SemaOverload.cpp revision b29b37d7e5bba50acc3a6642a2c90db080c22b90
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 ConvertedType = ToType; 1139 return true; 1140 } 1141 1142 if (Context.canAssignObjCInterfaces(FromObjCPtr, ToObjCPtr)) { 1143 // Okay: this is some kind of implicit downcast of Objective-C 1144 // interfaces, which is permitted. However, we're going to 1145 // complain about it. 1146 IncompatibleObjC = true; 1147 ConvertedType = FromType; 1148 return true; 1149 } 1150 } 1151 // Beyond this point, both types need to be C pointers or block pointers. 1152 QualType ToPointeeType; 1153 if (const PointerType *ToCPtr = ToType->getAs<PointerType>()) 1154 ToPointeeType = ToCPtr->getPointeeType(); 1155 else if (const BlockPointerType *ToBlockPtr = 1156 ToType->getAs<BlockPointerType>()) { 1157 // Objective C++: We're able to convert from a pointer to any object 1158 // to a block pointer type. 1159 if (FromObjCPtr && FromObjCPtr->isObjCBuiltinType()) { 1160 ConvertedType = ToType; 1161 return true; 1162 } 1163 ToPointeeType = ToBlockPtr->getPointeeType(); 1164 } 1165 else if (FromType->getAs<BlockPointerType>() && 1166 ToObjCPtr && ToObjCPtr->isObjCBuiltinType()) { 1167 // Objective C++: We're able to convert from a block pointer type to a 1168 // pointer to any object. 1169 ConvertedType = ToType; 1170 return true; 1171 } 1172 else 1173 return false; 1174 1175 QualType FromPointeeType; 1176 if (const PointerType *FromCPtr = FromType->getAs<PointerType>()) 1177 FromPointeeType = FromCPtr->getPointeeType(); 1178 else if (const BlockPointerType *FromBlockPtr = FromType->getAs<BlockPointerType>()) 1179 FromPointeeType = FromBlockPtr->getPointeeType(); 1180 else 1181 return false; 1182 1183 // If we have pointers to pointers, recursively check whether this 1184 // is an Objective-C conversion. 1185 if (FromPointeeType->isPointerType() && ToPointeeType->isPointerType() && 1186 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, 1187 IncompatibleObjC)) { 1188 // We always complain about this conversion. 1189 IncompatibleObjC = true; 1190 ConvertedType = ToType; 1191 return true; 1192 } 1193 // Allow conversion of pointee being objective-c pointer to another one; 1194 // as in I* to id. 1195 if (FromPointeeType->getAs<ObjCObjectPointerType>() && 1196 ToPointeeType->getAs<ObjCObjectPointerType>() && 1197 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, 1198 IncompatibleObjC)) { 1199 ConvertedType = ToType; 1200 return true; 1201 } 1202 1203 // If we have pointers to functions or blocks, check whether the only 1204 // differences in the argument and result types are in Objective-C 1205 // pointer conversions. If so, we permit the conversion (but 1206 // complain about it). 1207 const FunctionProtoType *FromFunctionType 1208 = FromPointeeType->getAs<FunctionProtoType>(); 1209 const FunctionProtoType *ToFunctionType 1210 = ToPointeeType->getAs<FunctionProtoType>(); 1211 if (FromFunctionType && ToFunctionType) { 1212 // If the function types are exactly the same, this isn't an 1213 // Objective-C pointer conversion. 1214 if (Context.getCanonicalType(FromPointeeType) 1215 == Context.getCanonicalType(ToPointeeType)) 1216 return false; 1217 1218 // Perform the quick checks that will tell us whether these 1219 // function types are obviously different. 1220 if (FromFunctionType->getNumArgs() != ToFunctionType->getNumArgs() || 1221 FromFunctionType->isVariadic() != ToFunctionType->isVariadic() || 1222 FromFunctionType->getTypeQuals() != ToFunctionType->getTypeQuals()) 1223 return false; 1224 1225 bool HasObjCConversion = false; 1226 if (Context.getCanonicalType(FromFunctionType->getResultType()) 1227 == Context.getCanonicalType(ToFunctionType->getResultType())) { 1228 // Okay, the types match exactly. Nothing to do. 1229 } else if (isObjCPointerConversion(FromFunctionType->getResultType(), 1230 ToFunctionType->getResultType(), 1231 ConvertedType, IncompatibleObjC)) { 1232 // Okay, we have an Objective-C pointer conversion. 1233 HasObjCConversion = true; 1234 } else { 1235 // Function types are too different. Abort. 1236 return false; 1237 } 1238 1239 // Check argument types. 1240 for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumArgs(); 1241 ArgIdx != NumArgs; ++ArgIdx) { 1242 QualType FromArgType = FromFunctionType->getArgType(ArgIdx); 1243 QualType ToArgType = ToFunctionType->getArgType(ArgIdx); 1244 if (Context.getCanonicalType(FromArgType) 1245 == Context.getCanonicalType(ToArgType)) { 1246 // Okay, the types match exactly. Nothing to do. 1247 } else if (isObjCPointerConversion(FromArgType, ToArgType, 1248 ConvertedType, IncompatibleObjC)) { 1249 // Okay, we have an Objective-C pointer conversion. 1250 HasObjCConversion = true; 1251 } else { 1252 // Argument types are too different. Abort. 1253 return false; 1254 } 1255 } 1256 1257 if (HasObjCConversion) { 1258 // We had an Objective-C conversion. Allow this pointer 1259 // conversion, but complain about it. 1260 ConvertedType = ToType; 1261 IncompatibleObjC = true; 1262 return true; 1263 } 1264 } 1265 1266 return false; 1267} 1268 1269/// CheckPointerConversion - Check the pointer conversion from the 1270/// expression From to the type ToType. This routine checks for 1271/// ambiguous or inaccessible derived-to-base pointer 1272/// conversions for which IsPointerConversion has already returned 1273/// true. It returns true and produces a diagnostic if there was an 1274/// error, or returns false otherwise. 1275bool Sema::CheckPointerConversion(Expr *From, QualType ToType, 1276 CastExpr::CastKind &Kind, 1277 bool IgnoreBaseAccess) { 1278 QualType FromType = From->getType(); 1279 1280 if (const PointerType *FromPtrType = FromType->getAs<PointerType>()) 1281 if (const PointerType *ToPtrType = ToType->getAs<PointerType>()) { 1282 QualType FromPointeeType = FromPtrType->getPointeeType(), 1283 ToPointeeType = ToPtrType->getPointeeType(); 1284 1285 if (FromPointeeType->isRecordType() && 1286 ToPointeeType->isRecordType()) { 1287 // We must have a derived-to-base conversion. Check an 1288 // ambiguous or inaccessible conversion. 1289 if (CheckDerivedToBaseConversion(FromPointeeType, ToPointeeType, 1290 From->getExprLoc(), 1291 From->getSourceRange(), 1292 IgnoreBaseAccess)) 1293 return true; 1294 1295 // The conversion was successful. 1296 Kind = CastExpr::CK_DerivedToBase; 1297 } 1298 } 1299 if (const ObjCObjectPointerType *FromPtrType = 1300 FromType->getAs<ObjCObjectPointerType>()) 1301 if (const ObjCObjectPointerType *ToPtrType = 1302 ToType->getAs<ObjCObjectPointerType>()) { 1303 // Objective-C++ conversions are always okay. 1304 // FIXME: We should have a different class of conversions for the 1305 // Objective-C++ implicit conversions. 1306 if (FromPtrType->isObjCBuiltinType() || ToPtrType->isObjCBuiltinType()) 1307 return false; 1308 1309 } 1310 return false; 1311} 1312 1313/// IsMemberPointerConversion - Determines whether the conversion of the 1314/// expression From, which has the (possibly adjusted) type FromType, can be 1315/// converted to the type ToType via a member pointer conversion (C++ 4.11). 1316/// If so, returns true and places the converted type (that might differ from 1317/// ToType in its cv-qualifiers at some level) into ConvertedType. 1318bool Sema::IsMemberPointerConversion(Expr *From, QualType FromType, 1319 QualType ToType, 1320 bool InOverloadResolution, 1321 QualType &ConvertedType) { 1322 const MemberPointerType *ToTypePtr = ToType->getAs<MemberPointerType>(); 1323 if (!ToTypePtr) 1324 return false; 1325 1326 // A null pointer constant can be converted to a member pointer (C++ 4.11p1) 1327 if (From->isNullPointerConstant(Context, 1328 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull 1329 : Expr::NPC_ValueDependentIsNull)) { 1330 ConvertedType = ToType; 1331 return true; 1332 } 1333 1334 // Otherwise, both types have to be member pointers. 1335 const MemberPointerType *FromTypePtr = FromType->getAs<MemberPointerType>(); 1336 if (!FromTypePtr) 1337 return false; 1338 1339 // A pointer to member of B can be converted to a pointer to member of D, 1340 // where D is derived from B (C++ 4.11p2). 1341 QualType FromClass(FromTypePtr->getClass(), 0); 1342 QualType ToClass(ToTypePtr->getClass(), 0); 1343 // FIXME: What happens when these are dependent? Is this function even called? 1344 1345 if (IsDerivedFrom(ToClass, FromClass)) { 1346 ConvertedType = Context.getMemberPointerType(FromTypePtr->getPointeeType(), 1347 ToClass.getTypePtr()); 1348 return true; 1349 } 1350 1351 return false; 1352} 1353 1354/// CheckMemberPointerConversion - Check the member pointer conversion from the 1355/// expression From to the type ToType. This routine checks for ambiguous or 1356/// virtual or inaccessible base-to-derived member pointer conversions 1357/// for which IsMemberPointerConversion has already returned true. It returns 1358/// true and produces a diagnostic if there was an error, or returns false 1359/// otherwise. 1360bool Sema::CheckMemberPointerConversion(Expr *From, QualType ToType, 1361 CastExpr::CastKind &Kind, 1362 bool IgnoreBaseAccess) { 1363 QualType FromType = From->getType(); 1364 const MemberPointerType *FromPtrType = FromType->getAs<MemberPointerType>(); 1365 if (!FromPtrType) { 1366 // This must be a null pointer to member pointer conversion 1367 assert(From->isNullPointerConstant(Context, 1368 Expr::NPC_ValueDependentIsNull) && 1369 "Expr must be null pointer constant!"); 1370 Kind = CastExpr::CK_NullToMemberPointer; 1371 return false; 1372 } 1373 1374 const MemberPointerType *ToPtrType = ToType->getAs<MemberPointerType>(); 1375 assert(ToPtrType && "No member pointer cast has a target type " 1376 "that is not a member pointer."); 1377 1378 QualType FromClass = QualType(FromPtrType->getClass(), 0); 1379 QualType ToClass = QualType(ToPtrType->getClass(), 0); 1380 1381 // FIXME: What about dependent types? 1382 assert(FromClass->isRecordType() && "Pointer into non-class."); 1383 assert(ToClass->isRecordType() && "Pointer into non-class."); 1384 1385 CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/ true, 1386 /*DetectVirtual=*/true); 1387 bool DerivationOkay = IsDerivedFrom(ToClass, FromClass, Paths); 1388 assert(DerivationOkay && 1389 "Should not have been called if derivation isn't OK."); 1390 (void)DerivationOkay; 1391 1392 if (Paths.isAmbiguous(Context.getCanonicalType(FromClass). 1393 getUnqualifiedType())) { 1394 std::string PathDisplayStr = getAmbiguousPathsDisplayString(Paths); 1395 Diag(From->getExprLoc(), diag::err_ambiguous_memptr_conv) 1396 << 0 << FromClass << ToClass << PathDisplayStr << From->getSourceRange(); 1397 return true; 1398 } 1399 1400 if (const RecordType *VBase = Paths.getDetectedVirtual()) { 1401 Diag(From->getExprLoc(), diag::err_memptr_conv_via_virtual) 1402 << FromClass << ToClass << QualType(VBase, 0) 1403 << From->getSourceRange(); 1404 return true; 1405 } 1406 1407 if (!IgnoreBaseAccess) 1408 CheckBaseClassAccess(From->getExprLoc(), /*BaseToDerived*/ true, 1409 FromClass, ToClass, Paths.front()); 1410 1411 // Must be a base to derived member conversion. 1412 Kind = CastExpr::CK_BaseToDerivedMemberPointer; 1413 return false; 1414} 1415 1416/// IsQualificationConversion - Determines whether the conversion from 1417/// an rvalue of type FromType to ToType is a qualification conversion 1418/// (C++ 4.4). 1419bool 1420Sema::IsQualificationConversion(QualType FromType, QualType ToType) { 1421 FromType = Context.getCanonicalType(FromType); 1422 ToType = Context.getCanonicalType(ToType); 1423 1424 // If FromType and ToType are the same type, this is not a 1425 // qualification conversion. 1426 if (FromType.getUnqualifiedType() == ToType.getUnqualifiedType()) 1427 return false; 1428 1429 // (C++ 4.4p4): 1430 // A conversion can add cv-qualifiers at levels other than the first 1431 // in multi-level pointers, subject to the following rules: [...] 1432 bool PreviousToQualsIncludeConst = true; 1433 bool UnwrappedAnyPointer = false; 1434 while (UnwrapSimilarPointerTypes(FromType, ToType)) { 1435 // Within each iteration of the loop, we check the qualifiers to 1436 // determine if this still looks like a qualification 1437 // conversion. Then, if all is well, we unwrap one more level of 1438 // pointers or pointers-to-members and do it all again 1439 // until there are no more pointers or pointers-to-members left to 1440 // unwrap. 1441 UnwrappedAnyPointer = true; 1442 1443 // -- for every j > 0, if const is in cv 1,j then const is in cv 1444 // 2,j, and similarly for volatile. 1445 if (!ToType.isAtLeastAsQualifiedAs(FromType)) 1446 return false; 1447 1448 // -- if the cv 1,j and cv 2,j are different, then const is in 1449 // every cv for 0 < k < j. 1450 if (FromType.getCVRQualifiers() != ToType.getCVRQualifiers() 1451 && !PreviousToQualsIncludeConst) 1452 return false; 1453 1454 // Keep track of whether all prior cv-qualifiers in the "to" type 1455 // include const. 1456 PreviousToQualsIncludeConst 1457 = PreviousToQualsIncludeConst && ToType.isConstQualified(); 1458 } 1459 1460 // We are left with FromType and ToType being the pointee types 1461 // after unwrapping the original FromType and ToType the same number 1462 // of types. If we unwrapped any pointers, and if FromType and 1463 // ToType have the same unqualified type (since we checked 1464 // qualifiers above), then this is a qualification conversion. 1465 return UnwrappedAnyPointer && Context.hasSameUnqualifiedType(FromType,ToType); 1466} 1467 1468/// Determines whether there is a user-defined conversion sequence 1469/// (C++ [over.ics.user]) that converts expression From to the type 1470/// ToType. If such a conversion exists, User will contain the 1471/// user-defined conversion sequence that performs such a conversion 1472/// and this routine will return true. Otherwise, this routine returns 1473/// false and User is unspecified. 1474/// 1475/// \param AllowConversionFunctions true if the conversion should 1476/// consider conversion functions at all. If false, only constructors 1477/// will be considered. 1478/// 1479/// \param AllowExplicit true if the conversion should consider C++0x 1480/// "explicit" conversion functions as well as non-explicit conversion 1481/// functions (C++0x [class.conv.fct]p2). 1482/// 1483/// \param ForceRValue true if the expression should be treated as an rvalue 1484/// for overload resolution. 1485/// \param UserCast true if looking for user defined conversion for a static 1486/// cast. 1487OverloadingResult Sema::IsUserDefinedConversion(Expr *From, QualType ToType, 1488 UserDefinedConversionSequence& User, 1489 OverloadCandidateSet& CandidateSet, 1490 bool AllowConversionFunctions, 1491 bool AllowExplicit, 1492 bool ForceRValue, 1493 bool UserCast) { 1494 if (const RecordType *ToRecordType = ToType->getAs<RecordType>()) { 1495 if (RequireCompleteType(From->getLocStart(), ToType, PDiag())) { 1496 // We're not going to find any constructors. 1497 } else if (CXXRecordDecl *ToRecordDecl 1498 = dyn_cast<CXXRecordDecl>(ToRecordType->getDecl())) { 1499 // C++ [over.match.ctor]p1: 1500 // When objects of class type are direct-initialized (8.5), or 1501 // copy-initialized from an expression of the same or a 1502 // derived class type (8.5), overload resolution selects the 1503 // constructor. [...] For copy-initialization, the candidate 1504 // functions are all the converting constructors (12.3.1) of 1505 // that class. The argument list is the expression-list within 1506 // the parentheses of the initializer. 1507 bool SuppressUserConversions = !UserCast; 1508 if (Context.hasSameUnqualifiedType(ToType, From->getType()) || 1509 IsDerivedFrom(From->getType(), ToType)) { 1510 SuppressUserConversions = false; 1511 AllowConversionFunctions = false; 1512 } 1513 1514 DeclarationName ConstructorName 1515 = Context.DeclarationNames.getCXXConstructorName( 1516 Context.getCanonicalType(ToType).getUnqualifiedType()); 1517 DeclContext::lookup_iterator Con, ConEnd; 1518 for (llvm::tie(Con, ConEnd) 1519 = ToRecordDecl->lookup(ConstructorName); 1520 Con != ConEnd; ++Con) { 1521 // Find the constructor (which may be a template). 1522 CXXConstructorDecl *Constructor = 0; 1523 FunctionTemplateDecl *ConstructorTmpl 1524 = dyn_cast<FunctionTemplateDecl>(*Con); 1525 if (ConstructorTmpl) 1526 Constructor 1527 = cast<CXXConstructorDecl>(ConstructorTmpl->getTemplatedDecl()); 1528 else 1529 Constructor = cast<CXXConstructorDecl>(*Con); 1530 1531 if (!Constructor->isInvalidDecl() && 1532 Constructor->isConvertingConstructor(AllowExplicit)) { 1533 if (ConstructorTmpl) 1534 AddTemplateOverloadCandidate(ConstructorTmpl, 1535 ConstructorTmpl->getAccess(), 1536 /*ExplicitArgs*/ 0, 1537 &From, 1, CandidateSet, 1538 SuppressUserConversions, ForceRValue); 1539 else 1540 // Allow one user-defined conversion when user specifies a 1541 // From->ToType conversion via an static cast (c-style, etc). 1542 AddOverloadCandidate(Constructor, Constructor->getAccess(), 1543 &From, 1, CandidateSet, 1544 SuppressUserConversions, ForceRValue); 1545 } 1546 } 1547 } 1548 } 1549 1550 if (!AllowConversionFunctions) { 1551 // Don't allow any conversion functions to enter the overload set. 1552 } else if (RequireCompleteType(From->getLocStart(), From->getType(), 1553 PDiag(0) 1554 << From->getSourceRange())) { 1555 // No conversion functions from incomplete types. 1556 } else if (const RecordType *FromRecordType 1557 = From->getType()->getAs<RecordType>()) { 1558 if (CXXRecordDecl *FromRecordDecl 1559 = dyn_cast<CXXRecordDecl>(FromRecordType->getDecl())) { 1560 // Add all of the conversion functions as candidates. 1561 const UnresolvedSetImpl *Conversions 1562 = FromRecordDecl->getVisibleConversionFunctions(); 1563 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 1564 E = Conversions->end(); I != E; ++I) { 1565 NamedDecl *D = *I; 1566 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext()); 1567 if (isa<UsingShadowDecl>(D)) 1568 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 1569 1570 CXXConversionDecl *Conv; 1571 FunctionTemplateDecl *ConvTemplate; 1572 if ((ConvTemplate = dyn_cast<FunctionTemplateDecl>(*I))) 1573 Conv = dyn_cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 1574 else 1575 Conv = dyn_cast<CXXConversionDecl>(*I); 1576 1577 if (AllowExplicit || !Conv->isExplicit()) { 1578 if (ConvTemplate) 1579 AddTemplateConversionCandidate(ConvTemplate, I.getAccess(), 1580 ActingContext, From, ToType, 1581 CandidateSet); 1582 else 1583 AddConversionCandidate(Conv, I.getAccess(), ActingContext, 1584 From, ToType, CandidateSet); 1585 } 1586 } 1587 } 1588 } 1589 1590 OverloadCandidateSet::iterator Best; 1591 switch (BestViableFunction(CandidateSet, From->getLocStart(), Best)) { 1592 case OR_Success: 1593 // Record the standard conversion we used and the conversion function. 1594 if (CXXConstructorDecl *Constructor 1595 = dyn_cast<CXXConstructorDecl>(Best->Function)) { 1596 // C++ [over.ics.user]p1: 1597 // If the user-defined conversion is specified by a 1598 // constructor (12.3.1), the initial standard conversion 1599 // sequence converts the source type to the type required by 1600 // the argument of the constructor. 1601 // 1602 QualType ThisType = Constructor->getThisType(Context); 1603 if (Best->Conversions[0].isEllipsis()) 1604 User.EllipsisConversion = true; 1605 else { 1606 User.Before = Best->Conversions[0].Standard; 1607 User.EllipsisConversion = false; 1608 } 1609 User.ConversionFunction = Constructor; 1610 User.After.setAsIdentityConversion(); 1611 User.After.setFromType( 1612 ThisType->getAs<PointerType>()->getPointeeType()); 1613 User.After.setAllToTypes(ToType); 1614 return OR_Success; 1615 } else if (CXXConversionDecl *Conversion 1616 = dyn_cast<CXXConversionDecl>(Best->Function)) { 1617 // C++ [over.ics.user]p1: 1618 // 1619 // [...] If the user-defined conversion is specified by a 1620 // conversion function (12.3.2), the initial standard 1621 // conversion sequence converts the source type to the 1622 // implicit object parameter of the conversion function. 1623 User.Before = Best->Conversions[0].Standard; 1624 User.ConversionFunction = Conversion; 1625 User.EllipsisConversion = false; 1626 1627 // C++ [over.ics.user]p2: 1628 // The second standard conversion sequence converts the 1629 // result of the user-defined conversion to the target type 1630 // for the sequence. Since an implicit conversion sequence 1631 // is an initialization, the special rules for 1632 // initialization by user-defined conversion apply when 1633 // selecting the best user-defined conversion for a 1634 // user-defined conversion sequence (see 13.3.3 and 1635 // 13.3.3.1). 1636 User.After = Best->FinalConversion; 1637 return OR_Success; 1638 } else { 1639 assert(false && "Not a constructor or conversion function?"); 1640 return OR_No_Viable_Function; 1641 } 1642 1643 case OR_No_Viable_Function: 1644 return OR_No_Viable_Function; 1645 case OR_Deleted: 1646 // No conversion here! We're done. 1647 return OR_Deleted; 1648 1649 case OR_Ambiguous: 1650 return OR_Ambiguous; 1651 } 1652 1653 return OR_No_Viable_Function; 1654} 1655 1656bool 1657Sema::DiagnoseMultipleUserDefinedConversion(Expr *From, QualType ToType) { 1658 ImplicitConversionSequence ICS; 1659 OverloadCandidateSet CandidateSet(From->getExprLoc()); 1660 OverloadingResult OvResult = 1661 IsUserDefinedConversion(From, ToType, ICS.UserDefined, 1662 CandidateSet, true, false, false); 1663 if (OvResult == OR_Ambiguous) 1664 Diag(From->getSourceRange().getBegin(), 1665 diag::err_typecheck_ambiguous_condition) 1666 << From->getType() << ToType << From->getSourceRange(); 1667 else if (OvResult == OR_No_Viable_Function && !CandidateSet.empty()) 1668 Diag(From->getSourceRange().getBegin(), 1669 diag::err_typecheck_nonviable_condition) 1670 << From->getType() << ToType << From->getSourceRange(); 1671 else 1672 return false; 1673 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, &From, 1); 1674 return true; 1675} 1676 1677/// CompareImplicitConversionSequences - Compare two implicit 1678/// conversion sequences to determine whether one is better than the 1679/// other or if they are indistinguishable (C++ 13.3.3.2). 1680ImplicitConversionSequence::CompareKind 1681Sema::CompareImplicitConversionSequences(const ImplicitConversionSequence& ICS1, 1682 const ImplicitConversionSequence& ICS2) 1683{ 1684 // (C++ 13.3.3.2p2): When comparing the basic forms of implicit 1685 // conversion sequences (as defined in 13.3.3.1) 1686 // -- a standard conversion sequence (13.3.3.1.1) is a better 1687 // conversion sequence than a user-defined conversion sequence or 1688 // an ellipsis conversion sequence, and 1689 // -- a user-defined conversion sequence (13.3.3.1.2) is a better 1690 // conversion sequence than an ellipsis conversion sequence 1691 // (13.3.3.1.3). 1692 // 1693 // C++0x [over.best.ics]p10: 1694 // For the purpose of ranking implicit conversion sequences as 1695 // described in 13.3.3.2, the ambiguous conversion sequence is 1696 // treated as a user-defined sequence that is indistinguishable 1697 // from any other user-defined conversion sequence. 1698 if (ICS1.getKind() < ICS2.getKind()) { 1699 if (!(ICS1.isUserDefined() && ICS2.isAmbiguous())) 1700 return ImplicitConversionSequence::Better; 1701 } else if (ICS2.getKind() < ICS1.getKind()) { 1702 if (!(ICS2.isUserDefined() && ICS1.isAmbiguous())) 1703 return ImplicitConversionSequence::Worse; 1704 } 1705 1706 if (ICS1.isAmbiguous() || ICS2.isAmbiguous()) 1707 return ImplicitConversionSequence::Indistinguishable; 1708 1709 // Two implicit conversion sequences of the same form are 1710 // indistinguishable conversion sequences unless one of the 1711 // following rules apply: (C++ 13.3.3.2p3): 1712 if (ICS1.isStandard()) 1713 return CompareStandardConversionSequences(ICS1.Standard, ICS2.Standard); 1714 else if (ICS1.isUserDefined()) { 1715 // User-defined conversion sequence U1 is a better conversion 1716 // sequence than another user-defined conversion sequence U2 if 1717 // they contain the same user-defined conversion function or 1718 // constructor and if the second standard conversion sequence of 1719 // U1 is better than the second standard conversion sequence of 1720 // U2 (C++ 13.3.3.2p3). 1721 if (ICS1.UserDefined.ConversionFunction == 1722 ICS2.UserDefined.ConversionFunction) 1723 return CompareStandardConversionSequences(ICS1.UserDefined.After, 1724 ICS2.UserDefined.After); 1725 } 1726 1727 return ImplicitConversionSequence::Indistinguishable; 1728} 1729 1730// Per 13.3.3.2p3, compare the given standard conversion sequences to 1731// determine if one is a proper subset of the other. 1732static ImplicitConversionSequence::CompareKind 1733compareStandardConversionSubsets(ASTContext &Context, 1734 const StandardConversionSequence& SCS1, 1735 const StandardConversionSequence& SCS2) { 1736 ImplicitConversionSequence::CompareKind Result 1737 = ImplicitConversionSequence::Indistinguishable; 1738 1739 if (SCS1.Second != SCS2.Second) { 1740 if (SCS1.Second == ICK_Identity) 1741 Result = ImplicitConversionSequence::Better; 1742 else if (SCS2.Second == ICK_Identity) 1743 Result = ImplicitConversionSequence::Worse; 1744 else 1745 return ImplicitConversionSequence::Indistinguishable; 1746 } else if (!Context.hasSameType(SCS1.getToType(1), SCS2.getToType(1))) 1747 return ImplicitConversionSequence::Indistinguishable; 1748 1749 if (SCS1.Third == SCS2.Third) { 1750 return Context.hasSameType(SCS1.getToType(2), SCS2.getToType(2))? Result 1751 : ImplicitConversionSequence::Indistinguishable; 1752 } 1753 1754 if (SCS1.Third == ICK_Identity) 1755 return Result == ImplicitConversionSequence::Worse 1756 ? ImplicitConversionSequence::Indistinguishable 1757 : ImplicitConversionSequence::Better; 1758 1759 if (SCS2.Third == ICK_Identity) 1760 return Result == ImplicitConversionSequence::Better 1761 ? ImplicitConversionSequence::Indistinguishable 1762 : ImplicitConversionSequence::Worse; 1763 1764 return ImplicitConversionSequence::Indistinguishable; 1765} 1766 1767/// CompareStandardConversionSequences - Compare two standard 1768/// conversion sequences to determine whether one is better than the 1769/// other or if they are indistinguishable (C++ 13.3.3.2p3). 