SemaOverload.cpp revision 6b2accb4793e16b2e93a8c2589f5df702231f17a
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 if (IsStandardConversion(From, ToType, InOverloadResolution, ICS.Standard)) { 451 ICS.setStandard(); 452 return ICS; 453 } 454 455 if (!getLangOptions().CPlusPlus) { 456 ICS.setBad(); 457 ICS.Bad.init(BadConversionSequence::no_conversion, From, ToType); 458 return ICS; 459 } 460 461 OverloadCandidateSet Conversions(From->getExprLoc()); 462 OverloadingResult UserDefResult 463 = IsUserDefinedConversion(From, ToType, ICS.UserDefined, Conversions, 464 !SuppressUserConversions, AllowExplicit, 465 ForceRValue, UserCast); 466 467 if (UserDefResult == OR_Success) { 468 ICS.setUserDefined(); 469 // C++ [over.ics.user]p4: 470 // A conversion of an expression of class type to the same class 471 // type is given Exact Match rank, and a conversion of an 472 // expression of class type to a base class of that type is 473 // given Conversion rank, in spite of the fact that a copy 474 // constructor (i.e., a user-defined conversion function) is 475 // called for those cases. 476 if (CXXConstructorDecl *Constructor 477 = dyn_cast<CXXConstructorDecl>(ICS.UserDefined.ConversionFunction)) { 478 QualType FromCanon 479 = Context.getCanonicalType(From->getType().getUnqualifiedType()); 480 QualType ToCanon = Context.getCanonicalType(ToType).getUnqualifiedType(); 481 if (Constructor->isCopyConstructor() && 482 (FromCanon == ToCanon || IsDerivedFrom(FromCanon, ToCanon))) { 483 // Turn this into a "standard" conversion sequence, so that it 484 // gets ranked with standard conversion sequences. 485 ICS.setStandard(); 486 ICS.Standard.setAsIdentityConversion(); 487 ICS.Standard.setFromType(From->getType()); 488 ICS.Standard.setAllToTypes(ToType); 489 ICS.Standard.CopyConstructor = Constructor; 490 if (ToCanon != FromCanon) 491 ICS.Standard.Second = ICK_Derived_To_Base; 492 } 493 } 494 495 // C++ [over.best.ics]p4: 496 // However, when considering the argument of a user-defined 497 // conversion function that is a candidate by 13.3.1.3 when 498 // invoked for the copying of the temporary in the second step 499 // of a class copy-initialization, or by 13.3.1.4, 13.3.1.5, or 500 // 13.3.1.6 in all cases, only standard conversion sequences and 501 // ellipsis conversion sequences are allowed. 502 if (SuppressUserConversions && ICS.isUserDefined()) { 503 ICS.setBad(); 504 ICS.Bad.init(BadConversionSequence::suppressed_user, From, ToType); 505 } 506 } else if (UserDefResult == OR_Ambiguous && !SuppressUserConversions) { 507 ICS.setAmbiguous(); 508 ICS.Ambiguous.setFromType(From->getType()); 509 ICS.Ambiguous.setToType(ToType); 510 for (OverloadCandidateSet::iterator Cand = Conversions.begin(); 511 Cand != Conversions.end(); ++Cand) 512 if (Cand->Viable) 513 ICS.Ambiguous.addConversion(Cand->Function); 514 } else { 515 ICS.setBad(); 516 ICS.Bad.init(BadConversionSequence::no_conversion, From, ToType); 517 } 518 519 return ICS; 520} 521 522/// \brief Determine whether the conversion from FromType to ToType is a valid 523/// conversion that strips "noreturn" off the nested function type. 524static bool IsNoReturnConversion(ASTContext &Context, QualType FromType, 525 QualType ToType, QualType &ResultTy) { 526 if (Context.hasSameUnqualifiedType(FromType, ToType)) 527 return false; 528 529 // Strip the noreturn off the type we're converting from; noreturn can 530 // safely be removed. 531 FromType = Context.getNoReturnType(FromType, false); 532 if (!Context.hasSameUnqualifiedType(FromType, ToType)) 533 return false; 534 535 ResultTy = FromType; 536 return true; 537} 538 539/// IsStandardConversion - Determines whether there is a standard 540/// conversion sequence (C++ [conv], C++ [over.ics.scs]) from the 541/// expression From to the type ToType. Standard conversion sequences 542/// only consider non-class types; for conversions that involve class 543/// types, use TryImplicitConversion. If a conversion exists, SCS will 544/// contain the standard conversion sequence required to perform this 545/// conversion and this routine will return true. Otherwise, this 546/// routine will return false and the value of SCS is unspecified. 547bool 548Sema::IsStandardConversion(Expr* From, QualType ToType, 549 bool InOverloadResolution, 550 StandardConversionSequence &SCS) { 551 QualType FromType = From->getType(); 552 553 // Standard conversions (C++ [conv]) 554 SCS.setAsIdentityConversion(); 555 SCS.Deprecated = false; 556 SCS.IncompatibleObjC = false; 557 SCS.setFromType(FromType); 558 SCS.CopyConstructor = 0; 559 560 // There are no standard conversions for class types in C++, so 561 // abort early. When overloading in C, however, we do permit 562 if (FromType->isRecordType() || ToType->isRecordType()) { 563 if (getLangOptions().CPlusPlus) 564 return false; 565 566 // When we're overloading in C, we allow, as standard conversions, 567 } 568 569 // The first conversion can be an lvalue-to-rvalue conversion, 570 // array-to-pointer conversion, or function-to-pointer conversion 571 // (C++ 4p1). 572 573 // Lvalue-to-rvalue conversion (C++ 4.1): 574 // An lvalue (3.10) of a non-function, non-array type T can be 575 // converted to an rvalue. 576 Expr::isLvalueResult argIsLvalue = From->isLvalue(Context); 577 if (argIsLvalue == Expr::LV_Valid && 578 !FromType->isFunctionType() && !FromType->isArrayType() && 579 Context.getCanonicalType(FromType) != Context.OverloadTy) { 580 SCS.First = ICK_Lvalue_To_Rvalue; 581 582 // If T is a non-class type, the type of the rvalue is the 583 // cv-unqualified version of T. Otherwise, the type of the rvalue 584 // is T (C++ 4.1p1). C++ can't get here with class types; in C, we 585 // just strip the qualifiers because they don't matter. 586 FromType = FromType.getUnqualifiedType(); 587 } else if (FromType->isArrayType()) { 588 // Array-to-pointer conversion (C++ 4.2) 589 SCS.First = ICK_Array_To_Pointer; 590 591 // An lvalue or rvalue of type "array of N T" or "array of unknown 592 // bound of T" can be converted to an rvalue of type "pointer to 593 // T" (C++ 4.2p1). 594 FromType = Context.getArrayDecayedType(FromType); 595 596 if (IsStringLiteralToNonConstPointerConversion(From, ToType)) { 597 // This conversion is deprecated. (C++ D.4). 598 SCS.Deprecated = true; 599 600 // For the purpose of ranking in overload resolution 601 // (13.3.3.1.1), this conversion is considered an 602 // array-to-pointer conversion followed by a qualification 603 // conversion (4.4). (C++ 4.2p2) 604 SCS.Second = ICK_Identity; 605 SCS.Third = ICK_Qualification; 606 SCS.setAllToTypes(FromType); 607 return true; 608 } 609 } else if (FromType->isFunctionType() && argIsLvalue == Expr::LV_Valid) { 610 // Function-to-pointer conversion (C++ 4.3). 611 SCS.First = ICK_Function_To_Pointer; 612 613 // An lvalue of function type T can be converted to an rvalue of 614 // type "pointer to T." The result is a pointer to the 615 // function. (C++ 4.3p1). 616 FromType = Context.getPointerType(FromType); 617 } else if (FunctionDecl *Fn 618 = ResolveAddressOfOverloadedFunction(From, ToType, false)) { 619 // Address of overloaded function (C++ [over.over]). 620 SCS.First = ICK_Function_To_Pointer; 621 622 // We were able to resolve the address of the overloaded function, 623 // so we can convert to the type of that function. 624 FromType = Fn->getType(); 625 if (ToType->isLValueReferenceType()) 626 FromType = Context.getLValueReferenceType(FromType); 627 else if (ToType->isRValueReferenceType()) 628 FromType = Context.getRValueReferenceType(FromType); 629 else if (ToType->isMemberPointerType()) { 630 // Resolve address only succeeds if both sides are member pointers, 631 // but it doesn't have to be the same class. See DR 247. 632 // Note that this means that the type of &Derived::fn can be 633 // Ret (Base::*)(Args) if the fn overload actually found is from the 634 // base class, even if it was brought into the derived class via a 635 // using declaration. The standard isn't clear on this issue at all. 636 CXXMethodDecl *M = cast<CXXMethodDecl>(Fn); 637 FromType = Context.getMemberPointerType(FromType, 638 Context.getTypeDeclType(M->getParent()).getTypePtr()); 639 } else 640 FromType = Context.getPointerType(FromType); 641 } else { 642 // We don't require any conversions for the first step. 643 SCS.First = ICK_Identity; 644 } 645 SCS.setToType(0, FromType); 646 647 // The second conversion can be an integral promotion, floating 648 // point promotion, integral conversion, floating point conversion, 649 // floating-integral conversion, pointer conversion, 650 // pointer-to-member conversion, or boolean conversion (C++ 4p1). 651 // For overloading in C, this can also be a "compatible-type" 652 // conversion. 653 bool IncompatibleObjC = false; 654 if (Context.hasSameUnqualifiedType(FromType, ToType)) { 655 // The unqualified versions of the types are the same: there's no 656 // conversion to do. 657 SCS.Second = ICK_Identity; 658 } else if (IsIntegralPromotion(From, FromType, ToType)) { 659 // Integral promotion (C++ 4.5). 660 SCS.Second = ICK_Integral_Promotion; 661 FromType = ToType.getUnqualifiedType(); 662 } else if (IsFloatingPointPromotion(FromType, ToType)) { 663 // Floating point promotion (C++ 4.6). 664 SCS.Second = ICK_Floating_Promotion; 665 FromType = ToType.getUnqualifiedType(); 666 } else if (IsComplexPromotion(FromType, ToType)) { 667 // Complex promotion (Clang extension) 668 SCS.Second = ICK_Complex_Promotion; 669 FromType = ToType.getUnqualifiedType(); 670 } else if ((FromType->isIntegralType() || FromType->isEnumeralType()) && 671 (ToType->isIntegralType() && !ToType->isEnumeralType())) { 672 // Integral conversions (C++ 4.7). 673 SCS.Second = ICK_Integral_Conversion; 674 FromType = ToType.getUnqualifiedType(); 675 } else if (FromType->isFloatingType() && ToType->isFloatingType()) { 676 // Floating point conversions (C++ 4.8). 677 SCS.Second = ICK_Floating_Conversion; 678 FromType = ToType.getUnqualifiedType(); 679 } else if (FromType->isComplexType() && ToType->isComplexType()) { 680 // Complex conversions (C99 6.3.1.6) 681 SCS.Second = ICK_Complex_Conversion; 682 FromType = ToType.getUnqualifiedType(); 683 } else if ((FromType->isFloatingType() && 684 ToType->isIntegralType() && (!ToType->isBooleanType() && 685 !ToType->isEnumeralType())) || 686 ((FromType->isIntegralType() || FromType->isEnumeralType()) && 687 ToType->isFloatingType())) { 688 // Floating-integral conversions (C++ 4.9). 689 SCS.Second = ICK_Floating_Integral; 690 FromType = ToType.getUnqualifiedType(); 691 } else if ((FromType->isComplexType() && ToType->isArithmeticType()) || 692 (ToType->isComplexType() && FromType->isArithmeticType())) { 693 // Complex-real conversions (C99 6.3.1.7) 694 SCS.Second = ICK_Complex_Real; 695 FromType = ToType.getUnqualifiedType(); 696 } else if (IsPointerConversion(From, FromType, ToType, InOverloadResolution, 697 FromType, IncompatibleObjC)) { 698 // Pointer conversions (C++ 4.10). 699 SCS.Second = ICK_Pointer_Conversion; 700 SCS.IncompatibleObjC = IncompatibleObjC; 701 } else if (IsMemberPointerConversion(From, FromType, ToType, 702 InOverloadResolution, FromType)) { 703 // Pointer to member conversions (4.11). 704 SCS.Second = ICK_Pointer_Member; 705 } else if (ToType->isBooleanType() && 706 (FromType->isArithmeticType() || 707 FromType->isEnumeralType() || 708 FromType->isAnyPointerType() || 709 FromType->isBlockPointerType() || 710 FromType->isMemberPointerType() || 711 FromType->isNullPtrType())) { 712 // Boolean conversions (C++ 4.12). 713 SCS.Second = ICK_Boolean_Conversion; 714 FromType = Context.BoolTy; 715 } else if (!getLangOptions().CPlusPlus && 716 Context.typesAreCompatible(ToType, FromType)) { 717 // Compatible conversions (Clang extension for C function overloading) 718 SCS.Second = ICK_Compatible_Conversion; 719 } else if (IsNoReturnConversion(Context, FromType, ToType, FromType)) { 720 // Treat a conversion that strips "noreturn" as an identity conversion. 721 SCS.Second = ICK_NoReturn_Adjustment; 722 } else { 723 // No second conversion required. 724 SCS.Second = ICK_Identity; 725 } 726 SCS.setToType(1, FromType); 727 728 QualType CanonFrom; 729 QualType CanonTo; 730 // The third conversion can be a qualification conversion (C++ 4p1). 731 if (IsQualificationConversion(FromType, ToType)) { 732 SCS.Third = ICK_Qualification; 733 FromType = ToType; 734 CanonFrom = Context.getCanonicalType(FromType); 735 CanonTo = Context.getCanonicalType(ToType); 736 } else { 737 // No conversion required 738 SCS.Third = ICK_Identity; 739 740 // C++ [over.best.ics]p6: 741 // [...] Any difference in top-level cv-qualification is 742 // subsumed by the initialization itself and does not constitute 743 // a conversion. [...] 744 CanonFrom = Context.getCanonicalType(FromType); 745 CanonTo = Context.getCanonicalType(ToType); 746 if (CanonFrom.getLocalUnqualifiedType() 747 == CanonTo.getLocalUnqualifiedType() && 748 CanonFrom.getLocalCVRQualifiers() != CanonTo.getLocalCVRQualifiers()) { 749 FromType = ToType; 750 CanonFrom = CanonTo; 751 } 752 } 753 SCS.setToType(2, FromType); 754 755 // If we have not converted the argument type to the parameter type, 756 // this is a bad conversion sequence. 757 if (CanonFrom != CanonTo) 758 return false; 759 760 return true; 761} 762 763/// IsIntegralPromotion - Determines whether the conversion from the 764/// expression From (whose potentially-adjusted type is FromType) to 765/// ToType is an integral promotion (C++ 4.5). If so, returns true and 766/// sets PromotedType to the promoted type. 767bool Sema::IsIntegralPromotion(Expr *From, QualType FromType, QualType ToType) { 768 const BuiltinType *To = ToType->getAs<BuiltinType>(); 769 // All integers are built-in. 770 if (!To) { 771 return false; 772 } 773 774 // An rvalue of type char, signed char, unsigned char, short int, or 775 // unsigned short int can be converted to an rvalue of type int if 776 // int can represent all the values of the source type; otherwise, 777 // the source rvalue can be converted to an rvalue of type unsigned 778 // int (C++ 4.5p1). 779 if (FromType->isPromotableIntegerType() && !FromType->isBooleanType() && 780 !FromType->isEnumeralType()) { 781 if (// We can promote any signed, promotable integer type to an int 782 (FromType->isSignedIntegerType() || 783 // We can promote any unsigned integer type whose size is 784 // less than int to an int. 785 (!FromType->isSignedIntegerType() && 786 Context.getTypeSize(FromType) < Context.getTypeSize(ToType)))) { 787 return To->getKind() == BuiltinType::Int; 788 } 789 790 return To->getKind() == BuiltinType::UInt; 791 } 792 793 // An rvalue of type wchar_t (3.9.1) or an enumeration type (7.2) 794 // can be converted to an rvalue of the first of the following types 795 // that can represent all the values of its underlying type: int, 796 // unsigned int, long, or unsigned long (C++ 4.5p2). 797 798 // We pre-calculate the promotion type for enum types. 799 if (const EnumType *FromEnumType = FromType->getAs<EnumType>()) 800 if (ToType->isIntegerType()) 801 return Context.hasSameUnqualifiedType(ToType, 802 FromEnumType->getDecl()->getPromotionType()); 803 804 if (FromType->isWideCharType() && ToType->isIntegerType()) { 805 // Determine whether the type we're converting from is signed or 806 // unsigned. 807 bool FromIsSigned; 808 uint64_t FromSize = Context.getTypeSize(FromType); 809 810 // FIXME: Is wchar_t signed or unsigned? We assume it's signed for now. 811 FromIsSigned = true; 812 813 // The types we'll try to promote to, in the appropriate 814 // order. Try each of these types. 