SemaOverload.cpp revision 1aae80b173e22fa5d649f114eb6607efac350d79
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 ForceRValue, 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 (FunctionDecl *Fn 617 = ResolveAddressOfOverloadedFunction(From, ToType, false, 618 AccessPair)) { 619 // Address of overloaded function (C++ [over.over]). 620 SCS.First = ICK_Function_To_Pointer; 621 622 // We were able to resolve the address of the overloaded function, 623 // so we can convert to the type of that function. 624 FromType = Fn->getType(); 625 if (ToType->isLValueReferenceType()) 626 FromType = Context.getLValueReferenceType(FromType); 627 else if (ToType->isRValueReferenceType()) 628 FromType = Context.getRValueReferenceType(FromType); 629 else if (ToType->isMemberPointerType()) { 630 // Resolve address only succeeds if both sides are member pointers, 631 // but it doesn't have to be the same class. See DR 247. 632 // Note that this means that the type of &Derived::fn can be 633 // Ret (Base::*)(Args) if the fn overload actually found is from the 634 // base class, even if it was brought into the derived class via a 635 // using declaration. The standard isn't clear on this issue at all. 636 CXXMethodDecl *M = cast<CXXMethodDecl>(Fn); 637 FromType = Context.getMemberPointerType(FromType, 638 Context.getTypeDeclType(M->getParent()).getTypePtr()); 639 } else 640 FromType = Context.getPointerType(FromType); 641 } else { 642 // We don't require any conversions for the first step. 643 SCS.First = ICK_Identity; 644 } 645 SCS.setToType(0, FromType); 646 647 // The second conversion can be an integral promotion, floating 648 // point promotion, integral conversion, floating point conversion, 649 // floating-integral conversion, pointer conversion, 650 // pointer-to-member conversion, or boolean conversion (C++ 4p1). 651 // For overloading in C, this can also be a "compatible-type" 652 // conversion. 653 bool IncompatibleObjC = false; 654 if (Context.hasSameUnqualifiedType(FromType, ToType)) { 655 // The unqualified versions of the types are the same: there's no 656 // conversion to do. 657 SCS.Second = ICK_Identity; 658 } else if (IsIntegralPromotion(From, FromType, ToType)) { 659 // Integral promotion (C++ 4.5). 660 SCS.Second = ICK_Integral_Promotion; 661 FromType = ToType.getUnqualifiedType(); 662 } else if (IsFloatingPointPromotion(FromType, ToType)) { 663 // Floating point promotion (C++ 4.6). 664 SCS.Second = ICK_Floating_Promotion; 665 FromType = ToType.getUnqualifiedType(); 666 } else if (IsComplexPromotion(FromType, ToType)) { 667 // Complex promotion (Clang extension) 668 SCS.Second = ICK_Complex_Promotion; 669 FromType = ToType.getUnqualifiedType(); 670 } else if ((FromType->isIntegralType() || FromType->isEnumeralType()) && 671 (ToType->isIntegralType() && !ToType->isEnumeralType())) { 672 // Integral conversions (C++ 4.7). 673 SCS.Second = ICK_Integral_Conversion; 674 FromType = ToType.getUnqualifiedType(); 675 } else if (FromType->isComplexType() && ToType->isComplexType()) { 676 // Complex conversions (C99 6.3.1.6) 677 SCS.Second = ICK_Complex_Conversion; 678 FromType = ToType.getUnqualifiedType(); 679 } else if ((FromType->isComplexType() && ToType->isArithmeticType()) || 680 (ToType->isComplexType() && FromType->isArithmeticType())) { 681 // Complex-real conversions (C99 6.3.1.7) 682 SCS.Second = ICK_Complex_Real; 683 FromType = ToType.getUnqualifiedType(); 684 } else if (FromType->isFloatingType() && ToType->isFloatingType()) { 685 // Floating point conversions (C++ 4.8). 686 SCS.Second = ICK_Floating_Conversion; 687 FromType = ToType.getUnqualifiedType(); 688 } else if ((FromType->isFloatingType() && 689 ToType->isIntegralType() && (!ToType->isBooleanType() && 690 !ToType->isEnumeralType())) || 691 ((FromType->isIntegralType() || FromType->isEnumeralType()) && 692 ToType->isFloatingType())) { 693 // Floating-integral conversions (C++ 4.9). 694 SCS.Second = ICK_Floating_Integral; 695 FromType = ToType.getUnqualifiedType(); 696 } else if (IsPointerConversion(From, FromType, ToType, InOverloadResolution, 697 FromType, IncompatibleObjC)) { 698 // Pointer conversions (C++ 4.10). 699 SCS.Second = ICK_Pointer_Conversion; 700 SCS.IncompatibleObjC = IncompatibleObjC; 701 } else if (IsMemberPointerConversion(From, FromType, ToType, 702 InOverloadResolution, FromType)) { 703 // Pointer to member conversions (4.11). 704 SCS.Second = ICK_Pointer_Member; 705 } else if (ToType->isBooleanType() && 706 (FromType->isArithmeticType() || 707 FromType->isEnumeralType() || 708 FromType->isAnyPointerType() || 709 FromType->isBlockPointerType() || 710 FromType->isMemberPointerType() || 711 FromType->isNullPtrType())) { 712 // Boolean conversions (C++ 4.12). 713 SCS.Second = ICK_Boolean_Conversion; 714 FromType = Context.BoolTy; 715 } else if (!getLangOptions().CPlusPlus && 716 Context.typesAreCompatible(ToType, FromType)) { 717 // Compatible conversions (Clang extension for C function overloading) 718 SCS.Second = ICK_Compatible_Conversion; 719 } else if (IsNoReturnConversion(Context, FromType, ToType, FromType)) { 720 // Treat a conversion that strips "noreturn" as an identity conversion. 721 SCS.Second = ICK_NoReturn_Adjustment; 722 } else { 723 // No second conversion required. 724 SCS.Second = ICK_Identity; 725 } 726 SCS.setToType(1, FromType); 727 728 QualType CanonFrom; 729 QualType CanonTo; 730 // The third conversion can be a qualification conversion (C++ 4p1). 731 if (IsQualificationConversion(FromType, ToType)) { 732 SCS.Third = ICK_Qualification; 733 FromType = ToType; 734 CanonFrom = Context.getCanonicalType(FromType); 735 CanonTo = Context.getCanonicalType(ToType); 736 } else { 737 // No conversion required 738 SCS.Third = ICK_Identity; 739 740 // C++ [over.best.ics]p6: 741 // [...] Any difference in top-level cv-qualification is 742 // subsumed by the initialization itself and does not constitute 743 // a conversion. [...] 744 CanonFrom = Context.getCanonicalType(FromType); 745 CanonTo = Context.getCanonicalType(ToType); 746 if (CanonFrom.getLocalUnqualifiedType() 747 == CanonTo.getLocalUnqualifiedType() && 748 CanonFrom.getLocalCVRQualifiers() != CanonTo.getLocalCVRQualifiers()) { 749 FromType = ToType; 750 CanonFrom = CanonTo; 751 } 752 } 753 SCS.setToType(2, FromType); 754 755 // If we have not converted the argument type to the parameter type, 756 // this is a bad conversion sequence. 757 if (CanonFrom != CanonTo) 758 return false; 759 760 return true; 761} 762 763/// IsIntegralPromotion - Determines whether the conversion from the 764/// expression From (whose potentially-adjusted type is FromType) to 765/// ToType is an integral promotion (C++ 4.5). If so, returns true and 766/// sets PromotedType to the promoted type. 767bool Sema::IsIntegralPromotion(Expr *From, QualType FromType, QualType ToType) { 768 const BuiltinType *To = ToType->getAs<BuiltinType>(); 769 // All integers are built-in. 770 if (!To) { 771 return false; 772 } 773 774 // An rvalue of type char, signed char, unsigned char, short int, or 775 // unsigned short int can be converted to an rvalue of type int if 776 // int can represent all the values of the source type; otherwise, 777 // the source rvalue can be converted to an rvalue of type unsigned 778 // int (C++ 4.5p1). 779 if (FromType->isPromotableIntegerType() && !FromType->isBooleanType() && 780 !FromType->isEnumeralType()) { 781 if (// We can promote any signed, promotable integer type to an int 782 (FromType->isSignedIntegerType() || 783 // We can promote any unsigned integer type whose size is 784 // less than int to an int. 785 (!FromType->isSignedIntegerType() && 786 Context.getTypeSize(FromType) < Context.getTypeSize(ToType)))) { 787 return To->getKind() == BuiltinType::Int; 788 } 789 790 return To->getKind() == BuiltinType::UInt; 791 } 792 793 // An rvalue of type wchar_t (3.9.1) or an enumeration type (7.2) 794 // can be converted to an rvalue of the first of the following types 795 // that can represent all the values of its underlying type: int, 796 // unsigned int, long, or unsigned long (C++ 4.5p2). 797 798 // We pre-calculate the promotion type for enum types. 799 if (const EnumType *FromEnumType = FromType->getAs<EnumType>()) 800 if (ToType->isIntegerType()) 801 return Context.hasSameUnqualifiedType(ToType, 802 FromEnumType->getDecl()->getPromotionType()); 803 804 if (FromType->isWideCharType() && ToType->isIntegerType()) { 805 // Determine whether the type we're converting from is signed or 806 // unsigned. 807 bool FromIsSigned; 808 uint64_t FromSize = Context.getTypeSize(FromType); 809 810 // FIXME: Is wchar_t signed or unsigned? We assume it's signed for now. 811 FromIsSigned = true; 812 813 // The types we'll try to promote to, in the appropriate 814 // order. Try each of these types. 815 QualType PromoteTypes[6] = { 816 Context.IntTy, Context.UnsignedIntTy, 817 Context.LongTy, Context.UnsignedLongTy , 818 Context.LongLongTy, Context.UnsignedLongLongTy 819 }; 820 for (int Idx = 0; Idx < 6; ++Idx) { 821 uint64_t ToSize = Context.getTypeSize(PromoteTypes[Idx]); 822 if (FromSize < ToSize || 823 (FromSize == ToSize && 824 FromIsSigned == PromoteTypes[Idx]->isSignedIntegerType())) { 825 // We found the type that we can promote to. If this is the 826 // type we wanted, we have a promotion. Otherwise, no 827 // promotion. 828 return Context.hasSameUnqualifiedType(ToType, PromoteTypes[Idx]); 829 } 830 } 831 } 832 833 // An rvalue for an integral bit-field (9.6) can be converted to an 834 // rvalue of type int if int can represent all the values of the 835 // bit-field; otherwise, it can be converted to unsigned int if 836 // unsigned int can represent all the values of the bit-field. If 837 // the bit-field is larger yet, no integral promotion applies to 838 // it. If the bit-field has an enumerated type, it is treated as any 839 // other value of that type for promotion purposes (C++ 4.5p3). 840 // FIXME: We should delay checking of bit-fields until we actually perform the 841 // conversion. 842 using llvm::APSInt; 843 if (From) 844 if (FieldDecl *MemberDecl = From->getBitField()) { 845 APSInt BitWidth; 846 if (FromType->isIntegralType() && !FromType->isEnumeralType() && 847 MemberDecl->getBitWidth()->isIntegerConstantExpr(BitWidth, Context)) { 848 APSInt ToSize(BitWidth.getBitWidth(), BitWidth.isUnsigned()); 849 ToSize = Context.getTypeSize(ToType); 850 851 // Are we promoting to an int from a bitfield that fits in an int? 852 if (BitWidth < ToSize || 853 (FromType->isSignedIntegerType() && BitWidth <= ToSize)) { 854 return To->getKind() == BuiltinType::Int; 855 } 856 857 // Are we promoting to an unsigned int from an unsigned bitfield 858 // that fits into an unsigned int? 859 if (FromType->isUnsignedIntegerType() && BitWidth <= ToSize) { 860 return To->getKind() == BuiltinType::UInt; 861 } 862 863 return false; 864 } 865 } 866 867 // An rvalue of type bool can be converted to an rvalue of type int, 868 // with false becoming zero and true becoming one (C++ 4.5p4). 869 if (FromType->isBooleanType() && To->getKind() == BuiltinType::Int) { 870 return true; 871 } 872 873 return false; 874} 875 876/// IsFloatingPointPromotion - Determines whether the conversion from 877/// FromType to ToType is a floating point promotion (C++ 4.6). If so, 878/// returns true and sets PromotedType to the promoted type. 879bool Sema::IsFloatingPointPromotion(QualType FromType, QualType ToType) { 880 /// An rvalue of type float can be converted to an rvalue of type 881 /// double. (C++ 4.6p1). 882 if (const BuiltinType *FromBuiltin = FromType->getAs<BuiltinType>()) 883 if (const BuiltinType *ToBuiltin = ToType->getAs<BuiltinType>()) { 884 if (FromBuiltin->getKind() == BuiltinType::Float && 885 ToBuiltin->getKind() == BuiltinType::Double) 886 return true; 887 888 // C99 6.3.1.5p1: 889 // When a float is promoted to double or long double, or a 890 // double is promoted to long double [...]. 891 if (!getLangOptions().CPlusPlus && 892 (FromBuiltin->getKind() == BuiltinType::Float || 893 FromBuiltin->getKind() == BuiltinType::Double) && 894 (ToBuiltin->getKind() == BuiltinType::LongDouble)) 895 return true; 896 } 897 898 return false; 899} 900 901/// \brief Determine if a conversion is a complex promotion. 902/// 903/// A complex promotion is defined as a complex -> complex conversion 904/// where the conversion between the underlying real types is a 905/// floating-point or integral promotion. 906bool Sema::IsComplexPromotion(QualType FromType, QualType ToType) { 907 const ComplexType *FromComplex = FromType->getAs<ComplexType>(); 908 if (!FromComplex) 909 return false; 910 911 const ComplexType *ToComplex = ToType->getAs<ComplexType>(); 912 if (!ToComplex) 913 return false; 914 915 return IsFloatingPointPromotion(FromComplex->getElementType(), 916 ToComplex->getElementType()) || 917 IsIntegralPromotion(0, FromComplex->getElementType(), 918 ToComplex->getElementType()); 919} 920 921/// BuildSimilarlyQualifiedPointerType - In a pointer conversion from 922/// the pointer type FromPtr to a pointer to type ToPointee, with the 923/// same type qualifiers as FromPtr has on its pointee type. ToType, 924/// if non-empty, will be a pointer to ToType that may or may not have 925/// the right set of qualifiers on its pointee. 926static QualType 927BuildSimilarlyQualifiedPointerType(const PointerType *FromPtr, 928 QualType ToPointee, QualType ToType, 929 ASTContext &Context) { 930 QualType CanonFromPointee = Context.getCanonicalType(FromPtr->getPointeeType()); 931 QualType CanonToPointee = Context.getCanonicalType(ToPointee); 932 Qualifiers Quals = CanonFromPointee.getQualifiers(); 933 934 // Exact qualifier match -> return the pointer type we're converting to. 935 if (CanonToPointee.getLocalQualifiers() == Quals) { 936 // ToType is exactly what we need. Return it. 937 if (!ToType.isNull()) 938 return ToType; 939 940 // Build a pointer to ToPointee. It has the right qualifiers 941 // already. 942 return Context.getPointerType(ToPointee); 943 } 944 945 // Just build a canonical type that has the right qualifiers. 946 return Context.getPointerType( 947 Context.getQualifiedType(CanonToPointee.getLocalUnqualifiedType(), 948 Quals)); 949} 950 951/// BuildSimilarlyQualifiedObjCObjectPointerType - In a pointer conversion from 952/// the FromType, which is an objective-c pointer, to ToType, which may or may 953/// not have the right set of qualifiers. 954static QualType 955BuildSimilarlyQualifiedObjCObjectPointerType(QualType FromType, 956 QualType ToType, 957 ASTContext &Context) { 958 QualType CanonFromType = Context.getCanonicalType(FromType); 959 QualType CanonToType = Context.getCanonicalType(ToType); 960 Qualifiers Quals = CanonFromType.getQualifiers(); 961 962 // Exact qualifier match -> return the pointer type we're converting to. 963 if (CanonToType.getLocalQualifiers() == Quals) 964 return ToType; 965 966 // Just build a canonical type that has the right qualifiers. 967 return Context.getQualifiedType(CanonToType.getLocalUnqualifiedType(), Quals); 968} 969 970static bool isNullPointerConstantForConversion(Expr *Expr, 971 bool InOverloadResolution, 972 ASTContext &Context) { 973 // Handle value-dependent integral null pointer constants correctly. 974 // http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#903 975 if (Expr->isValueDependent() && !Expr->isTypeDependent() && 976 Expr->getType()->isIntegralType()) 977 return !InOverloadResolution; 978 979 return Expr->isNullPointerConstant(Context, 980 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull 981 : Expr::NPC_ValueDependentIsNull); 982} 983 984/// IsPointerConversion - Determines whether the conversion of the 985/// expression From, which has the (possibly adjusted) type FromType, 986/// can be converted to the type ToType via a pointer conversion (C++ 987/// 4.10). If so, returns true and places the converted type (that 988/// might differ from ToType in its cv-qualifiers at some level) into 989/// ConvertedType. 990/// 991/// This routine also supports conversions to and from block pointers 992/// and conversions with Objective-C's 'id', 'id<protocols...>', and 993/// pointers to interfaces. FIXME: Once we've determined the 994/// appropriate overloading rules for Objective-C, we may want to 995/// split the Objective-C checks into a different routine; however, 996/// GCC seems to consider all of these conversions to be pointer 997/// conversions, so for now they live here. IncompatibleObjC will be 998/// set if the conversion is an allowed Objective-C conversion that 999/// should result in a warning. 1000bool Sema::IsPointerConversion(Expr *From, QualType FromType, QualType ToType, 1001 bool InOverloadResolution, 1002 QualType& ConvertedType, 1003 bool &IncompatibleObjC) { 1004 IncompatibleObjC = false; 1005 if (isObjCPointerConversion(FromType, ToType, ConvertedType, IncompatibleObjC)) 1006 return true; 1007 1008 // Conversion from a null pointer constant to any Objective-C pointer type. 1009 if (ToType->isObjCObjectPointerType() && 1010 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1011 ConvertedType = ToType; 1012 return true; 1013 } 1014 1015 // Blocks: Block pointers can be converted to void*. 1016 if (FromType->isBlockPointerType() && ToType->isPointerType() && 1017 ToType->getAs<PointerType>()->getPointeeType()->isVoidType()) { 1018 ConvertedType = ToType; 1019 return true; 1020 } 1021 // Blocks: A null pointer constant can be converted to a block 1022 // pointer type. 1023 if (ToType->isBlockPointerType() && 1024 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1025 ConvertedType = ToType; 1026 return true; 1027 } 1028 1029 // If the left-hand-side is nullptr_t, the right side can be a null 1030 // pointer constant. 1031 if (ToType->isNullPtrType() && 1032 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1033 ConvertedType = ToType; 1034 return true; 1035 } 1036 1037 const PointerType* ToTypePtr = ToType->getAs<PointerType>(); 1038 if (!ToTypePtr) 1039 return false; 1040 1041 // A null pointer constant can be converted to a pointer type (C++ 4.10p1). 1042 if (isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1043 ConvertedType = ToType; 1044 return true; 1045 } 1046 1047 // Beyond this point, both types need to be pointers 1048 // , including objective-c pointers. 1049 QualType ToPointeeType = ToTypePtr->getPointeeType(); 1050 if (FromType->isObjCObjectPointerType() && ToPointeeType->isVoidType()) { 1051 ConvertedType = BuildSimilarlyQualifiedObjCObjectPointerType(FromType, 1052 ToType, Context); 1053 return true; 1054 1055 } 1056 const PointerType *FromTypePtr = FromType->getAs<PointerType>(); 1057 if (!FromTypePtr) 1058 return false; 1059 1060 QualType FromPointeeType = FromTypePtr->getPointeeType(); 1061 1062 // An rvalue of type "pointer to cv T," where T is an object type, 1063 // can be converted to an rvalue of type "pointer to cv void" (C++ 1064 // 4.10p2). 1065 if (FromPointeeType->isObjectType() && ToPointeeType->isVoidType()) { 1066 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1067 ToPointeeType, 1068 ToType, Context); 1069 return true; 1070 } 1071 1072 // When we're overloading in C, we allow a special kind of pointer 1073 // conversion for compatible-but-not-identical pointee types. 1074 if (!getLangOptions().CPlusPlus && 1075 Context.typesAreCompatible(FromPointeeType, ToPointeeType)) { 1076 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1077 ToPointeeType, 1078 ToType, Context); 1079 return true; 1080 } 1081 1082 // C++ [conv.ptr]p3: 1083 // 1084 // An rvalue of type "pointer to cv D," where D is a class type, 1085 // can be converted to an rvalue of type "pointer to cv B," where 1086 // B is a base class (clause 10) of D. If B is an inaccessible 1087 // (clause 11) or ambiguous (10.2) base class of D, a program that 1088 // necessitates this conversion is ill-formed. The result of the 1089 // conversion is a pointer to the base class sub-object of the 1090 // derived class object. The null pointer value is converted to 1091 // the null pointer value of the destination type. 1092 // 1093 // Note that we do not check for ambiguity or inaccessibility 1094 // here. That is handled by CheckPointerConversion. 1095 if (getLangOptions().CPlusPlus && 1096 FromPointeeType->isRecordType() && ToPointeeType->isRecordType() && 1097 !Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType) && 1098 !RequireCompleteType(From->getLocStart(), FromPointeeType, PDiag()) && 1099 IsDerivedFrom(FromPointeeType, ToPointeeType)) { 1100 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1101 ToPointeeType, 1102 ToType, Context); 1103 return true; 1104 } 1105 1106 return false; 1107} 1108 1109/// isObjCPointerConversion - Determines whether this is an 1110/// Objective-C pointer conversion. Subroutine of IsPointerConversion, 1111/// with the same arguments and return values. 1112bool Sema::isObjCPointerConversion(QualType FromType, QualType ToType, 1113 QualType& ConvertedType, 1114 bool &IncompatibleObjC) { 1115 if (!getLangOptions().ObjC1) 1116 return false; 1117 1118 // First, we handle all conversions on ObjC object pointer types. 1119 const ObjCObjectPointerType* ToObjCPtr = ToType->getAs<ObjCObjectPointerType>(); 1120 const ObjCObjectPointerType *FromObjCPtr = 1121 FromType->getAs<ObjCObjectPointerType>(); 1122 1123 if (ToObjCPtr && FromObjCPtr) { 1124 // Objective C++: We're able to convert between "id" or "Class" and a 1125 // pointer to any interface (in both directions). 1126 if (ToObjCPtr->isObjCBuiltinType() && FromObjCPtr->isObjCBuiltinType()) { 1127 ConvertedType = ToType; 1128 return true; 1129 } 1130 // Conversions with Objective-C's id<...>. 1131 if ((FromObjCPtr->isObjCQualifiedIdType() || 1132 ToObjCPtr->isObjCQualifiedIdType()) && 1133 Context.ObjCQualifiedIdTypesAreCompatible(ToType, FromType, 1134 /*compare=*/false)) { 1135 ConvertedType = ToType; 1136 return true; 1137 } 1138 // Objective C++: We're able to convert from a pointer to an 1139 // interface to a pointer to a different interface. 1140 if (Context.canAssignObjCInterfaces(ToObjCPtr, FromObjCPtr)) { 1141 const ObjCInterfaceType* LHS = ToObjCPtr->getInterfaceType(); 1142 const ObjCInterfaceType* RHS = FromObjCPtr->getInterfaceType(); 1143 if (getLangOptions().CPlusPlus && LHS && RHS && 1144 !ToObjCPtr->getPointeeType().isAtLeastAsQualifiedAs( 1145 FromObjCPtr->getPointeeType())) 1146 return false; 1147 ConvertedType = ToType; 1148 return true; 1149 } 1150 1151 if (Context.canAssignObjCInterfaces(FromObjCPtr, ToObjCPtr)) { 1152 // Okay: this is some kind of implicit downcast of Objective-C 1153 // interfaces, which is permitted. However, we're going to 1154 // complain about it. 1155 IncompatibleObjC = true; 1156 ConvertedType = FromType; 1157 return true; 1158 } 1159 } 1160 // Beyond this point, both types need to be C pointers or block pointers. 1161 QualType ToPointeeType; 1162 if (const PointerType *ToCPtr = ToType->getAs<PointerType>()) 1163 ToPointeeType = ToCPtr->getPointeeType(); 1164 else if (const BlockPointerType *ToBlockPtr = 1165 ToType->getAs<BlockPointerType>()) { 1166 // Objective C++: We're able to convert from a pointer to any object 1167 // to a block pointer type. 1168 if (FromObjCPtr && FromObjCPtr->isObjCBuiltinType()) { 1169 ConvertedType = ToType; 1170 return true; 1171 } 1172 ToPointeeType = ToBlockPtr->getPointeeType(); 1173 } 1174 else if (FromType->getAs<BlockPointerType>() && 1175 ToObjCPtr && ToObjCPtr->isObjCBuiltinType()) { 1176 // Objective C++: We're able to convert from a block pointer type to a 1177 // pointer to any object. 1178 ConvertedType = ToType; 1179 return true; 1180 } 1181 else 1182 return false; 1183 1184 QualType FromPointeeType; 1185 if (const PointerType *FromCPtr = FromType->getAs<PointerType>()) 1186 FromPointeeType = FromCPtr->getPointeeType(); 1187 else if (const BlockPointerType *FromBlockPtr = FromType->getAs<BlockPointerType>()) 1188 FromPointeeType = FromBlockPtr->getPointeeType(); 1189 else 1190 return false; 1191 1192 // If we have pointers to pointers, recursively check whether this 1193 // is an Objective-C conversion. 1194 if (FromPointeeType->isPointerType() && ToPointeeType->isPointerType() && 1195 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, 1196 IncompatibleObjC)) { 1197 // We always complain about this conversion. 1198 IncompatibleObjC = true; 1199 ConvertedType = ToType; 1200 return true; 1201 } 1202 // Allow conversion of pointee being objective-c pointer to another one; 1203 // as in I* to id. 1204 if (FromPointeeType->getAs<ObjCObjectPointerType>() && 1205 ToPointeeType->getAs<ObjCObjectPointerType>() && 1206 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, 1207 IncompatibleObjC)) { 1208 ConvertedType = ToType; 1209 return true; 1210 } 1211 1212 // If we have pointers to functions or blocks, check whether the only 1213 // differences in the argument and result types are in Objective-C 1214 // pointer conversions. If so, we permit the conversion (but 1215 // complain about it). 1216 const FunctionProtoType *FromFunctionType 1217 = FromPointeeType->getAs<FunctionProtoType>(); 1218 const FunctionProtoType *ToFunctionType 1219 = ToPointeeType->getAs<FunctionProtoType>(); 1220 if (FromFunctionType && ToFunctionType) { 1221 // If the function types are exactly the same, this isn't an 1222 // Objective-C pointer conversion. 1223 if (Context.getCanonicalType(FromPointeeType) 1224 == Context.getCanonicalType(ToPointeeType)) 1225 return false; 1226 1227 // Perform the quick checks that will tell us whether these 1228 // function types are obviously different. 1229 if (FromFunctionType->getNumArgs() != ToFunctionType->getNumArgs() || 1230 FromFunctionType->isVariadic() != ToFunctionType->isVariadic() || 1231 FromFunctionType->getTypeQuals() != ToFunctionType->getTypeQuals()) 1232 return false; 1233 1234 bool HasObjCConversion = false; 1235 if (Context.getCanonicalType(FromFunctionType->getResultType()) 1236 == Context.getCanonicalType(ToFunctionType->getResultType())) { 1237 // Okay, the types match exactly. Nothing to do. 1238 } else if (isObjCPointerConversion(FromFunctionType->getResultType(), 1239 ToFunctionType->getResultType(), 1240 ConvertedType, IncompatibleObjC)) { 1241 // Okay, we have an Objective-C pointer conversion. 1242 HasObjCConversion = true; 1243 } else { 1244 // Function types are too different. Abort. 1245 return false; 1246 } 1247 1248 // Check argument types. 1249 for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumArgs(); 1250 ArgIdx != NumArgs; ++ArgIdx) { 1251 QualType FromArgType = FromFunctionType->getArgType(ArgIdx); 1252 QualType ToArgType = ToFunctionType->getArgType(ArgIdx); 1253 if (Context.getCanonicalType(FromArgType) 1254 == Context.getCanonicalType(ToArgType)) { 1255 // Okay, the types match exactly. Nothing to do. 1256 } else if (isObjCPointerConversion(FromArgType, ToArgType, 1257 ConvertedType, IncompatibleObjC)) { 1258 // Okay, we have an Objective-C pointer conversion. 1259 HasObjCConversion = true; 1260 } else { 1261 // Argument types are too different. Abort. 1262 return false; 1263 } 1264 } 1265 1266 if (HasObjCConversion) { 1267 // We had an Objective-C conversion. Allow this pointer 1268 // conversion, but complain about it. 1269 ConvertedType = ToType; 1270 IncompatibleObjC = true; 1271 return true; 1272 } 1273 } 1274 1275 return false; 1276} 1277 1278/// CheckPointerConversion - Check the pointer conversion from the 1279/// expression From to the type ToType. This routine checks for 1280/// ambiguous or inaccessible derived-to-base pointer 1281/// conversions for which IsPointerConversion has already returned 1282/// true. It returns true and produces a diagnostic if there was an 1283/// error, or returns false otherwise. 1284bool Sema::CheckPointerConversion(Expr *From, QualType ToType, 1285 CastExpr::CastKind &Kind, 1286 bool IgnoreBaseAccess) { 1287 QualType FromType = From->getType(); 1288 1289 if (const PointerType *FromPtrType = FromType->getAs<PointerType>()) 1290 if (const PointerType *ToPtrType = ToType->getAs<PointerType>()) { 1291 QualType FromPointeeType = FromPtrType->getPointeeType(), 1292 ToPointeeType = ToPtrType->getPointeeType(); 1293 1294 if (FromPointeeType->isRecordType() && ToPointeeType->isRecordType() && 1295 !Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType)) { 1296 // We must have a derived-to-base conversion. Check an 1297 // ambiguous or inaccessible conversion. 1298 if (CheckDerivedToBaseConversion(FromPointeeType, ToPointeeType, 1299 From->getExprLoc(), 1300 From->getSourceRange(), 1301 IgnoreBaseAccess)) 1302 return true; 1303 1304 // The conversion was successful. 1305 Kind = CastExpr::CK_DerivedToBase; 1306 } 1307 } 1308 if (const ObjCObjectPointerType *FromPtrType = 1309 FromType->getAs<ObjCObjectPointerType>()) 1310 if (const ObjCObjectPointerType *ToPtrType = 1311 ToType->getAs<ObjCObjectPointerType>()) { 1312 // Objective-C++ conversions are always okay. 1313 // FIXME: We should have a different class of conversions for the 1314 // Objective-C++ implicit conversions. 1315 if (FromPtrType->isObjCBuiltinType() || ToPtrType->isObjCBuiltinType()) 1316 return false; 1317 1318 } 1319 return false; 1320} 1321 1322/// IsMemberPointerConversion - Determines whether the conversion of the 1323/// expression From, which has the (possibly adjusted) type FromType, can be 1324/// converted to the type ToType via a member pointer conversion (C++ 4.11). 1325/// If so, returns true and places the converted type (that might differ from 1326/// ToType in its cv-qualifiers at some level) into ConvertedType. 1327bool Sema::IsMemberPointerConversion(Expr *From, QualType FromType, 1328 QualType ToType, 1329 bool InOverloadResolution, 1330 QualType &ConvertedType) { 1331 const MemberPointerType *ToTypePtr = ToType->getAs<MemberPointerType>(); 1332 if (!ToTypePtr) 1333 return false; 1334 1335 // A null pointer constant can be converted to a member pointer (C++ 4.11p1) 1336 if (From->isNullPointerConstant(Context, 1337 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull 1338 : Expr::NPC_ValueDependentIsNull)) { 1339 ConvertedType = ToType; 1340 return true; 1341 } 1342 1343 // Otherwise, both types have to be member pointers. 1344 const MemberPointerType *FromTypePtr = FromType->getAs<MemberPointerType>(); 1345 if (!FromTypePtr) 1346 return false; 1347 1348 // A pointer to member of B can be converted to a pointer to member of D, 1349 // where D is derived from B (C++ 4.11p2). 1350 QualType FromClass(FromTypePtr->getClass(), 0); 1351 QualType ToClass(ToTypePtr->getClass(), 0); 1352 // FIXME: What happens when these are dependent? Is this function even called? 