SemaOverload.cpp revision ee9ca6966d63419e4da1ea54151864a4ed8daeed
1//===--- SemaOverload.cpp - C++ Overloading ---------------------*- C++ -*-===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This file provides Sema routines for C++ overloading. 11// 12//===----------------------------------------------------------------------===// 13 14#include "Sema.h" 15#include "Lookup.h" 16#include "SemaInit.h" 17#include "clang/Basic/Diagnostic.h" 18#include "clang/Lex/Preprocessor.h" 19#include "clang/AST/ASTContext.h" 20#include "clang/AST/CXXInheritance.h" 21#include "clang/AST/Expr.h" 22#include "clang/AST/ExprCXX.h" 23#include "clang/AST/TypeOrdering.h" 24#include "clang/Basic/PartialDiagnostic.h" 25#include "llvm/ADT/SmallPtrSet.h" 26#include "llvm/ADT/STLExtras.h" 27#include <algorithm> 28 29namespace clang { 30 31/// GetConversionCategory - Retrieve the implicit conversion 32/// category corresponding to the given implicit conversion kind. 33ImplicitConversionCategory 34GetConversionCategory(ImplicitConversionKind Kind) { 35 static const ImplicitConversionCategory 36 Category[(int)ICK_Num_Conversion_Kinds] = { 37 ICC_Identity, 38 ICC_Lvalue_Transformation, 39 ICC_Lvalue_Transformation, 40 ICC_Lvalue_Transformation, 41 ICC_Identity, 42 ICC_Qualification_Adjustment, 43 ICC_Promotion, 44 ICC_Promotion, 45 ICC_Promotion, 46 ICC_Conversion, 47 ICC_Conversion, 48 ICC_Conversion, 49 ICC_Conversion, 50 ICC_Conversion, 51 ICC_Conversion, 52 ICC_Conversion, 53 ICC_Conversion, 54 ICC_Conversion, 55 ICC_Conversion 56 }; 57 return Category[(int)Kind]; 58} 59 60/// GetConversionRank - Retrieve the implicit conversion rank 61/// corresponding to the given implicit conversion kind. 62ImplicitConversionRank GetConversionRank(ImplicitConversionKind Kind) { 63 static const ImplicitConversionRank 64 Rank[(int)ICK_Num_Conversion_Kinds] = { 65 ICR_Exact_Match, 66 ICR_Exact_Match, 67 ICR_Exact_Match, 68 ICR_Exact_Match, 69 ICR_Exact_Match, 70 ICR_Exact_Match, 71 ICR_Promotion, 72 ICR_Promotion, 73 ICR_Promotion, 74 ICR_Conversion, 75 ICR_Conversion, 76 ICR_Conversion, 77 ICR_Conversion, 78 ICR_Conversion, 79 ICR_Conversion, 80 ICR_Conversion, 81 ICR_Conversion, 82 ICR_Conversion, 83 ICR_Complex_Real_Conversion 84 }; 85 return Rank[(int)Kind]; 86} 87 88/// GetImplicitConversionName - Return the name of this kind of 89/// implicit conversion. 90const char* GetImplicitConversionName(ImplicitConversionKind Kind) { 91 static const char* const Name[(int)ICK_Num_Conversion_Kinds] = { 92 "No conversion", 93 "Lvalue-to-rvalue", 94 "Array-to-pointer", 95 "Function-to-pointer", 96 "Noreturn adjustment", 97 "Qualification", 98 "Integral promotion", 99 "Floating point promotion", 100 "Complex promotion", 101 "Integral conversion", 102 "Floating conversion", 103 "Complex conversion", 104 "Floating-integral conversion", 105 "Complex-real conversion", 106 "Pointer conversion", 107 "Pointer-to-member conversion", 108 "Boolean conversion", 109 "Compatible-types conversion", 110 "Derived-to-base conversion" 111 }; 112 return Name[Kind]; 113} 114 115/// StandardConversionSequence - Set the standard conversion 116/// sequence to the identity conversion. 117void StandardConversionSequence::setAsIdentityConversion() { 118 First = ICK_Identity; 119 Second = ICK_Identity; 120 Third = ICK_Identity; 121 DeprecatedStringLiteralToCharPtr = false; 122 ReferenceBinding = false; 123 DirectBinding = false; 124 RRefBinding = false; 125 CopyConstructor = 0; 126} 127 128/// getRank - Retrieve the rank of this standard conversion sequence 129/// (C++ 13.3.3.1.1p3). The rank is the largest rank of each of the 130/// implicit conversions. 131ImplicitConversionRank StandardConversionSequence::getRank() const { 132 ImplicitConversionRank Rank = ICR_Exact_Match; 133 if (GetConversionRank(First) > Rank) 134 Rank = GetConversionRank(First); 135 if (GetConversionRank(Second) > Rank) 136 Rank = GetConversionRank(Second); 137 if (GetConversionRank(Third) > Rank) 138 Rank = GetConversionRank(Third); 139 return Rank; 140} 141 142/// isPointerConversionToBool - Determines whether this conversion is 143/// a conversion of a pointer or pointer-to-member to bool. This is 144/// used as part of the ranking of standard conversion sequences 145/// (C++ 13.3.3.2p4). 146bool StandardConversionSequence::isPointerConversionToBool() const { 147 // Note that FromType has not necessarily been transformed by the 148 // array-to-pointer or function-to-pointer implicit conversions, so 149 // check for their presence as well as checking whether FromType is 150 // a pointer. 151 if (getToType(1)->isBooleanType() && 152 (getFromType()->isPointerType() || getFromType()->isBlockPointerType() || 153 First == ICK_Array_To_Pointer || First == ICK_Function_To_Pointer)) 154 return true; 155 156 return false; 157} 158 159/// isPointerConversionToVoidPointer - Determines whether this 160/// conversion is a conversion of a pointer to a void pointer. This is 161/// used as part of the ranking of standard conversion sequences (C++ 162/// 13.3.3.2p4). 163bool 164StandardConversionSequence:: 165isPointerConversionToVoidPointer(ASTContext& Context) const { 166 QualType FromType = getFromType(); 167 QualType ToType = getToType(1); 168 169 // Note that FromType has not necessarily been transformed by the 170 // array-to-pointer implicit conversion, so check for its presence 171 // and redo the conversion to get a pointer. 172 if (First == ICK_Array_To_Pointer) 173 FromType = Context.getArrayDecayedType(FromType); 174 175 if (Second == ICK_Pointer_Conversion && FromType->isPointerType()) 176 if (const PointerType* ToPtrType = ToType->getAs<PointerType>()) 177 return ToPtrType->getPointeeType()->isVoidType(); 178 179 return false; 180} 181 182/// DebugPrint - Print this standard conversion sequence to standard 183/// error. Useful for debugging overloading issues. 184void StandardConversionSequence::DebugPrint() const { 185 llvm::raw_ostream &OS = llvm::errs(); 186 bool PrintedSomething = false; 187 if (First != ICK_Identity) { 188 OS << GetImplicitConversionName(First); 189 PrintedSomething = true; 190 } 191 192 if (Second != ICK_Identity) { 193 if (PrintedSomething) { 194 OS << " -> "; 195 } 196 OS << GetImplicitConversionName(Second); 197 198 if (CopyConstructor) { 199 OS << " (by copy constructor)"; 200 } else if (DirectBinding) { 201 OS << " (direct reference binding)"; 202 } else if (ReferenceBinding) { 203 OS << " (reference binding)"; 204 } 205 PrintedSomething = true; 206 } 207 208 if (Third != ICK_Identity) { 209 if (PrintedSomething) { 210 OS << " -> "; 211 } 212 OS << GetImplicitConversionName(Third); 213 PrintedSomething = true; 214 } 215 216 if (!PrintedSomething) { 217 OS << "No conversions required"; 218 } 219} 220 221/// DebugPrint - Print this user-defined conversion sequence to standard 222/// error. Useful for debugging overloading issues. 223void UserDefinedConversionSequence::DebugPrint() const { 224 llvm::raw_ostream &OS = llvm::errs(); 225 if (Before.First || Before.Second || Before.Third) { 226 Before.DebugPrint(); 227 OS << " -> "; 228 } 229 OS << "'" << ConversionFunction->getNameAsString() << "'"; 230 if (After.First || After.Second || After.Third) { 231 OS << " -> "; 232 After.DebugPrint(); 233 } 234} 235 236/// DebugPrint - Print this implicit conversion sequence to standard 237/// error. Useful for debugging overloading issues. 238void ImplicitConversionSequence::DebugPrint() const { 239 llvm::raw_ostream &OS = llvm::errs(); 240 switch (ConversionKind) { 241 case StandardConversion: 242 OS << "Standard conversion: "; 243 Standard.DebugPrint(); 244 break; 245 case UserDefinedConversion: 246 OS << "User-defined conversion: "; 247 UserDefined.DebugPrint(); 248 break; 249 case EllipsisConversion: 250 OS << "Ellipsis conversion"; 251 break; 252 case AmbiguousConversion: 253 OS << "Ambiguous conversion"; 254 break; 255 case BadConversion: 256 OS << "Bad conversion"; 257 break; 258 } 259 260 OS << "\n"; 261} 262 263void AmbiguousConversionSequence::construct() { 264 new (&conversions()) ConversionSet(); 265} 266 267void AmbiguousConversionSequence::destruct() { 268 conversions().~ConversionSet(); 269} 270 271void 272AmbiguousConversionSequence::copyFrom(const AmbiguousConversionSequence &O) { 273 FromTypePtr = O.FromTypePtr; 274 ToTypePtr = O.ToTypePtr; 275 new (&conversions()) ConversionSet(O.conversions()); 276} 277 278 279// IsOverload - Determine whether the given New declaration is an 280// overload of the declarations in Old. This routine returns false if 281// New and Old cannot be overloaded, e.g., if New has the same 282// signature as some function in Old (C++ 1.3.10) or if the Old 283// declarations aren't functions (or function templates) at all. When 284// it does return false, MatchedDecl will point to the decl that New 285// cannot be overloaded with. This decl may be a UsingShadowDecl on 286// top of the underlying declaration. 287// 288// Example: Given the following input: 289// 290// void f(int, float); // #1 291// void f(int, int); // #2 292// int f(int, int); // #3 293// 294// When we process #1, there is no previous declaration of "f", 295// so IsOverload will not be used. 296// 297// When we process #2, Old contains only the FunctionDecl for #1. By 298// comparing the parameter types, we see that #1 and #2 are overloaded 299// (since they have different signatures), so this routine returns 300// false; MatchedDecl is unchanged. 301// 302// When we process #3, Old is an overload set containing #1 and #2. We 303// compare the signatures of #3 to #1 (they're overloaded, so we do 304// nothing) and then #3 to #2. Since the signatures of #3 and #2 are 305// identical (return types of functions are not part of the 306// signature), IsOverload returns false and MatchedDecl will be set to 307// point to the FunctionDecl for #2. 308Sema::OverloadKind 309Sema::CheckOverload(FunctionDecl *New, const LookupResult &Old, 310 NamedDecl *&Match) { 311 for (LookupResult::iterator I = Old.begin(), E = Old.end(); 312 I != E; ++I) { 313 NamedDecl *OldD = (*I)->getUnderlyingDecl(); 314 if (FunctionTemplateDecl *OldT = dyn_cast<FunctionTemplateDecl>(OldD)) { 315 if (!IsOverload(New, OldT->getTemplatedDecl())) { 316 Match = *I; 317 return Ovl_Match; 318 } 319 } else if (FunctionDecl *OldF = dyn_cast<FunctionDecl>(OldD)) { 320 if (!IsOverload(New, OldF)) { 321 Match = *I; 322 return Ovl_Match; 323 } 324 } else if (isa<UsingDecl>(OldD) || isa<TagDecl>(OldD)) { 325 // We can overload with these, which can show up when doing 326 // redeclaration checks for UsingDecls. 327 assert(Old.getLookupKind() == LookupUsingDeclName); 328 } else if (isa<UnresolvedUsingValueDecl>(OldD)) { 329 // Optimistically assume that an unresolved using decl will 330 // overload; if it doesn't, we'll have to diagnose during 331 // template instantiation. 332 } else { 333 // (C++ 13p1): 334 // Only function declarations can be overloaded; object and type 335 // declarations cannot be overloaded. 336 Match = *I; 337 return Ovl_NonFunction; 338 } 339 } 340 341 return Ovl_Overload; 342} 343 344bool Sema::IsOverload(FunctionDecl *New, FunctionDecl *Old) { 345 FunctionTemplateDecl *OldTemplate = Old->getDescribedFunctionTemplate(); 346 FunctionTemplateDecl *NewTemplate = New->getDescribedFunctionTemplate(); 347 348 // C++ [temp.fct]p2: 349 // A function template can be overloaded with other function templates 350 // and with normal (non-template) functions. 351 if ((OldTemplate == 0) != (NewTemplate == 0)) 352 return true; 353 354 // Is the function New an overload of the function Old? 355 QualType OldQType = Context.getCanonicalType(Old->getType()); 356 QualType NewQType = Context.getCanonicalType(New->getType()); 357 358 // Compare the signatures (C++ 1.3.10) of the two functions to 359 // determine whether they are overloads. If we find any mismatch 360 // in the signature, they are overloads. 361 362 // If either of these functions is a K&R-style function (no 363 // prototype), then we consider them to have matching signatures. 364 if (isa<FunctionNoProtoType>(OldQType.getTypePtr()) || 365 isa<FunctionNoProtoType>(NewQType.getTypePtr())) 366 return false; 367 368 FunctionProtoType* OldType = cast<FunctionProtoType>(OldQType); 369 FunctionProtoType* NewType = cast<FunctionProtoType>(NewQType); 370 371 // The signature of a function includes the types of its 372 // parameters (C++ 1.3.10), which includes the presence or absence 373 // of the ellipsis; see C++ DR 357). 374 if (OldQType != NewQType && 375 (OldType->getNumArgs() != NewType->getNumArgs() || 376 OldType->isVariadic() != NewType->isVariadic() || 377 !std::equal(OldType->arg_type_begin(), OldType->arg_type_end(), 378 NewType->arg_type_begin()))) 379 return true; 380 381 // C++ [temp.over.link]p4: 382 // The signature of a function template consists of its function 383 // signature, its return type and its template parameter list. The names 384 // of the template parameters are significant only for establishing the 385 // relationship between the template parameters and the rest of the 386 // signature. 387 // 388 // We check the return type and template parameter lists for function 389 // templates first; the remaining checks follow. 390 if (NewTemplate && 391 (!TemplateParameterListsAreEqual(NewTemplate->getTemplateParameters(), 392 OldTemplate->getTemplateParameters(), 393 false, TPL_TemplateMatch) || 394 OldType->getResultType() != NewType->getResultType())) 395 return true; 396 397 // If the function is a class member, its signature includes the 398 // cv-qualifiers (if any) on the function itself. 399 // 400 // As part of this, also check whether one of the member functions 401 // is static, in which case they are not overloads (C++ 402 // 13.1p2). While not part of the definition of the signature, 403 // this check is important to determine whether these functions 404 // can be overloaded. 405 CXXMethodDecl* OldMethod = dyn_cast<CXXMethodDecl>(Old); 406 CXXMethodDecl* NewMethod = dyn_cast<CXXMethodDecl>(New); 407 if (OldMethod && NewMethod && 408 !OldMethod->isStatic() && !NewMethod->isStatic() && 409 OldMethod->getTypeQualifiers() != NewMethod->getTypeQualifiers()) 410 return true; 411 412 // The signatures match; this is not an overload. 413 return false; 414} 415 416/// TryImplicitConversion - Attempt to perform an implicit conversion 417/// from the given expression (Expr) to the given type (ToType). This 418/// function returns an implicit conversion sequence that can be used 419/// to perform the initialization. Given 420/// 421/// void f(float f); 422/// void g(int i) { f(i); } 423/// 424/// this routine would produce an implicit conversion sequence to 425/// describe the initialization of f from i, which will be a standard 426/// conversion sequence containing an lvalue-to-rvalue conversion (C++ 427/// 4.1) followed by a floating-integral conversion (C++ 4.9). 428// 429/// Note that this routine only determines how the conversion can be 430/// performed; it does not actually perform the conversion. As such, 431/// it will not produce any diagnostics if no conversion is available, 432/// but will instead return an implicit conversion sequence of kind 433/// "BadConversion". 434/// 435/// If @p SuppressUserConversions, then user-defined conversions are 436/// not permitted. 437/// If @p AllowExplicit, then explicit user-defined conversions are 438/// permitted. 439/// If @p ForceRValue, then overloading is performed as if From was an rvalue, 440/// no matter its actual lvalueness. 441/// If @p UserCast, the implicit conversion is being done for a user-specified 442/// cast. 443ImplicitConversionSequence 444Sema::TryImplicitConversion(Expr* From, QualType ToType, 445 bool SuppressUserConversions, 446 bool AllowExplicit, bool ForceRValue, 447 bool InOverloadResolution, 448 bool UserCast) { 449 ImplicitConversionSequence ICS; 450 if (IsStandardConversion(From, ToType, InOverloadResolution, ICS.Standard)) { 451 ICS.setStandard(); 452 return ICS; 453 } 454 455 if (!getLangOptions().CPlusPlus) { 456 ICS.setBad(BadConversionSequence::no_conversion, From, ToType); 457 return ICS; 458 } 459 460 OverloadCandidateSet Conversions(From->getExprLoc()); 461 OverloadingResult UserDefResult 462 = IsUserDefinedConversion(From, ToType, ICS.UserDefined, Conversions, 463 !SuppressUserConversions, AllowExplicit, 464 ForceRValue, UserCast); 465 466 if (UserDefResult == OR_Success) { 467 ICS.setUserDefined(); 468 // C++ [over.ics.user]p4: 469 // A conversion of an expression of class type to the same class 470 // type is given Exact Match rank, and a conversion of an 471 // expression of class type to a base class of that type is 472 // given Conversion rank, in spite of the fact that a copy 473 // constructor (i.e., a user-defined conversion function) is 474 // called for those cases. 475 if (CXXConstructorDecl *Constructor 476 = dyn_cast<CXXConstructorDecl>(ICS.UserDefined.ConversionFunction)) { 477 QualType FromCanon 478 = Context.getCanonicalType(From->getType().getUnqualifiedType()); 479 QualType ToCanon = Context.getCanonicalType(ToType).getUnqualifiedType(); 480 if (Constructor->isCopyConstructor() && 481 (FromCanon == ToCanon || IsDerivedFrom(FromCanon, ToCanon))) { 482 // Turn this into a "standard" conversion sequence, so that it 483 // gets ranked with standard conversion sequences. 484 ICS.setStandard(); 485 ICS.Standard.setAsIdentityConversion(); 486 ICS.Standard.setFromType(From->getType()); 487 ICS.Standard.setAllToTypes(ToType); 488 ICS.Standard.CopyConstructor = Constructor; 489 if (ToCanon != FromCanon) 490 ICS.Standard.Second = ICK_Derived_To_Base; 491 } 492 } 493 494 // C++ [over.best.ics]p4: 495 // However, when considering the argument of a user-defined 496 // conversion function that is a candidate by 13.3.1.3 when 497 // invoked for the copying of the temporary in the second step 498 // of a class copy-initialization, or by 13.3.1.4, 13.3.1.5, or 499 // 13.3.1.6 in all cases, only standard conversion sequences and 500 // ellipsis conversion sequences are allowed. 501 if (SuppressUserConversions && ICS.isUserDefined()) { 502 ICS.setBad(BadConversionSequence::suppressed_user, From, ToType); 503 } 504 } else if (UserDefResult == OR_Ambiguous && !SuppressUserConversions) { 505 ICS.setAmbiguous(); 506 ICS.Ambiguous.setFromType(From->getType()); 507 ICS.Ambiguous.setToType(ToType); 508 for (OverloadCandidateSet::iterator Cand = Conversions.begin(); 509 Cand != Conversions.end(); ++Cand) 510 if (Cand->Viable) 511 ICS.Ambiguous.addConversion(Cand->Function); 512 } else { 513 ICS.setBad(BadConversionSequence::no_conversion, From, ToType); 514 } 515 516 return ICS; 517} 518 519/// \brief Determine whether the conversion from FromType to ToType is a valid 520/// conversion that strips "noreturn" off the nested function type. 521static bool IsNoReturnConversion(ASTContext &Context, QualType FromType, 522 QualType ToType, QualType &ResultTy) { 523 if (Context.hasSameUnqualifiedType(FromType, ToType)) 524 return false; 525 526 // Strip the noreturn off the type we're converting from; noreturn can 527 // safely be removed. 528 FromType = Context.getNoReturnType(FromType, false); 529 if (!Context.hasSameUnqualifiedType(FromType, ToType)) 530 return false; 531 532 ResultTy = FromType; 533 return true; 534} 535 536/// IsStandardConversion - Determines whether there is a standard 537/// conversion sequence (C++ [conv], C++ [over.ics.scs]) from the 538/// expression From to the type ToType. Standard conversion sequences 539/// only consider non-class types; for conversions that involve class 540/// types, use TryImplicitConversion. If a conversion exists, SCS will 541/// contain the standard conversion sequence required to perform this 542/// conversion and this routine will return true. Otherwise, this 543/// routine will return false and the value of SCS is unspecified. 544bool 545Sema::IsStandardConversion(Expr* From, QualType ToType, 546 bool InOverloadResolution, 547 StandardConversionSequence &SCS) { 548 QualType FromType = From->getType(); 549 550 // Standard conversions (C++ [conv]) 551 SCS.setAsIdentityConversion(); 552 SCS.DeprecatedStringLiteralToCharPtr = false; 553 SCS.IncompatibleObjC = false; 554 SCS.setFromType(FromType); 555 SCS.CopyConstructor = 0; 556 557 // There are no standard conversions for class types in C++, so 558 // abort early. When overloading in C, however, we do permit 559 if (FromType->isRecordType() || ToType->isRecordType()) { 560 if (getLangOptions().CPlusPlus) 561 return false; 562 563 // When we're overloading in C, we allow, as standard conversions, 564 } 565 566 // The first conversion can be an lvalue-to-rvalue conversion, 567 // array-to-pointer conversion, or function-to-pointer conversion 568 // (C++ 4p1). 569 570 // Lvalue-to-rvalue conversion (C++ 4.1): 571 // An lvalue (3.10) of a non-function, non-array type T can be 572 // converted to an rvalue. 573 Expr::isLvalueResult argIsLvalue = From->isLvalue(Context); 574 if (argIsLvalue == Expr::LV_Valid && 575 !FromType->isFunctionType() && !FromType->isArrayType() && 576 Context.getCanonicalType(FromType) != Context.OverloadTy) { 577 SCS.First = ICK_Lvalue_To_Rvalue; 578 579 // If T is a non-class type, the type of the rvalue is the 580 // cv-unqualified version of T. Otherwise, the type of the rvalue 581 // is T (C++ 4.1p1). C++ can't get here with class types; in C, we 582 // just strip the qualifiers because they don't matter. 583 FromType = FromType.getUnqualifiedType(); 584 } else if (FromType->isArrayType()) { 585 // Array-to-pointer conversion (C++ 4.2) 586 SCS.First = ICK_Array_To_Pointer; 587 588 // An lvalue or rvalue of type "array of N T" or "array of unknown 589 // bound of T" can be converted to an rvalue of type "pointer to 590 // T" (C++ 4.2p1). 591 FromType = Context.getArrayDecayedType(FromType); 592 593 if (IsStringLiteralToNonConstPointerConversion(From, ToType)) { 594 // This conversion is deprecated. (C++ D.4). 595 SCS.DeprecatedStringLiteralToCharPtr = true; 596 597 // For the purpose of ranking in overload resolution 598 // (13.3.3.1.1), this conversion is considered an 599 // array-to-pointer conversion followed by a qualification 600 // conversion (4.4). (C++ 4.2p2) 601 SCS.Second = ICK_Identity; 602 SCS.Third = ICK_Qualification; 603 SCS.setAllToTypes(FromType); 604 return true; 605 } 606 } else if (FromType->isFunctionType() && argIsLvalue == Expr::LV_Valid) { 607 // Function-to-pointer conversion (C++ 4.3). 608 SCS.First = ICK_Function_To_Pointer; 609 610 // An lvalue of function type T can be converted to an rvalue of 611 // type "pointer to T." The result is a pointer to the 612 // function. (C++ 4.3p1). 613 FromType = Context.getPointerType(FromType); 614 } else if (FunctionDecl *Fn 615 = ResolveAddressOfOverloadedFunction(From, ToType, false)) { 616 // Address of overloaded function (C++ [over.over]). 617 SCS.First = ICK_Function_To_Pointer; 618 619 // We were able to resolve the address of the overloaded function, 620 // so we can convert to the type of that function. 621 FromType = Fn->getType(); 622 if (ToType->isLValueReferenceType()) 623 FromType = Context.getLValueReferenceType(FromType); 624 else if (ToType->isRValueReferenceType()) 625 FromType = Context.getRValueReferenceType(FromType); 626 else if (ToType->isMemberPointerType()) { 627 // Resolve address only succeeds if both sides are member pointers, 628 // but it doesn't have to be the same class. See DR 247. 629 // Note that this means that the type of &Derived::fn can be 630 // Ret (Base::*)(Args) if the fn overload actually found is from the 631 // base class, even if it was brought into the derived class via a 632 // using declaration. The standard isn't clear on this issue at all. 633 CXXMethodDecl *M = cast<CXXMethodDecl>(Fn); 634 FromType = Context.getMemberPointerType(FromType, 635 Context.getTypeDeclType(M->getParent()).getTypePtr()); 636 } else 637 FromType = Context.getPointerType(FromType); 638 } else { 639 // We don't require any conversions for the first step. 640 SCS.First = ICK_Identity; 641 } 642 SCS.setToType(0, FromType); 643 644 // The second conversion can be an integral promotion, floating 645 // point promotion, integral conversion, floating point conversion, 646 // floating-integral conversion, pointer conversion, 647 // pointer-to-member conversion, or boolean conversion (C++ 4p1). 648 // For overloading in C, this can also be a "compatible-type" 649 // conversion. 650 bool IncompatibleObjC = false; 651 if (Context.hasSameUnqualifiedType(FromType, ToType)) { 652 // The unqualified versions of the types are the same: there's no 653 // conversion to do. 654 SCS.Second = ICK_Identity; 655 } else if (IsIntegralPromotion(From, FromType, ToType)) { 656 // Integral promotion (C++ 4.5). 657 SCS.Second = ICK_Integral_Promotion; 658 FromType = ToType.getUnqualifiedType(); 659 } else if (IsFloatingPointPromotion(FromType, ToType)) { 660 // Floating point promotion (C++ 4.6). 661 SCS.Second = ICK_Floating_Promotion; 662 FromType = ToType.getUnqualifiedType(); 663 } else if (IsComplexPromotion(FromType, ToType)) { 664 // Complex promotion (Clang extension) 665 SCS.Second = ICK_Complex_Promotion; 666 FromType = ToType.getUnqualifiedType(); 667 } else if ((FromType->isIntegralType() || FromType->isEnumeralType()) && 668 (ToType->isIntegralType() && !ToType->isEnumeralType())) { 669 // Integral conversions (C++ 4.7). 670 SCS.Second = ICK_Integral_Conversion; 671 FromType = ToType.getUnqualifiedType(); 672 } else if (FromType->isComplexType() && ToType->isComplexType()) { 673 // Complex conversions (C99 6.3.1.6) 674 SCS.Second = ICK_Complex_Conversion; 675 FromType = ToType.getUnqualifiedType(); 676 } else if ((FromType->isComplexType() && ToType->isArithmeticType()) || 677 (ToType->isComplexType() && FromType->isArithmeticType())) { 678 // Complex-real conversions (C99 6.3.1.7) 679 SCS.Second = ICK_Complex_Real; 680 FromType = ToType.getUnqualifiedType(); 681 } else if (FromType->isFloatingType() && ToType->isFloatingType()) { 682 // Floating point conversions (C++ 4.8). 683 SCS.Second = ICK_Floating_Conversion; 684 FromType = ToType.getUnqualifiedType(); 685 } else if ((FromType->isFloatingType() && 686 ToType->isIntegralType() && (!ToType->isBooleanType() && 687 !ToType->isEnumeralType())) || 688 ((FromType->isIntegralType() || FromType->isEnumeralType()) && 689 ToType->isFloatingType())) { 690 // Floating-integral conversions (C++ 4.9). 691 SCS.Second = ICK_Floating_Integral; 692 FromType = ToType.getUnqualifiedType(); 693 } else if (IsPointerConversion(From, FromType, ToType, InOverloadResolution, 694 FromType, IncompatibleObjC)) { 695 // Pointer conversions (C++ 4.10). 696 SCS.Second = ICK_Pointer_Conversion; 697 SCS.IncompatibleObjC = IncompatibleObjC; 698 } else if (IsMemberPointerConversion(From, FromType, ToType, 699 InOverloadResolution, FromType)) { 700 // Pointer to member conversions (4.11). 701 SCS.Second = ICK_Pointer_Member; 702 } else if (ToType->isBooleanType() && 703 (FromType->isArithmeticType() || 704 FromType->isEnumeralType() || 705 FromType->isAnyPointerType() || 706 FromType->isBlockPointerType() || 707 FromType->isMemberPointerType() || 708 FromType->isNullPtrType())) { 709 // Boolean conversions (C++ 4.12). 710 SCS.Second = ICK_Boolean_Conversion; 711 FromType = Context.BoolTy; 712 } else if (!getLangOptions().CPlusPlus && 713 Context.typesAreCompatible(ToType, FromType)) { 714 // Compatible conversions (Clang extension for C function overloading) 715 SCS.Second = ICK_Compatible_Conversion; 716 } else if (IsNoReturnConversion(Context, FromType, ToType, FromType)) { 717 // Treat a conversion that strips "noreturn" as an identity conversion. 718 SCS.Second = ICK_NoReturn_Adjustment; 719 } else { 720 // No second conversion required. 721 SCS.Second = ICK_Identity; 722 } 723 SCS.setToType(1, FromType); 724 725 QualType CanonFrom; 726 QualType CanonTo; 727 // The third conversion can be a qualification conversion (C++ 4p1). 728 if (IsQualificationConversion(FromType, ToType)) { 729 SCS.Third = ICK_Qualification; 730 FromType = ToType; 731 CanonFrom = Context.getCanonicalType(FromType); 732 CanonTo = Context.getCanonicalType(ToType); 733 } else { 734 // No conversion required 735 SCS.Third = ICK_Identity; 736 737 // C++ [over.best.ics]p6: 738 // [...] Any difference in top-level cv-qualification is 739 // subsumed by the initialization itself and does not constitute 740 // a conversion. [...] 741 CanonFrom = Context.getCanonicalType(FromType); 742 CanonTo = Context.getCanonicalType(ToType); 743 if (CanonFrom.getLocalUnqualifiedType() 744 == CanonTo.getLocalUnqualifiedType() && 745 CanonFrom.getLocalCVRQualifiers() != CanonTo.getLocalCVRQualifiers()) { 746 FromType = ToType; 747 CanonFrom = CanonTo; 748 } 749 } 750 SCS.setToType(2, FromType); 751 752 // If we have not converted the argument type to the parameter type, 753 // this is a bad conversion sequence. 754 if (CanonFrom != CanonTo) 755 return false; 756 757 return true; 758} 759 760/// IsIntegralPromotion - Determines whether the conversion from the 761/// expression From (whose potentially-adjusted type is FromType) to 762/// ToType is an integral promotion (C++ 4.5). If so, returns true and 763/// sets PromotedType to the promoted type. 764bool Sema::IsIntegralPromotion(Expr *From, QualType FromType, QualType ToType) { 765 const BuiltinType *To = ToType->getAs<BuiltinType>(); 766 // All integers are built-in. 767 if (!To) { 768 return false; 769 } 770 771 // An rvalue of type char, signed char, unsigned char, short int, or 772 // unsigned short int can be converted to an rvalue of type int if 773 // int can represent all the values of the source type; otherwise, 774 // the source rvalue can be converted to an rvalue of type unsigned 775 // int (C++ 4.5p1). 776 if (FromType->isPromotableIntegerType() && !FromType->isBooleanType() && 777 !FromType->isEnumeralType()) { 778 if (// We can promote any signed, promotable integer type to an int 779 (FromType->isSignedIntegerType() || 780 // We can promote any unsigned integer type whose size is 781 // less than int to an int. 782 (!FromType->isSignedIntegerType() && 783 Context.getTypeSize(FromType) < Context.getTypeSize(ToType)))) { 784 return To->getKind() == BuiltinType::Int; 785 } 786 787 return To->getKind() == BuiltinType::UInt; 788 } 789 790 // An rvalue of type wchar_t (3.9.1) or an enumeration type (7.2) 791 // can be converted to an rvalue of the first of the following types 792 // that can represent all the values of its underlying type: int, 793 // unsigned int, long, or unsigned long (C++ 4.5p2). 794 795 // We pre-calculate the promotion type for enum types. 796 if (const EnumType *FromEnumType = FromType->getAs<EnumType>()) 797 if (ToType->isIntegerType()) 798 return Context.hasSameUnqualifiedType(ToType, 799 FromEnumType->getDecl()->getPromotionType()); 800 801 if (FromType->isWideCharType() && ToType->isIntegerType()) { 802 // Determine whether the type we're converting from is signed or 803 // unsigned. 804 bool FromIsSigned; 805 uint64_t FromSize = Context.getTypeSize(FromType); 806 807 // FIXME: Is wchar_t signed or unsigned? We assume it's signed for now. 808 FromIsSigned = true; 809 810 // The types we'll try to promote to, in the appropriate 811 // order. Try each of these types. 812 QualType PromoteTypes[6] = { 813 Context.IntTy, Context.UnsignedIntTy, 814 Context.LongTy, Context.UnsignedLongTy , 815 Context.LongLongTy, Context.UnsignedLongLongTy 816 }; 817 for (int Idx = 0; Idx < 6; ++Idx) { 818 uint64_t ToSize = Context.getTypeSize(PromoteTypes[Idx]); 819 if (FromSize < ToSize || 820 (FromSize == ToSize && 821 FromIsSigned == PromoteTypes[Idx]->isSignedIntegerType())) { 822 // We found the type that we can promote to. If this is the 823 // type we wanted, we have a promotion. Otherwise, no 824 // promotion. 825 return Context.hasSameUnqualifiedType(ToType, PromoteTypes[Idx]); 826 } 827 } 828 } 829 830 // An rvalue for an integral bit-field (9.6) can be converted to an 831 // rvalue of type int if int can represent all the values of the 832 // bit-field; otherwise, it can be converted to unsigned int if 833 // unsigned int can represent all the values of the bit-field. If 834 // the bit-field is larger yet, no integral promotion applies to 835 // it. If the bit-field has an enumerated type, it is treated as any 836 // other value of that type for promotion purposes (C++ 4.5p3). 837 // FIXME: We should delay checking of bit-fields until we actually perform the 838 // conversion. 