SemaOverload.cpp revision 717e8910bb6444f744db78d8d1a020f8f57a83e1
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_trivial_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_final_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 Candidate.Conversions[0] = ObjectInit; 2900 return; 2901 } 2902 2903 // The first conversion is actually a user-defined conversion whose 2904 // first conversion is ObjectInit's standard conversion (which is 2905 // effectively a reference binding). Record it as such. 2906 Candidate.Conversions[0].setUserDefined(); 2907 Candidate.Conversions[0].UserDefined.Before = ObjectInit.Standard; 2908 Candidate.Conversions[0].UserDefined.EllipsisConversion = false; 2909 Candidate.Conversions[0].UserDefined.ConversionFunction = Conversion; 2910 Candidate.Conversions[0].UserDefined.After 2911 = Candidate.Conversions[0].UserDefined.Before; 2912 Candidate.Conversions[0].UserDefined.After.setAsIdentityConversion(); 2913 2914 // Find the 2915 unsigned NumArgsInProto = Proto->getNumArgs(); 2916 2917 // (C++ 13.3.2p2): A candidate function having fewer than m 2918 // parameters is viable only if it has an ellipsis in its parameter 2919 // list (8.3.5). 2920 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 2921 Candidate.Viable = false; 2922 Candidate.FailureKind = ovl_fail_too_many_arguments; 2923 return; 2924 } 2925 2926 // Function types don't have any default arguments, so just check if 2927 // we have enough arguments. 2928 if (NumArgs < NumArgsInProto) { 2929 // Not enough arguments. 2930 Candidate.Viable = false; 2931 Candidate.FailureKind = ovl_fail_too_few_arguments; 2932 return; 2933 } 2934 2935 // Determine the implicit conversion sequences for each of the 2936 // arguments. 2937 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2938 if (ArgIdx < NumArgsInProto) { 2939 // (C++ 13.3.2p3): for F to be a viable function, there shall 2940 // exist for each argument an implicit conversion sequence 2941 // (13.3.3.1) that converts that argument to the corresponding 2942 // parameter of F. 2943 QualType ParamType = Proto->getArgType(ArgIdx); 2944 Candidate.Conversions[ArgIdx + 1] 2945 = TryCopyInitialization(Args[ArgIdx], ParamType, 2946 /*SuppressUserConversions=*/false, 2947 /*ForceRValue=*/false, 2948 /*InOverloadResolution=*/false); 2949 if (Candidate.Conversions[ArgIdx + 1].isBad()) { 2950 Candidate.Viable = false; 2951 Candidate.FailureKind = ovl_fail_bad_conversion; 2952 break; 2953 } 2954 } else { 2955 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2956 // argument for which there is no corresponding parameter is 2957 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2958 Candidate.Conversions[ArgIdx + 1].setEllipsis(); 2959 } 2960 } 2961} 2962 2963// FIXME: This will eventually be removed, once we've migrated all of the 2964// operator overloading logic over to the scheme used by binary operators, which 2965// works for template instantiation. 2966void Sema::AddOperatorCandidates(OverloadedOperatorKind Op, Scope *S, 2967 SourceLocation OpLoc, 2968 Expr **Args, unsigned NumArgs, 2969 OverloadCandidateSet& CandidateSet, 2970 SourceRange OpRange) { 2971 FunctionSet Functions; 2972 2973 QualType T1 = Args[0]->getType(); 2974 QualType T2; 2975 if (NumArgs > 1) 2976 T2 = Args[1]->getType(); 2977 2978 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 2979 if (S) 2980 LookupOverloadedOperatorName(Op, S, T1, T2, Functions); 2981 ArgumentDependentLookup(OpName, /*Operator*/true, Args, NumArgs, Functions); 2982 AddFunctionCandidates(Functions, Args, NumArgs, CandidateSet); 2983 AddMemberOperatorCandidates(Op, OpLoc, Args, NumArgs, CandidateSet, OpRange); 2984 AddBuiltinOperatorCandidates(Op, OpLoc, Args, NumArgs, CandidateSet); 2985} 2986 2987/// \brief Add overload candidates for overloaded operators that are 2988/// member functions. 2989/// 2990/// Add the overloaded operator candidates that are member functions 2991/// for the operator Op that was used in an operator expression such 2992/// as "x Op y". , Args/NumArgs provides the operator arguments, and 2993/// CandidateSet will store the added overload candidates. (C++ 2994/// [over.match.oper]). 2995void Sema::AddMemberOperatorCandidates(OverloadedOperatorKind Op, 2996 SourceLocation OpLoc, 2997 Expr **Args, unsigned NumArgs, 2998 OverloadCandidateSet& CandidateSet, 2999 SourceRange OpRange) { 3000 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 3001 3002 // C++ [over.match.oper]p3: 3003 // For a unary operator @ with an operand of a type whose 3004 // cv-unqualified version is T1, and for a binary operator @ with 3005 // a left operand of a type whose cv-unqualified version is T1 and 3006 // a right operand of a type whose cv-unqualified version is T2, 3007 // three sets of candidate functions, designated member 3008 // candidates, non-member candidates and built-in candidates, are 3009 // constructed as follows: 3010 QualType T1 = Args[0]->getType(); 3011 QualType T2; 3012 if (NumArgs > 1) 3013 T2 = Args[1]->getType(); 3014 3015 // -- If T1 is a class type, the set of member candidates is the 3016 // result of the qualified lookup of T1::operator@ 3017 // (13.3.1.1.1); otherwise, the set of member candidates is 3018 // empty. 3019 if (const RecordType *T1Rec = T1->getAs<RecordType>()) { 3020 // Complete the type if it can be completed. Otherwise, we're done. 3021 if (RequireCompleteType(OpLoc, T1, PDiag())) 3022 return; 3023 3024 LookupResult Operators(*this, OpName, OpLoc, LookupOrdinaryName); 3025 LookupQualifiedName(Operators, T1Rec->getDecl()); 3026 Operators.suppressDiagnostics(); 3027 3028 for (LookupResult::iterator Oper = Operators.begin(), 3029 OperEnd = Operators.end(); 3030 Oper != OperEnd; 3031 ++Oper) 3032 AddMethodCandidate(*Oper, Args[0]->getType(), 3033 Args + 1, NumArgs - 1, CandidateSet, 3034 /* SuppressUserConversions = */ false); 3035 } 3036} 3037 3038/// AddBuiltinCandidate - Add a candidate for a built-in 3039/// operator. ResultTy and ParamTys are the result and parameter types 3040/// of the built-in candidate, respectively. Args and NumArgs are the 3041/// arguments being passed to the candidate. IsAssignmentOperator 3042/// should be true when this built-in candidate is an assignment 3043/// operator. NumContextualBoolArguments is the number of arguments 3044/// (at the beginning of the argument list) that will be contextually 3045/// converted to bool. 3046void Sema::AddBuiltinCandidate(QualType ResultTy, QualType *ParamTys, 3047 Expr **Args, unsigned NumArgs, 3048 OverloadCandidateSet& CandidateSet, 3049 bool IsAssignmentOperator, 3050 unsigned NumContextualBoolArguments) { 3051 // Overload resolution is always an unevaluated context. 3052 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 3053 3054 // Add this candidate 3055 CandidateSet.push_back(OverloadCandidate()); 3056 OverloadCandidate& Candidate = CandidateSet.back(); 3057 Candidate.Function = 0; 3058 Candidate.IsSurrogate = false; 3059 Candidate.IgnoreObjectArgument = false; 3060 Candidate.BuiltinTypes.ResultTy = ResultTy; 3061 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 3062 Candidate.BuiltinTypes.ParamTypes[ArgIdx] = ParamTys[ArgIdx]; 3063 3064 // Determine the implicit conversion sequences for each of the 3065 // arguments. 3066 Candidate.Viable = true; 3067 Candidate.Conversions.resize(NumArgs); 3068 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 3069 // C++ [over.match.oper]p4: 3070 // For the built-in assignment operators, conversions of the 3071 // left operand are restricted as follows: 3072 // -- no temporaries are introduced to hold the left operand, and 3073 // -- no user-defined conversions are applied to the left 3074 // operand to achieve a type match with the left-most 3075 // parameter of a built-in candidate. 3076 // 3077 // We block these conversions by turning off user-defined 3078 // conversions, since that is the only way that initialization of 3079 // a reference to a non-class type can occur from something that 3080 // is not of the same type. 3081 if (ArgIdx < NumContextualBoolArguments) { 3082 assert(ParamTys[ArgIdx] == Context.BoolTy && 3083 "Contextual conversion to bool requires bool type"); 3084 Candidate.Conversions[ArgIdx] = TryContextuallyConvertToBool(Args[ArgIdx]); 3085 } else { 3086 Candidate.Conversions[ArgIdx] 3087 = TryCopyInitialization(Args[ArgIdx], ParamTys[ArgIdx], 3088 ArgIdx == 0 && IsAssignmentOperator, 3089 /*ForceRValue=*/false, 3090 /*InOverloadResolution=*/false); 3091 } 3092 if (Candidate.Conversions[ArgIdx].isBad()) { 3093 Candidate.Viable = false; 3094 Candidate.FailureKind = ovl_fail_bad_conversion; 3095 break; 3096 } 3097 } 3098} 3099 3100/// BuiltinCandidateTypeSet - A set of types that will be used for the 3101/// candidate operator functions for built-in operators (C++ 3102/// [over.built]). The types are separated into pointer types and 3103/// enumeration types. 3104class BuiltinCandidateTypeSet { 3105 /// TypeSet - A set of types. 3106 typedef llvm::SmallPtrSet<QualType, 8> TypeSet; 3107 3108 /// PointerTypes - The set of pointer types that will be used in the 3109 /// built-in candidates. 3110 TypeSet PointerTypes; 3111 3112 /// MemberPointerTypes - The set of member pointer types that will be 3113 /// used in the built-in candidates. 3114 TypeSet MemberPointerTypes; 3115 3116 /// EnumerationTypes - The set of enumeration types that will be 3117 /// used in the built-in candidates. 3118 TypeSet EnumerationTypes; 3119 3120 /// Sema - The semantic analysis instance where we are building the 3121 /// candidate type set. 3122 Sema &SemaRef; 3123 3124 /// Context - The AST context in which we will build the type sets. 3125 ASTContext &Context; 3126 3127 bool AddPointerWithMoreQualifiedTypeVariants(QualType Ty, 3128 const Qualifiers &VisibleQuals); 3129 bool AddMemberPointerWithMoreQualifiedTypeVariants(QualType Ty); 3130 3131public: 3132 /// iterator - Iterates through the types that are part of the set. 3133 typedef TypeSet::iterator iterator; 3134 3135 BuiltinCandidateTypeSet(Sema &SemaRef) 3136 : SemaRef(SemaRef), Context(SemaRef.Context) { } 3137 3138 void AddTypesConvertedFrom(QualType Ty, 3139 SourceLocation Loc, 3140 bool AllowUserConversions, 3141 bool AllowExplicitConversions, 3142 const Qualifiers &VisibleTypeConversionsQuals); 3143 3144 /// pointer_begin - First pointer type found; 3145 iterator pointer_begin() { return PointerTypes.begin(); } 3146 3147 /// pointer_end - Past the last pointer type found; 3148 iterator pointer_end() { return PointerTypes.end(); } 3149 3150 /// member_pointer_begin - First member pointer type found; 3151 iterator member_pointer_begin() { return MemberPointerTypes.begin(); } 3152 3153 /// member_pointer_end - Past the last member pointer type found; 3154 iterator member_pointer_end() { return MemberPointerTypes.end(); } 3155 3156 /// enumeration_begin - First enumeration type found; 3157 iterator enumeration_begin() { return EnumerationTypes.begin(); } 3158 3159 /// enumeration_end - Past the last enumeration type found; 3160 iterator enumeration_end() { return EnumerationTypes.end(); } 3161}; 3162 3163/// AddPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty to 3164/// the set of pointer types along with any more-qualified variants of 3165/// that type. For example, if @p Ty is "int const *", this routine 3166/// will add "int const *", "int const volatile *", "int const 3167/// restrict *", and "int const volatile restrict *" to the set of 3168/// pointer types. Returns true if the add of @p Ty itself succeeded, 3169/// false otherwise. 3170/// 3171/// FIXME: what to do about extended qualifiers? 3172bool 3173BuiltinCandidateTypeSet::AddPointerWithMoreQualifiedTypeVariants(QualType Ty, 3174 const Qualifiers &VisibleQuals) { 3175 3176 // Insert this type. 3177 if (!PointerTypes.insert(Ty)) 3178 return false; 3179 3180 const PointerType *PointerTy = Ty->getAs<PointerType>(); 3181 assert(PointerTy && "type was not a pointer type!"); 3182 3183 QualType PointeeTy = PointerTy->getPointeeType(); 3184 // Don't add qualified variants of arrays. For one, they're not allowed 3185 // (the qualifier would sink to the element type), and for another, the 3186 // only overload situation where it matters is subscript or pointer +- int, 3187 // and those shouldn't have qualifier variants anyway. 3188 if (PointeeTy->isArrayType()) 3189 return true; 3190 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 3191 if (const ConstantArrayType *Array =Context.getAsConstantArrayType(PointeeTy)) 3192 BaseCVR = Array->getElementType().getCVRQualifiers(); 3193 bool hasVolatile = VisibleQuals.hasVolatile(); 3194 bool hasRestrict = VisibleQuals.hasRestrict(); 3195 3196 // Iterate through all strict supersets of BaseCVR. 3197 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 3198 if ((CVR | BaseCVR) != CVR) continue; 3199 // Skip over Volatile/Restrict if no Volatile/Restrict found anywhere 3200 // in the types. 3201 if ((CVR & Qualifiers::Volatile) && !hasVolatile) continue; 3202 if ((CVR & Qualifiers::Restrict) && !hasRestrict) continue; 3203 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 3204 PointerTypes.insert(Context.getPointerType(QPointeeTy)); 3205 } 3206 3207 return true; 3208} 3209 3210/// AddMemberPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty 3211/// to the set of pointer types along with any more-qualified variants of 3212/// that type. For example, if @p Ty is "int const *", this routine 3213/// will add "int const *", "int const volatile *", "int const 3214/// restrict *", and "int const volatile restrict *" to the set of 3215/// pointer types. Returns true if the add of @p Ty itself succeeded, 3216/// false otherwise. 3217/// 3218/// FIXME: what to do about extended qualifiers? 3219bool 3220BuiltinCandidateTypeSet::AddMemberPointerWithMoreQualifiedTypeVariants( 3221 QualType Ty) { 3222 // Insert this type. 3223 if (!MemberPointerTypes.insert(Ty)) 3224 return false; 3225 3226 const MemberPointerType *PointerTy = Ty->getAs<MemberPointerType>(); 3227 assert(PointerTy && "type was not a member pointer type!"); 3228 3229 QualType PointeeTy = PointerTy->getPointeeType(); 3230 // Don't add qualified variants of arrays. For one, they're not allowed 3231 // (the qualifier would sink to the element type), and for another, the 3232 // only overload situation where it matters is subscript or pointer +- int, 3233 // and those shouldn't have qualifier variants anyway. 3234 if (PointeeTy->isArrayType()) 3235 return true; 3236 const Type *ClassTy = PointerTy->getClass(); 3237 3238 // Iterate through all strict supersets of the pointee type's CVR 3239 // qualifiers. 3240 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 3241 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 3242 if ((CVR | BaseCVR) != CVR) continue; 3243 3244 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 3245 MemberPointerTypes.insert(Context.getMemberPointerType(QPointeeTy, ClassTy)); 3246 } 3247 3248 return true; 3249} 3250 3251/// AddTypesConvertedFrom - Add each of the types to which the type @p 3252/// Ty can be implicit converted to the given set of @p Types. We're 3253/// primarily interested in pointer types and enumeration types. We also 3254/// take member pointer types, for the conditional operator. 3255/// AllowUserConversions is true if we should look at the conversion 3256/// functions of a class type, and AllowExplicitConversions if we 3257/// should also include the explicit conversion functions of a class 3258/// type. 3259void 3260BuiltinCandidateTypeSet::AddTypesConvertedFrom(QualType Ty, 3261 SourceLocation Loc, 3262 bool AllowUserConversions, 3263 bool AllowExplicitConversions, 3264 const Qualifiers &VisibleQuals) { 3265 // Only deal with canonical types. 3266 Ty = Context.getCanonicalType(Ty); 3267 3268 // Look through reference types; they aren't part of the type of an 3269 // expression for the purposes of conversions. 3270 if (const ReferenceType *RefTy = Ty->getAs<ReferenceType>()) 3271 Ty = RefTy->getPointeeType(); 3272 3273 // We don't care about qualifiers on the type. 3274 Ty = Ty.getLocalUnqualifiedType(); 3275 3276 // If we're dealing with an array type, decay to the pointer. 3277 if (Ty->isArrayType()) 3278 Ty = SemaRef.Context.getArrayDecayedType(Ty); 3279 3280 if (const PointerType *PointerTy = Ty->getAs<PointerType>()) { 3281 QualType PointeeTy = PointerTy->getPointeeType(); 3282 3283 // Insert our type, and its more-qualified variants, into the set 3284 // of types. 3285 if (!AddPointerWithMoreQualifiedTypeVariants(Ty, VisibleQuals)) 3286 return; 3287 } else if (Ty->isMemberPointerType()) { 3288 // Member pointers are far easier, since the pointee can't be converted. 