SemaOverload.cpp revision 0c525edf14d4cf5aaf8f6954433c0476d0bc6a65
1//===--- SemaOverload.cpp - C++ Overloading ---------------------*- C++ -*-===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This file provides Sema routines for C++ overloading. 11// 12//===----------------------------------------------------------------------===// 13 14#include "Sema.h" 15#include "Lookup.h" 16#include "SemaInit.h" 17#include "clang/Basic/Diagnostic.h" 18#include "clang/Lex/Preprocessor.h" 19#include "clang/AST/ASTContext.h" 20#include "clang/AST/CXXInheritance.h" 21#include "clang/AST/Expr.h" 22#include "clang/AST/ExprCXX.h" 23#include "clang/AST/TypeOrdering.h" 24#include "clang/Basic/PartialDiagnostic.h" 25#include "llvm/ADT/SmallPtrSet.h" 26#include "llvm/ADT/STLExtras.h" 27#include <algorithm> 28 29namespace clang { 30 31/// GetConversionCategory - Retrieve the implicit conversion 32/// category corresponding to the given implicit conversion kind. 33ImplicitConversionCategory 34GetConversionCategory(ImplicitConversionKind Kind) { 35 static const ImplicitConversionCategory 36 Category[(int)ICK_Num_Conversion_Kinds] = { 37 ICC_Identity, 38 ICC_Lvalue_Transformation, 39 ICC_Lvalue_Transformation, 40 ICC_Lvalue_Transformation, 41 ICC_Identity, 42 ICC_Qualification_Adjustment, 43 ICC_Promotion, 44 ICC_Promotion, 45 ICC_Promotion, 46 ICC_Conversion, 47 ICC_Conversion, 48 ICC_Conversion, 49 ICC_Conversion, 50 ICC_Conversion, 51 ICC_Conversion, 52 ICC_Conversion, 53 ICC_Conversion, 54 ICC_Conversion, 55 ICC_Conversion 56 }; 57 return Category[(int)Kind]; 58} 59 60/// GetConversionRank - Retrieve the implicit conversion rank 61/// corresponding to the given implicit conversion kind. 62ImplicitConversionRank GetConversionRank(ImplicitConversionKind Kind) { 63 static const ImplicitConversionRank 64 Rank[(int)ICK_Num_Conversion_Kinds] = { 65 ICR_Exact_Match, 66 ICR_Exact_Match, 67 ICR_Exact_Match, 68 ICR_Exact_Match, 69 ICR_Exact_Match, 70 ICR_Exact_Match, 71 ICR_Promotion, 72 ICR_Promotion, 73 ICR_Promotion, 74 ICR_Conversion, 75 ICR_Conversion, 76 ICR_Conversion, 77 ICR_Conversion, 78 ICR_Conversion, 79 ICR_Conversion, 80 ICR_Conversion, 81 ICR_Conversion, 82 ICR_Conversion, 83 ICR_Complex_Real_Conversion 84 }; 85 return Rank[(int)Kind]; 86} 87 88/// GetImplicitConversionName - Return the name of this kind of 89/// implicit conversion. 90const char* GetImplicitConversionName(ImplicitConversionKind Kind) { 91 static const char* const Name[(int)ICK_Num_Conversion_Kinds] = { 92 "No conversion", 93 "Lvalue-to-rvalue", 94 "Array-to-pointer", 95 "Function-to-pointer", 96 "Noreturn adjustment", 97 "Qualification", 98 "Integral promotion", 99 "Floating point promotion", 100 "Complex promotion", 101 "Integral conversion", 102 "Floating conversion", 103 "Complex conversion", 104 "Floating-integral conversion", 105 "Complex-real conversion", 106 "Pointer conversion", 107 "Pointer-to-member conversion", 108 "Boolean conversion", 109 "Compatible-types conversion", 110 "Derived-to-base conversion" 111 }; 112 return Name[Kind]; 113} 114 115/// StandardConversionSequence - Set the standard conversion 116/// sequence to the identity conversion. 117void StandardConversionSequence::setAsIdentityConversion() { 118 First = ICK_Identity; 119 Second = ICK_Identity; 120 Third = ICK_Identity; 121 DeprecatedStringLiteralToCharPtr = false; 122 ReferenceBinding = false; 123 DirectBinding = false; 124 RRefBinding = false; 125 CopyConstructor = 0; 126} 127 128/// getRank - Retrieve the rank of this standard conversion sequence 129/// (C++ 13.3.3.1.1p3). The rank is the largest rank of each of the 130/// implicit conversions. 131ImplicitConversionRank StandardConversionSequence::getRank() const { 132 ImplicitConversionRank Rank = ICR_Exact_Match; 133 if (GetConversionRank(First) > Rank) 134 Rank = GetConversionRank(First); 135 if (GetConversionRank(Second) > Rank) 136 Rank = GetConversionRank(Second); 137 if (GetConversionRank(Third) > Rank) 138 Rank = GetConversionRank(Third); 139 return Rank; 140} 141 142/// isPointerConversionToBool - Determines whether this conversion is 143/// a conversion of a pointer or pointer-to-member to bool. This is 144/// used as part of the ranking of standard conversion sequences 145/// (C++ 13.3.3.2p4). 146bool StandardConversionSequence::isPointerConversionToBool() const { 147 // Note that FromType has not necessarily been transformed by the 148 // array-to-pointer or function-to-pointer implicit conversions, so 149 // check for their presence as well as checking whether FromType is 150 // a pointer. 151 if (getToType(1)->isBooleanType() && 152 (getFromType()->isPointerType() || getFromType()->isBlockPointerType() || 153 First == ICK_Array_To_Pointer || First == ICK_Function_To_Pointer)) 154 return true; 155 156 return false; 157} 158 159/// isPointerConversionToVoidPointer - Determines whether this 160/// conversion is a conversion of a pointer to a void pointer. This is 161/// used as part of the ranking of standard conversion sequences (C++ 162/// 13.3.3.2p4). 163bool 164StandardConversionSequence:: 165isPointerConversionToVoidPointer(ASTContext& Context) const { 166 QualType FromType = getFromType(); 167 QualType ToType = getToType(1); 168 169 // Note that FromType has not necessarily been transformed by the 170 // array-to-pointer implicit conversion, so check for its presence 171 // and redo the conversion to get a pointer. 172 if (First == ICK_Array_To_Pointer) 173 FromType = Context.getArrayDecayedType(FromType); 174 175 if (Second == ICK_Pointer_Conversion && FromType->isPointerType()) 176 if (const PointerType* ToPtrType = ToType->getAs<PointerType>()) 177 return ToPtrType->getPointeeType()->isVoidType(); 178 179 return false; 180} 181 182/// DebugPrint - Print this standard conversion sequence to standard 183/// error. Useful for debugging overloading issues. 184void StandardConversionSequence::DebugPrint() const { 185 llvm::raw_ostream &OS = llvm::errs(); 186 bool PrintedSomething = false; 187 if (First != ICK_Identity) { 188 OS << GetImplicitConversionName(First); 189 PrintedSomething = true; 190 } 191 192 if (Second != ICK_Identity) { 193 if (PrintedSomething) { 194 OS << " -> "; 195 } 196 OS << GetImplicitConversionName(Second); 197 198 if (CopyConstructor) { 199 OS << " (by copy constructor)"; 200 } else if (DirectBinding) { 201 OS << " (direct reference binding)"; 202 } else if (ReferenceBinding) { 203 OS << " (reference binding)"; 204 } 205 PrintedSomething = true; 206 } 207 208 if (Third != ICK_Identity) { 209 if (PrintedSomething) { 210 OS << " -> "; 211 } 212 OS << GetImplicitConversionName(Third); 213 PrintedSomething = true; 214 } 215 216 if (!PrintedSomething) { 217 OS << "No conversions required"; 218 } 219} 220 221/// DebugPrint - Print this user-defined conversion sequence to standard 222/// error. Useful for debugging overloading issues. 223void UserDefinedConversionSequence::DebugPrint() const { 224 llvm::raw_ostream &OS = llvm::errs(); 225 if (Before.First || Before.Second || Before.Third) { 226 Before.DebugPrint(); 227 OS << " -> "; 228 } 229 OS << "'" << ConversionFunction->getNameAsString() << "'"; 230 if (After.First || After.Second || After.Third) { 231 OS << " -> "; 232 After.DebugPrint(); 233 } 234} 235 236/// DebugPrint - Print this implicit conversion sequence to standard 237/// error. Useful for debugging overloading issues. 238void ImplicitConversionSequence::DebugPrint() const { 239 llvm::raw_ostream &OS = llvm::errs(); 240 switch (ConversionKind) { 241 case StandardConversion: 242 OS << "Standard conversion: "; 243 Standard.DebugPrint(); 244 break; 245 case UserDefinedConversion: 246 OS << "User-defined conversion: "; 247 UserDefined.DebugPrint(); 248 break; 249 case EllipsisConversion: 250 OS << "Ellipsis conversion"; 251 break; 252 case AmbiguousConversion: 253 OS << "Ambiguous conversion"; 254 break; 255 case BadConversion: 256 OS << "Bad conversion"; 257 break; 258 } 259 260 OS << "\n"; 261} 262 263void AmbiguousConversionSequence::construct() { 264 new (&conversions()) ConversionSet(); 265} 266 267void AmbiguousConversionSequence::destruct() { 268 conversions().~ConversionSet(); 269} 270 271void 272AmbiguousConversionSequence::copyFrom(const AmbiguousConversionSequence &O) { 273 FromTypePtr = O.FromTypePtr; 274 ToTypePtr = O.ToTypePtr; 275 new (&conversions()) ConversionSet(O.conversions()); 276} 277 278 279// IsOverload - Determine whether the given New declaration is an 280// overload of the declarations in Old. This routine returns false if 281// New and Old cannot be overloaded, e.g., if New has the same 282// signature as some function in Old (C++ 1.3.10) or if the Old 283// declarations aren't functions (or function templates) at all. When 284// it does return false, MatchedDecl will point to the decl that New 285// cannot be overloaded with. This decl may be a UsingShadowDecl on 286// top of the underlying declaration. 287// 288// Example: Given the following input: 289// 290// void f(int, float); // #1 291// void f(int, int); // #2 292// int f(int, int); // #3 293// 294// When we process #1, there is no previous declaration of "f", 295// so IsOverload will not be used. 296// 297// When we process #2, Old contains only the FunctionDecl for #1. By 298// comparing the parameter types, we see that #1 and #2 are overloaded 299// (since they have different signatures), so this routine returns 300// false; MatchedDecl is unchanged. 301// 302// When we process #3, Old is an overload set containing #1 and #2. We 303// compare the signatures of #3 to #1 (they're overloaded, so we do 304// nothing) and then #3 to #2. Since the signatures of #3 and #2 are 305// identical (return types of functions are not part of the 306// signature), IsOverload returns false and MatchedDecl will be set to 307// point to the FunctionDecl for #2. 308Sema::OverloadKind 309Sema::CheckOverload(FunctionDecl *New, const LookupResult &Old, 310 NamedDecl *&Match) { 311 for (LookupResult::iterator I = Old.begin(), E = Old.end(); 312 I != E; ++I) { 313 NamedDecl *OldD = (*I)->getUnderlyingDecl(); 314 if (FunctionTemplateDecl *OldT = dyn_cast<FunctionTemplateDecl>(OldD)) { 315 if (!IsOverload(New, OldT->getTemplatedDecl())) { 316 Match = *I; 317 return Ovl_Match; 318 } 319 } else if (FunctionDecl *OldF = dyn_cast<FunctionDecl>(OldD)) { 320 if (!IsOverload(New, OldF)) { 321 Match = *I; 322 return Ovl_Match; 323 } 324 } else if (isa<UsingDecl>(OldD) || isa<TagDecl>(OldD)) { 325 // We can overload with these, which can show up when doing 326 // redeclaration checks for UsingDecls. 327 assert(Old.getLookupKind() == LookupUsingDeclName); 328 } else if (isa<UnresolvedUsingValueDecl>(OldD)) { 329 // Optimistically assume that an unresolved using decl will 330 // overload; if it doesn't, we'll have to diagnose during 331 // template instantiation. 332 } else { 333 // (C++ 13p1): 334 // Only function declarations can be overloaded; object and type 335 // declarations cannot be overloaded. 336 Match = *I; 337 return Ovl_NonFunction; 338 } 339 } 340 341 return Ovl_Overload; 342} 343 344bool Sema::IsOverload(FunctionDecl *New, FunctionDecl *Old) { 345 FunctionTemplateDecl *OldTemplate = Old->getDescribedFunctionTemplate(); 346 FunctionTemplateDecl *NewTemplate = New->getDescribedFunctionTemplate(); 347 348 // C++ [temp.fct]p2: 349 // A function template can be overloaded with other function templates 350 // and with normal (non-template) functions. 351 if ((OldTemplate == 0) != (NewTemplate == 0)) 352 return true; 353 354 // Is the function New an overload of the function Old? 355 QualType OldQType = Context.getCanonicalType(Old->getType()); 356 QualType NewQType = Context.getCanonicalType(New->getType()); 357 358 // Compare the signatures (C++ 1.3.10) of the two functions to 359 // determine whether they are overloads. If we find any mismatch 360 // in the signature, they are overloads. 361 362 // If either of these functions is a K&R-style function (no 363 // prototype), then we consider them to have matching signatures. 364 if (isa<FunctionNoProtoType>(OldQType.getTypePtr()) || 365 isa<FunctionNoProtoType>(NewQType.getTypePtr())) 366 return false; 367 368 FunctionProtoType* OldType = cast<FunctionProtoType>(OldQType); 369 FunctionProtoType* NewType = cast<FunctionProtoType>(NewQType); 370 371 // The signature of a function includes the types of its 372 // parameters (C++ 1.3.10), which includes the presence or absence 373 // of the ellipsis; see C++ DR 357). 374 if (OldQType != NewQType && 375 (OldType->getNumArgs() != NewType->getNumArgs() || 376 OldType->isVariadic() != NewType->isVariadic() || 377 !std::equal(OldType->arg_type_begin(), OldType->arg_type_end(), 378 NewType->arg_type_begin()))) 379 return true; 380 381 // C++ [temp.over.link]p4: 382 // The signature of a function template consists of its function 383 // signature, its return type and its template parameter list. The names 384 // of the template parameters are significant only for establishing the 385 // relationship between the template parameters and the rest of the 386 // signature. 387 // 388 // We check the return type and template parameter lists for function 389 // templates first; the remaining checks follow. 390 if (NewTemplate && 391 (!TemplateParameterListsAreEqual(NewTemplate->getTemplateParameters(), 392 OldTemplate->getTemplateParameters(), 393 false, TPL_TemplateMatch) || 394 OldType->getResultType() != NewType->getResultType())) 395 return true; 396 397 // If the function is a class member, its signature includes the 398 // cv-qualifiers (if any) on the function itself. 399 // 400 // As part of this, also check whether one of the member functions 401 // is static, in which case they are not overloads (C++ 402 // 13.1p2). While not part of the definition of the signature, 403 // this check is important to determine whether these functions 404 // can be overloaded. 405 CXXMethodDecl* OldMethod = dyn_cast<CXXMethodDecl>(Old); 406 CXXMethodDecl* NewMethod = dyn_cast<CXXMethodDecl>(New); 407 if (OldMethod && NewMethod && 408 !OldMethod->isStatic() && !NewMethod->isStatic() && 409 OldMethod->getTypeQualifiers() != NewMethod->getTypeQualifiers()) 410 return true; 411 412 // The signatures match; this is not an overload. 413 return false; 414} 415 416/// TryImplicitConversion - Attempt to perform an implicit conversion 417/// from the given expression (Expr) to the given type (ToType). This 418/// function returns an implicit conversion sequence that can be used 419/// to perform the initialization. Given 420/// 421/// void f(float f); 422/// void g(int i) { f(i); } 423/// 424/// this routine would produce an implicit conversion sequence to 425/// describe the initialization of f from i, which will be a standard 426/// conversion sequence containing an lvalue-to-rvalue conversion (C++ 427/// 4.1) followed by a floating-integral conversion (C++ 4.9). 428// 429/// Note that this routine only determines how the conversion can be 430/// performed; it does not actually perform the conversion. As such, 431/// it will not produce any diagnostics if no conversion is available, 432/// but will instead return an implicit conversion sequence of kind 433/// "BadConversion". 434/// 435/// If @p SuppressUserConversions, then user-defined conversions are 436/// not permitted. 437/// If @p AllowExplicit, then explicit user-defined conversions are 438/// permitted. 439/// If @p ForceRValue, then overloading is performed as if From was an rvalue, 440/// no matter its actual lvalueness. 441/// If @p UserCast, the implicit conversion is being done for a user-specified 442/// cast. 443ImplicitConversionSequence 444Sema::TryImplicitConversion(Expr* From, QualType ToType, 445 bool SuppressUserConversions, 446 bool AllowExplicit, bool ForceRValue, 447 bool InOverloadResolution, 448 bool UserCast) { 449 ImplicitConversionSequence ICS; 450 if (IsStandardConversion(From, ToType, InOverloadResolution, ICS.Standard)) { 451 ICS.setStandard(); 452 return ICS; 453 } 454 455 if (!getLangOptions().CPlusPlus) { 456 ICS.setBad(BadConversionSequence::no_conversion, From, ToType); 457 return ICS; 458 } 459 460 OverloadCandidateSet Conversions(From->getExprLoc()); 461 OverloadingResult UserDefResult 462 = IsUserDefinedConversion(From, ToType, ICS.UserDefined, Conversions, 463 !SuppressUserConversions, AllowExplicit, 464 ForceRValue, UserCast); 465 466 if (UserDefResult == OR_Success) { 467 ICS.setUserDefined(); 468 // C++ [over.ics.user]p4: 469 // A conversion of an expression of class type to the same class 470 // type is given Exact Match rank, and a conversion of an 471 // expression of class type to a base class of that type is 472 // given Conversion rank, in spite of the fact that a copy 473 // constructor (i.e., a user-defined conversion function) is 474 // called for those cases. 475 if (CXXConstructorDecl *Constructor 476 = dyn_cast<CXXConstructorDecl>(ICS.UserDefined.ConversionFunction)) { 477 QualType FromCanon 478 = Context.getCanonicalType(From->getType().getUnqualifiedType()); 479 QualType ToCanon = Context.getCanonicalType(ToType).getUnqualifiedType(); 480 if (Constructor->isCopyConstructor() && 481 (FromCanon == ToCanon || IsDerivedFrom(FromCanon, ToCanon))) { 482 // Turn this into a "standard" conversion sequence, so that it 483 // gets ranked with standard conversion sequences. 484 ICS.setStandard(); 485 ICS.Standard.setAsIdentityConversion(); 486 ICS.Standard.setFromType(From->getType()); 487 ICS.Standard.setAllToTypes(ToType); 488 ICS.Standard.CopyConstructor = Constructor; 489 if (ToCanon != FromCanon) 490 ICS.Standard.Second = ICK_Derived_To_Base; 491 } 492 } 493 494 // C++ [over.best.ics]p4: 495 // However, when considering the argument of a user-defined 496 // conversion function that is a candidate by 13.3.1.3 when 497 // invoked for the copying of the temporary in the second step 498 // of a class copy-initialization, or by 13.3.1.4, 13.3.1.5, or 499 // 13.3.1.6 in all cases, only standard conversion sequences and 500 // ellipsis conversion sequences are allowed. 501 if (SuppressUserConversions && ICS.isUserDefined()) { 502 ICS.setBad(BadConversionSequence::suppressed_user, From, ToType); 503 } 504 } else if (UserDefResult == OR_Ambiguous && !SuppressUserConversions) { 505 ICS.setAmbiguous(); 506 ICS.Ambiguous.setFromType(From->getType()); 507 ICS.Ambiguous.setToType(ToType); 508 for (OverloadCandidateSet::iterator Cand = Conversions.begin(); 509 Cand != Conversions.end(); ++Cand) 510 if (Cand->Viable) 511 ICS.Ambiguous.addConversion(Cand->Function); 512 } else { 513 ICS.setBad(BadConversionSequence::no_conversion, From, ToType); 514 } 515 516 return ICS; 517} 518 519/// \brief Determine whether the conversion from FromType to ToType is a valid 520/// conversion that strips "noreturn" off the nested function type. 521static bool IsNoReturnConversion(ASTContext &Context, QualType FromType, 522 QualType ToType, QualType &ResultTy) { 523 if (Context.hasSameUnqualifiedType(FromType, ToType)) 524 return false; 525 526 // Strip the noreturn off the type we're converting from; noreturn can 527 // safely be removed. 528 FromType = Context.getNoReturnType(FromType, false); 529 if (!Context.hasSameUnqualifiedType(FromType, ToType)) 530 return false; 531 532 ResultTy = FromType; 533 return true; 534} 535 536/// IsStandardConversion - Determines whether there is a standard 537/// conversion sequence (C++ [conv], C++ [over.ics.scs]) from the 538/// expression From to the type ToType. Standard conversion sequences 539/// only consider non-class types; for conversions that involve class 540/// types, use TryImplicitConversion. If a conversion exists, SCS will 541/// contain the standard conversion sequence required to perform this 542/// conversion and this routine will return true. Otherwise, this 543/// routine will return false and the value of SCS is unspecified. 544bool 545Sema::IsStandardConversion(Expr* From, QualType ToType, 546 bool InOverloadResolution, 547 StandardConversionSequence &SCS) { 548 QualType FromType = From->getType(); 549 550 // Standard conversions (C++ [conv]) 551 SCS.setAsIdentityConversion(); 552 SCS.DeprecatedStringLiteralToCharPtr = false; 553 SCS.IncompatibleObjC = false; 554 SCS.setFromType(FromType); 555 SCS.CopyConstructor = 0; 556 557 // There are no standard conversions for class types in C++, so 558 // abort early. When overloading in C, however, we do permit 559 if (FromType->isRecordType() || ToType->isRecordType()) { 560 if (getLangOptions().CPlusPlus) 561 return false; 562 563 // When we're overloading in C, we allow, as standard conversions, 564 } 565 566 // The first conversion can be an lvalue-to-rvalue conversion, 567 // array-to-pointer conversion, or function-to-pointer conversion 568 // (C++ 4p1). 569 570 DeclAccessPair AccessPair; 571 572 // Lvalue-to-rvalue conversion (C++ 4.1): 573 // An lvalue (3.10) of a non-function, non-array type T can be 574 // converted to an rvalue. 575 Expr::isLvalueResult argIsLvalue = From->isLvalue(Context); 576 if (argIsLvalue == Expr::LV_Valid && 577 !FromType->isFunctionType() && !FromType->isArrayType() && 578 Context.getCanonicalType(FromType) != Context.OverloadTy) { 579 SCS.First = ICK_Lvalue_To_Rvalue; 580 581 // If T is a non-class type, the type of the rvalue is the 582 // cv-unqualified version of T. Otherwise, the type of the rvalue 583 // is T (C++ 4.1p1). C++ can't get here with class types; in C, we 584 // just strip the qualifiers because they don't matter. 585 FromType = FromType.getUnqualifiedType(); 586 } else if (FromType->isArrayType()) { 587 // Array-to-pointer conversion (C++ 4.2) 588 SCS.First = ICK_Array_To_Pointer; 589 590 // An lvalue or rvalue of type "array of N T" or "array of unknown 591 // bound of T" can be converted to an rvalue of type "pointer to 592 // T" (C++ 4.2p1). 593 FromType = Context.getArrayDecayedType(FromType); 594 595 if (IsStringLiteralToNonConstPointerConversion(From, ToType)) { 596 // This conversion is deprecated. (C++ D.4). 597 SCS.DeprecatedStringLiteralToCharPtr = true; 598 599 // For the purpose of ranking in overload resolution 600 // (13.3.3.1.1), this conversion is considered an 601 // array-to-pointer conversion followed by a qualification 602 // conversion (4.4). (C++ 4.2p2) 603 SCS.Second = ICK_Identity; 604 SCS.Third = ICK_Qualification; 605 SCS.setAllToTypes(FromType); 606 return true; 607 } 608 } else if (FromType->isFunctionType() && argIsLvalue == Expr::LV_Valid) { 609 // Function-to-pointer conversion (C++ 4.3). 610 SCS.First = ICK_Function_To_Pointer; 611 612 // An lvalue of function type T can be converted to an rvalue of 613 // type "pointer to T." The result is a pointer to the 614 // function. (C++ 4.3p1). 615 FromType = Context.getPointerType(FromType); 616 } else if (FunctionDecl *Fn 617 = ResolveAddressOfOverloadedFunction(From, ToType, false, 618 AccessPair)) { 619 // Address of overloaded function (C++ [over.over]). 620 SCS.First = ICK_Function_To_Pointer; 621 622 // We were able to resolve the address of the overloaded function, 623 // so we can convert to the type of that function. 624 FromType = Fn->getType(); 625 if (ToType->isLValueReferenceType()) 626 FromType = Context.getLValueReferenceType(FromType); 627 else if (ToType->isRValueReferenceType()) 628 FromType = Context.getRValueReferenceType(FromType); 629 else if (ToType->isMemberPointerType()) { 630 // Resolve address only succeeds if both sides are member pointers, 631 // but it doesn't have to be the same class. See DR 247. 632 // Note that this means that the type of &Derived::fn can be 633 // Ret (Base::*)(Args) if the fn overload actually found is from the 634 // base class, even if it was brought into the derived class via a 635 // using declaration. The standard isn't clear on this issue at all. 636 CXXMethodDecl *M = cast<CXXMethodDecl>(Fn); 637 FromType = Context.getMemberPointerType(FromType, 638 Context.getTypeDeclType(M->getParent()).getTypePtr()); 639 } else 640 FromType = Context.getPointerType(FromType); 641 } else { 642 // We don't require any conversions for the first step. 643 SCS.First = ICK_Identity; 644 } 645 SCS.setToType(0, FromType); 646 647 // The second conversion can be an integral promotion, floating 648 // point promotion, integral conversion, floating point conversion, 649 // floating-integral conversion, pointer conversion, 650 // pointer-to-member conversion, or boolean conversion (C++ 4p1). 651 // For overloading in C, this can also be a "compatible-type" 652 // conversion. 653 bool IncompatibleObjC = false; 654 if (Context.hasSameUnqualifiedType(FromType, ToType)) { 655 // The unqualified versions of the types are the same: there's no 656 // conversion to do. 657 SCS.Second = ICK_Identity; 658 } else if (IsIntegralPromotion(From, FromType, ToType)) { 659 // Integral promotion (C++ 4.5). 660 SCS.Second = ICK_Integral_Promotion; 661 FromType = ToType.getUnqualifiedType(); 662 } else if (IsFloatingPointPromotion(FromType, ToType)) { 663 // Floating point promotion (C++ 4.6). 664 SCS.Second = ICK_Floating_Promotion; 665 FromType = ToType.getUnqualifiedType(); 666 } else if (IsComplexPromotion(FromType, ToType)) { 667 // Complex promotion (Clang extension) 668 SCS.Second = ICK_Complex_Promotion; 669 FromType = ToType.getUnqualifiedType(); 670 } else if ((FromType->isIntegralType() || FromType->isEnumeralType()) && 671 (ToType->isIntegralType() && !ToType->isEnumeralType())) { 672 // Integral conversions (C++ 4.7). 673 SCS.Second = ICK_Integral_Conversion; 674 FromType = ToType.getUnqualifiedType(); 675 } else if (FromType->isComplexType() && ToType->isComplexType()) { 676 // Complex conversions (C99 6.3.1.6) 677 SCS.Second = ICK_Complex_Conversion; 678 FromType = ToType.getUnqualifiedType(); 679 } else if ((FromType->isComplexType() && ToType->isArithmeticType()) || 680 (ToType->isComplexType() && FromType->isArithmeticType())) { 681 // Complex-real conversions (C99 6.3.1.7) 682 SCS.Second = ICK_Complex_Real; 683 FromType = ToType.getUnqualifiedType(); 684 } else if (FromType->isFloatingType() && ToType->isFloatingType()) { 685 // Floating point conversions (C++ 4.8). 686 SCS.Second = ICK_Floating_Conversion; 687 FromType = ToType.getUnqualifiedType(); 688 } else if ((FromType->isFloatingType() && 689 ToType->isIntegralType() && (!ToType->isBooleanType() && 690 !ToType->isEnumeralType())) || 691 ((FromType->isIntegralType() || FromType->isEnumeralType()) && 692 ToType->isFloatingType())) { 693 // Floating-integral conversions (C++ 4.9). 694 SCS.Second = ICK_Floating_Integral; 695 FromType = ToType.getUnqualifiedType(); 696 } else if (IsPointerConversion(From, FromType, ToType, InOverloadResolution, 697 FromType, IncompatibleObjC)) { 698 // Pointer conversions (C++ 4.10). 699 SCS.Second = ICK_Pointer_Conversion; 700 SCS.IncompatibleObjC = IncompatibleObjC; 701 } else if (IsMemberPointerConversion(From, FromType, ToType, 702 InOverloadResolution, FromType)) { 703 // Pointer to member conversions (4.11). 704 SCS.Second = ICK_Pointer_Member; 705 } else if (ToType->isBooleanType() && 706 (FromType->isArithmeticType() || 707 FromType->isEnumeralType() || 708 FromType->isAnyPointerType() || 709 FromType->isBlockPointerType() || 710 FromType->isMemberPointerType() || 711 FromType->isNullPtrType())) { 712 // Boolean conversions (C++ 4.12). 713 SCS.Second = ICK_Boolean_Conversion; 714 FromType = Context.BoolTy; 715 } else if (!getLangOptions().CPlusPlus && 716 Context.typesAreCompatible(ToType, FromType)) { 717 // Compatible conversions (Clang extension for C function overloading) 718 SCS.Second = ICK_Compatible_Conversion; 719 } else if (IsNoReturnConversion(Context, FromType, ToType, FromType)) { 720 // Treat a conversion that strips "noreturn" as an identity conversion. 721 SCS.Second = ICK_NoReturn_Adjustment; 722 } else { 723 // No second conversion required. 724 SCS.Second = ICK_Identity; 725 } 726 SCS.setToType(1, FromType); 727 728 QualType CanonFrom; 729 QualType CanonTo; 730 // The third conversion can be a qualification conversion (C++ 4p1). 731 if (IsQualificationConversion(FromType, ToType)) { 732 SCS.Third = ICK_Qualification; 733 FromType = ToType; 734 CanonFrom = Context.getCanonicalType(FromType); 735 CanonTo = Context.getCanonicalType(ToType); 736 } else { 737 // No conversion required 738 SCS.Third = ICK_Identity; 739 740 // C++ [over.best.ics]p6: 741 // [...] Any difference in top-level cv-qualification is 742 // subsumed by the initialization itself and does not constitute 743 // a conversion. [...] 744 CanonFrom = Context.getCanonicalType(FromType); 745 CanonTo = Context.getCanonicalType(ToType); 746 if (CanonFrom.getLocalUnqualifiedType() 747 == CanonTo.getLocalUnqualifiedType() && 748 CanonFrom.getLocalCVRQualifiers() != CanonTo.getLocalCVRQualifiers()) { 749 FromType = ToType; 750 CanonFrom = CanonTo; 751 } 752 } 753 SCS.setToType(2, FromType); 754 755 // If we have not converted the argument type to the parameter type, 756 // this is a bad conversion sequence. 757 if (CanonFrom != CanonTo) 758 return false; 759 760 return true; 761} 762 763/// IsIntegralPromotion - Determines whether the conversion from the 764/// expression From (whose potentially-adjusted type is FromType) to 765/// ToType is an integral promotion (C++ 4.5). If so, returns true and 766/// sets PromotedType to the promoted type. 767bool Sema::IsIntegralPromotion(Expr *From, QualType FromType, QualType ToType) { 768 const BuiltinType *To = ToType->getAs<BuiltinType>(); 769 // All integers are built-in. 770 if (!To) { 771 return false; 772 } 773 774 // An rvalue of type char, signed char, unsigned char, short int, or 775 // unsigned short int can be converted to an rvalue of type int if 776 // int can represent all the values of the source type; otherwise, 777 // the source rvalue can be converted to an rvalue of type unsigned 778 // int (C++ 4.5p1). 779 if (FromType->isPromotableIntegerType() && !FromType->isBooleanType() && 780 !FromType->isEnumeralType()) { 781 if (// We can promote any signed, promotable integer type to an int 782 (FromType->isSignedIntegerType() || 783 // We can promote any unsigned integer type whose size is 784 // less than int to an int. 785 (!FromType->isSignedIntegerType() && 786 Context.getTypeSize(FromType) < Context.getTypeSize(ToType)))) { 787 return To->getKind() == BuiltinType::Int; 788 } 789 790 return To->getKind() == BuiltinType::UInt; 791 } 792 793 // An rvalue of type wchar_t (3.9.1) or an enumeration type (7.2) 794 // can be converted to an rvalue of the first of the following types 795 // that can represent all the values of its underlying type: int, 796 // unsigned int, long, or unsigned long (C++ 4.5p2). 797 798 // We pre-calculate the promotion type for enum types. 799 if (const EnumType *FromEnumType = FromType->getAs<EnumType>()) 800 if (ToType->isIntegerType()) 801 return Context.hasSameUnqualifiedType(ToType, 802 FromEnumType->getDecl()->getPromotionType()); 803 804 if (FromType->isWideCharType() && ToType->isIntegerType()) { 805 // Determine whether the type we're converting from is signed or 806 // unsigned. 807 bool FromIsSigned; 808 uint64_t FromSize = Context.getTypeSize(FromType); 809 810 // FIXME: Is wchar_t signed or unsigned? We assume it's signed for now. 811 FromIsSigned = true; 812 813 // The types we'll try to promote to, in the appropriate 814 // order. Try each of these types. 815 QualType PromoteTypes[6] = { 816 Context.IntTy, Context.UnsignedIntTy, 817 Context.LongTy, Context.UnsignedLongTy , 818 Context.LongLongTy, Context.UnsignedLongLongTy 819 }; 820 for (int Idx = 0; Idx < 6; ++Idx) { 821 uint64_t ToSize = Context.getTypeSize(PromoteTypes[Idx]); 822 if (FromSize < ToSize || 823 (FromSize == ToSize && 824 FromIsSigned == PromoteTypes[Idx]->isSignedIntegerType())) { 825 // We found the type that we can promote to. If this is the 826 // type we wanted, we have a promotion. Otherwise, no 827 // promotion. 828 return Context.hasSameUnqualifiedType(ToType, PromoteTypes[Idx]); 829 } 830 } 831 } 832 833 // An rvalue for an integral bit-field (9.6) can be converted to an 834 // rvalue of type int if int can represent all the values of the 835 // bit-field; otherwise, it can be converted to unsigned int if 836 // unsigned int can represent all the values of the bit-field. If 837 // the bit-field is larger yet, no integral promotion applies to 838 // it. If the bit-field has an enumerated type, it is treated as any 839 // other value of that type for promotion purposes (C++ 4.5p3). 