SemaOverload.cpp revision 890f18a7faddc345128f3e081f1d08283f3ab58c
1//===--- SemaOverload.cpp - C++ Overloading ---------------------*- C++ -*-===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This file provides Sema routines for C++ overloading. 11// 12//===----------------------------------------------------------------------===// 13 14#include "Sema.h" 15#include "Lookup.h" 16#include "SemaInit.h" 17#include "clang/Basic/Diagnostic.h" 18#include "clang/Lex/Preprocessor.h" 19#include "clang/AST/ASTContext.h" 20#include "clang/AST/CXXInheritance.h" 21#include "clang/AST/Expr.h" 22#include "clang/AST/ExprCXX.h" 23#include "clang/AST/TypeOrdering.h" 24#include "clang/Basic/PartialDiagnostic.h" 25#include "llvm/ADT/SmallPtrSet.h" 26#include "llvm/ADT/STLExtras.h" 27#include <algorithm> 28 29namespace clang { 30 31/// GetConversionCategory - Retrieve the implicit conversion 32/// category corresponding to the given implicit conversion kind. 33ImplicitConversionCategory 34GetConversionCategory(ImplicitConversionKind Kind) { 35 static const ImplicitConversionCategory 36 Category[(int)ICK_Num_Conversion_Kinds] = { 37 ICC_Identity, 38 ICC_Lvalue_Transformation, 39 ICC_Lvalue_Transformation, 40 ICC_Lvalue_Transformation, 41 ICC_Identity, 42 ICC_Qualification_Adjustment, 43 ICC_Promotion, 44 ICC_Promotion, 45 ICC_Promotion, 46 ICC_Conversion, 47 ICC_Conversion, 48 ICC_Conversion, 49 ICC_Conversion, 50 ICC_Conversion, 51 ICC_Conversion, 52 ICC_Conversion, 53 ICC_Conversion, 54 ICC_Conversion, 55 ICC_Conversion 56 }; 57 return Category[(int)Kind]; 58} 59 60/// GetConversionRank - Retrieve the implicit conversion rank 61/// corresponding to the given implicit conversion kind. 62ImplicitConversionRank GetConversionRank(ImplicitConversionKind Kind) { 63 static const ImplicitConversionRank 64 Rank[(int)ICK_Num_Conversion_Kinds] = { 65 ICR_Exact_Match, 66 ICR_Exact_Match, 67 ICR_Exact_Match, 68 ICR_Exact_Match, 69 ICR_Exact_Match, 70 ICR_Exact_Match, 71 ICR_Promotion, 72 ICR_Promotion, 73 ICR_Promotion, 74 ICR_Conversion, 75 ICR_Conversion, 76 ICR_Conversion, 77 ICR_Conversion, 78 ICR_Conversion, 79 ICR_Conversion, 80 ICR_Conversion, 81 ICR_Conversion, 82 ICR_Conversion, 83 ICR_Complex_Real_Conversion 84 }; 85 return Rank[(int)Kind]; 86} 87 88/// GetImplicitConversionName - Return the name of this kind of 89/// implicit conversion. 90const char* GetImplicitConversionName(ImplicitConversionKind Kind) { 91 static const char* const Name[(int)ICK_Num_Conversion_Kinds] = { 92 "No conversion", 93 "Lvalue-to-rvalue", 94 "Array-to-pointer", 95 "Function-to-pointer", 96 "Noreturn adjustment", 97 "Qualification", 98 "Integral promotion", 99 "Floating point promotion", 100 "Complex promotion", 101 "Integral conversion", 102 "Floating conversion", 103 "Complex conversion", 104 "Floating-integral conversion", 105 "Complex-real conversion", 106 "Pointer conversion", 107 "Pointer-to-member conversion", 108 "Boolean conversion", 109 "Compatible-types conversion", 110 "Derived-to-base conversion" 111 }; 112 return Name[Kind]; 113} 114 115/// StandardConversionSequence - Set the standard conversion 116/// sequence to the identity conversion. 117void StandardConversionSequence::setAsIdentityConversion() { 118 First = ICK_Identity; 119 Second = ICK_Identity; 120 Third = ICK_Identity; 121 DeprecatedStringLiteralToCharPtr = false; 122 ReferenceBinding = false; 123 DirectBinding = false; 124 RRefBinding = false; 125 CopyConstructor = 0; 126} 127 128/// getRank - Retrieve the rank of this standard conversion sequence 129/// (C++ 13.3.3.1.1p3). The rank is the largest rank of each of the 130/// implicit conversions. 131ImplicitConversionRank StandardConversionSequence::getRank() const { 132 ImplicitConversionRank Rank = ICR_Exact_Match; 133 if (GetConversionRank(First) > Rank) 134 Rank = GetConversionRank(First); 135 if (GetConversionRank(Second) > Rank) 136 Rank = GetConversionRank(Second); 137 if (GetConversionRank(Third) > Rank) 138 Rank = GetConversionRank(Third); 139 return Rank; 140} 141 142/// isPointerConversionToBool - Determines whether this conversion is 143/// a conversion of a pointer or pointer-to-member to bool. This is 144/// used as part of the ranking of standard conversion sequences 145/// (C++ 13.3.3.2p4). 146bool StandardConversionSequence::isPointerConversionToBool() const { 147 // Note that FromType has not necessarily been transformed by the 148 // array-to-pointer or function-to-pointer implicit conversions, so 149 // check for their presence as well as checking whether FromType is 150 // a pointer. 151 if (getToType(1)->isBooleanType() && 152 (getFromType()->isPointerType() || getFromType()->isBlockPointerType() || 153 First == ICK_Array_To_Pointer || First == ICK_Function_To_Pointer)) 154 return true; 155 156 return false; 157} 158 159/// isPointerConversionToVoidPointer - Determines whether this 160/// conversion is a conversion of a pointer to a void pointer. This is 161/// used as part of the ranking of standard conversion sequences (C++ 162/// 13.3.3.2p4). 163bool 164StandardConversionSequence:: 165isPointerConversionToVoidPointer(ASTContext& Context) const { 166 QualType FromType = getFromType(); 167 QualType ToType = getToType(1); 168 169 // Note that FromType has not necessarily been transformed by the 170 // array-to-pointer implicit conversion, so check for its presence 171 // and redo the conversion to get a pointer. 172 if (First == ICK_Array_To_Pointer) 173 FromType = Context.getArrayDecayedType(FromType); 174 175 if (Second == ICK_Pointer_Conversion && FromType->isPointerType()) 176 if (const PointerType* ToPtrType = ToType->getAs<PointerType>()) 177 return ToPtrType->getPointeeType()->isVoidType(); 178 179 return false; 180} 181 182/// DebugPrint - Print this standard conversion sequence to standard 183/// error. Useful for debugging overloading issues. 184void StandardConversionSequence::DebugPrint() const { 185 llvm::raw_ostream &OS = llvm::errs(); 186 bool PrintedSomething = false; 187 if (First != ICK_Identity) { 188 OS << GetImplicitConversionName(First); 189 PrintedSomething = true; 190 } 191 192 if (Second != ICK_Identity) { 193 if (PrintedSomething) { 194 OS << " -> "; 195 } 196 OS << GetImplicitConversionName(Second); 197 198 if (CopyConstructor) { 199 OS << " (by copy constructor)"; 200 } else if (DirectBinding) { 201 OS << " (direct reference binding)"; 202 } else if (ReferenceBinding) { 203 OS << " (reference binding)"; 204 } 205 PrintedSomething = true; 206 } 207 208 if (Third != ICK_Identity) { 209 if (PrintedSomething) { 210 OS << " -> "; 211 } 212 OS << GetImplicitConversionName(Third); 213 PrintedSomething = true; 214 } 215 216 if (!PrintedSomething) { 217 OS << "No conversions required"; 218 } 219} 220 221/// DebugPrint - Print this user-defined conversion sequence to standard 222/// error. Useful for debugging overloading issues. 223void UserDefinedConversionSequence::DebugPrint() const { 224 llvm::raw_ostream &OS = llvm::errs(); 225 if (Before.First || Before.Second || Before.Third) { 226 Before.DebugPrint(); 227 OS << " -> "; 228 } 229 OS << "'" << ConversionFunction->getNameAsString() << "'"; 230 if (After.First || After.Second || After.Third) { 231 OS << " -> "; 232 After.DebugPrint(); 233 } 234} 235 236/// DebugPrint - Print this implicit conversion sequence to standard 237/// error. Useful for debugging overloading issues. 238void ImplicitConversionSequence::DebugPrint() const { 239 llvm::raw_ostream &OS = llvm::errs(); 240 switch (ConversionKind) { 241 case StandardConversion: 242 OS << "Standard conversion: "; 243 Standard.DebugPrint(); 244 break; 245 case UserDefinedConversion: 246 OS << "User-defined conversion: "; 247 UserDefined.DebugPrint(); 248 break; 249 case EllipsisConversion: 250 OS << "Ellipsis conversion"; 251 break; 252 case AmbiguousConversion: 253 OS << "Ambiguous conversion"; 254 break; 255 case BadConversion: 256 OS << "Bad conversion"; 257 break; 258 } 259 260 OS << "\n"; 261} 262 263void AmbiguousConversionSequence::construct() { 264 new (&conversions()) ConversionSet(); 265} 266 267void AmbiguousConversionSequence::destruct() { 268 conversions().~ConversionSet(); 269} 270 271void 272AmbiguousConversionSequence::copyFrom(const AmbiguousConversionSequence &O) { 273 FromTypePtr = O.FromTypePtr; 274 ToTypePtr = O.ToTypePtr; 275 new (&conversions()) ConversionSet(O.conversions()); 276} 277 278 279// IsOverload - Determine whether the given New declaration is an 280// overload of the declarations in Old. This routine returns false if 281// New and Old cannot be overloaded, e.g., if New has the same 282// signature as some function in Old (C++ 1.3.10) or if the Old 283// declarations aren't functions (or function templates) at all. When 284// it does return false, MatchedDecl will point to the decl that New 285// cannot be overloaded with. This decl may be a UsingShadowDecl on 286// top of the underlying declaration. 287// 288// Example: Given the following input: 289// 290// void f(int, float); // #1 291// void f(int, int); // #2 292// int f(int, int); // #3 293// 294// When we process #1, there is no previous declaration of "f", 295// so IsOverload will not be used. 296// 297// When we process #2, Old contains only the FunctionDecl for #1. By 298// comparing the parameter types, we see that #1 and #2 are overloaded 299// (since they have different signatures), so this routine returns 300// false; MatchedDecl is unchanged. 301// 302// When we process #3, Old is an overload set containing #1 and #2. We 303// compare the signatures of #3 to #1 (they're overloaded, so we do 304// nothing) and then #3 to #2. Since the signatures of #3 and #2 are 305// identical (return types of functions are not part of the 306// signature), IsOverload returns false and MatchedDecl will be set to 307// point to the FunctionDecl for #2. 308Sema::OverloadKind 309Sema::CheckOverload(FunctionDecl *New, const LookupResult &Old, 310 NamedDecl *&Match) { 311 for (LookupResult::iterator I = Old.begin(), E = Old.end(); 312 I != E; ++I) { 313 NamedDecl *OldD = (*I)->getUnderlyingDecl(); 314 if (FunctionTemplateDecl *OldT = dyn_cast<FunctionTemplateDecl>(OldD)) { 315 if (!IsOverload(New, OldT->getTemplatedDecl())) { 316 Match = *I; 317 return Ovl_Match; 318 } 319 } else if (FunctionDecl *OldF = dyn_cast<FunctionDecl>(OldD)) { 320 if (!IsOverload(New, OldF)) { 321 Match = *I; 322 return Ovl_Match; 323 } 324 } else if (isa<UsingDecl>(OldD) || isa<TagDecl>(OldD)) { 325 // We can overload with these, which can show up when doing 326 // redeclaration checks for UsingDecls. 327 assert(Old.getLookupKind() == LookupUsingDeclName); 328 } else if (isa<UnresolvedUsingValueDecl>(OldD)) { 329 // Optimistically assume that an unresolved using decl will 330 // overload; if it doesn't, we'll have to diagnose during 331 // template instantiation. 332 } else { 333 // (C++ 13p1): 334 // Only function declarations can be overloaded; object and type 335 // declarations cannot be overloaded. 336 Match = *I; 337 return Ovl_NonFunction; 338 } 339 } 340 341 return Ovl_Overload; 342} 343 344bool Sema::IsOverload(FunctionDecl *New, FunctionDecl *Old) { 345 FunctionTemplateDecl *OldTemplate = Old->getDescribedFunctionTemplate(); 346 FunctionTemplateDecl *NewTemplate = New->getDescribedFunctionTemplate(); 347 348 // C++ [temp.fct]p2: 349 // A function template can be overloaded with other function templates 350 // and with normal (non-template) functions. 351 if ((OldTemplate == 0) != (NewTemplate == 0)) 352 return true; 353 354 // Is the function New an overload of the function Old? 355 QualType OldQType = Context.getCanonicalType(Old->getType()); 356 QualType NewQType = Context.getCanonicalType(New->getType()); 357 358 // Compare the signatures (C++ 1.3.10) of the two functions to 359 // determine whether they are overloads. If we find any mismatch 360 // in the signature, they are overloads. 361 362 // If either of these functions is a K&R-style function (no 363 // prototype), then we consider them to have matching signatures. 364 if (isa<FunctionNoProtoType>(OldQType.getTypePtr()) || 365 isa<FunctionNoProtoType>(NewQType.getTypePtr())) 366 return false; 367 368 FunctionProtoType* OldType = cast<FunctionProtoType>(OldQType); 369 FunctionProtoType* NewType = cast<FunctionProtoType>(NewQType); 370 371 // The signature of a function includes the types of its 372 // parameters (C++ 1.3.10), which includes the presence or absence 373 // of the ellipsis; see C++ DR 357). 374 if (OldQType != NewQType && 375 (OldType->getNumArgs() != NewType->getNumArgs() || 376 OldType->isVariadic() != NewType->isVariadic() || 377 !std::equal(OldType->arg_type_begin(), OldType->arg_type_end(), 378 NewType->arg_type_begin()))) 379 return true; 380 381 // C++ [temp.over.link]p4: 382 // The signature of a function template consists of its function 383 // signature, its return type and its template parameter list. The names 384 // of the template parameters are significant only for establishing the 385 // relationship between the template parameters and the rest of the 386 // signature. 387 // 388 // We check the return type and template parameter lists for function 389 // templates first; the remaining checks follow. 390 if (NewTemplate && 391 (!TemplateParameterListsAreEqual(NewTemplate->getTemplateParameters(), 392 OldTemplate->getTemplateParameters(), 393 false, TPL_TemplateMatch) || 394 OldType->getResultType() != NewType->getResultType())) 395 return true; 396 397 // If the function is a class member, its signature includes the 398 // cv-qualifiers (if any) on the function itself. 399 // 400 // As part of this, also check whether one of the member functions 401 // is static, in which case they are not overloads (C++ 402 // 13.1p2). While not part of the definition of the signature, 403 // this check is important to determine whether these functions 404 // can be overloaded. 405 CXXMethodDecl* OldMethod = dyn_cast<CXXMethodDecl>(Old); 406 CXXMethodDecl* NewMethod = dyn_cast<CXXMethodDecl>(New); 407 if (OldMethod && NewMethod && 408 !OldMethod->isStatic() && !NewMethod->isStatic() && 409 OldMethod->getTypeQualifiers() != NewMethod->getTypeQualifiers()) 410 return true; 411 412 // The signatures match; this is not an overload. 413 return false; 414} 415 416/// TryImplicitConversion - Attempt to perform an implicit conversion 417/// from the given expression (Expr) to the given type (ToType). This 418/// function returns an implicit conversion sequence that can be used 419/// to perform the initialization. Given 420/// 421/// void f(float f); 422/// void g(int i) { f(i); } 423/// 424/// this routine would produce an implicit conversion sequence to 425/// describe the initialization of f from i, which will be a standard 426/// conversion sequence containing an lvalue-to-rvalue conversion (C++ 427/// 4.1) followed by a floating-integral conversion (C++ 4.9). 428// 429/// Note that this routine only determines how the conversion can be 430/// performed; it does not actually perform the conversion. As such, 431/// it will not produce any diagnostics if no conversion is available, 432/// but will instead return an implicit conversion sequence of kind 433/// "BadConversion". 434/// 435/// If @p SuppressUserConversions, then user-defined conversions are 436/// not permitted. 437/// If @p AllowExplicit, then explicit user-defined conversions are 438/// permitted. 439/// If @p ForceRValue, then overloading is performed as if From was an rvalue, 440/// no matter its actual lvalueness. 441/// If @p UserCast, the implicit conversion is being done for a user-specified 442/// cast. 443ImplicitConversionSequence 444Sema::TryImplicitConversion(Expr* From, QualType ToType, 445 bool SuppressUserConversions, 446 bool AllowExplicit, bool ForceRValue, 447 bool InOverloadResolution, 448 bool UserCast) { 449 ImplicitConversionSequence ICS; 450 if (IsStandardConversion(From, ToType, InOverloadResolution, ICS.Standard)) { 451 ICS.setStandard(); 452 return ICS; 453 } 454 455 if (!getLangOptions().CPlusPlus) { 456 ICS.setBad(BadConversionSequence::no_conversion, From, ToType); 457 return ICS; 458 } 459 460 OverloadCandidateSet Conversions(From->getExprLoc()); 461 OverloadingResult UserDefResult 462 = IsUserDefinedConversion(From, ToType, ICS.UserDefined, Conversions, 463 !SuppressUserConversions, AllowExplicit, 464 UserCast); 465 466 if (UserDefResult == OR_Success) { 467 ICS.setUserDefined(); 468 // C++ [over.ics.user]p4: 469 // A conversion of an expression of class type to the same class 470 // type is given Exact Match rank, and a conversion of an 471 // expression of class type to a base class of that type is 472 // given Conversion rank, in spite of the fact that a copy 473 // constructor (i.e., a user-defined conversion function) is 474 // called for those cases. 475 if (CXXConstructorDecl *Constructor 476 = dyn_cast<CXXConstructorDecl>(ICS.UserDefined.ConversionFunction)) { 477 QualType FromCanon 478 = Context.getCanonicalType(From->getType().getUnqualifiedType()); 479 QualType ToCanon = Context.getCanonicalType(ToType).getUnqualifiedType(); 480 if (Constructor->isCopyConstructor() && 481 (FromCanon == ToCanon || IsDerivedFrom(FromCanon, ToCanon))) { 482 // Turn this into a "standard" conversion sequence, so that it 483 // gets ranked with standard conversion sequences. 484 ICS.setStandard(); 485 ICS.Standard.setAsIdentityConversion(); 486 ICS.Standard.setFromType(From->getType()); 487 ICS.Standard.setAllToTypes(ToType); 488 ICS.Standard.CopyConstructor = Constructor; 489 if (ToCanon != FromCanon) 490 ICS.Standard.Second = ICK_Derived_To_Base; 491 } 492 } 493 494 // C++ [over.best.ics]p4: 495 // However, when considering the argument of a user-defined 496 // conversion function that is a candidate by 13.3.1.3 when 497 // invoked for the copying of the temporary in the second step 498 // of a class copy-initialization, or by 13.3.1.4, 13.3.1.5, or 499 // 13.3.1.6 in all cases, only standard conversion sequences and 500 // ellipsis conversion sequences are allowed. 501 if (SuppressUserConversions && ICS.isUserDefined()) { 502 ICS.setBad(BadConversionSequence::suppressed_user, From, ToType); 503 } 504 } else if (UserDefResult == OR_Ambiguous && !SuppressUserConversions) { 505 ICS.setAmbiguous(); 506 ICS.Ambiguous.setFromType(From->getType()); 507 ICS.Ambiguous.setToType(ToType); 508 for (OverloadCandidateSet::iterator Cand = Conversions.begin(); 509 Cand != Conversions.end(); ++Cand) 510 if (Cand->Viable) 511 ICS.Ambiguous.addConversion(Cand->Function); 512 } else { 513 ICS.setBad(BadConversionSequence::no_conversion, From, ToType); 514 } 515 516 return ICS; 517} 518 519/// \brief Determine whether the conversion from FromType to ToType is a valid 520/// conversion that strips "noreturn" off the nested function type. 521static bool IsNoReturnConversion(ASTContext &Context, QualType FromType, 522 QualType ToType, QualType &ResultTy) { 523 if (Context.hasSameUnqualifiedType(FromType, ToType)) 524 return false; 525 526 // Strip the noreturn off the type we're converting from; noreturn can 527 // safely be removed. 528 FromType = Context.getNoReturnType(FromType, false); 529 if (!Context.hasSameUnqualifiedType(FromType, ToType)) 530 return false; 531 532 ResultTy = FromType; 533 return true; 534} 535 536/// IsStandardConversion - Determines whether there is a standard 537/// conversion sequence (C++ [conv], C++ [over.ics.scs]) from the 538/// expression From to the type ToType. Standard conversion sequences 539/// only consider non-class types; for conversions that involve class 540/// types, use TryImplicitConversion. If a conversion exists, SCS will 541/// contain the standard conversion sequence required to perform this 542/// conversion and this routine will return true. Otherwise, this 543/// routine will return false and the value of SCS is unspecified. 544bool 545Sema::IsStandardConversion(Expr* From, QualType ToType, 546 bool InOverloadResolution, 547 StandardConversionSequence &SCS) { 548 QualType FromType = From->getType(); 549 550 // Standard conversions (C++ [conv]) 551 SCS.setAsIdentityConversion(); 552 SCS.DeprecatedStringLiteralToCharPtr = false; 553 SCS.IncompatibleObjC = false; 554 SCS.setFromType(FromType); 555 SCS.CopyConstructor = 0; 556 557 // There are no standard conversions for class types in C++, so 558 // abort early. When overloading in C, however, we do permit 559 if (FromType->isRecordType() || ToType->isRecordType()) { 560 if (getLangOptions().CPlusPlus) 561 return false; 562 563 // When we're overloading in C, we allow, as standard conversions, 564 } 565 566 // The first conversion can be an lvalue-to-rvalue conversion, 567 // array-to-pointer conversion, or function-to-pointer conversion 568 // (C++ 4p1). 569 570 DeclAccessPair AccessPair; 571 572 // Lvalue-to-rvalue conversion (C++ 4.1): 573 // An lvalue (3.10) of a non-function, non-array type T can be 574 // converted to an rvalue. 575 Expr::isLvalueResult argIsLvalue = From->isLvalue(Context); 576 if (argIsLvalue == Expr::LV_Valid && 577 !FromType->isFunctionType() && !FromType->isArrayType() && 578 Context.getCanonicalType(FromType) != Context.OverloadTy) { 579 SCS.First = ICK_Lvalue_To_Rvalue; 580 581 // If T is a non-class type, the type of the rvalue is the 582 // cv-unqualified version of T. Otherwise, the type of the rvalue 583 // is T (C++ 4.1p1). C++ can't get here with class types; in C, we 584 // just strip the qualifiers because they don't matter. 585 FromType = FromType.getUnqualifiedType(); 586 } else if (FromType->isArrayType()) { 587 // Array-to-pointer conversion (C++ 4.2) 588 SCS.First = ICK_Array_To_Pointer; 589 590 // An lvalue or rvalue of type "array of N T" or "array of unknown 591 // bound of T" can be converted to an rvalue of type "pointer to 592 // T" (C++ 4.2p1). 593 FromType = Context.getArrayDecayedType(FromType); 594 595 if (IsStringLiteralToNonConstPointerConversion(From, ToType)) { 596 // This conversion is deprecated. (C++ D.4). 597 SCS.DeprecatedStringLiteralToCharPtr = true; 598 599 // For the purpose of ranking in overload resolution 600 // (13.3.3.1.1), this conversion is considered an 601 // array-to-pointer conversion followed by a qualification 602 // conversion (4.4). (C++ 4.2p2) 603 SCS.Second = ICK_Identity; 604 SCS.Third = ICK_Qualification; 605 SCS.setAllToTypes(FromType); 606 return true; 607 } 608 } else if (FromType->isFunctionType() && argIsLvalue == Expr::LV_Valid) { 609 // Function-to-pointer conversion (C++ 4.3). 610 SCS.First = ICK_Function_To_Pointer; 611 612 // An lvalue of function type T can be converted to an rvalue of 613 // type "pointer to T." The result is a pointer to the 614 // function. (C++ 4.3p1). 615 FromType = Context.getPointerType(FromType); 616 } else if (From->getType() == Context.OverloadTy) { 617 if (FunctionDecl *Fn 618 = ResolveAddressOfOverloadedFunction(From, ToType, false, 619 AccessPair)) { 620 // Address of overloaded function (C++ [over.over]). 621 SCS.First = ICK_Function_To_Pointer; 622 623 // We were able to resolve the address of the overloaded function, 624 // so we can convert to the type of that function. 625 FromType = Fn->getType(); 626 if (ToType->isLValueReferenceType()) 627 FromType = Context.getLValueReferenceType(FromType); 628 else if (ToType->isRValueReferenceType()) 629 FromType = Context.getRValueReferenceType(FromType); 630 else if (ToType->isMemberPointerType()) { 631 // Resolve address only succeeds if both sides are member pointers, 632 // but it doesn't have to be the same class. See DR 247. 633 // Note that this means that the type of &Derived::fn can be 634 // Ret (Base::*)(Args) if the fn overload actually found is from the 635 // base class, even if it was brought into the derived class via a 636 // using declaration. The standard isn't clear on this issue at all. 637 CXXMethodDecl *M = cast<CXXMethodDecl>(Fn); 638 FromType = Context.getMemberPointerType(FromType, 639 Context.getTypeDeclType(M->getParent()).getTypePtr()); 640 } else { 641 FromType = Context.getPointerType(FromType); 642 } 643 } else { 644 return false; 645 } 646 } else { 647 // We don't require any conversions for the first step. 648 SCS.First = ICK_Identity; 649 } 650 SCS.setToType(0, FromType); 651 652 // The second conversion can be an integral promotion, floating 653 // point promotion, integral conversion, floating point conversion, 654 // floating-integral conversion, pointer conversion, 655 // pointer-to-member conversion, or boolean conversion (C++ 4p1). 656 // For overloading in C, this can also be a "compatible-type" 657 // conversion. 658 bool IncompatibleObjC = false; 659 if (Context.hasSameUnqualifiedType(FromType, ToType)) { 660 // The unqualified versions of the types are the same: there's no 661 // conversion to do. 662 SCS.Second = ICK_Identity; 663 } else if (IsIntegralPromotion(From, FromType, ToType)) { 664 // Integral promotion (C++ 4.5). 665 SCS.Second = ICK_Integral_Promotion; 666 FromType = ToType.getUnqualifiedType(); 667 } else if (IsFloatingPointPromotion(FromType, ToType)) { 668 // Floating point promotion (C++ 4.6). 669 SCS.Second = ICK_Floating_Promotion; 670 FromType = ToType.getUnqualifiedType(); 671 } else if (IsComplexPromotion(FromType, ToType)) { 672 // Complex promotion (Clang extension) 673 SCS.Second = ICK_Complex_Promotion; 674 FromType = ToType.getUnqualifiedType(); 675 } else if ((FromType->isIntegralType() || FromType->isEnumeralType()) && 676 (ToType->isIntegralType() && !ToType->isEnumeralType())) { 677 // Integral conversions (C++ 4.7). 678 SCS.Second = ICK_Integral_Conversion; 679 FromType = ToType.getUnqualifiedType(); 680 } else if (FromType->isComplexType() && ToType->isComplexType()) { 681 // Complex conversions (C99 6.3.1.6) 682 SCS.Second = ICK_Complex_Conversion; 683 FromType = ToType.getUnqualifiedType(); 684 } else if ((FromType->isComplexType() && ToType->isArithmeticType()) || 685 (ToType->isComplexType() && FromType->isArithmeticType())) { 686 // Complex-real conversions (C99 6.3.1.7) 687 SCS.Second = ICK_Complex_Real; 688 FromType = ToType.getUnqualifiedType(); 689 } else if (FromType->isFloatingType() && ToType->isFloatingType()) { 690 // Floating point conversions (C++ 4.8). 691 SCS.Second = ICK_Floating_Conversion; 692 FromType = ToType.getUnqualifiedType(); 693 } else if ((FromType->isFloatingType() && 694 ToType->isIntegralType() && (!ToType->isBooleanType() && 695 !ToType->isEnumeralType())) || 696 ((FromType->isIntegralType() || FromType->isEnumeralType()) && 697 ToType->isFloatingType())) { 698 // Floating-integral conversions (C++ 4.9). 699 SCS.Second = ICK_Floating_Integral; 700 FromType = ToType.getUnqualifiedType(); 701 } else if (IsPointerConversion(From, FromType, ToType, InOverloadResolution, 702 FromType, IncompatibleObjC)) { 703 // Pointer conversions (C++ 4.10). 704 SCS.Second = ICK_Pointer_Conversion; 705 SCS.IncompatibleObjC = IncompatibleObjC; 706 } else if (IsMemberPointerConversion(From, FromType, ToType, 707 InOverloadResolution, FromType)) { 708 // Pointer to member conversions (4.11). 709 SCS.Second = ICK_Pointer_Member; 710 } else if (ToType->isBooleanType() && 711 (FromType->isArithmeticType() || 712 FromType->isEnumeralType() || 713 FromType->isAnyPointerType() || 714 FromType->isBlockPointerType() || 715 FromType->isMemberPointerType() || 716 FromType->isNullPtrType())) { 717 // Boolean conversions (C++ 4.12). 718 SCS.Second = ICK_Boolean_Conversion; 719 FromType = Context.BoolTy; 720 } else if (!getLangOptions().CPlusPlus && 721 Context.typesAreCompatible(ToType, FromType)) { 722 // Compatible conversions (Clang extension for C function overloading) 723 SCS.Second = ICK_Compatible_Conversion; 724 } else if (IsNoReturnConversion(Context, FromType, ToType, FromType)) { 725 // Treat a conversion that strips "noreturn" as an identity conversion. 726 SCS.Second = ICK_NoReturn_Adjustment; 727 } else { 728 // No second conversion required. 729 SCS.Second = ICK_Identity; 730 } 731 SCS.setToType(1, FromType); 732 733 QualType CanonFrom; 734 QualType CanonTo; 735 // The third conversion can be a qualification conversion (C++ 4p1). 736 if (IsQualificationConversion(FromType, ToType)) { 737 SCS.Third = ICK_Qualification; 738 FromType = ToType; 739 CanonFrom = Context.getCanonicalType(FromType); 740 CanonTo = Context.getCanonicalType(ToType); 741 } else { 742 // No conversion required 743 SCS.Third = ICK_Identity; 744 745 // C++ [over.best.ics]p6: 746 // [...] Any difference in top-level cv-qualification is 747 // subsumed by the initialization itself and does not constitute 748 // a conversion. [...] 749 CanonFrom = Context.getCanonicalType(FromType); 750 CanonTo = Context.getCanonicalType(ToType); 751 if (CanonFrom.getLocalUnqualifiedType() 752 == CanonTo.getLocalUnqualifiedType() && 753 CanonFrom.getLocalCVRQualifiers() != CanonTo.getLocalCVRQualifiers()) { 754 FromType = ToType; 755 CanonFrom = CanonTo; 756 } 757 } 758 SCS.setToType(2, FromType); 759 760 // If we have not converted the argument type to the parameter type, 761 // this is a bad conversion sequence. 762 if (CanonFrom != CanonTo) 763 return false; 764 765 return true; 766} 767 768/// IsIntegralPromotion - Determines whether the conversion from the 769/// expression From (whose potentially-adjusted type is FromType) to 770/// ToType is an integral promotion (C++ 4.5). If so, returns true and 771/// sets PromotedType to the promoted type. 772bool Sema::IsIntegralPromotion(Expr *From, QualType FromType, QualType ToType) { 773 const BuiltinType *To = ToType->getAs<BuiltinType>(); 774 // All integers are built-in. 775 if (!To) { 776 return false; 777 } 778 779 // An rvalue of type char, signed char, unsigned char, short int, or 780 // unsigned short int can be converted to an rvalue of type int if 781 // int can represent all the values of the source type; otherwise, 782 // the source rvalue can be converted to an rvalue of type unsigned 783 // int (C++ 4.5p1). 784 if (FromType->isPromotableIntegerType() && !FromType->isBooleanType() && 785 !FromType->isEnumeralType()) { 786 if (// We can promote any signed, promotable integer type to an int 787 (FromType->isSignedIntegerType() || 788 // We can promote any unsigned integer type whose size is 789 // less than int to an int. 790 (!FromType->isSignedIntegerType() && 791 Context.getTypeSize(FromType) < Context.getTypeSize(ToType)))) { 792 return To->getKind() == BuiltinType::Int; 793 } 794 795 return To->getKind() == BuiltinType::UInt; 796 } 797 798 // An rvalue of type wchar_t (3.9.1) or an enumeration type (7.2) 799 // can be converted to an rvalue of the first of the following types 800 // that can represent all the values of its underlying type: int, 801 // unsigned int, long, or unsigned long (C++ 4.5p2). 802 803 // We pre-calculate the promotion type for enum types. 804 if (const EnumType *FromEnumType = FromType->getAs<EnumType>()) 805 if (ToType->isIntegerType()) 806 return Context.hasSameUnqualifiedType(ToType, 807 FromEnumType->getDecl()->getPromotionType()); 808 809 if (FromType->isWideCharType() && ToType->isIntegerType()) { 810 // Determine whether the type we're converting from is signed or 811 // unsigned. 812 bool FromIsSigned; 813 uint64_t FromSize = Context.getTypeSize(FromType); 814 815 // FIXME: Is wchar_t signed or unsigned? We assume it's signed for now. 816 FromIsSigned = true; 817 818 // The types we'll try to promote to, in the appropriate 819 // order. Try each of these types. 820 QualType PromoteTypes[6] = { 821 Context.IntTy, Context.UnsignedIntTy, 822 Context.LongTy, Context.UnsignedLongTy , 823 Context.LongLongTy, Context.UnsignedLongLongTy 824 }; 825 for (int Idx = 0; Idx < 6; ++Idx) { 826 uint64_t ToSize = Context.getTypeSize(PromoteTypes[Idx]); 827 if (FromSize < ToSize || 828 (FromSize == ToSize && 829 FromIsSigned == PromoteTypes[Idx]->isSignedIntegerType())) { 830 // We found the type that we can promote to. If this is the 831 // type we wanted, we have a promotion. Otherwise, no 832 // promotion. 833 return Context.hasSameUnqualifiedType(ToType, PromoteTypes[Idx]); 834 } 835 } 836 } 837 838 // An rvalue for an integral bit-field (9.6) can be converted to an 839 // rvalue of type int if int can represent all the values of the 840 // bit-field; otherwise, it can be converted to unsigned int if 841 // unsigned int can represent all the values of the bit-field. If 842 // the bit-field is larger yet, no integral promotion applies to 843 // it. If the bit-field has an enumerated type, it is treated as any 844 // other value of that type for promotion purposes (C++ 4.5p3). 845 // FIXME: We should delay checking of bit-fields until we actually perform the 846 // conversion. 847 using llvm::APSInt; 848 if (From) 849 if (FieldDecl *MemberDecl = From->getBitField()) { 850 APSInt BitWidth; 851 if (FromType->isIntegralType() && !FromType->isEnumeralType() && 852 MemberDecl->getBitWidth()->isIntegerConstantExpr(BitWidth, Context)) { 853 APSInt ToSize(BitWidth.getBitWidth(), BitWidth.isUnsigned()); 854 ToSize = Context.getTypeSize(ToType); 855 856 // Are we promoting to an int from a bitfield that fits in an int? 857 if (BitWidth < ToSize || 858 (FromType->isSignedIntegerType() && BitWidth <= ToSize)) { 859 return To->getKind() == BuiltinType::Int; 860 } 861 862 // Are we promoting to an unsigned int from an unsigned bitfield 863 // that fits into an unsigned int? 864 if (FromType->isUnsignedIntegerType() && BitWidth <= ToSize) { 865 return To->getKind() == BuiltinType::UInt; 866 } 867 868 return false; 869 } 870 } 871 872 // An rvalue of type bool can be converted to an rvalue of type int, 873 // with false becoming zero and true becoming one (C++ 4.5p4). 874 if (FromType->isBooleanType() && To->getKind() == BuiltinType::Int) { 875 return true; 876 } 877 878 return false; 879} 880 881/// IsFloatingPointPromotion - Determines whether the conversion from 882/// FromType to ToType is a floating point promotion (C++ 4.6). If so, 883/// returns true and sets PromotedType to the promoted type. 884bool Sema::IsFloatingPointPromotion(QualType FromType, QualType ToType) { 885 /// An rvalue of type float can be converted to an rvalue of type 886 /// double. (C++ 4.6p1). 