1770ImplicitConversionSequence::CompareKind 1771Sema::CompareStandardConversionSequences(const StandardConversionSequence& SCS1, 1772 const StandardConversionSequence& SCS2) 1773{ 1774 // Standard conversion sequence S1 is a better conversion sequence 1775 // than standard conversion sequence S2 if (C++ 13.3.3.2p3): 1776 1777 // -- S1 is a proper subsequence of S2 (comparing the conversion 1778 // sequences in the canonical form defined by 13.3.3.1.1, 1779 // excluding any Lvalue Transformation; the identity conversion 1780 // sequence is considered to be a subsequence of any 1781 // non-identity conversion sequence) or, if not that, 1782 if (ImplicitConversionSequence::CompareKind CK 1783 = compareStandardConversionSubsets(Context, SCS1, SCS2)) 1784 return CK; 1785 1786 // -- the rank of S1 is better than the rank of S2 (by the rules 1787 // defined below), or, if not that, 1788 ImplicitConversionRank Rank1 = SCS1.getRank(); 1789 ImplicitConversionRank Rank2 = SCS2.getRank(); 1790 if (Rank1 < Rank2) 1791 return ImplicitConversionSequence::Better; 1792 else if (Rank2 < Rank1) 1793 return ImplicitConversionSequence::Worse; 1794 1795 // (C++ 13.3.3.2p4): Two conversion sequences with the same rank 1796 // are indistinguishable unless one of the following rules 1797 // applies: 1798 1799 // A conversion that is not a conversion of a pointer, or 1800 // pointer to member, to bool is better than another conversion 1801 // that is such a conversion. 1802 if (SCS1.isPointerConversionToBool() != SCS2.isPointerConversionToBool()) 1803 return SCS2.isPointerConversionToBool() 1804 ? ImplicitConversionSequence::Better 1805 : ImplicitConversionSequence::Worse; 1806 1807 // C++ [over.ics.rank]p4b2: 1808 // 1809 // If class B is derived directly or indirectly from class A, 1810 // conversion of B* to A* is better than conversion of B* to 1811 // void*, and conversion of A* to void* is better than conversion 1812 // of B* to void*. 1813 bool SCS1ConvertsToVoid 1814 = SCS1.isPointerConversionToVoidPointer(Context); 1815 bool SCS2ConvertsToVoid 1816 = SCS2.isPointerConversionToVoidPointer(Context); 1817 if (SCS1ConvertsToVoid != SCS2ConvertsToVoid) { 1818 // Exactly one of the conversion sequences is a conversion to 1819 // a void pointer; it's the worse conversion. 1820 return SCS2ConvertsToVoid ? ImplicitConversionSequence::Better 1821 : ImplicitConversionSequence::Worse; 1822 } else if (!SCS1ConvertsToVoid && !SCS2ConvertsToVoid) { 1823 // Neither conversion sequence converts to a void pointer; compare 1824 // their derived-to-base conversions. 1825 if (ImplicitConversionSequence::CompareKind DerivedCK 1826 = CompareDerivedToBaseConversions(SCS1, SCS2)) 1827 return DerivedCK; 1828 } else if (SCS1ConvertsToVoid && SCS2ConvertsToVoid) { 1829 // Both conversion sequences are conversions to void 1830 // pointers. Compare the source types to determine if there's an 1831 // inheritance relationship in their sources. 1832 QualType FromType1 = SCS1.getFromType(); 1833 QualType FromType2 = SCS2.getFromType(); 1834 1835 // Adjust the types we're converting from via the array-to-pointer 1836 // conversion, if we need to. 1837 if (SCS1.First == ICK_Array_To_Pointer) 1838 FromType1 = Context.getArrayDecayedType(FromType1); 1839 if (SCS2.First == ICK_Array_To_Pointer) 1840 FromType2 = Context.getArrayDecayedType(FromType2); 1841 1842 QualType FromPointee1 1843 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1844 QualType FromPointee2 1845 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1846 1847 if (IsDerivedFrom(FromPointee2, FromPointee1)) 1848 return ImplicitConversionSequence::Better; 1849 else if (IsDerivedFrom(FromPointee1, FromPointee2)) 1850 return ImplicitConversionSequence::Worse; 1851 1852 // Objective-C++: If one interface is more specific than the 1853 // other, it is the better one. 1854 const ObjCInterfaceType* FromIface1 = FromPointee1->getAs<ObjCInterfaceType>(); 1855 const ObjCInterfaceType* FromIface2 = FromPointee2->getAs<ObjCInterfaceType>(); 1856 if (FromIface1 && FromIface1) { 1857 if (Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 1858 return ImplicitConversionSequence::Better; 1859 else if (Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 1860 return ImplicitConversionSequence::Worse; 1861 } 1862 } 1863 1864 // Compare based on qualification conversions (C++ 13.3.3.2p3, 1865 // bullet 3). 1866 if (ImplicitConversionSequence::CompareKind QualCK 1867 = CompareQualificationConversions(SCS1, SCS2)) 1868 return QualCK; 1869 1870 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding) { 1871 // C++0x [over.ics.rank]p3b4: 1872 // -- S1 and S2 are reference bindings (8.5.3) and neither refers to an 1873 // implicit object parameter of a non-static member function declared 1874 // without a ref-qualifier, and S1 binds an rvalue reference to an 1875 // rvalue and S2 binds an lvalue reference. 1876 // FIXME: We don't know if we're dealing with the implicit object parameter, 1877 // or if the member function in this case has a ref qualifier. 1878 // (Of course, we don't have ref qualifiers yet.) 1879 if (SCS1.RRefBinding != SCS2.RRefBinding) 1880 return SCS1.RRefBinding ? ImplicitConversionSequence::Better 1881 : ImplicitConversionSequence::Worse; 1882 1883 // C++ [over.ics.rank]p3b4: 1884 // -- S1 and S2 are reference bindings (8.5.3), and the types to 1885 // which the references refer are the same type except for 1886 // top-level cv-qualifiers, and the type to which the reference 1887 // initialized by S2 refers is more cv-qualified than the type 1888 // to which the reference initialized by S1 refers. 1889 QualType T1 = SCS1.getToType(2); 1890 QualType T2 = SCS2.getToType(2); 1891 T1 = Context.getCanonicalType(T1); 1892 T2 = Context.getCanonicalType(T2); 1893 Qualifiers T1Quals, T2Quals; 1894 QualType UnqualT1 = Context.getUnqualifiedArrayType(T1, T1Quals); 1895 QualType UnqualT2 = Context.getUnqualifiedArrayType(T2, T2Quals); 1896 if (UnqualT1 == UnqualT2) { 1897 // If the type is an array type, promote the element qualifiers to the type 1898 // for comparison. 1899 if (isa<ArrayType>(T1) && T1Quals) 1900 T1 = Context.getQualifiedType(UnqualT1, T1Quals); 1901 if (isa<ArrayType>(T2) && T2Quals) 1902 T2 = Context.getQualifiedType(UnqualT2, T2Quals); 1903 if (T2.isMoreQualifiedThan(T1)) 1904 return ImplicitConversionSequence::Better; 1905 else if (T1.isMoreQualifiedThan(T2)) 1906 return ImplicitConversionSequence::Worse; 1907 } 1908 } 1909 1910 return ImplicitConversionSequence::Indistinguishable; 1911} 1912 1913/// CompareQualificationConversions - Compares two standard conversion 1914/// sequences to determine whether they can be ranked based on their 1915/// qualification conversions (C++ 13.3.3.2p3 bullet 3). 1916ImplicitConversionSequence::CompareKind 1917Sema::CompareQualificationConversions(const StandardConversionSequence& SCS1, 1918 const StandardConversionSequence& SCS2) { 1919 // C++ 13.3.3.2p3: 1920 // -- S1 and S2 differ only in their qualification conversion and 1921 // yield similar types T1 and T2 (C++ 4.4), respectively, and the 1922 // cv-qualification signature of type T1 is a proper subset of 1923 // the cv-qualification signature of type T2, and S1 is not the 1924 // deprecated string literal array-to-pointer conversion (4.2). 1925 if (SCS1.First != SCS2.First || SCS1.Second != SCS2.Second || 1926 SCS1.Third != SCS2.Third || SCS1.Third != ICK_Qualification) 1927 return ImplicitConversionSequence::Indistinguishable; 1928 1929 // FIXME: the example in the standard doesn't use a qualification 1930 // conversion (!) 1931 QualType T1 = SCS1.getToType(2); 1932 QualType T2 = SCS2.getToType(2); 1933 T1 = Context.getCanonicalType(T1); 1934 T2 = Context.getCanonicalType(T2); 1935 Qualifiers T1Quals, T2Quals; 1936 QualType UnqualT1 = Context.getUnqualifiedArrayType(T1, T1Quals); 1937 QualType UnqualT2 = Context.getUnqualifiedArrayType(T2, T2Quals); 1938 1939 // If the types are the same, we won't learn anything by unwrapped 1940 // them. 1941 if (UnqualT1 == UnqualT2) 1942 return ImplicitConversionSequence::Indistinguishable; 1943 1944 // If the type is an array type, promote the element qualifiers to the type 1945 // for comparison. 1946 if (isa<ArrayType>(T1) && T1Quals) 1947 T1 = Context.getQualifiedType(UnqualT1, T1Quals); 1948 if (isa<ArrayType>(T2) && T2Quals) 1949 T2 = Context.getQualifiedType(UnqualT2, T2Quals); 1950 1951 ImplicitConversionSequence::CompareKind Result 1952 = ImplicitConversionSequence::Indistinguishable; 1953 while (UnwrapSimilarPointerTypes(T1, T2)) { 1954 // Within each iteration of the loop, we check the qualifiers to 1955 // determine if this still looks like a qualification 1956 // conversion. Then, if all is well, we unwrap one more level of 1957 // pointers or pointers-to-members and do it all again 1958 // until there are no more pointers or pointers-to-members left 1959 // to unwrap. This essentially mimics what 1960 // IsQualificationConversion does, but here we're checking for a 1961 // strict subset of qualifiers. 1962 if (T1.getCVRQualifiers() == T2.getCVRQualifiers()) 1963 // The qualifiers are the same, so this doesn't tell us anything 1964 // about how the sequences rank. 1965 ; 1966 else if (T2.isMoreQualifiedThan(T1)) { 1967 // T1 has fewer qualifiers, so it could be the better sequence. 1968 if (Result == ImplicitConversionSequence::Worse) 1969 // Neither has qualifiers that are a subset of the other's 1970 // qualifiers. 1971 return ImplicitConversionSequence::Indistinguishable; 1972 1973 Result = ImplicitConversionSequence::Better; 1974 } else if (T1.isMoreQualifiedThan(T2)) { 1975 // T2 has fewer qualifiers, so it could be the better sequence. 1976 if (Result == ImplicitConversionSequence::Better) 1977 // Neither has qualifiers that are a subset of the other's 1978 // qualifiers. 1979 return ImplicitConversionSequence::Indistinguishable; 1980 1981 Result = ImplicitConversionSequence::Worse; 1982 } else { 1983 // Qualifiers are disjoint. 1984 return ImplicitConversionSequence::Indistinguishable; 1985 } 1986 1987 // If the types after this point are equivalent, we're done. 1988 if (Context.hasSameUnqualifiedType(T1, T2)) 1989 break; 1990 } 1991 1992 // Check that the winning standard conversion sequence isn't using 1993 // the deprecated string literal array to pointer conversion. 1994 switch (Result) { 1995 case ImplicitConversionSequence::Better: 1996 if (SCS1.DeprecatedStringLiteralToCharPtr) 1997 Result = ImplicitConversionSequence::Indistinguishable; 1998 break; 1999 2000 case ImplicitConversionSequence::Indistinguishable: 2001 break; 2002 2003 case ImplicitConversionSequence::Worse: 2004 if (SCS2.DeprecatedStringLiteralToCharPtr) 2005 Result = ImplicitConversionSequence::Indistinguishable; 2006 break; 2007 } 2008 2009 return Result; 2010} 2011 2012/// CompareDerivedToBaseConversions - Compares two standard conversion 2013/// sequences to determine whether they can be ranked based on their 2014/// various kinds of derived-to-base conversions (C++ 2015/// [over.ics.rank]p4b3). As part of these checks, we also look at 2016/// conversions between Objective-C interface types. 2017ImplicitConversionSequence::CompareKind 2018Sema::CompareDerivedToBaseConversions(const StandardConversionSequence& SCS1, 2019 const StandardConversionSequence& SCS2) { 2020 QualType FromType1 = SCS1.getFromType(); 2021 QualType ToType1 = SCS1.getToType(1); 2022 QualType FromType2 = SCS2.getFromType(); 2023 QualType ToType2 = SCS2.getToType(1); 2024 2025 // Adjust the types we're converting from via the array-to-pointer 2026 // conversion, if we need to. 2027 if (SCS1.First == ICK_Array_To_Pointer) 2028 FromType1 = Context.getArrayDecayedType(FromType1); 2029 if (SCS2.First == ICK_Array_To_Pointer) 2030 FromType2 = Context.getArrayDecayedType(FromType2); 2031 2032 // Canonicalize all of the types. 2033 FromType1 = Context.getCanonicalType(FromType1); 2034 ToType1 = Context.getCanonicalType(ToType1); 2035 FromType2 = Context.getCanonicalType(FromType2); 2036 ToType2 = Context.getCanonicalType(ToType2); 2037 2038 // C++ [over.ics.rank]p4b3: 2039 // 2040 // If class B is derived directly or indirectly from class A and 2041 // class C is derived directly or indirectly from B, 2042 // 2043 // For Objective-C, we let A, B, and C also be Objective-C 2044 // interfaces. 2045 2046 // Compare based on pointer conversions. 2047 if (SCS1.Second == ICK_Pointer_Conversion && 2048 SCS2.Second == ICK_Pointer_Conversion && 2049 /*FIXME: Remove if Objective-C id conversions get their own rank*/ 2050 FromType1->isPointerType() && FromType2->isPointerType() && 2051 ToType1->isPointerType() && ToType2->isPointerType()) { 2052 QualType FromPointee1 2053 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2054 QualType ToPointee1 2055 = ToType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2056 QualType FromPointee2 2057 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2058 QualType ToPointee2 2059 = ToType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2060 2061 const ObjCInterfaceType* FromIface1 = FromPointee1->getAs<ObjCInterfaceType>(); 2062 const ObjCInterfaceType* FromIface2 = FromPointee2->getAs<ObjCInterfaceType>(); 2063 const ObjCInterfaceType* ToIface1 = ToPointee1->getAs<ObjCInterfaceType>(); 2064 const ObjCInterfaceType* ToIface2 = ToPointee2->getAs<ObjCInterfaceType>(); 2065 2066 // -- conversion of C* to B* is better than conversion of C* to A*, 2067 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 2068 if (IsDerivedFrom(ToPointee1, ToPointee2)) 2069 return ImplicitConversionSequence::Better; 2070 else if (IsDerivedFrom(ToPointee2, ToPointee1)) 2071 return ImplicitConversionSequence::Worse; 2072 2073 if (ToIface1 && ToIface2) { 2074 if (Context.canAssignObjCInterfaces(ToIface2, ToIface1)) 2075 return ImplicitConversionSequence::Better; 2076 else if (Context.canAssignObjCInterfaces(ToIface1, ToIface2)) 2077 return ImplicitConversionSequence::Worse; 2078 } 2079 } 2080 2081 // -- conversion of B* to A* is better than conversion of C* to A*, 2082 if (FromPointee1 != FromPointee2 && ToPointee1 == ToPointee2) { 2083 if (IsDerivedFrom(FromPointee2, FromPointee1)) 2084 return ImplicitConversionSequence::Better; 2085 else if (IsDerivedFrom(FromPointee1, FromPointee2)) 2086 return ImplicitConversionSequence::Worse; 2087 2088 if (FromIface1 && FromIface2) { 2089 if (Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 2090 return ImplicitConversionSequence::Better; 2091 else if (Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 2092 return ImplicitConversionSequence::Worse; 2093 } 2094 } 2095 } 2096 2097 // Ranking of member-pointer types. 2098 if (SCS1.Second == ICK_Pointer_Member && SCS2.Second == ICK_Pointer_Member && 2099 FromType1->isMemberPointerType() && FromType2->isMemberPointerType() && 2100 ToType1->isMemberPointerType() && ToType2->isMemberPointerType()) { 2101 const MemberPointerType * FromMemPointer1 = 2102 FromType1->getAs<MemberPointerType>(); 2103 const MemberPointerType * ToMemPointer1 = 2104 ToType1->getAs<MemberPointerType>(); 2105 const MemberPointerType * FromMemPointer2 = 2106 FromType2->getAs<MemberPointerType>(); 2107 const MemberPointerType * ToMemPointer2 = 2108 ToType2->getAs<MemberPointerType>(); 2109 const Type *FromPointeeType1 = FromMemPointer1->getClass(); 2110 const Type *ToPointeeType1 = ToMemPointer1->getClass(); 2111 const Type *FromPointeeType2 = FromMemPointer2->getClass(); 2112 const Type *ToPointeeType2 = ToMemPointer2->getClass(); 2113 QualType FromPointee1 = QualType(FromPointeeType1, 0).getUnqualifiedType(); 2114 QualType ToPointee1 = QualType(ToPointeeType1, 0).getUnqualifiedType(); 2115 QualType FromPointee2 = QualType(FromPointeeType2, 0).getUnqualifiedType(); 2116 QualType ToPointee2 = QualType(ToPointeeType2, 0).getUnqualifiedType(); 2117 // conversion of A::* to B::* is better than conversion of A::* to C::*, 2118 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 2119 if (IsDerivedFrom(ToPointee1, ToPointee2)) 2120 return ImplicitConversionSequence::Worse; 2121 else if (IsDerivedFrom(ToPointee2, ToPointee1)) 2122 return ImplicitConversionSequence::Better; 2123 } 2124 // conversion of B::* to C::* is better than conversion of A::* to C::* 2125 if (ToPointee1 == ToPointee2 && FromPointee1 != FromPointee2) { 2126 if (IsDerivedFrom(FromPointee1, FromPointee2)) 2127 return ImplicitConversionSequence::Better; 2128 else if (IsDerivedFrom(FromPointee2, FromPointee1)) 2129 return ImplicitConversionSequence::Worse; 2130 } 2131 } 2132 2133 if ((SCS1.ReferenceBinding || SCS1.CopyConstructor) && 2134 (SCS2.ReferenceBinding || SCS2.CopyConstructor) && 2135 SCS1.Second == ICK_Derived_To_Base) { 2136 // -- conversion of C to B is better than conversion of C to A, 2137 // -- binding of an expression of type C to a reference of type 2138 // B& is better than binding an expression of type C to a 2139 // reference of type A&, 2140 if (Context.hasSameUnqualifiedType(FromType1, FromType2) && 2141 !Context.hasSameUnqualifiedType(ToType1, ToType2)) { 2142 if (IsDerivedFrom(ToType1, ToType2)) 2143 return ImplicitConversionSequence::Better; 2144 else if (IsDerivedFrom(ToType2, ToType1)) 2145 return ImplicitConversionSequence::Worse; 2146 } 2147 2148 // -- conversion of B to A is better than conversion of C to A. 2149 // -- binding of an expression of type B to a reference of type 2150 // A& is better than binding an expression of type C to a 2151 // reference of type A&, 2152 if (!Context.hasSameUnqualifiedType(FromType1, FromType2) && 2153 Context.hasSameUnqualifiedType(ToType1, ToType2)) { 2154 if (IsDerivedFrom(FromType2, FromType1)) 2155 return ImplicitConversionSequence::Better; 2156 else if (IsDerivedFrom(FromType1, FromType2)) 2157 return ImplicitConversionSequence::Worse; 2158 } 2159 } 2160 2161 return ImplicitConversionSequence::Indistinguishable; 2162} 2163 2164/// TryCopyInitialization - Try to copy-initialize a value of type 2165/// ToType from the expression From. Return the implicit conversion 2166/// sequence required to pass this argument, which may be a bad 2167/// conversion sequence (meaning that the argument cannot be passed to 2168/// a parameter of this type). If @p SuppressUserConversions, then we 2169/// do not permit any user-defined conversion sequences. If @p ForceRValue, 2170/// then we treat @p From as an rvalue, even if it is an lvalue. 2171ImplicitConversionSequence 2172Sema::TryCopyInitialization(Expr *From, QualType ToType, 2173 bool SuppressUserConversions, bool ForceRValue, 2174 bool InOverloadResolution) { 2175 if (ToType->isReferenceType()) { 2176 ImplicitConversionSequence ICS; 2177 ICS.setBad(BadConversionSequence::no_conversion, From, ToType); 2178 CheckReferenceInit(From, ToType, 2179 /*FIXME:*/From->getLocStart(), 2180 SuppressUserConversions, 2181 /*AllowExplicit=*/false, 2182 ForceRValue, 2183 &ICS); 2184 return ICS; 2185 } else { 2186 return TryImplicitConversion(From, ToType, 2187 SuppressUserConversions, 2188 /*AllowExplicit=*/false, 2189 ForceRValue, 2190 InOverloadResolution); 2191 } 2192} 2193 2194/// PerformCopyInitialization - Copy-initialize an object of type @p ToType with 2195/// the expression @p From. Returns true (and emits a diagnostic) if there was 2196/// an error, returns false if the initialization succeeded. Elidable should 2197/// be true when the copy may be elided (C++ 12.8p15). Overload resolution works 2198/// differently in C++0x for this case. 2199bool Sema::PerformCopyInitialization(Expr *&From, QualType ToType, 2200 AssignmentAction Action, bool Elidable) { 2201 if (!getLangOptions().CPlusPlus) { 2202 // In C, argument passing is the same as performing an assignment. 2203 QualType FromType = From->getType(); 2204 2205 AssignConvertType ConvTy = 2206 CheckSingleAssignmentConstraints(ToType, From); 2207 if (ConvTy != Compatible && 2208 CheckTransparentUnionArgumentConstraints(ToType, From) == Compatible) 2209 ConvTy = Compatible; 2210 2211 return DiagnoseAssignmentResult(ConvTy, From->getLocStart(), ToType, 2212 FromType, From, Action); 2213 } 2214 2215 if (ToType->isReferenceType()) 2216 return CheckReferenceInit(From, ToType, 2217 /*FIXME:*/From->getLocStart(), 2218 /*SuppressUserConversions=*/false, 2219 /*AllowExplicit=*/false, 2220 /*ForceRValue=*/false); 2221 2222 if (!PerformImplicitConversion(From, ToType, Action, 2223 /*AllowExplicit=*/false, Elidable)) 2224 return false; 2225 if (!DiagnoseMultipleUserDefinedConversion(From, ToType)) 2226 return Diag(From->getSourceRange().getBegin(), 2227 diag::err_typecheck_convert_incompatible) 2228 << ToType << From->getType() << Action << From->getSourceRange(); 2229 return true; 2230} 2231 2232/// TryObjectArgumentInitialization - Try to initialize the object 2233/// parameter of the given member function (@c Method) from the 2234/// expression @p From. 2235ImplicitConversionSequence 2236Sema::TryObjectArgumentInitialization(QualType OrigFromType, 2237 CXXMethodDecl *Method, 2238 CXXRecordDecl *ActingContext) { 2239 QualType ClassType = Context.getTypeDeclType(ActingContext); 2240 // [class.dtor]p2: A destructor can be invoked for a const, volatile or 2241 // const volatile object. 2242 unsigned Quals = isa<CXXDestructorDecl>(Method) ? 2243 Qualifiers::Const | Qualifiers::Volatile : Method->getTypeQualifiers(); 2244 QualType ImplicitParamType = Context.getCVRQualifiedType(ClassType, Quals); 2245 2246 // Set up the conversion sequence as a "bad" conversion, to allow us 2247 // to exit early. 2248 ImplicitConversionSequence ICS; 2249 2250 // We need to have an object of class type. 2251 QualType FromType = OrigFromType; 2252 if (const PointerType *PT = FromType->getAs<PointerType>()) 2253 FromType = PT->getPointeeType(); 2254 2255 assert(FromType->isRecordType()); 2256 2257 // The implicit object parameter is has the type "reference to cv X", 2258 // where X is the class of which the function is a member 2259 // (C++ [over.match.funcs]p4). However, when finding an implicit 2260 // conversion sequence for the argument, we are not allowed to 2261 // create temporaries or perform user-defined conversions 2262 // (C++ [over.match.funcs]p5). We perform a simplified version of 2263 // reference binding here, that allows class rvalues to bind to 2264 // non-constant references. 2265 2266 // First check the qualifiers. We don't care about lvalue-vs-rvalue 2267 // with the implicit object parameter (C++ [over.match.funcs]p5). 2268 QualType FromTypeCanon = Context.getCanonicalType(FromType); 2269 if (ImplicitParamType.getCVRQualifiers() 2270 != FromTypeCanon.getLocalCVRQualifiers() && 2271 !ImplicitParamType.isAtLeastAsQualifiedAs(FromTypeCanon)) { 2272 ICS.setBad(BadConversionSequence::bad_qualifiers, 2273 OrigFromType, ImplicitParamType); 2274 return ICS; 2275 } 2276 2277 // Check that we have either the same type or a derived type. It 2278 // affects the conversion rank. 2279 QualType ClassTypeCanon = Context.getCanonicalType(ClassType); 2280 ImplicitConversionKind SecondKind; 2281 if (ClassTypeCanon == FromTypeCanon.getLocalUnqualifiedType()) { 2282 SecondKind = ICK_Identity; 2283 } else if (IsDerivedFrom(FromType, ClassType)) 2284 SecondKind = ICK_Derived_To_Base; 2285 else { 2286 ICS.setBad(BadConversionSequence::unrelated_class, 2287 FromType, ImplicitParamType); 2288 return ICS; 2289 } 2290 2291 // Success. Mark this as a reference binding. 2292 ICS.setStandard(); 2293 ICS.Standard.setAsIdentityConversion(); 2294 ICS.Standard.Second = SecondKind; 2295 ICS.Standard.setFromType(FromType); 2296 ICS.Standard.setAllToTypes(ImplicitParamType); 2297 ICS.Standard.ReferenceBinding = true; 2298 ICS.Standard.DirectBinding = true; 2299 ICS.Standard.RRefBinding = false; 2300 return ICS; 2301} 2302 2303/// PerformObjectArgumentInitialization - Perform initialization of 2304/// the implicit object parameter for the given Method with the given 2305/// expression. 2306bool 2307Sema::PerformObjectArgumentInitialization(Expr *&From, 2308 NestedNameSpecifier *Qualifier, 2309 CXXMethodDecl *Method) { 2310 QualType FromRecordType, DestType; 2311 QualType ImplicitParamRecordType = 2312 Method->getThisType(Context)->getAs<PointerType>()->getPointeeType(); 2313 2314 if (const PointerType *PT = From->getType()->getAs<PointerType>()) { 2315 FromRecordType = PT->getPointeeType(); 2316 DestType = Method->getThisType(Context); 2317 } else { 2318 FromRecordType = From->getType(); 2319 DestType = ImplicitParamRecordType; 2320 } 2321 2322 // Note that we always use the true parent context when performing 2323 // the actual argument initialization. 2324 ImplicitConversionSequence ICS 2325 = TryObjectArgumentInitialization(From->getType(), Method, 2326 Method->getParent()); 2327 if (ICS.isBad()) 2328 return Diag(From->getSourceRange().getBegin(), 2329 diag::err_implicit_object_parameter_init) 2330 << ImplicitParamRecordType << FromRecordType << From->getSourceRange(); 2331 2332 if (ICS.Standard.Second == ICK_Derived_To_Base) 2333 return PerformObjectMemberConversion(From, Qualifier, Method); 2334 2335 if (!Context.hasSameType(From->getType(), DestType)) 2336 ImpCastExprToType(From, DestType, CastExpr::CK_NoOp, 2337 /*isLvalue=*/!From->getType()->getAs<PointerType>()); 2338 return false; 2339} 2340 2341/// TryContextuallyConvertToBool - Attempt to contextually convert the 2342/// expression From to bool (C++0x [conv]p3). 2343ImplicitConversionSequence Sema::TryContextuallyConvertToBool(Expr *From) { 2344 return TryImplicitConversion(From, Context.BoolTy, 2345 // FIXME: Are these flags correct? 2346 /*SuppressUserConversions=*/false, 2347 /*AllowExplicit=*/true, 2348 /*ForceRValue=*/false, 2349 /*InOverloadResolution=*/false); 2350} 2351 2352/// PerformContextuallyConvertToBool - Perform a contextual conversion 2353/// of the expression From to bool (C++0x [conv]p3). 2354bool Sema::PerformContextuallyConvertToBool(Expr *&From) { 2355 ImplicitConversionSequence ICS = TryContextuallyConvertToBool(From); 2356 if (!ICS.isBad()) 2357 return PerformImplicitConversion(From, Context.BoolTy, ICS, AA_Converting); 2358 2359 if (!DiagnoseMultipleUserDefinedConversion(From, Context.BoolTy)) 2360 return Diag(From->getSourceRange().getBegin(), 2361 diag::err_typecheck_bool_condition) 2362 << From->getType() << From->getSourceRange(); 2363 return true; 2364} 2365 2366/// AddOverloadCandidate - Adds the given function to the set of 2367/// candidate functions, using the given function call arguments. If 2368/// @p SuppressUserConversions, then don't allow user-defined 2369/// conversions via constructors or conversion operators. 2370/// If @p ForceRValue, treat all arguments as rvalues. This is a slightly 2371/// hacky way to implement the overloading rules for elidable copy 2372/// initialization in C++0x (C++0x 12.8p15). 2373/// 2374/// \para PartialOverloading true if we are performing "partial" overloading 2375/// based on an incomplete set of function arguments. This feature is used by 2376/// code completion. 2377void 2378Sema::AddOverloadCandidate(FunctionDecl *Function, 2379 AccessSpecifier Access, 2380 Expr **Args, unsigned NumArgs, 2381 OverloadCandidateSet& CandidateSet, 2382 bool SuppressUserConversions, 2383 bool ForceRValue, 2384 bool PartialOverloading) { 2385 const FunctionProtoType* Proto 2386 = dyn_cast<FunctionProtoType>(Function->getType()->getAs<FunctionType>()); 2387 assert(Proto && "Functions without a prototype cannot be overloaded"); 2388 assert(!Function->getDescribedFunctionTemplate() && 2389 "Use AddTemplateOverloadCandidate for function templates"); 2390 2391 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Function)) { 2392 if (!isa<CXXConstructorDecl>(Method)) { 2393 // If we get here, it's because we're calling a member function 2394 // that is named without a member access expression (e.g., 2395 // "this->f") that was either written explicitly or created 2396 // implicitly. This can happen with a qualified call to a member 2397 // function, e.g., X::f(). We use an empty type for the implied 2398 // object argument (C++ [over.call.func]p3), and the acting context 2399 // is irrelevant. 