840 // FIXME: We should delay checking of bit-fields until we actually perform the 841 // conversion. 842 using llvm::APSInt; 843 if (From) 844 if (FieldDecl *MemberDecl = From->getBitField()) { 845 APSInt BitWidth; 846 if (FromType->isIntegralType() && !FromType->isEnumeralType() && 847 MemberDecl->getBitWidth()->isIntegerConstantExpr(BitWidth, Context)) { 848 APSInt ToSize(BitWidth.getBitWidth(), BitWidth.isUnsigned()); 849 ToSize = Context.getTypeSize(ToType); 850 851 // Are we promoting to an int from a bitfield that fits in an int? 852 if (BitWidth < ToSize || 853 (FromType->isSignedIntegerType() && BitWidth <= ToSize)) { 854 return To->getKind() == BuiltinType::Int; 855 } 856 857 // Are we promoting to an unsigned int from an unsigned bitfield 858 // that fits into an unsigned int? 859 if (FromType->isUnsignedIntegerType() && BitWidth <= ToSize) { 860 return To->getKind() == BuiltinType::UInt; 861 } 862 863 return false; 864 } 865 } 866 867 // An rvalue of type bool can be converted to an rvalue of type int, 868 // with false becoming zero and true becoming one (C++ 4.5p4). 869 if (FromType->isBooleanType() && To->getKind() == BuiltinType::Int) { 870 return true; 871 } 872 873 return false; 874} 875 876/// IsFloatingPointPromotion - Determines whether the conversion from 877/// FromType to ToType is a floating point promotion (C++ 4.6). If so, 878/// returns true and sets PromotedType to the promoted type. 879bool Sema::IsFloatingPointPromotion(QualType FromType, QualType ToType) { 880 /// An rvalue of type float can be converted to an rvalue of type 881 /// double. (C++ 4.6p1). 882 if (const BuiltinType *FromBuiltin = FromType->getAs<BuiltinType>()) 883 if (const BuiltinType *ToBuiltin = ToType->getAs<BuiltinType>()) { 884 if (FromBuiltin->getKind() == BuiltinType::Float && 885 ToBuiltin->getKind() == BuiltinType::Double) 886 return true; 887 888 // C99 6.3.1.5p1: 889 // When a float is promoted to double or long double, or a 890 // double is promoted to long double [...]. 891 if (!getLangOptions().CPlusPlus && 892 (FromBuiltin->getKind() == BuiltinType::Float || 893 FromBuiltin->getKind() == BuiltinType::Double) && 894 (ToBuiltin->getKind() == BuiltinType::LongDouble)) 895 return true; 896 } 897 898 return false; 899} 900 901/// \brief Determine if a conversion is a complex promotion. 902/// 903/// A complex promotion is defined as a complex -> complex conversion 904/// where the conversion between the underlying real types is a 905/// floating-point or integral promotion. 906bool Sema::IsComplexPromotion(QualType FromType, QualType ToType) { 907 const ComplexType *FromComplex = FromType->getAs<ComplexType>(); 908 if (!FromComplex) 909 return false; 910 911 const ComplexType *ToComplex = ToType->getAs<ComplexType>(); 912 if (!ToComplex) 913 return false; 914 915 return IsFloatingPointPromotion(FromComplex->getElementType(), 916 ToComplex->getElementType()) || 917 IsIntegralPromotion(0, FromComplex->getElementType(), 918 ToComplex->getElementType()); 919} 920 921/// BuildSimilarlyQualifiedPointerType - In a pointer conversion from 922/// the pointer type FromPtr to a pointer to type ToPointee, with the 923/// same type qualifiers as FromPtr has on its pointee type. ToType, 924/// if non-empty, will be a pointer to ToType that may or may not have 925/// the right set of qualifiers on its pointee. 926static QualType 927BuildSimilarlyQualifiedPointerType(const PointerType *FromPtr, 928 QualType ToPointee, QualType ToType, 929 ASTContext &Context) { 930 QualType CanonFromPointee = Context.getCanonicalType(FromPtr->getPointeeType()); 931 QualType CanonToPointee = Context.getCanonicalType(ToPointee); 932 Qualifiers Quals = CanonFromPointee.getQualifiers(); 933 934 // Exact qualifier match -> return the pointer type we're converting to. 935 if (CanonToPointee.getLocalQualifiers() == Quals) { 936 // ToType is exactly what we need. Return it. 937 if (!ToType.isNull()) 938 return ToType; 939 940 // Build a pointer to ToPointee. It has the right qualifiers 941 // already. 942 return Context.getPointerType(ToPointee); 943 } 944 945 // Just build a canonical type that has the right qualifiers. 946 return Context.getPointerType( 947 Context.getQualifiedType(CanonToPointee.getLocalUnqualifiedType(), 948 Quals)); 949} 950 951/// BuildSimilarlyQualifiedObjCObjectPointerType - In a pointer conversion from 952/// the FromType, which is an objective-c pointer, to ToType, which may or may 953/// not have the right set of qualifiers. 954static QualType 955BuildSimilarlyQualifiedObjCObjectPointerType(QualType FromType, 956 QualType ToType, 957 ASTContext &Context) { 958 QualType CanonFromType = Context.getCanonicalType(FromType); 959 QualType CanonToType = Context.getCanonicalType(ToType); 960 Qualifiers Quals = CanonFromType.getQualifiers(); 961 962 // Exact qualifier match -> return the pointer type we're converting to. 963 if (CanonToType.getLocalQualifiers() == Quals) 964 return ToType; 965 966 // Just build a canonical type that has the right qualifiers. 967 return Context.getQualifiedType(CanonToType.getLocalUnqualifiedType(), Quals); 968} 969 970static bool isNullPointerConstantForConversion(Expr *Expr, 971 bool InOverloadResolution, 972 ASTContext &Context) { 973 // Handle value-dependent integral null pointer constants correctly. 974 // http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#903 975 if (Expr->isValueDependent() && !Expr->isTypeDependent() && 976 Expr->getType()->isIntegralType()) 977 return !InOverloadResolution; 978 979 return Expr->isNullPointerConstant(Context, 980 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull 981 : Expr::NPC_ValueDependentIsNull); 982} 983 984/// IsPointerConversion - Determines whether the conversion of the 985/// expression From, which has the (possibly adjusted) type FromType, 986/// can be converted to the type ToType via a pointer conversion (C++ 987/// 4.10). If so, returns true and places the converted type (that 988/// might differ from ToType in its cv-qualifiers at some level) into 989/// ConvertedType. 990/// 991/// This routine also supports conversions to and from block pointers 992/// and conversions with Objective-C's 'id', 'id<protocols...>', and 993/// pointers to interfaces. FIXME: Once we've determined the 994/// appropriate overloading rules for Objective-C, we may want to 995/// split the Objective-C checks into a different routine; however, 996/// GCC seems to consider all of these conversions to be pointer 997/// conversions, so for now they live here. IncompatibleObjC will be 998/// set if the conversion is an allowed Objective-C conversion that 999/// should result in a warning. 1000bool Sema::IsPointerConversion(Expr *From, QualType FromType, QualType ToType, 1001 bool InOverloadResolution, 1002 QualType& ConvertedType, 1003 bool &IncompatibleObjC) { 1004 IncompatibleObjC = false; 1005 if (isObjCPointerConversion(FromType, ToType, ConvertedType, IncompatibleObjC)) 1006 return true; 1007 1008 // Conversion from a null pointer constant to any Objective-C pointer type. 1009 if (ToType->isObjCObjectPointerType() && 1010 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1011 ConvertedType = ToType; 1012 return true; 1013 } 1014 1015 // Blocks: Block pointers can be converted to void*. 1016 if (FromType->isBlockPointerType() && ToType->isPointerType() && 1017 ToType->getAs<PointerType>()->getPointeeType()->isVoidType()) { 1018 ConvertedType = ToType; 1019 return true; 1020 } 1021 // Blocks: A null pointer constant can be converted to a block 1022 // pointer type. 1023 if (ToType->isBlockPointerType() && 1024 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1025 ConvertedType = ToType; 1026 return true; 1027 } 1028 1029 // If the left-hand-side is nullptr_t, the right side can be a null 1030 // pointer constant. 1031 if (ToType->isNullPtrType() && 1032 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1033 ConvertedType = ToType; 1034 return true; 1035 } 1036 1037 const PointerType* ToTypePtr = ToType->getAs<PointerType>(); 1038 if (!ToTypePtr) 1039 return false; 1040 1041 // A null pointer constant can be converted to a pointer type (C++ 4.10p1). 1042 if (isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1043 ConvertedType = ToType; 1044 return true; 1045 } 1046 1047 // Beyond this point, both types need to be pointers 1048 // , including objective-c pointers. 1049 QualType ToPointeeType = ToTypePtr->getPointeeType(); 1050 if (FromType->isObjCObjectPointerType() && ToPointeeType->isVoidType()) { 1051 ConvertedType = BuildSimilarlyQualifiedObjCObjectPointerType(FromType, 1052 ToType, Context); 1053 return true; 1054 1055 } 1056 const PointerType *FromTypePtr = FromType->getAs<PointerType>(); 1057 if (!FromTypePtr) 1058 return false; 1059 1060 QualType FromPointeeType = FromTypePtr->getPointeeType(); 1061 1062 // An rvalue of type "pointer to cv T," where T is an object type, 1063 // can be converted to an rvalue of type "pointer to cv void" (C++ 1064 // 4.10p2). 1065 if (FromPointeeType->isObjectType() && ToPointeeType->isVoidType()) { 1066 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1067 ToPointeeType, 1068 ToType, Context); 1069 return true; 1070 } 1071 1072 // When we're overloading in C, we allow a special kind of pointer 1073 // conversion for compatible-but-not-identical pointee types. 1074 if (!getLangOptions().CPlusPlus && 1075 Context.typesAreCompatible(FromPointeeType, ToPointeeType)) { 1076 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1077 ToPointeeType, 1078 ToType, Context); 1079 return true; 1080 } 1081 1082 // C++ [conv.ptr]p3: 1083 // 1084 // An rvalue of type "pointer to cv D," where D is a class type, 1085 // can be converted to an rvalue of type "pointer to cv B," where 1086 // B is a base class (clause 10) of D. If B is an inaccessible 1087 // (clause 11) or ambiguous (10.2) base class of D, a program that 1088 // necessitates this conversion is ill-formed. The result of the 1089 // conversion is a pointer to the base class sub-object of the 1090 // derived class object. The null pointer value is converted to 1091 // the null pointer value of the destination type. 1092 // 1093 // Note that we do not check for ambiguity or inaccessibility 1094 // here. That is handled by CheckPointerConversion. 1095 if (getLangOptions().CPlusPlus && 1096 FromPointeeType->isRecordType() && ToPointeeType->isRecordType() && 1097 !Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType) && 1098 !RequireCompleteType(From->getLocStart(), FromPointeeType, PDiag()) && 1099 IsDerivedFrom(FromPointeeType, ToPointeeType)) { 1100 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1101 ToPointeeType, 1102 ToType, Context); 1103 return true; 1104 } 1105 1106 return false; 1107} 1108 1109/// isObjCPointerConversion - Determines whether this is an 1110/// Objective-C pointer conversion. Subroutine of IsPointerConversion, 1111/// with the same arguments and return values. 1112bool Sema::isObjCPointerConversion(QualType FromType, QualType ToType, 1113 QualType& ConvertedType, 1114 bool &IncompatibleObjC) { 1115 if (!getLangOptions().ObjC1) 1116 return false; 1117 1118 // First, we handle all conversions on ObjC object pointer types. 1119 const ObjCObjectPointerType* ToObjCPtr = ToType->getAs<ObjCObjectPointerType>(); 1120 const ObjCObjectPointerType *FromObjCPtr = 1121 FromType->getAs<ObjCObjectPointerType>(); 1122 1123 if (ToObjCPtr && FromObjCPtr) { 1124 // Objective C++: We're able to convert between "id" or "Class" and a 1125 // pointer to any interface (in both directions). 1126 if (ToObjCPtr->isObjCBuiltinType() && FromObjCPtr->isObjCBuiltinType()) { 1127 ConvertedType = ToType; 1128 return true; 1129 } 1130 // Conversions with Objective-C's id<...>. 1131 if ((FromObjCPtr->isObjCQualifiedIdType() || 1132 ToObjCPtr->isObjCQualifiedIdType()) && 1133 Context.ObjCQualifiedIdTypesAreCompatible(ToType, FromType, 1134 /*compare=*/false)) { 1135 ConvertedType = ToType; 1136 return true; 1137 } 1138 // Objective C++: We're able to convert from a pointer to an 1139 // interface to a pointer to a different interface. 1140 if (Context.canAssignObjCInterfaces(ToObjCPtr, FromObjCPtr)) { 1141 const ObjCInterfaceType* LHS = ToObjCPtr->getInterfaceType(); 1142 const ObjCInterfaceType* RHS = FromObjCPtr->getInterfaceType(); 1143 if (getLangOptions().CPlusPlus && LHS && RHS && 1144 !ToObjCPtr->getPointeeType().isAtLeastAsQualifiedAs( 1145 FromObjCPtr->getPointeeType())) 1146 return false; 1147 ConvertedType = ToType; 1148 return true; 1149 } 1150 1151 if (Context.canAssignObjCInterfaces(FromObjCPtr, ToObjCPtr)) { 1152 // Okay: this is some kind of implicit downcast of Objective-C 1153 // interfaces, which is permitted. However, we're going to 1154 // complain about it. 1155 IncompatibleObjC = true; 1156 ConvertedType = FromType; 1157 return true; 1158 } 1159 } 1160 // Beyond this point, both types need to be C pointers or block pointers. 1161 QualType ToPointeeType; 1162 if (const PointerType *ToCPtr = ToType->getAs<PointerType>()) 1163 ToPointeeType = ToCPtr->getPointeeType(); 1164 else if (const BlockPointerType *ToBlockPtr = 1165 ToType->getAs<BlockPointerType>()) { 1166 // Objective C++: We're able to convert from a pointer to any object 1167 // to a block pointer type. 1168 if (FromObjCPtr && FromObjCPtr->isObjCBuiltinType()) { 1169 ConvertedType = ToType; 1170 return true; 1171 } 1172 ToPointeeType = ToBlockPtr->getPointeeType(); 1173 } 1174 else if (FromType->getAs<BlockPointerType>() && 1175 ToObjCPtr && ToObjCPtr->isObjCBuiltinType()) { 1176 // Objective C++: We're able to convert from a block pointer type to a 1177 // pointer to any object. 1178 ConvertedType = ToType; 1179 return true; 1180 } 1181 else 1182 return false; 1183 1184 QualType FromPointeeType; 1185 if (const PointerType *FromCPtr = FromType->getAs<PointerType>()) 1186 FromPointeeType = FromCPtr->getPointeeType(); 1187 else if (const BlockPointerType *FromBlockPtr = FromType->getAs<BlockPointerType>()) 1188 FromPointeeType = FromBlockPtr->getPointeeType(); 1189 else 1190 return false; 1191 1192 // If we have pointers to pointers, recursively check whether this 1193 // is an Objective-C conversion. 1194 if (FromPointeeType->isPointerType() && ToPointeeType->isPointerType() && 1195 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, 1196 IncompatibleObjC)) { 1197 // We always complain about this conversion. 1198 IncompatibleObjC = true; 1199 ConvertedType = ToType; 1200 return true; 1201 } 1202 // Allow conversion of pointee being objective-c pointer to another one; 1203 // as in I* to id. 1204 if (FromPointeeType->getAs<ObjCObjectPointerType>() && 1205 ToPointeeType->getAs<ObjCObjectPointerType>() && 1206 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, 1207 IncompatibleObjC)) { 1208 ConvertedType = ToType; 1209 return true; 1210 } 1211 1212 // If we have pointers to functions or blocks, check whether the only 1213 // differences in the argument and result types are in Objective-C 1214 // pointer conversions. If so, we permit the conversion (but 1215 // complain about it). 1216 const FunctionProtoType *FromFunctionType 1217 = FromPointeeType->getAs<FunctionProtoType>(); 1218 const FunctionProtoType *ToFunctionType 1219 = ToPointeeType->getAs<FunctionProtoType>(); 1220 if (FromFunctionType && ToFunctionType) { 1221 // If the function types are exactly the same, this isn't an 1222 // Objective-C pointer conversion. 1223 if (Context.getCanonicalType(FromPointeeType) 1224 == Context.getCanonicalType(ToPointeeType)) 1225 return false; 1226 1227 // Perform the quick checks that will tell us whether these 1228 // function types are obviously different. 1229 if (FromFunctionType->getNumArgs() != ToFunctionType->getNumArgs() || 1230 FromFunctionType->isVariadic() != ToFunctionType->isVariadic() || 1231 FromFunctionType->getTypeQuals() != ToFunctionType->getTypeQuals()) 1232 return false; 1233 1234 bool HasObjCConversion = false; 1235 if (Context.getCanonicalType(FromFunctionType->getResultType()) 1236 == Context.getCanonicalType(ToFunctionType->getResultType())) { 1237 // Okay, the types match exactly. Nothing to do. 1238 } else if (isObjCPointerConversion(FromFunctionType->getResultType(), 1239 ToFunctionType->getResultType(), 1240 ConvertedType, IncompatibleObjC)) { 1241 // Okay, we have an Objective-C pointer conversion. 1242 HasObjCConversion = true; 1243 } else { 1244 // Function types are too different. Abort. 1245 return false; 1246 } 1247 1248 // Check argument types. 1249 for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumArgs(); 1250 ArgIdx != NumArgs; ++ArgIdx) { 1251 QualType FromArgType = FromFunctionType->getArgType(ArgIdx); 1252 QualType ToArgType = ToFunctionType->getArgType(ArgIdx); 1253 if (Context.getCanonicalType(FromArgType) 1254 == Context.getCanonicalType(ToArgType)) { 1255 // Okay, the types match exactly. Nothing to do. 1256 } else if (isObjCPointerConversion(FromArgType, ToArgType, 1257 ConvertedType, IncompatibleObjC)) { 1258 // Okay, we have an Objective-C pointer conversion. 1259 HasObjCConversion = true; 1260 } else { 1261 // Argument types are too different. Abort. 1262 return false; 1263 } 1264 } 1265 1266 if (HasObjCConversion) { 1267 // We had an Objective-C conversion. Allow this pointer 1268 // conversion, but complain about it. 1269 ConvertedType = ToType; 1270 IncompatibleObjC = true; 1271 return true; 1272 } 1273 } 1274 1275 return false; 1276} 1277 1278/// CheckPointerConversion - Check the pointer conversion from the 1279/// expression From to the type ToType. This routine checks for 1280/// ambiguous or inaccessible derived-to-base pointer 1281/// conversions for which IsPointerConversion has already returned 1282/// true. It returns true and produces a diagnostic if there was an 1283/// error, or returns false otherwise. 1284bool Sema::CheckPointerConversion(Expr *From, QualType ToType, 1285 CastExpr::CastKind &Kind, 1286 bool IgnoreBaseAccess) { 1287 QualType FromType = From->getType(); 1288 1289 if (const PointerType *FromPtrType = FromType->getAs<PointerType>()) 1290 if (const PointerType *ToPtrType = ToType->getAs<PointerType>()) { 1291 QualType FromPointeeType = FromPtrType->getPointeeType(), 1292 ToPointeeType = ToPtrType->getPointeeType(); 1293 1294 if (FromPointeeType->isRecordType() && ToPointeeType->isRecordType() && 1295 !Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType)) { 1296 // We must have a derived-to-base conversion. Check an 1297 // ambiguous or inaccessible conversion. 1298 if (CheckDerivedToBaseConversion(FromPointeeType, ToPointeeType, 1299 From->getExprLoc(), 1300 From->getSourceRange(), 1301 IgnoreBaseAccess)) 1302 return true; 1303 1304 // The conversion was successful. 1305 Kind = CastExpr::CK_DerivedToBase; 1306 } 1307 } 1308 if (const ObjCObjectPointerType *FromPtrType = 1309 FromType->getAs<ObjCObjectPointerType>()) 1310 if (const ObjCObjectPointerType *ToPtrType = 1311 ToType->getAs<ObjCObjectPointerType>()) { 1312 // Objective-C++ conversions are always okay. 1313 // FIXME: We should have a different class of conversions for the 1314 // Objective-C++ implicit conversions. 1315 if (FromPtrType->isObjCBuiltinType() || ToPtrType->isObjCBuiltinType()) 1316 return false; 1317 1318 } 1319 return false; 1320} 1321 1322/// IsMemberPointerConversion - Determines whether the conversion of the 1323/// expression From, which has the (possibly adjusted) type FromType, can be 1324/// converted to the type ToType via a member pointer conversion (C++ 4.11). 1325/// If so, returns true and places the converted type (that might differ from 1326/// ToType in its cv-qualifiers at some level) into ConvertedType. 1327bool Sema::IsMemberPointerConversion(Expr *From, QualType FromType, 1328 QualType ToType, 1329 bool InOverloadResolution, 1330 QualType &ConvertedType) { 1331 const MemberPointerType *ToTypePtr = ToType->getAs<MemberPointerType>(); 1332 if (!ToTypePtr) 1333 return false; 1334 1335 // A null pointer constant can be converted to a member pointer (C++ 4.11p1) 1336 if (From->isNullPointerConstant(Context, 1337 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull 1338 : Expr::NPC_ValueDependentIsNull)) { 1339 ConvertedType = ToType; 1340 return true; 1341 } 1342 1343 // Otherwise, both types have to be member pointers. 1344 const MemberPointerType *FromTypePtr = FromType->getAs<MemberPointerType>(); 1345 if (!FromTypePtr) 1346 return false; 1347 1348 // A pointer to member of B can be converted to a pointer to member of D, 1349 // where D is derived from B (C++ 4.11p2). 1350 QualType FromClass(FromTypePtr->getClass(), 0); 1351 QualType ToClass(ToTypePtr->getClass(), 0); 1352 // FIXME: What happens when these are dependent? Is this function even called? 1353 1354 if (IsDerivedFrom(ToClass, FromClass)) { 1355 ConvertedType = Context.getMemberPointerType(FromTypePtr->getPointeeType(), 1356 ToClass.getTypePtr()); 1357 return true; 1358 } 1359 1360 return false; 1361} 1362 1363/// CheckMemberPointerConversion - Check the member pointer conversion from the 1364/// expression From to the type ToType. This routine checks for ambiguous or 1365/// virtual or inaccessible base-to-derived member pointer conversions 1366/// for which IsMemberPointerConversion has already returned true. It returns 1367/// true and produces a diagnostic if there was an error, or returns false 1368/// otherwise. 1369bool Sema::CheckMemberPointerConversion(Expr *From, QualType ToType, 1370 CastExpr::CastKind &Kind, 1371 bool IgnoreBaseAccess) { 1372 QualType FromType = From->getType(); 1373 const MemberPointerType *FromPtrType = FromType->getAs<MemberPointerType>(); 1374 if (!FromPtrType) { 1375 // This must be a null pointer to member pointer conversion 1376 assert(From->isNullPointerConstant(Context, 1377 Expr::NPC_ValueDependentIsNull) && 1378 "Expr must be null pointer constant!"); 1379 Kind = CastExpr::CK_NullToMemberPointer; 1380 return false; 1381 } 1382 1383 const MemberPointerType *ToPtrType = ToType->getAs<MemberPointerType>(); 1384 assert(ToPtrType && "No member pointer cast has a target type " 1385 "that is not a member pointer."); 1386 1387 QualType FromClass = QualType(FromPtrType->getClass(), 0); 1388 QualType ToClass = QualType(ToPtrType->getClass(), 0); 1389 1390 // FIXME: What about dependent types? 1391 assert(FromClass->isRecordType() && "Pointer into non-class."); 1392 assert(ToClass->isRecordType() && "Pointer into non-class."); 1393 1394 CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/ true, 1395 /*DetectVirtual=*/true); 1396 bool DerivationOkay = IsDerivedFrom(ToClass, FromClass, Paths); 1397 assert(DerivationOkay && 1398 "Should not have been called if derivation isn't OK."); 1399 (void)DerivationOkay; 1400 1401 if (Paths.isAmbiguous(Context.getCanonicalType(FromClass). 1402 getUnqualifiedType())) { 1403 std::string PathDisplayStr = getAmbiguousPathsDisplayString(Paths); 1404 Diag(From->getExprLoc(), diag::err_ambiguous_memptr_conv) 1405 << 0 << FromClass << ToClass << PathDisplayStr << From->getSourceRange(); 1406 return true; 1407 } 1408 1409 if (const RecordType *VBase = Paths.getDetectedVirtual()) { 1410 Diag(From->getExprLoc(), diag::err_memptr_conv_via_virtual) 1411 << FromClass << ToClass << QualType(VBase, 0) 1412 << From->getSourceRange(); 1413 return true; 1414 } 1415 1416 if (!IgnoreBaseAccess) 1417 CheckBaseClassAccess(From->getExprLoc(), FromClass, ToClass, 1418 Paths.front(), 1419 diag::err_downcast_from_inaccessible_base); 1420 1421 // Must be a base to derived member conversion. 1422 Kind = CastExpr::CK_BaseToDerivedMemberPointer; 1423 return false; 1424} 1425 1426/// IsQualificationConversion - Determines whether the conversion from 1427/// an rvalue of type FromType to ToType is a qualification conversion 1428/// (C++ 4.4). 1429bool 1430Sema::IsQualificationConversion(QualType FromType, QualType ToType) { 1431 FromType = Context.getCanonicalType(FromType); 1432 ToType = Context.getCanonicalType(ToType); 1433 1434 // If FromType and ToType are the same type, this is not a 1435 // qualification conversion. 1436 if (FromType.getUnqualifiedType() == ToType.getUnqualifiedType()) 1437 return false; 1438 1439 // (C++ 4.4p4): 1440 // A conversion can add cv-qualifiers at levels other than the first 1441 // in multi-level pointers, subject to the following rules: [...] 1442 bool PreviousToQualsIncludeConst = true; 1443 bool UnwrappedAnyPointer = false; 1444 while (UnwrapSimilarPointerTypes(FromType, ToType)) { 1445 // Within each iteration of the loop, we check the qualifiers to 1446 // determine if this still looks like a qualification 1447 // conversion. Then, if all is well, we unwrap one more level of 1448 // pointers or pointers-to-members and do it all again 1449 // until there are no more pointers or pointers-to-members left to 1450 // unwrap. 1451 UnwrappedAnyPointer = true; 1452 1453 // -- for every j > 0, if const is in cv 1,j then const is in cv 1454 // 2,j, and similarly for volatile. 1455 if (!ToType.isAtLeastAsQualifiedAs(FromType)) 1456 return false; 1457 1458 // -- if the cv 1,j and cv 2,j are different, then const is in 1459 // every cv for 0 < k < j. 1460 if (FromType.getCVRQualifiers() != ToType.getCVRQualifiers() 1461 && !PreviousToQualsIncludeConst) 1462 return false; 1463 1464 // Keep track of whether all prior cv-qualifiers in the "to" type 1465 // include const. 1466 PreviousToQualsIncludeConst 1467 = PreviousToQualsIncludeConst && ToType.isConstQualified(); 1468 } 1469 1470 // We are left with FromType and ToType being the pointee types 1471 // after unwrapping the original FromType and ToType the same number 1472 // of types. If we unwrapped any pointers, and if FromType and 1473 // ToType have the same unqualified type (since we checked 1474 // qualifiers above), then this is a qualification conversion. 1475 return UnwrappedAnyPointer && Context.hasSameUnqualifiedType(FromType,ToType); 1476} 1477 1478/// Determines whether there is a user-defined conversion sequence 1479/// (C++ [over.ics.user]) that converts expression From to the type 1480/// ToType. If such a conversion exists, User will contain the 1481/// user-defined conversion sequence that performs such a conversion 1482/// and this routine will return true. Otherwise, this routine returns 1483/// false and User is unspecified. 1484/// 1485/// \param AllowConversionFunctions true if the conversion should 1486/// consider conversion functions at all. If false, only constructors 1487/// will be considered. 1488/// 1489/// \param AllowExplicit true if the conversion should consider C++0x 1490/// "explicit" conversion functions as well as non-explicit conversion 1491/// functions (C++0x [class.conv.fct]p2). 1492/// 1493/// \param ForceRValue true if the expression should be treated as an rvalue 1494/// for overload resolution. 1495/// \param UserCast true if looking for user defined conversion for a static 1496/// cast. 1497OverloadingResult Sema::IsUserDefinedConversion(Expr *From, QualType ToType, 1498 UserDefinedConversionSequence& User, 1499 OverloadCandidateSet& CandidateSet, 1500 bool AllowConversionFunctions, 1501 bool AllowExplicit, 1502 bool ForceRValue, 1503 bool UserCast) { 1504 if (const RecordType *ToRecordType = ToType->getAs<RecordType>()) { 1505 if (RequireCompleteType(From->getLocStart(), ToType, PDiag())) { 1506 // We're not going to find any constructors. 1507 } else if (CXXRecordDecl *ToRecordDecl 1508 = dyn_cast<CXXRecordDecl>(ToRecordType->getDecl())) { 1509 // C++ [over.match.ctor]p1: 1510 // When objects of class type are direct-initialized (8.5), or 1511 // copy-initialized from an expression of the same or a 1512 // derived class type (8.5), overload resolution selects the 1513 // constructor. [...] For copy-initialization, the candidate 1514 // functions are all the converting constructors (12.3.1) of 1515 // that class. The argument list is the expression-list within 1516 // the parentheses of the initializer. 1517 bool SuppressUserConversions = !UserCast; 1518 if (Context.hasSameUnqualifiedType(ToType, From->getType()) || 1519 IsDerivedFrom(From->getType(), ToType)) { 1520 SuppressUserConversions = false; 1521 AllowConversionFunctions = false; 1522 } 1523 1524 DeclarationName ConstructorName 1525 = Context.DeclarationNames.getCXXConstructorName( 1526 Context.getCanonicalType(ToType).getUnqualifiedType()); 1527 DeclContext::lookup_iterator Con, ConEnd; 1528 for (llvm::tie(Con, ConEnd) 1529 = ToRecordDecl->lookup(ConstructorName); 1530 Con != ConEnd; ++Con) { 1531 NamedDecl *D = *Con; 1532 DeclAccessPair FoundDecl = DeclAccessPair::make(D, D->getAccess()); 1533 1534 // Find the constructor (which may be a template). 1535 CXXConstructorDecl *Constructor = 0; 1536 FunctionTemplateDecl *ConstructorTmpl 1537 = dyn_cast<FunctionTemplateDecl>(D); 1538 if (ConstructorTmpl) 1539 Constructor 1540 = cast<CXXConstructorDecl>(ConstructorTmpl->getTemplatedDecl()); 1541 else 1542 Constructor = cast<CXXConstructorDecl>(D); 1543 1544 if (!Constructor->isInvalidDecl() && 1545 Constructor->isConvertingConstructor(AllowExplicit)) { 1546 if (ConstructorTmpl) 1547 AddTemplateOverloadCandidate(ConstructorTmpl, FoundDecl, 1548 /*ExplicitArgs*/ 0, 1549 &From, 1, CandidateSet, 1550 SuppressUserConversions, ForceRValue); 1551 else 1552 // Allow one user-defined conversion when user specifies a 1553 // From->ToType conversion via an static cast (c-style, etc). 1554 AddOverloadCandidate(Constructor, FoundDecl, 1555 &From, 1, CandidateSet, 1556 SuppressUserConversions, ForceRValue); 1557 } 1558 } 1559 } 1560 } 1561 1562 if (!AllowConversionFunctions) { 1563 // Don't allow any conversion functions to enter the overload set. 1564 } else if (RequireCompleteType(From->getLocStart(), From->getType(), 1565 PDiag(0) 1566 << From->getSourceRange())) { 1567 // No conversion functions from incomplete types. 1568 } else if (const RecordType *FromRecordType 1569 = From->getType()->getAs<RecordType>()) { 1570 if (CXXRecordDecl *FromRecordDecl 1571 = dyn_cast<CXXRecordDecl>(FromRecordType->getDecl())) { 1572 // Add all of the conversion functions as candidates. 1573 const UnresolvedSetImpl *Conversions 1574 = FromRecordDecl->getVisibleConversionFunctions(); 1575 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 1576 E = Conversions->end(); I != E; ++I) { 1577 DeclAccessPair FoundDecl = I.getPair(); 1578 NamedDecl *D = FoundDecl.getDecl(); 1579 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext()); 1580 if (isa<UsingShadowDecl>(D)) 1581 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 1582 1583 CXXConversionDecl *Conv; 1584 FunctionTemplateDecl *ConvTemplate; 1585 if ((ConvTemplate = dyn_cast<FunctionTemplateDecl>(*I))) 1586 Conv = dyn_cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 1587 else 1588 Conv = dyn_cast<CXXConversionDecl>(*I); 1589 1590 if (AllowExplicit || !Conv->isExplicit()) { 1591 if (ConvTemplate) 1592 AddTemplateConversionCandidate(ConvTemplate, FoundDecl, 1593 ActingContext, From, ToType, 1594 CandidateSet); 1595 else 1596 AddConversionCandidate(Conv, FoundDecl, ActingContext, 1597 From, ToType, CandidateSet); 1598 } 1599 } 1600 } 1601 } 1602 1603 OverloadCandidateSet::iterator Best; 1604 switch (BestViableFunction(CandidateSet, From->getLocStart(), Best)) { 1605 case OR_Success: 1606 // Record the standard conversion we used and the conversion function. 1607 if (CXXConstructorDecl *Constructor 1608 = dyn_cast<CXXConstructorDecl>(Best->Function)) { 1609 // C++ [over.ics.user]p1: 1610 // If the user-defined conversion is specified by a 1611 // constructor (12.3.1), the initial standard conversion 1612 // sequence converts the source type to the type required by 1613 // the argument of the constructor. 1614 // 1615 QualType ThisType = Constructor->getThisType(Context); 1616 if (Best->Conversions[0].isEllipsis()) 1617 User.EllipsisConversion = true; 1618 else { 1619 User.Before = Best->Conversions[0].Standard; 1620 User.EllipsisConversion = false; 1621 } 1622 User.ConversionFunction = Constructor; 1623 User.After.setAsIdentityConversion(); 1624 User.After.setFromType( 1625 ThisType->getAs<PointerType>()->getPointeeType()); 1626 User.After.setAllToTypes(ToType); 1627 return OR_Success; 1628 } else if (CXXConversionDecl *Conversion 1629 = dyn_cast<CXXConversionDecl>(Best->Function)) { 1630 // C++ [over.ics.user]p1: 1631 // 1632 // [...] If the user-defined conversion is specified by a 1633 // conversion function (12.3.2), the initial standard 1634 // conversion sequence converts the source type to the 1635 // implicit object parameter of the conversion function. 