887 if (const BuiltinType *FromBuiltin = FromType->getAs<BuiltinType>()) 888 if (const BuiltinType *ToBuiltin = ToType->getAs<BuiltinType>()) { 889 if (FromBuiltin->getKind() == BuiltinType::Float && 890 ToBuiltin->getKind() == BuiltinType::Double) 891 return true; 892 893 // C99 6.3.1.5p1: 894 // When a float is promoted to double or long double, or a 895 // double is promoted to long double [...]. 896 if (!getLangOptions().CPlusPlus && 897 (FromBuiltin->getKind() == BuiltinType::Float || 898 FromBuiltin->getKind() == BuiltinType::Double) && 899 (ToBuiltin->getKind() == BuiltinType::LongDouble)) 900 return true; 901 } 902 903 return false; 904} 905 906/// \brief Determine if a conversion is a complex promotion. 907/// 908/// A complex promotion is defined as a complex -> complex conversion 909/// where the conversion between the underlying real types is a 910/// floating-point or integral promotion. 911bool Sema::IsComplexPromotion(QualType FromType, QualType ToType) { 912 const ComplexType *FromComplex = FromType->getAs<ComplexType>(); 913 if (!FromComplex) 914 return false; 915 916 const ComplexType *ToComplex = ToType->getAs<ComplexType>(); 917 if (!ToComplex) 918 return false; 919 920 return IsFloatingPointPromotion(FromComplex->getElementType(), 921 ToComplex->getElementType()) || 922 IsIntegralPromotion(0, FromComplex->getElementType(), 923 ToComplex->getElementType()); 924} 925 926/// BuildSimilarlyQualifiedPointerType - In a pointer conversion from 927/// the pointer type FromPtr to a pointer to type ToPointee, with the 928/// same type qualifiers as FromPtr has on its pointee type. ToType, 929/// if non-empty, will be a pointer to ToType that may or may not have 930/// the right set of qualifiers on its pointee. 931static QualType 932BuildSimilarlyQualifiedPointerType(const PointerType *FromPtr, 933 QualType ToPointee, QualType ToType, 934 ASTContext &Context) { 935 QualType CanonFromPointee = Context.getCanonicalType(FromPtr->getPointeeType()); 936 QualType CanonToPointee = Context.getCanonicalType(ToPointee); 937 Qualifiers Quals = CanonFromPointee.getQualifiers(); 938 939 // Exact qualifier match -> return the pointer type we're converting to. 940 if (CanonToPointee.getLocalQualifiers() == Quals) { 941 // ToType is exactly what we need. Return it. 942 if (!ToType.isNull()) 943 return ToType; 944 945 // Build a pointer to ToPointee. It has the right qualifiers 946 // already. 947 return Context.getPointerType(ToPointee); 948 } 949 950 // Just build a canonical type that has the right qualifiers. 951 return Context.getPointerType( 952 Context.getQualifiedType(CanonToPointee.getLocalUnqualifiedType(), 953 Quals)); 954} 955 956/// BuildSimilarlyQualifiedObjCObjectPointerType - In a pointer conversion from 957/// the FromType, which is an objective-c pointer, to ToType, which may or may 958/// not have the right set of qualifiers. 959static QualType 960BuildSimilarlyQualifiedObjCObjectPointerType(QualType FromType, 961 QualType ToType, 962 ASTContext &Context) { 963 QualType CanonFromType = Context.getCanonicalType(FromType); 964 QualType CanonToType = Context.getCanonicalType(ToType); 965 Qualifiers Quals = CanonFromType.getQualifiers(); 966 967 // Exact qualifier match -> return the pointer type we're converting to. 968 if (CanonToType.getLocalQualifiers() == Quals) 969 return ToType; 970 971 // Just build a canonical type that has the right qualifiers. 972 return Context.getQualifiedType(CanonToType.getLocalUnqualifiedType(), Quals); 973} 974 975static bool isNullPointerConstantForConversion(Expr *Expr, 976 bool InOverloadResolution, 977 ASTContext &Context) { 978 // Handle value-dependent integral null pointer constants correctly. 979 // http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#903 980 if (Expr->isValueDependent() && !Expr->isTypeDependent() && 981 Expr->getType()->isIntegralType()) 982 return !InOverloadResolution; 983 984 return Expr->isNullPointerConstant(Context, 985 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull 986 : Expr::NPC_ValueDependentIsNull); 987} 988 989/// IsPointerConversion - Determines whether the conversion of the 990/// expression From, which has the (possibly adjusted) type FromType, 991/// can be converted to the type ToType via a pointer conversion (C++ 992/// 4.10). If so, returns true and places the converted type (that 993/// might differ from ToType in its cv-qualifiers at some level) into 994/// ConvertedType. 995/// 996/// This routine also supports conversions to and from block pointers 997/// and conversions with Objective-C's 'id', 'id<protocols...>', and 998/// pointers to interfaces. FIXME: Once we've determined the 999/// appropriate overloading rules for Objective-C, we may want to 1000/// split the Objective-C checks into a different routine; however, 1001/// GCC seems to consider all of these conversions to be pointer 1002/// conversions, so for now they live here. IncompatibleObjC will be 1003/// set if the conversion is an allowed Objective-C conversion that 1004/// should result in a warning. 1005bool Sema::IsPointerConversion(Expr *From, QualType FromType, QualType ToType, 1006 bool InOverloadResolution, 1007 QualType& ConvertedType, 1008 bool &IncompatibleObjC) { 1009 IncompatibleObjC = false; 1010 if (isObjCPointerConversion(FromType, ToType, ConvertedType, IncompatibleObjC)) 1011 return true; 1012 1013 // Conversion from a null pointer constant to any Objective-C pointer type. 1014 if (ToType->isObjCObjectPointerType() && 1015 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1016 ConvertedType = ToType; 1017 return true; 1018 } 1019 1020 // Blocks: Block pointers can be converted to void*. 1021 if (FromType->isBlockPointerType() && ToType->isPointerType() && 1022 ToType->getAs<PointerType>()->getPointeeType()->isVoidType()) { 1023 ConvertedType = ToType; 1024 return true; 1025 } 1026 // Blocks: A null pointer constant can be converted to a block 1027 // pointer type. 1028 if (ToType->isBlockPointerType() && 1029 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1030 ConvertedType = ToType; 1031 return true; 1032 } 1033 1034 // If the left-hand-side is nullptr_t, the right side can be a null 1035 // pointer constant. 1036 if (ToType->isNullPtrType() && 1037 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1038 ConvertedType = ToType; 1039 return true; 1040 } 1041 1042 const PointerType* ToTypePtr = ToType->getAs<PointerType>(); 1043 if (!ToTypePtr) 1044 return false; 1045 1046 // A null pointer constant can be converted to a pointer type (C++ 4.10p1). 1047 if (isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1048 ConvertedType = ToType; 1049 return true; 1050 } 1051 1052 // Beyond this point, both types need to be pointers 1053 // , including objective-c pointers. 1054 QualType ToPointeeType = ToTypePtr->getPointeeType(); 1055 if (FromType->isObjCObjectPointerType() && ToPointeeType->isVoidType()) { 1056 ConvertedType = BuildSimilarlyQualifiedObjCObjectPointerType(FromType, 1057 ToType, Context); 1058 return true; 1059 1060 } 1061 const PointerType *FromTypePtr = FromType->getAs<PointerType>(); 1062 if (!FromTypePtr) 1063 return false; 1064 1065 QualType FromPointeeType = FromTypePtr->getPointeeType(); 1066 1067 // An rvalue of type "pointer to cv T," where T is an object type, 1068 // can be converted to an rvalue of type "pointer to cv void" (C++ 1069 // 4.10p2). 1070 if (FromPointeeType->isObjectType() && ToPointeeType->isVoidType()) { 1071 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1072 ToPointeeType, 1073 ToType, Context); 1074 return true; 1075 } 1076 1077 // When we're overloading in C, we allow a special kind of pointer 1078 // conversion for compatible-but-not-identical pointee types. 1079 if (!getLangOptions().CPlusPlus && 1080 Context.typesAreCompatible(FromPointeeType, ToPointeeType)) { 1081 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1082 ToPointeeType, 1083 ToType, Context); 1084 return true; 1085 } 1086 1087 // C++ [conv.ptr]p3: 1088 // 1089 // An rvalue of type "pointer to cv D," where D is a class type, 1090 // can be converted to an rvalue of type "pointer to cv B," where 1091 // B is a base class (clause 10) of D. If B is an inaccessible 1092 // (clause 11) or ambiguous (10.2) base class of D, a program that 1093 // necessitates this conversion is ill-formed. The result of the 1094 // conversion is a pointer to the base class sub-object of the 1095 // derived class object. The null pointer value is converted to 1096 // the null pointer value of the destination type. 1097 // 1098 // Note that we do not check for ambiguity or inaccessibility 1099 // here. That is handled by CheckPointerConversion. 1100 if (getLangOptions().CPlusPlus && 1101 FromPointeeType->isRecordType() && ToPointeeType->isRecordType() && 1102 !Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType) && 1103 !RequireCompleteType(From->getLocStart(), FromPointeeType, PDiag()) && 1104 IsDerivedFrom(FromPointeeType, ToPointeeType)) { 1105 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1106 ToPointeeType, 1107 ToType, Context); 1108 return true; 1109 } 1110 1111 return false; 1112} 1113 1114/// isObjCPointerConversion - Determines whether this is an 1115/// Objective-C pointer conversion. Subroutine of IsPointerConversion, 1116/// with the same arguments and return values. 1117bool Sema::isObjCPointerConversion(QualType FromType, QualType ToType, 1118 QualType& ConvertedType, 1119 bool &IncompatibleObjC) { 1120 if (!getLangOptions().ObjC1) 1121 return false; 1122 1123 // First, we handle all conversions on ObjC object pointer types. 1124 const ObjCObjectPointerType* ToObjCPtr = ToType->getAs<ObjCObjectPointerType>(); 1125 const ObjCObjectPointerType *FromObjCPtr = 1126 FromType->getAs<ObjCObjectPointerType>(); 1127 1128 if (ToObjCPtr && FromObjCPtr) { 1129 // Objective C++: We're able to convert between "id" or "Class" and a 1130 // pointer to any interface (in both directions). 1131 if (ToObjCPtr->isObjCBuiltinType() && FromObjCPtr->isObjCBuiltinType()) { 1132 ConvertedType = ToType; 1133 return true; 1134 } 1135 // Conversions with Objective-C's id<...>. 1136 if ((FromObjCPtr->isObjCQualifiedIdType() || 1137 ToObjCPtr->isObjCQualifiedIdType()) && 1138 Context.ObjCQualifiedIdTypesAreCompatible(ToType, FromType, 1139 /*compare=*/false)) { 1140 ConvertedType = ToType; 1141 return true; 1142 } 1143 // Objective C++: We're able to convert from a pointer to an 1144 // interface to a pointer to a different interface. 1145 if (Context.canAssignObjCInterfaces(ToObjCPtr, FromObjCPtr)) { 1146 const ObjCInterfaceType* LHS = ToObjCPtr->getInterfaceType(); 1147 const ObjCInterfaceType* RHS = FromObjCPtr->getInterfaceType(); 1148 if (getLangOptions().CPlusPlus && LHS && RHS && 1149 !ToObjCPtr->getPointeeType().isAtLeastAsQualifiedAs( 1150 FromObjCPtr->getPointeeType())) 1151 return false; 1152 ConvertedType = ToType; 1153 return true; 1154 } 1155 1156 if (Context.canAssignObjCInterfaces(FromObjCPtr, ToObjCPtr)) { 1157 // Okay: this is some kind of implicit downcast of Objective-C 1158 // interfaces, which is permitted. However, we're going to 1159 // complain about it. 1160 IncompatibleObjC = true; 1161 ConvertedType = FromType; 1162 return true; 1163 } 1164 } 1165 // Beyond this point, both types need to be C pointers or block pointers. 1166 QualType ToPointeeType; 1167 if (const PointerType *ToCPtr = ToType->getAs<PointerType>()) 1168 ToPointeeType = ToCPtr->getPointeeType(); 1169 else if (const BlockPointerType *ToBlockPtr = 1170 ToType->getAs<BlockPointerType>()) { 1171 // Objective C++: We're able to convert from a pointer to any object 1172 // to a block pointer type. 1173 if (FromObjCPtr && FromObjCPtr->isObjCBuiltinType()) { 1174 ConvertedType = ToType; 1175 return true; 1176 } 1177 ToPointeeType = ToBlockPtr->getPointeeType(); 1178 } 1179 else if (FromType->getAs<BlockPointerType>() && 1180 ToObjCPtr && ToObjCPtr->isObjCBuiltinType()) { 1181 // Objective C++: We're able to convert from a block pointer type to a 1182 // pointer to any object. 1183 ConvertedType = ToType; 1184 return true; 1185 } 1186 else 1187 return false; 1188 1189 QualType FromPointeeType; 1190 if (const PointerType *FromCPtr = FromType->getAs<PointerType>()) 1191 FromPointeeType = FromCPtr->getPointeeType(); 1192 else if (const BlockPointerType *FromBlockPtr = FromType->getAs<BlockPointerType>()) 1193 FromPointeeType = FromBlockPtr->getPointeeType(); 1194 else 1195 return false; 1196 1197 // If we have pointers to pointers, recursively check whether this 1198 // is an Objective-C conversion. 1199 if (FromPointeeType->isPointerType() && ToPointeeType->isPointerType() && 1200 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, 1201 IncompatibleObjC)) { 1202 // We always complain about this conversion. 1203 IncompatibleObjC = true; 1204 ConvertedType = ToType; 1205 return true; 1206 } 1207 // Allow conversion of pointee being objective-c pointer to another one; 1208 // as in I* to id. 1209 if (FromPointeeType->getAs<ObjCObjectPointerType>() && 1210 ToPointeeType->getAs<ObjCObjectPointerType>() && 1211 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, 1212 IncompatibleObjC)) { 1213 ConvertedType = ToType; 1214 return true; 1215 } 1216 1217 // If we have pointers to functions or blocks, check whether the only 1218 // differences in the argument and result types are in Objective-C 1219 // pointer conversions. If so, we permit the conversion (but 1220 // complain about it). 1221 const FunctionProtoType *FromFunctionType 1222 = FromPointeeType->getAs<FunctionProtoType>(); 1223 const FunctionProtoType *ToFunctionType 1224 = ToPointeeType->getAs<FunctionProtoType>(); 1225 if (FromFunctionType && ToFunctionType) { 1226 // If the function types are exactly the same, this isn't an 1227 // Objective-C pointer conversion. 1228 if (Context.getCanonicalType(FromPointeeType) 1229 == Context.getCanonicalType(ToPointeeType)) 1230 return false; 1231 1232 // Perform the quick checks that will tell us whether these 1233 // function types are obviously different. 1234 if (FromFunctionType->getNumArgs() != ToFunctionType->getNumArgs() || 1235 FromFunctionType->isVariadic() != ToFunctionType->isVariadic() || 1236 FromFunctionType->getTypeQuals() != ToFunctionType->getTypeQuals()) 1237 return false; 1238 1239 bool HasObjCConversion = false; 1240 if (Context.getCanonicalType(FromFunctionType->getResultType()) 1241 == Context.getCanonicalType(ToFunctionType->getResultType())) { 1242 // Okay, the types match exactly. Nothing to do. 1243 } else if (isObjCPointerConversion(FromFunctionType->getResultType(), 1244 ToFunctionType->getResultType(), 1245 ConvertedType, IncompatibleObjC)) { 1246 // Okay, we have an Objective-C pointer conversion. 1247 HasObjCConversion = true; 1248 } else { 1249 // Function types are too different. Abort. 1250 return false; 1251 } 1252 1253 // Check argument types. 1254 for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumArgs(); 1255 ArgIdx != NumArgs; ++ArgIdx) { 1256 QualType FromArgType = FromFunctionType->getArgType(ArgIdx); 1257 QualType ToArgType = ToFunctionType->getArgType(ArgIdx); 1258 if (Context.getCanonicalType(FromArgType) 1259 == Context.getCanonicalType(ToArgType)) { 1260 // Okay, the types match exactly. Nothing to do. 1261 } else if (isObjCPointerConversion(FromArgType, ToArgType, 1262 ConvertedType, IncompatibleObjC)) { 1263 // Okay, we have an Objective-C pointer conversion. 1264 HasObjCConversion = true; 1265 } else { 1266 // Argument types are too different. Abort. 1267 return false; 1268 } 1269 } 1270 1271 if (HasObjCConversion) { 1272 // We had an Objective-C conversion. Allow this pointer 1273 // conversion, but complain about it. 1274 ConvertedType = ToType; 1275 IncompatibleObjC = true; 1276 return true; 1277 } 1278 } 1279 1280 return false; 1281} 1282 1283/// CheckPointerConversion - Check the pointer conversion from the 1284/// expression From to the type ToType. This routine checks for 1285/// ambiguous or inaccessible derived-to-base pointer 1286/// conversions for which IsPointerConversion has already returned 1287/// true. It returns true and produces a diagnostic if there was an 1288/// error, or returns false otherwise. 1289bool Sema::CheckPointerConversion(Expr *From, QualType ToType, 1290 CastExpr::CastKind &Kind, 1291 bool IgnoreBaseAccess) { 1292 QualType FromType = From->getType(); 1293 1294 if (const PointerType *FromPtrType = FromType->getAs<PointerType>()) 1295 if (const PointerType *ToPtrType = ToType->getAs<PointerType>()) { 1296 QualType FromPointeeType = FromPtrType->getPointeeType(), 1297 ToPointeeType = ToPtrType->getPointeeType(); 1298 1299 if (FromPointeeType->isRecordType() && ToPointeeType->isRecordType() && 1300 !Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType)) { 1301 // We must have a derived-to-base conversion. Check an 1302 // ambiguous or inaccessible conversion. 1303 if (CheckDerivedToBaseConversion(FromPointeeType, ToPointeeType, 1304 From->getExprLoc(), 1305 From->getSourceRange(), 1306 IgnoreBaseAccess)) 1307 return true; 1308 1309 // The conversion was successful. 1310 Kind = CastExpr::CK_DerivedToBase; 1311 } 1312 } 1313 if (const ObjCObjectPointerType *FromPtrType = 1314 FromType->getAs<ObjCObjectPointerType>()) 1315 if (const ObjCObjectPointerType *ToPtrType = 1316 ToType->getAs<ObjCObjectPointerType>()) { 1317 // Objective-C++ conversions are always okay. 1318 // FIXME: We should have a different class of conversions for the 1319 // Objective-C++ implicit conversions. 1320 if (FromPtrType->isObjCBuiltinType() || ToPtrType->isObjCBuiltinType()) 1321 return false; 1322 1323 } 1324 return false; 1325} 1326 1327/// IsMemberPointerConversion - Determines whether the conversion of the 1328/// expression From, which has the (possibly adjusted) type FromType, can be 1329/// converted to the type ToType via a member pointer conversion (C++ 4.11). 1330/// If so, returns true and places the converted type (that might differ from 1331/// ToType in its cv-qualifiers at some level) into ConvertedType. 1332bool Sema::IsMemberPointerConversion(Expr *From, QualType FromType, 1333 QualType ToType, 1334 bool InOverloadResolution, 1335 QualType &ConvertedType) { 1336 const MemberPointerType *ToTypePtr = ToType->getAs<MemberPointerType>(); 1337 if (!ToTypePtr) 1338 return false; 1339 1340 // A null pointer constant can be converted to a member pointer (C++ 4.11p1) 1341 if (From->isNullPointerConstant(Context, 1342 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull 1343 : Expr::NPC_ValueDependentIsNull)) { 1344 ConvertedType = ToType; 1345 return true; 1346 } 1347 1348 // Otherwise, both types have to be member pointers. 1349 const MemberPointerType *FromTypePtr = FromType->getAs<MemberPointerType>(); 1350 if (!FromTypePtr) 1351 return false; 1352 1353 // A pointer to member of B can be converted to a pointer to member of D, 1354 // where D is derived from B (C++ 4.11p2). 1355 QualType FromClass(FromTypePtr->getClass(), 0); 1356 QualType ToClass(ToTypePtr->getClass(), 0); 1357 // FIXME: What happens when these are dependent? Is this function even called? 1358 1359 if (IsDerivedFrom(ToClass, FromClass)) { 1360 ConvertedType = Context.getMemberPointerType(FromTypePtr->getPointeeType(), 1361 ToClass.getTypePtr()); 1362 return true; 1363 } 1364 1365 return false; 1366} 1367 1368/// CheckMemberPointerConversion - Check the member pointer conversion from the 1369/// expression From to the type ToType. This routine checks for ambiguous or 1370/// virtual or inaccessible base-to-derived member pointer conversions 1371/// for which IsMemberPointerConversion has already returned true. It returns 1372/// true and produces a diagnostic if there was an error, or returns false 1373/// otherwise. 1374bool Sema::CheckMemberPointerConversion(Expr *From, QualType ToType, 1375 CastExpr::CastKind &Kind, 1376 bool IgnoreBaseAccess) { 1377 QualType FromType = From->getType(); 1378 const MemberPointerType *FromPtrType = FromType->getAs<MemberPointerType>(); 1379 if (!FromPtrType) { 1380 // This must be a null pointer to member pointer conversion 1381 assert(From->isNullPointerConstant(Context, 1382 Expr::NPC_ValueDependentIsNull) && 1383 "Expr must be null pointer constant!"); 1384 Kind = CastExpr::CK_NullToMemberPointer; 1385 return false; 1386 } 1387 1388 const MemberPointerType *ToPtrType = ToType->getAs<MemberPointerType>(); 1389 assert(ToPtrType && "No member pointer cast has a target type " 1390 "that is not a member pointer."); 1391 1392 QualType FromClass = QualType(FromPtrType->getClass(), 0); 1393 QualType ToClass = QualType(ToPtrType->getClass(), 0); 1394 1395 // FIXME: What about dependent types? 1396 assert(FromClass->isRecordType() && "Pointer into non-class."); 1397 assert(ToClass->isRecordType() && "Pointer into non-class."); 1398 1399 CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/ true, 1400 /*DetectVirtual=*/true); 1401 bool DerivationOkay = IsDerivedFrom(ToClass, FromClass, Paths); 1402 assert(DerivationOkay && 1403 "Should not have been called if derivation isn't OK."); 1404 (void)DerivationOkay; 1405 1406 if (Paths.isAmbiguous(Context.getCanonicalType(FromClass). 1407 getUnqualifiedType())) { 1408 std::string PathDisplayStr = getAmbiguousPathsDisplayString(Paths); 1409 Diag(From->getExprLoc(), diag::err_ambiguous_memptr_conv) 1410 << 0 << FromClass << ToClass << PathDisplayStr << From->getSourceRange(); 1411 return true; 1412 } 1413 1414 if (const RecordType *VBase = Paths.getDetectedVirtual()) { 1415 Diag(From->getExprLoc(), diag::err_memptr_conv_via_virtual) 1416 << FromClass << ToClass << QualType(VBase, 0) 1417 << From->getSourceRange(); 1418 return true; 1419 } 1420 1421 if (!IgnoreBaseAccess) 1422 CheckBaseClassAccess(From->getExprLoc(), FromClass, ToClass, 1423 Paths.front(), 1424 diag::err_downcast_from_inaccessible_base); 1425 1426 // Must be a base to derived member conversion. 1427 Kind = CastExpr::CK_BaseToDerivedMemberPointer; 1428 return false; 1429} 1430 1431/// IsQualificationConversion - Determines whether the conversion from 1432/// an rvalue of type FromType to ToType is a qualification conversion 1433/// (C++ 4.4). 1434bool 1435Sema::IsQualificationConversion(QualType FromType, QualType ToType) { 1436 FromType = Context.getCanonicalType(FromType); 1437 ToType = Context.getCanonicalType(ToType); 1438 1439 // If FromType and ToType are the same type, this is not a 1440 // qualification conversion. 1441 if (FromType.getUnqualifiedType() == ToType.getUnqualifiedType()) 1442 return false; 1443 1444 // (C++ 4.4p4): 1445 // A conversion can add cv-qualifiers at levels other than the first 1446 // in multi-level pointers, subject to the following rules: [...] 1447 bool PreviousToQualsIncludeConst = true; 1448 bool UnwrappedAnyPointer = false; 1449 while (UnwrapSimilarPointerTypes(FromType, ToType)) { 1450 // Within each iteration of the loop, we check the qualifiers to 1451 // determine if this still looks like a qualification 1452 // conversion. Then, if all is well, we unwrap one more level of 1453 // pointers or pointers-to-members and do it all again 1454 // until there are no more pointers or pointers-to-members left to 1455 // unwrap. 1456 UnwrappedAnyPointer = true; 1457 1458 // -- for every j > 0, if const is in cv 1,j then const is in cv 1459 // 2,j, and similarly for volatile. 1460 if (!ToType.isAtLeastAsQualifiedAs(FromType)) 1461 return false; 1462 1463 // -- if the cv 1,j and cv 2,j are different, then const is in 1464 // every cv for 0 < k < j. 1465 if (FromType.getCVRQualifiers() != ToType.getCVRQualifiers() 1466 && !PreviousToQualsIncludeConst) 1467 return false; 1468 1469 // Keep track of whether all prior cv-qualifiers in the "to" type 1470 // include const. 1471 PreviousToQualsIncludeConst 1472 = PreviousToQualsIncludeConst && ToType.isConstQualified(); 1473 } 1474 1475 // We are left with FromType and ToType being the pointee types 1476 // after unwrapping the original FromType and ToType the same number 1477 // of types. If we unwrapped any pointers, and if FromType and 1478 // ToType have the same unqualified type (since we checked 1479 // qualifiers above), then this is a qualification conversion. 1480 return UnwrappedAnyPointer && Context.hasSameUnqualifiedType(FromType,ToType); 1481} 1482 1483/// Determines whether there is a user-defined conversion sequence 1484/// (C++ [over.ics.user]) that converts expression From to the type 1485/// ToType. If such a conversion exists, User will contain the 1486/// user-defined conversion sequence that performs such a conversion 1487/// and this routine will return true. Otherwise, this routine returns 1488/// false and User is unspecified. 1489/// 1490/// \param AllowConversionFunctions true if the conversion should 1491/// consider conversion functions at all. If false, only constructors 1492/// will be considered. 1493/// 1494/// \param AllowExplicit true if the conversion should consider C++0x 1495/// "explicit" conversion functions as well as non-explicit conversion 1496/// functions (C++0x [class.conv.fct]p2). 1497/// 1498/// \param UserCast true if looking for user defined conversion for a static 1499/// cast. 1500OverloadingResult Sema::IsUserDefinedConversion(Expr *From, QualType ToType, 1501 UserDefinedConversionSequence& User, 1502 OverloadCandidateSet& CandidateSet, 1503 bool AllowConversionFunctions, 1504 bool AllowExplicit, 1505 bool UserCast) { 1506 if (const RecordType *ToRecordType = ToType->getAs<RecordType>()) { 1507 if (RequireCompleteType(From->getLocStart(), ToType, PDiag())) { 1508 // We're not going to find any constructors. 1509 } else if (CXXRecordDecl *ToRecordDecl 1510 = dyn_cast<CXXRecordDecl>(ToRecordType->getDecl())) { 1511 // C++ [over.match.ctor]p1: 1512 // When objects of class type are direct-initialized (8.5), or 1513 // copy-initialized from an expression of the same or a 1514 // derived class type (8.5), overload resolution selects the 1515 // constructor. [...] For copy-initialization, the candidate 1516 // functions are all the converting constructors (12.3.1) of 1517 // that class. The argument list is the expression-list within 1518 // the parentheses of the initializer. 1519 bool SuppressUserConversions = !UserCast; 1520 if (Context.hasSameUnqualifiedType(ToType, From->getType()) || 1521 IsDerivedFrom(From->getType(), ToType)) { 1522 SuppressUserConversions = false; 1523 AllowConversionFunctions = false; 1524 } 1525 1526 DeclarationName ConstructorName 1527 = Context.DeclarationNames.getCXXConstructorName( 1528 Context.getCanonicalType(ToType).getUnqualifiedType()); 1529 DeclContext::lookup_iterator Con, ConEnd; 1530 for (llvm::tie(Con, ConEnd) 1531 = ToRecordDecl->lookup(ConstructorName); 1532 Con != ConEnd; ++Con) { 1533 NamedDecl *D = *Con; 1534 DeclAccessPair FoundDecl = DeclAccessPair::make(D, D->getAccess()); 1535 1536 // Find the constructor (which may be a template). 1537 CXXConstructorDecl *Constructor = 0; 1538 FunctionTemplateDecl *ConstructorTmpl 1539 = dyn_cast<FunctionTemplateDecl>(D); 1540 if (ConstructorTmpl) 1541 Constructor 1542 = cast<CXXConstructorDecl>(ConstructorTmpl->getTemplatedDecl()); 1543 else 1544 Constructor = cast<CXXConstructorDecl>(D); 1545 1546 if (!Constructor->isInvalidDecl() && 1547 Constructor->isConvertingConstructor(AllowExplicit)) { 1548 if (ConstructorTmpl) 1549 AddTemplateOverloadCandidate(ConstructorTmpl, FoundDecl, 1550 /*ExplicitArgs*/ 0, 1551 &From, 1, CandidateSet, 1552 SuppressUserConversions); 1553 else 1554 // Allow one user-defined conversion when user specifies a 1555 // From->ToType conversion via an static cast (c-style, etc). 1556 AddOverloadCandidate(Constructor, FoundDecl, 1557 &From, 1, CandidateSet, 1558 SuppressUserConversions, false); 1559 } 1560 } 1561 } 1562 } 1563 1564 if (!AllowConversionFunctions) { 1565 // Don't allow any conversion functions to enter the overload set. 1566 } else if (RequireCompleteType(From->getLocStart(), From->getType(), 1567 PDiag(0) 1568 << From->getSourceRange())) { 1569 // No conversion functions from incomplete types. 1570 } else if (const RecordType *FromRecordType 1571 = From->getType()->getAs<RecordType>()) { 1572 if (CXXRecordDecl *FromRecordDecl 1573 = dyn_cast<CXXRecordDecl>(FromRecordType->getDecl())) { 1574 // Add all of the conversion functions as candidates. 1575 const UnresolvedSetImpl *Conversions 1576 = FromRecordDecl->getVisibleConversionFunctions(); 1577 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 1578 E = Conversions->end(); I != E; ++I) { 1579 DeclAccessPair FoundDecl = I.getPair(); 1580 NamedDecl *D = FoundDecl.getDecl(); 1581 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext()); 1582 if (isa<UsingShadowDecl>(D)) 1583 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 1584 1585 CXXConversionDecl *Conv; 1586 FunctionTemplateDecl *ConvTemplate; 1587 if ((ConvTemplate = dyn_cast<FunctionTemplateDecl>(D))) 1588 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 1589 else 1590 Conv = cast<CXXConversionDecl>(D); 1591 1592 if (AllowExplicit || !Conv->isExplicit()) { 1593 if (ConvTemplate) 1594 AddTemplateConversionCandidate(ConvTemplate, FoundDecl, 1595 ActingContext, From, ToType, 1596 CandidateSet); 1597 else 1598 AddConversionCandidate(Conv, FoundDecl, ActingContext, 1599 From, ToType, CandidateSet); 1600 } 1601 } 1602 } 1603 } 1604 1605 OverloadCandidateSet::iterator Best; 1606 switch (BestViableFunction(CandidateSet, From->getLocStart(), Best)) { 1607 case OR_Success: 1608 // Record the standard conversion we used and the conversion function. 1609 if (CXXConstructorDecl *Constructor 1610 = dyn_cast<CXXConstructorDecl>(Best->Function)) { 1611 // C++ [over.ics.user]p1: 1612 // If the user-defined conversion is specified by a 1613 // constructor (12.3.1), the initial standard conversion 1614 // sequence converts the source type to the type required by 1615 // the argument of the constructor. 1616 // 1617 QualType ThisType = Constructor->getThisType(Context); 1618 if (Best->Conversions[0].isEllipsis()) 1619 User.EllipsisConversion = true; 1620 else { 1621 User.Before = Best->Conversions[0].Standard; 1622 User.EllipsisConversion = false; 1623 } 1624 User.ConversionFunction = Constructor; 1625 User.After.setAsIdentityConversion(); 1626 User.After.setFromType( 1627 ThisType->getAs<PointerType>()->getPointeeType()); 1628 User.After.setAllToTypes(ToType); 1629 return OR_Success; 1630 } else if (CXXConversionDecl *Conversion 1631 = dyn_cast<CXXConversionDecl>(Best->Function)) { 1632 // C++ [over.ics.user]p1: 1633 // 1634 // [...] If the user-defined conversion is specified by a 1635 // conversion function (12.3.2), the initial standard 1636 // conversion sequence converts the source type to the 1637 // implicit object parameter of the conversion function. 1638 User.Before = Best->Conversions[0].Standard; 1639 User.ConversionFunction = Conversion; 1640 User.EllipsisConversion = false; 1641 1642 // C++ [over.ics.user]p2: 1643 // The second standard conversion sequence converts the 1644 // result of the user-defined conversion to the target type 1645 // for the sequence. Since an implicit conversion sequence 1646 // is an initialization, the special rules for 1647 // initialization by user-defined conversion apply when 1648 // selecting the best user-defined conversion for a 1649 // user-defined conversion sequence (see 13.3.3 and 1650 // 13.3.3.1). 1651 User.After = Best->FinalConversion; 1652 return OR_Success; 1653 } else { 1654 assert(false && "Not a constructor or conversion function?"); 1655 return OR_No_Viable_Function; 1656 } 1657 1658 case OR_No_Viable_Function: 1659 return OR_No_Viable_Function; 1660 case OR_Deleted: 1661 // No conversion here! We're done. 1662 return OR_Deleted; 1663 1664 case OR_Ambiguous: 1665 return OR_Ambiguous; 1666 } 1667 1668 return OR_No_Viable_Function; 1669} 1670 1671bool 1672Sema::DiagnoseMultipleUserDefinedConversion(Expr *From, QualType ToType) { 1673 ImplicitConversionSequence ICS; 1674 OverloadCandidateSet CandidateSet(From->getExprLoc()); 1675 OverloadingResult OvResult = 1676 IsUserDefinedConversion(From, ToType, ICS.UserDefined, 1677 CandidateSet, true, false, false); 1678 if (OvResult == OR_Ambiguous) 1679 Diag(From->getSourceRange().getBegin(), 1680 diag::err_typecheck_ambiguous_condition) 1681 << From->getType() << ToType << From->getSourceRange(); 1682 else if (OvResult == OR_No_Viable_Function && !CandidateSet.empty()) 1683 Diag(From->getSourceRange().getBegin(), 1684 diag::err_typecheck_nonviable_condition) 1685 << From->getType() << ToType << From->getSourceRange(); 1686 else 1687 return false; 1688 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, &From, 1); 1689 return true; 1690} 1691 1692/// CompareImplicitConversionSequences - Compare two implicit 1693/// conversion sequences to determine whether one is better than the 1694/// other or if they are indistinguishable (C++ 13.3.3.2). 1695ImplicitConversionSequence::CompareKind 1696Sema::CompareImplicitConversionSequences(const ImplicitConversionSequence& ICS1, 1697 const ImplicitConversionSequence& ICS2) 1698{ 1699 // (C++ 13.3.3.2p2): When comparing the basic forms of implicit 1700 // conversion sequences (as defined in 13.3.3.1) 1701 // -- a standard conversion sequence (13.3.3.1.1) is a better 1702 // conversion sequence than a user-defined conversion sequence or 1703 // an ellipsis conversion sequence, and 1704 // -- a user-defined conversion sequence (13.3.3.1.2) is a better 1705 // conversion sequence than an ellipsis conversion sequence 1706 // (13.3.3.1.3). 1707 // 1708 // C++0x [over.best.ics]p10: 1709 // For the purpose of ranking implicit conversion sequences as 1710 // described in 13.3.3.2, the ambiguous conversion sequence is 1711 // treated as a user-defined sequence that is indistinguishable 1712 // from any other user-defined conversion sequence. 1713 if (ICS1.getKind() < ICS2.getKind()) { 1714 if (!(ICS1.isUserDefined() && ICS2.isAmbiguous())) 1715 return ImplicitConversionSequence::Better; 1716 } else if (ICS2.getKind() < ICS1.getKind()) { 1717 if (!