815 QualType PromoteTypes[6] = { 816 Context.IntTy, Context.UnsignedIntTy, 817 Context.LongTy, Context.UnsignedLongTy , 818 Context.LongLongTy, Context.UnsignedLongLongTy 819 }; 820 for (int Idx = 0; Idx < 6; ++Idx) { 821 uint64_t ToSize = Context.getTypeSize(PromoteTypes[Idx]); 822 if (FromSize < ToSize || 823 (FromSize == ToSize && 824 FromIsSigned == PromoteTypes[Idx]->isSignedIntegerType())) { 825 // We found the type that we can promote to. If this is the 826 // type we wanted, we have a promotion. Otherwise, no 827 // promotion. 828 return Context.hasSameUnqualifiedType(ToType, PromoteTypes[Idx]); 829 } 830 } 831 } 832 833 // An rvalue for an integral bit-field (9.6) can be converted to an 834 // rvalue of type int if int can represent all the values of the 835 // bit-field; otherwise, it can be converted to unsigned int if 836 // unsigned int can represent all the values of the bit-field. If 837 // the bit-field is larger yet, no integral promotion applies to 838 // it. If the bit-field has an enumerated type, it is treated as any 839 // other value of that type for promotion purposes (C++ 4.5p3). 840 // FIXME: We should delay checking of bit-fields until we actually perform the 841 // conversion. 842 using llvm::APSInt; 843 if (From) 844 if (FieldDecl *MemberDecl = From->getBitField()) { 845 APSInt BitWidth; 846 if (FromType->isIntegralType() && !FromType->isEnumeralType() && 847 MemberDecl->getBitWidth()->isIntegerConstantExpr(BitWidth, Context)) { 848 APSInt ToSize(BitWidth.getBitWidth(), BitWidth.isUnsigned()); 849 ToSize = Context.getTypeSize(ToType); 850 851 // Are we promoting to an int from a bitfield that fits in an int? 852 if (BitWidth < ToSize || 853 (FromType->isSignedIntegerType() && BitWidth <= ToSize)) { 854 return To->getKind() == BuiltinType::Int; 855 } 856 857 // Are we promoting to an unsigned int from an unsigned bitfield 858 // that fits into an unsigned int? 859 if (FromType->isUnsignedIntegerType() && BitWidth <= ToSize) { 860 return To->getKind() == BuiltinType::UInt; 861 } 862 863 return false; 864 } 865 } 866 867 // An rvalue of type bool can be converted to an rvalue of type int, 868 // with false becoming zero and true becoming one (C++ 4.5p4). 869 if (FromType->isBooleanType() && To->getKind() == BuiltinType::Int) { 870 return true; 871 } 872 873 return false; 874} 875 876/// IsFloatingPointPromotion - Determines whether the conversion from 877/// FromType to ToType is a floating point promotion (C++ 4.6). If so, 878/// returns true and sets PromotedType to the promoted type. 879bool Sema::IsFloatingPointPromotion(QualType FromType, QualType ToType) { 880 /// An rvalue of type float can be converted to an rvalue of type 881 /// double. (C++ 4.6p1). 882 if (const BuiltinType *FromBuiltin = FromType->getAs<BuiltinType>()) 883 if (const BuiltinType *ToBuiltin = ToType->getAs<BuiltinType>()) { 884 if (FromBuiltin->getKind() == BuiltinType::Float && 885 ToBuiltin->getKind() == BuiltinType::Double) 886 return true; 887 888 // C99 6.3.1.5p1: 889 // When a float is promoted to double or long double, or a 890 // double is promoted to long double [...]. 891 if (!getLangOptions().CPlusPlus && 892 (FromBuiltin->getKind() == BuiltinType::Float || 893 FromBuiltin->getKind() == BuiltinType::Double) && 894 (ToBuiltin->getKind() == BuiltinType::LongDouble)) 895 return true; 896 } 897 898 return false; 899} 900 901/// \brief Determine if a conversion is a complex promotion. 902/// 903/// A complex promotion is defined as a complex -> complex conversion 904/// where the conversion between the underlying real types is a 905/// floating-point or integral promotion. 906bool Sema::IsComplexPromotion(QualType FromType, QualType ToType) { 907 const ComplexType *FromComplex = FromType->getAs<ComplexType>(); 908 if (!FromComplex) 909 return false; 910 911 const ComplexType *ToComplex = ToType->getAs<ComplexType>(); 912 if (!ToComplex) 913 return false; 914 915 return IsFloatingPointPromotion(FromComplex->getElementType(), 916 ToComplex->getElementType()) || 917 IsIntegralPromotion(0, FromComplex->getElementType(), 918 ToComplex->getElementType()); 919} 920 921/// BuildSimilarlyQualifiedPointerType - In a pointer conversion from 922/// the pointer type FromPtr to a pointer to type ToPointee, with the 923/// same type qualifiers as FromPtr has on its pointee type. ToType, 924/// if non-empty, will be a pointer to ToType that may or may not have 925/// the right set of qualifiers on its pointee. 926static QualType 927BuildSimilarlyQualifiedPointerType(const PointerType *FromPtr, 928 QualType ToPointee, QualType ToType, 929 ASTContext &Context) { 930 QualType CanonFromPointee = Context.getCanonicalType(FromPtr->getPointeeType()); 931 QualType CanonToPointee = Context.getCanonicalType(ToPointee); 932 Qualifiers Quals = CanonFromPointee.getQualifiers(); 933 934 // Exact qualifier match -> return the pointer type we're converting to. 935 if (CanonToPointee.getLocalQualifiers() == Quals) { 936 // ToType is exactly what we need. Return it. 937 if (!ToType.isNull()) 938 return ToType; 939 940 // Build a pointer to ToPointee. It has the right qualifiers 941 // already. 942 return Context.getPointerType(ToPointee); 943 } 944 945 // Just build a canonical type that has the right qualifiers. 946 return Context.getPointerType( 947 Context.getQualifiedType(CanonToPointee.getLocalUnqualifiedType(), 948 Quals)); 949} 950 951/// BuildSimilarlyQualifiedObjCObjectPointerType - In a pointer conversion from 952/// the FromType, which is an objective-c pointer, to ToType, which may or may 953/// not have the right set of qualifiers. 954static QualType 955BuildSimilarlyQualifiedObjCObjectPointerType(QualType FromType, 956 QualType ToType, 957 ASTContext &Context) { 958 QualType CanonFromType = Context.getCanonicalType(FromType); 959 QualType CanonToType = Context.getCanonicalType(ToType); 960 Qualifiers Quals = CanonFromType.getQualifiers(); 961 962 // Exact qualifier match -> return the pointer type we're converting to. 963 if (CanonToType.getLocalQualifiers() == Quals) 964 return ToType; 965 966 // Just build a canonical type that has the right qualifiers. 967 return Context.getQualifiedType(CanonToType.getLocalUnqualifiedType(), Quals); 968} 969 970static bool isNullPointerConstantForConversion(Expr *Expr, 971 bool InOverloadResolution, 972 ASTContext &Context) { 973 // Handle value-dependent integral null pointer constants correctly. 974 // http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#903 975 if (Expr->isValueDependent() && !Expr->isTypeDependent() && 976 Expr->getType()->isIntegralType()) 977 return !InOverloadResolution; 978 979 return Expr->isNullPointerConstant(Context, 980 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull 981 : Expr::NPC_ValueDependentIsNull); 982} 983 984/// IsPointerConversion - Determines whether the conversion of the 985/// expression From, which has the (possibly adjusted) type FromType, 986/// can be converted to the type ToType via a pointer conversion (C++ 987/// 4.10). If so, returns true and places the converted type (that 988/// might differ from ToType in its cv-qualifiers at some level) into 989/// ConvertedType. 990/// 991/// This routine also supports conversions to and from block pointers 992/// and conversions with Objective-C's 'id', 'id<protocols...>', and 993/// pointers to interfaces. FIXME: Once we've determined the 994/// appropriate overloading rules for Objective-C, we may want to 995/// split the Objective-C checks into a different routine; however, 996/// GCC seems to consider all of these conversions to be pointer 997/// conversions, so for now they live here. IncompatibleObjC will be 998/// set if the conversion is an allowed Objective-C conversion that 999/// should result in a warning. 1000bool Sema::IsPointerConversion(Expr *From, QualType FromType, QualType ToType, 1001 bool InOverloadResolution, 1002 QualType& ConvertedType, 1003 bool &IncompatibleObjC) { 1004 IncompatibleObjC = false; 1005 if (isObjCPointerConversion(FromType, ToType, ConvertedType, IncompatibleObjC)) 1006 return true; 1007 1008 // Conversion from a null pointer constant to any Objective-C pointer type. 1009 if (ToType->isObjCObjectPointerType() && 1010 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1011 ConvertedType = ToType; 1012 return true; 1013 } 1014 1015 // Blocks: Block pointers can be converted to void*. 1016 if (FromType->isBlockPointerType() && ToType->isPointerType() && 1017 ToType->getAs<PointerType>()->getPointeeType()->isVoidType()) { 1018 ConvertedType = ToType; 1019 return true; 1020 } 1021 // Blocks: A null pointer constant can be converted to a block 1022 // pointer type. 1023 if (ToType->isBlockPointerType() && 1024 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1025 ConvertedType = ToType; 1026 return true; 1027 } 1028 1029 // If the left-hand-side is nullptr_t, the right side can be a null 1030 // pointer constant. 1031 if (ToType->isNullPtrType() && 1032 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1033 ConvertedType = ToType; 1034 return true; 1035 } 1036 1037 const PointerType* ToTypePtr = ToType->getAs<PointerType>(); 1038 if (!ToTypePtr) 1039 return false; 1040 1041 // A null pointer constant can be converted to a pointer type (C++ 4.10p1). 1042 if (isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1043 ConvertedType = ToType; 1044 return true; 1045 } 1046 1047 // Beyond this point, both types need to be pointers 1048 // , including objective-c pointers. 1049 QualType ToPointeeType = ToTypePtr->getPointeeType(); 1050 if (FromType->isObjCObjectPointerType() && ToPointeeType->isVoidType()) { 1051 ConvertedType = BuildSimilarlyQualifiedObjCObjectPointerType(FromType, 1052 ToType, Context); 1053 return true; 1054 1055 } 1056 const PointerType *FromTypePtr = FromType->getAs<PointerType>(); 1057 if (!FromTypePtr) 1058 return false; 1059 1060 QualType FromPointeeType = FromTypePtr->getPointeeType(); 1061 1062 // An rvalue of type "pointer to cv T," where T is an object type, 1063 // can be converted to an rvalue of type "pointer to cv void" (C++ 1064 // 4.10p2). 1065 if (FromPointeeType->isObjectType() && ToPointeeType->isVoidType()) { 1066 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1067 ToPointeeType, 1068 ToType, Context); 1069 return true; 1070 } 1071 1072 // When we're overloading in C, we allow a special kind of pointer 1073 // conversion for compatible-but-not-identical pointee types. 1074 if (!getLangOptions().CPlusPlus && 1075 Context.typesAreCompatible(FromPointeeType, ToPointeeType)) { 1076 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1077 ToPointeeType, 1078 ToType, Context); 1079 return true; 1080 } 1081 1082 // C++ [conv.ptr]p3: 1083 // 1084 // An rvalue of type "pointer to cv D," where D is a class type, 1085 // can be converted to an rvalue of type "pointer to cv B," where 1086 // B is a base class (clause 10) of D. If B is an inaccessible 1087 // (clause 11) or ambiguous (10.2) base class of D, a program that 1088 // necessitates this conversion is ill-formed. The result of the 1089 // conversion is a pointer to the base class sub-object of the 1090 // derived class object. The null pointer value is converted to 1091 // the null pointer value of the destination type. 1092 // 1093 // Note that we do not check for ambiguity or inaccessibility 1094 // here. That is handled by CheckPointerConversion. 1095 if (getLangOptions().CPlusPlus && 1096 FromPointeeType->isRecordType() && ToPointeeType->isRecordType() && 1097 !RequireCompleteType(From->getLocStart(), FromPointeeType, PDiag()) && 1098 IsDerivedFrom(FromPointeeType, ToPointeeType)) { 1099 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1100 ToPointeeType, 1101 ToType, Context); 1102 return true; 1103 } 1104 1105 return false; 1106} 1107 1108/// isObjCPointerConversion - Determines whether this is an 1109/// Objective-C pointer conversion. Subroutine of IsPointerConversion, 1110/// with the same arguments and return values. 1111bool Sema::isObjCPointerConversion(QualType FromType, QualType ToType, 1112 QualType& ConvertedType, 1113 bool &IncompatibleObjC) { 1114 if (!getLangOptions().ObjC1) 1115 return false; 1116 1117 // First, we handle all conversions on ObjC object pointer types. 1118 const ObjCObjectPointerType* ToObjCPtr = ToType->getAs<ObjCObjectPointerType>(); 1119 const ObjCObjectPointerType *FromObjCPtr = 1120 FromType->getAs<ObjCObjectPointerType>(); 1121 1122 if (ToObjCPtr && FromObjCPtr) { 1123 // Objective C++: We're able to convert between "id" or "Class" and a 1124 // pointer to any interface (in both directions). 1125 if (ToObjCPtr->isObjCBuiltinType() && FromObjCPtr->isObjCBuiltinType()) { 1126 ConvertedType = ToType; 1127 return true; 1128 } 1129 // Conversions with Objective-C's id<...>. 1130 if ((FromObjCPtr->isObjCQualifiedIdType() || 1131 ToObjCPtr->isObjCQualifiedIdType()) && 1132 Context.ObjCQualifiedIdTypesAreCompatible(ToType, FromType, 1133 /*compare=*/false)) { 1134 ConvertedType = ToType; 1135 return true; 1136 } 1137 // Objective C++: We're able to convert from a pointer to an 1138 // interface to a pointer to a different interface. 1139 if (Context.canAssignObjCInterfaces(ToObjCPtr, FromObjCPtr)) { 1140 ConvertedType = ToType; 1141 return true; 1142 } 1143 1144 if (Context.canAssignObjCInterfaces(FromObjCPtr, ToObjCPtr)) { 1145 // Okay: this is some kind of implicit downcast of Objective-C 1146 // interfaces, which is permitted. However, we're going to 1147 // complain about it. 1148 IncompatibleObjC = true; 1149 ConvertedType = FromType; 1150 return true; 1151 } 1152 } 1153 // Beyond this point, both types need to be C pointers or block pointers. 1154 QualType ToPointeeType; 1155 if (const PointerType *ToCPtr = ToType->getAs<PointerType>()) 1156 ToPointeeType = ToCPtr->getPointeeType(); 1157 else if (const BlockPointerType *ToBlockPtr = 1158 ToType->getAs<BlockPointerType>()) { 1159 // Objective C++: We're able to convert from a pointer to any object 1160 // to a block pointer type. 1161 if (FromObjCPtr && FromObjCPtr->isObjCBuiltinType()) { 1162 ConvertedType = ToType; 1163 return true; 1164 } 1165 ToPointeeType = ToBlockPtr->getPointeeType(); 1166 } 1167 else if (FromType->getAs<BlockPointerType>() && 1168 ToObjCPtr && ToObjCPtr->isObjCBuiltinType()) { 1169 // Objective C++: We're able to convert from a block pointer type to a 1170 // pointer to any object. 1171 ConvertedType = ToType; 1172 return true; 1173 } 1174 else 1175 return false; 1176 1177 QualType FromPointeeType; 1178 if (const PointerType *FromCPtr = FromType->getAs<PointerType>()) 1179 FromPointeeType = FromCPtr->getPointeeType(); 1180 else if (const BlockPointerType *FromBlockPtr = FromType->getAs<BlockPointerType>()) 1181 FromPointeeType = FromBlockPtr->getPointeeType(); 1182 else 1183 return false; 1184 1185 // If we have pointers to pointers, recursively check whether this 1186 // is an Objective-C conversion. 1187 if (FromPointeeType->isPointerType() && ToPointeeType->isPointerType() && 1188 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, 1189 IncompatibleObjC)) { 1190 // We always complain about this conversion. 1191 IncompatibleObjC = true; 1192 ConvertedType = ToType; 1193 return true; 1194 } 1195 // Allow conversion of pointee being objective-c pointer to another one; 1196 // as in I* to id. 1197 if (FromPointeeType->getAs<ObjCObjectPointerType>() && 1198 ToPointeeType->getAs<ObjCObjectPointerType>() && 1199 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, 1200 IncompatibleObjC)) { 1201 ConvertedType = ToType; 1202 return true; 1203 } 1204 1205 // If we have pointers to functions or blocks, check whether the only 1206 // differences in the argument and result types are in Objective-C 1207 // pointer conversions. If so, we permit the conversion (but 1208 // complain about it). 