2400 AddMethodCandidate(Method, Access, Method->getParent(), 2401 QualType(), Args, NumArgs, CandidateSet, 2402 SuppressUserConversions, ForceRValue); 2403 return; 2404 } 2405 // We treat a constructor like a non-member function, since its object 2406 // argument doesn't participate in overload resolution. 2407 } 2408 2409 if (!CandidateSet.isNewCandidate(Function)) 2410 return; 2411 2412 // Overload resolution is always an unevaluated context. 2413 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 2414 2415 if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(Function)){ 2416 // C++ [class.copy]p3: 2417 // A member function template is never instantiated to perform the copy 2418 // of a class object to an object of its class type. 2419 QualType ClassType = Context.getTypeDeclType(Constructor->getParent()); 2420 if (NumArgs == 1 && 2421 Constructor->isCopyConstructorLikeSpecialization() && 2422 (Context.hasSameUnqualifiedType(ClassType, Args[0]->getType()) || 2423 IsDerivedFrom(Args[0]->getType(), ClassType))) 2424 return; 2425 } 2426 2427 // Add this candidate 2428 CandidateSet.push_back(OverloadCandidate()); 2429 OverloadCandidate& Candidate = CandidateSet.back(); 2430 Candidate.Function = Function; 2431 Candidate.Access = Access; 2432 Candidate.Viable = true; 2433 Candidate.IsSurrogate = false; 2434 Candidate.IgnoreObjectArgument = false; 2435 2436 unsigned NumArgsInProto = Proto->getNumArgs(); 2437 2438 // (C++ 13.3.2p2): A candidate function having fewer than m 2439 // parameters is viable only if it has an ellipsis in its parameter 2440 // list (8.3.5). 2441 if ((NumArgs + (PartialOverloading && NumArgs)) > NumArgsInProto && 2442 !Proto->isVariadic()) { 2443 Candidate.Viable = false; 2444 Candidate.FailureKind = ovl_fail_too_many_arguments; 2445 return; 2446 } 2447 2448 // (C++ 13.3.2p2): A candidate function having more than m parameters 2449 // is viable only if the (m+1)st parameter has a default argument 2450 // (8.3.6). For the purposes of overload resolution, the 2451 // parameter list is truncated on the right, so that there are 2452 // exactly m parameters. 2453 unsigned MinRequiredArgs = Function->getMinRequiredArguments(); 2454 if (NumArgs < MinRequiredArgs && !PartialOverloading) { 2455 // Not enough arguments. 2456 Candidate.Viable = false; 2457 Candidate.FailureKind = ovl_fail_too_few_arguments; 2458 return; 2459 } 2460 2461 // Determine the implicit conversion sequences for each of the 2462 // arguments. 2463 Candidate.Conversions.resize(NumArgs); 2464 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2465 if (ArgIdx < NumArgsInProto) { 2466 // (C++ 13.3.2p3): for F to be a viable function, there shall 2467 // exist for each argument an implicit conversion sequence 2468 // (13.3.3.1) that converts that argument to the corresponding 2469 // parameter of F. 2470 QualType ParamType = Proto->getArgType(ArgIdx); 2471 Candidate.Conversions[ArgIdx] 2472 = TryCopyInitialization(Args[ArgIdx], ParamType, 2473 SuppressUserConversions, ForceRValue, 2474 /*InOverloadResolution=*/true); 2475 if (Candidate.Conversions[ArgIdx].isBad()) { 2476 Candidate.Viable = false; 2477 Candidate.FailureKind = ovl_fail_bad_conversion; 2478 break; 2479 } 2480 } else { 2481 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2482 // argument for which there is no corresponding parameter is 2483 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2484 Candidate.Conversions[ArgIdx].setEllipsis(); 2485 } 2486 } 2487} 2488 2489/// \brief Add all of the function declarations in the given function set to 2490/// the overload canddiate set. 2491void Sema::AddFunctionCandidates(const UnresolvedSetImpl &Fns, 2492 Expr **Args, unsigned NumArgs, 2493 OverloadCandidateSet& CandidateSet, 2494 bool SuppressUserConversions) { 2495 for (UnresolvedSetIterator F = Fns.begin(), E = Fns.end(); F != E; ++F) { 2496 // FIXME: using declarations 2497 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*F)) { 2498 if (isa<CXXMethodDecl>(FD) && !cast<CXXMethodDecl>(FD)->isStatic()) 2499 AddMethodCandidate(cast<CXXMethodDecl>(FD), F.getAccess(), 2500 cast<CXXMethodDecl>(FD)->getParent(), 2501 Args[0]->getType(), Args + 1, NumArgs - 1, 2502 CandidateSet, SuppressUserConversions); 2503 else 2504 AddOverloadCandidate(FD, AS_none, Args, NumArgs, CandidateSet, 2505 SuppressUserConversions); 2506 } else { 2507 FunctionTemplateDecl *FunTmpl = cast<FunctionTemplateDecl>(*F); 2508 if (isa<CXXMethodDecl>(FunTmpl->getTemplatedDecl()) && 2509 !cast<CXXMethodDecl>(FunTmpl->getTemplatedDecl())->isStatic()) 2510 AddMethodTemplateCandidate(FunTmpl, F.getAccess(), 2511 cast<CXXRecordDecl>(FunTmpl->getDeclContext()), 2512 /*FIXME: explicit args */ 0, 2513 Args[0]->getType(), Args + 1, NumArgs - 1, 2514 CandidateSet, 2515 SuppressUserConversions); 2516 else 2517 AddTemplateOverloadCandidate(FunTmpl, AS_none, 2518 /*FIXME: explicit args */ 0, 2519 Args, NumArgs, CandidateSet, 2520 SuppressUserConversions); 2521 } 2522 } 2523} 2524 2525/// AddMethodCandidate - Adds a named decl (which is some kind of 2526/// method) as a method candidate to the given overload set. 2527void Sema::AddMethodCandidate(NamedDecl *Decl, 2528 AccessSpecifier Access, 2529 QualType ObjectType, 2530 Expr **Args, unsigned NumArgs, 2531 OverloadCandidateSet& CandidateSet, 2532 bool SuppressUserConversions, bool ForceRValue) { 2533 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(Decl->getDeclContext()); 2534 2535 if (isa<UsingShadowDecl>(Decl)) 2536 Decl = cast<UsingShadowDecl>(Decl)->getTargetDecl(); 2537 2538 if (FunctionTemplateDecl *TD = dyn_cast<FunctionTemplateDecl>(Decl)) { 2539 assert(isa<CXXMethodDecl>(TD->getTemplatedDecl()) && 2540 "Expected a member function template"); 2541 AddMethodTemplateCandidate(TD, Access, ActingContext, /*ExplicitArgs*/ 0, 2542 ObjectType, Args, NumArgs, 2543 CandidateSet, 2544 SuppressUserConversions, 2545 ForceRValue); 2546 } else { 2547 AddMethodCandidate(cast<CXXMethodDecl>(Decl), Access, ActingContext, 2548 ObjectType, Args, NumArgs, 2549 CandidateSet, SuppressUserConversions, ForceRValue); 2550 } 2551} 2552 2553/// AddMethodCandidate - Adds the given C++ member function to the set 2554/// of candidate functions, using the given function call arguments 2555/// and the object argument (@c Object). For example, in a call 2556/// @c o.f(a1,a2), @c Object will contain @c o and @c Args will contain 2557/// both @c a1 and @c a2. If @p SuppressUserConversions, then don't 2558/// allow user-defined conversions via constructors or conversion 2559/// operators. If @p ForceRValue, treat all arguments as rvalues. This is 2560/// a slightly hacky way to implement the overloading rules for elidable copy 2561/// initialization in C++0x (C++0x 12.8p15). 2562void 2563Sema::AddMethodCandidate(CXXMethodDecl *Method, AccessSpecifier Access, 2564 CXXRecordDecl *ActingContext, QualType ObjectType, 2565 Expr **Args, unsigned NumArgs, 2566 OverloadCandidateSet& CandidateSet, 2567 bool SuppressUserConversions, bool ForceRValue) { 2568 const FunctionProtoType* Proto 2569 = dyn_cast<FunctionProtoType>(Method->getType()->getAs<FunctionType>()); 2570 assert(Proto && "Methods without a prototype cannot be overloaded"); 2571 assert(!isa<CXXConstructorDecl>(Method) && 2572 "Use AddOverloadCandidate for constructors"); 2573 2574 if (!CandidateSet.isNewCandidate(Method)) 2575 return; 2576 2577 // Overload resolution is always an unevaluated context. 2578 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 2579 2580 // Add this candidate 2581 CandidateSet.push_back(OverloadCandidate()); 2582 OverloadCandidate& Candidate = CandidateSet.back(); 2583 Candidate.Function = Method; 2584 Candidate.Access = Access; 2585 Candidate.IsSurrogate = false; 2586 Candidate.IgnoreObjectArgument = false; 2587 2588 unsigned NumArgsInProto = Proto->getNumArgs(); 2589 2590 // (C++ 13.3.2p2): A candidate function having fewer than m 2591 // parameters is viable only if it has an ellipsis in its parameter 2592 // list (8.3.5). 2593 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 2594 Candidate.Viable = false; 2595 Candidate.FailureKind = ovl_fail_too_many_arguments; 2596 return; 2597 } 2598 2599 // (C++ 13.3.2p2): A candidate function having more than m parameters 2600 // is viable only if the (m+1)st parameter has a default argument 2601 // (8.3.6). For the purposes of overload resolution, the 2602 // parameter list is truncated on the right, so that there are 2603 // exactly m parameters. 2604 unsigned MinRequiredArgs = Method->getMinRequiredArguments(); 2605 if (NumArgs < MinRequiredArgs) { 2606 // Not enough arguments. 2607 Candidate.Viable = false; 2608 Candidate.FailureKind = ovl_fail_too_few_arguments; 2609 return; 2610 } 2611 2612 Candidate.Viable = true; 2613 Candidate.Conversions.resize(NumArgs + 1); 2614 2615 if (Method->isStatic() || ObjectType.isNull()) 2616 // The implicit object argument is ignored. 2617 Candidate.IgnoreObjectArgument = true; 2618 else { 2619 // Determine the implicit conversion sequence for the object 2620 // parameter. 2621 Candidate.Conversions[0] 2622 = TryObjectArgumentInitialization(ObjectType, Method, ActingContext); 2623 if (Candidate.Conversions[0].isBad()) { 2624 Candidate.Viable = false; 2625 Candidate.FailureKind = ovl_fail_bad_conversion; 2626 return; 2627 } 2628 } 2629 2630 // Determine the implicit conversion sequences for each of the 2631 // arguments. 2632 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2633 if (ArgIdx < NumArgsInProto) { 2634 // (C++ 13.3.2p3): for F to be a viable function, there shall 2635 // exist for each argument an implicit conversion sequence 2636 // (13.3.3.1) that converts that argument to the corresponding 2637 // parameter of F. 2638 QualType ParamType = Proto->getArgType(ArgIdx); 2639 Candidate.Conversions[ArgIdx + 1] 2640 = TryCopyInitialization(Args[ArgIdx], ParamType, 2641 SuppressUserConversions, ForceRValue, 2642 /*InOverloadResolution=*/true); 2643 if (Candidate.Conversions[ArgIdx + 1].isBad()) { 2644 Candidate.Viable = false; 2645 Candidate.FailureKind = ovl_fail_bad_conversion; 2646 break; 2647 } 2648 } else { 2649 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2650 // argument for which there is no corresponding parameter is 2651 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2652 Candidate.Conversions[ArgIdx + 1].setEllipsis(); 2653 } 2654 } 2655} 2656 2657/// \brief Add a C++ member function template as a candidate to the candidate 2658/// set, using template argument deduction to produce an appropriate member 2659/// function template specialization. 2660void 2661Sema::AddMethodTemplateCandidate(FunctionTemplateDecl *MethodTmpl, 2662 AccessSpecifier Access, 2663 CXXRecordDecl *ActingContext, 2664 const TemplateArgumentListInfo *ExplicitTemplateArgs, 2665 QualType ObjectType, 2666 Expr **Args, unsigned NumArgs, 2667 OverloadCandidateSet& CandidateSet, 2668 bool SuppressUserConversions, 2669 bool ForceRValue) { 2670 if (!CandidateSet.isNewCandidate(MethodTmpl)) 2671 return; 2672 2673 // C++ [over.match.funcs]p7: 2674 // In each case where a candidate is a function template, candidate 2675 // function template specializations are generated using template argument 2676 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 2677 // candidate functions in the usual way.113) A given name can refer to one 2678 // or more function templates and also to a set of overloaded non-template 2679 // functions. In such a case, the candidate functions generated from each 2680 // function template are combined with the set of non-template candidate 2681 // functions. 2682 TemplateDeductionInfo Info(Context, CandidateSet.getLocation()); 2683 FunctionDecl *Specialization = 0; 2684 if (TemplateDeductionResult Result 2685 = DeduceTemplateArguments(MethodTmpl, ExplicitTemplateArgs, 2686 Args, NumArgs, Specialization, Info)) { 2687 // FIXME: Record what happened with template argument deduction, so 2688 // that we can give the user a beautiful diagnostic. 2689 (void)Result; 2690 return; 2691 } 2692 2693 // Add the function template specialization produced by template argument 2694 // deduction as a candidate. 2695 assert(Specialization && "Missing member function template specialization?"); 2696 assert(isa<CXXMethodDecl>(Specialization) && 2697 "Specialization is not a member function?"); 2698 AddMethodCandidate(cast<CXXMethodDecl>(Specialization), Access, 2699 ActingContext, ObjectType, Args, NumArgs, 2700 CandidateSet, SuppressUserConversions, ForceRValue); 2701} 2702 2703/// \brief Add a C++ function template specialization as a candidate 2704/// in the candidate set, using template argument deduction to produce 2705/// an appropriate function template specialization. 2706void 2707Sema::AddTemplateOverloadCandidate(FunctionTemplateDecl *FunctionTemplate, 2708 AccessSpecifier Access, 2709 const TemplateArgumentListInfo *ExplicitTemplateArgs, 2710 Expr **Args, unsigned NumArgs, 2711 OverloadCandidateSet& CandidateSet, 2712 bool SuppressUserConversions, 2713 bool ForceRValue) { 2714 if (!CandidateSet.isNewCandidate(FunctionTemplate)) 2715 return; 2716 2717 // C++ [over.match.funcs]p7: 2718 // In each case where a candidate is a function template, candidate 2719 // function template specializations are generated using template argument 2720 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 2721 // candidate functions in the usual way.113) A given name can refer to one 2722 // or more function templates and also to a set of overloaded non-template 2723 // functions. In such a case, the candidate functions generated from each 2724 // function template are combined with the set of non-template candidate 2725 // functions. 2726 TemplateDeductionInfo Info(Context, CandidateSet.getLocation()); 2727 FunctionDecl *Specialization = 0; 2728 if (TemplateDeductionResult Result 2729 = DeduceTemplateArguments(FunctionTemplate, ExplicitTemplateArgs, 2730 Args, NumArgs, Specialization, Info)) { 2731 CandidateSet.push_back(OverloadCandidate()); 2732 OverloadCandidate &Candidate = CandidateSet.back(); 2733 Candidate.Function = FunctionTemplate->getTemplatedDecl(); 2734 Candidate.Access = Access; 2735 Candidate.Viable = false; 2736 Candidate.FailureKind = ovl_fail_bad_deduction; 2737 Candidate.IsSurrogate = false; 2738 Candidate.IgnoreObjectArgument = false; 2739 2740 // TODO: record more information about failed template arguments 2741 Candidate.DeductionFailure.Result = Result; 2742 Candidate.DeductionFailure.TemplateParameter = Info.Param.getOpaqueValue(); 2743 return; 2744 } 2745 2746 // Add the function template specialization produced by template argument 2747 // deduction as a candidate. 2748 assert(Specialization && "Missing function template specialization?"); 2749 AddOverloadCandidate(Specialization, Access, Args, NumArgs, CandidateSet, 2750 SuppressUserConversions, ForceRValue); 2751} 2752 2753/// AddConversionCandidate - Add a C++ conversion function as a 2754/// candidate in the candidate set (C++ [over.match.conv], 2755/// C++ [over.match.copy]). From is the expression we're converting from, 2756/// and ToType is the type that we're eventually trying to convert to 2757/// (which may or may not be the same type as the type that the 2758/// conversion function produces). 2759void 2760Sema::AddConversionCandidate(CXXConversionDecl *Conversion, 2761 AccessSpecifier Access, 2762 CXXRecordDecl *ActingContext, 2763 Expr *From, QualType ToType, 2764 OverloadCandidateSet& CandidateSet) { 2765 assert(!Conversion->getDescribedFunctionTemplate() && 2766 "Conversion function templates use AddTemplateConversionCandidate"); 2767 2768 if (!CandidateSet.isNewCandidate(Conversion)) 2769 return; 2770 2771 // Overload resolution is always an unevaluated context. 2772 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 2773 2774 // Add this candidate 2775 CandidateSet.push_back(OverloadCandidate()); 2776 OverloadCandidate& Candidate = CandidateSet.back(); 2777 Candidate.Function = Conversion; 2778 Candidate.Access = Access; 2779 Candidate.IsSurrogate = false; 2780 Candidate.IgnoreObjectArgument = false; 2781 Candidate.FinalConversion.setAsIdentityConversion(); 2782 Candidate.FinalConversion.setFromType(Conversion->getConversionType()); 2783 Candidate.FinalConversion.setAllToTypes(ToType); 2784 2785 // Determine the implicit conversion sequence for the implicit 2786 // object parameter. 2787 Candidate.Viable = true; 2788 Candidate.Conversions.resize(1); 2789 Candidate.Conversions[0] 2790 = TryObjectArgumentInitialization(From->getType(), Conversion, 2791 ActingContext); 2792 // Conversion functions to a different type in the base class is visible in 2793 // the derived class. So, a derived to base conversion should not participate 2794 // in overload resolution. 2795 if (Candidate.Conversions[0].Standard.Second == ICK_Derived_To_Base) 2796 Candidate.Conversions[0].Standard.Second = ICK_Identity; 2797 if (Candidate.Conversions[0].isBad()) { 2798 Candidate.Viable = false; 2799 Candidate.FailureKind = ovl_fail_bad_conversion; 2800 return; 2801 } 2802 2803 // We won't go through a user-define type conversion function to convert a 2804 // derived to base as such conversions are given Conversion Rank. They only 2805 // go through a copy constructor. 13.3.3.1.2-p4 [over.ics.user] 2806 QualType FromCanon 2807 = Context.getCanonicalType(From->getType().getUnqualifiedType()); 2808 QualType ToCanon = Context.getCanonicalType(ToType).getUnqualifiedType(); 2809 if (FromCanon == ToCanon || IsDerivedFrom(FromCanon, ToCanon)) { 2810 Candidate.Viable = false; 2811 Candidate.FailureKind = ovl_fail_trivial_conversion; 2812 return; 2813 } 2814 2815 2816 // To determine what the conversion from the result of calling the 2817 // conversion function to the type we're eventually trying to 2818 // convert to (ToType), we need to synthesize a call to the 2819 // conversion function and attempt copy initialization from it. This 2820 // makes sure that we get the right semantics with respect to 2821 // lvalues/rvalues and the type. Fortunately, we can allocate this 2822 // call on the stack and we don't need its arguments to be 2823 // well-formed. 2824 DeclRefExpr ConversionRef(Conversion, Conversion->getType(), 2825 From->getLocStart()); 2826 ImplicitCastExpr ConversionFn(Context.getPointerType(Conversion->getType()), 2827 CastExpr::CK_FunctionToPointerDecay, 2828 &ConversionRef, false); 2829 2830 // Note that it is safe to allocate CallExpr on the stack here because 2831 // there are 0 arguments (i.e., nothing is allocated using ASTContext's 2832 // allocator). 2833 CallExpr Call(Context, &ConversionFn, 0, 0, 2834 Conversion->getConversionType().getNonReferenceType(), 2835 From->getLocStart()); 2836 ImplicitConversionSequence ICS = 2837 TryCopyInitialization(&Call, ToType, 2838 /*SuppressUserConversions=*/true, 2839 /*ForceRValue=*/false, 2840 /*InOverloadResolution=*/false); 2841 2842 switch (ICS.getKind()) { 2843 case ImplicitConversionSequence::StandardConversion: 2844 Candidate.FinalConversion = ICS.Standard; 2845 break; 2846 2847 case ImplicitConversionSequence::BadConversion: 2848 Candidate.Viable = false; 2849 Candidate.FailureKind = ovl_fail_bad_final_conversion; 2850 break; 2851 2852 default: 2853 assert(false && 2854 "Can only end up with a standard conversion sequence or failure"); 2855 } 2856} 2857 2858/// \brief Adds a conversion function template specialization 2859/// candidate to the overload set, using template argument deduction 2860/// to deduce the template arguments of the conversion function 2861/// template from the type that we are converting to (C++ 2862/// [temp.deduct.conv]). 2863void 2864Sema::AddTemplateConversionCandidate(FunctionTemplateDecl *FunctionTemplate, 2865 AccessSpecifier Access, 2866 CXXRecordDecl *ActingDC, 2867 Expr *From, QualType ToType, 2868 OverloadCandidateSet &CandidateSet) { 2869 assert(isa<CXXConversionDecl>(FunctionTemplate->getTemplatedDecl()) && 2870 "Only conversion function templates permitted here"); 2871 2872 if (!CandidateSet.isNewCandidate(FunctionTemplate)) 2873 return; 2874 2875 TemplateDeductionInfo Info(Context, CandidateSet.getLocation()); 2876 CXXConversionDecl *Specialization = 0; 2877 if (TemplateDeductionResult Result 2878 = DeduceTemplateArguments(FunctionTemplate, ToType, 2879 Specialization, Info)) { 2880 // FIXME: Record what happened with template argument deduction, so 2881 // that we can give the user a beautiful diagnostic. 2882 (void)Result; 2883 return; 2884 } 2885 2886 // Add the conversion function template specialization produced by 2887 // template argument deduction as a candidate. 2888 assert(Specialization && "Missing function template specialization?"); 2889 AddConversionCandidate(Specialization, Access, ActingDC, From, ToType, 2890 CandidateSet); 2891} 2892 2893/// AddSurrogateCandidate - Adds a "surrogate" candidate function that 2894/// converts the given @c Object to a function pointer via the 2895/// conversion function @c Conversion, and then attempts to call it 2896/// with the given arguments (C++ [over.call.object]p2-4). Proto is 2897/// the type of function that we'll eventually be calling. 2898void Sema::AddSurrogateCandidate(CXXConversionDecl *Conversion, 2899 AccessSpecifier Access, 2900 CXXRecordDecl *ActingContext, 2901 const FunctionProtoType *Proto, 2902 QualType ObjectType, 2903 Expr **Args, unsigned NumArgs, 2904 OverloadCandidateSet& CandidateSet) { 2905 if (!CandidateSet.isNewCandidate(Conversion)) 2906 return; 2907 2908 // Overload resolution is always an unevaluated context. 2909 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 2910 2911 CandidateSet.push_back(OverloadCandidate()); 2912 OverloadCandidate& Candidate = CandidateSet.back(); 2913 Candidate.Function = 0; 2914 Candidate.Access = Access; 2915 Candidate.Surrogate = Conversion; 2916 Candidate.Viable = true; 2917 Candidate.IsSurrogate = true; 2918 Candidate.IgnoreObjectArgument = false; 2919 Candidate.Conversions.resize(NumArgs + 1); 2920 2921 // Determine the implicit conversion sequence for the implicit 2922 // object parameter. 2923 ImplicitConversionSequence ObjectInit 2924 = TryObjectArgumentInitialization(ObjectType, Conversion, ActingContext); 2925 if (ObjectInit.isBad()) { 2926 Candidate.Viable = false; 2927 Candidate.FailureKind = ovl_fail_bad_conversion; 2928 Candidate.Conversions[0] = ObjectInit; 2929 return; 2930 } 2931 2932 // The first conversion is actually a user-defined conversion whose 2933 // first conversion is ObjectInit's standard conversion (which is 2934 // effectively a reference binding). Record it as such. 2935 Candidate.Conversions[0].setUserDefined(); 2936 Candidate.Conversions[0].UserDefined.Before = ObjectInit.Standard; 2937 Candidate.Conversions[0].UserDefined.EllipsisConversion = false; 2938 Candidate.Conversions[0].UserDefined.ConversionFunction = Conversion; 2939 Candidate.Conversions[0].UserDefined.After 2940 = Candidate.Conversions[0].UserDefined.Before; 2941 Candidate.Conversions[0].UserDefined.After.setAsIdentityConversion(); 2942 2943 // Find the 2944 unsigned NumArgsInProto = Proto->getNumArgs(); 2945 2946 // (C++ 13.3.2p2): A candidate function having fewer than m 2947 // parameters is viable only if it has an ellipsis in its parameter 2948 // list (8.3.5). 2949 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 2950 Candidate.Viable = false; 2951 Candidate.FailureKind = ovl_fail_too_many_arguments; 2952 return; 2953 } 2954 2955 // Function types don't have any default arguments, so just check if 2956 // we have enough arguments. 2957 if (NumArgs < NumArgsInProto) { 2958 // Not enough arguments. 2959 Candidate.Viable = false; 2960 Candidate.FailureKind = ovl_fail_too_few_arguments; 2961 return; 2962 } 2963 2964 // Determine the implicit conversion sequences for each of the 2965 // arguments. 2966 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2967 if (ArgIdx < NumArgsInProto) { 2968 // (C++ 13.3.2p3): for F to be a viable function, there shall 2969 // exist for each argument an implicit conversion sequence 2970 // (13.3.3.1) that converts that argument to the corresponding 2971 // parameter of F. 2972 QualType ParamType = Proto->getArgType(ArgIdx); 2973 Candidate.Conversions[ArgIdx + 1] 2974 = TryCopyInitialization(Args[ArgIdx], ParamType, 2975 /*SuppressUserConversions=*/false, 2976 /*ForceRValue=*/false, 2977 /*InOverloadResolution=*/false); 2978 if (Candidate.Conversions[ArgIdx + 1].isBad()) { 2979 Candidate.Viable = false; 2980 Candidate.FailureKind = ovl_fail_bad_conversion; 2981 break; 2982 } 2983 } else { 2984 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2985 // argument for which there is no corresponding parameter is 2986 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2987 Candidate.Conversions[ArgIdx + 1].setEllipsis(); 2988 } 2989 } 2990} 2991 2992// FIXME: This will eventually be removed, once we've migrated all of the 2993// operator overloading logic over to the scheme used by binary operators, which 2994// works for template instantiation. 2995void Sema::AddOperatorCandidates(OverloadedOperatorKind Op, Scope *S, 2996 SourceLocation OpLoc, 2997 Expr **Args, unsigned NumArgs, 2998 OverloadCandidateSet& CandidateSet, 2999 SourceRange OpRange) { 3000 UnresolvedSet<16> Fns; 3001 3002 QualType T1 = Args[0]->getType(); 3003 QualType T2; 3004 if (NumArgs > 1) 3005 T2 = Args[1]->getType(); 3006 3007 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 3008 if (S) 3009 LookupOverloadedOperatorName(Op, S, T1, T2, Fns); 3010 AddFunctionCandidates(Fns, Args, NumArgs, CandidateSet, false); 3011 AddArgumentDependentLookupCandidates(OpName, false, Args, NumArgs, 0, 3012 CandidateSet); 3013 AddMemberOperatorCandidates(Op, OpLoc, Args, NumArgs, CandidateSet, OpRange); 3014 AddBuiltinOperatorCandidates(Op, OpLoc, Args, NumArgs, CandidateSet); 3015} 3016 3017/// \brief Add overload candidates for overloaded operators that are 3018/// member functions. 3019/// 3020/// Add the overloaded operator candidates that are member functions 3021/// for the operator Op that was used in an operator expression such 3022/// as "x Op y". , Args/NumArgs provides the operator arguments, and 3023/// CandidateSet will store the added overload candidates. (C++ 3024/// [over.match.oper]). 