(ICS2.isUserDefined() && ICS1.isAmbiguous())) 1718 return ImplicitConversionSequence::Worse; 1719 } 1720 1721 if (ICS1.isAmbiguous() || ICS2.isAmbiguous()) 1722 return ImplicitConversionSequence::Indistinguishable; 1723 1724 // Two implicit conversion sequences of the same form are 1725 // indistinguishable conversion sequences unless one of the 1726 // following rules apply: (C++ 13.3.3.2p3): 1727 if (ICS1.isStandard()) 1728 return CompareStandardConversionSequences(ICS1.Standard, ICS2.Standard); 1729 else if (ICS1.isUserDefined()) { 1730 // User-defined conversion sequence U1 is a better conversion 1731 // sequence than another user-defined conversion sequence U2 if 1732 // they contain the same user-defined conversion function or 1733 // constructor and if the second standard conversion sequence of 1734 // U1 is better than the second standard conversion sequence of 1735 // U2 (C++ 13.3.3.2p3). 1736 if (ICS1.UserDefined.ConversionFunction == 1737 ICS2.UserDefined.ConversionFunction) 1738 return CompareStandardConversionSequences(ICS1.UserDefined.After, 1739 ICS2.UserDefined.After); 1740 } 1741 1742 return ImplicitConversionSequence::Indistinguishable; 1743} 1744 1745// Per 13.3.3.2p3, compare the given standard conversion sequences to 1746// determine if one is a proper subset of the other. 1747static ImplicitConversionSequence::CompareKind 1748compareStandardConversionSubsets(ASTContext &Context, 1749 const StandardConversionSequence& SCS1, 1750 const StandardConversionSequence& SCS2) { 1751 ImplicitConversionSequence::CompareKind Result 1752 = ImplicitConversionSequence::Indistinguishable; 1753 1754 if (SCS1.Second != SCS2.Second) { 1755 if (SCS1.Second == ICK_Identity) 1756 Result = ImplicitConversionSequence::Better; 1757 else if (SCS2.Second == ICK_Identity) 1758 Result = ImplicitConversionSequence::Worse; 1759 else 1760 return ImplicitConversionSequence::Indistinguishable; 1761 } else if (!Context.hasSameType(SCS1.getToType(1), SCS2.getToType(1))) 1762 return ImplicitConversionSequence::Indistinguishable; 1763 1764 if (SCS1.Third == SCS2.Third) { 1765 return Context.hasSameType(SCS1.getToType(2), SCS2.getToType(2))? Result 1766 : ImplicitConversionSequence::Indistinguishable; 1767 } 1768 1769 if (SCS1.Third == ICK_Identity) 1770 return Result == ImplicitConversionSequence::Worse 1771 ? ImplicitConversionSequence::Indistinguishable 1772 : ImplicitConversionSequence::Better; 1773 1774 if (SCS2.Third == ICK_Identity) 1775 return Result == ImplicitConversionSequence::Better 1776 ? ImplicitConversionSequence::Indistinguishable 1777 : ImplicitConversionSequence::Worse; 1778 1779 return ImplicitConversionSequence::Indistinguishable; 1780} 1781 1782/// CompareStandardConversionSequences - Compare two standard 1783/// conversion sequences to determine whether one is better than the 1784/// other or if they are indistinguishable (C++ 13.3.3.2p3). 1785ImplicitConversionSequence::CompareKind 1786Sema::CompareStandardConversionSequences(const StandardConversionSequence& SCS1, 1787 const StandardConversionSequence& SCS2) 1788{ 1789 // Standard conversion sequence S1 is a better conversion sequence 1790 // than standard conversion sequence S2 if (C++ 13.3.3.2p3): 1791 1792 // -- S1 is a proper subsequence of S2 (comparing the conversion 1793 // sequences in the canonical form defined by 13.3.3.1.1, 1794 // excluding any Lvalue Transformation; the identity conversion 1795 // sequence is considered to be a subsequence of any 1796 // non-identity conversion sequence) or, if not that, 1797 if (ImplicitConversionSequence::CompareKind CK 1798 = compareStandardConversionSubsets(Context, SCS1, SCS2)) 1799 return CK; 1800 1801 // -- the rank of S1 is better than the rank of S2 (by the rules 1802 // defined below), or, if not that, 1803 ImplicitConversionRank Rank1 = SCS1.getRank(); 1804 ImplicitConversionRank Rank2 = SCS2.getRank(); 1805 if (Rank1 < Rank2) 1806 return ImplicitConversionSequence::Better; 1807 else if (Rank2 < Rank1) 1808 return ImplicitConversionSequence::Worse; 1809 1810 // (C++ 13.3.3.2p4): Two conversion sequences with the same rank 1811 // are indistinguishable unless one of the following rules 1812 // applies: 1813 1814 // A conversion that is not a conversion of a pointer, or 1815 // pointer to member, to bool is better than another conversion 1816 // that is such a conversion. 1817 if (SCS1.isPointerConversionToBool() != SCS2.isPointerConversionToBool()) 1818 return SCS2.isPointerConversionToBool() 1819 ? ImplicitConversionSequence::Better 1820 : ImplicitConversionSequence::Worse; 1821 1822 // C++ [over.ics.rank]p4b2: 1823 // 1824 // If class B is derived directly or indirectly from class A, 1825 // conversion of B* to A* is better than conversion of B* to 1826 // void*, and conversion of A* to void* is better than conversion 1827 // of B* to void*. 1828 bool SCS1ConvertsToVoid 1829 = SCS1.isPointerConversionToVoidPointer(Context); 1830 bool SCS2ConvertsToVoid 1831 = SCS2.isPointerConversionToVoidPointer(Context); 1832 if (SCS1ConvertsToVoid != SCS2ConvertsToVoid) { 1833 // Exactly one of the conversion sequences is a conversion to 1834 // a void pointer; it's the worse conversion. 1835 return SCS2ConvertsToVoid ? ImplicitConversionSequence::Better 1836 : ImplicitConversionSequence::Worse; 1837 } else if (!SCS1ConvertsToVoid && !SCS2ConvertsToVoid) { 1838 // Neither conversion sequence converts to a void pointer; compare 1839 // their derived-to-base conversions. 1840 if (ImplicitConversionSequence::CompareKind DerivedCK 1841 = CompareDerivedToBaseConversions(SCS1, SCS2)) 1842 return DerivedCK; 1843 } else if (SCS1ConvertsToVoid && SCS2ConvertsToVoid) { 1844 // Both conversion sequences are conversions to void 1845 // pointers. Compare the source types to determine if there's an 1846 // inheritance relationship in their sources. 1847 QualType FromType1 = SCS1.getFromType(); 1848 QualType FromType2 = SCS2.getFromType(); 1849 1850 // Adjust the types we're converting from via the array-to-pointer 1851 // conversion, if we need to. 1852 if (SCS1.First == ICK_Array_To_Pointer) 1853 FromType1 = Context.getArrayDecayedType(FromType1); 1854 if (SCS2.First == ICK_Array_To_Pointer) 1855 FromType2 = Context.getArrayDecayedType(FromType2); 1856 1857 QualType FromPointee1 1858 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1859 QualType FromPointee2 1860 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1861 1862 if (IsDerivedFrom(FromPointee2, FromPointee1)) 1863 return ImplicitConversionSequence::Better; 1864 else if (IsDerivedFrom(FromPointee1, FromPointee2)) 1865 return ImplicitConversionSequence::Worse; 1866 1867 // Objective-C++: If one interface is more specific than the 1868 // other, it is the better one. 1869 const ObjCInterfaceType* FromIface1 = FromPointee1->getAs<ObjCInterfaceType>(); 1870 const ObjCInterfaceType* FromIface2 = FromPointee2->getAs<ObjCInterfaceType>(); 1871 if (FromIface1 && FromIface1) { 1872 if (Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 1873 return ImplicitConversionSequence::Better; 1874 else if (Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 1875 return ImplicitConversionSequence::Worse; 1876 } 1877 } 1878 1879 // Compare based on qualification conversions (C++ 13.3.3.2p3, 1880 // bullet 3). 1881 if (ImplicitConversionSequence::CompareKind QualCK 1882 = CompareQualificationConversions(SCS1, SCS2)) 1883 return QualCK; 1884 1885 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding) { 1886 // C++0x [over.ics.rank]p3b4: 1887 // -- S1 and S2 are reference bindings (8.5.3) and neither refers to an 1888 // implicit object parameter of a non-static member function declared 1889 // without a ref-qualifier, and S1 binds an rvalue reference to an 1890 // rvalue and S2 binds an lvalue reference. 1891 // FIXME: We don't know if we're dealing with the implicit object parameter, 1892 // or if the member function in this case has a ref qualifier. 1893 // (Of course, we don't have ref qualifiers yet.) 1894 if (SCS1.RRefBinding != SCS2.RRefBinding) 1895 return SCS1.RRefBinding ? ImplicitConversionSequence::Better 1896 : ImplicitConversionSequence::Worse; 1897 1898 // C++ [over.ics.rank]p3b4: 1899 // -- S1 and S2 are reference bindings (8.5.3), and the types to 1900 // which the references refer are the same type except for 1901 // top-level cv-qualifiers, and the type to which the reference 1902 // initialized by S2 refers is more cv-qualified than the type 1903 // to which the reference initialized by S1 refers. 1904 QualType T1 = SCS1.getToType(2); 1905 QualType T2 = SCS2.getToType(2); 1906 T1 = Context.getCanonicalType(T1); 1907 T2 = Context.getCanonicalType(T2); 1908 Qualifiers T1Quals, T2Quals; 1909 QualType UnqualT1 = Context.getUnqualifiedArrayType(T1, T1Quals); 1910 QualType UnqualT2 = Context.getUnqualifiedArrayType(T2, T2Quals); 1911 if (UnqualT1 == UnqualT2) { 1912 // If the type is an array type, promote the element qualifiers to the type 1913 // for comparison. 1914 if (isa<ArrayType>(T1) && T1Quals) 1915 T1 = Context.getQualifiedType(UnqualT1, T1Quals); 1916 if (isa<ArrayType>(T2) && T2Quals) 1917 T2 = Context.getQualifiedType(UnqualT2, T2Quals); 1918 if (T2.isMoreQualifiedThan(T1)) 1919 return ImplicitConversionSequence::Better; 1920 else if (T1.isMoreQualifiedThan(T2)) 1921 return ImplicitConversionSequence::Worse; 1922 } 1923 } 1924 1925 return ImplicitConversionSequence::Indistinguishable; 1926} 1927 1928/// CompareQualificationConversions - Compares two standard conversion 1929/// sequences to determine whether they can be ranked based on their 1930/// qualification conversions (C++ 13.3.3.2p3 bullet 3). 1931ImplicitConversionSequence::CompareKind 1932Sema::CompareQualificationConversions(const StandardConversionSequence& SCS1, 1933 const StandardConversionSequence& SCS2) { 1934 // C++ 13.3.3.2p3: 1935 // -- S1 and S2 differ only in their qualification conversion and 1936 // yield similar types T1 and T2 (C++ 4.4), respectively, and the 1937 // cv-qualification signature of type T1 is a proper subset of 1938 // the cv-qualification signature of type T2, and S1 is not the 1939 // deprecated string literal array-to-pointer conversion (4.2). 1940 if (SCS1.First != SCS2.First || SCS1.Second != SCS2.Second || 1941 SCS1.Third != SCS2.Third || SCS1.Third != ICK_Qualification) 1942 return ImplicitConversionSequence::Indistinguishable; 1943 1944 // FIXME: the example in the standard doesn't use a qualification 1945 // conversion (!) 1946 QualType T1 = SCS1.getToType(2); 1947 QualType T2 = SCS2.getToType(2); 1948 T1 = Context.getCanonicalType(T1); 1949 T2 = Context.getCanonicalType(T2); 1950 Qualifiers T1Quals, T2Quals; 1951 QualType UnqualT1 = Context.getUnqualifiedArrayType(T1, T1Quals); 1952 QualType UnqualT2 = Context.getUnqualifiedArrayType(T2, T2Quals); 1953 1954 // If the types are the same, we won't learn anything by unwrapped 1955 // them. 1956 if (UnqualT1 == UnqualT2) 1957 return ImplicitConversionSequence::Indistinguishable; 1958 1959 // If the type is an array type, promote the element qualifiers to the type 1960 // for comparison. 1961 if (isa<ArrayType>(T1) && T1Quals) 1962 T1 = Context.getQualifiedType(UnqualT1, T1Quals); 1963 if (isa<ArrayType>(T2) && T2Quals) 1964 T2 = Context.getQualifiedType(UnqualT2, T2Quals); 1965 1966 ImplicitConversionSequence::CompareKind Result 1967 = ImplicitConversionSequence::Indistinguishable; 1968 while (UnwrapSimilarPointerTypes(T1, T2)) { 1969 // Within each iteration of the loop, we check the qualifiers to 1970 // determine if this still looks like a qualification 1971 // conversion. Then, if all is well, we unwrap one more level of 1972 // pointers or pointers-to-members and do it all again 1973 // until there are no more pointers or pointers-to-members left 1974 // to unwrap. This essentially mimics what 1975 // IsQualificationConversion does, but here we're checking for a 1976 // strict subset of qualifiers. 1977 if (T1.getCVRQualifiers() == T2.getCVRQualifiers()) 1978 // The qualifiers are the same, so this doesn't tell us anything 1979 // about how the sequences rank. 1980 ; 1981 else if (T2.isMoreQualifiedThan(T1)) { 1982 // T1 has fewer qualifiers, so it could be the better sequence. 1983 if (Result == ImplicitConversionSequence::Worse) 1984 // Neither has qualifiers that are a subset of the other's 1985 // qualifiers. 1986 return ImplicitConversionSequence::Indistinguishable; 1987 1988 Result = ImplicitConversionSequence::Better; 1989 } else if (T1.isMoreQualifiedThan(T2)) { 1990 // T2 has fewer qualifiers, so it could be the better sequence. 1991 if (Result == ImplicitConversionSequence::Better) 1992 // Neither has qualifiers that are a subset of the other's 1993 // qualifiers. 1994 return ImplicitConversionSequence::Indistinguishable; 1995 1996 Result = ImplicitConversionSequence::Worse; 1997 } else { 1998 // Qualifiers are disjoint. 1999 return ImplicitConversionSequence::Indistinguishable; 2000 } 2001 2002 // If the types after this point are equivalent, we're done. 2003 if (Context.hasSameUnqualifiedType(T1, T2)) 2004 break; 2005 } 2006 2007 // Check that the winning standard conversion sequence isn't using 2008 // the deprecated string literal array to pointer conversion. 2009 switch (Result) { 2010 case ImplicitConversionSequence::Better: 2011 if (SCS1.DeprecatedStringLiteralToCharPtr) 2012 Result = ImplicitConversionSequence::Indistinguishable; 2013 break; 2014 2015 case ImplicitConversionSequence::Indistinguishable: 2016 break; 2017 2018 case ImplicitConversionSequence::Worse: 2019 if (SCS2.DeprecatedStringLiteralToCharPtr) 2020 Result = ImplicitConversionSequence::Indistinguishable; 2021 break; 2022 } 2023 2024 return Result; 2025} 2026 2027/// CompareDerivedToBaseConversions - Compares two standard conversion 2028/// sequences to determine whether they can be ranked based on their 2029/// various kinds of derived-to-base conversions (C++ 2030/// [over.ics.rank]p4b3). As part of these checks, we also look at 2031/// conversions between Objective-C interface types. 2032ImplicitConversionSequence::CompareKind 2033Sema::CompareDerivedToBaseConversions(const StandardConversionSequence& SCS1, 2034 const StandardConversionSequence& SCS2) { 2035 QualType FromType1 = SCS1.getFromType(); 2036 QualType ToType1 = SCS1.getToType(1); 2037 QualType FromType2 = SCS2.getFromType(); 2038 QualType ToType2 = SCS2.getToType(1); 2039 2040 // Adjust the types we're converting from via the array-to-pointer 2041 // conversion, if we need to. 2042 if (SCS1.First == ICK_Array_To_Pointer) 2043 FromType1 = Context.getArrayDecayedType(FromType1); 2044 if (SCS2.First == ICK_Array_To_Pointer) 2045 FromType2 = Context.getArrayDecayedType(FromType2); 2046 2047 // Canonicalize all of the types. 2048 FromType1 = Context.getCanonicalType(FromType1); 2049 ToType1 = Context.getCanonicalType(ToType1); 2050 FromType2 = Context.getCanonicalType(FromType2); 2051 ToType2 = Context.getCanonicalType(ToType2); 2052 2053 // C++ [over.ics.rank]p4b3: 2054 // 2055 // If class B is derived directly or indirectly from class A and 2056 // class C is derived directly or indirectly from B, 2057 // 2058 // For Objective-C, we let A, B, and C also be Objective-C 2059 // interfaces. 2060 2061 // Compare based on pointer conversions. 2062 if (SCS1.Second == ICK_Pointer_Conversion && 2063 SCS2.Second == ICK_Pointer_Conversion && 2064 /*FIXME: Remove if Objective-C id conversions get their own rank*/ 2065 FromType1->isPointerType() && FromType2->isPointerType() && 2066 ToType1->isPointerType() && ToType2->isPointerType()) { 2067 QualType FromPointee1 2068 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2069 QualType ToPointee1 2070 = ToType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2071 QualType FromPointee2 2072 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2073 QualType ToPointee2 2074 = ToType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2075 2076 const ObjCInterfaceType* FromIface1 = FromPointee1->getAs<ObjCInterfaceType>(); 2077 const ObjCInterfaceType* FromIface2 = FromPointee2->getAs<ObjCInterfaceType>(); 2078 const ObjCInterfaceType* ToIface1 = ToPointee1->getAs<ObjCInterfaceType>(); 2079 const ObjCInterfaceType* ToIface2 = ToPointee2->getAs<ObjCInterfaceType>(); 2080 2081 // -- conversion of C* to B* is better than conversion of C* to A*, 2082 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 2083 if (IsDerivedFrom(ToPointee1, ToPointee2)) 2084 return ImplicitConversionSequence::Better; 2085 else if (IsDerivedFrom(ToPointee2, ToPointee1)) 2086 return ImplicitConversionSequence::Worse; 2087 2088 if (ToIface1 && ToIface2) { 2089 if (Context.canAssignObjCInterfaces(ToIface2, ToIface1)) 2090 return ImplicitConversionSequence::Better; 2091 else if (Context.canAssignObjCInterfaces(ToIface1, ToIface2)) 2092 return ImplicitConversionSequence::Worse; 2093 } 2094 } 2095 2096 // -- conversion of B* to A* is better than conversion of C* to A*, 2097 if (FromPointee1 != FromPointee2 && ToPointee1 == ToPointee2) { 2098 if (IsDerivedFrom(FromPointee2, FromPointee1)) 2099 return ImplicitConversionSequence::Better; 2100 else if (IsDerivedFrom(FromPointee1, FromPointee2)) 2101 return ImplicitConversionSequence::Worse; 2102 2103 if (FromIface1 && FromIface2) { 2104 if (Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 2105 return ImplicitConversionSequence::Better; 2106 else if (Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 2107 return ImplicitConversionSequence::Worse; 2108 } 2109 } 2110 } 2111 2112 // Ranking of member-pointer types. 2113 if (SCS1.Second == ICK_Pointer_Member && SCS2.Second == ICK_Pointer_Member && 2114 FromType1->isMemberPointerType() && FromType2->isMemberPointerType() && 2115 ToType1->isMemberPointerType() && ToType2->isMemberPointerType()) { 2116 const MemberPointerType * FromMemPointer1 = 2117 FromType1->getAs<MemberPointerType>(); 2118 const MemberPointerType * ToMemPointer1 = 2119 ToType1->getAs<MemberPointerType>(); 2120 const MemberPointerType * FromMemPointer2 = 2121 FromType2->getAs<MemberPointerType>(); 2122 const MemberPointerType * ToMemPointer2 = 2123 ToType2->getAs<MemberPointerType>(); 2124 const Type *FromPointeeType1 = FromMemPointer1->getClass(); 2125 const Type *ToPointeeType1 = ToMemPointer1->getClass(); 2126 const Type *FromPointeeType2 = FromMemPointer2->getClass(); 2127 const Type *ToPointeeType2 = ToMemPointer2->getClass(); 2128 QualType FromPointee1 = QualType(FromPointeeType1, 0).getUnqualifiedType(); 2129 QualType ToPointee1 = QualType(ToPointeeType1, 0).getUnqualifiedType(); 2130 QualType FromPointee2 = QualType(FromPointeeType2, 0).getUnqualifiedType(); 2131 QualType ToPointee2 = QualType(ToPointeeType2, 0).getUnqualifiedType(); 2132 // conversion of A::* to B::* is better than conversion of A::* to C::*, 2133 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 2134 if (IsDerivedFrom(ToPointee1, ToPointee2)) 2135 return ImplicitConversionSequence::Worse; 2136 else if (IsDerivedFrom(ToPointee2, ToPointee1)) 2137 return ImplicitConversionSequence::Better; 2138 } 2139 // conversion of B::* to C::* is better than conversion of A::* to C::* 2140 if (ToPointee1 == ToPointee2 && FromPointee1 != FromPointee2) { 2141 if (IsDerivedFrom(FromPointee1, FromPointee2)) 2142 return ImplicitConversionSequence::Better; 2143 else if (IsDerivedFrom(FromPointee2, FromPointee1)) 2144 return ImplicitConversionSequence::Worse; 2145 } 2146 } 2147 2148 if ((SCS1.ReferenceBinding || SCS1.CopyConstructor) && 2149 (SCS2.ReferenceBinding || SCS2.CopyConstructor) && 2150 SCS1.Second == ICK_Derived_To_Base) { 2151 // -- conversion of C to B is better than conversion of C to A, 2152 // -- binding of an expression of type C to a reference of type 2153 // B& is better than binding an expression of type C to a 2154 // reference of type A&, 2155 if (Context.hasSameUnqualifiedType(FromType1, FromType2) && 2156 !Context.hasSameUnqualifiedType(ToType1, ToType2)) { 2157 if (IsDerivedFrom(ToType1, ToType2)) 2158 return ImplicitConversionSequence::Better; 2159 else if (IsDerivedFrom(ToType2, ToType1)) 2160 return ImplicitConversionSequence::Worse; 2161 } 2162 2163 // -- conversion of B to A is better than conversion of C to A. 2164 // -- binding of an expression of type B to a reference of type 2165 // A& is better than binding an expression of type C to a 2166 // reference of type A&, 2167 if (!Context.hasSameUnqualifiedType(FromType1, FromType2) && 2168 Context.hasSameUnqualifiedType(ToType1, ToType2)) { 2169 if (IsDerivedFrom(FromType2, FromType1)) 2170 return ImplicitConversionSequence::Better; 2171 else if (IsDerivedFrom(FromType1, FromType2)) 2172 return ImplicitConversionSequence::Worse; 2173 } 2174 } 2175 2176 return ImplicitConversionSequence::Indistinguishable; 2177} 2178 2179/// CompareReferenceRelationship - Compare the two types T1 and T2 to 2180/// determine whether they are reference-related, 2181/// reference-compatible, reference-compatible with added 2182/// qualification, or incompatible, for use in C++ initialization by 2183/// reference (C++ [dcl.ref.init]p4). Neither type can be a reference 2184/// type, and the first type (T1) is the pointee type of the reference 2185/// type being initialized. 2186Sema::ReferenceCompareResult 2187Sema::CompareReferenceRelationship(SourceLocation Loc, 2188 QualType OrigT1, QualType OrigT2, 2189 bool& DerivedToBase) { 2190 assert(!OrigT1->isReferenceType() && 2191 "T1 must be the pointee type of the reference type"); 2192 assert(!OrigT2->isReferenceType() && "T2 cannot be a reference type"); 2193 2194 QualType T1 = Context.getCanonicalType(OrigT1); 2195 QualType T2 = Context.getCanonicalType(OrigT2); 2196 Qualifiers T1Quals, T2Quals; 2197 QualType UnqualT1 = Context.getUnqualifiedArrayType(T1, T1Quals); 2198 QualType UnqualT2 = Context.getUnqualifiedArrayType(T2, T2Quals); 2199 2200 // C++ [dcl.init.ref]p4: 2201 // Given types "cv1 T1" and "cv2 T2," "cv1 T1" is 2202 // reference-related to "cv2 T2" if T1 is the same type as T2, or 2203 // T1 is a base class of T2. 2204 if (UnqualT1 == UnqualT2) 2205 DerivedToBase = false; 2206 else if (!RequireCompleteType(Loc, OrigT1, PDiag()) && 2207 !RequireCompleteType(Loc, OrigT2, PDiag()) && 2208 IsDerivedFrom(UnqualT2, UnqualT1)) 2209 DerivedToBase = true; 2210 else 2211 return Ref_Incompatible; 2212 2213 // At this point, we know that T1 and T2 are reference-related (at 2214 // least). 2215 2216 // If the type is an array type, promote the element qualifiers to the type 2217 // for comparison. 2218 if (isa<ArrayType>(T1) && T1Quals) 2219 T1 = Context.getQualifiedType(UnqualT1, T1Quals); 2220 if (isa<ArrayType>(T2) && T2Quals) 2221 T2 = Context.getQualifiedType(UnqualT2, T2Quals); 2222 2223 // C++ [dcl.init.ref]p4: 2224 // "cv1 T1" is reference-compatible with "cv2 T2" if T1 is 2225 // reference-related to T2 and cv1 is the same cv-qualification 2226 // as, or greater cv-qualification than, cv2. For purposes of 2227 // overload resolution, cases for which cv1 is greater 2228 // cv-qualification than cv2 are identified as 2229 // reference-compatible with added qualification (see 13.3.3.2). 2230 if (T1Quals.getCVRQualifiers() == T2Quals.getCVRQualifiers()) 2231 return Ref_Compatible; 2232 else if (T1.isMoreQualifiedThan(T2)) 2233 return Ref_Compatible_With_Added_Qualification; 2234 else 2235 return Ref_Related; 2236} 2237 2238/// \brief Compute an implicit conversion sequence for reference 2239/// initialization. 2240static ImplicitConversionSequence 2241TryReferenceInit(Sema &S, Expr *&Init, QualType DeclType, 2242 SourceLocation DeclLoc, 2243 bool SuppressUserConversions, 2244 bool AllowExplicit, bool ForceRValue) { 2245 assert(DeclType->isReferenceType() && "Reference init needs a reference"); 2246 2247 // Most paths end in a failed conversion. 2248 ImplicitConversionSequence ICS; 2249 ICS.setBad(BadConversionSequence::no_conversion, Init, DeclType); 2250 2251 QualType T1 = DeclType->getAs<ReferenceType>()->getPointeeType(); 2252 QualType T2 = Init->getType(); 2253 2254 // If the initializer is the address of an overloaded function, try 2255 // to resolve the overloaded function. If all goes well, T2 is the 2256 // type of the resulting function. 2257 if (S.Context.getCanonicalType(T2) == S.Context.OverloadTy) { 2258 DeclAccessPair Found; 2259 if (FunctionDecl *Fn = S.ResolveAddressOfOverloadedFunction(Init, DeclType, 2260 false, Found)) 2261 T2 = Fn->getType(); 2262 } 2263 2264 // Compute some basic properties of the types and the initializer. 2265 bool isRValRef = DeclType->isRValueReferenceType(); 2266 bool DerivedToBase = false; 2267 Expr::isLvalueResult InitLvalue = ForceRValue ? Expr::LV_InvalidExpression : 2268 Init->isLvalue(S.Context); 2269 Sema::ReferenceCompareResult RefRelationship 2270 = S.CompareReferenceRelationship(DeclLoc, T1, T2, DerivedToBase); 2271 2272 // C++ [dcl.init.ref]p5: 2273 // A reference to type "cv1 T1" is initialized by an expression 2274 // of type "cv2 T2" as follows: 2275 2276 // -- If the initializer expression 2277 2278 // C++ [over.ics.ref]p3: 2279 // Except for an implicit object parameter, for which see 13.3.1, 2280 // a standard conversion sequence cannot be formed if it requires 2281 // binding an lvalue reference to non-const to an rvalue or 2282 // binding an rvalue reference to an lvalue. 2283 if (isRValRef && InitLvalue == Expr::LV_Valid) 2284 return ICS; 2285 2286 // -- is an lvalue (but is not a bit-field), and "cv1 T1" is 2287 // reference-compatible with "cv2 T2," or 2288 // 2289 // Per C++ [over.ics.ref]p4, we don't check the bit-field property here. 2290 if (InitLvalue == Expr::LV_Valid && 2291 RefRelationship >= Sema::Ref_Compatible_With_Added_Qualification) { 2292 // C++ [over.ics.ref]p1: 2293 // When a parameter of reference type binds directly (8.5.3) 2294 // to an argument expression, the implicit conversion sequence 2295 // is the identity conversion, unless the argument expression 2296 // has a type that is a derived class of the parameter type, 2297 // in which case the implicit conversion sequence is a 2298 // derived-to-base Conversion (13.3.3.1). 2299 ICS.setStandard(); 2300 ICS.Standard.First = ICK_Identity; 2301 ICS.Standard.Second = DerivedToBase? ICK_Derived_To_Base : ICK_Identity; 2302 ICS.Standard.Third = ICK_Identity; 2303 ICS.Standard.FromTypePtr = T2.getAsOpaquePtr(); 2304 ICS.Standard.setToType(0, T2); 2305 ICS.Standard.setToType(1, T1); 2306 ICS.Standard.setToType(2, T1); 2307 ICS.Standard.ReferenceBinding = true; 2308 ICS.Standard.DirectBinding = true; 2309 ICS.Standard.RRefBinding = false; 2310 ICS.Standard.CopyConstructor = 0; 2311 2312 // Nothing more to do: the inaccessibility/ambiguity check for 2313 // derived-to-base conversions is suppressed when we're 2314 // computing the implicit conversion sequence (C++ 2315 // [over.best.ics]p2). 2316 return ICS; 2317 } 2318 2319 // -- has a class type (i.e., T2 is a class type), where T1 is 2320 // not reference-related to T2, and can be implicitly 2321 // converted to an lvalue of type "cv3 T3," where "cv1 T1" 2322 // is reference-compatible with "cv3 T3" 92) (this 2323 // conversion is selected by enumerating the applicable 2324 // conversion functions (13.3.1.6) and choosing the best 2325 // one through overload resolution (13.3)), 2326 if (!isRValRef && !SuppressUserConversions && T2->isRecordType() && 2327 !S.RequireCompleteType(DeclLoc, T2, 0) && 2328 RefRelationship == Sema::Ref_Incompatible) { 2329 CXXRecordDecl *T2RecordDecl 2330 = dyn_cast<CXXRecordDecl>(T2->getAs<RecordType>()->getDecl()); 2331 2332 OverloadCandidateSet CandidateSet(DeclLoc); 2333 const UnresolvedSetImpl *Conversions 2334 = T2RecordDecl->getVisibleConversionFunctions(); 2335 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 2336 E = Conversions->end(); I != E; ++I) { 2337 NamedDecl *D = *I; 2338 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(D->getDeclContext()); 2339 if (isa<UsingShadowDecl>(D)) 2340 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 2341 2342 FunctionTemplateDecl *ConvTemplate 2343 = dyn_cast<FunctionTemplateDecl>(D); 2344 CXXConversionDecl *Conv; 2345 if (ConvTemplate) 2346 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 2347 else 2348 Conv = cast<CXXConversionDecl>(D); 2349 2350 // If the conversion function doesn't return a reference type, 2351 // it can't be considered for this conversion. 2352 if (Conv->getConversionType()->isLValueReferenceType() && 2353 (AllowExplicit || !Conv->isExplicit())) { 2354 if (ConvTemplate) 2355 S.AddTemplateConversionCandidate(ConvTemplate, I.getPair(), ActingDC, 2356 Init, DeclType, CandidateSet); 2357 else 2358 S.AddConversionCandidate(Conv, I.getPair(), ActingDC, Init, 2359 DeclType, CandidateSet); 2360 } 2361 } 2362 2363 OverloadCandidateSet::iterator Best; 2364 switch (S.BestViableFunction(CandidateSet, DeclLoc, Best)) { 2365 case OR_Success: 2366 // C++ [over.ics.ref]p1: 2367 // 2368 // [...] If the parameter binds directly to the result of 2369 // applying a conversion function to the argument 2370 // expression, the implicit conversion sequence is a 2371 // user-defined conversion sequence (13.3.3.1.2), with the 2372 // second standard conversion sequence either an identity 2373 // conversion or, if the conversion function returns an 2374 // entity of a type that is a derived class of the parameter 2375 // type, a derived-to-base Conversion. 2376 if (!Best->FinalConversion.DirectBinding) 2377 break; 2378 2379 ICS.setUserDefined(); 2380 ICS.UserDefined.Before = Best->Conversions[0].Standard; 2381 ICS.UserDefined.After = Best->FinalConversion; 2382 ICS.UserDefined.ConversionFunction = Best->Function; 2383 ICS.UserDefined.EllipsisConversion = false; 2384 assert(ICS.UserDefined.After.ReferenceBinding && 2385 ICS.UserDefined.After.DirectBinding && 2386 "Expected a direct reference binding!"); 2387 return ICS; 2388 2389 case OR_Ambiguous: 2390 ICS.setAmbiguous(); 2391 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 2392 Cand != CandidateSet.end(); ++Cand) 2393 if (Cand->Viable) 2394 ICS.Ambiguous.addConversion(Cand->Function); 2395 return ICS; 2396 2397 case OR_No_Viable_Function: 2398 case OR_Deleted: 2399 // There was no suitable conversion, or we found a deleted 2400 // conversion; continue with other checks. 2401 break; 2402 } 2403 } 2404 2405 // -- Otherwise, the reference shall be to a non-volatile const 2406 // type (i.e., cv1 shall be const), or the reference shall be an 2407 // rvalue reference and the initializer expression shall be an rvalue. 2408 if (!isRValRef && T1.getCVRQualifiers() != Qualifiers::Const) 2409 return ICS; 2410 2411 // -- If the initializer expression is an rvalue, with T2 a 2412 // class type, and "cv1 T1" is reference-compatible with 2413 // "cv2 T2," the reference is bound in one of the 2414 // following ways (the choice is implementation-defined): 2415 // 2416 // -- The reference is bound to the object represented by 2417 // the rvalue (see 3.10) or to a sub-object within that 2418 // object. 2419 // 2420 // -- A temporary of type "cv1 T2" [sic] is created, and 2421 // a constructor is called to copy the entire rvalue 2422 // object into the temporary. The reference is bound to 2423 // the temporary or to a sub-object within the 2424 // temporary. 2425 // 2426 // The constructor that would be used to make the copy 2427 // shall be callable whether or not the copy is actually 2428 // done. 2429 // 2430 // Note that C++0x [dcl.init.ref]p5 takes away this implementation 2431 // freedom, so we will always take the first option and never build 2432 // a temporary in this case. 2433 if (InitLvalue != Expr::LV_Valid && T2->isRecordType() && 2434 RefRelationship >= Sema::Ref_Compatible_With_Added_Qualification) { 2435 ICS.setStandard(); 2436 ICS.Standard.First = ICK_Identity; 2437 ICS.Standard.Second = DerivedToBase? ICK_Derived_To_Base : ICK_Identity; 2438 ICS.Standard.Third = ICK_Identity; 2439 ICS.Standard.FromTypePtr = T2.getAsOpaquePtr(); 2440 ICS.Standard.setToType(0, T2); 2441 ICS.Standard.setToType(1, T1); 2442 ICS.Standard.setToType(2, T1); 2443 ICS.Standard.ReferenceBinding = true; 2444 ICS.Standard.DirectBinding = false; 2445 ICS.Standard.RRefBinding = isRValRef; 2446 ICS.Standard.CopyConstructor = 0; 2447 return ICS; 2448 } 2449 2450 // -- Otherwise, a temporary of type "cv1 T1" is created and 2451 // initialized from the initializer expression using the 2452 // rules for a non-reference copy initialization (8.5). The 2453 // reference is then bound to the temporary. If T1 is 2454 // reference-related to T2, cv1 must be the same 2455 // cv-qualification as, or greater cv-qualification than, 2456 // cv2; otherwise, the program is ill-formed. 2457 if (RefRelationship == Sema::Ref_Related) { 2458 // If cv1 == cv2 or cv1 is a greater cv-qualified than cv2, then 2459 // we would be reference-compatible or reference-compatible with 2460 // added qualification. But that wasn't the case, so the reference 2461 // initialization fails. 2462 return ICS; 2463 } 2464 2465 // If at least one of the types is a class type, the types are not 2466 // related, and we aren't allowed any user conversions, the 2467 // reference binding fails. This case is important for breaking 2468 // recursion, since TryImplicitConversion below will attempt to 2469 // create a temporary through the use of a copy constructor. 2470 if (SuppressUserConversions && RefRelationship == Sema::Ref_Incompatible && 2471 (T1->isRecordType() || T2->isRecordType())) 2472 return ICS; 2473 2474 // C++ [over.ics.ref]p2: 2475 // 2476 // When a parameter of reference type is not bound directly to 2477 // an argument expression, the conversion sequence is the one 2478 // required to convert the argument expression to the 2479 // underlying type of the reference according to 2480 // 13.3.3.1. Conceptually, this conversion sequence corresponds 2481 // to copy-initializing a temporary of the underlying type with 2482 // the argument expression. Any difference in top-level 2483 // cv-qualification is subsumed by the initialization itself 2484 // and does not constitute a conversion. 