SemaOverload.cpp revision 9aa472c45d2bd81b7b52c225e8acc560d716db97
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 // Lvalue-to-rvalue conversion (C++ 4.1): 571 // An lvalue (3.10) of a non-function, non-array type T can be 572 // converted to an rvalue. 573 Expr::isLvalueResult argIsLvalue = From->isLvalue(Context); 574 if (argIsLvalue == Expr::LV_Valid && 575 !FromType->isFunctionType() && !FromType->isArrayType() && 576 Context.getCanonicalType(FromType) != Context.OverloadTy) { 577 SCS.First = ICK_Lvalue_To_Rvalue; 578 579 // If T is a non-class type, the type of the rvalue is the 580 // cv-unqualified version of T. Otherwise, the type of the rvalue 581 // is T (C++ 4.1p1). C++ can't get here with class types; in C, we 582 // just strip the qualifiers because they don't matter. 583 FromType = FromType.getUnqualifiedType(); 584 } else if (FromType->isArrayType()) { 585 // Array-to-pointer conversion (C++ 4.2) 586 SCS.First = ICK_Array_To_Pointer; 587 588 // An lvalue or rvalue of type "array of N T" or "array of unknown 589 // bound of T" can be converted to an rvalue of type "pointer to 590 // T" (C++ 4.2p1). 591 FromType = Context.getArrayDecayedType(FromType); 592 593 if (IsStringLiteralToNonConstPointerConversion(From, ToType)) { 594 // This conversion is deprecated. (C++ D.4). 595 SCS.DeprecatedStringLiteralToCharPtr = true; 596 597 // For the purpose of ranking in overload resolution 598 // (13.3.3.1.1), this conversion is considered an 599 // array-to-pointer conversion followed by a qualification 600 // conversion (4.4). (C++ 4.2p2) 601 SCS.Second = ICK_Identity; 602 SCS.Third = ICK_Qualification; 603 SCS.setAllToTypes(FromType); 604 return true; 605 } 606 } else if (FromType->isFunctionType() && argIsLvalue == Expr::LV_Valid) { 607 // Function-to-pointer conversion (C++ 4.3). 608 SCS.First = ICK_Function_To_Pointer; 609 610 // An lvalue of function type T can be converted to an rvalue of 611 // type "pointer to T." The result is a pointer to the 612 // function. (C++ 4.3p1). 613 FromType = Context.getPointerType(FromType); 614 } else if (FunctionDecl *Fn 615 = ResolveAddressOfOverloadedFunction(From, ToType, false)) { 616 // Address of overloaded function (C++ [over.over]). 617 SCS.First = ICK_Function_To_Pointer; 618 619 // We were able to resolve the address of the overloaded function, 620 // so we can convert to the type of that function. 621 FromType = Fn->getType(); 622 if (ToType->isLValueReferenceType()) 623 FromType = Context.getLValueReferenceType(FromType); 624 else if (ToType->isRValueReferenceType()) 625 FromType = Context.getRValueReferenceType(FromType); 626 else if (ToType->isMemberPointerType()) { 627 // Resolve address only succeeds if both sides are member pointers, 628 // but it doesn't have to be the same class. See DR 247. 629 // Note that this means that the type of &Derived::fn can be 630 // Ret (Base::*)(Args) if the fn overload actually found is from the 631 // base class, even if it was brought into the derived class via a 632 // using declaration. The standard isn't clear on this issue at all. 633 CXXMethodDecl *M = cast<CXXMethodDecl>(Fn); 634 FromType = Context.getMemberPointerType(FromType, 635 Context.getTypeDeclType(M->getParent()).getTypePtr()); 636 } else 637 FromType = Context.getPointerType(FromType); 638 } else { 639 // We don't require any conversions for the first step. 640 SCS.First = ICK_Identity; 641 } 642 SCS.setToType(0, FromType); 643 644 // The second conversion can be an integral promotion, floating 645 // point promotion, integral conversion, floating point conversion, 646 // floating-integral conversion, pointer conversion, 647 // pointer-to-member conversion, or boolean conversion (C++ 4p1). 648 // For overloading in C, this can also be a "compatible-type" 649 // conversion. 650 bool IncompatibleObjC = false; 651 if (Context.hasSameUnqualifiedType(FromType, ToType)) { 652 // The unqualified versions of the types are the same: there's no 653 // conversion to do. 654 SCS.Second = ICK_Identity; 655 } else if (IsIntegralPromotion(From, FromType, ToType)) { 656 // Integral promotion (C++ 4.5). 657 SCS.Second = ICK_Integral_Promotion; 658 FromType = ToType.getUnqualifiedType(); 659 } else if (IsFloatingPointPromotion(FromType, ToType)) { 660 // Floating point promotion (C++ 4.6). 661 SCS.Second = ICK_Floating_Promotion; 662 FromType = ToType.getUnqualifiedType(); 663 } else if (IsComplexPromotion(FromType, ToType)) { 664 // Complex promotion (Clang extension) 665 SCS.Second = ICK_Complex_Promotion; 666 FromType = ToType.getUnqualifiedType(); 667 } else if ((FromType->isIntegralType() || FromType->isEnumeralType()) && 668 (ToType->isIntegralType() && !ToType->isEnumeralType())) { 669 // Integral conversions (C++ 4.7). 670 SCS.Second = ICK_Integral_Conversion; 671 FromType = ToType.getUnqualifiedType(); 672 } else if (FromType->isComplexType() && ToType->isComplexType()) { 673 // Complex conversions (C99 6.3.1.6) 674 SCS.Second = ICK_Complex_Conversion; 675 FromType = ToType.getUnqualifiedType(); 676 } else if ((FromType->isComplexType() && ToType->isArithmeticType()) || 677 (ToType->isComplexType() && FromType->isArithmeticType())) { 678 // Complex-real conversions (C99 6.3.1.7) 679 SCS.Second = ICK_Complex_Real; 680 FromType = ToType.getUnqualifiedType(); 681 } else if (FromType->isFloatingType() && ToType->isFloatingType()) { 682 // Floating point conversions (C++ 4.8). 683 SCS.Second = ICK_Floating_Conversion; 684 FromType = ToType.getUnqualifiedType(); 685 } else if ((FromType->isFloatingType() && 686 ToType->isIntegralType() && (!ToType->isBooleanType() && 687 !ToType->isEnumeralType())) || 688 ((FromType->isIntegralType() || FromType->isEnumeralType()) && 689 ToType->isFloatingType())) { 690 // Floating-integral conversions (C++ 4.9). 691 SCS.Second = ICK_Floating_Integral; 692 FromType = ToType.getUnqualifiedType(); 693 } else if (IsPointerConversion(From, FromType, ToType, InOverloadResolution, 694 FromType, IncompatibleObjC)) { 695 // Pointer conversions (C++ 4.10). 696 SCS.Second = ICK_Pointer_Conversion; 697 SCS.IncompatibleObjC = IncompatibleObjC; 698 } else if (IsMemberPointerConversion(From, FromType, ToType, 699 InOverloadResolution, FromType)) { 700 // Pointer to member conversions (4.11). 701 SCS.Second = ICK_Pointer_Member; 702 } else if (ToType->isBooleanType() && 703 (FromType->isArithmeticType() || 704 FromType->isEnumeralType() || 705 FromType->isAnyPointerType() || 706 FromType->isBlockPointerType() || 707 FromType->isMemberPointerType() || 708 FromType->isNullPtrType())) { 709 // Boolean conversions (C++ 4.12). 710 SCS.Second = ICK_Boolean_Conversion; 711 FromType = Context.BoolTy; 712 } else if (!getLangOptions().CPlusPlus && 713 Context.typesAreCompatible(ToType, FromType)) { 714 // Compatible conversions (Clang extension for C function overloading) 715 SCS.Second = ICK_Compatible_Conversion; 716 } else if (IsNoReturnConversion(Context, FromType, ToType, FromType)) { 717 // Treat a conversion that strips "noreturn" as an identity conversion. 718 SCS.Second = ICK_NoReturn_Adjustment; 719 } else { 720 // No second conversion required. 721 SCS.Second = ICK_Identity; 722 } 723 SCS.setToType(1, FromType); 724 725 QualType CanonFrom; 726 QualType CanonTo; 727 // The third conversion can be a qualification conversion (C++ 4p1). 728 if (IsQualificationConversion(FromType, ToType)) { 729 SCS.Third = ICK_Qualification; 730 FromType = ToType; 731 CanonFrom = Context.getCanonicalType(FromType); 732 CanonTo = Context.getCanonicalType(ToType); 733 } else { 734 // No conversion required 735 SCS.Third = ICK_Identity; 736 737 // C++ [over.best.ics]p6: 738 // [...] Any difference in top-level cv-qualification is 739 // subsumed by the initialization itself and does not constitute 740 // a conversion. [...] 741 CanonFrom = Context.getCanonicalType(FromType); 742 CanonTo = Context.getCanonicalType(ToType); 743 if (CanonFrom.getLocalUnqualifiedType() 744 == CanonTo.getLocalUnqualifiedType() && 745 CanonFrom.getLocalCVRQualifiers() != CanonTo.getLocalCVRQualifiers()) { 746 FromType = ToType; 747 CanonFrom = CanonTo; 748 } 749 } 750 SCS.setToType(2, FromType); 751 752 // If we have not converted the argument type to the parameter type, 753 // this is a bad conversion sequence. 754 if (CanonFrom != CanonTo) 755 return false; 756 757 return true; 758} 759 760/// IsIntegralPromotion - Determines whether the conversion from the 761/// expression From (whose potentially-adjusted type is FromType) to 762/// ToType is an integral promotion (C++ 4.5). If so, returns true and 763/// sets PromotedType to the promoted type. 764bool Sema::IsIntegralPromotion(Expr *From, QualType FromType, QualType ToType) { 765 const BuiltinType *To = ToType->getAs<BuiltinType>(); 766 // All integers are built-in. 767 if (!To) { 768 return false; 769 } 770 771 // An rvalue of type char, signed char, unsigned char, short int, or 772 // unsigned short int can be converted to an rvalue of type int if 773 // int can represent all the values of the source type; otherwise, 774 // the source rvalue can be converted to an rvalue of type unsigned 775 // int (C++ 4.5p1). 776 if (FromType->isPromotableIntegerType() && !FromType->isBooleanType() && 777 !FromType->isEnumeralType()) { 778 if (// We can promote any signed, promotable integer type to an int 779 (FromType->isSignedIntegerType() || 780 // We can promote any unsigned integer type whose size is 781 // less than int to an int. 782 (!FromType->isSignedIntegerType() && 783 Context.getTypeSize(FromType) < Context.getTypeSize(ToType)))) { 784 return To->getKind() == BuiltinType::Int; 785 } 786 787 return To->getKind() == BuiltinType::UInt; 788 } 789 790 // An rvalue of type wchar_t (3.9.1) or an enumeration type (7.2) 791 // can be converted to an rvalue of the first of the following types 792 // that can represent all the values of its underlying type: int, 793 // unsigned int, long, or unsigned long (C++ 4.5p2). 794 795 // We pre-calculate the promotion type for enum types. 796 if (const EnumType *FromEnumType = FromType->getAs<EnumType>()) 797 if (ToType->isIntegerType()) 798 return Context.hasSameUnqualifiedType(ToType, 799 FromEnumType->getDecl()->getPromotionType()); 800 801 if (FromType->isWideCharType() && ToType->isIntegerType()) { 802 // Determine whether the type we're converting from is signed or 803 // unsigned. 804 bool FromIsSigned; 805 uint64_t FromSize = Context.getTypeSize(FromType); 806 807 // FIXME: Is wchar_t signed or unsigned? We assume it's signed for now. 808 FromIsSigned = true; 809 810 // The types we'll try to promote to, in the appropriate 811 // order. Try each of these types. 812 QualType PromoteTypes[6] = { 813 Context.IntTy, Context.UnsignedIntTy, 814 Context.LongTy, Context.UnsignedLongTy , 815 Context.LongLongTy, Context.UnsignedLongLongTy 816 }; 817 for (int Idx = 0; Idx < 6; ++Idx) { 818 uint64_t ToSize = Context.getTypeSize(PromoteTypes[Idx]); 819 if (FromSize < ToSize || 820 (FromSize == ToSize && 821 FromIsSigned == PromoteTypes[Idx]->isSignedIntegerType())) { 822 // We found the type that we can promote to. If this is the 823 // type we wanted, we have a promotion. Otherwise, no 824 // promotion. 825 return Context.hasSameUnqualifiedType(ToType, PromoteTypes[Idx]); 826 } 827 } 828 } 829 830 // An rvalue for an integral bit-field (9.6) can be converted to an 831 // rvalue of type int if int can represent all the values of the 832 // bit-field; otherwise, it can be converted to unsigned int if 833 // unsigned int can represent all the values of the bit-field. If 834 // the bit-field is larger yet, no integral promotion applies to 835 // it. If the bit-field has an enumerated type, it is treated as any 836 // other value of that type for promotion purposes (C++ 4.5p3). 837 // FIXME: We should delay checking of bit-fields until we actually perform the 838 // conversion. 839 using llvm::APSInt; 840 if (From) 841 if (FieldDecl *MemberDecl = From->getBitField()) { 842 APSInt BitWidth; 843 if (FromType->isIntegralType() && !FromType->isEnumeralType() && 844 MemberDecl->getBitWidth()->isIntegerConstantExpr(BitWidth, Context)) { 845 APSInt ToSize(BitWidth.getBitWidth(), BitWidth.isUnsigned()); 846 ToSize = Context.getTypeSize(ToType); 847 848 // Are we promoting to an int from a bitfield that fits in an int? 849 if (BitWidth < ToSize || 850 (FromType->isSignedIntegerType() && BitWidth <= ToSize)) { 851 return To->getKind() == BuiltinType::Int; 852 } 853 854 // Are we promoting to an unsigned int from an unsigned bitfield 855 // that fits into an unsigned int? 856 if (FromType->isUnsignedIntegerType() && BitWidth <= ToSize) { 857 return To->getKind() == BuiltinType::UInt; 858 } 859 860 return false; 861 } 862 } 863 864 // An rvalue of type bool can be converted to an rvalue of type int, 865 // with false becoming zero and true becoming one (C++ 4.5p4). 866 if (FromType->isBooleanType() && To->getKind() == BuiltinType::Int) { 867 return true; 868 } 869 870 return false; 871} 872 873/// IsFloatingPointPromotion - Determines whether the conversion from 874/// FromType to ToType is a floating point promotion (C++ 4.6). If so, 875/// returns true and sets PromotedType to the promoted type. 876bool Sema::IsFloatingPointPromotion(QualType FromType, QualType ToType) { 877 /// An rvalue of type float can be converted to an rvalue of type 878 /// double. (C++ 4.6p1). 879 if (const BuiltinType *FromBuiltin = FromType->getAs<BuiltinType>()) 880 if (const BuiltinType *ToBuiltin = ToType->getAs<BuiltinType>()) { 881 if (FromBuiltin->getKind() == BuiltinType::Float && 882 ToBuiltin->getKind() == BuiltinType::Double) 883 return true; 884 885 // C99 6.3.1.5p1: 886 // When a float is promoted to double or long double, or a 887 // double is promoted to long double [...]. 888 if (!getLangOptions().CPlusPlus && 889 (FromBuiltin->getKind() == BuiltinType::Float || 890 FromBuiltin->getKind() == BuiltinType::Double) && 891 (ToBuiltin->getKind() == BuiltinType::LongDouble)) 892 return true; 893 } 894 895 return false; 896} 897 898/// \brief Determine if a conversion is a complex promotion. 899/// 900/// A complex promotion is defined as a complex -> complex conversion 901/// where the conversion between the underlying real types is a 902/// floating-point or integral promotion. 903bool Sema::IsComplexPromotion(QualType FromType, QualType ToType) { 904 const ComplexType *FromComplex = FromType->getAs<ComplexType>(); 905 if (!FromComplex) 906 return false; 907 908 const ComplexType *ToComplex = ToType->getAs<ComplexType>(); 909 if (!ToComplex) 910 return false; 911 912 return IsFloatingPointPromotion(FromComplex->getElementType(), 913 ToComplex->getElementType()) || 914 IsIntegralPromotion(0, FromComplex->getElementType(), 915 ToComplex->getElementType()); 916} 917 918/// BuildSimilarlyQualifiedPointerType - In a pointer conversion from 919/// the pointer type FromPtr to a pointer to type ToPointee, with the 920/// same type qualifiers as FromPtr has on its pointee type. ToType, 921/// if non-empty, will be a pointer to ToType that may or may not have 922/// the right set of qualifiers on its pointee. 923static QualType 924BuildSimilarlyQualifiedPointerType(const PointerType *FromPtr, 925 QualType ToPointee, QualType ToType, 926 ASTContext &Context) { 927 QualType CanonFromPointee = Context.getCanonicalType(FromPtr->getPointeeType()); 928 QualType CanonToPointee = Context.getCanonicalType(ToPointee); 929 Qualifiers Quals = CanonFromPointee.getQualifiers(); 930 931 // Exact qualifier match -> return the pointer type we're converting to. 932 if (CanonToPointee.getLocalQualifiers() == Quals) { 933 // ToType is exactly what we need. Return it. 934 if (!ToType.isNull()) 935 return ToType; 936 937 // Build a pointer to ToPointee. It has the right qualifiers 938 // already. 939 return Context.getPointerType(ToPointee); 940 } 941 942 // Just build a canonical type that has the right qualifiers. 943 return Context.getPointerType( 944 Context.getQualifiedType(CanonToPointee.getLocalUnqualifiedType(), 945 Quals)); 946} 947 948/// BuildSimilarlyQualifiedObjCObjectPointerType - In a pointer conversion from 949/// the FromType, which is an objective-c pointer, to ToType, which may or may 950/// not have the right set of qualifiers. 951static QualType 952BuildSimilarlyQualifiedObjCObjectPointerType(QualType FromType, 953 QualType ToType, 954 ASTContext &Context) { 955 QualType CanonFromType = Context.getCanonicalType(FromType); 956 QualType CanonToType = Context.getCanonicalType(ToType); 957 Qualifiers Quals = CanonFromType.getQualifiers(); 958 959 // Exact qualifier match -> return the pointer type we're converting to. 960 if (CanonToType.getLocalQualifiers() == Quals) 961 return ToType; 962 963 // Just build a canonical type that has the right qualifiers. 964 return Context.getQualifiedType(CanonToType.getLocalUnqualifiedType(), Quals); 965} 966 967static bool isNullPointerConstantForConversion(Expr *Expr, 968 bool InOverloadResolution, 969 ASTContext &Context) { 970 // Handle value-dependent integral null pointer constants correctly. 971 // http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#903 972 if (Expr->isValueDependent() && !Expr->isTypeDependent() && 973 Expr->getType()->isIntegralType()) 974 return !InOverloadResolution; 975 976 return Expr->isNullPointerConstant(Context, 977 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull 978 : Expr::NPC_ValueDependentIsNull); 979} 980 981/// IsPointerConversion - Determines whether the conversion of the 982/// expression From, which has the (possibly adjusted) type FromType, 983/// can be converted to the type ToType via a pointer conversion (C++ 984/// 4.10). If so, returns true and places the converted type (that 985/// might differ from ToType in its cv-qualifiers at some level) into 986/// ConvertedType. 987/// 988/// This routine also supports conversions to and from block pointers 989/// and conversions with Objective-C's 'id', 'id<protocols...>', and 990/// pointers to interfaces. FIXME: Once we've determined the 991/// appropriate overloading rules for Objective-C, we may want to 992/// split the Objective-C checks into a different routine; however, 993/// GCC seems to consider all of these conversions to be pointer 994/// conversions, so for now they live here. IncompatibleObjC will be 995/// set if the conversion is an allowed Objective-C conversion that 996/// should result in a warning. 997bool Sema::IsPointerConversion(Expr *From, QualType FromType, QualType ToType, 998 bool InOverloadResolution, 999 QualType& ConvertedType, 1000 bool &IncompatibleObjC) { 1001 IncompatibleObjC = false; 1002 if (isObjCPointerConversion(FromType, ToType, ConvertedType, IncompatibleObjC)) 1003 return true; 1004 1005 // Conversion from a null pointer constant to any Objective-C pointer type. 1006 if (ToType->isObjCObjectPointerType() && 1007 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1008 ConvertedType = ToType; 1009 return true; 1010 } 1011 1012 // Blocks: Block pointers can be converted to void*. 1013 if (FromType->isBlockPointerType() && ToType->isPointerType() && 1014 ToType->getAs<PointerType>()->getPointeeType()->isVoidType()) { 1015 ConvertedType = ToType; 1016 return true; 1017 } 1018 // Blocks: A null pointer constant can be converted to a block 1019 // pointer type. 1020 if (ToType->isBlockPointerType() && 1021 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1022 ConvertedType = ToType; 1023 return true; 1024 } 1025 1026 // If the left-hand-side is nullptr_t, the right side can be a null 1027 // pointer constant. 1028 if (ToType->isNullPtrType() && 1029 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1030 ConvertedType = ToType; 1031 return true; 1032 } 1033 1034 const PointerType* ToTypePtr = ToType->getAs<PointerType>(); 1035 if (!ToTypePtr) 1036 return false; 1037 1038 // A null pointer constant can be converted to a pointer type (C++ 4.10p1). 1039 if (isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1040 ConvertedType = ToType; 1041 return true; 1042 } 1043 1044 // Beyond this point, both types need to be pointers 1045 // , including objective-c pointers. 1046 QualType ToPointeeType = ToTypePtr->getPointeeType(); 1047 if (FromType->isObjCObjectPointerType() && ToPointeeType->isVoidType()) { 1048 ConvertedType = BuildSimilarlyQualifiedObjCObjectPointerType(FromType, 1049 ToType, Context); 1050 return true; 1051 1052 } 1053 const PointerType *FromTypePtr = FromType->getAs<PointerType>(); 1054 if (!FromTypePtr) 1055 return false; 1056 1057 QualType FromPointeeType = FromTypePtr->getPointeeType(); 1058 1059 // An rvalue of type "pointer to cv T," where T is an object type, 1060 // can be converted to an rvalue of type "pointer to cv void" (C++ 1061 // 4.10p2). 1062 if (FromPointeeType->isObjectType() && ToPointeeType->isVoidType()) { 1063 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1064 ToPointeeType, 1065 ToType, Context); 1066 return true; 1067 } 1068 1069 // When we're overloading in C, we allow a special kind of pointer 1070 // conversion for compatible-but-not-identical pointee types. 1071 if (!getLangOptions().CPlusPlus && 1072 Context.typesAreCompatible(FromPointeeType, ToPointeeType)) { 1073 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1074 ToPointeeType, 1075 ToType, Context); 1076 return true; 1077 } 1078 1079 // C++ [conv.ptr]p3: 1080 // 1081 // An rvalue of type "pointer to cv D," where D is a class type, 1082 // can be converted to an rvalue of type "pointer to cv B," where 1083 // B is a base class (clause 10) of D. If B is an inaccessible 1084 // (clause 11) or ambiguous (10.2) base class of D, a program that 1085 // necessitates this conversion is ill-formed. The result of the 1086 // conversion is a pointer to the base class sub-object of the 1087 // derived class object. The null pointer value is converted to 1088 // the null pointer value of the destination type. 1089 // 1090 // Note that we do not check for ambiguity or inaccessibility 1091 // here. That is handled by CheckPointerConversion. 1092 if (getLangOptions().CPlusPlus && 1093 FromPointeeType->isRecordType() && ToPointeeType->isRecordType() && 1094 !Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType) && 1095 !RequireCompleteType(From->getLocStart(), FromPointeeType, PDiag()) && 1096 IsDerivedFrom(FromPointeeType, ToPointeeType)) { 1097 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1098 ToPointeeType, 1099 ToType, Context); 1100 return true; 1101 } 1102 1103 return false; 1104} 1105 1106/// isObjCPointerConversion - Determines whether this is an 1107/// Objective-C pointer conversion. Subroutine of IsPointerConversion, 1108/// with the same arguments and return values. 1109bool Sema::isObjCPointerConversion(QualType FromType, QualType ToType, 1110 QualType& ConvertedType, 1111 bool &IncompatibleObjC) { 1112 if (!getLangOptions().ObjC1) 1113 return false; 1114 1115 // First, we handle all conversions on ObjC object pointer types. 1116 const ObjCObjectPointerType* ToObjCPtr = ToType->getAs<ObjCObjectPointerType>(); 1117 const ObjCObjectPointerType *FromObjCPtr = 1118 FromType->getAs<ObjCObjectPointerType>(); 1119 1120 if (ToObjCPtr && FromObjCPtr) { 1121 // Objective C++: We're able to convert between "id" or "Class" and a 1122 // pointer to any interface (in both directions). 1123 if (ToObjCPtr->isObjCBuiltinType() && FromObjCPtr->isObjCBuiltinType()) { 1124 ConvertedType = ToType; 1125 return true; 1126 } 1127 // Conversions with Objective-C's id<...>. 1128 if ((FromObjCPtr->isObjCQualifiedIdType() || 1129 ToObjCPtr->isObjCQualifiedIdType()) && 1130 Context.ObjCQualifiedIdTypesAreCompatible(ToType, FromType, 1131 /*compare=*/false)) { 1132 ConvertedType = ToType; 1133 return true; 1134 } 1135 // Objective C++: We're able to convert from a pointer to an 1136 // interface to a pointer to a different interface. 1137 if (Context.canAssignObjCInterfaces(ToObjCPtr, FromObjCPtr)) { 1138 const ObjCInterfaceType* LHS = ToObjCPtr->getInterfaceType(); 1139 const ObjCInterfaceType* RHS = FromObjCPtr->getInterfaceType(); 1140 if (getLangOptions().CPlusPlus && LHS && RHS && 1141 !ToObjCPtr->getPointeeType().isAtLeastAsQualifiedAs( 1142 FromObjCPtr->getPointeeType())) 1143 return false; 1144 ConvertedType = ToType; 1145 return true; 1146 } 1147 1148 if (Context.canAssignObjCInterfaces(FromObjCPtr, ToObjCPtr)) { 1149 // Okay: this is some kind of implicit downcast of Objective-C 1150 // interfaces, which is permitted. However, we're going to 1151 // complain about it. 1152 IncompatibleObjC = true; 1153 ConvertedType = FromType; 1154 return true; 1155 } 1156 } 1157 // Beyond this point, both types need to be C pointers or block pointers. 1158 QualType ToPointeeType; 1159 if (const PointerType *ToCPtr = ToType->getAs<PointerType>()) 1160 ToPointeeType = ToCPtr->getPointeeType(); 1161 else if (const BlockPointerType *ToBlockPtr = 1162 ToType->getAs<BlockPointerType>()) { 1163 // Objective C++: We're able to convert from a pointer to any object 1164 // to a block pointer type. 1165 if (FromObjCPtr && FromObjCPtr->isObjCBuiltinType()) { 1166 ConvertedType = ToType; 1167 return true; 1168 } 1169 ToPointeeType = ToBlockPtr->getPointeeType(); 1170 } 1171 else if (FromType->getAs<BlockPointerType>() && 1172 ToObjCPtr && ToObjCPtr->isObjCBuiltinType()) { 1173 // Objective C++: We're able to convert from a block pointer type to a 1174 // pointer to any object. 1175 ConvertedType = ToType; 1176 return true; 1177 } 1178 else 1179 return false; 1180 1181 QualType FromPointeeType; 1182 if (const PointerType *FromCPtr = FromType->getAs<PointerType>()) 1183 FromPointeeType = FromCPtr->getPointeeType(); 1184 else if (const BlockPointerType *FromBlockPtr = FromType->getAs<BlockPointerType>()) 1185 FromPointeeType = FromBlockPtr->getPointeeType(); 1186 else 1187 return false; 1188 1189 // If we have pointers to pointers, recursively check whether this 1190 // is an Objective-C conversion. 1191 if (FromPointeeType->isPointerType() && ToPointeeType->isPointerType() && 1192 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, 1193 IncompatibleObjC)) { 1194 // We always complain about this conversion. 1195 IncompatibleObjC = true; 1196 ConvertedType = ToType; 1197 return true; 1198 } 1199 // Allow conversion of pointee being objective-c pointer to another one; 1200 // as in I* to id. 1201 if (FromPointeeType->getAs<ObjCObjectPointerType>() && 1202 ToPointeeType->getAs<ObjCObjectPointerType>() && 1203 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, 1204 IncompatibleObjC)) { 1205 ConvertedType = ToType; 1206 return true; 1207 } 1208 1209 // If we have pointers to functions or blocks, check whether the only 1210 // differences in the argument and result types are in Objective-C 1211 // pointer conversions. If so, we permit the conversion (but 1212 // complain about it). 1213 const FunctionProtoType *FromFunctionType 1214 = FromPointeeType->getAs<FunctionProtoType>(); 1215 const FunctionProtoType *ToFunctionType 1216 = ToPointeeType->getAs<FunctionProtoType>(); 1217 if (FromFunctionType && ToFunctionType) { 1218 // If the function types are exactly the same, this isn't an 1219 // Objective-C pointer conversion. 1220 if (Context.getCanonicalType(FromPointeeType) 1221 == Context.getCanonicalType(ToPointeeType)) 1222 return false; 1223 1224 // Perform the quick checks that will tell us whether these 1225 // function types are obviously different. 1226 if (FromFunctionType->getNumArgs() != ToFunctionType->getNumArgs() || 1227 FromFunctionType->isVariadic() != ToFunctionType->isVariadic() || 1228 FromFunctionType->getTypeQuals() != ToFunctionType->getTypeQuals()) 1229 return false; 1230 1231 bool HasObjCConversion = false; 1232 if (Context.getCanonicalType(FromFunctionType->getResultType()) 1233 == Context.getCanonicalType(ToFunctionType->getResultType())) { 1234 // Okay, the types match exactly. Nothing to do. 1235 } else if (isObjCPointerConversion(FromFunctionType->getResultType(), 1236 ToFunctionType->getResultType(), 1237 ConvertedType, IncompatibleObjC)) { 1238 // Okay, we have an Objective-C pointer conversion. 1239 HasObjCConversion = true; 1240 } else { 1241 // Function types are too different. Abort. 1242 return false; 1243 } 1244 1245 // Check argument types. 1246 for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumArgs(); 1247 ArgIdx != NumArgs; ++ArgIdx) { 1248 QualType FromArgType = FromFunctionType->getArgType(ArgIdx); 1249 QualType ToArgType = ToFunctionType->getArgType(ArgIdx); 1250 if (Context.getCanonicalType(FromArgType) 1251 == Context.getCanonicalType(ToArgType)) { 1252 // Okay, the types match exactly. Nothing to do. 1253 } else if (isObjCPointerConversion(FromArgType, ToArgType, 1254 ConvertedType, IncompatibleObjC)) { 1255 // Okay, we have an Objective-C pointer conversion. 1256 HasObjCConversion = true; 1257 } else { 1258 // Argument types are too different. Abort. 1259 return false; 1260 } 1261 } 1262 1263 if (HasObjCConversion) { 1264 // We had an Objective-C conversion. Allow this pointer 1265 // conversion, but complain about it. 1266 ConvertedType = ToType; 1267 IncompatibleObjC = true; 1268 return true; 1269 } 1270 } 1271 1272 return false; 1273} 1274 1275/// CheckPointerConversion - Check the pointer conversion from the 1276/// expression From to the type ToType. This routine checks for 1277/// ambiguous or inaccessible derived-to-base pointer 1278/// conversions for which IsPointerConversion has already returned 1279/// true. It returns true and produces a diagnostic if there was an 1280/// error, or returns false otherwise. 1281bool Sema::CheckPointerConversion(Expr *From, QualType ToType, 1282 CastExpr::CastKind &Kind, 1283 bool IgnoreBaseAccess) { 1284 QualType FromType = From->getType(); 1285 1286 if (const PointerType *FromPtrType = FromType->getAs<PointerType>()) 1287 if (const PointerType *ToPtrType = ToType->getAs<PointerType>()) { 1288 QualType FromPointeeType = FromPtrType->getPointeeType(), 1289 ToPointeeType = ToPtrType->getPointeeType(); 1290 1291 if (FromPointeeType->isRecordType() && ToPointeeType->isRecordType() && 1292 !Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType)) { 1293 // We must have a derived-to-base conversion. Check an 1294 // ambiguous or inaccessible conversion. 1295 if (CheckDerivedToBaseConversion(FromPointeeType, ToPointeeType, 1296 From->getExprLoc(), 1297 From->getSourceRange(), 1298 IgnoreBaseAccess)) 1299 return true; 1300 1301 // The conversion was successful. 1302 Kind = CastExpr::CK_DerivedToBase; 1303 } 1304 } 1305 if (const ObjCObjectPointerType *FromPtrType = 1306 FromType->getAs<ObjCObjectPointerType>()) 1307 if (const ObjCObjectPointerType *ToPtrType = 1308 ToType->getAs<ObjCObjectPointerType>()) { 1309 // Objective-C++ conversions are always okay. 1310 // FIXME: We should have a different class of conversions for the 1311 // Objective-C++ implicit conversions. 1312 if (FromPtrType->isObjCBuiltinType() || ToPtrType->isObjCBuiltinType()) 1313 return false; 1314 1315 } 1316 return false; 1317} 1318 1319/// IsMemberPointerConversion - Determines whether the conversion of the 1320/// expression From, which has the (possibly adjusted) type FromType, can be 1321/// converted to the type ToType via a member pointer conversion (C++ 4.11). 1322/// If so, returns true and places the converted type (that might differ from 1323/// ToType in its cv-qualifiers at some level) into ConvertedType. 1324bool Sema::IsMemberPointerConversion(Expr *From, QualType FromType, 1325 QualType ToType, 1326 bool InOverloadResolution, 1327 QualType &ConvertedType) { 1328 const MemberPointerType *ToTypePtr = ToType->getAs<MemberPointerType>(); 1329 if (!ToTypePtr) 1330 return false; 1331 1332 // A null pointer constant can be converted to a member pointer (C++ 4.11p1) 1333 if (From->isNullPointerConstant(Context, 1334 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull 1335 : Expr::NPC_ValueDependentIsNull)) { 1336 ConvertedType = ToType; 1337 return true; 1338 } 1339 1340 // Otherwise, both types have to be member pointers. 1341 const MemberPointerType *FromTypePtr = FromType->getAs<MemberPointerType>(); 1342 if (!FromTypePtr) 1343 return false; 1344 1345 // A pointer to member of B can be converted to a pointer to member of D, 1346 // where D is derived from B (C++ 4.11p2). 1347 QualType FromClass(FromTypePtr->getClass(), 0); 1348 QualType ToClass(ToTypePtr->getClass(), 0); 1349 // FIXME: What happens when these are dependent? Is this function even called? 1350 1351 if (IsDerivedFrom(ToClass, FromClass)) { 1352 ConvertedType = Context.getMemberPointerType(FromTypePtr->getPointeeType(), 1353 ToClass.getTypePtr()); 1354 return true; 1355 } 1356 1357 return false; 1358} 1359 1360/// CheckMemberPointerConversion - Check the member pointer conversion from the 1361/// expression From to the type ToType. This routine checks for ambiguous or 1362/// virtual or inaccessible base-to-derived member pointer conversions 1363/// for which IsMemberPointerConversion has already returned true. It returns 1364/// true and produces a diagnostic if there was an error, or returns false 1365/// otherwise. 1366bool Sema::CheckMemberPointerConversion(Expr *From, QualType ToType, 1367 CastExpr::CastKind &Kind, 1368 bool IgnoreBaseAccess) { 1369 QualType FromType = From->getType(); 1370 const MemberPointerType *FromPtrType = FromType->getAs<MemberPointerType>(); 1371 if (!FromPtrType) { 1372 // This must be a null pointer to member pointer conversion 1373 assert(From->isNullPointerConstant(Context, 1374 Expr::NPC_ValueDependentIsNull) && 1375 "Expr must be null pointer constant!"); 1376 Kind = CastExpr::CK_NullToMemberPointer; 1377 return false; 1378 } 1379 1380 const MemberPointerType *ToPtrType = ToType->getAs<MemberPointerType>(); 1381 assert(ToPtrType && "No member pointer cast has a target type " 1382 "that is not a member pointer."); 1383 1384 QualType FromClass = QualType(FromPtrType->getClass(), 0); 1385 QualType ToClass = QualType(ToPtrType->getClass(), 0); 1386 1387 // FIXME: What about dependent types? 1388 assert(FromClass->isRecordType() && "Pointer into non-class."); 1389 assert(ToClass->isRecordType() && "Pointer into non-class."); 1390 1391 CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/ true, 1392 /*DetectVirtual=*/true); 1393 bool DerivationOkay = IsDerivedFrom(ToClass, FromClass, Paths); 1394 assert(DerivationOkay && 1395 "Should not have been called if derivation isn't OK."); 1396 (void)DerivationOkay; 1397 1398 if (Paths.isAmbiguous(Context.getCanonicalType(FromClass). 1399 getUnqualifiedType())) { 1400 std::string PathDisplayStr = getAmbiguousPathsDisplayString(Paths); 1401 Diag(From->getExprLoc(), diag::err_ambiguous_memptr_conv) 1402 << 0 << FromClass << ToClass << PathDisplayStr << From->getSourceRange(); 1403 return true; 1404 } 1405 1406 if (const RecordType *VBase = Paths.getDetectedVirtual()) { 1407 Diag(From->getExprLoc(), diag::err_memptr_conv_via_virtual) 1408 << FromClass << ToClass << QualType(VBase, 0) 1409 << From->getSourceRange(); 1410 return true; 1411 } 1412 1413 if (!IgnoreBaseAccess) 1414 CheckBaseClassAccess(From->getExprLoc(), FromClass, ToClass, 1415 Paths.front(), 1416 diag::err_downcast_from_inaccessible_base); 1417 1418 // Must be a base to derived member conversion. 1419 Kind = CastExpr::CK_BaseToDerivedMemberPointer; 1420 return false; 1421} 1422 1423/// IsQualificationConversion - Determines whether the conversion from 1424/// an rvalue of type FromType to ToType is a qualification conversion 1425/// (C++ 4.4). 1426bool 1427Sema::IsQualificationConversion(QualType FromType, QualType ToType) { 1428 FromType = Context.getCanonicalType(FromType); 1429 ToType = Context.getCanonicalType(ToType); 1430 1431 // If FromType and ToType are the same type, this is not a 1432 // qualification conversion. 1433 if (FromType.getUnqualifiedType() == ToType.getUnqualifiedType()) 1434 return false; 1435 1436 // (C++ 4.4p4): 1437 // A conversion can add cv-qualifiers at levels other than the first 1438 // in multi-level pointers, subject to the following rules: [...] 1439 bool PreviousToQualsIncludeConst = true; 1440 bool UnwrappedAnyPointer = false; 1441 while (UnwrapSimilarPointerTypes(FromType, ToType)) { 1442 // Within each iteration of the loop, we check the qualifiers to 1443 // determine if this still looks like a qualification 1444 // conversion. Then, if all is well, we unwrap one more level of 1445 // pointers or pointers-to-members and do it all again 1446 // until there are no more pointers or pointers-to-members left to 1447 // unwrap. 1448 UnwrappedAnyPointer = true; 1449 1450 // -- for every j > 0, if const is in cv 1,j then const is in cv 1451 // 2,j, and similarly for volatile. 1452 if (!ToType.isAtLeastAsQualifiedAs(FromType)) 1453 return false; 1454 1455 // -- if the cv 1,j and cv 2,j are different, then const is in 1456 // every cv for 0 < k < j. 1457 if (FromType.getCVRQualifiers() != ToType.getCVRQualifiers() 1458 && !PreviousToQualsIncludeConst) 1459 return false; 1460 1461 // Keep track of whether all prior cv-qualifiers in the "to" type 1462 // include const. 1463 PreviousToQualsIncludeConst 1464 = PreviousToQualsIncludeConst && ToType.isConstQualified(); 1465 } 1466 1467 // We are left with FromType and ToType being the pointee types 1468 // after unwrapping the original FromType and ToType the same number 1469 // of types. If we unwrapped any pointers, and if FromType and 1470 // ToType have the same unqualified type (since we checked 1471 // qualifiers above), then this is a qualification conversion. 1472 return UnwrappedAnyPointer && Context.hasSameUnqualifiedType(FromType,ToType); 1473} 1474 1475/// Determines whether there is a user-defined conversion sequence 1476/// (C++ [over.ics.user]) that converts expression From to the type 1477/// ToType. If such a conversion exists, User will contain the 1478/// user-defined conversion sequence that performs such a conversion 1479/// and this routine will return true. Otherwise, this routine returns 1480/// false and User is unspecified. 1481/// 1482/// \param AllowConversionFunctions true if the conversion should 1483/// consider conversion functions at all. If false, only constructors 1484/// will be considered. 1485/// 1486/// \param AllowExplicit true if the conversion should consider C++0x 1487/// "explicit" conversion functions as well as non-explicit conversion 1488/// functions (C++0x [class.conv.fct]p2). 1489/// 1490/// \param ForceRValue true if the expression should be treated as an rvalue 1491/// for overload resolution. 1492/// \param UserCast true if looking for user defined conversion for a static 1493/// cast. 1494OverloadingResult Sema::IsUserDefinedConversion(Expr *From, QualType ToType, 1495 UserDefinedConversionSequence& User, 1496 OverloadCandidateSet& CandidateSet, 1497 bool AllowConversionFunctions, 1498 bool AllowExplicit, 1499 bool ForceRValue, 1500 bool UserCast) { 1501 if (const RecordType *ToRecordType = ToType->getAs<RecordType>()) { 1502 if (RequireCompleteType(From->getLocStart(), ToType, PDiag())) { 1503 // We're not going to find any constructors. 1504 } else if (CXXRecordDecl *ToRecordDecl 1505 = dyn_cast<CXXRecordDecl>(ToRecordType->getDecl())) { 1506 // C++ [over.match.ctor]p1: 1507 // When objects of class type are direct-initialized (8.5), or 1508 // copy-initialized from an expression of the same or a 1509 // derived class type (8.5), overload resolution selects the 1510 // constructor. [...] For copy-initialization, the candidate 1511 // functions are all the converting constructors (12.3.1) of 1512 // that class. The argument list is the expression-list within 1513 // the parentheses of the initializer. 1514 bool SuppressUserConversions = !UserCast; 1515 if (Context.hasSameUnqualifiedType(ToType, From->getType()) || 1516 IsDerivedFrom(From->getType(), ToType)) { 1517 SuppressUserConversions = false; 1518 AllowConversionFunctions = false; 1519 } 1520 1521 DeclarationName ConstructorName 1522 = Context.DeclarationNames.getCXXConstructorName( 1523 Context.getCanonicalType(ToType).getUnqualifiedType()); 1524 DeclContext::lookup_iterator Con, ConEnd; 1525 for (llvm::tie(Con, ConEnd) 1526 = ToRecordDecl->lookup(ConstructorName); 1527 Con != ConEnd; ++Con) { 1528 NamedDecl *D = *Con; 1529 DeclAccessPair FoundDecl = DeclAccessPair::make(D, D->getAccess()); 1530 1531 // Find the constructor (which may be a template). 1532 CXXConstructorDecl *Constructor = 0; 1533 FunctionTemplateDecl *ConstructorTmpl 1534 = dyn_cast<FunctionTemplateDecl>(D); 1535 if (ConstructorTmpl) 1536 Constructor 1537 = cast<CXXConstructorDecl>(ConstructorTmpl->getTemplatedDecl()); 1538 else 1539 Constructor = cast<CXXConstructorDecl>(D); 1540 1541 if (!Constructor->isInvalidDecl() && 1542 Constructor->isConvertingConstructor(AllowExplicit)) { 1543 if (ConstructorTmpl) 1544 AddTemplateOverloadCandidate(ConstructorTmpl, FoundDecl, 1545 /*ExplicitArgs*/ 0, 1546 &From, 1, CandidateSet, 1547 SuppressUserConversions, ForceRValue); 1548 else 1549 // Allow one user-defined conversion when user specifies a 1550 // From->ToType conversion via an static cast (c-style, etc). 1551 AddOverloadCandidate(Constructor, FoundDecl, 1552 &From, 1, CandidateSet, 1553 SuppressUserConversions, ForceRValue); 1554 } 1555 } 1556 } 1557 } 1558 1559 if (!AllowConversionFunctions) { 1560 // Don't allow any conversion functions to enter the overload set. 1561 } else if (RequireCompleteType(From->getLocStart(), From->getType(), 1562 PDiag(0) 1563 << From->getSourceRange())) { 1564 // No conversion functions from incomplete types. 1565 } else if (const RecordType *FromRecordType 1566 = From->getType()->getAs<RecordType>()) { 1567 if (CXXRecordDecl *FromRecordDecl 1568 = dyn_cast<CXXRecordDecl>(FromRecordType->getDecl())) { 1569 // Add all of the conversion functions as candidates. 1570 const UnresolvedSetImpl *Conversions 1571 = FromRecordDecl->getVisibleConversionFunctions(); 1572 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 1573 E = Conversions->end(); I != E; ++I) { 1574 DeclAccessPair FoundDecl = I.getPair(); 1575 NamedDecl *D = FoundDecl.getDecl(); 1576 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext()); 1577 if (isa<UsingShadowDecl>(D)) 1578 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 1579 1580 CXXConversionDecl *Conv; 1581 FunctionTemplateDecl *ConvTemplate; 1582 if ((ConvTemplate = dyn_cast<FunctionTemplateDecl>(*I))) 1583 Conv = dyn_cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 1584 else 1585 Conv = dyn_cast<CXXConversionDecl>(*I); 1586 1587 if (AllowExplicit || !Conv->isExplicit()) { 1588 if (ConvTemplate) 1589 AddTemplateConversionCandidate(ConvTemplate, FoundDecl, 1590 ActingContext, From, ToType, 1591 CandidateSet); 1592 else 1593 AddConversionCandidate(Conv, FoundDecl, ActingContext, 1594 From, ToType, CandidateSet); 1595 } 1596 } 1597 } 1598 } 1599 1600 OverloadCandidateSet::iterator Best; 1601 switch (BestViableFunction(CandidateSet, From->getLocStart(), Best)) { 1602 case OR_Success: 1603 // Record the standard conversion we used and the conversion function. 1604 if (CXXConstructorDecl *Constructor 1605 = dyn_cast<CXXConstructorDecl>(Best->Function)) { 1606 // C++ [over.ics.user]p1: 1607 // If the user-defined conversion is specified by a 1608 // constructor (12.3.1), the initial standard conversion 1609 // sequence converts the source type to the type required by 1610 // the argument of the constructor. 1611 // 1612 QualType ThisType = Constructor->getThisType(Context); 1613 if (Best->Conversions[0].isEllipsis()) 1614 User.EllipsisConversion = true; 1615 else { 1616 User.Before = Best->Conversions[0].Standard; 1617 User.EllipsisConversion = false; 1618 } 1619 User.ConversionFunction = Constructor; 1620 User.After.setAsIdentityConversion(); 1621 User.After.setFromType( 1622 ThisType->getAs<PointerType>()->getPointeeType()); 1623 User.After.setAllToTypes(ToType); 1624 return OR_Success; 1625 } else if (CXXConversionDecl *Conversion 1626 = dyn_cast<CXXConversionDecl>(Best->Function)) { 1627 // C++ [over.ics.user]p1: 1628 // 1629 // [...] If the user-defined conversion is specified by a 1630 // conversion function (12.3.2), the initial standard 1631 // conversion sequence converts the source type to the 1632 // implicit object parameter of the conversion function. 1633 User.Before = Best->Conversions[0].Standard; 1634 User.ConversionFunction = Conversion; 1635 User.EllipsisConversion = false; 1636 1637 // C++ [over.ics.user]p2: 1638 // The second standard conversion sequence converts the 1639 // result of the user-defined conversion to the target type 1640 // for the sequence. Since an implicit conversion sequence 1641 // is an initialization, the special rules for 1642 // initialization by user-defined conversion apply when 1643 // selecting the best user-defined conversion for a 1644 // user-defined conversion sequence (see 13.3.3 and 1645 // 13.3.3.1). 1646 User.After = Best->FinalConversion; 1647 return OR_Success; 1648 } else { 1649 assert(false && "Not a constructor or conversion function?"); 1650 return OR_No_Viable_Function; 1651 } 1652 1653 case OR_No_Viable_Function: 1654 return OR_No_Viable_Function; 1655 case OR_Deleted: 1656 // No conversion here! We're done. 1657 return OR_Deleted; 1658 1659 case OR_Ambiguous: 1660 return OR_Ambiguous; 1661 } 1662 1663 return OR_No_Viable_Function; 1664} 1665 1666bool 1667Sema::DiagnoseMultipleUserDefinedConversion(Expr *From, QualType ToType) { 1668 ImplicitConversionSequence ICS; 1669 OverloadCandidateSet CandidateSet(From->getExprLoc()); 1670 OverloadingResult OvResult = 1671 IsUserDefinedConversion(From, ToType, ICS.UserDefined, 1672 CandidateSet, true, false, false); 1673 if (OvResult == OR_Ambiguous) 1674 Diag(From->getSourceRange().getBegin(), 1675 diag::err_typecheck_ambiguous_condition) 1676 << From->getType() << ToType << From->getSourceRange(); 1677 else if (OvResult == OR_No_Viable_Function && !CandidateSet.empty()) 1678 Diag(From->getSourceRange().getBegin(), 1679 diag::err_typecheck_nonviable_condition) 1680 << From->getType() << ToType << From->getSourceRange(); 1681 else 1682 return false; 1683 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, &From, 1); 1684 return true; 1685} 1686 1687/// CompareImplicitConversionSequences - Compare two implicit 1688/// conversion sequences to determine whether one is better than the 1689/// other or if they are indistinguishable (C++ 13.3.3.2). 1690ImplicitConversionSequence::CompareKind 1691Sema::CompareImplicitConversionSequences(const ImplicitConversionSequence& ICS1, 1692 const ImplicitConversionSequence& ICS2) 1693{ 1694 // (C++ 13.3.3.2p2): When comparing the basic forms of implicit 1695 // conversion sequences (as defined in 13.3.3.1) 1696 // -- a standard conversion sequence (13.3.3.1.1) is a better 1697 // conversion sequence than a user-defined conversion sequence or 1698 // an ellipsis conversion sequence, and 1699 // -- a user-defined conversion sequence (13.3.3.1.2) is a better 1700 // conversion sequence than an ellipsis conversion sequence 1701 // (13.3.3.1.3). 1702 // 1703 // C++0x [over.best.ics]p10: 1704 // For the purpose of ranking implicit conversion sequences as 1705 // described in 13.3.3.2, the ambiguous conversion sequence is 1706 // treated as a user-defined sequence that is indistinguishable 1707 // from any other user-defined conversion sequence. 1708 if (ICS1.getKind() < ICS2.getKind()) { 1709 if (!(ICS1.isUserDefined() && ICS2.isAmbiguous())) 1710 return ImplicitConversionSequence::Better; 1711 } else if (ICS2.getKind() < ICS1.getKind()) { 1712 if (!(ICS2.isUserDefined() && ICS1.isAmbiguous())) 1713 return ImplicitConversionSequence::Worse; 1714 } 1715 1716 if (ICS1.isAmbiguous() || ICS2.isAmbiguous()) 1717 return ImplicitConversionSequence::Indistinguishable; 1718 1719 // Two implicit conversion sequences of the same form are 1720 // indistinguishable conversion sequences unless one of the 1721 // following rules apply: (C++ 13.3.3.2p3): 1722 if (ICS1.isStandard()) 1723 return CompareStandardConversionSequences(ICS1.Standard, ICS2.Standard); 1724 else if (ICS1.isUserDefined()) { 1725 // User-defined conversion sequence U1 is a better conversion 1726 // sequence than another user-defined conversion sequence U2 if 1727 // they contain the same user-defined conversion function or 1728 // constructor and if the second standard conversion sequence of 1729 // U1 is better than the second standard conversion sequence of 1730 // U2 (C++ 13.3.3.2p3). 1731 if (ICS1.UserDefined.ConversionFunction == 1732 ICS2.UserDefined.ConversionFunction) 1733 return CompareStandardConversionSequences(ICS1.UserDefined.After, 1734 ICS2.UserDefined.After); 1735 } 1736 1737 return ImplicitConversionSequence::Indistinguishable; 1738} 1739 1740// Per 13.3.3.2p3, compare the given standard conversion sequences to 1741// determine if one is a proper subset of the other. 1742static ImplicitConversionSequence::CompareKind 1743compareStandardConversionSubsets(ASTContext &Context, 1744 const StandardConversionSequence& SCS1, 1745 const StandardConversionSequence& SCS2) { 1746 ImplicitConversionSequence::CompareKind Result 1747 = ImplicitConversionSequence::Indistinguishable; 1748 1749 if (SCS1.Second != SCS2.Second) { 1750 if (SCS1.Second == ICK_Identity) 1751 Result = ImplicitConversionSequence::Better; 1752 else if (SCS2.Second == ICK_Identity) 1753 Result = ImplicitConversionSequence::Worse; 1754 else 1755 return ImplicitConversionSequence::Indistinguishable; 1756 } else if (!Context.hasSameType(SCS1.getToType(1), SCS2.getToType(1))) 1757 return ImplicitConversionSequence::Indistinguishable; 1758 1759 if (SCS1.Third == SCS2.Third) { 1760 return Context.hasSameType(SCS1.getToType(2), SCS2.getToType(2))? Result 1761 : ImplicitConversionSequence::Indistinguishable; 1762 } 1763 1764 if (SCS1.Third == ICK_Identity) 1765 return Result == ImplicitConversionSequence::Worse 1766 ? ImplicitConversionSequence::Indistinguishable 1767 : ImplicitConversionSequence::Better; 1768 1769 if (SCS2.Third == ICK_Identity) 1770 return Result == ImplicitConversionSequence::Better 1771 ? ImplicitConversionSequence::Indistinguishable 1772 : ImplicitConversionSequence::Worse; 1773 1774 return ImplicitConversionSequence::Indistinguishable; 1775} 1776 1777/// CompareStandardConversionSequences - Compare two standard 1778/// conversion sequences to determine whether one is better than the 1779/// other or if they are indistinguishable (C++ 13.3.3.2p3). 1780ImplicitConversionSequence::CompareKind 1781Sema::CompareStandardConversionSequences(const StandardConversionSequence& SCS1, 1782 const StandardConversionSequence& SCS2) 1783{ 1784 // Standard conversion sequence S1 is a better conversion sequence 1785 // than standard conversion sequence S2 if (C++ 13.3.3.2p3): 1786 1787 // -- S1 is a proper subsequence of S2 (comparing the conversion 1788 // sequences in the canonical form defined by 13.3.3.1.1, 1789 // excluding any Lvalue Transformation; the identity conversion 1790 // sequence is considered to be a subsequence of any 1791 // non-identity conversion sequence) or, if not that, 1792 if (ImplicitConversionSequence::CompareKind CK 1793 = compareStandardConversionSubsets(Context, SCS1, SCS2)) 1794 return CK; 1795 1796 // -- the rank of S1 is better than the rank of S2 (by the rules 1797 // defined below), or, if not that, 1798 ImplicitConversionRank Rank1 = SCS1.getRank(); 1799 ImplicitConversionRank Rank2 = SCS2.getRank(); 1800 if (Rank1 < Rank2) 1801 return ImplicitConversionSequence::Better; 1802 else if (Rank2 < Rank1) 1803 return ImplicitConversionSequence::Worse; 1804 1805 // (C++ 13.3.3.2p4): Two conversion sequences with the same rank 1806 // are indistinguishable unless one of the following rules 1807 // applies: 1808 1809 // A conversion that is not a conversion of a pointer, or 1810 // pointer to member, to bool is better than another conversion 1811 // that is such a conversion. 1812 if (SCS1.isPointerConversionToBool() != SCS2.isPointerConversionToBool()) 1813 return SCS2.isPointerConversionToBool() 1814 ? ImplicitConversionSequence::Better 1815 : ImplicitConversionSequence::Worse; 1816 1817 // C++ [over.ics.rank]p4b2: 1818 // 1819 // If class B is derived directly or indirectly from class A, 1820 // conversion of B* to A* is better than conversion of B* to 1821 // void*, and conversion of A* to void* is better than conversion 1822 // of B* to void*. 1823 bool SCS1ConvertsToVoid 1824 = SCS1.isPointerConversionToVoidPointer(Context); 1825 bool SCS2ConvertsToVoid 1826 = SCS2.isPointerConversionToVoidPointer(Context); 1827 if (SCS1ConvertsToVoid != SCS2ConvertsToVoid) { 1828 // Exactly one of the conversion sequences is a conversion to 1829 // a void pointer; it's the worse conversion. 1830 return SCS2ConvertsToVoid ? ImplicitConversionSequence::Better 1831 : ImplicitConversionSequence::Worse; 1832 } else if (!SCS1ConvertsToVoid && !SCS2ConvertsToVoid) { 1833 // Neither conversion sequence converts to a void pointer; compare 1834 // their derived-to-base conversions. 1835 if (ImplicitConversionSequence::CompareKind DerivedCK 1836 = CompareDerivedToBaseConversions(SCS1, SCS2)) 1837 return DerivedCK; 1838 } else if (SCS1ConvertsToVoid && SCS2ConvertsToVoid) { 1839 // Both conversion sequences are conversions to void 1840 // pointers. Compare the source types to determine if there's an 1841 // inheritance relationship in their sources. 1842 QualType FromType1 = SCS1.getFromType(); 1843 QualType FromType2 = SCS2.getFromType(); 1844 1845 // Adjust the types we're converting from via the array-to-pointer 1846 // conversion, if we need to. 1847 if (SCS1.First == ICK_Array_To_Pointer) 1848 FromType1 = Context.getArrayDecayedType(FromType1); 1849 if (SCS2.First == ICK_Array_To_Pointer) 1850 FromType2 = Context.getArrayDecayedType(FromType2); 1851 1852 QualType FromPointee1 1853 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1854 QualType FromPointee2 1855 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1856 1857 if (IsDerivedFrom(FromPointee2, FromPointee1)) 1858 return ImplicitConversionSequence::Better; 1859 else if (IsDerivedFrom(FromPointee1, FromPointee2)) 1860 return ImplicitConversionSequence::Worse; 1861 1862 // Objective-C++: If one interface is more specific than the 1863 // other, it is the better one. 1864 const ObjCInterfaceType* FromIface1 = FromPointee1->getAs<ObjCInterfaceType>(); 1865 const ObjCInterfaceType* FromIface2 = FromPointee2->getAs<ObjCInterfaceType>(); 1866 if (FromIface1 && FromIface1) { 1867 if (Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 1868 return ImplicitConversionSequence::Better; 1869 else if (Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 1870 return ImplicitConversionSequence::Worse; 1871 } 1872 } 1873 1874 // Compare based on qualification conversions (C++ 13.3.3.2p3, 1875 // bullet 3). 1876 if (ImplicitConversionSequence::CompareKind QualCK 1877 = CompareQualificationConversions(SCS1, SCS2)) 1878 return QualCK; 1879 1880 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding) { 1881 // C++0x [over.ics.rank]p3b4: 1882 // -- S1 and S2 are reference bindings (8.5.3) and neither refers to an 1883 // implicit object parameter of a non-static member function declared 1884 // without a ref-qualifier, and S1 binds an rvalue reference to an 1885 // rvalue and S2 binds an lvalue reference. 1886 // FIXME: We don't know if we're dealing with the implicit object parameter, 1887 // or if the member function in this case has a ref qualifier. 1888 // (Of course, we don't have ref qualifiers yet.) 1889 if (SCS1.RRefBinding != SCS2.RRefBinding) 1890 return SCS1.RRefBinding ? ImplicitConversionSequence::Better 1891 : ImplicitConversionSequence::Worse; 1892 1893 // C++ [over.ics.rank]p3b4: 1894 // -- S1 and S2 are reference bindings (8.5.3), and the types to 1895 // which the references refer are the same type except for 1896 // top-level cv-qualifiers, and the type to which the reference 1897 // initialized by S2 refers is more cv-qualified than the type 1898 // to which the reference initialized by S1 refers. 1899 QualType T1 = SCS1.getToType(2); 1900 QualType T2 = SCS2.getToType(2); 1901 T1 = Context.getCanonicalType(T1); 1902 T2 = Context.getCanonicalType(T2); 1903 Qualifiers T1Quals, T2Quals; 1904 QualType UnqualT1 = Context.getUnqualifiedArrayType(T1, T1Quals); 1905 QualType UnqualT2 = Context.getUnqualifiedArrayType(T2, T2Quals); 1906 if (UnqualT1 == UnqualT2) { 1907 // If the type is an array type, promote the element qualifiers to the type 1908 // for comparison. 1909 if (isa<ArrayType>(T1) && T1Quals) 1910 T1 = Context.getQualifiedType(UnqualT1, T1Quals); 1911 if (isa<ArrayType>(T2) && T2Quals) 1912 T2 = Context.getQualifiedType(UnqualT2, T2Quals); 1913 if (T2.isMoreQualifiedThan(T1)) 1914 return ImplicitConversionSequence::Better; 1915 else if (T1.isMoreQualifiedThan(T2)) 1916 return ImplicitConversionSequence::Worse; 1917 } 1918 } 1919 1920 return ImplicitConversionSequence::Indistinguishable; 1921} 1922 1923/// CompareQualificationConversions - Compares two standard conversion 1924/// sequences to determine whether they can be ranked based on their 1925/// qualification conversions (C++ 13.3.3.2p3 bullet 3). 1926ImplicitConversionSequence::CompareKind 1927Sema::CompareQualificationConversions(const StandardConversionSequence& SCS1, 1928 const StandardConversionSequence& SCS2) { 1929 // C++ 13.3.3.2p3: 1930 // -- S1 and S2 differ only in their qualification conversion and 1931 // yield similar types T1 and T2 (C++ 4.4), respectively, and the 1932 // cv-qualification signature of type T1 is a proper subset of 1933 // the cv-qualification signature of type T2, and S1 is not the 1934 // deprecated string literal array-to-pointer conversion (4.2). 1935 if (SCS1.First != SCS2.First || SCS1.Second != SCS2.Second || 1936 SCS1.Third != SCS2.Third || SCS1.Third != ICK_Qualification) 1937 return ImplicitConversionSequence::Indistinguishable; 1938 1939 // FIXME: the example in the standard doesn't use a qualification 1940 // conversion (!) 1941 QualType T1 = SCS1.getToType(2); 1942 QualType T2 = SCS2.getToType(2); 1943 T1 = Context.getCanonicalType(T1); 1944 T2 = Context.getCanonicalType(T2); 1945 Qualifiers T1Quals, T2Quals; 1946 QualType UnqualT1 = Context.getUnqualifiedArrayType(T1, T1Quals); 1947 QualType UnqualT2 = Context.getUnqualifiedArrayType(T2, T2Quals); 1948 1949 // If the types are the same, we won't learn anything by unwrapped 1950 // them. 1951 if (UnqualT1 == UnqualT2) 1952 return ImplicitConversionSequence::Indistinguishable; 1953 1954 // If the type is an array type, promote the element qualifiers to the type 1955 // for comparison. 1956 if (isa<ArrayType>(T1) && T1Quals) 1957 T1 = Context.getQualifiedType(UnqualT1, T1Quals); 1958 if (isa<ArrayType>(T2) && T2Quals) 1959 T2 = Context.getQualifiedType(UnqualT2, T2Quals); 1960 1961 ImplicitConversionSequence::CompareKind Result 1962 = ImplicitConversionSequence::Indistinguishable; 1963 while (UnwrapSimilarPointerTypes(T1, T2)) { 1964 // Within each iteration of the loop, we check the qualifiers to 1965 // determine if this still looks like a qualification 1966 // conversion. Then, if all is well, we unwrap one more level of 1967 // pointers or pointers-to-members and do it all again 1968 // until there are no more pointers or pointers-to-members left 1969 // to unwrap. This essentially mimics what 1970 // IsQualificationConversion does, but here we're checking for a 1971 // strict subset of qualifiers. 1972 if (T1.getCVRQualifiers() == T2.getCVRQualifiers()) 1973 // The qualifiers are the same, so this doesn't tell us anything 1974 // about how the sequences rank. 1975 ; 1976 else if (T2.isMoreQualifiedThan(T1)) { 1977 // T1 has fewer qualifiers, so it could be the better sequence. 1978 if (Result == ImplicitConversionSequence::Worse) 1979 // Neither has qualifiers that are a subset of the other's 1980 // qualifiers. 