SemaOverload.cpp revision bb6fb465c718f28b8c1bdddb9c22d7d733a741a7
1//===--- SemaOverload.cpp - C++ Overloading ---------------------*- C++ -*-===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This file provides Sema routines for C++ overloading. 11// 12//===----------------------------------------------------------------------===// 13 14#include "Sema.h" 15#include "Lookup.h" 16#include "SemaInit.h" 17#include "clang/Basic/Diagnostic.h" 18#include "clang/Lex/Preprocessor.h" 19#include "clang/AST/ASTContext.h" 20#include "clang/AST/CXXInheritance.h" 21#include "clang/AST/Expr.h" 22#include "clang/AST/ExprCXX.h" 23#include "clang/AST/TypeOrdering.h" 24#include "clang/Basic/PartialDiagnostic.h" 25#include "llvm/ADT/SmallPtrSet.h" 26#include "llvm/ADT/STLExtras.h" 27#include <algorithm> 28 29namespace clang { 30 31/// GetConversionCategory - Retrieve the implicit conversion 32/// category corresponding to the given implicit conversion kind. 33ImplicitConversionCategory 34GetConversionCategory(ImplicitConversionKind Kind) { 35 static const ImplicitConversionCategory 36 Category[(int)ICK_Num_Conversion_Kinds] = { 37 ICC_Identity, 38 ICC_Lvalue_Transformation, 39 ICC_Lvalue_Transformation, 40 ICC_Lvalue_Transformation, 41 ICC_Identity, 42 ICC_Qualification_Adjustment, 43 ICC_Promotion, 44 ICC_Promotion, 45 ICC_Promotion, 46 ICC_Conversion, 47 ICC_Conversion, 48 ICC_Conversion, 49 ICC_Conversion, 50 ICC_Conversion, 51 ICC_Conversion, 52 ICC_Conversion, 53 ICC_Conversion, 54 ICC_Conversion, 55 ICC_Conversion 56 }; 57 return Category[(int)Kind]; 58} 59 60/// GetConversionRank - Retrieve the implicit conversion rank 61/// corresponding to the given implicit conversion kind. 62ImplicitConversionRank GetConversionRank(ImplicitConversionKind Kind) { 63 static const ImplicitConversionRank 64 Rank[(int)ICK_Num_Conversion_Kinds] = { 65 ICR_Exact_Match, 66 ICR_Exact_Match, 67 ICR_Exact_Match, 68 ICR_Exact_Match, 69 ICR_Exact_Match, 70 ICR_Exact_Match, 71 ICR_Promotion, 72 ICR_Promotion, 73 ICR_Promotion, 74 ICR_Conversion, 75 ICR_Conversion, 76 ICR_Conversion, 77 ICR_Conversion, 78 ICR_Conversion, 79 ICR_Conversion, 80 ICR_Conversion, 81 ICR_Conversion, 82 ICR_Conversion, 83 ICR_Complex_Real_Conversion 84 }; 85 return Rank[(int)Kind]; 86} 87 88/// GetImplicitConversionName - Return the name of this kind of 89/// implicit conversion. 90const char* GetImplicitConversionName(ImplicitConversionKind Kind) { 91 static const char* const Name[(int)ICK_Num_Conversion_Kinds] = { 92 "No conversion", 93 "Lvalue-to-rvalue", 94 "Array-to-pointer", 95 "Function-to-pointer", 96 "Noreturn adjustment", 97 "Qualification", 98 "Integral promotion", 99 "Floating point promotion", 100 "Complex promotion", 101 "Integral conversion", 102 "Floating conversion", 103 "Complex conversion", 104 "Floating-integral conversion", 105 "Complex-real conversion", 106 "Pointer conversion", 107 "Pointer-to-member conversion", 108 "Boolean conversion", 109 "Compatible-types conversion", 110 "Derived-to-base conversion" 111 }; 112 return Name[Kind]; 113} 114 115/// StandardConversionSequence - Set the standard conversion 116/// sequence to the identity conversion. 117void StandardConversionSequence::setAsIdentityConversion() { 118 First = ICK_Identity; 119 Second = ICK_Identity; 120 Third = ICK_Identity; 121 DeprecatedStringLiteralToCharPtr = false; 122 ReferenceBinding = false; 123 DirectBinding = false; 124 RRefBinding = false; 125 CopyConstructor = 0; 126} 127 128/// getRank - Retrieve the rank of this standard conversion sequence 129/// (C++ 13.3.3.1.1p3). The rank is the largest rank of each of the 130/// implicit conversions. 131ImplicitConversionRank StandardConversionSequence::getRank() const { 132 ImplicitConversionRank Rank = ICR_Exact_Match; 133 if (GetConversionRank(First) > Rank) 134 Rank = GetConversionRank(First); 135 if (GetConversionRank(Second) > Rank) 136 Rank = GetConversionRank(Second); 137 if (GetConversionRank(Third) > Rank) 138 Rank = GetConversionRank(Third); 139 return Rank; 140} 141 142/// isPointerConversionToBool - Determines whether this conversion is 143/// a conversion of a pointer or pointer-to-member to bool. This is 144/// used as part of the ranking of standard conversion sequences 145/// (C++ 13.3.3.2p4). 146bool StandardConversionSequence::isPointerConversionToBool() const { 147 // Note that FromType has not necessarily been transformed by the 148 // array-to-pointer or function-to-pointer implicit conversions, so 149 // check for their presence as well as checking whether FromType is 150 // a pointer. 151 if (getToType(1)->isBooleanType() && 152 (getFromType()->isPointerType() || getFromType()->isBlockPointerType() || 153 First == ICK_Array_To_Pointer || First == ICK_Function_To_Pointer)) 154 return true; 155 156 return false; 157} 158 159/// isPointerConversionToVoidPointer - Determines whether this 160/// conversion is a conversion of a pointer to a void pointer. This is 161/// used as part of the ranking of standard conversion sequences (C++ 162/// 13.3.3.2p4). 163bool 164StandardConversionSequence:: 165isPointerConversionToVoidPointer(ASTContext& Context) const { 166 QualType FromType = getFromType(); 167 QualType ToType = getToType(1); 168 169 // Note that FromType has not necessarily been transformed by the 170 // array-to-pointer implicit conversion, so check for its presence 171 // and redo the conversion to get a pointer. 172 if (First == ICK_Array_To_Pointer) 173 FromType = Context.getArrayDecayedType(FromType); 174 175 if (Second == ICK_Pointer_Conversion && FromType->isPointerType()) 176 if (const PointerType* ToPtrType = ToType->getAs<PointerType>()) 177 return ToPtrType->getPointeeType()->isVoidType(); 178 179 return false; 180} 181 182/// DebugPrint - Print this standard conversion sequence to standard 183/// error. Useful for debugging overloading issues. 184void StandardConversionSequence::DebugPrint() const { 185 llvm::raw_ostream &OS = llvm::errs(); 186 bool PrintedSomething = false; 187 if (First != ICK_Identity) { 188 OS << GetImplicitConversionName(First); 189 PrintedSomething = true; 190 } 191 192 if (Second != ICK_Identity) { 193 if (PrintedSomething) { 194 OS << " -> "; 195 } 196 OS << GetImplicitConversionName(Second); 197 198 if (CopyConstructor) { 199 OS << " (by copy constructor)"; 200 } else if (DirectBinding) { 201 OS << " (direct reference binding)"; 202 } else if (ReferenceBinding) { 203 OS << " (reference binding)"; 204 } 205 PrintedSomething = true; 206 } 207 208 if (Third != ICK_Identity) { 209 if (PrintedSomething) { 210 OS << " -> "; 211 } 212 OS << GetImplicitConversionName(Third); 213 PrintedSomething = true; 214 } 215 216 if (!PrintedSomething) { 217 OS << "No conversions required"; 218 } 219} 220 221/// DebugPrint - Print this user-defined conversion sequence to standard 222/// error. Useful for debugging overloading issues. 223void UserDefinedConversionSequence::DebugPrint() const { 224 llvm::raw_ostream &OS = llvm::errs(); 225 if (Before.First || Before.Second || Before.Third) { 226 Before.DebugPrint(); 227 OS << " -> "; 228 } 229 OS << "'" << ConversionFunction->getNameAsString() << "'"; 230 if (After.First || After.Second || After.Third) { 231 OS << " -> "; 232 After.DebugPrint(); 233 } 234} 235 236/// DebugPrint - Print this implicit conversion sequence to standard 237/// error. Useful for debugging overloading issues. 238void ImplicitConversionSequence::DebugPrint() const { 239 llvm::raw_ostream &OS = llvm::errs(); 240 switch (ConversionKind) { 241 case StandardConversion: 242 OS << "Standard conversion: "; 243 Standard.DebugPrint(); 244 break; 245 case UserDefinedConversion: 246 OS << "User-defined conversion: "; 247 UserDefined.DebugPrint(); 248 break; 249 case EllipsisConversion: 250 OS << "Ellipsis conversion"; 251 break; 252 case AmbiguousConversion: 253 OS << "Ambiguous conversion"; 254 break; 255 case BadConversion: 256 OS << "Bad conversion"; 257 break; 258 } 259 260 OS << "\n"; 261} 262 263void AmbiguousConversionSequence::construct() { 264 new (&conversions()) ConversionSet(); 265} 266 267void AmbiguousConversionSequence::destruct() { 268 conversions().~ConversionSet(); 269} 270 271void 272AmbiguousConversionSequence::copyFrom(const AmbiguousConversionSequence &O) { 273 FromTypePtr = O.FromTypePtr; 274 ToTypePtr = O.ToTypePtr; 275 new (&conversions()) ConversionSet(O.conversions()); 276} 277 278 279// IsOverload - Determine whether the given New declaration is an 280// overload of the declarations in Old. This routine returns false if 281// New and Old cannot be overloaded, e.g., if New has the same 282// signature as some function in Old (C++ 1.3.10) or if the Old 283// declarations aren't functions (or function templates) at all. When 284// it does return false, MatchedDecl will point to the decl that New 285// cannot be overloaded with. This decl may be a UsingShadowDecl on 286// top of the underlying declaration. 287// 288// Example: Given the following input: 289// 290// void f(int, float); // #1 291// void f(int, int); // #2 292// int f(int, int); // #3 293// 294// When we process #1, there is no previous declaration of "f", 295// so IsOverload will not be used. 296// 297// When we process #2, Old contains only the FunctionDecl for #1. By 298// comparing the parameter types, we see that #1 and #2 are overloaded 299// (since they have different signatures), so this routine returns 300// false; MatchedDecl is unchanged. 301// 302// When we process #3, Old is an overload set containing #1 and #2. We 303// compare the signatures of #3 to #1 (they're overloaded, so we do 304// nothing) and then #3 to #2. Since the signatures of #3 and #2 are 305// identical (return types of functions are not part of the 306// signature), IsOverload returns false and MatchedDecl will be set to 307// point to the FunctionDecl for #2. 308Sema::OverloadKind 309Sema::CheckOverload(FunctionDecl *New, const LookupResult &Old, 310 NamedDecl *&Match) { 311 for (LookupResult::iterator I = Old.begin(), E = Old.end(); 312 I != E; ++I) { 313 NamedDecl *OldD = (*I)->getUnderlyingDecl(); 314 if (FunctionTemplateDecl *OldT = dyn_cast<FunctionTemplateDecl>(OldD)) { 315 if (!IsOverload(New, OldT->getTemplatedDecl())) { 316 Match = *I; 317 return Ovl_Match; 318 } 319 } else if (FunctionDecl *OldF = dyn_cast<FunctionDecl>(OldD)) { 320 if (!IsOverload(New, OldF)) { 321 Match = *I; 322 return Ovl_Match; 323 } 324 } else if (isa<UsingDecl>(OldD) || isa<TagDecl>(OldD)) { 325 // We can overload with these, which can show up when doing 326 // redeclaration checks for UsingDecls. 327 assert(Old.getLookupKind() == LookupUsingDeclName); 328 } else if (isa<UnresolvedUsingValueDecl>(OldD)) { 329 // Optimistically assume that an unresolved using decl will 330 // overload; if it doesn't, we'll have to diagnose during 331 // template instantiation. 332 } else { 333 // (C++ 13p1): 334 // Only function declarations can be overloaded; object and type 335 // declarations cannot be overloaded. 336 Match = *I; 337 return Ovl_NonFunction; 338 } 339 } 340 341 return Ovl_Overload; 342} 343 344bool Sema::IsOverload(FunctionDecl *New, FunctionDecl *Old) { 345 FunctionTemplateDecl *OldTemplate = Old->getDescribedFunctionTemplate(); 346 FunctionTemplateDecl *NewTemplate = New->getDescribedFunctionTemplate(); 347 348 // C++ [temp.fct]p2: 349 // A function template can be overloaded with other function templates 350 // and with normal (non-template) functions. 351 if ((OldTemplate == 0) != (NewTemplate == 0)) 352 return true; 353 354 // Is the function New an overload of the function Old? 355 QualType OldQType = Context.getCanonicalType(Old->getType()); 356 QualType NewQType = Context.getCanonicalType(New->getType()); 357 358 // Compare the signatures (C++ 1.3.10) of the two functions to 359 // determine whether they are overloads. If we find any mismatch 360 // in the signature, they are overloads. 361 362 // If either of these functions is a K&R-style function (no 363 // prototype), then we consider them to have matching signatures. 364 if (isa<FunctionNoProtoType>(OldQType.getTypePtr()) || 365 isa<FunctionNoProtoType>(NewQType.getTypePtr())) 366 return false; 367 368 FunctionProtoType* OldType = cast<FunctionProtoType>(OldQType); 369 FunctionProtoType* NewType = cast<FunctionProtoType>(NewQType); 370 371 // The signature of a function includes the types of its 372 // parameters (C++ 1.3.10), which includes the presence or absence 373 // of the ellipsis; see C++ DR 357). 374 if (OldQType != NewQType && 375 (OldType->getNumArgs() != NewType->getNumArgs() || 376 OldType->isVariadic() != NewType->isVariadic() || 377 !std::equal(OldType->arg_type_begin(), OldType->arg_type_end(), 378 NewType->arg_type_begin()))) 379 return true; 380 381 // C++ [temp.over.link]p4: 382 // The signature of a function template consists of its function 383 // signature, its return type and its template parameter list. The names 384 // of the template parameters are significant only for establishing the 385 // relationship between the template parameters and the rest of the 386 // signature. 387 // 388 // We check the return type and template parameter lists for function 389 // templates first; the remaining checks follow. 390 if (NewTemplate && 391 (!TemplateParameterListsAreEqual(NewTemplate->getTemplateParameters(), 392 OldTemplate->getTemplateParameters(), 393 false, TPL_TemplateMatch) || 394 OldType->getResultType() != NewType->getResultType())) 395 return true; 396 397 // If the function is a class member, its signature includes the 398 // cv-qualifiers (if any) on the function itself. 399 // 400 // As part of this, also check whether one of the member functions 401 // is static, in which case they are not overloads (C++ 402 // 13.1p2). While not part of the definition of the signature, 403 // this check is important to determine whether these functions 404 // can be overloaded. 405 CXXMethodDecl* OldMethod = dyn_cast<CXXMethodDecl>(Old); 406 CXXMethodDecl* NewMethod = dyn_cast<CXXMethodDecl>(New); 407 if (OldMethod && NewMethod && 408 !OldMethod->isStatic() && !NewMethod->isStatic() && 409 OldMethod->getTypeQualifiers() != NewMethod->getTypeQualifiers()) 410 return true; 411 412 // The signatures match; this is not an overload. 413 return false; 414} 415 416/// TryImplicitConversion - Attempt to perform an implicit conversion 417/// from the given expression (Expr) to the given type (ToType). This 418/// function returns an implicit conversion sequence that can be used 419/// to perform the initialization. Given 420/// 421/// void f(float f); 422/// void g(int i) { f(i); } 423/// 424/// this routine would produce an implicit conversion sequence to 425/// describe the initialization of f from i, which will be a standard 426/// conversion sequence containing an lvalue-to-rvalue conversion (C++ 427/// 4.1) followed by a floating-integral conversion (C++ 4.9). 428// 429/// Note that this routine only determines how the conversion can be 430/// performed; it does not actually perform the conversion. As such, 431/// it will not produce any diagnostics if no conversion is available, 432/// but will instead return an implicit conversion sequence of kind 433/// "BadConversion". 434/// 435/// If @p SuppressUserConversions, then user-defined conversions are 436/// not permitted. 437/// If @p AllowExplicit, then explicit user-defined conversions are 438/// permitted. 439/// If @p ForceRValue, then overloading is performed as if From was an rvalue, 440/// no matter its actual lvalueness. 441/// If @p UserCast, the implicit conversion is being done for a user-specified 442/// cast. 443ImplicitConversionSequence 444Sema::TryImplicitConversion(Expr* From, QualType ToType, 445 bool SuppressUserConversions, 446 bool AllowExplicit, bool ForceRValue, 447 bool InOverloadResolution, 448 bool UserCast) { 449 ImplicitConversionSequence ICS; 450 if (IsStandardConversion(From, ToType, InOverloadResolution, ICS.Standard)) { 451 ICS.setStandard(); 452 return ICS; 453 } 454 455 if (!getLangOptions().CPlusPlus) { 456 ICS.setBad(BadConversionSequence::no_conversion, From, ToType); 457 return ICS; 458 } 459 460 OverloadCandidateSet Conversions(From->getExprLoc()); 461 OverloadingResult UserDefResult 462 = IsUserDefinedConversion(From, ToType, ICS.UserDefined, Conversions, 463 !SuppressUserConversions, AllowExplicit, 464 ForceRValue, UserCast); 465 466 if (UserDefResult == OR_Success) { 467 ICS.setUserDefined(); 468 // C++ [over.ics.user]p4: 469 // A conversion of an expression of class type to the same class 470 // type is given Exact Match rank, and a conversion of an 471 // expression of class type to a base class of that type is 472 // given Conversion rank, in spite of the fact that a copy 473 // constructor (i.e., a user-defined conversion function) is 474 // called for those cases. 475 if (CXXConstructorDecl *Constructor 476 = dyn_cast<CXXConstructorDecl>(ICS.UserDefined.ConversionFunction)) { 477 QualType FromCanon 478 = Context.getCanonicalType(From->getType().getUnqualifiedType()); 479 QualType ToCanon = Context.getCanonicalType(ToType).getUnqualifiedType(); 480 if (Constructor->isCopyConstructor() && 481 (FromCanon == ToCanon || IsDerivedFrom(FromCanon, ToCanon))) { 482 // Turn this into a "standard" conversion sequence, so that it 483 // gets ranked with standard conversion sequences. 484 ICS.setStandard(); 485 ICS.Standard.setAsIdentityConversion(); 486 ICS.Standard.setFromType(From->getType()); 487 ICS.Standard.setAllToTypes(ToType); 488 ICS.Standard.CopyConstructor = Constructor; 489 if (ToCanon != FromCanon) 490 ICS.Standard.Second = ICK_Derived_To_Base; 491 } 492 } 493 494 // C++ [over.best.ics]p4: 495 // However, when considering the argument of a user-defined 496 // conversion function that is a candidate by 13.3.1.3 when 497 // invoked for the copying of the temporary in the second step 498 // of a class copy-initialization, or by 13.3.1.4, 13.3.1.5, or 499 // 13.3.1.6 in all cases, only standard conversion sequences and 500 // ellipsis conversion sequences are allowed. 501 if (SuppressUserConversions && ICS.isUserDefined()) { 502 ICS.setBad(BadConversionSequence::suppressed_user, From, ToType); 503 } 504 } else if (UserDefResult == OR_Ambiguous && !SuppressUserConversions) { 505 ICS.setAmbiguous(); 506 ICS.Ambiguous.setFromType(From->getType()); 507 ICS.Ambiguous.setToType(ToType); 508 for (OverloadCandidateSet::iterator Cand = Conversions.begin(); 509 Cand != Conversions.end(); ++Cand) 510 if (Cand->Viable) 511 ICS.Ambiguous.addConversion(Cand->Function); 512 } else { 513 ICS.setBad(BadConversionSequence::no_conversion, From, ToType); 514 } 515 516 return ICS; 517} 518 519/// \brief Determine whether the conversion from FromType to ToType is a valid 520/// conversion that strips "noreturn" off the nested function type. 521static bool IsNoReturnConversion(ASTContext &Context, QualType FromType, 522 QualType ToType, QualType &ResultTy) { 523 if (Context.hasSameUnqualifiedType(FromType, ToType)) 524 return false; 525 526 // Strip the noreturn off the type we're converting from; noreturn can 527 // safely be removed. 528 FromType = Context.getNoReturnType(FromType, false); 529 if (!Context.hasSameUnqualifiedType(FromType, ToType)) 530 return false; 531 532 ResultTy = FromType; 533 return true; 534} 535 536/// IsStandardConversion - Determines whether there is a standard 537/// conversion sequence (C++ [conv], C++ [over.ics.scs]) from the 538/// expression From to the type ToType. Standard conversion sequences 539/// only consider non-class types; for conversions that involve class 540/// types, use TryImplicitConversion. If a conversion exists, SCS will 541/// contain the standard conversion sequence required to perform this 542/// conversion and this routine will return true. Otherwise, this 543/// routine will return false and the value of SCS is unspecified. 544bool 545Sema::IsStandardConversion(Expr* From, QualType ToType, 546 bool InOverloadResolution, 547 StandardConversionSequence &SCS) { 548 QualType FromType = From->getType(); 549 550 // Standard conversions (C++ [conv]) 551 SCS.setAsIdentityConversion(); 552 SCS.DeprecatedStringLiteralToCharPtr = false; 553 SCS.IncompatibleObjC = false; 554 SCS.setFromType(FromType); 555 SCS.CopyConstructor = 0; 556 557 // There are no standard conversions for class types in C++, so 558 // abort early. When overloading in C, however, we do permit 559 if (FromType->isRecordType() || ToType->isRecordType()) { 560 if (getLangOptions().CPlusPlus) 561 return false; 562 563 // When we're overloading in C, we allow, as standard conversions, 564 } 565 566 // The first conversion can be an lvalue-to-rvalue conversion, 567 // array-to-pointer conversion, or function-to-pointer conversion 568 // (C++ 4p1). 569 570 DeclAccessPair AccessPair; 571 572 // Lvalue-to-rvalue conversion (C++ 4.1): 573 // An lvalue (3.10) of a non-function, non-array type T can be 574 // converted to an rvalue. 575 Expr::isLvalueResult argIsLvalue = From->isLvalue(Context); 576 if (argIsLvalue == Expr::LV_Valid && 577 !FromType->isFunctionType() && !FromType->isArrayType() && 578 Context.getCanonicalType(FromType) != Context.OverloadTy) { 579 SCS.First = ICK_Lvalue_To_Rvalue; 580 581 // If T is a non-class type, the type of the rvalue is the 582 // cv-unqualified version of T. Otherwise, the type of the rvalue 583 // is T (C++ 4.1p1). C++ can't get here with class types; in C, we 584 // just strip the qualifiers because they don't matter. 585 FromType = FromType.getUnqualifiedType(); 586 } else if (FromType->isArrayType()) { 587 // Array-to-pointer conversion (C++ 4.2) 588 SCS.First = ICK_Array_To_Pointer; 589 590 // An lvalue or rvalue of type "array of N T" or "array of unknown 591 // bound of T" can be converted to an rvalue of type "pointer to 592 // T" (C++ 4.2p1). 593 FromType = Context.getArrayDecayedType(FromType); 594 595 if (IsStringLiteralToNonConstPointerConversion(From, ToType)) { 596 // This conversion is deprecated. (C++ D.4). 597 SCS.DeprecatedStringLiteralToCharPtr = true; 598 599 // For the purpose of ranking in overload resolution 600 // (13.3.3.1.1), this conversion is considered an 601 // array-to-pointer conversion followed by a qualification 602 // conversion (4.4). (C++ 4.2p2) 603 SCS.Second = ICK_Identity; 604 SCS.Third = ICK_Qualification; 605 SCS.setAllToTypes(FromType); 606 return true; 607 } 608 } else if (FromType->isFunctionType() && argIsLvalue == Expr::LV_Valid) { 609 // Function-to-pointer conversion (C++ 4.3). 610 SCS.First = ICK_Function_To_Pointer; 611 612 // An lvalue of function type T can be converted to an rvalue of 613 // type "pointer to T." The result is a pointer to the 614 // function. (C++ 4.3p1). 615 FromType = Context.getPointerType(FromType); 616 } else if (FunctionDecl *Fn 617 = ResolveAddressOfOverloadedFunction(From, ToType, false, 618 AccessPair)) { 619 // Address of overloaded function (C++ [over.over]). 620 SCS.First = ICK_Function_To_Pointer; 621 622 // We were able to resolve the address of the overloaded function, 623 // so we can convert to the type of that function. 624 FromType = Fn->getType(); 625 if (ToType->isLValueReferenceType()) 626 FromType = Context.getLValueReferenceType(FromType); 627 else if (ToType->isRValueReferenceType()) 628 FromType = Context.getRValueReferenceType(FromType); 629 else if (ToType->isMemberPointerType()) { 630 // Resolve address only succeeds if both sides are member pointers, 631 // but it doesn't have to be the same class. See DR 247. 632 // Note that this means that the type of &Derived::fn can be 633 // Ret (Base::*)(Args) if the fn overload actually found is from the 634 // base class, even if it was brought into the derived class via a 635 // using declaration. The standard isn't clear on this issue at all. 636 CXXMethodDecl *M = cast<CXXMethodDecl>(Fn); 637 FromType = Context.getMemberPointerType(FromType, 638 Context.getTypeDeclType(M->getParent()).getTypePtr()); 639 } else 640 FromType = Context.getPointerType(FromType); 641 } else { 642 // We don't require any conversions for the first step. 643 SCS.First = ICK_Identity; 644 } 645 SCS.setToType(0, FromType); 646 647 // The second conversion can be an integral promotion, floating 648 // point promotion, integral conversion, floating point conversion, 649 // floating-integral conversion, pointer conversion, 650 // pointer-to-member conversion, or boolean conversion (C++ 4p1). 651 // For overloading in C, this can also be a "compatible-type" 652 // conversion. 653 bool IncompatibleObjC = false; 654 if (Context.hasSameUnqualifiedType(FromType, ToType)) { 655 // The unqualified versions of the types are the same: there's no 656 // conversion to do. 657 SCS.Second = ICK_Identity; 658 } else if (IsIntegralPromotion(From, FromType, ToType)) { 659 // Integral promotion (C++ 4.5). 660 SCS.Second = ICK_Integral_Promotion; 661 FromType = ToType.getUnqualifiedType(); 662 } else if (IsFloatingPointPromotion(FromType, ToType)) { 663 // Floating point promotion (C++ 4.6). 664 SCS.Second = ICK_Floating_Promotion; 665 FromType = ToType.getUnqualifiedType(); 666 } else if (IsComplexPromotion(FromType, ToType)) { 667 // Complex promotion (Clang extension) 668 SCS.Second = ICK_Complex_Promotion; 669 FromType = ToType.getUnqualifiedType(); 670 } else if ((FromType->isIntegralType() || FromType->isEnumeralType()) && 671 (ToType->isIntegralType() && !ToType->isEnumeralType())) { 672 // Integral conversions (C++ 4.7). 673 SCS.Second = ICK_Integral_Conversion; 674 FromType = ToType.getUnqualifiedType(); 675 } else if (FromType->isComplexType() && ToType->isComplexType()) { 676 // Complex conversions (C99 6.3.1.6) 677 SCS.Second = ICK_Complex_Conversion; 678 FromType = ToType.getUnqualifiedType(); 679 } else if ((FromType->isComplexType() && ToType->isArithmeticType()) || 680 (ToType->isComplexType() && FromType->isArithmeticType())) { 681 // Complex-real conversions (C99 6.3.1.7) 682 SCS.Second = ICK_Complex_Real; 683 FromType = ToType.getUnqualifiedType(); 684 } else if (FromType->isFloatingType() && ToType->isFloatingType()) { 685 // Floating point conversions (C++ 4.8). 686 SCS.Second = ICK_Floating_Conversion; 687 FromType = ToType.getUnqualifiedType(); 688 } else if ((FromType->isFloatingType() && 689 ToType->isIntegralType() && (!ToType->isBooleanType() && 690 !ToType->isEnumeralType())) || 691 ((FromType->isIntegralType() || FromType->isEnumeralType()) && 692 ToType->isFloatingType())) { 693 // Floating-integral conversions (C++ 4.9). 