2485 ICS = S.TryImplicitConversion(Init, T1, SuppressUserConversions, 2486 /*AllowExplicit=*/false, 2487 /*ForceRValue=*/false, 2488 /*InOverloadResolution=*/false); 2489 2490 // Of course, that's still a reference binding. 2491 if (ICS.isStandard()) { 2492 ICS.Standard.ReferenceBinding = true; 2493 ICS.Standard.RRefBinding = isRValRef; 2494 } else if (ICS.isUserDefined()) { 2495 ICS.UserDefined.After.ReferenceBinding = true; 2496 ICS.UserDefined.After.RRefBinding = isRValRef; 2497 } 2498 return ICS; 2499} 2500 2501/// TryCopyInitialization - Try to copy-initialize a value of type 2502/// ToType from the expression From. Return the implicit conversion 2503/// sequence required to pass this argument, which may be a bad 2504/// conversion sequence (meaning that the argument cannot be passed to 2505/// a parameter of this type). If @p SuppressUserConversions, then we 2506/// do not permit any user-defined conversion sequences. If @p ForceRValue, 2507/// then we treat @p From as an rvalue, even if it is an lvalue. 2508ImplicitConversionSequence 2509Sema::TryCopyInitialization(Expr *From, QualType ToType, 2510 bool SuppressUserConversions, bool ForceRValue, 2511 bool InOverloadResolution) { 2512 if (ToType->isReferenceType()) 2513 return TryReferenceInit(*this, From, ToType, 2514 /*FIXME:*/From->getLocStart(), 2515 SuppressUserConversions, 2516 /*AllowExplicit=*/false, 2517 ForceRValue); 2518 2519 return TryImplicitConversion(From, ToType, 2520 SuppressUserConversions, 2521 /*AllowExplicit=*/false, 2522 ForceRValue, 2523 InOverloadResolution); 2524} 2525 2526/// TryObjectArgumentInitialization - Try to initialize the object 2527/// parameter of the given member function (@c Method) from the 2528/// expression @p From. 2529ImplicitConversionSequence 2530Sema::TryObjectArgumentInitialization(QualType OrigFromType, 2531 CXXMethodDecl *Method, 2532 CXXRecordDecl *ActingContext) { 2533 QualType ClassType = Context.getTypeDeclType(ActingContext); 2534 // [class.dtor]p2: A destructor can be invoked for a const, volatile or 2535 // const volatile object. 2536 unsigned Quals = isa<CXXDestructorDecl>(Method) ? 2537 Qualifiers::Const | Qualifiers::Volatile : Method->getTypeQualifiers(); 2538 QualType ImplicitParamType = Context.getCVRQualifiedType(ClassType, Quals); 2539 2540 // Set up the conversion sequence as a "bad" conversion, to allow us 2541 // to exit early. 2542 ImplicitConversionSequence ICS; 2543 2544 // We need to have an object of class type. 2545 QualType FromType = OrigFromType; 2546 if (const PointerType *PT = FromType->getAs<PointerType>()) 2547 FromType = PT->getPointeeType(); 2548 2549 assert(FromType->isRecordType()); 2550 2551 // The implicit object parameter is has the type "reference to cv X", 2552 // where X is the class of which the function is a member 2553 // (C++ [over.match.funcs]p4). However, when finding an implicit 2554 // conversion sequence for the argument, we are not allowed to 2555 // create temporaries or perform user-defined conversions 2556 // (C++ [over.match.funcs]p5). We perform a simplified version of 2557 // reference binding here, that allows class rvalues to bind to 2558 // non-constant references. 2559 2560 // First check the qualifiers. We don't care about lvalue-vs-rvalue 2561 // with the implicit object parameter (C++ [over.match.funcs]p5). 2562 QualType FromTypeCanon = Context.getCanonicalType(FromType); 2563 if (ImplicitParamType.getCVRQualifiers() 2564 != FromTypeCanon.getLocalCVRQualifiers() && 2565 !ImplicitParamType.isAtLeastAsQualifiedAs(FromTypeCanon)) { 2566 ICS.setBad(BadConversionSequence::bad_qualifiers, 2567 OrigFromType, ImplicitParamType); 2568 return ICS; 2569 } 2570 2571 // Check that we have either the same type or a derived type. It 2572 // affects the conversion rank. 2573 QualType ClassTypeCanon = Context.getCanonicalType(ClassType); 2574 ImplicitConversionKind SecondKind; 2575 if (ClassTypeCanon == FromTypeCanon.getLocalUnqualifiedType()) { 2576 SecondKind = ICK_Identity; 2577 } else if (IsDerivedFrom(FromType, ClassType)) 2578 SecondKind = ICK_Derived_To_Base; 2579 else { 2580 ICS.setBad(BadConversionSequence::unrelated_class, 2581 FromType, ImplicitParamType); 2582 return ICS; 2583 } 2584 2585 // Success. Mark this as a reference binding. 2586 ICS.setStandard(); 2587 ICS.Standard.setAsIdentityConversion(); 2588 ICS.Standard.Second = SecondKind; 2589 ICS.Standard.setFromType(FromType); 2590 ICS.Standard.setAllToTypes(ImplicitParamType); 2591 ICS.Standard.ReferenceBinding = true; 2592 ICS.Standard.DirectBinding = true; 2593 ICS.Standard.RRefBinding = false; 2594 return ICS; 2595} 2596 2597/// PerformObjectArgumentInitialization - Perform initialization of 2598/// the implicit object parameter for the given Method with the given 2599/// expression. 2600bool 2601Sema::PerformObjectArgumentInitialization(Expr *&From, 2602 NestedNameSpecifier *Qualifier, 2603 NamedDecl *FoundDecl, 2604 CXXMethodDecl *Method) { 2605 QualType FromRecordType, DestType; 2606 QualType ImplicitParamRecordType = 2607 Method->getThisType(Context)->getAs<PointerType>()->getPointeeType(); 2608 2609 if (const PointerType *PT = From->getType()->getAs<PointerType>()) { 2610 FromRecordType = PT->getPointeeType(); 2611 DestType = Method->getThisType(Context); 2612 } else { 2613 FromRecordType = From->getType(); 2614 DestType = ImplicitParamRecordType; 2615 } 2616 2617 // Note that we always use the true parent context when performing 2618 // the actual argument initialization. 2619 ImplicitConversionSequence ICS 2620 = TryObjectArgumentInitialization(From->getType(), Method, 2621 Method->getParent()); 2622 if (ICS.isBad()) 2623 return Diag(From->getSourceRange().getBegin(), 2624 diag::err_implicit_object_parameter_init) 2625 << ImplicitParamRecordType << FromRecordType << From->getSourceRange(); 2626 2627 if (ICS.Standard.Second == ICK_Derived_To_Base) 2628 return PerformObjectMemberConversion(From, Qualifier, FoundDecl, Method); 2629 2630 if (!Context.hasSameType(From->getType(), DestType)) 2631 ImpCastExprToType(From, DestType, CastExpr::CK_NoOp, 2632 /*isLvalue=*/!From->getType()->getAs<PointerType>()); 2633 return false; 2634} 2635 2636/// TryContextuallyConvertToBool - Attempt to contextually convert the 2637/// expression From to bool (C++0x [conv]p3). 2638ImplicitConversionSequence Sema::TryContextuallyConvertToBool(Expr *From) { 2639 return TryImplicitConversion(From, Context.BoolTy, 2640 // FIXME: Are these flags correct? 2641 /*SuppressUserConversions=*/false, 2642 /*AllowExplicit=*/true, 2643 /*ForceRValue=*/false, 2644 /*InOverloadResolution=*/false); 2645} 2646 2647/// PerformContextuallyConvertToBool - Perform a contextual conversion 2648/// of the expression From to bool (C++0x [conv]p3). 2649bool Sema::PerformContextuallyConvertToBool(Expr *&From) { 2650 ImplicitConversionSequence ICS = TryContextuallyConvertToBool(From); 2651 if (!ICS.isBad()) 2652 return PerformImplicitConversion(From, Context.BoolTy, ICS, AA_Converting); 2653 2654 if (!DiagnoseMultipleUserDefinedConversion(From, Context.BoolTy)) 2655 return Diag(From->getSourceRange().getBegin(), 2656 diag::err_typecheck_bool_condition) 2657 << From->getType() << From->getSourceRange(); 2658 return true; 2659} 2660 2661/// AddOverloadCandidate - Adds the given function to the set of 2662/// candidate functions, using the given function call arguments. If 2663/// @p SuppressUserConversions, then don't allow user-defined 2664/// conversions via constructors or conversion operators. 2665/// If @p ForceRValue, treat all arguments as rvalues. This is a slightly 2666/// hacky way to implement the overloading rules for elidable copy 2667/// initialization in C++0x (C++0x 12.8p15). 2668/// 2669/// \para PartialOverloading true if we are performing "partial" overloading 2670/// based on an incomplete set of function arguments. This feature is used by 2671/// code completion. 2672void 2673Sema::AddOverloadCandidate(FunctionDecl *Function, 2674 DeclAccessPair FoundDecl, 2675 Expr **Args, unsigned NumArgs, 2676 OverloadCandidateSet& CandidateSet, 2677 bool SuppressUserConversions, 2678 bool ForceRValue, 2679 bool PartialOverloading) { 2680 const FunctionProtoType* Proto 2681 = dyn_cast<FunctionProtoType>(Function->getType()->getAs<FunctionType>()); 2682 assert(Proto && "Functions without a prototype cannot be overloaded"); 2683 assert(!Function->getDescribedFunctionTemplate() && 2684 "Use AddTemplateOverloadCandidate for function templates"); 2685 2686 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Function)) { 2687 if (!isa<CXXConstructorDecl>(Method)) { 2688 // If we get here, it's because we're calling a member function 2689 // that is named without a member access expression (e.g., 2690 // "this->f") that was either written explicitly or created 2691 // implicitly. This can happen with a qualified call to a member 2692 // function, e.g., X::f(). We use an empty type for the implied 2693 // object argument (C++ [over.call.func]p3), and the acting context 2694 // is irrelevant. 2695 AddMethodCandidate(Method, FoundDecl, Method->getParent(), 2696 QualType(), Args, NumArgs, CandidateSet, 2697 SuppressUserConversions); 2698 return; 2699 } 2700 // We treat a constructor like a non-member function, since its object 2701 // argument doesn't participate in overload resolution. 2702 } 2703 2704 if (!CandidateSet.isNewCandidate(Function)) 2705 return; 2706 2707 // Overload resolution is always an unevaluated context. 2708 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 2709 2710 if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(Function)){ 2711 // C++ [class.copy]p3: 2712 // A member function template is never instantiated to perform the copy 2713 // of a class object to an object of its class type. 2714 QualType ClassType = Context.getTypeDeclType(Constructor->getParent()); 2715 if (NumArgs == 1 && 2716 Constructor->isCopyConstructorLikeSpecialization() && 2717 (Context.hasSameUnqualifiedType(ClassType, Args[0]->getType()) || 2718 IsDerivedFrom(Args[0]->getType(), ClassType))) 2719 return; 2720 } 2721 2722 // Add this candidate 2723 CandidateSet.push_back(OverloadCandidate()); 2724 OverloadCandidate& Candidate = CandidateSet.back(); 2725 Candidate.FoundDecl = FoundDecl; 2726 Candidate.Function = Function; 2727 Candidate.Viable = true; 2728 Candidate.IsSurrogate = false; 2729 Candidate.IgnoreObjectArgument = false; 2730 2731 unsigned NumArgsInProto = Proto->getNumArgs(); 2732 2733 // (C++ 13.3.2p2): A candidate function having fewer than m 2734 // parameters is viable only if it has an ellipsis in its parameter 2735 // list (8.3.5). 2736 if ((NumArgs + (PartialOverloading && NumArgs)) > NumArgsInProto && 2737 !Proto->isVariadic()) { 2738 Candidate.Viable = false; 2739 Candidate.FailureKind = ovl_fail_too_many_arguments; 2740 return; 2741 } 2742 2743 // (C++ 13.3.2p2): A candidate function having more than m parameters 2744 // is viable only if the (m+1)st parameter has a default argument 2745 // (8.3.6). For the purposes of overload resolution, the 2746 // parameter list is truncated on the right, so that there are 2747 // exactly m parameters. 2748 unsigned MinRequiredArgs = Function->getMinRequiredArguments(); 2749 if (NumArgs < MinRequiredArgs && !PartialOverloading) { 2750 // Not enough arguments. 2751 Candidate.Viable = false; 2752 Candidate.FailureKind = ovl_fail_too_few_arguments; 2753 return; 2754 } 2755 2756 // Determine the implicit conversion sequences for each of the 2757 // arguments. 2758 Candidate.Conversions.resize(NumArgs); 2759 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2760 if (ArgIdx < NumArgsInProto) { 2761 // (C++ 13.3.2p3): for F to be a viable function, there shall 2762 // exist for each argument an implicit conversion sequence 2763 // (13.3.3.1) that converts that argument to the corresponding 2764 // parameter of F. 2765 QualType ParamType = Proto->getArgType(ArgIdx); 2766 Candidate.Conversions[ArgIdx] 2767 = TryCopyInitialization(Args[ArgIdx], ParamType, 2768 SuppressUserConversions, ForceRValue, 2769 /*InOverloadResolution=*/true); 2770 if (Candidate.Conversions[ArgIdx].isBad()) { 2771 Candidate.Viable = false; 2772 Candidate.FailureKind = ovl_fail_bad_conversion; 2773 break; 2774 } 2775 } else { 2776 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2777 // argument for which there is no corresponding parameter is 2778 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2779 Candidate.Conversions[ArgIdx].setEllipsis(); 2780 } 2781 } 2782} 2783 2784/// \brief Add all of the function declarations in the given function set to 2785/// the overload canddiate set. 2786void Sema::AddFunctionCandidates(const UnresolvedSetImpl &Fns, 2787 Expr **Args, unsigned NumArgs, 2788 OverloadCandidateSet& CandidateSet, 2789 bool SuppressUserConversions) { 2790 for (UnresolvedSetIterator F = Fns.begin(), E = Fns.end(); F != E; ++F) { 2791 NamedDecl *D = F.getDecl()->getUnderlyingDecl(); 2792 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { 2793 if (isa<CXXMethodDecl>(FD) && !cast<CXXMethodDecl>(FD)->isStatic()) 2794 AddMethodCandidate(cast<CXXMethodDecl>(FD), F.getPair(), 2795 cast<CXXMethodDecl>(FD)->getParent(), 2796 Args[0]->getType(), Args + 1, NumArgs - 1, 2797 CandidateSet, SuppressUserConversions); 2798 else 2799 AddOverloadCandidate(FD, F.getPair(), Args, NumArgs, CandidateSet, 2800 SuppressUserConversions); 2801 } else { 2802 FunctionTemplateDecl *FunTmpl = cast<FunctionTemplateDecl>(D); 2803 if (isa<CXXMethodDecl>(FunTmpl->getTemplatedDecl()) && 2804 !cast<CXXMethodDecl>(FunTmpl->getTemplatedDecl())->isStatic()) 2805 AddMethodTemplateCandidate(FunTmpl, F.getPair(), 2806 cast<CXXRecordDecl>(FunTmpl->getDeclContext()), 2807 /*FIXME: explicit args */ 0, 2808 Args[0]->getType(), Args + 1, NumArgs - 1, 2809 CandidateSet, 2810 SuppressUserConversions); 2811 else 2812 AddTemplateOverloadCandidate(FunTmpl, F.getPair(), 2813 /*FIXME: explicit args */ 0, 2814 Args, NumArgs, CandidateSet, 2815 SuppressUserConversions); 2816 } 2817 } 2818} 2819 2820/// AddMethodCandidate - Adds a named decl (which is some kind of 2821/// method) as a method candidate to the given overload set. 2822void Sema::AddMethodCandidate(DeclAccessPair FoundDecl, 2823 QualType ObjectType, 2824 Expr **Args, unsigned NumArgs, 2825 OverloadCandidateSet& CandidateSet, 2826 bool SuppressUserConversions) { 2827 NamedDecl *Decl = FoundDecl.getDecl(); 2828 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(Decl->getDeclContext()); 2829 2830 if (isa<UsingShadowDecl>(Decl)) 2831 Decl = cast<UsingShadowDecl>(Decl)->getTargetDecl(); 2832 2833 if (FunctionTemplateDecl *TD = dyn_cast<FunctionTemplateDecl>(Decl)) { 2834 assert(isa<CXXMethodDecl>(TD->getTemplatedDecl()) && 2835 "Expected a member function template"); 2836 AddMethodTemplateCandidate(TD, FoundDecl, ActingContext, 2837 /*ExplicitArgs*/ 0, 2838 ObjectType, Args, NumArgs, 2839 CandidateSet, 2840 SuppressUserConversions); 2841 } else { 2842 AddMethodCandidate(cast<CXXMethodDecl>(Decl), FoundDecl, ActingContext, 2843 ObjectType, Args, NumArgs, 2844 CandidateSet, SuppressUserConversions); 2845 } 2846} 2847 2848/// AddMethodCandidate - Adds the given C++ member function to the set 2849/// of candidate functions, using the given function call arguments 2850/// and the object argument (@c Object). For example, in a call 2851/// @c o.f(a1,a2), @c Object will contain @c o and @c Args will contain 2852/// both @c a1 and @c a2. If @p SuppressUserConversions, then don't 2853/// allow user-defined conversions via constructors or conversion 2854/// operators. 2855void 2856Sema::AddMethodCandidate(CXXMethodDecl *Method, DeclAccessPair FoundDecl, 2857 CXXRecordDecl *ActingContext, QualType ObjectType, 2858 Expr **Args, unsigned NumArgs, 2859 OverloadCandidateSet& CandidateSet, 2860 bool SuppressUserConversions) { 2861 const FunctionProtoType* Proto 2862 = dyn_cast<FunctionProtoType>(Method->getType()->getAs<FunctionType>()); 2863 assert(Proto && "Methods without a prototype cannot be overloaded"); 2864 assert(!isa<CXXConstructorDecl>(Method) && 2865 "Use AddOverloadCandidate for constructors"); 2866 2867 if (!CandidateSet.isNewCandidate(Method)) 2868 return; 2869 2870 // Overload resolution is always an unevaluated context. 2871 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 2872 2873 // Add this candidate 2874 CandidateSet.push_back(OverloadCandidate()); 2875 OverloadCandidate& Candidate = CandidateSet.back(); 2876 Candidate.FoundDecl = FoundDecl; 2877 Candidate.Function = Method; 2878 Candidate.IsSurrogate = false; 2879 Candidate.IgnoreObjectArgument = false; 2880 2881 unsigned NumArgsInProto = Proto->getNumArgs(); 2882 2883 // (C++ 13.3.2p2): A candidate function having fewer than m 2884 // parameters is viable only if it has an ellipsis in its parameter 2885 // list (8.3.5). 2886 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 2887 Candidate.Viable = false; 2888 Candidate.FailureKind = ovl_fail_too_many_arguments; 2889 return; 2890 } 2891 2892 // (C++ 13.3.2p2): A candidate function having more than m parameters 2893 // is viable only if the (m+1)st parameter has a default argument 2894 // (8.3.6). For the purposes of overload resolution, the 2895 // parameter list is truncated on the right, so that there are 2896 // exactly m parameters. 2897 unsigned MinRequiredArgs = Method->getMinRequiredArguments(); 2898 if (NumArgs < MinRequiredArgs) { 2899 // Not enough arguments. 2900 Candidate.Viable = false; 2901 Candidate.FailureKind = ovl_fail_too_few_arguments; 2902 return; 2903 } 2904 2905 Candidate.Viable = true; 2906 Candidate.Conversions.resize(NumArgs + 1); 2907 2908 if (Method->isStatic() || ObjectType.isNull()) 2909 // The implicit object argument is ignored. 2910 Candidate.IgnoreObjectArgument = true; 2911 else { 2912 // Determine the implicit conversion sequence for the object 2913 // parameter. 2914 Candidate.Conversions[0] 2915 = TryObjectArgumentInitialization(ObjectType, Method, ActingContext); 2916 if (Candidate.Conversions[0].isBad()) { 2917 Candidate.Viable = false; 2918 Candidate.FailureKind = ovl_fail_bad_conversion; 2919 return; 2920 } 2921 } 2922 2923 // Determine the implicit conversion sequences for each of the 2924 // arguments. 2925 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2926 if (ArgIdx < NumArgsInProto) { 2927 // (C++ 13.3.2p3): for F to be a viable function, there shall 2928 // exist for each argument an implicit conversion sequence 2929 // (13.3.3.1) that converts that argument to the corresponding 2930 // parameter of F. 2931 QualType ParamType = Proto->getArgType(ArgIdx); 2932 Candidate.Conversions[ArgIdx + 1] 2933 = TryCopyInitialization(Args[ArgIdx], ParamType, 2934 SuppressUserConversions, 2935 /*ForceRValue=*/false, 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 if (!CandidateSet.isNewCandidate(MethodTmpl)) 2964 return; 2965 2966 // C++ [over.match.funcs]p7: 2967 // In each case where a candidate is a function template, candidate 2968 // function template specializations are generated using template argument 2969 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 2970 // candidate functions in the usual way.113) A given name can refer to one 2971 // or more function templates and also to a set of overloaded non-template 2972 // functions. In such a case, the candidate functions generated from each 2973 // function template are combined with the set of non-template candidate 2974 // functions. 2975 TemplateDeductionInfo Info(Context, CandidateSet.getLocation()); 2976 FunctionDecl *Specialization = 0; 2977 if (TemplateDeductionResult Result 2978 = DeduceTemplateArguments(MethodTmpl, ExplicitTemplateArgs, 2979 Args, NumArgs, Specialization, Info)) { 2980 // FIXME: Record what happened with template argument deduction, so 2981 // that we can give the user a beautiful diagnostic. 2982 (void)Result; 2983 return; 2984 } 2985 2986 // Add the function template specialization produced by template argument 2987 // deduction as a candidate. 2988 assert(Specialization && "Missing member function template specialization?"); 2989 assert(isa<CXXMethodDecl>(Specialization) && 2990 "Specialization is not a member function?"); 2991 AddMethodCandidate(cast<CXXMethodDecl>(Specialization), FoundDecl, 2992 ActingContext, ObjectType, Args, NumArgs, 2993 CandidateSet, SuppressUserConversions); 2994} 2995 2996/// \brief Add a C++ function template specialization as a candidate 2997/// in the candidate set, using template argument deduction to produce 2998/// an appropriate function template specialization. 2999void 3000Sema::AddTemplateOverloadCandidate(FunctionTemplateDecl *FunctionTemplate, 3001 DeclAccessPair FoundDecl, 3002 const TemplateArgumentListInfo *ExplicitTemplateArgs, 3003 Expr **Args, unsigned NumArgs, 3004 OverloadCandidateSet& CandidateSet, 3005 bool SuppressUserConversions) { 3006 if (!CandidateSet.isNewCandidate(FunctionTemplate)) 3007 return; 3008 3009 // C++ [over.match.funcs]p7: 3010 // In each case where a candidate is a function template, candidate 3011 // function template specializations are generated using template argument 3012 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 3013 // candidate functions in the usual way.113) A given name can refer to one 3014 // or more function templates and also to a set of overloaded non-template 3015 // functions. In such a case, the candidate functions generated from each 3016 // function template are combined with the set of non-template candidate 3017 // functions. 3018 TemplateDeductionInfo Info(Context, CandidateSet.getLocation()); 3019 FunctionDecl *Specialization = 0; 3020 if (TemplateDeductionResult Result 3021 = DeduceTemplateArguments(FunctionTemplate, ExplicitTemplateArgs, 3022 Args, NumArgs, Specialization, Info)) { 3023 CandidateSet.push_back(OverloadCandidate()); 3024 OverloadCandidate &Candidate = CandidateSet.back(); 3025 Candidate.FoundDecl = FoundDecl; 3026 Candidate.Function = FunctionTemplate->getTemplatedDecl(); 3027 Candidate.Viable = false; 3028 Candidate.FailureKind = ovl_fail_bad_deduction; 3029 Candidate.IsSurrogate = false; 3030 Candidate.IgnoreObjectArgument = false; 3031 3032 // TODO: record more information about failed template arguments 3033 Candidate.DeductionFailure.Result = Result; 3034 Candidate.DeductionFailure.TemplateParameter = Info.Param.getOpaqueValue(); 3035 return; 3036 } 3037 3038 // Add the function template specialization produced by template argument 3039 // deduction as a candidate. 3040 assert(Specialization && "Missing function template specialization?"); 3041 AddOverloadCandidate(Specialization, FoundDecl, Args, NumArgs, CandidateSet, 3042 SuppressUserConversions); 3043} 3044 3045/// AddConversionCandidate - Add a C++ conversion function as a 3046/// candidate in the candidate set (C++ [over.match.conv], 3047/// C++ [over.match.copy]). From is the expression we're converting from, 3048/// and ToType is the type that we're eventually trying to convert to 3049/// (which may or may not be the same type as the type that the 3050/// conversion function produces). 3051void 3052Sema::AddConversionCandidate(CXXConversionDecl *Conversion, 3053 DeclAccessPair FoundDecl, 3054 CXXRecordDecl *ActingContext, 3055 Expr *From, QualType ToType, 3056 OverloadCandidateSet& CandidateSet) { 3057 assert(!Conversion->getDescribedFunctionTemplate() && 3058 "Conversion function templates use AddTemplateConversionCandidate"); 3059 3060 if (!CandidateSet.isNewCandidate(Conversion)) 3061 return; 3062 3063 // Overload resolution is always an unevaluated context. 3064 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 3065 3066 // Add this candidate 3067 CandidateSet.push_back(OverloadCandidate()); 3068 OverloadCandidate& Candidate = CandidateSet.back(); 3069 Candidate.FoundDecl = FoundDecl; 3070 Candidate.Function = Conversion; 3071 Candidate.IsSurrogate = false; 3072 Candidate.IgnoreObjectArgument = false; 3073 Candidate.FinalConversion.setAsIdentityConversion(); 3074 Candidate.FinalConversion.setFromType(Conversion->getConversionType()); 3075 Candidate.FinalConversion.setAllToTypes(ToType); 3076 3077 // Determine the implicit conversion sequence for the implicit 3078 // object parameter. 3079 Candidate.Viable = true; 3080 Candidate.Conversions.resize(1); 3081 Candidate.Conversions[0] 3082 = TryObjectArgumentInitialization(From->getType(), Conversion, 3083 ActingContext); 3084 // Conversion functions to a different type in the base class is visible in 3085 // the derived class. So, a derived to base conversion should not participate 3086 // in overload resolution. 3087 if (Candidate.Conversions[0].Standard.Second == ICK_Derived_To_Base) 3088 Candidate.Conversions[0].Standard.Second = ICK_Identity; 3089 if (Candidate.Conversions[0].isBad()) { 3090 Candidate.Viable = false; 3091 Candidate.FailureKind = ovl_fail_bad_conversion; 3092 return; 3093 } 3094 3095 // We won't go through a user-define type conversion function to convert a 3096 // derived to base as such conversions are given Conversion Rank. They only 3097 // go through a copy constructor. 13.3.3.1.2-p4 [over.ics.user] 3098 QualType FromCanon 3099 = Context.getCanonicalType(From->getType().getUnqualifiedType()); 3100 QualType ToCanon = Context.getCanonicalType(ToType).getUnqualifiedType(); 3101 if (FromCanon == ToCanon || IsDerivedFrom(FromCanon, ToCanon)) { 3102 Candidate.Viable = false; 3103 Candidate.FailureKind = ovl_fail_trivial_conversion; 3104 return; 3105 } 3106 3107 3108 // To determine what the conversion from the result of calling the 3109 // conversion function to the type we're eventually trying to 3110 // convert to (ToType), we need to synthesize a call to the 3111 // conversion function and attempt copy initialization from it. This 3112 // makes sure that we get the right semantics with respect to 3113 // lvalues/rvalues and the type. Fortunately, we can allocate this 3114 // call on the stack and we don't need its arguments to be 3115 // well-formed. 3116 DeclRefExpr ConversionRef(Conversion, Conversion->getType(), 3117 From->getLocStart()); 3118 ImplicitCastExpr ConversionFn(Context.getPointerType(Conversion->getType()), 3119 CastExpr::CK_FunctionToPointerDecay, 3120 &ConversionRef, false); 3121 3122 // Note that it is safe to allocate CallExpr on the stack here because 3123 // there are 0 arguments (i.e., nothing is allocated using ASTContext's 3124 // allocator). 3125 CallExpr Call(Context, &ConversionFn, 0, 0, 3126 Conversion->getConversionType().getNonReferenceType(), 3127 From->getLocStart()); 3128 ImplicitConversionSequence ICS = 3129 TryCopyInitialization(&Call, ToType, 3130 /*SuppressUserConversions=*/true, 3131 /*ForceRValue=*/false, 3132 /*InOverloadResolution=*/false); 3133 3134 switch (ICS.getKind()) { 3135 case ImplicitConversionSequence::StandardConversion: 3136 Candidate.FinalConversion = ICS.Standard; 3137 3138 // C++ [over.ics.user]p3: 3139 // If the user-defined conversion is specified by a specialization of a 3140 // conversion function template, the second standard conversion sequence 3141 // shall have exact match rank. 3142 if (Conversion->getPrimaryTemplate() && 3143 GetConversionRank(ICS.Standard.Second) != ICR_Exact_Match) { 3144 Candidate.Viable = false; 3145 Candidate.FailureKind = ovl_fail_final_conversion_not_exact; 3146 } 3147 3148 break; 3149 3150 case ImplicitConversionSequence::BadConversion: 3151 Candidate.Viable = false; 3152 Candidate.FailureKind = ovl_fail_bad_final_conversion; 3153 break; 3154 3155 default: 3156 assert(false && 3157 "Can only end up with a standard conversion sequence or failure"); 3158 } 3159} 3160 3161/// \brief Adds a conversion function template specialization 3162/// candidate to the overload set, using template argument deduction 3163/// to deduce the template arguments of the conversion function 3164/// template from the type that we are converting to (C++ 3165/// [temp.deduct.conv]). 3166void 3167Sema::AddTemplateConversionCandidate(FunctionTemplateDecl *FunctionTemplate, 3168 DeclAccessPair FoundDecl, 3169 CXXRecordDecl *ActingDC, 3170 Expr *From, QualType ToType, 3171 OverloadCandidateSet &CandidateSet) { 3172 assert(isa<CXXConversionDecl>(FunctionTemplate->getTemplatedDecl()) && 3173 "Only conversion function templates permitted here"); 3174 3175 if (!CandidateSet.isNewCandidate(FunctionTemplate)) 3176 return; 3177 3178 TemplateDeductionInfo Info(Context, CandidateSet.getLocation()); 3179 CXXConversionDecl *Specialization = 0; 3180 if (TemplateDeductionResult Result 3181 = DeduceTemplateArguments(FunctionTemplate, ToType, 3182 Specialization, Info)) { 3183 // FIXME: Record what happened with template argument deduction, so 3184 // that we can give the user a beautiful diagnostic. 3185 (void)Result; 3186 return; 3187 } 3188 3189 // Add the conversion function template specialization produced by 3190 // template argument deduction as a candidate. 3191 assert(Specialization && "Missing function template specialization?"); 3192 AddConversionCandidate(Specialization, FoundDecl, ActingDC, From, ToType, 3193 CandidateSet); 3194} 3195 3196/// AddSurrogateCandidate - Adds a "surrogate" candidate function that 3197/// converts the given @c Object to a function pointer via the 3198/// conversion function @c Conversion, and then attempts to call it 3199/// with the given arguments (C++ [over.call.object]p2-4). Proto is 3200/// the type of function that we'll eventually be calling. 3201void Sema::AddSurrogateCandidate(CXXConversionDecl *Conversion, 3202 DeclAccessPair FoundDecl, 3203 CXXRecordDecl *ActingContext, 3204 const FunctionProtoType *Proto, 3205 QualType ObjectType, 3206 Expr **Args, unsigned NumArgs, 3207 OverloadCandidateSet& CandidateSet) { 3208 if (!CandidateSet.isNewCandidate(Conversion)) 3209 return; 3210 3211 // Overload resolution is always an unevaluated context. 3212 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 3213 3214 CandidateSet.push_back(OverloadCandidate()); 3215 OverloadCandidate& Candidate = CandidateSet.back(); 3216 Candidate.FoundDecl = FoundDecl; 3217 Candidate.Function = 0; 3218 Candidate.Surrogate = Conversion; 3219 Candidate.Viable = true; 3220 Candidate.IsSurrogate = true; 3221 Candidate.IgnoreObjectArgument = false; 3222 Candidate.Conversions.resize(NumArgs + 1); 3223 3224 // Determine the implicit conversion sequence for the implicit 3225 // object parameter. 3226 ImplicitConversionSequence ObjectInit 3227 = TryObjectArgumentInitialization(ObjectType, Conversion, ActingContext); 3228 if (ObjectInit.isBad()) { 3229 Candidate.Viable = false; 3230 Candidate.FailureKind = ovl_fail_bad_conversion; 3231 Candidate.Conversions[0] = ObjectInit; 3232 return; 3233 } 3234 3235 // The first conversion is actually a user-defined conversion whose 3236 // first conversion is ObjectInit's standard conversion (which is 3237 // effectively a reference binding). Record it as such. 3238 Candidate.Conversions[0].setUserDefined(); 3239 Candidate.Conversions[0].UserDefined.Before = ObjectInit.Standard; 3240 Candidate.Conversions[0].UserDefined.EllipsisConversion = false; 3241 Candidate.Conversions[0].UserDefined.ConversionFunction = Conversion; 3242 Candidate.Conversions[0].UserDefined.After 3243 = Candidate.Conversions[0].UserDefined.Before; 3244 Candidate.Conversions[0].UserDefined.After.setAsIdentityConversion(); 3245 3246 // Find the 3247 unsigned NumArgsInProto = Proto->getNumArgs(); 3248 3249 // (C++ 13.3.2p2): A candidate function having fewer than m 3250 // parameters is viable only if it has an ellipsis in its parameter 3251 // list (8.3.5). 3252 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 3253 Candidate.Viable = false; 3254 Candidate.FailureKind = ovl_fail_too_many_arguments; 3255 return; 3256 } 3257 3258 // Function types don't have any default arguments, so just check if 3259 // we have enough arguments. 3260 if (NumArgs < NumArgsInProto) { 3261 // Not enough arguments. 3262 Candidate.Viable = false; 3263 Candidate.FailureKind = ovl_fail_too_few_arguments; 3264 return; 3265 } 3266 3267 // Determine the implicit conversion sequences for each of the 3268 // arguments. 3269 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 3270 if (ArgIdx < NumArgsInProto) { 3271 // (C++ 13.3.2p3): for F to be a viable function, there shall 3272 // exist for each argument an implicit conversion sequence 3273 // (13.3.3.1) that converts that argument to the corresponding 3274 // parameter of F. 3275 QualType ParamType = Proto->getArgType(ArgIdx); 3276 Candidate.Conversions[ArgIdx + 1] 3277 = TryCopyInitialization(Args[ArgIdx], ParamType, 3278 /*SuppressUserConversions=*/false, 3279 /*ForceRValue=*/false, 3280 /*InOverloadResolution=*/false); 3281 if (Candidate.Conversions[ArgIdx + 1].isBad()) { 3282 Candidate.Viable = false; 3283 Candidate.FailureKind = ovl_fail_bad_conversion; 3284 break; 3285 } 3286 } else { 3287 // (C++ 13.3.2p2): For the purposes of overload resolution, any 3288 // argument for which there is no corresponding parameter is 3289 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 3290 Candidate.Conversions[ArgIdx + 1].setEllipsis(); 3291 } 3292 } 3293} 3294 3295// FIXME: This will eventually be removed, once we've migrated all of the 3296// operator overloading logic over to the scheme used by binary operators, which 3297// works for template instantiation. 3298void Sema::AddOperatorCandidates(OverloadedOperatorKind Op, Scope *S, 3299 SourceLocation OpLoc, 3300 Expr **Args, unsigned NumArgs, 3301 OverloadCandidateSet& CandidateSet, 3302 SourceRange OpRange) { 3303 UnresolvedSet<16> Fns; 3304 3305 QualType T1 = Args[0]->getType(); 3306 QualType T2; 3307 if (NumArgs > 1) 3308 T2 = Args[1]->getType(); 3309 3310 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 3311 if (S) 3312 LookupOverloadedOperatorName(Op, S, T1, T2, Fns); 3313 AddFunctionCandidates(Fns, Args, NumArgs, CandidateSet, false); 3314 AddArgumentDependentLookupCandidates(OpName, false, Args, NumArgs, 0, 3315 CandidateSet); 3316 AddMemberOperatorCandidates(Op, OpLoc, Args, NumArgs, CandidateSet, OpRange); 3317 AddBuiltinOperatorCandidates(Op, OpLoc, Args, NumArgs, CandidateSet); 3318} 3319 3320/// \brief Add overload candidates for overloaded operators that are 3321/// member functions. 