1981 return ImplicitConversionSequence::Indistinguishable; 1982 1983 Result = ImplicitConversionSequence::Better; 1984 } else if (T1.isMoreQualifiedThan(T2)) { 1985 // T2 has fewer qualifiers, so it could be the better sequence. 1986 if (Result == ImplicitConversionSequence::Better) 1987 // Neither has qualifiers that are a subset of the other's 1988 // qualifiers. 1989 return ImplicitConversionSequence::Indistinguishable; 1990 1991 Result = ImplicitConversionSequence::Worse; 1992 } else { 1993 // Qualifiers are disjoint. 1994 return ImplicitConversionSequence::Indistinguishable; 1995 } 1996 1997 // If the types after this point are equivalent, we're done. 1998 if (Context.hasSameUnqualifiedType(T1, T2)) 1999 break; 2000 } 2001 2002 // Check that the winning standard conversion sequence isn't using 2003 // the deprecated string literal array to pointer conversion. 2004 switch (Result) { 2005 case ImplicitConversionSequence::Better: 2006 if (SCS1.DeprecatedStringLiteralToCharPtr) 2007 Result = ImplicitConversionSequence::Indistinguishable; 2008 break; 2009 2010 case ImplicitConversionSequence::Indistinguishable: 2011 break; 2012 2013 case ImplicitConversionSequence::Worse: 2014 if (SCS2.DeprecatedStringLiteralToCharPtr) 2015 Result = ImplicitConversionSequence::Indistinguishable; 2016 break; 2017 } 2018 2019 return Result; 2020} 2021 2022/// CompareDerivedToBaseConversions - Compares two standard conversion 2023/// sequences to determine whether they can be ranked based on their 2024/// various kinds of derived-to-base conversions (C++ 2025/// [over.ics.rank]p4b3). As part of these checks, we also look at 2026/// conversions between Objective-C interface types. 2027ImplicitConversionSequence::CompareKind 2028Sema::CompareDerivedToBaseConversions(const StandardConversionSequence& SCS1, 2029 const StandardConversionSequence& SCS2) { 2030 QualType FromType1 = SCS1.getFromType(); 2031 QualType ToType1 = SCS1.getToType(1); 2032 QualType FromType2 = SCS2.getFromType(); 2033 QualType ToType2 = SCS2.getToType(1); 2034 2035 // Adjust the types we're converting from via the array-to-pointer 2036 // conversion, if we need to. 2037 if (SCS1.First == ICK_Array_To_Pointer) 2038 FromType1 = Context.getArrayDecayedType(FromType1); 2039 if (SCS2.First == ICK_Array_To_Pointer) 2040 FromType2 = Context.getArrayDecayedType(FromType2); 2041 2042 // Canonicalize all of the types. 2043 FromType1 = Context.getCanonicalType(FromType1); 2044 ToType1 = Context.getCanonicalType(ToType1); 2045 FromType2 = Context.getCanonicalType(FromType2); 2046 ToType2 = Context.getCanonicalType(ToType2); 2047 2048 // C++ [over.ics.rank]p4b3: 2049 // 2050 // If class B is derived directly or indirectly from class A and 2051 // class C is derived directly or indirectly from B, 2052 // 2053 // For Objective-C, we let A, B, and C also be Objective-C 2054 // interfaces. 2055 2056 // Compare based on pointer conversions. 2057 if (SCS1.Second == ICK_Pointer_Conversion && 2058 SCS2.Second == ICK_Pointer_Conversion && 2059 /*FIXME: Remove if Objective-C id conversions get their own rank*/ 2060 FromType1->isPointerType() && FromType2->isPointerType() && 2061 ToType1->isPointerType() && ToType2->isPointerType()) { 2062 QualType FromPointee1 2063 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2064 QualType ToPointee1 2065 = ToType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2066 QualType FromPointee2 2067 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2068 QualType ToPointee2 2069 = ToType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2070 2071 const ObjCInterfaceType* FromIface1 = FromPointee1->getAs<ObjCInterfaceType>(); 2072 const ObjCInterfaceType* FromIface2 = FromPointee2->getAs<ObjCInterfaceType>(); 2073 const ObjCInterfaceType* ToIface1 = ToPointee1->getAs<ObjCInterfaceType>(); 2074 const ObjCInterfaceType* ToIface2 = ToPointee2->getAs<ObjCInterfaceType>(); 2075 2076 // -- conversion of C* to B* is better than conversion of C* to A*, 2077 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 2078 if (IsDerivedFrom(ToPointee1, ToPointee2)) 2079 return ImplicitConversionSequence::Better; 2080 else if (IsDerivedFrom(ToPointee2, ToPointee1)) 2081 return ImplicitConversionSequence::Worse; 2082 2083 if (ToIface1 && ToIface2) { 2084 if (Context.canAssignObjCInterfaces(ToIface2, ToIface1)) 2085 return ImplicitConversionSequence::Better; 2086 else if (Context.canAssignObjCInterfaces(ToIface1, ToIface2)) 2087 return ImplicitConversionSequence::Worse; 2088 } 2089 } 2090 2091 // -- conversion of B* to A* is better than conversion of C* to A*, 2092 if (FromPointee1 != FromPointee2 && ToPointee1 == ToPointee2) { 2093 if (IsDerivedFrom(FromPointee2, FromPointee1)) 2094 return ImplicitConversionSequence::Better; 2095 else if (IsDerivedFrom(FromPointee1, FromPointee2)) 2096 return ImplicitConversionSequence::Worse; 2097 2098 if (FromIface1 && FromIface2) { 2099 if (Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 2100 return ImplicitConversionSequence::Better; 2101 else if (Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 2102 return ImplicitConversionSequence::Worse; 2103 } 2104 } 2105 } 2106 2107 // Ranking of member-pointer types. 2108 if (SCS1.Second == ICK_Pointer_Member && SCS2.Second == ICK_Pointer_Member && 2109 FromType1->isMemberPointerType() && FromType2->isMemberPointerType() && 2110 ToType1->isMemberPointerType() && ToType2->isMemberPointerType()) { 2111 const MemberPointerType * FromMemPointer1 = 2112 FromType1->getAs<MemberPointerType>(); 2113 const MemberPointerType * ToMemPointer1 = 2114 ToType1->getAs<MemberPointerType>(); 2115 const MemberPointerType * FromMemPointer2 = 2116 FromType2->getAs<MemberPointerType>(); 2117 const MemberPointerType * ToMemPointer2 = 2118 ToType2->getAs<MemberPointerType>(); 2119 const Type *FromPointeeType1 = FromMemPointer1->getClass(); 2120 const Type *ToPointeeType1 = ToMemPointer1->getClass(); 2121 const Type *FromPointeeType2 = FromMemPointer2->getClass(); 2122 const Type *ToPointeeType2 = ToMemPointer2->getClass(); 2123 QualType FromPointee1 = QualType(FromPointeeType1, 0).getUnqualifiedType(); 2124 QualType ToPointee1 = QualType(ToPointeeType1, 0).getUnqualifiedType(); 2125 QualType FromPointee2 = QualType(FromPointeeType2, 0).getUnqualifiedType(); 2126 QualType ToPointee2 = QualType(ToPointeeType2, 0).getUnqualifiedType(); 2127 // conversion of A::* to B::* is better than conversion of A::* to C::*, 2128 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 2129 if (IsDerivedFrom(ToPointee1, ToPointee2)) 2130 return ImplicitConversionSequence::Worse; 2131 else if (IsDerivedFrom(ToPointee2, ToPointee1)) 2132 return ImplicitConversionSequence::Better; 2133 } 2134 // conversion of B::* to C::* is better than conversion of A::* to C::* 2135 if (ToPointee1 == ToPointee2 && FromPointee1 != FromPointee2) { 2136 if (IsDerivedFrom(FromPointee1, FromPointee2)) 2137 return ImplicitConversionSequence::Better; 2138 else if (IsDerivedFrom(FromPointee2, FromPointee1)) 2139 return ImplicitConversionSequence::Worse; 2140 } 2141 } 2142 2143 if ((SCS1.ReferenceBinding || SCS1.CopyConstructor) && 2144 (SCS2.ReferenceBinding || SCS2.CopyConstructor) && 2145 SCS1.Second == ICK_Derived_To_Base) { 2146 // -- conversion of C to B is better than conversion of C to A, 2147 // -- binding of an expression of type C to a reference of type 2148 // B& is better than binding an expression of type C to a 2149 // reference of type A&, 2150 if (Context.hasSameUnqualifiedType(FromType1, FromType2) && 2151 !Context.hasSameUnqualifiedType(ToType1, ToType2)) { 2152 if (IsDerivedFrom(ToType1, ToType2)) 2153 return ImplicitConversionSequence::Better; 2154 else if (IsDerivedFrom(ToType2, ToType1)) 2155 return ImplicitConversionSequence::Worse; 2156 } 2157 2158 // -- conversion of B to A is better than conversion of C to A. 2159 // -- binding of an expression of type B to a reference of type 2160 // A& is better than binding an expression of type C to a 2161 // reference of type A&, 2162 if (!Context.hasSameUnqualifiedType(FromType1, FromType2) && 2163 Context.hasSameUnqualifiedType(ToType1, ToType2)) { 2164 if (IsDerivedFrom(FromType2, FromType1)) 2165 return ImplicitConversionSequence::Better; 2166 else if (IsDerivedFrom(FromType1, FromType2)) 2167 return ImplicitConversionSequence::Worse; 2168 } 2169 } 2170 2171 return ImplicitConversionSequence::Indistinguishable; 2172} 2173 2174/// TryCopyInitialization - Try to copy-initialize a value of type 2175/// ToType from the expression From. Return the implicit conversion 2176/// sequence required to pass this argument, which may be a bad 2177/// conversion sequence (meaning that the argument cannot be passed to 2178/// a parameter of this type). If @p SuppressUserConversions, then we 2179/// do not permit any user-defined conversion sequences. If @p ForceRValue, 2180/// then we treat @p From as an rvalue, even if it is an lvalue. 2181ImplicitConversionSequence 2182Sema::TryCopyInitialization(Expr *From, QualType ToType, 2183 bool SuppressUserConversions, bool ForceRValue, 2184 bool InOverloadResolution) { 2185 if (ToType->isReferenceType()) { 2186 ImplicitConversionSequence ICS; 2187 ICS.setBad(BadConversionSequence::no_conversion, From, ToType); 2188 CheckReferenceInit(From, ToType, 2189 /*FIXME:*/From->getLocStart(), 2190 SuppressUserConversions, 2191 /*AllowExplicit=*/false, 2192 ForceRValue, 2193 &ICS); 2194 return ICS; 2195 } else { 2196 return TryImplicitConversion(From, ToType, 2197 SuppressUserConversions, 2198 /*AllowExplicit=*/false, 2199 ForceRValue, 2200 InOverloadResolution); 2201 } 2202} 2203 2204/// PerformCopyInitialization - Copy-initialize an object of type @p ToType with 2205/// the expression @p From. Returns true (and emits a diagnostic) if there was 2206/// an error, returns false if the initialization succeeded. Elidable should 2207/// be true when the copy may be elided (C++ 12.8p15). Overload resolution works 2208/// differently in C++0x for this case. 2209bool Sema::PerformCopyInitialization(Expr *&From, QualType ToType, 2210 AssignmentAction Action, bool Elidable) { 2211 if (!getLangOptions().CPlusPlus) { 2212 // In C, argument passing is the same as performing an assignment. 2213 QualType FromType = From->getType(); 2214 2215 AssignConvertType ConvTy = 2216 CheckSingleAssignmentConstraints(ToType, From); 2217 if (ConvTy != Compatible && 2218 CheckTransparentUnionArgumentConstraints(ToType, From) == Compatible) 2219 ConvTy = Compatible; 2220 2221 return DiagnoseAssignmentResult(ConvTy, From->getLocStart(), ToType, 2222 FromType, From, Action); 2223 } 2224 2225 if (ToType->isReferenceType()) 2226 return CheckReferenceInit(From, ToType, 2227 /*FIXME:*/From->getLocStart(), 2228 /*SuppressUserConversions=*/false, 2229 /*AllowExplicit=*/false, 2230 /*ForceRValue=*/false); 2231 2232 if (!PerformImplicitConversion(From, ToType, Action, 2233 /*AllowExplicit=*/false, Elidable)) 2234 return false; 2235 if (!DiagnoseMultipleUserDefinedConversion(From, ToType)) 2236 return Diag(From->getSourceRange().getBegin(), 2237 diag::err_typecheck_convert_incompatible) 2238 << ToType << From->getType() << Action << From->getSourceRange(); 2239 return true; 2240} 2241 2242/// TryObjectArgumentInitialization - Try to initialize the object 2243/// parameter of the given member function (@c Method) from the 2244/// expression @p From. 2245ImplicitConversionSequence 2246Sema::TryObjectArgumentInitialization(QualType OrigFromType, 2247 CXXMethodDecl *Method, 2248 CXXRecordDecl *ActingContext) { 2249 QualType ClassType = Context.getTypeDeclType(ActingContext); 2250 // [class.dtor]p2: A destructor can be invoked for a const, volatile or 2251 // const volatile object. 2252 unsigned Quals = isa<CXXDestructorDecl>(Method) ? 2253 Qualifiers::Const | Qualifiers::Volatile : Method->getTypeQualifiers(); 2254 QualType ImplicitParamType = Context.getCVRQualifiedType(ClassType, Quals); 2255 2256 // Set up the conversion sequence as a "bad" conversion, to allow us 2257 // to exit early. 2258 ImplicitConversionSequence ICS; 2259 2260 // We need to have an object of class type. 2261 QualType FromType = OrigFromType; 2262 if (const PointerType *PT = FromType->getAs<PointerType>()) 2263 FromType = PT->getPointeeType(); 2264 2265 assert(FromType->isRecordType()); 2266 2267 // The implicit object parameter is has the type "reference to cv X", 2268 // where X is the class of which the function is a member 2269 // (C++ [over.match.funcs]p4). However, when finding an implicit 2270 // conversion sequence for the argument, we are not allowed to 2271 // create temporaries or perform user-defined conversions 2272 // (C++ [over.match.funcs]p5). We perform a simplified version of 2273 // reference binding here, that allows class rvalues to bind to 2274 // non-constant references. 2275 2276 // First check the qualifiers. We don't care about lvalue-vs-rvalue 2277 // with the implicit object parameter (C++ [over.match.funcs]p5). 2278 QualType FromTypeCanon = Context.getCanonicalType(FromType); 2279 if (ImplicitParamType.getCVRQualifiers() 2280 != FromTypeCanon.getLocalCVRQualifiers() && 2281 !ImplicitParamType.isAtLeastAsQualifiedAs(FromTypeCanon)) { 2282 ICS.setBad(BadConversionSequence::bad_qualifiers, 2283 OrigFromType, ImplicitParamType); 2284 return ICS; 2285 } 2286 2287 // Check that we have either the same type or a derived type. It 2288 // affects the conversion rank. 2289 QualType ClassTypeCanon = Context.getCanonicalType(ClassType); 2290 ImplicitConversionKind SecondKind; 2291 if (ClassTypeCanon == FromTypeCanon.getLocalUnqualifiedType()) { 2292 SecondKind = ICK_Identity; 2293 } else if (IsDerivedFrom(FromType, ClassType)) 2294 SecondKind = ICK_Derived_To_Base; 2295 else { 2296 ICS.setBad(BadConversionSequence::unrelated_class, 2297 FromType, ImplicitParamType); 2298 return ICS; 2299 } 2300 2301 // Success. Mark this as a reference binding. 2302 ICS.setStandard(); 2303 ICS.Standard.setAsIdentityConversion(); 2304 ICS.Standard.Second = SecondKind; 2305 ICS.Standard.setFromType(FromType); 2306 ICS.Standard.setAllToTypes(ImplicitParamType); 2307 ICS.Standard.ReferenceBinding = true; 2308 ICS.Standard.DirectBinding = true; 2309 ICS.Standard.RRefBinding = false; 2310 return ICS; 2311} 2312 2313/// PerformObjectArgumentInitialization - Perform initialization of 2314/// the implicit object parameter for the given Method with the given 2315/// expression. 2316bool 2317Sema::PerformObjectArgumentInitialization(Expr *&From, 2318 NestedNameSpecifier *Qualifier, 2319 CXXMethodDecl *Method) { 2320 QualType FromRecordType, DestType; 2321 QualType ImplicitParamRecordType = 2322 Method->getThisType(Context)->getAs<PointerType>()->getPointeeType(); 2323 2324 if (const PointerType *PT = From->getType()->getAs<PointerType>()) { 2325 FromRecordType = PT->getPointeeType(); 2326 DestType = Method->getThisType(Context); 2327 } else { 2328 FromRecordType = From->getType(); 2329 DestType = ImplicitParamRecordType; 2330 } 2331 2332 // Note that we always use the true parent context when performing 2333 // the actual argument initialization. 2334 ImplicitConversionSequence ICS 2335 = TryObjectArgumentInitialization(From->getType(), Method, 2336 Method->getParent()); 2337 if (ICS.isBad()) 2338 return Diag(From->getSourceRange().getBegin(), 2339 diag::err_implicit_object_parameter_init) 2340 << ImplicitParamRecordType << FromRecordType << From->getSourceRange(); 2341 2342 if (ICS.Standard.Second == ICK_Derived_To_Base) 2343 return PerformObjectMemberConversion(From, Qualifier, Method); 2344 2345 if (!Context.hasSameType(From->getType(), DestType)) 2346 ImpCastExprToType(From, DestType, CastExpr::CK_NoOp, 2347 /*isLvalue=*/!From->getType()->getAs<PointerType>()); 2348 return false; 2349} 2350 2351/// TryContextuallyConvertToBool - Attempt to contextually convert the 2352/// expression From to bool (C++0x [conv]p3). 2353ImplicitConversionSequence Sema::TryContextuallyConvertToBool(Expr *From) { 2354 return TryImplicitConversion(From, Context.BoolTy, 2355 // FIXME: Are these flags correct? 2356 /*SuppressUserConversions=*/false, 2357 /*AllowExplicit=*/true, 2358 /*ForceRValue=*/false, 2359 /*InOverloadResolution=*/false); 2360} 2361 2362/// PerformContextuallyConvertToBool - Perform a contextual conversion 2363/// of the expression From to bool (C++0x [conv]p3). 2364bool Sema::PerformContextuallyConvertToBool(Expr *&From) { 2365 ImplicitConversionSequence ICS = TryContextuallyConvertToBool(From); 2366 if (!ICS.isBad()) 2367 return PerformImplicitConversion(From, Context.BoolTy, ICS, AA_Converting); 2368 2369 if (!DiagnoseMultipleUserDefinedConversion(From, Context.BoolTy)) 2370 return Diag(From->getSourceRange().getBegin(), 2371 diag::err_typecheck_bool_condition) 2372 << From->getType() << From->getSourceRange(); 2373 return true; 2374} 2375 2376/// AddOverloadCandidate - Adds the given function to the set of 2377/// candidate functions, using the given function call arguments. If 2378/// @p SuppressUserConversions, then don't allow user-defined 2379/// conversions via constructors or conversion operators. 2380/// If @p ForceRValue, treat all arguments as rvalues. This is a slightly 2381/// hacky way to implement the overloading rules for elidable copy 2382/// initialization in C++0x (C++0x 12.8p15). 2383/// 2384/// \para PartialOverloading true if we are performing "partial" overloading 2385/// based on an incomplete set of function arguments. This feature is used by 2386/// code completion. 2387void 2388Sema::AddOverloadCandidate(FunctionDecl *Function, 2389 DeclAccessPair FoundDecl, 2390 Expr **Args, unsigned NumArgs, 2391 OverloadCandidateSet& CandidateSet, 2392 bool SuppressUserConversions, 2393 bool ForceRValue, 2394 bool PartialOverloading) { 2395 const FunctionProtoType* Proto 2396 = dyn_cast<FunctionProtoType>(Function->getType()->getAs<FunctionType>()); 2397 assert(Proto && "Functions without a prototype cannot be overloaded"); 2398 assert(!Function->getDescribedFunctionTemplate() && 2399 "Use AddTemplateOverloadCandidate for function templates"); 2400 2401 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Function)) { 2402 if (!isa<CXXConstructorDecl>(Method)) { 2403 // If we get here, it's because we're calling a member function 2404 // that is named without a member access expression (e.g., 2405 // "this->f") that was either written explicitly or created 2406 // implicitly. This can happen with a qualified call to a member 2407 // function, e.g., X::f(). We use an empty type for the implied 2408 // object argument (C++ [over.call.func]p3), and the acting context 2409 // is irrelevant. 2410 AddMethodCandidate(Method, FoundDecl, Method->getParent(), 2411 QualType(), Args, NumArgs, CandidateSet, 2412 SuppressUserConversions, ForceRValue); 2413 return; 2414 } 2415 // We treat a constructor like a non-member function, since its object 2416 // argument doesn't participate in overload resolution. 2417 } 2418 2419 if (!CandidateSet.isNewCandidate(Function)) 2420 return; 2421 2422 // Overload resolution is always an unevaluated context. 2423 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 2424 2425 if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(Function)){ 2426 // C++ [class.copy]p3: 2427 // A member function template is never instantiated to perform the copy 2428 // of a class object to an object of its class type. 2429 QualType ClassType = Context.getTypeDeclType(Constructor->getParent()); 2430 if (NumArgs == 1 && 2431 Constructor->isCopyConstructorLikeSpecialization() && 2432 (Context.hasSameUnqualifiedType(ClassType, Args[0]->getType()) || 2433 IsDerivedFrom(Args[0]->getType(), ClassType))) 2434 return; 2435 } 2436 2437 // Add this candidate 2438 CandidateSet.push_back(OverloadCandidate()); 2439 OverloadCandidate& Candidate = CandidateSet.back(); 2440 Candidate.FoundDecl = FoundDecl; 2441 Candidate.Function = Function; 2442 Candidate.Viable = true; 2443 Candidate.IsSurrogate = false; 2444 Candidate.IgnoreObjectArgument = false; 2445 2446 unsigned NumArgsInProto = Proto->getNumArgs(); 2447 2448 // (C++ 13.3.2p2): A candidate function having fewer than m 2449 // parameters is viable only if it has an ellipsis in its parameter 2450 // list (8.3.5). 2451 if ((NumArgs + (PartialOverloading && NumArgs)) > NumArgsInProto && 2452 !Proto->isVariadic()) { 2453 Candidate.Viable = false; 2454 Candidate.FailureKind = ovl_fail_too_many_arguments; 2455 return; 2456 } 2457 2458 // (C++ 13.3.2p2): A candidate function having more than m parameters 2459 // is viable only if the (m+1)st parameter has a default argument 2460 // (8.3.6). For the purposes of overload resolution, the 2461 // parameter list is truncated on the right, so that there are 2462 // exactly m parameters. 2463 unsigned MinRequiredArgs = Function->getMinRequiredArguments(); 2464 if (NumArgs < MinRequiredArgs && !PartialOverloading) { 2465 // Not enough arguments. 2466 Candidate.Viable = false; 2467 Candidate.FailureKind = ovl_fail_too_few_arguments; 2468 return; 2469 } 2470 2471 // Determine the implicit conversion sequences for each of the 2472 // arguments. 2473 Candidate.Conversions.resize(NumArgs); 2474 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2475 if (ArgIdx < NumArgsInProto) { 2476 // (C++ 13.3.2p3): for F to be a viable function, there shall 2477 // exist for each argument an implicit conversion sequence 2478 // (13.3.3.1) that converts that argument to the corresponding 2479 // parameter of F. 2480 QualType ParamType = Proto->getArgType(ArgIdx); 2481 Candidate.Conversions[ArgIdx] 2482 = TryCopyInitialization(Args[ArgIdx], ParamType, 2483 SuppressUserConversions, ForceRValue, 2484 /*InOverloadResolution=*/true); 2485 if (Candidate.Conversions[ArgIdx].isBad()) { 2486 Candidate.Viable = false; 2487 Candidate.FailureKind = ovl_fail_bad_conversion; 2488 break; 2489 } 2490 } else { 2491 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2492 // argument for which there is no corresponding parameter is 2493 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2494 Candidate.Conversions[ArgIdx].setEllipsis(); 2495 } 2496 } 2497} 2498 2499/// \brief Add all of the function declarations in the given function set to 2500/// the overload canddiate set. 2501void Sema::AddFunctionCandidates(const UnresolvedSetImpl &Fns, 2502 Expr **Args, unsigned NumArgs, 2503 OverloadCandidateSet& CandidateSet, 2504 bool SuppressUserConversions) { 2505 for (UnresolvedSetIterator F = Fns.begin(), E = Fns.end(); F != E; ++F) { 2506 NamedDecl *D = F.getDecl()->getUnderlyingDecl(); 2507 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { 2508 if (isa<CXXMethodDecl>(FD) && !cast<CXXMethodDecl>(FD)->isStatic()) 2509 AddMethodCandidate(cast<CXXMethodDecl>(FD), F.getPair(), 2510 cast<CXXMethodDecl>(FD)->getParent(), 2511 Args[0]->getType(), Args + 1, NumArgs - 1, 2512 CandidateSet, SuppressUserConversions); 2513 else 2514 AddOverloadCandidate(FD, F.getPair(), Args, NumArgs, CandidateSet, 2515 SuppressUserConversions); 2516 } else { 2517 FunctionTemplateDecl *FunTmpl = cast<FunctionTemplateDecl>(D); 2518 if (isa<CXXMethodDecl>(FunTmpl->getTemplatedDecl()) && 2519 !cast<CXXMethodDecl>(FunTmpl->getTemplatedDecl())->isStatic()) 2520 AddMethodTemplateCandidate(FunTmpl, F.getPair(), 2521 cast<CXXRecordDecl>(FunTmpl->getDeclContext()), 2522 /*FIXME: explicit args */ 0, 2523 Args[0]->getType(), Args + 1, NumArgs - 1, 2524 CandidateSet, 2525 SuppressUserConversions); 2526 else 2527 AddTemplateOverloadCandidate(FunTmpl, F.getPair(), 2528 /*FIXME: explicit args */ 0, 2529 Args, NumArgs, CandidateSet, 2530 SuppressUserConversions); 2531 } 2532 } 2533} 2534 2535/// AddMethodCandidate - Adds a named decl (which is some kind of 2536/// method) as a method candidate to the given overload set. 2537void Sema::AddMethodCandidate(DeclAccessPair FoundDecl, 2538 QualType ObjectType, 2539 Expr **Args, unsigned NumArgs, 2540 OverloadCandidateSet& CandidateSet, 2541 bool SuppressUserConversions, bool ForceRValue) { 2542 NamedDecl *Decl = FoundDecl.getDecl(); 2543 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(Decl->getDeclContext()); 2544 2545 if (isa<UsingShadowDecl>(Decl)) 2546 Decl = cast<UsingShadowDecl>(Decl)->getTargetDecl(); 2547 2548 if (FunctionTemplateDecl *TD = dyn_cast<FunctionTemplateDecl>(Decl)) { 2549 assert(isa<CXXMethodDecl>(TD->getTemplatedDecl()) && 2550 "Expected a member function template"); 2551 AddMethodTemplateCandidate(TD, FoundDecl, ActingContext, 2552 /*ExplicitArgs*/ 0, 2553 ObjectType, Args, NumArgs, 2554 CandidateSet, 2555 SuppressUserConversions, 2556 ForceRValue); 2557 } else { 2558 AddMethodCandidate(cast<CXXMethodDecl>(Decl), FoundDecl, ActingContext, 2559 ObjectType, Args, NumArgs, 2560 CandidateSet, SuppressUserConversions, ForceRValue); 2561 } 2562} 2563 2564/// AddMethodCandidate - Adds the given C++ member function to the set 2565/// of candidate functions, using the given function call arguments 2566/// and the object argument (@c Object). For example, in a call 2567/// @c o.f(a1,a2), @c Object will contain @c o and @c Args will contain 2568/// both @c a1 and @c a2. If @p SuppressUserConversions, then don't 2569/// allow user-defined conversions via constructors or conversion 2570/// operators. If @p ForceRValue, treat all arguments as rvalues. This is 2571/// a slightly hacky way to implement the overloading rules for elidable copy 2572/// initialization in C++0x (C++0x 12.8p15). 2573void 2574Sema::AddMethodCandidate(CXXMethodDecl *Method, DeclAccessPair FoundDecl, 2575 CXXRecordDecl *ActingContext, QualType ObjectType, 2576 Expr **Args, unsigned NumArgs, 2577 OverloadCandidateSet& CandidateSet, 2578 bool SuppressUserConversions, bool ForceRValue) { 2579 const FunctionProtoType* Proto 2580 = dyn_cast<FunctionProtoType>(Method->getType()->getAs<FunctionType>()); 2581 assert(Proto && "Methods without a prototype cannot be overloaded"); 2582 assert(!isa<CXXConstructorDecl>(Method) && 2583 "Use AddOverloadCandidate for constructors"); 2584 2585 if (!CandidateSet.isNewCandidate(Method)) 2586 return; 2587 2588 // Overload resolution is always an unevaluated context. 2589 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 2590 2591 // Add this candidate 2592 CandidateSet.push_back(OverloadCandidate()); 2593 OverloadCandidate& Candidate = CandidateSet.back(); 2594 Candidate.FoundDecl = FoundDecl; 2595 Candidate.Function = Method; 2596 Candidate.IsSurrogate = false; 2597 Candidate.IgnoreObjectArgument = false; 2598 2599 unsigned NumArgsInProto = Proto->getNumArgs(); 2600 2601 // (C++ 13.3.2p2): A candidate function having fewer than m 2602 // parameters is viable only if it has an ellipsis in its parameter 2603 // list (8.3.5). 2604 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 2605 Candidate.Viable = false; 2606 Candidate.FailureKind = ovl_fail_too_many_arguments; 2607 return; 2608 } 2609 2610 // (C++ 13.3.2p2): A candidate function having more than m parameters 2611 // is viable only if the (m+1)st parameter has a default argument 2612 // (8.3.6). For the purposes of overload resolution, the 2613 // parameter list is truncated on the right, so that there are 2614 // exactly m parameters. 2615 unsigned MinRequiredArgs = Method->getMinRequiredArguments(); 2616 if (NumArgs < MinRequiredArgs) { 2617 // Not enough arguments. 2618 Candidate.Viable = false; 2619 Candidate.FailureKind = ovl_fail_too_few_arguments; 2620 return; 2621 } 2622 2623 Candidate.Viable = true; 2624 Candidate.Conversions.resize(NumArgs + 1); 2625 2626 if (Method->isStatic() || ObjectType.isNull()) 2627 // The implicit object argument is ignored. 2628 Candidate.IgnoreObjectArgument = true; 2629 else { 2630 // Determine the implicit conversion sequence for the object 2631 // parameter. 2632 Candidate.Conversions[0] 2633 = TryObjectArgumentInitialization(ObjectType, Method, ActingContext); 2634 if (Candidate.Conversions[0].isBad()) { 2635 Candidate.Viable = false; 2636 Candidate.FailureKind = ovl_fail_bad_conversion; 2637 return; 2638 } 2639 } 2640 2641 // Determine the implicit conversion sequences for each of the 2642 // arguments. 2643 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2644 if (ArgIdx < NumArgsInProto) { 2645 // (C++ 13.3.2p3): for F to be a viable function, there shall 2646 // exist for each argument an implicit conversion sequence 2647 // (13.3.3.1) that converts that argument to the corresponding 2648 // parameter of F. 2649 QualType ParamType = Proto->getArgType(ArgIdx); 2650 Candidate.Conversions[ArgIdx + 1] 2651 = TryCopyInitialization(Args[ArgIdx], ParamType, 2652 SuppressUserConversions, ForceRValue, 2653 /*InOverloadResolution=*/true); 2654 if (Candidate.Conversions[ArgIdx + 1].isBad()) { 2655 Candidate.Viable = false; 2656 Candidate.FailureKind = ovl_fail_bad_conversion; 2657 break; 2658 } 2659 } else { 2660 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2661 // argument for which there is no corresponding parameter is 2662 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2663 Candidate.Conversions[ArgIdx + 1].setEllipsis(); 2664 } 2665 } 2666} 2667 2668/// \brief Add a C++ member function template as a candidate to the candidate 2669/// set, using template argument deduction to produce an appropriate member 2670/// function template specialization. 2671void 2672Sema::AddMethodTemplateCandidate(FunctionTemplateDecl *MethodTmpl, 2673 DeclAccessPair FoundDecl, 2674 CXXRecordDecl *ActingContext, 2675 const TemplateArgumentListInfo *ExplicitTemplateArgs, 2676 QualType ObjectType, 2677 Expr **Args, unsigned NumArgs, 2678 OverloadCandidateSet& CandidateSet, 2679 bool SuppressUserConversions, 2680 bool ForceRValue) { 2681 if (!CandidateSet.isNewCandidate(MethodTmpl)) 2682 return; 2683 2684 // C++ [over.match.funcs]p7: 2685 // In each case where a candidate is a function template, candidate 2686 // function template specializations are generated using template argument 2687 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 2688 // candidate functions in the usual way.113) A given name can refer to one 2689 // or more function templates and also to a set of overloaded non-template 2690 // functions. In such a case, the candidate functions generated from each 2691 // function template are combined with the set of non-template candidate 2692 // functions. 