694 SCS.Second = ICK_Floating_Integral; 695 FromType = ToType.getUnqualifiedType(); 696 } else if (IsPointerConversion(From, FromType, ToType, InOverloadResolution, 697 FromType, IncompatibleObjC)) { 698 // Pointer conversions (C++ 4.10). 699 SCS.Second = ICK_Pointer_Conversion; 700 SCS.IncompatibleObjC = IncompatibleObjC; 701 } else if (IsMemberPointerConversion(From, FromType, ToType, 702 InOverloadResolution, FromType)) { 703 // Pointer to member conversions (4.11). 704 SCS.Second = ICK_Pointer_Member; 705 } else if (ToType->isBooleanType() && 706 (FromType->isArithmeticType() || 707 FromType->isEnumeralType() || 708 FromType->isAnyPointerType() || 709 FromType->isBlockPointerType() || 710 FromType->isMemberPointerType() || 711 FromType->isNullPtrType())) { 712 // Boolean conversions (C++ 4.12). 713 SCS.Second = ICK_Boolean_Conversion; 714 FromType = Context.BoolTy; 715 } else if (!getLangOptions().CPlusPlus && 716 Context.typesAreCompatible(ToType, FromType)) { 717 // Compatible conversions (Clang extension for C function overloading) 718 SCS.Second = ICK_Compatible_Conversion; 719 } else if (IsNoReturnConversion(Context, FromType, ToType, FromType)) { 720 // Treat a conversion that strips "noreturn" as an identity conversion. 721 SCS.Second = ICK_NoReturn_Adjustment; 722 } else { 723 // No second conversion required. 724 SCS.Second = ICK_Identity; 725 } 726 SCS.setToType(1, FromType); 727 728 QualType CanonFrom; 729 QualType CanonTo; 730 // The third conversion can be a qualification conversion (C++ 4p1). 731 if (IsQualificationConversion(FromType, ToType)) { 732 SCS.Third = ICK_Qualification; 733 FromType = ToType; 734 CanonFrom = Context.getCanonicalType(FromType); 735 CanonTo = Context.getCanonicalType(ToType); 736 } else { 737 // No conversion required 738 SCS.Third = ICK_Identity; 739 740 // C++ [over.best.ics]p6: 741 // [...] Any difference in top-level cv-qualification is 742 // subsumed by the initialization itself and does not constitute 743 // a conversion. [...] 744 CanonFrom = Context.getCanonicalType(FromType); 745 CanonTo = Context.getCanonicalType(ToType); 746 if (CanonFrom.getLocalUnqualifiedType() 747 == CanonTo.getLocalUnqualifiedType() && 748 CanonFrom.getLocalCVRQualifiers() != CanonTo.getLocalCVRQualifiers()) { 749 FromType = ToType; 750 CanonFrom = CanonTo; 751 } 752 } 753 SCS.setToType(2, FromType); 754 755 // If we have not converted the argument type to the parameter type, 756 // this is a bad conversion sequence. 757 if (CanonFrom != CanonTo) 758 return false; 759 760 return true; 761} 762 763/// IsIntegralPromotion - Determines whether the conversion from the 764/// expression From (whose potentially-adjusted type is FromType) to 765/// ToType is an integral promotion (C++ 4.5). If so, returns true and 766/// sets PromotedType to the promoted type. 767bool Sema::IsIntegralPromotion(Expr *From, QualType FromType, QualType ToType) { 768 const BuiltinType *To = ToType->getAs<BuiltinType>(); 769 // All integers are built-in. 770 if (!To) { 771 return false; 772 } 773 774 // An rvalue of type char, signed char, unsigned char, short int, or 775 // unsigned short int can be converted to an rvalue of type int if 776 // int can represent all the values of the source type; otherwise, 777 // the source rvalue can be converted to an rvalue of type unsigned 778 // int (C++ 4.5p1). 779 if (FromType->isPromotableIntegerType() && !FromType->isBooleanType() && 780 !FromType->isEnumeralType()) { 781 if (// We can promote any signed, promotable integer type to an int 782 (FromType->isSignedIntegerType() || 783 // We can promote any unsigned integer type whose size is 784 // less than int to an int. 785 (!FromType->isSignedIntegerType() && 786 Context.getTypeSize(FromType) < Context.getTypeSize(ToType)))) { 787 return To->getKind() == BuiltinType::Int; 788 } 789 790 return To->getKind() == BuiltinType::UInt; 791 } 792 793 // An rvalue of type wchar_t (3.9.1) or an enumeration type (7.2) 794 // can be converted to an rvalue of the first of the following types 795 // that can represent all the values of its underlying type: int, 796 // unsigned int, long, or unsigned long (C++ 4.5p2). 797 798 // We pre-calculate the promotion type for enum types. 799 if (const EnumType *FromEnumType = FromType->getAs<EnumType>()) 800 if (ToType->isIntegerType()) 801 return Context.hasSameUnqualifiedType(ToType, 802 FromEnumType->getDecl()->getPromotionType()); 803 804 if (FromType->isWideCharType() && ToType->isIntegerType()) { 805 // Determine whether the type we're converting from is signed or 806 // unsigned. 807 bool FromIsSigned; 808 uint64_t FromSize = Context.getTypeSize(FromType); 809 810 // FIXME: Is wchar_t signed or unsigned? We assume it's signed for now. 811 FromIsSigned = true; 812 813 // The types we'll try to promote to, in the appropriate 814 // order. Try each of these types. 815 QualType PromoteTypes[6] = { 816 Context.IntTy, Context.UnsignedIntTy, 817 Context.LongTy, Context.UnsignedLongTy , 818 Context.LongLongTy, Context.UnsignedLongLongTy 819 }; 820 for (int Idx = 0; Idx < 6; ++Idx) { 821 uint64_t ToSize = Context.getTypeSize(PromoteTypes[Idx]); 822 if (FromSize < ToSize || 823 (FromSize == ToSize && 824 FromIsSigned == PromoteTypes[Idx]->isSignedIntegerType())) { 825 // We found the type that we can promote to. If this is the 826 // type we wanted, we have a promotion. Otherwise, no 827 // promotion. 828 return Context.hasSameUnqualifiedType(ToType, PromoteTypes[Idx]); 829 } 830 } 831 } 832 833 // An rvalue for an integral bit-field (9.6) can be converted to an 834 // rvalue of type int if int can represent all the values of the 835 // bit-field; otherwise, it can be converted to unsigned int if 836 // unsigned int can represent all the values of the bit-field. If 837 // the bit-field is larger yet, no integral promotion applies to 838 // it. If the bit-field has an enumerated type, it is treated as any 839 // other value of that type for promotion purposes (C++ 4.5p3). 840 // FIXME: We should delay checking of bit-fields until we actually perform the 841 // conversion. 842 using llvm::APSInt; 843 if (From) 844 if (FieldDecl *MemberDecl = From->getBitField()) { 845 APSInt BitWidth; 846 if (FromType->isIntegralType() && !FromType->isEnumeralType() && 847 MemberDecl->getBitWidth()->isIntegerConstantExpr(BitWidth, Context)) { 848 APSInt ToSize(BitWidth.getBitWidth(), BitWidth.isUnsigned()); 849 ToSize = Context.getTypeSize(ToType); 850 851 // Are we promoting to an int from a bitfield that fits in an int? 852 if (BitWidth < ToSize || 853 (FromType->isSignedIntegerType() && BitWidth <= ToSize)) { 854 return To->getKind() == BuiltinType::Int; 855 } 856 857 // Are we promoting to an unsigned int from an unsigned bitfield 858 // that fits into an unsigned int? 859 if (FromType->isUnsignedIntegerType() && BitWidth <= ToSize) { 860 return To->getKind() == BuiltinType::UInt; 861 } 862 863 return false; 864 } 865 } 866 867 // An rvalue of type bool can be converted to an rvalue of type int, 868 // with false becoming zero and true becoming one (C++ 4.5p4). 869 if (FromType->isBooleanType() && To->getKind() == BuiltinType::Int) { 870 return true; 871 } 872 873 return false; 874} 875 876/// IsFloatingPointPromotion - Determines whether the conversion from 877/// FromType to ToType is a floating point promotion (C++ 4.6). If so, 878/// returns true and sets PromotedType to the promoted type. 879bool Sema::IsFloatingPointPromotion(QualType FromType, QualType ToType) { 880 /// An rvalue of type float can be converted to an rvalue of type 881 /// double. (C++ 4.6p1). 882 if (const BuiltinType *FromBuiltin = FromType->getAs<BuiltinType>()) 883 if (const BuiltinType *ToBuiltin = ToType->getAs<BuiltinType>()) { 884 if (FromBuiltin->getKind() == BuiltinType::Float && 885 ToBuiltin->getKind() == BuiltinType::Double) 886 return true; 887 888 // C99 6.3.1.5p1: 889 // When a float is promoted to double or long double, or a 890 // double is promoted to long double [...]. 891 if (!getLangOptions().CPlusPlus && 892 (FromBuiltin->getKind() == BuiltinType::Float || 893 FromBuiltin->getKind() == BuiltinType::Double) && 894 (ToBuiltin->getKind() == BuiltinType::LongDouble)) 895 return true; 896 } 897 898 return false; 899} 900 901/// \brief Determine if a conversion is a complex promotion. 902/// 903/// A complex promotion is defined as a complex -> complex conversion 904/// where the conversion between the underlying real types is a 905/// floating-point or integral promotion. 906bool Sema::IsComplexPromotion(QualType FromType, QualType ToType) { 907 const ComplexType *FromComplex = FromType->getAs<ComplexType>(); 908 if (!FromComplex) 909 return false; 910 911 const ComplexType *ToComplex = ToType->getAs<ComplexType>(); 912 if (!ToComplex) 913 return false; 914 915 return IsFloatingPointPromotion(FromComplex->getElementType(), 916 ToComplex->getElementType()) || 917 IsIntegralPromotion(0, FromComplex->getElementType(), 918 ToComplex->getElementType()); 919} 920 921/// BuildSimilarlyQualifiedPointerType - In a pointer conversion from 922/// the pointer type FromPtr to a pointer to type ToPointee, with the 923/// same type qualifiers as FromPtr has on its pointee type. ToType, 924/// if non-empty, will be a pointer to ToType that may or may not have 925/// the right set of qualifiers on its pointee. 926static QualType 927BuildSimilarlyQualifiedPointerType(const PointerType *FromPtr, 928 QualType ToPointee, QualType ToType, 929 ASTContext &Context) { 930 QualType CanonFromPointee = Context.getCanonicalType(FromPtr->getPointeeType()); 931 QualType CanonToPointee = Context.getCanonicalType(ToPointee); 932 Qualifiers Quals = CanonFromPointee.getQualifiers(); 933 934 // Exact qualifier match -> return the pointer type we're converting to. 935 if (CanonToPointee.getLocalQualifiers() == Quals) { 936 // ToType is exactly what we need. Return it. 937 if (!ToType.isNull()) 938 return ToType; 939 940 // Build a pointer to ToPointee. It has the right qualifiers 941 // already. 942 return Context.getPointerType(ToPointee); 943 } 944 945 // Just build a canonical type that has the right qualifiers. 946 return Context.getPointerType( 947 Context.getQualifiedType(CanonToPointee.getLocalUnqualifiedType(), 948 Quals)); 949} 950 951/// BuildSimilarlyQualifiedObjCObjectPointerType - In a pointer conversion from 952/// the FromType, which is an objective-c pointer, to ToType, which may or may 953/// not have the right set of qualifiers. 954static QualType 955BuildSimilarlyQualifiedObjCObjectPointerType(QualType FromType, 956 QualType ToType, 957 ASTContext &Context) { 958 QualType CanonFromType = Context.getCanonicalType(FromType); 959 QualType CanonToType = Context.getCanonicalType(ToType); 960 Qualifiers Quals = CanonFromType.getQualifiers(); 961 962 // Exact qualifier match -> return the pointer type we're converting to. 963 if (CanonToType.getLocalQualifiers() == Quals) 964 return ToType; 965 966 // Just build a canonical type that has the right qualifiers. 967 return Context.getQualifiedType(CanonToType.getLocalUnqualifiedType(), Quals); 968} 969 970static bool isNullPointerConstantForConversion(Expr *Expr, 971 bool InOverloadResolution, 972 ASTContext &Context) { 973 // Handle value-dependent integral null pointer constants correctly. 974 // http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#903 975 if (Expr->isValueDependent() && !Expr->isTypeDependent() && 976 Expr->getType()->isIntegralType()) 977 return !InOverloadResolution; 978 979 return Expr->isNullPointerConstant(Context, 980 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull 981 : Expr::NPC_ValueDependentIsNull); 982} 983 984/// IsPointerConversion - Determines whether the conversion of the 985/// expression From, which has the (possibly adjusted) type FromType, 986/// can be converted to the type ToType via a pointer conversion (C++ 987/// 4.10). If so, returns true and places the converted type (that 988/// might differ from ToType in its cv-qualifiers at some level) into 989/// ConvertedType. 990/// 991/// This routine also supports conversions to and from block pointers 992/// and conversions with Objective-C's 'id', 'id<protocols...>', and 993/// pointers to interfaces. FIXME: Once we've determined the 994/// appropriate overloading rules for Objective-C, we may want to 995/// split the Objective-C checks into a different routine; however, 996/// GCC seems to consider all of these conversions to be pointer 997/// conversions, so for now they live here. IncompatibleObjC will be 998/// set if the conversion is an allowed Objective-C conversion that 999/// should result in a warning. 1000bool Sema::IsPointerConversion(Expr *From, QualType FromType, QualType ToType, 1001 bool InOverloadResolution, 1002 QualType& ConvertedType, 1003 bool &IncompatibleObjC) { 1004 IncompatibleObjC = false; 1005 if (isObjCPointerConversion(FromType, ToType, ConvertedType, IncompatibleObjC)) 1006 return true; 1007 1008 // Conversion from a null pointer constant to any Objective-C pointer type. 1009 if (ToType->isObjCObjectPointerType() && 1010 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1011 ConvertedType = ToType; 1012 return true; 1013 } 1014 1015 // Blocks: Block pointers can be converted to void*. 1016 if (FromType->isBlockPointerType() && ToType->isPointerType() && 1017 ToType->getAs<PointerType>()->getPointeeType()->isVoidType()) { 1018 ConvertedType = ToType; 1019 return true; 1020 } 1021 // Blocks: A null pointer constant can be converted to a block 1022 // pointer type. 1023 if (ToType->isBlockPointerType() && 1024 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1025 ConvertedType = ToType; 1026 return true; 1027 } 1028 1029 // If the left-hand-side is nullptr_t, the right side can be a null 1030 // pointer constant. 1031 if (ToType->isNullPtrType() && 1032 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1033 ConvertedType = ToType; 1034 return true; 1035 } 1036 1037 const PointerType* ToTypePtr = ToType->getAs<PointerType>(); 1038 if (!ToTypePtr) 1039 return false; 1040 1041 // A null pointer constant can be converted to a pointer type (C++ 4.10p1). 1042 if (isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1043 ConvertedType = ToType; 1044 return true; 1045 } 1046 1047 // Beyond this point, both types need to be pointers 1048 // , including objective-c pointers. 1049 QualType ToPointeeType = ToTypePtr->getPointeeType(); 1050 if (FromType->isObjCObjectPointerType() && ToPointeeType->isVoidType()) { 1051 ConvertedType = BuildSimilarlyQualifiedObjCObjectPointerType(FromType, 1052 ToType, Context); 1053 return true; 1054 1055 } 1056 const PointerType *FromTypePtr = FromType->getAs<PointerType>(); 1057 if (!FromTypePtr) 1058 return false; 1059 1060 QualType FromPointeeType = FromTypePtr->getPointeeType(); 1061 1062 // An rvalue of type "pointer to cv T," where T is an object type, 1063 // can be converted to an rvalue of type "pointer to cv void" (C++ 1064 // 4.10p2). 1065 if (FromPointeeType->isObjectType() && ToPointeeType->isVoidType()) { 1066 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1067 ToPointeeType, 1068 ToType, Context); 1069 return true; 1070 } 1071 1072 // When we're overloading in C, we allow a special kind of pointer 1073 // conversion for compatible-but-not-identical pointee types. 1074 if (!getLangOptions().CPlusPlus && 1075 Context.typesAreCompatible(FromPointeeType, ToPointeeType)) { 1076 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1077 ToPointeeType, 1078 ToType, Context); 1079 return true; 1080 } 1081 1082 // C++ [conv.ptr]p3: 1083 // 1084 // An rvalue of type "pointer to cv D," where D is a class type, 1085 // can be converted to an rvalue of type "pointer to cv B," where 1086 // B is a base class (clause 10) of D. If B is an inaccessible 1087 // (clause 11) or ambiguous (10.2) base class of D, a program that 1088 // necessitates this conversion is ill-formed. The result of the 1089 // conversion is a pointer to the base class sub-object of the 1090 // derived class object. The null pointer value is converted to 1091 // the null pointer value of the destination type. 1092 // 1093 // Note that we do not check for ambiguity or inaccessibility 1094 // here. That is handled by CheckPointerConversion. 1095 if (getLangOptions().CPlusPlus && 1096 FromPointeeType->isRecordType() && ToPointeeType->isRecordType() && 1097 !Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType) && 1098 !RequireCompleteType(From->getLocStart(), FromPointeeType, PDiag()) && 1099 IsDerivedFrom(FromPointeeType, ToPointeeType)) { 1100 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1101 ToPointeeType, 1102 ToType, Context); 1103 return true; 1104 } 1105 1106 return false; 1107} 1108 1109/// isObjCPointerConversion - Determines whether this is an 1110/// Objective-C pointer conversion. Subroutine of IsPointerConversion, 1111/// with the same arguments and return values. 1112bool Sema::isObjCPointerConversion(QualType FromType, QualType ToType, 1113 QualType& ConvertedType, 1114 bool &IncompatibleObjC) { 1115 if (!getLangOptions().ObjC1) 1116 return false; 1117 1118 // First, we handle all conversions on ObjC object pointer types. 1119 const ObjCObjectPointerType* ToObjCPtr = ToType->getAs<ObjCObjectPointerType>(); 1120 const ObjCObjectPointerType *FromObjCPtr = 1121 FromType->getAs<ObjCObjectPointerType>(); 1122 1123 if (ToObjCPtr && FromObjCPtr) { 1124 // Objective C++: We're able to convert between "id" or "Class" and a 1125 // pointer to any interface (in both directions). 1126 if (ToObjCPtr->isObjCBuiltinType() && FromObjCPtr->isObjCBuiltinType()) { 1127 ConvertedType = ToType; 1128 return true; 1129 } 1130 // Conversions with Objective-C's id<...>. 1131 if ((FromObjCPtr->isObjCQualifiedIdType() || 1132 ToObjCPtr->isObjCQualifiedIdType()) && 1133 Context.ObjCQualifiedIdTypesAreCompatible(ToType, FromType, 1134 /*compare=*/false)) { 1135 ConvertedType = ToType; 1136 return true; 1137 } 1138 // Objective C++: We're able to convert from a pointer to an 1139 // interface to a pointer to a different interface. 1140 if (Context.canAssignObjCInterfaces(ToObjCPtr, FromObjCPtr)) { 1141 const ObjCInterfaceType* LHS = ToObjCPtr->getInterfaceType(); 1142 const ObjCInterfaceType* RHS = FromObjCPtr->getInterfaceType(); 1143 if (getLangOptions().CPlusPlus && LHS && RHS && 1144 !ToObjCPtr->getPointeeType().isAtLeastAsQualifiedAs( 1145 FromObjCPtr->getPointeeType())) 1146 return false; 1147 ConvertedType = ToType; 1148 return true; 1149 } 1150 1151 if (Context.canAssignObjCInterfaces(FromObjCPtr, ToObjCPtr)) { 1152 // Okay: this is some kind of implicit downcast of Objective-C 1153 // interfaces, which is permitted. However, we're going to 1154 // complain about it. 1155 IncompatibleObjC = true; 1156 ConvertedType = FromType; 1157 return true; 1158 } 1159 } 1160 // Beyond this point, both types need to be C pointers or block pointers. 1161 QualType ToPointeeType; 1162 if (const PointerType *ToCPtr = ToType->getAs<PointerType>()) 1163 ToPointeeType = ToCPtr->getPointeeType(); 1164 else if (const BlockPointerType *ToBlockPtr = 1165 ToType->getAs<BlockPointerType>()) { 1166 // Objective C++: We're able to convert from a pointer to any object 1167 // to a block pointer type. 1168 if (FromObjCPtr && FromObjCPtr->isObjCBuiltinType()) { 1169 ConvertedType = ToType; 1170 return true; 1171 } 1172 ToPointeeType = ToBlockPtr->getPointeeType(); 1173 } 1174 else if (FromType->getAs<BlockPointerType>() && 1175 ToObjCPtr && ToObjCPtr->isObjCBuiltinType()) { 1176 // Objective C++: We're able to convert from a block pointer type to a 1177 // pointer to any object. 1178 ConvertedType = ToType; 1179 return true; 1180 } 1181 else 1182 return false; 1183 1184 QualType FromPointeeType; 1185 if (const PointerType *FromCPtr = FromType->getAs<PointerType>()) 1186 FromPointeeType = FromCPtr->getPointeeType(); 1187 else if (const BlockPointerType *FromBlockPtr = FromType->getAs<BlockPointerType>()) 1188 FromPointeeType = FromBlockPtr->getPointeeType(); 1189 else 1190 return false; 1191 1192 // If we have pointers to pointers, recursively check whether this 1193 // is an Objective-C conversion. 1194 if (FromPointeeType->isPointerType() && ToPointeeType->isPointerType() && 1195 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, 1196 IncompatibleObjC)) { 1197 // We always complain about this conversion. 1198 IncompatibleObjC = true; 1199 ConvertedType = ToType; 1200 return true; 1201 } 1202 // Allow conversion of pointee being objective-c pointer to another one; 1203 // as in I* to id. 1204 if (FromPointeeType->getAs<ObjCObjectPointerType>() && 1205 ToPointeeType->getAs<ObjCObjectPointerType>() && 1206 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, 1207 IncompatibleObjC)) { 1208 ConvertedType = ToType; 1209 return true; 1210 } 1211 1212 // If we have pointers to functions or blocks, check whether the only 1213 // differences in the argument and result types are in Objective-C 1214 // pointer conversions. If so, we permit the conversion (but 1215 // complain about it). 1216 const FunctionProtoType *FromFunctionType 1217 = FromPointeeType->getAs<FunctionProtoType>(); 1218 const FunctionProtoType *ToFunctionType 1219 = ToPointeeType->getAs<FunctionProtoType>(); 1220 if (FromFunctionType && ToFunctionType) { 1221 // If the function types are exactly the same, this isn't an 1222 // Objective-C pointer conversion. 1223 if (Context.getCanonicalType(FromPointeeType) 1224 == Context.getCanonicalType(ToPointeeType)) 1225 return false; 1226 1227 // Perform the quick checks that will tell us whether these 1228 // function types are obviously different. 1229 if (FromFunctionType->getNumArgs() != ToFunctionType->getNumArgs() || 1230 FromFunctionType->isVariadic() != ToFunctionType->isVariadic() || 1231 FromFunctionType->getTypeQuals() != ToFunctionType->getTypeQuals()) 1232 return false; 1233 1234 bool HasObjCConversion = false; 1235 if (Context.getCanonicalType(FromFunctionType->getResultType()) 1236 == Context.getCanonicalType(ToFunctionType->getResultType())) { 1237 // Okay, the types match exactly. Nothing to do. 1238 } else if (isObjCPointerConversion(FromFunctionType->getResultType(), 1239 ToFunctionType->getResultType(), 1240 ConvertedType, IncompatibleObjC)) { 1241 // Okay, we have an Objective-C pointer conversion. 1242 HasObjCConversion = true; 1243 } else { 1244 // Function types are too different. Abort. 1245 return false; 1246 } 1247 1248 // Check argument types. 1249 for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumArgs(); 1250 ArgIdx != NumArgs; ++ArgIdx) { 1251 QualType FromArgType = FromFunctionType->getArgType(ArgIdx); 1252 QualType ToArgType = ToFunctionType->getArgType(ArgIdx); 1253 if (Context.getCanonicalType(FromArgType) 1254 == Context.getCanonicalType(ToArgType)) { 1255 // Okay, the types match exactly. Nothing to do. 1256 } else if (isObjCPointerConversion(FromArgType, ToArgType, 1257 ConvertedType, IncompatibleObjC)) { 1258 // Okay, we have an Objective-C pointer conversion. 1259 HasObjCConversion = true; 1260 } else { 1261 // Argument types are too different. Abort. 1262 return false; 1263 } 1264 } 1265 1266 if (HasObjCConversion) { 1267 // We had an Objective-C conversion. Allow this pointer 1268 // conversion, but complain about it. 1269 ConvertedType = ToType; 1270 IncompatibleObjC = true; 1271 return true; 1272 } 1273 } 1274 1275 return false; 1276} 1277 1278/// CheckPointerConversion - Check the pointer conversion from the 1279/// expression From to the type ToType. This routine checks for 1280/// ambiguous or inaccessible derived-to-base pointer 1281/// conversions for which IsPointerConversion has already returned 1282/// true. It returns true and produces a diagnostic if there was an 1283/// error, or returns false otherwise. 1284bool Sema::CheckPointerConversion(Expr *From, QualType ToType, 1285 CastExpr::CastKind &Kind, 1286 bool IgnoreBaseAccess) { 1287 QualType FromType = From->getType(); 1288 1289 if (const PointerType *FromPtrType = FromType->getAs<PointerType>()) 1290 if (const PointerType *ToPtrType = ToType->getAs<PointerType>()) { 1291 QualType FromPointeeType = FromPtrType->getPointeeType(), 1292 ToPointeeType = ToPtrType->getPointeeType(); 1293 1294 if (FromPointeeType->isRecordType() && ToPointeeType->isRecordType() && 1295 !Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType)) { 1296 // We must have a derived-to-base conversion. Check an 1297 // ambiguous or inaccessible conversion. 1298 if (CheckDerivedToBaseConversion(FromPointeeType, ToPointeeType, 1299 From->getExprLoc(), 1300 From->getSourceRange(), 1301 IgnoreBaseAccess)) 1302 return true; 1303 1304 // The conversion was successful. 1305 Kind = CastExpr::CK_DerivedToBase; 1306 } 1307 } 1308 if (const ObjCObjectPointerType *FromPtrType = 1309 FromType->getAs<ObjCObjectPointerType>()) 1310 if (const ObjCObjectPointerType *ToPtrType = 1311 ToType->getAs<ObjCObjectPointerType>()) { 1312 // Objective-C++ conversions are always okay. 1313 // FIXME: We should have a different class of conversions for the 1314 // Objective-C++ implicit conversions. 1315 if (FromPtrType->isObjCBuiltinType() || ToPtrType->isObjCBuiltinType()) 1316 return false; 1317 1318 } 1319 return false; 1320} 1321 1322/// IsMemberPointerConversion - Determines whether the conversion of the 1323/// expression From, which has the (possibly adjusted) type FromType, can be 1324/// converted to the type ToType via a member pointer conversion (C++ 4.11). 1325/// If so, returns true and places the converted type (that might differ from 1326/// ToType in its cv-qualifiers at some level) into ConvertedType. 1327bool Sema::IsMemberPointerConversion(Expr *From, QualType FromType, 1328 QualType ToType, 1329 bool InOverloadResolution, 1330 QualType &ConvertedType) { 1331 const MemberPointerType *ToTypePtr = ToType->getAs<MemberPointerType>(); 1332 if (!ToTypePtr) 1333 return false; 1334 1335 // A null pointer constant can be converted to a member pointer (C++ 4.11p1) 1336 if (From->isNullPointerConstant(Context, 1337 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull 1338 : Expr::NPC_ValueDependentIsNull)) { 1339 ConvertedType = ToType; 1340 return true; 1341 } 1342 1343 // Otherwise, both types have to be member pointers. 