3025void Sema::AddMemberOperatorCandidates(OverloadedOperatorKind Op, 3026 SourceLocation OpLoc, 3027 Expr **Args, unsigned NumArgs, 3028 OverloadCandidateSet& CandidateSet, 3029 SourceRange OpRange) { 3030 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 3031 3032 // C++ [over.match.oper]p3: 3033 // For a unary operator @ with an operand of a type whose 3034 // cv-unqualified version is T1, and for a binary operator @ with 3035 // a left operand of a type whose cv-unqualified version is T1 and 3036 // a right operand of a type whose cv-unqualified version is T2, 3037 // three sets of candidate functions, designated member 3038 // candidates, non-member candidates and built-in candidates, are 3039 // constructed as follows: 3040 QualType T1 = Args[0]->getType(); 3041 QualType T2; 3042 if (NumArgs > 1) 3043 T2 = Args[1]->getType(); 3044 3045 // -- If T1 is a class type, the set of member candidates is the 3046 // result of the qualified lookup of T1::operator@ 3047 // (13.3.1.1.1); otherwise, the set of member candidates is 3048 // empty. 3049 if (const RecordType *T1Rec = T1->getAs<RecordType>()) { 3050 // Complete the type if it can be completed. Otherwise, we're done. 3051 if (RequireCompleteType(OpLoc, T1, PDiag())) 3052 return; 3053 3054 LookupResult Operators(*this, OpName, OpLoc, LookupOrdinaryName); 3055 LookupQualifiedName(Operators, T1Rec->getDecl()); 3056 Operators.suppressDiagnostics(); 3057 3058 for (LookupResult::iterator Oper = Operators.begin(), 3059 OperEnd = Operators.end(); 3060 Oper != OperEnd; 3061 ++Oper) 3062 AddMethodCandidate(*Oper, Oper.getAccess(), Args[0]->getType(), 3063 Args + 1, NumArgs - 1, CandidateSet, 3064 /* SuppressUserConversions = */ false); 3065 } 3066} 3067 3068/// AddBuiltinCandidate - Add a candidate for a built-in 3069/// operator. ResultTy and ParamTys are the result and parameter types 3070/// of the built-in candidate, respectively. Args and NumArgs are the 3071/// arguments being passed to the candidate. IsAssignmentOperator 3072/// should be true when this built-in candidate is an assignment 3073/// operator. NumContextualBoolArguments is the number of arguments 3074/// (at the beginning of the argument list) that will be contextually 3075/// converted to bool. 3076void Sema::AddBuiltinCandidate(QualType ResultTy, QualType *ParamTys, 3077 Expr **Args, unsigned NumArgs, 3078 OverloadCandidateSet& CandidateSet, 3079 bool IsAssignmentOperator, 3080 unsigned NumContextualBoolArguments) { 3081 // Overload resolution is always an unevaluated context. 3082 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 3083 3084 // Add this candidate 3085 CandidateSet.push_back(OverloadCandidate()); 3086 OverloadCandidate& Candidate = CandidateSet.back(); 3087 Candidate.Function = 0; 3088 Candidate.Access = AS_none; 3089 Candidate.IsSurrogate = false; 3090 Candidate.IgnoreObjectArgument = false; 3091 Candidate.BuiltinTypes.ResultTy = ResultTy; 3092 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 3093 Candidate.BuiltinTypes.ParamTypes[ArgIdx] = ParamTys[ArgIdx]; 3094 3095 // Determine the implicit conversion sequences for each of the 3096 // arguments. 3097 Candidate.Viable = true; 3098 Candidate.Conversions.resize(NumArgs); 3099 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 3100 // C++ [over.match.oper]p4: 3101 // For the built-in assignment operators, conversions of the 3102 // left operand are restricted as follows: 3103 // -- no temporaries are introduced to hold the left operand, and 3104 // -- no user-defined conversions are applied to the left 3105 // operand to achieve a type match with the left-most 3106 // parameter of a built-in candidate. 3107 // 3108 // We block these conversions by turning off user-defined 3109 // conversions, since that is the only way that initialization of 3110 // a reference to a non-class type can occur from something that 3111 // is not of the same type. 3112 if (ArgIdx < NumContextualBoolArguments) { 3113 assert(ParamTys[ArgIdx] == Context.BoolTy && 3114 "Contextual conversion to bool requires bool type"); 3115 Candidate.Conversions[ArgIdx] = TryContextuallyConvertToBool(Args[ArgIdx]); 3116 } else { 3117 Candidate.Conversions[ArgIdx] 3118 = TryCopyInitialization(Args[ArgIdx], ParamTys[ArgIdx], 3119 ArgIdx == 0 && IsAssignmentOperator, 3120 /*ForceRValue=*/false, 3121 /*InOverloadResolution=*/false); 3122 } 3123 if (Candidate.Conversions[ArgIdx].isBad()) { 3124 Candidate.Viable = false; 3125 Candidate.FailureKind = ovl_fail_bad_conversion; 3126 break; 3127 } 3128 } 3129} 3130 3131/// BuiltinCandidateTypeSet - A set of types that will be used for the 3132/// candidate operator functions for built-in operators (C++ 3133/// [over.built]). The types are separated into pointer types and 3134/// enumeration types. 3135class BuiltinCandidateTypeSet { 3136 /// TypeSet - A set of types. 3137 typedef llvm::SmallPtrSet<QualType, 8> TypeSet; 3138 3139 /// PointerTypes - The set of pointer types that will be used in the 3140 /// built-in candidates. 3141 TypeSet PointerTypes; 3142 3143 /// MemberPointerTypes - The set of member pointer types that will be 3144 /// used in the built-in candidates. 3145 TypeSet MemberPointerTypes; 3146 3147 /// EnumerationTypes - The set of enumeration types that will be 3148 /// used in the built-in candidates. 3149 TypeSet EnumerationTypes; 3150 3151 /// Sema - The semantic analysis instance where we are building the 3152 /// candidate type set. 3153 Sema &SemaRef; 3154 3155 /// Context - The AST context in which we will build the type sets. 3156 ASTContext &Context; 3157 3158 bool AddPointerWithMoreQualifiedTypeVariants(QualType Ty, 3159 const Qualifiers &VisibleQuals); 3160 bool AddMemberPointerWithMoreQualifiedTypeVariants(QualType Ty); 3161 3162public: 3163 /// iterator - Iterates through the types that are part of the set. 3164 typedef TypeSet::iterator iterator; 3165 3166 BuiltinCandidateTypeSet(Sema &SemaRef) 3167 : SemaRef(SemaRef), Context(SemaRef.Context) { } 3168 3169 void AddTypesConvertedFrom(QualType Ty, 3170 SourceLocation Loc, 3171 bool AllowUserConversions, 3172 bool AllowExplicitConversions, 3173 const Qualifiers &VisibleTypeConversionsQuals); 3174 3175 /// pointer_begin - First pointer type found; 3176 iterator pointer_begin() { return PointerTypes.begin(); } 3177 3178 /// pointer_end - Past the last pointer type found; 3179 iterator pointer_end() { return PointerTypes.end(); } 3180 3181 /// member_pointer_begin - First member pointer type found; 3182 iterator member_pointer_begin() { return MemberPointerTypes.begin(); } 3183 3184 /// member_pointer_end - Past the last member pointer type found; 3185 iterator member_pointer_end() { return MemberPointerTypes.end(); } 3186 3187 /// enumeration_begin - First enumeration type found; 3188 iterator enumeration_begin() { return EnumerationTypes.begin(); } 3189 3190 /// enumeration_end - Past the last enumeration type found; 3191 iterator enumeration_end() { return EnumerationTypes.end(); } 3192}; 3193 3194/// AddPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty to 3195/// the set of pointer types along with any more-qualified variants of 3196/// that type. For example, if @p Ty is "int const *", this routine 3197/// will add "int const *", "int const volatile *", "int const 3198/// restrict *", and "int const volatile restrict *" to the set of 3199/// pointer types. Returns true if the add of @p Ty itself succeeded, 3200/// false otherwise. 3201/// 3202/// FIXME: what to do about extended qualifiers? 3203bool 3204BuiltinCandidateTypeSet::AddPointerWithMoreQualifiedTypeVariants(QualType Ty, 3205 const Qualifiers &VisibleQuals) { 3206 3207 // Insert this type. 3208 if (!PointerTypes.insert(Ty)) 3209 return false; 3210 3211 const PointerType *PointerTy = Ty->getAs<PointerType>(); 3212 assert(PointerTy && "type was not a pointer type!"); 3213 3214 QualType PointeeTy = PointerTy->getPointeeType(); 3215 // Don't add qualified variants of arrays. For one, they're not allowed 3216 // (the qualifier would sink to the element type), and for another, the 3217 // only overload situation where it matters is subscript or pointer +- int, 3218 // and those shouldn't have qualifier variants anyway. 3219 if (PointeeTy->isArrayType()) 3220 return true; 3221 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 3222 if (const ConstantArrayType *Array =Context.getAsConstantArrayType(PointeeTy)) 3223 BaseCVR = Array->getElementType().getCVRQualifiers(); 3224 bool hasVolatile = VisibleQuals.hasVolatile(); 3225 bool hasRestrict = VisibleQuals.hasRestrict(); 3226 3227 // Iterate through all strict supersets of BaseCVR. 3228 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 3229 if ((CVR | BaseCVR) != CVR) continue; 3230 // Skip over Volatile/Restrict if no Volatile/Restrict found anywhere 3231 // in the types. 3232 if ((CVR & Qualifiers::Volatile) && !hasVolatile) continue; 3233 if ((CVR & Qualifiers::Restrict) && !hasRestrict) continue; 3234 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 3235 PointerTypes.insert(Context.getPointerType(QPointeeTy)); 3236 } 3237 3238 return true; 3239} 3240 3241/// AddMemberPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty 3242/// to the set of pointer types along with any more-qualified variants of 3243/// that type. For example, if @p Ty is "int const *", this routine 3244/// will add "int const *", "int const volatile *", "int const 3245/// restrict *", and "int const volatile restrict *" to the set of 3246/// pointer types. Returns true if the add of @p Ty itself succeeded, 3247/// false otherwise. 3248/// 3249/// FIXME: what to do about extended qualifiers? 3250bool 3251BuiltinCandidateTypeSet::AddMemberPointerWithMoreQualifiedTypeVariants( 3252 QualType Ty) { 3253 // Insert this type. 3254 if (!MemberPointerTypes.insert(Ty)) 3255 return false; 3256 3257 const MemberPointerType *PointerTy = Ty->getAs<MemberPointerType>(); 3258 assert(PointerTy && "type was not a member pointer type!"); 3259 3260 QualType PointeeTy = PointerTy->getPointeeType(); 3261 // Don't add qualified variants of arrays. For one, they're not allowed 3262 // (the qualifier would sink to the element type), and for another, the 3263 // only overload situation where it matters is subscript or pointer +- int, 3264 // and those shouldn't have qualifier variants anyway. 3265 if (PointeeTy->isArrayType()) 3266 return true; 3267 const Type *ClassTy = PointerTy->getClass(); 3268 3269 // Iterate through all strict supersets of the pointee type's CVR 3270 // qualifiers. 3271 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 3272 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 3273 if ((CVR | BaseCVR) != CVR) continue; 3274 3275 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 3276 MemberPointerTypes.insert(Context.getMemberPointerType(QPointeeTy, ClassTy)); 3277 } 3278 3279 return true; 3280} 3281 3282/// AddTypesConvertedFrom - Add each of the types to which the type @p 3283/// Ty can be implicit converted to the given set of @p Types. We're 3284/// primarily interested in pointer types and enumeration types. We also 3285/// take member pointer types, for the conditional operator. 3286/// AllowUserConversions is true if we should look at the conversion 3287/// functions of a class type, and AllowExplicitConversions if we 3288/// should also include the explicit conversion functions of a class 3289/// type. 3290void 3291BuiltinCandidateTypeSet::AddTypesConvertedFrom(QualType Ty, 3292 SourceLocation Loc, 3293 bool AllowUserConversions, 3294 bool AllowExplicitConversions, 3295 const Qualifiers &VisibleQuals) { 3296 // Only deal with canonical types. 3297 Ty = Context.getCanonicalType(Ty); 3298 3299 // Look through reference types; they aren't part of the type of an 3300 // expression for the purposes of conversions. 3301 if (const ReferenceType *RefTy = Ty->getAs<ReferenceType>()) 3302 Ty = RefTy->getPointeeType(); 3303 3304 // We don't care about qualifiers on the type. 3305 Ty = Ty.getLocalUnqualifiedType(); 3306 3307 // If we're dealing with an array type, decay to the pointer. 3308 if (Ty->isArrayType()) 3309 Ty = SemaRef.Context.getArrayDecayedType(Ty); 3310 3311 if (const PointerType *PointerTy = Ty->getAs<PointerType>()) { 3312 QualType PointeeTy = PointerTy->getPointeeType(); 3313 3314 // Insert our type, and its more-qualified variants, into the set 3315 // of types. 3316 if (!AddPointerWithMoreQualifiedTypeVariants(Ty, VisibleQuals)) 3317 return; 3318 } else if (Ty->isMemberPointerType()) { 3319 // Member pointers are far easier, since the pointee can't be converted. 3320 if (!AddMemberPointerWithMoreQualifiedTypeVariants(Ty)) 3321 return; 3322 } else if (Ty->isEnumeralType()) { 3323 EnumerationTypes.insert(Ty); 3324 } else if (AllowUserConversions) { 3325 if (const RecordType *TyRec = Ty->getAs<RecordType>()) { 3326 if (SemaRef.RequireCompleteType(Loc, Ty, 0)) { 3327 // No conversion functions in incomplete types. 3328 return; 3329 } 3330 3331 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 3332 const UnresolvedSetImpl *Conversions 3333 = ClassDecl->getVisibleConversionFunctions(); 3334 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 3335 E = Conversions->end(); I != E; ++I) { 3336 3337 // Skip conversion function templates; they don't tell us anything 3338 // about which builtin types we can convert to. 3339 if (isa<FunctionTemplateDecl>(*I)) 3340 continue; 3341 3342 CXXConversionDecl *Conv = cast<CXXConversionDecl>(*I); 3343 if (AllowExplicitConversions || !Conv->isExplicit()) { 3344 AddTypesConvertedFrom(Conv->getConversionType(), Loc, false, false, 3345 VisibleQuals); 3346 } 3347 } 3348 } 3349 } 3350} 3351 3352/// \brief Helper function for AddBuiltinOperatorCandidates() that adds 3353/// the volatile- and non-volatile-qualified assignment operators for the 3354/// given type to the candidate set. 3355static void AddBuiltinAssignmentOperatorCandidates(Sema &S, 3356 QualType T, 3357 Expr **Args, 3358 unsigned NumArgs, 3359 OverloadCandidateSet &CandidateSet) { 3360 QualType ParamTypes[2]; 3361 3362 // T& operator=(T&, T) 3363 ParamTypes[0] = S.Context.getLValueReferenceType(T); 3364 ParamTypes[1] = T; 3365 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3366 /*IsAssignmentOperator=*/true); 3367 3368 if (!S.Context.getCanonicalType(T).isVolatileQualified()) { 3369 // volatile T& operator=(volatile T&, T) 3370 ParamTypes[0] 3371 = S.Context.getLValueReferenceType(S.Context.getVolatileType(T)); 3372 ParamTypes[1] = T; 3373 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3374 /*IsAssignmentOperator=*/true); 3375 } 3376} 3377 3378/// CollectVRQualifiers - This routine returns Volatile/Restrict qualifiers, 3379/// if any, found in visible type conversion functions found in ArgExpr's type. 3380static Qualifiers CollectVRQualifiers(ASTContext &Context, Expr* ArgExpr) { 3381 Qualifiers VRQuals; 3382 const RecordType *TyRec; 3383 if (const MemberPointerType *RHSMPType = 3384 ArgExpr->getType()->getAs<MemberPointerType>()) 3385 TyRec = cast<RecordType>(RHSMPType->getClass()); 3386 else 3387 TyRec = ArgExpr->getType()->getAs<RecordType>(); 3388 if (!TyRec) { 3389 // Just to be safe, assume the worst case. 3390 VRQuals.addVolatile(); 3391 VRQuals.addRestrict(); 3392 return VRQuals; 3393 } 3394 3395 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 3396 if (!ClassDecl->hasDefinition()) 3397 return VRQuals; 3398 3399 const UnresolvedSetImpl *Conversions = 3400 ClassDecl->getVisibleConversionFunctions(); 3401 3402 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 3403 E = Conversions->end(); I != E; ++I) { 3404 if (CXXConversionDecl *Conv = dyn_cast<CXXConversionDecl>(*I)) { 3405 QualType CanTy = Context.getCanonicalType(Conv->getConversionType()); 3406 if (const ReferenceType *ResTypeRef = CanTy->getAs<ReferenceType>()) 3407 CanTy = ResTypeRef->getPointeeType(); 3408 // Need to go down the pointer/mempointer chain and add qualifiers 3409 // as see them. 3410 bool done = false; 3411 while (!done) { 3412 if (const PointerType *ResTypePtr = CanTy->getAs<PointerType>()) 3413 CanTy = ResTypePtr->getPointeeType(); 3414 else if (const MemberPointerType *ResTypeMPtr = 3415 CanTy->getAs<MemberPointerType>()) 3416 CanTy = ResTypeMPtr->getPointeeType(); 3417 else 3418 done = true; 3419 if (CanTy.isVolatileQualified()) 3420 VRQuals.addVolatile(); 3421 if (CanTy.isRestrictQualified()) 3422 VRQuals.addRestrict(); 3423 if (VRQuals.hasRestrict() && VRQuals.hasVolatile()) 3424 return VRQuals; 3425 } 3426 } 3427 } 3428 return VRQuals; 3429} 3430 3431/// AddBuiltinOperatorCandidates - Add the appropriate built-in 3432/// operator overloads to the candidate set (C++ [over.built]), based 3433/// on the operator @p Op and the arguments given. For example, if the 3434/// operator is a binary '+', this routine might add "int 3435/// operator+(int, int)" to cover integer addition. 3436void 3437Sema::AddBuiltinOperatorCandidates(OverloadedOperatorKind Op, 3438 SourceLocation OpLoc, 3439 Expr **Args, unsigned NumArgs, 3440 OverloadCandidateSet& CandidateSet) { 3441 // The set of "promoted arithmetic types", which are the arithmetic 3442 // types are that preserved by promotion (C++ [over.built]p2). Note 3443 // that the first few of these types are the promoted integral 3444 // types; these types need to be first. 3445 // FIXME: What about complex? 3446 const unsigned FirstIntegralType = 0; 3447 const unsigned LastIntegralType = 13; 3448 const unsigned FirstPromotedIntegralType = 7, 3449 LastPromotedIntegralType = 13; 3450 const unsigned FirstPromotedArithmeticType = 7, 3451 LastPromotedArithmeticType = 16; 3452 const unsigned NumArithmeticTypes = 16; 3453 QualType ArithmeticTypes[NumArithmeticTypes] = { 3454 Context.BoolTy, Context.CharTy, Context.WCharTy, 3455// FIXME: Context.Char16Ty, Context.Char32Ty, 3456 Context.SignedCharTy, Context.ShortTy, 3457 Context.UnsignedCharTy, Context.UnsignedShortTy, 3458 Context.IntTy, Context.LongTy, Context.LongLongTy, 3459 Context.UnsignedIntTy, Context.UnsignedLongTy, Context.UnsignedLongLongTy, 3460 Context.FloatTy, Context.DoubleTy, Context.LongDoubleTy 3461 }; 3462 assert(ArithmeticTypes[FirstPromotedIntegralType] == Context.IntTy && 3463 "Invalid first promoted integral type"); 3464 assert(ArithmeticTypes[LastPromotedIntegralType - 1] 3465 == Context.UnsignedLongLongTy && 3466 "Invalid last promoted integral type"); 3467 assert(ArithmeticTypes[FirstPromotedArithmeticType] == Context.IntTy && 3468 "Invalid first promoted arithmetic type"); 3469 assert(ArithmeticTypes[LastPromotedArithmeticType - 1] 3470 == Context.LongDoubleTy && 3471 "Invalid last promoted arithmetic type"); 3472 3473 // Find all of the types that the arguments can convert to, but only 3474 // if the operator we're looking at has built-in operator candidates 3475 // that make use of these types. 3476 Qualifiers VisibleTypeConversionsQuals; 3477 VisibleTypeConversionsQuals.addConst(); 3478 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 3479 VisibleTypeConversionsQuals += CollectVRQualifiers(Context, Args[ArgIdx]); 3480 3481 BuiltinCandidateTypeSet CandidateTypes(*this); 3482 if (Op == OO_Less || Op == OO_Greater || Op == OO_LessEqual || 3483 Op == OO_GreaterEqual || Op == OO_EqualEqual || Op == OO_ExclaimEqual || 3484 Op == OO_Plus || (Op == OO_Minus && NumArgs == 2) || Op == OO_Equal || 3485 Op == OO_PlusEqual || Op == OO_MinusEqual || Op == OO_Subscript || 3486 Op == OO_ArrowStar || Op == OO_PlusPlus || Op == OO_MinusMinus || 3487 (Op == OO_Star && NumArgs == 1) || Op == OO_Conditional) { 3488 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 3489 CandidateTypes.AddTypesConvertedFrom(Args[ArgIdx]->getType(), 3490 OpLoc, 3491 true, 3492 (Op == OO_Exclaim || 3493 Op == OO_AmpAmp || 3494 Op == OO_PipePipe), 3495 VisibleTypeConversionsQuals); 3496 } 3497 3498 bool isComparison = false; 3499 switch (Op) { 3500 case OO_None: 3501 case NUM_OVERLOADED_OPERATORS: 3502 assert(false && "Expected an overloaded operator"); 3503 break; 3504 3505 case OO_Star: // '*' is either unary or binary 3506 if (NumArgs == 1) 3507 goto UnaryStar; 3508 else 3509 goto BinaryStar; 3510 break; 3511 3512 case OO_Plus: // '+' is either unary or binary 3513 if (NumArgs == 1) 3514 goto UnaryPlus; 3515 else 3516 goto BinaryPlus; 3517 break; 3518 3519 case OO_Minus: // '-' is either unary or binary 3520 if (NumArgs == 1) 3521 goto UnaryMinus; 3522 else 3523 goto BinaryMinus; 3524 break; 3525 3526 case OO_Amp: // '&' is either unary or binary 3527 if (NumArgs == 1) 3528 goto UnaryAmp; 3529 else 3530 goto BinaryAmp; 3531 3532 case OO_PlusPlus: 3533 case OO_MinusMinus: 3534 // C++ [over.built]p3: 3535 // 3536 // For every pair (T, VQ), where T is an arithmetic type, and VQ 3537 // is either volatile or empty, there exist candidate operator 3538 // functions of the form 3539 // 3540 // VQ T& operator++(VQ T&); 3541 // T operator++(VQ T&, int); 3542 // 3543 // C++ [over.built]p4: 3544 // 3545 // For every pair (T, VQ), where T is an arithmetic type other 3546 // than bool, and VQ is either volatile or empty, there exist 3547 // candidate operator functions of the form 3548 // 3549 // VQ T& operator--(VQ T&); 3550 // T operator--(VQ T&, int); 3551 for (unsigned Arith = (Op == OO_PlusPlus? 0 : 1); 3552 Arith < NumArithmeticTypes; ++Arith) { 3553 QualType ArithTy = ArithmeticTypes[Arith]; 3554 QualType ParamTypes[2] 3555 = { Context.getLValueReferenceType(ArithTy), Context.IntTy }; 3556 3557 // Non-volatile version. 3558 if (NumArgs == 1) 3559 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3560 else 3561 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 3562 // heuristic to reduce number of builtin candidates in the set. 3563 // Add volatile version only if there are conversions to a volatile type. 3564 if (VisibleTypeConversionsQuals.hasVolatile()) { 3565 // Volatile version 3566 ParamTypes[0] 3567 = Context.getLValueReferenceType(Context.getVolatileType(ArithTy)); 3568 if (NumArgs == 1) 3569 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3570 else 3571 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 3572 } 3573 } 3574 3575 // C++ [over.built]p5: 3576 // 3577 // For every pair (T, VQ), where T is a cv-qualified or 3578 // cv-unqualified object type, and VQ is either volatile or 3579 // empty, there exist candidate operator functions of the form 3580 // 3581 // T*VQ& operator++(T*VQ&); 3582 // T*VQ& operator--(T*VQ&); 3583 // T* operator++(T*VQ&, int); 3584 // T* operator--(T*VQ&, int); 3585 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3586 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3587 // Skip pointer types that aren't pointers to object types. 3588 if (!(*Ptr)->getAs<PointerType>()->getPointeeType()->isObjectType()) 3589 continue; 3590 3591 QualType ParamTypes[2] = { 3592 Context.getLValueReferenceType(*Ptr), Context.IntTy 3593 }; 3594 3595 // Without volatile 3596 if (NumArgs == 1) 3597 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3598 else 3599 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3600 3601 if (!Context.getCanonicalType(*Ptr).isVolatileQualified() && 3602 VisibleTypeConversionsQuals.hasVolatile()) { 3603 // With volatile 3604 ParamTypes[0] 3605 = Context.getLValueReferenceType(Context.getVolatileType(*Ptr)); 3606 if (NumArgs == 1) 3607 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3608 else 3609 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3610 } 3611 } 3612 break; 3613 3614 UnaryStar: 3615 // C++ [over.built]p6: 3616 // For every cv-qualified or cv-unqualified object type T, there 3617 // exist candidate operator functions of the form 3618 // 3619 // T& operator*(T*); 3620 // 3621 // C++ [over.built]p7: 3622 // For every function type T, there exist candidate operator 3623 // functions of the form 3624 // T& operator*(T*); 3625 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3626 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3627 QualType ParamTy = *Ptr; 3628 QualType PointeeTy = ParamTy->getAs<PointerType>()->getPointeeType(); 3629 AddBuiltinCandidate(Context.getLValueReferenceType(PointeeTy), 3630 &ParamTy, Args, 1, CandidateSet); 3631 } 3632 break; 3633 3634 UnaryPlus: 3635 // C++ [over.built]p8: 3636 // For every type T, there exist candidate operator functions of 3637 // the form 3638 // 3639 // T* operator+(T*); 3640 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3641 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3642 QualType ParamTy = *Ptr; 3643 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet); 3644 } 3645 3646 // Fall through 3647 3648 UnaryMinus: 3649 // C++ [over.built]p9: 3650 // For every promoted arithmetic type T, there exist candidate 3651 // operator functions of the form 3652 // 3653 // T operator+(T); 3654 // T operator-(T); 3655 for (unsigned Arith = FirstPromotedArithmeticType; 3656 Arith < LastPromotedArithmeticType; ++Arith) { 3657 QualType ArithTy = ArithmeticTypes[Arith]; 3658 AddBuiltinCandidate(ArithTy, &ArithTy, Args, 1, CandidateSet); 3659 } 3660 break; 3661 3662 case OO_Tilde: 3663 // C++ [over.built]p10: 3664 // For every promoted integral type T, there exist candidate 3665 // operator functions of the form 3666 // 3667 // T operator~(T); 3668 for (unsigned Int = FirstPromotedIntegralType; 3669 Int < LastPromotedIntegralType; ++Int) { 3670 QualType IntTy = ArithmeticTypes[Int]; 3671 AddBuiltinCandidate(IntTy, &IntTy, Args, 1, CandidateSet); 3672 } 3673 break; 3674 3675 case OO_New: 3676 case OO_Delete: 3677 case OO_Array_New: 3678 case OO_Array_Delete: 3679 case OO_Call: 3680 assert(false && "Special operators don't use AddBuiltinOperatorCandidates"); 3681 break; 3682 3683 case OO_Comma: 3684 UnaryAmp: 3685 case OO_Arrow: 3686 // C++ [over.match.oper]p3: 3687 // -- For the operator ',', the unary operator '&', or the 3688 // operator '->', the built-in candidates set is empty. 3689 break; 3690 3691 case OO_EqualEqual: 3692 case OO_ExclaimEqual: 3693 // C++ [over.match.oper]p16: 3694 // For every pointer to member type T, there exist candidate operator 3695 // functions of the form 3696 // 3697 // bool operator==(T,T); 3698 // bool operator!=(T,T); 3699 for (BuiltinCandidateTypeSet::iterator 3700 MemPtr = CandidateTypes.member_pointer_begin(), 3701 MemPtrEnd = CandidateTypes.member_pointer_end(); 3702 MemPtr != MemPtrEnd; 3703 ++MemPtr) { 3704 QualType ParamTypes[2] = { *MemPtr, *MemPtr }; 3705 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 3706 } 3707 3708 // Fall through 3709 3710 case OO_Less: 3711 case OO_Greater: 3712 case OO_LessEqual: 3713 case OO_GreaterEqual: 3714 // C++ [over.built]p15: 3715 // 3716 // For every pointer or enumeration type T, there exist 3717 // candidate operator functions of the form 3718 // 3719 // bool operator<(T, T); 3720 // bool operator>(T, T); 3721 // bool operator<=(T, T); 3722 // bool operator>=(T, T); 3723 // bool operator==(T, T); 3724 // bool operator!=(T, T); 3725 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3726 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3727 QualType ParamTypes[2] = { *Ptr, *Ptr }; 3728 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 3729 } 3730 for (BuiltinCandidateTypeSet::iterator Enum 3731 = CandidateTypes.enumeration_begin(); 3732 Enum != CandidateTypes.enumeration_end(); ++Enum) { 3733 QualType ParamTypes[2] = { *Enum, *Enum }; 3734 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 3735 } 3736 3737 // Fall through. 