1353 1354 if (IsDerivedFrom(ToClass, FromClass)) { 1355 ConvertedType = Context.getMemberPointerType(FromTypePtr->getPointeeType(), 1356 ToClass.getTypePtr()); 1357 return true; 1358 } 1359 1360 return false; 1361} 1362 1363/// CheckMemberPointerConversion - Check the member pointer conversion from the 1364/// expression From to the type ToType. This routine checks for ambiguous or 1365/// virtual or inaccessible base-to-derived member pointer conversions 1366/// for which IsMemberPointerConversion has already returned true. It returns 1367/// true and produces a diagnostic if there was an error, or returns false 1368/// otherwise. 1369bool Sema::CheckMemberPointerConversion(Expr *From, QualType ToType, 1370 CastExpr::CastKind &Kind, 1371 bool IgnoreBaseAccess) { 1372 QualType FromType = From->getType(); 1373 const MemberPointerType *FromPtrType = FromType->getAs<MemberPointerType>(); 1374 if (!FromPtrType) { 1375 // This must be a null pointer to member pointer conversion 1376 assert(From->isNullPointerConstant(Context, 1377 Expr::NPC_ValueDependentIsNull) && 1378 "Expr must be null pointer constant!"); 1379 Kind = CastExpr::CK_NullToMemberPointer; 1380 return false; 1381 } 1382 1383 const MemberPointerType *ToPtrType = ToType->getAs<MemberPointerType>(); 1384 assert(ToPtrType && "No member pointer cast has a target type " 1385 "that is not a member pointer."); 1386 1387 QualType FromClass = QualType(FromPtrType->getClass(), 0); 1388 QualType ToClass = QualType(ToPtrType->getClass(), 0); 1389 1390 // FIXME: What about dependent types? 1391 assert(FromClass->isRecordType() && "Pointer into non-class."); 1392 assert(ToClass->isRecordType() && "Pointer into non-class."); 1393 1394 CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/ true, 1395 /*DetectVirtual=*/true); 1396 bool DerivationOkay = IsDerivedFrom(ToClass, FromClass, Paths); 1397 assert(DerivationOkay && 1398 "Should not have been called if derivation isn't OK."); 1399 (void)DerivationOkay; 1400 1401 if (Paths.isAmbiguous(Context.getCanonicalType(FromClass). 1402 getUnqualifiedType())) { 1403 std::string PathDisplayStr = getAmbiguousPathsDisplayString(Paths); 1404 Diag(From->getExprLoc(), diag::err_ambiguous_memptr_conv) 1405 << 0 << FromClass << ToClass << PathDisplayStr << From->getSourceRange(); 1406 return true; 1407 } 1408 1409 if (const RecordType *VBase = Paths.getDetectedVirtual()) { 1410 Diag(From->getExprLoc(), diag::err_memptr_conv_via_virtual) 1411 << FromClass << ToClass << QualType(VBase, 0) 1412 << From->getSourceRange(); 1413 return true; 1414 } 1415 1416 if (!IgnoreBaseAccess) 1417 CheckBaseClassAccess(From->getExprLoc(), FromClass, ToClass, 1418 Paths.front(), 1419 diag::err_downcast_from_inaccessible_base); 1420 1421 // Must be a base to derived member conversion. 1422 Kind = CastExpr::CK_BaseToDerivedMemberPointer; 1423 return false; 1424} 1425 1426/// IsQualificationConversion - Determines whether the conversion from 1427/// an rvalue of type FromType to ToType is a qualification conversion 1428/// (C++ 4.4). 1429bool 1430Sema::IsQualificationConversion(QualType FromType, QualType ToType) { 1431 FromType = Context.getCanonicalType(FromType); 1432 ToType = Context.getCanonicalType(ToType); 1433 1434 // If FromType and ToType are the same type, this is not a 1435 // qualification conversion. 1436 if (FromType.getUnqualifiedType() == ToType.getUnqualifiedType()) 1437 return false; 1438 1439 // (C++ 4.4p4): 1440 // A conversion can add cv-qualifiers at levels other than the first 1441 // in multi-level pointers, subject to the following rules: [...] 1442 bool PreviousToQualsIncludeConst = true; 1443 bool UnwrappedAnyPointer = false; 1444 while (UnwrapSimilarPointerTypes(FromType, ToType)) { 1445 // Within each iteration of the loop, we check the qualifiers to 1446 // determine if this still looks like a qualification 1447 // conversion. Then, if all is well, we unwrap one more level of 1448 // pointers or pointers-to-members and do it all again 1449 // until there are no more pointers or pointers-to-members left to 1450 // unwrap. 1451 UnwrappedAnyPointer = true; 1452 1453 // -- for every j > 0, if const is in cv 1,j then const is in cv 1454 // 2,j, and similarly for volatile. 1455 if (!ToType.isAtLeastAsQualifiedAs(FromType)) 1456 return false; 1457 1458 // -- if the cv 1,j and cv 2,j are different, then const is in 1459 // every cv for 0 < k < j. 1460 if (FromType.getCVRQualifiers() != ToType.getCVRQualifiers() 1461 && !PreviousToQualsIncludeConst) 1462 return false; 1463 1464 // Keep track of whether all prior cv-qualifiers in the "to" type 1465 // include const. 1466 PreviousToQualsIncludeConst 1467 = PreviousToQualsIncludeConst && ToType.isConstQualified(); 1468 } 1469 1470 // We are left with FromType and ToType being the pointee types 1471 // after unwrapping the original FromType and ToType the same number 1472 // of types. If we unwrapped any pointers, and if FromType and 1473 // ToType have the same unqualified type (since we checked 1474 // qualifiers above), then this is a qualification conversion. 1475 return UnwrappedAnyPointer && Context.hasSameUnqualifiedType(FromType,ToType); 1476} 1477 1478/// Determines whether there is a user-defined conversion sequence 1479/// (C++ [over.ics.user]) that converts expression From to the type 1480/// ToType. If such a conversion exists, User will contain the 1481/// user-defined conversion sequence that performs such a conversion 1482/// and this routine will return true. Otherwise, this routine returns 1483/// false and User is unspecified. 1484/// 1485/// \param AllowConversionFunctions true if the conversion should 1486/// consider conversion functions at all. If false, only constructors 1487/// will be considered. 1488/// 1489/// \param AllowExplicit true if the conversion should consider C++0x 1490/// "explicit" conversion functions as well as non-explicit conversion 1491/// functions (C++0x [class.conv.fct]p2). 1492/// 1493/// \param ForceRValue true if the expression should be treated as an rvalue 1494/// for overload resolution. 1495/// \param UserCast true if looking for user defined conversion for a static 1496/// cast. 1497OverloadingResult Sema::IsUserDefinedConversion(Expr *From, QualType ToType, 1498 UserDefinedConversionSequence& User, 1499 OverloadCandidateSet& CandidateSet, 1500 bool AllowConversionFunctions, 1501 bool AllowExplicit, 1502 bool ForceRValue, 1503 bool UserCast) { 1504 if (const RecordType *ToRecordType = ToType->getAs<RecordType>()) { 1505 if (RequireCompleteType(From->getLocStart(), ToType, PDiag())) { 1506 // We're not going to find any constructors. 1507 } else if (CXXRecordDecl *ToRecordDecl 1508 = dyn_cast<CXXRecordDecl>(ToRecordType->getDecl())) { 1509 // C++ [over.match.ctor]p1: 1510 // When objects of class type are direct-initialized (8.5), or 1511 // copy-initialized from an expression of the same or a 1512 // derived class type (8.5), overload resolution selects the 1513 // constructor. [...] For copy-initialization, the candidate 1514 // functions are all the converting constructors (12.3.1) of 1515 // that class. The argument list is the expression-list within 1516 // the parentheses of the initializer. 1517 bool SuppressUserConversions = !UserCast; 1518 if (Context.hasSameUnqualifiedType(ToType, From->getType()) || 1519 IsDerivedFrom(From->getType(), ToType)) { 1520 SuppressUserConversions = false; 1521 AllowConversionFunctions = false; 1522 } 1523 1524 DeclarationName ConstructorName 1525 = Context.DeclarationNames.getCXXConstructorName( 1526 Context.getCanonicalType(ToType).getUnqualifiedType()); 1527 DeclContext::lookup_iterator Con, ConEnd; 1528 for (llvm::tie(Con, ConEnd) 1529 = ToRecordDecl->lookup(ConstructorName); 1530 Con != ConEnd; ++Con) { 1531 NamedDecl *D = *Con; 1532 DeclAccessPair FoundDecl = DeclAccessPair::make(D, D->getAccess()); 1533 1534 // Find the constructor (which may be a template). 1535 CXXConstructorDecl *Constructor = 0; 1536 FunctionTemplateDecl *ConstructorTmpl 1537 = dyn_cast<FunctionTemplateDecl>(D); 1538 if (ConstructorTmpl) 1539 Constructor 1540 = cast<CXXConstructorDecl>(ConstructorTmpl->getTemplatedDecl()); 1541 else 1542 Constructor = cast<CXXConstructorDecl>(D); 1543 1544 if (!Constructor->isInvalidDecl() && 1545 Constructor->isConvertingConstructor(AllowExplicit)) { 1546 if (ConstructorTmpl) 1547 AddTemplateOverloadCandidate(ConstructorTmpl, FoundDecl, 1548 /*ExplicitArgs*/ 0, 1549 &From, 1, CandidateSet, 1550 SuppressUserConversions, ForceRValue); 1551 else 1552 // Allow one user-defined conversion when user specifies a 1553 // From->ToType conversion via an static cast (c-style, etc). 1554 AddOverloadCandidate(Constructor, FoundDecl, 1555 &From, 1, CandidateSet, 1556 SuppressUserConversions, ForceRValue); 1557 } 1558 } 1559 } 1560 } 1561 1562 if (!AllowConversionFunctions) { 1563 // Don't allow any conversion functions to enter the overload set. 1564 } else if (RequireCompleteType(From->getLocStart(), From->getType(), 1565 PDiag(0) 1566 << From->getSourceRange())) { 1567 // No conversion functions from incomplete types. 1568 } else if (const RecordType *FromRecordType 1569 = From->getType()->getAs<RecordType>()) { 1570 if (CXXRecordDecl *FromRecordDecl 1571 = dyn_cast<CXXRecordDecl>(FromRecordType->getDecl())) { 1572 // Add all of the conversion functions as candidates. 1573 const UnresolvedSetImpl *Conversions 1574 = FromRecordDecl->getVisibleConversionFunctions(); 1575 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 1576 E = Conversions->end(); I != E; ++I) { 1577 DeclAccessPair FoundDecl = I.getPair(); 1578 NamedDecl *D = FoundDecl.getDecl(); 1579 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext()); 1580 if (isa<UsingShadowDecl>(D)) 1581 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 1582 1583 CXXConversionDecl *Conv; 1584 FunctionTemplateDecl *ConvTemplate; 1585 if ((ConvTemplate = dyn_cast<FunctionTemplateDecl>(D))) 1586 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 1587 else 1588 Conv = cast<CXXConversionDecl>(D); 1589 1590 if (AllowExplicit || !Conv->isExplicit()) { 1591 if (ConvTemplate) 1592 AddTemplateConversionCandidate(ConvTemplate, FoundDecl, 1593 ActingContext, From, ToType, 1594 CandidateSet); 1595 else 1596 AddConversionCandidate(Conv, FoundDecl, ActingContext, 1597 From, ToType, CandidateSet); 1598 } 1599 } 1600 } 1601 } 1602 1603 OverloadCandidateSet::iterator Best; 1604 switch (BestViableFunction(CandidateSet, From->getLocStart(), Best)) { 1605 case OR_Success: 1606 // Record the standard conversion we used and the conversion function. 1607 if (CXXConstructorDecl *Constructor 1608 = dyn_cast<CXXConstructorDecl>(Best->Function)) { 1609 // C++ [over.ics.user]p1: 1610 // If the user-defined conversion is specified by a 1611 // constructor (12.3.1), the initial standard conversion 1612 // sequence converts the source type to the type required by 1613 // the argument of the constructor. 1614 // 1615 QualType ThisType = Constructor->getThisType(Context); 1616 if (Best->Conversions[0].isEllipsis()) 1617 User.EllipsisConversion = true; 1618 else { 1619 User.Before = Best->Conversions[0].Standard; 1620 User.EllipsisConversion = false; 1621 } 1622 User.ConversionFunction = Constructor; 1623 User.After.setAsIdentityConversion(); 1624 User.After.setFromType( 1625 ThisType->getAs<PointerType>()->getPointeeType()); 1626 User.After.setAllToTypes(ToType); 1627 return OR_Success; 1628 } else if (CXXConversionDecl *Conversion 1629 = dyn_cast<CXXConversionDecl>(Best->Function)) { 1630 // C++ [over.ics.user]p1: 1631 // 1632 // [...] If the user-defined conversion is specified by a 1633 // conversion function (12.3.2), the initial standard 1634 // conversion sequence converts the source type to the 1635 // implicit object parameter of the conversion function. 1636 User.Before = Best->Conversions[0].Standard; 1637 User.ConversionFunction = Conversion; 1638 User.EllipsisConversion = false; 1639 1640 // C++ [over.ics.user]p2: 1641 // The second standard conversion sequence converts the 1642 // result of the user-defined conversion to the target type 1643 // for the sequence. Since an implicit conversion sequence 1644 // is an initialization, the special rules for 1645 // initialization by user-defined conversion apply when 1646 // selecting the best user-defined conversion for a 1647 // user-defined conversion sequence (see 13.3.3 and 1648 // 13.3.3.1). 1649 User.After = Best->FinalConversion; 1650 return OR_Success; 1651 } else { 1652 assert(false && "Not a constructor or conversion function?"); 1653 return OR_No_Viable_Function; 1654 } 1655 1656 case OR_No_Viable_Function: 1657 return OR_No_Viable_Function; 1658 case OR_Deleted: 1659 // No conversion here! We're done. 1660 return OR_Deleted; 1661 1662 case OR_Ambiguous: 1663 return OR_Ambiguous; 1664 } 1665 1666 return OR_No_Viable_Function; 1667} 1668 1669bool 1670Sema::DiagnoseMultipleUserDefinedConversion(Expr *From, QualType ToType) { 1671 ImplicitConversionSequence ICS; 1672 OverloadCandidateSet CandidateSet(From->getExprLoc()); 1673 OverloadingResult OvResult = 1674 IsUserDefinedConversion(From, ToType, ICS.UserDefined, 1675 CandidateSet, true, false, false); 1676 if (OvResult == OR_Ambiguous) 1677 Diag(From->getSourceRange().getBegin(), 1678 diag::err_typecheck_ambiguous_condition) 1679 << From->getType() << ToType << From->getSourceRange(); 1680 else if (OvResult == OR_No_Viable_Function && !CandidateSet.empty()) 1681 Diag(From->getSourceRange().getBegin(), 1682 diag::err_typecheck_nonviable_condition) 1683 << From->getType() << ToType << From->getSourceRange(); 1684 else 1685 return false; 1686 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, &From, 1); 1687 return true; 1688} 1689 1690/// CompareImplicitConversionSequences - Compare two implicit 1691/// conversion sequences to determine whether one is better than the 1692/// other or if they are indistinguishable (C++ 13.3.3.2). 1693ImplicitConversionSequence::CompareKind 1694Sema::CompareImplicitConversionSequences(const ImplicitConversionSequence& ICS1, 1695 const ImplicitConversionSequence& ICS2) 1696{ 1697 // (C++ 13.3.3.2p2): When comparing the basic forms of implicit 1698 // conversion sequences (as defined in 13.3.3.1) 1699 // -- a standard conversion sequence (13.3.3.1.1) is a better 1700 // conversion sequence than a user-defined conversion sequence or 1701 // an ellipsis conversion sequence, and 1702 // -- a user-defined conversion sequence (13.3.3.1.2) is a better 1703 // conversion sequence than an ellipsis conversion sequence 1704 // (13.3.3.1.3). 1705 // 1706 // C++0x [over.best.ics]p10: 1707 // For the purpose of ranking implicit conversion sequences as 1708 // described in 13.3.3.2, the ambiguous conversion sequence is 1709 // treated as a user-defined sequence that is indistinguishable 1710 // from any other user-defined conversion sequence. 1711 if (ICS1.getKind() < ICS2.getKind()) { 1712 if (!(ICS1.isUserDefined() && ICS2.isAmbiguous())) 1713 return ImplicitConversionSequence::Better; 1714 } else if (ICS2.getKind() < ICS1.getKind()) { 1715 if (!(ICS2.isUserDefined() && ICS1.isAmbiguous())) 1716 return ImplicitConversionSequence::Worse; 1717 } 1718 1719 if (ICS1.isAmbiguous() || ICS2.isAmbiguous()) 1720 return ImplicitConversionSequence::Indistinguishable; 1721 1722 // Two implicit conversion sequences of the same form are 1723 // indistinguishable conversion sequences unless one of the 1724 // following rules apply: (C++ 13.3.3.2p3): 1725 if (ICS1.isStandard()) 1726 return CompareStandardConversionSequences(ICS1.Standard, ICS2.Standard); 1727 else if (ICS1.isUserDefined()) { 1728 // User-defined conversion sequence U1 is a better conversion 1729 // sequence than another user-defined conversion sequence U2 if 1730 // they contain the same user-defined conversion function or 1731 // constructor and if the second standard conversion sequence of 1732 // U1 is better than the second standard conversion sequence of 1733 // U2 (C++ 13.3.3.2p3). 1734 if (ICS1.UserDefined.ConversionFunction == 1735 ICS2.UserDefined.ConversionFunction) 1736 return CompareStandardConversionSequences(ICS1.UserDefined.After, 1737 ICS2.UserDefined.After); 1738 } 1739 1740 return ImplicitConversionSequence::Indistinguishable; 1741} 1742 1743// Per 13.3.3.2p3, compare the given standard conversion sequences to 1744// determine if one is a proper subset of the other. 1745static ImplicitConversionSequence::CompareKind 1746compareStandardConversionSubsets(ASTContext &Context, 1747 const StandardConversionSequence& SCS1, 1748 const StandardConversionSequence& SCS2) { 1749 ImplicitConversionSequence::CompareKind Result 1750 = ImplicitConversionSequence::Indistinguishable; 1751 1752 if (SCS1.Second != SCS2.Second) { 1753 if (SCS1.Second == ICK_Identity) 1754 Result = ImplicitConversionSequence::Better; 1755 else if (SCS2.Second == ICK_Identity) 1756 Result = ImplicitConversionSequence::Worse; 1757 else 1758 return ImplicitConversionSequence::Indistinguishable; 1759 } else if (!Context.hasSameType(SCS1.getToType(1), SCS2.getToType(1))) 1760 return ImplicitConversionSequence::Indistinguishable; 1761 1762 if (SCS1.Third == SCS2.Third) { 1763 return Context.hasSameType(SCS1.getToType(2), SCS2.getToType(2))? Result 1764 : ImplicitConversionSequence::Indistinguishable; 1765 } 1766 1767 if (SCS1.Third == ICK_Identity) 1768 return Result == ImplicitConversionSequence::Worse 1769 ? ImplicitConversionSequence::Indistinguishable 1770 : ImplicitConversionSequence::Better; 1771 1772 if (SCS2.Third == ICK_Identity) 1773 return Result == ImplicitConversionSequence::Better 1774 ? ImplicitConversionSequence::Indistinguishable 1775 : ImplicitConversionSequence::Worse; 1776 1777 return ImplicitConversionSequence::Indistinguishable; 1778} 1779 1780/// CompareStandardConversionSequences - Compare two standard 1781/// conversion sequences to determine whether one is better than the 1782/// other or if they are indistinguishable (C++ 13.3.3.2p3). 1783ImplicitConversionSequence::CompareKind 1784Sema::CompareStandardConversionSequences(const StandardConversionSequence& SCS1, 1785 const StandardConversionSequence& SCS2) 1786{ 1787 // Standard conversion sequence S1 is a better conversion sequence 1788 // than standard conversion sequence S2 if (C++ 13.3.3.2p3): 1789 1790 // -- S1 is a proper subsequence of S2 (comparing the conversion 1791 // sequences in the canonical form defined by 13.3.3.1.1, 1792 // excluding any Lvalue Transformation; the identity conversion 1793 // sequence is considered to be a subsequence of any 1794 // non-identity conversion sequence) or, if not that, 1795 if (ImplicitConversionSequence::CompareKind CK 1796 = compareStandardConversionSubsets(Context, SCS1, SCS2)) 1797 return CK; 1798 1799 // -- the rank of S1 is better than the rank of S2 (by the rules 1800 // defined below), or, if not that, 1801 ImplicitConversionRank Rank1 = SCS1.getRank(); 1802 ImplicitConversionRank Rank2 = SCS2.getRank(); 1803 if (Rank1 < Rank2) 1804 return ImplicitConversionSequence::Better; 1805 else if (Rank2 < Rank1) 1806 return ImplicitConversionSequence::Worse; 1807 1808 // (C++ 13.3.3.2p4): Two conversion sequences with the same rank 1809 // are indistinguishable unless one of the following rules 1810 // applies: 1811 1812 // A conversion that is not a conversion of a pointer, or 1813 // pointer to member, to bool is better than another conversion 1814 // that is such a conversion. 1815 if (SCS1.isPointerConversionToBool() != SCS2.isPointerConversionToBool()) 1816 return SCS2.isPointerConversionToBool() 1817 ? ImplicitConversionSequence::Better 1818 : ImplicitConversionSequence::Worse; 1819 1820 // C++ [over.ics.rank]p4b2: 1821 // 1822 // If class B is derived directly or indirectly from class A, 1823 // conversion of B* to A* is better than conversion of B* to 1824 // void*, and conversion of A* to void* is better than conversion 1825 // of B* to void*. 1826 bool SCS1ConvertsToVoid 1827 = SCS1.isPointerConversionToVoidPointer(Context); 1828 bool SCS2ConvertsToVoid 1829 = SCS2.isPointerConversionToVoidPointer(Context); 1830 if (SCS1ConvertsToVoid != SCS2ConvertsToVoid) { 1831 // Exactly one of the conversion sequences is a conversion to 1832 // a void pointer; it's the worse conversion. 1833 return SCS2ConvertsToVoid ? ImplicitConversionSequence::Better 1834 : ImplicitConversionSequence::Worse; 1835 } else if (!SCS1ConvertsToVoid && !SCS2ConvertsToVoid) { 1836 // Neither conversion sequence converts to a void pointer; compare 1837 // their derived-to-base conversions. 1838 if (ImplicitConversionSequence::CompareKind DerivedCK 1839 = CompareDerivedToBaseConversions(SCS1, SCS2)) 1840 return DerivedCK; 1841 } else if (SCS1ConvertsToVoid && SCS2ConvertsToVoid) { 1842 // Both conversion sequences are conversions to void 1843 // pointers. Compare the source types to determine if there's an 1844 // inheritance relationship in their sources. 1845 QualType FromType1 = SCS1.getFromType(); 1846 QualType FromType2 = SCS2.getFromType(); 1847 1848 // Adjust the types we're converting from via the array-to-pointer 1849 // conversion, if we need to. 1850 if (SCS1.First == ICK_Array_To_Pointer) 1851 FromType1 = Context.getArrayDecayedType(FromType1); 1852 if (SCS2.First == ICK_Array_To_Pointer) 1853 FromType2 = Context.getArrayDecayedType(FromType2); 1854 1855 QualType FromPointee1 1856 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1857 QualType FromPointee2 1858 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1859 1860 if (IsDerivedFrom(FromPointee2, FromPointee1)) 1861 return ImplicitConversionSequence::Better; 1862 else if (IsDerivedFrom(FromPointee1, FromPointee2)) 1863 return ImplicitConversionSequence::Worse; 1864 1865 // Objective-C++: If one interface is more specific than the 1866 // other, it is the better one. 1867 const ObjCInterfaceType* FromIface1 = FromPointee1->getAs<ObjCInterfaceType>(); 1868 const ObjCInterfaceType* FromIface2 = FromPointee2->getAs<ObjCInterfaceType>(); 1869 if (FromIface1 && FromIface1) { 1870 if (Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 1871 return ImplicitConversionSequence::Better; 1872 else if (Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 1873 return ImplicitConversionSequence::Worse; 1874 } 1875 } 1876 1877 // Compare based on qualification conversions (C++ 13.3.3.2p3, 1878 // bullet 3). 1879 if (ImplicitConversionSequence::CompareKind QualCK 1880 = CompareQualificationConversions(SCS1, SCS2)) 1881 return QualCK; 1882 1883 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding) { 1884 // C++0x [over.ics.rank]p3b4: 1885 // -- S1 and S2 are reference bindings (8.5.3) and neither refers to an 1886 // implicit object parameter of a non-static member function declared 1887 // without a ref-qualifier, and S1 binds an rvalue reference to an 1888 // rvalue and S2 binds an lvalue reference. 1889 // FIXME: We don't know if we're dealing with the implicit object parameter, 1890 // or if the member function in this case has a ref qualifier. 1891 // (Of course, we don't have ref qualifiers yet.) 1892 if (SCS1.RRefBinding != SCS2.RRefBinding) 1893 return SCS1.RRefBinding ? ImplicitConversionSequence::Better 1894 : ImplicitConversionSequence::Worse; 1895 1896 // C++ [over.ics.rank]p3b4: 1897 // -- S1 and S2 are reference bindings (8.5.3), and the types to 1898 // which the references refer are the same type except for 1899 // top-level cv-qualifiers, and the type to which the reference 1900 // initialized by S2 refers is more cv-qualified than the type 1901 // to which the reference initialized by S1 refers. 1902 QualType T1 = SCS1.getToType(2); 1903 QualType T2 = SCS2.getToType(2); 1904 T1 = Context.getCanonicalType(T1); 1905 T2 = Context.getCanonicalType(T2); 1906 Qualifiers T1Quals, T2Quals; 1907 QualType UnqualT1 = Context.getUnqualifiedArrayType(T1, T1Quals); 1908 QualType UnqualT2 = Context.getUnqualifiedArrayType(T2, T2Quals); 1909 if (UnqualT1 == UnqualT2) { 1910 // If the type is an array type, promote the element qualifiers to the type 1911 // for comparison. 1912 if (isa<ArrayType>(T1) && T1Quals) 1913 T1 = Context.getQualifiedType(UnqualT1, T1Quals); 1914 if (isa<ArrayType>(T2) && T2Quals) 1915 T2 = Context.getQualifiedType(UnqualT2, T2Quals); 1916 if (T2.isMoreQualifiedThan(T1)) 1917 return ImplicitConversionSequence::Better; 1918 else if (T1.isMoreQualifiedThan(T2)) 1919 return ImplicitConversionSequence::Worse; 1920 } 1921 } 1922 1923 return ImplicitConversionSequence::Indistinguishable; 1924} 1925 1926/// CompareQualificationConversions - Compares two standard conversion 1927/// sequences to determine whether they can be ranked based on their 1928/// qualification conversions (C++ 13.3.3.2p3 bullet 3). 1929ImplicitConversionSequence::CompareKind 1930Sema::CompareQualificationConversions(const StandardConversionSequence& SCS1, 1931 const StandardConversionSequence& SCS2) { 1932 // C++ 13.3.3.2p3: 1933 // -- S1 and S2 differ only in their qualification conversion and 1934 // yield similar types T1 and T2 (C++ 4.4), respectively, and the 1935 // cv-qualification signature of type T1 is a proper subset of 1936 // the cv-qualification signature of type T2, and S1 is not the 1937 // deprecated string literal array-to-pointer conversion (4.2). 1938 if (SCS1.First != SCS2.First || SCS1.Second != SCS2.Second || 1939 SCS1.Third != SCS2.Third || SCS1.Third != ICK_Qualification) 1940 return ImplicitConversionSequence::Indistinguishable; 1941 1942 // FIXME: the example in the standard doesn't use a qualification 1943 // conversion (!) 1944 QualType T1 = SCS1.getToType(2); 1945 QualType T2 = SCS2.getToType(2); 1946 T1 = Context.getCanonicalType(T1); 1947 T2 = Context.getCanonicalType(T2); 1948 Qualifiers T1Quals, T2Quals; 1949 QualType UnqualT1 = Context.getUnqualifiedArrayType(T1, T1Quals); 1950 QualType UnqualT2 = Context.getUnqualifiedArrayType(T2, T2Quals); 1951 1952 // If the types are the same, we won't learn anything by unwrapped 1953 // them. 1954 if (UnqualT1 == UnqualT2) 1955 return ImplicitConversionSequence::Indistinguishable; 1956 1957 // If the type is an array type, promote the element qualifiers to the type 1958 // for comparison. 1959 if (isa<ArrayType>(T1) && T1Quals) 1960 T1 = Context.getQualifiedType(UnqualT1, T1Quals); 1961 if (isa<ArrayType>(T2) && T2Quals) 1962 T2 = Context.getQualifiedType(UnqualT2, T2Quals); 1963 1964 ImplicitConversionSequence::CompareKind Result 1965 = ImplicitConversionSequence::Indistinguishable; 1966 while (UnwrapSimilarPointerTypes(T1, T2)) { 1967 // Within each iteration of the loop, we check the qualifiers to 1968 // determine if this still looks like a qualification 1969 // conversion. Then, if all is well, we unwrap one more level of 1970 // pointers or pointers-to-members and do it all again 1971 // until there are no more pointers or pointers-to-members left 1972 // to unwrap. This essentially mimics what 1973 // IsQualificationConversion does, but here we're checking for a 1974 // strict subset of qualifiers. 1975 if (T1.getCVRQualifiers() == T2.getCVRQualifiers()) 1976 // The qualifiers are the same, so this doesn't tell us anything 1977 // about how the sequences rank. 1978 ; 1979 else if (T2.isMoreQualifiedThan(T1)) { 1980 // T1 has fewer qualifiers, so it could be the better sequence. 1981 if (Result == ImplicitConversionSequence::Worse) 1982 // Neither has qualifiers that are a subset of the other's 1983 // qualifiers. 1984 return ImplicitConversionSequence::Indistinguishable; 1985 1986 Result = ImplicitConversionSequence::Better; 1987 } else if (T1.isMoreQualifiedThan(T2)) { 1988 // T2 has fewer qualifiers, so it could be the better sequence. 1989 if (Result == ImplicitConversionSequence::Better) 1990 // Neither has qualifiers that are a subset of the other's 1991 // qualifiers. 1992 return ImplicitConversionSequence::Indistinguishable; 1993 1994 Result = ImplicitConversionSequence::Worse; 1995 } else { 1996 // Qualifiers are disjoint. 1997 return ImplicitConversionSequence::Indistinguishable; 1998 } 1999 2000 // If the types after this point are equivalent, we're done. 2001 if (Context.hasSameUnqualifiedType(T1, T2)) 2002 break; 2003 } 2004 2005 // Check that the winning standard conversion sequence isn't using 2006 // the deprecated string literal array to pointer conversion. 2007 switch (Result) { 2008 case ImplicitConversionSequence::Better: 2009 if (SCS1.DeprecatedStringLiteralToCharPtr) 2010 Result = ImplicitConversionSequence::Indistinguishable; 2011 break; 2012 2013 case ImplicitConversionSequence::Indistinguishable: 2014 break; 2015 2016 case ImplicitConversionSequence::Worse: 2017 if (SCS2.DeprecatedStringLiteralToCharPtr) 2018 Result = ImplicitConversionSequence::Indistinguishable; 2019 break; 2020 } 2021 2022 return Result; 2023} 2024 2025/// CompareDerivedToBaseConversions - Compares two standard conversion 2026/// sequences to determine whether they can be ranked based on their 2027/// various kinds of derived-to-base conversions (C++ 2028/// [over.ics.rank]p4b3). As part of these checks, we also look at 2029/// conversions between Objective-C interface types. 2030ImplicitConversionSequence::CompareKind 2031Sema::CompareDerivedToBaseConversions(const StandardConversionSequence& SCS1, 2032 const StandardConversionSequence& SCS2) { 2033 QualType FromType1 = SCS1.getFromType(); 2034 QualType ToType1 = SCS1.getToType(1); 2035 QualType FromType2 = SCS2.getFromType(); 2036 QualType ToType2 = SCS2.getToType(1); 2037 2038 // Adjust the types we're converting from via the array-to-pointer 2039 // conversion, if we need to. 2040 if (SCS1.First == ICK_Array_To_Pointer) 2041 FromType1 = Context.getArrayDecayedType(FromType1); 2042 if (SCS2.First == ICK_Array_To_Pointer) 2043 FromType2 = Context.getArrayDecayedType(FromType2); 2044 2045 // Canonicalize all of the types. 2046 FromType1 = Context.getCanonicalType(FromType1); 2047 ToType1 = Context.getCanonicalType(ToType1); 2048 FromType2 = Context.getCanonicalType(FromType2); 2049 ToType2 = Context.getCanonicalType(ToType2); 2050 2051 // C++ [over.ics.rank]p4b3: 2052 // 2053 // If class B is derived directly or indirectly from class A and 2054 // class C is derived directly or indirectly from B, 2055 // 2056 // For Objective-C, we let A, B, and C also be Objective-C 2057 // interfaces. 2058 2059 // Compare based on pointer conversions. 