1344 const MemberPointerType *FromTypePtr = FromType->getAs<MemberPointerType>(); 1345 if (!FromTypePtr) 1346 return false; 1347 1348 // A pointer to member of B can be converted to a pointer to member of D, 1349 // where D is derived from B (C++ 4.11p2). 1350 QualType FromClass(FromTypePtr->getClass(), 0); 1351 QualType ToClass(ToTypePtr->getClass(), 0); 1352 // FIXME: What happens when these are dependent? Is this function even called? 1353 1354 if (IsDerivedFrom(ToClass, FromClass)) { 1355 ConvertedType = Context.getMemberPointerType(FromTypePtr->getPointeeType(), 1356 ToClass.getTypePtr()); 1357 return true; 1358 } 1359 1360 return false; 1361} 1362 1363/// CheckMemberPointerConversion - Check the member pointer conversion from the 1364/// expression From to the type ToType. This routine checks for ambiguous or 1365/// virtual or inaccessible base-to-derived member pointer conversions 1366/// for which IsMemberPointerConversion has already returned true. It returns 1367/// true and produces a diagnostic if there was an error, or returns false 1368/// otherwise. 1369bool Sema::CheckMemberPointerConversion(Expr *From, QualType ToType, 1370 CastExpr::CastKind &Kind, 1371 bool IgnoreBaseAccess) { 1372 QualType FromType = From->getType(); 1373 const MemberPointerType *FromPtrType = FromType->getAs<MemberPointerType>(); 1374 if (!FromPtrType) { 1375 // This must be a null pointer to member pointer conversion 1376 assert(From->isNullPointerConstant(Context, 1377 Expr::NPC_ValueDependentIsNull) && 1378 "Expr must be null pointer constant!"); 1379 Kind = CastExpr::CK_NullToMemberPointer; 1380 return false; 1381 } 1382 1383 const MemberPointerType *ToPtrType = ToType->getAs<MemberPointerType>(); 1384 assert(ToPtrType && "No member pointer cast has a target type " 1385 "that is not a member pointer."); 1386 1387 QualType FromClass = QualType(FromPtrType->getClass(), 0); 1388 QualType ToClass = QualType(ToPtrType->getClass(), 0); 1389 1390 // FIXME: What about dependent types? 1391 assert(FromClass->isRecordType() && "Pointer into non-class."); 1392 assert(ToClass->isRecordType() && "Pointer into non-class."); 1393 1394 CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/ true, 1395 /*DetectVirtual=*/true); 1396 bool DerivationOkay = IsDerivedFrom(ToClass, FromClass, Paths); 1397 assert(DerivationOkay && 1398 "Should not have been called if derivation isn't OK."); 1399 (void)DerivationOkay; 1400 1401 if (Paths.isAmbiguous(Context.getCanonicalType(FromClass). 1402 getUnqualifiedType())) { 1403 std::string PathDisplayStr = getAmbiguousPathsDisplayString(Paths); 1404 Diag(From->getExprLoc(), diag::err_ambiguous_memptr_conv) 1405 << 0 << FromClass << ToClass << PathDisplayStr << From->getSourceRange(); 1406 return true; 1407 } 1408 1409 if (const RecordType *VBase = Paths.getDetectedVirtual()) { 1410 Diag(From->getExprLoc(), diag::err_memptr_conv_via_virtual) 1411 << FromClass << ToClass << QualType(VBase, 0) 1412 << From->getSourceRange(); 1413 return true; 1414 } 1415 1416 if (!IgnoreBaseAccess) 1417 CheckBaseClassAccess(From->getExprLoc(), FromClass, ToClass, 1418 Paths.front(), 1419 diag::err_downcast_from_inaccessible_base); 1420 1421 // Must be a base to derived member conversion. 1422 Kind = CastExpr::CK_BaseToDerivedMemberPointer; 1423 return false; 1424} 1425 1426/// IsQualificationConversion - Determines whether the conversion from 1427/// an rvalue of type FromType to ToType is a qualification conversion 1428/// (C++ 4.4). 1429bool 1430Sema::IsQualificationConversion(QualType FromType, QualType ToType) { 1431 FromType = Context.getCanonicalType(FromType); 1432 ToType = Context.getCanonicalType(ToType); 1433 1434 // If FromType and ToType are the same type, this is not a 1435 // qualification conversion. 1436 if (FromType.getUnqualifiedType() == ToType.getUnqualifiedType()) 1437 return false; 1438 1439 // (C++ 4.4p4): 1440 // A conversion can add cv-qualifiers at levels other than the first 1441 // in multi-level pointers, subject to the following rules: [...] 1442 bool PreviousToQualsIncludeConst = true; 1443 bool UnwrappedAnyPointer = false; 1444 while (UnwrapSimilarPointerTypes(FromType, ToType)) { 1445 // Within each iteration of the loop, we check the qualifiers to 1446 // determine if this still looks like a qualification 1447 // conversion. Then, if all is well, we unwrap one more level of 1448 // pointers or pointers-to-members and do it all again 1449 // until there are no more pointers or pointers-to-members left to 1450 // unwrap. 1451 UnwrappedAnyPointer = true; 1452 1453 // -- for every j > 0, if const is in cv 1,j then const is in cv 1454 // 2,j, and similarly for volatile. 1455 if (!ToType.isAtLeastAsQualifiedAs(FromType)) 1456 return false; 1457 1458 // -- if the cv 1,j and cv 2,j are different, then const is in 1459 // every cv for 0 < k < j. 1460 if (FromType.getCVRQualifiers() != ToType.getCVRQualifiers() 1461 && !PreviousToQualsIncludeConst) 1462 return false; 1463 1464 // Keep track of whether all prior cv-qualifiers in the "to" type 1465 // include const. 1466 PreviousToQualsIncludeConst 1467 = PreviousToQualsIncludeConst && ToType.isConstQualified(); 1468 } 1469 1470 // We are left with FromType and ToType being the pointee types 1471 // after unwrapping the original FromType and ToType the same number 1472 // of types. If we unwrapped any pointers, and if FromType and 1473 // ToType have the same unqualified type (since we checked 1474 // qualifiers above), then this is a qualification conversion. 1475 return UnwrappedAnyPointer && Context.hasSameUnqualifiedType(FromType,ToType); 1476} 1477 1478/// Determines whether there is a user-defined conversion sequence 1479/// (C++ [over.ics.user]) that converts expression From to the type 1480/// ToType. If such a conversion exists, User will contain the 1481/// user-defined conversion sequence that performs such a conversion 1482/// and this routine will return true. Otherwise, this routine returns 1483/// false and User is unspecified. 1484/// 1485/// \param AllowConversionFunctions true if the conversion should 1486/// consider conversion functions at all. If false, only constructors 1487/// will be considered. 1488/// 1489/// \param AllowExplicit true if the conversion should consider C++0x 1490/// "explicit" conversion functions as well as non-explicit conversion 1491/// functions (C++0x [class.conv.fct]p2). 1492/// 1493/// \param ForceRValue true if the expression should be treated as an rvalue 1494/// for overload resolution. 1495/// \param UserCast true if looking for user defined conversion for a static 1496/// cast. 1497OverloadingResult Sema::IsUserDefinedConversion(Expr *From, QualType ToType, 1498 UserDefinedConversionSequence& User, 1499 OverloadCandidateSet& CandidateSet, 1500 bool AllowConversionFunctions, 1501 bool AllowExplicit, 1502 bool ForceRValue, 1503 bool UserCast) { 1504 if (const RecordType *ToRecordType = ToType->getAs<RecordType>()) { 1505 if (RequireCompleteType(From->getLocStart(), ToType, PDiag())) { 1506 // We're not going to find any constructors. 1507 } else if (CXXRecordDecl *ToRecordDecl 1508 = dyn_cast<CXXRecordDecl>(ToRecordType->getDecl())) { 1509 // C++ [over.match.ctor]p1: 1510 // When objects of class type are direct-initialized (8.5), or 1511 // copy-initialized from an expression of the same or a 1512 // derived class type (8.5), overload resolution selects the 1513 // constructor. [...] For copy-initialization, the candidate 1514 // functions are all the converting constructors (12.3.1) of 1515 // that class. The argument list is the expression-list within 1516 // the parentheses of the initializer. 1517 bool SuppressUserConversions = !UserCast; 1518 if (Context.hasSameUnqualifiedType(ToType, From->getType()) || 1519 IsDerivedFrom(From->getType(), ToType)) { 1520 SuppressUserConversions = false; 1521 AllowConversionFunctions = false; 1522 } 1523 1524 DeclarationName ConstructorName 1525 = Context.DeclarationNames.getCXXConstructorName( 1526 Context.getCanonicalType(ToType).getUnqualifiedType()); 1527 DeclContext::lookup_iterator Con, ConEnd; 1528 for (llvm::tie(Con, ConEnd) 1529 = ToRecordDecl->lookup(ConstructorName); 1530 Con != ConEnd; ++Con) { 1531 NamedDecl *D = *Con; 1532 DeclAccessPair FoundDecl = DeclAccessPair::make(D, D->getAccess()); 1533 1534 // Find the constructor (which may be a template). 1535 CXXConstructorDecl *Constructor = 0; 1536 FunctionTemplateDecl *ConstructorTmpl 1537 = dyn_cast<FunctionTemplateDecl>(D); 1538 if (ConstructorTmpl) 1539 Constructor 1540 = cast<CXXConstructorDecl>(ConstructorTmpl->getTemplatedDecl()); 1541 else 1542 Constructor = cast<CXXConstructorDecl>(D); 1543 1544 if (!Constructor->isInvalidDecl() && 1545 Constructor->isConvertingConstructor(AllowExplicit)) { 1546 if (ConstructorTmpl) 1547 AddTemplateOverloadCandidate(ConstructorTmpl, FoundDecl, 1548 /*ExplicitArgs*/ 0, 1549 &From, 1, CandidateSet, 1550 SuppressUserConversions, ForceRValue); 1551 else 1552 // Allow one user-defined conversion when user specifies a 1553 // From->ToType conversion via an static cast (c-style, etc). 1554 AddOverloadCandidate(Constructor, FoundDecl, 1555 &From, 1, CandidateSet, 1556 SuppressUserConversions, ForceRValue); 1557 } 1558 } 1559 } 1560 } 1561 1562 if (!AllowConversionFunctions) { 1563 // Don't allow any conversion functions to enter the overload set. 1564 } else if (RequireCompleteType(From->getLocStart(), From->getType(), 1565 PDiag(0) 1566 << From->getSourceRange())) { 1567 // No conversion functions from incomplete types. 1568 } else if (const RecordType *FromRecordType 1569 = From->getType()->getAs<RecordType>()) { 1570 if (CXXRecordDecl *FromRecordDecl 1571 = dyn_cast<CXXRecordDecl>(FromRecordType->getDecl())) { 1572 // Add all of the conversion functions as candidates. 1573 const UnresolvedSetImpl *Conversions 1574 = FromRecordDecl->getVisibleConversionFunctions(); 1575 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 1576 E = Conversions->end(); I != E; ++I) { 1577 DeclAccessPair FoundDecl = I.getPair(); 1578 NamedDecl *D = FoundDecl.getDecl(); 1579 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext()); 1580 if (isa<UsingShadowDecl>(D)) 1581 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 1582 1583 CXXConversionDecl *Conv; 1584 FunctionTemplateDecl *ConvTemplate; 1585 if ((ConvTemplate = dyn_cast<FunctionTemplateDecl>(D))) 1586 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 1587 else 1588 Conv = cast<CXXConversionDecl>(D); 1589 1590 if (AllowExplicit || !Conv->isExplicit()) { 1591 if (ConvTemplate) 1592 AddTemplateConversionCandidate(ConvTemplate, FoundDecl, 1593 ActingContext, From, ToType, 1594 CandidateSet); 1595 else 1596 AddConversionCandidate(Conv, FoundDecl, ActingContext, 1597 From, ToType, CandidateSet); 1598 } 1599 } 1600 } 1601 } 1602 1603 OverloadCandidateSet::iterator Best; 1604 switch (BestViableFunction(CandidateSet, From->getLocStart(), Best)) { 1605 case OR_Success: 1606 // Record the standard conversion we used and the conversion function. 1607 if (CXXConstructorDecl *Constructor 1608 = dyn_cast<CXXConstructorDecl>(Best->Function)) { 1609 // C++ [over.ics.user]p1: 1610 // If the user-defined conversion is specified by a 1611 // constructor (12.3.1), the initial standard conversion 1612 // sequence converts the source type to the type required by 1613 // the argument of the constructor. 1614 // 1615 QualType ThisType = Constructor->getThisType(Context); 1616 if (Best->Conversions[0].isEllipsis()) 1617 User.EllipsisConversion = true; 1618 else { 1619 User.Before = Best->Conversions[0].Standard; 1620 User.EllipsisConversion = false; 1621 } 1622 User.ConversionFunction = Constructor; 1623 User.After.setAsIdentityConversion(); 1624 User.After.setFromType( 1625 ThisType->getAs<PointerType>()->getPointeeType()); 1626 User.After.setAllToTypes(ToType); 1627 return OR_Success; 1628 } else if (CXXConversionDecl *Conversion 1629 = dyn_cast<CXXConversionDecl>(Best->Function)) { 1630 // C++ [over.ics.user]p1: 1631 // 1632 // [...] If the user-defined conversion is specified by a 1633 // conversion function (12.3.2), the initial standard 1634 // conversion sequence converts the source type to the 1635 // implicit object parameter of the conversion function. 1636 User.Before = Best->Conversions[0].Standard; 1637 User.ConversionFunction = Conversion; 1638 User.EllipsisConversion = false; 1639 1640 // C++ [over.ics.user]p2: 1641 // The second standard conversion sequence converts the 1642 // result of the user-defined conversion to the target type 1643 // for the sequence. Since an implicit conversion sequence 1644 // is an initialization, the special rules for 1645 // initialization by user-defined conversion apply when 1646 // selecting the best user-defined conversion for a 1647 // user-defined conversion sequence (see 13.3.3 and 1648 // 13.3.3.1). 1649 User.After = Best->FinalConversion; 1650 return OR_Success; 1651 } else { 1652 assert(false && "Not a constructor or conversion function?"); 1653 return OR_No_Viable_Function; 1654 } 1655 1656 case OR_No_Viable_Function: 1657 return OR_No_Viable_Function; 1658 case OR_Deleted: 1659 // No conversion here! We're done. 1660 return OR_Deleted; 1661 1662 case OR_Ambiguous: 1663 return OR_Ambiguous; 1664 } 1665 1666 return OR_No_Viable_Function; 1667} 1668 1669bool 1670Sema::DiagnoseMultipleUserDefinedConversion(Expr *From, QualType ToType) { 1671 ImplicitConversionSequence ICS; 1672 OverloadCandidateSet CandidateSet(From->getExprLoc()); 1673 OverloadingResult OvResult = 1674 IsUserDefinedConversion(From, ToType, ICS.UserDefined, 1675 CandidateSet, true, false, false); 1676 if (OvResult == OR_Ambiguous) 1677 Diag(From->getSourceRange().getBegin(), 1678 diag::err_typecheck_ambiguous_condition) 1679 << From->getType() << ToType << From->getSourceRange(); 1680 else if (OvResult == OR_No_Viable_Function && !CandidateSet.empty()) 1681 Diag(From->getSourceRange().getBegin(), 1682 diag::err_typecheck_nonviable_condition) 1683 << From->getType() << ToType << From->getSourceRange(); 1684 else 1685 return false; 1686 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, &From, 1); 1687 return true; 1688} 1689 1690/// CompareImplicitConversionSequences - Compare two implicit 1691/// conversion sequences to determine whether one is better than the 1692/// other or if they are indistinguishable (C++ 13.3.3.2). 1693ImplicitConversionSequence::CompareKind 1694Sema::CompareImplicitConversionSequences(const ImplicitConversionSequence& ICS1, 1695 const ImplicitConversionSequence& ICS2) 1696{ 1697 // (C++ 13.3.3.2p2): When comparing the basic forms of implicit 1698 // conversion sequences (as defined in 13.3.3.1) 1699 // -- a standard conversion sequence (13.3.3.1.1) is a better 1700 // conversion sequence than a user-defined conversion sequence or 1701 // an ellipsis conversion sequence, and 1702 // -- a user-defined conversion sequence (13.3.3.1.2) is a better 1703 // conversion sequence than an ellipsis conversion sequence 1704 // (13.3.3.1.3). 1705 // 1706 // C++0x [over.best.ics]p10: 1707 // For the purpose of ranking implicit conversion sequences as 1708 // described in 13.3.3.2, the ambiguous conversion sequence is 1709 // treated as a user-defined sequence that is indistinguishable 1710 // from any other user-defined conversion sequence. 1711 if (ICS1.getKind() < ICS2.getKind()) { 1712 if (!(ICS1.isUserDefined() && ICS2.isAmbiguous())) 1713 return ImplicitConversionSequence::Better; 1714 } else if (ICS2.getKind() < ICS1.getKind()) { 1715 if (!(ICS2.isUserDefined() && ICS1.isAmbiguous())) 1716 return ImplicitConversionSequence::Worse; 1717 } 1718 1719 if (ICS1.isAmbiguous() || ICS2.isAmbiguous()) 1720 return ImplicitConversionSequence::Indistinguishable; 1721 1722 // Two implicit conversion sequences of the same form are 1723 // indistinguishable conversion sequences unless one of the 1724 // following rules apply: (C++ 13.3.3.2p3): 1725 if (ICS1.isStandard()) 1726 return CompareStandardConversionSequences(ICS1.Standard, ICS2.Standard); 1727 else if (ICS1.isUserDefined()) { 1728 // User-defined conversion sequence U1 is a better conversion 1729 // sequence than another user-defined conversion sequence U2 if 1730 // they contain the same user-defined conversion function or 1731 // constructor and if the second standard conversion sequence of 1732 // U1 is better than the second standard conversion sequence of 1733 // U2 (C++ 13.3.3.2p3). 1734 if (ICS1.UserDefined.ConversionFunction == 1735 ICS2.UserDefined.ConversionFunction) 1736 return CompareStandardConversionSequences(ICS1.UserDefined.After, 1737 ICS2.UserDefined.After); 1738 } 1739 1740 return ImplicitConversionSequence::Indistinguishable; 1741} 1742 1743// Per 13.3.3.2p3, compare the given standard conversion sequences to 1744// determine if one is a proper subset of the other. 1745static ImplicitConversionSequence::CompareKind 1746compareStandardConversionSubsets(ASTContext &Context, 1747 const StandardConversionSequence& SCS1, 1748 const StandardConversionSequence& SCS2) { 1749 ImplicitConversionSequence::CompareKind Result 1750 = ImplicitConversionSequence::Indistinguishable; 1751 1752 if (SCS1.Second != SCS2.Second) { 1753 if (SCS1.Second == ICK_Identity) 1754 Result = ImplicitConversionSequence::Better; 1755 else if (SCS2.Second == ICK_Identity) 1756 Result = ImplicitConversionSequence::Worse; 1757 else 1758 return ImplicitConversionSequence::Indistinguishable; 1759 } else if (!Context.hasSameType(SCS1.getToType(1), SCS2.getToType(1))) 1760 return ImplicitConversionSequence::Indistinguishable; 1761 1762 if (SCS1.Third == SCS2.Third) { 1763 return Context.hasSameType(SCS1.getToType(2), SCS2.getToType(2))? Result 1764 : ImplicitConversionSequence::Indistinguishable; 1765 } 1766 1767 if (SCS1.Third == ICK_Identity) 1768 return Result == ImplicitConversionSequence::Worse 1769 ? ImplicitConversionSequence::Indistinguishable 1770 : ImplicitConversionSequence::Better; 1771 1772 if (SCS2.Third == ICK_Identity) 1773 return Result == ImplicitConversionSequence::Better 1774 ? ImplicitConversionSequence::Indistinguishable 1775 : ImplicitConversionSequence::Worse; 1776 1777 return ImplicitConversionSequence::Indistinguishable; 1778} 1779 1780/// CompareStandardConversionSequences - Compare two standard 1781/// conversion sequences to determine whether one is better than the 1782/// other or if they are indistinguishable (C++ 13.3.3.2p3). 1783ImplicitConversionSequence::CompareKind 1784Sema::CompareStandardConversionSequences(const StandardConversionSequence& SCS1, 1785 const StandardConversionSequence& SCS2) 1786{ 1787 // Standard conversion sequence S1 is a better conversion sequence 1788 // than standard conversion sequence S2 if (C++ 13.3.3.2p3): 1789 1790 // -- S1 is a proper subsequence of S2 (comparing the conversion 1791 // sequences in the canonical form defined by 13.3.3.1.1, 1792 // excluding any Lvalue Transformation; the identity conversion 1793 // sequence is considered to be a subsequence of any 1794 // non-identity conversion sequence) or, if not that, 1795 if (ImplicitConversionSequence::CompareKind CK 1796 = compareStandardConversionSubsets(Context, SCS1, SCS2)) 1797 return CK; 1798 1799 // -- the rank of S1 is better than the rank of S2 (by the rules 1800 // defined below), or, if not that, 1801 ImplicitConversionRank Rank1 = SCS1.getRank(); 1802 ImplicitConversionRank Rank2 = SCS2.getRank(); 1803 if (Rank1 < Rank2) 1804 return ImplicitConversionSequence::Better; 1805 else if (Rank2 < Rank1) 1806 return ImplicitConversionSequence::Worse; 1807 1808 // (C++ 13.3.3.2p4): Two conversion sequences with the same rank 1809 // are indistinguishable unless one of the following rules 1810 // applies: 1811 1812 // A conversion that is not a conversion of a pointer, or 1813 // pointer to member, to bool is better than another conversion 1814 // that is such a conversion. 1815 if (SCS1.isPointerConversionToBool() != SCS2.isPointerConversionToBool()) 1816 return SCS2.isPointerConversionToBool() 1817 ? ImplicitConversionSequence::Better 1818 : ImplicitConversionSequence::Worse; 1819 1820 // C++ [over.ics.rank]p4b2: 1821 // 1822 // If class B is derived directly or indirectly from class A, 1823 // conversion of B* to A* is better than conversion of B* to 1824 // void*, and conversion of A* to void* is better than conversion 1825 // of B* to void*. 1826 bool SCS1ConvertsToVoid 1827 = SCS1.isPointerConversionToVoidPointer(Context); 1828 bool SCS2ConvertsToVoid 1829 = SCS2.isPointerConversionToVoidPointer(Context); 1830 if (SCS1ConvertsToVoid != SCS2ConvertsToVoid) { 1831 // Exactly one of the conversion sequences is a conversion to 1832 // a void pointer; it's the worse conversion. 1833 return SCS2ConvertsToVoid ? ImplicitConversionSequence::Better 1834 : ImplicitConversionSequence::Worse; 1835 } else if (!SCS1ConvertsToVoid && !SCS2ConvertsToVoid) { 1836 // Neither conversion sequence converts to a void pointer; compare 1837 // their derived-to-base conversions. 1838 if (ImplicitConversionSequence::CompareKind DerivedCK 1839 = CompareDerivedToBaseConversions(SCS1, SCS2)) 1840 return DerivedCK; 1841 } else if (SCS1ConvertsToVoid && SCS2ConvertsToVoid) { 1842 // Both conversion sequences are conversions to void 1843 // pointers. Compare the source types to determine if there's an 1844 // inheritance relationship in their sources. 1845 QualType FromType1 = SCS1.getFromType(); 1846 QualType FromType2 = SCS2.getFromType(); 1847 1848 // Adjust the types we're converting from via the array-to-pointer 1849 // conversion, if we need to. 1850 if (SCS1.First == ICK_Array_To_Pointer) 1851 FromType1 = Context.getArrayDecayedType(FromType1); 1852 if (SCS2.First == ICK_Array_To_Pointer) 1853 FromType2 = Context.getArrayDecayedType(FromType2); 1854 1855 QualType FromPointee1 1856 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1857 QualType FromPointee2 1858 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1859 1860 if (IsDerivedFrom(FromPointee2, FromPointee1)) 1861 return ImplicitConversionSequence::Better; 1862 else if (IsDerivedFrom(FromPointee1, FromPointee2)) 1863 return ImplicitConversionSequence::Worse; 1864 1865 // Objective-C++: If one interface is more specific than the 1866 // other, it is the better one. 1867 const ObjCInterfaceType* FromIface1 = FromPointee1->getAs<ObjCInterfaceType>(); 1868 const ObjCInterfaceType* FromIface2 = FromPointee2->getAs<ObjCInterfaceType>(); 1869 if (FromIface1 && FromIface1) { 1870 if (Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 1871 return ImplicitConversionSequence::Better; 1872 else if (Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 1873 return ImplicitConversionSequence::Worse; 1874 } 1875 } 1876 1877 // Compare based on qualification conversions (C++ 13.3.3.2p3, 1878 // bullet 3). 1879 if (ImplicitConversionSequence::CompareKind QualCK 1880 = CompareQualificationConversions(SCS1, SCS2)) 1881 return QualCK; 1882 1883 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding) { 1884 // C++0x [over.ics.rank]p3b4: 1885 // -- S1 and S2 are reference bindings (8.5.3) and neither refers to an 1886 // implicit object parameter of a non-static member function declared 1887 // without a ref-qualifier, and S1 binds an rvalue reference to an 1888 // rvalue and S2 binds an lvalue reference. 1889 // FIXME: We don't know if we're dealing with the implicit object parameter, 1890 // or if the member function in this case has a ref qualifier. 1891 // (Of course, we don't have ref qualifiers yet.) 1892 if (SCS1.RRefBinding != SCS2.RRefBinding) 1893 return SCS1.RRefBinding ? ImplicitConversionSequence::Better 1894 : ImplicitConversionSequence::Worse; 1895 1896 // C++ [over.ics.rank]p3b4: 1897 // -- S1 and S2 are reference bindings (8.5.3), and the types to 1898 // which the references refer are the same type except for 1899 // top-level cv-qualifiers, and the type to which the reference 1900 // initialized by S2 refers is more cv-qualified than the type 1901 // to which the reference initialized by S1 refers. 1902 QualType T1 = SCS1.getToType(2); 1903 QualType T2 = SCS2.getToType(2); 1904 T1 = Context.getCanonicalType(T1); 1905 T2 = Context.getCanonicalType(T2); 1906 Qualifiers T1Quals, T2Quals; 1907 QualType UnqualT1 = Context.getUnqualifiedArrayType(T1, T1Quals); 1908 QualType UnqualT2 = Context.getUnqualifiedArrayType(T2, T2Quals); 1909 if (UnqualT1 == UnqualT2) { 1910 // If the type is an array type, promote the element qualifiers to the type 1911 // for comparison. 1912 if (isa<ArrayType>(T1) && T1Quals) 1913 T1 = Context.getQualifiedType(UnqualT1, T1Quals); 1914 if (isa<ArrayType>(T2) && T2Quals) 1915 T2 = Context.getQualifiedType(UnqualT2, T2Quals); 1916 if (T2.isMoreQualifiedThan(T1)) 1917 return ImplicitConversionSequence::Better; 1918 else if (T1.isMoreQualifiedThan(T2)) 1919 return ImplicitConversionSequence::Worse; 1920 } 1921 } 1922 1923 return ImplicitConversionSequence::Indistinguishable; 1924} 1925 1926/// CompareQualificationConversions - Compares two standard conversion 1927/// sequences to determine whether they can be ranked based on their 1928/// qualification conversions (C++ 13.3.3.2p3 bullet 3). 1929ImplicitConversionSequence::CompareKind 1930Sema::CompareQualificationConversions(const StandardConversionSequence& SCS1, 1931 const StandardConversionSequence& SCS2) { 1932 // C++ 13.3.3.2p3: 1933 // -- S1 and S2 differ only in their qualification conversion and 1934 // yield similar types T1 and T2 (C++ 4.4), respectively, and the 1935 // cv-qualification signature of type T1 is a proper subset of 1936 // the cv-qualification signature of type T2, and S1 is not the 1937 // deprecated string literal array-to-pointer conversion (4.2). 1938 if (SCS1.First != SCS2.First || SCS1.Second != SCS2.Second || 1939 SCS1.Third != SCS2.Third || SCS1.Third != ICK_Qualification) 1940 return ImplicitConversionSequence::Indistinguishable; 1941 1942 // FIXME: the example in the standard doesn't use a qualification 1943 // conversion (!) 1944 QualType T1 = SCS1.getToType(2); 1945 QualType T2 = SCS2.getToType(2); 1946 T1 = Context.getCanonicalType(T1); 1947 T2 = Context.getCanonicalType(T2); 1948 Qualifiers T1Quals, T2Quals; 1949 QualType UnqualT1 = Context.getUnqualifiedArrayType(T1, T1Quals); 1950 QualType UnqualT2 = Context.getUnqualifiedArrayType(T2, T2Quals); 1951 1952 // If the types are the same, we won't learn anything by unwrapped 1953 // them. 1954 if (UnqualT1 == UnqualT2) 1955 return ImplicitConversionSequence::Indistinguishable; 1956 1957 // If the type is an array type, promote the element qualifiers to the type 1958 // for comparison. 