SemaOverload.cpp revision 5920dbba965a2f2a963313d94be3ff3d2b67ece7
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(1)->isBooleanType() && 152 (getFromType()->isPointerType() || getFromType()->isBlockPointerType() || 153 First == ICK_Array_To_Pointer || First == ICK_Function_To_Pointer)) 154 return true; 155 156 return false; 157} 158 159/// isPointerConversionToVoidPointer - Determines whether this 160/// conversion is a conversion of a pointer to a void pointer. This is 161/// used as part of the ranking of standard conversion sequences (C++ 162/// 13.3.3.2p4). 163bool 164StandardConversionSequence:: 165isPointerConversionToVoidPointer(ASTContext& Context) const { 166 QualType FromType = getFromType(); 167 QualType ToType = getToType(1); 168 169 // Note that FromType has not necessarily been transformed by the 170 // array-to-pointer implicit conversion, so check for its presence 171 // and redo the conversion to get a pointer. 172 if (First == ICK_Array_To_Pointer) 173 FromType = Context.getArrayDecayedType(FromType); 174 175 if (Second == ICK_Pointer_Conversion && FromType->isPointerType()) 176 if (const PointerType* ToPtrType = ToType->getAs<PointerType>()) 177 return ToPtrType->getPointeeType()->isVoidType(); 178 179 return false; 180} 181 182/// DebugPrint - Print this standard conversion sequence to standard 183/// error. Useful for debugging overloading issues. 184void StandardConversionSequence::DebugPrint() const { 185 llvm::raw_ostream &OS = llvm::errs(); 186 bool PrintedSomething = false; 187 if (First != ICK_Identity) { 188 OS << GetImplicitConversionName(First); 189 PrintedSomething = true; 190 } 191 192 if (Second != ICK_Identity) { 193 if (PrintedSomething) { 194 OS << " -> "; 195 } 196 OS << GetImplicitConversionName(Second); 197 198 if (CopyConstructor) { 199 OS << " (by copy constructor)"; 200 } else if (DirectBinding) { 201 OS << " (direct reference binding)"; 202 } else if (ReferenceBinding) { 203 OS << " (reference binding)"; 204 } 205 PrintedSomething = true; 206 } 207 208 if (Third != ICK_Identity) { 209 if (PrintedSomething) { 210 OS << " -> "; 211 } 212 OS << GetImplicitConversionName(Third); 213 PrintedSomething = true; 214 } 215 216 if (!PrintedSomething) { 217 OS << "No conversions required"; 218 } 219} 220 221/// DebugPrint - Print this user-defined conversion sequence to standard 222/// error. Useful for debugging overloading issues. 223void UserDefinedConversionSequence::DebugPrint() const { 224 llvm::raw_ostream &OS = llvm::errs(); 225 if (Before.First || Before.Second || Before.Third) { 226 Before.DebugPrint(); 227 OS << " -> "; 228 } 229 OS << "'" << ConversionFunction->getNameAsString() << "'"; 230 if (After.First || After.Second || After.Third) { 231 OS << " -> "; 232 After.DebugPrint(); 233 } 234} 235 236/// DebugPrint - Print this implicit conversion sequence to standard 237/// error. Useful for debugging overloading issues. 238void ImplicitConversionSequence::DebugPrint() const { 239 llvm::raw_ostream &OS = llvm::errs(); 240 switch (ConversionKind) { 241 case StandardConversion: 242 OS << "Standard conversion: "; 243 Standard.DebugPrint(); 244 break; 245 case UserDefinedConversion: 246 OS << "User-defined conversion: "; 247 UserDefined.DebugPrint(); 248 break; 249 case EllipsisConversion: 250 OS << "Ellipsis conversion"; 251 break; 252 case AmbiguousConversion: 253 OS << "Ambiguous conversion"; 254 break; 255 case BadConversion: 256 OS << "Bad conversion"; 257 break; 258 } 259 260 OS << "\n"; 261} 262 263void AmbiguousConversionSequence::construct() { 264 new (&conversions()) ConversionSet(); 265} 266 267void AmbiguousConversionSequence::destruct() { 268 conversions().~ConversionSet(); 269} 270 271void 272AmbiguousConversionSequence::copyFrom(const AmbiguousConversionSequence &O) { 273 FromTypePtr = O.FromTypePtr; 274 ToTypePtr = O.ToTypePtr; 275 new (&conversions()) ConversionSet(O.conversions()); 276} 277 278 279// IsOverload - Determine whether the given New declaration is an 280// overload of the declarations in Old. This routine returns false if 281// New and Old cannot be overloaded, e.g., if New has the same 282// signature as some function in Old (C++ 1.3.10) or if the Old 283// declarations aren't functions (or function templates) at all. When 284// it does return false, MatchedDecl will point to the decl that New 285// cannot be overloaded with. This decl may be a UsingShadowDecl on 286// top of the underlying declaration. 287// 288// Example: Given the following input: 289// 290// void f(int, float); // #1 291// void f(int, int); // #2 292// int f(int, int); // #3 293// 294// When we process #1, there is no previous declaration of "f", 295// so IsOverload will not be used. 296// 297// When we process #2, Old contains only the FunctionDecl for #1. By 298// comparing the parameter types, we see that #1 and #2 are overloaded 299// (since they have different signatures), so this routine returns 300// false; MatchedDecl is unchanged. 301// 302// When we process #3, Old is an overload set containing #1 and #2. We 303// compare the signatures of #3 to #1 (they're overloaded, so we do 304// nothing) and then #3 to #2. Since the signatures of #3 and #2 are 305// identical (return types of functions are not part of the 306// signature), IsOverload returns false and MatchedDecl will be set to 307// point to the FunctionDecl for #2. 308Sema::OverloadKind 309Sema::CheckOverload(FunctionDecl *New, const LookupResult &Old, 310 NamedDecl *&Match) { 311 for (LookupResult::iterator I = Old.begin(), E = Old.end(); 312 I != E; ++I) { 313 NamedDecl *OldD = (*I)->getUnderlyingDecl(); 314 if (FunctionTemplateDecl *OldT = dyn_cast<FunctionTemplateDecl>(OldD)) { 315 if (!IsOverload(New, OldT->getTemplatedDecl())) { 316 Match = *I; 317 return Ovl_Match; 318 } 319 } else if (FunctionDecl *OldF = dyn_cast<FunctionDecl>(OldD)) { 320 if (!IsOverload(New, OldF)) { 321 Match = *I; 322 return Ovl_Match; 323 } 324 } else if (isa<UsingDecl>(OldD) || isa<TagDecl>(OldD)) { 325 // We can overload with these, which can show up when doing 326 // redeclaration checks for UsingDecls. 327 assert(Old.getLookupKind() == LookupUsingDeclName); 328 } else if (isa<UnresolvedUsingValueDecl>(OldD)) { 329 // Optimistically assume that an unresolved using decl will 330 // overload; if it doesn't, we'll have to diagnose during 331 // template instantiation. 332 } else { 333 // (C++ 13p1): 334 // Only function declarations can be overloaded; object and type 335 // declarations cannot be overloaded. 336 Match = *I; 337 return Ovl_NonFunction; 338 } 339 } 340 341 return Ovl_Overload; 342} 343 344bool Sema::IsOverload(FunctionDecl *New, FunctionDecl *Old) { 345 FunctionTemplateDecl *OldTemplate = Old->getDescribedFunctionTemplate(); 346 FunctionTemplateDecl *NewTemplate = New->getDescribedFunctionTemplate(); 347 348 // C++ [temp.fct]p2: 349 // A function template can be overloaded with other function templates 350 // and with normal (non-template) functions. 351 if ((OldTemplate == 0) != (NewTemplate == 0)) 352 return true; 353 354 // Is the function New an overload of the function Old? 355 QualType OldQType = Context.getCanonicalType(Old->getType()); 356 QualType NewQType = Context.getCanonicalType(New->getType()); 357 358 // Compare the signatures (C++ 1.3.10) of the two functions to 359 // determine whether they are overloads. If we find any mismatch 360 // in the signature, they are overloads. 361 362 // If either of these functions is a K&R-style function (no 363 // prototype), then we consider them to have matching signatures. 364 if (isa<FunctionNoProtoType>(OldQType.getTypePtr()) || 365 isa<FunctionNoProtoType>(NewQType.getTypePtr())) 366 return false; 367 368 FunctionProtoType* OldType = cast<FunctionProtoType>(OldQType); 369 FunctionProtoType* NewType = cast<FunctionProtoType>(NewQType); 370 371 // The signature of a function includes the types of its 372 // parameters (C++ 1.3.10), which includes the presence or absence 373 // of the ellipsis; see C++ DR 357). 374 if (OldQType != NewQType && 375 (OldType->getNumArgs() != NewType->getNumArgs() || 376 OldType->isVariadic() != NewType->isVariadic() || 377 !std::equal(OldType->arg_type_begin(), OldType->arg_type_end(), 378 NewType->arg_type_begin()))) 379 return true; 380 381 // C++ [temp.over.link]p4: 382 // The signature of a function template consists of its function 383 // signature, its return type and its template parameter list. The names 384 // of the template parameters are significant only for establishing the 385 // relationship between the template parameters and the rest of the 386 // signature. 387 // 388 // We check the return type and template parameter lists for function 389 // templates first; the remaining checks follow. 390 if (NewTemplate && 391 (!TemplateParameterListsAreEqual(NewTemplate->getTemplateParameters(), 392 OldTemplate->getTemplateParameters(), 393 false, TPL_TemplateMatch) || 394 OldType->getResultType() != NewType->getResultType())) 395 return true; 396 397 // If the function is a class member, its signature includes the 398 // cv-qualifiers (if any) on the function itself. 399 // 400 // As part of this, also check whether one of the member functions 401 // is static, in which case they are not overloads (C++ 402 // 13.1p2). While not part of the definition of the signature, 403 // this check is important to determine whether these functions 404 // can be overloaded. 405 CXXMethodDecl* OldMethod = dyn_cast<CXXMethodDecl>(Old); 406 CXXMethodDecl* NewMethod = dyn_cast<CXXMethodDecl>(New); 407 if (OldMethod && NewMethod && 408 !OldMethod->isStatic() && !NewMethod->isStatic() && 409 OldMethod->getTypeQualifiers() != NewMethod->getTypeQualifiers()) 410 return true; 411 412 // The signatures match; this is not an overload. 413 return false; 414} 415 416/// TryImplicitConversion - Attempt to perform an implicit conversion 417/// from the given expression (Expr) to the given type (ToType). This 418/// function returns an implicit conversion sequence that can be used 419/// to perform the initialization. Given 420/// 421/// void f(float f); 422/// void g(int i) { f(i); } 423/// 424/// this routine would produce an implicit conversion sequence to 425/// describe the initialization of f from i, which will be a standard 426/// conversion sequence containing an lvalue-to-rvalue conversion (C++ 427/// 4.1) followed by a floating-integral conversion (C++ 4.9). 428// 429/// Note that this routine only determines how the conversion can be 430/// performed; it does not actually perform the conversion. As such, 431/// it will not produce any diagnostics if no conversion is available, 432/// but will instead return an implicit conversion sequence of kind 433/// "BadConversion". 434/// 435/// If @p SuppressUserConversions, then user-defined conversions are 436/// not permitted. 437/// If @p AllowExplicit, then explicit user-defined conversions are 438/// permitted. 439/// If @p ForceRValue, then overloading is performed as if From was an rvalue, 440/// no matter its actual lvalueness. 441/// If @p UserCast, the implicit conversion is being done for a user-specified 442/// cast. 443ImplicitConversionSequence 444Sema::TryImplicitConversion(Expr* From, QualType ToType, 445 bool SuppressUserConversions, 446 bool AllowExplicit, bool ForceRValue, 447 bool InOverloadResolution, 448 bool UserCast) { 449 ImplicitConversionSequence ICS; 450 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.setAllToTypes(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.setAllToTypes(FromType); 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 SCS.setToType(0, FromType); 638 639 // The second conversion can be an integral promotion, floating 640 // point promotion, integral conversion, floating point conversion, 641 // floating-integral conversion, pointer conversion, 642 // pointer-to-member conversion, or boolean conversion (C++ 4p1). 643 // For overloading in C, this can also be a "compatible-type" 644 // conversion. 645 bool IncompatibleObjC = false; 646 if (Context.hasSameUnqualifiedType(FromType, ToType)) { 647 // The unqualified versions of the types are the same: there's no 648 // conversion to do. 649 SCS.Second = ICK_Identity; 650 } else if (IsIntegralPromotion(From, FromType, ToType)) { 651 // Integral promotion (C++ 4.5). 652 SCS.Second = ICK_Integral_Promotion; 653 FromType = ToType.getUnqualifiedType(); 654 } else if (IsFloatingPointPromotion(FromType, ToType)) { 655 // Floating point promotion (C++ 4.6). 656 SCS.Second = ICK_Floating_Promotion; 657 FromType = ToType.getUnqualifiedType(); 658 } else if (IsComplexPromotion(FromType, ToType)) { 659 // Complex promotion (Clang extension) 660 SCS.Second = ICK_Complex_Promotion; 661 FromType = ToType.getUnqualifiedType(); 662 } else if ((FromType->isIntegralType() || FromType->isEnumeralType()) && 663 (ToType->isIntegralType() && !ToType->isEnumeralType())) { 664 // Integral conversions (C++ 4.7). 665 SCS.Second = ICK_Integral_Conversion; 666 FromType = ToType.getUnqualifiedType(); 667 } else if (FromType->isFloatingType() && ToType->isFloatingType()) { 668 // Floating point conversions (C++ 4.8). 669 SCS.Second = ICK_Floating_Conversion; 670 FromType = ToType.getUnqualifiedType(); 671 } else if (FromType->isComplexType() && ToType->isComplexType()) { 672 // Complex conversions (C99 6.3.1.6) 673 SCS.Second = ICK_Complex_Conversion; 674 FromType = ToType.getUnqualifiedType(); 675 } else if ((FromType->isFloatingType() && 676 ToType->isIntegralType() && (!ToType->isBooleanType() && 677 !ToType->isEnumeralType())) || 678 ((FromType->isIntegralType() || FromType->isEnumeralType()) && 679 ToType->isFloatingType())) { 680 // Floating-integral conversions (C++ 4.9). 681 SCS.Second = ICK_Floating_Integral; 682 FromType = ToType.getUnqualifiedType(); 683 } else if ((FromType->isComplexType() && ToType->isArithmeticType()) || 684 (ToType->isComplexType() && FromType->isArithmeticType())) { 685 // Complex-real conversions (C99 6.3.1.7) 686 SCS.Second = ICK_Complex_Real; 687 FromType = ToType.getUnqualifiedType(); 688 } else if (IsPointerConversion(From, FromType, ToType, InOverloadResolution, 689 FromType, IncompatibleObjC)) { 690 // Pointer conversions (C++ 4.10). 691 SCS.Second = ICK_Pointer_Conversion; 692 SCS.IncompatibleObjC = IncompatibleObjC; 693 } else if (IsMemberPointerConversion(From, FromType, ToType, 694 InOverloadResolution, FromType)) { 695 // Pointer to member conversions (4.11). 696 SCS.Second = ICK_Pointer_Member; 697 } else if (ToType->isBooleanType() && 698 (FromType->isArithmeticType() || 699 FromType->isEnumeralType() || 700 FromType->isAnyPointerType() || 701 FromType->isBlockPointerType() || 702 FromType->isMemberPointerType() || 703 FromType->isNullPtrType())) { 704 // Boolean conversions (C++ 4.12). 705 SCS.Second = ICK_Boolean_Conversion; 706 FromType = Context.BoolTy; 707 } else if (!getLangOptions().CPlusPlus && 708 Context.typesAreCompatible(ToType, FromType)) { 709 // Compatible conversions (Clang extension for C function overloading) 710 SCS.Second = ICK_Compatible_Conversion; 711 } else if (IsNoReturnConversion(Context, FromType, ToType, FromType)) { 712 // Treat a conversion that strips "noreturn" as an identity conversion. 713 SCS.Second = ICK_NoReturn_Adjustment; 714 } else { 715 // No second conversion required. 716 SCS.Second = ICK_Identity; 717 } 718 SCS.setToType(1, FromType); 719 720 QualType CanonFrom; 721 QualType CanonTo; 722 // The third conversion can be a qualification conversion (C++ 4p1). 723 if (IsQualificationConversion(FromType, ToType)) { 724 SCS.Third = ICK_Qualification; 725 FromType = ToType; 726 CanonFrom = Context.getCanonicalType(FromType); 727 CanonTo = Context.getCanonicalType(ToType); 728 } else { 729 // No conversion required 730 SCS.Third = ICK_Identity; 731 732 // C++ [over.best.ics]p6: 733 // [...] Any difference in top-level cv-qualification is 734 // subsumed by the initialization itself and does not constitute 735 // a conversion. [...] 736 CanonFrom = Context.getCanonicalType(FromType); 737 CanonTo = Context.getCanonicalType(ToType); 738 if (CanonFrom.getLocalUnqualifiedType() 739 == CanonTo.getLocalUnqualifiedType() && 740 CanonFrom.getLocalCVRQualifiers() != CanonTo.getLocalCVRQualifiers()) { 741 FromType = ToType; 742 CanonFrom = CanonTo; 743 } 744 } 745 SCS.setToType(2, FromType); 746 747 // If we have not converted the argument type to the parameter type, 748 // this is a bad conversion sequence. 749 if (CanonFrom != CanonTo) 750 return false; 751 752 return true; 753} 754 755/// IsIntegralPromotion - Determines whether the conversion from the 756/// expression From (whose potentially-adjusted type is FromType) to 757/// ToType is an integral promotion (C++ 4.5). If so, returns true and 758/// sets PromotedType to the promoted type. 759bool Sema::IsIntegralPromotion(Expr *From, QualType FromType, QualType ToType) { 760 const BuiltinType *To = ToType->getAs<BuiltinType>(); 761 // All integers are built-in. 762 if (!To) { 763 return false; 764 } 765 766 // An rvalue of type char, signed char, unsigned char, short int, or 767 // unsigned short int can be converted to an rvalue of type int if 768 // int can represent all the values of the source type; otherwise, 769 // the source rvalue can be converted to an rvalue of type unsigned 770 // int (C++ 4.5p1). 771 if (FromType->isPromotableIntegerType() && !FromType->isBooleanType()) { 772 if (// We can promote any signed, promotable integer type to an int 773 (FromType->isSignedIntegerType() || 774 // We can promote any unsigned integer type whose size is 775 // less than int to an int. 776 (!FromType->isSignedIntegerType() && 777 Context.getTypeSize(FromType) < Context.getTypeSize(ToType)))) { 778 return To->getKind() == BuiltinType::Int; 779 } 780 781 return To->getKind() == BuiltinType::UInt; 782 } 783 784 // An rvalue of type wchar_t (3.9.1) or an enumeration type (7.2) 785 // can be converted to an rvalue of the first of the following types 786 // that can represent all the values of its underlying type: int, 787 // unsigned int, long, or unsigned long (C++ 4.5p2). 788 789 // We pre-calculate the promotion type for enum types. 790 if (const EnumType *FromEnumType = FromType->getAs<EnumType>()) 791 if (ToType->isIntegerType()) 792 return Context.hasSameUnqualifiedType(ToType, 793 FromEnumType->getDecl()->getPromotionType()); 794 795 if (FromType->isWideCharType() && ToType->isIntegerType()) { 796 // Determine whether the type we're converting from is signed or 797 // unsigned. 798 bool FromIsSigned; 799 uint64_t FromSize = Context.getTypeSize(FromType); 800 801 // FIXME: Is wchar_t signed or unsigned? We assume it's signed for now. 802 FromIsSigned = true; 803 804 // The types we'll try to promote to, in the appropriate 805 // order. Try each of these types. 806 QualType PromoteTypes[6] = { 807 Context.IntTy, Context.UnsignedIntTy, 808 Context.LongTy, Context.UnsignedLongTy , 809 Context.LongLongTy, Context.UnsignedLongLongTy 810 }; 811 for (int Idx = 0; Idx < 6; ++Idx) { 812 uint64_t ToSize = Context.getTypeSize(PromoteTypes[Idx]); 813 if (FromSize < ToSize || 814 (FromSize == ToSize && 815 FromIsSigned == PromoteTypes[Idx]->isSignedIntegerType())) { 816 // We found the type that we can promote to. If this is the 817 // type we wanted, we have a promotion. Otherwise, no 818 // promotion. 819 return Context.hasSameUnqualifiedType(ToType, PromoteTypes[Idx]); 820 } 821 } 822 } 823 824 // An rvalue for an integral bit-field (9.6) can be converted to an 825 // rvalue of type int if int can represent all the values of the 826 // bit-field; otherwise, it can be converted to unsigned int if 827 // unsigned int can represent all the values of the bit-field. If 828 // the bit-field is larger yet, no integral promotion applies to 829 // it. If the bit-field has an enumerated type, it is treated as any 830 // other value of that type for promotion purposes (C++ 4.5p3). 831 // FIXME: We should delay checking of bit-fields until we actually perform the 832 // conversion. 833 using llvm::APSInt; 834 if (From) 835 if (FieldDecl *MemberDecl = From->getBitField()) { 836 APSInt BitWidth; 837 if (FromType->isIntegralType() && !FromType->isEnumeralType() && 838 MemberDecl->getBitWidth()->isIntegerConstantExpr(BitWidth, Context)) { 839 APSInt ToSize(BitWidth.getBitWidth(), BitWidth.isUnsigned()); 840 ToSize = Context.getTypeSize(ToType); 841 842 // Are we promoting to an int from a bitfield that fits in an int? 843 if (BitWidth < ToSize || 844 (FromType->isSignedIntegerType() && BitWidth <= ToSize)) { 845 return To->getKind() == BuiltinType::Int; 846 } 847 848 // Are we promoting to an unsigned int from an unsigned bitfield 849 // that fits into an unsigned int? 850 if (FromType->isUnsignedIntegerType() && BitWidth <= ToSize) { 851 return To->getKind() == BuiltinType::UInt; 852 } 853 854 return false; 855 } 856 } 857 858 // An rvalue of type bool can be converted to an rvalue of type int, 859 // with false becoming zero and true becoming one (C++ 4.5p4). 860 if (FromType->isBooleanType() && To->getKind() == BuiltinType::Int) { 861 return true; 862 } 863 864 return false; 865} 866 867/// IsFloatingPointPromotion - Determines whether the conversion from 868/// FromType to ToType is a floating point promotion (C++ 4.6). If so, 869/// returns true and sets PromotedType to the promoted type. 870bool Sema::IsFloatingPointPromotion(QualType FromType, QualType ToType) { 871 /// An rvalue of type float can be converted to an rvalue of type 872 /// double. (C++ 4.6p1). 873 if (const BuiltinType *FromBuiltin = FromType->getAs<BuiltinType>()) 874 if (const BuiltinType *ToBuiltin = ToType->getAs<BuiltinType>()) { 875 if (FromBuiltin->getKind() == BuiltinType::Float && 876 ToBuiltin->getKind() == BuiltinType::Double) 877 return true; 878 879 // C99 6.3.1.5p1: 880 // When a float is promoted to double or long double, or a 881 // double is promoted to long double [...]. 882 if (!getLangOptions().CPlusPlus && 883 (FromBuiltin->getKind() == BuiltinType::Float || 884 FromBuiltin->getKind() == BuiltinType::Double) && 885 (ToBuiltin->getKind() == BuiltinType::LongDouble)) 886 return true; 887 } 888 889 return false; 890} 891 892/// \brief Determine if a conversion is a complex promotion. 893/// 894/// A complex promotion is defined as a complex -> complex conversion 895/// where the conversion between the underlying real types is a 896/// floating-point or integral promotion. 897bool Sema::IsComplexPromotion(QualType FromType, QualType ToType) { 898 const ComplexType *FromComplex = FromType->getAs<ComplexType>(); 899 if (!FromComplex) 900 return false; 901 902 const ComplexType *ToComplex = ToType->getAs<ComplexType>(); 903 if (!ToComplex) 904 return false; 905 906 return IsFloatingPointPromotion(FromComplex->getElementType(), 907 ToComplex->getElementType()) || 908 IsIntegralPromotion(0, FromComplex->getElementType(), 909 ToComplex->getElementType()); 910} 911 912/// BuildSimilarlyQualifiedPointerType - In a pointer conversion from 913/// the pointer type FromPtr to a pointer to type ToPointee, with the 914/// same type qualifiers as FromPtr has on its pointee type. ToType, 915/// if non-empty, will be a pointer to ToType that may or may not have 916/// the right set of qualifiers on its pointee. 917static QualType 918BuildSimilarlyQualifiedPointerType(const PointerType *FromPtr, 919 QualType ToPointee, QualType ToType, 920 ASTContext &Context) { 921 QualType CanonFromPointee = Context.getCanonicalType(FromPtr->getPointeeType()); 922 QualType CanonToPointee = Context.getCanonicalType(ToPointee); 923 Qualifiers Quals = CanonFromPointee.getQualifiers(); 924 925 // Exact qualifier match -> return the pointer type we're converting to. 926 if (CanonToPointee.getLocalQualifiers() == Quals) { 927 // ToType is exactly what we need. Return it. 928 if (!ToType.isNull()) 929 return ToType; 930 931 // Build a pointer to ToPointee. It has the right qualifiers 932 // already. 933 return Context.getPointerType(ToPointee); 934 } 935 936 // Just build a canonical type that has the right qualifiers. 937 return Context.getPointerType( 938 Context.getQualifiedType(CanonToPointee.getLocalUnqualifiedType(), 939 Quals)); 940} 941 942/// BuildSimilarlyQualifiedObjCObjectPointerType - In a pointer conversion from 943/// the FromType, which is an objective-c pointer, to ToType, which may or may 944/// not have the right set of qualifiers. 945static QualType 946BuildSimilarlyQualifiedObjCObjectPointerType(QualType FromType, 947 QualType ToType, 948 ASTContext &Context) { 949 QualType CanonFromType = Context.getCanonicalType(FromType); 950 QualType CanonToType = Context.getCanonicalType(ToType); 951 Qualifiers Quals = CanonFromType.getQualifiers(); 952 953 // Exact qualifier match -> return the pointer type we're converting to. 954 if (CanonToType.getLocalQualifiers() == Quals) 955 return ToType; 956 957 // Just build a canonical type that has the right qualifiers. 958 return Context.getQualifiedType(CanonToType.getLocalUnqualifiedType(), Quals); 959} 960 961static bool isNullPointerConstantForConversion(Expr *Expr, 962 bool InOverloadResolution, 963 ASTContext &Context) { 964 // Handle value-dependent integral null pointer constants correctly. 965 // http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#903 966 if (Expr->isValueDependent() && !Expr->isTypeDependent() && 967 Expr->getType()->isIntegralType()) 968 return !InOverloadResolution; 969 970 return Expr->isNullPointerConstant(Context, 971 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull 972 : Expr::NPC_ValueDependentIsNull); 973} 974 975/// IsPointerConversion - Determines whether the conversion of the 976/// expression From, which has the (possibly adjusted) type FromType, 977/// can be converted to the type ToType via a pointer conversion (C++ 978/// 4.10). If so, returns true and places the converted type (that 979/// might differ from ToType in its cv-qualifiers at some level) into 980/// ConvertedType. 981/// 982/// This routine also supports conversions to and from block pointers 983/// and conversions with Objective-C's 'id', 'id<protocols...>', and 984/// pointers to interfaces. FIXME: Once we've determined the 985/// appropriate overloading rules for Objective-C, we may want to 986/// split the Objective-C checks into a different routine; however, 987/// GCC seems to consider all of these conversions to be pointer 988/// conversions, so for now they live here. IncompatibleObjC will be 989/// set if the conversion is an allowed Objective-C conversion that 990/// should result in a warning. 991bool Sema::IsPointerConversion(Expr *From, QualType FromType, QualType ToType, 992 bool InOverloadResolution, 993 QualType& ConvertedType, 994 bool &IncompatibleObjC) { 995 IncompatibleObjC = false; 996 if (isObjCPointerConversion(FromType, ToType, ConvertedType, IncompatibleObjC)) 997 return true; 998 999 // Conversion from a null pointer constant to any Objective-C pointer type. 1000 if (ToType->isObjCObjectPointerType() && 1001 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1002 ConvertedType = ToType; 1003 return true; 1004 } 1005 1006 // Blocks: Block pointers can be converted to void*. 1007 if (FromType->isBlockPointerType() && ToType->isPointerType() && 1008 ToType->getAs<PointerType>()->getPointeeType()->isVoidType()) { 1009 ConvertedType = ToType; 1010 return true; 1011 } 1012 // Blocks: A null pointer constant can be converted to a block 1013 // pointer type. 1014 if (ToType->isBlockPointerType() && 1015 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1016 ConvertedType = ToType; 1017 return true; 1018 } 1019 1020 // If the left-hand-side is nullptr_t, the right side can be a null 1021 // pointer constant. 1022 if (ToType->isNullPtrType() && 1023 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1024 ConvertedType = ToType; 1025 return true; 1026 } 1027 1028 const PointerType* ToTypePtr = ToType->getAs<PointerType>(); 1029 if (!ToTypePtr) 1030 return false; 1031 1032 // A null pointer constant can be converted to a pointer type (C++ 4.10p1). 1033 if (isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1034 ConvertedType = ToType; 1035 return true; 1036 } 1037 1038 // Beyond this point, both types need to be pointers 1039 // , including objective-c pointers. 1040 QualType ToPointeeType = ToTypePtr->getPointeeType(); 1041 if (FromType->isObjCObjectPointerType() && ToPointeeType->isVoidType()) { 1042 ConvertedType = BuildSimilarlyQualifiedObjCObjectPointerType(FromType, 1043 ToType, Context); 1044 return true; 1045 1046 } 1047 const PointerType *FromTypePtr = FromType->getAs<PointerType>(); 1048 if (!FromTypePtr) 1049 return false; 1050 1051 QualType FromPointeeType = FromTypePtr->getPointeeType(); 1052 1053 // An rvalue of type "pointer to cv T," where T is an object type, 1054 // can be converted to an rvalue of type "pointer to cv void" (C++ 1055 // 4.10p2). 1056 if (FromPointeeType->isObjectType() && ToPointeeType->isVoidType()) { 1057 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1058 ToPointeeType, 1059 ToType, Context); 1060 return true; 1061 } 1062 1063 // When we're overloading in C, we allow a special kind of pointer 1064 // conversion for compatible-but-not-identical pointee types. 1065 if (!getLangOptions().CPlusPlus && 1066 Context.typesAreCompatible(FromPointeeType, ToPointeeType)) { 1067 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1068 ToPointeeType, 1069 ToType, Context); 1070 return true; 1071 } 1072 1073 // C++ [conv.ptr]p3: 1074 // 1075 // An rvalue of type "pointer to cv D," where D is a class type, 1076 // can be converted to an rvalue of type "pointer to cv B," where 1077 // B is a base class (clause 10) of D. If B is an inaccessible 1078 // (clause 11) or ambiguous (10.2) base class of D, a program that 1079 // necessitates this conversion is ill-formed. The result of the 1080 // conversion is a pointer to the base class sub-object of the 1081 // derived class object. The null pointer value is converted to 1082 // the null pointer value of the destination type. 1083 // 1084 // Note that we do not check for ambiguity or inaccessibility 1085 // here. That is handled by CheckPointerConversion. 1086 if (getLangOptions().CPlusPlus && 1087 FromPointeeType->isRecordType() && ToPointeeType->isRecordType() && 1088 !RequireCompleteType(From->getLocStart(), FromPointeeType, PDiag()) && 1089 IsDerivedFrom(FromPointeeType, ToPointeeType)) { 1090 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1091 ToPointeeType, 1092 ToType, Context); 1093 return true; 1094 } 1095 1096 return false; 1097} 1098 1099/// isObjCPointerConversion - Determines whether this is an 1100/// Objective-C pointer conversion. Subroutine of IsPointerConversion, 1101/// with the same arguments and return values. 1102bool Sema::isObjCPointerConversion(QualType FromType, QualType ToType, 1103 QualType& ConvertedType, 1104 bool &IncompatibleObjC) { 1105 if (!getLangOptions().ObjC1) 1106 return false; 1107 1108 // First, we handle all conversions on ObjC object pointer types. 