2060 if (SCS1.Second == ICK_Pointer_Conversion && 2061 SCS2.Second == ICK_Pointer_Conversion && 2062 /*FIXME: Remove if Objective-C id conversions get their own rank*/ 2063 FromType1->isPointerType() && FromType2->isPointerType() && 2064 ToType1->isPointerType() && ToType2->isPointerType()) { 2065 QualType FromPointee1 2066 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2067 QualType ToPointee1 2068 = ToType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2069 QualType FromPointee2 2070 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2071 QualType ToPointee2 2072 = ToType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2073 2074 const ObjCInterfaceType* FromIface1 = FromPointee1->getAs<ObjCInterfaceType>(); 2075 const ObjCInterfaceType* FromIface2 = FromPointee2->getAs<ObjCInterfaceType>(); 2076 const ObjCInterfaceType* ToIface1 = ToPointee1->getAs<ObjCInterfaceType>(); 2077 const ObjCInterfaceType* ToIface2 = ToPointee2->getAs<ObjCInterfaceType>(); 2078 2079 // -- conversion of C* to B* is better than conversion of C* to A*, 2080 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 2081 if (IsDerivedFrom(ToPointee1, ToPointee2)) 2082 return ImplicitConversionSequence::Better; 2083 else if (IsDerivedFrom(ToPointee2, ToPointee1)) 2084 return ImplicitConversionSequence::Worse; 2085 2086 if (ToIface1 && ToIface2) { 2087 if (Context.canAssignObjCInterfaces(ToIface2, ToIface1)) 2088 return ImplicitConversionSequence::Better; 2089 else if (Context.canAssignObjCInterfaces(ToIface1, ToIface2)) 2090 return ImplicitConversionSequence::Worse; 2091 } 2092 } 2093 2094 // -- conversion of B* to A* is better than conversion of C* to A*, 2095 if (FromPointee1 != FromPointee2 && ToPointee1 == ToPointee2) { 2096 if (IsDerivedFrom(FromPointee2, FromPointee1)) 2097 return ImplicitConversionSequence::Better; 2098 else if (IsDerivedFrom(FromPointee1, FromPointee2)) 2099 return ImplicitConversionSequence::Worse; 2100 2101 if (FromIface1 && FromIface2) { 2102 if (Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 2103 return ImplicitConversionSequence::Better; 2104 else if (Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 2105 return ImplicitConversionSequence::Worse; 2106 } 2107 } 2108 } 2109 2110 // Ranking of member-pointer types. 2111 if (SCS1.Second == ICK_Pointer_Member && SCS2.Second == ICK_Pointer_Member && 2112 FromType1->isMemberPointerType() && FromType2->isMemberPointerType() && 2113 ToType1->isMemberPointerType() && ToType2->isMemberPointerType()) { 2114 const MemberPointerType * FromMemPointer1 = 2115 FromType1->getAs<MemberPointerType>(); 2116 const MemberPointerType * ToMemPointer1 = 2117 ToType1->getAs<MemberPointerType>(); 2118 const MemberPointerType * FromMemPointer2 = 2119 FromType2->getAs<MemberPointerType>(); 2120 const MemberPointerType * ToMemPointer2 = 2121 ToType2->getAs<MemberPointerType>(); 2122 const Type *FromPointeeType1 = FromMemPointer1->getClass(); 2123 const Type *ToPointeeType1 = ToMemPointer1->getClass(); 2124 const Type *FromPointeeType2 = FromMemPointer2->getClass(); 2125 const Type *ToPointeeType2 = ToMemPointer2->getClass(); 2126 QualType FromPointee1 = QualType(FromPointeeType1, 0).getUnqualifiedType(); 2127 QualType ToPointee1 = QualType(ToPointeeType1, 0).getUnqualifiedType(); 2128 QualType FromPointee2 = QualType(FromPointeeType2, 0).getUnqualifiedType(); 2129 QualType ToPointee2 = QualType(ToPointeeType2, 0).getUnqualifiedType(); 2130 // conversion of A::* to B::* is better than conversion of A::* to C::*, 2131 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 2132 if (IsDerivedFrom(ToPointee1, ToPointee2)) 2133 return ImplicitConversionSequence::Worse; 2134 else if (IsDerivedFrom(ToPointee2, ToPointee1)) 2135 return ImplicitConversionSequence::Better; 2136 } 2137 // conversion of B::* to C::* is better than conversion of A::* to C::* 2138 if (ToPointee1 == ToPointee2 && FromPointee1 != FromPointee2) { 2139 if (IsDerivedFrom(FromPointee1, FromPointee2)) 2140 return ImplicitConversionSequence::Better; 2141 else if (IsDerivedFrom(FromPointee2, FromPointee1)) 2142 return ImplicitConversionSequence::Worse; 2143 } 2144 } 2145 2146 if ((SCS1.ReferenceBinding || SCS1.CopyConstructor) && 2147 (SCS2.ReferenceBinding || SCS2.CopyConstructor) && 2148 SCS1.Second == ICK_Derived_To_Base) { 2149 // -- conversion of C to B is better than conversion of C to A, 2150 // -- binding of an expression of type C to a reference of type 2151 // B& is better than binding an expression of type C to a 2152 // reference of type A&, 2153 if (Context.hasSameUnqualifiedType(FromType1, FromType2) && 2154 !Context.hasSameUnqualifiedType(ToType1, ToType2)) { 2155 if (IsDerivedFrom(ToType1, ToType2)) 2156 return ImplicitConversionSequence::Better; 2157 else if (IsDerivedFrom(ToType2, ToType1)) 2158 return ImplicitConversionSequence::Worse; 2159 } 2160 2161 // -- conversion of B to A is better than conversion of C to A. 2162 // -- binding of an expression of type B to a reference of type 2163 // A& is better than binding an expression of type C to a 2164 // reference of type A&, 2165 if (!Context.hasSameUnqualifiedType(FromType1, FromType2) && 2166 Context.hasSameUnqualifiedType(ToType1, ToType2)) { 2167 if (IsDerivedFrom(FromType2, FromType1)) 2168 return ImplicitConversionSequence::Better; 2169 else if (IsDerivedFrom(FromType1, FromType2)) 2170 return ImplicitConversionSequence::Worse; 2171 } 2172 } 2173 2174 return ImplicitConversionSequence::Indistinguishable; 2175} 2176 2177/// CompareReferenceRelationship - Compare the two types T1 and T2 to 2178/// determine whether they are reference-related, 2179/// reference-compatible, reference-compatible with added 2180/// qualification, or incompatible, for use in C++ initialization by 2181/// reference (C++ [dcl.ref.init]p4). Neither type can be a reference 2182/// type, and the first type (T1) is the pointee type of the reference 2183/// type being initialized. 2184Sema::ReferenceCompareResult 2185Sema::CompareReferenceRelationship(SourceLocation Loc, 2186 QualType OrigT1, QualType OrigT2, 2187 bool& DerivedToBase) { 2188 assert(!OrigT1->isReferenceType() && 2189 "T1 must be the pointee type of the reference type"); 2190 assert(!OrigT2->isReferenceType() && "T2 cannot be a reference type"); 2191 2192 QualType T1 = Context.getCanonicalType(OrigT1); 2193 QualType T2 = Context.getCanonicalType(OrigT2); 2194 Qualifiers T1Quals, T2Quals; 2195 QualType UnqualT1 = Context.getUnqualifiedArrayType(T1, T1Quals); 2196 QualType UnqualT2 = Context.getUnqualifiedArrayType(T2, T2Quals); 2197 2198 // C++ [dcl.init.ref]p4: 2199 // Given types "cv1 T1" and "cv2 T2," "cv1 T1" is 2200 // reference-related to "cv2 T2" if T1 is the same type as T2, or 2201 // T1 is a base class of T2. 2202 if (UnqualT1 == UnqualT2) 2203 DerivedToBase = false; 2204 else if (!RequireCompleteType(Loc, OrigT1, PDiag()) && 2205 !RequireCompleteType(Loc, OrigT2, PDiag()) && 2206 IsDerivedFrom(UnqualT2, UnqualT1)) 2207 DerivedToBase = true; 2208 else 2209 return Ref_Incompatible; 2210 2211 // At this point, we know that T1 and T2 are reference-related (at 2212 // least). 2213 2214 // If the type is an array type, promote the element qualifiers to the type 2215 // for comparison. 2216 if (isa<ArrayType>(T1) && T1Quals) 2217 T1 = Context.getQualifiedType(UnqualT1, T1Quals); 2218 if (isa<ArrayType>(T2) && T2Quals) 2219 T2 = Context.getQualifiedType(UnqualT2, T2Quals); 2220 2221 // C++ [dcl.init.ref]p4: 2222 // "cv1 T1" is reference-compatible with "cv2 T2" if T1 is 2223 // reference-related to T2 and cv1 is the same cv-qualification 2224 // as, or greater cv-qualification than, cv2. For purposes of 2225 // overload resolution, cases for which cv1 is greater 2226 // cv-qualification than cv2 are identified as 2227 // reference-compatible with added qualification (see 13.3.3.2). 2228 if (T1Quals.getCVRQualifiers() == T2Quals.getCVRQualifiers()) 2229 return Ref_Compatible; 2230 else if (T1.isMoreQualifiedThan(T2)) 2231 return Ref_Compatible_With_Added_Qualification; 2232 else 2233 return Ref_Related; 2234} 2235 2236/// \brief Compute an implicit conversion sequence for reference 2237/// initialization. 2238static ImplicitConversionSequence 2239TryReferenceInit(Sema &S, Expr *&Init, QualType DeclType, 2240 SourceLocation DeclLoc, 2241 bool SuppressUserConversions, 2242 bool AllowExplicit, bool ForceRValue) { 2243 assert(DeclType->isReferenceType() && "Reference init needs a reference"); 2244 2245 // Most paths end in a failed conversion. 2246 ImplicitConversionSequence ICS; 2247 ICS.setBad(BadConversionSequence::no_conversion, Init, DeclType); 2248 2249 QualType T1 = DeclType->getAs<ReferenceType>()->getPointeeType(); 2250 QualType T2 = Init->getType(); 2251 2252 // If the initializer is the address of an overloaded function, try 2253 // to resolve the overloaded function. If all goes well, T2 is the 2254 // type of the resulting function. 2255 if (S.Context.getCanonicalType(T2) == S.Context.OverloadTy) { 2256 DeclAccessPair Found; 2257 if (FunctionDecl *Fn = S.ResolveAddressOfOverloadedFunction(Init, DeclType, 2258 false, Found)) 2259 T2 = Fn->getType(); 2260 } 2261 2262 // Compute some basic properties of the types and the initializer. 2263 bool isRValRef = DeclType->isRValueReferenceType(); 2264 bool DerivedToBase = false; 2265 Expr::isLvalueResult InitLvalue = ForceRValue ? Expr::LV_InvalidExpression : 2266 Init->isLvalue(S.Context); 2267 Sema::ReferenceCompareResult RefRelationship 2268 = S.CompareReferenceRelationship(DeclLoc, T1, T2, DerivedToBase); 2269 2270 // C++ [dcl.init.ref]p5: 2271 // A reference to type "cv1 T1" is initialized by an expression 2272 // of type "cv2 T2" as follows: 2273 2274 // -- If the initializer expression 2275 2276 // C++ [over.ics.ref]p3: 2277 // Except for an implicit object parameter, for which see 13.3.1, 2278 // a standard conversion sequence cannot be formed if it requires 2279 // binding an lvalue reference to non-const to an rvalue or 2280 // binding an rvalue reference to an lvalue. 2281 if (isRValRef && InitLvalue == Expr::LV_Valid) 2282 return ICS; 2283 2284 // -- is an lvalue (but is not a bit-field), and "cv1 T1" is 2285 // reference-compatible with "cv2 T2," or 2286 // 2287 // Per C++ [over.ics.ref]p4, we don't check the bit-field property here. 2288 if (InitLvalue == Expr::LV_Valid && 2289 RefRelationship >= Sema::Ref_Compatible_With_Added_Qualification) { 2290 // C++ [over.ics.ref]p1: 2291 // When a parameter of reference type binds directly (8.5.3) 2292 // to an argument expression, the implicit conversion sequence 2293 // is the identity conversion, unless the argument expression 2294 // has a type that is a derived class of the parameter type, 2295 // in which case the implicit conversion sequence is a 2296 // derived-to-base Conversion (13.3.3.1). 2297 ICS.setStandard(); 2298 ICS.Standard.First = ICK_Identity; 2299 ICS.Standard.Second = DerivedToBase? ICK_Derived_To_Base : ICK_Identity; 2300 ICS.Standard.Third = ICK_Identity; 2301 ICS.Standard.FromTypePtr = T2.getAsOpaquePtr(); 2302 ICS.Standard.setToType(0, T2); 2303 ICS.Standard.setToType(1, T1); 2304 ICS.Standard.setToType(2, T1); 2305 ICS.Standard.ReferenceBinding = true; 2306 ICS.Standard.DirectBinding = true; 2307 ICS.Standard.RRefBinding = false; 2308 ICS.Standard.CopyConstructor = 0; 2309 2310 // Nothing more to do: the inaccessibility/ambiguity check for 2311 // derived-to-base conversions is suppressed when we're 2312 // computing the implicit conversion sequence (C++ 2313 // [over.best.ics]p2). 2314 return ICS; 2315 } 2316 2317 // -- has a class type (i.e., T2 is a class type), where T1 is 2318 // not reference-related to T2, and can be implicitly 2319 // converted to an lvalue of type "cv3 T3," where "cv1 T1" 2320 // is reference-compatible with "cv3 T3" 92) (this 2321 // conversion is selected by enumerating the applicable 2322 // conversion functions (13.3.1.6) and choosing the best 2323 // one through overload resolution (13.3)), 2324 if (!isRValRef && !SuppressUserConversions && T2->isRecordType() && 2325 !S.RequireCompleteType(DeclLoc, T2, 0) && 2326 RefRelationship == Sema::Ref_Incompatible) { 2327 CXXRecordDecl *T2RecordDecl 2328 = dyn_cast<CXXRecordDecl>(T2->getAs<RecordType>()->getDecl()); 2329 2330 OverloadCandidateSet CandidateSet(DeclLoc); 2331 const UnresolvedSetImpl *Conversions 2332 = T2RecordDecl->getVisibleConversionFunctions(); 2333 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 2334 E = Conversions->end(); I != E; ++I) { 2335 NamedDecl *D = *I; 2336 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(D->getDeclContext()); 2337 if (isa<UsingShadowDecl>(D)) 2338 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 2339 2340 FunctionTemplateDecl *ConvTemplate 2341 = dyn_cast<FunctionTemplateDecl>(D); 2342 CXXConversionDecl *Conv; 2343 if (ConvTemplate) 2344 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 2345 else 2346 Conv = cast<CXXConversionDecl>(D); 2347 2348 // If the conversion function doesn't return a reference type, 2349 // it can't be considered for this conversion. 2350 if (Conv->getConversionType()->isLValueReferenceType() && 2351 (AllowExplicit || !Conv->isExplicit())) { 2352 if (ConvTemplate) 2353 S.AddTemplateConversionCandidate(ConvTemplate, I.getPair(), ActingDC, 2354 Init, DeclType, CandidateSet); 2355 else 2356 S.AddConversionCandidate(Conv, I.getPair(), ActingDC, Init, 2357 DeclType, CandidateSet); 2358 } 2359 } 2360 2361 OverloadCandidateSet::iterator Best; 2362 switch (S.BestViableFunction(CandidateSet, DeclLoc, Best)) { 2363 case OR_Success: 2364 // C++ [over.ics.ref]p1: 2365 // 2366 // [...] If the parameter binds directly to the result of 2367 // applying a conversion function to the argument 2368 // expression, the implicit conversion sequence is a 2369 // user-defined conversion sequence (13.3.3.1.2), with the 2370 // second standard conversion sequence either an identity 2371 // conversion or, if the conversion function returns an 2372 // entity of a type that is a derived class of the parameter 2373 // type, a derived-to-base Conversion. 2374 if (!Best->FinalConversion.DirectBinding) 2375 break; 2376 2377 ICS.setUserDefined(); 2378 ICS.UserDefined.Before = Best->Conversions[0].Standard; 2379 ICS.UserDefined.After = Best->FinalConversion; 2380 ICS.UserDefined.ConversionFunction = Best->Function; 2381 ICS.UserDefined.EllipsisConversion = false; 2382 assert(ICS.UserDefined.After.ReferenceBinding && 2383 ICS.UserDefined.After.DirectBinding && 2384 "Expected a direct reference binding!"); 2385 return ICS; 2386 2387 case OR_Ambiguous: 2388 ICS.setAmbiguous(); 2389 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 2390 Cand != CandidateSet.end(); ++Cand) 2391 if (Cand->Viable) 2392 ICS.Ambiguous.addConversion(Cand->Function); 2393 return ICS; 2394 2395 case OR_No_Viable_Function: 2396 case OR_Deleted: 2397 // There was no suitable conversion, or we found a deleted 2398 // conversion; continue with other checks. 2399 break; 2400 } 2401 } 2402 2403 // -- Otherwise, the reference shall be to a non-volatile const 2404 // type (i.e., cv1 shall be const), or the reference shall be an 2405 // rvalue reference and the initializer expression shall be an rvalue. 2406 if (!isRValRef && T1.getCVRQualifiers() != Qualifiers::Const) 2407 return ICS; 2408 2409 // -- If the initializer expression is an rvalue, with T2 a 2410 // class type, and "cv1 T1" is reference-compatible with 2411 // "cv2 T2," the reference is bound in one of the 2412 // following ways (the choice is implementation-defined): 2413 // 2414 // -- The reference is bound to the object represented by 2415 // the rvalue (see 3.10) or to a sub-object within that 2416 // object. 2417 // 2418 // -- A temporary of type "cv1 T2" [sic] is created, and 2419 // a constructor is called to copy the entire rvalue 2420 // object into the temporary. The reference is bound to 2421 // the temporary or to a sub-object within the 2422 // temporary. 2423 // 2424 // The constructor that would be used to make the copy 2425 // shall be callable whether or not the copy is actually 2426 // done. 2427 // 2428 // Note that C++0x [dcl.init.ref]p5 takes away this implementation 2429 // freedom, so we will always take the first option and never build 2430 // a temporary in this case. 2431 if (InitLvalue != Expr::LV_Valid && T2->isRecordType() && 2432 RefRelationship >= Sema::Ref_Compatible_With_Added_Qualification) { 2433 ICS.setStandard(); 2434 ICS.Standard.First = ICK_Identity; 2435 ICS.Standard.Second = DerivedToBase? ICK_Derived_To_Base : ICK_Identity; 2436 ICS.Standard.Third = ICK_Identity; 2437 ICS.Standard.FromTypePtr = T2.getAsOpaquePtr(); 2438 ICS.Standard.setToType(0, T2); 2439 ICS.Standard.setToType(1, T1); 2440 ICS.Standard.setToType(2, T1); 2441 ICS.Standard.ReferenceBinding = true; 2442 ICS.Standard.DirectBinding = false; 2443 ICS.Standard.RRefBinding = isRValRef; 2444 ICS.Standard.CopyConstructor = 0; 2445 return ICS; 2446 } 2447 2448 // -- Otherwise, a temporary of type "cv1 T1" is created and 2449 // initialized from the initializer expression using the 2450 // rules for a non-reference copy initialization (8.5). The 2451 // reference is then bound to the temporary. If T1 is 2452 // reference-related to T2, cv1 must be the same 2453 // cv-qualification as, or greater cv-qualification than, 2454 // cv2; otherwise, the program is ill-formed. 2455 if (RefRelationship == Sema::Ref_Related) { 2456 // If cv1 == cv2 or cv1 is a greater cv-qualified than cv2, then 2457 // we would be reference-compatible or reference-compatible with 2458 // added qualification. But that wasn't the case, so the reference 2459 // initialization fails. 2460 return ICS; 2461 } 2462 2463 // If at least one of the types is a class type, the types are not 2464 // related, and we aren't allowed any user conversions, the 2465 // reference binding fails. This case is important for breaking 2466 // recursion, since TryImplicitConversion below will attempt to 2467 // create a temporary through the use of a copy constructor. 2468 if (SuppressUserConversions && RefRelationship == Sema::Ref_Incompatible && 2469 (T1->isRecordType() || T2->isRecordType())) 2470 return ICS; 2471 2472 // C++ [over.ics.ref]p2: 2473 // 2474 // When a parameter of reference type is not bound directly to 2475 // an argument expression, the conversion sequence is the one 2476 // required to convert the argument expression to the 2477 // underlying type of the reference according to 2478 // 13.3.3.1. Conceptually, this conversion sequence corresponds 2479 // to copy-initializing a temporary of the underlying type with 2480 // the argument expression. Any difference in top-level 2481 // cv-qualification is subsumed by the initialization itself 2482 // and does not constitute a conversion. 2483 ICS = S.TryImplicitConversion(Init, T1, SuppressUserConversions, 2484 /*AllowExplicit=*/false, 2485 /*ForceRValue=*/false, 2486 /*InOverloadResolution=*/false); 2487 2488 // Of course, that's still a reference binding. 2489 if (ICS.isStandard()) { 2490 ICS.Standard.ReferenceBinding = true; 2491 ICS.Standard.RRefBinding = isRValRef; 2492 } else if (ICS.isUserDefined()) { 2493 ICS.UserDefined.After.ReferenceBinding = true; 2494 ICS.UserDefined.After.RRefBinding = isRValRef; 2495 } 2496 return ICS; 2497} 2498 2499/// TryCopyInitialization - Try to copy-initialize a value of type 2500/// ToType from the expression From. Return the implicit conversion 2501/// sequence required to pass this argument, which may be a bad 2502/// conversion sequence (meaning that the argument cannot be passed to 2503/// a parameter of this type). If @p SuppressUserConversions, then we 2504/// do not permit any user-defined conversion sequences. If @p ForceRValue, 2505/// then we treat @p From as an rvalue, even if it is an lvalue. 2506ImplicitConversionSequence 2507Sema::TryCopyInitialization(Expr *From, QualType ToType, 2508 bool SuppressUserConversions, bool ForceRValue, 2509 bool InOverloadResolution) { 2510 if (ToType->isReferenceType()) 2511 return TryReferenceInit(*this, From, ToType, 2512 /*FIXME:*/From->getLocStart(), 2513 SuppressUserConversions, 2514 /*AllowExplicit=*/false, 2515 ForceRValue); 2516 2517 return 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/// If @p ForceRValue, treat all arguments as rvalues. This is a slightly 2664/// hacky way to implement the overloading rules for elidable copy 2665/// initialization in C++0x (C++0x 12.8p15). 2666/// 2667/// \para PartialOverloading true if we are performing "partial" overloading 2668/// based on an incomplete set of function arguments. This feature is used by 2669/// code completion. 2670void 2671Sema::AddOverloadCandidate(FunctionDecl *Function, 2672 DeclAccessPair FoundDecl, 2673 Expr **Args, unsigned NumArgs, 2674 OverloadCandidateSet& CandidateSet, 2675 bool SuppressUserConversions, 2676 bool ForceRValue, 2677 bool PartialOverloading) { 2678 const FunctionProtoType* Proto 2679 = dyn_cast<FunctionProtoType>(Function->getType()->getAs<FunctionType>()); 2680 assert(Proto && "Functions without a prototype cannot be overloaded"); 2681 assert(!Function->getDescribedFunctionTemplate() && 2682 "Use AddTemplateOverloadCandidate for function templates"); 2683 2684 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Function)) { 2685 if (!isa<CXXConstructorDecl>(Method)) { 2686 // If we get here, it's because we're calling a member function 2687 // that is named without a member access expression (e.g., 2688 // "this->f") that was either written explicitly or created 2689 // implicitly. This can happen with a qualified call to a member 2690 // function, e.g., X::f(). We use an empty type for the implied 2691 // object argument (C++ [over.call.func]p3), and the acting context 2692 // is irrelevant. 2693 AddMethodCandidate(Method, FoundDecl, Method->getParent(), 2694 QualType(), Args, NumArgs, CandidateSet, 2695 SuppressUserConversions, ForceRValue); 2696 return; 2697 } 2698 // We treat a constructor like a non-member function, since its object 2699 // argument doesn't participate in overload resolution. 2700 } 2701 2702 if (!CandidateSet.isNewCandidate(Function)) 2703 return; 2704 2705 // Overload resolution is always an unevaluated context. 2706 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 2707 2708 if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(Function)){ 2709 // C++ [class.copy]p3: 2710 // A member function template is never instantiated to perform the copy 2711 // of a class object to an object of its class type. 2712 QualType ClassType = Context.getTypeDeclType(Constructor->getParent()); 2713 if (NumArgs == 1 && 2714 Constructor->isCopyConstructorLikeSpecialization() && 2715 (Context.hasSameUnqualifiedType(ClassType, Args[0]->getType()) || 2716 IsDerivedFrom(Args[0]->getType(), ClassType))) 2717 return; 2718 } 2719 2720 // Add this candidate 2721 CandidateSet.push_back(OverloadCandidate()); 2722 OverloadCandidate& Candidate = CandidateSet.back(); 2723 Candidate.FoundDecl = FoundDecl; 2724 Candidate.Function = Function; 2725 Candidate.Viable = true; 2726 Candidate.IsSurrogate = false; 2727 Candidate.IgnoreObjectArgument = false; 2728 2729 unsigned NumArgsInProto = Proto->getNumArgs(); 2730 2731 // (C++ 13.3.2p2): A candidate function having fewer than m 2732 // parameters is viable only if it has an ellipsis in its parameter 2733 // list (8.3.5). 2734 if ((NumArgs + (PartialOverloading && NumArgs)) > NumArgsInProto && 2735 !Proto->isVariadic()) { 2736 Candidate.Viable = false; 2737 Candidate.FailureKind = ovl_fail_too_many_arguments; 2738 return; 2739 } 2740 2741 // (C++ 13.3.2p2): A candidate function having more than m parameters 2742 // is viable only if the (m+1)st parameter has a default argument 2743 // (8.3.6). For the purposes of overload resolution, the 2744 // parameter list is truncated on the right, so that there are 2745 // exactly m parameters. 2746 unsigned MinRequiredArgs = Function->getMinRequiredArguments(); 2747 if (NumArgs < MinRequiredArgs && !PartialOverloading) { 2748 // Not enough arguments. 2749 Candidate.Viable = false; 2750 Candidate.FailureKind = ovl_fail_too_few_arguments; 2751 return; 2752 } 2753 2754 // Determine the implicit conversion sequences for each of the 2755 // arguments. 2756 Candidate.Conversions.resize(NumArgs); 2757 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2758 if (ArgIdx < NumArgsInProto) { 2759 // (C++ 13.3.2p3): for F to be a viable function, there shall 2760 // exist for each argument an implicit conversion sequence 2761 // (13.3.3.1) that converts that argument to the corresponding 2762 // parameter of F. 2763 QualType ParamType = Proto->getArgType(ArgIdx); 2764 Candidate.Conversions[ArgIdx] 2765 = TryCopyInitialization(Args[ArgIdx], ParamType, 2766 SuppressUserConversions, ForceRValue, 2767 /*InOverloadResolution=*/true); 2768 if (Candidate.Conversions[ArgIdx].isBad()) { 2769 Candidate.Viable = false; 2770 Candidate.FailureKind = ovl_fail_bad_conversion; 2771 break; 2772 } 2773 } else { 2774 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2775 // argument for which there is no corresponding parameter is 2776 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2777 Candidate.Conversions[ArgIdx].setEllipsis(); 2778 } 2779 } 2780} 2781 2782/// \brief Add all of the function declarations in the given function set to 2783/// the overload canddiate set. 2784void Sema::AddFunctionCandidates(const UnresolvedSetImpl &Fns, 2785 Expr **Args, unsigned NumArgs, 2786 OverloadCandidateSet& CandidateSet, 2787 bool SuppressUserConversions) { 2788 for (UnresolvedSetIterator F = Fns.begin(), E = Fns.end(); F != E; ++F) { 2789 NamedDecl *D = F.getDecl()->getUnderlyingDecl(); 2790 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { 2791 if (isa<CXXMethodDecl>(FD) && !cast<CXXMethodDecl>(FD)->isStatic()) 2792 AddMethodCandidate(cast<CXXMethodDecl>(FD), F.getPair(), 2793 cast<CXXMethodDecl>(FD)->getParent(), 2794 Args[0]->getType(), Args + 1, NumArgs - 1, 2795 CandidateSet, SuppressUserConversions); 2796 else 2797 AddOverloadCandidate(FD, F.getPair(), Args, NumArgs, CandidateSet, 2798 SuppressUserConversions); 2799 } else { 2800 FunctionTemplateDecl *FunTmpl = cast<FunctionTemplateDecl>(D); 2801 if (isa<CXXMethodDecl>(FunTmpl->getTemplatedDecl()) && 2802 !cast<CXXMethodDecl>(FunTmpl->getTemplatedDecl())->isStatic()) 2803 AddMethodTemplateCandidate(FunTmpl, F.getPair(), 2804 cast<CXXRecordDecl>(FunTmpl->getDeclContext()), 2805 /*FIXME: explicit args */ 0, 2806 Args[0]->getType(), Args + 1, NumArgs - 1, 2807 CandidateSet, 2808 SuppressUserConversions); 2809 else 2810 AddTemplateOverloadCandidate(FunTmpl, F.getPair(), 2811 /*FIXME: explicit args */ 0, 2812 Args, NumArgs, CandidateSet, 2813 SuppressUserConversions); 2814 } 2815 } 2816} 2817 2818/// AddMethodCandidate - Adds a named decl (which is some kind of 2819/// method) as a method candidate to the given overload set. 2820void Sema::AddMethodCandidate(DeclAccessPair FoundDecl, 2821 QualType ObjectType, 2822 Expr **Args, unsigned NumArgs, 2823 OverloadCandidateSet& CandidateSet, 2824 bool SuppressUserConversions, bool ForceRValue) { 2825 NamedDecl *Decl = FoundDecl.getDecl(); 2826 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(Decl->getDeclContext()); 2827 2828 if (isa<UsingShadowDecl>(Decl)) 2829 Decl = cast<UsingShadowDecl>(Decl)->getTargetDecl(); 2830 2831 if (FunctionTemplateDecl *TD = dyn_cast<FunctionTemplateDecl>(Decl)) { 2832 assert(isa<CXXMethodDecl>(TD->getTemplatedDecl()) && 2833 "Expected a member function template"); 2834 AddMethodTemplateCandidate(TD, FoundDecl, ActingContext, 2835 /*ExplicitArgs*/ 0, 2836 ObjectType, Args, NumArgs, 2837 CandidateSet, 2838 SuppressUserConversions, 2839 ForceRValue); 2840 } else { 2841 AddMethodCandidate(cast<CXXMethodDecl>(Decl), FoundDecl, ActingContext, 2842 ObjectType, Args, NumArgs, 2843 CandidateSet, SuppressUserConversions, ForceRValue); 2844 } 2845} 2846 2847/// AddMethodCandidate - Adds the given C++ member function to the set 2848/// of candidate functions, using the given function call arguments 2849/// and the object argument (@c Object). For example, in a call 2850/// @c o.f(a1,a2), @c Object will contain @c o and @c Args will contain 2851/// both @c a1 and @c a2. If @p SuppressUserConversions, then don't 2852/// allow user-defined conversions via constructors or conversion 2853/// operators. If @p ForceRValue, treat all arguments as rvalues. This is 2854/// a slightly hacky way to implement the overloading rules for elidable copy 2855/// initialization in C++0x (C++0x 12.8p15). 2856void 2857Sema::AddMethodCandidate(CXXMethodDecl *Method, DeclAccessPair FoundDecl, 2858 CXXRecordDecl *ActingContext, QualType ObjectType, 2859 Expr **Args, unsigned NumArgs, 2860 OverloadCandidateSet& CandidateSet, 2861 bool SuppressUserConversions, bool ForceRValue) { 2862 const FunctionProtoType* Proto 2863 = dyn_cast<FunctionProtoType>(Method->getType()->getAs<FunctionType>()); 2864 assert(Proto && "Methods without a prototype cannot be overloaded"); 2865 assert(!isa<CXXConstructorDecl>(Method) && 2866 "Use AddOverloadCandidate for constructors"); 2867 2868 if (!CandidateSet.isNewCandidate(Method)) 2869 return; 2870 2871 // Overload resolution is always an unevaluated context. 2872 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 2873 2874 // Add this candidate 2875 CandidateSet.push_back(OverloadCandidate()); 2876 OverloadCandidate& Candidate = CandidateSet.back(); 2877 Candidate.FoundDecl = FoundDecl; 2878 Candidate.Function = Method; 2879 Candidate.IsSurrogate = false; 2880 Candidate.IgnoreObjectArgument = false; 2881 2882 unsigned NumArgsInProto = Proto->getNumArgs(); 2883 2884 // (C++ 13.3.2p2): A candidate function having fewer than m 2885 // parameters is viable only if it has an ellipsis in its parameter 2886 // list (8.3.5). 2887 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 2888 Candidate.Viable = false; 2889 Candidate.FailureKind = ovl_fail_too_many_arguments; 2890 return; 2891 } 2892 2893 // (C++ 13.3.2p2): A candidate function having more than m parameters 2894 // is viable only if the (m+1)st parameter has a default argument 2895 // (8.3.6). For the purposes of overload resolution, the 2896 // parameter list is truncated on the right, so that there are 2897 // exactly m parameters. 2898 unsigned MinRequiredArgs = Method->getMinRequiredArguments(); 2899 if (NumArgs < MinRequiredArgs) { 2900 // Not enough arguments. 2901 Candidate.Viable = false; 2902 Candidate.FailureKind = ovl_fail_too_few_arguments; 2903 return; 2904 } 2905 2906 Candidate.Viable = true; 2907 Candidate.Conversions.resize(NumArgs + 1); 2908 2909 if (Method->isStatic() || ObjectType.isNull()) 2910 // The implicit object argument is ignored. 2911 Candidate.IgnoreObjectArgument = true; 2912 else { 2913 // Determine the implicit conversion sequence for the object 2914 // parameter. 