839 using llvm::APSInt; 840 if (From) 841 if (FieldDecl *MemberDecl = From->getBitField()) { 842 APSInt BitWidth; 843 if (FromType->isIntegralType() && !FromType->isEnumeralType() && 844 MemberDecl->getBitWidth()->isIntegerConstantExpr(BitWidth, Context)) { 845 APSInt ToSize(BitWidth.getBitWidth(), BitWidth.isUnsigned()); 846 ToSize = Context.getTypeSize(ToType); 847 848 // Are we promoting to an int from a bitfield that fits in an int? 849 if (BitWidth < ToSize || 850 (FromType->isSignedIntegerType() && BitWidth <= ToSize)) { 851 return To->getKind() == BuiltinType::Int; 852 } 853 854 // Are we promoting to an unsigned int from an unsigned bitfield 855 // that fits into an unsigned int? 856 if (FromType->isUnsignedIntegerType() && BitWidth <= ToSize) { 857 return To->getKind() == BuiltinType::UInt; 858 } 859 860 return false; 861 } 862 } 863 864 // An rvalue of type bool can be converted to an rvalue of type int, 865 // with false becoming zero and true becoming one (C++ 4.5p4). 866 if (FromType->isBooleanType() && To->getKind() == BuiltinType::Int) { 867 return true; 868 } 869 870 return false; 871} 872 873/// IsFloatingPointPromotion - Determines whether the conversion from 874/// FromType to ToType is a floating point promotion (C++ 4.6). If so, 875/// returns true and sets PromotedType to the promoted type. 876bool Sema::IsFloatingPointPromotion(QualType FromType, QualType ToType) { 877 /// An rvalue of type float can be converted to an rvalue of type 878 /// double. (C++ 4.6p1). 879 if (const BuiltinType *FromBuiltin = FromType->getAs<BuiltinType>()) 880 if (const BuiltinType *ToBuiltin = ToType->getAs<BuiltinType>()) { 881 if (FromBuiltin->getKind() == BuiltinType::Float && 882 ToBuiltin->getKind() == BuiltinType::Double) 883 return true; 884 885 // C99 6.3.1.5p1: 886 // When a float is promoted to double or long double, or a 887 // double is promoted to long double [...]. 888 if (!getLangOptions().CPlusPlus && 889 (FromBuiltin->getKind() == BuiltinType::Float || 890 FromBuiltin->getKind() == BuiltinType::Double) && 891 (ToBuiltin->getKind() == BuiltinType::LongDouble)) 892 return true; 893 } 894 895 return false; 896} 897 898/// \brief Determine if a conversion is a complex promotion. 899/// 900/// A complex promotion is defined as a complex -> complex conversion 901/// where the conversion between the underlying real types is a 902/// floating-point or integral promotion. 903bool Sema::IsComplexPromotion(QualType FromType, QualType ToType) { 904 const ComplexType *FromComplex = FromType->getAs<ComplexType>(); 905 if (!FromComplex) 906 return false; 907 908 const ComplexType *ToComplex = ToType->getAs<ComplexType>(); 909 if (!ToComplex) 910 return false; 911 912 return IsFloatingPointPromotion(FromComplex->getElementType(), 913 ToComplex->getElementType()) || 914 IsIntegralPromotion(0, FromComplex->getElementType(), 915 ToComplex->getElementType()); 916} 917 918/// BuildSimilarlyQualifiedPointerType - In a pointer conversion from 919/// the pointer type FromPtr to a pointer to type ToPointee, with the 920/// same type qualifiers as FromPtr has on its pointee type. ToType, 921/// if non-empty, will be a pointer to ToType that may or may not have 922/// the right set of qualifiers on its pointee. 923static QualType 924BuildSimilarlyQualifiedPointerType(const PointerType *FromPtr, 925 QualType ToPointee, QualType ToType, 926 ASTContext &Context) { 927 QualType CanonFromPointee = Context.getCanonicalType(FromPtr->getPointeeType()); 928 QualType CanonToPointee = Context.getCanonicalType(ToPointee); 929 Qualifiers Quals = CanonFromPointee.getQualifiers(); 930 931 // Exact qualifier match -> return the pointer type we're converting to. 932 if (CanonToPointee.getLocalQualifiers() == Quals) { 933 // ToType is exactly what we need. Return it. 934 if (!ToType.isNull()) 935 return ToType; 936 937 // Build a pointer to ToPointee. It has the right qualifiers 938 // already. 939 return Context.getPointerType(ToPointee); 940 } 941 942 // Just build a canonical type that has the right qualifiers. 943 return Context.getPointerType( 944 Context.getQualifiedType(CanonToPointee.getLocalUnqualifiedType(), 945 Quals)); 946} 947 948/// BuildSimilarlyQualifiedObjCObjectPointerType - In a pointer conversion from 949/// the FromType, which is an objective-c pointer, to ToType, which may or may 950/// not have the right set of qualifiers. 951static QualType 952BuildSimilarlyQualifiedObjCObjectPointerType(QualType FromType, 953 QualType ToType, 954 ASTContext &Context) { 955 QualType CanonFromType = Context.getCanonicalType(FromType); 956 QualType CanonToType = Context.getCanonicalType(ToType); 957 Qualifiers Quals = CanonFromType.getQualifiers(); 958 959 // Exact qualifier match -> return the pointer type we're converting to. 960 if (CanonToType.getLocalQualifiers() == Quals) 961 return ToType; 962 963 // Just build a canonical type that has the right qualifiers. 964 return Context.getQualifiedType(CanonToType.getLocalUnqualifiedType(), Quals); 965} 966 967static bool isNullPointerConstantForConversion(Expr *Expr, 968 bool InOverloadResolution, 969 ASTContext &Context) { 970 // Handle value-dependent integral null pointer constants correctly. 971 // http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#903 972 if (Expr->isValueDependent() && !Expr->isTypeDependent() && 973 Expr->getType()->isIntegralType()) 974 return !InOverloadResolution; 975 976 return Expr->isNullPointerConstant(Context, 977 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull 978 : Expr::NPC_ValueDependentIsNull); 979} 980 981/// IsPointerConversion - Determines whether the conversion of the 982/// expression From, which has the (possibly adjusted) type FromType, 983/// can be converted to the type ToType via a pointer conversion (C++ 984/// 4.10). If so, returns true and places the converted type (that 985/// might differ from ToType in its cv-qualifiers at some level) into 986/// ConvertedType. 987/// 988/// This routine also supports conversions to and from block pointers 989/// and conversions with Objective-C's 'id', 'id<protocols...>', and 990/// pointers to interfaces. FIXME: Once we've determined the 991/// appropriate overloading rules for Objective-C, we may want to 992/// split the Objective-C checks into a different routine; however, 993/// GCC seems to consider all of these conversions to be pointer 994/// conversions, so for now they live here. IncompatibleObjC will be 995/// set if the conversion is an allowed Objective-C conversion that 996/// should result in a warning. 997bool Sema::IsPointerConversion(Expr *From, QualType FromType, QualType ToType, 998 bool InOverloadResolution, 999 QualType& ConvertedType, 1000 bool &IncompatibleObjC) { 1001 IncompatibleObjC = false; 1002 if (isObjCPointerConversion(FromType, ToType, ConvertedType, IncompatibleObjC)) 1003 return true; 1004 1005 // Conversion from a null pointer constant to any Objective-C pointer type. 1006 if (ToType->isObjCObjectPointerType() && 1007 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1008 ConvertedType = ToType; 1009 return true; 1010 } 1011 1012 // Blocks: Block pointers can be converted to void*. 1013 if (FromType->isBlockPointerType() && ToType->isPointerType() && 1014 ToType->getAs<PointerType>()->getPointeeType()->isVoidType()) { 1015 ConvertedType = ToType; 1016 return true; 1017 } 1018 // Blocks: A null pointer constant can be converted to a block 1019 // pointer type. 1020 if (ToType->isBlockPointerType() && 1021 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1022 ConvertedType = ToType; 1023 return true; 1024 } 1025 1026 // If the left-hand-side is nullptr_t, the right side can be a null 1027 // pointer constant. 1028 if (ToType->isNullPtrType() && 1029 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1030 ConvertedType = ToType; 1031 return true; 1032 } 1033 1034 const PointerType* ToTypePtr = ToType->getAs<PointerType>(); 1035 if (!ToTypePtr) 1036 return false; 1037 1038 // A null pointer constant can be converted to a pointer type (C++ 4.10p1). 1039 if (isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1040 ConvertedType = ToType; 1041 return true; 1042 } 1043 1044 // Beyond this point, both types need to be pointers 1045 // , including objective-c pointers. 1046 QualType ToPointeeType = ToTypePtr->getPointeeType(); 1047 if (FromType->isObjCObjectPointerType() && ToPointeeType->isVoidType()) { 1048 ConvertedType = BuildSimilarlyQualifiedObjCObjectPointerType(FromType, 1049 ToType, Context); 1050 return true; 1051 1052 } 1053 const PointerType *FromTypePtr = FromType->getAs<PointerType>(); 1054 if (!FromTypePtr) 1055 return false; 1056 1057 QualType FromPointeeType = FromTypePtr->getPointeeType(); 1058 1059 // An rvalue of type "pointer to cv T," where T is an object type, 1060 // can be converted to an rvalue of type "pointer to cv void" (C++ 1061 // 4.10p2). 1062 if (FromPointeeType->isObjectType() && ToPointeeType->isVoidType()) { 1063 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1064 ToPointeeType, 1065 ToType, Context); 1066 return true; 1067 } 1068 1069 // When we're overloading in C, we allow a special kind of pointer 1070 // conversion for compatible-but-not-identical pointee types. 1071 if (!getLangOptions().CPlusPlus && 1072 Context.typesAreCompatible(FromPointeeType, ToPointeeType)) { 1073 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1074 ToPointeeType, 1075 ToType, Context); 1076 return true; 1077 } 1078 1079 // C++ [conv.ptr]p3: 1080 // 1081 // An rvalue of type "pointer to cv D," where D is a class type, 1082 // can be converted to an rvalue of type "pointer to cv B," where 1083 // B is a base class (clause 10) of D. If B is an inaccessible 1084 // (clause 11) or ambiguous (10.2) base class of D, a program that 1085 // necessitates this conversion is ill-formed. The result of the 1086 // conversion is a pointer to the base class sub-object of the 1087 // derived class object. The null pointer value is converted to 1088 // the null pointer value of the destination type. 1089 // 1090 // Note that we do not check for ambiguity or inaccessibility 1091 // here. That is handled by CheckPointerConversion. 1092 if (getLangOptions().CPlusPlus && 1093 FromPointeeType->isRecordType() && ToPointeeType->isRecordType() && 1094 !Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType) && 1095 !RequireCompleteType(From->getLocStart(), FromPointeeType, PDiag()) && 1096 IsDerivedFrom(FromPointeeType, ToPointeeType)) { 1097 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1098 ToPointeeType, 1099 ToType, Context); 1100 return true; 1101 } 1102 1103 return false; 1104} 1105 1106/// isObjCPointerConversion - Determines whether this is an 1107/// Objective-C pointer conversion. Subroutine of IsPointerConversion, 1108/// with the same arguments and return values. 1109bool Sema::isObjCPointerConversion(QualType FromType, QualType ToType, 1110 QualType& ConvertedType, 1111 bool &IncompatibleObjC) { 1112 if (!getLangOptions().ObjC1) 1113 return false; 1114 1115 // First, we handle all conversions on ObjC object pointer types. 1116 const ObjCObjectPointerType* ToObjCPtr = ToType->getAs<ObjCObjectPointerType>(); 1117 const ObjCObjectPointerType *FromObjCPtr = 1118 FromType->getAs<ObjCObjectPointerType>(); 1119 1120 if (ToObjCPtr && FromObjCPtr) { 1121 // Objective C++: We're able to convert between "id" or "Class" and a 1122 // pointer to any interface (in both directions). 1123 if (ToObjCPtr->isObjCBuiltinType() && FromObjCPtr->isObjCBuiltinType()) { 1124 ConvertedType = ToType; 1125 return true; 1126 } 1127 // Conversions with Objective-C's id<...>. 1128 if ((FromObjCPtr->isObjCQualifiedIdType() || 1129 ToObjCPtr->isObjCQualifiedIdType()) && 1130 Context.ObjCQualifiedIdTypesAreCompatible(ToType, FromType, 1131 /*compare=*/false)) { 1132 ConvertedType = ToType; 1133 return true; 1134 } 1135 // Objective C++: We're able to convert from a pointer to an 1136 // interface to a pointer to a different interface. 1137 if (Context.canAssignObjCInterfaces(ToObjCPtr, FromObjCPtr)) { 1138 const ObjCInterfaceType* LHS = ToObjCPtr->getInterfaceType(); 1139 const ObjCInterfaceType* RHS = FromObjCPtr->getInterfaceType(); 1140 if (getLangOptions().CPlusPlus && LHS && RHS && 1141 !ToObjCPtr->getPointeeType().isAtLeastAsQualifiedAs( 1142 FromObjCPtr->getPointeeType())) 1143 return false; 1144 ConvertedType = ToType; 1145 return true; 1146 } 1147 1148 if (Context.canAssignObjCInterfaces(FromObjCPtr, ToObjCPtr)) { 1149 // Okay: this is some kind of implicit downcast of Objective-C 1150 // interfaces, which is permitted. However, we're going to 1151 // complain about it. 1152 IncompatibleObjC = true; 1153 ConvertedType = FromType; 1154 return true; 1155 } 1156 } 1157 // Beyond this point, both types need to be C pointers or block pointers. 1158 QualType ToPointeeType; 1159 if (const PointerType *ToCPtr = ToType->getAs<PointerType>()) 1160 ToPointeeType = ToCPtr->getPointeeType(); 1161 else if (const BlockPointerType *ToBlockPtr = 1162 ToType->getAs<BlockPointerType>()) { 1163 // Objective C++: We're able to convert from a pointer to any object 1164 // to a block pointer type. 1165 if (FromObjCPtr && FromObjCPtr->isObjCBuiltinType()) { 1166 ConvertedType = ToType; 1167 return true; 1168 } 1169 ToPointeeType = ToBlockPtr->getPointeeType(); 1170 } 1171 else if (FromType->getAs<BlockPointerType>() && 1172 ToObjCPtr && ToObjCPtr->isObjCBuiltinType()) { 1173 // Objective C++: We're able to convert from a block pointer type to a 1174 // pointer to any object. 1175 ConvertedType = ToType; 1176 return true; 1177 } 1178 else 1179 return false; 1180 1181 QualType FromPointeeType; 1182 if (const PointerType *FromCPtr = FromType->getAs<PointerType>()) 1183 FromPointeeType = FromCPtr->getPointeeType(); 1184 else if (const BlockPointerType *FromBlockPtr = FromType->getAs<BlockPointerType>()) 1185 FromPointeeType = FromBlockPtr->getPointeeType(); 1186 else 1187 return false; 1188 1189 // If we have pointers to pointers, recursively check whether this 1190 // is an Objective-C conversion. 1191 if (FromPointeeType->isPointerType() && ToPointeeType->isPointerType() && 1192 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, 1193 IncompatibleObjC)) { 1194 // We always complain about this conversion. 1195 IncompatibleObjC = true; 1196 ConvertedType = ToType; 1197 return true; 1198 } 1199 // Allow conversion of pointee being objective-c pointer to another one; 1200 // as in I* to id. 1201 if (FromPointeeType->getAs<ObjCObjectPointerType>() && 1202 ToPointeeType->getAs<ObjCObjectPointerType>() && 1203 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, 1204 IncompatibleObjC)) { 1205 ConvertedType = ToType; 1206 return true; 1207 } 1208 1209 // If we have pointers to functions or blocks, check whether the only 1210 // differences in the argument and result types are in Objective-C 1211 // pointer conversions. If so, we permit the conversion (but 1212 // complain about it). 1213 const FunctionProtoType *FromFunctionType 1214 = FromPointeeType->getAs<FunctionProtoType>(); 1215 const FunctionProtoType *ToFunctionType 1216 = ToPointeeType->getAs<FunctionProtoType>(); 1217 if (FromFunctionType && ToFunctionType) { 1218 // If the function types are exactly the same, this isn't an 1219 // Objective-C pointer conversion. 1220 if (Context.getCanonicalType(FromPointeeType) 1221 == Context.getCanonicalType(ToPointeeType)) 1222 return false; 1223 1224 // Perform the quick checks that will tell us whether these 1225 // function types are obviously different. 1226 if (FromFunctionType->getNumArgs() != ToFunctionType->getNumArgs() || 1227 FromFunctionType->isVariadic() != ToFunctionType->isVariadic() || 1228 FromFunctionType->getTypeQuals() != ToFunctionType->getTypeQuals()) 1229 return false; 1230 1231 bool HasObjCConversion = false; 1232 if (Context.getCanonicalType(FromFunctionType->getResultType()) 1233 == Context.getCanonicalType(ToFunctionType->getResultType())) { 1234 // Okay, the types match exactly. Nothing to do. 1235 } else if (isObjCPointerConversion(FromFunctionType->getResultType(), 1236 ToFunctionType->getResultType(), 1237 ConvertedType, IncompatibleObjC)) { 1238 // Okay, we have an Objective-C pointer conversion. 1239 HasObjCConversion = true; 1240 } else { 1241 // Function types are too different. Abort. 1242 return false; 1243 } 1244 1245 // Check argument types. 1246 for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumArgs(); 1247 ArgIdx != NumArgs; ++ArgIdx) { 1248 QualType FromArgType = FromFunctionType->getArgType(ArgIdx); 1249 QualType ToArgType = ToFunctionType->getArgType(ArgIdx); 1250 if (Context.getCanonicalType(FromArgType) 1251 == Context.getCanonicalType(ToArgType)) { 1252 // Okay, the types match exactly. Nothing to do. 1253 } else if (isObjCPointerConversion(FromArgType, ToArgType, 1254 ConvertedType, IncompatibleObjC)) { 1255 // Okay, we have an Objective-C pointer conversion. 1256 HasObjCConversion = true; 1257 } else { 1258 // Argument types are too different. Abort. 1259 return false; 1260 } 1261 } 1262 1263 if (HasObjCConversion) { 1264 // We had an Objective-C conversion. Allow this pointer 1265 // conversion, but complain about it. 1266 ConvertedType = ToType; 1267 IncompatibleObjC = true; 1268 return true; 1269 } 1270 } 1271 1272 return false; 1273} 1274 1275/// CheckPointerConversion - Check the pointer conversion from the 1276/// expression From to the type ToType. This routine checks for 1277/// ambiguous or inaccessible derived-to-base pointer 1278/// conversions for which IsPointerConversion has already returned 1279/// true. It returns true and produces a diagnostic if there was an 1280/// error, or returns false otherwise. 1281bool Sema::CheckPointerConversion(Expr *From, QualType ToType, 1282 CastExpr::CastKind &Kind, 1283 bool IgnoreBaseAccess) { 1284 QualType FromType = From->getType(); 1285 1286 if (const PointerType *FromPtrType = FromType->getAs<PointerType>()) 1287 if (const PointerType *ToPtrType = ToType->getAs<PointerType>()) { 1288 QualType FromPointeeType = FromPtrType->getPointeeType(), 1289 ToPointeeType = ToPtrType->getPointeeType(); 1290 1291 if (FromPointeeType->isRecordType() && ToPointeeType->isRecordType() && 1292 !Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType)) { 1293 // We must have a derived-to-base conversion. Check an 1294 // ambiguous or inaccessible conversion. 1295 if (CheckDerivedToBaseConversion(FromPointeeType, ToPointeeType, 1296 From->getExprLoc(), 1297 From->getSourceRange(), 1298 IgnoreBaseAccess)) 1299 return true; 1300 1301 // The conversion was successful. 1302 Kind = CastExpr::CK_DerivedToBase; 1303 } 1304 } 1305 if (const ObjCObjectPointerType *FromPtrType = 1306 FromType->getAs<ObjCObjectPointerType>()) 1307 if (const ObjCObjectPointerType *ToPtrType = 1308 ToType->getAs<ObjCObjectPointerType>()) { 1309 // Objective-C++ conversions are always okay. 1310 // FIXME: We should have a different class of conversions for the 1311 // Objective-C++ implicit conversions. 1312 if (FromPtrType->isObjCBuiltinType() || ToPtrType->isObjCBuiltinType()) 1313 return false; 1314 1315 } 1316 return false; 1317} 1318 1319/// IsMemberPointerConversion - Determines whether the conversion of the 1320/// expression From, which has the (possibly adjusted) type FromType, can be 1321/// converted to the type ToType via a member pointer conversion (C++ 4.11). 1322/// If so, returns true and places the converted type (that might differ from 1323/// ToType in its cv-qualifiers at some level) into ConvertedType. 1324bool Sema::IsMemberPointerConversion(Expr *From, QualType FromType, 1325 QualType ToType, 1326 bool InOverloadResolution, 1327 QualType &ConvertedType) { 1328 const MemberPointerType *ToTypePtr = ToType->getAs<MemberPointerType>(); 1329 if (!ToTypePtr) 1330 return false; 1331 1332 // A null pointer constant can be converted to a member pointer (C++ 4.11p1) 1333 if (From->isNullPointerConstant(Context, 1334 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull 1335 : Expr::NPC_ValueDependentIsNull)) { 1336 ConvertedType = ToType; 1337 return true; 1338 } 1339 1340 // Otherwise, both types have to be member pointers. 1341 const MemberPointerType *FromTypePtr = FromType->getAs<MemberPointerType>(); 1342 if (!FromTypePtr) 1343 return false; 1344 1345 // A pointer to member of B can be converted to a pointer to member of D, 1346 // where D is derived from B (C++ 4.11p2). 1347 QualType FromClass(FromTypePtr->getClass(), 0); 1348 QualType ToClass(ToTypePtr->getClass(), 0); 1349 // FIXME: What happens when these are dependent? Is this function even called? 1350 1351 if (IsDerivedFrom(ToClass, FromClass)) { 1352 ConvertedType = Context.getMemberPointerType(FromTypePtr->getPointeeType(), 1353 ToClass.getTypePtr()); 1354 return true; 1355 } 1356 1357 return false; 1358} 1359 1360/// CheckMemberPointerConversion - Check the member pointer conversion from the 1361/// expression From to the type ToType. This routine checks for ambiguous or 1362/// virtual or inaccessible base-to-derived member pointer conversions 1363/// for which IsMemberPointerConversion has already returned true. It returns 1364/// true and produces a diagnostic if there was an error, or returns false 1365/// otherwise. 1366bool Sema::CheckMemberPointerConversion(Expr *From, QualType ToType, 1367 CastExpr::CastKind &Kind, 1368 bool IgnoreBaseAccess) { 1369 QualType FromType = From->getType(); 1370 const MemberPointerType *FromPtrType = FromType->getAs<MemberPointerType>(); 1371 if (!FromPtrType) { 1372 // This must be a null pointer to member pointer conversion 1373 assert(From->isNullPointerConstant(Context, 1374 Expr::NPC_ValueDependentIsNull) && 1375 "Expr must be null pointer constant!"); 1376 Kind = CastExpr::CK_NullToMemberPointer; 1377 return false; 1378 } 1379 1380 const MemberPointerType *ToPtrType = ToType->getAs<MemberPointerType>(); 1381 assert(ToPtrType && "No member pointer cast has a target type " 1382 "that is not a member pointer."); 1383 1384 QualType FromClass = QualType(FromPtrType->getClass(), 0); 1385 QualType ToClass = QualType(ToPtrType->getClass(), 0); 1386 1387 // FIXME: What about dependent types? 1388 assert(FromClass->isRecordType() && "Pointer into non-class."); 1389 assert(ToClass->isRecordType() && "Pointer into non-class."); 1390 1391 CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/ true, 1392 /*DetectVirtual=*/true); 1393 bool DerivationOkay = IsDerivedFrom(ToClass, FromClass, Paths); 1394 assert(DerivationOkay && 1395 "Should not have been called if derivation isn't OK."); 1396 (void)DerivationOkay; 1397 1398 if (Paths.isAmbiguous(Context.getCanonicalType(FromClass). 1399 getUnqualifiedType())) { 1400 std::string PathDisplayStr = getAmbiguousPathsDisplayString(Paths); 1401 Diag(From->getExprLoc(), diag::err_ambiguous_memptr_conv) 1402 << 0 << FromClass << ToClass << PathDisplayStr << From->getSourceRange(); 1403 return true; 1404 } 1405 1406 if (const RecordType *VBase = Paths.getDetectedVirtual()) { 1407 Diag(From->getExprLoc(), diag::err_memptr_conv_via_virtual) 1408 << FromClass << ToClass << QualType(VBase, 0) 1409 << From->getSourceRange(); 1410 return true; 1411 } 1412 1413 if (!IgnoreBaseAccess) 1414 CheckBaseClassAccess(From->getExprLoc(), /*BaseToDerived*/ true, 1415 FromClass, ToClass, Paths.front()); 1416 1417 // Must be a base to derived member conversion. 1418 Kind = CastExpr::CK_BaseToDerivedMemberPointer; 1419 return false; 1420} 1421 1422/// IsQualificationConversion - Determines whether the conversion from 1423/// an rvalue of type FromType to ToType is a qualification conversion 1424/// (C++ 4.4). 1425bool 1426Sema::IsQualificationConversion(QualType FromType, QualType ToType) { 1427 FromType = Context.getCanonicalType(FromType); 1428 ToType = Context.getCanonicalType(ToType); 1429 1430 // If FromType and ToType are the same type, this is not a 1431 // qualification conversion. 1432 if (FromType.getUnqualifiedType() == ToType.getUnqualifiedType()) 1433 return false; 1434 1435 // (C++ 4.4p4): 1436 // A conversion can add cv-qualifiers at levels other than the first 1437 // in multi-level pointers, subject to the following rules: [...] 1438 bool PreviousToQualsIncludeConst = true; 1439 bool UnwrappedAnyPointer = false; 1440 while (UnwrapSimilarPointerTypes(FromType, ToType)) { 1441 // Within each iteration of the loop, we check the qualifiers to 1442 // determine if this still looks like a qualification 1443 // conversion. Then, if all is well, we unwrap one more level of 1444 // pointers or pointers-to-members and do it all again 1445 // until there are no more pointers or pointers-to-members left to 1446 // unwrap. 1447 UnwrappedAnyPointer = true; 1448 1449 // -- for every j > 0, if const is in cv 1,j then const is in cv 1450 // 2,j, and similarly for volatile. 1451 if (!ToType.isAtLeastAsQualifiedAs(FromType)) 1452 return false; 1453 1454 // -- if the cv 1,j and cv 2,j are different, then const is in 1455 // every cv for 0 < k < j. 1456 if (FromType.getCVRQualifiers() != ToType.getCVRQualifiers() 1457 && !PreviousToQualsIncludeConst) 1458 return false; 1459 1460 // Keep track of whether all prior cv-qualifiers in the "to" type 1461 // include const. 1462 PreviousToQualsIncludeConst 1463 = PreviousToQualsIncludeConst && ToType.isConstQualified(); 1464 } 1465 1466 // We are left with FromType and ToType being the pointee types 1467 // after unwrapping the original FromType and ToType the same number 1468 // of types. If we unwrapped any pointers, and if FromType and 1469 // ToType have the same unqualified type (since we checked 1470 // qualifiers above), then this is a qualification conversion. 1471 return UnwrappedAnyPointer && Context.hasSameUnqualifiedType(FromType,ToType); 1472} 1473 1474/// Determines whether there is a user-defined conversion sequence 1475/// (C++ [over.ics.user]) that converts expression From to the type 1476/// ToType. If such a conversion exists, User will contain the 1477/// user-defined conversion sequence that performs such a conversion 1478/// and this routine will return true. Otherwise, this routine returns 1479/// false and User is unspecified. 1480/// 1481/// \param AllowConversionFunctions true if the conversion should 1482/// consider conversion functions at all. If false, only constructors 1483/// will be considered. 1484/// 1485/// \param AllowExplicit true if the conversion should consider C++0x 1486/// "explicit" conversion functions as well as non-explicit conversion 1487/// functions (C++0x [class.conv.fct]p2). 1488/// 1489/// \param ForceRValue true if the expression should be treated as an rvalue 1490/// for overload resolution. 1491/// \param UserCast true if looking for user defined conversion for a static 1492/// cast. 1493OverloadingResult Sema::IsUserDefinedConversion(Expr *From, QualType ToType, 1494 UserDefinedConversionSequence& User, 1495 OverloadCandidateSet& CandidateSet, 1496 bool AllowConversionFunctions, 1497 bool AllowExplicit, 1498 bool ForceRValue, 1499 bool UserCast) { 1500 if (const RecordType *ToRecordType = ToType->getAs<RecordType>()) { 1501 if (RequireCompleteType(From->getLocStart(), ToType, PDiag())) { 1502 // We're not going to find any constructors. 1503 } else if (CXXRecordDecl *ToRecordDecl 1504 = dyn_cast<CXXRecordDecl>(ToRecordType->getDecl())) { 1505 // C++ [over.match.ctor]p1: 1506 // When objects of class type are direct-initialized (8.5), or 1507 // copy-initialized from an expression of the same or a 1508 // derived class type (8.5), overload resolution selects the 1509 // constructor. [...] For copy-initialization, the candidate 1510 // functions are all the converting constructors (12.3.1) of 1511 // that class. The argument list is the expression-list within 1512 // the parentheses of the initializer. 1513 bool SuppressUserConversions = !UserCast; 1514 if (Context.hasSameUnqualifiedType(ToType, From->getType()) || 1515 IsDerivedFrom(From->getType(), ToType)) { 1516 SuppressUserConversions = false; 1517 AllowConversionFunctions = false; 1518 } 1519 1520 DeclarationName ConstructorName 1521 = Context.DeclarationNames.getCXXConstructorName( 1522 Context.getCanonicalType(ToType).getUnqualifiedType()); 1523 DeclContext::lookup_iterator Con, ConEnd; 1524 for (llvm::tie(Con, ConEnd) 1525 = ToRecordDecl->lookup(ConstructorName); 1526 Con != ConEnd; ++Con) { 1527 // Find the constructor (which may be a template). 1528 CXXConstructorDecl *Constructor = 0; 1529 FunctionTemplateDecl *ConstructorTmpl 1530 = dyn_cast<FunctionTemplateDecl>(*Con); 1531 if (ConstructorTmpl) 1532 Constructor 1533 = cast<CXXConstructorDecl>(ConstructorTmpl->getTemplatedDecl()); 1534 else 1535 Constructor = cast<CXXConstructorDecl>(*Con); 1536 1537 if (!Constructor->isInvalidDecl() && 1538 Constructor->isConvertingConstructor(AllowExplicit)) { 1539 if (ConstructorTmpl) 1540 AddTemplateOverloadCandidate(ConstructorTmpl, 1541 ConstructorTmpl->getAccess(), 1542 /*ExplicitArgs*/ 0, 1543 &From, 1, CandidateSet, 1544 SuppressUserConversions, ForceRValue); 1545 else 1546 // Allow one user-defined conversion when user specifies a 1547 // From->ToType conversion via an static cast (c-style, etc). 1548 AddOverloadCandidate(Constructor, Constructor->getAccess(), 1549 &From, 1, CandidateSet, 1550 SuppressUserConversions, ForceRValue); 1551 } 1552 } 1553 } 1554 } 1555 1556 if (!AllowConversionFunctions) { 1557 // Don't allow any conversion functions to enter the overload set. 1558 } else if (RequireCompleteType(From->getLocStart(), From->getType(), 1559 PDiag(0) 1560 << From->getSourceRange())) { 1561 // No conversion functions from incomplete types. 1562 } else if (const RecordType *FromRecordType 1563 = From->getType()->getAs<RecordType>()) { 1564 if (CXXRecordDecl *FromRecordDecl 1565 = dyn_cast<CXXRecordDecl>(FromRecordType->getDecl())) { 1566 // Add all of the conversion functions as candidates. 1567 const UnresolvedSetImpl *Conversions 1568 = FromRecordDecl->getVisibleConversionFunctions(); 1569 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 1570 E = Conversions->end(); I != E; ++I) { 1571 NamedDecl *D = *I; 1572 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext()); 1573 if (isa<UsingShadowDecl>(D)) 1574 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 1575 1576 CXXConversionDecl *Conv; 1577 FunctionTemplateDecl *ConvTemplate; 1578 if ((ConvTemplate = dyn_cast<FunctionTemplateDecl>(*I))) 1579 Conv = dyn_cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 1580 else 1581 Conv = dyn_cast<CXXConversionDecl>(*I); 1582 1583 if (AllowExplicit || !Conv->isExplicit()) { 1584 if (ConvTemplate) 1585 AddTemplateConversionCandidate(ConvTemplate, I.getAccess(), 1586 ActingContext, From, ToType, 1587 CandidateSet); 1588 else 1589 AddConversionCandidate(Conv, I.getAccess(), ActingContext, 1590 From, ToType, CandidateSet); 1591 } 1592 } 1593 } 1594 } 1595 1596 OverloadCandidateSet::iterator Best; 1597 switch (BestViableFunction(CandidateSet, From->getLocStart(), Best)) { 1598 case OR_Success: 1599 // Record the standard conversion we used and the conversion function. 1600 if (CXXConstructorDecl *Constructor 1601 = dyn_cast<CXXConstructorDecl>(Best->Function)) { 1602 // C++ [over.ics.user]p1: 1603 // If the user-defined conversion is specified by a 1604 // constructor (12.3.1), the initial standard conversion 1605 // sequence converts the source type to the type required by 1606 // the argument of the constructor. 1607 // 1608 QualType ThisType = Constructor->getThisType(Context); 1609 if (Best->Conversions[0].isEllipsis()) 1610 User.EllipsisConversion = true; 1611 else { 1612 User.Before = Best->Conversions[0].Standard; 1613 User.EllipsisConversion = false; 1614 } 1615 User.ConversionFunction = Constructor; 1616 User.After.setAsIdentityConversion(); 1617 User.After.setFromType( 1618 ThisType->getAs<PointerType>()->getPointeeType()); 1619 User.After.setAllToTypes(ToType); 1620 return OR_Success; 1621 } else if (CXXConversionDecl *Conversion 1622 = dyn_cast<CXXConversionDecl>(Best->Function)) { 1623 // C++ [over.ics.user]p1: 1624 // 1625 // [...] If the user-defined conversion is specified by a 1626 // conversion function (12.3.2), the initial standard 1627 // conversion sequence converts the source type to the 1628 // implicit object parameter of the conversion function. 