2693 TemplateDeductionInfo Info(Context, CandidateSet.getLocation()); 2694 FunctionDecl *Specialization = 0; 2695 if (TemplateDeductionResult Result 2696 = DeduceTemplateArguments(MethodTmpl, ExplicitTemplateArgs, 2697 Args, NumArgs, Specialization, Info)) { 2698 // FIXME: Record what happened with template argument deduction, so 2699 // that we can give the user a beautiful diagnostic. 2700 (void)Result; 2701 return; 2702 } 2703 2704 // Add the function template specialization produced by template argument 2705 // deduction as a candidate. 2706 assert(Specialization && "Missing member function template specialization?"); 2707 assert(isa<CXXMethodDecl>(Specialization) && 2708 "Specialization is not a member function?"); 2709 AddMethodCandidate(cast<CXXMethodDecl>(Specialization), FoundDecl, 2710 ActingContext, ObjectType, Args, NumArgs, 2711 CandidateSet, SuppressUserConversions, ForceRValue); 2712} 2713 2714/// \brief Add a C++ function template specialization as a candidate 2715/// in the candidate set, using template argument deduction to produce 2716/// an appropriate function template specialization. 2717void 2718Sema::AddTemplateOverloadCandidate(FunctionTemplateDecl *FunctionTemplate, 2719 DeclAccessPair FoundDecl, 2720 const TemplateArgumentListInfo *ExplicitTemplateArgs, 2721 Expr **Args, unsigned NumArgs, 2722 OverloadCandidateSet& CandidateSet, 2723 bool SuppressUserConversions, 2724 bool ForceRValue) { 2725 if (!CandidateSet.isNewCandidate(FunctionTemplate)) 2726 return; 2727 2728 // C++ [over.match.funcs]p7: 2729 // In each case where a candidate is a function template, candidate 2730 // function template specializations are generated using template argument 2731 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 2732 // candidate functions in the usual way.113) A given name can refer to one 2733 // or more function templates and also to a set of overloaded non-template 2734 // functions. In such a case, the candidate functions generated from each 2735 // function template are combined with the set of non-template candidate 2736 // functions. 2737 TemplateDeductionInfo Info(Context, CandidateSet.getLocation()); 2738 FunctionDecl *Specialization = 0; 2739 if (TemplateDeductionResult Result 2740 = DeduceTemplateArguments(FunctionTemplate, ExplicitTemplateArgs, 2741 Args, NumArgs, Specialization, Info)) { 2742 CandidateSet.push_back(OverloadCandidate()); 2743 OverloadCandidate &Candidate = CandidateSet.back(); 2744 Candidate.FoundDecl = FoundDecl; 2745 Candidate.Function = FunctionTemplate->getTemplatedDecl(); 2746 Candidate.Viable = false; 2747 Candidate.FailureKind = ovl_fail_bad_deduction; 2748 Candidate.IsSurrogate = false; 2749 Candidate.IgnoreObjectArgument = false; 2750 2751 // TODO: record more information about failed template arguments 2752 Candidate.DeductionFailure.Result = Result; 2753 Candidate.DeductionFailure.TemplateParameter = Info.Param.getOpaqueValue(); 2754 return; 2755 } 2756 2757 // Add the function template specialization produced by template argument 2758 // deduction as a candidate. 2759 assert(Specialization && "Missing function template specialization?"); 2760 AddOverloadCandidate(Specialization, FoundDecl, Args, NumArgs, CandidateSet, 2761 SuppressUserConversions, ForceRValue); 2762} 2763 2764/// AddConversionCandidate - Add a C++ conversion function as a 2765/// candidate in the candidate set (C++ [over.match.conv], 2766/// C++ [over.match.copy]). From is the expression we're converting from, 2767/// and ToType is the type that we're eventually trying to convert to 2768/// (which may or may not be the same type as the type that the 2769/// conversion function produces). 2770void 2771Sema::AddConversionCandidate(CXXConversionDecl *Conversion, 2772 DeclAccessPair FoundDecl, 2773 CXXRecordDecl *ActingContext, 2774 Expr *From, QualType ToType, 2775 OverloadCandidateSet& CandidateSet) { 2776 assert(!Conversion->getDescribedFunctionTemplate() && 2777 "Conversion function templates use AddTemplateConversionCandidate"); 2778 2779 if (!CandidateSet.isNewCandidate(Conversion)) 2780 return; 2781 2782 // Overload resolution is always an unevaluated context. 2783 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 2784 2785 // Add this candidate 2786 CandidateSet.push_back(OverloadCandidate()); 2787 OverloadCandidate& Candidate = CandidateSet.back(); 2788 Candidate.FoundDecl = FoundDecl; 2789 Candidate.Function = Conversion; 2790 Candidate.IsSurrogate = false; 2791 Candidate.IgnoreObjectArgument = false; 2792 Candidate.FinalConversion.setAsIdentityConversion(); 2793 Candidate.FinalConversion.setFromType(Conversion->getConversionType()); 2794 Candidate.FinalConversion.setAllToTypes(ToType); 2795 2796 // Determine the implicit conversion sequence for the implicit 2797 // object parameter. 2798 Candidate.Viable = true; 2799 Candidate.Conversions.resize(1); 2800 Candidate.Conversions[0] 2801 = TryObjectArgumentInitialization(From->getType(), Conversion, 2802 ActingContext); 2803 // Conversion functions to a different type in the base class is visible in 2804 // the derived class. So, a derived to base conversion should not participate 2805 // in overload resolution. 2806 if (Candidate.Conversions[0].Standard.Second == ICK_Derived_To_Base) 2807 Candidate.Conversions[0].Standard.Second = ICK_Identity; 2808 if (Candidate.Conversions[0].isBad()) { 2809 Candidate.Viable = false; 2810 Candidate.FailureKind = ovl_fail_bad_conversion; 2811 return; 2812 } 2813 2814 // We won't go through a user-define type conversion function to convert a 2815 // derived to base as such conversions are given Conversion Rank. They only 2816 // go through a copy constructor. 13.3.3.1.2-p4 [over.ics.user] 2817 QualType FromCanon 2818 = Context.getCanonicalType(From->getType().getUnqualifiedType()); 2819 QualType ToCanon = Context.getCanonicalType(ToType).getUnqualifiedType(); 2820 if (FromCanon == ToCanon || IsDerivedFrom(FromCanon, ToCanon)) { 2821 Candidate.Viable = false; 2822 Candidate.FailureKind = ovl_fail_trivial_conversion; 2823 return; 2824 } 2825 2826 2827 // To determine what the conversion from the result of calling the 2828 // conversion function to the type we're eventually trying to 2829 // convert to (ToType), we need to synthesize a call to the 2830 // conversion function and attempt copy initialization from it. This 2831 // makes sure that we get the right semantics with respect to 2832 // lvalues/rvalues and the type. Fortunately, we can allocate this 2833 // call on the stack and we don't need its arguments to be 2834 // well-formed. 2835 DeclRefExpr ConversionRef(Conversion, Conversion->getType(), 2836 From->getLocStart()); 2837 ImplicitCastExpr ConversionFn(Context.getPointerType(Conversion->getType()), 2838 CastExpr::CK_FunctionToPointerDecay, 2839 &ConversionRef, false); 2840 2841 // Note that it is safe to allocate CallExpr on the stack here because 2842 // there are 0 arguments (i.e., nothing is allocated using ASTContext's 2843 // allocator). 2844 CallExpr Call(Context, &ConversionFn, 0, 0, 2845 Conversion->getConversionType().getNonReferenceType(), 2846 From->getLocStart()); 2847 ImplicitConversionSequence ICS = 2848 TryCopyInitialization(&Call, ToType, 2849 /*SuppressUserConversions=*/true, 2850 /*ForceRValue=*/false, 2851 /*InOverloadResolution=*/false); 2852 2853 switch (ICS.getKind()) { 2854 case ImplicitConversionSequence::StandardConversion: 2855 Candidate.FinalConversion = ICS.Standard; 2856 break; 2857 2858 case ImplicitConversionSequence::BadConversion: 2859 Candidate.Viable = false; 2860 Candidate.FailureKind = ovl_fail_bad_final_conversion; 2861 break; 2862 2863 default: 2864 assert(false && 2865 "Can only end up with a standard conversion sequence or failure"); 2866 } 2867} 2868 2869/// \brief Adds a conversion function template specialization 2870/// candidate to the overload set, using template argument deduction 2871/// to deduce the template arguments of the conversion function 2872/// template from the type that we are converting to (C++ 2873/// [temp.deduct.conv]). 2874void 2875Sema::AddTemplateConversionCandidate(FunctionTemplateDecl *FunctionTemplate, 2876 DeclAccessPair FoundDecl, 2877 CXXRecordDecl *ActingDC, 2878 Expr *From, QualType ToType, 2879 OverloadCandidateSet &CandidateSet) { 2880 assert(isa<CXXConversionDecl>(FunctionTemplate->getTemplatedDecl()) && 2881 "Only conversion function templates permitted here"); 2882 2883 if (!CandidateSet.isNewCandidate(FunctionTemplate)) 2884 return; 2885 2886 TemplateDeductionInfo Info(Context, CandidateSet.getLocation()); 2887 CXXConversionDecl *Specialization = 0; 2888 if (TemplateDeductionResult Result 2889 = DeduceTemplateArguments(FunctionTemplate, ToType, 2890 Specialization, Info)) { 2891 // FIXME: Record what happened with template argument deduction, so 2892 // that we can give the user a beautiful diagnostic. 2893 (void)Result; 2894 return; 2895 } 2896 2897 // Add the conversion function template specialization produced by 2898 // template argument deduction as a candidate. 2899 assert(Specialization && "Missing function template specialization?"); 2900 AddConversionCandidate(Specialization, FoundDecl, ActingDC, From, ToType, 2901 CandidateSet); 2902} 2903 2904/// AddSurrogateCandidate - Adds a "surrogate" candidate function that 2905/// converts the given @c Object to a function pointer via the 2906/// conversion function @c Conversion, and then attempts to call it 2907/// with the given arguments (C++ [over.call.object]p2-4). Proto is 2908/// the type of function that we'll eventually be calling. 2909void Sema::AddSurrogateCandidate(CXXConversionDecl *Conversion, 2910 DeclAccessPair FoundDecl, 2911 CXXRecordDecl *ActingContext, 2912 const FunctionProtoType *Proto, 2913 QualType ObjectType, 2914 Expr **Args, unsigned NumArgs, 2915 OverloadCandidateSet& CandidateSet) { 2916 if (!CandidateSet.isNewCandidate(Conversion)) 2917 return; 2918 2919 // Overload resolution is always an unevaluated context. 2920 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 2921 2922 CandidateSet.push_back(OverloadCandidate()); 2923 OverloadCandidate& Candidate = CandidateSet.back(); 2924 Candidate.FoundDecl = FoundDecl; 2925 Candidate.Function = 0; 2926 Candidate.Surrogate = Conversion; 2927 Candidate.Viable = true; 2928 Candidate.IsSurrogate = true; 2929 Candidate.IgnoreObjectArgument = false; 2930 Candidate.Conversions.resize(NumArgs + 1); 2931 2932 // Determine the implicit conversion sequence for the implicit 2933 // object parameter. 2934 ImplicitConversionSequence ObjectInit 2935 = TryObjectArgumentInitialization(ObjectType, Conversion, ActingContext); 2936 if (ObjectInit.isBad()) { 2937 Candidate.Viable = false; 2938 Candidate.FailureKind = ovl_fail_bad_conversion; 2939 Candidate.Conversions[0] = ObjectInit; 2940 return; 2941 } 2942 2943 // The first conversion is actually a user-defined conversion whose 2944 // first conversion is ObjectInit's standard conversion (which is 2945 // effectively a reference binding). Record it as such. 2946 Candidate.Conversions[0].setUserDefined(); 2947 Candidate.Conversions[0].UserDefined.Before = ObjectInit.Standard; 2948 Candidate.Conversions[0].UserDefined.EllipsisConversion = false; 2949 Candidate.Conversions[0].UserDefined.ConversionFunction = Conversion; 2950 Candidate.Conversions[0].UserDefined.After 2951 = Candidate.Conversions[0].UserDefined.Before; 2952 Candidate.Conversions[0].UserDefined.After.setAsIdentityConversion(); 2953 2954 // Find the 2955 unsigned NumArgsInProto = Proto->getNumArgs(); 2956 2957 // (C++ 13.3.2p2): A candidate function having fewer than m 2958 // parameters is viable only if it has an ellipsis in its parameter 2959 // list (8.3.5). 2960 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 2961 Candidate.Viable = false; 2962 Candidate.FailureKind = ovl_fail_too_many_arguments; 2963 return; 2964 } 2965 2966 // Function types don't have any default arguments, so just check if 2967 // we have enough arguments. 2968 if (NumArgs < NumArgsInProto) { 2969 // Not enough arguments. 2970 Candidate.Viable = false; 2971 Candidate.FailureKind = ovl_fail_too_few_arguments; 2972 return; 2973 } 2974 2975 // Determine the implicit conversion sequences for each of the 2976 // arguments. 2977 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2978 if (ArgIdx < NumArgsInProto) { 2979 // (C++ 13.3.2p3): for F to be a viable function, there shall 2980 // exist for each argument an implicit conversion sequence 2981 // (13.3.3.1) that converts that argument to the corresponding 2982 // parameter of F. 2983 QualType ParamType = Proto->getArgType(ArgIdx); 2984 Candidate.Conversions[ArgIdx + 1] 2985 = TryCopyInitialization(Args[ArgIdx], ParamType, 2986 /*SuppressUserConversions=*/false, 2987 /*ForceRValue=*/false, 2988 /*InOverloadResolution=*/false); 2989 if (Candidate.Conversions[ArgIdx + 1].isBad()) { 2990 Candidate.Viable = false; 2991 Candidate.FailureKind = ovl_fail_bad_conversion; 2992 break; 2993 } 2994 } else { 2995 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2996 // argument for which there is no corresponding parameter is 2997 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2998 Candidate.Conversions[ArgIdx + 1].setEllipsis(); 2999 } 3000 } 3001} 3002 3003// FIXME: This will eventually be removed, once we've migrated all of the 3004// operator overloading logic over to the scheme used by binary operators, which 3005// works for template instantiation. 3006void Sema::AddOperatorCandidates(OverloadedOperatorKind Op, Scope *S, 3007 SourceLocation OpLoc, 3008 Expr **Args, unsigned NumArgs, 3009 OverloadCandidateSet& CandidateSet, 3010 SourceRange OpRange) { 3011 UnresolvedSet<16> Fns; 3012 3013 QualType T1 = Args[0]->getType(); 3014 QualType T2; 3015 if (NumArgs > 1) 3016 T2 = Args[1]->getType(); 3017 3018 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 3019 if (S) 3020 LookupOverloadedOperatorName(Op, S, T1, T2, Fns); 3021 AddFunctionCandidates(Fns, Args, NumArgs, CandidateSet, false); 3022 AddArgumentDependentLookupCandidates(OpName, false, Args, NumArgs, 0, 3023 CandidateSet); 3024 AddMemberOperatorCandidates(Op, OpLoc, Args, NumArgs, CandidateSet, OpRange); 3025 AddBuiltinOperatorCandidates(Op, OpLoc, Args, NumArgs, CandidateSet); 3026} 3027 3028/// \brief Add overload candidates for overloaded operators that are 3029/// member functions. 3030/// 3031/// Add the overloaded operator candidates that are member functions 3032/// for the operator Op that was used in an operator expression such 3033/// as "x Op y". , Args/NumArgs provides the operator arguments, and 3034/// CandidateSet will store the added overload candidates. (C++ 3035/// [over.match.oper]). 3036void Sema::AddMemberOperatorCandidates(OverloadedOperatorKind Op, 3037 SourceLocation OpLoc, 3038 Expr **Args, unsigned NumArgs, 3039 OverloadCandidateSet& CandidateSet, 3040 SourceRange OpRange) { 3041 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 3042 3043 // C++ [over.match.oper]p3: 3044 // For a unary operator @ with an operand of a type whose 3045 // cv-unqualified version is T1, and for a binary operator @ with 3046 // a left operand of a type whose cv-unqualified version is T1 and 3047 // a right operand of a type whose cv-unqualified version is T2, 3048 // three sets of candidate functions, designated member 3049 // candidates, non-member candidates and built-in candidates, are 3050 // constructed as follows: 3051 QualType T1 = Args[0]->getType(); 3052 QualType T2; 3053 if (NumArgs > 1) 3054 T2 = Args[1]->getType(); 3055 3056 // -- If T1 is a class type, the set of member candidates is the 3057 // result of the qualified lookup of T1::operator@ 3058 // (13.3.1.1.1); otherwise, the set of member candidates is 3059 // empty. 3060 if (const RecordType *T1Rec = T1->getAs<RecordType>()) { 3061 // Complete the type if it can be completed. Otherwise, we're done. 3062 if (RequireCompleteType(OpLoc, T1, PDiag())) 3063 return; 3064 3065 LookupResult Operators(*this, OpName, OpLoc, LookupOrdinaryName); 3066 LookupQualifiedName(Operators, T1Rec->getDecl()); 3067 Operators.suppressDiagnostics(); 3068 3069 for (LookupResult::iterator Oper = Operators.begin(), 3070 OperEnd = Operators.end(); 3071 Oper != OperEnd; 3072 ++Oper) 3073 AddMethodCandidate(Oper.getPair(), Args[0]->getType(), 3074 Args + 1, NumArgs - 1, CandidateSet, 3075 /* SuppressUserConversions = */ false); 3076 } 3077} 3078 3079/// AddBuiltinCandidate - Add a candidate for a built-in 3080/// operator. ResultTy and ParamTys are the result and parameter types 3081/// of the built-in candidate, respectively. Args and NumArgs are the 3082/// arguments being passed to the candidate. IsAssignmentOperator 3083/// should be true when this built-in candidate is an assignment 3084/// operator. NumContextualBoolArguments is the number of arguments 3085/// (at the beginning of the argument list) that will be contextually 3086/// converted to bool. 3087void Sema::AddBuiltinCandidate(QualType ResultTy, QualType *ParamTys, 3088 Expr **Args, unsigned NumArgs, 3089 OverloadCandidateSet& CandidateSet, 3090 bool IsAssignmentOperator, 3091 unsigned NumContextualBoolArguments) { 3092 // Overload resolution is always an unevaluated context. 3093 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 3094 3095 // Add this candidate 3096 CandidateSet.push_back(OverloadCandidate()); 3097 OverloadCandidate& Candidate = CandidateSet.back(); 3098 Candidate.FoundDecl = DeclAccessPair::make(0, AS_none); 3099 Candidate.Function = 0; 3100 Candidate.IsSurrogate = false; 3101 Candidate.IgnoreObjectArgument = false; 3102 Candidate.BuiltinTypes.ResultTy = ResultTy; 3103 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 3104 Candidate.BuiltinTypes.ParamTypes[ArgIdx] = ParamTys[ArgIdx]; 3105 3106 // Determine the implicit conversion sequences for each of the 3107 // arguments. 3108 Candidate.Viable = true; 3109 Candidate.Conversions.resize(NumArgs); 3110 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 3111 // C++ [over.match.oper]p4: 3112 // For the built-in assignment operators, conversions of the 3113 // left operand are restricted as follows: 3114 // -- no temporaries are introduced to hold the left operand, and 3115 // -- no user-defined conversions are applied to the left 3116 // operand to achieve a type match with the left-most 3117 // parameter of a built-in candidate. 3118 // 3119 // We block these conversions by turning off user-defined 3120 // conversions, since that is the only way that initialization of 3121 // a reference to a non-class type can occur from something that 3122 // is not of the same type. 3123 if (ArgIdx < NumContextualBoolArguments) { 3124 assert(ParamTys[ArgIdx] == Context.BoolTy && 3125 "Contextual conversion to bool requires bool type"); 3126 Candidate.Conversions[ArgIdx] = TryContextuallyConvertToBool(Args[ArgIdx]); 3127 } else { 3128 Candidate.Conversions[ArgIdx] 3129 = TryCopyInitialization(Args[ArgIdx], ParamTys[ArgIdx], 3130 ArgIdx == 0 && IsAssignmentOperator, 3131 /*ForceRValue=*/false, 3132 /*InOverloadResolution=*/false); 3133 } 3134 if (Candidate.Conversions[ArgIdx].isBad()) { 3135 Candidate.Viable = false; 3136 Candidate.FailureKind = ovl_fail_bad_conversion; 3137 break; 3138 } 3139 } 3140} 3141 3142/// BuiltinCandidateTypeSet - A set of types that will be used for the 3143/// candidate operator functions for built-in operators (C++ 3144/// [over.built]). The types are separated into pointer types and 3145/// enumeration types. 3146class BuiltinCandidateTypeSet { 3147 /// TypeSet - A set of types. 3148 typedef llvm::SmallPtrSet<QualType, 8> TypeSet; 3149 3150 /// PointerTypes - The set of pointer types that will be used in the 3151 /// built-in candidates. 3152 TypeSet PointerTypes; 3153 3154 /// MemberPointerTypes - The set of member pointer types that will be 3155 /// used in the built-in candidates. 3156 TypeSet MemberPointerTypes; 3157 3158 /// EnumerationTypes - The set of enumeration types that will be 3159 /// used in the built-in candidates. 3160 TypeSet EnumerationTypes; 3161 3162 /// Sema - The semantic analysis instance where we are building the 3163 /// candidate type set. 3164 Sema &SemaRef; 3165 3166 /// Context - The AST context in which we will build the type sets. 3167 ASTContext &Context; 3168 3169 bool AddPointerWithMoreQualifiedTypeVariants(QualType Ty, 3170 const Qualifiers &VisibleQuals); 3171 bool AddMemberPointerWithMoreQualifiedTypeVariants(QualType Ty); 3172 3173public: 3174 /// iterator - Iterates through the types that are part of the set. 3175 typedef TypeSet::iterator iterator; 3176 3177 BuiltinCandidateTypeSet(Sema &SemaRef) 3178 : SemaRef(SemaRef), Context(SemaRef.Context) { } 3179 3180 void AddTypesConvertedFrom(QualType Ty, 3181 SourceLocation Loc, 3182 bool AllowUserConversions, 3183 bool AllowExplicitConversions, 3184 const Qualifiers &VisibleTypeConversionsQuals); 3185 3186 /// pointer_begin - First pointer type found; 3187 iterator pointer_begin() { return PointerTypes.begin(); } 3188 3189 /// pointer_end - Past the last pointer type found; 3190 iterator pointer_end() { return PointerTypes.end(); } 3191 3192 /// member_pointer_begin - First member pointer type found; 3193 iterator member_pointer_begin() { return MemberPointerTypes.begin(); } 3194 3195 /// member_pointer_end - Past the last member pointer type found; 3196 iterator member_pointer_end() { return MemberPointerTypes.end(); } 3197 3198 /// enumeration_begin - First enumeration type found; 3199 iterator enumeration_begin() { return EnumerationTypes.begin(); } 3200 3201 /// enumeration_end - Past the last enumeration type found; 3202 iterator enumeration_end() { return EnumerationTypes.end(); } 3203}; 3204 3205/// AddPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty to 3206/// the set of pointer types along with any more-qualified variants of 3207/// that type. For example, if @p Ty is "int const *", this routine 3208/// will add "int const *", "int const volatile *", "int const 3209/// restrict *", and "int const volatile restrict *" to the set of 3210/// pointer types. Returns true if the add of @p Ty itself succeeded, 3211/// false otherwise. 3212/// 3213/// FIXME: what to do about extended qualifiers? 3214bool 3215BuiltinCandidateTypeSet::AddPointerWithMoreQualifiedTypeVariants(QualType Ty, 3216 const Qualifiers &VisibleQuals) { 3217 3218 // Insert this type. 3219 if (!PointerTypes.insert(Ty)) 3220 return false; 3221 3222 const PointerType *PointerTy = Ty->getAs<PointerType>(); 3223 assert(PointerTy && "type was not a pointer type!"); 3224 3225 QualType PointeeTy = PointerTy->getPointeeType(); 3226 // Don't add qualified variants of arrays. For one, they're not allowed 3227 // (the qualifier would sink to the element type), and for another, the 3228 // only overload situation where it matters is subscript or pointer +- int, 3229 // and those shouldn't have qualifier variants anyway. 3230 if (PointeeTy->isArrayType()) 3231 return true; 3232 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 3233 if (const ConstantArrayType *Array =Context.getAsConstantArrayType(PointeeTy)) 3234 BaseCVR = Array->getElementType().getCVRQualifiers(); 3235 bool hasVolatile = VisibleQuals.hasVolatile(); 3236 bool hasRestrict = VisibleQuals.hasRestrict(); 3237 3238 // Iterate through all strict supersets of BaseCVR. 3239 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 3240 if ((CVR | BaseCVR) != CVR) continue; 3241 // Skip over Volatile/Restrict if no Volatile/Restrict found anywhere 3242 // in the types. 3243 if ((CVR & Qualifiers::Volatile) && !hasVolatile) continue; 3244 if ((CVR & Qualifiers::Restrict) && !hasRestrict) continue; 3245 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 3246 PointerTypes.insert(Context.getPointerType(QPointeeTy)); 3247 } 3248 3249 return true; 3250} 3251 3252/// AddMemberPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty 3253/// to the set of pointer types along with any more-qualified variants of 3254/// that type. For example, if @p Ty is "int const *", this routine 3255/// will add "int const *", "int const volatile *", "int const 3256/// restrict *", and "int const volatile restrict *" to the set of 3257/// pointer types. Returns true if the add of @p Ty itself succeeded, 3258/// false otherwise. 3259/// 3260/// FIXME: what to do about extended qualifiers? 3261bool 3262BuiltinCandidateTypeSet::AddMemberPointerWithMoreQualifiedTypeVariants( 3263 QualType Ty) { 3264 // Insert this type. 3265 if (!MemberPointerTypes.insert(Ty)) 3266 return false; 3267 3268 const MemberPointerType *PointerTy = Ty->getAs<MemberPointerType>(); 3269 assert(PointerTy && "type was not a member pointer type!"); 3270 3271 QualType PointeeTy = PointerTy->getPointeeType(); 3272 // Don't add qualified variants of arrays. For one, they're not allowed 3273 // (the qualifier would sink to the element type), and for another, the 3274 // only overload situation where it matters is subscript or pointer +- int, 3275 // and those shouldn't have qualifier variants anyway. 3276 if (PointeeTy->isArrayType()) 3277 return true; 3278 const Type *ClassTy = PointerTy->getClass(); 3279 3280 // Iterate through all strict supersets of the pointee type's CVR 3281 // qualifiers. 3282 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 3283 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 3284 if ((CVR | BaseCVR) != CVR) continue; 3285 3286 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 3287 MemberPointerTypes.insert(Context.getMemberPointerType(QPointeeTy, ClassTy)); 3288 } 3289 3290 return true; 3291} 3292 3293/// AddTypesConvertedFrom - Add each of the types to which the type @p 3294/// Ty can be implicit converted to the given set of @p Types. We're 3295/// primarily interested in pointer types and enumeration types. We also 3296/// take member pointer types, for the conditional operator. 3297/// AllowUserConversions is true if we should look at the conversion 3298/// functions of a class type, and AllowExplicitConversions if we 3299/// should also include the explicit conversion functions of a class 3300/// type. 3301void 3302BuiltinCandidateTypeSet::AddTypesConvertedFrom(QualType Ty, 3303 SourceLocation Loc, 3304 bool AllowUserConversions, 3305 bool AllowExplicitConversions, 3306 const Qualifiers &VisibleQuals) { 3307 // Only deal with canonical types. 3308 Ty = Context.getCanonicalType(Ty); 3309 3310 // Look through reference types; they aren't part of the type of an 3311 // expression for the purposes of conversions. 3312 if (const ReferenceType *RefTy = Ty->getAs<ReferenceType>()) 3313 Ty = RefTy->getPointeeType(); 3314 3315 // We don't care about qualifiers on the type. 3316 Ty = Ty.getLocalUnqualifiedType(); 3317 3318 // If we're dealing with an array type, decay to the pointer. 3319 if (Ty->isArrayType()) 3320 Ty = SemaRef.Context.getArrayDecayedType(Ty); 3321 3322 if (const PointerType *PointerTy = Ty->getAs<PointerType>()) { 3323 QualType PointeeTy = PointerTy->getPointeeType(); 3324 3325 // Insert our type, and its more-qualified variants, into the set 3326 // of types. 3327 if (!AddPointerWithMoreQualifiedTypeVariants(Ty, VisibleQuals)) 3328 return; 3329 } else if (Ty->isMemberPointerType()) { 3330 // Member pointers are far easier, since the pointee can't be converted. 3331 if (!AddMemberPointerWithMoreQualifiedTypeVariants(Ty)) 3332 return; 3333 } else if (Ty->isEnumeralType()) { 3334 EnumerationTypes.insert(Ty); 3335 } else if (AllowUserConversions) { 3336 if (const RecordType *TyRec = Ty->getAs<RecordType>()) { 3337 if (SemaRef.RequireCompleteType(Loc, Ty, 0)) { 3338 // No conversion functions in incomplete types. 3339 return; 3340 } 3341 3342 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 3343 const UnresolvedSetImpl *Conversions 3344 = ClassDecl->getVisibleConversionFunctions(); 3345 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 3346 E = Conversions->end(); I != E; ++I) { 3347 3348 // Skip conversion function templates; they don't tell us anything 3349 // about which builtin types we can convert to. 3350 if (isa<FunctionTemplateDecl>(*I)) 3351 continue; 3352 3353 CXXConversionDecl *Conv = cast<CXXConversionDecl>(*I); 3354 if (AllowExplicitConversions || !Conv->isExplicit()) { 3355 AddTypesConvertedFrom(Conv->getConversionType(), Loc, false, false, 3356 VisibleQuals); 3357 } 3358 } 3359 } 3360 } 3361} 3362 3363/// \brief Helper function for AddBuiltinOperatorCandidates() that adds 3364/// the volatile- and non-volatile-qualified assignment operators for the 3365/// given type to the candidate set. 3366static void AddBuiltinAssignmentOperatorCandidates(Sema &S, 3367 QualType T, 3368 Expr **Args, 3369 unsigned NumArgs, 3370 OverloadCandidateSet &CandidateSet) { 3371 QualType ParamTypes[2]; 3372 3373 // T& operator=(T&, T) 3374 ParamTypes[0] = S.Context.getLValueReferenceType(T); 3375 ParamTypes[1] = T; 3376 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3377 /*IsAssignmentOperator=*/true); 3378 3379 if (!S.Context.getCanonicalType(T).isVolatileQualified()) { 3380 // volatile T& operator=(volatile T&, T) 3381 ParamTypes[0] 3382 = S.Context.getLValueReferenceType(S.Context.getVolatileType(T)); 3383 ParamTypes[1] = T; 3384 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3385 /*IsAssignmentOperator=*/true); 3386 } 3387} 3388 3389/// CollectVRQualifiers - This routine returns Volatile/Restrict qualifiers, 3390/// if any, found in visible type conversion functions found in ArgExpr's type. 3391static Qualifiers CollectVRQualifiers(ASTContext &Context, Expr* ArgExpr) { 3392 Qualifiers VRQuals; 3393 const RecordType *TyRec; 3394 if (const MemberPointerType *RHSMPType = 3395 ArgExpr->getType()->getAs<MemberPointerType>()) 3396 TyRec = cast<RecordType>(RHSMPType->getClass()); 3397 else 3398 TyRec = ArgExpr->getType()->getAs<RecordType>(); 3399 if (!TyRec) { 3400 // Just to be safe, assume the worst case. 3401 VRQuals.addVolatile(); 3402 VRQuals.addRestrict(); 3403 return VRQuals; 3404 } 3405 3406 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 3407 if (!ClassDecl->hasDefinition()) 3408 return VRQuals; 3409 3410 const UnresolvedSetImpl *Conversions = 3411 ClassDecl->getVisibleConversionFunctions(); 3412 3413 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 3414 E = Conversions->end(); I != E; ++I) { 3415 if (CXXConversionDecl *Conv = dyn_cast<CXXConversionDecl>(*I)) { 3416 QualType CanTy = Context.getCanonicalType(Conv->getConversionType()); 3417 if (const ReferenceType *ResTypeRef = CanTy->getAs<ReferenceType>()) 3418 CanTy = ResTypeRef->getPointeeType(); 3419 // Need to go down the pointer/mempointer chain and add qualifiers 3420 // as see them. 3421 bool done = false; 3422 while (!done) { 3423 if (const PointerType *ResTypePtr = CanTy->getAs<PointerType>()) 3424 CanTy = ResTypePtr->getPointeeType(); 3425 else if (const MemberPointerType *ResTypeMPtr = 3426 CanTy->getAs<MemberPointerType>()) 3427 CanTy = ResTypeMPtr->getPointeeType(); 3428 else 3429 done = true; 3430 if (CanTy.isVolatileQualified()) 3431 VRQuals.addVolatile(); 3432 if (CanTy.isRestrictQualified()) 3433 VRQuals.addRestrict(); 3434 if (VRQuals.hasRestrict() && VRQuals.hasVolatile()) 3435 return VRQuals; 3436 } 3437 } 3438 } 3439 return VRQuals; 3440} 3441 3442/// AddBuiltinOperatorCandidates - Add the appropriate built-in 3443/// operator overloads to the candidate set (C++ [over.built]), based 3444/// on the operator @p Op and the arguments given. For example, if the 3445/// operator is a binary '+', this routine might add "int 3446/// operator+(int, int)" to cover integer addition. 