3322/// 3323/// Add the overloaded operator candidates that are member functions 3324/// for the operator Op that was used in an operator expression such 3325/// as "x Op y". , Args/NumArgs provides the operator arguments, and 3326/// CandidateSet will store the added overload candidates. (C++ 3327/// [over.match.oper]). 3328void Sema::AddMemberOperatorCandidates(OverloadedOperatorKind Op, 3329 SourceLocation OpLoc, 3330 Expr **Args, unsigned NumArgs, 3331 OverloadCandidateSet& CandidateSet, 3332 SourceRange OpRange) { 3333 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 3334 3335 // C++ [over.match.oper]p3: 3336 // For a unary operator @ with an operand of a type whose 3337 // cv-unqualified version is T1, and for a binary operator @ with 3338 // a left operand of a type whose cv-unqualified version is T1 and 3339 // a right operand of a type whose cv-unqualified version is T2, 3340 // three sets of candidate functions, designated member 3341 // candidates, non-member candidates and built-in candidates, are 3342 // constructed as follows: 3343 QualType T1 = Args[0]->getType(); 3344 QualType T2; 3345 if (NumArgs > 1) 3346 T2 = Args[1]->getType(); 3347 3348 // -- If T1 is a class type, the set of member candidates is the 3349 // result of the qualified lookup of T1::operator@ 3350 // (13.3.1.1.1); otherwise, the set of member candidates is 3351 // empty. 3352 if (const RecordType *T1Rec = T1->getAs<RecordType>()) { 3353 // Complete the type if it can be completed. Otherwise, we're done. 3354 if (RequireCompleteType(OpLoc, T1, PDiag())) 3355 return; 3356 3357 LookupResult Operators(*this, OpName, OpLoc, LookupOrdinaryName); 3358 LookupQualifiedName(Operators, T1Rec->getDecl()); 3359 Operators.suppressDiagnostics(); 3360 3361 for (LookupResult::iterator Oper = Operators.begin(), 3362 OperEnd = Operators.end(); 3363 Oper != OperEnd; 3364 ++Oper) 3365 AddMethodCandidate(Oper.getPair(), Args[0]->getType(), 3366 Args + 1, NumArgs - 1, CandidateSet, 3367 /* SuppressUserConversions = */ false); 3368 } 3369} 3370 3371/// AddBuiltinCandidate - Add a candidate for a built-in 3372/// operator. ResultTy and ParamTys are the result and parameter types 3373/// of the built-in candidate, respectively. Args and NumArgs are the 3374/// arguments being passed to the candidate. IsAssignmentOperator 3375/// should be true when this built-in candidate is an assignment 3376/// operator. NumContextualBoolArguments is the number of arguments 3377/// (at the beginning of the argument list) that will be contextually 3378/// converted to bool. 3379void Sema::AddBuiltinCandidate(QualType ResultTy, QualType *ParamTys, 3380 Expr **Args, unsigned NumArgs, 3381 OverloadCandidateSet& CandidateSet, 3382 bool IsAssignmentOperator, 3383 unsigned NumContextualBoolArguments) { 3384 // Overload resolution is always an unevaluated context. 3385 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 3386 3387 // Add this candidate 3388 CandidateSet.push_back(OverloadCandidate()); 3389 OverloadCandidate& Candidate = CandidateSet.back(); 3390 Candidate.FoundDecl = DeclAccessPair::make(0, AS_none); 3391 Candidate.Function = 0; 3392 Candidate.IsSurrogate = false; 3393 Candidate.IgnoreObjectArgument = false; 3394 Candidate.BuiltinTypes.ResultTy = ResultTy; 3395 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 3396 Candidate.BuiltinTypes.ParamTypes[ArgIdx] = ParamTys[ArgIdx]; 3397 3398 // Determine the implicit conversion sequences for each of the 3399 // arguments. 3400 Candidate.Viable = true; 3401 Candidate.Conversions.resize(NumArgs); 3402 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 3403 // C++ [over.match.oper]p4: 3404 // For the built-in assignment operators, conversions of the 3405 // left operand are restricted as follows: 3406 // -- no temporaries are introduced to hold the left operand, and 3407 // -- no user-defined conversions are applied to the left 3408 // operand to achieve a type match with the left-most 3409 // parameter of a built-in candidate. 3410 // 3411 // We block these conversions by turning off user-defined 3412 // conversions, since that is the only way that initialization of 3413 // a reference to a non-class type can occur from something that 3414 // is not of the same type. 3415 if (ArgIdx < NumContextualBoolArguments) { 3416 assert(ParamTys[ArgIdx] == Context.BoolTy && 3417 "Contextual conversion to bool requires bool type"); 3418 Candidate.Conversions[ArgIdx] = TryContextuallyConvertToBool(Args[ArgIdx]); 3419 } else { 3420 Candidate.Conversions[ArgIdx] 3421 = TryCopyInitialization(Args[ArgIdx], ParamTys[ArgIdx], 3422 ArgIdx == 0 && IsAssignmentOperator, 3423 /*ForceRValue=*/false, 3424 /*InOverloadResolution=*/false); 3425 } 3426 if (Candidate.Conversions[ArgIdx].isBad()) { 3427 Candidate.Viable = false; 3428 Candidate.FailureKind = ovl_fail_bad_conversion; 3429 break; 3430 } 3431 } 3432} 3433 3434/// BuiltinCandidateTypeSet - A set of types that will be used for the 3435/// candidate operator functions for built-in operators (C++ 3436/// [over.built]). The types are separated into pointer types and 3437/// enumeration types. 3438class BuiltinCandidateTypeSet { 3439 /// TypeSet - A set of types. 3440 typedef llvm::SmallPtrSet<QualType, 8> TypeSet; 3441 3442 /// PointerTypes - The set of pointer types that will be used in the 3443 /// built-in candidates. 3444 TypeSet PointerTypes; 3445 3446 /// MemberPointerTypes - The set of member pointer types that will be 3447 /// used in the built-in candidates. 3448 TypeSet MemberPointerTypes; 3449 3450 /// EnumerationTypes - The set of enumeration types that will be 3451 /// used in the built-in candidates. 3452 TypeSet EnumerationTypes; 3453 3454 /// Sema - The semantic analysis instance where we are building the 3455 /// candidate type set. 3456 Sema &SemaRef; 3457 3458 /// Context - The AST context in which we will build the type sets. 3459 ASTContext &Context; 3460 3461 bool AddPointerWithMoreQualifiedTypeVariants(QualType Ty, 3462 const Qualifiers &VisibleQuals); 3463 bool AddMemberPointerWithMoreQualifiedTypeVariants(QualType Ty); 3464 3465public: 3466 /// iterator - Iterates through the types that are part of the set. 3467 typedef TypeSet::iterator iterator; 3468 3469 BuiltinCandidateTypeSet(Sema &SemaRef) 3470 : SemaRef(SemaRef), Context(SemaRef.Context) { } 3471 3472 void AddTypesConvertedFrom(QualType Ty, 3473 SourceLocation Loc, 3474 bool AllowUserConversions, 3475 bool AllowExplicitConversions, 3476 const Qualifiers &VisibleTypeConversionsQuals); 3477 3478 /// pointer_begin - First pointer type found; 3479 iterator pointer_begin() { return PointerTypes.begin(); } 3480 3481 /// pointer_end - Past the last pointer type found; 3482 iterator pointer_end() { return PointerTypes.end(); } 3483 3484 /// member_pointer_begin - First member pointer type found; 3485 iterator member_pointer_begin() { return MemberPointerTypes.begin(); } 3486 3487 /// member_pointer_end - Past the last member pointer type found; 3488 iterator member_pointer_end() { return MemberPointerTypes.end(); } 3489 3490 /// enumeration_begin - First enumeration type found; 3491 iterator enumeration_begin() { return EnumerationTypes.begin(); } 3492 3493 /// enumeration_end - Past the last enumeration type found; 3494 iterator enumeration_end() { return EnumerationTypes.end(); } 3495}; 3496 3497/// AddPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty to 3498/// the set of pointer types along with any more-qualified variants of 3499/// that type. For example, if @p Ty is "int const *", this routine 3500/// will add "int const *", "int const volatile *", "int const 3501/// restrict *", and "int const volatile restrict *" to the set of 3502/// pointer types. Returns true if the add of @p Ty itself succeeded, 3503/// false otherwise. 3504/// 3505/// FIXME: what to do about extended qualifiers? 3506bool 3507BuiltinCandidateTypeSet::AddPointerWithMoreQualifiedTypeVariants(QualType Ty, 3508 const Qualifiers &VisibleQuals) { 3509 3510 // Insert this type. 3511 if (!PointerTypes.insert(Ty)) 3512 return false; 3513 3514 const PointerType *PointerTy = Ty->getAs<PointerType>(); 3515 assert(PointerTy && "type was not a pointer type!"); 3516 3517 QualType PointeeTy = PointerTy->getPointeeType(); 3518 // Don't add qualified variants of arrays. For one, they're not allowed 3519 // (the qualifier would sink to the element type), and for another, the 3520 // only overload situation where it matters is subscript or pointer +- int, 3521 // and those shouldn't have qualifier variants anyway. 3522 if (PointeeTy->isArrayType()) 3523 return true; 3524 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 3525 if (const ConstantArrayType *Array =Context.getAsConstantArrayType(PointeeTy)) 3526 BaseCVR = Array->getElementType().getCVRQualifiers(); 3527 bool hasVolatile = VisibleQuals.hasVolatile(); 3528 bool hasRestrict = VisibleQuals.hasRestrict(); 3529 3530 // Iterate through all strict supersets of BaseCVR. 3531 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 3532 if ((CVR | BaseCVR) != CVR) continue; 3533 // Skip over Volatile/Restrict if no Volatile/Restrict found anywhere 3534 // in the types. 3535 if ((CVR & Qualifiers::Volatile) && !hasVolatile) continue; 3536 if ((CVR & Qualifiers::Restrict) && !hasRestrict) continue; 3537 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 3538 PointerTypes.insert(Context.getPointerType(QPointeeTy)); 3539 } 3540 3541 return true; 3542} 3543 3544/// AddMemberPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty 3545/// to the set of pointer types along with any more-qualified variants of 3546/// that type. For example, if @p Ty is "int const *", this routine 3547/// will add "int const *", "int const volatile *", "int const 3548/// restrict *", and "int const volatile restrict *" to the set of 3549/// pointer types. Returns true if the add of @p Ty itself succeeded, 3550/// false otherwise. 3551/// 3552/// FIXME: what to do about extended qualifiers? 3553bool 3554BuiltinCandidateTypeSet::AddMemberPointerWithMoreQualifiedTypeVariants( 3555 QualType Ty) { 3556 // Insert this type. 3557 if (!MemberPointerTypes.insert(Ty)) 3558 return false; 3559 3560 const MemberPointerType *PointerTy = Ty->getAs<MemberPointerType>(); 3561 assert(PointerTy && "type was not a member pointer type!"); 3562 3563 QualType PointeeTy = PointerTy->getPointeeType(); 3564 // Don't add qualified variants of arrays. For one, they're not allowed 3565 // (the qualifier would sink to the element type), and for another, the 3566 // only overload situation where it matters is subscript or pointer +- int, 3567 // and those shouldn't have qualifier variants anyway. 3568 if (PointeeTy->isArrayType()) 3569 return true; 3570 const Type *ClassTy = PointerTy->getClass(); 3571 3572 // Iterate through all strict supersets of the pointee type's CVR 3573 // qualifiers. 3574 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 3575 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 3576 if ((CVR | BaseCVR) != CVR) continue; 3577 3578 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 3579 MemberPointerTypes.insert(Context.getMemberPointerType(QPointeeTy, ClassTy)); 3580 } 3581 3582 return true; 3583} 3584 3585/// AddTypesConvertedFrom - Add each of the types to which the type @p 3586/// Ty can be implicit converted to the given set of @p Types. We're 3587/// primarily interested in pointer types and enumeration types. We also 3588/// take member pointer types, for the conditional operator. 3589/// AllowUserConversions is true if we should look at the conversion 3590/// functions of a class type, and AllowExplicitConversions if we 3591/// should also include the explicit conversion functions of a class 3592/// type. 3593void 3594BuiltinCandidateTypeSet::AddTypesConvertedFrom(QualType Ty, 3595 SourceLocation Loc, 3596 bool AllowUserConversions, 3597 bool AllowExplicitConversions, 3598 const Qualifiers &VisibleQuals) { 3599 // Only deal with canonical types. 3600 Ty = Context.getCanonicalType(Ty); 3601 3602 // Look through reference types; they aren't part of the type of an 3603 // expression for the purposes of conversions. 3604 if (const ReferenceType *RefTy = Ty->getAs<ReferenceType>()) 3605 Ty = RefTy->getPointeeType(); 3606 3607 // We don't care about qualifiers on the type. 3608 Ty = Ty.getLocalUnqualifiedType(); 3609 3610 // If we're dealing with an array type, decay to the pointer. 3611 if (Ty->isArrayType()) 3612 Ty = SemaRef.Context.getArrayDecayedType(Ty); 3613 3614 if (const PointerType *PointerTy = Ty->getAs<PointerType>()) { 3615 QualType PointeeTy = PointerTy->getPointeeType(); 3616 3617 // Insert our type, and its more-qualified variants, into the set 3618 // of types. 3619 if (!AddPointerWithMoreQualifiedTypeVariants(Ty, VisibleQuals)) 3620 return; 3621 } else if (Ty->isMemberPointerType()) { 3622 // Member pointers are far easier, since the pointee can't be converted. 3623 if (!AddMemberPointerWithMoreQualifiedTypeVariants(Ty)) 3624 return; 3625 } else if (Ty->isEnumeralType()) { 3626 EnumerationTypes.insert(Ty); 3627 } else if (AllowUserConversions) { 3628 if (const RecordType *TyRec = Ty->getAs<RecordType>()) { 3629 if (SemaRef.RequireCompleteType(Loc, Ty, 0)) { 3630 // No conversion functions in incomplete types. 3631 return; 3632 } 3633 3634 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 3635 const UnresolvedSetImpl *Conversions 3636 = ClassDecl->getVisibleConversionFunctions(); 3637 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 3638 E = Conversions->end(); I != E; ++I) { 3639 NamedDecl *D = I.getDecl(); 3640 if (isa<UsingShadowDecl>(D)) 3641 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 3642 3643 // Skip conversion function templates; they don't tell us anything 3644 // about which builtin types we can convert to. 3645 if (isa<FunctionTemplateDecl>(D)) 3646 continue; 3647 3648 CXXConversionDecl *Conv = cast<CXXConversionDecl>(D); 3649 if (AllowExplicitConversions || !Conv->isExplicit()) { 3650 AddTypesConvertedFrom(Conv->getConversionType(), Loc, false, false, 3651 VisibleQuals); 3652 } 3653 } 3654 } 3655 } 3656} 3657 3658/// \brief Helper function for AddBuiltinOperatorCandidates() that adds 3659/// the volatile- and non-volatile-qualified assignment operators for the 3660/// given type to the candidate set. 3661static void AddBuiltinAssignmentOperatorCandidates(Sema &S, 3662 QualType T, 3663 Expr **Args, 3664 unsigned NumArgs, 3665 OverloadCandidateSet &CandidateSet) { 3666 QualType ParamTypes[2]; 3667 3668 // T& operator=(T&, T) 3669 ParamTypes[0] = S.Context.getLValueReferenceType(T); 3670 ParamTypes[1] = T; 3671 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3672 /*IsAssignmentOperator=*/true); 3673 3674 if (!S.Context.getCanonicalType(T).isVolatileQualified()) { 3675 // volatile T& operator=(volatile T&, T) 3676 ParamTypes[0] 3677 = S.Context.getLValueReferenceType(S.Context.getVolatileType(T)); 3678 ParamTypes[1] = T; 3679 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3680 /*IsAssignmentOperator=*/true); 3681 } 3682} 3683 3684/// CollectVRQualifiers - This routine returns Volatile/Restrict qualifiers, 3685/// if any, found in visible type conversion functions found in ArgExpr's type. 3686static Qualifiers CollectVRQualifiers(ASTContext &Context, Expr* ArgExpr) { 3687 Qualifiers VRQuals; 3688 const RecordType *TyRec; 3689 if (const MemberPointerType *RHSMPType = 3690 ArgExpr->getType()->getAs<MemberPointerType>()) 3691 TyRec = cast<RecordType>(RHSMPType->getClass()); 3692 else 3693 TyRec = ArgExpr->getType()->getAs<RecordType>(); 3694 if (!TyRec) { 3695 // Just to be safe, assume the worst case. 3696 VRQuals.addVolatile(); 3697 VRQuals.addRestrict(); 3698 return VRQuals; 3699 } 3700 3701 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 3702 if (!ClassDecl->hasDefinition()) 3703 return VRQuals; 3704 3705 const UnresolvedSetImpl *Conversions = 3706 ClassDecl->getVisibleConversionFunctions(); 3707 3708 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 3709 E = Conversions->end(); I != E; ++I) { 3710 NamedDecl *D = I.getDecl(); 3711 if (isa<UsingShadowDecl>(D)) 3712 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 3713 if (CXXConversionDecl *Conv = dyn_cast<CXXConversionDecl>(D)) { 3714 QualType CanTy = Context.getCanonicalType(Conv->getConversionType()); 3715 if (const ReferenceType *ResTypeRef = CanTy->getAs<ReferenceType>()) 3716 CanTy = ResTypeRef->getPointeeType(); 3717 // Need to go down the pointer/mempointer chain and add qualifiers 3718 // as see them. 3719 bool done = false; 3720 while (!done) { 3721 if (const PointerType *ResTypePtr = CanTy->getAs<PointerType>()) 3722 CanTy = ResTypePtr->getPointeeType(); 3723 else if (const MemberPointerType *ResTypeMPtr = 3724 CanTy->getAs<MemberPointerType>()) 3725 CanTy = ResTypeMPtr->getPointeeType(); 3726 else 3727 done = true; 3728 if (CanTy.isVolatileQualified()) 3729 VRQuals.addVolatile(); 3730 if (CanTy.isRestrictQualified()) 3731 VRQuals.addRestrict(); 3732 if (VRQuals.hasRestrict() && VRQuals.hasVolatile()) 3733 return VRQuals; 3734 } 3735 } 3736 } 3737 return VRQuals; 3738} 3739 3740/// AddBuiltinOperatorCandidates - Add the appropriate built-in 3741/// operator overloads to the candidate set (C++ [over.built]), based 3742/// on the operator @p Op and the arguments given. For example, if the 3743/// operator is a binary '+', this routine might add "int 3744/// operator+(int, int)" to cover integer addition. 3745void 3746Sema::AddBuiltinOperatorCandidates(OverloadedOperatorKind Op, 3747 SourceLocation OpLoc, 3748 Expr **Args, unsigned NumArgs, 3749 OverloadCandidateSet& CandidateSet) { 3750 // The set of "promoted arithmetic types", which are the arithmetic 3751 // types are that preserved by promotion (C++ [over.built]p2). Note 3752 // that the first few of these types are the promoted integral 3753 // types; these types need to be first. 3754 // FIXME: What about complex? 3755 const unsigned FirstIntegralType = 0; 3756 const unsigned LastIntegralType = 13; 3757 const unsigned FirstPromotedIntegralType = 7, 3758 LastPromotedIntegralType = 13; 3759 const unsigned FirstPromotedArithmeticType = 7, 3760 LastPromotedArithmeticType = 16; 3761 const unsigned NumArithmeticTypes = 16; 3762 QualType ArithmeticTypes[NumArithmeticTypes] = { 3763 Context.BoolTy, Context.CharTy, Context.WCharTy, 3764// FIXME: Context.Char16Ty, Context.Char32Ty, 3765 Context.SignedCharTy, Context.ShortTy, 3766 Context.UnsignedCharTy, Context.UnsignedShortTy, 3767 Context.IntTy, Context.LongTy, Context.LongLongTy, 3768 Context.UnsignedIntTy, Context.UnsignedLongTy, Context.UnsignedLongLongTy, 3769 Context.FloatTy, Context.DoubleTy, Context.LongDoubleTy 3770 }; 3771 assert(ArithmeticTypes[FirstPromotedIntegralType] == Context.IntTy && 3772 "Invalid first promoted integral type"); 3773 assert(ArithmeticTypes[LastPromotedIntegralType - 1] 3774 == Context.UnsignedLongLongTy && 3775 "Invalid last promoted integral type"); 3776 assert(ArithmeticTypes[FirstPromotedArithmeticType] == Context.IntTy && 3777 "Invalid first promoted arithmetic type"); 3778 assert(ArithmeticTypes[LastPromotedArithmeticType - 1] 3779 == Context.LongDoubleTy && 3780 "Invalid last promoted arithmetic type"); 3781 3782 // Find all of the types that the arguments can convert to, but only 3783 // if the operator we're looking at has built-in operator candidates 3784 // that make use of these types. 3785 Qualifiers VisibleTypeConversionsQuals; 3786 VisibleTypeConversionsQuals.addConst(); 3787 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 3788 VisibleTypeConversionsQuals += CollectVRQualifiers(Context, Args[ArgIdx]); 3789 3790 BuiltinCandidateTypeSet CandidateTypes(*this); 3791 if (Op == OO_Less || Op == OO_Greater || Op == OO_LessEqual || 3792 Op == OO_GreaterEqual || Op == OO_EqualEqual || Op == OO_ExclaimEqual || 3793 Op == OO_Plus || (Op == OO_Minus && NumArgs == 2) || Op == OO_Equal || 3794 Op == OO_PlusEqual || Op == OO_MinusEqual || Op == OO_Subscript || 3795 Op == OO_ArrowStar || Op == OO_PlusPlus || Op == OO_MinusMinus || 3796 (Op == OO_Star && NumArgs == 1) || Op == OO_Conditional) { 3797 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 3798 CandidateTypes.AddTypesConvertedFrom(Args[ArgIdx]->getType(), 3799 OpLoc, 3800 true, 3801 (Op == OO_Exclaim || 3802 Op == OO_AmpAmp || 3803 Op == OO_PipePipe), 3804 VisibleTypeConversionsQuals); 3805 } 3806 3807 bool isComparison = false; 3808 switch (Op) { 3809 case OO_None: 3810 case NUM_OVERLOADED_OPERATORS: 3811 assert(false && "Expected an overloaded operator"); 3812 break; 3813 3814 case OO_Star: // '*' is either unary or binary 3815 if (NumArgs == 1) 3816 goto UnaryStar; 3817 else 3818 goto BinaryStar; 3819 break; 3820 3821 case OO_Plus: // '+' is either unary or binary 3822 if (NumArgs == 1) 3823 goto UnaryPlus; 3824 else 3825 goto BinaryPlus; 3826 break; 3827 3828 case OO_Minus: // '-' is either unary or binary 3829 if (NumArgs == 1) 3830 goto UnaryMinus; 3831 else 3832 goto BinaryMinus; 3833 break; 3834 3835 case OO_Amp: // '&' is either unary or binary 3836 if (NumArgs == 1) 3837 goto UnaryAmp; 3838 else 3839 goto BinaryAmp; 3840 3841 case OO_PlusPlus: 3842 case OO_MinusMinus: 3843 // C++ [over.built]p3: 3844 // 3845 // For every pair (T, VQ), where T is an arithmetic type, and VQ 3846 // is either volatile or empty, there exist candidate operator 3847 // functions of the form 3848 // 3849 // VQ T& operator++(VQ T&); 3850 // T operator++(VQ T&, int); 3851 // 3852 // C++ [over.built]p4: 3853 // 3854 // For every pair (T, VQ), where T is an arithmetic type other 3855 // than bool, and VQ is either volatile or empty, there exist 3856 // candidate operator functions of the form 3857 // 3858 // VQ T& operator--(VQ T&); 3859 // T operator--(VQ T&, int); 3860 for (unsigned Arith = (Op == OO_PlusPlus? 0 : 1); 3861 Arith < NumArithmeticTypes; ++Arith) { 3862 QualType ArithTy = ArithmeticTypes[Arith]; 3863 QualType ParamTypes[2] 3864 = { Context.getLValueReferenceType(ArithTy), Context.IntTy }; 3865 3866 // Non-volatile version. 3867 if (NumArgs == 1) 3868 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3869 else 3870 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 3871 // heuristic to reduce number of builtin candidates in the set. 3872 // Add volatile version only if there are conversions to a volatile type. 3873 if (VisibleTypeConversionsQuals.hasVolatile()) { 3874 // Volatile version 3875 ParamTypes[0] 3876 = Context.getLValueReferenceType(Context.getVolatileType(ArithTy)); 3877 if (NumArgs == 1) 3878 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3879 else 3880 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 3881 } 3882 } 3883 3884 // C++ [over.built]p5: 3885 // 3886 // For every pair (T, VQ), where T is a cv-qualified or 3887 // cv-unqualified object type, and VQ is either volatile or 3888 // empty, there exist candidate operator functions of the form 3889 // 3890 // T*VQ& operator++(T*VQ&); 3891 // T*VQ& operator--(T*VQ&); 3892 // T* operator++(T*VQ&, int); 3893 // T* operator--(T*VQ&, int); 3894 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3895 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3896 // Skip pointer types that aren't pointers to object types. 3897 if (!(*Ptr)->getAs<PointerType>()->getPointeeType()->isObjectType()) 3898 continue; 3899 3900 QualType ParamTypes[2] = { 3901 Context.getLValueReferenceType(*Ptr), Context.IntTy 3902 }; 3903 3904 // Without volatile 3905 if (NumArgs == 1) 3906 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3907 else 3908 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3909 3910 if (!Context.getCanonicalType(*Ptr).isVolatileQualified() && 3911 VisibleTypeConversionsQuals.hasVolatile()) { 3912 // With volatile 3913 ParamTypes[0] 3914 = Context.getLValueReferenceType(Context.getVolatileType(*Ptr)); 3915 if (NumArgs == 1) 3916 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3917 else 3918 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3919 } 3920 } 3921 break; 3922 3923 UnaryStar: 3924 // C++ [over.built]p6: 3925 // For every cv-qualified or cv-unqualified object type T, there 3926 // exist candidate operator functions of the form 3927 // 3928 // T& operator*(T*); 3929 // 3930 // C++ [over.built]p7: 3931 // For every function type T, there exist candidate operator 3932 // functions of the form 3933 // T& operator*(T*); 3934 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3935 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3936 QualType ParamTy = *Ptr; 3937 QualType PointeeTy = ParamTy->getAs<PointerType>()->getPointeeType(); 3938 AddBuiltinCandidate(Context.getLValueReferenceType(PointeeTy), 3939 &ParamTy, Args, 1, CandidateSet); 3940 } 3941 break; 3942 3943 UnaryPlus: 3944 // C++ [over.built]p8: 3945 // For every type T, there exist candidate operator functions of 3946 // the form 3947 // 3948 // T* operator+(T*); 3949 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3950 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3951 QualType ParamTy = *Ptr; 3952 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet); 3953 } 3954 3955 // Fall through 3956 3957 UnaryMinus: 3958 // C++ [over.built]p9: 3959 // For every promoted arithmetic type T, there exist candidate 3960 // operator functions of the form 3961 // 3962 // T operator+(T); 3963 // T operator-(T); 3964 for (unsigned Arith = FirstPromotedArithmeticType; 3965 Arith < LastPromotedArithmeticType; ++Arith) { 3966 QualType ArithTy = ArithmeticTypes[Arith]; 3967 AddBuiltinCandidate(ArithTy, &ArithTy, Args, 1, CandidateSet); 3968 } 3969 break; 3970 3971 case OO_Tilde: 3972 // C++ [over.built]p10: 3973 // For every promoted integral type T, there exist candidate 3974 // operator functions of the form 3975 // 3976 // T operator~(T); 3977 for (unsigned Int = FirstPromotedIntegralType; 3978 Int < LastPromotedIntegralType; ++Int) { 3979 QualType IntTy = ArithmeticTypes[Int]; 3980 AddBuiltinCandidate(IntTy, &IntTy, Args, 1, CandidateSet); 3981 } 3982 break; 3983 3984 case OO_New: 3985 case OO_Delete: 3986 case OO_Array_New: 3987 case OO_Array_Delete: 3988 case OO_Call: 3989 assert(false && "Special operators don't use AddBuiltinOperatorCandidates"); 3990 break; 3991 3992 case OO_Comma: 3993 UnaryAmp: 3994 case OO_Arrow: 3995 // C++ [over.match.oper]p3: 3996 // -- For the operator ',', the unary operator '&', or the 3997 // operator '->', the built-in candidates set is empty. 3998 break; 3999 4000 case OO_EqualEqual: 4001 case OO_ExclaimEqual: 4002 // C++ [over.match.oper]p16: 4003 // For every pointer to member type T, there exist candidate operator 4004 // functions of the form 4005 // 4006 // bool operator==(T,T); 4007 // bool operator!=(T,T); 4008 for (BuiltinCandidateTypeSet::iterator 4009 MemPtr = CandidateTypes.member_pointer_begin(), 4010 MemPtrEnd = CandidateTypes.member_pointer_end(); 4011 MemPtr != MemPtrEnd; 4012 ++MemPtr) { 4013 QualType ParamTypes[2] = { *MemPtr, *MemPtr }; 4014 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 4015 } 4016 4017 // Fall through 4018 4019 case OO_Less: 4020 case OO_Greater: 4021 case OO_LessEqual: 4022 case OO_GreaterEqual: 4023 // C++ [over.built]p15: 4024 // 4025 // For every pointer or enumeration type T, there exist 4026 // candidate operator functions of the form 4027 // 4028 // bool operator<(T, T); 4029 // bool operator>(T, T); 4030 // bool operator<=(T, T); 4031 // bool operator>=(T, T); 4032 // bool operator==(T, T); 4033 // bool operator!=(T, T); 4034 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 4035 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4036 QualType ParamTypes[2] = { *Ptr, *Ptr }; 4037 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 4038 } 4039 for (BuiltinCandidateTypeSet::iterator Enum 4040 = CandidateTypes.enumeration_begin(); 4041 Enum != CandidateTypes.enumeration_end(); ++Enum) { 4042 QualType ParamTypes[2] = { *Enum, *Enum }; 4043 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 4044 } 4045 4046 // Fall through. 4047 isComparison = true; 4048 4049 BinaryPlus: 4050 BinaryMinus: 4051 if (!isComparison) { 4052 // We didn't fall through, so we must have OO_Plus or OO_Minus. 4053 4054 // C++ [over.built]p13: 4055 // 4056 // For every cv-qualified or cv-unqualified object type T 4057 // there exist candidate operator functions of the form 4058 // 4059 // T* operator+(T*, ptrdiff_t); 4060 // T& operator[](T*, ptrdiff_t); [BELOW] 4061 // T* operator-(T*, ptrdiff_t); 4062 // T* operator+(ptrdiff_t, T*); 4063 // T& operator[](ptrdiff_t, T*); [BELOW] 4064 // 4065 // C++ [over.built]p14: 4066 // 4067 // For every T, where T is a pointer to object type, there 4068 // exist candidate operator functions of the form 4069 // 4070 // ptrdiff_t operator-(T, T); 4071 for (BuiltinCandidateTypeSet::iterator Ptr 4072 = CandidateTypes.pointer_begin(); 4073 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4074 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 4075 4076 // operator+(T*, ptrdiff_t) or operator-(T*, ptrdiff_t) 4077 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 4078 4079 if (Op == OO_Plus) { 4080 // T* operator+(ptrdiff_t, T*); 4081 ParamTypes[0] = ParamTypes[1]; 4082 ParamTypes[1] = *Ptr; 4083 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 4084 } else { 4085 // ptrdiff_t operator-(T, T); 4086 ParamTypes[1] = *Ptr; 4087 AddBuiltinCandidate(Context.getPointerDiffType(), ParamTypes, 4088 Args, 2, CandidateSet); 4089 } 4090 } 4091 } 4092 // Fall through 4093 4094 case OO_Slash: 4095 BinaryStar: 4096 Conditional: 4097 // C++ [over.built]p12: 4098 // 4099 // For every pair of promoted arithmetic types L and R, there 4100 // exist candidate operator functions of the form 4101 // 4102 // LR operator*(L, R); 4103 // LR operator/(L, R); 4104 // LR operator+(L, R); 4105 // LR operator-(L, R); 4106 // bool operator<(L, R); 4107 // bool operator>(L, R); 4108 // bool operator<=(L, R); 4109 // bool operator>=(L, R); 4110 // bool operator==(L, R); 4111 // bool operator!=(L, R); 4112 // 4113 // where LR is the result of the usual arithmetic conversions 4114 // between types L and R. 4115 // 4116 // C++ [over.built]p24: 4117 // 4118 // For every pair of promoted arithmetic types L and R, there exist 4119 // candidate operator functions of the form 4120 // 4121 // LR operator?(bool, L, R); 4122 // 4123 // where LR is the result of the usual arithmetic conversions 4124 // between types L and R. 4125 // Our candidates ignore the first parameter. 4126 for (unsigned Left = FirstPromotedArithmeticType; 4127 Left < LastPromotedArithmeticType; ++Left) { 4128 for (unsigned Right = FirstPromotedArithmeticType; 4129 Right < LastPromotedArithmeticType; ++Right) { 4130 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 4131 QualType Result 4132 = isComparison 4133 ? Context.BoolTy 4134 : Context.UsualArithmeticConversionsType(LandR[0], LandR[1]); 4135 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 4136 } 4137 } 4138 break; 4139 4140 case OO_Percent: 4141 BinaryAmp: 4142 case OO_Caret: 4143 case OO_Pipe: 4144 case OO_LessLess: 4145 case OO_GreaterGreater: 4146 // C++ [over.built]p17: 4147 // 4148 // For every pair of promoted integral types L and R, there 4149 // exist candidate operator functions of the form 4150 // 4151 // LR operator%(L, R); 4152 // LR operator&(L, R); 4153 // LR operator^(L, R); 4154 // LR operator|(L, R); 4155 // L operator<<(L, R); 4156 // L operator>>(L, R); 4157 // 4158 // where LR is the result of the usual arithmetic conversions 4159 // between types L and R. 4160 for (unsigned Left = FirstPromotedIntegralType; 4161 Left < LastPromotedIntegralType; ++Left) { 4162 for (unsigned Right = FirstPromotedIntegralType; 4163 Right < LastPromotedIntegralType; ++Right) { 4164 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 4165 QualType Result = (Op == OO_LessLess || Op == OO_GreaterGreater) 4166 ? LandR[0] 4167 : Context.UsualArithmeticConversionsType(LandR[0], LandR[1]); 4168 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 4169 } 4170 } 4171 break; 4172 4173 case OO_Equal: 4174 // C++ [over.built]p20: 4175 // 4176 // For every pair (T, VQ), where T is an enumeration or 4177 // pointer to member type and VQ is either volatile or 4178 // empty, there exist candidate operator functions of the form 4179 // 4180 // VQ T& operator=(VQ T&, T); 4181 for (BuiltinCandidateTypeSet::iterator 4182 Enum = CandidateTypes.enumeration_begin(), 4183 EnumEnd = CandidateTypes.enumeration_end(); 4184 Enum != EnumEnd; ++Enum) 4185 AddBuiltinAssignmentOperatorCandidates(*this, *Enum, Args, 2, 4186 CandidateSet); 4187 for (BuiltinCandidateTypeSet::iterator 4188 MemPtr = CandidateTypes.member_pointer_begin(), 4189 MemPtrEnd = CandidateTypes.member_pointer_end(); 4190 MemPtr != MemPtrEnd; ++MemPtr) 4191 AddBuiltinAssignmentOperatorCandidates(*this, *MemPtr, Args, 2, 4192 CandidateSet); 4193 // Fall through. 4194 4195 case OO_PlusEqual: 4196 case OO_MinusEqual: 4197 // C++ [over.built]p19: 4198 // 4199 // For every pair (T, VQ), where T is any type and VQ is either 4200 // volatile or empty, there exist candidate operator functions 4201 // of the form 4202 // 4203 // T*VQ& operator=(T*VQ&, T*); 4204 // 4205 // C++ [over.built]p21: 4206 // 4207 // For every pair (T, VQ), where T is a cv-qualified or 4208 // cv-unqualified object type and VQ is either volatile or 4209 // empty, there exist candidate operator functions of the form 4210 // 4211 // T*VQ& operator+=(T*VQ&, ptrdiff_t); 4212 // T*VQ& operator-=(T*VQ&, ptrdiff_t); 4213 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 4214 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4215 QualType ParamTypes[2]; 4216 ParamTypes[1] = (Op == OO_Equal)? *Ptr : Context.getPointerDiffType(); 4217 4218 // non-volatile version 4219 ParamTypes[0] = Context.getLValueReferenceType(*Ptr); 4220 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4221 /*IsAssigmentOperator=*/Op == OO_Equal); 4222 4223 if (!Context.getCanonicalType(*Ptr).isVolatileQualified() && 4224 VisibleTypeConversionsQuals.hasVolatile()) { 4225 // volatile version 4226 ParamTypes[0] 4227 = Context.getLValueReferenceType(Context.getVolatileType(*Ptr)); 4228 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4229 /*IsAssigmentOperator=*/Op == OO_Equal); 4230 } 4231 } 4232 // Fall through. 