1636 User.Before = Best->Conversions[0].Standard; 1637 User.ConversionFunction = Conversion; 1638 User.EllipsisConversion = false; 1639 1640 // C++ [over.ics.user]p2: 1641 // The second standard conversion sequence converts the 1642 // result of the user-defined conversion to the target type 1643 // for the sequence. Since an implicit conversion sequence 1644 // is an initialization, the special rules for 1645 // initialization by user-defined conversion apply when 1646 // selecting the best user-defined conversion for a 1647 // user-defined conversion sequence (see 13.3.3 and 1648 // 13.3.3.1). 1649 User.After = Best->FinalConversion; 1650 return OR_Success; 1651 } else { 1652 assert(false && "Not a constructor or conversion function?"); 1653 return OR_No_Viable_Function; 1654 } 1655 1656 case OR_No_Viable_Function: 1657 return OR_No_Viable_Function; 1658 case OR_Deleted: 1659 // No conversion here! We're done. 1660 return OR_Deleted; 1661 1662 case OR_Ambiguous: 1663 return OR_Ambiguous; 1664 } 1665 1666 return OR_No_Viable_Function; 1667} 1668 1669bool 1670Sema::DiagnoseMultipleUserDefinedConversion(Expr *From, QualType ToType) { 1671 ImplicitConversionSequence ICS; 1672 OverloadCandidateSet CandidateSet(From->getExprLoc()); 1673 OverloadingResult OvResult = 1674 IsUserDefinedConversion(From, ToType, ICS.UserDefined, 1675 CandidateSet, true, false, false); 1676 if (OvResult == OR_Ambiguous) 1677 Diag(From->getSourceRange().getBegin(), 1678 diag::err_typecheck_ambiguous_condition) 1679 << From->getType() << ToType << From->getSourceRange(); 1680 else if (OvResult == OR_No_Viable_Function && !CandidateSet.empty()) 1681 Diag(From->getSourceRange().getBegin(), 1682 diag::err_typecheck_nonviable_condition) 1683 << From->getType() << ToType << From->getSourceRange(); 1684 else 1685 return false; 1686 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, &From, 1); 1687 return true; 1688} 1689 1690/// CompareImplicitConversionSequences - Compare two implicit 1691/// conversion sequences to determine whether one is better than the 1692/// other or if they are indistinguishable (C++ 13.3.3.2). 1693ImplicitConversionSequence::CompareKind 1694Sema::CompareImplicitConversionSequences(const ImplicitConversionSequence& ICS1, 1695 const ImplicitConversionSequence& ICS2) 1696{ 1697 // (C++ 13.3.3.2p2): When comparing the basic forms of implicit 1698 // conversion sequences (as defined in 13.3.3.1) 1699 // -- a standard conversion sequence (13.3.3.1.1) is a better 1700 // conversion sequence than a user-defined conversion sequence or 1701 // an ellipsis conversion sequence, and 1702 // -- a user-defined conversion sequence (13.3.3.1.2) is a better 1703 // conversion sequence than an ellipsis conversion sequence 1704 // (13.3.3.1.3). 1705 // 1706 // C++0x [over.best.ics]p10: 1707 // For the purpose of ranking implicit conversion sequences as 1708 // described in 13.3.3.2, the ambiguous conversion sequence is 1709 // treated as a user-defined sequence that is indistinguishable 1710 // from any other user-defined conversion sequence. 1711 if (ICS1.getKind() < ICS2.getKind()) { 1712 if (!(ICS1.isUserDefined() && ICS2.isAmbiguous())) 1713 return ImplicitConversionSequence::Better; 1714 } else if (ICS2.getKind() < ICS1.getKind()) { 1715 if (!(ICS2.isUserDefined() && ICS1.isAmbiguous())) 1716 return ImplicitConversionSequence::Worse; 1717 } 1718 1719 if (ICS1.isAmbiguous() || ICS2.isAmbiguous()) 1720 return ImplicitConversionSequence::Indistinguishable; 1721 1722 // Two implicit conversion sequences of the same form are 1723 // indistinguishable conversion sequences unless one of the 1724 // following rules apply: (C++ 13.3.3.2p3): 1725 if (ICS1.isStandard()) 1726 return CompareStandardConversionSequences(ICS1.Standard, ICS2.Standard); 1727 else if (ICS1.isUserDefined()) { 1728 // User-defined conversion sequence U1 is a better conversion 1729 // sequence than another user-defined conversion sequence U2 if 1730 // they contain the same user-defined conversion function or 1731 // constructor and if the second standard conversion sequence of 1732 // U1 is better than the second standard conversion sequence of 1733 // U2 (C++ 13.3.3.2p3). 1734 if (ICS1.UserDefined.ConversionFunction == 1735 ICS2.UserDefined.ConversionFunction) 1736 return CompareStandardConversionSequences(ICS1.UserDefined.After, 1737 ICS2.UserDefined.After); 1738 } 1739 1740 return ImplicitConversionSequence::Indistinguishable; 1741} 1742 1743// Per 13.3.3.2p3, compare the given standard conversion sequences to 1744// determine if one is a proper subset of the other. 1745static ImplicitConversionSequence::CompareKind 1746compareStandardConversionSubsets(ASTContext &Context, 1747 const StandardConversionSequence& SCS1, 1748 const StandardConversionSequence& SCS2) { 1749 ImplicitConversionSequence::CompareKind Result 1750 = ImplicitConversionSequence::Indistinguishable; 1751 1752 if (SCS1.Second != SCS2.Second) { 1753 if (SCS1.Second == ICK_Identity) 1754 Result = ImplicitConversionSequence::Better; 1755 else if (SCS2.Second == ICK_Identity) 1756 Result = ImplicitConversionSequence::Worse; 1757 else 1758 return ImplicitConversionSequence::Indistinguishable; 1759 } else if (!Context.hasSameType(SCS1.getToType(1), SCS2.getToType(1))) 1760 return ImplicitConversionSequence::Indistinguishable; 1761 1762 if (SCS1.Third == SCS2.Third) { 1763 return Context.hasSameType(SCS1.getToType(2), SCS2.getToType(2))? Result 1764 : ImplicitConversionSequence::Indistinguishable; 1765 } 1766 1767 if (SCS1.Third == ICK_Identity) 1768 return Result == ImplicitConversionSequence::Worse 1769 ? ImplicitConversionSequence::Indistinguishable 1770 : ImplicitConversionSequence::Better; 1771 1772 if (SCS2.Third == ICK_Identity) 1773 return Result == ImplicitConversionSequence::Better 1774 ? ImplicitConversionSequence::Indistinguishable 1775 : ImplicitConversionSequence::Worse; 1776 1777 return ImplicitConversionSequence::Indistinguishable; 1778} 1779 1780/// CompareStandardConversionSequences - Compare two standard 1781/// conversion sequences to determine whether one is better than the 1782/// other or if they are indistinguishable (C++ 13.3.3.2p3). 1783ImplicitConversionSequence::CompareKind 1784Sema::CompareStandardConversionSequences(const StandardConversionSequence& SCS1, 1785 const StandardConversionSequence& SCS2) 1786{ 1787 // Standard conversion sequence S1 is a better conversion sequence 1788 // than standard conversion sequence S2 if (C++ 13.3.3.2p3): 1789 1790 // -- S1 is a proper subsequence of S2 (comparing the conversion 1791 // sequences in the canonical form defined by 13.3.3.1.1, 1792 // excluding any Lvalue Transformation; the identity conversion 1793 // sequence is considered to be a subsequence of any 1794 // non-identity conversion sequence) or, if not that, 1795 if (ImplicitConversionSequence::CompareKind CK 1796 = compareStandardConversionSubsets(Context, SCS1, SCS2)) 1797 return CK; 1798 1799 // -- the rank of S1 is better than the rank of S2 (by the rules 1800 // defined below), or, if not that, 1801 ImplicitConversionRank Rank1 = SCS1.getRank(); 1802 ImplicitConversionRank Rank2 = SCS2.getRank(); 1803 if (Rank1 < Rank2) 1804 return ImplicitConversionSequence::Better; 1805 else if (Rank2 < Rank1) 1806 return ImplicitConversionSequence::Worse; 1807 1808 // (C++ 13.3.3.2p4): Two conversion sequences with the same rank 1809 // are indistinguishable unless one of the following rules 1810 // applies: 1811 1812 // A conversion that is not a conversion of a pointer, or 1813 // pointer to member, to bool is better than another conversion 1814 // that is such a conversion. 1815 if (SCS1.isPointerConversionToBool() != SCS2.isPointerConversionToBool()) 1816 return SCS2.isPointerConversionToBool() 1817 ? ImplicitConversionSequence::Better 1818 : ImplicitConversionSequence::Worse; 1819 1820 // C++ [over.ics.rank]p4b2: 1821 // 1822 // If class B is derived directly or indirectly from class A, 1823 // conversion of B* to A* is better than conversion of B* to 1824 // void*, and conversion of A* to void* is better than conversion 1825 // of B* to void*. 1826 bool SCS1ConvertsToVoid 1827 = SCS1.isPointerConversionToVoidPointer(Context); 1828 bool SCS2ConvertsToVoid 1829 = SCS2.isPointerConversionToVoidPointer(Context); 1830 if (SCS1ConvertsToVoid != SCS2ConvertsToVoid) { 1831 // Exactly one of the conversion sequences is a conversion to 1832 // a void pointer; it's the worse conversion. 1833 return SCS2ConvertsToVoid ? ImplicitConversionSequence::Better 1834 : ImplicitConversionSequence::Worse; 1835 } else if (!SCS1ConvertsToVoid && !SCS2ConvertsToVoid) { 1836 // Neither conversion sequence converts to a void pointer; compare 1837 // their derived-to-base conversions. 1838 if (ImplicitConversionSequence::CompareKind DerivedCK 1839 = CompareDerivedToBaseConversions(SCS1, SCS2)) 1840 return DerivedCK; 1841 } else if (SCS1ConvertsToVoid && SCS2ConvertsToVoid) { 1842 // Both conversion sequences are conversions to void 1843 // pointers. Compare the source types to determine if there's an 1844 // inheritance relationship in their sources. 1845 QualType FromType1 = SCS1.getFromType(); 1846 QualType FromType2 = SCS2.getFromType(); 1847 1848 // Adjust the types we're converting from via the array-to-pointer 1849 // conversion, if we need to. 1850 if (SCS1.First == ICK_Array_To_Pointer) 1851 FromType1 = Context.getArrayDecayedType(FromType1); 1852 if (SCS2.First == ICK_Array_To_Pointer) 1853 FromType2 = Context.getArrayDecayedType(FromType2); 1854 1855 QualType FromPointee1 1856 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1857 QualType FromPointee2 1858 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1859 1860 if (IsDerivedFrom(FromPointee2, FromPointee1)) 1861 return ImplicitConversionSequence::Better; 1862 else if (IsDerivedFrom(FromPointee1, FromPointee2)) 1863 return ImplicitConversionSequence::Worse; 1864 1865 // Objective-C++: If one interface is more specific than the 1866 // other, it is the better one. 1867 const ObjCInterfaceType* FromIface1 = FromPointee1->getAs<ObjCInterfaceType>(); 1868 const ObjCInterfaceType* FromIface2 = FromPointee2->getAs<ObjCInterfaceType>(); 1869 if (FromIface1 && FromIface1) { 1870 if (Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 1871 return ImplicitConversionSequence::Better; 1872 else if (Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 1873 return ImplicitConversionSequence::Worse; 1874 } 1875 } 1876 1877 // Compare based on qualification conversions (C++ 13.3.3.2p3, 1878 // bullet 3). 1879 if (ImplicitConversionSequence::CompareKind QualCK 1880 = CompareQualificationConversions(SCS1, SCS2)) 1881 return QualCK; 1882 1883 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding) { 1884 // C++0x [over.ics.rank]p3b4: 1885 // -- S1 and S2 are reference bindings (8.5.3) and neither refers to an 1886 // implicit object parameter of a non-static member function declared 1887 // without a ref-qualifier, and S1 binds an rvalue reference to an 1888 // rvalue and S2 binds an lvalue reference. 1889 // FIXME: We don't know if we're dealing with the implicit object parameter, 1890 // or if the member function in this case has a ref qualifier. 1891 // (Of course, we don't have ref qualifiers yet.) 1892 if (SCS1.RRefBinding != SCS2.RRefBinding) 1893 return SCS1.RRefBinding ? ImplicitConversionSequence::Better 1894 : ImplicitConversionSequence::Worse; 1895 1896 // C++ [over.ics.rank]p3b4: 1897 // -- S1 and S2 are reference bindings (8.5.3), and the types to 1898 // which the references refer are the same type except for 1899 // top-level cv-qualifiers, and the type to which the reference 1900 // initialized by S2 refers is more cv-qualified than the type 1901 // to which the reference initialized by S1 refers. 1902 QualType T1 = SCS1.getToType(2); 1903 QualType T2 = SCS2.getToType(2); 1904 T1 = Context.getCanonicalType(T1); 1905 T2 = Context.getCanonicalType(T2); 1906 Qualifiers T1Quals, T2Quals; 1907 QualType UnqualT1 = Context.getUnqualifiedArrayType(T1, T1Quals); 1908 QualType UnqualT2 = Context.getUnqualifiedArrayType(T2, T2Quals); 1909 if (UnqualT1 == UnqualT2) { 1910 // If the type is an array type, promote the element qualifiers to the type 1911 // for comparison. 1912 if (isa<ArrayType>(T1) && T1Quals) 1913 T1 = Context.getQualifiedType(UnqualT1, T1Quals); 1914 if (isa<ArrayType>(T2) && T2Quals) 1915 T2 = Context.getQualifiedType(UnqualT2, T2Quals); 1916 if (T2.isMoreQualifiedThan(T1)) 1917 return ImplicitConversionSequence::Better; 1918 else if (T1.isMoreQualifiedThan(T2)) 1919 return ImplicitConversionSequence::Worse; 1920 } 1921 } 1922 1923 return ImplicitConversionSequence::Indistinguishable; 1924} 1925 1926/// CompareQualificationConversions - Compares two standard conversion 1927/// sequences to determine whether they can be ranked based on their 1928/// qualification conversions (C++ 13.3.3.2p3 bullet 3). 1929ImplicitConversionSequence::CompareKind 1930Sema::CompareQualificationConversions(const StandardConversionSequence& SCS1, 1931 const StandardConversionSequence& SCS2) { 1932 // C++ 13.3.3.2p3: 1933 // -- S1 and S2 differ only in their qualification conversion and 1934 // yield similar types T1 and T2 (C++ 4.4), respectively, and the 1935 // cv-qualification signature of type T1 is a proper subset of 1936 // the cv-qualification signature of type T2, and S1 is not the 1937 // deprecated string literal array-to-pointer conversion (4.2). 1938 if (SCS1.First != SCS2.First || SCS1.Second != SCS2.Second || 1939 SCS1.Third != SCS2.Third || SCS1.Third != ICK_Qualification) 1940 return ImplicitConversionSequence::Indistinguishable; 1941 1942 // FIXME: the example in the standard doesn't use a qualification 1943 // conversion (!) 1944 QualType T1 = SCS1.getToType(2); 1945 QualType T2 = SCS2.getToType(2); 1946 T1 = Context.getCanonicalType(T1); 1947 T2 = Context.getCanonicalType(T2); 1948 Qualifiers T1Quals, T2Quals; 1949 QualType UnqualT1 = Context.getUnqualifiedArrayType(T1, T1Quals); 1950 QualType UnqualT2 = Context.getUnqualifiedArrayType(T2, T2Quals); 1951 1952 // If the types are the same, we won't learn anything by unwrapped 1953 // them. 1954 if (UnqualT1 == UnqualT2) 1955 return ImplicitConversionSequence::Indistinguishable; 1956 1957 // If the type is an array type, promote the element qualifiers to the type 1958 // for comparison. 1959 if (isa<ArrayType>(T1) && T1Quals) 1960 T1 = Context.getQualifiedType(UnqualT1, T1Quals); 1961 if (isa<ArrayType>(T2) && T2Quals) 1962 T2 = Context.getQualifiedType(UnqualT2, T2Quals); 1963 1964 ImplicitConversionSequence::CompareKind Result 1965 = ImplicitConversionSequence::Indistinguishable; 1966 while (UnwrapSimilarPointerTypes(T1, T2)) { 1967 // Within each iteration of the loop, we check the qualifiers to 1968 // determine if this still looks like a qualification 1969 // conversion. Then, if all is well, we unwrap one more level of 1970 // pointers or pointers-to-members and do it all again 1971 // until there are no more pointers or pointers-to-members left 1972 // to unwrap. This essentially mimics what 1973 // IsQualificationConversion does, but here we're checking for a 1974 // strict subset of qualifiers. 1975 if (T1.getCVRQualifiers() == T2.getCVRQualifiers()) 1976 // The qualifiers are the same, so this doesn't tell us anything 1977 // about how the sequences rank. 1978 ; 1979 else if (T2.isMoreQualifiedThan(T1)) { 1980 // T1 has fewer qualifiers, so it could be the better sequence. 1981 if (Result == ImplicitConversionSequence::Worse) 1982 // Neither has qualifiers that are a subset of the other's 1983 // qualifiers. 1984 return ImplicitConversionSequence::Indistinguishable; 1985 1986 Result = ImplicitConversionSequence::Better; 1987 } else if (T1.isMoreQualifiedThan(T2)) { 1988 // T2 has fewer qualifiers, so it could be the better sequence. 1989 if (Result == ImplicitConversionSequence::Better) 1990 // Neither has qualifiers that are a subset of the other's 1991 // qualifiers. 1992 return ImplicitConversionSequence::Indistinguishable; 1993 1994 Result = ImplicitConversionSequence::Worse; 1995 } else { 1996 // Qualifiers are disjoint. 1997 return ImplicitConversionSequence::Indistinguishable; 1998 } 1999 2000 // If the types after this point are equivalent, we're done. 2001 if (Context.hasSameUnqualifiedType(T1, T2)) 2002 break; 2003 } 2004 2005 // Check that the winning standard conversion sequence isn't using 2006 // the deprecated string literal array to pointer conversion. 2007 switch (Result) { 2008 case ImplicitConversionSequence::Better: 2009 if (SCS1.DeprecatedStringLiteralToCharPtr) 2010 Result = ImplicitConversionSequence::Indistinguishable; 2011 break; 2012 2013 case ImplicitConversionSequence::Indistinguishable: 2014 break; 2015 2016 case ImplicitConversionSequence::Worse: 2017 if (SCS2.DeprecatedStringLiteralToCharPtr) 2018 Result = ImplicitConversionSequence::Indistinguishable; 2019 break; 2020 } 2021 2022 return Result; 2023} 2024 2025/// CompareDerivedToBaseConversions - Compares two standard conversion 2026/// sequences to determine whether they can be ranked based on their 2027/// various kinds of derived-to-base conversions (C++ 2028/// [over.ics.rank]p4b3). As part of these checks, we also look at 2029/// conversions between Objective-C interface types. 2030ImplicitConversionSequence::CompareKind 2031Sema::CompareDerivedToBaseConversions(const StandardConversionSequence& SCS1, 2032 const StandardConversionSequence& SCS2) { 2033 QualType FromType1 = SCS1.getFromType(); 2034 QualType ToType1 = SCS1.getToType(1); 2035 QualType FromType2 = SCS2.getFromType(); 2036 QualType ToType2 = SCS2.getToType(1); 2037 2038 // Adjust the types we're converting from via the array-to-pointer 2039 // conversion, if we need to. 2040 if (SCS1.First == ICK_Array_To_Pointer) 2041 FromType1 = Context.getArrayDecayedType(FromType1); 2042 if (SCS2.First == ICK_Array_To_Pointer) 2043 FromType2 = Context.getArrayDecayedType(FromType2); 2044 2045 // Canonicalize all of the types. 2046 FromType1 = Context.getCanonicalType(FromType1); 2047 ToType1 = Context.getCanonicalType(ToType1); 2048 FromType2 = Context.getCanonicalType(FromType2); 2049 ToType2 = Context.getCanonicalType(ToType2); 2050 2051 // C++ [over.ics.rank]p4b3: 2052 // 2053 // If class B is derived directly or indirectly from class A and 2054 // class C is derived directly or indirectly from B, 2055 // 2056 // For Objective-C, we let A, B, and C also be Objective-C 2057 // interfaces. 2058 2059 // Compare based on pointer conversions. 2060 if (SCS1.Second == ICK_Pointer_Conversion && 2061 SCS2.Second == ICK_Pointer_Conversion && 2062 /*FIXME: Remove if Objective-C id conversions get their own rank*/ 2063 FromType1->isPointerType() && FromType2->isPointerType() && 2064 ToType1->isPointerType() && ToType2->isPointerType()) { 2065 QualType FromPointee1 2066 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2067 QualType ToPointee1 2068 = ToType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2069 QualType FromPointee2 2070 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2071 QualType ToPointee2 2072 = ToType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2073 2074 const ObjCInterfaceType* FromIface1 = FromPointee1->getAs<ObjCInterfaceType>(); 2075 const ObjCInterfaceType* FromIface2 = FromPointee2->getAs<ObjCInterfaceType>(); 2076 const ObjCInterfaceType* ToIface1 = ToPointee1->getAs<ObjCInterfaceType>(); 2077 const ObjCInterfaceType* ToIface2 = ToPointee2->getAs<ObjCInterfaceType>(); 2078 2079 // -- conversion of C* to B* is better than conversion of C* to A*, 2080 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 2081 if (IsDerivedFrom(ToPointee1, ToPointee2)) 2082 return ImplicitConversionSequence::Better; 2083 else if (IsDerivedFrom(ToPointee2, ToPointee1)) 2084 return ImplicitConversionSequence::Worse; 2085 2086 if (ToIface1 && ToIface2) { 2087 if (Context.canAssignObjCInterfaces(ToIface2, ToIface1)) 2088 return ImplicitConversionSequence::Better; 2089 else if (Context.canAssignObjCInterfaces(ToIface1, ToIface2)) 2090 return ImplicitConversionSequence::Worse; 2091 } 2092 } 2093 2094 // -- conversion of B* to A* is better than conversion of C* to A*, 2095 if (FromPointee1 != FromPointee2 && ToPointee1 == ToPointee2) { 2096 if (IsDerivedFrom(FromPointee2, FromPointee1)) 2097 return ImplicitConversionSequence::Better; 2098 else if (IsDerivedFrom(FromPointee1, FromPointee2)) 2099 return ImplicitConversionSequence::Worse; 2100 2101 if (FromIface1 && FromIface2) { 2102 if (Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 2103 return ImplicitConversionSequence::Better; 2104 else if (Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 2105 return ImplicitConversionSequence::Worse; 2106 } 2107 } 2108 } 2109 2110 // Ranking of member-pointer types. 2111 if (SCS1.Second == ICK_Pointer_Member && SCS2.Second == ICK_Pointer_Member && 2112 FromType1->isMemberPointerType() && FromType2->isMemberPointerType() && 2113 ToType1->isMemberPointerType() && ToType2->isMemberPointerType()) { 2114 const MemberPointerType * FromMemPointer1 = 2115 FromType1->getAs<MemberPointerType>(); 2116 const MemberPointerType * ToMemPointer1 = 2117 ToType1->getAs<MemberPointerType>(); 2118 const MemberPointerType * FromMemPointer2 = 2119 FromType2->getAs<MemberPointerType>(); 2120 const MemberPointerType * ToMemPointer2 = 2121 ToType2->getAs<MemberPointerType>(); 2122 const Type *FromPointeeType1 = FromMemPointer1->getClass(); 2123 const Type *ToPointeeType1 = ToMemPointer1->getClass(); 2124 const Type *FromPointeeType2 = FromMemPointer2->getClass(); 2125 const Type *ToPointeeType2 = ToMemPointer2->getClass(); 2126 QualType FromPointee1 = QualType(FromPointeeType1, 0).getUnqualifiedType(); 2127 QualType ToPointee1 = QualType(ToPointeeType1, 0).getUnqualifiedType(); 2128 QualType FromPointee2 = QualType(FromPointeeType2, 0).getUnqualifiedType(); 2129 QualType ToPointee2 = QualType(ToPointeeType2, 0).getUnqualifiedType(); 2130 // conversion of A::* to B::* is better than conversion of A::* to C::*, 2131 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 2132 if (IsDerivedFrom(ToPointee1, ToPointee2)) 2133 return ImplicitConversionSequence::Worse; 2134 else if (IsDerivedFrom(ToPointee2, ToPointee1)) 2135 return ImplicitConversionSequence::Better; 2136 } 2137 // conversion of B::* to C::* is better than conversion of A::* to C::* 2138 if (ToPointee1 == ToPointee2 && FromPointee1 != FromPointee2) { 2139 if (IsDerivedFrom(FromPointee1, FromPointee2)) 2140 return ImplicitConversionSequence::Better; 2141 else if (IsDerivedFrom(FromPointee2, FromPointee1)) 2142 return ImplicitConversionSequence::Worse; 2143 } 2144 } 2145 2146 if ((SCS1.ReferenceBinding || SCS1.CopyConstructor) && 2147 (SCS2.ReferenceBinding || SCS2.CopyConstructor) && 2148 SCS1.Second == ICK_Derived_To_Base) { 2149 // -- conversion of C to B is better than conversion of C to A, 2150 // -- binding of an expression of type C to a reference of type 2151 // B& is better than binding an expression of type C to a 2152 // reference of type A&, 2153 if (Context.hasSameUnqualifiedType(FromType1, FromType2) && 2154 !Context.hasSameUnqualifiedType(ToType1, ToType2)) { 2155 if (IsDerivedFrom(ToType1, ToType2)) 2156 return ImplicitConversionSequence::Better; 2157 else if (IsDerivedFrom(ToType2, ToType1)) 2158 return ImplicitConversionSequence::Worse; 2159 } 2160 2161 // -- conversion of B to A is better than conversion of C to A. 2162 // -- binding of an expression of type B to a reference of type 2163 // A& is better than binding an expression of type C to a 2164 // reference of type A&, 2165 if (!Context.hasSameUnqualifiedType(FromType1, FromType2) && 2166 Context.hasSameUnqualifiedType(ToType1, ToType2)) { 2167 if (IsDerivedFrom(FromType2, FromType1)) 2168 return ImplicitConversionSequence::Better; 2169 else if (IsDerivedFrom(FromType1, FromType2)) 2170 return ImplicitConversionSequence::Worse; 2171 } 2172 } 2173 2174 return ImplicitConversionSequence::Indistinguishable; 2175} 2176 2177/// TryCopyInitialization - Try to copy-initialize a value of type 2178/// ToType from the expression From. Return the implicit conversion 2179/// sequence required to pass this argument, which may be a bad 2180/// conversion sequence (meaning that the argument cannot be passed to 2181/// a parameter of this type). If @p SuppressUserConversions, then we 2182/// do not permit any user-defined conversion sequences. If @p ForceRValue, 2183/// then we treat @p From as an rvalue, even if it is an lvalue. 2184ImplicitConversionSequence 2185Sema::TryCopyInitialization(Expr *From, QualType ToType, 2186 bool SuppressUserConversions, bool ForceRValue, 2187 bool InOverloadResolution) { 2188 if (ToType->isReferenceType()) { 2189 ImplicitConversionSequence ICS; 2190 ICS.setBad(BadConversionSequence::no_conversion, From, ToType); 2191 CheckReferenceInit(From, ToType, 2192 /*FIXME:*/From->getLocStart(), 2193 SuppressUserConversions, 2194 /*AllowExplicit=*/false, 2195 ForceRValue, 2196 &ICS); 2197 return ICS; 2198 } else { 2199 return TryImplicitConversion(From, ToType, 2200 SuppressUserConversions, 2201 /*AllowExplicit=*/false, 2202 ForceRValue, 2203 InOverloadResolution); 2204 } 2205} 2206 2207/// TryObjectArgumentInitialization - Try to initialize the object 2208/// parameter of the given member function (@c Method) from the 2209/// expression @p From. 2210ImplicitConversionSequence 2211Sema::TryObjectArgumentInitialization(QualType OrigFromType, 2212 CXXMethodDecl *Method, 2213 CXXRecordDecl *ActingContext) { 2214 QualType ClassType = Context.getTypeDeclType(ActingContext); 2215 // [class.dtor]p2: A destructor can be invoked for a const, volatile or 2216 // const volatile object. 2217 unsigned Quals = isa<CXXDestructorDecl>(Method) ? 2218 Qualifiers::Const | Qualifiers::Volatile : Method->getTypeQualifiers(); 2219 QualType ImplicitParamType = Context.getCVRQualifiedType(ClassType, Quals); 2220 2221 // Set up the conversion sequence as a "bad" conversion, to allow us 2222 // to exit early. 2223 ImplicitConversionSequence ICS; 2224 2225 // We need to have an object of class type. 2226 QualType FromType = OrigFromType; 2227 if (const PointerType *PT = FromType->getAs<PointerType>()) 2228 FromType = PT->getPointeeType(); 2229 2230 assert(FromType->isRecordType()); 2231 2232 // The implicit object parameter is has the type "reference to cv X", 2233 // where X is the class of which the function is a member 2234 // (C++ [over.match.funcs]p4). However, when finding an implicit 2235 // conversion sequence for the argument, we are not allowed to 2236 // create temporaries or perform user-defined conversions 2237 // (C++ [over.match.funcs]p5). We perform a simplified version of 2238 // reference binding here, that allows class rvalues to bind to 2239 // non-constant references. 2240 2241 // First check the qualifiers. We don't care about lvalue-vs-rvalue 2242 // with the implicit object parameter (C++ [over.match.funcs]p5). 2243 QualType FromTypeCanon = Context.getCanonicalType(FromType); 2244 if (ImplicitParamType.getCVRQualifiers() 2245 != FromTypeCanon.getLocalCVRQualifiers() && 2246 !ImplicitParamType.isAtLeastAsQualifiedAs(FromTypeCanon)) { 2247 ICS.setBad(BadConversionSequence::bad_qualifiers, 2248 OrigFromType, ImplicitParamType); 2249 return ICS; 2250 } 2251 2252 // Check that we have either the same type or a derived type. It 2253 // affects the conversion rank. 2254 QualType ClassTypeCanon = Context.getCanonicalType(ClassType); 2255 ImplicitConversionKind SecondKind; 2256 if (ClassTypeCanon == FromTypeCanon.getLocalUnqualifiedType()) { 2257 SecondKind = ICK_Identity; 2258 } else if (IsDerivedFrom(FromType, ClassType)) 2259 SecondKind = ICK_Derived_To_Base; 2260 else { 2261 ICS.setBad(BadConversionSequence::unrelated_class, 2262 FromType, ImplicitParamType); 2263 return ICS; 2264 } 2265 2266 // Success. Mark this as a reference binding. 2267 ICS.setStandard(); 2268 ICS.Standard.setAsIdentityConversion(); 2269 ICS.Standard.Second = SecondKind; 2270 ICS.Standard.setFromType(FromType); 2271 ICS.Standard.setAllToTypes(ImplicitParamType); 2272 ICS.Standard.ReferenceBinding = true; 2273 ICS.Standard.DirectBinding = true; 2274 ICS.Standard.RRefBinding = false; 2275 return ICS; 2276} 2277 2278/// PerformObjectArgumentInitialization - Perform initialization of 2279/// the implicit object parameter for the given Method with the given 2280/// expression. 2281bool 2282Sema::PerformObjectArgumentInitialization(Expr *&From, 2283 NestedNameSpecifier *Qualifier, 2284 NamedDecl *FoundDecl, 2285 CXXMethodDecl *Method) { 2286 QualType FromRecordType, DestType; 2287 QualType ImplicitParamRecordType = 2288 Method->getThisType(Context)->getAs<PointerType>()->getPointeeType(); 2289 2290 if (const PointerType *PT = From->getType()->getAs<PointerType>()) { 2291 FromRecordType = PT->getPointeeType(); 2292 DestType = Method->getThisType(Context); 2293 } else { 2294 FromRecordType = From->getType(); 2295 DestType = ImplicitParamRecordType; 2296 } 2297 2298 // Note that we always use the true parent context when performing 2299 // the actual argument initialization. 2300 ImplicitConversionSequence ICS 2301 = TryObjectArgumentInitialization(From->getType(), Method, 2302 Method->getParent()); 2303 if (ICS.isBad()) 2304 return Diag(From->getSourceRange().getBegin(), 2305 diag::err_implicit_object_parameter_init) 2306 << ImplicitParamRecordType << FromRecordType << From->getSourceRange(); 2307 2308 if (ICS.Standard.Second == ICK_Derived_To_Base) 2309 return PerformObjectMemberConversion(From, Qualifier, FoundDecl, Method); 2310 2311 if (!Context.hasSameType(From->getType(), DestType)) 2312 ImpCastExprToType(From, DestType, CastExpr::CK_NoOp, 2313 /*isLvalue=*/!From->getType()->getAs<PointerType>()); 2314 return false; 2315} 2316 2317/// TryContextuallyConvertToBool - Attempt to contextually convert the 2318/// expression From to bool (C++0x [conv]p3). 2319ImplicitConversionSequence Sema::TryContextuallyConvertToBool(Expr *From) { 2320 return TryImplicitConversion(From, Context.BoolTy, 2321 // FIXME: Are these flags correct? 2322 /*SuppressUserConversions=*/false, 2323 /*AllowExplicit=*/true, 2324 /*ForceRValue=*/false, 2325 /*InOverloadResolution=*/false); 2326} 2327 2328/// PerformContextuallyConvertToBool - Perform a contextual conversion 2329/// of the expression From to bool (C++0x [conv]p3). 2330bool Sema::PerformContextuallyConvertToBool(Expr *&From) { 2331 ImplicitConversionSequence ICS = TryContextuallyConvertToBool(From); 2332 if (!ICS.isBad()) 2333 return PerformImplicitConversion(From, Context.BoolTy, ICS, AA_Converting); 2334 2335 if (!DiagnoseMultipleUserDefinedConversion(From, Context.BoolTy)) 2336 return Diag(From->getSourceRange().getBegin(), 2337 diag::err_typecheck_bool_condition) 2338 << From->getType() << From->getSourceRange(); 2339 return true; 2340} 2341 2342/// AddOverloadCandidate - Adds the given function to the set of 2343/// candidate functions, using the given function call arguments. If 2344/// @p SuppressUserConversions, then don't allow user-defined 2345/// conversions via constructors or conversion operators. 2346/// If @p ForceRValue, treat all arguments as rvalues. This is a slightly 2347/// hacky way to implement the overloading rules for elidable copy 2348/// initialization in C++0x (C++0x 12.8p15). 2349/// 2350/// \para PartialOverloading true if we are performing "partial" overloading 2351/// based on an incomplete set of function arguments. This feature is used by 2352/// code completion. 2353void 2354Sema::AddOverloadCandidate(FunctionDecl *Function, 2355 DeclAccessPair FoundDecl, 2356 Expr **Args, unsigned NumArgs, 2357 OverloadCandidateSet& CandidateSet, 2358 bool SuppressUserConversions, 2359 bool ForceRValue, 2360 bool PartialOverloading) { 2361 const FunctionProtoType* Proto 2362 = dyn_cast<FunctionProtoType>(Function->getType()->getAs<FunctionType>()); 2363 assert(Proto && "Functions without a prototype cannot be overloaded"); 2364 assert(!Function->getDescribedFunctionTemplate() && 2365 "Use AddTemplateOverloadCandidate for function templates"); 2366 2367 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Function)) { 2368 if (!isa<CXXConstructorDecl>(Method)) { 2369 // If we get here, it's because we're calling a member function 2370 // that is named without a member access expression (e.g., 2371 // "this->f") that was either written explicitly or created 2372 // implicitly. This can happen with a qualified call to a member 2373 // function, e.g., X::f(). We use an empty type for the implied 2374 // object argument (C++ [over.call.func]p3), and the acting context 2375 // is irrelevant. 