1109 const ObjCObjectPointerType* ToObjCPtr = ToType->getAs<ObjCObjectPointerType>(); 1110 const ObjCObjectPointerType *FromObjCPtr = 1111 FromType->getAs<ObjCObjectPointerType>(); 1112 1113 if (ToObjCPtr && FromObjCPtr) { 1114 // Objective C++: We're able to convert between "id" or "Class" and a 1115 // pointer to any interface (in both directions). 1116 if (ToObjCPtr->isObjCBuiltinType() && FromObjCPtr->isObjCBuiltinType()) { 1117 ConvertedType = ToType; 1118 return true; 1119 } 1120 // Conversions with Objective-C's id<...>. 1121 if ((FromObjCPtr->isObjCQualifiedIdType() || 1122 ToObjCPtr->isObjCQualifiedIdType()) && 1123 Context.ObjCQualifiedIdTypesAreCompatible(ToType, FromType, 1124 /*compare=*/false)) { 1125 ConvertedType = ToType; 1126 return true; 1127 } 1128 // Objective C++: We're able to convert from a pointer to an 1129 // interface to a pointer to a different interface. 1130 if (Context.canAssignObjCInterfaces(ToObjCPtr, FromObjCPtr)) { 1131 ConvertedType = ToType; 1132 return true; 1133 } 1134 1135 if (Context.canAssignObjCInterfaces(FromObjCPtr, ToObjCPtr)) { 1136 // Okay: this is some kind of implicit downcast of Objective-C 1137 // interfaces, which is permitted. However, we're going to 1138 // complain about it. 1139 IncompatibleObjC = true; 1140 ConvertedType = FromType; 1141 return true; 1142 } 1143 } 1144 // Beyond this point, both types need to be C pointers or block pointers. 1145 QualType ToPointeeType; 1146 if (const PointerType *ToCPtr = ToType->getAs<PointerType>()) 1147 ToPointeeType = ToCPtr->getPointeeType(); 1148 else if (const BlockPointerType *ToBlockPtr = 1149 ToType->getAs<BlockPointerType>()) { 1150 // Objective C++: We're able to convert from a pointer to any object 1151 // to a block pointer type. 1152 if (FromObjCPtr && FromObjCPtr->isObjCBuiltinType()) { 1153 ConvertedType = ToType; 1154 return true; 1155 } 1156 ToPointeeType = ToBlockPtr->getPointeeType(); 1157 } 1158 else if (FromType->getAs<BlockPointerType>() && 1159 ToObjCPtr && ToObjCPtr->isObjCBuiltinType()) { 1160 // Objective C++: We're able to convert from a block pointer type to a 1161 // pointer to any object. 1162 ConvertedType = ToType; 1163 return true; 1164 } 1165 else 1166 return false; 1167 1168 QualType FromPointeeType; 1169 if (const PointerType *FromCPtr = FromType->getAs<PointerType>()) 1170 FromPointeeType = FromCPtr->getPointeeType(); 1171 else if (const BlockPointerType *FromBlockPtr = FromType->getAs<BlockPointerType>()) 1172 FromPointeeType = FromBlockPtr->getPointeeType(); 1173 else 1174 return false; 1175 1176 // If we have pointers to pointers, recursively check whether this 1177 // is an Objective-C conversion. 1178 if (FromPointeeType->isPointerType() && ToPointeeType->isPointerType() && 1179 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, 1180 IncompatibleObjC)) { 1181 // We always complain about this conversion. 1182 IncompatibleObjC = true; 1183 ConvertedType = ToType; 1184 return true; 1185 } 1186 // Allow conversion of pointee being objective-c pointer to another one; 1187 // as in I* to id. 1188 if (FromPointeeType->getAs<ObjCObjectPointerType>() && 1189 ToPointeeType->getAs<ObjCObjectPointerType>() && 1190 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, 1191 IncompatibleObjC)) { 1192 ConvertedType = ToType; 1193 return true; 1194 } 1195 1196 // If we have pointers to functions or blocks, check whether the only 1197 // differences in the argument and result types are in Objective-C 1198 // pointer conversions. If so, we permit the conversion (but 1199 // complain about it). 1200 const FunctionProtoType *FromFunctionType 1201 = FromPointeeType->getAs<FunctionProtoType>(); 1202 const FunctionProtoType *ToFunctionType 1203 = ToPointeeType->getAs<FunctionProtoType>(); 1204 if (FromFunctionType && ToFunctionType) { 1205 // If the function types are exactly the same, this isn't an 1206 // Objective-C pointer conversion. 1207 if (Context.getCanonicalType(FromPointeeType) 1208 == Context.getCanonicalType(ToPointeeType)) 1209 return false; 1210 1211 // Perform the quick checks that will tell us whether these 1212 // function types are obviously different. 1213 if (FromFunctionType->getNumArgs() != ToFunctionType->getNumArgs() || 1214 FromFunctionType->isVariadic() != ToFunctionType->isVariadic() || 1215 FromFunctionType->getTypeQuals() != ToFunctionType->getTypeQuals()) 1216 return false; 1217 1218 bool HasObjCConversion = false; 1219 if (Context.getCanonicalType(FromFunctionType->getResultType()) 1220 == Context.getCanonicalType(ToFunctionType->getResultType())) { 1221 // Okay, the types match exactly. Nothing to do. 1222 } else if (isObjCPointerConversion(FromFunctionType->getResultType(), 1223 ToFunctionType->getResultType(), 1224 ConvertedType, IncompatibleObjC)) { 1225 // Okay, we have an Objective-C pointer conversion. 1226 HasObjCConversion = true; 1227 } else { 1228 // Function types are too different. Abort. 1229 return false; 1230 } 1231 1232 // Check argument types. 1233 for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumArgs(); 1234 ArgIdx != NumArgs; ++ArgIdx) { 1235 QualType FromArgType = FromFunctionType->getArgType(ArgIdx); 1236 QualType ToArgType = ToFunctionType->getArgType(ArgIdx); 1237 if (Context.getCanonicalType(FromArgType) 1238 == Context.getCanonicalType(ToArgType)) { 1239 // Okay, the types match exactly. Nothing to do. 1240 } else if (isObjCPointerConversion(FromArgType, ToArgType, 1241 ConvertedType, IncompatibleObjC)) { 1242 // Okay, we have an Objective-C pointer conversion. 1243 HasObjCConversion = true; 1244 } else { 1245 // Argument types are too different. Abort. 1246 return false; 1247 } 1248 } 1249 1250 if (HasObjCConversion) { 1251 // We had an Objective-C conversion. Allow this pointer 1252 // conversion, but complain about it. 1253 ConvertedType = ToType; 1254 IncompatibleObjC = true; 1255 return true; 1256 } 1257 } 1258 1259 return false; 1260} 1261 1262/// CheckPointerConversion - Check the pointer conversion from the 1263/// expression From to the type ToType. This routine checks for 1264/// ambiguous or inaccessible derived-to-base pointer 1265/// conversions for which IsPointerConversion has already returned 1266/// true. It returns true and produces a diagnostic if there was an 1267/// error, or returns false otherwise. 1268bool Sema::CheckPointerConversion(Expr *From, QualType ToType, 1269 CastExpr::CastKind &Kind, 1270 bool IgnoreBaseAccess) { 1271 QualType FromType = From->getType(); 1272 1273 if (const PointerType *FromPtrType = FromType->getAs<PointerType>()) 1274 if (const PointerType *ToPtrType = ToType->getAs<PointerType>()) { 1275 QualType FromPointeeType = FromPtrType->getPointeeType(), 1276 ToPointeeType = ToPtrType->getPointeeType(); 1277 1278 if (FromPointeeType->isRecordType() && 1279 ToPointeeType->isRecordType()) { 1280 // We must have a derived-to-base conversion. Check an 1281 // ambiguous or inaccessible conversion. 1282 if (CheckDerivedToBaseConversion(FromPointeeType, ToPointeeType, 1283 From->getExprLoc(), 1284 From->getSourceRange(), 1285 IgnoreBaseAccess)) 1286 return true; 1287 1288 // The conversion was successful. 1289 Kind = CastExpr::CK_DerivedToBase; 1290 } 1291 } 1292 if (const ObjCObjectPointerType *FromPtrType = 1293 FromType->getAs<ObjCObjectPointerType>()) 1294 if (const ObjCObjectPointerType *ToPtrType = 1295 ToType->getAs<ObjCObjectPointerType>()) { 1296 // Objective-C++ conversions are always okay. 1297 // FIXME: We should have a different class of conversions for the 1298 // Objective-C++ implicit conversions. 1299 if (FromPtrType->isObjCBuiltinType() || ToPtrType->isObjCBuiltinType()) 1300 return false; 1301 1302 } 1303 return false; 1304} 1305 1306/// IsMemberPointerConversion - Determines whether the conversion of the 1307/// expression From, which has the (possibly adjusted) type FromType, can be 1308/// converted to the type ToType via a member pointer conversion (C++ 4.11). 1309/// If so, returns true and places the converted type (that might differ from 1310/// ToType in its cv-qualifiers at some level) into ConvertedType. 1311bool Sema::IsMemberPointerConversion(Expr *From, QualType FromType, 1312 QualType ToType, 1313 bool InOverloadResolution, 1314 QualType &ConvertedType) { 1315 const MemberPointerType *ToTypePtr = ToType->getAs<MemberPointerType>(); 1316 if (!ToTypePtr) 1317 return false; 1318 1319 // A null pointer constant can be converted to a member pointer (C++ 4.11p1) 1320 if (From->isNullPointerConstant(Context, 1321 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull 1322 : Expr::NPC_ValueDependentIsNull)) { 1323 ConvertedType = ToType; 1324 return true; 1325 } 1326 1327 // Otherwise, both types have to be member pointers. 1328 const MemberPointerType *FromTypePtr = FromType->getAs<MemberPointerType>(); 1329 if (!FromTypePtr) 1330 return false; 1331 1332 // A pointer to member of B can be converted to a pointer to member of D, 1333 // where D is derived from B (C++ 4.11p2). 1334 QualType FromClass(FromTypePtr->getClass(), 0); 1335 QualType ToClass(ToTypePtr->getClass(), 0); 1336 // FIXME: What happens when these are dependent? Is this function even called? 1337 1338 if (IsDerivedFrom(ToClass, FromClass)) { 1339 ConvertedType = Context.getMemberPointerType(FromTypePtr->getPointeeType(), 1340 ToClass.getTypePtr()); 1341 return true; 1342 } 1343 1344 return false; 1345} 1346 1347/// CheckMemberPointerConversion - Check the member pointer conversion from the 1348/// expression From to the type ToType. This routine checks for ambiguous or 1349/// virtual (FIXME: or inaccessible) base-to-derived member pointer conversions 1350/// for which IsMemberPointerConversion has already returned true. It returns 1351/// true and produces a diagnostic if there was an error, or returns false 1352/// otherwise. 1353bool Sema::CheckMemberPointerConversion(Expr *From, QualType ToType, 1354 CastExpr::CastKind &Kind, 1355 bool IgnoreBaseAccess) { 1356 (void)IgnoreBaseAccess; 1357 QualType FromType = From->getType(); 1358 const MemberPointerType *FromPtrType = FromType->getAs<MemberPointerType>(); 1359 if (!FromPtrType) { 1360 // This must be a null pointer to member pointer conversion 1361 assert(From->isNullPointerConstant(Context, 1362 Expr::NPC_ValueDependentIsNull) && 1363 "Expr must be null pointer constant!"); 1364 Kind = CastExpr::CK_NullToMemberPointer; 1365 return false; 1366 } 1367 1368 const MemberPointerType *ToPtrType = ToType->getAs<MemberPointerType>(); 1369 assert(ToPtrType && "No member pointer cast has a target type " 1370 "that is not a member pointer."); 1371 1372 QualType FromClass = QualType(FromPtrType->getClass(), 0); 1373 QualType ToClass = QualType(ToPtrType->getClass(), 0); 1374 1375 // FIXME: What about dependent types? 1376 assert(FromClass->isRecordType() && "Pointer into non-class."); 1377 assert(ToClass->isRecordType() && "Pointer into non-class."); 1378 1379 CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/false, 1380 /*DetectVirtual=*/true); 1381 bool DerivationOkay = IsDerivedFrom(ToClass, FromClass, Paths); 1382 assert(DerivationOkay && 1383 "Should not have been called if derivation isn't OK."); 1384 (void)DerivationOkay; 1385 1386 if (Paths.isAmbiguous(Context.getCanonicalType(FromClass). 1387 getUnqualifiedType())) { 1388 // Derivation is ambiguous. Redo the check to find the exact paths. 1389 Paths.clear(); 1390 Paths.setRecordingPaths(true); 1391 bool StillOkay = IsDerivedFrom(ToClass, FromClass, Paths); 1392 assert(StillOkay && "Derivation changed due to quantum fluctuation."); 1393 (void)StillOkay; 1394 1395 std::string PathDisplayStr = getAmbiguousPathsDisplayString(Paths); 1396 Diag(From->getExprLoc(), diag::err_ambiguous_memptr_conv) 1397 << 0 << FromClass << ToClass << PathDisplayStr << From->getSourceRange(); 1398 return true; 1399 } 1400 1401 if (const RecordType *VBase = Paths.getDetectedVirtual()) { 1402 Diag(From->getExprLoc(), diag::err_memptr_conv_via_virtual) 1403 << FromClass << ToClass << QualType(VBase, 0) 1404 << From->getSourceRange(); 1405 return true; 1406 } 1407 1408 // Must be a base to derived member conversion. 1409 Kind = CastExpr::CK_BaseToDerivedMemberPointer; 1410 return false; 1411} 1412 1413/// IsQualificationConversion - Determines whether the conversion from 1414/// an rvalue of type FromType to ToType is a qualification conversion 1415/// (C++ 4.4). 1416bool 1417Sema::IsQualificationConversion(QualType FromType, QualType ToType) { 1418 FromType = Context.getCanonicalType(FromType); 1419 ToType = Context.getCanonicalType(ToType); 1420 1421 // If FromType and ToType are the same type, this is not a 1422 // qualification conversion. 1423 if (FromType == ToType) 1424 return false; 1425 1426 // (C++ 4.4p4): 1427 // A conversion can add cv-qualifiers at levels other than the first 1428 // in multi-level pointers, subject to the following rules: [...] 1429 bool PreviousToQualsIncludeConst = true; 1430 bool UnwrappedAnyPointer = false; 1431 while (UnwrapSimilarPointerTypes(FromType, ToType)) { 1432 // Within each iteration of the loop, we check the qualifiers to 1433 // determine if this still looks like a qualification 1434 // conversion. Then, if all is well, we unwrap one more level of 1435 // pointers or pointers-to-members and do it all again 1436 // until there are no more pointers or pointers-to-members left to 1437 // unwrap. 1438 UnwrappedAnyPointer = true; 1439 1440 // -- for every j > 0, if const is in cv 1,j then const is in cv 1441 // 2,j, and similarly for volatile. 1442 if (!ToType.isAtLeastAsQualifiedAs(FromType)) 1443 return false; 1444 1445 // -- if the cv 1,j and cv 2,j are different, then const is in 1446 // every cv for 0 < k < j. 1447 if (FromType.getCVRQualifiers() != ToType.getCVRQualifiers() 1448 && !PreviousToQualsIncludeConst) 1449 return false; 1450 1451 // Keep track of whether all prior cv-qualifiers in the "to" type 1452 // include const. 1453 PreviousToQualsIncludeConst 1454 = PreviousToQualsIncludeConst && ToType.isConstQualified(); 1455 } 1456 1457 // We are left with FromType and ToType being the pointee types 1458 // after unwrapping the original FromType and ToType the same number 1459 // of types. If we unwrapped any pointers, and if FromType and 1460 // ToType have the same unqualified type (since we checked 1461 // qualifiers above), then this is a qualification conversion. 1462 return UnwrappedAnyPointer && Context.hasSameUnqualifiedType(FromType,ToType); 1463} 1464 1465/// Determines whether there is a user-defined conversion sequence 1466/// (C++ [over.ics.user]) that converts expression From to the type 1467/// ToType. If such a conversion exists, User will contain the 1468/// user-defined conversion sequence that performs such a conversion 1469/// and this routine will return true. Otherwise, this routine returns 1470/// false and User is unspecified. 1471/// 1472/// \param AllowConversionFunctions true if the conversion should 1473/// consider conversion functions at all. If false, only constructors 1474/// will be considered. 1475/// 1476/// \param AllowExplicit true if the conversion should consider C++0x 1477/// "explicit" conversion functions as well as non-explicit conversion 1478/// functions (C++0x [class.conv.fct]p2). 1479/// 1480/// \param ForceRValue true if the expression should be treated as an rvalue 1481/// for overload resolution. 1482/// \param UserCast true if looking for user defined conversion for a static 1483/// cast. 1484OverloadingResult Sema::IsUserDefinedConversion(Expr *From, QualType ToType, 1485 UserDefinedConversionSequence& User, 1486 OverloadCandidateSet& CandidateSet, 1487 bool AllowConversionFunctions, 1488 bool AllowExplicit, 1489 bool ForceRValue, 1490 bool UserCast) { 1491 if (const RecordType *ToRecordType = ToType->getAs<RecordType>()) { 1492 if (RequireCompleteType(From->getLocStart(), ToType, PDiag())) { 1493 // We're not going to find any constructors. 1494 } else if (CXXRecordDecl *ToRecordDecl 1495 = dyn_cast<CXXRecordDecl>(ToRecordType->getDecl())) { 1496 // C++ [over.match.ctor]p1: 1497 // When objects of class type are direct-initialized (8.5), or 1498 // copy-initialized from an expression of the same or a 1499 // derived class type (8.5), overload resolution selects the 1500 // constructor. [...] For copy-initialization, the candidate 1501 // functions are all the converting constructors (12.3.1) of 1502 // that class. The argument list is the expression-list within 1503 // the parentheses of the initializer. 1504 bool SuppressUserConversions = !UserCast; 1505 if (Context.hasSameUnqualifiedType(ToType, From->getType()) || 1506 IsDerivedFrom(From->getType(), ToType)) { 1507 SuppressUserConversions = false; 1508 AllowConversionFunctions = false; 1509 } 1510 1511 DeclarationName ConstructorName 1512 = Context.DeclarationNames.getCXXConstructorName( 1513 Context.getCanonicalType(ToType).getUnqualifiedType()); 1514 DeclContext::lookup_iterator Con, ConEnd; 1515 for (llvm::tie(Con, ConEnd) 1516 = ToRecordDecl->lookup(ConstructorName); 1517 Con != ConEnd; ++Con) { 1518 // Find the constructor (which may be a template). 1519 CXXConstructorDecl *Constructor = 0; 1520 FunctionTemplateDecl *ConstructorTmpl 1521 = dyn_cast<FunctionTemplateDecl>(*Con); 1522 if (ConstructorTmpl) 1523 Constructor 1524 = cast<CXXConstructorDecl>(ConstructorTmpl->getTemplatedDecl()); 1525 else 1526 Constructor = cast<CXXConstructorDecl>(*Con); 1527 1528 if (!Constructor->isInvalidDecl() && 1529 Constructor->isConvertingConstructor(AllowExplicit)) { 1530 if (ConstructorTmpl) 1531 AddTemplateOverloadCandidate(ConstructorTmpl, 1532 ConstructorTmpl->getAccess(), 1533 /*ExplicitArgs*/ 0, 1534 &From, 1, CandidateSet, 1535 SuppressUserConversions, ForceRValue); 1536 else 1537 // Allow one user-defined conversion when user specifies a 1538 // From->ToType conversion via an static cast (c-style, etc). 1539 AddOverloadCandidate(Constructor, Constructor->getAccess(), 1540 &From, 1, CandidateSet, 1541 SuppressUserConversions, ForceRValue); 1542 } 1543 } 1544 } 1545 } 1546 1547 if (!AllowConversionFunctions) { 1548 // Don't allow any conversion functions to enter the overload set. 1549 } else if (RequireCompleteType(From->getLocStart(), From->getType(), 1550 PDiag(0) 1551 << From->getSourceRange())) { 1552 // No conversion functions from incomplete types. 1553 } else if (const RecordType *FromRecordType 1554 = From->getType()->getAs<RecordType>()) { 1555 if (CXXRecordDecl *FromRecordDecl 1556 = dyn_cast<CXXRecordDecl>(FromRecordType->getDecl())) { 1557 // Add all of the conversion functions as candidates. 1558 const UnresolvedSetImpl *Conversions 1559 = FromRecordDecl->getVisibleConversionFunctions(); 1560 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 1561 E = Conversions->end(); I != E; ++I) { 1562 NamedDecl *D = *I; 1563 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext()); 1564 if (isa<UsingShadowDecl>(D)) 1565 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 1566 1567 CXXConversionDecl *Conv; 1568 FunctionTemplateDecl *ConvTemplate; 1569 if ((ConvTemplate = dyn_cast<FunctionTemplateDecl>(*I))) 1570 Conv = dyn_cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 1571 else 1572 Conv = dyn_cast<CXXConversionDecl>(*I); 1573 1574 if (AllowExplicit || !Conv->isExplicit()) { 1575 if (ConvTemplate) 1576 AddTemplateConversionCandidate(ConvTemplate, I.getAccess(), 1577 ActingContext, From, ToType, 1578 CandidateSet); 1579 else 1580 AddConversionCandidate(Conv, I.getAccess(), ActingContext, 1581 From, ToType, CandidateSet); 1582 } 1583 } 1584 } 1585 } 1586 1587 OverloadCandidateSet::iterator Best; 1588 switch (BestViableFunction(CandidateSet, From->getLocStart(), Best)) { 1589 case OR_Success: 1590 // Record the standard conversion we used and the conversion function. 1591 if (CXXConstructorDecl *Constructor 1592 = dyn_cast<CXXConstructorDecl>(Best->Function)) { 1593 // C++ [over.ics.user]p1: 1594 // If the user-defined conversion is specified by a 1595 // constructor (12.3.1), the initial standard conversion 1596 // sequence converts the source type to the type required by 1597 // the argument of the constructor. 1598 // 1599 QualType ThisType = Constructor->getThisType(Context); 1600 if (Best->Conversions[0].isEllipsis()) 1601 User.EllipsisConversion = true; 1602 else { 1603 User.Before = Best->Conversions[0].Standard; 1604 User.EllipsisConversion = false; 1605 } 1606 User.ConversionFunction = Constructor; 1607 User.After.setAsIdentityConversion(); 1608 User.After.setFromType( 1609 ThisType->getAs<PointerType>()->getPointeeType()); 1610 User.After.setAllToTypes(ToType); 1611 return OR_Success; 1612 } else if (CXXConversionDecl *Conversion 1613 = dyn_cast<CXXConversionDecl>(Best->Function)) { 1614 // C++ [over.ics.user]p1: 1615 // 1616 // [...] If the user-defined conversion is specified by a 1617 // conversion function (12.3.2), the initial standard 1618 // conversion sequence converts the source type to the 1619 // implicit object parameter of the conversion function. 1620 User.Before = Best->Conversions[0].Standard; 1621 User.ConversionFunction = Conversion; 1622 User.EllipsisConversion = false; 1623 1624 // C++ [over.ics.user]p2: 1625 // The second standard conversion sequence converts the 1626 // result of the user-defined conversion to the target type 1627 // for the sequence. Since an implicit conversion sequence 1628 // is an initialization, the special rules for 1629 // initialization by user-defined conversion apply when 1630 // selecting the best user-defined conversion for a 1631 // user-defined conversion sequence (see 13.3.3 and 1632 // 13.3.3.1). 1633 User.After = Best->FinalConversion; 1634 return OR_Success; 1635 } else { 1636 assert(false && "Not a constructor or conversion function?"); 1637 return OR_No_Viable_Function; 1638 } 1639 1640 case OR_No_Viable_Function: 1641 return OR_No_Viable_Function; 1642 case OR_Deleted: 1643 // No conversion here! We're done. 1644 return OR_Deleted; 1645 1646 case OR_Ambiguous: 1647 return OR_Ambiguous; 1648 } 1649 1650 return OR_No_Viable_Function; 1651} 1652 1653bool 1654Sema::DiagnoseMultipleUserDefinedConversion(Expr *From, QualType ToType) { 1655 ImplicitConversionSequence ICS; 1656 OverloadCandidateSet CandidateSet; 1657 OverloadingResult OvResult = 1658 IsUserDefinedConversion(From, ToType, ICS.UserDefined, 1659 CandidateSet, true, false, false); 1660 if (OvResult == OR_Ambiguous) 1661 Diag(From->getSourceRange().getBegin(), 1662 diag::err_typecheck_ambiguous_condition) 1663 << From->getType() << ToType << From->getSourceRange(); 1664 else if (OvResult == OR_No_Viable_Function && !CandidateSet.empty()) 1665 Diag(From->getSourceRange().getBegin(), 1666 diag::err_typecheck_nonviable_condition) 1667 << From->getType() << ToType << From->getSourceRange(); 1668 else 1669 return false; 1670 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, &From, 1); 1671 return true; 1672} 1673 1674/// CompareImplicitConversionSequences - Compare two implicit 1675/// conversion sequences to determine whether one is better than the 1676/// other or if they are indistinguishable (C++ 13.3.3.2). 1677ImplicitConversionSequence::CompareKind 1678Sema::CompareImplicitConversionSequences(const ImplicitConversionSequence& ICS1, 1679 const ImplicitConversionSequence& ICS2) 1680{ 1681 // (C++ 13.3.3.2p2): When comparing the basic forms of implicit 1682 // conversion sequences (as defined in 13.3.3.1) 1683 // -- a standard conversion sequence (13.3.3.1.1) is a better 1684 // conversion sequence than a user-defined conversion sequence or 1685 // an ellipsis conversion sequence, and 1686 // -- a user-defined conversion sequence (13.3.3.1.2) is a better 1687 // conversion sequence than an ellipsis conversion sequence 1688 // (13.3.3.1.3). 1689 // 1690 // C++0x [over.best.ics]p10: 1691 // For the purpose of ranking implicit conversion sequences as 1692 // described in 13.3.3.2, the ambiguous conversion sequence is 1693 // treated as a user-defined sequence that is indistinguishable 1694 // from any other user-defined conversion sequence. 1695 if (ICS1.getKind() < ICS2.getKind()) { 1696 if (!(ICS1.isUserDefined() && ICS2.isAmbiguous())) 1697 return ImplicitConversionSequence::Better; 1698 } else if (ICS2.getKind() < ICS1.getKind()) { 1699 if (!(ICS2.isUserDefined() && ICS1.isAmbiguous())) 1700 return ImplicitConversionSequence::Worse; 1701 } 1702 1703 if (ICS1.isAmbiguous() || ICS2.isAmbiguous()) 1704 return ImplicitConversionSequence::Indistinguishable; 1705 1706 // Two implicit conversion sequences of the same form are 1707 // indistinguishable conversion sequences unless one of the 1708 // following rules apply: (C++ 13.3.3.2p3): 1709 if (ICS1.isStandard()) 1710 return CompareStandardConversionSequences(ICS1.Standard, ICS2.Standard); 1711 else if (ICS1.isUserDefined()) { 1712 // User-defined conversion sequence U1 is a better conversion 1713 // sequence than another user-defined conversion sequence U2 if 1714 // they contain the same user-defined conversion function or 1715 // constructor and if the second standard conversion sequence of 1716 // U1 is better than the second standard conversion sequence of 1717 // U2 (C++ 13.3.3.2p3). 1718 if (ICS1.UserDefined.ConversionFunction == 1719 ICS2.UserDefined.ConversionFunction) 1720 return CompareStandardConversionSequences(ICS1.UserDefined.After, 1721 ICS2.UserDefined.After); 1722 } 1723 1724 return ImplicitConversionSequence::Indistinguishable; 1725} 1726 1727// Per 13.3.3.2p3, compare the given standard conversion sequences to 1728// determine if one is a proper subset of the other. 1729static ImplicitConversionSequence::CompareKind 1730compareStandardConversionSubsets(ASTContext &Context, 1731 const StandardConversionSequence& SCS1, 1732 const StandardConversionSequence& SCS2) { 1733 ImplicitConversionSequence::CompareKind Result 1734 = ImplicitConversionSequence::Indistinguishable; 1735 1736 if (SCS1.Second != SCS2.Second) { 1737 if (SCS1.Second == ICK_Identity) 1738 Result = ImplicitConversionSequence::Better; 1739 else if (SCS2.Second == ICK_Identity) 1740 Result = ImplicitConversionSequence::Worse; 1741 else 1742 return ImplicitConversionSequence::Indistinguishable; 1743 } else if (!Context.hasSameType(SCS1.getToType(1), SCS2.getToType(1))) 1744 return ImplicitConversionSequence::Indistinguishable; 1745 1746 if (SCS1.Third == SCS2.Third) { 1747 return Context.hasSameType(SCS1.getToType(2), SCS2.getToType(2))? Result 1748 : ImplicitConversionSequence::Indistinguishable; 1749 } 1750 1751 if (SCS1.Third == ICK_Identity) 1752 return Result == ImplicitConversionSequence::Worse 1753 ? ImplicitConversionSequence::Indistinguishable 1754 : ImplicitConversionSequence::Better; 1755 1756 if (SCS2.Third == ICK_Identity) 1757 return Result == ImplicitConversionSequence::Better 1758 ? ImplicitConversionSequence::Indistinguishable 1759 : ImplicitConversionSequence::Worse; 1760 1761 return ImplicitConversionSequence::Indistinguishable; 1762} 1763 1764/// CompareStandardConversionSequences - Compare two standard 1765/// conversion sequences to determine whether one is better than the 1766/// other or if they are indistinguishable (C++ 13.3.3.2p3). 1767ImplicitConversionSequence::CompareKind 1768Sema::CompareStandardConversionSequences(const StandardConversionSequence& SCS1, 1769 const StandardConversionSequence& SCS2) 1770{ 1771 // Standard conversion sequence S1 is a better conversion sequence 1772 // than standard conversion sequence S2 if (C++ 13.3.3.2p3): 1773 1774 // -- S1 is a proper subsequence of S2 (comparing the conversion 1775 // sequences in the canonical form defined by 13.3.3.1.1, 1776 // excluding any Lvalue Transformation; the identity conversion 1777 // sequence is considered to be a subsequence of any 1778 // non-identity conversion sequence) or, if not that, 1779 if (ImplicitConversionSequence::CompareKind CK 1780 = compareStandardConversionSubsets(Context, SCS1, SCS2)) 1781 return CK; 1782 1783 // -- the rank of S1 is better than the rank of S2 (by the rules 1784 // defined below), or, if not that, 1785 ImplicitConversionRank Rank1 = SCS1.getRank(); 1786 ImplicitConversionRank Rank2 = SCS2.getRank(); 1787 if (Rank1 < Rank2) 1788 return ImplicitConversionSequence::Better; 1789 else if (Rank2 < Rank1) 1790 return ImplicitConversionSequence::Worse; 1791 1792 // (C++ 13.3.3.2p4): Two conversion sequences with the same rank 1793 // are indistinguishable unless one of the following rules 1794 // applies: 1795 1796 // A conversion that is not a conversion of a pointer, or 1797 // pointer to member, to bool is better than another conversion 1798 // that is such a conversion. 1799 if (SCS1.isPointerConversionToBool() != SCS2.isPointerConversionToBool()) 1800 return SCS2.isPointerConversionToBool() 1801 ? ImplicitConversionSequence::Better 1802 : ImplicitConversionSequence::Worse; 1803 1804 // C++ [over.ics.rank]p4b2: 1805 // 1806 // If class B is derived directly or indirectly from class A, 1807 // conversion of B* to A* is better than conversion of B* to 1808 // void*, and conversion of A* to void* is better than conversion 1809 // of B* to void*. 1810 bool SCS1ConvertsToVoid 1811 = SCS1.isPointerConversionToVoidPointer(Context); 1812 bool SCS2ConvertsToVoid 1813 = SCS2.isPointerConversionToVoidPointer(Context); 1814 if (SCS1ConvertsToVoid != SCS2ConvertsToVoid) { 1815 // Exactly one of the conversion sequences is a conversion to 1816 // a void pointer; it's the worse conversion. 1817 return SCS2ConvertsToVoid ? ImplicitConversionSequence::Better 1818 : ImplicitConversionSequence::Worse; 1819 } else if (!SCS1ConvertsToVoid && !SCS2ConvertsToVoid) { 1820 // Neither conversion sequence converts to a void pointer; compare 1821 // their derived-to-base conversions. 1822 if (ImplicitConversionSequence::CompareKind DerivedCK 1823 = CompareDerivedToBaseConversions(SCS1, SCS2)) 1824 return DerivedCK; 1825 } else if (SCS1ConvertsToVoid && SCS2ConvertsToVoid) { 1826 // Both conversion sequences are conversions to void 1827 // pointers. Compare the source types to determine if there's an 1828 // inheritance relationship in their sources. 1829 QualType FromType1 = SCS1.getFromType(); 1830 QualType FromType2 = SCS2.getFromType(); 1831 1832 // Adjust the types we're converting from via the array-to-pointer 1833 // conversion, if we need to. 1834 if (SCS1.First == ICK_Array_To_Pointer) 1835 FromType1 = Context.getArrayDecayedType(FromType1); 1836 if (SCS2.First == ICK_Array_To_Pointer) 1837 FromType2 = Context.getArrayDecayedType(FromType2); 1838 1839 QualType FromPointee1 1840 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1841 QualType FromPointee2 1842 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1843 1844 if (IsDerivedFrom(FromPointee2, FromPointee1)) 1845 return ImplicitConversionSequence::Better; 1846 else if (IsDerivedFrom(FromPointee1, FromPointee2)) 1847 return ImplicitConversionSequence::Worse; 1848 1849 // Objective-C++: If one interface is more specific than the 1850 // other, it is the better one. 1851 const ObjCInterfaceType* FromIface1 = FromPointee1->getAs<ObjCInterfaceType>(); 1852 const ObjCInterfaceType* FromIface2 = FromPointee2->getAs<ObjCInterfaceType>(); 1853 if (FromIface1 && FromIface1) { 1854 if (Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 1855 return ImplicitConversionSequence::Better; 1856 else if (Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 1857 return ImplicitConversionSequence::Worse; 1858 } 1859 } 1860 1861 // Compare based on qualification conversions (C++ 13.3.3.2p3, 1862 // bullet 3). 