1959 if (isa<ArrayType>(T1) && T1Quals) 1960 T1 = Context.getQualifiedType(UnqualT1, T1Quals); 1961 if (isa<ArrayType>(T2) && T2Quals) 1962 T2 = Context.getQualifiedType(UnqualT2, T2Quals); 1963 1964 ImplicitConversionSequence::CompareKind Result 1965 = ImplicitConversionSequence::Indistinguishable; 1966 while (UnwrapSimilarPointerTypes(T1, T2)) { 1967 // Within each iteration of the loop, we check the qualifiers to 1968 // determine if this still looks like a qualification 1969 // conversion. Then, if all is well, we unwrap one more level of 1970 // pointers or pointers-to-members and do it all again 1971 // until there are no more pointers or pointers-to-members left 1972 // to unwrap. This essentially mimics what 1973 // IsQualificationConversion does, but here we're checking for a 1974 // strict subset of qualifiers. 1975 if (T1.getCVRQualifiers() == T2.getCVRQualifiers()) 1976 // The qualifiers are the same, so this doesn't tell us anything 1977 // about how the sequences rank. 1978 ; 1979 else if (T2.isMoreQualifiedThan(T1)) { 1980 // T1 has fewer qualifiers, so it could be the better sequence. 1981 if (Result == ImplicitConversionSequence::Worse) 1982 // Neither has qualifiers that are a subset of the other's 1983 // qualifiers. 1984 return ImplicitConversionSequence::Indistinguishable; 1985 1986 Result = ImplicitConversionSequence::Better; 1987 } else if (T1.isMoreQualifiedThan(T2)) { 1988 // T2 has fewer qualifiers, so it could be the better sequence. 1989 if (Result == ImplicitConversionSequence::Better) 1990 // Neither has qualifiers that are a subset of the other's 1991 // qualifiers. 1992 return ImplicitConversionSequence::Indistinguishable; 1993 1994 Result = ImplicitConversionSequence::Worse; 1995 } else { 1996 // Qualifiers are disjoint. 1997 return ImplicitConversionSequence::Indistinguishable; 1998 } 1999 2000 // If the types after this point are equivalent, we're done. 2001 if (Context.hasSameUnqualifiedType(T1, T2)) 2002 break; 2003 } 2004 2005 // Check that the winning standard conversion sequence isn't using 2006 // the deprecated string literal array to pointer conversion. 2007 switch (Result) { 2008 case ImplicitConversionSequence::Better: 2009 if (SCS1.DeprecatedStringLiteralToCharPtr) 2010 Result = ImplicitConversionSequence::Indistinguishable; 2011 break; 2012 2013 case ImplicitConversionSequence::Indistinguishable: 2014 break; 2015 2016 case ImplicitConversionSequence::Worse: 2017 if (SCS2.DeprecatedStringLiteralToCharPtr) 2018 Result = ImplicitConversionSequence::Indistinguishable; 2019 break; 2020 } 2021 2022 return Result; 2023} 2024 2025/// CompareDerivedToBaseConversions - Compares two standard conversion 2026/// sequences to determine whether they can be ranked based on their 2027/// various kinds of derived-to-base conversions (C++ 2028/// [over.ics.rank]p4b3). As part of these checks, we also look at 2029/// conversions between Objective-C interface types. 2030ImplicitConversionSequence::CompareKind 2031Sema::CompareDerivedToBaseConversions(const StandardConversionSequence& SCS1, 2032 const StandardConversionSequence& SCS2) { 2033 QualType FromType1 = SCS1.getFromType(); 2034 QualType ToType1 = SCS1.getToType(1); 2035 QualType FromType2 = SCS2.getFromType(); 2036 QualType ToType2 = SCS2.getToType(1); 2037 2038 // Adjust the types we're converting from via the array-to-pointer 2039 // conversion, if we need to. 2040 if (SCS1.First == ICK_Array_To_Pointer) 2041 FromType1 = Context.getArrayDecayedType(FromType1); 2042 if (SCS2.First == ICK_Array_To_Pointer) 2043 FromType2 = Context.getArrayDecayedType(FromType2); 2044 2045 // Canonicalize all of the types. 2046 FromType1 = Context.getCanonicalType(FromType1); 2047 ToType1 = Context.getCanonicalType(ToType1); 2048 FromType2 = Context.getCanonicalType(FromType2); 2049 ToType2 = Context.getCanonicalType(ToType2); 2050 2051 // C++ [over.ics.rank]p4b3: 2052 // 2053 // If class B is derived directly or indirectly from class A and 2054 // class C is derived directly or indirectly from B, 2055 // 2056 // For Objective-C, we let A, B, and C also be Objective-C 2057 // interfaces. 2058 2059 // Compare based on pointer conversions. 2060 if (SCS1.Second == ICK_Pointer_Conversion && 2061 SCS2.Second == ICK_Pointer_Conversion && 2062 /*FIXME: Remove if Objective-C id conversions get their own rank*/ 2063 FromType1->isPointerType() && FromType2->isPointerType() && 2064 ToType1->isPointerType() && ToType2->isPointerType()) { 2065 QualType FromPointee1 2066 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2067 QualType ToPointee1 2068 = ToType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2069 QualType FromPointee2 2070 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2071 QualType ToPointee2 2072 = ToType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2073 2074 const ObjCInterfaceType* FromIface1 = FromPointee1->getAs<ObjCInterfaceType>(); 2075 const ObjCInterfaceType* FromIface2 = FromPointee2->getAs<ObjCInterfaceType>(); 2076 const ObjCInterfaceType* ToIface1 = ToPointee1->getAs<ObjCInterfaceType>(); 2077 const ObjCInterfaceType* ToIface2 = ToPointee2->getAs<ObjCInterfaceType>(); 2078 2079 // -- conversion of C* to B* is better than conversion of C* to A*, 2080 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 2081 if (IsDerivedFrom(ToPointee1, ToPointee2)) 2082 return ImplicitConversionSequence::Better; 2083 else if (IsDerivedFrom(ToPointee2, ToPointee1)) 2084 return ImplicitConversionSequence::Worse; 2085 2086 if (ToIface1 && ToIface2) { 2087 if (Context.canAssignObjCInterfaces(ToIface2, ToIface1)) 2088 return ImplicitConversionSequence::Better; 2089 else if (Context.canAssignObjCInterfaces(ToIface1, ToIface2)) 2090 return ImplicitConversionSequence::Worse; 2091 } 2092 } 2093 2094 // -- conversion of B* to A* is better than conversion of C* to A*, 2095 if (FromPointee1 != FromPointee2 && ToPointee1 == ToPointee2) { 2096 if (IsDerivedFrom(FromPointee2, FromPointee1)) 2097 return ImplicitConversionSequence::Better; 2098 else if (IsDerivedFrom(FromPointee1, FromPointee2)) 2099 return ImplicitConversionSequence::Worse; 2100 2101 if (FromIface1 && FromIface2) { 2102 if (Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 2103 return ImplicitConversionSequence::Better; 2104 else if (Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 2105 return ImplicitConversionSequence::Worse; 2106 } 2107 } 2108 } 2109 2110 // Ranking of member-pointer types. 2111 if (SCS1.Second == ICK_Pointer_Member && SCS2.Second == ICK_Pointer_Member && 2112 FromType1->isMemberPointerType() && FromType2->isMemberPointerType() && 2113 ToType1->isMemberPointerType() && ToType2->isMemberPointerType()) { 2114 const MemberPointerType * FromMemPointer1 = 2115 FromType1->getAs<MemberPointerType>(); 2116 const MemberPointerType * ToMemPointer1 = 2117 ToType1->getAs<MemberPointerType>(); 2118 const MemberPointerType * FromMemPointer2 = 2119 FromType2->getAs<MemberPointerType>(); 2120 const MemberPointerType * ToMemPointer2 = 2121 ToType2->getAs<MemberPointerType>(); 2122 const Type *FromPointeeType1 = FromMemPointer1->getClass(); 2123 const Type *ToPointeeType1 = ToMemPointer1->getClass(); 2124 const Type *FromPointeeType2 = FromMemPointer2->getClass(); 2125 const Type *ToPointeeType2 = ToMemPointer2->getClass(); 2126 QualType FromPointee1 = QualType(FromPointeeType1, 0).getUnqualifiedType(); 2127 QualType ToPointee1 = QualType(ToPointeeType1, 0).getUnqualifiedType(); 2128 QualType FromPointee2 = QualType(FromPointeeType2, 0).getUnqualifiedType(); 2129 QualType ToPointee2 = QualType(ToPointeeType2, 0).getUnqualifiedType(); 2130 // conversion of A::* to B::* is better than conversion of A::* to C::*, 2131 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 2132 if (IsDerivedFrom(ToPointee1, ToPointee2)) 2133 return ImplicitConversionSequence::Worse; 2134 else if (IsDerivedFrom(ToPointee2, ToPointee1)) 2135 return ImplicitConversionSequence::Better; 2136 } 2137 // conversion of B::* to C::* is better than conversion of A::* to C::* 2138 if (ToPointee1 == ToPointee2 && FromPointee1 != FromPointee2) { 2139 if (IsDerivedFrom(FromPointee1, FromPointee2)) 2140 return ImplicitConversionSequence::Better; 2141 else if (IsDerivedFrom(FromPointee2, FromPointee1)) 2142 return ImplicitConversionSequence::Worse; 2143 } 2144 } 2145 2146 if ((SCS1.ReferenceBinding || SCS1.CopyConstructor) && 2147 (SCS2.ReferenceBinding || SCS2.CopyConstructor) && 2148 SCS1.Second == ICK_Derived_To_Base) { 2149 // -- conversion of C to B is better than conversion of C to A, 2150 // -- binding of an expression of type C to a reference of type 2151 // B& is better than binding an expression of type C to a 2152 // reference of type A&, 2153 if (Context.hasSameUnqualifiedType(FromType1, FromType2) && 2154 !Context.hasSameUnqualifiedType(ToType1, ToType2)) { 2155 if (IsDerivedFrom(ToType1, ToType2)) 2156 return ImplicitConversionSequence::Better; 2157 else if (IsDerivedFrom(ToType2, ToType1)) 2158 return ImplicitConversionSequence::Worse; 2159 } 2160 2161 // -- conversion of B to A is better than conversion of C to A. 2162 // -- binding of an expression of type B to a reference of type 2163 // A& is better than binding an expression of type C to a 2164 // reference of type A&, 2165 if (!Context.hasSameUnqualifiedType(FromType1, FromType2) && 2166 Context.hasSameUnqualifiedType(ToType1, ToType2)) { 2167 if (IsDerivedFrom(FromType2, FromType1)) 2168 return ImplicitConversionSequence::Better; 2169 else if (IsDerivedFrom(FromType1, FromType2)) 2170 return ImplicitConversionSequence::Worse; 2171 } 2172 } 2173 2174 return ImplicitConversionSequence::Indistinguishable; 2175} 2176 2177/// 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 NamedDecl *D = I.getDecl(); 3314 if (isa<UsingShadowDecl>(D)) 3315 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 3316 3317 // Skip conversion function templates; they don't tell us anything 3318 // about which builtin types we can convert to. 3319 if (isa<FunctionTemplateDecl>(D)) 3320 continue; 3321 3322 CXXConversionDecl *Conv = cast<CXXConversionDecl>(D); 3323 if (AllowExplicitConversions || !Conv->isExplicit()) { 3324 AddTypesConvertedFrom(Conv->getConversionType(), Loc, false, false, 3325 VisibleQuals); 3326 } 3327 } 3328 } 3329 } 3330} 3331 3332/// \brief Helper function for AddBuiltinOperatorCandidates() that adds 3333/// the volatile- and non-volatile-qualified assignment operators for the 3334/// given type to the candidate set. 3335static void AddBuiltinAssignmentOperatorCandidates(Sema &S, 3336 QualType T, 3337 Expr **Args, 3338 unsigned NumArgs, 3339 OverloadCandidateSet &CandidateSet) { 3340 QualType ParamTypes[2]; 3341 3342 // T& operator=(T&, T) 3343 ParamTypes[0] = S.Context.getLValueReferenceType(T); 3344 ParamTypes[1] = T; 3345 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3346 /*IsAssignmentOperator=*/true); 3347 3348 if (!S.Context.getCanonicalType(T).isVolatileQualified()) { 3349 // volatile T& operator=(volatile T&, T) 3350 ParamTypes[0] 3351 = S.Context.getLValueReferenceType(S.Context.getVolatileType(T)); 3352 ParamTypes[1] = T; 3353 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3354 /*IsAssignmentOperator=*/true); 3355 } 3356} 3357 3358/// CollectVRQualifiers - This routine returns Volatile/Restrict qualifiers, 3359/// if any, found in visible type conversion functions found in ArgExpr's type. 3360static Qualifiers CollectVRQualifiers(ASTContext &Context, Expr* ArgExpr) { 3361 Qualifiers VRQuals; 3362 const RecordType *TyRec; 3363 if (const MemberPointerType *RHSMPType = 3364 ArgExpr->getType()->getAs<MemberPointerType>()) 3365 TyRec = cast<RecordType>(RHSMPType->getClass()); 3366 else 3367 TyRec = ArgExpr->getType()->getAs<RecordType>(); 3368 if (!TyRec) { 3369 // Just to be safe, assume the worst case. 3370 VRQuals.addVolatile(); 3371 VRQuals.addRestrict(); 3372 return VRQuals; 3373 } 3374 3375 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 3376 if (!ClassDecl->hasDefinition()) 3377 return VRQuals; 3378 3379 const UnresolvedSetImpl *Conversions = 3380 ClassDecl->getVisibleConversionFunctions(); 3381 3382 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 3383 E = Conversions->end(); I != E; ++I) { 3384 NamedDecl *D = I.getDecl(); 3385 if (isa<UsingShadowDecl>(D)) 3386 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 3387 if (CXXConversionDecl *Conv = dyn_cast<CXXConversionDecl>(D)) { 3388 QualType CanTy = Context.getCanonicalType(Conv->getConversionType()); 3389 if (const ReferenceType *ResTypeRef = CanTy->getAs<ReferenceType>()) 3390 CanTy = ResTypeRef->getPointeeType(); 3391 // Need to go down the pointer/mempointer chain and add qualifiers 3392 // as see them. 3393 bool done = false; 3394 while (!done) { 3395 if (const PointerType *ResTypePtr = CanTy->getAs<PointerType>()) 3396 CanTy = ResTypePtr->getPointeeType(); 3397 else if (const MemberPointerType *ResTypeMPtr = 3398 CanTy->getAs<MemberPointerType>()) 3399 CanTy = ResTypeMPtr->getPointeeType(); 3400 else 3401 done = true; 3402 if (CanTy.isVolatileQualified()) 3403 VRQuals.addVolatile(); 3404 if (CanTy.isRestrictQualified()) 3405 VRQuals.addRestrict(); 3406 if (VRQuals.hasRestrict() && VRQuals.hasVolatile()) 3407 return VRQuals; 3408 } 3409 } 3410 } 3411 return VRQuals; 3412} 3413 3414/// AddBuiltinOperatorCandidates - Add the appropriate built-in 3415/// operator overloads to the candidate set (C++ [over.built]), based 3416/// on the operator @p Op and the arguments given. For example, if the 3417/// operator is a binary '+', this routine might add "int 3418/// operator+(int, int)" to cover integer addition. 3419void 3420Sema::AddBuiltinOperatorCandidates(OverloadedOperatorKind Op, 3421 SourceLocation OpLoc, 3422 Expr **Args, unsigned NumArgs, 3423 OverloadCandidateSet& CandidateSet) { 3424 // The set of "promoted arithmetic types", which are the arithmetic 3425 // types are that preserved by promotion (C++ [over.built]p2). Note 3426 // that the first few of these types are the promoted integral 3427 // types; these types need to be first. 3428 // FIXME: What about complex? 3429 const unsigned FirstIntegralType = 0; 3430 const unsigned LastIntegralType = 13; 3431 const unsigned FirstPromotedIntegralType = 7, 3432 LastPromotedIntegralType = 13; 3433 const unsigned FirstPromotedArithmeticType = 7, 3434 LastPromotedArithmeticType = 16; 3435 const unsigned NumArithmeticTypes = 16; 3436 QualType ArithmeticTypes[NumArithmeticTypes] = { 3437 Context.BoolTy, Context.CharTy, Context.WCharTy, 3438// FIXME: Context.Char16Ty, Context.Char32Ty, 3439 Context.SignedCharTy, Context.ShortTy, 3440 Context.UnsignedCharTy, Context.UnsignedShortTy, 3441 Context.IntTy, Context.LongTy, Context.LongLongTy, 3442 Context.UnsignedIntTy, Context.UnsignedLongTy, Context.UnsignedLongLongTy, 3443 Context.FloatTy, Context.DoubleTy, Context.LongDoubleTy 3444 }; 3445 assert(ArithmeticTypes[FirstPromotedIntegralType] == Context.IntTy && 3446 "Invalid first promoted integral type"); 3447 assert(ArithmeticTypes[LastPromotedIntegralType - 1] 3448 == Context.UnsignedLongLongTy && 3449 "Invalid last promoted integral type"); 3450 assert(ArithmeticTypes[FirstPromotedArithmeticType] == Context.IntTy && 3451 "Invalid first promoted arithmetic type"); 3452 assert(ArithmeticTypes[LastPromotedArithmeticType - 1] 3453 == Context.LongDoubleTy && 3454 "Invalid last promoted arithmetic type"); 3455 3456 // Find all of the types that the arguments can convert to, but only 3457 // if the operator we're looking at has built-in operator candidates 3458 // that make use of these types. 3459 Qualifiers VisibleTypeConversionsQuals; 3460 VisibleTypeConversionsQuals.addConst(); 3461 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 3462 VisibleTypeConversionsQuals += CollectVRQualifiers(Context, Args[ArgIdx]); 3463 3464 BuiltinCandidateTypeSet CandidateTypes(*this); 3465 if (Op == OO_Less || Op == OO_Greater || Op == OO_LessEqual || 3466 Op == OO_GreaterEqual || Op == OO_EqualEqual || Op == OO_ExclaimEqual || 3467 Op == OO_Plus || (Op == OO_Minus && NumArgs == 2) || Op == OO_Equal || 3468 Op == OO_PlusEqual || Op == OO_MinusEqual || Op == OO_Subscript || 3469 Op == OO_ArrowStar || Op == OO_PlusPlus || Op == OO_MinusMinus || 3470 (Op == OO_Star && NumArgs == 1) || Op == OO_Conditional) { 3471 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 3472 CandidateTypes.AddTypesConvertedFrom(Args[ArgIdx]->getType(), 3473 OpLoc, 3474 true, 3475 (Op == OO_Exclaim || 3476 Op == OO_AmpAmp || 3477 Op == OO_PipePipe), 3478 VisibleTypeConversionsQuals); 3479 } 3480 3481 bool isComparison = false; 3482 switch (Op) { 3483 case OO_None: 3484 case NUM_OVERLOADED_OPERATORS: 3485 assert(false && "Expected an overloaded operator"); 3486 break; 3487 3488 case OO_Star: // '*' is either unary or binary 3489 if (NumArgs == 1) 3490 goto UnaryStar; 3491 else 3492 goto BinaryStar; 3493 break; 3494 3495 case OO_Plus: // '+' is either unary or binary 3496 if (NumArgs == 1) 3497 goto UnaryPlus; 3498 else 3499 goto BinaryPlus; 3500 break; 3501 3502 case OO_Minus: // '-' is either unary or binary 3503 if (NumArgs == 1) 3504 goto UnaryMinus; 3505 else 3506 goto BinaryMinus; 3507 break; 3508 3509 case OO_Amp: // '&' is either unary or binary 3510 if (NumArgs == 1) 3511 goto UnaryAmp; 3512 else 3513 goto BinaryAmp; 3514 3515 case OO_PlusPlus: 3516 case OO_MinusMinus: 3517 // C++ [over.built]p3: 3518 // 3519 // For every pair (T, VQ), where T is an arithmetic type, and VQ 3520 // is either volatile or empty, there exist candidate operator 3521 // functions of the form 3522 // 3523 // VQ T& operator++(VQ T&); 3524 // T operator++(VQ T&, int); 3525 // 3526 // C++ [over.built]p4: 3527 // 3528 // For every pair (T, VQ), where T is an arithmetic type other 3529 // than bool, and VQ is either volatile or empty, there exist 3530 // candidate operator functions of the form 3531 // 3532 // VQ T& operator--(VQ T&); 3533 // T operator--(VQ T&, int); 3534 for (unsigned Arith = (Op == OO_PlusPlus? 0 : 1); 3535 Arith < NumArithmeticTypes; ++Arith) { 3536 QualType ArithTy = ArithmeticTypes[Arith]; 3537 QualType ParamTypes[2] 3538 = { Context.getLValueReferenceType(ArithTy), Context.IntTy }; 3539 3540 // Non-volatile version. 3541 if (NumArgs == 1) 3542 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3543 else 3544 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 3545 // heuristic to reduce number of builtin candidates in the set. 3546 // Add volatile version only if there are conversions to a volatile type. 3547 if (VisibleTypeConversionsQuals.hasVolatile()) { 3548 // Volatile version 3549 ParamTypes[0] 3550 = Context.getLValueReferenceType(Context.getVolatileType(ArithTy)); 3551 if (NumArgs == 1) 3552 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3553 else 3554 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 3555 } 3556 } 3557 3558 // C++ [over.built]p5: 3559 // 3560 // For every pair (T, VQ), where T is a cv-qualified or 3561 // cv-unqualified object type, and VQ is either volatile or 3562 // empty, there exist candidate operator functions of the form 3563 // 3564 // T*VQ& operator++(T*VQ&); 3565 // T*VQ& operator--(T*VQ&); 3566 // T* operator++(T*VQ&, int); 3567 // T* operator--(T*VQ&, int); 3568 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3569 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3570 // Skip pointer types that aren't pointers to object types. 3571 if (!(*Ptr)->getAs<PointerType>()->getPointeeType()->isObjectType()) 3572 continue; 3573 3574 QualType ParamTypes[2] = { 3575 Context.getLValueReferenceType(*Ptr), Context.IntTy 3576 }; 3577 3578 // Without volatile 3579 if (NumArgs == 1) 3580 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3581 else 3582 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3583 3584 if (!Context.getCanonicalType(*Ptr).isVolatileQualified() && 3585 VisibleTypeConversionsQuals.hasVolatile()) { 3586 // With volatile 3587 ParamTypes[0] 3588 = Context.getLValueReferenceType(Context.getVolatileType(*Ptr)); 3589 if (NumArgs == 1) 3590 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3591 else 3592 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3593 } 3594 } 3595 break; 3596 3597 UnaryStar: 3598 // C++ [over.built]p6: 3599 // For every cv-qualified or cv-unqualified object type T, there 3600 // exist candidate operator functions of the form 3601 // 3602 // T& operator*(T*); 3603 // 3604 // C++ [over.built]p7: 3605 // For every function type T, there exist candidate operator 3606 // functions of the form 3607 // T& operator*(T*); 3608 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3609 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3610 QualType ParamTy = *Ptr; 3611 QualType PointeeTy = ParamTy->getAs<PointerType>()->getPointeeType(); 3612 AddBuiltinCandidate(Context.getLValueReferenceType(PointeeTy), 3613 &ParamTy, Args, 1, CandidateSet); 3614 } 3615 break; 3616 3617 UnaryPlus: 3618 // C++ [over.built]p8: 3619 // For every type T, there exist candidate operator functions of 3620 // the form 3621 // 3622 // T* operator+(T*); 3623 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3624 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3625 QualType ParamTy = *Ptr; 3626 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet); 3627 } 3628 3629 // Fall through 3630 3631 UnaryMinus: 3632 // C++ [over.built]p9: 3633 // For every promoted arithmetic type T, there exist candidate 3634 // operator functions of the form 3635 // 3636 // T operator+(T); 3637 // T operator-(T); 3638 for (unsigned Arith = FirstPromotedArithmeticType; 3639 Arith < LastPromotedArithmeticType; ++Arith) { 3640 QualType ArithTy = ArithmeticTypes[Arith]; 3641 AddBuiltinCandidate(ArithTy, &ArithTy, Args, 1, CandidateSet); 3642 } 3643 break; 3644 3645 case OO_Tilde: 3646 // C++ [over.built]p10: 3647 // For every promoted integral type T, there exist candidate 3648 // operator functions of the form 3649 // 3650 // T operator~(T); 3651 for (unsigned Int = FirstPromotedIntegralType; 3652 Int < LastPromotedIntegralType; ++Int) { 3653 QualType IntTy = ArithmeticTypes[Int]; 3654 AddBuiltinCandidate(IntTy, &IntTy, Args, 1, CandidateSet); 3655 } 3656 break; 3657 3658 case OO_New: 3659 case OO_Delete: 3660 case OO_Array_New: 3661 case OO_Array_Delete: 3662 case OO_Call: 3663 assert(false && "Special operators don't use AddBuiltinOperatorCandidates"); 3664 break; 3665 3666 case OO_Comma: 3667 UnaryAmp: 3668 case OO_Arrow: 3669 // C++ [over.match.oper]p3: 3670 // -- For the operator ',', the unary operator '&', or the 3671 // operator '->', the built-in candidates set is empty. 3672 break; 3673 3674 case OO_EqualEqual: 3675 case OO_ExclaimEqual: 3676 // C++ [over.match.oper]p16: 3677 // For every pointer to member type T, there exist candidate operator 3678 // functions of the form 3679 // 3680 // bool operator==(T,T); 3681 // bool operator!=(T,T); 3682 for (BuiltinCandidateTypeSet::iterator 3683 MemPtr = CandidateTypes.member_pointer_begin(), 3684 MemPtrEnd = CandidateTypes.member_pointer_end(); 3685 MemPtr != MemPtrEnd; 3686 ++MemPtr) { 3687 QualType ParamTypes[2] = { *MemPtr, *MemPtr }; 3688 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 3689 } 3690 3691 // Fall through 3692 3693 case OO_Less: 3694 case OO_Greater: 3695 case OO_LessEqual: 3696 case OO_GreaterEqual: 3697 // C++ [over.built]p15: 3698 // 3699 // For every pointer or enumeration type T, there exist 3700 // candidate operator functions of the form 3701 // 3702 // bool operator<(T, T); 3703 // bool operator>(T, T); 3704 // bool operator<=(T, T); 3705 // bool operator>=(T, T); 3706 // bool operator==(T, T); 3707 // bool operator!=(T, T); 3708 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3709 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3710 QualType ParamTypes[2] = { *Ptr, *Ptr }; 3711 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 3712 } 3713 for (BuiltinCandidateTypeSet::iterator Enum 3714 = CandidateTypes.enumeration_begin(); 3715 Enum != CandidateTypes.enumeration_end(); ++Enum) { 3716 QualType ParamTypes[2] = { *Enum, *Enum }; 3717 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 3718 } 3719 3720 // Fall through. 3721 isComparison = true; 3722 3723 BinaryPlus: 3724 BinaryMinus: 3725 if (!isComparison) { 3726 // We didn't fall through, so we must have OO_Plus or OO_Minus. 3727 3728 // C++ [over.built]p13: 3729 // 3730 // For every cv-qualified or cv-unqualified object type T 3731 // there exist candidate operator functions of the form 3732 // 3733 // T* operator+(T*, ptrdiff_t); 3734 // T& operator[](T*, ptrdiff_t); [BELOW] 3735 // T* operator-(T*, ptrdiff_t); 3736 // T* operator+(ptrdiff_t, T*); 3737 // T& operator[](ptrdiff_t, T*); [BELOW] 3738 // 3739 // C++ [over.built]p14: 3740 // 3741 // For every T, where T is a pointer to object type, there 3742 // exist candidate operator functions of the form 3743 // 3744 // ptrdiff_t operator-(T, T); 3745 for (BuiltinCandidateTypeSet::iterator Ptr 3746 = CandidateTypes.pointer_begin(); 3747 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3748 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 3749 3750 // operator+(T*, ptrdiff_t) or operator-(T*, ptrdiff_t) 3751 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3752 3753 if (Op == OO_Plus) { 3754 // T* operator+(ptrdiff_t, T*); 3755 ParamTypes[0] = ParamTypes[1]; 3756 ParamTypes[1] = *Ptr; 3757 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3758 } else { 3759 // ptrdiff_t operator-(T, T); 3760 ParamTypes[1] = *Ptr; 3761 AddBuiltinCandidate(Context.getPointerDiffType(), ParamTypes, 3762 Args, 2, CandidateSet); 3763 } 3764 } 3765 } 3766 // Fall through 3767 3768 case OO_Slash: 3769 BinaryStar: 3770 Conditional: 3771 // C++ [over.built]p12: 3772 // 3773 // For every pair of promoted arithmetic types L and R, there 3774 // exist candidate operator functions of the form 3775 // 3776 // LR operator*(L, R); 3777 // LR operator/(L, R); 3778 // LR operator+(L, R); 3779 // LR operator-(L, R); 3780 // bool operator<(L, R); 3781 // bool operator>(L, R); 3782 // bool operator<=(L, R); 3783 // bool operator>=(L, R); 3784 // bool operator==(L, R); 3785 // bool operator!=(L, R); 3786 // 3787 // where LR is the result of the usual arithmetic conversions 3788 // between types L and R. 3789 // 3790 // C++ [over.built]p24: 3791 // 3792 // For every pair of promoted arithmetic types L and R, there exist 3793 // candidate operator functions of the form 3794 // 3795 // LR operator?