Better; 1874 else if (Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 1875 return ImplicitConversionSequence::Worse; 1876 } 1877 } 1878 1879 // Compare based on qualification conversions (C++ 13.3.3.2p3, 1880 // bullet 3). 1881 if (ImplicitConversionSequence::CompareKind QualCK 1882 = CompareQualificationConversions(SCS1, SCS2)) 1883 return QualCK; 1884 1885 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding) { 1886 // C++0x [over.ics.rank]p3b4: 1887 // -- S1 and S2 are reference bindings (8.5.3) and neither refers to an 1888 // implicit object parameter of a non-static member function declared 1889 // without a ref-qualifier, and S1 binds an rvalue reference to an 1890 // rvalue and S2 binds an lvalue reference. 1891 // FIXME: We don't know if we're dealing with the implicit object parameter, 1892 // or if the member function in this case has a ref qualifier. 1893 // (Of course, we don't have ref qualifiers yet.) 1894 if (SCS1.RRefBinding != SCS2.RRefBinding) 1895 return SCS1.RRefBinding ? ImplicitConversionSequence::Better 1896 : ImplicitConversionSequence::Worse; 1897 1898 // C++ [over.ics.rank]p3b4: 1899 // -- S1 and S2 are reference bindings (8.5.3), and the types to 1900 // which the references refer are the same type except for 1901 // top-level cv-qualifiers, and the type to which the reference 1902 // initialized by S2 refers is more cv-qualified than the type 1903 // to which the reference initialized by S1 refers. 1904 QualType T1 = SCS1.getToType(2); 1905 QualType T2 = SCS2.getToType(2); 1906 T1 = Context.getCanonicalType(T1); 1907 T2 = Context.getCanonicalType(T2); 1908 Qualifiers T1Quals, T2Quals; 1909 QualType UnqualT1 = Context.getUnqualifiedArrayType(T1, T1Quals); 1910 QualType UnqualT2 = Context.getUnqualifiedArrayType(T2, T2Quals); 1911 if (UnqualT1 == UnqualT2) { 1912 // If the type is an array type, promote the element qualifiers to the type 1913 // for comparison. 1914 if (isa<ArrayType>(T1) && T1Quals) 1915 T1 = Context.getQualifiedType(UnqualT1, T1Quals); 1916 if (isa<ArrayType>(T2) && T2Quals) 1917 T2 = Context.getQualifiedType(UnqualT2, T2Quals); 1918 if (T2.isMoreQualifiedThan(T1)) 1919 return ImplicitConversionSequence::Better; 1920 else if (T1.isMoreQualifiedThan(T2)) 1921 return ImplicitConversionSequence::Worse; 1922 } 1923 } 1924 1925 return ImplicitConversionSequence::Indistinguishable; 1926} 1927 1928/// CompareQualificationConversions - Compares two standard conversion 1929/// sequences to determine whether they can be ranked based on their 1930/// qualification conversions (C++ 13.3.3.2p3 bullet 3). 1931ImplicitConversionSequence::CompareKind 1932Sema::CompareQualificationConversions(const StandardConversionSequence& SCS1, 1933 const StandardConversionSequence& SCS2) { 1934 // C++ 13.3.3.2p3: 1935 // -- S1 and S2 differ only in their qualification conversion and 1936 // yield similar types T1 and T2 (C++ 4.4), respectively, and the 1937 // cv-qualification signature of type T1 is a proper subset of 1938 // the cv-qualification signature of type T2, and S1 is not the 1939 // deprecated string literal array-to-pointer conversion (4.2). 1940 if (SCS1.First != SCS2.First || SCS1.Second != SCS2.Second || 1941 SCS1.Third != SCS2.Third || SCS1.Third != ICK_Qualification) 1942 return ImplicitConversionSequence::Indistinguishable; 1943 1944 // FIXME: the example in the standard doesn't use a qualification 1945 // conversion (!) 1946 QualType T1 = SCS1.getToType(2); 1947 QualType T2 = SCS2.getToType(2); 1948 T1 = Context.getCanonicalType(T1); 1949 T2 = Context.getCanonicalType(T2); 1950 Qualifiers T1Quals, T2Quals; 1951 QualType UnqualT1 = Context.getUnqualifiedArrayType(T1, T1Quals); 1952 QualType UnqualT2 = Context.getUnqualifiedArrayType(T2, T2Quals); 1953 1954 // If the types are the same, we won't learn anything by unwrapped 1955 // them. 1956 if (UnqualT1 == UnqualT2) 1957 return ImplicitConversionSequence::Indistinguishable; 1958 1959 // If the type is an array type, promote the element qualifiers to the type 1960 // for comparison. 1961 if (isa<ArrayType>(T1) && T1Quals) 1962 T1 = Context.getQualifiedType(UnqualT1, T1Quals); 1963 if (isa<ArrayType>(T2) && T2Quals) 1964 T2 = Context.getQualifiedType(UnqualT2, T2Quals); 1965 1966 ImplicitConversionSequence::CompareKind Result 1967 = ImplicitConversionSequence::Indistinguishable; 1968 while (UnwrapSimilarPointerTypes(T1, T2)) { 1969 // Within each iteration of the loop, we check the qualifiers to 1970 // determine if this still looks like a qualification 1971 // conversion. Then, if all is well, we unwrap one more level of 1972 // pointers or pointers-to-members and do it all again 1973 // until there are no more pointers or pointers-to-members left 1974 // to unwrap. This essentially mimics what 1975 // IsQualificationConversion does, but here we're checking for a 1976 // strict subset of qualifiers. 1977 if (T1.getCVRQualifiers() == T2.getCVRQualifiers()) 1978 // The qualifiers are the same, so this doesn't tell us anything 1979 // about how the sequences rank. 1980 ; 1981 else if (T2.isMoreQualifiedThan(T1)) { 1982 // T1 has fewer qualifiers, so it could be the better sequence. 1983 if (Result == ImplicitConversionSequence::Worse) 1984 // Neither has qualifiers that are a subset of the other's 1985 // qualifiers. 1986 return ImplicitConversionSequence::Indistinguishable; 1987 1988 Result = ImplicitConversionSequence::Better; 1989 } else if (T1.isMoreQualifiedThan(T2)) { 1990 // T2 has fewer qualifiers, so it could be the better sequence. 1991 if (Result == ImplicitConversionSequence::Better) 1992 // Neither has qualifiers that are a subset of the other's 1993 // qualifiers. 1994 return ImplicitConversionSequence::Indistinguishable; 1995 1996 Result = ImplicitConversionSequence::Worse; 1997 } else { 1998 // Qualifiers are disjoint. 1999 return ImplicitConversionSequence::Indistinguishable; 2000 } 2001 2002 // If the types after this point are equivalent, we're done. 2003 if (Context.hasSameUnqualifiedType(T1, T2)) 2004 break; 2005 } 2006 2007 // Check that the winning standard conversion sequence isn't using 2008 // the deprecated string literal array to pointer conversion. 2009 switch (Result) { 2010 case ImplicitConversionSequence::Better: 2011 if (SCS1.DeprecatedStringLiteralToCharPtr) 2012 Result = ImplicitConversionSequence::Indistinguishable; 2013 break; 2014 2015 case ImplicitConversionSequence::Indistinguishable: 2016 break; 2017 2018 case ImplicitConversionSequence::Worse: 2019 if (SCS2.DeprecatedStringLiteralToCharPtr) 2020 Result = ImplicitConversionSequence::Indistinguishable; 2021 break; 2022 } 2023 2024 return Result; 2025} 2026 2027/// CompareDerivedToBaseConversions - Compares two standard conversion 2028/// sequences to determine whether they can be ranked based on their 2029/// various kinds of derived-to-base conversions (C++ 2030/// [over.ics.rank]p4b3). As part of these checks, we also look at 2031/// conversions between Objective-C interface types. 2032ImplicitConversionSequence::CompareKind 2033Sema::CompareDerivedToBaseConversions(const StandardConversionSequence& SCS1, 2034 const StandardConversionSequence& SCS2) { 2035 QualType FromType1 = SCS1.getFromType(); 2036 QualType ToType1 = SCS1.getToType(1); 2037 QualType FromType2 = SCS2.getFromType(); 2038 QualType ToType2 = SCS2.getToType(1); 2039 2040 // Adjust the types we're converting from via the array-to-pointer 2041 // conversion, if we need to. 2042 if (SCS1.First == ICK_Array_To_Pointer) 2043 FromType1 = Context.getArrayDecayedType(FromType1); 2044 if (SCS2.First == ICK_Array_To_Pointer) 2045 FromType2 = Context.getArrayDecayedType(FromType2); 2046 2047 // Canonicalize all of the types. 2048 FromType1 = Context.getCanonicalType(FromType1); 2049 ToType1 = Context.getCanonicalType(ToType1); 2050 FromType2 = Context.getCanonicalType(FromType2); 2051 ToType2 = Context.getCanonicalType(ToType2); 2052 2053 // C++ [over.ics.rank]p4b3: 2054 // 2055 // If class B is derived directly or indirectly from class A and 2056 // class C is derived directly or indirectly from B, 2057 // 2058 // For Objective-C, we let A, B, and C also be Objective-C 2059 // interfaces. 2060 2061 // Compare based on pointer conversions. 2062 if (SCS1.Second == ICK_Pointer_Conversion && 2063 SCS2.Second == ICK_Pointer_Conversion && 2064 /*FIXME: Remove if Objective-C id conversions get their own rank*/ 2065 FromType1->isPointerType() && FromType2->isPointerType() && 2066 ToType1->isPointerType() && ToType2->isPointerType()) { 2067 QualType FromPointee1 2068 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2069 QualType ToPointee1 2070 = ToType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2071 QualType FromPointee2 2072 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2073 QualType ToPointee2 2074 = ToType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2075 2076 const ObjCInterfaceType* FromIface1 = FromPointee1->getAs<ObjCInterfaceType>(); 2077 const ObjCInterfaceType* FromIface2 = FromPointee2->getAs<ObjCInterfaceType>(); 2078 const ObjCInterfaceType* ToIface1 = ToPointee1->getAs<ObjCInterfaceType>(); 2079 const ObjCInterfaceType* ToIface2 = ToPointee2->getAs<ObjCInterfaceType>(); 2080 2081 // -- conversion of C* to B* is better than conversion of C* to A*, 2082 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 2083 if (IsDerivedFrom(ToPointee1, ToPointee2)) 2084 return ImplicitConversionSequence::Better; 2085 else if (IsDerivedFrom(ToPointee2, ToPointee1)) 2086 return ImplicitConversionSequence::Worse; 2087 2088 if (ToIface1 && ToIface2) { 2089 if (Context.canAssignObjCInterfaces(ToIface2, ToIface1)) 2090 return ImplicitConversionSequence::Better; 2091 else if (Context.canAssignObjCInterfaces(ToIface1, ToIface2)) 2092 return ImplicitConversionSequence::Worse; 2093 } 2094 } 2095 2096 // -- conversion of B* to A* is better than conversion of C* to A*, 2097 if (FromPointee1 != FromPointee2 && ToPointee1 == ToPointee2) { 2098 if (IsDerivedFrom(FromPointee2, FromPointee1)) 2099 return ImplicitConversionSequence::Better; 2100 else if (IsDerivedFrom(FromPointee1, FromPointee2)) 2101 return ImplicitConversionSequence::Worse; 2102 2103 if (FromIface1 && FromIface2) { 2104 if (Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 2105 return ImplicitConversionSequence::Better; 2106 else if (Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 2107 return ImplicitConversionSequence::Worse; 2108 } 2109 } 2110 } 2111 2112 // Ranking of member-pointer types. 2113 if (SCS1.Second == ICK_Pointer_Member && SCS2.Second == ICK_Pointer_Member && 2114 FromType1->isMemberPointerType() && FromType2->isMemberPointerType() && 2115 ToType1->isMemberPointerType() && ToType2->isMemberPointerType()) { 2116 const MemberPointerType * FromMemPointer1 = 2117 FromType1->getAs<MemberPointerType>(); 2118 const MemberPointerType * ToMemPointer1 = 2119 ToType1->getAs<MemberPointerType>(); 2120 const MemberPointerType * FromMemPointer2 = 2121 FromType2->getAs<MemberPointerType>(); 2122 const MemberPointerType * ToMemPointer2 = 2123 ToType2->getAs<MemberPointerType>(); 2124 const Type *FromPointeeType1 = FromMemPointer1->getClass(); 2125 const Type *ToPointeeType1 = ToMemPointer1->getClass(); 2126 const Type *FromPointeeType2 = FromMemPointer2->getClass(); 2127 const Type *ToPointeeType2 = ToMemPointer2->getClass(); 2128 QualType FromPointee1 = QualType(FromPointeeType1, 0).getUnqualifiedType(); 2129 QualType ToPointee1 = QualType(ToPointeeType1, 0).getUnqualifiedType(); 2130 QualType FromPointee2 = QualType(FromPointeeType2, 0).getUnqualifiedType(); 2131 QualType ToPointee2 = QualType(ToPointeeType2, 0).getUnqualifiedType(); 2132 // conversion of A::* to B::* is better than conversion of A::* to C::*, 2133 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 2134 if (IsDerivedFrom(ToPointee1, ToPointee2)) 2135 return ImplicitConversionSequence::Worse; 2136 else if (IsDerivedFrom(ToPointee2, ToPointee1)) 2137 return ImplicitConversionSequence::Better; 2138 } 2139 // conversion of B::* to C::* is better than conversion of A::* to C::* 2140 if (ToPointee1 == ToPointee2 && FromPointee1 != FromPointee2) { 2141 if (IsDerivedFrom(FromPointee1, FromPointee2)) 2142 return ImplicitConversionSequence::Better; 2143 else if (IsDerivedFrom(FromPointee2, FromPointee1)) 2144 return ImplicitConversionSequence::Worse; 2145 } 2146 } 2147 2148 if ((SCS1.ReferenceBinding || SCS1.CopyConstructor) && 2149 (SCS2.ReferenceBinding || SCS2.CopyConstructor) && 2150 SCS1.Second == ICK_Derived_To_Base) { 2151 // -- conversion of C to B is better than conversion of C to A, 2152 // -- binding of an expression of type C to a reference of type 2153 // B& is better than binding an expression of type C to a 2154 // reference of type A&, 2155 if (Context.hasSameUnqualifiedType(FromType1, FromType2) && 2156 !Context.hasSameUnqualifiedType(ToType1, ToType2)) { 2157 if (IsDerivedFrom(ToType1, ToType2)) 2158 return ImplicitConversionSequence::Better; 2159 else if (IsDerivedFrom(ToType2, ToType1)) 2160 return ImplicitConversionSequence::Worse; 2161 } 2162 2163 // -- conversion of B to A is better than conversion of C to A. 2164 // -- binding of an expression of type B to a reference of type 2165 // A& is better than binding an expression of type C to a 2166 // reference of type A&, 2167 if (!Context.hasSameUnqualifiedType(FromType1, FromType2) && 2168 Context.hasSameUnqualifiedType(ToType1, ToType2)) { 2169 if (IsDerivedFrom(FromType2, FromType1)) 2170 return ImplicitConversionSequence::Better; 2171 else if (IsDerivedFrom(FromType1, FromType2)) 2172 return ImplicitConversionSequence::Worse; 2173 } 2174 } 2175 2176 return ImplicitConversionSequence::Indistinguishable; 2177} 2178 2179/// CompareReferenceRelationship - Compare the two types T1 and T2 to 2180/// determine whether they are reference-related, 2181/// reference-compatible, reference-compatible with added 2182/// qualification, or incompatible, for use in C++ initialization by 2183/// reference (C++ [dcl.ref.init]p4). Neither type can be a reference 2184/// type, and the first type (T1) is the pointee type of the reference 2185/// type being initialized. 2186Sema::ReferenceCompareResult 2187Sema::CompareReferenceRelationship(SourceLocation Loc, 2188 QualType OrigT1, QualType OrigT2, 2189 bool& DerivedToBase) { 2190 assert(!OrigT1->isReferenceType() && 2191 "T1 must be the pointee type of the reference type"); 2192 assert(!OrigT2->isReferenceType() && "T2 cannot be a reference type"); 2193 2194 QualType T1 = Context.getCanonicalType(OrigT1); 2195 QualType T2 = Context.getCanonicalType(OrigT2); 2196 Qualifiers T1Quals, T2Quals; 2197 QualType UnqualT1 = Context.getUnqualifiedArrayType(T1, T1Quals); 2198 QualType UnqualT2 = Context.getUnqualifiedArrayType(T2, T2Quals); 2199 2200 // C++ [dcl.init.ref]p4: 2201 // Given types "cv1 T1" and "cv2 T2," "cv1 T1" is 2202 // reference-related to "cv2 T2" if T1 is the same type as T2, or 2203 // T1 is a base class of T2. 2204 if (UnqualT1 == UnqualT2) 2205 DerivedToBase = false; 2206 else if (!RequireCompleteType(Loc, OrigT1, PDiag()) && 2207 !RequireCompleteType(Loc, OrigT2, PDiag()) && 2208 IsDerivedFrom(UnqualT2, UnqualT1)) 2209 DerivedToBase = true; 2210 else 2211 return Ref_Incompatible; 2212 2213 // At this point, we know that T1 and T2 are reference-related (at 2214 // least). 2215 2216 // If the type is an array type, promote the element qualifiers to the type 2217 // for comparison. 2218 if (isa<ArrayType>(T1) && T1Quals) 2219 T1 = Context.getQualifiedType(UnqualT1, T1Quals); 2220 if (isa<ArrayType>(T2) && T2Quals) 2221 T2 = Context.getQualifiedType(UnqualT2, T2Quals); 2222 2223 // C++ [dcl.init.ref]p4: 2224 // "cv1 T1" is reference-compatible with "cv2 T2" if T1 is 2225 // reference-related to T2 and cv1 is the same cv-qualification 2226 // as, or greater cv-qualification than, cv2. For purposes of 2227 // overload resolution, cases for which cv1 is greater 2228 // cv-qualification than cv2 are identified as 2229 // reference-compatible with added qualification (see 13.3.3.2). 2230 if (T1Quals.getCVRQualifiers() == T2Quals.getCVRQualifiers()) 2231 return Ref_Compatible; 2232 else if (T1.isMoreQualifiedThan(T2)) 2233 return Ref_Compatible_With_Added_Qualification; 2234 else 2235 return Ref_Related; 2236} 2237 2238/// \brief Compute an implicit conversion sequence for reference 2239/// initialization. 2240static ImplicitConversionSequence 2241TryReferenceInit(Sema &S, Expr *&Init, QualType DeclType, 2242 SourceLocation DeclLoc, 2243 bool SuppressUserConversions, 2244 bool AllowExplicit) { 2245 assert(DeclType->isReferenceType() && "Reference init needs a reference"); 2246 2247 // Most paths end in a failed conversion. 2248 ImplicitConversionSequence ICS; 2249 ICS.setBad(BadConversionSequence::no_conversion, Init, DeclType); 2250 2251 QualType T1 = DeclType->getAs<ReferenceType>()->getPointeeType(); 2252 QualType T2 = Init->getType(); 2253 2254 // If the initializer is the address of an overloaded function, try 2255 // to resolve the overloaded function. If all goes well, T2 is the 2256 // type of the resulting function. 2257 if (S.Context.getCanonicalType(T2) == S.Context.OverloadTy) { 2258 DeclAccessPair Found; 2259 if (FunctionDecl *Fn = S.ResolveAddressOfOverloadedFunction(Init, DeclType, 2260 false, Found)) 2261 T2 = Fn->getType(); 2262 } 2263 2264 // Compute some basic properties of the types and the initializer. 2265 bool isRValRef = DeclType->isRValueReferenceType(); 2266 bool DerivedToBase = false; 2267 Expr::isLvalueResult InitLvalue = Init->isLvalue(S.Context); 2268 Sema::ReferenceCompareResult RefRelationship 2269 = S.CompareReferenceRelationship(DeclLoc, T1, T2, DerivedToBase); 2270 2271 // C++ [dcl.init.ref]p5: 2272 // A reference to type "cv1 T1" is initialized by an expression 2273 // of type "cv2 T2" as follows: 2274 2275 // -- If the initializer expression 2276 2277 // C++ [over.ics.ref]p3: 2278 // Except for an implicit object parameter, for which see 13.3.1, 2279 // a standard conversion sequence cannot be formed if it requires 2280 // binding an lvalue reference to non-const to an rvalue or 2281 // binding an rvalue reference to an lvalue. 2282 if (isRValRef && InitLvalue == Expr::LV_Valid) 2283 return ICS; 2284 2285 // -- is an lvalue (but is not a bit-field), and "cv1 T1" is 2286 // reference-compatible with "cv2 T2," or 2287 // 2288 // Per C++ [over.ics.ref]p4, we don't check the bit-field property here. 2289 if (InitLvalue == Expr::LV_Valid && 2290 RefRelationship >= Sema::Ref_Compatible_With_Added_Qualification) { 2291 // C++ [over.ics.ref]p1: 2292 // When a parameter of reference type binds directly (8.5.3) 2293 // to an argument expression, the implicit conversion sequence 2294 // is the identity conversion, unless the argument expression 2295 // has a type that is a derived class of the parameter type, 2296 // in which case the implicit conversion sequence is a 2297 // derived-to-base Conversion (13.3.3.1). 2298 ICS.setStandard(); 2299 ICS.Standard.First = ICK_Identity; 2300 ICS.Standard.Second = DerivedToBase? ICK_Derived_To_Base : ICK_Identity; 2301 ICS.Standard.Third = ICK_Identity; 2302 ICS.Standard.FromTypePtr = T2.getAsOpaquePtr(); 2303 ICS.Standard.setToType(0, T2); 2304 ICS.Standard.setToType(1, T1); 2305 ICS.Standard.setToType(2, T1); 2306 ICS.Standard.ReferenceBinding = true; 2307 ICS.Standard.DirectBinding = true; 2308 ICS.Standard.RRefBinding = false; 2309 ICS.Standard.CopyConstructor = 0; 2310 2311 // Nothing more to do: the inaccessibility/ambiguity check for 2312 // derived-to-base conversions is suppressed when we're 2313 // computing the implicit conversion sequence (C++ 2314 // [over.best.ics]p2). 2315 return ICS; 2316 } 2317 2318 // -- has a class type (i.e., T2 is a class type), where T1 is 2319 // not reference-related to T2, and can be implicitly 2320 // converted to an lvalue of type "cv3 T3," where "cv1 T1" 2321 // is reference-compatible with "cv3 T3" 92) (this 2322 // conversion is selected by enumerating the applicable 2323 // conversion functions (13.3.1.6) and choosing the best 2324 // one through overload resolution (13.3)), 2325 if (!isRValRef && !SuppressUserConversions && T2->isRecordType() && 2326 !S.RequireCompleteType(DeclLoc, T2, 0) && 2327 RefRelationship == Sema::Ref_Incompatible) { 2328 CXXRecordDecl *T2RecordDecl 2329 = dyn_cast<CXXRecordDecl>(T2->getAs<RecordType>()->getDecl()); 2330 2331 OverloadCandidateSet CandidateSet(DeclLoc); 2332 const UnresolvedSetImpl *Conversions 2333 = T2RecordDecl->getVisibleConversionFunctions(); 2334 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 2335 E = Conversions->end(); I != E; ++I) { 2336 NamedDecl *D = *I; 2337 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(D->getDeclContext()); 2338 if (isa<UsingShadowDecl>(D)) 2339 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 2340 2341 FunctionTemplateDecl *ConvTemplate 2342 = dyn_cast<FunctionTemplateDecl>(D); 2343 CXXConversionDecl *Conv; 2344 if (ConvTemplate) 2345 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 2346 else 2347 Conv = cast<CXXConversionDecl>(D); 2348 2349 // If the conversion function doesn't return a reference type, 2350 // it can't be considered for this conversion. 2351 if (Conv->getConversionType()->isLValueReferenceType() && 2352 (AllowExplicit || !Conv->isExplicit())) { 2353 if (ConvTemplate) 2354 S.AddTemplateConversionCandidate(ConvTemplate, I.getPair(), ActingDC, 2355 Init, DeclType, CandidateSet); 2356 else 2357 S.AddConversionCandidate(Conv, I.getPair(), ActingDC, Init, 2358 DeclType, CandidateSet); 2359 } 2360 } 2361 2362 OverloadCandidateSet::iterator Best; 2363 switch (S.BestViableFunction(CandidateSet, DeclLoc, Best)) { 2364 case OR_Success: 2365 // C++ [over.ics.ref]p1: 2366 // 2367 // [...] If the parameter binds directly to the result of 2368 // applying a conversion function to the argument 2369 // expression, the implicit conversion sequence is a 2370 // user-defined conversion sequence (13.3.3.1.2), with the 2371 // second standard conversion sequence either an identity 2372 // conversion or, if the conversion function returns an 2373 // entity of a type that is a derived class of the parameter 2374 // type, a derived-to-base Conversion. 2375 if (!Best->FinalConversion.DirectBinding) 2376 break; 2377 2378 ICS.setUserDefined(); 2379 ICS.UserDefined.Before = Best->Conversions[0].Standard; 2380 ICS.UserDefined.After = Best->FinalConversion; 2381 ICS.UserDefined.ConversionFunction = Best->Function; 2382 ICS.UserDefined.EllipsisConversion = false; 2383 assert(ICS.UserDefined.After.ReferenceBinding && 2384 ICS.UserDefined.After.DirectBinding && 2385 "Expected a direct reference binding!"); 2386 return ICS; 2387 2388 case OR_Ambiguous: 2389 ICS.setAmbiguous(); 2390 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 2391 Cand != CandidateSet.end(); ++Cand) 2392 if (Cand->Viable) 2393 ICS.Ambiguous.addConversion(Cand->Function); 2394 return ICS; 2395 2396 case OR_No_Viable_Function: 2397 case OR_Deleted: 2398 // There was no suitable conversion, or we found a deleted 2399 // conversion; continue with other checks. 2400 break; 2401 } 2402 } 2403 2404 // -- Otherwise, the reference shall be to a non-volatile const 2405 // type (i.e., cv1 shall be const), or the reference shall be an 2406 // rvalue reference and the initializer expression shall be an rvalue. 2407 if (!isRValRef && T1.getCVRQualifiers() != Qualifiers::Const) 2408 return ICS; 2409 2410 // -- If the initializer expression is an rvalue, with T2 a 2411 // class type, and "cv1 T1" is reference-compatible with 2412 // "cv2 T2," the reference is bound in one of the 2413 // following ways (the choice is implementation-defined): 2414 // 2415 // -- The reference is bound to the object represented by 2416 // the rvalue (see 3.10) or to a sub-object within that 2417 // object. 2418 // 2419 // -- A temporary of type "cv1 T2" [sic] is created, and 2420 // a constructor is called to copy the entire rvalue 2421 // object into the temporary. The reference is bound to 2422 // the temporary or to a sub-object within the 2423 // temporary. 