1863 if (ImplicitConversionSequence::CompareKind QualCK 1864 = CompareQualificationConversions(SCS1, SCS2)) 1865 return QualCK; 1866 1867 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding) { 1868 // C++0x [over.ics.rank]p3b4: 1869 // -- S1 and S2 are reference bindings (8.5.3) and neither refers to an 1870 // implicit object parameter of a non-static member function declared 1871 // without a ref-qualifier, and S1 binds an rvalue reference to an 1872 // rvalue and S2 binds an lvalue reference. 1873 // FIXME: We don't know if we're dealing with the implicit object parameter, 1874 // or if the member function in this case has a ref qualifier. 1875 // (Of course, we don't have ref qualifiers yet.) 1876 if (SCS1.RRefBinding != SCS2.RRefBinding) 1877 return SCS1.RRefBinding ? ImplicitConversionSequence::Better 1878 : ImplicitConversionSequence::Worse; 1879 1880 // C++ [over.ics.rank]p3b4: 1881 // -- S1 and S2 are reference bindings (8.5.3), and the types to 1882 // which the references refer are the same type except for 1883 // top-level cv-qualifiers, and the type to which the reference 1884 // initialized by S2 refers is more cv-qualified than the type 1885 // to which the reference initialized by S1 refers. 1886 QualType T1 = SCS1.getToType(2); 1887 QualType T2 = SCS2.getToType(2); 1888 T1 = Context.getCanonicalType(T1); 1889 T2 = Context.getCanonicalType(T2); 1890 Qualifiers T1Quals, T2Quals; 1891 QualType UnqualT1 = Context.getUnqualifiedArrayType(T1, T1Quals); 1892 QualType UnqualT2 = Context.getUnqualifiedArrayType(T2, T2Quals); 1893 if (UnqualT1 == UnqualT2) { 1894 // If the type is an array type, promote the element qualifiers to the type 1895 // for comparison. 1896 if (isa<ArrayType>(T1) && T1Quals) 1897 T1 = Context.getQualifiedType(UnqualT1, T1Quals); 1898 if (isa<ArrayType>(T2) && T2Quals) 1899 T2 = Context.getQualifiedType(UnqualT2, T2Quals); 1900 if (T2.isMoreQualifiedThan(T1)) 1901 return ImplicitConversionSequence::Better; 1902 else if (T1.isMoreQualifiedThan(T2)) 1903 return ImplicitConversionSequence::Worse; 1904 } 1905 } 1906 1907 return ImplicitConversionSequence::Indistinguishable; 1908} 1909 1910/// CompareQualificationConversions - Compares two standard conversion 1911/// sequences to determine whether they can be ranked based on their 1912/// qualification conversions (C++ 13.3.3.2p3 bullet 3). 1913ImplicitConversionSequence::CompareKind 1914Sema::CompareQualificationConversions(const StandardConversionSequence& SCS1, 1915 const StandardConversionSequence& SCS2) { 1916 // C++ 13.3.3.2p3: 1917 // -- S1 and S2 differ only in their qualification conversion and 1918 // yield similar types T1 and T2 (C++ 4.4), respectively, and the 1919 // cv-qualification signature of type T1 is a proper subset of 1920 // the cv-qualification signature of type T2, and S1 is not the 1921 // deprecated string literal array-to-pointer conversion (4.2). 1922 if (SCS1.First != SCS2.First || SCS1.Second != SCS2.Second || 1923 SCS1.Third != SCS2.Third || SCS1.Third != ICK_Qualification) 1924 return ImplicitConversionSequence::Indistinguishable; 1925 1926 // FIXME: the example in the standard doesn't use a qualification 1927 // conversion (!) 1928 QualType T1 = SCS1.getToType(2); 1929 QualType T2 = SCS2.getToType(2); 1930 T1 = Context.getCanonicalType(T1); 1931 T2 = Context.getCanonicalType(T2); 1932 Qualifiers T1Quals, T2Quals; 1933 QualType UnqualT1 = Context.getUnqualifiedArrayType(T1, T1Quals); 1934 QualType UnqualT2 = Context.getUnqualifiedArrayType(T2, T2Quals); 1935 1936 // If the types are the same, we won't learn anything by unwrapped 1937 // them. 1938 if (UnqualT1 == UnqualT2) 1939 return ImplicitConversionSequence::Indistinguishable; 1940 1941 // If the type is an array type, promote the element qualifiers to the type 1942 // for comparison. 1943 if (isa<ArrayType>(T1) && T1Quals) 1944 T1 = Context.getQualifiedType(UnqualT1, T1Quals); 1945 if (isa<ArrayType>(T2) && T2Quals) 1946 T2 = Context.getQualifiedType(UnqualT2, T2Quals); 1947 1948 ImplicitConversionSequence::CompareKind Result 1949 = ImplicitConversionSequence::Indistinguishable; 1950 while (UnwrapSimilarPointerTypes(T1, T2)) { 1951 // Within each iteration of the loop, we check the qualifiers to 1952 // determine if this still looks like a qualification 1953 // conversion. Then, if all is well, we unwrap one more level of 1954 // pointers or pointers-to-members and do it all again 1955 // until there are no more pointers or pointers-to-members left 1956 // to unwrap. This essentially mimics what 1957 // IsQualificationConversion does, but here we're checking for a 1958 // strict subset of qualifiers. 1959 if (T1.getCVRQualifiers() == T2.getCVRQualifiers()) 1960 // The qualifiers are the same, so this doesn't tell us anything 1961 // about how the sequences rank. 1962 ; 1963 else if (T2.isMoreQualifiedThan(T1)) { 1964 // T1 has fewer qualifiers, so it could be the better sequence. 1965 if (Result == ImplicitConversionSequence::Worse) 1966 // Neither has qualifiers that are a subset of the other's 1967 // qualifiers. 1968 return ImplicitConversionSequence::Indistinguishable; 1969 1970 Result = ImplicitConversionSequence::Better; 1971 } else if (T1.isMoreQualifiedThan(T2)) { 1972 // T2 has fewer qualifiers, so it could be the better sequence. 1973 if (Result == ImplicitConversionSequence::Better) 1974 // Neither has qualifiers that are a subset of the other's 1975 // qualifiers. 1976 return ImplicitConversionSequence::Indistinguishable; 1977 1978 Result = ImplicitConversionSequence::Worse; 1979 } else { 1980 // Qualifiers are disjoint. 1981 return ImplicitConversionSequence::Indistinguishable; 1982 } 1983 1984 // If the types after this point are equivalent, we're done. 1985 if (Context.hasSameUnqualifiedType(T1, T2)) 1986 break; 1987 } 1988 1989 // Check that the winning standard conversion sequence isn't using 1990 // the deprecated string literal array to pointer conversion. 1991 switch (Result) { 1992 case ImplicitConversionSequence::Better: 1993 if (SCS1.Deprecated) 1994 Result = ImplicitConversionSequence::Indistinguishable; 1995 break; 1996 1997 case ImplicitConversionSequence::Indistinguishable: 1998 break; 1999 2000 case ImplicitConversionSequence::Worse: 2001 if (SCS2.Deprecated) 2002 Result = ImplicitConversionSequence::Indistinguishable; 2003 break; 2004 } 2005 2006 return Result; 2007} 2008 2009/// CompareDerivedToBaseConversions - Compares two standard conversion 2010/// sequences to determine whether they can be ranked based on their 2011/// various kinds of derived-to-base conversions (C++ 2012/// [over.ics.rank]p4b3). As part of these checks, we also look at 2013/// conversions between Objective-C interface types. 2014ImplicitConversionSequence::CompareKind 2015Sema::CompareDerivedToBaseConversions(const StandardConversionSequence& SCS1, 2016 const StandardConversionSequence& SCS2) { 2017 QualType FromType1 = SCS1.getFromType(); 2018 QualType ToType1 = SCS1.getToType(1); 2019 QualType FromType2 = SCS2.getFromType(); 2020 QualType ToType2 = SCS2.getToType(1); 2021 2022 // Adjust the types we're converting from via the array-to-pointer 2023 // conversion, if we need to. 2024 if (SCS1.First == ICK_Array_To_Pointer) 2025 FromType1 = Context.getArrayDecayedType(FromType1); 2026 if (SCS2.First == ICK_Array_To_Pointer) 2027 FromType2 = Context.getArrayDecayedType(FromType2); 2028 2029 // Canonicalize all of the types. 2030 FromType1 = Context.getCanonicalType(FromType1); 2031 ToType1 = Context.getCanonicalType(ToType1); 2032 FromType2 = Context.getCanonicalType(FromType2); 2033 ToType2 = Context.getCanonicalType(ToType2); 2034 2035 // C++ [over.ics.rank]p4b3: 2036 // 2037 // If class B is derived directly or indirectly from class A and 2038 // class C is derived directly or indirectly from B, 2039 // 2040 // For Objective-C, we let A, B, and C also be Objective-C 2041 // interfaces. 2042 2043 // Compare based on pointer conversions. 2044 if (SCS1.Second == ICK_Pointer_Conversion && 2045 SCS2.Second == ICK_Pointer_Conversion && 2046 /*FIXME: Remove if Objective-C id conversions get their own rank*/ 2047 FromType1->isPointerType() && FromType2->isPointerType() && 2048 ToType1->isPointerType() && ToType2->isPointerType()) { 2049 QualType FromPointee1 2050 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2051 QualType ToPointee1 2052 = ToType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2053 QualType FromPointee2 2054 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2055 QualType ToPointee2 2056 = ToType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2057 2058 const ObjCInterfaceType* FromIface1 = FromPointee1->getAs<ObjCInterfaceType>(); 2059 const ObjCInterfaceType* FromIface2 = FromPointee2->getAs<ObjCInterfaceType>(); 2060 const ObjCInterfaceType* ToIface1 = ToPointee1->getAs<ObjCInterfaceType>(); 2061 const ObjCInterfaceType* ToIface2 = ToPointee2->getAs<ObjCInterfaceType>(); 2062 2063 // -- conversion of C* to B* is better than conversion of C* to A*, 2064 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 2065 if (IsDerivedFrom(ToPointee1, ToPointee2)) 2066 return ImplicitConversionSequence::Better; 2067 else if (IsDerivedFrom(ToPointee2, ToPointee1)) 2068 return ImplicitConversionSequence::Worse; 2069 2070 if (ToIface1 && ToIface2) { 2071 if (Context.canAssignObjCInterfaces(ToIface2, ToIface1)) 2072 return ImplicitConversionSequence::Better; 2073 else if (Context.canAssignObjCInterfaces(ToIface1, ToIface2)) 2074 return ImplicitConversionSequence::Worse; 2075 } 2076 } 2077 2078 // -- conversion of B* to A* is better than conversion of C* to A*, 2079 if (FromPointee1 != FromPointee2 && ToPointee1 == ToPointee2) { 2080 if (IsDerivedFrom(FromPointee2, FromPointee1)) 2081 return ImplicitConversionSequence::Better; 2082 else if (IsDerivedFrom(FromPointee1, FromPointee2)) 2083 return ImplicitConversionSequence::Worse; 2084 2085 if (FromIface1 && FromIface2) { 2086 if (Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 2087 return ImplicitConversionSequence::Better; 2088 else if (Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 2089 return ImplicitConversionSequence::Worse; 2090 } 2091 } 2092 } 2093 2094 // Compare based on reference bindings. 2095 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding && 2096 SCS1.Second == ICK_Derived_To_Base) { 2097 // -- binding of an expression of type C to a reference of type 2098 // B& is better than binding an expression of type C to a 2099 // reference of type A&, 2100 if (Context.hasSameUnqualifiedType(FromType1, FromType2) && 2101 !Context.hasSameUnqualifiedType(ToType1, ToType2)) { 2102 if (IsDerivedFrom(ToType1, ToType2)) 2103 return ImplicitConversionSequence::Better; 2104 else if (IsDerivedFrom(ToType2, ToType1)) 2105 return ImplicitConversionSequence::Worse; 2106 } 2107 2108 // -- binding of an expression of type B to a reference of type 2109 // A& is better than binding an expression of type C to a 2110 // reference of type A&, 2111 if (!Context.hasSameUnqualifiedType(FromType1, FromType2) && 2112 Context.hasSameUnqualifiedType(ToType1, ToType2)) { 2113 if (IsDerivedFrom(FromType2, FromType1)) 2114 return ImplicitConversionSequence::Better; 2115 else if (IsDerivedFrom(FromType1, FromType2)) 2116 return ImplicitConversionSequence::Worse; 2117 } 2118 } 2119 2120 // Ranking of member-pointer types. 2121 if (SCS1.Second == ICK_Pointer_Member && SCS2.Second == ICK_Pointer_Member && 2122 FromType1->isMemberPointerType() && FromType2->isMemberPointerType() && 2123 ToType1->isMemberPointerType() && ToType2->isMemberPointerType()) { 2124 const MemberPointerType * FromMemPointer1 = 2125 FromType1->getAs<MemberPointerType>(); 2126 const MemberPointerType * ToMemPointer1 = 2127 ToType1->getAs<MemberPointerType>(); 2128 const MemberPointerType * FromMemPointer2 = 2129 FromType2->getAs<MemberPointerType>(); 2130 const MemberPointerType * ToMemPointer2 = 2131 ToType2->getAs<MemberPointerType>(); 2132 const Type *FromPointeeType1 = FromMemPointer1->getClass(); 2133 const Type *ToPointeeType1 = ToMemPointer1->getClass(); 2134 const Type *FromPointeeType2 = FromMemPointer2->getClass(); 2135 const Type *ToPointeeType2 = ToMemPointer2->getClass(); 2136 QualType FromPointee1 = QualType(FromPointeeType1, 0).getUnqualifiedType(); 2137 QualType ToPointee1 = QualType(ToPointeeType1, 0).getUnqualifiedType(); 2138 QualType FromPointee2 = QualType(FromPointeeType2, 0).getUnqualifiedType(); 2139 QualType ToPointee2 = QualType(ToPointeeType2, 0).getUnqualifiedType(); 2140 // conversion of A::* to B::* is better than conversion of A::* to C::*, 2141 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 2142 if (IsDerivedFrom(ToPointee1, ToPointee2)) 2143 return ImplicitConversionSequence::Worse; 2144 else if (IsDerivedFrom(ToPointee2, ToPointee1)) 2145 return ImplicitConversionSequence::Better; 2146 } 2147 // conversion of B::* to C::* is better than conversion of A::* to C::* 2148 if (ToPointee1 == ToPointee2 && FromPointee1 != FromPointee2) { 2149 if (IsDerivedFrom(FromPointee1, FromPointee2)) 2150 return ImplicitConversionSequence::Better; 2151 else if (IsDerivedFrom(FromPointee2, FromPointee1)) 2152 return ImplicitConversionSequence::Worse; 2153 } 2154 } 2155 2156 if (SCS1.CopyConstructor && SCS2.CopyConstructor && 2157 SCS1.Second == ICK_Derived_To_Base) { 2158 // -- conversion of C to B is better than conversion of C to A, 2159 if (Context.hasSameUnqualifiedType(FromType1, FromType2) && 2160 !Context.hasSameUnqualifiedType(ToType1, ToType2)) { 2161 if (IsDerivedFrom(ToType1, ToType2)) 2162 return ImplicitConversionSequence::Better; 2163 else if (IsDerivedFrom(ToType2, ToType1)) 2164 return ImplicitConversionSequence::Worse; 2165 } 2166 2167 // -- conversion of B to A is better than conversion of C to A. 2168 if (!Context.hasSameUnqualifiedType(FromType1, FromType2) && 2169 Context.hasSameUnqualifiedType(ToType1, ToType2)) { 2170 if (IsDerivedFrom(FromType2, FromType1)) 2171 return ImplicitConversionSequence::Better; 2172 else if (IsDerivedFrom(FromType1, FromType2)) 2173 return ImplicitConversionSequence::Worse; 2174 } 2175 } 2176 2177 return ImplicitConversionSequence::Indistinguishable; 2178} 2179 2180/// TryCopyInitialization - Try to copy-initialize a value of type 2181/// ToType from the expression From. Return the implicit conversion 2182/// sequence required to pass this argument, which may be a bad 2183/// conversion sequence (meaning that the argument cannot be passed to 2184/// a parameter of this type). If @p SuppressUserConversions, then we 2185/// do not permit any user-defined conversion sequences. If @p ForceRValue, 2186/// then we treat @p From as an rvalue, even if it is an lvalue. 2187ImplicitConversionSequence 2188Sema::TryCopyInitialization(Expr *From, QualType ToType, 2189 bool SuppressUserConversions, bool ForceRValue, 2190 bool InOverloadResolution) { 2191 if (ToType->isReferenceType()) { 2192 ImplicitConversionSequence ICS; 2193 ICS.Bad.init(BadConversionSequence::no_conversion, From, ToType); 2194 CheckReferenceInit(From, ToType, 2195 /*FIXME:*/From->getLocStart(), 2196 SuppressUserConversions, 2197 /*AllowExplicit=*/false, 2198 ForceRValue, 2199 &ICS); 2200 return ICS; 2201 } else { 2202 return TryImplicitConversion(From, ToType, 2203 SuppressUserConversions, 2204 /*AllowExplicit=*/false, 2205 ForceRValue, 2206 InOverloadResolution); 2207 } 2208} 2209 2210/// PerformCopyInitialization - Copy-initialize an object of type @p ToType with 2211/// the expression @p From. Returns true (and emits a diagnostic) if there was 2212/// an error, returns false if the initialization succeeded. Elidable should 2213/// be true when the copy may be elided (C++ 12.8p15). Overload resolution works 2214/// differently in C++0x for this case. 2215bool Sema::PerformCopyInitialization(Expr *&From, QualType ToType, 2216 AssignmentAction Action, bool Elidable) { 2217 if (!getLangOptions().CPlusPlus) { 2218 // In C, argument passing is the same as performing an assignment. 2219 QualType FromType = From->getType(); 2220 2221 AssignConvertType ConvTy = 2222 CheckSingleAssignmentConstraints(ToType, From); 2223 if (ConvTy != Compatible && 2224 CheckTransparentUnionArgumentConstraints(ToType, From) == Compatible) 2225 ConvTy = Compatible; 2226 2227 return DiagnoseAssignmentResult(ConvTy, From->getLocStart(), ToType, 2228 FromType, From, Action); 2229 } 2230 2231 if (ToType->isReferenceType()) 2232 return CheckReferenceInit(From, ToType, 2233 /*FIXME:*/From->getLocStart(), 2234 /*SuppressUserConversions=*/false, 2235 /*AllowExplicit=*/false, 2236 /*ForceRValue=*/false); 2237 2238 if (!PerformImplicitConversion(From, ToType, Action, 2239 /*AllowExplicit=*/false, Elidable)) 2240 return false; 2241 if (!DiagnoseMultipleUserDefinedConversion(From, ToType)) 2242 return Diag(From->getSourceRange().getBegin(), 2243 diag::err_typecheck_convert_incompatible) 2244 << ToType << From->getType() << Action << From->getSourceRange(); 2245 return true; 2246} 2247 2248/// TryObjectArgumentInitialization - Try to initialize the object 2249/// parameter of the given member function (@c Method) from the 2250/// expression @p From. 2251ImplicitConversionSequence 2252Sema::TryObjectArgumentInitialization(QualType OrigFromType, 2253 CXXMethodDecl *Method, 2254 CXXRecordDecl *ActingContext) { 2255 QualType ClassType = Context.getTypeDeclType(ActingContext); 2256 // [class.dtor]p2: A destructor can be invoked for a const, volatile or 2257 // const volatile object. 2258 unsigned Quals = isa<CXXDestructorDecl>(Method) ? 2259 Qualifiers::Const | Qualifiers::Volatile : Method->getTypeQualifiers(); 2260 QualType ImplicitParamType = Context.getCVRQualifiedType(ClassType, Quals); 2261 2262 // Set up the conversion sequence as a "bad" conversion, to allow us 2263 // to exit early. 2264 ImplicitConversionSequence ICS; 2265 ICS.Standard.setAsIdentityConversion(); 2266 ICS.setBad(); 2267 2268 // We need to have an object of class type. 2269 QualType FromType = OrigFromType; 2270 if (const PointerType *PT = FromType->getAs<PointerType>()) 2271 FromType = PT->getPointeeType(); 2272 2273 assert(FromType->isRecordType()); 2274 2275 // The implicit object parameter is has the type "reference to cv X", 2276 // where X is the class of which the function is a member 2277 // (C++ [over.match.funcs]p4). However, when finding an implicit 2278 // conversion sequence for the argument, we are not allowed to 2279 // create temporaries or perform user-defined conversions 2280 // (C++ [over.match.funcs]p5). We perform a simplified version of 2281 // reference binding here, that allows class rvalues to bind to 2282 // non-constant references. 2283 2284 // First check the qualifiers. We don't care about lvalue-vs-rvalue 2285 // with the implicit object parameter (C++ [over.match.funcs]p5). 2286 QualType FromTypeCanon = Context.getCanonicalType(FromType); 2287 if (ImplicitParamType.getCVRQualifiers() 2288 != FromTypeCanon.getLocalCVRQualifiers() && 2289 !ImplicitParamType.isAtLeastAsQualifiedAs(FromTypeCanon)) { 2290 ICS.Bad.init(BadConversionSequence::bad_qualifiers, 2291 OrigFromType, ImplicitParamType); 2292 return ICS; 2293 } 2294 2295 // Check that we have either the same type or a derived type. It 2296 // affects the conversion rank. 2297 QualType ClassTypeCanon = Context.getCanonicalType(ClassType); 2298 if (ClassTypeCanon == FromTypeCanon.getLocalUnqualifiedType()) 2299 ICS.Standard.Second = ICK_Identity; 2300 else if (IsDerivedFrom(FromType, ClassType)) 2301 ICS.Standard.Second = ICK_Derived_To_Base; 2302 else { 2303 ICS.Bad.init(BadConversionSequence::unrelated_class, FromType, ImplicitParamType); 2304 return ICS; 2305 } 2306 2307 // Success. Mark this as a reference binding. 2308 ICS.setStandard(); 2309 ICS.Standard.setFromType(FromType); 2310 ICS.Standard.setAllToTypes(ImplicitParamType); 2311 ICS.Standard.ReferenceBinding = true; 2312 ICS.Standard.DirectBinding = true; 2313 ICS.Standard.RRefBinding = false; 2314 return ICS; 2315} 2316 2317/// PerformObjectArgumentInitialization - Perform initialization of 2318/// the implicit object parameter for the given Method with the given 2319/// expression. 2320bool 2321Sema::PerformObjectArgumentInitialization(Expr *&From, CXXMethodDecl *Method) { 2322 QualType FromRecordType, DestType; 2323 QualType ImplicitParamRecordType = 2324 Method->getThisType(Context)->getAs<PointerType>()->getPointeeType(); 2325 2326 if (const PointerType *PT = From->getType()->getAs<PointerType>()) { 2327 FromRecordType = PT->getPointeeType(); 2328 DestType = Method->getThisType(Context); 2329 } else { 2330 FromRecordType = From->getType(); 2331 DestType = ImplicitParamRecordType; 2332 } 2333 2334 // Note that we always use the true parent context when performing 2335 // the actual argument initialization. 2336 ImplicitConversionSequence ICS 2337 = TryObjectArgumentInitialization(From->getType(), Method, 2338 Method->getParent()); 2339 if (ICS.isBad()) 2340 return Diag(From->getSourceRange().getBegin(), 2341 diag::err_implicit_object_parameter_init) 2342 << ImplicitParamRecordType << FromRecordType << From->getSourceRange(); 2343 2344 if (ICS.Standard.Second == ICK_Derived_To_Base && 2345 CheckDerivedToBaseConversion(FromRecordType, 2346 ImplicitParamRecordType, 2347 From->getSourceRange().getBegin(), 2348 From->getSourceRange())) 2349 return true; 2350 2351 ImpCastExprToType(From, DestType, CastExpr::CK_DerivedToBase, 2352 /*isLvalue=*/true); 2353 return false; 2354} 2355 2356/// TryContextuallyConvertToBool - Attempt to contextually convert the 2357/// expression From to bool (C++0x [conv]p3). 2358ImplicitConversionSequence Sema::TryContextuallyConvertToBool(Expr *From) { 2359 return TryImplicitConversion(From, Context.BoolTy, 2360 // FIXME: Are these flags correct? 2361 /*SuppressUserConversions=*/false, 2362 /*AllowExplicit=*/true, 2363 /*ForceRValue=*/false, 2364 /*InOverloadResolution=*/false); 2365} 2366 2367/// PerformContextuallyConvertToBool - Perform a contextual conversion 2368/// of the expression From to bool (C++0x [conv]p3). 2369bool Sema::PerformContextuallyConvertToBool(Expr *&From) { 2370 ImplicitConversionSequence ICS = TryContextuallyConvertToBool(From); 2371 if (!ICS.isBad()) 2372 return PerformImplicitConversion(From, Context.BoolTy, ICS, AA_Converting); 2373 2374 if (!DiagnoseMultipleUserDefinedConversion(From, Context.BoolTy)) 2375 return Diag(From->getSourceRange().getBegin(), 2376 diag::err_typecheck_bool_condition) 2377 << From->getType() << From->getSourceRange(); 2378 return true; 2379} 2380 2381/// AddOverloadCandidate - Adds the given function to the set of 2382/// candidate functions, using the given function call arguments. If 2383/// @p SuppressUserConversions, then don't allow user-defined 2384/// conversions via constructors or conversion operators. 2385/// If @p ForceRValue, treat all arguments as rvalues. This is a slightly 2386/// hacky way to implement the overloading rules for elidable copy 2387/// initialization in C++0x (C++0x 12.8p15). 2388/// 2389/// \para PartialOverloading true if we are performing "partial" overloading 2390/// based on an incomplete set of function arguments. This feature is used by 2391/// code completion. 2392void 2393Sema::AddOverloadCandidate(FunctionDecl *Function, 2394 AccessSpecifier Access, 2395 Expr **Args, unsigned NumArgs, 2396 OverloadCandidateSet& CandidateSet, 2397 bool SuppressUserConversions, 2398 bool ForceRValue, 2399 bool PartialOverloading) { 2400 const FunctionProtoType* Proto 2401 = dyn_cast<FunctionProtoType>(Function->getType()->getAs<FunctionType>()); 2402 assert(Proto && "Functions without a prototype cannot be overloaded"); 2403 assert(!Function->getDescribedFunctionTemplate() && 2404 "Use AddTemplateOverloadCandidate for function templates"); 2405 2406 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Function)) { 2407 if (!isa<CXXConstructorDecl>(Method)) { 2408 // If we get here, it's because we're calling a member function 2409 // that is named without a member access expression (e.g., 2410 // "this->f") that was either written explicitly or created 2411 // implicitly. This can happen with a qualified call to a member 2412 // function, e.g., X::f(). We use an empty type for the implied 2413 // object argument (C++ [over.call.func]p3), and the acting context 2414 // is irrelevant. 2415 AddMethodCandidate(Method, Access, Method->getParent(), 2416 QualType(), Args, NumArgs, CandidateSet, 2417 SuppressUserConversions, ForceRValue); 2418 return; 2419 } 2420 // We treat a constructor like a non-member function, since its object 2421 // argument doesn't participate in overload resolution. 2422 } 2423 2424 if (!CandidateSet.isNewCandidate(Function)) 2425 return; 2426 2427 // Overload resolution is always an unevaluated context. 2428 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 2429 2430 if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(Function)){ 2431 // C++ [class.copy]p3: 2432 // A member function template is never instantiated to perform the copy 2433 // of a class object to an object of its class type. 2434 QualType ClassType = Context.getTypeDeclType(Constructor->getParent()); 2435 if (NumArgs == 1 && 2436 Constructor->isCopyConstructorLikeSpecialization() && 2437 Context.hasSameUnqualifiedType(ClassType, Args[0]->getType())) 2438 return; 2439 } 2440 2441 // Add this candidate 2442 CandidateSet.push_back(OverloadCandidate()); 2443 OverloadCandidate& Candidate = CandidateSet.back(); 2444 Candidate.Function = Function; 2445 Candidate.Access = Access; 2446 Candidate.Viable = true; 2447 Candidate.IsSurrogate = false; 2448 Candidate.IgnoreObjectArgument = false; 2449 2450 unsigned NumArgsInProto = Proto->getNumArgs(); 2451 2452 // (C++ 13.3.2p2): A candidate function having fewer than m 2453 // parameters is viable only if it has an ellipsis in its parameter 2454 // list (8.3.5). 2455 if ((NumArgs + (PartialOverloading && NumArgs)) > NumArgsInProto && 2456 !Proto->isVariadic()) { 2457 Candidate.Viable = false; 2458 Candidate.FailureKind = ovl_fail_too_many_arguments; 2459 return; 2460 } 2461 2462 // (C++ 13.3.2p2): A candidate function having more than m parameters 2463 // is viable only if the (m+1)st parameter has a default argument 2464 // (8.3.6). For the purposes of overload resolution, the 2465 // parameter list is truncated on the right, so that there are 2466 // exactly m parameters. 2467 unsigned MinRequiredArgs = Function->getMinRequiredArguments(); 2468 if (NumArgs < MinRequiredArgs && !PartialOverloading) { 2469 // Not enough arguments. 2470 Candidate.Viable = false; 2471 Candidate.FailureKind = ovl_fail_too_few_arguments; 2472 return; 2473 } 2474 2475 // Determine the implicit conversion sequences for each of the 2476 // arguments. 2477 Candidate.Conversions.resize(NumArgs); 2478 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2479 if (ArgIdx < NumArgsInProto) { 2480 // (C++ 13.3.2p3): for F to be a viable function, there shall 2481 // exist for each argument an implicit conversion sequence 2482 // (13.3.3.1) that converts that argument to the corresponding 2483 // parameter of F. 2484 QualType ParamType = Proto->getArgType(ArgIdx); 2485 Candidate.Conversions[ArgIdx] 2486 = TryCopyInitialization(Args[ArgIdx], ParamType, 2487 SuppressUserConversions, ForceRValue, 2488 /*InOverloadResolution=*/true); 2489 if (Candidate.Conversions[ArgIdx].isBad()) { 2490 Candidate.Viable = false; 2491 Candidate.FailureKind = ovl_fail_bad_conversion; 2492 break; 2493 } 2494 } else { 2495 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2496 // argument for which there is no corresponding parameter is 2497 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2498 Candidate.Conversions[ArgIdx].setEllipsis(); 2499 } 2500 } 2501} 2502 2503/// \brief Add all of the function declarations in the given function set to 2504/// the overload canddiate set. 2505void Sema::AddFunctionCandidates(const UnresolvedSetImpl &Fns, 2506 Expr **Args, unsigned NumArgs, 2507 OverloadCandidateSet& CandidateSet, 2508 bool SuppressUserConversions) { 2509 for (UnresolvedSetIterator F = Fns.begin(), E = Fns.end(); F != E; ++F) { 2510 // FIXME: using declarations 2511 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*F)) { 2512 if (isa<CXXMethodDecl>(FD) && !cast<CXXMethodDecl>(FD)->isStatic()) 2513 AddMethodCandidate(cast<CXXMethodDecl>(FD), F.getAccess(), 2514 cast<CXXMethodDecl>(FD)->getParent(), 2515 Args[0]->getType(), Args + 1, NumArgs - 1, 2516 CandidateSet, SuppressUserConversions); 2517 else 2518 AddOverloadCandidate(FD, AS_none, Args, NumArgs, CandidateSet, 2519 SuppressUserConversions); 2520 } else { 2521 FunctionTemplateDecl *FunTmpl = cast<FunctionTemplateDecl>(*F); 2522 if (isa<CXXMethodDecl>(FunTmpl->getTemplatedDecl()) && 2523 !cast<CXXMethodDecl>(FunTmpl->getTemplatedDecl())->isStatic()) 2524 AddMethodTemplateCandidate(FunTmpl, F.getAccess(), 2525 cast<CXXRecordDecl>(FunTmpl->getDeclContext()), 2526 /*FIXME: explicit args */ 0, 2527 Args[0]->getType(), Args + 1, NumArgs - 1, 2528 CandidateSet, 2529 SuppressUserConversions); 2530 else 2531 AddTemplateOverloadCandidate(FunTmpl, AS_none, 2532 /*FIXME: explicit args */ 0, 2533 Args, NumArgs, CandidateSet, 2534 SuppressUserConversions); 2535 } 2536 } 2537} 2538 2539/// AddMethodCandidate - Adds a named decl (which is some kind of 2540/// method) as a method candidate to the given overload set. 2541void Sema::AddMethodCandidate(NamedDecl *Decl, 2542 AccessSpecifier Access, 2543 QualType ObjectType, 2544 Expr **Args, unsigned NumArgs, 2545 OverloadCandidateSet& CandidateSet, 2546 bool SuppressUserConversions, bool ForceRValue) { 2547 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(Decl->getDeclContext()); 2548 2549 if (isa<UsingShadowDecl>(Decl)) 2550 Decl = cast<UsingShadowDecl>(Decl)->getTargetDecl(); 2551 2552 if (FunctionTemplateDecl *TD = dyn_cast<FunctionTemplateDecl>(Decl)) { 2553 assert(isa<CXXMethodDecl>(TD->getTemplatedDecl()) && 2554 "Expected a member function template"); 2555 AddMethodTemplateCandidate(TD, Access, ActingContext, /*ExplicitArgs*/ 0, 2556 ObjectType, Args, NumArgs, 2557 CandidateSet, 2558 SuppressUserConversions, 2559 ForceRValue); 2560 } else { 2561 AddMethodCandidate(cast<CXXMethodDecl>(Decl), Access, ActingContext, 2562 ObjectType, Args, NumArgs, 2563 CandidateSet, SuppressUserConversions, ForceRValue); 2564 } 2565} 2566 2567/// AddMethodCandidate - Adds the given C++ member function to the set 2568/// of candidate functions, using the given function call arguments 2569/// and the object argument (@c Object). For example, in a call 2570/// @c o.f(a1,a2), @c Object will contain @c o and @c Args will contain 2571/// both @c a1 and @c a2. If @p SuppressUserConversions, then don't 2572/// allow user-defined conversions via constructors or conversion 2573/// operators. If @p ForceRValue, treat all arguments as rvalues. This is 2574/// a slightly hacky way to implement the overloading rules for elidable copy 2575/// initialization in C++0x (C++0x 12.8p15). 