1209 const FunctionProtoType *FromFunctionType 1210 = FromPointeeType->getAs<FunctionProtoType>(); 1211 const FunctionProtoType *ToFunctionType 1212 = ToPointeeType->getAs<FunctionProtoType>(); 1213 if (FromFunctionType && ToFunctionType) { 1214 // If the function types are exactly the same, this isn't an 1215 // Objective-C pointer conversion. 1216 if (Context.getCanonicalType(FromPointeeType) 1217 == Context.getCanonicalType(ToPointeeType)) 1218 return false; 1219 1220 // Perform the quick checks that will tell us whether these 1221 // function types are obviously different. 1222 if (FromFunctionType->getNumArgs() != ToFunctionType->getNumArgs() || 1223 FromFunctionType->isVariadic() != ToFunctionType->isVariadic() || 1224 FromFunctionType->getTypeQuals() != ToFunctionType->getTypeQuals()) 1225 return false; 1226 1227 bool HasObjCConversion = false; 1228 if (Context.getCanonicalType(FromFunctionType->getResultType()) 1229 == Context.getCanonicalType(ToFunctionType->getResultType())) { 1230 // Okay, the types match exactly. Nothing to do. 1231 } else if (isObjCPointerConversion(FromFunctionType->getResultType(), 1232 ToFunctionType->getResultType(), 1233 ConvertedType, IncompatibleObjC)) { 1234 // Okay, we have an Objective-C pointer conversion. 1235 HasObjCConversion = true; 1236 } else { 1237 // Function types are too different. Abort. 1238 return false; 1239 } 1240 1241 // Check argument types. 1242 for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumArgs(); 1243 ArgIdx != NumArgs; ++ArgIdx) { 1244 QualType FromArgType = FromFunctionType->getArgType(ArgIdx); 1245 QualType ToArgType = ToFunctionType->getArgType(ArgIdx); 1246 if (Context.getCanonicalType(FromArgType) 1247 == Context.getCanonicalType(ToArgType)) { 1248 // Okay, the types match exactly. Nothing to do. 1249 } else if (isObjCPointerConversion(FromArgType, ToArgType, 1250 ConvertedType, IncompatibleObjC)) { 1251 // Okay, we have an Objective-C pointer conversion. 1252 HasObjCConversion = true; 1253 } else { 1254 // Argument types are too different. Abort. 1255 return false; 1256 } 1257 } 1258 1259 if (HasObjCConversion) { 1260 // We had an Objective-C conversion. Allow this pointer 1261 // conversion, but complain about it. 1262 ConvertedType = ToType; 1263 IncompatibleObjC = true; 1264 return true; 1265 } 1266 } 1267 1268 return false; 1269} 1270 1271/// CheckPointerConversion - Check the pointer conversion from the 1272/// expression From to the type ToType. This routine checks for 1273/// ambiguous or inaccessible derived-to-base pointer 1274/// conversions for which IsPointerConversion has already returned 1275/// true. It returns true and produces a diagnostic if there was an 1276/// error, or returns false otherwise. 1277bool Sema::CheckPointerConversion(Expr *From, QualType ToType, 1278 CastExpr::CastKind &Kind, 1279 bool IgnoreBaseAccess) { 1280 QualType FromType = From->getType(); 1281 1282 if (const PointerType *FromPtrType = FromType->getAs<PointerType>()) 1283 if (const PointerType *ToPtrType = ToType->getAs<PointerType>()) { 1284 QualType FromPointeeType = FromPtrType->getPointeeType(), 1285 ToPointeeType = ToPtrType->getPointeeType(); 1286 1287 if (FromPointeeType->isRecordType() && 1288 ToPointeeType->isRecordType()) { 1289 // We must have a derived-to-base conversion. Check an 1290 // ambiguous or inaccessible conversion. 1291 if (CheckDerivedToBaseConversion(FromPointeeType, ToPointeeType, 1292 From->getExprLoc(), 1293 From->getSourceRange(), 1294 IgnoreBaseAccess)) 1295 return true; 1296 1297 // The conversion was successful. 1298 Kind = CastExpr::CK_DerivedToBase; 1299 } 1300 } 1301 if (const ObjCObjectPointerType *FromPtrType = 1302 FromType->getAs<ObjCObjectPointerType>()) 1303 if (const ObjCObjectPointerType *ToPtrType = 1304 ToType->getAs<ObjCObjectPointerType>()) { 1305 // Objective-C++ conversions are always okay. 1306 // FIXME: We should have a different class of conversions for the 1307 // Objective-C++ implicit conversions. 1308 if (FromPtrType->isObjCBuiltinType() || ToPtrType->isObjCBuiltinType()) 1309 return false; 1310 1311 } 1312 return false; 1313} 1314 1315/// IsMemberPointerConversion - Determines whether the conversion of the 1316/// expression From, which has the (possibly adjusted) type FromType, can be 1317/// converted to the type ToType via a member pointer conversion (C++ 4.11). 1318/// If so, returns true and places the converted type (that might differ from 1319/// ToType in its cv-qualifiers at some level) into ConvertedType. 1320bool Sema::IsMemberPointerConversion(Expr *From, QualType FromType, 1321 QualType ToType, 1322 bool InOverloadResolution, 1323 QualType &ConvertedType) { 1324 const MemberPointerType *ToTypePtr = ToType->getAs<MemberPointerType>(); 1325 if (!ToTypePtr) 1326 return false; 1327 1328 // A null pointer constant can be converted to a member pointer (C++ 4.11p1) 1329 if (From->isNullPointerConstant(Context, 1330 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull 1331 : Expr::NPC_ValueDependentIsNull)) { 1332 ConvertedType = ToType; 1333 return true; 1334 } 1335 1336 // Otherwise, both types have to be member pointers. 1337 const MemberPointerType *FromTypePtr = FromType->getAs<MemberPointerType>(); 1338 if (!FromTypePtr) 1339 return false; 1340 1341 // A pointer to member of B can be converted to a pointer to member of D, 1342 // where D is derived from B (C++ 4.11p2). 1343 QualType FromClass(FromTypePtr->getClass(), 0); 1344 QualType ToClass(ToTypePtr->getClass(), 0); 1345 // FIXME: What happens when these are dependent? Is this function even called? 1346 1347 if (IsDerivedFrom(ToClass, FromClass)) { 1348 ConvertedType = Context.getMemberPointerType(FromTypePtr->getPointeeType(), 1349 ToClass.getTypePtr()); 1350 return true; 1351 } 1352 1353 return false; 1354} 1355 1356/// CheckMemberPointerConversion - Check the member pointer conversion from the 1357/// expression From to the type ToType. This routine checks for ambiguous or 1358/// virtual or inaccessible base-to-derived member pointer conversions 1359/// for which IsMemberPointerConversion has already returned true. It returns 1360/// true and produces a diagnostic if there was an error, or returns false 1361/// otherwise. 1362bool Sema::CheckMemberPointerConversion(Expr *From, QualType ToType, 1363 CastExpr::CastKind &Kind, 1364 bool IgnoreBaseAccess) { 1365 QualType FromType = From->getType(); 1366 const MemberPointerType *FromPtrType = FromType->getAs<MemberPointerType>(); 1367 if (!FromPtrType) { 1368 // This must be a null pointer to member pointer conversion 1369 assert(From->isNullPointerConstant(Context, 1370 Expr::NPC_ValueDependentIsNull) && 1371 "Expr must be null pointer constant!"); 1372 Kind = CastExpr::CK_NullToMemberPointer; 1373 return false; 1374 } 1375 1376 const MemberPointerType *ToPtrType = ToType->getAs<MemberPointerType>(); 1377 assert(ToPtrType && "No member pointer cast has a target type " 1378 "that is not a member pointer."); 1379 1380 QualType FromClass = QualType(FromPtrType->getClass(), 0); 1381 QualType ToClass = QualType(ToPtrType->getClass(), 0); 1382 1383 // FIXME: What about dependent types? 1384 assert(FromClass->isRecordType() && "Pointer into non-class."); 1385 assert(ToClass->isRecordType() && "Pointer into non-class."); 1386 1387 CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/ true, 1388 /*DetectVirtual=*/true); 1389 bool DerivationOkay = IsDerivedFrom(ToClass, FromClass, Paths); 1390 assert(DerivationOkay && 1391 "Should not have been called if derivation isn't OK."); 1392 (void)DerivationOkay; 1393 1394 if (Paths.isAmbiguous(Context.getCanonicalType(FromClass). 1395 getUnqualifiedType())) { 1396 std::string PathDisplayStr = getAmbiguousPathsDisplayString(Paths); 1397 Diag(From->getExprLoc(), diag::err_ambiguous_memptr_conv) 1398 << 0 << FromClass << ToClass << PathDisplayStr << From->getSourceRange(); 1399 return true; 1400 } 1401 1402 if (const RecordType *VBase = Paths.getDetectedVirtual()) { 1403 Diag(From->getExprLoc(), diag::err_memptr_conv_via_virtual) 1404 << FromClass << ToClass << QualType(VBase, 0) 1405 << From->getSourceRange(); 1406 return true; 1407 } 1408 1409 if (!IgnoreBaseAccess) 1410 CheckBaseClassAccess(From->getExprLoc(), /*BaseToDerived*/ true, 1411 FromClass, ToClass, Paths.front()); 1412 1413 // Must be a base to derived member conversion. 1414 Kind = CastExpr::CK_BaseToDerivedMemberPointer; 1415 return false; 1416} 1417 1418/// IsQualificationConversion - Determines whether the conversion from 1419/// an rvalue of type FromType to ToType is a qualification conversion 1420/// (C++ 4.4). 1421bool 1422Sema::IsQualificationConversion(QualType FromType, QualType ToType) { 1423 FromType = Context.getCanonicalType(FromType); 1424 ToType = Context.getCanonicalType(ToType); 1425 1426 // If FromType and ToType are the same type, this is not a 1427 // qualification conversion. 1428 if (FromType.getUnqualifiedType() == ToType.getUnqualifiedType()) 1429 return false; 1430 1431 // (C++ 4.4p4): 1432 // A conversion can add cv-qualifiers at levels other than the first 1433 // in multi-level pointers, subject to the following rules: [...] 1434 bool PreviousToQualsIncludeConst = true; 1435 bool UnwrappedAnyPointer = false; 1436 while (UnwrapSimilarPointerTypes(FromType, ToType)) { 1437 // Within each iteration of the loop, we check the qualifiers to 1438 // determine if this still looks like a qualification 1439 // conversion. Then, if all is well, we unwrap one more level of 1440 // pointers or pointers-to-members and do it all again 1441 // until there are no more pointers or pointers-to-members left to 1442 // unwrap. 1443 UnwrappedAnyPointer = true; 1444 1445 // -- for every j > 0, if const is in cv 1,j then const is in cv 1446 // 2,j, and similarly for volatile. 1447 if (!ToType.isAtLeastAsQualifiedAs(FromType)) 1448 return false; 1449 1450 // -- if the cv 1,j and cv 2,j are different, then const is in 1451 // every cv for 0 < k < j. 1452 if (FromType.getCVRQualifiers() != ToType.getCVRQualifiers() 1453 && !PreviousToQualsIncludeConst) 1454 return false; 1455 1456 // Keep track of whether all prior cv-qualifiers in the "to" type 1457 // include const. 1458 PreviousToQualsIncludeConst 1459 = PreviousToQualsIncludeConst && ToType.isConstQualified(); 1460 } 1461 1462 // We are left with FromType and ToType being the pointee types 1463 // after unwrapping the original FromType and ToType the same number 1464 // of types. If we unwrapped any pointers, and if FromType and 1465 // ToType have the same unqualified type (since we checked 1466 // qualifiers above), then this is a qualification conversion. 1467 return UnwrappedAnyPointer && Context.hasSameUnqualifiedType(FromType,ToType); 1468} 1469 1470/// Determines whether there is a user-defined conversion sequence 1471/// (C++ [over.ics.user]) that converts expression From to the type 1472/// ToType. If such a conversion exists, User will contain the 1473/// user-defined conversion sequence that performs such a conversion 1474/// and this routine will return true. Otherwise, this routine returns 1475/// false and User is unspecified. 1476/// 1477/// \param AllowConversionFunctions true if the conversion should 1478/// consider conversion functions at all. If false, only constructors 1479/// will be considered. 1480/// 1481/// \param AllowExplicit true if the conversion should consider C++0x 1482/// "explicit" conversion functions as well as non-explicit conversion 1483/// functions (C++0x [class.conv.fct]p2). 1484/// 1485/// \param ForceRValue true if the expression should be treated as an rvalue 1486/// for overload resolution. 1487/// \param UserCast true if looking for user defined conversion for a static 1488/// cast. 1489OverloadingResult Sema::IsUserDefinedConversion(Expr *From, QualType ToType, 1490 UserDefinedConversionSequence& User, 1491 OverloadCandidateSet& CandidateSet, 1492 bool AllowConversionFunctions, 1493 bool AllowExplicit, 1494 bool ForceRValue, 1495 bool UserCast) { 1496 if (const RecordType *ToRecordType = ToType->getAs<RecordType>()) { 1497 if (RequireCompleteType(From->getLocStart(), ToType, PDiag())) { 1498 // We're not going to find any constructors. 1499 } else if (CXXRecordDecl *ToRecordDecl 1500 = dyn_cast<CXXRecordDecl>(ToRecordType->getDecl())) { 1501 // C++ [over.match.ctor]p1: 1502 // When objects of class type are direct-initialized (8.5), or 1503 // copy-initialized from an expression of the same or a 1504 // derived class type (8.5), overload resolution selects the 1505 // constructor. [...] For copy-initialization, the candidate 1506 // functions are all the converting constructors (12.3.1) of 1507 // that class. The argument list is the expression-list within 1508 // the parentheses of the initializer. 1509 bool SuppressUserConversions = !UserCast; 1510 if (Context.hasSameUnqualifiedType(ToType, From->getType()) || 1511 IsDerivedFrom(From->getType(), ToType)) { 1512 SuppressUserConversions = false; 1513 AllowConversionFunctions = false; 1514 } 1515 1516 DeclarationName ConstructorName 1517 = Context.DeclarationNames.getCXXConstructorName( 1518 Context.getCanonicalType(ToType).getUnqualifiedType()); 1519 DeclContext::lookup_iterator Con, ConEnd; 1520 for (llvm::tie(Con, ConEnd) 1521 = ToRecordDecl->lookup(ConstructorName); 1522 Con != ConEnd; ++Con) { 1523 // Find the constructor (which may be a template). 1524 CXXConstructorDecl *Constructor = 0; 1525 FunctionTemplateDecl *ConstructorTmpl 1526 = dyn_cast<FunctionTemplateDecl>(*Con); 1527 if (ConstructorTmpl) 1528 Constructor 1529 = cast<CXXConstructorDecl>(ConstructorTmpl->getTemplatedDecl()); 1530 else 1531 Constructor = cast<CXXConstructorDecl>(*Con); 1532 1533 if (!Constructor->isInvalidDecl() && 1534 Constructor->isConvertingConstructor(AllowExplicit)) { 1535 if (ConstructorTmpl) 1536 AddTemplateOverloadCandidate(ConstructorTmpl, 1537 ConstructorTmpl->getAccess(), 1538 /*ExplicitArgs*/ 0, 1539 &From, 1, CandidateSet, 1540 SuppressUserConversions, ForceRValue); 1541 else 1542 // Allow one user-defined conversion when user specifies a 1543 // From->ToType conversion via an static cast (c-style, etc). 1544 AddOverloadCandidate(Constructor, Constructor->getAccess(), 1545 &From, 1, CandidateSet, 1546 SuppressUserConversions, ForceRValue); 1547 } 1548 } 1549 } 1550 } 1551 1552 if (!AllowConversionFunctions) { 1553 // Don't allow any conversion functions to enter the overload set. 1554 } else if (RequireCompleteType(From->getLocStart(), From->getType(), 1555 PDiag(0) 1556 << From->getSourceRange())) { 1557 // No conversion functions from incomplete types. 1558 } else if (const RecordType *FromRecordType 1559 = From->getType()->getAs<RecordType>()) { 1560 if (CXXRecordDecl *FromRecordDecl 1561 = dyn_cast<CXXRecordDecl>(FromRecordType->getDecl())) { 1562 // Add all of the conversion functions as candidates. 