2424 // 2425 // The constructor that would be used to make the copy 2426 // shall be callable whether or not the copy is actually 2427 // done. 2428 // 2429 // Note that C++0x [dcl.init.ref]p5 takes away this implementation 2430 // freedom, so we will always take the first option and never build 2431 // a temporary in this case. 2432 if (InitLvalue != Expr::LV_Valid && T2->isRecordType() && 2433 RefRelationship >= Sema::Ref_Compatible_With_Added_Qualification) { 2434 ICS.setStandard(); 2435 ICS.Standard.First = ICK_Identity; 2436 ICS.Standard.Second = DerivedToBase? ICK_Derived_To_Base : ICK_Identity; 2437 ICS.Standard.Third = ICK_Identity; 2438 ICS.Standard.FromTypePtr = T2.getAsOpaquePtr(); 2439 ICS.Standard.setToType(0, T2); 2440 ICS.Standard.setToType(1, T1); 2441 ICS.Standard.setToType(2, T1); 2442 ICS.Standard.ReferenceBinding = true; 2443 ICS.Standard.DirectBinding = false; 2444 ICS.Standard.RRefBinding = isRValRef; 2445 ICS.Standard.CopyConstructor = 0; 2446 return ICS; 2447 } 2448 2449 // -- Otherwise, a temporary of type "cv1 T1" is created and 2450 // initialized from the initializer expression using the 2451 // rules for a non-reference copy initialization (8.5). The 2452 // reference is then bound to the temporary. If T1 is 2453 // reference-related to T2, cv1 must be the same 2454 // cv-qualification as, or greater cv-qualification than, 2455 // cv2; otherwise, the program is ill-formed. 2456 if (RefRelationship == Sema::Ref_Related) { 2457 // If cv1 == cv2 or cv1 is a greater cv-qualified than cv2, then 2458 // we would be reference-compatible or reference-compatible with 2459 // added qualification. But that wasn't the case, so the reference 2460 // initialization fails. 2461 return ICS; 2462 } 2463 2464 // If at least one of the types is a class type, the types are not 2465 // related, and we aren't allowed any user conversions, the 2466 // reference binding fails. This case is important for breaking 2467 // recursion, since TryImplicitConversion below will attempt to 2468 // create a temporary through the use of a copy constructor. 2469 if (SuppressUserConversions && RefRelationship == Sema::Ref_Incompatible && 2470 (T1->isRecordType() || T2->isRecordType())) 2471 return ICS; 2472 2473 // C++ [over.ics.ref]p2: 2474 // 2475 // When a parameter of reference type is not bound directly to 2476 // an argument expression, the conversion sequence is the one 2477 // required to convert the argument expression to the 2478 // underlying type of the reference according to 2479 // 13.3.3.1. Conceptually, this conversion sequence corresponds 2480 // to copy-initializing a temporary of the underlying type with 2481 // the argument expression. Any difference in top-level 2482 // cv-qualification is subsumed by the initialization itself 2483 // and does not constitute a conversion. 2484 ICS = S.TryImplicitConversion(Init, T1, SuppressUserConversions, 2485 /*AllowExplicit=*/false, 2486 /*ForceRValue=*/false, 2487 /*InOverloadResolution=*/false); 2488 2489 // Of course, that's still a reference binding. 2490 if (ICS.isStandard()) { 2491 ICS.Standard.ReferenceBinding = true; 2492 ICS.Standard.RRefBinding = isRValRef; 2493 } else if (ICS.isUserDefined()) { 2494 ICS.UserDefined.After.ReferenceBinding = true; 2495 ICS.UserDefined.After.RRefBinding = isRValRef; 2496 } 2497 return ICS; 2498} 2499 2500/// TryCopyInitialization - Try to copy-initialize a value of type 2501/// ToType from the expression From. Return the implicit conversion 2502/// sequence required to pass this argument, which may be a bad 2503/// conversion sequence (meaning that the argument cannot be passed to 2504/// a parameter of this type). If @p SuppressUserConversions, then we 2505/// do not permit any user-defined conversion sequences. If @p ForceRValue, 2506/// then we treat @p From as an rvalue, even if it is an lvalue. 2507static ImplicitConversionSequence 2508TryCopyInitialization(Sema &S, Expr *From, QualType ToType, 2509 bool SuppressUserConversions, bool ForceRValue, 2510 bool InOverloadResolution) { 2511 if (ToType->isReferenceType()) 2512 return TryReferenceInit(S, From, ToType, 2513 /*FIXME:*/From->getLocStart(), 2514 SuppressUserConversions, 2515 /*AllowExplicit=*/false); 2516 2517 return S.TryImplicitConversion(From, ToType, 2518 SuppressUserConversions, 2519 /*AllowExplicit=*/false, 2520 ForceRValue, 2521 InOverloadResolution); 2522} 2523 2524/// TryObjectArgumentInitialization - Try to initialize the object 2525/// parameter of the given member function (@c Method) from the 2526/// expression @p From. 2527ImplicitConversionSequence 2528Sema::TryObjectArgumentInitialization(QualType OrigFromType, 2529 CXXMethodDecl *Method, 2530 CXXRecordDecl *ActingContext) { 2531 QualType ClassType = Context.getTypeDeclType(ActingContext); 2532 // [class.dtor]p2: A destructor can be invoked for a const, volatile or 2533 // const volatile object. 2534 unsigned Quals = isa<CXXDestructorDecl>(Method) ? 2535 Qualifiers::Const | Qualifiers::Volatile : Method->getTypeQualifiers(); 2536 QualType ImplicitParamType = Context.getCVRQualifiedType(ClassType, Quals); 2537 2538 // Set up the conversion sequence as a "bad" conversion, to allow us 2539 // to exit early. 2540 ImplicitConversionSequence ICS; 2541 2542 // We need to have an object of class type. 2543 QualType FromType = OrigFromType; 2544 if (const PointerType *PT = FromType->getAs<PointerType>()) 2545 FromType = PT->getPointeeType(); 2546 2547 assert(FromType->isRecordType()); 2548 2549 // The implicit object parameter is has the type "reference to cv X", 2550 // where X is the class of which the function is a member 2551 // (C++ [over.match.funcs]p4). However, when finding an implicit 2552 // conversion sequence for the argument, we are not allowed to 2553 // create temporaries or perform user-defined conversions 2554 // (C++ [over.match.funcs]p5). We perform a simplified version of 2555 // reference binding here, that allows class rvalues to bind to 2556 // non-constant references. 2557 2558 // First check the qualifiers. We don't care about lvalue-vs-rvalue 2559 // with the implicit object parameter (C++ [over.match.funcs]p5). 2560 QualType FromTypeCanon = Context.getCanonicalType(FromType); 2561 if (ImplicitParamType.getCVRQualifiers() 2562 != FromTypeCanon.getLocalCVRQualifiers() && 2563 !ImplicitParamType.isAtLeastAsQualifiedAs(FromTypeCanon)) { 2564 ICS.setBad(BadConversionSequence::bad_qualifiers, 2565 OrigFromType, ImplicitParamType); 2566 return ICS; 2567 } 2568 2569 // Check that we have either the same type or a derived type. It 2570 // affects the conversion rank. 2571 QualType ClassTypeCanon = Context.getCanonicalType(ClassType); 2572 ImplicitConversionKind SecondKind; 2573 if (ClassTypeCanon == FromTypeCanon.getLocalUnqualifiedType()) { 2574 SecondKind = ICK_Identity; 2575 } else if (IsDerivedFrom(FromType, ClassType)) 2576 SecondKind = ICK_Derived_To_Base; 2577 else { 2578 ICS.setBad(BadConversionSequence::unrelated_class, 2579 FromType, ImplicitParamType); 2580 return ICS; 2581 } 2582 2583 // Success. Mark this as a reference binding. 2584 ICS.setStandard(); 2585 ICS.Standard.setAsIdentityConversion(); 2586 ICS.Standard.Second = SecondKind; 2587 ICS.Standard.setFromType(FromType); 2588 ICS.Standard.setAllToTypes(ImplicitParamType); 2589 ICS.Standard.ReferenceBinding = true; 2590 ICS.Standard.DirectBinding = true; 2591 ICS.Standard.RRefBinding = false; 2592 return ICS; 2593} 2594 2595/// PerformObjectArgumentInitialization - Perform initialization of 2596/// the implicit object parameter for the given Method with the given 2597/// expression. 2598bool 2599Sema::PerformObjectArgumentInitialization(Expr *&From, 2600 NestedNameSpecifier *Qualifier, 2601 NamedDecl *FoundDecl, 2602 CXXMethodDecl *Method) { 2603 QualType FromRecordType, DestType; 2604 QualType ImplicitParamRecordType = 2605 Method->getThisType(Context)->getAs<PointerType>()->getPointeeType(); 2606 2607 if (const PointerType *PT = From->getType()->getAs<PointerType>()) { 2608 FromRecordType = PT->getPointeeType(); 2609 DestType = Method->getThisType(Context); 2610 } else { 2611 FromRecordType = From->getType(); 2612 DestType = ImplicitParamRecordType; 2613 } 2614 2615 // Note that we always use the true parent context when performing 2616 // the actual argument initialization. 2617 ImplicitConversionSequence ICS 2618 = TryObjectArgumentInitialization(From->getType(), Method, 2619 Method->getParent()); 2620 if (ICS.isBad()) 2621 return Diag(From->getSourceRange().getBegin(), 2622 diag::err_implicit_object_parameter_init) 2623 << ImplicitParamRecordType << FromRecordType << From->getSourceRange(); 2624 2625 if (ICS.Standard.Second == ICK_Derived_To_Base) 2626 return PerformObjectMemberConversion(From, Qualifier, FoundDecl, Method); 2627 2628 if (!Context.hasSameType(From->getType(), DestType)) 2629 ImpCastExprToType(From, DestType, CastExpr::CK_NoOp, 2630 /*isLvalue=*/!From->getType()->getAs<PointerType>()); 2631 return false; 2632} 2633 2634/// TryContextuallyConvertToBool - Attempt to contextually convert the 2635/// expression From to bool (C++0x [conv]p3). 2636ImplicitConversionSequence Sema::TryContextuallyConvertToBool(Expr *From) { 2637 return TryImplicitConversion(From, Context.BoolTy, 2638 // FIXME: Are these flags correct? 2639 /*SuppressUserConversions=*/false, 2640 /*AllowExplicit=*/true, 2641 /*ForceRValue=*/false, 2642 /*InOverloadResolution=*/false); 2643} 2644 2645/// PerformContextuallyConvertToBool - Perform a contextual conversion 2646/// of the expression From to bool (C++0x [conv]p3). 2647bool Sema::PerformContextuallyConvertToBool(Expr *&From) { 2648 ImplicitConversionSequence ICS = TryContextuallyConvertToBool(From); 2649 if (!ICS.isBad()) 2650 return PerformImplicitConversion(From, Context.BoolTy, ICS, AA_Converting); 2651 2652 if (!DiagnoseMultipleUserDefinedConversion(From, Context.BoolTy)) 2653 return Diag(From->getSourceRange().getBegin(), 2654 diag::err_typecheck_bool_condition) 2655 << From->getType() << From->getSourceRange(); 2656 return true; 2657} 2658 2659/// AddOverloadCandidate - Adds the given function to the set of 2660/// candidate functions, using the given function call arguments. If 2661/// @p SuppressUserConversions, then don't allow user-defined 2662/// conversions via constructors or conversion operators. 2663/// 2664/// \para PartialOverloading true if we are performing "partial" overloading 2665/// based on an incomplete set of function arguments. This feature is used by 2666/// code completion. 2667void 2668Sema::AddOverloadCandidate(FunctionDecl *Function, 2669 DeclAccessPair FoundDecl, 2670 Expr **Args, unsigned NumArgs, 2671 OverloadCandidateSet& CandidateSet, 2672 bool SuppressUserConversions, 2673 bool PartialOverloading) { 2674 const FunctionProtoType* Proto 2675 = dyn_cast<FunctionProtoType>(Function->getType()->getAs<FunctionType>()); 2676 assert(Proto && "Functions without a prototype cannot be overloaded"); 2677 assert(!Function->getDescribedFunctionTemplate() && 2678 "Use AddTemplateOverloadCandidate for function templates"); 2679 2680 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Function)) { 2681 if (!isa<CXXConstructorDecl>(Method)) { 2682 // If we get here, it's because we're calling a member function 2683 // that is named without a member access expression (e.g., 2684 // "this->f") that was either written explicitly or created 2685 // implicitly. This can happen with a qualified call to a member 2686 // function, e.g., X::f(). We use an empty type for the implied 2687 // object argument (C++ [over.call.func]p3), and the acting context 2688 // is irrelevant. 2689 AddMethodCandidate(Method, FoundDecl, Method->getParent(), 2690 QualType(), Args, NumArgs, CandidateSet, 2691 SuppressUserConversions); 2692 return; 2693 } 2694 // We treat a constructor like a non-member function, since its object 2695 // argument doesn't participate in overload resolution. 2696 } 2697 2698 if (!CandidateSet.isNewCandidate(Function)) 2699 return; 2700 2701 // Overload resolution is always an unevaluated context. 2702 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 2703 2704 if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(Function)){ 2705 // C++ [class.copy]p3: 2706 // A member function template is never instantiated to perform the copy 2707 // of a class object to an object of its class type. 2708 QualType ClassType = Context.getTypeDeclType(Constructor->getParent()); 2709 if (NumArgs == 1 && 2710 Constructor->isCopyConstructorLikeSpecialization() && 2711 (Context.hasSameUnqualifiedType(ClassType, Args[0]->getType()) || 2712 IsDerivedFrom(Args[0]->getType(), ClassType))) 2713 return; 2714 } 2715 2716 // Add this candidate 2717 CandidateSet.push_back(OverloadCandidate()); 2718 OverloadCandidate& Candidate = CandidateSet.back(); 2719 Candidate.FoundDecl = FoundDecl; 2720 Candidate.Function = Function; 2721 Candidate.Viable = true; 2722 Candidate.IsSurrogate = false; 2723 Candidate.IgnoreObjectArgument = false; 2724 2725 unsigned NumArgsInProto = Proto->getNumArgs(); 2726 2727 // (C++ 13.3.2p2): A candidate function having fewer than m 2728 // parameters is viable only if it has an ellipsis in its parameter 2729 // list (8.3.5). 2730 if ((NumArgs + (PartialOverloading && NumArgs)) > NumArgsInProto && 2731 !Proto->isVariadic()) { 2732 Candidate.Viable = false; 2733 Candidate.FailureKind = ovl_fail_too_many_arguments; 2734 return; 2735 } 2736 2737 // (C++ 13.3.2p2): A candidate function having more than m parameters 2738 // is viable only if the (m+1)st parameter has a default argument 2739 // (8.3.6). For the purposes of overload resolution, the 2740 // parameter list is truncated on the right, so that there are 2741 // exactly m parameters. 2742 unsigned MinRequiredArgs = Function->getMinRequiredArguments(); 2743 if (NumArgs < MinRequiredArgs && !PartialOverloading) { 2744 // Not enough arguments. 2745 Candidate.Viable = false; 2746 Candidate.FailureKind = ovl_fail_too_few_arguments; 2747 return; 2748 } 2749 2750 // Determine the implicit conversion sequences for each of the 2751 // arguments. 2752 Candidate.Conversions.resize(NumArgs); 2753 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2754 if (ArgIdx < NumArgsInProto) { 2755 // (C++ 13.3.2p3): for F to be a viable function, there shall 2756 // exist for each argument an implicit conversion sequence 2757 // (13.3.3.1) that converts that argument to the corresponding 2758 // parameter of F. 2759 QualType ParamType = Proto->getArgType(ArgIdx); 2760 Candidate.Conversions[ArgIdx] 2761 = TryCopyInitialization(*this, Args[ArgIdx], ParamType, 2762 SuppressUserConversions, 2763 /*ForceRValue=*/false, 2764 /*InOverloadResolution=*/true); 2765 if (Candidate.Conversions[ArgIdx].isBad()) { 2766 Candidate.Viable = false; 2767 Candidate.FailureKind = ovl_fail_bad_conversion; 2768 break; 2769 } 2770 } else { 2771 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2772 // argument for which there is no corresponding parameter is 2773 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2774 Candidate.Conversions[ArgIdx].setEllipsis(); 2775 } 2776 } 2777} 2778 2779/// \brief Add all of the function declarations in the given function set to 2780/// the overload canddiate set. 2781void Sema::AddFunctionCandidates(const UnresolvedSetImpl &Fns, 2782 Expr **Args, unsigned NumArgs, 2783 OverloadCandidateSet& CandidateSet, 2784 bool SuppressUserConversions) { 2785 for (UnresolvedSetIterator F = Fns.begin(), E = Fns.end(); F != E; ++F) { 2786 NamedDecl *D = F.getDecl()->getUnderlyingDecl(); 2787 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { 2788 if (isa<CXXMethodDecl>(FD) && !cast<CXXMethodDecl>(FD)->isStatic()) 2789 AddMethodCandidate(cast<CXXMethodDecl>(FD), F.getPair(), 2790 cast<CXXMethodDecl>(FD)->getParent(), 2791 Args[0]->getType(), Args + 1, NumArgs - 1, 2792 CandidateSet, SuppressUserConversions); 2793 else 2794 AddOverloadCandidate(FD, F.getPair(), Args, NumArgs, CandidateSet, 2795 SuppressUserConversions); 2796 } else { 2797 FunctionTemplateDecl *FunTmpl = cast<FunctionTemplateDecl>(D); 2798 if (isa<CXXMethodDecl>(FunTmpl->getTemplatedDecl()) && 2799 !cast<CXXMethodDecl>(FunTmpl->getTemplatedDecl())->isStatic()) 2800 AddMethodTemplateCandidate(FunTmpl, F.getPair(), 2801 cast<CXXRecordDecl>(FunTmpl->getDeclContext()), 2802 /*FIXME: explicit args */ 0, 2803 Args[0]->getType(), Args + 1, NumArgs - 1, 2804 CandidateSet, 2805 SuppressUserConversions); 2806 else 2807 AddTemplateOverloadCandidate(FunTmpl, F.getPair(), 2808 /*FIXME: explicit args */ 0, 2809 Args, NumArgs, CandidateSet, 2810 SuppressUserConversions); 2811 } 2812 } 2813} 2814 2815/// AddMethodCandidate - Adds a named decl (which is some kind of 2816/// method) as a method candidate to the given overload set. 2817void Sema::AddMethodCandidate(DeclAccessPair FoundDecl, 2818 QualType ObjectType, 2819 Expr **Args, unsigned NumArgs, 2820 OverloadCandidateSet& CandidateSet, 2821 bool SuppressUserConversions) { 2822 NamedDecl *Decl = FoundDecl.getDecl(); 2823 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(Decl->getDeclContext()); 2824 2825 if (isa<UsingShadowDecl>(Decl)) 2826 Decl = cast<UsingShadowDecl>(Decl)->getTargetDecl(); 2827 2828 if (FunctionTemplateDecl *TD = dyn_cast<FunctionTemplateDecl>(Decl)) { 2829 assert(isa<CXXMethodDecl>(TD->getTemplatedDecl()) && 2830 "Expected a member function template"); 2831 AddMethodTemplateCandidate(TD, FoundDecl, ActingContext, 2832 /*ExplicitArgs*/ 0, 2833 ObjectType, Args, NumArgs, 2834 CandidateSet, 2835 SuppressUserConversions); 2836 } else { 2837 AddMethodCandidate(cast<CXXMethodDecl>(Decl), FoundDecl, ActingContext, 2838 ObjectType, Args, NumArgs, 2839 CandidateSet, SuppressUserConversions); 2840 } 2841} 2842 2843/// AddMethodCandidate - Adds the given C++ member function to the set 2844/// of candidate functions, using the given function call arguments 2845/// and the object argument (@c Object). For example, in a call 2846/// @c o.f(a1,a2), @c Object will contain @c o and @c Args will contain 2847/// both @c a1 and @c a2. If @p SuppressUserConversions, then don't 2848/// allow user-defined conversions via constructors or conversion 2849/// operators. 2850void 2851Sema::AddMethodCandidate(CXXMethodDecl *Method, DeclAccessPair FoundDecl, 2852 CXXRecordDecl *ActingContext, QualType ObjectType, 2853 Expr **Args, unsigned NumArgs, 2854 OverloadCandidateSet& CandidateSet, 2855 bool SuppressUserConversions) { 2856 const FunctionProtoType* Proto 2857 = dyn_cast<FunctionProtoType>(Method->getType()->getAs<FunctionType>()); 2858 assert(Proto && "Methods without a prototype cannot be overloaded"); 2859 assert(!isa<CXXConstructorDecl>(Method) && 2860 "Use AddOverloadCandidate for constructors"); 2861 2862 if (!CandidateSet.isNewCandidate(Method)) 2863 return; 2864 2865 // Overload resolution is always an unevaluated context. 2866 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 2867 2868 // Add this candidate 2869 CandidateSet.push_back(OverloadCandidate()); 2870 OverloadCandidate& Candidate = CandidateSet.back(); 2871 Candidate.FoundDecl = FoundDecl; 2872 Candidate.Function = Method; 2873 Candidate.IsSurrogate = false; 2874 Candidate.IgnoreObjectArgument = false; 2875 2876 unsigned NumArgsInProto = Proto->getNumArgs(); 2877 2878 // (C++ 13.3.2p2): A candidate function having fewer than m 2879 // parameters is viable only if it has an ellipsis in its parameter 2880 // list (8.3.5). 2881 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 2882 Candidate.Viable = false; 2883 Candidate.FailureKind = ovl_fail_too_many_arguments; 2884 return; 2885 } 2886 2887 // (C++ 13.3.2p2): A candidate function having more than m parameters 2888 // is viable only if the (m+1)st parameter has a default argument 2889 // (8.3.6). For the purposes of overload resolution, the 2890 // parameter list is truncated on the right, so that there are 2891 // exactly m parameters. 2892 unsigned MinRequiredArgs = Method->getMinRequiredArguments(); 2893 if (NumArgs < MinRequiredArgs) { 2894 // Not enough arguments. 2895 Candidate.Viable = false; 2896 Candidate.FailureKind = ovl_fail_too_few_arguments; 2897 return; 2898 } 2899 2900 Candidate.Viable = true; 2901 Candidate.Conversions.resize(NumArgs + 1); 2902 2903 if (Method->isStatic() || ObjectType.isNull()) 2904 // The implicit object argument is ignored. 2905 Candidate.IgnoreObjectArgument = true; 2906 else { 2907 // Determine the implicit conversion sequence for the object 2908 // parameter. 2909 Candidate.Conversions[0] 2910 = TryObjectArgumentInitialization(ObjectType, Method, ActingContext); 2911 if (Candidate.Conversions[0].isBad()) { 2912 Candidate.Viable = false; 2913 Candidate.FailureKind = ovl_fail_bad_conversion; 2914 return; 2915 } 2916 } 2917 2918 // Determine the implicit conversion sequences for each of the 2919 // arguments. 2920 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2921 if (ArgIdx < NumArgsInProto) { 2922 // (C++ 13.3.2p3): for F to be a viable function, there shall 2923 // exist for each argument an implicit conversion sequence 2924 // (13.3.3.1) that converts that argument to the corresponding 2925 // parameter of F. 2926 QualType ParamType = Proto->getArgType(ArgIdx); 2927 Candidate.Conversions[ArgIdx + 1] 2928 = TryCopyInitialization(*this, Args[ArgIdx], ParamType, 2929 SuppressUserConversions, 2930 /*ForceRValue=*/false, 2931 /*InOverloadResolution=*/true); 2932 if (Candidate.Conversions[ArgIdx + 1].isBad()) { 2933 Candidate.Viable = false; 2934 Candidate.FailureKind = ovl_fail_bad_conversion; 2935 break; 2936 } 2937 } else { 2938 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2939 // argument for which there is no corresponding parameter is 2940 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2941 Candidate.Conversions[ArgIdx + 1].setEllipsis(); 2942 } 2943 } 2944} 2945 2946/// \brief Add a C++ member function template as a candidate to the candidate 2947/// set, using template argument deduction to produce an appropriate member 2948/// function template specialization. 2949void 2950Sema::AddMethodTemplateCandidate(FunctionTemplateDecl *MethodTmpl, 2951 DeclAccessPair FoundDecl, 2952 CXXRecordDecl *ActingContext, 2953 const TemplateArgumentListInfo *ExplicitTemplateArgs, 2954 QualType ObjectType, 2955 Expr **Args, unsigned NumArgs, 2956 OverloadCandidateSet& CandidateSet, 2957 bool SuppressUserConversions) { 2958 if (!CandidateSet.isNewCandidate(MethodTmpl)) 2959 return; 2960 2961 // C++ [over.match.funcs]p7: 2962 // In each case where a candidate is a function template, candidate 2963 // function template specializations are generated using template argument 2964 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 2965 // candidate functions in the usual way.113) A given name can refer to one 2966 // or more function templates and also to a set of overloaded non-template 2967 // functions. In such a case, the candidate functions generated from each 2968 // function template are combined with the set of non-template candidate 2969 // functions. 2970 TemplateDeductionInfo Info(Context, CandidateSet.getLocation()); 2971 FunctionDecl *Specialization = 0; 2972 if (TemplateDeductionResult Result 2973 = DeduceTemplateArguments(MethodTmpl, ExplicitTemplateArgs, 2974 Args, NumArgs, Specialization, Info)) { 2975 // FIXME: Record what happened with template argument deduction, so 2976 // that we can give the user a beautiful diagnostic. 2977 (void)Result; 2978 return; 2979 } 2980 2981 // Add the function template specialization produced by template argument 2982 // deduction as a candidate. 2983 assert(Specialization && "Missing member function template specialization?"); 2984 assert(isa<CXXMethodDecl>(Specialization) && 2985 "Specialization is not a member function?"); 2986 AddMethodCandidate(cast<CXXMethodDecl>(Specialization), FoundDecl, 2987 ActingContext, ObjectType, Args, NumArgs, 2988 CandidateSet, SuppressUserConversions); 2989} 2990 2991/// \brief Add a C++ function template specialization as a candidate 2992/// in the candidate set, using template argument deduction to produce 2993/// an appropriate function template specialization. 2994void 2995Sema::AddTemplateOverloadCandidate(FunctionTemplateDecl *FunctionTemplate, 2996 DeclAccessPair FoundDecl, 2997 const TemplateArgumentListInfo *ExplicitTemplateArgs, 2998 Expr **Args, unsigned NumArgs, 2999 OverloadCandidateSet& CandidateSet, 3000 bool SuppressUserConversions) { 3001 if (!CandidateSet.isNewCandidate(FunctionTemplate)) 3002 return; 3003 3004 // C++ [over.match.funcs]p7: 3005 // In each case where a candidate is a function template, candidate 3006 // function template specializations are generated using template argument 3007 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 3008 // candidate functions in the usual way.113) A given name can refer to one 3009 // or more function templates and also to a set of overloaded non-template 3010 // functions. In such a case, the candidate functions generated from each 3011 // function template are combined with the set of non-template candidate 3012 // functions. 