3289 if (!AddMemberPointerWithMoreQualifiedTypeVariants(Ty)) 3290 return; 3291 } else if (Ty->isEnumeralType()) { 3292 EnumerationTypes.insert(Ty); 3293 } else if (AllowUserConversions) { 3294 if (const RecordType *TyRec = Ty->getAs<RecordType>()) { 3295 if (SemaRef.RequireCompleteType(Loc, Ty, 0)) { 3296 // No conversion functions in incomplete types. 3297 return; 3298 } 3299 3300 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 3301 const UnresolvedSetImpl *Conversions 3302 = ClassDecl->getVisibleConversionFunctions(); 3303 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 3304 E = Conversions->end(); I != E; ++I) { 3305 3306 // Skip conversion function templates; they don't tell us anything 3307 // about which builtin types we can convert to. 3308 if (isa<FunctionTemplateDecl>(*I)) 3309 continue; 3310 3311 CXXConversionDecl *Conv = cast<CXXConversionDecl>(*I); 3312 if (AllowExplicitConversions || !Conv->isExplicit()) { 3313 AddTypesConvertedFrom(Conv->getConversionType(), Loc, false, false, 3314 VisibleQuals); 3315 } 3316 } 3317 } 3318 } 3319} 3320 3321/// \brief Helper function for AddBuiltinOperatorCandidates() that adds 3322/// the volatile- and non-volatile-qualified assignment operators for the 3323/// given type to the candidate set. 3324static void AddBuiltinAssignmentOperatorCandidates(Sema &S, 3325 QualType T, 3326 Expr **Args, 3327 unsigned NumArgs, 3328 OverloadCandidateSet &CandidateSet) { 3329 QualType ParamTypes[2]; 3330 3331 // T& operator=(T&, T) 3332 ParamTypes[0] = S.Context.getLValueReferenceType(T); 3333 ParamTypes[1] = T; 3334 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3335 /*IsAssignmentOperator=*/true); 3336 3337 if (!S.Context.getCanonicalType(T).isVolatileQualified()) { 3338 // volatile T& operator=(volatile T&, T) 3339 ParamTypes[0] 3340 = S.Context.getLValueReferenceType(S.Context.getVolatileType(T)); 3341 ParamTypes[1] = T; 3342 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3343 /*IsAssignmentOperator=*/true); 3344 } 3345} 3346 3347/// CollectVRQualifiers - This routine returns Volatile/Restrict qualifiers, 3348/// if any, found in visible type conversion functions found in ArgExpr's type. 3349static Qualifiers CollectVRQualifiers(ASTContext &Context, Expr* ArgExpr) { 3350 Qualifiers VRQuals; 3351 const RecordType *TyRec; 3352 if (const MemberPointerType *RHSMPType = 3353 ArgExpr->getType()->getAs<MemberPointerType>()) 3354 TyRec = cast<RecordType>(RHSMPType->getClass()); 3355 else 3356 TyRec = ArgExpr->getType()->getAs<RecordType>(); 3357 if (!TyRec) { 3358 // Just to be safe, assume the worst case. 3359 VRQuals.addVolatile(); 3360 VRQuals.addRestrict(); 3361 return VRQuals; 3362 } 3363 3364 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 3365 const UnresolvedSetImpl *Conversions = 3366 ClassDecl->getVisibleConversionFunctions(); 3367 3368 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 3369 E = Conversions->end(); I != E; ++I) { 3370 if (CXXConversionDecl *Conv = dyn_cast<CXXConversionDecl>(*I)) { 3371 QualType CanTy = Context.getCanonicalType(Conv->getConversionType()); 3372 if (const ReferenceType *ResTypeRef = CanTy->getAs<ReferenceType>()) 3373 CanTy = ResTypeRef->getPointeeType(); 3374 // Need to go down the pointer/mempointer chain and add qualifiers 3375 // as see them. 3376 bool done = false; 3377 while (!done) { 3378 if (const PointerType *ResTypePtr = CanTy->getAs<PointerType>()) 3379 CanTy = ResTypePtr->getPointeeType(); 3380 else if (const MemberPointerType *ResTypeMPtr = 3381 CanTy->getAs<MemberPointerType>()) 3382 CanTy = ResTypeMPtr->getPointeeType(); 3383 else 3384 done = true; 3385 if (CanTy.isVolatileQualified()) 3386 VRQuals.addVolatile(); 3387 if (CanTy.isRestrictQualified()) 3388 VRQuals.addRestrict(); 3389 if (VRQuals.hasRestrict() && VRQuals.hasVolatile()) 3390 return VRQuals; 3391 } 3392 } 3393 } 3394 return VRQuals; 3395} 3396 3397/// AddBuiltinOperatorCandidates - Add the appropriate built-in 3398/// operator overloads to the candidate set (C++ [over.built]), based 3399/// on the operator @p Op and the arguments given. For example, if the 3400/// operator is a binary '+', this routine might add "int 3401/// operator+(int, int)" to cover integer addition. 3402void 3403Sema::AddBuiltinOperatorCandidates(OverloadedOperatorKind Op, 3404 SourceLocation OpLoc, 3405 Expr **Args, unsigned NumArgs, 3406 OverloadCandidateSet& CandidateSet) { 3407 // The set of "promoted arithmetic types", which are the arithmetic 3408 // types are that preserved by promotion (C++ [over.built]p2). Note 3409 // that the first few of these types are the promoted integral 3410 // types; these types need to be first. 3411 // FIXME: What about complex? 3412 const unsigned FirstIntegralType = 0; 3413 const unsigned LastIntegralType = 13; 3414 const unsigned FirstPromotedIntegralType = 7, 3415 LastPromotedIntegralType = 13; 3416 const unsigned FirstPromotedArithmeticType = 7, 3417 LastPromotedArithmeticType = 16; 3418 const unsigned NumArithmeticTypes = 16; 3419 QualType ArithmeticTypes[NumArithmeticTypes] = { 3420 Context.BoolTy, Context.CharTy, Context.WCharTy, 3421// FIXME: Context.Char16Ty, Context.Char32Ty, 3422 Context.SignedCharTy, Context.ShortTy, 3423 Context.UnsignedCharTy, Context.UnsignedShortTy, 3424 Context.IntTy, Context.LongTy, Context.LongLongTy, 3425 Context.UnsignedIntTy, Context.UnsignedLongTy, Context.UnsignedLongLongTy, 3426 Context.FloatTy, Context.DoubleTy, Context.LongDoubleTy 3427 }; 3428 assert(ArithmeticTypes[FirstPromotedIntegralType] == Context.IntTy && 3429 "Invalid first promoted integral type"); 3430 assert(ArithmeticTypes[LastPromotedIntegralType - 1] 3431 == Context.UnsignedLongLongTy && 3432 "Invalid last promoted integral type"); 3433 assert(ArithmeticTypes[FirstPromotedArithmeticType] == Context.IntTy && 3434 "Invalid first promoted arithmetic type"); 3435 assert(ArithmeticTypes[LastPromotedArithmeticType - 1] 3436 == Context.LongDoubleTy && 3437 "Invalid last promoted arithmetic type"); 3438 3439 // Find all of the types that the arguments can convert to, but only 3440 // if the operator we're looking at has built-in operator candidates 3441 // that make use of these types. 3442 Qualifiers VisibleTypeConversionsQuals; 3443 VisibleTypeConversionsQuals.addConst(); 3444 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 3445 VisibleTypeConversionsQuals += CollectVRQualifiers(Context, Args[ArgIdx]); 3446 3447 BuiltinCandidateTypeSet CandidateTypes(*this); 3448 if (Op == OO_Less || Op == OO_Greater || Op == OO_LessEqual || 3449 Op == OO_GreaterEqual || Op == OO_EqualEqual || Op == OO_ExclaimEqual || 3450 Op == OO_Plus || (Op == OO_Minus && NumArgs == 2) || Op == OO_Equal || 3451 Op == OO_PlusEqual || Op == OO_MinusEqual || Op == OO_Subscript || 3452 Op == OO_ArrowStar || Op == OO_PlusPlus || Op == OO_MinusMinus || 3453 (Op == OO_Star && NumArgs == 1) || Op == OO_Conditional) { 3454 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 3455 CandidateTypes.AddTypesConvertedFrom(Args[ArgIdx]->getType(), 3456 OpLoc, 3457 true, 3458 (Op == OO_Exclaim || 3459 Op == OO_AmpAmp || 3460 Op == OO_PipePipe), 3461 VisibleTypeConversionsQuals); 3462 } 3463 3464 bool isComparison = false; 3465 switch (Op) { 3466 case OO_None: 3467 case NUM_OVERLOADED_OPERATORS: 3468 assert(false && "Expected an overloaded operator"); 3469 break; 3470 3471 case OO_Star: // '*' is either unary or binary 3472 if (NumArgs == 1) 3473 goto UnaryStar; 3474 else 3475 goto BinaryStar; 3476 break; 3477 3478 case OO_Plus: // '+' is either unary or binary 3479 if (NumArgs == 1) 3480 goto UnaryPlus; 3481 else 3482 goto BinaryPlus; 3483 break; 3484 3485 case OO_Minus: // '-' is either unary or binary 3486 if (NumArgs == 1) 3487 goto UnaryMinus; 3488 else 3489 goto BinaryMinus; 3490 break; 3491 3492 case OO_Amp: // '&' is either unary or binary 3493 if (NumArgs == 1) 3494 goto UnaryAmp; 3495 else 3496 goto BinaryAmp; 3497 3498 case OO_PlusPlus: 3499 case OO_MinusMinus: 3500 // C++ [over.built]p3: 3501 // 3502 // For every pair (T, VQ), where T is an arithmetic type, and VQ 3503 // is either volatile or empty, there exist candidate operator 3504 // functions of the form 3505 // 3506 // VQ T& operator++(VQ T&); 3507 // T operator++(VQ T&, int); 3508 // 3509 // C++ [over.built]p4: 3510 // 3511 // For every pair (T, VQ), where T is an arithmetic type other 3512 // than bool, and VQ is either volatile or empty, there exist 3513 // candidate operator functions of the form 3514 // 3515 // VQ T& operator--(VQ T&); 3516 // T operator--(VQ T&, int); 3517 for (unsigned Arith = (Op == OO_PlusPlus? 0 : 1); 3518 Arith < NumArithmeticTypes; ++Arith) { 3519 QualType ArithTy = ArithmeticTypes[Arith]; 3520 QualType ParamTypes[2] 3521 = { Context.getLValueReferenceType(ArithTy), Context.IntTy }; 3522 3523 // Non-volatile version. 3524 if (NumArgs == 1) 3525 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3526 else 3527 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 3528 // heuristic to reduce number of builtin candidates in the set. 3529 // Add volatile version only if there are conversions to a volatile type. 3530 if (VisibleTypeConversionsQuals.hasVolatile()) { 3531 // Volatile version 3532 ParamTypes[0] 3533 = Context.getLValueReferenceType(Context.getVolatileType(ArithTy)); 3534 if (NumArgs == 1) 3535 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3536 else 3537 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 3538 } 3539 } 3540 3541 // C++ [over.built]p5: 3542 // 3543 // For every pair (T, VQ), where T is a cv-qualified or 3544 // cv-unqualified object type, and VQ is either volatile or 3545 // empty, there exist candidate operator functions of the form 3546 // 3547 // T*VQ& operator++(T*VQ&); 3548 // T*VQ& operator--(T*VQ&); 3549 // T* operator++(T*VQ&, int); 3550 // T* operator--(T*VQ&, int); 3551 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3552 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3553 // Skip pointer types that aren't pointers to object types. 3554 if (!(*Ptr)->getAs<PointerType>()->getPointeeType()->isObjectType()) 3555 continue; 3556 3557 QualType ParamTypes[2] = { 3558 Context.getLValueReferenceType(*Ptr), Context.IntTy 3559 }; 3560 3561 // Without volatile 3562 if (NumArgs == 1) 3563 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3564 else 3565 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3566 3567 if (!Context.getCanonicalType(*Ptr).isVolatileQualified() && 3568 VisibleTypeConversionsQuals.hasVolatile()) { 3569 // With volatile 3570 ParamTypes[0] 3571 = Context.getLValueReferenceType(Context.getVolatileType(*Ptr)); 3572 if (NumArgs == 1) 3573 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3574 else 3575 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3576 } 3577 } 3578 break; 3579 3580 UnaryStar: 3581 // C++ [over.built]p6: 3582 // For every cv-qualified or cv-unqualified object type T, there 3583 // exist candidate operator functions of the form 3584 // 3585 // T& operator*(T*); 3586 // 3587 // C++ [over.built]p7: 3588 // For every function type T, there exist candidate operator 3589 // functions of the form 3590 // T& operator*(T*); 3591 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3592 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3593 QualType ParamTy = *Ptr; 3594 QualType PointeeTy = ParamTy->getAs<PointerType>()->getPointeeType(); 3595 AddBuiltinCandidate(Context.getLValueReferenceType(PointeeTy), 3596 &ParamTy, Args, 1, CandidateSet); 3597 } 3598 break; 3599 3600 UnaryPlus: 3601 // C++ [over.built]p8: 3602 // For every type T, there exist candidate operator functions of 3603 // the form 3604 // 3605 // T* operator+(T*); 3606 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3607 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3608 QualType ParamTy = *Ptr; 3609 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet); 3610 } 3611 3612 // Fall through 3613 3614 UnaryMinus: 3615 // C++ [over.built]p9: 3616 // For every promoted arithmetic type T, there exist candidate 3617 // operator functions of the form 3618 // 3619 // T operator+(T); 3620 // T operator-(T); 3621 for (unsigned Arith = FirstPromotedArithmeticType; 3622 Arith < LastPromotedArithmeticType; ++Arith) { 3623 QualType ArithTy = ArithmeticTypes[Arith]; 3624 AddBuiltinCandidate(ArithTy, &ArithTy, Args, 1, CandidateSet); 3625 } 3626 break; 3627 3628 case OO_Tilde: 3629 // C++ [over.built]p10: 3630 // For every promoted integral type T, there exist candidate 3631 // operator functions of the form 3632 // 3633 // T operator~(T); 3634 for (unsigned Int = FirstPromotedIntegralType; 3635 Int < LastPromotedIntegralType; ++Int) { 3636 QualType IntTy = ArithmeticTypes[Int]; 3637 AddBuiltinCandidate(IntTy, &IntTy, Args, 1, CandidateSet); 3638 } 3639 break; 3640 3641 case OO_New: 3642 case OO_Delete: 3643 case OO_Array_New: 3644 case OO_Array_Delete: 3645 case OO_Call: 3646 assert(false && "Special operators don't use AddBuiltinOperatorCandidates"); 3647 break; 3648 3649 case OO_Comma: 3650 UnaryAmp: 3651 case OO_Arrow: 3652 // C++ [over.match.oper]p3: 3653 // -- For the operator ',', the unary operator '&', or the 3654 // operator '->', the built-in candidates set is empty. 3655 break; 3656 3657 case OO_EqualEqual: 3658 case OO_ExclaimEqual: 3659 // C++ [over.match.oper]p16: 3660 // For every pointer to member type T, there exist candidate operator 3661 // functions of the form 3662 // 3663 // bool operator==(T,T); 3664 // bool operator!=(T,T); 3665 for (BuiltinCandidateTypeSet::iterator 3666 MemPtr = CandidateTypes.member_pointer_begin(), 3667 MemPtrEnd = CandidateTypes.member_pointer_end(); 3668 MemPtr != MemPtrEnd; 3669 ++MemPtr) { 3670 QualType ParamTypes[2] = { *MemPtr, *MemPtr }; 3671 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 3672 } 3673 3674 // Fall through 3675 3676 case OO_Less: 3677 case OO_Greater: 3678 case OO_LessEqual: 3679 case OO_GreaterEqual: 3680 // C++ [over.built]p15: 3681 // 3682 // For every pointer or enumeration type T, there exist 3683 // candidate operator functions of the form 3684 // 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 // bool operator!=(T, T); 3691 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3692 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3693 QualType ParamTypes[2] = { *Ptr, *Ptr }; 3694 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 3695 } 3696 for (BuiltinCandidateTypeSet::iterator Enum 3697 = CandidateTypes.enumeration_begin(); 3698 Enum != CandidateTypes.enumeration_end(); ++Enum) { 3699 QualType ParamTypes[2] = { *Enum, *Enum }; 3700 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 3701 } 3702 3703 // Fall through. 3704 isComparison = true; 3705 3706 BinaryPlus: 3707 BinaryMinus: 3708 if (!isComparison) { 3709 // We didn't fall through, so we must have OO_Plus or OO_Minus. 3710 3711 // C++ [over.built]p13: 3712 // 3713 // For every cv-qualified or cv-unqualified object type T 3714 // there exist candidate operator functions of the form 3715 // 3716 // T* operator+(T*, ptrdiff_t); 3717 // T& operator[](T*, ptrdiff_t); [BELOW] 3718 // T* operator-(T*, ptrdiff_t); 3719 // T* operator+(ptrdiff_t, T*); 3720 // T& operator[](ptrdiff_t, T*); [BELOW] 3721 // 3722 // C++ [over.built]p14: 3723 // 3724 // For every T, where T is a pointer to object type, there 3725 // exist candidate operator functions of the form 3726 // 3727 // ptrdiff_t operator-(T, T); 3728 for (BuiltinCandidateTypeSet::iterator Ptr 3729 = CandidateTypes.pointer_begin(); 3730 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3731 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 3732 3733 // operator+(T*, ptrdiff_t) or operator-(T*, ptrdiff_t) 3734 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3735 3736 if (Op == OO_Plus) { 3737 // T* operator+(ptrdiff_t, T*); 3738 ParamTypes[0] = ParamTypes[1]; 3739 ParamTypes[1] = *Ptr; 3740 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3741 } else { 3742 // ptrdiff_t operator-(T, T); 3743 ParamTypes[1] = *Ptr; 3744 AddBuiltinCandidate(Context.getPointerDiffType(), ParamTypes, 3745 Args, 2, CandidateSet); 3746 } 3747 } 3748 } 3749 // Fall through 3750 3751 case OO_Slash: 3752 BinaryStar: 3753 Conditional: 3754 // C++ [over.built]p12: 3755 // 3756 // For every pair of promoted arithmetic types L and R, there 3757 // exist candidate operator functions of the form 3758 // 3759 // LR operator*(L, R); 3760 // LR operator/(L, R); 3761 // LR operator+(L, R); 3762 // LR 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 // bool operator!=(L, R); 3769 // 3770 // where LR is the result of the usual arithmetic conversions 3771 // between types L and R. 3772 // 3773 // C++ [over.built]p24: 3774 // 3775 // For every pair of promoted arithmetic types L and R, there exist 3776 // candidate operator functions of the form 3777 // 3778 // LR operator?