3738 isComparison = true; 3739 3740 BinaryPlus: 3741 BinaryMinus: 3742 if (!isComparison) { 3743 // We didn't fall through, so we must have OO_Plus or OO_Minus. 3744 3745 // C++ [over.built]p13: 3746 // 3747 // For every cv-qualified or cv-unqualified object type T 3748 // there exist candidate operator functions of the form 3749 // 3750 // T* operator+(T*, ptrdiff_t); 3751 // T& operator[](T*, ptrdiff_t); [BELOW] 3752 // T* operator-(T*, ptrdiff_t); 3753 // T* operator+(ptrdiff_t, T*); 3754 // T& operator[](ptrdiff_t, T*); [BELOW] 3755 // 3756 // C++ [over.built]p14: 3757 // 3758 // For every T, where T is a pointer to object type, there 3759 // exist candidate operator functions of the form 3760 // 3761 // ptrdiff_t operator-(T, T); 3762 for (BuiltinCandidateTypeSet::iterator Ptr 3763 = CandidateTypes.pointer_begin(); 3764 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3765 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 3766 3767 // operator+(T*, ptrdiff_t) or operator-(T*, ptrdiff_t) 3768 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3769 3770 if (Op == OO_Plus) { 3771 // T* operator+(ptrdiff_t, T*); 3772 ParamTypes[0] = ParamTypes[1]; 3773 ParamTypes[1] = *Ptr; 3774 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3775 } else { 3776 // ptrdiff_t operator-(T, T); 3777 ParamTypes[1] = *Ptr; 3778 AddBuiltinCandidate(Context.getPointerDiffType(), ParamTypes, 3779 Args, 2, CandidateSet); 3780 } 3781 } 3782 } 3783 // Fall through 3784 3785 case OO_Slash: 3786 BinaryStar: 3787 Conditional: 3788 // C++ [over.built]p12: 3789 // 3790 // For every pair of promoted arithmetic types L and R, there 3791 // exist candidate operator functions of the form 3792 // 3793 // LR operator*(L, R); 3794 // LR operator/(L, R); 3795 // LR operator+(L, R); 3796 // LR operator-(L, R); 3797 // bool operator<(L, R); 3798 // bool operator>(L, R); 3799 // bool operator<=(L, R); 3800 // bool operator>=(L, R); 3801 // bool operator==(L, R); 3802 // bool operator!=(L, R); 3803 // 3804 // where LR is the result of the usual arithmetic conversions 3805 // between types L and R. 3806 // 3807 // C++ [over.built]p24: 3808 // 3809 // For every pair of promoted arithmetic types L and R, there exist 3810 // candidate operator functions of the form 3811 // 3812 // LR operator?(bool, L, R); 3813 // 3814 // where LR is the result of the usual arithmetic conversions 3815 // between types L and R. 3816 // Our candidates ignore the first parameter. 3817 for (unsigned Left = FirstPromotedArithmeticType; 3818 Left < LastPromotedArithmeticType; ++Left) { 3819 for (unsigned Right = FirstPromotedArithmeticType; 3820 Right < LastPromotedArithmeticType; ++Right) { 3821 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 3822 QualType Result 3823 = isComparison 3824 ? Context.BoolTy 3825 : Context.UsualArithmeticConversionsType(LandR[0], LandR[1]); 3826 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 3827 } 3828 } 3829 break; 3830 3831 case OO_Percent: 3832 BinaryAmp: 3833 case OO_Caret: 3834 case OO_Pipe: 3835 case OO_LessLess: 3836 case OO_GreaterGreater: 3837 // C++ [over.built]p17: 3838 // 3839 // For every pair of promoted integral types L and R, there 3840 // exist candidate operator functions of the form 3841 // 3842 // LR operator%(L, R); 3843 // LR operator&(L, R); 3844 // LR operator^(L, R); 3845 // LR operator|(L, R); 3846 // L operator<<(L, R); 3847 // L operator>>(L, R); 3848 // 3849 // where LR is the result of the usual arithmetic conversions 3850 // between types L and R. 3851 for (unsigned Left = FirstPromotedIntegralType; 3852 Left < LastPromotedIntegralType; ++Left) { 3853 for (unsigned Right = FirstPromotedIntegralType; 3854 Right < LastPromotedIntegralType; ++Right) { 3855 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 3856 QualType Result = (Op == OO_LessLess || Op == OO_GreaterGreater) 3857 ? LandR[0] 3858 : Context.UsualArithmeticConversionsType(LandR[0], LandR[1]); 3859 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 3860 } 3861 } 3862 break; 3863 3864 case OO_Equal: 3865 // C++ [over.built]p20: 3866 // 3867 // For every pair (T, VQ), where T is an enumeration or 3868 // pointer to member type and VQ is either volatile or 3869 // empty, there exist candidate operator functions of the form 3870 // 3871 // VQ T& operator=(VQ T&, T); 3872 for (BuiltinCandidateTypeSet::iterator 3873 Enum = CandidateTypes.enumeration_begin(), 3874 EnumEnd = CandidateTypes.enumeration_end(); 3875 Enum != EnumEnd; ++Enum) 3876 AddBuiltinAssignmentOperatorCandidates(*this, *Enum, Args, 2, 3877 CandidateSet); 3878 for (BuiltinCandidateTypeSet::iterator 3879 MemPtr = CandidateTypes.member_pointer_begin(), 3880 MemPtrEnd = CandidateTypes.member_pointer_end(); 3881 MemPtr != MemPtrEnd; ++MemPtr) 3882 AddBuiltinAssignmentOperatorCandidates(*this, *MemPtr, Args, 2, 3883 CandidateSet); 3884 // Fall through. 3885 3886 case OO_PlusEqual: 3887 case OO_MinusEqual: 3888 // C++ [over.built]p19: 3889 // 3890 // For every pair (T, VQ), where T is any type and VQ is either 3891 // volatile or empty, there exist candidate operator functions 3892 // of the form 3893 // 3894 // T*VQ& operator=(T*VQ&, T*); 3895 // 3896 // C++ [over.built]p21: 3897 // 3898 // For every pair (T, VQ), where T is a cv-qualified or 3899 // cv-unqualified object type and VQ is either volatile or 3900 // empty, there exist candidate operator functions of the form 3901 // 3902 // T*VQ& operator+=(T*VQ&, ptrdiff_t); 3903 // T*VQ& operator-=(T*VQ&, ptrdiff_t); 3904 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3905 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3906 QualType ParamTypes[2]; 3907 ParamTypes[1] = (Op == OO_Equal)? *Ptr : Context.getPointerDiffType(); 3908 3909 // non-volatile version 3910 ParamTypes[0] = Context.getLValueReferenceType(*Ptr); 3911 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3912 /*IsAssigmentOperator=*/Op == OO_Equal); 3913 3914 if (!Context.getCanonicalType(*Ptr).isVolatileQualified() && 3915 VisibleTypeConversionsQuals.hasVolatile()) { 3916 // volatile version 3917 ParamTypes[0] 3918 = Context.getLValueReferenceType(Context.getVolatileType(*Ptr)); 3919 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3920 /*IsAssigmentOperator=*/Op == OO_Equal); 3921 } 3922 } 3923 // Fall through. 3924 3925 case OO_StarEqual: 3926 case OO_SlashEqual: 3927 // C++ [over.built]p18: 3928 // 3929 // For every triple (L, VQ, R), where L is an arithmetic type, 3930 // VQ is either volatile or empty, and R is a promoted 3931 // arithmetic type, there exist candidate operator functions of 3932 // the form 3933 // 3934 // VQ L& operator=(VQ L&, R); 3935 // VQ L& operator*=(VQ L&, R); 3936 // VQ L& operator/=(VQ L&, R); 3937 // VQ L& operator+=(VQ L&, R); 3938 // VQ L& operator-=(VQ L&, R); 3939 for (unsigned Left = 0; Left < NumArithmeticTypes; ++Left) { 3940 for (unsigned Right = FirstPromotedArithmeticType; 3941 Right < LastPromotedArithmeticType; ++Right) { 3942 QualType ParamTypes[2]; 3943 ParamTypes[1] = ArithmeticTypes[Right]; 3944 3945 // Add this built-in operator as a candidate (VQ is empty). 3946 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 3947 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3948 /*IsAssigmentOperator=*/Op == OO_Equal); 3949 3950 // Add this built-in operator as a candidate (VQ is 'volatile'). 3951 if (VisibleTypeConversionsQuals.hasVolatile()) { 3952 ParamTypes[0] = Context.getVolatileType(ArithmeticTypes[Left]); 3953 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 3954 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3955 /*IsAssigmentOperator=*/Op == OO_Equal); 3956 } 3957 } 3958 } 3959 break; 3960 3961 case OO_PercentEqual: 3962 case OO_LessLessEqual: 3963 case OO_GreaterGreaterEqual: 3964 case OO_AmpEqual: 3965 case OO_CaretEqual: 3966 case OO_PipeEqual: 3967 // C++ [over.built]p22: 3968 // 3969 // For every triple (L, VQ, R), where L is an integral type, VQ 3970 // is either volatile or empty, and R is a promoted integral 3971 // type, there exist candidate operator functions of the form 3972 // 3973 // VQ L& operator%=(VQ L&, R); 3974 // VQ L& operator<<=(VQ L&, R); 3975 // VQ L& operator>>=(VQ L&, R); 3976 // VQ L& operator&=(VQ L&, R); 3977 // VQ L& operator^=(VQ L&, R); 3978 // VQ L& operator|=(VQ L&, R); 3979 for (unsigned Left = FirstIntegralType; Left < LastIntegralType; ++Left) { 3980 for (unsigned Right = FirstPromotedIntegralType; 3981 Right < LastPromotedIntegralType; ++Right) { 3982 QualType ParamTypes[2]; 3983 ParamTypes[1] = ArithmeticTypes[Right]; 3984 3985 // Add this built-in operator as a candidate (VQ is empty). 3986 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 3987 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 3988 if (VisibleTypeConversionsQuals.hasVolatile()) { 3989 // Add this built-in operator as a candidate (VQ is 'volatile'). 3990 ParamTypes[0] = ArithmeticTypes[Left]; 3991 ParamTypes[0] = Context.getVolatileType(ParamTypes[0]); 3992 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 3993 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 3994 } 3995 } 3996 } 3997 break; 3998 3999 case OO_Exclaim: { 4000 // C++ [over.operator]p23: 4001 // 4002 // There also exist candidate operator functions of the form 4003 // 4004 // bool operator!(bool); 4005 // bool operator&&(bool, bool); [BELOW] 4006 // bool operator||(bool, bool); [BELOW] 4007 QualType ParamTy = Context.BoolTy; 4008 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet, 4009 /*IsAssignmentOperator=*/false, 4010 /*NumContextualBoolArguments=*/1); 4011 break; 4012 } 4013 4014 case OO_AmpAmp: 4015 case OO_PipePipe: { 4016 // C++ [over.operator]p23: 4017 // 4018 // There also exist candidate operator functions of the form 4019 // 4020 // bool operator!(bool); [ABOVE] 4021 // bool operator&&(bool, bool); 4022 // bool operator||(bool, bool); 4023 QualType ParamTypes[2] = { Context.BoolTy, Context.BoolTy }; 4024 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet, 4025 /*IsAssignmentOperator=*/false, 4026 /*NumContextualBoolArguments=*/2); 4027 break; 4028 } 4029 4030 case OO_Subscript: 4031 // C++ [over.built]p13: 4032 // 4033 // For every cv-qualified or cv-unqualified object type T there 4034 // exist candidate operator functions of the form 4035 // 4036 // T* operator+(T*, ptrdiff_t); [ABOVE] 4037 // T& operator[](T*, ptrdiff_t); 4038 // T* operator-(T*, ptrdiff_t); [ABOVE] 4039 // T* operator+(ptrdiff_t, T*); [ABOVE] 4040 // T& operator[](ptrdiff_t, T*); 4041 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 4042 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4043 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 4044 QualType PointeeType = (*Ptr)->getAs<PointerType>()->getPointeeType(); 4045 QualType ResultTy = Context.getLValueReferenceType(PointeeType); 4046 4047 // T& operator[](T*, ptrdiff_t) 4048 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 4049 4050 // T& operator[](ptrdiff_t, T*); 4051 ParamTypes[0] = ParamTypes[1]; 4052 ParamTypes[1] = *Ptr; 4053 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 4054 } 4055 break; 4056 4057 case OO_ArrowStar: 4058 // C++ [over.built]p11: 4059 // For every quintuple (C1, C2, T, CV1, CV2), where C2 is a class type, 4060 // C1 is the same type as C2 or is a derived class of C2, T is an object 4061 // type or a function type, and CV1 and CV2 are cv-qualifier-seqs, 4062 // there exist candidate operator functions of the form 4063 // CV12 T& operator->*(CV1 C1*, CV2 T C2::*); 4064 // where CV12 is the union of CV1 and CV2. 4065 { 4066 for (BuiltinCandidateTypeSet::iterator Ptr = 4067 CandidateTypes.pointer_begin(); 4068 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4069 QualType C1Ty = (*Ptr); 4070 QualType C1; 4071 QualifierCollector Q1; 4072 if (const PointerType *PointerTy = C1Ty->getAs<PointerType>()) { 4073 C1 = QualType(Q1.strip(PointerTy->getPointeeType()), 0); 4074 if (!isa<RecordType>(C1)) 4075 continue; 4076 // heuristic to reduce number of builtin candidates in the set. 4077 // Add volatile/restrict version only if there are conversions to a 4078 // volatile/restrict type. 4079 if (!VisibleTypeConversionsQuals.hasVolatile() && Q1.hasVolatile()) 4080 continue; 4081 if (!VisibleTypeConversionsQuals.hasRestrict() && Q1.hasRestrict()) 4082 continue; 4083 } 4084 for (BuiltinCandidateTypeSet::iterator 4085 MemPtr = CandidateTypes.member_pointer_begin(), 4086 MemPtrEnd = CandidateTypes.member_pointer_end(); 4087 MemPtr != MemPtrEnd; ++MemPtr) { 4088 const MemberPointerType *mptr = cast<MemberPointerType>(*MemPtr); 4089 QualType C2 = QualType(mptr->getClass(), 0); 4090 C2 = C2.getUnqualifiedType(); 4091 if (C1 != C2 && !IsDerivedFrom(C1, C2)) 4092 break; 4093 QualType ParamTypes[2] = { *Ptr, *MemPtr }; 4094 // build CV12 T& 4095 QualType T = mptr->getPointeeType(); 4096 if (!VisibleTypeConversionsQuals.hasVolatile() && 4097 T.isVolatileQualified()) 4098 continue; 4099 if (!VisibleTypeConversionsQuals.hasRestrict() && 4100 T.isRestrictQualified()) 4101 continue; 4102 T = Q1.apply(T); 4103 QualType ResultTy = Context.getLValueReferenceType(T); 4104 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 4105 } 4106 } 4107 } 4108 break; 4109 4110 case OO_Conditional: 4111 // Note that we don't consider the first argument, since it has been 4112 // contextually converted to bool long ago. The candidates below are 4113 // therefore added as binary. 4114 // 4115 // C++ [over.built]p24: 4116 // For every type T, where T is a pointer or pointer-to-member type, 4117 // there exist candidate operator functions of the form 4118 // 4119 // T operator?(bool, T, T); 4120 // 4121 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(), 4122 E = CandidateTypes.pointer_end(); Ptr != E; ++Ptr) { 4123 QualType ParamTypes[2] = { *Ptr, *Ptr }; 4124 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 4125 } 4126 for (BuiltinCandidateTypeSet::iterator Ptr = 4127 CandidateTypes.member_pointer_begin(), 4128 E = CandidateTypes.member_pointer_end(); Ptr != E; ++Ptr) { 4129 QualType ParamTypes[2] = { *Ptr, *Ptr }; 4130 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 4131 } 4132 goto Conditional; 4133 } 4134} 4135 4136/// \brief Add function candidates found via argument-dependent lookup 4137/// to the set of overloading candidates. 4138/// 4139/// This routine performs argument-dependent name lookup based on the 4140/// given function name (which may also be an operator name) and adds 4141/// all of the overload candidates found by ADL to the overload 4142/// candidate set (C++ [basic.lookup.argdep]). 4143void 4144Sema::AddArgumentDependentLookupCandidates(DeclarationName Name, 4145 bool Operator, 4146 Expr **Args, unsigned NumArgs, 4147 const TemplateArgumentListInfo *ExplicitTemplateArgs, 4148 OverloadCandidateSet& CandidateSet, 4149 bool PartialOverloading) { 4150 ADLResult Fns; 4151 4152 // FIXME: This approach for uniquing ADL results (and removing 4153 // redundant candidates from the set) relies on pointer-equality, 4154 // which means we need to key off the canonical decl. However, 4155 // always going back to the canonical decl might not get us the 4156 // right set of default arguments. What default arguments are 4157 // we supposed to consider on ADL candidates, anyway? 4158 4159 // FIXME: Pass in the explicit template arguments? 4160 ArgumentDependentLookup(Name, Operator, Args, NumArgs, Fns); 4161 4162 // Erase all of the candidates we already knew about. 4163 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 4164 CandEnd = CandidateSet.end(); 4165 Cand != CandEnd; ++Cand) 4166 if (Cand->Function) { 4167 Fns.erase(Cand->Function); 4168 if (FunctionTemplateDecl *FunTmpl = Cand->Function->getPrimaryTemplate()) 4169 Fns.erase(FunTmpl); 4170 } 4171 4172 // For each of the ADL candidates we found, add it to the overload 4173 // set. 4174 for (ADLResult::iterator I = Fns.begin(), E = Fns.end(); I != E; ++I) { 4175 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*I)) { 4176 if (ExplicitTemplateArgs) 4177 continue; 4178 4179 AddOverloadCandidate(FD, AS_none, Args, NumArgs, CandidateSet, 4180 false, false, PartialOverloading); 4181 } else 4182 AddTemplateOverloadCandidate(cast<FunctionTemplateDecl>(*I), 4183 AS_none, ExplicitTemplateArgs, 4184 Args, NumArgs, CandidateSet); 4185 } 4186} 4187 4188/// isBetterOverloadCandidate - Determines whether the first overload 4189/// candidate is a better candidate than the second (C++ 13.3.3p1). 4190bool 4191Sema::isBetterOverloadCandidate(const OverloadCandidate& Cand1, 4192 const OverloadCandidate& Cand2, 4193 SourceLocation Loc) { 4194 // Define viable functions to be better candidates than non-viable 4195 // functions. 4196 if (!Cand2.Viable) 4197 return Cand1.Viable; 4198 else if (!Cand1.Viable) 4199 return false; 4200 4201 // C++ [over.match.best]p1: 4202 // 4203 // -- if F is a static member function, ICS1(F) is defined such 4204 // that ICS1(F) is neither better nor worse than ICS1(G) for 4205 // any function G, and, symmetrically, ICS1(G) is neither 4206 // better nor worse than ICS1(F). 4207 unsigned StartArg = 0; 4208 if (Cand1.IgnoreObjectArgument || Cand2.IgnoreObjectArgument) 4209 StartArg = 1; 4210 4211 // C++ [over.match.best]p1: 4212 // A viable function F1 is defined to be a better function than another 4213 // viable function F2 if for all arguments i, ICSi(F1) is not a worse 4214 // conversion sequence than ICSi(F2), and then... 4215 unsigned NumArgs = Cand1.Conversions.size(); 4216 assert(Cand2.Conversions.size() == NumArgs && "Overload candidate mismatch"); 4217 bool HasBetterConversion = false; 4218 for (unsigned ArgIdx = StartArg; ArgIdx < NumArgs; ++ArgIdx) { 4219 switch (CompareImplicitConversionSequences(Cand1.Conversions[ArgIdx], 4220 Cand2.Conversions[ArgIdx])) { 4221 case ImplicitConversionSequence::Better: 4222 // Cand1 has a better conversion sequence. 4223 HasBetterConversion = true; 4224 break; 4225 4226 case ImplicitConversionSequence::Worse: 4227 // Cand1 can't be better than Cand2. 4228 return false; 4229 4230 case ImplicitConversionSequence::Indistinguishable: 4231 // Do nothing. 4232 break; 4233 } 4234 } 4235 4236 // -- for some argument j, ICSj(F1) is a better conversion sequence than 4237 // ICSj(F2), or, if not that, 4238 if (HasBetterConversion) 4239 return true; 4240 4241 // - F1 is a non-template function and F2 is a function template 4242 // specialization, or, if not that, 4243 if (Cand1.Function && !Cand1.Function->getPrimaryTemplate() && 4244 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 4245 return true; 4246 4247 // -- F1 and F2 are function template specializations, and the function 4248 // template for F1 is more specialized than the template for F2 4249 // according to the partial ordering rules described in 14.5.5.2, or, 4250 // if not that, 4251 if (Cand1.Function && Cand1.Function->getPrimaryTemplate() && 4252 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 4253 if (FunctionTemplateDecl *BetterTemplate 4254 = getMoreSpecializedTemplate(Cand1.Function->getPrimaryTemplate(), 4255 Cand2.Function->getPrimaryTemplate(), 4256 Loc, 4257 isa<CXXConversionDecl>(Cand1.Function)? TPOC_Conversion 4258 : TPOC_Call)) 4259 return BetterTemplate == Cand1.Function->getPrimaryTemplate(); 4260 4261 // -- the context is an initialization by user-defined conversion 4262 // (see 8.5, 13.3.1.5) and the standard conversion sequence 4263 // from the return type of F1 to the destination type (i.e., 4264 // the type of the entity being initialized) is a better 4265 // conversion sequence than the standard conversion sequence 4266 // from the return type of F2 to the destination type. 4267 if (Cand1.Function && Cand2.Function && 4268 isa<CXXConversionDecl>(Cand1.Function) && 4269 isa<CXXConversionDecl>(Cand2.Function)) { 4270 switch (CompareStandardConversionSequences(Cand1.FinalConversion, 4271 Cand2.FinalConversion)) { 4272 case ImplicitConversionSequence::Better: 4273 // Cand1 has a better conversion sequence. 4274 return true; 4275 4276 case ImplicitConversionSequence::Worse: 4277 // Cand1 can't be better than Cand2. 4278 return false; 4279 4280 case ImplicitConversionSequence::Indistinguishable: 4281 // Do nothing 4282 break; 4283 } 4284 } 4285 4286 return false; 4287} 4288 4289/// \brief Computes the best viable function (C++ 13.3.3) 4290/// within an overload candidate set. 4291/// 4292/// \param CandidateSet the set of candidate functions. 4293/// 4294/// \param Loc the location of the function name (or operator symbol) for 4295/// which overload resolution occurs. 4296/// 4297/// \param Best f overload resolution was successful or found a deleted 4298/// function, Best points to the candidate function found. 4299/// 4300/// \returns The result of overload resolution. 4301OverloadingResult Sema::BestViableFunction(OverloadCandidateSet& CandidateSet, 4302 SourceLocation Loc, 4303 OverloadCandidateSet::iterator& Best) { 4304 // Find the best viable function. 4305 Best = CandidateSet.end(); 4306 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 4307 Cand != CandidateSet.end(); ++Cand) { 4308 if (Cand->Viable) { 4309 if (Best == CandidateSet.end() || 4310 isBetterOverloadCandidate(*Cand, *Best, Loc)) 4311 Best = Cand; 4312 } 4313 } 4314 4315 // If we didn't find any viable functions, abort. 4316 if (Best == CandidateSet.end()) 4317 return OR_No_Viable_Function; 4318 4319 // Make sure that this function is better than every other viable 4320 // function. If not, we have an ambiguity. 4321 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 4322 Cand != CandidateSet.end(); ++Cand) { 4323 if (Cand->Viable && 4324 Cand != Best && 4325 !isBetterOverloadCandidate(*Best, *Cand, Loc)) { 4326 Best = CandidateSet.end(); 4327 return OR_Ambiguous; 4328 } 4329 } 4330 4331 // Best is the best viable function. 4332 if (Best->Function && 4333 (Best->Function->isDeleted() || 4334 Best->Function->getAttr<UnavailableAttr>())) 4335 return OR_Deleted; 4336 4337 // C++ [basic.def.odr]p2: 4338 // An overloaded function is used if it is selected by overload resolution 4339 // when referred to from a potentially-evaluated expression. [Note: this 4340 // covers calls to named functions (5.2.2), operator overloading 4341 // (clause 13), user-defined conversions (12.3.2), allocation function for 4342 // placement new (5.3.4), as well as non-default initialization (8.5). 4343 if (Best->Function) 4344 MarkDeclarationReferenced(Loc, Best->Function); 4345 return OR_Success; 4346} 4347 4348namespace { 4349 4350enum OverloadCandidateKind { 4351 oc_function, 4352 oc_method, 4353 oc_constructor, 4354 oc_function_template, 4355 oc_method_template, 4356 oc_constructor_template, 4357 oc_implicit_default_constructor, 4358 oc_implicit_copy_constructor, 4359 oc_implicit_copy_assignment 4360}; 4361 4362OverloadCandidateKind ClassifyOverloadCandidate(Sema &S, 4363 FunctionDecl *Fn, 4364 std::string &Description) { 4365 bool isTemplate = false; 4366 4367 if (FunctionTemplateDecl *FunTmpl = Fn->getPrimaryTemplate()) { 4368 isTemplate = true; 4369 Description = S.getTemplateArgumentBindingsText( 4370 FunTmpl->getTemplateParameters(), *Fn->getTemplateSpecializationArgs()); 4371 } 4372 4373 if (CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(Fn)) { 4374 if (!Ctor->isImplicit()) 4375 return isTemplate ? oc_constructor_template : oc_constructor; 4376 4377 return Ctor->isCopyConstructor() ? oc_implicit_copy_constructor 4378 : oc_implicit_default_constructor; 4379 } 4380 4381 if (CXXMethodDecl *Meth = dyn_cast<CXXMethodDecl>(Fn)) { 4382 // This actually gets spelled 'candidate function' for now, but 4383 // it doesn't hurt to split it out. 4384 if (!Meth->isImplicit()) 4385 return isTemplate ? oc_method_template : oc_method; 4386 4387 assert(Meth->isCopyAssignment() 4388 && "implicit method is not copy assignment operator?"); 4389 return oc_implicit_copy_assignment; 4390 } 4391 4392 return isTemplate ? oc_function_template : oc_function; 4393} 4394 4395} // end anonymous namespace 4396 4397// Notes the location of an overload candidate. 4398void Sema::NoteOverloadCandidate(FunctionDecl *Fn) { 4399 std::string FnDesc; 4400 OverloadCandidateKind K = ClassifyOverloadCandidate(*this, Fn, FnDesc); 4401 Diag(Fn->getLocation(), diag::note_ovl_candidate) 4402 << (unsigned) K << FnDesc; 4403} 4404 4405/// Diagnoses an ambiguous conversion. The partial diagnostic is the 4406/// "lead" diagnostic; it will be given two arguments, the source and 4407/// target types of the conversion. 4408void Sema::DiagnoseAmbiguousConversion(const ImplicitConversionSequence &ICS, 4409 SourceLocation CaretLoc, 4410 const PartialDiagnostic &PDiag) { 4411 Diag(CaretLoc, PDiag) 4412 << ICS.Ambiguous.getFromType() << ICS.Ambiguous.getToType(); 4413 for (AmbiguousConversionSequence::const_iterator 4414 I = ICS.Ambiguous.begin(), E = ICS.Ambiguous.end(); I != E; ++I) { 4415 NoteOverloadCandidate(*I); 4416 } 4417} 4418 4419namespace { 4420 4421void DiagnoseBadConversion(Sema &S, OverloadCandidate *Cand, unsigned I) { 4422 const ImplicitConversionSequence &Conv = Cand->Conversions[I]; 4423 assert(Conv.isBad()); 4424 assert(Cand->Function && "for now, candidate must be a function"); 4425 FunctionDecl *Fn = Cand->Function; 4426 4427 // There's a conversion slot for the object argument if this is a 4428 // non-constructor method. Note that 'I' corresponds the 4429 // conversion-slot index. 4430 bool isObjectArgument = false; 4431 if (isa<CXXMethodDecl>(Fn) && !isa<CXXConstructorDecl>(Fn)) { 4432 if (I == 0) 4433 isObjectArgument = true; 4434 else 4435 I--; 4436 } 4437 4438 std::string FnDesc; 4439 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, FnDesc); 4440 4441 Expr *FromExpr = Conv.Bad.FromExpr; 4442 QualType FromTy = Conv.Bad.getFromType(); 4443 QualType ToTy = Conv.Bad.getToType(); 4444 4445 if (FromTy == S.Context.OverloadTy) { 4446 assert(FromExpr && "overload set argument came from implicit argument?"); 4447 Expr *E = FromExpr->IgnoreParens(); 4448 if (isa<UnaryOperator>(E)) 4449 E = cast<UnaryOperator>(E)->getSubExpr()->IgnoreParens(); 4450 DeclarationName Name = cast<OverloadExpr>(E)->getName(); 4451 4452 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_overload) 4453 << (unsigned) FnKind << FnDesc 4454 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 4455 << ToTy << Name << I+1; 4456 return; 4457 } 4458 4459 // Do some hand-waving analysis to see if the non-viability is due 4460 // to a qualifier mismatch. 4461 CanQualType CFromTy = S.Context.getCanonicalType(FromTy); 4462 CanQualType CToTy = S.Context.getCanonicalType(ToTy); 4463 if (CanQual<ReferenceType> RT = CToTy->getAs<ReferenceType>()) 4464 CToTy = RT->getPointeeType(); 4465 else { 4466 // TODO: detect and diagnose the full richness of const mismatches. 