3447void 3448Sema::AddBuiltinOperatorCandidates(OverloadedOperatorKind Op, 3449 SourceLocation OpLoc, 3450 Expr **Args, unsigned NumArgs, 3451 OverloadCandidateSet& CandidateSet) { 3452 // The set of "promoted arithmetic types", which are the arithmetic 3453 // types are that preserved by promotion (C++ [over.built]p2). Note 3454 // that the first few of these types are the promoted integral 3455 // types; these types need to be first. 3456 // FIXME: What about complex? 3457 const unsigned FirstIntegralType = 0; 3458 const unsigned LastIntegralType = 13; 3459 const unsigned FirstPromotedIntegralType = 7, 3460 LastPromotedIntegralType = 13; 3461 const unsigned FirstPromotedArithmeticType = 7, 3462 LastPromotedArithmeticType = 16; 3463 const unsigned NumArithmeticTypes = 16; 3464 QualType ArithmeticTypes[NumArithmeticTypes] = { 3465 Context.BoolTy, Context.CharTy, Context.WCharTy, 3466// FIXME: Context.Char16Ty, Context.Char32Ty, 3467 Context.SignedCharTy, Context.ShortTy, 3468 Context.UnsignedCharTy, Context.UnsignedShortTy, 3469 Context.IntTy, Context.LongTy, Context.LongLongTy, 3470 Context.UnsignedIntTy, Context.UnsignedLongTy, Context.UnsignedLongLongTy, 3471 Context.FloatTy, Context.DoubleTy, Context.LongDoubleTy 3472 }; 3473 assert(ArithmeticTypes[FirstPromotedIntegralType] == Context.IntTy && 3474 "Invalid first promoted integral type"); 3475 assert(ArithmeticTypes[LastPromotedIntegralType - 1] 3476 == Context.UnsignedLongLongTy && 3477 "Invalid last promoted integral type"); 3478 assert(ArithmeticTypes[FirstPromotedArithmeticType] == Context.IntTy && 3479 "Invalid first promoted arithmetic type"); 3480 assert(ArithmeticTypes[LastPromotedArithmeticType - 1] 3481 == Context.LongDoubleTy && 3482 "Invalid last promoted arithmetic type"); 3483 3484 // Find all of the types that the arguments can convert to, but only 3485 // if the operator we're looking at has built-in operator candidates 3486 // that make use of these types. 3487 Qualifiers VisibleTypeConversionsQuals; 3488 VisibleTypeConversionsQuals.addConst(); 3489 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 3490 VisibleTypeConversionsQuals += CollectVRQualifiers(Context, Args[ArgIdx]); 3491 3492 BuiltinCandidateTypeSet CandidateTypes(*this); 3493 if (Op == OO_Less || Op == OO_Greater || Op == OO_LessEqual || 3494 Op == OO_GreaterEqual || Op == OO_EqualEqual || Op == OO_ExclaimEqual || 3495 Op == OO_Plus || (Op == OO_Minus && NumArgs == 2) || Op == OO_Equal || 3496 Op == OO_PlusEqual || Op == OO_MinusEqual || Op == OO_Subscript || 3497 Op == OO_ArrowStar || Op == OO_PlusPlus || Op == OO_MinusMinus || 3498 (Op == OO_Star && NumArgs == 1) || Op == OO_Conditional) { 3499 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 3500 CandidateTypes.AddTypesConvertedFrom(Args[ArgIdx]->getType(), 3501 OpLoc, 3502 true, 3503 (Op == OO_Exclaim || 3504 Op == OO_AmpAmp || 3505 Op == OO_PipePipe), 3506 VisibleTypeConversionsQuals); 3507 } 3508 3509 bool isComparison = false; 3510 switch (Op) { 3511 case OO_None: 3512 case NUM_OVERLOADED_OPERATORS: 3513 assert(false && "Expected an overloaded operator"); 3514 break; 3515 3516 case OO_Star: // '*' is either unary or binary 3517 if (NumArgs == 1) 3518 goto UnaryStar; 3519 else 3520 goto BinaryStar; 3521 break; 3522 3523 case OO_Plus: // '+' is either unary or binary 3524 if (NumArgs == 1) 3525 goto UnaryPlus; 3526 else 3527 goto BinaryPlus; 3528 break; 3529 3530 case OO_Minus: // '-' is either unary or binary 3531 if (NumArgs == 1) 3532 goto UnaryMinus; 3533 else 3534 goto BinaryMinus; 3535 break; 3536 3537 case OO_Amp: // '&' is either unary or binary 3538 if (NumArgs == 1) 3539 goto UnaryAmp; 3540 else 3541 goto BinaryAmp; 3542 3543 case OO_PlusPlus: 3544 case OO_MinusMinus: 3545 // C++ [over.built]p3: 3546 // 3547 // For every pair (T, VQ), where T is an arithmetic type, and VQ 3548 // is either volatile or empty, there exist candidate operator 3549 // functions of the form 3550 // 3551 // VQ T& operator++(VQ T&); 3552 // T operator++(VQ T&, int); 3553 // 3554 // C++ [over.built]p4: 3555 // 3556 // For every pair (T, VQ), where T is an arithmetic type other 3557 // than bool, and VQ is either volatile or empty, there exist 3558 // candidate operator functions of the form 3559 // 3560 // VQ T& operator--(VQ T&); 3561 // T operator--(VQ T&, int); 3562 for (unsigned Arith = (Op == OO_PlusPlus? 0 : 1); 3563 Arith < NumArithmeticTypes; ++Arith) { 3564 QualType ArithTy = ArithmeticTypes[Arith]; 3565 QualType ParamTypes[2] 3566 = { Context.getLValueReferenceType(ArithTy), Context.IntTy }; 3567 3568 // Non-volatile version. 3569 if (NumArgs == 1) 3570 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3571 else 3572 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 3573 // heuristic to reduce number of builtin candidates in the set. 3574 // Add volatile version only if there are conversions to a volatile type. 3575 if (VisibleTypeConversionsQuals.hasVolatile()) { 3576 // Volatile version 3577 ParamTypes[0] 3578 = Context.getLValueReferenceType(Context.getVolatileType(ArithTy)); 3579 if (NumArgs == 1) 3580 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3581 else 3582 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 3583 } 3584 } 3585 3586 // C++ [over.built]p5: 3587 // 3588 // For every pair (T, VQ), where T is a cv-qualified or 3589 // cv-unqualified object type, and VQ is either volatile or 3590 // empty, there exist candidate operator functions of the form 3591 // 3592 // T*VQ& operator++(T*VQ&); 3593 // T*VQ& operator--(T*VQ&); 3594 // T* operator++(T*VQ&, int); 3595 // T* operator--(T*VQ&, int); 3596 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3597 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3598 // Skip pointer types that aren't pointers to object types. 3599 if (!(*Ptr)->getAs<PointerType>()->getPointeeType()->isObjectType()) 3600 continue; 3601 3602 QualType ParamTypes[2] = { 3603 Context.getLValueReferenceType(*Ptr), Context.IntTy 3604 }; 3605 3606 // Without volatile 3607 if (NumArgs == 1) 3608 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3609 else 3610 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3611 3612 if (!Context.getCanonicalType(*Ptr).isVolatileQualified() && 3613 VisibleTypeConversionsQuals.hasVolatile()) { 3614 // With volatile 3615 ParamTypes[0] 3616 = Context.getLValueReferenceType(Context.getVolatileType(*Ptr)); 3617 if (NumArgs == 1) 3618 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3619 else 3620 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3621 } 3622 } 3623 break; 3624 3625 UnaryStar: 3626 // C++ [over.built]p6: 3627 // For every cv-qualified or cv-unqualified object type T, there 3628 // exist candidate operator functions of the form 3629 // 3630 // T& operator*(T*); 3631 // 3632 // C++ [over.built]p7: 3633 // For every function type T, there exist candidate operator 3634 // functions of the form 3635 // T& operator*(T*); 3636 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3637 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3638 QualType ParamTy = *Ptr; 3639 QualType PointeeTy = ParamTy->getAs<PointerType>()->getPointeeType(); 3640 AddBuiltinCandidate(Context.getLValueReferenceType(PointeeTy), 3641 &ParamTy, Args, 1, CandidateSet); 3642 } 3643 break; 3644 3645 UnaryPlus: 3646 // C++ [over.built]p8: 3647 // For every type T, there exist candidate operator functions of 3648 // the form 3649 // 3650 // T* operator+(T*); 3651 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3652 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3653 QualType ParamTy = *Ptr; 3654 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet); 3655 } 3656 3657 // Fall through 3658 3659 UnaryMinus: 3660 // C++ [over.built]p9: 3661 // For every promoted arithmetic type T, there exist candidate 3662 // operator functions of the form 3663 // 3664 // T operator+(T); 3665 // T operator-(T); 3666 for (unsigned Arith = FirstPromotedArithmeticType; 3667 Arith < LastPromotedArithmeticType; ++Arith) { 3668 QualType ArithTy = ArithmeticTypes[Arith]; 3669 AddBuiltinCandidate(ArithTy, &ArithTy, Args, 1, CandidateSet); 3670 } 3671 break; 3672 3673 case OO_Tilde: 3674 // C++ [over.built]p10: 3675 // For every promoted integral type T, there exist candidate 3676 // operator functions of the form 3677 // 3678 // T operator~(T); 3679 for (unsigned Int = FirstPromotedIntegralType; 3680 Int < LastPromotedIntegralType; ++Int) { 3681 QualType IntTy = ArithmeticTypes[Int]; 3682 AddBuiltinCandidate(IntTy, &IntTy, Args, 1, CandidateSet); 3683 } 3684 break; 3685 3686 case OO_New: 3687 case OO_Delete: 3688 case OO_Array_New: 3689 case OO_Array_Delete: 3690 case OO_Call: 3691 assert(false && "Special operators don't use AddBuiltinOperatorCandidates"); 3692 break; 3693 3694 case OO_Comma: 3695 UnaryAmp: 3696 case OO_Arrow: 3697 // C++ [over.match.oper]p3: 3698 // -- For the operator ',', the unary operator '&', or the 3699 // operator '->', the built-in candidates set is empty. 3700 break; 3701 3702 case OO_EqualEqual: 3703 case OO_ExclaimEqual: 3704 // C++ [over.match.oper]p16: 3705 // For every pointer to member type T, there exist candidate operator 3706 // functions of the form 3707 // 3708 // bool operator==(T,T); 3709 // bool operator!=(T,T); 3710 for (BuiltinCandidateTypeSet::iterator 3711 MemPtr = CandidateTypes.member_pointer_begin(), 3712 MemPtrEnd = CandidateTypes.member_pointer_end(); 3713 MemPtr != MemPtrEnd; 3714 ++MemPtr) { 3715 QualType ParamTypes[2] = { *MemPtr, *MemPtr }; 3716 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 3717 } 3718 3719 // Fall through 3720 3721 case OO_Less: 3722 case OO_Greater: 3723 case OO_LessEqual: 3724 case OO_GreaterEqual: 3725 // C++ [over.built]p15: 3726 // 3727 // For every pointer or enumeration type T, there exist 3728 // candidate operator functions of the form 3729 // 3730 // bool operator<(T, T); 3731 // bool operator>(T, T); 3732 // bool operator<=(T, T); 3733 // bool operator>=(T, T); 3734 // bool operator==(T, T); 3735 // bool operator!=(T, T); 3736 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3737 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3738 QualType ParamTypes[2] = { *Ptr, *Ptr }; 3739 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 3740 } 3741 for (BuiltinCandidateTypeSet::iterator Enum 3742 = CandidateTypes.enumeration_begin(); 3743 Enum != CandidateTypes.enumeration_end(); ++Enum) { 3744 QualType ParamTypes[2] = { *Enum, *Enum }; 3745 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 3746 } 3747 3748 // Fall through. 3749 isComparison = true; 3750 3751 BinaryPlus: 3752 BinaryMinus: 3753 if (!isComparison) { 3754 // We didn't fall through, so we must have OO_Plus or OO_Minus. 3755 3756 // C++ [over.built]p13: 3757 // 3758 // For every cv-qualified or cv-unqualified object type T 3759 // there exist candidate operator functions of the form 3760 // 3761 // T* operator+(T*, ptrdiff_t); 3762 // T& operator[](T*, ptrdiff_t); [BELOW] 3763 // T* operator-(T*, ptrdiff_t); 3764 // T* operator+(ptrdiff_t, T*); 3765 // T& operator[](ptrdiff_t, T*); [BELOW] 3766 // 3767 // C++ [over.built]p14: 3768 // 3769 // For every T, where T is a pointer to object type, there 3770 // exist candidate operator functions of the form 3771 // 3772 // ptrdiff_t operator-(T, T); 3773 for (BuiltinCandidateTypeSet::iterator Ptr 3774 = CandidateTypes.pointer_begin(); 3775 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3776 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 3777 3778 // operator+(T*, ptrdiff_t) or operator-(T*, ptrdiff_t) 3779 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3780 3781 if (Op == OO_Plus) { 3782 // T* operator+(ptrdiff_t, T*); 3783 ParamTypes[0] = ParamTypes[1]; 3784 ParamTypes[1] = *Ptr; 3785 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3786 } else { 3787 // ptrdiff_t operator-(T, T); 3788 ParamTypes[1] = *Ptr; 3789 AddBuiltinCandidate(Context.getPointerDiffType(), ParamTypes, 3790 Args, 2, CandidateSet); 3791 } 3792 } 3793 } 3794 // Fall through 3795 3796 case OO_Slash: 3797 BinaryStar: 3798 Conditional: 3799 // C++ [over.built]p12: 3800 // 3801 // For every pair of promoted arithmetic types L and R, there 3802 // exist candidate operator functions of the form 3803 // 3804 // LR operator*(L, R); 3805 // LR operator/(L, R); 3806 // LR operator+(L, R); 3807 // LR operator-(L, R); 3808 // bool operator<(L, R); 3809 // bool operator>(L, R); 3810 // bool operator<=(L, R); 3811 // bool operator>=(L, R); 3812 // bool operator==(L, R); 3813 // bool operator!=(L, R); 3814 // 3815 // where LR is the result of the usual arithmetic conversions 3816 // between types L and R. 3817 // 3818 // C++ [over.built]p24: 3819 // 3820 // For every pair of promoted arithmetic types L and R, there exist 3821 // candidate operator functions of the form 3822 // 3823 // LR operator?(bool, L, R); 3824 // 3825 // where LR is the result of the usual arithmetic conversions 3826 // between types L and R. 3827 // Our candidates ignore the first parameter. 3828 for (unsigned Left = FirstPromotedArithmeticType; 3829 Left < LastPromotedArithmeticType; ++Left) { 3830 for (unsigned Right = FirstPromotedArithmeticType; 3831 Right < LastPromotedArithmeticType; ++Right) { 3832 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 3833 QualType Result 3834 = isComparison 3835 ? Context.BoolTy 3836 : Context.UsualArithmeticConversionsType(LandR[0], LandR[1]); 3837 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 3838 } 3839 } 3840 break; 3841 3842 case OO_Percent: 3843 BinaryAmp: 3844 case OO_Caret: 3845 case OO_Pipe: 3846 case OO_LessLess: 3847 case OO_GreaterGreater: 3848 // C++ [over.built]p17: 3849 // 3850 // For every pair of promoted integral types L and R, there 3851 // exist candidate operator functions of the form 3852 // 3853 // LR operator%(L, R); 3854 // LR operator&(L, R); 3855 // LR operator^(L, R); 3856 // LR operator|(L, R); 3857 // L operator<<(L, R); 3858 // L operator>>(L, R); 3859 // 3860 // where LR is the result of the usual arithmetic conversions 3861 // between types L and R. 3862 for (unsigned Left = FirstPromotedIntegralType; 3863 Left < LastPromotedIntegralType; ++Left) { 3864 for (unsigned Right = FirstPromotedIntegralType; 3865 Right < LastPromotedIntegralType; ++Right) { 3866 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 3867 QualType Result = (Op == OO_LessLess || Op == OO_GreaterGreater) 3868 ? LandR[0] 3869 : Context.UsualArithmeticConversionsType(LandR[0], LandR[1]); 3870 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 3871 } 3872 } 3873 break; 3874 3875 case OO_Equal: 3876 // C++ [over.built]p20: 3877 // 3878 // For every pair (T, VQ), where T is an enumeration or 3879 // pointer to member type and VQ is either volatile or 3880 // empty, there exist candidate operator functions of the form 3881 // 3882 // VQ T& operator=(VQ T&, T); 3883 for (BuiltinCandidateTypeSet::iterator 3884 Enum = CandidateTypes.enumeration_begin(), 3885 EnumEnd = CandidateTypes.enumeration_end(); 3886 Enum != EnumEnd; ++Enum) 3887 AddBuiltinAssignmentOperatorCandidates(*this, *Enum, Args, 2, 3888 CandidateSet); 3889 for (BuiltinCandidateTypeSet::iterator 3890 MemPtr = CandidateTypes.member_pointer_begin(), 3891 MemPtrEnd = CandidateTypes.member_pointer_end(); 3892 MemPtr != MemPtrEnd; ++MemPtr) 3893 AddBuiltinAssignmentOperatorCandidates(*this, *MemPtr, Args, 2, 3894 CandidateSet); 3895 // Fall through. 3896 3897 case OO_PlusEqual: 3898 case OO_MinusEqual: 3899 // C++ [over.built]p19: 3900 // 3901 // For every pair (T, VQ), where T is any type and VQ is either 3902 // volatile or empty, there exist candidate operator functions 3903 // of the form 3904 // 3905 // T*VQ& operator=(T*VQ&, T*); 3906 // 3907 // C++ [over.built]p21: 3908 // 3909 // For every pair (T, VQ), where T is a cv-qualified or 3910 // cv-unqualified object type and VQ is either volatile or 3911 // empty, there exist candidate operator functions of the form 3912 // 3913 // T*VQ& operator+=(T*VQ&, ptrdiff_t); 3914 // T*VQ& operator-=(T*VQ&, ptrdiff_t); 3915 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3916 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3917 QualType ParamTypes[2]; 3918 ParamTypes[1] = (Op == OO_Equal)? *Ptr : Context.getPointerDiffType(); 3919 3920 // non-volatile version 3921 ParamTypes[0] = Context.getLValueReferenceType(*Ptr); 3922 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3923 /*IsAssigmentOperator=*/Op == OO_Equal); 3924 3925 if (!Context.getCanonicalType(*Ptr).isVolatileQualified() && 3926 VisibleTypeConversionsQuals.hasVolatile()) { 3927 // volatile version 3928 ParamTypes[0] 3929 = Context.getLValueReferenceType(Context.getVolatileType(*Ptr)); 3930 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3931 /*IsAssigmentOperator=*/Op == OO_Equal); 3932 } 3933 } 3934 // Fall through. 3935 3936 case OO_StarEqual: 3937 case OO_SlashEqual: 3938 // C++ [over.built]p18: 3939 // 3940 // For every triple (L, VQ, R), where L is an arithmetic type, 3941 // VQ is either volatile or empty, and R is a promoted 3942 // arithmetic type, there exist candidate operator functions of 3943 // the form 3944 // 3945 // VQ L& operator=(VQ L&, R); 3946 // VQ L& operator*=(VQ L&, R); 3947 // VQ L& operator/=(VQ L&, R); 3948 // VQ L& operator+=(VQ L&, R); 3949 // VQ L& operator-=(VQ L&, R); 3950 for (unsigned Left = 0; Left < NumArithmeticTypes; ++Left) { 3951 for (unsigned Right = FirstPromotedArithmeticType; 3952 Right < LastPromotedArithmeticType; ++Right) { 3953 QualType ParamTypes[2]; 3954 ParamTypes[1] = ArithmeticTypes[Right]; 3955 3956 // Add this built-in operator as a candidate (VQ is empty). 3957 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 3958 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3959 /*IsAssigmentOperator=*/Op == OO_Equal); 3960 3961 // Add this built-in operator as a candidate (VQ is 'volatile'). 3962 if (VisibleTypeConversionsQuals.hasVolatile()) { 3963 ParamTypes[0] = Context.getVolatileType(ArithmeticTypes[Left]); 3964 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 3965 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3966 /*IsAssigmentOperator=*/Op == OO_Equal); 3967 } 3968 } 3969 } 3970 break; 3971 3972 case OO_PercentEqual: 3973 case OO_LessLessEqual: 3974 case OO_GreaterGreaterEqual: 3975 case OO_AmpEqual: 3976 case OO_CaretEqual: 3977 case OO_PipeEqual: 3978 // C++ [over.built]p22: 3979 // 3980 // For every triple (L, VQ, R), where L is an integral type, VQ 3981 // is either volatile or empty, and R is a promoted integral 3982 // type, there exist candidate operator functions of the form 3983 // 3984 // VQ L& operator%=(VQ L&, R); 3985 // VQ L& operator<<=(VQ L&, R); 3986 // VQ L& operator>>=(VQ L&, R); 3987 // VQ L& operator&=(VQ L&, R); 3988 // VQ L& operator^=(VQ L&, R); 3989 // VQ L& operator|=(VQ L&, R); 3990 for (unsigned Left = FirstIntegralType; Left < LastIntegralType; ++Left) { 3991 for (unsigned Right = FirstPromotedIntegralType; 3992 Right < LastPromotedIntegralType; ++Right) { 3993 QualType ParamTypes[2]; 3994 ParamTypes[1] = ArithmeticTypes[Right]; 3995 3996 // Add this built-in operator as a candidate (VQ is empty). 3997 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 3998 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 3999 if (VisibleTypeConversionsQuals.hasVolatile()) { 4000 // Add this built-in operator as a candidate (VQ is 'volatile'). 4001 ParamTypes[0] = ArithmeticTypes[Left]; 4002 ParamTypes[0] = Context.getVolatileType(ParamTypes[0]); 4003 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 4004 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 4005 } 4006 } 4007 } 4008 break; 4009 4010 case OO_Exclaim: { 4011 // C++ [over.operator]p23: 4012 // 4013 // There also exist candidate operator functions of the form 4014 // 4015 // bool operator!(bool); 4016 // bool operator&&(bool, bool); [BELOW] 4017 // bool operator||(bool, bool); [BELOW] 4018 QualType ParamTy = Context.BoolTy; 4019 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet, 4020 /*IsAssignmentOperator=*/false, 4021 /*NumContextualBoolArguments=*/1); 4022 break; 4023 } 4024 4025 case OO_AmpAmp: 4026 case OO_PipePipe: { 4027 // C++ [over.operator]p23: 4028 // 4029 // There also exist candidate operator functions of the form 4030 // 4031 // bool operator!(bool); [ABOVE] 4032 // bool operator&&(bool, bool); 4033 // bool operator||(bool, bool); 4034 QualType ParamTypes[2] = { Context.BoolTy, Context.BoolTy }; 4035 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet, 4036 /*IsAssignmentOperator=*/false, 4037 /*NumContextualBoolArguments=*/2); 4038 break; 4039 } 4040 4041 case OO_Subscript: 4042 // C++ [over.built]p13: 4043 // 4044 // For every cv-qualified or cv-unqualified object type T there 4045 // exist candidate operator functions of the form 4046 // 4047 // T* operator+(T*, ptrdiff_t); [ABOVE] 4048 // T& operator[](T*, ptrdiff_t); 4049 // T* operator-(T*, ptrdiff_t); [ABOVE] 4050 // T* operator+(ptrdiff_t, T*); [ABOVE] 4051 // T& operator[](ptrdiff_t, T*); 4052 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 4053 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4054 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 4055 QualType PointeeType = (*Ptr)->getAs<PointerType>()->getPointeeType(); 4056 QualType ResultTy = Context.getLValueReferenceType(PointeeType); 4057 4058 // T& operator[](T*, ptrdiff_t) 4059 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 4060 4061 // T& operator[](ptrdiff_t, T*); 4062 ParamTypes[0] = ParamTypes[1]; 4063 ParamTypes[1] = *Ptr; 4064 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 4065 } 4066 break; 4067 4068 case OO_ArrowStar: 4069 // C++ [over.built]p11: 4070 // For every quintuple (C1, C2, T, CV1, CV2), where C2 is a class type, 4071 // C1 is the same type as C2 or is a derived class of C2, T is an object 4072 // type or a function type, and CV1 and CV2 are cv-qualifier-seqs, 4073 // there exist candidate operator functions of the form 4074 // CV12 T& operator->*(CV1 C1*, CV2 T C2::*); 4075 // where CV12 is the union of CV1 and CV2. 4076 { 4077 for (BuiltinCandidateTypeSet::iterator Ptr = 4078 CandidateTypes.pointer_begin(); 4079 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4080 QualType C1Ty = (*Ptr); 4081 QualType C1; 4082 QualifierCollector Q1; 4083 if (const PointerType *PointerTy = C1Ty->getAs<PointerType>()) { 4084 C1 = QualType(Q1.strip(PointerTy->getPointeeType()), 0); 4085 if (!isa<RecordType>(C1)) 4086 continue; 4087 // heuristic to reduce number of builtin candidates in the set. 4088 // Add volatile/restrict version only if there are conversions to a 4089 // volatile/restrict type. 4090 if (!VisibleTypeConversionsQuals.hasVolatile() && Q1.hasVolatile()) 4091 continue; 4092 if (!VisibleTypeConversionsQuals.hasRestrict() && Q1.hasRestrict()) 4093 continue; 4094 } 4095 for (BuiltinCandidateTypeSet::iterator 4096 MemPtr = CandidateTypes.member_pointer_begin(), 4097 MemPtrEnd = CandidateTypes.member_pointer_end(); 4098 MemPtr != MemPtrEnd; ++MemPtr) { 4099 const MemberPointerType *mptr = cast<MemberPointerType>(*MemPtr); 4100 QualType C2 = QualType(mptr->getClass(), 0); 4101 C2 = C2.getUnqualifiedType(); 4102 if (C1 != C2 && !IsDerivedFrom(C1, C2)) 4103 break; 4104 QualType ParamTypes[2] = { *Ptr, *MemPtr }; 4105 // build CV12 T& 4106 QualType T = mptr->getPointeeType(); 4107 if (!VisibleTypeConversionsQuals.hasVolatile() && 4108 T.isVolatileQualified()) 4109 continue; 4110 if (!VisibleTypeConversionsQuals.hasRestrict() && 4111 T.isRestrictQualified()) 4112 continue; 4113 T = Q1.apply(T); 4114 QualType ResultTy = Context.getLValueReferenceType(T); 4115 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 4116 } 4117 } 4118 } 4119 break; 4120 4121 case OO_Conditional: 4122 // Note that we don't consider the first argument, since it has been 4123 // contextually converted to bool long ago. The candidates below are 4124 // therefore added as binary. 4125 // 4126 // C++ [over.built]p24: 4127 // For every type T, where T is a pointer or pointer-to-member type, 4128 // there exist candidate operator functions of the form 4129 // 4130 // T operator?(bool, T, T); 4131 // 4132 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(), 4133 E = CandidateTypes.pointer_end(); Ptr != E; ++Ptr) { 4134 QualType ParamTypes[2] = { *Ptr, *Ptr }; 4135 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 4136 } 4137 for (BuiltinCandidateTypeSet::iterator Ptr = 4138 CandidateTypes.member_pointer_begin(), 4139 E = CandidateTypes.member_pointer_end(); Ptr != E; ++Ptr) { 4140 QualType ParamTypes[2] = { *Ptr, *Ptr }; 4141 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 4142 } 4143 goto Conditional; 4144 } 4145} 4146 4147/// \brief Add function candidates found via argument-dependent lookup 4148/// to the set of overloading candidates. 4149/// 4150/// This routine performs argument-dependent name lookup based on the 4151/// given function name (which may also be an operator name) and adds 4152/// all of the overload candidates found by ADL to the overload 4153/// candidate set (C++ [basic.lookup.argdep]). 4154void 4155Sema::AddArgumentDependentLookupCandidates(DeclarationName Name, 4156 bool Operator, 4157 Expr **Args, unsigned NumArgs, 4158 const TemplateArgumentListInfo *ExplicitTemplateArgs, 4159 OverloadCandidateSet& CandidateSet, 4160 bool PartialOverloading) { 4161 ADLResult Fns; 4162 4163 // FIXME: This approach for uniquing ADL results (and removing 4164 // redundant candidates from the set) relies on pointer-equality, 4165 // which means we need to key off the canonical decl. However, 4166 // always going back to the canonical decl might not get us the 4167 // right set of default arguments. What default arguments are 4168 // we supposed to consider on ADL candidates, anyway? 4169 4170 // FIXME: Pass in the explicit template arguments? 4171 ArgumentDependentLookup(Name, Operator, Args, NumArgs, Fns); 4172 4173 // Erase all of the candidates we already knew about. 4174 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 4175 CandEnd = CandidateSet.end(); 4176 Cand != CandEnd; ++Cand) 4177 if (Cand->Function) { 4178 Fns.erase(Cand->Function); 4179 if (FunctionTemplateDecl *FunTmpl = Cand->Function->getPrimaryTemplate()) 4180 Fns.erase(FunTmpl); 4181 } 4182 4183 // For each of the ADL candidates we found, add it to the overload 4184 // set. 4185 for (ADLResult::iterator I = Fns.begin(), E = Fns.end(); I != E; ++I) { 4186 DeclAccessPair FoundDecl = DeclAccessPair::make(*I, AS_none); 4187 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*I)) { 4188 if (ExplicitTemplateArgs) 4189 continue; 4190 4191 AddOverloadCandidate(FD, FoundDecl, Args, NumArgs, CandidateSet, 4192 false, false, PartialOverloading); 4193 } else 4194 AddTemplateOverloadCandidate(cast<FunctionTemplateDecl>(*I), 4195 FoundDecl, ExplicitTemplateArgs, 4196 Args, NumArgs, CandidateSet); 4197 } 4198} 4199 4200/// isBetterOverloadCandidate - Determines whether the first overload 4201/// candidate is a better candidate than the second (C++ 13.3.3p1). 4202bool 4203Sema::isBetterOverloadCandidate(const OverloadCandidate& Cand1, 4204 const OverloadCandidate& Cand2, 4205 SourceLocation Loc) { 4206 // Define viable functions to be better candidates than non-viable 4207 // functions. 4208 if (!Cand2.Viable) 4209 return Cand1.Viable; 4210 else if (!Cand1.Viable) 4211 return false; 4212 4213 // C++ [over.match.best]p1: 4214 // 4215 // -- if F is a static member function, ICS1(F) is defined such 4216 // that ICS1(F) is neither better nor worse than ICS1(G) for 4217 // any function G, and, symmetrically, ICS1(G) is neither 4218 // better nor worse than ICS1(F). 