2576void 2577Sema::AddMethodCandidate(CXXMethodDecl *Method, AccessSpecifier Access, 2578 CXXRecordDecl *ActingContext, QualType ObjectType, 2579 Expr **Args, unsigned NumArgs, 2580 OverloadCandidateSet& CandidateSet, 2581 bool SuppressUserConversions, bool ForceRValue) { 2582 const FunctionProtoType* Proto 2583 = dyn_cast<FunctionProtoType>(Method->getType()->getAs<FunctionType>()); 2584 assert(Proto && "Methods without a prototype cannot be overloaded"); 2585 assert(!isa<CXXConstructorDecl>(Method) && 2586 "Use AddOverloadCandidate for constructors"); 2587 2588 if (!CandidateSet.isNewCandidate(Method)) 2589 return; 2590 2591 // Overload resolution is always an unevaluated context. 2592 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 2593 2594 // Add this candidate 2595 CandidateSet.push_back(OverloadCandidate()); 2596 OverloadCandidate& Candidate = CandidateSet.back(); 2597 Candidate.Function = Method; 2598 Candidate.Access = Access; 2599 Candidate.IsSurrogate = false; 2600 Candidate.IgnoreObjectArgument = false; 2601 2602 unsigned NumArgsInProto = Proto->getNumArgs(); 2603 2604 // (C++ 13.3.2p2): A candidate function having fewer than m 2605 // parameters is viable only if it has an ellipsis in its parameter 2606 // list (8.3.5). 2607 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 2608 Candidate.Viable = false; 2609 Candidate.FailureKind = ovl_fail_too_many_arguments; 2610 return; 2611 } 2612 2613 // (C++ 13.3.2p2): A candidate function having more than m parameters 2614 // is viable only if the (m+1)st parameter has a default argument 2615 // (8.3.6). For the purposes of overload resolution, the 2616 // parameter list is truncated on the right, so that there are 2617 // exactly m parameters. 2618 unsigned MinRequiredArgs = Method->getMinRequiredArguments(); 2619 if (NumArgs < MinRequiredArgs) { 2620 // Not enough arguments. 2621 Candidate.Viable = false; 2622 Candidate.FailureKind = ovl_fail_too_few_arguments; 2623 return; 2624 } 2625 2626 Candidate.Viable = true; 2627 Candidate.Conversions.resize(NumArgs + 1); 2628 2629 if (Method->isStatic() || ObjectType.isNull()) 2630 // The implicit object argument is ignored. 2631 Candidate.IgnoreObjectArgument = true; 2632 else { 2633 // Determine the implicit conversion sequence for the object 2634 // parameter. 2635 Candidate.Conversions[0] 2636 = TryObjectArgumentInitialization(ObjectType, Method, ActingContext); 2637 if (Candidate.Conversions[0].isBad()) { 2638 Candidate.Viable = false; 2639 Candidate.FailureKind = ovl_fail_bad_conversion; 2640 return; 2641 } 2642 } 2643 2644 // Determine the implicit conversion sequences for each of the 2645 // arguments. 2646 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2647 if (ArgIdx < NumArgsInProto) { 2648 // (C++ 13.3.2p3): for F to be a viable function, there shall 2649 // exist for each argument an implicit conversion sequence 2650 // (13.3.3.1) that converts that argument to the corresponding 2651 // parameter of F. 2652 QualType ParamType = Proto->getArgType(ArgIdx); 2653 Candidate.Conversions[ArgIdx + 1] 2654 = TryCopyInitialization(Args[ArgIdx], ParamType, 2655 SuppressUserConversions, ForceRValue, 2656 /*InOverloadResolution=*/true); 2657 if (Candidate.Conversions[ArgIdx + 1].isBad()) { 2658 Candidate.Viable = false; 2659 Candidate.FailureKind = ovl_fail_bad_conversion; 2660 break; 2661 } 2662 } else { 2663 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2664 // argument for which there is no corresponding parameter is 2665 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2666 Candidate.Conversions[ArgIdx + 1].setEllipsis(); 2667 } 2668 } 2669} 2670 2671/// \brief Add a C++ member function template as a candidate to the candidate 2672/// set, using template argument deduction to produce an appropriate member 2673/// function template specialization. 2674void 2675Sema::AddMethodTemplateCandidate(FunctionTemplateDecl *MethodTmpl, 2676 AccessSpecifier Access, 2677 CXXRecordDecl *ActingContext, 2678 const TemplateArgumentListInfo *ExplicitTemplateArgs, 2679 QualType ObjectType, 2680 Expr **Args, unsigned NumArgs, 2681 OverloadCandidateSet& CandidateSet, 2682 bool SuppressUserConversions, 2683 bool ForceRValue) { 2684 if (!CandidateSet.isNewCandidate(MethodTmpl)) 2685 return; 2686 2687 // C++ [over.match.funcs]p7: 2688 // In each case where a candidate is a function template, candidate 2689 // function template specializations are generated using template argument 2690 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 2691 // candidate functions in the usual way.113) A given name can refer to one 2692 // or more function templates and also to a set of overloaded non-template 2693 // functions. In such a case, the candidate functions generated from each 2694 // function template are combined with the set of non-template candidate 2695 // functions. 2696 TemplateDeductionInfo Info(Context); 2697 FunctionDecl *Specialization = 0; 2698 if (TemplateDeductionResult Result 2699 = DeduceTemplateArguments(MethodTmpl, ExplicitTemplateArgs, 2700 Args, NumArgs, Specialization, Info)) { 2701 // FIXME: Record what happened with template argument deduction, so 2702 // that we can give the user a beautiful diagnostic. 2703 (void)Result; 2704 return; 2705 } 2706 2707 // Add the function template specialization produced by template argument 2708 // deduction as a candidate. 2709 assert(Specialization && "Missing member function template specialization?"); 2710 assert(isa<CXXMethodDecl>(Specialization) && 2711 "Specialization is not a member function?"); 2712 AddMethodCandidate(cast<CXXMethodDecl>(Specialization), Access, 2713 ActingContext, ObjectType, Args, NumArgs, 2714 CandidateSet, SuppressUserConversions, ForceRValue); 2715} 2716 2717/// \brief Add a C++ function template specialization as a candidate 2718/// in the candidate set, using template argument deduction to produce 2719/// an appropriate function template specialization. 2720void 2721Sema::AddTemplateOverloadCandidate(FunctionTemplateDecl *FunctionTemplate, 2722 AccessSpecifier Access, 2723 const TemplateArgumentListInfo *ExplicitTemplateArgs, 2724 Expr **Args, unsigned NumArgs, 2725 OverloadCandidateSet& CandidateSet, 2726 bool SuppressUserConversions, 2727 bool ForceRValue) { 2728 if (!CandidateSet.isNewCandidate(FunctionTemplate)) 2729 return; 2730 2731 // C++ [over.match.funcs]p7: 2732 // In each case where a candidate is a function template, candidate 2733 // function template specializations are generated using template argument 2734 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 2735 // candidate functions in the usual way.113) A given name can refer to one 2736 // or more function templates and also to a set of overloaded non-template 2737 // functions. In such a case, the candidate functions generated from each 2738 // function template are combined with the set of non-template candidate 2739 // functions. 2740 TemplateDeductionInfo Info(Context); 2741 FunctionDecl *Specialization = 0; 2742 if (TemplateDeductionResult Result 2743 = DeduceTemplateArguments(FunctionTemplate, ExplicitTemplateArgs, 2744 Args, NumArgs, Specialization, Info)) { 2745 CandidateSet.push_back(OverloadCandidate()); 2746 OverloadCandidate &Candidate = CandidateSet.back(); 2747 Candidate.Function = FunctionTemplate->getTemplatedDecl(); 2748 Candidate.Access = Access; 2749 Candidate.Viable = false; 2750 Candidate.FailureKind = ovl_fail_bad_deduction; 2751 Candidate.IsSurrogate = false; 2752 Candidate.IgnoreObjectArgument = false; 2753 2754 // TODO: record more information about failed template arguments 2755 Candidate.DeductionFailure.Result = Result; 2756 Candidate.DeductionFailure.TemplateParameter = Info.Param.getOpaqueValue(); 2757 return; 2758 } 2759 2760 // Add the function template specialization produced by template argument 2761 // deduction as a candidate. 2762 assert(Specialization && "Missing function template specialization?"); 2763 AddOverloadCandidate(Specialization, Access, Args, NumArgs, CandidateSet, 2764 SuppressUserConversions, ForceRValue); 2765} 2766 2767/// AddConversionCandidate - Add a C++ conversion function as a 2768/// candidate in the candidate set (C++ [over.match.conv], 2769/// C++ [over.match.copy]). From is the expression we're converting from, 2770/// and ToType is the type that we're eventually trying to convert to 2771/// (which may or may not be the same type as the type that the 2772/// conversion function produces). 2773void 2774Sema::AddConversionCandidate(CXXConversionDecl *Conversion, 2775 AccessSpecifier Access, 2776 CXXRecordDecl *ActingContext, 2777 Expr *From, QualType ToType, 2778 OverloadCandidateSet& CandidateSet) { 2779 assert(!Conversion->getDescribedFunctionTemplate() && 2780 "Conversion function templates use AddTemplateConversionCandidate"); 2781 2782 if (!CandidateSet.isNewCandidate(Conversion)) 2783 return; 2784 2785 // Overload resolution is always an unevaluated context. 2786 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 2787 2788 // Add this candidate 2789 CandidateSet.push_back(OverloadCandidate()); 2790 OverloadCandidate& Candidate = CandidateSet.back(); 2791 Candidate.Function = Conversion; 2792 Candidate.Access = Access; 2793 Candidate.IsSurrogate = false; 2794 Candidate.IgnoreObjectArgument = false; 2795 Candidate.FinalConversion.setAsIdentityConversion(); 2796 Candidate.FinalConversion.setFromType(Conversion->getConversionType()); 2797 Candidate.FinalConversion.setAllToTypes(ToType); 2798 2799 // Determine the implicit conversion sequence for the implicit 2800 // object parameter. 2801 Candidate.Viable = true; 2802 Candidate.Conversions.resize(1); 2803 Candidate.Conversions[0] 2804 = TryObjectArgumentInitialization(From->getType(), Conversion, 2805 ActingContext); 2806 // Conversion functions to a different type in the base class is visible in 2807 // the derived class. So, a derived to base conversion should not participate 2808 // in overload resolution. 2809 if (Candidate.Conversions[0].Standard.Second == ICK_Derived_To_Base) 2810 Candidate.Conversions[0].Standard.Second = ICK_Identity; 2811 if (Candidate.Conversions[0].isBad()) { 2812 Candidate.Viable = false; 2813 Candidate.FailureKind = ovl_fail_bad_conversion; 2814 return; 2815 } 2816 2817 // We won't go through a user-define type conversion function to convert a 2818 // derived to base as such conversions are given Conversion Rank. They only 2819 // go through a copy constructor. 13.3.3.1.2-p4 [over.ics.user] 2820 QualType FromCanon 2821 = Context.getCanonicalType(From->getType().getUnqualifiedType()); 2822 QualType ToCanon = Context.getCanonicalType(ToType).getUnqualifiedType(); 2823 if (FromCanon == ToCanon || IsDerivedFrom(FromCanon, ToCanon)) { 2824 Candidate.Viable = false; 2825 Candidate.FailureKind = ovl_fail_trivial_conversion; 2826 return; 2827 } 2828 2829 2830 // To determine what the conversion from the result of calling the 2831 // conversion function to the type we're eventually trying to 2832 // convert to (ToType), we need to synthesize a call to the 2833 // conversion function and attempt copy initialization from it. This 2834 // makes sure that we get the right semantics with respect to 2835 // lvalues/rvalues and the type. Fortunately, we can allocate this 2836 // call on the stack and we don't need its arguments to be 2837 // well-formed. 2838 DeclRefExpr ConversionRef(Conversion, Conversion->getType(), 2839 From->getLocStart()); 2840 ImplicitCastExpr ConversionFn(Context.getPointerType(Conversion->getType()), 2841 CastExpr::CK_FunctionToPointerDecay, 2842 &ConversionRef, false); 2843 2844 // Note that it is safe to allocate CallExpr on the stack here because 2845 // there are 0 arguments (i.e., nothing is allocated using ASTContext's 2846 // allocator). 2847 CallExpr Call(Context, &ConversionFn, 0, 0, 2848 Conversion->getConversionType().getNonReferenceType(), 2849 From->getLocStart()); 2850 ImplicitConversionSequence ICS = 2851 TryCopyInitialization(&Call, ToType, 2852 /*SuppressUserConversions=*/true, 2853 /*ForceRValue=*/false, 2854 /*InOverloadResolution=*/false); 2855 2856 switch (ICS.getKind()) { 2857 case ImplicitConversionSequence::StandardConversion: 2858 Candidate.FinalConversion = ICS.Standard; 2859 break; 2860 2861 case ImplicitConversionSequence::BadConversion: 2862 Candidate.Viable = false; 2863 Candidate.FailureKind = ovl_fail_bad_final_conversion; 2864 break; 2865 2866 default: 2867 assert(false && 2868 "Can only end up with a standard conversion sequence or failure"); 2869 } 2870} 2871 2872/// \brief Adds a conversion function template specialization 2873/// candidate to the overload set, using template argument deduction 2874/// to deduce the template arguments of the conversion function 2875/// template from the type that we are converting to (C++ 2876/// [temp.deduct.conv]). 2877void 2878Sema::AddTemplateConversionCandidate(FunctionTemplateDecl *FunctionTemplate, 2879 AccessSpecifier Access, 2880 CXXRecordDecl *ActingDC, 2881 Expr *From, QualType ToType, 2882 OverloadCandidateSet &CandidateSet) { 2883 assert(isa<CXXConversionDecl>(FunctionTemplate->getTemplatedDecl()) && 2884 "Only conversion function templates permitted here"); 2885 2886 if (!CandidateSet.isNewCandidate(FunctionTemplate)) 2887 return; 2888 2889 TemplateDeductionInfo Info(Context); 2890 CXXConversionDecl *Specialization = 0; 2891 if (TemplateDeductionResult Result 2892 = DeduceTemplateArguments(FunctionTemplate, ToType, 2893 Specialization, Info)) { 2894 // FIXME: Record what happened with template argument deduction, so 2895 // that we can give the user a beautiful diagnostic. 2896 (void)Result; 2897 return; 2898 } 2899 2900 // Add the conversion function template specialization produced by 2901 // template argument deduction as a candidate. 2902 assert(Specialization && "Missing function template specialization?"); 2903 AddConversionCandidate(Specialization, Access, ActingDC, From, ToType, 2904 CandidateSet); 2905} 2906 2907/// AddSurrogateCandidate - Adds a "surrogate" candidate function that 2908/// converts the given @c Object to a function pointer via the 2909/// conversion function @c Conversion, and then attempts to call it 2910/// with the given arguments (C++ [over.call.object]p2-4). Proto is 2911/// the type of function that we'll eventually be calling. 2912void Sema::AddSurrogateCandidate(CXXConversionDecl *Conversion, 2913 AccessSpecifier Access, 2914 CXXRecordDecl *ActingContext, 2915 const FunctionProtoType *Proto, 2916 QualType ObjectType, 2917 Expr **Args, unsigned NumArgs, 2918 OverloadCandidateSet& CandidateSet) { 2919 if (!CandidateSet.isNewCandidate(Conversion)) 2920 return; 2921 2922 // Overload resolution is always an unevaluated context. 2923 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 2924 2925 CandidateSet.push_back(OverloadCandidate()); 2926 OverloadCandidate& Candidate = CandidateSet.back(); 2927 Candidate.Function = 0; 2928 Candidate.Access = Access; 2929 Candidate.Surrogate = Conversion; 2930 Candidate.Viable = true; 2931 Candidate.IsSurrogate = true; 2932 Candidate.IgnoreObjectArgument = false; 2933 Candidate.Conversions.resize(NumArgs + 1); 2934 2935 // Determine the implicit conversion sequence for the implicit 2936 // object parameter. 2937 ImplicitConversionSequence ObjectInit 2938 = TryObjectArgumentInitialization(ObjectType, Conversion, ActingContext); 2939 if (ObjectInit.isBad()) { 2940 Candidate.Viable = false; 2941 Candidate.FailureKind = ovl_fail_bad_conversion; 2942 Candidate.Conversions[0] = ObjectInit; 2943 return; 2944 } 2945 2946 // The first conversion is actually a user-defined conversion whose 2947 // first conversion is ObjectInit's standard conversion (which is 2948 // effectively a reference binding). Record it as such. 2949 Candidate.Conversions[0].setUserDefined(); 2950 Candidate.Conversions[0].UserDefined.Before = ObjectInit.Standard; 2951 Candidate.Conversions[0].UserDefined.EllipsisConversion = false; 2952 Candidate.Conversions[0].UserDefined.ConversionFunction = Conversion; 2953 Candidate.Conversions[0].UserDefined.After 2954 = Candidate.Conversions[0].UserDefined.Before; 2955 Candidate.Conversions[0].UserDefined.After.setAsIdentityConversion(); 2956 2957 // Find the 2958 unsigned NumArgsInProto = Proto->getNumArgs(); 2959 2960 // (C++ 13.3.2p2): A candidate function having fewer than m 2961 // parameters is viable only if it has an ellipsis in its parameter 2962 // list (8.3.5). 2963 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 2964 Candidate.Viable = false; 2965 Candidate.FailureKind = ovl_fail_too_many_arguments; 2966 return; 2967 } 2968 2969 // Function types don't have any default arguments, so just check if 2970 // we have enough arguments. 2971 if (NumArgs < NumArgsInProto) { 2972 // Not enough arguments. 2973 Candidate.Viable = false; 2974 Candidate.FailureKind = ovl_fail_too_few_arguments; 2975 return; 2976 } 2977 2978 // Determine the implicit conversion sequences for each of the 2979 // arguments. 2980 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2981 if (ArgIdx < NumArgsInProto) { 2982 // (C++ 13.3.2p3): for F to be a viable function, there shall 2983 // exist for each argument an implicit conversion sequence 2984 // (13.3.3.1) that converts that argument to the corresponding 2985 // parameter of F. 2986 QualType ParamType = Proto->getArgType(ArgIdx); 2987 Candidate.Conversions[ArgIdx + 1] 2988 = TryCopyInitialization(Args[ArgIdx], ParamType, 2989 /*SuppressUserConversions=*/false, 2990 /*ForceRValue=*/false, 2991 /*InOverloadResolution=*/false); 2992 if (Candidate.Conversions[ArgIdx + 1].isBad()) { 2993 Candidate.Viable = false; 2994 Candidate.FailureKind = ovl_fail_bad_conversion; 2995 break; 2996 } 2997 } else { 2998 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2999 // argument for which there is no corresponding parameter is 3000 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 3001 Candidate.Conversions[ArgIdx + 1].setEllipsis(); 3002 } 3003 } 3004} 3005 3006// FIXME: This will eventually be removed, once we've migrated all of the 3007// operator overloading logic over to the scheme used by binary operators, which 3008// works for template instantiation. 3009void Sema::AddOperatorCandidates(OverloadedOperatorKind Op, Scope *S, 3010 SourceLocation OpLoc, 3011 Expr **Args, unsigned NumArgs, 3012 OverloadCandidateSet& CandidateSet, 3013 SourceRange OpRange) { 3014 UnresolvedSet<16> Fns; 3015 3016 QualType T1 = Args[0]->getType(); 3017 QualType T2; 3018 if (NumArgs > 1) 3019 T2 = Args[1]->getType(); 3020 3021 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 3022 if (S) 3023 LookupOverloadedOperatorName(Op, S, T1, T2, Fns); 3024 AddFunctionCandidates(Fns, Args, NumArgs, CandidateSet, false); 3025 AddArgumentDependentLookupCandidates(OpName, false, Args, NumArgs, 0, 3026 CandidateSet); 3027 AddMemberOperatorCandidates(Op, OpLoc, Args, NumArgs, CandidateSet, OpRange); 3028 AddBuiltinOperatorCandidates(Op, OpLoc, Args, NumArgs, CandidateSet); 3029} 3030 3031/// \brief Add overload candidates for overloaded operators that are 3032/// member functions. 3033/// 3034/// Add the overloaded operator candidates that are member functions 3035/// for the operator Op that was used in an operator expression such 3036/// as "x Op y". , Args/NumArgs provides the operator arguments, and 3037/// CandidateSet will store the added overload candidates. (C++ 3038/// [over.match.oper]). 3039void Sema::AddMemberOperatorCandidates(OverloadedOperatorKind Op, 3040 SourceLocation OpLoc, 3041 Expr **Args, unsigned NumArgs, 3042 OverloadCandidateSet& CandidateSet, 3043 SourceRange OpRange) { 3044 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 3045 3046 // C++ [over.match.oper]p3: 3047 // For a unary operator @ with an operand of a type whose 3048 // cv-unqualified version is T1, and for a binary operator @ with 3049 // a left operand of a type whose cv-unqualified version is T1 and 3050 // a right operand of a type whose cv-unqualified version is T2, 3051 // three sets of candidate functions, designated member 3052 // candidates, non-member candidates and built-in candidates, are 3053 // constructed as follows: 3054 QualType T1 = Args[0]->getType(); 3055 QualType T2; 3056 if (NumArgs > 1) 3057 T2 = Args[1]->getType(); 3058 3059 // -- If T1 is a class type, the set of member candidates is the 3060 // result of the qualified lookup of T1::operator@ 3061 // (13.3.1.1.1); otherwise, the set of member candidates is 3062 // empty. 3063 if (const RecordType *T1Rec = T1->getAs<RecordType>()) { 3064 // Complete the type if it can be completed. Otherwise, we're done. 3065 if (RequireCompleteType(OpLoc, T1, PDiag())) 3066 return; 3067 3068 LookupResult Operators(*this, OpName, OpLoc, LookupOrdinaryName); 3069 LookupQualifiedName(Operators, T1Rec->getDecl()); 3070 Operators.suppressDiagnostics(); 3071 3072 for (LookupResult::iterator Oper = Operators.begin(), 3073 OperEnd = Operators.end(); 3074 Oper != OperEnd; 3075 ++Oper) 3076 AddMethodCandidate(*Oper, Oper.getAccess(), Args[0]->getType(), 3077 Args + 1, NumArgs - 1, CandidateSet, 3078 /* SuppressUserConversions = */ false); 3079 } 3080} 3081 3082/// AddBuiltinCandidate - Add a candidate for a built-in 3083/// operator. ResultTy and ParamTys are the result and parameter types 3084/// of the built-in candidate, respectively. Args and NumArgs are the 3085/// arguments being passed to the candidate. IsAssignmentOperator 3086/// should be true when this built-in candidate is an assignment 3087/// operator. NumContextualBoolArguments is the number of arguments 3088/// (at the beginning of the argument list) that will be contextually 3089/// converted to bool. 3090void Sema::AddBuiltinCandidate(QualType ResultTy, QualType *ParamTys, 3091 Expr **Args, unsigned NumArgs, 3092 OverloadCandidateSet& CandidateSet, 3093 bool IsAssignmentOperator, 3094 unsigned NumContextualBoolArguments) { 3095 // Overload resolution is always an unevaluated context. 3096 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 3097 3098 // Add this candidate 3099 CandidateSet.push_back(OverloadCandidate()); 3100 OverloadCandidate& Candidate = CandidateSet.back(); 3101 Candidate.Function = 0; 3102 Candidate.Access = AS_none; 3103 Candidate.IsSurrogate = false; 3104 Candidate.IgnoreObjectArgument = false; 3105 Candidate.BuiltinTypes.ResultTy = ResultTy; 3106 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 3107 Candidate.BuiltinTypes.ParamTypes[ArgIdx] = ParamTys[ArgIdx]; 3108 3109 // Determine the implicit conversion sequences for each of the 3110 // arguments. 3111 Candidate.Viable = true; 3112 Candidate.Conversions.resize(NumArgs); 3113 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 3114 // C++ [over.match.oper]p4: 3115 // For the built-in assignment operators, conversions of the 3116 // left operand are restricted as follows: 3117 // -- no temporaries are introduced to hold the left operand, and 3118 // -- no user-defined conversions are applied to the left 3119 // operand to achieve a type match with the left-most 3120 // parameter of a built-in candidate. 3121 // 3122 // We block these conversions by turning off user-defined 3123 // conversions, since that is the only way that initialization of 3124 // a reference to a non-class type can occur from something that 3125 // is not of the same type. 3126 if (ArgIdx < NumContextualBoolArguments) { 3127 assert(ParamTys[ArgIdx] == Context.BoolTy && 3128 "Contextual conversion to bool requires bool type"); 3129 Candidate.Conversions[ArgIdx] = TryContextuallyConvertToBool(Args[ArgIdx]); 3130 } else { 3131 Candidate.Conversions[ArgIdx] 3132 = TryCopyInitialization(Args[ArgIdx], ParamTys[ArgIdx], 3133 ArgIdx == 0 && IsAssignmentOperator, 3134 /*ForceRValue=*/false, 3135 /*InOverloadResolution=*/false); 3136 } 3137 if (Candidate.Conversions[ArgIdx].isBad()) { 3138 Candidate.Viable = false; 3139 Candidate.FailureKind = ovl_fail_bad_conversion; 3140 break; 3141 } 3142 } 3143} 3144 3145/// BuiltinCandidateTypeSet - A set of types that will be used for the 3146/// candidate operator functions for built-in operators (C++ 3147/// [over.built]). The types are separated into pointer types and 3148/// enumeration types. 3149class BuiltinCandidateTypeSet { 3150 /// TypeSet - A set of types. 3151 typedef llvm::SmallPtrSet<QualType, 8> TypeSet; 3152 3153 /// PointerTypes - The set of pointer types that will be used in the 3154 /// built-in candidates. 3155 TypeSet PointerTypes; 3156 3157 /// MemberPointerTypes - The set of member pointer types that will be 3158 /// used in the built-in candidates. 3159 TypeSet MemberPointerTypes; 3160 3161 /// EnumerationTypes - The set of enumeration types that will be 3162 /// used in the built-in candidates. 3163 TypeSet EnumerationTypes; 3164 3165 /// Sema - The semantic analysis instance where we are building the 3166 /// candidate type set. 3167 Sema &SemaRef; 3168 3169 /// Context - The AST context in which we will build the type sets. 3170 ASTContext &Context; 3171 3172 bool AddPointerWithMoreQualifiedTypeVariants(QualType Ty, 3173 const Qualifiers &VisibleQuals); 3174 bool AddMemberPointerWithMoreQualifiedTypeVariants(QualType Ty); 3175 3176public: 3177 /// iterator - Iterates through the types that are part of the set. 3178 typedef TypeSet::iterator iterator; 3179 3180 BuiltinCandidateTypeSet(Sema &SemaRef) 3181 : SemaRef(SemaRef), Context(SemaRef.Context) { } 3182 3183 void AddTypesConvertedFrom(QualType Ty, 3184 SourceLocation Loc, 3185 bool AllowUserConversions, 3186 bool AllowExplicitConversions, 3187 const Qualifiers &VisibleTypeConversionsQuals); 3188 3189 /// pointer_begin - First pointer type found; 3190 iterator pointer_begin() { return PointerTypes.begin(); } 3191 3192 /// pointer_end - Past the last pointer type found; 3193 iterator pointer_end() { return PointerTypes.end(); } 3194 3195 /// member_pointer_begin - First member pointer type found; 3196 iterator member_pointer_begin() { return MemberPointerTypes.begin(); } 3197 3198 /// member_pointer_end - Past the last member pointer type found; 3199 iterator member_pointer_end() { return MemberPointerTypes.end(); } 3200 3201 /// enumeration_begin - First enumeration type found; 3202 iterator enumeration_begin() { return EnumerationTypes.begin(); } 3203 3204 /// enumeration_end - Past the last enumeration type found; 3205 iterator enumeration_end() { return EnumerationTypes.end(); } 3206}; 3207 3208/// AddPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty to 3209/// the set of pointer types along with any more-qualified variants of 3210/// that type. For example, if @p Ty is "int const *", this routine 3211/// will add "int const *", "int const volatile *", "int const 3212/// restrict *", and "int const volatile restrict *" to the set of 3213/// pointer types. Returns true if the add of @p Ty itself succeeded, 3214/// false otherwise. 3215/// 3216/// FIXME: what to do about extended qualifiers? 3217bool 3218BuiltinCandidateTypeSet::AddPointerWithMoreQualifiedTypeVariants(QualType Ty, 3219 const Qualifiers &VisibleQuals) { 3220 3221 // Insert this type. 3222 if (!PointerTypes.insert(Ty)) 3223 return false; 3224 3225 const PointerType *PointerTy = Ty->getAs<PointerType>(); 3226 assert(PointerTy && "type was not a pointer type!"); 3227 3228 QualType PointeeTy = PointerTy->getPointeeType(); 3229 // Don't add qualified variants of arrays. For one, they're not allowed 3230 // (the qualifier would sink to the element type), and for another, the 3231 // only overload situation where it matters is subscript or pointer +- int, 3232 // and those shouldn't have qualifier variants anyway. 3233 if (PointeeTy->isArrayType()) 3234 return true; 3235 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 3236 if (const ConstantArrayType *Array =Context.getAsConstantArrayType(PointeeTy)) 3237 BaseCVR = Array->getElementType().getCVRQualifiers(); 3238 bool hasVolatile = VisibleQuals.hasVolatile(); 3239 bool hasRestrict = VisibleQuals.hasRestrict(); 3240 3241 // Iterate through all strict supersets of BaseCVR. 3242 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 3243 if ((CVR | BaseCVR) != CVR) continue; 3244 // Skip over Volatile/Restrict if no Volatile/Restrict found anywhere 3245 // in the types. 3246 if ((CVR & Qualifiers::Volatile) && !hasVolatile) continue; 3247 if ((CVR & Qualifiers::Restrict) && !hasRestrict) continue; 3248 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 3249 PointerTypes.insert(Context.getPointerType(QPointeeTy)); 3250 } 3251 3252 return true; 3253} 3254 3255/// AddMemberPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty 3256/// to the set of pointer types along with any more-qualified variants of 3257/// that type. For example, if @p Ty is "int const *", this routine 3258/// will add "int const *", "int const volatile *", "int const 3259/// restrict *", and "int const volatile restrict *" to the set of 3260/// pointer types. Returns true if the add of @p Ty itself succeeded, 3261/// false otherwise. 3262/// 3263/// FIXME: what to do about extended qualifiers? 3264bool 3265BuiltinCandidateTypeSet::AddMemberPointerWithMoreQualifiedTypeVariants( 3266 QualType Ty) { 3267 // Insert this type. 3268 if (!MemberPointerTypes.insert(Ty)) 3269 return false; 3270 3271 const MemberPointerType *PointerTy = Ty->getAs<MemberPointerType>(); 3272 assert(PointerTy && "type was not a member pointer type!"); 3273 3274 QualType PointeeTy = PointerTy->getPointeeType(); 3275 // Don't add qualified variants of arrays. For one, they're not allowed 3276 // (the qualifier would sink to the element type), and for another, the 3277 // only overload situation where it matters is subscript or pointer +- int, 3278 // and those shouldn't have qualifier variants anyway. 3279 if (PointeeTy->isArrayType()) 3280 return true; 3281 const Type *ClassTy = PointerTy->getClass(); 3282 3283 // Iterate through all strict supersets of the pointee type's CVR 3284 // qualifiers. 3285 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 3286 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 3287 if ((CVR | BaseCVR) != CVR) continue; 3288 3289 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 3290 MemberPointerTypes.insert(Context.getMemberPointerType(QPointeeTy, ClassTy)); 3291 } 3292 3293 return true; 3294} 3295 3296/// AddTypesConvertedFrom - Add each of the types to which the type @p 3297/// Ty can be implicit converted to the given set of @p Types. We're 3298/// primarily interested in pointer types and enumeration types. We also 3299/// take member pointer types, for the conditional operator. 