(bool, L, R); 3779 // 3780 // where LR is the result of the usual arithmetic conversions 3781 // between types L and R. 3782 // Our candidates ignore the first parameter. 3783 for (unsigned Left = FirstPromotedArithmeticType; 3784 Left < LastPromotedArithmeticType; ++Left) { 3785 for (unsigned Right = FirstPromotedArithmeticType; 3786 Right < LastPromotedArithmeticType; ++Right) { 3787 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 3788 QualType Result 3789 = isComparison 3790 ? Context.BoolTy 3791 : Context.UsualArithmeticConversionsType(LandR[0], LandR[1]); 3792 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 3793 } 3794 } 3795 break; 3796 3797 case OO_Percent: 3798 BinaryAmp: 3799 case OO_Caret: 3800 case OO_Pipe: 3801 case OO_LessLess: 3802 case OO_GreaterGreater: 3803 // C++ [over.built]p17: 3804 // 3805 // For every pair of promoted integral types L and R, there 3806 // exist candidate operator functions of the form 3807 // 3808 // LR operator%(L, R); 3809 // LR operator&(L, R); 3810 // LR operator^(L, R); 3811 // LR operator|(L, R); 3812 // L operator<<(L, R); 3813 // L operator>>(L, R); 3814 // 3815 // where LR is the result of the usual arithmetic conversions 3816 // between types L and R. 3817 for (unsigned Left = FirstPromotedIntegralType; 3818 Left < LastPromotedIntegralType; ++Left) { 3819 for (unsigned Right = FirstPromotedIntegralType; 3820 Right < LastPromotedIntegralType; ++Right) { 3821 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 3822 QualType Result = (Op == OO_LessLess || Op == OO_GreaterGreater) 3823 ? LandR[0] 3824 : Context.UsualArithmeticConversionsType(LandR[0], LandR[1]); 3825 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 3826 } 3827 } 3828 break; 3829 3830 case OO_Equal: 3831 // C++ [over.built]p20: 3832 // 3833 // For every pair (T, VQ), where T is an enumeration or 3834 // pointer to member type and VQ is either volatile or 3835 // empty, there exist candidate operator functions of the form 3836 // 3837 // VQ T& operator=(VQ T&, T); 3838 for (BuiltinCandidateTypeSet::iterator 3839 Enum = CandidateTypes.enumeration_begin(), 3840 EnumEnd = CandidateTypes.enumeration_end(); 3841 Enum != EnumEnd; ++Enum) 3842 AddBuiltinAssignmentOperatorCandidates(*this, *Enum, Args, 2, 3843 CandidateSet); 3844 for (BuiltinCandidateTypeSet::iterator 3845 MemPtr = CandidateTypes.member_pointer_begin(), 3846 MemPtrEnd = CandidateTypes.member_pointer_end(); 3847 MemPtr != MemPtrEnd; ++MemPtr) 3848 AddBuiltinAssignmentOperatorCandidates(*this, *MemPtr, Args, 2, 3849 CandidateSet); 3850 // Fall through. 3851 3852 case OO_PlusEqual: 3853 case OO_MinusEqual: 3854 // C++ [over.built]p19: 3855 // 3856 // For every pair (T, VQ), where T is any type and VQ is either 3857 // volatile or empty, there exist candidate operator functions 3858 // of the form 3859 // 3860 // T*VQ& operator=(T*VQ&, T*); 3861 // 3862 // C++ [over.built]p21: 3863 // 3864 // For every pair (T, VQ), where T is a cv-qualified or 3865 // cv-unqualified object type and VQ is either volatile or 3866 // empty, there exist candidate operator functions of the form 3867 // 3868 // T*VQ& operator+=(T*VQ&, ptrdiff_t); 3869 // T*VQ& operator-=(T*VQ&, ptrdiff_t); 3870 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3871 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3872 QualType ParamTypes[2]; 3873 ParamTypes[1] = (Op == OO_Equal)? *Ptr : Context.getPointerDiffType(); 3874 3875 // non-volatile version 3876 ParamTypes[0] = Context.getLValueReferenceType(*Ptr); 3877 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3878 /*IsAssigmentOperator=*/Op == OO_Equal); 3879 3880 if (!Context.getCanonicalType(*Ptr).isVolatileQualified() && 3881 VisibleTypeConversionsQuals.hasVolatile()) { 3882 // volatile version 3883 ParamTypes[0] 3884 = Context.getLValueReferenceType(Context.getVolatileType(*Ptr)); 3885 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3886 /*IsAssigmentOperator=*/Op == OO_Equal); 3887 } 3888 } 3889 // Fall through. 3890 3891 case OO_StarEqual: 3892 case OO_SlashEqual: 3893 // C++ [over.built]p18: 3894 // 3895 // For every triple (L, VQ, R), where L is an arithmetic type, 3896 // VQ is either volatile or empty, and R is a promoted 3897 // arithmetic type, there exist candidate operator functions of 3898 // the form 3899 // 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 // VQ L& operator-=(VQ L&, R); 3905 for (unsigned Left = 0; Left < NumArithmeticTypes; ++Left) { 3906 for (unsigned Right = FirstPromotedArithmeticType; 3907 Right < LastPromotedArithmeticType; ++Right) { 3908 QualType ParamTypes[2]; 3909 ParamTypes[1] = ArithmeticTypes[Right]; 3910 3911 // Add this built-in operator as a candidate (VQ is empty). 3912 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 3913 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3914 /*IsAssigmentOperator=*/Op == OO_Equal); 3915 3916 // Add this built-in operator as a candidate (VQ is 'volatile'). 3917 if (VisibleTypeConversionsQuals.hasVolatile()) { 3918 ParamTypes[0] = Context.getVolatileType(ArithmeticTypes[Left]); 3919 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 3920 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3921 /*IsAssigmentOperator=*/Op == OO_Equal); 3922 } 3923 } 3924 } 3925 break; 3926 3927 case OO_PercentEqual: 3928 case OO_LessLessEqual: 3929 case OO_GreaterGreaterEqual: 3930 case OO_AmpEqual: 3931 case OO_CaretEqual: 3932 case OO_PipeEqual: 3933 // C++ [over.built]p22: 3934 // 3935 // For every triple (L, VQ, R), where L is an integral type, VQ 3936 // is either volatile or empty, and R is a promoted integral 3937 // type, there exist candidate operator functions of the form 3938 // 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 // VQ L& operator|=(VQ L&, R); 3945 for (unsigned Left = FirstIntegralType; Left < LastIntegralType; ++Left) { 3946 for (unsigned Right = FirstPromotedIntegralType; 3947 Right < LastPromotedIntegralType; ++Right) { 3948 QualType ParamTypes[2]; 3949 ParamTypes[1] = ArithmeticTypes[Right]; 3950 3951 // Add this built-in operator as a candidate (VQ is empty). 3952 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 3953 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 3954 if (VisibleTypeConversionsQuals.hasVolatile()) { 3955 // Add this built-in operator as a candidate (VQ is 'volatile'). 3956 ParamTypes[0] = ArithmeticTypes[Left]; 3957 ParamTypes[0] = Context.getVolatileType(ParamTypes[0]); 3958 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 3959 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 3960 } 3961 } 3962 } 3963 break; 3964 3965 case OO_Exclaim: { 3966 // C++ [over.operator]p23: 3967 // 3968 // There also exist candidate operator functions of the form 3969 // 3970 // bool operator!(bool); 3971 // bool operator&&(bool, bool); [BELOW] 3972 // bool operator||(bool, bool); [BELOW] 3973 QualType ParamTy = Context.BoolTy; 3974 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet, 3975 /*IsAssignmentOperator=*/false, 3976 /*NumContextualBoolArguments=*/1); 3977 break; 3978 } 3979 3980 case OO_AmpAmp: 3981 case OO_PipePipe: { 3982 // C++ [over.operator]p23: 3983 // 3984 // There also exist candidate operator functions of the form 3985 // 3986 // bool operator!(bool); [ABOVE] 3987 // bool operator&&(bool, bool); 3988 // bool operator||(bool, bool); 3989 QualType ParamTypes[2] = { Context.BoolTy, Context.BoolTy }; 3990 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet, 3991 /*IsAssignmentOperator=*/false, 3992 /*NumContextualBoolArguments=*/2); 3993 break; 3994 } 3995 3996 case OO_Subscript: 3997 // C++ [over.built]p13: 3998 // 3999 // For every cv-qualified or cv-unqualified object type T there 4000 // exist candidate operator functions of the form 4001 // 4002 // T* operator+(T*, ptrdiff_t); [ABOVE] 4003 // T& operator[](T*, ptrdiff_t); 4004 // T* operator-(T*, ptrdiff_t); [ABOVE] 4005 // T* operator+(ptrdiff_t, T*); [ABOVE] 4006 // T& operator[](ptrdiff_t, T*); 4007 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 4008 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4009 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 4010 QualType PointeeType = (*Ptr)->getAs<PointerType>()->getPointeeType(); 4011 QualType ResultTy = Context.getLValueReferenceType(PointeeType); 4012 4013 // T& operator[](T*, ptrdiff_t) 4014 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 4015 4016 // T& operator[](ptrdiff_t, T*); 4017 ParamTypes[0] = ParamTypes[1]; 4018 ParamTypes[1] = *Ptr; 4019 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 4020 } 4021 break; 4022 4023 case OO_ArrowStar: 4024 // C++ [over.built]p11: 4025 // For every quintuple (C1, C2, T, CV1, CV2), where C2 is a class type, 4026 // C1 is the same type as C2 or is a derived class of C2, T is an object 4027 // type or a function type, and CV1 and CV2 are cv-qualifier-seqs, 4028 // there exist candidate operator functions of the form 4029 // CV12 T& operator->*(CV1 C1*, CV2 T C2::*); 4030 // where CV12 is the union of CV1 and CV2. 4031 { 4032 for (BuiltinCandidateTypeSet::iterator Ptr = 4033 CandidateTypes.pointer_begin(); 4034 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4035 QualType C1Ty = (*Ptr); 4036 QualType C1; 4037 QualifierCollector Q1; 4038 if (const PointerType *PointerTy = C1Ty->getAs<PointerType>()) { 4039 C1 = QualType(Q1.strip(PointerTy->getPointeeType()), 0); 4040 if (!isa<RecordType>(C1)) 4041 continue; 4042 // heuristic to reduce number of builtin candidates in the set. 4043 // Add volatile/restrict version only if there are conversions to a 4044 // volatile/restrict type. 4045 if (!VisibleTypeConversionsQuals.hasVolatile() && Q1.hasVolatile()) 4046 continue; 4047 if (!VisibleTypeConversionsQuals.hasRestrict() && Q1.hasRestrict()) 4048 continue; 4049 } 4050 for (BuiltinCandidateTypeSet::iterator 4051 MemPtr = CandidateTypes.member_pointer_begin(), 4052 MemPtrEnd = CandidateTypes.member_pointer_end(); 4053 MemPtr != MemPtrEnd; ++MemPtr) { 4054 const MemberPointerType *mptr = cast<MemberPointerType>(*MemPtr); 4055 QualType C2 = QualType(mptr->getClass(), 0); 4056 C2 = C2.getUnqualifiedType(); 4057 if (C1 != C2 && !IsDerivedFrom(C1, C2)) 4058 break; 4059 QualType ParamTypes[2] = { *Ptr, *MemPtr }; 4060 // build CV12 T& 4061 QualType T = mptr->getPointeeType(); 4062 if (!VisibleTypeConversionsQuals.hasVolatile() && 4063 T.isVolatileQualified()) 4064 continue; 4065 if (!VisibleTypeConversionsQuals.hasRestrict() && 4066 T.isRestrictQualified()) 4067 continue; 4068 T = Q1.apply(T); 4069 QualType ResultTy = Context.getLValueReferenceType(T); 4070 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 4071 } 4072 } 4073 } 4074 break; 4075 4076 case OO_Conditional: 4077 // Note that we don't consider the first argument, since it has been 4078 // contextually converted to bool long ago. The candidates below are 4079 // therefore added as binary. 4080 // 4081 // C++ [over.built]p24: 4082 // For every type T, where T is a pointer or pointer-to-member type, 4083 // there exist candidate operator functions of the form 4084 // 4085 // T operator?(bool, T, T); 4086 // 4087 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(), 4088 E = CandidateTypes.pointer_end(); Ptr != E; ++Ptr) { 4089 QualType ParamTypes[2] = { *Ptr, *Ptr }; 4090 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 4091 } 4092 for (BuiltinCandidateTypeSet::iterator Ptr = 4093 CandidateTypes.member_pointer_begin(), 4094 E = CandidateTypes.member_pointer_end(); Ptr != E; ++Ptr) { 4095 QualType ParamTypes[2] = { *Ptr, *Ptr }; 4096 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 4097 } 4098 goto Conditional; 4099 } 4100} 4101 4102/// \brief Add function candidates found via argument-dependent lookup 4103/// to the set of overloading candidates. 4104/// 4105/// This routine performs argument-dependent name lookup based on the 4106/// given function name (which may also be an operator name) and adds 4107/// all of the overload candidates found by ADL to the overload 4108/// candidate set (C++ [basic.lookup.argdep]). 4109void 4110Sema::AddArgumentDependentLookupCandidates(DeclarationName Name, 4111 Expr **Args, unsigned NumArgs, 4112 const TemplateArgumentListInfo *ExplicitTemplateArgs, 4113 OverloadCandidateSet& CandidateSet, 4114 bool PartialOverloading) { 4115 FunctionSet Functions; 4116 4117 // FIXME: Should we be trafficking in canonical function decls throughout? 4118 4119 // Record all of the function candidates that we've already 4120 // added to the overload set, so that we don't add those same 4121 // candidates a second time. 4122 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 4123 CandEnd = CandidateSet.end(); 4124 Cand != CandEnd; ++Cand) 4125 if (Cand->Function) { 4126 Functions.insert(Cand->Function); 4127 if (FunctionTemplateDecl *FunTmpl = Cand->Function->getPrimaryTemplate()) 4128 Functions.insert(FunTmpl); 4129 } 4130 4131 // FIXME: Pass in the explicit template arguments? 4132 ArgumentDependentLookup(Name, /*Operator*/false, Args, NumArgs, Functions); 4133 4134 // Erase all of the candidates we already knew about. 4135 // FIXME: This is suboptimal. Is there a better way? 4136 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 4137 CandEnd = CandidateSet.end(); 4138 Cand != CandEnd; ++Cand) 4139 if (Cand->Function) { 4140 Functions.erase(Cand->Function); 4141 if (FunctionTemplateDecl *FunTmpl = Cand->Function->getPrimaryTemplate()) 4142 Functions.erase(FunTmpl); 4143 } 4144 4145 // For each of the ADL candidates we found, add it to the overload 4146 // set. 4147 for (FunctionSet::iterator Func = Functions.begin(), 4148 FuncEnd = Functions.end(); 4149 Func != FuncEnd; ++Func) { 4150 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*Func)) { 4151 if (ExplicitTemplateArgs) 4152 continue; 4153 4154 AddOverloadCandidate(FD, Args, NumArgs, CandidateSet, 4155 false, false, PartialOverloading); 4156 } else 4157 AddTemplateOverloadCandidate(cast<FunctionTemplateDecl>(*Func), 4158 ExplicitTemplateArgs, 4159 Args, NumArgs, CandidateSet); 4160 } 4161} 4162 4163/// isBetterOverloadCandidate - Determines whether the first overload 4164/// candidate is a better candidate than the second (C++ 13.3.3p1). 4165bool 4166Sema::isBetterOverloadCandidate(const OverloadCandidate& Cand1, 4167 const OverloadCandidate& Cand2) { 4168 // Define viable functions to be better candidates than non-viable 4169 // functions. 4170 if (!Cand2.Viable) 4171 return Cand1.Viable; 4172 else if (!Cand1.Viable) 4173 return false; 4174 4175 // C++ [over.match.best]p1: 4176 // 4177 // -- if F is a static member function, ICS1(F) is defined such 4178 // that ICS1(F) is neither better nor worse than ICS1(G) for 4179 // any function G, and, symmetrically, ICS1(G) is neither 4180 // better nor worse than ICS1(F). 4181 unsigned StartArg = 0; 4182 if (Cand1.IgnoreObjectArgument || Cand2.IgnoreObjectArgument) 4183 StartArg = 1; 4184 4185 // C++ [over.match.best]p1: 4186 // A viable function F1 is defined to be a better function than another 4187 // viable function F2 if for all arguments i, ICSi(F1) is not a worse 4188 // conversion sequence than ICSi(F2), and then... 4189 unsigned NumArgs = Cand1.Conversions.size(); 4190 assert(Cand2.Conversions.size() == NumArgs && "Overload candidate mismatch"); 4191 bool HasBetterConversion = false; 4192 for (unsigned ArgIdx = StartArg; ArgIdx < NumArgs; ++ArgIdx) { 4193 switch (CompareImplicitConversionSequences(Cand1.Conversions[ArgIdx], 4194 Cand2.Conversions[ArgIdx])) { 4195 case ImplicitConversionSequence::Better: 4196 // Cand1 has a better conversion sequence. 4197 HasBetterConversion = true; 4198 break; 4199 4200 case ImplicitConversionSequence::Worse: 4201 // Cand1 can't be better than Cand2. 4202 return false; 4203 4204 case ImplicitConversionSequence::Indistinguishable: 4205 // Do nothing. 