4467 if (CanQual<PointerType> FromPT = CFromTy->getAs<PointerType>()) 4468 if (CanQual<PointerType> ToPT = CToTy->getAs<PointerType>()) 4469 CFromTy = FromPT->getPointeeType(), CToTy = ToPT->getPointeeType(); 4470 } 4471 4472 if (CToTy.getUnqualifiedType() == CFromTy.getUnqualifiedType() && 4473 !CToTy.isAtLeastAsQualifiedAs(CFromTy)) { 4474 // It is dumb that we have to do this here. 4475 while (isa<ArrayType>(CFromTy)) 4476 CFromTy = CFromTy->getAs<ArrayType>()->getElementType(); 4477 while (isa<ArrayType>(CToTy)) 4478 CToTy = CFromTy->getAs<ArrayType>()->getElementType(); 4479 4480 Qualifiers FromQs = CFromTy.getQualifiers(); 4481 Qualifiers ToQs = CToTy.getQualifiers(); 4482 4483 if (FromQs.getAddressSpace() != ToQs.getAddressSpace()) { 4484 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_addrspace) 4485 << (unsigned) FnKind << FnDesc 4486 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 4487 << FromTy 4488 << FromQs.getAddressSpace() << ToQs.getAddressSpace() 4489 << (unsigned) isObjectArgument << I+1; 4490 return; 4491 } 4492 4493 unsigned CVR = FromQs.getCVRQualifiers() & ~ToQs.getCVRQualifiers(); 4494 assert(CVR && "unexpected qualifiers mismatch"); 4495 4496 if (isObjectArgument) { 4497 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr_this) 4498 << (unsigned) FnKind << FnDesc 4499 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 4500 << FromTy << (CVR - 1); 4501 } else { 4502 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr) 4503 << (unsigned) FnKind << FnDesc 4504 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 4505 << FromTy << (CVR - 1) << I+1; 4506 } 4507 return; 4508 } 4509 4510 // Diagnose references or pointers to incomplete types differently, 4511 // since it's far from impossible that the incompleteness triggered 4512 // the failure. 4513 QualType TempFromTy = FromTy.getNonReferenceType(); 4514 if (const PointerType *PTy = TempFromTy->getAs<PointerType>()) 4515 TempFromTy = PTy->getPointeeType(); 4516 if (TempFromTy->isIncompleteType()) { 4517 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_conv_incomplete) 4518 << (unsigned) FnKind << FnDesc 4519 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 4520 << FromTy << ToTy << (unsigned) isObjectArgument << I+1; 4521 return; 4522 } 4523 4524 // TODO: specialize more based on the kind of mismatch 4525 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_conv) 4526 << (unsigned) FnKind << FnDesc 4527 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 4528 << FromTy << ToTy << (unsigned) isObjectArgument << I+1; 4529} 4530 4531void DiagnoseArityMismatch(Sema &S, OverloadCandidate *Cand, 4532 unsigned NumFormalArgs) { 4533 // TODO: treat calls to a missing default constructor as a special case 4534 4535 FunctionDecl *Fn = Cand->Function; 4536 const FunctionProtoType *FnTy = Fn->getType()->getAs<FunctionProtoType>(); 4537 4538 unsigned MinParams = Fn->getMinRequiredArguments(); 4539 4540 // at least / at most / exactly 4541 unsigned mode, modeCount; 4542 if (NumFormalArgs < MinParams) { 4543 assert(Cand->FailureKind == ovl_fail_too_few_arguments); 4544 if (MinParams != FnTy->getNumArgs() || FnTy->isVariadic()) 4545 mode = 0; // "at least" 4546 else 4547 mode = 2; // "exactly" 4548 modeCount = MinParams; 4549 } else { 4550 assert(Cand->FailureKind == ovl_fail_too_many_arguments); 4551 if (MinParams != FnTy->getNumArgs()) 4552 mode = 1; // "at most" 4553 else 4554 mode = 2; // "exactly" 4555 modeCount = FnTy->getNumArgs(); 4556 } 4557 4558 std::string Description; 4559 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, Description); 4560 4561 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_arity) 4562 << (unsigned) FnKind << Description << mode << modeCount << NumFormalArgs; 4563} 4564 4565/// Diagnose a failed template-argument deduction. 4566void DiagnoseBadDeduction(Sema &S, OverloadCandidate *Cand, 4567 Expr **Args, unsigned NumArgs) { 4568 FunctionDecl *Fn = Cand->Function; // pattern 4569 4570 TemplateParameter Param = TemplateParameter::getFromOpaqueValue( 4571 Cand->DeductionFailure.TemplateParameter); 4572 4573 switch (Cand->DeductionFailure.Result) { 4574 case Sema::TDK_Success: 4575 llvm_unreachable("TDK_success while diagnosing bad deduction"); 4576 4577 case Sema::TDK_Incomplete: { 4578 NamedDecl *ParamD; 4579 (ParamD = Param.dyn_cast<TemplateTypeParmDecl*>()) || 4580 (ParamD = Param.dyn_cast<NonTypeTemplateParmDecl*>()) || 4581 (ParamD = Param.dyn_cast<TemplateTemplateParmDecl*>()); 4582 assert(ParamD && "no parameter found for incomplete deduction result"); 4583 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_incomplete_deduction) 4584 << ParamD->getDeclName(); 4585 return; 4586 } 4587 4588 // TODO: diagnose these individually, then kill off 4589 // note_ovl_candidate_bad_deduction, which is uselessly vague. 4590 case Sema::TDK_InstantiationDepth: 4591 case Sema::TDK_Inconsistent: 4592 case Sema::TDK_InconsistentQuals: 4593 case Sema::TDK_SubstitutionFailure: 4594 case Sema::TDK_NonDeducedMismatch: 4595 case Sema::TDK_TooManyArguments: 4596 case Sema::TDK_TooFewArguments: 4597 case Sema::TDK_InvalidExplicitArguments: 4598 case Sema::TDK_FailedOverloadResolution: 4599 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_deduction); 4600 return; 4601 } 4602} 4603 4604/// Generates a 'note' diagnostic for an overload candidate. We've 4605/// already generated a primary error at the call site. 4606/// 4607/// It really does need to be a single diagnostic with its caret 4608/// pointed at the candidate declaration. Yes, this creates some 4609/// major challenges of technical writing. Yes, this makes pointing 4610/// out problems with specific arguments quite awkward. It's still 4611/// better than generating twenty screens of text for every failed 4612/// overload. 4613/// 4614/// It would be great to be able to express per-candidate problems 4615/// more richly for those diagnostic clients that cared, but we'd 4616/// still have to be just as careful with the default diagnostics. 4617void NoteFunctionCandidate(Sema &S, OverloadCandidate *Cand, 4618 Expr **Args, unsigned NumArgs) { 4619 FunctionDecl *Fn = Cand->Function; 4620 4621 // Note deleted candidates, but only if they're viable. 4622 if (Cand->Viable && (Fn->isDeleted() || Fn->hasAttr<UnavailableAttr>())) { 4623 std::string FnDesc; 4624 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, FnDesc); 4625 4626 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_deleted) 4627 << FnKind << FnDesc << Fn->isDeleted(); 4628 return; 4629 } 4630 4631 // We don't really have anything else to say about viable candidates. 4632 if (Cand->Viable) { 4633 S.NoteOverloadCandidate(Fn); 4634 return; 4635 } 4636 4637 switch (Cand->FailureKind) { 4638 case ovl_fail_too_many_arguments: 4639 case ovl_fail_too_few_arguments: 4640 return DiagnoseArityMismatch(S, Cand, NumArgs); 4641 4642 case ovl_fail_bad_deduction: 4643 return DiagnoseBadDeduction(S, Cand, Args, NumArgs); 4644 4645 case ovl_fail_trivial_conversion: 4646 case ovl_fail_bad_final_conversion: 4647 return S.NoteOverloadCandidate(Fn); 4648 4649 case ovl_fail_bad_conversion: { 4650 unsigned I = (Cand->IgnoreObjectArgument ? 1 : 0); 4651 for (unsigned N = Cand->Conversions.size(); I != N; ++I) 4652 if (Cand->Conversions[I].isBad()) 4653 return DiagnoseBadConversion(S, Cand, I); 4654 4655 // FIXME: this currently happens when we're called from SemaInit 4656 // when user-conversion overload fails. Figure out how to handle 4657 // those conditions and diagnose them well. 4658 return S.NoteOverloadCandidate(Fn); 4659 } 4660 } 4661} 4662 4663void NoteSurrogateCandidate(Sema &S, OverloadCandidate *Cand) { 4664 // Desugar the type of the surrogate down to a function type, 4665 // retaining as many typedefs as possible while still showing 4666 // the function type (and, therefore, its parameter types). 4667 QualType FnType = Cand->Surrogate->getConversionType(); 4668 bool isLValueReference = false; 4669 bool isRValueReference = false; 4670 bool isPointer = false; 4671 if (const LValueReferenceType *FnTypeRef = 4672 FnType->getAs<LValueReferenceType>()) { 4673 FnType = FnTypeRef->getPointeeType(); 4674 isLValueReference = true; 4675 } else if (const RValueReferenceType *FnTypeRef = 4676 FnType->getAs<RValueReferenceType>()) { 4677 FnType = FnTypeRef->getPointeeType(); 4678 isRValueReference = true; 4679 } 4680 if (const PointerType *FnTypePtr = FnType->getAs<PointerType>()) { 4681 FnType = FnTypePtr->getPointeeType(); 4682 isPointer = true; 4683 } 4684 // Desugar down to a function type. 4685 FnType = QualType(FnType->getAs<FunctionType>(), 0); 4686 // Reconstruct the pointer/reference as appropriate. 4687 if (isPointer) FnType = S.Context.getPointerType(FnType); 4688 if (isRValueReference) FnType = S.Context.getRValueReferenceType(FnType); 4689 if (isLValueReference) FnType = S.Context.getLValueReferenceType(FnType); 4690 4691 S.Diag(Cand->Surrogate->getLocation(), diag::note_ovl_surrogate_cand) 4692 << FnType; 4693} 4694 4695void NoteBuiltinOperatorCandidate(Sema &S, 4696 const char *Opc, 4697 SourceLocation OpLoc, 4698 OverloadCandidate *Cand) { 4699 assert(Cand->Conversions.size() <= 2 && "builtin operator is not binary"); 4700 std::string TypeStr("operator"); 4701 TypeStr += Opc; 4702 TypeStr += "("; 4703 TypeStr += Cand->BuiltinTypes.ParamTypes[0].getAsString(); 4704 if (Cand->Conversions.size() == 1) { 4705 TypeStr += ")"; 4706 S.Diag(OpLoc, diag::note_ovl_builtin_unary_candidate) << TypeStr; 4707 } else { 4708 TypeStr += ", "; 4709 TypeStr += Cand->BuiltinTypes.ParamTypes[1].getAsString(); 4710 TypeStr += ")"; 4711 S.Diag(OpLoc, diag::note_ovl_builtin_binary_candidate) << TypeStr; 4712 } 4713} 4714 4715void NoteAmbiguousUserConversions(Sema &S, SourceLocation OpLoc, 4716 OverloadCandidate *Cand) { 4717 unsigned NoOperands = Cand->Conversions.size(); 4718 for (unsigned ArgIdx = 0; ArgIdx < NoOperands; ++ArgIdx) { 4719 const ImplicitConversionSequence &ICS = Cand->Conversions[ArgIdx]; 4720 if (ICS.isBad()) break; // all meaningless after first invalid 4721 if (!ICS.isAmbiguous()) continue; 4722 4723 S.DiagnoseAmbiguousConversion(ICS, OpLoc, 4724 PDiag(diag::note_ambiguous_type_conversion)); 4725 } 4726} 4727 4728SourceLocation GetLocationForCandidate(const OverloadCandidate *Cand) { 4729 if (Cand->Function) 4730 return Cand->Function->getLocation(); 4731 if (Cand->IsSurrogate) 4732 return Cand->Surrogate->getLocation(); 4733 return SourceLocation(); 4734} 4735 4736struct CompareOverloadCandidatesForDisplay { 4737 Sema &S; 4738 CompareOverloadCandidatesForDisplay(Sema &S) : S(S) {} 4739 4740 bool operator()(const OverloadCandidate *L, 4741 const OverloadCandidate *R) { 4742 // Fast-path this check. 4743 if (L == R) return false; 4744 4745 // Order first by viability. 4746 if (L->Viable) { 4747 if (!R->Viable) return true; 4748 4749 // TODO: introduce a tri-valued comparison for overload 4750 // candidates. Would be more worthwhile if we had a sort 4751 // that could exploit it. 4752 if (S.isBetterOverloadCandidate(*L, *R, SourceLocation())) return true; 4753 if (S.isBetterOverloadCandidate(*R, *L, SourceLocation())) return false; 4754 } else if (R->Viable) 4755 return false; 4756 4757 assert(L->Viable == R->Viable); 4758 4759 // Criteria by which we can sort non-viable candidates: 4760 if (!L->Viable) { 4761 // 1. Arity mismatches come after other candidates. 4762 if (L->FailureKind == ovl_fail_too_many_arguments || 4763 L->FailureKind == ovl_fail_too_few_arguments) 4764 return false; 4765 if (R->FailureKind == ovl_fail_too_many_arguments || 4766 R->FailureKind == ovl_fail_too_few_arguments) 4767 return true; 4768 4769 // 2. Bad conversions come first and are ordered by the number 4770 // of bad conversions and quality of good conversions. 4771 if (L->FailureKind == ovl_fail_bad_conversion) { 4772 if (R->FailureKind != ovl_fail_bad_conversion) 4773 return true; 4774 4775 // If there's any ordering between the defined conversions... 4776 // FIXME: this might not be transitive. 4777 assert(L->Conversions.size() == R->Conversions.size()); 4778 4779 int leftBetter = 0; 4780 unsigned I = (L->IgnoreObjectArgument || R->IgnoreObjectArgument); 4781 for (unsigned E = L->Conversions.size(); I != E; ++I) { 4782 switch (S.CompareImplicitConversionSequences(L->Conversions[I], 4783 R->Conversions[I])) { 4784 case ImplicitConversionSequence::Better: 4785 leftBetter++; 4786 break; 4787 4788 case ImplicitConversionSequence::Worse: 4789 leftBetter--; 4790 break; 4791 4792 case ImplicitConversionSequence::Indistinguishable: 4793 break; 4794 } 4795 } 4796 if (leftBetter > 0) return true; 4797 if (leftBetter < 0) return false; 4798 4799 } else if (R->FailureKind == ovl_fail_bad_conversion) 4800 return false; 4801 4802 // TODO: others? 4803 } 4804 4805 // Sort everything else by location. 4806 SourceLocation LLoc = GetLocationForCandidate(L); 4807 SourceLocation RLoc = GetLocationForCandidate(R); 4808 4809 // Put candidates without locations (e.g. builtins) at the end. 4810 if (LLoc.isInvalid()) return false; 4811 if (RLoc.isInvalid()) return true; 4812 4813 return S.SourceMgr.isBeforeInTranslationUnit(LLoc, RLoc); 4814 } 4815}; 4816 4817/// CompleteNonViableCandidate - Normally, overload resolution only 4818/// computes up to the first 4819void CompleteNonViableCandidate(Sema &S, OverloadCandidate *Cand, 4820 Expr **Args, unsigned NumArgs) { 4821 assert(!Cand->Viable); 4822 4823 // Don't do anything on failures other than bad conversion. 4824 if (Cand->FailureKind != ovl_fail_bad_conversion) return; 4825 4826 // Skip forward to the first bad conversion. 4827 unsigned ConvIdx = (Cand->IgnoreObjectArgument ? 1 : 0); 4828 unsigned ConvCount = Cand->Conversions.size(); 4829 while (true) { 4830 assert(ConvIdx != ConvCount && "no bad conversion in candidate"); 4831 ConvIdx++; 4832 if (Cand->Conversions[ConvIdx - 1].isBad()) 4833 break; 4834 } 4835 4836 if (ConvIdx == ConvCount) 4837 return; 4838 4839 assert(!Cand->Conversions[ConvIdx].isInitialized() && 4840 "remaining conversion is initialized?"); 4841 4842 // FIXME: these should probably be preserved from the overload 4843 // operation somehow. 4844 bool SuppressUserConversions = false; 4845 bool ForceRValue = false; 4846 4847 const FunctionProtoType* Proto; 4848 unsigned ArgIdx = ConvIdx; 4849 4850 if (Cand->IsSurrogate) { 4851 QualType ConvType 4852 = Cand->Surrogate->getConversionType().getNonReferenceType(); 4853 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 4854 ConvType = ConvPtrType->getPointeeType(); 4855 Proto = ConvType->getAs<FunctionProtoType>(); 4856 ArgIdx--; 4857 } else if (Cand->Function) { 4858 Proto = Cand->Function->getType()->getAs<FunctionProtoType>(); 4859 if (isa<CXXMethodDecl>(Cand->Function) && 4860 !isa<CXXConstructorDecl>(Cand->Function)) 4861 ArgIdx--; 4862 } else { 4863 // Builtin binary operator with a bad first conversion. 4864 assert(ConvCount <= 3); 4865 for (; ConvIdx != ConvCount; ++ConvIdx) 4866 Cand->Conversions[ConvIdx] 4867 = S.TryCopyInitialization(Args[ConvIdx], 4868 Cand->BuiltinTypes.ParamTypes[ConvIdx], 4869 SuppressUserConversions, ForceRValue, 4870 /*InOverloadResolution*/ true); 4871 return; 4872 } 4873 4874 // Fill in the rest of the conversions. 4875 unsigned NumArgsInProto = Proto->getNumArgs(); 4876 for (; ConvIdx != ConvCount; ++ConvIdx, ++ArgIdx) { 4877 if (ArgIdx < NumArgsInProto) 4878 Cand->Conversions[ConvIdx] 4879 = S.TryCopyInitialization(Args[ArgIdx], Proto->getArgType(ArgIdx), 4880 SuppressUserConversions, ForceRValue, 4881 /*InOverloadResolution=*/true); 4882 else 4883 Cand->Conversions[ConvIdx].setEllipsis(); 4884 } 4885} 4886 4887} // end anonymous namespace 4888 4889/// PrintOverloadCandidates - When overload resolution fails, prints 4890/// diagnostic messages containing the candidates in the candidate 4891/// set. 4892void 4893Sema::PrintOverloadCandidates(OverloadCandidateSet& CandidateSet, 4894 OverloadCandidateDisplayKind OCD, 4895 Expr **Args, unsigned NumArgs, 4896 const char *Opc, 4897 SourceLocation OpLoc) { 4898 // Sort the candidates by viability and position. Sorting directly would 4899 // be prohibitive, so we make a set of pointers and sort those. 4900 llvm::SmallVector<OverloadCandidate*, 32> Cands; 4901 if (OCD == OCD_AllCandidates) Cands.reserve(CandidateSet.size()); 4902 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 4903 LastCand = CandidateSet.end(); 4904 Cand != LastCand; ++Cand) { 4905 if (Cand->Viable) 4906 Cands.push_back(Cand); 4907 else if (OCD == OCD_AllCandidates) { 4908 CompleteNonViableCandidate(*this, Cand, Args, NumArgs); 4909 Cands.push_back(Cand); 4910 } 4911 } 4912 4913 std::sort(Cands.begin(), Cands.end(), 4914 CompareOverloadCandidatesForDisplay(*this)); 4915 4916 bool ReportedAmbiguousConversions = false; 4917 4918 llvm::SmallVectorImpl<OverloadCandidate*>::iterator I, E; 4919 for (I = Cands.begin(), E = Cands.end(); I != E; ++I) { 4920 OverloadCandidate *Cand = *I; 4921 4922 if (Cand->Function) 4923 NoteFunctionCandidate(*this, Cand, Args, NumArgs); 4924 else if (Cand->IsSurrogate) 4925 NoteSurrogateCandidate(*this, Cand); 4926 4927 // This a builtin candidate. We do not, in general, want to list 4928 // every possible builtin candidate. 4929 else if (Cand->Viable) { 4930 // Generally we only see ambiguities including viable builtin 4931 // operators if overload resolution got screwed up by an 4932 // ambiguous user-defined conversion. 4933 // 4934 // FIXME: It's quite possible for different conversions to see 4935 // different ambiguities, though. 4936 if (!ReportedAmbiguousConversions) { 4937 NoteAmbiguousUserConversions(*this, OpLoc, Cand); 4938 ReportedAmbiguousConversions = true; 4939 } 4940 4941 // If this is a viable builtin, print it. 4942 NoteBuiltinOperatorCandidate(*this, Opc, OpLoc, Cand); 4943 } 4944 } 4945} 4946 4947static bool CheckUnresolvedAccess(Sema &S, OverloadExpr *E, NamedDecl *D, 4948 AccessSpecifier AS) { 4949 if (isa<UnresolvedLookupExpr>(E)) 4950 return S.CheckUnresolvedLookupAccess(cast<UnresolvedLookupExpr>(E), D, AS); 4951 4952 return S.CheckUnresolvedMemberAccess(cast<UnresolvedMemberExpr>(E), D, AS); 4953} 4954 4955/// ResolveAddressOfOverloadedFunction - Try to resolve the address of 4956/// an overloaded function (C++ [over.over]), where @p From is an 4957/// expression with overloaded function type and @p ToType is the type 4958/// we're trying to resolve to. For example: 4959/// 4960/// @code 4961/// int f(double); 4962/// int f(int); 4963/// 4964/// int (*pfd)(double) = f; // selects f(double) 4965/// @endcode 4966/// 4967/// This routine returns the resulting FunctionDecl if it could be 4968/// resolved, and NULL otherwise. When @p Complain is true, this 4969/// routine will emit diagnostics if there is an error. 4970FunctionDecl * 4971Sema::ResolveAddressOfOverloadedFunction(Expr *From, QualType ToType, 4972 bool Complain) { 4973 QualType FunctionType = ToType; 4974 bool IsMember = false; 4975 if (const PointerType *ToTypePtr = ToType->getAs<PointerType>()) 4976 FunctionType = ToTypePtr->getPointeeType(); 4977 else if (const ReferenceType *ToTypeRef = ToType->getAs<ReferenceType>()) 4978 FunctionType = ToTypeRef->getPointeeType(); 4979 else if (const MemberPointerType *MemTypePtr = 4980 ToType->getAs<MemberPointerType>()) { 4981 FunctionType = MemTypePtr->getPointeeType(); 4982 IsMember = true; 4983 } 4984 4985 // We only look at pointers or references to functions. 4986 FunctionType = Context.getCanonicalType(FunctionType).getUnqualifiedType(); 4987 if (!FunctionType->isFunctionType()) 4988 return 0; 4989 4990 // Find the actual overloaded function declaration. 4991 if (From->getType() != Context.OverloadTy) 4992 return 0; 4993 4994 // C++ [over.over]p1: 4995 // [...] [Note: any redundant set of parentheses surrounding the 4996 // overloaded function name is ignored (5.1). ] 4997 // C++ [over.over]p1: 4998 // [...] The overloaded function name can be preceded by the & 4999 // operator. 5000 OverloadExpr *OvlExpr = OverloadExpr::find(From).getPointer(); 5001 TemplateArgumentListInfo ETABuffer, *ExplicitTemplateArgs = 0; 5002 if (OvlExpr->hasExplicitTemplateArgs()) { 5003 OvlExpr->getExplicitTemplateArgs().copyInto(ETABuffer); 5004 ExplicitTemplateArgs = &ETABuffer; 5005 } 5006 5007 // Look through all of the overloaded functions, searching for one 5008 // whose type matches exactly. 5009 UnresolvedSet<4> Matches; // contains only FunctionDecls 5010 bool FoundNonTemplateFunction = false; 5011 for (UnresolvedSetIterator I = OvlExpr->decls_begin(), 5012 E = OvlExpr->decls_end(); I != E; ++I) { 5013 // Look through any using declarations to find the underlying function. 5014 NamedDecl *Fn = (*I)->getUnderlyingDecl(); 5015 5016 // C++ [over.over]p3: 5017 // Non-member functions and static member functions match 5018 // targets of type "pointer-to-function" or "reference-to-function." 5019 // Nonstatic member functions match targets of 5020 // type "pointer-to-member-function." 5021 // Note that according to DR 247, the containing class does not matter. 5022 5023 if (FunctionTemplateDecl *FunctionTemplate 5024 = dyn_cast<FunctionTemplateDecl>(Fn)) { 5025 if (CXXMethodDecl *Method 5026 = dyn_cast<CXXMethodDecl>(FunctionTemplate->getTemplatedDecl())) { 5027 // Skip non-static function templates when converting to pointer, and 5028 // static when converting to member pointer. 5029 if (Method->isStatic() == IsMember) 5030 continue; 5031 } else if (IsMember) 5032 continue; 5033 5034 // C++ [over.over]p2: 5035 // If the name is a function template, template argument deduction is 5036 // done (14.8.2.2), and if the argument deduction succeeds, the 5037 // resulting template argument list is used to generate a single 5038 // function template specialization, which is added to the set of 5039 // overloaded functions considered. 5040 // FIXME: We don't really want to build the specialization here, do we? 5041 FunctionDecl *Specialization = 0; 5042 TemplateDeductionInfo Info(Context, OvlExpr->getNameLoc()); 5043 if (TemplateDeductionResult Result 5044 = DeduceTemplateArguments(FunctionTemplate, ExplicitTemplateArgs, 5045 FunctionType, Specialization, Info)) { 5046 // FIXME: make a note of the failed deduction for diagnostics. 5047 (void)Result; 5048 } else { 5049 // FIXME: If the match isn't exact, shouldn't we just drop this as 5050 // a candidate? Find a testcase before changing the code. 5051 assert(FunctionType 5052 == Context.getCanonicalType(Specialization->getType())); 5053 Matches.addDecl(cast<FunctionDecl>(Specialization->getCanonicalDecl()), 5054 I.getAccess()); 5055 } 5056 5057 continue; 5058 } 5059 5060 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 5061 // Skip non-static functions when converting to pointer, and static 5062 // when converting to member pointer. 5063 if (Method->isStatic() == IsMember) 5064 continue; 5065 5066 // If we have explicit template arguments, skip non-templates. 5067 if (OvlExpr->hasExplicitTemplateArgs()) 5068 continue; 5069 } else if (IsMember) 5070 continue; 5071 5072 if (FunctionDecl *FunDecl = dyn_cast<FunctionDecl>(Fn)) { 5073 QualType ResultTy; 5074 if (Context.hasSameUnqualifiedType(FunctionType, FunDecl->getType()) || 5075 IsNoReturnConversion(Context, FunDecl->getType(), FunctionType, 5076 ResultTy)) { 5077 Matches.addDecl(cast<FunctionDecl>(FunDecl->getCanonicalDecl()), 5078 I.getAccess()); 5079 FoundNonTemplateFunction = true; 5080 } 5081 } 5082 } 5083 5084 // If there were 0 or 1 matches, we're done. 5085 if (Matches.empty()) 5086 return 0; 5087 else if (Matches.size() == 1) { 5088 FunctionDecl *Result = cast<FunctionDecl>(*Matches.begin()); 5089 MarkDeclarationReferenced(From->getLocStart(), Result); 5090 if (Complain) 5091 CheckUnresolvedAccess(*this, OvlExpr, Result, Matches.begin().getAccess()); 5092 return Result; 5093 } 5094 5095 // C++ [over.over]p4: 5096 // If more than one function is selected, [...] 5097 if (!FoundNonTemplateFunction) { 5098 // [...] and any given function template specialization F1 is 5099 // eliminated if the set contains a second function template 5100 // specialization whose function template is more specialized 5101 // than the function template of F1 according to the partial 5102 // ordering rules of 14.5.5.2. 5103 5104 // The algorithm specified above is quadratic. We instead use a 5105 // two-pass algorithm (similar to the one used to identify the 5106 // best viable function in an overload set) that identifies the 5107 // best function template (if it exists). 5108 5109 UnresolvedSetIterator Result = 5110 getMostSpecialized(Matches.begin(), Matches.end(), 5111 TPOC_Other, From->getLocStart(), 5112 PDiag(), 5113 PDiag(diag::err_addr_ovl_ambiguous) 5114 << Matches[0]->getDeclName(), 5115 PDiag(diag::note_ovl_candidate) 5116 << (unsigned) oc_function_template); 5117 assert(Result != Matches.end() && "no most-specialized template"); 5118 MarkDeclarationReferenced(From->getLocStart(), *Result); 5119 if (Complain) 5120 CheckUnresolvedAccess(*this, OvlExpr, *Result, Result.getAccess()); 5121 return cast<FunctionDecl>(*Result); 5122 } 5123 5124 // [...] any function template specializations in the set are 5125 // eliminated if the set also contains a non-template function, [...] 5126 for (unsigned I = 0, N = Matches.size(); I != N; ) { 5127 if (cast<FunctionDecl>(Matches[I].getDecl())->getPrimaryTemplate() == 0) 5128 ++I; 5129 else { 5130 Matches.erase(I); 5131 --N; 5132 } 5133 } 5134 5135 // [...] After such eliminations, if any, there shall remain exactly one 5136 // selected function. 5137 if (Matches.size() == 1) { 5138 UnresolvedSetIterator Match = Matches.begin(); 5139 MarkDeclarationReferenced(From->getLocStart(), *Match); 5140 if (Complain) 5141 CheckUnresolvedAccess(*this, OvlExpr, *Match, Match.getAccess()); 5142 return cast<FunctionDecl>(*Match); 5143 } 5144 5145 // FIXME: We should probably return the same thing that BestViableFunction 5146 // returns (even if we issue the diagnostics here). 5147 Diag(From->getLocStart(), diag::err_addr_ovl_ambiguous) 5148 << Matches[0]->getDeclName(); 5149 for (UnresolvedSetIterator I = Matches.begin(), 5150 E = Matches.end(); I != E; ++I) 5151 NoteOverloadCandidate(cast<FunctionDecl>(*I)); 5152 return 0; 5153} 5154 5155/// \brief Given an expression that refers to an overloaded function, try to 5156/// resolve that overloaded function expression down to a single function. 5157/// 5158/// This routine can only resolve template-ids that refer to a single function 5159/// template, where that template-id refers to a single template whose template 5160/// arguments are either provided by the template-id or have defaults, 5161/// as described in C++0x [temp.arg.explicit]p3. 