1629 User.Before = Best->Conversions[0].Standard; 1630 User.ConversionFunction = Conversion; 1631 User.EllipsisConversion = false; 1632 1633 // C++ [over.ics.user]p2: 1634 // The second standard conversion sequence converts the 1635 // result of the user-defined conversion to the target type 1636 // for the sequence. Since an implicit conversion sequence 1637 // is an initialization, the special rules for 1638 // initialization by user-defined conversion apply when 1639 // selecting the best user-defined conversion for a 1640 // user-defined conversion sequence (see 13.3.3 and 1641 // 13.3.3.1). 1642 User.After = Best->FinalConversion; 1643 return OR_Success; 1644 } else { 1645 assert(false && "Not a constructor or conversion function?"); 1646 return OR_No_Viable_Function; 1647 } 1648 1649 case OR_No_Viable_Function: 1650 return OR_No_Viable_Function; 1651 case OR_Deleted: 1652 // No conversion here! We're done. 1653 return OR_Deleted; 1654 1655 case OR_Ambiguous: 1656 return OR_Ambiguous; 1657 } 1658 1659 return OR_No_Viable_Function; 1660} 1661 1662bool 1663Sema::DiagnoseMultipleUserDefinedConversion(Expr *From, QualType ToType) { 1664 ImplicitConversionSequence ICS; 1665 OverloadCandidateSet CandidateSet(From->getExprLoc()); 1666 OverloadingResult OvResult = 1667 IsUserDefinedConversion(From, ToType, ICS.UserDefined, 1668 CandidateSet, true, false, false); 1669 if (OvResult == OR_Ambiguous) 1670 Diag(From->getSourceRange().getBegin(), 1671 diag::err_typecheck_ambiguous_condition) 1672 << From->getType() << ToType << From->getSourceRange(); 1673 else if (OvResult == OR_No_Viable_Function && !CandidateSet.empty()) 1674 Diag(From->getSourceRange().getBegin(), 1675 diag::err_typecheck_nonviable_condition) 1676 << From->getType() << ToType << From->getSourceRange(); 1677 else 1678 return false; 1679 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, &From, 1); 1680 return true; 1681} 1682 1683/// CompareImplicitConversionSequences - Compare two implicit 1684/// conversion sequences to determine whether one is better than the 1685/// other or if they are indistinguishable (C++ 13.3.3.2). 1686ImplicitConversionSequence::CompareKind 1687Sema::CompareImplicitConversionSequences(const ImplicitConversionSequence& ICS1, 1688 const ImplicitConversionSequence& ICS2) 1689{ 1690 // (C++ 13.3.3.2p2): When comparing the basic forms of implicit 1691 // conversion sequences (as defined in 13.3.3.1) 1692 // -- a standard conversion sequence (13.3.3.1.1) is a better 1693 // conversion sequence than a user-defined conversion sequence or 1694 // an ellipsis conversion sequence, and 1695 // -- a user-defined conversion sequence (13.3.3.1.2) is a better 1696 // conversion sequence than an ellipsis conversion sequence 1697 // (13.3.3.1.3). 1698 // 1699 // C++0x [over.best.ics]p10: 1700 // For the purpose of ranking implicit conversion sequences as 1701 // described in 13.3.3.2, the ambiguous conversion sequence is 1702 // treated as a user-defined sequence that is indistinguishable 1703 // from any other user-defined conversion sequence. 1704 if (ICS1.getKind() < ICS2.getKind()) { 1705 if (!(ICS1.isUserDefined() && ICS2.isAmbiguous())) 1706 return ImplicitConversionSequence::Better; 1707 } else if (ICS2.getKind() < ICS1.getKind()) { 1708 if (!(ICS2.isUserDefined() && ICS1.isAmbiguous())) 1709 return ImplicitConversionSequence::Worse; 1710 } 1711 1712 if (ICS1.isAmbiguous() || ICS2.isAmbiguous()) 1713 return ImplicitConversionSequence::Indistinguishable; 1714 1715 // Two implicit conversion sequences of the same form are 1716 // indistinguishable conversion sequences unless one of the 1717 // following rules apply: (C++ 13.3.3.2p3): 1718 if (ICS1.isStandard()) 1719 return CompareStandardConversionSequences(ICS1.Standard, ICS2.Standard); 1720 else if (ICS1.isUserDefined()) { 1721 // User-defined conversion sequence U1 is a better conversion 1722 // sequence than another user-defined conversion sequence U2 if 1723 // they contain the same user-defined conversion function or 1724 // constructor and if the second standard conversion sequence of 1725 // U1 is better than the second standard conversion sequence of 1726 // U2 (C++ 13.3.3.2p3). 1727 if (ICS1.UserDefined.ConversionFunction == 1728 ICS2.UserDefined.ConversionFunction) 1729 return CompareStandardConversionSequences(ICS1.UserDefined.After, 1730 ICS2.UserDefined.After); 1731 } 1732 1733 return ImplicitConversionSequence::Indistinguishable; 1734} 1735 1736// Per 13.3.3.2p3, compare the given standard conversion sequences to 1737// determine if one is a proper subset of the other. 1738static ImplicitConversionSequence::CompareKind 1739compareStandardConversionSubsets(ASTContext &Context, 1740 const StandardConversionSequence& SCS1, 1741 const StandardConversionSequence& SCS2) { 1742 ImplicitConversionSequence::CompareKind Result 1743 = ImplicitConversionSequence::Indistinguishable; 1744 1745 if (SCS1.Second != SCS2.Second) { 1746 if (SCS1.Second == ICK_Identity) 1747 Result = ImplicitConversionSequence::Better; 1748 else if (SCS2.Second == ICK_Identity) 1749 Result = ImplicitConversionSequence::Worse; 1750 else 1751 return ImplicitConversionSequence::Indistinguishable; 1752 } else if (!Context.hasSameType(SCS1.getToType(1), SCS2.getToType(1))) 1753 return ImplicitConversionSequence::Indistinguishable; 1754 1755 if (SCS1.Third == SCS2.Third) { 1756 return Context.hasSameType(SCS1.getToType(2), SCS2.getToType(2))? Result 1757 : ImplicitConversionSequence::Indistinguishable; 1758 } 1759 1760 if (SCS1.Third == ICK_Identity) 1761 return Result == ImplicitConversionSequence::Worse 1762 ? ImplicitConversionSequence::Indistinguishable 1763 : ImplicitConversionSequence::Better; 1764 1765 if (SCS2.Third == ICK_Identity) 1766 return Result == ImplicitConversionSequence::Better 1767 ? ImplicitConversionSequence::Indistinguishable 1768 : ImplicitConversionSequence::Worse; 1769 1770 return ImplicitConversionSequence::Indistinguishable; 1771} 1772 1773/// CompareStandardConversionSequences - Compare two standard 1774/// conversion sequences to determine whether one is better than the 1775/// other or if they are indistinguishable (C++ 13.3.3.2p3). 1776ImplicitConversionSequence::CompareKind 1777Sema::CompareStandardConversionSequences(const StandardConversionSequence& SCS1, 1778 const StandardConversionSequence& SCS2) 1779{ 1780 // Standard conversion sequence S1 is a better conversion sequence 1781 // than standard conversion sequence S2 if (C++ 13.3.3.2p3): 1782 1783 // -- S1 is a proper subsequence of S2 (comparing the conversion 1784 // sequences in the canonical form defined by 13.3.3.1.1, 1785 // excluding any Lvalue Transformation; the identity conversion 1786 // sequence is considered to be a subsequence of any 1787 // non-identity conversion sequence) or, if not that, 1788 if (ImplicitConversionSequence::CompareKind CK 1789 = compareStandardConversionSubsets(Context, SCS1, SCS2)) 1790 return CK; 1791 1792 // -- the rank of S1 is better than the rank of S2 (by the rules 1793 // defined below), or, if not that, 1794 ImplicitConversionRank Rank1 = SCS1.getRank(); 1795 ImplicitConversionRank Rank2 = SCS2.getRank(); 1796 if (Rank1 < Rank2) 1797 return ImplicitConversionSequence::Better; 1798 else if (Rank2 < Rank1) 1799 return ImplicitConversionSequence::Worse; 1800 1801 // (C++ 13.3.3.2p4): Two conversion sequences with the same rank 1802 // are indistinguishable unless one of the following rules 1803 // applies: 1804 1805 // A conversion that is not a conversion of a pointer, or 1806 // pointer to member, to bool is better than another conversion 1807 // that is such a conversion. 1808 if (SCS1.isPointerConversionToBool() != SCS2.isPointerConversionToBool()) 1809 return SCS2.isPointerConversionToBool() 1810 ? ImplicitConversionSequence::Better 1811 : ImplicitConversionSequence::Worse; 1812 1813 // C++ [over.ics.rank]p4b2: 1814 // 1815 // If class B is derived directly or indirectly from class A, 1816 // conversion of B* to A* is better than conversion of B* to 1817 // void*, and conversion of A* to void* is better than conversion 1818 // of B* to void*. 1819 bool SCS1ConvertsToVoid 1820 = SCS1.isPointerConversionToVoidPointer(Context); 1821 bool SCS2ConvertsToVoid 1822 = SCS2.isPointerConversionToVoidPointer(Context); 1823 if (SCS1ConvertsToVoid != SCS2ConvertsToVoid) { 1824 // Exactly one of the conversion sequences is a conversion to 1825 // a void pointer; it's the worse conversion. 1826 return SCS2ConvertsToVoid ? ImplicitConversionSequence::Better 1827 : ImplicitConversionSequence::Worse; 1828 } else if (!SCS1ConvertsToVoid && !SCS2ConvertsToVoid) { 1829 // Neither conversion sequence converts to a void pointer; compare 1830 // their derived-to-base conversions. 1831 if (ImplicitConversionSequence::CompareKind DerivedCK 1832 = CompareDerivedToBaseConversions(SCS1, SCS2)) 1833 return DerivedCK; 1834 } else if (SCS1ConvertsToVoid && SCS2ConvertsToVoid) { 1835 // Both conversion sequences are conversions to void 1836 // pointers. Compare the source types to determine if there's an 1837 // inheritance relationship in their sources. 1838 QualType FromType1 = SCS1.getFromType(); 1839 QualType FromType2 = SCS2.getFromType(); 1840 1841 // Adjust the types we're converting from via the array-to-pointer 1842 // conversion, if we need to. 1843 if (SCS1.First == ICK_Array_To_Pointer) 1844 FromType1 = Context.getArrayDecayedType(FromType1); 1845 if (SCS2.First == ICK_Array_To_Pointer) 1846 FromType2 = Context.getArrayDecayedType(FromType2); 1847 1848 QualType FromPointee1 1849 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1850 QualType FromPointee2 1851 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1852 1853 if (IsDerivedFrom(FromPointee2, FromPointee1)) 1854 return ImplicitConversionSequence::Better; 1855 else if (IsDerivedFrom(FromPointee1, FromPointee2)) 1856 return ImplicitConversionSequence::Worse; 1857 1858 // Objective-C++: If one interface is more specific than the 1859 // other, it is the better one. 1860 const ObjCInterfaceType* FromIface1 = FromPointee1->getAs<ObjCInterfaceType>(); 1861 const ObjCInterfaceType* FromIface2 = FromPointee2->getAs<ObjCInterfaceType>(); 1862 if (FromIface1 && FromIface1) { 1863 if (Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 1864 return ImplicitConversionSequence::Better; 1865 else if (Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 1866 return ImplicitConversionSequence::Worse; 1867 } 1868 } 1869 1870 // Compare based on qualification conversions (C++ 13.3.3.2p3, 1871 // bullet 3). 1872 if (ImplicitConversionSequence::CompareKind QualCK 1873 = CompareQualificationConversions(SCS1, SCS2)) 1874 return QualCK; 1875 1876 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding) { 1877 // C++0x [over.ics.rank]p3b4: 1878 // -- S1 and S2 are reference bindings (8.5.3) and neither refers to an 1879 // implicit object parameter of a non-static member function declared 1880 // without a ref-qualifier, and S1 binds an rvalue reference to an 1881 // rvalue and S2 binds an lvalue reference. 1882 // FIXME: We don't know if we're dealing with the implicit object parameter, 1883 // or if the member function in this case has a ref qualifier. 1884 // (Of course, we don't have ref qualifiers yet.) 1885 if (SCS1.RRefBinding != SCS2.RRefBinding) 1886 return SCS1.RRefBinding ? ImplicitConversionSequence::Better 1887 : ImplicitConversionSequence::Worse; 1888 1889 // C++ [over.ics.rank]p3b4: 1890 // -- S1 and S2 are reference bindings (8.5.3), and the types to 1891 // which the references refer are the same type except for 1892 // top-level cv-qualifiers, and the type to which the reference 1893 // initialized by S2 refers is more cv-qualified than the type 1894 // to which the reference initialized by S1 refers. 1895 QualType T1 = SCS1.getToType(2); 1896 QualType T2 = SCS2.getToType(2); 1897 T1 = Context.getCanonicalType(T1); 1898 T2 = Context.getCanonicalType(T2); 1899 Qualifiers T1Quals, T2Quals; 1900 QualType UnqualT1 = Context.getUnqualifiedArrayType(T1, T1Quals); 1901 QualType UnqualT2 = Context.getUnqualifiedArrayType(T2, T2Quals); 1902 if (UnqualT1 == UnqualT2) { 1903 // If the type is an array type, promote the element qualifiers to the type 1904 // for comparison. 1905 if (isa<ArrayType>(T1) && T1Quals) 1906 T1 = Context.getQualifiedType(UnqualT1, T1Quals); 1907 if (isa<ArrayType>(T2) && T2Quals) 1908 T2 = Context.getQualifiedType(UnqualT2, T2Quals); 1909 if (T2.isMoreQualifiedThan(T1)) 1910 return ImplicitConversionSequence::Better; 1911 else if (T1.isMoreQualifiedThan(T2)) 1912 return ImplicitConversionSequence::Worse; 1913 } 1914 } 1915 1916 return ImplicitConversionSequence::Indistinguishable; 1917} 1918 1919/// CompareQualificationConversions - Compares two standard conversion 1920/// sequences to determine whether they can be ranked based on their 1921/// qualification conversions (C++ 13.3.3.2p3 bullet 3). 1922ImplicitConversionSequence::CompareKind 1923Sema::CompareQualificationConversions(const StandardConversionSequence& SCS1, 1924 const StandardConversionSequence& SCS2) { 1925 // C++ 13.3.3.2p3: 1926 // -- S1 and S2 differ only in their qualification conversion and 1927 // yield similar types T1 and T2 (C++ 4.4), respectively, and the 1928 // cv-qualification signature of type T1 is a proper subset of 1929 // the cv-qualification signature of type T2, and S1 is not the 1930 // deprecated string literal array-to-pointer conversion (4.2). 1931 if (SCS1.First != SCS2.First || SCS1.Second != SCS2.Second || 1932 SCS1.Third != SCS2.Third || SCS1.Third != ICK_Qualification) 1933 return ImplicitConversionSequence::Indistinguishable; 1934 1935 // FIXME: the example in the standard doesn't use a qualification 1936 // conversion (!) 1937 QualType T1 = SCS1.getToType(2); 1938 QualType T2 = SCS2.getToType(2); 1939 T1 = Context.getCanonicalType(T1); 1940 T2 = Context.getCanonicalType(T2); 1941 Qualifiers T1Quals, T2Quals; 1942 QualType UnqualT1 = Context.getUnqualifiedArrayType(T1, T1Quals); 1943 QualType UnqualT2 = Context.getUnqualifiedArrayType(T2, T2Quals); 1944 1945 // If the types are the same, we won't learn anything by unwrapped 1946 // them. 1947 if (UnqualT1 == UnqualT2) 1948 return ImplicitConversionSequence::Indistinguishable; 1949 1950 // If the type is an array type, promote the element qualifiers to the type 1951 // for comparison. 1952 if (isa<ArrayType>(T1) && T1Quals) 1953 T1 = Context.getQualifiedType(UnqualT1, T1Quals); 1954 if (isa<ArrayType>(T2) && T2Quals) 1955 T2 = Context.getQualifiedType(UnqualT2, T2Quals); 1956 1957 ImplicitConversionSequence::CompareKind Result 1958 = ImplicitConversionSequence::Indistinguishable; 1959 while (UnwrapSimilarPointerTypes(T1, T2)) { 1960 // Within each iteration of the loop, we check the qualifiers to 1961 // determine if this still looks like a qualification 1962 // conversion. Then, if all is well, we unwrap one more level of 1963 // pointers or pointers-to-members and do it all again 1964 // until there are no more pointers or pointers-to-members left 1965 // to unwrap. This essentially mimics what 1966 // IsQualificationConversion does, but here we're checking for a 1967 // strict subset of qualifiers. 1968 if (T1.getCVRQualifiers() == T2.getCVRQualifiers()) 1969 // The qualifiers are the same, so this doesn't tell us anything 1970 // about how the sequences rank. 1971 ; 1972 else if (T2.isMoreQualifiedThan(T1)) { 1973 // T1 has fewer qualifiers, so it could be the better sequence. 1974 if (Result == ImplicitConversionSequence::Worse) 1975 // Neither has qualifiers that are a subset of the other's 1976 // qualifiers. 1977 return ImplicitConversionSequence::Indistinguishable; 1978 1979 Result = ImplicitConversionSequence::Better; 1980 } else if (T1.isMoreQualifiedThan(T2)) { 1981 // T2 has fewer qualifiers, so it could be the better sequence. 1982 if (Result == ImplicitConversionSequence::Better) 1983 // Neither has qualifiers that are a subset of the other's 1984 // qualifiers. 1985 return ImplicitConversionSequence::Indistinguishable; 1986 1987 Result = ImplicitConversionSequence::Worse; 1988 } else { 1989 // Qualifiers are disjoint. 1990 return ImplicitConversionSequence::Indistinguishable; 1991 } 1992 1993 // If the types after this point are equivalent, we're done. 1994 if (Context.hasSameUnqualifiedType(T1, T2)) 1995 break; 1996 } 1997 1998 // Check that the winning standard conversion sequence isn't using 1999 // the deprecated string literal array to pointer conversion. 2000 switch (Result) { 2001 case ImplicitConversionSequence::Better: 2002 if (SCS1.DeprecatedStringLiteralToCharPtr) 2003 Result = ImplicitConversionSequence::Indistinguishable; 2004 break; 2005 2006 case ImplicitConversionSequence::Indistinguishable: 2007 break; 2008 2009 case ImplicitConversionSequence::Worse: 2010 if (SCS2.DeprecatedStringLiteralToCharPtr) 2011 Result = ImplicitConversionSequence::Indistinguishable; 2012 break; 2013 } 2014 2015 return Result; 2016} 2017 2018/// CompareDerivedToBaseConversions - Compares two standard conversion 2019/// sequences to determine whether they can be ranked based on their 2020/// various kinds of derived-to-base conversions (C++ 2021/// [over.ics.rank]p4b3). As part of these checks, we also look at 2022/// conversions between Objective-C interface types. 2023ImplicitConversionSequence::CompareKind 2024Sema::CompareDerivedToBaseConversions(const StandardConversionSequence& SCS1, 2025 const StandardConversionSequence& SCS2) { 2026 QualType FromType1 = SCS1.getFromType(); 2027 QualType ToType1 = SCS1.getToType(1); 2028 QualType FromType2 = SCS2.getFromType(); 2029 QualType ToType2 = SCS2.getToType(1); 2030 2031 // Adjust the types we're converting from via the array-to-pointer 2032 // conversion, if we need to. 2033 if (SCS1.First == ICK_Array_To_Pointer) 2034 FromType1 = Context.getArrayDecayedType(FromType1); 2035 if (SCS2.First == ICK_Array_To_Pointer) 2036 FromType2 = Context.getArrayDecayedType(FromType2); 2037 2038 // Canonicalize all of the types. 2039 FromType1 = Context.getCanonicalType(FromType1); 2040 ToType1 = Context.getCanonicalType(ToType1); 2041 FromType2 = Context.getCanonicalType(FromType2); 2042 ToType2 = Context.getCanonicalType(ToType2); 2043 2044 // C++ [over.ics.rank]p4b3: 2045 // 2046 // If class B is derived directly or indirectly from class A and 2047 // class C is derived directly or indirectly from B, 2048 // 2049 // For Objective-C, we let A, B, and C also be Objective-C 2050 // interfaces. 2051 2052 // Compare based on pointer conversions. 2053 if (SCS1.Second == ICK_Pointer_Conversion && 2054 SCS2.Second == ICK_Pointer_Conversion && 2055 /*FIXME: Remove if Objective-C id conversions get their own rank*/ 2056 FromType1->isPointerType() && FromType2->isPointerType() && 2057 ToType1->isPointerType() && ToType2->isPointerType()) { 2058 QualType FromPointee1 2059 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2060 QualType ToPointee1 2061 = ToType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2062 QualType FromPointee2 2063 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2064 QualType ToPointee2 2065 = ToType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2066 2067 const ObjCInterfaceType* FromIface1 = FromPointee1->getAs<ObjCInterfaceType>(); 2068 const ObjCInterfaceType* FromIface2 = FromPointee2->getAs<ObjCInterfaceType>(); 2069 const ObjCInterfaceType* ToIface1 = ToPointee1->getAs<ObjCInterfaceType>(); 2070 const ObjCInterfaceType* ToIface2 = ToPointee2->getAs<ObjCInterfaceType>(); 2071 2072 // -- conversion of C* to B* is better than conversion of C* to A*, 2073 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 2074 if (IsDerivedFrom(ToPointee1, ToPointee2)) 2075 return ImplicitConversionSequence::Better; 2076 else if (IsDerivedFrom(ToPointee2, ToPointee1)) 2077 return ImplicitConversionSequence::Worse; 2078 2079 if (ToIface1 && ToIface2) { 2080 if (Context.canAssignObjCInterfaces(ToIface2, ToIface1)) 2081 return ImplicitConversionSequence::Better; 2082 else if (Context.canAssignObjCInterfaces(ToIface1, ToIface2)) 2083 return ImplicitConversionSequence::Worse; 2084 } 2085 } 2086 2087 // -- conversion of B* to A* is better than conversion of C* to A*, 2088 if (FromPointee1 != FromPointee2 && ToPointee1 == ToPointee2) { 2089 if (IsDerivedFrom(FromPointee2, FromPointee1)) 2090 return ImplicitConversionSequence::Better; 2091 else if (IsDerivedFrom(FromPointee1, FromPointee2)) 2092 return ImplicitConversionSequence::Worse; 2093 2094 if (FromIface1 && FromIface2) { 2095 if (Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 2096 return ImplicitConversionSequence::Better; 2097 else if (Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 2098 return ImplicitConversionSequence::Worse; 2099 } 2100 } 2101 } 2102 2103 // Ranking of member-pointer types. 2104 if (SCS1.Second == ICK_Pointer_Member && SCS2.Second == ICK_Pointer_Member && 2105 FromType1->isMemberPointerType() && FromType2->isMemberPointerType() && 2106 ToType1->isMemberPointerType() && ToType2->isMemberPointerType()) { 2107 const MemberPointerType * FromMemPointer1 = 2108 FromType1->getAs<MemberPointerType>(); 2109 const MemberPointerType * ToMemPointer1 = 2110 ToType1->getAs<MemberPointerType>(); 2111 const MemberPointerType * FromMemPointer2 = 2112 FromType2->getAs<MemberPointerType>(); 2113 const MemberPointerType * ToMemPointer2 = 2114 ToType2->getAs<MemberPointerType>(); 2115 const Type *FromPointeeType1 = FromMemPointer1->getClass(); 2116 const Type *ToPointeeType1 = ToMemPointer1->getClass(); 2117 const Type *FromPointeeType2 = FromMemPointer2->getClass(); 2118 const Type *ToPointeeType2 = ToMemPointer2->getClass(); 2119 QualType FromPointee1 = QualType(FromPointeeType1, 0).getUnqualifiedType(); 2120 QualType ToPointee1 = QualType(ToPointeeType1, 0).getUnqualifiedType(); 2121 QualType FromPointee2 = QualType(FromPointeeType2, 0).getUnqualifiedType(); 2122 QualType ToPointee2 = QualType(ToPointeeType2, 0).getUnqualifiedType(); 2123 // conversion of A::* to B::* is better than conversion of A::* to C::*, 2124 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 2125 if (IsDerivedFrom(ToPointee1, ToPointee2)) 2126 return ImplicitConversionSequence::Worse; 2127 else if (IsDerivedFrom(ToPointee2, ToPointee1)) 2128 return ImplicitConversionSequence::Better; 2129 } 2130 // conversion of B::* to C::* is better than conversion of A::* to C::* 2131 if (ToPointee1 == ToPointee2 && FromPointee1 != FromPointee2) { 2132 if (IsDerivedFrom(FromPointee1, FromPointee2)) 2133 return ImplicitConversionSequence::Better; 2134 else if (IsDerivedFrom(FromPointee2, FromPointee1)) 2135 return ImplicitConversionSequence::Worse; 2136 } 2137 } 2138 2139 if ((SCS1.ReferenceBinding || SCS1.CopyConstructor) && 2140 (SCS2.ReferenceBinding || SCS2.CopyConstructor) && 2141 SCS1.Second == ICK_Derived_To_Base) { 2142 // -- conversion of C to B is better than conversion of C to A, 2143 // -- binding of an expression of type C to a reference of type 2144 // B& is better than binding an expression of type C to a 2145 // reference of type A&, 2146 if (Context.hasSameUnqualifiedType(FromType1, FromType2) && 2147 !Context.hasSameUnqualifiedType(ToType1, ToType2)) { 2148 if (IsDerivedFrom(ToType1, ToType2)) 2149 return ImplicitConversionSequence::Better; 2150 else if (IsDerivedFrom(ToType2, ToType1)) 2151 return ImplicitConversionSequence::Worse; 2152 } 2153 2154 // -- conversion of B to A is better than conversion of C to A. 2155 // -- binding of an expression of type B to a reference of type 2156 // A& is better than binding an expression of type C to a 2157 // reference of type A&, 2158 if (!Context.hasSameUnqualifiedType(FromType1, FromType2) && 2159 Context.hasSameUnqualifiedType(ToType1, ToType2)) { 2160 if (IsDerivedFrom(FromType2, FromType1)) 2161 return ImplicitConversionSequence::Better; 2162 else if (IsDerivedFrom(FromType1, FromType2)) 2163 return ImplicitConversionSequence::Worse; 2164 } 2165 } 2166 2167 return ImplicitConversionSequence::Indistinguishable; 2168} 2169 2170/// TryCopyInitialization - Try to copy-initialize a value of type 2171/// ToType from the expression From. Return the implicit conversion 2172/// sequence required to pass this argument, which may be a bad 2173/// conversion sequence (meaning that the argument cannot be passed to 2174/// a parameter of this type). If @p SuppressUserConversions, then we 2175/// do not permit any user-defined conversion sequences. If @p ForceRValue, 2176/// then we treat @p From as an rvalue, even if it is an lvalue. 2177ImplicitConversionSequence 2178Sema::TryCopyInitialization(Expr *From, QualType ToType, 2179 bool SuppressUserConversions, bool ForceRValue, 2180 bool InOverloadResolution) { 2181 if (ToType->isReferenceType()) { 2182 ImplicitConversionSequence ICS; 2183 ICS.setBad(BadConversionSequence::no_conversion, From, ToType); 2184 CheckReferenceInit(From, ToType, 2185 /*FIXME:*/From->getLocStart(), 2186 SuppressUserConversions, 2187 /*AllowExplicit=*/false, 2188 ForceRValue, 2189 &ICS); 2190 return ICS; 2191 } else { 2192 return TryImplicitConversion(From, ToType, 2193 SuppressUserConversions, 2194 /*AllowExplicit=*/false, 2195 ForceRValue, 2196 InOverloadResolution); 2197 } 2198} 2199 2200/// PerformCopyInitialization - Copy-initialize an object of type @p ToType with 2201/// the expression @p From. Returns true (and emits a diagnostic) if there was 2202/// an error, returns false if the initialization succeeded. Elidable should 2203/// be true when the copy may be elided (C++ 12.8p15). Overload resolution works 2204/// differently in C++0x for this case. 2205bool Sema::PerformCopyInitialization(Expr *&From, QualType ToType, 2206 AssignmentAction Action, bool Elidable) { 2207 if (!getLangOptions().CPlusPlus) { 2208 // In C, argument passing is the same as performing an assignment. 2209 QualType FromType = From->getType(); 2210 2211 AssignConvertType ConvTy = 2212 CheckSingleAssignmentConstraints(ToType, From); 2213 if (ConvTy != Compatible && 2214 CheckTransparentUnionArgumentConstraints(ToType, From) == Compatible) 2215 ConvTy = Compatible; 2216 2217 return DiagnoseAssignmentResult(ConvTy, From->getLocStart(), ToType, 2218 FromType, From, Action); 2219 } 2220 2221 if (ToType->isReferenceType()) 2222 return CheckReferenceInit(From, ToType, 2223 /*FIXME:*/From->getLocStart(), 2224 /*SuppressUserConversions=*/false, 2225 /*AllowExplicit=*/false, 2226 /*ForceRValue=*/false); 2227 2228 if (!PerformImplicitConversion(From, ToType, Action, 2229 /*AllowExplicit=*/false, Elidable)) 2230 return false; 2231 if (!DiagnoseMultipleUserDefinedConversion(From, ToType)) 2232 return Diag(From->getSourceRange().getBegin(), 2233 diag::err_typecheck_convert_incompatible) 2234 << ToType << From->getType() << Action << From->getSourceRange(); 2235 return true; 2236} 2237 2238/// TryObjectArgumentInitialization - Try to initialize the object 2239/// parameter of the given member function (@c Method) from the 2240/// expression @p From. 2241ImplicitConversionSequence 2242Sema::TryObjectArgumentInitialization(QualType OrigFromType, 2243 CXXMethodDecl *Method, 2244 CXXRecordDecl *ActingContext) { 2245 QualType ClassType = Context.getTypeDeclType(ActingContext); 2246 // [class.dtor]p2: A destructor can be invoked for a const, volatile or 2247 // const volatile object. 2248 unsigned Quals = isa<CXXDestructorDecl>(Method) ? 2249 Qualifiers::Const | Qualifiers::Volatile : Method->getTypeQualifiers(); 2250 QualType ImplicitParamType = Context.getCVRQualifiedType(ClassType, Quals); 2251 2252 // Set up the conversion sequence as a "bad" conversion, to allow us 2253 // to exit early. 2254 ImplicitConversionSequence ICS; 2255 2256 // We need to have an object of class type. 2257 QualType FromType = OrigFromType; 2258 if (const PointerType *PT = FromType->getAs<PointerType>()) 2259 FromType = PT->getPointeeType(); 2260 2261 assert(FromType->isRecordType()); 2262 2263 // The implicit object parameter is has the type "reference to cv X", 2264 // where X is the class of which the function is a member 2265 // (C++ [over.match.funcs]p4). However, when finding an implicit 2266 // conversion sequence for the argument, we are not allowed to 2267 // create temporaries or perform user-defined conversions 2268 // (C++ [over.match.funcs]p5). We perform a simplified version of 2269 // reference binding here, that allows class rvalues to bind to 2270 // non-constant references. 2271 2272 // First check the qualifiers. We don't care about lvalue-vs-rvalue 2273 // with the implicit object parameter (C++ [over.match.funcs]p5). 2274 QualType FromTypeCanon = Context.getCanonicalType(FromType); 2275 if (ImplicitParamType.getCVRQualifiers() 2276 != FromTypeCanon.getLocalCVRQualifiers() && 2277 !ImplicitParamType.isAtLeastAsQualifiedAs(FromTypeCanon)) { 2278 ICS.setBad(BadConversionSequence::bad_qualifiers, 2279 OrigFromType, ImplicitParamType); 2280 return ICS; 2281 } 2282 2283 // Check that we have either the same type or a derived type. It 2284 // affects the conversion rank. 2285 QualType ClassTypeCanon = Context.getCanonicalType(ClassType); 2286 ImplicitConversionKind SecondKind; 2287 if (ClassTypeCanon == FromTypeCanon.getLocalUnqualifiedType()) { 2288 SecondKind = ICK_Identity; 2289 } else if (IsDerivedFrom(FromType, ClassType)) 2290 SecondKind = ICK_Derived_To_Base; 2291 else { 2292 ICS.setBad(BadConversionSequence::unrelated_class, 2293 FromType, ImplicitParamType); 2294 return ICS; 2295 } 2296 2297 // Success. Mark this as a reference binding. 2298 ICS.setStandard(); 2299 ICS.Standard.setAsIdentityConversion(); 2300 ICS.Standard.Second = SecondKind; 2301 ICS.Standard.setFromType(FromType); 2302 ICS.Standard.setAllToTypes(ImplicitParamType); 2303 ICS.Standard.ReferenceBinding = true; 2304 ICS.Standard.DirectBinding = true; 2305 ICS.Standard.RRefBinding = false; 2306 return ICS; 2307} 2308 2309/// PerformObjectArgumentInitialization - Perform initialization of 2310/// the implicit object parameter for the given Method with the given 2311/// expression. 2312bool 2313Sema::PerformObjectArgumentInitialization(Expr *&From, 2314 NestedNameSpecifier *Qualifier, 2315 CXXMethodDecl *Method) { 2316 QualType FromRecordType, DestType; 2317 QualType ImplicitParamRecordType = 2318 Method->getThisType(Context)->getAs<PointerType>()->getPointeeType(); 2319 2320 if (const PointerType *PT = From->getType()->getAs<PointerType>()) { 2321 FromRecordType = PT->getPointeeType(); 2322 DestType = Method->getThisType(Context); 2323 } else { 2324 FromRecordType = From->getType(); 2325 DestType = ImplicitParamRecordType; 2326 } 2327 2328 // Note that we always use the true parent context when performing 2329 // the actual argument initialization. 2330 ImplicitConversionSequence ICS 2331 = TryObjectArgumentInitialization(From->getType(), Method, 2332 Method->getParent()); 2333 if (ICS.isBad()) 2334 return Diag(From->getSourceRange().getBegin(), 2335 diag::err_implicit_object_parameter_init) 2336 << ImplicitParamRecordType << FromRecordType << From->getSourceRange(); 2337 2338 if (ICS.Standard.Second == ICK_Derived_To_Base) 2339 return PerformObjectMemberConversion(From, Qualifier, Method); 2340 2341 if (!Context.hasSameType(From->getType(), DestType)) 2342 ImpCastExprToType(From, DestType, CastExpr::CK_NoOp, 2343 /*isLvalue=*/!From->getType()->getAs<PointerType>()); 2344 return false; 2345} 2346 2347/// TryContextuallyConvertToBool - Attempt to contextually convert the 2348/// expression From to bool (C++0x [conv]p3). 2349ImplicitConversionSequence Sema::TryContextuallyConvertToBool(Expr *From) { 2350 return TryImplicitConversion(From, Context.BoolTy, 2351 // FIXME: Are these flags correct? 2352 /*SuppressUserConversions=*/false, 2353 /*AllowExplicit=*/true, 2354 /*ForceRValue=*/false, 2355 /*InOverloadResolution=*/false); 2356} 2357 2358/// PerformContextuallyConvertToBool - Perform a contextual conversion 2359/// of the expression From to bool (C++0x [conv]p3). 2360bool Sema::PerformContextuallyConvertToBool(Expr *&From) { 2361 ImplicitConversionSequence ICS = TryContextuallyConvertToBool(From); 2362 if (!ICS.isBad()) 2363 return PerformImplicitConversion(From, Context.BoolTy, ICS, AA_Converting); 2364 2365 if (!DiagnoseMultipleUserDefinedConversion(From, Context.BoolTy)) 2366 return Diag(From->getSourceRange().getBegin(), 2367 diag::err_typecheck_bool_condition) 2368 << From->getType() << From->getSourceRange(); 2369 return true; 2370} 2371 2372/// AddOverloadCandidate - Adds the given function to the set of 2373/// candidate functions, using the given function call arguments. If 2374/// @p SuppressUserConversions, then don't allow user-defined 2375/// conversions via constructors or conversion operators. 