4233 4234 case OO_StarEqual: 4235 case OO_SlashEqual: 4236 // C++ [over.built]p18: 4237 // 4238 // For every triple (L, VQ, R), where L is an arithmetic type, 4239 // VQ is either volatile or empty, and R is a promoted 4240 // arithmetic type, there exist candidate operator functions of 4241 // the form 4242 // 4243 // VQ L& operator=(VQ L&, R); 4244 // VQ L& operator*=(VQ L&, R); 4245 // VQ L& operator/=(VQ L&, R); 4246 // VQ L& operator+=(VQ L&, R); 4247 // VQ L& operator-=(VQ L&, R); 4248 for (unsigned Left = 0; Left < NumArithmeticTypes; ++Left) { 4249 for (unsigned Right = FirstPromotedArithmeticType; 4250 Right < LastPromotedArithmeticType; ++Right) { 4251 QualType ParamTypes[2]; 4252 ParamTypes[1] = ArithmeticTypes[Right]; 4253 4254 // Add this built-in operator as a candidate (VQ is empty). 4255 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 4256 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4257 /*IsAssigmentOperator=*/Op == OO_Equal); 4258 4259 // Add this built-in operator as a candidate (VQ is 'volatile'). 4260 if (VisibleTypeConversionsQuals.hasVolatile()) { 4261 ParamTypes[0] = Context.getVolatileType(ArithmeticTypes[Left]); 4262 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 4263 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4264 /*IsAssigmentOperator=*/Op == OO_Equal); 4265 } 4266 } 4267 } 4268 break; 4269 4270 case OO_PercentEqual: 4271 case OO_LessLessEqual: 4272 case OO_GreaterGreaterEqual: 4273 case OO_AmpEqual: 4274 case OO_CaretEqual: 4275 case OO_PipeEqual: 4276 // C++ [over.built]p22: 4277 // 4278 // For every triple (L, VQ, R), where L is an integral type, VQ 4279 // is either volatile or empty, and R is a promoted integral 4280 // type, there exist candidate operator functions of the form 4281 // 4282 // VQ L& operator%=(VQ L&, R); 4283 // VQ L& operator<<=(VQ L&, R); 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 for (unsigned Left = FirstIntegralType; Left < LastIntegralType; ++Left) { 4289 for (unsigned Right = FirstPromotedIntegralType; 4290 Right < LastPromotedIntegralType; ++Right) { 4291 QualType ParamTypes[2]; 4292 ParamTypes[1] = ArithmeticTypes[Right]; 4293 4294 // Add this built-in operator as a candidate (VQ is empty). 4295 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 4296 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 4297 if (VisibleTypeConversionsQuals.hasVolatile()) { 4298 // Add this built-in operator as a candidate (VQ is 'volatile'). 4299 ParamTypes[0] = ArithmeticTypes[Left]; 4300 ParamTypes[0] = Context.getVolatileType(ParamTypes[0]); 4301 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 4302 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 4303 } 4304 } 4305 } 4306 break; 4307 4308 case OO_Exclaim: { 4309 // C++ [over.operator]p23: 4310 // 4311 // There also exist candidate operator functions of the form 4312 // 4313 // bool operator!(bool); 4314 // bool operator&&(bool, bool); [BELOW] 4315 // bool operator||(bool, bool); [BELOW] 4316 QualType ParamTy = Context.BoolTy; 4317 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet, 4318 /*IsAssignmentOperator=*/false, 4319 /*NumContextualBoolArguments=*/1); 4320 break; 4321 } 4322 4323 case OO_AmpAmp: 4324 case OO_PipePipe: { 4325 // C++ [over.operator]p23: 4326 // 4327 // There also exist candidate operator functions of the form 4328 // 4329 // bool operator!(bool); [ABOVE] 4330 // bool operator&&(bool, bool); 4331 // bool operator||(bool, bool); 4332 QualType ParamTypes[2] = { Context.BoolTy, Context.BoolTy }; 4333 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet, 4334 /*IsAssignmentOperator=*/false, 4335 /*NumContextualBoolArguments=*/2); 4336 break; 4337 } 4338 4339 case OO_Subscript: 4340 // C++ [over.built]p13: 4341 // 4342 // For every cv-qualified or cv-unqualified object type T there 4343 // exist candidate operator functions of the form 4344 // 4345 // T* operator+(T*, ptrdiff_t); [ABOVE] 4346 // T& operator[](T*, ptrdiff_t); 4347 // T* operator-(T*, ptrdiff_t); [ABOVE] 4348 // T* operator+(ptrdiff_t, T*); [ABOVE] 4349 // T& operator[](ptrdiff_t, T*); 4350 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 4351 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4352 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 4353 QualType PointeeType = (*Ptr)->getAs<PointerType>()->getPointeeType(); 4354 QualType ResultTy = Context.getLValueReferenceType(PointeeType); 4355 4356 // T& operator[](T*, ptrdiff_t) 4357 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 4358 4359 // T& operator[](ptrdiff_t, T*); 4360 ParamTypes[0] = ParamTypes[1]; 4361 ParamTypes[1] = *Ptr; 4362 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 4363 } 4364 break; 4365 4366 case OO_ArrowStar: 4367 // C++ [over.built]p11: 4368 // For every quintuple (C1, C2, T, CV1, CV2), where C2 is a class type, 4369 // C1 is the same type as C2 or is a derived class of C2, T is an object 4370 // type or a function type, and CV1 and CV2 are cv-qualifier-seqs, 4371 // there exist candidate operator functions of the form 4372 // CV12 T& operator->*(CV1 C1*, CV2 T C2::*); 4373 // where CV12 is the union of CV1 and CV2. 4374 { 4375 for (BuiltinCandidateTypeSet::iterator Ptr = 4376 CandidateTypes.pointer_begin(); 4377 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4378 QualType C1Ty = (*Ptr); 4379 QualType C1; 4380 QualifierCollector Q1; 4381 if (const PointerType *PointerTy = C1Ty->getAs<PointerType>()) { 4382 C1 = QualType(Q1.strip(PointerTy->getPointeeType()), 0); 4383 if (!isa<RecordType>(C1)) 4384 continue; 4385 // heuristic to reduce number of builtin candidates in the set. 4386 // Add volatile/restrict version only if there are conversions to a 4387 // volatile/restrict type. 4388 if (!VisibleTypeConversionsQuals.hasVolatile() && Q1.hasVolatile()) 4389 continue; 4390 if (!VisibleTypeConversionsQuals.hasRestrict() && Q1.hasRestrict()) 4391 continue; 4392 } 4393 for (BuiltinCandidateTypeSet::iterator 4394 MemPtr = CandidateTypes.member_pointer_begin(), 4395 MemPtrEnd = CandidateTypes.member_pointer_end(); 4396 MemPtr != MemPtrEnd; ++MemPtr) { 4397 const MemberPointerType *mptr = cast<MemberPointerType>(*MemPtr); 4398 QualType C2 = QualType(mptr->getClass(), 0); 4399 C2 = C2.getUnqualifiedType(); 4400 if (C1 != C2 && !IsDerivedFrom(C1, C2)) 4401 break; 4402 QualType ParamTypes[2] = { *Ptr, *MemPtr }; 4403 // build CV12 T& 4404 QualType T = mptr->getPointeeType(); 4405 if (!VisibleTypeConversionsQuals.hasVolatile() && 4406 T.isVolatileQualified()) 4407 continue; 4408 if (!VisibleTypeConversionsQuals.hasRestrict() && 4409 T.isRestrictQualified()) 4410 continue; 4411 T = Q1.apply(T); 4412 QualType ResultTy = Context.getLValueReferenceType(T); 4413 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 4414 } 4415 } 4416 } 4417 break; 4418 4419 case OO_Conditional: 4420 // Note that we don't consider the first argument, since it has been 4421 // contextually converted to bool long ago. The candidates below are 4422 // therefore added as binary. 4423 // 4424 // C++ [over.built]p24: 4425 // For every type T, where T is a pointer or pointer-to-member type, 4426 // there exist candidate operator functions of the form 4427 // 4428 // T operator?(bool, T, T); 4429 // 4430 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(), 4431 E = CandidateTypes.pointer_end(); Ptr != E; ++Ptr) { 4432 QualType ParamTypes[2] = { *Ptr, *Ptr }; 4433 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 4434 } 4435 for (BuiltinCandidateTypeSet::iterator Ptr = 4436 CandidateTypes.member_pointer_begin(), 4437 E = CandidateTypes.member_pointer_end(); Ptr != E; ++Ptr) { 4438 QualType ParamTypes[2] = { *Ptr, *Ptr }; 4439 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 4440 } 4441 goto Conditional; 4442 } 4443} 4444 4445/// \brief Add function candidates found via argument-dependent lookup 4446/// to the set of overloading candidates. 4447/// 4448/// This routine performs argument-dependent name lookup based on the 4449/// given function name (which may also be an operator name) and adds 4450/// all of the overload candidates found by ADL to the overload 4451/// candidate set (C++ [basic.lookup.argdep]). 4452void 4453Sema::AddArgumentDependentLookupCandidates(DeclarationName Name, 4454 bool Operator, 4455 Expr **Args, unsigned NumArgs, 4456 const TemplateArgumentListInfo *ExplicitTemplateArgs, 4457 OverloadCandidateSet& CandidateSet, 4458 bool PartialOverloading) { 4459 ADLResult Fns; 4460 4461 // FIXME: This approach for uniquing ADL results (and removing 4462 // redundant candidates from the set) relies on pointer-equality, 4463 // which means we need to key off the canonical decl. However, 4464 // always going back to the canonical decl might not get us the 4465 // right set of default arguments. What default arguments are 4466 // we supposed to consider on ADL candidates, anyway? 4467 4468 // FIXME: Pass in the explicit template arguments? 4469 ArgumentDependentLookup(Name, Operator, Args, NumArgs, Fns); 4470 4471 // Erase all of the candidates we already knew about. 4472 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 4473 CandEnd = CandidateSet.end(); 4474 Cand != CandEnd; ++Cand) 4475 if (Cand->Function) { 4476 Fns.erase(Cand->Function); 4477 if (FunctionTemplateDecl *FunTmpl = Cand->Function->getPrimaryTemplate()) 4478 Fns.erase(FunTmpl); 4479 } 4480 4481 // For each of the ADL candidates we found, add it to the overload 4482 // set. 4483 for (ADLResult::iterator I = Fns.begin(), E = Fns.end(); I != E; ++I) { 4484 DeclAccessPair FoundDecl = DeclAccessPair::make(*I, AS_none); 4485 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*I)) { 4486 if (ExplicitTemplateArgs) 4487 continue; 4488 4489 AddOverloadCandidate(FD, FoundDecl, Args, NumArgs, CandidateSet, 4490 false, false, PartialOverloading); 4491 } else 4492 AddTemplateOverloadCandidate(cast<FunctionTemplateDecl>(*I), 4493 FoundDecl, ExplicitTemplateArgs, 4494 Args, NumArgs, CandidateSet); 4495 } 4496} 4497 4498/// isBetterOverloadCandidate - Determines whether the first overload 4499/// candidate is a better candidate than the second (C++ 13.3.3p1). 4500bool 4501Sema::isBetterOverloadCandidate(const OverloadCandidate& Cand1, 4502 const OverloadCandidate& Cand2, 4503 SourceLocation Loc) { 4504 // Define viable functions to be better candidates than non-viable 4505 // functions. 4506 if (!Cand2.Viable) 4507 return Cand1.Viable; 4508 else if (!Cand1.Viable) 4509 return false; 4510 4511 // C++ [over.match.best]p1: 4512 // 4513 // -- if F is a static member function, ICS1(F) is defined such 4514 // that ICS1(F) is neither better nor worse than ICS1(G) for 4515 // any function G, and, symmetrically, ICS1(G) is neither 4516 // better nor worse than ICS1(F). 4517 unsigned StartArg = 0; 4518 if (Cand1.IgnoreObjectArgument || Cand2.IgnoreObjectArgument) 4519 StartArg = 1; 4520 4521 // C++ [over.match.best]p1: 4522 // A viable function F1 is defined to be a better function than another 4523 // viable function F2 if for all arguments i, ICSi(F1) is not a worse 4524 // conversion sequence than ICSi(F2), and then... 4525 unsigned NumArgs = Cand1.Conversions.size(); 4526 assert(Cand2.Conversions.size() == NumArgs && "Overload candidate mismatch"); 4527 bool HasBetterConversion = false; 4528 for (unsigned ArgIdx = StartArg; ArgIdx < NumArgs; ++ArgIdx) { 4529 switch (CompareImplicitConversionSequences(Cand1.Conversions[ArgIdx], 4530 Cand2.Conversions[ArgIdx])) { 4531 case ImplicitConversionSequence::Better: 4532 // Cand1 has a better conversion sequence. 4533 HasBetterConversion = true; 4534 break; 4535 4536 case ImplicitConversionSequence::Worse: 4537 // Cand1 can't be better than Cand2. 4538 return false; 4539 4540 case ImplicitConversionSequence::Indistinguishable: 4541 // Do nothing. 4542 break; 4543 } 4544 } 4545 4546 // -- for some argument j, ICSj(F1) is a better conversion sequence than 4547 // ICSj(F2), or, if not that, 4548 if (HasBetterConversion) 4549 return true; 4550 4551 // - F1 is a non-template function and F2 is a function template 4552 // specialization, or, if not that, 4553 if (Cand1.Function && !Cand1.Function->getPrimaryTemplate() && 4554 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 4555 return true; 4556 4557 // -- F1 and F2 are function template specializations, and the function 4558 // template for F1 is more specialized than the template for F2 4559 // according to the partial ordering rules described in 14.5.5.2, or, 4560 // if not that, 4561 if (Cand1.Function && Cand1.Function->getPrimaryTemplate() && 4562 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 4563 if (FunctionTemplateDecl *BetterTemplate 4564 = getMoreSpecializedTemplate(Cand1.Function->getPrimaryTemplate(), 4565 Cand2.Function->getPrimaryTemplate(), 4566 Loc, 4567 isa<CXXConversionDecl>(Cand1.Function)? TPOC_Conversion 4568 : TPOC_Call)) 4569 return BetterTemplate == Cand1.Function->getPrimaryTemplate(); 4570 4571 // -- the context is an initialization by user-defined conversion 4572 // (see 8.5, 13.3.1.5) and the standard conversion sequence 4573 // from the return type of F1 to the destination type (i.e., 4574 // the type of the entity being initialized) is a better 4575 // conversion sequence than the standard conversion sequence 4576 // from the return type of F2 to the destination type. 4577 if (Cand1.Function && Cand2.Function && 4578 isa<CXXConversionDecl>(Cand1.Function) && 4579 isa<CXXConversionDecl>(Cand2.Function)) { 4580 switch (CompareStandardConversionSequences(Cand1.FinalConversion, 4581 Cand2.FinalConversion)) { 4582 case ImplicitConversionSequence::Better: 4583 // Cand1 has a better conversion sequence. 4584 return true; 4585 4586 case ImplicitConversionSequence::Worse: 4587 // Cand1 can't be better than Cand2. 4588 return false; 4589 4590 case ImplicitConversionSequence::Indistinguishable: 4591 // Do nothing 4592 break; 4593 } 4594 } 4595 4596 return false; 4597} 4598 4599/// \brief Computes the best viable function (C++ 13.3.3) 4600/// within an overload candidate set. 4601/// 4602/// \param CandidateSet the set of candidate functions. 4603/// 4604/// \param Loc the location of the function name (or operator symbol) for 4605/// which overload resolution occurs. 4606/// 4607/// \param Best f overload resolution was successful or found a deleted 4608/// function, Best points to the candidate function found. 4609/// 4610/// \returns The result of overload resolution. 4611OverloadingResult Sema::BestViableFunction(OverloadCandidateSet& CandidateSet, 4612 SourceLocation Loc, 4613 OverloadCandidateSet::iterator& Best) { 4614 // Find the best viable function. 4615 Best = CandidateSet.end(); 4616 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 4617 Cand != CandidateSet.end(); ++Cand) { 4618 if (Cand->Viable) { 4619 if (Best == CandidateSet.end() || 4620 isBetterOverloadCandidate(*Cand, *Best, Loc)) 4621 Best = Cand; 4622 } 4623 } 4624 4625 // If we didn't find any viable functions, abort. 4626 if (Best == CandidateSet.end()) 4627 return OR_No_Viable_Function; 4628 4629 // Make sure that this function is better than every other viable 4630 // function. If not, we have an ambiguity. 4631 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 4632 Cand != CandidateSet.end(); ++Cand) { 4633 if (Cand->Viable && 4634 Cand != Best && 4635 !isBetterOverloadCandidate(*Best, *Cand, Loc)) { 4636 Best = CandidateSet.end(); 4637 return OR_Ambiguous; 4638 } 4639 } 4640 4641 // Best is the best viable function. 4642 if (Best->Function && 4643 (Best->Function->isDeleted() || 4644 Best->Function->getAttr<UnavailableAttr>())) 4645 return OR_Deleted; 4646 4647 // C++ [basic.def.odr]p2: 4648 // An overloaded function is used if it is selected by overload resolution 4649 // when referred to from a potentially-evaluated expression. [Note: this 4650 // covers calls to named functions (5.2.2), operator overloading 4651 // (clause 13), user-defined conversions (12.3.2), allocation function for 4652 // placement new (5.3.4), as well as non-default initialization (8.5). 4653 if (Best->Function) 4654 MarkDeclarationReferenced(Loc, Best->Function); 4655 return OR_Success; 4656} 4657 4658namespace { 4659 4660enum OverloadCandidateKind { 4661 oc_function, 4662 oc_method, 4663 oc_constructor, 4664 oc_function_template, 4665 oc_method_template, 4666 oc_constructor_template, 4667 oc_implicit_default_constructor, 4668 oc_implicit_copy_constructor, 4669 oc_implicit_copy_assignment 4670}; 4671 4672OverloadCandidateKind ClassifyOverloadCandidate(Sema &S, 4673 FunctionDecl *Fn, 4674 std::string &Description) { 4675 bool isTemplate = false; 4676 4677 if (FunctionTemplateDecl *FunTmpl = Fn->getPrimaryTemplate()) { 4678 isTemplate = true; 4679 Description = S.getTemplateArgumentBindingsText( 4680 FunTmpl->getTemplateParameters(), *Fn->getTemplateSpecializationArgs()); 4681 } 4682 4683 if (CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(Fn)) { 4684 if (!Ctor->isImplicit()) 4685 return isTemplate ? oc_constructor_template : oc_constructor; 4686 4687 return Ctor->isCopyConstructor() ? oc_implicit_copy_constructor 4688 : oc_implicit_default_constructor; 4689 } 4690 4691 if (CXXMethodDecl *Meth = dyn_cast<CXXMethodDecl>(Fn)) { 4692 // This actually gets spelled 'candidate function' for now, but 4693 // it doesn't hurt to split it out. 4694 if (!Meth->isImplicit()) 4695 return isTemplate ? oc_method_template : oc_method; 4696 4697 assert(Meth->isCopyAssignment() 4698 && "implicit method is not copy assignment operator?"); 4699 return oc_implicit_copy_assignment; 4700 } 4701 4702 return isTemplate ? oc_function_template : oc_function; 4703} 4704 4705} // end anonymous namespace 4706 4707// Notes the location of an overload candidate. 4708void Sema::NoteOverloadCandidate(FunctionDecl *Fn) { 4709 std::string FnDesc; 4710 OverloadCandidateKind K = ClassifyOverloadCandidate(*this, Fn, FnDesc); 4711 Diag(Fn->getLocation(), diag::note_ovl_candidate) 4712 << (unsigned) K << FnDesc; 4713} 4714 4715/// Diagnoses an ambiguous conversion. The partial diagnostic is the 4716/// "lead" diagnostic; it will be given two arguments, the source and 4717/// target types of the conversion. 4718void Sema::DiagnoseAmbiguousConversion(const ImplicitConversionSequence &ICS, 4719 SourceLocation CaretLoc, 4720 const PartialDiagnostic &PDiag) { 4721 Diag(CaretLoc, PDiag) 4722 << ICS.Ambiguous.getFromType() << ICS.Ambiguous.getToType(); 4723 for (AmbiguousConversionSequence::const_iterator 4724 I = ICS.Ambiguous.begin(), E = ICS.Ambiguous.end(); I != E; ++I) { 4725 NoteOverloadCandidate(*I); 4726 } 4727} 4728 4729namespace { 4730 4731void DiagnoseBadConversion(Sema &S, OverloadCandidate *Cand, unsigned I) { 4732 const ImplicitConversionSequence &Conv = Cand->Conversions[I]; 4733 assert(Conv.isBad()); 4734 assert(Cand->Function && "for now, candidate must be a function"); 4735 FunctionDecl *Fn = Cand->Function; 4736 4737 // There's a conversion slot for the object argument if this is a 4738 // non-constructor method. Note that 'I' corresponds the 4739 // conversion-slot index. 4740 bool isObjectArgument = false; 4741 if (isa<CXXMethodDecl>(Fn) && !isa<CXXConstructorDecl>(Fn)) { 4742 if (I == 0) 4743 isObjectArgument = true; 4744 else 4745 I--; 4746 } 4747 4748 std::string FnDesc; 4749 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, FnDesc); 4750 4751 Expr *FromExpr = Conv.Bad.FromExpr; 4752 QualType FromTy = Conv.Bad.getFromType(); 4753 QualType ToTy = Conv.Bad.getToType(); 4754 4755 if (FromTy == S.Context.OverloadTy) { 4756 assert(FromExpr && "overload set argument came from implicit argument?"); 4757 Expr *E = FromExpr->IgnoreParens(); 4758 if (isa<UnaryOperator>(E)) 4759 E = cast<UnaryOperator>(E)->getSubExpr()->IgnoreParens(); 4760 DeclarationName Name = cast<OverloadExpr>(E)->getName(); 4761 4762 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_overload) 4763 << (unsigned) FnKind << FnDesc 4764 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 4765 << ToTy << Name << I+1; 4766 return; 4767 } 4768 4769 // Do some hand-waving analysis to see if the non-viability is due 4770 // to a qualifier mismatch. 4771 CanQualType CFromTy = S.Context.getCanonicalType(FromTy); 4772 CanQualType CToTy = S.Context.getCanonicalType(ToTy); 4773 if (CanQual<ReferenceType> RT = CToTy->getAs<ReferenceType>()) 4774 CToTy = RT->getPointeeType(); 4775 else { 4776 // TODO: detect and diagnose the full richness of const mismatches. 4777 if (CanQual<PointerType> FromPT = CFromTy->getAs<PointerType>()) 4778 if (CanQual<PointerType> ToPT = CToTy->getAs<PointerType>()) 4779 CFromTy = FromPT->getPointeeType(), CToTy = ToPT->getPointeeType(); 4780 } 4781 4782 if (CToTy.getUnqualifiedType() == CFromTy.getUnqualifiedType() && 4783 !CToTy.isAtLeastAsQualifiedAs(CFromTy)) { 4784 // It is dumb that we have to do this here. 4785 while (isa<ArrayType>(CFromTy)) 4786 CFromTy = CFromTy->getAs<ArrayType>()->getElementType(); 4787 while (isa<ArrayType>(CToTy)) 4788 CToTy = CFromTy->getAs<ArrayType>()->getElementType(); 4789 4790 Qualifiers FromQs = CFromTy.getQualifiers(); 4791 Qualifiers ToQs = CToTy.getQualifiers(); 4792 4793 if (FromQs.getAddressSpace() != ToQs.getAddressSpace()) { 4794 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_addrspace) 4795 << (unsigned) FnKind << FnDesc 4796 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 4797 << FromTy 4798 << FromQs.getAddressSpace() << ToQs.getAddressSpace() 4799 << (unsigned) isObjectArgument << I+1; 4800 return; 4801 } 4802 4803 unsigned CVR = FromQs.getCVRQualifiers() & ~ToQs.getCVRQualifiers(); 4804 assert(CVR && "unexpected qualifiers mismatch"); 4805 4806 if (isObjectArgument) { 4807 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr_this) 4808 << (unsigned) FnKind << FnDesc 4809 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 4810 << FromTy << (CVR - 1); 4811 } else { 4812 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr) 4813 << (unsigned) FnKind << FnDesc 4814 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 4815 << FromTy << (CVR - 1) << I+1; 4816 } 4817 return; 4818 } 4819 4820 // Diagnose references or pointers to incomplete types differently, 4821 // since it's far from impossible that the incompleteness triggered 4822 // the failure. 4823 QualType TempFromTy = FromTy.getNonReferenceType(); 4824 if (const PointerType *PTy = TempFromTy->getAs<PointerType>()) 4825 TempFromTy = PTy->getPointeeType(); 4826 if (TempFromTy->isIncompleteType()) { 4827 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_conv_incomplete) 4828 << (unsigned) FnKind << FnDesc 4829 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 4830 << FromTy << ToTy << (unsigned) isObjectArgument << I+1; 4831 return; 4832 } 4833 4834 // TODO: specialize more based on the kind of mismatch 4835 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_conv) 4836 << (unsigned) FnKind << FnDesc 4837 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 4838 << FromTy << ToTy << (unsigned) isObjectArgument << I+1; 4839} 4840 4841void DiagnoseArityMismatch(Sema &S, OverloadCandidate *Cand, 4842 unsigned NumFormalArgs) { 4843 // TODO: treat calls to a missing default constructor as a special case 4844 4845 FunctionDecl *Fn = Cand->Function; 4846 const FunctionProtoType *FnTy = Fn->getType()->getAs<FunctionProtoType>(); 4847 4848 unsigned MinParams = Fn->getMinRequiredArguments(); 4849 4850 // at least / at most / exactly 4851 unsigned mode, modeCount; 4852 if (NumFormalArgs < MinParams) { 4853 assert(Cand->FailureKind == ovl_fail_too_few_arguments); 4854 if (MinParams != FnTy->getNumArgs() || FnTy->isVariadic()) 4855 mode = 0; // "at least" 4856 else 4857 mode = 2; // "exactly" 4858 modeCount = MinParams; 4859 } else { 4860 assert(Cand->FailureKind == ovl_fail_too_many_arguments); 4861 if (MinParams != FnTy->getNumArgs()) 4862 mode = 1; // "at most" 4863 else 4864 mode = 2; // "exactly" 4865 modeCount = FnTy->getNumArgs(); 4866 } 4867 4868 std::string Description; 4869 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, Description); 4870 4871 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_arity) 4872 << (unsigned) FnKind << Description << mode << modeCount << NumFormalArgs; 4873} 4874 4875/// Diagnose a failed template-argument deduction. 4876void DiagnoseBadDeduction(Sema &S, OverloadCandidate *Cand, 4877 Expr **Args, unsigned NumArgs) { 4878 FunctionDecl *Fn = Cand->Function; // pattern 4879 4880 TemplateParameter Param = TemplateParameter::getFromOpaqueValue( 4881 Cand->DeductionFailure.TemplateParameter); 4882 4883 switch (Cand->DeductionFailure.Result) { 4884 case Sema::TDK_Success: 4885 llvm_unreachable("TDK_success while diagnosing bad deduction"); 4886 4887 case Sema::TDK_Incomplete: { 4888 NamedDecl *ParamD; 4889 (ParamD = Param.dyn_cast<TemplateTypeParmDecl*>()) || 4890 (ParamD = Param.dyn_cast<NonTypeTemplateParmDecl*>()) || 4891 (ParamD = Param.dyn_cast<TemplateTemplateParmDecl*>()); 4892 assert(ParamD && "no parameter found for incomplete deduction result"); 4893 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_incomplete_deduction) 4894 << ParamD->getDeclName(); 4895 return; 4896 } 4897 4898 // TODO: diagnose these individually, then kill off 4899 // note_ovl_candidate_bad_deduction, which is uselessly vague. 4900 case Sema::TDK_InstantiationDepth: 4901 case Sema::TDK_Inconsistent: 4902 case Sema::TDK_InconsistentQuals: 4903 case Sema::TDK_SubstitutionFailure: 4904 case Sema::TDK_NonDeducedMismatch: 4905 case Sema::TDK_TooManyArguments: 4906 case Sema::TDK_TooFewArguments: 4907 case Sema::TDK_InvalidExplicitArguments: 4908 case Sema::TDK_FailedOverloadResolution: 4909 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_deduction); 4910 return; 4911 } 4912} 4913 4914/// Generates a 'note' diagnostic for an overload candidate. We've 4915/// already generated a primary error at the call site. 4916/// 4917/// It really does need to be a single diagnostic with its caret 4918/// pointed at the candidate declaration. Yes, this creates some 4919/// major challenges of technical writing. Yes, this makes pointing 4920/// out problems with specific arguments quite awkward. It's still 4921/// better than generating twenty screens of text for every failed 4922/// overload. 4923/// 4924/// It would be great to be able to express per-candidate problems 4925/// more richly for those diagnostic clients that cared, but we'd 4926/// still have to be just as careful with the default diagnostics. 4927void NoteFunctionCandidate(Sema &S, OverloadCandidate *Cand, 4928 Expr **Args, unsigned NumArgs) { 4929 FunctionDecl *Fn = Cand->Function; 4930 4931 // Note deleted candidates, but only if they're viable. 4932 if (Cand->Viable && (Fn->isDeleted() || Fn->hasAttr<UnavailableAttr>())) { 4933 std::string FnDesc; 4934 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, FnDesc); 4935 4936 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_deleted) 4937 << FnKind << FnDesc << Fn->isDeleted(); 4938 return; 4939 } 4940 4941 // We don't really have anything else to say about viable candidates. 4942 if (Cand->Viable) { 4943 S.NoteOverloadCandidate(Fn); 4944 return; 4945 } 4946 4947 switch (Cand->FailureKind) { 4948 case ovl_fail_too_many_arguments: 4949 case ovl_fail_too_few_arguments: 4950 return DiagnoseArityMismatch(S, Cand, NumArgs); 4951 4952 case ovl_fail_bad_deduction: 4953 return DiagnoseBadDeduction(S, Cand, Args, NumArgs); 4954 4955 case ovl_fail_trivial_conversion: 4956 case ovl_fail_bad_final_conversion: 4957 case ovl_fail_final_conversion_not_exact: 4958 return S.NoteOverloadCandidate(Fn); 4959 4960 case ovl_fail_bad_conversion: { 4961 unsigned I = (Cand->IgnoreObjectArgument ? 1 : 0); 4962 for (unsigned N = Cand->Conversions.size(); I != N; ++I) 4963 if (Cand->Conversions[I].isBad()) 4964 return DiagnoseBadConversion(S, Cand, I); 4965 4966 // FIXME: this currently happens when we're called from SemaInit 4967 // when user-conversion overload fails. Figure out how to handle 4968 // those conditions and diagnose them well. 4969 return S.NoteOverloadCandidate(Fn); 4970 } 4971 } 4972} 4973 4974void NoteSurrogateCandidate(Sema &S, OverloadCandidate *Cand) { 4975 // Desugar the type of the surrogate down to a function type, 4976 // retaining as many typedefs as possible while still showing 4977 // the function type (and, therefore, its parameter types). 4978 QualType FnType = Cand->Surrogate->getConversionType(); 4979 bool isLValueReference = false; 4980 bool isRValueReference = false; 4981 bool isPointer = false; 4982 if (const LValueReferenceType *FnTypeRef = 4983 FnType->getAs<LValueReferenceType>()) { 4984 FnType = FnTypeRef->getPointeeType(); 4985 isLValueReference = true; 4986 } else if (const RValueReferenceType *FnTypeRef = 4987 FnType->getAs<RValueReferenceType>()) { 4988 FnType = FnTypeRef->getPointeeType(); 4989 isRValueReference = true; 4990 } 4991 if (const PointerType *FnTypePtr = FnType->getAs<PointerType>()) { 4992 FnType = FnTypePtr->getPointeeType(); 4993 isPointer = true; 4994 } 4995 // Desugar down to a function type. 4996 FnType = QualType(FnType->getAs<FunctionType>(), 0); 4997 // Reconstruct the pointer/reference as appropriate. 4998 if (isPointer) FnType = S.Context.getPointerType(FnType); 4999 if (isRValueReference) FnType = S.Context.getRValueReferenceType(FnType); 5000 if (isLValueReference) FnType = S.Context.getLValueReferenceType(FnType); 5001 5002 S.Diag(Cand->Surrogate->getLocation(), diag::note_ovl_surrogate_cand) 5003 << FnType; 5004} 5005 5006void NoteBuiltinOperatorCandidate(Sema &S, 5007 const char *Opc, 5008 SourceLocation OpLoc, 5009 OverloadCandidate *Cand) { 5010 assert(Cand->Conversions.size() <= 2 && "builtin operator is not binary"); 5011 std::string TypeStr("operator"); 5012 TypeStr += Opc; 5013 TypeStr += "("; 5014 TypeStr += Cand->BuiltinTypes.ParamTypes[0].getAsString(); 5015 if (Cand->Conversions.size() == 1) { 5016 TypeStr += ")"; 5017 S.Diag(OpLoc, diag::note_ovl_builtin_unary_candidate) << TypeStr; 5018 } else { 5019 TypeStr += ", "; 5020 TypeStr += Cand->BuiltinTypes.ParamTypes[1].getAsString(); 5021 TypeStr += ")"; 5022 S.Diag(OpLoc, diag::note_ovl_builtin_binary_candidate) << TypeStr; 5023 } 5024} 5025 5026void NoteAmbiguousUserConversions(Sema &S, SourceLocation OpLoc, 5027 OverloadCandidate *Cand) { 5028 unsigned NoOperands = Cand->Conversions.size(); 5029 for (unsigned ArgIdx = 0; ArgIdx < NoOperands; ++ArgIdx) { 5030 const ImplicitConversionSequence &ICS = Cand->Conversions[ArgIdx]; 5031 if (ICS.isBad()) break; // all meaningless after first invalid 5032 if (!ICS.isAmbiguous()) continue; 5033 5034 S.DiagnoseAmbiguousConversion(ICS, OpLoc, 5035 S.PDiag(diag::note_ambiguous_type_conversion)); 5036 } 5037} 5038 5039SourceLocation GetLocationForCandidate(const OverloadCandidate *Cand) { 5040 if (Cand->Function) 5041 return Cand->Function->getLocation(); 5042 if (Cand->IsSurrogate) 5043 return Cand->Surrogate->getLocation(); 5044 return SourceLocation(); 5045} 5046 5047struct CompareOverloadCandidatesForDisplay { 5048 Sema &S; 5049 CompareOverloadCandidatesForDisplay(Sema &S) : S(S) {} 5050 5051 bool operator()(const OverloadCandidate *L, 5052 const OverloadCandidate *R) { 5053 // Fast-path this check. 5054 if (L == R) return false; 5055 5056 // Order first by viability. 5057 if (L->Viable) { 5058 if (!R->Viable) return true; 5059 5060 // TODO: introduce a tri-valued comparison for overload 5061 // candidates. Would be more worthwhile if we had a sort 5062 // that could exploit it. 5063 if (S.isBetterOverloadCandidate(*L, *R, SourceLocation())) return true; 5064 if (S.isBetterOverloadCandidate(*R, *L, SourceLocation())) return false; 5065 } else if (R->Viable) 5066 return false; 5067 5068 assert(L->Viable == R->Viable); 5069 5070 // Criteria by which we can sort non-viable candidates: 5071 if (!L->Viable) { 5072 // 1. Arity mismatches come after other candidates. 5073 if (L->FailureKind == ovl_fail_too_many_arguments || 5074 L->FailureKind == ovl_fail_too_few_arguments) 5075 return false; 5076 if (R->FailureKind == ovl_fail_too_many_arguments || 5077 R->FailureKind == ovl_fail_too_few_arguments) 5078 return true; 5079 5080 // 2. Bad conversions come first and are ordered by the number 5081 // of bad conversions and quality of good conversions. 5082 if (L->FailureKind == ovl_fail_bad_conversion) { 5083 if (R->FailureKind != ovl_fail_bad_conversion) 5084 return true; 5085 5086 // If there's any ordering between the defined conversions... 5087 // FIXME: this might not be transitive. 5088 assert(L->Conversions.size() == R->Conversions.size()); 5089 5090 int leftBetter = 0; 5091 unsigned I = (L->IgnoreObjectArgument || R->IgnoreObjectArgument); 5092 for (unsigned E = L->Conversions.size(); I != E; ++I) { 5093 switch (S.CompareImplicitConversionSequences(L->Conversions[I], 5094 R->Conversions[I])) { 5095 case ImplicitConversionSequence::Better: 5096 leftBetter++; 5097 break; 5098 5099 case ImplicitConversionSequence::Worse: 5100 leftBetter--; 5101 break; 5102 5103 case ImplicitConversionSequence::Indistinguishable: 5104 break; 5105 } 5106 } 5107 if (leftBetter > 0) return true; 5108 if (leftBetter < 0) return false; 5109 5110 } else if (R->FailureKind == ovl_fail_bad_conversion) 5111 return false; 5112 5113 // TODO: others? 5114 } 5115 5116 // Sort everything else by location. 5117 SourceLocation LLoc = GetLocationForCandidate(L); 5118 SourceLocation RLoc = GetLocationForCandidate(R); 5119 5120 // Put candidates without locations (e.g. builtins) at the end. 5121 if (LLoc.isInvalid()) return false; 5122 if (RLoc.isInvalid()) return true; 5123 5124 return S.SourceMgr.isBeforeInTranslationUnit(LLoc, RLoc); 5125 } 5126}; 5127 5128/// CompleteNonViableCandidate - Normally, overload resolution only 5129/// computes up to the first 5130void CompleteNonViableCandidate(Sema &S, OverloadCandidate *Cand, 5131 Expr **Args, unsigned NumArgs) { 5132 assert(!Cand->Viable); 5133 5134 // Don't do anything on failures other than bad conversion. 