4206 break; 4207 } 4208 } 4209 4210 // -- for some argument j, ICSj(F1) is a better conversion sequence than 4211 // ICSj(F2), or, if not that, 4212 if (HasBetterConversion) 4213 return true; 4214 4215 // - F1 is a non-template function and F2 is a function template 4216 // specialization, or, if not that, 4217 if (Cand1.Function && !Cand1.Function->getPrimaryTemplate() && 4218 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 4219 return true; 4220 4221 // -- F1 and F2 are function template specializations, and the function 4222 // template for F1 is more specialized than the template for F2 4223 // according to the partial ordering rules described in 14.5.5.2, or, 4224 // if not that, 4225 if (Cand1.Function && Cand1.Function->getPrimaryTemplate() && 4226 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 4227 if (FunctionTemplateDecl *BetterTemplate 4228 = getMoreSpecializedTemplate(Cand1.Function->getPrimaryTemplate(), 4229 Cand2.Function->getPrimaryTemplate(), 4230 isa<CXXConversionDecl>(Cand1.Function)? TPOC_Conversion 4231 : TPOC_Call)) 4232 return BetterTemplate == Cand1.Function->getPrimaryTemplate(); 4233 4234 // -- the context is an initialization by user-defined conversion 4235 // (see 8.5, 13.3.1.5) and the standard conversion sequence 4236 // from the return type of F1 to the destination type (i.e., 4237 // the type of the entity being initialized) is a better 4238 // conversion sequence than the standard conversion sequence 4239 // from the return type of F2 to the destination type. 4240 if (Cand1.Function && Cand2.Function && 4241 isa<CXXConversionDecl>(Cand1.Function) && 4242 isa<CXXConversionDecl>(Cand2.Function)) { 4243 switch (CompareStandardConversionSequences(Cand1.FinalConversion, 4244 Cand2.FinalConversion)) { 4245 case ImplicitConversionSequence::Better: 4246 // Cand1 has a better conversion sequence. 4247 return true; 4248 4249 case ImplicitConversionSequence::Worse: 4250 // Cand1 can't be better than Cand2. 4251 return false; 4252 4253 case ImplicitConversionSequence::Indistinguishable: 4254 // Do nothing 4255 break; 4256 } 4257 } 4258 4259 return false; 4260} 4261 4262/// \brief Computes the best viable function (C++ 13.3.3) 4263/// within an overload candidate set. 4264/// 4265/// \param CandidateSet the set of candidate functions. 4266/// 4267/// \param Loc the location of the function name (or operator symbol) for 4268/// which overload resolution occurs. 4269/// 4270/// \param Best f overload resolution was successful or found a deleted 4271/// function, Best points to the candidate function found. 4272/// 4273/// \returns The result of overload resolution. 4274OverloadingResult Sema::BestViableFunction(OverloadCandidateSet& CandidateSet, 4275 SourceLocation Loc, 4276 OverloadCandidateSet::iterator& Best) { 4277 // Find the best viable function. 4278 Best = CandidateSet.end(); 4279 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 4280 Cand != CandidateSet.end(); ++Cand) { 4281 if (Cand->Viable) { 4282 if (Best == CandidateSet.end() || isBetterOverloadCandidate(*Cand, *Best)) 4283 Best = Cand; 4284 } 4285 } 4286 4287 // If we didn't find any viable functions, abort. 4288 if (Best == CandidateSet.end()) 4289 return OR_No_Viable_Function; 4290 4291 // Make sure that this function is better than every other viable 4292 // function. If not, we have an ambiguity. 4293 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 4294 Cand != CandidateSet.end(); ++Cand) { 4295 if (Cand->Viable && 4296 Cand != Best && 4297 !isBetterOverloadCandidate(*Best, *Cand)) { 4298 Best = CandidateSet.end(); 4299 return OR_Ambiguous; 4300 } 4301 } 4302 4303 // Best is the best viable function. 4304 if (Best->Function && 4305 (Best->Function->isDeleted() || 4306 Best->Function->getAttr<UnavailableAttr>())) 4307 return OR_Deleted; 4308 4309 // C++ [basic.def.odr]p2: 4310 // An overloaded function is used if it is selected by overload resolution 4311 // when referred to from a potentially-evaluated expression. [Note: this 4312 // covers calls to named functions (5.2.2), operator overloading 4313 // (clause 13), user-defined conversions (12.3.2), allocation function for 4314 // placement new (5.3.4), as well as non-default initialization (8.5). 4315 if (Best->Function) 4316 MarkDeclarationReferenced(Loc, Best->Function); 4317 return OR_Success; 4318} 4319 4320namespace { 4321 4322enum OverloadCandidateKind { 4323 oc_function, 4324 oc_method, 4325 oc_constructor, 4326 oc_function_template, 4327 oc_method_template, 4328 oc_constructor_template, 4329 oc_implicit_default_constructor, 4330 oc_implicit_copy_constructor, 4331 oc_implicit_copy_assignment 4332}; 4333 4334OverloadCandidateKind ClassifyOverloadCandidate(Sema &S, 4335 FunctionDecl *Fn, 4336 std::string &Description) { 4337 bool isTemplate = false; 4338 4339 if (FunctionTemplateDecl *FunTmpl = Fn->getPrimaryTemplate()) { 4340 isTemplate = true; 4341 Description = S.getTemplateArgumentBindingsText( 4342 FunTmpl->getTemplateParameters(), *Fn->getTemplateSpecializationArgs()); 4343 } 4344 4345 if (CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(Fn)) { 4346 if (!Ctor->isImplicit()) 4347 return isTemplate ? oc_constructor_template : oc_constructor; 4348 4349 return Ctor->isCopyConstructor() ? oc_implicit_copy_constructor 4350 : oc_implicit_default_constructor; 4351 } 4352 4353 if (CXXMethodDecl *Meth = dyn_cast<CXXMethodDecl>(Fn)) { 4354 // This actually gets spelled 'candidate function' for now, but 4355 // it doesn't hurt to split it out. 4356 if (!Meth->isImplicit()) 4357 return isTemplate ? oc_method_template : oc_method; 4358 4359 assert(Meth->isCopyAssignment() 4360 && "implicit method is not copy assignment operator?"); 4361 return oc_implicit_copy_assignment; 4362 } 4363 4364 return isTemplate ? oc_function_template : oc_function; 4365} 4366 4367} // end anonymous namespace 4368 4369// Notes the location of an overload candidate. 4370void Sema::NoteOverloadCandidate(FunctionDecl *Fn) { 4371 std::string FnDesc; 4372 OverloadCandidateKind K = ClassifyOverloadCandidate(*this, Fn, FnDesc); 4373 Diag(Fn->getLocation(), diag::note_ovl_candidate) 4374 << (unsigned) K << FnDesc; 4375} 4376 4377/// Diagnoses an ambiguous conversion. The partial diagnostic is the 4378/// "lead" diagnostic; it will be given two arguments, the source and 4379/// target types of the conversion. 4380void Sema::DiagnoseAmbiguousConversion(const ImplicitConversionSequence &ICS, 4381 SourceLocation CaretLoc, 4382 const PartialDiagnostic &PDiag) { 4383 Diag(CaretLoc, PDiag) 4384 << ICS.Ambiguous.getFromType() << ICS.Ambiguous.getToType(); 4385 for (AmbiguousConversionSequence::const_iterator 4386 I = ICS.Ambiguous.begin(), E = ICS.Ambiguous.end(); I != E; ++I) { 4387 NoteOverloadCandidate(*I); 4388 } 4389} 4390 4391namespace { 4392 4393void DiagnoseBadConversion(Sema &S, OverloadCandidate *Cand, unsigned I) { 4394 const ImplicitConversionSequence &Conv = Cand->Conversions[I]; 4395 assert(Conv.isBad()); 4396 assert(Cand->Function && "for now, candidate must be a function"); 4397 FunctionDecl *Fn = Cand->Function; 4398 4399 // There's a conversion slot for the object argument if this is a 4400 // non-constructor method. Note that 'I' corresponds the 4401 // conversion-slot index. 4402 bool isObjectArgument = false; 4403 if (isa<CXXMethodDecl>(Fn) && !isa<CXXConstructorDecl>(Fn)) { 4404 if (I == 0) 4405 isObjectArgument = true; 4406 else 4407 I--; 4408 } 4409 4410 std::string FnDesc; 4411 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, FnDesc); 4412 4413 Expr *FromExpr = Conv.Bad.FromExpr; 4414 QualType FromTy = Conv.Bad.getFromType(); 4415 QualType ToTy = Conv.Bad.getToType(); 4416 4417 // Do some hand-waving analysis to see if the non-viability is due to a 4418 CanQualType CFromTy = S.Context.getCanonicalType(FromTy); 4419 CanQualType CToTy = S.Context.getCanonicalType(ToTy); 4420 if (CanQual<ReferenceType> RT = CToTy->getAs<ReferenceType>()) 4421 CToTy = RT->getPointeeType(); 4422 else { 4423 // TODO: detect and diagnose the full richness of const mismatches. 4424 if (CanQual<PointerType> FromPT = CFromTy->getAs<PointerType>()) 4425 if (CanQual<PointerType> ToPT = CToTy->getAs<PointerType>()) 4426 CFromTy = FromPT->getPointeeType(), CToTy = ToPT->getPointeeType(); 4427 } 4428 4429 if (CToTy.getUnqualifiedType() == CFromTy.getUnqualifiedType() && 4430 !CToTy.isAtLeastAsQualifiedAs(CFromTy)) { 4431 // It is dumb that we have to do this here. 4432 while (isa<ArrayType>(CFromTy)) 4433 CFromTy = CFromTy->getAs<ArrayType>()->getElementType(); 4434 while (isa<ArrayType>(CToTy)) 4435 CToTy = CFromTy->getAs<ArrayType>()->getElementType(); 4436 4437 Qualifiers FromQs = CFromTy.getQualifiers(); 4438 Qualifiers ToQs = CToTy.getQualifiers(); 4439 4440 if (FromQs.getAddressSpace() != ToQs.getAddressSpace()) { 4441 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_addrspace) 4442 << (unsigned) FnKind << FnDesc 4443 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 4444 << FromTy 4445 << FromQs.getAddressSpace() << ToQs.getAddressSpace() 4446 << (unsigned) isObjectArgument << I+1; 4447 return; 4448 } 4449 4450 unsigned CVR = FromQs.getCVRQualifiers() & ~ToQs.getCVRQualifiers(); 4451 assert(CVR && "unexpected qualifiers mismatch"); 4452 4453 if (isObjectArgument) { 4454 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr_this) 4455 << (unsigned) FnKind << FnDesc 4456 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 4457 << FromTy << (CVR - 1); 4458 } else { 4459 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr) 4460 << (unsigned) FnKind << FnDesc 4461 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 4462 << FromTy << (CVR - 1) << I+1; 4463 } 4464 return; 4465 } 4466 4467 // TODO: specialize more based on the kind of mismatch 4468 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_conv) 4469 << (unsigned) FnKind << FnDesc 4470 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 4471 << FromTy << ToTy << (unsigned) isObjectArgument << I+1; 4472} 4473 4474void DiagnoseArityMismatch(Sema &S, OverloadCandidate *Cand, 4475 unsigned NumFormalArgs) { 4476 // TODO: treat calls to a missing default constructor as a special case 4477 4478 FunctionDecl *Fn = Cand->Function; 4479 const FunctionProtoType *FnTy = Fn->getType()->getAs<FunctionProtoType>(); 4480 4481 unsigned MinParams = Fn->getMinRequiredArguments(); 4482 4483 // at least / at most / exactly 4484 unsigned mode, modeCount; 4485 if (NumFormalArgs < MinParams) { 4486 assert(Cand->FailureKind == ovl_fail_too_few_arguments); 4487 if (MinParams != FnTy->getNumArgs() || FnTy->isVariadic()) 4488 mode = 0; // "at least" 4489 else 4490 mode = 2; // "exactly" 4491 modeCount = MinParams; 4492 } else { 4493 assert(Cand->FailureKind == ovl_fail_too_many_arguments); 4494 if (MinParams != FnTy->getNumArgs()) 4495 mode = 1; // "at most" 4496 else 4497 mode = 2; // "exactly" 4498 modeCount = FnTy->getNumArgs(); 4499 } 4500 4501 std::string Description; 4502 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, Description); 4503 4504 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_arity) 4505 << (unsigned) FnKind << Description << mode << modeCount << NumFormalArgs; 4506} 4507 4508void NoteFunctionCandidate(Sema &S, OverloadCandidate *Cand, 4509 Expr **Args, unsigned NumArgs) { 4510 FunctionDecl *Fn = Cand->Function; 4511 4512 // Note deleted candidates, but only if they're viable. 4513 if (Cand->Viable && (Fn->isDeleted() || Fn->hasAttr<UnavailableAttr>())) { 4514 std::string FnDesc; 4515 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, FnDesc); 4516 4517 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_deleted) 4518 << FnKind << FnDesc << Fn->isDeleted(); 4519 return; 4520 } 4521 4522 // We don't really have anything else to say about viable candidates. 4523 if (Cand->Viable) { 4524 S.NoteOverloadCandidate(Fn); 4525 return; 4526 } 4527 4528 switch (Cand->FailureKind) { 4529 case ovl_fail_too_many_arguments: 4530 case ovl_fail_too_few_arguments: 4531 return DiagnoseArityMismatch(S, Cand, NumArgs); 4532 4533 case ovl_fail_bad_deduction: 4534 case ovl_fail_trivial_conversion: 4535 case ovl_fail_bad_final_conversion: 4536 return S.NoteOverloadCandidate(Fn); 4537 4538 case ovl_fail_bad_conversion: 4539 for (unsigned I = 0, N = Cand->Conversions.size(); I != N; ++I) 4540 if (Cand->Conversions[I].isBad()) 4541 return DiagnoseBadConversion(S, Cand, I); 4542 4543 // FIXME: this currently happens when we're called from SemaInit 4544 // when user-conversion overload fails. Figure out how to handle 4545 // those conditions and diagnose them well. 4546 return S.NoteOverloadCandidate(Fn); 4547 } 4548} 4549 4550void NoteSurrogateCandidate(Sema &S, OverloadCandidate *Cand) { 4551 // Desugar the type of the surrogate down to a function type, 4552 // retaining as many typedefs as possible while still showing 4553 // the function type (and, therefore, its parameter types). 4554 QualType FnType = Cand->Surrogate->getConversionType(); 4555 bool isLValueReference = false; 4556 bool isRValueReference = false; 4557 bool isPointer = false; 4558 if (const LValueReferenceType *FnTypeRef = 4559 FnType->getAs<LValueReferenceType>()) { 4560 FnType = FnTypeRef->getPointeeType(); 4561 isLValueReference = true; 4562 } else if (const RValueReferenceType *FnTypeRef = 4563 FnType->getAs<RValueReferenceType>()) { 4564 FnType = FnTypeRef->getPointeeType(); 4565 isRValueReference = true; 4566 } 4567 if (const PointerType *FnTypePtr = FnType->getAs<PointerType>()) { 4568 FnType = FnTypePtr->getPointeeType(); 4569 isPointer = true; 4570 } 4571 // Desugar down to a function type. 4572 FnType = QualType(FnType->getAs<FunctionType>(), 0); 4573 // Reconstruct the pointer/reference as appropriate. 4574 if (isPointer) FnType = S.Context.getPointerType(FnType); 4575 if (isRValueReference) FnType = S.Context.getRValueReferenceType(FnType); 4576 if (isLValueReference) FnType = S.Context.getLValueReferenceType(FnType); 4577 4578 S.Diag(Cand->Surrogate->getLocation(), diag::note_ovl_surrogate_cand) 4579 << FnType; 4580} 4581 4582void NoteBuiltinOperatorCandidate(Sema &S, 4583 const char *Opc, 4584 SourceLocation OpLoc, 4585 OverloadCandidate *Cand) { 4586 assert(Cand->Conversions.size() <= 2 && "builtin operator is not binary"); 4587 std::string TypeStr("operator"); 4588 TypeStr += Opc; 4589 TypeStr += "("; 4590 TypeStr += Cand->BuiltinTypes.ParamTypes[0].getAsString(); 4591 if (Cand->Conversions.size() == 1) { 4592 TypeStr += ")"; 4593 S.Diag(OpLoc, diag::note_ovl_builtin_unary_candidate) << TypeStr; 4594 } else { 4595 TypeStr += ", "; 4596 TypeStr += Cand->BuiltinTypes.ParamTypes[1].getAsString(); 4597 TypeStr += ")"; 4598 S.Diag(OpLoc, diag::note_ovl_builtin_binary_candidate) << TypeStr; 4599 } 4600} 4601 4602void NoteAmbiguousUserConversions(Sema &S, SourceLocation OpLoc, 4603 OverloadCandidate *Cand) { 4604 unsigned NoOperands = Cand->Conversions.size(); 4605 for (unsigned ArgIdx = 0; ArgIdx < NoOperands; ++ArgIdx) { 4606 const ImplicitConversionSequence &ICS = Cand->Conversions[ArgIdx]; 4607 if (ICS.isBad()) break; // all meaningless after first invalid 4608 if (!ICS.isAmbiguous()) continue; 4609 4610 S.DiagnoseAmbiguousConversion(ICS, OpLoc, 4611 PDiag(diag::note_ambiguous_type_conversion)); 4612 } 4613} 4614 4615SourceLocation GetLocationForCandidate(const OverloadCandidate *Cand) { 4616 if (Cand->Function) 4617 return Cand->Function->getLocation(); 4618 if (Cand->IsSurrogate) 4619 return Cand->Surrogate->getLocation(); 4620 return SourceLocation(); 4621} 4622 4623struct CompareOverloadCandidatesForDisplay { 4624 Sema &S; 4625 CompareOverloadCandidatesForDisplay(Sema &S) : S(S) {} 4626 4627 bool operator()(const OverloadCandidate *L, 4628 const OverloadCandidate *R) { 4629 // Fast-path this check. 4630 if (L == R) return false; 4631 4632 // Order first by viability. 4633 if (L->Viable) { 4634 if (!R->Viable) return true; 4635 4636 // TODO: introduce a tri-valued comparison for overload 4637 // candidates. Would be more worthwhile if we had a sort 4638 // that could exploit it. 4639 if (S.isBetterOverloadCandidate(*L, *R)) return true; 4640 if (S.isBetterOverloadCandidate(*R, *L)) return false; 4641 } else if (R->Viable) 4642 return false; 4643 4644 assert(L->Viable == R->Viable); 4645 4646 // Criteria by which we can sort non-viable candidates: 4647 if (!L->Viable) { 4648 // 1. Arity mismatches come after other candidates. 4649 if (L->FailureKind == ovl_fail_too_many_arguments || 4650 L->FailureKind == ovl_fail_too_few_arguments) 4651 return false; 4652 if (R->FailureKind == ovl_fail_too_many_arguments || 4653 R->FailureKind == ovl_fail_too_few_arguments) 4654 return true; 4655 4656 // 2. Bad conversions come first and are ordered by the number 4657 // of bad conversions and quality of good conversions. 4658 if (L->FailureKind == ovl_fail_bad_conversion) { 4659 if (R->FailureKind != ovl_fail_bad_conversion) 4660 return true; 4661 4662 // If there's any ordering between the defined conversions... 4663 // FIXME: this might not be transitive. 4664 assert(L->Conversions.size() == R->Conversions.size()); 4665 4666 int leftBetter = 0; 4667 for (unsigned I = 0, E = L->Conversions.size(); I != E; ++I) { 4668 switch (S.CompareImplicitConversionSequences(L->Conversions[I], 4669 R->Conversions[I])) { 4670 case ImplicitConversionSequence::Better: 4671 leftBetter++; 4672 break; 4673 4674 case ImplicitConversionSequence::Worse: 4675 leftBetter--; 4676 break; 4677 4678 case ImplicitConversionSequence::Indistinguishable: 4679 break; 4680 } 4681 } 4682 if (leftBetter > 0) return true; 4683 if (leftBetter < 0) return false; 4684 4685 } else if (R->FailureKind == ovl_fail_bad_conversion) 4686 return false; 4687 4688 // TODO: others? 