3013 TemplateDeductionInfo Info(Context, CandidateSet.getLocation()); 3014 FunctionDecl *Specialization = 0; 3015 if (TemplateDeductionResult Result 3016 = DeduceTemplateArguments(FunctionTemplate, ExplicitTemplateArgs, 3017 Args, NumArgs, Specialization, Info)) { 3018 CandidateSet.push_back(OverloadCandidate()); 3019 OverloadCandidate &Candidate = CandidateSet.back(); 3020 Candidate.FoundDecl = FoundDecl; 3021 Candidate.Function = FunctionTemplate->getTemplatedDecl(); 3022 Candidate.Viable = false; 3023 Candidate.FailureKind = ovl_fail_bad_deduction; 3024 Candidate.IsSurrogate = false; 3025 Candidate.IgnoreObjectArgument = false; 3026 3027 // TODO: record more information about failed template arguments 3028 Candidate.DeductionFailure.Result = Result; 3029 Candidate.DeductionFailure.TemplateParameter = Info.Param.getOpaqueValue(); 3030 return; 3031 } 3032 3033 // Add the function template specialization produced by template argument 3034 // deduction as a candidate. 3035 assert(Specialization && "Missing function template specialization?"); 3036 AddOverloadCandidate(Specialization, FoundDecl, Args, NumArgs, CandidateSet, 3037 SuppressUserConversions); 3038} 3039 3040/// AddConversionCandidate - Add a C++ conversion function as a 3041/// candidate in the candidate set (C++ [over.match.conv], 3042/// C++ [over.match.copy]). From is the expression we're converting from, 3043/// and ToType is the type that we're eventually trying to convert to 3044/// (which may or may not be the same type as the type that the 3045/// conversion function produces). 3046void 3047Sema::AddConversionCandidate(CXXConversionDecl *Conversion, 3048 DeclAccessPair FoundDecl, 3049 CXXRecordDecl *ActingContext, 3050 Expr *From, QualType ToType, 3051 OverloadCandidateSet& CandidateSet) { 3052 assert(!Conversion->getDescribedFunctionTemplate() && 3053 "Conversion function templates use AddTemplateConversionCandidate"); 3054 3055 if (!CandidateSet.isNewCandidate(Conversion)) 3056 return; 3057 3058 // Overload resolution is always an unevaluated context. 3059 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 3060 3061 // Add this candidate 3062 CandidateSet.push_back(OverloadCandidate()); 3063 OverloadCandidate& Candidate = CandidateSet.back(); 3064 Candidate.FoundDecl = FoundDecl; 3065 Candidate.Function = Conversion; 3066 Candidate.IsSurrogate = false; 3067 Candidate.IgnoreObjectArgument = false; 3068 Candidate.FinalConversion.setAsIdentityConversion(); 3069 Candidate.FinalConversion.setFromType(Conversion->getConversionType()); 3070 Candidate.FinalConversion.setAllToTypes(ToType); 3071 3072 // Determine the implicit conversion sequence for the implicit 3073 // object parameter. 3074 Candidate.Viable = true; 3075 Candidate.Conversions.resize(1); 3076 Candidate.Conversions[0] 3077 = TryObjectArgumentInitialization(From->getType(), Conversion, 3078 ActingContext); 3079 // Conversion functions to a different type in the base class is visible in 3080 // the derived class. So, a derived to base conversion should not participate 3081 // in overload resolution. 3082 if (Candidate.Conversions[0].Standard.Second == ICK_Derived_To_Base) 3083 Candidate.Conversions[0].Standard.Second = ICK_Identity; 3084 if (Candidate.Conversions[0].isBad()) { 3085 Candidate.Viable = false; 3086 Candidate.FailureKind = ovl_fail_bad_conversion; 3087 return; 3088 } 3089 3090 // We won't go through a user-define type conversion function to convert a 3091 // derived to base as such conversions are given Conversion Rank. They only 3092 // go through a copy constructor. 13.3.3.1.2-p4 [over.ics.user] 3093 QualType FromCanon 3094 = Context.getCanonicalType(From->getType().getUnqualifiedType()); 3095 QualType ToCanon = Context.getCanonicalType(ToType).getUnqualifiedType(); 3096 if (FromCanon == ToCanon || IsDerivedFrom(FromCanon, ToCanon)) { 3097 Candidate.Viable = false; 3098 Candidate.FailureKind = ovl_fail_trivial_conversion; 3099 return; 3100 } 3101 3102 3103 // To determine what the conversion from the result of calling the 3104 // conversion function to the type we're eventually trying to 3105 // convert to (ToType), we need to synthesize a call to the 3106 // conversion function and attempt copy initialization from it. This 3107 // makes sure that we get the right semantics with respect to 3108 // lvalues/rvalues and the type. Fortunately, we can allocate this 3109 // call on the stack and we don't need its arguments to be 3110 // well-formed. 3111 DeclRefExpr ConversionRef(Conversion, Conversion->getType(), 3112 From->getLocStart()); 3113 ImplicitCastExpr ConversionFn(Context.getPointerType(Conversion->getType()), 3114 CastExpr::CK_FunctionToPointerDecay, 3115 &ConversionRef, false); 3116 3117 // Note that it is safe to allocate CallExpr on the stack here because 3118 // there are 0 arguments (i.e., nothing is allocated using ASTContext's 3119 // allocator). 3120 CallExpr Call(Context, &ConversionFn, 0, 0, 3121 Conversion->getConversionType().getNonReferenceType(), 3122 From->getLocStart()); 3123 ImplicitConversionSequence ICS = 3124 TryCopyInitialization(*this, &Call, ToType, 3125 /*SuppressUserConversions=*/true, 3126 /*ForceRValue=*/false, 3127 /*InOverloadResolution=*/false); 3128 3129 switch (ICS.getKind()) { 3130 case ImplicitConversionSequence::StandardConversion: 3131 Candidate.FinalConversion = ICS.Standard; 3132 3133 // C++ [over.ics.user]p3: 3134 // If the user-defined conversion is specified by a specialization of a 3135 // conversion function template, the second standard conversion sequence 3136 // shall have exact match rank. 3137 if (Conversion->getPrimaryTemplate() && 3138 GetConversionRank(ICS.Standard.Second) != ICR_Exact_Match) { 3139 Candidate.Viable = false; 3140 Candidate.FailureKind = ovl_fail_final_conversion_not_exact; 3141 } 3142 3143 break; 3144 3145 case ImplicitConversionSequence::BadConversion: 3146 Candidate.Viable = false; 3147 Candidate.FailureKind = ovl_fail_bad_final_conversion; 3148 break; 3149 3150 default: 3151 assert(false && 3152 "Can only end up with a standard conversion sequence or failure"); 3153 } 3154} 3155 3156/// \brief Adds a conversion function template specialization 3157/// candidate to the overload set, using template argument deduction 3158/// to deduce the template arguments of the conversion function 3159/// template from the type that we are converting to (C++ 3160/// [temp.deduct.conv]). 3161void 3162Sema::AddTemplateConversionCandidate(FunctionTemplateDecl *FunctionTemplate, 3163 DeclAccessPair FoundDecl, 3164 CXXRecordDecl *ActingDC, 3165 Expr *From, QualType ToType, 3166 OverloadCandidateSet &CandidateSet) { 3167 assert(isa<CXXConversionDecl>(FunctionTemplate->getTemplatedDecl()) && 3168 "Only conversion function templates permitted here"); 3169 3170 if (!CandidateSet.isNewCandidate(FunctionTemplate)) 3171 return; 3172 3173 TemplateDeductionInfo Info(Context, CandidateSet.getLocation()); 3174 CXXConversionDecl *Specialization = 0; 3175 if (TemplateDeductionResult Result 3176 = DeduceTemplateArguments(FunctionTemplate, ToType, 3177 Specialization, Info)) { 3178 // FIXME: Record what happened with template argument deduction, so 3179 // that we can give the user a beautiful diagnostic. 3180 (void)Result; 3181 return; 3182 } 3183 3184 // Add the conversion function template specialization produced by 3185 // template argument deduction as a candidate. 3186 assert(Specialization && "Missing function template specialization?"); 3187 AddConversionCandidate(Specialization, FoundDecl, ActingDC, From, ToType, 3188 CandidateSet); 3189} 3190 3191/// AddSurrogateCandidate - Adds a "surrogate" candidate function that 3192/// converts the given @c Object to a function pointer via the 3193/// conversion function @c Conversion, and then attempts to call it 3194/// with the given arguments (C++ [over.call.object]p2-4). Proto is 3195/// the type of function that we'll eventually be calling. 3196void Sema::AddSurrogateCandidate(CXXConversionDecl *Conversion, 3197 DeclAccessPair FoundDecl, 3198 CXXRecordDecl *ActingContext, 3199 const FunctionProtoType *Proto, 3200 QualType ObjectType, 3201 Expr **Args, unsigned NumArgs, 3202 OverloadCandidateSet& CandidateSet) { 3203 if (!CandidateSet.isNewCandidate(Conversion)) 3204 return; 3205 3206 // Overload resolution is always an unevaluated context. 3207 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 3208 3209 CandidateSet.push_back(OverloadCandidate()); 3210 OverloadCandidate& Candidate = CandidateSet.back(); 3211 Candidate.FoundDecl = FoundDecl; 3212 Candidate.Function = 0; 3213 Candidate.Surrogate = Conversion; 3214 Candidate.Viable = true; 3215 Candidate.IsSurrogate = true; 3216 Candidate.IgnoreObjectArgument = false; 3217 Candidate.Conversions.resize(NumArgs + 1); 3218 3219 // Determine the implicit conversion sequence for the implicit 3220 // object parameter. 3221 ImplicitConversionSequence ObjectInit 3222 = TryObjectArgumentInitialization(ObjectType, Conversion, ActingContext); 3223 if (ObjectInit.isBad()) { 3224 Candidate.Viable = false; 3225 Candidate.FailureKind = ovl_fail_bad_conversion; 3226 Candidate.Conversions[0] = ObjectInit; 3227 return; 3228 } 3229 3230 // The first conversion is actually a user-defined conversion whose 3231 // first conversion is ObjectInit's standard conversion (which is 3232 // effectively a reference binding). Record it as such. 3233 Candidate.Conversions[0].setUserDefined(); 3234 Candidate.Conversions[0].UserDefined.Before = ObjectInit.Standard; 3235 Candidate.Conversions[0].UserDefined.EllipsisConversion = false; 3236 Candidate.Conversions[0].UserDefined.ConversionFunction = Conversion; 3237 Candidate.Conversions[0].UserDefined.After 3238 = Candidate.Conversions[0].UserDefined.Before; 3239 Candidate.Conversions[0].UserDefined.After.setAsIdentityConversion(); 3240 3241 // Find the 3242 unsigned NumArgsInProto = Proto->getNumArgs(); 3243 3244 // (C++ 13.3.2p2): A candidate function having fewer than m 3245 // parameters is viable only if it has an ellipsis in its parameter 3246 // list (8.3.5). 3247 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 3248 Candidate.Viable = false; 3249 Candidate.FailureKind = ovl_fail_too_many_arguments; 3250 return; 3251 } 3252 3253 // Function types don't have any default arguments, so just check if 3254 // we have enough arguments. 3255 if (NumArgs < NumArgsInProto) { 3256 // Not enough arguments. 3257 Candidate.Viable = false; 3258 Candidate.FailureKind = ovl_fail_too_few_arguments; 3259 return; 3260 } 3261 3262 // Determine the implicit conversion sequences for each of the 3263 // arguments. 3264 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 3265 if (ArgIdx < NumArgsInProto) { 3266 // (C++ 13.3.2p3): for F to be a viable function, there shall 3267 // exist for each argument an implicit conversion sequence 3268 // (13.3.3.1) that converts that argument to the corresponding 3269 // parameter of F. 3270 QualType ParamType = Proto->getArgType(ArgIdx); 3271 Candidate.Conversions[ArgIdx + 1] 3272 = TryCopyInitialization(*this, Args[ArgIdx], ParamType, 3273 /*SuppressUserConversions=*/false, 3274 /*ForceRValue=*/false, 3275 /*InOverloadResolution=*/false); 3276 if (Candidate.Conversions[ArgIdx + 1].isBad()) { 3277 Candidate.Viable = false; 3278 Candidate.FailureKind = ovl_fail_bad_conversion; 3279 break; 3280 } 3281 } else { 3282 // (C++ 13.3.2p2): For the purposes of overload resolution, any 3283 // argument for which there is no corresponding parameter is 3284 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 3285 Candidate.Conversions[ArgIdx + 1].setEllipsis(); 3286 } 3287 } 3288} 3289 3290// FIXME: This will eventually be removed, once we've migrated all of the 3291// operator overloading logic over to the scheme used by binary operators, which 3292// works for template instantiation. 3293void Sema::AddOperatorCandidates(OverloadedOperatorKind Op, Scope *S, 3294 SourceLocation OpLoc, 3295 Expr **Args, unsigned NumArgs, 3296 OverloadCandidateSet& CandidateSet, 3297 SourceRange OpRange) { 3298 UnresolvedSet<16> Fns; 3299 3300 QualType T1 = Args[0]->getType(); 3301 QualType T2; 3302 if (NumArgs > 1) 3303 T2 = Args[1]->getType(); 3304 3305 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 3306 if (S) 3307 LookupOverloadedOperatorName(Op, S, T1, T2, Fns); 3308 AddFunctionCandidates(Fns, Args, NumArgs, CandidateSet, false); 3309 AddArgumentDependentLookupCandidates(OpName, false, Args, NumArgs, 0, 3310 CandidateSet); 3311 AddMemberOperatorCandidates(Op, OpLoc, Args, NumArgs, CandidateSet, OpRange); 3312 AddBuiltinOperatorCandidates(Op, OpLoc, Args, NumArgs, CandidateSet); 3313} 3314 3315/// \brief Add overload candidates for overloaded operators that are 3316/// member functions. 3317/// 3318/// Add the overloaded operator candidates that are member functions 3319/// for the operator Op that was used in an operator expression such 3320/// as "x Op y". , Args/NumArgs provides the operator arguments, and 3321/// CandidateSet will store the added overload candidates. (C++ 3322/// [over.match.oper]). 3323void Sema::AddMemberOperatorCandidates(OverloadedOperatorKind Op, 3324 SourceLocation OpLoc, 3325 Expr **Args, unsigned NumArgs, 3326 OverloadCandidateSet& CandidateSet, 3327 SourceRange OpRange) { 3328 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 3329 3330 // C++ [over.match.oper]p3: 3331 // For a unary operator @ with an operand of a type whose 3332 // cv-unqualified version is T1, and for a binary operator @ with 3333 // a left operand of a type whose cv-unqualified version is T1 and 3334 // a right operand of a type whose cv-unqualified version is T2, 3335 // three sets of candidate functions, designated member 3336 // candidates, non-member candidates and built-in candidates, are 3337 // constructed as follows: 3338 QualType T1 = Args[0]->getType(); 3339 QualType T2; 3340 if (NumArgs > 1) 3341 T2 = Args[1]->getType(); 3342 3343 // -- If T1 is a class type, the set of member candidates is the 3344 // result of the qualified lookup of T1::operator@ 3345 // (13.3.1.1.1); otherwise, the set of member candidates is 3346 // empty. 3347 if (const RecordType *T1Rec = T1->getAs<RecordType>()) { 3348 // Complete the type if it can be completed. Otherwise, we're done. 3349 if (RequireCompleteType(OpLoc, T1, PDiag())) 3350 return; 3351 3352 LookupResult Operators(*this, OpName, OpLoc, LookupOrdinaryName); 3353 LookupQualifiedName(Operators, T1Rec->getDecl()); 3354 Operators.suppressDiagnostics(); 3355 3356 for (LookupResult::iterator Oper = Operators.begin(), 3357 OperEnd = Operators.end(); 3358 Oper != OperEnd; 3359 ++Oper) 3360 AddMethodCandidate(Oper.getPair(), Args[0]->getType(), 3361 Args + 1, NumArgs - 1, CandidateSet, 3362 /* SuppressUserConversions = */ false); 3363 } 3364} 3365 3366/// AddBuiltinCandidate - Add a candidate for a built-in 3367/// operator. ResultTy and ParamTys are the result and parameter types 3368/// of the built-in candidate, respectively. Args and NumArgs are the 3369/// arguments being passed to the candidate. IsAssignmentOperator 3370/// should be true when this built-in candidate is an assignment 3371/// operator. NumContextualBoolArguments is the number of arguments 3372/// (at the beginning of the argument list) that will be contextually 3373/// converted to bool. 3374void Sema::AddBuiltinCandidate(QualType ResultTy, QualType *ParamTys, 3375 Expr **Args, unsigned NumArgs, 3376 OverloadCandidateSet& CandidateSet, 3377 bool IsAssignmentOperator, 3378 unsigned NumContextualBoolArguments) { 3379 // Overload resolution is always an unevaluated context. 3380 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 3381 3382 // Add this candidate 3383 CandidateSet.push_back(OverloadCandidate()); 3384 OverloadCandidate& Candidate = CandidateSet.back(); 3385 Candidate.FoundDecl = DeclAccessPair::make(0, AS_none); 3386 Candidate.Function = 0; 3387 Candidate.IsSurrogate = false; 3388 Candidate.IgnoreObjectArgument = false; 3389 Candidate.BuiltinTypes.ResultTy = ResultTy; 3390 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 3391 Candidate.BuiltinTypes.ParamTypes[ArgIdx] = ParamTys[ArgIdx]; 3392 3393 // Determine the implicit conversion sequences for each of the 3394 // arguments. 3395 Candidate.Viable = true; 3396 Candidate.Conversions.resize(NumArgs); 3397 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 3398 // C++ [over.match.oper]p4: 3399 // For the built-in assignment operators, conversions of the 3400 // left operand are restricted as follows: 3401 // -- no temporaries are introduced to hold the left operand, and 3402 // -- no user-defined conversions are applied to the left 3403 // operand to achieve a type match with the left-most 3404 // parameter of a built-in candidate. 3405 // 3406 // We block these conversions by turning off user-defined 3407 // conversions, since that is the only way that initialization of 3408 // a reference to a non-class type can occur from something that 3409 // is not of the same type. 3410 if (ArgIdx < NumContextualBoolArguments) { 3411 assert(ParamTys[ArgIdx] == Context.BoolTy && 3412 "Contextual conversion to bool requires bool type"); 3413 Candidate.Conversions[ArgIdx] = TryContextuallyConvertToBool(Args[ArgIdx]); 3414 } else { 3415 Candidate.Conversions[ArgIdx] 3416 = TryCopyInitialization(*this, Args[ArgIdx], ParamTys[ArgIdx], 3417 ArgIdx == 0 && IsAssignmentOperator, 3418 /*ForceRValue=*/false, 3419 /*InOverloadResolution=*/false); 3420 } 3421 if (Candidate.Conversions[ArgIdx].isBad()) { 3422 Candidate.Viable = false; 3423 Candidate.FailureKind = ovl_fail_bad_conversion; 3424 break; 3425 } 3426 } 3427} 3428 3429/// BuiltinCandidateTypeSet - A set of types that will be used for the 3430/// candidate operator functions for built-in operators (C++ 3431/// [over.built]). The types are separated into pointer types and 3432/// enumeration types. 3433class BuiltinCandidateTypeSet { 3434 /// TypeSet - A set of types. 3435 typedef llvm::SmallPtrSet<QualType, 8> TypeSet; 3436 3437 /// PointerTypes - The set of pointer types that will be used in the 3438 /// built-in candidates. 3439 TypeSet PointerTypes; 3440 3441 /// MemberPointerTypes - The set of member pointer types that will be 3442 /// used in the built-in candidates. 3443 TypeSet MemberPointerTypes; 3444 3445 /// EnumerationTypes - The set of enumeration types that will be 3446 /// used in the built-in candidates. 3447 TypeSet EnumerationTypes; 3448 3449 /// Sema - The semantic analysis instance where we are building the 3450 /// candidate type set. 3451 Sema &SemaRef; 3452 3453 /// Context - The AST context in which we will build the type sets. 3454 ASTContext &Context; 3455 3456 bool AddPointerWithMoreQualifiedTypeVariants(QualType Ty, 3457 const Qualifiers &VisibleQuals); 3458 bool AddMemberPointerWithMoreQualifiedTypeVariants(QualType Ty); 3459 3460public: 3461 /// iterator - Iterates through the types that are part of the set. 3462 typedef TypeSet::iterator iterator; 3463 3464 BuiltinCandidateTypeSet(Sema &SemaRef) 3465 : SemaRef(SemaRef), Context(SemaRef.Context) { } 3466 3467 void AddTypesConvertedFrom(QualType Ty, 3468 SourceLocation Loc, 3469 bool AllowUserConversions, 3470 bool AllowExplicitConversions, 3471 const Qualifiers &VisibleTypeConversionsQuals); 3472 3473 /// pointer_begin - First pointer type found; 3474 iterator pointer_begin() { return PointerTypes.begin(); } 3475 3476 /// pointer_end - Past the last pointer type found; 3477 iterator pointer_end() { return PointerTypes.end(); } 3478 3479 /// member_pointer_begin - First member pointer type found; 3480 iterator member_pointer_begin() { return MemberPointerTypes.begin(); } 3481 3482 /// member_pointer_end - Past the last member pointer type found; 3483 iterator member_pointer_end() { return MemberPointerTypes.end(); } 3484 3485 /// enumeration_begin - First enumeration type found; 3486 iterator enumeration_begin() { return EnumerationTypes.begin(); } 3487 3488 /// enumeration_end - Past the last enumeration type found; 3489 iterator enumeration_end() { return EnumerationTypes.end(); } 3490}; 3491 3492/// AddPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty to 3493/// the set of pointer types along with any more-qualified variants of 3494/// that type. For example, if @p Ty is "int const *", this routine 3495/// will add "int const *", "int const volatile *", "int const 3496/// restrict *", and "int const volatile restrict *" to the set of 3497/// pointer types. Returns true if the add of @p Ty itself succeeded, 3498/// false otherwise. 3499/// 3500/// FIXME: what to do about extended qualifiers? 3501bool 3502BuiltinCandidateTypeSet::AddPointerWithMoreQualifiedTypeVariants(QualType Ty, 3503 const Qualifiers &VisibleQuals) { 3504 3505 // Insert this type. 3506 if (!PointerTypes.insert(Ty)) 3507 return false; 3508 3509 const PointerType *PointerTy = Ty->getAs<PointerType>(); 3510 assert(PointerTy && "type was not a pointer type!"); 3511 3512 QualType PointeeTy = PointerTy->getPointeeType(); 3513 // Don't add qualified variants of arrays. For one, they're not allowed 3514 // (the qualifier would sink to the element type), and for another, the 3515 // only overload situation where it matters is subscript or pointer +- int, 3516 // and those shouldn't have qualifier variants anyway. 3517 if (PointeeTy->isArrayType()) 3518 return true; 3519 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 3520 if (const ConstantArrayType *Array =Context.getAsConstantArrayType(PointeeTy)) 3521 BaseCVR = Array->getElementType().getCVRQualifiers(); 3522 bool hasVolatile = VisibleQuals.hasVolatile(); 3523 bool hasRestrict = VisibleQuals.hasRestrict(); 3524 3525 // Iterate through all strict supersets of BaseCVR. 3526 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 3527 if ((CVR | BaseCVR) != CVR) continue; 3528 // Skip over Volatile/Restrict if no Volatile/Restrict found anywhere 3529 // in the types. 3530 if ((CVR & Qualifiers::Volatile) && !hasVolatile) continue; 3531 if ((CVR & Qualifiers::Restrict) && !hasRestrict) continue; 3532 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 3533 PointerTypes.insert(Context.getPointerType(QPointeeTy)); 3534 } 3535 3536 return true; 3537} 3538 3539/// AddMemberPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty 3540/// to the set of pointer types along with any more-qualified variants of 3541/// that type. For example, if @p Ty is "int const *", this routine 3542/// will add "int const *", "int const volatile *", "int const 3543/// restrict *", and "int const volatile restrict *" to the set of 3544/// pointer types. Returns true if the add of @p Ty itself succeeded, 3545/// false otherwise. 3546/// 3547/// FIXME: what to do about extended qualifiers? 3548bool 3549BuiltinCandidateTypeSet::AddMemberPointerWithMoreQualifiedTypeVariants( 3550 QualType Ty) { 3551 // Insert this type. 3552 if (!MemberPointerTypes.insert(Ty)) 3553 return false; 3554 3555 const MemberPointerType *PointerTy = Ty->getAs<MemberPointerType>(); 3556 assert(PointerTy && "type was not a member pointer type!"); 3557 3558 QualType PointeeTy = PointerTy->getPointeeType(); 3559 // Don't add qualified variants of arrays. For one, they're not allowed 3560 // (the qualifier would sink to the element type), and for another, the 3561 // only overload situation where it matters is subscript or pointer +- int, 3562 // and those shouldn't have qualifier variants anyway. 3563 if (PointeeTy->isArrayType()) 3564 return true; 3565 const Type *ClassTy = PointerTy->getClass(); 3566 3567 // Iterate through all strict supersets of the pointee type's CVR 3568 // qualifiers. 3569 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 3570 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 3571 if ((CVR | BaseCVR) != CVR) continue; 3572 3573 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 3574 MemberPointerTypes.insert(Context.getMemberPointerType(QPointeeTy, ClassTy)); 3575 } 3576 3577 return true; 3578} 3579 3580/// AddTypesConvertedFrom - Add each of the types to which the type @p 3581/// Ty can be implicit converted to the given set of @p Types. We're 3582/// primarily interested in pointer types and enumeration types. We also 3583/// take member pointer types, for the conditional operator. 3584/// AllowUserConversions is true if we should look at the conversion 3585/// functions of a class type, and AllowExplicitConversions if we 3586/// should also include the explicit conversion functions of a class 3587/// type. 3588void 3589BuiltinCandidateTypeSet::AddTypesConvertedFrom(QualType Ty, 3590 SourceLocation Loc, 3591 bool AllowUserConversions, 3592 bool AllowExplicitConversions, 3593 const Qualifiers &VisibleQuals) { 3594 // Only deal with canonical types. 3595 Ty = Context.getCanonicalType(Ty); 3596 3597 // Look through reference types; they aren't part of the type of an 3598 // expression for the purposes of conversions. 3599 if (const ReferenceType *RefTy = Ty->getAs<ReferenceType>()) 3600 Ty = RefTy->getPointeeType(); 3601 3602 // We don't care about qualifiers on the type. 3603 Ty = Ty.getLocalUnqualifiedType(); 3604 3605 // If we're dealing with an array type, decay to the pointer. 