2376/// If @p ForceRValue, treat all arguments as rvalues. This is a slightly 2377/// hacky way to implement the overloading rules for elidable copy 2378/// initialization in C++0x (C++0x 12.8p15). 2379/// 2380/// \para PartialOverloading true if we are performing "partial" overloading 2381/// based on an incomplete set of function arguments. This feature is used by 2382/// code completion. 2383void 2384Sema::AddOverloadCandidate(FunctionDecl *Function, 2385 AccessSpecifier Access, 2386 Expr **Args, unsigned NumArgs, 2387 OverloadCandidateSet& CandidateSet, 2388 bool SuppressUserConversions, 2389 bool ForceRValue, 2390 bool PartialOverloading) { 2391 const FunctionProtoType* Proto 2392 = dyn_cast<FunctionProtoType>(Function->getType()->getAs<FunctionType>()); 2393 assert(Proto && "Functions without a prototype cannot be overloaded"); 2394 assert(!Function->getDescribedFunctionTemplate() && 2395 "Use AddTemplateOverloadCandidate for function templates"); 2396 2397 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Function)) { 2398 if (!isa<CXXConstructorDecl>(Method)) { 2399 // If we get here, it's because we're calling a member function 2400 // that is named without a member access expression (e.g., 2401 // "this->f") that was either written explicitly or created 2402 // implicitly. This can happen with a qualified call to a member 2403 // function, e.g., X::f(). We use an empty type for the implied 2404 // object argument (C++ [over.call.func]p3), and the acting context 2405 // is irrelevant. 2406 AddMethodCandidate(Method, Access, Method->getParent(), 2407 QualType(), Args, NumArgs, CandidateSet, 2408 SuppressUserConversions, ForceRValue); 2409 return; 2410 } 2411 // We treat a constructor like a non-member function, since its object 2412 // argument doesn't participate in overload resolution. 2413 } 2414 2415 if (!CandidateSet.isNewCandidate(Function)) 2416 return; 2417 2418 // Overload resolution is always an unevaluated context. 2419 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 2420 2421 if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(Function)){ 2422 // C++ [class.copy]p3: 2423 // A member function template is never instantiated to perform the copy 2424 // of a class object to an object of its class type. 2425 QualType ClassType = Context.getTypeDeclType(Constructor->getParent()); 2426 if (NumArgs == 1 && 2427 Constructor->isCopyConstructorLikeSpecialization() && 2428 (Context.hasSameUnqualifiedType(ClassType, Args[0]->getType()) || 2429 IsDerivedFrom(Args[0]->getType(), ClassType))) 2430 return; 2431 } 2432 2433 // Add this candidate 2434 CandidateSet.push_back(OverloadCandidate()); 2435 OverloadCandidate& Candidate = CandidateSet.back(); 2436 Candidate.Function = Function; 2437 Candidate.Access = Access; 2438 Candidate.Viable = true; 2439 Candidate.IsSurrogate = false; 2440 Candidate.IgnoreObjectArgument = false; 2441 2442 unsigned NumArgsInProto = Proto->getNumArgs(); 2443 2444 // (C++ 13.3.2p2): A candidate function having fewer than m 2445 // parameters is viable only if it has an ellipsis in its parameter 2446 // list (8.3.5). 2447 if ((NumArgs + (PartialOverloading && NumArgs)) > NumArgsInProto && 2448 !Proto->isVariadic()) { 2449 Candidate.Viable = false; 2450 Candidate.FailureKind = ovl_fail_too_many_arguments; 2451 return; 2452 } 2453 2454 // (C++ 13.3.2p2): A candidate function having more than m parameters 2455 // is viable only if the (m+1)st parameter has a default argument 2456 // (8.3.6). For the purposes of overload resolution, the 2457 // parameter list is truncated on the right, so that there are 2458 // exactly m parameters. 2459 unsigned MinRequiredArgs = Function->getMinRequiredArguments(); 2460 if (NumArgs < MinRequiredArgs && !PartialOverloading) { 2461 // Not enough arguments. 2462 Candidate.Viable = false; 2463 Candidate.FailureKind = ovl_fail_too_few_arguments; 2464 return; 2465 } 2466 2467 // Determine the implicit conversion sequences for each of the 2468 // arguments. 2469 Candidate.Conversions.resize(NumArgs); 2470 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2471 if (ArgIdx < NumArgsInProto) { 2472 // (C++ 13.3.2p3): for F to be a viable function, there shall 2473 // exist for each argument an implicit conversion sequence 2474 // (13.3.3.1) that converts that argument to the corresponding 2475 // parameter of F. 2476 QualType ParamType = Proto->getArgType(ArgIdx); 2477 Candidate.Conversions[ArgIdx] 2478 = TryCopyInitialization(Args[ArgIdx], ParamType, 2479 SuppressUserConversions, ForceRValue, 2480 /*InOverloadResolution=*/true); 2481 if (Candidate.Conversions[ArgIdx].isBad()) { 2482 Candidate.Viable = false; 2483 Candidate.FailureKind = ovl_fail_bad_conversion; 2484 break; 2485 } 2486 } else { 2487 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2488 // argument for which there is no corresponding parameter is 2489 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2490 Candidate.Conversions[ArgIdx].setEllipsis(); 2491 } 2492 } 2493} 2494 2495/// \brief Add all of the function declarations in the given function set to 2496/// the overload canddiate set. 2497void Sema::AddFunctionCandidates(const UnresolvedSetImpl &Fns, 2498 Expr **Args, unsigned NumArgs, 2499 OverloadCandidateSet& CandidateSet, 2500 bool SuppressUserConversions) { 2501 for (UnresolvedSetIterator F = Fns.begin(), E = Fns.end(); F != E; ++F) { 2502 // FIXME: using declarations 2503 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*F)) { 2504 if (isa<CXXMethodDecl>(FD) && !cast<CXXMethodDecl>(FD)->isStatic()) 2505 AddMethodCandidate(cast<CXXMethodDecl>(FD), F.getAccess(), 2506 cast<CXXMethodDecl>(FD)->getParent(), 2507 Args[0]->getType(), Args + 1, NumArgs - 1, 2508 CandidateSet, SuppressUserConversions); 2509 else 2510 AddOverloadCandidate(FD, AS_none, Args, NumArgs, CandidateSet, 2511 SuppressUserConversions); 2512 } else { 2513 FunctionTemplateDecl *FunTmpl = cast<FunctionTemplateDecl>(*F); 2514 if (isa<CXXMethodDecl>(FunTmpl->getTemplatedDecl()) && 2515 !cast<CXXMethodDecl>(FunTmpl->getTemplatedDecl())->isStatic()) 2516 AddMethodTemplateCandidate(FunTmpl, F.getAccess(), 2517 cast<CXXRecordDecl>(FunTmpl->getDeclContext()), 2518 /*FIXME: explicit args */ 0, 2519 Args[0]->getType(), Args + 1, NumArgs - 1, 2520 CandidateSet, 2521 SuppressUserConversions); 2522 else 2523 AddTemplateOverloadCandidate(FunTmpl, AS_none, 2524 /*FIXME: explicit args */ 0, 2525 Args, NumArgs, CandidateSet, 2526 SuppressUserConversions); 2527 } 2528 } 2529} 2530 2531/// AddMethodCandidate - Adds a named decl (which is some kind of 2532/// method) as a method candidate to the given overload set. 2533void Sema::AddMethodCandidate(NamedDecl *Decl, 2534 AccessSpecifier Access, 2535 QualType ObjectType, 2536 Expr **Args, unsigned NumArgs, 2537 OverloadCandidateSet& CandidateSet, 2538 bool SuppressUserConversions, bool ForceRValue) { 2539 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(Decl->getDeclContext()); 2540 2541 if (isa<UsingShadowDecl>(Decl)) 2542 Decl = cast<UsingShadowDecl>(Decl)->getTargetDecl(); 2543 2544 if (FunctionTemplateDecl *TD = dyn_cast<FunctionTemplateDecl>(Decl)) { 2545 assert(isa<CXXMethodDecl>(TD->getTemplatedDecl()) && 2546 "Expected a member function template"); 2547 AddMethodTemplateCandidate(TD, Access, ActingContext, /*ExplicitArgs*/ 0, 2548 ObjectType, Args, NumArgs, 2549 CandidateSet, 2550 SuppressUserConversions, 2551 ForceRValue); 2552 } else { 2553 AddMethodCandidate(cast<CXXMethodDecl>(Decl), Access, ActingContext, 2554 ObjectType, Args, NumArgs, 2555 CandidateSet, SuppressUserConversions, ForceRValue); 2556 } 2557} 2558 2559/// AddMethodCandidate - Adds the given C++ member function to the set 2560/// of candidate functions, using the given function call arguments 2561/// and the object argument (@c Object). For example, in a call 2562/// @c o.f(a1,a2), @c Object will contain @c o and @c Args will contain 2563/// both @c a1 and @c a2. If @p SuppressUserConversions, then don't 2564/// allow user-defined conversions via constructors or conversion 2565/// operators. If @p ForceRValue, treat all arguments as rvalues. This is 2566/// a slightly hacky way to implement the overloading rules for elidable copy 2567/// initialization in C++0x (C++0x 12.8p15). 2568void 2569Sema::AddMethodCandidate(CXXMethodDecl *Method, AccessSpecifier Access, 2570 CXXRecordDecl *ActingContext, QualType ObjectType, 2571 Expr **Args, unsigned NumArgs, 2572 OverloadCandidateSet& CandidateSet, 2573 bool SuppressUserConversions, bool ForceRValue) { 2574 const FunctionProtoType* Proto 2575 = dyn_cast<FunctionProtoType>(Method->getType()->getAs<FunctionType>()); 2576 assert(Proto && "Methods without a prototype cannot be overloaded"); 2577 assert(!isa<CXXConstructorDecl>(Method) && 2578 "Use AddOverloadCandidate for constructors"); 2579 2580 if (!CandidateSet.isNewCandidate(Method)) 2581 return; 2582 2583 // Overload resolution is always an unevaluated context. 2584 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 2585 2586 // Add this candidate 2587 CandidateSet.push_back(OverloadCandidate()); 2588 OverloadCandidate& Candidate = CandidateSet.back(); 2589 Candidate.Function = Method; 2590 Candidate.Access = Access; 2591 Candidate.IsSurrogate = false; 2592 Candidate.IgnoreObjectArgument = false; 2593 2594 unsigned NumArgsInProto = Proto->getNumArgs(); 2595 2596 // (C++ 13.3.2p2): A candidate function having fewer than m 2597 // parameters is viable only if it has an ellipsis in its parameter 2598 // list (8.3.5). 2599 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 2600 Candidate.Viable = false; 2601 Candidate.FailureKind = ovl_fail_too_many_arguments; 2602 return; 2603 } 2604 2605 // (C++ 13.3.2p2): A candidate function having more than m parameters 2606 // is viable only if the (m+1)st parameter has a default argument 2607 // (8.3.6). For the purposes of overload resolution, the 2608 // parameter list is truncated on the right, so that there are 2609 // exactly m parameters. 2610 unsigned MinRequiredArgs = Method->getMinRequiredArguments(); 2611 if (NumArgs < MinRequiredArgs) { 2612 // Not enough arguments. 2613 Candidate.Viable = false; 2614 Candidate.FailureKind = ovl_fail_too_few_arguments; 2615 return; 2616 } 2617 2618 Candidate.Viable = true; 2619 Candidate.Conversions.resize(NumArgs + 1); 2620 2621 if (Method->isStatic() || ObjectType.isNull()) 2622 // The implicit object argument is ignored. 2623 Candidate.IgnoreObjectArgument = true; 2624 else { 2625 // Determine the implicit conversion sequence for the object 2626 // parameter. 2627 Candidate.Conversions[0] 2628 = TryObjectArgumentInitialization(ObjectType, Method, ActingContext); 2629 if (Candidate.Conversions[0].isBad()) { 2630 Candidate.Viable = false; 2631 Candidate.FailureKind = ovl_fail_bad_conversion; 2632 return; 2633 } 2634 } 2635 2636 // Determine the implicit conversion sequences for each of the 2637 // arguments. 2638 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2639 if (ArgIdx < NumArgsInProto) { 2640 // (C++ 13.3.2p3): for F to be a viable function, there shall 2641 // exist for each argument an implicit conversion sequence 2642 // (13.3.3.1) that converts that argument to the corresponding 2643 // parameter of F. 2644 QualType ParamType = Proto->getArgType(ArgIdx); 2645 Candidate.Conversions[ArgIdx + 1] 2646 = TryCopyInitialization(Args[ArgIdx], ParamType, 2647 SuppressUserConversions, ForceRValue, 2648 /*InOverloadResolution=*/true); 2649 if (Candidate.Conversions[ArgIdx + 1].isBad()) { 2650 Candidate.Viable = false; 2651 Candidate.FailureKind = ovl_fail_bad_conversion; 2652 break; 2653 } 2654 } else { 2655 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2656 // argument for which there is no corresponding parameter is 2657 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2658 Candidate.Conversions[ArgIdx + 1].setEllipsis(); 2659 } 2660 } 2661} 2662 2663/// \brief Add a C++ member function template as a candidate to the candidate 2664/// set, using template argument deduction to produce an appropriate member 2665/// function template specialization. 2666void 2667Sema::AddMethodTemplateCandidate(FunctionTemplateDecl *MethodTmpl, 2668 AccessSpecifier Access, 2669 CXXRecordDecl *ActingContext, 2670 const TemplateArgumentListInfo *ExplicitTemplateArgs, 2671 QualType ObjectType, 2672 Expr **Args, unsigned NumArgs, 2673 OverloadCandidateSet& CandidateSet, 2674 bool SuppressUserConversions, 2675 bool ForceRValue) { 2676 if (!CandidateSet.isNewCandidate(MethodTmpl)) 2677 return; 2678 2679 // C++ [over.match.funcs]p7: 2680 // In each case where a candidate is a function template, candidate 2681 // function template specializations are generated using template argument 2682 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 2683 // candidate functions in the usual way.113) A given name can refer to one 2684 // or more function templates and also to a set of overloaded non-template 2685 // functions. In such a case, the candidate functions generated from each 2686 // function template are combined with the set of non-template candidate 2687 // functions. 2688 TemplateDeductionInfo Info(Context, CandidateSet.getLocation()); 2689 FunctionDecl *Specialization = 0; 2690 if (TemplateDeductionResult Result 2691 = DeduceTemplateArguments(MethodTmpl, ExplicitTemplateArgs, 2692 Args, NumArgs, Specialization, Info)) { 2693 // FIXME: Record what happened with template argument deduction, so 2694 // that we can give the user a beautiful diagnostic. 2695 (void)Result; 2696 return; 2697 } 2698 2699 // Add the function template specialization produced by template argument 2700 // deduction as a candidate. 2701 assert(Specialization && "Missing member function template specialization?"); 2702 assert(isa<CXXMethodDecl>(Specialization) && 2703 "Specialization is not a member function?"); 2704 AddMethodCandidate(cast<CXXMethodDecl>(Specialization), Access, 2705 ActingContext, ObjectType, Args, NumArgs, 2706 CandidateSet, SuppressUserConversions, ForceRValue); 2707} 2708 2709/// \brief Add a C++ function template specialization as a candidate 2710/// in the candidate set, using template argument deduction to produce 2711/// an appropriate function template specialization. 2712void 2713Sema::AddTemplateOverloadCandidate(FunctionTemplateDecl *FunctionTemplate, 2714 AccessSpecifier Access, 2715 const TemplateArgumentListInfo *ExplicitTemplateArgs, 2716 Expr **Args, unsigned NumArgs, 2717 OverloadCandidateSet& CandidateSet, 2718 bool SuppressUserConversions, 2719 bool ForceRValue) { 2720 if (!CandidateSet.isNewCandidate(FunctionTemplate)) 2721 return; 2722 2723 // C++ [over.match.funcs]p7: 2724 // In each case where a candidate is a function template, candidate 2725 // function template specializations are generated using template argument 2726 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 2727 // candidate functions in the usual way.113) A given name can refer to one 2728 // or more function templates and also to a set of overloaded non-template 2729 // functions. In such a case, the candidate functions generated from each 2730 // function template are combined with the set of non-template candidate 2731 // functions. 2732 TemplateDeductionInfo Info(Context, CandidateSet.getLocation()); 2733 FunctionDecl *Specialization = 0; 2734 if (TemplateDeductionResult Result 2735 = DeduceTemplateArguments(FunctionTemplate, ExplicitTemplateArgs, 2736 Args, NumArgs, Specialization, Info)) { 2737 CandidateSet.push_back(OverloadCandidate()); 2738 OverloadCandidate &Candidate = CandidateSet.back(); 2739 Candidate.Function = FunctionTemplate->getTemplatedDecl(); 2740 Candidate.Access = Access; 2741 Candidate.Viable = false; 2742 Candidate.FailureKind = ovl_fail_bad_deduction; 2743 Candidate.IsSurrogate = false; 2744 Candidate.IgnoreObjectArgument = false; 2745 2746 // TODO: record more information about failed template arguments 2747 Candidate.DeductionFailure.Result = Result; 2748 Candidate.DeductionFailure.TemplateParameter = Info.Param.getOpaqueValue(); 2749 return; 2750 } 2751 2752 // Add the function template specialization produced by template argument 2753 // deduction as a candidate. 2754 assert(Specialization && "Missing function template specialization?"); 2755 AddOverloadCandidate(Specialization, Access, Args, NumArgs, CandidateSet, 2756 SuppressUserConversions, ForceRValue); 2757} 2758 2759/// AddConversionCandidate - Add a C++ conversion function as a 2760/// candidate in the candidate set (C++ [over.match.conv], 2761/// C++ [over.match.copy]). From is the expression we're converting from, 2762/// and ToType is the type that we're eventually trying to convert to 2763/// (which may or may not be the same type as the type that the 2764/// conversion function produces). 2765void 2766Sema::AddConversionCandidate(CXXConversionDecl *Conversion, 2767 AccessSpecifier Access, 2768 CXXRecordDecl *ActingContext, 2769 Expr *From, QualType ToType, 2770 OverloadCandidateSet& CandidateSet) { 2771 assert(!Conversion->getDescribedFunctionTemplate() && 2772 "Conversion function templates use AddTemplateConversionCandidate"); 2773 2774 if (!CandidateSet.isNewCandidate(Conversion)) 2775 return; 2776 2777 // Overload resolution is always an unevaluated context. 2778 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 2779 2780 // Add this candidate 2781 CandidateSet.push_back(OverloadCandidate()); 2782 OverloadCandidate& Candidate = CandidateSet.back(); 2783 Candidate.Function = Conversion; 2784 Candidate.Access = Access; 2785 Candidate.IsSurrogate = false; 2786 Candidate.IgnoreObjectArgument = false; 2787 Candidate.FinalConversion.setAsIdentityConversion(); 2788 Candidate.FinalConversion.setFromType(Conversion->getConversionType()); 2789 Candidate.FinalConversion.setAllToTypes(ToType); 2790 2791 // Determine the implicit conversion sequence for the implicit 2792 // object parameter. 2793 Candidate.Viable = true; 2794 Candidate.Conversions.resize(1); 2795 Candidate.Conversions[0] 2796 = TryObjectArgumentInitialization(From->getType(), Conversion, 2797 ActingContext); 2798 // Conversion functions to a different type in the base class is visible in 2799 // the derived class. So, a derived to base conversion should not participate 2800 // in overload resolution. 2801 if (Candidate.Conversions[0].Standard.Second == ICK_Derived_To_Base) 2802 Candidate.Conversions[0].Standard.Second = ICK_Identity; 2803 if (Candidate.Conversions[0].isBad()) { 2804 Candidate.Viable = false; 2805 Candidate.FailureKind = ovl_fail_bad_conversion; 2806 return; 2807 } 2808 2809 // We won't go through a user-define type conversion function to convert a 2810 // derived to base as such conversions are given Conversion Rank. They only 2811 // go through a copy constructor. 13.3.3.1.2-p4 [over.ics.user] 2812 QualType FromCanon 2813 = Context.getCanonicalType(From->getType().getUnqualifiedType()); 2814 QualType ToCanon = Context.getCanonicalType(ToType).getUnqualifiedType(); 2815 if (FromCanon == ToCanon || IsDerivedFrom(FromCanon, ToCanon)) { 2816 Candidate.Viable = false; 2817 Candidate.FailureKind = ovl_fail_trivial_conversion; 2818 return; 2819 } 2820 2821 2822 // To determine what the conversion from the result of calling the 2823 // conversion function to the type we're eventually trying to 2824 // convert to (ToType), we need to synthesize a call to the 2825 // conversion function and attempt copy initialization from it. This 2826 // makes sure that we get the right semantics with respect to 2827 // lvalues/rvalues and the type. Fortunately, we can allocate this 2828 // call on the stack and we don't need its arguments to be 2829 // well-formed. 2830 DeclRefExpr ConversionRef(Conversion, Conversion->getType(), 2831 From->getLocStart()); 2832 ImplicitCastExpr ConversionFn(Context.getPointerType(Conversion->getType()), 2833 CastExpr::CK_FunctionToPointerDecay, 2834 &ConversionRef, false); 2835 2836 // Note that it is safe to allocate CallExpr on the stack here because 2837 // there are 0 arguments (i.e., nothing is allocated using ASTContext's 2838 // allocator). 2839 CallExpr Call(Context, &ConversionFn, 0, 0, 2840 Conversion->getConversionType().getNonReferenceType(), 2841 From->getLocStart()); 2842 ImplicitConversionSequence ICS = 2843 TryCopyInitialization(&Call, ToType, 2844 /*SuppressUserConversions=*/true, 2845 /*ForceRValue=*/false, 2846 /*InOverloadResolution=*/false); 2847 2848 switch (ICS.getKind()) { 2849 case ImplicitConversionSequence::StandardConversion: 2850 Candidate.FinalConversion = ICS.Standard; 2851 break; 2852 2853 case ImplicitConversionSequence::BadConversion: 2854 Candidate.Viable = false; 2855 Candidate.FailureKind = ovl_fail_bad_final_conversion; 2856 break; 2857 2858 default: 2859 assert(false && 2860 "Can only end up with a standard conversion sequence or failure"); 2861 } 2862} 2863 2864/// \brief Adds a conversion function template specialization 2865/// candidate to the overload set, using template argument deduction 2866/// to deduce the template arguments of the conversion function 2867/// template from the type that we are converting to (C++ 2868/// [temp.deduct.conv]). 2869void 2870Sema::AddTemplateConversionCandidate(FunctionTemplateDecl *FunctionTemplate, 2871 AccessSpecifier Access, 2872 CXXRecordDecl *ActingDC, 2873 Expr *From, QualType ToType, 2874 OverloadCandidateSet &CandidateSet) { 2875 assert(isa<CXXConversionDecl>(FunctionTemplate->getTemplatedDecl()) && 2876 "Only conversion function templates permitted here"); 2877 2878 if (!CandidateSet.isNewCandidate(FunctionTemplate)) 2879 return; 2880 2881 TemplateDeductionInfo Info(Context, CandidateSet.getLocation()); 2882 CXXConversionDecl *Specialization = 0; 2883 if (TemplateDeductionResult Result 2884 = DeduceTemplateArguments(FunctionTemplate, ToType, 2885 Specialization, Info)) { 2886 // FIXME: Record what happened with template argument deduction, so 2887 // that we can give the user a beautiful diagnostic. 2888 (void)Result; 2889 return; 2890 } 2891 2892 // Add the conversion function template specialization produced by 2893 // template argument deduction as a candidate. 2894 assert(Specialization && "Missing function template specialization?"); 2895 AddConversionCandidate(Specialization, Access, ActingDC, From, ToType, 2896 CandidateSet); 2897} 2898 2899/// AddSurrogateCandidate - Adds a "surrogate" candidate function that 2900/// converts the given @c Object to a function pointer via the 2901/// conversion function @c Conversion, and then attempts to call it 2902/// with the given arguments (C++ [over.call.object]p2-4). Proto is 2903/// the type of function that we'll eventually be calling. 2904void Sema::AddSurrogateCandidate(CXXConversionDecl *Conversion, 2905 AccessSpecifier Access, 2906 CXXRecordDecl *ActingContext, 2907 const FunctionProtoType *Proto, 2908 QualType ObjectType, 2909 Expr **Args, unsigned NumArgs, 2910 OverloadCandidateSet& CandidateSet) { 2911 if (!CandidateSet.isNewCandidate(Conversion)) 2912 return; 2913 2914 // Overload resolution is always an unevaluated context. 2915 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 2916 2917 CandidateSet.push_back(OverloadCandidate()); 2918 OverloadCandidate& Candidate = CandidateSet.back(); 2919 Candidate.Function = 0; 2920 Candidate.Access = Access; 2921 Candidate.Surrogate = Conversion; 2922 Candidate.Viable = true; 2923 Candidate.IsSurrogate = true; 2924 Candidate.IgnoreObjectArgument = false; 2925 Candidate.Conversions.resize(NumArgs + 1); 2926 2927 // Determine the implicit conversion sequence for the implicit 2928 // object parameter. 2929 ImplicitConversionSequence ObjectInit 2930 = TryObjectArgumentInitialization(ObjectType, Conversion, ActingContext); 2931 if (ObjectInit.isBad()) { 2932 Candidate.Viable = false; 2933 Candidate.FailureKind = ovl_fail_bad_conversion; 2934 Candidate.Conversions[0] = ObjectInit; 2935 return; 2936 } 2937 2938 // The first conversion is actually a user-defined conversion whose 2939 // first conversion is ObjectInit's standard conversion (which is 2940 // effectively a reference binding). Record it as such. 2941 Candidate.Conversions[0].setUserDefined(); 2942 Candidate.Conversions[0].UserDefined.Before = ObjectInit.Standard; 2943 Candidate.Conversions[0].UserDefined.EllipsisConversion = false; 2944 Candidate.Conversions[0].UserDefined.ConversionFunction = Conversion; 2945 Candidate.Conversions[0].UserDefined.After 2946 = Candidate.Conversions[0].UserDefined.Before; 2947 Candidate.Conversions[0].UserDefined.After.setAsIdentityConversion(); 2948 2949 // Find the 2950 unsigned NumArgsInProto = Proto->getNumArgs(); 2951 2952 // (C++ 13.3.2p2): A candidate function having fewer than m 2953 // parameters is viable only if it has an ellipsis in its parameter 2954 // list (8.3.5). 2955 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 2956 Candidate.Viable = false; 2957 Candidate.FailureKind = ovl_fail_too_many_arguments; 2958 return; 2959 } 2960 2961 // Function types don't have any default arguments, so just check if 2962 // we have enough arguments. 2963 if (NumArgs < NumArgsInProto) { 2964 // Not enough arguments. 2965 Candidate.Viable = false; 2966 Candidate.FailureKind = ovl_fail_too_few_arguments; 2967 return; 2968 } 2969 2970 // Determine the implicit conversion sequences for each of the 2971 // arguments. 2972 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2973 if (ArgIdx < NumArgsInProto) { 2974 // (C++ 13.3.2p3): for F to be a viable function, there shall 2975 // exist for each argument an implicit conversion sequence 2976 // (13.3.3.1) that converts that argument to the corresponding 2977 // parameter of F. 2978 QualType ParamType = Proto->getArgType(ArgIdx); 2979 Candidate.Conversions[ArgIdx + 1] 2980 = TryCopyInitialization(Args[ArgIdx], ParamType, 2981 /*SuppressUserConversions=*/false, 2982 /*ForceRValue=*/false, 2983 /*InOverloadResolution=*/false); 2984 if (Candidate.Conversions[ArgIdx + 1].isBad()) { 2985 Candidate.Viable = false; 2986 Candidate.FailureKind = ovl_fail_bad_conversion; 2987 break; 2988 } 2989 } else { 2990 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2991 // argument for which there is no corresponding parameter is 2992 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2993 Candidate.Conversions[ArgIdx + 1].setEllipsis(); 2994 } 2995 } 2996} 2997 2998// FIXME: This will eventually be removed, once we've migrated all of the 2999// operator overloading logic over to the scheme used by binary operators, which 3000// works for template instantiation. 3001void Sema::AddOperatorCandidates(OverloadedOperatorKind Op, Scope *S, 3002 SourceLocation OpLoc, 3003 Expr **Args, unsigned NumArgs, 3004 OverloadCandidateSet& CandidateSet, 3005 SourceRange OpRange) { 3006 UnresolvedSet<16> Fns; 3007 3008 QualType T1 = Args[0]->getType(); 3009 QualType T2; 3010 if (NumArgs > 1) 3011 T2 = Args[1]->getType(); 3012 3013 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 3014 if (S) 3015 LookupOverloadedOperatorName(Op, S, T1, T2, Fns); 3016 AddFunctionCandidates(Fns, Args, NumArgs, CandidateSet, false); 3017 AddArgumentDependentLookupCandidates(OpName, false, Args, NumArgs, 0, 3018 CandidateSet); 3019 AddMemberOperatorCandidates(Op, OpLoc, Args, NumArgs, CandidateSet, OpRange); 3020 AddBuiltinOperatorCandidates(Op, OpLoc, Args, NumArgs, CandidateSet); 3021} 3022 3023/// \brief Add overload candidates for overloaded operators that are 3024/// member functions. 3025/// 3026/// Add the overloaded operator candidates that are member functions 3027/// for the operator Op that was used in an operator expression such 3028/// as "x Op y". , Args/NumArgs provides the operator arguments, and 3029/// CandidateSet will store the added overload candidates. (C++ 3030/// [over.match.oper]). 3031void Sema::AddMemberOperatorCandidates(OverloadedOperatorKind Op, 3032 SourceLocation OpLoc, 3033 Expr **Args, unsigned NumArgs, 3034 OverloadCandidateSet& CandidateSet, 3035 SourceRange OpRange) { 3036 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 3037 3038 // C++ [over.match.oper]p3: 3039 // For a unary operator @ with an operand of a type whose 3040 // cv-unqualified version is T1, and for a binary operator @ with 3041 // a left operand of a type whose cv-unqualified version is T1 and 3042 // a right operand of a type whose cv-unqualified version is T2, 3043 // three sets of candidate functions, designated member 3044 // candidates, non-member candidates and built-in candidates, are 3045 // constructed as follows: 3046 QualType T1 = Args[0]->getType(); 3047 QualType T2; 3048 if (NumArgs > 1) 3049 T2 = Args[1]->getType(); 3050 3051 // -- If T1 is a class type, the set of member candidates is the 3052 // result of the qualified lookup of T1::operator@ 3053 // (13.3.1.1.1); otherwise, the set of member candidates is 3054 // empty. 3055 if (const RecordType *T1Rec = T1->getAs<RecordType>()) { 3056 // Complete the type if it can be completed. Otherwise, we're done. 3057 if (RequireCompleteType(OpLoc, T1, PDiag())) 3058 return; 3059 3060 LookupResult Operators(*this, OpName, OpLoc, LookupOrdinaryName); 3061 LookupQualifiedName(Operators, T1Rec->getDecl()); 3062 Operators.suppressDiagnostics(); 3063 3064 for (LookupResult::iterator Oper = Operators.begin(), 3065 OperEnd = Operators.end(); 3066 Oper != OperEnd; 3067 ++Oper) 3068 AddMethodCandidate(*Oper, Oper.getAccess(), Args[0]->getType(), 3069 Args + 1, NumArgs - 1, CandidateSet, 3070 /* SuppressUserConversions = */ false); 3071 } 3072} 3073 3074/// AddBuiltinCandidate - Add a candidate for a built-in 3075/// operator. ResultTy and ParamTys are the result and parameter types 3076/// of the built-in candidate, respectively. Args and NumArgs are the 3077/// arguments being passed to the candidate. IsAssignmentOperator 3078/// should be true when this built-in candidate is an assignment 3079/// operator. NumContextualBoolArguments is the number of arguments 3080/// (at the beginning of the argument list) that will be contextually 3081/// converted to bool. 3082void Sema::AddBuiltinCandidate(QualType ResultTy, QualType *ParamTys, 3083 Expr **Args, unsigned NumArgs, 3084 OverloadCandidateSet& CandidateSet, 3085 bool IsAssignmentOperator, 3086 unsigned NumContextualBoolArguments) { 3087 // Overload resolution is always an unevaluated context. 3088 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 3089 3090 // Add this candidate 3091 CandidateSet.push_back(OverloadCandidate()); 3092 OverloadCandidate& Candidate = CandidateSet.back(); 3093 Candidate.Function = 0; 3094 Candidate.Access = AS_none; 3095 Candidate.IsSurrogate = false; 3096 Candidate.IgnoreObjectArgument = false; 3097 Candidate.BuiltinTypes.ResultTy = ResultTy; 3098 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 3099 Candidate.BuiltinTypes.ParamTypes[ArgIdx] = ParamTys[ArgIdx]; 3100 3101 // Determine the implicit conversion sequences for each of the 3102 // arguments. 3103 Candidate.Viable = true; 3104 Candidate.Conversions.resize(NumArgs); 3105 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 3106 // C++ [over.match.oper]p4: 3107 // For the built-in assignment operators, conversions of the 3108 // left operand are restricted as follows: 3109 // -- no temporaries are introduced to hold the left operand, and 3110 // -- no user-defined conversions are applied to the left 3111 // operand to achieve a type match with the left-most 3112 // parameter of a built-in candidate. 3113 // 3114 // We block these conversions by turning off user-defined 3115 // conversions, since that is the only way that initialization of 3116 // a reference to a non-class type can occur from something that 3117 // is not of the same type. 3118 if (ArgIdx < NumContextualBoolArguments) { 3119 assert(ParamTys[ArgIdx] == Context.BoolTy && 3120 "Contextual conversion to bool requires bool type"); 3121 Candidate.Conversions[ArgIdx] = TryContextuallyConvertToBool(Args[ArgIdx]); 3122 } else { 3123 Candidate.Conversions[ArgIdx] 3124 = TryCopyInitialization(Args[ArgIdx], ParamTys[ArgIdx], 3125 ArgIdx == 0 && IsAssignmentOperator, 3126 /*ForceRValue=*/false, 3127 /*InOverloadResolution=*/false); 3128 } 3129 if (Candidate.Conversions[ArgIdx].isBad()) { 3130 Candidate.Viable = false; 3131 Candidate.FailureKind = ovl_fail_bad_conversion; 3132 break; 3133 } 3134 } 3135} 3136 3137/// BuiltinCandidateTypeSet - A set of types that will be used for the 3138/// candidate operator functions for built-in operators (C++ 3139/// [over.built]). The types are separated into pointer types and 3140/// enumeration types. 3141class BuiltinCandidateTypeSet { 3142 /// TypeSet - A set of types. 3143 typedef llvm::SmallPtrSet<QualType, 8> TypeSet; 3144 3145 /// PointerTypes - The set of pointer types that will be used in the 3146 /// built-in candidates. 3147 TypeSet PointerTypes; 3148 3149 /// MemberPointerTypes - The set of member pointer types that will be 3150 /// used in the built-in candidates. 3151 TypeSet MemberPointerTypes; 3152 3153 /// EnumerationTypes - The set of enumeration types that will be 3154 /// used in the built-in candidates. 3155 TypeSet EnumerationTypes; 3156 3157 /// Sema - The semantic analysis instance where we are building the 3158 /// candidate type set. 3159 Sema &SemaRef; 3160 3161 /// Context - The AST context in which we will build the type sets. 3162 ASTContext &Context; 3163 3164 bool AddPointerWithMoreQualifiedTypeVariants(QualType Ty, 3165 const Qualifiers &VisibleQuals); 3166 bool AddMemberPointerWithMoreQualifiedTypeVariants(QualType Ty); 3167 3168public: 3169 /// iterator - Iterates through the types that are part of the set. 3170 typedef TypeSet::iterator iterator; 3171 3172 BuiltinCandidateTypeSet(Sema &SemaRef) 3173 : SemaRef(SemaRef), Context(SemaRef.Context) { } 3174 3175 void AddTypesConvertedFrom(QualType Ty, 3176 SourceLocation Loc, 3177 bool AllowUserConversions, 3178 bool AllowExplicitConversions, 3179 const Qualifiers &VisibleTypeConversionsQuals); 3180 3181 /// pointer_begin - First pointer type found; 3182 iterator pointer_begin() { return PointerTypes.begin(); } 3183 3184 /// pointer_end - Past the last pointer type found; 3185 iterator pointer_end() { return PointerTypes.end(); } 3186 3187 /// member_pointer_begin - First member pointer type found; 3188 iterator member_pointer_begin() { return MemberPointerTypes.begin(); } 3189 3190 /// member_pointer_end - Past the last member pointer type found; 3191 iterator member_pointer_end() { return MemberPointerTypes.end(); } 3192 3193 /// enumeration_begin - First enumeration type found; 3194 iterator enumeration_begin() { return EnumerationTypes.begin(); } 3195 3196 /// enumeration_end - Past the last enumeration type found; 3197 iterator enumeration_end() { return EnumerationTypes.end(); } 3198}; 3199 3200/// AddPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty to 3201/// the set of pointer types along with any more-qualified variants of 3202/// that type. For example, if @p Ty is "int const *", this routine 3203/// will add "int const *", "int const volatile *", "int const 3204/// restrict *", and "int const volatile restrict *" to the set of 3205/// pointer types. Returns true if the add of @p Ty itself succeeded, 3206/// false otherwise. 3207/// 3208/// FIXME: what to do about extended qualifiers? 3209bool 3210BuiltinCandidateTypeSet::AddPointerWithMoreQualifiedTypeVariants(QualType Ty, 3211 const Qualifiers &VisibleQuals) { 3212 3213 // Insert this type. 3214 if (!PointerTypes.insert(Ty)) 3215 return false; 3216 3217 const PointerType *PointerTy = Ty->getAs<PointerType>(); 3218 assert(PointerTy && "type was not a pointer type!"); 3219 3220 QualType PointeeTy = PointerTy->getPointeeType(); 3221 // Don't add qualified variants of arrays. For one, they're not allowed 3222 // (the qualifier would sink to the element type), and for another, the 3223 // only overload situation where it matters is subscript or pointer +- int, 3224 // and those shouldn't have qualifier variants anyway. 3225 if (PointeeTy->isArrayType()) 3226 return true; 3227 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 3228 if (const ConstantArrayType *Array =Context.getAsConstantArrayType(PointeeTy)) 3229 BaseCVR = Array->getElementType().getCVRQualifiers(); 3230 bool hasVolatile = VisibleQuals.hasVolatile(); 3231 bool hasRestrict = VisibleQuals.hasRestrict(); 3232 3233 // Iterate through all strict supersets of BaseCVR. 3234 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 3235 if ((CVR | BaseCVR) != CVR) continue; 3236 // Skip over Volatile/Restrict if no Volatile/Restrict found anywhere 3237 // in the types. 3238 if ((CVR & Qualifiers::Volatile) && !hasVolatile) continue; 3239 if ((CVR & Qualifiers::Restrict) && !hasRestrict) continue; 3240 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 3241 PointerTypes.insert(Context.getPointerType(QPointeeTy)); 3242 } 3243 3244 return true; 3245} 3246 3247/// AddMemberPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty 3248/// to the set of pointer types along with any more-qualified variants of 3249/// that type. For example, if @p Ty is "int const *", this routine 3250/// will add "int const *", "int const volatile *", "int const 3251/// restrict *", and "int const volatile restrict *" to the set of 3252/// pointer types. Returns true if the add of @p Ty itself succeeded, 3253/// false otherwise. 3254/// 3255/// FIXME: what to do about extended qualifiers? 3256bool 3257BuiltinCandidateTypeSet::AddMemberPointerWithMoreQualifiedTypeVariants( 3258 QualType Ty) { 3259 // Insert this type. 3260 if (!MemberPointerTypes.insert(Ty)) 3261 return false; 3262 3263 const MemberPointerType *PointerTy = Ty->getAs<MemberPointerType>(); 3264 assert(PointerTy && "type was not a member pointer type!"); 3265 3266 QualType PointeeTy = PointerTy->getPointeeType(); 3267 // Don't add qualified variants of arrays. For one, they're not allowed 3268 // (the qualifier would sink to the element type), and for another, the 3269 // only overload situation where it matters is subscript or pointer +- int, 3270 // and those shouldn't have qualifier variants anyway. 3271 if (PointeeTy->isArrayType()) 3272 return true; 3273 const Type *ClassTy = PointerTy->getClass(); 3274 3275 // Iterate through all strict supersets of the pointee type's CVR 3276 // qualifiers. 3277 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 3278 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 3279 if ((CVR | BaseCVR) != CVR) continue; 3280 3281 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 3282 MemberPointerTypes.insert(Context.getMemberPointerType(QPointeeTy, ClassTy)); 3283 } 3284 3285 return true; 3286} 3287 3288/// AddTypesConvertedFrom - Add each of the types to which the type @p 3289/// Ty can be implicit converted to the given set of @p Types. We're 3290/// primarily interested in pointer types and enumeration types. We also 3291/// take member pointer types, for the conditional operator. 3292/// AllowUserConversions is true if we should look at the conversion 3293/// functions of a class type, and AllowExplicitConversions if we 3294/// should also include the explicit conversion functions of a class 3295/// type. 3296void 3297BuiltinCandidateTypeSet::AddTypesConvertedFrom(QualType Ty, 3298 SourceLocation Loc, 3299 bool AllowUserConversions, 3300 bool AllowExplicitConversions, 3301 const Qualifiers &VisibleQuals) { 3302 // Only deal with canonical types. 3303 Ty = Context.getCanonicalType(Ty); 3304 3305 // Look through reference types; they aren't part of the type of an 3306 // expression for the purposes of conversions. 3307 if (const ReferenceType *RefTy = Ty->getAs<ReferenceType>()) 3308 Ty = RefTy->getPointeeType(); 3309 3310 // We don't care about qualifiers on the type. 3311 Ty = Ty.getLocalUnqualifiedType(); 3312 3313 // If we're dealing with an array type, decay to the pointer. 3314 if (Ty->isArrayType()) 3315 Ty = SemaRef.Context.getArrayDecayedType(Ty); 3316 3317 if (const PointerType *PointerTy = Ty->getAs<PointerType>()) { 3318 QualType PointeeTy = PointerTy->getPointeeType(); 3319 3320 // Insert our type, and its more-qualified variants, into the set 3321 // of types. 3322 if (!AddPointerWithMoreQualifiedTypeVariants(Ty, VisibleQuals)) 3323 return; 3324 } else if (Ty->isMemberPointerType()) { 3325 // Member pointers are far easier, since the pointee can't be converted. 3326 if (!AddMemberPointerWithMoreQualifiedTypeVariants(Ty)) 3327 return; 3328 } else if (Ty->isEnumeralType()) { 3329 EnumerationTypes.insert(Ty); 3330 } else if (AllowUserConversions) { 3331 if (const RecordType *TyRec = Ty->getAs<RecordType>()) { 3332 if (SemaRef.RequireCompleteType(Loc, Ty, 0)) { 3333 // No conversion functions in incomplete types. 3334 return; 3335 } 3336 3337 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 3338 const UnresolvedSetImpl *Conversions 3339 = ClassDecl->getVisibleConversionFunctions(); 3340 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 3341 E = Conversions->end(); I != E; ++I) { 3342 3343 // Skip conversion function templates; they don't tell us anything 3344 // about which builtin types we can convert to. 3345 if (isa<FunctionTemplateDecl>(*I)) 3346 continue; 3347 3348 CXXConversionDecl *Conv = cast<CXXConversionDecl>(*I); 3349 if (AllowExplicitConversions || !Conv->isExplicit()) { 3350 AddTypesConvertedFrom(Conv->getConversionType(), Loc, false, false, 3351 VisibleQuals); 3352 } 3353 } 3354 } 3355 } 3356} 3357 3358/// \brief Helper function for AddBuiltinOperatorCandidates() that adds 3359/// the volatile- and non-volatile-qualified assignment operators for the 3360/// given type to the candidate set. 3361static void AddBuiltinAssignmentOperatorCandidates(Sema &S, 3362 QualType T, 3363 Expr **Args, 3364 unsigned NumArgs, 3365 OverloadCandidateSet &CandidateSet) { 3366 QualType ParamTypes[2]; 3367 3368 // T& operator=(T&, T) 3369 ParamTypes[0] = S.Context.getLValueReferenceType(T); 3370 ParamTypes[1] = T; 3371 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3372 /*IsAssignmentOperator=*/true); 3373 3374 if (!S.Context.getCanonicalType(T).isVolatileQualified()) { 3375 // volatile T& operator=(volatile T&, T) 3376 ParamTypes[0] 3377 = S.Context.getLValueReferenceType(S.Context.getVolatileType(T)); 3378 ParamTypes[1] = T; 3379 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3380 /*IsAssignmentOperator=*/true); 3381 } 3382} 3383 3384/// CollectVRQualifiers - This routine returns Volatile/Restrict qualifiers, 3385/// if any, found in visible type conversion functions found in ArgExpr's type. 3386static Qualifiers CollectVRQualifiers(ASTContext &Context, Expr* ArgExpr) { 3387 Qualifiers VRQuals; 3388 const RecordType *TyRec; 3389 if (const MemberPointerType *RHSMPType = 3390 ArgExpr->getType()->getAs<MemberPointerType>()) 3391 TyRec = cast<RecordType>(RHSMPType->getClass()); 3392 else 3393 TyRec = ArgExpr->getType()->getAs<RecordType>(); 3394 if (!TyRec) { 3395 // Just to be safe, assume the worst case. 3396 VRQuals.addVolatile(); 3397 VRQuals.addRestrict(); 3398 return VRQuals; 3399 } 3400 3401 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 3402 if (!ClassDecl->hasDefinition()) 3403 return VRQuals; 3404 3405 const UnresolvedSetImpl *Conversions = 3406 ClassDecl->getVisibleConversionFunctions(); 3407 3408 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 3409 E = Conversions->end(); I != E; ++I) { 3410 if (CXXConversionDecl *Conv = dyn_cast<CXXConversionDecl>(*I)) { 3411 QualType CanTy = Context.getCanonicalType(Conv->getConversionType()); 3412 if (const ReferenceType *ResTypeRef = CanTy->getAs<ReferenceType>()) 3413 CanTy = ResTypeRef->getPointeeType(); 3414 // Need to go down the pointer/mempointer chain and add qualifiers 3415 // as see them. 3416 bool done = false; 3417 while (!done) { 3418 if (const PointerType *ResTypePtr = CanTy->getAs<PointerType>()) 3419 CanTy = ResTypePtr->getPointeeType(); 3420 else if (const MemberPointerType *ResTypeMPtr = 3421 CanTy->getAs<MemberPointerType>()) 3422 CanTy = ResTypeMPtr->getPointeeType(); 3423 else 3424 done = true; 3425 if (CanTy.isVolatileQualified()) 3426 VRQuals.addVolatile(); 3427 if (CanTy.isRestrictQualified()) 3428 VRQuals.addRestrict(); 3429 if (VRQuals.hasRestrict() && VRQuals.hasVolatile()) 3430 return VRQuals; 3431 } 3432 } 3433 } 3434 return VRQuals; 3435} 3436 3437/// AddBuiltinOperatorCandidates - Add the appropriate built-in 3438/// operator overloads to the candidate set (C++ [over.built]), based 3439/// on the operator @p Op and the arguments given. For example, if the 3440/// operator is a binary '+', this routine might add "int 3441/// operator+(int, int)" to cover integer addition. 3442void 3443Sema::AddBuiltinOperatorCandidates(OverloadedOperatorKind Op, 3444 SourceLocation OpLoc, 3445 Expr **Args, unsigned NumArgs, 3446 OverloadCandidateSet& CandidateSet) { 3447 // The set of "promoted arithmetic types", which are the arithmetic 3448 // types are that preserved by promotion (C++ [over.built]p2). Note 3449 // that the first few of these types are the promoted integral 3450 // types; these types need to be first. 3451 // FIXME: What about complex? 3452 const unsigned FirstIntegralType = 0; 3453 const unsigned LastIntegralType = 13; 3454 const unsigned FirstPromotedIntegralType = 7, 3455 LastPromotedIntegralType = 13; 3456 const unsigned FirstPromotedArithmeticType = 7, 3457 LastPromotedArithmeticType = 16; 3458 const unsigned NumArithmeticTypes = 16; 3459 QualType ArithmeticTypes[NumArithmeticTypes] = { 3460 Context.BoolTy, Context.CharTy, Context.WCharTy, 3461// FIXME: Context.Char16Ty, Context.Char32Ty, 3462 Context.SignedCharTy, Context.ShortTy, 3463 Context.UnsignedCharTy, Context.UnsignedShortTy, 3464 Context.IntTy, Context.LongTy, Context.LongLongTy, 3465 Context.UnsignedIntTy, Context.UnsignedLongTy, Context.UnsignedLongLongTy, 3466 Context.FloatTy, Context.DoubleTy, Context.LongDoubleTy 3467 }; 3468 assert(ArithmeticTypes[FirstPromotedIntegralType] == Context.IntTy && 3469 "Invalid first promoted integral type"); 3470 assert(ArithmeticTypes[LastPromotedIntegralType - 1] 3471 == Context.UnsignedLongLongTy && 3472 "Invalid last promoted integral type"); 3473 assert(ArithmeticTypes[FirstPromotedArithmeticType] == Context.IntTy && 3474 "Invalid first promoted arithmetic type"); 3475 assert(ArithmeticTypes[LastPromotedArithmeticType - 1] 3476 == Context.LongDoubleTy && 3477 "Invalid last promoted arithmetic type"); 3478 3479 // Find all of the types that the arguments can convert to, but only 3480 // if the operator we're looking at has built-in operator candidates 3481 // that make use of these types. 3482 Qualifiers VisibleTypeConversionsQuals; 3483 VisibleTypeConversionsQuals.addConst(); 3484 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 3485 VisibleTypeConversionsQuals += CollectVRQualifiers(Context, Args[ArgIdx]); 3486 3487 BuiltinCandidateTypeSet CandidateTypes(*this); 3488 if (Op == OO_Less || Op == OO_Greater || Op == OO_LessEqual || 3489 Op == OO_GreaterEqual || Op == OO_EqualEqual || Op == OO_ExclaimEqual || 3490 Op == OO_Plus || (Op == OO_Minus && NumArgs == 2) || Op == OO_Equal || 3491 Op == OO_PlusEqual || Op == OO_MinusEqual || Op == OO_Subscript || 3492 Op == OO_ArrowStar || Op == OO_PlusPlus || Op == OO_MinusMinus || 3493 (Op == OO_Star && NumArgs == 1) || Op == OO_Conditional) { 3494 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 3495 CandidateTypes.AddTypesConvertedFrom(Args[ArgIdx]->getType(), 3496 OpLoc, 3497 true, 3498 (Op == OO_Exclaim || 3499 Op == OO_AmpAmp || 3500 Op == OO_PipePipe), 3501 VisibleTypeConversionsQuals); 3502 } 3503 3504 bool isComparison = false; 3505 switch (Op) { 3506 case OO_None: 3507 case NUM_OVERLOADED_OPERATORS: 3508 assert(false && "Expected an overloaded operator"); 3509 break; 3510 3511 case OO_Star: // '*' is either unary or binary 3512 if (NumArgs == 1) 3513 goto UnaryStar; 3514 else 3515 goto BinaryStar; 3516 break; 3517 3518 case OO_Plus: // '+' is either unary or binary 3519 if (NumArgs == 1) 3520 goto UnaryPlus; 3521 else 3522 goto BinaryPlus; 3523 break; 3524 3525 case OO_Minus: // '-' is either unary or binary 3526 if (NumArgs == 1) 3527 goto UnaryMinus; 3528 else 3529 goto BinaryMinus; 3530 break; 3531 3532 case OO_Amp: // '&' is either unary or binary 3533 if (NumArgs == 1) 3534 goto UnaryAmp; 3535 else 3536 goto BinaryAmp; 3537 3538 case OO_PlusPlus: 3539 case OO_MinusMinus: 3540 // C++ [over.built]p3: 3541 // 3542 // For every pair (T, VQ), where T is an arithmetic type, and VQ 3543 // is either volatile or empty, there exist candidate operator 3544 // functions of the form 3545 // 3546 // VQ T& operator++(VQ T&); 3547 // T operator++(VQ T&, int); 3548 // 3549 // C++ [over.built]p4: 3550 // 3551 // For every pair (T, VQ), where T is an arithmetic type other 3552 // than bool, and VQ is either volatile or empty, there exist 3553 // candidate operator functions of the form 3554 // 3555 // VQ T& operator--(VQ T&); 3556 // T operator--(VQ T&, int); 3557 for (unsigned Arith = (Op == OO_PlusPlus? 0 : 1); 3558 Arith < NumArithmeticTypes; ++Arith) { 3559 QualType ArithTy = ArithmeticTypes[Arith]; 3560 QualType ParamTypes[2] 3561 = { Context.getLValueReferenceType(ArithTy), Context.IntTy }; 3562 3563 // Non-volatile version. 3564 if (NumArgs == 1) 3565 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3566 else 3567 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 3568 // heuristic to reduce number of builtin candidates in the set. 3569 // Add volatile version only if there are conversions to a volatile type. 3570 if (VisibleTypeConversionsQuals.hasVolatile()) { 3571 // Volatile version 3572 ParamTypes[0] 3573 = Context.getLValueReferenceType(Context.getVolatileType(ArithTy)); 3574 if (NumArgs == 1) 3575 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3576 else 3577 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 3578 } 3579 } 3580 3581 // C++ [over.built]p5: 3582 // 3583 // For every pair (T, VQ), where T is a cv-qualified or 3584 // cv-unqualified object type, and VQ is either volatile or 3585 // empty, there exist candidate operator functions of the form 3586 // 3587 // T*VQ& operator++(T*VQ&); 3588 // T*VQ& operator--(T*VQ&); 3589 // T* operator++(T*VQ&, int); 3590 // T* operator--(T*VQ&, int); 3591 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3592 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3593 // Skip pointer types that aren't pointers to object types. 3594 if (!(*Ptr)->getAs<PointerType>()->getPointeeType()->isObjectType()) 3595 continue; 3596 3597 QualType ParamTypes[2] = { 3598 Context.getLValueReferenceType(*Ptr), Context.IntTy 3599 }; 3600 3601 // Without volatile 3602 if (NumArgs == 1) 3603 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3604 else 3605 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3606 3607 if (!Context.getCanonicalType(*Ptr).isVolatileQualified() && 3608 VisibleTypeConversionsQuals.hasVolatile()) { 3609 // With volatile 3610 ParamTypes[0] 3611 = Context.getLValueReferenceType(Context.getVolatileType(*Ptr)); 3612 if (NumArgs == 1) 3613 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3614 else 3615 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3616 } 3617 } 3618 break; 3619 3620 UnaryStar: 3621 // C++ [over.built]p6: 3622 // For every cv-qualified or cv-unqualified object type T, there 3623 // exist candidate operator functions of the form 3624 // 3625 // T& operator*(T*); 3626 // 3627 // C++ [over.built]p7: 3628 // For every function type T, there exist candidate operator 3629 // functions of the form 3630 // T& operator*(T*); 3631 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3632 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3633 QualType ParamTy = *Ptr; 3634 QualType PointeeTy = ParamTy->getAs<PointerType>()->getPointeeType(); 3635 AddBuiltinCandidate(Context.getLValueReferenceType(PointeeTy), 3636 &ParamTy, Args, 1, CandidateSet); 3637 } 3638 break; 3639 3640 UnaryPlus: 3641 // C++ [over.built]p8: 3642 // For every type T, there exist candidate operator functions of 3643 // the form 3644 // 3645 // T* operator+(T*); 3646 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3647 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3648 QualType ParamTy = *Ptr; 3649 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet); 3650 } 3651 3652 // Fall through 3653 3654 UnaryMinus: 3655 // C++ [over.built]p9: 3656 // For every promoted arithmetic type T, there exist candidate 3657 // operator functions of the form 3658 // 3659 // T operator+(T); 3660 // T operator-(T); 3661 for (unsigned Arith = FirstPromotedArithmeticType; 3662 Arith < LastPromotedArithmeticType; ++Arith) { 3663 QualType ArithTy = ArithmeticTypes[Arith]; 3664 AddBuiltinCandidate(ArithTy, &ArithTy, Args, 1, CandidateSet); 3665 } 3666 break; 3667 3668 case OO_Tilde: 3669 // C++ [over.built]p10: 3670 // For every promoted integral type T, there exist candidate 3671 // operator functions of the form 3672 // 3673 // T operator~(T); 3674 for (unsigned Int = FirstPromotedIntegralType; 3675 Int < LastPromotedIntegralType; ++Int) { 3676 QualType IntTy = ArithmeticTypes[Int]; 3677 AddBuiltinCandidate(IntTy, &IntTy, Args, 1, CandidateSet); 3678 } 3679 break; 3680 3681 case OO_New: 3682 case OO_Delete: 3683 case OO_Array_New: 3684 case OO_Array_Delete: 3685 case OO_Call: 3686 assert(false && "Special operators don't use AddBuiltinOperatorCandidates"); 3687 break; 3688 3689 case OO_Comma: 3690 UnaryAmp: 3691 case OO_Arrow: 3692 // C++ [over.match.oper]p3: 3693 // -- For the operator ',', the unary operator '&', or the 3694 // operator '->', the built-in candidates set is empty. 3695 break; 3696 3697 case OO_EqualEqual: 3698 case OO_ExclaimEqual: 3699 // C++ [over.match.oper]p16: 3700 // For every pointer to member type T, there exist candidate operator 3701 // functions of the form 3702 // 3703 // bool operator==(T,T); 3704 // bool operator!=(T,T); 3705 for (BuiltinCandidateTypeSet::iterator 3706 MemPtr = CandidateTypes.member_pointer_begin(), 3707 MemPtrEnd = CandidateTypes.member_pointer_end(); 3708 MemPtr != MemPtrEnd; 3709 ++MemPtr) { 3710 QualType ParamTypes[2] = { *MemPtr, *MemPtr }; 3711 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 3712 } 3713 3714 // Fall through 3715 3716 case OO_Less: 3717 case OO_Greater: 3718 case OO_LessEqual: 3719 case OO_GreaterEqual: 3720 // C++ [over.built]p15: 3721 // 3722 // For every pointer or enumeration type T, there exist 3723 // candidate operator functions of the form 3724 // 3725 // bool operator<(T, T); 3726 // bool operator>(T, T); 3727 // bool operator<=(T, T); 3728 // bool operator>=(T, T); 3729 // bool operator==(T, T); 3730 // bool operator!=(T, T); 3731 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3732 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3733 QualType ParamTypes[2] = { *Ptr, *Ptr }; 3734 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 3735 } 3736 for (BuiltinCandidateTypeSet::iterator Enum 3737 = CandidateTypes.enumeration_begin(); 3738 Enum != CandidateTypes.enumeration_end(); ++Enum) { 3739 QualType ParamTypes[2] = { *Enum, *Enum }; 3740 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 3741 } 3742 3743 // Fall through. 3744 isComparison = true; 3745 3746 BinaryPlus: 3747 BinaryMinus: 3748 if (!isComparison) { 3749 // We didn't fall through, so we must have OO_Plus or OO_Minus. 3750 3751 // C++ [over.built]p13: 3752 // 3753 // For every cv-qualified or cv-unqualified object type T 3754 // there exist candidate operator functions of the form 3755 // 3756 // T* operator+(T*, ptrdiff_t); 3757 // T& operator[](T*, ptrdiff_t); [BELOW] 3758 // T* operator-(T*, ptrdiff_t); 3759 // T* operator+(ptrdiff_t, T*); 3760 // T& operator[](ptrdiff_t, T*); [BELOW] 3761 // 3762 // C++ [over.built]p14: 3763 // 3764 // For every T, where T is a pointer to object type, there 3765 // exist candidate operator functions of the form 3766 // 3767 // ptrdiff_t operator-(T, T); 3768 for (BuiltinCandidateTypeSet::iterator Ptr 3769 = CandidateTypes.pointer_begin(); 3770 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3771 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 3772 3773 // operator+(T*, ptrdiff_t) or operator-(T*, ptrdiff_t) 3774 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3775 3776 if (Op == OO_Plus) { 3777 // T* operator+(ptrdiff_t, T*); 3778 ParamTypes[0] = ParamTypes[1]; 3779 ParamTypes[1] = *Ptr; 3780 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3781 } else { 3782 // ptrdiff_t operator-(T, T); 3783 ParamTypes[1] = *Ptr; 3784 AddBuiltinCandidate(Context.getPointerDiffType(), ParamTypes, 3785 Args, 2, CandidateSet); 3786 } 3787 } 3788 } 3789 // Fall through 3790 3791 case OO_Slash: 3792 BinaryStar: 3793 Conditional: 3794 // C++ [over.built]p12: 3795 // 3796 // For every pair of promoted arithmetic types L and R, there 3797 // exist candidate operator functions of the form 3798 // 3799 // LR operator*(L, R); 3800 // LR operator/(L, R); 3801 // LR operator+(L, R); 3802 // LR operator-(L, R); 3803 // bool operator<(L, R); 3804 // bool operator>(L, R); 3805 // bool operator<=(L, R); 3806 // bool operator>=(L, R); 3807 // bool operator==(L, R); 3808 // bool operator!=(L, R); 3809 // 3810 // where LR is the result of the usual arithmetic conversions 3811 // between types L and R. 3812 // 3813 // C++ [over.built]p24: 3814 // 3815 // For every pair of promoted arithmetic types L and R, there exist 3816 // candidate operator functions of the form 3817 // 3818 // LR operator?(bool, L, R); 3819 // 3820 // where LR is the result of the usual arithmetic conversions 3821 // between types L and R. 3822 // Our candidates ignore the first parameter. 3823 for (unsigned Left = FirstPromotedArithmeticType; 3824 Left < LastPromotedArithmeticType; ++Left) { 3825 for (unsigned Right = FirstPromotedArithmeticType; 3826 Right < LastPromotedArithmeticType; ++Right) { 3827 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 3828 QualType Result 3829 = isComparison 3830 ? Context.BoolTy 3831 : Context.UsualArithmeticConversionsType(LandR[0], LandR[1]); 3832 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 3833 } 3834 } 3835 break; 3836 3837 case OO_Percent: 3838 BinaryAmp: 3839 case OO_Caret: 3840 case OO_Pipe: 3841 case OO_LessLess: 3842 case OO_GreaterGreater: 3843 // C++ [over.built]p17: 3844 // 3845 // For every pair of promoted integral types L and R, there 3846 // exist candidate operator functions of the form 3847 // 3848 // LR operator%(L, R); 3849 // LR operator&(L, R); 3850 // LR operator^(L, R); 3851 // LR operator|(L, R); 3852 // L operator<<(L, R); 3853 // L operator>>(L, R); 3854 // 3855 // where LR is the result of the usual arithmetic conversions 3856 // between types L and R. 3857 for (unsigned Left = FirstPromotedIntegralType; 3858 Left < LastPromotedIntegralType; ++Left) { 3859 for (unsigned Right = FirstPromotedIntegralType; 3860 Right < LastPromotedIntegralType; ++Right) { 3861 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 3862 QualType Result = (Op == OO_LessLess || Op == OO_GreaterGreater) 3863 ? LandR[0] 3864 : Context.UsualArithmeticConversionsType(LandR[0], LandR[1]); 3865 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 3866 } 3867 } 3868 break; 3869 3870 case OO_Equal: 3871 // C++ [over.built]p20: 3872 // 3873 // For every pair (T, VQ), where T is an enumeration or 3874 // pointer to member type and VQ is either volatile or 3875 // empty, there exist candidate operator functions of the form 3876 // 3877 // VQ T& operator=(VQ T&, T); 3878 for (BuiltinCandidateTypeSet::iterator 3879 Enum = CandidateTypes.enumeration_begin(), 3880 EnumEnd = CandidateTypes.enumeration_end(); 3881 Enum != EnumEnd; ++Enum) 3882 AddBuiltinAssignmentOperatorCandidates(*this, *Enum, Args, 2, 3883 CandidateSet); 3884 for (BuiltinCandidateTypeSet::iterator 3885 MemPtr = CandidateTypes.member_pointer_begin(), 3886 MemPtrEnd = CandidateTypes.member_pointer_end(); 3887 MemPtr != MemPtrEnd; ++MemPtr) 3888 AddBuiltinAssignmentOperatorCandidates(*this, *MemPtr, Args, 2, 3889 CandidateSet); 3890 // Fall through. 3891 3892 case OO_PlusEqual: 3893 case OO_MinusEqual: 3894 // C++ [over.built]p19: 3895 // 3896 // For every pair (T, VQ), where T is any type and VQ is either 3897 // volatile or empty, there exist candidate operator functions 3898 // of the form 3899 // 3900 // T*VQ& operator=(T*VQ&, T*); 3901 // 3902 // C++ [over.built]p21: 3903 // 3904 // For every pair (T, VQ), where T is a cv-qualified or 3905 // cv-unqualified object type and VQ is either volatile or 3906 // empty, there exist candidate operator functions of the form 3907 // 3908 // T*VQ& operator+=(T*VQ&, ptrdiff_t); 3909 // T*VQ& operator-=(T*VQ&, ptrdiff_t); 3910 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3911 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3912 QualType ParamTypes[2]; 3913 ParamTypes[1] = (Op == OO_Equal)? *Ptr : Context.getPointerDiffType(); 3914 3915 // non-volatile version 3916 ParamTypes[0] = Context.getLValueReferenceType(*Ptr); 3917 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3918 /*IsAssigmentOperator=*/Op == OO_Equal); 3919 3920 if (!Context.getCanonicalType(*Ptr).isVolatileQualified() && 3921 VisibleTypeConversionsQuals.hasVolatile()) { 3922 // volatile version 3923 ParamTypes[0] 3924 = Context.getLValueReferenceType(Context.getVolatileType(*Ptr)); 3925 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3926 /*IsAssigmentOperator=*/Op == OO_Equal); 3927 } 3928 } 3929 // Fall through. 3930 3931 case OO_StarEqual: 3932 case OO_SlashEqual: 3933 // C++ [over.built]p18: 3934 // 3935 // For every triple (L, VQ, R), where L is an arithmetic type, 3936 // VQ is either volatile or empty, and R is a promoted 3937 // arithmetic type, there exist candidate operator functions of 3938 // the form 3939 // 3940 // VQ L& operator=(VQ L&, R); 3941 // VQ L& operator*=(VQ L&, R); 3942 // VQ L& operator/=(VQ L&, R); 3943 // VQ L& operator+=(VQ L&, R); 3944 // VQ L& operator-=(VQ L&, R); 3945 for (unsigned Left = 0; Left < NumArithmeticTypes; ++Left) { 3946 for (unsigned Right = FirstPromotedArithmeticType; 3947 Right < LastPromotedArithmeticType; ++Right) { 3948 QualType ParamTypes[2]; 3949 ParamTypes[1] = ArithmeticTypes[Right]; 3950 3951 // Add this built-in operator as a candidate (VQ is empty). 3952 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 3953 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3954 /*IsAssigmentOperator=*/Op == OO_Equal); 3955 3956 // Add this built-in operator as a candidate (VQ is 'volatile'). 3957 if (VisibleTypeConversionsQuals.hasVolatile()) { 3958 ParamTypes[0] = Context.getVolatileType(ArithmeticTypes[Left]); 3959 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 3960 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3961 /*IsAssigmentOperator=*/Op == OO_Equal); 3962 } 3963 } 3964 } 3965 break; 3966 3967 case OO_PercentEqual: 3968 case OO_LessLessEqual: 3969 case OO_GreaterGreaterEqual: 3970 case OO_AmpEqual: 3971 case OO_CaretEqual: 3972 case OO_PipeEqual: 3973 // C++ [over.built]p22: 3974 // 3975 // For every triple (L, VQ, R), where L is an integral type, VQ 3976 // is either volatile or empty, and R is a promoted integral 3977 // type, there exist candidate operator functions of the form 3978 // 3979 // VQ L& operator%=(VQ L&, R); 3980 // VQ L& operator<<=(VQ L&, R); 3981 // VQ L& operator>>=(VQ L&, R); 3982 // VQ L& operator&=(VQ L&, R); 3983 // VQ L& operator^=(VQ L&, R); 3984 // VQ L& operator|=(VQ L&, R); 3985 for (unsigned Left = FirstIntegralType; Left < LastIntegralType; ++Left) { 3986 for (unsigned Right = FirstPromotedIntegralType; 3987 Right < LastPromotedIntegralType; ++Right) { 3988 QualType ParamTypes[2]; 3989 ParamTypes[1] = ArithmeticTypes[Right]; 3990 3991 // Add this built-in operator as a candidate (VQ is empty). 3992 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 3993 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 3994 if (VisibleTypeConversionsQuals.hasVolatile()) { 3995 // Add this built-in operator as a candidate (VQ is 'volatile'). 3996 ParamTypes[0] = ArithmeticTypes[Left]; 3997 ParamTypes[0] = Context.getVolatileType(ParamTypes[0]); 3998 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 3999 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 4000 } 4001 } 4002 } 4003 break; 4004 4005 case OO_Exclaim: { 4006 // C++ [over.operator]p23: 4007 // 4008 // There also exist candidate operator functions of the form 4009 // 4010 // bool operator!(bool); 4011 // bool operator&&(bool, bool); [BELOW] 4012 // bool operator||(bool, bool); [BELOW] 4013 QualType ParamTy = Context.BoolTy; 4014 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet, 4015 /*IsAssignmentOperator=*/false, 4016 /*NumContextualBoolArguments=*/1); 4017 break; 4018 } 4019 4020 case OO_AmpAmp: 4021 case OO_PipePipe: { 4022 // C++ [over.operator]p23: 4023 // 4024 // There also exist candidate operator functions of the form 4025 // 4026 // bool operator!