1563 const UnresolvedSetImpl *Conversions 1564 = FromRecordDecl->getVisibleConversionFunctions(); 1565 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 1566 E = Conversions->end(); I != E; ++I) { 1567 NamedDecl *D = *I; 1568 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext()); 1569 if (isa<UsingShadowDecl>(D)) 1570 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 1571 1572 CXXConversionDecl *Conv; 1573 FunctionTemplateDecl *ConvTemplate; 1574 if ((ConvTemplate = dyn_cast<FunctionTemplateDecl>(*I))) 1575 Conv = dyn_cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 1576 else 1577 Conv = dyn_cast<CXXConversionDecl>(*I); 1578 1579 if (AllowExplicit || !Conv->isExplicit()) { 1580 if (ConvTemplate) 1581 AddTemplateConversionCandidate(ConvTemplate, I.getAccess(), 1582 ActingContext, From, ToType, 1583 CandidateSet); 1584 else 1585 AddConversionCandidate(Conv, I.getAccess(), ActingContext, 1586 From, ToType, CandidateSet); 1587 } 1588 } 1589 } 1590 } 1591 1592 OverloadCandidateSet::iterator Best; 1593 switch (BestViableFunction(CandidateSet, From->getLocStart(), Best)) { 1594 case OR_Success: 1595 // Record the standard conversion we used and the conversion function. 1596 if (CXXConstructorDecl *Constructor 1597 = dyn_cast<CXXConstructorDecl>(Best->Function)) { 1598 // C++ [over.ics.user]p1: 1599 // If the user-defined conversion is specified by a 1600 // constructor (12.3.1), the initial standard conversion 1601 // sequence converts the source type to the type required by 1602 // the argument of the constructor. 1603 // 1604 QualType ThisType = Constructor->getThisType(Context); 1605 if (Best->Conversions[0].isEllipsis()) 1606 User.EllipsisConversion = true; 1607 else { 1608 User.Before = Best->Conversions[0].Standard; 1609 User.EllipsisConversion = false; 1610 } 1611 User.ConversionFunction = Constructor; 1612 User.After.setAsIdentityConversion(); 1613 User.After.setFromType( 1614 ThisType->getAs<PointerType>()->getPointeeType()); 1615 User.After.setAllToTypes(ToType); 1616 return OR_Success; 1617 } else if (CXXConversionDecl *Conversion 1618 = dyn_cast<CXXConversionDecl>(Best->Function)) { 1619 // C++ [over.ics.user]p1: 1620 // 1621 // [...] If the user-defined conversion is specified by a 1622 // conversion function (12.3.2), the initial standard 1623 // conversion sequence converts the source type to the 1624 // implicit object parameter of the conversion function. 1625 User.Before = Best->Conversions[0].Standard; 1626 User.ConversionFunction = Conversion; 1627 User.EllipsisConversion = false; 1628 1629 // C++ [over.ics.user]p2: 1630 // The second standard conversion sequence converts the 1631 // result of the user-defined conversion to the target type 1632 // for the sequence. Since an implicit conversion sequence 1633 // is an initialization, the special rules for 1634 // initialization by user-defined conversion apply when 1635 // selecting the best user-defined conversion for a 1636 // user-defined conversion sequence (see 13.3.3 and 1637 // 13.3.3.1). 1638 User.After = Best->FinalConversion; 1639 return OR_Success; 1640 } else { 1641 assert(false && "Not a constructor or conversion function?"); 1642 return OR_No_Viable_Function; 1643 } 1644 1645 case OR_No_Viable_Function: 1646 return OR_No_Viable_Function; 1647 case OR_Deleted: 1648 // No conversion here! We're done. 1649 return OR_Deleted; 1650 1651 case OR_Ambiguous: 1652 return OR_Ambiguous; 1653 } 1654 1655 return OR_No_Viable_Function; 1656} 1657 1658bool 1659Sema::DiagnoseMultipleUserDefinedConversion(Expr *From, QualType ToType) { 1660 ImplicitConversionSequence ICS; 1661 OverloadCandidateSet CandidateSet(From->getExprLoc()); 1662 OverloadingResult OvResult = 1663 IsUserDefinedConversion(From, ToType, ICS.UserDefined, 1664 CandidateSet, true, false, false); 1665 if (OvResult == OR_Ambiguous) 1666 Diag(From->getSourceRange().getBegin(), 1667 diag::err_typecheck_ambiguous_condition) 1668 << From->getType() << ToType << From->getSourceRange(); 1669 else if (OvResult == OR_No_Viable_Function && !CandidateSet.empty()) 1670 Diag(From->getSourceRange().getBegin(), 1671 diag::err_typecheck_nonviable_condition) 1672 << From->getType() << ToType << From->getSourceRange(); 1673 else 1674 return false; 1675 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, &From, 1); 1676 return true; 1677} 1678 1679/// CompareImplicitConversionSequences - Compare two implicit 1680/// conversion sequences to determine whether one is better than the 1681/// other or if they are indistinguishable (C++ 13.3.3.2). 1682ImplicitConversionSequence::CompareKind 1683Sema::CompareImplicitConversionSequences(const ImplicitConversionSequence& ICS1, 1684 const ImplicitConversionSequence& ICS2) 1685{ 1686 // (C++ 13.3.3.2p2): When comparing the basic forms of implicit 1687 // conversion sequences (as defined in 13.3.3.1) 1688 // -- a standard conversion sequence (13.3.3.1.1) is a better 1689 // conversion sequence than a user-defined conversion sequence or 1690 // an ellipsis conversion sequence, and 1691 // -- a user-defined conversion sequence (13.3.3.1.2) is a better 1692 // conversion sequence than an ellipsis conversion sequence 1693 // (13.3.3.1.3). 1694 // 1695 // C++0x [over.best.ics]p10: 1696 // For the purpose of ranking implicit conversion sequences as 1697 // described in 13.3.3.2, the ambiguous conversion sequence is 1698 // treated as a user-defined sequence that is indistinguishable 1699 // from any other user-defined conversion sequence. 1700 if (ICS1.getKind() < ICS2.getKind()) { 1701 if (!(ICS1.isUserDefined() && ICS2.isAmbiguous())) 1702 return ImplicitConversionSequence::Better; 1703 } else if (ICS2.getKind() < ICS1.getKind()) { 1704 if (!(ICS2.isUserDefined() && ICS1.isAmbiguous())) 1705 return ImplicitConversionSequence::Worse; 1706 } 1707 1708 if (ICS1.isAmbiguous() || ICS2.isAmbiguous()) 1709 return ImplicitConversionSequence::Indistinguishable; 1710 1711 // Two implicit conversion sequences of the same form are 1712 // indistinguishable conversion sequences unless one of the 1713 // following rules apply: (C++ 13.3.3.2p3): 1714 if (ICS1.isStandard()) 1715 return CompareStandardConversionSequences(ICS1.Standard, ICS2.Standard); 1716 else if (ICS1.isUserDefined()) { 1717 // User-defined conversion sequence U1 is a better conversion 1718 // sequence than another user-defined conversion sequence U2 if 1719 // they contain the same user-defined conversion function or 1720 // constructor and if the second standard conversion sequence of 1721 // U1 is better than the second standard conversion sequence of 1722 // U2 (C++ 13.3.3.2p3). 1723 if (ICS1.UserDefined.ConversionFunction == 1724 ICS2.UserDefined.ConversionFunction) 1725 return CompareStandardConversionSequences(ICS1.UserDefined.After, 1726 ICS2.UserDefined.After); 1727 } 1728 1729 return ImplicitConversionSequence::Indistinguishable; 1730} 1731 1732// Per 13.3.3.2p3, compare the given standard conversion sequences to 1733// determine if one is a proper subset of the other. 1734static ImplicitConversionSequence::CompareKind 1735compareStandardConversionSubsets(ASTContext &Context, 1736 const StandardConversionSequence& SCS1, 1737 const StandardConversionSequence& SCS2) { 1738 ImplicitConversionSequence::CompareKind Result 1739 = ImplicitConversionSequence::Indistinguishable; 1740 1741 if (SCS1.Second != SCS2.Second) { 1742 if (SCS1.Second == ICK_Identity) 1743 Result = ImplicitConversionSequence::Better; 1744 else if (SCS2.Second == ICK_Identity) 1745 Result = ImplicitConversionSequence::Worse; 1746 else 1747 return ImplicitConversionSequence::Indistinguishable; 1748 } else if (!Context.hasSameType(SCS1.getToType(1), SCS2.getToType(1))) 1749 return ImplicitConversionSequence::Indistinguishable; 1750 1751 if (SCS1.Third == SCS2.Third) { 1752 return Context.hasSameType(SCS1.getToType(2), SCS2.getToType(2))? Result 1753 : ImplicitConversionSequence::Indistinguishable; 1754 } 1755 1756 if (SCS1.Third == ICK_Identity) 1757 return Result == ImplicitConversionSequence::Worse 1758 ? ImplicitConversionSequence::Indistinguishable 1759 : ImplicitConversionSequence::Better; 1760 1761 if (SCS2.Third == ICK_Identity) 1762 return Result == ImplicitConversionSequence::Better 1763 ? ImplicitConversionSequence::Indistinguishable 1764 : ImplicitConversionSequence::Worse; 1765 1766 return ImplicitConversionSequence::Indistinguishable; 1767} 1768 1769/// CompareStandardConversionSequences - Compare two standard 1770/// conversion sequences to determine whether one is better than the 1771/// other or if they are indistinguishable (C++ 13.3.3.2p3). 1772ImplicitConversionSequence::CompareKind 1773Sema::CompareStandardConversionSequences(const StandardConversionSequence& SCS1, 1774 const StandardConversionSequence& SCS2) 1775{ 1776 // Standard conversion sequence S1 is a better conversion sequence 1777 // than standard conversion sequence S2 if (C++ 13.3.3.2p3): 1778 1779 // -- S1 is a proper subsequence of S2 (comparing the conversion 1780 // sequences in the canonical form defined by 13.3.3.1.1, 1781 // excluding any Lvalue Transformation; the identity conversion 1782 // sequence is considered to be a subsequence of any 1783 // non-identity conversion sequence) or, if not that, 1784 if (ImplicitConversionSequence::CompareKind CK 1785 = compareStandardConversionSubsets(Context, SCS1, SCS2)) 1786 return CK; 1787 1788 // -- the rank of S1 is better than the rank of S2 (by the rules 1789 // defined below), or, if not that, 1790 ImplicitConversionRank Rank1 = SCS1.getRank(); 1791 ImplicitConversionRank Rank2 = SCS2.getRank(); 1792 if (Rank1 < Rank2) 1793 return ImplicitConversionSequence::Better; 1794 else if (Rank2 < Rank1) 1795 return ImplicitConversionSequence::Worse; 1796 1797 // (C++ 13.3.3.2p4): Two conversion sequences with the same rank 1798 // are indistinguishable unless one of the following rules 1799 // applies: 1800 1801 // A conversion that is not a conversion of a pointer, or 1802 // pointer to member, to bool is better than another conversion 1803 // that is such a conversion. 1804 if (SCS1.isPointerConversionToBool() != SCS2.isPointerConversionToBool()) 1805 return SCS2.isPointerConversionToBool() 1806 ? ImplicitConversionSequence::Better 1807 : ImplicitConversionSequence::Worse; 1808 1809 // C++ [over.ics.rank]p4b2: 1810 // 1811 // If class B is derived directly or indirectly from class A, 1812 // conversion of B* to A* is better than conversion of B* to 1813 // void*, and conversion of A* to void* is better than conversion 1814 // of B* to void*. 1815 bool SCS1ConvertsToVoid 1816 = SCS1.isPointerConversionToVoidPointer(Context); 1817 bool SCS2ConvertsToVoid 1818 = SCS2.isPointerConversionToVoidPointer(Context); 1819 if (SCS1ConvertsToVoid != SCS2ConvertsToVoid) { 1820 // Exactly one of the conversion sequences is a conversion to 1821 // a void pointer; it's the worse conversion. 1822 return SCS2ConvertsToVoid ? ImplicitConversionSequence::Better 1823 : ImplicitConversionSequence::Worse; 1824 } else if (!SCS1ConvertsToVoid && !SCS2ConvertsToVoid) { 1825 // Neither conversion sequence converts to a void pointer; compare 1826 // their derived-to-base conversions. 1827 if (ImplicitConversionSequence::CompareKind DerivedCK 1828 = CompareDerivedToBaseConversions(SCS1, SCS2)) 1829 return DerivedCK; 1830 } else if (SCS1ConvertsToVoid && SCS2ConvertsToVoid) { 1831 // Both conversion sequences are conversions to void 1832 // pointers. Compare the source types to determine if there's an 1833 // inheritance relationship in their sources. 1834 QualType FromType1 = SCS1.getFromType(); 1835 QualType FromType2 = SCS2.getFromType(); 1836 1837 // Adjust the types we're converting from via the array-to-pointer 1838 // conversion, if we need to. 1839 if (SCS1.First == ICK_Array_To_Pointer) 1840 FromType1 = Context.getArrayDecayedType(FromType1); 1841 if (SCS2.First == ICK_Array_To_Pointer) 1842 FromType2 = Context.getArrayDecayedType(FromType2); 1843 1844 QualType FromPointee1 1845 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1846 QualType FromPointee2 1847 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1848 1849 if (IsDerivedFrom(FromPointee2, FromPointee1)) 1850 return ImplicitConversionSequence::Better; 1851 else if (IsDerivedFrom(FromPointee1, FromPointee2)) 1852 return ImplicitConversionSequence::Worse; 1853 1854 // Objective-C++: If one interface is more specific than the 1855 // other, it is the better one. 1856 const ObjCInterfaceType* FromIface1 = FromPointee1->getAs<ObjCInterfaceType>(); 1857 const ObjCInterfaceType* FromIface2 = FromPointee2->getAs<ObjCInterfaceType>(); 1858 if (FromIface1 && FromIface1) { 1859 if (Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 1860 return ImplicitConversionSequence::Better; 1861 else if (Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 1862 return ImplicitConversionSequence::Worse; 1863 } 1864 } 1865 1866 // Compare based on qualification conversions (C++ 13.3.3.2p3, 1867 // bullet 3). 1868 if (ImplicitConversionSequence::CompareKind QualCK 1869 = CompareQualificationConversions(SCS1, SCS2)) 1870 return QualCK; 1871 1872 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding) { 1873 // C++0x [over.ics.rank]p3b4: 1874 // -- S1 and S2 are reference bindings (8.5.3) and neither refers to an 1875 // implicit object parameter of a non-static member function declared 1876 // without a ref-qualifier, and S1 binds an rvalue reference to an 1877 // rvalue and S2 binds an lvalue reference. 1878 // FIXME: We don't know if we're dealing with the implicit object parameter, 1879 // or if the member function in this case has a ref qualifier. 1880 // (Of course, we don't have ref qualifiers yet.) 1881 if (SCS1.RRefBinding != SCS2.RRefBinding) 1882 return SCS1.RRefBinding ? ImplicitConversionSequence::Better 1883 : ImplicitConversionSequence::Worse; 1884 1885 // C++ [over.ics.rank]p3b4: 1886 // -- S1 and S2 are reference bindings (8.5.3), and the types to 1887 // which the references refer are the same type except for 1888 // top-level cv-qualifiers, and the type to which the reference 1889 // initialized by S2 refers is more cv-qualified than the type 1890 // to which the reference initialized by S1 refers. 1891 QualType T1 = SCS1.getToType(2); 1892 QualType T2 = SCS2.getToType(2); 1893 T1 = Context.getCanonicalType(T1); 1894 T2 = Context.getCanonicalType(T2); 1895 Qualifiers T1Quals, T2Quals; 1896 QualType UnqualT1 = Context.getUnqualifiedArrayType(T1, T1Quals); 1897 QualType UnqualT2 = Context.getUnqualifiedArrayType(T2, T2Quals); 1898 if (UnqualT1 == UnqualT2) { 1899 // If the type is an array type, promote the element qualifiers to the type 1900 // for comparison. 1901 if (isa<ArrayType>(T1) && T1Quals) 1902 T1 = Context.getQualifiedType(UnqualT1, T1Quals); 1903 if (isa<ArrayType>(T2) && T2Quals) 1904 T2 = Context.getQualifiedType(UnqualT2, T2Quals); 1905 if (T2.isMoreQualifiedThan(T1)) 1906 return ImplicitConversionSequence::Better; 1907 else if (T1.isMoreQualifiedThan(T2)) 1908 return ImplicitConversionSequence::Worse; 1909 } 1910 } 1911 1912 return ImplicitConversionSequence::Indistinguishable; 1913} 1914 1915/// CompareQualificationConversions - Compares two standard conversion 1916/// sequences to determine whether they can be ranked based on their 1917/// qualification conversions (C++ 13.3.3.2p3 bullet 3). 1918ImplicitConversionSequence::CompareKind 1919Sema::CompareQualificationConversions(const StandardConversionSequence& SCS1, 1920 const StandardConversionSequence& SCS2) { 1921 // C++ 13.3.3.2p3: 1922 // -- S1 and S2 differ only in their qualification conversion and 1923 // yield similar types T1 and T2 (C++ 4.4), respectively, and the 1924 // cv-qualification signature of type T1 is a proper subset of 1925 // the cv-qualification signature of type T2, and S1 is not the 1926 // deprecated string literal array-to-pointer conversion (4.2). 1927 if (SCS1.First != SCS2.First || SCS1.Second != SCS2.Second || 1928 SCS1.Third != SCS2.Third || SCS1.Third != ICK_Qualification) 1929 return ImplicitConversionSequence::Indistinguishable; 1930 1931 // FIXME: the example in the standard doesn't use a qualification 1932 // conversion (!) 