4689 } 4690 4691 // Sort everything else by location. 4692 SourceLocation LLoc = GetLocationForCandidate(L); 4693 SourceLocation RLoc = GetLocationForCandidate(R); 4694 4695 // Put candidates without locations (e.g. builtins) at the end. 4696 if (LLoc.isInvalid()) return false; 4697 if (RLoc.isInvalid()) return true; 4698 4699 return S.SourceMgr.isBeforeInTranslationUnit(LLoc, RLoc); 4700 } 4701}; 4702 4703/// CompleteNonViableCandidate - Normally, overload resolution only 4704/// computes up to the first 4705void CompleteNonViableCandidate(Sema &S, OverloadCandidate *Cand, 4706 Expr **Args, unsigned NumArgs) { 4707 assert(!Cand->Viable); 4708 4709 // Don't do anything on failures other than bad conversion. 4710 if (Cand->FailureKind != ovl_fail_bad_conversion) return; 4711 4712 // Skip forward to the first bad conversion. 4713 unsigned ConvIdx = 0; 4714 unsigned ConvCount = Cand->Conversions.size(); 4715 while (true) { 4716 assert(ConvIdx != ConvCount && "no bad conversion in candidate"); 4717 ConvIdx++; 4718 if (Cand->Conversions[ConvIdx - 1].isBad()) 4719 break; 4720 } 4721 4722 if (ConvIdx == ConvCount) 4723 return; 4724 4725 // FIXME: these should probably be preserved from the overload 4726 // operation somehow. 4727 bool SuppressUserConversions = false; 4728 bool ForceRValue = false; 4729 4730 const FunctionProtoType* Proto; 4731 unsigned ArgIdx = ConvIdx; 4732 4733 if (Cand->IsSurrogate) { 4734 QualType ConvType 4735 = Cand->Surrogate->getConversionType().getNonReferenceType(); 4736 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 4737 ConvType = ConvPtrType->getPointeeType(); 4738 Proto = ConvType->getAs<FunctionProtoType>(); 4739 ArgIdx--; 4740 } else if (Cand->Function) { 4741 Proto = Cand->Function->getType()->getAs<FunctionProtoType>(); 4742 if (isa<CXXMethodDecl>(Cand->Function) && 4743 !isa<CXXConstructorDecl>(Cand->Function)) 4744 ArgIdx--; 4745 } else { 4746 // Builtin binary operator with a bad first conversion. 4747 assert(ConvCount <= 3); 4748 for (; ConvIdx != ConvCount; ++ConvIdx) 4749 Cand->Conversions[ConvIdx] 4750 = S.TryCopyInitialization(Args[ConvIdx], 4751 Cand->BuiltinTypes.ParamTypes[ConvIdx], 4752 SuppressUserConversions, ForceRValue, 4753 /*InOverloadResolution*/ true); 4754 return; 4755 } 4756 4757 // Fill in the rest of the conversions. 4758 unsigned NumArgsInProto = Proto->getNumArgs(); 4759 for (; ConvIdx != ConvCount; ++ConvIdx, ++ArgIdx) { 4760 if (ArgIdx < NumArgsInProto) 4761 Cand->Conversions[ConvIdx] 4762 = S.TryCopyInitialization(Args[ArgIdx], Proto->getArgType(ArgIdx), 4763 SuppressUserConversions, ForceRValue, 4764 /*InOverloadResolution=*/true); 4765 else 4766 Cand->Conversions[ConvIdx].setEllipsis(); 4767 } 4768} 4769 4770} // end anonymous namespace 4771 4772/// PrintOverloadCandidates - When overload resolution fails, prints 4773/// diagnostic messages containing the candidates in the candidate 4774/// set. 4775void 4776Sema::PrintOverloadCandidates(OverloadCandidateSet& CandidateSet, 4777 OverloadCandidateDisplayKind OCD, 4778 Expr **Args, unsigned NumArgs, 4779 const char *Opc, 4780 SourceLocation OpLoc) { 4781 // Sort the candidates by viability and position. Sorting directly would 4782 // be prohibitive, so we make a set of pointers and sort those. 4783 llvm::SmallVector<OverloadCandidate*, 32> Cands; 4784 if (OCD == OCD_AllCandidates) Cands.reserve(CandidateSet.size()); 4785 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 4786 LastCand = CandidateSet.end(); 4787 Cand != LastCand; ++Cand) { 4788 if (Cand->Viable) 4789 Cands.push_back(Cand); 4790 else if (OCD == OCD_AllCandidates) { 4791 CompleteNonViableCandidate(*this, Cand, Args, NumArgs); 4792 Cands.push_back(Cand); 4793 } 4794 } 4795 4796 std::sort(Cands.begin(), Cands.end(), 4797 CompareOverloadCandidatesForDisplay(*this)); 4798 4799 bool ReportedAmbiguousConversions = false; 4800 4801 llvm::SmallVectorImpl<OverloadCandidate*>::iterator I, E; 4802 for (I = Cands.begin(), E = Cands.end(); I != E; ++I) { 4803 OverloadCandidate *Cand = *I; 4804 4805 if (Cand->Function) 4806 NoteFunctionCandidate(*this, Cand, Args, NumArgs); 4807 else if (Cand->IsSurrogate) 4808 NoteSurrogateCandidate(*this, Cand); 4809 4810 // This a builtin candidate. We do not, in general, want to list 4811 // every possible builtin candidate. 4812 else if (Cand->Viable) { 4813 // Generally we only see ambiguities including viable builtin 4814 // operators if overload resolution got screwed up by an 4815 // ambiguous user-defined conversion. 4816 // 4817 // FIXME: It's quite possible for different conversions to see 4818 // different ambiguities, though. 4819 if (!ReportedAmbiguousConversions) { 4820 NoteAmbiguousUserConversions(*this, OpLoc, Cand); 4821 ReportedAmbiguousConversions = true; 4822 } 4823 4824 // If this is a viable builtin, print it. 4825 NoteBuiltinOperatorCandidate(*this, Opc, OpLoc, Cand); 4826 } 4827 } 4828} 4829 4830/// ResolveAddressOfOverloadedFunction - Try to resolve the address of 4831/// an overloaded function (C++ [over.over]), where @p From is an 4832/// expression with overloaded function type and @p ToType is the type 4833/// we're trying to resolve to. For example: 4834/// 4835/// @code 4836/// int f(double); 4837/// int f(int); 4838/// 4839/// int (*pfd)(double) = f; // selects f(double) 4840/// @endcode 4841/// 4842/// This routine returns the resulting FunctionDecl if it could be 4843/// resolved, and NULL otherwise. When @p Complain is true, this 4844/// routine will emit diagnostics if there is an error. 4845FunctionDecl * 4846Sema::ResolveAddressOfOverloadedFunction(Expr *From, QualType ToType, 4847 bool Complain) { 4848 QualType FunctionType = ToType; 4849 bool IsMember = false; 4850 if (const PointerType *ToTypePtr = ToType->getAs<PointerType>()) 4851 FunctionType = ToTypePtr->getPointeeType(); 4852 else if (const ReferenceType *ToTypeRef = ToType->getAs<ReferenceType>()) 4853 FunctionType = ToTypeRef->getPointeeType(); 4854 else if (const MemberPointerType *MemTypePtr = 4855 ToType->getAs<MemberPointerType>()) { 4856 FunctionType = MemTypePtr->getPointeeType(); 4857 IsMember = true; 4858 } 4859 4860 // We only look at pointers or references to functions. 4861 FunctionType = Context.getCanonicalType(FunctionType).getUnqualifiedType(); 4862 if (!FunctionType->isFunctionType()) 4863 return 0; 4864 4865 // Find the actual overloaded function declaration. 4866 4867 // C++ [over.over]p1: 4868 // [...] [Note: any redundant set of parentheses surrounding the 4869 // overloaded function name is ignored (5.1). ] 4870 Expr *OvlExpr = From->IgnoreParens(); 4871 4872 // C++ [over.over]p1: 4873 // [...] The overloaded function name can be preceded by the & 4874 // operator. 4875 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(OvlExpr)) { 4876 if (UnOp->getOpcode() == UnaryOperator::AddrOf) 4877 OvlExpr = UnOp->getSubExpr()->IgnoreParens(); 4878 } 4879 4880 bool HasExplicitTemplateArgs = false; 4881 TemplateArgumentListInfo ExplicitTemplateArgs; 4882 4883 llvm::SmallVector<NamedDecl*,8> Fns; 4884 4885 // Look into the overloaded expression. 4886 if (UnresolvedLookupExpr *UL 4887 = dyn_cast<UnresolvedLookupExpr>(OvlExpr)) { 4888 Fns.append(UL->decls_begin(), UL->decls_end()); 4889 if (UL->hasExplicitTemplateArgs()) { 4890 HasExplicitTemplateArgs = true; 4891 UL->copyTemplateArgumentsInto(ExplicitTemplateArgs); 4892 } 4893 } else if (UnresolvedMemberExpr *ME 4894 = dyn_cast<UnresolvedMemberExpr>(OvlExpr)) { 4895 Fns.append(ME->decls_begin(), ME->decls_end()); 4896 if (ME->hasExplicitTemplateArgs()) { 4897 HasExplicitTemplateArgs = true; 4898 ME->copyTemplateArgumentsInto(ExplicitTemplateArgs); 4899 } 4900 } 4901 4902 // If we didn't actually find anything, we're done. 4903 if (Fns.empty()) 4904 return 0; 4905 4906 // Look through all of the overloaded functions, searching for one 4907 // whose type matches exactly. 4908 llvm::SmallPtrSet<FunctionDecl *, 4> Matches; 4909 bool FoundNonTemplateFunction = false; 4910 for (llvm::SmallVectorImpl<NamedDecl*>::iterator I = Fns.begin(), 4911 E = Fns.end(); I != E; ++I) { 4912 // Look through any using declarations to find the underlying function. 4913 NamedDecl *Fn = (*I)->getUnderlyingDecl(); 4914 4915 // C++ [over.over]p3: 4916 // Non-member functions and static member functions match 4917 // targets of type "pointer-to-function" or "reference-to-function." 4918 // Nonstatic member functions match targets of 4919 // type "pointer-to-member-function." 4920 // Note that according to DR 247, the containing class does not matter. 4921 4922 if (FunctionTemplateDecl *FunctionTemplate 4923 = dyn_cast<FunctionTemplateDecl>(Fn)) { 4924 if (CXXMethodDecl *Method 4925 = dyn_cast<CXXMethodDecl>(FunctionTemplate->getTemplatedDecl())) { 4926 // Skip non-static function templates when converting to pointer, and 4927 // static when converting to member pointer. 4928 if (Method->isStatic() == IsMember) 4929 continue; 4930 } else if (IsMember) 4931 continue; 4932 4933 // C++ [over.over]p2: 4934 // If the name is a function template, template argument deduction is 4935 // done (14.8.2.2), and if the argument deduction succeeds, the 4936 // resulting template argument list is used to generate a single 4937 // function template specialization, which is added to the set of 4938 // overloaded functions considered. 4939 // FIXME: We don't really want to build the specialization here, do we? 4940 FunctionDecl *Specialization = 0; 4941 TemplateDeductionInfo Info(Context); 4942 if (TemplateDeductionResult Result 4943 = DeduceTemplateArguments(FunctionTemplate, 4944 (HasExplicitTemplateArgs ? &ExplicitTemplateArgs : 0), 4945 FunctionType, Specialization, Info)) { 4946 // FIXME: make a note of the failed deduction for diagnostics. 4947 (void)Result; 4948 } else { 4949 // FIXME: If the match isn't exact, shouldn't we just drop this as 4950 // a candidate? Find a testcase before changing the code. 4951 assert(FunctionType 4952 == Context.getCanonicalType(Specialization->getType())); 4953 Matches.insert( 4954 cast<FunctionDecl>(Specialization->getCanonicalDecl())); 4955 } 4956 4957 continue; 4958 } 4959 4960 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 4961 // Skip non-static functions when converting to pointer, and static 4962 // when converting to member pointer. 4963 if (Method->isStatic() == IsMember) 4964 continue; 4965 4966 // If we have explicit template arguments, skip non-templates. 4967 if (HasExplicitTemplateArgs) 4968 continue; 4969 } else if (IsMember) 4970 continue; 4971 4972 if (FunctionDecl *FunDecl = dyn_cast<FunctionDecl>(Fn)) { 4973 QualType ResultTy; 4974 if (Context.hasSameUnqualifiedType(FunctionType, FunDecl->getType()) || 4975 IsNoReturnConversion(Context, FunDecl->getType(), FunctionType, 4976 ResultTy)) { 4977 Matches.insert(cast<FunctionDecl>(FunDecl->getCanonicalDecl())); 4978 FoundNonTemplateFunction = true; 4979 } 4980 } 4981 } 4982 4983 // If there were 0 or 1 matches, we're done. 4984 if (Matches.empty()) 4985 return 0; 4986 else if (Matches.size() == 1) { 4987 FunctionDecl *Result = *Matches.begin(); 4988 MarkDeclarationReferenced(From->getLocStart(), Result); 4989 return Result; 4990 } 4991 4992 // C++ [over.over]p4: 4993 // If more than one function is selected, [...] 4994 typedef llvm::SmallPtrSet<FunctionDecl *, 4>::iterator MatchIter; 4995 if (!FoundNonTemplateFunction) { 4996 // [...] and any given function template specialization F1 is 4997 // eliminated if the set contains a second function template 4998 // specialization whose function template is more specialized 4999 // than the function template of F1 according to the partial 5000 // ordering rules of 14.5.5.2. 5001 5002 // The algorithm specified above is quadratic. We instead use a 5003 // two-pass algorithm (similar to the one used to identify the 5004 // best viable function in an overload set) that identifies the 5005 // best function template (if it exists). 5006 llvm::SmallVector<FunctionDecl *, 8> TemplateMatches(Matches.begin(), 5007 Matches.end()); 5008 FunctionDecl *Result = 5009 getMostSpecialized(TemplateMatches.data(), TemplateMatches.size(), 5010 TPOC_Other, From->getLocStart(), 5011 PDiag(), 5012 PDiag(diag::err_addr_ovl_ambiguous) 5013 << TemplateMatches[0]->getDeclName(), 5014 PDiag(diag::note_ovl_candidate) 5015 << (unsigned) oc_function_template); 5016 MarkDeclarationReferenced(From->getLocStart(), Result); 5017 return Result; 5018 } 5019 5020 // [...] any function template specializations in the set are 5021 // eliminated if the set also contains a non-template function, [...] 5022 llvm::SmallVector<FunctionDecl *, 4> RemainingMatches; 5023 for (MatchIter M = Matches.begin(), MEnd = Matches.end(); M != MEnd; ++M) 5024 if ((*M)->getPrimaryTemplate() == 0) 5025 RemainingMatches.push_back(*M); 5026 5027 // [...] After such eliminations, if any, there shall remain exactly one 5028 // selected function. 5029 if (RemainingMatches.size() == 1) { 5030 FunctionDecl *Result = RemainingMatches.front(); 5031 MarkDeclarationReferenced(From->getLocStart(), Result); 5032 return Result; 5033 } 5034 5035 // FIXME: We should probably return the same thing that BestViableFunction 5036 // returns (even if we issue the diagnostics here). 5037 Diag(From->getLocStart(), diag::err_addr_ovl_ambiguous) 5038 << RemainingMatches[0]->getDeclName(); 5039 for (unsigned I = 0, N = RemainingMatches.size(); I != N; ++I) 5040 NoteOverloadCandidate(RemainingMatches[I]); 5041 return 0; 5042} 5043 5044/// \brief Given an expression that refers to an overloaded function, try to 5045/// resolve that overloaded function expression down to a single function. 5046/// 5047/// This routine can only resolve template-ids that refer to a single function 5048/// template, where that template-id refers to a single template whose template 5049/// arguments are either provided by the template-id or have defaults, 5050/// as described in C++0x [temp.arg.explicit]p3. 5051FunctionDecl *Sema::ResolveSingleFunctionTemplateSpecialization(Expr *From) { 5052 // C++ [over.over]p1: 5053 // [...] [Note: any redundant set of parentheses surrounding the 5054 // overloaded function name is ignored (5.1). ] 5055 Expr *OvlExpr = From->IgnoreParens(); 5056 5057 // C++ [over.over]p1: 5058 // [...] The overloaded function name can be preceded by the & 5059 // operator. 5060 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(OvlExpr)) { 5061 if (UnOp->getOpcode() == UnaryOperator::AddrOf) 5062 OvlExpr = UnOp->getSubExpr()->IgnoreParens(); 5063 } 5064 5065 bool HasExplicitTemplateArgs = false; 5066 TemplateArgumentListInfo ExplicitTemplateArgs; 5067 5068 llvm::SmallVector<NamedDecl*,8> Fns; 5069 5070 // Look into the overloaded expression. 5071 if (UnresolvedLookupExpr *UL 5072 = dyn_cast<UnresolvedLookupExpr>(OvlExpr)) { 5073 Fns.append(UL->decls_begin(), UL->decls_end()); 5074 if (UL->hasExplicitTemplateArgs()) { 5075 HasExplicitTemplateArgs = true; 5076 UL->copyTemplateArgumentsInto(ExplicitTemplateArgs); 5077 } 5078 } else if (UnresolvedMemberExpr *ME 5079 = dyn_cast<UnresolvedMemberExpr>(OvlExpr)) { 5080 Fns.append(ME->decls_begin(), ME->decls_end()); 5081 if (ME->hasExplicitTemplateArgs()) { 5082 HasExplicitTemplateArgs = true; 5083 ME->copyTemplateArgumentsInto(ExplicitTemplateArgs); 5084 } 5085 } 5086 5087 // If we didn't actually find any template-ids, we're done. 5088 if (Fns.empty() || !HasExplicitTemplateArgs) 5089 return 0; 5090 5091 // Look through all of the overloaded functions, searching for one 5092 // whose type matches exactly. 5093 FunctionDecl *Matched = 0; 5094 for (llvm::SmallVectorImpl<NamedDecl*>::iterator I = Fns.begin(), 5095 E = Fns.end(); I != E; ++I) { 5096 // C++0x [temp.arg.explicit]p3: 5097 // [...] In contexts where deduction is done and fails, or in contexts 5098 // where deduction is not done, if a template argument list is 5099 // specified and it, along with any default template arguments, 5100 // identifies a single function template specialization, then the 5101 // template-id is an lvalue for the function template specialization. 5102 FunctionTemplateDecl *FunctionTemplate = cast<FunctionTemplateDecl>(*I); 5103 5104 // C++ [over.over]p2: 5105 // If the name is a function template, template argument deduction is 5106 // done (14.8.2.2), and if the argument deduction succeeds, the 5107 // resulting template argument list is used to generate a single 5108 // function template specialization, which is added to the set of 5109 // overloaded functions considered. 