5162FunctionDecl *Sema::ResolveSingleFunctionTemplateSpecialization(Expr *From) { 5163 // C++ [over.over]p1: 5164 // [...] [Note: any redundant set of parentheses surrounding the 5165 // overloaded function name is ignored (5.1). ] 5166 // C++ [over.over]p1: 5167 // [...] The overloaded function name can be preceded by the & 5168 // operator. 5169 5170 if (From->getType() != Context.OverloadTy) 5171 return 0; 5172 5173 OverloadExpr *OvlExpr = OverloadExpr::find(From).getPointer(); 5174 5175 // If we didn't actually find any template-ids, we're done. 5176 if (!OvlExpr->hasExplicitTemplateArgs()) 5177 return 0; 5178 5179 TemplateArgumentListInfo ExplicitTemplateArgs; 5180 OvlExpr->getExplicitTemplateArgs().copyInto(ExplicitTemplateArgs); 5181 5182 // Look through all of the overloaded functions, searching for one 5183 // whose type matches exactly. 5184 FunctionDecl *Matched = 0; 5185 for (UnresolvedSetIterator I = OvlExpr->decls_begin(), 5186 E = OvlExpr->decls_end(); I != E; ++I) { 5187 // C++0x [temp.arg.explicit]p3: 5188 // [...] In contexts where deduction is done and fails, or in contexts 5189 // where deduction is not done, if a template argument list is 5190 // specified and it, along with any default template arguments, 5191 // identifies a single function template specialization, then the 5192 // template-id is an lvalue for the function template specialization. 5193 FunctionTemplateDecl *FunctionTemplate = cast<FunctionTemplateDecl>(*I); 5194 5195 // C++ [over.over]p2: 5196 // If the name is a function template, template argument deduction is 5197 // done (14.8.2.2), and if the argument deduction succeeds, the 5198 // resulting template argument list is used to generate a single 5199 // function template specialization, which is added to the set of 5200 // overloaded functions considered. 5201 FunctionDecl *Specialization = 0; 5202 TemplateDeductionInfo Info(Context, OvlExpr->getNameLoc()); 5203 if (TemplateDeductionResult Result 5204 = DeduceTemplateArguments(FunctionTemplate, &ExplicitTemplateArgs, 5205 Specialization, Info)) { 5206 // FIXME: make a note of the failed deduction for diagnostics. 5207 (void)Result; 5208 continue; 5209 } 5210 5211 // Multiple matches; we can't resolve to a single declaration. 5212 if (Matched) 5213 return 0; 5214 5215 Matched = Specialization; 5216 } 5217 5218 return Matched; 5219} 5220 5221/// \brief Add a single candidate to the overload set. 5222static void AddOverloadedCallCandidate(Sema &S, 5223 NamedDecl *Callee, 5224 AccessSpecifier Access, 5225 const TemplateArgumentListInfo *ExplicitTemplateArgs, 5226 Expr **Args, unsigned NumArgs, 5227 OverloadCandidateSet &CandidateSet, 5228 bool PartialOverloading) { 5229 if (isa<UsingShadowDecl>(Callee)) 5230 Callee = cast<UsingShadowDecl>(Callee)->getTargetDecl(); 5231 5232 if (FunctionDecl *Func = dyn_cast<FunctionDecl>(Callee)) { 5233 assert(!ExplicitTemplateArgs && "Explicit template arguments?"); 5234 S.AddOverloadCandidate(Func, Access, Args, NumArgs, CandidateSet, 5235 false, false, PartialOverloading); 5236 return; 5237 } 5238 5239 if (FunctionTemplateDecl *FuncTemplate 5240 = dyn_cast<FunctionTemplateDecl>(Callee)) { 5241 S.AddTemplateOverloadCandidate(FuncTemplate, Access, ExplicitTemplateArgs, 5242 Args, NumArgs, CandidateSet); 5243 return; 5244 } 5245 5246 assert(false && "unhandled case in overloaded call candidate"); 5247 5248 // do nothing? 5249} 5250 5251/// \brief Add the overload candidates named by callee and/or found by argument 5252/// dependent lookup to the given overload set. 5253void Sema::AddOverloadedCallCandidates(UnresolvedLookupExpr *ULE, 5254 Expr **Args, unsigned NumArgs, 5255 OverloadCandidateSet &CandidateSet, 5256 bool PartialOverloading) { 5257 5258#ifndef NDEBUG 5259 // Verify that ArgumentDependentLookup is consistent with the rules 5260 // in C++0x [basic.lookup.argdep]p3: 5261 // 5262 // Let X be the lookup set produced by unqualified lookup (3.4.1) 5263 // and let Y be the lookup set produced by argument dependent 5264 // lookup (defined as follows). If X contains 5265 // 5266 // -- a declaration of a class member, or 5267 // 5268 // -- a block-scope function declaration that is not a 5269 // using-declaration, or 5270 // 5271 // -- a declaration that is neither a function or a function 5272 // template 5273 // 5274 // then Y is empty. 5275 5276 if (ULE->requiresADL()) { 5277 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(), 5278 E = ULE->decls_end(); I != E; ++I) { 5279 assert(!(*I)->getDeclContext()->isRecord()); 5280 assert(isa<UsingShadowDecl>(*I) || 5281 !(*I)->getDeclContext()->isFunctionOrMethod()); 5282 assert((*I)->getUnderlyingDecl()->isFunctionOrFunctionTemplate()); 5283 } 5284 } 5285#endif 5286 5287 // It would be nice to avoid this copy. 5288 TemplateArgumentListInfo TABuffer; 5289 const TemplateArgumentListInfo *ExplicitTemplateArgs = 0; 5290 if (ULE->hasExplicitTemplateArgs()) { 5291 ULE->copyTemplateArgumentsInto(TABuffer); 5292 ExplicitTemplateArgs = &TABuffer; 5293 } 5294 5295 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(), 5296 E = ULE->decls_end(); I != E; ++I) 5297 AddOverloadedCallCandidate(*this, *I, I.getAccess(), ExplicitTemplateArgs, 5298 Args, NumArgs, CandidateSet, 5299 PartialOverloading); 5300 5301 if (ULE->requiresADL()) 5302 AddArgumentDependentLookupCandidates(ULE->getName(), /*Operator*/ false, 5303 Args, NumArgs, 5304 ExplicitTemplateArgs, 5305 CandidateSet, 5306 PartialOverloading); 5307} 5308 5309static Sema::OwningExprResult Destroy(Sema &SemaRef, Expr *Fn, 5310 Expr **Args, unsigned NumArgs) { 5311 Fn->Destroy(SemaRef.Context); 5312 for (unsigned Arg = 0; Arg < NumArgs; ++Arg) 5313 Args[Arg]->Destroy(SemaRef.Context); 5314 return SemaRef.ExprError(); 5315} 5316 5317/// Attempts to recover from a call where no functions were found. 5318/// 5319/// Returns true if new candidates were found. 5320static Sema::OwningExprResult 5321BuildRecoveryCallExpr(Sema &SemaRef, Expr *Fn, 5322 UnresolvedLookupExpr *ULE, 5323 SourceLocation LParenLoc, 5324 Expr **Args, unsigned NumArgs, 5325 SourceLocation *CommaLocs, 5326 SourceLocation RParenLoc) { 5327 5328 CXXScopeSpec SS; 5329 if (ULE->getQualifier()) { 5330 SS.setScopeRep(ULE->getQualifier()); 5331 SS.setRange(ULE->getQualifierRange()); 5332 } 5333 5334 TemplateArgumentListInfo TABuffer; 5335 const TemplateArgumentListInfo *ExplicitTemplateArgs = 0; 5336 if (ULE->hasExplicitTemplateArgs()) { 5337 ULE->copyTemplateArgumentsInto(TABuffer); 5338 ExplicitTemplateArgs = &TABuffer; 5339 } 5340 5341 LookupResult R(SemaRef, ULE->getName(), ULE->getNameLoc(), 5342 Sema::LookupOrdinaryName); 5343 if (SemaRef.DiagnoseEmptyLookup(/*Scope=*/0, SS, R)) 5344 return Destroy(SemaRef, Fn, Args, NumArgs); 5345 5346 assert(!R.empty() && "lookup results empty despite recovery"); 5347 5348 // Build an implicit member call if appropriate. Just drop the 5349 // casts and such from the call, we don't really care. 5350 Sema::OwningExprResult NewFn = SemaRef.ExprError(); 5351 if ((*R.begin())->isCXXClassMember()) 5352 NewFn = SemaRef.BuildPossibleImplicitMemberExpr(SS, R, ExplicitTemplateArgs); 5353 else if (ExplicitTemplateArgs) 5354 NewFn = SemaRef.BuildTemplateIdExpr(SS, R, false, *ExplicitTemplateArgs); 5355 else 5356 NewFn = SemaRef.BuildDeclarationNameExpr(SS, R, false); 5357 5358 if (NewFn.isInvalid()) 5359 return Destroy(SemaRef, Fn, Args, NumArgs); 5360 5361 Fn->Destroy(SemaRef.Context); 5362 5363 // This shouldn't cause an infinite loop because we're giving it 5364 // an expression with non-empty lookup results, which should never 5365 // end up here. 5366 return SemaRef.ActOnCallExpr(/*Scope*/ 0, move(NewFn), LParenLoc, 5367 Sema::MultiExprArg(SemaRef, (void**) Args, NumArgs), 5368 CommaLocs, RParenLoc); 5369} 5370 5371/// ResolveOverloadedCallFn - Given the call expression that calls Fn 5372/// (which eventually refers to the declaration Func) and the call 5373/// arguments Args/NumArgs, attempt to resolve the function call down 5374/// to a specific function. If overload resolution succeeds, returns 5375/// the function declaration produced by overload 5376/// resolution. Otherwise, emits diagnostics, deletes all of the 5377/// arguments and Fn, and returns NULL. 5378Sema::OwningExprResult 5379Sema::BuildOverloadedCallExpr(Expr *Fn, UnresolvedLookupExpr *ULE, 5380 SourceLocation LParenLoc, 5381 Expr **Args, unsigned NumArgs, 5382 SourceLocation *CommaLocs, 5383 SourceLocation RParenLoc) { 5384#ifndef NDEBUG 5385 if (ULE->requiresADL()) { 5386 // To do ADL, we must have found an unqualified name. 5387 assert(!ULE->getQualifier() && "qualified name with ADL"); 5388 5389 // We don't perform ADL for implicit declarations of builtins. 5390 // Verify that this was correctly set up. 5391 FunctionDecl *F; 5392 if (ULE->decls_begin() + 1 == ULE->decls_end() && 5393 (F = dyn_cast<FunctionDecl>(*ULE->decls_begin())) && 5394 F->getBuiltinID() && F->isImplicit()) 5395 assert(0 && "performing ADL for builtin"); 5396 5397 // We don't perform ADL in C. 5398 assert(getLangOptions().CPlusPlus && "ADL enabled in C"); 5399 } 5400#endif 5401 5402 OverloadCandidateSet CandidateSet(Fn->getExprLoc()); 5403 5404 // Add the functions denoted by the callee to the set of candidate 5405 // functions, including those from argument-dependent lookup. 5406 AddOverloadedCallCandidates(ULE, Args, NumArgs, CandidateSet); 5407 5408 // If we found nothing, try to recover. 5409 // AddRecoveryCallCandidates diagnoses the error itself, so we just 5410 // bailout out if it fails. 5411 if (CandidateSet.empty()) 5412 return BuildRecoveryCallExpr(*this, Fn, ULE, LParenLoc, Args, NumArgs, 5413 CommaLocs, RParenLoc); 5414 5415 OverloadCandidateSet::iterator Best; 5416 switch (BestViableFunction(CandidateSet, Fn->getLocStart(), Best)) { 5417 case OR_Success: { 5418 FunctionDecl *FDecl = Best->Function; 5419 CheckUnresolvedLookupAccess(ULE, FDecl, Best->getAccess()); 5420 Fn = FixOverloadedFunctionReference(Fn, FDecl); 5421 return BuildResolvedCallExpr(Fn, FDecl, LParenLoc, Args, NumArgs, RParenLoc); 5422 } 5423 5424 case OR_No_Viable_Function: 5425 Diag(Fn->getSourceRange().getBegin(), 5426 diag::err_ovl_no_viable_function_in_call) 5427 << ULE->getName() << Fn->getSourceRange(); 5428 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 5429 break; 5430 5431 case OR_Ambiguous: 5432 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_ambiguous_call) 5433 << ULE->getName() << Fn->getSourceRange(); 5434 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, NumArgs); 5435 break; 5436 5437 case OR_Deleted: 5438 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_deleted_call) 5439 << Best->Function->isDeleted() 5440 << ULE->getName() 5441 << Fn->getSourceRange(); 5442 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 5443 break; 5444 } 5445 5446 // Overload resolution failed. Destroy all of the subexpressions and 5447 // return NULL. 5448 Fn->Destroy(Context); 5449 for (unsigned Arg = 0; Arg < NumArgs; ++Arg) 5450 Args[Arg]->Destroy(Context); 5451 return ExprError(); 5452} 5453 5454static bool IsOverloaded(const UnresolvedSetImpl &Functions) { 5455 return Functions.size() > 1 || 5456 (Functions.size() == 1 && isa<FunctionTemplateDecl>(*Functions.begin())); 5457} 5458 5459/// \brief Create a unary operation that may resolve to an overloaded 5460/// operator. 5461/// 5462/// \param OpLoc The location of the operator itself (e.g., '*'). 5463/// 5464/// \param OpcIn The UnaryOperator::Opcode that describes this 5465/// operator. 5466/// 5467/// \param Functions The set of non-member functions that will be 5468/// considered by overload resolution. The caller needs to build this 5469/// set based on the context using, e.g., 5470/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 5471/// set should not contain any member functions; those will be added 5472/// by CreateOverloadedUnaryOp(). 5473/// 5474/// \param input The input argument. 5475Sema::OwningExprResult 5476Sema::CreateOverloadedUnaryOp(SourceLocation OpLoc, unsigned OpcIn, 5477 const UnresolvedSetImpl &Fns, 5478 ExprArg input) { 5479 UnaryOperator::Opcode Opc = static_cast<UnaryOperator::Opcode>(OpcIn); 5480 Expr *Input = (Expr *)input.get(); 5481 5482 OverloadedOperatorKind Op = UnaryOperator::getOverloadedOperator(Opc); 5483 assert(Op != OO_None && "Invalid opcode for overloaded unary operator"); 5484 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 5485 5486 Expr *Args[2] = { Input, 0 }; 5487 unsigned NumArgs = 1; 5488 5489 // For post-increment and post-decrement, add the implicit '0' as 5490 // the second argument, so that we know this is a post-increment or 5491 // post-decrement. 5492 if (Opc == UnaryOperator::PostInc || Opc == UnaryOperator::PostDec) { 5493 llvm::APSInt Zero(Context.getTypeSize(Context.IntTy), false); 5494 Args[1] = new (Context) IntegerLiteral(Zero, Context.IntTy, 5495 SourceLocation()); 5496 NumArgs = 2; 5497 } 5498 5499 if (Input->isTypeDependent()) { 5500 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 5501 UnresolvedLookupExpr *Fn 5502 = UnresolvedLookupExpr::Create(Context, /*Dependent*/ true, NamingClass, 5503 0, SourceRange(), OpName, OpLoc, 5504 /*ADL*/ true, IsOverloaded(Fns)); 5505 Fn->addDecls(Fns.begin(), Fns.end()); 5506 5507 input.release(); 5508 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 5509 &Args[0], NumArgs, 5510 Context.DependentTy, 5511 OpLoc)); 5512 } 5513 5514 // Build an empty overload set. 5515 OverloadCandidateSet CandidateSet(OpLoc); 5516 5517 // Add the candidates from the given function set. 5518 AddFunctionCandidates(Fns, &Args[0], NumArgs, CandidateSet, false); 5519 5520 // Add operator candidates that are member functions. 5521 AddMemberOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 5522 5523 // Add candidates from ADL. 5524 AddArgumentDependentLookupCandidates(OpName, /*Operator*/ true, 5525 Args, NumArgs, 5526 /*ExplicitTemplateArgs*/ 0, 5527 CandidateSet); 5528 5529 // Add builtin operator candidates. 5530 AddBuiltinOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 5531 5532 // Perform overload resolution. 5533 OverloadCandidateSet::iterator Best; 5534 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 5535 case OR_Success: { 5536 // We found a built-in operator or an overloaded operator. 5537 FunctionDecl *FnDecl = Best->Function; 5538 5539 if (FnDecl) { 5540 // We matched an overloaded operator. Build a call to that 5541 // operator. 5542 5543 // Convert the arguments. 5544 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 5545 CheckMemberOperatorAccess(OpLoc, Args[0], Method, Best->getAccess()); 5546 5547 if (PerformObjectArgumentInitialization(Input, /*Qualifier=*/0, Method)) 5548 return ExprError(); 5549 } else { 5550 // Convert the arguments. 5551 OwningExprResult InputInit 5552 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 5553 FnDecl->getParamDecl(0)), 5554 SourceLocation(), 5555 move(input)); 5556 if (InputInit.isInvalid()) 5557 return ExprError(); 5558 5559 input = move(InputInit); 5560 Input = (Expr *)input.get(); 5561 } 5562 5563 // Determine the result type 5564 QualType ResultTy = FnDecl->getResultType().getNonReferenceType(); 5565 5566 // Build the actual expression node. 5567 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 5568 SourceLocation()); 5569 UsualUnaryConversions(FnExpr); 5570 5571 input.release(); 5572 Args[0] = Input; 5573 ExprOwningPtr<CallExpr> TheCall(this, 5574 new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 5575 Args, NumArgs, ResultTy, OpLoc)); 5576 5577 if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall.get(), 5578 FnDecl)) 5579 return ExprError(); 5580 5581 return MaybeBindToTemporary(TheCall.release()); 5582 } else { 5583 // We matched a built-in operator. Convert the arguments, then 5584 // break out so that we will build the appropriate built-in 5585 // operator node. 5586 if (PerformImplicitConversion(Input, Best->BuiltinTypes.ParamTypes[0], 5587 Best->Conversions[0], AA_Passing)) 5588 return ExprError(); 5589 5590 break; 5591 } 5592 } 5593 5594 case OR_No_Viable_Function: 5595 // No viable function; fall through to handling this as a 5596 // built-in operator, which will produce an error message for us. 5597 break; 5598 5599 case OR_Ambiguous: 5600 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 5601 << UnaryOperator::getOpcodeStr(Opc) 5602 << Input->getSourceRange(); 5603 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, NumArgs, 5604 UnaryOperator::getOpcodeStr(Opc), OpLoc); 5605 return ExprError(); 5606 5607 case OR_Deleted: 5608 Diag(OpLoc, diag::err_ovl_deleted_oper) 5609 << Best->Function->isDeleted() 5610 << UnaryOperator::getOpcodeStr(Opc) 5611 << Input->getSourceRange(); 5612 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 5613 return ExprError(); 5614 } 5615 5616 // Either we found no viable overloaded operator or we matched a 5617 // built-in operator. In either case, fall through to trying to 5618 // build a built-in operation. 5619 input.release(); 5620 return CreateBuiltinUnaryOp(OpLoc, Opc, Owned(Input)); 5621} 5622 5623/// \brief Create a binary operation that may resolve to an overloaded 5624/// operator. 5625/// 5626/// \param OpLoc The location of the operator itself (e.g., '+'). 5627/// 5628/// \param OpcIn The BinaryOperator::Opcode that describes this 5629/// operator. 5630/// 5631/// \param Functions The set of non-member functions that will be 5632/// considered by overload resolution. The caller needs to build this 5633/// set based on the context using, e.g., 5634/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 5635/// set should not contain any member functions; those will be added 5636/// by CreateOverloadedBinOp(). 5637/// 5638/// \param LHS Left-hand argument. 5639/// \param RHS Right-hand argument. 5640Sema::OwningExprResult 5641Sema::CreateOverloadedBinOp(SourceLocation OpLoc, 5642 unsigned OpcIn, 5643 const UnresolvedSetImpl &Fns, 5644 Expr *LHS, Expr *RHS) { 5645 Expr *Args[2] = { LHS, RHS }; 5646 LHS=RHS=0; //Please use only Args instead of LHS/RHS couple 5647 5648 BinaryOperator::Opcode Opc = static_cast<BinaryOperator::Opcode>(OpcIn); 5649 OverloadedOperatorKind Op = BinaryOperator::getOverloadedOperator(Opc); 5650 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 5651 5652 // If either side is type-dependent, create an appropriate dependent 5653 // expression. 5654 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 5655 if (Fns.empty()) { 5656 // If there are no functions to store, just build a dependent 5657 // BinaryOperator or CompoundAssignment. 5658 if (Opc <= BinaryOperator::Assign || Opc > BinaryOperator::OrAssign) 5659 return Owned(new (Context) BinaryOperator(Args[0], Args[1], Opc, 5660 Context.DependentTy, OpLoc)); 5661 5662 return Owned(new (Context) CompoundAssignOperator(Args[0], Args[1], Opc, 5663 Context.DependentTy, 5664 Context.DependentTy, 5665 Context.DependentTy, 5666 OpLoc)); 5667 } 5668 5669 // FIXME: save results of ADL from here? 5670 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 5671 UnresolvedLookupExpr *Fn 5672 = UnresolvedLookupExpr::Create(Context, /*Dependent*/ true, NamingClass, 5673 0, SourceRange(), OpName, OpLoc, 5674 /*ADL*/ true, IsOverloaded(Fns)); 5675 5676 Fn->addDecls(Fns.begin(), Fns.end()); 5677 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 5678 Args, 2, 5679 Context.DependentTy, 5680 OpLoc)); 5681 } 5682 5683 // If this is the .* operator, which is not overloadable, just 5684 // create a built-in binary operator. 5685 if (Opc == BinaryOperator::PtrMemD) 5686 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 5687 5688 // If this is the assignment operator, we only perform overload resolution 5689 // if the left-hand side is a class or enumeration type. This is actually 5690 // a hack. The standard requires that we do overload resolution between the 5691 // various built-in candidates, but as DR507 points out, this can lead to 5692 // problems. So we do it this way, which pretty much follows what GCC does. 5693 // Note that we go the traditional code path for compound assignment forms. 5694 if (Opc==BinaryOperator::Assign && !Args[0]->getType()->isOverloadableType()) 5695 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 5696 5697 // Build an empty overload set. 5698 OverloadCandidateSet CandidateSet(OpLoc); 5699 5700 // Add the candidates from the given function set. 5701 AddFunctionCandidates(Fns, Args, 2, CandidateSet, false); 5702 5703 // Add operator candidates that are member functions. 5704 AddMemberOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 5705 5706 // Add candidates from ADL. 5707 AddArgumentDependentLookupCandidates(OpName, /*Operator*/ true, 5708 Args, 2, 5709 /*ExplicitTemplateArgs*/ 0, 5710 CandidateSet); 5711 5712 // Add builtin operator candidates. 5713 AddBuiltinOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 5714 5715 // Perform overload resolution. 5716 OverloadCandidateSet::iterator Best; 5717 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 5718 case OR_Success: { 5719 // We found a built-in operator or an overloaded operator. 5720 FunctionDecl *FnDecl = Best->Function; 5721 5722 if (FnDecl) { 5723 // We matched an overloaded operator. Build a call to that 5724 // operator. 5725 5726 // Convert the arguments. 5727 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 5728 // Best->Access is only meaningful for class members. 5729 CheckMemberOperatorAccess(OpLoc, Args[0], Method, Best->getAccess()); 5730 5731 OwningExprResult Arg1 5732 = PerformCopyInitialization( 5733 InitializedEntity::InitializeParameter( 5734 FnDecl->getParamDecl(0)), 5735 SourceLocation(), 5736 Owned(Args[1])); 5737 if (Arg1.isInvalid()) 5738 return ExprError(); 5739 5740 if (PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/0, 5741 Method)) 5742 return ExprError(); 5743 5744 Args[1] = RHS = Arg1.takeAs<Expr>(); 5745 } else { 5746 // Convert the arguments. 5747 OwningExprResult Arg0 5748 = PerformCopyInitialization( 5749 InitializedEntity::InitializeParameter( 5750 FnDecl->getParamDecl(0)), 5751 SourceLocation(), 5752 Owned(Args[0])); 5753 if (Arg0.isInvalid()) 5754 return ExprError(); 5755 5756 OwningExprResult Arg1 5757 = PerformCopyInitialization( 5758 InitializedEntity::InitializeParameter( 5759 FnDecl->getParamDecl(1)), 5760 SourceLocation(), 5761 Owned(Args[1])); 5762 if (Arg1.isInvalid()) 5763 return ExprError(); 5764 Args[0] = LHS = Arg0.takeAs<Expr>(); 5765 Args[1] = RHS = Arg1.takeAs<Expr>(); 5766 } 5767 5768 // Determine the result type 5769 QualType ResultTy 5770 = FnDecl->getType()->getAs<FunctionType>()->getResultType(); 5771 ResultTy = ResultTy.getNonReferenceType(); 5772 5773 // Build the actual expression node. 5774 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 5775 OpLoc); 5776 UsualUnaryConversions(FnExpr); 5777 5778 ExprOwningPtr<CXXOperatorCallExpr> 5779 TheCall(this, new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 5780 Args, 2, ResultTy, 5781 OpLoc)); 5782 5783 if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall.get(), 5784 FnDecl)) 5785 return ExprError(); 5786 5787 return MaybeBindToTemporary(TheCall.release()); 5788 } else { 5789 // We matched a built-in operator. Convert the arguments, then 5790 // break out so that we will build the appropriate built-in 5791 // operator node. 5792 if (PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 5793 Best->Conversions[0], AA_Passing) || 5794 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 5795 Best->Conversions[1], AA_Passing)) 5796 return ExprError(); 5797 5798 break; 5799 } 5800 } 5801 5802 case OR_No_Viable_Function: { 5803 // C++ [over.match.oper]p9: 5804 // If the operator is the operator , [...] and there are no 5805 // viable functions, then the operator is assumed to be the 5806 // built-in operator and interpreted according to clause 5. 5807 if (Opc == BinaryOperator::Comma) 5808 break; 5809 5810 // For class as left operand for assignment or compound assigment operator 5811 // do not fall through to handling in built-in, but report that no overloaded 5812 // assignment operator found 5813 OwningExprResult Result = ExprError(); 5814 if (Args[0]->getType()->isRecordType() && 5815 Opc >= BinaryOperator::Assign && Opc <= BinaryOperator::OrAssign) { 5816 Diag(OpLoc, diag::err_ovl_no_viable_oper) 5817 << BinaryOperator::getOpcodeStr(Opc) 5818 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 5819 } else { 5820 // No viable function; try to create a built-in operation, which will 5821 // produce an error. Then, show the non-viable candidates. 5822 Result = CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 5823 } 5824 assert(Result.isInvalid() && 5825 "C++ binary operator overloading is missing candidates!"); 5826 if (Result.isInvalid()) 5827 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2, 5828 BinaryOperator::getOpcodeStr(Opc), OpLoc); 5829 return move(Result); 5830 } 5831 5832 case OR_Ambiguous: 5833 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 5834 << BinaryOperator::getOpcodeStr(Opc) 5835 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 5836 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, 2, 5837 BinaryOperator::getOpcodeStr(Opc), OpLoc); 5838 return ExprError(); 5839 5840 case OR_Deleted: 5841 Diag(OpLoc, diag::err_ovl_deleted_oper) 5842 << Best->Function->isDeleted() 5843 << BinaryOperator::getOpcodeStr(Opc) 5844 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 5845 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2); 5846 return ExprError(); 5847 } 5848 5849 // We matched a built-in operator; build it. 5850 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 5851} 5852 5853Action::OwningExprResult 5854Sema::CreateOverloadedArraySubscriptExpr(SourceLocation LLoc, 5855 SourceLocation RLoc, 5856 ExprArg Base, ExprArg Idx) { 5857 Expr *Args[2] = { static_cast<Expr*>(Base.get()), 5858 static_cast<Expr*>(Idx.get()) }; 5859 DeclarationName OpName = 5860 Context.DeclarationNames.getCXXOperatorName(OO_Subscript); 5861 5862 // If either side is type-dependent, create an appropriate dependent 5863 // expression. 5864 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 5865 5866 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 5867 UnresolvedLookupExpr *Fn 5868 = UnresolvedLookupExpr::Create(Context, /*Dependent*/ true, NamingClass, 5869 0, SourceRange(), OpName, LLoc, 5870 /*ADL*/ true, /*Overloaded*/ false); 5871 // Can't add any actual overloads yet 5872 5873 Base.release(); 5874 Idx.release(); 5875 return Owned(new (Context) CXXOperatorCallExpr(Context, OO_Subscript, Fn, 5876 Args, 2, 5877 Context.DependentTy, 5878 RLoc)); 5879 } 5880 5881 // Build an empty overload set. 5882 OverloadCandidateSet CandidateSet(LLoc); 5883 5884 // Subscript can only be overloaded as a member function. 5885 5886 // Add operator candidates that are member functions. 5887 AddMemberOperatorCandidates(OO_Subscript, LLoc, Args, 2, CandidateSet); 5888 5889 // Add builtin operator candidates. 5890 AddBuiltinOperatorCandidates(OO_Subscript, LLoc, Args, 2, CandidateSet); 5891 5892 // Perform overload resolution. 