3606 if (Ty->isArrayType()) 3607 Ty = SemaRef.Context.getArrayDecayedType(Ty); 3608 3609 if (const PointerType *PointerTy = Ty->getAs<PointerType>()) { 3610 QualType PointeeTy = PointerTy->getPointeeType(); 3611 3612 // Insert our type, and its more-qualified variants, into the set 3613 // of types. 3614 if (!AddPointerWithMoreQualifiedTypeVariants(Ty, VisibleQuals)) 3615 return; 3616 } else if (Ty->isMemberPointerType()) { 3617 // Member pointers are far easier, since the pointee can't be converted. 3618 if (!AddMemberPointerWithMoreQualifiedTypeVariants(Ty)) 3619 return; 3620 } else if (Ty->isEnumeralType()) { 3621 EnumerationTypes.insert(Ty); 3622 } else if (AllowUserConversions) { 3623 if (const RecordType *TyRec = Ty->getAs<RecordType>()) { 3624 if (SemaRef.RequireCompleteType(Loc, Ty, 0)) { 3625 // No conversion functions in incomplete types. 3626 return; 3627 } 3628 3629 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 3630 const UnresolvedSetImpl *Conversions 3631 = ClassDecl->getVisibleConversionFunctions(); 3632 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 3633 E = Conversions->end(); I != E; ++I) { 3634 NamedDecl *D = I.getDecl(); 3635 if (isa<UsingShadowDecl>(D)) 3636 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 3637 3638 // Skip conversion function templates; they don't tell us anything 3639 // about which builtin types we can convert to. 3640 if (isa<FunctionTemplateDecl>(D)) 3641 continue; 3642 3643 CXXConversionDecl *Conv = cast<CXXConversionDecl>(D); 3644 if (AllowExplicitConversions || !Conv->isExplicit()) { 3645 AddTypesConvertedFrom(Conv->getConversionType(), Loc, false, false, 3646 VisibleQuals); 3647 } 3648 } 3649 } 3650 } 3651} 3652 3653/// \brief Helper function for AddBuiltinOperatorCandidates() that adds 3654/// the volatile- and non-volatile-qualified assignment operators for the 3655/// given type to the candidate set. 3656static void AddBuiltinAssignmentOperatorCandidates(Sema &S, 3657 QualType T, 3658 Expr **Args, 3659 unsigned NumArgs, 3660 OverloadCandidateSet &CandidateSet) { 3661 QualType ParamTypes[2]; 3662 3663 // T& operator=(T&, T) 3664 ParamTypes[0] = S.Context.getLValueReferenceType(T); 3665 ParamTypes[1] = T; 3666 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3667 /*IsAssignmentOperator=*/true); 3668 3669 if (!S.Context.getCanonicalType(T).isVolatileQualified()) { 3670 // volatile T& operator=(volatile T&, T) 3671 ParamTypes[0] 3672 = S.Context.getLValueReferenceType(S.Context.getVolatileType(T)); 3673 ParamTypes[1] = T; 3674 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3675 /*IsAssignmentOperator=*/true); 3676 } 3677} 3678 3679/// CollectVRQualifiers - This routine returns Volatile/Restrict qualifiers, 3680/// if any, found in visible type conversion functions found in ArgExpr's type. 3681static Qualifiers CollectVRQualifiers(ASTContext &Context, Expr* ArgExpr) { 3682 Qualifiers VRQuals; 3683 const RecordType *TyRec; 3684 if (const MemberPointerType *RHSMPType = 3685 ArgExpr->getType()->getAs<MemberPointerType>()) 3686 TyRec = cast<RecordType>(RHSMPType->getClass()); 3687 else 3688 TyRec = ArgExpr->getType()->getAs<RecordType>(); 3689 if (!TyRec) { 3690 // Just to be safe, assume the worst case. 3691 VRQuals.addVolatile(); 3692 VRQuals.addRestrict(); 3693 return VRQuals; 3694 } 3695 3696 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 3697 if (!ClassDecl->hasDefinition()) 3698 return VRQuals; 3699 3700 const UnresolvedSetImpl *Conversions = 3701 ClassDecl->getVisibleConversionFunctions(); 3702 3703 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 3704 E = Conversions->end(); I != E; ++I) { 3705 NamedDecl *D = I.getDecl(); 3706 if (isa<UsingShadowDecl>(D)) 3707 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 3708 if (CXXConversionDecl *Conv = dyn_cast<CXXConversionDecl>(D)) { 3709 QualType CanTy = Context.getCanonicalType(Conv->getConversionType()); 3710 if (const ReferenceType *ResTypeRef = CanTy->getAs<ReferenceType>()) 3711 CanTy = ResTypeRef->getPointeeType(); 3712 // Need to go down the pointer/mempointer chain and add qualifiers 3713 // as see them. 3714 bool done = false; 3715 while (!done) { 3716 if (const PointerType *ResTypePtr = CanTy->getAs<PointerType>()) 3717 CanTy = ResTypePtr->getPointeeType(); 3718 else if (const MemberPointerType *ResTypeMPtr = 3719 CanTy->getAs<MemberPointerType>()) 3720 CanTy = ResTypeMPtr->getPointeeType(); 3721 else 3722 done = true; 3723 if (CanTy.isVolatileQualified()) 3724 VRQuals.addVolatile(); 3725 if (CanTy.isRestrictQualified()) 3726 VRQuals.addRestrict(); 3727 if (VRQuals.hasRestrict() && VRQuals.hasVolatile()) 3728 return VRQuals; 3729 } 3730 } 3731 } 3732 return VRQuals; 3733} 3734 3735/// AddBuiltinOperatorCandidates - Add the appropriate built-in 3736/// operator overloads to the candidate set (C++ [over.built]), based 3737/// on the operator @p Op and the arguments given. For example, if the 3738/// operator is a binary '+', this routine might add "int 3739/// operator+(int, int)" to cover integer addition. 3740void 3741Sema::AddBuiltinOperatorCandidates(OverloadedOperatorKind Op, 3742 SourceLocation OpLoc, 3743 Expr **Args, unsigned NumArgs, 3744 OverloadCandidateSet& CandidateSet) { 3745 // The set of "promoted arithmetic types", which are the arithmetic 3746 // types are that preserved by promotion (C++ [over.built]p2). Note 3747 // that the first few of these types are the promoted integral 3748 // types; these types need to be first. 3749 // FIXME: What about complex? 3750 const unsigned FirstIntegralType = 0; 3751 const unsigned LastIntegralType = 13; 3752 const unsigned FirstPromotedIntegralType = 7, 3753 LastPromotedIntegralType = 13; 3754 const unsigned FirstPromotedArithmeticType = 7, 3755 LastPromotedArithmeticType = 16; 3756 const unsigned NumArithmeticTypes = 16; 3757 QualType ArithmeticTypes[NumArithmeticTypes] = { 3758 Context.BoolTy, Context.CharTy, Context.WCharTy, 3759// FIXME: Context.Char16Ty, Context.Char32Ty, 3760 Context.SignedCharTy, Context.ShortTy, 3761 Context.UnsignedCharTy, Context.UnsignedShortTy, 3762 Context.IntTy, Context.LongTy, Context.LongLongTy, 3763 Context.UnsignedIntTy, Context.UnsignedLongTy, Context.UnsignedLongLongTy, 3764 Context.FloatTy, Context.DoubleTy, Context.LongDoubleTy 3765 }; 3766 assert(ArithmeticTypes[FirstPromotedIntegralType] == Context.IntTy && 3767 "Invalid first promoted integral type"); 3768 assert(ArithmeticTypes[LastPromotedIntegralType - 1] 3769 == Context.UnsignedLongLongTy && 3770 "Invalid last promoted integral type"); 3771 assert(ArithmeticTypes[FirstPromotedArithmeticType] == Context.IntTy && 3772 "Invalid first promoted arithmetic type"); 3773 assert(ArithmeticTypes[LastPromotedArithmeticType - 1] 3774 == Context.LongDoubleTy && 3775 "Invalid last promoted arithmetic type"); 3776 3777 // Find all of the types that the arguments can convert to, but only 3778 // if the operator we're looking at has built-in operator candidates 3779 // that make use of these types. 3780 Qualifiers VisibleTypeConversionsQuals; 3781 VisibleTypeConversionsQuals.addConst(); 3782 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 3783 VisibleTypeConversionsQuals += CollectVRQualifiers(Context, Args[ArgIdx]); 3784 3785 BuiltinCandidateTypeSet CandidateTypes(*this); 3786 if (Op == OO_Less || Op == OO_Greater || Op == OO_LessEqual || 3787 Op == OO_GreaterEqual || Op == OO_EqualEqual || Op == OO_ExclaimEqual || 3788 Op == OO_Plus || (Op == OO_Minus && NumArgs == 2) || Op == OO_Equal || 3789 Op == OO_PlusEqual || Op == OO_MinusEqual || Op == OO_Subscript || 3790 Op == OO_ArrowStar || Op == OO_PlusPlus || Op == OO_MinusMinus || 3791 (Op == OO_Star && NumArgs == 1) || Op == OO_Conditional) { 3792 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 3793 CandidateTypes.AddTypesConvertedFrom(Args[ArgIdx]->getType(), 3794 OpLoc, 3795 true, 3796 (Op == OO_Exclaim || 3797 Op == OO_AmpAmp || 3798 Op == OO_PipePipe), 3799 VisibleTypeConversionsQuals); 3800 } 3801 3802 bool isComparison = false; 3803 switch (Op) { 3804 case OO_None: 3805 case NUM_OVERLOADED_OPERATORS: 3806 assert(false && "Expected an overloaded operator"); 3807 break; 3808 3809 case OO_Star: // '*' is either unary or binary 3810 if (NumArgs == 1) 3811 goto UnaryStar; 3812 else 3813 goto BinaryStar; 3814 break; 3815 3816 case OO_Plus: // '+' is either unary or binary 3817 if (NumArgs == 1) 3818 goto UnaryPlus; 3819 else 3820 goto BinaryPlus; 3821 break; 3822 3823 case OO_Minus: // '-' is either unary or binary 3824 if (NumArgs == 1) 3825 goto UnaryMinus; 3826 else 3827 goto BinaryMinus; 3828 break; 3829 3830 case OO_Amp: // '&' is either unary or binary 3831 if (NumArgs == 1) 3832 goto UnaryAmp; 3833 else 3834 goto BinaryAmp; 3835 3836 case OO_PlusPlus: 3837 case OO_MinusMinus: 3838 // C++ [over.built]p3: 3839 // 3840 // For every pair (T, VQ), where T is an arithmetic type, and VQ 3841 // is either volatile or empty, there exist candidate operator 3842 // functions of the form 3843 // 3844 // VQ T& operator++(VQ T&); 3845 // T operator++(VQ T&, int); 3846 // 3847 // C++ [over.built]p4: 3848 // 3849 // For every pair (T, VQ), where T is an arithmetic type other 3850 // than bool, and VQ is either volatile or empty, there exist 3851 // candidate operator functions of the form 3852 // 3853 // VQ T& operator--(VQ T&); 3854 // T operator--(VQ T&, int); 3855 for (unsigned Arith = (Op == OO_PlusPlus? 0 : 1); 3856 Arith < NumArithmeticTypes; ++Arith) { 3857 QualType ArithTy = ArithmeticTypes[Arith]; 3858 QualType ParamTypes[2] 3859 = { Context.getLValueReferenceType(ArithTy), Context.IntTy }; 3860 3861 // Non-volatile version. 3862 if (NumArgs == 1) 3863 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3864 else 3865 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 3866 // heuristic to reduce number of builtin candidates in the set. 3867 // Add volatile version only if there are conversions to a volatile type. 3868 if (VisibleTypeConversionsQuals.hasVolatile()) { 3869 // Volatile version 3870 ParamTypes[0] 3871 = Context.getLValueReferenceType(Context.getVolatileType(ArithTy)); 3872 if (NumArgs == 1) 3873 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3874 else 3875 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 3876 } 3877 } 3878 3879 // C++ [over.built]p5: 3880 // 3881 // For every pair (T, VQ), where T is a cv-qualified or 3882 // cv-unqualified object type, and VQ is either volatile or 3883 // empty, there exist candidate operator functions of the form 3884 // 3885 // T*VQ& operator++(T*VQ&); 3886 // T*VQ& operator--(T*VQ&); 3887 // T* operator++(T*VQ&, int); 3888 // T* operator--(T*VQ&, int); 3889 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3890 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3891 // Skip pointer types that aren't pointers to object types. 3892 if (!(*Ptr)->getAs<PointerType>()->getPointeeType()->isObjectType()) 3893 continue; 3894 3895 QualType ParamTypes[2] = { 3896 Context.getLValueReferenceType(*Ptr), Context.IntTy 3897 }; 3898 3899 // Without volatile 3900 if (NumArgs == 1) 3901 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3902 else 3903 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3904 3905 if (!Context.getCanonicalType(*Ptr).isVolatileQualified() && 3906 VisibleTypeConversionsQuals.hasVolatile()) { 3907 // With volatile 3908 ParamTypes[0] 3909 = Context.getLValueReferenceType(Context.getVolatileType(*Ptr)); 3910 if (NumArgs == 1) 3911 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3912 else 3913 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3914 } 3915 } 3916 break; 3917 3918 UnaryStar: 3919 // C++ [over.built]p6: 3920 // For every cv-qualified or cv-unqualified object type T, there 3921 // exist candidate operator functions of the form 3922 // 3923 // T& operator*(T*); 3924 // 3925 // C++ [over.built]p7: 3926 // For every function type T, there exist candidate operator 3927 // functions of the form 3928 // T& operator*(T*); 3929 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3930 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3931 QualType ParamTy = *Ptr; 3932 QualType PointeeTy = ParamTy->getAs<PointerType>()->getPointeeType(); 3933 AddBuiltinCandidate(Context.getLValueReferenceType(PointeeTy), 3934 &ParamTy, Args, 1, CandidateSet); 3935 } 3936 break; 3937 3938 UnaryPlus: 3939 // C++ [over.built]p8: 3940 // For every type T, there exist candidate operator functions of 3941 // the form 3942 // 3943 // T* operator+(T*); 3944 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3945 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3946 QualType ParamTy = *Ptr; 3947 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet); 3948 } 3949 3950 // Fall through 3951 3952 UnaryMinus: 3953 // C++ [over.built]p9: 3954 // For every promoted arithmetic type T, there exist candidate 3955 // operator functions of the form 3956 // 3957 // T operator+(T); 3958 // T operator-(T); 3959 for (unsigned Arith = FirstPromotedArithmeticType; 3960 Arith < LastPromotedArithmeticType; ++Arith) { 3961 QualType ArithTy = ArithmeticTypes[Arith]; 3962 AddBuiltinCandidate(ArithTy, &ArithTy, Args, 1, CandidateSet); 3963 } 3964 break; 3965 3966 case OO_Tilde: 3967 // C++ [over.built]p10: 3968 // For every promoted integral type T, there exist candidate 3969 // operator functions of the form 3970 // 3971 // T operator~(T); 3972 for (unsigned Int = FirstPromotedIntegralType; 3973 Int < LastPromotedIntegralType; ++Int) { 3974 QualType IntTy = ArithmeticTypes[Int]; 3975 AddBuiltinCandidate(IntTy, &IntTy, Args, 1, CandidateSet); 3976 } 3977 break; 3978 3979 case OO_New: 3980 case OO_Delete: 3981 case OO_Array_New: 3982 case OO_Array_Delete: 3983 case OO_Call: 3984 assert(false && "Special operators don't use AddBuiltinOperatorCandidates"); 3985 break; 3986 3987 case OO_Comma: 3988 UnaryAmp: 3989 case OO_Arrow: 3990 // C++ [over.match.oper]p3: 3991 // -- For the operator ',', the unary operator '&', or the 3992 // operator '->', the built-in candidates set is empty. 3993 break; 3994 3995 case OO_EqualEqual: 3996 case OO_ExclaimEqual: 3997 // C++ [over.match.oper]p16: 3998 // For every pointer to member type T, there exist candidate operator 3999 // functions of the form 4000 // 4001 // bool operator==(T,T); 4002 // bool operator!=(T,T); 4003 for (BuiltinCandidateTypeSet::iterator 4004 MemPtr = CandidateTypes.member_pointer_begin(), 4005 MemPtrEnd = CandidateTypes.member_pointer_end(); 4006 MemPtr != MemPtrEnd; 4007 ++MemPtr) { 4008 QualType ParamTypes[2] = { *MemPtr, *MemPtr }; 4009 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 4010 } 4011 4012 // Fall through 4013 4014 case OO_Less: 4015 case OO_Greater: 4016 case OO_LessEqual: 4017 case OO_GreaterEqual: 4018 // C++ [over.built]p15: 4019 // 4020 // For every pointer or enumeration type T, there exist 4021 // candidate operator functions of the form 4022 // 4023 // bool operator<(T, T); 4024 // bool operator>(T, T); 4025 // bool operator<=(T, T); 4026 // bool operator>=(T, T); 4027 // bool operator==(T, T); 4028 // bool operator!=(T, T); 4029 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 4030 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4031 QualType ParamTypes[2] = { *Ptr, *Ptr }; 4032 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 4033 } 4034 for (BuiltinCandidateTypeSet::iterator Enum 4035 = CandidateTypes.enumeration_begin(); 4036 Enum != CandidateTypes.enumeration_end(); ++Enum) { 4037 QualType ParamTypes[2] = { *Enum, *Enum }; 4038 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 4039 } 4040 4041 // Fall through. 4042 isComparison = true; 4043 4044 BinaryPlus: 4045 BinaryMinus: 4046 if (!isComparison) { 4047 // We didn't fall through, so we must have OO_Plus or OO_Minus. 4048 4049 // C++ [over.built]p13: 4050 // 4051 // For every cv-qualified or cv-unqualified object type T 4052 // there exist candidate operator functions of the form 4053 // 4054 // T* operator+(T*, ptrdiff_t); 4055 // T& operator[](T*, ptrdiff_t); [BELOW] 4056 // T* operator-(T*, ptrdiff_t); 4057 // T* operator+(ptrdiff_t, T*); 4058 // T& operator[](ptrdiff_t, T*); [BELOW] 4059 // 4060 // C++ [over.built]p14: 4061 // 4062 // For every T, where T is a pointer to object type, there 4063 // exist candidate operator functions of the form 4064 // 4065 // ptrdiff_t operator-(T, T); 4066 for (BuiltinCandidateTypeSet::iterator Ptr 4067 = CandidateTypes.pointer_begin(); 4068 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4069 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 4070 4071 // operator+(T*, ptrdiff_t) or operator-(T*, ptrdiff_t) 4072 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 4073 4074 if (Op == OO_Plus) { 4075 // T* operator+(ptrdiff_t, T*); 4076 ParamTypes[0] = ParamTypes[1]; 4077 ParamTypes[1] = *Ptr; 4078 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 4079 } else { 4080 // ptrdiff_t operator-(T, T); 4081 ParamTypes[1] = *Ptr; 4082 AddBuiltinCandidate(Context.getPointerDiffType(), ParamTypes, 4083 Args, 2, CandidateSet); 4084 } 4085 } 4086 } 4087 // Fall through 4088 4089 case OO_Slash: 4090 BinaryStar: 4091 Conditional: 4092 // C++ [over.built]p12: 4093 // 4094 // For every pair of promoted arithmetic types L and R, there 4095 // exist candidate operator functions of the form 4096 // 4097 // LR operator*(L, R); 4098 // LR operator/(L, R); 4099 // LR operator+(L, R); 4100 // LR operator-(L, R); 4101 // bool operator<(L, R); 4102 // bool operator>(L, R); 4103 // bool operator<=(L, R); 4104 // bool operator>=(L, R); 4105 // bool operator==(L, R); 4106 // bool operator!=(L, R); 4107 // 4108 // where LR is the result of the usual arithmetic conversions 4109 // between types L and R. 4110 // 4111 // C++ [over.built]p24: 4112 // 4113 // For every pair of promoted arithmetic types L and R, there exist 4114 // candidate operator functions of the form 4115 // 4116 // LR operator?(bool, L, R); 4117 // 4118 // where LR is the result of the usual arithmetic conversions 4119 // between types L and R. 4120 // Our candidates ignore the first parameter. 4121 for (unsigned Left = FirstPromotedArithmeticType; 4122 Left < LastPromotedArithmeticType; ++Left) { 4123 for (unsigned Right = FirstPromotedArithmeticType; 4124 Right < LastPromotedArithmeticType; ++Right) { 4125 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 4126 QualType Result 4127 = isComparison 4128 ? Context.BoolTy 4129 : Context.UsualArithmeticConversionsType(LandR[0], LandR[1]); 4130 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 4131 } 4132 } 4133 break; 4134 4135 case OO_Percent: 4136 BinaryAmp: 4137 case OO_Caret: 4138 case OO_Pipe: 4139 case OO_LessLess: 4140 case OO_GreaterGreater: 4141 // C++ [over.built]p17: 4142 // 4143 // For every pair of promoted integral types L and R, there 4144 // exist candidate operator functions of the form 4145 // 4146 // LR operator%(L, R); 4147 // LR operator&(L, R); 4148 // LR operator^(L, R); 4149 // LR operator|(L, R); 4150 // L operator<<(L, R); 4151 // L operator>>(L, R); 4152 // 4153 // where LR is the result of the usual arithmetic conversions 4154 // between types L and R. 4155 for (unsigned Left = FirstPromotedIntegralType; 4156 Left < LastPromotedIntegralType; ++Left) { 4157 for (unsigned Right = FirstPromotedIntegralType; 4158 Right < LastPromotedIntegralType; ++Right) { 4159 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 4160 QualType Result = (Op == OO_LessLess || Op == OO_GreaterGreater) 4161 ? LandR[0] 4162 : Context.UsualArithmeticConversionsType(LandR[0], LandR[1]); 4163 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 4164 } 4165 } 4166 break; 4167 4168 case OO_Equal: 4169 // C++ [over.built]p20: 4170 // 4171 // For every pair (T, VQ), where T is an enumeration or 4172 // pointer to member type and VQ is either volatile or 4173 // empty, there exist candidate operator functions of the form 4174 // 4175 // VQ T& operator=(VQ T&, T); 4176 for (BuiltinCandidateTypeSet::iterator 4177 Enum = CandidateTypes.enumeration_begin(), 4178 EnumEnd = CandidateTypes.enumeration_end(); 4179 Enum != EnumEnd; ++Enum) 4180 AddBuiltinAssignmentOperatorCandidates(*this, *Enum, Args, 2, 4181 CandidateSet); 4182 for (BuiltinCandidateTypeSet::iterator 4183 MemPtr = CandidateTypes.member_pointer_begin(), 4184 MemPtrEnd = CandidateTypes.member_pointer_end(); 4185 MemPtr != MemPtrEnd; ++MemPtr) 4186 AddBuiltinAssignmentOperatorCandidates(*this, *MemPtr, Args, 2, 4187 CandidateSet); 4188 // Fall through. 4189 4190 case OO_PlusEqual: 4191 case OO_MinusEqual: 4192 // C++ [over.built]p19: 4193 // 4194 // For every pair (T, VQ), where T is any type and VQ is either 4195 // volatile or empty, there exist candidate operator functions 4196 // of the form 4197 // 4198 // T*VQ& operator=(T*VQ&, T*); 4199 // 4200 // C++ [over.built]p21: 4201 // 4202 // For every pair (T, VQ), where T is a cv-qualified or 4203 // cv-unqualified object type and VQ is either volatile or 4204 // empty, there exist candidate operator functions of the form 4205 // 4206 // T*VQ& operator+=(T*VQ&, ptrdiff_t); 4207 // T*VQ& operator-=(T*VQ&, ptrdiff_t); 4208 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 4209 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4210 QualType ParamTypes[2]; 4211 ParamTypes[1] = (Op == OO_Equal)? *Ptr : Context.getPointerDiffType(); 4212 4213 // non-volatile version 4214 ParamTypes[0] = Context.getLValueReferenceType(*Ptr); 4215 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4216 /*IsAssigmentOperator=*/Op == OO_Equal); 4217 4218 if (!Context.getCanonicalType(*Ptr).isVolatileQualified() && 4219 VisibleTypeConversionsQuals.hasVolatile()) { 4220 // volatile version 4221 ParamTypes[0] 4222 = Context.getLValueReferenceType(Context.getVolatileType(*Ptr)); 4223 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4224 /*IsAssigmentOperator=*/Op == OO_Equal); 4225 } 4226 } 4227 // Fall through. 4228 4229 case OO_StarEqual: 4230 case OO_SlashEqual: 4231 // C++ [over.built]p18: 4232 // 4233 // For every triple (L, VQ, R), where L is an arithmetic type, 4234 // VQ is either volatile or empty, and R is a promoted 4235 // arithmetic type, there exist candidate operator functions of 4236 // the form 4237 // 4238 // VQ L& operator=(VQ L&, R); 4239 // VQ L& operator*=(VQ L&, R); 4240 // VQ L& operator/=(VQ L&, R); 4241 // VQ L& operator+=(VQ L&, R); 4242 // VQ L& operator-=(VQ L&, R); 4243 for (unsigned Left = 0; Left < NumArithmeticTypes; ++Left) { 4244 for (unsigned Right = FirstPromotedArithmeticType; 4245 Right < LastPromotedArithmeticType; ++Right) { 4246 QualType ParamTypes[2]; 4247 ParamTypes[1] = ArithmeticTypes[Right]; 4248 4249 // Add this built-in operator as a candidate (VQ is empty). 4250 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 4251 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4252 /*IsAssigmentOperator=*/Op == OO_Equal); 4253 4254 // Add this built-in operator as a candidate (VQ is 'volatile'). 4255 if (VisibleTypeConversionsQuals.hasVolatile()) { 4256 ParamTypes[0] = Context.getVolatileType(ArithmeticTypes[Left]); 4257 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 4258 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4259 /*IsAssigmentOperator=*/Op == OO_Equal); 4260 } 4261 } 4262 } 4263 break; 4264 4265 case OO_PercentEqual: 4266 case OO_LessLessEqual: 4267 case OO_GreaterGreaterEqual: 4268 case OO_AmpEqual: 4269 case OO_CaretEqual: 4270 case OO_PipeEqual: 4271 // C++ [over.built]p22: 4272 // 4273 // For every triple (L, VQ, R), where L is an integral type, VQ 4274 // is either volatile or empty, and R is a promoted integral 4275 // type, there exist candidate operator functions of the form 4276 // 4277 // VQ L& operator%=(VQ L&, R); 4278 // VQ L& operator<<=(VQ L&, R); 4279 // VQ L& operator>>=(VQ L&, R); 4280 // VQ L& operator&=(VQ L&, R); 4281 // VQ L& operator^=(VQ L&, R); 4282 // VQ L& operator|=(VQ L&, R); 4283 for (unsigned Left = FirstIntegralType; Left < LastIntegralType; ++Left) { 4284 for (unsigned Right = FirstPromotedIntegralType; 4285 Right < LastPromotedIntegralType; ++Right) { 4286 QualType ParamTypes[2]; 4287 ParamTypes[1] = ArithmeticTypes[Right]; 4288 4289 // Add this built-in operator as a candidate (VQ is empty). 4290 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 4291 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 4292 if (VisibleTypeConversionsQuals.hasVolatile()) { 4293 // Add this built-in operator as a candidate (VQ is 'volatile'). 4294 ParamTypes[0] = ArithmeticTypes[Left]; 4295 ParamTypes[0] = Context.getVolatileType(ParamTypes[0]); 4296 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 4297 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 4298 } 4299 } 4300 } 4301 break; 4302 4303 case OO_Exclaim: { 4304 // C++ [over.operator]p23: 4305 // 4306 // There also exist candidate operator functions of the form 4307 // 4308 // bool operator!