3300/// AllowUserConversions is true if we should look at the conversion 3301/// functions of a class type, and AllowExplicitConversions if we 3302/// should also include the explicit conversion functions of a class 3303/// type. 3304void 3305BuiltinCandidateTypeSet::AddTypesConvertedFrom(QualType Ty, 3306 SourceLocation Loc, 3307 bool AllowUserConversions, 3308 bool AllowExplicitConversions, 3309 const Qualifiers &VisibleQuals) { 3310 // Only deal with canonical types. 3311 Ty = Context.getCanonicalType(Ty); 3312 3313 // Look through reference types; they aren't part of the type of an 3314 // expression for the purposes of conversions. 3315 if (const ReferenceType *RefTy = Ty->getAs<ReferenceType>()) 3316 Ty = RefTy->getPointeeType(); 3317 3318 // We don't care about qualifiers on the type. 3319 Ty = Ty.getLocalUnqualifiedType(); 3320 3321 // If we're dealing with an array type, decay to the pointer. 3322 if (Ty->isArrayType()) 3323 Ty = SemaRef.Context.getArrayDecayedType(Ty); 3324 3325 if (const PointerType *PointerTy = Ty->getAs<PointerType>()) { 3326 QualType PointeeTy = PointerTy->getPointeeType(); 3327 3328 // Insert our type, and its more-qualified variants, into the set 3329 // of types. 3330 if (!AddPointerWithMoreQualifiedTypeVariants(Ty, VisibleQuals)) 3331 return; 3332 } else if (Ty->isMemberPointerType()) { 3333 // Member pointers are far easier, since the pointee can't be converted. 3334 if (!AddMemberPointerWithMoreQualifiedTypeVariants(Ty)) 3335 return; 3336 } else if (Ty->isEnumeralType()) { 3337 EnumerationTypes.insert(Ty); 3338 } else if (AllowUserConversions) { 3339 if (const RecordType *TyRec = Ty->getAs<RecordType>()) { 3340 if (SemaRef.RequireCompleteType(Loc, Ty, 0)) { 3341 // No conversion functions in incomplete types. 3342 return; 3343 } 3344 3345 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 3346 const UnresolvedSetImpl *Conversions 3347 = ClassDecl->getVisibleConversionFunctions(); 3348 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 3349 E = Conversions->end(); I != E; ++I) { 3350 3351 // Skip conversion function templates; they don't tell us anything 3352 // about which builtin types we can convert to. 3353 if (isa<FunctionTemplateDecl>(*I)) 3354 continue; 3355 3356 CXXConversionDecl *Conv = cast<CXXConversionDecl>(*I); 3357 if (AllowExplicitConversions || !Conv->isExplicit()) { 3358 AddTypesConvertedFrom(Conv->getConversionType(), Loc, false, false, 3359 VisibleQuals); 3360 } 3361 } 3362 } 3363 } 3364} 3365 3366/// \brief Helper function for AddBuiltinOperatorCandidates() that adds 3367/// the volatile- and non-volatile-qualified assignment operators for the 3368/// given type to the candidate set. 3369static void AddBuiltinAssignmentOperatorCandidates(Sema &S, 3370 QualType T, 3371 Expr **Args, 3372 unsigned NumArgs, 3373 OverloadCandidateSet &CandidateSet) { 3374 QualType ParamTypes[2]; 3375 3376 // T& operator=(T&, T) 3377 ParamTypes[0] = S.Context.getLValueReferenceType(T); 3378 ParamTypes[1] = T; 3379 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3380 /*IsAssignmentOperator=*/true); 3381 3382 if (!S.Context.getCanonicalType(T).isVolatileQualified()) { 3383 // volatile T& operator=(volatile T&, T) 3384 ParamTypes[0] 3385 = S.Context.getLValueReferenceType(S.Context.getVolatileType(T)); 3386 ParamTypes[1] = T; 3387 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3388 /*IsAssignmentOperator=*/true); 3389 } 3390} 3391 3392/// CollectVRQualifiers - This routine returns Volatile/Restrict qualifiers, 3393/// if any, found in visible type conversion functions found in ArgExpr's type. 3394static Qualifiers CollectVRQualifiers(ASTContext &Context, Expr* ArgExpr) { 3395 Qualifiers VRQuals; 3396 const RecordType *TyRec; 3397 if (const MemberPointerType *RHSMPType = 3398 ArgExpr->getType()->getAs<MemberPointerType>()) 3399 TyRec = cast<RecordType>(RHSMPType->getClass()); 3400 else 3401 TyRec = ArgExpr->getType()->getAs<RecordType>(); 3402 if (!TyRec) { 3403 // Just to be safe, assume the worst case. 3404 VRQuals.addVolatile(); 3405 VRQuals.addRestrict(); 3406 return VRQuals; 3407 } 3408 3409 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 3410 const UnresolvedSetImpl *Conversions = 3411 ClassDecl->getVisibleConversionFunctions(); 3412 3413 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 3414 E = Conversions->end(); I != E; ++I) { 3415 if (CXXConversionDecl *Conv = dyn_cast<CXXConversionDecl>(*I)) { 3416 QualType CanTy = Context.getCanonicalType(Conv->getConversionType()); 3417 if (const ReferenceType *ResTypeRef = CanTy->getAs<ReferenceType>()) 3418 CanTy = ResTypeRef->getPointeeType(); 3419 // Need to go down the pointer/mempointer chain and add qualifiers 3420 // as see them. 3421 bool done = false; 3422 while (!done) { 3423 if (const PointerType *ResTypePtr = CanTy->getAs<PointerType>()) 3424 CanTy = ResTypePtr->getPointeeType(); 3425 else if (const MemberPointerType *ResTypeMPtr = 3426 CanTy->getAs<MemberPointerType>()) 3427 CanTy = ResTypeMPtr->getPointeeType(); 3428 else 3429 done = true; 3430 if (CanTy.isVolatileQualified()) 3431 VRQuals.addVolatile(); 3432 if (CanTy.isRestrictQualified()) 3433 VRQuals.addRestrict(); 3434 if (VRQuals.hasRestrict() && VRQuals.hasVolatile()) 3435 return VRQuals; 3436 } 3437 } 3438 } 3439 return VRQuals; 3440} 3441 3442/// AddBuiltinOperatorCandidates - Add the appropriate built-in 3443/// operator overloads to the candidate set (C++ [over.built]), based 3444/// on the operator @p Op and the arguments given. For example, if the 3445/// operator is a binary '+', this routine might add "int 3446/// operator+(int, int)" to cover integer addition. 3447void 3448Sema::AddBuiltinOperatorCandidates(OverloadedOperatorKind Op, 3449 SourceLocation OpLoc, 3450 Expr **Args, unsigned NumArgs, 3451 OverloadCandidateSet& CandidateSet) { 3452 // The set of "promoted arithmetic types", which are the arithmetic 3453 // types are that preserved by promotion (C++ [over.built]p2). Note 3454 // that the first few of these types are the promoted integral 3455 // types; these types need to be first. 3456 // FIXME: What about complex? 3457 const unsigned FirstIntegralType = 0; 3458 const unsigned LastIntegralType = 13; 3459 const unsigned FirstPromotedIntegralType = 7, 3460 LastPromotedIntegralType = 13; 3461 const unsigned FirstPromotedArithmeticType = 7, 3462 LastPromotedArithmeticType = 16; 3463 const unsigned NumArithmeticTypes = 16; 3464 QualType ArithmeticTypes[NumArithmeticTypes] = { 3465 Context.BoolTy, Context.CharTy, Context.WCharTy, 3466// FIXME: Context.Char16Ty, Context.Char32Ty, 3467 Context.SignedCharTy, Context.ShortTy, 3468 Context.UnsignedCharTy, Context.UnsignedShortTy, 3469 Context.IntTy, Context.LongTy, Context.LongLongTy, 3470 Context.UnsignedIntTy, Context.UnsignedLongTy, Context.UnsignedLongLongTy, 3471 Context.FloatTy, Context.DoubleTy, Context.LongDoubleTy 3472 }; 3473 assert(ArithmeticTypes[FirstPromotedIntegralType] == Context.IntTy && 3474 "Invalid first promoted integral type"); 3475 assert(ArithmeticTypes[LastPromotedIntegralType - 1] 3476 == Context.UnsignedLongLongTy && 3477 "Invalid last promoted integral type"); 3478 assert(ArithmeticTypes[FirstPromotedArithmeticType] == Context.IntTy && 3479 "Invalid first promoted arithmetic type"); 3480 assert(ArithmeticTypes[LastPromotedArithmeticType - 1] 3481 == Context.LongDoubleTy && 3482 "Invalid last promoted arithmetic type"); 3483 3484 // Find all of the types that the arguments can convert to, but only 3485 // if the operator we're looking at has built-in operator candidates 3486 // that make use of these types. 3487 Qualifiers VisibleTypeConversionsQuals; 3488 VisibleTypeConversionsQuals.addConst(); 3489 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 3490 VisibleTypeConversionsQuals += CollectVRQualifiers(Context, Args[ArgIdx]); 3491 3492 BuiltinCandidateTypeSet CandidateTypes(*this); 3493 if (Op == OO_Less || Op == OO_Greater || Op == OO_LessEqual || 3494 Op == OO_GreaterEqual || Op == OO_EqualEqual || Op == OO_ExclaimEqual || 3495 Op == OO_Plus || (Op == OO_Minus && NumArgs == 2) || Op == OO_Equal || 3496 Op == OO_PlusEqual || Op == OO_MinusEqual || Op == OO_Subscript || 3497 Op == OO_ArrowStar || Op == OO_PlusPlus || Op == OO_MinusMinus || 3498 (Op == OO_Star && NumArgs == 1) || Op == OO_Conditional) { 3499 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 3500 CandidateTypes.AddTypesConvertedFrom(Args[ArgIdx]->getType(), 3501 OpLoc, 3502 true, 3503 (Op == OO_Exclaim || 3504 Op == OO_AmpAmp || 3505 Op == OO_PipePipe), 3506 VisibleTypeConversionsQuals); 3507 } 3508 3509 bool isComparison = false; 3510 switch (Op) { 3511 case OO_None: 3512 case NUM_OVERLOADED_OPERATORS: 3513 assert(false && "Expected an overloaded operator"); 3514 break; 3515 3516 case OO_Star: // '*' is either unary or binary 3517 if (NumArgs == 1) 3518 goto UnaryStar; 3519 else 3520 goto BinaryStar; 3521 break; 3522 3523 case OO_Plus: // '+' is either unary or binary 3524 if (NumArgs == 1) 3525 goto UnaryPlus; 3526 else 3527 goto BinaryPlus; 3528 break; 3529 3530 case OO_Minus: // '-' is either unary or binary 3531 if (NumArgs == 1) 3532 goto UnaryMinus; 3533 else 3534 goto BinaryMinus; 3535 break; 3536 3537 case OO_Amp: // '&' is either unary or binary 3538 if (NumArgs == 1) 3539 goto UnaryAmp; 3540 else 3541 goto BinaryAmp; 3542 3543 case OO_PlusPlus: 3544 case OO_MinusMinus: 3545 // C++ [over.built]p3: 3546 // 3547 // For every pair (T, VQ), where T is an arithmetic type, and VQ 3548 // is either volatile or empty, there exist candidate operator 3549 // functions of the form 3550 // 3551 // VQ T& operator++(VQ T&); 3552 // T operator++(VQ T&, int); 3553 // 3554 // C++ [over.built]p4: 3555 // 3556 // For every pair (T, VQ), where T is an arithmetic type other 3557 // than bool, and VQ is either volatile or empty, there exist 3558 // candidate operator functions of the form 3559 // 3560 // VQ T& operator--(VQ T&); 3561 // T operator--(VQ T&, int); 3562 for (unsigned Arith = (Op == OO_PlusPlus? 0 : 1); 3563 Arith < NumArithmeticTypes; ++Arith) { 3564 QualType ArithTy = ArithmeticTypes[Arith]; 3565 QualType ParamTypes[2] 3566 = { Context.getLValueReferenceType(ArithTy), Context.IntTy }; 3567 3568 // Non-volatile version. 3569 if (NumArgs == 1) 3570 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3571 else 3572 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 3573 // heuristic to reduce number of builtin candidates in the set. 3574 // Add volatile version only if there are conversions to a volatile type. 3575 if (VisibleTypeConversionsQuals.hasVolatile()) { 3576 // Volatile version 3577 ParamTypes[0] 3578 = Context.getLValueReferenceType(Context.getVolatileType(ArithTy)); 3579 if (NumArgs == 1) 3580 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3581 else 3582 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 3583 } 3584 } 3585 3586 // C++ [over.built]p5: 3587 // 3588 // For every pair (T, VQ), where T is a cv-qualified or 3589 // cv-unqualified object type, and VQ is either volatile or 3590 // empty, there exist candidate operator functions of the form 3591 // 3592 // T*VQ& operator++(T*VQ&); 3593 // T*VQ& operator--(T*VQ&); 3594 // T* operator++(T*VQ&, int); 3595 // T* operator--(T*VQ&, int); 3596 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3597 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3598 // Skip pointer types that aren't pointers to object types. 3599 if (!(*Ptr)->getAs<PointerType>()->getPointeeType()->isObjectType()) 3600 continue; 3601 3602 QualType ParamTypes[2] = { 3603 Context.getLValueReferenceType(*Ptr), Context.IntTy 3604 }; 3605 3606 // Without volatile 3607 if (NumArgs == 1) 3608 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3609 else 3610 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3611 3612 if (!Context.getCanonicalType(*Ptr).isVolatileQualified() && 3613 VisibleTypeConversionsQuals.hasVolatile()) { 3614 // With volatile 3615 ParamTypes[0] 3616 = Context.getLValueReferenceType(Context.getVolatileType(*Ptr)); 3617 if (NumArgs == 1) 3618 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3619 else 3620 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3621 } 3622 } 3623 break; 3624 3625 UnaryStar: 3626 // C++ [over.built]p6: 3627 // For every cv-qualified or cv-unqualified object type T, there 3628 // exist candidate operator functions of the form 3629 // 3630 // T& operator*(T*); 3631 // 3632 // C++ [over.built]p7: 3633 // For every function type T, there exist candidate operator 3634 // functions of the form 3635 // T& operator*(T*); 3636 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3637 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3638 QualType ParamTy = *Ptr; 3639 QualType PointeeTy = ParamTy->getAs<PointerType>()->getPointeeType(); 3640 AddBuiltinCandidate(Context.getLValueReferenceType(PointeeTy), 3641 &ParamTy, Args, 1, CandidateSet); 3642 } 3643 break; 3644 3645 UnaryPlus: 3646 // C++ [over.built]p8: 3647 // For every type T, there exist candidate operator functions of 3648 // the form 3649 // 3650 // T* operator+(T*); 3651 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3652 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3653 QualType ParamTy = *Ptr; 3654 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet); 3655 } 3656 3657 // Fall through 3658 3659 UnaryMinus: 3660 // C++ [over.built]p9: 3661 // For every promoted arithmetic type T, there exist candidate 3662 // operator functions of the form 3663 // 3664 // T operator+(T); 3665 // T operator-(T); 3666 for (unsigned Arith = FirstPromotedArithmeticType; 3667 Arith < LastPromotedArithmeticType; ++Arith) { 3668 QualType ArithTy = ArithmeticTypes[Arith]; 3669 AddBuiltinCandidate(ArithTy, &ArithTy, Args, 1, CandidateSet); 3670 } 3671 break; 3672 3673 case OO_Tilde: 3674 // C++ [over.built]p10: 3675 // For every promoted integral type T, there exist candidate 3676 // operator functions of the form 3677 // 3678 // T operator~(T); 3679 for (unsigned Int = FirstPromotedIntegralType; 3680 Int < LastPromotedIntegralType; ++Int) { 3681 QualType IntTy = ArithmeticTypes[Int]; 3682 AddBuiltinCandidate(IntTy, &IntTy, Args, 1, CandidateSet); 3683 } 3684 break; 3685 3686 case OO_New: 3687 case OO_Delete: 3688 case OO_Array_New: 3689 case OO_Array_Delete: 3690 case OO_Call: 3691 assert(false && "Special operators don't use AddBuiltinOperatorCandidates"); 3692 break; 3693 3694 case OO_Comma: 3695 UnaryAmp: 3696 case OO_Arrow: 3697 // C++ [over.match.oper]p3: 3698 // -- For the operator ',', the unary operator '&', or the 3699 // operator '->', the built-in candidates set is empty. 3700 break; 3701 3702 case OO_EqualEqual: 3703 case OO_ExclaimEqual: 3704 // C++ [over.match.oper]p16: 3705 // For every pointer to member type T, there exist candidate operator 3706 // functions of the form 3707 // 3708 // bool operator==(T,T); 3709 // bool operator!=(T,T); 3710 for (BuiltinCandidateTypeSet::iterator 3711 MemPtr = CandidateTypes.member_pointer_begin(), 3712 MemPtrEnd = CandidateTypes.member_pointer_end(); 3713 MemPtr != MemPtrEnd; 3714 ++MemPtr) { 3715 QualType ParamTypes[2] = { *MemPtr, *MemPtr }; 3716 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 3717 } 3718 3719 // Fall through 3720 3721 case OO_Less: 3722 case OO_Greater: 3723 case OO_LessEqual: 3724 case OO_GreaterEqual: 3725 // C++ [over.built]p15: 3726 // 3727 // For every pointer or enumeration type T, there exist 3728 // candidate operator functions of the form 3729 // 3730 // bool operator<(T, T); 3731 // bool operator>(T, T); 3732 // bool operator<=(T, T); 3733 // bool operator>=(T, T); 3734 // bool operator==(T, T); 3735 // bool operator!=(T, T); 3736 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3737 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3738 QualType ParamTypes[2] = { *Ptr, *Ptr }; 3739 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 3740 } 3741 for (BuiltinCandidateTypeSet::iterator Enum 3742 = CandidateTypes.enumeration_begin(); 3743 Enum != CandidateTypes.enumeration_end(); ++Enum) { 3744 QualType ParamTypes[2] = { *Enum, *Enum }; 3745 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 3746 } 3747 3748 // Fall through. 3749 isComparison = true; 3750 3751 BinaryPlus: 3752 BinaryMinus: 3753 if (!isComparison) { 3754 // We didn't fall through, so we must have OO_Plus or OO_Minus. 3755 3756 // C++ [over.built]p13: 3757 // 3758 // For every cv-qualified or cv-unqualified object type T 3759 // there exist candidate operator functions of the form 3760 // 3761 // T* operator+(T*, ptrdiff_t); 3762 // T& operator[](T*, ptrdiff_t); [BELOW] 3763 // T* operator-(T*, ptrdiff_t); 3764 // T* operator+(ptrdiff_t, T*); 3765 // T& operator[](ptrdiff_t, T*); [BELOW] 3766 // 3767 // C++ [over.built]p14: 3768 // 3769 // For every T, where T is a pointer to object type, there 3770 // exist candidate operator functions of the form 3771 // 3772 // ptrdiff_t operator-(T, T); 3773 for (BuiltinCandidateTypeSet::iterator Ptr 3774 = CandidateTypes.pointer_begin(); 3775 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3776 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 3777 3778 // operator+(T*, ptrdiff_t) or operator-(T*, ptrdiff_t) 3779 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3780 3781 if (Op == OO_Plus) { 3782 // T* operator+(ptrdiff_t, T*); 3783 ParamTypes[0] = ParamTypes[1]; 3784 ParamTypes[1] = *Ptr; 3785 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3786 } else { 3787 // ptrdiff_t operator-(T, T); 3788 ParamTypes[1] = *Ptr; 3789 AddBuiltinCandidate(Context.getPointerDiffType(), ParamTypes, 3790 Args, 2, CandidateSet); 3791 } 3792 } 3793 } 3794 // Fall through 3795 3796 case OO_Slash: 3797 BinaryStar: 3798 Conditional: 3799 // C++ [over.built]p12: 3800 // 3801 // For every pair of promoted arithmetic types L and R, there 3802 // exist candidate operator functions of the form 3803 // 3804 // LR operator*(L, R); 3805 // LR operator/(L, R); 3806 // LR operator+(L, R); 3807 // LR operator-(L, R); 3808 // bool operator<(L, R); 3809 // bool operator>(L, R); 3810 // bool operator<=(L, R); 3811 // bool operator>=(L, R); 3812 // bool operator==(L, R); 3813 // bool operator!=(L, R); 3814 // 3815 // where LR is the result of the usual arithmetic conversions 3816 // between types L and R. 3817 // 3818 // C++ [over.built]p24: 3819 // 3820 // For every pair of promoted arithmetic types L and R, there exist 3821 // candidate operator functions of the form 3822 // 3823 // LR operator?(bool, L, R); 3824 // 3825 // where LR is the result of the usual arithmetic conversions 3826 // between types L and R. 3827 // Our candidates ignore the first parameter. 3828 for (unsigned Left = FirstPromotedArithmeticType; 3829 Left < LastPromotedArithmeticType; ++Left) { 3830 for (unsigned Right = FirstPromotedArithmeticType; 3831 Right < LastPromotedArithmeticType; ++Right) { 3832 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 3833 QualType Result 3834 = isComparison 3835 ? Context.BoolTy 3836 : Context.UsualArithmeticConversionsType(LandR[0], LandR[1]); 3837 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 3838 } 3839 } 3840 break; 3841 3842 case OO_Percent: 3843 BinaryAmp: 3844 case OO_Caret: 3845 case OO_Pipe: 3846 case OO_LessLess: 3847 case OO_GreaterGreater: 3848 // C++ [over.built]p17: 3849 // 3850 // For every pair of promoted integral types L and R, there 3851 // exist candidate operator functions of the form 3852 // 3853 // LR operator%(L, R); 3854 // LR operator&(L, R); 3855 // LR operator^(L, R); 3856 // LR operator|(L, R); 3857 // L operator<<(L, R); 3858 // L operator>>(L, R); 3859 // 3860 // where LR is the result of the usual arithmetic conversions 3861 // between types L and R. 3862 for (unsigned Left = FirstPromotedIntegralType; 3863 Left < LastPromotedIntegralType; ++Left) { 3864 for (unsigned Right = FirstPromotedIntegralType; 3865 Right < LastPromotedIntegralType; ++Right) { 3866 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 3867 QualType Result = (Op == OO_LessLess || Op == OO_GreaterGreater) 3868 ? LandR[0] 3869 : Context.UsualArithmeticConversionsType(LandR[0], LandR[1]); 3870 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 3871 } 3872 } 3873 break; 3874 3875 case OO_Equal: 3876 // C++ [over.built]p20: 3877 // 3878 // For every pair (T, VQ), where T is an enumeration or 3879 // pointer to member type and VQ is either volatile or 3880 // empty, there exist candidate operator functions of the form 3881 // 3882 // VQ T& operator=(VQ T&, T); 3883 for (BuiltinCandidateTypeSet::iterator 3884 Enum = CandidateTypes.enumeration_begin(), 3885 EnumEnd = CandidateTypes.enumeration_end(); 3886 Enum != EnumEnd; ++Enum) 3887 AddBuiltinAssignmentOperatorCandidates(*this, *Enum, Args, 2, 3888 CandidateSet); 3889 for (BuiltinCandidateTypeSet::iterator 3890 MemPtr = CandidateTypes.member_pointer_begin(), 3891 MemPtrEnd = CandidateTypes.member_pointer_end(); 3892 MemPtr != MemPtrEnd; ++MemPtr) 3893 AddBuiltinAssignmentOperatorCandidates(*this, *MemPtr, Args, 2, 3894 CandidateSet); 3895 // Fall through. 3896 3897 case OO_PlusEqual: 3898 case OO_MinusEqual: 3899 // C++ [over.built]p19: 3900 // 3901 // For every pair (T, VQ), where T is any type and VQ is either 3902 // volatile or empty, there exist candidate operator functions 3903 // of the form 3904 // 3905 // T*VQ& operator=(T*VQ&, T*); 3906 // 3907 // C++ [over.built]p21: 3908 // 3909 // For every pair (T, VQ), where T is a cv-qualified or 3910 // cv-unqualified object type and VQ is either volatile or 3911 // empty, there exist candidate operator functions of the form 3912 // 3913 // T*VQ& operator+=(T*VQ&, ptrdiff_t); 3914 // T*VQ& operator-=(T*VQ&, ptrdiff_t); 3915 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3916 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3917 QualType ParamTypes[2]; 3918 ParamTypes[1] = (Op == OO_Equal)? *Ptr : Context.getPointerDiffType(); 3919 3920 // non-volatile version 3921 ParamTypes[0] = Context.getLValueReferenceType(*Ptr); 3922 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3923 /*IsAssigmentOperator=*/Op == OO_Equal); 3924 3925 if (!Context.getCanonicalType(*Ptr).isVolatileQualified() && 3926 VisibleTypeConversionsQuals.hasVolatile()) { 3927 // volatile version 3928 ParamTypes[0] 3929 = Context.getLValueReferenceType(Context.getVolatileType(*Ptr)); 3930 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3931 /*IsAssigmentOperator=*/Op == OO_Equal); 3932 } 3933 } 3934 // Fall through. 3935 3936 case OO_StarEqual: 3937 case OO_SlashEqual: 3938 // C++ [over.built]p18: 3939 // 3940 // For every triple (L, VQ, R), where L is an arithmetic type, 3941 // VQ is either volatile or empty, and R is a promoted 3942 // arithmetic type, there exist candidate operator functions of 3943 // the form 3944 // 3945 // VQ L& operator=(VQ L&, R); 3946 // VQ L& operator*=(VQ L&, R); 3947 // VQ L& operator/=(VQ L&, R); 3948 // VQ L& operator+=(VQ L&, R); 3949 // VQ L& operator-=(VQ L&, R); 3950 for (unsigned Left = 0; Left < NumArithmeticTypes; ++Left) { 3951 for (unsigned Right = FirstPromotedArithmeticType; 3952 Right < LastPromotedArithmeticType; ++Right) { 3953 QualType ParamTypes[2]; 3954 ParamTypes[1] = ArithmeticTypes[Right]; 3955 3956 // Add this built-in operator as a candidate (VQ is empty). 3957 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 3958 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3959 /*IsAssigmentOperator=*/Op == OO_Equal); 3960 3961 // Add this built-in operator as a candidate (VQ is 'volatile'). 3962 if (VisibleTypeConversionsQuals.hasVolatile()) { 3963 ParamTypes[0] = Context.getVolatileType(ArithmeticTypes[Left]); 3964 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 3965 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3966 /*IsAssigmentOperator=*/Op == OO_Equal); 3967 } 3968 } 3969 } 3970 break; 3971 3972 case OO_PercentEqual: 3973 case OO_LessLessEqual: 3974 case OO_GreaterGreaterEqual: 3975 case OO_AmpEqual: 3976 case OO_CaretEqual: 3977 case OO_PipeEqual: 3978 // C++ [over.built]p22: 3979 // 3980 // For every triple (L, VQ, R), where L is an integral type, VQ 3981 // is either volatile or empty, and R is a promoted integral 3982 // type, there exist candidate operator functions of the form 3983 // 3984 // VQ L& operator%=(VQ L&, R); 3985 // VQ L& operator<<=(VQ L&, R); 3986 // VQ L& operator>>=(VQ L&, R); 3987 // VQ L& operator&=(VQ L&, R); 3988 // VQ L& operator^=(VQ L&, R); 3989 // VQ L& operator|=(VQ L&, R); 3990 for (unsigned Left = FirstIntegralType; Left < LastIntegralType; ++Left) { 3991 for (unsigned Right = FirstPromotedIntegralType; 3992 Right < LastPromotedIntegralType; ++Right) { 3993 QualType ParamTypes[2]; 3994 ParamTypes[1] = ArithmeticTypes[Right]; 3995 3996 // Add this built-in operator as a candidate (VQ is empty). 3997 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 3998 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 3999 if (VisibleTypeConversionsQuals.hasVolatile()) { 4000 // Add this built-in operator as a candidate (VQ is 'volatile'). 4001 ParamTypes[0] = ArithmeticTypes[Left]; 4002 ParamTypes[0] = Context.getVolatileType(ParamTypes[0]); 4003 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 4004 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 4005 } 4006 } 4007 } 4008 break; 4009 4010 case OO_Exclaim: { 4011 // C++ [over.operator]p23: 4012 // 4013 // There also exist candidate operator functions of the form 4014 // 4015 // bool operator!(bool); 4016 // bool operator&&(bool, bool); [BELOW] 4017 // bool operator||(bool, bool); [BELOW] 4018 QualType ParamTy = Context.BoolTy; 4019 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet, 4020 /*IsAssignmentOperator=*/false, 4021 /*NumContextualBoolArguments=*/1); 4022 break; 4023 } 4024 4025 case OO_AmpAmp: 4026 case OO_PipePipe: { 4027 // C++ [over.operator]p23: 4028 // 4029 // There also exist candidate operator functions of the form 4030 // 4031 // bool operator!(bool); [ABOVE] 4032 // bool operator&&(bool, bool); 4033 // bool operator||(bool, bool); 4034 QualType ParamTypes[2] = { Context.BoolTy, Context.BoolTy }; 4035 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet, 4036 /*IsAssignmentOperator=*/false, 4037 /*NumContextualBoolArguments=*/2); 4038 break; 4039 } 4040 4041 case OO_Subscript: 4042 // C++ [over.built]p13: 4043 // 4044 // For every cv-qualified or cv-unqualified object type T there 4045 // exist candidate operator functions of the form 4046 // 4047 // T* operator+(T*, ptrdiff_t); [ABOVE] 4048 // T& operator[](T*, ptrdiff_t); 4049 // T* operator-(T*, ptrdiff_t); [ABOVE] 4050 // T* operator+(ptrdiff_t, T*); [ABOVE] 4051 // T& operator[](ptrdiff_t, T*); 4052 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 4053 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4054 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 4055 QualType PointeeType = (*Ptr)->getAs<PointerType>()->getPointeeType(); 4056 QualType ResultTy = Context.getLValueReferenceType(PointeeType); 4057 4058 // T& operator[](T*, ptrdiff_t) 4059 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 4060 4061 // T& operator[](ptrdiff_t, T*); 4062 ParamTypes[0] = ParamTypes[1]; 4063 ParamTypes[1] = *Ptr; 4064 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 4065 } 4066 break; 4067 4068 case OO_ArrowStar: 4069 // C++ [over.built]p11: 4070 // For every quintuple (C1, C2, T, CV1, CV2), where C2 is a class type, 4071 // C1 is the same type as C2 or is a derived class of C2, T is an object 4072 // type or a function type, and CV1 and CV2 are cv-qualifier-seqs, 4073 // there exist candidate operator functions of the form 4074 // CV12 T& operator->*(CV1 C1*, CV2 T C2::*); 4075 // where CV12 is the union of CV1 and CV2. 4076 { 4077 for (BuiltinCandidateTypeSet::iterator Ptr = 4078 CandidateTypes.pointer_begin(); 4079 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4080 QualType C1Ty = (*Ptr); 4081 QualType C1; 4082 QualifierCollector Q1; 4083 if (const PointerType *PointerTy = C1Ty->getAs<PointerType>()) { 4084 C1 = QualType(Q1.strip(PointerTy->getPointeeType()), 0); 4085 if (!isa<RecordType>(C1)) 4086 continue; 4087 // heuristic to reduce number of builtin candidates in the set. 4088 // Add volatile/restrict version only if there are conversions to a 4089 // volatile/restrict type. 4090 if (!VisibleTypeConversionsQuals.hasVolatile() && Q1.hasVolatile()) 4091 continue; 4092 if (!VisibleTypeConversionsQuals.hasRestrict() && Q1.hasRestrict()) 4093 continue; 4094 } 4095 for (BuiltinCandidateTypeSet::iterator 4096 MemPtr = CandidateTypes.member_pointer_begin(), 4097 MemPtrEnd = CandidateTypes.member_pointer_end(); 4098 MemPtr != MemPtrEnd; ++MemPtr) { 4099 const MemberPointerType *mptr = cast<MemberPointerType>(*MemPtr); 4100 QualType C2 = QualType(mptr->getClass(), 0); 4101 C2 = C2.getUnqualifiedType(); 4102 if (C1 != C2 && !IsDerivedFrom(C1, C2)) 4103 break; 4104 QualType ParamTypes[2] = { *Ptr, *MemPtr }; 4105 // build CV12 T& 4106 QualType T = mptr->getPointeeType(); 4107 if (!VisibleTypeConversionsQuals.hasVolatile() && 4108 T.isVolatileQualified()) 4109 continue; 4110 if (!VisibleTypeConversionsQuals.hasRestrict() && 4111 T.isRestrictQualified()) 4112 continue; 4113 T = Q1.apply(T); 4114 QualType ResultTy = Context.getLValueReferenceType(T); 4115 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 4116 } 4117 } 4118 } 4119 break; 4120 4121 case OO_Conditional: 4122 // Note that we don't consider the first argument, since it has been 4123 // contextually converted to bool long ago. The candidates below are 4124 // therefore added as binary. 4125 // 4126 // C++ [over.built]p24: 4127 // For every type T, where T is a pointer or pointer-to-member type, 4128 // there exist candidate operator functions of the form 4129 // 4130 // T operator?(bool, T, T); 4131 // 4132 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(), 4133 E = CandidateTypes.pointer_end(); Ptr != E; ++Ptr) { 4134 QualType ParamTypes[2] = { *Ptr, *Ptr }; 4135 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 4136 } 4137 for (BuiltinCandidateTypeSet::iterator Ptr = 4138 CandidateTypes.member_pointer_begin(), 4139 E = CandidateTypes.member_pointer_end(); Ptr != E; ++Ptr) { 4140 QualType ParamTypes[2] = { *Ptr, *Ptr }; 4141 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 4142 } 4143 goto Conditional; 4144 } 4145} 4146 4147/// \brief Add function candidates found via argument-dependent lookup 4148/// to the set of overloading candidates. 4149/// 4150/// This routine performs argument-dependent name lookup based on the 4151/// given function name (which may also be an operator name) and adds 4152/// all of the overload candidates found by ADL to the overload 4153/// candidate set (C++ [basic.lookup.argdep]). 