1933 QualType T1 = SCS1.getToType(2); 1934 QualType T2 = SCS2.getToType(2); 1935 T1 = Context.getCanonicalType(T1); 1936 T2 = Context.getCanonicalType(T2); 1937 Qualifiers T1Quals, T2Quals; 1938 QualType UnqualT1 = Context.getUnqualifiedArrayType(T1, T1Quals); 1939 QualType UnqualT2 = Context.getUnqualifiedArrayType(T2, T2Quals); 1940 1941 // If the types are the same, we won't learn anything by unwrapped 1942 // them. 1943 if (UnqualT1 == UnqualT2) 1944 return ImplicitConversionSequence::Indistinguishable; 1945 1946 // If the type is an array type, promote the element qualifiers to the type 1947 // for comparison. 1948 if (isa<ArrayType>(T1) && T1Quals) 1949 T1 = Context.getQualifiedType(UnqualT1, T1Quals); 1950 if (isa<ArrayType>(T2) && T2Quals) 1951 T2 = Context.getQualifiedType(UnqualT2, T2Quals); 1952 1953 ImplicitConversionSequence::CompareKind Result 1954 = ImplicitConversionSequence::Indistinguishable; 1955 while (UnwrapSimilarPointerTypes(T1, T2)) { 1956 // Within each iteration of the loop, we check the qualifiers to 1957 // determine if this still looks like a qualification 1958 // conversion. Then, if all is well, we unwrap one more level of 1959 // pointers or pointers-to-members and do it all again 1960 // until there are no more pointers or pointers-to-members left 1961 // to unwrap. This essentially mimics what 1962 // IsQualificationConversion does, but here we're checking for a 1963 // strict subset of qualifiers. 1964 if (T1.getCVRQualifiers() == T2.getCVRQualifiers()) 1965 // The qualifiers are the same, so this doesn't tell us anything 1966 // about how the sequences rank. 1967 ; 1968 else if (T2.isMoreQualifiedThan(T1)) { 1969 // T1 has fewer qualifiers, so it could be the better sequence. 1970 if (Result == ImplicitConversionSequence::Worse) 1971 // Neither has qualifiers that are a subset of the other's 1972 // qualifiers. 1973 return ImplicitConversionSequence::Indistinguishable; 1974 1975 Result = ImplicitConversionSequence::Better; 1976 } else if (T1.isMoreQualifiedThan(T2)) { 1977 // T2 has fewer qualifiers, so it could be the better sequence. 1978 if (Result == ImplicitConversionSequence::Better) 1979 // Neither has qualifiers that are a subset of the other's 1980 // qualifiers. 1981 return ImplicitConversionSequence::Indistinguishable; 1982 1983 Result = ImplicitConversionSequence::Worse; 1984 } else { 1985 // Qualifiers are disjoint. 1986 return ImplicitConversionSequence::Indistinguishable; 1987 } 1988 1989 // If the types after this point are equivalent, we're done. 1990 if (Context.hasSameUnqualifiedType(T1, T2)) 1991 break; 1992 } 1993 1994 // Check that the winning standard conversion sequence isn't using 1995 // the deprecated string literal array to pointer conversion. 1996 switch (Result) { 1997 case ImplicitConversionSequence::Better: 1998 if (SCS1.Deprecated) 1999 Result = ImplicitConversionSequence::Indistinguishable; 2000 break; 2001 2002 case ImplicitConversionSequence::Indistinguishable: 2003 break; 2004 2005 case ImplicitConversionSequence::Worse: 2006 if (SCS2.Deprecated) 2007 Result = ImplicitConversionSequence::Indistinguishable; 2008 break; 2009 } 2010 2011 return Result; 2012} 2013 2014/// CompareDerivedToBaseConversions - Compares two standard conversion 2015/// sequences to determine whether they can be ranked based on their 2016/// various kinds of derived-to-base conversions (C++ 2017/// [over.ics.rank]p4b3). As part of these checks, we also look at 2018/// conversions between Objective-C interface types. 2019ImplicitConversionSequence::CompareKind 2020Sema::CompareDerivedToBaseConversions(const StandardConversionSequence& SCS1, 2021 const StandardConversionSequence& SCS2) { 2022 QualType FromType1 = SCS1.getFromType(); 2023 QualType ToType1 = SCS1.getToType(1); 2024 QualType FromType2 = SCS2.getFromType(); 2025 QualType ToType2 = SCS2.getToType(1); 2026 2027 // Adjust the types we're converting from via the array-to-pointer 2028 // conversion, if we need to. 2029 if (SCS1.First == ICK_Array_To_Pointer) 2030 FromType1 = Context.getArrayDecayedType(FromType1); 2031 if (SCS2.First == ICK_Array_To_Pointer) 2032 FromType2 = Context.getArrayDecayedType(FromType2); 2033 2034 // Canonicalize all of the types. 2035 FromType1 = Context.getCanonicalType(FromType1); 2036 ToType1 = Context.getCanonicalType(ToType1); 2037 FromType2 = Context.getCanonicalType(FromType2); 2038 ToType2 = Context.getCanonicalType(ToType2); 2039 2040 // C++ [over.ics.rank]p4b3: 2041 // 2042 // If class B is derived directly or indirectly from class A and 2043 // class C is derived directly or indirectly from B, 2044 // 2045 // For Objective-C, we let A, B, and C also be Objective-C 2046 // interfaces. 2047 2048 // Compare based on pointer conversions. 2049 if (SCS1.Second == ICK_Pointer_Conversion && 2050 SCS2.Second == ICK_Pointer_Conversion && 2051 /*FIXME: Remove if Objective-C id conversions get their own rank*/ 2052 FromType1->isPointerType() && FromType2->isPointerType() && 2053 ToType1->isPointerType() && ToType2->isPointerType()) { 2054 QualType FromPointee1 2055 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2056 QualType ToPointee1 2057 = ToType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2058 QualType FromPointee2 2059 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2060 QualType ToPointee2 2061 = ToType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2062 2063 const ObjCInterfaceType* FromIface1 = FromPointee1->getAs<ObjCInterfaceType>(); 2064 const ObjCInterfaceType* FromIface2 = FromPointee2->getAs<ObjCInterfaceType>(); 2065 const ObjCInterfaceType* ToIface1 = ToPointee1->getAs<ObjCInterfaceType>(); 2066 const ObjCInterfaceType* ToIface2 = ToPointee2->getAs<ObjCInterfaceType>(); 2067 2068 // -- conversion of C* to B* is better than conversion of C* to A*, 2069 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 2070 if (IsDerivedFrom(ToPointee1, ToPointee2)) 2071 return ImplicitConversionSequence::Better; 2072 else if (IsDerivedFrom(ToPointee2, ToPointee1)) 2073 return ImplicitConversionSequence::Worse; 2074 2075 if (ToIface1 && ToIface2) { 2076 if (Context.canAssignObjCInterfaces(ToIface2, ToIface1)) 2077 return ImplicitConversionSequence::Better; 2078 else if (Context.canAssignObjCInterfaces(ToIface1, ToIface2)) 2079 return ImplicitConversionSequence::Worse; 2080 } 2081 } 2082 2083 // -- conversion of B* to A* is better than conversion of C* to A*, 2084 if (FromPointee1 != FromPointee2 && ToPointee1 == ToPointee2) { 2085 if (IsDerivedFrom(FromPointee2, FromPointee1)) 2086 return ImplicitConversionSequence::Better; 2087 else if (IsDerivedFrom(FromPointee1, FromPointee2)) 2088 return ImplicitConversionSequence::Worse; 2089 2090 if (FromIface1 && FromIface2) { 2091 if (Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 2092 return ImplicitConversionSequence::Better; 2093 else if (Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 2094 return ImplicitConversionSequence::Worse; 2095 } 2096 } 2097 } 2098 2099 // Compare based on reference bindings. 2100 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding && 2101 SCS1.Second == ICK_Derived_To_Base) { 2102 // -- binding of an expression of type C to a reference of type 2103 // B& is better than binding an expression of type C to a 2104 // reference of type A&, 2105 if (Context.hasSameUnqualifiedType(FromType1, FromType2) && 2106 !Context.hasSameUnqualifiedType(ToType1, ToType2)) { 2107 if (IsDerivedFrom(ToType1, ToType2)) 2108 return ImplicitConversionSequence::Better; 2109 else if (IsDerivedFrom(ToType2, ToType1)) 2110 return ImplicitConversionSequence::Worse; 2111 } 2112 2113 // -- binding of an expression of type B to a reference of type 2114 // A& is better than binding an expression of type C to a 2115 // reference of type A&, 2116 if (!Context.hasSameUnqualifiedType(FromType1, FromType2) && 2117 Context.hasSameUnqualifiedType(ToType1, ToType2)) { 2118 if (IsDerivedFrom(FromType2, FromType1)) 2119 return ImplicitConversionSequence::Better; 2120 else if (IsDerivedFrom(FromType1, FromType2)) 2121 return ImplicitConversionSequence::Worse; 2122 } 2123 } 2124 2125 // Ranking of member-pointer types. 2126 if (SCS1.Second == ICK_Pointer_Member && SCS2.Second == ICK_Pointer_Member && 2127 FromType1->isMemberPointerType() && FromType2->isMemberPointerType() && 2128 ToType1->isMemberPointerType() && ToType2->isMemberPointerType()) { 2129 const MemberPointerType * FromMemPointer1 = 2130 FromType1->getAs<MemberPointerType>(); 2131 const MemberPointerType * ToMemPointer1 = 2132 ToType1->getAs<MemberPointerType>(); 2133 const MemberPointerType * FromMemPointer2 = 2134 FromType2->getAs<MemberPointerType>(); 2135 const MemberPointerType * ToMemPointer2 = 2136 ToType2->getAs<MemberPointerType>(); 2137 const Type *FromPointeeType1 = FromMemPointer1->getClass(); 2138 const Type *ToPointeeType1 = ToMemPointer1->getClass(); 2139 const Type *FromPointeeType2 = FromMemPointer2->getClass(); 2140 const Type *ToPointeeType2 = ToMemPointer2->getClass(); 2141 QualType FromPointee1 = QualType(FromPointeeType1, 0).getUnqualifiedType(); 2142 QualType ToPointee1 = QualType(ToPointeeType1, 0).getUnqualifiedType(); 2143 QualType FromPointee2 = QualType(FromPointeeType2, 0).getUnqualifiedType(); 2144 QualType ToPointee2 = QualType(ToPointeeType2, 0).getUnqualifiedType(); 2145 // conversion of A::* to B::* is better than conversion of A::* to C::*, 2146 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 2147 if (IsDerivedFrom(ToPointee1, ToPointee2)) 2148 return ImplicitConversionSequence::Worse; 2149 else if (IsDerivedFrom(ToPointee2, ToPointee1)) 2150 return ImplicitConversionSequence::Better; 2151 } 2152 // conversion of B::* to C::* is better than conversion of A::* to C::* 2153 if (ToPointee1 == ToPointee2 && FromPointee1 != FromPointee2) { 2154 if (IsDerivedFrom(FromPointee1, FromPointee2)) 2155 return ImplicitConversionSequence::Better; 2156 else if (IsDerivedFrom(FromPointee2, FromPointee1)) 2157 return ImplicitConversionSequence::Worse; 2158 } 2159 } 2160 2161 if (SCS1.CopyConstructor && SCS2.CopyConstructor && 2162 SCS1.Second == ICK_Derived_To_Base) { 2163 // -- conversion of C to B is better than conversion of C to A, 2164 if (Context.hasSameUnqualifiedType(FromType1, FromType2) && 2165 !Context.hasSameUnqualifiedType(ToType1, ToType2)) { 2166 if (IsDerivedFrom(ToType1, ToType2)) 2167 return ImplicitConversionSequence::Better; 2168 else if (IsDerivedFrom(ToType2, ToType1)) 2169 return ImplicitConversionSequence::Worse; 2170 } 2171 2172 // -- conversion of B to A is better than conversion of C to A. 2173 if (!Context.hasSameUnqualifiedType(FromType1, FromType2) && 2174 Context.hasSameUnqualifiedType(ToType1, ToType2)) { 2175 if (IsDerivedFrom(FromType2, FromType1)) 2176 return ImplicitConversionSequence::Better; 2177 else if (IsDerivedFrom(FromType1, FromType2)) 2178 return ImplicitConversionSequence::Worse; 2179 } 2180 } 2181 2182 return ImplicitConversionSequence::Indistinguishable; 2183} 2184 2185/// TryCopyInitialization - Try to copy-initialize a value of type 2186/// ToType from the expression From. Return the implicit conversion 2187/// sequence required to pass this argument, which may be a bad 2188/// conversion sequence (meaning that the argument cannot be passed to 2189/// a parameter of this type). If @p SuppressUserConversions, then we 2190/// do not permit any user-defined conversion sequences. If @p ForceRValue, 2191/// then we treat @p From as an rvalue, even if it is an lvalue. 2192ImplicitConversionSequence 2193Sema::TryCopyInitialization(Expr *From, QualType ToType, 2194 bool SuppressUserConversions, bool ForceRValue, 2195 bool InOverloadResolution) { 2196 if (ToType->isReferenceType()) { 2197 ImplicitConversionSequence ICS; 2198 ICS.Bad.init(BadConversionSequence::no_conversion, From, ToType); 2199 CheckReferenceInit(From, ToType, 2200 /*FIXME:*/From->getLocStart(), 2201 SuppressUserConversions, 2202 /*AllowExplicit=*/false, 2203 ForceRValue, 2204 &ICS); 2205 return ICS; 2206 } else { 2207 return TryImplicitConversion(From, ToType, 2208 SuppressUserConversions, 2209 /*AllowExplicit=*/false, 2210 ForceRValue, 2211 InOverloadResolution); 2212 } 2213} 2214 2215/// PerformCopyInitialization - Copy-initialize an object of type @p ToType with 2216/// the expression @p From. Returns true (and emits a diagnostic) if there was 2217/// an error, returns false if the initialization succeeded. Elidable should 2218/// be true when the copy may be elided (C++ 12.8p15). Overload resolution works 2219/// differently in C++0x for this case. 2220bool Sema::PerformCopyInitialization(Expr *&From, QualType ToType, 2221 AssignmentAction Action, bool Elidable) { 2222 if (!getLangOptions().CPlusPlus) { 2223 // In C, argument passing is the same as performing an assignment. 2224 QualType FromType = From->getType(); 2225 2226 AssignConvertType ConvTy = 2227 CheckSingleAssignmentConstraints(ToType, From); 2228 if (ConvTy != Compatible && 2229 CheckTransparentUnionArgumentConstraints(ToType, From) == Compatible) 2230 ConvTy = Compatible; 2231 2232 return DiagnoseAssignmentResult(ConvTy, From->getLocStart(), ToType, 2233 FromType, From, Action); 2234 } 2235 2236 if (ToType->isReferenceType()) 2237 return CheckReferenceInit(From, ToType, 2238 /*FIXME:*/From->getLocStart(), 2239 /*SuppressUserConversions=*/false, 2240 /*AllowExplicit=*/false, 2241 /*ForceRValue=*/false); 2242 2243 if (!PerformImplicitConversion(From, ToType, Action, 2244 /*AllowExplicit=*/false, Elidable)) 2245 return false; 2246 if (!DiagnoseMultipleUserDefinedConversion(From, ToType)) 2247 return Diag(From->getSourceRange().getBegin(), 2248 diag::err_typecheck_convert_incompatible) 2249 << ToType << From->getType() << Action << From->getSourceRange(); 2250 return true; 2251} 2252 2253/// TryObjectArgumentInitialization - Try to initialize the object 2254/// parameter of the given member function (@c Method) from the 2255/// expression @p From. 2256ImplicitConversionSequence 2257Sema::TryObjectArgumentInitialization(QualType OrigFromType, 2258 CXXMethodDecl *Method, 2259 CXXRecordDecl *ActingContext) { 2260 QualType ClassType = Context.getTypeDeclType(ActingContext); 2261 // [class.dtor]p2: A destructor can be invoked for a const, volatile or 2262 // const volatile object. 2263 unsigned Quals = isa<CXXDestructorDecl>(Method) ? 2264 Qualifiers::Const | Qualifiers::Volatile : Method->getTypeQualifiers(); 2265 QualType ImplicitParamType = Context.getCVRQualifiedType(ClassType, Quals); 2266 2267 // Set up the conversion sequence as a "bad" conversion, to allow us 2268 // to exit early. 2269 ImplicitConversionSequence ICS; 2270 ICS.Standard.setAsIdentityConversion(); 2271 ICS.setBad(); 2272 2273 // We need to have an object of class type. 2274 QualType FromType = OrigFromType; 2275 if (const PointerType *PT = FromType->getAs<PointerType>()) 2276 FromType = PT->getPointeeType(); 2277 2278 assert(FromType->isRecordType()); 2279 2280 // The implicit object parameter is has the type "reference to cv X", 2281 // where X is the class of which the function is a member 2282 // (C++ [over.match.funcs]p4). However, when finding an implicit 2283 // conversion sequence for the argument, we are not allowed to 2284 // create temporaries or perform user-defined conversions 2285 // (C++ [over.match.funcs]p5). We perform a simplified version of 2286 // reference binding here, that allows class rvalues to bind to 2287 // non-constant references. 2288 2289 // First check the qualifiers. We don't care about lvalue-vs-rvalue 2290 // with the implicit object parameter (C++ [over.match.funcs]p5). 