(bool, L, R); 3796 // 3797 // where LR is the result of the usual arithmetic conversions 3798 // between types L and R. 3799 // Our candidates ignore the first parameter. 3800 for (unsigned Left = FirstPromotedArithmeticType; 3801 Left < LastPromotedArithmeticType; ++Left) { 3802 for (unsigned Right = FirstPromotedArithmeticType; 3803 Right < LastPromotedArithmeticType; ++Right) { 3804 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 3805 QualType Result 3806 = isComparison 3807 ? Context.BoolTy 3808 : Context.UsualArithmeticConversionsType(LandR[0], LandR[1]); 3809 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 3810 } 3811 } 3812 break; 3813 3814 case OO_Percent: 3815 BinaryAmp: 3816 case OO_Caret: 3817 case OO_Pipe: 3818 case OO_LessLess: 3819 case OO_GreaterGreater: 3820 // C++ [over.built]p17: 3821 // 3822 // For every pair of promoted integral types L and R, there 3823 // exist candidate operator functions of the form 3824 // 3825 // LR operator%(L, R); 3826 // LR operator&(L, R); 3827 // LR operator^(L, R); 3828 // LR operator|(L, R); 3829 // L operator<<(L, R); 3830 // L operator>>(L, R); 3831 // 3832 // where LR is the result of the usual arithmetic conversions 3833 // between types L and R. 3834 for (unsigned Left = FirstPromotedIntegralType; 3835 Left < LastPromotedIntegralType; ++Left) { 3836 for (unsigned Right = FirstPromotedIntegralType; 3837 Right < LastPromotedIntegralType; ++Right) { 3838 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 3839 QualType Result = (Op == OO_LessLess || Op == OO_GreaterGreater) 3840 ? LandR[0] 3841 : Context.UsualArithmeticConversionsType(LandR[0], LandR[1]); 3842 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 3843 } 3844 } 3845 break; 3846 3847 case OO_Equal: 3848 // C++ [over.built]p20: 3849 // 3850 // For every pair (T, VQ), where T is an enumeration or 3851 // pointer to member type and VQ is either volatile or 3852 // empty, there exist candidate operator functions of the form 3853 // 3854 // VQ T& operator=(VQ T&, T); 3855 for (BuiltinCandidateTypeSet::iterator 3856 Enum = CandidateTypes.enumeration_begin(), 3857 EnumEnd = CandidateTypes.enumeration_end(); 3858 Enum != EnumEnd; ++Enum) 3859 AddBuiltinAssignmentOperatorCandidates(*this, *Enum, Args, 2, 3860 CandidateSet); 3861 for (BuiltinCandidateTypeSet::iterator 3862 MemPtr = CandidateTypes.member_pointer_begin(), 3863 MemPtrEnd = CandidateTypes.member_pointer_end(); 3864 MemPtr != MemPtrEnd; ++MemPtr) 3865 AddBuiltinAssignmentOperatorCandidates(*this, *MemPtr, Args, 2, 3866 CandidateSet); 3867 // Fall through. 3868 3869 case OO_PlusEqual: 3870 case OO_MinusEqual: 3871 // C++ [over.built]p19: 3872 // 3873 // For every pair (T, VQ), where T is any type and VQ is either 3874 // volatile or empty, there exist candidate operator functions 3875 // of the form 3876 // 3877 // T*VQ& operator=(T*VQ&, T*); 3878 // 3879 // C++ [over.built]p21: 3880 // 3881 // For every pair (T, VQ), where T is a cv-qualified or 3882 // cv-unqualified object type and VQ is either volatile or 3883 // empty, there exist candidate operator functions of the form 3884 // 3885 // T*VQ& operator+=(T*VQ&, ptrdiff_t); 3886 // T*VQ& operator-=(T*VQ&, ptrdiff_t); 3887 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3888 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3889 QualType ParamTypes[2]; 3890 ParamTypes[1] = (Op == OO_Equal)? *Ptr : Context.getPointerDiffType(); 3891 3892 // non-volatile version 3893 ParamTypes[0] = Context.getLValueReferenceType(*Ptr); 3894 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3895 /*IsAssigmentOperator=*/Op == OO_Equal); 3896 3897 if (!Context.getCanonicalType(*Ptr).isVolatileQualified() && 3898 VisibleTypeConversionsQuals.hasVolatile()) { 3899 // volatile version 3900 ParamTypes[0] 3901 = Context.getLValueReferenceType(Context.getVolatileType(*Ptr)); 3902 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3903 /*IsAssigmentOperator=*/Op == OO_Equal); 3904 } 3905 } 3906 // Fall through. 3907 3908 case OO_StarEqual: 3909 case OO_SlashEqual: 3910 // C++ [over.built]p18: 3911 // 3912 // For every triple (L, VQ, R), where L is an arithmetic type, 3913 // VQ is either volatile or empty, and R is a promoted 3914 // arithmetic type, there exist candidate operator functions of 3915 // the form 3916 // 3917 // VQ L& operator=(VQ L&, R); 3918 // VQ L& operator*=(VQ L&, R); 3919 // VQ L& operator/=(VQ L&, R); 3920 // VQ L& operator+=(VQ L&, R); 3921 // VQ L& operator-=(VQ L&, R); 3922 for (unsigned Left = 0; Left < NumArithmeticTypes; ++Left) { 3923 for (unsigned Right = FirstPromotedArithmeticType; 3924 Right < LastPromotedArithmeticType; ++Right) { 3925 QualType ParamTypes[2]; 3926 ParamTypes[1] = ArithmeticTypes[Right]; 3927 3928 // Add this built-in operator as a candidate (VQ is empty). 3929 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 3930 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3931 /*IsAssigmentOperator=*/Op == OO_Equal); 3932 3933 // Add this built-in operator as a candidate (VQ is 'volatile'). 3934 if (VisibleTypeConversionsQuals.hasVolatile()) { 3935 ParamTypes[0] = Context.getVolatileType(ArithmeticTypes[Left]); 3936 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 3937 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3938 /*IsAssigmentOperator=*/Op == OO_Equal); 3939 } 3940 } 3941 } 3942 break; 3943 3944 case OO_PercentEqual: 3945 case OO_LessLessEqual: 3946 case OO_GreaterGreaterEqual: 3947 case OO_AmpEqual: 3948 case OO_CaretEqual: 3949 case OO_PipeEqual: 3950 // C++ [over.built]p22: 3951 // 3952 // For every triple (L, VQ, R), where L is an integral type, VQ 3953 // is either volatile or empty, and R is a promoted integral 3954 // type, there exist candidate operator functions of the form 3955 // 3956 // VQ L& operator%=(VQ L&, R); 3957 // VQ L& operator<<=(VQ L&, R); 3958 // VQ L& operator>>=(VQ L&, R); 3959 // VQ L& operator&=(VQ L&, R); 3960 // VQ L& operator^=(VQ L&, R); 3961 // VQ L& operator|=(VQ L&, R); 3962 for (unsigned Left = FirstIntegralType; Left < LastIntegralType; ++Left) { 3963 for (unsigned Right = FirstPromotedIntegralType; 3964 Right < LastPromotedIntegralType; ++Right) { 3965 QualType ParamTypes[2]; 3966 ParamTypes[1] = ArithmeticTypes[Right]; 3967 3968 // Add this built-in operator as a candidate (VQ is empty). 3969 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 3970 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 3971 if (VisibleTypeConversionsQuals.hasVolatile()) { 3972 // Add this built-in operator as a candidate (VQ is 'volatile'). 3973 ParamTypes[0] = ArithmeticTypes[Left]; 3974 ParamTypes[0] = Context.getVolatileType(ParamTypes[0]); 3975 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 3976 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 3977 } 3978 } 3979 } 3980 break; 3981 3982 case OO_Exclaim: { 3983 // C++ [over.operator]p23: 3984 // 3985 // There also exist candidate operator functions of the form 3986 // 3987 // bool operator!(bool); 3988 // bool operator&&(bool, bool); [BELOW] 3989 // bool operator||(bool, bool); [BELOW] 3990 QualType ParamTy = Context.BoolTy; 3991 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet, 3992 /*IsAssignmentOperator=*/false, 3993 /*NumContextualBoolArguments=*/1); 3994 break; 3995 } 3996 3997 case OO_AmpAmp: 3998 case OO_PipePipe: { 3999 // C++ [over.operator]p23: 4000 // 4001 // There also exist candidate operator functions of the form 4002 // 4003 // bool operator!(bool); [ABOVE] 4004 // bool operator&&(bool, bool); 4005 // bool operator||(bool, bool); 4006 QualType ParamTypes[2] = { Context.BoolTy, Context.BoolTy }; 4007 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet, 4008 /*IsAssignmentOperator=*/false, 4009 /*NumContextualBoolArguments=*/2); 4010 break; 4011 } 4012 4013 case OO_Subscript: 4014 // C++ [over.built]p13: 4015 // 4016 // For every cv-qualified or cv-unqualified object type T there 4017 // exist candidate operator functions of the form 4018 // 4019 // T* operator+(T*, ptrdiff_t); [ABOVE] 4020 // T& operator[](T*, ptrdiff_t); 4021 // T* operator-(T*, ptrdiff_t); [ABOVE] 4022 // T* operator+(ptrdiff_t, T*); [ABOVE] 4023 // T& operator[](ptrdiff_t, T*); 4024 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 4025 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4026 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 4027 QualType PointeeType = (*Ptr)->getAs<PointerType>()->getPointeeType(); 4028 QualType ResultTy = Context.getLValueReferenceType(PointeeType); 4029 4030 // T& operator[](T*, ptrdiff_t) 4031 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 4032 4033 // T& operator[](ptrdiff_t, T*); 4034 ParamTypes[0] = ParamTypes[1]; 4035 ParamTypes[1] = *Ptr; 4036 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 4037 } 4038 break; 4039 4040 case OO_ArrowStar: 4041 // C++ [over.built]p11: 4042 // For every quintuple (C1, C2, T, CV1, CV2), where C2 is a class type, 4043 // C1 is the same type as C2 or is a derived class of C2, T is an object 4044 // type or a function type, and CV1 and CV2 are cv-qualifier-seqs, 4045 // there exist candidate operator functions of the form 4046 // CV12 T& operator->*(CV1 C1*, CV2 T C2::*); 4047 // where CV12 is the union of CV1 and CV2. 4048 { 4049 for (BuiltinCandidateTypeSet::iterator Ptr = 4050 CandidateTypes.pointer_begin(); 4051 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4052 QualType C1Ty = (*Ptr); 4053 QualType C1; 4054 QualifierCollector Q1; 4055 if (const PointerType *PointerTy = C1Ty->getAs<PointerType>()) { 4056 C1 = QualType(Q1.strip(PointerTy->getPointeeType()), 0); 4057 if (!isa<RecordType>(C1)) 4058 continue; 4059 // heuristic to reduce number of builtin candidates in the set. 4060 // Add volatile/restrict version only if there are conversions to a 4061 // volatile/restrict type. 4062 if (!VisibleTypeConversionsQuals.hasVolatile() && Q1.hasVolatile()) 4063 continue; 4064 if (!VisibleTypeConversionsQuals.hasRestrict() && Q1.hasRestrict()) 4065 continue; 4066 } 4067 for (BuiltinCandidateTypeSet::iterator 4068 MemPtr = CandidateTypes.member_pointer_begin(), 4069 MemPtrEnd = CandidateTypes.member_pointer_end(); 4070 MemPtr != MemPtrEnd; ++MemPtr) { 4071 const MemberPointerType *mptr = cast<MemberPointerType>(*MemPtr); 4072 QualType C2 = QualType(mptr->getClass(), 0); 4073 C2 = C2.getUnqualifiedType(); 4074 if (C1 != C2 && !IsDerivedFrom(C1, C2)) 4075 break; 4076 QualType ParamTypes[2] = { *Ptr, *MemPtr }; 4077 // build CV12 T& 4078 QualType T = mptr->getPointeeType(); 4079 if (!VisibleTypeConversionsQuals.hasVolatile() && 4080 T.isVolatileQualified()) 4081 continue; 4082 if (!VisibleTypeConversionsQuals.hasRestrict() && 4083 T.isRestrictQualified()) 4084 continue; 4085 T = Q1.apply(T); 4086 QualType ResultTy = Context.getLValueReferenceType(T); 4087 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 4088 } 4089 } 4090 } 4091 break; 4092 4093 case OO_Conditional: 4094 // Note that we don't consider the first argument, since it has been 4095 // contextually converted to bool long ago. The candidates below are 4096 // therefore added as binary. 4097 // 4098 // C++ [over.built]p24: 4099 // For every type T, where T is a pointer or pointer-to-member type, 4100 // there exist candidate operator functions of the form 4101 // 4102 // T operator?(bool, T, T); 4103 // 4104 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(), 4105 E = CandidateTypes.pointer_end(); Ptr != E; ++Ptr) { 4106 QualType ParamTypes[2] = { *Ptr, *Ptr }; 4107 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 4108 } 4109 for (BuiltinCandidateTypeSet::iterator Ptr = 4110 CandidateTypes.member_pointer_begin(), 4111 E = CandidateTypes.member_pointer_end(); Ptr != E; ++Ptr) { 4112 QualType ParamTypes[2] = { *Ptr, *Ptr }; 4113 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 4114 } 4115 goto Conditional; 4116 } 4117} 4118 4119/// \brief Add function candidates found via argument-dependent lookup 4120/// to the set of overloading candidates. 4121/// 4122/// This routine performs argument-dependent name lookup based on the 4123/// given function name (which may also be an operator name) and adds 4124/// all of the overload candidates found by ADL to the overload 4125/// candidate set (C++ [basic.lookup.argdep]). 4126void 4127Sema::AddArgumentDependentLookupCandidates(DeclarationName Name, 4128 bool Operator, 4129 Expr **Args, unsigned NumArgs, 4130 const TemplateArgumentListInfo *ExplicitTemplateArgs, 4131 OverloadCandidateSet& CandidateSet, 4132 bool PartialOverloading) { 4133 ADLResult Fns; 4134 4135 // FIXME: This approach for uniquing ADL results (and removing 4136 // redundant candidates from the set) relies on pointer-equality, 4137 // which means we need to key off the canonical decl. However, 4138 // always going back to the canonical decl might not get us the 4139 // right set of default arguments. What default arguments are 4140 // we supposed to consider on ADL candidates, anyway? 4141 4142 // FIXME: Pass in the explicit template arguments? 4143 ArgumentDependentLookup(Name, Operator, Args, NumArgs, Fns); 4144 4145 // Erase all of the candidates we already knew about. 4146 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 4147 CandEnd = CandidateSet.end(); 4148 Cand != CandEnd; ++Cand) 4149 if (Cand->Function) { 4150 Fns.erase(Cand->Function); 4151 if (FunctionTemplateDecl *FunTmpl = Cand->Function->getPrimaryTemplate()) 4152 Fns.erase(FunTmpl); 4153 } 4154 4155 // For each of the ADL candidates we found, add it to the overload 4156 // set. 4157 for (ADLResult::iterator I = Fns.begin(), E = Fns.end(); I != E; ++I) { 4158 DeclAccessPair FoundDecl = DeclAccessPair::make(*I, AS_none); 4159 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*I)) { 4160 if (ExplicitTemplateArgs) 4161 continue; 4162 4163 AddOverloadCandidate(FD, FoundDecl, Args, NumArgs, CandidateSet, 4164 false, false, PartialOverloading); 4165 } else 4166 AddTemplateOverloadCandidate(cast<FunctionTemplateDecl>(*I), 4167 FoundDecl, ExplicitTemplateArgs, 4168 Args, NumArgs, CandidateSet); 4169 } 4170} 4171 4172/// isBetterOverloadCandidate - Determines whether the first overload 4173/// candidate is a better candidate than the second (C++ 13.3.3p1). 4174bool 4175Sema::isBetterOverloadCandidate(const OverloadCandidate& Cand1, 4176 const OverloadCandidate& Cand2, 4177 SourceLocation Loc) { 4178 // Define viable functions to be better candidates than non-viable 4179 // functions. 4180 if (!Cand2.Viable) 4181 return Cand1.Viable; 4182 else if (!Cand1.Viable) 4183 return false; 4184 4185 // C++ [over.match.best]p1: 4186 // 4187 // -- if F is a static member function, ICS1(F) is defined such 4188 // that ICS1(F) is neither better nor worse than ICS1(G) for 4189 // any function G, and, symmetrically, ICS1(G) is neither 4190 // better nor worse than ICS1(F). 4191 unsigned StartArg = 0; 4192 if (Cand1.IgnoreObjectArgument || Cand2.IgnoreObjectArgument) 4193 StartArg = 1; 4194 4195 // C++ [over.match.best]p1: 4196 // A viable function F1 is defined to be a better function than another 4197 // viable function F2 if for all arguments i, ICSi(F1) is not a worse 4198 // conversion sequence than ICSi(F2), and then... 4199 unsigned NumArgs = Cand1.Conversions.size(); 4200 assert(Cand2.Conversions.size() == NumArgs && "Overload candidate mismatch"); 4201 bool HasBetterConversion = false; 4202 for (unsigned ArgIdx = StartArg; ArgIdx < NumArgs; ++ArgIdx) { 4203 switch (CompareImplicitConversionSequences(Cand1.Conversions[ArgIdx], 4204 Cand2.Conversions[ArgIdx])) { 4205 case ImplicitConversionSequence::Better: 4206 // Cand1 has a better conversion sequence. 4207 HasBetterConversion = true; 4208 break; 4209 4210 case ImplicitConversionSequence::Worse: 4211 // Cand1 can't be better than Cand2. 4212 return false; 4213 4214 case ImplicitConversionSequence::Indistinguishable: 4215 // Do nothing. 4216 break; 4217 } 4218 } 4219 4220 // -- for some argument j, ICSj(F1) is a better conversion sequence than 4221 // ICSj(F2), or, if not that, 4222 if (HasBetterConversion) 4223 return true; 4224 4225 // - F1 is a non-template function and F2 is a function template 4226 // specialization, or, if not that, 4227 if (Cand1.Function && !Cand1.Function->getPrimaryTemplate() && 4228 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 4229 return true; 4230 4231 // -- F1 and F2 are function template specializations, and the function 4232 // template for F1 is more specialized than the template for F2 4233 // according to the partial ordering rules described in 14.5.5.2, or, 4234 // if not that, 4235 if (Cand1.Function && Cand1.Function->getPrimaryTemplate() && 4236 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 4237 if (FunctionTemplateDecl *BetterTemplate 4238 = getMoreSpecializedTemplate(Cand1.Function->getPrimaryTemplate(), 4239 Cand2.Function->getPrimaryTemplate(), 4240 Loc, 4241 isa<CXXConversionDecl>(Cand1.Function)? TPOC_Conversion 4242 : TPOC_Call)) 4243 return BetterTemplate == Cand1.Function->getPrimaryTemplate(); 4244 4245 // -- the context is an initialization by user-defined conversion 4246 // (see 8.5, 13.3.1.5) and the standard conversion sequence 4247 // from the return type of F1 to the destination type (i.e., 4248 // the type of the entity being initialized) is a better 4249 // conversion sequence than the standard conversion sequence 4250 // from the return type of F2 to the destination type. 4251 if (Cand1.Function && Cand2.Function && 4252 isa<CXXConversionDecl>(Cand1.Function) && 4253 isa<CXXConversionDecl>(Cand2.Function)) { 4254 switch (CompareStandardConversionSequences(Cand1.FinalConversion, 4255 Cand2.FinalConversion)) { 4256 case ImplicitConversionSequence::Better: 4257 // Cand1 has a better conversion sequence. 4258 return true; 4259 4260 case ImplicitConversionSequence::Worse: 4261 // Cand1 can't be better than Cand2. 4262 return false; 4263 4264 case ImplicitConversionSequence::Indistinguishable: 4265 // Do nothing 4266 break; 4267 } 4268 } 4269 4270 return false; 4271} 4272 4273/// \brief Computes the best viable function (C++ 13.3.3) 4274/// within an overload candidate set. 4275/// 4276/// \param CandidateSet the set of candidate functions. 4277/// 4278/// \param Loc the location of the function name (or operator symbol) for 4279/// which overload resolution occurs. 4280/// 4281/// \param Best f overload resolution was successful or found a deleted 4282/// function, Best points to the candidate function found. 4283/// 4284/// \returns The result of overload resolution. 4285OverloadingResult Sema::BestViableFunction(OverloadCandidateSet& CandidateSet, 4286 SourceLocation Loc, 4287 OverloadCandidateSet::iterator& Best) { 4288 // Find the best viable function. 4289 Best = CandidateSet.end(); 4290 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 4291 Cand != CandidateSet.end(); ++Cand) { 4292 if (Cand->Viable) { 4293 if (Best == CandidateSet.end() || 4294 isBetterOverloadCandidate(*Cand, *Best, Loc)) 4295 Best = Cand; 4296 } 4297 } 4298 4299 // If we didn't find any viable functions, abort. 4300 if (Best == CandidateSet.end()) 4301 return OR_No_Viable_Function; 4302 4303 // Make sure that this function is better than every other viable 4304 // function. If not, we have an ambiguity. 4305 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 4306 Cand != CandidateSet.end(); ++Cand) { 4307 if (Cand->Viable && 4308 Cand != Best && 4309 !isBetterOverloadCandidate(*Best, *Cand, Loc)) { 4310 Best = CandidateSet.end(); 4311 return OR_Ambiguous; 4312 } 4313 } 4314 4315 // Best is the best viable function. 4316 if (Best->Function && 4317 (Best->Function->isDeleted() || 4318 Best->Function->getAttr<UnavailableAttr>())) 4319 return OR_Deleted; 4320 4321 // C++ [basic.def.odr]p2: 4322 // An overloaded function is used if it is selected by overload resolution 4323 // when referred to from a potentially-evaluated expression. [Note: this 4324 // covers calls to named functions (5.2.2), operator overloading 4325 // (clause 13), user-defined conversions (12.3.2), allocation function for 4326 // placement new (5.3.4), as well as non-default initialization (8.5). 4327 if (Best->Function) 4328 MarkDeclarationReferenced(Loc, Best->Function); 4329 return OR_Success; 4330} 4331 4332namespace { 4333 4334enum OverloadCandidateKind { 4335 oc_function, 4336 oc_method, 4337 oc_constructor, 4338 oc_function_template, 4339 oc_method_template, 4340 oc_constructor_template, 4341 oc_implicit_default_constructor, 4342 oc_implicit_copy_constructor, 4343 oc_implicit_copy_assignment 4344}; 4345 4346OverloadCandidateKind ClassifyOverloadCandidate(Sema &S, 4347 FunctionDecl *Fn, 4348 std::string &Description) { 4349 bool isTemplate = false; 4350 4351 if (FunctionTemplateDecl *FunTmpl = Fn->getPrimaryTemplate()) { 4352 isTemplate = true; 4353 Description = S.getTemplateArgumentBindingsText( 4354 FunTmpl->getTemplateParameters(), *Fn->getTemplateSpecializationArgs()); 4355 } 4356 4357 if (CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(Fn)) { 4358 if (!Ctor->isImplicit()) 4359 return isTemplate ? oc_constructor_template : oc_constructor; 4360 4361 return Ctor->isCopyConstructor() ? oc_implicit_copy_constructor 4362 : oc_implicit_default_constructor; 4363 } 4364 4365 if (CXXMethodDecl *Meth = dyn_cast<CXXMethodDecl>(Fn)) { 4366 // This actually gets spelled 'candidate function' for now, but 4367 // it doesn't hurt to split it out. 4368 if (!Meth->isImplicit()) 4369 return isTemplate ? oc_method_template : oc_method; 4370 4371 assert(Meth->isCopyAssignment() 4372 && "implicit method is not copy assignment operator?"); 4373 return oc_implicit_copy_assignment; 4374 } 4375 4376 return isTemplate ? oc_function_template : oc_function; 4377} 4378 4379} // end anonymous namespace 4380 4381// Notes the location of an overload candidate. 4382void Sema::NoteOverloadCandidate(FunctionDecl *Fn) { 4383 std::string FnDesc; 4384 OverloadCandidateKind K = ClassifyOverloadCandidate(*this, Fn, FnDesc); 4385 Diag(Fn->getLocation(), diag::note_ovl_candidate) 4386 << (unsigned) K << FnDesc; 4387} 4388 4389/// Diagnoses an ambiguous conversion. The partial diagnostic is the 4390/// "lead" diagnostic; it will be given two arguments, the source and 4391/// target types of the conversion. 4392void Sema::DiagnoseAmbiguousConversion(const ImplicitConversionSequence &ICS, 4393 SourceLocation CaretLoc, 4394 const PartialDiagnostic &PDiag) { 4395 Diag(CaretLoc, PDiag) 4396 << ICS.Ambiguous.getFromType() << ICS.Ambiguous.getToType(); 4397 for (AmbiguousConversionSequence::const_iterator 4398 I = ICS.Ambiguous.begin(), E = ICS.Ambiguous.end(); I != E; ++I) { 4399 NoteOverloadCandidate(*I); 4400 } 4401} 4402 4403namespace { 4404 4405void DiagnoseBadConversion(Sema &S, OverloadCandidate *Cand, unsigned I) { 4406 const ImplicitConversionSequence &Conv = Cand->Conversions[I]; 4407 assert(Conv.isBad()); 4408 assert(Cand->Function && "for now, candidate must be a function"); 4409 FunctionDecl *Fn = Cand->Function; 4410 4411 // There's a conversion slot for the object argument if this is a 4412 // non-constructor method. Note that 'I' corresponds the 4413 // conversion-slot index. 4414 bool isObjectArgument = false; 4415 if (isa<CXXMethodDecl>(Fn) && !isa<CXXConstructorDecl>(Fn)) { 4416 if (I == 0) 4417 isObjectArgument = true; 4418 else 4419 I--; 4420 } 4421 4422 std::string FnDesc; 4423 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, FnDesc); 4424 4425 Expr *FromExpr = Conv.Bad.FromExpr; 4426 QualType FromTy = Conv.Bad.getFromType(); 4427 QualType ToTy = Conv.Bad.getToType(); 4428 4429 if (FromTy == S.Context.OverloadTy) { 4430 assert(FromExpr && "overload set argument came from implicit argument?"); 4431 Expr *E = FromExpr->IgnoreParens(); 4432 if (isa<UnaryOperator>(E)) 4433 E = cast<UnaryOperator>(E)->getSubExpr()->IgnoreParens(); 4434 DeclarationName Name = cast<OverloadExpr>(E)->getName(); 4435 4436 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_overload) 4437 << (unsigned) FnKind << FnDesc 4438 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 4439 << ToTy << Name << I+1; 4440 return; 4441 } 4442 4443 // Do some hand-waving analysis to see if the non-viability is due 4444 // to a qualifier mismatch. 4445 CanQualType CFromTy = S.Context.getCanonicalType(FromTy); 4446 CanQualType CToTy = S.Context.getCanonicalType(ToTy); 4447 if (CanQual<ReferenceType> RT = CToTy->getAs<ReferenceType>()) 4448 CToTy = RT->getPointeeType(); 4449 else { 4450 // TODO: detect and diagnose the full richness of const mismatches. 4451 if (CanQual<PointerType> FromPT = CFromTy->getAs<PointerType>()) 4452 if (CanQual<PointerType> ToPT = CToTy->getAs<PointerType>()) 4453 CFromTy = FromPT->getPointeeType(), CToTy = ToPT->getPointeeType(); 4454 } 4455 4456 if (CToTy.getUnqualifiedType() == CFromTy.getUnqualifiedType() && 4457 !CToTy.isAtLeastAsQualifiedAs(CFromTy)) { 4458 // It is dumb that we have to do this here. 4459 while (isa<ArrayType>(CFromTy)) 4460 CFromTy = CFromTy->getAs<ArrayType>()->getElementType(); 4461 while (isa<ArrayType>(CToTy)) 4462 CToTy = CFromTy->getAs<ArrayType>()->getElementType(); 4463 4464 Qualifiers FromQs = CFromTy.getQualifiers(); 4465 Qualifiers ToQs = CToTy.getQualifiers(); 4466 4467 if (FromQs.getAddressSpace() != ToQs.getAddressSpace()) { 4468 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_addrspace) 4469 << (unsigned) FnKind << FnDesc 4470 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 4471 << FromTy 4472 << FromQs.getAddressSpace() << ToQs.getAddressSpace() 4473 << (unsigned) isObjectArgument << I+1; 4474 return; 4475 } 4476 4477 unsigned CVR = FromQs.getCVRQualifiers() & ~ToQs.getCVRQualifiers(); 4478 assert(CVR && "unexpected qualifiers mismatch"); 4479 4480 if (isObjectArgument) { 4481 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr_this) 4482 << (unsigned) FnKind << FnDesc 4483 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 4484 << FromTy << (CVR - 1); 4485 } else { 4486 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr) 4487 << (unsigned) FnKind << FnDesc 4488 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 4489 << FromTy << (CVR - 1) << I+1; 4490 } 4491 return; 4492 } 4493 4494 // Diagnose references or pointers to incomplete types differently, 4495 // since it's far from impossible that the incompleteness triggered 4496 // the failure. 