2376 AddMethodCandidate(Method, FoundDecl, Method->getParent(), 2377 QualType(), Args, NumArgs, CandidateSet, 2378 SuppressUserConversions, ForceRValue); 2379 return; 2380 } 2381 // We treat a constructor like a non-member function, since its object 2382 // argument doesn't participate in overload resolution. 2383 } 2384 2385 if (!CandidateSet.isNewCandidate(Function)) 2386 return; 2387 2388 // Overload resolution is always an unevaluated context. 2389 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 2390 2391 if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(Function)){ 2392 // C++ [class.copy]p3: 2393 // A member function template is never instantiated to perform the copy 2394 // of a class object to an object of its class type. 2395 QualType ClassType = Context.getTypeDeclType(Constructor->getParent()); 2396 if (NumArgs == 1 && 2397 Constructor->isCopyConstructorLikeSpecialization() && 2398 (Context.hasSameUnqualifiedType(ClassType, Args[0]->getType()) || 2399 IsDerivedFrom(Args[0]->getType(), ClassType))) 2400 return; 2401 } 2402 2403 // Add this candidate 2404 CandidateSet.push_back(OverloadCandidate()); 2405 OverloadCandidate& Candidate = CandidateSet.back(); 2406 Candidate.FoundDecl = FoundDecl; 2407 Candidate.Function = Function; 2408 Candidate.Viable = true; 2409 Candidate.IsSurrogate = false; 2410 Candidate.IgnoreObjectArgument = false; 2411 2412 unsigned NumArgsInProto = Proto->getNumArgs(); 2413 2414 // (C++ 13.3.2p2): A candidate function having fewer than m 2415 // parameters is viable only if it has an ellipsis in its parameter 2416 // list (8.3.5). 2417 if ((NumArgs + (PartialOverloading && NumArgs)) > NumArgsInProto && 2418 !Proto->isVariadic()) { 2419 Candidate.Viable = false; 2420 Candidate.FailureKind = ovl_fail_too_many_arguments; 2421 return; 2422 } 2423 2424 // (C++ 13.3.2p2): A candidate function having more than m parameters 2425 // is viable only if the (m+1)st parameter has a default argument 2426 // (8.3.6). For the purposes of overload resolution, the 2427 // parameter list is truncated on the right, so that there are 2428 // exactly m parameters. 2429 unsigned MinRequiredArgs = Function->getMinRequiredArguments(); 2430 if (NumArgs < MinRequiredArgs && !PartialOverloading) { 2431 // Not enough arguments. 2432 Candidate.Viable = false; 2433 Candidate.FailureKind = ovl_fail_too_few_arguments; 2434 return; 2435 } 2436 2437 // Determine the implicit conversion sequences for each of the 2438 // arguments. 2439 Candidate.Conversions.resize(NumArgs); 2440 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2441 if (ArgIdx < NumArgsInProto) { 2442 // (C++ 13.3.2p3): for F to be a viable function, there shall 2443 // exist for each argument an implicit conversion sequence 2444 // (13.3.3.1) that converts that argument to the corresponding 2445 // parameter of F. 2446 QualType ParamType = Proto->getArgType(ArgIdx); 2447 Candidate.Conversions[ArgIdx] 2448 = TryCopyInitialization(Args[ArgIdx], ParamType, 2449 SuppressUserConversions, ForceRValue, 2450 /*InOverloadResolution=*/true); 2451 if (Candidate.Conversions[ArgIdx].isBad()) { 2452 Candidate.Viable = false; 2453 Candidate.FailureKind = ovl_fail_bad_conversion; 2454 break; 2455 } 2456 } else { 2457 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2458 // argument for which there is no corresponding parameter is 2459 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2460 Candidate.Conversions[ArgIdx].setEllipsis(); 2461 } 2462 } 2463} 2464 2465/// \brief Add all of the function declarations in the given function set to 2466/// the overload canddiate set. 2467void Sema::AddFunctionCandidates(const UnresolvedSetImpl &Fns, 2468 Expr **Args, unsigned NumArgs, 2469 OverloadCandidateSet& CandidateSet, 2470 bool SuppressUserConversions) { 2471 for (UnresolvedSetIterator F = Fns.begin(), E = Fns.end(); F != E; ++F) { 2472 NamedDecl *D = F.getDecl()->getUnderlyingDecl(); 2473 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { 2474 if (isa<CXXMethodDecl>(FD) && !cast<CXXMethodDecl>(FD)->isStatic()) 2475 AddMethodCandidate(cast<CXXMethodDecl>(FD), F.getPair(), 2476 cast<CXXMethodDecl>(FD)->getParent(), 2477 Args[0]->getType(), Args + 1, NumArgs - 1, 2478 CandidateSet, SuppressUserConversions); 2479 else 2480 AddOverloadCandidate(FD, F.getPair(), Args, NumArgs, CandidateSet, 2481 SuppressUserConversions); 2482 } else { 2483 FunctionTemplateDecl *FunTmpl = cast<FunctionTemplateDecl>(D); 2484 if (isa<CXXMethodDecl>(FunTmpl->getTemplatedDecl()) && 2485 !cast<CXXMethodDecl>(FunTmpl->getTemplatedDecl())->isStatic()) 2486 AddMethodTemplateCandidate(FunTmpl, F.getPair(), 2487 cast<CXXRecordDecl>(FunTmpl->getDeclContext()), 2488 /*FIXME: explicit args */ 0, 2489 Args[0]->getType(), Args + 1, NumArgs - 1, 2490 CandidateSet, 2491 SuppressUserConversions); 2492 else 2493 AddTemplateOverloadCandidate(FunTmpl, F.getPair(), 2494 /*FIXME: explicit args */ 0, 2495 Args, NumArgs, CandidateSet, 2496 SuppressUserConversions); 2497 } 2498 } 2499} 2500 2501/// AddMethodCandidate - Adds a named decl (which is some kind of 2502/// method) as a method candidate to the given overload set. 2503void Sema::AddMethodCandidate(DeclAccessPair FoundDecl, 2504 QualType ObjectType, 2505 Expr **Args, unsigned NumArgs, 2506 OverloadCandidateSet& CandidateSet, 2507 bool SuppressUserConversions, bool ForceRValue) { 2508 NamedDecl *Decl = FoundDecl.getDecl(); 2509 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(Decl->getDeclContext()); 2510 2511 if (isa<UsingShadowDecl>(Decl)) 2512 Decl = cast<UsingShadowDecl>(Decl)->getTargetDecl(); 2513 2514 if (FunctionTemplateDecl *TD = dyn_cast<FunctionTemplateDecl>(Decl)) { 2515 assert(isa<CXXMethodDecl>(TD->getTemplatedDecl()) && 2516 "Expected a member function template"); 2517 AddMethodTemplateCandidate(TD, FoundDecl, ActingContext, 2518 /*ExplicitArgs*/ 0, 2519 ObjectType, Args, NumArgs, 2520 CandidateSet, 2521 SuppressUserConversions, 2522 ForceRValue); 2523 } else { 2524 AddMethodCandidate(cast<CXXMethodDecl>(Decl), FoundDecl, ActingContext, 2525 ObjectType, Args, NumArgs, 2526 CandidateSet, SuppressUserConversions, ForceRValue); 2527 } 2528} 2529 2530/// AddMethodCandidate - Adds the given C++ member function to the set 2531/// of candidate functions, using the given function call arguments 2532/// and the object argument (@c Object). For example, in a call 2533/// @c o.f(a1,a2), @c Object will contain @c o and @c Args will contain 2534/// both @c a1 and @c a2. If @p SuppressUserConversions, then don't 2535/// allow user-defined conversions via constructors or conversion 2536/// operators. If @p ForceRValue, treat all arguments as rvalues. This is 2537/// a slightly hacky way to implement the overloading rules for elidable copy 2538/// initialization in C++0x (C++0x 12.8p15). 2539void 2540Sema::AddMethodCandidate(CXXMethodDecl *Method, DeclAccessPair FoundDecl, 2541 CXXRecordDecl *ActingContext, QualType ObjectType, 2542 Expr **Args, unsigned NumArgs, 2543 OverloadCandidateSet& CandidateSet, 2544 bool SuppressUserConversions, bool ForceRValue) { 2545 const FunctionProtoType* Proto 2546 = dyn_cast<FunctionProtoType>(Method->getType()->getAs<FunctionType>()); 2547 assert(Proto && "Methods without a prototype cannot be overloaded"); 2548 assert(!isa<CXXConstructorDecl>(Method) && 2549 "Use AddOverloadCandidate for constructors"); 2550 2551 if (!CandidateSet.isNewCandidate(Method)) 2552 return; 2553 2554 // Overload resolution is always an unevaluated context. 2555 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 2556 2557 // Add this candidate 2558 CandidateSet.push_back(OverloadCandidate()); 2559 OverloadCandidate& Candidate = CandidateSet.back(); 2560 Candidate.FoundDecl = FoundDecl; 2561 Candidate.Function = Method; 2562 Candidate.IsSurrogate = false; 2563 Candidate.IgnoreObjectArgument = false; 2564 2565 unsigned NumArgsInProto = Proto->getNumArgs(); 2566 2567 // (C++ 13.3.2p2): A candidate function having fewer than m 2568 // parameters is viable only if it has an ellipsis in its parameter 2569 // list (8.3.5). 2570 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 2571 Candidate.Viable = false; 2572 Candidate.FailureKind = ovl_fail_too_many_arguments; 2573 return; 2574 } 2575 2576 // (C++ 13.3.2p2): A candidate function having more than m parameters 2577 // is viable only if the (m+1)st parameter has a default argument 2578 // (8.3.6). For the purposes of overload resolution, the 2579 // parameter list is truncated on the right, so that there are 2580 // exactly m parameters. 2581 unsigned MinRequiredArgs = Method->getMinRequiredArguments(); 2582 if (NumArgs < MinRequiredArgs) { 2583 // Not enough arguments. 2584 Candidate.Viable = false; 2585 Candidate.FailureKind = ovl_fail_too_few_arguments; 2586 return; 2587 } 2588 2589 Candidate.Viable = true; 2590 Candidate.Conversions.resize(NumArgs + 1); 2591 2592 if (Method->isStatic() || ObjectType.isNull()) 2593 // The implicit object argument is ignored. 2594 Candidate.IgnoreObjectArgument = true; 2595 else { 2596 // Determine the implicit conversion sequence for the object 2597 // parameter. 2598 Candidate.Conversions[0] 2599 = TryObjectArgumentInitialization(ObjectType, Method, ActingContext); 2600 if (Candidate.Conversions[0].isBad()) { 2601 Candidate.Viable = false; 2602 Candidate.FailureKind = ovl_fail_bad_conversion; 2603 return; 2604 } 2605 } 2606 2607 // Determine the implicit conversion sequences for each of the 2608 // arguments. 2609 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2610 if (ArgIdx < NumArgsInProto) { 2611 // (C++ 13.3.2p3): for F to be a viable function, there shall 2612 // exist for each argument an implicit conversion sequence 2613 // (13.3.3.1) that converts that argument to the corresponding 2614 // parameter of F. 2615 QualType ParamType = Proto->getArgType(ArgIdx); 2616 Candidate.Conversions[ArgIdx + 1] 2617 = TryCopyInitialization(Args[ArgIdx], ParamType, 2618 SuppressUserConversions, ForceRValue, 2619 /*InOverloadResolution=*/true); 2620 if (Candidate.Conversions[ArgIdx + 1].isBad()) { 2621 Candidate.Viable = false; 2622 Candidate.FailureKind = ovl_fail_bad_conversion; 2623 break; 2624 } 2625 } else { 2626 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2627 // argument for which there is no corresponding parameter is 2628 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2629 Candidate.Conversions[ArgIdx + 1].setEllipsis(); 2630 } 2631 } 2632} 2633 2634/// \brief Add a C++ member function template as a candidate to the candidate 2635/// set, using template argument deduction to produce an appropriate member 2636/// function template specialization. 2637void 2638Sema::AddMethodTemplateCandidate(FunctionTemplateDecl *MethodTmpl, 2639 DeclAccessPair FoundDecl, 2640 CXXRecordDecl *ActingContext, 2641 const TemplateArgumentListInfo *ExplicitTemplateArgs, 2642 QualType ObjectType, 2643 Expr **Args, unsigned NumArgs, 2644 OverloadCandidateSet& CandidateSet, 2645 bool SuppressUserConversions, 2646 bool ForceRValue) { 2647 if (!CandidateSet.isNewCandidate(MethodTmpl)) 2648 return; 2649 2650 // C++ [over.match.funcs]p7: 2651 // In each case where a candidate is a function template, candidate 2652 // function template specializations are generated using template argument 2653 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 2654 // candidate functions in the usual way.113) A given name can refer to one 2655 // or more function templates and also to a set of overloaded non-template 2656 // functions. In such a case, the candidate functions generated from each 2657 // function template are combined with the set of non-template candidate 2658 // functions. 2659 TemplateDeductionInfo Info(Context, CandidateSet.getLocation()); 2660 FunctionDecl *Specialization = 0; 2661 if (TemplateDeductionResult Result 2662 = DeduceTemplateArguments(MethodTmpl, ExplicitTemplateArgs, 2663 Args, NumArgs, Specialization, Info)) { 2664 // FIXME: Record what happened with template argument deduction, so 2665 // that we can give the user a beautiful diagnostic. 2666 (void)Result; 2667 return; 2668 } 2669 2670 // Add the function template specialization produced by template argument 2671 // deduction as a candidate. 2672 assert(Specialization && "Missing member function template specialization?"); 2673 assert(isa<CXXMethodDecl>(Specialization) && 2674 "Specialization is not a member function?"); 2675 AddMethodCandidate(cast<CXXMethodDecl>(Specialization), FoundDecl, 2676 ActingContext, ObjectType, Args, NumArgs, 2677 CandidateSet, SuppressUserConversions, ForceRValue); 2678} 2679 2680/// \brief Add a C++ function template specialization as a candidate 2681/// in the candidate set, using template argument deduction to produce 2682/// an appropriate function template specialization. 2683void 2684Sema::AddTemplateOverloadCandidate(FunctionTemplateDecl *FunctionTemplate, 2685 DeclAccessPair FoundDecl, 2686 const TemplateArgumentListInfo *ExplicitTemplateArgs, 2687 Expr **Args, unsigned NumArgs, 2688 OverloadCandidateSet& CandidateSet, 2689 bool SuppressUserConversions, 2690 bool ForceRValue) { 2691 if (!CandidateSet.isNewCandidate(FunctionTemplate)) 2692 return; 2693 2694 // C++ [over.match.funcs]p7: 2695 // In each case where a candidate is a function template, candidate 2696 // function template specializations are generated using template argument 2697 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 2698 // candidate functions in the usual way.113) A given name can refer to one 2699 // or more function templates and also to a set of overloaded non-template 2700 // functions. In such a case, the candidate functions generated from each 2701 // function template are combined with the set of non-template candidate 2702 // functions. 2703 TemplateDeductionInfo Info(Context, CandidateSet.getLocation()); 2704 FunctionDecl *Specialization = 0; 2705 if (TemplateDeductionResult Result 2706 = DeduceTemplateArguments(FunctionTemplate, ExplicitTemplateArgs, 2707 Args, NumArgs, Specialization, Info)) { 2708 CandidateSet.push_back(OverloadCandidate()); 2709 OverloadCandidate &Candidate = CandidateSet.back(); 2710 Candidate.FoundDecl = FoundDecl; 2711 Candidate.Function = FunctionTemplate->getTemplatedDecl(); 2712 Candidate.Viable = false; 2713 Candidate.FailureKind = ovl_fail_bad_deduction; 2714 Candidate.IsSurrogate = false; 2715 Candidate.IgnoreObjectArgument = false; 2716 2717 // TODO: record more information about failed template arguments 2718 Candidate.DeductionFailure.Result = Result; 2719 Candidate.DeductionFailure.TemplateParameter = Info.Param.getOpaqueValue(); 2720 return; 2721 } 2722 2723 // Add the function template specialization produced by template argument 2724 // deduction as a candidate. 2725 assert(Specialization && "Missing function template specialization?"); 2726 AddOverloadCandidate(Specialization, FoundDecl, Args, NumArgs, CandidateSet, 2727 SuppressUserConversions, ForceRValue); 2728} 2729 2730/// AddConversionCandidate - Add a C++ conversion function as a 2731/// candidate in the candidate set (C++ [over.match.conv], 2732/// C++ [over.match.copy]). From is the expression we're converting from, 2733/// and ToType is the type that we're eventually trying to convert to 2734/// (which may or may not be the same type as the type that the 2735/// conversion function produces). 2736void 2737Sema::AddConversionCandidate(CXXConversionDecl *Conversion, 2738 DeclAccessPair FoundDecl, 2739 CXXRecordDecl *ActingContext, 2740 Expr *From, QualType ToType, 2741 OverloadCandidateSet& CandidateSet) { 2742 assert(!Conversion->getDescribedFunctionTemplate() && 2743 "Conversion function templates use AddTemplateConversionCandidate"); 2744 2745 if (!CandidateSet.isNewCandidate(Conversion)) 2746 return; 2747 2748 // Overload resolution is always an unevaluated context. 2749 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 2750 2751 // Add this candidate 2752 CandidateSet.push_back(OverloadCandidate()); 2753 OverloadCandidate& Candidate = CandidateSet.back(); 2754 Candidate.FoundDecl = FoundDecl; 2755 Candidate.Function = Conversion; 2756 Candidate.IsSurrogate = false; 2757 Candidate.IgnoreObjectArgument = false; 2758 Candidate.FinalConversion.setAsIdentityConversion(); 2759 Candidate.FinalConversion.setFromType(Conversion->getConversionType()); 2760 Candidate.FinalConversion.setAllToTypes(ToType); 2761 2762 // Determine the implicit conversion sequence for the implicit 2763 // object parameter. 2764 Candidate.Viable = true; 2765 Candidate.Conversions.resize(1); 2766 Candidate.Conversions[0] 2767 = TryObjectArgumentInitialization(From->getType(), Conversion, 2768 ActingContext); 2769 // Conversion functions to a different type in the base class is visible in 2770 // the derived class. So, a derived to base conversion should not participate 2771 // in overload resolution. 2772 if (Candidate.Conversions[0].Standard.Second == ICK_Derived_To_Base) 2773 Candidate.Conversions[0].Standard.Second = ICK_Identity; 2774 if (Candidate.Conversions[0].isBad()) { 2775 Candidate.Viable = false; 2776 Candidate.FailureKind = ovl_fail_bad_conversion; 2777 return; 2778 } 2779 2780 // We won't go through a user-define type conversion function to convert a 2781 // derived to base as such conversions are given Conversion Rank. They only 2782 // go through a copy constructor. 13.3.3.1.2-p4 [over.ics.user] 2783 QualType FromCanon 2784 = Context.getCanonicalType(From->getType().getUnqualifiedType()); 2785 QualType ToCanon = Context.getCanonicalType(ToType).getUnqualifiedType(); 2786 if (FromCanon == ToCanon || IsDerivedFrom(FromCanon, ToCanon)) { 2787 Candidate.Viable = false; 2788 Candidate.FailureKind = ovl_fail_trivial_conversion; 2789 return; 2790 } 2791 2792 2793 // To determine what the conversion from the result of calling the 2794 // conversion function to the type we're eventually trying to 2795 // convert to (ToType), we need to synthesize a call to the 2796 // conversion function and attempt copy initialization from it. This 2797 // makes sure that we get the right semantics with respect to 2798 // lvalues/rvalues and the type. Fortunately, we can allocate this 2799 // call on the stack and we don't need its arguments to be 2800 // well-formed. 2801 DeclRefExpr ConversionRef(Conversion, Conversion->getType(), 2802 From->getLocStart()); 2803 ImplicitCastExpr ConversionFn(Context.getPointerType(Conversion->getType()), 2804 CastExpr::CK_FunctionToPointerDecay, 2805 &ConversionRef, false); 2806 2807 // Note that it is safe to allocate CallExpr on the stack here because 2808 // there are 0 arguments (i.e., nothing is allocated using ASTContext's 2809 // allocator). 2810 CallExpr Call(Context, &ConversionFn, 0, 0, 2811 Conversion->getConversionType().getNonReferenceType(), 2812 From->getLocStart()); 2813 ImplicitConversionSequence ICS = 2814 TryCopyInitialization(&Call, ToType, 2815 /*SuppressUserConversions=*/true, 2816 /*ForceRValue=*/false, 2817 /*InOverloadResolution=*/false); 2818 2819 switch (ICS.getKind()) { 2820 case ImplicitConversionSequence::StandardConversion: 2821 Candidate.FinalConversion = ICS.Standard; 2822 break; 2823 2824 case ImplicitConversionSequence::BadConversion: 2825 Candidate.Viable = false; 2826 Candidate.FailureKind = ovl_fail_bad_final_conversion; 2827 break; 2828 2829 default: 2830 assert(false && 2831 "Can only end up with a standard conversion sequence or failure"); 2832 } 2833} 2834 2835/// \brief Adds a conversion function template specialization 2836/// candidate to the overload set, using template argument deduction 2837/// to deduce the template arguments of the conversion function 2838/// template from the type that we are converting to (C++ 2839/// [temp.deduct.conv]). 2840void 2841Sema::AddTemplateConversionCandidate(FunctionTemplateDecl *FunctionTemplate, 2842 DeclAccessPair FoundDecl, 2843 CXXRecordDecl *ActingDC, 2844 Expr *From, QualType ToType, 2845 OverloadCandidateSet &CandidateSet) { 2846 assert(isa<CXXConversionDecl>(FunctionTemplate->getTemplatedDecl()) && 2847 "Only conversion function templates permitted here"); 2848 2849 if (!CandidateSet.isNewCandidate(FunctionTemplate)) 2850 return; 2851 2852 TemplateDeductionInfo Info(Context, CandidateSet.getLocation()); 2853 CXXConversionDecl *Specialization = 0; 2854 if (TemplateDeductionResult Result 2855 = DeduceTemplateArguments(FunctionTemplate, ToType, 2856 Specialization, Info)) { 2857 // FIXME: Record what happened with template argument deduction, so 2858 // that we can give the user a beautiful diagnostic. 2859 (void)Result; 2860 return; 2861 } 2862 2863 // Add the conversion function template specialization produced by 2864 // template argument deduction as a candidate. 2865 assert(Specialization && "Missing function template specialization?"); 2866 AddConversionCandidate(Specialization, FoundDecl, ActingDC, From, ToType, 2867 CandidateSet); 2868} 2869 2870/// AddSurrogateCandidate - Adds a "surrogate" candidate function that 2871/// converts the given @c Object to a function pointer via the 2872/// conversion function @c Conversion, and then attempts to call it 2873/// with the given arguments (C++ [over.call.object]p2-4). Proto is 2874/// the type of function that we'll eventually be calling. 2875void Sema::AddSurrogateCandidate(CXXConversionDecl *Conversion, 2876 DeclAccessPair FoundDecl, 2877 CXXRecordDecl *ActingContext, 2878 const FunctionProtoType *Proto, 2879 QualType ObjectType, 2880 Expr **Args, unsigned NumArgs, 2881 OverloadCandidateSet& CandidateSet) { 2882 if (!CandidateSet.isNewCandidate(Conversion)) 2883 return; 2884 2885 // Overload resolution is always an unevaluated context. 2886 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 2887 2888 CandidateSet.push_back(OverloadCandidate()); 2889 OverloadCandidate& Candidate = CandidateSet.back(); 2890 Candidate.FoundDecl = FoundDecl; 2891 Candidate.Function = 0; 2892 Candidate.Surrogate = Conversion; 2893 Candidate.Viable = true; 2894 Candidate.IsSurrogate = true; 2895 Candidate.IgnoreObjectArgument = false; 2896 Candidate.Conversions.resize(NumArgs + 1); 2897 2898 // Determine the implicit conversion sequence for the implicit 2899 // object parameter. 2900 ImplicitConversionSequence ObjectInit 2901 = TryObjectArgumentInitialization(ObjectType, Conversion, ActingContext); 2902 if (ObjectInit.isBad()) { 2903 Candidate.Viable = false; 2904 Candidate.FailureKind = ovl_fail_bad_conversion; 2905 Candidate.Conversions[0] = ObjectInit; 2906 return; 2907 } 2908 2909 // The first conversion is actually a user-defined conversion whose 2910 // first conversion is ObjectInit's standard conversion (which is 2911 // effectively a reference binding). Record it as such. 2912 Candidate.Conversions[0].setUserDefined(); 2913 Candidate.Conversions[0].UserDefined.Before = ObjectInit.Standard; 2914 Candidate.Conversions[0].UserDefined.EllipsisConversion = false; 2915 Candidate.Conversions[0].UserDefined.ConversionFunction = Conversion; 2916 Candidate.Conversions[0].UserDefined.After 2917 = Candidate.Conversions[0].UserDefined.Before; 2918 Candidate.Conversions[0].UserDefined.After.setAsIdentityConversion(); 2919 2920 // Find the 2921 unsigned NumArgsInProto = Proto->getNumArgs(); 2922 2923 // (C++ 13.3.2p2): A candidate function having fewer than m 2924 // parameters is viable only if it has an ellipsis in its parameter 2925 // list (8.3.5). 2926 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 2927 Candidate.Viable = false; 2928 Candidate.FailureKind = ovl_fail_too_many_arguments; 2929 return; 2930 } 2931 2932 // Function types don't have any default arguments, so just check if 2933 // we have enough arguments. 2934 if (NumArgs < NumArgsInProto) { 2935 // Not enough arguments. 2936 Candidate.Viable = false; 2937 Candidate.FailureKind = ovl_fail_too_few_arguments; 2938 return; 2939 } 2940 2941 // Determine the implicit conversion sequences for each of the 2942 // arguments. 2943 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2944 if (ArgIdx < NumArgsInProto) { 2945 // (C++ 13.3.2p3): for F to be a viable function, there shall 2946 // exist for each argument an implicit conversion sequence 2947 // (13.3.3.1) that converts that argument to the corresponding 2948 // parameter of F. 2949 QualType ParamType = Proto->getArgType(ArgIdx); 2950 Candidate.Conversions[ArgIdx + 1] 2951 = TryCopyInitialization(Args[ArgIdx], ParamType, 2952 /*SuppressUserConversions=*/false, 2953 /*ForceRValue=*/false, 2954 /*InOverloadResolution=*/false); 2955 if (Candidate.Conversions[ArgIdx + 1].isBad()) { 2956 Candidate.Viable = false; 2957 Candidate.FailureKind = ovl_fail_bad_conversion; 2958 break; 2959 } 2960 } else { 2961 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2962 // argument for which there is no corresponding parameter is 2963 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2964 Candidate.Conversions[ArgIdx + 1].setEllipsis(); 2965 } 2966 } 2967} 2968 2969// FIXME: This will eventually be removed, once we've migrated all of the 2970// operator overloading logic over to the scheme used by binary operators, which 2971// works for template instantiation. 2972void Sema::AddOperatorCandidates(OverloadedOperatorKind Op, Scope *S, 2973 SourceLocation OpLoc, 2974 Expr **Args, unsigned NumArgs, 2975 OverloadCandidateSet& CandidateSet, 2976 SourceRange OpRange) { 2977 UnresolvedSet<16> Fns; 2978 2979 QualType T1 = Args[0]->getType(); 2980 QualType T2; 2981 if (NumArgs > 1) 2982 T2 = Args[1]->getType(); 2983 2984 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 2985 if (S) 2986 LookupOverloadedOperatorName(Op, S, T1, T2, Fns); 2987 AddFunctionCandidates(Fns, Args, NumArgs, CandidateSet, false); 2988 AddArgumentDependentLookupCandidates(OpName, false, Args, NumArgs, 0, 2989 CandidateSet); 2990 AddMemberOperatorCandidates(Op, OpLoc, Args, NumArgs, CandidateSet, OpRange); 2991 AddBuiltinOperatorCandidates(Op, OpLoc, Args, NumArgs, CandidateSet); 2992} 2993 2994/// \brief Add overload candidates for overloaded operators that are 2995/// member functions. 2996/// 2997/// Add the overloaded operator candidates that are member functions 2998/// for the operator Op that was used in an operator expression such 2999/// as "x Op y". , Args/NumArgs provides the operator arguments, and 3000/// CandidateSet will store the added overload candidates. (C++ 3001/// [over.match.oper]). 3002void Sema::AddMemberOperatorCandidates(OverloadedOperatorKind Op, 3003 SourceLocation OpLoc, 3004 Expr **Args, unsigned NumArgs, 3005 OverloadCandidateSet& CandidateSet, 3006 SourceRange OpRange) { 3007 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 3008 3009 // C++ [over.match.oper]p3: 3010 // For a unary operator @ with an operand of a type whose 3011 // cv-unqualified version is T1, and for a binary operator @ with 3012 // a left operand of a type whose cv-unqualified version is T1 and 3013 // a right operand of a type whose cv-unqualified version is T2, 3014 // three sets of candidate functions, designated member 3015 // candidates, non-member candidates and built-in candidates, are 3016 // constructed as follows: 3017 QualType T1 = Args[0]->getType(); 3018 QualType T2; 3019 if (NumArgs > 1) 3020 T2 = Args[1]->getType(); 3021 3022 // -- If T1 is a class type, the set of member candidates is the 3023 // result of the qualified lookup of T1::operator@ 3024 // (13.3.1.1.1); otherwise, the set of member candidates is 3025 // empty. 3026 if (const RecordType *T1Rec = T1->getAs<RecordType>()) { 3027 // Complete the type if it can be completed. Otherwise, we're done. 3028 if (RequireCompleteType(OpLoc, T1, PDiag())) 3029 return; 3030 3031 LookupResult Operators(*this, OpName, OpLoc, LookupOrdinaryName); 3032 LookupQualifiedName(Operators, T1Rec->getDecl()); 3033 Operators.suppressDiagnostics(); 3034 3035 for (LookupResult::iterator Oper = Operators.begin(), 3036 OperEnd = Operators.end(); 3037 Oper != OperEnd; 3038 ++Oper) 3039 AddMethodCandidate(Oper.getPair(), Args[0]->getType(), 3040 Args + 1, NumArgs - 1, CandidateSet, 3041 /* SuppressUserConversions = */ false); 3042 } 3043} 3044 3045/// AddBuiltinCandidate - Add a candidate for a built-in 3046/// operator. ResultTy and ParamTys are the result and parameter types 3047/// of the built-in candidate, respectively. Args and NumArgs are the 3048/// arguments being passed to the candidate. IsAssignmentOperator 3049/// should be true when this built-in candidate is an assignment 3050/// operator. NumContextualBoolArguments is the number of arguments 3051/// (at the beginning of the argument list) that will be contextually 3052/// converted to bool. 3053void Sema::AddBuiltinCandidate(QualType ResultTy, QualType *ParamTys, 3054 Expr **Args, unsigned NumArgs, 3055 OverloadCandidateSet& CandidateSet, 3056 bool IsAssignmentOperator, 3057 unsigned NumContextualBoolArguments) { 3058 // Overload resolution is always an unevaluated context. 3059 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 3060 3061 // Add this candidate 3062 CandidateSet.push_back(OverloadCandidate()); 3063 OverloadCandidate& Candidate = CandidateSet.back(); 3064 Candidate.FoundDecl = DeclAccessPair::make(0, AS_none); 3065 Candidate.Function = 0; 3066 Candidate.IsSurrogate = false; 3067 Candidate.IgnoreObjectArgument = false; 3068 Candidate.BuiltinTypes.ResultTy = ResultTy; 3069 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 3070 Candidate.BuiltinTypes.ParamTypes[ArgIdx] = ParamTys[ArgIdx]; 3071 3072 // Determine the implicit conversion sequences for each of the 3073 // arguments. 3074 Candidate.Viable = true; 3075 Candidate.Conversions.resize(NumArgs); 3076 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 3077 // C++ [over.match.oper]p4: 3078 // For the built-in assignment operators, conversions of the 3079 // left operand are restricted as follows: 3080 // -- no temporaries are introduced to hold the left operand, and 3081 // -- no user-defined conversions are applied to the left 3082 // operand to achieve a type match with the left-most 3083 // parameter of a built-in candidate. 3084 // 3085 // We block these conversions by turning off user-defined 3086 // conversions, since that is the only way that initialization of 3087 // a reference to a non-class type can occur from something that 3088 // is not of the same type. 3089 if (ArgIdx < NumContextualBoolArguments) { 3090 assert(ParamTys[ArgIdx] == Context.BoolTy && 3091 "Contextual conversion to bool requires bool type"); 3092 Candidate.Conversions[ArgIdx] = TryContextuallyConvertToBool(Args[ArgIdx]); 3093 } else { 3094 Candidate.Conversions[ArgIdx] 3095 = TryCopyInitialization(Args[ArgIdx], ParamTys[ArgIdx], 3096 ArgIdx == 0 && IsAssignmentOperator, 3097 /*ForceRValue=*/false, 3098 /*InOverloadResolution=*/false); 3099 } 3100 if (Candidate.Conversions[ArgIdx].isBad()) { 3101 Candidate.Viable = false; 3102 Candidate.FailureKind = ovl_fail_bad_conversion; 3103 break; 3104 } 3105 } 3106} 3107 3108/// BuiltinCandidateTypeSet - A set of types that will be used for the 3109/// candidate operator functions for built-in operators (C++ 3110/// [over.built]). The types are separated into pointer types and 3111/// enumeration types. 3112class BuiltinCandidateTypeSet { 3113 /// TypeSet - A set of types. 3114 typedef llvm::SmallPtrSet<QualType, 8> TypeSet; 3115 3116 /// PointerTypes - The set of pointer types that will be used in the 3117 /// built-in candidates. 3118 TypeSet PointerTypes; 3119 3120 /// MemberPointerTypes - The set of member pointer types that will be 3121 /// used in the built-in candidates. 3122 TypeSet MemberPointerTypes; 3123 3124 /// EnumerationTypes - The set of enumeration types that will be 3125 /// used in the built-in candidates. 