(bool); 4309 // bool operator&&(bool, bool); [BELOW] 4310 // bool operator||(bool, bool); [BELOW] 4311 QualType ParamTy = Context.BoolTy; 4312 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet, 4313 /*IsAssignmentOperator=*/false, 4314 /*NumContextualBoolArguments=*/1); 4315 break; 4316 } 4317 4318 case OO_AmpAmp: 4319 case OO_PipePipe: { 4320 // C++ [over.operator]p23: 4321 // 4322 // There also exist candidate operator functions of the form 4323 // 4324 // bool operator!(bool); [ABOVE] 4325 // bool operator&&(bool, bool); 4326 // bool operator||(bool, bool); 4327 QualType ParamTypes[2] = { Context.BoolTy, Context.BoolTy }; 4328 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet, 4329 /*IsAssignmentOperator=*/false, 4330 /*NumContextualBoolArguments=*/2); 4331 break; 4332 } 4333 4334 case OO_Subscript: 4335 // C++ [over.built]p13: 4336 // 4337 // For every cv-qualified or cv-unqualified object type T there 4338 // exist candidate operator functions of the form 4339 // 4340 // T* operator+(T*, ptrdiff_t); [ABOVE] 4341 // T& operator[](T*, ptrdiff_t); 4342 // T* operator-(T*, ptrdiff_t); [ABOVE] 4343 // T* operator+(ptrdiff_t, T*); [ABOVE] 4344 // T& operator[](ptrdiff_t, T*); 4345 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 4346 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4347 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 4348 QualType PointeeType = (*Ptr)->getAs<PointerType>()->getPointeeType(); 4349 QualType ResultTy = Context.getLValueReferenceType(PointeeType); 4350 4351 // T& operator[](T*, ptrdiff_t) 4352 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 4353 4354 // T& operator[](ptrdiff_t, T*); 4355 ParamTypes[0] = ParamTypes[1]; 4356 ParamTypes[1] = *Ptr; 4357 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 4358 } 4359 break; 4360 4361 case OO_ArrowStar: 4362 // C++ [over.built]p11: 4363 // For every quintuple (C1, C2, T, CV1, CV2), where C2 is a class type, 4364 // C1 is the same type as C2 or is a derived class of C2, T is an object 4365 // type or a function type, and CV1 and CV2 are cv-qualifier-seqs, 4366 // there exist candidate operator functions of the form 4367 // CV12 T& operator->*(CV1 C1*, CV2 T C2::*); 4368 // where CV12 is the union of CV1 and CV2. 4369 { 4370 for (BuiltinCandidateTypeSet::iterator Ptr = 4371 CandidateTypes.pointer_begin(); 4372 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4373 QualType C1Ty = (*Ptr); 4374 QualType C1; 4375 QualifierCollector Q1; 4376 if (const PointerType *PointerTy = C1Ty->getAs<PointerType>()) { 4377 C1 = QualType(Q1.strip(PointerTy->getPointeeType()), 0); 4378 if (!isa<RecordType>(C1)) 4379 continue; 4380 // heuristic to reduce number of builtin candidates in the set. 4381 // Add volatile/restrict version only if there are conversions to a 4382 // volatile/restrict type. 4383 if (!VisibleTypeConversionsQuals.hasVolatile() && Q1.hasVolatile()) 4384 continue; 4385 if (!VisibleTypeConversionsQuals.hasRestrict() && Q1.hasRestrict()) 4386 continue; 4387 } 4388 for (BuiltinCandidateTypeSet::iterator 4389 MemPtr = CandidateTypes.member_pointer_begin(), 4390 MemPtrEnd = CandidateTypes.member_pointer_end(); 4391 MemPtr != MemPtrEnd; ++MemPtr) { 4392 const MemberPointerType *mptr = cast<MemberPointerType>(*MemPtr); 4393 QualType C2 = QualType(mptr->getClass(), 0); 4394 C2 = C2.getUnqualifiedType(); 4395 if (C1 != C2 && !IsDerivedFrom(C1, C2)) 4396 break; 4397 QualType ParamTypes[2] = { *Ptr, *MemPtr }; 4398 // build CV12 T& 4399 QualType T = mptr->getPointeeType(); 4400 if (!VisibleTypeConversionsQuals.hasVolatile() && 4401 T.isVolatileQualified()) 4402 continue; 4403 if (!VisibleTypeConversionsQuals.hasRestrict() && 4404 T.isRestrictQualified()) 4405 continue; 4406 T = Q1.apply(T); 4407 QualType ResultTy = Context.getLValueReferenceType(T); 4408 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 4409 } 4410 } 4411 } 4412 break; 4413 4414 case OO_Conditional: 4415 // Note that we don't consider the first argument, since it has been 4416 // contextually converted to bool long ago. The candidates below are 4417 // therefore added as binary. 4418 // 4419 // C++ [over.built]p24: 4420 // For every type T, where T is a pointer or pointer-to-member type, 4421 // there exist candidate operator functions of the form 4422 // 4423 // T operator?(bool, T, T); 4424 // 4425 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(), 4426 E = CandidateTypes.pointer_end(); Ptr != E; ++Ptr) { 4427 QualType ParamTypes[2] = { *Ptr, *Ptr }; 4428 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 4429 } 4430 for (BuiltinCandidateTypeSet::iterator Ptr = 4431 CandidateTypes.member_pointer_begin(), 4432 E = CandidateTypes.member_pointer_end(); Ptr != E; ++Ptr) { 4433 QualType ParamTypes[2] = { *Ptr, *Ptr }; 4434 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 4435 } 4436 goto Conditional; 4437 } 4438} 4439 4440/// \brief Add function candidates found via argument-dependent lookup 4441/// to the set of overloading candidates. 4442/// 4443/// This routine performs argument-dependent name lookup based on the 4444/// given function name (which may also be an operator name) and adds 4445/// all of the overload candidates found by ADL to the overload 4446/// candidate set (C++ [basic.lookup.argdep]). 4447void 4448Sema::AddArgumentDependentLookupCandidates(DeclarationName Name, 4449 bool Operator, 4450 Expr **Args, unsigned NumArgs, 4451 const TemplateArgumentListInfo *ExplicitTemplateArgs, 4452 OverloadCandidateSet& CandidateSet, 4453 bool PartialOverloading) { 4454 ADLResult Fns; 4455 4456 // FIXME: This approach for uniquing ADL results (and removing 4457 // redundant candidates from the set) relies on pointer-equality, 4458 // which means we need to key off the canonical decl. However, 4459 // always going back to the canonical decl might not get us the 4460 // right set of default arguments. What default arguments are 4461 // we supposed to consider on ADL candidates, anyway? 4462 4463 // FIXME: Pass in the explicit template arguments? 4464 ArgumentDependentLookup(Name, Operator, Args, NumArgs, Fns); 4465 4466 // Erase all of the candidates we already knew about. 4467 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 4468 CandEnd = CandidateSet.end(); 4469 Cand != CandEnd; ++Cand) 4470 if (Cand->Function) { 4471 Fns.erase(Cand->Function); 4472 if (FunctionTemplateDecl *FunTmpl = Cand->Function->getPrimaryTemplate()) 4473 Fns.erase(FunTmpl); 4474 } 4475 4476 // For each of the ADL candidates we found, add it to the overload 4477 // set. 4478 for (ADLResult::iterator I = Fns.begin(), E = Fns.end(); I != E; ++I) { 4479 DeclAccessPair FoundDecl = DeclAccessPair::make(*I, AS_none); 4480 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*I)) { 4481 if (ExplicitTemplateArgs) 4482 continue; 4483 4484 AddOverloadCandidate(FD, FoundDecl, Args, NumArgs, CandidateSet, 4485 false, PartialOverloading); 4486 } else 4487 AddTemplateOverloadCandidate(cast<FunctionTemplateDecl>(*I), 4488 FoundDecl, ExplicitTemplateArgs, 4489 Args, NumArgs, CandidateSet); 4490 } 4491} 4492 4493/// isBetterOverloadCandidate - Determines whether the first overload 4494/// candidate is a better candidate than the second (C++ 13.3.3p1). 4495bool 4496Sema::isBetterOverloadCandidate(const OverloadCandidate& Cand1, 4497 const OverloadCandidate& Cand2, 4498 SourceLocation Loc) { 4499 // Define viable functions to be better candidates than non-viable 4500 // functions. 4501 if (!Cand2.Viable) 4502 return Cand1.Viable; 4503 else if (!Cand1.Viable) 4504 return false; 4505 4506 // C++ [over.match.best]p1: 4507 // 4508 // -- if F is a static member function, ICS1(F) is defined such 4509 // that ICS1(F) is neither better nor worse than ICS1(G) for 4510 // any function G, and, symmetrically, ICS1(G) is neither 4511 // better nor worse than ICS1(F). 4512 unsigned StartArg = 0; 4513 if (Cand1.IgnoreObjectArgument || Cand2.IgnoreObjectArgument) 4514 StartArg = 1; 4515 4516 // C++ [over.match.best]p1: 4517 // A viable function F1 is defined to be a better function than another 4518 // viable function F2 if for all arguments i, ICSi(F1) is not a worse 4519 // conversion sequence than ICSi(F2), and then... 4520 unsigned NumArgs = Cand1.Conversions.size(); 4521 assert(Cand2.Conversions.size() == NumArgs && "Overload candidate mismatch"); 4522 bool HasBetterConversion = false; 4523 for (unsigned ArgIdx = StartArg; ArgIdx < NumArgs; ++ArgIdx) { 4524 switch (CompareImplicitConversionSequences(Cand1.Conversions[ArgIdx], 4525 Cand2.Conversions[ArgIdx])) { 4526 case ImplicitConversionSequence::Better: 4527 // Cand1 has a better conversion sequence. 4528 HasBetterConversion = true; 4529 break; 4530 4531 case ImplicitConversionSequence::Worse: 4532 // Cand1 can't be better than Cand2. 4533 return false; 4534 4535 case ImplicitConversionSequence::Indistinguishable: 4536 // Do nothing. 4537 break; 4538 } 4539 } 4540 4541 // -- for some argument j, ICSj(F1) is a better conversion sequence than 4542 // ICSj(F2), or, if not that, 4543 if (HasBetterConversion) 4544 return true; 4545 4546 // - F1 is a non-template function and F2 is a function template 4547 // specialization, or, if not that, 4548 if (Cand1.Function && !Cand1.Function->getPrimaryTemplate() && 4549 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 4550 return true; 4551 4552 // -- F1 and F2 are function template specializations, and the function 4553 // template for F1 is more specialized than the template for F2 4554 // according to the partial ordering rules described in 14.5.5.2, or, 4555 // if not that, 4556 if (Cand1.Function && Cand1.Function->getPrimaryTemplate() && 4557 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 4558 if (FunctionTemplateDecl *BetterTemplate 4559 = getMoreSpecializedTemplate(Cand1.Function->getPrimaryTemplate(), 4560 Cand2.Function->getPrimaryTemplate(), 4561 Loc, 4562 isa<CXXConversionDecl>(Cand1.Function)? TPOC_Conversion 4563 : TPOC_Call)) 4564 return BetterTemplate == Cand1.Function->getPrimaryTemplate(); 4565 4566 // -- the context is an initialization by user-defined conversion 4567 // (see 8.5, 13.3.1.5) and the standard conversion sequence 4568 // from the return type of F1 to the destination type (i.e., 4569 // the type of the entity being initialized) is a better 4570 // conversion sequence than the standard conversion sequence 4571 // from the return type of F2 to the destination type. 4572 if (Cand1.Function && Cand2.Function && 4573 isa<CXXConversionDecl>(Cand1.Function) && 4574 isa<CXXConversionDecl>(Cand2.Function)) { 4575 switch (CompareStandardConversionSequences(Cand1.FinalConversion, 4576 Cand2.FinalConversion)) { 4577 case ImplicitConversionSequence::Better: 4578 // Cand1 has a better conversion sequence. 4579 return true; 4580 4581 case ImplicitConversionSequence::Worse: 4582 // Cand1 can't be better than Cand2. 4583 return false; 4584 4585 case ImplicitConversionSequence::Indistinguishable: 4586 // Do nothing 4587 break; 4588 } 4589 } 4590 4591 return false; 4592} 4593 4594/// \brief Computes the best viable function (C++ 13.3.3) 4595/// within an overload candidate set. 4596/// 4597/// \param CandidateSet the set of candidate functions. 4598/// 4599/// \param Loc the location of the function name (or operator symbol) for 4600/// which overload resolution occurs. 4601/// 4602/// \param Best f overload resolution was successful or found a deleted 4603/// function, Best points to the candidate function found. 4604/// 4605/// \returns The result of overload resolution. 4606OverloadingResult Sema::BestViableFunction(OverloadCandidateSet& CandidateSet, 4607 SourceLocation Loc, 4608 OverloadCandidateSet::iterator& Best) { 4609 // Find the best viable function. 4610 Best = CandidateSet.end(); 4611 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 4612 Cand != CandidateSet.end(); ++Cand) { 4613 if (Cand->Viable) { 4614 if (Best == CandidateSet.end() || 4615 isBetterOverloadCandidate(*Cand, *Best, Loc)) 4616 Best = Cand; 4617 } 4618 } 4619 4620 // If we didn't find any viable functions, abort. 4621 if (Best == CandidateSet.end()) 4622 return OR_No_Viable_Function; 4623 4624 // Make sure that this function is better than every other viable 4625 // function. If not, we have an ambiguity. 4626 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 4627 Cand != CandidateSet.end(); ++Cand) { 4628 if (Cand->Viable && 4629 Cand != Best && 4630 !isBetterOverloadCandidate(*Best, *Cand, Loc)) { 4631 Best = CandidateSet.end(); 4632 return OR_Ambiguous; 4633 } 4634 } 4635 4636 // Best is the best viable function. 4637 if (Best->Function && 4638 (Best->Function->isDeleted() || 4639 Best->Function->getAttr<UnavailableAttr>())) 4640 return OR_Deleted; 4641 4642 // C++ [basic.def.odr]p2: 4643 // An overloaded function is used if it is selected by overload resolution 4644 // when referred to from a potentially-evaluated expression. [Note: this 4645 // covers calls to named functions (5.2.2), operator overloading 4646 // (clause 13), user-defined conversions (12.3.2), allocation function for 4647 // placement new (5.3.4), as well as non-default initialization (8.5). 4648 if (Best->Function) 4649 MarkDeclarationReferenced(Loc, Best->Function); 4650 return OR_Success; 4651} 4652 4653namespace { 4654 4655enum OverloadCandidateKind { 4656 oc_function, 4657 oc_method, 4658 oc_constructor, 4659 oc_function_template, 4660 oc_method_template, 4661 oc_constructor_template, 4662 oc_implicit_default_constructor, 4663 oc_implicit_copy_constructor, 4664 oc_implicit_copy_assignment 4665}; 4666 4667OverloadCandidateKind ClassifyOverloadCandidate(Sema &S, 4668 FunctionDecl *Fn, 4669 std::string &Description) { 4670 bool isTemplate = false; 4671 4672 if (FunctionTemplateDecl *FunTmpl = Fn->getPrimaryTemplate()) { 4673 isTemplate = true; 4674 Description = S.getTemplateArgumentBindingsText( 4675 FunTmpl->getTemplateParameters(), *Fn->getTemplateSpecializationArgs()); 4676 } 4677 4678 if (CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(Fn)) { 4679 if (!Ctor->isImplicit()) 4680 return isTemplate ? oc_constructor_template : oc_constructor; 4681 4682 return Ctor->isCopyConstructor() ? oc_implicit_copy_constructor 4683 : oc_implicit_default_constructor; 4684 } 4685 4686 if (CXXMethodDecl *Meth = dyn_cast<CXXMethodDecl>(Fn)) { 4687 // This actually gets spelled 'candidate function' for now, but 4688 // it doesn't hurt to split it out. 4689 if (!Meth->isImplicit()) 4690 return isTemplate ? oc_method_template : oc_method; 4691 4692 assert(Meth->isCopyAssignment() 4693 && "implicit method is not copy assignment operator?"); 4694 return oc_implicit_copy_assignment; 4695 } 4696 4697 return isTemplate ? oc_function_template : oc_function; 4698} 4699 4700} // end anonymous namespace 4701 4702// Notes the location of an overload candidate. 4703void Sema::NoteOverloadCandidate(FunctionDecl *Fn) { 4704 std::string FnDesc; 4705 OverloadCandidateKind K = ClassifyOverloadCandidate(*this, Fn, FnDesc); 4706 Diag(Fn->getLocation(), diag::note_ovl_candidate) 4707 << (unsigned) K << FnDesc; 4708} 4709 4710/// Diagnoses an ambiguous conversion. The partial diagnostic is the 4711/// "lead" diagnostic; it will be given two arguments, the source and 4712/// target types of the conversion. 4713void Sema::DiagnoseAmbiguousConversion(const ImplicitConversionSequence &ICS, 4714 SourceLocation CaretLoc, 4715 const PartialDiagnostic &PDiag) { 4716 Diag(CaretLoc, PDiag) 4717 << ICS.Ambiguous.getFromType() << ICS.Ambiguous.getToType(); 4718 for (AmbiguousConversionSequence::const_iterator 4719 I = ICS.Ambiguous.begin(), E = ICS.Ambiguous.end(); I != E; ++I) { 4720 NoteOverloadCandidate(*I); 4721 } 4722} 4723 4724namespace { 4725 4726void DiagnoseBadConversion(Sema &S, OverloadCandidate *Cand, unsigned I) { 4727 const ImplicitConversionSequence &Conv = Cand->Conversions[I]; 4728 assert(Conv.isBad()); 4729 assert(Cand->Function && "for now, candidate must be a function"); 4730 FunctionDecl *Fn = Cand->Function; 4731 4732 // There's a conversion slot for the object argument if this is a 4733 // non-constructor method. Note that 'I' corresponds the 4734 // conversion-slot index. 4735 bool isObjectArgument = false; 4736 if (isa<CXXMethodDecl>(Fn) && !isa<CXXConstructorDecl>(Fn)) { 4737 if (I == 0) 4738 isObjectArgument = true; 4739 else 4740 I--; 4741 } 4742 4743 std::string FnDesc; 4744 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, FnDesc); 4745 4746 Expr *FromExpr = Conv.Bad.FromExpr; 4747 QualType FromTy = Conv.Bad.getFromType(); 4748 QualType ToTy = Conv.Bad.getToType(); 4749 4750 if (FromTy == S.Context.OverloadTy) { 4751 assert(FromExpr && "overload set argument came from implicit argument?"); 4752 Expr *E = FromExpr->IgnoreParens(); 4753 if (isa<UnaryOperator>(E)) 4754 E = cast<UnaryOperator>(E)->getSubExpr()->IgnoreParens(); 4755 DeclarationName Name = cast<OverloadExpr>(E)->getName(); 4756 4757 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_overload) 4758 << (unsigned) FnKind << FnDesc 4759 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 4760 << ToTy << Name << I+1; 4761 return; 4762 } 4763 4764 // Do some hand-waving analysis to see if the non-viability is due 4765 // to a qualifier mismatch. 4766 CanQualType CFromTy = S.Context.getCanonicalType(FromTy); 4767 CanQualType CToTy = S.Context.getCanonicalType(ToTy); 4768 if (CanQual<ReferenceType> RT = CToTy->getAs<ReferenceType>()) 4769 CToTy = RT->getPointeeType(); 4770 else { 4771 // TODO: detect and diagnose the full richness of const mismatches. 4772 if (CanQual<PointerType> FromPT = CFromTy->getAs<PointerType>()) 4773 if (CanQual<PointerType> ToPT = CToTy->getAs<PointerType>()) 4774 CFromTy = FromPT->getPointeeType(), CToTy = ToPT->getPointeeType(); 4775 } 4776 4777 if (CToTy.getUnqualifiedType() == CFromTy.getUnqualifiedType() && 4778 !CToTy.isAtLeastAsQualifiedAs(CFromTy)) { 4779 // It is dumb that we have to do this here. 4780 while (isa<ArrayType>(CFromTy)) 4781 CFromTy = CFromTy->getAs<ArrayType>()->getElementType(); 4782 while (isa<ArrayType>(CToTy)) 4783 CToTy = CFromTy->getAs<ArrayType>()->getElementType(); 4784 4785 Qualifiers FromQs = CFromTy.getQualifiers(); 4786 Qualifiers ToQs = CToTy.getQualifiers(); 4787 4788 if (FromQs.getAddressSpace() != ToQs.getAddressSpace()) { 4789 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_addrspace) 4790 << (unsigned) FnKind << FnDesc 4791 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 4792 << FromTy 4793 << FromQs.getAddressSpace() << ToQs.getAddressSpace() 4794 << (unsigned) isObjectArgument << I+1; 4795 return; 4796 } 4797 4798 unsigned CVR = FromQs.getCVRQualifiers() & ~ToQs.getCVRQualifiers(); 4799 assert(CVR && "unexpected qualifiers mismatch"); 4800 4801 if (isObjectArgument) { 4802 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr_this) 4803 << (unsigned) FnKind << FnDesc 4804 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 4805 << FromTy << (CVR - 1); 4806 } else { 4807 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr) 4808 << (unsigned) FnKind << FnDesc 4809 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 4810 << FromTy << (CVR - 1) << I+1; 4811 } 4812 return; 4813 } 4814 4815 // Diagnose references or pointers to incomplete types differently, 4816 // since it's far from impossible that the incompleteness triggered 4817 // the failure. 4818 QualType TempFromTy = FromTy.getNonReferenceType(); 4819 if (const PointerType *PTy = TempFromTy->getAs<PointerType>()) 4820 TempFromTy = PTy->getPointeeType(); 4821 if (TempFromTy->isIncompleteType()) { 4822 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_conv_incomplete) 4823 << (unsigned) FnKind << FnDesc 4824 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 4825 << FromTy << ToTy << (unsigned) isObjectArgument << I+1; 4826 return; 4827 } 4828 4829 // TODO: specialize more based on the kind of mismatch 4830 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_conv) 4831 << (unsigned) FnKind << FnDesc 4832 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 4833 << FromTy << ToTy << (unsigned) isObjectArgument << I+1; 4834} 4835 4836void DiagnoseArityMismatch(Sema &S, OverloadCandidate *Cand, 4837 unsigned NumFormalArgs) { 4838 // TODO: treat calls to a missing default constructor as a special case 4839 4840 FunctionDecl *Fn = Cand->Function; 4841 const FunctionProtoType *FnTy = Fn->getType()->getAs<FunctionProtoType>(); 4842 4843 unsigned MinParams = Fn->getMinRequiredArguments(); 4844 4845 // at least / at most / exactly 4846 unsigned mode, modeCount; 4847 if (NumFormalArgs < MinParams) { 4848 assert(Cand->FailureKind == ovl_fail_too_few_arguments); 4849 if (MinParams != FnTy->getNumArgs() || FnTy->isVariadic()) 4850 mode = 0; // "at least" 4851 else 4852 mode = 2; // "exactly" 4853 modeCount = MinParams; 4854 } else { 4855 assert(Cand->FailureKind == ovl_fail_too_many_arguments); 4856 if (MinParams != FnTy->getNumArgs()) 4857 mode = 1; // "at most" 4858 else 4859 mode = 2; // "exactly" 4860 modeCount = FnTy->getNumArgs(); 4861 } 4862 4863 std::string Description; 4864 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, Description); 4865 4866 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_arity) 4867 << (unsigned) FnKind << Description << mode << modeCount << NumFormalArgs; 4868} 4869 4870/// Diagnose a failed template-argument deduction. 4871void DiagnoseBadDeduction(Sema &S, OverloadCandidate *Cand, 4872 Expr **Args, unsigned NumArgs) { 4873 FunctionDecl *Fn = Cand->Function; // pattern 4874 4875 TemplateParameter Param = TemplateParameter::getFromOpaqueValue( 4876 Cand->DeductionFailure.TemplateParameter); 4877 4878 switch (Cand->DeductionFailure.Result) { 4879 case Sema::TDK_Success: 4880 llvm_unreachable("TDK_success while diagnosing bad deduction"); 4881 4882 case Sema::TDK_Incomplete: { 4883 NamedDecl *ParamD; 4884 (ParamD = Param.dyn_cast<TemplateTypeParmDecl*>()) || 4885 (ParamD = Param.dyn_cast<NonTypeTemplateParmDecl*>()) || 4886 (ParamD = Param.dyn_cast<TemplateTemplateParmDecl*>()); 4887 assert(ParamD && "no parameter found for incomplete deduction result"); 4888 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_incomplete_deduction) 4889 << ParamD->getDeclName(); 4890 return; 4891 } 4892 4893 // TODO: diagnose these individually, then kill off 4894 // note_ovl_candidate_bad_deduction, which is uselessly vague. 4895 case Sema::TDK_InstantiationDepth: 4896 case Sema::TDK_Inconsistent: 4897 case Sema::TDK_InconsistentQuals: 4898 case Sema::TDK_SubstitutionFailure: 4899 case Sema::TDK_NonDeducedMismatch: 4900 case Sema::TDK_TooManyArguments: 4901 case Sema::TDK_TooFewArguments: 4902 case Sema::TDK_InvalidExplicitArguments: 4903 case Sema::TDK_FailedOverloadResolution: 4904 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_deduction); 4905 return; 4906 } 4907} 4908 4909/// Generates a 'note' diagnostic for an overload candidate. We've 4910/// already generated a primary error at the call site. 4911/// 4912/// It really does need to be a single diagnostic with its caret 4913/// pointed at the candidate declaration. Yes, this creates some 4914/// major challenges of technical writing. Yes, this makes pointing 4915/// out problems with specific arguments quite awkward. It's still 4916/// better than generating twenty screens of text for every failed 4917/// overload. 4918/// 4919/// It would be great to be able to express per-candidate problems 4920/// more richly for those diagnostic clients that cared, but we'd 4921/// still have to be just as careful with the default diagnostics. 4922void NoteFunctionCandidate(Sema &S, OverloadCandidate *Cand, 4923 Expr **Args, unsigned NumArgs) { 4924 FunctionDecl *Fn = Cand->Function; 4925 4926 // Note deleted candidates, but only if they're viable. 4927 if (Cand->Viable && (Fn->isDeleted() || Fn->hasAttr<UnavailableAttr>())) { 4928 std::string FnDesc; 4929 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, FnDesc); 4930 4931 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_deleted) 4932 << FnKind << FnDesc << Fn->isDeleted(); 4933 return; 4934 } 4935 4936 // We don't really have anything else to say about viable candidates. 4937 if (Cand->Viable) { 4938 S.NoteOverloadCandidate(Fn); 4939 return; 4940 } 4941 4942 switch (Cand->FailureKind) { 4943 case ovl_fail_too_many_arguments: 4944 case ovl_fail_too_few_arguments: 4945 return DiagnoseArityMismatch(S, Cand, NumArgs); 4946 4947 case ovl_fail_bad_deduction: 4948 return DiagnoseBadDeduction(S, Cand, Args, NumArgs); 4949 4950 case ovl_fail_trivial_conversion: 4951 case ovl_fail_bad_final_conversion: 4952 case ovl_fail_final_conversion_not_exact: 4953 return S.NoteOverloadCandidate(Fn); 4954 4955 case ovl_fail_bad_conversion: { 4956 unsigned I = (Cand->IgnoreObjectArgument ? 