5135 if (Cand->FailureKind != ovl_fail_bad_conversion) return; 5136 5137 // Skip forward to the first bad conversion. 5138 unsigned ConvIdx = (Cand->IgnoreObjectArgument ? 1 : 0); 5139 unsigned ConvCount = Cand->Conversions.size(); 5140 while (true) { 5141 assert(ConvIdx != ConvCount && "no bad conversion in candidate"); 5142 ConvIdx++; 5143 if (Cand->Conversions[ConvIdx - 1].isBad()) 5144 break; 5145 } 5146 5147 if (ConvIdx == ConvCount) 5148 return; 5149 5150 assert(!Cand->Conversions[ConvIdx].isInitialized() && 5151 "remaining conversion is initialized?"); 5152 5153 // FIXME: these should probably be preserved from the overload 5154 // operation somehow. 5155 bool SuppressUserConversions = false; 5156 bool ForceRValue = false; 5157 5158 const FunctionProtoType* Proto; 5159 unsigned ArgIdx = ConvIdx; 5160 5161 if (Cand->IsSurrogate) { 5162 QualType ConvType 5163 = Cand->Surrogate->getConversionType().getNonReferenceType(); 5164 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 5165 ConvType = ConvPtrType->getPointeeType(); 5166 Proto = ConvType->getAs<FunctionProtoType>(); 5167 ArgIdx--; 5168 } else if (Cand->Function) { 5169 Proto = Cand->Function->getType()->getAs<FunctionProtoType>(); 5170 if (isa<CXXMethodDecl>(Cand->Function) && 5171 !isa<CXXConstructorDecl>(Cand->Function)) 5172 ArgIdx--; 5173 } else { 5174 // Builtin binary operator with a bad first conversion. 5175 assert(ConvCount <= 3); 5176 for (; ConvIdx != ConvCount; ++ConvIdx) 5177 Cand->Conversions[ConvIdx] 5178 = S.TryCopyInitialization(Args[ConvIdx], 5179 Cand->BuiltinTypes.ParamTypes[ConvIdx], 5180 SuppressUserConversions, ForceRValue, 5181 /*InOverloadResolution*/ true); 5182 return; 5183 } 5184 5185 // Fill in the rest of the conversions. 5186 unsigned NumArgsInProto = Proto->getNumArgs(); 5187 for (; ConvIdx != ConvCount; ++ConvIdx, ++ArgIdx) { 5188 if (ArgIdx < NumArgsInProto) 5189 Cand->Conversions[ConvIdx] 5190 = S.TryCopyInitialization(Args[ArgIdx], Proto->getArgType(ArgIdx), 5191 SuppressUserConversions, ForceRValue, 5192 /*InOverloadResolution=*/true); 5193 else 5194 Cand->Conversions[ConvIdx].setEllipsis(); 5195 } 5196} 5197 5198} // end anonymous namespace 5199 5200/// PrintOverloadCandidates - When overload resolution fails, prints 5201/// diagnostic messages containing the candidates in the candidate 5202/// set. 5203void 5204Sema::PrintOverloadCandidates(OverloadCandidateSet& CandidateSet, 5205 OverloadCandidateDisplayKind OCD, 5206 Expr **Args, unsigned NumArgs, 5207 const char *Opc, 5208 SourceLocation OpLoc) { 5209 // Sort the candidates by viability and position. Sorting directly would 5210 // be prohibitive, so we make a set of pointers and sort those. 5211 llvm::SmallVector<OverloadCandidate*, 32> Cands; 5212 if (OCD == OCD_AllCandidates) Cands.reserve(CandidateSet.size()); 5213 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 5214 LastCand = CandidateSet.end(); 5215 Cand != LastCand; ++Cand) { 5216 if (Cand->Viable) 5217 Cands.push_back(Cand); 5218 else if (OCD == OCD_AllCandidates) { 5219 CompleteNonViableCandidate(*this, Cand, Args, NumArgs); 5220 Cands.push_back(Cand); 5221 } 5222 } 5223 5224 std::sort(Cands.begin(), Cands.end(), 5225 CompareOverloadCandidatesForDisplay(*this)); 5226 5227 bool ReportedAmbiguousConversions = false; 5228 5229 llvm::SmallVectorImpl<OverloadCandidate*>::iterator I, E; 5230 for (I = Cands.begin(), E = Cands.end(); I != E; ++I) { 5231 OverloadCandidate *Cand = *I; 5232 5233 if (Cand->Function) 5234 NoteFunctionCandidate(*this, Cand, Args, NumArgs); 5235 else if (Cand->IsSurrogate) 5236 NoteSurrogateCandidate(*this, Cand); 5237 5238 // This a builtin candidate. We do not, in general, want to list 5239 // every possible builtin candidate. 5240 else if (Cand->Viable) { 5241 // Generally we only see ambiguities including viable builtin 5242 // operators if overload resolution got screwed up by an 5243 // ambiguous user-defined conversion. 5244 // 5245 // FIXME: It's quite possible for different conversions to see 5246 // different ambiguities, though. 5247 if (!ReportedAmbiguousConversions) { 5248 NoteAmbiguousUserConversions(*this, OpLoc, Cand); 5249 ReportedAmbiguousConversions = true; 5250 } 5251 5252 // If this is a viable builtin, print it. 5253 NoteBuiltinOperatorCandidate(*this, Opc, OpLoc, Cand); 5254 } 5255 } 5256} 5257 5258static bool CheckUnresolvedAccess(Sema &S, OverloadExpr *E, DeclAccessPair D) { 5259 if (isa<UnresolvedLookupExpr>(E)) 5260 return S.CheckUnresolvedLookupAccess(cast<UnresolvedLookupExpr>(E), D); 5261 5262 return S.CheckUnresolvedMemberAccess(cast<UnresolvedMemberExpr>(E), D); 5263} 5264 5265/// ResolveAddressOfOverloadedFunction - Try to resolve the address of 5266/// an overloaded function (C++ [over.over]), where @p From is an 5267/// expression with overloaded function type and @p ToType is the type 5268/// we're trying to resolve to. For example: 5269/// 5270/// @code 5271/// int f(double); 5272/// int f(int); 5273/// 5274/// int (*pfd)(double) = f; // selects f(double) 5275/// @endcode 5276/// 5277/// This routine returns the resulting FunctionDecl if it could be 5278/// resolved, and NULL otherwise. When @p Complain is true, this 5279/// routine will emit diagnostics if there is an error. 5280FunctionDecl * 5281Sema::ResolveAddressOfOverloadedFunction(Expr *From, QualType ToType, 5282 bool Complain, 5283 DeclAccessPair &FoundResult) { 5284 QualType FunctionType = ToType; 5285 bool IsMember = false; 5286 if (const PointerType *ToTypePtr = ToType->getAs<PointerType>()) 5287 FunctionType = ToTypePtr->getPointeeType(); 5288 else if (const ReferenceType *ToTypeRef = ToType->getAs<ReferenceType>()) 5289 FunctionType = ToTypeRef->getPointeeType(); 5290 else if (const MemberPointerType *MemTypePtr = 5291 ToType->getAs<MemberPointerType>()) { 5292 FunctionType = MemTypePtr->getPointeeType(); 5293 IsMember = true; 5294 } 5295 5296 // C++ [over.over]p1: 5297 // [...] [Note: any redundant set of parentheses surrounding the 5298 // overloaded function name is ignored (5.1). ] 5299 // C++ [over.over]p1: 5300 // [...] The overloaded function name can be preceded by the & 5301 // operator. 5302 OverloadExpr *OvlExpr = OverloadExpr::find(From).getPointer(); 5303 TemplateArgumentListInfo ETABuffer, *ExplicitTemplateArgs = 0; 5304 if (OvlExpr->hasExplicitTemplateArgs()) { 5305 OvlExpr->getExplicitTemplateArgs().copyInto(ETABuffer); 5306 ExplicitTemplateArgs = &ETABuffer; 5307 } 5308 5309 // We expect a pointer or reference to function, or a function pointer. 5310 FunctionType = Context.getCanonicalType(FunctionType).getUnqualifiedType(); 5311 if (!FunctionType->isFunctionType()) { 5312 if (Complain) 5313 Diag(From->getLocStart(), diag::err_addr_ovl_not_func_ptrref) 5314 << OvlExpr->getName() << ToType; 5315 5316 return 0; 5317 } 5318 5319 assert(From->getType() == Context.OverloadTy); 5320 5321 // Look through all of the overloaded functions, searching for one 5322 // whose type matches exactly. 5323 llvm::SmallVector<std::pair<DeclAccessPair, FunctionDecl*>, 4> Matches; 5324 llvm::SmallVector<FunctionDecl *, 4> NonMatches; 5325 5326 bool FoundNonTemplateFunction = false; 5327 for (UnresolvedSetIterator I = OvlExpr->decls_begin(), 5328 E = OvlExpr->decls_end(); I != E; ++I) { 5329 // Look through any using declarations to find the underlying function. 5330 NamedDecl *Fn = (*I)->getUnderlyingDecl(); 5331 5332 // C++ [over.over]p3: 5333 // Non-member functions and static member functions match 5334 // targets of type "pointer-to-function" or "reference-to-function." 5335 // Nonstatic member functions match targets of 5336 // type "pointer-to-member-function." 5337 // Note that according to DR 247, the containing class does not matter. 5338 5339 if (FunctionTemplateDecl *FunctionTemplate 5340 = dyn_cast<FunctionTemplateDecl>(Fn)) { 5341 if (CXXMethodDecl *Method 5342 = dyn_cast<CXXMethodDecl>(FunctionTemplate->getTemplatedDecl())) { 5343 // Skip non-static function templates when converting to pointer, and 5344 // static when converting to member pointer. 5345 if (Method->isStatic() == IsMember) 5346 continue; 5347 } else if (IsMember) 5348 continue; 5349 5350 // C++ [over.over]p2: 5351 // If the name is a function template, template argument deduction is 5352 // done (14.8.2.2), and if the argument deduction succeeds, the 5353 // resulting template argument list is used to generate a single 5354 // function template specialization, which is added to the set of 5355 // overloaded functions considered. 5356 // FIXME: We don't really want to build the specialization here, do we? 5357 FunctionDecl *Specialization = 0; 5358 TemplateDeductionInfo Info(Context, OvlExpr->getNameLoc()); 5359 if (TemplateDeductionResult Result 5360 = DeduceTemplateArguments(FunctionTemplate, ExplicitTemplateArgs, 5361 FunctionType, Specialization, Info)) { 5362 // FIXME: make a note of the failed deduction for diagnostics. 5363 (void)Result; 5364 } else { 5365 // FIXME: If the match isn't exact, shouldn't we just drop this as 5366 // a candidate? Find a testcase before changing the code. 5367 assert(FunctionType 5368 == Context.getCanonicalType(Specialization->getType())); 5369 Matches.push_back(std::make_pair(I.getPair(), 5370 cast<FunctionDecl>(Specialization->getCanonicalDecl()))); 5371 } 5372 5373 continue; 5374 } 5375 5376 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 5377 // Skip non-static functions when converting to pointer, and static 5378 // when converting to member pointer. 5379 if (Method->isStatic() == IsMember) 5380 continue; 5381 5382 // If we have explicit template arguments, skip non-templates. 5383 if (OvlExpr->hasExplicitTemplateArgs()) 5384 continue; 5385 } else if (IsMember) 5386 continue; 5387 5388 if (FunctionDecl *FunDecl = dyn_cast<FunctionDecl>(Fn)) { 5389 QualType ResultTy; 5390 if (Context.hasSameUnqualifiedType(FunctionType, FunDecl->getType()) || 5391 IsNoReturnConversion(Context, FunDecl->getType(), FunctionType, 5392 ResultTy)) { 5393 Matches.push_back(std::make_pair(I.getPair(), 5394 cast<FunctionDecl>(FunDecl->getCanonicalDecl()))); 5395 FoundNonTemplateFunction = true; 5396 } 5397 } 5398 } 5399 5400 // If there were 0 or 1 matches, we're done. 5401 if (Matches.empty()) { 5402 if (Complain) { 5403 Diag(From->getLocStart(), diag::err_addr_ovl_no_viable) 5404 << OvlExpr->getName() << FunctionType; 5405 for (UnresolvedSetIterator I = OvlExpr->decls_begin(), 5406 E = OvlExpr->decls_end(); 5407 I != E; ++I) 5408 if (FunctionDecl *F = dyn_cast<FunctionDecl>((*I)->getUnderlyingDecl())) 5409 NoteOverloadCandidate(F); 5410 } 5411 5412 return 0; 5413 } else if (Matches.size() == 1) { 5414 FunctionDecl *Result = Matches[0].second; 5415 FoundResult = Matches[0].first; 5416 MarkDeclarationReferenced(From->getLocStart(), Result); 5417 if (Complain) 5418 CheckAddressOfMemberAccess(OvlExpr, Matches[0].first); 5419 return Result; 5420 } 5421 5422 // C++ [over.over]p4: 5423 // If more than one function is selected, [...] 5424 if (!FoundNonTemplateFunction) { 5425 // [...] and any given function template specialization F1 is 5426 // eliminated if the set contains a second function template 5427 // specialization whose function template is more specialized 5428 // than the function template of F1 according to the partial 5429 // ordering rules of 14.5.5.2. 5430 5431 // The algorithm specified above is quadratic. We instead use a 5432 // two-pass algorithm (similar to the one used to identify the 5433 // best viable function in an overload set) that identifies the 5434 // best function template (if it exists). 5435 5436 UnresolvedSet<4> MatchesCopy; // TODO: avoid! 5437 for (unsigned I = 0, E = Matches.size(); I != E; ++I) 5438 MatchesCopy.addDecl(Matches[I].second, Matches[I].first.getAccess()); 5439 5440 UnresolvedSetIterator Result = 5441 getMostSpecialized(MatchesCopy.begin(), MatchesCopy.end(), 5442 TPOC_Other, From->getLocStart(), 5443 PDiag(), 5444 PDiag(diag::err_addr_ovl_ambiguous) 5445 << Matches[0].second->getDeclName(), 5446 PDiag(diag::note_ovl_candidate) 5447 << (unsigned) oc_function_template); 5448 assert(Result != MatchesCopy.end() && "no most-specialized template"); 5449 MarkDeclarationReferenced(From->getLocStart(), *Result); 5450 FoundResult = Matches[Result - MatchesCopy.begin()].first; 5451 if (Complain) 5452 CheckUnresolvedAccess(*this, OvlExpr, FoundResult); 5453 return cast<FunctionDecl>(*Result); 5454 } 5455 5456 // [...] any function template specializations in the set are 5457 // eliminated if the set also contains a non-template function, [...] 5458 for (unsigned I = 0, N = Matches.size(); I != N; ) { 5459 if (Matches[I].second->getPrimaryTemplate() == 0) 5460 ++I; 5461 else { 5462 Matches[I] = Matches[--N]; 5463 Matches.set_size(N); 5464 } 5465 } 5466 5467 // [...] After such eliminations, if any, there shall remain exactly one 5468 // selected function. 5469 if (Matches.size() == 1) { 5470 MarkDeclarationReferenced(From->getLocStart(), Matches[0].second); 5471 FoundResult = Matches[0].first; 5472 if (Complain) 5473 CheckUnresolvedAccess(*this, OvlExpr, Matches[0].first); 5474 return cast<FunctionDecl>(Matches[0].second); 5475 } 5476 5477 // FIXME: We should probably return the same thing that BestViableFunction 5478 // returns (even if we issue the diagnostics here). 5479 Diag(From->getLocStart(), diag::err_addr_ovl_ambiguous) 5480 << Matches[0].second->getDeclName(); 5481 for (unsigned I = 0, E = Matches.size(); I != E; ++I) 5482 NoteOverloadCandidate(Matches[I].second); 5483 return 0; 5484} 5485 5486/// \brief Given an expression that refers to an overloaded function, try to 5487/// resolve that overloaded function expression down to a single function. 5488/// 5489/// This routine can only resolve template-ids that refer to a single function 5490/// template, where that template-id refers to a single template whose template 5491/// arguments are either provided by the template-id or have defaults, 5492/// as described in C++0x [temp.arg.explicit]p3. 5493FunctionDecl *Sema::ResolveSingleFunctionTemplateSpecialization(Expr *From) { 5494 // C++ [over.over]p1: 5495 // [...] [Note: any redundant set of parentheses surrounding the 5496 // overloaded function name is ignored (5.1). ] 5497 // C++ [over.over]p1: 5498 // [...] The overloaded function name can be preceded by the & 5499 // operator. 5500 5501 if (From->getType() != Context.OverloadTy) 5502 return 0; 5503 5504 OverloadExpr *OvlExpr = OverloadExpr::find(From).getPointer(); 5505 5506 // If we didn't actually find any template-ids, we're done. 5507 if (!OvlExpr->hasExplicitTemplateArgs()) 5508 return 0; 5509 5510 TemplateArgumentListInfo ExplicitTemplateArgs; 5511 OvlExpr->getExplicitTemplateArgs().copyInto(ExplicitTemplateArgs); 5512 5513 // Look through all of the overloaded functions, searching for one 5514 // whose type matches exactly. 5515 FunctionDecl *Matched = 0; 5516 for (UnresolvedSetIterator I = OvlExpr->decls_begin(), 5517 E = OvlExpr->decls_end(); I != E; ++I) { 5518 // C++0x [temp.arg.explicit]p3: 5519 // [...] In contexts where deduction is done and fails, or in contexts 5520 // where deduction is not done, if a template argument list is 5521 // specified and it, along with any default template arguments, 5522 // identifies a single function template specialization, then the 5523 // template-id is an lvalue for the function template specialization. 5524 FunctionTemplateDecl *FunctionTemplate = cast<FunctionTemplateDecl>(*I); 5525 5526 // C++ [over.over]p2: 5527 // If the name is a function template, template argument deduction is 5528 // done (14.8.2.2), and if the argument deduction succeeds, the 5529 // resulting template argument list is used to generate a single 5530 // function template specialization, which is added to the set of 5531 // overloaded functions considered. 5532 FunctionDecl *Specialization = 0; 5533 TemplateDeductionInfo Info(Context, OvlExpr->getNameLoc()); 5534 if (TemplateDeductionResult Result 5535 = DeduceTemplateArguments(FunctionTemplate, &ExplicitTemplateArgs, 5536 Specialization, Info)) { 5537 // FIXME: make a note of the failed deduction for diagnostics. 5538 (void)Result; 5539 continue; 5540 } 5541 5542 // Multiple matches; we can't resolve to a single declaration. 5543 if (Matched) 5544 return 0; 5545 5546 Matched = Specialization; 5547 } 5548 5549 return Matched; 5550} 5551 5552/// \brief Add a single candidate to the overload set. 5553static void AddOverloadedCallCandidate(Sema &S, 5554 DeclAccessPair FoundDecl, 5555 const TemplateArgumentListInfo *ExplicitTemplateArgs, 5556 Expr **Args, unsigned NumArgs, 5557 OverloadCandidateSet &CandidateSet, 5558 bool PartialOverloading) { 5559 NamedDecl *Callee = FoundDecl.getDecl(); 5560 if (isa<UsingShadowDecl>(Callee)) 5561 Callee = cast<UsingShadowDecl>(Callee)->getTargetDecl(); 5562 5563 if (FunctionDecl *Func = dyn_cast<FunctionDecl>(Callee)) { 5564 assert(!ExplicitTemplateArgs && "Explicit template arguments?"); 5565 S.AddOverloadCandidate(Func, FoundDecl, Args, NumArgs, CandidateSet, 5566 false, false, PartialOverloading); 5567 return; 5568 } 5569 5570 if (FunctionTemplateDecl *FuncTemplate 5571 = dyn_cast<FunctionTemplateDecl>(Callee)) { 5572 S.AddTemplateOverloadCandidate(FuncTemplate, FoundDecl, 5573 ExplicitTemplateArgs, 5574 Args, NumArgs, CandidateSet); 5575 return; 5576 } 5577 5578 assert(false && "unhandled case in overloaded call candidate"); 5579 5580 // do nothing? 5581} 5582 5583/// \brief Add the overload candidates named by callee and/or found by argument 5584/// dependent lookup to the given overload set. 5585void Sema::AddOverloadedCallCandidates(UnresolvedLookupExpr *ULE, 5586 Expr **Args, unsigned NumArgs, 5587 OverloadCandidateSet &CandidateSet, 5588 bool PartialOverloading) { 5589 5590#ifndef NDEBUG 5591 // Verify that ArgumentDependentLookup is consistent with the rules 5592 // in C++0x [basic.lookup.argdep]p3: 5593 // 5594 // Let X be the lookup set produced by unqualified lookup (3.4.1) 5595 // and let Y be the lookup set produced by argument dependent 5596 // lookup (defined as follows). If X contains 5597 // 5598 // -- a declaration of a class member, or 5599 // 5600 // -- a block-scope function declaration that is not a 5601 // using-declaration, or 5602 // 5603 // -- a declaration that is neither a function or a function 5604 // template 5605 // 5606 // then Y is empty. 5607 5608 if (ULE->requiresADL()) { 5609 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(), 5610 E = ULE->decls_end(); I != E; ++I) { 5611 assert(!(*I)->getDeclContext()->isRecord()); 5612 assert(isa<UsingShadowDecl>(*I) || 5613 !(*I)->getDeclContext()->isFunctionOrMethod()); 5614 assert((*I)->getUnderlyingDecl()->isFunctionOrFunctionTemplate()); 5615 } 5616 } 5617#endif 5618 5619 // It would be nice to avoid this copy. 5620 TemplateArgumentListInfo TABuffer; 5621 const TemplateArgumentListInfo *ExplicitTemplateArgs = 0; 5622 if (ULE->hasExplicitTemplateArgs()) { 5623 ULE->copyTemplateArgumentsInto(TABuffer); 5624 ExplicitTemplateArgs = &TABuffer; 5625 } 5626 5627 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(), 5628 E = ULE->decls_end(); I != E; ++I) 5629 AddOverloadedCallCandidate(*this, I.getPair(), ExplicitTemplateArgs, 5630 Args, NumArgs, CandidateSet, 5631 PartialOverloading); 5632 5633 if (ULE->requiresADL()) 5634 AddArgumentDependentLookupCandidates(ULE->getName(), /*Operator*/ false, 5635 Args, NumArgs, 5636 ExplicitTemplateArgs, 5637 CandidateSet, 5638 PartialOverloading); 5639} 5640 5641static Sema::OwningExprResult Destroy(Sema &SemaRef, Expr *Fn, 5642 Expr **Args, unsigned NumArgs) { 5643 Fn->Destroy(SemaRef.Context); 5644 for (unsigned Arg = 0; Arg < NumArgs; ++Arg) 5645 Args[Arg]->Destroy(SemaRef.Context); 5646 return SemaRef.ExprError(); 5647} 5648 5649/// Attempts to recover from a call where no functions were found. 5650/// 5651/// Returns true if new candidates were found. 5652static Sema::OwningExprResult 5653BuildRecoveryCallExpr(Sema &SemaRef, Scope *S, Expr *Fn, 5654 UnresolvedLookupExpr *ULE, 5655 SourceLocation LParenLoc, 5656 Expr **Args, unsigned NumArgs, 5657 SourceLocation *CommaLocs, 5658 SourceLocation RParenLoc) { 5659 5660 CXXScopeSpec SS; 5661 if (ULE->getQualifier()) { 5662 SS.setScopeRep(ULE->getQualifier()); 5663 SS.setRange(ULE->getQualifierRange()); 5664 } 5665 5666 TemplateArgumentListInfo TABuffer; 5667 const TemplateArgumentListInfo *ExplicitTemplateArgs = 0; 5668 if (ULE->hasExplicitTemplateArgs()) { 5669 ULE->copyTemplateArgumentsInto(TABuffer); 5670 ExplicitTemplateArgs = &TABuffer; 5671 } 5672 5673 LookupResult R(SemaRef, ULE->getName(), ULE->getNameLoc(), 5674 Sema::LookupOrdinaryName); 5675 if (SemaRef.DiagnoseEmptyLookup(S, SS, R)) 5676 return Destroy(SemaRef, Fn, Args, NumArgs); 5677 5678 assert(!R.empty() && "lookup results empty despite recovery"); 5679 5680 // Build an implicit member call if appropriate. Just drop the 5681 // casts and such from the call, we don't really care. 5682 Sema::OwningExprResult NewFn = SemaRef.ExprError(); 5683 if ((*R.begin())->isCXXClassMember()) 5684 NewFn = SemaRef.BuildPossibleImplicitMemberExpr(SS, R, ExplicitTemplateArgs); 5685 else if (ExplicitTemplateArgs) 5686 NewFn = SemaRef.BuildTemplateIdExpr(SS, R, false, *ExplicitTemplateArgs); 5687 else 5688 NewFn = SemaRef.BuildDeclarationNameExpr(SS, R, false); 5689 5690 if (NewFn.isInvalid()) 5691 return Destroy(SemaRef, Fn, Args, NumArgs); 5692 5693 Fn->Destroy(SemaRef.Context); 5694 5695 // This shouldn't cause an infinite loop because we're giving it 5696 // an expression with non-empty lookup results, which should never 5697 // end up here. 5698 return SemaRef.ActOnCallExpr(/*Scope*/ 0, move(NewFn), LParenLoc, 5699 Sema::MultiExprArg(SemaRef, (void**) Args, NumArgs), 5700 CommaLocs, RParenLoc); 5701} 5702 5703/// ResolveOverloadedCallFn - Given the call expression that calls Fn 5704/// (which eventually refers to the declaration Func) and the call 5705/// arguments Args/NumArgs, attempt to resolve the function call down 5706/// to a specific function. If overload resolution succeeds, returns 5707/// the function declaration produced by overload 5708/// resolution. Otherwise, emits diagnostics, deletes all of the 5709/// arguments and Fn, and returns NULL. 5710Sema::OwningExprResult 5711Sema::BuildOverloadedCallExpr(Scope *S, Expr *Fn, UnresolvedLookupExpr *ULE, 5712 SourceLocation LParenLoc, 5713 Expr **Args, unsigned NumArgs, 5714 SourceLocation *CommaLocs, 5715 SourceLocation RParenLoc) { 5716#ifndef NDEBUG 5717 if (ULE->requiresADL()) { 5718 // To do ADL, we must have found an unqualified name. 5719 assert(!ULE->getQualifier() && "qualified name with ADL"); 5720 5721 // We don't perform ADL for implicit declarations of builtins. 5722 // Verify that this was correctly set up. 5723 FunctionDecl *F; 5724 if (ULE->decls_begin() + 1 == ULE->decls_end() && 5725 (F = dyn_cast<FunctionDecl>(*ULE->decls_begin())) && 5726 F->getBuiltinID() && F->isImplicit()) 5727 assert(0 && "performing ADL for builtin"); 5728 5729 // We don't perform ADL in C. 5730 assert(getLangOptions().CPlusPlus && "ADL enabled in C"); 5731 } 5732#endif 5733 5734 OverloadCandidateSet CandidateSet(Fn->getExprLoc()); 5735 5736 // Add the functions denoted by the callee to the set of candidate 5737 // functions, including those from argument-dependent lookup. 5738 AddOverloadedCallCandidates(ULE, Args, NumArgs, CandidateSet); 5739 5740 // If we found nothing, try to recover. 5741 // AddRecoveryCallCandidates diagnoses the error itself, so we just 5742 // bailout out if it fails. 5743 if (CandidateSet.empty()) 5744 return BuildRecoveryCallExpr(*this, S, Fn, ULE, LParenLoc, Args, NumArgs, 5745 CommaLocs, RParenLoc); 5746 5747 OverloadCandidateSet::iterator Best; 5748 switch (BestViableFunction(CandidateSet, Fn->getLocStart(), Best)) { 5749 case OR_Success: { 5750 FunctionDecl *FDecl = Best->Function; 5751 CheckUnresolvedLookupAccess(ULE, Best->FoundDecl); 5752 Fn = FixOverloadedFunctionReference(Fn, Best->FoundDecl, FDecl); 5753 return BuildResolvedCallExpr(Fn, FDecl, LParenLoc, Args, NumArgs, RParenLoc); 5754 } 5755 5756 case OR_No_Viable_Function: 5757 Diag(Fn->getSourceRange().getBegin(), 5758 diag::err_ovl_no_viable_function_in_call) 5759 << ULE->getName() << Fn->getSourceRange(); 5760 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 5761 break; 5762 5763 case OR_Ambiguous: 5764 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_ambiguous_call) 5765 << ULE->getName() << Fn->getSourceRange(); 5766 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, NumArgs); 5767 break; 5768 5769 case OR_Deleted: 5770 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_deleted_call) 5771 << Best->Function->isDeleted() 5772 << ULE->getName() 5773 << Fn->getSourceRange(); 5774 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 5775 break; 5776 } 5777 5778 // Overload resolution failed. Destroy all of the subexpressions and 5779 // return NULL. 5780 Fn->Destroy(Context); 5781 for (unsigned Arg = 0; Arg < NumArgs; ++Arg) 5782 Args[Arg]->Destroy(Context); 5783 return ExprError(); 5784} 5785 5786static bool IsOverloaded(const UnresolvedSetImpl &Functions) { 5787 return Functions.size() > 1 || 5788 (Functions.size() == 1 && isa<FunctionTemplateDecl>(*Functions.begin())); 5789} 5790 5791/// \brief Create a unary operation that may resolve to an overloaded 5792/// operator. 5793/// 5794/// \param OpLoc The location of the operator itself (e.g., '*'). 5795/// 5796/// \param OpcIn The UnaryOperator::Opcode that describes this 5797/// operator. 5798/// 5799/// \param Functions The set of non-member functions that will be 5800/// considered by overload resolution. The caller needs to build this 5801/// set based on the context using, e.g., 5802/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 5803/// set should not contain any member functions; those will be added 5804/// by CreateOverloadedUnaryOp(). 5805/// 5806/// \param input The input argument. 5807Sema::OwningExprResult 5808Sema::CreateOverloadedUnaryOp(SourceLocation OpLoc, unsigned OpcIn, 5809 const UnresolvedSetImpl &Fns, 5810 ExprArg input) { 5811 UnaryOperator::Opcode Opc = static_cast<UnaryOperator::Opcode>(OpcIn); 5812 Expr *Input = (Expr *)input.get(); 5813 5814 OverloadedOperatorKind Op = UnaryOperator::getOverloadedOperator(Opc); 5815 assert(Op != OO_None && "Invalid opcode for overloaded unary operator"); 5816 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 5817 5818 Expr *Args[2] = { Input, 0 }; 5819 unsigned NumArgs = 1; 5820 5821 // For post-increment and post-decrement, add the implicit '0' as 5822 // the second argument, so that we know this is a post-increment or 5823 // post-decrement. 5824 if (Opc == UnaryOperator::PostInc || Opc == UnaryOperator::PostDec) { 5825 llvm::APSInt Zero(Context.getTypeSize(Context.IntTy), false); 5826 Args[1] = new (Context) IntegerLiteral(Zero, Context.IntTy, 5827 SourceLocation()); 5828 NumArgs = 2; 5829 } 5830 5831 if (Input->isTypeDependent()) { 5832 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 5833 UnresolvedLookupExpr *Fn 5834 = UnresolvedLookupExpr::Create(Context, /*Dependent*/ true, NamingClass, 5835 0, SourceRange(), OpName, OpLoc, 5836 /*ADL*/ true, IsOverloaded(Fns)); 5837 Fn->addDecls(Fns.begin(), Fns.end()); 5838 5839 input.release(); 5840 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 5841 &Args[0], NumArgs, 5842 Context.DependentTy, 5843 OpLoc)); 5844 } 5845 5846 // Build an empty overload set. 5847 OverloadCandidateSet CandidateSet(OpLoc); 5848 5849 // Add the candidates from the given function set. 5850 AddFunctionCandidates(Fns, &Args[0], NumArgs, CandidateSet, false); 5851 5852 // Add operator candidates that are member functions. 5853 AddMemberOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 5854 5855 // Add candidates from ADL. 5856 AddArgumentDependentLookupCandidates(OpName, /*Operator*/ true, 5857 Args, NumArgs, 5858 /*ExplicitTemplateArgs*/ 0, 5859 CandidateSet); 5860 5861 // Add builtin operator candidates. 5862 AddBuiltinOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 5863 5864 // Perform overload resolution. 5865 OverloadCandidateSet::iterator Best; 5866 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 5867 case OR_Success: { 5868 // We found a built-in operator or an overloaded operator. 5869 FunctionDecl *FnDecl = Best->Function; 5870 5871 if (FnDecl) { 5872 // We matched an overloaded operator. Build a call to that 5873 // operator. 5874 5875 // Convert the arguments. 5876 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 5877 CheckMemberOperatorAccess(OpLoc, Args[0], 0, Best->FoundDecl); 5878 5879 if (PerformObjectArgumentInitialization(Input, /*Qualifier=*/0, 5880 Best->FoundDecl, Method)) 5881 return ExprError(); 5882 } else { 5883 // Convert the arguments. 5884 OwningExprResult InputInit 5885 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 5886 FnDecl->getParamDecl(0)), 5887 SourceLocation(), 5888 move(input)); 5889 if (InputInit.isInvalid()) 5890 return ExprError(); 5891 5892 input = move(InputInit); 5893 Input = (Expr *)input.get(); 5894 } 5895 5896 // Determine the result type 5897 QualType ResultTy = FnDecl->getResultType().getNonReferenceType(); 5898 5899 // Build the actual expression node. 5900 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 5901 SourceLocation()); 5902 UsualUnaryConversions(FnExpr); 5903 5904 input.release(); 5905 Args[0] = Input; 5906 ExprOwningPtr<CallExpr> TheCall(this, 5907 new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 5908 Args, NumArgs, ResultTy, OpLoc)); 5909 5910 if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall.get(), 5911 FnDecl)) 5912 return ExprError(); 5913 5914 return MaybeBindToTemporary(TheCall.release()); 5915 } else { 5916 // We matched a built-in operator. Convert the arguments, then 5917 // break out so that we will build the appropriate built-in 5918 // operator node. 5919 if (PerformImplicitConversion(Input, Best->BuiltinTypes.ParamTypes[0], 5920 Best->Conversions[0], AA_Passing)) 5921 return ExprError(); 5922 5923 break; 5924 } 5925 } 5926 5927 case OR_No_Viable_Function: 5928 // No viable function; fall through to handling this as a 5929 // built-in operator, which will produce an error message for us. 5930 break; 5931 5932 case OR_Ambiguous: 5933 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 5934 << UnaryOperator::getOpcodeStr(Opc) 5935 << Input->getSourceRange(); 5936 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, NumArgs, 5937 UnaryOperator::getOpcodeStr(Opc), OpLoc); 5938 return ExprError(); 5939 5940 case OR_Deleted: 5941 Diag(OpLoc, diag::err_ovl_deleted_oper) 5942 << Best->Function->isDeleted() 5943 << UnaryOperator::getOpcodeStr(Opc) 5944 << Input->getSourceRange(); 5945 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 5946 return ExprError(); 5947 } 5948 5949 // Either we found no viable overloaded operator or we matched a 5950 // built-in operator. In either case, fall through to trying to 5951 // build a built-in operation. 5952 input.release(); 5953 return CreateBuiltinUnaryOp(OpLoc, Opc, Owned(Input)); 5954} 5955 5956/// \brief Create a binary operation that may resolve to an overloaded 5957/// operator. 5958/// 5959/// \param OpLoc The location of the operator itself (e.g., '+'). 5960/// 5961/// \param OpcIn The BinaryOperator::Opcode that describes this 5962/// operator. 5963/// 5964/// \param Functions The set of non-member functions that will be 5965/// considered by overload resolution. The caller needs to build this 5966/// set based on the context using, e.g., 5967/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 5968/// set should not contain any member functions; those will be added 5969/// by CreateOverloadedBinOp(). 5970/// 5971/// \param LHS Left-hand argument. 5972/// \param RHS Right-hand argument. 5973Sema::OwningExprResult 5974Sema::CreateOverloadedBinOp(SourceLocation OpLoc, 5975 unsigned OpcIn, 5976 const UnresolvedSetImpl &Fns, 5977 Expr *LHS, Expr *RHS) { 5978 Expr *Args[2] = { LHS, RHS }; 5979 LHS=RHS=0; //Please use only Args instead of LHS/RHS couple 5980 5981 BinaryOperator::Opcode Opc = static_cast<BinaryOperator::Opcode>(OpcIn); 5982 OverloadedOperatorKind Op = BinaryOperator::getOverloadedOperator(Opc); 5983 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 5984 5985 // If either side is type-dependent, create an appropriate dependent 5986 // expression. 5987 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 5988 if (Fns.empty()) { 5989 // If there are no functions to store, just build a dependent 5990 // BinaryOperator or CompoundAssignment. 5991 if (Opc <= BinaryOperator::Assign || Opc > BinaryOperator::OrAssign) 5992 return Owned(new (Context) BinaryOperator(Args[0], Args[1], Opc, 5993 Context.DependentTy, OpLoc)); 5994 5995 return Owned(new (Context) CompoundAssignOperator(Args[0], Args[1], Opc, 5996 Context.DependentTy, 5997 Context.DependentTy, 5998 Context.DependentTy, 5999 OpLoc)); 6000 } 6001 6002 // FIXME: save results of ADL from here? 6003 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 6004 UnresolvedLookupExpr *Fn 6005 = UnresolvedLookupExpr::Create(Context, /*Dependent*/ true, NamingClass, 6006 0, SourceRange(), OpName, OpLoc, 6007 /*ADL*/ true, IsOverloaded(Fns)); 6008 6009 Fn->addDecls(Fns.begin(), Fns.end()); 6010 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 6011 Args, 2, 6012 Context.DependentTy, 6013 OpLoc)); 6014 } 6015 6016 // If this is the .* operator, which is not overloadable, just 6017 // create a built-in binary operator. 6018 if (Opc == BinaryOperator::PtrMemD) 6019 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 6020 6021 // If this is the assignment operator, we only perform overload resolution 6022 // if the left-hand side is a class or enumeration type. This is actually 6023 // a hack. The standard requires that we do overload resolution between the 6024 // various built-in candidates, but as DR507 points out, this can lead to 6025 // problems. So we do it this way, which pretty much follows what GCC does. 6026 // Note that we go the traditional code path for compound assignment forms. 