3126 TypeSet EnumerationTypes; 3127 3128 /// Sema - The semantic analysis instance where we are building the 3129 /// candidate type set. 3130 Sema &SemaRef; 3131 3132 /// Context - The AST context in which we will build the type sets. 3133 ASTContext &Context; 3134 3135 bool AddPointerWithMoreQualifiedTypeVariants(QualType Ty, 3136 const Qualifiers &VisibleQuals); 3137 bool AddMemberPointerWithMoreQualifiedTypeVariants(QualType Ty); 3138 3139public: 3140 /// iterator - Iterates through the types that are part of the set. 3141 typedef TypeSet::iterator iterator; 3142 3143 BuiltinCandidateTypeSet(Sema &SemaRef) 3144 : SemaRef(SemaRef), Context(SemaRef.Context) { } 3145 3146 void AddTypesConvertedFrom(QualType Ty, 3147 SourceLocation Loc, 3148 bool AllowUserConversions, 3149 bool AllowExplicitConversions, 3150 const Qualifiers &VisibleTypeConversionsQuals); 3151 3152 /// pointer_begin - First pointer type found; 3153 iterator pointer_begin() { return PointerTypes.begin(); } 3154 3155 /// pointer_end - Past the last pointer type found; 3156 iterator pointer_end() { return PointerTypes.end(); } 3157 3158 /// member_pointer_begin - First member pointer type found; 3159 iterator member_pointer_begin() { return MemberPointerTypes.begin(); } 3160 3161 /// member_pointer_end - Past the last member pointer type found; 3162 iterator member_pointer_end() { return MemberPointerTypes.end(); } 3163 3164 /// enumeration_begin - First enumeration type found; 3165 iterator enumeration_begin() { return EnumerationTypes.begin(); } 3166 3167 /// enumeration_end - Past the last enumeration type found; 3168 iterator enumeration_end() { return EnumerationTypes.end(); } 3169}; 3170 3171/// AddPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty to 3172/// the set of pointer types along with any more-qualified variants of 3173/// that type. For example, if @p Ty is "int const *", this routine 3174/// will add "int const *", "int const volatile *", "int const 3175/// restrict *", and "int const volatile restrict *" to the set of 3176/// pointer types. Returns true if the add of @p Ty itself succeeded, 3177/// false otherwise. 3178/// 3179/// FIXME: what to do about extended qualifiers? 3180bool 3181BuiltinCandidateTypeSet::AddPointerWithMoreQualifiedTypeVariants(QualType Ty, 3182 const Qualifiers &VisibleQuals) { 3183 3184 // Insert this type. 3185 if (!PointerTypes.insert(Ty)) 3186 return false; 3187 3188 const PointerType *PointerTy = Ty->getAs<PointerType>(); 3189 assert(PointerTy && "type was not a pointer type!"); 3190 3191 QualType PointeeTy = PointerTy->getPointeeType(); 3192 // Don't add qualified variants of arrays. For one, they're not allowed 3193 // (the qualifier would sink to the element type), and for another, the 3194 // only overload situation where it matters is subscript or pointer +- int, 3195 // and those shouldn't have qualifier variants anyway. 3196 if (PointeeTy->isArrayType()) 3197 return true; 3198 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 3199 if (const ConstantArrayType *Array =Context.getAsConstantArrayType(PointeeTy)) 3200 BaseCVR = Array->getElementType().getCVRQualifiers(); 3201 bool hasVolatile = VisibleQuals.hasVolatile(); 3202 bool hasRestrict = VisibleQuals.hasRestrict(); 3203 3204 // Iterate through all strict supersets of BaseCVR. 3205 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 3206 if ((CVR | BaseCVR) != CVR) continue; 3207 // Skip over Volatile/Restrict if no Volatile/Restrict found anywhere 3208 // in the types. 3209 if ((CVR & Qualifiers::Volatile) && !hasVolatile) continue; 3210 if ((CVR & Qualifiers::Restrict) && !hasRestrict) continue; 3211 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 3212 PointerTypes.insert(Context.getPointerType(QPointeeTy)); 3213 } 3214 3215 return true; 3216} 3217 3218/// AddMemberPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty 3219/// to the set of pointer types along with any more-qualified variants of 3220/// that type. For example, if @p Ty is "int const *", this routine 3221/// will add "int const *", "int const volatile *", "int const 3222/// restrict *", and "int const volatile restrict *" to the set of 3223/// pointer types. Returns true if the add of @p Ty itself succeeded, 3224/// false otherwise. 3225/// 3226/// FIXME: what to do about extended qualifiers? 3227bool 3228BuiltinCandidateTypeSet::AddMemberPointerWithMoreQualifiedTypeVariants( 3229 QualType Ty) { 3230 // Insert this type. 3231 if (!MemberPointerTypes.insert(Ty)) 3232 return false; 3233 3234 const MemberPointerType *PointerTy = Ty->getAs<MemberPointerType>(); 3235 assert(PointerTy && "type was not a member pointer type!"); 3236 3237 QualType PointeeTy = PointerTy->getPointeeType(); 3238 // Don't add qualified variants of arrays. For one, they're not allowed 3239 // (the qualifier would sink to the element type), and for another, the 3240 // only overload situation where it matters is subscript or pointer +- int, 3241 // and those shouldn't have qualifier variants anyway. 3242 if (PointeeTy->isArrayType()) 3243 return true; 3244 const Type *ClassTy = PointerTy->getClass(); 3245 3246 // Iterate through all strict supersets of the pointee type's CVR 3247 // qualifiers. 3248 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 3249 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 3250 if ((CVR | BaseCVR) != CVR) continue; 3251 3252 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 3253 MemberPointerTypes.insert(Context.getMemberPointerType(QPointeeTy, ClassTy)); 3254 } 3255 3256 return true; 3257} 3258 3259/// AddTypesConvertedFrom - Add each of the types to which the type @p 3260/// Ty can be implicit converted to the given set of @p Types. We're 3261/// primarily interested in pointer types and enumeration types. We also 3262/// take member pointer types, for the conditional operator. 3263/// AllowUserConversions is true if we should look at the conversion 3264/// functions of a class type, and AllowExplicitConversions if we 3265/// should also include the explicit conversion functions of a class 3266/// type. 3267void 3268BuiltinCandidateTypeSet::AddTypesConvertedFrom(QualType Ty, 3269 SourceLocation Loc, 3270 bool AllowUserConversions, 3271 bool AllowExplicitConversions, 3272 const Qualifiers &VisibleQuals) { 3273 // Only deal with canonical types. 3274 Ty = Context.getCanonicalType(Ty); 3275 3276 // Look through reference types; they aren't part of the type of an 3277 // expression for the purposes of conversions. 3278 if (const ReferenceType *RefTy = Ty->getAs<ReferenceType>()) 3279 Ty = RefTy->getPointeeType(); 3280 3281 // We don't care about qualifiers on the type. 3282 Ty = Ty.getLocalUnqualifiedType(); 3283 3284 // If we're dealing with an array type, decay to the pointer. 3285 if (Ty->isArrayType()) 3286 Ty = SemaRef.Context.getArrayDecayedType(Ty); 3287 3288 if (const PointerType *PointerTy = Ty->getAs<PointerType>()) { 3289 QualType PointeeTy = PointerTy->getPointeeType(); 3290 3291 // Insert our type, and its more-qualified variants, into the set 3292 // of types. 3293 if (!AddPointerWithMoreQualifiedTypeVariants(Ty, VisibleQuals)) 3294 return; 3295 } else if (Ty->isMemberPointerType()) { 3296 // Member pointers are far easier, since the pointee can't be converted. 3297 if (!AddMemberPointerWithMoreQualifiedTypeVariants(Ty)) 3298 return; 3299 } else if (Ty->isEnumeralType()) { 3300 EnumerationTypes.insert(Ty); 3301 } else if (AllowUserConversions) { 3302 if (const RecordType *TyRec = Ty->getAs<RecordType>()) { 3303 if (SemaRef.RequireCompleteType(Loc, Ty, 0)) { 3304 // No conversion functions in incomplete types. 3305 return; 3306 } 3307 3308 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 3309 const UnresolvedSetImpl *Conversions 3310 = ClassDecl->getVisibleConversionFunctions(); 3311 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 3312 E = Conversions->end(); I != E; ++I) { 3313 3314 // Skip conversion function templates; they don't tell us anything 3315 // about which builtin types we can convert to. 3316 if (isa<FunctionTemplateDecl>(*I)) 3317 continue; 3318 3319 CXXConversionDecl *Conv = cast<CXXConversionDecl>(*I); 3320 if (AllowExplicitConversions || !Conv->isExplicit()) { 3321 AddTypesConvertedFrom(Conv->getConversionType(), Loc, false, false, 3322 VisibleQuals); 3323 } 3324 } 3325 } 3326 } 3327} 3328 3329/// \brief Helper function for AddBuiltinOperatorCandidates() that adds 3330/// the volatile- and non-volatile-qualified assignment operators for the 3331/// given type to the candidate set. 3332static void AddBuiltinAssignmentOperatorCandidates(Sema &S, 3333 QualType T, 3334 Expr **Args, 3335 unsigned NumArgs, 3336 OverloadCandidateSet &CandidateSet) { 3337 QualType ParamTypes[2]; 3338 3339 // T& operator=(T&, T) 3340 ParamTypes[0] = S.Context.getLValueReferenceType(T); 3341 ParamTypes[1] = T; 3342 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3343 /*IsAssignmentOperator=*/true); 3344 3345 if (!S.Context.getCanonicalType(T).isVolatileQualified()) { 3346 // volatile T& operator=(volatile T&, T) 3347 ParamTypes[0] 3348 = S.Context.getLValueReferenceType(S.Context.getVolatileType(T)); 3349 ParamTypes[1] = T; 3350 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3351 /*IsAssignmentOperator=*/true); 3352 } 3353} 3354 3355/// CollectVRQualifiers - This routine returns Volatile/Restrict qualifiers, 3356/// if any, found in visible type conversion functions found in ArgExpr's type. 3357static Qualifiers CollectVRQualifiers(ASTContext &Context, Expr* ArgExpr) { 3358 Qualifiers VRQuals; 3359 const RecordType *TyRec; 3360 if (const MemberPointerType *RHSMPType = 3361 ArgExpr->getType()->getAs<MemberPointerType>()) 3362 TyRec = cast<RecordType>(RHSMPType->getClass()); 3363 else 3364 TyRec = ArgExpr->getType()->getAs<RecordType>(); 3365 if (!TyRec) { 3366 // Just to be safe, assume the worst case. 3367 VRQuals.addVolatile(); 3368 VRQuals.addRestrict(); 3369 return VRQuals; 3370 } 3371 3372 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 3373 if (!ClassDecl->hasDefinition()) 3374 return VRQuals; 3375 3376 const UnresolvedSetImpl *Conversions = 3377 ClassDecl->getVisibleConversionFunctions(); 3378 3379 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 3380 E = Conversions->end(); I != E; ++I) { 3381 if (CXXConversionDecl *Conv = dyn_cast<CXXConversionDecl>(*I)) { 3382 QualType CanTy = Context.getCanonicalType(Conv->getConversionType()); 3383 if (const ReferenceType *ResTypeRef = CanTy->getAs<ReferenceType>()) 3384 CanTy = ResTypeRef->getPointeeType(); 3385 // Need to go down the pointer/mempointer chain and add qualifiers 3386 // as see them. 3387 bool done = false; 3388 while (!done) { 3389 if (const PointerType *ResTypePtr = CanTy->getAs<PointerType>()) 3390 CanTy = ResTypePtr->getPointeeType(); 3391 else if (const MemberPointerType *ResTypeMPtr = 3392 CanTy->getAs<MemberPointerType>()) 3393 CanTy = ResTypeMPtr->getPointeeType(); 3394 else 3395 done = true; 3396 if (CanTy.isVolatileQualified()) 3397 VRQuals.addVolatile(); 3398 if (CanTy.isRestrictQualified()) 3399 VRQuals.addRestrict(); 3400 if (VRQuals.hasRestrict() && VRQuals.hasVolatile()) 3401 return VRQuals; 3402 } 3403 } 3404 } 3405 return VRQuals; 3406} 3407 3408/// AddBuiltinOperatorCandidates - Add the appropriate built-in 3409/// operator overloads to the candidate set (C++ [over.built]), based 3410/// on the operator @p Op and the arguments given. For example, if the 3411/// operator is a binary '+', this routine might add "int 3412/// operator+(int, int)" to cover integer addition. 3413void 3414Sema::AddBuiltinOperatorCandidates(OverloadedOperatorKind Op, 3415 SourceLocation OpLoc, 3416 Expr **Args, unsigned NumArgs, 3417 OverloadCandidateSet& CandidateSet) { 3418 // The set of "promoted arithmetic types", which are the arithmetic 3419 // types are that preserved by promotion (C++ [over.built]p2). Note 3420 // that the first few of these types are the promoted integral 3421 // types; these types need to be first. 3422 // FIXME: What about complex? 3423 const unsigned FirstIntegralType = 0; 3424 const unsigned LastIntegralType = 13; 3425 const unsigned FirstPromotedIntegralType = 7, 3426 LastPromotedIntegralType = 13; 3427 const unsigned FirstPromotedArithmeticType = 7, 3428 LastPromotedArithmeticType = 16; 3429 const unsigned NumArithmeticTypes = 16; 3430 QualType ArithmeticTypes[NumArithmeticTypes] = { 3431 Context.BoolTy, Context.CharTy, Context.WCharTy, 3432// FIXME: Context.Char16Ty, Context.Char32Ty, 3433 Context.SignedCharTy, Context.ShortTy, 3434 Context.UnsignedCharTy, Context.UnsignedShortTy, 3435 Context.IntTy, Context.LongTy, Context.LongLongTy, 3436 Context.UnsignedIntTy, Context.UnsignedLongTy, Context.UnsignedLongLongTy, 3437 Context.FloatTy, Context.DoubleTy, Context.LongDoubleTy 3438 }; 3439 assert(ArithmeticTypes[FirstPromotedIntegralType] == Context.IntTy && 3440 "Invalid first promoted integral type"); 3441 assert(ArithmeticTypes[LastPromotedIntegralType - 1] 3442 == Context.UnsignedLongLongTy && 3443 "Invalid last promoted integral type"); 3444 assert(ArithmeticTypes[FirstPromotedArithmeticType] == Context.IntTy && 3445 "Invalid first promoted arithmetic type"); 3446 assert(ArithmeticTypes[LastPromotedArithmeticType - 1] 3447 == Context.LongDoubleTy && 3448 "Invalid last promoted arithmetic type"); 3449 3450 // Find all of the types that the arguments can convert to, but only 3451 // if the operator we're looking at has built-in operator candidates 3452 // that make use of these types. 3453 Qualifiers VisibleTypeConversionsQuals; 3454 VisibleTypeConversionsQuals.addConst(); 3455 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 3456 VisibleTypeConversionsQuals += CollectVRQualifiers(Context, Args[ArgIdx]); 3457 3458 BuiltinCandidateTypeSet CandidateTypes(*this); 3459 if (Op == OO_Less || Op == OO_Greater || Op == OO_LessEqual || 3460 Op == OO_GreaterEqual || Op == OO_EqualEqual || Op == OO_ExclaimEqual || 3461 Op == OO_Plus || (Op == OO_Minus && NumArgs == 2) || Op == OO_Equal || 3462 Op == OO_PlusEqual || Op == OO_MinusEqual || Op == OO_Subscript || 3463 Op == OO_ArrowStar || Op == OO_PlusPlus || Op == OO_MinusMinus || 3464 (Op == OO_Star && NumArgs == 1) || Op == OO_Conditional) { 3465 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 3466 CandidateTypes.AddTypesConvertedFrom(Args[ArgIdx]->getType(), 3467 OpLoc, 3468 true, 3469 (Op == OO_Exclaim || 3470 Op == OO_AmpAmp || 3471 Op == OO_PipePipe), 3472 VisibleTypeConversionsQuals); 3473 } 3474 3475 bool isComparison = false; 3476 switch (Op) { 3477 case OO_None: 3478 case NUM_OVERLOADED_OPERATORS: 3479 assert(false && "Expected an overloaded operator"); 3480 break; 3481 3482 case OO_Star: // '*' is either unary or binary 3483 if (NumArgs == 1) 3484 goto UnaryStar; 3485 else 3486 goto BinaryStar; 3487 break; 3488 3489 case OO_Plus: // '+' is either unary or binary 3490 if (NumArgs == 1) 3491 goto UnaryPlus; 3492 else 3493 goto BinaryPlus; 3494 break; 3495 3496 case OO_Minus: // '-' is either unary or binary 3497 if (NumArgs == 1) 3498 goto UnaryMinus; 3499 else 3500 goto BinaryMinus; 3501 break; 3502 3503 case OO_Amp: // '&' is either unary or binary 3504 if (NumArgs == 1) 3505 goto UnaryAmp; 3506 else 3507 goto BinaryAmp; 3508 3509 case OO_PlusPlus: 3510 case OO_MinusMinus: 3511 // C++ [over.built]p3: 3512 // 3513 // For every pair (T, VQ), where T is an arithmetic type, and VQ 3514 // is either volatile or empty, there exist candidate operator 3515 // functions of the form 3516 // 3517 // VQ T& operator++(VQ T&); 3518 // T operator++(VQ T&, int); 3519 // 3520 // C++ [over.built]p4: 3521 // 3522 // For every pair (T, VQ), where T is an arithmetic type other 3523 // than bool, and VQ is either volatile or empty, there exist 3524 // candidate operator functions of the form 3525 // 3526 // VQ T& operator--(VQ T&); 3527 // T operator--(VQ T&, int); 3528 for (unsigned Arith = (Op == OO_PlusPlus? 0 : 1); 3529 Arith < NumArithmeticTypes; ++Arith) { 3530 QualType ArithTy = ArithmeticTypes[Arith]; 3531 QualType ParamTypes[2] 3532 = { Context.getLValueReferenceType(ArithTy), Context.IntTy }; 3533 3534 // Non-volatile version. 3535 if (NumArgs == 1) 3536 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3537 else 3538 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 3539 // heuristic to reduce number of builtin candidates in the set. 3540 // Add volatile version only if there are conversions to a volatile type. 3541 if (VisibleTypeConversionsQuals.hasVolatile()) { 3542 // Volatile version 3543 ParamTypes[0] 3544 = Context.getLValueReferenceType(Context.getVolatileType(ArithTy)); 3545 if (NumArgs == 1) 3546 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3547 else 3548 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 3549 } 3550 } 3551 3552 // C++ [over.built]p5: 3553 // 3554 // For every pair (T, VQ), where T is a cv-qualified or 3555 // cv-unqualified object type, and VQ is either volatile or 3556 // empty, there exist candidate operator functions of the form 3557 // 3558 // T*VQ& operator++(T*VQ&); 3559 // T*VQ& operator--(T*VQ&); 3560 // T* operator++(T*VQ&, int); 3561 // T* operator--(T*VQ&, int); 3562 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3563 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3564 // Skip pointer types that aren't pointers to object types. 3565 if (!(*Ptr)->getAs<PointerType>()->getPointeeType()->isObjectType()) 3566 continue; 3567 3568 QualType ParamTypes[2] = { 3569 Context.getLValueReferenceType(*Ptr), Context.IntTy 3570 }; 3571 3572 // Without volatile 3573 if (NumArgs == 1) 3574 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3575 else 3576 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3577 3578 if (!Context.getCanonicalType(*Ptr).isVolatileQualified() && 3579 VisibleTypeConversionsQuals.hasVolatile()) { 3580 // With volatile 3581 ParamTypes[0] 3582 = Context.getLValueReferenceType(Context.getVolatileType(*Ptr)); 3583 if (NumArgs == 1) 3584 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3585 else 3586 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3587 } 3588 } 3589 break; 3590 3591 UnaryStar: 3592 // C++ [over.built]p6: 3593 // For every cv-qualified or cv-unqualified object type T, there 3594 // exist candidate operator functions of the form 3595 // 3596 // T& operator*(T*); 3597 // 3598 // C++ [over.built]p7: 3599 // For every function type T, there exist candidate operator 3600 // functions of the form 3601 // T& operator*(T*); 3602 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3603 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3604 QualType ParamTy = *Ptr; 3605 QualType PointeeTy = ParamTy->getAs<PointerType>()->getPointeeType(); 3606 AddBuiltinCandidate(Context.getLValueReferenceType(PointeeTy), 3607 &ParamTy, Args, 1, CandidateSet); 3608 } 3609 break; 3610 3611 UnaryPlus: 3612 // C++ [over.built]p8: 3613 // For every type T, there exist candidate operator functions of 3614 // the form 3615 // 3616 // T* operator+(T*); 3617 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3618 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3619 QualType ParamTy = *Ptr; 3620 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet); 3621 } 3622 3623 // Fall through 3624 3625 UnaryMinus: 3626 // C++ [over.built]p9: 3627 // For every promoted arithmetic type T, there exist candidate 3628 // operator functions of the form 3629 // 3630 // T operator+(T); 3631 // T operator-(T); 3632 for (unsigned Arith = FirstPromotedArithmeticType; 3633 Arith < LastPromotedArithmeticType; ++Arith) { 3634 QualType ArithTy = ArithmeticTypes[Arith]; 3635 AddBuiltinCandidate(ArithTy, &ArithTy, Args, 1, CandidateSet); 3636 } 3637 break; 3638 3639 case OO_Tilde: 3640 // C++ [over.built]p10: 3641 // For every promoted integral type T, there exist candidate 3642 // operator functions of the form 3643 // 3644 // T operator~(T); 3645 for (unsigned Int = FirstPromotedIntegralType; 3646 Int < LastPromotedIntegralType; ++Int) { 3647 QualType IntTy = ArithmeticTypes[Int]; 3648 AddBuiltinCandidate(IntTy, &IntTy, Args, 1, CandidateSet); 3649 } 3650 break; 3651 3652 case OO_New: 3653 case OO_Delete: 3654 case OO_Array_New: 3655 case OO_Array_Delete: 3656 case OO_Call: 3657 assert(false && "Special operators don't use AddBuiltinOperatorCandidates"); 3658 break; 3659 3660 case OO_Comma: 3661 UnaryAmp: 3662 case OO_Arrow: 3663 // C++ [over.match.oper]p3: 3664 // -- For the operator ',', the unary operator '&', or the 3665 // operator '->', the built-in candidates set is empty. 3666 break; 3667 3668 case OO_EqualEqual: 3669 case OO_ExclaimEqual: 3670 // C++ [over.match.oper]p16: 3671 // For every pointer to member type T, there exist candidate operator 3672 // functions of the form 3673 // 3674 // bool operator==(T,T); 3675 // bool operator!=(T,T); 3676 for (BuiltinCandidateTypeSet::iterator 3677 MemPtr = CandidateTypes.member_pointer_begin(), 3678 MemPtrEnd = CandidateTypes.member_pointer_end(); 3679 MemPtr != MemPtrEnd; 3680 ++MemPtr) { 3681 QualType ParamTypes[2] = { *MemPtr, *MemPtr }; 3682 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 3683 } 3684 3685 // Fall through 3686 3687 case OO_Less: 3688 case OO_Greater: 3689 case OO_LessEqual: 3690 case OO_GreaterEqual: 3691 // C++ [over.built]p15: 3692 // 3693 // For every pointer or enumeration type T, there exist 3694 // candidate operator functions of the form 3695 // 3696 // bool operator<(T, T); 3697 // bool operator>(T, T); 3698 // bool operator<=(T, T); 3699 // bool operator>=(T, T); 3700 // bool operator==(T, T); 3701 // bool operator!=(T, T); 3702 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3703 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3704 QualType ParamTypes[2] = { *Ptr, *Ptr }; 3705 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 3706 } 3707 for (BuiltinCandidateTypeSet::iterator Enum 3708 = CandidateTypes.enumeration_begin(); 3709 Enum != CandidateTypes.enumeration_end(); ++Enum) { 3710 QualType ParamTypes[2] = { *Enum, *Enum }; 3711 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 3712 } 3713 3714 // Fall through. 3715 isComparison = true; 3716 3717 BinaryPlus: 3718 BinaryMinus: 3719 if (!isComparison) { 3720 // We didn't fall through, so we must have OO_Plus or OO_Minus. 3721 3722 // C++ [over.built]p13: 3723 // 3724 // For every cv-qualified or cv-unqualified object type T 3725 // there exist candidate operator functions of the form 3726 // 3727 // T* operator+(T*, ptrdiff_t); 3728 // T& operator[](T*, ptrdiff_t); [BELOW] 3729 // T* operator-(T*, ptrdiff_t); 3730 // T* operator+(ptrdiff_t, T*); 3731 // T& operator[](ptrdiff_t, T*); [BELOW] 3732 // 3733 // C++ [over.built]p14: 3734 // 3735 // For every T, where T is a pointer to object type, there 3736 // exist candidate operator functions of the form 3737 // 3738 // ptrdiff_t operator-(T, T); 3739 for (BuiltinCandidateTypeSet::iterator Ptr 3740 = CandidateTypes.pointer_begin(); 3741 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3742 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 3743 3744 // operator+(T*, ptrdiff_t) or operator-(T*, ptrdiff_t) 3745 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3746 3747 if (Op == OO_Plus) { 3748 // T* operator+(ptrdiff_t, T*); 3749 ParamTypes[0] = ParamTypes[1]; 3750 ParamTypes[1] = *Ptr; 3751 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3752 } else { 3753 // ptrdiff_t operator-(T, T); 3754 ParamTypes[1] = *Ptr; 3755 AddBuiltinCandidate(Context.getPointerDiffType(), ParamTypes, 3756 Args, 2, CandidateSet); 3757 } 3758 } 3759 } 3760 // Fall through 3761 3762 case OO_Slash: 3763 BinaryStar: 3764 Conditional: 3765 // C++ [over.built]p12: 3766 // 3767 // For every pair of promoted arithmetic types L and R, there 3768 // exist candidate operator functions of the form 3769 // 3770 // LR operator*(L, R); 3771 // LR operator/(L, R); 3772 // LR operator+(L, R); 3773 // LR operator-(L, R); 3774 // bool operator<(L, R); 3775 // bool operator>(L, R); 3776 // bool operator<=(L, R); 3777 // bool operator>=(L, R); 3778 // bool operator==(L, R); 3779 // bool operator!=(L, R); 3780 // 3781 // where LR is the result of the usual arithmetic conversions 3782 // between types L and R. 3783 // 3784 // C++ [over.built]p24: 3785 // 3786 // For every pair of promoted arithmetic types L and R, there exist 3787 // candidate operator functions of the form 3788 // 3789 // LR operator?(bool, L, R); 3790 // 3791 // where LR is the result of the usual arithmetic conversions 3792 // between types L and R. 3793 // Our candidates ignore the first parameter. 3794 for (unsigned Left = FirstPromotedArithmeticType; 3795 Left < LastPromotedArithmeticType; ++Left) { 3796 for (unsigned Right = FirstPromotedArithmeticType; 3797 Right < LastPromotedArithmeticType; ++Right) { 3798 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 3799 QualType Result 3800 = isComparison 3801 ? Context.BoolTy 3802 : Context.UsualArithmeticConversionsType(LandR[0], LandR[1]); 3803 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 3804 } 3805 } 3806 break; 3807 3808 case OO_Percent: 3809 BinaryAmp: 3810 case OO_Caret: 3811 case OO_Pipe: 3812 case OO_LessLess: 3813 case OO_GreaterGreater: 3814 // C++ [over.built]p17: 3815 // 3816 // For every pair of promoted integral types L and R, there 3817 // exist candidate operator functions of the form 3818 // 3819 // LR operator%(L, R); 3820 // LR operator&(L, R); 3821 // LR operator^(L, R); 3822 // LR operator|(L, R); 3823 // L operator<<(L, R); 3824 // L operator>>(L, R); 3825 // 3826 // where LR is the result of the usual arithmetic conversions 3827 // between types L and R. 3828 for (unsigned Left = FirstPromotedIntegralType; 3829 Left < LastPromotedIntegralType; ++Left) { 3830 for (unsigned Right = FirstPromotedIntegralType; 3831 Right < LastPromotedIntegralType; ++Right) { 3832 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 3833 QualType Result = (Op == OO_LessLess || Op == OO_GreaterGreater) 3834 ? LandR[0] 3835 : Context.UsualArithmeticConversionsType(LandR[0], LandR[1]); 3836 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 3837 } 3838 } 3839 break; 3840 3841 case OO_Equal: 3842 // C++ [over.built]p20: 3843 // 3844 // For every pair (T, VQ), where T is an enumeration or 3845 // pointer to member type and VQ is either volatile or 3846 // empty, there exist candidate operator functions of the form 3847 // 3848 // VQ T& operator=(VQ T&, T); 3849 for (BuiltinCandidateTypeSet::iterator 3850 Enum = CandidateTypes.enumeration_begin(), 3851 EnumEnd = CandidateTypes.enumeration_end(); 3852 Enum != EnumEnd; ++Enum) 3853 AddBuiltinAssignmentOperatorCandidates(*this, *Enum, Args, 2, 3854 CandidateSet); 3855 for (BuiltinCandidateTypeSet::iterator 3856 MemPtr = CandidateTypes.member_pointer_begin(), 3857 MemPtrEnd = CandidateTypes.member_pointer_end(); 3858 MemPtr != MemPtrEnd; ++MemPtr) 3859 AddBuiltinAssignmentOperatorCandidates(*this, *MemPtr, Args, 2, 3860 CandidateSet); 3861 // Fall through. 3862 3863 case OO_PlusEqual: 3864 case OO_MinusEqual: 3865 // C++ [over.built]p19: 3866 // 3867 // For every pair (T, VQ), where T is any type and VQ is either 3868 // volatile or empty, there exist candidate operator functions 3869 // of the form 3870 // 3871 // T*VQ& operator=(T*VQ&, T*); 3872 // 3873 // C++ [over.built]p21: 3874 // 3875 // For every pair (T, VQ), where T is a cv-qualified or 3876 // cv-unqualified object type and VQ is either volatile or 3877 // empty, there exist candidate operator functions of the form 3878 // 3879 // T*VQ& operator+=(T*VQ&, ptrdiff_t); 3880 // T*VQ& operator-=(T*VQ&, ptrdiff_t); 3881 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3882 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3883 QualType ParamTypes[2]; 3884 ParamTypes[1] = (Op == OO_Equal)? *Ptr : Context.getPointerDiffType(); 3885 3886 // non-volatile version 3887 ParamTypes[0] = Context.getLValueReferenceType(*Ptr); 3888 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3889 /*IsAssigmentOperator=*/Op == OO_Equal); 3890 3891 if (!Context.getCanonicalType(*Ptr).isVolatileQualified() && 3892 VisibleTypeConversionsQuals.hasVolatile()) { 3893 // volatile version 3894 ParamTypes[0] 3895 = Context.getLValueReferenceType(Context.getVolatileType(*Ptr)); 3896 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3897 /*IsAssigmentOperator=*/Op == OO_Equal); 3898 } 3899 } 3900 // Fall through. 3901 3902 case OO_StarEqual: 3903 case OO_SlashEqual: 3904 // C++ [over.built]p18: 3905 // 3906 // For every triple (L, VQ, R), where L is an arithmetic type, 3907 // VQ is either volatile or empty, and R is a promoted 3908 // arithmetic type, there exist candidate operator functions of 3909 // the form 3910 // 3911 // VQ L& operator=(VQ L&, R); 3912 // VQ L& operator*=(VQ L&, R); 3913 // VQ L& operator/=(VQ L&, R); 3914 // VQ L& operator+=(VQ L&, R); 3915 // VQ L& operator-=(VQ L&, R); 3916 for (unsigned Left = 0; Left < NumArithmeticTypes; ++Left) { 3917 for (unsigned Right = FirstPromotedArithmeticType; 3918 Right < LastPromotedArithmeticType; ++Right) { 3919 QualType ParamTypes[2]; 3920 ParamTypes[1] = ArithmeticTypes[Right]; 3921 3922 // Add this built-in operator as a candidate (VQ is empty). 3923 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 3924 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3925 /*IsAssigmentOperator=*/Op == OO_Equal); 3926 3927 // Add this built-in operator as a candidate (VQ is 'volatile'). 3928 if (VisibleTypeConversionsQuals.hasVolatile()) { 3929 ParamTypes[0] = Context.getVolatileType(ArithmeticTypes[Left]); 3930 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 3931 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3932 /*IsAssigmentOperator=*/Op == OO_Equal); 3933 } 3934 } 3935 } 3936 break; 3937 3938 case OO_PercentEqual: 3939 case OO_LessLessEqual: 3940 case OO_GreaterGreaterEqual: 3941 case OO_AmpEqual: 3942 case OO_CaretEqual: 3943 case OO_PipeEqual: 3944 // C++ [over.built]p22: 3945 // 3946 // For every triple (L, VQ, R), where L is an integral type, VQ 3947 // is either volatile or empty, and R is a promoted integral 3948 // type, there exist candidate operator functions of the form 3949 // 3950 // VQ L& operator%=(VQ L&, R); 3951 // VQ L& operator<<=(VQ L&, R); 3952 // VQ L& operator>>=(VQ L&, R); 3953 // VQ L& operator&=(VQ L&, R); 3954 // VQ L& operator^=(VQ L&, R); 3955 // VQ L& operator|=(VQ L&, R); 3956 for (unsigned Left = FirstIntegralType; Left < LastIntegralType; ++Left) { 3957 for (unsigned Right = FirstPromotedIntegralType; 3958 Right < LastPromotedIntegralType; ++Right) { 3959 QualType ParamTypes[2]; 3960 ParamTypes[1] = ArithmeticTypes[Right]; 3961 3962 // Add this built-in operator as a candidate (VQ is empty). 3963 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 3964 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 3965 if (VisibleTypeConversionsQuals.hasVolatile()) { 3966 // Add this built-in operator as a candidate (VQ is 'volatile'). 3967 ParamTypes[0] = ArithmeticTypes[Left]; 3968 ParamTypes[0] = Context.getVolatileType(ParamTypes[0]); 3969 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 3970 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 3971 } 3972 } 3973 } 3974 break; 3975 3976 case OO_Exclaim: { 3977 // C++ [over.operator]p23: 3978 // 3979 // There also exist candidate operator functions of the form 3980 // 3981 // bool operator!(bool); 3982 // bool operator&&(bool, bool); [BELOW] 3983 // bool operator||(bool, bool); [BELOW] 3984 QualType ParamTy = Context.BoolTy; 3985 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet, 3986 /*IsAssignmentOperator=*/false, 3987 /*NumContextualBoolArguments=*/1); 3988 break; 3989 } 3990 3991 case OO_AmpAmp: 3992 case OO_PipePipe: { 3993 // C++ [over.operator]p23: 3994 // 3995 // There also exist candidate operator functions of the form 3996 // 3997 // bool operator!(bool); [ABOVE] 3998 // bool operator&&(bool, bool); 3999 // bool operator||(bool, bool); 4000 QualType ParamTypes[2] = { Context.BoolTy, Context.BoolTy }; 4001 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet, 4002 /*IsAssignmentOperator=*/false, 4003 /*NumContextualBoolArguments=*/2); 4004 break; 4005 } 4006 4007 case OO_Subscript: 4008 // C++ [over.built]p13: 4009 // 4010 // For every cv-qualified or cv-unqualified object type T there 4011 // exist candidate operator functions of the form 4012 // 4013 // T* operator+(T*, ptrdiff_t); [ABOVE] 4014 // T& operator[](T*, ptrdiff_t); 4015 // T* operator-(T*, ptrdiff_t); [ABOVE] 4016 // T* operator+(ptrdiff_t, T*); [ABOVE] 4017 // T& operator[](ptrdiff_t, T*); 4018 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 4019 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4020 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 4021 QualType PointeeType = (*Ptr)->getAs<PointerType>()->getPointeeType(); 4022 QualType ResultTy = Context.getLValueReferenceType(PointeeType); 4023 4024 // T& operator[](T*, ptrdiff_t) 4025 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 4026 4027 // T& operator[](ptrdiff_t, T*); 4028 ParamTypes[0] = ParamTypes[1]; 4029 ParamTypes[1] = *Ptr; 4030 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 4031 } 4032 break; 4033 4034 case OO_ArrowStar: 4035 // C++ [over.built]p11: 4036 // For every quintuple (C1, C2, T, CV1, CV2), where C2 is a class type, 4037 // C1 is the same type as C2 or is a derived class of C2, T is an object 4038 // type or a function type, and CV1 and CV2 are cv-qualifier-seqs, 4039 // there exist candidate operator functions of the form 4040 // CV12 T& operator->*(CV1 C1*, CV2 T C2::*); 4041 // where CV12 is the union of CV1 and CV2. 