1 : 0); 4957 for (unsigned N = Cand->Conversions.size(); I != N; ++I) 4958 if (Cand->Conversions[I].isBad()) 4959 return DiagnoseBadConversion(S, Cand, I); 4960 4961 // FIXME: this currently happens when we're called from SemaInit 4962 // when user-conversion overload fails. Figure out how to handle 4963 // those conditions and diagnose them well. 4964 return S.NoteOverloadCandidate(Fn); 4965 } 4966 } 4967} 4968 4969void NoteSurrogateCandidate(Sema &S, OverloadCandidate *Cand) { 4970 // Desugar the type of the surrogate down to a function type, 4971 // retaining as many typedefs as possible while still showing 4972 // the function type (and, therefore, its parameter types). 4973 QualType FnType = Cand->Surrogate->getConversionType(); 4974 bool isLValueReference = false; 4975 bool isRValueReference = false; 4976 bool isPointer = false; 4977 if (const LValueReferenceType *FnTypeRef = 4978 FnType->getAs<LValueReferenceType>()) { 4979 FnType = FnTypeRef->getPointeeType(); 4980 isLValueReference = true; 4981 } else if (const RValueReferenceType *FnTypeRef = 4982 FnType->getAs<RValueReferenceType>()) { 4983 FnType = FnTypeRef->getPointeeType(); 4984 isRValueReference = true; 4985 } 4986 if (const PointerType *FnTypePtr = FnType->getAs<PointerType>()) { 4987 FnType = FnTypePtr->getPointeeType(); 4988 isPointer = true; 4989 } 4990 // Desugar down to a function type. 4991 FnType = QualType(FnType->getAs<FunctionType>(), 0); 4992 // Reconstruct the pointer/reference as appropriate. 4993 if (isPointer) FnType = S.Context.getPointerType(FnType); 4994 if (isRValueReference) FnType = S.Context.getRValueReferenceType(FnType); 4995 if (isLValueReference) FnType = S.Context.getLValueReferenceType(FnType); 4996 4997 S.Diag(Cand->Surrogate->getLocation(), diag::note_ovl_surrogate_cand) 4998 << FnType; 4999} 5000 5001void NoteBuiltinOperatorCandidate(Sema &S, 5002 const char *Opc, 5003 SourceLocation OpLoc, 5004 OverloadCandidate *Cand) { 5005 assert(Cand->Conversions.size() <= 2 && "builtin operator is not binary"); 5006 std::string TypeStr("operator"); 5007 TypeStr += Opc; 5008 TypeStr += "("; 5009 TypeStr += Cand->BuiltinTypes.ParamTypes[0].getAsString(); 5010 if (Cand->Conversions.size() == 1) { 5011 TypeStr += ")"; 5012 S.Diag(OpLoc, diag::note_ovl_builtin_unary_candidate) << TypeStr; 5013 } else { 5014 TypeStr += ", "; 5015 TypeStr += Cand->BuiltinTypes.ParamTypes[1].getAsString(); 5016 TypeStr += ")"; 5017 S.Diag(OpLoc, diag::note_ovl_builtin_binary_candidate) << TypeStr; 5018 } 5019} 5020 5021void NoteAmbiguousUserConversions(Sema &S, SourceLocation OpLoc, 5022 OverloadCandidate *Cand) { 5023 unsigned NoOperands = Cand->Conversions.size(); 5024 for (unsigned ArgIdx = 0; ArgIdx < NoOperands; ++ArgIdx) { 5025 const ImplicitConversionSequence &ICS = Cand->Conversions[ArgIdx]; 5026 if (ICS.isBad()) break; // all meaningless after first invalid 5027 if (!ICS.isAmbiguous()) continue; 5028 5029 S.DiagnoseAmbiguousConversion(ICS, OpLoc, 5030 S.PDiag(diag::note_ambiguous_type_conversion)); 5031 } 5032} 5033 5034SourceLocation GetLocationForCandidate(const OverloadCandidate *Cand) { 5035 if (Cand->Function) 5036 return Cand->Function->getLocation(); 5037 if (Cand->IsSurrogate) 5038 return Cand->Surrogate->getLocation(); 5039 return SourceLocation(); 5040} 5041 5042struct CompareOverloadCandidatesForDisplay { 5043 Sema &S; 5044 CompareOverloadCandidatesForDisplay(Sema &S) : S(S) {} 5045 5046 bool operator()(const OverloadCandidate *L, 5047 const OverloadCandidate *R) { 5048 // Fast-path this check. 5049 if (L == R) return false; 5050 5051 // Order first by viability. 5052 if (L->Viable) { 5053 if (!R->Viable) return true; 5054 5055 // TODO: introduce a tri-valued comparison for overload 5056 // candidates. Would be more worthwhile if we had a sort 5057 // that could exploit it. 5058 if (S.isBetterOverloadCandidate(*L, *R, SourceLocation())) return true; 5059 if (S.isBetterOverloadCandidate(*R, *L, SourceLocation())) return false; 5060 } else if (R->Viable) 5061 return false; 5062 5063 assert(L->Viable == R->Viable); 5064 5065 // Criteria by which we can sort non-viable candidates: 5066 if (!L->Viable) { 5067 // 1. Arity mismatches come after other candidates. 5068 if (L->FailureKind == ovl_fail_too_many_arguments || 5069 L->FailureKind == ovl_fail_too_few_arguments) 5070 return false; 5071 if (R->FailureKind == ovl_fail_too_many_arguments || 5072 R->FailureKind == ovl_fail_too_few_arguments) 5073 return true; 5074 5075 // 2. Bad conversions come first and are ordered by the number 5076 // of bad conversions and quality of good conversions. 5077 if (L->FailureKind == ovl_fail_bad_conversion) { 5078 if (R->FailureKind != ovl_fail_bad_conversion) 5079 return true; 5080 5081 // If there's any ordering between the defined conversions... 5082 // FIXME: this might not be transitive. 5083 assert(L->Conversions.size() == R->Conversions.size()); 5084 5085 int leftBetter = 0; 5086 unsigned I = (L->IgnoreObjectArgument || R->IgnoreObjectArgument); 5087 for (unsigned E = L->Conversions.size(); I != E; ++I) { 5088 switch (S.CompareImplicitConversionSequences(L->Conversions[I], 5089 R->Conversions[I])) { 5090 case ImplicitConversionSequence::Better: 5091 leftBetter++; 5092 break; 5093 5094 case ImplicitConversionSequence::Worse: 5095 leftBetter--; 5096 break; 5097 5098 case ImplicitConversionSequence::Indistinguishable: 5099 break; 5100 } 5101 } 5102 if (leftBetter > 0) return true; 5103 if (leftBetter < 0) return false; 5104 5105 } else if (R->FailureKind == ovl_fail_bad_conversion) 5106 return false; 5107 5108 // TODO: others? 5109 } 5110 5111 // Sort everything else by location. 5112 SourceLocation LLoc = GetLocationForCandidate(L); 5113 SourceLocation RLoc = GetLocationForCandidate(R); 5114 5115 // Put candidates without locations (e.g. builtins) at the end. 5116 if (LLoc.isInvalid()) return false; 5117 if (RLoc.isInvalid()) return true; 5118 5119 return S.SourceMgr.isBeforeInTranslationUnit(LLoc, RLoc); 5120 } 5121}; 5122 5123/// CompleteNonViableCandidate - Normally, overload resolution only 5124/// computes up to the first 5125void CompleteNonViableCandidate(Sema &S, OverloadCandidate *Cand, 5126 Expr **Args, unsigned NumArgs) { 5127 assert(!Cand->Viable); 5128 5129 // Don't do anything on failures other than bad conversion. 5130 if (Cand->FailureKind != ovl_fail_bad_conversion) return; 5131 5132 // Skip forward to the first bad conversion. 5133 unsigned ConvIdx = (Cand->IgnoreObjectArgument ? 1 : 0); 5134 unsigned ConvCount = Cand->Conversions.size(); 5135 while (true) { 5136 assert(ConvIdx != ConvCount && "no bad conversion in candidate"); 5137 ConvIdx++; 5138 if (Cand->Conversions[ConvIdx - 1].isBad()) 5139 break; 5140 } 5141 5142 if (ConvIdx == ConvCount) 5143 return; 5144 5145 assert(!Cand->Conversions[ConvIdx].isInitialized() && 5146 "remaining conversion is initialized?"); 5147 5148 // FIXME: this should probably be preserved from the overload 5149 // operation somehow. 5150 bool SuppressUserConversions = false; 5151 5152 const FunctionProtoType* Proto; 5153 unsigned ArgIdx = ConvIdx; 5154 5155 if (Cand->IsSurrogate) { 5156 QualType ConvType 5157 = Cand->Surrogate->getConversionType().getNonReferenceType(); 5158 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 5159 ConvType = ConvPtrType->getPointeeType(); 5160 Proto = ConvType->getAs<FunctionProtoType>(); 5161 ArgIdx--; 5162 } else if (Cand->Function) { 5163 Proto = Cand->Function->getType()->getAs<FunctionProtoType>(); 5164 if (isa<CXXMethodDecl>(Cand->Function) && 5165 !isa<CXXConstructorDecl>(Cand->Function)) 5166 ArgIdx--; 5167 } else { 5168 // Builtin binary operator with a bad first conversion. 5169 assert(ConvCount <= 3); 5170 for (; ConvIdx != ConvCount; ++ConvIdx) 5171 Cand->Conversions[ConvIdx] 5172 = TryCopyInitialization(S, Args[ConvIdx], 5173 Cand->BuiltinTypes.ParamTypes[ConvIdx], 5174 SuppressUserConversions, 5175 /*ForceRValue=*/false, 5176 /*InOverloadResolution*/ true); 5177 return; 5178 } 5179 5180 // Fill in the rest of the conversions. 5181 unsigned NumArgsInProto = Proto->getNumArgs(); 5182 for (; ConvIdx != ConvCount; ++ConvIdx, ++ArgIdx) { 5183 if (ArgIdx < NumArgsInProto) 5184 Cand->Conversions[ConvIdx] 5185 = TryCopyInitialization(S, Args[ArgIdx], Proto->getArgType(ArgIdx), 5186 SuppressUserConversions, 5187 /*ForceRValue=*/false, 5188 /*InOverloadResolution=*/true); 5189 else 5190 Cand->Conversions[ConvIdx].setEllipsis(); 5191 } 5192} 5193 5194} // end anonymous namespace 5195 5196/// PrintOverloadCandidates - When overload resolution fails, prints 5197/// diagnostic messages containing the candidates in the candidate 5198/// set. 5199void 5200Sema::PrintOverloadCandidates(OverloadCandidateSet& CandidateSet, 5201 OverloadCandidateDisplayKind OCD, 5202 Expr **Args, unsigned NumArgs, 5203 const char *Opc, 5204 SourceLocation OpLoc) { 5205 // Sort the candidates by viability and position. Sorting directly would 5206 // be prohibitive, so we make a set of pointers and sort those. 5207 llvm::SmallVector<OverloadCandidate*, 32> Cands; 5208 if (OCD == OCD_AllCandidates) Cands.reserve(CandidateSet.size()); 5209 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 5210 LastCand = CandidateSet.end(); 5211 Cand != LastCand; ++Cand) { 5212 if (Cand->Viable) 5213 Cands.push_back(Cand); 5214 else if (OCD == OCD_AllCandidates) { 5215 CompleteNonViableCandidate(*this, Cand, Args, NumArgs); 5216 Cands.push_back(Cand); 5217 } 5218 } 5219 5220 std::sort(Cands.begin(), Cands.end(), 5221 CompareOverloadCandidatesForDisplay(*this)); 5222 5223 bool ReportedAmbiguousConversions = false; 5224 5225 llvm::SmallVectorImpl<OverloadCandidate*>::iterator I, E; 5226 for (I = Cands.begin(), E = Cands.end(); I != E; ++I) { 5227 OverloadCandidate *Cand = *I; 5228 5229 if (Cand->Function) 5230 NoteFunctionCandidate(*this, Cand, Args, NumArgs); 5231 else if (Cand->IsSurrogate) 5232 NoteSurrogateCandidate(*this, Cand); 5233 5234 // This a builtin candidate. We do not, in general, want to list 5235 // every possible builtin candidate. 5236 else if (Cand->Viable) { 5237 // Generally we only see ambiguities including viable builtin 5238 // operators if overload resolution got screwed up by an 5239 // ambiguous user-defined conversion. 5240 // 5241 // FIXME: It's quite possible for different conversions to see 5242 // different ambiguities, though. 5243 if (!ReportedAmbiguousConversions) { 5244 NoteAmbiguousUserConversions(*this, OpLoc, Cand); 5245 ReportedAmbiguousConversions = true; 5246 } 5247 5248 // If this is a viable builtin, print it. 5249 NoteBuiltinOperatorCandidate(*this, Opc, OpLoc, Cand); 5250 } 5251 } 5252} 5253 5254static bool CheckUnresolvedAccess(Sema &S, OverloadExpr *E, DeclAccessPair D) { 5255 if (isa<UnresolvedLookupExpr>(E)) 5256 return S.CheckUnresolvedLookupAccess(cast<UnresolvedLookupExpr>(E), D); 5257 5258 return S.CheckUnresolvedMemberAccess(cast<UnresolvedMemberExpr>(E), D); 5259} 5260 5261/// ResolveAddressOfOverloadedFunction - Try to resolve the address of 5262/// an overloaded function (C++ [over.over]), where @p From is an 5263/// expression with overloaded function type and @p ToType is the type 5264/// we're trying to resolve to. For example: 5265/// 5266/// @code 5267/// int f(double); 5268/// int f(int); 5269/// 5270/// int (*pfd)(double) = f; // selects f(double) 5271/// @endcode 5272/// 5273/// This routine returns the resulting FunctionDecl if it could be 5274/// resolved, and NULL otherwise. When @p Complain is true, this 5275/// routine will emit diagnostics if there is an error. 5276FunctionDecl * 5277Sema::ResolveAddressOfOverloadedFunction(Expr *From, QualType ToType, 5278 bool Complain, 5279 DeclAccessPair &FoundResult) { 5280 QualType FunctionType = ToType; 5281 bool IsMember = false; 5282 if (const PointerType *ToTypePtr = ToType->getAs<PointerType>()) 5283 FunctionType = ToTypePtr->getPointeeType(); 5284 else if (const ReferenceType *ToTypeRef = ToType->getAs<ReferenceType>()) 5285 FunctionType = ToTypeRef->getPointeeType(); 5286 else if (const MemberPointerType *MemTypePtr = 5287 ToType->getAs<MemberPointerType>()) { 5288 FunctionType = MemTypePtr->getPointeeType(); 5289 IsMember = true; 5290 } 5291 5292 // C++ [over.over]p1: 5293 // [...] [Note: any redundant set of parentheses surrounding the 5294 // overloaded function name is ignored (5.1). ] 5295 // C++ [over.over]p1: 5296 // [...] The overloaded function name can be preceded by the & 5297 // operator. 5298 OverloadExpr *OvlExpr = OverloadExpr::find(From).getPointer(); 5299 TemplateArgumentListInfo ETABuffer, *ExplicitTemplateArgs = 0; 5300 if (OvlExpr->hasExplicitTemplateArgs()) { 5301 OvlExpr->getExplicitTemplateArgs().copyInto(ETABuffer); 5302 ExplicitTemplateArgs = &ETABuffer; 5303 } 5304 5305 // We expect a pointer or reference to function, or a function pointer. 5306 FunctionType = Context.getCanonicalType(FunctionType).getUnqualifiedType(); 5307 if (!FunctionType->isFunctionType()) { 5308 if (Complain) 5309 Diag(From->getLocStart(), diag::err_addr_ovl_not_func_ptrref) 5310 << OvlExpr->getName() << ToType; 5311 5312 return 0; 5313 } 5314 5315 assert(From->getType() == Context.OverloadTy); 5316 5317 // Look through all of the overloaded functions, searching for one 5318 // whose type matches exactly. 5319 llvm::SmallVector<std::pair<DeclAccessPair, FunctionDecl*>, 4> Matches; 5320 llvm::SmallVector<FunctionDecl *, 4> NonMatches; 5321 5322 bool FoundNonTemplateFunction = false; 5323 for (UnresolvedSetIterator I = OvlExpr->decls_begin(), 5324 E = OvlExpr->decls_end(); I != E; ++I) { 5325 // Look through any using declarations to find the underlying function. 5326 NamedDecl *Fn = (*I)->getUnderlyingDecl(); 5327 5328 // C++ [over.over]p3: 5329 // Non-member functions and static member functions match 5330 // targets of type "pointer-to-function" or "reference-to-function." 5331 // Nonstatic member functions match targets of 5332 // type "pointer-to-member-function." 5333 // Note that according to DR 247, the containing class does not matter. 5334 5335 if (FunctionTemplateDecl *FunctionTemplate 5336 = dyn_cast<FunctionTemplateDecl>(Fn)) { 5337 if (CXXMethodDecl *Method 5338 = dyn_cast<CXXMethodDecl>(FunctionTemplate->getTemplatedDecl())) { 5339 // Skip non-static function templates when converting to pointer, and 5340 // static when converting to member pointer. 5341 if (Method->isStatic() == IsMember) 5342 continue; 5343 } else if (IsMember) 5344 continue; 5345 5346 // C++ [over.over]p2: 5347 // If the name is a function template, template argument deduction is 5348 // done (14.8.2.2), and if the argument deduction succeeds, the 5349 // resulting template argument list is used to generate a single 5350 // function template specialization, which is added to the set of 5351 // overloaded functions considered. 5352 // FIXME: We don't really want to build the specialization here, do we? 5353 FunctionDecl *Specialization = 0; 5354 TemplateDeductionInfo Info(Context, OvlExpr->getNameLoc()); 5355 if (TemplateDeductionResult Result 5356 = DeduceTemplateArguments(FunctionTemplate, ExplicitTemplateArgs, 5357 FunctionType, Specialization, Info)) { 5358 // FIXME: make a note of the failed deduction for diagnostics. 5359 (void)Result; 5360 } else { 5361 // FIXME: If the match isn't exact, shouldn't we just drop this as 5362 // a candidate? Find a testcase before changing the code. 5363 assert(FunctionType 5364 == Context.getCanonicalType(Specialization->getType())); 5365 Matches.push_back(std::make_pair(I.getPair(), 5366 cast<FunctionDecl>(Specialization->getCanonicalDecl()))); 5367 } 5368 5369 continue; 5370 } 5371 5372 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 5373 // Skip non-static functions when converting to pointer, and static 5374 // when converting to member pointer. 5375 if (Method->isStatic() == IsMember) 5376 continue; 5377 5378 // If we have explicit template arguments, skip non-templates. 5379 if (OvlExpr->hasExplicitTemplateArgs()) 5380 continue; 5381 } else if (IsMember) 5382 continue; 5383 5384 if (FunctionDecl *FunDecl = dyn_cast<FunctionDecl>(Fn)) { 5385 QualType ResultTy; 5386 if (Context.hasSameUnqualifiedType(FunctionType, FunDecl->getType()) || 5387 IsNoReturnConversion(Context, FunDecl->getType(), FunctionType, 5388 ResultTy)) { 5389 Matches.push_back(std::make_pair(I.getPair(), 5390 cast<FunctionDecl>(FunDecl->getCanonicalDecl()))); 5391 FoundNonTemplateFunction = true; 5392 } 5393 } 5394 } 5395 5396 // If there were 0 or 1 matches, we're done. 5397 if (Matches.empty()) { 5398 if (Complain) { 5399 Diag(From->getLocStart(), diag::err_addr_ovl_no_viable) 5400 << OvlExpr->getName() << FunctionType; 5401 for (UnresolvedSetIterator I = OvlExpr->decls_begin(), 5402 E = OvlExpr->decls_end(); 5403 I != E; ++I) 5404 if (FunctionDecl *F = dyn_cast<FunctionDecl>((*I)->getUnderlyingDecl())) 5405 NoteOverloadCandidate(F); 5406 } 5407 5408 return 0; 5409 } else if (Matches.size() == 1) { 5410 FunctionDecl *Result = Matches[0].second; 5411 FoundResult = Matches[0].first; 5412 MarkDeclarationReferenced(From->getLocStart(), Result); 5413 if (Complain) 5414 CheckAddressOfMemberAccess(OvlExpr, Matches[0].first); 5415 return Result; 5416 } 5417 5418 // C++ [over.over]p4: 5419 // If more than one function is selected, [...] 5420 if (!FoundNonTemplateFunction) { 5421 // [...] and any given function template specialization F1 is 5422 // eliminated if the set contains a second function template 5423 // specialization whose function template is more specialized 5424 // than the function template of F1 according to the partial 5425 // ordering rules of 14.5.5.2. 5426 5427 // The algorithm specified above is quadratic. We instead use a 5428 // two-pass algorithm (similar to the one used to identify the 5429 // best viable function in an overload set) that identifies the 5430 // best function template (if it exists). 5431 5432 UnresolvedSet<4> MatchesCopy; // TODO: avoid! 5433 for (unsigned I = 0, E = Matches.size(); I != E; ++I) 5434 MatchesCopy.addDecl(Matches[I].second, Matches[I].first.getAccess()); 5435 5436 UnresolvedSetIterator Result = 5437 getMostSpecialized(MatchesCopy.begin(), MatchesCopy.end(), 5438 TPOC_Other, From->getLocStart(), 5439 PDiag(), 5440 PDiag(diag::err_addr_ovl_ambiguous) 5441 << Matches[0].second->getDeclName(), 5442 PDiag(diag::note_ovl_candidate) 5443 << (unsigned) oc_function_template); 5444 assert(Result != MatchesCopy.end() && "no most-specialized template"); 5445 MarkDeclarationReferenced(From->getLocStart(), *Result); 5446 FoundResult = Matches[Result - MatchesCopy.begin()].first; 5447 if (Complain) 5448 CheckUnresolvedAccess(*this, OvlExpr, FoundResult); 5449 return cast<FunctionDecl>(*Result); 5450 } 5451 5452 // [...] any function template specializations in the set are 5453 // eliminated if the set also contains a non-template function, [...] 5454 for (unsigned I = 0, N = Matches.size(); I != N; ) { 5455 if (Matches[I].second->getPrimaryTemplate() == 0) 5456 ++I; 5457 else { 5458 Matches[I] = Matches[--N]; 5459 Matches.set_size(N); 5460 } 5461 } 5462 5463 // [...] After such eliminations, if any, there shall remain exactly one 5464 // selected function. 5465 if (Matches.size() == 1) { 5466 MarkDeclarationReferenced(From->getLocStart(), Matches[0].second); 5467 FoundResult = Matches[0].first; 5468 if (Complain) 5469 CheckUnresolvedAccess(*this, OvlExpr, Matches[0].first); 5470 return cast<FunctionDecl>(Matches[0].second); 5471 } 5472 5473 // FIXME: We should probably return the same thing that BestViableFunction 5474 // returns (even if we issue the diagnostics here). 5475 Diag(From->getLocStart(), diag::err_addr_ovl_ambiguous) 5476 << Matches[0].second->getDeclName(); 5477 for (unsigned I = 0, E = Matches.size(); I != E; ++I) 5478 NoteOverloadCandidate(Matches[I].second); 5479 return 0; 5480} 5481 5482/// \brief Given an expression that refers to an overloaded function, try to 5483/// resolve that overloaded function expression down to a single function. 5484/// 5485/// This routine can only resolve template-ids that refer to a single function 5486/// template, where that template-id refers to a single template whose template 5487/// arguments are either provided by the template-id or have defaults, 5488/// as described in C++0x [temp.arg.explicit]p3. 5489FunctionDecl *Sema::ResolveSingleFunctionTemplateSpecialization(Expr *From) { 5490 // C++ [over.over]p1: 5491 // [...] [Note: any redundant set of parentheses surrounding the 5492 // overloaded function name is ignored (5.1). ] 5493 // C++ [over.over]p1: 5494 // [...] The overloaded function name can be preceded by the & 5495 // operator. 5496 5497 if (From->getType() != Context.OverloadTy) 5498 return 0; 5499 5500 OverloadExpr *OvlExpr = OverloadExpr::find(From).getPointer(); 5501 5502 // If we didn't actually find any template-ids, we're done. 5503 if (!OvlExpr->hasExplicitTemplateArgs()) 5504 return 0; 5505 5506 TemplateArgumentListInfo ExplicitTemplateArgs; 5507 OvlExpr->getExplicitTemplateArgs().copyInto(ExplicitTemplateArgs); 5508 5509 // Look through all of the overloaded functions, searching for one 5510 // whose type matches exactly. 5511 FunctionDecl *Matched = 0; 5512 for (UnresolvedSetIterator I = OvlExpr->decls_begin(), 5513 E = OvlExpr->decls_end(); I != E; ++I) { 5514 // C++0x [temp.arg.explicit]p3: 5515 // [...] In contexts where deduction is done and fails, or in contexts 5516 // where deduction is not done, if a template argument list is 5517 // specified and it, along with any default template arguments, 5518 // identifies a single function template specialization, then the 5519 // template-id is an lvalue for the function template specialization. 5520 FunctionTemplateDecl *FunctionTemplate = cast<FunctionTemplateDecl>(*I); 5521 5522 // C++ [over.over]p2: 5523 // If the name is a function template, template argument deduction is 5524 // done (14.8.2.2), and if the argument deduction succeeds, the 5525 // resulting template argument list is used to generate a single 5526 // function template specialization, which is added to the set of 5527 // overloaded functions considered. 5528 FunctionDecl *Specialization = 0; 5529 TemplateDeductionInfo Info(Context, OvlExpr->getNameLoc()); 5530 if (TemplateDeductionResult Result 5531 = DeduceTemplateArguments(FunctionTemplate, &ExplicitTemplateArgs, 5532 Specialization, Info)) { 5533 // FIXME: make a note of the failed deduction for diagnostics. 5534 (void)Result; 5535 continue; 5536 } 5537 5538 // Multiple matches; we can't resolve to a single declaration. 5539 if (Matched) 5540 return 0; 5541 5542 Matched = Specialization; 5543 } 5544 5545 return Matched; 5546} 5547 5548/// \brief Add a single candidate to the overload set. 5549static void AddOverloadedCallCandidate(Sema &S, 5550 DeclAccessPair FoundDecl, 5551 const TemplateArgumentListInfo *ExplicitTemplateArgs, 5552 Expr **Args, unsigned NumArgs, 5553 OverloadCandidateSet &CandidateSet, 5554 bool PartialOverloading) { 5555 NamedDecl *Callee = FoundDecl.getDecl(); 5556 if (isa<UsingShadowDecl>(Callee)) 5557 Callee = cast<UsingShadowDecl>(Callee)->getTargetDecl(); 5558 5559 if (FunctionDecl *Func = dyn_cast<FunctionDecl>(Callee)) { 5560 assert(!ExplicitTemplateArgs && "Explicit template arguments?"); 5561 S.AddOverloadCandidate(Func, FoundDecl, Args, NumArgs, CandidateSet, 5562 false, PartialOverloading); 5563 return; 5564 } 5565 5566 if (FunctionTemplateDecl *FuncTemplate 5567 = dyn_cast<FunctionTemplateDecl>(Callee)) { 5568 S.AddTemplateOverloadCandidate(FuncTemplate, FoundDecl, 5569 ExplicitTemplateArgs, 5570 Args, NumArgs, CandidateSet); 5571 return; 5572 } 5573 5574 assert(false && "unhandled case in overloaded call candidate"); 5575 5576 // do nothing? 5577} 5578 5579/// \brief Add the overload candidates named by callee and/or found by argument 5580/// dependent lookup to the given overload set. 5581void Sema::AddOverloadedCallCandidates(UnresolvedLookupExpr *ULE, 5582 Expr **Args, unsigned NumArgs, 5583 OverloadCandidateSet &CandidateSet, 5584 bool PartialOverloading) { 5585 5586#ifndef NDEBUG 5587 // Verify that ArgumentDependentLookup is consistent with the rules 5588 // in C++0x [basic.lookup.argdep]p3: 5589 // 5590 // Let X be the lookup set produced by unqualified lookup (3.4.1) 5591 // and let Y be the lookup set produced by argument dependent 5592 // lookup (defined as follows). If X contains 5593 // 5594 // -- a declaration of a class member, or 5595 // 5596 // -- a block-scope function declaration that is not a 5597 // using-declaration, or 5598 // 5599 // -- a declaration that is neither a function or a function 5600 // template 5601 // 5602 // then Y is empty. 5603 5604 if (ULE->requiresADL()) { 5605 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(), 5606 E = ULE->decls_end(); I != E; ++I) { 5607 assert(!(*I)->getDeclContext()->isRecord()); 5608 assert(isa<UsingShadowDecl>(*I) || 5609 !