5110 FunctionDecl *Specialization = 0; 5111 TemplateDeductionInfo Info(Context); 5112 if (TemplateDeductionResult Result 5113 = DeduceTemplateArguments(FunctionTemplate, &ExplicitTemplateArgs, 5114 Specialization, Info)) { 5115 // FIXME: make a note of the failed deduction for diagnostics. 5116 (void)Result; 5117 continue; 5118 } 5119 5120 // Multiple matches; we can't resolve to a single declaration. 5121 if (Matched) 5122 return 0; 5123 5124 Matched = Specialization; 5125 } 5126 5127 return Matched; 5128} 5129 5130/// \brief Add a single candidate to the overload set. 5131static void AddOverloadedCallCandidate(Sema &S, 5132 NamedDecl *Callee, 5133 const TemplateArgumentListInfo *ExplicitTemplateArgs, 5134 Expr **Args, unsigned NumArgs, 5135 OverloadCandidateSet &CandidateSet, 5136 bool PartialOverloading) { 5137 if (isa<UsingShadowDecl>(Callee)) 5138 Callee = cast<UsingShadowDecl>(Callee)->getTargetDecl(); 5139 5140 if (FunctionDecl *Func = dyn_cast<FunctionDecl>(Callee)) { 5141 assert(!ExplicitTemplateArgs && "Explicit template arguments?"); 5142 S.AddOverloadCandidate(Func, Args, NumArgs, CandidateSet, false, false, 5143 PartialOverloading); 5144 return; 5145 } 5146 5147 if (FunctionTemplateDecl *FuncTemplate 5148 = dyn_cast<FunctionTemplateDecl>(Callee)) { 5149 S.AddTemplateOverloadCandidate(FuncTemplate, ExplicitTemplateArgs, 5150 Args, NumArgs, CandidateSet); 5151 return; 5152 } 5153 5154 assert(false && "unhandled case in overloaded call candidate"); 5155 5156 // do nothing? 5157} 5158 5159/// \brief Add the overload candidates named by callee and/or found by argument 5160/// dependent lookup to the given overload set. 5161void Sema::AddOverloadedCallCandidates(UnresolvedLookupExpr *ULE, 5162 Expr **Args, unsigned NumArgs, 5163 OverloadCandidateSet &CandidateSet, 5164 bool PartialOverloading) { 5165 5166#ifndef NDEBUG 5167 // Verify that ArgumentDependentLookup is consistent with the rules 5168 // in C++0x [basic.lookup.argdep]p3: 5169 // 5170 // Let X be the lookup set produced by unqualified lookup (3.4.1) 5171 // and let Y be the lookup set produced by argument dependent 5172 // lookup (defined as follows). If X contains 5173 // 5174 // -- a declaration of a class member, or 5175 // 5176 // -- a block-scope function declaration that is not a 5177 // using-declaration, or 5178 // 5179 // -- a declaration that is neither a function or a function 5180 // template 5181 // 5182 // then Y is empty. 5183 5184 if (ULE->requiresADL()) { 5185 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(), 5186 E = ULE->decls_end(); I != E; ++I) { 5187 assert(!(*I)->getDeclContext()->isRecord()); 5188 assert(isa<UsingShadowDecl>(*I) || 5189 !(*I)->getDeclContext()->isFunctionOrMethod()); 5190 assert((*I)->getUnderlyingDecl()->isFunctionOrFunctionTemplate()); 5191 } 5192 } 5193#endif 5194 5195 // It would be nice to avoid this copy. 5196 TemplateArgumentListInfo TABuffer; 5197 const TemplateArgumentListInfo *ExplicitTemplateArgs = 0; 5198 if (ULE->hasExplicitTemplateArgs()) { 5199 ULE->copyTemplateArgumentsInto(TABuffer); 5200 ExplicitTemplateArgs = &TABuffer; 5201 } 5202 5203 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(), 5204 E = ULE->decls_end(); I != E; ++I) 5205 AddOverloadedCallCandidate(*this, *I, ExplicitTemplateArgs, 5206 Args, NumArgs, CandidateSet, 5207 PartialOverloading); 5208 5209 if (ULE->requiresADL()) 5210 AddArgumentDependentLookupCandidates(ULE->getName(), Args, NumArgs, 5211 ExplicitTemplateArgs, 5212 CandidateSet, 5213 PartialOverloading); 5214} 5215 5216static Sema::OwningExprResult Destroy(Sema &SemaRef, Expr *Fn, 5217 Expr **Args, unsigned NumArgs) { 5218 Fn->Destroy(SemaRef.Context); 5219 for (unsigned Arg = 0; Arg < NumArgs; ++Arg) 5220 Args[Arg]->Destroy(SemaRef.Context); 5221 return SemaRef.ExprError(); 5222} 5223 5224/// Attempts to recover from a call where no functions were found. 5225/// 5226/// Returns true if new candidates were found. 5227static Sema::OwningExprResult 5228BuildRecoveryCallExpr(Sema &SemaRef, Expr *Fn, 5229 UnresolvedLookupExpr *ULE, 5230 SourceLocation LParenLoc, 5231 Expr **Args, unsigned NumArgs, 5232 SourceLocation *CommaLocs, 5233 SourceLocation RParenLoc) { 5234 5235 CXXScopeSpec SS; 5236 if (ULE->getQualifier()) { 5237 SS.setScopeRep(ULE->getQualifier()); 5238 SS.setRange(ULE->getQualifierRange()); 5239 } 5240 5241 TemplateArgumentListInfo TABuffer; 5242 const TemplateArgumentListInfo *ExplicitTemplateArgs = 0; 5243 if (ULE->hasExplicitTemplateArgs()) { 5244 ULE->copyTemplateArgumentsInto(TABuffer); 5245 ExplicitTemplateArgs = &TABuffer; 5246 } 5247 5248 LookupResult R(SemaRef, ULE->getName(), ULE->getNameLoc(), 5249 Sema::LookupOrdinaryName); 5250 if (SemaRef.DiagnoseEmptyLookup(/*Scope=*/0, SS, R)) 5251 return Destroy(SemaRef, Fn, Args, NumArgs); 5252 5253 assert(!R.empty() && "lookup results empty despite recovery"); 5254 5255 // Build an implicit member call if appropriate. Just drop the 5256 // casts and such from the call, we don't really care. 5257 Sema::OwningExprResult NewFn = SemaRef.ExprError(); 5258 if ((*R.begin())->isCXXClassMember()) 5259 NewFn = SemaRef.BuildPossibleImplicitMemberExpr(SS, R, ExplicitTemplateArgs); 5260 else if (ExplicitTemplateArgs) 5261 NewFn = SemaRef.BuildTemplateIdExpr(SS, R, false, *ExplicitTemplateArgs); 5262 else 5263 NewFn = SemaRef.BuildDeclarationNameExpr(SS, R, false); 5264 5265 if (NewFn.isInvalid()) 5266 return Destroy(SemaRef, Fn, Args, NumArgs); 5267 5268 Fn->Destroy(SemaRef.Context); 5269 5270 // This shouldn't cause an infinite loop because we're giving it 5271 // an expression with non-empty lookup results, which should never 5272 // end up here. 5273 return SemaRef.ActOnCallExpr(/*Scope*/ 0, move(NewFn), LParenLoc, 5274 Sema::MultiExprArg(SemaRef, (void**) Args, NumArgs), 5275 CommaLocs, RParenLoc); 5276} 5277 5278/// ResolveOverloadedCallFn - Given the call expression that calls Fn 5279/// (which eventually refers to the declaration Func) and the call 5280/// arguments Args/NumArgs, attempt to resolve the function call down 5281/// to a specific function. If overload resolution succeeds, returns 5282/// the function declaration produced by overload 5283/// resolution. Otherwise, emits diagnostics, deletes all of the 5284/// arguments and Fn, and returns NULL. 5285Sema::OwningExprResult 5286Sema::BuildOverloadedCallExpr(Expr *Fn, UnresolvedLookupExpr *ULE, 5287 SourceLocation LParenLoc, 5288 Expr **Args, unsigned NumArgs, 5289 SourceLocation *CommaLocs, 5290 SourceLocation RParenLoc) { 5291#ifndef NDEBUG 5292 if (ULE->requiresADL()) { 5293 // To do ADL, we must have found an unqualified name. 5294 assert(!ULE->getQualifier() && "qualified name with ADL"); 5295 5296 // We don't perform ADL for implicit declarations of builtins. 5297 // Verify that this was correctly set up. 5298 FunctionDecl *F; 5299 if (ULE->decls_begin() + 1 == ULE->decls_end() && 5300 (F = dyn_cast<FunctionDecl>(*ULE->decls_begin())) && 5301 F->getBuiltinID() && F->isImplicit()) 5302 assert(0 && "performing ADL for builtin"); 5303 5304 // We don't perform ADL in C. 5305 assert(getLangOptions().CPlusPlus && "ADL enabled in C"); 5306 } 5307#endif 5308 5309 OverloadCandidateSet CandidateSet; 5310 5311 // Add the functions denoted by the callee to the set of candidate 5312 // functions, including those from argument-dependent lookup. 5313 AddOverloadedCallCandidates(ULE, Args, NumArgs, CandidateSet); 5314 5315 // If we found nothing, try to recover. 5316 // AddRecoveryCallCandidates diagnoses the error itself, so we just 5317 // bailout out if it fails. 5318 if (CandidateSet.empty()) 5319 return BuildRecoveryCallExpr(*this, Fn, ULE, LParenLoc, Args, NumArgs, 5320 CommaLocs, RParenLoc); 5321 5322 OverloadCandidateSet::iterator Best; 5323 switch (BestViableFunction(CandidateSet, Fn->getLocStart(), Best)) { 5324 case OR_Success: { 5325 FunctionDecl *FDecl = Best->Function; 5326 Fn = FixOverloadedFunctionReference(Fn, FDecl); 5327 return BuildResolvedCallExpr(Fn, FDecl, LParenLoc, Args, NumArgs, RParenLoc); 5328 } 5329 5330 case OR_No_Viable_Function: 5331 Diag(Fn->getSourceRange().getBegin(), 5332 diag::err_ovl_no_viable_function_in_call) 5333 << ULE->getName() << Fn->getSourceRange(); 5334 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 5335 break; 5336 5337 case OR_Ambiguous: 5338 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_ambiguous_call) 5339 << ULE->getName() << Fn->getSourceRange(); 5340 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, NumArgs); 5341 break; 5342 5343 case OR_Deleted: 5344 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_deleted_call) 5345 << Best->Function->isDeleted() 5346 << ULE->getName() 5347 << Fn->getSourceRange(); 5348 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 5349 break; 5350 } 5351 5352 // Overload resolution failed. Destroy all of the subexpressions and 5353 // return NULL. 5354 Fn->Destroy(Context); 5355 for (unsigned Arg = 0; Arg < NumArgs; ++Arg) 5356 Args[Arg]->Destroy(Context); 5357 return ExprError(); 5358} 5359 5360static bool IsOverloaded(const Sema::FunctionSet &Functions) { 5361 return Functions.size() > 1 || 5362 (Functions.size() == 1 && isa<FunctionTemplateDecl>(*Functions.begin())); 5363} 5364 5365/// \brief Create a unary operation that may resolve to an overloaded 5366/// operator. 5367/// 5368/// \param OpLoc The location of the operator itself (e.g., '*'). 5369/// 5370/// \param OpcIn The UnaryOperator::Opcode that describes this 5371/// operator. 5372/// 5373/// \param Functions The set of non-member functions that will be 5374/// considered by overload resolution. The caller needs to build this 5375/// set based on the context using, e.g., 5376/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 5377/// set should not contain any member functions; those will be added 5378/// by CreateOverloadedUnaryOp(). 5379/// 5380/// \param input The input argument. 5381Sema::OwningExprResult Sema::CreateOverloadedUnaryOp(SourceLocation OpLoc, 5382 unsigned OpcIn, 5383 FunctionSet &Functions, 5384 ExprArg input) { 5385 UnaryOperator::Opcode Opc = static_cast<UnaryOperator::Opcode>(OpcIn); 5386 Expr *Input = (Expr *)input.get(); 5387 5388 OverloadedOperatorKind Op = UnaryOperator::getOverloadedOperator(Opc); 5389 assert(Op != OO_None && "Invalid opcode for overloaded unary operator"); 5390 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 5391 5392 Expr *Args[2] = { Input, 0 }; 5393 unsigned NumArgs = 1; 5394 5395 // For post-increment and post-decrement, add the implicit '0' as 5396 // the second argument, so that we know this is a post-increment or 5397 // post-decrement. 5398 if (Opc == UnaryOperator::PostInc || Opc == UnaryOperator::PostDec) { 5399 llvm::APSInt Zero(Context.getTypeSize(Context.IntTy), false); 5400 Args[1] = new (Context) IntegerLiteral(Zero, Context.IntTy, 5401 SourceLocation()); 5402 NumArgs = 2; 5403 } 5404 5405 if (Input->isTypeDependent()) { 5406 UnresolvedLookupExpr *Fn 5407 = UnresolvedLookupExpr::Create(Context, /*Dependent*/ true, 5408 0, SourceRange(), OpName, OpLoc, 5409 /*ADL*/ true, IsOverloaded(Functions)); 5410 for (FunctionSet::iterator Func = Functions.begin(), 5411 FuncEnd = Functions.end(); 5412 Func != FuncEnd; ++Func) 5413 Fn->addDecl(*Func); 5414 5415 input.release(); 5416 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 5417 &Args[0], NumArgs, 5418 Context.DependentTy, 5419 OpLoc)); 5420 } 5421 5422 // Build an empty overload set. 5423 OverloadCandidateSet CandidateSet; 5424 5425 // Add the candidates from the given function set. 5426 AddFunctionCandidates(Functions, &Args[0], NumArgs, CandidateSet, false); 5427 5428 // Add operator candidates that are member functions. 5429 AddMemberOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 5430 5431 // Add builtin operator candidates. 5432 AddBuiltinOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 5433 5434 // Perform overload resolution. 5435 OverloadCandidateSet::iterator Best; 5436 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 5437 case OR_Success: { 5438 // We found a built-in operator or an overloaded operator. 5439 FunctionDecl *FnDecl = Best->Function; 5440 5441 if (FnDecl) { 5442 // We matched an overloaded operator. Build a call to that 5443 // operator. 5444 5445 // Convert the arguments. 5446 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 5447 if (PerformObjectArgumentInitialization(Input, Method)) 5448 return ExprError(); 5449 } else { 5450 // Convert the arguments. 5451 OwningExprResult InputInit 5452 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 5453 FnDecl->getParamDecl(0)), 5454 SourceLocation(), 5455 move(input)); 5456 if (InputInit.isInvalid()) 5457 return ExprError(); 5458 5459 input = move(InputInit); 5460 Input = (Expr *)input.get(); 5461 } 5462 5463 // Determine the result type 5464 QualType ResultTy = FnDecl->getResultType().getNonReferenceType(); 5465 5466 // Build the actual expression node. 5467 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 5468 SourceLocation()); 5469 UsualUnaryConversions(FnExpr); 5470 5471 input.release(); 5472 Args[0] = Input; 5473 ExprOwningPtr<CallExpr> TheCall(this, 5474 new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 5475 Args, NumArgs, ResultTy, OpLoc)); 5476 5477 if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall.get(), 5478 FnDecl)) 5479 return ExprError(); 5480 5481 return MaybeBindToTemporary(TheCall.release()); 5482 } else { 5483 // We matched a built-in operator. Convert the arguments, then 5484 // break out so that we will build the appropriate built-in 5485 // operator node. 5486 if (PerformImplicitConversion(Input, Best->BuiltinTypes.ParamTypes[0], 5487 Best->Conversions[0], AA_Passing)) 5488 return ExprError(); 5489 5490 break; 5491 } 5492 } 5493 5494 case OR_No_Viable_Function: 5495 // No viable function; fall through to handling this as a 5496 // built-in operator, which will produce an error message for us. 5497 break; 5498 5499 case OR_Ambiguous: 5500 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 5501 << UnaryOperator::getOpcodeStr(Opc) 5502 << Input->getSourceRange(); 5503 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, NumArgs, 5504 UnaryOperator::getOpcodeStr(Opc), OpLoc); 5505 return ExprError(); 5506 5507 case OR_Deleted: 5508 Diag(OpLoc, diag::err_ovl_deleted_oper) 5509 << Best->Function->isDeleted() 5510 << UnaryOperator::getOpcodeStr(Opc) 5511 << Input->getSourceRange(); 5512 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 5513 return ExprError(); 5514 } 5515 5516 // Either we found no viable overloaded operator or we matched a 5517 // built-in operator. In either case, fall through to trying to 5518 // build a built-in operation. 5519 input.release(); 5520 return CreateBuiltinUnaryOp(OpLoc, Opc, Owned(Input)); 5521} 5522 5523/// \brief Create a binary operation that may resolve to an overloaded 5524/// operator. 5525/// 5526/// \param OpLoc The location of the operator itself (e.g., '+'). 5527/// 5528/// \param OpcIn The BinaryOperator::Opcode that describes this 5529/// operator. 5530/// 5531/// \param Functions The set of non-member functions that will be 5532/// considered by overload resolution. The caller needs to build this 5533/// set based on the context using, e.g., 5534/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 5535/// set should not contain any member functions; those will be added 5536/// by CreateOverloadedBinOp(). 5537/// 5538/// \param LHS Left-hand argument. 5539/// \param RHS Right-hand argument. 5540Sema::OwningExprResult 5541Sema::CreateOverloadedBinOp(SourceLocation OpLoc, 5542 unsigned OpcIn, 5543 FunctionSet &Functions, 5544 Expr *LHS, Expr *RHS) { 5545 Expr *Args[2] = { LHS, RHS }; 5546 LHS=RHS=0; //Please use only Args instead of LHS/RHS couple 5547 5548 BinaryOperator::Opcode Opc = static_cast<BinaryOperator::Opcode>(OpcIn); 5549 OverloadedOperatorKind Op = BinaryOperator::getOverloadedOperator(Opc); 5550 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 5551 5552 // If either side is type-dependent, create an appropriate dependent 5553 // expression. 5554 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 5555 if (Functions.empty()) { 5556 // If there are no functions to store, just build a dependent 5557 // BinaryOperator or CompoundAssignment. 5558 if (Opc <= BinaryOperator::Assign || Opc > BinaryOperator::OrAssign) 5559 return Owned(new (Context) BinaryOperator(Args[0], Args[1], Opc, 5560 Context.DependentTy, OpLoc)); 5561 5562 return Owned(new (Context) CompoundAssignOperator(Args[0], Args[1], Opc, 5563 Context.DependentTy, 5564 Context.DependentTy, 5565 Context.DependentTy, 5566 OpLoc)); 5567 } 5568 5569 UnresolvedLookupExpr *Fn 5570 = UnresolvedLookupExpr::Create(Context, /*Dependent*/ true, 5571 0, SourceRange(), OpName, OpLoc, 5572 /* ADL */ true, IsOverloaded(Functions)); 5573 5574 for (FunctionSet::iterator Func = Functions.begin(), 5575 FuncEnd = Functions.end(); 5576 Func != FuncEnd; ++Func) 5577 Fn->addDecl(*Func); 5578 5579 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 5580 Args, 2, 5581 Context.DependentTy, 5582 OpLoc)); 5583 } 5584 5585 // If this is the .