2291 QualType FromTypeCanon = Context.getCanonicalType(FromType); 2292 if (ImplicitParamType.getCVRQualifiers() 2293 != FromTypeCanon.getLocalCVRQualifiers() && 2294 !ImplicitParamType.isAtLeastAsQualifiedAs(FromTypeCanon)) { 2295 ICS.Bad.init(BadConversionSequence::bad_qualifiers, 2296 OrigFromType, ImplicitParamType); 2297 return ICS; 2298 } 2299 2300 // Check that we have either the same type or a derived type. It 2301 // affects the conversion rank. 2302 QualType ClassTypeCanon = Context.getCanonicalType(ClassType); 2303 if (ClassTypeCanon == FromTypeCanon.getLocalUnqualifiedType()) 2304 ICS.Standard.Second = ICK_Identity; 2305 else if (IsDerivedFrom(FromType, ClassType)) 2306 ICS.Standard.Second = ICK_Derived_To_Base; 2307 else { 2308 ICS.Bad.init(BadConversionSequence::unrelated_class, FromType, ImplicitParamType); 2309 return ICS; 2310 } 2311 2312 // Success. Mark this as a reference binding. 2313 ICS.setStandard(); 2314 ICS.Standard.setFromType(FromType); 2315 ICS.Standard.setAllToTypes(ImplicitParamType); 2316 ICS.Standard.ReferenceBinding = true; 2317 ICS.Standard.DirectBinding = true; 2318 ICS.Standard.RRefBinding = false; 2319 return ICS; 2320} 2321 2322/// PerformObjectArgumentInitialization - Perform initialization of 2323/// the implicit object parameter for the given Method with the given 2324/// expression. 2325bool 2326Sema::PerformObjectArgumentInitialization(Expr *&From, CXXMethodDecl *Method) { 2327 QualType FromRecordType, DestType; 2328 QualType ImplicitParamRecordType = 2329 Method->getThisType(Context)->getAs<PointerType>()->getPointeeType(); 2330 2331 if (const PointerType *PT = From->getType()->getAs<PointerType>()) { 2332 FromRecordType = PT->getPointeeType(); 2333 DestType = Method->getThisType(Context); 2334 } else { 2335 FromRecordType = From->getType(); 2336 DestType = ImplicitParamRecordType; 2337 } 2338 2339 // Note that we always use the true parent context when performing 2340 // the actual argument initialization. 2341 ImplicitConversionSequence ICS 2342 = TryObjectArgumentInitialization(From->getType(), Method, 2343 Method->getParent()); 2344 if (ICS.isBad()) 2345 return Diag(From->getSourceRange().getBegin(), 2346 diag::err_implicit_object_parameter_init) 2347 << ImplicitParamRecordType << FromRecordType << From->getSourceRange(); 2348 2349 if (ICS.Standard.Second == ICK_Derived_To_Base && 2350 CheckDerivedToBaseConversion(FromRecordType, 2351 ImplicitParamRecordType, 2352 From->getSourceRange().getBegin(), 2353 From->getSourceRange())) 2354 return true; 2355 2356 ImpCastExprToType(From, DestType, CastExpr::CK_DerivedToBase, 2357 /*isLvalue=*/true); 2358 return false; 2359} 2360 2361/// TryContextuallyConvertToBool - Attempt to contextually convert the 2362/// expression From to bool (C++0x [conv]p3). 2363ImplicitConversionSequence Sema::TryContextuallyConvertToBool(Expr *From) { 2364 return TryImplicitConversion(From, Context.BoolTy, 2365 // FIXME: Are these flags correct? 2366 /*SuppressUserConversions=*/false, 2367 /*AllowExplicit=*/true, 2368 /*ForceRValue=*/false, 2369 /*InOverloadResolution=*/false); 2370} 2371 2372/// PerformContextuallyConvertToBool - Perform a contextual conversion 2373/// of the expression From to bool (C++0x [conv]p3). 2374bool Sema::PerformContextuallyConvertToBool(Expr *&From) { 2375 ImplicitConversionSequence ICS = TryContextuallyConvertToBool(From); 2376 if (!ICS.isBad()) 2377 return PerformImplicitConversion(From, Context.BoolTy, ICS, AA_Converting); 2378 2379 if (!DiagnoseMultipleUserDefinedConversion(From, Context.BoolTy)) 2380 return Diag(From->getSourceRange().getBegin(), 2381 diag::err_typecheck_bool_condition) 2382 << From->getType() << From->getSourceRange(); 2383 return true; 2384} 2385 2386/// AddOverloadCandidate - Adds the given function to the set of 2387/// candidate functions, using the given function call arguments. If 2388/// @p SuppressUserConversions, then don't allow user-defined 2389/// conversions via constructors or conversion operators. 2390/// If @p ForceRValue, treat all arguments as rvalues. This is a slightly 2391/// hacky way to implement the overloading rules for elidable copy 2392/// initialization in C++0x (C++0x 12.8p15). 2393/// 2394/// \para PartialOverloading true if we are performing "partial" overloading 2395/// based on an incomplete set of function arguments. This feature is used by 2396/// code completion. 2397void 2398Sema::AddOverloadCandidate(FunctionDecl *Function, 2399 AccessSpecifier Access, 2400 Expr **Args, unsigned NumArgs, 2401 OverloadCandidateSet& CandidateSet, 2402 bool SuppressUserConversions, 2403 bool ForceRValue, 2404 bool PartialOverloading) { 2405 const FunctionProtoType* Proto 2406 = dyn_cast<FunctionProtoType>(Function->getType()->getAs<FunctionType>()); 2407 assert(Proto && "Functions without a prototype cannot be overloaded"); 2408 assert(!Function->getDescribedFunctionTemplate() && 2409 "Use AddTemplateOverloadCandidate for function templates"); 2410 2411 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Function)) { 2412 if (!isa<CXXConstructorDecl>(Method)) { 2413 // If we get here, it's because we're calling a member function 2414 // that is named without a member access expression (e.g., 2415 // "this->f") that was either written explicitly or created 2416 // implicitly. This can happen with a qualified call to a member 2417 // function, e.g., X::f(). We use an empty type for the implied 2418 // object argument (C++ [over.call.func]p3), and the acting context 2419 // is irrelevant. 2420 AddMethodCandidate(Method, Access, Method->getParent(), 2421 QualType(), Args, NumArgs, CandidateSet, 2422 SuppressUserConversions, ForceRValue); 2423 return; 2424 } 2425 // We treat a constructor like a non-member function, since its object 2426 // argument doesn't participate in overload resolution. 2427 } 2428 2429 if (!CandidateSet.isNewCandidate(Function)) 2430 return; 2431 2432 // Overload resolution is always an unevaluated context. 2433 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 2434 2435 if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(Function)){ 2436 // C++ [class.copy]p3: 2437 // A member function template is never instantiated to perform the copy 2438 // of a class object to an object of its class type. 2439 QualType ClassType = Context.getTypeDeclType(Constructor->getParent()); 2440 if (NumArgs == 1 && 2441 Constructor->isCopyConstructorLikeSpecialization() && 2442 Context.hasSameUnqualifiedType(ClassType, Args[0]->getType())) 2443 return; 2444 } 2445 2446 // Add this candidate 2447 CandidateSet.push_back(OverloadCandidate()); 2448 OverloadCandidate& Candidate = CandidateSet.back(); 2449 Candidate.Function = Function; 2450 Candidate.Access = Access; 2451 Candidate.Viable = true; 2452 Candidate.IsSurrogate = false; 2453 Candidate.IgnoreObjectArgument = false; 2454 2455 unsigned NumArgsInProto = Proto->getNumArgs(); 2456 2457 // (C++ 13.3.2p2): A candidate function having fewer than m 2458 // parameters is viable only if it has an ellipsis in its parameter 2459 // list (8.3.5). 2460 if ((NumArgs + (PartialOverloading && NumArgs)) > NumArgsInProto && 2461 !Proto->isVariadic()) { 2462 Candidate.Viable = false; 2463 Candidate.FailureKind = ovl_fail_too_many_arguments; 2464 return; 2465 } 2466 2467 // (C++ 13.3.2p2): A candidate function having more than m parameters 2468 // is viable only if the (m+1)st parameter has a default argument 2469 // (8.3.6). For the purposes of overload resolution, the 2470 // parameter list is truncated on the right, so that there are 2471 // exactly m parameters. 2472 unsigned MinRequiredArgs = Function->getMinRequiredArguments(); 2473 if (NumArgs < MinRequiredArgs && !PartialOverloading) { 2474 // Not enough arguments. 2475 Candidate.Viable = false; 2476 Candidate.FailureKind = ovl_fail_too_few_arguments; 2477 return; 2478 } 2479 2480 // Determine the implicit conversion sequences for each of the 2481 // arguments. 2482 Candidate.Conversions.resize(NumArgs); 2483 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2484 if (ArgIdx < NumArgsInProto) { 2485 // (C++ 13.3.2p3): for F to be a viable function, there shall 2486 // exist for each argument an implicit conversion sequence 2487 // (13.3.3.1) that converts that argument to the corresponding 2488 // parameter of F. 2489 QualType ParamType = Proto->getArgType(ArgIdx); 2490 Candidate.Conversions[ArgIdx] 2491 = TryCopyInitialization(Args[ArgIdx], ParamType, 2492 SuppressUserConversions, ForceRValue, 2493 /*InOverloadResolution=*/true); 2494 if (Candidate.Conversions[ArgIdx].isBad()) { 2495 Candidate.Viable = false; 2496 Candidate.FailureKind = ovl_fail_bad_conversion; 2497 break; 2498 } 2499 } else { 2500 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2501 // argument for which there is no corresponding parameter is 2502 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2503 Candidate.Conversions[ArgIdx].setEllipsis(); 2504 } 2505 } 2506} 2507 2508/// \brief Add all of the function declarations in the given function set to 2509/// the overload canddiate set. 2510void Sema::AddFunctionCandidates(const UnresolvedSetImpl &Fns, 2511 Expr **Args, unsigned NumArgs, 2512 OverloadCandidateSet& CandidateSet, 2513 bool SuppressUserConversions) { 2514 for (UnresolvedSetIterator F = Fns.begin(), E = Fns.end(); F != E; ++F) { 2515 // FIXME: using declarations 2516 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*F)) { 2517 if (isa<CXXMethodDecl>(FD) && !cast<CXXMethodDecl>(FD)->isStatic()) 2518 AddMethodCandidate(cast<CXXMethodDecl>(FD), F.getAccess(), 2519 cast<CXXMethodDecl>(FD)->getParent(), 2520 Args[0]->getType(), Args + 1, NumArgs - 1, 2521 CandidateSet, SuppressUserConversions); 2522 else 2523 AddOverloadCandidate(FD, AS_none, Args, NumArgs, CandidateSet, 2524 SuppressUserConversions); 2525 } else { 2526 FunctionTemplateDecl *FunTmpl = cast<FunctionTemplateDecl>(*F); 2527 if (isa<CXXMethodDecl>(FunTmpl->getTemplatedDecl()) && 2528 !cast<CXXMethodDecl>(FunTmpl->getTemplatedDecl())->isStatic()) 2529 AddMethodTemplateCandidate(FunTmpl, F.getAccess(), 2530 cast<CXXRecordDecl>(FunTmpl->getDeclContext()), 2531 /*FIXME: explicit args */ 0, 2532 Args[0]->getType(), Args + 1, NumArgs - 1, 2533 CandidateSet, 2534 SuppressUserConversions); 2535 else 2536 AddTemplateOverloadCandidate(FunTmpl, AS_none, 2537 /*FIXME: explicit args */ 0, 2538 Args, NumArgs, CandidateSet, 2539 SuppressUserConversions); 2540 } 2541 } 2542} 2543 2544/// AddMethodCandidate - Adds a named decl (which is some kind of 2545/// method) as a method candidate to the given overload set. 2546void Sema::AddMethodCandidate(NamedDecl *Decl, 2547 AccessSpecifier Access, 2548 QualType ObjectType, 2549 Expr **Args, unsigned NumArgs, 2550 OverloadCandidateSet& CandidateSet, 2551 bool SuppressUserConversions, bool ForceRValue) { 2552 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(Decl->getDeclContext()); 2553 2554 if (isa<UsingShadowDecl>(Decl)) 2555 Decl = cast<UsingShadowDecl>(Decl)->getTargetDecl(); 2556 2557 if (FunctionTemplateDecl *TD = dyn_cast<FunctionTemplateDecl>(Decl)) { 2558 assert(isa<CXXMethodDecl>(TD->getTemplatedDecl()) && 2559 "Expected a member function template"); 2560 AddMethodTemplateCandidate(TD, Access, ActingContext, /*ExplicitArgs*/ 0, 2561 ObjectType, Args, NumArgs, 2562 CandidateSet, 2563 SuppressUserConversions, 2564 ForceRValue); 2565 } else { 2566 AddMethodCandidate(cast<CXXMethodDecl>(Decl), Access, ActingContext, 2567 ObjectType, Args, NumArgs, 2568 CandidateSet, SuppressUserConversions, ForceRValue); 2569 } 2570} 2571 2572/// AddMethodCandidate - Adds the given C++ member function to the set 2573/// of candidate functions, using the given function call arguments 2574/// and the object argument (@c Object). For example, in a call 2575/// @c o.f(a1,a2), @c Object will contain @c o and @c Args will contain 2576/// both @c a1 and @c a2. If @p SuppressUserConversions, then don't 2577/// allow user-defined conversions via constructors or conversion 2578/// operators. If @p ForceRValue, treat all arguments as rvalues. This is 2579/// a slightly hacky way to implement the overloading rules for elidable copy 2580/// initialization in C++0x (C++0x 12.8p15). 2581void 2582Sema::AddMethodCandidate(CXXMethodDecl *Method, AccessSpecifier Access, 2583 CXXRecordDecl *ActingContext, QualType ObjectType, 2584 Expr **Args, unsigned NumArgs, 2585 OverloadCandidateSet& CandidateSet, 2586 bool SuppressUserConversions, bool ForceRValue) { 2587 const FunctionProtoType* Proto 2588 = dyn_cast<FunctionProtoType>(Method->getType()->getAs<FunctionType>()); 2589 assert(Proto && "Methods without a prototype cannot be overloaded"); 2590 assert(!isa<CXXConstructorDecl>(Method) && 2591 "Use AddOverloadCandidate for constructors"); 2592 2593 if (!CandidateSet.isNewCandidate(Method)) 2594 return; 2595 2596 // Overload resolution is always an unevaluated context. 2597 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 2598 2599 // Add this candidate 2600 CandidateSet.push_back(OverloadCandidate()); 2601 OverloadCandidate& Candidate = CandidateSet.back(); 2602 Candidate.Function = Method; 2603 Candidate.Access = Access; 2604 Candidate.IsSurrogate = false; 2605 Candidate.IgnoreObjectArgument = false; 2606 2607 unsigned NumArgsInProto = Proto->getNumArgs(); 2608 2609 // (C++ 13.3.2p2): A candidate function having fewer than m 2610 // parameters is viable only if it has an ellipsis in its parameter 2611 // list (8.3.5). 2612 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 2613 Candidate.Viable = false; 2614 Candidate.FailureKind = ovl_fail_too_many_arguments; 2615 return; 2616 } 2617 2618 // (C++ 13.3.2p2): A candidate function having more than m parameters 2619 // is viable only if the (m+1)st parameter has a default argument 2620 // (8.3.6). For the purposes of overload resolution, the 2621 // parameter list is truncated on the right, so that there are 2622 // exactly m parameters. 2623 unsigned MinRequiredArgs = Method->getMinRequiredArguments(); 2624 if (NumArgs < MinRequiredArgs) { 2625 // Not enough arguments. 2626 Candidate.Viable = false; 2627 Candidate.FailureKind = ovl_fail_too_few_arguments; 2628 return; 2629 } 2630 2631 Candidate.Viable = true; 2632 Candidate.Conversions.resize(NumArgs + 1); 2633 2634 if (Method->isStatic() || ObjectType.isNull()) 2635 // The implicit object argument is ignored. 2636 Candidate.IgnoreObjectArgument = true; 2637 else { 2638 // Determine the implicit conversion sequence for the object 2639 // parameter. 2640 Candidate.Conversions[0] 2641 = TryObjectArgumentInitialization(ObjectType, Method, ActingContext); 2642 if (Candidate.Conversions[0].isBad()) { 2643 Candidate.Viable = false; 2644 Candidate.FailureKind = ovl_fail_bad_conversion; 2645 return; 2646 } 2647 } 2648 2649 // Determine the implicit conversion sequences for each of the 2650 // arguments. 2651 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2652 if (ArgIdx < NumArgsInProto) { 2653 // (C++ 13.3.2p3): for F to be a viable function, there shall 2654 // exist for each argument an implicit conversion sequence 2655 // (13.3.3.1) that converts that argument to the corresponding 2656 // parameter of F. 2657 QualType ParamType = Proto->getArgType(ArgIdx); 2658 Candidate.Conversions[ArgIdx + 1] 2659 = TryCopyInitialization(Args[ArgIdx], ParamType, 2660 SuppressUserConversions, ForceRValue, 2661 /*InOverloadResolution=*/true); 2662 if (Candidate.Conversions[ArgIdx + 1].isBad()) { 2663 Candidate.Viable = false; 2664 Candidate.FailureKind = ovl_fail_bad_conversion; 2665 break; 2666 } 2667 } else { 2668 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2669 // argument for which there is no corresponding parameter is 2670 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2671 Candidate.Conversions[ArgIdx + 1].setEllipsis(); 2672 } 2673 } 2674} 2675 2676/// \brief Add a C++ member function template as a candidate to the candidate 2677/// set, using template argument deduction to produce an appropriate member 2678/// function template specialization. 