(*I)->getDeclContext()->isFunctionOrMethod()); 5610 assert((*I)->getUnderlyingDecl()->isFunctionOrFunctionTemplate()); 5611 } 5612 } 5613#endif 5614 5615 // It would be nice to avoid this copy. 5616 TemplateArgumentListInfo TABuffer; 5617 const TemplateArgumentListInfo *ExplicitTemplateArgs = 0; 5618 if (ULE->hasExplicitTemplateArgs()) { 5619 ULE->copyTemplateArgumentsInto(TABuffer); 5620 ExplicitTemplateArgs = &TABuffer; 5621 } 5622 5623 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(), 5624 E = ULE->decls_end(); I != E; ++I) 5625 AddOverloadedCallCandidate(*this, I.getPair(), ExplicitTemplateArgs, 5626 Args, NumArgs, CandidateSet, 5627 PartialOverloading); 5628 5629 if (ULE->requiresADL()) 5630 AddArgumentDependentLookupCandidates(ULE->getName(), /*Operator*/ false, 5631 Args, NumArgs, 5632 ExplicitTemplateArgs, 5633 CandidateSet, 5634 PartialOverloading); 5635} 5636 5637static Sema::OwningExprResult Destroy(Sema &SemaRef, Expr *Fn, 5638 Expr **Args, unsigned NumArgs) { 5639 Fn->Destroy(SemaRef.Context); 5640 for (unsigned Arg = 0; Arg < NumArgs; ++Arg) 5641 Args[Arg]->Destroy(SemaRef.Context); 5642 return SemaRef.ExprError(); 5643} 5644 5645/// Attempts to recover from a call where no functions were found. 5646/// 5647/// Returns true if new candidates were found. 5648static Sema::OwningExprResult 5649BuildRecoveryCallExpr(Sema &SemaRef, Scope *S, Expr *Fn, 5650 UnresolvedLookupExpr *ULE, 5651 SourceLocation LParenLoc, 5652 Expr **Args, unsigned NumArgs, 5653 SourceLocation *CommaLocs, 5654 SourceLocation RParenLoc) { 5655 5656 CXXScopeSpec SS; 5657 if (ULE->getQualifier()) { 5658 SS.setScopeRep(ULE->getQualifier()); 5659 SS.setRange(ULE->getQualifierRange()); 5660 } 5661 5662 TemplateArgumentListInfo TABuffer; 5663 const TemplateArgumentListInfo *ExplicitTemplateArgs = 0; 5664 if (ULE->hasExplicitTemplateArgs()) { 5665 ULE->copyTemplateArgumentsInto(TABuffer); 5666 ExplicitTemplateArgs = &TABuffer; 5667 } 5668 5669 LookupResult R(SemaRef, ULE->getName(), ULE->getNameLoc(), 5670 Sema::LookupOrdinaryName); 5671 if (SemaRef.DiagnoseEmptyLookup(S, SS, R)) 5672 return Destroy(SemaRef, Fn, Args, NumArgs); 5673 5674 assert(!R.empty() && "lookup results empty despite recovery"); 5675 5676 // Build an implicit member call if appropriate. Just drop the 5677 // casts and such from the call, we don't really care. 5678 Sema::OwningExprResult NewFn = SemaRef.ExprError(); 5679 if ((*R.begin())->isCXXClassMember()) 5680 NewFn = SemaRef.BuildPossibleImplicitMemberExpr(SS, R, ExplicitTemplateArgs); 5681 else if (ExplicitTemplateArgs) 5682 NewFn = SemaRef.BuildTemplateIdExpr(SS, R, false, *ExplicitTemplateArgs); 5683 else 5684 NewFn = SemaRef.BuildDeclarationNameExpr(SS, R, false); 5685 5686 if (NewFn.isInvalid()) 5687 return Destroy(SemaRef, Fn, Args, NumArgs); 5688 5689 Fn->Destroy(SemaRef.Context); 5690 5691 // This shouldn't cause an infinite loop because we're giving it 5692 // an expression with non-empty lookup results, which should never 5693 // end up here. 5694 return SemaRef.ActOnCallExpr(/*Scope*/ 0, move(NewFn), LParenLoc, 5695 Sema::MultiExprArg(SemaRef, (void**) Args, NumArgs), 5696 CommaLocs, RParenLoc); 5697} 5698 5699/// ResolveOverloadedCallFn - Given the call expression that calls Fn 5700/// (which eventually refers to the declaration Func) and the call 5701/// arguments Args/NumArgs, attempt to resolve the function call down 5702/// to a specific function. If overload resolution succeeds, returns 5703/// the function declaration produced by overload 5704/// resolution. Otherwise, emits diagnostics, deletes all of the 5705/// arguments and Fn, and returns NULL. 5706Sema::OwningExprResult 5707Sema::BuildOverloadedCallExpr(Scope *S, Expr *Fn, UnresolvedLookupExpr *ULE, 5708 SourceLocation LParenLoc, 5709 Expr **Args, unsigned NumArgs, 5710 SourceLocation *CommaLocs, 5711 SourceLocation RParenLoc) { 5712#ifndef NDEBUG 5713 if (ULE->requiresADL()) { 5714 // To do ADL, we must have found an unqualified name. 5715 assert(!ULE->getQualifier() && "qualified name with ADL"); 5716 5717 // We don't perform ADL for implicit declarations of builtins. 5718 // Verify that this was correctly set up. 5719 FunctionDecl *F; 5720 if (ULE->decls_begin() + 1 == ULE->decls_end() && 5721 (F = dyn_cast<FunctionDecl>(*ULE->decls_begin())) && 5722 F->getBuiltinID() && F->isImplicit()) 5723 assert(0 && "performing ADL for builtin"); 5724 5725 // We don't perform ADL in C. 5726 assert(getLangOptions().CPlusPlus && "ADL enabled in C"); 5727 } 5728#endif 5729 5730 OverloadCandidateSet CandidateSet(Fn->getExprLoc()); 5731 5732 // Add the functions denoted by the callee to the set of candidate 5733 // functions, including those from argument-dependent lookup. 5734 AddOverloadedCallCandidates(ULE, Args, NumArgs, CandidateSet); 5735 5736 // If we found nothing, try to recover. 5737 // AddRecoveryCallCandidates diagnoses the error itself, so we just 5738 // bailout out if it fails. 5739 if (CandidateSet.empty()) 5740 return BuildRecoveryCallExpr(*this, S, Fn, ULE, LParenLoc, Args, NumArgs, 5741 CommaLocs, RParenLoc); 5742 5743 OverloadCandidateSet::iterator Best; 5744 switch (BestViableFunction(CandidateSet, Fn->getLocStart(), Best)) { 5745 case OR_Success: { 5746 FunctionDecl *FDecl = Best->Function; 5747 CheckUnresolvedLookupAccess(ULE, Best->FoundDecl); 5748 Fn = FixOverloadedFunctionReference(Fn, Best->FoundDecl, FDecl); 5749 return BuildResolvedCallExpr(Fn, FDecl, LParenLoc, Args, NumArgs, RParenLoc); 5750 } 5751 5752 case OR_No_Viable_Function: 5753 Diag(Fn->getSourceRange().getBegin(), 5754 diag::err_ovl_no_viable_function_in_call) 5755 << ULE->getName() << Fn->getSourceRange(); 5756 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 5757 break; 5758 5759 case OR_Ambiguous: 5760 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_ambiguous_call) 5761 << ULE->getName() << Fn->getSourceRange(); 5762 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, NumArgs); 5763 break; 5764 5765 case OR_Deleted: 5766 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_deleted_call) 5767 << Best->Function->isDeleted() 5768 << ULE->getName() 5769 << Fn->getSourceRange(); 5770 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 5771 break; 5772 } 5773 5774 // Overload resolution failed. Destroy all of the subexpressions and 5775 // return NULL. 5776 Fn->Destroy(Context); 5777 for (unsigned Arg = 0; Arg < NumArgs; ++Arg) 5778 Args[Arg]->Destroy(Context); 5779 return ExprError(); 5780} 5781 5782static bool IsOverloaded(const UnresolvedSetImpl &Functions) { 5783 return Functions.size() > 1 || 5784 (Functions.size() == 1 && isa<FunctionTemplateDecl>(*Functions.begin())); 5785} 5786 5787/// \brief Create a unary operation that may resolve to an overloaded 5788/// operator. 5789/// 5790/// \param OpLoc The location of the operator itself (e.g., '*'). 5791/// 5792/// \param OpcIn The UnaryOperator::Opcode that describes this 5793/// operator. 5794/// 5795/// \param Functions The set of non-member functions that will be 5796/// considered by overload resolution. The caller needs to build this 5797/// set based on the context using, e.g., 5798/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 5799/// set should not contain any member functions; those will be added 5800/// by CreateOverloadedUnaryOp(). 5801/// 5802/// \param input The input argument. 5803Sema::OwningExprResult 5804Sema::CreateOverloadedUnaryOp(SourceLocation OpLoc, unsigned OpcIn, 5805 const UnresolvedSetImpl &Fns, 5806 ExprArg input) { 5807 UnaryOperator::Opcode Opc = static_cast<UnaryOperator::Opcode>(OpcIn); 5808 Expr *Input = (Expr *)input.get(); 5809 5810 OverloadedOperatorKind Op = UnaryOperator::getOverloadedOperator(Opc); 5811 assert(Op != OO_None && "Invalid opcode for overloaded unary operator"); 5812 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 5813 5814 Expr *Args[2] = { Input, 0 }; 5815 unsigned NumArgs = 1; 5816 5817 // For post-increment and post-decrement, add the implicit '0' as 5818 // the second argument, so that we know this is a post-increment or 5819 // post-decrement. 5820 if (Opc == UnaryOperator::PostInc || Opc == UnaryOperator::PostDec) { 5821 llvm::APSInt Zero(Context.getTypeSize(Context.IntTy), false); 5822 Args[1] = new (Context) IntegerLiteral(Zero, Context.IntTy, 5823 SourceLocation()); 5824 NumArgs = 2; 5825 } 5826 5827 if (Input->isTypeDependent()) { 5828 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 5829 UnresolvedLookupExpr *Fn 5830 = UnresolvedLookupExpr::Create(Context, /*Dependent*/ true, NamingClass, 5831 0, SourceRange(), OpName, OpLoc, 5832 /*ADL*/ true, IsOverloaded(Fns)); 5833 Fn->addDecls(Fns.begin(), Fns.end()); 5834 5835 input.release(); 5836 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 5837 &Args[0], NumArgs, 5838 Context.DependentTy, 5839 OpLoc)); 5840 } 5841 5842 // Build an empty overload set. 5843 OverloadCandidateSet CandidateSet(OpLoc); 5844 5845 // Add the candidates from the given function set. 5846 AddFunctionCandidates(Fns, &Args[0], NumArgs, CandidateSet, false); 5847 5848 // Add operator candidates that are member functions. 5849 AddMemberOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 5850 5851 // Add candidates from ADL. 5852 AddArgumentDependentLookupCandidates(OpName, /*Operator*/ true, 5853 Args, NumArgs, 5854 /*ExplicitTemplateArgs*/ 0, 5855 CandidateSet); 5856 5857 // Add builtin operator candidates. 5858 AddBuiltinOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 5859 5860 // Perform overload resolution. 5861 OverloadCandidateSet::iterator Best; 5862 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 5863 case OR_Success: { 5864 // We found a built-in operator or an overloaded operator. 5865 FunctionDecl *FnDecl = Best->Function; 5866 5867 if (FnDecl) { 5868 // We matched an overloaded operator. Build a call to that 5869 // operator. 5870 5871 // Convert the arguments. 5872 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 5873 CheckMemberOperatorAccess(OpLoc, Args[0], 0, Best->FoundDecl); 5874 5875 if (PerformObjectArgumentInitialization(Input, /*Qualifier=*/0, 5876 Best->FoundDecl, Method)) 5877 return ExprError(); 5878 } else { 5879 // Convert the arguments. 5880 OwningExprResult InputInit 5881 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 5882 FnDecl->getParamDecl(0)), 5883 SourceLocation(), 5884 move(input)); 5885 if (InputInit.isInvalid()) 5886 return ExprError(); 5887 5888 input = move(InputInit); 5889 Input = (Expr *)input.get(); 5890 } 5891 5892 // Determine the result type 5893 QualType ResultTy = FnDecl->getResultType().getNonReferenceType(); 5894 5895 // Build the actual expression node. 5896 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 5897 SourceLocation()); 5898 UsualUnaryConversions(FnExpr); 5899 5900 input.release(); 5901 Args[0] = Input; 5902 ExprOwningPtr<CallExpr> TheCall(this, 5903 new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 5904 Args, NumArgs, ResultTy, OpLoc)); 5905 5906 if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall.get(), 5907 FnDecl)) 5908 return ExprError(); 5909 5910 return MaybeBindToTemporary(TheCall.release()); 5911 } else { 5912 // We matched a built-in operator. Convert the arguments, then 5913 // break out so that we will build the appropriate built-in 5914 // operator node. 5915 if (PerformImplicitConversion(Input, Best->BuiltinTypes.ParamTypes[0], 5916 Best->Conversions[0], AA_Passing)) 5917 return ExprError(); 5918 5919 break; 5920 } 5921 } 5922 5923 case OR_No_Viable_Function: 5924 // No viable function; fall through to handling this as a 5925 // built-in operator, which will produce an error message for us. 5926 break; 5927 5928 case OR_Ambiguous: 5929 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 5930 << UnaryOperator::getOpcodeStr(Opc) 5931 << Input->getSourceRange(); 5932 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, NumArgs, 5933 UnaryOperator::getOpcodeStr(Opc), OpLoc); 5934 return ExprError(); 5935 5936 case OR_Deleted: 5937 Diag(OpLoc, diag::err_ovl_deleted_oper) 5938 << Best->Function->isDeleted() 5939 << UnaryOperator::getOpcodeStr(Opc) 5940 << Input->getSourceRange(); 5941 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 5942 return ExprError(); 5943 } 5944 5945 // Either we found no viable overloaded operator or we matched a 5946 // built-in operator. In either case, fall through to trying to 5947 // build a built-in operation. 5948 input.release(); 5949 return CreateBuiltinUnaryOp(OpLoc, Opc, Owned(Input)); 5950} 5951 5952/// \brief Create a binary operation that may resolve to an overloaded 5953/// operator. 5954/// 5955/// \param OpLoc The location of the operator itself (e.g., '+'). 5956/// 5957/// \param OpcIn The BinaryOperator::Opcode that describes this 5958/// operator. 5959/// 5960/// \param Functions The set of non-member functions that will be 5961/// considered by overload resolution. The caller needs to build this 5962/// set based on the context using, e.g., 5963/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 5964/// set should not contain any member functions; those will be added 5965/// by CreateOverloadedBinOp(). 5966/// 5967/// \param LHS Left-hand argument. 5968/// \param RHS Right-hand argument. 5969Sema::OwningExprResult 5970Sema::CreateOverloadedBinOp(SourceLocation OpLoc, 5971 unsigned OpcIn, 5972 const UnresolvedSetImpl &Fns, 5973 Expr *LHS, Expr *RHS) { 5974 Expr *Args[2] = { LHS, RHS }; 5975 LHS=RHS=0; //Please use only Args instead of LHS/RHS couple 5976 5977 BinaryOperator::Opcode Opc = static_cast<BinaryOperator::Opcode>(OpcIn); 5978 OverloadedOperatorKind Op = BinaryOperator::getOverloadedOperator(Opc); 5979 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 5980 5981 // If either side is type-dependent, create an appropriate dependent 5982 // expression. 5983 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 5984 if (Fns.empty()) { 5985 // If there are no functions to store, just build a dependent 5986 // BinaryOperator or CompoundAssignment. 5987 if (Opc <= BinaryOperator::Assign || Opc > BinaryOperator::OrAssign) 5988 return Owned(new (Context) BinaryOperator(Args[0], Args[1], Opc, 5989 Context.DependentTy, OpLoc)); 5990 5991 return Owned(new (Context) CompoundAssignOperator(Args[0], Args[1], Opc, 5992 Context.DependentTy, 5993 Context.DependentTy, 5994 Context.DependentTy, 5995 OpLoc)); 5996 } 5997 5998 // FIXME: save results of ADL from here? 5999 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 6000 UnresolvedLookupExpr *Fn 6001 = UnresolvedLookupExpr::Create(Context, /*Dependent*/ true, NamingClass, 6002 0, SourceRange(), OpName, OpLoc, 6003 /*ADL*/ true, IsOverloaded(Fns)); 6004 6005 Fn->addDecls(Fns.begin(), Fns.end()); 6006 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 6007 Args, 2, 6008 Context.DependentTy, 6009 OpLoc)); 6010 } 6011 6012 // If this is the .* operator, which is not overloadable, just 6013 // create a built-in binary operator. 6014 if (Opc == BinaryOperator::PtrMemD) 6015 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 6016 6017 // If this is the assignment operator, we only perform overload resolution 6018 // if the left-hand side is a class or enumeration type. This is actually 6019 // a hack. The standard requires that we do overload resolution between the 6020 // various built-in candidates, but as DR507 points out, this can lead to 6021 // problems. So we do it this way, which pretty much follows what GCC does. 6022 // Note that we go the traditional code path for compound assignment forms. 6023 if (Opc==BinaryOperator::Assign && !Args[0]->getType()->isOverloadableType()) 6024 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 6025 6026 // Build an empty overload set. 6027 OverloadCandidateSet CandidateSet(OpLoc); 6028 6029 // Add the candidates from the given function set. 6030 AddFunctionCandidates(Fns, Args, 2, CandidateSet, false); 6031 6032 // Add operator candidates that are member functions. 6033 AddMemberOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 6034 6035 // Add candidates from ADL. 6036 AddArgumentDependentLookupCandidates(OpName, /*Operator*/ true, 6037 Args, 2, 6038 /*ExplicitTemplateArgs*/ 0, 6039 CandidateSet); 6040 6041 // Add builtin operator candidates. 6042 AddBuiltinOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 6043 6044 // Perform overload resolution. 6045 OverloadCandidateSet::iterator Best; 6046 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 6047 case OR_Success: { 6048 // We found a built-in operator or an overloaded operator. 6049 FunctionDecl *FnDecl = Best->Function; 6050 6051 if (FnDecl) { 6052 // We matched an overloaded operator. Build a call to that 6053 // operator. 6054 6055 // Convert the arguments. 6056 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 6057 // Best->Access is only meaningful for class members. 6058 CheckMemberOperatorAccess(OpLoc, Args[0], Args[1], Best->FoundDecl); 6059 6060 OwningExprResult Arg1 6061 = PerformCopyInitialization( 6062 InitializedEntity::InitializeParameter( 6063 FnDecl->getParamDecl(0)), 6064 SourceLocation(), 6065 Owned(Args[1])); 6066 if (Arg1.isInvalid()) 6067 return ExprError(); 6068 6069 if (PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/0, 6070 Best->FoundDecl, Method)) 6071 return ExprError(); 6072 6073 Args[1] = RHS = Arg1.takeAs<Expr>(); 6074 } else { 6075 // Convert the arguments. 6076 OwningExprResult Arg0 6077 = PerformCopyInitialization( 6078 InitializedEntity::InitializeParameter( 6079 FnDecl->getParamDecl(0)), 6080 SourceLocation(), 6081 Owned(Args[0])); 6082 if (Arg0.isInvalid()) 6083 return ExprError(); 6084 6085 OwningExprResult Arg1 6086 = PerformCopyInitialization( 6087 InitializedEntity::InitializeParameter( 6088 FnDecl->getParamDecl(1)), 6089 SourceLocation(), 6090 Owned(Args[1])); 6091 if (Arg1.isInvalid()) 6092 return ExprError(); 6093 Args[0] = LHS = Arg0.takeAs<Expr>(); 6094 Args[1] = RHS = Arg1.takeAs<Expr>(); 6095 } 6096 6097 // Determine the result type 6098 QualType ResultTy 6099 = FnDecl->getType()->getAs<FunctionType>()->getResultType(); 6100 ResultTy = ResultTy.getNonReferenceType(); 6101 6102 // Build the actual expression node. 6103 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 6104 OpLoc); 6105 UsualUnaryConversions(FnExpr); 6106 6107 ExprOwningPtr<CXXOperatorCallExpr> 6108 TheCall(this, new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 6109 Args, 2, ResultTy, 6110 OpLoc)); 6111 6112 if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall.get(), 6113 FnDecl)) 6114 return ExprError(); 6115 6116 return MaybeBindToTemporary(TheCall.release()); 6117 } else { 6118 // We matched a built-in operator. Convert the arguments, then 6119 // break out so that we will build the appropriate built-in 6120 // operator node. 6121 if (PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 6122 Best->Conversions[0], AA_Passing) || 6123 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 6124 Best->Conversions[1], AA_Passing)) 6125 return ExprError(); 6126 6127 break; 6128 } 6129 } 6130 6131 case OR_No_Viable_Function: { 6132 // C++ [over.match.oper]p9: 6133 // If the operator is the operator , [...] and there are no 6134 // viable functions, then the operator is assumed to be the 6135 // built-in operator and interpreted according to clause 5. 6136 if (Opc == BinaryOperator::Comma) 6137 break; 6138 6139 // For class as left operand for assignment or compound assigment operator 6140 // do not fall through to handling in built-in, but report that no overloaded 6141 // assignment operator found 6142 OwningExprResult Result = ExprError(); 6143 if (Args[0]->getType()->isRecordType() && 6144 Opc >= BinaryOperator::Assign && Opc <= BinaryOperator::OrAssign) { 6145 Diag(OpLoc, diag::err_ovl_no_viable_oper) 6146 << BinaryOperator::getOpcodeStr(Opc) 6147 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 6148 } else { 6149 // No viable function; try to create a built-in operation, which will 6150 // produce an error. Then, show the non-viable candidates. 6151 Result = CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 6152 } 6153 assert(Result.isInvalid() && 6154 "C++ binary operator overloading is missing candidates!"); 6155 if (Result.isInvalid()) 6156 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2, 6157 BinaryOperator::getOpcodeStr(Opc), OpLoc); 6158 return move(Result); 6159 } 6160 6161 case OR_Ambiguous: 6162 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 6163 << BinaryOperator::getOpcodeStr(Opc) 6164 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 6165 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, 2, 6166 BinaryOperator::getOpcodeStr(Opc), OpLoc); 6167 return ExprError(); 6168 6169 case OR_Deleted: 6170 Diag(OpLoc, diag::err_ovl_deleted_oper) 6171 << Best->Function->isDeleted() 6172 << BinaryOperator::getOpcodeStr(Opc) 6173 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 6174 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2); 6175 return ExprError(); 6176 } 6177 6178 // We matched a built-in operator; build it. 6179 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 6180} 6181 6182Action::OwningExprResult 6183Sema::CreateOverloadedArraySubscriptExpr(SourceLocation LLoc, 6184 SourceLocation RLoc, 6185 ExprArg Base, ExprArg Idx) { 6186 Expr *Args[2] = { static_cast<Expr*>(Base.get()), 6187 static_cast<Expr*>(Idx.get()) }; 6188 DeclarationName OpName = 6189 Context.DeclarationNames.getCXXOperatorName(OO_Subscript); 6190 6191 // If either side is type-dependent, create an appropriate dependent 6192 // expression. 6193 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 6194 6195 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 6196 UnresolvedLookupExpr *Fn 6197 = UnresolvedLookupExpr::Create(Context, /*Dependent*/ true, NamingClass, 6198 0, SourceRange(), OpName, LLoc, 6199 /*ADL*/ true, /*Overloaded*/ false); 6200 // Can't add any actual overloads yet 6201 6202 Base.release(); 6203 Idx.release(); 6204 return Owned(new (Context) CXXOperatorCallExpr(Context, OO_Subscript, Fn, 6205 Args, 2, 6206 Context.DependentTy, 6207 RLoc)); 6208 } 6209 6210 // Build an empty overload set. 6211 OverloadCandidateSet CandidateSet(LLoc); 6212 6213 // Subscript can only be overloaded as a member function. 6214 6215 // Add operator candidates that are member functions. 6216 AddMemberOperatorCandidates(OO_Subscript, LLoc, Args, 2, CandidateSet); 6217 6218 // Add builtin operator candidates. 6219 AddBuiltinOperatorCandidates(OO_Subscript, LLoc, Args, 2, CandidateSet); 6220 6221 // Perform overload resolution. 6222 OverloadCandidateSet::iterator Best; 6223 switch (BestViableFunction(CandidateSet, LLoc, Best)) { 6224 case OR_Success: { 6225 // We found a built-in operator or an overloaded operator. 6226 FunctionDecl *FnDecl = Best->Function; 6227 6228 if (FnDecl) { 6229 // We matched an overloaded operator. Build a call to that 6230 // operator. 6231 6232 CheckMemberOperatorAccess(LLoc, Args[0], Args[1], Best->FoundDecl); 6233 6234 // Convert the arguments. 6235 CXXMethodDecl *Method = cast<CXXMethodDecl>(FnDecl); 6236 if (PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/0, 6237 Best->FoundDecl, Method)) 6238 return ExprError(); 6239 6240 // Convert the arguments. 6241 OwningExprResult InputInit 6242 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 6243 FnDecl->getParamDecl(0)), 6244 SourceLocation(), 6245 Owned(Args[1])); 6246 if (InputInit.isInvalid()) 6247 return ExprError(); 6248 6249 Args[1] = InputInit.takeAs<Expr>(); 6250 6251 // Determine the result type 6252 QualType ResultTy 6253 = FnDecl->getType()->getAs<FunctionType>()->getResultType(); 6254 ResultTy = ResultTy.getNonReferenceType(); 6255 6256 // Build the actual expression node. 6257 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 6258 LLoc); 6259 UsualUnaryConversions(FnExpr); 6260 6261 Base.release(); 6262 Idx.release(); 6263 ExprOwningPtr<CXXOperatorCallExpr> 6264 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Subscript, 6265 FnExpr, Args, 2, 6266 ResultTy, RLoc)); 6267 6268 if (CheckCallReturnType(FnDecl->getResultType(), LLoc, TheCall.get(), 6269 FnDecl)) 6270 return ExprError(); 6271 6272 return MaybeBindToTemporary(TheCall.release()); 6273 } else { 6274 // We matched a built-in operator. Convert the arguments, then 6275 // break out so that we will build the appropriate built-in 6276 // operator node. 6277 if (PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 6278 Best->Conversions[0], AA_Passing) || 6279 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 6280 Best->Conversions[1], AA_Passing)) 6281 return ExprError(); 6282 6283 break; 6284 } 6285 } 6286 6287 case OR_No_Viable_Function: { 6288 if (CandidateSet.empty()) 6289 Diag(LLoc, diag::err_ovl_no_oper) 6290 << Args[0]->getType() << /*subscript*/ 0 6291 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 6292 else 6293 Diag(LLoc, diag::err_ovl_no_viable_subscript) 6294 << Args[0]->getType() 6295 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 6296 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2, 6297 "[]", LLoc); 6298 return ExprError(); 6299 } 6300 6301 case OR_Ambiguous: 6302 Diag(LLoc, diag::err_ovl_ambiguous_oper) 6303 << "[]" << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 6304 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, 2, 6305 "[]", LLoc); 6306 return ExprError(); 6307 6308 case OR_Deleted: 6309 Diag(LLoc, diag::err_ovl_deleted_oper) 6310 << Best->Function->isDeleted() << "[]" 6311 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 6312 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2, 6313 "[]", LLoc); 6314 return ExprError(); 6315 } 6316 6317 // We matched a built-in operator; build it. 6318 Base.release(); 6319 Idx.release(); 6320 return CreateBuiltinArraySubscriptExpr(Owned(Args[0]), LLoc, 6321 Owned(Args[1]), RLoc); 6322} 6323 6324/// BuildCallToMemberFunction - Build a call to a member 6325/// function. MemExpr is the expression that refers to the member 6326/// function (and includes the object parameter), Args/NumArgs are the 6327/// arguments to the function call (not including the object 6328/// parameter). The caller needs to validate that the member 6329/// expression refers to a member function or an overloaded member 6330/// function. 