4497 QualType TempFromTy = FromTy.getNonReferenceType(); 4498 if (const PointerType *PTy = TempFromTy->getAs<PointerType>()) 4499 TempFromTy = PTy->getPointeeType(); 4500 if (TempFromTy->isIncompleteType()) { 4501 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_conv_incomplete) 4502 << (unsigned) FnKind << FnDesc 4503 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 4504 << FromTy << ToTy << (unsigned) isObjectArgument << I+1; 4505 return; 4506 } 4507 4508 // TODO: specialize more based on the kind of mismatch 4509 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_conv) 4510 << (unsigned) FnKind << FnDesc 4511 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 4512 << FromTy << ToTy << (unsigned) isObjectArgument << I+1; 4513} 4514 4515void DiagnoseArityMismatch(Sema &S, OverloadCandidate *Cand, 4516 unsigned NumFormalArgs) { 4517 // TODO: treat calls to a missing default constructor as a special case 4518 4519 FunctionDecl *Fn = Cand->Function; 4520 const FunctionProtoType *FnTy = Fn->getType()->getAs<FunctionProtoType>(); 4521 4522 unsigned MinParams = Fn->getMinRequiredArguments(); 4523 4524 // at least / at most / exactly 4525 unsigned mode, modeCount; 4526 if (NumFormalArgs < MinParams) { 4527 assert(Cand->FailureKind == ovl_fail_too_few_arguments); 4528 if (MinParams != FnTy->getNumArgs() || FnTy->isVariadic()) 4529 mode = 0; // "at least" 4530 else 4531 mode = 2; // "exactly" 4532 modeCount = MinParams; 4533 } else { 4534 assert(Cand->FailureKind == ovl_fail_too_many_arguments); 4535 if (MinParams != FnTy->getNumArgs()) 4536 mode = 1; // "at most" 4537 else 4538 mode = 2; // "exactly" 4539 modeCount = FnTy->getNumArgs(); 4540 } 4541 4542 std::string Description; 4543 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, Description); 4544 4545 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_arity) 4546 << (unsigned) FnKind << Description << mode << modeCount << NumFormalArgs; 4547} 4548 4549/// Diagnose a failed template-argument deduction. 4550void DiagnoseBadDeduction(Sema &S, OverloadCandidate *Cand, 4551 Expr **Args, unsigned NumArgs) { 4552 FunctionDecl *Fn = Cand->Function; // pattern 4553 4554 TemplateParameter Param = TemplateParameter::getFromOpaqueValue( 4555 Cand->DeductionFailure.TemplateParameter); 4556 4557 switch (Cand->DeductionFailure.Result) { 4558 case Sema::TDK_Success: 4559 llvm_unreachable("TDK_success while diagnosing bad deduction"); 4560 4561 case Sema::TDK_Incomplete: { 4562 NamedDecl *ParamD; 4563 (ParamD = Param.dyn_cast<TemplateTypeParmDecl*>()) || 4564 (ParamD = Param.dyn_cast<NonTypeTemplateParmDecl*>()) || 4565 (ParamD = Param.dyn_cast<TemplateTemplateParmDecl*>()); 4566 assert(ParamD && "no parameter found for incomplete deduction result"); 4567 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_incomplete_deduction) 4568 << ParamD->getDeclName(); 4569 return; 4570 } 4571 4572 // TODO: diagnose these individually, then kill off 4573 // note_ovl_candidate_bad_deduction, which is uselessly vague. 4574 case Sema::TDK_InstantiationDepth: 4575 case Sema::TDK_Inconsistent: 4576 case Sema::TDK_InconsistentQuals: 4577 case Sema::TDK_SubstitutionFailure: 4578 case Sema::TDK_NonDeducedMismatch: 4579 case Sema::TDK_TooManyArguments: 4580 case Sema::TDK_TooFewArguments: 4581 case Sema::TDK_InvalidExplicitArguments: 4582 case Sema::TDK_FailedOverloadResolution: 4583 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_deduction); 4584 return; 4585 } 4586} 4587 4588/// Generates a 'note' diagnostic for an overload candidate. We've 4589/// already generated a primary error at the call site. 4590/// 4591/// It really does need to be a single diagnostic with its caret 4592/// pointed at the candidate declaration. Yes, this creates some 4593/// major challenges of technical writing. Yes, this makes pointing 4594/// out problems with specific arguments quite awkward. It's still 4595/// better than generating twenty screens of text for every failed 4596/// overload. 4597/// 4598/// It would be great to be able to express per-candidate problems 4599/// more richly for those diagnostic clients that cared, but we'd 4600/// still have to be just as careful with the default diagnostics. 4601void NoteFunctionCandidate(Sema &S, OverloadCandidate *Cand, 4602 Expr **Args, unsigned NumArgs) { 4603 FunctionDecl *Fn = Cand->Function; 4604 4605 // Note deleted candidates, but only if they're viable. 4606 if (Cand->Viable && (Fn->isDeleted() || Fn->hasAttr<UnavailableAttr>())) { 4607 std::string FnDesc; 4608 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, FnDesc); 4609 4610 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_deleted) 4611 << FnKind << FnDesc << Fn->isDeleted(); 4612 return; 4613 } 4614 4615 // We don't really have anything else to say about viable candidates. 4616 if (Cand->Viable) { 4617 S.NoteOverloadCandidate(Fn); 4618 return; 4619 } 4620 4621 switch (Cand->FailureKind) { 4622 case ovl_fail_too_many_arguments: 4623 case ovl_fail_too_few_arguments: 4624 return DiagnoseArityMismatch(S, Cand, NumArgs); 4625 4626 case ovl_fail_bad_deduction: 4627 return DiagnoseBadDeduction(S, Cand, Args, NumArgs); 4628 4629 case ovl_fail_trivial_conversion: 4630 case ovl_fail_bad_final_conversion: 4631 return S.NoteOverloadCandidate(Fn); 4632 4633 case ovl_fail_bad_conversion: { 4634 unsigned I = (Cand->IgnoreObjectArgument ? 1 : 0); 4635 for (unsigned N = Cand->Conversions.size(); I != N; ++I) 4636 if (Cand->Conversions[I].isBad()) 4637 return DiagnoseBadConversion(S, Cand, I); 4638 4639 // FIXME: this currently happens when we're called from SemaInit 4640 // when user-conversion overload fails. Figure out how to handle 4641 // those conditions and diagnose them well. 4642 return S.NoteOverloadCandidate(Fn); 4643 } 4644 } 4645} 4646 4647void NoteSurrogateCandidate(Sema &S, OverloadCandidate *Cand) { 4648 // Desugar the type of the surrogate down to a function type, 4649 // retaining as many typedefs as possible while still showing 4650 // the function type (and, therefore, its parameter types). 4651 QualType FnType = Cand->Surrogate->getConversionType(); 4652 bool isLValueReference = false; 4653 bool isRValueReference = false; 4654 bool isPointer = false; 4655 if (const LValueReferenceType *FnTypeRef = 4656 FnType->getAs<LValueReferenceType>()) { 4657 FnType = FnTypeRef->getPointeeType(); 4658 isLValueReference = true; 4659 } else if (const RValueReferenceType *FnTypeRef = 4660 FnType->getAs<RValueReferenceType>()) { 4661 FnType = FnTypeRef->getPointeeType(); 4662 isRValueReference = true; 4663 } 4664 if (const PointerType *FnTypePtr = FnType->getAs<PointerType>()) { 4665 FnType = FnTypePtr->getPointeeType(); 4666 isPointer = true; 4667 } 4668 // Desugar down to a function type. 4669 FnType = QualType(FnType->getAs<FunctionType>(), 0); 4670 // Reconstruct the pointer/reference as appropriate. 4671 if (isPointer) FnType = S.Context.getPointerType(FnType); 4672 if (isRValueReference) FnType = S.Context.getRValueReferenceType(FnType); 4673 if (isLValueReference) FnType = S.Context.getLValueReferenceType(FnType); 4674 4675 S.Diag(Cand->Surrogate->getLocation(), diag::note_ovl_surrogate_cand) 4676 << FnType; 4677} 4678 4679void NoteBuiltinOperatorCandidate(Sema &S, 4680 const char *Opc, 4681 SourceLocation OpLoc, 4682 OverloadCandidate *Cand) { 4683 assert(Cand->Conversions.size() <= 2 && "builtin operator is not binary"); 4684 std::string TypeStr("operator"); 4685 TypeStr += Opc; 4686 TypeStr += "("; 4687 TypeStr += Cand->BuiltinTypes.ParamTypes[0].getAsString(); 4688 if (Cand->Conversions.size() == 1) { 4689 TypeStr += ")"; 4690 S.Diag(OpLoc, diag::note_ovl_builtin_unary_candidate) << TypeStr; 4691 } else { 4692 TypeStr += ", "; 4693 TypeStr += Cand->BuiltinTypes.ParamTypes[1].getAsString(); 4694 TypeStr += ")"; 4695 S.Diag(OpLoc, diag::note_ovl_builtin_binary_candidate) << TypeStr; 4696 } 4697} 4698 4699void NoteAmbiguousUserConversions(Sema &S, SourceLocation OpLoc, 4700 OverloadCandidate *Cand) { 4701 unsigned NoOperands = Cand->Conversions.size(); 4702 for (unsigned ArgIdx = 0; ArgIdx < NoOperands; ++ArgIdx) { 4703 const ImplicitConversionSequence &ICS = Cand->Conversions[ArgIdx]; 4704 if (ICS.isBad()) break; // all meaningless after first invalid 4705 if (!ICS.isAmbiguous()) continue; 4706 4707 S.DiagnoseAmbiguousConversion(ICS, OpLoc, 4708 S.PDiag(diag::note_ambiguous_type_conversion)); 4709 } 4710} 4711 4712SourceLocation GetLocationForCandidate(const OverloadCandidate *Cand) { 4713 if (Cand->Function) 4714 return Cand->Function->getLocation(); 4715 if (Cand->IsSurrogate) 4716 return Cand->Surrogate->getLocation(); 4717 return SourceLocation(); 4718} 4719 4720struct CompareOverloadCandidatesForDisplay { 4721 Sema &S; 4722 CompareOverloadCandidatesForDisplay(Sema &S) : S(S) {} 4723 4724 bool operator()(const OverloadCandidate *L, 4725 const OverloadCandidate *R) { 4726 // Fast-path this check. 4727 if (L == R) return false; 4728 4729 // Order first by viability. 4730 if (L->Viable) { 4731 if (!R->Viable) return true; 4732 4733 // TODO: introduce a tri-valued comparison for overload 4734 // candidates. Would be more worthwhile if we had a sort 4735 // that could exploit it. 4736 if (S.isBetterOverloadCandidate(*L, *R, SourceLocation())) return true; 4737 if (S.isBetterOverloadCandidate(*R, *L, SourceLocation())) return false; 4738 } else if (R->Viable) 4739 return false; 4740 4741 assert(L->Viable == R->Viable); 4742 4743 // Criteria by which we can sort non-viable candidates: 4744 if (!L->Viable) { 4745 // 1. Arity mismatches come after other candidates. 4746 if (L->FailureKind == ovl_fail_too_many_arguments || 4747 L->FailureKind == ovl_fail_too_few_arguments) 4748 return false; 4749 if (R->FailureKind == ovl_fail_too_many_arguments || 4750 R->FailureKind == ovl_fail_too_few_arguments) 4751 return true; 4752 4753 // 2. Bad conversions come first and are ordered by the number 4754 // of bad conversions and quality of good conversions. 4755 if (L->FailureKind == ovl_fail_bad_conversion) { 4756 if (R->FailureKind != ovl_fail_bad_conversion) 4757 return true; 4758 4759 // If there's any ordering between the defined conversions... 4760 // FIXME: this might not be transitive. 4761 assert(L->Conversions.size() == R->Conversions.size()); 4762 4763 int leftBetter = 0; 4764 unsigned I = (L->IgnoreObjectArgument || R->IgnoreObjectArgument); 4765 for (unsigned E = L->Conversions.size(); I != E; ++I) { 4766 switch (S.CompareImplicitConversionSequences(L->Conversions[I], 4767 R->Conversions[I])) { 4768 case ImplicitConversionSequence::Better: 4769 leftBetter++; 4770 break; 4771 4772 case ImplicitConversionSequence::Worse: 4773 leftBetter--; 4774 break; 4775 4776 case ImplicitConversionSequence::Indistinguishable: 4777 break; 4778 } 4779 } 4780 if (leftBetter > 0) return true; 4781 if (leftBetter < 0) return false; 4782 4783 } else if (R->FailureKind == ovl_fail_bad_conversion) 4784 return false; 4785 4786 // TODO: others? 4787 } 4788 4789 // Sort everything else by location. 4790 SourceLocation LLoc = GetLocationForCandidate(L); 4791 SourceLocation RLoc = GetLocationForCandidate(R); 4792 4793 // Put candidates without locations (e.g. builtins) at the end. 4794 if (LLoc.isInvalid()) return false; 4795 if (RLoc.isInvalid()) return true; 4796 4797 return S.SourceMgr.isBeforeInTranslationUnit(LLoc, RLoc); 4798 } 4799}; 4800 4801/// CompleteNonViableCandidate - Normally, overload resolution only 4802/// computes up to the first 4803void CompleteNonViableCandidate(Sema &S, OverloadCandidate *Cand, 4804 Expr **Args, unsigned NumArgs) { 4805 assert(!Cand->Viable); 4806 4807 // Don't do anything on failures other than bad conversion. 4808 if (Cand->FailureKind != ovl_fail_bad_conversion) return; 4809 4810 // Skip forward to the first bad conversion. 4811 unsigned ConvIdx = (Cand->IgnoreObjectArgument ? 1 : 0); 4812 unsigned ConvCount = Cand->Conversions.size(); 4813 while (true) { 4814 assert(ConvIdx != ConvCount && "no bad conversion in candidate"); 4815 ConvIdx++; 4816 if (Cand->Conversions[ConvIdx - 1].isBad()) 4817 break; 4818 } 4819 4820 if (ConvIdx == ConvCount) 4821 return; 4822 4823 assert(!Cand->Conversions[ConvIdx].isInitialized() && 4824 "remaining conversion is initialized?"); 4825 4826 // FIXME: these should probably be preserved from the overload 4827 // operation somehow. 4828 bool SuppressUserConversions = false; 4829 bool ForceRValue = false; 4830 4831 const FunctionProtoType* Proto; 4832 unsigned ArgIdx = ConvIdx; 4833 4834 if (Cand->IsSurrogate) { 4835 QualType ConvType 4836 = Cand->Surrogate->getConversionType().getNonReferenceType(); 4837 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 4838 ConvType = ConvPtrType->getPointeeType(); 4839 Proto = ConvType->getAs<FunctionProtoType>(); 4840 ArgIdx--; 4841 } else if (Cand->Function) { 4842 Proto = Cand->Function->getType()->getAs<FunctionProtoType>(); 4843 if (isa<CXXMethodDecl>(Cand->Function) && 4844 !isa<CXXConstructorDecl>(Cand->Function)) 4845 ArgIdx--; 4846 } else { 4847 // Builtin binary operator with a bad first conversion. 4848 assert(ConvCount <= 3); 4849 for (; ConvIdx != ConvCount; ++ConvIdx) 4850 Cand->Conversions[ConvIdx] 4851 = S.TryCopyInitialization(Args[ConvIdx], 4852 Cand->BuiltinTypes.ParamTypes[ConvIdx], 4853 SuppressUserConversions, ForceRValue, 4854 /*InOverloadResolution*/ true); 4855 return; 4856 } 4857 4858 // Fill in the rest of the conversions. 4859 unsigned NumArgsInProto = Proto->getNumArgs(); 4860 for (; ConvIdx != ConvCount; ++ConvIdx, ++ArgIdx) { 4861 if (ArgIdx < NumArgsInProto) 4862 Cand->Conversions[ConvIdx] 4863 = S.TryCopyInitialization(Args[ArgIdx], Proto->getArgType(ArgIdx), 4864 SuppressUserConversions, ForceRValue, 4865 /*InOverloadResolution=*/true); 4866 else 4867 Cand->Conversions[ConvIdx].setEllipsis(); 4868 } 4869} 4870 4871} // end anonymous namespace 4872 4873/// PrintOverloadCandidates - When overload resolution fails, prints 4874/// diagnostic messages containing the candidates in the candidate 4875/// set. 4876void 4877Sema::PrintOverloadCandidates(OverloadCandidateSet& CandidateSet, 4878 OverloadCandidateDisplayKind OCD, 4879 Expr **Args, unsigned NumArgs, 4880 const char *Opc, 4881 SourceLocation OpLoc) { 4882 // Sort the candidates by viability and position. Sorting directly would 4883 // be prohibitive, so we make a set of pointers and sort those. 4884 llvm::SmallVector<OverloadCandidate*, 32> Cands; 4885 if (OCD == OCD_AllCandidates) Cands.reserve(CandidateSet.size()); 4886 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 4887 LastCand = CandidateSet.end(); 4888 Cand != LastCand; ++Cand) { 4889 if (Cand->Viable) 4890 Cands.push_back(Cand); 4891 else if (OCD == OCD_AllCandidates) { 4892 CompleteNonViableCandidate(*this, Cand, Args, NumArgs); 4893 Cands.push_back(Cand); 4894 } 4895 } 4896 4897 std::sort(Cands.begin(), Cands.end(), 4898 CompareOverloadCandidatesForDisplay(*this)); 4899 4900 bool ReportedAmbiguousConversions = false; 4901 4902 llvm::SmallVectorImpl<OverloadCandidate*>::iterator I, E; 4903 for (I = Cands.begin(), E = Cands.end(); I != E; ++I) { 4904 OverloadCandidate *Cand = *I; 4905 4906 if (Cand->Function) 4907 NoteFunctionCandidate(*this, Cand, Args, NumArgs); 4908 else if (Cand->IsSurrogate) 4909 NoteSurrogateCandidate(*this, Cand); 4910 4911 // This a builtin candidate. We do not, in general, want to list 4912 // every possible builtin candidate. 4913 else if (Cand->Viable) { 4914 // Generally we only see ambiguities including viable builtin 4915 // operators if overload resolution got screwed up by an 4916 // ambiguous user-defined conversion. 4917 // 4918 // FIXME: It's quite possible for different conversions to see 4919 // different ambiguities, though. 4920 if (!ReportedAmbiguousConversions) { 4921 NoteAmbiguousUserConversions(*this, OpLoc, Cand); 4922 ReportedAmbiguousConversions = true; 4923 } 4924 4925 // If this is a viable builtin, print it. 4926 NoteBuiltinOperatorCandidate(*this, Opc, OpLoc, Cand); 4927 } 4928 } 4929} 4930 4931static bool CheckUnresolvedAccess(Sema &S, OverloadExpr *E, DeclAccessPair D) { 4932 if (isa<UnresolvedLookupExpr>(E)) 4933 return S.CheckUnresolvedLookupAccess(cast<UnresolvedLookupExpr>(E), D); 4934 4935 return S.CheckUnresolvedMemberAccess(cast<UnresolvedMemberExpr>(E), D); 4936} 4937 4938/// ResolveAddressOfOverloadedFunction - Try to resolve the address of 4939/// an overloaded function (C++ [over.over]), where @p From is an 4940/// expression with overloaded function type and @p ToType is the type 4941/// we're trying to resolve to. For example: 4942/// 4943/// @code 4944/// int f(double); 4945/// int f(int); 4946/// 4947/// int (*pfd)(double) = f; // selects f(double) 4948/// @endcode 4949/// 4950/// This routine returns the resulting FunctionDecl if it could be 4951/// resolved, and NULL otherwise. When @p Complain is true, this 4952/// routine will emit diagnostics if there is an error. 4953FunctionDecl * 4954Sema::ResolveAddressOfOverloadedFunction(Expr *From, QualType ToType, 4955 bool Complain, 4956 DeclAccessPair &FoundResult) { 4957 QualType FunctionType = ToType; 4958 bool IsMember = false; 4959 if (const PointerType *ToTypePtr = ToType->getAs<PointerType>()) 4960 FunctionType = ToTypePtr->getPointeeType(); 4961 else if (const ReferenceType *ToTypeRef = ToType->getAs<ReferenceType>()) 4962 FunctionType = ToTypeRef->getPointeeType(); 4963 else if (const MemberPointerType *MemTypePtr = 4964 ToType->getAs<MemberPointerType>()) { 4965 FunctionType = MemTypePtr->getPointeeType(); 4966 IsMember = true; 4967 } 4968 4969 // We only look at pointers or references to functions. 4970 FunctionType = Context.getCanonicalType(FunctionType).getUnqualifiedType(); 4971 if (!FunctionType->isFunctionType()) 4972 return 0; 4973 4974 // Find the actual overloaded function declaration. 4975 if (From->getType() != Context.OverloadTy) 4976 return 0; 4977 4978 // C++ [over.over]p1: 4979 // [...] [Note: any redundant set of parentheses surrounding the 4980 // overloaded function name is ignored (5.1). ] 4981 // C++ [over.over]p1: 4982 // [...] The overloaded function name can be preceded by the & 4983 // operator. 4984 OverloadExpr *OvlExpr = OverloadExpr::find(From).getPointer(); 4985 TemplateArgumentListInfo ETABuffer, *ExplicitTemplateArgs = 0; 4986 if (OvlExpr->hasExplicitTemplateArgs()) { 4987 OvlExpr->getExplicitTemplateArgs().copyInto(ETABuffer); 4988 ExplicitTemplateArgs = &ETABuffer; 4989 } 4990 4991 // Look through all of the overloaded functions, searching for one 4992 // whose type matches exactly. 4993 llvm::SmallVector<std::pair<DeclAccessPair, FunctionDecl*>, 4> Matches; 4994 llvm::SmallVector<FunctionDecl *, 4> NonMatches; 4995 4996 bool FoundNonTemplateFunction = false; 4997 for (UnresolvedSetIterator I = OvlExpr->decls_begin(), 4998 E = OvlExpr->decls_end(); I != E; ++I) { 4999 // Look through any using declarations to find the underlying function. 5000 NamedDecl *Fn = (*I)->getUnderlyingDecl(); 5001 5002 // C++ [over.over]p3: 5003 // Non-member functions and static member functions match 5004 // targets of type "pointer-to-function" or "reference-to-function." 5005 // Nonstatic member functions match targets of 5006 // type "pointer-to-member-function." 5007 // Note that according to DR 247, the containing class does not matter. 5008 5009 if (FunctionTemplateDecl *FunctionTemplate 5010 = dyn_cast<FunctionTemplateDecl>(Fn)) { 5011 if (CXXMethodDecl *Method 5012 = dyn_cast<CXXMethodDecl>(FunctionTemplate->getTemplatedDecl())) { 5013 // Skip non-static function templates when converting to pointer, and 5014 // static when converting to member pointer. 5015 if (Method->isStatic() == IsMember) 5016 continue; 5017 } else if (IsMember) 5018 continue; 5019 5020 // C++ [over.over]p2: 5021 // If the name is a function template, template argument deduction is 5022 // done (14.8.2.2), and if the argument deduction succeeds, the 5023 // resulting template argument list is used to generate a single 5024 // function template specialization, which is added to the set of 5025 // overloaded functions considered. 5026 // FIXME: We don't really want to build the specialization here, do we? 5027 FunctionDecl *Specialization = 0; 5028 TemplateDeductionInfo Info(Context, OvlExpr->getNameLoc()); 5029 if (TemplateDeductionResult Result 5030 = DeduceTemplateArguments(FunctionTemplate, ExplicitTemplateArgs, 5031 FunctionType, Specialization, Info)) { 5032 // FIXME: make a note of the failed deduction for diagnostics. 5033 (void)Result; 5034 } else { 5035 // FIXME: If the match isn't exact, shouldn't we just drop this as 5036 // a candidate? Find a testcase before changing the code. 5037 assert(FunctionType 5038 == Context.getCanonicalType(Specialization->getType())); 5039 Matches.push_back(std::make_pair(I.getPair(), 5040 cast<FunctionDecl>(Specialization->getCanonicalDecl()))); 5041 } 5042 5043 continue; 5044 } 5045 5046 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 5047 // Skip non-static functions when converting to pointer, and static 5048 // when converting to member pointer. 5049 if (Method->isStatic() == IsMember) 5050 continue; 5051 5052 // If we have explicit template arguments, skip non-templates. 5053 if (OvlExpr->hasExplicitTemplateArgs()) 5054 continue; 5055 } else if (IsMember) 5056 continue; 5057 5058 if (FunctionDecl *FunDecl = dyn_cast<FunctionDecl>(Fn)) { 5059 QualType ResultTy; 5060 if (Context.hasSameUnqualifiedType(FunctionType, FunDecl->getType()) || 5061 IsNoReturnConversion(Context, FunDecl->getType(), FunctionType, 5062 ResultTy)) { 5063 Matches.push_back(std::make_pair(I.getPair(), 5064 cast<FunctionDecl>(FunDecl->getCanonicalDecl()))); 5065 FoundNonTemplateFunction = true; 5066 } 5067 } 5068 } 5069 5070 // If there were 0 or 1 matches, we're done. 5071 if (Matches.empty()) 5072 return 0; 5073 else if (Matches.size() == 1) { 5074 FunctionDecl *Result = Matches[0].second; 5075 FoundResult = Matches[0].first; 5076 MarkDeclarationReferenced(From->getLocStart(), Result); 5077 if (Complain) 5078 CheckAddressOfMemberAccess(OvlExpr, Matches[0].first); 5079 return Result; 5080 } 5081 5082 // C++ [over.over]p4: 5083 // If more than one function is selected, [...] 5084 if (!FoundNonTemplateFunction) { 5085 // [...] and any given function template specialization F1 is 5086 // eliminated if the set contains a second function template 5087 // specialization whose function template is more specialized 5088 // than the function template of F1 according to the partial 5089 // ordering rules of 14.5.5.2. 5090 5091 // The algorithm specified above is quadratic. We instead use a 5092 // two-pass algorithm (similar to the one used to identify the 5093 // best viable function in an overload set) that identifies the 5094 // best function template (if it exists). 5095 5096 UnresolvedSet<4> MatchesCopy; // TODO: avoid! 5097 for (unsigned I = 0, E = Matches.size(); I != E; ++I) 5098 MatchesCopy.addDecl(Matches[I].second, Matches[I].first.getAccess()); 5099 5100 UnresolvedSetIterator Result = 5101 getMostSpecialized(MatchesCopy.begin(), MatchesCopy.end(), 5102 TPOC_Other, From->getLocStart(), 5103 PDiag(), 5104 PDiag(diag::err_addr_ovl_ambiguous) 5105 << Matches[0].second->getDeclName(), 5106 PDiag(diag::note_ovl_candidate) 5107 << (unsigned) oc_function_template); 5108 assert(Result != MatchesCopy.end() && "no most-specialized template"); 5109 MarkDeclarationReferenced(From->getLocStart(), *Result); 5110 FoundResult = Matches[Result - MatchesCopy.begin()].first; 5111 if (Complain) 5112 CheckUnresolvedAccess(*this, OvlExpr, FoundResult); 5113 return cast<FunctionDecl>(*Result); 5114 } 5115 5116 // [...] any function template specializations in the set are 5117 // eliminated if the set also contains a non-template function, [...] 5118 for (unsigned I = 0, N = Matches.size(); I != N; ) { 5119 if (Matches[I].second->getPrimaryTemplate() == 0) 5120 ++I; 5121 else { 5122 Matches[I] = Matches[--N]; 5123 Matches.set_size(N); 5124 } 5125 } 5126 5127 // [...] After such eliminations, if any, there shall remain exactly one 5128 // selected function. 5129 if (Matches.size() == 1) { 5130 MarkDeclarationReferenced(From->getLocStart(), Matches[0].second); 5131 FoundResult = Matches[0].first; 5132 if (Complain) 5133 CheckUnresolvedAccess(*this, OvlExpr, Matches[0].first); 5134 return cast<FunctionDecl>(Matches[0].second); 5135 } 5136 5137 // FIXME: We should probably return the same thing that BestViableFunction 5138 // returns (even if we issue the diagnostics here). 5139 Diag(From->getLocStart(), diag::err_addr_ovl_ambiguous) 5140 << Matches[0].second->getDeclName(); 5141 for (unsigned I = 0, E = Matches.size(); I != E; ++I) 5142 NoteOverloadCandidate(Matches[I].second); 5143 return 0; 5144} 5145 5146/// \brief Given an expression that refers to an overloaded function, try to 5147/// resolve that overloaded function expression down to a single function. 5148/// 5149/// This routine can only resolve template-ids that refer to a single function 5150/// template, where that template-id refers to a single template whose template 5151/// arguments are either provided by the template-id or have defaults, 5152/// as described in C++0x [temp.arg.explicit]p3. 5153FunctionDecl *Sema::ResolveSingleFunctionTemplateSpecialization(Expr *From) { 5154 // C++ [over.over]p1: 5155 // [...] [Note: any redundant set of parentheses surrounding the 5156 // overloaded function name is ignored (5.1). ] 5157 // C++ [over.over]p1: 5158 // [...] The overloaded function name can be preceded by the & 5159 // operator. 5160 5161 if (From->getType() != Context.OverloadTy) 5162 return 0; 5163 5164 OverloadExpr *OvlExpr = OverloadExpr::find(From).getPointer(); 5165 5166 // If we didn't actually find any template-ids, we're done. 5167 if (!OvlExpr->hasExplicitTemplateArgs()) 5168 return 0; 5169 5170 TemplateArgumentListInfo ExplicitTemplateArgs; 5171 OvlExpr->getExplicitTemplateArgs().copyInto(ExplicitTemplateArgs); 5172 5173 // Look through all of the overloaded functions, searching for one 5174 // whose type matches exactly. 5175 FunctionDecl *Matched = 0; 5176 for (UnresolvedSetIterator I = OvlExpr->decls_begin(), 5177 E = OvlExpr->decls_end(); I != E; ++I) { 5178 // C++0x [temp.arg.explicit]p3: 5179 // [...] In contexts where deduction is done and fails, or in contexts 5180 // where deduction is not done, if a template argument list is 5181 // specified and it, along with any default template arguments, 5182 // identifies a single function template specialization, then the 5183 // template-id is an lvalue for the function template specialization. 