2679void 2680Sema::AddMethodTemplateCandidate(FunctionTemplateDecl *MethodTmpl, 2681 AccessSpecifier Access, 2682 CXXRecordDecl *ActingContext, 2683 const TemplateArgumentListInfo *ExplicitTemplateArgs, 2684 QualType ObjectType, 2685 Expr **Args, unsigned NumArgs, 2686 OverloadCandidateSet& CandidateSet, 2687 bool SuppressUserConversions, 2688 bool ForceRValue) { 2689 if (!CandidateSet.isNewCandidate(MethodTmpl)) 2690 return; 2691 2692 // C++ [over.match.funcs]p7: 2693 // In each case where a candidate is a function template, candidate 2694 // function template specializations are generated using template argument 2695 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 2696 // candidate functions in the usual way.113) A given name can refer to one 2697 // or more function templates and also to a set of overloaded non-template 2698 // functions. In such a case, the candidate functions generated from each 2699 // function template are combined with the set of non-template candidate 2700 // functions. 2701 TemplateDeductionInfo Info(Context, CandidateSet.getLocation()); 2702 FunctionDecl *Specialization = 0; 2703 if (TemplateDeductionResult Result 2704 = DeduceTemplateArguments(MethodTmpl, ExplicitTemplateArgs, 2705 Args, NumArgs, Specialization, Info)) { 2706 // FIXME: Record what happened with template argument deduction, so 2707 // that we can give the user a beautiful diagnostic. 2708 (void)Result; 2709 return; 2710 } 2711 2712 // Add the function template specialization produced by template argument 2713 // deduction as a candidate. 2714 assert(Specialization && "Missing member function template specialization?"); 2715 assert(isa<CXXMethodDecl>(Specialization) && 2716 "Specialization is not a member function?"); 2717 AddMethodCandidate(cast<CXXMethodDecl>(Specialization), Access, 2718 ActingContext, ObjectType, Args, NumArgs, 2719 CandidateSet, SuppressUserConversions, ForceRValue); 2720} 2721 2722/// \brief Add a C++ function template specialization as a candidate 2723/// in the candidate set, using template argument deduction to produce 2724/// an appropriate function template specialization. 2725void 2726Sema::AddTemplateOverloadCandidate(FunctionTemplateDecl *FunctionTemplate, 2727 AccessSpecifier Access, 2728 const TemplateArgumentListInfo *ExplicitTemplateArgs, 2729 Expr **Args, unsigned NumArgs, 2730 OverloadCandidateSet& CandidateSet, 2731 bool SuppressUserConversions, 2732 bool ForceRValue) { 2733 if (!CandidateSet.isNewCandidate(FunctionTemplate)) 2734 return; 2735 2736 // C++ [over.match.funcs]p7: 2737 // In each case where a candidate is a function template, candidate 2738 // function template specializations are generated using template argument 2739 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 2740 // candidate functions in the usual way.113) A given name can refer to one 2741 // or more function templates and also to a set of overloaded non-template 2742 // functions. In such a case, the candidate functions generated from each 2743 // function template are combined with the set of non-template candidate 2744 // functions. 2745 TemplateDeductionInfo Info(Context, CandidateSet.getLocation()); 2746 FunctionDecl *Specialization = 0; 2747 if (TemplateDeductionResult Result 2748 = DeduceTemplateArguments(FunctionTemplate, ExplicitTemplateArgs, 2749 Args, NumArgs, Specialization, Info)) { 2750 CandidateSet.push_back(OverloadCandidate()); 2751 OverloadCandidate &Candidate = CandidateSet.back(); 2752 Candidate.Function = FunctionTemplate->getTemplatedDecl(); 2753 Candidate.Access = Access; 2754 Candidate.Viable = false; 2755 Candidate.FailureKind = ovl_fail_bad_deduction; 2756 Candidate.IsSurrogate = false; 2757 Candidate.IgnoreObjectArgument = false; 2758 2759 // TODO: record more information about failed template arguments 2760 Candidate.DeductionFailure.Result = Result; 2761 Candidate.DeductionFailure.TemplateParameter = Info.Param.getOpaqueValue(); 2762 return; 2763 } 2764 2765 // Add the function template specialization produced by template argument 2766 // deduction as a candidate. 2767 assert(Specialization && "Missing function template specialization?"); 2768 AddOverloadCandidate(Specialization, Access, Args, NumArgs, CandidateSet, 2769 SuppressUserConversions, ForceRValue); 2770} 2771 2772/// AddConversionCandidate - Add a C++ conversion function as a 2773/// candidate in the candidate set (C++ [over.match.conv], 2774/// C++ [over.match.copy]). From is the expression we're converting from, 2775/// and ToType is the type that we're eventually trying to convert to 2776/// (which may or may not be the same type as the type that the 2777/// conversion function produces). 2778void 2779Sema::AddConversionCandidate(CXXConversionDecl *Conversion, 2780 AccessSpecifier Access, 2781 CXXRecordDecl *ActingContext, 2782 Expr *From, QualType ToType, 2783 OverloadCandidateSet& CandidateSet) { 2784 assert(!Conversion->getDescribedFunctionTemplate() && 2785 "Conversion function templates use AddTemplateConversionCandidate"); 2786 2787 if (!CandidateSet.isNewCandidate(Conversion)) 2788 return; 2789 2790 // Overload resolution is always an unevaluated context. 2791 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 2792 2793 // Add this candidate 2794 CandidateSet.push_back(OverloadCandidate()); 2795 OverloadCandidate& Candidate = CandidateSet.back(); 2796 Candidate.Function = Conversion; 2797 Candidate.Access = Access; 2798 Candidate.IsSurrogate = false; 2799 Candidate.IgnoreObjectArgument = false; 2800 Candidate.FinalConversion.setAsIdentityConversion(); 2801 Candidate.FinalConversion.setFromType(Conversion->getConversionType()); 2802 Candidate.FinalConversion.setAllToTypes(ToType); 2803 2804 // Determine the implicit conversion sequence for the implicit 2805 // object parameter. 2806 Candidate.Viable = true; 2807 Candidate.Conversions.resize(1); 2808 Candidate.Conversions[0] 2809 = TryObjectArgumentInitialization(From->getType(), Conversion, 2810 ActingContext); 2811 // Conversion functions to a different type in the base class is visible in 2812 // the derived class. So, a derived to base conversion should not participate 2813 // in overload resolution. 2814 if (Candidate.Conversions[0].Standard.Second == ICK_Derived_To_Base) 2815 Candidate.Conversions[0].Standard.Second = ICK_Identity; 2816 if (Candidate.Conversions[0].isBad()) { 2817 Candidate.Viable = false; 2818 Candidate.FailureKind = ovl_fail_bad_conversion; 2819 return; 2820 } 2821 2822 // We won't go through a user-define type conversion function to convert a 2823 // derived to base as such conversions are given Conversion Rank. They only 2824 // go through a copy constructor. 13.3.3.1.2-p4 [over.ics.user] 2825 QualType FromCanon 2826 = Context.getCanonicalType(From->getType().getUnqualifiedType()); 2827 QualType ToCanon = Context.getCanonicalType(ToType).getUnqualifiedType(); 2828 if (FromCanon == ToCanon || IsDerivedFrom(FromCanon, ToCanon)) { 2829 Candidate.Viable = false; 2830 Candidate.FailureKind = ovl_fail_trivial_conversion; 2831 return; 2832 } 2833 2834 2835 // To determine what the conversion from the result of calling the 2836 // conversion function to the type we're eventually trying to 2837 // convert to (ToType), we need to synthesize a call to the 2838 // conversion function and attempt copy initialization from it. This 2839 // makes sure that we get the right semantics with respect to 2840 // lvalues/rvalues and the type. Fortunately, we can allocate this 2841 // call on the stack and we don't need its arguments to be 2842 // well-formed. 2843 DeclRefExpr ConversionRef(Conversion, Conversion->getType(), 2844 From->getLocStart()); 2845 ImplicitCastExpr ConversionFn(Context.getPointerType(Conversion->getType()), 2846 CastExpr::CK_FunctionToPointerDecay, 2847 &ConversionRef, false); 2848 2849 // Note that it is safe to allocate CallExpr on the stack here because 2850 // there are 0 arguments (i.e., nothing is allocated using ASTContext's 2851 // allocator). 2852 CallExpr Call(Context, &ConversionFn, 0, 0, 2853 Conversion->getConversionType().getNonReferenceType(), 2854 From->getLocStart()); 2855 ImplicitConversionSequence ICS = 2856 TryCopyInitialization(&Call, ToType, 2857 /*SuppressUserConversions=*/true, 2858 /*ForceRValue=*/false, 2859 /*InOverloadResolution=*/false); 2860 2861 switch (ICS.getKind()) { 2862 case ImplicitConversionSequence::StandardConversion: 2863 Candidate.FinalConversion = ICS.Standard; 2864 break; 2865 2866 case ImplicitConversionSequence::BadConversion: 2867 Candidate.Viable = false; 2868 Candidate.FailureKind = ovl_fail_bad_final_conversion; 2869 break; 2870 2871 default: 2872 assert(false && 2873 "Can only end up with a standard conversion sequence or failure"); 2874 } 2875} 2876 2877/// \brief Adds a conversion function template specialization 2878/// candidate to the overload set, using template argument deduction 2879/// to deduce the template arguments of the conversion function 2880/// template from the type that we are converting to (C++ 2881/// [temp.deduct.conv]). 2882void 2883Sema::AddTemplateConversionCandidate(FunctionTemplateDecl *FunctionTemplate, 2884 AccessSpecifier Access, 2885 CXXRecordDecl *ActingDC, 2886 Expr *From, QualType ToType, 2887 OverloadCandidateSet &CandidateSet) { 2888 assert(isa<CXXConversionDecl>(FunctionTemplate->getTemplatedDecl()) && 2889 "Only conversion function templates permitted here"); 2890 2891 if (!CandidateSet.isNewCandidate(FunctionTemplate)) 2892 return; 2893 2894 TemplateDeductionInfo Info(Context, CandidateSet.getLocation()); 2895 CXXConversionDecl *Specialization = 0; 2896 if (TemplateDeductionResult Result 2897 = DeduceTemplateArguments(FunctionTemplate, ToType, 2898 Specialization, Info)) { 2899 // FIXME: Record what happened with template argument deduction, so 2900 // that we can give the user a beautiful diagnostic. 2901 (void)Result; 2902 return; 2903 } 2904 2905 // Add the conversion function template specialization produced by 2906 // template argument deduction as a candidate. 2907 assert(Specialization && "Missing function template specialization?"); 2908 AddConversionCandidate(Specialization, Access, ActingDC, From, ToType, 2909 CandidateSet); 2910} 2911 2912/// AddSurrogateCandidate - Adds a "surrogate" candidate function that 2913/// converts the given @c Object to a function pointer via the 2914/// conversion function @c Conversion, and then attempts to call it 2915/// with the given arguments (C++ [over.call.object]p2-4). Proto is 2916/// the type of function that we'll eventually be calling. 2917void Sema::AddSurrogateCandidate(CXXConversionDecl *Conversion, 2918 AccessSpecifier Access, 2919 CXXRecordDecl *ActingContext, 2920 const FunctionProtoType *Proto, 2921 QualType ObjectType, 2922 Expr **Args, unsigned NumArgs, 2923 OverloadCandidateSet& CandidateSet) { 2924 if (!CandidateSet.isNewCandidate(Conversion)) 2925 return; 2926 2927 // Overload resolution is always an unevaluated context. 2928 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 2929 2930 CandidateSet.push_back(OverloadCandidate()); 2931 OverloadCandidate& Candidate = CandidateSet.back(); 2932 Candidate.Function = 0; 2933 Candidate.Access = Access; 2934 Candidate.Surrogate = Conversion; 2935 Candidate.Viable = true; 2936 Candidate.IsSurrogate = true; 2937 Candidate.IgnoreObjectArgument = false; 2938 Candidate.Conversions.resize(NumArgs + 1); 2939 2940 // Determine the implicit conversion sequence for the implicit 2941 // object parameter. 2942 ImplicitConversionSequence ObjectInit 2943 = TryObjectArgumentInitialization(ObjectType, Conversion, ActingContext); 2944 if (ObjectInit.isBad()) { 2945 Candidate.Viable = false; 2946 Candidate.FailureKind = ovl_fail_bad_conversion; 2947 Candidate.Conversions[0] = ObjectInit; 2948 return; 2949 } 2950 2951 // The first conversion is actually a user-defined conversion whose 2952 // first conversion is ObjectInit's standard conversion (which is 2953 // effectively a reference binding). Record it as such. 2954 Candidate.Conversions[0].setUserDefined(); 2955 Candidate.Conversions[0].UserDefined.Before = ObjectInit.Standard; 2956 Candidate.Conversions[0].UserDefined.EllipsisConversion = false; 2957 Candidate.Conversions[0].UserDefined.ConversionFunction = Conversion; 2958 Candidate.Conversions[0].UserDefined.After 2959 = Candidate.Conversions[0].UserDefined.Before; 2960 Candidate.Conversions[0].UserDefined.After.setAsIdentityConversion(); 2961 2962 // Find the 2963 unsigned NumArgsInProto = Proto->getNumArgs(); 2964 2965 // (C++ 13.3.2p2): A candidate function having fewer than m 2966 // parameters is viable only if it has an ellipsis in its parameter 2967 // list (8.3.5). 2968 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 2969 Candidate.Viable = false; 2970 Candidate.FailureKind = ovl_fail_too_many_arguments; 2971 return; 2972 } 2973 2974 // Function types don't have any default arguments, so just check if 2975 // we have enough arguments. 2976 if (NumArgs < NumArgsInProto) { 2977 // Not enough arguments. 2978 Candidate.Viable = false; 2979 Candidate.FailureKind = ovl_fail_too_few_arguments; 2980 return; 2981 } 2982 2983 // Determine the implicit conversion sequences for each of the 2984 // arguments. 2985 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2986 if (ArgIdx < NumArgsInProto) { 2987 // (C++ 13.3.2p3): for F to be a viable function, there shall 2988 // exist for each argument an implicit conversion sequence 2989 // (13.3.3.1) that converts that argument to the corresponding 2990 // parameter of F. 2991 QualType ParamType = Proto->getArgType(ArgIdx); 2992 Candidate.Conversions[ArgIdx + 1] 2993 = TryCopyInitialization(Args[ArgIdx], ParamType, 2994 /*SuppressUserConversions=*/false, 2995 /*ForceRValue=*/false, 2996 /*InOverloadResolution=*/false); 2997 if (Candidate.Conversions[ArgIdx + 1].isBad()) { 2998 Candidate.Viable = false; 2999 Candidate.FailureKind = ovl_fail_bad_conversion; 3000 break; 3001 } 3002 } else { 3003 // (C++ 13.3.2p2): For the purposes of overload resolution, any 3004 // argument for which there is no corresponding parameter is 3005 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 3006 Candidate.Conversions[ArgIdx + 1].setEllipsis(); 3007 } 3008 } 3009} 3010 3011// FIXME: This will eventually be removed, once we've migrated all of the 3012// operator overloading logic over to the scheme used by binary operators, which 3013// works for template instantiation. 3014void Sema::AddOperatorCandidates(OverloadedOperatorKind Op, Scope *S, 3015 SourceLocation OpLoc, 3016 Expr **Args, unsigned NumArgs, 3017 OverloadCandidateSet& CandidateSet, 3018 SourceRange OpRange) { 3019 UnresolvedSet<16> Fns; 3020 3021 QualType T1 = Args[0]->getType(); 3022 QualType T2; 3023 if (NumArgs > 1) 3024 T2 = Args[1]->getType(); 3025 3026 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 3027 if (S) 3028 LookupOverloadedOperatorName(Op, S, T1, T2, Fns); 3029 AddFunctionCandidates(Fns, Args, NumArgs, CandidateSet, false); 3030 AddArgumentDependentLookupCandidates(OpName, false, Args, NumArgs, 0, 3031 CandidateSet); 3032 AddMemberOperatorCandidates(Op, OpLoc, Args, NumArgs, CandidateSet, OpRange); 3033 AddBuiltinOperatorCandidates(Op, OpLoc, Args, NumArgs, CandidateSet); 3034} 3035 3036/// \brief Add overload candidates for overloaded operators that are 3037/// member functions. 