2915 Candidate.Conversions[0] 2916 = TryObjectArgumentInitialization(ObjectType, Method, ActingContext); 2917 if (Candidate.Conversions[0].isBad()) { 2918 Candidate.Viable = false; 2919 Candidate.FailureKind = ovl_fail_bad_conversion; 2920 return; 2921 } 2922 } 2923 2924 // Determine the implicit conversion sequences for each of the 2925 // arguments. 2926 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2927 if (ArgIdx < NumArgsInProto) { 2928 // (C++ 13.3.2p3): for F to be a viable function, there shall 2929 // exist for each argument an implicit conversion sequence 2930 // (13.3.3.1) that converts that argument to the corresponding 2931 // parameter of F. 2932 QualType ParamType = Proto->getArgType(ArgIdx); 2933 Candidate.Conversions[ArgIdx + 1] 2934 = TryCopyInitialization(Args[ArgIdx], ParamType, 2935 SuppressUserConversions, ForceRValue, 2936 /*InOverloadResolution=*/true); 2937 if (Candidate.Conversions[ArgIdx + 1].isBad()) { 2938 Candidate.Viable = false; 2939 Candidate.FailureKind = ovl_fail_bad_conversion; 2940 break; 2941 } 2942 } else { 2943 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2944 // argument for which there is no corresponding parameter is 2945 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2946 Candidate.Conversions[ArgIdx + 1].setEllipsis(); 2947 } 2948 } 2949} 2950 2951/// \brief Add a C++ member function template as a candidate to the candidate 2952/// set, using template argument deduction to produce an appropriate member 2953/// function template specialization. 2954void 2955Sema::AddMethodTemplateCandidate(FunctionTemplateDecl *MethodTmpl, 2956 DeclAccessPair FoundDecl, 2957 CXXRecordDecl *ActingContext, 2958 const TemplateArgumentListInfo *ExplicitTemplateArgs, 2959 QualType ObjectType, 2960 Expr **Args, unsigned NumArgs, 2961 OverloadCandidateSet& CandidateSet, 2962 bool SuppressUserConversions, 2963 bool ForceRValue) { 2964 if (!CandidateSet.isNewCandidate(MethodTmpl)) 2965 return; 2966 2967 // C++ [over.match.funcs]p7: 2968 // In each case where a candidate is a function template, candidate 2969 // function template specializations are generated using template argument 2970 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 2971 // candidate functions in the usual way.113) A given name can refer to one 2972 // or more function templates and also to a set of overloaded non-template 2973 // functions. In such a case, the candidate functions generated from each 2974 // function template are combined with the set of non-template candidate 2975 // functions. 2976 TemplateDeductionInfo Info(Context, CandidateSet.getLocation()); 2977 FunctionDecl *Specialization = 0; 2978 if (TemplateDeductionResult Result 2979 = DeduceTemplateArguments(MethodTmpl, ExplicitTemplateArgs, 2980 Args, NumArgs, Specialization, Info)) { 2981 // FIXME: Record what happened with template argument deduction, so 2982 // that we can give the user a beautiful diagnostic. 2983 (void)Result; 2984 return; 2985 } 2986 2987 // Add the function template specialization produced by template argument 2988 // deduction as a candidate. 2989 assert(Specialization && "Missing member function template specialization?"); 2990 assert(isa<CXXMethodDecl>(Specialization) && 2991 "Specialization is not a member function?"); 2992 AddMethodCandidate(cast<CXXMethodDecl>(Specialization), FoundDecl, 2993 ActingContext, ObjectType, Args, NumArgs, 2994 CandidateSet, SuppressUserConversions, ForceRValue); 2995} 2996 2997/// \brief Add a C++ function template specialization as a candidate 2998/// in the candidate set, using template argument deduction to produce 2999/// an appropriate function template specialization. 3000void 3001Sema::AddTemplateOverloadCandidate(FunctionTemplateDecl *FunctionTemplate, 3002 DeclAccessPair FoundDecl, 3003 const TemplateArgumentListInfo *ExplicitTemplateArgs, 3004 Expr **Args, unsigned NumArgs, 3005 OverloadCandidateSet& CandidateSet, 3006 bool SuppressUserConversions, 3007 bool ForceRValue) { 3008 if (!CandidateSet.isNewCandidate(FunctionTemplate)) 3009 return; 3010 3011 // C++ [over.match.funcs]p7: 3012 // In each case where a candidate is a function template, candidate 3013 // function template specializations are generated using template argument 3014 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 3015 // candidate functions in the usual way.113) A given name can refer to one 3016 // or more function templates and also to a set of overloaded non-template 3017 // functions. In such a case, the candidate functions generated from each 3018 // function template are combined with the set of non-template candidate 3019 // functions. 3020 TemplateDeductionInfo Info(Context, CandidateSet.getLocation()); 3021 FunctionDecl *Specialization = 0; 3022 if (TemplateDeductionResult Result 3023 = DeduceTemplateArguments(FunctionTemplate, ExplicitTemplateArgs, 3024 Args, NumArgs, Specialization, Info)) { 3025 CandidateSet.push_back(OverloadCandidate()); 3026 OverloadCandidate &Candidate = CandidateSet.back(); 3027 Candidate.FoundDecl = FoundDecl; 3028 Candidate.Function = FunctionTemplate->getTemplatedDecl(); 3029 Candidate.Viable = false; 3030 Candidate.FailureKind = ovl_fail_bad_deduction; 3031 Candidate.IsSurrogate = false; 3032 Candidate.IgnoreObjectArgument = false; 3033 3034 // TODO: record more information about failed template arguments 3035 Candidate.DeductionFailure.Result = Result; 3036 Candidate.DeductionFailure.TemplateParameter = Info.Param.getOpaqueValue(); 3037 return; 3038 } 3039 3040 // Add the function template specialization produced by template argument 3041 // deduction as a candidate. 3042 assert(Specialization && "Missing function template specialization?"); 3043 AddOverloadCandidate(Specialization, FoundDecl, Args, NumArgs, CandidateSet, 3044 SuppressUserConversions, ForceRValue); 3045} 3046 3047/// AddConversionCandidate - Add a C++ conversion function as a 3048/// candidate in the candidate set (C++ [over.match.conv], 3049/// C++ [over.match.copy]). From is the expression we're converting from, 3050/// and ToType is the type that we're eventually trying to convert to 3051/// (which may or may not be the same type as the type that the 3052/// conversion function produces). 3053void 3054Sema::AddConversionCandidate(CXXConversionDecl *Conversion, 3055 DeclAccessPair FoundDecl, 3056 CXXRecordDecl *ActingContext, 3057 Expr *From, QualType ToType, 3058 OverloadCandidateSet& CandidateSet) { 3059 assert(!Conversion->getDescribedFunctionTemplate() && 3060 "Conversion function templates use AddTemplateConversionCandidate"); 3061 3062 if (!CandidateSet.isNewCandidate(Conversion)) 3063 return; 3064 3065 // Overload resolution is always an unevaluated context. 3066 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 3067 3068 // Add this candidate 3069 CandidateSet.push_back(OverloadCandidate()); 3070 OverloadCandidate& Candidate = CandidateSet.back(); 3071 Candidate.FoundDecl = FoundDecl; 3072 Candidate.Function = Conversion; 3073 Candidate.IsSurrogate = false; 3074 Candidate.IgnoreObjectArgument = false; 3075 Candidate.FinalConversion.setAsIdentityConversion(); 3076 Candidate.FinalConversion.setFromType(Conversion->getConversionType()); 3077 Candidate.FinalConversion.setAllToTypes(ToType); 3078 3079 // Determine the implicit conversion sequence for the implicit 3080 // object parameter. 3081 Candidate.Viable = true; 3082 Candidate.Conversions.resize(1); 3083 Candidate.Conversions[0] 3084 = TryObjectArgumentInitialization(From->getType(), Conversion, 3085 ActingContext); 3086 // Conversion functions to a different type in the base class is visible in 3087 // the derived class. So, a derived to base conversion should not participate 3088 // in overload resolution. 3089 if (Candidate.Conversions[0].Standard.Second == ICK_Derived_To_Base) 3090 Candidate.Conversions[0].Standard.Second = ICK_Identity; 3091 if (Candidate.Conversions[0].isBad()) { 3092 Candidate.Viable = false; 3093 Candidate.FailureKind = ovl_fail_bad_conversion; 3094 return; 3095 } 3096 3097 // We won't go through a user-define type conversion function to convert a 3098 // derived to base as such conversions are given Conversion Rank. They only 3099 // go through a copy constructor. 13.3.3.1.2-p4 [over.ics.user] 3100 QualType FromCanon 3101 = Context.getCanonicalType(From->getType().getUnqualifiedType()); 3102 QualType ToCanon = Context.getCanonicalType(ToType).getUnqualifiedType(); 3103 if (FromCanon == ToCanon || IsDerivedFrom(FromCanon, ToCanon)) { 3104 Candidate.Viable = false; 3105 Candidate.FailureKind = ovl_fail_trivial_conversion; 3106 return; 3107 } 3108 3109 3110 // To determine what the conversion from the result of calling the 3111 // conversion function to the type we're eventually trying to 3112 // convert to (ToType), we need to synthesize a call to the 3113 // conversion function and attempt copy initialization from it. This 3114 // makes sure that we get the right semantics with respect to 3115 // lvalues/rvalues and the type. Fortunately, we can allocate this 3116 // call on the stack and we don't need its arguments to be 3117 // well-formed. 3118 DeclRefExpr ConversionRef(Conversion, Conversion->getType(), 3119 From->getLocStart()); 3120 ImplicitCastExpr ConversionFn(Context.getPointerType(Conversion->getType()), 3121 CastExpr::CK_FunctionToPointerDecay, 3122 &ConversionRef, false); 3123 3124 // Note that it is safe to allocate CallExpr on the stack here because 3125 // there are 0 arguments (i.e., nothing is allocated using ASTContext's 3126 // allocator). 3127 CallExpr Call(Context, &ConversionFn, 0, 0, 3128 Conversion->getConversionType().getNonReferenceType(), 3129 From->getLocStart()); 3130 ImplicitConversionSequence ICS = 3131 TryCopyInitialization(&Call, ToType, 3132 /*SuppressUserConversions=*/true, 3133 /*ForceRValue=*/false, 3134 /*InOverloadResolution=*/false); 3135 3136 switch (ICS.getKind()) { 3137 case ImplicitConversionSequence::StandardConversion: 3138 Candidate.FinalConversion = ICS.Standard; 3139 3140 // C++ [over.ics.user]p3: 3141 // If the user-defined conversion is specified by a specialization of a 3142 // conversion function template, the second standard conversion sequence 3143 // shall have exact match rank. 3144 if (Conversion->getPrimaryTemplate() && 3145 GetConversionRank(ICS.Standard.Second) != ICR_Exact_Match) { 3146 Candidate.Viable = false; 3147 Candidate.FailureKind = ovl_fail_final_conversion_not_exact; 3148 } 3149 3150 break; 3151 3152 case ImplicitConversionSequence::BadConversion: 3153 Candidate.Viable = false; 3154 Candidate.FailureKind = ovl_fail_bad_final_conversion; 3155 break; 3156 3157 default: 3158 assert(false && 3159 "Can only end up with a standard conversion sequence or failure"); 3160 } 3161} 3162 3163/// \brief Adds a conversion function template specialization 3164/// candidate to the overload set, using template argument deduction 3165/// to deduce the template arguments of the conversion function 3166/// template from the type that we are converting to (C++ 3167/// [temp.deduct.conv]). 3168void 3169Sema::AddTemplateConversionCandidate(FunctionTemplateDecl *FunctionTemplate, 3170 DeclAccessPair FoundDecl, 3171 CXXRecordDecl *ActingDC, 3172 Expr *From, QualType ToType, 3173 OverloadCandidateSet &CandidateSet) { 3174 assert(isa<CXXConversionDecl>(FunctionTemplate->getTemplatedDecl()) && 3175 "Only conversion function templates permitted here"); 3176 3177 if (!CandidateSet.isNewCandidate(FunctionTemplate)) 3178 return; 3179 3180 TemplateDeductionInfo Info(Context, CandidateSet.getLocation()); 3181 CXXConversionDecl *Specialization = 0; 3182 if (TemplateDeductionResult Result 3183 = DeduceTemplateArguments(FunctionTemplate, ToType, 3184 Specialization, Info)) { 3185 // FIXME: Record what happened with template argument deduction, so 3186 // that we can give the user a beautiful diagnostic. 3187 (void)Result; 3188 return; 3189 } 3190 3191 // Add the conversion function template specialization produced by 3192 // template argument deduction as a candidate. 3193 assert(Specialization && "Missing function template specialization?"); 3194 AddConversionCandidate(Specialization, FoundDecl, ActingDC, From, ToType, 3195 CandidateSet); 3196} 3197 3198/// AddSurrogateCandidate - Adds a "surrogate" candidate function that 3199/// converts the given @c Object to a function pointer via the 3200/// conversion function @c Conversion, and then attempts to call it 3201/// with the given arguments (C++ [over.call.object]p2-4). Proto is 3202/// the type of function that we'll eventually be calling. 3203void Sema::AddSurrogateCandidate(CXXConversionDecl *Conversion, 3204 DeclAccessPair FoundDecl, 3205 CXXRecordDecl *ActingContext, 3206 const FunctionProtoType *Proto, 3207 QualType ObjectType, 3208 Expr **Args, unsigned NumArgs, 3209 OverloadCandidateSet& CandidateSet) { 3210 if (!CandidateSet.isNewCandidate(Conversion)) 3211 return; 3212 3213 // Overload resolution is always an unevaluated context. 3214 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 3215 3216 CandidateSet.push_back(OverloadCandidate()); 3217 OverloadCandidate& Candidate = CandidateSet.back(); 3218 Candidate.FoundDecl = FoundDecl; 3219 Candidate.Function = 0; 3220 Candidate.Surrogate = Conversion; 3221 Candidate.Viable = true; 3222 Candidate.IsSurrogate = true; 3223 Candidate.IgnoreObjectArgument = false; 3224 Candidate.Conversions.resize(NumArgs + 1); 3225 3226 // Determine the implicit conversion sequence for the implicit 3227 // object parameter. 3228 ImplicitConversionSequence ObjectInit 3229 = TryObjectArgumentInitialization(ObjectType, Conversion, ActingContext); 3230 if (ObjectInit.isBad()) { 3231 Candidate.Viable = false; 3232 Candidate.FailureKind = ovl_fail_bad_conversion; 3233 Candidate.Conversions[0] = ObjectInit; 3234 return; 3235 } 3236 3237 // The first conversion is actually a user-defined conversion whose 3238 // first conversion is ObjectInit's standard conversion (which is 3239 // effectively a reference binding). Record it as such. 3240 Candidate.Conversions[0].setUserDefined(); 3241 Candidate.Conversions[0].UserDefined.Before = ObjectInit.Standard; 3242 Candidate.Conversions[0].UserDefined.EllipsisConversion = false; 3243 Candidate.Conversions[0].UserDefined.ConversionFunction = Conversion; 3244 Candidate.Conversions[0].UserDefined.After 3245 = Candidate.Conversions[0].UserDefined.Before; 3246 Candidate.Conversions[0].UserDefined.After.setAsIdentityConversion(); 3247 3248 // Find the 3249 unsigned NumArgsInProto = Proto->getNumArgs(); 3250 3251 // (C++ 13.3.2p2): A candidate function having fewer than m 3252 // parameters is viable only if it has an ellipsis in its parameter 3253 // list (8.3.5). 3254 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 3255 Candidate.Viable = false; 3256 Candidate.FailureKind = ovl_fail_too_many_arguments; 3257 return; 3258 } 3259 3260 // Function types don't have any default arguments, so just check if 3261 // we have enough arguments. 3262 if (NumArgs < NumArgsInProto) { 3263 // Not enough arguments. 3264 Candidate.Viable = false; 3265 Candidate.FailureKind = ovl_fail_too_few_arguments; 3266 return; 3267 } 3268 3269 // Determine the implicit conversion sequences for each of the 3270 // arguments. 3271 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 3272 if (ArgIdx < NumArgsInProto) { 3273 // (C++ 13.3.2p3): for F to be a viable function, there shall 3274 // exist for each argument an implicit conversion sequence 3275 // (13.3.3.1) that converts that argument to the corresponding 3276 // parameter of F. 3277 QualType ParamType = Proto->getArgType(ArgIdx); 3278 Candidate.Conversions[ArgIdx + 1] 3279 = TryCopyInitialization(Args[ArgIdx], ParamType, 3280 /*SuppressUserConversions=*/false, 3281 /*ForceRValue=*/false, 3282 /*InOverloadResolution=*/false); 3283 if (Candidate.Conversions[ArgIdx + 1].isBad()) { 3284 Candidate.Viable = false; 3285 Candidate.FailureKind = ovl_fail_bad_conversion; 3286 break; 3287 } 3288 } else { 3289 // (C++ 13.3.2p2): For the purposes of overload resolution, any 3290 // argument for which there is no corresponding parameter is 3291 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 3292 Candidate.Conversions[ArgIdx + 1].setEllipsis(); 3293 } 3294 } 3295} 3296 3297// FIXME: This will eventually be removed, once we've migrated all of the 3298// operator overloading logic over to the scheme used by binary operators, which 3299// works for template instantiation. 3300void Sema::AddOperatorCandidates(OverloadedOperatorKind Op, Scope *S, 3301 SourceLocation OpLoc, 3302 Expr **Args, unsigned NumArgs, 3303 OverloadCandidateSet& CandidateSet, 3304 SourceRange OpRange) { 3305 UnresolvedSet<16> Fns; 3306 3307 QualType T1 = Args[0]->getType(); 3308 QualType T2; 3309 if (NumArgs > 1) 3310 T2 = Args[1]->getType(); 3311 3312 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 3313 if (S) 3314 LookupOverloadedOperatorName(Op, S, T1, T2, Fns); 3315 AddFunctionCandidates(Fns, Args, NumArgs, CandidateSet, false); 3316 AddArgumentDependentLookupCandidates(OpName, false, Args, NumArgs, 0, 3317 CandidateSet); 3318 AddMemberOperatorCandidates(Op, OpLoc, Args, NumArgs, CandidateSet, OpRange); 3319 AddBuiltinOperatorCandidates(Op, OpLoc, Args, NumArgs, CandidateSet); 3320} 3321 3322/// \brief Add overload candidates for overloaded operators that are 3323/// member functions. 3324/// 3325/// Add the overloaded operator candidates that are member functions 3326/// for the operator Op that was used in an operator expression such 3327/// as "x Op y". , Args/NumArgs provides the operator arguments, and 3328/// CandidateSet will store the added overload candidates. (C++ 3329/// [over.match.oper]). 3330void Sema::AddMemberOperatorCandidates(OverloadedOperatorKind Op, 3331 SourceLocation OpLoc, 3332 Expr **Args, unsigned NumArgs, 3333 OverloadCandidateSet& CandidateSet, 3334 SourceRange OpRange) { 3335 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 3336 3337 // C++ [over.match.oper]p3: 3338 // For a unary operator @ with an operand of a type whose 3339 // cv-unqualified version is T1, and for a binary operator @ with 3340 // a left operand of a type whose cv-unqualified version is T1 and 3341 // a right operand of a type whose cv-unqualified version is T2, 3342 // three sets of candidate functions, designated member 3343 // candidates, non-member candidates and built-in candidates, are 3344 // constructed as follows: 3345 QualType T1 = Args[0]->getType(); 3346 QualType T2; 3347 if (NumArgs > 1) 3348 T2 = Args[1]->getType(); 3349 3350 // -- If T1 is a class type, the set of member candidates is the 3351 // result of the qualified lookup of T1::operator@ 3352 // (13.3.1.1.1); otherwise, the set of member candidates is 3353 // empty. 3354 if (const RecordType *T1Rec = T1->getAs<RecordType>()) { 3355 // Complete the type if it can be completed. Otherwise, we're done. 3356 if (RequireCompleteType(OpLoc, T1, PDiag())) 3357 return; 3358 3359 LookupResult Operators(*this, OpName, OpLoc, LookupOrdinaryName); 3360 LookupQualifiedName(Operators, T1Rec->getDecl()); 3361 Operators.suppressDiagnostics(); 3362 3363 for (LookupResult::iterator Oper = Operators.begin(), 3364 OperEnd = Operators.end(); 3365 Oper != OperEnd; 3366 ++Oper) 3367 AddMethodCandidate(Oper.getPair(), Args[0]->getType(), 3368 Args + 1, NumArgs - 1, CandidateSet, 3369 /* SuppressUserConversions = */ false); 3370 } 3371} 3372 3373/// AddBuiltinCandidate - Add a candidate for a built-in 3374/// operator. ResultTy and ParamTys are the result and parameter types 3375/// of the built-in candidate, respectively. Args and NumArgs are the 3376/// arguments being passed to the candidate. IsAssignmentOperator 3377/// should be true when this built-in candidate is an assignment 3378/// operator. NumContextualBoolArguments is the number of arguments 3379/// (at the beginning of the argument list) that will be contextually 3380/// converted to bool. 3381void Sema::AddBuiltinCandidate(QualType ResultTy, QualType *ParamTys, 3382 Expr **Args, unsigned NumArgs, 3383 OverloadCandidateSet& CandidateSet, 3384 bool IsAssignmentOperator, 3385 unsigned NumContextualBoolArguments) { 3386 // Overload resolution is always an unevaluated context. 3387 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 3388 3389 // Add this candidate 3390 CandidateSet.push_back(OverloadCandidate()); 3391 OverloadCandidate& Candidate = CandidateSet.back(); 3392 Candidate.FoundDecl = DeclAccessPair::make(0, AS_none); 3393 Candidate.Function = 0; 3394 Candidate.IsSurrogate = false; 3395 Candidate.IgnoreObjectArgument = false; 3396 Candidate.BuiltinTypes.ResultTy = ResultTy; 3397 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 3398 Candidate.BuiltinTypes.ParamTypes[ArgIdx] = ParamTys[ArgIdx]; 3399 3400 // Determine the implicit conversion sequences for each of the 3401 // arguments. 3402 Candidate.Viable = true; 3403 Candidate.Conversions.resize(NumArgs); 3404 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 3405 // C++ [over.match.oper]p4: 3406 // For the built-in assignment operators, conversions of the 3407 // left operand are restricted as follows: 3408 // -- no temporaries are introduced to hold the left operand, and 3409 // -- no user-defined conversions are applied to the left 3410 // operand to achieve a type match with the left-most 3411 // parameter of a built-in candidate. 3412 // 3413 // We block these conversions by turning off user-defined 3414 // conversions, since that is the only way that initialization of 3415 // a reference to a non-class type can occur from something that 3416 // is not of the same type. 3417 if (ArgIdx < NumContextualBoolArguments) { 3418 assert(ParamTys[ArgIdx] == Context.BoolTy && 3419 "Contextual conversion to bool requires bool type"); 3420 Candidate.Conversions[ArgIdx] = TryContextuallyConvertToBool(Args[ArgIdx]); 3421 } else { 3422 Candidate.Conversions[ArgIdx] 3423 = TryCopyInitialization(Args[ArgIdx], ParamTys[ArgIdx], 3424 ArgIdx == 0 && IsAssignmentOperator, 3425 /*ForceRValue=*/false, 3426 /*InOverloadResolution=*/false); 3427 } 3428 if (Candidate.Conversions[ArgIdx].isBad()) { 3429 Candidate.Viable = false; 3430 Candidate.FailureKind = ovl_fail_bad_conversion; 3431 break; 3432 } 3433 } 3434} 3435 3436/// BuiltinCandidateTypeSet - A set of types that will be used for the 3437/// candidate operator functions for built-in operators (C++ 3438/// [over.built]). The types are separated into pointer types and 3439/// enumeration types. 3440class BuiltinCandidateTypeSet { 3441 /// TypeSet - A set of types. 3442 typedef llvm::SmallPtrSet<QualType, 8> TypeSet; 3443 3444 /// PointerTypes - The set of pointer types that will be used in the 3445 /// built-in candidates. 3446 TypeSet PointerTypes; 3447 3448 /// MemberPointerTypes - The set of member pointer types that will be 3449 /// used in the built-in candidates. 3450 TypeSet MemberPointerTypes; 3451 3452 /// EnumerationTypes - The set of enumeration types that will be 3453 /// used in the built-in candidates. 3454 TypeSet EnumerationTypes; 3455 3456 /// Sema - The semantic analysis instance where we are building the 3457 /// candidate type set. 3458 Sema &SemaRef; 3459 3460 /// Context - The AST context in which we will build the type sets. 3461 ASTContext &Context; 3462 3463 bool AddPointerWithMoreQualifiedTypeVariants(QualType Ty, 3464 const Qualifiers &VisibleQuals); 3465 bool AddMemberPointerWithMoreQualifiedTypeVariants(QualType Ty); 3466 3467public: 3468 /// iterator - Iterates through the types that are part of the set. 3469 typedef TypeSet::iterator iterator; 3470 3471 BuiltinCandidateTypeSet(Sema &SemaRef) 3472 : SemaRef(SemaRef), Context(SemaRef.Context) { } 3473 3474 void AddTypesConvertedFrom(QualType Ty, 3475 SourceLocation Loc, 3476 bool AllowUserConversions, 3477 bool AllowExplicitConversions, 3478 const Qualifiers &VisibleTypeConversionsQuals); 3479 3480 /// pointer_begin - First pointer type found; 3481 iterator pointer_begin() { return PointerTypes.begin(); } 3482 3483 /// pointer_end - Past the last pointer type found; 3484 iterator pointer_end() { return PointerTypes.end(); } 3485 3486 /// member_pointer_begin - First member pointer type found; 3487 iterator member_pointer_begin() { return MemberPointerTypes.begin(); } 3488 3489 /// member_pointer_end - Past the last member pointer type found; 3490 iterator member_pointer_end() { return MemberPointerTypes.end(); } 3491 3492 /// enumeration_begin - First enumeration type found; 3493 iterator enumeration_begin() { return EnumerationTypes.begin(); } 3494 3495 /// enumeration_end - Past the last enumeration type found; 3496 iterator enumeration_end() { return EnumerationTypes.end(); } 3497}; 3498 3499/// AddPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty to 3500/// the set of pointer types along with any more-qualified variants of 3501/// that type. For example, if @p Ty is "int const *", this routine 3502/// will add "int const *", "int const volatile *", "int const 3503/// restrict *", and "int const volatile restrict *" to the set of 3504/// pointer types. Returns true if the add of @p Ty itself succeeded, 3505/// false otherwise. 3506/// 3507/// FIXME: what to do about extended qualifiers? 3508bool 3509BuiltinCandidateTypeSet::AddPointerWithMoreQualifiedTypeVariants(QualType Ty, 3510 const Qualifiers &VisibleQuals) { 3511 3512 // Insert this type. 3513 if (!PointerTypes.insert(Ty)) 3514 return false; 3515 3516 const PointerType *PointerTy = Ty->getAs<PointerType>(); 3517 assert(PointerTy && "type was not a pointer type!"); 3518 3519 QualType PointeeTy = PointerTy->getPointeeType(); 3520 // Don't add qualified variants of arrays. For one, they're not allowed 3521 // (the qualifier would sink to the element type), and for another, the 3522 // only overload situation where it matters is subscript or pointer +- int, 3523 // and those shouldn't have qualifier variants anyway. 3524 if (PointeeTy->isArrayType()) 3525 return true; 3526 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 3527 if (const ConstantArrayType *Array =Context.getAsConstantArrayType(PointeeTy)) 3528 BaseCVR = Array->getElementType().getCVRQualifiers(); 3529 bool hasVolatile = VisibleQuals.hasVolatile(); 3530 bool hasRestrict = VisibleQuals.hasRestrict(); 3531 3532 // Iterate through all strict supersets of BaseCVR. 3533 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 3534 if ((CVR | BaseCVR) != CVR) continue; 3535 // Skip over Volatile/Restrict if no Volatile/Restrict found anywhere 3536 // in the types. 3537 if ((CVR & Qualifiers::Volatile) && !hasVolatile) continue; 3538 if ((CVR & Qualifiers::Restrict) && !hasRestrict) continue; 3539 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 3540 PointerTypes.insert(Context.getPointerType(QPointeeTy)); 3541 } 3542 3543 return true; 3544} 3545 3546/// AddMemberPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty 3547/// to the set of pointer types along with any more-qualified variants of 3548/// that type. For example, if @p Ty is "int const *", this routine 3549/// will add "int const *", "int const volatile *", "int const 3550/// restrict *", and "int const volatile restrict *" to the set of 3551/// pointer types. Returns true if the add of @p Ty itself succeeded, 3552/// false otherwise. 3553/// 3554/// FIXME: what to do about extended qualifiers? 3555bool 3556BuiltinCandidateTypeSet::AddMemberPointerWithMoreQualifiedTypeVariants( 3557 QualType Ty) { 3558 // Insert this type. 3559 if (!MemberPointerTypes.insert(Ty)) 3560 return false; 3561 3562 const MemberPointerType *PointerTy = Ty->getAs<MemberPointerType>(); 3563 assert(PointerTy && "type was not a member pointer type!"); 3564 3565 QualType PointeeTy = PointerTy->getPointeeType(); 3566 // Don't add qualified variants of arrays. For one, they're not allowed 3567 // (the qualifier would sink to the element type), and for another, the 3568 // only overload situation where it matters is subscript or pointer +- int, 3569 // and those shouldn't have qualifier variants anyway. 3570 if (PointeeTy->isArrayType()) 3571 return true; 3572 const Type *ClassTy = PointerTy->getClass(); 3573 3574 // Iterate through all strict supersets of the pointee type's CVR 3575 // qualifiers. 3576 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 3577 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 3578 if ((CVR | BaseCVR) != CVR) continue; 3579 3580 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 3581 MemberPointerTypes.insert(Context.getMemberPointerType(QPointeeTy, ClassTy)); 3582 } 3583 3584 return true; 3585} 3586 3587/// AddTypesConvertedFrom - Add each of the types to which the type @p 3588/// Ty can be implicit converted to the given set of @p Types. We're 3589/// primarily interested in pointer types and enumeration types. We also 3590/// take member pointer types, for the conditional operator. 3591/// AllowUserConversions is true if we should look at the conversion 3592/// functions of a class type, and AllowExplicitConversions if we 3593/// should also include the explicit conversion functions of a class 3594/// type. 3595void 3596BuiltinCandidateTypeSet::AddTypesConvertedFrom(QualType Ty, 3597 SourceLocation Loc, 3598 bool AllowUserConversions, 3599 bool AllowExplicitConversions, 3600 const Qualifiers &VisibleQuals) { 3601 // Only deal with canonical types. 3602 Ty = Context.getCanonicalType(Ty); 3603 3604 // Look through reference types; they aren't part of the type of an 3605 // expression for the purposes of conversions. 3606 if (const ReferenceType *RefTy = Ty->getAs<ReferenceType>()) 3607 Ty = RefTy->getPointeeType(); 3608 3609 // We don't care about qualifiers on the type. 3610 Ty = Ty.getLocalUnqualifiedType(); 3611 3612 // If we're dealing with an array type, decay to the pointer. 3613 if (Ty->isArrayType()) 3614 Ty = SemaRef.Context.getArrayDecayedType(Ty); 3615 3616 if (const PointerType *PointerTy = Ty->getAs<PointerType>()) { 3617 QualType PointeeTy = PointerTy->getPointeeType(); 3618 3619 // Insert our type, and its more-qualified variants, into the set 3620 // of types. 3621 if (!AddPointerWithMoreQualifiedTypeVariants(Ty, VisibleQuals)) 3622 return; 3623 } else if (Ty->isMemberPointerType()) { 3624 // Member pointers are far easier, since the pointee can't be converted. 3625 if (!AddMemberPointerWithMoreQualifiedTypeVariants(Ty)) 3626 return; 3627 } else if (Ty->isEnumeralType()) { 3628 EnumerationTypes.insert(Ty); 3629 } else if (AllowUserConversions) { 3630 if (const RecordType *TyRec = Ty->getAs<RecordType>()) { 3631 if (SemaRef.RequireCompleteType(Loc, Ty, 0)) { 3632 // No conversion functions in incomplete types. 