4154void 4155Sema::AddArgumentDependentLookupCandidates(DeclarationName Name, 4156 bool Operator, 4157 Expr **Args, unsigned NumArgs, 4158 const TemplateArgumentListInfo *ExplicitTemplateArgs, 4159 OverloadCandidateSet& CandidateSet, 4160 bool PartialOverloading) { 4161 ADLResult Fns; 4162 4163 // FIXME: This approach for uniquing ADL results (and removing 4164 // redundant candidates from the set) relies on pointer-equality, 4165 // which means we need to key off the canonical decl. However, 4166 // always going back to the canonical decl might not get us the 4167 // right set of default arguments. What default arguments are 4168 // we supposed to consider on ADL candidates, anyway? 4169 4170 // FIXME: Pass in the explicit template arguments? 4171 ArgumentDependentLookup(Name, Operator, Args, NumArgs, Fns); 4172 4173 // Erase all of the candidates we already knew about. 4174 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 4175 CandEnd = CandidateSet.end(); 4176 Cand != CandEnd; ++Cand) 4177 if (Cand->Function) { 4178 Fns.erase(Cand->Function); 4179 if (FunctionTemplateDecl *FunTmpl = Cand->Function->getPrimaryTemplate()) 4180 Fns.erase(FunTmpl); 4181 } 4182 4183 // For each of the ADL candidates we found, add it to the overload 4184 // set. 4185 for (ADLResult::iterator I = Fns.begin(), E = Fns.end(); I != E; ++I) { 4186 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*I)) { 4187 if (ExplicitTemplateArgs) 4188 continue; 4189 4190 AddOverloadCandidate(FD, AS_none, Args, NumArgs, CandidateSet, 4191 false, false, PartialOverloading); 4192 } else 4193 AddTemplateOverloadCandidate(cast<FunctionTemplateDecl>(*I), 4194 AS_none, ExplicitTemplateArgs, 4195 Args, NumArgs, CandidateSet); 4196 } 4197} 4198 4199/// isBetterOverloadCandidate - Determines whether the first overload 4200/// candidate is a better candidate than the second (C++ 13.3.3p1). 4201bool 4202Sema::isBetterOverloadCandidate(const OverloadCandidate& Cand1, 4203 const OverloadCandidate& Cand2) { 4204 // Define viable functions to be better candidates than non-viable 4205 // functions. 4206 if (!Cand2.Viable) 4207 return Cand1.Viable; 4208 else if (!Cand1.Viable) 4209 return false; 4210 4211 // C++ [over.match.best]p1: 4212 // 4213 // -- if F is a static member function, ICS1(F) is defined such 4214 // that ICS1(F) is neither better nor worse than ICS1(G) for 4215 // any function G, and, symmetrically, ICS1(G) is neither 4216 // better nor worse than ICS1(F). 4217 unsigned StartArg = 0; 4218 if (Cand1.IgnoreObjectArgument || Cand2.IgnoreObjectArgument) 4219 StartArg = 1; 4220 4221 // C++ [over.match.best]p1: 4222 // A viable function F1 is defined to be a better function than another 4223 // viable function F2 if for all arguments i, ICSi(F1) is not a worse 4224 // conversion sequence than ICSi(F2), and then... 4225 unsigned NumArgs = Cand1.Conversions.size(); 4226 assert(Cand2.Conversions.size() == NumArgs && "Overload candidate mismatch"); 4227 bool HasBetterConversion = false; 4228 for (unsigned ArgIdx = StartArg; ArgIdx < NumArgs; ++ArgIdx) { 4229 switch (CompareImplicitConversionSequences(Cand1.Conversions[ArgIdx], 4230 Cand2.Conversions[ArgIdx])) { 4231 case ImplicitConversionSequence::Better: 4232 // Cand1 has a better conversion sequence. 4233 HasBetterConversion = true; 4234 break; 4235 4236 case ImplicitConversionSequence::Worse: 4237 // Cand1 can't be better than Cand2. 4238 return false; 4239 4240 case ImplicitConversionSequence::Indistinguishable: 4241 // Do nothing. 4242 break; 4243 } 4244 } 4245 4246 // -- for some argument j, ICSj(F1) is a better conversion sequence than 4247 // ICSj(F2), or, if not that, 4248 if (HasBetterConversion) 4249 return true; 4250 4251 // - F1 is a non-template function and F2 is a function template 4252 // specialization, or, if not that, 4253 if (Cand1.Function && !Cand1.Function->getPrimaryTemplate() && 4254 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 4255 return true; 4256 4257 // -- F1 and F2 are function template specializations, and the function 4258 // template for F1 is more specialized than the template for F2 4259 // according to the partial ordering rules described in 14.5.5.2, or, 4260 // if not that, 4261 if (Cand1.Function && Cand1.Function->getPrimaryTemplate() && 4262 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 4263 if (FunctionTemplateDecl *BetterTemplate 4264 = getMoreSpecializedTemplate(Cand1.Function->getPrimaryTemplate(), 4265 Cand2.Function->getPrimaryTemplate(), 4266 isa<CXXConversionDecl>(Cand1.Function)? TPOC_Conversion 4267 : TPOC_Call)) 4268 return BetterTemplate == Cand1.Function->getPrimaryTemplate(); 4269 4270 // -- the context is an initialization by user-defined conversion 4271 // (see 8.5, 13.3.1.5) and the standard conversion sequence 4272 // from the return type of F1 to the destination type (i.e., 4273 // the type of the entity being initialized) is a better 4274 // conversion sequence than the standard conversion sequence 4275 // from the return type of F2 to the destination type. 4276 if (Cand1.Function && Cand2.Function && 4277 isa<CXXConversionDecl>(Cand1.Function) && 4278 isa<CXXConversionDecl>(Cand2.Function)) { 4279 switch (CompareStandardConversionSequences(Cand1.FinalConversion, 4280 Cand2.FinalConversion)) { 4281 case ImplicitConversionSequence::Better: 4282 // Cand1 has a better conversion sequence. 4283 return true; 4284 4285 case ImplicitConversionSequence::Worse: 4286 // Cand1 can't be better than Cand2. 4287 return false; 4288 4289 case ImplicitConversionSequence::Indistinguishable: 4290 // Do nothing 4291 break; 4292 } 4293 } 4294 4295 return false; 4296} 4297 4298/// \brief Computes the best viable function (C++ 13.3.3) 4299/// within an overload candidate set. 4300/// 4301/// \param CandidateSet the set of candidate functions. 4302/// 4303/// \param Loc the location of the function name (or operator symbol) for 4304/// which overload resolution occurs. 4305/// 4306/// \param Best f overload resolution was successful or found a deleted 4307/// function, Best points to the candidate function found. 4308/// 4309/// \returns The result of overload resolution. 4310OverloadingResult Sema::BestViableFunction(OverloadCandidateSet& CandidateSet, 4311 SourceLocation Loc, 4312 OverloadCandidateSet::iterator& Best) { 4313 // Find the best viable function. 4314 Best = CandidateSet.end(); 4315 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 4316 Cand != CandidateSet.end(); ++Cand) { 4317 if (Cand->Viable) { 4318 if (Best == CandidateSet.end() || isBetterOverloadCandidate(*Cand, *Best)) 4319 Best = Cand; 4320 } 4321 } 4322 4323 // If we didn't find any viable functions, abort. 4324 if (Best == CandidateSet.end()) 4325 return OR_No_Viable_Function; 4326 4327 // Make sure that this function is better than every other viable 4328 // function. If not, we have an ambiguity. 4329 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 4330 Cand != CandidateSet.end(); ++Cand) { 4331 if (Cand->Viable && 4332 Cand != Best && 4333 !isBetterOverloadCandidate(*Best, *Cand)) { 4334 Best = CandidateSet.end(); 4335 return OR_Ambiguous; 4336 } 4337 } 4338 4339 // Best is the best viable function. 4340 if (Best->Function && 4341 (Best->Function->isDeleted() || 4342 Best->Function->getAttr<UnavailableAttr>())) 4343 return OR_Deleted; 4344 4345 // C++ [basic.def.odr]p2: 4346 // An overloaded function is used if it is selected by overload resolution 4347 // when referred to from a potentially-evaluated expression. [Note: this 4348 // covers calls to named functions (5.2.2), operator overloading 4349 // (clause 13), user-defined conversions (12.3.2), allocation function for 4350 // placement new (5.3.4), as well as non-default initialization (8.5). 4351 if (Best->Function) 4352 MarkDeclarationReferenced(Loc, Best->Function); 4353 return OR_Success; 4354} 4355 4356namespace { 4357 4358enum OverloadCandidateKind { 4359 oc_function, 4360 oc_method, 4361 oc_constructor, 4362 oc_function_template, 4363 oc_method_template, 4364 oc_constructor_template, 4365 oc_implicit_default_constructor, 4366 oc_implicit_copy_constructor, 4367 oc_implicit_copy_assignment 4368}; 4369 4370OverloadCandidateKind ClassifyOverloadCandidate(Sema &S, 4371 FunctionDecl *Fn, 4372 std::string &Description) { 4373 bool isTemplate = false; 4374 4375 if (FunctionTemplateDecl *FunTmpl = Fn->getPrimaryTemplate()) { 4376 isTemplate = true; 4377 Description = S.getTemplateArgumentBindingsText( 4378 FunTmpl->getTemplateParameters(), *Fn->getTemplateSpecializationArgs()); 4379 } 4380 4381 if (CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(Fn)) { 4382 if (!Ctor->isImplicit()) 4383 return isTemplate ? oc_constructor_template : oc_constructor; 4384 4385 return Ctor->isCopyConstructor() ? oc_implicit_copy_constructor 4386 : oc_implicit_default_constructor; 4387 } 4388 4389 if (CXXMethodDecl *Meth = dyn_cast<CXXMethodDecl>(Fn)) { 4390 // This actually gets spelled 'candidate function' for now, but 4391 // it doesn't hurt to split it out. 4392 if (!Meth->isImplicit()) 4393 return isTemplate ? oc_method_template : oc_method; 4394 4395 assert(Meth->isCopyAssignment() 4396 && "implicit method is not copy assignment operator?"); 4397 return oc_implicit_copy_assignment; 4398 } 4399 4400 return isTemplate ? oc_function_template : oc_function; 4401} 4402 4403} // end anonymous namespace 4404 4405// Notes the location of an overload candidate. 4406void Sema::NoteOverloadCandidate(FunctionDecl *Fn) { 4407 std::string FnDesc; 4408 OverloadCandidateKind K = ClassifyOverloadCandidate(*this, Fn, FnDesc); 4409 Diag(Fn->getLocation(), diag::note_ovl_candidate) 4410 << (unsigned) K << FnDesc; 4411} 4412 4413/// Diagnoses an ambiguous conversion. The partial diagnostic is the 4414/// "lead" diagnostic; it will be given two arguments, the source and 4415/// target types of the conversion. 4416void Sema::DiagnoseAmbiguousConversion(const ImplicitConversionSequence &ICS, 4417 SourceLocation CaretLoc, 4418 const PartialDiagnostic &PDiag) { 4419 Diag(CaretLoc, PDiag) 4420 << ICS.Ambiguous.getFromType() << ICS.Ambiguous.getToType(); 4421 for (AmbiguousConversionSequence::const_iterator 4422 I = ICS.Ambiguous.begin(), E = ICS.Ambiguous.end(); I != E; ++I) { 4423 NoteOverloadCandidate(*I); 4424 } 4425} 4426 4427namespace { 4428 4429void DiagnoseBadConversion(Sema &S, OverloadCandidate *Cand, unsigned I) { 4430 const ImplicitConversionSequence &Conv = Cand->Conversions[I]; 4431 assert(Conv.isBad()); 4432 assert(Cand->Function && "for now, candidate must be a function"); 4433 FunctionDecl *Fn = Cand->Function; 4434 4435 // There's a conversion slot for the object argument if this is a 4436 // non-constructor method. Note that 'I' corresponds the 4437 // conversion-slot index. 4438 bool isObjectArgument = false; 4439 if (isa<CXXMethodDecl>(Fn) && !isa<CXXConstructorDecl>(Fn)) { 4440 if (I == 0) 4441 isObjectArgument = true; 4442 else 4443 I--; 4444 } 4445 4446 std::string FnDesc; 4447 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, FnDesc); 4448 4449 Expr *FromExpr = Conv.Bad.FromExpr; 4450 QualType FromTy = Conv.Bad.getFromType(); 4451 QualType ToTy = Conv.Bad.getToType(); 4452 4453 if (FromTy == S.Context.OverloadTy) { 4454 assert(FromExpr); 4455 Expr *E = FromExpr->IgnoreParens(); 4456 if (isa<UnaryOperator>(E)) 4457 E = cast<UnaryOperator>(E)->getSubExpr()->IgnoreParens(); 4458 DeclarationName Name; 4459 if (isa<UnresolvedLookupExpr>(E)) 4460 Name = cast<UnresolvedLookupExpr>(E)->getName(); 4461 else 4462 Name = cast<UnresolvedMemberExpr>(E)->getMemberName(); 4463 4464 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_overload) 4465 << (unsigned) FnKind << FnDesc 4466 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 4467 << ToTy << Name << I+1; 4468 return; 4469 } 4470 4471 // Do some hand-waving analysis to see if the non-viability is due 4472 // to a qualifier mismatch. 4473 CanQualType CFromTy = S.Context.getCanonicalType(FromTy); 4474 CanQualType CToTy = S.Context.getCanonicalType(ToTy); 4475 if (CanQual<ReferenceType> RT = CToTy->getAs<ReferenceType>()) 4476 CToTy = RT->getPointeeType(); 4477 else { 4478 // TODO: detect and diagnose the full richness of const mismatches. 4479 if (CanQual<PointerType> FromPT = CFromTy->getAs<PointerType>()) 4480 if (CanQual<PointerType> ToPT = CToTy->getAs<PointerType>()) 4481 CFromTy = FromPT->getPointeeType(), CToTy = ToPT->getPointeeType(); 4482 } 4483 4484 if (CToTy.getUnqualifiedType() == CFromTy.getUnqualifiedType() && 4485 !CToTy.isAtLeastAsQualifiedAs(CFromTy)) { 4486 // It is dumb that we have to do this here. 4487 while (isa<ArrayType>(CFromTy)) 4488 CFromTy = CFromTy->getAs<ArrayType>()->getElementType(); 4489 while (isa<ArrayType>(CToTy)) 4490 CToTy = CFromTy->getAs<ArrayType>()->getElementType(); 4491 4492 Qualifiers FromQs = CFromTy.getQualifiers(); 4493 Qualifiers ToQs = CToTy.getQualifiers(); 4494 4495 if (FromQs.getAddressSpace() != ToQs.getAddressSpace()) { 4496 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_addrspace) 4497 << (unsigned) FnKind << FnDesc 4498 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 4499 << FromTy 4500 << FromQs.getAddressSpace() << ToQs.getAddressSpace() 4501 << (unsigned) isObjectArgument << I+1; 4502 return; 4503 } 4504 4505 unsigned CVR = FromQs.getCVRQualifiers() & ~ToQs.getCVRQualifiers(); 4506 assert(CVR && "unexpected qualifiers mismatch"); 4507 4508 if (isObjectArgument) { 4509 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr_this) 4510 << (unsigned) FnKind << FnDesc 4511 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 4512 << FromTy << (CVR - 1); 4513 } else { 4514 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr) 4515 << (unsigned) FnKind << FnDesc 4516 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 4517 << FromTy << (CVR - 1) << I+1; 4518 } 4519 return; 4520 } 4521 4522 // Diagnose references or pointers to incomplete types differently, 4523 // since it's far from impossible that the incompleteness triggered 4524 // the failure. 4525 QualType TempFromTy = FromTy.getNonReferenceType(); 4526 if (const PointerType *PTy = TempFromTy->getAs<PointerType>()) 4527 TempFromTy = PTy->getPointeeType(); 4528 if (TempFromTy->isIncompleteType()) { 4529 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_conv_incomplete) 4530 << (unsigned) FnKind << FnDesc 4531 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 4532 << FromTy << ToTy << (unsigned) isObjectArgument << I+1; 4533 return; 4534 } 4535 4536 // TODO: specialize more based on the kind of mismatch 4537 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_conv) 4538 << (unsigned) FnKind << FnDesc 4539 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 4540 << FromTy << ToTy << (unsigned) isObjectArgument << I+1; 4541} 4542 4543void DiagnoseArityMismatch(Sema &S, OverloadCandidate *Cand, 4544 unsigned NumFormalArgs) { 4545 // TODO: treat calls to a missing default constructor as a special case 4546 4547 FunctionDecl *Fn = Cand->Function; 4548 const FunctionProtoType *FnTy = Fn->getType()->getAs<FunctionProtoType>(); 4549 4550 unsigned MinParams = Fn->getMinRequiredArguments(); 4551 4552 // at least / at most / exactly 4553 unsigned mode, modeCount; 4554 if (NumFormalArgs < MinParams) { 4555 assert(Cand->FailureKind == ovl_fail_too_few_arguments); 4556 if (MinParams != FnTy->getNumArgs() || FnTy->isVariadic()) 4557 mode = 0; // "at least" 4558 else 4559 mode = 2; // "exactly" 4560 modeCount = MinParams; 4561 } else { 4562 assert(Cand->FailureKind == ovl_fail_too_many_arguments); 4563 if (MinParams != FnTy->getNumArgs()) 4564 mode = 1; // "at most" 4565 else 4566 mode = 2; // "exactly" 4567 modeCount = FnTy->getNumArgs(); 4568 } 4569 4570 std::string Description; 4571 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, Description); 4572 4573 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_arity) 4574 << (unsigned) FnKind << Description << mode << modeCount << NumFormalArgs; 4575} 4576 4577/// Diagnose a failed template-argument deduction. 4578void DiagnoseBadDeduction(Sema &S, OverloadCandidate *Cand, 4579 Expr **Args, unsigned NumArgs) { 4580 FunctionDecl *Fn = Cand->Function; // pattern 4581 4582 TemplateParameter Param = TemplateParameter::getFromOpaqueValue( 4583 Cand->DeductionFailure.TemplateParameter); 4584 4585 switch (Cand->DeductionFailure.Result) { 4586 case Sema::TDK_Success: 4587 llvm_unreachable("TDK_success while diagnosing bad deduction"); 4588 4589 case Sema::TDK_Incomplete: { 4590 NamedDecl *ParamD; 4591 (ParamD = Param.dyn_cast<TemplateTypeParmDecl*>()) || 4592 (ParamD = Param.dyn_cast<NonTypeTemplateParmDecl*>()) || 4593 (ParamD = Param.dyn_cast<TemplateTemplateParmDecl*>()); 4594 assert(ParamD && "no parameter found for incomplete deduction result"); 4595 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_incomplete_deduction) 4596 << ParamD->getDeclName(); 4597 return; 4598 } 4599 4600 // TODO: diagnose these individually, then kill off 4601 // note_ovl_candidate_bad_deduction, which is uselessly vague. 4602 case Sema::TDK_InstantiationDepth: 4603 case Sema::TDK_Inconsistent: 4604 case Sema::TDK_InconsistentQuals: 4605 case Sema::TDK_SubstitutionFailure: 4606 case Sema::TDK_NonDeducedMismatch: 4607 case Sema::TDK_TooManyArguments: 4608 case Sema::TDK_TooFewArguments: 4609 case Sema::TDK_InvalidExplicitArguments: 4610 case Sema::TDK_FailedOverloadResolution: 4611 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_deduction); 4612 return; 4613 } 4614} 4615 4616/// Generates a 'note' diagnostic for an overload candidate. We've 4617/// already generated a primary error at the call site. 4618/// 4619/// It really does need to be a single diagnostic with its caret 4620/// pointed at the candidate declaration. Yes, this creates some 4621/// major challenges of technical writing. Yes, this makes pointing 4622/// out problems with specific arguments quite awkward. It's still 4623/// better than generating twenty screens of text for every failed 4624/// overload. 4625/// 4626/// It would be great to be able to express per-candidate problems 4627/// more richly for those diagnostic clients that cared, but we'd 4628/// still have to be just as careful with the default diagnostics. 4629void NoteFunctionCandidate(Sema &S, OverloadCandidate *Cand, 4630 Expr **Args, unsigned NumArgs) { 4631 FunctionDecl *Fn = Cand->Function; 4632 4633 // Note deleted candidates, but only if they're viable. 4634 if (Cand->Viable && (Fn->isDeleted() || Fn->hasAttr<UnavailableAttr>())) { 4635 std::string FnDesc; 4636 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, FnDesc); 4637 4638 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_deleted) 4639 << FnKind << FnDesc << Fn->isDeleted(); 4640 return; 4641 } 4642 4643 // We don't really have anything else to say about viable candidates. 4644 if (Cand->Viable) { 4645 S.NoteOverloadCandidate(Fn); 4646 return; 4647 } 4648 4649 switch (Cand->FailureKind) { 4650 case ovl_fail_too_many_arguments: 4651 case ovl_fail_too_few_arguments: 4652 return DiagnoseArityMismatch(S, Cand, NumArgs); 4653 4654 case ovl_fail_bad_deduction: 4655 return DiagnoseBadDeduction(S, Cand, Args, NumArgs); 4656 4657 case ovl_fail_trivial_conversion: 4658 case ovl_fail_bad_final_conversion: 4659 return S.NoteOverloadCandidate(Fn); 4660 4661 case ovl_fail_bad_conversion: 4662 for (unsigned I = 0, N = Cand->Conversions.size(); I != N; ++I) 4663 if (Cand->Conversions[I].isBad()) 4664 return DiagnoseBadConversion(S, Cand, I); 4665 4666 // FIXME: this currently happens when we're called from SemaInit 4667 // when user-conversion overload fails. Figure out how to handle 4668 // those conditions and diagnose them well. 4669 return S.NoteOverloadCandidate(Fn); 4670 } 4671} 4672 4673void NoteSurrogateCandidate(Sema &S, OverloadCandidate *Cand) { 4674 // Desugar the type of the surrogate down to a function type, 4675 // retaining as many typedefs as possible while still showing 4676 // the function type (and, therefore, its parameter types). 4677 QualType FnType = Cand->Surrogate->getConversionType(); 4678 bool isLValueReference = false; 4679 bool isRValueReference = false; 4680 bool isPointer = false; 4681 if (const LValueReferenceType *FnTypeRef = 4682 FnType->getAs<LValueReferenceType>()) { 4683 FnType = FnTypeRef->getPointeeType(); 4684 isLValueReference = true; 4685 } else if (const RValueReferenceType *FnTypeRef = 4686 FnType->getAs<RValueReferenceType>()) { 4687 FnType = FnTypeRef->getPointeeType(); 4688 isRValueReference = true; 4689 } 4690 if (const PointerType *FnTypePtr = FnType->getAs<PointerType>()) { 4691 FnType = FnTypePtr->getPointeeType(); 4692 isPointer = true; 4693 } 4694 // Desugar down to a function type. 4695 FnType = QualType(FnType->getAs<FunctionType>(), 0); 4696 // Reconstruct the pointer/reference as appropriate. 4697 if (isPointer) FnType = S.Context.getPointerType(FnType); 4698 if (isRValueReference) FnType = S.Context.getRValueReferenceType(FnType); 4699 if (isLValueReference) FnType = S.Context.getLValueReferenceType(FnType); 4700 4701 S.Diag(Cand->Surrogate->getLocation(), diag::note_ovl_surrogate_cand) 4702 << FnType; 4703} 4704 4705void NoteBuiltinOperatorCandidate(Sema &S, 4706 const char *Opc, 4707 SourceLocation OpLoc, 4708 OverloadCandidate *Cand) { 4709 assert(Cand->Conversions.size() <= 2 && "builtin operator is not binary"); 4710 std::string TypeStr("operator"); 4711 TypeStr += Opc; 4712 TypeStr += "("; 4713 TypeStr += Cand->BuiltinTypes.ParamTypes[0].getAsString(); 4714 if (Cand->Conversions.size() == 1) { 4715 TypeStr += ")"; 4716 S.Diag(OpLoc, diag::note_ovl_builtin_unary_candidate) << TypeStr; 4717 } else { 4718 TypeStr += ", "; 4719 TypeStr += Cand->BuiltinTypes.ParamTypes[1].getAsString(); 4720 TypeStr += ")"; 4721 S.Diag(OpLoc, diag::note_ovl_builtin_binary_candidate) << TypeStr; 4722 } 4723} 4724 4725void NoteAmbiguousUserConversions(Sema &S, SourceLocation OpLoc, 4726 OverloadCandidate *Cand) { 4727 unsigned NoOperands = Cand->Conversions.size(); 4728 for (unsigned ArgIdx = 0; ArgIdx < NoOperands; ++ArgIdx) { 4729 const ImplicitConversionSequence &ICS = Cand->Conversions[ArgIdx]; 4730 if (ICS.isBad()) break; // all meaningless after first invalid 4731 if (!ICS.isAmbiguous()) continue; 4732 4733 S.DiagnoseAmbiguousConversion(ICS, OpLoc, 4734 PDiag(diag::note_ambiguous_type_conversion)); 4735 } 4736} 4737 4738SourceLocation GetLocationForCandidate(const OverloadCandidate *Cand) { 4739 if (Cand->Function) 4740 return Cand->Function->getLocation(); 4741 if (Cand->IsSurrogate) 4742 return Cand->Surrogate->getLocation(); 4743 return SourceLocation(); 4744} 4745 4746struct CompareOverloadCandidatesForDisplay { 4747 Sema &S; 4748 CompareOverloadCandidatesForDisplay(Sema &S) : S(S) {} 4749 4750 bool operator()(const OverloadCandidate *L, 4751 const OverloadCandidate *R) { 4752 // Fast-path this check. 4753 if (L == R) return false; 4754 4755 // Order first by viability. 4756 if (L->Viable) { 4757 if (!R->Viable) return true; 4758 4759 // TODO: introduce a tri-valued comparison for overload 4760 // candidates. Would be more worthwhile if we had a sort 4761 // that could exploit it. 4762 if (S.isBetterOverloadCandidate(*L, *R)) return true; 4763 if (S.isBetterOverloadCandidate(*R, *L)) return false; 4764 } else if (R->Viable) 4765 return false; 4766 4767 assert(L->Viable == R->Viable); 4768 4769 // Criteria by which we can sort non-viable candidates: 4770 if (!L->Viable) { 4771 // 1. Arity mismatches come after other candidates. 4772 if (L->FailureKind == ovl_fail_too_many_arguments || 4773 L->FailureKind == ovl_fail_too_few_arguments) 4774 return false; 4775 if (R->FailureKind == ovl_fail_too_many_arguments || 4776 R->FailureKind == ovl_fail_too_few_arguments) 4777 return true; 4778 4779 // 2. Bad conversions come first and are ordered by the number 4780 // of bad conversions and quality of good conversions. 4781 if (L->FailureKind == ovl_fail_bad_conversion) { 4782 if (R->FailureKind != ovl_fail_bad_conversion) 4783 return true; 4784 4785 // If there's any ordering between the defined conversions... 4786 // FIXME: this might not be transitive. 4787 assert(L->Conversions.size() == R->Conversions.size()); 4788 4789 int leftBetter = 0; 4790 for (unsigned I = 0, E = L->Conversions.size(); I != E; ++I) { 4791 switch (S.CompareImplicitConversionSequences(L->Conversions[I], 4792 R->Conversions[I])) { 4793 case ImplicitConversionSequence::Better: 4794 leftBetter++; 4795 break; 4796 4797 case ImplicitConversionSequence::Worse: 4798 leftBetter--; 4799 break; 4800 4801 case ImplicitConversionSequence::Indistinguishable: 4802 break; 4803 } 4804 } 4805 if (leftBetter > 0) return true; 4806 if (leftBetter < 0) return false; 4807 4808 } else if (R->FailureKind == ovl_fail_bad_conversion) 4809 return false; 4810 4811 // TODO: others? 4812 } 4813 4814 // Sort everything else by location. 4815 SourceLocation LLoc = GetLocationForCandidate(L); 4816 SourceLocation RLoc = GetLocationForCandidate(R); 4817 4818 // Put candidates without locations (e.g. builtins) at the end. 4819 if (LLoc.isInvalid()) return false; 4820 if (RLoc.isInvalid()) return true; 4821 4822 return S.SourceMgr.isBeforeInTranslationUnit(LLoc, RLoc); 4823 } 4824}; 4825 4826/// CompleteNonViableCandidate - Normally, overload resolution only 4827/// computes up to the first 4828void CompleteNonViableCandidate(Sema &S, OverloadCandidate *Cand, 4829 Expr **Args, unsigned NumArgs) { 4830 assert(!Cand->Viable); 4831 4832 // Don't do anything on failures other than bad conversion. 4833 if (Cand->FailureKind != ovl_fail_bad_conversion) return; 4834 4835 // Skip forward to the first bad conversion. 4836 unsigned ConvIdx = 0; 4837 unsigned ConvCount = Cand->Conversions.size(); 4838 while (true) { 4839 assert(ConvIdx != ConvCount && "no bad conversion in candidate"); 4840 ConvIdx++; 4841 if (Cand->Conversions[ConvIdx - 1].isBad()) 4842 break; 4843 } 4844 4845 if (ConvIdx == ConvCount) 4846 return; 4847 4848 // FIXME: these should probably be preserved from the overload 4849 // operation somehow. 4850 bool SuppressUserConversions = false; 4851 bool ForceRValue = false; 4852 4853 const FunctionProtoType* Proto; 4854 unsigned ArgIdx = ConvIdx; 4855 4856 if (Cand->IsSurrogate) { 4857 QualType ConvType 4858 = Cand->Surrogate->getConversionType().getNonReferenceType(); 4859 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 4860 ConvType = ConvPtrType->getPointeeType(); 4861 Proto = ConvType->getAs<FunctionProtoType>(); 4862 ArgIdx--; 4863 } else if (Cand->Function) { 4864 Proto = Cand->Function->getType()->getAs<FunctionProtoType>(); 4865 if (isa<CXXMethodDecl>(Cand->Function) && 4866 !isa<CXXConstructorDecl>(Cand->Function)) 4867 ArgIdx--; 4868 } else { 4869 // Builtin binary operator with a bad first conversion. 4870 assert(ConvCount <= 3); 4871 for (; ConvIdx != ConvCount; ++ConvIdx) 4872 Cand->Conversions[ConvIdx] 4873 = S.TryCopyInitialization(Args[ConvIdx], 4874 Cand->BuiltinTypes.ParamTypes[ConvIdx], 4875 SuppressUserConversions, ForceRValue, 4876 /*InOverloadResolution*/ true); 4877 return; 4878 } 4879 4880 // Fill in the rest of the conversions. 4881 unsigned NumArgsInProto = Proto->getNumArgs(); 4882 for (; ConvIdx != ConvCount; ++ConvIdx, ++ArgIdx) { 4883 if (ArgIdx < NumArgsInProto) 4884 Cand->Conversions[ConvIdx] 4885 = S.TryCopyInitialization(Args[ArgIdx], Proto->getArgType(ArgIdx), 4886 SuppressUserConversions, ForceRValue, 4887 /*InOverloadResolution=*/true); 4888 else 4889 Cand->Conversions[ConvIdx].setEllipsis(); 4890 } 4891} 4892 4893} // end anonymous namespace 4894 4895/// PrintOverloadCandidates - When overload resolution fails, prints 4896/// diagnostic messages containing the candidates in the candidate 4897/// set. 4898void 4899Sema::PrintOverloadCandidates(OverloadCandidateSet& CandidateSet, 4900 OverloadCandidateDisplayKind OCD, 4901 Expr **Args, unsigned NumArgs, 4902 const char *Opc, 4903 SourceLocation OpLoc) { 4904 // Sort the candidates by viability and position. Sorting directly would 4905 // be prohibitive, so we make a set of pointers and sort those. 4906 llvm::SmallVector<OverloadCandidate*, 32> Cands; 4907 if (OCD == OCD_AllCandidates) Cands.reserve(CandidateSet.size()); 4908 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 4909 LastCand = CandidateSet.end(); 4910 Cand != LastCand; ++Cand) { 4911 if (Cand->Viable) 4912 Cands.push_back(Cand); 4913 else if (OCD == OCD_AllCandidates) { 4914 CompleteNonViableCandidate(*this, Cand, Args, NumArgs); 4915 Cands.push_back(Cand); 4916 } 4917 } 4918 4919 std::sort(Cands.begin(), Cands.end(), 4920 CompareOverloadCandidatesForDisplay(*this)); 4921 4922 bool ReportedAmbiguousConversions = false; 4923 4924 llvm::SmallVectorImpl<OverloadCandidate*>::iterator I, E; 4925 for (I = Cands.begin(), E = Cands.end(); I != E; ++I) { 4926 OverloadCandidate *Cand = *I; 4927 4928 if (Cand->Function) 4929 NoteFunctionCandidate(*this, Cand, Args, NumArgs); 4930 else if (Cand->IsSurrogate) 4931 NoteSurrogateCandidate(*this, Cand); 4932 4933 // This a builtin candidate. We do not, in general, want to list 4934 // every possible builtin candidate. 4935 else if (Cand->Viable) { 4936 // Generally we only see ambiguities including viable builtin 4937 // operators if overload resolution got screwed up by an 4938 // ambiguous user-defined conversion. 4939 // 4940 // FIXME: It's quite possible for different conversions to see 4941 // different ambiguities, though. 4942 if (!ReportedAmbiguousConversions) { 4943 NoteAmbiguousUserConversions(*this, OpLoc, Cand); 4944 ReportedAmbiguousConversions = true; 4945 } 4946 4947 // If this is a viable builtin, print it. 4948 NoteBuiltinOperatorCandidate(*this, Opc, OpLoc, Cand); 4949 } 4950 } 4951} 4952 4953static bool CheckUnresolvedAccess(Sema &S, Expr *E, NamedDecl *D, 4954 AccessSpecifier AS) { 4955 if (isa<UnresolvedLookupExpr>(E)) 4956 return S.CheckUnresolvedLookupAccess(cast<UnresolvedLookupExpr>(E), D, AS); 4957 4958 return S.CheckUnresolvedMemberAccess(cast<UnresolvedMemberExpr>(E), D, AS); 4959} 4960 4961/// ResolveAddressOfOverloadedFunction - Try to resolve the address of 4962/// an overloaded function (C++ [over.over]), where @p From is an 4963/// expression with overloaded function type and @p ToType is the type 4964/// we're trying to resolve to. For example: 4965/// 4966/// @code 4967/// int f(double); 4968/// int f(int); 4969/// 4970/// int (*pfd)(double) = f; // selects f(double) 4971/// @endcode 4972/// 4973/// This routine returns the resulting FunctionDecl if it could be 4974/// resolved, and NULL otherwise. When @p Complain is true, this 4975/// routine will emit diagnostics if there is an error. 4976FunctionDecl * 4977Sema::ResolveAddressOfOverloadedFunction(Expr *From, QualType ToType, 4978 bool Complain) { 4979 QualType FunctionType = ToType; 4980 bool IsMember = false; 4981 if (const PointerType *ToTypePtr = ToType->getAs<PointerType>()) 4982 FunctionType = ToTypePtr->getPointeeType(); 4983 else if (const ReferenceType *ToTypeRef = ToType->getAs<ReferenceType>()) 4984 FunctionType = ToTypeRef->getPointeeType(); 4985 else if (const MemberPointerType *MemTypePtr = 4986 ToType->getAs<MemberPointerType>()) { 4987 FunctionType = MemTypePtr->getPointeeType(); 4988 IsMember = true; 4989 } 4990 4991 // We only look at pointers or references to functions. 