3038/// 3039/// Add the overloaded operator candidates that are member functions 3040/// for the operator Op that was used in an operator expression such 3041/// as "x Op y". , Args/NumArgs provides the operator arguments, and 3042/// CandidateSet will store the added overload candidates. (C++ 3043/// [over.match.oper]). 3044void Sema::AddMemberOperatorCandidates(OverloadedOperatorKind Op, 3045 SourceLocation OpLoc, 3046 Expr **Args, unsigned NumArgs, 3047 OverloadCandidateSet& CandidateSet, 3048 SourceRange OpRange) { 3049 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 3050 3051 // C++ [over.match.oper]p3: 3052 // For a unary operator @ with an operand of a type whose 3053 // cv-unqualified version is T1, and for a binary operator @ with 3054 // a left operand of a type whose cv-unqualified version is T1 and 3055 // a right operand of a type whose cv-unqualified version is T2, 3056 // three sets of candidate functions, designated member 3057 // candidates, non-member candidates and built-in candidates, are 3058 // constructed as follows: 3059 QualType T1 = Args[0]->getType(); 3060 QualType T2; 3061 if (NumArgs > 1) 3062 T2 = Args[1]->getType(); 3063 3064 // -- If T1 is a class type, the set of member candidates is the 3065 // result of the qualified lookup of T1::operator@ 3066 // (13.3.1.1.1); otherwise, the set of member candidates is 3067 // empty. 3068 if (const RecordType *T1Rec = T1->getAs<RecordType>()) { 3069 // Complete the type if it can be completed. Otherwise, we're done. 3070 if (RequireCompleteType(OpLoc, T1, PDiag())) 3071 return; 3072 3073 LookupResult Operators(*this, OpName, OpLoc, LookupOrdinaryName); 3074 LookupQualifiedName(Operators, T1Rec->getDecl()); 3075 Operators.suppressDiagnostics(); 3076 3077 for (LookupResult::iterator Oper = Operators.begin(), 3078 OperEnd = Operators.end(); 3079 Oper != OperEnd; 3080 ++Oper) 3081 AddMethodCandidate(*Oper, Oper.getAccess(), Args[0]->getType(), 3082 Args + 1, NumArgs - 1, CandidateSet, 3083 /* SuppressUserConversions = */ false); 3084 } 3085} 3086 3087/// AddBuiltinCandidate - Add a candidate for a built-in 3088/// operator. ResultTy and ParamTys are the result and parameter types 3089/// of the built-in candidate, respectively. Args and NumArgs are the 3090/// arguments being passed to the candidate. IsAssignmentOperator 3091/// should be true when this built-in candidate is an assignment 3092/// operator. NumContextualBoolArguments is the number of arguments 3093/// (at the beginning of the argument list) that will be contextually 3094/// converted to bool. 3095void Sema::AddBuiltinCandidate(QualType ResultTy, QualType *ParamTys, 3096 Expr **Args, unsigned NumArgs, 3097 OverloadCandidateSet& CandidateSet, 3098 bool IsAssignmentOperator, 3099 unsigned NumContextualBoolArguments) { 3100 // Overload resolution is always an unevaluated context. 3101 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 3102 3103 // Add this candidate 3104 CandidateSet.push_back(OverloadCandidate()); 3105 OverloadCandidate& Candidate = CandidateSet.back(); 3106 Candidate.Function = 0; 3107 Candidate.Access = AS_none; 3108 Candidate.IsSurrogate = false; 3109 Candidate.IgnoreObjectArgument = false; 3110 Candidate.BuiltinTypes.ResultTy = ResultTy; 3111 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 3112 Candidate.BuiltinTypes.ParamTypes[ArgIdx] = ParamTys[ArgIdx]; 3113 3114 // Determine the implicit conversion sequences for each of the 3115 // arguments. 3116 Candidate.Viable = true; 3117 Candidate.Conversions.resize(NumArgs); 3118 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 3119 // C++ [over.match.oper]p4: 3120 // For the built-in assignment operators, conversions of the 3121 // left operand are restricted as follows: 3122 // -- no temporaries are introduced to hold the left operand, and 3123 // -- no user-defined conversions are applied to the left 3124 // operand to achieve a type match with the left-most 3125 // parameter of a built-in candidate. 3126 // 3127 // We block these conversions by turning off user-defined 3128 // conversions, since that is the only way that initialization of 3129 // a reference to a non-class type can occur from something that 3130 // is not of the same type. 3131 if (ArgIdx < NumContextualBoolArguments) { 3132 assert(ParamTys[ArgIdx] == Context.BoolTy && 3133 "Contextual conversion to bool requires bool type"); 3134 Candidate.Conversions[ArgIdx] = TryContextuallyConvertToBool(Args[ArgIdx]); 3135 } else { 3136 Candidate.Conversions[ArgIdx] 3137 = TryCopyInitialization(Args[ArgIdx], ParamTys[ArgIdx], 3138 ArgIdx == 0 && IsAssignmentOperator, 3139 /*ForceRValue=*/false, 3140 /*InOverloadResolution=*/false); 3141 } 3142 if (Candidate.Conversions[ArgIdx].isBad()) { 3143 Candidate.Viable = false; 3144 Candidate.FailureKind = ovl_fail_bad_conversion; 3145 break; 3146 } 3147 } 3148} 3149 3150/// BuiltinCandidateTypeSet - A set of types that will be used for the 3151/// candidate operator functions for built-in operators (C++ 3152/// [over.built]). The types are separated into pointer types and 3153/// enumeration types. 3154class BuiltinCandidateTypeSet { 3155 /// TypeSet - A set of types. 3156 typedef llvm::SmallPtrSet<QualType, 8> TypeSet; 3157 3158 /// PointerTypes - The set of pointer types that will be used in the 3159 /// built-in candidates. 3160 TypeSet PointerTypes; 3161 3162 /// MemberPointerTypes - The set of member pointer types that will be 3163 /// used in the built-in candidates. 3164 TypeSet MemberPointerTypes; 3165 3166 /// EnumerationTypes - The set of enumeration types that will be 3167 /// used in the built-in candidates. 3168 TypeSet EnumerationTypes; 3169 3170 /// Sema - The semantic analysis instance where we are building the 3171 /// candidate type set. 3172 Sema &SemaRef; 3173 3174 /// Context - The AST context in which we will build the type sets. 3175 ASTContext &Context; 3176 3177 bool AddPointerWithMoreQualifiedTypeVariants(QualType Ty, 3178 const Qualifiers &VisibleQuals); 3179 bool AddMemberPointerWithMoreQualifiedTypeVariants(QualType Ty); 3180 3181public: 3182 /// iterator - Iterates through the types that are part of the set. 3183 typedef TypeSet::iterator iterator; 3184 3185 BuiltinCandidateTypeSet(Sema &SemaRef) 3186 : SemaRef(SemaRef), Context(SemaRef.Context) { } 3187 3188 void AddTypesConvertedFrom(QualType Ty, 3189 SourceLocation Loc, 3190 bool AllowUserConversions, 3191 bool AllowExplicitConversions, 3192 const Qualifiers &VisibleTypeConversionsQuals); 3193 3194 /// pointer_begin - First pointer type found; 3195 iterator pointer_begin() { return PointerTypes.begin(); } 3196 3197 /// pointer_end - Past the last pointer type found; 3198 iterator pointer_end() { return PointerTypes.end(); } 3199 3200 /// member_pointer_begin - First member pointer type found; 3201 iterator member_pointer_begin() { return MemberPointerTypes.begin(); } 3202 3203 /// member_pointer_end - Past the last member pointer type found; 3204 iterator member_pointer_end() { return MemberPointerTypes.end(); } 3205 3206 /// enumeration_begin - First enumeration type found; 3207 iterator enumeration_begin() { return EnumerationTypes.begin(); } 3208 3209 /// enumeration_end - Past the last enumeration type found; 3210 iterator enumeration_end() { return EnumerationTypes.end(); } 3211}; 3212 3213/// AddPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty to 3214/// the set of pointer types along with any more-qualified variants of 3215/// that type. For example, if @p Ty is "int const *", this routine 3216/// will add "int const *", "int const volatile *", "int const 3217/// restrict *", and "int const volatile restrict *" to the set of 3218/// pointer types. Returns true if the add of @p Ty itself succeeded, 3219/// false otherwise. 3220/// 3221/// FIXME: what to do about extended qualifiers? 3222bool 3223BuiltinCandidateTypeSet::AddPointerWithMoreQualifiedTypeVariants(QualType Ty, 3224 const Qualifiers &VisibleQuals) { 3225 3226 // Insert this type. 3227 if (!PointerTypes.insert(Ty)) 3228 return false; 3229 3230 const PointerType *PointerTy = Ty->getAs<PointerType>(); 3231 assert(PointerTy && "type was not a pointer type!"); 3232 3233 QualType PointeeTy = PointerTy->getPointeeType(); 3234 // Don't add qualified variants of arrays. For one, they're not allowed 3235 // (the qualifier would sink to the element type), and for another, the 3236 // only overload situation where it matters is subscript or pointer +- int, 3237 // and those shouldn't have qualifier variants anyway. 3238 if (PointeeTy->isArrayType()) 3239 return true; 3240 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 3241 if (const ConstantArrayType *Array =Context.getAsConstantArrayType(PointeeTy)) 3242 BaseCVR = Array->getElementType().getCVRQualifiers(); 3243 bool hasVolatile = VisibleQuals.hasVolatile(); 3244 bool hasRestrict = VisibleQuals.hasRestrict(); 3245 3246 // Iterate through all strict supersets of BaseCVR. 3247 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 3248 if ((CVR | BaseCVR) != CVR) continue; 3249 // Skip over Volatile/Restrict if no Volatile/Restrict found anywhere 3250 // in the types. 3251 if ((CVR & Qualifiers::Volatile) && !hasVolatile) continue; 3252 if ((CVR & Qualifiers::Restrict) && !hasRestrict) continue; 3253 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 3254 PointerTypes.insert(Context.getPointerType(QPointeeTy)); 3255 } 3256 3257 return true; 3258} 3259 3260/// AddMemberPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty 3261/// to the set of pointer types along with any more-qualified variants of 3262/// that type. For example, if @p Ty is "int const *", this routine 3263/// will add "int const *", "int const volatile *", "int const 3264/// restrict *", and "int const volatile restrict *" to the set of 3265/// pointer types. Returns true if the add of @p Ty itself succeeded, 3266/// false otherwise. 3267/// 3268/// FIXME: what to do about extended qualifiers? 3269bool 3270BuiltinCandidateTypeSet::AddMemberPointerWithMoreQualifiedTypeVariants( 3271 QualType Ty) { 3272 // Insert this type. 3273 if (!MemberPointerTypes.insert(Ty)) 3274 return false; 3275 3276 const MemberPointerType *PointerTy = Ty->getAs<MemberPointerType>(); 3277 assert(PointerTy && "type was not a member pointer type!"); 3278 3279 QualType PointeeTy = PointerTy->getPointeeType(); 3280 // Don't add qualified variants of arrays. For one, they're not allowed 3281 // (the qualifier would sink to the element type), and for another, the 3282 // only overload situation where it matters is subscript or pointer +- int, 3283 // and those shouldn't have qualifier variants anyway. 3284 if (PointeeTy->isArrayType()) 3285 return true; 3286 const Type *ClassTy = PointerTy->getClass(); 3287 3288 // Iterate through all strict supersets of the pointee type's CVR 3289 // qualifiers. 3290 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 3291 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 3292 if ((CVR | BaseCVR) != CVR) continue; 3293 3294 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 3295 MemberPointerTypes.insert(Context.getMemberPointerType(QPointeeTy, ClassTy)); 3296 } 3297 3298 return true; 3299} 3300 3301/// AddTypesConvertedFrom - Add each of the types to which the type @p 3302/// Ty can be implicit converted to the given set of @p Types. We're 3303/// primarily interested in pointer types and enumeration types. We also 3304/// take member pointer types, for the conditional operator. 3305/// AllowUserConversions is true if we should look at the conversion 3306/// functions of a class type, and AllowExplicitConversions if we 3307/// should also include the explicit conversion functions of a class 3308/// type. 3309void 3310BuiltinCandidateTypeSet::AddTypesConvertedFrom(QualType Ty, 3311 SourceLocation Loc, 3312 bool AllowUserConversions, 3313 bool AllowExplicitConversions, 3314 const Qualifiers &VisibleQuals) { 3315 // Only deal with canonical types. 3316 Ty = Context.getCanonicalType(Ty); 3317 3318 // Look through reference types; they aren't part of the type of an 3319 // expression for the purposes of conversions. 3320 if (const ReferenceType *RefTy = Ty->getAs<ReferenceType>()) 3321 Ty = RefTy->getPointeeType(); 3322 3323 // We don't care about qualifiers on the type. 3324 Ty = Ty.getLocalUnqualifiedType(); 3325 3326 // If we're dealing with an array type, decay to the pointer. 3327 if (Ty->isArrayType()) 3328 Ty = SemaRef.Context.getArrayDecayedType(Ty); 3329 3330 if (const PointerType *PointerTy = Ty->getAs<PointerType>()) { 3331 QualType PointeeTy = PointerTy->getPointeeType(); 3332 3333 // Insert our type, and its more-qualified variants, into the set 3334 // of types. 3335 if (!AddPointerWithMoreQualifiedTypeVariants(Ty, VisibleQuals)) 3336 return; 3337 } else if (Ty->isMemberPointerType()) { 3338 // Member pointers are far easier, since the pointee can't be converted. 3339 if (!AddMemberPointerWithMoreQualifiedTypeVariants(Ty)) 3340 return; 3341 } else if (Ty->isEnumeralType()) { 3342 EnumerationTypes.insert(Ty); 3343 } else if (AllowUserConversions) { 3344 if (const RecordType *TyRec = Ty->getAs<RecordType>()) { 3345 if (SemaRef.RequireCompleteType(Loc, Ty, 0)) { 3346 // No conversion functions in incomplete types. 3347 return; 3348 } 3349 3350 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 3351 const UnresolvedSetImpl *Conversions 3352 = ClassDecl->getVisibleConversionFunctions(); 3353 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 3354 E = Conversions->end(); I != E; ++I) { 3355 3356 // Skip conversion function templates; they don't tell us anything 3357 // about which builtin types we can convert to. 3358 if (isa<FunctionTemplateDecl>(*I)) 3359 continue; 3360 3361 CXXConversionDecl *Conv = cast<CXXConversionDecl>(*I); 3362 if (AllowExplicitConversions || !Conv->isExplicit()) { 3363 AddTypesConvertedFrom(Conv->getConversionType(), Loc, false, false, 3364 VisibleQuals); 3365 } 3366 } 3367 } 3368 } 3369} 3370 3371/// \brief Helper function for AddBuiltinOperatorCandidates() that adds 3372/// the volatile- and non-volatile-qualified assignment operators for the 3373/// given type to the candidate set. 3374static void AddBuiltinAssignmentOperatorCandidates(Sema &S, 3375 QualType T, 3376 Expr **Args, 3377 unsigned NumArgs, 3378 OverloadCandidateSet &CandidateSet) { 3379 QualType ParamTypes[2]; 3380 3381 // T& operator=(T&, T) 3382 ParamTypes[0] = S.Context.getLValueReferenceType(T); 3383 ParamTypes[1] = T; 3384 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3385 /*IsAssignmentOperator=*/true); 3386 3387 if (!S.Context.getCanonicalType(T).isVolatileQualified()) { 3388 // volatile T& operator=(volatile T&, T) 3389 ParamTypes[0] 3390 = S.Context.getLValueReferenceType(S.Context.getVolatileType(T)); 3391 ParamTypes[1] = T; 3392 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3393 /*IsAssignmentOperator=*/true); 3394 } 3395} 3396 3397/// CollectVRQualifiers - This routine returns Volatile/Restrict qualifiers, 3398/// if any, found in visible type conversion functions found in ArgExpr's type. 3399static Qualifiers CollectVRQualifiers(ASTContext &Context, Expr* ArgExpr) { 3400 Qualifiers VRQuals; 3401 const RecordType *TyRec; 3402 if (const MemberPointerType *RHSMPType = 3403 ArgExpr->getType()->getAs<MemberPointerType>()) 3404 TyRec = cast<RecordType>(RHSMPType->getClass()); 3405 else 3406 TyRec = ArgExpr->getType()->getAs<RecordType>(); 3407 if (!TyRec) { 3408 // