SemaOverload.cpp revision f3f91f3719a95036175ad767805657cdfeb54406
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_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 Deprecated = 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()->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(); 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 OverloadCandidateSet Conversions; 451 OverloadingResult UserDefResult = OR_Success; 452 if (IsStandardConversion(From, ToType, InOverloadResolution, ICS.Standard)) 453 ICS.setStandard(); 454 else if (getLangOptions().CPlusPlus && 455 (UserDefResult = IsUserDefinedConversion(From, ToType, 456 ICS.UserDefined, 457 Conversions, 458 !SuppressUserConversions, AllowExplicit, 459 ForceRValue, UserCast)) == OR_Success) { 460 ICS.setUserDefined(); 461 // C++ [over.ics.user]p4: 462 // A conversion of an expression of class type to the same class 463 // type is given Exact Match rank, and a conversion of an 464 // expression of class type to a base class of that type is 465 // given Conversion rank, in spite of the fact that a copy 466 // constructor (i.e., a user-defined conversion function) is 467 // called for those cases. 468 if (CXXConstructorDecl *Constructor 469 = dyn_cast<CXXConstructorDecl>(ICS.UserDefined.ConversionFunction)) { 470 QualType FromCanon 471 = Context.getCanonicalType(From->getType().getUnqualifiedType()); 472 QualType ToCanon = Context.getCanonicalType(ToType).getUnqualifiedType(); 473 if (Constructor->isCopyConstructor() && 474 (FromCanon == ToCanon || IsDerivedFrom(FromCanon, ToCanon))) { 475 // Turn this into a "standard" conversion sequence, so that it 476 // gets ranked with standard conversion sequences. 477 ICS.setStandard(); 478 ICS.Standard.setAsIdentityConversion(); 479 ICS.Standard.setFromType(From->getType()); 480 ICS.Standard.setToType(ToType); 481 ICS.Standard.CopyConstructor = Constructor; 482 if (ToCanon != FromCanon) 483 ICS.Standard.Second = ICK_Derived_To_Base; 484 } 485 } 486 487 // C++ [over.best.ics]p4: 488 // However, when considering the argument of a user-defined 489 // conversion function that is a candidate by 13.3.1.3 when 490 // invoked for the copying of the temporary in the second step 491 // of a class copy-initialization, or by 13.3.1.4, 13.3.1.5, or 492 // 13.3.1.6 in all cases, only standard conversion sequences and 493 // ellipsis conversion sequences are allowed. 494 if (SuppressUserConversions && ICS.isUserDefined()) { 495 ICS.setBad(); 496 ICS.Bad.init(BadConversionSequence::suppressed_user, From, ToType); 497 } 498 } else if (UserDefResult == OR_Ambiguous && !SuppressUserConversions) { 499 ICS.setAmbiguous(); 500 ICS.Ambiguous.setFromType(From->getType()); 501 ICS.Ambiguous.setToType(ToType); 502 for (OverloadCandidateSet::iterator Cand = Conversions.begin(); 503 Cand != Conversions.end(); ++Cand) 504 if (Cand->Viable) 505 ICS.Ambiguous.addConversion(Cand->Function); 506 } else { 507 ICS.setBad(); 508 ICS.Bad.init(BadConversionSequence::no_conversion, From, ToType); 509 } 510 511 return ICS; 512} 513 514/// \brief Determine whether the conversion from FromType to ToType is a valid 515/// conversion that strips "noreturn" off the nested function type. 516static bool IsNoReturnConversion(ASTContext &Context, QualType FromType, 517 QualType ToType, QualType &ResultTy) { 518 if (Context.hasSameUnqualifiedType(FromType, ToType)) 519 return false; 520 521 // Strip the noreturn off the type we're converting from; noreturn can 522 // safely be removed. 523 FromType = Context.getNoReturnType(FromType, false); 524 if (!Context.hasSameUnqualifiedType(FromType, ToType)) 525 return false; 526 527 ResultTy = FromType; 528 return true; 529} 530 531/// IsStandardConversion - Determines whether there is a standard 532/// conversion sequence (C++ [conv], C++ [over.ics.scs]) from the 533/// expression From to the type ToType. Standard conversion sequences 534/// only consider non-class types; for conversions that involve class 535/// types, use TryImplicitConversion. If a conversion exists, SCS will 536/// contain the standard conversion sequence required to perform this 537/// conversion and this routine will return true. Otherwise, this 538/// routine will return false and the value of SCS is unspecified. 539bool 540Sema::IsStandardConversion(Expr* From, QualType ToType, 541 bool InOverloadResolution, 542 StandardConversionSequence &SCS) { 543 QualType FromType = From->getType(); 544 545 // Standard conversions (C++ [conv]) 546 SCS.setAsIdentityConversion(); 547 SCS.Deprecated = false; 548 SCS.IncompatibleObjC = false; 549 SCS.setFromType(FromType); 550 SCS.CopyConstructor = 0; 551 552 // There are no standard conversions for class types in C++, so 553 // abort early. When overloading in C, however, we do permit 554 if (FromType->isRecordType() || ToType->isRecordType()) { 555 if (getLangOptions().CPlusPlus) 556 return false; 557 558 // When we're overloading in C, we allow, as standard conversions, 559 } 560 561 // The first conversion can be an lvalue-to-rvalue conversion, 562 // array-to-pointer conversion, or function-to-pointer conversion 563 // (C++ 4p1). 564 565 // Lvalue-to-rvalue conversion (C++ 4.1): 566 // An lvalue (3.10) of a non-function, non-array type T can be 567 // converted to an rvalue. 568 Expr::isLvalueResult argIsLvalue = From->isLvalue(Context); 569 if (argIsLvalue == Expr::LV_Valid && 570 !FromType->isFunctionType() && !FromType->isArrayType() && 571 Context.getCanonicalType(FromType) != Context.OverloadTy) { 572 SCS.First = ICK_Lvalue_To_Rvalue; 573 574 // If T is a non-class type, the type of the rvalue is the 575 // cv-unqualified version of T. Otherwise, the type of the rvalue 576 // is T (C++ 4.1p1). C++ can't get here with class types; in C, we 577 // just strip the qualifiers because they don't matter. 578 FromType = FromType.getUnqualifiedType(); 579 } else if (FromType->isArrayType()) { 580 // Array-to-pointer conversion (C++ 4.2) 581 SCS.First = ICK_Array_To_Pointer; 582 583 // An lvalue or rvalue of type "array of N T" or "array of unknown 584 // bound of T" can be converted to an rvalue of type "pointer to 585 // T" (C++ 4.2p1). 586 FromType = Context.getArrayDecayedType(FromType); 587 588 if (IsStringLiteralToNonConstPointerConversion(From, ToType)) { 589 // This conversion is deprecated. (C++ D.4). 590 SCS.Deprecated = true; 591 592 // For the purpose of ranking in overload resolution 593 // (13.3.3.1.1), this conversion is considered an 594 // array-to-pointer conversion followed by a qualification 595 // conversion (4.4). (C++ 4.2p2) 596 SCS.Second = ICK_Identity; 597 SCS.Third = ICK_Qualification; 598 SCS.setToType(ToType); 599 return true; 600 } 601 } else if (FromType->isFunctionType() && argIsLvalue == Expr::LV_Valid) { 602 // Function-to-pointer conversion (C++ 4.3). 603 SCS.First = ICK_Function_To_Pointer; 604 605 // An lvalue of function type T can be converted to an rvalue of 606 // type "pointer to T." The result is a pointer to the 607 // function. (C++ 4.3p1). 608 FromType = Context.getPointerType(FromType); 609 } else if (FunctionDecl *Fn 610 = ResolveAddressOfOverloadedFunction(From, ToType, false)) { 611 // Address of overloaded function (C++ [over.over]). 612 SCS.First = ICK_Function_To_Pointer; 613 614 // We were able to resolve the address of the overloaded function, 615 // so we can convert to the type of that function. 616 FromType = Fn->getType(); 617 if (ToType->isLValueReferenceType()) 618 FromType = Context.getLValueReferenceType(FromType); 619 else if (ToType->isRValueReferenceType()) 620 FromType = Context.getRValueReferenceType(FromType); 621 else if (ToType->isMemberPointerType()) { 622 // Resolve address only succeeds if both sides are member pointers, 623 // but it doesn't have to be the same class. See DR 247. 624 // Note that this means that the type of &Derived::fn can be 625 // Ret (Base::*)(Args) if the fn overload actually found is from the 626 // base class, even if it was brought into the derived class via a 627 // using declaration. The standard isn't clear on this issue at all. 628 CXXMethodDecl *M = cast<CXXMethodDecl>(Fn); 629 FromType = Context.getMemberPointerType(FromType, 630 Context.getTypeDeclType(M->getParent()).getTypePtr()); 631 } else 632 FromType = Context.getPointerType(FromType); 633 } else { 634 // We don't require any conversions for the first step. 635 SCS.First = ICK_Identity; 636 } 637 638 // The second conversion can be an integral promotion, floating 639 // point promotion, integral conversion, floating point conversion, 640 // floating-integral conversion, pointer conversion, 641 // pointer-to-member conversion, or boolean conversion (C++ 4p1). 642 // For overloading in C, this can also be a "compatible-type" 643 // conversion. 644 bool IncompatibleObjC = false; 645 if (Context.hasSameUnqualifiedType(FromType, ToType)) { 646 // The unqualified versions of the types are the same: there's no 647 // conversion to do. 648 SCS.Second = ICK_Identity; 649 } else if (IsIntegralPromotion(From, FromType, ToType)) { 650 // Integral promotion (C++ 4.5). 651 SCS.Second = ICK_Integral_Promotion; 652 FromType = ToType.getUnqualifiedType(); 653 } else if (IsFloatingPointPromotion(FromType, ToType)) { 654 // Floating point promotion (C++ 4.6). 655 SCS.Second = ICK_Floating_Promotion; 656 FromType = ToType.getUnqualifiedType(); 657 } else if (IsComplexPromotion(FromType, ToType)) { 658 // Complex promotion (Clang extension) 659 SCS.Second = ICK_Complex_Promotion; 660 FromType = ToType.getUnqualifiedType(); 661 } else if ((FromType->isIntegralType() || FromType->isEnumeralType()) && 662 (ToType->isIntegralType() && !ToType->isEnumeralType())) { 663 // Integral conversions (C++ 4.7). 664 SCS.Second = ICK_Integral_Conversion; 665 FromType = ToType.getUnqualifiedType(); 666 } else if (FromType->isFloatingType() && ToType->isFloatingType()) { 667 // Floating point conversions (C++ 4.8). 668 SCS.Second = ICK_Floating_Conversion; 669 FromType = ToType.getUnqualifiedType(); 670 } else if (FromType->isComplexType() && ToType->isComplexType()) { 671 // Complex conversions (C99 6.3.1.6) 672 SCS.Second = ICK_Complex_Conversion; 673 FromType = ToType.getUnqualifiedType(); 674 } else if ((FromType->isFloatingType() && 675 ToType->isIntegralType() && (!ToType->isBooleanType() && 676 !ToType->isEnumeralType())) || 677 ((FromType->isIntegralType() || FromType->isEnumeralType()) && 678 ToType->isFloatingType())) { 679 // Floating-integral conversions (C++ 4.9). 680 SCS.Second = ICK_Floating_Integral; 681 FromType = ToType.getUnqualifiedType(); 682 } else if ((FromType->isComplexType() && ToType->isArithmeticType()) || 683 (ToType->isComplexType() && FromType->isArithmeticType())) { 684 // Complex-real conversions (C99 6.3.1.7) 685 SCS.Second = ICK_Complex_Real; 686 FromType = ToType.getUnqualifiedType(); 687 } else if (IsPointerConversion(From, FromType, ToType, InOverloadResolution, 688 FromType, IncompatibleObjC)) { 689 // Pointer conversions (C++ 4.10). 690 SCS.Second = ICK_Pointer_Conversion; 691 SCS.IncompatibleObjC = IncompatibleObjC; 692 } else if (IsMemberPointerConversion(From, FromType, ToType, 693 InOverloadResolution, FromType)) { 694 // Pointer to member conversions (4.11). 695 SCS.Second = ICK_Pointer_Member; 696 } else if (ToType->isBooleanType() && 697 (FromType->isArithmeticType() || 698 FromType->isEnumeralType() || 699 FromType->isAnyPointerType() || 700 FromType->isBlockPointerType() || 701 FromType->isMemberPointerType() || 702 FromType->isNullPtrType())) { 703 // Boolean conversions (C++ 4.12). 704 SCS.Second = ICK_Boolean_Conversion; 705 FromType = Context.BoolTy; 706 } else if (!getLangOptions().CPlusPlus && 707 Context.typesAreCompatible(ToType, FromType)) { 708 // Compatible conversions (Clang extension for C function overloading) 709 SCS.Second = ICK_Compatible_Conversion; 710 } else if (IsNoReturnConversion(Context, FromType, ToType, FromType)) { 711 // Treat a conversion that strips "noreturn" as an identity conversion. 712 SCS.Second = ICK_NoReturn_Adjustment; 713 } else { 714 // No second conversion required. 715 SCS.Second = ICK_Identity; 716 } 717 718 QualType CanonFrom; 719 QualType CanonTo; 720 // The third conversion can be a qualification conversion (C++ 4p1). 721 if (IsQualificationConversion(FromType, ToType)) { 722 SCS.Third = ICK_Qualification; 723 FromType = ToType; 724 CanonFrom = Context.getCanonicalType(FromType); 725 CanonTo = Context.getCanonicalType(ToType); 726 } else { 727 // No conversion required 728 SCS.Third = ICK_Identity; 729 730 // C++ [over.best.ics]p6: 731 // [...] Any difference in top-level cv-qualification is 732 // subsumed by the initialization itself and does not constitute 733 // a conversion. [...] 734 CanonFrom = Context.getCanonicalType(FromType); 735 CanonTo = Context.getCanonicalType(ToType); 736 if (CanonFrom.getLocalUnqualifiedType() 737 == CanonTo.getLocalUnqualifiedType() && 738 CanonFrom.getLocalCVRQualifiers() != CanonTo.getLocalCVRQualifiers()) { 739 FromType = ToType; 740 CanonFrom = CanonTo; 741 } 742 } 743 744 // If we have not converted the argument type to the parameter type, 745 // this is a bad conversion sequence. 746 if (CanonFrom != CanonTo) 747 return false; 748 749 SCS.setToType(FromType); 750 return true; 751} 752 753/// IsIntegralPromotion - Determines whether the conversion from the 754/// expression From (whose potentially-adjusted type is FromType) to 755/// ToType is an integral promotion (C++ 4.5). If so, returns true and 756/// sets PromotedType to the promoted type. 757bool Sema::IsIntegralPromotion(Expr *From, QualType FromType, QualType ToType) { 758 const BuiltinType *To = ToType->getAs<BuiltinType>(); 759 // All integers are built-in. 760 if (!To) { 761 return false; 762 } 763 764 // An rvalue of type char, signed char, unsigned char, short int, or 765 // unsigned short int can be converted to an rvalue of type int if 766 // int can represent all the values of the source type; otherwise, 767 // the source rvalue can be converted to an rvalue of type unsigned 768 // int (C++ 4.5p1). 769 if (FromType->isPromotableIntegerType() && !FromType->isBooleanType()) { 770 if (// We can promote any signed, promotable integer type to an int 771 (FromType->isSignedIntegerType() || 772 // We can promote any unsigned integer type whose size is 773 // less than int to an int. 774 (!FromType->isSignedIntegerType() && 775 Context.getTypeSize(FromType) < Context.getTypeSize(ToType)))) { 776 return To->getKind() == BuiltinType::Int; 777 } 778 779 return To->getKind() == BuiltinType::UInt; 780 } 781 782 // An rvalue of type wchar_t (3.9.1) or an enumeration type (7.2) 783 // can be converted to an rvalue of the first of the following types 784 // that can represent all the values of its underlying type: int, 785 // unsigned int, long, or unsigned long (C++ 4.5p2). 786 787 // We pre-calculate the promotion type for enum types. 788 if (const EnumType *FromEnumType = FromType->getAs<EnumType>()) 789 if (ToType->isIntegerType()) 790 return Context.hasSameUnqualifiedType(ToType, 791 FromEnumType->getDecl()->getPromotionType()); 792 793 if (FromType->isWideCharType() && ToType->isIntegerType()) { 794 // Determine whether the type we're converting from is signed or 795 // unsigned. 796 bool FromIsSigned; 797 uint64_t FromSize = Context.getTypeSize(FromType); 798 799 // FIXME: Is wchar_t signed or unsigned? We assume it's signed for now. 800 FromIsSigned = true; 801 802 // The types we'll try to promote to, in the appropriate 803 // order. Try each of these types. 804 QualType PromoteTypes[6] = { 805 Context.IntTy, Context.UnsignedIntTy, 806 Context.LongTy, Context.UnsignedLongTy , 807 Context.LongLongTy, Context.UnsignedLongLongTy 808 }; 809 for (int Idx = 0; Idx < 6; ++Idx) { 810 uint64_t ToSize = Context.getTypeSize(PromoteTypes[Idx]); 811 if (FromSize < ToSize || 812 (FromSize == ToSize && 813 FromIsSigned == PromoteTypes[Idx]->isSignedIntegerType())) { 814 // We found the type that we can promote to. If this is the 815 // type we wanted, we have a promotion. Otherwise, no 816 // promotion. 817 return Context.hasSameUnqualifiedType(ToType, PromoteTypes[Idx]); 818 } 819 } 820 } 821 822 // An rvalue for an integral bit-field (9.6) can be converted to an 823 // rvalue of type int if int can represent all the values of the 824 // bit-field; otherwise, it can be converted to unsigned int if 825 // unsigned int can represent all the values of the bit-field. If 826 // the bit-field is larger yet, no integral promotion applies to 827 // it. If the bit-field has an enumerated type, it is treated as any 828 // other value of that type for promotion purposes (C++ 4.5p3). 829 // FIXME: We should delay checking of bit-fields until we actually perform the 830 // conversion. 831 using llvm::APSInt; 832 if (From) 833 if (FieldDecl *MemberDecl = From->getBitField()) { 834 APSInt BitWidth; 835 if (FromType->isIntegralType() && !FromType->isEnumeralType() && 836 MemberDecl->getBitWidth()->isIntegerConstantExpr(BitWidth, Context)) { 837 APSInt ToSize(BitWidth.getBitWidth(), BitWidth.isUnsigned()); 838 ToSize = Context.getTypeSize(ToType); 839 840 // Are we promoting to an int from a bitfield that fits in an int? 841 if (BitWidth < ToSize || 842 (FromType->isSignedIntegerType() && BitWidth <= ToSize)) { 843 return To->getKind() == BuiltinType::Int; 844 } 845 846 // Are we promoting to an unsigned int from an unsigned bitfield 847 // that fits into an unsigned int? 848 if (FromType->isUnsignedIntegerType() && BitWidth <= ToSize) { 849 return To->getKind() == BuiltinType::UInt; 850 } 851 852 return false; 853 } 854 } 855 856 // An rvalue of type bool can be converted to an rvalue of type int, 857 // with false becoming zero and true becoming one (C++ 4.5p4). 858 if (FromType->isBooleanType() && To->getKind() == BuiltinType::Int) { 859 return true; 860 } 861 862 return false; 863} 864 865/// IsFloatingPointPromotion - Determines whether the conversion from 866/// FromType to ToType is a floating point promotion (C++ 4.6). If so, 867/// returns true and sets PromotedType to the promoted type. 868bool Sema::IsFloatingPointPromotion(QualType FromType, QualType ToType) { 869 /// An rvalue of type float can be converted to an rvalue of type 870 /// double. (C++ 4.6p1). 871 if (const BuiltinType *FromBuiltin = FromType->getAs<BuiltinType>()) 872 if (const BuiltinType *ToBuiltin = ToType->getAs<BuiltinType>()) { 873 if (FromBuiltin->getKind() == BuiltinType::Float && 874 ToBuiltin->getKind() == BuiltinType::Double) 875 return true; 876 877 // C99 6.3.1.5p1: 878 // When a float is promoted to double or long double, or a 879 // double is promoted to long double [...]. 880 if (!getLangOptions().CPlusPlus && 881 (FromBuiltin->getKind() == BuiltinType::Float || 882 FromBuiltin->getKind() == BuiltinType::Double) && 883 (ToBuiltin->getKind() == BuiltinType::LongDouble)) 884 return true; 885 } 886 887 return false; 888} 889 890/// \brief Determine if a conversion is a complex promotion. 891/// 892/// A complex promotion is defined as a complex -> complex conversion 893/// where the conversion between the underlying real types is a 894/// floating-point or integral promotion. 895bool Sema::IsComplexPromotion(QualType FromType, QualType ToType) { 896 const ComplexType *FromComplex = FromType->getAs<ComplexType>(); 897 if (!FromComplex) 898 return false; 899 900 const ComplexType *ToComplex = ToType->getAs<ComplexType>(); 901 if (!ToComplex) 902 return false; 903 904 return IsFloatingPointPromotion(FromComplex->getElementType(), 905 ToComplex->getElementType()) || 906 IsIntegralPromotion(0, FromComplex->getElementType(), 907 ToComplex->getElementType()); 908} 909 910/// BuildSimilarlyQualifiedPointerType - In a pointer conversion from 911/// the pointer type FromPtr to a pointer to type ToPointee, with the 912/// same type qualifiers as FromPtr has on its pointee type. ToType, 913/// if non-empty, will be a pointer to ToType that may or may not have 914/// the right set of qualifiers on its pointee. 915static QualType 916BuildSimilarlyQualifiedPointerType(const PointerType *FromPtr, 917 QualType ToPointee, QualType ToType, 918 ASTContext &Context) { 919 QualType CanonFromPointee = Context.getCanonicalType(FromPtr->getPointeeType()); 920 QualType CanonToPointee = Context.getCanonicalType(ToPointee); 921 Qualifiers Quals = CanonFromPointee.getQualifiers(); 922 923 // Exact qualifier match -> return the pointer type we're converting to. 924 if (CanonToPointee.getLocalQualifiers() == Quals) { 925 // ToType is exactly what we need. Return it. 926 if (!ToType.isNull()) 927 return ToType; 928 929 // Build a pointer to ToPointee. It has the right qualifiers 930 // already. 931 return Context.getPointerType(ToPointee); 932 } 933 934 // Just build a canonical type that has the right qualifiers. 935 return Context.getPointerType( 936 Context.getQualifiedType(CanonToPointee.getLocalUnqualifiedType(), 937 Quals)); 938} 939 940/// BuildSimilarlyQualifiedObjCObjectPointerType - In a pointer conversion from 941/// the FromType, which is an objective-c pointer, to ToType, which may or may 942/// not have the right set of qualifiers. 943static QualType 944BuildSimilarlyQualifiedObjCObjectPointerType(QualType FromType, 945 QualType ToType, 946 ASTContext &Context) { 947 QualType CanonFromType = Context.getCanonicalType(FromType); 948 QualType CanonToType = Context.getCanonicalType(ToType); 949 Qualifiers Quals = CanonFromType.getQualifiers(); 950 951 // Exact qualifier match -> return the pointer type we're converting to. 952 if (CanonToType.getLocalQualifiers() == Quals) 953 return ToType; 954 955 // Just build a canonical type that has the right qualifiers. 956 return Context.getQualifiedType(CanonToType.getLocalUnqualifiedType(), Quals); 957} 958 959static bool isNullPointerConstantForConversion(Expr *Expr, 960 bool InOverloadResolution, 961 ASTContext &Context) { 962 // Handle value-dependent integral null pointer constants correctly. 963 // http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#903 964 if (Expr->isValueDependent() && !Expr->isTypeDependent() && 965 Expr->getType()->isIntegralType()) 966 return !InOverloadResolution; 967 968 return Expr->isNullPointerConstant(Context, 969 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull 970 : Expr::NPC_ValueDependentIsNull); 971} 972 973/// IsPointerConversion - Determines whether the conversion of the 974/// expression From, which has the (possibly adjusted) type FromType, 975/// can be converted to the type ToType via a pointer conversion (C++ 976/// 4.10). If so, returns true and places the converted type (that 977/// might differ from ToType in its cv-qualifiers at some level) into 978/// ConvertedType. 979/// 980/// This routine also supports conversions to and from block pointers 981/// and conversions with Objective-C's 'id', 'id<protocols...>', and 982/// pointers to interfaces. FIXME: Once we've determined the 983/// appropriate overloading rules for Objective-C, we may want to 984/// split the Objective-C checks into a different routine; however, 985/// GCC seems to consider all of these conversions to be pointer 986/// conversions, so for now they live here. IncompatibleObjC will be 987/// set if the conversion is an allowed Objective-C conversion that 988/// should result in a warning. 989bool Sema::IsPointerConversion(Expr *From, QualType FromType, QualType ToType, 990 bool InOverloadResolution, 991 QualType& ConvertedType, 992 bool &IncompatibleObjC) { 993 IncompatibleObjC = false; 994 if (isObjCPointerConversion(FromType, ToType, ConvertedType, IncompatibleObjC)) 995 return true; 996 997 // Conversion from a null pointer constant to any Objective-C pointer type. 998 if (ToType->isObjCObjectPointerType() && 999 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1000 ConvertedType = ToType; 1001 return true; 1002 } 1003 1004 // Blocks: Block pointers can be converted to void*. 1005 if (FromType->isBlockPointerType() && ToType->isPointerType() && 1006 ToType->getAs<PointerType>()->getPointeeType()->isVoidType()) { 1007 ConvertedType = ToType; 1008 return true; 1009 } 1010 // Blocks: A null pointer constant can be converted to a block 1011 // pointer type. 1012 if (ToType->isBlockPointerType() && 1013 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1014 ConvertedType = ToType; 1015 return true; 1016 } 1017 1018 // If the left-hand-side is nullptr_t, the right side can be a null 1019 // pointer constant. 1020 if (ToType->isNullPtrType() && 1021 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1022 ConvertedType = ToType; 1023 return true; 1024 } 1025 1026 const PointerType* ToTypePtr = ToType->getAs<PointerType>(); 1027 if (!ToTypePtr) 1028 return false; 1029 1030 // A null pointer constant can be converted to a pointer type (C++ 4.10p1). 1031 if (isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1032 ConvertedType = ToType; 1033 return true; 1034 } 1035 1036 // Beyond this point, both types need to be pointers 1037 // , including objective-c pointers. 1038 QualType ToPointeeType = ToTypePtr->getPointeeType(); 1039 if (FromType->isObjCObjectPointerType() && ToPointeeType->isVoidType()) { 1040 ConvertedType = BuildSimilarlyQualifiedObjCObjectPointerType(FromType, 1041 ToType, Context); 1042 return true; 1043 1044 } 1045 const PointerType *FromTypePtr = FromType->getAs<PointerType>(); 1046 if (!FromTypePtr) 1047 return false; 1048 1049 QualType FromPointeeType = FromTypePtr->getPointeeType(); 1050 1051 // An rvalue of type "pointer to cv T," where T is an object type, 1052 // can be converted to an rvalue of type "pointer to cv void" (C++ 1053 // 4.10p2). 1054 if (FromPointeeType->isObjectType() && ToPointeeType->isVoidType()) { 1055 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1056 ToPointeeType, 1057 ToType, Context); 1058 return true; 1059 } 1060 1061 // When we're overloading in C, we allow a special kind of pointer 1062 // conversion for compatible-but-not-identical pointee types. 1063 if (!getLangOptions().CPlusPlus && 1064 Context.typesAreCompatible(FromPointeeType, ToPointeeType)) { 1065 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1066 ToPointeeType, 1067 ToType, Context); 1068 return true; 1069 } 1070 1071 // C++ [conv.ptr]p3: 1072 // 1073 // An rvalue of type "pointer to cv D," where D is a class type, 1074 // can be converted to an rvalue of type "pointer to cv B," where 1075 // B is a base class (clause 10) of D. If B is an inaccessible 1076 // (clause 11) or ambiguous (10.2) base class of D, a program that 1077 // necessitates this conversion is ill-formed. The result of the 1078 // conversion is a pointer to the base class sub-object of the 1079 // derived class object. The null pointer value is converted to 1080 // the null pointer value of the destination type. 1081 // 1082 // Note that we do not check for ambiguity or inaccessibility 1083 // here. That is handled by CheckPointerConversion. 1084 if (getLangOptions().CPlusPlus && 1085 FromPointeeType->isRecordType() && ToPointeeType->isRecordType() && 1086 !RequireCompleteType(From->getLocStart(), FromPointeeType, PDiag()) && 1087 IsDerivedFrom(FromPointeeType, ToPointeeType)) { 1088 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1089 ToPointeeType, 1090 ToType, Context); 1091 return true; 1092 } 1093 1094 return false; 1095} 1096 1097/// isObjCPointerConversion - Determines whether this is an 1098/// Objective-C pointer conversion. Subroutine of IsPointerConversion, 1099/// with the same arguments and return values. 1100bool Sema::isObjCPointerConversion(QualType FromType, QualType ToType, 1101 QualType& ConvertedType, 1102 bool &IncompatibleObjC) { 1103 if (!getLangOptions().ObjC1) 1104 return false; 1105 1106 // First, we handle all conversions on ObjC object pointer types. 1107 const ObjCObjectPointerType* ToObjCPtr = ToType->getAs<ObjCObjectPointerType>(); 1108 const ObjCObjectPointerType *FromObjCPtr = 1109 FromType->getAs<ObjCObjectPointerType>(); 1110 1111 if (ToObjCPtr && FromObjCPtr) { 1112 // Objective C++: We're able to convert between "id" or "Class" and a 1113 // pointer to any interface (in both directions). 1114 if (ToObjCPtr->isObjCBuiltinType() && FromObjCPtr->isObjCBuiltinType()) { 1115 ConvertedType = ToType; 1116 return true; 1117 } 1118 // Conversions with Objective-C's id<...>. 1119 if ((FromObjCPtr->isObjCQualifiedIdType() || 1120 ToObjCPtr->isObjCQualifiedIdType()) && 1121 Context.ObjCQualifiedIdTypesAreCompatible(ToType, FromType, 1122 /*compare=*/false)) { 1123 ConvertedType = ToType; 1124 return true; 1125 } 1126 // Objective C++: We're able to convert from a pointer to an 1127 // interface to a pointer to a different interface. 1128 if (Context.canAssignObjCInterfaces(ToObjCPtr, FromObjCPtr)) { 1129 ConvertedType = ToType; 1130 return true; 1131 } 1132 1133 if (Context.canAssignObjCInterfaces(FromObjCPtr, ToObjCPtr)) { 1134 // Okay: this is some kind of implicit downcast of Objective-C 1135 // interfaces, which is permitted. However, we're going to 1136 // complain about it. 1137 IncompatibleObjC = true; 1138 ConvertedType = FromType; 1139 return true; 1140 } 1141 } 1142 // Beyond this point, both types need to be C pointers or block pointers. 1143 QualType ToPointeeType; 1144 if (const PointerType *ToCPtr = ToType->getAs<PointerType>()) 1145 ToPointeeType = ToCPtr->getPointeeType(); 1146 else if (const BlockPointerType *ToBlockPtr = 1147 ToType->getAs<BlockPointerType>()) { 1148 // Objective C++: We're able to convert from a pointer to any object 1149 // to a block pointer type. 1150 if (FromObjCPtr && FromObjCPtr->isObjCBuiltinType()) { 1151 ConvertedType = ToType; 1152 return true; 1153 } 1154 ToPointeeType = ToBlockPtr->getPointeeType(); 1155 } 1156 else if (FromType->getAs<BlockPointerType>() && 1157 ToObjCPtr && ToObjCPtr->isObjCBuiltinType()) { 1158 // Objective C++: We're able to convert from a block pointer type to a 1159 // pointer to any object. 1160 ConvertedType = ToType; 1161 return true; 1162 } 1163 else 1164 return false; 1165 1166 QualType FromPointeeType; 1167 if (const PointerType *FromCPtr = FromType->getAs<PointerType>()) 1168 FromPointeeType = FromCPtr->getPointeeType(); 1169 else if (const BlockPointerType *FromBlockPtr = FromType->getAs<BlockPointerType>()) 1170 FromPointeeType = FromBlockPtr->getPointeeType(); 1171 else 1172 return false; 1173 1174 // If we have pointers to pointers, recursively check whether this 1175 // is an Objective-C conversion. 1176 if (FromPointeeType->isPointerType() && ToPointeeType->isPointerType() && 1177 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, 1178 IncompatibleObjC)) { 1179 // We always complain about this conversion. 1180 IncompatibleObjC = true; 1181 ConvertedType = ToType; 1182 return true; 1183 } 1184 // Allow conversion of pointee being objective-c pointer to another one; 1185 // as in I* to id. 1186 if (FromPointeeType->getAs<ObjCObjectPointerType>() && 1187 ToPointeeType->getAs<ObjCObjectPointerType>() && 1188 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, 1189 IncompatibleObjC)) { 1190 ConvertedType = ToType; 1191 return true; 1192 } 1193 1194 // If we have pointers to functions or blocks, check whether the only 1195 // differences in the argument and result types are in Objective-C 1196 // pointer conversions. If so, we permit the conversion (but 1197 // complain about it). 1198 const FunctionProtoType *FromFunctionType 1199 = FromPointeeType->getAs<FunctionProtoType>(); 1200 const FunctionProtoType *ToFunctionType 1201 = ToPointeeType->getAs<FunctionProtoType>(); 1202 if (FromFunctionType && ToFunctionType) { 1203 // If the function types are exactly the same, this isn't an 1204 // Objective-C pointer conversion. 1205 if (Context.getCanonicalType(FromPointeeType) 1206 == Context.getCanonicalType(ToPointeeType)) 1207 return false; 1208 1209 // Perform the quick checks that will tell us whether these 1210 // function types are obviously different. 1211 if (FromFunctionType->getNumArgs() != ToFunctionType->getNumArgs() || 1212 FromFunctionType->isVariadic() != ToFunctionType->isVariadic() || 1213 FromFunctionType->getTypeQuals() != ToFunctionType->getTypeQuals()) 1214 return false; 1215 1216 bool HasObjCConversion = false; 1217 if (Context.getCanonicalType(FromFunctionType->getResultType()) 1218 == Context.getCanonicalType(ToFunctionType->getResultType())) { 1219 // Okay, the types match exactly. Nothing to do. 1220 } else if (isObjCPointerConversion(FromFunctionType->getResultType(), 1221 ToFunctionType->getResultType(), 1222 ConvertedType, IncompatibleObjC)) { 1223 // Okay, we have an Objective-C pointer conversion. 1224 HasObjCConversion = true; 1225 } else { 1226 // Function types are too different. Abort. 1227 return false; 1228 } 1229 1230 // Check argument types. 1231 for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumArgs(); 1232 ArgIdx != NumArgs; ++ArgIdx) { 1233 QualType FromArgType = FromFunctionType->getArgType(ArgIdx); 1234 QualType ToArgType = ToFunctionType->getArgType(ArgIdx); 1235 if (Context.getCanonicalType(FromArgType) 1236 == Context.getCanonicalType(ToArgType)) { 1237 // Okay, the types match exactly. Nothing to do. 1238 } else if (isObjCPointerConversion(FromArgType, ToArgType, 1239 ConvertedType, IncompatibleObjC)) { 1240 // Okay, we have an Objective-C pointer conversion. 1241 HasObjCConversion = true; 1242 } else { 1243 // Argument types are too different. Abort. 1244 return false; 1245 } 1246 } 1247 1248 if (HasObjCConversion) { 1249 // We had an Objective-C conversion. Allow this pointer 1250 // conversion, but complain about it. 1251 ConvertedType = ToType; 1252 IncompatibleObjC = true; 1253 return true; 1254 } 1255 } 1256 1257 return false; 1258} 1259 1260/// CheckPointerConversion - Check the pointer conversion from the 1261/// expression From to the type ToType. This routine checks for 1262/// ambiguous or inaccessible derived-to-base pointer 1263/// conversions for which IsPointerConversion has already returned 1264/// true. It returns true and produces a diagnostic if there was an 1265/// error, or returns false otherwise. 1266bool Sema::CheckPointerConversion(Expr *From, QualType ToType, 1267 CastExpr::CastKind &Kind, 1268 bool IgnoreBaseAccess) { 1269 QualType FromType = From->getType(); 1270 1271 if (const PointerType *FromPtrType = FromType->getAs<PointerType>()) 1272 if (const PointerType *ToPtrType = ToType->getAs<PointerType>()) { 1273 QualType FromPointeeType = FromPtrType->getPointeeType(), 1274 ToPointeeType = ToPtrType->getPointeeType(); 1275 1276 if (FromPointeeType->isRecordType() && 1277 ToPointeeType->isRecordType()) { 1278 // We must have a derived-to-base conversion. Check an 1279 // ambiguous or inaccessible conversion. 1280 if (CheckDerivedToBaseConversion(FromPointeeType, ToPointeeType, 1281 From->getExprLoc(), 1282 From->getSourceRange(), 1283 IgnoreBaseAccess)) 1284 return true; 1285 1286 // The conversion was successful. 1287 Kind = CastExpr::CK_DerivedToBase; 1288 } 1289 } 1290 if (const ObjCObjectPointerType *FromPtrType = 1291 FromType->getAs<ObjCObjectPointerType>()) 1292 if (const ObjCObjectPointerType *ToPtrType = 1293 ToType->getAs<ObjCObjectPointerType>()) { 1294 // Objective-C++ conversions are always okay. 1295 // FIXME: We should have a different class of conversions for the 1296 // Objective-C++ implicit conversions. 1297 if (FromPtrType->isObjCBuiltinType() || ToPtrType->isObjCBuiltinType()) 1298 return false; 1299 1300 } 1301 return false; 1302} 1303 1304/// IsMemberPointerConversion - Determines whether the conversion of the 1305/// expression From, which has the (possibly adjusted) type FromType, can be 1306/// converted to the type ToType via a member pointer conversion (C++ 4.11). 1307/// If so, returns true and places the converted type (that might differ from 1308/// ToType in its cv-qualifiers at some level) into ConvertedType. 1309bool Sema::IsMemberPointerConversion(Expr *From, QualType FromType, 1310 QualType ToType, 1311 bool InOverloadResolution, 1312 QualType &ConvertedType) { 1313 const MemberPointerType *ToTypePtr = ToType->getAs<MemberPointerType>(); 1314 if (!ToTypePtr) 1315 return false; 1316 1317 // A null pointer constant can be converted to a member pointer (C++ 4.11p1) 1318 if (From->isNullPointerConstant(Context, 1319 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull 1320 : Expr::NPC_ValueDependentIsNull)) { 1321 ConvertedType = ToType; 1322 return true; 1323 } 1324 1325 // Otherwise, both types have to be member pointers. 1326 const MemberPointerType *FromTypePtr = FromType->getAs<MemberPointerType>(); 1327 if (!FromTypePtr) 1328 return false; 1329 1330 // A pointer to member of B can be converted to a pointer to member of D, 1331 // where D is derived from B (C++ 4.11p2). 1332 QualType FromClass(FromTypePtr->getClass(), 0); 1333 QualType ToClass(ToTypePtr->getClass(), 0); 1334 // FIXME: What happens when these are dependent? Is this function even called? 1335 1336 if (IsDerivedFrom(ToClass, FromClass)) { 1337 ConvertedType = Context.getMemberPointerType(FromTypePtr->getPointeeType(), 1338 ToClass.getTypePtr()); 1339 return true; 1340 } 1341 1342 return false; 1343} 1344 1345/// CheckMemberPointerConversion - Check the member pointer conversion from the 1346/// expression From to the type ToType. This routine checks for ambiguous or 1347/// virtual (FIXME: or inaccessible) base-to-derived member pointer conversions 1348/// for which IsMemberPointerConversion has already returned true. It returns 1349/// true and produces a diagnostic if there was an error, or returns false 1350/// otherwise. 1351bool Sema::CheckMemberPointerConversion(Expr *From, QualType ToType, 1352 CastExpr::CastKind &Kind, 1353 bool IgnoreBaseAccess) { 1354 (void)IgnoreBaseAccess; 1355 QualType FromType = From->getType(); 1356 const MemberPointerType *FromPtrType = FromType->getAs<MemberPointerType>(); 1357 if (!FromPtrType) { 1358 // This must be a null pointer to member pointer conversion 1359 assert(From->isNullPointerConstant(Context, 1360 Expr::NPC_ValueDependentIsNull) && 1361 "Expr must be null pointer constant!"); 1362 Kind = CastExpr::CK_NullToMemberPointer; 1363 return false; 1364 } 1365 1366 const MemberPointerType *ToPtrType = ToType->getAs<MemberPointerType>(); 1367 assert(ToPtrType && "No member pointer cast has a target type " 1368 "that is not a member pointer."); 1369 1370 QualType FromClass = QualType(FromPtrType->getClass(), 0); 1371 QualType ToClass = QualType(ToPtrType->getClass(), 0); 1372 1373 // FIXME: What about dependent types? 1374 assert(FromClass->isRecordType() && "Pointer into non-class."); 1375 assert(ToClass->isRecordType() && "Pointer into non-class."); 1376 1377 CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/false, 1378 /*DetectVirtual=*/true); 1379 bool DerivationOkay = IsDerivedFrom(ToClass, FromClass, Paths); 1380 assert(DerivationOkay && 1381 "Should not have been called if derivation isn't OK."); 1382 (void)DerivationOkay; 1383 1384 if (Paths.isAmbiguous(Context.getCanonicalType(FromClass). 1385 getUnqualifiedType())) { 1386 // Derivation is ambiguous. Redo the check to find the exact paths. 1387 Paths.clear(); 1388 Paths.setRecordingPaths(true); 1389 bool StillOkay = IsDerivedFrom(ToClass, FromClass, Paths); 1390 assert(StillOkay && "Derivation changed due to quantum fluctuation."); 1391 (void)StillOkay; 1392 1393 std::string PathDisplayStr = getAmbiguousPathsDisplayString(Paths); 1394 Diag(From->getExprLoc(), diag::err_ambiguous_memptr_conv) 1395 << 0 << FromClass << ToClass << PathDisplayStr << From->getSourceRange(); 1396 return true; 1397 } 1398 1399 if (const RecordType *VBase = Paths.getDetectedVirtual()) { 1400 Diag(From->getExprLoc(), diag::err_memptr_conv_via_virtual) 1401 << FromClass << ToClass << QualType(VBase, 0) 1402 << From->getSourceRange(); 1403 return true; 1404 } 1405 1406 // Must be a base to derived member conversion. 1407 Kind = CastExpr::CK_BaseToDerivedMemberPointer; 1408 return false; 1409} 1410 1411/// IsQualificationConversion - Determines whether the conversion from 1412/// an rvalue of type FromType to ToType is a qualification conversion 1413/// (C++ 4.4). 1414bool 1415Sema::IsQualificationConversion(QualType FromType, QualType ToType) { 1416 FromType = Context.getCanonicalType(FromType); 1417 ToType = Context.getCanonicalType(ToType); 1418 1419 // If FromType and ToType are the same type, this is not a 1420 // qualification conversion. 1421 if (FromType == ToType) 1422 return false; 1423 1424 // (C++ 4.4p4): 1425 // A conversion can add cv-qualifiers at levels other than the first 1426 // in multi-level pointers, subject to the following rules: [...] 1427 bool PreviousToQualsIncludeConst = true; 1428 bool UnwrappedAnyPointer = false; 1429 while (UnwrapSimilarPointerTypes(FromType, ToType)) { 1430 // Within each iteration of the loop, we check the qualifiers to 1431 // determine if this still looks like a qualification 1432 // conversion. Then, if all is well, we unwrap one more level of 1433 // pointers or pointers-to-members and do it all again 1434 // until there are no more pointers or pointers-to-members left to 1435 // unwrap. 1436 UnwrappedAnyPointer = true; 1437 1438 // -- for every j > 0, if const is in cv 1,j then const is in cv 1439 // 2,j, and similarly for volatile. 1440 if (!ToType.isAtLeastAsQualifiedAs(FromType)) 1441 return false; 1442 1443 // -- if the cv 1,j and cv 2,j are different, then const is in 1444 // every cv for 0 < k < j. 1445 if (FromType.getCVRQualifiers() != ToType.getCVRQualifiers() 1446 && !PreviousToQualsIncludeConst) 1447 return false; 1448 1449 // Keep track of whether all prior cv-qualifiers in the "to" type 1450 // include const. 1451 PreviousToQualsIncludeConst 1452 = PreviousToQualsIncludeConst && ToType.isConstQualified(); 1453 } 1454 1455 // We are left with FromType and ToType being the pointee types 1456 // after unwrapping the original FromType and ToType the same number 1457 // of types. If we unwrapped any pointers, and if FromType and 1458 // ToType have the same unqualified type (since we checked 1459 // qualifiers above), then this is a qualification conversion. 1460 return UnwrappedAnyPointer && Context.hasSameUnqualifiedType(FromType,ToType); 1461} 1462 1463/// Determines whether there is a user-defined conversion sequence 1464/// (C++ [over.ics.user]) that converts expression From to the type 1465/// ToType. If such a conversion exists, User will contain the 1466/// user-defined conversion sequence that performs such a conversion 1467/// and this routine will return true. Otherwise, this routine returns 1468/// false and User is unspecified. 1469/// 1470/// \param AllowConversionFunctions true if the conversion should 1471/// consider conversion functions at all. If false, only constructors 1472/// will be considered. 1473/// 1474/// \param AllowExplicit true if the conversion should consider C++0x 1475/// "explicit" conversion functions as well as non-explicit conversion 1476/// functions (C++0x [class.conv.fct]p2). 1477/// 1478/// \param ForceRValue true if the expression should be treated as an rvalue 1479/// for overload resolution. 1480/// \param UserCast true if looking for user defined conversion for a static 1481/// cast. 1482OverloadingResult Sema::IsUserDefinedConversion(Expr *From, QualType ToType, 1483 UserDefinedConversionSequence& User, 1484 OverloadCandidateSet& CandidateSet, 1485 bool AllowConversionFunctions, 1486 bool AllowExplicit, 1487 bool ForceRValue, 1488 bool UserCast) { 1489 if (const RecordType *ToRecordType = ToType->getAs<RecordType>()) { 1490 if (RequireCompleteType(From->getLocStart(), ToType, PDiag())) { 1491 // We're not going to find any constructors. 1492 } else if (CXXRecordDecl *ToRecordDecl 1493 = dyn_cast<CXXRecordDecl>(ToRecordType->getDecl())) { 1494 // C++ [over.match.ctor]p1: 1495 // When objects of class type are direct-initialized (8.5), or 1496 // copy-initialized from an expression of the same or a 1497 // derived class type (8.5), overload resolution selects the 1498 // constructor. [...] For copy-initialization, the candidate 1499 // functions are all the converting constructors (12.3.1) of 1500 // that class. The argument list is the expression-list within 1501 // the parentheses of the initializer. 1502 bool SuppressUserConversions = !UserCast; 1503 if (Context.hasSameUnqualifiedType(ToType, From->getType()) || 1504 IsDerivedFrom(From->getType(), ToType)) { 1505 SuppressUserConversions = false; 1506 AllowConversionFunctions = false; 1507 } 1508 1509 DeclarationName ConstructorName 1510 = Context.DeclarationNames.getCXXConstructorName( 1511 Context.getCanonicalType(ToType).getUnqualifiedType()); 1512 DeclContext::lookup_iterator Con, ConEnd; 1513 for (llvm::tie(Con, ConEnd) 1514 = ToRecordDecl->lookup(ConstructorName); 1515 Con != ConEnd; ++Con) { 1516 // Find the constructor (which may be a template). 1517 CXXConstructorDecl *Constructor = 0; 1518 FunctionTemplateDecl *ConstructorTmpl 1519 = dyn_cast<FunctionTemplateDecl>(*Con); 1520 if (ConstructorTmpl) 1521 Constructor 1522 = cast<CXXConstructorDecl>(ConstructorTmpl->getTemplatedDecl()); 1523 else 1524 Constructor = cast<CXXConstructorDecl>(*Con); 1525 1526 if (!Constructor->isInvalidDecl() && 1527 Constructor->isConvertingConstructor(AllowExplicit)) { 1528 if (ConstructorTmpl) 1529 AddTemplateOverloadCandidate(ConstructorTmpl, /*ExplicitArgs*/ 0, 1530 &From, 1, CandidateSet, 1531 SuppressUserConversions, ForceRValue); 1532 else 1533 // Allow one user-defined conversion when user specifies a 1534 // From->ToType conversion via an static cast (c-style, etc). 1535 AddOverloadCandidate(Constructor, &From, 1, CandidateSet, 1536 SuppressUserConversions, ForceRValue); 1537 } 1538 } 1539 } 1540 } 1541 1542 if (!AllowConversionFunctions) { 1543 // Don't allow any conversion functions to enter the overload set. 1544 } else if (RequireCompleteType(From->getLocStart(), From->getType(), 1545 PDiag(0) 1546 << From->getSourceRange())) { 1547 // No conversion functions from incomplete types. 1548 } else if (const RecordType *FromRecordType 1549 = From->getType()->getAs<RecordType>()) { 1550 if (CXXRecordDecl *FromRecordDecl 1551 = dyn_cast<CXXRecordDecl>(FromRecordType->getDecl())) { 1552 // Add all of the conversion functions as candidates. 1553 const UnresolvedSetImpl *Conversions 1554 = FromRecordDecl->getVisibleConversionFunctions(); 1555 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 1556 E = Conversions->end(); I != E; ++I) { 1557 NamedDecl *D = *I; 1558 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext()); 1559 if (isa<UsingShadowDecl>(D)) 1560 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 1561 1562 CXXConversionDecl *Conv; 1563 FunctionTemplateDecl *ConvTemplate; 1564 if ((ConvTemplate = dyn_cast<FunctionTemplateDecl>(*I))) 1565 Conv = dyn_cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 1566 else 1567 Conv = dyn_cast<CXXConversionDecl>(*I); 1568 1569 if (AllowExplicit || !Conv->isExplicit()) { 1570 if (ConvTemplate) 1571 AddTemplateConversionCandidate(ConvTemplate, ActingContext, 1572 From, ToType, CandidateSet); 1573 else 1574 AddConversionCandidate(Conv, ActingContext, From, ToType, 1575 CandidateSet); 1576 } 1577 } 1578 } 1579 } 1580 1581 OverloadCandidateSet::iterator Best; 1582 switch (BestViableFunction(CandidateSet, From->getLocStart(), Best)) { 1583 case OR_Success: 1584 // Record the standard conversion we used and the conversion function. 1585 if (CXXConstructorDecl *Constructor 1586 = dyn_cast<CXXConstructorDecl>(Best->Function)) { 1587 // C++ [over.ics.user]p1: 1588 // If the user-defined conversion is specified by a 1589 // constructor (12.3.1), the initial standard conversion 1590 // sequence converts the source type to the type required by 1591 // the argument of the constructor. 1592 // 1593 QualType ThisType = Constructor->getThisType(Context); 1594 if (Best->Conversions[0].isEllipsis()) 1595 User.EllipsisConversion = true; 1596 else { 1597 User.Before = Best->Conversions[0].Standard; 1598 User.EllipsisConversion = false; 1599 } 1600 User.ConversionFunction = Constructor; 1601 User.After.setAsIdentityConversion(); 1602 User.After.setFromType( 1603 ThisType->getAs<PointerType>()->getPointeeType()); 1604 User.After.setToType(ToType); 1605 return OR_Success; 1606 } else if (CXXConversionDecl *Conversion 1607 = dyn_cast<CXXConversionDecl>(Best->Function)) { 1608 // C++ [over.ics.user]p1: 1609 // 1610 // [...] If the user-defined conversion is specified by a 1611 // conversion function (12.3.2), the initial standard 1612 // conversion sequence converts the source type to the 1613 // implicit object parameter of the conversion function. 1614 User.Before = Best->Conversions[0].Standard; 1615 User.ConversionFunction = Conversion; 1616 User.EllipsisConversion = false; 1617 1618 // C++ [over.ics.user]p2: 1619 // The second standard conversion sequence converts the 1620 // result of the user-defined conversion to the target type 1621 // for the sequence. Since an implicit conversion sequence 1622 // is an initialization, the special rules for 1623 // initialization by user-defined conversion apply when 1624 // selecting the best user-defined conversion for a 1625 // user-defined conversion sequence (see 13.3.3 and 1626 // 13.3.3.1). 1627 User.After = Best->FinalConversion; 1628 return OR_Success; 1629 } else { 1630 assert(false && "Not a constructor or conversion function?"); 1631 return OR_No_Viable_Function; 1632 } 1633 1634 case OR_No_Viable_Function: 1635 return OR_No_Viable_Function; 1636 case OR_Deleted: 1637 // No conversion here! We're done. 1638 return OR_Deleted; 1639 1640 case OR_Ambiguous: 1641 return OR_Ambiguous; 1642 } 1643 1644 return OR_No_Viable_Function; 1645} 1646 1647bool 1648Sema::DiagnoseMultipleUserDefinedConversion(Expr *From, QualType ToType) { 1649 ImplicitConversionSequence ICS; 1650 OverloadCandidateSet CandidateSet; 1651 OverloadingResult OvResult = 1652 IsUserDefinedConversion(From, ToType, ICS.UserDefined, 1653 CandidateSet, true, false, false); 1654 if (OvResult == OR_Ambiguous) 1655 Diag(From->getSourceRange().getBegin(), 1656 diag::err_typecheck_ambiguous_condition) 1657 << From->getType() << ToType << From->getSourceRange(); 1658 else if (OvResult == OR_No_Viable_Function && !CandidateSet.empty()) 1659 Diag(From->getSourceRange().getBegin(), 1660 diag::err_typecheck_nonviable_condition) 1661 << From->getType() << ToType << From->getSourceRange(); 1662 else 1663 return false; 1664 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, &From, 1); 1665 return true; 1666} 1667 1668/// CompareImplicitConversionSequences - Compare two implicit 1669/// conversion sequences to determine whether one is better than the 1670/// other or if they are indistinguishable (C++ 13.3.3.2). 1671ImplicitConversionSequence::CompareKind 1672Sema::CompareImplicitConversionSequences(const ImplicitConversionSequence& ICS1, 1673 const ImplicitConversionSequence& ICS2) 1674{ 1675 // (C++ 13.3.3.2p2): When comparing the basic forms of implicit 1676 // conversion sequences (as defined in 13.3.3.1) 1677 // -- a standard conversion sequence (13.3.3.1.1) is a better 1678 // conversion sequence than a user-defined conversion sequence or 1679 // an ellipsis conversion sequence, and 1680 // -- a user-defined conversion sequence (13.3.3.1.2) is a better 1681 // conversion sequence than an ellipsis conversion sequence 1682 // (13.3.3.1.3). 1683 // 1684 // C++0x [over.best.ics]p10: 1685 // For the purpose of ranking implicit conversion sequences as 1686 // described in 13.3.3.2, the ambiguous conversion sequence is 1687 // treated as a user-defined sequence that is indistinguishable 1688 // from any other user-defined conversion sequence. 1689 if (ICS1.getKind() < ICS2.getKind()) { 1690 if (!(ICS1.isUserDefined() && ICS2.isAmbiguous())) 1691 return ImplicitConversionSequence::Better; 1692 } else if (ICS2.getKind() < ICS1.getKind()) { 1693 if (!(ICS2.isUserDefined() && ICS1.isAmbiguous())) 1694 return ImplicitConversionSequence::Worse; 1695 } 1696 1697 if (ICS1.isAmbiguous() || ICS2.isAmbiguous()) 1698 return ImplicitConversionSequence::Indistinguishable; 1699 1700 // Two implicit conversion sequences of the same form are 1701 // indistinguishable conversion sequences unless one of the 1702 // following rules apply: (C++ 13.3.3.2p3): 1703 if (ICS1.isStandard()) 1704 return CompareStandardConversionSequences(ICS1.Standard, ICS2.Standard); 1705 else if (ICS1.isUserDefined()) { 1706 // User-defined conversion sequence U1 is a better conversion 1707 // sequence than another user-defined conversion sequence U2 if 1708 // they contain the same user-defined conversion function or 1709 // constructor and if the second standard conversion sequence of 1710 // U1 is better than the second standard conversion sequence of 1711 // U2 (C++ 13.3.3.2p3). 1712 if (ICS1.UserDefined.ConversionFunction == 1713 ICS2.UserDefined.ConversionFunction) 1714 return CompareStandardConversionSequences(ICS1.UserDefined.After, 1715 ICS2.UserDefined.After); 1716 } 1717 1718 return ImplicitConversionSequence::Indistinguishable; 1719} 1720 1721/// CompareStandardConversionSequences - Compare two standard 1722/// conversion sequences to determine whether one is better than the 1723/// other or if they are indistinguishable (C++ 13.3.3.2p3). 1724ImplicitConversionSequence::CompareKind 1725Sema::CompareStandardConversionSequences(const StandardConversionSequence& SCS1, 1726 const StandardConversionSequence& SCS2) 1727{ 1728 // Standard conversion sequence S1 is a better conversion sequence 1729 // than standard conversion sequence S2 if (C++ 13.3.3.2p3): 1730 1731 // -- S1 is a proper subsequence of S2 (comparing the conversion 1732 // sequences in the canonical form defined by 13.3.3.1.1, 1733 // excluding any Lvalue Transformation; the identity conversion 1734 // sequence is considered to be a subsequence of any 1735 // non-identity conversion sequence) or, if not that, 1736 if (SCS1.Second == SCS2.Second && SCS1.Third == SCS2.Third) 1737 // Neither is a proper subsequence of the other. Do nothing. 1738 ; 1739 else if ((SCS1.Second == ICK_Identity && SCS1.Third == SCS2.Third) || 1740 (SCS1.Third == ICK_Identity && SCS1.Second == SCS2.Second) || 1741 (SCS1.Second == ICK_Identity && 1742 SCS1.Third == ICK_Identity)) 1743 // SCS1 is a proper subsequence of SCS2. 1744 return ImplicitConversionSequence::Better; 1745 else if ((SCS2.Second == ICK_Identity && SCS2.Third == SCS1.Third) || 1746 (SCS2.Third == ICK_Identity && SCS2.Second == SCS1.Second) || 1747 (SCS2.Second == ICK_Identity && 1748 SCS2.Third == ICK_Identity)) 1749 // SCS2 is a proper subsequence of SCS1. 1750 return ImplicitConversionSequence::Worse; 1751 1752 // -- the rank of S1 is better than the rank of S2 (by the rules 1753 // defined below), or, if not that, 1754 ImplicitConversionRank Rank1 = SCS1.getRank(); 1755 ImplicitConversionRank Rank2 = SCS2.getRank(); 1756 if (Rank1 < Rank2) 1757 return ImplicitConversionSequence::Better; 1758 else if (Rank2 < Rank1) 1759 return ImplicitConversionSequence::Worse; 1760 1761 // (C++ 13.3.3.2p4): Two conversion sequences with the same rank 1762 // are indistinguishable unless one of the following rules 1763 // applies: 1764 1765 // A conversion that is not a conversion of a pointer, or 1766 // pointer to member, to bool is better than another conversion 1767 // that is such a conversion. 1768 if (SCS1.isPointerConversionToBool() != SCS2.isPointerConversionToBool()) 1769 return SCS2.isPointerConversionToBool() 1770 ? ImplicitConversionSequence::Better 1771 : ImplicitConversionSequence::Worse; 1772 1773 // C++ [over.ics.rank]p4b2: 1774 // 1775 // If class B is derived directly or indirectly from class A, 1776 // conversion of B* to A* is better than conversion of B* to 1777 // void*, and conversion of A* to void* is better than conversion 1778 // of B* to void*. 1779 bool SCS1ConvertsToVoid 1780 = SCS1.isPointerConversionToVoidPointer(Context); 1781 bool SCS2ConvertsToVoid 1782 = SCS2.isPointerConversionToVoidPointer(Context); 1783 if (SCS1ConvertsToVoid != SCS2ConvertsToVoid) { 1784 // Exactly one of the conversion sequences is a conversion to 1785 // a void pointer; it's the worse conversion. 1786 return SCS2ConvertsToVoid ? ImplicitConversionSequence::Better 1787 : ImplicitConversionSequence::Worse; 1788 } else if (!SCS1ConvertsToVoid && !SCS2ConvertsToVoid) { 1789 // Neither conversion sequence converts to a void pointer; compare 1790 // their derived-to-base conversions. 1791 if (ImplicitConversionSequence::CompareKind DerivedCK 1792 = CompareDerivedToBaseConversions(SCS1, SCS2)) 1793 return DerivedCK; 1794 } else if (SCS1ConvertsToVoid && SCS2ConvertsToVoid) { 1795 // Both conversion sequences are conversions to void 1796 // pointers. Compare the source types to determine if there's an 1797 // inheritance relationship in their sources. 1798 QualType FromType1 = SCS1.getFromType(); 1799 QualType FromType2 = SCS2.getFromType(); 1800 1801 // Adjust the types we're converting from via the array-to-pointer 1802 // conversion, if we need to. 1803 if (SCS1.First == ICK_Array_To_Pointer) 1804 FromType1 = Context.getArrayDecayedType(FromType1); 1805 if (SCS2.First == ICK_Array_To_Pointer) 1806 FromType2 = Context.getArrayDecayedType(FromType2); 1807 1808 QualType FromPointee1 1809 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1810 QualType FromPointee2 1811 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1812 1813 if (IsDerivedFrom(FromPointee2, FromPointee1)) 1814 return ImplicitConversionSequence::Better; 1815 else if (IsDerivedFrom(FromPointee1, FromPointee2)) 1816 return ImplicitConversionSequence::Worse; 1817 1818 // Objective-C++: If one interface is more specific than the 1819 // other, it is the better one. 1820 const ObjCInterfaceType* FromIface1 = FromPointee1->getAs<ObjCInterfaceType>(); 1821 const ObjCInterfaceType* FromIface2 = FromPointee2->getAs<ObjCInterfaceType>(); 1822 if (FromIface1 && FromIface1) { 1823 if (Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 1824 return ImplicitConversionSequence::Better; 1825 else if (Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 1826 return ImplicitConversionSequence::Worse; 1827 } 1828 } 1829 1830 // Compare based on qualification conversions (C++ 13.3.3.2p3, 1831 // bullet 3). 1832 if (ImplicitConversionSequence::CompareKind QualCK 1833 = CompareQualificationConversions(SCS1, SCS2)) 1834 return QualCK; 1835 1836 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding) { 1837 // C++0x [over.ics.rank]p3b4: 1838 // -- S1 and S2 are reference bindings (8.5.3) and neither refers to an 1839 // implicit object parameter of a non-static member function declared 1840 // without a ref-qualifier, and S1 binds an rvalue reference to an 1841 // rvalue and S2 binds an lvalue reference. 1842 // FIXME: We don't know if we're dealing with the implicit object parameter, 1843 // or if the member function in this case has a ref qualifier. 1844 // (Of course, we don't have ref qualifiers yet.) 1845 if (SCS1.RRefBinding != SCS2.RRefBinding) 1846 return SCS1.RRefBinding ? ImplicitConversionSequence::Better 1847 : ImplicitConversionSequence::Worse; 1848 1849 // C++ [over.ics.rank]p3b4: 1850 // -- S1 and S2 are reference bindings (8.5.3), and the types to 1851 // which the references refer are the same type except for 1852 // top-level cv-qualifiers, and the type to which the reference 1853 // initialized by S2 refers is more cv-qualified than the type 1854 // to which the reference initialized by S1 refers. 1855 QualType T1 = SCS1.getToType(); 1856 QualType T2 = SCS2.getToType(); 1857 T1 = Context.getCanonicalType(T1); 1858 T2 = Context.getCanonicalType(T2); 1859 Qualifiers T1Quals, T2Quals; 1860 QualType UnqualT1 = Context.getUnqualifiedArrayType(T1, T1Quals); 1861 QualType UnqualT2 = Context.getUnqualifiedArrayType(T2, T2Quals); 1862 if (UnqualT1 == UnqualT2) { 1863 // If the type is an array type, promote the element qualifiers to the type 1864 // for comparison. 1865 if (isa<ArrayType>(T1) && T1Quals) 1866 T1 = Context.getQualifiedType(UnqualT1, T1Quals); 1867 if (isa<ArrayType>(T2) && T2Quals) 1868 T2 = Context.getQualifiedType(UnqualT2, T2Quals); 1869 if (T2.isMoreQualifiedThan(T1)) 1870 return ImplicitConversionSequence::Better; 1871 else if (T1.isMoreQualifiedThan(T2)) 1872 return ImplicitConversionSequence::Worse; 1873 } 1874 } 1875 1876 return ImplicitConversionSequence::Indistinguishable; 1877} 1878 1879/// CompareQualificationConversions - Compares two standard conversion 1880/// sequences to determine whether they can be ranked based on their 1881/// qualification conversions (C++ 13.3.3.2p3 bullet 3). 1882ImplicitConversionSequence::CompareKind 1883Sema::CompareQualificationConversions(const StandardConversionSequence& SCS1, 1884 const StandardConversionSequence& SCS2) { 1885 // C++ 13.3.3.2p3: 1886 // -- S1 and S2 differ only in their qualification conversion and 1887 // yield similar types T1 and T2 (C++ 4.4), respectively, and the 1888 // cv-qualification signature of type T1 is a proper subset of 1889 // the cv-qualification signature of type T2, and S1 is not the 1890 // deprecated string literal array-to-pointer conversion (4.2). 1891 if (SCS1.First != SCS2.First || SCS1.Second != SCS2.Second || 1892 SCS1.Third != SCS2.Third || SCS1.Third != ICK_Qualification) 1893 return ImplicitConversionSequence::Indistinguishable; 1894 1895 // FIXME: the example in the standard doesn't use a qualification 1896 // conversion (!) 1897 QualType T1 = QualType::getFromOpaquePtr(SCS1.ToTypePtr); 1898 QualType T2 = QualType::getFromOpaquePtr(SCS2.ToTypePtr); 1899 T1 = Context.getCanonicalType(T1); 1900 T2 = Context.getCanonicalType(T2); 1901 Qualifiers T1Quals, T2Quals; 1902 QualType UnqualT1 = Context.getUnqualifiedArrayType(T1, T1Quals); 1903 QualType UnqualT2 = Context.getUnqualifiedArrayType(T2, T2Quals); 1904 1905 // If the types are the same, we won't learn anything by unwrapped 1906 // them. 1907 if (UnqualT1 == UnqualT2) 1908 return ImplicitConversionSequence::Indistinguishable; 1909 1910 // If the type is an array type, promote the element qualifiers to the type 1911 // for comparison. 1912 if (isa<ArrayType>(T1) && T1Quals) 1913 T1 = Context.getQualifiedType(UnqualT1, T1Quals); 1914 if (isa<ArrayType>(T2) && T2Quals) 1915 T2 = Context.getQualifiedType(UnqualT2, T2Quals); 1916 1917 ImplicitConversionSequence::CompareKind Result 1918 = ImplicitConversionSequence::Indistinguishable; 1919 while (UnwrapSimilarPointerTypes(T1, T2)) { 1920 // Within each iteration of the loop, we check the qualifiers to 1921 // determine if this still looks like a qualification 1922 // conversion. Then, if all is well, we unwrap one more level of 1923 // pointers or pointers-to-members and do it all again 1924 // until there are no more pointers or pointers-to-members left 1925 // to unwrap. This essentially mimics what 1926 // IsQualificationConversion does, but here we're checking for a 1927 // strict subset of qualifiers. 1928 if (T1.getCVRQualifiers() == T2.getCVRQualifiers()) 1929 // The qualifiers are the same, so this doesn't tell us anything 1930 // about how the sequences rank. 1931 ; 1932 else if (T2.isMoreQualifiedThan(T1)) { 1933 // T1 has fewer qualifiers, so it could be the better sequence. 1934 if (Result == ImplicitConversionSequence::Worse) 1935 // Neither has qualifiers that are a subset of the other's 1936 // qualifiers. 1937 return ImplicitConversionSequence::Indistinguishable; 1938 1939 Result = ImplicitConversionSequence::Better; 1940 } else if (T1.isMoreQualifiedThan(T2)) { 1941 // T2 has fewer qualifiers, so it could be the better sequence. 1942 if (Result == ImplicitConversionSequence::Better) 1943 // Neither has qualifiers that are a subset of the other's 1944 // qualifiers. 1945 return ImplicitConversionSequence::Indistinguishable; 1946 1947 Result = ImplicitConversionSequence::Worse; 1948 } else { 1949 // Qualifiers are disjoint. 1950 return ImplicitConversionSequence::Indistinguishable; 1951 } 1952 1953 // If the types after this point are equivalent, we're done. 1954 if (Context.hasSameUnqualifiedType(T1, T2)) 1955 break; 1956 } 1957 1958 // Check that the winning standard conversion sequence isn't using 1959 // the deprecated string literal array to pointer conversion. 1960 switch (Result) { 1961 case ImplicitConversionSequence::Better: 1962 if (SCS1.Deprecated) 1963 Result = ImplicitConversionSequence::Indistinguishable; 1964 break; 1965 1966 case ImplicitConversionSequence::Indistinguishable: 1967 break; 1968 1969 case ImplicitConversionSequence::Worse: 1970 if (SCS2.Deprecated) 1971 Result = ImplicitConversionSequence::Indistinguishable; 1972 break; 1973 } 1974 1975 return Result; 1976} 1977 1978/// CompareDerivedToBaseConversions - Compares two standard conversion 1979/// sequences to determine whether they can be ranked based on their 1980/// various kinds of derived-to-base conversions (C++ 1981/// [over.ics.rank]p4b3). As part of these checks, we also look at 1982/// conversions between Objective-C interface types. 1983ImplicitConversionSequence::CompareKind 1984Sema::CompareDerivedToBaseConversions(const StandardConversionSequence& SCS1, 1985 const StandardConversionSequence& SCS2) { 1986 QualType FromType1 = SCS1.getFromType(); 1987 QualType ToType1 = SCS1.getToType(); 1988 QualType FromType2 = SCS2.getFromType(); 1989 QualType ToType2 = SCS2.getToType(); 1990 1991 // Adjust the types we're converting from via the array-to-pointer 1992 // conversion, if we need to. 1993 if (SCS1.First == ICK_Array_To_Pointer) 1994 FromType1 = Context.getArrayDecayedType(FromType1); 1995 if (SCS2.First == ICK_Array_To_Pointer) 1996 FromType2 = Context.getArrayDecayedType(FromType2); 1997 1998 // Canonicalize all of the types. 1999 FromType1 = Context.getCanonicalType(FromType1); 2000 ToType1 = Context.getCanonicalType(ToType1); 2001 FromType2 = Context.getCanonicalType(FromType2); 2002 ToType2 = Context.getCanonicalType(ToType2); 2003 2004 // C++ [over.ics.rank]p4b3: 2005 // 2006 // If class B is derived directly or indirectly from class A and 2007 // class C is derived directly or indirectly from B, 2008 // 2009 // For Objective-C, we let A, B, and C also be Objective-C 2010 // interfaces. 2011 2012 // Compare based on pointer conversions. 2013 if (SCS1.Second == ICK_Pointer_Conversion && 2014 SCS2.Second == ICK_Pointer_Conversion && 2015 /*FIXME: Remove if Objective-C id conversions get their own rank*/ 2016 FromType1->isPointerType() && FromType2->isPointerType() && 2017 ToType1->isPointerType() && ToType2->isPointerType()) { 2018 QualType FromPointee1 2019 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2020 QualType ToPointee1 2021 = ToType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2022 QualType FromPointee2 2023 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2024 QualType ToPointee2 2025 = ToType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2026 2027 const ObjCInterfaceType* FromIface1 = FromPointee1->getAs<ObjCInterfaceType>(); 2028 const ObjCInterfaceType* FromIface2 = FromPointee2->getAs<ObjCInterfaceType>(); 2029 const ObjCInterfaceType* ToIface1 = ToPointee1->getAs<ObjCInterfaceType>(); 2030 const ObjCInterfaceType* ToIface2 = ToPointee2->getAs<ObjCInterfaceType>(); 2031 2032 // -- conversion of C* to B* is better than conversion of C* to A*, 2033 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 2034 if (IsDerivedFrom(ToPointee1, ToPointee2)) 2035 return ImplicitConversionSequence::Better; 2036 else if (IsDerivedFrom(ToPointee2, ToPointee1)) 2037 return ImplicitConversionSequence::Worse; 2038 2039 if (ToIface1 && ToIface2) { 2040 if (Context.canAssignObjCInterfaces(ToIface2, ToIface1)) 2041 return ImplicitConversionSequence::Better; 2042 else if (Context.canAssignObjCInterfaces(ToIface1, ToIface2)) 2043 return ImplicitConversionSequence::Worse; 2044 } 2045 } 2046 2047 // -- conversion of B* to A* is better than conversion of C* to A*, 2048 if (FromPointee1 != FromPointee2 && ToPointee1 == ToPointee2) { 2049 if (IsDerivedFrom(FromPointee2, FromPointee1)) 2050 return ImplicitConversionSequence::Better; 2051 else if (IsDerivedFrom(FromPointee1, FromPointee2)) 2052 return ImplicitConversionSequence::Worse; 2053 2054 if (FromIface1 && FromIface2) { 2055 if (Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 2056 return ImplicitConversionSequence::Better; 2057 else if (Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 2058 return ImplicitConversionSequence::Worse; 2059 } 2060 } 2061 } 2062 2063 // Compare based on reference bindings. 2064 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding && 2065 SCS1.Second == ICK_Derived_To_Base) { 2066 // -- binding of an expression of type C to a reference of type 2067 // B& is better than binding an expression of type C to a 2068 // reference of type A&, 2069 if (Context.hasSameUnqualifiedType(FromType1, FromType2) && 2070 !Context.hasSameUnqualifiedType(ToType1, ToType2)) { 2071 if (IsDerivedFrom(ToType1, ToType2)) 2072 return ImplicitConversionSequence::Better; 2073 else if (IsDerivedFrom(ToType2, ToType1)) 2074 return ImplicitConversionSequence::Worse; 2075 } 2076 2077 // -- binding of an expression of type B to a reference of type 2078 // A& is better than binding an expression of type C to a 2079 // reference of type A&, 2080 if (!Context.hasSameUnqualifiedType(FromType1, FromType2) && 2081 Context.hasSameUnqualifiedType(ToType1, ToType2)) { 2082 if (IsDerivedFrom(FromType2, FromType1)) 2083 return ImplicitConversionSequence::Better; 2084 else if (IsDerivedFrom(FromType1, FromType2)) 2085 return ImplicitConversionSequence::Worse; 2086 } 2087 } 2088 2089 // Ranking of member-pointer types. 2090 if (SCS1.Second == ICK_Pointer_Member && SCS2.Second == ICK_Pointer_Member && 2091 FromType1->isMemberPointerType() && FromType2->isMemberPointerType() && 2092 ToType1->isMemberPointerType() && ToType2->isMemberPointerType()) { 2093 const MemberPointerType * FromMemPointer1 = 2094 FromType1->getAs<MemberPointerType>(); 2095 const MemberPointerType * ToMemPointer1 = 2096 ToType1->getAs<MemberPointerType>(); 2097 const MemberPointerType * FromMemPointer2 = 2098 FromType2->getAs<MemberPointerType>(); 2099 const MemberPointerType * ToMemPointer2 = 2100 ToType2->getAs<MemberPointerType>(); 2101 const Type *FromPointeeType1 = FromMemPointer1->getClass(); 2102 const Type *ToPointeeType1 = ToMemPointer1->getClass(); 2103 const Type *FromPointeeType2 = FromMemPointer2->getClass(); 2104 const Type *ToPointeeType2 = ToMemPointer2->getClass(); 2105 QualType FromPointee1 = QualType(FromPointeeType1, 0).getUnqualifiedType(); 2106 QualType ToPointee1 = QualType(ToPointeeType1, 0).getUnqualifiedType(); 2107 QualType FromPointee2 = QualType(FromPointeeType2, 0).getUnqualifiedType(); 2108 QualType ToPointee2 = QualType(ToPointeeType2, 0).getUnqualifiedType(); 2109 // conversion of A::* to B::* is better than conversion of A::* to C::*, 2110 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 2111 if (IsDerivedFrom(ToPointee1, ToPointee2)) 2112 return ImplicitConversionSequence::Worse; 2113 else if (IsDerivedFrom(ToPointee2, ToPointee1)) 2114 return ImplicitConversionSequence::Better; 2115 } 2116 // conversion of B::* to C::* is better than conversion of A::* to C::* 2117 if (ToPointee1 == ToPointee2 && FromPointee1 != FromPointee2) { 2118 if (IsDerivedFrom(FromPointee1, FromPointee2)) 2119 return ImplicitConversionSequence::Better; 2120 else if (IsDerivedFrom(FromPointee2, FromPointee1)) 2121 return ImplicitConversionSequence::Worse; 2122 } 2123 } 2124 2125 if (SCS1.CopyConstructor && SCS2.CopyConstructor && 2126 SCS1.Second == ICK_Derived_To_Base) { 2127 // -- conversion of C to B is better than conversion of C to A, 2128 if (Context.hasSameUnqualifiedType(FromType1, FromType2) && 2129 !Context.hasSameUnqualifiedType(ToType1, ToType2)) { 2130 if (IsDerivedFrom(ToType1, ToType2)) 2131 return ImplicitConversionSequence::Better; 2132 else if (IsDerivedFrom(ToType2, ToType1)) 2133 return ImplicitConversionSequence::Worse; 2134 } 2135 2136 // -- conversion of B to A is better than conversion of C to A. 2137 if (!Context.hasSameUnqualifiedType(FromType1, FromType2) && 2138 Context.hasSameUnqualifiedType(ToType1, ToType2)) { 2139 if (IsDerivedFrom(FromType2, FromType1)) 2140 return ImplicitConversionSequence::Better; 2141 else if (IsDerivedFrom(FromType1, FromType2)) 2142 return ImplicitConversionSequence::Worse; 2143 } 2144 } 2145 2146 return ImplicitConversionSequence::Indistinguishable; 2147} 2148 2149/// TryCopyInitialization - Try to copy-initialize a value of type 2150/// ToType from the expression From. Return the implicit conversion 2151/// sequence required to pass this argument, which may be a bad 2152/// conversion sequence (meaning that the argument cannot be passed to 2153/// a parameter of this type). If @p SuppressUserConversions, then we 2154/// do not permit any user-defined conversion sequences. If @p ForceRValue, 2155/// then we treat @p From as an rvalue, even if it is an lvalue. 2156ImplicitConversionSequence 2157Sema::TryCopyInitialization(Expr *From, QualType ToType, 2158 bool SuppressUserConversions, bool ForceRValue, 2159 bool InOverloadResolution) { 2160 if (ToType->isReferenceType()) { 2161 ImplicitConversionSequence ICS; 2162 ICS.Bad.init(BadConversionSequence::no_conversion, From, ToType); 2163 CheckReferenceInit(From, ToType, 2164 /*FIXME:*/From->getLocStart(), 2165 SuppressUserConversions, 2166 /*AllowExplicit=*/false, 2167 ForceRValue, 2168 &ICS); 2169 return ICS; 2170 } else { 2171 return TryImplicitConversion(From, ToType, 2172 SuppressUserConversions, 2173 /*AllowExplicit=*/false, 2174 ForceRValue, 2175 InOverloadResolution); 2176 } 2177} 2178 2179/// PerformCopyInitialization - Copy-initialize an object of type @p ToType with 2180/// the expression @p From. Returns true (and emits a diagnostic) if there was 2181/// an error, returns false if the initialization succeeded. Elidable should 2182/// be true when the copy may be elided (C++ 12.8p15). Overload resolution works 2183/// differently in C++0x for this case. 2184bool Sema::PerformCopyInitialization(Expr *&From, QualType ToType, 2185 AssignmentAction Action, bool Elidable) { 2186 if (!getLangOptions().CPlusPlus) { 2187 // In C, argument passing is the same as performing an assignment. 2188 QualType FromType = From->getType(); 2189 2190 AssignConvertType ConvTy = 2191 CheckSingleAssignmentConstraints(ToType, From); 2192 if (ConvTy != Compatible && 2193 CheckTransparentUnionArgumentConstraints(ToType, From) == Compatible) 2194 ConvTy = Compatible; 2195 2196 return DiagnoseAssignmentResult(ConvTy, From->getLocStart(), ToType, 2197 FromType, From, Action); 2198 } 2199 2200 if (ToType->isReferenceType()) 2201 return CheckReferenceInit(From, ToType, 2202 /*FIXME:*/From->getLocStart(), 2203 /*SuppressUserConversions=*/false, 2204 /*AllowExplicit=*/false, 2205 /*ForceRValue=*/false); 2206 2207 if (!PerformImplicitConversion(From, ToType, Action, 2208 /*AllowExplicit=*/false, Elidable)) 2209 return false; 2210 if (!DiagnoseMultipleUserDefinedConversion(From, ToType)) 2211 return Diag(From->getSourceRange().getBegin(), 2212 diag::err_typecheck_convert_incompatible) 2213 << ToType << From->getType() << Action << From->getSourceRange(); 2214 return true; 2215} 2216 2217/// TryObjectArgumentInitialization - Try to initialize the object 2218/// parameter of the given member function (@c Method) from the 2219/// expression @p From. 2220ImplicitConversionSequence 2221Sema::TryObjectArgumentInitialization(QualType OrigFromType, 2222 CXXMethodDecl *Method, 2223 CXXRecordDecl *ActingContext) { 2224 QualType ClassType = Context.getTypeDeclType(ActingContext); 2225 // [class.dtor]p2: A destructor can be invoked for a const, volatile or 2226 // const volatile object. 2227 unsigned Quals = isa<CXXDestructorDecl>(Method) ? 2228 Qualifiers::Const | Qualifiers::Volatile : Method->getTypeQualifiers(); 2229 QualType ImplicitParamType = Context.getCVRQualifiedType(ClassType, Quals); 2230 2231 // Set up the conversion sequence as a "bad" conversion, to allow us 2232 // to exit early. 2233 ImplicitConversionSequence ICS; 2234 ICS.Standard.setAsIdentityConversion(); 2235 ICS.setBad(); 2236 2237 // We need to have an object of class type. 2238 QualType FromType = OrigFromType; 2239 if (const PointerType *PT = FromType->getAs<PointerType>()) 2240 FromType = PT->getPointeeType(); 2241 2242 assert(FromType->isRecordType()); 2243 2244 // The implicit object parameter is has the type "reference to cv X", 2245 // where X is the class of which the function is a member 2246 // (C++ [over.match.funcs]p4). However, when finding an implicit 2247 // conversion sequence for the argument, we are not allowed to 2248 // create temporaries or perform user-defined conversions 2249 // (C++ [over.match.funcs]p5). We perform a simplified version of 2250 // reference binding here, that allows class rvalues to bind to 2251 // non-constant references. 2252 2253 // First check the qualifiers. We don't care about lvalue-vs-rvalue 2254 // with the implicit object parameter (C++ [over.match.funcs]p5). 2255 QualType FromTypeCanon = Context.getCanonicalType(FromType); 2256 if (ImplicitParamType.getCVRQualifiers() 2257 != FromTypeCanon.getLocalCVRQualifiers() && 2258 !ImplicitParamType.isAtLeastAsQualifiedAs(FromTypeCanon)) { 2259 ICS.Bad.init(BadConversionSequence::bad_qualifiers, 2260 OrigFromType, ImplicitParamType); 2261 return ICS; 2262 } 2263 2264 // Check that we have either the same type or a derived type. It 2265 // affects the conversion rank. 2266 QualType ClassTypeCanon = Context.getCanonicalType(ClassType); 2267 if (ClassTypeCanon == FromTypeCanon.getLocalUnqualifiedType()) 2268 ICS.Standard.Second = ICK_Identity; 2269 else if (IsDerivedFrom(FromType, ClassType)) 2270 ICS.Standard.Second = ICK_Derived_To_Base; 2271 else { 2272 ICS.Bad.init(BadConversionSequence::unrelated_class, FromType, ImplicitParamType); 2273 return ICS; 2274 } 2275 2276 // Success. Mark this as a reference binding. 2277 ICS.setStandard(); 2278 ICS.Standard.setFromType(FromType); 2279 ICS.Standard.setToType(ImplicitParamType); 2280 ICS.Standard.ReferenceBinding = true; 2281 ICS.Standard.DirectBinding = true; 2282 ICS.Standard.RRefBinding = false; 2283 return ICS; 2284} 2285 2286/// PerformObjectArgumentInitialization - Perform initialization of 2287/// the implicit object parameter for the given Method with the given 2288/// expression. 2289bool 2290Sema::PerformObjectArgumentInitialization(Expr *&From, CXXMethodDecl *Method) { 2291 QualType FromRecordType, DestType; 2292 QualType ImplicitParamRecordType = 2293 Method->getThisType(Context)->getAs<PointerType>()->getPointeeType(); 2294 2295 if (const PointerType *PT = From->getType()->getAs<PointerType>()) { 2296 FromRecordType = PT->getPointeeType(); 2297 DestType = Method->getThisType(Context); 2298 } else { 2299 FromRecordType = From->getType(); 2300 DestType = ImplicitParamRecordType; 2301 } 2302 2303 // Note that we always use the true parent context when performing 2304 // the actual argument initialization. 2305 ImplicitConversionSequence ICS 2306 = TryObjectArgumentInitialization(From->getType(), Method, 2307 Method->getParent()); 2308 if (ICS.isBad()) 2309 return Diag(From->getSourceRange().getBegin(), 2310 diag::err_implicit_object_parameter_init) 2311 << ImplicitParamRecordType << FromRecordType << From->getSourceRange(); 2312 2313 if (ICS.Standard.Second == ICK_Derived_To_Base && 2314 CheckDerivedToBaseConversion(FromRecordType, 2315 ImplicitParamRecordType, 2316 From->getSourceRange().getBegin(), 2317 From->getSourceRange())) 2318 return true; 2319 2320 ImpCastExprToType(From, DestType, CastExpr::CK_DerivedToBase, 2321 /*isLvalue=*/true); 2322 return false; 2323} 2324 2325/// TryContextuallyConvertToBool - Attempt to contextually convert the 2326/// expression From to bool (C++0x [conv]p3). 2327ImplicitConversionSequence Sema::TryContextuallyConvertToBool(Expr *From) { 2328 return TryImplicitConversion(From, Context.BoolTy, 2329 // FIXME: Are these flags correct? 2330 /*SuppressUserConversions=*/false, 2331 /*AllowExplicit=*/true, 2332 /*ForceRValue=*/false, 2333 /*InOverloadResolution=*/false); 2334} 2335 2336/// PerformContextuallyConvertToBool - Perform a contextual conversion 2337/// of the expression From to bool (C++0x [conv]p3). 2338bool Sema::PerformContextuallyConvertToBool(Expr *&From) { 2339 ImplicitConversionSequence ICS = TryContextuallyConvertToBool(From); 2340 if (!ICS.isBad()) 2341 return PerformImplicitConversion(From, Context.BoolTy, ICS, AA_Converting); 2342 2343 if (!DiagnoseMultipleUserDefinedConversion(From, Context.BoolTy)) 2344 return Diag(From->getSourceRange().getBegin(), 2345 diag::err_typecheck_bool_condition) 2346 << From->getType() << From->getSourceRange(); 2347 return true; 2348} 2349 2350/// AddOverloadCandidate - Adds the given function to the set of 2351/// candidate functions, using the given function call arguments. If 2352/// @p SuppressUserConversions, then don't allow user-defined 2353/// conversions via constructors or conversion operators. 2354/// If @p ForceRValue, treat all arguments as rvalues. This is a slightly 2355/// hacky way to implement the overloading rules for elidable copy 2356/// initialization in C++0x (C++0x 12.8p15). 2357/// 2358/// \para PartialOverloading true if we are performing "partial" overloading 2359/// based on an incomplete set of function arguments. This feature is used by 2360/// code completion. 2361void 2362Sema::AddOverloadCandidate(FunctionDecl *Function, 2363 Expr **Args, unsigned NumArgs, 2364 OverloadCandidateSet& CandidateSet, 2365 bool SuppressUserConversions, 2366 bool ForceRValue, 2367 bool PartialOverloading) { 2368 const FunctionProtoType* Proto 2369 = dyn_cast<FunctionProtoType>(Function->getType()->getAs<FunctionType>()); 2370 assert(Proto && "Functions without a prototype cannot be overloaded"); 2371 assert(!Function->getDescribedFunctionTemplate() && 2372 "Use AddTemplateOverloadCandidate for function templates"); 2373 2374 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Function)) { 2375 if (!isa<CXXConstructorDecl>(Method)) { 2376 // If we get here, it's because we're calling a member function 2377 // that is named without a member access expression (e.g., 2378 // "this->f") that was either written explicitly or created 2379 // implicitly. This can happen with a qualified call to a member 2380 // function, e.g., X::f(). We use an empty type for the implied 2381 // object argument (C++ [over.call.func]p3), and the acting context 2382 // is irrelevant. 2383 AddMethodCandidate(Method, Method->getParent(), 2384 QualType(), Args, NumArgs, CandidateSet, 2385 SuppressUserConversions, ForceRValue); 2386 return; 2387 } 2388 // We treat a constructor like a non-member function, since its object 2389 // argument doesn't participate in overload resolution. 2390 } 2391 2392 if (!CandidateSet.isNewCandidate(Function)) 2393 return; 2394 2395 // Overload resolution is always an unevaluated context. 2396 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 2397 2398 if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(Function)){ 2399 // C++ [class.copy]p3: 2400 // A member function template is never instantiated to perform the copy 2401 // of a class object to an object of its class type. 2402 QualType ClassType = Context.getTypeDeclType(Constructor->getParent()); 2403 if (NumArgs == 1 && 2404 Constructor->isCopyConstructorLikeSpecialization() && 2405 Context.hasSameUnqualifiedType(ClassType, Args[0]->getType())) 2406 return; 2407 } 2408 2409 // Add this candidate 2410 CandidateSet.push_back(OverloadCandidate()); 2411 OverloadCandidate& Candidate = CandidateSet.back(); 2412 Candidate.Function = Function; 2413 Candidate.Viable = true; 2414 Candidate.IsSurrogate = false; 2415 Candidate.IgnoreObjectArgument = false; 2416 2417 unsigned NumArgsInProto = Proto->getNumArgs(); 2418 2419 // (C++ 13.3.2p2): A candidate function having fewer than m 2420 // parameters is viable only if it has an ellipsis in its parameter 2421 // list (8.3.5). 2422 if ((NumArgs + (PartialOverloading && NumArgs)) > NumArgsInProto && 2423 !Proto->isVariadic()) { 2424 Candidate.Viable = false; 2425 Candidate.FailureKind = ovl_fail_too_many_arguments; 2426 return; 2427 } 2428 2429 // (C++ 13.3.2p2): A candidate function having more than m parameters 2430 // is viable only if the (m+1)st parameter has a default argument 2431 // (8.3.6). For the purposes of overload resolution, the 2432 // parameter list is truncated on the right, so that there are 2433 // exactly m parameters. 2434 unsigned MinRequiredArgs = Function->getMinRequiredArguments(); 2435 if (NumArgs < MinRequiredArgs && !PartialOverloading) { 2436 // Not enough arguments. 2437 Candidate.Viable = false; 2438 Candidate.FailureKind = ovl_fail_too_few_arguments; 2439 return; 2440 } 2441 2442 // Determine the implicit conversion sequences for each of the 2443 // arguments. 2444 Candidate.Conversions.resize(NumArgs); 2445 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2446 if (ArgIdx < NumArgsInProto) { 2447 // (C++ 13.3.2p3): for F to be a viable function, there shall 2448 // exist for each argument an implicit conversion sequence 2449 // (13.3.3.1) that converts that argument to the corresponding 2450 // parameter of F. 2451 QualType ParamType = Proto->getArgType(ArgIdx); 2452 Candidate.Conversions[ArgIdx] 2453 = TryCopyInitialization(Args[ArgIdx], ParamType, 2454 SuppressUserConversions, ForceRValue, 2455 /*InOverloadResolution=*/true); 2456 if (Candidate.Conversions[ArgIdx].isBad()) { 2457 Candidate.Viable = false; 2458 Candidate.FailureKind = ovl_fail_bad_conversion; 2459 break; 2460 } 2461 } else { 2462 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2463 // argument for which there is no corresponding parameter is 2464 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2465 Candidate.Conversions[ArgIdx].setEllipsis(); 2466 } 2467 } 2468} 2469 2470/// \brief Add all of the function declarations in the given function set to 2471/// the overload canddiate set. 2472void Sema::AddFunctionCandidates(const FunctionSet &Functions, 2473 Expr **Args, unsigned NumArgs, 2474 OverloadCandidateSet& CandidateSet, 2475 bool SuppressUserConversions) { 2476 for (FunctionSet::const_iterator F = Functions.begin(), 2477 FEnd = Functions.end(); 2478 F != FEnd; ++F) { 2479 // FIXME: using declarations 2480 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*F)) { 2481 if (isa<CXXMethodDecl>(FD) && !cast<CXXMethodDecl>(FD)->isStatic()) 2482 AddMethodCandidate(cast<CXXMethodDecl>(FD), 2483 cast<CXXMethodDecl>(FD)->getParent(), 2484 Args[0]->getType(), Args + 1, NumArgs - 1, 2485 CandidateSet, SuppressUserConversions); 2486 else 2487 AddOverloadCandidate(FD, Args, NumArgs, CandidateSet, 2488 SuppressUserConversions); 2489 } else { 2490 FunctionTemplateDecl *FunTmpl = cast<FunctionTemplateDecl>(*F); 2491 if (isa<CXXMethodDecl>(FunTmpl->getTemplatedDecl()) && 2492 !cast<CXXMethodDecl>(FunTmpl->getTemplatedDecl())->isStatic()) 2493 AddMethodTemplateCandidate(FunTmpl, 2494 cast<CXXRecordDecl>(FunTmpl->getDeclContext()), 2495 /*FIXME: explicit args */ 0, 2496 Args[0]->getType(), Args + 1, NumArgs - 1, 2497 CandidateSet, 2498 SuppressUserConversions); 2499 else 2500 AddTemplateOverloadCandidate(FunTmpl, 2501 /*FIXME: explicit args */ 0, 2502 Args, NumArgs, CandidateSet, 2503 SuppressUserConversions); 2504 } 2505 } 2506} 2507 2508/// AddMethodCandidate - Adds a named decl (which is some kind of 2509/// method) as a method candidate to the given overload set. 2510void Sema::AddMethodCandidate(NamedDecl *Decl, 2511 QualType ObjectType, 2512 Expr **Args, unsigned NumArgs, 2513 OverloadCandidateSet& CandidateSet, 2514 bool SuppressUserConversions, bool ForceRValue) { 2515 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(Decl->getDeclContext()); 2516 2517 if (isa<UsingShadowDecl>(Decl)) 2518 Decl = cast<UsingShadowDecl>(Decl)->getTargetDecl(); 2519 2520 if (FunctionTemplateDecl *TD = dyn_cast<FunctionTemplateDecl>(Decl)) { 2521 assert(isa<CXXMethodDecl>(TD->getTemplatedDecl()) && 2522 "Expected a member function template"); 2523 AddMethodTemplateCandidate(TD, ActingContext, /*ExplicitArgs*/ 0, 2524 ObjectType, Args, NumArgs, 2525 CandidateSet, 2526 SuppressUserConversions, 2527 ForceRValue); 2528 } else { 2529 AddMethodCandidate(cast<CXXMethodDecl>(Decl), ActingContext, 2530 ObjectType, Args, NumArgs, 2531 CandidateSet, SuppressUserConversions, ForceRValue); 2532 } 2533} 2534 2535/// AddMethodCandidate - Adds the given C++ member function to the set 2536/// of candidate functions, using the given function call arguments 2537/// and the object argument (@c Object). For example, in a call 2538/// @c o.f(a1,a2), @c Object will contain @c o and @c Args will contain 2539/// both @c a1 and @c a2. If @p SuppressUserConversions, then don't 2540/// allow user-defined conversions via constructors or conversion 2541/// operators. If @p ForceRValue, treat all arguments as rvalues. This is 2542/// a slightly hacky way to implement the overloading rules for elidable copy 2543/// initialization in C++0x (C++0x 12.8p15). 2544void 2545Sema::AddMethodCandidate(CXXMethodDecl *Method, CXXRecordDecl *ActingContext, 2546 QualType ObjectType, Expr **Args, unsigned NumArgs, 2547 OverloadCandidateSet& CandidateSet, 2548 bool SuppressUserConversions, bool ForceRValue) { 2549 const FunctionProtoType* Proto 2550 = dyn_cast<FunctionProtoType>(Method->getType()->getAs<FunctionType>()); 2551 assert(Proto && "Methods without a prototype cannot be overloaded"); 2552 assert(!isa<CXXConstructorDecl>(Method) && 2553 "Use AddOverloadCandidate for constructors"); 2554 2555 if (!CandidateSet.isNewCandidate(Method)) 2556 return; 2557 2558 // Overload resolution is always an unevaluated context. 2559 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 2560 2561 // Add this candidate 2562 CandidateSet.push_back(OverloadCandidate()); 2563 OverloadCandidate& Candidate = CandidateSet.back(); 2564 Candidate.Function = Method; 2565 Candidate.IsSurrogate = false; 2566 Candidate.IgnoreObjectArgument = false; 2567 2568 unsigned NumArgsInProto = Proto->getNumArgs(); 2569 2570 // (C++ 13.3.2p2): A candidate function having fewer than m 2571 // parameters is viable only if it has an ellipsis in its parameter 2572 // list (8.3.5). 2573 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 2574 Candidate.Viable = false; 2575 Candidate.FailureKind = ovl_fail_too_many_arguments; 2576 return; 2577 } 2578 2579 // (C++ 13.3.2p2): A candidate function having more than m parameters 2580 // is viable only if the (m+1)st parameter has a default argument 2581 // (8.3.6). For the purposes of overload resolution, the 2582 // parameter list is truncated on the right, so that there are 2583 // exactly m parameters. 2584 unsigned MinRequiredArgs = Method->getMinRequiredArguments(); 2585 if (NumArgs < MinRequiredArgs) { 2586 // Not enough arguments. 2587 Candidate.Viable = false; 2588 Candidate.FailureKind = ovl_fail_too_few_arguments; 2589 return; 2590 } 2591 2592 Candidate.Viable = true; 2593 Candidate.Conversions.resize(NumArgs + 1); 2594 2595 if (Method->isStatic() || ObjectType.isNull()) 2596 // The implicit object argument is ignored. 2597 Candidate.IgnoreObjectArgument = true; 2598 else { 2599 // Determine the implicit conversion sequence for the object 2600 // parameter. 2601 Candidate.Conversions[0] 2602 = TryObjectArgumentInitialization(ObjectType, Method, ActingContext); 2603 if (Candidate.Conversions[0].isBad()) { 2604 Candidate.Viable = false; 2605 Candidate.FailureKind = ovl_fail_bad_conversion; 2606 return; 2607 } 2608 } 2609 2610 // Determine the implicit conversion sequences for each of the 2611 // arguments. 2612 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2613 if (ArgIdx < NumArgsInProto) { 2614 // (C++ 13.3.2p3): for F to be a viable function, there shall 2615 // exist for each argument an implicit conversion sequence 2616 // (13.3.3.1) that converts that argument to the corresponding 2617 // parameter of F. 2618 QualType ParamType = Proto->getArgType(ArgIdx); 2619 Candidate.Conversions[ArgIdx + 1] 2620 = TryCopyInitialization(Args[ArgIdx], ParamType, 2621 SuppressUserConversions, ForceRValue, 2622 /*InOverloadResolution=*/true); 2623 if (Candidate.Conversions[ArgIdx + 1].isBad()) { 2624 Candidate.Viable = false; 2625 Candidate.FailureKind = ovl_fail_bad_conversion; 2626 break; 2627 } 2628 } else { 2629 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2630 // argument for which there is no corresponding parameter is 2631 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2632 Candidate.Conversions[ArgIdx + 1].setEllipsis(); 2633 } 2634 } 2635} 2636 2637/// \brief Add a C++ member function template as a candidate to the candidate 2638/// set, using template argument deduction to produce an appropriate member 2639/// function template specialization. 2640void 2641Sema::AddMethodTemplateCandidate(FunctionTemplateDecl *MethodTmpl, 2642 CXXRecordDecl *ActingContext, 2643 const TemplateArgumentListInfo *ExplicitTemplateArgs, 2644 QualType ObjectType, 2645 Expr **Args, unsigned NumArgs, 2646 OverloadCandidateSet& CandidateSet, 2647 bool SuppressUserConversions, 2648 bool ForceRValue) { 2649 if (!CandidateSet.isNewCandidate(MethodTmpl)) 2650 return; 2651 2652 // C++ [over.match.funcs]p7: 2653 // In each case where a candidate is a function template, candidate 2654 // function template specializations are generated using template argument 2655 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 2656 // candidate functions in the usual way.113) A given name can refer to one 2657 // or more function templates and also to a set of overloaded non-template 2658 // functions. In such a case, the candidate functions generated from each 2659 // function template are combined with the set of non-template candidate 2660 // functions. 2661 TemplateDeductionInfo Info(Context); 2662 FunctionDecl *Specialization = 0; 2663 if (TemplateDeductionResult Result 2664 = DeduceTemplateArguments(MethodTmpl, ExplicitTemplateArgs, 2665 Args, NumArgs, Specialization, Info)) { 2666 // FIXME: Record what happened with template argument deduction, so 2667 // that we can give the user a beautiful diagnostic. 2668 (void)Result; 2669 return; 2670 } 2671 2672 // Add the function template specialization produced by template argument 2673 // deduction as a candidate. 2674 assert(Specialization && "Missing member function template specialization?"); 2675 assert(isa<CXXMethodDecl>(Specialization) && 2676 "Specialization is not a member function?"); 2677 AddMethodCandidate(cast<CXXMethodDecl>(Specialization), ActingContext, 2678 ObjectType, Args, NumArgs, 2679 CandidateSet, SuppressUserConversions, ForceRValue); 2680} 2681 2682/// \brief Add a C++ function template specialization as a candidate 2683/// in the candidate set, using template argument deduction to produce 2684/// an appropriate function template specialization. 2685void 2686Sema::AddTemplateOverloadCandidate(FunctionTemplateDecl *FunctionTemplate, 2687 const TemplateArgumentListInfo *ExplicitTemplateArgs, 2688 Expr **Args, unsigned NumArgs, 2689 OverloadCandidateSet& CandidateSet, 2690 bool SuppressUserConversions, 2691 bool ForceRValue) { 2692 if (!CandidateSet.isNewCandidate(FunctionTemplate)) 2693 return; 2694 2695 // C++ [over.match.funcs]p7: 2696 // In each case where a candidate is a function template, candidate 2697 // function template specializations are generated using template argument 2698 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 2699 // candidate functions in the usual way.113) A given name can refer to one 2700 // or more function templates and also to a set of overloaded non-template 2701 // functions. In such a case, the candidate functions generated from each 2702 // function template are combined with the set of non-template candidate 2703 // functions. 2704 TemplateDeductionInfo Info(Context); 2705 FunctionDecl *Specialization = 0; 2706 if (TemplateDeductionResult Result 2707 = DeduceTemplateArguments(FunctionTemplate, ExplicitTemplateArgs, 2708 Args, NumArgs, Specialization, Info)) { 2709 // FIXME: Record what happened with template argument deduction, so 2710 // that we can give the user a beautiful diagnostic. 2711 (void) Result; 2712 2713 CandidateSet.push_back(OverloadCandidate()); 2714 OverloadCandidate &Candidate = CandidateSet.back(); 2715 Candidate.Function = FunctionTemplate->getTemplatedDecl(); 2716 Candidate.Viable = false; 2717 Candidate.FailureKind = ovl_fail_bad_deduction; 2718 Candidate.IsSurrogate = false; 2719 Candidate.IgnoreObjectArgument = false; 2720 return; 2721 } 2722 2723 // Add the function template specialization produced by template argument 2724 // deduction as a candidate. 2725 assert(Specialization && "Missing function template specialization?"); 2726 AddOverloadCandidate(Specialization, Args, NumArgs, CandidateSet, 2727 SuppressUserConversions, ForceRValue); 2728} 2729 2730/// AddConversionCandidate - Add a C++ conversion function as a 2731/// candidate in the candidate set (C++ [over.match.conv], 2732/// C++ [over.match.copy]). From is the expression we're converting from, 2733/// and ToType is the type that we're eventually trying to convert to 2734/// (which may or may not be the same type as the type that the 2735/// conversion function produces). 2736void 2737Sema::AddConversionCandidate(CXXConversionDecl *Conversion, 2738 CXXRecordDecl *ActingContext, 2739 Expr *From, QualType ToType, 2740 OverloadCandidateSet& CandidateSet) { 2741 assert(!Conversion->getDescribedFunctionTemplate() && 2742 "Conversion function templates use AddTemplateConversionCandidate"); 2743 2744 if (!CandidateSet.isNewCandidate(Conversion)) 2745 return; 2746 2747 // Overload resolution is always an unevaluated context. 2748 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 2749 2750 // Add this candidate 2751 CandidateSet.push_back(OverloadCandidate()); 2752 OverloadCandidate& Candidate = CandidateSet.back(); 2753 Candidate.Function = Conversion; 2754 Candidate.IsSurrogate = false; 2755 Candidate.IgnoreObjectArgument = false; 2756 Candidate.FinalConversion.setAsIdentityConversion(); 2757 Candidate.FinalConversion.setFromType(Conversion->getConversionType()); 2758 Candidate.FinalConversion.setToType(ToType); 2759 2760 // Determine the implicit conversion sequence for the implicit 2761 // object parameter. 2762 Candidate.Viable = true; 2763 Candidate.Conversions.resize(1); 2764 Candidate.Conversions[0] 2765 = TryObjectArgumentInitialization(From->getType(), Conversion, 2766 ActingContext); 2767 // Conversion functions to a different type in the base class is visible in 2768 // the derived class. So, a derived to base conversion should not participate 2769 // in overload resolution. 2770 if (Candidate.Conversions[0].Standard.Second == ICK_Derived_To_Base) 2771 Candidate.Conversions[0].Standard.Second = ICK_Identity; 2772 if (Candidate.Conversions[0].isBad()) { 2773 Candidate.Viable = false; 2774 Candidate.FailureKind = ovl_fail_bad_conversion; 2775 return; 2776 } 2777 2778 // We won't go through a user-define type conversion function to convert a 2779 // derived to base as such conversions are given Conversion Rank. They only 2780 // go through a copy constructor. 13.3.3.1.2-p4 [over.ics.user] 2781 QualType FromCanon 2782 = Context.getCanonicalType(From->getType().getUnqualifiedType()); 2783 QualType ToCanon = Context.getCanonicalType(ToType).getUnqualifiedType(); 2784 if (FromCanon == ToCanon || IsDerivedFrom(FromCanon, ToCanon)) { 2785 Candidate.Viable = false; 2786 Candidate.FailureKind = ovl_fail_bad_conversion; 2787 return; 2788 } 2789 2790 2791 // To determine what the conversion from the result of calling the 2792 // conversion function to the type we're eventually trying to 2793 // convert to (ToType), we need to synthesize a call to the 2794 // conversion function and attempt copy initialization from it. This 2795 // makes sure that we get the right semantics with respect to 2796 // lvalues/rvalues and the type. Fortunately, we can allocate this 2797 // call on the stack and we don't need its arguments to be 2798 // well-formed. 2799 DeclRefExpr ConversionRef(Conversion, Conversion->getType(), 2800 From->getLocStart()); 2801 ImplicitCastExpr ConversionFn(Context.getPointerType(Conversion->getType()), 2802 CastExpr::CK_FunctionToPointerDecay, 2803 &ConversionRef, false); 2804 2805 // Note that it is safe to allocate CallExpr on the stack here because 2806 // there are 0 arguments (i.e., nothing is allocated using ASTContext's 2807 // allocator). 2808 CallExpr Call(Context, &ConversionFn, 0, 0, 2809 Conversion->getConversionType().getNonReferenceType(), 2810 From->getLocStart()); 2811 ImplicitConversionSequence ICS = 2812 TryCopyInitialization(&Call, ToType, 2813 /*SuppressUserConversions=*/true, 2814 /*ForceRValue=*/false, 2815 /*InOverloadResolution=*/false); 2816 2817 switch (ICS.getKind()) { 2818 case ImplicitConversionSequence::StandardConversion: 2819 Candidate.FinalConversion = ICS.Standard; 2820 break; 2821 2822 case ImplicitConversionSequence::BadConversion: 2823 Candidate.Viable = false; 2824 Candidate.FailureKind = ovl_fail_bad_conversion; 2825 break; 2826 2827 default: 2828 assert(false && 2829 "Can only end up with a standard conversion sequence or failure"); 2830 } 2831} 2832 2833/// \brief Adds a conversion function template specialization 2834/// candidate to the overload set, using template argument deduction 2835/// to deduce the template arguments of the conversion function 2836/// template from the type that we are converting to (C++ 2837/// [temp.deduct.conv]). 2838void 2839Sema::AddTemplateConversionCandidate(FunctionTemplateDecl *FunctionTemplate, 2840 CXXRecordDecl *ActingDC, 2841 Expr *From, QualType ToType, 2842 OverloadCandidateSet &CandidateSet) { 2843 assert(isa<CXXConversionDecl>(FunctionTemplate->getTemplatedDecl()) && 2844 "Only conversion function templates permitted here"); 2845 2846 if (!CandidateSet.isNewCandidate(FunctionTemplate)) 2847 return; 2848 2849 TemplateDeductionInfo Info(Context); 2850 CXXConversionDecl *Specialization = 0; 2851 if (TemplateDeductionResult Result 2852 = DeduceTemplateArguments(FunctionTemplate, ToType, 2853 Specialization, Info)) { 2854 // FIXME: Record what happened with template argument deduction, so 2855 // that we can give the user a beautiful diagnostic. 2856 (void)Result; 2857 return; 2858 } 2859 2860 // Add the conversion function template specialization produced by 2861 // template argument deduction as a candidate. 2862 assert(Specialization && "Missing function template specialization?"); 2863 AddConversionCandidate(Specialization, ActingDC, From, ToType, CandidateSet); 2864} 2865 2866/// AddSurrogateCandidate - Adds a "surrogate" candidate function that 2867/// converts the given @c Object to a function pointer via the 2868/// conversion function @c Conversion, and then attempts to call it 2869/// with the given arguments (C++ [over.call.object]p2-4). Proto is 2870/// the type of function that we'll eventually be calling. 2871void Sema::AddSurrogateCandidate(CXXConversionDecl *Conversion, 2872 CXXRecordDecl *ActingContext, 2873 const FunctionProtoType *Proto, 2874 QualType ObjectType, 2875 Expr **Args, unsigned NumArgs, 2876 OverloadCandidateSet& CandidateSet) { 2877 if (!CandidateSet.isNewCandidate(Conversion)) 2878 return; 2879 2880 // Overload resolution is always an unevaluated context. 2881 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 2882 2883 CandidateSet.push_back(OverloadCandidate()); 2884 OverloadCandidate& Candidate = CandidateSet.back(); 2885 Candidate.Function = 0; 2886 Candidate.Surrogate = Conversion; 2887 Candidate.Viable = true; 2888 Candidate.IsSurrogate = true; 2889 Candidate.IgnoreObjectArgument = false; 2890 Candidate.Conversions.resize(NumArgs + 1); 2891 2892 // Determine the implicit conversion sequence for the implicit 2893 // object parameter. 2894 ImplicitConversionSequence ObjectInit 2895 = TryObjectArgumentInitialization(ObjectType, Conversion, ActingContext); 2896 if (ObjectInit.isBad()) { 2897 Candidate.Viable = false; 2898 Candidate.FailureKind = ovl_fail_bad_conversion; 2899 return; 2900 } 2901 2902 // The first conversion is actually a user-defined conversion whose 2903 // first conversion is ObjectInit's standard conversion (which is 2904 // effectively a reference binding). Record it as such. 2905 Candidate.Conversions[0].setUserDefined(); 2906 Candidate.Conversions[0].UserDefined.Before = ObjectInit.Standard; 2907 Candidate.Conversions[0].UserDefined.EllipsisConversion = false; 2908 Candidate.Conversions[0].UserDefined.ConversionFunction = Conversion; 2909 Candidate.Conversions[0].UserDefined.After 2910 = Candidate.Conversions[0].UserDefined.Before; 2911 Candidate.Conversions[0].UserDefined.After.setAsIdentityConversion(); 2912 2913 // Find the 2914 unsigned NumArgsInProto = Proto->getNumArgs(); 2915 2916 // (C++ 13.3.2p2): A candidate function having fewer than m 2917 // parameters is viable only if it has an ellipsis in its parameter 2918 // list (8.3.5). 2919 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 2920 Candidate.Viable = false; 2921 Candidate.FailureKind = ovl_fail_too_many_arguments; 2922 return; 2923 } 2924 2925 // Function types don't have any default arguments, so just check if 2926 // we have enough arguments. 2927 if (NumArgs < NumArgsInProto) { 2928 // Not enough arguments. 2929 Candidate.Viable = false; 2930 Candidate.FailureKind = ovl_fail_too_few_arguments; 2931 return; 2932 } 2933 2934 // Determine the implicit conversion sequences for each of the 2935 // arguments. 2936 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2937 if (ArgIdx < NumArgsInProto) { 2938 // (C++ 13.3.2p3): for F to be a viable function, there shall 2939 // exist for each argument an implicit conversion sequence 2940 // (13.3.3.1) that converts that argument to the corresponding 2941 // parameter of F. 2942 QualType ParamType = Proto->getArgType(ArgIdx); 2943 Candidate.Conversions[ArgIdx + 1] 2944 = TryCopyInitialization(Args[ArgIdx], ParamType, 2945 /*SuppressUserConversions=*/false, 2946 /*ForceRValue=*/false, 2947 /*InOverloadResolution=*/false); 2948 if (Candidate.Conversions[ArgIdx + 1].isBad()) { 2949 Candidate.Viable = false; 2950 Candidate.FailureKind = ovl_fail_bad_conversion; 2951 break; 2952 } 2953 } else { 2954 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2955 // argument for which there is no corresponding parameter is 2956 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2957 Candidate.Conversions[ArgIdx + 1].setEllipsis(); 2958 } 2959 } 2960} 2961 2962// FIXME: This will eventually be removed, once we've migrated all of the 2963// operator overloading logic over to the scheme used by binary operators, which 2964// works for template instantiation. 2965void Sema::AddOperatorCandidates(OverloadedOperatorKind Op, Scope *S, 2966 SourceLocation OpLoc, 2967 Expr **Args, unsigned NumArgs, 2968 OverloadCandidateSet& CandidateSet, 2969 SourceRange OpRange) { 2970 FunctionSet Functions; 2971 2972 QualType T1 = Args[0]->getType(); 2973 QualType T2; 2974 if (NumArgs > 1) 2975 T2 = Args[1]->getType(); 2976 2977 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 2978 if (S) 2979 LookupOverloadedOperatorName(Op, S, T1, T2, Functions); 2980 ArgumentDependentLookup(OpName, /*Operator*/true, Args, NumArgs, Functions); 2981 AddFunctionCandidates(Functions, Args, NumArgs, CandidateSet); 2982 AddMemberOperatorCandidates(Op, OpLoc, Args, NumArgs, CandidateSet, OpRange); 2983 AddBuiltinOperatorCandidates(Op, OpLoc, Args, NumArgs, CandidateSet); 2984} 2985 2986/// \brief Add overload candidates for overloaded operators that are 2987/// member functions. 2988/// 2989/// Add the overloaded operator candidates that are member functions 2990/// for the operator Op that was used in an operator expression such 2991/// as "x Op y". , Args/NumArgs provides the operator arguments, and 2992/// CandidateSet will store the added overload candidates. (C++ 2993/// [over.match.oper]). 2994void Sema::AddMemberOperatorCandidates(OverloadedOperatorKind Op, 2995 SourceLocation OpLoc, 2996 Expr **Args, unsigned NumArgs, 2997 OverloadCandidateSet& CandidateSet, 2998 SourceRange OpRange) { 2999 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 3000 3001 // C++ [over.match.oper]p3: 3002 // For a unary operator @ with an operand of a type whose 3003 // cv-unqualified version is T1, and for a binary operator @ with 3004 // a left operand of a type whose cv-unqualified version is T1 and 3005 // a right operand of a type whose cv-unqualified version is T2, 3006 // three sets of candidate functions, designated member 3007 // candidates, non-member candidates and built-in candidates, are 3008 // constructed as follows: 3009 QualType T1 = Args[0]->getType(); 3010 QualType T2; 3011 if (NumArgs > 1) 3012 T2 = Args[1]->getType(); 3013 3014 // -- If T1 is a class type, the set of member candidates is the 3015 // result of the qualified lookup of T1::operator@ 3016 // (13.3.1.1.1); otherwise, the set of member candidates is 3017 // empty. 3018 if (const RecordType *T1Rec = T1->getAs<RecordType>()) { 3019 // Complete the type if it can be completed. Otherwise, we're done. 3020 if (RequireCompleteType(OpLoc, T1, PDiag())) 3021 return; 3022 3023 LookupResult Operators(*this, OpName, OpLoc, LookupOrdinaryName); 3024 LookupQualifiedName(Operators, T1Rec->getDecl()); 3025 Operators.suppressDiagnostics(); 3026 3027 for (LookupResult::iterator Oper = Operators.begin(), 3028 OperEnd = Operators.end(); 3029 Oper != OperEnd; 3030 ++Oper) 3031 AddMethodCandidate(*Oper, Args[0]->getType(), 3032 Args + 1, NumArgs - 1, CandidateSet, 3033 /* SuppressUserConversions = */ false); 3034 } 3035} 3036 3037/// AddBuiltinCandidate - Add a candidate for a built-in 3038/// operator. ResultTy and ParamTys are the result and parameter types 3039/// of the built-in candidate, respectively. Args and NumArgs are the 3040/// arguments being passed to the candidate. IsAssignmentOperator 3041/// should be true when this built-in candidate is an assignment 3042/// operator. NumContextualBoolArguments is the number of arguments 3043/// (at the beginning of the argument list) that will be contextually 3044/// converted to bool. 3045void Sema::AddBuiltinCandidate(QualType ResultTy, QualType *ParamTys, 3046 Expr **Args, unsigned NumArgs, 3047 OverloadCandidateSet& CandidateSet, 3048 bool IsAssignmentOperator, 3049 unsigned NumContextualBoolArguments) { 3050 // Overload resolution is always an unevaluated context. 3051 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 3052 3053 // Add this candidate 3054 CandidateSet.push_back(OverloadCandidate()); 3055 OverloadCandidate& Candidate = CandidateSet.back(); 3056 Candidate.Function = 0; 3057 Candidate.IsSurrogate = false; 3058 Candidate.IgnoreObjectArgument = false; 3059 Candidate.BuiltinTypes.ResultTy = ResultTy; 3060 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 3061 Candidate.BuiltinTypes.ParamTypes[ArgIdx] = ParamTys[ArgIdx]; 3062 3063 // Determine the implicit conversion sequences for each of the 3064 // arguments. 3065 Candidate.Viable = true; 3066 Candidate.Conversions.resize(NumArgs); 3067 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 3068 // C++ [over.match.oper]p4: 3069 // For the built-in assignment operators, conversions of the 3070 // left operand are restricted as follows: 3071 // -- no temporaries are introduced to hold the left operand, and 3072 // -- no user-defined conversions are applied to the left 3073 // operand to achieve a type match with the left-most 3074 // parameter of a built-in candidate. 3075 // 3076 // We block these conversions by turning off user-defined 3077 // conversions, since that is the only way that initialization of 3078 // a reference to a non-class type can occur from something that 3079 // is not of the same type. 3080 if (ArgIdx < NumContextualBoolArguments) { 3081 assert(ParamTys[ArgIdx] == Context.BoolTy && 3082 "Contextual conversion to bool requires bool type"); 3083 Candidate.Conversions[ArgIdx] = TryContextuallyConvertToBool(Args[ArgIdx]); 3084 } else { 3085 Candidate.Conversions[ArgIdx] 3086 = TryCopyInitialization(Args[ArgIdx], ParamTys[ArgIdx], 3087 ArgIdx == 0 && IsAssignmentOperator, 3088 /*ForceRValue=*/false, 3089 /*InOverloadResolution=*/false); 3090 } 3091 if (Candidate.Conversions[ArgIdx].isBad()) { 3092 Candidate.Viable = false; 3093 Candidate.FailureKind = ovl_fail_bad_conversion; 3094 break; 3095 } 3096 } 3097} 3098 3099/// BuiltinCandidateTypeSet - A set of types that will be used for the 3100/// candidate operator functions for built-in operators (C++ 3101/// [over.built]). The types are separated into pointer types and 3102/// enumeration types. 3103class BuiltinCandidateTypeSet { 3104 /// TypeSet - A set of types. 3105 typedef llvm::SmallPtrSet<QualType, 8> TypeSet; 3106 3107 /// PointerTypes - The set of pointer types that will be used in the 3108 /// built-in candidates. 3109 TypeSet PointerTypes; 3110 3111 /// MemberPointerTypes - The set of member pointer types that will be 3112 /// used in the built-in candidates. 3113 TypeSet MemberPointerTypes; 3114 3115 /// EnumerationTypes - The set of enumeration types that will be 3116 /// used in the built-in candidates. 3117 TypeSet EnumerationTypes; 3118 3119 /// Sema - The semantic analysis instance where we are building the 3120 /// candidate type set. 3121 Sema &SemaRef; 3122 3123 /// Context - The AST context in which we will build the type sets. 3124 ASTContext &Context; 3125 3126 bool AddPointerWithMoreQualifiedTypeVariants(QualType Ty, 3127 const Qualifiers &VisibleQuals); 3128 bool AddMemberPointerWithMoreQualifiedTypeVariants(QualType Ty); 3129 3130public: 3131 /// iterator - Iterates through the types that are part of the set. 3132 typedef TypeSet::iterator iterator; 3133 3134 BuiltinCandidateTypeSet(Sema &SemaRef) 3135 : SemaRef(SemaRef), Context(SemaRef.Context) { } 3136 3137 void AddTypesConvertedFrom(QualType Ty, 3138 SourceLocation Loc, 3139 bool AllowUserConversions, 3140 bool AllowExplicitConversions, 3141 const Qualifiers &VisibleTypeConversionsQuals); 3142 3143 /// pointer_begin - First pointer type found; 3144 iterator pointer_begin() { return PointerTypes.begin(); } 3145 3146 /// pointer_end - Past the last pointer type found; 3147 iterator pointer_end() { return PointerTypes.end(); } 3148 3149 /// member_pointer_begin - First member pointer type found; 3150 iterator member_pointer_begin() { return MemberPointerTypes.begin(); } 3151 3152 /// member_pointer_end - Past the last member pointer type found; 3153 iterator member_pointer_end() { return MemberPointerTypes.end(); } 3154 3155 /// enumeration_begin - First enumeration type found; 3156 iterator enumeration_begin() { return EnumerationTypes.begin(); } 3157 3158 /// enumeration_end - Past the last enumeration type found; 3159 iterator enumeration_end() { return EnumerationTypes.end(); } 3160}; 3161 3162/// AddPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty to 3163/// the set of pointer types along with any more-qualified variants of 3164/// that type. For example, if @p Ty is "int const *", this routine 3165/// will add "int const *", "int const volatile *", "int const 3166/// restrict *", and "int const volatile restrict *" to the set of 3167/// pointer types. Returns true if the add of @p Ty itself succeeded, 3168/// false otherwise. 3169/// 3170/// FIXME: what to do about extended qualifiers? 3171bool 3172BuiltinCandidateTypeSet::AddPointerWithMoreQualifiedTypeVariants(QualType Ty, 3173 const Qualifiers &VisibleQuals) { 3174 3175 // Insert this type. 3176 if (!PointerTypes.insert(Ty)) 3177 return false; 3178 3179 const PointerType *PointerTy = Ty->getAs<PointerType>(); 3180 assert(PointerTy && "type was not a pointer type!"); 3181 3182 QualType PointeeTy = PointerTy->getPointeeType(); 3183 // Don't add qualified variants of arrays. For one, they're not allowed 3184 // (the qualifier would sink to the element type), and for another, the 3185 // only overload situation where it matters is subscript or pointer +- int, 3186 // and those shouldn't have qualifier variants anyway. 3187 if (PointeeTy->isArrayType()) 3188 return true; 3189 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 3190 if (const ConstantArrayType *Array =Context.getAsConstantArrayType(PointeeTy)) 3191 BaseCVR = Array->getElementType().getCVRQualifiers(); 3192 bool hasVolatile = VisibleQuals.hasVolatile(); 3193 bool hasRestrict = VisibleQuals.hasRestrict(); 3194 3195 // Iterate through all strict supersets of BaseCVR. 3196 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 3197 if ((CVR | BaseCVR) != CVR) continue; 3198 // Skip over Volatile/Restrict if no Volatile/Restrict found anywhere 3199 // in the types. 3200 if ((CVR & Qualifiers::Volatile) && !hasVolatile) continue; 3201 if ((CVR & Qualifiers::Restrict) && !hasRestrict) continue; 3202 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 3203 PointerTypes.insert(Context.getPointerType(QPointeeTy)); 3204 } 3205 3206 return true; 3207} 3208 3209/// AddMemberPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty 3210/// to the set of pointer types along with any more-qualified variants of 3211/// that type. For example, if @p Ty is "int const *", this routine 3212/// will add "int const *", "int const volatile *", "int const 3213/// restrict *", and "int const volatile restrict *" to the set of 3214/// pointer types. Returns true if the add of @p Ty itself succeeded, 3215/// false otherwise. 3216/// 3217/// FIXME: what to do about extended qualifiers? 3218bool 3219BuiltinCandidateTypeSet::AddMemberPointerWithMoreQualifiedTypeVariants( 3220 QualType Ty) { 3221 // Insert this type. 3222 if (!MemberPointerTypes.insert(Ty)) 3223 return false; 3224 3225 const MemberPointerType *PointerTy = Ty->getAs<MemberPointerType>(); 3226 assert(PointerTy && "type was not a member pointer type!"); 3227 3228 QualType PointeeTy = PointerTy->getPointeeType(); 3229 // Don't add qualified variants of arrays. For one, they're not allowed 3230 // (the qualifier would sink to the element type), and for another, the 3231 // only overload situation where it matters is subscript or pointer +- int, 3232 // and those shouldn't have qualifier variants anyway. 3233 if (PointeeTy->isArrayType()) 3234 return true; 3235 const Type *ClassTy = PointerTy->getClass(); 3236 3237 // Iterate through all strict supersets of the pointee type's CVR 3238 // qualifiers. 3239 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 3240 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 3241 if ((CVR | BaseCVR) != CVR) continue; 3242 3243 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 3244 MemberPointerTypes.insert(Context.getMemberPointerType(QPointeeTy, ClassTy)); 3245 } 3246 3247 return true; 3248} 3249 3250/// AddTypesConvertedFrom - Add each of the types to which the type @p 3251/// Ty can be implicit converted to the given set of @p Types. We're 3252/// primarily interested in pointer types and enumeration types. We also 3253/// take member pointer types, for the conditional operator. 3254/// AllowUserConversions is true if we should look at the conversion 3255/// functions of a class type, and AllowExplicitConversions if we 3256/// should also include the explicit conversion functions of a class 3257/// type. 3258void 3259BuiltinCandidateTypeSet::AddTypesConvertedFrom(QualType Ty, 3260 SourceLocation Loc, 3261 bool AllowUserConversions, 3262 bool AllowExplicitConversions, 3263 const Qualifiers &VisibleQuals) { 3264 // Only deal with canonical types. 3265 Ty = Context.getCanonicalType(Ty); 3266 3267 // Look through reference types; they aren't part of the type of an 3268 // expression for the purposes of conversions. 3269 if (const ReferenceType *RefTy = Ty->getAs<ReferenceType>()) 3270 Ty = RefTy->getPointeeType(); 3271 3272 // We don't care about qualifiers on the type. 3273 Ty = Ty.getLocalUnqualifiedType(); 3274 3275 // If we're dealing with an array type, decay to the pointer. 3276 if (Ty->isArrayType()) 3277 Ty = SemaRef.Context.getArrayDecayedType(Ty); 3278 3279 if (const PointerType *PointerTy = Ty->getAs<PointerType>()) { 3280 QualType PointeeTy = PointerTy->getPointeeType(); 3281 3282 // Insert our type, and its more-qualified variants, into the set 3283 // of types. 3284 if (!AddPointerWithMoreQualifiedTypeVariants(Ty, VisibleQuals)) 3285 return; 3286 } else if (Ty->isMemberPointerType()) { 3287 // Member pointers are far easier, since the pointee can't be converted. 3288 if (!AddMemberPointerWithMoreQualifiedTypeVariants(Ty)) 3289 return; 3290 } else if (Ty->isEnumeralType()) { 3291 EnumerationTypes.insert(Ty); 3292 } else if (AllowUserConversions) { 3293 if (const RecordType *TyRec = Ty->getAs<RecordType>()) { 3294 if (SemaRef.RequireCompleteType(Loc, Ty, 0)) { 3295 // No conversion functions in incomplete types. 3296 return; 3297 } 3298 3299 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 3300 const UnresolvedSetImpl *Conversions 3301 = ClassDecl->getVisibleConversionFunctions(); 3302 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 3303 E = Conversions->end(); I != E; ++I) { 3304 3305 // Skip conversion function templates; they don't tell us anything 3306 // about which builtin types we can convert to. 3307 if (isa<FunctionTemplateDecl>(*I)) 3308 continue; 3309 3310 CXXConversionDecl *Conv = cast<CXXConversionDecl>(*I); 3311 if (AllowExplicitConversions || !Conv->isExplicit()) { 3312 AddTypesConvertedFrom(Conv->getConversionType(), Loc, false, false, 3313 VisibleQuals); 3314 } 3315 } 3316 } 3317 } 3318} 3319 3320/// \brief Helper function for AddBuiltinOperatorCandidates() that adds 3321/// the volatile- and non-volatile-qualified assignment operators for the 3322/// given type to the candidate set. 3323static void AddBuiltinAssignmentOperatorCandidates(Sema &S, 3324 QualType T, 3325 Expr **Args, 3326 unsigned NumArgs, 3327 OverloadCandidateSet &CandidateSet) { 3328 QualType ParamTypes[2]; 3329 3330 // T& operator=(T&, T) 3331 ParamTypes[0] = S.Context.getLValueReferenceType(T); 3332 ParamTypes[1] = T; 3333 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3334 /*IsAssignmentOperator=*/true); 3335 3336 if (!S.Context.getCanonicalType(T).isVolatileQualified()) { 3337 // volatile T& operator=(volatile T&, T) 3338 ParamTypes[0] 3339 = S.Context.getLValueReferenceType(S.Context.getVolatileType(T)); 3340 ParamTypes[1] = T; 3341 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3342 /*IsAssignmentOperator=*/true); 3343 } 3344} 3345 3346/// CollectVRQualifiers - This routine returns Volatile/Restrict qualifiers, 3347/// if any, found in visible type conversion functions found in ArgExpr's type. 3348static Qualifiers CollectVRQualifiers(ASTContext &Context, Expr* ArgExpr) { 3349 Qualifiers VRQuals; 3350 const RecordType *TyRec; 3351 if (const MemberPointerType *RHSMPType = 3352 ArgExpr->getType()->getAs<MemberPointerType>()) 3353 TyRec = cast<RecordType>(RHSMPType->getClass()); 3354 else 3355 TyRec = ArgExpr->getType()->getAs<RecordType>(); 3356 if (!TyRec) { 3357 // Just to be safe, assume the worst case. 3358 VRQuals.addVolatile(); 3359 VRQuals.addRestrict(); 3360 return VRQuals; 3361 } 3362 3363 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 3364 const UnresolvedSetImpl *Conversions = 3365 ClassDecl->getVisibleConversionFunctions(); 3366 3367 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 3368 E = Conversions->end(); I != E; ++I) { 3369 if (CXXConversionDecl *Conv = dyn_cast<CXXConversionDecl>(*I)) { 3370 QualType CanTy = Context.getCanonicalType(Conv->getConversionType()); 3371 if (const ReferenceType *ResTypeRef = CanTy->getAs<ReferenceType>()) 3372 CanTy = ResTypeRef->getPointeeType(); 3373 // Need to go down the pointer/mempointer chain and add qualifiers 3374 // as see them. 3375 bool done = false; 3376 while (!done) { 3377 if (const PointerType *ResTypePtr = CanTy->getAs<PointerType>()) 3378 CanTy = ResTypePtr->getPointeeType(); 3379 else if (const MemberPointerType *ResTypeMPtr = 3380 CanTy->getAs<MemberPointerType>()) 3381 CanTy = ResTypeMPtr->getPointeeType(); 3382 else 3383 done = true; 3384 if (CanTy.isVolatileQualified()) 3385 VRQuals.addVolatile(); 3386 if (CanTy.isRestrictQualified()) 3387 VRQuals.addRestrict(); 3388 if (VRQuals.hasRestrict() && VRQuals.hasVolatile()) 3389 return VRQuals; 3390 } 3391 } 3392 } 3393 return VRQuals; 3394} 3395 3396/// AddBuiltinOperatorCandidates - Add the appropriate built-in 3397/// operator overloads to the candidate set (C++ [over.built]), based 3398/// on the operator @p Op and the arguments given. For example, if the 3399/// operator is a binary '+', this routine might add "int 3400/// operator+(int, int)" to cover integer addition. 3401void 3402Sema::AddBuiltinOperatorCandidates(OverloadedOperatorKind Op, 3403 SourceLocation OpLoc, 3404 Expr **Args, unsigned NumArgs, 3405 OverloadCandidateSet& CandidateSet) { 3406 // The set of "promoted arithmetic types", which are the arithmetic 3407 // types are that preserved by promotion (C++ [over.built]p2). Note 3408 // that the first few of these types are the promoted integral 3409 // types; these types need to be first. 3410 // FIXME: What about complex? 3411 const unsigned FirstIntegralType = 0; 3412 const unsigned LastIntegralType = 13; 3413 const unsigned FirstPromotedIntegralType = 7, 3414 LastPromotedIntegralType = 13; 3415 const unsigned FirstPromotedArithmeticType = 7, 3416 LastPromotedArithmeticType = 16; 3417 const unsigned NumArithmeticTypes = 16; 3418 QualType ArithmeticTypes[NumArithmeticTypes] = { 3419 Context.BoolTy, Context.CharTy, Context.WCharTy, 3420// FIXME: Context.Char16Ty, Context.Char32Ty, 3421 Context.SignedCharTy, Context.ShortTy, 3422 Context.UnsignedCharTy, Context.UnsignedShortTy, 3423 Context.IntTy, Context.LongTy, Context.LongLongTy, 3424 Context.UnsignedIntTy, Context.UnsignedLongTy, Context.UnsignedLongLongTy, 3425 Context.FloatTy, Context.DoubleTy, Context.LongDoubleTy 3426 }; 3427 assert(ArithmeticTypes[FirstPromotedIntegralType] == Context.IntTy && 3428 "Invalid first promoted integral type"); 3429 assert(ArithmeticTypes[LastPromotedIntegralType - 1] 3430 == Context.UnsignedLongLongTy && 3431 "Invalid last promoted integral type"); 3432 assert(ArithmeticTypes[FirstPromotedArithmeticType] == Context.IntTy && 3433 "Invalid first promoted arithmetic type"); 3434 assert(ArithmeticTypes[LastPromotedArithmeticType - 1] 3435 == Context.LongDoubleTy && 3436 "Invalid last promoted arithmetic type"); 3437 3438 // Find all of the types that the arguments can convert to, but only 3439 // if the operator we're looking at has built-in operator candidates 3440 // that make use of these types. 3441 Qualifiers VisibleTypeConversionsQuals; 3442 VisibleTypeConversionsQuals.addConst(); 3443 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 3444 VisibleTypeConversionsQuals += CollectVRQualifiers(Context, Args[ArgIdx]); 3445 3446 BuiltinCandidateTypeSet CandidateTypes(*this); 3447 if (Op == OO_Less || Op == OO_Greater || Op == OO_LessEqual || 3448 Op == OO_GreaterEqual || Op == OO_EqualEqual || Op == OO_ExclaimEqual || 3449 Op == OO_Plus || (Op == OO_Minus && NumArgs == 2) || Op == OO_Equal || 3450 Op == OO_PlusEqual || Op == OO_MinusEqual || Op == OO_Subscript || 3451 Op == OO_ArrowStar || Op == OO_PlusPlus || Op == OO_MinusMinus || 3452 (Op == OO_Star && NumArgs == 1) || Op == OO_Conditional) { 3453 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 3454 CandidateTypes.AddTypesConvertedFrom(Args[ArgIdx]->getType(), 3455 OpLoc, 3456 true, 3457 (Op == OO_Exclaim || 3458 Op == OO_AmpAmp || 3459 Op == OO_PipePipe), 3460 VisibleTypeConversionsQuals); 3461 } 3462 3463 bool isComparison = false; 3464 switch (Op) { 3465 case OO_None: 3466 case NUM_OVERLOADED_OPERATORS: 3467 assert(false && "Expected an overloaded operator"); 3468 break; 3469 3470 case OO_Star: // '*' is either unary or binary 3471 if (NumArgs == 1) 3472 goto UnaryStar; 3473 else 3474 goto BinaryStar; 3475 break; 3476 3477 case OO_Plus: // '+' is either unary or binary 3478 if (NumArgs == 1) 3479 goto UnaryPlus; 3480 else 3481 goto BinaryPlus; 3482 break; 3483 3484 case OO_Minus: // '-' is either unary or binary 3485 if (NumArgs == 1) 3486 goto UnaryMinus; 3487 else 3488 goto BinaryMinus; 3489 break; 3490 3491 case OO_Amp: // '&' is either unary or binary 3492 if (NumArgs == 1) 3493 goto UnaryAmp; 3494 else 3495 goto BinaryAmp; 3496 3497 case OO_PlusPlus: 3498 case OO_MinusMinus: 3499 // C++ [over.built]p3: 3500 // 3501 // For every pair (T, VQ), where T is an arithmetic type, and VQ 3502 // is either volatile or empty, there exist candidate operator 3503 // functions of the form 3504 // 3505 // VQ T& operator++(VQ T&); 3506 // T operator++(VQ T&, int); 3507 // 3508 // C++ [over.built]p4: 3509 // 3510 // For every pair (T, VQ), where T is an arithmetic type other 3511 // than bool, and VQ is either volatile or empty, there exist 3512 // candidate operator functions of the form 3513 // 3514 // VQ T& operator--(VQ T&); 3515 // T operator--(VQ T&, int); 3516 for (unsigned Arith = (Op == OO_PlusPlus? 0 : 1); 3517 Arith < NumArithmeticTypes; ++Arith) { 3518 QualType ArithTy = ArithmeticTypes[Arith]; 3519 QualType ParamTypes[2] 3520 = { Context.getLValueReferenceType(ArithTy), Context.IntTy }; 3521 3522 // Non-volatile version. 3523 if (NumArgs == 1) 3524 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3525 else 3526 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 3527 // heuristic to reduce number of builtin candidates in the set. 3528 // Add volatile version only if there are conversions to a volatile type. 3529 if (VisibleTypeConversionsQuals.hasVolatile()) { 3530 // Volatile version 3531 ParamTypes[0] 3532 = Context.getLValueReferenceType(Context.getVolatileType(ArithTy)); 3533 if (NumArgs == 1) 3534 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3535 else 3536 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 3537 } 3538 } 3539 3540 // C++ [over.built]p5: 3541 // 3542 // For every pair (T, VQ), where T is a cv-qualified or 3543 // cv-unqualified object type, and VQ is either volatile or 3544 // empty, there exist candidate operator functions of the form 3545 // 3546 // T*VQ& operator++(T*VQ&); 3547 // T*VQ& operator--(T*VQ&); 3548 // T* operator++(T*VQ&, int); 3549 // T* operator--(T*VQ&, int); 3550 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3551 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3552 // Skip pointer types that aren't pointers to object types. 3553 if (!(*Ptr)->getAs<PointerType>()->getPointeeType()->isObjectType()) 3554 continue; 3555 3556 QualType ParamTypes[2] = { 3557 Context.getLValueReferenceType(*Ptr), Context.IntTy 3558 }; 3559 3560 // Without volatile 3561 if (NumArgs == 1) 3562 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3563 else 3564 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3565 3566 if (!Context.getCanonicalType(*Ptr).isVolatileQualified() && 3567 VisibleTypeConversionsQuals.hasVolatile()) { 3568 // With volatile 3569 ParamTypes[0] 3570 = Context.getLValueReferenceType(Context.getVolatileType(*Ptr)); 3571 if (NumArgs == 1) 3572 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3573 else 3574 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3575 } 3576 } 3577 break; 3578 3579 UnaryStar: 3580 // C++ [over.built]p6: 3581 // For every cv-qualified or cv-unqualified object type T, there 3582 // exist candidate operator functions of the form 3583 // 3584 // T& operator*(T*); 3585 // 3586 // C++ [over.built]p7: 3587 // For every function type T, there exist candidate operator 3588 // functions of the form 3589 // T& operator*(T*); 3590 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3591 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3592 QualType ParamTy = *Ptr; 3593 QualType PointeeTy = ParamTy->getAs<PointerType>()->getPointeeType(); 3594 AddBuiltinCandidate(Context.getLValueReferenceType(PointeeTy), 3595 &ParamTy, Args, 1, CandidateSet); 3596 } 3597 break; 3598 3599 UnaryPlus: 3600 // C++ [over.built]p8: 3601 // For every type T, there exist candidate operator functions of 3602 // the form 3603 // 3604 // T* operator+(T*); 3605 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3606 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3607 QualType ParamTy = *Ptr; 3608 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet); 3609 } 3610 3611 // Fall through 3612 3613 UnaryMinus: 3614 // C++ [over.built]p9: 3615 // For every promoted arithmetic type T, there exist candidate 3616 // operator functions of the form 3617 // 3618 // T operator+(T); 3619 // T operator-(T); 3620 for (unsigned Arith = FirstPromotedArithmeticType; 3621 Arith < LastPromotedArithmeticType; ++Arith) { 3622 QualType ArithTy = ArithmeticTypes[Arith]; 3623 AddBuiltinCandidate(ArithTy, &ArithTy, Args, 1, CandidateSet); 3624 } 3625 break; 3626 3627 case OO_Tilde: 3628 // C++ [over.built]p10: 3629 // For every promoted integral type T, there exist candidate 3630 // operator functions of the form 3631 // 3632 // T operator~(T); 3633 for (unsigned Int = FirstPromotedIntegralType; 3634 Int < LastPromotedIntegralType; ++Int) { 3635 QualType IntTy = ArithmeticTypes[Int]; 3636 AddBuiltinCandidate(IntTy, &IntTy, Args, 1, CandidateSet); 3637 } 3638 break; 3639 3640 case OO_New: 3641 case OO_Delete: 3642 case OO_Array_New: 3643 case OO_Array_Delete: 3644 case OO_Call: 3645 assert(false && "Special operators don't use AddBuiltinOperatorCandidates"); 3646 break; 3647 3648 case OO_Comma: 3649 UnaryAmp: 3650 case OO_Arrow: 3651 // C++ [over.match.oper]p3: 3652 // -- For the operator ',', the unary operator '&', or the 3653 // operator '->', the built-in candidates set is empty. 3654 break; 3655 3656 case OO_EqualEqual: 3657 case OO_ExclaimEqual: 3658 // C++ [over.match.oper]p16: 3659 // For every pointer to member type T, there exist candidate operator 3660 // functions of the form 3661 // 3662 // bool operator==(T,T); 3663 // bool operator!=(T,T); 3664 for (BuiltinCandidateTypeSet::iterator 3665 MemPtr = CandidateTypes.member_pointer_begin(), 3666 MemPtrEnd = CandidateTypes.member_pointer_end(); 3667 MemPtr != MemPtrEnd; 3668 ++MemPtr) { 3669 QualType ParamTypes[2] = { *MemPtr, *MemPtr }; 3670 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 3671 } 3672 3673 // Fall through 3674 3675 case OO_Less: 3676 case OO_Greater: 3677 case OO_LessEqual: 3678 case OO_GreaterEqual: 3679 // C++ [over.built]p15: 3680 // 3681 // For every pointer or enumeration type T, there exist 3682 // candidate operator functions of the form 3683 // 3684 // bool operator<(T, T); 3685 // bool operator>(T, T); 3686 // bool operator<=(T, T); 3687 // bool operator>=(T, T); 3688 // bool operator==(T, T); 3689 // bool operator!=(T, T); 3690 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3691 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3692 QualType ParamTypes[2] = { *Ptr, *Ptr }; 3693 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 3694 } 3695 for (BuiltinCandidateTypeSet::iterator Enum 3696 = CandidateTypes.enumeration_begin(); 3697 Enum != CandidateTypes.enumeration_end(); ++Enum) { 3698 QualType ParamTypes[2] = { *Enum, *Enum }; 3699 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 3700 } 3701 3702 // Fall through. 3703 isComparison = true; 3704 3705 BinaryPlus: 3706 BinaryMinus: 3707 if (!isComparison) { 3708 // We didn't fall through, so we must have OO_Plus or OO_Minus. 3709 3710 // C++ [over.built]p13: 3711 // 3712 // For every cv-qualified or cv-unqualified object type T 3713 // there exist candidate operator functions of the form 3714 // 3715 // T* operator+(T*, ptrdiff_t); 3716 // T& operator[](T*, ptrdiff_t); [BELOW] 3717 // T* operator-(T*, ptrdiff_t); 3718 // T* operator+(ptrdiff_t, T*); 3719 // T& operator[](ptrdiff_t, T*); [BELOW] 3720 // 3721 // C++ [over.built]p14: 3722 // 3723 // For every T, where T is a pointer to object type, there 3724 // exist candidate operator functions of the form 3725 // 3726 // ptrdiff_t operator-(T, T); 3727 for (BuiltinCandidateTypeSet::iterator Ptr 3728 = CandidateTypes.pointer_begin(); 3729 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3730 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 3731 3732 // operator+(T*, ptrdiff_t) or operator-(T*, ptrdiff_t) 3733 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3734 3735 if (Op == OO_Plus) { 3736 // T* operator+(ptrdiff_t, T*); 3737 ParamTypes[0] = ParamTypes[1]; 3738 ParamTypes[1] = *Ptr; 3739 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3740 } else { 3741 // ptrdiff_t operator-(T, T); 3742 ParamTypes[1] = *Ptr; 3743 AddBuiltinCandidate(Context.getPointerDiffType(), ParamTypes, 3744 Args, 2, CandidateSet); 3745 } 3746 } 3747 } 3748 // Fall through 3749 3750 case OO_Slash: 3751 BinaryStar: 3752 Conditional: 3753 // C++ [over.built]p12: 3754 // 3755 // For every pair of promoted arithmetic types L and R, there 3756 // exist candidate operator functions of the form 3757 // 3758 // LR operator*(L, R); 3759 // LR operator/(L, R); 3760 // LR operator+(L, R); 3761 // LR operator-(L, R); 3762 // bool operator<(L, R); 3763 // bool operator>(L, R); 3764 // bool operator<=(L, R); 3765 // bool operator>=(L, R); 3766 // bool operator==(L, R); 3767 // bool operator!=(L, R); 3768 // 3769 // where LR is the result of the usual arithmetic conversions 3770 // between types L and R. 3771 // 3772 // C++ [over.built]p24: 3773 // 3774 // For every pair of promoted arithmetic types L and R, there exist 3775 // candidate operator functions of the form 3776 // 3777 // LR operator?(bool, L, R); 3778 // 3779 // where LR is the result of the usual arithmetic conversions 3780 // between types L and R. 3781 // Our candidates ignore the first parameter. 3782 for (unsigned Left = FirstPromotedArithmeticType; 3783 Left < LastPromotedArithmeticType; ++Left) { 3784 for (unsigned Right = FirstPromotedArithmeticType; 3785 Right < LastPromotedArithmeticType; ++Right) { 3786 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 3787 QualType Result 3788 = isComparison 3789 ? Context.BoolTy 3790 : Context.UsualArithmeticConversionsType(LandR[0], LandR[1]); 3791 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 3792 } 3793 } 3794 break; 3795 3796 case OO_Percent: 3797 BinaryAmp: 3798 case OO_Caret: 3799 case OO_Pipe: 3800 case OO_LessLess: 3801 case OO_GreaterGreater: 3802 // C++ [over.built]p17: 3803 // 3804 // For every pair of promoted integral types L and R, there 3805 // exist candidate operator functions of the form 3806 // 3807 // LR operator%(L, R); 3808 // LR operator&(L, R); 3809 // LR operator^(L, R); 3810 // LR operator|(L, R); 3811 // L operator<<(L, R); 3812 // L operator>>(L, R); 3813 // 3814 // where LR is the result of the usual arithmetic conversions 3815 // between types L and R. 3816 for (unsigned Left = FirstPromotedIntegralType; 3817 Left < LastPromotedIntegralType; ++Left) { 3818 for (unsigned Right = FirstPromotedIntegralType; 3819 Right < LastPromotedIntegralType; ++Right) { 3820 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 3821 QualType Result = (Op == OO_LessLess || Op == OO_GreaterGreater) 3822 ? LandR[0] 3823 : Context.UsualArithmeticConversionsType(LandR[0], LandR[1]); 3824 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 3825 } 3826 } 3827 break; 3828 3829 case OO_Equal: 3830 // C++ [over.built]p20: 3831 // 3832 // For every pair (T, VQ), where T is an enumeration or 3833 // pointer to member type and VQ is either volatile or 3834 // empty, there exist candidate operator functions of the form 3835 // 3836 // VQ T& operator=(VQ T&, T); 3837 for (BuiltinCandidateTypeSet::iterator 3838 Enum = CandidateTypes.enumeration_begin(), 3839 EnumEnd = CandidateTypes.enumeration_end(); 3840 Enum != EnumEnd; ++Enum) 3841 AddBuiltinAssignmentOperatorCandidates(*this, *Enum, Args, 2, 3842 CandidateSet); 3843 for (BuiltinCandidateTypeSet::iterator 3844 MemPtr = CandidateTypes.member_pointer_begin(), 3845 MemPtrEnd = CandidateTypes.member_pointer_end(); 3846 MemPtr != MemPtrEnd; ++MemPtr) 3847 AddBuiltinAssignmentOperatorCandidates(*this, *MemPtr, Args, 2, 3848 CandidateSet); 3849 // Fall through. 3850 3851 case OO_PlusEqual: 3852 case OO_MinusEqual: 3853 // C++ [over.built]p19: 3854 // 3855 // For every pair (T, VQ), where T is any type and VQ is either 3856 // volatile or empty, there exist candidate operator functions 3857 // of the form 3858 // 3859 // T*VQ& operator=(T*VQ&, T*); 3860 // 3861 // C++ [over.built]p21: 3862 // 3863 // For every pair (T, VQ), where T is a cv-qualified or 3864 // cv-unqualified object type and VQ is either volatile or 3865 // empty, there exist candidate operator functions of the form 3866 // 3867 // T*VQ& operator+=(T*VQ&, ptrdiff_t); 3868 // T*VQ& operator-=(T*VQ&, ptrdiff_t); 3869 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3870 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3871 QualType ParamTypes[2]; 3872 ParamTypes[1] = (Op == OO_Equal)? *Ptr : Context.getPointerDiffType(); 3873 3874 // non-volatile version 3875 ParamTypes[0] = Context.getLValueReferenceType(*Ptr); 3876 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3877 /*IsAssigmentOperator=*/Op == OO_Equal); 3878 3879 if (!Context.getCanonicalType(*Ptr).isVolatileQualified() && 3880 VisibleTypeConversionsQuals.hasVolatile()) { 3881 // volatile version 3882 ParamTypes[0] 3883 = Context.getLValueReferenceType(Context.getVolatileType(*Ptr)); 3884 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3885 /*IsAssigmentOperator=*/Op == OO_Equal); 3886 } 3887 } 3888 // Fall through. 3889 3890 case OO_StarEqual: 3891 case OO_SlashEqual: 3892 // C++ [over.built]p18: 3893 // 3894 // For every triple (L, VQ, R), where L is an arithmetic type, 3895 // VQ is either volatile or empty, and R is a promoted 3896 // arithmetic type, there exist candidate operator functions of 3897 // the form 3898 // 3899 // VQ L& operator=(VQ L&, R); 3900 // VQ L& operator*=(VQ L&, R); 3901 // VQ L& operator/=(VQ L&, R); 3902 // VQ L& operator+=(VQ L&, R); 3903 // VQ L& operator-=(VQ L&, R); 3904 for (unsigned Left = 0; Left < NumArithmeticTypes; ++Left) { 3905 for (unsigned Right = FirstPromotedArithmeticType; 3906 Right < LastPromotedArithmeticType; ++Right) { 3907 QualType ParamTypes[2]; 3908 ParamTypes[1] = ArithmeticTypes[Right]; 3909 3910 // Add this built-in operator as a candidate (VQ is empty). 3911 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 3912 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3913 /*IsAssigmentOperator=*/Op == OO_Equal); 3914 3915 // Add this built-in operator as a candidate (VQ is 'volatile'). 3916 if (VisibleTypeConversionsQuals.hasVolatile()) { 3917 ParamTypes[0] = Context.getVolatileType(ArithmeticTypes[Left]); 3918 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 3919 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3920 /*IsAssigmentOperator=*/Op == OO_Equal); 3921 } 3922 } 3923 } 3924 break; 3925 3926 case OO_PercentEqual: 3927 case OO_LessLessEqual: 3928 case OO_GreaterGreaterEqual: 3929 case OO_AmpEqual: 3930 case OO_CaretEqual: 3931 case OO_PipeEqual: 3932 // C++ [over.built]p22: 3933 // 3934 // For every triple (L, VQ, R), where L is an integral type, VQ 3935 // is either volatile or empty, and R is a promoted integral 3936 // type, there exist candidate operator functions of the form 3937 // 3938 // VQ L& operator%=(VQ L&, R); 3939 // VQ L& operator<<=(VQ L&, R); 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 for (unsigned Left = FirstIntegralType; Left < LastIntegralType; ++Left) { 3945 for (unsigned Right = FirstPromotedIntegralType; 3946 Right < LastPromotedIntegralType; ++Right) { 3947 QualType ParamTypes[2]; 3948 ParamTypes[1] = ArithmeticTypes[Right]; 3949 3950 // Add this built-in operator as a candidate (VQ is empty). 3951 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 3952 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 3953 if (VisibleTypeConversionsQuals.hasVolatile()) { 3954 // Add this built-in operator as a candidate (VQ is 'volatile'). 3955 ParamTypes[0] = ArithmeticTypes[Left]; 3956 ParamTypes[0] = Context.getVolatileType(ParamTypes[0]); 3957 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 3958 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 3959 } 3960 } 3961 } 3962 break; 3963 3964 case OO_Exclaim: { 3965 // C++ [over.operator]p23: 3966 // 3967 // There also exist candidate operator functions of the form 3968 // 3969 // bool operator!(bool); 3970 // bool operator&&(bool, bool); [BELOW] 3971 // bool operator||(bool, bool); [BELOW] 3972 QualType ParamTy = Context.BoolTy; 3973 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet, 3974 /*IsAssignmentOperator=*/false, 3975 /*NumContextualBoolArguments=*/1); 3976 break; 3977 } 3978 3979 case OO_AmpAmp: 3980 case OO_PipePipe: { 3981 // C++ [over.operator]p23: 3982 // 3983 // There also exist candidate operator functions of the form 3984 // 3985 // bool operator!(bool); [ABOVE] 3986 // bool operator&&(bool, bool); 3987 // bool operator||(bool, bool); 3988 QualType ParamTypes[2] = { Context.BoolTy, Context.BoolTy }; 3989 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet, 3990 /*IsAssignmentOperator=*/false, 3991 /*NumContextualBoolArguments=*/2); 3992 break; 3993 } 3994 3995 case OO_Subscript: 3996 // C++ [over.built]p13: 3997 // 3998 // For every cv-qualified or cv-unqualified object type T there 3999 // exist candidate operator functions of the form 4000 // 4001 // T* operator+(T*, ptrdiff_t); [ABOVE] 4002 // T& operator[](T*, ptrdiff_t); 4003 // T* operator-(T*, ptrdiff_t); [ABOVE] 4004 // T* operator+(ptrdiff_t, T*); [ABOVE] 4005 // T& operator[](ptrdiff_t, T*); 4006 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 4007 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4008 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 4009 QualType PointeeType = (*Ptr)->getAs<PointerType>()->getPointeeType(); 4010 QualType ResultTy = Context.getLValueReferenceType(PointeeType); 4011 4012 // T& operator[](T*, ptrdiff_t) 4013 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 4014 4015 // T& operator[](ptrdiff_t, T*); 4016 ParamTypes[0] = ParamTypes[1]; 4017 ParamTypes[1] = *Ptr; 4018 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 4019 } 4020 break; 4021 4022 case OO_ArrowStar: 4023 // C++ [over.built]p11: 4024 // For every quintuple (C1, C2, T, CV1, CV2), where C2 is a class type, 4025 // C1 is the same type as C2 or is a derived class of C2, T is an object 4026 // type or a function type, and CV1 and CV2 are cv-qualifier-seqs, 4027 // there exist candidate operator functions of the form 4028 // CV12 T& operator->*(CV1 C1*, CV2 T C2::*); 4029 // where CV12 is the union of CV1 and CV2. 4030 { 4031 for (BuiltinCandidateTypeSet::iterator Ptr = 4032 CandidateTypes.pointer_begin(); 4033 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4034 QualType C1Ty = (*Ptr); 4035 QualType C1; 4036 QualifierCollector Q1; 4037 if (const PointerType *PointerTy = C1Ty->getAs<PointerType>()) { 4038 C1 = QualType(Q1.strip(PointerTy->getPointeeType()), 0); 4039 if (!isa<RecordType>(C1)) 4040 continue; 4041 // heuristic to reduce number of builtin candidates in the set. 4042 // Add volatile/restrict version only if there are conversions to a 4043 // volatile/restrict type. 4044 if (!VisibleTypeConversionsQuals.hasVolatile() && Q1.hasVolatile()) 4045 continue; 4046 if (!VisibleTypeConversionsQuals.hasRestrict() && Q1.hasRestrict()) 4047 continue; 4048 } 4049 for (BuiltinCandidateTypeSet::iterator 4050 MemPtr = CandidateTypes.member_pointer_begin(), 4051 MemPtrEnd = CandidateTypes.member_pointer_end(); 4052 MemPtr != MemPtrEnd; ++MemPtr) { 4053 const MemberPointerType *mptr = cast<MemberPointerType>(*MemPtr); 4054 QualType C2 = QualType(mptr->getClass(), 0); 4055 C2 = C2.getUnqualifiedType(); 4056 if (C1 != C2 && !IsDerivedFrom(C1, C2)) 4057 break; 4058 QualType ParamTypes[2] = { *Ptr, *MemPtr }; 4059 // build CV12 T& 4060 QualType T = mptr->getPointeeType(); 4061 if (!VisibleTypeConversionsQuals.hasVolatile() && 4062 T.isVolatileQualified()) 4063 continue; 4064 if (!VisibleTypeConversionsQuals.hasRestrict() && 4065 T.isRestrictQualified()) 4066 continue; 4067 T = Q1.apply(T); 4068 QualType ResultTy = Context.getLValueReferenceType(T); 4069 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 4070 } 4071 } 4072 } 4073 break; 4074 4075 case OO_Conditional: 4076 // Note that we don't consider the first argument, since it has been 4077 // contextually converted to bool long ago. The candidates below are 4078 // therefore added as binary. 4079 // 4080 // C++ [over.built]p24: 4081 // For every type T, where T is a pointer or pointer-to-member type, 4082 // there exist candidate operator functions of the form 4083 // 4084 // T operator?(bool, T, T); 4085 // 4086 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(), 4087 E = CandidateTypes.pointer_end(); Ptr != E; ++Ptr) { 4088 QualType ParamTypes[2] = { *Ptr, *Ptr }; 4089 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 4090 } 4091 for (BuiltinCandidateTypeSet::iterator Ptr = 4092 CandidateTypes.member_pointer_begin(), 4093 E = CandidateTypes.member_pointer_end(); Ptr != E; ++Ptr) { 4094 QualType ParamTypes[2] = { *Ptr, *Ptr }; 4095 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 4096 } 4097 goto Conditional; 4098 } 4099} 4100 4101/// \brief Add function candidates found via argument-dependent lookup 4102/// to the set of overloading candidates. 4103/// 4104/// This routine performs argument-dependent name lookup based on the 4105/// given function name (which may also be an operator name) and adds 4106/// all of the overload candidates found by ADL to the overload 4107/// candidate set (C++ [basic.lookup.argdep]). 4108void 4109Sema::AddArgumentDependentLookupCandidates(DeclarationName Name, 4110 Expr **Args, unsigned NumArgs, 4111 const TemplateArgumentListInfo *ExplicitTemplateArgs, 4112 OverloadCandidateSet& CandidateSet, 4113 bool PartialOverloading) { 4114 FunctionSet Functions; 4115 4116 // FIXME: Should we be trafficking in canonical function decls throughout? 4117 4118 // Record all of the function candidates that we've already 4119 // added to the overload set, so that we don't add those same 4120 // candidates a second time. 4121 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 4122 CandEnd = CandidateSet.end(); 4123 Cand != CandEnd; ++Cand) 4124 if (Cand->Function) { 4125 Functions.insert(Cand->Function); 4126 if (FunctionTemplateDecl *FunTmpl = Cand->Function->getPrimaryTemplate()) 4127 Functions.insert(FunTmpl); 4128 } 4129 4130 // FIXME: Pass in the explicit template arguments? 4131 ArgumentDependentLookup(Name, /*Operator*/false, Args, NumArgs, Functions); 4132 4133 // Erase all of the candidates we already knew about. 4134 // FIXME: This is suboptimal. Is there a better way? 4135 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 4136 CandEnd = CandidateSet.end(); 4137 Cand != CandEnd; ++Cand) 4138 if (Cand->Function) { 4139 Functions.erase(Cand->Function); 4140 if (FunctionTemplateDecl *FunTmpl = Cand->Function->getPrimaryTemplate()) 4141 Functions.erase(FunTmpl); 4142 } 4143 4144 // For each of the ADL candidates we found, add it to the overload 4145 // set. 4146 for (FunctionSet::iterator Func = Functions.begin(), 4147 FuncEnd = Functions.end(); 4148 Func != FuncEnd; ++Func) { 4149 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*Func)) { 4150 if (ExplicitTemplateArgs) 4151 continue; 4152 4153 AddOverloadCandidate(FD, Args, NumArgs, CandidateSet, 4154 false, false, PartialOverloading); 4155 } else 4156 AddTemplateOverloadCandidate(cast<FunctionTemplateDecl>(*Func), 4157 ExplicitTemplateArgs, 4158 Args, NumArgs, CandidateSet); 4159 } 4160} 4161 4162/// isBetterOverloadCandidate - Determines whether the first overload 4163/// candidate is a better candidate than the second (C++ 13.3.3p1). 4164bool 4165Sema::isBetterOverloadCandidate(const OverloadCandidate& Cand1, 4166 const OverloadCandidate& Cand2) { 4167 // Define viable functions to be better candidates than non-viable 4168 // functions. 4169 if (!Cand2.Viable) 4170 return Cand1.Viable; 4171 else if (!Cand1.Viable) 4172 return false; 4173 4174 // C++ [over.match.best]p1: 4175 // 4176 // -- if F is a static member function, ICS1(F) is defined such 4177 // that ICS1(F) is neither better nor worse than ICS1(G) for 4178 // any function G, and, symmetrically, ICS1(G) is neither 4179 // better nor worse than ICS1(F). 4180 unsigned StartArg = 0; 4181 if (Cand1.IgnoreObjectArgument || Cand2.IgnoreObjectArgument) 4182 StartArg = 1; 4183 4184 // C++ [over.match.best]p1: 4185 // A viable function F1 is defined to be a better function than another 4186 // viable function F2 if for all arguments i, ICSi(F1) is not a worse 4187 // conversion sequence than ICSi(F2), and then... 4188 unsigned NumArgs = Cand1.Conversions.size(); 4189 assert(Cand2.Conversions.size() == NumArgs && "Overload candidate mismatch"); 4190 bool HasBetterConversion = false; 4191 for (unsigned ArgIdx = StartArg; ArgIdx < NumArgs; ++ArgIdx) { 4192 switch (CompareImplicitConversionSequences(Cand1.Conversions[ArgIdx], 4193 Cand2.Conversions[ArgIdx])) { 4194 case ImplicitConversionSequence::Better: 4195 // Cand1 has a better conversion sequence. 4196 HasBetterConversion = true; 4197 break; 4198 4199 case ImplicitConversionSequence::Worse: 4200 // Cand1 can't be better than Cand2. 4201 return false; 4202 4203 case ImplicitConversionSequence::Indistinguishable: 4204 // Do nothing. 4205 break; 4206 } 4207 } 4208 4209 // -- for some argument j, ICSj(F1) is a better conversion sequence than 4210 // ICSj(F2), or, if not that, 4211 if (HasBetterConversion) 4212 return true; 4213 4214 // - F1 is a non-template function and F2 is a function template 4215 // specialization, or, if not that, 4216 if (Cand1.Function && !Cand1.Function->getPrimaryTemplate() && 4217 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 4218 return true; 4219 4220 // -- F1 and F2 are function template specializations, and the function 4221 // template for F1 is more specialized than the template for F2 4222 // according to the partial ordering rules described in 14.5.5.2, or, 4223 // if not that, 4224 if (Cand1.Function && Cand1.Function->getPrimaryTemplate() && 4225 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 4226 if (FunctionTemplateDecl *BetterTemplate 4227 = getMoreSpecializedTemplate(Cand1.Function->getPrimaryTemplate(), 4228 Cand2.Function->getPrimaryTemplate(), 4229 isa<CXXConversionDecl>(Cand1.Function)? TPOC_Conversion 4230 : TPOC_Call)) 4231 return BetterTemplate == Cand1.Function->getPrimaryTemplate(); 4232 4233 // -- the context is an initialization by user-defined conversion 4234 // (see 8.5, 13.3.1.5) and the standard conversion sequence 4235 // from the return type of F1 to the destination type (i.e., 4236 // the type of the entity being initialized) is a better 4237 // conversion sequence than the standard conversion sequence 4238 // from the return type of F2 to the destination type. 4239 if (Cand1.Function && Cand2.Function && 4240 isa<CXXConversionDecl>(Cand1.Function) && 4241 isa<CXXConversionDecl>(Cand2.Function)) { 4242 switch (CompareStandardConversionSequences(Cand1.FinalConversion, 4243 Cand2.FinalConversion)) { 4244 case ImplicitConversionSequence::Better: 4245 // Cand1 has a better conversion sequence. 4246 return true; 4247 4248 case ImplicitConversionSequence::Worse: 4249 // Cand1 can't be better than Cand2. 4250 return false; 4251 4252 case ImplicitConversionSequence::Indistinguishable: 4253 // Do nothing 4254 break; 4255 } 4256 } 4257 4258 return false; 4259} 4260 4261/// \brief Computes the best viable function (C++ 13.3.3) 4262/// within an overload candidate set. 4263/// 4264/// \param CandidateSet the set of candidate functions. 4265/// 4266/// \param Loc the location of the function name (or operator symbol) for 4267/// which overload resolution occurs. 4268/// 4269/// \param Best f overload resolution was successful or found a deleted 4270/// function, Best points to the candidate function found. 4271/// 4272/// \returns The result of overload resolution. 4273OverloadingResult Sema::BestViableFunction(OverloadCandidateSet& CandidateSet, 4274 SourceLocation Loc, 4275 OverloadCandidateSet::iterator& Best) { 4276 // Find the best viable function. 4277 Best = CandidateSet.end(); 4278 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 4279 Cand != CandidateSet.end(); ++Cand) { 4280 if (Cand->Viable) { 4281 if (Best == CandidateSet.end() || isBetterOverloadCandidate(*Cand, *Best)) 4282 Best = Cand; 4283 } 4284 } 4285 4286 // If we didn't find any viable functions, abort. 4287 if (Best == CandidateSet.end()) 4288 return OR_No_Viable_Function; 4289 4290 // Make sure that this function is better than every other viable 4291 // function. If not, we have an ambiguity. 4292 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 4293 Cand != CandidateSet.end(); ++Cand) { 4294 if (Cand->Viable && 4295 Cand != Best && 4296 !isBetterOverloadCandidate(*Best, *Cand)) { 4297 Best = CandidateSet.end(); 4298 return OR_Ambiguous; 4299 } 4300 } 4301 4302 // Best is the best viable function. 4303 if (Best->Function && 4304 (Best->Function->isDeleted() || 4305 Best->Function->getAttr<UnavailableAttr>())) 4306 return OR_Deleted; 4307 4308 // C++ [basic.def.odr]p2: 4309 // An overloaded function is used if it is selected by overload resolution 4310 // when referred to from a potentially-evaluated expression. [Note: this 4311 // covers calls to named functions (5.2.2), operator overloading 4312 // (clause 13), user-defined conversions (12.3.2), allocation function for 4313 // placement new (5.3.4), as well as non-default initialization (8.5). 4314 if (Best->Function) 4315 MarkDeclarationReferenced(Loc, Best->Function); 4316 return OR_Success; 4317} 4318 4319namespace { 4320 4321enum OverloadCandidateKind { 4322 oc_function, 4323 oc_method, 4324 oc_constructor, 4325 oc_function_template, 4326 oc_method_template, 4327 oc_constructor_template, 4328 oc_implicit_default_constructor, 4329 oc_implicit_copy_constructor, 4330 oc_implicit_copy_assignment 4331}; 4332 4333OverloadCandidateKind ClassifyOverloadCandidate(Sema &S, 4334 FunctionDecl *Fn, 4335 std::string &Description) { 4336 bool isTemplate = false; 4337 4338 if (FunctionTemplateDecl *FunTmpl = Fn->getPrimaryTemplate()) { 4339 isTemplate = true; 4340 Description = S.getTemplateArgumentBindingsText( 4341 FunTmpl->getTemplateParameters(), *Fn->getTemplateSpecializationArgs()); 4342 } 4343 4344 if (CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(Fn)) { 4345 if (!Ctor->isImplicit()) 4346 return isTemplate ? oc_constructor_template : oc_constructor; 4347 4348 return Ctor->isCopyConstructor() ? oc_implicit_copy_constructor 4349 : oc_implicit_default_constructor; 4350 } 4351 4352 if (CXXMethodDecl *Meth = dyn_cast<CXXMethodDecl>(Fn)) { 4353 // This actually gets spelled 'candidate function' for now, but 4354 // it doesn't hurt to split it out. 4355 if (!Meth->isImplicit()) 4356 return isTemplate ? oc_method_template : oc_method; 4357 4358 assert(Meth->isCopyAssignment() 4359 && "implicit method is not copy assignment operator?"); 4360 return oc_implicit_copy_assignment; 4361 } 4362 4363 return isTemplate ? oc_function_template : oc_function; 4364} 4365 4366} // end anonymous namespace 4367 4368// Notes the location of an overload candidate. 4369void Sema::NoteOverloadCandidate(FunctionDecl *Fn) { 4370 std::string FnDesc; 4371 OverloadCandidateKind K = ClassifyOverloadCandidate(*this, Fn, FnDesc); 4372 Diag(Fn->getLocation(), diag::note_ovl_candidate) 4373 << (unsigned) K << FnDesc; 4374} 4375 4376/// Diagnoses an ambiguous conversion. The partial diagnostic is the 4377/// "lead" diagnostic; it will be given two arguments, the source and 4378/// target types of the conversion. 4379void Sema::DiagnoseAmbiguousConversion(const ImplicitConversionSequence &ICS, 4380 SourceLocation CaretLoc, 4381 const PartialDiagnostic &PDiag) { 4382 Diag(CaretLoc, PDiag) 4383 << ICS.Ambiguous.getFromType() << ICS.Ambiguous.getToType(); 4384 for (AmbiguousConversionSequence::const_iterator 4385 I = ICS.Ambiguous.begin(), E = ICS.Ambiguous.end(); I != E; ++I) { 4386 NoteOverloadCandidate(*I); 4387 } 4388} 4389 4390namespace { 4391 4392void DiagnoseBadConversion(Sema &S, OverloadCandidate *Cand, unsigned I) { 4393 const ImplicitConversionSequence &Conv = Cand->Conversions[I]; 4394 assert(Conv.isBad()); 4395 assert(Cand->Function && "for now, candidate must be a function"); 4396 FunctionDecl *Fn = Cand->Function; 4397 4398 // There's a conversion slot for the object argument if this is a 4399 // non-constructor method. Note that 'I' corresponds the 4400 // conversion-slot index. 4401 bool isObjectArgument = false; 4402 if (isa<CXXMethodDecl>(Fn) && !isa<CXXConstructorDecl>(Fn)) { 4403 if (I == 0) 4404 isObjectArgument = true; 4405 else 4406 I--; 4407 } 4408 4409 std::string FnDesc; 4410 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, FnDesc); 4411 4412 Expr *FromExpr = Conv.Bad.FromExpr; 4413 QualType FromTy = Conv.Bad.getFromType(); 4414 QualType ToTy = Conv.Bad.getToType(); 4415 4416 // Do some hand-waving analysis to see if the non-viability is due to a 4417 CanQualType CFromTy = S.Context.getCanonicalType(FromTy); 4418 CanQualType CToTy = S.Context.getCanonicalType(ToTy); 4419 if (CanQual<ReferenceType> RT = CToTy->getAs<ReferenceType>()) 4420 CToTy = RT->getPointeeType(); 4421 else { 4422 // TODO: detect and diagnose the full richness of const mismatches. 4423 if (CanQual<PointerType> FromPT = CFromTy->getAs<PointerType>()) 4424 if (CanQual<PointerType> ToPT = CToTy->getAs<PointerType>()) 4425 CFromTy = FromPT->getPointeeType(), CToTy = ToPT->getPointeeType(); 4426 } 4427 4428 if (CToTy.getUnqualifiedType() == CFromTy.getUnqualifiedType() && 4429 !CToTy.isAtLeastAsQualifiedAs(CFromTy)) { 4430 // It is dumb that we have to do this here. 4431 while (isa<ArrayType>(CFromTy)) 4432 CFromTy = CFromTy->getAs<ArrayType>()->getElementType(); 4433 while (isa<ArrayType>(CToTy)) 4434 CToTy = CFromTy->getAs<ArrayType>()->getElementType(); 4435 4436 Qualifiers FromQs = CFromTy.getQualifiers(); 4437 Qualifiers ToQs = CToTy.getQualifiers(); 4438 4439 if (FromQs.getAddressSpace() != ToQs.getAddressSpace()) { 4440 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_addrspace) 4441 << (unsigned) FnKind << FnDesc 4442 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 4443 << FromTy 4444 << FromQs.getAddressSpace() << ToQs.getAddressSpace() 4445 << (unsigned) isObjectArgument << I+1; 4446 return; 4447 } 4448 4449 unsigned CVR = FromQs.getCVRQualifiers() & ~ToQs.getCVRQualifiers(); 4450 assert(CVR && "unexpected qualifiers mismatch"); 4451 4452 if (isObjectArgument) { 4453 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr_this) 4454 << (unsigned) FnKind << FnDesc 4455 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 4456 << FromTy << (CVR - 1); 4457 } else { 4458 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr) 4459 << (unsigned) FnKind << FnDesc 4460 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 4461 << FromTy << (CVR - 1) << I+1; 4462 } 4463 return; 4464 } 4465 4466 // TODO: specialize more based on the kind of mismatch 4467 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_conv) 4468 << (unsigned) FnKind << FnDesc 4469 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 4470 << FromTy << ToTy << (unsigned) isObjectArgument << I+1; 4471} 4472 4473void DiagnoseArityMismatch(Sema &S, OverloadCandidate *Cand, 4474 unsigned NumFormalArgs) { 4475 // TODO: treat calls to a missing default constructor as a special case 4476 4477 FunctionDecl *Fn = Cand->Function; 4478 const FunctionProtoType *FnTy = Fn->getType()->getAs<FunctionProtoType>(); 4479 4480 unsigned MinParams = Fn->getMinRequiredArguments(); 4481 4482 // at least / at most / exactly 4483 unsigned mode, modeCount; 4484 if (NumFormalArgs < MinParams) { 4485 assert(Cand->FailureKind == ovl_fail_too_few_arguments); 4486 if (MinParams != FnTy->getNumArgs() || FnTy->isVariadic()) 4487 mode = 0; // "at least" 4488 else 4489 mode = 2; // "exactly" 4490 modeCount = MinParams; 4491 } else { 4492 assert(Cand->FailureKind == ovl_fail_too_many_arguments); 4493 if (MinParams != FnTy->getNumArgs()) 4494 mode = 1; // "at most" 4495 else 4496 mode = 2; // "exactly" 4497 modeCount = FnTy->getNumArgs(); 4498 } 4499 4500 std::string Description; 4501 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, Description); 4502 4503 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_arity) 4504 << (unsigned) FnKind << Description << mode << modeCount << NumFormalArgs; 4505} 4506 4507void NoteFunctionCandidate(Sema &S, OverloadCandidate *Cand, 4508 Expr **Args, unsigned NumArgs) { 4509 FunctionDecl *Fn = Cand->Function; 4510 4511 // Note deleted candidates, but only if they're viable. 4512 if (Cand->Viable && (Fn->isDeleted() || Fn->hasAttr<UnavailableAttr>())) { 4513 std::string FnDesc; 4514 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, FnDesc); 4515 4516 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_deleted) 4517 << FnKind << FnDesc << Fn->isDeleted(); 4518 return; 4519 } 4520 4521 // We don't really have anything else to say about viable candidates. 4522 if (Cand->Viable) { 4523 S.NoteOverloadCandidate(Fn); 4524 return; 4525 } 4526 4527 switch (Cand->FailureKind) { 4528 case ovl_fail_too_many_arguments: 4529 case ovl_fail_too_few_arguments: 4530 return DiagnoseArityMismatch(S, Cand, NumArgs); 4531 4532 case ovl_fail_bad_deduction: 4533 return S.NoteOverloadCandidate(Fn); 4534 4535 case ovl_fail_bad_conversion: 4536 for (unsigned I = 0, N = Cand->Conversions.size(); I != N; ++I) 4537 if (Cand->Conversions[I].isBad()) 4538 return DiagnoseBadConversion(S, Cand, I); 4539 4540 // FIXME: this currently happens when we're called from SemaInit 4541 // when user-conversion overload fails. Figure out how to handle 4542 // those conditions and diagnose them well. 4543 return S.NoteOverloadCandidate(Fn); 4544 } 4545} 4546 4547void NoteSurrogateCandidate(Sema &S, OverloadCandidate *Cand) { 4548 // Desugar the type of the surrogate down to a function type, 4549 // retaining as many typedefs as possible while still showing 4550 // the function type (and, therefore, its parameter types). 4551 QualType FnType = Cand->Surrogate->getConversionType(); 4552 bool isLValueReference = false; 4553 bool isRValueReference = false; 4554 bool isPointer = false; 4555 if (const LValueReferenceType *FnTypeRef = 4556 FnType->getAs<LValueReferenceType>()) { 4557 FnType = FnTypeRef->getPointeeType(); 4558 isLValueReference = true; 4559 } else if (const RValueReferenceType *FnTypeRef = 4560 FnType->getAs<RValueReferenceType>()) { 4561 FnType = FnTypeRef->getPointeeType(); 4562 isRValueReference = true; 4563 } 4564 if (const PointerType *FnTypePtr = FnType->getAs<PointerType>()) { 4565 FnType = FnTypePtr->getPointeeType(); 4566 isPointer = true; 4567 } 4568 // Desugar down to a function type. 4569 FnType = QualType(FnType->getAs<FunctionType>(), 0); 4570 // Reconstruct the pointer/reference as appropriate. 4571 if (isPointer) FnType = S.Context.getPointerType(FnType); 4572 if (isRValueReference) FnType = S.Context.getRValueReferenceType(FnType); 4573 if (isLValueReference) FnType = S.Context.getLValueReferenceType(FnType); 4574 4575 S.Diag(Cand->Surrogate->getLocation(), diag::note_ovl_surrogate_cand) 4576 << FnType; 4577} 4578 4579void NoteBuiltinOperatorCandidate(Sema &S, 4580 const char *Opc, 4581 SourceLocation OpLoc, 4582 OverloadCandidate *Cand) { 4583 assert(Cand->Conversions.size() <= 2 && "builtin operator is not binary"); 4584 std::string TypeStr("operator"); 4585 TypeStr += Opc; 4586 TypeStr += "("; 4587 TypeStr += Cand->BuiltinTypes.ParamTypes[0].getAsString(); 4588 if (Cand->Conversions.size() == 1) { 4589 TypeStr += ")"; 4590 S.Diag(OpLoc, diag::note_ovl_builtin_unary_candidate) << TypeStr; 4591 } else { 4592 TypeStr += ", "; 4593 TypeStr += Cand->BuiltinTypes.ParamTypes[1].getAsString(); 4594 TypeStr += ")"; 4595 S.Diag(OpLoc, diag::note_ovl_builtin_binary_candidate) << TypeStr; 4596 } 4597} 4598 4599void NoteAmbiguousUserConversions(Sema &S, SourceLocation OpLoc, 4600 OverloadCandidate *Cand) { 4601 unsigned NoOperands = Cand->Conversions.size(); 4602 for (unsigned ArgIdx = 0; ArgIdx < NoOperands; ++ArgIdx) { 4603 const ImplicitConversionSequence &ICS = Cand->Conversions[ArgIdx]; 4604 if (ICS.isBad()) break; // all meaningless after first invalid 4605 if (!ICS.isAmbiguous()) continue; 4606 4607 S.DiagnoseAmbiguousConversion(ICS, OpLoc, 4608 PDiag(diag::note_ambiguous_type_conversion)); 4609 } 4610} 4611 4612SourceLocation GetLocationForCandidate(const OverloadCandidate *Cand) { 4613 if (Cand->Function) 4614 return Cand->Function->getLocation(); 4615 if (Cand->IsSurrogate) 4616 return Cand->Surrogate->getLocation(); 4617 return SourceLocation(); 4618} 4619 4620struct CompareOverloadCandidatesForDisplay { 4621 Sema &S; 4622 CompareOverloadCandidatesForDisplay(Sema &S) : S(S) {} 4623 4624 bool operator()(const OverloadCandidate *L, 4625 const OverloadCandidate *R) { 4626 // Fast-path this check. 4627 if (L == R) return false; 4628 4629 // Order first by viability. 4630 if (L->Viable) { 4631 if (!R->Viable) return true; 4632 4633 // TODO: introduce a tri-valued comparison for overload 4634 // candidates. Would be more worthwhile if we had a sort 4635 // that could exploit it. 4636 if (S.isBetterOverloadCandidate(*L, *R)) return true; 4637 if (S.isBetterOverloadCandidate(*R, *L)) return false; 4638 } else if (R->Viable) 4639 return false; 4640 4641 assert(L->Viable == R->Viable); 4642 4643 // Criteria by which we can sort non-viable candidates: 4644 if (!L->Viable) { 4645 // 1. Arity mismatches come after other candidates. 4646 if (L->FailureKind == ovl_fail_too_many_arguments || 4647 L->FailureKind == ovl_fail_too_few_arguments) 4648 return false; 4649 if (R->FailureKind == ovl_fail_too_many_arguments || 4650 R->FailureKind == ovl_fail_too_few_arguments) 4651 return true; 4652 4653 // TODO: others? 4654 } 4655 4656 // Sort everything else by location. 4657 SourceLocation LLoc = GetLocationForCandidate(L); 4658 SourceLocation RLoc = GetLocationForCandidate(R); 4659 4660 // Put candidates without locations (e.g. builtins) at the end. 4661 if (LLoc.isInvalid()) return false; 4662 if (RLoc.isInvalid()) return true; 4663 4664 return S.SourceMgr.isBeforeInTranslationUnit(LLoc, RLoc); 4665 } 4666}; 4667 4668} // end anonymous namespace 4669 4670/// PrintOverloadCandidates - When overload resolution fails, prints 4671/// diagnostic messages containing the candidates in the candidate 4672/// set. 4673void 4674Sema::PrintOverloadCandidates(OverloadCandidateSet& CandidateSet, 4675 OverloadCandidateDisplayKind OCD, 4676 Expr **Args, unsigned NumArgs, 4677 const char *Opc, 4678 SourceLocation OpLoc) { 4679 // Sort the candidates by viability and position. Sorting directly would 4680 // be prohibitive, so we make a set of pointers and sort those. 4681 llvm::SmallVector<OverloadCandidate*, 32> Cands; 4682 if (OCD == OCD_AllCandidates) Cands.reserve(CandidateSet.size()); 4683 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 4684 LastCand = CandidateSet.end(); 4685 Cand != LastCand; ++Cand) 4686 if (Cand->Viable || OCD == OCD_AllCandidates) 4687 Cands.push_back(Cand); 4688 std::sort(Cands.begin(), Cands.end(), 4689 CompareOverloadCandidatesForDisplay(*this)); 4690 4691 bool ReportedAmbiguousConversions = false; 4692 4693 llvm::SmallVectorImpl<OverloadCandidate*>::iterator I, E; 4694 for (I = Cands.begin(), E = Cands.end(); I != E; ++I) { 4695 OverloadCandidate *Cand = *I; 4696 4697 if (Cand->Function) 4698 NoteFunctionCandidate(*this, Cand, Args, NumArgs); 4699 else if (Cand->IsSurrogate) 4700 NoteSurrogateCandidate(*this, Cand); 4701 4702 // This a builtin candidate. We do not, in general, want to list 4703 // every possible builtin candidate. 4704 else if (Cand->Viable) { 4705 // Generally we only see ambiguities including viable builtin 4706 // operators if overload resolution got screwed up by an 4707 // ambiguous user-defined conversion. 4708 // 4709 // FIXME: It's quite possible for different conversions to see 4710 // different ambiguities, though. 4711 if (!ReportedAmbiguousConversions) { 4712 NoteAmbiguousUserConversions(*this, OpLoc, Cand); 4713 ReportedAmbiguousConversions = true; 4714 } 4715 4716 // If this is a viable builtin, print it. 4717 NoteBuiltinOperatorCandidate(*this, Opc, OpLoc, Cand); 4718 } 4719 } 4720} 4721 4722/// ResolveAddressOfOverloadedFunction - Try to resolve the address of 4723/// an overloaded function (C++ [over.over]), where @p From is an 4724/// expression with overloaded function type and @p ToType is the type 4725/// we're trying to resolve to. For example: 4726/// 4727/// @code 4728/// int f(double); 4729/// int f(int); 4730/// 4731/// int (*pfd)(double) = f; // selects f(double) 4732/// @endcode 4733/// 4734/// This routine returns the resulting FunctionDecl if it could be 4735/// resolved, and NULL otherwise. When @p Complain is true, this 4736/// routine will emit diagnostics if there is an error. 4737FunctionDecl * 4738Sema::ResolveAddressOfOverloadedFunction(Expr *From, QualType ToType, 4739 bool Complain) { 4740 QualType FunctionType = ToType; 4741 bool IsMember = false; 4742 if (const PointerType *ToTypePtr = ToType->getAs<PointerType>()) 4743 FunctionType = ToTypePtr->getPointeeType(); 4744 else if (const ReferenceType *ToTypeRef = ToType->getAs<ReferenceType>()) 4745 FunctionType = ToTypeRef->getPointeeType(); 4746 else if (const MemberPointerType *MemTypePtr = 4747 ToType->getAs<MemberPointerType>()) { 4748 FunctionType = MemTypePtr->getPointeeType(); 4749 IsMember = true; 4750 } 4751 4752 // We only look at pointers or references to functions. 4753 FunctionType = Context.getCanonicalType(FunctionType).getUnqualifiedType(); 4754 if (!FunctionType->isFunctionType()) 4755 return 0; 4756 4757 // Find the actual overloaded function declaration. 4758 4759 // C++ [over.over]p1: 4760 // [...] [Note: any redundant set of parentheses surrounding the 4761 // overloaded function name is ignored (5.1). ] 4762 Expr *OvlExpr = From->IgnoreParens(); 4763 4764 // C++ [over.over]p1: 4765 // [...] The overloaded function name can be preceded by the & 4766 // operator. 4767 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(OvlExpr)) { 4768 if (UnOp->getOpcode() == UnaryOperator::AddrOf) 4769 OvlExpr = UnOp->getSubExpr()->IgnoreParens(); 4770 } 4771 4772 bool HasExplicitTemplateArgs = false; 4773 TemplateArgumentListInfo ExplicitTemplateArgs; 4774 4775 llvm::SmallVector<NamedDecl*,8> Fns; 4776 4777 // Look into the overloaded expression. 4778 if (UnresolvedLookupExpr *UL 4779 = dyn_cast<UnresolvedLookupExpr>(OvlExpr)) { 4780 Fns.append(UL->decls_begin(), UL->decls_end()); 4781 if (UL->hasExplicitTemplateArgs()) { 4782 HasExplicitTemplateArgs = true; 4783 UL->copyTemplateArgumentsInto(ExplicitTemplateArgs); 4784 } 4785 } else if (UnresolvedMemberExpr *ME 4786 = dyn_cast<UnresolvedMemberExpr>(OvlExpr)) { 4787 Fns.append(ME->decls_begin(), ME->decls_end()); 4788 if (ME->hasExplicitTemplateArgs()) { 4789 HasExplicitTemplateArgs = true; 4790 ME->copyTemplateArgumentsInto(ExplicitTemplateArgs); 4791 } 4792 } 4793 4794 // If we didn't actually find anything, we're done. 4795 if (Fns.empty()) 4796 return 0; 4797 4798 // Look through all of the overloaded functions, searching for one 4799 // whose type matches exactly. 4800 llvm::SmallPtrSet<FunctionDecl *, 4> Matches; 4801 bool FoundNonTemplateFunction = false; 4802 for (llvm::SmallVectorImpl<NamedDecl*>::iterator I = Fns.begin(), 4803 E = Fns.end(); I != E; ++I) { 4804 // Look through any using declarations to find the underlying function. 4805 NamedDecl *Fn = (*I)->getUnderlyingDecl(); 4806 4807 // C++ [over.over]p3: 4808 // Non-member functions and static member functions match 4809 // targets of type "pointer-to-function" or "reference-to-function." 4810 // Nonstatic member functions match targets of 4811 // type "pointer-to-member-function." 4812 // Note that according to DR 247, the containing class does not matter. 4813 4814 if (FunctionTemplateDecl *FunctionTemplate 4815 = dyn_cast<FunctionTemplateDecl>(Fn)) { 4816 if (CXXMethodDecl *Method 4817 = dyn_cast<CXXMethodDecl>(FunctionTemplate->getTemplatedDecl())) { 4818 // Skip non-static function templates when converting to pointer, and 4819 // static when converting to member pointer. 4820 if (Method->isStatic() == IsMember) 4821 continue; 4822 } else if (IsMember) 4823 continue; 4824 4825 // C++ [over.over]p2: 4826 // If the name is a function template, template argument deduction is 4827 // done (14.8.2.2), and if the argument deduction succeeds, the 4828 // resulting template argument list is used to generate a single 4829 // function template specialization, which is added to the set of 4830 // overloaded functions considered. 4831 // FIXME: We don't really want to build the specialization here, do we? 4832 FunctionDecl *Specialization = 0; 4833 TemplateDeductionInfo Info(Context); 4834 if (TemplateDeductionResult Result 4835 = DeduceTemplateArguments(FunctionTemplate, 4836 (HasExplicitTemplateArgs ? &ExplicitTemplateArgs : 0), 4837 FunctionType, Specialization, Info)) { 4838 // FIXME: make a note of the failed deduction for diagnostics. 4839 (void)Result; 4840 } else { 4841 // FIXME: If the match isn't exact, shouldn't we just drop this as 4842 // a candidate? Find a testcase before changing the code. 4843 assert(FunctionType 4844 == Context.getCanonicalType(Specialization->getType())); 4845 Matches.insert( 4846 cast<FunctionDecl>(Specialization->getCanonicalDecl())); 4847 } 4848 4849 continue; 4850 } 4851 4852 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 4853 // Skip non-static functions when converting to pointer, and static 4854 // when converting to member pointer. 4855 if (Method->isStatic() == IsMember) 4856 continue; 4857 4858 // If we have explicit template arguments, skip non-templates. 4859 if (HasExplicitTemplateArgs) 4860 continue; 4861 } else if (IsMember) 4862 continue; 4863 4864 if (FunctionDecl *FunDecl = dyn_cast<FunctionDecl>(Fn)) { 4865 QualType ResultTy; 4866 if (Context.hasSameUnqualifiedType(FunctionType, FunDecl->getType()) || 4867 IsNoReturnConversion(Context, FunDecl->getType(), FunctionType, 4868 ResultTy)) { 4869 Matches.insert(cast<FunctionDecl>(FunDecl->getCanonicalDecl())); 4870 FoundNonTemplateFunction = true; 4871 } 4872 } 4873 } 4874 4875 // If there were 0 or 1 matches, we're done. 4876 if (Matches.empty()) 4877 return 0; 4878 else if (Matches.size() == 1) { 4879 FunctionDecl *Result = *Matches.begin(); 4880 MarkDeclarationReferenced(From->getLocStart(), Result); 4881 return Result; 4882 } 4883 4884 // C++ [over.over]p4: 4885 // If more than one function is selected, [...] 4886 typedef llvm::SmallPtrSet<FunctionDecl *, 4>::iterator MatchIter; 4887 if (!FoundNonTemplateFunction) { 4888 // [...] and any given function template specialization F1 is 4889 // eliminated if the set contains a second function template 4890 // specialization whose function template is more specialized 4891 // than the function template of F1 according to the partial 4892 // ordering rules of 14.5.5.2. 4893 4894 // The algorithm specified above is quadratic. We instead use a 4895 // two-pass algorithm (similar to the one used to identify the 4896 // best viable function in an overload set) that identifies the 4897 // best function template (if it exists). 4898 llvm::SmallVector<FunctionDecl *, 8> TemplateMatches(Matches.begin(), 4899 Matches.end()); 4900 FunctionDecl *Result = 4901 getMostSpecialized(TemplateMatches.data(), TemplateMatches.size(), 4902 TPOC_Other, From->getLocStart(), 4903 PDiag(), 4904 PDiag(diag::err_addr_ovl_ambiguous) 4905 << TemplateMatches[0]->getDeclName(), 4906 PDiag(diag::note_ovl_candidate) 4907 << (unsigned) oc_function_template); 4908 MarkDeclarationReferenced(From->getLocStart(), Result); 4909 return Result; 4910 } 4911 4912 // [...] any function template specializations in the set are 4913 // eliminated if the set also contains a non-template function, [...] 4914 llvm::SmallVector<FunctionDecl *, 4> RemainingMatches; 4915 for (MatchIter M = Matches.begin(), MEnd = Matches.end(); M != MEnd; ++M) 4916 if ((*M)->getPrimaryTemplate() == 0) 4917 RemainingMatches.push_back(*M); 4918 4919 // [...] After such eliminations, if any, there shall remain exactly one 4920 // selected function. 4921 if (RemainingMatches.size() == 1) { 4922 FunctionDecl *Result = RemainingMatches.front(); 4923 MarkDeclarationReferenced(From->getLocStart(), Result); 4924 return Result; 4925 } 4926 4927 // FIXME: We should probably return the same thing that BestViableFunction 4928 // returns (even if we issue the diagnostics here). 4929 Diag(From->getLocStart(), diag::err_addr_ovl_ambiguous) 4930 << RemainingMatches[0]->getDeclName(); 4931 for (unsigned I = 0, N = RemainingMatches.size(); I != N; ++I) 4932 NoteOverloadCandidate(RemainingMatches[I]); 4933 return 0; 4934} 4935 4936/// \brief Given an expression that refers to an overloaded function, try to 4937/// resolve that overloaded function expression down to a single function. 4938/// 4939/// This routine can only resolve template-ids that refer to a single function 4940/// template, where that template-id refers to a single template whose template 4941/// arguments are either provided by the template-id or have defaults, 4942/// as described in C++0x [temp.arg.explicit]p3. 4943FunctionDecl *Sema::ResolveSingleFunctionTemplateSpecialization(Expr *From) { 4944 // C++ [over.over]p1: 4945 // [...] [Note: any redundant set of parentheses surrounding the 4946 // overloaded function name is ignored (5.1). ] 4947 Expr *OvlExpr = From->IgnoreParens(); 4948 4949 // C++ [over.over]p1: 4950 // [...] The overloaded function name can be preceded by the & 4951 // operator. 4952 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(OvlExpr)) { 4953 if (UnOp->getOpcode() == UnaryOperator::AddrOf) 4954 OvlExpr = UnOp->getSubExpr()->IgnoreParens(); 4955 } 4956 4957 bool HasExplicitTemplateArgs = false; 4958 TemplateArgumentListInfo ExplicitTemplateArgs; 4959 4960 llvm::SmallVector<NamedDecl*,8> Fns; 4961 4962 // Look into the overloaded expression. 4963 if (UnresolvedLookupExpr *UL 4964 = dyn_cast<UnresolvedLookupExpr>(OvlExpr)) { 4965 Fns.append(UL->decls_begin(), UL->decls_end()); 4966 if (UL->hasExplicitTemplateArgs()) { 4967 HasExplicitTemplateArgs = true; 4968 UL->copyTemplateArgumentsInto(ExplicitTemplateArgs); 4969 } 4970 } else if (UnresolvedMemberExpr *ME 4971 = dyn_cast<UnresolvedMemberExpr>(OvlExpr)) { 4972 Fns.append(ME->decls_begin(), ME->decls_end()); 4973 if (ME->hasExplicitTemplateArgs()) { 4974 HasExplicitTemplateArgs = true; 4975 ME->copyTemplateArgumentsInto(ExplicitTemplateArgs); 4976 } 4977 } 4978 4979 // If we didn't actually find any template-ids, we're done. 4980 if (Fns.empty() || !HasExplicitTemplateArgs) 4981 return 0; 4982 4983 // Look through all of the overloaded functions, searching for one 4984 // whose type matches exactly. 4985 FunctionDecl *Matched = 0; 4986 for (llvm::SmallVectorImpl<NamedDecl*>::iterator I = Fns.begin(), 4987 E = Fns.end(); I != E; ++I) { 4988 // C++0x [temp.arg.explicit]p3: 4989 // [...] In contexts where deduction is done and fails, or in contexts 4990 // where deduction is not done, if a template argument list is 4991 // specified and it, along with any default template arguments, 4992 // identifies a single function template specialization, then the 4993 // template-id is an lvalue for the function template specialization. 4994 FunctionTemplateDecl *FunctionTemplate = cast<FunctionTemplateDecl>(*I); 4995 4996 // C++ [over.over]p2: 4997 // If the name is a function template, template argument deduction is 4998 // done (14.8.2.2), and if the argument deduction succeeds, the 4999 // resulting template argument list is used to generate a single 5000 // function template specialization, which is added to the set of 5001 // overloaded functions considered. 5002 FunctionDecl *Specialization = 0; 5003 TemplateDeductionInfo Info(Context); 5004 if (TemplateDeductionResult Result 5005 = DeduceTemplateArguments(FunctionTemplate, &ExplicitTemplateArgs, 5006 Specialization, Info)) { 5007 // FIXME: make a note of the failed deduction for diagnostics. 5008 (void)Result; 5009 continue; 5010 } 5011 5012 // Multiple matches; we can't resolve to a single declaration. 5013 if (Matched) 5014 return 0; 5015 5016 Matched = Specialization; 5017 } 5018 5019 return Matched; 5020} 5021 5022/// \brief Add a single candidate to the overload set. 5023static void AddOverloadedCallCandidate(Sema &S, 5024 NamedDecl *Callee, 5025 const TemplateArgumentListInfo *ExplicitTemplateArgs, 5026 Expr **Args, unsigned NumArgs, 5027 OverloadCandidateSet &CandidateSet, 5028 bool PartialOverloading) { 5029 if (isa<UsingShadowDecl>(Callee)) 5030 Callee = cast<UsingShadowDecl>(Callee)->getTargetDecl(); 5031 5032 if (FunctionDecl *Func = dyn_cast<FunctionDecl>(Callee)) { 5033 assert(!ExplicitTemplateArgs && "Explicit template arguments?"); 5034 S.AddOverloadCandidate(Func, Args, NumArgs, CandidateSet, false, false, 5035 PartialOverloading); 5036 return; 5037 } 5038 5039 if (FunctionTemplateDecl *FuncTemplate 5040 = dyn_cast<FunctionTemplateDecl>(Callee)) { 5041 S.AddTemplateOverloadCandidate(FuncTemplate, ExplicitTemplateArgs, 5042 Args, NumArgs, CandidateSet); 5043 return; 5044 } 5045 5046 assert(false && "unhandled case in overloaded call candidate"); 5047 5048 // do nothing? 5049} 5050 5051/// \brief Add the overload candidates named by callee and/or found by argument 5052/// dependent lookup to the given overload set. 5053void Sema::AddOverloadedCallCandidates(UnresolvedLookupExpr *ULE, 5054 Expr **Args, unsigned NumArgs, 5055 OverloadCandidateSet &CandidateSet, 5056 bool PartialOverloading) { 5057 5058#ifndef NDEBUG 5059 // Verify that ArgumentDependentLookup is consistent with the rules 5060 // in C++0x [basic.lookup.argdep]p3: 5061 // 5062 // Let X be the lookup set produced by unqualified lookup (3.4.1) 5063 // and let Y be the lookup set produced by argument dependent 5064 // lookup (defined as follows). If X contains 5065 // 5066 // -- a declaration of a class member, or 5067 // 5068 // -- a block-scope function declaration that is not a 5069 // using-declaration, or 5070 // 5071 // -- a declaration that is neither a function or a function 5072 // template 5073 // 5074 // then Y is empty. 5075 5076 if (ULE->requiresADL()) { 5077 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(), 5078 E = ULE->decls_end(); I != E; ++I) { 5079 assert(!(*I)->getDeclContext()->isRecord()); 5080 assert(isa<UsingShadowDecl>(*I) || 5081 !(*I)->getDeclContext()->isFunctionOrMethod()); 5082 assert((*I)->getUnderlyingDecl()->isFunctionOrFunctionTemplate()); 5083 } 5084 } 5085#endif 5086 5087 // It would be nice to avoid this copy. 5088 TemplateArgumentListInfo TABuffer; 5089 const TemplateArgumentListInfo *ExplicitTemplateArgs = 0; 5090 if (ULE->hasExplicitTemplateArgs()) { 5091 ULE->copyTemplateArgumentsInto(TABuffer); 5092 ExplicitTemplateArgs = &TABuffer; 5093 } 5094 5095 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(), 5096 E = ULE->decls_end(); I != E; ++I) 5097 AddOverloadedCallCandidate(*this, *I, ExplicitTemplateArgs, 5098 Args, NumArgs, CandidateSet, 5099 PartialOverloading); 5100 5101 if (ULE->requiresADL()) 5102 AddArgumentDependentLookupCandidates(ULE->getName(), Args, NumArgs, 5103 ExplicitTemplateArgs, 5104 CandidateSet, 5105 PartialOverloading); 5106} 5107 5108static Sema::OwningExprResult Destroy(Sema &SemaRef, Expr *Fn, 5109 Expr **Args, unsigned NumArgs) { 5110 Fn->Destroy(SemaRef.Context); 5111 for (unsigned Arg = 0; Arg < NumArgs; ++Arg) 5112 Args[Arg]->Destroy(SemaRef.Context); 5113 return SemaRef.ExprError(); 5114} 5115 5116/// Attempts to recover from a call where no functions were found. 5117/// 5118/// Returns true if new candidates were found. 5119static Sema::OwningExprResult 5120BuildRecoveryCallExpr(Sema &SemaRef, Expr *Fn, 5121 UnresolvedLookupExpr *ULE, 5122 SourceLocation LParenLoc, 5123 Expr **Args, unsigned NumArgs, 5124 SourceLocation *CommaLocs, 5125 SourceLocation RParenLoc) { 5126 5127 CXXScopeSpec SS; 5128 if (ULE->getQualifier()) { 5129 SS.setScopeRep(ULE->getQualifier()); 5130 SS.setRange(ULE->getQualifierRange()); 5131 } 5132 5133 TemplateArgumentListInfo TABuffer; 5134 const TemplateArgumentListInfo *ExplicitTemplateArgs = 0; 5135 if (ULE->hasExplicitTemplateArgs()) { 5136 ULE->copyTemplateArgumentsInto(TABuffer); 5137 ExplicitTemplateArgs = &TABuffer; 5138 } 5139 5140 LookupResult R(SemaRef, ULE->getName(), ULE->getNameLoc(), 5141 Sema::LookupOrdinaryName); 5142 if (SemaRef.DiagnoseEmptyLookup(/*Scope=*/0, SS, R)) 5143 return Destroy(SemaRef, Fn, Args, NumArgs); 5144 5145 assert(!R.empty() && "lookup results empty despite recovery"); 5146 5147 // Build an implicit member call if appropriate. Just drop the 5148 // casts and such from the call, we don't really care. 5149 Sema::OwningExprResult NewFn = SemaRef.ExprError(); 5150 if ((*R.begin())->isCXXClassMember()) 5151 NewFn = SemaRef.BuildPossibleImplicitMemberExpr(SS, R, ExplicitTemplateArgs); 5152 else if (ExplicitTemplateArgs) 5153 NewFn = SemaRef.BuildTemplateIdExpr(SS, R, false, *ExplicitTemplateArgs); 5154 else 5155 NewFn = SemaRef.BuildDeclarationNameExpr(SS, R, false); 5156 5157 if (NewFn.isInvalid()) 5158 return Destroy(SemaRef, Fn, Args, NumArgs); 5159 5160 Fn->Destroy(SemaRef.Context); 5161 5162 // This shouldn't cause an infinite loop because we're giving it 5163 // an expression with non-empty lookup results, which should never 5164 // end up here. 5165 return SemaRef.ActOnCallExpr(/*Scope*/ 0, move(NewFn), LParenLoc, 5166 Sema::MultiExprArg(SemaRef, (void**) Args, NumArgs), 5167 CommaLocs, RParenLoc); 5168} 5169 5170/// ResolveOverloadedCallFn - Given the call expression that calls Fn 5171/// (which eventually refers to the declaration Func) and the call 5172/// arguments Args/NumArgs, attempt to resolve the function call down 5173/// to a specific function. If overload resolution succeeds, returns 5174/// the function declaration produced by overload 5175/// resolution. Otherwise, emits diagnostics, deletes all of the 5176/// arguments and Fn, and returns NULL. 5177Sema::OwningExprResult 5178Sema::BuildOverloadedCallExpr(Expr *Fn, UnresolvedLookupExpr *ULE, 5179 SourceLocation LParenLoc, 5180 Expr **Args, unsigned NumArgs, 5181 SourceLocation *CommaLocs, 5182 SourceLocation RParenLoc) { 5183#ifndef NDEBUG 5184 if (ULE->requiresADL()) { 5185 // To do ADL, we must have found an unqualified name. 5186 assert(!ULE->getQualifier() && "qualified name with ADL"); 5187 5188 // We don't perform ADL for implicit declarations of builtins. 5189 // Verify that this was correctly set up. 5190 FunctionDecl *F; 5191 if (ULE->decls_begin() + 1 == ULE->decls_end() && 5192 (F = dyn_cast<FunctionDecl>(*ULE->decls_begin())) && 5193 F->getBuiltinID() && F->isImplicit()) 5194 assert(0 && "performing ADL for builtin"); 5195 5196 // We don't perform ADL in C. 5197 assert(getLangOptions().CPlusPlus && "ADL enabled in C"); 5198 } 5199#endif 5200 5201 OverloadCandidateSet CandidateSet; 5202 5203 // Add the functions denoted by the callee to the set of candidate 5204 // functions, including those from argument-dependent lookup. 5205 AddOverloadedCallCandidates(ULE, Args, NumArgs, CandidateSet); 5206 5207 // If we found nothing, try to recover. 5208 // AddRecoveryCallCandidates diagnoses the error itself, so we just 5209 // bailout out if it fails. 5210 if (CandidateSet.empty()) 5211 return BuildRecoveryCallExpr(*this, Fn, ULE, LParenLoc, Args, NumArgs, 5212 CommaLocs, RParenLoc); 5213 5214 OverloadCandidateSet::iterator Best; 5215 switch (BestViableFunction(CandidateSet, Fn->getLocStart(), Best)) { 5216 case OR_Success: { 5217 FunctionDecl *FDecl = Best->Function; 5218 Fn = FixOverloadedFunctionReference(Fn, FDecl); 5219 return BuildResolvedCallExpr(Fn, FDecl, LParenLoc, Args, NumArgs, RParenLoc); 5220 } 5221 5222 case OR_No_Viable_Function: 5223 Diag(Fn->getSourceRange().getBegin(), 5224 diag::err_ovl_no_viable_function_in_call) 5225 << ULE->getName() << Fn->getSourceRange(); 5226 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 5227 break; 5228 5229 case OR_Ambiguous: 5230 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_ambiguous_call) 5231 << ULE->getName() << Fn->getSourceRange(); 5232 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, NumArgs); 5233 break; 5234 5235 case OR_Deleted: 5236 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_deleted_call) 5237 << Best->Function->isDeleted() 5238 << ULE->getName() 5239 << Fn->getSourceRange(); 5240 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 5241 break; 5242 } 5243 5244 // Overload resolution failed. Destroy all of the subexpressions and 5245 // return NULL. 5246 Fn->Destroy(Context); 5247 for (unsigned Arg = 0; Arg < NumArgs; ++Arg) 5248 Args[Arg]->Destroy(Context); 5249 return ExprError(); 5250} 5251 5252static bool IsOverloaded(const Sema::FunctionSet &Functions) { 5253 return Functions.size() > 1 || 5254 (Functions.size() == 1 && isa<FunctionTemplateDecl>(*Functions.begin())); 5255} 5256 5257/// \brief Create a unary operation that may resolve to an overloaded 5258/// operator. 5259/// 5260/// \param OpLoc The location of the operator itself (e.g., '*'). 5261/// 5262/// \param OpcIn The UnaryOperator::Opcode that describes this 5263/// operator. 5264/// 5265/// \param Functions The set of non-member functions that will be 5266/// considered by overload resolution. The caller needs to build this 5267/// set based on the context using, e.g., 5268/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 5269/// set should not contain any member functions; those will be added 5270/// by CreateOverloadedUnaryOp(). 5271/// 5272/// \param input The input argument. 5273Sema::OwningExprResult Sema::CreateOverloadedUnaryOp(SourceLocation OpLoc, 5274 unsigned OpcIn, 5275 FunctionSet &Functions, 5276 ExprArg input) { 5277 UnaryOperator::Opcode Opc = static_cast<UnaryOperator::Opcode>(OpcIn); 5278 Expr *Input = (Expr *)input.get(); 5279 5280 OverloadedOperatorKind Op = UnaryOperator::getOverloadedOperator(Opc); 5281 assert(Op != OO_None && "Invalid opcode for overloaded unary operator"); 5282 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 5283 5284 Expr *Args[2] = { Input, 0 }; 5285 unsigned NumArgs = 1; 5286 5287 // For post-increment and post-decrement, add the implicit '0' as 5288 // the second argument, so that we know this is a post-increment or 5289 // post-decrement. 5290 if (Opc == UnaryOperator::PostInc || Opc == UnaryOperator::PostDec) { 5291 llvm::APSInt Zero(Context.getTypeSize(Context.IntTy), false); 5292 Args[1] = new (Context) IntegerLiteral(Zero, Context.IntTy, 5293 SourceLocation()); 5294 NumArgs = 2; 5295 } 5296 5297 if (Input->isTypeDependent()) { 5298 UnresolvedLookupExpr *Fn 5299 = UnresolvedLookupExpr::Create(Context, /*Dependent*/ true, 5300 0, SourceRange(), OpName, OpLoc, 5301 /*ADL*/ true, IsOverloaded(Functions)); 5302 for (FunctionSet::iterator Func = Functions.begin(), 5303 FuncEnd = Functions.end(); 5304 Func != FuncEnd; ++Func) 5305 Fn->addDecl(*Func); 5306 5307 input.release(); 5308 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 5309 &Args[0], NumArgs, 5310 Context.DependentTy, 5311 OpLoc)); 5312 } 5313 5314 // Build an empty overload set. 5315 OverloadCandidateSet CandidateSet; 5316 5317 // Add the candidates from the given function set. 5318 AddFunctionCandidates(Functions, &Args[0], NumArgs, CandidateSet, false); 5319 5320 // Add operator candidates that are member functions. 5321 AddMemberOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 5322 5323 // Add builtin operator candidates. 5324 AddBuiltinOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 5325 5326 // Perform overload resolution. 5327 OverloadCandidateSet::iterator Best; 5328 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 5329 case OR_Success: { 5330 // We found a built-in operator or an overloaded operator. 5331 FunctionDecl *FnDecl = Best->Function; 5332 5333 if (FnDecl) { 5334 // We matched an overloaded operator. Build a call to that 5335 // operator. 5336 5337 // Convert the arguments. 5338 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 5339 if (PerformObjectArgumentInitialization(Input, Method)) 5340 return ExprError(); 5341 } else { 5342 // Convert the arguments. 5343 OwningExprResult InputInit 5344 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 5345 FnDecl->getParamDecl(0)), 5346 SourceLocation(), 5347 move(input)); 5348 if (InputInit.isInvalid()) 5349 return ExprError(); 5350 5351 input = move(InputInit); 5352 Input = (Expr *)input.get(); 5353 } 5354 5355 // Determine the result type 5356 QualType ResultTy = FnDecl->getResultType().getNonReferenceType(); 5357 5358 // Build the actual expression node. 5359 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 5360 SourceLocation()); 5361 UsualUnaryConversions(FnExpr); 5362 5363 input.release(); 5364 Args[0] = Input; 5365 ExprOwningPtr<CallExpr> TheCall(this, 5366 new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 5367 Args, NumArgs, ResultTy, OpLoc)); 5368 5369 if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall.get(), 5370 FnDecl)) 5371 return ExprError(); 5372 5373 return MaybeBindToTemporary(TheCall.release()); 5374 } else { 5375 // We matched a built-in operator. Convert the arguments, then 5376 // break out so that we will build the appropriate built-in 5377 // operator node. 5378 if (PerformImplicitConversion(Input, Best->BuiltinTypes.ParamTypes[0], 5379 Best->Conversions[0], AA_Passing)) 5380 return ExprError(); 5381 5382 break; 5383 } 5384 } 5385 5386 case OR_No_Viable_Function: 5387 // No viable function; fall through to handling this as a 5388 // built-in operator, which will produce an error message for us. 5389 break; 5390 5391 case OR_Ambiguous: 5392 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 5393 << UnaryOperator::getOpcodeStr(Opc) 5394 << Input->getSourceRange(); 5395 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, NumArgs, 5396 UnaryOperator::getOpcodeStr(Opc), OpLoc); 5397 return ExprError(); 5398 5399 case OR_Deleted: 5400 Diag(OpLoc, diag::err_ovl_deleted_oper) 5401 << Best->Function->isDeleted() 5402 << UnaryOperator::getOpcodeStr(Opc) 5403 << Input->getSourceRange(); 5404 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 5405 return ExprError(); 5406 } 5407 5408 // Either we found no viable overloaded operator or we matched a 5409 // built-in operator. In either case, fall through to trying to 5410 // build a built-in operation. 5411 input.release(); 5412 return CreateBuiltinUnaryOp(OpLoc, Opc, Owned(Input)); 5413} 5414 5415/// \brief Create a binary operation that may resolve to an overloaded 5416/// operator. 5417/// 5418/// \param OpLoc The location of the operator itself (e.g., '+'). 5419/// 5420/// \param OpcIn The BinaryOperator::Opcode that describes this 5421/// operator. 5422/// 5423/// \param Functions The set of non-member functions that will be 5424/// considered by overload resolution. The caller needs to build this 5425/// set based on the context using, e.g., 5426/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 5427/// set should not contain any member functions; those will be added 5428/// by CreateOverloadedBinOp(). 5429/// 5430/// \param LHS Left-hand argument. 5431/// \param RHS Right-hand argument. 5432Sema::OwningExprResult 5433Sema::CreateOverloadedBinOp(SourceLocation OpLoc, 5434 unsigned OpcIn, 5435 FunctionSet &Functions, 5436 Expr *LHS, Expr *RHS) { 5437 Expr *Args[2] = { LHS, RHS }; 5438 LHS=RHS=0; //Please use only Args instead of LHS/RHS couple 5439 5440 BinaryOperator::Opcode Opc = static_cast<BinaryOperator::Opcode>(OpcIn); 5441 OverloadedOperatorKind Op = BinaryOperator::getOverloadedOperator(Opc); 5442 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 5443 5444 // If either side is type-dependent, create an appropriate dependent 5445 // expression. 5446 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 5447 if (Functions.empty()) { 5448 // If there are no functions to store, just build a dependent 5449 // BinaryOperator or CompoundAssignment. 5450 if (Opc <= BinaryOperator::Assign || Opc > BinaryOperator::OrAssign) 5451 return Owned(new (Context) BinaryOperator(Args[0], Args[1], Opc, 5452 Context.DependentTy, OpLoc)); 5453 5454 return Owned(new (Context) CompoundAssignOperator(Args[0], Args[1], Opc, 5455 Context.DependentTy, 5456 Context.DependentTy, 5457 Context.DependentTy, 5458 OpLoc)); 5459 } 5460 5461 UnresolvedLookupExpr *Fn 5462 = UnresolvedLookupExpr::Create(Context, /*Dependent*/ true, 5463 0, SourceRange(), OpName, OpLoc, 5464 /* ADL */ true, IsOverloaded(Functions)); 5465 5466 for (FunctionSet::iterator Func = Functions.begin(), 5467 FuncEnd = Functions.end(); 5468 Func != FuncEnd; ++Func) 5469 Fn->addDecl(*Func); 5470 5471 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 5472 Args, 2, 5473 Context.DependentTy, 5474 OpLoc)); 5475 } 5476 5477 // If this is the .* operator, which is not overloadable, just 5478 // create a built-in binary operator. 5479 if (Opc == BinaryOperator::PtrMemD) 5480 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 5481 5482 // If this is the assignment operator, we only perform overload resolution 5483 // if the left-hand side is a class or enumeration type. This is actually 5484 // a hack. The standard requires that we do overload resolution between the 5485 // various built-in candidates, but as DR507 points out, this can lead to 5486 // problems. So we do it this way, which pretty much follows what GCC does. 5487 // Note that we go the traditional code path for compound assignment forms. 5488 if (Opc==BinaryOperator::Assign && !Args[0]->getType()->isOverloadableType()) 5489 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 5490 5491 // Build an empty overload set. 5492 OverloadCandidateSet CandidateSet; 5493 5494 // Add the candidates from the given function set. 5495 AddFunctionCandidates(Functions, Args, 2, CandidateSet, false); 5496 5497 // Add operator candidates that are member functions. 5498 AddMemberOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 5499 5500 // Add builtin operator candidates. 5501 AddBuiltinOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 5502 5503 // Perform overload resolution. 5504 OverloadCandidateSet::iterator Best; 5505 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 5506 case OR_Success: { 5507 // We found a built-in operator or an overloaded operator. 5508 FunctionDecl *FnDecl = Best->Function; 5509 5510 if (FnDecl) { 5511 // We matched an overloaded operator. Build a call to that 5512 // operator. 5513 5514 // Convert the arguments. 5515 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 5516 OwningExprResult Arg1 5517 = PerformCopyInitialization( 5518 InitializedEntity::InitializeParameter( 5519 FnDecl->getParamDecl(0)), 5520 SourceLocation(), 5521 Owned(Args[1])); 5522 if (Arg1.isInvalid()) 5523 return ExprError(); 5524 5525 if (PerformObjectArgumentInitialization(Args[0], Method)) 5526 return ExprError(); 5527 5528 Args[1] = RHS = Arg1.takeAs<Expr>(); 5529 } else { 5530 // Convert the arguments. 5531 OwningExprResult Arg0 5532 = PerformCopyInitialization( 5533 InitializedEntity::InitializeParameter( 5534 FnDecl->getParamDecl(0)), 5535 SourceLocation(), 5536 Owned(Args[0])); 5537 if (Arg0.isInvalid()) 5538 return ExprError(); 5539 5540 OwningExprResult Arg1 5541 = PerformCopyInitialization( 5542 InitializedEntity::InitializeParameter( 5543 FnDecl->getParamDecl(1)), 5544 SourceLocation(), 5545 Owned(Args[1])); 5546 if (Arg1.isInvalid()) 5547 return ExprError(); 5548 Args[0] = LHS = Arg0.takeAs<Expr>(); 5549 Args[1] = RHS = Arg1.takeAs<Expr>(); 5550 } 5551 5552 // Determine the result type 5553 QualType ResultTy 5554 = FnDecl->getType()->getAs<FunctionType>()->getResultType(); 5555 ResultTy = ResultTy.getNonReferenceType(); 5556 5557 // Build the actual expression node. 5558 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 5559 OpLoc); 5560 UsualUnaryConversions(FnExpr); 5561 5562 ExprOwningPtr<CXXOperatorCallExpr> 5563 TheCall(this, new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 5564 Args, 2, ResultTy, 5565 OpLoc)); 5566 5567 if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall.get(), 5568 FnDecl)) 5569 return ExprError(); 5570 5571 return MaybeBindToTemporary(TheCall.release()); 5572 } else { 5573 // We matched a built-in operator. Convert the arguments, then 5574 // break out so that we will build the appropriate built-in 5575 // operator node. 5576 if (PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 5577 Best->Conversions[0], AA_Passing) || 5578 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 5579 Best->Conversions[1], AA_Passing)) 5580 return ExprError(); 5581 5582 break; 5583 } 5584 } 5585 5586 case OR_No_Viable_Function: { 5587 // C++ [over.match.oper]p9: 5588 // If the operator is the operator , [...] and there are no 5589 // viable functions, then the operator is assumed to be the 5590 // built-in operator and interpreted according to clause 5. 5591 if (Opc == BinaryOperator::Comma) 5592 break; 5593 5594 // For class as left operand for assignment or compound assigment operator 5595 // do not fall through to handling in built-in, but report that no overloaded 5596 // assignment operator found 5597 OwningExprResult Result = ExprError(); 5598 if (Args[0]->getType()->isRecordType() && 5599 Opc >= BinaryOperator::Assign && Opc <= BinaryOperator::OrAssign) { 5600 Diag(OpLoc, diag::err_ovl_no_viable_oper) 5601 << BinaryOperator::getOpcodeStr(Opc) 5602 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 5603 } else { 5604 // No viable function; try to create a built-in operation, which will 5605 // produce an error. Then, show the non-viable candidates. 5606 Result = CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 5607 } 5608 assert(Result.isInvalid() && 5609 "C++ binary operator overloading is missing candidates!"); 5610 if (Result.isInvalid()) 5611 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2, 5612 BinaryOperator::getOpcodeStr(Opc), OpLoc); 5613 return move(Result); 5614 } 5615 5616 case OR_Ambiguous: 5617 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 5618 << BinaryOperator::getOpcodeStr(Opc) 5619 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 5620 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, 2, 5621 BinaryOperator::getOpcodeStr(Opc), OpLoc); 5622 return ExprError(); 5623 5624 case OR_Deleted: 5625 Diag(OpLoc, diag::err_ovl_deleted_oper) 5626 << Best->Function->isDeleted() 5627 << BinaryOperator::getOpcodeStr(Opc) 5628 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 5629 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2); 5630 return ExprError(); 5631 } 5632 5633 // We matched a built-in operator; build it. 5634 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 5635} 5636 5637Action::OwningExprResult 5638Sema::CreateOverloadedArraySubscriptExpr(SourceLocation LLoc, 5639 SourceLocation RLoc, 5640 ExprArg Base, ExprArg Idx) { 5641 Expr *Args[2] = { static_cast<Expr*>(Base.get()), 5642 static_cast<Expr*>(Idx.get()) }; 5643 DeclarationName OpName = 5644 Context.DeclarationNames.getCXXOperatorName(OO_Subscript); 5645 5646 // If either side is type-dependent, create an appropriate dependent 5647 // expression. 5648 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 5649 5650 UnresolvedLookupExpr *Fn 5651 = UnresolvedLookupExpr::Create(Context, /*Dependent*/ true, 5652 0, SourceRange(), OpName, LLoc, 5653 /*ADL*/ true, /*Overloaded*/ false); 5654 // Can't add any actual overloads yet 5655 5656 Base.release(); 5657 Idx.release(); 5658 return Owned(new (Context) CXXOperatorCallExpr(Context, OO_Subscript, Fn, 5659 Args, 2, 5660 Context.DependentTy, 5661 RLoc)); 5662 } 5663 5664 // Build an empty overload set. 5665 OverloadCandidateSet CandidateSet; 5666 5667 // Subscript can only be overloaded as a member function. 5668 5669 // Add operator candidates that are member functions. 5670 AddMemberOperatorCandidates(OO_Subscript, LLoc, Args, 2, CandidateSet); 5671 5672 // Add builtin operator candidates. 5673 AddBuiltinOperatorCandidates(OO_Subscript, LLoc, Args, 2, CandidateSet); 5674 5675 // Perform overload resolution. 5676 OverloadCandidateSet::iterator Best; 5677 switch (BestViableFunction(CandidateSet, LLoc, Best)) { 5678 case OR_Success: { 5679 // We found a built-in operator or an overloaded operator. 5680 FunctionDecl *FnDecl = Best->Function; 5681 5682 if (FnDecl) { 5683 // We matched an overloaded operator. Build a call to that 5684 // operator. 5685 5686 // Convert the arguments. 5687 CXXMethodDecl *Method = cast<CXXMethodDecl>(FnDecl); 5688 if (PerformObjectArgumentInitialization(Args[0], Method) || 5689 PerformCopyInitialization(Args[1], 5690 FnDecl->getParamDecl(0)->getType(), 5691 AA_Passing)) 5692 return ExprError(); 5693 5694 // Determine the result type 5695 QualType ResultTy 5696 = FnDecl->getType()->getAs<FunctionType>()->getResultType(); 5697 ResultTy = ResultTy.getNonReferenceType(); 5698 5699 // Build the actual expression node. 5700 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 5701 LLoc); 5702 UsualUnaryConversions(FnExpr); 5703 5704 Base.release(); 5705 Idx.release(); 5706 ExprOwningPtr<CXXOperatorCallExpr> 5707 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Subscript, 5708 FnExpr, Args, 2, 5709 ResultTy, RLoc)); 5710 5711 if (CheckCallReturnType(FnDecl->getResultType(), LLoc, TheCall.get(), 5712 FnDecl)) 5713 return ExprError(); 5714 5715 return MaybeBindToTemporary(TheCall.release()); 5716 } else { 5717 // We matched a built-in operator. Convert the arguments, then 5718 // break out so that we will build the appropriate built-in 5719 // operator node. 5720 if (PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 5721 Best->Conversions[0], AA_Passing) || 5722 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 5723 Best->Conversions[1], AA_Passing)) 5724 return ExprError(); 5725 5726 break; 5727 } 5728 } 5729 5730 case OR_No_Viable_Function: { 5731 if (CandidateSet.empty()) 5732 Diag(LLoc, diag::err_ovl_no_oper) 5733 << Args[0]->getType() << /*subscript*/ 0 5734 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 5735 else 5736 Diag(LLoc, diag::err_ovl_no_viable_subscript) 5737 << Args[0]->getType() 5738 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 5739 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2, 5740 "[]", LLoc); 5741 return ExprError(); 5742 } 5743 5744 case OR_Ambiguous: 5745 Diag(LLoc, diag::err_ovl_ambiguous_oper) 5746 << "[]" << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 5747 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, 2, 5748 "[]", LLoc); 5749 return ExprError(); 5750 5751 case OR_Deleted: 5752 Diag(LLoc, diag::err_ovl_deleted_oper) 5753 << Best->Function->isDeleted() << "[]" 5754 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 5755 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2, 5756 "[]", LLoc); 5757 return ExprError(); 5758 } 5759 5760 // We matched a built-in operator; build it. 5761 Base.release(); 5762 Idx.release(); 5763 return CreateBuiltinArraySubscriptExpr(Owned(Args[0]), LLoc, 5764 Owned(Args[1]), RLoc); 5765} 5766 5767/// BuildCallToMemberFunction - Build a call to a member 5768/// function. MemExpr is the expression that refers to the member 5769/// function (and includes the object parameter), Args/NumArgs are the 5770/// arguments to the function call (not including the object 5771/// parameter). The caller needs to validate that the member 5772/// expression refers to a member function or an overloaded member 5773/// function. 5774Sema::OwningExprResult 5775Sema::BuildCallToMemberFunction(Scope *S, Expr *MemExprE, 5776 SourceLocation LParenLoc, Expr **Args, 5777 unsigned NumArgs, SourceLocation *CommaLocs, 5778 SourceLocation RParenLoc) { 5779 // Dig out the member expression. This holds both the object 5780 // argument and the member function we're referring to. 5781 Expr *NakedMemExpr = MemExprE->IgnoreParens(); 5782 5783 MemberExpr *MemExpr; 5784 CXXMethodDecl *Method = 0; 5785 if (isa<MemberExpr>(NakedMemExpr)) { 5786 MemExpr = cast<MemberExpr>(NakedMemExpr); 5787 Method = cast<CXXMethodDecl>(MemExpr->getMemberDecl()); 5788 } else { 5789 UnresolvedMemberExpr *UnresExpr = cast<UnresolvedMemberExpr>(NakedMemExpr); 5790 5791 QualType ObjectType = UnresExpr->getBaseType(); 5792 5793 // Add overload candidates 5794 OverloadCandidateSet CandidateSet; 5795 5796 // FIXME: avoid copy. 5797 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 5798 if (UnresExpr->hasExplicitTemplateArgs()) { 5799 UnresExpr->copyTemplateArgumentsInto(TemplateArgsBuffer); 5800 TemplateArgs = &TemplateArgsBuffer; 5801 } 5802 5803 for (UnresolvedMemberExpr::decls_iterator I = UnresExpr->decls_begin(), 5804 E = UnresExpr->decls_end(); I != E; ++I) { 5805 5806 NamedDecl *Func = *I; 5807 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(Func->getDeclContext()); 5808 if (isa<UsingShadowDecl>(Func)) 5809 Func = cast<UsingShadowDecl>(Func)->getTargetDecl(); 5810 5811 if ((Method = dyn_cast<CXXMethodDecl>(Func))) { 5812 // If explicit template arguments were provided, we can't call a 5813 // non-template member function. 5814 if (TemplateArgs) 5815 continue; 5816 5817 AddMethodCandidate(Method, ActingDC, ObjectType, Args, NumArgs, 5818 CandidateSet, /*SuppressUserConversions=*/false); 5819 } else { 5820 AddMethodTemplateCandidate(cast<FunctionTemplateDecl>(Func), 5821 ActingDC, TemplateArgs, 5822 ObjectType, Args, NumArgs, 5823 CandidateSet, 5824 /*SuppressUsedConversions=*/false); 5825 } 5826 } 5827 5828 DeclarationName DeclName = UnresExpr->getMemberName(); 5829 5830 OverloadCandidateSet::iterator Best; 5831 switch (BestViableFunction(CandidateSet, UnresExpr->getLocStart(), Best)) { 5832 case OR_Success: 5833 Method = cast<CXXMethodDecl>(Best->Function); 5834 break; 5835 5836 case OR_No_Viable_Function: 5837 Diag(UnresExpr->getMemberLoc(), 5838 diag::err_ovl_no_viable_member_function_in_call) 5839 << DeclName << MemExprE->getSourceRange(); 5840 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 5841 // FIXME: Leaking incoming expressions! 5842 return ExprError(); 5843 5844 case OR_Ambiguous: 5845 Diag(UnresExpr->getMemberLoc(), diag::err_ovl_ambiguous_member_call) 5846 << DeclName << MemExprE->getSourceRange(); 5847 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 5848 // FIXME: Leaking incoming expressions! 5849 return ExprError(); 5850 5851 case OR_Deleted: 5852 Diag(UnresExpr->getMemberLoc(), diag::err_ovl_deleted_member_call) 5853 << Best->Function->isDeleted() 5854 << DeclName << MemExprE->getSourceRange(); 5855 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 5856 // FIXME: Leaking incoming expressions! 5857 return ExprError(); 5858 } 5859 5860 MemExprE = FixOverloadedFunctionReference(MemExprE, Method); 5861 5862 // If overload resolution picked a static member, build a 5863 // non-member call based on that function. 5864 if (Method->isStatic()) { 5865 return BuildResolvedCallExpr(MemExprE, Method, LParenLoc, 5866 Args, NumArgs, RParenLoc); 5867 } 5868 5869 MemExpr = cast<MemberExpr>(MemExprE->IgnoreParens()); 5870 } 5871 5872 assert(Method && "Member call to something that isn't a method?"); 5873 ExprOwningPtr<CXXMemberCallExpr> 5874 TheCall(this, new (Context) CXXMemberCallExpr(Context, MemExprE, Args, 5875 NumArgs, 5876 Method->getResultType().getNonReferenceType(), 5877 RParenLoc)); 5878 5879 // Check for a valid return type. 5880 if (CheckCallReturnType(Method->getResultType(), MemExpr->getMemberLoc(), 5881 TheCall.get(), Method)) 5882 return ExprError(); 5883 5884 // Convert the object argument (for a non-static member function call). 5885 Expr *ObjectArg = MemExpr->getBase(); 5886 if (!Method->isStatic() && 5887 PerformObjectArgumentInitialization(ObjectArg, Method)) 5888 return ExprError(); 5889 MemExpr->setBase(ObjectArg); 5890 5891 // Convert the rest of the arguments 5892 const FunctionProtoType *Proto = cast<FunctionProtoType>(Method->getType()); 5893 if (ConvertArgumentsForCall(&*TheCall, MemExpr, Method, Proto, Args, NumArgs, 5894 RParenLoc)) 5895 return ExprError(); 5896 5897 if (CheckFunctionCall(Method, TheCall.get())) 5898 return ExprError(); 5899 5900 return MaybeBindToTemporary(TheCall.release()); 5901} 5902 5903/// BuildCallToObjectOfClassType - Build a call to an object of class 5904/// type (C++ [over.call.object]), which can end up invoking an 5905/// overloaded function call operator (@c operator()) or performing a 5906/// user-defined conversion on the object argument. 5907Sema::ExprResult 5908Sema::BuildCallToObjectOfClassType(Scope *S, Expr *Object, 5909 SourceLocation LParenLoc, 5910 Expr **Args, unsigned NumArgs, 5911 SourceLocation *CommaLocs, 5912 SourceLocation RParenLoc) { 5913 assert(Object->getType()->isRecordType() && "Requires object type argument"); 5914 const RecordType *Record = Object->getType()->getAs<RecordType>(); 5915 5916 // C++ [over.call.object]p1: 5917 // If the primary-expression E in the function call syntax 5918 // evaluates to a class object of type "cv T", then the set of 5919 // candidate functions includes at least the function call 5920 // operators of T. The function call operators of T are obtained by 5921 // ordinary lookup of the name operator() in the context of 5922 // (E).operator(). 5923 OverloadCandidateSet CandidateSet; 5924 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Call); 5925 5926 if (RequireCompleteType(LParenLoc, Object->getType(), 5927 PartialDiagnostic(diag::err_incomplete_object_call) 5928 << Object->getSourceRange())) 5929 return true; 5930 5931 LookupResult R(*this, OpName, LParenLoc, LookupOrdinaryName); 5932 LookupQualifiedName(R, Record->getDecl()); 5933 R.suppressDiagnostics(); 5934 5935 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 5936 Oper != OperEnd; ++Oper) { 5937 AddMethodCandidate(*Oper, Object->getType(), Args, NumArgs, CandidateSet, 5938 /*SuppressUserConversions=*/ false); 5939 } 5940 5941 // C++ [over.call.object]p2: 5942 // In addition, for each conversion function declared in T of the 5943 // form 5944 // 5945 // operator conversion-type-id () cv-qualifier; 5946 // 5947 // where cv-qualifier is the same cv-qualification as, or a 5948 // greater cv-qualification than, cv, and where conversion-type-id 5949 // denotes the type "pointer to function of (P1,...,Pn) returning 5950 // R", or the type "reference to pointer to function of 5951 // (P1,...,Pn) returning R", or the type "reference to function 5952 // of (P1,...,Pn) returning R", a surrogate call function [...] 5953 // is also considered as a candidate function. Similarly, 5954 // surrogate call functions are added to the set of candidate 5955 // functions for each conversion function declared in an 5956 // accessible base class provided the function is not hidden 5957 // within T by another intervening declaration. 5958 const UnresolvedSetImpl *Conversions 5959 = cast<CXXRecordDecl>(Record->getDecl())->getVisibleConversionFunctions(); 5960 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 5961 E = Conversions->end(); I != E; ++I) { 5962 NamedDecl *D = *I; 5963 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext()); 5964 if (isa<UsingShadowDecl>(D)) 5965 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 5966 5967 // Skip over templated conversion functions; they aren't 5968 // surrogates. 5969 if (isa<FunctionTemplateDecl>(D)) 5970 continue; 5971 5972 CXXConversionDecl *Conv = cast<CXXConversionDecl>(D); 5973 5974 // Strip the reference type (if any) and then the pointer type (if 5975 // any) to get down to what might be a function type. 5976 QualType ConvType = Conv->getConversionType().getNonReferenceType(); 5977 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 5978 ConvType = ConvPtrType->getPointeeType(); 5979 5980 if (const FunctionProtoType *Proto = ConvType->getAs<FunctionProtoType>()) 5981 AddSurrogateCandidate(Conv, ActingContext, Proto, 5982 Object->getType(), Args, NumArgs, 5983 CandidateSet); 5984 } 5985 5986 // Perform overload resolution. 5987 OverloadCandidateSet::iterator Best; 5988 switch (BestViableFunction(CandidateSet, Object->getLocStart(), Best)) { 5989 case OR_Success: 5990 // Overload resolution succeeded; we'll build the appropriate call 5991 // below. 5992 break; 5993 5994 case OR_No_Viable_Function: 5995 if (CandidateSet.empty()) 5996 Diag(Object->getSourceRange().getBegin(), diag::err_ovl_no_oper) 5997 << Object->getType() << /*call*/ 1 5998 << Object->getSourceRange(); 5999 else 6000 Diag(Object->getSourceRange().getBegin(), 6001 diag::err_ovl_no_viable_object_call) 6002 << Object->getType() << Object->getSourceRange(); 6003 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6004 break; 6005 6006 case OR_Ambiguous: 6007 Diag(Object->getSourceRange().getBegin(), 6008 diag::err_ovl_ambiguous_object_call) 6009 << Object->getType() << Object->getSourceRange(); 6010 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, NumArgs); 6011 break; 6012 6013 case OR_Deleted: 6014 Diag(Object->getSourceRange().getBegin(), 6015 diag::err_ovl_deleted_object_call) 6016 << Best->Function->isDeleted() 6017 << Object->getType() << Object->getSourceRange(); 6018 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6019 break; 6020 } 6021 6022 if (Best == CandidateSet.end()) { 6023 // We had an error; delete all of the subexpressions and return 6024 // the error. 6025 Object->Destroy(Context); 6026 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 6027 Args[ArgIdx]->Destroy(Context); 6028 return true; 6029 } 6030 6031 if (Best->Function == 0) { 6032 // Since there is no function declaration, this is one of the 6033 // surrogate candidates. Dig out the conversion function. 6034 CXXConversionDecl *Conv 6035 = cast<CXXConversionDecl>( 6036 Best->Conversions[0].UserDefined.ConversionFunction); 6037 6038 // We selected one of the surrogate functions that converts the 6039 // object parameter to a function pointer. Perform the conversion 6040 // on the object argument, then let ActOnCallExpr finish the job. 6041 6042 // Create an implicit member expr to refer to the conversion operator. 6043 // and then call it. 6044 CXXMemberCallExpr *CE = BuildCXXMemberCallExpr(Object, Conv); 6045 6046 return ActOnCallExpr(S, ExprArg(*this, CE), LParenLoc, 6047 MultiExprArg(*this, (ExprTy**)Args, NumArgs), 6048 CommaLocs, RParenLoc).release(); 6049 } 6050 6051 // We found an overloaded operator(). Build a CXXOperatorCallExpr 6052 // that calls this method, using Object for the implicit object 6053 // parameter and passing along the remaining arguments. 6054 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 6055 const FunctionProtoType *Proto = Method->getType()->getAs<FunctionProtoType>(); 6056 6057 unsigned NumArgsInProto = Proto->getNumArgs(); 6058 unsigned NumArgsToCheck = NumArgs; 6059 6060 // Build the full argument list for the method call (the 6061 // implicit object parameter is placed at the beginning of the 6062 // list). 6063 Expr **MethodArgs; 6064 if (NumArgs < NumArgsInProto) { 6065 NumArgsToCheck = NumArgsInProto; 6066 MethodArgs = new Expr*[NumArgsInProto + 1]; 6067 } else { 6068 MethodArgs = new Expr*[NumArgs + 1]; 6069 } 6070 MethodArgs[0] = Object; 6071 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 6072 MethodArgs[ArgIdx + 1] = Args[ArgIdx]; 6073 6074 Expr *NewFn = new (Context) DeclRefExpr(Method, Method->getType(), 6075 SourceLocation()); 6076 UsualUnaryConversions(NewFn); 6077 6078 // Once we've built TheCall, all of the expressions are properly 6079 // owned. 6080 QualType ResultTy = Method->getResultType().getNonReferenceType(); 6081 ExprOwningPtr<CXXOperatorCallExpr> 6082 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Call, NewFn, 6083 MethodArgs, NumArgs + 1, 6084 ResultTy, RParenLoc)); 6085 delete [] MethodArgs; 6086 6087 if (CheckCallReturnType(Method->getResultType(), LParenLoc, TheCall.get(), 6088 Method)) 6089 return true; 6090 6091 // We may have default arguments. If so, we need to allocate more 6092 // slots in the call for them. 6093 if (NumArgs < NumArgsInProto) 6094 TheCall->setNumArgs(Context, NumArgsInProto + 1); 6095 else if (NumArgs > NumArgsInProto) 6096 NumArgsToCheck = NumArgsInProto; 6097 6098 bool IsError = false; 6099 6100 // Initialize the implicit object parameter. 6101 IsError |= PerformObjectArgumentInitialization(Object, Method); 6102 TheCall->setArg(0, Object); 6103 6104 6105 // Check the argument types. 6106 for (unsigned i = 0; i != NumArgsToCheck; i++) { 6107 Expr *Arg; 6108 if (i < NumArgs) { 6109 Arg = Args[i]; 6110 6111 // Pass the argument. 6112 QualType ProtoArgType = Proto->getArgType(i); 6113 IsError |= PerformCopyInitialization(Arg, ProtoArgType, AA_Passing); 6114 } else { 6115 OwningExprResult DefArg 6116 = BuildCXXDefaultArgExpr(LParenLoc, Method, Method->getParamDecl(i)); 6117 if (DefArg.isInvalid()) { 6118 IsError = true; 6119 break; 6120 } 6121 6122 Arg = DefArg.takeAs<Expr>(); 6123 } 6124 6125 TheCall->setArg(i + 1, Arg); 6126 } 6127 6128 // If this is a variadic call, handle args passed through "...". 6129 if (Proto->isVariadic()) { 6130 // Promote the arguments (C99 6.5.2.2p7). 6131 for (unsigned i = NumArgsInProto; i != NumArgs; i++) { 6132 Expr *Arg = Args[i]; 6133 IsError |= DefaultVariadicArgumentPromotion(Arg, VariadicMethod); 6134 TheCall->setArg(i + 1, Arg); 6135 } 6136 } 6137 6138 if (IsError) return true; 6139 6140 if (CheckFunctionCall(Method, TheCall.get())) 6141 return true; 6142 6143 return MaybeBindToTemporary(TheCall.release()).release(); 6144} 6145 6146/// BuildOverloadedArrowExpr - Build a call to an overloaded @c operator-> 6147/// (if one exists), where @c Base is an expression of class type and 6148/// @c Member is the name of the member we're trying to find. 6149Sema::OwningExprResult 6150Sema::BuildOverloadedArrowExpr(Scope *S, ExprArg BaseIn, SourceLocation OpLoc) { 6151 Expr *Base = static_cast<Expr *>(BaseIn.get()); 6152 assert(Base->getType()->isRecordType() && "left-hand side must have class type"); 6153 6154 // C++ [over.ref]p1: 6155 // 6156 // [...] An expression x->m is interpreted as (x.operator->())->m 6157 // for a class object x of type T if T::operator->() exists and if 6158 // the operator is selected as the best match function by the 6159 // overload resolution mechanism (13.3). 6160 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Arrow); 6161 OverloadCandidateSet CandidateSet; 6162 const RecordType *BaseRecord = Base->getType()->getAs<RecordType>(); 6163 6164 if (RequireCompleteType(Base->getLocStart(), Base->getType(), 6165 PDiag(diag::err_typecheck_incomplete_tag) 6166 << Base->getSourceRange())) 6167 return ExprError(); 6168 6169 LookupResult R(*this, OpName, OpLoc, LookupOrdinaryName); 6170 LookupQualifiedName(R, BaseRecord->getDecl()); 6171 R.suppressDiagnostics(); 6172 6173 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 6174 Oper != OperEnd; ++Oper) { 6175 NamedDecl *D = *Oper; 6176 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext()); 6177 if (isa<UsingShadowDecl>(D)) 6178 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 6179 6180 AddMethodCandidate(cast<CXXMethodDecl>(D), ActingContext, 6181 Base->getType(), 0, 0, CandidateSet, 6182 /*SuppressUserConversions=*/false); 6183 } 6184 6185 // Perform overload resolution. 6186 OverloadCandidateSet::iterator Best; 6187 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 6188 case OR_Success: 6189 // Overload resolution succeeded; we'll build the call below. 6190 break; 6191 6192 case OR_No_Viable_Function: 6193 if (CandidateSet.empty()) 6194 Diag(OpLoc, diag::err_typecheck_member_reference_arrow) 6195 << Base->getType() << Base->getSourceRange(); 6196 else 6197 Diag(OpLoc, diag::err_ovl_no_viable_oper) 6198 << "operator->" << Base->getSourceRange(); 6199 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, &Base, 1); 6200 return ExprError(); 6201 6202 case OR_Ambiguous: 6203 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 6204 << "->" << Base->getSourceRange(); 6205 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, &Base, 1); 6206 return ExprError(); 6207 6208 case OR_Deleted: 6209 Diag(OpLoc, diag::err_ovl_deleted_oper) 6210 << Best->Function->isDeleted() 6211 << "->" << Base->getSourceRange(); 6212 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, &Base, 1); 6213 return ExprError(); 6214 } 6215 6216 // Convert the object parameter. 6217 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 6218 if (PerformObjectArgumentInitialization(Base, Method)) 6219 return ExprError(); 6220 6221 // No concerns about early exits now. 6222 BaseIn.release(); 6223 6224 // Build the operator call. 6225 Expr *FnExpr = new (Context) DeclRefExpr(Method, Method->getType(), 6226 SourceLocation()); 6227 UsualUnaryConversions(FnExpr); 6228 6229 QualType ResultTy = Method->getResultType().getNonReferenceType(); 6230 ExprOwningPtr<CXXOperatorCallExpr> 6231 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Arrow, FnExpr, 6232 &Base, 1, ResultTy, OpLoc)); 6233 6234 if (CheckCallReturnType(Method->getResultType(), OpLoc, TheCall.get(), 6235 Method)) 6236 return ExprError(); 6237 return move(TheCall); 6238} 6239 6240/// FixOverloadedFunctionReference - E is an expression that refers to 6241/// a C++ overloaded function (possibly with some parentheses and 6242/// perhaps a '&' around it). We have resolved the overloaded function 6243/// to the function declaration Fn, so patch up the expression E to 6244/// refer (possibly indirectly) to Fn. Returns the new expr. 6245Expr *Sema::FixOverloadedFunctionReference(Expr *E, FunctionDecl *Fn) { 6246 if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) { 6247 Expr *SubExpr = FixOverloadedFunctionReference(PE->getSubExpr(), Fn); 6248 if (SubExpr == PE->getSubExpr()) 6249 return PE->Retain(); 6250 6251 return new (Context) ParenExpr(PE->getLParen(), PE->getRParen(), SubExpr); 6252 } 6253 6254 if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) { 6255 Expr *SubExpr = FixOverloadedFunctionReference(ICE->getSubExpr(), Fn); 6256 assert(Context.hasSameType(ICE->getSubExpr()->getType(), 6257 SubExpr->getType()) && 6258 "Implicit cast type cannot be determined from overload"); 6259 if (SubExpr == ICE->getSubExpr()) 6260 return ICE->Retain(); 6261 6262 return new (Context) ImplicitCastExpr(ICE->getType(), 6263 ICE->getCastKind(), 6264 SubExpr, 6265 ICE->isLvalueCast()); 6266 } 6267 6268 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(E)) { 6269 assert(UnOp->getOpcode() == UnaryOperator::AddrOf && 6270 "Can only take the address of an overloaded function"); 6271 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 6272 if (Method->isStatic()) { 6273 // Do nothing: static member functions aren't any different 6274 // from non-member functions. 6275 } else { 6276 // Fix the sub expression, which really has to be an 6277 // UnresolvedLookupExpr holding an overloaded member function 6278 // or template. 6279 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(), Fn); 6280 if (SubExpr == UnOp->getSubExpr()) 6281 return UnOp->Retain(); 6282 6283 assert(isa<DeclRefExpr>(SubExpr) 6284 && "fixed to something other than a decl ref"); 6285 assert(cast<DeclRefExpr>(SubExpr)->getQualifier() 6286 && "fixed to a member ref with no nested name qualifier"); 6287 6288 // We have taken the address of a pointer to member 6289 // function. Perform the computation here so that we get the 6290 // appropriate pointer to member type. 6291 QualType ClassType 6292 = Context.getTypeDeclType(cast<RecordDecl>(Method->getDeclContext())); 6293 QualType MemPtrType 6294 = Context.getMemberPointerType(Fn->getType(), ClassType.getTypePtr()); 6295 6296 return new (Context) UnaryOperator(SubExpr, UnaryOperator::AddrOf, 6297 MemPtrType, UnOp->getOperatorLoc()); 6298 } 6299 } 6300 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(), Fn); 6301 if (SubExpr == UnOp->getSubExpr()) 6302 return UnOp->Retain(); 6303 6304 return new (Context) UnaryOperator(SubExpr, UnaryOperator::AddrOf, 6305 Context.getPointerType(SubExpr->getType()), 6306 UnOp->getOperatorLoc()); 6307 } 6308 6309 if (UnresolvedLookupExpr *ULE = dyn_cast<UnresolvedLookupExpr>(E)) { 6310 // FIXME: avoid copy. 6311 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 6312 if (ULE->hasExplicitTemplateArgs()) { 6313 ULE->copyTemplateArgumentsInto(TemplateArgsBuffer); 6314 TemplateArgs = &TemplateArgsBuffer; 6315 } 6316 6317 return DeclRefExpr::Create(Context, 6318 ULE->getQualifier(), 6319 ULE->getQualifierRange(), 6320 Fn, 6321 ULE->getNameLoc(), 6322 Fn->getType(), 6323 TemplateArgs); 6324 } 6325 6326 if (UnresolvedMemberExpr *MemExpr = dyn_cast<UnresolvedMemberExpr>(E)) { 6327 // FIXME: avoid copy. 6328 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 6329 if (MemExpr->hasExplicitTemplateArgs()) { 6330 MemExpr->copyTemplateArgumentsInto(TemplateArgsBuffer); 6331 TemplateArgs = &TemplateArgsBuffer; 6332 } 6333 6334 Expr *Base; 6335 6336 // If we're filling in 6337 if (MemExpr->isImplicitAccess()) { 6338 if (cast<CXXMethodDecl>(Fn)->isStatic()) { 6339 return DeclRefExpr::Create(Context, 6340 MemExpr->getQualifier(), 6341 MemExpr->getQualifierRange(), 6342 Fn, 6343 MemExpr->getMemberLoc(), 6344 Fn->getType(), 6345 TemplateArgs); 6346 } else { 6347 SourceLocation Loc = MemExpr->getMemberLoc(); 6348 if (MemExpr->getQualifier()) 6349 Loc = MemExpr->getQualifierRange().getBegin(); 6350 Base = new (Context) CXXThisExpr(Loc, 6351 MemExpr->getBaseType(), 6352 /*isImplicit=*/true); 6353 } 6354 } else 6355 Base = MemExpr->getBase()->Retain(); 6356 6357 return MemberExpr::Create(Context, Base, 6358 MemExpr->isArrow(), 6359 MemExpr->getQualifier(), 6360 MemExpr->getQualifierRange(), 6361 Fn, 6362 MemExpr->getMemberLoc(), 6363 TemplateArgs, 6364 Fn->getType()); 6365 } 6366 6367 assert(false && "Invalid reference to overloaded function"); 6368 return E->Retain(); 6369} 6370 6371Sema::OwningExprResult Sema::FixOverloadedFunctionReference(OwningExprResult E, 6372 FunctionDecl *Fn) { 6373 return Owned(FixOverloadedFunctionReference((Expr *)E.get(), Fn)); 6374} 6375 6376} // end namespace clang 6377