4992 FunctionType = Context.getCanonicalType(FunctionType).getUnqualifiedType(); 4993 if (!FunctionType->isFunctionType()) 4994 return 0; 4995 4996 // Find the actual overloaded function declaration. 4997 4998 // C++ [over.over]p1: 4999 // [...] [Note: any redundant set of parentheses surrounding the 5000 // overloaded function name is ignored (5.1). ] 5001 Expr *OvlExpr = From->IgnoreParens(); 5002 5003 // C++ [over.over]p1: 5004 // [...] The overloaded function name can be preceded by the & 5005 // operator. 5006 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(OvlExpr)) { 5007 if (UnOp->getOpcode() == UnaryOperator::AddrOf) 5008 OvlExpr = UnOp->getSubExpr()->IgnoreParens(); 5009 } 5010 5011 bool HasExplicitTemplateArgs = false; 5012 TemplateArgumentListInfo ExplicitTemplateArgs; 5013 const UnresolvedSetImpl *Fns; 5014 5015 // Look into the overloaded expression. 5016 if (UnresolvedLookupExpr *UL 5017 = dyn_cast<UnresolvedLookupExpr>(OvlExpr)) { 5018 Fns = &UL->getDecls(); 5019 if (UL->hasExplicitTemplateArgs()) { 5020 HasExplicitTemplateArgs = true; 5021 UL->copyTemplateArgumentsInto(ExplicitTemplateArgs); 5022 } 5023 } else if (UnresolvedMemberExpr *ME 5024 = dyn_cast<UnresolvedMemberExpr>(OvlExpr)) { 5025 Fns = &ME->getDecls(); 5026 if (ME->hasExplicitTemplateArgs()) { 5027 HasExplicitTemplateArgs = true; 5028 ME->copyTemplateArgumentsInto(ExplicitTemplateArgs); 5029 } 5030 } else return 0; 5031 5032 // If we didn't actually find anything, we're done. 5033 if (Fns->empty()) 5034 return 0; 5035 5036 // Look through all of the overloaded functions, searching for one 5037 // whose type matches exactly. 5038 UnresolvedSet<4> Matches; // contains only FunctionDecls 5039 bool FoundNonTemplateFunction = false; 5040 for (UnresolvedSetIterator I = Fns->begin(), E = Fns->end(); I != E; ++I) { 5041 // Look through any using declarations to find the underlying function. 5042 NamedDecl *Fn = (*I)->getUnderlyingDecl(); 5043 5044 // C++ [over.over]p3: 5045 // Non-member functions and static member functions match 5046 // targets of type "pointer-to-function" or "reference-to-function." 5047 // Nonstatic member functions match targets of 5048 // type "pointer-to-member-function." 5049 // Note that according to DR 247, the containing class does not matter. 5050 5051 if (FunctionTemplateDecl *FunctionTemplate 5052 = dyn_cast<FunctionTemplateDecl>(Fn)) { 5053 if (CXXMethodDecl *Method 5054 = dyn_cast<CXXMethodDecl>(FunctionTemplate->getTemplatedDecl())) { 5055 // Skip non-static function templates when converting to pointer, and 5056 // static when converting to member pointer. 5057 if (Method->isStatic() == IsMember) 5058 continue; 5059 } else if (IsMember) 5060 continue; 5061 5062 // C++ [over.over]p2: 5063 // If the name is a function template, template argument deduction is 5064 // done (14.8.2.2), and if the argument deduction succeeds, the 5065 // resulting template argument list is used to generate a single 5066 // function template specialization, which is added to the set of 5067 // overloaded functions considered. 5068 // FIXME: We don't really want to build the specialization here, do we? 5069 FunctionDecl *Specialization = 0; 5070 TemplateDeductionInfo Info(Context); 5071 if (TemplateDeductionResult Result 5072 = DeduceTemplateArguments(FunctionTemplate, 5073 (HasExplicitTemplateArgs ? &ExplicitTemplateArgs : 0), 5074 FunctionType, Specialization, Info)) { 5075 // FIXME: make a note of the failed deduction for diagnostics. 5076 (void)Result; 5077 } else { 5078 // FIXME: If the match isn't exact, shouldn't we just drop this as 5079 // a candidate? Find a testcase before changing the code. 5080 assert(FunctionType 5081 == Context.getCanonicalType(Specialization->getType())); 5082 Matches.addDecl(cast<FunctionDecl>(Specialization->getCanonicalDecl()), 5083 I.getAccess()); 5084 } 5085 5086 continue; 5087 } 5088 5089 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 5090 // Skip non-static functions when converting to pointer, and static 5091 // when converting to member pointer. 5092 if (Method->isStatic() == IsMember) 5093 continue; 5094 5095 // If we have explicit template arguments, skip non-templates. 5096 if (HasExplicitTemplateArgs) 5097 continue; 5098 } else if (IsMember) 5099 continue; 5100 5101 if (FunctionDecl *FunDecl = dyn_cast<FunctionDecl>(Fn)) { 5102 QualType ResultTy; 5103 if (Context.hasSameUnqualifiedType(FunctionType, FunDecl->getType()) || 5104 IsNoReturnConversion(Context, FunDecl->getType(), FunctionType, 5105 ResultTy)) { 5106 Matches.addDecl(cast<FunctionDecl>(FunDecl->getCanonicalDecl()), 5107 I.getAccess()); 5108 FoundNonTemplateFunction = true; 5109 } 5110 } 5111 } 5112 5113 // If there were 0 or 1 matches, we're done. 5114 if (Matches.empty()) 5115 return 0; 5116 else if (Matches.size() == 1) { 5117 FunctionDecl *Result = cast<FunctionDecl>(*Matches.begin()); 5118 MarkDeclarationReferenced(From->getLocStart(), Result); 5119 if (Complain) 5120 CheckUnresolvedAccess(*this, OvlExpr, Result, Matches.begin().getAccess()); 5121 return Result; 5122 } 5123 5124 // C++ [over.over]p4: 5125 // If more than one function is selected, [...] 5126 if (!FoundNonTemplateFunction) { 5127 // [...] and any given function template specialization F1 is 5128 // eliminated if the set contains a second function template 5129 // specialization whose function template is more specialized 5130 // than the function template of F1 according to the partial 5131 // ordering rules of 14.5.5.2. 5132 5133 // The algorithm specified above is quadratic. We instead use a 5134 // two-pass algorithm (similar to the one used to identify the 5135 // best viable function in an overload set) that identifies the 5136 // best function template (if it exists). 5137 5138 UnresolvedSetIterator Result = 5139 getMostSpecialized(Matches.begin(), Matches.end(), 5140 TPOC_Other, From->getLocStart(), 5141 PDiag(), 5142 PDiag(diag::err_addr_ovl_ambiguous) 5143 << Matches[0]->getDeclName(), 5144 PDiag(diag::note_ovl_candidate) 5145 << (unsigned) oc_function_template); 5146 assert(Result != Matches.end() && "no most-specialized template"); 5147 MarkDeclarationReferenced(From->getLocStart(), *Result); 5148 if (Complain) 5149 CheckUnresolvedAccess(*this, OvlExpr, *Result, Result.getAccess()); 5150 return cast<FunctionDecl>(*Result); 5151 } 5152 5153 // [...] any function template specializations in the set are 5154 // eliminated if the set also contains a non-template function, [...] 5155 for (unsigned I = 0, N = Matches.size(); I != N; ) { 5156 if (cast<FunctionDecl>(Matches[I].getDecl())->getPrimaryTemplate() == 0) 5157 ++I; 5158 else { 5159 Matches.erase(I); 5160 --N; 5161 } 5162 } 5163 5164 // [...] After such eliminations, if any, there shall remain exactly one 5165 // selected function. 5166 if (Matches.size() == 1) { 5167 UnresolvedSetIterator Match = Matches.begin(); 5168 MarkDeclarationReferenced(From->getLocStart(), *Match); 5169 if (Complain) 5170 CheckUnresolvedAccess(*this, OvlExpr, *Match, Match.getAccess()); 5171 return cast<FunctionDecl>(*Match); 5172 } 5173 5174 // FIXME: We should probably return the same thing that BestViableFunction 5175 // returns (even if we issue the diagnostics here). 5176 Diag(From->getLocStart(), diag::err_addr_ovl_ambiguous) 5177 << Matches[0]->getDeclName(); 5178 for (UnresolvedSetIterator I = Matches.begin(), 5179 E = Matches.end(); I != E; ++I) 5180 NoteOverloadCandidate(cast<FunctionDecl>(*I)); 5181 return 0; 5182} 5183 5184/// \brief Given an expression that refers to an overloaded function, try to 5185/// resolve that overloaded function expression down to a single function. 5186/// 5187/// This routine can only resolve template-ids that refer to a single function 5188/// template, where that template-id refers to a single template whose template 5189/// arguments are either provided by the template-id or have defaults, 5190/// as described in C++0x [temp.arg.explicit]p3. 5191FunctionDecl *Sema::ResolveSingleFunctionTemplateSpecialization(Expr *From) { 5192 // C++ [over.over]p1: 5193 // [...] [Note: any redundant set of parentheses surrounding the 5194 // overloaded function name is ignored (5.1). ] 5195 Expr *OvlExpr = From->IgnoreParens(); 5196 5197 // C++ [over.over]p1: 5198 // [...] The overloaded function name can be preceded by the & 5199 // operator. 5200 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(OvlExpr)) { 5201 if (UnOp->getOpcode() == UnaryOperator::AddrOf) 5202 OvlExpr = UnOp->getSubExpr()->IgnoreParens(); 5203 } 5204 5205 bool HasExplicitTemplateArgs = false; 5206 TemplateArgumentListInfo ExplicitTemplateArgs; 5207 const UnresolvedSetImpl *Fns; 5208 5209 // Look into the overloaded expression. 5210 if (UnresolvedLookupExpr *UL 5211 = dyn_cast<UnresolvedLookupExpr>(OvlExpr)) { 5212 Fns = &UL->getDecls(); 5213 if (UL->hasExplicitTemplateArgs()) { 5214 HasExplicitTemplateArgs = true; 5215 UL->copyTemplateArgumentsInto(ExplicitTemplateArgs); 5216 } 5217 } else if (UnresolvedMemberExpr *ME 5218 = dyn_cast<UnresolvedMemberExpr>(OvlExpr)) { 5219 Fns = &ME->getDecls(); 5220 if (ME->hasExplicitTemplateArgs()) { 5221 HasExplicitTemplateArgs = true; 5222 ME->copyTemplateArgumentsInto(ExplicitTemplateArgs); 5223 } 5224 } else return 0; 5225 5226 // If we didn't actually find any template-ids, we're done. 5227 if (Fns->empty() || !HasExplicitTemplateArgs) 5228 return 0; 5229 5230 // Look through all of the overloaded functions, searching for one 5231 // whose type matches exactly. 5232 FunctionDecl *Matched = 0; 5233 for (UnresolvedSetIterator I = Fns->begin(), E = Fns->end(); I != E; ++I) { 5234 // C++0x [temp.arg.explicit]p3: 5235 // [...] In contexts where deduction is done and fails, or in contexts 5236 // where deduction is not done, if a template argument list is 5237 // specified and it, along with any default template arguments, 5238 // identifies a single function template specialization, then the 5239 // template-id is an lvalue for the function template specialization. 5240 FunctionTemplateDecl *FunctionTemplate = cast<FunctionTemplateDecl>(*I); 5241 5242 // C++ [over.over]p2: 5243 // If the name is a function template, template argument deduction is 5244 // done (14.8.2.2), and if the argument deduction succeeds, the 5245 // resulting template argument list is used to generate a single 5246 // function template specialization, which is added to the set of 5247 // overloaded functions considered. 5248 FunctionDecl *Specialization = 0; 5249 TemplateDeductionInfo Info(Context); 5250 if (TemplateDeductionResult Result 5251 = DeduceTemplateArguments(FunctionTemplate, &ExplicitTemplateArgs, 5252 Specialization, Info)) { 5253 // FIXME: make a note of the failed deduction for diagnostics. 5254 (void)Result; 5255 continue; 5256 } 5257 5258 // Multiple matches; we can't resolve to a single declaration. 5259 if (Matched) 5260 return 0; 5261 5262 Matched = Specialization; 5263 } 5264 5265 return Matched; 5266} 5267 5268/// \brief Add a single candidate to the overload set. 5269static void AddOverloadedCallCandidate(Sema &S, 5270 NamedDecl *Callee, 5271 AccessSpecifier Access, 5272 const TemplateArgumentListInfo *ExplicitTemplateArgs, 5273 Expr **Args, unsigned NumArgs, 5274 OverloadCandidateSet &CandidateSet, 5275 bool PartialOverloading) { 5276 if (isa<UsingShadowDecl>(Callee)) 5277 Callee = cast<UsingShadowDecl>(Callee)->getTargetDecl(); 5278 5279 if (FunctionDecl *Func = dyn_cast<FunctionDecl>(Callee)) { 5280 assert(!ExplicitTemplateArgs && "Explicit template arguments?"); 5281 S.AddOverloadCandidate(Func, Access, Args, NumArgs, CandidateSet, 5282 false, false, PartialOverloading); 5283 return; 5284 } 5285 5286 if (FunctionTemplateDecl *FuncTemplate 5287 = dyn_cast<FunctionTemplateDecl>(Callee)) { 5288 S.AddTemplateOverloadCandidate(FuncTemplate, Access, ExplicitTemplateArgs, 5289 Args, NumArgs, CandidateSet); 5290 return; 5291 } 5292 5293 assert(false && "unhandled case in overloaded call candidate"); 5294 5295 // do nothing? 5296} 5297 5298/// \brief Add the overload candidates named by callee and/or found by argument 5299/// dependent lookup to the given overload set. 5300void Sema::AddOverloadedCallCandidates(UnresolvedLookupExpr *ULE, 5301 Expr **Args, unsigned NumArgs, 5302 OverloadCandidateSet &CandidateSet, 5303 bool PartialOverloading) { 5304 5305#ifndef NDEBUG 5306 // Verify that ArgumentDependentLookup is consistent with the rules 5307 // in C++0x [basic.lookup.argdep]p3: 5308 // 5309 // Let X be the lookup set produced by unqualified lookup (3.4.1) 5310 // and let Y be the lookup set produced by argument dependent 5311 // lookup (defined as follows). If X contains 5312 // 5313 // -- a declaration of a class member, or 5314 // 5315 // -- a block-scope function declaration that is not a 5316 // using-declaration, or 5317 // 5318 // -- a declaration that is neither a function or a function 5319 // template 5320 // 5321 // then Y is empty. 5322 5323 if (ULE->requiresADL()) { 5324 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(), 5325 E = ULE->decls_end(); I != E; ++I) { 5326 assert(!(*I)->getDeclContext()->isRecord()); 5327 assert(isa<UsingShadowDecl>(*I) || 5328 !(*I)->getDeclContext()->isFunctionOrMethod()); 5329 assert((*I)->getUnderlyingDecl()->isFunctionOrFunctionTemplate()); 5330 } 5331 } 5332#endif 5333 5334 // It would be nice to avoid this copy. 5335 TemplateArgumentListInfo TABuffer; 5336 const TemplateArgumentListInfo *ExplicitTemplateArgs = 0; 5337 if (ULE->hasExplicitTemplateArgs()) { 5338 ULE->copyTemplateArgumentsInto(TABuffer); 5339 ExplicitTemplateArgs = &TABuffer; 5340 } 5341 5342 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(), 5343 E = ULE->decls_end(); I != E; ++I) 5344 AddOverloadedCallCandidate(*this, *I, I.getAccess(), ExplicitTemplateArgs, 5345 Args, NumArgs, CandidateSet, 5346 PartialOverloading); 5347 5348 if (ULE->requiresADL()) 5349 AddArgumentDependentLookupCandidates(ULE->getName(), /*Operator*/ false, 5350 Args, NumArgs, 5351 ExplicitTemplateArgs, 5352 CandidateSet, 5353 PartialOverloading); 5354} 5355 5356static Sema::OwningExprResult Destroy(Sema &SemaRef, Expr *Fn, 5357 Expr **Args, unsigned NumArgs) { 5358 Fn->Destroy(SemaRef.Context); 5359 for (unsigned Arg = 0; Arg < NumArgs; ++Arg) 5360 Args[Arg]->Destroy(SemaRef.Context); 5361 return SemaRef.ExprError(); 5362} 5363 5364/// Attempts to recover from a call where no functions were found. 5365/// 5366/// Returns true if new candidates were found. 5367static Sema::OwningExprResult 5368BuildRecoveryCallExpr(Sema &SemaRef, Expr *Fn, 5369 UnresolvedLookupExpr *ULE, 5370 SourceLocation LParenLoc, 5371 Expr **Args, unsigned NumArgs, 5372 SourceLocation *CommaLocs, 5373 SourceLocation RParenLoc) { 5374 5375 CXXScopeSpec SS; 5376 if (ULE->getQualifier()) { 5377 SS.setScopeRep(ULE->getQualifier()); 5378 SS.setRange(ULE->getQualifierRange()); 5379 } 5380 5381 TemplateArgumentListInfo TABuffer; 5382 const TemplateArgumentListInfo *ExplicitTemplateArgs = 0; 5383 if (ULE->hasExplicitTemplateArgs()) { 5384 ULE->copyTemplateArgumentsInto(TABuffer); 5385 ExplicitTemplateArgs = &TABuffer; 5386 } 5387 5388 LookupResult R(SemaRef, ULE->getName(), ULE->getNameLoc(), 5389 Sema::LookupOrdinaryName); 5390 if (SemaRef.DiagnoseEmptyLookup(/*Scope=*/0, SS, R)) 5391 return Destroy(SemaRef, Fn, Args, NumArgs); 5392 5393 assert(!R.empty() && "lookup results empty despite recovery"); 5394 5395 // Build an implicit member call if appropriate. Just drop the 5396 // casts and such from the call, we don't really care. 5397 Sema::OwningExprResult NewFn = SemaRef.ExprError(); 5398 if ((*R.begin())->isCXXClassMember()) 5399 NewFn = SemaRef.BuildPossibleImplicitMemberExpr(SS, R, ExplicitTemplateArgs); 5400 else if (ExplicitTemplateArgs) 5401 NewFn = SemaRef.BuildTemplateIdExpr(SS, R, false, *ExplicitTemplateArgs); 5402 else 5403 NewFn = SemaRef.BuildDeclarationNameExpr(SS, R, false); 5404 5405 if (NewFn.isInvalid()) 5406 return Destroy(SemaRef, Fn, Args, NumArgs); 5407 5408 Fn->Destroy(SemaRef.Context); 5409 5410 // This shouldn't cause an infinite loop because we're giving it 5411 // an expression with non-empty lookup results, which should never 5412 // end up here. 5413 return SemaRef.ActOnCallExpr(/*Scope*/ 0, move(NewFn), LParenLoc, 5414 Sema::MultiExprArg(SemaRef, (void**) Args, NumArgs), 5415 CommaLocs, RParenLoc); 5416} 5417 5418/// ResolveOverloadedCallFn - Given the call expression that calls Fn 5419/// (which eventually refers to the declaration Func) and the call 5420/// arguments Args/NumArgs, attempt to resolve the function call down 5421/// to a specific function. If overload resolution succeeds, returns 5422/// the function declaration produced by overload 5423/// resolution. Otherwise, emits diagnostics, deletes all of the 5424/// arguments and Fn, and returns NULL. 5425Sema::OwningExprResult 5426Sema::BuildOverloadedCallExpr(Expr *Fn, UnresolvedLookupExpr *ULE, 5427 SourceLocation LParenLoc, 5428 Expr **Args, unsigned NumArgs, 5429 SourceLocation *CommaLocs, 5430 SourceLocation RParenLoc) { 5431#ifndef NDEBUG 5432 if (ULE->requiresADL()) { 5433 // To do ADL, we must have found an unqualified name. 5434 assert(!ULE->getQualifier() && "qualified name with ADL"); 5435 5436 // We don't perform ADL for implicit declarations of builtins. 5437 // Verify that this was correctly set up. 5438 FunctionDecl *F; 5439 if (ULE->decls_begin() + 1 == ULE->decls_end() && 5440 (F = dyn_cast<FunctionDecl>(*ULE->decls_begin())) && 5441 F->getBuiltinID() && F->isImplicit()) 5442 assert(0 && "performing ADL for builtin"); 5443 5444 // We don't perform ADL in C. 5445 assert(getLangOptions().CPlusPlus && "ADL enabled in C"); 5446 } 5447#endif 5448 5449 OverloadCandidateSet CandidateSet; 5450 5451 // Add the functions denoted by the callee to the set of candidate 5452 // functions, including those from argument-dependent lookup. 5453 AddOverloadedCallCandidates(ULE, Args, NumArgs, CandidateSet); 5454 5455 // If we found nothing, try to recover. 5456 // AddRecoveryCallCandidates diagnoses the error itself, so we just 5457 // bailout out if it fails. 5458 if (CandidateSet.empty()) 5459 return BuildRecoveryCallExpr(*this, Fn, ULE, LParenLoc, Args, NumArgs, 5460 CommaLocs, RParenLoc); 5461 5462 OverloadCandidateSet::iterator Best; 5463 switch (BestViableFunction(CandidateSet, Fn->getLocStart(), Best)) { 5464 case OR_Success: { 5465 FunctionDecl *FDecl = Best->Function; 5466 CheckUnresolvedLookupAccess(ULE, FDecl, Best->getAccess()); 5467 Fn = FixOverloadedFunctionReference(Fn, FDecl); 5468 return BuildResolvedCallExpr(Fn, FDecl, LParenLoc, Args, NumArgs, RParenLoc); 5469 } 5470 5471 case OR_No_Viable_Function: 5472 Diag(Fn->getSourceRange().getBegin(), 5473 diag::err_ovl_no_viable_function_in_call) 5474 << ULE->getName() << Fn->getSourceRange(); 5475 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 5476 break; 5477 5478 case OR_Ambiguous: 5479 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_ambiguous_call) 5480 << ULE->getName() << Fn->getSourceRange(); 5481 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, NumArgs); 5482 break; 5483 5484 case OR_Deleted: 5485 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_deleted_call) 5486 << Best->Function->isDeleted() 5487 << ULE->getName() 5488 << Fn->getSourceRange(); 5489 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 5490 break; 5491 } 5492 5493 // Overload resolution failed. Destroy all of the subexpressions and 5494 // return NULL. 5495 Fn->Destroy(Context); 5496 for (unsigned Arg = 0; Arg < NumArgs; ++Arg) 5497 Args[Arg]->Destroy(Context); 5498 return ExprError(); 5499} 5500 5501static bool IsOverloaded(const UnresolvedSetImpl &Functions) { 5502 return Functions.size() > 1 || 5503 (Functions.size() == 1 && isa<FunctionTemplateDecl>(*Functions.begin())); 5504} 5505 5506/// \brief Create a unary operation that may resolve to an overloaded 5507/// operator. 5508/// 5509/// \param OpLoc The location of the operator itself (e.g., '*'). 5510/// 5511/// \param OpcIn The UnaryOperator::Opcode that describes this 5512/// operator. 5513/// 5514/// \param Functions The set of non-member functions that will be 5515/// considered by overload resolution. The caller needs to build this 5516/// set based on the context using, e.g., 5517/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 5518/// set should not contain any member functions; those will be added 5519/// by CreateOverloadedUnaryOp(). 5520/// 5521/// \param input The input argument. 5522Sema::OwningExprResult 5523Sema::CreateOverloadedUnaryOp(SourceLocation OpLoc, unsigned OpcIn, 5524 const UnresolvedSetImpl &Fns, 5525 ExprArg input) { 5526 UnaryOperator::Opcode Opc = static_cast<UnaryOperator::Opcode>(OpcIn); 5527 Expr *Input = (Expr *)input.get(); 5528 5529 OverloadedOperatorKind Op = UnaryOperator::getOverloadedOperator(Opc); 5530 assert(Op != OO_None && "Invalid opcode for overloaded unary operator"); 5531 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 5532 5533 Expr *Args[2] = { Input, 0 }; 5534 unsigned NumArgs = 1; 5535 5536 // For post-increment and post-decrement, add the implicit '0' as 5537 // the second argument, so that we know this is a post-increment or 5538 // post-decrement. 5539 if (Opc == UnaryOperator::PostInc || Opc == UnaryOperator::PostDec) { 5540 llvm::APSInt Zero(Context.getTypeSize(Context.IntTy), false); 5541 Args[1] = new (Context) IntegerLiteral(Zero, Context.IntTy, 5542 SourceLocation()); 5543 NumArgs = 2; 5544 } 5545 5546 if (Input->isTypeDependent()) { 5547 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 5548 UnresolvedLookupExpr *Fn 5549 = UnresolvedLookupExpr::Create(Context, /*Dependent*/ true, NamingClass, 5550 0, SourceRange(), OpName, OpLoc, 5551 /*ADL*/ true, IsOverloaded(Fns)); 5552 Fn->addDecls(Fns.begin(), Fns.end()); 5553 5554 input.release(); 5555 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 5556 &Args[0], NumArgs, 5557 Context.DependentTy, 5558 OpLoc)); 5559 } 5560 5561 // Build an empty overload set. 5562 OverloadCandidateSet CandidateSet; 5563 5564 // Add the candidates from the given function set. 5565 AddFunctionCandidates(Fns, &Args[0], NumArgs, CandidateSet, false); 5566 5567 // Add operator candidates that are member functions. 5568 AddMemberOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 5569 5570 // Add candidates from ADL. 5571 AddArgumentDependentLookupCandidates(OpName, /*Operator*/ true, 5572 Args, 1, 5573 /*ExplicitTemplateArgs*/ 0, 5574 CandidateSet); 5575 5576 // Add builtin operator candidates. 5577 AddBuiltinOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 5578 5579 // Perform overload resolution. 5580 OverloadCandidateSet::iterator Best; 5581 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 5582 case OR_Success: { 5583 // We found a built-in operator or an overloaded operator. 5584 FunctionDecl *FnDecl = Best->Function; 5585 5586 if (FnDecl) { 5587 // We matched an overloaded operator. Build a call to that 5588 // operator. 5589 5590 // Convert the arguments. 5591 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 5592 CheckMemberOperatorAccess(OpLoc, Args[0], Method, Best->getAccess()); 5593 5594 if (PerformObjectArgumentInitialization(Input, Method)) 5595 return ExprError(); 5596 } else { 5597 // Convert the arguments. 5598 OwningExprResult InputInit 5599 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 5600 FnDecl->getParamDecl(0)), 5601 SourceLocation(), 5602 move(input)); 5603 if (InputInit.isInvalid()) 5604 return ExprError(); 5605 5606 input = move(InputInit); 5607 Input = (Expr *)input.get(); 5608 } 5609 5610 // Determine the result type 5611 QualType ResultTy = FnDecl->getResultType().getNonReferenceType(); 5612 5613 // Build the actual expression node. 5614 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 5615 SourceLocation()); 5616 UsualUnaryConversions(FnExpr); 5617 5618 input.release(); 5619 Args[0] = Input; 5620 ExprOwningPtr<CallExpr> TheCall(this, 5621 new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 5622 Args, NumArgs, ResultTy, OpLoc)); 5623 5624 if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall.get(), 5625 FnDecl)) 5626 return ExprError(); 5627 5628 return MaybeBindToTemporary(TheCall.release()); 5629 } else { 5630 // We matched a built-in operator. Convert the arguments, then 5631 // break out so that we will build the appropriate built-in 5632 // operator node. 5633 if (PerformImplicitConversion(Input, Best->BuiltinTypes.ParamTypes[0], 5634 Best->Conversions[0], AA_Passing)) 5635 return ExprError(); 5636 5637 break; 5638 } 5639 } 5640 5641 case OR_No_Viable_Function: 5642 // No viable function; fall through to handling this as a 5643 // built-in operator, which will produce an error message for us. 5644 break; 5645 5646 case OR_Ambiguous: 5647 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 5648 << UnaryOperator::getOpcodeStr(Opc) 5649 << Input->getSourceRange(); 5650 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, NumArgs, 5651 UnaryOperator::getOpcodeStr(Opc), OpLoc); 5652 return ExprError(); 5653 5654 case OR_Deleted: 5655 Diag(OpLoc, diag::err_ovl_deleted_oper) 5656 << Best->Function->isDeleted() 5657 << UnaryOperator::getOpcodeStr(Opc) 5658 << Input->getSourceRange(); 5659 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 5660 return ExprError(); 5661 } 5662 5663 // Either we found no viable overloaded operator or we matched a 5664 // built-in operator. In either case, fall through to trying to 5665 // build a built-in operation. 5666 input.release(); 5667 return CreateBuiltinUnaryOp(OpLoc, Opc, Owned(Input)); 5668} 5669 5670/// \brief Create a binary operation that may resolve to an overloaded 5671/// operator. 5672/// 5673/// \param OpLoc The location of the operator itself (e.g., '+'). 5674/// 5675/// \param OpcIn The BinaryOperator::Opcode that describes this 5676/// operator. 5677/// 5678/// \param Functions The set of non-member functions that will be 5679/// considered by overload resolution. The caller needs to build this 5680/// set based on the context using, e.g., 5681/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 5682/// set should not contain any member functions; those will be added 5683/// by CreateOverloadedBinOp(). 5684/// 5685/// \param LHS Left-hand argument. 5686/// \param RHS Right-hand argument. 5687Sema::OwningExprResult 5688Sema::CreateOverloadedBinOp(SourceLocation OpLoc, 5689 unsigned OpcIn, 5690 const UnresolvedSetImpl &Fns, 5691 Expr *LHS, Expr *RHS) { 5692 Expr *Args[2] = { LHS, RHS }; 5693 LHS=RHS=0; //Please use only Args instead of LHS/RHS couple 5694 5695 BinaryOperator::Opcode Opc = static_cast<BinaryOperator::Opcode>(OpcIn); 5696 OverloadedOperatorKind Op = BinaryOperator::getOverloadedOperator(Opc); 5697 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 5698 5699 // If either side is type-dependent, create an appropriate dependent 5700 // expression. 5701 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 5702 if (Fns.empty()) { 5703 // If there are no functions to store, just build a dependent 5704 // BinaryOperator or CompoundAssignment. 5705 if (Opc <= BinaryOperator::Assign || Opc > BinaryOperator::OrAssign) 5706 return Owned(new (Context) BinaryOperator(Args[0], Args[1], Opc, 5707 Context.DependentTy, OpLoc)); 5708 5709 return Owned(new (Context) CompoundAssignOperator(Args[0], Args[1], Opc, 5710 Context.DependentTy, 5711 Context.DependentTy, 5712 Context.DependentTy, 5713 OpLoc)); 5714 } 5715 5716 // FIXME: save results of ADL from here? 5717 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 5718 UnresolvedLookupExpr *Fn 5719 = UnresolvedLookupExpr::Create(Context, /*Dependent*/ true, NamingClass, 5720 0, SourceRange(), OpName, OpLoc, 5721 /*ADL*/ true, IsOverloaded(Fns)); 5722 5723 Fn->addDecls(Fns.begin(), Fns.end()); 5724 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 5725 Args, 2, 5726 Context.DependentTy, 5727 OpLoc)); 5728 } 5729 5730 // If this is the .* operator, which is not overloadable, just 5731 // create a built-in binary operator. 5732 if (Opc == BinaryOperator::PtrMemD) 5733 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 5734 5735 // If this is the assignment operator, we only perform overload resolution 5736 // if the left-hand side is a class or enumeration type. This is actually 5737 // a hack. The standard requires that we do overload resolution between the 5738 // various built-in candidates, but as DR507 points out, this can lead to 5739 // problems. So we do it this way, which pretty much follows what GCC does. 5740 // Note that we go the traditional code path for compound assignment forms. 5741 if (Opc==BinaryOperator::Assign && !Args[0]->getType()->isOverloadableType()) 5742 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 5743 5744 // Build an empty overload set. 5745 OverloadCandidateSet CandidateSet; 5746 5747 // Add the candidates from the given function set. 5748 AddFunctionCandidates(Fns, Args, 2, CandidateSet, false); 5749 5750 // Add operator candidates that are member functions. 5751 AddMemberOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 5752 5753 // Add candidates from ADL. 5754 AddArgumentDependentLookupCandidates(OpName, /*Operator*/ true, 5755 Args, 2, 5756 /*ExplicitTemplateArgs*/ 0, 5757 CandidateSet); 5758 5759 // Add builtin operator candidates. 5760 AddBuiltinOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 5761 5762 // Perform overload resolution. 5763 OverloadCandidateSet::iterator Best; 5764 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 5765 case OR_Success: { 5766 // We found a built-in operator or an overloaded operator. 5767 FunctionDecl *FnDecl = Best->Function; 5768 5769 if (FnDecl) { 5770 // We matched an overloaded operator. Build a call to that 5771 // operator. 5772 5773 // Convert the arguments. 5774 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 5775 // Best->Access is only meaningful for class members. 5776 CheckMemberOperatorAccess(OpLoc, Args[0], Method, Best->getAccess()); 5777 5778 OwningExprResult Arg1 5779 = PerformCopyInitialization( 5780 InitializedEntity::InitializeParameter( 5781 FnDecl->getParamDecl(0)), 5782 SourceLocation(), 5783 Owned(Args[1])); 5784 if (Arg1.isInvalid()) 5785 return ExprError(); 5786 5787 if (PerformObjectArgumentInitialization(Args[0], Method)) 5788 return ExprError(); 5789 5790 Args[1] = RHS = Arg1.takeAs<Expr>(); 5791 } else { 5792 // Convert the arguments. 