(bool); [ABOVE] 4027 // bool operator&&(bool, bool); 4028 // bool operator||(bool, bool); 4029 QualType ParamTypes[2] = { Context.BoolTy, Context.BoolTy }; 4030 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet, 4031 /*IsAssignmentOperator=*/false, 4032 /*NumContextualBoolArguments=*/2); 4033 break; 4034 } 4035 4036 case OO_Subscript: 4037 // C++ [over.built]p13: 4038 // 4039 // For every cv-qualified or cv-unqualified object type T there 4040 // exist candidate operator functions of the form 4041 // 4042 // T* operator+(T*, ptrdiff_t); [ABOVE] 4043 // T& operator[](T*, ptrdiff_t); 4044 // T* operator-(T*, ptrdiff_t); [ABOVE] 4045 // T* operator+(ptrdiff_t, T*); [ABOVE] 4046 // T& operator[](ptrdiff_t, T*); 4047 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 4048 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4049 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 4050 QualType PointeeType = (*Ptr)->getAs<PointerType>()->getPointeeType(); 4051 QualType ResultTy = Context.getLValueReferenceType(PointeeType); 4052 4053 // T& operator[](T*, ptrdiff_t) 4054 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 4055 4056 // T& operator[](ptrdiff_t, T*); 4057 ParamTypes[0] = ParamTypes[1]; 4058 ParamTypes[1] = *Ptr; 4059 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 4060 } 4061 break; 4062 4063 case OO_ArrowStar: 4064 // C++ [over.built]p11: 4065 // For every quintuple (C1, C2, T, CV1, CV2), where C2 is a class type, 4066 // C1 is the same type as C2 or is a derived class of C2, T is an object 4067 // type or a function type, and CV1 and CV2 are cv-qualifier-seqs, 4068 // there exist candidate operator functions of the form 4069 // CV12 T& operator->*(CV1 C1*, CV2 T C2::*); 4070 // where CV12 is the union of CV1 and CV2. 4071 { 4072 for (BuiltinCandidateTypeSet::iterator Ptr = 4073 CandidateTypes.pointer_begin(); 4074 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4075 QualType C1Ty = (*Ptr); 4076 QualType C1; 4077 QualifierCollector Q1; 4078 if (const PointerType *PointerTy = C1Ty->getAs<PointerType>()) { 4079 C1 = QualType(Q1.strip(PointerTy->getPointeeType()), 0); 4080 if (!isa<RecordType>(C1)) 4081 continue; 4082 // heuristic to reduce number of builtin candidates in the set. 4083 // Add volatile/restrict version only if there are conversions to a 4084 // volatile/restrict type. 4085 if (!VisibleTypeConversionsQuals.hasVolatile() && Q1.hasVolatile()) 4086 continue; 4087 if (!VisibleTypeConversionsQuals.hasRestrict() && Q1.hasRestrict()) 4088 continue; 4089 } 4090 for (BuiltinCandidateTypeSet::iterator 4091 MemPtr = CandidateTypes.member_pointer_begin(), 4092 MemPtrEnd = CandidateTypes.member_pointer_end(); 4093 MemPtr != MemPtrEnd; ++MemPtr) { 4094 const MemberPointerType *mptr = cast<MemberPointerType>(*MemPtr); 4095 QualType C2 = QualType(mptr->getClass(), 0); 4096 C2 = C2.getUnqualifiedType(); 4097 if (C1 != C2 && !IsDerivedFrom(C1, C2)) 4098 break; 4099 QualType ParamTypes[2] = { *Ptr, *MemPtr }; 4100 // build CV12 T& 4101 QualType T = mptr->getPointeeType(); 4102 if (!VisibleTypeConversionsQuals.hasVolatile() && 4103 T.isVolatileQualified()) 4104 continue; 4105 if (!VisibleTypeConversionsQuals.hasRestrict() && 4106 T.isRestrictQualified()) 4107 continue; 4108 T = Q1.apply(T); 4109 QualType ResultTy = Context.getLValueReferenceType(T); 4110 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 4111 } 4112 } 4113 } 4114 break; 4115 4116 case OO_Conditional: 4117 // Note that we don't consider the first argument, since it has been 4118 // contextually converted to bool long ago. The candidates below are 4119 // therefore added as binary. 4120 // 4121 // C++ [over.built]p24: 4122 // For every type T, where T is a pointer or pointer-to-member type, 4123 // there exist candidate operator functions of the form 4124 // 4125 // T operator?(bool, T, T); 4126 // 4127 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(), 4128 E = CandidateTypes.pointer_end(); Ptr != E; ++Ptr) { 4129 QualType ParamTypes[2] = { *Ptr, *Ptr }; 4130 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 4131 } 4132 for (BuiltinCandidateTypeSet::iterator Ptr = 4133 CandidateTypes.member_pointer_begin(), 4134 E = CandidateTypes.member_pointer_end(); Ptr != E; ++Ptr) { 4135 QualType ParamTypes[2] = { *Ptr, *Ptr }; 4136 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 4137 } 4138 goto Conditional; 4139 } 4140} 4141 4142/// \brief Add function candidates found via argument-dependent lookup 4143/// to the set of overloading candidates. 4144/// 4145/// This routine performs argument-dependent name lookup based on the 4146/// given function name (which may also be an operator name) and adds 4147/// all of the overload candidates found by ADL to the overload 4148/// candidate set (C++ [basic.lookup.argdep]). 4149void 4150Sema::AddArgumentDependentLookupCandidates(DeclarationName Name, 4151 bool Operator, 4152 Expr **Args, unsigned NumArgs, 4153 const TemplateArgumentListInfo *ExplicitTemplateArgs, 4154 OverloadCandidateSet& CandidateSet, 4155 bool PartialOverloading) { 4156 ADLResult Fns; 4157 4158 // FIXME: This approach for uniquing ADL results (and removing 4159 // redundant candidates from the set) relies on pointer-equality, 4160 // which means we need to key off the canonical decl. However, 4161 // always going back to the canonical decl might not get us the 4162 // right set of default arguments. What default arguments are 4163 // we supposed to consider on ADL candidates, anyway? 4164 4165 // FIXME: Pass in the explicit template arguments? 4166 ArgumentDependentLookup(Name, Operator, Args, NumArgs, Fns); 4167 4168 // Erase all of the candidates we already knew about. 4169 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 4170 CandEnd = CandidateSet.end(); 4171 Cand != CandEnd; ++Cand) 4172 if (Cand->Function) { 4173 Fns.erase(Cand->Function); 4174 if (FunctionTemplateDecl *FunTmpl = Cand->Function->getPrimaryTemplate()) 4175 Fns.erase(FunTmpl); 4176 } 4177 4178 // For each of the ADL candidates we found, add it to the overload 4179 // set. 4180 for (ADLResult::iterator I = Fns.begin(), E = Fns.end(); I != E; ++I) { 4181 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*I)) { 4182 if (ExplicitTemplateArgs) 4183 continue; 4184 4185 AddOverloadCandidate(FD, AS_none, Args, NumArgs, CandidateSet, 4186 false, false, PartialOverloading); 4187 } else 4188 AddTemplateOverloadCandidate(cast<FunctionTemplateDecl>(*I), 4189 AS_none, ExplicitTemplateArgs, 4190 Args, NumArgs, CandidateSet); 4191 } 4192} 4193 4194/// isBetterOverloadCandidate - Determines whether the first overload 4195/// candidate is a better candidate than the second (C++ 13.3.3p1). 4196bool 4197Sema::isBetterOverloadCandidate(const OverloadCandidate& Cand1, 4198 const OverloadCandidate& Cand2, 4199 SourceLocation Loc) { 4200 // Define viable functions to be better candidates than non-viable 4201 // functions. 4202 if (!Cand2.Viable) 4203 return Cand1.Viable; 4204 else if (!Cand1.Viable) 4205 return false; 4206 4207 // C++ [over.match.best]p1: 4208 // 4209 // -- if F is a static member function, ICS1(F) is defined such 4210 // that ICS1(F) is neither better nor worse than ICS1(G) for 4211 // any function G, and, symmetrically, ICS1(G) is neither 4212 // better nor worse than ICS1(F). 4213 unsigned StartArg = 0; 4214 if (Cand1.IgnoreObjectArgument || Cand2.IgnoreObjectArgument) 4215 StartArg = 1; 4216 4217 // C++ [over.match.best]p1: 4218 // A viable function F1 is defined to be a better function than another 4219 // viable function F2 if for all arguments i, ICSi(F1) is not a worse 4220 // conversion sequence than ICSi(F2), and then... 4221 unsigned NumArgs = Cand1.Conversions.size(); 4222 assert(Cand2.Conversions.size() == NumArgs && "Overload candidate mismatch"); 4223 bool HasBetterConversion = false; 4224 for (unsigned ArgIdx = StartArg; ArgIdx < NumArgs; ++ArgIdx) { 4225 switch (CompareImplicitConversionSequences(Cand1.Conversions[ArgIdx], 4226 Cand2.Conversions[ArgIdx])) { 4227 case ImplicitConversionSequence::Better: 4228 // Cand1 has a better conversion sequence. 4229 HasBetterConversion = true; 4230 break; 4231 4232 case ImplicitConversionSequence::Worse: 4233 // Cand1 can't be better than Cand2. 4234 return false; 4235 4236 case ImplicitConversionSequence::Indistinguishable: 4237 // Do nothing. 4238 break; 4239 } 4240 } 4241 4242 // -- for some argument j, ICSj(F1) is a better conversion sequence than 4243 // ICSj(F2), or, if not that, 4244 if (HasBetterConversion) 4245 return true; 4246 4247 // - F1 is a non-template function and F2 is a function template 4248 // specialization, or, if not that, 4249 if (Cand1.Function && !Cand1.Function->getPrimaryTemplate() && 4250 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 4251 return true; 4252 4253 // -- F1 and F2 are function template specializations, and the function 4254 // template for F1 is more specialized than the template for F2 4255 // according to the partial ordering rules described in 14.5.5.2, or, 4256 // if not that, 4257 if (Cand1.Function && Cand1.Function->getPrimaryTemplate() && 4258 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 4259 if (FunctionTemplateDecl *BetterTemplate 4260 = getMoreSpecializedTemplate(Cand1.Function->getPrimaryTemplate(), 4261 Cand2.Function->getPrimaryTemplate(), 4262 Loc, 4263 isa<CXXConversionDecl>(Cand1.Function)? TPOC_Conversion 4264 : TPOC_Call)) 4265 return BetterTemplate == Cand1.Function->getPrimaryTemplate(); 4266 4267 // -- the context is an initialization by user-defined conversion 4268 // (see 8.5, 13.3.1.5) and the standard conversion sequence 4269 // from the return type of F1 to the destination type (i.e., 4270 // the type of the entity being initialized) is a better 4271 // conversion sequence than the standard conversion sequence 4272 // from the return type of F2 to the destination type. 4273 if (Cand1.Function && Cand2.Function && 4274 isa<CXXConversionDecl>(Cand1.Function) && 4275 isa<CXXConversionDecl>(Cand2.Function)) { 4276 switch (CompareStandardConversionSequences(Cand1.FinalConversion, 4277 Cand2.FinalConversion)) { 4278 case ImplicitConversionSequence::Better: 4279 // Cand1 has a better conversion sequence. 4280 return true; 4281 4282 case ImplicitConversionSequence::Worse: 4283 // Cand1 can't be better than Cand2. 4284 return false; 4285 4286 case ImplicitConversionSequence::Indistinguishable: 4287 // Do nothing 4288 break; 4289 } 4290 } 4291 4292 return false; 4293} 4294 4295/// \brief Computes the best viable function (C++ 13.3.3) 4296/// within an overload candidate set. 4297/// 4298/// \param CandidateSet the set of candidate functions. 4299/// 4300/// \param Loc the location of the function name (or operator symbol) for 4301/// which overload resolution occurs. 4302/// 4303/// \param Best f overload resolution was successful or found a deleted 4304/// function, Best points to the candidate function found. 4305/// 4306/// \returns The result of overload resolution. 4307OverloadingResult Sema::BestViableFunction(OverloadCandidateSet& CandidateSet, 4308 SourceLocation Loc, 4309 OverloadCandidateSet::iterator& Best) { 4310 // Find the best viable function. 4311 Best = CandidateSet.end(); 4312 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 4313 Cand != CandidateSet.end(); ++Cand) { 4314 if (Cand->Viable) { 4315 if (Best == CandidateSet.end() || 4316 isBetterOverloadCandidate(*Cand, *Best, Loc)) 4317 Best = Cand; 4318 } 4319 } 4320 4321 // If we didn't find any viable functions, abort. 4322 if (Best == CandidateSet.end()) 4323 return OR_No_Viable_Function; 4324 4325 // Make sure that this function is better than every other viable 4326 // function. If not, we have an ambiguity. 4327 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 4328 Cand != CandidateSet.end(); ++Cand) { 4329 if (Cand->Viable && 4330 Cand != Best && 4331 !isBetterOverloadCandidate(*Best, *Cand, Loc)) { 4332 Best = CandidateSet.end(); 4333 return OR_Ambiguous; 4334 } 4335 } 4336 4337 // Best is the best viable function. 4338 if (Best->Function && 4339 (Best->Function->isDeleted() || 4340 Best->Function->getAttr<UnavailableAttr>())) 4341 return OR_Deleted; 4342 4343 // C++ [basic.def.odr]p2: 4344 // An overloaded function is used if it is selected by overload resolution 4345 // when referred to from a potentially-evaluated expression. [Note: this 4346 // covers calls to named functions (5.2.2), operator overloading 4347 // (clause 13), user-defined conversions (12.3.2), allocation function for 4348 // placement new (5.3.4), as well as non-default initialization (8.5). 4349 if (Best->Function) 4350 MarkDeclarationReferenced(Loc, Best->Function); 4351 return OR_Success; 4352} 4353 4354namespace { 4355 4356enum OverloadCandidateKind { 4357 oc_function, 4358 oc_method, 4359 oc_constructor, 4360 oc_function_template, 4361 oc_method_template, 4362 oc_constructor_template, 4363 oc_implicit_default_constructor, 4364 oc_implicit_copy_constructor, 4365 oc_implicit_copy_assignment 4366}; 4367 4368OverloadCandidateKind ClassifyOverloadCandidate(Sema &S, 4369 FunctionDecl *Fn, 4370 std::string &Description) { 4371 bool isTemplate = false; 4372 4373 if (FunctionTemplateDecl *FunTmpl = Fn->getPrimaryTemplate()) { 4374 isTemplate = true; 4375 Description = S.getTemplateArgumentBindingsText( 4376 FunTmpl->getTemplateParameters(), *Fn->getTemplateSpecializationArgs()); 4377 } 4378 4379 if (CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(Fn)) { 4380 if (!Ctor->isImplicit()) 4381 return isTemplate ? oc_constructor_template : oc_constructor; 4382 4383 return Ctor->isCopyConstructor() ? oc_implicit_copy_constructor 4384 : oc_implicit_default_constructor; 4385 } 4386 4387 if (CXXMethodDecl *Meth = dyn_cast<CXXMethodDecl>(Fn)) { 4388 // This actually gets spelled 'candidate function' for now, but 4389 // it doesn't hurt to split it out. 4390 if (!Meth->isImplicit()) 4391 return isTemplate ? oc_method_template : oc_method; 4392 4393 assert(Meth->isCopyAssignment() 4394 && "implicit method is not copy assignment operator?"); 4395 return oc_implicit_copy_assignment; 4396 } 4397 4398 return isTemplate ? oc_function_template : oc_function; 4399} 4400 4401} // end anonymous namespace 4402 4403// Notes the location of an overload candidate. 4404void Sema::NoteOverloadCandidate(FunctionDecl *Fn) { 4405 std::string FnDesc; 4406 OverloadCandidateKind K = ClassifyOverloadCandidate(*this, Fn, FnDesc); 4407 Diag(Fn->getLocation(), diag::note_ovl_candidate) 4408 << (unsigned) K << FnDesc; 4409} 4410 4411/// Diagnoses an ambiguous conversion. The partial diagnostic is the 4412/// "lead" diagnostic; it will be given two arguments, the source and 4413/// target types of the conversion. 4414void Sema::DiagnoseAmbiguousConversion(const ImplicitConversionSequence &ICS, 4415 SourceLocation CaretLoc, 4416 const PartialDiagnostic &PDiag) { 4417 Diag(CaretLoc, PDiag) 4418 << ICS.Ambiguous.getFromType() << ICS.Ambiguous.getToType(); 4419 for (AmbiguousConversionSequence::const_iterator 4420 I = ICS.Ambiguous.begin(), E = ICS.Ambiguous.end(); I != E; ++I) { 4421 NoteOverloadCandidate(*I); 4422 } 4423} 4424 4425namespace { 4426 4427void DiagnoseBadConversion(Sema &S, OverloadCandidate *Cand, unsigned I) { 4428 const ImplicitConversionSequence &Conv = Cand->Conversions[I]; 4429 assert(Conv.isBad()); 4430 assert(Cand->Function && "for now, candidate must be a function"); 4431 FunctionDecl *Fn = Cand->Function; 4432 4433 // There's a conversion slot for the object argument if this is a 4434 // non-constructor method. Note that 'I' corresponds the 4435 // conversion-slot index. 4436 bool isObjectArgument = false; 4437 if (isa<CXXMethodDecl>(Fn) && !isa<CXXConstructorDecl>(Fn)) { 4438 if (I == 0) 4439 isObjectArgument = true; 4440 else 4441 I--; 4442 } 4443 4444 std::string FnDesc; 4445 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, FnDesc); 4446 4447 Expr *FromExpr = Conv.Bad.FromExpr; 4448 QualType FromTy = Conv.Bad.getFromType(); 4449 QualType ToTy = Conv.Bad.getToType(); 4450 4451 if (FromTy == S.Context.OverloadTy) { 4452 assert(FromExpr && "overload set argument came from implicit argument?"); 4453 Expr *E = FromExpr->IgnoreParens(); 4454 if (isa<UnaryOperator>(E)) 4455 E = cast<UnaryOperator>(E)->getSubExpr()->IgnoreParens(); 4456 DeclarationName Name = cast<OverloadExpr>(E)->getName(); 4457 4458 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_overload) 4459 << (unsigned) FnKind << FnDesc 4460 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 4461 << ToTy << Name << I+1; 4462 return; 4463 } 4464 4465 // Do some hand-waving analysis to see if the non-viability is due 4466 // to a qualifier mismatch. 4467 CanQualType CFromTy = S.Context.getCanonicalType(FromTy); 4468 CanQualType CToTy = S.Context.getCanonicalType(ToTy); 4469 if (CanQual<ReferenceType> RT = CToTy->getAs<ReferenceType>()) 4470 CToTy = RT->getPointeeType(); 4471 else { 4472 // TODO: detect and diagnose the full richness of const mismatches. 4473 if (CanQual<PointerType> FromPT = CFromTy->getAs<PointerType>()) 4474 if (CanQual<PointerType> ToPT = CToTy->getAs<PointerType>()) 4475 CFromTy = FromPT->getPointeeType(), CToTy = ToPT->getPointeeType(); 4476 } 4477 4478 if (CToTy.getUnqualifiedType() == CFromTy.getUnqualifiedType() && 4479 !CToTy.isAtLeastAsQualifiedAs(CFromTy)) { 4480 // It is dumb that we have to do this here. 4481 while (isa<ArrayType>(CFromTy)) 4482 CFromTy = CFromTy->getAs<ArrayType>()->getElementType(); 4483 while (isa<ArrayType>(CToTy)) 4484 CToTy = CFromTy->getAs<ArrayType>()->getElementType(); 4485 4486 Qualifiers FromQs = CFromTy.getQualifiers(); 4487 Qualifiers ToQs = CToTy.getQualifiers(); 4488 4489 if (FromQs.getAddressSpace() != ToQs.getAddressSpace()) { 4490 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_addrspace) 4491 << (unsigned) FnKind << FnDesc 4492 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 4493 << FromTy 4494 << FromQs.getAddressSpace() << ToQs.getAddressSpace() 4495 << (unsigned) isObjectArgument << I+1; 4496 return; 4497 } 4498 4499 unsigned CVR = FromQs.getCVRQualifiers() & ~ToQs.getCVRQualifiers(); 4500 assert(CVR && "unexpected qualifiers mismatch"); 4501 4502 if (isObjectArgument) { 4503 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr_this) 4504 << (unsigned) FnKind << FnDesc 4505 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 4506 << FromTy << (CVR - 1); 4507 } else { 4508 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr) 4509 << (unsigned) FnKind << FnDesc 4510 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 4511 << FromTy << (CVR - 1) << I+1; 4512 } 4513 return; 4514 } 4515 4516 // Diagnose references or pointers to incomplete types differently, 4517 // since it's far from impossible that the incompleteness triggered 4518 // the failure. 4519 QualType TempFromTy = FromTy.getNonReferenceType(); 4520 if (const PointerType *PTy = TempFromTy->getAs<PointerType>()) 4521 TempFromTy = PTy->getPointeeType(); 4522 if (TempFromTy->isIncompleteType()) { 4523 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_conv_incomplete) 4524 << (unsigned) FnKind << FnDesc 4525 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 4526 << FromTy << ToTy << (unsigned) isObjectArgument << I+1; 4527 return; 4528 } 4529 4530 // TODO: specialize more based on the kind of mismatch 4531 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_conv) 4532 << (unsigned) FnKind << FnDesc 4533 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 4534 << FromTy << ToTy << (unsigned) isObjectArgument << I+1; 4535} 4536 4537void DiagnoseArityMismatch(Sema &S, OverloadCandidate *Cand, 4538 unsigned NumFormalArgs) { 4539 // TODO: treat calls to a missing default constructor as a special case 4540 4541 FunctionDecl *Fn = Cand->Function; 4542 const FunctionProtoType *FnTy = Fn->getType()->getAs<FunctionProtoType>(); 4543 4544 unsigned MinParams = Fn->getMinRequiredArguments(); 4545 4546 // at least / at most / exactly 4547 unsigned mode, modeCount; 4548 if (NumFormalArgs < MinParams) { 4549 assert(Cand->FailureKind == ovl_fail_too_few_arguments); 4550 if (MinParams != FnTy->getNumArgs() || FnTy->isVariadic()) 4551 mode = 0; // "at least" 4552 else 4553 mode = 2; // "exactly" 4554 modeCount = MinParams; 4555 } else { 4556 assert(Cand->FailureKind == ovl_fail_too_many_arguments); 4557 if (MinParams != FnTy->getNumArgs()) 4558 mode = 1; // "at most" 4559 else 4560 mode = 2; // "exactly" 4561 modeCount = FnTy->getNumArgs(); 4562 } 4563 4564 std::string Description; 4565 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, Description); 4566 4567 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_arity) 4568 << (unsigned) FnKind << Description << mode << modeCount << NumFormalArgs; 4569} 4570 4571/// Diagnose a failed template-argument deduction. 4572void DiagnoseBadDeduction(Sema &S, OverloadCandidate *Cand, 4573 Expr **Args, unsigned NumArgs) { 4574 FunctionDecl *Fn = Cand->Function; // pattern 4575 4576 TemplateParameter Param = TemplateParameter::getFromOpaqueValue( 4577 Cand->DeductionFailure.TemplateParameter); 4578 4579 switch (Cand->DeductionFailure.Result) { 4580 case Sema::TDK_Success: 4581 llvm_unreachable("TDK_success while diagnosing bad deduction"); 4582 4583 case Sema::TDK_Incomplete: { 4584 NamedDecl *ParamD; 4585 (ParamD = Param.dyn_cast<TemplateTypeParmDecl*>()) || 4586 (ParamD = Param.dyn_cast<NonTypeTemplateParmDecl*>()) || 4587 (ParamD = Param.dyn_cast<TemplateTemplateParmDecl*>()); 4588 assert(ParamD && "no parameter found for incomplete deduction result"); 4589 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_incomplete_deduction) 4590 << ParamD->getDeclName(); 4591 return; 4592 } 4593 4594 // TODO: diagnose these individually, then kill off 4595 // note_ovl_candidate_bad_deduction, which is uselessly vague. 4596 case Sema::TDK_InstantiationDepth: 4597 case Sema::TDK_Inconsistent: 4598 case Sema::TDK_InconsistentQuals: 4599 case Sema::TDK_SubstitutionFailure: 4600 case Sema::TDK_NonDeducedMismatch: 4601 case Sema::TDK_TooManyArguments: 4602 case Sema::TDK_TooFewArguments: 4603 case Sema::TDK_InvalidExplicitArguments: 4604 case Sema::TDK_FailedOverloadResolution: 4605 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_deduction); 4606 return; 4607 } 4608} 4609 4610/// Generates a 'note' diagnostic for an overload candidate. We've 4611/// already generated a primary error at the call site. 4612/// 4613/// It really does need to be a single diagnostic with its caret 4614/// pointed at the candidate declaration. Yes, this creates some 4615/// major challenges of technical writing. Yes, this makes pointing 4616/// out problems with specific arguments quite awkward. It's still 4617/// better than generating twenty screens of text for every failed 4618/// overload. 4619/// 4620/// It would be great to be able to express per-candidate problems 4621/// more richly for those diagnostic clients that cared, but we'd 4622/// still have to be just as careful with the default diagnostics. 4623void NoteFunctionCandidate(Sema &S, OverloadCandidate *Cand, 4624 Expr **Args, unsigned NumArgs) { 4625 FunctionDecl *Fn = Cand->Function; 4626 4627 // Note deleted candidates, but only if they're viable. 4628 if (Cand->Viable && (Fn->isDeleted() || Fn->hasAttr<UnavailableAttr>())) { 4629 std::string FnDesc; 4630 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, FnDesc); 4631 4632 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_deleted) 4633 << FnKind << FnDesc << Fn->isDeleted(); 4634 return; 4635 } 4636 4637 // We don't really have anything else to say about viable candidates. 4638 if (Cand->Viable) { 4639 S.NoteOverloadCandidate(Fn); 4640 return; 4641 } 4642 4643 switch (Cand->FailureKind) { 4644 case ovl_fail_too_many_arguments: 4645 case ovl_fail_too_few_arguments: 4646 return DiagnoseArityMismatch(S, Cand, NumArgs); 4647 4648 case ovl_fail_bad_deduction: 4649 return DiagnoseBadDeduction(S, Cand, Args, NumArgs); 4650 4651 case ovl_fail_trivial_conversion: 4652 case ovl_fail_bad_final_conversion: 4653 return S.NoteOverloadCandidate(Fn); 4654 4655 case ovl_fail_bad_conversion: { 4656 unsigned I = (Cand->IgnoreObjectArgument ? 1 : 0); 4657 for (unsigned N = Cand->Conversions.size(); I != N; ++I) 4658 if (Cand->Conversions[I].isBad()) 4659 return DiagnoseBadConversion(S, Cand, I); 4660 4661 // FIXME: this currently happens when we're called from SemaInit 4662 // when user-conversion overload fails. Figure out how to handle 4663 // those conditions and diagnose them well. 4664 return S.NoteOverloadCandidate(Fn); 4665 } 4666 } 4667} 4668 4669void NoteSurrogateCandidate(Sema &S, OverloadCandidate *Cand) { 4670 // Desugar the type of the surrogate down to a function type, 4671 // retaining as many typedefs as possible while still showing 4672 // the function type (and, therefore, its parameter types). 4673 QualType FnType = Cand->Surrogate->getConversionType(); 4674 bool isLValueReference = false; 4675 bool isRValueReference = false; 4676 bool isPointer = false; 4677 if (const LValueReferenceType *FnTypeRef = 4678 FnType->getAs<LValueReferenceType>()) { 4679 FnType = FnTypeRef->getPointeeType(); 4680 isLValueReference = true; 4681 } else if (const RValueReferenceType *FnTypeRef = 4682 FnType->getAs<RValueReferenceType>()) { 4683 FnType = FnTypeRef->getPointeeType(); 4684 isRValueReference = true; 4685 } 4686 if (const PointerType *FnTypePtr = FnType->getAs<PointerType>()) { 4687 FnType = FnTypePtr->getPointeeType(); 4688 isPointer = true; 4689 } 4690 // Desugar down to a function type. 4691 FnType = QualType(FnType->getAs<FunctionType>(), 0); 4692 // Reconstruct the pointer/reference as appropriate. 4693 if (isPointer) FnType = S.Context.getPointerType(FnType); 4694 if (isRValueReference) FnType = S.Context.getRValueReferenceType(FnType); 4695 if (isLValueReference) FnType = S.Context.getLValueReferenceType(FnType); 4696 4697 S.Diag(Cand->Surrogate->getLocation(), diag::note_ovl_surrogate_cand) 4698 << FnType; 4699} 4700 4701void NoteBuiltinOperatorCandidate(Sema &S, 4702 const char *Opc, 4703 SourceLocation OpLoc, 4704 OverloadCandidate *Cand) { 4705 assert(Cand->Conversions.size() <= 2 && "builtin operator is not binary"); 4706 std::string TypeStr("operator"); 4707 TypeStr += Opc; 4708 TypeStr += "("; 4709 TypeStr += Cand->BuiltinTypes.ParamTypes[0].getAsString(); 4710 if (Cand->Conversions.size() == 1) { 4711 TypeStr += ")"; 4712 S.Diag(OpLoc, diag::note_ovl_builtin_unary_candidate) << TypeStr; 4713 } else { 4714 TypeStr += ", "; 4715 TypeStr += Cand->BuiltinTypes.ParamTypes[1].getAsString(); 4716 TypeStr += ")"; 4717 S.Diag(OpLoc, diag::note_ovl_builtin_binary_candidate) << TypeStr; 4718 } 4719} 4720 4721void NoteAmbiguousUserConversions(Sema &S, SourceLocation OpLoc, 4722 OverloadCandidate *Cand) { 4723 unsigned NoOperands = Cand->Conversions.size(); 4724 for (unsigned ArgIdx = 0; ArgIdx < NoOperands; ++ArgIdx) { 4725 const ImplicitConversionSequence &ICS = Cand->Conversions[ArgIdx]; 4726 if (ICS.isBad()) break; // all meaningless after first invalid 4727 if (!ICS.isAmbiguous()) continue; 4728 4729 S.DiagnoseAmbiguousConversion(ICS, OpLoc, 4730 PDiag(diag::note_ambiguous_type_conversion)); 4731 } 4732} 4733 4734SourceLocation GetLocationForCandidate(const OverloadCandidate *Cand) { 4735 if (Cand->Function) 4736 return Cand->Function->getLocation(); 4737 if (Cand->IsSurrogate) 4738 return Cand->Surrogate->getLocation(); 4739 return SourceLocation(); 4740} 4741 4742struct CompareOverloadCandidatesForDisplay { 4743 Sema &S; 4744 CompareOverloadCandidatesForDisplay(Sema &S) : S(S) {} 4745 4746 bool operator()(const OverloadCandidate *L, 4747 const OverloadCandidate *R) { 4748 // Fast-path this check. 4749 if (L == R) return false; 4750 4751 // Order first by viability. 4752 if (L->Viable) { 4753 if (!R->Viable) return true; 4754 4755 // TODO: introduce a tri-valued comparison for overload 4756 // candidates. Would be more worthwhile if we had a sort 4757 // that could exploit it. 4758 if (S.isBetterOverloadCandidate(*L, *R, SourceLocation())) return true; 4759 if (S.isBetterOverloadCandidate(*R, *L, SourceLocation())) return false; 4760 } else if (R->Viable) 4761 return false; 4762 4763 assert(L->Viable == R->Viable); 4764 4765 // Criteria by which we can sort non-viable candidates: 4766 if (!L->Viable) { 4767 // 1. Arity mismatches come after other candidates. 4768 if (L->FailureKind == ovl_fail_too_many_arguments || 4769 L->FailureKind == ovl_fail_too_few_arguments) 4770 return false; 4771 if (R->FailureKind == ovl_fail_too_many_arguments || 4772 R->FailureKind == ovl_fail_too_few_arguments) 4773 return true; 4774 4775 // 2. Bad conversions come first and are ordered by the number 4776 // of bad conversions and quality of good conversions. 4777 if (L->FailureKind == ovl_fail_bad_conversion) { 4778 if (R->FailureKind != ovl_fail_bad_conversion) 4779 return true; 4780 4781 // If there's any ordering between the defined conversions... 4782 // FIXME: this might not be transitive. 4783 assert(L->Conversions.size() == R->Conversions.size()); 4784 4785 int leftBetter = 0; 4786 unsigned I = (L->IgnoreObjectArgument || R->IgnoreObjectArgument); 4787 for (unsigned E = L->Conversions.size(); I != E; ++I) { 4788 switch (S.CompareImplicitConversionSequences(L->Conversions[I], 4789 R->Conversions[I])) { 4790 case ImplicitConversionSequence::Better: 4791 leftBetter++; 4792 break; 4793 4794 case ImplicitConversionSequence::Worse: 4795 leftBetter--; 4796 break; 4797 4798 case ImplicitConversionSequence::Indistinguishable: 4799 break; 4800 } 4801 } 4802 if (leftBetter > 0) return true; 4803 if (leftBetter < 0) return false; 4804 4805 } else if (R->FailureKind == ovl_fail_bad_conversion) 4806 return false; 4807 4808 // TODO: others? 4809 } 4810 4811 // Sort everything else by location. 4812 SourceLocation LLoc = GetLocationForCandidate(L); 4813 SourceLocation RLoc = GetLocationForCandidate(R); 4814 4815 // Put candidates without locations (e.g. builtins) at the end. 4816 if (LLoc.isInvalid()) return false; 4817 if (RLoc.isInvalid()) return true; 4818 4819 return S.SourceMgr.isBeforeInTranslationUnit(LLoc, RLoc); 4820 } 4821}; 4822 4823/// CompleteNonViableCandidate - Normally, overload resolution only 4824/// computes up to the first 4825void CompleteNonViableCandidate(Sema &S, OverloadCandidate *Cand, 4826 Expr **Args, unsigned NumArgs) { 4827 assert(!Cand->Viable); 4828 4829 // Don't do anything on failures other than bad conversion. 4830 if (Cand->FailureKind != ovl_fail_bad_conversion) return; 4831 4832 // Skip forward to the first bad conversion. 4833 unsigned ConvIdx = (Cand->IgnoreObjectArgument ? 1 : 0); 4834 unsigned ConvCount = Cand->Conversions.size(); 4835 while (true) { 4836 assert(ConvIdx != ConvCount && "no bad conversion in candidate"); 4837 ConvIdx++; 4838 if (Cand->Conversions[ConvIdx - 1].isBad()) 4839 break; 4840 } 4841 4842 if (ConvIdx == ConvCount) 4843 return; 4844 4845 assert(!Cand->Conversions[ConvIdx].isInitialized() && 4846 "remaining conversion is initialized?"); 4847 4848 // FIXME: these should probably be preserved from the overload 4849 // operation somehow. 4850 bool SuppressUserConversions = false; 4851 bool ForceRValue = false; 4852 4853 const FunctionProtoType* Proto; 4854 unsigned ArgIdx = ConvIdx; 4855 4856 if (Cand->IsSurrogate) { 4857 QualType ConvType 4858 = Cand->Surrogate->getConversionType().getNonReferenceType(); 4859 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 4860 ConvType = ConvPtrType->getPointeeType(); 4861 Proto = ConvType->getAs<FunctionProtoType>(); 4862 ArgIdx--; 4863 } else if (Cand->Function) { 4864 Proto = Cand->Function->getType()->getAs<FunctionProtoType>(); 4865 if (isa<CXXMethodDecl>(Cand->Function) && 4866 !isa<CXXConstructorDecl>(Cand->Function)) 4867 ArgIdx--; 4868 } else { 4869 // Builtin binary operator with a bad first conversion. 4870 assert(ConvCount <= 3); 4871 for (; ConvIdx != ConvCount; ++ConvIdx) 4872 Cand->Conversions[ConvIdx] 4873 = S.TryCopyInitialization(Args[ConvIdx], 4874 Cand->BuiltinTypes.ParamTypes[ConvIdx], 4875 SuppressUserConversions, ForceRValue, 4876 /*InOverloadResolution*/ true); 4877 return; 4878 } 4879 4880 // Fill in the rest of the conversions. 4881 unsigned NumArgsInProto = Proto->getNumArgs(); 4882 for (; ConvIdx != ConvCount; ++ConvIdx, ++ArgIdx) { 4883 if (ArgIdx < NumArgsInProto) 4884 Cand->Conversions[ConvIdx] 4885 = S.TryCopyInitialization(Args[ArgIdx], Proto->getArgType(ArgIdx), 4886 SuppressUserConversions, ForceRValue, 4887 /*InOverloadResolution=*/true); 4888 else 4889 Cand->Conversions[ConvIdx].setEllipsis(); 4890 } 4891} 4892 4893} // end anonymous namespace 4894 4895/// PrintOverloadCandidates - When overload resolution fails, prints 4896/// diagnostic messages containing the candidates in the candidate 4897/// set. 4898void 4899Sema::PrintOverloadCandidates(OverloadCandidateSet& CandidateSet, 4900 OverloadCandidateDisplayKind OCD, 4901 Expr **Args, unsigned NumArgs, 4902 const char *Opc, 4903 SourceLocation OpLoc) { 4904 // Sort the candidates by viability and position. Sorting directly would 4905 // be prohibitive, so we make a set of pointers and sort those. 4906 llvm::SmallVector<OverloadCandidate*, 32> Cands; 4907 if (OCD == OCD_AllCandidates) Cands.reserve(CandidateSet.size()); 4908 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 4909 LastCand = CandidateSet.end(); 4910 Cand != LastCand; ++Cand) { 4911 if (Cand->Viable) 4912 Cands.push_back(Cand); 4913 else if (OCD == OCD_AllCandidates) { 4914 CompleteNonViableCandidate(*this, Cand, Args, NumArgs); 4915 Cands.push_back(Cand); 4916 } 4917 } 4918 4919 std::sort(Cands.begin(), Cands.end(), 4920 CompareOverloadCandidatesForDisplay(*this)); 4921 4922 bool ReportedAmbiguousConversions = false; 4923 4924 llvm::SmallVectorImpl<OverloadCandidate*>::iterator I, E; 4925 for (I = Cands.begin(), E = Cands.end(); I != E; ++I) { 4926 OverloadCandidate *Cand = *I; 4927 4928 if (Cand->Function) 4929 NoteFunctionCandidate(*this, Cand, Args, NumArgs); 4930 else if (Cand->IsSurrogate) 4931 NoteSurrogateCandidate(*this, Cand); 4932 4933 // This a builtin candidate. We do not, in general, want to list 4934 // every possible builtin candidate. 4935 else if (Cand->Viable) { 4936 // Generally we only see ambiguities including viable builtin 4937 // operators if overload resolution got screwed up by an 4938 // ambiguous user-defined conversion. 4939 // 4940 // FIXME: It's quite possible for different conversions to see 4941 // different ambiguities, though. 4942 if (!ReportedAmbiguousConversions) { 4943 NoteAmbiguousUserConversions(*this, OpLoc, Cand); 4944 ReportedAmbiguousConversions = true; 4945 } 4946 4947 // If this is a viable builtin, print it. 4948 NoteBuiltinOperatorCandidate(*this, Opc, OpLoc, Cand); 4949 } 4950 } 4951} 4952 4953static bool CheckUnresolvedAccess(Sema &S, OverloadExpr *E, NamedDecl *D, 4954 AccessSpecifier AS) { 4955 if (isa<UnresolvedLookupExpr>(E)) 4956 return S.CheckUnresolvedLookupAccess(cast<UnresolvedLookupExpr>(E), D, AS); 4957 4958 return S.CheckUnresolvedMemberAccess(cast<UnresolvedMemberExpr>(E), D, AS); 4959} 4960 4961/// ResolveAddressOfOverloadedFunction - Try to resolve the address of 4962/// an overloaded function (C++ [over.over]), where @p From is an 4963/// expression with overloaded function type and @p ToType is the type 4964/// we're trying to resolve to. For example: 4965/// 4966/// @code 4967/// int f(double); 4968/// int f(int); 4969/// 4970/// int (*pfd)(double) = f; // selects f(double) 4971/// @endcode 4972/// 4973/// This routine returns the resulting FunctionDecl if it could be 4974/// resolved, and NULL otherwise. When @p Complain is true, this 4975/// routine will emit diagnostics if there is an error. 4976FunctionDecl * 4977Sema::ResolveAddressOfOverloadedFunction(Expr *From, QualType ToType, 4978 bool Complain) { 4979 QualType FunctionType = ToType; 4980 bool IsMember = false; 4981 if (const PointerType *ToTypePtr = ToType->getAs<PointerType>()) 4982 FunctionType = ToTypePtr->getPointeeType(); 4983 else if (const ReferenceType *ToTypeRef = ToType->getAs<ReferenceType>()) 4984 FunctionType = ToTypeRef->getPointeeType(); 4985 else if (const MemberPointerType *MemTypePtr = 4986 ToType->getAs<MemberPointerType>()) { 4987 FunctionType = MemTypePtr->getPointeeType(); 4988 IsMember = true; 4989 } 4990 4991 // We only look at pointers or references to functions. 4992 FunctionType = Context.getCanonicalType(FunctionType).getUnqualifiedType(); 4993 if (!FunctionType->isFunctionType()) 4994 return 0; 4995 4996 // Find the actual overloaded function declaration. 4997 if (From->getType() != Context.OverloadTy) 4998 return 0; 4999 5000 // C++ [over.over]p1: 5001 // [...] [Note: any redundant set of parentheses surrounding the 5002 // overloaded function name is ignored (5.1). ] 5003 // C++ [over.over]p1: 5004 // [...] The overloaded function name can be preceded by the & 5005 // operator. 5006 OverloadExpr *OvlExpr = OverloadExpr::find(From).getPointer(); 5007 TemplateArgumentListInfo ETABuffer, *ExplicitTemplateArgs = 0; 5008 if (OvlExpr->hasExplicitTemplateArgs()) { 5009 OvlExpr->getExplicitTemplateArgs().copyInto(ETABuffer); 5010 ExplicitTemplateArgs = &ETABuffer; 5011 } 5012 5013 // Look through all of the overloaded functions, searching for one 5014 // whose type matches exactly. 5015 UnresolvedSet<4> Matches; // contains only FunctionDecls 5016 bool FoundNonTemplateFunction = false; 5017 for (UnresolvedSetIterator I = OvlExpr->decls_begin(), 5018 E = OvlExpr->decls_end(); I != E; ++I) { 5019 // Look through any using declarations to find the underlying function. 5020 NamedDecl *Fn = (*I)->getUnderlyingDecl(); 5021 5022 // C++ [over.over]p3: 5023 // Non-member functions and static member functions match 5024 // targets of type "pointer-to-function" or "reference-to-function." 5025 // Nonstatic member functions match targets of 5026 // type "pointer-to-member-function." 5027 // Note that according to DR 247, the containing class does not matter. 5028 5029 if (FunctionTemplateDecl *FunctionTemplate 5030 = dyn_cast<FunctionTemplateDecl>(Fn)) { 5031 if (CXXMethodDecl *Method 5032 = dyn_cast<CXXMethodDecl>(FunctionTemplate->getTemplatedDecl())) { 5033 // Skip non-static function templates when converting to pointer, and 5034 // static when converting to member pointer. 5035 if (Method->isStatic() == IsMember) 5036 continue; 5037 } else if (IsMember) 5038 continue; 5039 5040 // C++ [over.over]p2: 5041 // If the name is a function template, template argument deduction is 5042 // done (14.8.2.2), and if the argument deduction succeeds, the 5043 // resulting template argument list is used to generate a single 5044 // function template specialization, which is added to the set of 5045 // overloaded functions considered. 5046 // FIXME: We don't really want to build the specialization here, do we? 5047 FunctionDecl *Specialization = 0; 5048 TemplateDeductionInfo Info(Context, OvlExpr->getNameLoc()); 5049 if (TemplateDeductionResult Result 5050 = DeduceTemplateArguments(FunctionTemplate, ExplicitTemplateArgs, 5051 FunctionType, Specialization, Info)) { 5052 // FIXME: make a note of the failed deduction for diagnostics. 5053 (void)Result; 5054 } else { 5055 // FIXME: If the match isn't exact, shouldn't we just drop this as 5056 // a candidate? Find a testcase before changing the code. 5057 assert(FunctionType 5058 == Context.getCanonicalType(Specialization->getType())); 5059 Matches.addDecl(cast<FunctionDecl>(Specialization->getCanonicalDecl()), 5060 I.getAccess()); 5061 } 5062 5063 continue; 5064 } 5065 5066 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 5067 // Skip non-static functions when converting to pointer, and static 5068 // when converting to member pointer. 5069 if (Method->isStatic() == IsMember) 5070 continue; 5071 5072 // If we have explicit template arguments, skip non-templates. 5073 if (OvlExpr->hasExplicitTemplateArgs()) 5074 continue; 5075 } else if (IsMember) 5076 continue; 5077 5078 if (FunctionDecl *FunDecl = dyn_cast<FunctionDecl>(Fn)) { 5079 QualType ResultTy; 5080 if (Context.hasSameUnqualifiedType(FunctionType, FunDecl->getType()) || 5081 IsNoReturnConversion(Context, FunDecl->getType(), FunctionType, 5082 ResultTy)) { 5083 Matches.addDecl(cast<FunctionDecl>(FunDecl->getCanonicalDecl()), 5084 I.getAccess()); 5085 FoundNonTemplateFunction = true; 5086 } 5087 } 5088 } 5089 5090 // If there were 0 or 1 matches, we're done. 5091 if (Matches.empty()) 5092 return 0; 5093 else if (Matches.size() == 1) { 5094 FunctionDecl *Result = cast<FunctionDecl>(*Matches.begin()); 5095 MarkDeclarationReferenced(From->getLocStart(), Result); 5096 if (Complain) 5097 CheckUnresolvedAccess(*this, OvlExpr, Result, Matches.begin().getAccess()); 5098 return Result; 5099 } 5100 5101 // C++ [over.over]p4: 5102 // If more than one function is selected, [...] 5103 if (!FoundNonTemplateFunction) { 5104 // [...] and any given function template specialization F1 is 5105 // eliminated if the set contains a second function template 5106 // specialization whose function template is more specialized 5107 // than the function template of F1 according to the partial 5108 // ordering rules of 14.5.5.2. 5109 5110 // The algorithm specified above is quadratic. We instead use a 5111 // two-pass algorithm (similar to the one used to identify the 5112 // best viable function in an overload set) that identifies the 5113 // best function template (if it exists). 5114 5115 UnresolvedSetIterator Result = 5116 getMostSpecialized(Matches.begin(), Matches.end(), 5117 TPOC_Other, From->getLocStart(), 5118 PDiag(), 5119 PDiag(diag::err_addr_ovl_ambiguous) 5120 << Matches[0]->getDeclName(), 5121 PDiag(diag::note_ovl_candidate) 5122 << (unsigned) oc_function_template); 5123 assert(Result != Matches.end() && "no most-specialized template"); 5124 MarkDeclarationReferenced(From->getLocStart(), *Result); 5125 if (Complain) 5126 CheckUnresolvedAccess(*this, OvlExpr, *Result, Result.getAccess()); 5127 return cast<FunctionDecl>(*Result); 5128 } 5129 5130 // [...] any function template specializations in the set are 5131 // eliminated if the set also contains a non-template function, [...] 5132 for (unsigned I = 0, N = Matches.size(); I != N; ) { 5133 if (cast<FunctionDecl>(Matches[I].getDecl())->getPrimaryTemplate() == 0) 5134 ++I; 5135 else { 5136 Matches.erase(I); 5137 --N; 5138 } 5139 } 5140 5141 // [...] After such eliminations, if any, there shall remain exactly one 5142 // selected function. 5143 if (Matches.size() == 1) { 5144 UnresolvedSetIterator Match = Matches.begin(); 5145 MarkDeclarationReferenced(From->getLocStart(), *Match); 5146 if (Complain) 5147 CheckUnresolvedAccess(*this, OvlExpr, *Match, Match.getAccess()); 5148 return cast<FunctionDecl>(*Match); 5149 } 5150 5151 // FIXME: We should probably return the same thing that BestViableFunction 5152 // returns (even if we issue the diagnostics here). 5153 Diag(From->getLocStart(), diag::err_addr_ovl_ambiguous) 5154 << Matches[0]->getDeclName(); 5155 for (UnresolvedSetIterator I = Matches.begin(), 5156 E = Matches.end(); I != E; ++I) 5157 NoteOverloadCandidate(cast<FunctionDecl>(*I)); 5158 return 0; 5159} 5160 5161/// \brief Given an expression that refers to an overloaded function, try to 5162/// resolve that overloaded function expression down to a single function. 5163/// 5164/// This routine can only resolve template-ids that refer to a single function 5165/// template, where that template-id refers to a single template whose template 5166/// arguments are either provided by the template-id or have defaults, 5167/// as described in C++0x [temp.arg.explicit]p3. 5168FunctionDecl *Sema::ResolveSingleFunctionTemplateSpecialization(Expr *From) { 5169 // C++ [over.over]p1: 5170 // [...] [Note: any redundant set of parentheses surrounding the 5171 // overloaded function name is ignored (5.1). ] 5172 // C++ [over.over]p1: 5173 // [...] The overloaded function name can be preceded by the & 5174 // operator. 5175 5176 if (From->getType() != Context.OverloadTy) 5177 return 0; 5178 5179 OverloadExpr *OvlExpr = OverloadExpr::find(From).getPointer(); 5180 5181 // If we didn't actually find any template-ids, we're done. 5182 if (!OvlExpr->hasExplicitTemplateArgs()) 5183 return 0; 5184 5185 TemplateArgumentListInfo ExplicitTemplateArgs; 5186 OvlExpr->getExplicitTemplateArgs().copyInto(ExplicitTemplateArgs); 5187 5188 // Look through all of the overloaded functions, searching for one 5189 // whose type matches exactly. 5190 FunctionDecl *Matched = 0; 5191 for (UnresolvedSetIterator I = OvlExpr->decls_begin(), 5192 E = OvlExpr->decls_end(); I != E; ++I) { 5193 // C++0x [temp.arg.explicit]p3: 5194 // [...] In contexts where deduction is done and fails, or in contexts 5195 // where deduction is not done, if a template argument list is 5196 // specified and it, along with any default template arguments, 5197 // identifies a single function template specialization, then the 5198 // template-id is an lvalue for the function template specialization. 5199 FunctionTemplateDecl *FunctionTemplate = cast<FunctionTemplateDecl>(*I); 5200 5201 // C++ [over.over]p2: 5202 // If the name is a function template, template argument deduction is 5203 // done (14.8.2.2), and if the argument deduction succeeds, the 5204 // resulting template argument list is used to generate a single 5205 // function template specialization, which is added to the set of 5206 // overloaded functions considered. 5207 FunctionDecl *Specialization = 0; 5208 TemplateDeductionInfo Info(Context, OvlExpr->getNameLoc()); 5209 if (TemplateDeductionResult Result 5210 = DeduceTemplateArguments(FunctionTemplate, &ExplicitTemplateArgs, 5211 Specialization, Info)) { 5212 // FIXME: make a note of the failed deduction for diagnostics. 5213 (void)Result; 5214 continue; 5215 } 5216 5217 // Multiple matches; we can't resolve to a single declaration. 5218 if (Matched) 5219 return 0; 5220 5221 Matched = Specialization; 5222 } 5223 5224 return Matched; 5225} 5226 5227/// \brief Add a single candidate to the overload set. 5228static void AddOverloadedCallCandidate(Sema &S, 5229 NamedDecl *Callee, 5230 AccessSpecifier Access, 5231 const TemplateArgumentListInfo *ExplicitTemplateArgs, 5232 Expr **Args, unsigned NumArgs, 5233 OverloadCandidateSet &CandidateSet, 5234 bool PartialOverloading) { 5235 if (isa<UsingShadowDecl>(Callee)) 5236 Callee = cast<UsingShadowDecl>(Callee)->getTargetDecl(); 5237 5238 if (FunctionDecl *Func = dyn_cast<FunctionDecl>(Callee)) { 5239 assert(!ExplicitTemplateArgs && "Explicit template arguments?"); 5240 S.AddOverloadCandidate(Func, Access, Args, NumArgs, CandidateSet, 5241 false, false, PartialOverloading); 5242 return; 5243 } 5244 5245 if (FunctionTemplateDecl *FuncTemplate 5246 = dyn_cast<FunctionTemplateDecl>(Callee)) { 5247 S.AddTemplateOverloadCandidate(FuncTemplate, Access, ExplicitTemplateArgs, 5248 Args, NumArgs, CandidateSet); 5249 return; 5250 } 5251 5252 assert(false && "unhandled case in overloaded call candidate"); 5253 5254 // do nothing? 5255} 5256 5257/// \brief Add the overload candidates named by callee and/or found by argument 5258/// dependent lookup to the given overload set. 5259void Sema::AddOverloadedCallCandidates(UnresolvedLookupExpr *ULE, 5260 Expr **Args, unsigned NumArgs, 5261 OverloadCandidateSet &CandidateSet, 5262 bool PartialOverloading) { 5263 5264#ifndef NDEBUG 5265 // Verify that ArgumentDependentLookup is consistent with the rules 5266 // in C++0x [basic.lookup.argdep]p3: 5267 // 5268 // Let X be the lookup set produced by unqualified lookup (3.4.1) 5269 // and let Y be the lookup set produced by argument dependent 5270 // lookup (defined as follows). If X contains 5271 // 5272 // -- a declaration of a class member, or 5273 // 5274 // -- a block-scope function declaration that is not a 5275 // using-declaration, or 5276 // 5277 // -- a declaration that is neither a function or a function 5278 // template 5279 // 5280 // then Y is empty. 5281 5282 if (ULE->requiresADL()) { 5283 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(), 5284 E = ULE->decls_end(); I != E; ++I) { 5285 assert(!(*I)->getDeclContext()->isRecord()); 5286 assert(isa<UsingShadowDecl>(*I) || 5287 !(*I)->getDeclContext()->isFunctionOrMethod()); 5288 assert((*I)->getUnderlyingDecl()->isFunctionOrFunctionTemplate()); 5289 } 5290 } 5291#endif 5292 5293 // It would be nice to avoid this copy. 5294 TemplateArgumentListInfo TABuffer; 5295 const TemplateArgumentListInfo *ExplicitTemplateArgs = 0; 5296 if (ULE->hasExplicitTemplateArgs()) { 5297 ULE->copyTemplateArgumentsInto(TABuffer); 5298 ExplicitTemplateArgs = &TABuffer; 5299 } 5300 5301 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(), 5302 E = ULE->decls_end(); I != E; ++I) 5303 AddOverloadedCallCandidate(*this, *I, I.getAccess(), ExplicitTemplateArgs, 5304 Args, NumArgs, CandidateSet, 5305 PartialOverloading); 5306 5307 if (ULE->requiresADL()) 5308 AddArgumentDependentLookupCandidates(ULE->getName(), /*Operator*/ false, 5309 Args, NumArgs, 5310 ExplicitTemplateArgs, 5311 CandidateSet, 5312 PartialOverloading); 5313} 5314 5315static Sema::OwningExprResult Destroy(Sema &SemaRef, Expr *Fn, 5316 Expr **Args, unsigned NumArgs) { 5317 Fn->Destroy(SemaRef.Context); 5318 for (unsigned Arg = 0; Arg < NumArgs; ++Arg) 5319 Args[Arg]->Destroy(SemaRef.Context); 5320 return SemaRef.ExprError(); 5321} 5322 5323/// Attempts to recover from a call where no functions were found. 5324/// 5325/// Returns true if new candidates were found. 5326static Sema::OwningExprResult 5327BuildRecoveryCallExpr(Sema &SemaRef, Expr *Fn, 5328 UnresolvedLookupExpr *ULE, 5329 SourceLocation LParenLoc, 5330 Expr **Args, unsigned NumArgs, 5331 SourceLocation *CommaLocs, 5332 SourceLocation RParenLoc) { 5333 5334 CXXScopeSpec SS; 5335 if (ULE->getQualifier()) { 5336 SS.setScopeRep(ULE->getQualifier()); 5337 SS.setRange(ULE->getQualifierRange()); 5338 } 5339 5340 TemplateArgumentListInfo TABuffer; 5341 const TemplateArgumentListInfo *ExplicitTemplateArgs = 0; 5342 if (ULE->hasExplicitTemplateArgs()) { 5343 ULE->copyTemplateArgumentsInto(TABuffer); 5344 ExplicitTemplateArgs = &TABuffer; 5345 } 5346 5347 LookupResult R(SemaRef, ULE->getName(), ULE->getNameLoc(), 5348 Sema::LookupOrdinaryName); 5349 if (SemaRef.DiagnoseEmptyLookup(/*Scope=*/0, SS, R)) 5350 return Destroy(SemaRef, Fn, Args, NumArgs); 5351 5352 assert(!R.empty() && "lookup results empty despite recovery"); 5353 5354 // Build an implicit member call if appropriate. Just drop the 5355 // casts and such from the call, we don't really care. 5356 Sema::OwningExprResult NewFn = SemaRef.ExprError(); 5357 if ((*R.begin())->isCXXClassMember()) 5358 NewFn = SemaRef.BuildPossibleImplicitMemberExpr(SS, R, ExplicitTemplateArgs); 5359 else if (ExplicitTemplateArgs) 5360 NewFn = SemaRef.BuildTemplateIdExpr(SS, R, false, *ExplicitTemplateArgs); 5361 else 5362 NewFn = SemaRef.BuildDeclarationNameExpr(SS, R, false); 5363 5364 if (NewFn.isInvalid()) 5365 return Destroy(SemaRef, Fn, Args, NumArgs); 5366 5367 Fn->Destroy(SemaRef.Context); 5368 5369 // This shouldn't cause an infinite loop because we're giving it 5370 // an expression with non-empty lookup results, which should never 5371 // end up here. 5372 return SemaRef.ActOnCallExpr(/*Scope*/ 0, move(NewFn), LParenLoc, 5373 Sema::MultiExprArg(SemaRef, (void**) Args, NumArgs), 5374 CommaLocs, RParenLoc); 5375} 5376 5377/// ResolveOverloadedCallFn - Given the call expression that calls Fn 5378/// (which eventually refers to the declaration Func) and the call 5379/// arguments Args/NumArgs, attempt to resolve the function call down 5380/// to a specific function. If overload resolution succeeds, returns 5381/// the function declaration produced by overload 5382/// resolution. Otherwise, emits diagnostics, deletes all of the 5383/// arguments and Fn, and returns NULL. 5384Sema::OwningExprResult 5385Sema::BuildOverloadedCallExpr(Expr *Fn, UnresolvedLookupExpr *ULE, 5386 SourceLocation LParenLoc, 5387 Expr **Args, unsigned NumArgs, 5388 SourceLocation *CommaLocs, 5389 SourceLocation RParenLoc) { 5390#ifndef NDEBUG 5391 if (ULE->requiresADL()) { 5392 // To do ADL, we must have found an unqualified name. 5393 assert(!ULE->getQualifier() && "qualified name with ADL"); 5394 5395 // We don't perform ADL for implicit declarations of builtins. 5396 // Verify that this was correctly set up. 5397 FunctionDecl *F; 5398 if (ULE->decls_begin() + 1 == ULE->decls_end() && 5399 (F = dyn_cast<FunctionDecl>(*ULE->decls_begin())) && 5400 F->getBuiltinID() && F->isImplicit()) 5401 assert(0 && "performing ADL for builtin"); 5402 5403 // We don't perform ADL in C. 5404 assert(getLangOptions().CPlusPlus && "ADL enabled in C"); 5405 } 5406#endif 5407 5408 OverloadCandidateSet CandidateSet(Fn->getExprLoc()); 5409 5410 // Add the functions denoted by the callee to the set of candidate 5411 // functions, including those from argument-dependent lookup. 5412 AddOverloadedCallCandidates(ULE, Args, NumArgs, CandidateSet); 5413 5414 // If we found nothing, try to recover. 5415 // AddRecoveryCallCandidates diagnoses the error itself, so we just 5416 // bailout out if it fails. 5417 if (CandidateSet.empty()) 5418 return BuildRecoveryCallExpr(*this, Fn, ULE, LParenLoc, Args, NumArgs, 5419 CommaLocs, RParenLoc); 5420 5421 OverloadCandidateSet::iterator Best; 5422 switch (BestViableFunction(CandidateSet, Fn->getLocStart(), Best)) { 5423 case OR_Success: { 5424 FunctionDecl *FDecl = Best->Function; 5425 CheckUnresolvedLookupAccess(ULE, FDecl, Best->getAccess()); 5426 Fn = FixOverloadedFunctionReference(Fn, FDecl); 5427 return BuildResolvedCallExpr(Fn, FDecl, LParenLoc, Args, NumArgs, RParenLoc); 5428 } 5429 5430 case OR_No_Viable_Function: 5431 Diag(Fn->getSourceRange().getBegin(), 5432 diag::err_ovl_no_viable_function_in_call) 5433 << ULE->getName() << Fn->getSourceRange(); 5434 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 5435 break; 5436 5437 case OR_Ambiguous: 5438 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_ambiguous_call) 5439 << ULE->getName() << Fn->getSourceRange(); 5440 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, NumArgs); 5441 break; 5442 5443 case OR_Deleted: 5444 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_deleted_call) 5445 << Best->Function->isDeleted() 5446 << ULE->getName() 5447 << Fn->getSourceRange(); 5448 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 5449 break; 5450 } 5451 5452 // Overload resolution failed. Destroy all of the subexpressions and 5453 // return NULL. 5454 Fn->Destroy(Context); 5455 for (unsigned Arg = 0; Arg < NumArgs; ++Arg) 5456 Args[Arg]->Destroy(Context); 5457 return ExprError(); 5458} 5459 5460static bool IsOverloaded(const UnresolvedSetImpl &Functions) { 5461 return Functions.size() > 1 || 5462 (Functions.size() == 1 && isa<FunctionTemplateDecl>(*Functions.begin())); 5463} 5464 5465/// \brief Create a unary operation that may resolve to an overloaded 5466/// operator. 5467/// 5468/// \param OpLoc The location of the operator itself (e.g., '*'). 5469/// 5470/// \param OpcIn The UnaryOperator::Opcode that describes this 5471/// operator. 5472/// 5473/// \param Functions The set of non-member functions that will be 5474/// considered by overload resolution. The caller needs to build this 5475/// set based on the context using, e.g., 5476/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 5477/// set should not contain any member functions; those will be added 5478/// by CreateOverloadedUnaryOp(). 5479/// 5480/// \param input The input argument. 5481Sema::OwningExprResult 5482Sema::CreateOverloadedUnaryOp(SourceLocation OpLoc, unsigned OpcIn, 5483 const UnresolvedSetImpl &Fns, 5484 ExprArg input) { 5485 UnaryOperator::Opcode Opc = static_cast<UnaryOperator::Opcode>(OpcIn); 5486 Expr *Input = (Expr *)input.get(); 5487 5488 OverloadedOperatorKind Op = UnaryOperator::getOverloadedOperator(Opc); 5489 assert(Op != OO_None && "Invalid opcode for overloaded unary operator"); 5490 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 5491 5492 Expr *Args[2] = { Input, 0 }; 5493 unsigned NumArgs = 1; 5494 5495 // For post-increment and post-decrement, add the implicit '0' as 5496 // the second argument, so that we know this is a post-increment or 5497 // post-decrement. 5498 if (Opc == UnaryOperator::PostInc || Opc == UnaryOperator::PostDec) { 5499 llvm::APSInt Zero(Context.getTypeSize(Context.IntTy), false); 5500 Args[1] = new (Context) IntegerLiteral(Zero, Context.IntTy, 5501 SourceLocation()); 5502 NumArgs = 2; 5503 } 5504 5505 if (Input->isTypeDependent()) { 5506 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 5507 UnresolvedLookupExpr *Fn 5508 = UnresolvedLookupExpr::Create(Context, /*Dependent*/ true, NamingClass, 5509 0, SourceRange(), OpName, OpLoc, 5510 /*ADL*/ true, IsOverloaded(Fns)); 5511 Fn->addDecls(Fns.begin(), Fns.end()); 5512 5513 input.release(); 5514 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 5515 &Args[0], NumArgs, 5516 Context.DependentTy, 5517 OpLoc)); 5518 } 5519 5520 // Build an empty overload set. 5521 OverloadCandidateSet CandidateSet(OpLoc); 5522 5523 // Add the candidates from the given function set. 5524 AddFunctionCandidates(Fns, &Args[0], NumArgs, CandidateSet, false); 5525 5526 // Add operator candidates that are member functions. 5527 AddMemberOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 5528 5529 // Add candidates from ADL. 5530 AddArgumentDependentLookupCandidates(OpName, /*Operator*/ true, 5531 Args, NumArgs, 5532 /*ExplicitTemplateArgs*/ 0, 5533 CandidateSet); 5534 5535 // Add builtin operator candidates. 5536 AddBuiltinOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 5537 5538 // Perform overload resolution. 5539 OverloadCandidateSet::iterator Best; 5540 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 5541 case OR_Success: { 5542 // We found a built-in operator or an overloaded operator. 5543 FunctionDecl *FnDecl = Best->Function; 5544 5545 if (FnDecl) { 5546 // We matched an overloaded operator. Build a call to that 5547 // operator. 5548 5549 // Convert the arguments. 5550 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 5551 CheckMemberOperatorAccess(OpLoc, Args[0], Method, Best->getAccess()); 5552 5553 if (PerformObjectArgumentInitialization(Input, /*Qualifier=*/0, Method)) 5554 return ExprError(); 5555 } else { 5556 // Convert the arguments. 5557 OwningExprResult InputInit 5558 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 5559 FnDecl->getParamDecl(0)), 5560 SourceLocation(), 5561 move(input)); 5562 if (InputInit.isInvalid()) 5563 return ExprError(); 5564 5565 input = move(InputInit); 5566 Input = (Expr *)input.get(); 5567 } 5568 5569 // Determine the result type 5570 QualType ResultTy = FnDecl->getResultType().getNonReferenceType(); 5571 5572 // Build the actual expression node. 5573 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 5574 SourceLocation()); 5575 UsualUnaryConversions(FnExpr); 5576 5577 input.release(); 5578 Args[0] = Input; 5579 ExprOwningPtr<CallExpr> TheCall(this, 5580 new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 5581 Args, NumArgs, ResultTy, OpLoc)); 5582 5583 if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall.get(), 5584 FnDecl)) 5585 return ExprError(); 5586 5587 return MaybeBindToTemporary(TheCall.release()); 5588 } else { 5589 // We matched a built-in operator. Convert the arguments, then 5590 // break out so that we will build the appropriate built-in 5591 // operator node. 5592 if (PerformImplicitConversion(Input, Best->BuiltinTypes.ParamTypes[0], 5593 Best->Conversions[0], AA_Passing)) 5594 return ExprError(); 5595 5596 break; 5597 } 5598 } 5599 5600 case OR_No_Viable_Function: 5601 // No viable function; fall through to handling this as a 5602 // built-in operator, which will produce an error message for us. 5603 break; 5604 5605 case OR_Ambiguous: 5606 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 5607 << UnaryOperator::getOpcodeStr(Opc) 5608 << Input->getSourceRange(); 5609 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, NumArgs, 5610 UnaryOperator::getOpcodeStr(Opc), OpLoc); 5611 return ExprError(); 5612 5613 case OR_Deleted: 5614 Diag(OpLoc, diag::err_ovl_deleted_oper) 5615 << Best->Function->isDeleted() 5616 << UnaryOperator::getOpcodeStr(Opc) 5617 << Input->getSourceRange(); 5618 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 5619 return ExprError(); 5620 } 5621 5622 // Either we found no viable overloaded operator or we matched a 5623 // built-in operator. In either case, fall through to trying to 5624 // build a built-in operation. 5625 input.release(); 5626 return CreateBuiltinUnaryOp(OpLoc, Opc, Owned(Input)); 5627} 5628 5629/// \brief Create a binary operation that may resolve to an overloaded 5630/// operator. 5631/// 5632/// \param OpLoc The location of the operator itself (e.g., '+'). 5633/// 5634/// \param OpcIn The BinaryOperator::Opcode that describes this 5635/// operator. 5636/// 5637/// \param Functions The set of non-member functions that will be 5638/// considered by overload resolution. The caller needs to build this 5639/// set based on the context using, e.g., 5640/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 5641/// set should not contain any member functions; those will be added 5642/// by CreateOverloadedBinOp(). 5643/// 5644/// \param LHS Left-hand argument. 5645/// \param RHS Right-hand argument. 5646Sema::OwningExprResult 5647Sema::CreateOverloadedBinOp(SourceLocation OpLoc, 5648 unsigned OpcIn, 5649 const UnresolvedSetImpl &Fns, 5650 Expr *LHS, Expr *RHS) { 5651 Expr *Args[2] = { LHS, RHS }; 5652 LHS=RHS=0; //Please use only Args instead of LHS/RHS couple 5653 5654 BinaryOperator::Opcode Opc = static_cast<BinaryOperator::Opcode>(OpcIn); 5655 OverloadedOperatorKind Op = BinaryOperator::getOverloadedOperator(Opc); 5656 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 5657 5658 // If either side is type-dependent, create an appropriate dependent 5659 // expression. 5660 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 5661 if (Fns.empty()) { 5662 // If there are no functions to store, just build a dependent 5663 // BinaryOperator or CompoundAssignment. 5664 if (Opc <= BinaryOperator::Assign || Opc > BinaryOperator::OrAssign) 5665 return Owned(new (Context) BinaryOperator(Args[0], Args[1], Opc, 5666 Context.DependentTy, OpLoc)); 5667 5668 return Owned(new (Context) CompoundAssignOperator(Args[0], Args[1], Opc, 5669 Context.DependentTy, 5670 Context.DependentTy, 5671 Context.DependentTy, 5672 OpLoc)); 5673 } 5674 5675 // FIXME: save results of ADL from here? 5676 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 5677 UnresolvedLookupExpr *Fn 5678 = UnresolvedLookupExpr::Create(Context, /*Dependent*/ true, NamingClass, 5679 0, SourceRange(), OpName, OpLoc, 5680 /*ADL*/ true, IsOverloaded(Fns)); 5681 5682 Fn->addDecls(Fns.begin(), Fns.end()); 5683 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 5684 Args, 2, 5685 Context.DependentTy, 5686 OpLoc)); 5687 } 5688 5689 // If this is the .* operator, which is not overloadable, just 5690 // create a built-in binary operator. 5691 if (Opc == BinaryOperator::PtrMemD) 5692 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 5693 5694 // If this is the assignment operator, we only perform overload resolution 5695 // if the left-hand side is a class or enumeration type. This is actually 5696 // a hack. The standard requires that we do overload resolution between the 5697 // various built-in candidates, but as DR507 points out, this can lead to 5698 // problems. So we do it this way, which pretty much follows what GCC does. 5699 // Note that we go the traditional code path for compound assignment forms. 5700 if (Opc==BinaryOperator::Assign && !Args[0]->getType()->isOverloadableType()) 5701 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 5702 5703 // Build an empty overload set. 5704 OverloadCandidateSet CandidateSet(OpLoc); 5705 5706 // Add the candidates from the given function set. 5707 AddFunctionCandidates(Fns, Args, 2, CandidateSet, false); 5708 5709 // Add operator candidates that are member functions. 5710 AddMemberOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 5711 5712 // Add candidates from ADL. 5713 AddArgumentDependentLookupCandidates(OpName, /*Operator*/ true, 5714 Args, 2, 5715 /*ExplicitTemplateArgs*/ 0, 5716 CandidateSet); 5717 5718 // Add builtin operator candidates. 5719 AddBuiltinOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 5720 5721 // Perform overload resolution. 5722 OverloadCandidateSet::iterator Best; 5723 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 5724 case OR_Success: { 5725 // We found a built-in operator or an overloaded operator. 5726 FunctionDecl *FnDecl = Best->Function; 5727 5728 if (FnDecl) { 5729 // We matched an overloaded operator. Build a call to that 5730 // operator. 5731 5732 // Convert the arguments. 5733 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 5734 // Best->Access is only meaningful for class members. 