3633 return; 3634 } 3635 3636 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 3637 const UnresolvedSetImpl *Conversions 3638 = ClassDecl->getVisibleConversionFunctions(); 3639 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 3640 E = Conversions->end(); I != E; ++I) { 3641 NamedDecl *D = I.getDecl(); 3642 if (isa<UsingShadowDecl>(D)) 3643 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 3644 3645 // Skip conversion function templates; they don't tell us anything 3646 // about which builtin types we can convert to. 3647 if (isa<FunctionTemplateDecl>(D)) 3648 continue; 3649 3650 CXXConversionDecl *Conv = cast<CXXConversionDecl>(D); 3651 if (AllowExplicitConversions || !Conv->isExplicit()) { 3652 AddTypesConvertedFrom(Conv->getConversionType(), Loc, false, false, 3653 VisibleQuals); 3654 } 3655 } 3656 } 3657 } 3658} 3659 3660/// \brief Helper function for AddBuiltinOperatorCandidates() that adds 3661/// the volatile- and non-volatile-qualified assignment operators for the 3662/// given type to the candidate set. 3663static void AddBuiltinAssignmentOperatorCandidates(Sema &S, 3664 QualType T, 3665 Expr **Args, 3666 unsigned NumArgs, 3667 OverloadCandidateSet &CandidateSet) { 3668 QualType ParamTypes[2]; 3669 3670 // T& operator=(T&, T) 3671 ParamTypes[0] = S.Context.getLValueReferenceType(T); 3672 ParamTypes[1] = T; 3673 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3674 /*IsAssignmentOperator=*/true); 3675 3676 if (!S.Context.getCanonicalType(T).isVolatileQualified()) { 3677 // volatile T& operator=(volatile T&, T) 3678 ParamTypes[0] 3679 = S.Context.getLValueReferenceType(S.Context.getVolatileType(T)); 3680 ParamTypes[1] = T; 3681 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3682 /*IsAssignmentOperator=*/true); 3683 } 3684} 3685 3686/// CollectVRQualifiers - This routine returns Volatile/Restrict qualifiers, 3687/// if any, found in visible type conversion functions found in ArgExpr's type. 3688static Qualifiers CollectVRQualifiers(ASTContext &Context, Expr* ArgExpr) { 3689 Qualifiers VRQuals; 3690 const RecordType *TyRec; 3691 if (const MemberPointerType *RHSMPType = 3692 ArgExpr->getType()->getAs<MemberPointerType>()) 3693 TyRec = cast<RecordType>(RHSMPType->getClass()); 3694 else 3695 TyRec = ArgExpr->getType()->getAs<RecordType>(); 3696 if (!TyRec) { 3697 // Just to be safe, assume the worst case. 3698 VRQuals.addVolatile(); 3699 VRQuals.addRestrict(); 3700 return VRQuals; 3701 } 3702 3703 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 3704 if (!ClassDecl->hasDefinition()) 3705 return VRQuals; 3706 3707 const UnresolvedSetImpl *Conversions = 3708 ClassDecl->getVisibleConversionFunctions(); 3709 3710 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 3711 E = Conversions->end(); I != E; ++I) { 3712 NamedDecl *D = I.getDecl(); 3713 if (isa<UsingShadowDecl>(D)) 3714 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 3715 if (CXXConversionDecl *Conv = dyn_cast<CXXConversionDecl>(D)) { 3716 QualType CanTy = Context.getCanonicalType(Conv->getConversionType()); 3717 if (const ReferenceType *ResTypeRef = CanTy->getAs<ReferenceType>()) 3718 CanTy = ResTypeRef->getPointeeType(); 3719 // Need to go down the pointer/mempointer chain and add qualifiers 3720 // as see them. 3721 bool done = false; 3722 while (!done) { 3723 if (const PointerType *ResTypePtr = CanTy->getAs<PointerType>()) 3724 CanTy = ResTypePtr->getPointeeType(); 3725 else if (const MemberPointerType *ResTypeMPtr = 3726 CanTy->getAs<MemberPointerType>()) 3727 CanTy = ResTypeMPtr->getPointeeType(); 3728 else 3729 done = true; 3730 if (CanTy.isVolatileQualified()) 3731 VRQuals.addVolatile(); 3732 if (CanTy.isRestrictQualified()) 3733 VRQuals.addRestrict(); 3734 if (VRQuals.hasRestrict() && VRQuals.hasVolatile()) 3735 return VRQuals; 3736 } 3737 } 3738 } 3739 return VRQuals; 3740} 3741 3742/// AddBuiltinOperatorCandidates - Add the appropriate built-in 3743/// operator overloads to the candidate set (C++ [over.built]), based 3744/// on the operator @p Op and the arguments given. For example, if the 3745/// operator is a binary '+', this routine might add "int 3746/// operator+(int, int)" to cover integer addition. 3747void 3748Sema::AddBuiltinOperatorCandidates(OverloadedOperatorKind Op, 3749 SourceLocation OpLoc, 3750 Expr **Args, unsigned NumArgs, 3751 OverloadCandidateSet& CandidateSet) { 3752 // The set of "promoted arithmetic types", which are the arithmetic 3753 // types are that preserved by promotion (C++ [over.built]p2). Note 3754 // that the first few of these types are the promoted integral 3755 // types; these types need to be first. 3756 // FIXME: What about complex? 3757 const unsigned FirstIntegralType = 0; 3758 const unsigned LastIntegralType = 13; 3759 const unsigned FirstPromotedIntegralType = 7, 3760 LastPromotedIntegralType = 13; 3761 const unsigned FirstPromotedArithmeticType = 7, 3762 LastPromotedArithmeticType = 16; 3763 const unsigned NumArithmeticTypes = 16; 3764 QualType ArithmeticTypes[NumArithmeticTypes] = { 3765 Context.BoolTy, Context.CharTy, Context.WCharTy, 3766// FIXME: Context.Char16Ty, Context.Char32Ty, 3767 Context.SignedCharTy, Context.ShortTy, 3768 Context.UnsignedCharTy, Context.UnsignedShortTy, 3769 Context.IntTy, Context.LongTy, Context.LongLongTy, 3770 Context.UnsignedIntTy, Context.UnsignedLongTy, Context.UnsignedLongLongTy, 3771 Context.FloatTy, Context.DoubleTy, Context.LongDoubleTy 3772 }; 3773 assert(ArithmeticTypes[FirstPromotedIntegralType] == Context.IntTy && 3774 "Invalid first promoted integral type"); 3775 assert(ArithmeticTypes[LastPromotedIntegralType - 1] 3776 == Context.UnsignedLongLongTy && 3777 "Invalid last promoted integral type"); 3778 assert(ArithmeticTypes[FirstPromotedArithmeticType] == Context.IntTy && 3779 "Invalid first promoted arithmetic type"); 3780 assert(ArithmeticTypes[LastPromotedArithmeticType - 1] 3781 == Context.LongDoubleTy && 3782 "Invalid last promoted arithmetic type"); 3783 3784 // Find all of the types that the arguments can convert to, but only 3785 // if the operator we're looking at has built-in operator candidates 3786 // that make use of these types. 3787 Qualifiers VisibleTypeConversionsQuals; 3788 VisibleTypeConversionsQuals.addConst(); 3789 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 3790 VisibleTypeConversionsQuals += CollectVRQualifiers(Context, Args[ArgIdx]); 3791 3792 BuiltinCandidateTypeSet CandidateTypes(*this); 3793 if (Op == OO_Less || Op == OO_Greater || Op == OO_LessEqual || 3794 Op == OO_GreaterEqual || Op == OO_EqualEqual || Op == OO_ExclaimEqual || 3795 Op == OO_Plus || (Op == OO_Minus && NumArgs == 2) || Op == OO_Equal || 3796 Op == OO_PlusEqual || Op == OO_MinusEqual || Op == OO_Subscript || 3797 Op == OO_ArrowStar || Op == OO_PlusPlus || Op == OO_MinusMinus || 3798 (Op == OO_Star && NumArgs == 1) || Op == OO_Conditional) { 3799 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 3800 CandidateTypes.AddTypesConvertedFrom(Args[ArgIdx]->getType(), 3801 OpLoc, 3802 true, 3803 (Op == OO_Exclaim || 3804 Op == OO_AmpAmp || 3805 Op == OO_PipePipe), 3806 VisibleTypeConversionsQuals); 3807 } 3808 3809 bool isComparison = false; 3810 switch (Op) { 3811 case OO_None: 3812 case NUM_OVERLOADED_OPERATORS: 3813 assert(false && "Expected an overloaded operator"); 3814 break; 3815 3816 case OO_Star: // '*' is either unary or binary 3817 if (NumArgs == 1) 3818 goto UnaryStar; 3819 else 3820 goto BinaryStar; 3821 break; 3822 3823 case OO_Plus: // '+' is either unary or binary 3824 if (NumArgs == 1) 3825 goto UnaryPlus; 3826 else 3827 goto BinaryPlus; 3828 break; 3829 3830 case OO_Minus: // '-' is either unary or binary 3831 if (NumArgs == 1) 3832 goto UnaryMinus; 3833 else 3834 goto BinaryMinus; 3835 break; 3836 3837 case OO_Amp: // '&' is either unary or binary 3838 if (NumArgs == 1) 3839 goto UnaryAmp; 3840 else 3841 goto BinaryAmp; 3842 3843 case OO_PlusPlus: 3844 case OO_MinusMinus: 3845 // C++ [over.built]p3: 3846 // 3847 // For every pair (T, VQ), where T is an arithmetic type, and VQ 3848 // is either volatile or empty, there exist candidate operator 3849 // functions of the form 3850 // 3851 // VQ T& operator++(VQ T&); 3852 // T operator++(VQ T&, int); 3853 // 3854 // C++ [over.built]p4: 3855 // 3856 // For every pair (T, VQ), where T is an arithmetic type other 3857 // than bool, and VQ is either volatile or empty, there exist 3858 // candidate operator functions of the form 3859 // 3860 // VQ T& operator--(VQ T&); 3861 // T operator--(VQ T&, int); 3862 for (unsigned Arith = (Op == OO_PlusPlus? 0 : 1); 3863 Arith < NumArithmeticTypes; ++Arith) { 3864 QualType ArithTy = ArithmeticTypes[Arith]; 3865 QualType ParamTypes[2] 3866 = { Context.getLValueReferenceType(ArithTy), Context.IntTy }; 3867 3868 // Non-volatile version. 3869 if (NumArgs == 1) 3870 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3871 else 3872 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 3873 // heuristic to reduce number of builtin candidates in the set. 3874 // Add volatile version only if there are conversions to a volatile type. 3875 if (VisibleTypeConversionsQuals.hasVolatile()) { 3876 // Volatile version 3877 ParamTypes[0] 3878 = Context.getLValueReferenceType(Context.getVolatileType(ArithTy)); 3879 if (NumArgs == 1) 3880 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3881 else 3882 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 3883 } 3884 } 3885 3886 // C++ [over.built]p5: 3887 // 3888 // For every pair (T, VQ), where T is a cv-qualified or 3889 // cv-unqualified object type, and VQ is either volatile or 3890 // empty, there exist candidate operator functions of the form 3891 // 3892 // T*VQ& operator++(T*VQ&); 3893 // T*VQ& operator--(T*VQ&); 3894 // T* operator++(T*VQ&, int); 3895 // T* operator--(T*VQ&, int); 3896 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3897 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3898 // Skip pointer types that aren't pointers to object types. 3899 if (!(*Ptr)->getAs<PointerType>()->getPointeeType()->isObjectType()) 3900 continue; 3901 3902 QualType ParamTypes[2] = { 3903 Context.getLValueReferenceType(*Ptr), Context.IntTy 3904 }; 3905 3906 // Without volatile 3907 if (NumArgs == 1) 3908 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3909 else 3910 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3911 3912 if (!Context.getCanonicalType(*Ptr).isVolatileQualified() && 3913 VisibleTypeConversionsQuals.hasVolatile()) { 3914 // With volatile 3915 ParamTypes[0] 3916 = Context.getLValueReferenceType(Context.getVolatileType(*Ptr)); 3917 if (NumArgs == 1) 3918 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3919 else 3920 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3921 } 3922 } 3923 break; 3924 3925 UnaryStar: 3926 // C++ [over.built]p6: 3927 // For every cv-qualified or cv-unqualified object type T, there 3928 // exist candidate operator functions of the form 3929 // 3930 // T& operator*(T*); 3931 // 3932 // C++ [over.built]p7: 3933 // For every function type T, there exist candidate operator 3934 // functions of the form 3935 // T& operator*(T*); 3936 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3937 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3938 QualType ParamTy = *Ptr; 3939 QualType PointeeTy = ParamTy->getAs<PointerType>()->getPointeeType(); 3940 AddBuiltinCandidate(Context.getLValueReferenceType(PointeeTy), 3941 &ParamTy, Args, 1, CandidateSet); 3942 } 3943 break; 3944 3945 UnaryPlus: 3946 // C++ [over.built]p8: 3947 // For every type T, there exist candidate operator functions of 3948 // the form 3949 // 3950 // T* operator+(T*); 3951 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3952 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3953 QualType ParamTy = *Ptr; 3954 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet); 3955 } 3956 3957 // Fall through 3958 3959 UnaryMinus: 3960 // C++ [over.built]p9: 3961 // For every promoted arithmetic type T, there exist candidate 3962 // operator functions of the form 3963 // 3964 // T operator+(T); 3965 // T operator-(T); 3966 for (unsigned Arith = FirstPromotedArithmeticType; 3967 Arith < LastPromotedArithmeticType; ++Arith) { 3968 QualType ArithTy = ArithmeticTypes[Arith]; 3969 AddBuiltinCandidate(ArithTy, &ArithTy, Args, 1, CandidateSet); 3970 } 3971 break; 3972 3973 case OO_Tilde: 3974 // C++ [over.built]p10: 3975 // For every promoted integral type T, there exist candidate 3976 // operator functions of the form 3977 // 3978 // T operator~(T); 3979 for (unsigned Int = FirstPromotedIntegralType; 3980 Int < LastPromotedIntegralType; ++Int) { 3981 QualType IntTy = ArithmeticTypes[Int]; 3982 AddBuiltinCandidate(IntTy, &IntTy, Args, 1, CandidateSet); 3983 } 3984 break; 3985 3986 case OO_New: 3987 case OO_Delete: 3988 case OO_Array_New: 3989 case OO_Array_Delete: 3990 case OO_Call: 3991 assert(false && "Special operators don't use AddBuiltinOperatorCandidates"); 3992 break; 3993 3994 case OO_Comma: 3995 UnaryAmp: 3996 case OO_Arrow: 3997 // C++ [over.match.oper]p3: 3998 // -- For the operator ',', the unary operator '&', or the 3999 // operator '->', the built-in candidates set is empty. 4000 break; 4001 4002 case OO_EqualEqual: 4003 case OO_ExclaimEqual: 4004 // C++ [over.match.oper]p16: 4005 // For every pointer to member type T, there exist candidate operator 4006 // functions of the form 4007 // 4008 // bool operator==(T,T); 4009 // bool operator!=(T,T); 4010 for (BuiltinCandidateTypeSet::iterator 4011 MemPtr = CandidateTypes.member_pointer_begin(), 4012 MemPtrEnd = CandidateTypes.member_pointer_end(); 4013 MemPtr != MemPtrEnd; 4014 ++MemPtr) { 4015 QualType ParamTypes[2] = { *MemPtr, *MemPtr }; 4016 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 4017 } 4018 4019 // Fall through 4020 4021 case OO_Less: 4022 case OO_Greater: 4023 case OO_LessEqual: 4024 case OO_GreaterEqual: 4025 // C++ [over.built]p15: 4026 // 4027 // For every pointer or enumeration type T, there exist 4028 // candidate operator functions of the form 4029 // 4030 // bool operator<(T, T); 4031 // bool operator>(T, T); 4032 // bool operator<=(T, T); 4033 // bool operator>=(T, T); 4034 // bool operator==(T, T); 4035 // bool operator!=(T, T); 4036 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 4037 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4038 QualType ParamTypes[2] = { *Ptr, *Ptr }; 4039 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 4040 } 4041 for (BuiltinCandidateTypeSet::iterator Enum 4042 = CandidateTypes.enumeration_begin(); 4043 Enum != CandidateTypes.enumeration_end(); ++Enum) { 4044 QualType ParamTypes[2] = { *Enum, *Enum }; 4045 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 4046 } 4047 4048 // Fall through. 4049 isComparison = true; 4050 4051 BinaryPlus: 4052 BinaryMinus: 4053 if (!isComparison) { 4054 // We didn't fall through, so we must have OO_Plus or OO_Minus. 4055 4056 // C++ [over.built]p13: 4057 // 4058 // For every cv-qualified or cv-unqualified object type T 4059 // there exist candidate operator functions of the form 4060 // 4061 // T* operator+(T*, ptrdiff_t); 4062 // T& operator[](T*, ptrdiff_t); [BELOW] 4063 // T* operator-(T*, ptrdiff_t); 4064 // T* operator+(ptrdiff_t, T*); 4065 // T& operator[](ptrdiff_t, T*); [BELOW] 4066 // 4067 // C++ [over.built]p14: 4068 // 4069 // For every T, where T is a pointer to object type, there 4070 // exist candidate operator functions of the form 4071 // 4072 // ptrdiff_t operator-(T, T); 4073 for (BuiltinCandidateTypeSet::iterator Ptr 4074 = CandidateTypes.pointer_begin(); 4075 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4076 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 4077 4078 // operator+(T*, ptrdiff_t) or operator-(T*, ptrdiff_t) 4079 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 4080 4081 if (Op == OO_Plus) { 4082 // T* operator+(ptrdiff_t, T*); 4083 ParamTypes[0] = ParamTypes[1]; 4084 ParamTypes[1] = *Ptr; 4085 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 4086 } else { 4087 // ptrdiff_t operator-(T, T); 4088 ParamTypes[1] = *Ptr; 4089 AddBuiltinCandidate(Context.getPointerDiffType(), ParamTypes, 4090 Args, 2, CandidateSet); 4091 } 4092 } 4093 } 4094 // Fall through 4095 4096 case OO_Slash: 4097 BinaryStar: 4098 Conditional: 4099 // C++ [over.built]p12: 4100 // 4101 // For every pair of promoted arithmetic types L and R, there 4102 // exist candidate operator functions of the form 4103 // 4104 // LR operator*(L, R); 4105 // LR operator/(L, R); 4106 // LR operator+(L, R); 4107 // LR operator-(L, R); 4108 // bool operator<(L, R); 4109 // bool operator>(L, R); 4110 // bool operator<=(L, R); 4111 // bool operator>=(L, R); 4112 // bool operator==(L, R); 4113 // bool operator!=(L, R); 4114 // 4115 // where LR is the result of the usual arithmetic conversions 4116 // between types L and R. 4117 // 4118 // C++ [over.built]p24: 4119 // 4120 // For every pair of promoted arithmetic types L and R, there exist 4121 // candidate operator functions of the form 4122 // 4123 // LR operator?(bool, L, R); 4124 // 4125 // where LR is the result of the usual arithmetic conversions 4126 // between types L and R. 4127 // Our candidates ignore the first parameter. 4128 for (unsigned Left = FirstPromotedArithmeticType; 4129 Left < LastPromotedArithmeticType; ++Left) { 4130 for (unsigned Right = FirstPromotedArithmeticType; 4131 Right < LastPromotedArithmeticType; ++Right) { 4132 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 4133 QualType Result 4134 = isComparison 4135 ? Context.BoolTy 4136 : Context.UsualArithmeticConversionsType(LandR[0], LandR[1]); 4137 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 4138 } 4139 } 4140 break; 4141 4142 case OO_Percent: 4143 BinaryAmp: 4144 case OO_Caret: 4145 case OO_Pipe: 4146 case OO_LessLess: 4147 case OO_GreaterGreater: 4148 // C++ [over.built]p17: 4149 // 4150 // For every pair of promoted integral types L and R, there 4151 // exist candidate operator functions of the form 4152 // 4153 // LR operator%(L, R); 4154 // LR operator&(L, R); 4155 // LR operator^(L, R); 4156 // LR operator|(L, R); 4157 // L operator<<(L, R); 4158 // L operator>>(L, R); 4159 // 4160 // where LR is the result of the usual arithmetic conversions 4161 // between types L and R. 4162 for (unsigned Left = FirstPromotedIntegralType; 4163 Left < LastPromotedIntegralType; ++Left) { 4164 for (unsigned Right = FirstPromotedIntegralType; 4165 Right < LastPromotedIntegralType; ++Right) { 4166 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 4167 QualType Result = (Op == OO_LessLess || Op == OO_GreaterGreater) 4168 ? LandR[0] 4169 : Context.UsualArithmeticConversionsType(LandR[0], LandR[1]); 4170 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 4171 } 4172 } 4173 break; 4174 4175 case OO_Equal: 4176 // C++ [over.built]p20: 4177 // 4178 // For every pair (T, VQ), where T is an enumeration or 4179 // pointer to member type and VQ is either volatile or 4180 // empty, there exist candidate operator functions of the form 4181 // 4182 // VQ T& operator=(VQ T&, T); 4183 for (BuiltinCandidateTypeSet::iterator 4184 Enum = CandidateTypes.enumeration_begin(), 4185 EnumEnd = CandidateTypes.enumeration_end(); 4186 Enum != EnumEnd; ++Enum) 4187 AddBuiltinAssignmentOperatorCandidates(*this, *Enum, Args, 2, 4188 CandidateSet); 4189 for (BuiltinCandidateTypeSet::iterator 4190 MemPtr = CandidateTypes.member_pointer_begin(), 4191 MemPtrEnd = CandidateTypes.member_pointer_end(); 4192 MemPtr != MemPtrEnd; ++MemPtr) 4193 AddBuiltinAssignmentOperatorCandidates(*this, *MemPtr, Args, 2, 4194 CandidateSet); 4195 // Fall through. 4196 4197 case OO_PlusEqual: 4198 case OO_MinusEqual: 4199 // C++ [over.built]p19: 4200 // 4201 // For every pair (T, VQ), where T is any type and VQ is either 4202 // volatile or empty, there exist candidate operator functions 4203 // of the form 4204 // 4205 // T*VQ& operator=(T*VQ&, T*); 4206 // 4207 // C++ [over.built]p21: 4208 // 4209 // For every pair (T, VQ), where T is a cv-qualified or 4210 // cv-unqualified object type and VQ is either volatile or 4211 // empty, there exist candidate operator functions of the form 4212 // 4213 // T*VQ& operator+=(T*VQ&, ptrdiff_t); 4214 // T*VQ& operator-=(T*VQ&, ptrdiff_t); 4215 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 4216 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4217 QualType ParamTypes[2]; 4218 ParamTypes[1] = (Op == OO_Equal)? *Ptr : Context.getPointerDiffType(); 4219 4220 // non-volatile version 4221 ParamTypes[0] = Context.getLValueReferenceType(*Ptr); 4222 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4223 /*IsAssigmentOperator=*/Op == OO_Equal); 4224 4225 if (!Context.getCanonicalType(*Ptr).isVolatileQualified() && 4226 VisibleTypeConversionsQuals.hasVolatile()) { 4227 // volatile version 4228 ParamTypes[0] 4229 = Context.getLValueReferenceType(Context.getVolatileType(*Ptr)); 4230 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4231 /*IsAssigmentOperator=*/Op == OO_Equal); 4232 } 4233 } 4234 // Fall through. 4235 4236 case OO_StarEqual: 4237 case OO_SlashEqual: 4238 // C++ [over.built]p18: 4239 // 4240 // For every triple (L, VQ, R), where L is an arithmetic type, 4241 // VQ is either volatile or empty, and R is a promoted 4242 // arithmetic type, there exist candidate operator functions of 4243 // the form 4244 // 4245 // VQ L& operator=(VQ L&, R); 4246 // VQ L& operator*=(VQ L&, R); 4247 // VQ L& operator/=(VQ L&, R); 4248 // VQ L& operator+=(VQ L&, R); 4249 // VQ L& operator-=(VQ L&, R); 4250 for (unsigned Left = 0; Left < NumArithmeticTypes; ++Left) { 4251 for (unsigned Right = FirstPromotedArithmeticType; 4252 Right < LastPromotedArithmeticType; ++Right) { 4253 QualType ParamTypes[2]; 4254 ParamTypes[1] = ArithmeticTypes[Right]; 4255 4256 // Add this built-in operator as a candidate (VQ is empty). 4257 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 4258 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4259 /*IsAssigmentOperator=*/Op == OO_Equal); 4260 4261 // Add this built-in operator as a candidate (VQ is 'volatile'). 4262 if (VisibleTypeConversionsQuals.hasVolatile()) { 4263 ParamTypes[0] = Context.getVolatileType(ArithmeticTypes[Left]); 4264 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 4265 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4266 /*IsAssigmentOperator=*/Op == OO_Equal); 4267 } 4268 } 4269 } 4270 break; 4271 4272 case OO_PercentEqual: 4273 case OO_LessLessEqual: 4274 case OO_GreaterGreaterEqual: 4275 case OO_AmpEqual: 4276 case OO_CaretEqual: 4277 case OO_PipeEqual: 4278 // C++ [over.built]p22: 4279 // 4280 // For every triple (L, VQ, R), where L is an integral type, VQ 4281 // is either volatile or empty, and R is a promoted integral 4282 // type, there exist candidate operator functions of the form 4283 // 4284 // VQ L& operator%=(VQ L&, R); 4285 // VQ L& operator<<=(VQ L&, R); 4286 // VQ L& operator>>=(VQ L&, R); 4287 // VQ L& operator&=(VQ L&, R); 4288 // VQ L& operator^=(VQ L&, R); 4289 // VQ L& operator|=(VQ L&, R); 4290 for (unsigned Left = FirstIntegralType; Left < LastIntegralType; ++Left) { 4291 for (unsigned Right = FirstPromotedIntegralType; 4292 Right < LastPromotedIntegralType; ++Right) { 4293 QualType ParamTypes[2]; 4294 ParamTypes[1] = ArithmeticTypes[Right]; 4295 4296 // Add this built-in operator as a candidate (VQ is empty). 4297 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 4298 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 4299 if (VisibleTypeConversionsQuals.hasVolatile()) { 4300 // Add this built-in operator as a candidate (VQ is 'volatile'). 4301 ParamTypes[0] = ArithmeticTypes[Left]; 4302 ParamTypes[0] = Context.getVolatileType(ParamTypes[0]); 4303 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 4304 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 4305 } 4306 } 4307 } 4308 break; 4309 4310 case OO_Exclaim: { 4311 // C++ [over.operator]p23: 4312 // 4313 // There also exist candidate operator functions of the form 4314 // 4315 // bool operator!(bool); 4316 // bool operator&&(bool, bool); [BELOW] 4317 // bool operator||(bool, bool); [BELOW] 4318 QualType ParamTy = Context.BoolTy; 4319 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet, 4320 /*IsAssignmentOperator=*/false, 4321 /*NumContextualBoolArguments=*/1); 4322 break; 4323 } 4324 4325 case OO_AmpAmp: 4326 case OO_PipePipe: { 4327 // C++ [over.operator]p23: 4328 // 4329 // There also exist candidate operator functions of the form 4330 // 4331 // bool operator!(bool); [ABOVE] 4332 // bool operator&&(bool, bool); 4333 // bool operator||(bool, bool); 4334 QualType ParamTypes[2] = { Context.BoolTy, Context.BoolTy }; 4335 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet, 4336 /*IsAssignmentOperator=*/false, 4337 /*NumContextualBoolArguments=*/2); 4338 break; 4339 } 4340 4341 case OO_Subscript: 4342 // C++ [over.built]p13: 4343 // 4344 // For every cv-qualified or cv-unqualified object type T there 4345 // exist candidate operator functions of the form 4346 // 4347 // T* operator+(T*, ptrdiff_t); [ABOVE] 4348 // T& operator[](T*, ptrdiff_t); 4349 // T* operator-(T*, ptrdiff_t); [ABOVE] 4350 // T* operator+(ptrdiff_t, T*); [ABOVE] 4351 // T& operator[](ptrdiff_t, T*); 4352 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 4353 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4354 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 4355 QualType PointeeType = (*Ptr)->getAs<PointerType>()->getPointeeType(); 4356 QualType ResultTy = Context.getLValueReferenceType(PointeeType); 4357 4358 // T& operator[](T*, ptrdiff_t) 4359 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 4360 4361 // T& operator[](ptrdiff_t, T*); 4362 ParamTypes[0] = ParamTypes[1]; 4363 ParamTypes[1] = *Ptr; 4364 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 4365 } 4366 break; 4367 4368 case OO_ArrowStar: 4369 // C++ [over.built]p11: 4370 // For every quintuple (C1, C2, T, CV1, CV2), where C2 is a class type, 4371 // C1 is the same type as C2 or is a derived class of C2, T is an object 4372 // type or a function type, and CV1 and CV2 are cv-qualifier-seqs, 4373 // there exist candidate operator functions of the form 4374 // CV12 T& operator->*(CV1 C1*, CV2 T C2::*); 4375 // where CV12 is the union of CV1 and CV2. 4376 { 4377 for (BuiltinCandidateTypeSet::iterator Ptr = 4378 CandidateTypes.pointer_begin(); 4379 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4380 QualType C1Ty = (*Ptr); 4381 QualType C1; 4382 QualifierCollector Q1; 4383 if (const PointerType *PointerTy = C1Ty->getAs<PointerType>()) { 4384 C1 = QualType(Q1.strip(PointerTy->getPointeeType()), 0); 4385 if (!isa<RecordType>(C1)) 4386 continue; 4387 // heuristic to reduce number of builtin candidates in the set. 4388 // Add volatile/restrict version only if there are conversions to a 4389 // volatile/restrict type. 4390 if (!VisibleTypeConversionsQuals.hasVolatile() && Q1.hasVolatile()) 4391 continue; 4392 if (!VisibleTypeConversionsQuals.hasRestrict() && Q1.hasRestrict()) 4393 continue; 4394 } 4395 for (BuiltinCandidateTypeSet::iterator 4396 MemPtr = CandidateTypes.member_pointer_begin(), 4397 MemPtrEnd = CandidateTypes.member_pointer_end(); 4398 MemPtr != MemPtrEnd; ++MemPtr) { 4399 const MemberPointerType *mptr = cast<MemberPointerType>(*MemPtr); 4400 QualType C2 = QualType(mptr->getClass(), 0); 4401 C2 = C2.getUnqualifiedType(); 4402 if (C1 != C2 && !IsDerivedFrom(C1, C2)) 4403 break; 4404 QualType ParamTypes[2] = { *Ptr, *MemPtr }; 4405 // build CV12 T& 4406 QualType T = mptr->getPointeeType(); 4407 if (!VisibleTypeConversionsQuals.hasVolatile() && 4408 T.isVolatileQualified()) 4409 continue; 4410 if (!VisibleTypeConversionsQuals.hasRestrict() && 4411 T.isRestrictQualified()) 4412 continue; 4413 T = Q1.apply(T); 4414 QualType ResultTy = Context.getLValueReferenceType(T); 4415 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 4416 } 4417 } 4418 } 4419 break; 4420 4421 case OO_Conditional: 4422 // Note that we don't consider the first argument, since it has been 4423 // contextually converted to bool long ago. The candidates below are 4424 // therefore added as binary. 4425 // 4426 // C++ [over.built]p24: 4427 // For every type T, where T is a pointer or pointer-to-member type, 4428 // there exist candidate operator functions of the form 4429 // 4430 // T operator?(bool, T, T); 4431 // 4432 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(), 4433 E = CandidateTypes.pointer_end(); Ptr != E; ++Ptr) { 4434 QualType ParamTypes[2] = { *Ptr, *Ptr }; 4435 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 4436 } 4437 for (BuiltinCandidateTypeSet::iterator Ptr = 4438 CandidateTypes.member_pointer_begin(), 4439 E = CandidateTypes.member_pointer_end(); Ptr != E; ++Ptr) { 4440 QualType ParamTypes[2] = { *Ptr, *Ptr }; 4441 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 4442 } 4443 goto Conditional; 4444 } 4445} 4446 4447/// \brief Add function candidates found via argument-dependent lookup 4448/// to the set of overloading candidates. 4449/// 4450/// This routine performs argument-dependent name lookup based on the 4451/// given function name (which may also be an operator name) and adds 4452/// all of the overload candidates found by ADL to the overload 4453/// candidate set (C++ [basic.lookup.argdep]). 4454void 4455Sema::AddArgumentDependentLookupCandidates(DeclarationName Name, 4456 bool Operator, 4457 Expr **Args, unsigned NumArgs, 4458 const TemplateArgumentListInfo *ExplicitTemplateArgs, 4459 OverloadCandidateSet& CandidateSet, 4460 bool PartialOverloading) { 4461 ADLResult Fns; 4462 4463 // FIXME: This approach for uniquing ADL results (and removing 4464 // redundant candidates from the set) relies on pointer-equality, 4465 // which means we need to key off the canonical decl. However, 4466 // always going back to the canonical decl might not get us the 4467 // right set of default arguments. What default arguments are 4468 // we supposed to consider on ADL candidates, anyway? 4469 4470 // FIXME: Pass in the explicit template arguments? 4471 ArgumentDependentLookup(Name, Operator, Args, NumArgs, Fns); 4472 4473 // Erase all of the candidates we already knew about. 4474 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 4475 CandEnd = CandidateSet.end(); 4476 Cand != CandEnd; ++Cand) 4477 if (Cand->Function) { 4478 Fns.erase(Cand->Function); 4479 if (FunctionTemplateDecl *FunTmpl = Cand->Function->getPrimaryTemplate()) 4480 Fns.erase(FunTmpl); 4481 } 4482 4483 // For each of the ADL candidates we found, add it to the overload 4484 // set. 4485 for (ADLResult::iterator I = Fns.begin(), E = Fns.end(); I != E; ++I) { 4486 DeclAccessPair FoundDecl = DeclAccessPair::make(*I, AS_none); 4487 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*I)) { 4488 if (ExplicitTemplateArgs) 4489 continue; 4490 4491 AddOverloadCandidate(FD, FoundDecl, Args, NumArgs, CandidateSet, 4492 false, false, PartialOverloading); 4493 } else 4494 AddTemplateOverloadCandidate(cast<FunctionTemplateDecl>(*I), 4495 FoundDecl, ExplicitTemplateArgs, 4496 Args, NumArgs, CandidateSet); 4497 } 4498} 4499 4500/// isBetterOverloadCandidate - Determines whether the first overload 4501/// candidate is a better candidate than the second (C++ 13.3.3p1). 