5793 OwningExprResult Arg0 5794 = PerformCopyInitialization( 5795 InitializedEntity::InitializeParameter( 5796 FnDecl->getParamDecl(0)), 5797 SourceLocation(), 5798 Owned(Args[0])); 5799 if (Arg0.isInvalid()) 5800 return ExprError(); 5801 5802 OwningExprResult Arg1 5803 = PerformCopyInitialization( 5804 InitializedEntity::InitializeParameter( 5805 FnDecl->getParamDecl(1)), 5806 SourceLocation(), 5807 Owned(Args[1])); 5808 if (Arg1.isInvalid()) 5809 return ExprError(); 5810 Args[0] = LHS = Arg0.takeAs<Expr>(); 5811 Args[1] = RHS = Arg1.takeAs<Expr>(); 5812 } 5813 5814 // Determine the result type 5815 QualType ResultTy 5816 = FnDecl->getType()->getAs<FunctionType>()->getResultType(); 5817 ResultTy = ResultTy.getNonReferenceType(); 5818 5819 // Build the actual expression node. 5820 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 5821 OpLoc); 5822 UsualUnaryConversions(FnExpr); 5823 5824 ExprOwningPtr<CXXOperatorCallExpr> 5825 TheCall(this, new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 5826 Args, 2, ResultTy, 5827 OpLoc)); 5828 5829 if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall.get(), 5830 FnDecl)) 5831 return ExprError(); 5832 5833 return MaybeBindToTemporary(TheCall.release()); 5834 } else { 5835 // We matched a built-in operator. Convert the arguments, then 5836 // break out so that we will build the appropriate built-in 5837 // operator node. 5838 if (PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 5839 Best->Conversions[0], AA_Passing) || 5840 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 5841 Best->Conversions[1], AA_Passing)) 5842 return ExprError(); 5843 5844 break; 5845 } 5846 } 5847 5848 case OR_No_Viable_Function: { 5849 // C++ [over.match.oper]p9: 5850 // If the operator is the operator , [...] and there are no 5851 // viable functions, then the operator is assumed to be the 5852 // built-in operator and interpreted according to clause 5. 5853 if (Opc == BinaryOperator::Comma) 5854 break; 5855 5856 // For class as left operand for assignment or compound assigment operator 5857 // do not fall through to handling in built-in, but report that no overloaded 5858 // assignment operator found 5859 OwningExprResult Result = ExprError(); 5860 if (Args[0]->getType()->isRecordType() && 5861 Opc >= BinaryOperator::Assign && Opc <= BinaryOperator::OrAssign) { 5862 Diag(OpLoc, diag::err_ovl_no_viable_oper) 5863 << BinaryOperator::getOpcodeStr(Opc) 5864 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 5865 } else { 5866 // No viable function; try to create a built-in operation, which will 5867 // produce an error. Then, show the non-viable candidates. 5868 Result = CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 5869 } 5870 assert(Result.isInvalid() && 5871 "C++ binary operator overloading is missing candidates!"); 5872 if (Result.isInvalid()) 5873 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2, 5874 BinaryOperator::getOpcodeStr(Opc), OpLoc); 5875 return move(Result); 5876 } 5877 5878 case OR_Ambiguous: 5879 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 5880 << BinaryOperator::getOpcodeStr(Opc) 5881 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 5882 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, 2, 5883 BinaryOperator::getOpcodeStr(Opc), OpLoc); 5884 return ExprError(); 5885 5886 case OR_Deleted: 5887 Diag(OpLoc, diag::err_ovl_deleted_oper) 5888 << Best->Function->isDeleted() 5889 << BinaryOperator::getOpcodeStr(Opc) 5890 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 5891 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2); 5892 return ExprError(); 5893 } 5894 5895 // We matched a built-in operator; build it. 5896 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 5897} 5898 5899Action::OwningExprResult 5900Sema::CreateOverloadedArraySubscriptExpr(SourceLocation LLoc, 5901 SourceLocation RLoc, 5902 ExprArg Base, ExprArg Idx) { 5903 Expr *Args[2] = { static_cast<Expr*>(Base.get()), 5904 static_cast<Expr*>(Idx.get()) }; 5905 DeclarationName OpName = 5906 Context.DeclarationNames.getCXXOperatorName(OO_Subscript); 5907 5908 // If either side is type-dependent, create an appropriate dependent 5909 // expression. 5910 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 5911 5912 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 5913 UnresolvedLookupExpr *Fn 5914 = UnresolvedLookupExpr::Create(Context, /*Dependent*/ true, NamingClass, 5915 0, SourceRange(), OpName, LLoc, 5916 /*ADL*/ true, /*Overloaded*/ false); 5917 // Can't add any actual overloads yet 5918 5919 Base.release(); 5920 Idx.release(); 5921 return Owned(new (Context) CXXOperatorCallExpr(Context, OO_Subscript, Fn, 5922 Args, 2, 5923 Context.DependentTy, 5924 RLoc)); 5925 } 5926 5927 // Build an empty overload set. 5928 OverloadCandidateSet CandidateSet; 5929 5930 // Subscript can only be overloaded as a member function. 5931 5932 // Add operator candidates that are member functions. 5933 AddMemberOperatorCandidates(OO_Subscript, LLoc, Args, 2, CandidateSet); 5934 5935 // Add builtin operator candidates. 5936 AddBuiltinOperatorCandidates(OO_Subscript, LLoc, Args, 2, CandidateSet); 5937 5938 // Perform overload resolution. 5939 OverloadCandidateSet::iterator Best; 5940 switch (BestViableFunction(CandidateSet, LLoc, Best)) { 5941 case OR_Success: { 5942 // We found a built-in operator or an overloaded operator. 5943 FunctionDecl *FnDecl = Best->Function; 5944 5945 if (FnDecl) { 5946 // We matched an overloaded operator. Build a call to that 5947 // operator. 5948 5949 CheckMemberOperatorAccess(LLoc, Args[0], FnDecl, Best->getAccess()); 5950 5951 // Convert the arguments. 5952 CXXMethodDecl *Method = cast<CXXMethodDecl>(FnDecl); 5953 if (PerformObjectArgumentInitialization(Args[0], Method)) 5954 return ExprError(); 5955 5956 // Convert the arguments. 5957 OwningExprResult InputInit 5958 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 5959 FnDecl->getParamDecl(0)), 5960 SourceLocation(), 5961 Owned(Args[1])); 5962 if (InputInit.isInvalid()) 5963 return ExprError(); 5964 5965 Args[1] = InputInit.takeAs<Expr>(); 5966 5967 // Determine the result type 5968 QualType ResultTy 5969 = FnDecl->getType()->getAs<FunctionType>()->getResultType(); 5970 ResultTy = ResultTy.getNonReferenceType(); 5971 5972 // Build the actual expression node. 5973 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 5974 LLoc); 5975 UsualUnaryConversions(FnExpr); 5976 5977 Base.release(); 5978 Idx.release(); 5979 ExprOwningPtr<CXXOperatorCallExpr> 5980 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Subscript, 5981 FnExpr, Args, 2, 5982 ResultTy, RLoc)); 5983 5984 if (CheckCallReturnType(FnDecl->getResultType(), LLoc, TheCall.get(), 5985 FnDecl)) 5986 return ExprError(); 5987 5988 return MaybeBindToTemporary(TheCall.release()); 5989 } else { 5990 // We matched a built-in operator. Convert the arguments, then 5991 // break out so that we will build the appropriate built-in 5992 // operator node. 5993 if (PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 5994 Best->Conversions[0], AA_Passing) || 5995 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 5996 Best->Conversions[1], AA_Passing)) 5997 return ExprError(); 5998 5999 break; 6000 } 6001 } 6002 6003 case OR_No_Viable_Function: { 6004 if (CandidateSet.empty()) 6005 Diag(LLoc, diag::err_ovl_no_oper) 6006 << Args[0]->getType() << /*subscript*/ 0 6007 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 6008 else 6009 Diag(LLoc, diag::err_ovl_no_viable_subscript) 6010 << Args[0]->getType() 6011 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 6012 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2, 6013 "[]", LLoc); 6014 return ExprError(); 6015 } 6016 6017 case OR_Ambiguous: 6018 Diag(LLoc, diag::err_ovl_ambiguous_oper) 6019 << "[]" << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 6020 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, 2, 6021 "[]", LLoc); 6022 return ExprError(); 6023 6024 case OR_Deleted: 6025 Diag(LLoc, diag::err_ovl_deleted_oper) 6026 << Best->Function->isDeleted() << "[]" 6027 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 6028 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2, 6029 "[]", LLoc); 6030 return ExprError(); 6031 } 6032 6033 // We matched a built-in operator; build it. 6034 Base.release(); 6035 Idx.release(); 6036 return CreateBuiltinArraySubscriptExpr(Owned(Args[0]), LLoc, 6037 Owned(Args[1]), RLoc); 6038} 6039 6040/// BuildCallToMemberFunction - Build a call to a member 6041/// function. MemExpr is the expression that refers to the member 6042/// function (and includes the object parameter), Args/NumArgs are the 6043/// arguments to the function call (not including the object 6044/// parameter). The caller needs to validate that the member 6045/// expression refers to a member function or an overloaded member 6046/// function. 6047Sema::OwningExprResult 6048Sema::BuildCallToMemberFunction(Scope *S, Expr *MemExprE, 6049 SourceLocation LParenLoc, Expr **Args, 6050 unsigned NumArgs, SourceLocation *CommaLocs, 6051 SourceLocation RParenLoc) { 6052 // Dig out the member expression. This holds both the object 6053 // argument and the member function we're referring to. 6054 Expr *NakedMemExpr = MemExprE->IgnoreParens(); 6055 6056 MemberExpr *MemExpr; 6057 CXXMethodDecl *Method = 0; 6058 if (isa<MemberExpr>(NakedMemExpr)) { 6059 MemExpr = cast<MemberExpr>(NakedMemExpr); 6060 Method = cast<CXXMethodDecl>(MemExpr->getMemberDecl()); 6061 } else { 6062 UnresolvedMemberExpr *UnresExpr = cast<UnresolvedMemberExpr>(NakedMemExpr); 6063 6064 QualType ObjectType = UnresExpr->getBaseType(); 6065 6066 // Add overload candidates 6067 OverloadCandidateSet CandidateSet; 6068 6069 // FIXME: avoid copy. 6070 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 6071 if (UnresExpr->hasExplicitTemplateArgs()) { 6072 UnresExpr->copyTemplateArgumentsInto(TemplateArgsBuffer); 6073 TemplateArgs = &TemplateArgsBuffer; 6074 } 6075 6076 for (UnresolvedMemberExpr::decls_iterator I = UnresExpr->decls_begin(), 6077 E = UnresExpr->decls_end(); I != E; ++I) { 6078 6079 NamedDecl *Func = *I; 6080 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(Func->getDeclContext()); 6081 if (isa<UsingShadowDecl>(Func)) 6082 Func = cast<UsingShadowDecl>(Func)->getTargetDecl(); 6083 6084 if ((Method = dyn_cast<CXXMethodDecl>(Func))) { 6085 // If explicit template arguments were provided, we can't call a 6086 // non-template member function. 6087 if (TemplateArgs) 6088 continue; 6089 6090 AddMethodCandidate(Method, I.getAccess(), ActingDC, ObjectType, 6091 Args, NumArgs, 6092 CandidateSet, /*SuppressUserConversions=*/false); 6093 } else { 6094 AddMethodTemplateCandidate(cast<FunctionTemplateDecl>(Func), 6095 I.getAccess(), ActingDC, TemplateArgs, 6096 ObjectType, Args, NumArgs, 6097 CandidateSet, 6098 /*SuppressUsedConversions=*/false); 6099 } 6100 } 6101 6102 DeclarationName DeclName = UnresExpr->getMemberName(); 6103 6104 OverloadCandidateSet::iterator Best; 6105 switch (BestViableFunction(CandidateSet, UnresExpr->getLocStart(), Best)) { 6106 case OR_Success: 6107 Method = cast<CXXMethodDecl>(Best->Function); 6108 CheckUnresolvedMemberAccess(UnresExpr, Method, Best->getAccess()); 6109 break; 6110 6111 case OR_No_Viable_Function: 6112 Diag(UnresExpr->getMemberLoc(), 6113 diag::err_ovl_no_viable_member_function_in_call) 6114 << DeclName << MemExprE->getSourceRange(); 6115 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6116 // FIXME: Leaking incoming expressions! 6117 return ExprError(); 6118 6119 case OR_Ambiguous: 6120 Diag(UnresExpr->getMemberLoc(), diag::err_ovl_ambiguous_member_call) 6121 << DeclName << MemExprE->getSourceRange(); 6122 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6123 // FIXME: Leaking incoming expressions! 6124 return ExprError(); 6125 6126 case OR_Deleted: 6127 Diag(UnresExpr->getMemberLoc(), diag::err_ovl_deleted_member_call) 6128 << Best->Function->isDeleted() 6129 << DeclName << MemExprE->getSourceRange(); 6130 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6131 // FIXME: Leaking incoming expressions! 6132 return ExprError(); 6133 } 6134 6135 MemExprE = FixOverloadedFunctionReference(MemExprE, Method); 6136 6137 // If overload resolution picked a static member, build a 6138 // non-member call based on that function. 6139 if (Method->isStatic()) { 6140 return BuildResolvedCallExpr(MemExprE, Method, LParenLoc, 6141 Args, NumArgs, RParenLoc); 6142 } 6143 6144 MemExpr = cast<MemberExpr>(MemExprE->IgnoreParens()); 6145 } 6146 6147 assert(Method && "Member call to something that isn't a method?"); 6148 ExprOwningPtr<CXXMemberCallExpr> 6149 TheCall(this, new (Context) CXXMemberCallExpr(Context, MemExprE, Args, 6150 NumArgs, 6151 Method->getResultType().getNonReferenceType(), 6152 RParenLoc)); 6153 6154 // Check for a valid return type. 6155 if (CheckCallReturnType(Method->getResultType(), MemExpr->getMemberLoc(), 6156 TheCall.get(), Method)) 6157 return ExprError(); 6158 6159 // Convert the object argument (for a non-static member function call). 6160 Expr *ObjectArg = MemExpr->getBase(); 6161 if (!Method->isStatic() && 6162 PerformObjectArgumentInitialization(ObjectArg, Method)) 6163 return ExprError(); 6164 MemExpr->setBase(ObjectArg); 6165 6166 // Convert the rest of the arguments 6167 const FunctionProtoType *Proto = cast<FunctionProtoType>(Method->getType()); 6168 if (ConvertArgumentsForCall(&*TheCall, MemExpr, Method, Proto, Args, NumArgs, 6169 RParenLoc)) 6170 return ExprError(); 6171 6172 if (CheckFunctionCall(Method, TheCall.get())) 6173 return ExprError(); 6174 6175 return MaybeBindToTemporary(TheCall.release()); 6176} 6177 6178/// BuildCallToObjectOfClassType - Build a call to an object of class 6179/// type (C++ [over.call.object]), which can end up invoking an 6180/// overloaded function call operator (@c operator()) or performing a 6181/// user-defined conversion on the object argument. 6182Sema::ExprResult 6183Sema::BuildCallToObjectOfClassType(Scope *S, Expr *Object, 6184 SourceLocation LParenLoc, 6185 Expr **Args, unsigned NumArgs, 6186 SourceLocation *CommaLocs, 6187 SourceLocation RParenLoc) { 6188 assert(Object->getType()->isRecordType() && "Requires object type argument"); 6189 const RecordType *Record = Object->getType()->getAs<RecordType>(); 6190 6191 // C++ [over.call.object]p1: 6192 // If the primary-expression E in the function call syntax 6193 // evaluates to a class object of type "cv T", then the set of 6194 // candidate functions includes at least the function call 6195 // operators of T. The function call operators of T are obtained by 6196 // ordinary lookup of the name operator() in the context of 6197 // (E).operator(). 6198 OverloadCandidateSet CandidateSet; 6199 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Call); 6200 6201 if (RequireCompleteType(LParenLoc, Object->getType(), 6202 PartialDiagnostic(diag::err_incomplete_object_call) 6203 << Object->getSourceRange())) 6204 return true; 6205 6206 LookupResult R(*this, OpName, LParenLoc, LookupOrdinaryName); 6207 LookupQualifiedName(R, Record->getDecl()); 6208 R.suppressDiagnostics(); 6209 6210 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 6211 Oper != OperEnd; ++Oper) { 6212 AddMethodCandidate(*Oper, Oper.getAccess(), Object->getType(), 6213 Args, NumArgs, CandidateSet, 6214 /*SuppressUserConversions=*/ false); 6215 } 6216 6217 // C++ [over.call.object]p2: 6218 // In addition, for each conversion function declared in T of the 6219 // form 6220 // 6221 // operator conversion-type-id () cv-qualifier; 6222 // 6223 // where cv-qualifier is the same cv-qualification as, or a 6224 // greater cv-qualification than, cv, and where conversion-type-id 6225 // denotes the type "pointer to function of (P1,...,Pn) returning 6226 // R", or the type "reference to pointer to function of 6227 // (P1,...,Pn) returning R", or the type "reference to function 6228 // of (P1,...,Pn) returning R", a surrogate call function [...] 6229 // is also considered as a candidate function. Similarly, 6230 // surrogate call functions are added to the set of candidate 6231 // functions for each conversion function declared in an 6232 // accessible base class provided the function is not hidden 6233 // within T by another intervening declaration. 6234 const UnresolvedSetImpl *Conversions 6235 = cast<CXXRecordDecl>(Record->getDecl())->getVisibleConversionFunctions(); 6236 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 6237 E = Conversions->end(); I != E; ++I) { 6238 NamedDecl *D = *I; 6239 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext()); 6240 if (isa<UsingShadowDecl>(D)) 6241 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 6242 6243 // Skip over templated conversion functions; they aren't 6244 // surrogates. 6245 if (isa<FunctionTemplateDecl>(D)) 6246 continue; 6247 6248 CXXConversionDecl *Conv = cast<CXXConversionDecl>(D); 6249 6250 // Strip the reference type (if any) and then the pointer type (if 6251 // any) to get down to what might be a function type. 6252 QualType ConvType = Conv->getConversionType().getNonReferenceType(); 6253 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 6254 ConvType = ConvPtrType->getPointeeType(); 6255 6256 if (const FunctionProtoType *Proto = ConvType->getAs<FunctionProtoType>()) 6257 AddSurrogateCandidate(Conv, I.getAccess(), ActingContext, Proto, 6258 Object->getType(), Args, NumArgs, 6259 CandidateSet); 6260 } 6261 6262 // Perform overload resolution. 6263 OverloadCandidateSet::iterator Best; 6264 switch (BestViableFunction(CandidateSet, Object->getLocStart(), Best)) { 6265 case OR_Success: 6266 // Overload resolution succeeded; we'll build the appropriate call 6267 // below. 6268 break; 6269 6270 case OR_No_Viable_Function: 6271 if (CandidateSet.empty()) 6272 Diag(Object->getSourceRange().getBegin(), diag::err_ovl_no_oper) 6273 << Object->getType() << /*call*/ 1 6274 << Object->getSourceRange(); 6275 else 6276 Diag(Object->getSourceRange().getBegin(), 6277 diag::err_ovl_no_viable_object_call) 6278 << Object->getType() << Object->getSourceRange(); 6279 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6280 break; 6281 6282 case OR_Ambiguous: 6283 Diag(Object->getSourceRange().getBegin(), 6284 diag::err_ovl_ambiguous_object_call) 6285 << Object->getType() << Object->getSourceRange(); 6286 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, NumArgs); 6287 break; 6288 6289 case OR_Deleted: 6290 Diag(Object->getSourceRange().getBegin(), 6291 diag::err_ovl_deleted_object_call) 6292 << Best->Function->isDeleted() 6293 << Object->getType() << Object->getSourceRange(); 6294 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6295 break; 6296 } 6297 6298 if (Best == CandidateSet.end()) { 6299 // We had an error; delete all of the subexpressions and return 6300 // the error. 6301 Object->Destroy(Context); 6302 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 6303 Args[ArgIdx]->Destroy(Context); 6304 return true; 6305 } 6306 6307 if (Best->Function == 0) { 6308 // Since there is no function declaration, this is one of the 6309 // surrogate candidates. Dig out the conversion function. 6310 CXXConversionDecl *Conv 6311 = cast<CXXConversionDecl>( 6312 Best->Conversions[0].UserDefined.ConversionFunction); 6313 6314 CheckMemberOperatorAccess(LParenLoc, Object, Conv, Best->getAccess()); 6315 6316 // We selected one of the surrogate functions that converts the 6317 // object parameter to a function pointer. Perform the conversion 6318 // on the object argument, then let ActOnCallExpr finish the job. 6319 6320 // Create an implicit member expr to refer to the conversion operator. 6321 // and then call it. 6322 CXXMemberCallExpr *CE = BuildCXXMemberCallExpr(Object, Conv); 6323 6324 return ActOnCallExpr(S, ExprArg(*this, CE), LParenLoc, 6325 MultiExprArg(*this, (ExprTy**)Args, NumArgs), 6326 CommaLocs, RParenLoc).release(); 6327 } 6328 6329 CheckMemberOperatorAccess(LParenLoc, Object, 6330 Best->Function, Best->getAccess()); 6331 6332 // We found an overloaded operator(). Build a CXXOperatorCallExpr 6333 // that calls this method, using Object for the implicit object 6334 // parameter and passing along the remaining arguments. 6335 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 6336 const FunctionProtoType *Proto = Method->getType()->getAs<FunctionProtoType>(); 6337 6338 unsigned NumArgsInProto = Proto->getNumArgs(); 6339 unsigned NumArgsToCheck = NumArgs; 6340 6341 // Build the full argument list for the method call (the 6342 // implicit object parameter is placed at the beginning of the 6343 // list). 6344 Expr **MethodArgs; 6345 if (NumArgs < NumArgsInProto) { 6346 NumArgsToCheck = NumArgsInProto; 6347 MethodArgs = new Expr*[NumArgsInProto + 1]; 6348 } else { 6349 MethodArgs = new Expr*[NumArgs + 1]; 6350 } 6351 MethodArgs[0] = Object; 6352 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 6353 MethodArgs[ArgIdx + 1] = Args[ArgIdx]; 6354 6355 Expr *NewFn = new (Context) DeclRefExpr(Method, Method->getType(), 6356 SourceLocation()); 6357 UsualUnaryConversions(NewFn); 6358 6359 // Once we've built TheCall, all of the expressions are properly 6360 // owned. 6361 QualType ResultTy = Method->getResultType().getNonReferenceType(); 6362 ExprOwningPtr<CXXOperatorCallExpr> 6363 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Call, NewFn, 6364 MethodArgs, NumArgs + 1, 6365 ResultTy, RParenLoc)); 6366 delete [] MethodArgs; 6367 6368 if (CheckCallReturnType(Method->getResultType(), LParenLoc, TheCall.get(), 6369 Method)) 6370 return true; 6371 6372 // We may have default arguments. If so, we need to allocate more 6373 // slots in the call for them. 6374 if (NumArgs < NumArgsInProto) 6375 TheCall->setNumArgs(Context, NumArgsInProto + 1); 6376 else if (NumArgs > NumArgsInProto) 6377 NumArgsToCheck = NumArgsInProto; 6378 6379 bool IsError = false; 6380 6381 // Initialize the implicit object parameter. 6382 IsError |= PerformObjectArgumentInitialization(Object, Method); 6383 TheCall->setArg(0, Object); 6384 6385 6386 // Check the argument types. 6387 for (unsigned i = 0; i != NumArgsToCheck; i++) { 6388 Expr *Arg; 6389 if (i < NumArgs) { 6390 Arg = Args[i]; 6391 6392 // Pass the argument. 6393 6394 OwningExprResult InputInit 6395 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 6396 Method->getParamDecl(i)), 6397 SourceLocation(), Owned(Arg)); 6398 6399 IsError |= InputInit.isInvalid(); 6400 Arg = InputInit.takeAs<Expr>(); 6401 } else { 6402 OwningExprResult DefArg 6403 = BuildCXXDefaultArgExpr(LParenLoc, Method, Method->getParamDecl(i)); 6404 if (DefArg.isInvalid()) { 6405 IsError = true; 6406 break; 6407 } 6408 6409 Arg = DefArg.takeAs<Expr>(); 6410 } 6411 6412 TheCall->setArg(i + 1, Arg); 6413 } 6414 6415 // If this is a variadic call, handle args passed through "...". 6416 if (Proto->isVariadic()) { 6417 // Promote the arguments (C99 6.5.2.2p7). 6418 for (unsigned i = NumArgsInProto; i != NumArgs; i++) { 6419 Expr *Arg = Args[i]; 6420 IsError |= DefaultVariadicArgumentPromotion(Arg, VariadicMethod); 6421 TheCall->setArg(i + 1, Arg); 6422 } 6423 } 6424 6425 if (IsError) return true; 6426 6427 if (CheckFunctionCall(Method, TheCall.get())) 6428 return true; 6429 6430 return MaybeBindToTemporary(TheCall.release()).release(); 6431} 6432 6433/// BuildOverloadedArrowExpr - Build a call to an overloaded @c operator-> 6434/// (if one exists), where @c Base is an expression of class type and 6435/// @c Member is the name of the member we're trying to find. 6436Sema::OwningExprResult 6437Sema::BuildOverloadedArrowExpr(Scope *S, ExprArg BaseIn, SourceLocation OpLoc) { 6438 Expr *Base = static_cast<Expr *>(BaseIn.get()); 6439 assert(Base->getType()->isRecordType() && "left-hand side must have class type"); 6440 6441 // C++ [over.ref]p1: 6442 // 6443 // [...] An expression x->m is interpreted as (x.operator->())->m 6444 // for a class object x of type T if T::operator->() exists and if 6445 // the operator is selected as the best match function by the 6446 // overload resolution mechanism (13.3). 6447 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Arrow); 6448 OverloadCandidateSet CandidateSet; 6449 const RecordType *BaseRecord = Base->getType()->getAs<RecordType>(); 6450 6451 if (RequireCompleteType(Base->getLocStart(), Base->getType(), 6452 PDiag(diag::err_typecheck_incomplete_tag) 6453 << Base->getSourceRange())) 6454 return ExprError(); 6455 6456 LookupResult R(*this, OpName, OpLoc, LookupOrdinaryName); 6457 LookupQualifiedName(R, BaseRecord->getDecl()); 6458 R.suppressDiagnostics(); 6459 6460 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 6461 Oper != OperEnd; ++Oper) { 6462 NamedDecl *D = *Oper; 6463 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext()); 6464 if (isa<UsingShadowDecl>(D)) 6465 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 6466 6467 AddMethodCandidate(cast<CXXMethodDecl>(D), Oper.getAccess(), ActingContext, 6468 Base->getType(), 0, 0, CandidateSet, 6469 /*SuppressUserConversions=*/false); 6470 } 6471 6472 // Perform overload resolution. 6473 OverloadCandidateSet::iterator Best; 6474 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 6475 case OR_Success: 6476 // Overload resolution succeeded; we'll build the call below. 6477 break; 6478 6479 case OR_No_Viable_Function: 6480 if (CandidateSet.empty()) 6481 Diag(OpLoc, diag::err_typecheck_member_reference_arrow) 6482 << Base->getType() << Base->getSourceRange(); 6483 else 6484 Diag(OpLoc, diag::err_ovl_no_viable_oper) 6485 << "operator->" << Base->getSourceRange(); 6486 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, &Base, 1); 6487 return ExprError(); 6488 6489 case OR_Ambiguous: 6490 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 6491 << "->" << Base->getSourceRange(); 6492 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, &Base, 1); 6493 return ExprError(); 6494 6495 case OR_Deleted: 6496 Diag(OpLoc, diag::err_ovl_deleted_oper) 6497 << Best->Function->isDeleted() 6498 << "->" << Base->getSourceRange(); 6499 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, &Base, 1); 6500 return ExprError(); 6501 } 6502 6503 // Convert the object parameter. 6504 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 6505 if (PerformObjectArgumentInitialization(Base, Method)) 6506 return ExprError(); 6507 6508 // No concerns about early exits now. 6509 BaseIn.release(); 6510 6511 // Build the operator call. 6512 Expr *FnExpr = new (Context) DeclRefExpr(Method, Method->getType(), 6513 SourceLocation()); 6514 UsualUnaryConversions(FnExpr); 6515 6516 QualType ResultTy = Method->getResultType().getNonReferenceType(); 6517 ExprOwningPtr<CXXOperatorCallExpr> 6518 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Arrow, FnExpr, 6519 &Base, 1, ResultTy, OpLoc)); 6520 6521 if (CheckCallReturnType(Method->getResultType(), OpLoc, TheCall.get(), 6522 Method)) 6523 return ExprError(); 6524 return move(TheCall); 6525} 6526 6527/// FixOverloadedFunctionReference - E is an expression that refers to 6528/// a C++ overloaded function (possibly with some parentheses and 6529/// perhaps a '&' around it). We have resolved the overloaded function 6530/// to the function declaration Fn, so patch up the expression E to 6531/// refer (possibly indirectly) to Fn. Returns the new expr. 6532Expr *Sema::FixOverloadedFunctionReference(Expr *E, FunctionDecl *Fn) { 6533 if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) { 6534 Expr *SubExpr = FixOverloadedFunctionReference(PE->getSubExpr(), Fn); 6535 if (SubExpr == PE->getSubExpr()) 6536 return PE->Retain(); 6537 6538 return new (Context) ParenExpr(PE->getLParen(), PE->getRParen(), SubExpr); 6539 } 6540 6541 if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) { 6542 Expr *SubExpr = FixOverloadedFunctionReference(ICE->getSubExpr(), Fn); 6543 assert(Context.hasSameType(ICE->getSubExpr()->getType(), 6544 SubExpr->getType()) && 6545 "Implicit cast type cannot be determined from overload"); 6546 if (SubExpr == ICE->getSubExpr()) 6547 return ICE->Retain(); 6548 6549 return new (Context) ImplicitCastExpr(ICE->getType(), 6550 ICE->getCastKind(), 6551 SubExpr, 6552 ICE->isLvalueCast()); 6553 } 6554 6555 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(E)) { 6556 assert(UnOp->getOpcode() == UnaryOperator::AddrOf && 6557 "Can only take the address of an overloaded function"); 6558 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 6559 if (Method->isStatic()) { 6560 // Do nothing: static member functions aren't any different 6561 // from non-member functions. 6562 } else { 6563 // Fix the sub expression, which really has to be an 6564 // UnresolvedLookupExpr holding an overloaded member function 6565 // or template. 6566 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(), Fn); 6567 if (SubExpr == UnOp->getSubExpr()) 6568 return UnOp->Retain(); 6569 6570 assert(isa<DeclRefExpr>(SubExpr) 6571 && "fixed to something other than a decl ref"); 6572 assert(cast<DeclRefExpr>(SubExpr)->getQualifier() 6573 && "fixed to a member ref with no nested name qualifier"); 6574 6575 // We have taken the address of a pointer to member 6576 // function. Perform the computation here so that we get the 6577 // appropriate pointer to member type. 6578 QualType ClassType 6579 = Context.getTypeDeclType(cast<RecordDecl>(Method->getDeclContext())); 6580 QualType MemPtrType 6581 = Context.getMemberPointerType(Fn->getType(), ClassType.getTypePtr()); 6582 6583 return new (Context) UnaryOperator(SubExpr, UnaryOperator::AddrOf, 6584 MemPtrType, UnOp->getOperatorLoc()); 6585 } 6586 } 6587 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(), Fn); 6588 if (SubExpr == UnOp->getSubExpr()) 6589 return UnOp->Retain(); 6590 6591 return new (Context) UnaryOperator(SubExpr, UnaryOperator::AddrOf, 6592 Context.getPointerType(SubExpr->getType()), 6593 UnOp->getOperatorLoc()); 6594 } 6595 6596 if (UnresolvedLookupExpr *ULE = dyn_cast<UnresolvedLookupExpr>(E)) { 6597 // FIXME: avoid copy. 6598 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 6599 if (ULE->hasExplicitTemplateArgs()) { 6600 ULE->copyTemplateArgumentsInto(TemplateArgsBuffer); 6601 TemplateArgs = &TemplateArgsBuffer; 6602 } 6603 6604 return DeclRefExpr::Create(Context, 6605 ULE->getQualifier(), 6606 ULE->getQualifierRange(), 6607 Fn, 6608 ULE->getNameLoc(), 6609 Fn->getType(), 6610 TemplateArgs); 6611 } 6612 6613 if (UnresolvedMemberExpr *MemExpr = dyn_cast<UnresolvedMemberExpr>(E)) { 6614 // FIXME: avoid copy. 6615 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 6616 if (MemExpr->hasExplicitTemplateArgs()) { 6617 MemExpr->copyTemplateArgumentsInto(TemplateArgsBuffer); 6618 TemplateArgs = &TemplateArgsBuffer; 6619 } 6620 6621 Expr *Base; 6622 6623 // If we're filling in 6624 if (MemExpr->isImplicitAccess()) { 6625 if (cast<CXXMethodDecl>(Fn)->isStatic()) { 6626 return DeclRefExpr::Create(Context, 6627 MemExpr->getQualifier(), 6628 MemExpr->getQualifierRange(), 6629 Fn, 6630 MemExpr->getMemberLoc(), 6631 Fn->getType(), 6632 TemplateArgs); 6633 } else { 6634 SourceLocation Loc = MemExpr->getMemberLoc(); 6635 if (MemExpr->getQualifier()) 6636 Loc = MemExpr->getQualifierRange().getBegin(); 6637 Base = new (Context) CXXThisExpr(Loc, 6638 MemExpr->getBaseType(), 6639 /*isImplicit=*/true); 6640 } 6641 } else 6642 Base = MemExpr->getBase()->Retain(); 6643 6644 return MemberExpr::Create(Context, Base, 6645 MemExpr->isArrow(), 6646 MemExpr->getQualifier(), 6647 MemExpr->getQualifierRange(), 6648 Fn, 6649 MemExpr->getMemberLoc(), 6650 TemplateArgs, 6651 Fn->getType()); 6652 } 6653 6654 assert(false && "Invalid reference to overloaded function"); 6655 return E->Retain(); 6656} 6657 6658Sema::OwningExprResult Sema::FixOverloadedFunctionReference(OwningExprResult E, 6659 FunctionDecl *Fn) { 6660 return Owned(FixOverloadedFunctionReference((Expr *)E.get(), Fn)); 6661} 6662 6663} // end namespace clang 6664