* operator, which is not overloadable, just 5586 // create a built-in binary operator. 5587 if (Opc == BinaryOperator::PtrMemD) 5588 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 5589 5590 // If this is the assignment operator, we only perform overload resolution 5591 // if the left-hand side is a class or enumeration type. This is actually 5592 // a hack. The standard requires that we do overload resolution between the 5593 // various built-in candidates, but as DR507 points out, this can lead to 5594 // problems. So we do it this way, which pretty much follows what GCC does. 5595 // Note that we go the traditional code path for compound assignment forms. 5596 if (Opc==BinaryOperator::Assign && !Args[0]->getType()->isOverloadableType()) 5597 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 5598 5599 // Build an empty overload set. 5600 OverloadCandidateSet CandidateSet; 5601 5602 // Add the candidates from the given function set. 5603 AddFunctionCandidates(Functions, Args, 2, CandidateSet, false); 5604 5605 // Add operator candidates that are member functions. 5606 AddMemberOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 5607 5608 // Add builtin operator candidates. 5609 AddBuiltinOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 5610 5611 // Perform overload resolution. 5612 OverloadCandidateSet::iterator Best; 5613 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 5614 case OR_Success: { 5615 // We found a built-in operator or an overloaded operator. 5616 FunctionDecl *FnDecl = Best->Function; 5617 5618 if (FnDecl) { 5619 // We matched an overloaded operator. Build a call to that 5620 // operator. 5621 5622 // Convert the arguments. 5623 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 5624 OwningExprResult Arg1 5625 = PerformCopyInitialization( 5626 InitializedEntity::InitializeParameter( 5627 FnDecl->getParamDecl(0)), 5628 SourceLocation(), 5629 Owned(Args[1])); 5630 if (Arg1.isInvalid()) 5631 return ExprError(); 5632 5633 if (PerformObjectArgumentInitialization(Args[0], Method)) 5634 return ExprError(); 5635 5636 Args[1] = RHS = Arg1.takeAs<Expr>(); 5637 } else { 5638 // Convert the arguments. 5639 OwningExprResult Arg0 5640 = PerformCopyInitialization( 5641 InitializedEntity::InitializeParameter( 5642 FnDecl->getParamDecl(0)), 5643 SourceLocation(), 5644 Owned(Args[0])); 5645 if (Arg0.isInvalid()) 5646 return ExprError(); 5647 5648 OwningExprResult Arg1 5649 = PerformCopyInitialization( 5650 InitializedEntity::InitializeParameter( 5651 FnDecl->getParamDecl(1)), 5652 SourceLocation(), 5653 Owned(Args[1])); 5654 if (Arg1.isInvalid()) 5655 return ExprError(); 5656 Args[0] = LHS = Arg0.takeAs<Expr>(); 5657 Args[1] = RHS = Arg1.takeAs<Expr>(); 5658 } 5659 5660 // Determine the result type 5661 QualType ResultTy 5662 = FnDecl->getType()->getAs<FunctionType>()->getResultType(); 5663 ResultTy = ResultTy.getNonReferenceType(); 5664 5665 // Build the actual expression node. 5666 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 5667 OpLoc); 5668 UsualUnaryConversions(FnExpr); 5669 5670 ExprOwningPtr<CXXOperatorCallExpr> 5671 TheCall(this, new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 5672 Args, 2, ResultTy, 5673 OpLoc)); 5674 5675 if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall.get(), 5676 FnDecl)) 5677 return ExprError(); 5678 5679 return MaybeBindToTemporary(TheCall.release()); 5680 } else { 5681 // We matched a built-in operator. Convert the arguments, then 5682 // break out so that we will build the appropriate built-in 5683 // operator node. 5684 if (PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 5685 Best->Conversions[0], AA_Passing) || 5686 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 5687 Best->Conversions[1], AA_Passing)) 5688 return ExprError(); 5689 5690 break; 5691 } 5692 } 5693 5694 case OR_No_Viable_Function: { 5695 // C++ [over.match.oper]p9: 5696 // If the operator is the operator , [...] and there are no 5697 // viable functions, then the operator is assumed to be the 5698 // built-in operator and interpreted according to clause 5. 5699 if (Opc == BinaryOperator::Comma) 5700 break; 5701 5702 // For class as left operand for assignment or compound assigment operator 5703 // do not fall through to handling in built-in, but report that no overloaded 5704 // assignment operator found 5705 OwningExprResult Result = ExprError(); 5706 if (Args[0]->getType()->isRecordType() && 5707 Opc >= BinaryOperator::Assign && Opc <= BinaryOperator::OrAssign) { 5708 Diag(OpLoc, diag::err_ovl_no_viable_oper) 5709 << BinaryOperator::getOpcodeStr(Opc) 5710 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 5711 } else { 5712 // No viable function; try to create a built-in operation, which will 5713 // produce an error. Then, show the non-viable candidates. 5714 Result = CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 5715 } 5716 assert(Result.isInvalid() && 5717 "C++ binary operator overloading is missing candidates!"); 5718 if (Result.isInvalid()) 5719 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2, 5720 BinaryOperator::getOpcodeStr(Opc), OpLoc); 5721 return move(Result); 5722 } 5723 5724 case OR_Ambiguous: 5725 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 5726 << BinaryOperator::getOpcodeStr(Opc) 5727 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 5728 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, 2, 5729 BinaryOperator::getOpcodeStr(Opc), OpLoc); 5730 return ExprError(); 5731 5732 case OR_Deleted: 5733 Diag(OpLoc, diag::err_ovl_deleted_oper) 5734 << Best->Function->isDeleted() 5735 << BinaryOperator::getOpcodeStr(Opc) 5736 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 5737 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2); 5738 return ExprError(); 5739 } 5740 5741 // We matched a built-in operator; build it. 5742 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 5743} 5744 5745Action::OwningExprResult 5746Sema::CreateOverloadedArraySubscriptExpr(SourceLocation LLoc, 5747 SourceLocation RLoc, 5748 ExprArg Base, ExprArg Idx) { 5749 Expr *Args[2] = { static_cast<Expr*>(Base.get()), 5750 static_cast<Expr*>(Idx.get()) }; 5751 DeclarationName OpName = 5752 Context.DeclarationNames.getCXXOperatorName(OO_Subscript); 5753 5754 // If either side is type-dependent, create an appropriate dependent 5755 // expression. 5756 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 5757 5758 UnresolvedLookupExpr *Fn 5759 = UnresolvedLookupExpr::Create(Context, /*Dependent*/ true, 5760 0, SourceRange(), OpName, LLoc, 5761 /*ADL*/ true, /*Overloaded*/ false); 5762 // Can't add any actual overloads yet 5763 5764 Base.release(); 5765 Idx.release(); 5766 return Owned(new (Context) CXXOperatorCallExpr(Context, OO_Subscript, Fn, 5767 Args, 2, 5768 Context.DependentTy, 5769 RLoc)); 5770 } 5771 5772 // Build an empty overload set. 5773 OverloadCandidateSet CandidateSet; 5774 5775 // Subscript can only be overloaded as a member function. 5776 5777 // Add operator candidates that are member functions. 5778 AddMemberOperatorCandidates(OO_Subscript, LLoc, Args, 2, CandidateSet); 5779 5780 // Add builtin operator candidates. 5781 AddBuiltinOperatorCandidates(OO_Subscript, LLoc, Args, 2, CandidateSet); 5782 5783 // Perform overload resolution. 5784 OverloadCandidateSet::iterator Best; 5785 switch (BestViableFunction(CandidateSet, LLoc, Best)) { 5786 case OR_Success: { 5787 // We found a built-in operator or an overloaded operator. 5788 FunctionDecl *FnDecl = Best->Function; 5789 5790 if (FnDecl) { 5791 // We matched an overloaded operator. Build a call to that 5792 // operator. 5793 5794 // Convert the arguments. 5795 CXXMethodDecl *Method = cast<CXXMethodDecl>(FnDecl); 5796 if (PerformObjectArgumentInitialization(Args[0], Method) || 5797 PerformCopyInitialization(Args[1], 5798 FnDecl->getParamDecl(0)->getType(), 5799 AA_Passing)) 5800 return ExprError(); 5801 5802 // Determine the result type 5803 QualType ResultTy 5804 = FnDecl->getType()->getAs<FunctionType>()->getResultType(); 5805 ResultTy = ResultTy.getNonReferenceType(); 5806 5807 // Build the actual expression node. 5808 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 5809 LLoc); 5810 UsualUnaryConversions(FnExpr); 5811 5812 Base.release(); 5813 Idx.release(); 5814 ExprOwningPtr<CXXOperatorCallExpr> 5815 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Subscript, 5816 FnExpr, Args, 2, 5817 ResultTy, RLoc)); 5818 5819 if (CheckCallReturnType(FnDecl->getResultType(), LLoc, TheCall.get(), 5820 FnDecl)) 5821 return ExprError(); 5822 5823 return MaybeBindToTemporary(TheCall.release()); 5824 } else { 5825 // We matched a built-in operator. Convert the arguments, then 5826 // break out so that we will build the appropriate built-in 5827 // operator node. 5828 if (PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 5829 Best->Conversions[0], AA_Passing) || 5830 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 5831 Best->Conversions[1], AA_Passing)) 5832 return ExprError(); 5833 5834 break; 5835 } 5836 } 5837 5838 case OR_No_Viable_Function: { 5839 if (CandidateSet.empty()) 5840 Diag(LLoc, diag::err_ovl_no_oper) 5841 << Args[0]->getType() << /*subscript*/ 0 5842 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 5843 else 5844 Diag(LLoc, diag::err_ovl_no_viable_subscript) 5845 << Args[0]->getType() 5846 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 5847 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2, 5848 "[]", LLoc); 5849 return ExprError(); 5850 } 5851 5852 case OR_Ambiguous: 5853 Diag(LLoc, diag::err_ovl_ambiguous_oper) 5854 << "[]" << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 5855 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, 2, 5856 "[]", LLoc); 5857 return ExprError(); 5858 5859 case OR_Deleted: 5860 Diag(LLoc, diag::err_ovl_deleted_oper) 5861 << Best->Function->isDeleted() << "[]" 5862 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 5863 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2, 5864 "[]", LLoc); 5865 return ExprError(); 5866 } 5867 5868 // We matched a built-in operator; build it. 5869 Base.release(); 5870 Idx.release(); 5871 return CreateBuiltinArraySubscriptExpr(Owned(Args[0]), LLoc, 5872 Owned(Args[1]), RLoc); 5873} 5874 5875/// BuildCallToMemberFunction - Build a call to a member 5876/// function. MemExpr is the expression that refers to the member 5877/// function (and includes the object parameter), Args/NumArgs are the 5878/// arguments to the function call (not including the object 5879/// parameter). The caller needs to validate that the member 5880/// expression refers to a member function or an overloaded member 5881/// function. 5882Sema::OwningExprResult 5883Sema::BuildCallToMemberFunction(Scope *S, Expr *MemExprE, 5884 SourceLocation LParenLoc, Expr **Args, 5885 unsigned NumArgs, SourceLocation *CommaLocs, 5886 SourceLocation RParenLoc) { 5887 // Dig out the member expression. This holds both the object 5888 // argument and the member function we're referring to. 5889 Expr *NakedMemExpr = MemExprE->IgnoreParens(); 5890 5891 MemberExpr *MemExpr; 5892 CXXMethodDecl *Method = 0; 5893 if (isa<MemberExpr>(NakedMemExpr)) { 5894 MemExpr = cast<MemberExpr>(NakedMemExpr); 5895 Method = cast<CXXMethodDecl>(MemExpr->getMemberDecl()); 5896 } else { 5897 UnresolvedMemberExpr *UnresExpr = cast<UnresolvedMemberExpr>(NakedMemExpr); 5898 5899 QualType ObjectType = UnresExpr->getBaseType(); 5900 5901 // Add overload candidates 5902 OverloadCandidateSet CandidateSet; 5903 5904 // FIXME: avoid copy. 5905 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 5906 if (UnresExpr->hasExplicitTemplateArgs()) { 5907 UnresExpr->copyTemplateArgumentsInto(TemplateArgsBuffer); 5908 TemplateArgs = &TemplateArgsBuffer; 5909 } 5910 5911 for (UnresolvedMemberExpr::decls_iterator I = UnresExpr->decls_begin(), 5912 E = UnresExpr->decls_end(); I != E; ++I) { 5913 5914 NamedDecl *Func = *I; 5915 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(Func->getDeclContext()); 5916 if (isa<UsingShadowDecl>(Func)) 5917 Func = cast<UsingShadowDecl>(Func)->getTargetDecl(); 5918 5919 if ((Method = dyn_cast<CXXMethodDecl>(Func))) { 5920 // If explicit template arguments were provided, we can't call a 5921 // non-template member function. 5922 if (TemplateArgs) 5923 continue; 5924 5925 AddMethodCandidate(Method, ActingDC, ObjectType, Args, NumArgs, 5926 CandidateSet, /*SuppressUserConversions=*/false); 5927 } else { 5928 AddMethodTemplateCandidate(cast<FunctionTemplateDecl>(Func), 5929 ActingDC, TemplateArgs, 5930 ObjectType, Args, NumArgs, 5931 CandidateSet, 5932 /*SuppressUsedConversions=*/false); 5933 } 5934 } 5935 5936 DeclarationName DeclName = UnresExpr->getMemberName(); 5937 5938 OverloadCandidateSet::iterator Best; 5939 switch (BestViableFunction(CandidateSet, UnresExpr->getLocStart(), Best)) { 5940 case OR_Success: 5941 Method = cast<CXXMethodDecl>(Best->Function); 5942 break; 5943 5944 case OR_No_Viable_Function: 5945 Diag(UnresExpr->getMemberLoc(), 5946 diag::err_ovl_no_viable_member_function_in_call) 5947 << DeclName << MemExprE->getSourceRange(); 5948 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 5949 // FIXME: Leaking incoming expressions! 5950 return ExprError(); 5951 5952 case OR_Ambiguous: 5953 Diag(UnresExpr->getMemberLoc(), diag::err_ovl_ambiguous_member_call) 5954 << DeclName << MemExprE->getSourceRange(); 5955 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 5956 // FIXME: Leaking incoming expressions! 5957 return ExprError(); 5958 5959 case OR_Deleted: 5960 Diag(UnresExpr->getMemberLoc(), diag::err_ovl_deleted_member_call) 5961 << Best->Function->isDeleted() 5962 << DeclName << MemExprE->getSourceRange(); 5963 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 5964 // FIXME: Leaking incoming expressions! 5965 return ExprError(); 5966 } 5967 5968 MemExprE = FixOverloadedFunctionReference(MemExprE, Method); 5969 5970 // If overload resolution picked a static member, build a 5971 // non-member call based on that function. 5972 if (Method->isStatic()) { 5973 return BuildResolvedCallExpr(MemExprE, Method, LParenLoc, 5974 Args, NumArgs, RParenLoc); 5975 } 5976 5977 MemExpr = cast<MemberExpr>(MemExprE->IgnoreParens()); 5978 } 5979 5980 assert(Method && "Member call to something that isn't a method?"); 5981 ExprOwningPtr<CXXMemberCallExpr> 5982 TheCall(this, new (Context) CXXMemberCallExpr(Context, MemExprE, Args, 5983 NumArgs, 5984 Method->getResultType().getNonReferenceType(), 5985 RParenLoc)); 5986 5987 // Check for a valid return type. 5988 if (CheckCallReturnType(Method->getResultType(), MemExpr->getMemberLoc(), 5989 TheCall.get(), Method)) 5990 return ExprError(); 5991 5992 // Convert the object argument (for a non-static member function call). 5993 Expr *ObjectArg = MemExpr->getBase(); 5994 if (!Method->isStatic() && 5995 PerformObjectArgumentInitialization(ObjectArg, Method)) 5996 return ExprError(); 5997 MemExpr->setBase(ObjectArg); 5998 5999 // Convert the rest of the arguments 6000 const FunctionProtoType *Proto = cast<FunctionProtoType>(Method->getType()); 6001 if (ConvertArgumentsForCall(&*TheCall, MemExpr, Method, Proto, Args, NumArgs, 6002 RParenLoc)) 6003 return ExprError(); 6004 6005 if (CheckFunctionCall(Method, TheCall.get())) 6006 return ExprError(); 6007 6008 return MaybeBindToTemporary(TheCall.release()); 6009} 6010 6011/// BuildCallToObjectOfClassType - Build a call to an object of class 6012/// type (C++ [over.call.object]), which can end up invoking an 6013/// overloaded function call operator (@c operator()) or performing a 6014/// user-defined conversion on the object argument. 6015Sema::ExprResult 6016Sema::BuildCallToObjectOfClassType(Scope *S, Expr *Object, 6017 SourceLocation LParenLoc, 6018 Expr **Args, unsigned NumArgs, 6019 SourceLocation *CommaLocs, 6020 SourceLocation RParenLoc) { 6021 assert(Object->getType()->isRecordType() && "Requires object type argument"); 6022 const RecordType *Record = Object->getType()->getAs<RecordType>(); 6023 6024 // C++ [over.call.object]p1: 6025 // If the primary-expression E in the function call syntax 6026 // evaluates to a class object of type "cv T", then the set of 6027 // candidate functions includes at least the function call 6028 // operators of T. The function call operators of T are obtained by 6029 // ordinary lookup of the name operator() in the context of 6030 // (E).operator(). 