4502bool 4503Sema::isBetterOverloadCandidate(const OverloadCandidate& Cand1, 4504 const OverloadCandidate& Cand2, 4505 SourceLocation Loc) { 4506 // Define viable functions to be better candidates than non-viable 4507 // functions. 4508 if (!Cand2.Viable) 4509 return Cand1.Viable; 4510 else if (!Cand1.Viable) 4511 return false; 4512 4513 // C++ [over.match.best]p1: 4514 // 4515 // -- if F is a static member function, ICS1(F) is defined such 4516 // that ICS1(F) is neither better nor worse than ICS1(G) for 4517 // any function G, and, symmetrically, ICS1(G) is neither 4518 // better nor worse than ICS1(F). 4519 unsigned StartArg = 0; 4520 if (Cand1.IgnoreObjectArgument || Cand2.IgnoreObjectArgument) 4521 StartArg = 1; 4522 4523 // C++ [over.match.best]p1: 4524 // A viable function F1 is defined to be a better function than another 4525 // viable function F2 if for all arguments i, ICSi(F1) is not a worse 4526 // conversion sequence than ICSi(F2), and then... 4527 unsigned NumArgs = Cand1.Conversions.size(); 4528 assert(Cand2.Conversions.size() == NumArgs && "Overload candidate mismatch"); 4529 bool HasBetterConversion = false; 4530 for (unsigned ArgIdx = StartArg; ArgIdx < NumArgs; ++ArgIdx) { 4531 switch (CompareImplicitConversionSequences(Cand1.Conversions[ArgIdx], 4532 Cand2.Conversions[ArgIdx])) { 4533 case ImplicitConversionSequence::Better: 4534 // Cand1 has a better conversion sequence. 4535 HasBetterConversion = true; 4536 break; 4537 4538 case ImplicitConversionSequence::Worse: 4539 // Cand1 can't be better than Cand2. 4540 return false; 4541 4542 case ImplicitConversionSequence::Indistinguishable: 4543 // Do nothing. 4544 break; 4545 } 4546 } 4547 4548 // -- for some argument j, ICSj(F1) is a better conversion sequence than 4549 // ICSj(F2), or, if not that, 4550 if (HasBetterConversion) 4551 return true; 4552 4553 // - F1 is a non-template function and F2 is a function template 4554 // specialization, or, if not that, 4555 if (Cand1.Function && !Cand1.Function->getPrimaryTemplate() && 4556 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 4557 return true; 4558 4559 // -- F1 and F2 are function template specializations, and the function 4560 // template for F1 is more specialized than the template for F2 4561 // according to the partial ordering rules described in 14.5.5.2, or, 4562 // if not that, 4563 if (Cand1.Function && Cand1.Function->getPrimaryTemplate() && 4564 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 4565 if (FunctionTemplateDecl *BetterTemplate 4566 = getMoreSpecializedTemplate(Cand1.Function->getPrimaryTemplate(), 4567 Cand2.Function->getPrimaryTemplate(), 4568 Loc, 4569 isa<CXXConversionDecl>(Cand1.Function)? TPOC_Conversion 4570 : TPOC_Call)) 4571 return BetterTemplate == Cand1.Function->getPrimaryTemplate(); 4572 4573 // -- the context is an initialization by user-defined conversion 4574 // (see 8.5, 13.3.1.5) and the standard conversion sequence 4575 // from the return type of F1 to the destination type (i.e., 4576 // the type of the entity being initialized) is a better 4577 // conversion sequence than the standard conversion sequence 4578 // from the return type of F2 to the destination type. 4579 if (Cand1.Function && Cand2.Function && 4580 isa<CXXConversionDecl>(Cand1.Function) && 4581 isa<CXXConversionDecl>(Cand2.Function)) { 4582 switch (CompareStandardConversionSequences(Cand1.FinalConversion, 4583 Cand2.FinalConversion)) { 4584 case ImplicitConversionSequence::Better: 4585 // Cand1 has a better conversion sequence. 4586 return true; 4587 4588 case ImplicitConversionSequence::Worse: 4589 // Cand1 can't be better than Cand2. 4590 return false; 4591 4592 case ImplicitConversionSequence::Indistinguishable: 4593 // Do nothing 4594 break; 4595 } 4596 } 4597 4598 return false; 4599} 4600 4601/// \brief Computes the best viable function (C++ 13.3.3) 4602/// within an overload candidate set. 4603/// 4604/// \param CandidateSet the set of candidate functions. 4605/// 4606/// \param Loc the location of the function name (or operator symbol) for 4607/// which overload resolution occurs. 4608/// 4609/// \param Best f overload resolution was successful or found a deleted 4610/// function, Best points to the candidate function found. 4611/// 4612/// \returns The result of overload resolution. 4613OverloadingResult Sema::BestViableFunction(OverloadCandidateSet& CandidateSet, 4614 SourceLocation Loc, 4615 OverloadCandidateSet::iterator& Best) { 4616 // Find the best viable function. 4617 Best = CandidateSet.end(); 4618 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 4619 Cand != CandidateSet.end(); ++Cand) { 4620 if (Cand->Viable) { 4621 if (Best == CandidateSet.end() || 4622 isBetterOverloadCandidate(*Cand, *Best, Loc)) 4623 Best = Cand; 4624 } 4625 } 4626 4627 // If we didn't find any viable functions, abort. 4628 if (Best == CandidateSet.end()) 4629 return OR_No_Viable_Function; 4630 4631 // Make sure that this function is better than every other viable 4632 // function. If not, we have an ambiguity. 4633 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 4634 Cand != CandidateSet.end(); ++Cand) { 4635 if (Cand->Viable && 4636 Cand != Best && 4637 !isBetterOverloadCandidate(*Best, *Cand, Loc)) { 4638 Best = CandidateSet.end(); 4639 return OR_Ambiguous; 4640 } 4641 } 4642 4643 // Best is the best viable function. 4644 if (Best->Function && 4645 (Best->Function->isDeleted() || 4646 Best->Function->getAttr<UnavailableAttr>())) 4647 return OR_Deleted; 4648 4649 // C++ [basic.def.odr]p2: 4650 // An overloaded function is used if it is selected by overload resolution 4651 // when referred to from a potentially-evaluated expression. [Note: this 4652 // covers calls to named functions (5.2.2), operator overloading 4653 // (clause 13), user-defined conversions (12.3.2), allocation function for 4654 // placement new (5.3.4), as well as non-default initialization (8.5). 4655 if (Best->Function) 4656 MarkDeclarationReferenced(Loc, Best->Function); 4657 return OR_Success; 4658} 4659 4660namespace { 4661 4662enum OverloadCandidateKind { 4663 oc_function, 4664 oc_method, 4665 oc_constructor, 4666 oc_function_template, 4667 oc_method_template, 4668 oc_constructor_template, 4669 oc_implicit_default_constructor, 4670 oc_implicit_copy_constructor, 4671 oc_implicit_copy_assignment 4672}; 4673 4674OverloadCandidateKind ClassifyOverloadCandidate(Sema &S, 4675 FunctionDecl *Fn, 4676 std::string &Description) { 4677 bool isTemplate = false; 4678 4679 if (FunctionTemplateDecl *FunTmpl = Fn->getPrimaryTemplate()) { 4680 isTemplate = true; 4681 Description = S.getTemplateArgumentBindingsText( 4682 FunTmpl->getTemplateParameters(), *Fn->getTemplateSpecializationArgs()); 4683 } 4684 4685 if (CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(Fn)) { 4686 if (!Ctor->isImplicit()) 4687 return isTemplate ? oc_constructor_template : oc_constructor; 4688 4689 return Ctor->isCopyConstructor() ? oc_implicit_copy_constructor 4690 : oc_implicit_default_constructor; 4691 } 4692 4693 if (CXXMethodDecl *Meth = dyn_cast<CXXMethodDecl>(Fn)) { 4694 // This actually gets spelled 'candidate function' for now, but 4695 // it doesn't hurt to split it out. 4696 if (!Meth->isImplicit()) 4697 return isTemplate ? oc_method_template : oc_method; 4698 4699 assert(Meth->isCopyAssignment() 4700 && "implicit method is not copy assignment operator?"); 4701 return oc_implicit_copy_assignment; 4702 } 4703 4704 return isTemplate ? oc_function_template : oc_function; 4705} 4706 4707} // end anonymous namespace 4708 4709// Notes the location of an overload candidate. 4710void Sema::NoteOverloadCandidate(FunctionDecl *Fn) { 4711 std::string FnDesc; 4712 OverloadCandidateKind K = ClassifyOverloadCandidate(*this, Fn, FnDesc); 4713 Diag(Fn->getLocation(), diag::note_ovl_candidate) 4714 << (unsigned) K << FnDesc; 4715} 4716 4717/// Diagnoses an ambiguous conversion. The partial diagnostic is the 4718/// "lead" diagnostic; it will be given two arguments, the source and 4719/// target types of the conversion. 4720void Sema::DiagnoseAmbiguousConversion(const ImplicitConversionSequence &ICS, 4721 SourceLocation CaretLoc, 4722 const PartialDiagnostic &PDiag) { 4723 Diag(CaretLoc, PDiag) 4724 << ICS.Ambiguous.getFromType() << ICS.Ambiguous.getToType(); 4725 for (AmbiguousConversionSequence::const_iterator 4726 I = ICS.Ambiguous.begin(), E = ICS.Ambiguous.end(); I != E; ++I) { 4727 NoteOverloadCandidate(*I); 4728 } 4729} 4730 4731namespace { 4732 4733void DiagnoseBadConversion(Sema &S, OverloadCandidate *Cand, unsigned I) { 4734 const ImplicitConversionSequence &Conv = Cand->Conversions[I]; 4735 assert(Conv.isBad()); 4736 assert(Cand->Function && "for now, candidate must be a function"); 4737 FunctionDecl *Fn = Cand->Function; 4738 4739 // There's a conversion slot for the object argument if this is a 4740 // non-constructor method. Note that 'I' corresponds the 4741 // conversion-slot index. 4742 bool isObjectArgument = false; 4743 if (isa<CXXMethodDecl>(Fn) && !isa<CXXConstructorDecl>(Fn)) { 4744 if (I == 0) 4745 isObjectArgument = true; 4746 else 4747 I--; 4748 } 4749 4750 std::string FnDesc; 4751 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, FnDesc); 4752 4753 Expr *FromExpr = Conv.Bad.FromExpr; 4754 QualType FromTy = Conv.Bad.getFromType(); 4755 QualType ToTy = Conv.Bad.getToType(); 4756 4757 if (FromTy == S.Context.OverloadTy) { 4758 assert(FromExpr && "overload set argument came from implicit argument?"); 4759 Expr *E = FromExpr->IgnoreParens(); 4760 if (isa<UnaryOperator>(E)) 4761 E = cast<UnaryOperator>(E)->getSubExpr()->IgnoreParens(); 4762 DeclarationName Name = cast<OverloadExpr>(E)->getName(); 4763 4764 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_overload) 4765 << (unsigned) FnKind << FnDesc 4766 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 4767 << ToTy << Name << I+1; 4768 return; 4769 } 4770 4771 // Do some hand-waving analysis to see if the non-viability is due 4772 // to a qualifier mismatch. 4773 CanQualType CFromTy = S.Context.getCanonicalType(FromTy); 4774 CanQualType CToTy = S.Context.getCanonicalType(ToTy); 4775 if (CanQual<ReferenceType> RT = CToTy->getAs<ReferenceType>()) 4776 CToTy = RT->getPointeeType(); 4777 else { 4778 // TODO: detect and diagnose the full richness of const mismatches. 4779 if (CanQual<PointerType> FromPT = CFromTy->getAs<PointerType>()) 4780 if (CanQual<PointerType> ToPT = CToTy->getAs<PointerType>()) 4781 CFromTy = FromPT->getPointeeType(), CToTy = ToPT->getPointeeType(); 4782 } 4783 4784 if (CToTy.getUnqualifiedType() == CFromTy.getUnqualifiedType() && 4785 !CToTy.isAtLeastAsQualifiedAs(CFromTy)) { 4786 // It is dumb that we have to do this here. 4787 while (isa<ArrayType>(CFromTy)) 4788 CFromTy = CFromTy->getAs<ArrayType>()->getElementType(); 4789 while (isa<ArrayType>(CToTy)) 4790 CToTy = CFromTy->getAs<ArrayType>()->getElementType(); 4791 4792 Qualifiers FromQs = CFromTy.getQualifiers(); 4793 Qualifiers ToQs = CToTy.getQualifiers(); 4794 4795 if (FromQs.getAddressSpace() != ToQs.getAddressSpace()) { 4796 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_addrspace) 4797 << (unsigned) FnKind << FnDesc 4798 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 4799 << FromTy 4800 << FromQs.getAddressSpace() << ToQs.getAddressSpace() 4801 << (unsigned) isObjectArgument << I+1; 4802 return; 4803 } 4804 4805 unsigned CVR = FromQs.getCVRQualifiers() & ~ToQs.getCVRQualifiers(); 4806 assert(CVR && "unexpected qualifiers mismatch"); 4807 4808 if (isObjectArgument) { 4809 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr_this) 4810 << (unsigned) FnKind << FnDesc 4811 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 4812 << FromTy << (CVR - 1); 4813 } else { 4814 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr) 4815 << (unsigned) FnKind << FnDesc 4816 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 4817 << FromTy << (CVR - 1) << I+1; 4818 } 4819 return; 4820 } 4821 4822 // Diagnose references or pointers to incomplete types differently, 4823 // since it's far from impossible that the incompleteness triggered 4824 // the failure. 4825 QualType TempFromTy = FromTy.getNonReferenceType(); 4826 if (const PointerType *PTy = TempFromTy->getAs<PointerType>()) 4827 TempFromTy = PTy->getPointeeType(); 4828 if (TempFromTy->isIncompleteType()) { 4829 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_conv_incomplete) 4830 << (unsigned) FnKind << FnDesc 4831 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 4832 << FromTy << ToTy << (unsigned) isObjectArgument << I+1; 4833 return; 4834 } 4835 4836 // TODO: specialize more based on the kind of mismatch 4837 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_conv) 4838 << (unsigned) FnKind << FnDesc 4839 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 4840 << FromTy << ToTy << (unsigned) isObjectArgument << I+1; 4841} 4842 4843void DiagnoseArityMismatch(Sema &S, OverloadCandidate *Cand, 4844 unsigned NumFormalArgs) { 4845 // TODO: treat calls to a missing default constructor as a special case 4846 4847 FunctionDecl *Fn = Cand->Function; 4848 const FunctionProtoType *FnTy = Fn->getType()->getAs<FunctionProtoType>(); 4849 4850 unsigned MinParams = Fn->getMinRequiredArguments(); 4851 4852 // at least / at most / exactly 4853 unsigned mode, modeCount; 4854 if (NumFormalArgs < MinParams) { 4855 assert(Cand->FailureKind == ovl_fail_too_few_arguments); 4856 if (MinParams != FnTy->getNumArgs() || FnTy->isVariadic()) 4857 mode = 0; // "at least" 4858 else 4859 mode = 2; // "exactly" 4860 modeCount = MinParams; 4861 } else { 4862 assert(Cand->FailureKind == ovl_fail_too_many_arguments); 4863 if (MinParams != FnTy->getNumArgs()) 4864 mode = 1; // "at most" 4865 else 4866 mode = 2; // "exactly" 4867 modeCount = FnTy->getNumArgs(); 4868 } 4869 4870 std::string Description; 4871 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, Description); 4872 4873 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_arity) 4874 << (unsigned) FnKind << Description << mode << modeCount << NumFormalArgs; 4875} 4876 4877/// Diagnose a failed template-argument deduction. 4878void DiagnoseBadDeduction(Sema &S, OverloadCandidate *Cand, 4879 Expr **Args, unsigned NumArgs) { 4880 FunctionDecl *Fn = Cand->Function; // pattern 4881 4882 TemplateParameter Param = TemplateParameter::getFromOpaqueValue( 4883 Cand->DeductionFailure.TemplateParameter); 4884 4885 switch (Cand->DeductionFailure.Result) { 4886 case Sema::TDK_Success: 4887 llvm_unreachable("TDK_success while diagnosing bad deduction"); 4888 4889 case Sema::TDK_Incomplete: { 4890 NamedDecl *ParamD; 4891 (ParamD = Param.dyn_cast<TemplateTypeParmDecl*>()) || 4892 (ParamD = Param.dyn_cast<NonTypeTemplateParmDecl*>()) || 4893 (ParamD = Param.dyn_cast<TemplateTemplateParmDecl*>()); 4894 assert(ParamD && "no parameter found for incomplete deduction result"); 4895 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_incomplete_deduction) 4896 << ParamD->getDeclName(); 4897 return; 4898 } 4899 4900 // TODO: diagnose these individually, then kill off 4901 // note_ovl_candidate_bad_deduction, which is uselessly vague. 4902 case Sema::TDK_InstantiationDepth: 4903 case Sema::TDK_Inconsistent: 4904 case Sema::TDK_InconsistentQuals: 4905 case Sema::TDK_SubstitutionFailure: 4906 case Sema::TDK_NonDeducedMismatch: 4907 case Sema::TDK_TooManyArguments: 4908 case Sema::TDK_TooFewArguments: 4909 case Sema::TDK_InvalidExplicitArguments: 4910 case Sema::TDK_FailedOverloadResolution: 4911 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_deduction); 4912 return; 4913 } 4914} 4915 4916/// Generates a 'note' diagnostic for an overload candidate. We've 4917/// already generated a primary error at the call site. 4918/// 4919/// It really does need to be a single diagnostic with its caret 4920/// pointed at the candidate declaration. Yes, this creates some 4921/// major challenges of technical writing. Yes, this makes pointing 4922/// out problems with specific arguments quite awkward. It's still 4923/// better than generating twenty screens of text for every failed 4924/// overload. 4925/// 4926/// It would be great to be able to express per-candidate problems 4927/// more richly for those diagnostic clients that cared, but we'd 4928/// still have to be just as careful with the default diagnostics. 4929void NoteFunctionCandidate(Sema &S, OverloadCandidate *Cand, 4930 Expr **Args, unsigned NumArgs) { 4931 FunctionDecl *Fn = Cand->Function; 4932 4933 // Note deleted candidates, but only if they're viable. 4934 if (Cand->Viable && (Fn->isDeleted() || Fn->hasAttr<UnavailableAttr>())) { 4935 std::string FnDesc; 4936 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, FnDesc); 4937 4938 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_deleted) 4939 << FnKind << FnDesc << Fn->isDeleted(); 4940 return; 4941 } 4942 4943 // We don't really have anything else to say about viable candidates. 4944 if (Cand->Viable) { 4945 S.NoteOverloadCandidate(Fn); 4946 return; 4947 } 4948 4949 switch (Cand->FailureKind) { 4950 case ovl_fail_too_many_arguments: 4951 case ovl_fail_too_few_arguments: 4952 return DiagnoseArityMismatch(S, Cand, NumArgs); 4953 4954 case ovl_fail_bad_deduction: 4955 return DiagnoseBadDeduction(S, Cand, Args, NumArgs); 4956 4957 case ovl_fail_trivial_conversion: 4958 case ovl_fail_bad_final_conversion: 4959 case ovl_fail_final_conversion_not_exact: 4960 return S.NoteOverloadCandidate(Fn); 4961 4962 case ovl_fail_bad_conversion: { 4963 unsigned I = (Cand->IgnoreObjectArgument ? 1 : 0); 4964 for (unsigned N = Cand->Conversions.size(); I != N; ++I) 4965 if (Cand->Conversions[I].isBad()) 4966 return DiagnoseBadConversion(S, Cand, I); 4967 4968 // FIXME: this currently happens when we're called from SemaInit 4969 // when user-conversion overload fails. Figure out how to handle 4970 // those conditions and diagnose them well. 4971 return S.NoteOverloadCandidate(Fn); 4972 } 4973 } 4974} 4975 4976void NoteSurrogateCandidate(Sema &S, OverloadCandidate *Cand) { 4977 // Desugar the type of the surrogate down to a function type, 4978 // retaining as many typedefs as possible while still showing 4979 // the function type (and, therefore, its parameter types). 4980 QualType FnType = Cand->Surrogate->getConversionType(); 4981 bool isLValueReference = false; 4982 bool isRValueReference = false; 4983 bool isPointer = false; 4984 if (const LValueReferenceType *FnTypeRef = 4985 FnType->getAs<LValueReferenceType>()) { 4986 FnType = FnTypeRef->getPointeeType(); 4987 isLValueReference = true; 4988 } else if (const RValueReferenceType *FnTypeRef = 4989 FnType->getAs<RValueReferenceType>()) { 4990 FnType = FnTypeRef->getPointeeType(); 4991 isRValueReference = true; 4992 } 4993 if (const PointerType *FnTypePtr = FnType->getAs<PointerType>()) { 4994 FnType = FnTypePtr->getPointeeType(); 4995 isPointer = true; 4996 } 4997 // Desugar down to a function type. 4998 FnType = QualType(FnType->getAs<FunctionType>(), 0); 4999 // Reconstruct the pointer/reference as appropriate. 5000 if (isPointer) FnType = S.Context.getPointerType(FnType); 5001 if (isRValueReference) FnType = S.Context.getRValueReferenceType(FnType); 5002 if (isLValueReference) FnType = S.Context.getLValueReferenceType(FnType); 5003 5004 S.Diag(Cand->Surrogate->getLocation(), diag::note_ovl_surrogate_cand) 5005 << FnType; 5006} 5007 5008void NoteBuiltinOperatorCandidate(Sema &S, 5009 const char *Opc, 5010 SourceLocation OpLoc, 5011 OverloadCandidate *Cand) { 5012 assert(Cand->Conversions.size() <= 2 && "builtin operator is not binary"); 5013 std::string TypeStr("operator"); 5014 TypeStr += Opc; 5015 TypeStr += "("; 5016 TypeStr += Cand->BuiltinTypes.ParamTypes[0].getAsString(); 5017 if (Cand->Conversions.size() == 1) { 5018 TypeStr += ")"; 5019 S.Diag(OpLoc, diag::note_ovl_builtin_unary_candidate) << TypeStr; 5020 } else { 5021 TypeStr += ", "; 5022 TypeStr += Cand->BuiltinTypes.ParamTypes[1].getAsString(); 5023 TypeStr += ")"; 5024 S.Diag(OpLoc, diag::note_ovl_builtin_binary_candidate) << TypeStr; 5025 } 5026} 5027 5028void NoteAmbiguousUserConversions(Sema &S, SourceLocation OpLoc, 5029 OverloadCandidate *Cand) { 5030 unsigned NoOperands = Cand->Conversions.size(); 5031 for (unsigned ArgIdx = 0; ArgIdx < NoOperands; ++ArgIdx) { 5032 const ImplicitConversionSequence &ICS = Cand->Conversions[ArgIdx]; 5033 if (ICS.isBad()) break; // all meaningless after first invalid 5034 if (!ICS.isAmbiguous()) continue; 5035 5036 S.DiagnoseAmbiguousConversion(ICS, OpLoc, 5037 S.PDiag(diag::note_ambiguous_type_conversion)); 5038 } 5039} 5040 5041SourceLocation GetLocationForCandidate(const OverloadCandidate *Cand) { 5042 if (Cand->Function) 5043 return Cand->Function->getLocation(); 5044 if (Cand->IsSurrogate) 5045 return Cand->Surrogate->getLocation(); 5046 return SourceLocation(); 5047} 5048 5049struct CompareOverloadCandidatesForDisplay { 5050 Sema &S; 5051 CompareOverloadCandidatesForDisplay(Sema &S) : S(S) {} 5052 5053 bool operator()(const OverloadCandidate *L, 5054 const OverloadCandidate *R) { 5055 // Fast-path this check. 5056 if (L == R) return false; 5057 5058 // Order first by viability. 5059 if (L->Viable) { 5060 if (!R->Viable) return true; 5061 5062 // TODO: introduce a tri-valued comparison for overload 5063 // candidates. Would be more worthwhile if we had a sort 5064 // that could exploit it. 5065 if (S.isBetterOverloadCandidate(*L, *R, SourceLocation())) return true; 5066 if (S.isBetterOverloadCandidate(*R, *L, SourceLocation())) return false; 5067 } else if (R->Viable) 5068 return false; 5069 5070 assert(L->Viable == R->Viable); 5071 5072 // Criteria by which we can sort non-viable candidates: 5073 if (!L->Viable) { 5074 // 1. Arity mismatches come after other candidates. 5075 if (L->FailureKind == ovl_fail_too_many_arguments || 5076 L->FailureKind == ovl_fail_too_few_arguments) 5077 return false; 5078 if (R->FailureKind == ovl_fail_too_many_arguments || 5079 R->FailureKind == ovl_fail_too_few_arguments) 5080 return true; 5081 5082 // 2. Bad conversions come first and are ordered by the number 5083 // of bad conversions and quality of good conversions. 5084 if (L->FailureKind == ovl_fail_bad_conversion) { 5085 if (R->FailureKind != ovl_fail_bad_conversion) 5086 return true; 5087 5088 // If there's any ordering between the defined conversions... 5089 // FIXME: this might not be transitive. 5090 assert(L->Conversions.size() == R->Conversions.size()); 5091 5092 int leftBetter = 0; 5093 unsigned I = (L->IgnoreObjectArgument || R->IgnoreObjectArgument); 5094 for (unsigned E = L->Conversions.size(); I != E; ++I) { 5095 switch (S.CompareImplicitConversionSequences(L->Conversions[I], 5096 R->Conversions[I])) { 5097 case ImplicitConversionSequence::Better: 5098 leftBetter++; 5099 break; 5100 5101 case ImplicitConversionSequence::Worse: 5102 leftBetter--; 5103 break; 5104 5105 case ImplicitConversionSequence::Indistinguishable: 5106 break; 5107 } 5108 } 5109 if (leftBetter > 0) return true; 5110 if (leftBetter < 0) return false; 5111 5112 } else if (R->FailureKind == ovl_fail_bad_conversion) 5113 return false; 5114 5115 // TODO: others? 5116 } 5117 5118 // Sort everything else by location. 5119 SourceLocation LLoc = GetLocationForCandidate(L); 5120 SourceLocation RLoc = GetLocationForCandidate(R); 5121 5122 // Put candidates without locations (e.g. builtins) at the end. 5123 if (LLoc.isInvalid()) return false; 5124 if (RLoc.isInvalid()) return true; 5125 5126 return S.SourceMgr.isBeforeInTranslationUnit(LLoc, RLoc); 5127 } 5128}; 5129 5130/// CompleteNonViableCandidate - Normally, overload resolution only 5131/// computes up to the first 5132void CompleteNonViableCandidate(Sema &S, OverloadCandidate *Cand, 5133 Expr **Args, unsigned NumArgs) { 5134 assert(!Cand->Viable); 5135 5136 // Don't do anything on failures other than bad conversion. 5137 if (Cand->FailureKind != ovl_fail_bad_conversion) return; 5138 5139 // Skip forward to the first bad conversion. 5140 unsigned ConvIdx = (Cand->IgnoreObjectArgument ? 1 : 0); 5141 unsigned ConvCount = Cand->Conversions.size(); 5142 while (true) { 5143 assert(ConvIdx != ConvCount && "no bad conversion in candidate"); 5144 ConvIdx++; 5145 if (Cand->Conversions[ConvIdx - 1].isBad()) 5146 break; 5147 } 5148 5149 if (ConvIdx == ConvCount) 5150 return; 5151 5152 assert(!Cand->Conversions[ConvIdx].isInitialized() && 5153 "remaining conversion is initialized?"); 5154 5155 // FIXME: these should probably be preserved from the overload 5156 // operation somehow. 5157 bool SuppressUserConversions = false; 5158 bool ForceRValue = false; 5159 5160 const FunctionProtoType* Proto; 5161 unsigned ArgIdx = ConvIdx; 5162 5163 if (Cand->IsSurrogate) { 5164 QualType ConvType 5165 = Cand->Surrogate->getConversionType().getNonReferenceType(); 5166 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 5167 ConvType = ConvPtrType->getPointeeType(); 5168 Proto = ConvType->getAs<FunctionProtoType>(); 5169 ArgIdx--; 5170 } else if (Cand->Function) { 5171 Proto = Cand->Function->getType()->getAs<FunctionProtoType>(); 5172 if (isa<CXXMethodDecl>(Cand->Function) && 5173 !isa<CXXConstructorDecl>(Cand->Function)) 5174 ArgIdx--; 5175 } else { 5176 // Builtin binary operator with a bad first conversion. 5177 assert(ConvCount <= 3); 5178 for (; ConvIdx != ConvCount; ++ConvIdx) 5179 Cand->Conversions[ConvIdx] 5180 = S.TryCopyInitialization(Args[ConvIdx], 5181 Cand->BuiltinTypes.ParamTypes[ConvIdx], 5182 SuppressUserConversions, ForceRValue, 5183 /*InOverloadResolution*/ true); 5184 return; 5185 } 5186 5187 // Fill in the rest of the conversions. 5188 unsigned NumArgsInProto = Proto->getNumArgs(); 5189 for (; ConvIdx != ConvCount; ++ConvIdx, ++ArgIdx) { 5190 if (ArgIdx < NumArgsInProto) 5191 Cand->Conversions[ConvIdx] 5192 = S.TryCopyInitialization(Args[ArgIdx], Proto->getArgType(ArgIdx), 5193 SuppressUserConversions, ForceRValue, 5194 /*InOverloadResolution=*/true); 5195 else 5196 Cand->Conversions[ConvIdx].setEllipsis(); 5197 } 5198} 5199 5200} // end anonymous namespace 5201 5202/// PrintOverloadCandidates - When overload resolution fails, prints 5203/// diagnostic messages containing the candidates in the candidate 5204/// set. 5205void 5206Sema::PrintOverloadCandidates(OverloadCandidateSet& CandidateSet, 5207 OverloadCandidateDisplayKind OCD, 5208 Expr **Args, unsigned NumArgs, 5209 const char *Opc, 5210 SourceLocation OpLoc) { 5211 // Sort the candidates by viability and position. Sorting directly would 5212 // be prohibitive, so we make a set of pointers and sort those. 5213 llvm::SmallVector<OverloadCandidate*, 32> Cands; 5214 if (OCD == OCD_AllCandidates) Cands.reserve(CandidateSet.size()); 5215 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 5216 LastCand = CandidateSet.end(); 5217 Cand != LastCand; ++Cand) { 5218 if (Cand->Viable) 5219 Cands.push_back(Cand); 5220 else if (OCD == OCD_AllCandidates) { 5221 CompleteNonViableCandidate(*this, Cand, Args, NumArgs); 5222 Cands.push_back(Cand); 5223 } 5224 } 5225 5226 std::sort(Cands.begin(), Cands.end(), 5227 CompareOverloadCandidatesForDisplay(*this)); 5228 5229 bool ReportedAmbiguousConversions = false; 5230 5231 llvm::SmallVectorImpl<OverloadCandidate*>::iterator I, E; 5232 for (I = Cands.begin(), E = Cands.end(); I != E; ++I) { 5233 OverloadCandidate *Cand = *I; 5234 5235 if (Cand->Function) 5236 NoteFunctionCandidate(*this, Cand, Args, NumArgs); 5237 else if (Cand->IsSurrogate) 5238 NoteSurrogateCandidate(*this, Cand); 5239 5240 // This a builtin candidate. We do not, in general, want to list 5241 // every possible builtin candidate. 5242 else if (Cand->Viable) { 5243 // Generally we only see ambiguities including viable builtin 5244 // operators if overload resolution got screwed up by an 5245 // ambiguous user-defined conversion. 5246 // 5247 // FIXME: It's quite possible for different conversions to see 5248 // different ambiguities, though. 5249 if (!ReportedAmbiguousConversions) { 5250 NoteAmbiguousUserConversions(*this, OpLoc, Cand); 5251 ReportedAmbiguousConversions = true; 5252 } 5253 5254 // If this is a viable builtin, print it. 5255 NoteBuiltinOperatorCandidate(*this, Opc, OpLoc, Cand); 5256 } 5257 } 5258} 5259 5260static bool CheckUnresolvedAccess(Sema &S, OverloadExpr *E, DeclAccessPair D) { 5261 if (isa<UnresolvedLookupExpr>(E)) 5262 return S.CheckUnresolvedLookupAccess(cast<UnresolvedLookupExpr>(E), D); 5263 5264 return S.CheckUnresolvedMemberAccess(cast<UnresolvedMemberExpr>(E), D); 5265} 5266 5267/// ResolveAddressOfOverloadedFunction - Try to resolve the address of 5268/// an overloaded function (C++ [over.over]), where @p From is an 5269/// expression with overloaded function type and @p ToType is the type 5270/// we're trying to resolve to. For example: 5271/// 5272/// @code 5273/// int f(double); 5274/// int f(int); 5275/// 5276/// int (*pfd)(double) = f; // selects f(double) 5277/// @endcode 5278/// 5279/// This routine returns the resulting FunctionDecl if it could be 5280/// resolved, and NULL otherwise. When @p Complain is true, this 5281/// routine will emit diagnostics if there is an error. 5282FunctionDecl * 5283Sema::ResolveAddressOfOverloadedFunction(Expr *From, QualType ToType, 5284 bool Complain, 5285 DeclAccessPair &FoundResult) { 5286 QualType FunctionType = ToType; 5287 bool IsMember = false; 5288 if (const PointerType *ToTypePtr = ToType->getAs<PointerType>()) 5289 FunctionType = ToTypePtr->getPointeeType(); 5290 else if (const ReferenceType *ToTypeRef = ToType->getAs<ReferenceType>()) 5291 FunctionType = ToTypeRef->getPointeeType(); 5292 else if (const MemberPointerType *MemTypePtr = 5293 ToType->getAs<MemberPointerType>()) { 5294 FunctionType = MemTypePtr->getPointeeType(); 5295 IsMember = true; 5296 } 5297 5298 // We only look at pointers or references to functions. 5299 FunctionType = Context.getCanonicalType(FunctionType).getUnqualifiedType(); 5300 if (!FunctionType->isFunctionType()) 5301 return 0; 5302 5303 // Find the actual overloaded function declaration. 5304 if (From->getType() != Context.OverloadTy) 5305 return 0; 5306 5307 // C++ [over.over]p1: 5308 // [...] [Note: any redundant set of parentheses surrounding the 5309 // overloaded function name is ignored (5.1). ] 5310 // C++ [over.over]p1: 5311 // [...] The overloaded function name can be preceded by the & 5312 // operator. 