6331Sema::OwningExprResult 6332Sema::BuildCallToMemberFunction(Scope *S, Expr *MemExprE, 6333 SourceLocation LParenLoc, Expr **Args, 6334 unsigned NumArgs, SourceLocation *CommaLocs, 6335 SourceLocation RParenLoc) { 6336 // Dig out the member expression. This holds both the object 6337 // argument and the member function we're referring to. 6338 Expr *NakedMemExpr = MemExprE->IgnoreParens(); 6339 6340 MemberExpr *MemExpr; 6341 CXXMethodDecl *Method = 0; 6342 DeclAccessPair FoundDecl = DeclAccessPair::make(0, AS_public); 6343 NestedNameSpecifier *Qualifier = 0; 6344 if (isa<MemberExpr>(NakedMemExpr)) { 6345 MemExpr = cast<MemberExpr>(NakedMemExpr); 6346 Method = cast<CXXMethodDecl>(MemExpr->getMemberDecl()); 6347 FoundDecl = MemExpr->getFoundDecl(); 6348 Qualifier = MemExpr->getQualifier(); 6349 } else { 6350 UnresolvedMemberExpr *UnresExpr = cast<UnresolvedMemberExpr>(NakedMemExpr); 6351 Qualifier = UnresExpr->getQualifier(); 6352 6353 QualType ObjectType = UnresExpr->getBaseType(); 6354 6355 // Add overload candidates 6356 OverloadCandidateSet CandidateSet(UnresExpr->getMemberLoc()); 6357 6358 // FIXME: avoid copy. 6359 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 6360 if (UnresExpr->hasExplicitTemplateArgs()) { 6361 UnresExpr->copyTemplateArgumentsInto(TemplateArgsBuffer); 6362 TemplateArgs = &TemplateArgsBuffer; 6363 } 6364 6365 for (UnresolvedMemberExpr::decls_iterator I = UnresExpr->decls_begin(), 6366 E = UnresExpr->decls_end(); I != E; ++I) { 6367 6368 NamedDecl *Func = *I; 6369 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(Func->getDeclContext()); 6370 if (isa<UsingShadowDecl>(Func)) 6371 Func = cast<UsingShadowDecl>(Func)->getTargetDecl(); 6372 6373 if ((Method = dyn_cast<CXXMethodDecl>(Func))) { 6374 // If explicit template arguments were provided, we can't call a 6375 // non-template member function. 6376 if (TemplateArgs) 6377 continue; 6378 6379 AddMethodCandidate(Method, I.getPair(), ActingDC, ObjectType, 6380 Args, NumArgs, 6381 CandidateSet, /*SuppressUserConversions=*/false); 6382 } else { 6383 AddMethodTemplateCandidate(cast<FunctionTemplateDecl>(Func), 6384 I.getPair(), ActingDC, TemplateArgs, 6385 ObjectType, Args, NumArgs, 6386 CandidateSet, 6387 /*SuppressUsedConversions=*/false); 6388 } 6389 } 6390 6391 DeclarationName DeclName = UnresExpr->getMemberName(); 6392 6393 OverloadCandidateSet::iterator Best; 6394 switch (BestViableFunction(CandidateSet, UnresExpr->getLocStart(), Best)) { 6395 case OR_Success: 6396 Method = cast<CXXMethodDecl>(Best->Function); 6397 FoundDecl = Best->FoundDecl; 6398 CheckUnresolvedMemberAccess(UnresExpr, Best->FoundDecl); 6399 break; 6400 6401 case OR_No_Viable_Function: 6402 Diag(UnresExpr->getMemberLoc(), 6403 diag::err_ovl_no_viable_member_function_in_call) 6404 << DeclName << MemExprE->getSourceRange(); 6405 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6406 // FIXME: Leaking incoming expressions! 6407 return ExprError(); 6408 6409 case OR_Ambiguous: 6410 Diag(UnresExpr->getMemberLoc(), diag::err_ovl_ambiguous_member_call) 6411 << DeclName << MemExprE->getSourceRange(); 6412 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6413 // FIXME: Leaking incoming expressions! 6414 return ExprError(); 6415 6416 case OR_Deleted: 6417 Diag(UnresExpr->getMemberLoc(), diag::err_ovl_deleted_member_call) 6418 << Best->Function->isDeleted() 6419 << DeclName << MemExprE->getSourceRange(); 6420 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6421 // FIXME: Leaking incoming expressions! 6422 return ExprError(); 6423 } 6424 6425 MemExprE = FixOverloadedFunctionReference(MemExprE, FoundDecl, Method); 6426 6427 // If overload resolution picked a static member, build a 6428 // non-member call based on that function. 6429 if (Method->isStatic()) { 6430 return BuildResolvedCallExpr(MemExprE, Method, LParenLoc, 6431 Args, NumArgs, RParenLoc); 6432 } 6433 6434 MemExpr = cast<MemberExpr>(MemExprE->IgnoreParens()); 6435 } 6436 6437 assert(Method && "Member call to something that isn't a method?"); 6438 ExprOwningPtr<CXXMemberCallExpr> 6439 TheCall(this, new (Context) CXXMemberCallExpr(Context, MemExprE, Args, 6440 NumArgs, 6441 Method->getResultType().getNonReferenceType(), 6442 RParenLoc)); 6443 6444 // Check for a valid return type. 6445 if (CheckCallReturnType(Method->getResultType(), MemExpr->getMemberLoc(), 6446 TheCall.get(), Method)) 6447 return ExprError(); 6448 6449 // Convert the object argument (for a non-static member function call). 6450 // We only need to do this if there was actually an overload; otherwise 6451 // it was done at lookup. 6452 Expr *ObjectArg = MemExpr->getBase(); 6453 if (!Method->isStatic() && 6454 PerformObjectArgumentInitialization(ObjectArg, Qualifier, 6455 FoundDecl, Method)) 6456 return ExprError(); 6457 MemExpr->setBase(ObjectArg); 6458 6459 // Convert the rest of the arguments 6460 const FunctionProtoType *Proto = cast<FunctionProtoType>(Method->getType()); 6461 if (ConvertArgumentsForCall(&*TheCall, MemExpr, Method, Proto, Args, NumArgs, 6462 RParenLoc)) 6463 return ExprError(); 6464 6465 if (CheckFunctionCall(Method, TheCall.get())) 6466 return ExprError(); 6467 6468 return MaybeBindToTemporary(TheCall.release()); 6469} 6470 6471/// BuildCallToObjectOfClassType - Build a call to an object of class 6472/// type (C++ [over.call.object]), which can end up invoking an 6473/// overloaded function call operator (@c operator()) or performing a 6474/// user-defined conversion on the object argument. 6475Sema::ExprResult 6476Sema::BuildCallToObjectOfClassType(Scope *S, Expr *Object, 6477 SourceLocation LParenLoc, 6478 Expr **Args, unsigned NumArgs, 6479 SourceLocation *CommaLocs, 6480 SourceLocation RParenLoc) { 6481 assert(Object->getType()->isRecordType() && "Requires object type argument"); 6482 const RecordType *Record = Object->getType()->getAs<RecordType>(); 6483 6484 // C++ [over.call.object]p1: 6485 // If the primary-expression E in the function call syntax 6486 // evaluates to a class object of type "cv T", then the set of 6487 // candidate functions includes at least the function call 6488 // operators of T. The function call operators of T are obtained by 6489 // ordinary lookup of the name operator() in the context of 6490 // (E).operator(). 6491 OverloadCandidateSet CandidateSet(LParenLoc); 6492 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Call); 6493 6494 if (RequireCompleteType(LParenLoc, Object->getType(), 6495 PDiag(diag::err_incomplete_object_call) 6496 << Object->getSourceRange())) 6497 return true; 6498 6499 LookupResult R(*this, OpName, LParenLoc, LookupOrdinaryName); 6500 LookupQualifiedName(R, Record->getDecl()); 6501 R.suppressDiagnostics(); 6502 6503 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 6504 Oper != OperEnd; ++Oper) { 6505 AddMethodCandidate(Oper.getPair(), Object->getType(), 6506 Args, NumArgs, CandidateSet, 6507 /*SuppressUserConversions=*/ false); 6508 } 6509 6510 // C++ [over.call.object]p2: 6511 // In addition, for each conversion function declared in T of the 6512 // form 6513 // 6514 // operator conversion-type-id () cv-qualifier; 6515 // 6516 // where cv-qualifier is the same cv-qualification as, or a 6517 // greater cv-qualification than, cv, and where conversion-type-id 6518 // denotes the type "pointer to function of (P1,...,Pn) returning 6519 // R", or the type "reference to pointer to function of 6520 // (P1,...,Pn) returning R", or the type "reference to function 6521 // of (P1,...,Pn) returning R", a surrogate call function [...] 6522 // is also considered as a candidate function. Similarly, 6523 // surrogate call functions are added to the set of candidate 6524 // functions for each conversion function declared in an 6525 // accessible base class provided the function is not hidden 6526 // within T by another intervening declaration. 6527 const UnresolvedSetImpl *Conversions 6528 = cast<CXXRecordDecl>(Record->getDecl())->getVisibleConversionFunctions(); 6529 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 6530 E = Conversions->end(); I != E; ++I) { 6531 NamedDecl *D = *I; 6532 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext()); 6533 if (isa<UsingShadowDecl>(D)) 6534 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 6535 6536 // Skip over templated conversion functions; they aren't 6537 // surrogates. 6538 if (isa<FunctionTemplateDecl>(D)) 6539 continue; 6540 6541 CXXConversionDecl *Conv = cast<CXXConversionDecl>(D); 6542 6543 // Strip the reference type (if any) and then the pointer type (if 6544 // any) to get down to what might be a function type. 6545 QualType ConvType = Conv->getConversionType().getNonReferenceType(); 6546 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 6547 ConvType = ConvPtrType->getPointeeType(); 6548 6549 if (const FunctionProtoType *Proto = ConvType->getAs<FunctionProtoType>()) 6550 AddSurrogateCandidate(Conv, I.getPair(), ActingContext, Proto, 6551 Object->getType(), Args, NumArgs, 6552 CandidateSet); 6553 } 6554 6555 // Perform overload resolution. 6556 OverloadCandidateSet::iterator Best; 6557 switch (BestViableFunction(CandidateSet, Object->getLocStart(), Best)) { 6558 case OR_Success: 6559 // Overload resolution succeeded; we'll build the appropriate call 6560 // below. 6561 break; 6562 6563 case OR_No_Viable_Function: 6564 if (CandidateSet.empty()) 6565 Diag(Object->getSourceRange().getBegin(), diag::err_ovl_no_oper) 6566 << Object->getType() << /*call*/ 1 6567 << Object->getSourceRange(); 6568 else 6569 Diag(Object->getSourceRange().getBegin(), 6570 diag::err_ovl_no_viable_object_call) 6571 << Object->getType() << Object->getSourceRange(); 6572 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6573 break; 6574 6575 case OR_Ambiguous: 6576 Diag(Object->getSourceRange().getBegin(), 6577 diag::err_ovl_ambiguous_object_call) 6578 << Object->getType() << Object->getSourceRange(); 6579 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, NumArgs); 6580 break; 6581 6582 case OR_Deleted: 6583 Diag(Object->getSourceRange().getBegin(), 6584 diag::err_ovl_deleted_object_call) 6585 << Best->Function->isDeleted() 6586 << Object->getType() << Object->getSourceRange(); 6587 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6588 break; 6589 } 6590 6591 if (Best == CandidateSet.end()) { 6592 // We had an error; delete all of the subexpressions and return 6593 // the error. 6594 Object->Destroy(Context); 6595 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 6596 Args[ArgIdx]->Destroy(Context); 6597 return true; 6598 } 6599 6600 if (Best->Function == 0) { 6601 // Since there is no function declaration, this is one of the 6602 // surrogate candidates. Dig out the conversion function. 6603 CXXConversionDecl *Conv 6604 = cast<CXXConversionDecl>( 6605 Best->Conversions[0].UserDefined.ConversionFunction); 6606 6607 CheckMemberOperatorAccess(LParenLoc, Object, 0, Best->FoundDecl); 6608 6609 // We selected one of the surrogate functions that converts the 6610 // object parameter to a function pointer. Perform the conversion 6611 // on the object argument, then let ActOnCallExpr finish the job. 6612 6613 // Create an implicit member expr to refer to the conversion operator. 6614 // and then call it. 6615 CXXMemberCallExpr *CE = BuildCXXMemberCallExpr(Object, Best->FoundDecl, 6616 Conv); 6617 6618 return ActOnCallExpr(S, ExprArg(*this, CE), LParenLoc, 6619 MultiExprArg(*this, (ExprTy**)Args, NumArgs), 6620 CommaLocs, RParenLoc).result(); 6621 } 6622 6623 CheckMemberOperatorAccess(LParenLoc, Object, 0, Best->FoundDecl); 6624 6625 // We found an overloaded operator(). Build a CXXOperatorCallExpr 6626 // that calls this method, using Object for the implicit object 6627 // parameter and passing along the remaining arguments. 6628 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 6629 const FunctionProtoType *Proto = Method->getType()->getAs<FunctionProtoType>(); 6630 6631 unsigned NumArgsInProto = Proto->getNumArgs(); 6632 unsigned NumArgsToCheck = NumArgs; 6633 6634 // Build the full argument list for the method call (the 6635 // implicit object parameter is placed at the beginning of the 6636 // list). 6637 Expr **MethodArgs; 6638 if (NumArgs < NumArgsInProto) { 6639 NumArgsToCheck = NumArgsInProto; 6640 MethodArgs = new Expr*[NumArgsInProto + 1]; 6641 } else { 6642 MethodArgs = new Expr*[NumArgs + 1]; 6643 } 6644 MethodArgs[0] = Object; 6645 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 6646 MethodArgs[ArgIdx + 1] = Args[ArgIdx]; 6647 6648 Expr *NewFn = new (Context) DeclRefExpr(Method, Method->getType(), 6649 SourceLocation()); 6650 UsualUnaryConversions(NewFn); 6651 6652 // Once we've built TheCall, all of the expressions are properly 6653 // owned. 6654 QualType ResultTy = Method->getResultType().getNonReferenceType(); 6655 ExprOwningPtr<CXXOperatorCallExpr> 6656 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Call, NewFn, 6657 MethodArgs, NumArgs + 1, 6658 ResultTy, RParenLoc)); 6659 delete [] MethodArgs; 6660 6661 if (CheckCallReturnType(Method->getResultType(), LParenLoc, TheCall.get(), 6662 Method)) 6663 return true; 6664 6665 // We may have default arguments. If so, we need to allocate more 6666 // slots in the call for them. 6667 if (NumArgs < NumArgsInProto) 6668 TheCall->setNumArgs(Context, NumArgsInProto + 1); 6669 else if (NumArgs > NumArgsInProto) 6670 NumArgsToCheck = NumArgsInProto; 6671 6672 bool IsError = false; 6673 6674 // Initialize the implicit object parameter. 6675 IsError |= PerformObjectArgumentInitialization(Object, /*Qualifier=*/0, 6676 Best->FoundDecl, Method); 6677 TheCall->setArg(0, Object); 6678 6679 6680 // Check the argument types. 6681 for (unsigned i = 0; i != NumArgsToCheck; i++) { 6682 Expr *Arg; 6683 if (i < NumArgs) { 6684 Arg = Args[i]; 6685 6686 // Pass the argument. 6687 6688 OwningExprResult InputInit 6689 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 6690 Method->getParamDecl(i)), 6691 SourceLocation(), Owned(Arg)); 6692 6693 IsError |= InputInit.isInvalid(); 6694 Arg = InputInit.takeAs<Expr>(); 6695 } else { 6696 OwningExprResult DefArg 6697 = BuildCXXDefaultArgExpr(LParenLoc, Method, Method->getParamDecl(i)); 6698 if (DefArg.isInvalid()) { 6699 IsError = true; 6700 break; 6701 } 6702 6703 Arg = DefArg.takeAs<Expr>(); 6704 } 6705 6706 TheCall->setArg(i + 1, Arg); 6707 } 6708 6709 // If this is a variadic call, handle args passed through "...". 6710 if (Proto->isVariadic()) { 6711 // Promote the arguments (C99 6.5.2.2p7). 6712 for (unsigned i = NumArgsInProto; i != NumArgs; i++) { 6713 Expr *Arg = Args[i]; 6714 IsError |= DefaultVariadicArgumentPromotion(Arg, VariadicMethod); 6715 TheCall->setArg(i + 1, Arg); 6716 } 6717 } 6718 6719 if (IsError) return true; 6720 6721 if (CheckFunctionCall(Method, TheCall.get())) 6722 return true; 6723 6724 return MaybeBindToTemporary(TheCall.release()).result(); 6725} 6726 6727/// BuildOverloadedArrowExpr - Build a call to an overloaded @c operator-> 6728/// (if one exists), where @c Base is an expression of class type and 6729/// @c Member is the name of the member we're trying to find. 6730Sema::OwningExprResult 6731Sema::BuildOverloadedArrowExpr(Scope *S, ExprArg BaseIn, SourceLocation OpLoc) { 6732 Expr *Base = static_cast<Expr *>(BaseIn.get()); 6733 assert(Base->getType()->isRecordType() && "left-hand side must have class type"); 6734 6735 SourceLocation Loc = Base->getExprLoc(); 6736 6737 // C++ [over.ref]p1: 6738 // 6739 // [...] An expression x->m is interpreted as (x.operator->())->m 6740 // for a class object x of type T if T::operator->() exists and if 6741 // the operator is selected as the best match function by the 6742 // overload resolution mechanism (13.3). 6743 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Arrow); 6744 OverloadCandidateSet CandidateSet(Loc); 6745 const RecordType *BaseRecord = Base->getType()->getAs<RecordType>(); 6746 6747 if (RequireCompleteType(Loc, Base->getType(), 6748 PDiag(diag::err_typecheck_incomplete_tag) 6749 << Base->getSourceRange())) 6750 return ExprError(); 6751 6752 LookupResult R(*this, OpName, OpLoc, LookupOrdinaryName); 6753 LookupQualifiedName(R, BaseRecord->getDecl()); 6754 R.suppressDiagnostics(); 6755 6756 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 6757 Oper != OperEnd; ++Oper) { 6758 AddMethodCandidate(Oper.getPair(), Base->getType(), 0, 0, CandidateSet, 6759 /*SuppressUserConversions=*/false); 6760 } 6761 6762 // Perform overload resolution. 6763 OverloadCandidateSet::iterator Best; 6764 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 6765 case OR_Success: 6766 // Overload resolution succeeded; we'll build the call below. 6767 break; 6768 6769 case OR_No_Viable_Function: 6770 if (CandidateSet.empty()) 6771 Diag(OpLoc, diag::err_typecheck_member_reference_arrow) 6772 << Base->getType() << Base->getSourceRange(); 6773 else 6774 Diag(OpLoc, diag::err_ovl_no_viable_oper) 6775 << "operator->" << Base->getSourceRange(); 6776 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, &Base, 1); 6777 return ExprError(); 6778 6779 case OR_Ambiguous: 6780 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 6781 << "->" << Base->getSourceRange(); 6782 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, &Base, 1); 6783 return ExprError(); 6784 6785 case OR_Deleted: 6786 Diag(OpLoc, diag::err_ovl_deleted_oper) 6787 << Best->Function->isDeleted() 6788 << "->" << Base->getSourceRange(); 6789 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, &Base, 1); 6790 return ExprError(); 6791 } 6792 6793 CheckMemberOperatorAccess(OpLoc, Base, 0, Best->FoundDecl); 6794 6795 // Convert the object parameter. 6796 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 6797 if (PerformObjectArgumentInitialization(Base, /*Qualifier=*/0, 6798 Best->FoundDecl, Method)) 6799 return ExprError(); 6800 6801 // No concerns about early exits now. 6802 BaseIn.release(); 6803 6804 // Build the operator call. 6805 Expr *FnExpr = new (Context) DeclRefExpr(Method, Method->getType(), 6806 SourceLocation()); 6807 UsualUnaryConversions(FnExpr); 6808 6809 QualType ResultTy = Method->getResultType().getNonReferenceType(); 6810 ExprOwningPtr<CXXOperatorCallExpr> 6811 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Arrow, FnExpr, 6812 &Base, 1, ResultTy, OpLoc)); 6813 6814 if (CheckCallReturnType(Method->getResultType(), OpLoc, TheCall.get(), 6815 Method)) 6816 return ExprError(); 6817 return move(TheCall); 6818} 6819 6820/// FixOverloadedFunctionReference - E is an expression that refers to 6821/// a C++ overloaded function (possibly with some parentheses and 6822/// perhaps a '&' around it). We have resolved the overloaded function 6823/// to the function declaration Fn, so patch up the expression E to 6824/// refer (possibly indirectly) to Fn. Returns the new expr. 6825Expr *Sema::FixOverloadedFunctionReference(Expr *E, DeclAccessPair Found, 6826 FunctionDecl *Fn) { 6827 if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) { 6828 Expr *SubExpr = FixOverloadedFunctionReference(PE->getSubExpr(), 6829 Found, Fn); 6830 if (SubExpr == PE->getSubExpr()) 6831 return PE->Retain(); 6832 6833 return new (Context) ParenExpr(PE->getLParen(), PE->getRParen(), SubExpr); 6834 } 6835 6836 if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) { 6837 Expr *SubExpr = FixOverloadedFunctionReference(ICE->getSubExpr(), 6838 Found, Fn); 6839 assert(Context.hasSameType(ICE->getSubExpr()->getType(), 6840 SubExpr->getType()) && 6841 "Implicit cast type cannot be determined from overload"); 6842 if (SubExpr == ICE->getSubExpr()) 6843 return ICE->Retain(); 6844 6845 return new (Context) ImplicitCastExpr(ICE->getType(), 6846 ICE->getCastKind(), 6847 SubExpr, 6848 ICE->isLvalueCast()); 6849 } 6850 6851 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(E)) { 6852 assert(UnOp->getOpcode() == UnaryOperator::AddrOf && 6853 "Can only take the address of an overloaded function"); 6854 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 6855 if (Method->isStatic()) { 6856 // Do nothing: static member functions aren't any different 6857 // from non-member functions. 6858 } else { 6859 // Fix the sub expression, which really has to be an 6860 // UnresolvedLookupExpr holding an overloaded member function 6861 // or template. 6862 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(), 6863 Found, Fn); 6864 if (SubExpr == UnOp->getSubExpr()) 6865 return UnOp->Retain(); 6866 6867 assert(isa<DeclRefExpr>(SubExpr) 6868 && "fixed to something other than a decl ref"); 6869 assert(cast<DeclRefExpr>(SubExpr)->getQualifier() 6870 && "fixed to a member ref with no nested name qualifier"); 6871 6872 // We have taken the address of a pointer to member 6873 // function. Perform the computation here so that we get the 6874 // appropriate pointer to member type. 6875 QualType ClassType 6876 = Context.getTypeDeclType(cast<RecordDecl>(Method->getDeclContext())); 6877 QualType MemPtrType 6878 = Context.getMemberPointerType(Fn->getType(), ClassType.getTypePtr()); 6879 6880 return new (Context) UnaryOperator(SubExpr, UnaryOperator::AddrOf, 6881 MemPtrType, UnOp->getOperatorLoc()); 6882 } 6883 } 6884 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(), 6885 Found, Fn); 6886 if (SubExpr == UnOp->getSubExpr()) 6887 return UnOp->Retain(); 6888 6889 return new (Context) UnaryOperator(SubExpr, UnaryOperator::AddrOf, 6890 Context.getPointerType(SubExpr->getType()), 6891 UnOp->getOperatorLoc()); 6892 } 6893 6894 if (UnresolvedLookupExpr *ULE = dyn_cast<UnresolvedLookupExpr>(E)) { 6895 // FIXME: avoid copy. 6896 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 6897 if (ULE->hasExplicitTemplateArgs()) { 6898 ULE->copyTemplateArgumentsInto(TemplateArgsBuffer); 6899 TemplateArgs = &TemplateArgsBuffer; 6900 } 6901 6902 return DeclRefExpr::Create(Context, 6903 ULE->getQualifier(), 6904 ULE->getQualifierRange(), 6905 Fn, 6906 ULE->getNameLoc(), 6907 Fn->getType(), 6908 TemplateArgs); 6909 } 6910 6911 if (UnresolvedMemberExpr *MemExpr = dyn_cast<UnresolvedMemberExpr>(E)) { 6912 // FIXME: avoid copy. 6913 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 6914 if (MemExpr->hasExplicitTemplateArgs()) { 6915 MemExpr->copyTemplateArgumentsInto(TemplateArgsBuffer); 6916 TemplateArgs = &TemplateArgsBuffer; 6917 } 6918 6919 Expr *Base; 6920 6921 // If we're filling in 6922 if (MemExpr->isImplicitAccess()) { 6923 if (cast<CXXMethodDecl>(Fn)->isStatic()) { 6924 return DeclRefExpr::Create(Context, 6925 MemExpr->getQualifier(), 6926 MemExpr->getQualifierRange(), 6927 Fn, 6928 MemExpr->getMemberLoc(), 6929 Fn->getType(), 6930 TemplateArgs); 6931 } else { 6932 SourceLocation Loc = MemExpr->getMemberLoc(); 6933 if (MemExpr->getQualifier()) 6934 Loc = MemExpr->getQualifierRange().getBegin(); 6935 Base = new (Context) CXXThisExpr(Loc, 6936 MemExpr->getBaseType(), 6937 /*isImplicit=*/true); 6938 } 6939 } else 6940 Base = MemExpr->getBase()->Retain(); 6941 6942 return MemberExpr::Create(Context, Base, 6943 MemExpr->isArrow(), 6944 MemExpr->getQualifier(), 6945 MemExpr->getQualifierRange(), 6946 Fn, 6947 Found, 6948 MemExpr->getMemberLoc(), 6949 TemplateArgs, 6950 Fn->getType()); 6951 } 6952 6953 assert(false && "Invalid reference to overloaded function"); 6954 return E->Retain(); 6955} 6956 6957Sema::OwningExprResult Sema::FixOverloadedFunctionReference(OwningExprResult E, 6958 DeclAccessPair Found, 6959 FunctionDecl *Fn) { 6960 return Owned(FixOverloadedFunctionReference((Expr *)E.get(), Found, Fn)); 6961} 6962 6963} // end namespace clang 6964