4042 { 4043 for (BuiltinCandidateTypeSet::iterator Ptr = 4044 CandidateTypes.pointer_begin(); 4045 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4046 QualType C1Ty = (*Ptr); 4047 QualType C1; 4048 QualifierCollector Q1; 4049 if (const PointerType *PointerTy = C1Ty->getAs<PointerType>()) { 4050 C1 = QualType(Q1.strip(PointerTy->getPointeeType()), 0); 4051 if (!isa<RecordType>(C1)) 4052 continue; 4053 // heuristic to reduce number of builtin candidates in the set. 4054 // Add volatile/restrict version only if there are conversions to a 4055 // volatile/restrict type. 4056 if (!VisibleTypeConversionsQuals.hasVolatile() && Q1.hasVolatile()) 4057 continue; 4058 if (!VisibleTypeConversionsQuals.hasRestrict() && Q1.hasRestrict()) 4059 continue; 4060 } 4061 for (BuiltinCandidateTypeSet::iterator 4062 MemPtr = CandidateTypes.member_pointer_begin(), 4063 MemPtrEnd = CandidateTypes.member_pointer_end(); 4064 MemPtr != MemPtrEnd; ++MemPtr) { 4065 const MemberPointerType *mptr = cast<MemberPointerType>(*MemPtr); 4066 QualType C2 = QualType(mptr->getClass(), 0); 4067 C2 = C2.getUnqualifiedType(); 4068 if (C1 != C2 && !IsDerivedFrom(C1, C2)) 4069 break; 4070 QualType ParamTypes[2] = { *Ptr, *MemPtr }; 4071 // build CV12 T& 4072 QualType T = mptr->getPointeeType(); 4073 if (!VisibleTypeConversionsQuals.hasVolatile() && 4074 T.isVolatileQualified()) 4075 continue; 4076 if (!VisibleTypeConversionsQuals.hasRestrict() && 4077 T.isRestrictQualified()) 4078 continue; 4079 T = Q1.apply(T); 4080 QualType ResultTy = Context.getLValueReferenceType(T); 4081 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 4082 } 4083 } 4084 } 4085 break; 4086 4087 case OO_Conditional: 4088 // Note that we don't consider the first argument, since it has been 4089 // contextually converted to bool long ago. The candidates below are 4090 // therefore added as binary. 4091 // 4092 // C++ [over.built]p24: 4093 // For every type T, where T is a pointer or pointer-to-member type, 4094 // there exist candidate operator functions of the form 4095 // 4096 // T operator?(bool, T, T); 4097 // 4098 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(), 4099 E = CandidateTypes.pointer_end(); Ptr != E; ++Ptr) { 4100 QualType ParamTypes[2] = { *Ptr, *Ptr }; 4101 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 4102 } 4103 for (BuiltinCandidateTypeSet::iterator Ptr = 4104 CandidateTypes.member_pointer_begin(), 4105 E = CandidateTypes.member_pointer_end(); Ptr != E; ++Ptr) { 4106 QualType ParamTypes[2] = { *Ptr, *Ptr }; 4107 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 4108 } 4109 goto Conditional; 4110 } 4111} 4112 4113/// \brief Add function candidates found via argument-dependent lookup 4114/// to the set of overloading candidates. 4115/// 4116/// This routine performs argument-dependent name lookup based on the 4117/// given function name (which may also be an operator name) and adds 4118/// all of the overload candidates found by ADL to the overload 4119/// candidate set (C++ [basic.lookup.argdep]). 4120void 4121Sema::AddArgumentDependentLookupCandidates(DeclarationName Name, 4122 bool Operator, 4123 Expr **Args, unsigned NumArgs, 4124 const TemplateArgumentListInfo *ExplicitTemplateArgs, 4125 OverloadCandidateSet& CandidateSet, 4126 bool PartialOverloading) { 4127 ADLResult Fns; 4128 4129 // FIXME: This approach for uniquing ADL results (and removing 4130 // redundant candidates from the set) relies on pointer-equality, 4131 // which means we need to key off the canonical decl. However, 4132 // always going back to the canonical decl might not get us the 4133 // right set of default arguments. What default arguments are 4134 // we supposed to consider on ADL candidates, anyway? 4135 4136 // FIXME: Pass in the explicit template arguments? 4137 ArgumentDependentLookup(Name, Operator, Args, NumArgs, Fns); 4138 4139 // Erase all of the candidates we already knew about. 4140 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 4141 CandEnd = CandidateSet.end(); 4142 Cand != CandEnd; ++Cand) 4143 if (Cand->Function) { 4144 Fns.erase(Cand->Function); 4145 if (FunctionTemplateDecl *FunTmpl = Cand->Function->getPrimaryTemplate()) 4146 Fns.erase(FunTmpl); 4147 } 4148 4149 // For each of the ADL candidates we found, add it to the overload 4150 // set. 4151 for (ADLResult::iterator I = Fns.begin(), E = Fns.end(); I != E; ++I) { 4152 DeclAccessPair FoundDecl = DeclAccessPair::make(*I, AS_none); 4153 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*I)) { 4154 if (ExplicitTemplateArgs) 4155 continue; 4156 4157 AddOverloadCandidate(FD, FoundDecl, Args, NumArgs, CandidateSet, 4158 false, false, PartialOverloading); 4159 } else 4160 AddTemplateOverloadCandidate(cast<FunctionTemplateDecl>(*I), 4161 FoundDecl, ExplicitTemplateArgs, 4162 Args, NumArgs, CandidateSet); 4163 } 4164} 4165 4166/// isBetterOverloadCandidate - Determines whether the first overload 4167/// candidate is a better candidate than the second (C++ 13.3.3p1). 4168bool 4169Sema::isBetterOverloadCandidate(const OverloadCandidate& Cand1, 4170 const OverloadCandidate& Cand2, 4171 SourceLocation Loc) { 4172 // Define viable functions to be better candidates than non-viable 4173 // functions. 4174 if (!Cand2.Viable) 4175 return Cand1.Viable; 4176 else if (!Cand1.Viable) 4177 return false; 4178 4179 // C++ [over.match.best]p1: 4180 // 4181 // -- if F is a static member function, ICS1(F) is defined such 4182 // that ICS1(F) is neither better nor worse than ICS1(G) for 4183 // any function G, and, symmetrically, ICS1(G) is neither 4184 // better nor worse than ICS1(F). 4185 unsigned StartArg = 0; 4186 if (Cand1.IgnoreObjectArgument || Cand2.IgnoreObjectArgument) 4187 StartArg = 1; 4188 4189 // C++ [over.match.best]p1: 4190 // A viable function F1 is defined to be a better function than another 4191 // viable function F2 if for all arguments i, ICSi(F1) is not a worse 4192 // conversion sequence than ICSi(F2), and then... 4193 unsigned NumArgs = Cand1.Conversions.size(); 4194 assert(Cand2.Conversions.size() == NumArgs && "Overload candidate mismatch"); 4195 bool HasBetterConversion = false; 4196 for (unsigned ArgIdx = StartArg; ArgIdx < NumArgs; ++ArgIdx) { 4197 switch (CompareImplicitConversionSequences(Cand1.Conversions[ArgIdx], 4198 Cand2.Conversions[ArgIdx])) { 4199 case ImplicitConversionSequence::Better: 4200 // Cand1 has a better conversion sequence. 4201 HasBetterConversion = true; 4202 break; 4203 4204 case ImplicitConversionSequence::Worse: 4205 // Cand1 can't be better than Cand2. 4206 return false; 4207 4208 case ImplicitConversionSequence::Indistinguishable: 4209 // Do nothing. 4210 break; 4211 } 4212 } 4213 4214 // -- for some argument j, ICSj(F1) is a better conversion sequence than 4215 // ICSj(F2), or, if not that, 4216 if (HasBetterConversion) 4217 return true; 4218 4219 // - F1 is a non-template function and F2 is a function template 4220 // specialization, or, if not that, 4221 if (Cand1.Function && !Cand1.Function->getPrimaryTemplate() && 4222 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 4223 return true; 4224 4225 // -- F1 and F2 are function template specializations, and the function 4226 // template for F1 is more specialized than the template for F2 4227 // according to the partial ordering rules described in 14.5.5.2, or, 4228 // if not that, 4229 if (Cand1.Function && Cand1.Function->getPrimaryTemplate() && 4230 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 4231 if (FunctionTemplateDecl *BetterTemplate 4232 = getMoreSpecializedTemplate(Cand1.Function->getPrimaryTemplate(), 4233 Cand2.Function->getPrimaryTemplate(), 4234 Loc, 4235 isa<CXXConversionDecl>(Cand1.Function)? TPOC_Conversion 4236 : TPOC_Call)) 4237 return BetterTemplate == Cand1.Function->getPrimaryTemplate(); 4238 4239 // -- the context is an initialization by user-defined conversion 4240 // (see 8.5, 13.3.1.5) and the standard conversion sequence 4241 // from the return type of F1 to the destination type (i.e., 4242 // the type of the entity being initialized) is a better 4243 // conversion sequence than the standard conversion sequence 4244 // from the return type of F2 to the destination type. 4245 if (Cand1.Function && Cand2.Function && 4246 isa<CXXConversionDecl>(Cand1.Function) && 4247 isa<CXXConversionDecl>(Cand2.Function)) { 4248 switch (CompareStandardConversionSequences(Cand1.FinalConversion, 4249 Cand2.FinalConversion)) { 4250 case ImplicitConversionSequence::Better: 4251 // Cand1 has a better conversion sequence. 4252 return true; 4253 4254 case ImplicitConversionSequence::Worse: 4255 // Cand1 can't be better than Cand2. 4256 return false; 4257 4258 case ImplicitConversionSequence::Indistinguishable: 4259 // Do nothing 4260 break; 4261 } 4262 } 4263 4264 return false; 4265} 4266 4267/// \brief Computes the best viable function (C++ 13.3.3) 4268/// within an overload candidate set. 4269/// 4270/// \param CandidateSet the set of candidate functions. 4271/// 4272/// \param Loc the location of the function name (or operator symbol) for 4273/// which overload resolution occurs. 4274/// 4275/// \param Best f overload resolution was successful or found a deleted 4276/// function, Best points to the candidate function found. 4277/// 4278/// \returns The result of overload resolution. 4279OverloadingResult Sema::BestViableFunction(OverloadCandidateSet& CandidateSet, 4280 SourceLocation Loc, 4281 OverloadCandidateSet::iterator& Best) { 4282 // Find the best viable function. 4283 Best = CandidateSet.end(); 4284 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 4285 Cand != CandidateSet.end(); ++Cand) { 4286 if (Cand->Viable) { 4287 if (Best == CandidateSet.end() || 4288 isBetterOverloadCandidate(*Cand, *Best, Loc)) 4289 Best = Cand; 4290 } 4291 } 4292 4293 // If we didn't find any viable functions, abort. 4294 if (Best == CandidateSet.end()) 4295 return OR_No_Viable_Function; 4296 4297 // Make sure that this function is better than every other viable 4298 // function. If not, we have an ambiguity. 4299 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 4300 Cand != CandidateSet.end(); ++Cand) { 4301 if (Cand->Viable && 4302 Cand != Best && 4303 !isBetterOverloadCandidate(*Best, *Cand, Loc)) { 4304 Best = CandidateSet.end(); 4305 return OR_Ambiguous; 4306 } 4307 } 4308 4309 // Best is the best viable function. 4310 if (Best->Function && 4311 (Best->Function->isDeleted() || 4312 Best->Function->getAttr<UnavailableAttr>())) 4313 return OR_Deleted; 4314 4315 // C++ [basic.def.odr]p2: 4316 // An overloaded function is used if it is selected by overload resolution 4317 // when referred to from a potentially-evaluated expression. [Note: this 4318 // covers calls to named functions (5.2.2), operator overloading 4319 // (clause 13), user-defined conversions (12.3.2), allocation function for 4320 // placement new (5.3.4), as well as non-default initialization (8.5). 4321 if (Best->Function) 4322 MarkDeclarationReferenced(Loc, Best->Function); 4323 return OR_Success; 4324} 4325 4326namespace { 4327 4328enum OverloadCandidateKind { 4329 oc_function, 4330 oc_method, 4331 oc_constructor, 4332 oc_function_template, 4333 oc_method_template, 4334 oc_constructor_template, 4335 oc_implicit_default_constructor, 4336 oc_implicit_copy_constructor, 4337 oc_implicit_copy_assignment 4338}; 4339 4340OverloadCandidateKind ClassifyOverloadCandidate(Sema &S, 4341 FunctionDecl *Fn, 4342 std::string &Description) { 4343 bool isTemplate = false; 4344 4345 if (FunctionTemplateDecl *FunTmpl = Fn->getPrimaryTemplate()) { 4346 isTemplate = true; 4347 Description = S.getTemplateArgumentBindingsText( 4348 FunTmpl->getTemplateParameters(), *Fn->getTemplateSpecializationArgs()); 4349 } 4350 4351 if (CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(Fn)) { 4352 if (!Ctor->isImplicit()) 4353 return isTemplate ? oc_constructor_template : oc_constructor; 4354 4355 return Ctor->isCopyConstructor() ? oc_implicit_copy_constructor 4356 : oc_implicit_default_constructor; 4357 } 4358 4359 if (CXXMethodDecl *Meth = dyn_cast<CXXMethodDecl>(Fn)) { 4360 // This actually gets spelled 'candidate function' for now, but 4361 // it doesn't hurt to split it out. 4362 if (!Meth->isImplicit()) 4363 return isTemplate ? oc_method_template : oc_method; 4364 4365 assert(Meth->isCopyAssignment() 4366 && "implicit method is not copy assignment operator?"); 4367 return oc_implicit_copy_assignment; 4368 } 4369 4370 return isTemplate ? oc_function_template : oc_function; 4371} 4372 4373} // end anonymous namespace 4374 4375// Notes the location of an overload candidate. 4376void Sema::NoteOverloadCandidate(FunctionDecl *Fn) { 4377 std::string FnDesc; 4378 OverloadCandidateKind K = ClassifyOverloadCandidate(*this, Fn, FnDesc); 4379 Diag(Fn->getLocation(), diag::note_ovl_candidate) 4380 << (unsigned) K << FnDesc; 4381} 4382 4383/// Diagnoses an ambiguous conversion. The partial diagnostic is the 4384/// "lead" diagnostic; it will be given two arguments, the source and 4385/// target types of the conversion. 4386void Sema::DiagnoseAmbiguousConversion(const ImplicitConversionSequence &ICS, 4387 SourceLocation CaretLoc, 4388 const PartialDiagnostic &PDiag) { 4389 Diag(CaretLoc, PDiag) 4390 << ICS.Ambiguous.getFromType() << ICS.Ambiguous.getToType(); 4391 for (AmbiguousConversionSequence::const_iterator 4392 I = ICS.Ambiguous.begin(), E = ICS.Ambiguous.end(); I != E; ++I) { 4393 NoteOverloadCandidate(*I); 4394 } 4395} 4396 4397namespace { 4398 4399void DiagnoseBadConversion(Sema &S, OverloadCandidate *Cand, unsigned I) { 4400 const ImplicitConversionSequence &Conv = Cand->Conversions[I]; 4401 assert(Conv.isBad()); 4402 assert(Cand->Function && "for now, candidate must be a function"); 4403 FunctionDecl *Fn = Cand->Function; 4404 4405 // There's a conversion slot for the object argument if this is a 4406 // non-constructor method. Note that 'I' corresponds the 4407 // conversion-slot index. 4408 bool isObjectArgument = false; 4409 if (isa<CXXMethodDecl>(Fn) && !isa<CXXConstructorDecl>(Fn)) { 4410 if (I == 0) 4411 isObjectArgument = true; 4412 else 4413 I--; 4414 } 4415 4416 std::string FnDesc; 4417 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, FnDesc); 4418 4419 Expr *FromExpr = Conv.Bad.FromExpr; 4420 QualType FromTy = Conv.Bad.getFromType(); 4421 QualType ToTy = Conv.Bad.getToType(); 4422 4423 if (FromTy == S.Context.OverloadTy) { 4424 assert(FromExpr && "overload set argument came from implicit argument?"); 4425 Expr *E = FromExpr->IgnoreParens(); 4426 if (isa<UnaryOperator>(E)) 4427 E = cast<UnaryOperator>(E)->getSubExpr()->IgnoreParens(); 4428 DeclarationName Name = cast<OverloadExpr>(E)->getName(); 4429 4430 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_overload) 4431 << (unsigned) FnKind << FnDesc 4432 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 4433 << ToTy << Name << I+1; 4434 return; 4435 } 4436 4437 // Do some hand-waving analysis to see if the non-viability is due 4438 // to a qualifier mismatch. 4439 CanQualType CFromTy = S.Context.getCanonicalType(FromTy); 4440 CanQualType CToTy = S.Context.getCanonicalType(ToTy); 4441 if (CanQual<ReferenceType> RT = CToTy->getAs<ReferenceType>()) 4442 CToTy = RT->getPointeeType(); 4443 else { 4444 // TODO: detect and diagnose the full richness of const mismatches. 4445 if (CanQual<PointerType> FromPT = CFromTy->getAs<PointerType>()) 4446 if (CanQual<PointerType> ToPT = CToTy->getAs<PointerType>()) 4447 CFromTy = FromPT->getPointeeType(), CToTy = ToPT->getPointeeType(); 4448 } 4449 4450 if (CToTy.getUnqualifiedType() == CFromTy.getUnqualifiedType() && 4451 !CToTy.isAtLeastAsQualifiedAs(CFromTy)) { 4452 // It is dumb that we have to do this here. 4453 while (isa<ArrayType>(CFromTy)) 4454 CFromTy = CFromTy->getAs<ArrayType>()->getElementType(); 4455 while (isa<ArrayType>(CToTy)) 4456 CToTy = CFromTy->getAs<ArrayType>()->getElementType(); 4457 4458 Qualifiers FromQs = CFromTy.getQualifiers(); 4459 Qualifiers ToQs = CToTy.getQualifiers(); 4460 4461 if (FromQs.getAddressSpace() != ToQs.getAddressSpace()) { 4462 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_addrspace) 4463 << (unsigned) FnKind << FnDesc 4464 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 4465 << FromTy 4466 << FromQs.getAddressSpace() << ToQs.getAddressSpace() 4467 << (unsigned) isObjectArgument << I+1; 4468 return; 4469 } 4470 4471 unsigned CVR = FromQs.getCVRQualifiers() & ~ToQs.getCVRQualifiers(); 4472 assert(CVR && "unexpected qualifiers mismatch"); 4473 4474 if (isObjectArgument) { 4475 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr_this) 4476 << (unsigned) FnKind << FnDesc 4477 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 4478 << FromTy << (CVR - 1); 4479 } else { 4480 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr) 4481 << (unsigned) FnKind << FnDesc 4482 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 4483 << FromTy << (CVR - 1) << I+1; 4484 } 4485 return; 4486 } 4487 4488 // Diagnose references or pointers to incomplete types differently, 4489 // since it's far from impossible that the incompleteness triggered 4490 // the failure. 4491 QualType TempFromTy = FromTy.getNonReferenceType(); 4492 if (const PointerType *PTy = TempFromTy->getAs<PointerType>()) 4493 TempFromTy = PTy->getPointeeType(); 4494 if (TempFromTy->isIncompleteType()) { 4495 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_conv_incomplete) 4496 << (unsigned) FnKind << FnDesc 4497 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 4498 << FromTy << ToTy << (unsigned) isObjectArgument << I+1; 4499 return; 4500 } 4501 4502 // TODO: specialize more based on the kind of mismatch 4503 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_conv) 4504 << (unsigned) FnKind << FnDesc 4505 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 4506 << FromTy << ToTy << (unsigned) isObjectArgument << I+1; 4507} 4508 4509void DiagnoseArityMismatch(Sema &S, OverloadCandidate *Cand, 4510 unsigned NumFormalArgs) { 4511 // TODO: treat calls to a missing default constructor as a special case 4512 4513 FunctionDecl *Fn = Cand->Function; 4514 const FunctionProtoType *FnTy = Fn->getType()->getAs<FunctionProtoType>(); 4515 4516 unsigned MinParams = Fn->getMinRequiredArguments(); 4517 4518 // at least / at most / exactly 4519 unsigned mode, modeCount; 4520 if (NumFormalArgs < MinParams) { 4521 assert(Cand->FailureKind == ovl_fail_too_few_arguments); 4522 if (MinParams != FnTy->getNumArgs() || FnTy->isVariadic()) 4523 mode = 0; // "at least" 4524 else 4525 mode = 2; // "exactly" 4526 modeCount = MinParams; 4527 } else { 4528 assert(Cand->FailureKind == ovl_fail_too_many_arguments); 4529 if (MinParams != FnTy->getNumArgs()) 4530 mode = 1; // "at most" 4531 else 4532 mode = 2; // "exactly" 4533 modeCount = FnTy->getNumArgs(); 4534 } 4535 4536 std::string Description; 4537 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, Description); 4538 4539 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_arity) 4540 << (unsigned) FnKind << Description << mode << modeCount << NumFormalArgs; 4541} 4542 4543/// Diagnose a failed template-argument deduction. 4544void DiagnoseBadDeduction(Sema &S, OverloadCandidate *Cand, 4545 Expr **Args, unsigned NumArgs) { 4546 FunctionDecl *Fn = Cand->Function; // pattern 4547 4548 TemplateParameter Param = TemplateParameter::getFromOpaqueValue( 4549 Cand->DeductionFailure.TemplateParameter); 4550 4551 switch (Cand->DeductionFailure.Result) { 4552 case Sema::TDK_Success: 4553 llvm_unreachable("TDK_success while diagnosing bad deduction"); 4554 4555 case Sema::TDK_Incomplete: { 4556 NamedDecl *ParamD; 4557 (ParamD = Param.dyn_cast<TemplateTypeParmDecl*>()) || 4558 (ParamD = Param.dyn_cast<NonTypeTemplateParmDecl*>()) || 4559 (ParamD = Param.dyn_cast<TemplateTemplateParmDecl*>()); 4560 assert(ParamD && "no parameter found for incomplete deduction result"); 4561 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_incomplete_deduction) 4562 << ParamD->getDeclName(); 4563 return; 4564 } 4565 4566 // TODO: diagnose these individually, then kill off 4567 // note_ovl_candidate_bad_deduction, which is uselessly vague. 4568 case Sema::TDK_InstantiationDepth: 4569 case Sema::TDK_Inconsistent: 4570 case Sema::TDK_InconsistentQuals: 4571 case Sema::TDK_SubstitutionFailure: 4572 case Sema::TDK_NonDeducedMismatch: 4573 case Sema::TDK_TooManyArguments: 4574 case Sema::TDK_TooFewArguments: 4575 case Sema::TDK_InvalidExplicitArguments: 4576 case Sema::TDK_FailedOverloadResolution: 4577 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_deduction); 4578 return; 4579 } 4580} 4581 4582/// Generates a 'note' diagnostic for an overload candidate. We've 4583/// already generated a primary error at the call site. 4584/// 4585/// It really does need to be a single diagnostic with its caret 4586/// pointed at the candidate declaration. Yes, this creates some 4587/// major challenges of technical writing. Yes, this makes pointing 4588/// out problems with specific arguments quite awkward. It's still 4589/// better than generating twenty screens of text for every failed 4590/// overload. 4591/// 4592/// It would be great to be able to express per-candidate problems 4593/// more richly for those diagnostic clients that cared, but we'd 4594/// still have to be just as careful with the default diagnostics. 4595void NoteFunctionCandidate(Sema &S, OverloadCandidate *Cand, 4596 Expr **Args, unsigned NumArgs) { 4597 FunctionDecl *Fn = Cand->Function; 4598 4599 // Note deleted candidates, but only if they're viable. 4600 if (Cand->Viable && (Fn->isDeleted() || Fn->hasAttr<UnavailableAttr>())) { 4601 std::string FnDesc; 4602 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, FnDesc); 4603 4604 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_deleted) 4605 << FnKind << FnDesc << Fn->isDeleted(); 4606 return; 4607 } 4608 4609 // We don't really have anything else to say about viable candidates. 4610 if (Cand->Viable) { 4611 S.NoteOverloadCandidate(Fn); 4612 return; 4613 } 4614 4615 switch (Cand->FailureKind) { 4616 case ovl_fail_too_many_arguments: 4617 case ovl_fail_too_few_arguments: 4618 return DiagnoseArityMismatch(S, Cand, NumArgs); 4619 4620 case ovl_fail_bad_deduction: 4621 return DiagnoseBadDeduction(S, Cand, Args, NumArgs); 4622 4623 case ovl_fail_trivial_conversion: 4624 case ovl_fail_bad_final_conversion: 4625 return S.NoteOverloadCandidate(Fn); 4626 4627 case ovl_fail_bad_conversion: { 4628 unsigned I = (Cand->IgnoreObjectArgument ? 1 : 0); 4629 for (unsigned N = Cand->Conversions.size(); I != N; ++I) 4630 if (Cand->Conversions[I].isBad()) 4631 return DiagnoseBadConversion(S, Cand, I); 4632 4633 // FIXME: this currently happens when we're called from SemaInit 4634 // when user-conversion overload fails. Figure out how to handle 4635 // those conditions and diagnose them well. 4636 return S.NoteOverloadCandidate(Fn); 4637 } 4638 } 4639} 4640 4641void NoteSurrogateCandidate(Sema &S, OverloadCandidate *Cand) { 4642 // Desugar the type of the surrogate down to a function type, 4643 // retaining as many typedefs as possible while still showing 4644 // the function type (and, therefore, its parameter types). 4645 QualType FnType = Cand->Surrogate->getConversionType(); 4646 bool isLValueReference = false; 4647 bool isRValueReference = false; 4648 bool isPointer = false; 4649 if (const LValueReferenceType *FnTypeRef = 4650 FnType->getAs<LValueReferenceType>()) { 4651 FnType = FnTypeRef->getPointeeType(); 4652 isLValueReference = true; 4653 } else if (const RValueReferenceType *FnTypeRef = 4654 FnType->getAs<RValueReferenceType>()) { 4655 FnType = FnTypeRef->getPointeeType(); 4656 isRValueReference = true; 4657 } 4658 if (const PointerType *FnTypePtr = FnType->getAs<PointerType>()) { 4659 FnType = FnTypePtr->getPointeeType(); 4660 isPointer = true; 4661 } 4662 // Desugar down to a function type. 4663 FnType = QualType(FnType->getAs<FunctionType>(), 0); 4664 // Reconstruct the pointer/reference as appropriate. 4665 if (isPointer) FnType = S.Context.getPointerType(FnType); 4666 if (isRValueReference) FnType = S.Context.getRValueReferenceType(FnType); 4667 if (isLValueReference) FnType = S.Context.getLValueReferenceType(FnType); 4668 4669 S.Diag(Cand->Surrogate->getLocation(), diag::note_ovl_surrogate_cand) 4670 << FnType; 4671} 4672 4673void NoteBuiltinOperatorCandidate(Sema &S, 4674 const char *Opc, 4675 SourceLocation OpLoc, 4676 OverloadCandidate *Cand) { 4677 assert(Cand->Conversions.size() <= 2 && "builtin operator is not binary"); 4678 std::string TypeStr("operator"); 4679 TypeStr += Opc; 4680 TypeStr += "("; 4681 TypeStr += Cand->BuiltinTypes.ParamTypes[0].getAsString(); 4682 if (Cand->Conversions.size() == 1) { 4683 TypeStr += ")"; 4684 S.Diag(OpLoc, diag::note_ovl_builtin_unary_candidate) << TypeStr; 4685 } else { 4686 TypeStr += ", "; 4687 TypeStr += Cand->BuiltinTypes.ParamTypes[1].getAsString(); 4688 TypeStr += ")"; 4689 S.Diag(OpLoc, diag::note_ovl_builtin_binary_candidate) << TypeStr; 4690 } 4691} 4692 4693void NoteAmbiguousUserConversions(Sema &S, SourceLocation OpLoc, 4694 OverloadCandidate *Cand) { 4695 unsigned NoOperands = Cand->Conversions.size(); 4696 for (unsigned ArgIdx = 0; ArgIdx < NoOperands; ++ArgIdx) { 4697 const ImplicitConversionSequence &ICS = Cand->Conversions[ArgIdx]; 4698 if (ICS.isBad()) break; // all meaningless after first invalid 4699 if (!ICS.isAmbiguous()) continue; 4700 4701 S.DiagnoseAmbiguousConversion(ICS, OpLoc, 4702 S.PDiag(diag::note_ambiguous_type_conversion)); 4703 } 4704} 4705 4706SourceLocation GetLocationForCandidate(const OverloadCandidate *Cand) { 4707 if (Cand->Function) 4708 return Cand->Function->getLocation(); 4709 if (Cand->IsSurrogate) 4710 return Cand->Surrogate->getLocation(); 4711 return SourceLocation(); 4712} 4713 4714struct CompareOverloadCandidatesForDisplay { 4715 Sema &S; 4716 CompareOverloadCandidatesForDisplay(Sema &S) : S(S) {} 4717 4718 bool operator()(const OverloadCandidate *L, 4719 const OverloadCandidate *R) { 4720 // Fast-path this check. 4721 if (L == R) return false; 4722 4723 // Order first by viability. 4724 if (L->Viable) { 4725 if (!R->Viable) return true; 4726 4727 // TODO: introduce a tri-valued comparison for overload 4728 // candidates. Would be more worthwhile if we had a sort 4729 // that could exploit it. 4730 if (S.isBetterOverloadCandidate(*L, *R, SourceLocation())) return true; 4731 if (S.isBetterOverloadCandidate(*R, *L, SourceLocation())) return false; 4732 } else if (R->Viable) 4733 return false; 4734 4735 assert(L->Viable == R->Viable); 4736 4737 // Criteria by which we can sort non-viable candidates: 4738 if (!L->Viable) { 4739 // 1. Arity mismatches come after other candidates. 4740 if (L->FailureKind == ovl_fail_too_many_arguments || 4741 L->FailureKind == ovl_fail_too_few_arguments) 4742 return false; 4743 if (R->FailureKind == ovl_fail_too_many_arguments || 4744 R->FailureKind == ovl_fail_too_few_arguments) 4745 return true; 4746 4747 // 2. Bad conversions come first and are ordered by the number 4748 // of bad conversions and quality of good conversions. 4749 if (L->FailureKind == ovl_fail_bad_conversion) { 4750 if (R->FailureKind != ovl_fail_bad_conversion) 4751 return true; 4752 4753 // If there's any ordering between the defined conversions... 4754 // FIXME: this might not be transitive. 4755 assert(L->Conversions.size() == R->Conversions.size()); 4756 4757 int leftBetter = 0; 4758 unsigned I = (L->IgnoreObjectArgument || R->IgnoreObjectArgument); 4759 for (unsigned E = L->Conversions.size(); I != E; ++I) { 4760 switch (S.CompareImplicitConversionSequences(L->Conversions[I], 4761 R->Conversions[I])) { 4762 case ImplicitConversionSequence::Better: 4763 leftBetter++; 4764 break; 4765 4766 case ImplicitConversionSequence::Worse: 4767 leftBetter--; 4768 break; 4769 4770 case ImplicitConversionSequence::Indistinguishable: 4771 break; 4772 } 4773 } 4774 if (leftBetter > 0) return true; 4775 if (leftBetter < 0) return false; 4776 4777 } else if (R->FailureKind == ovl_fail_bad_conversion) 4778 return false; 4779 4780 // TODO: others? 4781 } 4782 4783 // Sort everything else by location. 4784 SourceLocation LLoc = GetLocationForCandidate(L); 4785 SourceLocation RLoc = GetLocationForCandidate(R); 4786 4787 // Put candidates without locations (e.g. builtins) at the end. 4788 if (LLoc.isInvalid()) return false; 4789 if (RLoc.isInvalid()) return true; 4790 4791 return S.SourceMgr.isBeforeInTranslationUnit(LLoc, RLoc); 4792 } 4793}; 4794 4795/// CompleteNonViableCandidate - Normally, overload resolution only 4796/// computes up to the first 4797void CompleteNonViableCandidate(Sema &S, OverloadCandidate *Cand, 4798 Expr **Args, unsigned NumArgs) { 4799 assert(!Cand->Viable); 4800 4801 // Don't do anything on failures other than bad conversion. 4802 if (Cand->FailureKind != ovl_fail_bad_conversion) return; 4803 4804 // Skip forward to the first bad conversion. 4805 unsigned ConvIdx = (Cand->IgnoreObjectArgument ? 1 : 0); 4806 unsigned ConvCount = Cand->Conversions.size(); 4807 while (true) { 4808 assert(ConvIdx != ConvCount && "no bad conversion in candidate"); 4809 ConvIdx++; 4810 if (Cand->Conversions[ConvIdx - 1].isBad()) 4811 break; 4812 } 4813 4814 if (ConvIdx == ConvCount) 4815 return; 4816 4817 assert(!Cand->Conversions[ConvIdx].isInitialized() && 4818 "remaining conversion is initialized?"); 4819 4820 // FIXME: these should probably be preserved from the overload 4821 // operation somehow. 4822 bool SuppressUserConversions = false; 4823 bool ForceRValue = false; 4824 4825 const FunctionProtoType* Proto; 4826 unsigned ArgIdx = ConvIdx; 4827 4828 if (Cand->IsSurrogate) { 4829 QualType ConvType 4830 = Cand->Surrogate->getConversionType().getNonReferenceType(); 4831 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 4832 ConvType = ConvPtrType->getPointeeType(); 4833 Proto = ConvType->getAs<FunctionProtoType>(); 4834 ArgIdx--; 4835 } else if (Cand->Function) { 4836 Proto = Cand->Function->getType()->getAs<FunctionProtoType>(); 4837 if (isa<CXXMethodDecl>(Cand->Function) && 4838 !isa<CXXConstructorDecl>(Cand->Function)) 4839 ArgIdx--; 4840 } else { 4841 // Builtin binary operator with a bad first conversion. 4842 assert(ConvCount <= 3); 4843 for (; ConvIdx != ConvCount; ++ConvIdx) 4844 Cand->Conversions[ConvIdx] 4845 = S.TryCopyInitialization(Args[ConvIdx], 4846 Cand->BuiltinTypes.ParamTypes[ConvIdx], 4847 SuppressUserConversions, ForceRValue, 4848 /*InOverloadResolution*/ true); 4849 return; 4850 } 4851 4852 // Fill in the rest of the conversions. 4853 unsigned NumArgsInProto = Proto->getNumArgs(); 4854 for (; ConvIdx != ConvCount; ++ConvIdx, ++ArgIdx) { 4855 if (ArgIdx < NumArgsInProto) 4856 Cand->Conversions[ConvIdx] 4857 = S.TryCopyInitialization(Args[ArgIdx], Proto->getArgType(ArgIdx), 4858 SuppressUserConversions, ForceRValue, 4859 /*InOverloadResolution=*/true); 4860 else 4861 Cand->Conversions[ConvIdx].setEllipsis(); 4862 } 4863} 4864 4865} // end anonymous namespace 4866 4867/// PrintOverloadCandidates - When overload resolution fails, prints 4868/// diagnostic messages containing the candidates in the candidate 4869/// set. 4870void 4871Sema::PrintOverloadCandidates(OverloadCandidateSet& CandidateSet, 4872 OverloadCandidateDisplayKind OCD, 4873 Expr **Args, unsigned NumArgs, 4874 const char *Opc, 4875 SourceLocation OpLoc) { 4876 // Sort the candidates by viability and position. Sorting directly would 4877 // be prohibitive, so we make a set of pointers and sort those. 