6031 OverloadCandidateSet CandidateSet; 6032 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Call); 6033 6034 if (RequireCompleteType(LParenLoc, Object->getType(), 6035 PartialDiagnostic(diag::err_incomplete_object_call) 6036 << Object->getSourceRange())) 6037 return true; 6038 6039 LookupResult R(*this, OpName, LParenLoc, LookupOrdinaryName); 6040 LookupQualifiedName(R, Record->getDecl()); 6041 R.suppressDiagnostics(); 6042 6043 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 6044 Oper != OperEnd; ++Oper) { 6045 AddMethodCandidate(*Oper, Object->getType(), Args, NumArgs, CandidateSet, 6046 /*SuppressUserConversions=*/ false); 6047 } 6048 6049 // C++ [over.call.object]p2: 6050 // In addition, for each conversion function declared in T of the 6051 // form 6052 // 6053 // operator conversion-type-id () cv-qualifier; 6054 // 6055 // where cv-qualifier is the same cv-qualification as, or a 6056 // greater cv-qualification than, cv, and where conversion-type-id 6057 // denotes the type "pointer to function of (P1,...,Pn) returning 6058 // R", or the type "reference to pointer to function of 6059 // (P1,...,Pn) returning R", or the type "reference to function 6060 // of (P1,...,Pn) returning R", a surrogate call function [...] 6061 // is also considered as a candidate function. Similarly, 6062 // surrogate call functions are added to the set of candidate 6063 // functions for each conversion function declared in an 6064 // accessible base class provided the function is not hidden 6065 // within T by another intervening declaration. 6066 const UnresolvedSetImpl *Conversions 6067 = cast<CXXRecordDecl>(Record->getDecl())->getVisibleConversionFunctions(); 6068 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 6069 E = Conversions->end(); I != E; ++I) { 6070 NamedDecl *D = *I; 6071 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext()); 6072 if (isa<UsingShadowDecl>(D)) 6073 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 6074 6075 // Skip over templated conversion functions; they aren't 6076 // surrogates. 6077 if (isa<FunctionTemplateDecl>(D)) 6078 continue; 6079 6080 CXXConversionDecl *Conv = cast<CXXConversionDecl>(D); 6081 6082 // Strip the reference type (if any) and then the pointer type (if 6083 // any) to get down to what might be a function type. 6084 QualType ConvType = Conv->getConversionType().getNonReferenceType(); 6085 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 6086 ConvType = ConvPtrType->getPointeeType(); 6087 6088 if (const FunctionProtoType *Proto = ConvType->getAs<FunctionProtoType>()) 6089 AddSurrogateCandidate(Conv, ActingContext, Proto, 6090 Object->getType(), Args, NumArgs, 6091 CandidateSet); 6092 } 6093 6094 // Perform overload resolution. 6095 OverloadCandidateSet::iterator Best; 6096 switch (BestViableFunction(CandidateSet, Object->getLocStart(), Best)) { 6097 case OR_Success: 6098 // Overload resolution succeeded; we'll build the appropriate call 6099 // below. 6100 break; 6101 6102 case OR_No_Viable_Function: 6103 if (CandidateSet.empty()) 6104 Diag(Object->getSourceRange().getBegin(), diag::err_ovl_no_oper) 6105 << Object->getType() << /*call*/ 1 6106 << Object->getSourceRange(); 6107 else 6108 Diag(Object->getSourceRange().getBegin(), 6109 diag::err_ovl_no_viable_object_call) 6110 << Object->getType() << Object->getSourceRange(); 6111 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6112 break; 6113 6114 case OR_Ambiguous: 6115 Diag(Object->getSourceRange().getBegin(), 6116 diag::err_ovl_ambiguous_object_call) 6117 << Object->getType() << Object->getSourceRange(); 6118 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, NumArgs); 6119 break; 6120 6121 case OR_Deleted: 6122 Diag(Object->getSourceRange().getBegin(), 6123 diag::err_ovl_deleted_object_call) 6124 << Best->Function->isDeleted() 6125 << Object->getType() << Object->getSourceRange(); 6126 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6127 break; 6128 } 6129 6130 if (Best == CandidateSet.end()) { 6131 // We had an error; delete all of the subexpressions and return 6132 // the error. 6133 Object->Destroy(Context); 6134 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 6135 Args[ArgIdx]->Destroy(Context); 6136 return true; 6137 } 6138 6139 if (Best->Function == 0) { 6140 // Since there is no function declaration, this is one of the 6141 // surrogate candidates. Dig out the conversion function. 6142 CXXConversionDecl *Conv 6143 = cast<CXXConversionDecl>( 6144 Best->Conversions[0].UserDefined.ConversionFunction); 6145 6146 // We selected one of the surrogate functions that converts the 6147 // object parameter to a function pointer. Perform the conversion 6148 // on the object argument, then let ActOnCallExpr finish the job. 6149 6150 // Create an implicit member expr to refer to the conversion operator. 6151 // and then call it. 6152 CXXMemberCallExpr *CE = BuildCXXMemberCallExpr(Object, Conv); 6153 6154 return ActOnCallExpr(S, ExprArg(*this, CE), LParenLoc, 6155 MultiExprArg(*this, (ExprTy**)Args, NumArgs), 6156 CommaLocs, RParenLoc).release(); 6157 } 6158 6159 // We found an overloaded operator(). Build a CXXOperatorCallExpr 6160 // that calls this method, using Object for the implicit object 6161 // parameter and passing along the remaining arguments. 6162 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 6163 const FunctionProtoType *Proto = Method->getType()->getAs<FunctionProtoType>(); 6164 6165 unsigned NumArgsInProto = Proto->getNumArgs(); 6166 unsigned NumArgsToCheck = NumArgs; 6167 6168 // Build the full argument list for the method call (the 6169 // implicit object parameter is placed at the beginning of the 6170 // list). 6171 Expr **MethodArgs; 6172 if (NumArgs < NumArgsInProto) { 6173 NumArgsToCheck = NumArgsInProto; 6174 MethodArgs = new Expr*[NumArgsInProto + 1]; 6175 } else { 6176 MethodArgs = new Expr*[NumArgs + 1]; 6177 } 6178 MethodArgs[0] = Object; 6179 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 6180 MethodArgs[ArgIdx + 1] = Args[ArgIdx]; 6181 6182 Expr *NewFn = new (Context) DeclRefExpr(Method, Method->getType(), 6183 SourceLocation()); 6184 UsualUnaryConversions(NewFn); 6185 6186 // Once we've built TheCall, all of the expressions are properly 6187 // owned. 6188 QualType ResultTy = Method->getResultType().getNonReferenceType(); 6189 ExprOwningPtr<CXXOperatorCallExpr> 6190 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Call, NewFn, 6191 MethodArgs, NumArgs + 1, 6192 ResultTy, RParenLoc)); 6193 delete [] MethodArgs; 6194 6195 if (CheckCallReturnType(Method->getResultType(), LParenLoc, TheCall.get(), 6196 Method)) 6197 return true; 6198 6199 // We may have default arguments. If so, we need to allocate more 6200 // slots in the call for them. 6201 if (NumArgs < NumArgsInProto) 6202 TheCall->setNumArgs(Context, NumArgsInProto + 1); 6203 else if (NumArgs > NumArgsInProto) 6204 NumArgsToCheck = NumArgsInProto; 6205 6206 bool IsError = false; 6207 6208 // Initialize the implicit object parameter. 6209 IsError |= PerformObjectArgumentInitialization(Object, Method); 6210 TheCall->setArg(0, Object); 6211 6212 6213 // Check the argument types. 6214 for (unsigned i = 0; i != NumArgsToCheck; i++) { 6215 Expr *Arg; 6216 if (i < NumArgs) { 6217 Arg = Args[i]; 6218 6219 // Pass the argument. 6220 QualType ProtoArgType = Proto->getArgType(i); 6221 IsError |= PerformCopyInitialization(Arg, ProtoArgType, AA_Passing); 6222 } else { 6223 OwningExprResult DefArg 6224 = BuildCXXDefaultArgExpr(LParenLoc, Method, Method->getParamDecl(i)); 6225 if (DefArg.isInvalid()) { 6226 IsError = true; 6227 break; 6228 } 6229 6230 Arg = DefArg.takeAs<Expr>(); 6231 } 6232 6233 TheCall->setArg(i + 1, Arg); 6234 } 6235 6236 // If this is a variadic call, handle args passed through "...". 6237 if (Proto->isVariadic()) { 6238 // Promote the arguments (C99 6.5.2.2p7). 6239 for (unsigned i = NumArgsInProto; i != NumArgs; i++) { 6240 Expr *Arg = Args[i]; 6241 IsError |= DefaultVariadicArgumentPromotion(Arg, VariadicMethod); 6242 TheCall->setArg(i + 1, Arg); 6243 } 6244 } 6245 6246 if (IsError) return true; 6247 6248 if (CheckFunctionCall(Method, TheCall.get())) 6249 return true; 6250 6251 return MaybeBindToTemporary(TheCall.release()).release(); 6252} 6253 6254/// BuildOverloadedArrowExpr - Build a call to an overloaded @c operator-> 6255/// (if one exists), where @c Base is an expression of class type and 6256/// @c Member is the name of the member we're trying to find. 6257Sema::OwningExprResult 6258Sema::BuildOverloadedArrowExpr(Scope *S, ExprArg BaseIn, SourceLocation OpLoc) { 6259 Expr *Base = static_cast<Expr *>(BaseIn.get()); 6260 assert(Base->getType()->isRecordType() && "left-hand side must have class type"); 6261 6262 // C++ [over.ref]p1: 6263 // 6264 // [...] An expression x->m is interpreted as (x.operator->())->m 6265 // for a class object x of type T if T::operator->() exists and if 6266 // the operator is selected as the best match function by the 6267 // overload resolution mechanism (13.3). 6268 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Arrow); 6269 OverloadCandidateSet CandidateSet; 6270 const RecordType *BaseRecord = Base->getType()->getAs<RecordType>(); 6271 6272 if (RequireCompleteType(Base->getLocStart(), Base->getType(), 6273 PDiag(diag::err_typecheck_incomplete_tag) 6274 << Base->getSourceRange())) 6275 return ExprError(); 6276 6277 LookupResult R(*this, OpName, OpLoc, LookupOrdinaryName); 6278 LookupQualifiedName(R, BaseRecord->getDecl()); 6279 R.suppressDiagnostics(); 6280 6281 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 6282 Oper != OperEnd; ++Oper) { 6283 NamedDecl *D = *Oper; 6284 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext()); 6285 if (isa<UsingShadowDecl>(D)) 6286 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 6287 6288 AddMethodCandidate(cast<CXXMethodDecl>(D), ActingContext, 6289 Base->getType(), 0, 0, CandidateSet, 6290 /*SuppressUserConversions=*/false); 6291 } 6292 6293 // Perform overload resolution. 6294 OverloadCandidateSet::iterator Best; 6295 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 6296 case OR_Success: 6297 // Overload resolution succeeded; we'll build the call below. 6298 break; 6299 6300 case OR_No_Viable_Function: 6301 if (CandidateSet.empty()) 6302 Diag(OpLoc, diag::err_typecheck_member_reference_arrow) 6303 << Base->getType() << Base->getSourceRange(); 6304 else 6305 Diag(OpLoc, diag::err_ovl_no_viable_oper) 6306 << "operator->" << Base->getSourceRange(); 6307 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, &Base, 1); 6308 return ExprError(); 6309 6310 case OR_Ambiguous: 6311 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 6312 << "->" << Base->getSourceRange(); 6313 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, &Base, 1); 6314 return ExprError(); 6315 6316 case OR_Deleted: 6317 Diag(OpLoc, diag::err_ovl_deleted_oper) 6318 << Best->Function->isDeleted() 6319 << "->" << Base->getSourceRange(); 6320 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, &Base, 1); 6321 return ExprError(); 6322 } 6323 6324 // Convert the object parameter. 6325 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 6326 if (PerformObjectArgumentInitialization(Base, Method)) 6327 return ExprError(); 6328 6329 // No concerns about early exits now. 6330 BaseIn.release(); 6331 6332 // Build the operator call. 6333 Expr *FnExpr = new (Context) DeclRefExpr(Method, Method->getType(), 6334 SourceLocation()); 6335 UsualUnaryConversions(FnExpr); 6336 6337 QualType ResultTy = Method->getResultType().getNonReferenceType(); 6338 ExprOwningPtr<CXXOperatorCallExpr> 6339 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Arrow, FnExpr, 6340 &Base, 1, ResultTy, OpLoc)); 6341 6342 if (CheckCallReturnType(Method->getResultType(), OpLoc, TheCall.get(), 6343 Method)) 6344 return ExprError(); 6345 return move(TheCall); 6346} 6347 6348/// FixOverloadedFunctionReference - E is an expression that refers to 6349/// a C++ overloaded function (possibly with some parentheses and 6350/// perhaps a '&' around it). We have resolved the overloaded function 6351/// to the function declaration Fn, so patch up the expression E to 6352/// refer (possibly indirectly) to Fn. Returns the new expr. 6353Expr *Sema::FixOverloadedFunctionReference(Expr *E, FunctionDecl *Fn) { 6354 if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) { 6355 Expr *SubExpr = FixOverloadedFunctionReference(PE->getSubExpr(), Fn); 6356 if (SubExpr == PE->getSubExpr()) 6357 return PE->Retain(); 6358 6359 return new (Context) ParenExpr(PE->getLParen(), PE->getRParen(), SubExpr); 6360 } 6361 6362 if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) { 6363 Expr *SubExpr = FixOverloadedFunctionReference(ICE->getSubExpr(), Fn); 6364 assert(Context.hasSameType(ICE->getSubExpr()->getType(), 6365 SubExpr->getType()) && 6366 "Implicit cast type cannot be determined from overload"); 6367 if (SubExpr == ICE->getSubExpr()) 6368 return ICE->Retain(); 6369 6370 return new (Context) ImplicitCastExpr(ICE->getType(), 6371 ICE->getCastKind(), 6372 SubExpr, 6373 ICE->isLvalueCast()); 6374 } 6375 6376 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(E)) { 6377 assert(UnOp->getOpcode() == UnaryOperator::AddrOf && 6378 "Can only take the address of an overloaded function"); 6379 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 6380 if (Method->isStatic()) { 6381 // Do nothing: static member functions aren't any different 6382 // from non-member functions. 6383 } else { 6384 // Fix the sub expression, which really has to be an 6385 // UnresolvedLookupExpr holding an overloaded member function 6386 // or template. 6387 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(), Fn); 6388 if (SubExpr == UnOp->getSubExpr()) 6389 return UnOp->Retain(); 6390 6391 assert(isa<DeclRefExpr>(SubExpr) 6392 && "fixed to something other than a decl ref"); 6393 assert(cast<DeclRefExpr>(SubExpr)->getQualifier() 6394 && "fixed to a member ref with no nested name qualifier"); 6395 6396 // We have taken the address of a pointer to member 6397 // function. Perform the computation here so that we get the 6398 // appropriate pointer to member type. 6399 QualType ClassType 6400 = Context.getTypeDeclType(cast<RecordDecl>(Method->getDeclContext())); 6401 QualType MemPtrType 6402 = Context.getMemberPointerType(Fn->getType(), ClassType.getTypePtr()); 6403 6404 return new (Context) UnaryOperator(SubExpr, UnaryOperator::AddrOf, 6405 MemPtrType, UnOp->getOperatorLoc()); 6406 } 6407 } 6408 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(), Fn); 6409 if (SubExpr == UnOp->getSubExpr()) 6410 return UnOp->Retain(); 6411 6412 return new (Context) UnaryOperator(SubExpr, UnaryOperator::AddrOf, 6413 Context.getPointerType(SubExpr->getType()), 6414 UnOp->getOperatorLoc()); 6415 } 6416 6417 if (UnresolvedLookupExpr *ULE = dyn_cast<UnresolvedLookupExpr>(E)) { 6418 // FIXME: avoid copy. 6419 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 6420 if (ULE->hasExplicitTemplateArgs()) { 6421 ULE->copyTemplateArgumentsInto(TemplateArgsBuffer); 6422 TemplateArgs = &TemplateArgsBuffer; 6423 } 6424 6425 return DeclRefExpr::Create(Context, 6426 ULE->getQualifier(), 6427 ULE->getQualifierRange(), 6428 Fn, 6429 ULE->getNameLoc(), 6430 Fn->getType(), 6431 TemplateArgs); 6432 } 6433 6434 if (UnresolvedMemberExpr *MemExpr = dyn_cast<UnresolvedMemberExpr>(E)) { 6435 // FIXME: avoid copy. 6436 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 6437 if (MemExpr->hasExplicitTemplateArgs()) { 6438 MemExpr->copyTemplateArgumentsInto(TemplateArgsBuffer); 6439 TemplateArgs = &TemplateArgsBuffer; 6440 } 6441 6442 Expr *Base; 6443 6444 // If we're filling in 6445 if (MemExpr->isImplicitAccess()) { 6446 if (cast<CXXMethodDecl>(Fn)->isStatic()) { 6447 return DeclRefExpr::Create(Context, 6448 MemExpr->getQualifier(), 6449 MemExpr->getQualifierRange(), 6450 Fn, 6451 MemExpr->getMemberLoc(), 6452 Fn->getType(), 6453 TemplateArgs); 6454 } else { 6455 SourceLocation Loc = MemExpr->getMemberLoc(); 6456 if (MemExpr->getQualifier()) 6457 Loc = MemExpr->getQualifierRange().getBegin(); 6458 Base = new (Context) CXXThisExpr(Loc, 6459 MemExpr->getBaseType(), 6460 /*isImplicit=*/true); 6461 } 6462 } else 6463 Base = MemExpr->getBase()->Retain(); 6464 6465 return MemberExpr::Create(Context, Base, 6466 MemExpr->isArrow(), 6467 MemExpr->getQualifier(), 6468 MemExpr->getQualifierRange(), 6469 Fn, 6470 MemExpr->getMemberLoc(), 6471 TemplateArgs, 6472 Fn->getType()); 6473 } 6474 6475 assert(false && "Invalid reference to overloaded function"); 6476 return E->Retain(); 6477} 6478 6479Sema::OwningExprResult Sema::FixOverloadedFunctionReference(OwningExprResult E, 6480 FunctionDecl *Fn) { 6481 return Owned(FixOverloadedFunctionReference((Expr *)E.get(), Fn)); 6482} 6483 6484} // end namespace clang 6485