5313 OverloadExpr *OvlExpr = OverloadExpr::find(From).getPointer(); 5314 TemplateArgumentListInfo ETABuffer, *ExplicitTemplateArgs = 0; 5315 if (OvlExpr->hasExplicitTemplateArgs()) { 5316 OvlExpr->getExplicitTemplateArgs().copyInto(ETABuffer); 5317 ExplicitTemplateArgs = &ETABuffer; 5318 } 5319 5320 // Look through all of the overloaded functions, searching for one 5321 // whose type matches exactly. 5322 llvm::SmallVector<std::pair<DeclAccessPair, FunctionDecl*>, 4> Matches; 5323 llvm::SmallVector<FunctionDecl *, 4> NonMatches; 5324 5325 bool FoundNonTemplateFunction = false; 5326 for (UnresolvedSetIterator I = OvlExpr->decls_begin(), 5327 E = OvlExpr->decls_end(); I != E; ++I) { 5328 // Look through any using declarations to find the underlying function. 5329 NamedDecl *Fn = (*I)->getUnderlyingDecl(); 5330 5331 // C++ [over.over]p3: 5332 // Non-member functions and static member functions match 5333 // targets of type "pointer-to-function" or "reference-to-function." 5334 // Nonstatic member functions match targets of 5335 // type "pointer-to-member-function." 5336 // Note that according to DR 247, the containing class does not matter. 5337 5338 if (FunctionTemplateDecl *FunctionTemplate 5339 = dyn_cast<FunctionTemplateDecl>(Fn)) { 5340 if (CXXMethodDecl *Method 5341 = dyn_cast<CXXMethodDecl>(FunctionTemplate->getTemplatedDecl())) { 5342 // Skip non-static function templates when converting to pointer, and 5343 // static when converting to member pointer. 5344 if (Method->isStatic() == IsMember) 5345 continue; 5346 } else if (IsMember) 5347 continue; 5348 5349 // C++ [over.over]p2: 5350 // If the name is a function template, template argument deduction is 5351 // done (14.8.2.2), and if the argument deduction succeeds, the 5352 // resulting template argument list is used to generate a single 5353 // function template specialization, which is added to the set of 5354 // overloaded functions considered. 5355 // FIXME: We don't really want to build the specialization here, do we? 5356 FunctionDecl *Specialization = 0; 5357 TemplateDeductionInfo Info(Context, OvlExpr->getNameLoc()); 5358 if (TemplateDeductionResult Result 5359 = DeduceTemplateArguments(FunctionTemplate, ExplicitTemplateArgs, 5360 FunctionType, Specialization, Info)) { 5361 // FIXME: make a note of the failed deduction for diagnostics. 5362 (void)Result; 5363 } else { 5364 // FIXME: If the match isn't exact, shouldn't we just drop this as 5365 // a candidate? Find a testcase before changing the code. 5366 assert(FunctionType 5367 == Context.getCanonicalType(Specialization->getType())); 5368 Matches.push_back(std::make_pair(I.getPair(), 5369 cast<FunctionDecl>(Specialization->getCanonicalDecl()))); 5370 } 5371 5372 continue; 5373 } 5374 5375 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 5376 // Skip non-static functions when converting to pointer, and static 5377 // when converting to member pointer. 5378 if (Method->isStatic() == IsMember) 5379 continue; 5380 5381 // If we have explicit template arguments, skip non-templates. 5382 if (OvlExpr->hasExplicitTemplateArgs()) 5383 continue; 5384 } else if (IsMember) 5385 continue; 5386 5387 if (FunctionDecl *FunDecl = dyn_cast<FunctionDecl>(Fn)) { 5388 QualType ResultTy; 5389 if (Context.hasSameUnqualifiedType(FunctionType, FunDecl->getType()) || 5390 IsNoReturnConversion(Context, FunDecl->getType(), FunctionType, 5391 ResultTy)) { 5392 Matches.push_back(std::make_pair(I.getPair(), 5393 cast<FunctionDecl>(FunDecl->getCanonicalDecl()))); 5394 FoundNonTemplateFunction = true; 5395 } 5396 } 5397 } 5398 5399 // If there were 0 or 1 matches, we're done. 5400 if (Matches.empty()) 5401 return 0; 5402 else if (Matches.size() == 1) { 5403 FunctionDecl *Result = Matches[0].second; 5404 FoundResult = Matches[0].first; 5405 MarkDeclarationReferenced(From->getLocStart(), Result); 5406 if (Complain) 5407 CheckAddressOfMemberAccess(OvlExpr, Matches[0].first); 5408 return Result; 5409 } 5410 5411 // C++ [over.over]p4: 5412 // If more than one function is selected, [...] 5413 if (!FoundNonTemplateFunction) { 5414 // [...] and any given function template specialization F1 is 5415 // eliminated if the set contains a second function template 5416 // specialization whose function template is more specialized 5417 // than the function template of F1 according to the partial 5418 // ordering rules of 14.5.5.2. 5419 5420 // The algorithm specified above is quadratic. We instead use a 5421 // two-pass algorithm (similar to the one used to identify the 5422 // best viable function in an overload set) that identifies the 5423 // best function template (if it exists). 5424 5425 UnresolvedSet<4> MatchesCopy; // TODO: avoid! 5426 for (unsigned I = 0, E = Matches.size(); I != E; ++I) 5427 MatchesCopy.addDecl(Matches[I].second, Matches[I].first.getAccess()); 5428 5429 UnresolvedSetIterator Result = 5430 getMostSpecialized(MatchesCopy.begin(), MatchesCopy.end(), 5431 TPOC_Other, From->getLocStart(), 5432 PDiag(), 5433 PDiag(diag::err_addr_ovl_ambiguous) 5434 << Matches[0].second->getDeclName(), 5435 PDiag(diag::note_ovl_candidate) 5436 << (unsigned) oc_function_template); 5437 assert(Result != MatchesCopy.end() && "no most-specialized template"); 5438 MarkDeclarationReferenced(From->getLocStart(), *Result); 5439 FoundResult = Matches[Result - MatchesCopy.begin()].first; 5440 if (Complain) 5441 CheckUnresolvedAccess(*this, OvlExpr, FoundResult); 5442 return cast<FunctionDecl>(*Result); 5443 } 5444 5445 // [...] any function template specializations in the set are 5446 // eliminated if the set also contains a non-template function, [...] 5447 for (unsigned I = 0, N = Matches.size(); I != N; ) { 5448 if (Matches[I].second->getPrimaryTemplate() == 0) 5449 ++I; 5450 else { 5451 Matches[I] = Matches[--N]; 5452 Matches.set_size(N); 5453 } 5454 } 5455 5456 // [...] After such eliminations, if any, there shall remain exactly one 5457 // selected function. 5458 if (Matches.size() == 1) { 5459 MarkDeclarationReferenced(From->getLocStart(), Matches[0].second); 5460 FoundResult = Matches[0].first; 5461 if (Complain) 5462 CheckUnresolvedAccess(*this, OvlExpr, Matches[0].first); 5463 return cast<FunctionDecl>(Matches[0].second); 5464 } 5465 5466 // FIXME: We should probably return the same thing that BestViableFunction 5467 // returns (even if we issue the diagnostics here). 5468 Diag(From->getLocStart(), diag::err_addr_ovl_ambiguous) 5469 << Matches[0].second->getDeclName(); 5470 for (unsigned I = 0, E = Matches.size(); I != E; ++I) 5471 NoteOverloadCandidate(Matches[I].second); 5472 return 0; 5473} 5474 5475/// \brief Given an expression that refers to an overloaded function, try to 5476/// resolve that overloaded function expression down to a single function. 5477/// 5478/// This routine can only resolve template-ids that refer to a single function 5479/// template, where that template-id refers to a single template whose template 5480/// arguments are either provided by the template-id or have defaults, 5481/// as described in C++0x [temp.arg.explicit]p3. 5482FunctionDecl *Sema::ResolveSingleFunctionTemplateSpecialization(Expr *From) { 5483 // C++ [over.over]p1: 5484 // [...] [Note: any redundant set of parentheses surrounding the 5485 // overloaded function name is ignored (5.1). ] 5486 // C++ [over.over]p1: 5487 // [...] The overloaded function name can be preceded by the & 5488 // operator. 5489 5490 if (From->getType() != Context.OverloadTy) 5491 return 0; 5492 5493 OverloadExpr *OvlExpr = OverloadExpr::find(From).getPointer(); 5494 5495 // If we didn't actually find any template-ids, we're done. 5496 if (!OvlExpr->hasExplicitTemplateArgs()) 5497 return 0; 5498 5499 TemplateArgumentListInfo ExplicitTemplateArgs; 5500 OvlExpr->getExplicitTemplateArgs().copyInto(ExplicitTemplateArgs); 5501 5502 // Look through all of the overloaded functions, searching for one 5503 // whose type matches exactly. 5504 FunctionDecl *Matched = 0; 5505 for (UnresolvedSetIterator I = OvlExpr->decls_begin(), 5506 E = OvlExpr->decls_end(); I != E; ++I) { 5507 // C++0x [temp.arg.explicit]p3: 5508 // [...] In contexts where deduction is done and fails, or in contexts 5509 // where deduction is not done, if a template argument list is 5510 // specified and it, along with any default template arguments, 5511 // identifies a single function template specialization, then the 5512 // template-id is an lvalue for the function template specialization. 5513 FunctionTemplateDecl *FunctionTemplate = cast<FunctionTemplateDecl>(*I); 5514 5515 // C++ [over.over]p2: 5516 // If the name is a function template, template argument deduction is 5517 // done (14.8.2.2), and if the argument deduction succeeds, the 5518 // resulting template argument list is used to generate a single 5519 // function template specialization, which is added to the set of 5520 // overloaded functions considered. 5521 FunctionDecl *Specialization = 0; 5522 TemplateDeductionInfo Info(Context, OvlExpr->getNameLoc()); 5523 if (TemplateDeductionResult Result 5524 = DeduceTemplateArguments(FunctionTemplate, &ExplicitTemplateArgs, 5525 Specialization, Info)) { 5526 // FIXME: make a note of the failed deduction for diagnostics. 5527 (void)Result; 5528 continue; 5529 } 5530 5531 // Multiple matches; we can't resolve to a single declaration. 5532 if (Matched) 5533 return 0; 5534 5535 Matched = Specialization; 5536 } 5537 5538 return Matched; 5539} 5540 5541/// \brief Add a single candidate to the overload set. 5542static void AddOverloadedCallCandidate(Sema &S, 5543 DeclAccessPair FoundDecl, 5544 const TemplateArgumentListInfo *ExplicitTemplateArgs, 5545 Expr **Args, unsigned NumArgs, 5546 OverloadCandidateSet &CandidateSet, 5547 bool PartialOverloading) { 5548 NamedDecl *Callee = FoundDecl.getDecl(); 5549 if (isa<UsingShadowDecl>(Callee)) 5550 Callee = cast<UsingShadowDecl>(Callee)->getTargetDecl(); 5551 5552 if (FunctionDecl *Func = dyn_cast<FunctionDecl>(Callee)) { 5553 assert(!ExplicitTemplateArgs && "Explicit template arguments?"); 5554 S.AddOverloadCandidate(Func, FoundDecl, Args, NumArgs, CandidateSet, 5555 false, false, PartialOverloading); 5556 return; 5557 } 5558 5559 if (FunctionTemplateDecl *FuncTemplate 5560 = dyn_cast<FunctionTemplateDecl>(Callee)) { 5561 S.AddTemplateOverloadCandidate(FuncTemplate, FoundDecl, 5562 ExplicitTemplateArgs, 5563 Args, NumArgs, CandidateSet); 5564 return; 5565 } 5566 5567 assert(false && "unhandled case in overloaded call candidate"); 5568 5569 // do nothing? 5570} 5571 5572/// \brief Add the overload candidates named by callee and/or found by argument 5573/// dependent lookup to the given overload set. 5574void Sema::AddOverloadedCallCandidates(UnresolvedLookupExpr *ULE, 5575 Expr **Args, unsigned NumArgs, 5576 OverloadCandidateSet &CandidateSet, 5577 bool PartialOverloading) { 5578 5579#ifndef NDEBUG 5580 // Verify that ArgumentDependentLookup is consistent with the rules 5581 // in C++0x [basic.lookup.argdep]p3: 5582 // 5583 // Let X be the lookup set produced by unqualified lookup (3.4.1) 5584 // and let Y be the lookup set produced by argument dependent 5585 // lookup (defined as follows). If X contains 5586 // 5587 // -- a declaration of a class member, or 5588 // 5589 // -- a block-scope function declaration that is not a 5590 // using-declaration, or 5591 // 5592 // -- a declaration that is neither a function or a function 5593 // template 5594 // 5595 // then Y is empty. 5596 5597 if (ULE->requiresADL()) { 5598 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(), 5599 E = ULE->decls_end(); I != E; ++I) { 5600 assert(!(*I)->getDeclContext()->isRecord()); 5601 assert(isa<UsingShadowDecl>(*I) || 5602 !(*I)->getDeclContext()->isFunctionOrMethod()); 5603 assert((*I)->getUnderlyingDecl()->isFunctionOrFunctionTemplate()); 5604 } 5605 } 5606#endif 5607 5608 // It would be nice to avoid this copy. 5609 TemplateArgumentListInfo TABuffer; 5610 const TemplateArgumentListInfo *ExplicitTemplateArgs = 0; 5611 if (ULE->hasExplicitTemplateArgs()) { 5612 ULE->copyTemplateArgumentsInto(TABuffer); 5613 ExplicitTemplateArgs = &TABuffer; 5614 } 5615 5616 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(), 5617 E = ULE->decls_end(); I != E; ++I) 5618 AddOverloadedCallCandidate(*this, I.getPair(), ExplicitTemplateArgs, 5619 Args, NumArgs, CandidateSet, 5620 PartialOverloading); 5621 5622 if (ULE->requiresADL()) 5623 AddArgumentDependentLookupCandidates(ULE->getName(), /*Operator*/ false, 5624 Args, NumArgs, 5625 ExplicitTemplateArgs, 5626 CandidateSet, 5627 PartialOverloading); 5628} 5629 5630static Sema::OwningExprResult Destroy(Sema &SemaRef, Expr *Fn, 5631 Expr **Args, unsigned NumArgs) { 5632 Fn->Destroy(SemaRef.Context); 5633 for (unsigned Arg = 0; Arg < NumArgs; ++Arg) 5634 Args[Arg]->Destroy(SemaRef.Context); 5635 return SemaRef.ExprError(); 5636} 5637 5638/// Attempts to recover from a call where no functions were found. 5639/// 5640/// Returns true if new candidates were found. 5641static Sema::OwningExprResult 5642BuildRecoveryCallExpr(Sema &SemaRef, Scope *S, Expr *Fn, 5643 UnresolvedLookupExpr *ULE, 5644 SourceLocation LParenLoc, 5645 Expr **Args, unsigned NumArgs, 5646 SourceLocation *CommaLocs, 5647 SourceLocation RParenLoc) { 5648 5649 CXXScopeSpec SS; 5650 if (ULE->getQualifier()) { 5651 SS.setScopeRep(ULE->getQualifier()); 5652 SS.setRange(ULE->getQualifierRange()); 5653 } 5654 5655 TemplateArgumentListInfo TABuffer; 5656 const TemplateArgumentListInfo *ExplicitTemplateArgs = 0; 5657 if (ULE->hasExplicitTemplateArgs()) { 5658 ULE->copyTemplateArgumentsInto(TABuffer); 5659 ExplicitTemplateArgs = &TABuffer; 5660 } 5661 5662 LookupResult R(SemaRef, ULE->getName(), ULE->getNameLoc(), 5663 Sema::LookupOrdinaryName); 5664 if (SemaRef.DiagnoseEmptyLookup(S, SS, R)) 5665 return Destroy(SemaRef, Fn, Args, NumArgs); 5666 5667 assert(!R.empty() && "lookup results empty despite recovery"); 5668 5669 // Build an implicit member call if appropriate. Just drop the 5670 // casts and such from the call, we don't really care. 5671 Sema::OwningExprResult NewFn = SemaRef.ExprError(); 5672 if ((*R.begin())->isCXXClassMember()) 5673 NewFn = SemaRef.BuildPossibleImplicitMemberExpr(SS, R, ExplicitTemplateArgs); 5674 else if (ExplicitTemplateArgs) 5675 NewFn = SemaRef.BuildTemplateIdExpr(SS, R, false, *ExplicitTemplateArgs); 5676 else 5677 NewFn = SemaRef.BuildDeclarationNameExpr(SS, R, false); 5678 5679 if (NewFn.isInvalid()) 5680 return Destroy(SemaRef, Fn, Args, NumArgs); 5681 5682 Fn->Destroy(SemaRef.Context); 5683 5684 // This shouldn't cause an infinite loop because we're giving it 5685 // an expression with non-empty lookup results, which should never 5686 // end up here. 5687 return SemaRef.ActOnCallExpr(/*Scope*/ 0, move(NewFn), LParenLoc, 5688 Sema::MultiExprArg(SemaRef, (void**) Args, NumArgs), 5689 CommaLocs, RParenLoc); 5690} 5691 5692/// ResolveOverloadedCallFn - Given the call expression that calls Fn 5693/// (which eventually refers to the declaration Func) and the call 5694/// arguments Args/NumArgs, attempt to resolve the function call down 5695/// to a specific function. If overload resolution succeeds, returns 5696/// the function declaration produced by overload 5697/// resolution. Otherwise, emits diagnostics, deletes all of the 5698/// arguments and Fn, and returns NULL. 5699Sema::OwningExprResult 5700Sema::BuildOverloadedCallExpr(Scope *S, Expr *Fn, UnresolvedLookupExpr *ULE, 5701 SourceLocation LParenLoc, 5702 Expr **Args, unsigned NumArgs, 5703 SourceLocation *CommaLocs, 5704 SourceLocation RParenLoc) { 5705#ifndef NDEBUG 5706 if (ULE->requiresADL()) { 5707 // To do ADL, we must have found an unqualified name. 5708 assert(!ULE->getQualifier() && "qualified name with ADL"); 5709 5710 // We don't perform ADL for implicit declarations of builtins. 5711 // Verify that this was correctly set up. 5712 FunctionDecl *F; 5713 if (ULE->decls_begin() + 1 == ULE->decls_end() && 5714 (F = dyn_cast<FunctionDecl>(*ULE->decls_begin())) && 5715 F->getBuiltinID() && F->isImplicit()) 5716 assert(0 && "performing ADL for builtin"); 5717 5718 // We don't perform ADL in C. 5719 assert(getLangOptions().CPlusPlus && "ADL enabled in C"); 5720 } 5721#endif 5722 5723 OverloadCandidateSet CandidateSet(Fn->getExprLoc()); 5724 5725 // Add the functions denoted by the callee to the set of candidate 5726 // functions, including those from argument-dependent lookup. 5727 AddOverloadedCallCandidates(ULE, Args, NumArgs, CandidateSet); 5728 5729 // If we found nothing, try to recover. 5730 // AddRecoveryCallCandidates diagnoses the error itself, so we just 5731 // bailout out if it fails. 5732 if (CandidateSet.empty()) 5733 return BuildRecoveryCallExpr(*this, S, Fn, ULE, LParenLoc, Args, NumArgs, 5734 CommaLocs, RParenLoc); 5735 5736 OverloadCandidateSet::iterator Best; 5737 switch (BestViableFunction(CandidateSet, Fn->getLocStart(), Best)) { 5738 case OR_Success: { 5739 FunctionDecl *FDecl = Best->Function; 5740 CheckUnresolvedLookupAccess(ULE, Best->FoundDecl); 5741 Fn = FixOverloadedFunctionReference(Fn, Best->FoundDecl, FDecl); 5742 return BuildResolvedCallExpr(Fn, FDecl, LParenLoc, Args, NumArgs, RParenLoc); 5743 } 5744 5745 case OR_No_Viable_Function: 5746 Diag(Fn->getSourceRange().getBegin(), 5747 diag::err_ovl_no_viable_function_in_call) 5748 << ULE->getName() << Fn->getSourceRange(); 5749 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 5750 break; 5751 5752 case OR_Ambiguous: 5753 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_ambiguous_call) 5754 << ULE->getName() << Fn->getSourceRange(); 5755 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, NumArgs); 5756 break; 5757 5758 case OR_Deleted: 5759 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_deleted_call) 5760 << Best->Function->isDeleted() 5761 << ULE->getName() 5762 << Fn->getSourceRange(); 5763 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 5764 break; 5765 } 5766 5767 // Overload resolution failed. Destroy all of the subexpressions and 5768 // return NULL. 5769 Fn->Destroy(Context); 5770 for (unsigned Arg = 0; Arg < NumArgs; ++Arg) 5771 Args[Arg]->Destroy(Context); 5772 return ExprError(); 5773} 5774 5775static bool IsOverloaded(const UnresolvedSetImpl &Functions) { 5776 return Functions.size() > 1 || 5777 (Functions.size() == 1 && isa<FunctionTemplateDecl>(*Functions.begin())); 5778} 5779 5780/// \brief Create a unary operation that may resolve to an overloaded 5781/// operator. 5782/// 5783/// \param OpLoc The location of the operator itself (e.g., '*'). 5784/// 5785/// \param OpcIn The UnaryOperator::Opcode that describes this 5786/// operator. 5787/// 5788/// \param Functions The set of non-member functions that will be 5789/// considered by overload resolution. The caller needs to build this 5790/// set based on the context using, e.g., 5791/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 5792/// set should not contain any member functions; those will be added 5793/// by CreateOverloadedUnaryOp(). 5794/// 5795/// \param input The input argument. 5796Sema::OwningExprResult 5797Sema::CreateOverloadedUnaryOp(SourceLocation OpLoc, unsigned OpcIn, 5798 const UnresolvedSetImpl &Fns, 5799 ExprArg input) { 5800 UnaryOperator::Opcode Opc = static_cast<UnaryOperator::Opcode>(OpcIn); 5801 Expr *Input = (Expr *)input.get(); 5802 5803 OverloadedOperatorKind Op = UnaryOperator::getOverloadedOperator(Opc); 5804 assert(Op != OO_None && "Invalid opcode for overloaded unary operator"); 5805 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 5806 5807 Expr *Args[2] = { Input, 0 }; 5808 unsigned NumArgs = 1; 5809 5810 // For post-increment and post-decrement, add the implicit '0' as 5811 // the second argument, so that we know this is a post-increment or 5812 // post-decrement. 5813 if (Opc == UnaryOperator::PostInc || Opc == UnaryOperator::PostDec) { 5814 llvm::APSInt Zero(Context.getTypeSize(Context.IntTy), false); 5815 Args[1] = new (Context) IntegerLiteral(Zero, Context.IntTy, 5816 SourceLocation()); 5817 NumArgs = 2; 5818 } 5819 5820 if (Input->isTypeDependent()) { 5821 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 5822 UnresolvedLookupExpr *Fn 5823 = UnresolvedLookupExpr::Create(Context, /*Dependent*/ true, NamingClass, 5824 0, SourceRange(), OpName, OpLoc, 5825 /*ADL*/ true, IsOverloaded(Fns)); 5826 Fn->addDecls(Fns.begin(), Fns.end()); 5827 5828 input.release(); 5829 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 5830 &Args[0], NumArgs, 5831 Context.DependentTy, 5832 OpLoc)); 5833 } 5834 5835 // Build an empty overload set. 5836 OverloadCandidateSet CandidateSet(OpLoc); 5837 5838 // Add the candidates from the given function set. 5839 AddFunctionCandidates(Fns, &Args[0], NumArgs, CandidateSet, false); 5840 5841 // Add operator candidates that are member functions. 5842 AddMemberOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 5843 5844 // Add candidates from ADL. 5845 AddArgumentDependentLookupCandidates(OpName, /*Operator*/ true, 5846 Args, NumArgs, 5847 /*ExplicitTemplateArgs*/ 0, 5848 CandidateSet); 5849 5850 // Add builtin operator candidates. 5851 AddBuiltinOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 5852 5853 // Perform overload resolution. 5854 OverloadCandidateSet::iterator Best; 5855 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 5856 case OR_Success: { 5857 // We found a built-in operator or an overloaded operator. 5858 FunctionDecl *FnDecl = Best->Function; 5859 5860 if (FnDecl) { 5861 // We matched an overloaded operator. Build a call to that 5862 // operator. 5863 5864 // Convert the arguments. 5865 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 5866 CheckMemberOperatorAccess(OpLoc, Args[0], 0, Best->FoundDecl); 5867 5868 if (PerformObjectArgumentInitialization(Input, /*Qualifier=*/0, 5869 Best->FoundDecl, Method)) 5870 return ExprError(); 5871 } else { 5872 // Convert the arguments. 5873 OwningExprResult InputInit 5874 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 5875 FnDecl->getParamDecl(0)), 5876 SourceLocation(), 5877 move(input)); 5878 if (InputInit.isInvalid()) 5879 return ExprError(); 5880 5881 input = move(InputInit); 5882 Input = (Expr *)input.get(); 5883 } 5884 5885 // Determine the result type 5886 QualType ResultTy = FnDecl->getResultType().getNonReferenceType(); 5887 5888 // Build the actual expression node. 5889 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 5890 SourceLocation()); 5891 UsualUnaryConversions(FnExpr); 5892 5893 input.release(); 5894 Args[0] = Input; 5895 ExprOwningPtr<CallExpr> TheCall(this, 5896 new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 5897 Args, NumArgs, ResultTy, OpLoc)); 5898 5899 if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall.get(), 5900 FnDecl)) 5901 return ExprError(); 5902 5903 return MaybeBindToTemporary(TheCall.release()); 5904 } else { 5905 // We matched a built-in operator. Convert the arguments, then 5906 // break out so that we will build the appropriate built-in 5907 // operator node. 5908 if (PerformImplicitConversion(Input, Best->BuiltinTypes.ParamTypes[0], 5909 Best->Conversions[0], AA_Passing)) 5910 return ExprError(); 5911 5912 break; 5913 } 5914 } 5915 5916 case OR_No_Viable_Function: 5917 // No viable function; fall through to handling this as a 5918 // built-in operator, which will produce an error message for us. 5919 break; 5920 5921 case OR_Ambiguous: 5922 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 5923 << UnaryOperator::getOpcodeStr(Opc) 5924 << Input->getSourceRange(); 5925 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, NumArgs, 5926 UnaryOperator::getOpcodeStr(Opc), OpLoc); 5927 return ExprError(); 5928 5929 case OR_Deleted: 5930 Diag(OpLoc, diag::err_ovl_deleted_oper) 5931 << Best->Function->isDeleted() 5932 << UnaryOperator::getOpcodeStr(Opc) 5933 << Input->getSourceRange(); 5934 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 5935 return ExprError(); 5936 } 5937 5938 // Either we found no viable overloaded operator or we matched a 5939 // built-in operator. In either case, fall through to trying to 5940 // build a built-in operation. 5941 input.release(); 5942 return CreateBuiltinUnaryOp(OpLoc, Opc, Owned(Input)); 5943} 5944 5945/// \brief Create a binary operation that may resolve to an overloaded 5946/// operator. 5947/// 5948/// \param OpLoc The location of the operator itself (e.g., '+'). 5949/// 5950/// \param OpcIn The BinaryOperator::Opcode that describes this 5951/// operator. 5952/// 5953/// \param Functions The set of non-member functions that will be 5954/// considered by overload resolution. The caller needs to build this 5955/// set based on the context using, e.g., 5956/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 5957/// set should not contain any member functions; those will be added 5958/// by CreateOverloadedBinOp(). 5959/// 5960/// \param LHS Left-hand argument. 5961/// \param RHS Right-hand argument. 5962Sema::OwningExprResult 5963Sema::CreateOverloadedBinOp(SourceLocation OpLoc, 5964 unsigned OpcIn, 5965 const UnresolvedSetImpl &Fns, 5966 Expr *LHS, Expr *RHS) { 5967 Expr *Args[2] = { LHS, RHS }; 5968 LHS=RHS=0; //Please use only Args instead of LHS/RHS couple 5969 5970 BinaryOperator::Opcode Opc = static_cast<BinaryOperator::Opcode>(OpcIn); 5971 OverloadedOperatorKind Op = BinaryOperator::getOverloadedOperator(Opc); 5972 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 5973 5974 // If either side is type-dependent, create an appropriate dependent 5975 // expression. 5976 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 5977 if (Fns.empty()) { 5978 // If there are no functions to store, just build a dependent 5979 // BinaryOperator or CompoundAssignment. 5980 if (Opc <= BinaryOperator::Assign || Opc > BinaryOperator::OrAssign) 5981 return Owned(new (Context) BinaryOperator(Args[0], Args[1], Opc, 5982 Context.DependentTy, OpLoc)); 5983 5984 return Owned(new (Context) CompoundAssignOperator(Args[0], Args[1], Opc, 5985 Context.DependentTy, 5986 Context.DependentTy, 5987 Context.DependentTy, 5988 OpLoc)); 5989 } 5990 5991 // FIXME: save results of ADL from here? 5992 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 5993 UnresolvedLookupExpr *Fn 5994 = UnresolvedLookupExpr::Create(Context, /*Dependent*/ true, NamingClass, 5995 0, SourceRange(), OpName, OpLoc, 5996 /*ADL*/ true, IsOverloaded(Fns)); 5997 5998 Fn->addDecls(Fns.begin(), Fns.end()); 5999 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 6000 Args, 2, 6001 Context.DependentTy, 6002 OpLoc)); 6003 } 6004 6005 // If this is the .* operator, which is not overloadable, just 6006 // create a built-in binary operator. 6007 if (Opc == BinaryOperator::PtrMemD) 6008 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 6009 6010 // If this is the assignment operator, we only perform overload resolution 6011 // if the left-hand side is a class or enumeration type. This is actually 6012 // a hack. The standard requires that we do overload resolution between the 6013 // various built-in candidates, but as DR507 points out, this can lead to 6014 // problems. So we do it this way, which pretty much follows what GCC does. 6015 // Note that we go the traditional code path for compound assignment forms. 6016 if (Opc==BinaryOperator::Assign && !Args[0]->getType()->isOverloadableType()) 6017 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 6018 6019 // Build an empty overload set. 6020 OverloadCandidateSet CandidateSet(OpLoc); 6021 6022 // Add the candidates from the given function set. 6023 AddFunctionCandidates(Fns, Args, 2, CandidateSet, false); 6024 6025 // Add operator candidates that are member functions. 6026 AddMemberOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 6027 6028 // Add candidates from ADL. 6029 AddArgumentDependentLookupCandidates(OpName, /*Operator*/ true, 6030 Args, 2, 6031 /*ExplicitTemplateArgs*/ 0, 6032 CandidateSet); 6033 6034 // Add builtin operator candidates. 6035 AddBuiltinOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 6036 6037 // Perform overload resolution. 6038 OverloadCandidateSet::iterator Best; 6039 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 6040 case OR_Success: { 6041 // We found a built-in operator or an overloaded operator. 6042 FunctionDecl *FnDecl = Best->Function; 6043 6044 if (FnDecl) { 6045 // We matched an overloaded operator. Build a call to that 6046 // operator. 6047 6048 // Convert the arguments. 6049 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 6050 // Best->Access is only meaningful for class members. 6051 CheckMemberOperatorAccess(OpLoc, Args[0], Args[1], Best->FoundDecl); 6052 6053 OwningExprResult Arg1 6054 = PerformCopyInitialization( 6055 InitializedEntity::InitializeParameter( 6056 FnDecl->getParamDecl(0)), 6057 SourceLocation(), 6058 Owned(Args[1])); 6059 if (Arg1.isInvalid()) 6060 return ExprError(); 6061 6062 if (PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/0, 6063 Best->FoundDecl, Method)) 6064 return ExprError(); 6065 6066 Args[1] = RHS = Arg1.takeAs<Expr>(); 6067 } else { 6068 // Convert the arguments. 6069 OwningExprResult Arg0 6070 = PerformCopyInitialization( 6071 InitializedEntity::InitializeParameter( 6072 FnDecl->getParamDecl(0)), 6073 SourceLocation(), 6074 Owned(Args[0])); 6075 if (Arg0.isInvalid()) 6076 return ExprError(); 6077 6078 OwningExprResult Arg1 6079 = PerformCopyInitialization( 6080 InitializedEntity::InitializeParameter( 6081 FnDecl->getParamDecl(1)), 6082 SourceLocation(), 6083 Owned(Args[1])); 6084 if (Arg1.isInvalid()) 6085 return ExprError(); 6086 Args[0] = LHS = Arg0.takeAs<Expr>(); 6087 Args[1] = RHS = Arg1.takeAs<Expr>(); 6088 } 6089 6090 // Determine the result type 6091 QualType ResultTy 6092 = FnDecl->getType()->getAs<FunctionType>()->getResultType(); 6093 ResultTy = ResultTy.getNonReferenceType(); 6094 6095 // Build the actual expression node. 6096 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 6097 OpLoc); 6098 UsualUnaryConversions(FnExpr); 6099 6100 ExprOwningPtr<CXXOperatorCallExpr> 6101 TheCall(this, new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 6102 Args, 2, ResultTy, 6103 OpLoc)); 6104 6105 if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall.get(), 6106 FnDecl)) 6107 return ExprError(); 6108 6109 return MaybeBindToTemporary(TheCall.release()); 6110 } else { 6111 // We matched a built-in operator. Convert the arguments, then 6112 // break out so that we will build the appropriate built-in 6113 // operator node. 6114 if (PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 6115 Best->Conversions[0], AA_Passing) || 6116 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 6117 Best->Conversions[1], AA_Passing)) 6118 return ExprError(); 6119 6120 break; 6121 } 6122 } 6123 6124 case OR_No_Viable_Function: { 6125 // C++ [over.match.oper]p9: 6126 // If the operator is the operator , [...] and there are no 6127 // viable functions, then the operator is assumed to be the 6128 // built-in operator and interpreted according to clause 5. 