4878 llvm::SmallVector<OverloadCandidate*, 32> Cands; 4879 if (OCD == OCD_AllCandidates) Cands.reserve(CandidateSet.size()); 4880 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 4881 LastCand = CandidateSet.end(); 4882 Cand != LastCand; ++Cand) { 4883 if (Cand->Viable) 4884 Cands.push_back(Cand); 4885 else if (OCD == OCD_AllCandidates) { 4886 CompleteNonViableCandidate(*this, Cand, Args, NumArgs); 4887 Cands.push_back(Cand); 4888 } 4889 } 4890 4891 std::sort(Cands.begin(), Cands.end(), 4892 CompareOverloadCandidatesForDisplay(*this)); 4893 4894 bool ReportedAmbiguousConversions = false; 4895 4896 llvm::SmallVectorImpl<OverloadCandidate*>::iterator I, E; 4897 for (I = Cands.begin(), E = Cands.end(); I != E; ++I) { 4898 OverloadCandidate *Cand = *I; 4899 4900 if (Cand->Function) 4901 NoteFunctionCandidate(*this, Cand, Args, NumArgs); 4902 else if (Cand->IsSurrogate) 4903 NoteSurrogateCandidate(*this, Cand); 4904 4905 // This a builtin candidate. We do not, in general, want to list 4906 // every possible builtin candidate. 4907 else if (Cand->Viable) { 4908 // Generally we only see ambiguities including viable builtin 4909 // operators if overload resolution got screwed up by an 4910 // ambiguous user-defined conversion. 4911 // 4912 // FIXME: It's quite possible for different conversions to see 4913 // different ambiguities, though. 4914 if (!ReportedAmbiguousConversions) { 4915 NoteAmbiguousUserConversions(*this, OpLoc, Cand); 4916 ReportedAmbiguousConversions = true; 4917 } 4918 4919 // If this is a viable builtin, print it. 4920 NoteBuiltinOperatorCandidate(*this, Opc, OpLoc, Cand); 4921 } 4922 } 4923} 4924 4925static bool CheckUnresolvedAccess(Sema &S, OverloadExpr *E, DeclAccessPair D) { 4926 if (isa<UnresolvedLookupExpr>(E)) 4927 return S.CheckUnresolvedLookupAccess(cast<UnresolvedLookupExpr>(E), D); 4928 4929 return S.CheckUnresolvedMemberAccess(cast<UnresolvedMemberExpr>(E), D); 4930} 4931 4932/// ResolveAddressOfOverloadedFunction - Try to resolve the address of 4933/// an overloaded function (C++ [over.over]), where @p From is an 4934/// expression with overloaded function type and @p ToType is the type 4935/// we're trying to resolve to. For example: 4936/// 4937/// @code 4938/// int f(double); 4939/// int f(int); 4940/// 4941/// int (*pfd)(double) = f; // selects f(double) 4942/// @endcode 4943/// 4944/// This routine returns the resulting FunctionDecl if it could be 4945/// resolved, and NULL otherwise. When @p Complain is true, this 4946/// routine will emit diagnostics if there is an error. 4947FunctionDecl * 4948Sema::ResolveAddressOfOverloadedFunction(Expr *From, QualType ToType, 4949 bool Complain, 4950 DeclAccessPair &FoundResult) { 4951 QualType FunctionType = ToType; 4952 bool IsMember = false; 4953 if (const PointerType *ToTypePtr = ToType->getAs<PointerType>()) 4954 FunctionType = ToTypePtr->getPointeeType(); 4955 else if (const ReferenceType *ToTypeRef = ToType->getAs<ReferenceType>()) 4956 FunctionType = ToTypeRef->getPointeeType(); 4957 else if (const MemberPointerType *MemTypePtr = 4958 ToType->getAs<MemberPointerType>()) { 4959 FunctionType = MemTypePtr->getPointeeType(); 4960 IsMember = true; 4961 } 4962 4963 // We only look at pointers or references to functions. 4964 FunctionType = Context.getCanonicalType(FunctionType).getUnqualifiedType(); 4965 if (!FunctionType->isFunctionType()) 4966 return 0; 4967 4968 // Find the actual overloaded function declaration. 4969 if (From->getType() != Context.OverloadTy) 4970 return 0; 4971 4972 // C++ [over.over]p1: 4973 // [...] [Note: any redundant set of parentheses surrounding the 4974 // overloaded function name is ignored (5.1). ] 4975 // C++ [over.over]p1: 4976 // [...] The overloaded function name can be preceded by the & 4977 // operator. 4978 OverloadExpr *OvlExpr = OverloadExpr::find(From).getPointer(); 4979 TemplateArgumentListInfo ETABuffer, *ExplicitTemplateArgs = 0; 4980 if (OvlExpr->hasExplicitTemplateArgs()) { 4981 OvlExpr->getExplicitTemplateArgs().copyInto(ETABuffer); 4982 ExplicitTemplateArgs = &ETABuffer; 4983 } 4984 4985 // Look through all of the overloaded functions, searching for one 4986 // whose type matches exactly. 4987 llvm::SmallVector<std::pair<DeclAccessPair, FunctionDecl*>, 4> Matches; 4988 bool FoundNonTemplateFunction = false; 4989 for (UnresolvedSetIterator I = OvlExpr->decls_begin(), 4990 E = OvlExpr->decls_end(); I != E; ++I) { 4991 // Look through any using declarations to find the underlying function. 4992 NamedDecl *Fn = (*I)->getUnderlyingDecl(); 4993 4994 // C++ [over.over]p3: 4995 // Non-member functions and static member functions match 4996 // targets of type "pointer-to-function" or "reference-to-function." 4997 // Nonstatic member functions match targets of 4998 // type "pointer-to-member-function." 4999 // Note that according to DR 247, the containing class does not matter. 5000 5001 if (FunctionTemplateDecl *FunctionTemplate 5002 = dyn_cast<FunctionTemplateDecl>(Fn)) { 5003 if (CXXMethodDecl *Method 5004 = dyn_cast<CXXMethodDecl>(FunctionTemplate->getTemplatedDecl())) { 5005 // Skip non-static function templates when converting to pointer, and 5006 // static when converting to member pointer. 5007 if (Method->isStatic() == IsMember) 5008 continue; 5009 } else if (IsMember) 5010 continue; 5011 5012 // C++ [over.over]p2: 5013 // If the name is a function template, template argument deduction is 5014 // done (14.8.2.2), and if the argument deduction succeeds, the 5015 // resulting template argument list is used to generate a single 5016 // function template specialization, which is added to the set of 5017 // overloaded functions considered. 5018 // FIXME: We don't really want to build the specialization here, do we? 5019 FunctionDecl *Specialization = 0; 5020 TemplateDeductionInfo Info(Context, OvlExpr->getNameLoc()); 5021 if (TemplateDeductionResult Result 5022 = DeduceTemplateArguments(FunctionTemplate, ExplicitTemplateArgs, 5023 FunctionType, Specialization, Info)) { 5024 // FIXME: make a note of the failed deduction for diagnostics. 5025 (void)Result; 5026 } else { 5027 // FIXME: If the match isn't exact, shouldn't we just drop this as 5028 // a candidate? Find a testcase before changing the code. 5029 assert(FunctionType 5030 == Context.getCanonicalType(Specialization->getType())); 5031 Matches.push_back(std::make_pair(I.getPair(), 5032 cast<FunctionDecl>(Specialization->getCanonicalDecl()))); 5033 } 5034 5035 continue; 5036 } 5037 5038 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 5039 // Skip non-static functions when converting to pointer, and static 5040 // when converting to member pointer. 5041 if (Method->isStatic() == IsMember) 5042 continue; 5043 5044 // If we have explicit template arguments, skip non-templates. 5045 if (OvlExpr->hasExplicitTemplateArgs()) 5046 continue; 5047 } else if (IsMember) 5048 continue; 5049 5050 if (FunctionDecl *FunDecl = dyn_cast<FunctionDecl>(Fn)) { 5051 QualType ResultTy; 5052 if (Context.hasSameUnqualifiedType(FunctionType, FunDecl->getType()) || 5053 IsNoReturnConversion(Context, FunDecl->getType(), FunctionType, 5054 ResultTy)) { 5055 Matches.push_back(std::make_pair(I.getPair(), 5056 cast<FunctionDecl>(FunDecl->getCanonicalDecl()))); 5057 FoundNonTemplateFunction = true; 5058 } 5059 } 5060 } 5061 5062 // If there were 0 or 1 matches, we're done. 5063 if (Matches.empty()) 5064 return 0; 5065 else if (Matches.size() == 1) { 5066 FunctionDecl *Result = Matches[0].second; 5067 FoundResult = Matches[0].first; 5068 MarkDeclarationReferenced(From->getLocStart(), Result); 5069 if (Complain) 5070 CheckAddressOfMemberAccess(OvlExpr, Matches[0].first); 5071 return Result; 5072 } 5073 5074 // C++ [over.over]p4: 5075 // If more than one function is selected, [...] 5076 if (!FoundNonTemplateFunction) { 5077 // [...] and any given function template specialization F1 is 5078 // eliminated if the set contains a second function template 5079 // specialization whose function template is more specialized 5080 // than the function template of F1 according to the partial 5081 // ordering rules of 14.5.5.2. 5082 5083 // The algorithm specified above is quadratic. We instead use a 5084 // two-pass algorithm (similar to the one used to identify the 5085 // best viable function in an overload set) that identifies the 5086 // best function template (if it exists). 5087 5088 UnresolvedSet<4> MatchesCopy; // TODO: avoid! 5089 for (unsigned I = 0, E = Matches.size(); I != E; ++I) 5090 MatchesCopy.addDecl(Matches[I].second, Matches[I].first.getAccess()); 5091 5092 UnresolvedSetIterator Result = 5093 getMostSpecialized(MatchesCopy.begin(), MatchesCopy.end(), 5094 TPOC_Other, From->getLocStart(), 5095 PDiag(), 5096 PDiag(diag::err_addr_ovl_ambiguous) 5097 << Matches[0].second->getDeclName(), 5098 PDiag(diag::note_ovl_candidate) 5099 << (unsigned) oc_function_template); 5100 assert(Result != MatchesCopy.end() && "no most-specialized template"); 5101 MarkDeclarationReferenced(From->getLocStart(), *Result); 5102 FoundResult = Matches[Result - MatchesCopy.begin()].first; 5103 if (Complain) 5104 CheckUnresolvedAccess(*this, OvlExpr, FoundResult); 5105 return cast<FunctionDecl>(*Result); 5106 } 5107 5108 // [...] any function template specializations in the set are 5109 // eliminated if the set also contains a non-template function, [...] 5110 for (unsigned I = 0, N = Matches.size(); I != N; ) { 5111 if (Matches[I].second->getPrimaryTemplate() == 0) 5112 ++I; 5113 else { 5114 Matches[I] = Matches[--N]; 5115 Matches.set_size(N); 5116 } 5117 } 5118 5119 // [...] After such eliminations, if any, there shall remain exactly one 5120 // selected function. 5121 if (Matches.size() == 1) { 5122 MarkDeclarationReferenced(From->getLocStart(), Matches[0].second); 5123 FoundResult = Matches[0].first; 5124 if (Complain) 5125 CheckUnresolvedAccess(*this, OvlExpr, Matches[0].first); 5126 return cast<FunctionDecl>(Matches[0].second); 5127 } 5128 5129 // FIXME: We should probably return the same thing that BestViableFunction 5130 // returns (even if we issue the diagnostics here). 5131 Diag(From->getLocStart(), diag::err_addr_ovl_ambiguous) 5132 << Matches[0].second->getDeclName(); 5133 for (unsigned I = 0, E = Matches.size(); I != E; ++I) 5134 NoteOverloadCandidate(Matches[I].second); 5135 return 0; 5136} 5137 5138/// \brief Given an expression that refers to an overloaded function, try to 5139/// resolve that overloaded function expression down to a single function. 5140/// 5141/// This routine can only resolve template-ids that refer to a single function 5142/// template, where that template-id refers to a single template whose template 5143/// arguments are either provided by the template-id or have defaults, 5144/// as described in C++0x [temp.arg.explicit]p3. 5145FunctionDecl *Sema::ResolveSingleFunctionTemplateSpecialization(Expr *From) { 5146 // C++ [over.over]p1: 5147 // [...] [Note: any redundant set of parentheses surrounding the 5148 // overloaded function name is ignored (5.1). ] 5149 // C++ [over.over]p1: 5150 // [...] The overloaded function name can be preceded by the & 5151 // operator. 5152 5153 if (From->getType() != Context.OverloadTy) 5154 return 0; 5155 5156 OverloadExpr *OvlExpr = OverloadExpr::find(From).getPointer(); 5157 5158 // If we didn't actually find any template-ids, we're done. 5159 if (!OvlExpr->hasExplicitTemplateArgs()) 5160 return 0; 5161 5162 TemplateArgumentListInfo ExplicitTemplateArgs; 5163 OvlExpr->getExplicitTemplateArgs().copyInto(ExplicitTemplateArgs); 5164 5165 // Look through all of the overloaded functions, searching for one 5166 // whose type matches exactly. 5167 FunctionDecl *Matched = 0; 5168 for (UnresolvedSetIterator I = OvlExpr->decls_begin(), 5169 E = OvlExpr->decls_end(); I != E; ++I) { 5170 // C++0x [temp.arg.explicit]p3: 5171 // [...] In contexts where deduction is done and fails, or in contexts 5172 // where deduction is not done, if a template argument list is 5173 // specified and it, along with any default template arguments, 5174 // identifies a single function template specialization, then the 5175 // template-id is an lvalue for the function template specialization. 5176 FunctionTemplateDecl *FunctionTemplate = cast<FunctionTemplateDecl>(*I); 5177 5178 // C++ [over.over]p2: 5179 // If the name is a function template, template argument deduction is 5180 // done (14.8.2.2), and if the argument deduction succeeds, the 5181 // resulting template argument list is used to generate a single 5182 // function template specialization, which is added to the set of 5183 // overloaded functions considered. 5184 FunctionDecl *Specialization = 0; 5185 TemplateDeductionInfo Info(Context, OvlExpr->getNameLoc()); 5186 if (TemplateDeductionResult Result 5187 = DeduceTemplateArguments(FunctionTemplate, &ExplicitTemplateArgs, 5188 Specialization, Info)) { 5189 // FIXME: make a note of the failed deduction for diagnostics. 5190 (void)Result; 5191 continue; 5192 } 5193 5194 // Multiple matches; we can't resolve to a single declaration. 5195 if (Matched) 5196 return 0; 5197 5198 Matched = Specialization; 5199 } 5200 5201 return Matched; 5202} 5203 5204/// \brief Add a single candidate to the overload set. 5205static void AddOverloadedCallCandidate(Sema &S, 5206 DeclAccessPair FoundDecl, 5207 const TemplateArgumentListInfo *ExplicitTemplateArgs, 5208 Expr **Args, unsigned NumArgs, 5209 OverloadCandidateSet &CandidateSet, 5210 bool PartialOverloading) { 5211 NamedDecl *Callee = FoundDecl.getDecl(); 5212 if (isa<UsingShadowDecl>(Callee)) 5213 Callee = cast<UsingShadowDecl>(Callee)->getTargetDecl(); 5214 5215 if (FunctionDecl *Func = dyn_cast<FunctionDecl>(Callee)) { 5216 assert(!ExplicitTemplateArgs && "Explicit template arguments?"); 5217 S.AddOverloadCandidate(Func, FoundDecl, Args, NumArgs, CandidateSet, 5218 false, false, PartialOverloading); 5219 return; 5220 } 5221 5222 if (FunctionTemplateDecl *FuncTemplate 5223 = dyn_cast<FunctionTemplateDecl>(Callee)) { 5224 S.AddTemplateOverloadCandidate(FuncTemplate, FoundDecl, 5225 ExplicitTemplateArgs, 5226 Args, NumArgs, CandidateSet); 5227 return; 5228 } 5229 5230 assert(false && "unhandled case in overloaded call candidate"); 5231 5232 // do nothing? 5233} 5234 5235/// \brief Add the overload candidates named by callee and/or found by argument 5236/// dependent lookup to the given overload set. 5237void Sema::AddOverloadedCallCandidates(UnresolvedLookupExpr *ULE, 5238 Expr **Args, unsigned NumArgs, 5239 OverloadCandidateSet &CandidateSet, 5240 bool PartialOverloading) { 5241 5242#ifndef NDEBUG 5243 // Verify that ArgumentDependentLookup is consistent with the rules 5244 // in C++0x [basic.lookup.argdep]p3: 5245 // 5246 // Let X be the lookup set produced by unqualified lookup (3.4.1) 5247 // and let Y be the lookup set produced by argument dependent 5248 // lookup (defined as follows). If X contains 5249 // 5250 // -- a declaration of a class member, or 5251 // 5252 // -- a block-scope function declaration that is not a 5253 // using-declaration, or 5254 // 5255 // -- a declaration that is neither a function or a function 5256 // template 5257 // 5258 // then Y is empty. 5259 5260 if (ULE->requiresADL()) { 5261 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(), 5262 E = ULE->decls_end(); I != E; ++I) { 5263 assert(!(*I)->getDeclContext()->isRecord()); 5264 assert(isa<UsingShadowDecl>(*I) || 5265 !(*I)->getDeclContext()->isFunctionOrMethod()); 5266 assert((*I)->getUnderlyingDecl()->isFunctionOrFunctionTemplate()); 5267 } 5268 } 5269#endif 5270 5271 // It would be nice to avoid this copy. 5272 TemplateArgumentListInfo TABuffer; 5273 const TemplateArgumentListInfo *ExplicitTemplateArgs = 0; 5274 if (ULE->hasExplicitTemplateArgs()) { 5275 ULE->copyTemplateArgumentsInto(TABuffer); 5276 ExplicitTemplateArgs = &TABuffer; 5277 } 5278 5279 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(), 5280 E = ULE->decls_end(); I != E; ++I) 5281 AddOverloadedCallCandidate(*this, I.getPair(), ExplicitTemplateArgs, 5282 Args, NumArgs, CandidateSet, 5283 PartialOverloading); 5284 5285 if (ULE->requiresADL()) 5286 AddArgumentDependentLookupCandidates(ULE->getName(), /*Operator*/ false, 5287 Args, NumArgs, 5288 ExplicitTemplateArgs, 5289 CandidateSet, 5290 PartialOverloading); 5291} 5292 5293static Sema::OwningExprResult Destroy(Sema &SemaRef, Expr *Fn, 5294 Expr **Args, unsigned NumArgs) { 5295 Fn->Destroy(SemaRef.Context); 5296 for (unsigned Arg = 0; Arg < NumArgs; ++Arg) 5297 Args[Arg]->Destroy(SemaRef.Context); 5298 return SemaRef.ExprError(); 5299} 5300 5301/// Attempts to recover from a call where no functions were found. 5302/// 5303/// Returns true if new candidates were found. 5304static Sema::OwningExprResult 5305BuildRecoveryCallExpr(Sema &SemaRef, Expr *Fn, 5306 UnresolvedLookupExpr *ULE, 5307 SourceLocation LParenLoc, 5308 Expr **Args, unsigned NumArgs, 5309 SourceLocation *CommaLocs, 5310 SourceLocation RParenLoc) { 5311 5312 CXXScopeSpec SS; 5313 if (ULE->getQualifier()) { 5314 SS.setScopeRep(ULE->getQualifier()); 5315 SS.setRange(ULE->getQualifierRange()); 5316 } 5317 5318 TemplateArgumentListInfo TABuffer; 5319 const TemplateArgumentListInfo *ExplicitTemplateArgs = 0; 5320 if (ULE->hasExplicitTemplateArgs()) { 5321 ULE->copyTemplateArgumentsInto(TABuffer); 5322 ExplicitTemplateArgs = &TABuffer; 5323 } 5324 5325 LookupResult R(SemaRef, ULE->getName(), ULE->getNameLoc(), 5326 Sema::LookupOrdinaryName); 5327 if (SemaRef.DiagnoseEmptyLookup(/*Scope=*/0, SS, R)) 5328 return Destroy(SemaRef, Fn, Args, NumArgs); 5329 5330 assert(!R.empty() && "lookup results empty despite recovery"); 5331 5332 // Build an implicit member call if appropriate. Just drop the 5333 // casts and such from the call, we don't really care. 5334 Sema::OwningExprResult NewFn = SemaRef.ExprError(); 5335 if ((*R.begin())->isCXXClassMember()) 5336 NewFn = SemaRef.BuildPossibleImplicitMemberExpr(SS, R, ExplicitTemplateArgs); 5337 else if (ExplicitTemplateArgs) 5338 NewFn = SemaRef.BuildTemplateIdExpr(SS, R, false, *ExplicitTemplateArgs); 5339 else 5340 NewFn = SemaRef.BuildDeclarationNameExpr(SS, R, false); 5341 5342 if (NewFn.isInvalid()) 5343 return Destroy(SemaRef, Fn, Args, NumArgs); 5344 5345 Fn->Destroy(SemaRef.Context); 5346 5347 // This shouldn't cause an infinite loop because we're giving it 5348 // an expression with non-empty lookup results, which should never 5349 // end up here. 5350 return SemaRef.ActOnCallExpr(/*Scope*/ 0, move(NewFn), LParenLoc, 5351 Sema::MultiExprArg(SemaRef, (void**) Args, NumArgs), 5352 CommaLocs, RParenLoc); 5353} 5354 5355/// ResolveOverloadedCallFn - Given the call expression that calls Fn 5356/// (which eventually refers to the declaration Func) and the call 5357/// arguments Args/NumArgs, attempt to resolve the function call down 5358/// to a specific function. If overload resolution succeeds, returns 5359/// the function declaration produced by overload 5360/// resolution. Otherwise, emits diagnostics, deletes all of the 5361/// arguments and Fn, and returns NULL. 5362Sema::OwningExprResult 5363Sema::BuildOverloadedCallExpr(Expr *Fn, UnresolvedLookupExpr *ULE, 5364 SourceLocation LParenLoc, 5365 Expr **Args, unsigned NumArgs, 5366 SourceLocation *CommaLocs, 5367 SourceLocation RParenLoc) { 5368#ifndef NDEBUG 5369 if (ULE->requiresADL()) { 5370 // To do ADL, we must have found an unqualified name. 5371 assert(!ULE->getQualifier() && "qualified name with ADL"); 5372 5373 // We don't perform ADL for implicit declarations of builtins. 5374 // Verify that this was correctly set up. 5375 FunctionDecl *F; 5376 if (ULE->decls_begin() + 1 == ULE->decls_end() && 5377 (F = dyn_cast<FunctionDecl>(*ULE->decls_begin())) && 5378 F->getBuiltinID() && F->isImplicit()) 5379 assert(0 && "performing ADL for builtin"); 5380 5381 // We don't perform ADL in C. 5382 assert(getLangOptions().CPlusPlus && "ADL enabled in C"); 5383 } 5384#endif 5385 5386 OverloadCandidateSet CandidateSet(Fn->getExprLoc()); 5387 5388 // Add the functions denoted by the callee to the set of candidate 5389 // functions, including those from argument-dependent lookup. 5390 AddOverloadedCallCandidates(ULE, Args, NumArgs, CandidateSet); 5391 5392 // If we found nothing, try to recover. 5393 // AddRecoveryCallCandidates diagnoses the error itself, so we just 5394 // bailout out if it fails. 5395 if (CandidateSet.empty()) 5396 return BuildRecoveryCallExpr(*this, Fn, ULE, LParenLoc, Args, NumArgs, 5397 CommaLocs, RParenLoc); 5398 5399 OverloadCandidateSet::iterator Best; 5400 switch (BestViableFunction(CandidateSet, Fn->getLocStart(), Best)) { 5401 case OR_Success: { 5402 FunctionDecl *FDecl = Best->Function; 5403 CheckUnresolvedLookupAccess(ULE, Best->FoundDecl); 5404 Fn = FixOverloadedFunctionReference(Fn, Best->FoundDecl, FDecl); 5405 return BuildResolvedCallExpr(Fn, FDecl, LParenLoc, Args, NumArgs, RParenLoc); 5406 } 5407 5408 case OR_No_Viable_Function: 5409 Diag(Fn->getSourceRange().getBegin(), 5410 diag::err_ovl_no_viable_function_in_call) 5411 << ULE->getName() << Fn->getSourceRange(); 5412 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 5413 break; 5414 5415 case OR_Ambiguous: 5416 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_ambiguous_call) 5417 << ULE->getName() << Fn->getSourceRange(); 5418 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, NumArgs); 5419 break; 5420 5421 case OR_Deleted: 5422 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_deleted_call) 5423 << Best->Function->isDeleted() 5424 << ULE->getName() 5425 << Fn->getSourceRange(); 5426 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 5427 break; 5428 } 5429 5430 // Overload resolution failed. Destroy all of the subexpressions and 5431 // return NULL. 5432 Fn->Destroy(Context); 5433 for (unsigned Arg = 0; Arg < NumArgs; ++Arg) 5434 Args[Arg]->Destroy(Context); 5435 return ExprError(); 5436} 5437 5438static bool IsOverloaded(const UnresolvedSetImpl &Functions) { 5439 return Functions.size() > 1 || 5440 (Functions.size() == 1 && isa<FunctionTemplateDecl>(*Functions.begin())); 5441} 5442 5443/// \brief Create a unary operation that may resolve to an overloaded 5444/// operator. 5445/// 5446/// \param OpLoc The location of the operator itself (e.g., '*'). 5447/// 5448/// \param OpcIn The UnaryOperator::Opcode that describes this 5449/// operator. 5450/// 5451/// \param Functions The set of non-member functions that will be 5452/// considered by overload resolution. The caller needs to build this 5453/// set based on the context using, e.g., 5454/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 5455/// set should not contain any member functions; those will be added 5456/// by CreateOverloadedUnaryOp(). 5457/// 5458/// \param input The input argument. 5459Sema::OwningExprResult 5460Sema::CreateOverloadedUnaryOp(SourceLocation OpLoc, unsigned OpcIn, 5461 const UnresolvedSetImpl &Fns, 5462 ExprArg input) { 5463 UnaryOperator::Opcode Opc = static_cast<UnaryOperator::Opcode>(OpcIn); 5464 Expr *Input = (Expr *)input.get(); 5465 5466 OverloadedOperatorKind Op = UnaryOperator::getOverloadedOperator(Opc); 5467 assert(Op != OO_None && "Invalid opcode for overloaded unary operator"); 5468 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 5469 5470 Expr *Args[2] = { Input, 0 }; 5471 unsigned NumArgs = 1; 5472 5473 // For post-increment and post-decrement, add the implicit '0' as 5474 // the second argument, so that we know this is a post-increment or 5475 // post-decrement. 5476 if (Opc == UnaryOperator::PostInc || Opc == UnaryOperator::PostDec) { 5477 llvm::APSInt Zero(Context.getTypeSize(Context.IntTy), false); 5478 Args[1] = new (Context) IntegerLiteral(Zero, Context.IntTy, 5479 SourceLocation()); 5480 NumArgs = 2; 5481 } 5482 5483 if (Input->isTypeDependent()) { 5484 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 5485 UnresolvedLookupExpr *Fn 5486 = UnresolvedLookupExpr::Create(Context, /*Dependent*/ true, NamingClass, 5487 0, SourceRange(), OpName, OpLoc, 5488 /*ADL*/ true, IsOverloaded(Fns)); 5489 Fn->addDecls(Fns.begin(), Fns.end()); 5490 5491 input.release(); 5492 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 5493 &Args[0], NumArgs, 5494 Context.DependentTy, 5495 OpLoc)); 5496 } 5497 5498 // Build an empty overload set. 5499 OverloadCandidateSet CandidateSet(OpLoc); 5500 5501 // Add the candidates from the given function set. 5502 AddFunctionCandidates(Fns, &Args[0], NumArgs, CandidateSet, false); 5503 5504 // Add operator candidates that are member functions. 5505 AddMemberOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 5506 5507 // Add candidates from ADL. 5508 AddArgumentDependentLookupCandidates(OpName, /*Operator*/ true, 5509 Args, NumArgs, 5510 /*ExplicitTemplateArgs*/ 0, 5511 CandidateSet); 5512 5513 // Add builtin operator candidates. 5514 AddBuiltinOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 5515 5516 // Perform overload resolution. 5517 OverloadCandidateSet::iterator Best; 5518 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 5519 case OR_Success: { 5520 // We found a built-in operator or an overloaded operator. 5521 FunctionDecl *FnDecl = Best->Function; 5522 5523 if (FnDecl) { 5524 // We matched an overloaded operator. Build a call to that 5525 // operator. 5526 5527 // Convert the arguments. 5528 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 5529 CheckMemberOperatorAccess(OpLoc, Args[0], 0, Best->FoundDecl); 5530 5531 if (PerformObjectArgumentInitialization(Input, /*Qualifier=*/0, 5532 Best->FoundDecl, Method)) 5533 return ExprError(); 5534 } else { 5535 // Convert the arguments. 5536 OwningExprResult InputInit 5537 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 5538 FnDecl->getParamDecl(0)), 5539 SourceLocation(), 5540 move(input)); 5541 if (InputInit.isInvalid()) 5542 return ExprError(); 5543 5544 input = move(InputInit); 5545 Input = (Expr *)input.get(); 5546 } 5547 5548 // Determine the result type 5549 QualType ResultTy = FnDecl->getResultType().getNonReferenceType(); 5550 5551 // Build the actual expression node. 5552 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 5553 SourceLocation()); 5554 UsualUnaryConversions(FnExpr); 5555 5556 input.release(); 5557 Args[0] = Input; 5558 ExprOwningPtr<CallExpr> TheCall(this, 5559 new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 5560 Args, NumArgs, ResultTy, OpLoc)); 5561 5562 if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall.get(), 5563 FnDecl)) 5564 return ExprError(); 5565 5566 return MaybeBindToTemporary(TheCall.release()); 5567 } else { 5568 // We matched a built-in operator. Convert the arguments, then 5569 // break out so that we will build the appropriate built-in 5570 // operator node. 5571 if (PerformImplicitConversion(Input, Best->BuiltinTypes.ParamTypes[0], 5572 Best->Conversions[0], AA_Passing)) 5573 return ExprError(); 5574 5575 break; 5576 } 5577 } 5578 5579 case OR_No_Viable_Function: 5580 // No viable function; fall through to handling this as a 5581 // built-in operator, which will produce an error message for us. 5582 break; 5583 5584 case OR_Ambiguous: 5585 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 5586 << UnaryOperator::getOpcodeStr(Opc) 5587 << Input->getSourceRange(); 5588 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, NumArgs, 5589 UnaryOperator::getOpcodeStr(Opc), OpLoc); 5590 return ExprError(); 5591 5592 case OR_Deleted: 5593 Diag(OpLoc, diag::err_ovl_deleted_oper) 5594 << Best->Function->isDeleted() 5595 << UnaryOperator::getOpcodeStr(Opc) 5596 << Input->getSourceRange(); 5597 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 5598 return ExprError(); 5599 } 5600 5601 // Either we found no viable overloaded operator or we matched a 5602 // built-in operator. In either case, fall through to trying to 5603 // build a built-in operation. 5604 input.release(); 5605 return CreateBuiltinUnaryOp(OpLoc, Opc, Owned(Input)); 5606} 5607 5608/// \brief Create a binary operation that may resolve to an overloaded 5609/// operator. 5610/// 5611/// \param OpLoc The location of the operator itself (e.g., '+'). 5612/// 5613/// \param OpcIn The BinaryOperator::Opcode that describes this 5614/// operator. 5615/// 5616/// \param Functions The set of non-member functions that will be 5617/// considered by overload resolution. The caller needs to build this 5618/// set based on the context using, e.g., 5619/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 5620/// set should not contain any member functions; those will be added 5621/// by CreateOverloadedBinOp(). 5622/// 5623/// \param LHS Left-hand argument. 5624/// \param RHS Right-hand argument. 5625Sema::OwningExprResult 5626Sema::CreateOverloadedBinOp(SourceLocation OpLoc, 5627 unsigned OpcIn, 5628 const UnresolvedSetImpl &Fns, 5629 Expr *LHS, Expr *RHS) { 5630 Expr *Args[2] = { LHS, RHS }; 5631 LHS=RHS=0; //Please use only Args instead of LHS/RHS couple 5632 5633 BinaryOperator::Opcode Opc = static_cast<BinaryOperator::Opcode>(OpcIn); 5634 OverloadedOperatorKind Op = BinaryOperator::getOverloadedOperator(Opc); 5635 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 5636 5637 // If either side is type-dependent, create an appropriate dependent 5638 // expression. 5639 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 5640 if (Fns.empty()) { 5641 // If there are no functions to store, just build a dependent 5642 // BinaryOperator or CompoundAssignment. 5643 if (Opc <= BinaryOperator::Assign || Opc > BinaryOperator::OrAssign) 5644 return Owned(new (Context) BinaryOperator(Args[0], Args[1], Opc, 5645 Context.DependentTy, OpLoc)); 5646 5647 return Owned(new (Context) CompoundAssignOperator(Args[0], Args[1], Opc, 5648 Context.DependentTy, 5649 Context.DependentTy, 5650 Context.DependentTy, 5651 OpLoc)); 5652 } 5653 5654 // FIXME: save results of ADL from here? 5655 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 5656 UnresolvedLookupExpr *Fn 5657 = UnresolvedLookupExpr::Create(Context, /*Dependent*/ true, NamingClass, 5658 0, SourceRange(), OpName, OpLoc, 5659 /*ADL*/ true, IsOverloaded(Fns)); 5660 5661 Fn->addDecls(Fns.begin(), Fns.end()); 5662 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 5663 Args, 2, 5664 Context.DependentTy, 5665 OpLoc)); 5666 } 5667 5668 // If this is the .* operator, which is not overloadable, just 5669 // create a built-in binary operator. 5670 if (Opc == BinaryOperator::PtrMemD) 5671 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 5672 5673 // If this is the assignment operator, we only perform overload resolution 5674 // if the left-hand side is a class or enumeration type. This is actually 5675 // a hack. The standard requires that we do overload resolution between the 5676 // various built-in candidates, but as DR507 points out, this can lead to 5677 // problems. So we do it this way, which pretty much follows what GCC does. 5678 // Note that we go the traditional code path for compound assignment forms. 5679 if (Opc==BinaryOperator::Assign && !Args[0]->getType()->isOverloadableType()) 5680 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 5681 5682 // Build an empty overload set. 5683 OverloadCandidateSet CandidateSet(OpLoc); 5684 5685 // Add the candidates from the given function set. 5686 AddFunctionCandidates(Fns, Args, 2, CandidateSet, false); 5687 5688 // Add operator candidates that are member functions. 5689 AddMemberOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 5690 5691 // Add candidates from ADL. 5692 AddArgumentDependentLookupCandidates(OpName, /*Operator*/ true, 5693 Args, 2, 5694 /*ExplicitTemplateArgs*/ 0, 5695 CandidateSet); 5696 5697 // Add builtin operator candidates. 5698 AddBuiltinOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 5699 5700 // Perform overload resolution. 5701 OverloadCandidateSet::iterator Best; 5702 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 5703 case OR_Success: { 5704 // We found a built-in operator or an overloaded operator. 5705 FunctionDecl *FnDecl = Best->Function; 5706 5707 if (FnDecl) { 5708 // We matched an overloaded operator. Build a call to that 5709 // operator. 5710 5711 // Convert the arguments. 5712 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 5713 // Best->Access is only meaningful for class members. 5714 CheckMemberOperatorAccess(OpLoc, Args[0], Args[1], Best->FoundDecl); 5715 5716 OwningExprResult Arg1 5717 = PerformCopyInitialization( 5718 InitializedEntity::InitializeParameter( 5719 FnDecl->getParamDecl(0)), 5720 SourceLocation(), 5721 Owned(Args[1])); 5722 if (Arg1.isInvalid()) 5723 return ExprError(); 5724 5725 if (PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/0, 5726 Best->FoundDecl, Method)) 5727 return ExprError(); 5728 5729 Args[1] = RHS = Arg1.takeAs<Expr>(); 5730 } else { 5731 // Convert the arguments. 