6027 if (Opc==BinaryOperator::Assign && !Args[0]->getType()->isOverloadableType()) 6028 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 6029 6030 // Build an empty overload set. 6031 OverloadCandidateSet CandidateSet(OpLoc); 6032 6033 // Add the candidates from the given function set. 6034 AddFunctionCandidates(Fns, Args, 2, CandidateSet, false); 6035 6036 // Add operator candidates that are member functions. 6037 AddMemberOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 6038 6039 // Add candidates from ADL. 6040 AddArgumentDependentLookupCandidates(OpName, /*Operator*/ true, 6041 Args, 2, 6042 /*ExplicitTemplateArgs*/ 0, 6043 CandidateSet); 6044 6045 // Add builtin operator candidates. 6046 AddBuiltinOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 6047 6048 // Perform overload resolution. 6049 OverloadCandidateSet::iterator Best; 6050 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 6051 case OR_Success: { 6052 // We found a built-in operator or an overloaded operator. 6053 FunctionDecl *FnDecl = Best->Function; 6054 6055 if (FnDecl) { 6056 // We matched an overloaded operator. Build a call to that 6057 // operator. 6058 6059 // Convert the arguments. 6060 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 6061 // Best->Access is only meaningful for class members. 6062 CheckMemberOperatorAccess(OpLoc, Args[0], Args[1], Best->FoundDecl); 6063 6064 OwningExprResult Arg1 6065 = PerformCopyInitialization( 6066 InitializedEntity::InitializeParameter( 6067 FnDecl->getParamDecl(0)), 6068 SourceLocation(), 6069 Owned(Args[1])); 6070 if (Arg1.isInvalid()) 6071 return ExprError(); 6072 6073 if (PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/0, 6074 Best->FoundDecl, Method)) 6075 return ExprError(); 6076 6077 Args[1] = RHS = Arg1.takeAs<Expr>(); 6078 } else { 6079 // Convert the arguments. 6080 OwningExprResult Arg0 6081 = PerformCopyInitialization( 6082 InitializedEntity::InitializeParameter( 6083 FnDecl->getParamDecl(0)), 6084 SourceLocation(), 6085 Owned(Args[0])); 6086 if (Arg0.isInvalid()) 6087 return ExprError(); 6088 6089 OwningExprResult Arg1 6090 = PerformCopyInitialization( 6091 InitializedEntity::InitializeParameter( 6092 FnDecl->getParamDecl(1)), 6093 SourceLocation(), 6094 Owned(Args[1])); 6095 if (Arg1.isInvalid()) 6096 return ExprError(); 6097 Args[0] = LHS = Arg0.takeAs<Expr>(); 6098 Args[1] = RHS = Arg1.takeAs<Expr>(); 6099 } 6100 6101 // Determine the result type 6102 QualType ResultTy 6103 = FnDecl->getType()->getAs<FunctionType>()->getResultType(); 6104 ResultTy = ResultTy.getNonReferenceType(); 6105 6106 // Build the actual expression node. 6107 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 6108 OpLoc); 6109 UsualUnaryConversions(FnExpr); 6110 6111 ExprOwningPtr<CXXOperatorCallExpr> 6112 TheCall(this, new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 6113 Args, 2, ResultTy, 6114 OpLoc)); 6115 6116 if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall.get(), 6117 FnDecl)) 6118 return ExprError(); 6119 6120 return MaybeBindToTemporary(TheCall.release()); 6121 } else { 6122 // We matched a built-in operator. Convert the arguments, then 6123 // break out so that we will build the appropriate built-in 6124 // operator node. 6125 if (PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 6126 Best->Conversions[0], AA_Passing) || 6127 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 6128 Best->Conversions[1], AA_Passing)) 6129 return ExprError(); 6130 6131 break; 6132 } 6133 } 6134 6135 case OR_No_Viable_Function: { 6136 // C++ [over.match.oper]p9: 6137 // If the operator is the operator , [...] and there are no 6138 // viable functions, then the operator is assumed to be the 6139 // built-in operator and interpreted according to clause 5. 6140 if (Opc == BinaryOperator::Comma) 6141 break; 6142 6143 // For class as left operand for assignment or compound assigment operator 6144 // do not fall through to handling in built-in, but report that no overloaded 6145 // assignment operator found 6146 OwningExprResult Result = ExprError(); 6147 if (Args[0]->getType()->isRecordType() && 6148 Opc >= BinaryOperator::Assign && Opc <= BinaryOperator::OrAssign) { 6149 Diag(OpLoc, diag::err_ovl_no_viable_oper) 6150 << BinaryOperator::getOpcodeStr(Opc) 6151 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 6152 } else { 6153 // No viable function; try to create a built-in operation, which will 6154 // produce an error. Then, show the non-viable candidates. 6155 Result = CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 6156 } 6157 assert(Result.isInvalid() && 6158 "C++ binary operator overloading is missing candidates!"); 6159 if (Result.isInvalid()) 6160 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2, 6161 BinaryOperator::getOpcodeStr(Opc), OpLoc); 6162 return move(Result); 6163 } 6164 6165 case OR_Ambiguous: 6166 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 6167 << BinaryOperator::getOpcodeStr(Opc) 6168 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 6169 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, 2, 6170 BinaryOperator::getOpcodeStr(Opc), OpLoc); 6171 return ExprError(); 6172 6173 case OR_Deleted: 6174 Diag(OpLoc, diag::err_ovl_deleted_oper) 6175 << Best->Function->isDeleted() 6176 << BinaryOperator::getOpcodeStr(Opc) 6177 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 6178 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2); 6179 return ExprError(); 6180 } 6181 6182 // We matched a built-in operator; build it. 6183 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 6184} 6185 6186Action::OwningExprResult 6187Sema::CreateOverloadedArraySubscriptExpr(SourceLocation LLoc, 6188 SourceLocation RLoc, 6189 ExprArg Base, ExprArg Idx) { 6190 Expr *Args[2] = { static_cast<Expr*>(Base.get()), 6191 static_cast<Expr*>(Idx.get()) }; 6192 DeclarationName OpName = 6193 Context.DeclarationNames.getCXXOperatorName(OO_Subscript); 6194 6195 // If either side is type-dependent, create an appropriate dependent 6196 // expression. 6197 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 6198 6199 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 6200 UnresolvedLookupExpr *Fn 6201 = UnresolvedLookupExpr::Create(Context, /*Dependent*/ true, NamingClass, 6202 0, SourceRange(), OpName, LLoc, 6203 /*ADL*/ true, /*Overloaded*/ false); 6204 // Can't add any actual overloads yet 6205 6206 Base.release(); 6207 Idx.release(); 6208 return Owned(new (Context) CXXOperatorCallExpr(Context, OO_Subscript, Fn, 6209 Args, 2, 6210 Context.DependentTy, 6211 RLoc)); 6212 } 6213 6214 // Build an empty overload set. 6215 OverloadCandidateSet CandidateSet(LLoc); 6216 6217 // Subscript can only be overloaded as a member function. 6218 6219 // Add operator candidates that are member functions. 6220 AddMemberOperatorCandidates(OO_Subscript, LLoc, Args, 2, CandidateSet); 6221 6222 // Add builtin operator candidates. 6223 AddBuiltinOperatorCandidates(OO_Subscript, LLoc, Args, 2, CandidateSet); 6224 6225 // Perform overload resolution. 6226 OverloadCandidateSet::iterator Best; 6227 switch (BestViableFunction(CandidateSet, LLoc, Best)) { 6228 case OR_Success: { 6229 // We found a built-in operator or an overloaded operator. 6230 FunctionDecl *FnDecl = Best->Function; 6231 6232 if (FnDecl) { 6233 // We matched an overloaded operator. Build a call to that 6234 // operator. 6235 6236 CheckMemberOperatorAccess(LLoc, Args[0], Args[1], Best->FoundDecl); 6237 6238 // Convert the arguments. 6239 CXXMethodDecl *Method = cast<CXXMethodDecl>(FnDecl); 6240 if (PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/0, 6241 Best->FoundDecl, Method)) 6242 return ExprError(); 6243 6244 // Convert the arguments. 6245 OwningExprResult InputInit 6246 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 6247 FnDecl->getParamDecl(0)), 6248 SourceLocation(), 6249 Owned(Args[1])); 6250 if (InputInit.isInvalid()) 6251 return ExprError(); 6252 6253 Args[1] = InputInit.takeAs<Expr>(); 6254 6255 // Determine the result type 6256 QualType ResultTy 6257 = FnDecl->getType()->getAs<FunctionType>()->getResultType(); 6258 ResultTy = ResultTy.getNonReferenceType(); 6259 6260 // Build the actual expression node. 6261 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 6262 LLoc); 6263 UsualUnaryConversions(FnExpr); 6264 6265 Base.release(); 6266 Idx.release(); 6267 ExprOwningPtr<CXXOperatorCallExpr> 6268 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Subscript, 6269 FnExpr, Args, 2, 6270 ResultTy, RLoc)); 6271 6272 if (CheckCallReturnType(FnDecl->getResultType(), LLoc, TheCall.get(), 6273 FnDecl)) 6274 return ExprError(); 6275 6276 return MaybeBindToTemporary(TheCall.release()); 6277 } else { 6278 // We matched a built-in operator. Convert the arguments, then 6279 // break out so that we will build the appropriate built-in 6280 // operator node. 6281 if (PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 6282 Best->Conversions[0], AA_Passing) || 6283 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 6284 Best->Conversions[1], AA_Passing)) 6285 return ExprError(); 6286 6287 break; 6288 } 6289 } 6290 6291 case OR_No_Viable_Function: { 6292 if (CandidateSet.empty()) 6293 Diag(LLoc, diag::err_ovl_no_oper) 6294 << Args[0]->getType() << /*subscript*/ 0 6295 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 6296 else 6297 Diag(LLoc, diag::err_ovl_no_viable_subscript) 6298 << Args[0]->getType() 6299 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 6300 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2, 6301 "[]", LLoc); 6302 return ExprError(); 6303 } 6304 6305 case OR_Ambiguous: 6306 Diag(LLoc, diag::err_ovl_ambiguous_oper) 6307 << "[]" << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 6308 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, 2, 6309 "[]", LLoc); 6310 return ExprError(); 6311 6312 case OR_Deleted: 6313 Diag(LLoc, diag::err_ovl_deleted_oper) 6314 << Best->Function->isDeleted() << "[]" 6315 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 6316 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2, 6317 "[]", LLoc); 6318 return ExprError(); 6319 } 6320 6321 // We matched a built-in operator; build it. 6322 Base.release(); 6323 Idx.release(); 6324 return CreateBuiltinArraySubscriptExpr(Owned(Args[0]), LLoc, 6325 Owned(Args[1]), RLoc); 6326} 6327 6328/// BuildCallToMemberFunction - Build a call to a member 6329/// function. MemExpr is the expression that refers to the member 6330/// function (and includes the object parameter), Args/NumArgs are the 6331/// arguments to the function call (not including the object 6332/// parameter). The caller needs to validate that the member 6333/// expression refers to a member function or an overloaded member 6334/// function. 6335Sema::OwningExprResult 6336Sema::BuildCallToMemberFunction(Scope *S, Expr *MemExprE, 6337 SourceLocation LParenLoc, Expr **Args, 6338 unsigned NumArgs, SourceLocation *CommaLocs, 6339 SourceLocation RParenLoc) { 6340 // Dig out the member expression. This holds both the object 6341 // argument and the member function we're referring to. 6342 Expr *NakedMemExpr = MemExprE->IgnoreParens(); 6343 6344 MemberExpr *MemExpr; 6345 CXXMethodDecl *Method = 0; 6346 DeclAccessPair FoundDecl = DeclAccessPair::make(0, AS_public); 6347 NestedNameSpecifier *Qualifier = 0; 6348 if (isa<MemberExpr>(NakedMemExpr)) { 6349 MemExpr = cast<MemberExpr>(NakedMemExpr); 6350 Method = cast<CXXMethodDecl>(MemExpr->getMemberDecl()); 6351 FoundDecl = MemExpr->getFoundDecl(); 6352 Qualifier = MemExpr->getQualifier(); 6353 } else { 6354 UnresolvedMemberExpr *UnresExpr = cast<UnresolvedMemberExpr>(NakedMemExpr); 6355 Qualifier = UnresExpr->getQualifier(); 6356 6357 QualType ObjectType = UnresExpr->getBaseType(); 6358 6359 // Add overload candidates 6360 OverloadCandidateSet CandidateSet(UnresExpr->getMemberLoc()); 6361 6362 // FIXME: avoid copy. 6363 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 6364 if (UnresExpr->hasExplicitTemplateArgs()) { 6365 UnresExpr->copyTemplateArgumentsInto(TemplateArgsBuffer); 6366 TemplateArgs = &TemplateArgsBuffer; 6367 } 6368 6369 for (UnresolvedMemberExpr::decls_iterator I = UnresExpr->decls_begin(), 6370 E = UnresExpr->decls_end(); I != E; ++I) { 6371 6372 NamedDecl *Func = *I; 6373 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(Func->getDeclContext()); 6374 if (isa<UsingShadowDecl>(Func)) 6375 Func = cast<UsingShadowDecl>(Func)->getTargetDecl(); 6376 6377 if ((Method = dyn_cast<CXXMethodDecl>(Func))) { 6378 // If explicit template arguments were provided, we can't call a 6379 // non-template member function. 6380 if (TemplateArgs) 6381 continue; 6382 6383 AddMethodCandidate(Method, I.getPair(), ActingDC, ObjectType, 6384 Args, NumArgs, 6385 CandidateSet, /*SuppressUserConversions=*/false); 6386 } else { 6387 AddMethodTemplateCandidate(cast<FunctionTemplateDecl>(Func), 6388 I.getPair(), ActingDC, TemplateArgs, 6389 ObjectType, Args, NumArgs, 6390 CandidateSet, 6391 /*SuppressUsedConversions=*/false); 6392 } 6393 } 6394 6395 DeclarationName DeclName = UnresExpr->getMemberName(); 6396 6397 OverloadCandidateSet::iterator Best; 6398 switch (BestViableFunction(CandidateSet, UnresExpr->getLocStart(), Best)) { 6399 case OR_Success: 6400 Method = cast<CXXMethodDecl>(Best->Function); 6401 FoundDecl = Best->FoundDecl; 6402 CheckUnresolvedMemberAccess(UnresExpr, Best->FoundDecl); 6403 break; 6404 6405 case OR_No_Viable_Function: 6406 Diag(UnresExpr->getMemberLoc(), 6407 diag::err_ovl_no_viable_member_function_in_call) 6408 << DeclName << MemExprE->getSourceRange(); 6409 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6410 // FIXME: Leaking incoming expressions! 6411 return ExprError(); 6412 6413 case OR_Ambiguous: 6414 Diag(UnresExpr->getMemberLoc(), diag::err_ovl_ambiguous_member_call) 6415 << DeclName << MemExprE->getSourceRange(); 6416 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6417 // FIXME: Leaking incoming expressions! 6418 return ExprError(); 6419 6420 case OR_Deleted: 6421 Diag(UnresExpr->getMemberLoc(), diag::err_ovl_deleted_member_call) 6422 << Best->Function->isDeleted() 6423 << DeclName << MemExprE->getSourceRange(); 6424 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6425 // FIXME: Leaking incoming expressions! 6426 return ExprError(); 6427 } 6428 6429 MemExprE = FixOverloadedFunctionReference(MemExprE, FoundDecl, Method); 6430 6431 // If overload resolution picked a static member, build a 6432 // non-member call based on that function. 6433 if (Method->isStatic()) { 6434 return BuildResolvedCallExpr(MemExprE, Method, LParenLoc, 6435 Args, NumArgs, RParenLoc); 6436 } 6437 6438 MemExpr = cast<MemberExpr>(MemExprE->IgnoreParens()); 6439 } 6440 6441 assert(Method && "Member call to something that isn't a method?"); 6442 ExprOwningPtr<CXXMemberCallExpr> 6443 TheCall(this, new (Context) CXXMemberCallExpr(Context, MemExprE, Args, 6444 NumArgs, 6445 Method->getResultType().getNonReferenceType(), 6446 RParenLoc)); 6447 6448 // Check for a valid return type. 6449 if (CheckCallReturnType(Method->getResultType(), MemExpr->getMemberLoc(), 6450 TheCall.get(), Method)) 6451 return ExprError(); 6452 6453 // Convert the object argument (for a non-static member function call). 6454 // We only need to do this if there was actually an overload; otherwise 6455 // it was done at lookup. 6456 Expr *ObjectArg = MemExpr->getBase(); 6457 if (!Method->isStatic() && 6458 PerformObjectArgumentInitialization(ObjectArg, Qualifier, 6459 FoundDecl, Method)) 6460 return ExprError(); 6461 MemExpr->setBase(ObjectArg); 6462 6463 // Convert the rest of the arguments 6464 const FunctionProtoType *Proto = cast<FunctionProtoType>(Method->getType()); 6465 if (ConvertArgumentsForCall(&*TheCall, MemExpr, Method, Proto, Args, NumArgs, 6466 RParenLoc)) 6467 return ExprError(); 6468 6469 if (CheckFunctionCall(Method, TheCall.get())) 6470 return ExprError(); 6471 6472 return MaybeBindToTemporary(TheCall.release()); 6473} 6474 6475/// BuildCallToObjectOfClassType - Build a call to an object of class 6476/// type (C++ [over.call.object]), which can end up invoking an 6477/// overloaded function call operator (@c operator()) or performing a 6478/// user-defined conversion on the object argument. 6479Sema::ExprResult 6480Sema::BuildCallToObjectOfClassType(Scope *S, Expr *Object, 6481 SourceLocation LParenLoc, 6482 Expr **Args, unsigned NumArgs, 6483 SourceLocation *CommaLocs, 6484 SourceLocation RParenLoc) { 6485 assert(Object->getType()->isRecordType() && "Requires object type argument"); 6486 const RecordType *Record = Object->getType()->getAs<RecordType>(); 6487 6488 // C++ [over.call.object]p1: 6489 // If the primary-expression E in the function call syntax 6490 // evaluates to a class object of type "cv T", then the set of 6491 // candidate functions includes at least the function call 6492 // operators of T. The function call operators of T are obtained by 6493 // ordinary lookup of the name operator() in the context of 6494 // (E).operator(). 6495 OverloadCandidateSet CandidateSet(LParenLoc); 6496 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Call); 6497 6498 if (RequireCompleteType(LParenLoc, Object->getType(), 6499 PDiag(diag::err_incomplete_object_call) 6500 << Object->getSourceRange())) 6501 return true; 6502 6503 LookupResult R(*this, OpName, LParenLoc, LookupOrdinaryName); 6504 LookupQualifiedName(R, Record->getDecl()); 6505 R.suppressDiagnostics(); 6506 6507 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 6508 Oper != OperEnd; ++Oper) { 6509 AddMethodCandidate(Oper.getPair(), Object->getType(), 6510 Args, NumArgs, CandidateSet, 6511 /*SuppressUserConversions=*/ false); 6512 } 6513 6514 // C++ [over.call.object]p2: 6515 // In addition, for each conversion function declared in T of the 6516 // form 6517 // 6518 // operator conversion-type-id () cv-qualifier; 6519 // 6520 // where cv-qualifier is the same cv-qualification as, or a 6521 // greater cv-qualification than, cv, and where conversion-type-id 6522 // denotes the type "pointer to function of (P1,...,Pn) returning 6523 // R", or the type "reference to pointer to function of 6524 // (P1,...,Pn) returning R", or the type "reference to function 6525 // of (P1,...,Pn) returning R", a surrogate call function [...] 6526 // is also considered as a candidate function. Similarly, 6527 // surrogate call functions are added to the set of candidate 6528 // functions for each conversion function declared in an 6529 // accessible base class provided the function is not hidden 6530 // within T by another intervening declaration. 6531 const UnresolvedSetImpl *Conversions 6532 = cast<CXXRecordDecl>(Record->getDecl())->getVisibleConversionFunctions(); 6533 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 6534 E = Conversions->end(); I != E; ++I) { 6535 NamedDecl *D = *I; 6536 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext()); 6537 if (isa<UsingShadowDecl>(D)) 6538 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 6539 6540 // Skip over templated conversion functions; they aren't 6541 // surrogates. 6542 if (isa<FunctionTemplateDecl>(D)) 6543 continue; 6544 6545 CXXConversionDecl *Conv = cast<CXXConversionDecl>(D); 6546 6547 // Strip the reference type (if any) and then the pointer type (if 6548 // any) to get down to what might be a function type. 6549 QualType ConvType = Conv->getConversionType().getNonReferenceType(); 6550 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 6551 ConvType = ConvPtrType->getPointeeType(); 6552 6553 if (const FunctionProtoType *Proto = ConvType->getAs<FunctionProtoType>()) 6554 AddSurrogateCandidate(Conv, I.getPair(), ActingContext, Proto, 6555 Object->getType(), Args, NumArgs, 6556 CandidateSet); 6557 } 6558 6559 // Perform overload resolution. 6560 OverloadCandidateSet::iterator Best; 6561 switch (BestViableFunction(CandidateSet, Object->getLocStart(), Best)) { 6562 case OR_Success: 6563 // Overload resolution succeeded; we'll build the appropriate call 6564 // below. 6565 break; 6566 6567 case OR_No_Viable_Function: 6568 if (CandidateSet.empty()) 6569 Diag(Object->getSourceRange().getBegin(), diag::err_ovl_no_oper) 6570 << Object->getType() << /*call*/ 1 6571 << Object->getSourceRange(); 6572 else 6573 Diag(Object->getSourceRange().getBegin(), 6574 diag::err_ovl_no_viable_object_call) 6575 << Object->getType() << Object->getSourceRange(); 6576 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6577 break; 6578 6579 case OR_Ambiguous: 6580 Diag(Object->getSourceRange().getBegin(), 6581 diag::err_ovl_ambiguous_object_call) 6582 << Object->getType() << Object->getSourceRange(); 6583 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, NumArgs); 6584 break; 6585 6586 case OR_Deleted: 6587 Diag(Object->getSourceRange().getBegin(), 6588 diag::err_ovl_deleted_object_call) 6589 << Best->Function->isDeleted() 6590 << Object->getType() << Object->getSourceRange(); 6591 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6592 break; 6593 } 6594 6595 if (Best == CandidateSet.end()) { 6596 // We had an error; delete all of the subexpressions and return 6597 // the error. 6598 Object->Destroy(Context); 6599 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 6600 Args[ArgIdx]->Destroy(Context); 6601 return true; 6602 } 6603 6604 if (Best->Function == 0) { 6605 // Since there is no function declaration, this is one of the 6606 // surrogate candidates. Dig out the conversion function. 6607 CXXConversionDecl *Conv 6608 = cast<CXXConversionDecl>( 6609 Best->Conversions[0].UserDefined.ConversionFunction); 6610 6611 CheckMemberOperatorAccess(LParenLoc, Object, 0, Best->FoundDecl); 6612 6613 // We selected one of the surrogate functions that converts the 6614 // object parameter to a function pointer. Perform the conversion 6615 // on the object argument, then let ActOnCallExpr finish the job. 6616 6617 // Create an implicit member expr to refer to the conversion operator. 6618 // and then call it. 6619 CXXMemberCallExpr *CE = BuildCXXMemberCallExpr(Object, Best->FoundDecl, 6620 Conv); 6621 6622 return ActOnCallExpr(S, ExprArg(*this, CE), LParenLoc, 6623 MultiExprArg(*this, (ExprTy**)Args, NumArgs), 6624 CommaLocs, RParenLoc).result(); 6625 } 6626 6627 CheckMemberOperatorAccess(LParenLoc, Object, 0, Best->FoundDecl); 6628 6629 // We found an overloaded operator(). Build a CXXOperatorCallExpr 6630 // that calls this method, using Object for the implicit object 6631 // parameter and passing along the remaining arguments. 6632 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 6633 const FunctionProtoType *Proto = Method->getType()->getAs<FunctionProtoType>(); 6634 6635 unsigned NumArgsInProto = Proto->getNumArgs(); 6636 unsigned NumArgsToCheck = NumArgs; 6637 6638 // Build the full argument list for the method call (the 6639 // implicit object parameter is placed at the beginning of the 6640 // list). 6641 Expr **MethodArgs; 6642 if (NumArgs < NumArgsInProto) { 6643 NumArgsToCheck = NumArgsInProto; 6644 MethodArgs = new Expr*[NumArgsInProto + 1]; 6645 } else { 6646 MethodArgs = new Expr*[NumArgs + 1]; 6647 } 6648 MethodArgs[0] = Object; 6649 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 6650 MethodArgs[ArgIdx + 1] = Args[ArgIdx]; 6651 6652 Expr *NewFn = new (Context) DeclRefExpr(Method, Method->getType(), 6653 SourceLocation()); 6654 UsualUnaryConversions(NewFn); 6655 6656 // Once we've built TheCall, all of the expressions are properly 6657 // owned. 6658 QualType ResultTy = Method->getResultType().getNonReferenceType(); 6659 ExprOwningPtr<CXXOperatorCallExpr> 6660 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Call, NewFn, 6661 MethodArgs, NumArgs + 1, 6662 ResultTy, RParenLoc)); 6663 delete [] MethodArgs; 6664 6665 if (CheckCallReturnType(Method->getResultType(), LParenLoc, TheCall.get(), 6666 Method)) 6667 return true; 6668 6669 // We may have default arguments. If so, we need to allocate more 6670 // slots in the call for them. 6671 if (NumArgs < NumArgsInProto) 6672 TheCall->setNumArgs(Context, NumArgsInProto + 1); 6673 else if (NumArgs > NumArgsInProto) 6674 NumArgsToCheck = NumArgsInProto; 6675 6676 bool IsError = false; 6677 6678 // Initialize the implicit object parameter. 6679 IsError |= PerformObjectArgumentInitialization(Object, /*Qualifier=*/0, 6680 Best->FoundDecl, Method); 6681 TheCall->setArg(0, Object); 6682 6683 6684 // Check the argument types. 6685 for (unsigned i = 0; i != NumArgsToCheck; i++) { 6686 Expr *Arg; 6687 if (i < NumArgs) { 6688 Arg = Args[i]; 6689 6690 // Pass the argument. 6691 6692 OwningExprResult InputInit 6693 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 6694 Method->getParamDecl(i)), 6695 SourceLocation(), Owned(Arg)); 6696 6697 IsError |= InputInit.isInvalid(); 6698 Arg = InputInit.takeAs<Expr>(); 6699 } else { 6700 OwningExprResult DefArg 6701 = BuildCXXDefaultArgExpr(LParenLoc, Method, Method->getParamDecl(i)); 6702 if (DefArg.isInvalid()) { 6703 IsError = true; 6704 break; 6705 } 6706 6707 Arg = DefArg.takeAs<Expr>(); 6708 } 6709 6710 TheCall->setArg(i + 1, Arg); 6711 } 6712 6713 // If this is a variadic call, handle args passed through "...". 6714 if (Proto->isVariadic()) { 6715 // Promote the arguments (C99 6.5.2.2p7). 6716 for (unsigned i = NumArgsInProto; i != NumArgs; i++) { 6717 Expr *Arg = Args[i]; 6718 IsError |= DefaultVariadicArgumentPromotion(Arg, VariadicMethod); 6719 TheCall->setArg(i + 1, Arg); 6720 } 6721 } 6722 6723 if (IsError) return true; 6724 6725 if (CheckFunctionCall(Method, TheCall.get())) 6726 return true; 6727 6728 return MaybeBindToTemporary(TheCall.release()).result(); 6729} 6730 6731/// BuildOverloadedArrowExpr - Build a call to an overloaded @c operator-> 6732/// (if one exists), where @c Base is an expression of class type and 6733/// @c Member is the name of the member we're trying to find. 6734Sema::OwningExprResult 6735Sema::BuildOverloadedArrowExpr(Scope *S, ExprArg BaseIn, SourceLocation OpLoc) { 6736 Expr *Base = static_cast<Expr *>(BaseIn.get()); 6737 assert(Base->getType()->isRecordType() && "left-hand side must have class type"); 6738 6739 SourceLocation Loc = Base->getExprLoc(); 6740 6741 // C++ [over.ref]p1: 6742 // 6743 // [...] An expression x->m is interpreted as (x.operator->())->m 6744 // for a class object x of type T if T::operator->() exists and if 6745 // the operator is selected as the best match function by the 6746 // overload resolution mechanism (13.3). 6747 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Arrow); 6748 OverloadCandidateSet CandidateSet(Loc); 6749 const RecordType *BaseRecord = Base->getType()->getAs<RecordType>(); 6750 6751 if (RequireCompleteType(Loc, Base->getType(), 6752 PDiag(diag::err_typecheck_incomplete_tag) 6753 << Base->getSourceRange())) 6754 return ExprError(); 6755 6756 LookupResult R(*this, OpName, OpLoc, LookupOrdinaryName); 6757 LookupQualifiedName(R, BaseRecord->getDecl()); 6758 R.suppressDiagnostics(); 6759 6760 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 6761 Oper != OperEnd; ++Oper) { 6762 AddMethodCandidate(Oper.getPair(), Base->getType(), 0, 0, CandidateSet, 6763 /*SuppressUserConversions=*/false); 6764 } 6765 6766 // Perform overload resolution. 6767 OverloadCandidateSet::iterator Best; 6768 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 6769 case OR_Success: 6770 // Overload resolution succeeded; we'll build the call below. 6771 break; 6772 6773 case OR_No_Viable_Function: 6774 if (CandidateSet.empty()) 6775 Diag(OpLoc, diag::err_typecheck_member_reference_arrow) 6776 << Base->getType() << Base->getSourceRange(); 6777 else 6778 Diag(OpLoc, diag::err_ovl_no_viable_oper) 6779 << "operator->" << Base->getSourceRange(); 6780 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, &Base, 1); 6781 return ExprError(); 6782 6783 case OR_Ambiguous: 6784 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 6785 << "->" << Base->getSourceRange(); 6786 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, &Base, 1); 6787 return ExprError(); 6788 6789 case OR_Deleted: 6790 Diag(OpLoc, diag::err_ovl_deleted_oper) 6791 << Best->Function->isDeleted() 6792 << "->" << Base->getSourceRange(); 6793 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, &Base, 1); 6794 return ExprError(); 6795 } 6796 6797 CheckMemberOperatorAccess(OpLoc, Base, 0, Best->FoundDecl); 6798 6799 // Convert the object parameter. 6800 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 6801 if (PerformObjectArgumentInitialization(Base, /*Qualifier=*/0, 6802 Best->FoundDecl, Method)) 6803 return ExprError(); 6804 6805 // No concerns about early exits now. 6806 BaseIn.release(); 6807 6808 // Build the operator call. 6809 Expr *FnExpr = new (Context) DeclRefExpr(Method, Method->getType(), 6810 SourceLocation()); 6811 UsualUnaryConversions(FnExpr); 6812 6813 QualType ResultTy = Method->getResultType().getNonReferenceType(); 6814 ExprOwningPtr<CXXOperatorCallExpr> 6815 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Arrow, FnExpr, 6816 &Base, 1, ResultTy, OpLoc)); 6817 6818 if (CheckCallReturnType(Method->getResultType(), OpLoc, TheCall.get(), 6819 Method)) 6820 return ExprError(); 6821 return move(TheCall); 6822} 6823 6824/// FixOverloadedFunctionReference - E is an expression that refers to 6825/// a C++ overloaded function (possibly with some parentheses and 6826/// perhaps a '&' around it). We have resolved the overloaded function 6827/// to the function declaration Fn, so patch up the expression E to 6828/// refer (possibly indirectly) to Fn. Returns the new expr. 6829Expr *Sema::FixOverloadedFunctionReference(Expr *E, DeclAccessPair Found, 6830 FunctionDecl *Fn) { 6831 if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) { 6832 Expr *SubExpr = FixOverloadedFunctionReference(PE->getSubExpr(), 6833 Found, Fn); 6834 if (SubExpr == PE->getSubExpr()) 6835 return PE->Retain(); 6836 6837 return new (Context) ParenExpr(PE->getLParen(), PE->getRParen(), SubExpr); 6838 } 6839 6840 if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) { 6841 Expr *SubExpr = FixOverloadedFunctionReference(ICE->getSubExpr(), 6842 Found, Fn); 6843 assert(Context.hasSameType(ICE->getSubExpr()->getType(), 6844 SubExpr->getType()) && 6845 "Implicit cast type cannot be determined from overload"); 6846 if (SubExpr == ICE->getSubExpr()) 6847 return ICE->Retain(); 6848 6849 return new (Context) ImplicitCastExpr(ICE->getType(), 6850 ICE->getCastKind(), 6851 SubExpr, 6852 ICE->isLvalueCast()); 6853 } 6854 6855 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(E)) { 6856 assert(UnOp->getOpcode() == UnaryOperator::AddrOf && 6857 "Can only take the address of an overloaded function"); 6858 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 6859 if (Method->isStatic()) { 6860 // Do nothing: static member functions aren't any different 6861 // from non-member functions. 6862 } else { 6863 // Fix the sub expression, which really has to be an 6864 // UnresolvedLookupExpr holding an overloaded member function 6865 // or template. 6866 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(), 6867 Found, Fn); 6868 if (SubExpr == UnOp->getSubExpr()) 6869 return UnOp->Retain(); 6870 6871 assert(isa<DeclRefExpr>(SubExpr) 6872 && "fixed to something other than a decl ref"); 6873 assert(cast<DeclRefExpr>(SubExpr)->getQualifier() 6874 && "fixed to a member ref with no nested name qualifier"); 6875 6876 // We have taken the address of a pointer to member 6877 // function. Perform the computation here so that we get the 6878 // appropriate pointer to member type. 6879 QualType ClassType 6880 = Context.getTypeDeclType(cast<RecordDecl>(Method->getDeclContext())); 6881 QualType MemPtrType 6882 = Context.getMemberPointerType(Fn->getType(), ClassType.getTypePtr()); 6883 6884 return new (Context) UnaryOperator(SubExpr, UnaryOperator::AddrOf, 6885 MemPtrType, UnOp->getOperatorLoc()); 6886 } 6887 } 6888 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(), 6889 Found, Fn); 6890 if (SubExpr == UnOp->getSubExpr()) 6891 return UnOp->Retain(); 6892 6893 return new (Context) UnaryOperator(SubExpr, UnaryOperator::AddrOf, 6894 Context.getPointerType(SubExpr->getType()), 6895 UnOp->getOperatorLoc()); 6896 } 6897 6898 if (UnresolvedLookupExpr *ULE = dyn_cast<UnresolvedLookupExpr>(E)) { 6899 // FIXME: avoid copy. 6900 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 6901 if (ULE->hasExplicitTemplateArgs()) { 6902 ULE->copyTemplateArgumentsInto(TemplateArgsBuffer); 6903 TemplateArgs = &TemplateArgsBuffer; 6904 } 6905 6906 return DeclRefExpr::Create(Context, 6907 ULE->getQualifier(), 6908 ULE->getQualifierRange(), 6909 Fn, 6910 ULE->getNameLoc(), 6911 Fn->getType(), 6912 TemplateArgs); 6913 } 6914 6915 if (UnresolvedMemberExpr *MemExpr = dyn_cast<UnresolvedMemberExpr>(E)) { 6916 // FIXME: avoid copy. 6917 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 6918 if (MemExpr->hasExplicitTemplateArgs()) { 6919 MemExpr->copyTemplateArgumentsInto(TemplateArgsBuffer); 6920 TemplateArgs = &TemplateArgsBuffer; 6921 } 6922 6923 Expr *Base; 6924 6925 // If we're filling in 6926 if (MemExpr->isImplicitAccess()) { 6927 if (cast<CXXMethodDecl>(Fn)->isStatic()) { 6928 return DeclRefExpr::Create(Context, 6929 MemExpr->getQualifier(), 6930 MemExpr->getQualifierRange(), 6931 Fn, 6932 MemExpr->getMemberLoc(), 6933 Fn->getType(), 6934 TemplateArgs); 6935 } else { 6936 SourceLocation Loc = MemExpr->getMemberLoc(); 6937 if (MemExpr->getQualifier()) 6938 Loc = MemExpr->getQualifierRange().getBegin(); 6939 Base = new (Context) CXXThisExpr(Loc, 6940 MemExpr->getBaseType(), 6941 /*isImplicit=*/true); 6942 } 6943 } else 6944 Base = MemExpr->getBase()->Retain(); 6945 6946 return MemberExpr::Create(Context, Base, 6947 MemExpr->isArrow(), 6948 MemExpr->getQualifier(), 6949 MemExpr->getQualifierRange(), 6950 Fn, 6951 Found, 6952 MemExpr->getMemberLoc(), 6953 TemplateArgs, 6954 Fn->getType()); 6955 } 6956 6957 assert(false && "Invalid reference to overloaded function"); 6958 return E->Retain(); 6959} 6960 6961Sema::OwningExprResult Sema::FixOverloadedFunctionReference(OwningExprResult E, 6962 DeclAccessPair Found, 6963 FunctionDecl *Fn) { 6964 return Owned(FixOverloadedFunctionReference((Expr *)E.get(), Found, Fn)); 6965} 6966 6967} // end namespace clang 6968