6129 if (Opc == BinaryOperator::Comma) 6130 break; 6131 6132 // For class as left operand for assignment or compound assigment operator 6133 // do not fall through to handling in built-in, but report that no overloaded 6134 // assignment operator found 6135 OwningExprResult Result = ExprError(); 6136 if (Args[0]->getType()->isRecordType() && 6137 Opc >= BinaryOperator::Assign && Opc <= BinaryOperator::OrAssign) { 6138 Diag(OpLoc, diag::err_ovl_no_viable_oper) 6139 << BinaryOperator::getOpcodeStr(Opc) 6140 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 6141 } else { 6142 // No viable function; try to create a built-in operation, which will 6143 // produce an error. Then, show the non-viable candidates. 6144 Result = CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 6145 } 6146 assert(Result.isInvalid() && 6147 "C++ binary operator overloading is missing candidates!"); 6148 if (Result.isInvalid()) 6149 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2, 6150 BinaryOperator::getOpcodeStr(Opc), OpLoc); 6151 return move(Result); 6152 } 6153 6154 case OR_Ambiguous: 6155 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 6156 << BinaryOperator::getOpcodeStr(Opc) 6157 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 6158 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, 2, 6159 BinaryOperator::getOpcodeStr(Opc), OpLoc); 6160 return ExprError(); 6161 6162 case OR_Deleted: 6163 Diag(OpLoc, diag::err_ovl_deleted_oper) 6164 << Best->Function->isDeleted() 6165 << BinaryOperator::getOpcodeStr(Opc) 6166 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 6167 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2); 6168 return ExprError(); 6169 } 6170 6171 // We matched a built-in operator; build it. 6172 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 6173} 6174 6175Action::OwningExprResult 6176Sema::CreateOverloadedArraySubscriptExpr(SourceLocation LLoc, 6177 SourceLocation RLoc, 6178 ExprArg Base, ExprArg Idx) { 6179 Expr *Args[2] = { static_cast<Expr*>(Base.get()), 6180 static_cast<Expr*>(Idx.get()) }; 6181 DeclarationName OpName = 6182 Context.DeclarationNames.getCXXOperatorName(OO_Subscript); 6183 6184 // If either side is type-dependent, create an appropriate dependent 6185 // expression. 6186 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 6187 6188 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 6189 UnresolvedLookupExpr *Fn 6190 = UnresolvedLookupExpr::Create(Context, /*Dependent*/ true, NamingClass, 6191 0, SourceRange(), OpName, LLoc, 6192 /*ADL*/ true, /*Overloaded*/ false); 6193 // Can't add any actual overloads yet 6194 6195 Base.release(); 6196 Idx.release(); 6197 return Owned(new (Context) CXXOperatorCallExpr(Context, OO_Subscript, Fn, 6198 Args, 2, 6199 Context.DependentTy, 6200 RLoc)); 6201 } 6202 6203 // Build an empty overload set. 6204 OverloadCandidateSet CandidateSet(LLoc); 6205 6206 // Subscript can only be overloaded as a member function. 6207 6208 // Add operator candidates that are member functions. 6209 AddMemberOperatorCandidates(OO_Subscript, LLoc, Args, 2, CandidateSet); 6210 6211 // Add builtin operator candidates. 6212 AddBuiltinOperatorCandidates(OO_Subscript, LLoc, Args, 2, CandidateSet); 6213 6214 // Perform overload resolution. 6215 OverloadCandidateSet::iterator Best; 6216 switch (BestViableFunction(CandidateSet, LLoc, Best)) { 6217 case OR_Success: { 6218 // We found a built-in operator or an overloaded operator. 6219 FunctionDecl *FnDecl = Best->Function; 6220 6221 if (FnDecl) { 6222 // We matched an overloaded operator. Build a call to that 6223 // operator. 6224 6225 CheckMemberOperatorAccess(LLoc, Args[0], Args[1], Best->FoundDecl); 6226 6227 // Convert the arguments. 6228 CXXMethodDecl *Method = cast<CXXMethodDecl>(FnDecl); 6229 if (PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/0, 6230 Best->FoundDecl, Method)) 6231 return ExprError(); 6232 6233 // Convert the arguments. 6234 OwningExprResult InputInit 6235 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 6236 FnDecl->getParamDecl(0)), 6237 SourceLocation(), 6238 Owned(Args[1])); 6239 if (InputInit.isInvalid()) 6240 return ExprError(); 6241 6242 Args[1] = InputInit.takeAs<Expr>(); 6243 6244 // Determine the result type 6245 QualType ResultTy 6246 = FnDecl->getType()->getAs<FunctionType>()->getResultType(); 6247 ResultTy = ResultTy.getNonReferenceType(); 6248 6249 // Build the actual expression node. 6250 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 6251 LLoc); 6252 UsualUnaryConversions(FnExpr); 6253 6254 Base.release(); 6255 Idx.release(); 6256 ExprOwningPtr<CXXOperatorCallExpr> 6257 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Subscript, 6258 FnExpr, Args, 2, 6259 ResultTy, RLoc)); 6260 6261 if (CheckCallReturnType(FnDecl->getResultType(), LLoc, TheCall.get(), 6262 FnDecl)) 6263 return ExprError(); 6264 6265 return MaybeBindToTemporary(TheCall.release()); 6266 } else { 6267 // We matched a built-in operator. Convert the arguments, then 6268 // break out so that we will build the appropriate built-in 6269 // operator node. 6270 if (PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 6271 Best->Conversions[0], AA_Passing) || 6272 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 6273 Best->Conversions[1], AA_Passing)) 6274 return ExprError(); 6275 6276 break; 6277 } 6278 } 6279 6280 case OR_No_Viable_Function: { 6281 if (CandidateSet.empty()) 6282 Diag(LLoc, diag::err_ovl_no_oper) 6283 << Args[0]->getType() << /*subscript*/ 0 6284 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 6285 else 6286 Diag(LLoc, diag::err_ovl_no_viable_subscript) 6287 << Args[0]->getType() 6288 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 6289 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2, 6290 "[]", LLoc); 6291 return ExprError(); 6292 } 6293 6294 case OR_Ambiguous: 6295 Diag(LLoc, diag::err_ovl_ambiguous_oper) 6296 << "[]" << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 6297 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, 2, 6298 "[]", LLoc); 6299 return ExprError(); 6300 6301 case OR_Deleted: 6302 Diag(LLoc, diag::err_ovl_deleted_oper) 6303 << Best->Function->isDeleted() << "[]" 6304 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 6305 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2, 6306 "[]", LLoc); 6307 return ExprError(); 6308 } 6309 6310 // We matched a built-in operator; build it. 6311 Base.release(); 6312 Idx.release(); 6313 return CreateBuiltinArraySubscriptExpr(Owned(Args[0]), LLoc, 6314 Owned(Args[1]), RLoc); 6315} 6316 6317/// BuildCallToMemberFunction - Build a call to a member 6318/// function. MemExpr is the expression that refers to the member 6319/// function (and includes the object parameter), Args/NumArgs are the 6320/// arguments to the function call (not including the object 6321/// parameter). The caller needs to validate that the member 6322/// expression refers to a member function or an overloaded member 6323/// function. 6324Sema::OwningExprResult 6325Sema::BuildCallToMemberFunction(Scope *S, Expr *MemExprE, 6326 SourceLocation LParenLoc, Expr **Args, 6327 unsigned NumArgs, SourceLocation *CommaLocs, 6328 SourceLocation RParenLoc) { 6329 // Dig out the member expression. This holds both the object 6330 // argument and the member function we're referring to. 6331 Expr *NakedMemExpr = MemExprE->IgnoreParens(); 6332 6333 MemberExpr *MemExpr; 6334 CXXMethodDecl *Method = 0; 6335 DeclAccessPair FoundDecl = DeclAccessPair::make(0, AS_public); 6336 NestedNameSpecifier *Qualifier = 0; 6337 if (isa<MemberExpr>(NakedMemExpr)) { 6338 MemExpr = cast<MemberExpr>(NakedMemExpr); 6339 Method = cast<CXXMethodDecl>(MemExpr->getMemberDecl()); 6340 FoundDecl = MemExpr->getFoundDecl(); 6341 Qualifier = MemExpr->getQualifier(); 6342 } else { 6343 UnresolvedMemberExpr *UnresExpr = cast<UnresolvedMemberExpr>(NakedMemExpr); 6344 Qualifier = UnresExpr->getQualifier(); 6345 6346 QualType ObjectType = UnresExpr->getBaseType(); 6347 6348 // Add overload candidates 6349 OverloadCandidateSet CandidateSet(UnresExpr->getMemberLoc()); 6350 6351 // FIXME: avoid copy. 6352 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 6353 if (UnresExpr->hasExplicitTemplateArgs()) { 6354 UnresExpr->copyTemplateArgumentsInto(TemplateArgsBuffer); 6355 TemplateArgs = &TemplateArgsBuffer; 6356 } 6357 6358 for (UnresolvedMemberExpr::decls_iterator I = UnresExpr->decls_begin(), 6359 E = UnresExpr->decls_end(); I != E; ++I) { 6360 6361 NamedDecl *Func = *I; 6362 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(Func->getDeclContext()); 6363 if (isa<UsingShadowDecl>(Func)) 6364 Func = cast<UsingShadowDecl>(Func)->getTargetDecl(); 6365 6366 if ((Method = dyn_cast<CXXMethodDecl>(Func))) { 6367 // If explicit template arguments were provided, we can't call a 6368 // non-template member function. 6369 if (TemplateArgs) 6370 continue; 6371 6372 AddMethodCandidate(Method, I.getPair(), ActingDC, ObjectType, 6373 Args, NumArgs, 6374 CandidateSet, /*SuppressUserConversions=*/false); 6375 } else { 6376 AddMethodTemplateCandidate(cast<FunctionTemplateDecl>(Func), 6377 I.getPair(), ActingDC, TemplateArgs, 6378 ObjectType, Args, NumArgs, 6379 CandidateSet, 6380 /*SuppressUsedConversions=*/false); 6381 } 6382 } 6383 6384 DeclarationName DeclName = UnresExpr->getMemberName(); 6385 6386 OverloadCandidateSet::iterator Best; 6387 switch (BestViableFunction(CandidateSet, UnresExpr->getLocStart(), Best)) { 6388 case OR_Success: 6389 Method = cast<CXXMethodDecl>(Best->Function); 6390 FoundDecl = Best->FoundDecl; 6391 CheckUnresolvedMemberAccess(UnresExpr, Best->FoundDecl); 6392 break; 6393 6394 case OR_No_Viable_Function: 6395 Diag(UnresExpr->getMemberLoc(), 6396 diag::err_ovl_no_viable_member_function_in_call) 6397 << DeclName << MemExprE->getSourceRange(); 6398 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6399 // FIXME: Leaking incoming expressions! 6400 return ExprError(); 6401 6402 case OR_Ambiguous: 6403 Diag(UnresExpr->getMemberLoc(), diag::err_ovl_ambiguous_member_call) 6404 << DeclName << MemExprE->getSourceRange(); 6405 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6406 // FIXME: Leaking incoming expressions! 6407 return ExprError(); 6408 6409 case OR_Deleted: 6410 Diag(UnresExpr->getMemberLoc(), diag::err_ovl_deleted_member_call) 6411 << Best->Function->isDeleted() 6412 << DeclName << MemExprE->getSourceRange(); 6413 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6414 // FIXME: Leaking incoming expressions! 6415 return ExprError(); 6416 } 6417 6418 MemExprE = FixOverloadedFunctionReference(MemExprE, FoundDecl, Method); 6419 6420 // If overload resolution picked a static member, build a 6421 // non-member call based on that function. 6422 if (Method->isStatic()) { 6423 return BuildResolvedCallExpr(MemExprE, Method, LParenLoc, 6424 Args, NumArgs, RParenLoc); 6425 } 6426 6427 MemExpr = cast<MemberExpr>(MemExprE->IgnoreParens()); 6428 } 6429 6430 assert(Method && "Member call to something that isn't a method?"); 6431 ExprOwningPtr<CXXMemberCallExpr> 6432 TheCall(this, new (Context) CXXMemberCallExpr(Context, MemExprE, Args, 6433 NumArgs, 6434 Method->getResultType().getNonReferenceType(), 6435 RParenLoc)); 6436 6437 // Check for a valid return type. 6438 if (CheckCallReturnType(Method->getResultType(), MemExpr->getMemberLoc(), 6439 TheCall.get(), Method)) 6440 return ExprError(); 6441 6442 // Convert the object argument (for a non-static member function call). 6443 // We only need to do this if there was actually an overload; otherwise 6444 // it was done at lookup. 6445 Expr *ObjectArg = MemExpr->getBase(); 6446 if (!Method->isStatic() && 6447 PerformObjectArgumentInitialization(ObjectArg, Qualifier, 6448 FoundDecl, Method)) 6449 return ExprError(); 6450 MemExpr->setBase(ObjectArg); 6451 6452 // Convert the rest of the arguments 6453 const FunctionProtoType *Proto = cast<FunctionProtoType>(Method->getType()); 6454 if (ConvertArgumentsForCall(&*TheCall, MemExpr, Method, Proto, Args, NumArgs, 6455 RParenLoc)) 6456 return ExprError(); 6457 6458 if (CheckFunctionCall(Method, TheCall.get())) 6459 return ExprError(); 6460 6461 return MaybeBindToTemporary(TheCall.release()); 6462} 6463 6464/// BuildCallToObjectOfClassType - Build a call to an object of class 6465/// type (C++ [over.call.object]), which can end up invoking an 6466/// overloaded function call operator (@c operator()) or performing a 6467/// user-defined conversion on the object argument. 6468Sema::ExprResult 6469Sema::BuildCallToObjectOfClassType(Scope *S, Expr *Object, 6470 SourceLocation LParenLoc, 6471 Expr **Args, unsigned NumArgs, 6472 SourceLocation *CommaLocs, 6473 SourceLocation RParenLoc) { 6474 assert(Object->getType()->isRecordType() && "Requires object type argument"); 6475 const RecordType *Record = Object->getType()->getAs<RecordType>(); 6476 6477 // C++ [over.call.object]p1: 6478 // If the primary-expression E in the function call syntax 6479 // evaluates to a class object of type "cv T", then the set of 6480 // candidate functions includes at least the function call 6481 // operators of T. The function call operators of T are obtained by 6482 // ordinary lookup of the name operator() in the context of 6483 // (E).operator(). 6484 OverloadCandidateSet CandidateSet(LParenLoc); 6485 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Call); 6486 6487 if (RequireCompleteType(LParenLoc, Object->getType(), 6488 PDiag(diag::err_incomplete_object_call) 6489 << Object->getSourceRange())) 6490 return true; 6491 6492 LookupResult R(*this, OpName, LParenLoc, LookupOrdinaryName); 6493 LookupQualifiedName(R, Record->getDecl()); 6494 R.suppressDiagnostics(); 6495 6496 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 6497 Oper != OperEnd; ++Oper) { 6498 AddMethodCandidate(Oper.getPair(), Object->getType(), 6499 Args, NumArgs, CandidateSet, 6500 /*SuppressUserConversions=*/ false); 6501 } 6502 6503 // C++ [over.call.object]p2: 6504 // In addition, for each conversion function declared in T of the 6505 // form 6506 // 6507 // operator conversion-type-id () cv-qualifier; 6508 // 6509 // where cv-qualifier is the same cv-qualification as, or a 6510 // greater cv-qualification than, cv, and where conversion-type-id 6511 // denotes the type "pointer to function of (P1,...,Pn) returning 6512 // R", or the type "reference to pointer to function of 6513 // (P1,...,Pn) returning R", or the type "reference to function 6514 // of (P1,...,Pn) returning R", a surrogate call function [...] 6515 // is also considered as a candidate function. Similarly, 6516 // surrogate call functions are added to the set of candidate 6517 // functions for each conversion function declared in an 6518 // accessible base class provided the function is not hidden 6519 // within T by another intervening declaration. 6520 const UnresolvedSetImpl *Conversions 6521 = cast<CXXRecordDecl>(Record->getDecl())->getVisibleConversionFunctions(); 6522 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 6523 E = Conversions->end(); I != E; ++I) { 6524 NamedDecl *D = *I; 6525 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext()); 6526 if (isa<UsingShadowDecl>(D)) 6527 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 6528 6529 // Skip over templated conversion functions; they aren't 6530 // surrogates. 6531 if (isa<FunctionTemplateDecl>(D)) 6532 continue; 6533 6534 CXXConversionDecl *Conv = cast<CXXConversionDecl>(D); 6535 6536 // Strip the reference type (if any) and then the pointer type (if 6537 // any) to get down to what might be a function type. 6538 QualType ConvType = Conv->getConversionType().getNonReferenceType(); 6539 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 6540 ConvType = ConvPtrType->getPointeeType(); 6541 6542 if (const FunctionProtoType *Proto = ConvType->getAs<FunctionProtoType>()) 6543 AddSurrogateCandidate(Conv, I.getPair(), ActingContext, Proto, 6544 Object->getType(), Args, NumArgs, 6545 CandidateSet); 6546 } 6547 6548 // Perform overload resolution. 6549 OverloadCandidateSet::iterator Best; 6550 switch (BestViableFunction(CandidateSet, Object->getLocStart(), Best)) { 6551 case OR_Success: 6552 // Overload resolution succeeded; we'll build the appropriate call 6553 // below. 6554 break; 6555 6556 case OR_No_Viable_Function: 6557 if (CandidateSet.empty()) 6558 Diag(Object->getSourceRange().getBegin(), diag::err_ovl_no_oper) 6559 << Object->getType() << /*call*/ 1 6560 << Object->getSourceRange(); 6561 else 6562 Diag(Object->getSourceRange().getBegin(), 6563 diag::err_ovl_no_viable_object_call) 6564 << Object->getType() << Object->getSourceRange(); 6565 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6566 break; 6567 6568 case OR_Ambiguous: 6569 Diag(Object->getSourceRange().getBegin(), 6570 diag::err_ovl_ambiguous_object_call) 6571 << Object->getType() << Object->getSourceRange(); 6572 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, NumArgs); 6573 break; 6574 6575 case OR_Deleted: 6576 Diag(Object->getSourceRange().getBegin(), 6577 diag::err_ovl_deleted_object_call) 6578 << Best->Function->isDeleted() 6579 << Object->getType() << Object->getSourceRange(); 6580 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6581 break; 6582 } 6583 6584 if (Best == CandidateSet.end()) { 6585 // We had an error; delete all of the subexpressions and return 6586 // the error. 6587 Object->Destroy(Context); 6588 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 6589 Args[ArgIdx]->Destroy(Context); 6590 return true; 6591 } 6592 6593 if (Best->Function == 0) { 6594 // Since there is no function declaration, this is one of the 6595 // surrogate candidates. Dig out the conversion function. 6596 CXXConversionDecl *Conv 6597 = cast<CXXConversionDecl>( 6598 Best->Conversions[0].UserDefined.ConversionFunction); 6599 6600 CheckMemberOperatorAccess(LParenLoc, Object, 0, Best->FoundDecl); 6601 6602 // We selected one of the surrogate functions that converts the 6603 // object parameter to a function pointer. Perform the conversion 6604 // on the object argument, then let ActOnCallExpr finish the job. 6605 6606 // Create an implicit member expr to refer to the conversion operator. 6607 // and then call it. 6608 CXXMemberCallExpr *CE = BuildCXXMemberCallExpr(Object, Best->FoundDecl, 6609 Conv); 6610 6611 return ActOnCallExpr(S, ExprArg(*this, CE), LParenLoc, 6612 MultiExprArg(*this, (ExprTy**)Args, NumArgs), 6613 CommaLocs, RParenLoc).result(); 6614 } 6615 6616 CheckMemberOperatorAccess(LParenLoc, Object, 0, Best->FoundDecl); 6617 6618 // We found an overloaded operator(). Build a CXXOperatorCallExpr 6619 // that calls this method, using Object for the implicit object 6620 // parameter and passing along the remaining arguments. 6621 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 6622 const FunctionProtoType *Proto = Method->getType()->getAs<FunctionProtoType>(); 6623 6624 unsigned NumArgsInProto = Proto->getNumArgs(); 6625 unsigned NumArgsToCheck = NumArgs; 6626 6627 // Build the full argument list for the method call (the 6628 // implicit object parameter is placed at the beginning of the 6629 // list). 6630 Expr **MethodArgs; 6631 if (NumArgs < NumArgsInProto) { 6632 NumArgsToCheck = NumArgsInProto; 6633 MethodArgs = new Expr*[NumArgsInProto + 1]; 6634 } else { 6635 MethodArgs = new Expr*[NumArgs + 1]; 6636 } 6637 MethodArgs[0] = Object; 6638 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 6639 MethodArgs[ArgIdx + 1] = Args[ArgIdx]; 6640 6641 Expr *NewFn = new (Context) DeclRefExpr(Method, Method->getType(), 6642 SourceLocation()); 6643 UsualUnaryConversions(NewFn); 6644 6645 // Once we've built TheCall, all of the expressions are properly 6646 // owned. 6647 QualType ResultTy = Method->getResultType().getNonReferenceType(); 6648 ExprOwningPtr<CXXOperatorCallExpr> 6649 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Call, NewFn, 6650 MethodArgs, NumArgs + 1, 6651 ResultTy, RParenLoc)); 6652 delete [] MethodArgs; 6653 6654 if (CheckCallReturnType(Method->getResultType(), LParenLoc, TheCall.get(), 6655 Method)) 6656 return true; 6657 6658 // We may have default arguments. If so, we need to allocate more 6659 // slots in the call for them. 6660 if (NumArgs < NumArgsInProto) 6661 TheCall->setNumArgs(Context, NumArgsInProto + 1); 6662 else if (NumArgs > NumArgsInProto) 6663 NumArgsToCheck = NumArgsInProto; 6664 6665 bool IsError = false; 6666 6667 // Initialize the implicit object parameter. 6668 IsError |= PerformObjectArgumentInitialization(Object, /*Qualifier=*/0, 6669 Best->FoundDecl, Method); 6670 TheCall->setArg(0, Object); 6671 6672 6673 // Check the argument types. 6674 for (unsigned i = 0; i != NumArgsToCheck; i++) { 6675 Expr *Arg; 6676 if (i < NumArgs) { 6677 Arg = Args[i]; 6678 6679 // Pass the argument. 6680 6681 OwningExprResult InputInit 6682 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 6683 Method->getParamDecl(i)), 6684 SourceLocation(), Owned(Arg)); 6685 6686 IsError |= InputInit.isInvalid(); 6687 Arg = InputInit.takeAs<Expr>(); 6688 } else { 6689 OwningExprResult DefArg 6690 = BuildCXXDefaultArgExpr(LParenLoc, Method, Method->getParamDecl(i)); 6691 if (DefArg.isInvalid()) { 6692 IsError = true; 6693 break; 6694 } 6695 6696 Arg = DefArg.takeAs<Expr>(); 6697 } 6698 6699 TheCall->setArg(i + 1, Arg); 6700 } 6701 6702 // If this is a variadic call, handle args passed through "...". 6703 if (Proto->isVariadic()) { 6704 // Promote the arguments (C99 6.5.2.2p7). 6705 for (unsigned i = NumArgsInProto; i != NumArgs; i++) { 6706 Expr *Arg = Args[i]; 6707 IsError |= DefaultVariadicArgumentPromotion(Arg, VariadicMethod); 6708 TheCall->setArg(i + 1, Arg); 6709 } 6710 } 6711 6712 if (IsError) return true; 6713 6714 if (CheckFunctionCall(Method, TheCall.get())) 6715 return true; 6716 6717 return MaybeBindToTemporary(TheCall.release()).result(); 6718} 6719 6720/// BuildOverloadedArrowExpr - Build a call to an overloaded @c operator-> 6721/// (if one exists), where @c Base is an expression of class type and 6722/// @c Member is the name of the member we're trying to find. 6723Sema::OwningExprResult 6724Sema::BuildOverloadedArrowExpr(Scope *S, ExprArg BaseIn, SourceLocation OpLoc) { 6725 Expr *Base = static_cast<Expr *>(BaseIn.get()); 6726 assert(Base->getType()->isRecordType() && "left-hand side must have class type"); 6727 6728 SourceLocation Loc = Base->getExprLoc(); 6729 6730 // C++ [over.ref]p1: 6731 // 6732 // [...] An expression x->m is interpreted as (x.operator->())->m 6733 // for a class object x of type T if T::operator->() exists and if 6734 // the operator is selected as the best match function by the 6735 // overload resolution mechanism (13.3). 6736 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Arrow); 6737 OverloadCandidateSet CandidateSet(Loc); 6738 const RecordType *BaseRecord = Base->getType()->getAs<RecordType>(); 6739 6740 if (RequireCompleteType(Loc, Base->getType(), 6741 PDiag(diag::err_typecheck_incomplete_tag) 6742 << Base->getSourceRange())) 6743 return ExprError(); 6744 6745 LookupResult R(*this, OpName, OpLoc, LookupOrdinaryName); 6746 LookupQualifiedName(R, BaseRecord->getDecl()); 6747 R.suppressDiagnostics(); 6748 6749 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 6750 Oper != OperEnd; ++Oper) { 6751 AddMethodCandidate(Oper.getPair(), Base->getType(), 0, 0, CandidateSet, 6752 /*SuppressUserConversions=*/false); 6753 } 6754 6755 // Perform overload resolution. 6756 OverloadCandidateSet::iterator Best; 6757 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 6758 case OR_Success: 6759 // Overload resolution succeeded; we'll build the call below. 6760 break; 6761 6762 case OR_No_Viable_Function: 6763 if (CandidateSet.empty()) 6764 Diag(OpLoc, diag::err_typecheck_member_reference_arrow) 6765 << Base->getType() << Base->getSourceRange(); 6766 else 6767 Diag(OpLoc, diag::err_ovl_no_viable_oper) 6768 << "operator->" << Base->getSourceRange(); 6769 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, &Base, 1); 6770 return ExprError(); 6771 6772 case OR_Ambiguous: 6773 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 6774 << "->" << Base->getSourceRange(); 6775 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, &Base, 1); 6776 return ExprError(); 6777 6778 case OR_Deleted: 6779 Diag(OpLoc, diag::err_ovl_deleted_oper) 6780 << Best->Function->isDeleted() 6781 << "->" << Base->getSourceRange(); 6782 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, &Base, 1); 6783 return ExprError(); 6784 } 6785 6786 CheckMemberOperatorAccess(OpLoc, Base, 0, Best->FoundDecl); 6787 6788 // Convert the object parameter. 6789 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 6790 if (PerformObjectArgumentInitialization(Base, /*Qualifier=*/0, 6791 Best->FoundDecl, Method)) 6792 return ExprError(); 6793 6794 // No concerns about early exits now. 6795 BaseIn.release(); 6796 6797 // Build the operator call. 6798 Expr *FnExpr = new (Context) DeclRefExpr(Method, Method->getType(), 6799 SourceLocation()); 6800 UsualUnaryConversions(FnExpr); 6801 6802 QualType ResultTy = Method->getResultType().getNonReferenceType(); 6803 ExprOwningPtr<CXXOperatorCallExpr> 6804 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Arrow, FnExpr, 6805 &Base, 1, ResultTy, OpLoc)); 6806 6807 if (CheckCallReturnType(Method->getResultType(), OpLoc, TheCall.get(), 6808 Method)) 6809 return ExprError(); 6810 return move(TheCall); 6811} 6812 6813/// FixOverloadedFunctionReference - E is an expression that refers to 6814/// a C++ overloaded function (possibly with some parentheses and 6815/// perhaps a '&' around it). We have resolved the overloaded function 6816/// to the function declaration Fn, so patch up the expression E to 6817/// refer (possibly indirectly) to Fn. Returns the new expr. 6818Expr *Sema::FixOverloadedFunctionReference(Expr *E, DeclAccessPair Found, 6819 FunctionDecl *Fn) { 6820 if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) { 6821 Expr *SubExpr = FixOverloadedFunctionReference(PE->getSubExpr(), 6822 Found, Fn); 6823 if (SubExpr == PE->getSubExpr()) 6824 return PE->Retain(); 6825 6826 return new (Context) ParenExpr(PE->getLParen(), PE->getRParen(), SubExpr); 6827 } 6828 6829 if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) { 6830 Expr *SubExpr = FixOverloadedFunctionReference(ICE->getSubExpr(), 6831 Found, Fn); 6832 assert(Context.hasSameType(ICE->getSubExpr()->getType(), 6833 SubExpr->getType()) && 6834 "Implicit cast type cannot be determined from overload"); 6835 if (SubExpr == ICE->getSubExpr()) 6836 return ICE->Retain(); 6837 6838 return new (Context) ImplicitCastExpr(ICE->getType(), 6839 ICE->getCastKind(), 6840 SubExpr, 6841 ICE->isLvalueCast()); 6842 } 6843 6844 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(E)) { 6845 assert(UnOp->getOpcode() == UnaryOperator::AddrOf && 6846 "Can only take the address of an overloaded function"); 6847 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 6848 if (Method->isStatic()) { 6849 // Do nothing: static member functions aren't any different 6850 // from non-member functions. 6851 } else { 6852 // Fix the sub expression, which really has to be an 6853 // UnresolvedLookupExpr holding an overloaded member function 6854 // or template. 6855 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(), 6856 Found, Fn); 6857 if (SubExpr == UnOp->getSubExpr()) 6858 return UnOp->Retain(); 6859 6860 assert(isa<DeclRefExpr>(SubExpr) 6861 && "fixed to something other than a decl ref"); 6862 assert(cast<DeclRefExpr>(SubExpr)->getQualifier() 6863 && "fixed to a member ref with no nested name qualifier"); 6864 6865 // We have taken the address of a pointer to member 6866 // function. Perform the computation here so that we get the 6867 // appropriate pointer to member type. 6868 QualType ClassType 6869 = Context.getTypeDeclType(cast<RecordDecl>(Method->getDeclContext())); 6870 QualType MemPtrType 6871 = Context.getMemberPointerType(Fn->getType(), ClassType.getTypePtr()); 6872 6873 return new (Context) UnaryOperator(SubExpr, UnaryOperator::AddrOf, 6874 MemPtrType, UnOp->getOperatorLoc()); 6875 } 6876 } 6877 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(), 6878 Found, Fn); 6879 if (SubExpr == UnOp->getSubExpr()) 6880 return UnOp->Retain(); 6881 6882 return new (Context) UnaryOperator(SubExpr, UnaryOperator::AddrOf, 6883 Context.getPointerType(SubExpr->getType()), 6884 UnOp->getOperatorLoc()); 6885 } 6886 6887 if (UnresolvedLookupExpr *ULE = dyn_cast<UnresolvedLookupExpr>(E)) { 6888 // FIXME: avoid copy. 6889 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 6890 if (ULE->hasExplicitTemplateArgs()) { 6891 ULE->copyTemplateArgumentsInto(TemplateArgsBuffer); 6892 TemplateArgs = &TemplateArgsBuffer; 6893 } 6894 6895 return DeclRefExpr::Create(Context, 6896 ULE->getQualifier(), 6897 ULE->getQualifierRange(), 6898 Fn, 6899 ULE->getNameLoc(), 6900 Fn->getType(), 6901 TemplateArgs); 6902 } 6903 6904 if (UnresolvedMemberExpr *MemExpr = dyn_cast<UnresolvedMemberExpr>(E)) { 6905 // FIXME: avoid copy. 6906 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 6907 if (MemExpr->hasExplicitTemplateArgs()) { 6908 MemExpr->copyTemplateArgumentsInto(TemplateArgsBuffer); 6909 TemplateArgs = &TemplateArgsBuffer; 6910 } 6911 6912 Expr *Base; 6913 6914 // If we're filling in 6915 if (MemExpr->isImplicitAccess()) { 6916 if (cast<CXXMethodDecl>(Fn)->isStatic()) { 6917 return DeclRefExpr::Create(Context, 6918 MemExpr->getQualifier(), 6919 MemExpr->getQualifierRange(), 6920 Fn, 6921 MemExpr->getMemberLoc(), 6922 Fn->getType(), 6923 TemplateArgs); 6924 } else { 6925 SourceLocation Loc = MemExpr->getMemberLoc(); 6926 if (MemExpr->getQualifier()) 6927 Loc = MemExpr->getQualifierRange().getBegin(); 6928 Base = new (Context) CXXThisExpr(Loc, 6929 MemExpr->getBaseType(), 6930 /*isImplicit=*/true); 6931 } 6932 } else 6933 Base = MemExpr->getBase()->Retain(); 6934 6935 return MemberExpr::Create(Context, Base, 6936 MemExpr->isArrow(), 6937 MemExpr->getQualifier(), 6938 MemExpr->getQualifierRange(), 6939 Fn, 6940 Found, 6941 MemExpr->getMemberLoc(), 6942 TemplateArgs, 6943 Fn->getType()); 6944 } 6945 6946 assert(false && "Invalid reference to overloaded function"); 6947 return E->Retain(); 6948} 6949 6950Sema::OwningExprResult Sema::FixOverloadedFunctionReference(OwningExprResult E, 6951 DeclAccessPair Found, 6952 FunctionDecl *Fn) { 6953 return Owned(FixOverloadedFunctionReference((Expr *)E.get(), Found, Fn)); 6954} 6955 6956} // end namespace clang 6957