5735 CheckMemberOperatorAccess(OpLoc, Args[0], Method, Best->getAccess()); 5736 5737 OwningExprResult Arg1 5738 = PerformCopyInitialization( 5739 InitializedEntity::InitializeParameter( 5740 FnDecl->getParamDecl(0)), 5741 SourceLocation(), 5742 Owned(Args[1])); 5743 if (Arg1.isInvalid()) 5744 return ExprError(); 5745 5746 if (PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/0, 5747 Method)) 5748 return ExprError(); 5749 5750 Args[1] = RHS = Arg1.takeAs<Expr>(); 5751 } else { 5752 // Convert the arguments. 5753 OwningExprResult Arg0 5754 = PerformCopyInitialization( 5755 InitializedEntity::InitializeParameter( 5756 FnDecl->getParamDecl(0)), 5757 SourceLocation(), 5758 Owned(Args[0])); 5759 if (Arg0.isInvalid()) 5760 return ExprError(); 5761 5762 OwningExprResult Arg1 5763 = PerformCopyInitialization( 5764 InitializedEntity::InitializeParameter( 5765 FnDecl->getParamDecl(1)), 5766 SourceLocation(), 5767 Owned(Args[1])); 5768 if (Arg1.isInvalid()) 5769 return ExprError(); 5770 Args[0] = LHS = Arg0.takeAs<Expr>(); 5771 Args[1] = RHS = Arg1.takeAs<Expr>(); 5772 } 5773 5774 // Determine the result type 5775 QualType ResultTy 5776 = FnDecl->getType()->getAs<FunctionType>()->getResultType(); 5777 ResultTy = ResultTy.getNonReferenceType(); 5778 5779 // Build the actual expression node. 5780 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 5781 OpLoc); 5782 UsualUnaryConversions(FnExpr); 5783 5784 ExprOwningPtr<CXXOperatorCallExpr> 5785 TheCall(this, new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 5786 Args, 2, ResultTy, 5787 OpLoc)); 5788 5789 if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall.get(), 5790 FnDecl)) 5791 return ExprError(); 5792 5793 return MaybeBindToTemporary(TheCall.release()); 5794 } else { 5795 // We matched a built-in operator. Convert the arguments, then 5796 // break out so that we will build the appropriate built-in 5797 // operator node. 5798 if (PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 5799 Best->Conversions[0], AA_Passing) || 5800 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 5801 Best->Conversions[1], AA_Passing)) 5802 return ExprError(); 5803 5804 break; 5805 } 5806 } 5807 5808 case OR_No_Viable_Function: { 5809 // C++ [over.match.oper]p9: 5810 // If the operator is the operator , [...] and there are no 5811 // viable functions, then the operator is assumed to be the 5812 // built-in operator and interpreted according to clause 5. 5813 if (Opc == BinaryOperator::Comma) 5814 break; 5815 5816 // For class as left operand for assignment or compound assigment operator 5817 // do not fall through to handling in built-in, but report that no overloaded 5818 // assignment operator found 5819 OwningExprResult Result = ExprError(); 5820 if (Args[0]->getType()->isRecordType() && 5821 Opc >= BinaryOperator::Assign && Opc <= BinaryOperator::OrAssign) { 5822 Diag(OpLoc, diag::err_ovl_no_viable_oper) 5823 << BinaryOperator::getOpcodeStr(Opc) 5824 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 5825 } else { 5826 // No viable function; try to create a built-in operation, which will 5827 // produce an error. Then, show the non-viable candidates. 5828 Result = CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 5829 } 5830 assert(Result.isInvalid() && 5831 "C++ binary operator overloading is missing candidates!"); 5832 if (Result.isInvalid()) 5833 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2, 5834 BinaryOperator::getOpcodeStr(Opc), OpLoc); 5835 return move(Result); 5836 } 5837 5838 case OR_Ambiguous: 5839 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 5840 << BinaryOperator::getOpcodeStr(Opc) 5841 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 5842 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, 2, 5843 BinaryOperator::getOpcodeStr(Opc), OpLoc); 5844 return ExprError(); 5845 5846 case OR_Deleted: 5847 Diag(OpLoc, diag::err_ovl_deleted_oper) 5848 << Best->Function->isDeleted() 5849 << BinaryOperator::getOpcodeStr(Opc) 5850 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 5851 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2); 5852 return ExprError(); 5853 } 5854 5855 // We matched a built-in operator; build it. 5856 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 5857} 5858 5859Action::OwningExprResult 5860Sema::CreateOverloadedArraySubscriptExpr(SourceLocation LLoc, 5861 SourceLocation RLoc, 5862 ExprArg Base, ExprArg Idx) { 5863 Expr *Args[2] = { static_cast<Expr*>(Base.get()), 5864 static_cast<Expr*>(Idx.get()) }; 5865 DeclarationName OpName = 5866 Context.DeclarationNames.getCXXOperatorName(OO_Subscript); 5867 5868 // If either side is type-dependent, create an appropriate dependent 5869 // expression. 5870 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 5871 5872 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 5873 UnresolvedLookupExpr *Fn 5874 = UnresolvedLookupExpr::Create(Context, /*Dependent*/ true, NamingClass, 5875 0, SourceRange(), OpName, LLoc, 5876 /*ADL*/ true, /*Overloaded*/ false); 5877 // Can't add any actual overloads yet 5878 5879 Base.release(); 5880 Idx.release(); 5881 return Owned(new (Context) CXXOperatorCallExpr(Context, OO_Subscript, Fn, 5882 Args, 2, 5883 Context.DependentTy, 5884 RLoc)); 5885 } 5886 5887 // Build an empty overload set. 5888 OverloadCandidateSet CandidateSet(LLoc); 5889 5890 // Subscript can only be overloaded as a member function. 5891 5892 // Add operator candidates that are member functions. 5893 AddMemberOperatorCandidates(OO_Subscript, LLoc, Args, 2, CandidateSet); 5894 5895 // Add builtin operator candidates. 5896 AddBuiltinOperatorCandidates(OO_Subscript, LLoc, Args, 2, CandidateSet); 5897 5898 // Perform overload resolution. 5899 OverloadCandidateSet::iterator Best; 5900 switch (BestViableFunction(CandidateSet, LLoc, Best)) { 5901 case OR_Success: { 5902 // We found a built-in operator or an overloaded operator. 5903 FunctionDecl *FnDecl = Best->Function; 5904 5905 if (FnDecl) { 5906 // We matched an overloaded operator. Build a call to that 5907 // operator. 5908 5909 CheckMemberOperatorAccess(LLoc, Args[0], FnDecl, Best->getAccess()); 5910 5911 // Convert the arguments. 5912 CXXMethodDecl *Method = cast<CXXMethodDecl>(FnDecl); 5913 if (PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/0, 5914 Method)) 5915 return ExprError(); 5916 5917 // Convert the arguments. 5918 OwningExprResult InputInit 5919 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 5920 FnDecl->getParamDecl(0)), 5921 SourceLocation(), 5922 Owned(Args[1])); 5923 if (InputInit.isInvalid()) 5924 return ExprError(); 5925 5926 Args[1] = InputInit.takeAs<Expr>(); 5927 5928 // Determine the result type 5929 QualType ResultTy 5930 = FnDecl->getType()->getAs<FunctionType>()->getResultType(); 5931 ResultTy = ResultTy.getNonReferenceType(); 5932 5933 // Build the actual expression node. 5934 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 5935 LLoc); 5936 UsualUnaryConversions(FnExpr); 5937 5938 Base.release(); 5939 Idx.release(); 5940 ExprOwningPtr<CXXOperatorCallExpr> 5941 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Subscript, 5942 FnExpr, Args, 2, 5943 ResultTy, RLoc)); 5944 5945 if (CheckCallReturnType(FnDecl->getResultType(), LLoc, TheCall.get(), 5946 FnDecl)) 5947 return ExprError(); 5948 5949 return MaybeBindToTemporary(TheCall.release()); 5950 } else { 5951 // We matched a built-in operator. Convert the arguments, then 5952 // break out so that we will build the appropriate built-in 5953 // operator node. 5954 if (PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 5955 Best->Conversions[0], AA_Passing) || 5956 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 5957 Best->Conversions[1], AA_Passing)) 5958 return ExprError(); 5959 5960 break; 5961 } 5962 } 5963 5964 case OR_No_Viable_Function: { 5965 if (CandidateSet.empty()) 5966 Diag(LLoc, diag::err_ovl_no_oper) 5967 << Args[0]->getType() << /*subscript*/ 0 5968 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 5969 else 5970 Diag(LLoc, diag::err_ovl_no_viable_subscript) 5971 << Args[0]->getType() 5972 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 5973 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2, 5974 "[]", LLoc); 5975 return ExprError(); 5976 } 5977 5978 case OR_Ambiguous: 5979 Diag(LLoc, diag::err_ovl_ambiguous_oper) 5980 << "[]" << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 5981 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, 2, 5982 "[]", LLoc); 5983 return ExprError(); 5984 5985 case OR_Deleted: 5986 Diag(LLoc, diag::err_ovl_deleted_oper) 5987 << Best->Function->isDeleted() << "[]" 5988 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 5989 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2, 5990 "[]", LLoc); 5991 return ExprError(); 5992 } 5993 5994 // We matched a built-in operator; build it. 5995 Base.release(); 5996 Idx.release(); 5997 return CreateBuiltinArraySubscriptExpr(Owned(Args[0]), LLoc, 5998 Owned(Args[1]), RLoc); 5999} 6000 6001/// BuildCallToMemberFunction - Build a call to a member 6002/// function. MemExpr is the expression that refers to the member 6003/// function (and includes the object parameter), Args/NumArgs are the 6004/// arguments to the function call (not including the object 6005/// parameter). The caller needs to validate that the member 6006/// expression refers to a member function or an overloaded member 6007/// function. 6008Sema::OwningExprResult 6009Sema::BuildCallToMemberFunction(Scope *S, Expr *MemExprE, 6010 SourceLocation LParenLoc, Expr **Args, 6011 unsigned NumArgs, SourceLocation *CommaLocs, 6012 SourceLocation RParenLoc) { 6013 // Dig out the member expression. This holds both the object 6014 // argument and the member function we're referring to. 6015 Expr *NakedMemExpr = MemExprE->IgnoreParens(); 6016 6017 MemberExpr *MemExpr; 6018 CXXMethodDecl *Method = 0; 6019 NestedNameSpecifier *Qualifier = 0; 6020 if (isa<MemberExpr>(NakedMemExpr)) { 6021 MemExpr = cast<MemberExpr>(NakedMemExpr); 6022 Method = cast<CXXMethodDecl>(MemExpr->getMemberDecl()); 6023 Qualifier = MemExpr->getQualifier(); 6024 } else { 6025 UnresolvedMemberExpr *UnresExpr = cast<UnresolvedMemberExpr>(NakedMemExpr); 6026 Qualifier = UnresExpr->getQualifier(); 6027 6028 QualType ObjectType = UnresExpr->getBaseType(); 6029 6030 // Add overload candidates 6031 OverloadCandidateSet CandidateSet(UnresExpr->getMemberLoc()); 6032 6033 // FIXME: avoid copy. 6034 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 6035 if (UnresExpr->hasExplicitTemplateArgs()) { 6036 UnresExpr->copyTemplateArgumentsInto(TemplateArgsBuffer); 6037 TemplateArgs = &TemplateArgsBuffer; 6038 } 6039 6040 for (UnresolvedMemberExpr::decls_iterator I = UnresExpr->decls_begin(), 6041 E = UnresExpr->decls_end(); I != E; ++I) { 6042 6043 NamedDecl *Func = *I; 6044 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(Func->getDeclContext()); 6045 if (isa<UsingShadowDecl>(Func)) 6046 Func = cast<UsingShadowDecl>(Func)->getTargetDecl(); 6047 6048 if ((Method = dyn_cast<CXXMethodDecl>(Func))) { 6049 // If explicit template arguments were provided, we can't call a 6050 // non-template member function. 6051 if (TemplateArgs) 6052 continue; 6053 6054 AddMethodCandidate(Method, I.getAccess(), ActingDC, ObjectType, 6055 Args, NumArgs, 6056 CandidateSet, /*SuppressUserConversions=*/false); 6057 } else { 6058 AddMethodTemplateCandidate(cast<FunctionTemplateDecl>(Func), 6059 I.getAccess(), ActingDC, TemplateArgs, 6060 ObjectType, Args, NumArgs, 6061 CandidateSet, 6062 /*SuppressUsedConversions=*/false); 6063 } 6064 } 6065 6066 DeclarationName DeclName = UnresExpr->getMemberName(); 6067 6068 OverloadCandidateSet::iterator Best; 6069 switch (BestViableFunction(CandidateSet, UnresExpr->getLocStart(), Best)) { 6070 case OR_Success: 6071 Method = cast<CXXMethodDecl>(Best->Function); 6072 CheckUnresolvedMemberAccess(UnresExpr, Method, Best->getAccess()); 6073 break; 6074 6075 case OR_No_Viable_Function: 6076 Diag(UnresExpr->getMemberLoc(), 6077 diag::err_ovl_no_viable_member_function_in_call) 6078 << DeclName << MemExprE->getSourceRange(); 6079 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6080 // FIXME: Leaking incoming expressions! 6081 return ExprError(); 6082 6083 case OR_Ambiguous: 6084 Diag(UnresExpr->getMemberLoc(), diag::err_ovl_ambiguous_member_call) 6085 << DeclName << MemExprE->getSourceRange(); 6086 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6087 // FIXME: Leaking incoming expressions! 6088 return ExprError(); 6089 6090 case OR_Deleted: 6091 Diag(UnresExpr->getMemberLoc(), diag::err_ovl_deleted_member_call) 6092 << Best->Function->isDeleted() 6093 << DeclName << MemExprE->getSourceRange(); 6094 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6095 // FIXME: Leaking incoming expressions! 6096 return ExprError(); 6097 } 6098 6099 MemExprE = FixOverloadedFunctionReference(MemExprE, Method); 6100 6101 // If overload resolution picked a static member, build a 6102 // non-member call based on that function. 6103 if (Method->isStatic()) { 6104 return BuildResolvedCallExpr(MemExprE, Method, LParenLoc, 6105 Args, NumArgs, RParenLoc); 6106 } 6107 6108 MemExpr = cast<MemberExpr>(MemExprE->IgnoreParens()); 6109 } 6110 6111 assert(Method && "Member call to something that isn't a method?"); 6112 ExprOwningPtr<CXXMemberCallExpr> 6113 TheCall(this, new (Context) CXXMemberCallExpr(Context, MemExprE, Args, 6114 NumArgs, 6115 Method->getResultType().getNonReferenceType(), 6116 RParenLoc)); 6117 6118 // Check for a valid return type. 6119 if (CheckCallReturnType(Method->getResultType(), MemExpr->getMemberLoc(), 6120 TheCall.get(), Method)) 6121 return ExprError(); 6122 6123 // Convert the object argument (for a non-static member function call). 6124 Expr *ObjectArg = MemExpr->getBase(); 6125 if (!Method->isStatic() && 6126 PerformObjectArgumentInitialization(ObjectArg, Qualifier, Method)) 6127 return ExprError(); 6128 MemExpr->setBase(ObjectArg); 6129 6130 // Convert the rest of the arguments 6131 const FunctionProtoType *Proto = cast<FunctionProtoType>(Method->getType()); 6132 if (ConvertArgumentsForCall(&*TheCall, MemExpr, Method, Proto, Args, NumArgs, 6133 RParenLoc)) 6134 return ExprError(); 6135 6136 if (CheckFunctionCall(Method, TheCall.get())) 6137 return ExprError(); 6138 6139 return MaybeBindToTemporary(TheCall.release()); 6140} 6141 6142/// BuildCallToObjectOfClassType - Build a call to an object of class 6143/// type (C++ [over.call.object]), which can end up invoking an 6144/// overloaded function call operator (@c operator()) or performing a 6145/// user-defined conversion on the object argument. 6146Sema::ExprResult 6147Sema::BuildCallToObjectOfClassType(Scope *S, Expr *Object, 6148 SourceLocation LParenLoc, 6149 Expr **Args, unsigned NumArgs, 6150 SourceLocation *CommaLocs, 6151 SourceLocation RParenLoc) { 6152 assert(Object->getType()->isRecordType() && "Requires object type argument"); 6153 const RecordType *Record = Object->getType()->getAs<RecordType>(); 6154 6155 // C++ [over.call.object]p1: 6156 // If the primary-expression E in the function call syntax 6157 // evaluates to a class object of type "cv T", then the set of 6158 // candidate functions includes at least the function call 6159 // operators of T. The function call operators of T are obtained by 6160 // ordinary lookup of the name operator() in the context of 6161 // (E).operator(). 6162 OverloadCandidateSet CandidateSet(LParenLoc); 6163 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Call); 6164 6165 if (RequireCompleteType(LParenLoc, Object->getType(), 6166 PartialDiagnostic(diag::err_incomplete_object_call) 6167 << Object->getSourceRange())) 6168 return true; 6169 6170 LookupResult R(*this, OpName, LParenLoc, LookupOrdinaryName); 6171 LookupQualifiedName(R, Record->getDecl()); 6172 R.suppressDiagnostics(); 6173 6174 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 6175 Oper != OperEnd; ++Oper) { 6176 AddMethodCandidate(*Oper, Oper.getAccess(), Object->getType(), 6177 Args, NumArgs, CandidateSet, 6178 /*SuppressUserConversions=*/ false); 6179 } 6180 6181 // C++ [over.call.object]p2: 6182 // In addition, for each conversion function declared in T of the 6183 // form 6184 // 6185 // operator conversion-type-id () cv-qualifier; 6186 // 6187 // where cv-qualifier is the same cv-qualification as, or a 6188 // greater cv-qualification than, cv, and where conversion-type-id 6189 // denotes the type "pointer to function of (P1,...,Pn) returning 6190 // R", or the type "reference to pointer to function of 6191 // (P1,...,Pn) returning R", or the type "reference to function 6192 // of (P1,...,Pn) returning R", a surrogate call function [...] 6193 // is also considered as a candidate function. Similarly, 6194 // surrogate call functions are added to the set of candidate 6195 // functions for each conversion function declared in an 6196 // accessible base class provided the function is not hidden 6197 // within T by another intervening declaration. 6198 const UnresolvedSetImpl *Conversions 6199 = cast<CXXRecordDecl>(Record->getDecl())->getVisibleConversionFunctions(); 6200 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 6201 E = Conversions->end(); I != E; ++I) { 6202 NamedDecl *D = *I; 6203 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext()); 6204 if (isa<UsingShadowDecl>(D)) 6205 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 6206 6207 // Skip over templated conversion functions; they aren't 6208 // surrogates. 6209 if (isa<FunctionTemplateDecl>(D)) 6210 continue; 6211 6212 CXXConversionDecl *Conv = cast<CXXConversionDecl>(D); 6213 6214 // Strip the reference type (if any) and then the pointer type (if 6215 // any) to get down to what might be a function type. 6216 QualType ConvType = Conv->getConversionType().getNonReferenceType(); 6217 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 6218 ConvType = ConvPtrType->getPointeeType(); 6219 6220 if (const FunctionProtoType *Proto = ConvType->getAs<FunctionProtoType>()) 6221 AddSurrogateCandidate(Conv, I.getAccess(), ActingContext, Proto, 6222 Object->getType(), Args, NumArgs, 6223 CandidateSet); 6224 } 6225 6226 // Perform overload resolution. 6227 OverloadCandidateSet::iterator Best; 6228 switch (BestViableFunction(CandidateSet, Object->getLocStart(), Best)) { 6229 case OR_Success: 6230 // Overload resolution succeeded; we'll build the appropriate call 6231 // below. 6232 break; 6233 6234 case OR_No_Viable_Function: 6235 if (CandidateSet.empty()) 6236 Diag(Object->getSourceRange().getBegin(), diag::err_ovl_no_oper) 6237 << Object->getType() << /*call*/ 1 6238 << Object->getSourceRange(); 6239 else 6240 Diag(Object->getSourceRange().getBegin(), 6241 diag::err_ovl_no_viable_object_call) 6242 << Object->getType() << Object->getSourceRange(); 6243 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6244 break; 6245 6246 case OR_Ambiguous: 6247 Diag(Object->getSourceRange().getBegin(), 6248 diag::err_ovl_ambiguous_object_call) 6249 << Object->getType() << Object->getSourceRange(); 6250 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, NumArgs); 6251 break; 6252 6253 case OR_Deleted: 6254 Diag(Object->getSourceRange().getBegin(), 6255 diag::err_ovl_deleted_object_call) 6256 << Best->Function->isDeleted() 6257 << Object->getType() << Object->getSourceRange(); 6258 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6259 break; 6260 } 6261 6262 if (Best == CandidateSet.end()) { 6263 // We had an error; delete all of the subexpressions and return 6264 // the error. 6265 Object->Destroy(Context); 6266 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 6267 Args[ArgIdx]->Destroy(Context); 6268 return true; 6269 } 6270 6271 if (Best->Function == 0) { 6272 // Since there is no function declaration, this is one of the 6273 // surrogate candidates. Dig out the conversion function. 6274 CXXConversionDecl *Conv 6275 = cast<CXXConversionDecl>( 6276 Best->Conversions[0].UserDefined.ConversionFunction); 6277 6278 CheckMemberOperatorAccess(LParenLoc, Object, Conv, Best->getAccess()); 6279 6280 // We selected one of the surrogate functions that converts the 6281 // object parameter to a function pointer. Perform the conversion 6282 // on the object argument, then let ActOnCallExpr finish the job. 6283 6284 // Create an implicit member expr to refer to the conversion operator. 6285 // and then call it. 6286 CXXMemberCallExpr *CE = BuildCXXMemberCallExpr(Object, Conv); 6287 6288 return ActOnCallExpr(S, ExprArg(*this, CE), LParenLoc, 6289 MultiExprArg(*this, (ExprTy**)Args, NumArgs), 6290 CommaLocs, RParenLoc).release(); 6291 } 6292 6293 CheckMemberOperatorAccess(LParenLoc, Object, 6294 Best->Function, Best->getAccess()); 6295 6296 // We found an overloaded operator(). Build a CXXOperatorCallExpr 6297 // that calls this method, using Object for the implicit object 6298 // parameter and passing along the remaining arguments. 6299 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 6300 const FunctionProtoType *Proto = Method->getType()->getAs<FunctionProtoType>(); 6301 6302 unsigned NumArgsInProto = Proto->getNumArgs(); 6303 unsigned NumArgsToCheck = NumArgs; 6304 6305 // Build the full argument list for the method call (the 6306 // implicit object parameter is placed at the beginning of the 6307 // list). 6308 Expr **MethodArgs; 6309 if (NumArgs < NumArgsInProto) { 6310 NumArgsToCheck = NumArgsInProto; 6311 MethodArgs = new Expr*[NumArgsInProto + 1]; 6312 } else { 6313 MethodArgs = new Expr*[NumArgs + 1]; 6314 } 6315 MethodArgs[0] = Object; 6316 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 6317 MethodArgs[ArgIdx + 1] = Args[ArgIdx]; 6318 6319 Expr *NewFn = new (Context) DeclRefExpr(Method, Method->getType(), 6320 SourceLocation()); 6321 UsualUnaryConversions(NewFn); 6322 6323 // Once we've built TheCall, all of the expressions are properly 6324 // owned. 6325 QualType ResultTy = Method->getResultType().getNonReferenceType(); 6326 ExprOwningPtr<CXXOperatorCallExpr> 6327 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Call, NewFn, 6328 MethodArgs, NumArgs + 1, 6329 ResultTy, RParenLoc)); 6330 delete [] MethodArgs; 6331 6332 if (CheckCallReturnType(Method->getResultType(), LParenLoc, TheCall.get(), 6333 Method)) 6334 return true; 6335 6336 // We may have default arguments. If so, we need to allocate more 6337 // slots in the call for them. 6338 if (NumArgs < NumArgsInProto) 6339 TheCall->setNumArgs(Context, NumArgsInProto + 1); 6340 else if (NumArgs > NumArgsInProto) 6341 NumArgsToCheck = NumArgsInProto; 6342 6343 bool IsError = false; 6344 6345 // Initialize the implicit object parameter. 6346 IsError |= PerformObjectArgumentInitialization(Object, /*Qualifier=*/0, 6347 Method); 6348 TheCall->setArg(0, Object); 6349 6350 6351 // Check the argument types. 6352 for (unsigned i = 0; i != NumArgsToCheck; i++) { 6353 Expr *Arg; 6354 if (i < NumArgs) { 6355 Arg = Args[i]; 6356 6357 // Pass the argument. 6358 6359 OwningExprResult InputInit 6360 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 6361 Method->getParamDecl(i)), 6362 SourceLocation(), Owned(Arg)); 6363 6364 IsError |= InputInit.isInvalid(); 6365 Arg = InputInit.takeAs<Expr>(); 6366 } else { 6367 OwningExprResult DefArg 6368 = BuildCXXDefaultArgExpr(LParenLoc, Method, Method->getParamDecl(i)); 6369 if (DefArg.isInvalid()) { 6370 IsError = true; 6371 break; 6372 } 6373 6374 Arg = DefArg.takeAs<Expr>(); 6375 } 6376 6377 TheCall->setArg(i + 1, Arg); 6378 } 6379 6380 // If this is a variadic call, handle args passed through "...". 6381 if (Proto->isVariadic()) { 6382 // Promote the arguments (C99 6.5.2.2p7). 6383 for (unsigned i = NumArgsInProto; i != NumArgs; i++) { 6384 Expr *Arg = Args[i]; 6385 IsError |= DefaultVariadicArgumentPromotion(Arg, VariadicMethod); 6386 TheCall->setArg(i + 1, Arg); 6387 } 6388 } 6389 6390 if (IsError) return true; 6391 6392 if (CheckFunctionCall(Method, TheCall.get())) 6393 return true; 6394 6395 return MaybeBindToTemporary(TheCall.release()).release(); 6396} 6397 6398/// BuildOverloadedArrowExpr - Build a call to an overloaded @c operator-> 6399/// (if one exists), where @c Base is an expression of class type and 6400/// @c Member is the name of the member we're trying to find. 6401Sema::OwningExprResult 6402Sema::BuildOverloadedArrowExpr(Scope *S, ExprArg BaseIn, SourceLocation OpLoc) { 6403 Expr *Base = static_cast<Expr *>(BaseIn.get()); 6404 assert(Base->getType()->isRecordType() && "left-hand side must have class type"); 6405 6406 SourceLocation Loc = Base->getExprLoc(); 6407 6408 // C++ [over.ref]p1: 6409 // 6410 // [...] An expression x->m is interpreted as (x.operator->())->m 6411 // for a class object x of type T if T::operator->() exists and if 6412 // the operator is selected as the best match function by the 6413 // overload resolution mechanism (13.3). 6414 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Arrow); 6415 OverloadCandidateSet CandidateSet(Loc); 6416 const RecordType *BaseRecord = Base->getType()->getAs<RecordType>(); 6417 6418 if (RequireCompleteType(Loc, Base->getType(), 6419 PDiag(diag::err_typecheck_incomplete_tag) 6420 << Base->getSourceRange())) 6421 return ExprError(); 6422 6423 LookupResult R(*this, OpName, OpLoc, LookupOrdinaryName); 6424 LookupQualifiedName(R, BaseRecord->getDecl()); 6425 R.suppressDiagnostics(); 6426 6427 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 6428 Oper != OperEnd; ++Oper) { 6429 NamedDecl *D = *Oper; 6430 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext()); 6431 if (isa<UsingShadowDecl>(D)) 6432 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 6433 6434 AddMethodCandidate(cast<CXXMethodDecl>(D), Oper.getAccess(), ActingContext, 6435 Base->getType(), 0, 0, CandidateSet, 6436 /*SuppressUserConversions=*/false); 6437 } 6438 6439 // Perform overload resolution. 6440 OverloadCandidateSet::iterator Best; 6441 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 6442 case OR_Success: 6443 // Overload resolution succeeded; we'll build the call below. 6444 break; 6445 6446 case OR_No_Viable_Function: 6447 if (CandidateSet.empty()) 6448 Diag(OpLoc, diag::err_typecheck_member_reference_arrow) 6449 << Base->getType() << Base->getSourceRange(); 6450 else 6451 Diag(OpLoc, diag::err_ovl_no_viable_oper) 6452 << "operator->" << Base->getSourceRange(); 6453 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, &Base, 1); 6454 return ExprError(); 6455 6456 case OR_Ambiguous: 6457 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 6458 << "->" << Base->getSourceRange(); 6459 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, &Base, 1); 6460 return ExprError(); 6461 6462 case OR_Deleted: 6463 Diag(OpLoc, diag::err_ovl_deleted_oper) 6464 << Best->Function->isDeleted() 6465 << "->" << Base->getSourceRange(); 6466 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, &Base, 1); 6467 return ExprError(); 6468 } 6469 6470 // Convert the object parameter. 6471 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 6472 if (PerformObjectArgumentInitialization(Base, /*Qualifier=*/0, Method)) 6473 return ExprError(); 6474 6475 // No concerns about early exits now. 6476 BaseIn.release(); 6477 6478 // Build the operator call. 6479 Expr *FnExpr = new (Context) DeclRefExpr(Method, Method->getType(), 6480 SourceLocation()); 6481 UsualUnaryConversions(FnExpr); 6482 6483 QualType ResultTy = Method->getResultType().getNonReferenceType(); 6484 ExprOwningPtr<CXXOperatorCallExpr> 6485 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Arrow, FnExpr, 6486 &Base, 1, ResultTy, OpLoc)); 6487 6488 if (CheckCallReturnType(Method->getResultType(), OpLoc, TheCall.get(), 6489 Method)) 6490 return ExprError(); 6491 return move(TheCall); 6492} 6493 6494/// FixOverloadedFunctionReference - E is an expression that refers to 6495/// a C++ overloaded function (possibly with some parentheses and 6496/// perhaps a '&' around it). We have resolved the overloaded function 6497/// to the function declaration Fn, so patch up the expression E to 6498/// refer (possibly indirectly) to Fn. Returns the new expr. 6499Expr *Sema::FixOverloadedFunctionReference(Expr *E, FunctionDecl *Fn) { 6500 if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) { 6501 Expr *SubExpr = FixOverloadedFunctionReference(PE->getSubExpr(), Fn); 6502 if (SubExpr == PE->getSubExpr()) 6503 return PE->Retain(); 6504 6505 return new (Context) ParenExpr(PE->getLParen(), PE->getRParen(), SubExpr); 6506 } 6507 6508 if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) { 6509 Expr *SubExpr = FixOverloadedFunctionReference(ICE->getSubExpr(), Fn); 6510 assert(Context.hasSameType(ICE->getSubExpr()->getType(), 6511 SubExpr->getType()) && 6512 "Implicit cast type cannot be determined from overload"); 6513 if (SubExpr == ICE->getSubExpr()) 6514 return ICE->Retain(); 6515 6516 return new (Context) ImplicitCastExpr(ICE->getType(), 6517 ICE->getCastKind(), 6518 SubExpr, 6519 ICE->isLvalueCast()); 6520 } 6521 6522 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(E)) { 6523 assert(UnOp->getOpcode() == UnaryOperator::AddrOf && 6524 "Can only take the address of an overloaded function"); 6525 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 6526 if (Method->isStatic()) { 6527 // Do nothing: static member functions aren't any different 6528 // from non-member functions. 6529 } else { 6530 // Fix the sub expression, which really has to be an 6531 // UnresolvedLookupExpr holding an overloaded member function 6532 // or template. 6533 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(), Fn); 6534 if (SubExpr == UnOp->getSubExpr()) 6535 return UnOp->Retain(); 6536 6537 assert(isa<DeclRefExpr>(SubExpr) 6538 && "fixed to something other than a decl ref"); 6539 assert(cast<DeclRefExpr>(SubExpr)->getQualifier() 6540 && "fixed to a member ref with no nested name qualifier"); 6541 6542 // We have taken the address of a pointer to member 6543 // function. Perform the computation here so that we get the 6544 // appropriate pointer to member type. 6545 QualType ClassType 6546 = Context.getTypeDeclType(cast<RecordDecl>(Method->getDeclContext())); 6547 QualType MemPtrType 6548 = Context.getMemberPointerType(Fn->getType(), ClassType.getTypePtr()); 6549 6550 return new (Context) UnaryOperator(SubExpr, UnaryOperator::AddrOf, 6551 MemPtrType, UnOp->getOperatorLoc()); 6552 } 6553 } 6554 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(), Fn); 6555 if (SubExpr == UnOp->getSubExpr()) 6556 return UnOp->Retain(); 6557 6558 return new (Context) UnaryOperator(SubExpr, UnaryOperator::AddrOf, 6559 Context.getPointerType(SubExpr->getType()), 6560 UnOp->getOperatorLoc()); 6561 } 6562 6563 if (UnresolvedLookupExpr *ULE = dyn_cast<UnresolvedLookupExpr>(E)) { 6564 // FIXME: avoid copy. 6565 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 6566 if (ULE->hasExplicitTemplateArgs()) { 6567 ULE->copyTemplateArgumentsInto(TemplateArgsBuffer); 6568 TemplateArgs = &TemplateArgsBuffer; 6569 } 6570 6571 return DeclRefExpr::Create(Context, 6572 ULE->getQualifier(), 6573 ULE->getQualifierRange(), 6574 Fn, 6575 ULE->getNameLoc(), 6576 Fn->getType(), 6577 TemplateArgs); 6578 } 6579 6580 if (UnresolvedMemberExpr *MemExpr = dyn_cast<UnresolvedMemberExpr>(E)) { 6581 // FIXME: avoid copy. 6582 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 6583 if (MemExpr->hasExplicitTemplateArgs()) { 6584 MemExpr->copyTemplateArgumentsInto(TemplateArgsBuffer); 6585 TemplateArgs = &TemplateArgsBuffer; 6586 } 6587 6588 Expr *Base; 6589 6590 // If we're filling in 6591 if (MemExpr->isImplicitAccess()) { 6592 if (cast<CXXMethodDecl>(Fn)->isStatic()) { 6593 return DeclRefExpr::Create(Context, 6594 MemExpr->getQualifier(), 6595 MemExpr->getQualifierRange(), 6596 Fn, 6597 MemExpr->getMemberLoc(), 6598 Fn->getType(), 6599 TemplateArgs); 6600 } else { 6601 SourceLocation Loc = MemExpr->getMemberLoc(); 6602 if (MemExpr->getQualifier()) 6603 Loc = MemExpr->getQualifierRange().getBegin(); 6604 Base = new (Context) CXXThisExpr(Loc, 6605 MemExpr->getBaseType(), 6606 /*isImplicit=*/true); 6607 } 6608 } else 6609 Base = MemExpr->getBase()->Retain(); 6610 6611 return MemberExpr::Create(Context, Base, 6612 MemExpr->isArrow(), 6613 MemExpr->getQualifier(), 6614 MemExpr->getQualifierRange(), 6615 Fn, 6616 MemExpr->getMemberLoc(), 6617 TemplateArgs, 6618 Fn->getType()); 6619 } 6620 6621 assert(false && "Invalid reference to overloaded function"); 6622 return E->Retain(); 6623} 6624 6625Sema::OwningExprResult Sema::FixOverloadedFunctionReference(OwningExprResult E, 6626 FunctionDecl *Fn) { 6627 return Owned(FixOverloadedFunctionReference((Expr *)E.get(), Fn)); 6628} 6629 6630} // end namespace clang 6631