5184 FunctionTemplateDecl *FunctionTemplate = cast<FunctionTemplateDecl>(*I); 5185 5186 // C++ [over.over]p2: 5187 // If the name is a function template, template argument deduction is 5188 // done (14.8.2.2), and if the argument deduction succeeds, the 5189 // resulting template argument list is used to generate a single 5190 // function template specialization, which is added to the set of 5191 // overloaded functions considered. 5192 FunctionDecl *Specialization = 0; 5193 TemplateDeductionInfo Info(Context, OvlExpr->getNameLoc()); 5194 if (TemplateDeductionResult Result 5195 = DeduceTemplateArguments(FunctionTemplate, &ExplicitTemplateArgs, 5196 Specialization, Info)) { 5197 // FIXME: make a note of the failed deduction for diagnostics. 5198 (void)Result; 5199 continue; 5200 } 5201 5202 // Multiple matches; we can't resolve to a single declaration. 5203 if (Matched) 5204 return 0; 5205 5206 Matched = Specialization; 5207 } 5208 5209 return Matched; 5210} 5211 5212/// \brief Add a single candidate to the overload set. 5213static void AddOverloadedCallCandidate(Sema &S, 5214 DeclAccessPair FoundDecl, 5215 const TemplateArgumentListInfo *ExplicitTemplateArgs, 5216 Expr **Args, unsigned NumArgs, 5217 OverloadCandidateSet &CandidateSet, 5218 bool PartialOverloading) { 5219 NamedDecl *Callee = FoundDecl.getDecl(); 5220 if (isa<UsingShadowDecl>(Callee)) 5221 Callee = cast<UsingShadowDecl>(Callee)->getTargetDecl(); 5222 5223 if (FunctionDecl *Func = dyn_cast<FunctionDecl>(Callee)) { 5224 assert(!ExplicitTemplateArgs && "Explicit template arguments?"); 5225 S.AddOverloadCandidate(Func, FoundDecl, Args, NumArgs, CandidateSet, 5226 false, false, PartialOverloading); 5227 return; 5228 } 5229 5230 if (FunctionTemplateDecl *FuncTemplate 5231 = dyn_cast<FunctionTemplateDecl>(Callee)) { 5232 S.AddTemplateOverloadCandidate(FuncTemplate, FoundDecl, 5233 ExplicitTemplateArgs, 5234 Args, NumArgs, CandidateSet); 5235 return; 5236 } 5237 5238 assert(false && "unhandled case in overloaded call candidate"); 5239 5240 // do nothing? 5241} 5242 5243/// \brief Add the overload candidates named by callee and/or found by argument 5244/// dependent lookup to the given overload set. 5245void Sema::AddOverloadedCallCandidates(UnresolvedLookupExpr *ULE, 5246 Expr **Args, unsigned NumArgs, 5247 OverloadCandidateSet &CandidateSet, 5248 bool PartialOverloading) { 5249 5250#ifndef NDEBUG 5251 // Verify that ArgumentDependentLookup is consistent with the rules 5252 // in C++0x [basic.lookup.argdep]p3: 5253 // 5254 // Let X be the lookup set produced by unqualified lookup (3.4.1) 5255 // and let Y be the lookup set produced by argument dependent 5256 // lookup (defined as follows). If X contains 5257 // 5258 // -- a declaration of a class member, or 5259 // 5260 // -- a block-scope function declaration that is not a 5261 // using-declaration, or 5262 // 5263 // -- a declaration that is neither a function or a function 5264 // template 5265 // 5266 // then Y is empty. 5267 5268 if (ULE->requiresADL()) { 5269 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(), 5270 E = ULE->decls_end(); I != E; ++I) { 5271 assert(!(*I)->getDeclContext()->isRecord()); 5272 assert(isa<UsingShadowDecl>(*I) || 5273 !(*I)->getDeclContext()->isFunctionOrMethod()); 5274 assert((*I)->getUnderlyingDecl()->isFunctionOrFunctionTemplate()); 5275 } 5276 } 5277#endif 5278 5279 // It would be nice to avoid this copy. 5280 TemplateArgumentListInfo TABuffer; 5281 const TemplateArgumentListInfo *ExplicitTemplateArgs = 0; 5282 if (ULE->hasExplicitTemplateArgs()) { 5283 ULE->copyTemplateArgumentsInto(TABuffer); 5284 ExplicitTemplateArgs = &TABuffer; 5285 } 5286 5287 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(), 5288 E = ULE->decls_end(); I != E; ++I) 5289 AddOverloadedCallCandidate(*this, I.getPair(), ExplicitTemplateArgs, 5290 Args, NumArgs, CandidateSet, 5291 PartialOverloading); 5292 5293 if (ULE->requiresADL()) 5294 AddArgumentDependentLookupCandidates(ULE->getName(), /*Operator*/ false, 5295 Args, NumArgs, 5296 ExplicitTemplateArgs, 5297 CandidateSet, 5298 PartialOverloading); 5299} 5300 5301static Sema::OwningExprResult Destroy(Sema &SemaRef, Expr *Fn, 5302 Expr **Args, unsigned NumArgs) { 5303 Fn->Destroy(SemaRef.Context); 5304 for (unsigned Arg = 0; Arg < NumArgs; ++Arg) 5305 Args[Arg]->Destroy(SemaRef.Context); 5306 return SemaRef.ExprError(); 5307} 5308 5309/// Attempts to recover from a call where no functions were found. 5310/// 5311/// Returns true if new candidates were found. 5312static Sema::OwningExprResult 5313BuildRecoveryCallExpr(Sema &SemaRef, Expr *Fn, 5314 UnresolvedLookupExpr *ULE, 5315 SourceLocation LParenLoc, 5316 Expr **Args, unsigned NumArgs, 5317 SourceLocation *CommaLocs, 5318 SourceLocation RParenLoc) { 5319 5320 CXXScopeSpec SS; 5321 if (ULE->getQualifier()) { 5322 SS.setScopeRep(ULE->getQualifier()); 5323 SS.setRange(ULE->getQualifierRange()); 5324 } 5325 5326 TemplateArgumentListInfo TABuffer; 5327 const TemplateArgumentListInfo *ExplicitTemplateArgs = 0; 5328 if (ULE->hasExplicitTemplateArgs()) { 5329 ULE->copyTemplateArgumentsInto(TABuffer); 5330 ExplicitTemplateArgs = &TABuffer; 5331 } 5332 5333 LookupResult R(SemaRef, ULE->getName(), ULE->getNameLoc(), 5334 Sema::LookupOrdinaryName); 5335 if (SemaRef.DiagnoseEmptyLookup(/*Scope=*/0, SS, R)) 5336 return Destroy(SemaRef, Fn, Args, NumArgs); 5337 5338 assert(!R.empty() && "lookup results empty despite recovery"); 5339 5340 // Build an implicit member call if appropriate. Just drop the 5341 // casts and such from the call, we don't really care. 5342 Sema::OwningExprResult NewFn = SemaRef.ExprError(); 5343 if ((*R.begin())->isCXXClassMember()) 5344 NewFn = SemaRef.BuildPossibleImplicitMemberExpr(SS, R, ExplicitTemplateArgs); 5345 else if (ExplicitTemplateArgs) 5346 NewFn = SemaRef.BuildTemplateIdExpr(SS, R, false, *ExplicitTemplateArgs); 5347 else 5348 NewFn = SemaRef.BuildDeclarationNameExpr(SS, R, false); 5349 5350 if (NewFn.isInvalid()) 5351 return Destroy(SemaRef, Fn, Args, NumArgs); 5352 5353 Fn->Destroy(SemaRef.Context); 5354 5355 // This shouldn't cause an infinite loop because we're giving it 5356 // an expression with non-empty lookup results, which should never 5357 // end up here. 5358 return SemaRef.ActOnCallExpr(/*Scope*/ 0, move(NewFn), LParenLoc, 5359 Sema::MultiExprArg(SemaRef, (void**) Args, NumArgs), 5360 CommaLocs, RParenLoc); 5361} 5362 5363/// ResolveOverloadedCallFn - Given the call expression that calls Fn 5364/// (which eventually refers to the declaration Func) and the call 5365/// arguments Args/NumArgs, attempt to resolve the function call down 5366/// to a specific function. If overload resolution succeeds, returns 5367/// the function declaration produced by overload 5368/// resolution. Otherwise, emits diagnostics, deletes all of the 5369/// arguments and Fn, and returns NULL. 5370Sema::OwningExprResult 5371Sema::BuildOverloadedCallExpr(Expr *Fn, UnresolvedLookupExpr *ULE, 5372 SourceLocation LParenLoc, 5373 Expr **Args, unsigned NumArgs, 5374 SourceLocation *CommaLocs, 5375 SourceLocation RParenLoc) { 5376#ifndef NDEBUG 5377 if (ULE->requiresADL()) { 5378 // To do ADL, we must have found an unqualified name. 5379 assert(!ULE->getQualifier() && "qualified name with ADL"); 5380 5381 // We don't perform ADL for implicit declarations of builtins. 5382 // Verify that this was correctly set up. 5383 FunctionDecl *F; 5384 if (ULE->decls_begin() + 1 == ULE->decls_end() && 5385 (F = dyn_cast<FunctionDecl>(*ULE->decls_begin())) && 5386 F->getBuiltinID() && F->isImplicit()) 5387 assert(0 && "performing ADL for builtin"); 5388 5389 // We don't perform ADL in C. 5390 assert(getLangOptions().CPlusPlus && "ADL enabled in C"); 5391 } 5392#endif 5393 5394 OverloadCandidateSet CandidateSet(Fn->getExprLoc()); 5395 5396 // Add the functions denoted by the callee to the set of candidate 5397 // functions, including those from argument-dependent lookup. 5398 AddOverloadedCallCandidates(ULE, Args, NumArgs, CandidateSet); 5399 5400 // If we found nothing, try to recover. 5401 // AddRecoveryCallCandidates diagnoses the error itself, so we just 5402 // bailout out if it fails. 5403 if (CandidateSet.empty()) 5404 return BuildRecoveryCallExpr(*this, Fn, ULE, LParenLoc, Args, NumArgs, 5405 CommaLocs, RParenLoc); 5406 5407 OverloadCandidateSet::iterator Best; 5408 switch (BestViableFunction(CandidateSet, Fn->getLocStart(), Best)) { 5409 case OR_Success: { 5410 FunctionDecl *FDecl = Best->Function; 5411 CheckUnresolvedLookupAccess(ULE, Best->FoundDecl); 5412 Fn = FixOverloadedFunctionReference(Fn, Best->FoundDecl, FDecl); 5413 return BuildResolvedCallExpr(Fn, FDecl, LParenLoc, Args, NumArgs, RParenLoc); 5414 } 5415 5416 case OR_No_Viable_Function: 5417 Diag(Fn->getSourceRange().getBegin(), 5418 diag::err_ovl_no_viable_function_in_call) 5419 << ULE->getName() << Fn->getSourceRange(); 5420 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 5421 break; 5422 5423 case OR_Ambiguous: 5424 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_ambiguous_call) 5425 << ULE->getName() << Fn->getSourceRange(); 5426 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, NumArgs); 5427 break; 5428 5429 case OR_Deleted: 5430 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_deleted_call) 5431 << Best->Function->isDeleted() 5432 << ULE->getName() 5433 << Fn->getSourceRange(); 5434 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 5435 break; 5436 } 5437 5438 // Overload resolution failed. Destroy all of the subexpressions and 5439 // return NULL. 5440 Fn->Destroy(Context); 5441 for (unsigned Arg = 0; Arg < NumArgs; ++Arg) 5442 Args[Arg]->Destroy(Context); 5443 return ExprError(); 5444} 5445 5446static bool IsOverloaded(const UnresolvedSetImpl &Functions) { 5447 return Functions.size() > 1 || 5448 (Functions.size() == 1 && isa<FunctionTemplateDecl>(*Functions.begin())); 5449} 5450 5451/// \brief Create a unary operation that may resolve to an overloaded 5452/// operator. 5453/// 5454/// \param OpLoc The location of the operator itself (e.g., '*'). 5455/// 5456/// \param OpcIn The UnaryOperator::Opcode that describes this 5457/// operator. 5458/// 5459/// \param Functions The set of non-member functions that will be 5460/// considered by overload resolution. The caller needs to build this 5461/// set based on the context using, e.g., 5462/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 5463/// set should not contain any member functions; those will be added 5464/// by CreateOverloadedUnaryOp(). 5465/// 5466/// \param input The input argument. 5467Sema::OwningExprResult 5468Sema::CreateOverloadedUnaryOp(SourceLocation OpLoc, unsigned OpcIn, 5469 const UnresolvedSetImpl &Fns, 5470 ExprArg input) { 5471 UnaryOperator::Opcode Opc = static_cast<UnaryOperator::Opcode>(OpcIn); 5472 Expr *Input = (Expr *)input.get(); 5473 5474 OverloadedOperatorKind Op = UnaryOperator::getOverloadedOperator(Opc); 5475 assert(Op != OO_None && "Invalid opcode for overloaded unary operator"); 5476 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 5477 5478 Expr *Args[2] = { Input, 0 }; 5479 unsigned NumArgs = 1; 5480 5481 // For post-increment and post-decrement, add the implicit '0' as 5482 // the second argument, so that we know this is a post-increment or 5483 // post-decrement. 5484 if (Opc == UnaryOperator::PostInc || Opc == UnaryOperator::PostDec) { 5485 llvm::APSInt Zero(Context.getTypeSize(Context.IntTy), false); 5486 Args[1] = new (Context) IntegerLiteral(Zero, Context.IntTy, 5487 SourceLocation()); 5488 NumArgs = 2; 5489 } 5490 5491 if (Input->isTypeDependent()) { 5492 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 5493 UnresolvedLookupExpr *Fn 5494 = UnresolvedLookupExpr::Create(Context, /*Dependent*/ true, NamingClass, 5495 0, SourceRange(), OpName, OpLoc, 5496 /*ADL*/ true, IsOverloaded(Fns)); 5497 Fn->addDecls(Fns.begin(), Fns.end()); 5498 5499 input.release(); 5500 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 5501 &Args[0], NumArgs, 5502 Context.DependentTy, 5503 OpLoc)); 5504 } 5505 5506 // Build an empty overload set. 5507 OverloadCandidateSet CandidateSet(OpLoc); 5508 5509 // Add the candidates from the given function set. 5510 AddFunctionCandidates(Fns, &Args[0], NumArgs, CandidateSet, false); 5511 5512 // Add operator candidates that are member functions. 5513 AddMemberOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 5514 5515 // Add candidates from ADL. 5516 AddArgumentDependentLookupCandidates(OpName, /*Operator*/ true, 5517 Args, NumArgs, 5518 /*ExplicitTemplateArgs*/ 0, 5519 CandidateSet); 5520 5521 // Add builtin operator candidates. 5522 AddBuiltinOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 5523 5524 // Perform overload resolution. 5525 OverloadCandidateSet::iterator Best; 5526 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 5527 case OR_Success: { 5528 // We found a built-in operator or an overloaded operator. 5529 FunctionDecl *FnDecl = Best->Function; 5530 5531 if (FnDecl) { 5532 // We matched an overloaded operator. Build a call to that 5533 // operator. 5534 5535 // Convert the arguments. 5536 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 5537 CheckMemberOperatorAccess(OpLoc, Args[0], 0, Best->FoundDecl); 5538 5539 if (PerformObjectArgumentInitialization(Input, /*Qualifier=*/0, 5540 Best->FoundDecl, Method)) 5541 return ExprError(); 5542 } else { 5543 // Convert the arguments. 5544 OwningExprResult InputInit 5545 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 5546 FnDecl->getParamDecl(0)), 5547 SourceLocation(), 5548 move(input)); 5549 if (InputInit.isInvalid()) 5550 return ExprError(); 5551 5552 input = move(InputInit); 5553 Input = (Expr *)input.get(); 5554 } 5555 5556 // Determine the result type 5557 QualType ResultTy = FnDecl->getResultType().getNonReferenceType(); 5558 5559 // Build the actual expression node. 5560 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 5561 SourceLocation()); 5562 UsualUnaryConversions(FnExpr); 5563 5564 input.release(); 5565 Args[0] = Input; 5566 ExprOwningPtr<CallExpr> TheCall(this, 5567 new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 5568 Args, NumArgs, ResultTy, OpLoc)); 5569 5570 if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall.get(), 5571 FnDecl)) 5572 return ExprError(); 5573 5574 return MaybeBindToTemporary(TheCall.release()); 5575 } else { 5576 // We matched a built-in operator. Convert the arguments, then 5577 // break out so that we will build the appropriate built-in 5578 // operator node. 5579 if (PerformImplicitConversion(Input, Best->BuiltinTypes.ParamTypes[0], 5580 Best->Conversions[0], AA_Passing)) 5581 return ExprError(); 5582 5583 break; 5584 } 5585 } 5586 5587 case OR_No_Viable_Function: 5588 // No viable function; fall through to handling this as a 5589 // built-in operator, which will produce an error message for us. 5590 break; 5591 5592 case OR_Ambiguous: 5593 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 5594 << UnaryOperator::getOpcodeStr(Opc) 5595 << Input->getSourceRange(); 5596 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, NumArgs, 5597 UnaryOperator::getOpcodeStr(Opc), OpLoc); 5598 return ExprError(); 5599 5600 case OR_Deleted: 5601 Diag(OpLoc, diag::err_ovl_deleted_oper) 5602 << Best->Function->isDeleted() 5603 << UnaryOperator::getOpcodeStr(Opc) 5604 << Input->getSourceRange(); 5605 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 5606 return ExprError(); 5607 } 5608 5609 // Either we found no viable overloaded operator or we matched a 5610 // built-in operator. In either case, fall through to trying to 5611 // build a built-in operation. 5612 input.release(); 5613 return CreateBuiltinUnaryOp(OpLoc, Opc, Owned(Input)); 5614} 5615 5616/// \brief Create a binary operation that may resolve to an overloaded 5617/// operator. 5618/// 5619/// \param OpLoc The location of the operator itself (e.g., '+'). 5620/// 5621/// \param OpcIn The BinaryOperator::Opcode that describes this 5622/// operator. 5623/// 5624/// \param Functions The set of non-member functions that will be 5625/// considered by overload resolution. The caller needs to build this 5626/// set based on the context using, e.g., 5627/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 5628/// set should not contain any member functions; those will be added 5629/// by CreateOverloadedBinOp(). 5630/// 5631/// \param LHS Left-hand argument. 5632/// \param RHS Right-hand argument. 5633Sema::OwningExprResult 5634Sema::CreateOverloadedBinOp(SourceLocation OpLoc, 5635 unsigned OpcIn, 5636 const UnresolvedSetImpl &Fns, 5637 Expr *LHS, Expr *RHS) { 5638 Expr *Args[2] = { LHS, RHS }; 5639 LHS=RHS=0; //Please use only Args instead of LHS/RHS couple 5640 5641 BinaryOperator::Opcode Opc = static_cast<BinaryOperator::Opcode>(OpcIn); 5642 OverloadedOperatorKind Op = BinaryOperator::getOverloadedOperator(Opc); 5643 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 5644 5645 // If either side is type-dependent, create an appropriate dependent 5646 // expression. 5647 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 5648 if (Fns.empty()) { 5649 // If there are no functions to store, just build a dependent 5650 // BinaryOperator or CompoundAssignment. 5651 if (Opc <= BinaryOperator::Assign || Opc > BinaryOperator::OrAssign) 5652 return Owned(new (Context) BinaryOperator(Args[0], Args[1], Opc, 5653 Context.DependentTy, OpLoc)); 5654 5655 return Owned(new (Context) CompoundAssignOperator(Args[0], Args[1], Opc, 5656 Context.DependentTy, 5657 Context.DependentTy, 5658 Context.DependentTy, 5659 OpLoc)); 5660 } 5661 5662 // FIXME: save results of ADL from here? 5663 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 5664 UnresolvedLookupExpr *Fn 5665 = UnresolvedLookupExpr::Create(Context, /*Dependent*/ true, NamingClass, 5666 0, SourceRange(), OpName, OpLoc, 5667 /*ADL*/ true, IsOverloaded(Fns)); 5668 5669 Fn->addDecls(Fns.begin(), Fns.end()); 5670 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 5671 Args, 2, 5672 Context.DependentTy, 5673 OpLoc)); 5674 } 5675 5676 // If this is the .* operator, which is not overloadable, just 5677 // create a built-in binary operator. 5678 if (Opc == BinaryOperator::PtrMemD) 5679 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 5680 5681 // If this is the assignment operator, we only perform overload resolution 5682 // if the left-hand side is a class or enumeration type. This is actually 5683 // a hack. The standard requires that we do overload resolution between the 5684 // various built-in candidates, but as DR507 points out, this can lead to 5685 // problems. So we do it this way, which pretty much follows what GCC does. 5686 // Note that we go the traditional code path for compound assignment forms. 5687 if (Opc==BinaryOperator::Assign && !Args[0]->getType()->isOverloadableType()) 5688 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 5689 5690 // Build an empty overload set. 5691 OverloadCandidateSet CandidateSet(OpLoc); 5692 5693 // Add the candidates from the given function set. 5694 AddFunctionCandidates(Fns, Args, 2, CandidateSet, false); 5695 5696 // Add operator candidates that are member functions. 5697 AddMemberOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 5698 5699 // Add candidates from ADL. 5700 AddArgumentDependentLookupCandidates(OpName, /*Operator*/ true, 5701 Args, 2, 5702 /*ExplicitTemplateArgs*/ 0, 5703 CandidateSet); 5704 5705 // Add builtin operator candidates. 5706 AddBuiltinOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 5707 5708 // Perform overload resolution. 5709 OverloadCandidateSet::iterator Best; 5710 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 5711 case OR_Success: { 5712 // We found a built-in operator or an overloaded operator. 5713 FunctionDecl *FnDecl = Best->Function; 5714 5715 if (FnDecl) { 5716 // We matched an overloaded operator. Build a call to that 5717 // operator. 5718 5719 // Convert the arguments. 5720 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 5721 // Best->Access is only meaningful for class members. 5722 CheckMemberOperatorAccess(OpLoc, Args[0], Args[1], Best->FoundDecl); 5723 5724 OwningExprResult Arg1 5725 = PerformCopyInitialization( 5726 InitializedEntity::InitializeParameter( 5727 FnDecl->getParamDecl(0)), 5728 SourceLocation(), 5729 Owned(Args[1])); 5730 if (Arg1.isInvalid()) 5731 return ExprError(); 5732 5733 if (PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/0, 5734 Best->FoundDecl, Method)) 5735 return ExprError(); 5736 5737 Args[1] = RHS = Arg1.takeAs<Expr>(); 5738 } else { 5739 // Convert the arguments. 5740 OwningExprResult Arg0 5741 = PerformCopyInitialization( 5742 InitializedEntity::InitializeParameter( 5743 FnDecl->getParamDecl(0)), 5744 SourceLocation(), 5745 Owned(Args[0])); 5746 if (Arg0.isInvalid()) 5747 return ExprError(); 5748 5749 OwningExprResult Arg1 5750 = PerformCopyInitialization( 5751 InitializedEntity::InitializeParameter( 5752 FnDecl->getParamDecl(1)), 5753 SourceLocation(), 5754 Owned(Args[1])); 5755 if (Arg1.isInvalid()) 5756 return ExprError(); 5757 Args[0] = LHS = Arg0.takeAs<Expr>(); 5758 Args[1] = RHS = Arg1.takeAs<Expr>(); 5759 } 5760 5761 // Determine the result type 5762 QualType ResultTy 5763 = FnDecl->getType()->getAs<FunctionType>()->getResultType(); 5764 ResultTy = ResultTy.getNonReferenceType(); 5765 5766 // Build the actual expression node. 5767 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 5768 OpLoc); 5769 UsualUnaryConversions(FnExpr); 5770 5771 ExprOwningPtr<CXXOperatorCallExpr> 5772 TheCall(this, new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 5773 Args, 2, ResultTy, 5774 OpLoc)); 5775 5776 if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall.get(), 5777 FnDecl)) 5778 return ExprError(); 5779 5780 return MaybeBindToTemporary(TheCall.release()); 5781 } else { 5782 // We matched a built-in operator. Convert the arguments, then 5783 // break out so that we will build the appropriate built-in 5784 // operator node. 5785 if (PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 5786 Best->Conversions[0], AA_Passing) || 5787 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 5788 Best->Conversions[1], AA_Passing)) 5789 return ExprError(); 5790 5791 break; 5792 } 5793 } 5794 5795 case OR_No_Viable_Function: { 5796 // C++ [over.match.oper]p9: 5797 // If the operator is the operator , [...] and there are no 5798 // viable functions, then the operator is assumed to be the 5799 // built-in operator and interpreted according to clause 5. 5800 if (Opc == BinaryOperator::Comma) 5801 break; 5802 5803 // For class as left operand for assignment or compound assigment operator 5804 // do not fall through to handling in built-in, but report that no overloaded 5805 // assignment operator found 5806 OwningExprResult Result = ExprError(); 5807 if (Args[0]->getType()->isRecordType() && 5808 Opc >= BinaryOperator::Assign && Opc <= BinaryOperator::OrAssign) { 5809 Diag(OpLoc, diag::err_ovl_no_viable_oper) 5810 << BinaryOperator::getOpcodeStr(Opc) 5811 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 5812 } else { 5813 // No viable function; try to create a built-in operation, which will 5814 // produce an error. Then, show the non-viable candidates. 5815 Result = CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 5816 } 5817 assert(Result.isInvalid() && 5818 "C++ binary operator overloading is missing candidates!"); 5819 if (Result.isInvalid()) 5820 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2, 5821 BinaryOperator::getOpcodeStr(Opc), OpLoc); 5822 return move(Result); 5823 } 5824 5825 case OR_Ambiguous: 5826 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 5827 << BinaryOperator::getOpcodeStr(Opc) 5828 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 5829 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, 2, 5830 BinaryOperator::getOpcodeStr(Opc), OpLoc); 5831 return ExprError(); 5832 5833 case OR_Deleted: 5834 Diag(OpLoc, diag::err_ovl_deleted_oper) 5835 << Best->Function->isDeleted() 5836 << BinaryOperator::getOpcodeStr(Opc) 5837 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 5838 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2); 5839 return ExprError(); 5840 } 5841 5842 // We matched a built-in operator; build it. 5843 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 5844} 5845 5846Action::OwningExprResult 5847Sema::CreateOverloadedArraySubscriptExpr(SourceLocation LLoc, 5848 SourceLocation RLoc, 5849 ExprArg Base, ExprArg Idx) { 5850 Expr *Args[2] = { static_cast<Expr*>(Base.get()), 5851 static_cast<Expr*>(Idx.get()) }; 5852 DeclarationName OpName = 5853 Context.DeclarationNames.getCXXOperatorName(OO_Subscript); 5854 5855 // If either side is type-dependent, create an appropriate dependent 5856 // expression. 5857 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 5858 5859 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 5860 UnresolvedLookupExpr *Fn 5861 = UnresolvedLookupExpr::Create(Context, /*Dependent*/ true, NamingClass, 5862 0, SourceRange(), OpName, LLoc, 5863 /*ADL*/ true, /*Overloaded*/ false); 5864 // Can't add any actual overloads yet 5865 5866 Base.release(); 5867 Idx.release(); 5868 return Owned(new (Context) CXXOperatorCallExpr(Context, OO_Subscript, Fn, 5869 Args, 2, 5870 Context.DependentTy, 5871 RLoc)); 5872 } 5873 5874 // Build an empty overload set. 5875 OverloadCandidateSet CandidateSet(LLoc); 5876 5877 // Subscript can only be overloaded as a member function. 5878 5879 // Add operator candidates that are member functions. 5880 AddMemberOperatorCandidates(OO_Subscript, LLoc, Args, 2, CandidateSet); 5881 5882 // Add builtin operator candidates. 5883 AddBuiltinOperatorCandidates(OO_Subscript, LLoc, Args, 2, CandidateSet); 5884 5885 // Perform overload resolution. 5886 OverloadCandidateSet::iterator Best; 5887 switch (BestViableFunction(CandidateSet, LLoc, Best)) { 5888 case OR_Success: { 5889 // We found a built-in operator or an overloaded operator. 5890 FunctionDecl *FnDecl = Best->Function; 5891 5892 if (FnDecl) { 5893 // We matched an overloaded operator. Build a call to that 5894 // operator. 5895 5896 CheckMemberOperatorAccess(LLoc, Args[0], Args[1], Best->FoundDecl); 5897 5898 // Convert the arguments. 5899 CXXMethodDecl *Method = cast<CXXMethodDecl>(FnDecl); 5900 if (PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/0, 5901 Best->FoundDecl, Method)) 5902 return ExprError(); 5903 5904 // Convert the arguments. 