5893 OverloadCandidateSet::iterator Best; 5894 switch (BestViableFunction(CandidateSet, LLoc, Best)) { 5895 case OR_Success: { 5896 // We found a built-in operator or an overloaded operator. 5897 FunctionDecl *FnDecl = Best->Function; 5898 5899 if (FnDecl) { 5900 // We matched an overloaded operator. Build a call to that 5901 // operator. 5902 5903 CheckMemberOperatorAccess(LLoc, Args[0], FnDecl, Best->getAccess()); 5904 5905 // Convert the arguments. 5906 CXXMethodDecl *Method = cast<CXXMethodDecl>(FnDecl); 5907 if (PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/0, 5908 Method)) 5909 return ExprError(); 5910 5911 // Convert the arguments. 5912 OwningExprResult InputInit 5913 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 5914 FnDecl->getParamDecl(0)), 5915 SourceLocation(), 5916 Owned(Args[1])); 5917 if (InputInit.isInvalid()) 5918 return ExprError(); 5919 5920 Args[1] = InputInit.takeAs<Expr>(); 5921 5922 // Determine the result type 5923 QualType ResultTy 5924 = FnDecl->getType()->getAs<FunctionType>()->getResultType(); 5925 ResultTy = ResultTy.getNonReferenceType(); 5926 5927 // Build the actual expression node. 5928 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 5929 LLoc); 5930 UsualUnaryConversions(FnExpr); 5931 5932 Base.release(); 5933 Idx.release(); 5934 ExprOwningPtr<CXXOperatorCallExpr> 5935 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Subscript, 5936 FnExpr, Args, 2, 5937 ResultTy, RLoc)); 5938 5939 if (CheckCallReturnType(FnDecl->getResultType(), LLoc, TheCall.get(), 5940 FnDecl)) 5941 return ExprError(); 5942 5943 return MaybeBindToTemporary(TheCall.release()); 5944 } else { 5945 // We matched a built-in operator. Convert the arguments, then 5946 // break out so that we will build the appropriate built-in 5947 // operator node. 5948 if (PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 5949 Best->Conversions[0], AA_Passing) || 5950 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 5951 Best->Conversions[1], AA_Passing)) 5952 return ExprError(); 5953 5954 break; 5955 } 5956 } 5957 5958 case OR_No_Viable_Function: { 5959 if (CandidateSet.empty()) 5960 Diag(LLoc, diag::err_ovl_no_oper) 5961 << Args[0]->getType() << /*subscript*/ 0 5962 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 5963 else 5964 Diag(LLoc, diag::err_ovl_no_viable_subscript) 5965 << Args[0]->getType() 5966 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 5967 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2, 5968 "[]", LLoc); 5969 return ExprError(); 5970 } 5971 5972 case OR_Ambiguous: 5973 Diag(LLoc, diag::err_ovl_ambiguous_oper) 5974 << "[]" << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 5975 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, 2, 5976 "[]", LLoc); 5977 return ExprError(); 5978 5979 case OR_Deleted: 5980 Diag(LLoc, diag::err_ovl_deleted_oper) 5981 << Best->Function->isDeleted() << "[]" 5982 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 5983 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2, 5984 "[]", LLoc); 5985 return ExprError(); 5986 } 5987 5988 // We matched a built-in operator; build it. 5989 Base.release(); 5990 Idx.release(); 5991 return CreateBuiltinArraySubscriptExpr(Owned(Args[0]), LLoc, 5992 Owned(Args[1]), RLoc); 5993} 5994 5995/// BuildCallToMemberFunction - Build a call to a member 5996/// function. MemExpr is the expression that refers to the member 5997/// function (and includes the object parameter), Args/NumArgs are the 5998/// arguments to the function call (not including the object 5999/// parameter). The caller needs to validate that the member 6000/// expression refers to a member function or an overloaded member 6001/// function. 6002Sema::OwningExprResult 6003Sema::BuildCallToMemberFunction(Scope *S, Expr *MemExprE, 6004 SourceLocation LParenLoc, Expr **Args, 6005 unsigned NumArgs, SourceLocation *CommaLocs, 6006 SourceLocation RParenLoc) { 6007 // Dig out the member expression. This holds both the object 6008 // argument and the member function we're referring to. 6009 Expr *NakedMemExpr = MemExprE->IgnoreParens(); 6010 6011 MemberExpr *MemExpr; 6012 CXXMethodDecl *Method = 0; 6013 NestedNameSpecifier *Qualifier = 0; 6014 if (isa<MemberExpr>(NakedMemExpr)) { 6015 MemExpr = cast<MemberExpr>(NakedMemExpr); 6016 Method = cast<CXXMethodDecl>(MemExpr->getMemberDecl()); 6017 Qualifier = MemExpr->getQualifier(); 6018 } else { 6019 UnresolvedMemberExpr *UnresExpr = cast<UnresolvedMemberExpr>(NakedMemExpr); 6020 Qualifier = UnresExpr->getQualifier(); 6021 6022 QualType ObjectType = UnresExpr->getBaseType(); 6023 6024 // Add overload candidates 6025 OverloadCandidateSet CandidateSet(UnresExpr->getMemberLoc()); 6026 6027 // FIXME: avoid copy. 6028 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 6029 if (UnresExpr->hasExplicitTemplateArgs()) { 6030 UnresExpr->copyTemplateArgumentsInto(TemplateArgsBuffer); 6031 TemplateArgs = &TemplateArgsBuffer; 6032 } 6033 6034 for (UnresolvedMemberExpr::decls_iterator I = UnresExpr->decls_begin(), 6035 E = UnresExpr->decls_end(); I != E; ++I) { 6036 6037 NamedDecl *Func = *I; 6038 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(Func->getDeclContext()); 6039 if (isa<UsingShadowDecl>(Func)) 6040 Func = cast<UsingShadowDecl>(Func)->getTargetDecl(); 6041 6042 if ((Method = dyn_cast<CXXMethodDecl>(Func))) { 6043 // If explicit template arguments were provided, we can't call a 6044 // non-template member function. 6045 if (TemplateArgs) 6046 continue; 6047 6048 AddMethodCandidate(Method, I.getAccess(), ActingDC, ObjectType, 6049 Args, NumArgs, 6050 CandidateSet, /*SuppressUserConversions=*/false); 6051 } else { 6052 AddMethodTemplateCandidate(cast<FunctionTemplateDecl>(Func), 6053 I.getAccess(), ActingDC, TemplateArgs, 6054 ObjectType, Args, NumArgs, 6055 CandidateSet, 6056 /*SuppressUsedConversions=*/false); 6057 } 6058 } 6059 6060 DeclarationName DeclName = UnresExpr->getMemberName(); 6061 6062 OverloadCandidateSet::iterator Best; 6063 switch (BestViableFunction(CandidateSet, UnresExpr->getLocStart(), Best)) { 6064 case OR_Success: 6065 Method = cast<CXXMethodDecl>(Best->Function); 6066 CheckUnresolvedMemberAccess(UnresExpr, Method, Best->getAccess()); 6067 break; 6068 6069 case OR_No_Viable_Function: 6070 Diag(UnresExpr->getMemberLoc(), 6071 diag::err_ovl_no_viable_member_function_in_call) 6072 << DeclName << MemExprE->getSourceRange(); 6073 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6074 // FIXME: Leaking incoming expressions! 6075 return ExprError(); 6076 6077 case OR_Ambiguous: 6078 Diag(UnresExpr->getMemberLoc(), diag::err_ovl_ambiguous_member_call) 6079 << DeclName << MemExprE->getSourceRange(); 6080 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6081 // FIXME: Leaking incoming expressions! 6082 return ExprError(); 6083 6084 case OR_Deleted: 6085 Diag(UnresExpr->getMemberLoc(), diag::err_ovl_deleted_member_call) 6086 << Best->Function->isDeleted() 6087 << DeclName << MemExprE->getSourceRange(); 6088 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6089 // FIXME: Leaking incoming expressions! 6090 return ExprError(); 6091 } 6092 6093 MemExprE = FixOverloadedFunctionReference(MemExprE, Method); 6094 6095 // If overload resolution picked a static member, build a 6096 // non-member call based on that function. 6097 if (Method->isStatic()) { 6098 return BuildResolvedCallExpr(MemExprE, Method, LParenLoc, 6099 Args, NumArgs, RParenLoc); 6100 } 6101 6102 MemExpr = cast<MemberExpr>(MemExprE->IgnoreParens()); 6103 } 6104 6105 assert(Method && "Member call to something that isn't a method?"); 6106 ExprOwningPtr<CXXMemberCallExpr> 6107 TheCall(this, new (Context) CXXMemberCallExpr(Context, MemExprE, Args, 6108 NumArgs, 6109 Method->getResultType().getNonReferenceType(), 6110 RParenLoc)); 6111 6112 // Check for a valid return type. 6113 if (CheckCallReturnType(Method->getResultType(), MemExpr->getMemberLoc(), 6114 TheCall.get(), Method)) 6115 return ExprError(); 6116 6117 // Convert the object argument (for a non-static member function call). 6118 Expr *ObjectArg = MemExpr->getBase(); 6119 if (!Method->isStatic() && 6120 PerformObjectArgumentInitialization(ObjectArg, Qualifier, Method)) 6121 return ExprError(); 6122 MemExpr->setBase(ObjectArg); 6123 6124 // Convert the rest of the arguments 6125 const FunctionProtoType *Proto = cast<FunctionProtoType>(Method->getType()); 6126 if (ConvertArgumentsForCall(&*TheCall, MemExpr, Method, Proto, Args, NumArgs, 6127 RParenLoc)) 6128 return ExprError(); 6129 6130 if (CheckFunctionCall(Method, TheCall.get())) 6131 return ExprError(); 6132 6133 return MaybeBindToTemporary(TheCall.release()); 6134} 6135 6136/// BuildCallToObjectOfClassType - Build a call to an object of class 6137/// type (C++ [over.call.object]), which can end up invoking an 6138/// overloaded function call operator (@c operator()) or performing a 6139/// user-defined conversion on the object argument. 6140Sema::ExprResult 6141Sema::BuildCallToObjectOfClassType(Scope *S, Expr *Object, 6142 SourceLocation LParenLoc, 6143 Expr **Args, unsigned NumArgs, 6144 SourceLocation *CommaLocs, 6145 SourceLocation RParenLoc) { 6146 assert(Object->getType()->isRecordType() && "Requires object type argument"); 6147 const RecordType *Record = Object->getType()->getAs<RecordType>(); 6148 6149 // C++ [over.call.object]p1: 6150 // If the primary-expression E in the function call syntax 6151 // evaluates to a class object of type "cv T", then the set of 6152 // candidate functions includes at least the function call 6153 // operators of T. The function call operators of T are obtained by 6154 // ordinary lookup of the name operator() in the context of 6155 // (E).operator(). 6156 OverloadCandidateSet CandidateSet(LParenLoc); 6157 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Call); 6158 6159 if (RequireCompleteType(LParenLoc, Object->getType(), 6160 PartialDiagnostic(diag::err_incomplete_object_call) 6161 << Object->getSourceRange())) 6162 return true; 6163 6164 LookupResult R(*this, OpName, LParenLoc, LookupOrdinaryName); 6165 LookupQualifiedName(R, Record->getDecl()); 6166 R.suppressDiagnostics(); 6167 6168 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 6169 Oper != OperEnd; ++Oper) { 6170 AddMethodCandidate(*Oper, Oper.getAccess(), Object->getType(), 6171 Args, NumArgs, CandidateSet, 6172 /*SuppressUserConversions=*/ false); 6173 } 6174 6175 // C++ [over.call.object]p2: 6176 // In addition, for each conversion function declared in T of the 6177 // form 6178 // 6179 // operator conversion-type-id () cv-qualifier; 6180 // 6181 // where cv-qualifier is the same cv-qualification as, or a 6182 // greater cv-qualification than, cv, and where conversion-type-id 6183 // denotes the type "pointer to function of (P1,...,Pn) returning 6184 // R", or the type "reference to pointer to function of 6185 // (P1,...,Pn) returning R", or the type "reference to function 6186 // of (P1,...,Pn) returning R", a surrogate call function [...] 6187 // is also considered as a candidate function. Similarly, 6188 // surrogate call functions are added to the set of candidate 6189 // functions for each conversion function declared in an 6190 // accessible base class provided the function is not hidden 6191 // within T by another intervening declaration. 6192 const UnresolvedSetImpl *Conversions 6193 = cast<CXXRecordDecl>(Record->getDecl())->getVisibleConversionFunctions(); 6194 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 6195 E = Conversions->end(); I != E; ++I) { 6196 NamedDecl *D = *I; 6197 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext()); 6198 if (isa<UsingShadowDecl>(D)) 6199 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 6200 6201 // Skip over templated conversion functions; they aren't 6202 // surrogates. 6203 if (isa<FunctionTemplateDecl>(D)) 6204 continue; 6205 6206 CXXConversionDecl *Conv = cast<CXXConversionDecl>(D); 6207 6208 // Strip the reference type (if any) and then the pointer type (if 6209 // any) to get down to what might be a function type. 6210 QualType ConvType = Conv->getConversionType().getNonReferenceType(); 6211 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 6212 ConvType = ConvPtrType->getPointeeType(); 6213 6214 if (const FunctionProtoType *Proto = ConvType->getAs<FunctionProtoType>()) 6215 AddSurrogateCandidate(Conv, I.getAccess(), ActingContext, Proto, 6216 Object->getType(), Args, NumArgs, 6217 CandidateSet); 6218 } 6219 6220 // Perform overload resolution. 6221 OverloadCandidateSet::iterator Best; 6222 switch (BestViableFunction(CandidateSet, Object->getLocStart(), Best)) { 6223 case OR_Success: 6224 // Overload resolution succeeded; we'll build the appropriate call 6225 // below. 6226 break; 6227 6228 case OR_No_Viable_Function: 6229 if (CandidateSet.empty()) 6230 Diag(Object->getSourceRange().getBegin(), diag::err_ovl_no_oper) 6231 << Object->getType() << /*call*/ 1 6232 << Object->getSourceRange(); 6233 else 6234 Diag(Object->getSourceRange().getBegin(), 6235 diag::err_ovl_no_viable_object_call) 6236 << Object->getType() << Object->getSourceRange(); 6237 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6238 break; 6239 6240 case OR_Ambiguous: 6241 Diag(Object->getSourceRange().getBegin(), 6242 diag::err_ovl_ambiguous_object_call) 6243 << Object->getType() << Object->getSourceRange(); 6244 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, NumArgs); 6245 break; 6246 6247 case OR_Deleted: 6248 Diag(Object->getSourceRange().getBegin(), 6249 diag::err_ovl_deleted_object_call) 6250 << Best->Function->isDeleted() 6251 << Object->getType() << Object->getSourceRange(); 6252 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6253 break; 6254 } 6255 6256 if (Best == CandidateSet.end()) { 6257 // We had an error; delete all of the subexpressions and return 6258 // the error. 6259 Object->Destroy(Context); 6260 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 6261 Args[ArgIdx]->Destroy(Context); 6262 return true; 6263 } 6264 6265 if (Best->Function == 0) { 6266 // Since there is no function declaration, this is one of the 6267 // surrogate candidates. Dig out the conversion function. 6268 CXXConversionDecl *Conv 6269 = cast<CXXConversionDecl>( 6270 Best->Conversions[0].UserDefined.ConversionFunction); 6271 6272 CheckMemberOperatorAccess(LParenLoc, Object, Conv, Best->getAccess()); 6273 6274 // We selected one of the surrogate functions that converts the 6275 // object parameter to a function pointer. Perform the conversion 6276 // on the object argument, then let ActOnCallExpr finish the job. 6277 6278 // Create an implicit member expr to refer to the conversion operator. 6279 // and then call it. 6280 CXXMemberCallExpr *CE = BuildCXXMemberCallExpr(Object, Conv); 6281 6282 return ActOnCallExpr(S, ExprArg(*this, CE), LParenLoc, 6283 MultiExprArg(*this, (ExprTy**)Args, NumArgs), 6284 CommaLocs, RParenLoc).release(); 6285 } 6286 6287 CheckMemberOperatorAccess(LParenLoc, Object, 6288 Best->Function, Best->getAccess()); 6289 6290 // We found an overloaded operator(). Build a CXXOperatorCallExpr 6291 // that calls this method, using Object for the implicit object 6292 // parameter and passing along the remaining arguments. 6293 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 6294 const FunctionProtoType *Proto = Method->getType()->getAs<FunctionProtoType>(); 6295 6296 unsigned NumArgsInProto = Proto->getNumArgs(); 6297 unsigned NumArgsToCheck = NumArgs; 6298 6299 // Build the full argument list for the method call (the 6300 // implicit object parameter is placed at the beginning of the 6301 // list). 6302 Expr **MethodArgs; 6303 if (NumArgs < NumArgsInProto) { 6304 NumArgsToCheck = NumArgsInProto; 6305 MethodArgs = new Expr*[NumArgsInProto + 1]; 6306 } else { 6307 MethodArgs = new Expr*[NumArgs + 1]; 6308 } 6309 MethodArgs[0] = Object; 6310 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 6311 MethodArgs[ArgIdx + 1] = Args[ArgIdx]; 6312 6313 Expr *NewFn = new (Context) DeclRefExpr(Method, Method->getType(), 6314 SourceLocation()); 6315 UsualUnaryConversions(NewFn); 6316 6317 // Once we've built TheCall, all of the expressions are properly 6318 // owned. 6319 QualType ResultTy = Method->getResultType().getNonReferenceType(); 6320 ExprOwningPtr<CXXOperatorCallExpr> 6321 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Call, NewFn, 6322 MethodArgs, NumArgs + 1, 6323 ResultTy, RParenLoc)); 6324 delete [] MethodArgs; 6325 6326 if (CheckCallReturnType(Method->getResultType(), LParenLoc, TheCall.get(), 6327 Method)) 6328 return true; 6329 6330 // We may have default arguments. If so, we need to allocate more 6331 // slots in the call for them. 6332 if (NumArgs < NumArgsInProto) 6333 TheCall->setNumArgs(Context, NumArgsInProto + 1); 6334 else if (NumArgs > NumArgsInProto) 6335 NumArgsToCheck = NumArgsInProto; 6336 6337 bool IsError = false; 6338 6339 // Initialize the implicit object parameter. 6340 IsError |= PerformObjectArgumentInitialization(Object, /*Qualifier=*/0, 6341 Method); 6342 TheCall->setArg(0, Object); 6343 6344 6345 // Check the argument types. 6346 for (unsigned i = 0; i != NumArgsToCheck; i++) { 6347 Expr *Arg; 6348 if (i < NumArgs) { 6349 Arg = Args[i]; 6350 6351 // Pass the argument. 6352 6353 OwningExprResult InputInit 6354 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 6355 Method->getParamDecl(i)), 6356 SourceLocation(), Owned(Arg)); 6357 6358 IsError |= InputInit.isInvalid(); 6359 Arg = InputInit.takeAs<Expr>(); 6360 } else { 6361 OwningExprResult DefArg 6362 = BuildCXXDefaultArgExpr(LParenLoc, Method, Method->getParamDecl(i)); 6363 if (DefArg.isInvalid()) { 6364 IsError = true; 6365 break; 6366 } 6367 6368 Arg = DefArg.takeAs<Expr>(); 6369 } 6370 6371 TheCall->setArg(i + 1, Arg); 6372 } 6373 6374 // If this is a variadic call, handle args passed through "...". 6375 if (Proto->isVariadic()) { 6376 // Promote the arguments (C99 6.5.2.2p7). 6377 for (unsigned i = NumArgsInProto; i != NumArgs; i++) { 6378 Expr *Arg = Args[i]; 6379 IsError |= DefaultVariadicArgumentPromotion(Arg, VariadicMethod); 6380 TheCall->setArg(i + 1, Arg); 6381 } 6382 } 6383 6384 if (IsError) return true; 6385 6386 if (CheckFunctionCall(Method, TheCall.get())) 6387 return true; 6388 6389 return MaybeBindToTemporary(TheCall.release()).release(); 6390} 6391 6392/// BuildOverloadedArrowExpr - Build a call to an overloaded @c operator-> 6393/// (if one exists), where @c Base is an expression of class type and 6394/// @c Member is the name of the member we're trying to find. 6395Sema::OwningExprResult 6396Sema::BuildOverloadedArrowExpr(Scope *S, ExprArg BaseIn, SourceLocation OpLoc) { 6397 Expr *Base = static_cast<Expr *>(BaseIn.get()); 6398 assert(Base->getType()->isRecordType() && "left-hand side must have class type"); 6399 6400 SourceLocation Loc = Base->getExprLoc(); 6401 6402 // C++ [over.ref]p1: 6403 // 6404 // [...] An expression x->m is interpreted as (x.operator->())->m 6405 // for a class object x of type T if T::operator->() exists and if 6406 // the operator is selected as the best match function by the 6407 // overload resolution mechanism (13.3). 6408 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Arrow); 6409 OverloadCandidateSet CandidateSet(Loc); 6410 const RecordType *BaseRecord = Base->getType()->getAs<RecordType>(); 6411 6412 if (RequireCompleteType(Loc, Base->getType(), 6413 PDiag(diag::err_typecheck_incomplete_tag) 6414 << Base->getSourceRange())) 6415 return ExprError(); 6416 6417 LookupResult R(*this, OpName, OpLoc, LookupOrdinaryName); 6418 LookupQualifiedName(R, BaseRecord->getDecl()); 6419 R.suppressDiagnostics(); 6420 6421 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 6422 Oper != OperEnd; ++Oper) { 6423 NamedDecl *D = *Oper; 6424 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext()); 6425 if (isa<UsingShadowDecl>(D)) 6426 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 6427 6428 AddMethodCandidate(cast<CXXMethodDecl>(D), Oper.getAccess(), ActingContext, 6429 Base->getType(), 0, 0, CandidateSet, 6430 /*SuppressUserConversions=*/false); 6431 } 6432 6433 // Perform overload resolution. 6434 OverloadCandidateSet::iterator Best; 6435 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 6436 case OR_Success: 6437 // Overload resolution succeeded; we'll build the call below. 6438 break; 6439 6440 case OR_No_Viable_Function: 6441 if (CandidateSet.empty()) 6442 Diag(OpLoc, diag::err_typecheck_member_reference_arrow) 6443 << Base->getType() << Base->getSourceRange(); 6444 else 6445 Diag(OpLoc, diag::err_ovl_no_viable_oper) 6446 << "operator->" << Base->getSourceRange(); 6447 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, &Base, 1); 6448 return ExprError(); 6449 6450 case OR_Ambiguous: 6451 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 6452 << "->" << Base->getSourceRange(); 6453 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, &Base, 1); 6454 return ExprError(); 6455 6456 case OR_Deleted: 6457 Diag(OpLoc, diag::err_ovl_deleted_oper) 6458 << Best->Function->isDeleted() 6459 << "->" << Base->getSourceRange(); 6460 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, &Base, 1); 6461 return ExprError(); 6462 } 6463 6464 // Convert the object parameter. 6465 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 6466 if (PerformObjectArgumentInitialization(Base, /*Qualifier=*/0, Method)) 6467 return ExprError(); 6468 6469 // No concerns about early exits now. 6470 BaseIn.release(); 6471 6472 // Build the operator call. 6473 Expr *FnExpr = new (Context) DeclRefExpr(Method, Method->getType(), 6474 SourceLocation()); 6475 UsualUnaryConversions(FnExpr); 6476 6477 QualType ResultTy = Method->getResultType().getNonReferenceType(); 6478 ExprOwningPtr<CXXOperatorCallExpr> 6479 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Arrow, FnExpr, 6480 &Base, 1, ResultTy, OpLoc)); 6481 6482 if (CheckCallReturnType(Method->getResultType(), OpLoc, TheCall.get(), 6483 Method)) 6484 return ExprError(); 6485 return move(TheCall); 6486} 6487 6488/// FixOverloadedFunctionReference - E is an expression that refers to 6489/// a C++ overloaded function (possibly with some parentheses and 6490/// perhaps a '&' around it). We have resolved the overloaded function 6491/// to the function declaration Fn, so patch up the expression E to 6492/// refer (possibly indirectly) to Fn. Returns the new expr. 6493Expr *Sema::FixOverloadedFunctionReference(Expr *E, FunctionDecl *Fn) { 6494 if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) { 6495 Expr *SubExpr = FixOverloadedFunctionReference(PE->getSubExpr(), Fn); 6496 if (SubExpr == PE->getSubExpr()) 6497 return PE->Retain(); 6498 6499 return new (Context) ParenExpr(PE->getLParen(), PE->getRParen(), SubExpr); 6500 } 6501 6502 if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) { 6503 Expr *SubExpr = FixOverloadedFunctionReference(ICE->getSubExpr(), Fn); 6504 assert(Context.hasSameType(ICE->getSubExpr()->getType(), 6505 SubExpr->getType()) && 6506 "Implicit cast type cannot be determined from overload"); 6507 if (SubExpr == ICE->getSubExpr()) 6508 return ICE->Retain(); 6509 6510 return new (Context) ImplicitCastExpr(ICE->getType(), 6511 ICE->getCastKind(), 6512 SubExpr, 6513 ICE->isLvalueCast()); 6514 } 6515 6516 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(E)) { 6517 assert(UnOp->getOpcode() == UnaryOperator::AddrOf && 6518 "Can only take the address of an overloaded function"); 6519 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 6520 if (Method->isStatic()) { 6521 // Do nothing: static member functions aren't any different 6522 // from non-member functions. 6523 } else { 6524 // Fix the sub expression, which really has to be an 6525 // UnresolvedLookupExpr holding an overloaded member function 6526 // or template. 6527 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(), Fn); 6528 if (SubExpr == UnOp->getSubExpr()) 6529 return UnOp->Retain(); 6530 6531 assert(isa<DeclRefExpr>(SubExpr) 6532 && "fixed to something other than a decl ref"); 6533 assert(cast<DeclRefExpr>(SubExpr)->getQualifier() 6534 && "fixed to a member ref with no nested name qualifier"); 6535 6536 // We have taken the address of a pointer to member 6537 // function. Perform the computation here so that we get the 6538 // appropriate pointer to member type. 6539 QualType ClassType 6540 = Context.getTypeDeclType(cast<RecordDecl>(Method->getDeclContext())); 6541 QualType MemPtrType 6542 = Context.getMemberPointerType(Fn->getType(), ClassType.getTypePtr()); 6543 6544 return new (Context) UnaryOperator(SubExpr, UnaryOperator::AddrOf, 6545 MemPtrType, UnOp->getOperatorLoc()); 6546 } 6547 } 6548 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(), Fn); 6549 if (SubExpr == UnOp->getSubExpr()) 6550 return UnOp->Retain(); 6551 6552 return new (Context) UnaryOperator(SubExpr, UnaryOperator::AddrOf, 6553 Context.getPointerType(SubExpr->getType()), 6554 UnOp->getOperatorLoc()); 6555 } 6556 6557 if (UnresolvedLookupExpr *ULE = dyn_cast<UnresolvedLookupExpr>(E)) { 6558 // FIXME: avoid copy. 6559 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 6560 if (ULE->hasExplicitTemplateArgs()) { 6561 ULE->copyTemplateArgumentsInto(TemplateArgsBuffer); 6562 TemplateArgs = &TemplateArgsBuffer; 6563 } 6564 6565 return DeclRefExpr::Create(Context, 6566 ULE->getQualifier(), 6567 ULE->getQualifierRange(), 6568 Fn, 6569 ULE->getNameLoc(), 6570 Fn->getType(), 6571 TemplateArgs); 6572 } 6573 6574 if (UnresolvedMemberExpr *MemExpr = dyn_cast<UnresolvedMemberExpr>(E)) { 6575 // FIXME: avoid copy. 6576 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 6577 if (MemExpr->hasExplicitTemplateArgs()) { 6578 MemExpr->copyTemplateArgumentsInto(TemplateArgsBuffer); 6579 TemplateArgs = &TemplateArgsBuffer; 6580 } 6581 6582 Expr *Base; 6583 6584 // If we're filling in 6585 if (MemExpr->isImplicitAccess()) { 6586 if (cast<CXXMethodDecl>(Fn)->isStatic()) { 6587 return DeclRefExpr::Create(Context, 6588 MemExpr->getQualifier(), 6589 MemExpr->getQualifierRange(), 6590 Fn, 6591 MemExpr->getMemberLoc(), 6592 Fn->getType(), 6593 TemplateArgs); 6594 } else { 6595 SourceLocation Loc = MemExpr->getMemberLoc(); 6596 if (MemExpr->getQualifier()) 6597 Loc = MemExpr->getQualifierRange().getBegin(); 6598 Base = new (Context) CXXThisExpr(Loc, 6599 MemExpr->getBaseType(), 6600 /*isImplicit=*/true); 6601 } 6602 } else 6603 Base = MemExpr->getBase()->Retain(); 6604 6605 return MemberExpr::Create(Context, Base, 6606 MemExpr->isArrow(), 6607 MemExpr->getQualifier(), 6608 MemExpr->getQualifierRange(), 6609 Fn, 6610 MemExpr->getMemberLoc(), 6611 TemplateArgs, 6612 Fn->getType()); 6613 } 6614 6615 assert(false && "Invalid reference to overloaded function"); 6616 return E->Retain(); 6617} 6618 6619Sema::OwningExprResult Sema::FixOverloadedFunctionReference(OwningExprResult E, 6620 FunctionDecl *Fn) { 6621 return Owned(FixOverloadedFunctionReference((Expr *)E.get(), Fn)); 6622} 6623 6624} // end namespace clang 6625