4219 unsigned StartArg = 0; 4220 if (Cand1.IgnoreObjectArgument || Cand2.IgnoreObjectArgument) 4221 StartArg = 1; 4222 4223 // C++ [over.match.best]p1: 4224 // A viable function F1 is defined to be a better function than another 4225 // viable function F2 if for all arguments i, ICSi(F1) is not a worse 4226 // conversion sequence than ICSi(F2), and then... 4227 unsigned NumArgs = Cand1.Conversions.size(); 4228 assert(Cand2.Conversions.size() == NumArgs && "Overload candidate mismatch"); 4229 bool HasBetterConversion = false; 4230 for (unsigned ArgIdx = StartArg; ArgIdx < NumArgs; ++ArgIdx) { 4231 switch (CompareImplicitConversionSequences(Cand1.Conversions[ArgIdx], 4232 Cand2.Conversions[ArgIdx])) { 4233 case ImplicitConversionSequence::Better: 4234 // Cand1 has a better conversion sequence. 4235 HasBetterConversion = true; 4236 break; 4237 4238 case ImplicitConversionSequence::Worse: 4239 // Cand1 can't be better than Cand2. 4240 return false; 4241 4242 case ImplicitConversionSequence::Indistinguishable: 4243 // Do nothing. 4244 break; 4245 } 4246 } 4247 4248 // -- for some argument j, ICSj(F1) is a better conversion sequence than 4249 // ICSj(F2), or, if not that, 4250 if (HasBetterConversion) 4251 return true; 4252 4253 // - F1 is a non-template function and F2 is a function template 4254 // specialization, or, if not that, 4255 if (Cand1.Function && !Cand1.Function->getPrimaryTemplate() && 4256 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 4257 return true; 4258 4259 // -- F1 and F2 are function template specializations, and the function 4260 // template for F1 is more specialized than the template for F2 4261 // according to the partial ordering rules described in 14.5.5.2, or, 4262 // if not that, 4263 if (Cand1.Function && Cand1.Function->getPrimaryTemplate() && 4264 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 4265 if (FunctionTemplateDecl *BetterTemplate 4266 = getMoreSpecializedTemplate(Cand1.Function->getPrimaryTemplate(), 4267 Cand2.Function->getPrimaryTemplate(), 4268 Loc, 4269 isa<CXXConversionDecl>(Cand1.Function)? TPOC_Conversion 4270 : TPOC_Call)) 4271 return BetterTemplate == Cand1.Function->getPrimaryTemplate(); 4272 4273 // -- the context is an initialization by user-defined conversion 4274 // (see 8.5, 13.3.1.5) and the standard conversion sequence 4275 // from the return type of F1 to the destination type (i.e., 4276 // the type of the entity being initialized) is a better 4277 // conversion sequence than the standard conversion sequence 4278 // from the return type of F2 to the destination type. 4279 if (Cand1.Function && Cand2.Function && 4280 isa<CXXConversionDecl>(Cand1.Function) && 4281 isa<CXXConversionDecl>(Cand2.Function)) { 4282 switch (CompareStandardConversionSequences(Cand1.FinalConversion, 4283 Cand2.FinalConversion)) { 4284 case ImplicitConversionSequence::Better: 4285 // Cand1 has a better conversion sequence. 4286 return true; 4287 4288 case ImplicitConversionSequence::Worse: 4289 // Cand1 can't be better than Cand2. 4290 return false; 4291 4292 case ImplicitConversionSequence::Indistinguishable: 4293 // Do nothing 4294 break; 4295 } 4296 } 4297 4298 return false; 4299} 4300 4301/// \brief Computes the best viable function (C++ 13.3.3) 4302/// within an overload candidate set. 4303/// 4304/// \param CandidateSet the set of candidate functions. 4305/// 4306/// \param Loc the location of the function name (or operator symbol) for 4307/// which overload resolution occurs. 4308/// 4309/// \param Best f overload resolution was successful or found a deleted 4310/// function, Best points to the candidate function found. 4311/// 4312/// \returns The result of overload resolution. 4313OverloadingResult Sema::BestViableFunction(OverloadCandidateSet& CandidateSet, 4314 SourceLocation Loc, 4315 OverloadCandidateSet::iterator& Best) { 4316 // Find the best viable function. 4317 Best = CandidateSet.end(); 4318 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 4319 Cand != CandidateSet.end(); ++Cand) { 4320 if (Cand->Viable) { 4321 if (Best == CandidateSet.end() || 4322 isBetterOverloadCandidate(*Cand, *Best, Loc)) 4323 Best = Cand; 4324 } 4325 } 4326 4327 // If we didn't find any viable functions, abort. 4328 if (Best == CandidateSet.end()) 4329 return OR_No_Viable_Function; 4330 4331 // Make sure that this function is better than every other viable 4332 // function. If not, we have an ambiguity. 4333 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 4334 Cand != CandidateSet.end(); ++Cand) { 4335 if (Cand->Viable && 4336 Cand != Best && 4337 !isBetterOverloadCandidate(*Best, *Cand, Loc)) { 4338 Best = CandidateSet.end(); 4339 return OR_Ambiguous; 4340 } 4341 } 4342 4343 // Best is the best viable function. 4344 if (Best->Function && 4345 (Best->Function->isDeleted() || 4346 Best->Function->getAttr<UnavailableAttr>())) 4347 return OR_Deleted; 4348 4349 // C++ [basic.def.odr]p2: 4350 // An overloaded function is used if it is selected by overload resolution 4351 // when referred to from a potentially-evaluated expression. [Note: this 4352 // covers calls to named functions (5.2.2), operator overloading 4353 // (clause 13), user-defined conversions (12.3.2), allocation function for 4354 // placement new (5.3.4), as well as non-default initialization (8.5). 4355 if (Best->Function) 4356 MarkDeclarationReferenced(Loc, Best->Function); 4357 return OR_Success; 4358} 4359 4360namespace { 4361 4362enum OverloadCandidateKind { 4363 oc_function, 4364 oc_method, 4365 oc_constructor, 4366 oc_function_template, 4367 oc_method_template, 4368 oc_constructor_template, 4369 oc_implicit_default_constructor, 4370 oc_implicit_copy_constructor, 4371 oc_implicit_copy_assignment 4372}; 4373 4374OverloadCandidateKind ClassifyOverloadCandidate(Sema &S, 4375 FunctionDecl *Fn, 4376 std::string &Description) { 4377 bool isTemplate = false; 4378 4379 if (FunctionTemplateDecl *FunTmpl = Fn->getPrimaryTemplate()) { 4380 isTemplate = true; 4381 Description = S.getTemplateArgumentBindingsText( 4382 FunTmpl->getTemplateParameters(), *Fn->getTemplateSpecializationArgs()); 4383 } 4384 4385 if (CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(Fn)) { 4386 if (!Ctor->isImplicit()) 4387 return isTemplate ? oc_constructor_template : oc_constructor; 4388 4389 return Ctor->isCopyConstructor() ? oc_implicit_copy_constructor 4390 : oc_implicit_default_constructor; 4391 } 4392 4393 if (CXXMethodDecl *Meth = dyn_cast<CXXMethodDecl>(Fn)) { 4394 // This actually gets spelled 'candidate function' for now, but 4395 // it doesn't hurt to split it out. 4396 if (!Meth->isImplicit()) 4397 return isTemplate ? oc_method_template : oc_method; 4398 4399 assert(Meth->isCopyAssignment() 4400 && "implicit method is not copy assignment operator?"); 4401 return oc_implicit_copy_assignment; 4402 } 4403 4404 return isTemplate ? oc_function_template : oc_function; 4405} 4406 4407} // end anonymous namespace 4408 4409// Notes the location of an overload candidate. 4410void Sema::NoteOverloadCandidate(FunctionDecl *Fn) { 4411 std::string FnDesc; 4412 OverloadCandidateKind K = ClassifyOverloadCandidate(*this, Fn, FnDesc); 4413 Diag(Fn->getLocation(), diag::note_ovl_candidate) 4414 << (unsigned) K << FnDesc; 4415} 4416 4417/// Diagnoses an ambiguous conversion. The partial diagnostic is the 4418/// "lead" diagnostic; it will be given two arguments, the source and 4419/// target types of the conversion. 4420void Sema::DiagnoseAmbiguousConversion(const ImplicitConversionSequence &ICS, 4421 SourceLocation CaretLoc, 4422 const PartialDiagnostic &PDiag) { 4423 Diag(CaretLoc, PDiag) 4424 << ICS.Ambiguous.getFromType() << ICS.Ambiguous.getToType(); 4425 for (AmbiguousConversionSequence::const_iterator 4426 I = ICS.Ambiguous.begin(), E = ICS.Ambiguous.end(); I != E; ++I) { 4427 NoteOverloadCandidate(*I); 4428 } 4429} 4430 4431namespace { 4432 4433void DiagnoseBadConversion(Sema &S, OverloadCandidate *Cand, unsigned I) { 4434 const ImplicitConversionSequence &Conv = Cand->Conversions[I]; 4435 assert(Conv.isBad()); 4436 assert(Cand->Function && "for now, candidate must be a function"); 4437 FunctionDecl *Fn = Cand->Function; 4438 4439 // There's a conversion slot for the object argument if this is a 4440 // non-constructor method. Note that 'I' corresponds the 4441 // conversion-slot index. 4442 bool isObjectArgument = false; 4443 if (isa<CXXMethodDecl>(Fn) && !isa<CXXConstructorDecl>(Fn)) { 4444 if (I == 0) 4445 isObjectArgument = true; 4446 else 4447 I--; 4448 } 4449 4450 std::string FnDesc; 4451 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, FnDesc); 4452 4453 Expr *FromExpr = Conv.Bad.FromExpr; 4454 QualType FromTy = Conv.Bad.getFromType(); 4455 QualType ToTy = Conv.Bad.getToType(); 4456 4457 if (FromTy == S.Context.OverloadTy) { 4458 assert(FromExpr && "overload set argument came from implicit argument?"); 4459 Expr *E = FromExpr->IgnoreParens(); 4460 if (isa<UnaryOperator>(E)) 4461 E = cast<UnaryOperator>(E)->getSubExpr()->IgnoreParens(); 4462 DeclarationName Name = cast<OverloadExpr>(E)->getName(); 4463 4464 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_overload) 4465 << (unsigned) FnKind << FnDesc 4466 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 4467 << ToTy << Name << I+1; 4468 return; 4469 } 4470 4471 // Do some hand-waving analysis to see if the non-viability is due 4472 // to a qualifier mismatch. 4473 CanQualType CFromTy = S.Context.getCanonicalType(FromTy); 4474 CanQualType CToTy = S.Context.getCanonicalType(ToTy); 4475 if (CanQual<ReferenceType> RT = CToTy->getAs<ReferenceType>()) 4476 CToTy = RT->getPointeeType(); 4477 else { 4478 // TODO: detect and diagnose the full richness of const mismatches. 4479 if (CanQual<PointerType> FromPT = CFromTy->getAs<PointerType>()) 4480 if (CanQual<PointerType> ToPT = CToTy->getAs<PointerType>()) 4481 CFromTy = FromPT->getPointeeType(), CToTy = ToPT->getPointeeType(); 4482 } 4483 4484 if (CToTy.getUnqualifiedType() == CFromTy.getUnqualifiedType() && 4485 !CToTy.isAtLeastAsQualifiedAs(CFromTy)) { 4486 // It is dumb that we have to do this here. 4487 while (isa<ArrayType>(CFromTy)) 4488 CFromTy = CFromTy->getAs<ArrayType>()->getElementType(); 4489 while (isa<ArrayType>(CToTy)) 4490 CToTy = CFromTy->getAs<ArrayType>()->getElementType(); 4491 4492 Qualifiers FromQs = CFromTy.getQualifiers(); 4493 Qualifiers ToQs = CToTy.getQualifiers(); 4494 4495 if (FromQs.getAddressSpace() != ToQs.getAddressSpace()) { 4496 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_addrspace) 4497 << (unsigned) FnKind << FnDesc 4498 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 4499 << FromTy 4500 << FromQs.getAddressSpace() << ToQs.getAddressSpace() 4501 << (unsigned) isObjectArgument << I+1; 4502 return; 4503 } 4504 4505 unsigned CVR = FromQs.getCVRQualifiers() & ~ToQs.getCVRQualifiers(); 4506 assert(CVR && "unexpected qualifiers mismatch"); 4507 4508 if (isObjectArgument) { 4509 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr_this) 4510 << (unsigned) FnKind << FnDesc 4511 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 4512 << FromTy << (CVR - 1); 4513 } else { 4514 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr) 4515 << (unsigned) FnKind << FnDesc 4516 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 4517 << FromTy << (CVR - 1) << I+1; 4518 } 4519 return; 4520 } 4521 4522 // Diagnose references or pointers to incomplete types differently, 4523 // since it's far from impossible that the incompleteness triggered 4524 // the failure. 4525 QualType TempFromTy = FromTy.getNonReferenceType(); 4526 if (const PointerType *PTy = TempFromTy->getAs<PointerType>()) 4527 TempFromTy = PTy->getPointeeType(); 4528 if (TempFromTy->isIncompleteType()) { 4529 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_conv_incomplete) 4530 << (unsigned) FnKind << FnDesc 4531 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 4532 << FromTy << ToTy << (unsigned) isObjectArgument << I+1; 4533 return; 4534 } 4535 4536 // TODO: specialize more based on the kind of mismatch 4537 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_conv) 4538 << (unsigned) FnKind << FnDesc 4539 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 4540 << FromTy << ToTy << (unsigned) isObjectArgument << I+1; 4541} 4542 4543void DiagnoseArityMismatch(Sema &S, OverloadCandidate *Cand, 4544 unsigned NumFormalArgs) { 4545 // TODO: treat calls to a missing default constructor as a special case 4546 4547 FunctionDecl *Fn = Cand->Function; 4548 const FunctionProtoType *FnTy = Fn->getType()->getAs<FunctionProtoType>(); 4549 4550 unsigned MinParams = Fn->getMinRequiredArguments(); 4551 4552 // at least / at most / exactly 4553 unsigned mode, modeCount; 4554 if (NumFormalArgs < MinParams) { 4555 assert(Cand->FailureKind == ovl_fail_too_few_arguments); 4556 if (MinParams != FnTy->getNumArgs() || FnTy->isVariadic()) 4557 mode = 0; // "at least" 4558 else 4559 mode = 2; // "exactly" 4560 modeCount = MinParams; 4561 } else { 4562 assert(Cand->FailureKind == ovl_fail_too_many_arguments); 4563 if (MinParams != FnTy->getNumArgs()) 4564 mode = 1; // "at most" 4565 else 4566 mode = 2; // "exactly" 4567 modeCount = FnTy->getNumArgs(); 4568 } 4569 4570 std::string Description; 4571 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, Description); 4572 4573 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_arity) 4574 << (unsigned) FnKind << Description << mode << modeCount << NumFormalArgs; 4575} 4576 4577/// Diagnose a failed template-argument deduction. 4578void DiagnoseBadDeduction(Sema &S, OverloadCandidate *Cand, 4579 Expr **Args, unsigned NumArgs) { 4580 FunctionDecl *Fn = Cand->Function; // pattern 4581 4582 TemplateParameter Param = TemplateParameter::getFromOpaqueValue( 4583 Cand->DeductionFailure.TemplateParameter); 4584 4585 switch (Cand->DeductionFailure.Result) { 4586 case Sema::TDK_Success: 4587 llvm_unreachable("TDK_success while diagnosing bad deduction"); 4588 4589 case Sema::TDK_Incomplete: { 4590 NamedDecl *ParamD; 4591 (ParamD = Param.dyn_cast<TemplateTypeParmDecl*>()) || 4592 (ParamD = Param.dyn_cast<NonTypeTemplateParmDecl*>()) || 4593 (ParamD = Param.dyn_cast<TemplateTemplateParmDecl*>()); 4594 assert(ParamD && "no parameter found for incomplete deduction result"); 4595 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_incomplete_deduction) 4596 << ParamD->getDeclName(); 4597 return; 4598 } 4599 4600 // TODO: diagnose these individually, then kill off 4601 // note_ovl_candidate_bad_deduction, which is uselessly vague. 4602 case Sema::TDK_InstantiationDepth: 4603 case Sema::TDK_Inconsistent: 4604 case Sema::TDK_InconsistentQuals: 4605 case Sema::TDK_SubstitutionFailure: 4606 case Sema::TDK_NonDeducedMismatch: 4607 case Sema::TDK_TooManyArguments: 4608 case Sema::TDK_TooFewArguments: 4609 case Sema::TDK_InvalidExplicitArguments: 4610 case Sema::TDK_FailedOverloadResolution: 4611 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_deduction); 4612 return; 4613 } 4614} 4615 4616/// Generates a 'note' diagnostic for an overload candidate. We've 4617/// already generated a primary error at the call site. 4618/// 4619/// It really does need to be a single diagnostic with its caret 4620/// pointed at the candidate declaration. Yes, this creates some 4621/// major challenges of technical writing. Yes, this makes pointing 4622/// out problems with specific arguments quite awkward. It's still 4623/// better than generating twenty screens of text for every failed 4624/// overload. 4625/// 4626/// It would be great to be able to express per-candidate problems 4627/// more richly for those diagnostic clients that cared, but we'd 4628/// still have to be just as careful with the default diagnostics. 4629void NoteFunctionCandidate(Sema &S, OverloadCandidate *Cand, 4630 Expr **Args, unsigned NumArgs) { 4631 FunctionDecl *Fn = Cand->Function; 4632 4633 // Note deleted candidates, but only if they're viable. 4634 if (Cand->Viable && (Fn->isDeleted() || Fn->hasAttr<UnavailableAttr>())) { 4635 std::string FnDesc; 4636 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, FnDesc); 4637 4638 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_deleted) 4639 << FnKind << FnDesc << Fn->isDeleted(); 4640 return; 4641 } 4642 4643 // We don't really have anything else to say about viable candidates. 4644 if (Cand->Viable) { 4645 S.NoteOverloadCandidate(Fn); 4646 return; 4647 } 4648 4649 switch (Cand->FailureKind) { 4650 case ovl_fail_too_many_arguments: 4651 case ovl_fail_too_few_arguments: 4652 return DiagnoseArityMismatch(S, Cand, NumArgs); 4653 4654 case ovl_fail_bad_deduction: 4655 return DiagnoseBadDeduction(S, Cand, Args, NumArgs); 4656 4657 case ovl_fail_trivial_conversion: 4658 case ovl_fail_bad_final_conversion: 4659 return S.NoteOverloadCandidate(Fn); 4660 4661 case ovl_fail_bad_conversion: { 4662 unsigned I = (Cand->IgnoreObjectArgument ? 1 : 0); 4663 for (unsigned N = Cand->Conversions.size(); I != N; ++I) 4664 if (Cand->Conversions[I].isBad()) 4665 return DiagnoseBadConversion(S, Cand, I); 4666 4667 // FIXME: this currently happens when we're called from SemaInit 4668 // when user-conversion overload fails. Figure out how to handle 4669 // those conditions and diagnose them well. 4670 return S.NoteOverloadCandidate(Fn); 4671 } 4672 } 4673} 4674 4675void NoteSurrogateCandidate(Sema &S, OverloadCandidate *Cand) { 4676 // Desugar the type of the surrogate down to a function type, 4677 // retaining as many typedefs as possible while still showing 4678 // the function type (and, therefore, its parameter types). 4679 QualType FnType = Cand->Surrogate->getConversionType(); 4680 bool isLValueReference = false; 4681 bool isRValueReference = false; 4682 bool isPointer = false; 4683 if (const LValueReferenceType *FnTypeRef = 4684 FnType->getAs<LValueReferenceType>()) { 4685 FnType = FnTypeRef->getPointeeType(); 4686 isLValueReference = true; 4687 } else if (const RValueReferenceType *FnTypeRef = 4688 FnType->getAs<RValueReferenceType>()) { 4689 FnType = FnTypeRef->getPointeeType(); 4690 isRValueReference = true; 4691 } 4692 if (const PointerType *FnTypePtr = FnType->getAs<PointerType>()) { 4693 FnType = FnTypePtr->getPointeeType(); 4694 isPointer = true; 4695 } 4696 // Desugar down to a function type. 4697 FnType = QualType(FnType->getAs<FunctionType>(), 0); 4698 // Reconstruct the pointer/reference as appropriate. 4699 if (isPointer) FnType = S.Context.getPointerType(FnType); 4700 if (isRValueReference) FnType = S.Context.getRValueReferenceType(FnType); 4701 if (isLValueReference) FnType = S.Context.getLValueReferenceType(FnType); 4702 4703 S.Diag(Cand->Surrogate->getLocation(), diag::note_ovl_surrogate_cand) 4704 << FnType; 4705} 4706 4707void NoteBuiltinOperatorCandidate(Sema &S, 4708 const char *Opc, 4709 SourceLocation OpLoc, 4710 OverloadCandidate *Cand) { 4711 assert(Cand->Conversions.size() <= 2 && "builtin operator is not binary"); 4712 std::string TypeStr("operator"); 4713 TypeStr += Opc; 4714 TypeStr += "("; 4715 TypeStr += Cand->BuiltinTypes.ParamTypes[0].getAsString(); 4716 if (Cand->Conversions.size() == 1) { 4717 TypeStr += ")"; 4718 S.Diag(OpLoc, diag::note_ovl_builtin_unary_candidate) << TypeStr; 4719 } else { 4720 TypeStr += ", "; 4721 TypeStr += Cand->BuiltinTypes.ParamTypes[1].getAsString(); 4722 TypeStr += ")"; 4723 S.Diag(OpLoc, diag::note_ovl_builtin_binary_candidate) << TypeStr; 4724 } 4725} 4726 4727void NoteAmbiguousUserConversions(Sema &S, SourceLocation OpLoc, 4728 OverloadCandidate *Cand) { 4729 unsigned NoOperands = Cand->Conversions.size(); 4730 for (unsigned ArgIdx = 0; ArgIdx < NoOperands; ++ArgIdx) { 4731 const ImplicitConversionSequence &ICS = Cand->Conversions[ArgIdx]; 4732 if (ICS.isBad()) break; // all meaningless after first invalid 4733 if (!ICS.isAmbiguous()) continue; 4734 4735 S.DiagnoseAmbiguousConversion(ICS, OpLoc, 4736 PDiag(diag::note_ambiguous_type_conversion)); 4737 } 4738} 4739 4740SourceLocation GetLocationForCandidate(const OverloadCandidate *Cand) { 4741 if (Cand->Function) 4742 return Cand->Function->getLocation(); 4743 if (Cand->IsSurrogate) 4744 return Cand->Surrogate->getLocation(); 4745 return SourceLocation(); 4746} 4747 4748struct CompareOverloadCandidatesForDisplay { 4749 Sema &S; 4750 CompareOverloadCandidatesForDisplay(Sema &S) : S(S) {} 4751 4752 bool operator()(const OverloadCandidate *L, 4753 const OverloadCandidate *R) { 4754 // Fast-path this check. 4755 if (L == R) return false; 4756 4757 // Order first by viability. 4758 if (L->Viable) { 4759 if (!R->Viable) return true; 4760 4761 // TODO: introduce a tri-valued comparison for overload 4762 // candidates. Would be more worthwhile if we had a sort 4763 // that could exploit it. 4764 if (S.isBetterOverloadCandidate(*L, *R, SourceLocation())) return true; 4765 if (S.isBetterOverloadCandidate(*R, *L, SourceLocation())) return false; 4766 } else if (R->Viable) 4767 return false; 4768 4769 assert(L->Viable == R->Viable); 4770 4771 // Criteria by which we can sort non-viable candidates: 4772 if (!L->Viable) { 4773 // 1. Arity mismatches come after other candidates. 4774 if (L->FailureKind == ovl_fail_too_many_arguments || 4775 L->FailureKind == ovl_fail_too_few_arguments) 4776 return false; 4777 if (R->FailureKind == ovl_fail_too_many_arguments || 4778 R->FailureKind == ovl_fail_too_few_arguments) 4779 return true; 4780 4781 // 2. Bad conversions come first and are ordered by the number 4782 // of bad conversions and quality of good conversions. 4783 if (L->FailureKind == ovl_fail_bad_conversion) { 4784 if (R->FailureKind != ovl_fail_bad_conversion) 4785 return true; 4786 4787 // If there's any ordering between the defined conversions... 4788 // FIXME: this might not be transitive. 4789 assert(L->Conversions.size() == R->Conversions.size()); 4790 4791 int leftBetter = 0; 4792 unsigned I = (L->IgnoreObjectArgument || R->IgnoreObjectArgument); 4793 for (unsigned E = L->Conversions.size(); I != E; ++I) { 4794 switch (S.CompareImplicitConversionSequences(L->Conversions[I], 4795 R->Conversions[I])) { 4796 case ImplicitConversionSequence::Better: 4797 leftBetter++; 4798 break; 4799 4800 case ImplicitConversionSequence::Worse: 4801 leftBetter--; 4802 break; 4803 4804 case ImplicitConversionSequence::Indistinguishable: 4805 break; 4806 } 4807 } 4808 if (leftBetter > 0) return true; 4809 if (leftBetter < 0) return false; 4810 4811 } else if (R->FailureKind == ovl_fail_bad_conversion) 4812 return false; 4813 4814 // TODO: others? 4815 } 4816 4817 // Sort everything else by location. 4818 SourceLocation LLoc = GetLocationForCandidate(L); 4819 SourceLocation RLoc = GetLocationForCandidate(R); 4820 4821 // Put candidates without locations (e.g. builtins) at the end. 4822 if (LLoc.isInvalid()) return false; 4823 if (RLoc.isInvalid()) return true; 4824 4825 return S.SourceMgr.isBeforeInTranslationUnit(LLoc, RLoc); 4826 } 4827}; 4828 4829/// CompleteNonViableCandidate - Normally, overload resolution only 4830/// computes up to the first 4831void CompleteNonViableCandidate(Sema &S, OverloadCandidate *Cand, 4832 Expr **Args, unsigned NumArgs) { 4833 assert(!Cand->Viable); 4834 4835 // Don't do anything on failures other than bad conversion. 4836 if (Cand->FailureKind != ovl_fail_bad_conversion) return; 4837 4838 // Skip forward to the first bad conversion. 4839 unsigned ConvIdx = (Cand->IgnoreObjectArgument ? 1 : 0); 4840 unsigned ConvCount = Cand->Conversions.size(); 4841 while (true) { 4842 assert(ConvIdx != ConvCount && "no bad conversion in candidate"); 4843 ConvIdx++; 4844 if (Cand->Conversions[ConvIdx - 1].isBad()) 4845 break; 4846 } 4847 4848 if (ConvIdx == ConvCount) 4849 return; 4850 4851 assert(!Cand->Conversions[ConvIdx].isInitialized() && 4852 "remaining conversion is initialized?"); 4853 4854 // FIXME: these should probably be preserved from the overload 4855 // operation somehow. 4856 bool SuppressUserConversions = false; 4857 bool ForceRValue = false; 4858 4859 const FunctionProtoType* Proto; 4860 unsigned ArgIdx = ConvIdx; 4861 4862 if (Cand->IsSurrogate) { 4863 QualType ConvType 4864 = Cand->Surrogate->getConversionType().getNonReferenceType(); 4865 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 4866 ConvType = ConvPtrType->getPointeeType(); 4867 Proto = ConvType->getAs<FunctionProtoType>(); 4868 ArgIdx--; 4869 } else if (Cand->Function) { 4870 Proto = Cand->Function->getType()->getAs<FunctionProtoType>(); 4871 if (isa<CXXMethodDecl>(Cand->Function) && 4872 !isa<CXXConstructorDecl>(Cand->Function)) 4873 ArgIdx--; 4874 } else { 4875 // Builtin binary operator with a bad first conversion. 4876 assert(ConvCount <= 3); 4877 for (; ConvIdx != ConvCount; ++ConvIdx) 4878 Cand->Conversions[ConvIdx] 4879 = S.TryCopyInitialization(Args[ConvIdx], 4880 Cand->BuiltinTypes.ParamTypes[ConvIdx], 4881 SuppressUserConversions, ForceRValue, 4882 /*InOverloadResolution*/ true); 4883 return; 4884 } 4885 4886 // Fill in the rest of the conversions. 4887 unsigned NumArgsInProto = Proto->getNumArgs(); 4888 for (; ConvIdx != ConvCount; ++ConvIdx, ++ArgIdx) { 4889 if (ArgIdx < NumArgsInProto) 4890 Cand->Conversions[ConvIdx] 4891 = S.TryCopyInitialization(Args[ArgIdx], Proto->getArgType(ArgIdx), 4892 SuppressUserConversions, ForceRValue, 4893 /*InOverloadResolution=*/true); 4894 else 4895 Cand->Conversions[ConvIdx].setEllipsis(); 4896 } 4897} 4898 4899} // end anonymous namespace 4900 4901/// PrintOverloadCandidates - When overload resolution fails, prints 4902/// diagnostic messages containing the candidates in the candidate 4903/// set. 4904void 4905Sema::PrintOverloadCandidates(OverloadCandidateSet& CandidateSet, 4906 OverloadCandidateDisplayKind OCD, 4907 Expr **Args, unsigned NumArgs, 4908 const char *Opc, 4909 SourceLocation OpLoc) { 4910 // Sort the candidates by viability and position. Sorting directly would 4911 // be prohibitive, so we make a set of pointers and sort those. 4912 llvm::SmallVector<OverloadCandidate*, 32> Cands; 4913 if (OCD == OCD_AllCandidates) Cands.reserve(CandidateSet.size()); 4914 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 4915 LastCand = CandidateSet.end(); 4916 Cand != LastCand; ++Cand) { 4917 if (Cand->Viable) 4918 Cands.push_back(Cand); 4919 else if (OCD == OCD_AllCandidates) { 4920 CompleteNonViableCandidate(*this, Cand, Args, NumArgs); 4921 Cands.push_back(Cand); 4922 } 4923 } 4924 4925 std::sort(Cands.begin(), Cands.end(), 4926 CompareOverloadCandidatesForDisplay(*this)); 4927 4928 bool ReportedAmbiguousConversions = false; 4929 4930 llvm::SmallVectorImpl<OverloadCandidate*>::iterator I, E; 4931 for (I = Cands.begin(), E = Cands.end(); I != E; ++I) { 4932 OverloadCandidate *Cand = *I; 4933 4934 if (Cand->Function) 4935 NoteFunctionCandidate(*this, Cand, Args, NumArgs); 4936 else if (Cand->IsSurrogate) 4937 NoteSurrogateCandidate(*this, Cand); 4938 4939 // This a builtin candidate. We do not, in general, want to list 4940 // every possible builtin candidate. 4941 else if (Cand->Viable) { 4942 // Generally we only see ambiguities including viable builtin 4943 // operators if overload resolution got screwed up by an 4944 // ambiguous user-defined conversion. 4945 // 4946 // FIXME: It's quite possible for different conversions to see 4947 // different ambiguities, though. 4948 if (!ReportedAmbiguousConversions) { 4949 NoteAmbiguousUserConversions(*this, OpLoc, Cand); 4950 ReportedAmbiguousConversions = true; 4951 } 4952 4953 // If this is a viable builtin, print it. 4954 NoteBuiltinOperatorCandidate(*this, Opc, OpLoc, Cand); 4955 } 4956 } 4957} 4958 4959static bool CheckUnresolvedAccess(Sema &S, OverloadExpr *E, DeclAccessPair D) { 4960 if (isa<UnresolvedLookupExpr>(E)) 4961 return S.CheckUnresolvedLookupAccess(cast<UnresolvedLookupExpr>(E), D); 4962 4963 return S.CheckUnresolvedMemberAccess(cast<UnresolvedMemberExpr>(E), D); 4964} 4965 4966/// ResolveAddressOfOverloadedFunction - Try to resolve the address of 4967/// an overloaded function (C++ [over.over]), where @p From is an 4968/// expression with overloaded function type and @p ToType is the type 4969/// we're trying to resolve to. For example: 4970/// 4971/// @code 4972/// int f(double); 4973/// int f(int); 4974/// 4975/// int (*pfd)(double) = f; // selects f(double) 4976/// @endcode 4977/// 4978/// This routine returns the resulting FunctionDecl if it could be 4979/// resolved, and NULL otherwise. When @p Complain is true, this 4980/// routine will emit diagnostics if there is an error. 4981FunctionDecl * 4982Sema::ResolveAddressOfOverloadedFunction(Expr *From, QualType ToType, 4983 bool Complain) { 4984 QualType FunctionType = ToType; 4985 bool IsMember = false; 4986 if (const PointerType *ToTypePtr = ToType->getAs<PointerType>()) 4987 FunctionType = ToTypePtr->getPointeeType(); 4988 else if (const ReferenceType *ToTypeRef = ToType->getAs<ReferenceType>()) 4989 FunctionType = ToTypeRef->getPointeeType(); 4990 else if (const MemberPointerType *MemTypePtr = 4991 ToType->getAs<MemberPointerType>()) { 4992 FunctionType = MemTypePtr->getPointeeType(); 4993 IsMember = true; 4994 } 4995 4996 // We only look at pointers or references to functions. 4997 FunctionType = Context.getCanonicalType(FunctionType).getUnqualifiedType(); 4998 if (!FunctionType->isFunctionType()) 4999 return 0; 5000 5001 // Find the actual overloaded function declaration. 5002 if (From->getType() != Context.OverloadTy) 5003 return 0; 5004 5005 // C++ [over.over]p1: 5006 // [...] [Note: any redundant set of parentheses surrounding the 5007 // overloaded function name is ignored (5.1). ] 5008 // C++ [over.over]p1: 5009 // [...] The overloaded function name can be preceded by the & 5010 // operator. 5011 OverloadExpr *OvlExpr = OverloadExpr::find(From).getPointer(); 5012 TemplateArgumentListInfo ETABuffer, *ExplicitTemplateArgs = 0; 5013 if (OvlExpr->hasExplicitTemplateArgs()) { 5014 OvlExpr->getExplicitTemplateArgs().copyInto(ETABuffer); 5015 ExplicitTemplateArgs = &ETABuffer; 5016 } 5017 5018 // Look through all of the overloaded functions, searching for one 5019 // whose type matches exactly. 5020 llvm::SmallVector<std::pair<DeclAccessPair, FunctionDecl*>, 4> Matches; 5021 bool FoundNonTemplateFunction = false; 5022 for (UnresolvedSetIterator I = OvlExpr->decls_begin(), 5023 E = OvlExpr->decls_end(); I != E; ++I) { 5024 // Look through any using declarations to find the underlying function. 