5905 OwningExprResult InputInit 5906 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 5907 FnDecl->getParamDecl(0)), 5908 SourceLocation(), 5909 Owned(Args[1])); 5910 if (InputInit.isInvalid()) 5911 return ExprError(); 5912 5913 Args[1] = InputInit.takeAs<Expr>(); 5914 5915 // Determine the result type 5916 QualType ResultTy 5917 = FnDecl->getType()->getAs<FunctionType>()->getResultType(); 5918 ResultTy = ResultTy.getNonReferenceType(); 5919 5920 // Build the actual expression node. 5921 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 5922 LLoc); 5923 UsualUnaryConversions(FnExpr); 5924 5925 Base.release(); 5926 Idx.release(); 5927 ExprOwningPtr<CXXOperatorCallExpr> 5928 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Subscript, 5929 FnExpr, Args, 2, 5930 ResultTy, RLoc)); 5931 5932 if (CheckCallReturnType(FnDecl->getResultType(), LLoc, TheCall.get(), 5933 FnDecl)) 5934 return ExprError(); 5935 5936 return MaybeBindToTemporary(TheCall.release()); 5937 } else { 5938 // We matched a built-in operator. Convert the arguments, then 5939 // break out so that we will build the appropriate built-in 5940 // operator node. 5941 if (PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 5942 Best->Conversions[0], AA_Passing) || 5943 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 5944 Best->Conversions[1], AA_Passing)) 5945 return ExprError(); 5946 5947 break; 5948 } 5949 } 5950 5951 case OR_No_Viable_Function: { 5952 if (CandidateSet.empty()) 5953 Diag(LLoc, diag::err_ovl_no_oper) 5954 << Args[0]->getType() << /*subscript*/ 0 5955 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 5956 else 5957 Diag(LLoc, diag::err_ovl_no_viable_subscript) 5958 << Args[0]->getType() 5959 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 5960 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2, 5961 "[]", LLoc); 5962 return ExprError(); 5963 } 5964 5965 case OR_Ambiguous: 5966 Diag(LLoc, diag::err_ovl_ambiguous_oper) 5967 << "[]" << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 5968 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, 2, 5969 "[]", LLoc); 5970 return ExprError(); 5971 5972 case OR_Deleted: 5973 Diag(LLoc, diag::err_ovl_deleted_oper) 5974 << Best->Function->isDeleted() << "[]" 5975 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 5976 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2, 5977 "[]", LLoc); 5978 return ExprError(); 5979 } 5980 5981 // We matched a built-in operator; build it. 5982 Base.release(); 5983 Idx.release(); 5984 return CreateBuiltinArraySubscriptExpr(Owned(Args[0]), LLoc, 5985 Owned(Args[1]), RLoc); 5986} 5987 5988/// BuildCallToMemberFunction - Build a call to a member 5989/// function. MemExpr is the expression that refers to the member 5990/// function (and includes the object parameter), Args/NumArgs are the 5991/// arguments to the function call (not including the object 5992/// parameter). The caller needs to validate that the member 5993/// expression refers to a member function or an overloaded member 5994/// function. 5995Sema::OwningExprResult 5996Sema::BuildCallToMemberFunction(Scope *S, Expr *MemExprE, 5997 SourceLocation LParenLoc, Expr **Args, 5998 unsigned NumArgs, SourceLocation *CommaLocs, 5999 SourceLocation RParenLoc) { 6000 // Dig out the member expression. This holds both the object 6001 // argument and the member function we're referring to. 6002 Expr *NakedMemExpr = MemExprE->IgnoreParens(); 6003 6004 MemberExpr *MemExpr; 6005 CXXMethodDecl *Method = 0; 6006 DeclAccessPair FoundDecl = DeclAccessPair::make(0, AS_public); 6007 NestedNameSpecifier *Qualifier = 0; 6008 if (isa<MemberExpr>(NakedMemExpr)) { 6009 MemExpr = cast<MemberExpr>(NakedMemExpr); 6010 Method = cast<CXXMethodDecl>(MemExpr->getMemberDecl()); 6011 FoundDecl = MemExpr->getFoundDecl(); 6012 Qualifier = MemExpr->getQualifier(); 6013 } else { 6014 UnresolvedMemberExpr *UnresExpr = cast<UnresolvedMemberExpr>(NakedMemExpr); 6015 Qualifier = UnresExpr->getQualifier(); 6016 6017 QualType ObjectType = UnresExpr->getBaseType(); 6018 6019 // Add overload candidates 6020 OverloadCandidateSet CandidateSet(UnresExpr->getMemberLoc()); 6021 6022 // FIXME: avoid copy. 6023 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 6024 if (UnresExpr->hasExplicitTemplateArgs()) { 6025 UnresExpr->copyTemplateArgumentsInto(TemplateArgsBuffer); 6026 TemplateArgs = &TemplateArgsBuffer; 6027 } 6028 6029 for (UnresolvedMemberExpr::decls_iterator I = UnresExpr->decls_begin(), 6030 E = UnresExpr->decls_end(); I != E; ++I) { 6031 6032 NamedDecl *Func = *I; 6033 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(Func->getDeclContext()); 6034 if (isa<UsingShadowDecl>(Func)) 6035 Func = cast<UsingShadowDecl>(Func)->getTargetDecl(); 6036 6037 if ((Method = dyn_cast<CXXMethodDecl>(Func))) { 6038 // If explicit template arguments were provided, we can't call a 6039 // non-template member function. 6040 if (TemplateArgs) 6041 continue; 6042 6043 AddMethodCandidate(Method, I.getPair(), ActingDC, ObjectType, 6044 Args, NumArgs, 6045 CandidateSet, /*SuppressUserConversions=*/false); 6046 } else { 6047 AddMethodTemplateCandidate(cast<FunctionTemplateDecl>(Func), 6048 I.getPair(), ActingDC, TemplateArgs, 6049 ObjectType, Args, NumArgs, 6050 CandidateSet, 6051 /*SuppressUsedConversions=*/false); 6052 } 6053 } 6054 6055 DeclarationName DeclName = UnresExpr->getMemberName(); 6056 6057 OverloadCandidateSet::iterator Best; 6058 switch (BestViableFunction(CandidateSet, UnresExpr->getLocStart(), Best)) { 6059 case OR_Success: 6060 Method = cast<CXXMethodDecl>(Best->Function); 6061 FoundDecl = Best->FoundDecl; 6062 CheckUnresolvedMemberAccess(UnresExpr, Best->FoundDecl); 6063 break; 6064 6065 case OR_No_Viable_Function: 6066 Diag(UnresExpr->getMemberLoc(), 6067 diag::err_ovl_no_viable_member_function_in_call) 6068 << DeclName << MemExprE->getSourceRange(); 6069 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6070 // FIXME: Leaking incoming expressions! 6071 return ExprError(); 6072 6073 case OR_Ambiguous: 6074 Diag(UnresExpr->getMemberLoc(), diag::err_ovl_ambiguous_member_call) 6075 << DeclName << MemExprE->getSourceRange(); 6076 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6077 // FIXME: Leaking incoming expressions! 6078 return ExprError(); 6079 6080 case OR_Deleted: 6081 Diag(UnresExpr->getMemberLoc(), diag::err_ovl_deleted_member_call) 6082 << Best->Function->isDeleted() 6083 << DeclName << MemExprE->getSourceRange(); 6084 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6085 // FIXME: Leaking incoming expressions! 6086 return ExprError(); 6087 } 6088 6089 MemExprE = FixOverloadedFunctionReference(MemExprE, FoundDecl, Method); 6090 6091 // If overload resolution picked a static member, build a 6092 // non-member call based on that function. 6093 if (Method->isStatic()) { 6094 return BuildResolvedCallExpr(MemExprE, Method, LParenLoc, 6095 Args, NumArgs, RParenLoc); 6096 } 6097 6098 MemExpr = cast<MemberExpr>(MemExprE->IgnoreParens()); 6099 } 6100 6101 assert(Method && "Member call to something that isn't a method?"); 6102 ExprOwningPtr<CXXMemberCallExpr> 6103 TheCall(this, new (Context) CXXMemberCallExpr(Context, MemExprE, Args, 6104 NumArgs, 6105 Method->getResultType().getNonReferenceType(), 6106 RParenLoc)); 6107 6108 // Check for a valid return type. 6109 if (CheckCallReturnType(Method->getResultType(), MemExpr->getMemberLoc(), 6110 TheCall.get(), Method)) 6111 return ExprError(); 6112 6113 // Convert the object argument (for a non-static member function call). 6114 // We only need to do this if there was actually an overload; otherwise 6115 // it was done at lookup. 6116 Expr *ObjectArg = MemExpr->getBase(); 6117 if (!Method->isStatic() && 6118 PerformObjectArgumentInitialization(ObjectArg, Qualifier, 6119 FoundDecl, Method)) 6120 return ExprError(); 6121 MemExpr->setBase(ObjectArg); 6122 6123 // Convert the rest of the arguments 6124 const FunctionProtoType *Proto = cast<FunctionProtoType>(Method->getType()); 6125 if (ConvertArgumentsForCall(&*TheCall, MemExpr, Method, Proto, Args, NumArgs, 6126 RParenLoc)) 6127 return ExprError(); 6128 6129 if (CheckFunctionCall(Method, TheCall.get())) 6130 return ExprError(); 6131 6132 return MaybeBindToTemporary(TheCall.release()); 6133} 6134 6135/// BuildCallToObjectOfClassType - Build a call to an object of class 6136/// type (C++ [over.call.object]), which can end up invoking an 6137/// overloaded function call operator (@c operator()) or performing a 6138/// user-defined conversion on the object argument. 6139Sema::ExprResult 6140Sema::BuildCallToObjectOfClassType(Scope *S, Expr *Object, 6141 SourceLocation LParenLoc, 6142 Expr **Args, unsigned NumArgs, 6143 SourceLocation *CommaLocs, 6144 SourceLocation RParenLoc) { 6145 assert(Object->getType()->isRecordType() && "Requires object type argument"); 6146 const RecordType *Record = Object->getType()->getAs<RecordType>(); 6147 6148 // C++ [over.call.object]p1: 6149 // If the primary-expression E in the function call syntax 6150 // evaluates to a class object of type "cv T", then the set of 6151 // candidate functions includes at least the function call 6152 // operators of T. The function call operators of T are obtained by 6153 // ordinary lookup of the name operator() in the context of 6154 // (E).operator(). 6155 OverloadCandidateSet CandidateSet(LParenLoc); 6156 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Call); 6157 6158 if (RequireCompleteType(LParenLoc, Object->getType(), 6159 PDiag(diag::err_incomplete_object_call) 6160 << Object->getSourceRange())) 6161 return true; 6162 6163 LookupResult R(*this, OpName, LParenLoc, LookupOrdinaryName); 6164 LookupQualifiedName(R, Record->getDecl()); 6165 R.suppressDiagnostics(); 6166 6167 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 6168 Oper != OperEnd; ++Oper) { 6169 AddMethodCandidate(Oper.getPair(), Object->getType(), 6170 Args, NumArgs, CandidateSet, 6171 /*SuppressUserConversions=*/ false); 6172 } 6173 6174 // C++ [over.call.object]p2: 6175 // In addition, for each conversion function declared in T of the 6176 // form 6177 // 6178 // operator conversion-type-id () cv-qualifier; 6179 // 6180 // where cv-qualifier is the same cv-qualification as, or a 6181 // greater cv-qualification than, cv, and where conversion-type-id 6182 // denotes the type "pointer to function of (P1,...,Pn) returning 6183 // R", or the type "reference to pointer to function of 6184 // (P1,...,Pn) returning R", or the type "reference to function 6185 // of (P1,...,Pn) returning R", a surrogate call function [...] 6186 // is also considered as a candidate function. Similarly, 6187 // surrogate call functions are added to the set of candidate 6188 // functions for each conversion function declared in an 6189 // accessible base class provided the function is not hidden 6190 // within T by another intervening declaration. 6191 const UnresolvedSetImpl *Conversions 6192 = cast<CXXRecordDecl>(Record->getDecl())->getVisibleConversionFunctions(); 6193 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 6194 E = Conversions->end(); I != E; ++I) { 6195 NamedDecl *D = *I; 6196 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext()); 6197 if (isa<UsingShadowDecl>(D)) 6198 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 6199 6200 // Skip over templated conversion functions; they aren't 6201 // surrogates. 6202 if (isa<FunctionTemplateDecl>(D)) 6203 continue; 6204 6205 CXXConversionDecl *Conv = cast<CXXConversionDecl>(D); 6206 6207 // Strip the reference type (if any) and then the pointer type (if 6208 // any) to get down to what might be a function type. 6209 QualType ConvType = Conv->getConversionType().getNonReferenceType(); 6210 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 6211 ConvType = ConvPtrType->getPointeeType(); 6212 6213 if (const FunctionProtoType *Proto = ConvType->getAs<FunctionProtoType>()) 6214 AddSurrogateCandidate(Conv, I.getPair(), ActingContext, Proto, 6215 Object->getType(), Args, NumArgs, 6216 CandidateSet); 6217 } 6218 6219 // Perform overload resolution. 6220 OverloadCandidateSet::iterator Best; 6221 switch (BestViableFunction(CandidateSet, Object->getLocStart(), Best)) { 6222 case OR_Success: 6223 // Overload resolution succeeded; we'll build the appropriate call 6224 // below. 6225 break; 6226 6227 case OR_No_Viable_Function: 6228 if (CandidateSet.empty()) 6229 Diag(Object->getSourceRange().getBegin(), diag::err_ovl_no_oper) 6230 << Object->getType() << /*call*/ 1 6231 << Object->getSourceRange(); 6232 else 6233 Diag(Object->getSourceRange().getBegin(), 6234 diag::err_ovl_no_viable_object_call) 6235 << Object->getType() << Object->getSourceRange(); 6236 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6237 break; 6238 6239 case OR_Ambiguous: 6240 Diag(Object->getSourceRange().getBegin(), 6241 diag::err_ovl_ambiguous_object_call) 6242 << Object->getType() << Object->getSourceRange(); 6243 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, NumArgs); 6244 break; 6245 6246 case OR_Deleted: 6247 Diag(Object->getSourceRange().getBegin(), 6248 diag::err_ovl_deleted_object_call) 6249 << Best->Function->isDeleted() 6250 << Object->getType() << Object->getSourceRange(); 6251 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6252 break; 6253 } 6254 6255 if (Best == CandidateSet.end()) { 6256 // We had an error; delete all of the subexpressions and return 6257 // the error. 6258 Object->Destroy(Context); 6259 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 6260 Args[ArgIdx]->Destroy(Context); 6261 return true; 6262 } 6263 6264 if (Best->Function == 0) { 6265 // Since there is no function declaration, this is one of the 6266 // surrogate candidates. Dig out the conversion function. 6267 CXXConversionDecl *Conv 6268 = cast<CXXConversionDecl>( 6269 Best->Conversions[0].UserDefined.ConversionFunction); 6270 6271 CheckMemberOperatorAccess(LParenLoc, Object, 0, Best->FoundDecl); 6272 6273 // We selected one of the surrogate functions that converts the 6274 // object parameter to a function pointer. Perform the conversion 6275 // on the object argument, then let ActOnCallExpr finish the job. 6276 6277 // Create an implicit member expr to refer to the conversion operator. 6278 // and then call it. 6279 CXXMemberCallExpr *CE = BuildCXXMemberCallExpr(Object, Best->FoundDecl, 6280 Conv); 6281 6282 return ActOnCallExpr(S, ExprArg(*this, CE), LParenLoc, 6283 MultiExprArg(*this, (ExprTy**)Args, NumArgs), 6284 CommaLocs, RParenLoc).release(); 6285 } 6286 6287 CheckMemberOperatorAccess(LParenLoc, Object, 0, Best->FoundDecl); 6288 6289 // We found an overloaded operator(). Build a CXXOperatorCallExpr 6290 // that calls this method, using Object for the implicit object 6291 // parameter and passing along the remaining arguments. 6292 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 6293 const FunctionProtoType *Proto = Method->getType()->getAs<FunctionProtoType>(); 6294 6295 unsigned NumArgsInProto = Proto->getNumArgs(); 6296 unsigned NumArgsToCheck = NumArgs; 6297 6298 // Build the full argument list for the method call (the 6299 // implicit object parameter is placed at the beginning of the 6300 // list). 6301 Expr **MethodArgs; 6302 if (NumArgs < NumArgsInProto) { 6303 NumArgsToCheck = NumArgsInProto; 6304 MethodArgs = new Expr*[NumArgsInProto + 1]; 6305 } else { 6306 MethodArgs = new Expr*[NumArgs + 1]; 6307 } 6308 MethodArgs[0] = Object; 6309 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 6310 MethodArgs[ArgIdx + 1] = Args[ArgIdx]; 6311 6312 Expr *NewFn = new (Context) DeclRefExpr(Method, Method->getType(), 6313 SourceLocation()); 6314 UsualUnaryConversions(NewFn); 6315 6316 // Once we've built TheCall, all of the expressions are properly 6317 // owned. 6318 QualType ResultTy = Method->getResultType().getNonReferenceType(); 6319 ExprOwningPtr<CXXOperatorCallExpr> 6320 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Call, NewFn, 6321 MethodArgs, NumArgs + 1, 6322 ResultTy, RParenLoc)); 6323 delete [] MethodArgs; 6324 6325 if (CheckCallReturnType(Method->getResultType(), LParenLoc, TheCall.get(), 6326 Method)) 6327 return true; 6328 6329 // We may have default arguments. If so, we need to allocate more 6330 // slots in the call for them. 6331 if (NumArgs < NumArgsInProto) 6332 TheCall->setNumArgs(Context, NumArgsInProto + 1); 6333 else if (NumArgs > NumArgsInProto) 6334 NumArgsToCheck = NumArgsInProto; 6335 6336 bool IsError = false; 6337 6338 // Initialize the implicit object parameter. 6339 IsError |= PerformObjectArgumentInitialization(Object, /*Qualifier=*/0, 6340 Best->FoundDecl, Method); 6341 TheCall->setArg(0, Object); 6342 6343 6344 // Check the argument types. 6345 for (unsigned i = 0; i != NumArgsToCheck; i++) { 6346 Expr *Arg; 6347 if (i < NumArgs) { 6348 Arg = Args[i]; 6349 6350 // Pass the argument. 6351 6352 OwningExprResult InputInit 6353 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 6354 Method->getParamDecl(i)), 6355 SourceLocation(), Owned(Arg)); 6356 6357 IsError |= InputInit.isInvalid(); 6358 Arg = InputInit.takeAs<Expr>(); 6359 } else { 6360 OwningExprResult DefArg 6361 = BuildCXXDefaultArgExpr(LParenLoc, Method, Method->getParamDecl(i)); 6362 if (DefArg.isInvalid()) { 6363 IsError = true; 6364 break; 6365 } 6366 6367 Arg = DefArg.takeAs<Expr>(); 6368 } 6369 6370 TheCall->setArg(i + 1, Arg); 6371 } 6372 6373 // If this is a variadic call, handle args passed through "...". 6374 if (Proto->isVariadic()) { 6375 // Promote the arguments (C99 6.5.2.2p7). 6376 for (unsigned i = NumArgsInProto; i != NumArgs; i++) { 6377 Expr *Arg = Args[i]; 6378 IsError |= DefaultVariadicArgumentPromotion(Arg, VariadicMethod); 6379 TheCall->setArg(i + 1, Arg); 6380 } 6381 } 6382 6383 if (IsError) return true; 6384 6385 if (CheckFunctionCall(Method, TheCall.get())) 6386 return true; 6387 6388 return MaybeBindToTemporary(TheCall.release()).release(); 6389} 6390 6391/// BuildOverloadedArrowExpr - Build a call to an overloaded @c operator-> 6392/// (if one exists), where @c Base is an expression of class type and 6393/// @c Member is the name of the member we're trying to find. 6394Sema::OwningExprResult 6395Sema::BuildOverloadedArrowExpr(Scope *S, ExprArg BaseIn, SourceLocation OpLoc) { 6396 Expr *Base = static_cast<Expr *>(BaseIn.get()); 6397 assert(Base->getType()->isRecordType() && "left-hand side must have class type"); 6398 6399 SourceLocation Loc = Base->getExprLoc(); 6400 6401 // C++ [over.ref]p1: 6402 // 6403 // [...] An expression x->m is interpreted as (x.operator->())->m 6404 // for a class object x of type T if T::operator->() exists and if 6405 // the operator is selected as the best match function by the 6406 // overload resolution mechanism (13.3). 6407 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Arrow); 6408 OverloadCandidateSet CandidateSet(Loc); 6409 const RecordType *BaseRecord = Base->getType()->getAs<RecordType>(); 6410 6411 if (RequireCompleteType(Loc, Base->getType(), 6412 PDiag(diag::err_typecheck_incomplete_tag) 6413 << Base->getSourceRange())) 6414 return ExprError(); 6415 6416 LookupResult R(*this, OpName, OpLoc, LookupOrdinaryName); 6417 LookupQualifiedName(R, BaseRecord->getDecl()); 6418 R.suppressDiagnostics(); 6419 6420 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 6421 Oper != OperEnd; ++Oper) { 6422 AddMethodCandidate(Oper.getPair(), Base->getType(), 0, 0, CandidateSet, 6423 /*SuppressUserConversions=*/false); 6424 } 6425 6426 // Perform overload resolution. 6427 OverloadCandidateSet::iterator Best; 6428 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 6429 case OR_Success: 6430 // Overload resolution succeeded; we'll build the call below. 6431 break; 6432 6433 case OR_No_Viable_Function: 6434 if (CandidateSet.empty()) 6435 Diag(OpLoc, diag::err_typecheck_member_reference_arrow) 6436 << Base->getType() << Base->getSourceRange(); 6437 else 6438 Diag(OpLoc, diag::err_ovl_no_viable_oper) 6439 << "operator->" << Base->getSourceRange(); 6440 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, &Base, 1); 6441 return ExprError(); 6442 6443 case OR_Ambiguous: 6444 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 6445 << "->" << Base->getSourceRange(); 6446 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, &Base, 1); 6447 return ExprError(); 6448 6449 case OR_Deleted: 6450 Diag(OpLoc, diag::err_ovl_deleted_oper) 6451 << Best->Function->isDeleted() 6452 << "->" << Base->getSourceRange(); 6453 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, &Base, 1); 6454 return ExprError(); 6455 } 6456 6457 CheckMemberOperatorAccess(OpLoc, Base, 0, Best->FoundDecl); 6458 6459 // Convert the object parameter. 6460 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 6461 if (PerformObjectArgumentInitialization(Base, /*Qualifier=*/0, 6462 Best->FoundDecl, Method)) 6463 return ExprError(); 6464 6465 // No concerns about early exits now. 6466 BaseIn.release(); 6467 6468 // Build the operator call. 6469 Expr *FnExpr = new (Context) DeclRefExpr(Method, Method->getType(), 6470 SourceLocation()); 6471 UsualUnaryConversions(FnExpr); 6472 6473 QualType ResultTy = Method->getResultType().getNonReferenceType(); 6474 ExprOwningPtr<CXXOperatorCallExpr> 6475 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Arrow, FnExpr, 6476 &Base, 1, ResultTy, OpLoc)); 6477 6478 if (CheckCallReturnType(Method->getResultType(), OpLoc, TheCall.get(), 6479 Method)) 6480 return ExprError(); 6481 return move(TheCall); 6482} 6483 6484/// FixOverloadedFunctionReference - E is an expression that refers to 6485/// a C++ overloaded function (possibly with some parentheses and 6486/// perhaps a '&' around it). We have resolved the overloaded function 6487/// to the function declaration Fn, so patch up the expression E to 6488/// refer (possibly indirectly) to Fn. Returns the new expr. 6489Expr *Sema::FixOverloadedFunctionReference(Expr *E, DeclAccessPair Found, 6490 FunctionDecl *Fn) { 6491 if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) { 6492 Expr *SubExpr = FixOverloadedFunctionReference(PE->getSubExpr(), 6493 Found, Fn); 6494 if (SubExpr == PE->getSubExpr()) 6495 return PE->Retain(); 6496 6497 return new (Context) ParenExpr(PE->getLParen(), PE->getRParen(), SubExpr); 6498 } 6499 6500 if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) { 6501 Expr *SubExpr = FixOverloadedFunctionReference(ICE->getSubExpr(), 6502 Found, Fn); 6503 assert(Context.hasSameType(ICE->getSubExpr()->getType(), 6504 SubExpr->getType()) && 6505 "Implicit cast type cannot be determined from overload"); 6506 if (SubExpr == ICE->getSubExpr()) 6507 return ICE->Retain(); 6508 6509 return new (Context) ImplicitCastExpr(ICE->getType(), 6510 ICE->getCastKind(), 6511 SubExpr, 6512 ICE->isLvalueCast()); 6513 } 6514 6515 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(E)) { 6516 assert(UnOp->getOpcode() == UnaryOperator::AddrOf && 6517 "Can only take the address of an overloaded function"); 6518 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 6519 if (Method->isStatic()) { 6520 // Do nothing: static member functions aren't any different 6521 // from non-member functions. 6522 } else { 6523 // Fix the sub expression, which really has to be an 6524 // UnresolvedLookupExpr holding an overloaded member function 6525 // or template. 6526 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(), 6527 Found, Fn); 6528 if (SubExpr == UnOp->getSubExpr()) 6529 return UnOp->Retain(); 6530 6531 assert(isa<DeclRefExpr>(SubExpr) 6532 && "fixed to something other than a decl ref"); 6533 assert(cast<DeclRefExpr>(SubExpr)->getQualifier() 6534 && "fixed to a member ref with no nested name qualifier"); 6535 6536 // We have taken the address of a pointer to member 6537 // function. Perform the computation here so that we get the 6538 // appropriate pointer to member type. 6539 QualType ClassType 6540 = Context.getTypeDeclType(cast<RecordDecl>(Method->getDeclContext())); 6541 QualType MemPtrType 6542 = Context.getMemberPointerType(Fn->getType(), ClassType.getTypePtr()); 6543 6544 return new (Context) UnaryOperator(SubExpr, UnaryOperator::AddrOf, 6545 MemPtrType, UnOp->getOperatorLoc()); 6546 } 6547 } 6548 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(), 6549 Found, Fn); 6550 if (SubExpr == UnOp->getSubExpr()) 6551 return UnOp->Retain(); 6552 6553 return new (Context) UnaryOperator(SubExpr, UnaryOperator::AddrOf, 6554 Context.getPointerType(SubExpr->getType()), 6555 UnOp->getOperatorLoc()); 6556 } 6557 6558 if (UnresolvedLookupExpr *ULE = dyn_cast<UnresolvedLookupExpr>(E)) { 6559 // FIXME: avoid copy. 6560 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 6561 if (ULE->hasExplicitTemplateArgs()) { 6562 ULE->copyTemplateArgumentsInto(TemplateArgsBuffer); 6563 TemplateArgs = &TemplateArgsBuffer; 6564 } 6565 6566 return DeclRefExpr::Create(Context, 6567 ULE->getQualifier(), 6568 ULE->getQualifierRange(), 6569 Fn, 6570 ULE->getNameLoc(), 6571 Fn->getType(), 6572 TemplateArgs); 6573 } 6574 6575 if (UnresolvedMemberExpr *MemExpr = dyn_cast<UnresolvedMemberExpr>(E)) { 6576 // FIXME: avoid copy. 6577 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 6578 if (MemExpr->hasExplicitTemplateArgs()) { 6579 MemExpr->copyTemplateArgumentsInto(TemplateArgsBuffer); 6580 TemplateArgs = &TemplateArgsBuffer; 6581 } 6582 6583 Expr *Base; 6584 6585 // If we're filling in 6586 if (MemExpr->isImplicitAccess()) { 6587 if (cast<CXXMethodDecl>(Fn)->isStatic()) { 6588 return DeclRefExpr::Create(Context, 6589 MemExpr->getQualifier(), 6590 MemExpr->getQualifierRange(), 6591 Fn, 6592 MemExpr->getMemberLoc(), 6593 Fn->getType(), 6594 TemplateArgs); 6595 } else { 6596 SourceLocation Loc = MemExpr->getMemberLoc(); 6597 if (MemExpr->getQualifier()) 6598 Loc = MemExpr->getQualifierRange().getBegin(); 6599 Base = new (Context) CXXThisExpr(Loc, 6600 MemExpr->getBaseType(), 6601 /*isImplicit=*/true); 6602 } 6603 } else 6604 Base = MemExpr->getBase()->Retain(); 6605 6606 return MemberExpr::Create(Context, Base, 6607 MemExpr->isArrow(), 6608 MemExpr->getQualifier(), 6609 MemExpr->getQualifierRange(), 6610 Fn, 6611 Found, 6612 MemExpr->getMemberLoc(), 6613 TemplateArgs, 6614 Fn->getType()); 6615 } 6616 6617 assert(false && "Invalid reference to overloaded function"); 6618 return E->Retain(); 6619} 6620 6621Sema::OwningExprResult Sema::FixOverloadedFunctionReference(OwningExprResult E, 6622 DeclAccessPair Found, 6623 FunctionDecl *Fn) { 6624 return Owned(FixOverloadedFunctionReference((Expr *)E.get(), Found, Fn)); 6625} 6626 6627} // end namespace clang 6628