5732 OwningExprResult Arg0 5733 = PerformCopyInitialization( 5734 InitializedEntity::InitializeParameter( 5735 FnDecl->getParamDecl(0)), 5736 SourceLocation(), 5737 Owned(Args[0])); 5738 if (Arg0.isInvalid()) 5739 return ExprError(); 5740 5741 OwningExprResult Arg1 5742 = PerformCopyInitialization( 5743 InitializedEntity::InitializeParameter( 5744 FnDecl->getParamDecl(1)), 5745 SourceLocation(), 5746 Owned(Args[1])); 5747 if (Arg1.isInvalid()) 5748 return ExprError(); 5749 Args[0] = LHS = Arg0.takeAs<Expr>(); 5750 Args[1] = RHS = Arg1.takeAs<Expr>(); 5751 } 5752 5753 // Determine the result type 5754 QualType ResultTy 5755 = FnDecl->getType()->getAs<FunctionType>()->getResultType(); 5756 ResultTy = ResultTy.getNonReferenceType(); 5757 5758 // Build the actual expression node. 5759 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 5760 OpLoc); 5761 UsualUnaryConversions(FnExpr); 5762 5763 ExprOwningPtr<CXXOperatorCallExpr> 5764 TheCall(this, new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 5765 Args, 2, ResultTy, 5766 OpLoc)); 5767 5768 if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall.get(), 5769 FnDecl)) 5770 return ExprError(); 5771 5772 return MaybeBindToTemporary(TheCall.release()); 5773 } else { 5774 // We matched a built-in operator. Convert the arguments, then 5775 // break out so that we will build the appropriate built-in 5776 // operator node. 5777 if (PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 5778 Best->Conversions[0], AA_Passing) || 5779 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 5780 Best->Conversions[1], AA_Passing)) 5781 return ExprError(); 5782 5783 break; 5784 } 5785 } 5786 5787 case OR_No_Viable_Function: { 5788 // C++ [over.match.oper]p9: 5789 // If the operator is the operator , [...] and there are no 5790 // viable functions, then the operator is assumed to be the 5791 // built-in operator and interpreted according to clause 5. 5792 if (Opc == BinaryOperator::Comma) 5793 break; 5794 5795 // For class as left operand for assignment or compound assigment operator 5796 // do not fall through to handling in built-in, but report that no overloaded 5797 // assignment operator found 5798 OwningExprResult Result = ExprError(); 5799 if (Args[0]->getType()->isRecordType() && 5800 Opc >= BinaryOperator::Assign && Opc <= BinaryOperator::OrAssign) { 5801 Diag(OpLoc, diag::err_ovl_no_viable_oper) 5802 << BinaryOperator::getOpcodeStr(Opc) 5803 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 5804 } else { 5805 // No viable function; try to create a built-in operation, which will 5806 // produce an error. Then, show the non-viable candidates. 5807 Result = CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 5808 } 5809 assert(Result.isInvalid() && 5810 "C++ binary operator overloading is missing candidates!"); 5811 if (Result.isInvalid()) 5812 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2, 5813 BinaryOperator::getOpcodeStr(Opc), OpLoc); 5814 return move(Result); 5815 } 5816 5817 case OR_Ambiguous: 5818 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 5819 << BinaryOperator::getOpcodeStr(Opc) 5820 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 5821 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, 2, 5822 BinaryOperator::getOpcodeStr(Opc), OpLoc); 5823 return ExprError(); 5824 5825 case OR_Deleted: 5826 Diag(OpLoc, diag::err_ovl_deleted_oper) 5827 << Best->Function->isDeleted() 5828 << BinaryOperator::getOpcodeStr(Opc) 5829 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 5830 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2); 5831 return ExprError(); 5832 } 5833 5834 // We matched a built-in operator; build it. 5835 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 5836} 5837 5838Action::OwningExprResult 5839Sema::CreateOverloadedArraySubscriptExpr(SourceLocation LLoc, 5840 SourceLocation RLoc, 5841 ExprArg Base, ExprArg Idx) { 5842 Expr *Args[2] = { static_cast<Expr*>(Base.get()), 5843 static_cast<Expr*>(Idx.get()) }; 5844 DeclarationName OpName = 5845 Context.DeclarationNames.getCXXOperatorName(OO_Subscript); 5846 5847 // If either side is type-dependent, create an appropriate dependent 5848 // expression. 5849 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 5850 5851 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 5852 UnresolvedLookupExpr *Fn 5853 = UnresolvedLookupExpr::Create(Context, /*Dependent*/ true, NamingClass, 5854 0, SourceRange(), OpName, LLoc, 5855 /*ADL*/ true, /*Overloaded*/ false); 5856 // Can't add any actual overloads yet 5857 5858 Base.release(); 5859 Idx.release(); 5860 return Owned(new (Context) CXXOperatorCallExpr(Context, OO_Subscript, Fn, 5861 Args, 2, 5862 Context.DependentTy, 5863 RLoc)); 5864 } 5865 5866 // Build an empty overload set. 5867 OverloadCandidateSet CandidateSet(LLoc); 5868 5869 // Subscript can only be overloaded as a member function. 5870 5871 // Add operator candidates that are member functions. 5872 AddMemberOperatorCandidates(OO_Subscript, LLoc, Args, 2, CandidateSet); 5873 5874 // Add builtin operator candidates. 5875 AddBuiltinOperatorCandidates(OO_Subscript, LLoc, Args, 2, CandidateSet); 5876 5877 // Perform overload resolution. 5878 OverloadCandidateSet::iterator Best; 5879 switch (BestViableFunction(CandidateSet, LLoc, Best)) { 5880 case OR_Success: { 5881 // We found a built-in operator or an overloaded operator. 5882 FunctionDecl *FnDecl = Best->Function; 5883 5884 if (FnDecl) { 5885 // We matched an overloaded operator. Build a call to that 5886 // operator. 5887 5888 CheckMemberOperatorAccess(LLoc, Args[0], Args[1], Best->FoundDecl); 5889 5890 // Convert the arguments. 5891 CXXMethodDecl *Method = cast<CXXMethodDecl>(FnDecl); 5892 if (PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/0, 5893 Best->FoundDecl, Method)) 5894 return ExprError(); 5895 5896 // Convert the arguments. 5897 OwningExprResult InputInit 5898 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 5899 FnDecl->getParamDecl(0)), 5900 SourceLocation(), 5901 Owned(Args[1])); 5902 if (InputInit.isInvalid()) 5903 return ExprError(); 5904 5905 Args[1] = InputInit.takeAs<Expr>(); 5906 5907 // Determine the result type 5908 QualType ResultTy 5909 = FnDecl->getType()->getAs<FunctionType>()->getResultType(); 5910 ResultTy = ResultTy.getNonReferenceType(); 5911 5912 // Build the actual expression node. 5913 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 5914 LLoc); 5915 UsualUnaryConversions(FnExpr); 5916 5917 Base.release(); 5918 Idx.release(); 5919 ExprOwningPtr<CXXOperatorCallExpr> 5920 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Subscript, 5921 FnExpr, Args, 2, 5922 ResultTy, RLoc)); 5923 5924 if (CheckCallReturnType(FnDecl->getResultType(), LLoc, TheCall.get(), 5925 FnDecl)) 5926 return ExprError(); 5927 5928 return MaybeBindToTemporary(TheCall.release()); 5929 } else { 5930 // We matched a built-in operator. Convert the arguments, then 5931 // break out so that we will build the appropriate built-in 5932 // operator node. 5933 if (PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 5934 Best->Conversions[0], AA_Passing) || 5935 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 5936 Best->Conversions[1], AA_Passing)) 5937 return ExprError(); 5938 5939 break; 5940 } 5941 } 5942 5943 case OR_No_Viable_Function: { 5944 if (CandidateSet.empty()) 5945 Diag(LLoc, diag::err_ovl_no_oper) 5946 << Args[0]->getType() << /*subscript*/ 0 5947 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 5948 else 5949 Diag(LLoc, diag::err_ovl_no_viable_subscript) 5950 << Args[0]->getType() 5951 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 5952 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2, 5953 "[]", LLoc); 5954 return ExprError(); 5955 } 5956 5957 case OR_Ambiguous: 5958 Diag(LLoc, diag::err_ovl_ambiguous_oper) 5959 << "[]" << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 5960 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, 2, 5961 "[]", LLoc); 5962 return ExprError(); 5963 5964 case OR_Deleted: 5965 Diag(LLoc, diag::err_ovl_deleted_oper) 5966 << Best->Function->isDeleted() << "[]" 5967 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 5968 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2, 5969 "[]", LLoc); 5970 return ExprError(); 5971 } 5972 5973 // We matched a built-in operator; build it. 5974 Base.release(); 5975 Idx.release(); 5976 return CreateBuiltinArraySubscriptExpr(Owned(Args[0]), LLoc, 5977 Owned(Args[1]), RLoc); 5978} 5979 5980/// BuildCallToMemberFunction - Build a call to a member 5981/// function. MemExpr is the expression that refers to the member 5982/// function (and includes the object parameter), Args/NumArgs are the 5983/// arguments to the function call (not including the object 5984/// parameter). The caller needs to validate that the member 5985/// expression refers to a member function or an overloaded member 5986/// function. 5987Sema::OwningExprResult 5988Sema::BuildCallToMemberFunction(Scope *S, Expr *MemExprE, 5989 SourceLocation LParenLoc, Expr **Args, 5990 unsigned NumArgs, SourceLocation *CommaLocs, 5991 SourceLocation RParenLoc) { 5992 // Dig out the member expression. This holds both the object 5993 // argument and the member function we're referring to. 5994 Expr *NakedMemExpr = MemExprE->IgnoreParens(); 5995 5996 MemberExpr *MemExpr; 5997 CXXMethodDecl *Method = 0; 5998 NamedDecl *FoundDecl = 0; 5999 NestedNameSpecifier *Qualifier = 0; 6000 if (isa<MemberExpr>(NakedMemExpr)) { 6001 MemExpr = cast<MemberExpr>(NakedMemExpr); 6002 Method = cast<CXXMethodDecl>(MemExpr->getMemberDecl()); 6003 FoundDecl = MemExpr->getFoundDecl(); 6004 Qualifier = MemExpr->getQualifier(); 6005 } else { 6006 UnresolvedMemberExpr *UnresExpr = cast<UnresolvedMemberExpr>(NakedMemExpr); 6007 Qualifier = UnresExpr->getQualifier(); 6008 6009 QualType ObjectType = UnresExpr->getBaseType(); 6010 6011 // Add overload candidates 6012 OverloadCandidateSet CandidateSet(UnresExpr->getMemberLoc()); 6013 6014 // FIXME: avoid copy. 6015 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 6016 if (UnresExpr->hasExplicitTemplateArgs()) { 6017 UnresExpr->copyTemplateArgumentsInto(TemplateArgsBuffer); 6018 TemplateArgs = &TemplateArgsBuffer; 6019 } 6020 6021 for (UnresolvedMemberExpr::decls_iterator I = UnresExpr->decls_begin(), 6022 E = UnresExpr->decls_end(); I != E; ++I) { 6023 6024 NamedDecl *Func = *I; 6025 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(Func->getDeclContext()); 6026 if (isa<UsingShadowDecl>(Func)) 6027 Func = cast<UsingShadowDecl>(Func)->getTargetDecl(); 6028 6029 if ((Method = dyn_cast<CXXMethodDecl>(Func))) { 6030 // If explicit template arguments were provided, we can't call a 6031 // non-template member function. 6032 if (TemplateArgs) 6033 continue; 6034 6035 AddMethodCandidate(Method, I.getPair(), ActingDC, ObjectType, 6036 Args, NumArgs, 6037 CandidateSet, /*SuppressUserConversions=*/false); 6038 } else { 6039 AddMethodTemplateCandidate(cast<FunctionTemplateDecl>(Func), 6040 I.getPair(), ActingDC, TemplateArgs, 6041 ObjectType, Args, NumArgs, 6042 CandidateSet, 6043 /*SuppressUsedConversions=*/false); 6044 } 6045 } 6046 6047 DeclarationName DeclName = UnresExpr->getMemberName(); 6048 6049 OverloadCandidateSet::iterator Best; 6050 switch (BestViableFunction(CandidateSet, UnresExpr->getLocStart(), Best)) { 6051 case OR_Success: 6052 Method = cast<CXXMethodDecl>(Best->Function); 6053 FoundDecl = Best->FoundDecl; 6054 CheckUnresolvedMemberAccess(UnresExpr, Best->FoundDecl); 6055 break; 6056 6057 case OR_No_Viable_Function: 6058 Diag(UnresExpr->getMemberLoc(), 6059 diag::err_ovl_no_viable_member_function_in_call) 6060 << DeclName << MemExprE->getSourceRange(); 6061 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6062 // FIXME: Leaking incoming expressions! 6063 return ExprError(); 6064 6065 case OR_Ambiguous: 6066 Diag(UnresExpr->getMemberLoc(), diag::err_ovl_ambiguous_member_call) 6067 << DeclName << MemExprE->getSourceRange(); 6068 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6069 // FIXME: Leaking incoming expressions! 6070 return ExprError(); 6071 6072 case OR_Deleted: 6073 Diag(UnresExpr->getMemberLoc(), diag::err_ovl_deleted_member_call) 6074 << Best->Function->isDeleted() 6075 << DeclName << MemExprE->getSourceRange(); 6076 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6077 // FIXME: Leaking incoming expressions! 6078 return ExprError(); 6079 } 6080 6081 MemExprE = FixOverloadedFunctionReference(MemExprE, FoundDecl, Method); 6082 6083 // If overload resolution picked a static member, build a 6084 // non-member call based on that function. 6085 if (Method->isStatic()) { 6086 return BuildResolvedCallExpr(MemExprE, Method, LParenLoc, 6087 Args, NumArgs, RParenLoc); 6088 } 6089 6090 MemExpr = cast<MemberExpr>(MemExprE->IgnoreParens()); 6091 } 6092 6093 assert(Method && "Member call to something that isn't a method?"); 6094 ExprOwningPtr<CXXMemberCallExpr> 6095 TheCall(this, new (Context) CXXMemberCallExpr(Context, MemExprE, Args, 6096 NumArgs, 6097 Method->getResultType().getNonReferenceType(), 6098 RParenLoc)); 6099 6100 // Check for a valid return type. 6101 if (CheckCallReturnType(Method->getResultType(), MemExpr->getMemberLoc(), 6102 TheCall.get(), Method)) 6103 return ExprError(); 6104 6105 // Convert the object argument (for a non-static member function call). 6106 // We only need to do this if there was actually an overload; otherwise 6107 // it was done at lookup. 6108 Expr *ObjectArg = MemExpr->getBase(); 6109 if (!Method->isStatic() && 6110 PerformObjectArgumentInitialization(ObjectArg, Qualifier, 6111 FoundDecl, Method)) 6112 return ExprError(); 6113 MemExpr->setBase(ObjectArg); 6114 6115 // Convert the rest of the arguments 6116 const FunctionProtoType *Proto = cast<FunctionProtoType>(Method->getType()); 6117 if (ConvertArgumentsForCall(&*TheCall, MemExpr, Method, Proto, Args, NumArgs, 6118 RParenLoc)) 6119 return ExprError(); 6120 6121 if (CheckFunctionCall(Method, TheCall.get())) 6122 return ExprError(); 6123 6124 return MaybeBindToTemporary(TheCall.release()); 6125} 6126 6127/// BuildCallToObjectOfClassType - Build a call to an object of class 6128/// type (C++ [over.call.object]), which can end up invoking an 6129/// overloaded function call operator (@c operator()) or performing a 6130/// user-defined conversion on the object argument. 6131Sema::ExprResult 6132Sema::BuildCallToObjectOfClassType(Scope *S, Expr *Object, 6133 SourceLocation LParenLoc, 6134 Expr **Args, unsigned NumArgs, 6135 SourceLocation *CommaLocs, 6136 SourceLocation RParenLoc) { 6137 assert(Object->getType()->isRecordType() && "Requires object type argument"); 6138 const RecordType *Record = Object->getType()->getAs<RecordType>(); 6139 6140 // C++ [over.call.object]p1: 6141 // If the primary-expression E in the function call syntax 6142 // evaluates to a class object of type "cv T", then the set of 6143 // candidate functions includes at least the function call 6144 // operators of T. The function call operators of T are obtained by 6145 // ordinary lookup of the name operator() in the context of 6146 // (E).operator(). 6147 OverloadCandidateSet CandidateSet(LParenLoc); 6148 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Call); 6149 6150 if (RequireCompleteType(LParenLoc, Object->getType(), 6151 PDiag(diag::err_incomplete_object_call) 6152 << Object->getSourceRange())) 6153 return true; 6154 6155 LookupResult R(*this, OpName, LParenLoc, LookupOrdinaryName); 6156 LookupQualifiedName(R, Record->getDecl()); 6157 R.suppressDiagnostics(); 6158 6159 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 6160 Oper != OperEnd; ++Oper) { 6161 AddMethodCandidate(Oper.getPair(), Object->getType(), 6162 Args, NumArgs, CandidateSet, 6163 /*SuppressUserConversions=*/ false); 6164 } 6165 6166 // C++ [over.call.object]p2: 6167 // In addition, for each conversion function declared in T of the 6168 // form 6169 // 6170 // operator conversion-type-id () cv-qualifier; 6171 // 6172 // where cv-qualifier is the same cv-qualification as, or a 6173 // greater cv-qualification than, cv, and where conversion-type-id 6174 // denotes the type "pointer to function of (P1,...,Pn) returning 6175 // R", or the type "reference to pointer to function of 6176 // (P1,...,Pn) returning R", or the type "reference to function 6177 // of (P1,...,Pn) returning R", a surrogate call function [...] 6178 // is also considered as a candidate function. Similarly, 6179 // surrogate call functions are added to the set of candidate 6180 // functions for each conversion function declared in an 6181 // accessible base class provided the function is not hidden 6182 // within T by another intervening declaration. 6183 const UnresolvedSetImpl *Conversions 6184 = cast<CXXRecordDecl>(Record->getDecl())->getVisibleConversionFunctions(); 6185 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 6186 E = Conversions->end(); I != E; ++I) { 6187 NamedDecl *D = *I; 6188 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext()); 6189 if (isa<UsingShadowDecl>(D)) 6190 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 6191 6192 // Skip over templated conversion functions; they aren't 6193 // surrogates. 6194 if (isa<FunctionTemplateDecl>(D)) 6195 continue; 6196 6197 CXXConversionDecl *Conv = cast<CXXConversionDecl>(D); 6198 6199 // Strip the reference type (if any) and then the pointer type (if 6200 // any) to get down to what might be a function type. 6201 QualType ConvType = Conv->getConversionType().getNonReferenceType(); 6202 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 6203 ConvType = ConvPtrType->getPointeeType(); 6204 6205 if (const FunctionProtoType *Proto = ConvType->getAs<FunctionProtoType>()) 6206 AddSurrogateCandidate(Conv, I.getPair(), ActingContext, Proto, 6207 Object->getType(), Args, NumArgs, 6208 CandidateSet); 6209 } 6210 6211 // Perform overload resolution. 6212 OverloadCandidateSet::iterator Best; 6213 switch (BestViableFunction(CandidateSet, Object->getLocStart(), Best)) { 6214 case OR_Success: 6215 // Overload resolution succeeded; we'll build the appropriate call 6216 // below. 6217 break; 6218 6219 case OR_No_Viable_Function: 6220 if (CandidateSet.empty()) 6221 Diag(Object->getSourceRange().getBegin(), diag::err_ovl_no_oper) 6222 << Object->getType() << /*call*/ 1 6223 << Object->getSourceRange(); 6224 else 6225 Diag(Object->getSourceRange().getBegin(), 6226 diag::err_ovl_no_viable_object_call) 6227 << Object->getType() << Object->getSourceRange(); 6228 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6229 break; 6230 6231 case OR_Ambiguous: 6232 Diag(Object->getSourceRange().getBegin(), 6233 diag::err_ovl_ambiguous_object_call) 6234 << Object->getType() << Object->getSourceRange(); 6235 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, NumArgs); 6236 break; 6237 6238 case OR_Deleted: 6239 Diag(Object->getSourceRange().getBegin(), 6240 diag::err_ovl_deleted_object_call) 6241 << Best->Function->isDeleted() 6242 << Object->getType() << Object->getSourceRange(); 6243 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6244 break; 6245 } 6246 6247 if (Best == CandidateSet.end()) { 6248 // We had an error; delete all of the subexpressions and return 6249 // the error. 6250 Object->Destroy(Context); 6251 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 6252 Args[ArgIdx]->Destroy(Context); 6253 return true; 6254 } 6255 6256 if (Best->Function == 0) { 6257 // Since there is no function declaration, this is one of the 6258 // surrogate candidates. Dig out the conversion function. 6259 CXXConversionDecl *Conv 6260 = cast<CXXConversionDecl>( 6261 Best->Conversions[0].UserDefined.ConversionFunction); 6262 6263 CheckMemberOperatorAccess(LParenLoc, Object, 0, Best->FoundDecl); 6264 6265 // We selected one of the surrogate functions that converts the 6266 // object parameter to a function pointer. Perform the conversion 6267 // on the object argument, then let ActOnCallExpr finish the job. 6268 6269 // Create an implicit member expr to refer to the conversion operator. 6270 // and then call it. 6271 CXXMemberCallExpr *CE = BuildCXXMemberCallExpr(Object, Best->FoundDecl, 6272 Conv); 6273 6274 return ActOnCallExpr(S, ExprArg(*this, CE), LParenLoc, 6275 MultiExprArg(*this, (ExprTy**)Args, NumArgs), 6276 CommaLocs, RParenLoc).release(); 6277 } 6278 6279 CheckMemberOperatorAccess(LParenLoc, Object, 0, Best->FoundDecl); 6280 6281 // We found an overloaded operator(). Build a CXXOperatorCallExpr 6282 // that calls this method, using Object for the implicit object 6283 // parameter and passing along the remaining arguments. 6284 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 6285 const FunctionProtoType *Proto = Method->getType()->getAs<FunctionProtoType>(); 6286 6287 unsigned NumArgsInProto = Proto->getNumArgs(); 6288 unsigned NumArgsToCheck = NumArgs; 6289 6290 // Build the full argument list for the method call (the 6291 // implicit object parameter is placed at the beginning of the 6292 // list). 6293 Expr **MethodArgs; 6294 if (NumArgs < NumArgsInProto) { 6295 NumArgsToCheck = NumArgsInProto; 6296 MethodArgs = new Expr*[NumArgsInProto + 1]; 6297 } else { 6298 MethodArgs = new Expr*[NumArgs + 1]; 6299 } 6300 MethodArgs[0] = Object; 6301 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 6302 MethodArgs[ArgIdx + 1] = Args[ArgIdx]; 6303 6304 Expr *NewFn = new (Context) DeclRefExpr(Method, Method->getType(), 6305 SourceLocation()); 6306 UsualUnaryConversions(NewFn); 6307 6308 // Once we've built TheCall, all of the expressions are properly 6309 // owned. 6310 QualType ResultTy = Method->getResultType().getNonReferenceType(); 6311 ExprOwningPtr<CXXOperatorCallExpr> 6312 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Call, NewFn, 6313 MethodArgs, NumArgs + 1, 6314 ResultTy, RParenLoc)); 6315 delete [] MethodArgs; 6316 6317 if (CheckCallReturnType(Method->getResultType(), LParenLoc, TheCall.get(), 6318 Method)) 6319 return true; 6320 6321 // We may have default arguments. If so, we need to allocate more 6322 // slots in the call for them. 6323 if (NumArgs < NumArgsInProto) 6324 TheCall->setNumArgs(Context, NumArgsInProto + 1); 6325 else if (NumArgs > NumArgsInProto) 6326 NumArgsToCheck = NumArgsInProto; 6327 6328 bool IsError = false; 6329 6330 // Initialize the implicit object parameter. 6331 IsError |= PerformObjectArgumentInitialization(Object, /*Qualifier=*/0, 6332 Best->FoundDecl, Method); 6333 TheCall->setArg(0, Object); 6334 6335 6336 // Check the argument types. 6337 for (unsigned i = 0; i != NumArgsToCheck; i++) { 6338 Expr *Arg; 6339 if (i < NumArgs) { 6340 Arg = Args[i]; 6341 6342 // Pass the argument. 6343 6344 OwningExprResult InputInit 6345 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 6346 Method->getParamDecl(i)), 6347 SourceLocation(), Owned(Arg)); 6348 6349 IsError |= InputInit.isInvalid(); 6350 Arg = InputInit.takeAs<Expr>(); 6351 } else { 6352 OwningExprResult DefArg 6353 = BuildCXXDefaultArgExpr(LParenLoc, Method, Method->getParamDecl(i)); 6354 if (DefArg.isInvalid()) { 6355 IsError = true; 6356 break; 6357 } 6358 6359 Arg = DefArg.takeAs<Expr>(); 6360 } 6361 6362 TheCall->setArg(i + 1, Arg); 6363 } 6364 6365 // If this is a variadic call, handle args passed through "...". 6366 if (Proto->isVariadic()) { 6367 // Promote the arguments (C99 6.5.2.2p7). 6368 for (unsigned i = NumArgsInProto; i != NumArgs; i++) { 6369 Expr *Arg = Args[i]; 6370 IsError |= DefaultVariadicArgumentPromotion(Arg, VariadicMethod); 6371 TheCall->setArg(i + 1, Arg); 6372 } 6373 } 6374 6375 if (IsError) return true; 6376 6377 if (CheckFunctionCall(Method, TheCall.get())) 6378 return true; 6379 6380 return MaybeBindToTemporary(TheCall.release()).release(); 6381} 6382 6383/// BuildOverloadedArrowExpr - Build a call to an overloaded @c operator-> 6384/// (if one exists), where @c Base is an expression of class type and 6385/// @c Member is the name of the member we're trying to find. 6386Sema::OwningExprResult 6387Sema::BuildOverloadedArrowExpr(Scope *S, ExprArg BaseIn, SourceLocation OpLoc) { 6388 Expr *Base = static_cast<Expr *>(BaseIn.get()); 6389 assert(Base->getType()->isRecordType() && "left-hand side must have class type"); 6390 6391 SourceLocation Loc = Base->getExprLoc(); 6392 6393 // C++ [over.ref]p1: 6394 // 6395 // [...] An expression x->m is interpreted as (x.operator->())->m 6396 // for a class object x of type T if T::operator->() exists and if 6397 // the operator is selected as the best match function by the 6398 // overload resolution mechanism (13.3). 6399 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Arrow); 6400 OverloadCandidateSet CandidateSet(Loc); 6401 const RecordType *BaseRecord = Base->getType()->getAs<RecordType>(); 6402 6403 if (RequireCompleteType(Loc, Base->getType(), 6404 PDiag(diag::err_typecheck_incomplete_tag) 6405 << Base->getSourceRange())) 6406 return ExprError(); 6407 6408 LookupResult R(*this, OpName, OpLoc, LookupOrdinaryName); 6409 LookupQualifiedName(R, BaseRecord->getDecl()); 6410 R.suppressDiagnostics(); 6411 6412 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 6413 Oper != OperEnd; ++Oper) { 6414 AddMethodCandidate(Oper.getPair(), Base->getType(), 0, 0, CandidateSet, 6415 /*SuppressUserConversions=*/false); 6416 } 6417 6418 // Perform overload resolution. 6419 OverloadCandidateSet::iterator Best; 6420 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 6421 case OR_Success: 6422 // Overload resolution succeeded; we'll build the call below. 6423 break; 6424 6425 case OR_No_Viable_Function: 6426 if (CandidateSet.empty()) 6427 Diag(OpLoc, diag::err_typecheck_member_reference_arrow) 6428 << Base->getType() << Base->getSourceRange(); 6429 else 6430 Diag(OpLoc, diag::err_ovl_no_viable_oper) 6431 << "operator->" << Base->getSourceRange(); 6432 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, &Base, 1); 6433 return ExprError(); 6434 6435 case OR_Ambiguous: 6436 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 6437 << "->" << Base->getSourceRange(); 6438 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, &Base, 1); 6439 return ExprError(); 6440 6441 case OR_Deleted: 6442 Diag(OpLoc, diag::err_ovl_deleted_oper) 6443 << Best->Function->isDeleted() 6444 << "->" << Base->getSourceRange(); 6445 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, &Base, 1); 6446 return ExprError(); 6447 } 6448 6449 CheckMemberOperatorAccess(OpLoc, Base, 0, Best->FoundDecl); 6450 6451 // Convert the object parameter. 6452 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 6453 if (PerformObjectArgumentInitialization(Base, /*Qualifier=*/0, 6454 Best->FoundDecl, Method)) 6455 return ExprError(); 6456 6457 // No concerns about early exits now. 6458 BaseIn.release(); 6459 6460 // Build the operator call. 6461 Expr *FnExpr = new (Context) DeclRefExpr(Method, Method->getType(), 6462 SourceLocation()); 6463 UsualUnaryConversions(FnExpr); 6464 6465 QualType ResultTy = Method->getResultType().getNonReferenceType(); 6466 ExprOwningPtr<CXXOperatorCallExpr> 6467 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Arrow, FnExpr, 6468 &Base, 1, ResultTy, OpLoc)); 6469 6470 if (CheckCallReturnType(Method->getResultType(), OpLoc, TheCall.get(), 6471 Method)) 6472 return ExprError(); 6473 return move(TheCall); 6474} 6475 6476/// FixOverloadedFunctionReference - E is an expression that refers to 6477/// a C++ overloaded function (possibly with some parentheses and 6478/// perhaps a '&' around it). We have resolved the overloaded function 6479/// to the function declaration Fn, so patch up the expression E to 6480/// refer (possibly indirectly) to Fn. Returns the new expr. 6481Expr *Sema::FixOverloadedFunctionReference(Expr *E, NamedDecl *Found, 6482 FunctionDecl *Fn) { 6483 if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) { 6484 Expr *SubExpr = FixOverloadedFunctionReference(PE->getSubExpr(), 6485 Found, Fn); 6486 if (SubExpr == PE->getSubExpr()) 6487 return PE->Retain(); 6488 6489 return new (Context) ParenExpr(PE->getLParen(), PE->getRParen(), SubExpr); 6490 } 6491 6492 if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) { 6493 Expr *SubExpr = FixOverloadedFunctionReference(ICE->getSubExpr(), 6494 Found, Fn); 6495 assert(Context.hasSameType(ICE->getSubExpr()->getType(), 6496 SubExpr->getType()) && 6497 "Implicit cast type cannot be determined from overload"); 6498 if (SubExpr == ICE->getSubExpr()) 6499 return ICE->Retain(); 6500 6501 return new (Context) ImplicitCastExpr(ICE->getType(), 6502 ICE->getCastKind(), 6503 SubExpr, 6504 ICE->isLvalueCast()); 6505 } 6506 6507 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(E)) { 6508 assert(UnOp->getOpcode() == UnaryOperator::AddrOf && 6509 "Can only take the address of an overloaded function"); 6510 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 6511 if (Method->isStatic()) { 6512 // Do nothing: static member functions aren't any different 6513 // from non-member functions. 6514 } else { 6515 // Fix the sub expression, which really has to be an 6516 // UnresolvedLookupExpr holding an overloaded member function 6517 // or template. 6518 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(), 6519 Found, Fn); 6520 if (SubExpr == UnOp->getSubExpr()) 6521 return UnOp->Retain(); 6522 6523 assert(isa<DeclRefExpr>(SubExpr) 6524 && "fixed to something other than a decl ref"); 6525 assert(cast<DeclRefExpr>(SubExpr)->getQualifier() 6526 && "fixed to a member ref with no nested name qualifier"); 6527 6528 // We have taken the address of a pointer to member 6529 // function. Perform the computation here so that we get the 6530 // appropriate pointer to member type. 6531 QualType ClassType 6532 = Context.getTypeDeclType(cast<RecordDecl>(Method->getDeclContext())); 6533 QualType MemPtrType 6534 = Context.getMemberPointerType(Fn->getType(), ClassType.getTypePtr()); 6535 6536 return new (Context) UnaryOperator(SubExpr, UnaryOperator::AddrOf, 6537 MemPtrType, UnOp->getOperatorLoc()); 6538 } 6539 } 6540 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(), 6541 Found, Fn); 6542 if (SubExpr == UnOp->getSubExpr()) 6543 return UnOp->Retain(); 6544 6545 return new (Context) UnaryOperator(SubExpr, UnaryOperator::AddrOf, 6546 Context.getPointerType(SubExpr->getType()), 6547 UnOp->getOperatorLoc()); 6548 } 6549 6550 if (UnresolvedLookupExpr *ULE = dyn_cast<UnresolvedLookupExpr>(E)) { 6551 // FIXME: avoid copy. 6552 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 6553 if (ULE->hasExplicitTemplateArgs()) { 6554 ULE->copyTemplateArgumentsInto(TemplateArgsBuffer); 6555 TemplateArgs = &TemplateArgsBuffer; 6556 } 6557 6558 return DeclRefExpr::Create(Context, 6559 ULE->getQualifier(), 6560 ULE->getQualifierRange(), 6561 Fn, 6562 ULE->getNameLoc(), 6563 Fn->getType(), 6564 TemplateArgs); 6565 } 6566 6567 if (UnresolvedMemberExpr *MemExpr = dyn_cast<UnresolvedMemberExpr>(E)) { 6568 // FIXME: avoid copy. 6569 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 6570 if (MemExpr->hasExplicitTemplateArgs()) { 6571 MemExpr->copyTemplateArgumentsInto(TemplateArgsBuffer); 6572 TemplateArgs = &TemplateArgsBuffer; 6573 } 6574 6575 Expr *Base; 6576 6577 // If we're filling in 6578 if (MemExpr->isImplicitAccess()) { 6579 if (cast<CXXMethodDecl>(Fn)->isStatic()) { 6580 return DeclRefExpr::Create(Context, 6581 MemExpr->getQualifier(), 6582 MemExpr->getQualifierRange(), 6583 Fn, 6584 MemExpr->getMemberLoc(), 6585 Fn->getType(), 6586 TemplateArgs); 6587 } else { 6588 SourceLocation Loc = MemExpr->getMemberLoc(); 6589 if (MemExpr->getQualifier()) 6590 Loc = MemExpr->getQualifierRange().getBegin(); 6591 Base = new (Context) CXXThisExpr(Loc, 6592 MemExpr->getBaseType(), 6593 /*isImplicit=*/true); 6594 } 6595 } else 6596 Base = MemExpr->getBase()->Retain(); 6597 6598 return MemberExpr::Create(Context, Base, 6599 MemExpr->isArrow(), 6600 MemExpr->getQualifier(), 6601 MemExpr->getQualifierRange(), 6602 Fn, 6603 Found, 6604 MemExpr->getMemberLoc(), 6605 TemplateArgs, 6606 Fn->getType()); 6607 } 6608 6609 assert(false && "Invalid reference to overloaded function"); 6610 return E->Retain(); 6611} 6612 6613Sema::OwningExprResult Sema::FixOverloadedFunctionReference(OwningExprResult E, 6614 NamedDecl *Found, 6615 FunctionDecl *Fn) { 6616 return Owned(FixOverloadedFunctionReference((Expr *)E.get(), Found, Fn)); 6617} 6618 6619} // end namespace clang 6620