5025 NamedDecl *Fn = (*I)->getUnderlyingDecl(); 5026 5027 // C++ [over.over]p3: 5028 // Non-member functions and static member functions match 5029 // targets of type "pointer-to-function" or "reference-to-function." 5030 // Nonstatic member functions match targets of 5031 // type "pointer-to-member-function." 5032 // Note that according to DR 247, the containing class does not matter. 5033 5034 if (FunctionTemplateDecl *FunctionTemplate 5035 = dyn_cast<FunctionTemplateDecl>(Fn)) { 5036 if (CXXMethodDecl *Method 5037 = dyn_cast<CXXMethodDecl>(FunctionTemplate->getTemplatedDecl())) { 5038 // Skip non-static function templates when converting to pointer, and 5039 // static when converting to member pointer. 5040 if (Method->isStatic() == IsMember) 5041 continue; 5042 } else if (IsMember) 5043 continue; 5044 5045 // C++ [over.over]p2: 5046 // If the name is a function template, template argument deduction is 5047 // done (14.8.2.2), and if the argument deduction succeeds, the 5048 // resulting template argument list is used to generate a single 5049 // function template specialization, which is added to the set of 5050 // overloaded functions considered. 5051 // FIXME: We don't really want to build the specialization here, do we? 5052 FunctionDecl *Specialization = 0; 5053 TemplateDeductionInfo Info(Context, OvlExpr->getNameLoc()); 5054 if (TemplateDeductionResult Result 5055 = DeduceTemplateArguments(FunctionTemplate, ExplicitTemplateArgs, 5056 FunctionType, Specialization, Info)) { 5057 // FIXME: make a note of the failed deduction for diagnostics. 5058 (void)Result; 5059 } else { 5060 // FIXME: If the match isn't exact, shouldn't we just drop this as 5061 // a candidate? Find a testcase before changing the code. 5062 assert(FunctionType 5063 == Context.getCanonicalType(Specialization->getType())); 5064 Matches.push_back(std::make_pair(I.getPair(), 5065 cast<FunctionDecl>(Specialization->getCanonicalDecl()))); 5066 } 5067 5068 continue; 5069 } 5070 5071 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 5072 // Skip non-static functions when converting to pointer, and static 5073 // when converting to member pointer. 5074 if (Method->isStatic() == IsMember) 5075 continue; 5076 5077 // If we have explicit template arguments, skip non-templates. 5078 if (OvlExpr->hasExplicitTemplateArgs()) 5079 continue; 5080 } else if (IsMember) 5081 continue; 5082 5083 if (FunctionDecl *FunDecl = dyn_cast<FunctionDecl>(Fn)) { 5084 QualType ResultTy; 5085 if (Context.hasSameUnqualifiedType(FunctionType, FunDecl->getType()) || 5086 IsNoReturnConversion(Context, FunDecl->getType(), FunctionType, 5087 ResultTy)) { 5088 Matches.push_back(std::make_pair(I.getPair(), 5089 cast<FunctionDecl>(FunDecl->getCanonicalDecl()))); 5090 FoundNonTemplateFunction = true; 5091 } 5092 } 5093 } 5094 5095 // If there were 0 or 1 matches, we're done. 5096 if (Matches.empty()) 5097 return 0; 5098 else if (Matches.size() == 1) { 5099 FunctionDecl *Result = Matches[0].second; 5100 MarkDeclarationReferenced(From->getLocStart(), Result); 5101 if (Complain) 5102 CheckUnresolvedAccess(*this, OvlExpr, Matches[0].first); 5103 return Result; 5104 } 5105 5106 // C++ [over.over]p4: 5107 // If more than one function is selected, [...] 5108 if (!FoundNonTemplateFunction) { 5109 // [...] and any given function template specialization F1 is 5110 // eliminated if the set contains a second function template 5111 // specialization whose function template is more specialized 5112 // than the function template of F1 according to the partial 5113 // ordering rules of 14.5.5.2. 5114 5115 // The algorithm specified above is quadratic. We instead use a 5116 // two-pass algorithm (similar to the one used to identify the 5117 // best viable function in an overload set) that identifies the 5118 // best function template (if it exists). 5119 5120 UnresolvedSet<4> MatchesCopy; // TODO: avoid! 5121 for (unsigned I = 0, E = Matches.size(); I != E; ++I) 5122 MatchesCopy.addDecl(Matches[I].second, Matches[I].first.getAccess()); 5123 5124 UnresolvedSetIterator Result = 5125 getMostSpecialized(MatchesCopy.begin(), MatchesCopy.end(), 5126 TPOC_Other, From->getLocStart(), 5127 PDiag(), 5128 PDiag(diag::err_addr_ovl_ambiguous) 5129 << Matches[0].second->getDeclName(), 5130 PDiag(diag::note_ovl_candidate) 5131 << (unsigned) oc_function_template); 5132 assert(Result != MatchesCopy.end() && "no most-specialized template"); 5133 MarkDeclarationReferenced(From->getLocStart(), *Result); 5134 if (Complain) { 5135 DeclAccessPair FoundDecl = Matches[Result - MatchesCopy.begin()].first; 5136 CheckUnresolvedAccess(*this, OvlExpr, FoundDecl); 5137 } 5138 return cast<FunctionDecl>(*Result); 5139 } 5140 5141 // [...] any function template specializations in the set are 5142 // eliminated if the set also contains a non-template function, [...] 5143 for (unsigned I = 0, N = Matches.size(); I != N; ) { 5144 if (Matches[I].second->getPrimaryTemplate() == 0) 5145 ++I; 5146 else { 5147 Matches[I] = Matches[--N]; 5148 Matches.set_size(N); 5149 } 5150 } 5151 5152 // [...] After such eliminations, if any, there shall remain exactly one 5153 // selected function. 5154 if (Matches.size() == 1) { 5155 MarkDeclarationReferenced(From->getLocStart(), Matches[0].second); 5156 if (Complain) 5157 CheckUnresolvedAccess(*this, OvlExpr, Matches[0].first); 5158 return cast<FunctionDecl>(Matches[0].second); 5159 } 5160 5161 // FIXME: We should probably return the same thing that BestViableFunction 5162 // returns (even if we issue the diagnostics here). 5163 Diag(From->getLocStart(), diag::err_addr_ovl_ambiguous) 5164 << Matches[0].second->getDeclName(); 5165 for (unsigned I = 0, E = Matches.size(); I != E; ++I) 5166 NoteOverloadCandidate(Matches[I].second); 5167 return 0; 5168} 5169 5170/// \brief Given an expression that refers to an overloaded function, try to 5171/// resolve that overloaded function expression down to a single function. 5172/// 5173/// This routine can only resolve template-ids that refer to a single function 5174/// template, where that template-id refers to a single template whose template 5175/// arguments are either provided by the template-id or have defaults, 5176/// as described in C++0x [temp.arg.explicit]p3. 5177FunctionDecl *Sema::ResolveSingleFunctionTemplateSpecialization(Expr *From) { 5178 // C++ [over.over]p1: 5179 // [...] [Note: any redundant set of parentheses surrounding the 5180 // overloaded function name is ignored (5.1). ] 5181 // C++ [over.over]p1: 5182 // [...] The overloaded function name can be preceded by the & 5183 // operator. 5184 5185 if (From->getType() != Context.OverloadTy) 5186 return 0; 5187 5188 OverloadExpr *OvlExpr = OverloadExpr::find(From).getPointer(); 5189 5190 // If we didn't actually find any template-ids, we're done. 5191 if (!OvlExpr->hasExplicitTemplateArgs()) 5192 return 0; 5193 5194 TemplateArgumentListInfo ExplicitTemplateArgs; 5195 OvlExpr->getExplicitTemplateArgs().copyInto(ExplicitTemplateArgs); 5196 5197 // Look through all of the overloaded functions, searching for one 5198 // whose type matches exactly. 5199 FunctionDecl *Matched = 0; 5200 for (UnresolvedSetIterator I = OvlExpr->decls_begin(), 5201 E = OvlExpr->decls_end(); I != E; ++I) { 5202 // C++0x [temp.arg.explicit]p3: 5203 // [...] In contexts where deduction is done and fails, or in contexts 5204 // where deduction is not done, if a template argument list is 5205 // specified and it, along with any default template arguments, 5206 // identifies a single function template specialization, then the 5207 // template-id is an lvalue for the function template specialization. 5208 FunctionTemplateDecl *FunctionTemplate = cast<FunctionTemplateDecl>(*I); 5209 5210 // C++ [over.over]p2: 5211 // If the name is a function template, template argument deduction is 5212 // done (14.8.2.2), and if the argument deduction succeeds, the 5213 // resulting template argument list is used to generate a single 5214 // function template specialization, which is added to the set of 5215 // overloaded functions considered. 5216 FunctionDecl *Specialization = 0; 5217 TemplateDeductionInfo Info(Context, OvlExpr->getNameLoc()); 5218 if (TemplateDeductionResult Result 5219 = DeduceTemplateArguments(FunctionTemplate, &ExplicitTemplateArgs, 5220 Specialization, Info)) { 5221 // FIXME: make a note of the failed deduction for diagnostics. 5222 (void)Result; 5223 continue; 5224 } 5225 5226 // Multiple matches; we can't resolve to a single declaration. 5227 if (Matched) 5228 return 0; 5229 5230 Matched = Specialization; 5231 } 5232 5233 return Matched; 5234} 5235 5236/// \brief Add a single candidate to the overload set. 5237static void AddOverloadedCallCandidate(Sema &S, 5238 DeclAccessPair FoundDecl, 5239 const TemplateArgumentListInfo *ExplicitTemplateArgs, 5240 Expr **Args, unsigned NumArgs, 5241 OverloadCandidateSet &CandidateSet, 5242 bool PartialOverloading) { 5243 NamedDecl *Callee = FoundDecl.getDecl(); 5244 if (isa<UsingShadowDecl>(Callee)) 5245 Callee = cast<UsingShadowDecl>(Callee)->getTargetDecl(); 5246 5247 if (FunctionDecl *Func = dyn_cast<FunctionDecl>(Callee)) { 5248 assert(!ExplicitTemplateArgs && "Explicit template arguments?"); 5249 S.AddOverloadCandidate(Func, FoundDecl, Args, NumArgs, CandidateSet, 5250 false, false, PartialOverloading); 5251 return; 5252 } 5253 5254 if (FunctionTemplateDecl *FuncTemplate 5255 = dyn_cast<FunctionTemplateDecl>(Callee)) { 5256 S.AddTemplateOverloadCandidate(FuncTemplate, FoundDecl, 5257 ExplicitTemplateArgs, 5258 Args, NumArgs, CandidateSet); 5259 return; 5260 } 5261 5262 assert(false && "unhandled case in overloaded call candidate"); 5263 5264 // do nothing? 5265} 5266 5267/// \brief Add the overload candidates named by callee and/or found by argument 5268/// dependent lookup to the given overload set. 5269void Sema::AddOverloadedCallCandidates(UnresolvedLookupExpr *ULE, 5270 Expr **Args, unsigned NumArgs, 5271 OverloadCandidateSet &CandidateSet, 5272 bool PartialOverloading) { 5273 5274#ifndef NDEBUG 5275 // Verify that ArgumentDependentLookup is consistent with the rules 5276 // in C++0x [basic.lookup.argdep]p3: 5277 // 5278 // Let X be the lookup set produced by unqualified lookup (3.4.1) 5279 // and let Y be the lookup set produced by argument dependent 5280 // lookup (defined as follows). If X contains 5281 // 5282 // -- a declaration of a class member, or 5283 // 5284 // -- a block-scope function declaration that is not a 5285 // using-declaration, or 5286 // 5287 // -- a declaration that is neither a function or a function 5288 // template 5289 // 5290 // then Y is empty. 5291 5292 if (ULE->requiresADL()) { 5293 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(), 5294 E = ULE->decls_end(); I != E; ++I) { 5295 assert(!(*I)->getDeclContext()->isRecord()); 5296 assert(isa<UsingShadowDecl>(*I) || 5297 !(*I)->getDeclContext()->isFunctionOrMethod()); 5298 assert((*I)->getUnderlyingDecl()->isFunctionOrFunctionTemplate()); 5299 } 5300 } 5301#endif 5302 5303 // It would be nice to avoid this copy. 5304 TemplateArgumentListInfo TABuffer; 5305 const TemplateArgumentListInfo *ExplicitTemplateArgs = 0; 5306 if (ULE->hasExplicitTemplateArgs()) { 5307 ULE->copyTemplateArgumentsInto(TABuffer); 5308 ExplicitTemplateArgs = &TABuffer; 5309 } 5310 5311 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(), 5312 E = ULE->decls_end(); I != E; ++I) 5313 AddOverloadedCallCandidate(*this, I.getPair(), ExplicitTemplateArgs, 5314 Args, NumArgs, CandidateSet, 5315 PartialOverloading); 5316 5317 if (ULE->requiresADL()) 5318 AddArgumentDependentLookupCandidates(ULE->getName(), /*Operator*/ false, 5319 Args, NumArgs, 5320 ExplicitTemplateArgs, 5321 CandidateSet, 5322 PartialOverloading); 5323} 5324 5325static Sema::OwningExprResult Destroy(Sema &SemaRef, Expr *Fn, 5326 Expr **Args, unsigned NumArgs) { 5327 Fn->Destroy(SemaRef.Context); 5328 for (unsigned Arg = 0; Arg < NumArgs; ++Arg) 5329 Args[Arg]->Destroy(SemaRef.Context); 5330 return SemaRef.ExprError(); 5331} 5332 5333/// Attempts to recover from a call where no functions were found. 5334/// 5335/// Returns true if new candidates were found. 5336static Sema::OwningExprResult 5337BuildRecoveryCallExpr(Sema &SemaRef, Expr *Fn, 5338 UnresolvedLookupExpr *ULE, 5339 SourceLocation LParenLoc, 5340 Expr **Args, unsigned NumArgs, 5341 SourceLocation *CommaLocs, 5342 SourceLocation RParenLoc) { 5343 5344 CXXScopeSpec SS; 5345 if (ULE->getQualifier()) { 5346 SS.setScopeRep(ULE->getQualifier()); 5347 SS.setRange(ULE->getQualifierRange()); 5348 } 5349 5350 TemplateArgumentListInfo TABuffer; 5351 const TemplateArgumentListInfo *ExplicitTemplateArgs = 0; 5352 if (ULE->hasExplicitTemplateArgs()) { 5353 ULE->copyTemplateArgumentsInto(TABuffer); 5354 ExplicitTemplateArgs = &TABuffer; 5355 } 5356 5357 LookupResult R(SemaRef, ULE->getName(), ULE->getNameLoc(), 5358 Sema::LookupOrdinaryName); 5359 if (SemaRef.DiagnoseEmptyLookup(/*Scope=*/0, SS, R)) 5360 return Destroy(SemaRef, Fn, Args, NumArgs); 5361 5362 assert(!R.empty() && "lookup results empty despite recovery"); 5363 5364 // Build an implicit member call if appropriate. Just drop the 5365 // casts and such from the call, we don't really care. 5366 Sema::OwningExprResult NewFn = SemaRef.ExprError(); 5367 if ((*R.begin())->isCXXClassMember()) 5368 NewFn = SemaRef.BuildPossibleImplicitMemberExpr(SS, R, ExplicitTemplateArgs); 5369 else if (ExplicitTemplateArgs) 5370 NewFn = SemaRef.BuildTemplateIdExpr(SS, R, false, *ExplicitTemplateArgs); 5371 else 5372 NewFn = SemaRef.BuildDeclarationNameExpr(SS, R, false); 5373 5374 if (NewFn.isInvalid()) 5375 return Destroy(SemaRef, Fn, Args, NumArgs); 5376 5377 Fn->Destroy(SemaRef.Context); 5378 5379 // This shouldn't cause an infinite loop because we're giving it 5380 // an expression with non-empty lookup results, which should never 5381 // end up here. 5382 return SemaRef.ActOnCallExpr(/*Scope*/ 0, move(NewFn), LParenLoc, 5383 Sema::MultiExprArg(SemaRef, (void**) Args, NumArgs), 5384 CommaLocs, RParenLoc); 5385} 5386 5387/// ResolveOverloadedCallFn - Given the call expression that calls Fn 5388/// (which eventually refers to the declaration Func) and the call 5389/// arguments Args/NumArgs, attempt to resolve the function call down 5390/// to a specific function. If overload resolution succeeds, returns 5391/// the function declaration produced by overload 5392/// resolution. Otherwise, emits diagnostics, deletes all of the 5393/// arguments and Fn, and returns NULL. 5394Sema::OwningExprResult 5395Sema::BuildOverloadedCallExpr(Expr *Fn, UnresolvedLookupExpr *ULE, 5396 SourceLocation LParenLoc, 5397 Expr **Args, unsigned NumArgs, 5398 SourceLocation *CommaLocs, 5399 SourceLocation RParenLoc) { 5400#ifndef NDEBUG 5401 if (ULE->requiresADL()) { 5402 // To do ADL, we must have found an unqualified name. 5403 assert(!ULE->getQualifier() && "qualified name with ADL"); 5404 5405 // We don't perform ADL for implicit declarations of builtins. 5406 // Verify that this was correctly set up. 5407 FunctionDecl *F; 5408 if (ULE->decls_begin() + 1 == ULE->decls_end() && 5409 (F = dyn_cast<FunctionDecl>(*ULE->decls_begin())) && 5410 F->getBuiltinID() && F->isImplicit()) 5411 assert(0 && "performing ADL for builtin"); 5412 5413 // We don't perform ADL in C. 5414 assert(getLangOptions().CPlusPlus && "ADL enabled in C"); 5415 } 5416#endif 5417 5418 OverloadCandidateSet CandidateSet(Fn->getExprLoc()); 5419 5420 // Add the functions denoted by the callee to the set of candidate 5421 // functions, including those from argument-dependent lookup. 5422 AddOverloadedCallCandidates(ULE, Args, NumArgs, CandidateSet); 5423 5424 // If we found nothing, try to recover. 5425 // AddRecoveryCallCandidates diagnoses the error itself, so we just 5426 // bailout out if it fails. 5427 if (CandidateSet.empty()) 5428 return BuildRecoveryCallExpr(*this, Fn, ULE, LParenLoc, Args, NumArgs, 5429 CommaLocs, RParenLoc); 5430 5431 OverloadCandidateSet::iterator Best; 5432 switch (BestViableFunction(CandidateSet, Fn->getLocStart(), Best)) { 5433 case OR_Success: { 5434 FunctionDecl *FDecl = Best->Function; 5435 CheckUnresolvedLookupAccess(ULE, Best->FoundDecl); 5436 Fn = FixOverloadedFunctionReference(Fn, FDecl); 5437 return BuildResolvedCallExpr(Fn, FDecl, LParenLoc, Args, NumArgs, RParenLoc); 5438 } 5439 5440 case OR_No_Viable_Function: 5441 Diag(Fn->getSourceRange().getBegin(), 5442 diag::err_ovl_no_viable_function_in_call) 5443 << ULE->getName() << Fn->getSourceRange(); 5444 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 5445 break; 5446 5447 case OR_Ambiguous: 5448 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_ambiguous_call) 5449 << ULE->getName() << Fn->getSourceRange(); 5450 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, NumArgs); 5451 break; 5452 5453 case OR_Deleted: 5454 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_deleted_call) 5455 << Best->Function->isDeleted() 5456 << ULE->getName() 5457 << Fn->getSourceRange(); 5458 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 5459 break; 5460 } 5461 5462 // Overload resolution failed. Destroy all of the subexpressions and 5463 // return NULL. 5464 Fn->Destroy(Context); 5465 for (unsigned Arg = 0; Arg < NumArgs; ++Arg) 5466 Args[Arg]->Destroy(Context); 5467 return ExprError(); 5468} 5469 5470static bool IsOverloaded(const UnresolvedSetImpl &Functions) { 5471 return Functions.size() > 1 || 5472 (Functions.size() == 1 && isa<FunctionTemplateDecl>(*Functions.begin())); 5473} 5474 5475/// \brief Create a unary operation that may resolve to an overloaded 5476/// operator. 5477/// 5478/// \param OpLoc The location of the operator itself (e.g., '*'). 5479/// 5480/// \param OpcIn The UnaryOperator::Opcode that describes this 5481/// operator. 5482/// 5483/// \param Functions The set of non-member functions that will be 5484/// considered by overload resolution. The caller needs to build this 5485/// set based on the context using, e.g., 5486/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 5487/// set should not contain any member functions; those will be added 5488/// by CreateOverloadedUnaryOp(). 5489/// 5490/// \param input The input argument. 5491Sema::OwningExprResult 5492Sema::CreateOverloadedUnaryOp(SourceLocation OpLoc, unsigned OpcIn, 5493 const UnresolvedSetImpl &Fns, 5494 ExprArg input) { 5495 UnaryOperator::Opcode Opc = static_cast<UnaryOperator::Opcode>(OpcIn); 5496 Expr *Input = (Expr *)input.get(); 5497 5498 OverloadedOperatorKind Op = UnaryOperator::getOverloadedOperator(Opc); 5499 assert(Op != OO_None && "Invalid opcode for overloaded unary operator"); 5500 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 5501 5502 Expr *Args[2] = { Input, 0 }; 5503 unsigned NumArgs = 1; 5504 5505 // For post-increment and post-decrement, add the implicit '0' as 5506 // the second argument, so that we know this is a post-increment or 5507 // post-decrement. 5508 if (Opc == UnaryOperator::PostInc || Opc == UnaryOperator::PostDec) { 5509 llvm::APSInt Zero(Context.getTypeSize(Context.IntTy), false); 5510 Args[1] = new (Context) IntegerLiteral(Zero, Context.IntTy, 5511 SourceLocation()); 5512 NumArgs = 2; 5513 } 5514 5515 if (Input->isTypeDependent()) { 5516 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 5517 UnresolvedLookupExpr *Fn 5518 = UnresolvedLookupExpr::Create(Context, /*Dependent*/ true, NamingClass, 5519 0, SourceRange(), OpName, OpLoc, 5520 /*ADL*/ true, IsOverloaded(Fns)); 5521 Fn->addDecls(Fns.begin(), Fns.end()); 5522 5523 input.release(); 5524 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 5525 &Args[0], NumArgs, 5526 Context.DependentTy, 5527 OpLoc)); 5528 } 5529 5530 // Build an empty overload set. 5531 OverloadCandidateSet CandidateSet(OpLoc); 5532 5533 // Add the candidates from the given function set. 5534 AddFunctionCandidates(Fns, &Args[0], NumArgs, CandidateSet, false); 5535 5536 // Add operator candidates that are member functions. 5537 AddMemberOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 5538 5539 // Add candidates from ADL. 5540 AddArgumentDependentLookupCandidates(OpName, /*Operator*/ true, 5541 Args, NumArgs, 5542 /*ExplicitTemplateArgs*/ 0, 5543 CandidateSet); 5544 5545 // Add builtin operator candidates. 5546 AddBuiltinOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 5547 5548 // Perform overload resolution. 5549 OverloadCandidateSet::iterator Best; 5550 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 5551 case OR_Success: { 5552 // We found a built-in operator or an overloaded operator. 5553 FunctionDecl *FnDecl = Best->Function; 5554 5555 if (FnDecl) { 5556 // We matched an overloaded operator. Build a call to that 5557 // operator. 5558 5559 // Convert the arguments. 5560 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 5561 CheckMemberOperatorAccess(OpLoc, Args[0], 0, Best->FoundDecl); 5562 5563 if (PerformObjectArgumentInitialization(Input, /*Qualifier=*/0, Method)) 5564 return ExprError(); 5565 } else { 5566 // Convert the arguments. 5567 OwningExprResult InputInit 5568 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 5569 FnDecl->getParamDecl(0)), 5570 SourceLocation(), 5571 move(input)); 5572 if (InputInit.isInvalid()) 5573 return ExprError(); 5574 5575 input = move(InputInit); 5576 Input = (Expr *)input.get(); 5577 } 5578 5579 // Determine the result type 5580 QualType ResultTy = FnDecl->getResultType().getNonReferenceType(); 5581 5582 // Build the actual expression node. 5583 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 5584 SourceLocation()); 5585 UsualUnaryConversions(FnExpr); 5586 5587 input.release(); 5588 Args[0] = Input; 5589 ExprOwningPtr<CallExpr> TheCall(this, 5590 new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 5591 Args, NumArgs, ResultTy, OpLoc)); 5592 5593 if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall.get(), 5594 FnDecl)) 5595 return ExprError(); 5596 5597 return MaybeBindToTemporary(TheCall.release()); 5598 } else { 5599 // We matched a built-in operator. Convert the arguments, then 5600 // break out so that we will build the appropriate built-in 5601 // operator node. 5602 if (PerformImplicitConversion(Input, Best->BuiltinTypes.ParamTypes[0], 5603 Best->Conversions[0], AA_Passing)) 5604 return ExprError(); 5605 5606 break; 5607 } 5608 } 5609 5610 case OR_No_Viable_Function: 5611 // No viable function; fall through to handling this as a 5612 // built-in operator, which will produce an error message for us. 5613 break; 5614 5615 case OR_Ambiguous: 5616 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 5617 << UnaryOperator::getOpcodeStr(Opc) 5618 << Input->getSourceRange(); 5619 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, NumArgs, 5620 UnaryOperator::getOpcodeStr(Opc), OpLoc); 5621 return ExprError(); 5622 5623 case OR_Deleted: 5624 Diag(OpLoc, diag::err_ovl_deleted_oper) 5625 << Best->Function->isDeleted() 5626 << UnaryOperator::getOpcodeStr(Opc) 5627 << Input->getSourceRange(); 5628 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 5629 return ExprError(); 5630 } 5631 5632 // Either we found no viable overloaded operator or we matched a 5633 // built-in operator. In either case, fall through to trying to 5634 // build a built-in operation. 5635 input.release(); 5636 return CreateBuiltinUnaryOp(OpLoc, Opc, Owned(Input)); 5637} 5638 5639/// \brief Create a binary operation that may resolve to an overloaded 5640/// operator. 5641/// 5642/// \param OpLoc The location of the operator itself (e.g., '+'). 5643/// 5644/// \param OpcIn The BinaryOperator::Opcode that describes this 5645/// operator. 5646/// 5647/// \param Functions The set of non-member functions that will be 5648/// considered by overload resolution. The caller needs to build this 5649/// set based on the context using, e.g., 5650/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 5651/// set should not contain any member functions; those will be added 5652/// by CreateOverloadedBinOp(). 5653/// 5654/// \param LHS Left-hand argument. 5655/// \param RHS Right-hand argument. 5656Sema::OwningExprResult 5657Sema::CreateOverloadedBinOp(SourceLocation OpLoc, 5658 unsigned OpcIn, 5659 const UnresolvedSetImpl &Fns, 5660 Expr *LHS, Expr *RHS) { 5661 Expr *Args[2] = { LHS, RHS }; 5662 LHS=RHS=0; //Please use only Args instead of LHS/RHS couple 5663 5664 BinaryOperator::Opcode Opc = static_cast<BinaryOperator::Opcode>(OpcIn); 5665 OverloadedOperatorKind Op = BinaryOperator::getOverloadedOperator(Opc); 5666 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 5667 5668 // If either side is type-dependent, create an appropriate dependent 5669 // expression. 5670 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 5671 if (Fns.empty()) { 5672 // If there are no functions to store, just build a dependent 5673 // BinaryOperator or CompoundAssignment. 5674 if (Opc <= BinaryOperator::Assign || Opc > BinaryOperator::OrAssign) 5675 return Owned(new (Context) BinaryOperator(Args[0], Args[1], Opc, 5676 Context.DependentTy, OpLoc)); 5677 5678 return Owned(new (Context) CompoundAssignOperator(Args[0], Args[1], Opc, 5679 Context.DependentTy, 5680 Context.DependentTy, 5681 Context.DependentTy, 5682 OpLoc)); 5683 } 5684 5685 // FIXME: save results of ADL from here? 5686 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 5687 UnresolvedLookupExpr *Fn 5688 = UnresolvedLookupExpr::Create(Context, /*Dependent*/ true, NamingClass, 5689 0, SourceRange(), OpName, OpLoc, 5690 /*ADL*/ true, IsOverloaded(Fns)); 5691 5692 Fn->addDecls(Fns.begin(), Fns.end()); 5693 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 5694 Args, 2, 5695 Context.DependentTy, 5696 OpLoc)); 5697 } 5698 5699 // If this is the .* operator, which is not overloadable, just 5700 // create a built-in binary operator. 5701 if (Opc == BinaryOperator::PtrMemD) 5702 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 5703 5704 // If this is the assignment operator, we only perform overload resolution 5705 // if the left-hand side is a class or enumeration type. This is actually 5706 // a hack. The standard requires that we do overload resolution between the 5707 // various built-in candidates, but as DR507 points out, this can lead to 5708 // problems. So we do it this way, which pretty much follows what GCC does. 5709 // Note that we go the traditional code path for compound assignment forms. 5710 if (Opc==BinaryOperator::Assign && !Args[0]->getType()->isOverloadableType()) 5711 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 5712 5713 // Build an empty overload set. 5714 OverloadCandidateSet CandidateSet(OpLoc); 5715 5716 // Add the candidates from the given function set. 5717 AddFunctionCandidates(Fns, Args, 2, CandidateSet, false); 5718 5719 // Add operator candidates that are member functions. 5720 AddMemberOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 5721 5722 // Add candidates from ADL. 5723 AddArgumentDependentLookupCandidates(OpName, /*Operator*/ true, 5724 Args, 2, 5725 /*ExplicitTemplateArgs*/ 0, 5726 CandidateSet); 5727 5728 // Add builtin operator candidates. 5729 AddBuiltinOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 5730 5731 // Perform overload resolution. 5732 OverloadCandidateSet::iterator Best; 5733 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 5734 case OR_Success: { 5735 // We found a built-in operator or an overloaded operator. 5736 FunctionDecl *FnDecl = Best->Function; 5737 5738 if (FnDecl) { 5739 // We matched an overloaded operator. Build a call to that 5740 // operator. 5741 5742 // Convert the arguments. 5743 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 5744 // Best->Access is only meaningful for class members. 5745 CheckMemberOperatorAccess(OpLoc, Args[0], Args[1], Best->FoundDecl); 5746 5747 OwningExprResult Arg1 5748 = PerformCopyInitialization( 5749 InitializedEntity::InitializeParameter( 5750 FnDecl->getParamDecl(0)), 5751 SourceLocation(), 5752 Owned(Args[1])); 5753 if (Arg1.isInvalid()) 5754 return ExprError(); 5755 5756 if (PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/0, 5757 Method)) 5758 return ExprError(); 5759 5760 Args[1] = RHS = Arg1.takeAs<Expr>(); 5761 } else { 5762 // Convert the arguments. 5763 OwningExprResult Arg0 5764 = PerformCopyInitialization( 5765 InitializedEntity::InitializeParameter( 5766 FnDecl->getParamDecl(0)), 5767 SourceLocation(), 5768 Owned(Args[0])); 5769 if (Arg0.isInvalid()) 5770 return ExprError(); 5771 5772 OwningExprResult Arg1 5773 = PerformCopyInitialization( 5774 InitializedEntity::InitializeParameter( 5775 FnDecl->getParamDecl(1)), 5776 SourceLocation(), 5777 Owned(Args[1])); 5778 if (Arg1.isInvalid()) 5779 return ExprError(); 5780 Args[0] = LHS = Arg0.takeAs<Expr>(); 5781 Args[1] = RHS = Arg1.takeAs<Expr>(); 5782 } 5783 5784 // Determine the result type 5785 QualType ResultTy 5786 = FnDecl->getType()->getAs<FunctionType>()->getResultType(); 5787 ResultTy = ResultTy.getNonReferenceType(); 5788 5789 // Build the actual expression node. 5790 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 5791 OpLoc); 5792 UsualUnaryConversions(FnExpr); 5793 5794 ExprOwningPtr<CXXOperatorCallExpr> 5795 TheCall(this, new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 5796 Args, 2, ResultTy, 5797 OpLoc)); 5798 5799 if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall.get(), 5800 FnDecl)) 5801 return ExprError(); 5802 5803 return MaybeBindToTemporary(TheCall.release()); 5804 } else { 5805 // We matched a built-in operator. Convert the arguments, then 5806 // break out so that we will build the appropriate built-in 5807 // operator node. 5808 if (PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 5809 Best->Conversions[0], AA_Passing) || 5810 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 5811 Best->Conversions[1], AA_Passing)) 5812 return ExprError(); 5813 5814 break; 5815 } 5816 } 5817 5818 case OR_No_Viable_Function: { 5819 // C++ [over.match.oper]p9: 5820 // If the operator is the operator , [...] and there are no 5821 // viable functions, then the operator is assumed to be the 5822 // built-in operator and interpreted according to clause 5. 5823 if (Opc == BinaryOperator::Comma) 5824 break; 5825 5826 // For class as left operand for assignment or compound assigment operator 5827 // do not fall through to handling in built-in, but report that no overloaded 5828 // assignment operator found 5829 OwningExprResult Result = ExprError(); 5830 if (Args[0]->getType()->isRecordType() && 5831 Opc >= BinaryOperator::Assign && Opc <= BinaryOperator::OrAssign) { 5832 Diag(OpLoc, diag::err_ovl_no_viable_oper) 5833 << BinaryOperator::getOpcodeStr(Opc) 5834 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 5835 } else { 5836 // No viable function; try to create a built-in operation, which will 5837 // produce an error. Then, show the non-viable candidates. 5838 Result = CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 5839 } 5840 assert(Result.isInvalid() && 5841 "C++ binary operator overloading is missing candidates!"); 5842 if (Result.isInvalid()) 5843 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2, 5844 BinaryOperator::getOpcodeStr(Opc), OpLoc); 5845 return move(Result); 5846 } 5847 5848 case OR_Ambiguous: 5849 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 5850 << BinaryOperator::getOpcodeStr(Opc) 5851 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 5852 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, 2, 5853 BinaryOperator::getOpcodeStr(Opc), OpLoc); 5854 return ExprError(); 5855 5856 case OR_Deleted: 5857 Diag(OpLoc, diag::err_ovl_deleted_oper) 5858 << Best->Function->isDeleted() 5859 << BinaryOperator::getOpcodeStr(Opc) 5860 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 5861 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2); 5862 return ExprError(); 5863 } 5864 5865 // We matched a built-in operator; build it. 5866 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 5867} 5868 5869Action::OwningExprResult 5870Sema::CreateOverloadedArraySubscriptExpr(SourceLocation LLoc, 5871 SourceLocation RLoc, 5872 ExprArg Base, ExprArg Idx) { 5873 Expr *Args[2] = { static_cast<Expr*>(Base.get()), 5874 static_cast<Expr*>(Idx.get()) }; 5875 DeclarationName OpName = 5876 Context.DeclarationNames.getCXXOperatorName(OO_Subscript); 5877 5878 // If either side is type-dependent, create an appropriate dependent 5879 // expression. 5880 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 5881 5882 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 5883 UnresolvedLookupExpr *Fn 5884 = UnresolvedLookupExpr::Create(Context, /*Dependent*/ true, NamingClass, 5885 0, SourceRange(), OpName, LLoc, 5886 /*ADL*/ true, /*Overloaded*/ false); 5887 // Can't add any actual overloads yet 5888 5889 Base.release(); 5890 Idx.release(); 5891 return Owned(new (Context) CXXOperatorCallExpr(Context, OO_Subscript, Fn, 5892 Args, 2, 5893 Context.DependentTy, 5894 RLoc)); 5895 } 5896 5897 // Build an empty overload set. 5898 OverloadCandidateSet CandidateSet(LLoc); 5899 5900 // Subscript can only be overloaded as a member function. 5901 5902 // Add operator candidates that are member functions. 5903 AddMemberOperatorCandidates(OO_Subscript, LLoc, Args, 2, CandidateSet); 5904 5905 // Add builtin operator candidates. 5906 AddBuiltinOperatorCandidates(OO_Subscript, LLoc, Args, 2, CandidateSet); 5907 5908 // Perform overload resolution. 5909 OverloadCandidateSet::iterator Best; 5910 switch (BestViableFunction(CandidateSet, LLoc, Best)) { 5911 case OR_Success: { 5912 // We found a built-in operator or an overloaded operator. 5913 FunctionDecl *FnDecl = Best->Function; 5914 5915 if (FnDecl) { 5916 // We matched an overloaded operator. Build a call to that 5917 // operator. 5918 5919 CheckMemberOperatorAccess(LLoc, Args[0], Args[1], Best->FoundDecl); 5920 5921 // Convert the arguments. 5922 CXXMethodDecl *Method = cast<CXXMethodDecl>(FnDecl); 5923 if (PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/0, 5924 Method)) 5925 return ExprError(); 5926 5927 // Convert the arguments. 5928 OwningExprResult InputInit 5929 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 5930 FnDecl->getParamDecl(0)), 5931 SourceLocation(), 5932 Owned(Args[1])); 5933 if (InputInit.isInvalid()) 5934 return ExprError(); 5935 5936 Args[1] = InputInit.takeAs<Expr>(); 5937 5938 // Determine the result type 5939 QualType ResultTy 5940 = FnDecl->getType()->getAs<FunctionType>()->getResultType(); 5941 ResultTy = ResultTy.getNonReferenceType(); 5942 5943 // Build the actual expression node. 5944 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 5945 LLoc); 5946 UsualUnaryConversions(FnExpr); 5947 5948 Base.release(); 5949 Idx.release(); 5950 ExprOwningPtr<CXXOperatorCallExpr> 5951 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Subscript, 5952 FnExpr, Args, 2, 5953 ResultTy, RLoc)); 5954 5955 if (CheckCallReturnType(FnDecl->getResultType(), LLoc, TheCall.get(), 5956 FnDecl)) 5957 return ExprError(); 5958 5959 return MaybeBindToTemporary(TheCall.release()); 5960 } else { 5961 // We matched a built-in operator. Convert the arguments, then 5962 // break out so that we will build the appropriate built-in 5963 // operator node. 5964 if (PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 5965 Best->Conversions[0], AA_Passing) || 5966 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 5967 Best->Conversions[1], AA_Passing)) 5968 return ExprError(); 5969 5970 break; 5971 } 5972 } 5973 5974 case OR_No_Viable_Function: { 5975 if (CandidateSet.empty()) 5976 Diag(LLoc, diag::err_ovl_no_oper) 5977 << Args[0]->getType() << /*subscript*/ 0 5978 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 5979 else 5980 Diag(LLoc, diag::err_ovl_no_viable_subscript) 5981 << Args[0]->getType() 5982 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 5983 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2, 5984 "[]", LLoc); 5985 return ExprError(); 5986 } 5987 5988 case OR_Ambiguous: 5989 Diag(LLoc, diag::err_ovl_ambiguous_oper) 5990 << "[]" << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 5991 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, 2, 5992 "[]", LLoc); 5993 return ExprError(); 5994 5995 case OR_Deleted: 5996 Diag(LLoc, diag::err_ovl_deleted_oper) 5997 << Best->Function->isDeleted() << "[]" 5998 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 5999 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2, 6000 "[]", LLoc); 6001 return ExprError(); 6002 } 6003 6004 // We matched a built-in operator; build it. 6005 Base.release(); 6006 Idx.release(); 6007 return CreateBuiltinArraySubscriptExpr(Owned(Args[0]), LLoc, 6008 Owned(Args[1]), RLoc); 6009} 6010 6011/// BuildCallToMemberFunction - Build a call to a member 6012/// function. MemExpr is the expression that refers to the member 6013/// function (and includes the object parameter), Args/NumArgs are the 6014/// arguments to the function call (not including the object 6015/// parameter). The caller needs to validate that the member 6016/// expression refers to a member function or an overloaded member 6017/// function. 6018Sema::OwningExprResult 6019Sema::BuildCallToMemberFunction(Scope *S, Expr *MemExprE, 6020 SourceLocation LParenLoc, Expr **Args, 6021 unsigned NumArgs, SourceLocation *CommaLocs, 6022 SourceLocation RParenLoc) { 6023 // Dig out the member expression. This holds both the object 6024 // argument and the member function we're referring to. 6025 Expr *NakedMemExpr = MemExprE->IgnoreParens(); 6026 6027 MemberExpr *MemExpr; 6028 CXXMethodDecl *Method = 0; 6029 NestedNameSpecifier *Qualifier = 0; 6030 if (isa<MemberExpr>(NakedMemExpr)) { 6031 MemExpr = cast<MemberExpr>(NakedMemExpr); 6032 Method = cast<CXXMethodDecl>(MemExpr->getMemberDecl()); 6033 Qualifier = MemExpr->getQualifier(); 6034 } else { 6035 UnresolvedMemberExpr *UnresExpr = cast<UnresolvedMemberExpr>(NakedMemExpr); 6036 Qualifier = UnresExpr->getQualifier(); 6037 6038 QualType ObjectType = UnresExpr->getBaseType(); 6039 6040 // Add overload candidates 6041 OverloadCandidateSet CandidateSet(UnresExpr->getMemberLoc()); 6042 6043 // FIXME: avoid copy. 6044 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 6045 if (UnresExpr->hasExplicitTemplateArgs()) { 6046 UnresExpr->copyTemplateArgumentsInto(TemplateArgsBuffer); 6047 TemplateArgs = &TemplateArgsBuffer; 6048 } 6049 6050 for (UnresolvedMemberExpr::decls_iterator I = UnresExpr->decls_begin(), 6051 E = UnresExpr->decls_end(); I != E; ++I) { 6052 6053 NamedDecl *Func = *I; 6054 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(Func->getDeclContext()); 6055 if (isa<UsingShadowDecl>(Func)) 6056 Func = cast<UsingShadowDecl>(Func)->getTargetDecl(); 6057 6058 if ((Method = dyn_cast<CXXMethodDecl>(Func))) { 6059 // If explicit template arguments were provided, we can't call a 6060 // non-template member function. 6061 if (TemplateArgs) 6062 continue; 6063 6064 AddMethodCandidate(Method, I.getPair(), ActingDC, ObjectType, 6065 Args, NumArgs, 6066 CandidateSet, /*SuppressUserConversions=*/false); 6067 } else { 6068 AddMethodTemplateCandidate(cast<FunctionTemplateDecl>(Func), 6069 I.getPair(), ActingDC, TemplateArgs, 6070 ObjectType, Args, NumArgs, 6071 CandidateSet, 6072 /*SuppressUsedConversions=*/false); 6073 } 6074 } 6075 6076 DeclarationName DeclName = UnresExpr->getMemberName(); 6077 6078 OverloadCandidateSet::iterator Best; 6079 switch (BestViableFunction(CandidateSet, UnresExpr->getLocStart(), Best)) { 6080 case OR_Success: 6081 Method = cast<CXXMethodDecl>(Best->Function); 6082 CheckUnresolvedMemberAccess(UnresExpr, Best->FoundDecl); 6083 break; 6084 6085 case OR_No_Viable_Function: 6086 Diag(UnresExpr->getMemberLoc(), 6087 diag::err_ovl_no_viable_member_function_in_call) 6088 << DeclName << MemExprE->getSourceRange(); 6089 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6090 // FIXME: Leaking incoming expressions! 6091 return ExprError(); 6092 6093 case OR_Ambiguous: 6094 Diag(UnresExpr->getMemberLoc(), diag::err_ovl_ambiguous_member_call) 6095 << DeclName << MemExprE->getSourceRange(); 6096 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6097 // FIXME: Leaking incoming expressions! 6098 return ExprError(); 6099 6100 case OR_Deleted: 6101 Diag(UnresExpr->getMemberLoc(), diag::err_ovl_deleted_member_call) 6102 << Best->Function->isDeleted() 6103 << DeclName << MemExprE->getSourceRange(); 6104 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6105 // FIXME: Leaking incoming expressions! 6106 return ExprError(); 6107 } 6108 6109 MemExprE = FixOverloadedFunctionReference(MemExprE, Method); 6110 6111 // If overload resolution picked a static member, build a 6112 // non-member call based on that function. 6113 if (Method->isStatic()) { 6114 return BuildResolvedCallExpr(MemExprE, Method, LParenLoc, 6115 Args, NumArgs, RParenLoc); 6116 } 6117 6118 MemExpr = cast<MemberExpr>(MemExprE->IgnoreParens()); 6119 } 6120 6121 assert(Method && "Member call to something that isn't a method?"); 6122 ExprOwningPtr<CXXMemberCallExpr> 6123 TheCall(this, new (Context) CXXMemberCallExpr(Context, MemExprE, Args, 6124 NumArgs, 6125 Method->getResultType().getNonReferenceType(), 6126 RParenLoc)); 6127 6128 // Check for a valid return type. 6129 if (CheckCallReturnType(Method->getResultType(), MemExpr->getMemberLoc(), 6130 TheCall.get(), Method)) 6131 return ExprError(); 6132 6133 // Convert the object argument (for a non-static member function call). 6134 Expr *ObjectArg = MemExpr->getBase(); 6135 if (!Method->isStatic() && 6136 PerformObjectArgumentInitialization(ObjectArg, Qualifier, Method)) 6137 return ExprError(); 6138 MemExpr->setBase(ObjectArg); 6139 6140 // Convert the rest of the arguments 6141 const FunctionProtoType *Proto = cast<FunctionProtoType>(Method->getType()); 6142 if (ConvertArgumentsForCall(&*TheCall, MemExpr, Method, Proto, Args, NumArgs, 6143 RParenLoc)) 6144 return ExprError(); 6145 6146 if (CheckFunctionCall(Method, TheCall.get())) 6147 return ExprError(); 6148 6149 return MaybeBindToTemporary(TheCall.release()); 6150} 6151 6152/// BuildCallToObjectOfClassType - Build a call to an object of class 6153/// type (C++ [over.call.object]), which can end up invoking an 6154/// overloaded function call operator (@c operator()) or performing a 6155/// user-defined conversion on the object argument. 6156Sema::ExprResult 6157Sema::BuildCallToObjectOfClassType(Scope *S, Expr *Object, 6158 SourceLocation LParenLoc, 6159 Expr **Args, unsigned NumArgs, 6160 SourceLocation *CommaLocs, 6161 SourceLocation RParenLoc) { 6162 assert(Object->getType()->isRecordType() && "Requires object type argument"); 6163 const RecordType *Record = Object->getType()->getAs<RecordType>(); 6164 6165 // C++ [over.call.object]p1: 6166 // If the primary-expression E in the function call syntax 6167 // evaluates to a class object of type "cv T", then the set of 6168 // candidate functions includes at least the function call 6169 // operators of T. The function call operators of T are obtained by 6170 // ordinary lookup of the name operator() in the context of 6171 // (E).operator(). 6172 OverloadCandidateSet CandidateSet(LParenLoc); 6173 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Call); 6174 6175 if (RequireCompleteType(LParenLoc, Object->getType(), 6176 PartialDiagnostic(diag::err_incomplete_object_call) 6177 << Object->getSourceRange())) 6178 return true; 6179 6180 LookupResult R(*this, OpName, LParenLoc, LookupOrdinaryName); 6181 LookupQualifiedName(R, Record->getDecl()); 6182 R.suppressDiagnostics(); 6183 6184 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 6185 Oper != OperEnd; ++Oper) { 6186 AddMethodCandidate(Oper.getPair(), Object->getType(), 6187 Args, NumArgs, CandidateSet, 6188 /*SuppressUserConversions=*/ false); 6189 } 6190 6191 // C++ [over.call.object]p2: 6192 // In addition, for each conversion function declared in T of the 6193 // form 6194 // 6195 // operator conversion-type-id () cv-qualifier; 6196 // 6197 // where cv-qualifier is the same cv-qualification as, or a 6198 // greater cv-qualification than, cv, and where conversion-type-id 6199 // denotes the type "pointer to function of (P1,...,Pn) returning 6200 // R", or the type "reference to pointer to function of 6201 // (P1,...,Pn) returning R", or the type "reference to function 6202 // of (P1,...,Pn) returning R", a surrogate call function [...] 6203 // is also considered as a candidate function. Similarly, 6204 // surrogate call functions are added to the set of candidate 6205 // functions for each conversion function declared in an 6206 // accessible base class provided the function is not hidden 6207 // within T by another intervening declaration. 6208 const UnresolvedSetImpl *Conversions 6209 = cast<CXXRecordDecl>(Record->getDecl())->getVisibleConversionFunctions(); 6210 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 6211 E = Conversions->end(); I != E; ++I) { 6212 NamedDecl *D = *I; 6213 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext()); 6214 if (isa<UsingShadowDecl>(D)) 6215 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 6216 6217 // Skip over templated conversion functions; they aren't 6218 // surrogates. 6219 if (isa<FunctionTemplateDecl>(D)) 6220 continue; 6221 6222 CXXConversionDecl *Conv = cast<CXXConversionDecl>(D); 6223 6224 // Strip the reference type (if any) and then the pointer type (if 6225 // any) to get down to what might be a function type. 6226 QualType ConvType = Conv->getConversionType().getNonReferenceType(); 6227 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 6228 ConvType = ConvPtrType->getPointeeType(); 6229 6230 if (const FunctionProtoType *Proto = ConvType->getAs<FunctionProtoType>()) 6231 AddSurrogateCandidate(Conv, I.getPair(), ActingContext, Proto, 6232 Object->getType(), Args, NumArgs, 6233 CandidateSet); 6234 } 6235 6236 // Perform overload resolution. 6237 OverloadCandidateSet::iterator Best; 6238 switch (BestViableFunction(CandidateSet, Object->getLocStart(), Best)) { 6239 case OR_Success: 6240 // Overload resolution succeeded; we'll build the appropriate call 6241 // below. 6242 break; 6243 6244 case OR_No_Viable_Function: 6245 if (CandidateSet.empty()) 6246 Diag(Object->getSourceRange().getBegin(), diag::err_ovl_no_oper) 6247 << Object->getType() << /*call*/ 1 6248 << Object->getSourceRange(); 6249 else 6250 Diag(Object->getSourceRange().getBegin(), 6251 diag::err_ovl_no_viable_object_call) 6252 << Object->getType() << Object->getSourceRange(); 6253 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6254 break; 6255 6256 case OR_Ambiguous: 6257 Diag(Object->getSourceRange().getBegin(), 6258 diag::err_ovl_ambiguous_object_call) 6259 << Object->getType() << Object->getSourceRange(); 6260 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, NumArgs); 6261 break; 6262 6263 case OR_Deleted: 6264 Diag(Object->getSourceRange().getBegin(), 6265 diag::err_ovl_deleted_object_call) 6266 << Best->Function->isDeleted() 6267 << Object->getType() << Object->getSourceRange(); 6268 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6269 break; 6270 } 6271 6272 if (Best == CandidateSet.end()) { 6273 // We had an error; delete all of the subexpressions and return 6274 // the error. 6275 Object->Destroy(Context); 6276 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 6277 Args[ArgIdx]->Destroy(Context); 6278 return true; 6279 } 6280 6281 if (Best->Function == 0) { 6282 // Since there is no function declaration, this is one of the 6283 // surrogate candidates. Dig out the conversion function. 6284 CXXConversionDecl *Conv 6285 = cast<CXXConversionDecl>( 6286 Best->Conversions[0].UserDefined.ConversionFunction); 6287 6288 CheckMemberOperatorAccess(LParenLoc, Object, 0, Best->FoundDecl); 6289 6290 // We selected one of the surrogate functions that converts the 6291 // object parameter to a function pointer. Perform the conversion 6292 // on the object argument, then let ActOnCallExpr finish the job. 6293 6294 // Create an implicit member expr to refer to the conversion operator. 6295 // and then call it. 6296 CXXMemberCallExpr *CE = BuildCXXMemberCallExpr(Object, Conv); 6297 6298 return ActOnCallExpr(S, ExprArg(*this, CE), LParenLoc, 6299 MultiExprArg(*this, (ExprTy**)Args, NumArgs), 6300 CommaLocs, RParenLoc).release(); 6301 } 6302 6303 CheckMemberOperatorAccess(LParenLoc, Object, 0, Best->FoundDecl); 6304 6305 // We found an overloaded operator(). Build a CXXOperatorCallExpr 6306 // that calls this method, using Object for the implicit object 6307 // parameter and passing along the remaining arguments. 6308 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 6309 const FunctionProtoType *Proto = Method->getType()->getAs<FunctionProtoType>(); 6310 6311 unsigned NumArgsInProto = Proto->getNumArgs(); 6312 unsigned NumArgsToCheck = NumArgs; 6313 6314 // Build the full argument list for the method call (the 6315 // implicit object parameter is placed at the beginning of the 6316 // list). 6317 Expr **MethodArgs; 6318 if (NumArgs < NumArgsInProto) { 6319 NumArgsToCheck = NumArgsInProto; 6320 MethodArgs = new Expr*[NumArgsInProto + 1]; 6321 } else { 6322 MethodArgs = new Expr*[NumArgs + 1]; 6323 } 6324 MethodArgs[0] = Object; 6325 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 6326 MethodArgs[ArgIdx + 1] = Args[ArgIdx]; 6327 6328 Expr *NewFn = new (Context) DeclRefExpr(Method, Method->getType(), 6329 SourceLocation()); 6330 UsualUnaryConversions(NewFn); 6331 6332 // Once we've built TheCall, all of the expressions are properly 6333 // owned. 6334 QualType ResultTy = Method->getResultType().getNonReferenceType(); 6335 ExprOwningPtr<CXXOperatorCallExpr> 6336 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Call, NewFn, 6337 MethodArgs, NumArgs + 1, 6338 ResultTy, RParenLoc)); 6339 delete [] MethodArgs; 6340 6341 if (CheckCallReturnType(Method->getResultType(), LParenLoc, TheCall.get(), 6342 Method)) 6343 return true; 6344 6345 // We may have default arguments. If so, we need to allocate more 6346 // slots in the call for them. 6347 if (NumArgs < NumArgsInProto) 6348 TheCall->setNumArgs(Context, NumArgsInProto + 1); 6349 else if (NumArgs > NumArgsInProto) 6350 NumArgsToCheck = NumArgsInProto; 6351 6352 bool IsError = false; 6353 6354 // Initialize the implicit object parameter. 6355 IsError |= PerformObjectArgumentInitialization(Object, /*Qualifier=*/0, 6356 Method); 6357 TheCall->setArg(0, Object); 6358 6359 6360 // Check the argument types. 6361 for (unsigned i = 0; i != NumArgsToCheck; i++) { 6362 Expr *Arg; 6363 if (i < NumArgs) { 6364 Arg = Args[i]; 6365 6366 // Pass the argument. 6367 6368 OwningExprResult InputInit 6369 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 6370 Method->getParamDecl(i)), 6371 SourceLocation(), Owned(Arg)); 6372 6373 IsError |= InputInit.isInvalid(); 6374 Arg = InputInit.takeAs<Expr>(); 6375 } else { 6376 OwningExprResult DefArg 6377 = BuildCXXDefaultArgExpr(LParenLoc, Method, Method->getParamDecl(i)); 6378 if (DefArg.isInvalid()) { 6379 IsError = true; 6380 break; 6381 } 6382 6383 Arg = DefArg.takeAs<Expr>(); 6384 } 6385 6386 TheCall->setArg(i + 1, Arg); 6387 } 6388 6389 // If this is a variadic call, handle args passed through "...". 6390 if (Proto->isVariadic()) { 6391 // Promote the arguments (C99 6.5.2.2p7). 6392 for (unsigned i = NumArgsInProto; i != NumArgs; i++) { 6393 Expr *Arg = Args[i]; 6394 IsError |= DefaultVariadicArgumentPromotion(Arg, VariadicMethod); 6395 TheCall->setArg(i + 1, Arg); 6396 } 6397 } 6398 6399 if (IsError) return true; 6400 6401 if (CheckFunctionCall(Method, TheCall.get())) 6402 return true; 6403 6404 return MaybeBindToTemporary(TheCall.release()).release(); 6405} 6406 6407/// BuildOverloadedArrowExpr - Build a call to an overloaded @c operator-> 6408/// (if one exists), where @c Base is an expression of class type and 6409/// @c Member is the name of the member we're trying to find. 6410Sema::OwningExprResult 6411Sema::BuildOverloadedArrowExpr(Scope *S, ExprArg BaseIn, SourceLocation OpLoc) { 6412 Expr *Base = static_cast<Expr *>(BaseIn.get()); 6413 assert(Base->getType()->isRecordType() && "left-hand side must have class type"); 6414 6415 SourceLocation Loc = Base->getExprLoc(); 6416 6417 // C++ [over.ref]p1: 6418 // 6419 // [...] An expression x->m is interpreted as (x.operator->())->m 6420 // for a class object x of type T if T::operator->() exists and if 6421 // the operator is selected as the best match function by the 6422 // overload resolution mechanism (13.3). 6423 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Arrow); 6424 OverloadCandidateSet CandidateSet(Loc); 6425 const RecordType *BaseRecord = Base->getType()->getAs<RecordType>(); 6426 6427 if (RequireCompleteType(Loc, Base->getType(), 6428 PDiag(diag::err_typecheck_incomplete_tag) 6429 << Base->getSourceRange())) 6430 return ExprError(); 6431 6432 LookupResult R(*this, OpName, OpLoc, LookupOrdinaryName); 6433 LookupQualifiedName(R, BaseRecord->getDecl()); 6434 R.suppressDiagnostics(); 6435 6436 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 6437 Oper != OperEnd; ++Oper) { 6438 AddMethodCandidate(Oper.getPair(), Base->getType(), 0, 0, CandidateSet, 6439 /*SuppressUserConversions=*/false); 6440 } 6441 6442 // Perform overload resolution. 6443 OverloadCandidateSet::iterator Best; 6444 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 6445 case OR_Success: 6446 // Overload resolution succeeded; we'll build the call below. 6447 break; 6448 6449 case OR_No_Viable_Function: 6450 if (CandidateSet.empty()) 6451 Diag(OpLoc, diag::err_typecheck_member_reference_arrow) 6452 << Base->getType() << Base->getSourceRange(); 6453 else 6454 Diag(OpLoc, diag::err_ovl_no_viable_oper) 6455 << "operator->" << Base->getSourceRange(); 6456 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, &Base, 1); 6457 return ExprError(); 6458 6459 case OR_Ambiguous: 6460 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 6461 << "->" << Base->getSourceRange(); 6462 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, &Base, 1); 6463 return ExprError(); 6464 6465 case OR_Deleted: 6466 Diag(OpLoc, diag::err_ovl_deleted_oper) 6467 << Best->Function->isDeleted() 6468 << "->" << Base->getSourceRange(); 6469 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, &Base, 1); 6470 return ExprError(); 6471 } 6472 6473 CheckMemberOperatorAccess(OpLoc, Base, 0, Best->FoundDecl); 6474 6475 // Convert the object parameter. 6476 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 6477 if (PerformObjectArgumentInitialization(Base, /*Qualifier=*/0, Method)) 6478 return ExprError(); 6479 6480 // No concerns about early exits now. 6481 BaseIn.release(); 6482 6483 // Build the operator call. 6484 Expr *FnExpr = new (Context) DeclRefExpr(Method, Method->getType(), 6485 SourceLocation()); 6486 UsualUnaryConversions(FnExpr); 6487 6488 QualType ResultTy = Method->getResultType().getNonReferenceType(); 6489 ExprOwningPtr<CXXOperatorCallExpr> 6490 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Arrow, FnExpr, 6491 &Base, 1, ResultTy, OpLoc)); 6492 6493 if (CheckCallReturnType(Method->getResultType(), OpLoc, TheCall.get(), 6494 Method)) 6495 return ExprError(); 6496 return move(TheCall); 6497} 6498 6499/// FixOverloadedFunctionReference - E is an expression that refers to 6500/// a C++ overloaded function (possibly with some parentheses and 6501/// perhaps a '&' around it). We have resolved the overloaded function 6502/// to the function declaration Fn, so patch up the expression E to 6503/// refer (possibly indirectly) to Fn. Returns the new expr. 6504Expr *Sema::FixOverloadedFunctionReference(Expr *E, FunctionDecl *Fn) { 6505 if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) { 6506 Expr *SubExpr = FixOverloadedFunctionReference(PE->getSubExpr(), Fn); 6507 if (SubExpr == PE->getSubExpr()) 6508 return PE->Retain(); 6509 6510 return new (Context) ParenExpr(PE->getLParen(), PE->getRParen(), SubExpr); 6511 } 6512 6513 if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) { 6514 Expr *SubExpr = FixOverloadedFunctionReference(ICE->getSubExpr(), Fn); 6515 assert(Context.hasSameType(ICE->getSubExpr()->getType(), 6516 SubExpr->getType()) && 6517 "Implicit cast type cannot be determined from overload"); 6518 if (SubExpr == ICE->getSubExpr()) 6519 return ICE->Retain(); 6520 6521 return new (Context) ImplicitCastExpr(ICE->getType(), 6522 ICE->getCastKind(), 6523 SubExpr, 6524 ICE->isLvalueCast()); 6525 } 6526 6527 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(E)) { 6528 assert(UnOp->getOpcode() == UnaryOperator::AddrOf && 6529 "Can only take the address of an overloaded function"); 6530 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 6531 if (Method->isStatic()) { 6532 // Do nothing: static member functions aren't any different 6533 // from non-member functions. 6534 } else { 6535 // Fix the sub expression, which really has to be an 6536 // UnresolvedLookupExpr holding an overloaded member function 6537 // or template. 6538 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(), Fn); 6539 if (SubExpr == UnOp->getSubExpr()) 6540 return UnOp->Retain(); 6541 6542 assert(isa<DeclRefExpr>(SubExpr) 6543 && "fixed to something other than a decl ref"); 6544 assert(cast<DeclRefExpr>(SubExpr)->getQualifier() 6545 && "fixed to a member ref with no nested name qualifier"); 6546 6547 // We have taken the address of a pointer to member 6548 // function. Perform the computation here so that we get the 6549 // appropriate pointer to member type. 6550 QualType ClassType 6551 = Context.getTypeDeclType(cast<RecordDecl>(Method->getDeclContext())); 6552 QualType MemPtrType 6553 = Context.getMemberPointerType(Fn->getType(), ClassType.getTypePtr()); 6554 6555 return new (Context) UnaryOperator(SubExpr, UnaryOperator::AddrOf, 6556 MemPtrType, UnOp->getOperatorLoc()); 6557 } 6558 } 6559 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(), Fn); 6560 if (SubExpr == UnOp->getSubExpr()) 6561 return UnOp->Retain(); 6562 6563 return new (Context) UnaryOperator(SubExpr, UnaryOperator::AddrOf, 6564 Context.getPointerType(SubExpr->getType()), 6565 UnOp->getOperatorLoc()); 6566 } 6567 6568 if (UnresolvedLookupExpr *ULE = dyn_cast<UnresolvedLookupExpr>(E)) { 6569 // FIXME: avoid copy. 6570 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 6571 if (ULE->hasExplicitTemplateArgs()) { 6572 ULE->copyTemplateArgumentsInto(TemplateArgsBuffer); 6573 TemplateArgs = &TemplateArgsBuffer; 6574 } 6575 6576 return DeclRefExpr::Create(Context, 6577 ULE->getQualifier(), 6578 ULE->getQualifierRange(), 6579 Fn, 6580 ULE->getNameLoc(), 6581 Fn->getType(), 6582 TemplateArgs); 6583 } 6584 6585 if (UnresolvedMemberExpr *MemExpr = dyn_cast<UnresolvedMemberExpr>(E)) { 6586 // FIXME: avoid copy. 6587 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 6588 if (MemExpr->hasExplicitTemplateArgs()) { 6589 MemExpr->copyTemplateArgumentsInto(TemplateArgsBuffer); 6590 TemplateArgs = &TemplateArgsBuffer; 6591 } 6592 6593 Expr *Base; 6594 6595 // If we're filling in 6596 if (MemExpr->isImplicitAccess()) { 6597 if (cast<CXXMethodDecl>(Fn)->isStatic()) { 6598 return DeclRefExpr::Create(Context, 6599 MemExpr->getQualifier(), 6600 MemExpr->getQualifierRange(), 6601 Fn, 6602 MemExpr->getMemberLoc(), 6603 Fn->getType(), 6604 TemplateArgs); 6605 } else { 6606 SourceLocation Loc = MemExpr->getMemberLoc(); 6607 if (MemExpr->getQualifier()) 6608 Loc = MemExpr->getQualifierRange().getBegin(); 6609 Base = new (Context) CXXThisExpr(Loc, 6610 MemExpr->getBaseType(), 6611 /*isImplicit=*/true); 6612 } 6613 } else 6614 Base = MemExpr->getBase()->Retain(); 6615 6616 return MemberExpr::Create(Context, Base, 6617 MemExpr->isArrow(), 6618 MemExpr->getQualifier(), 6619 MemExpr->getQualifierRange(), 6620 Fn, 6621 MemExpr->getMemberLoc(), 6622 TemplateArgs, 6623 Fn->getType()); 6624 } 6625 6626 assert(false && "Invalid reference to overloaded function"); 6627 return E->Retain(); 6628} 6629 6630Sema::OwningExprResult Sema::FixOverloadedFunctionReference(OwningExprResult E, 6631 FunctionDecl *Fn) { 6632 return Owned(FixOverloadedFunctionReference((Expr *)E.get(), Fn)); 6633} 6634 6635} // end namespace clang 6636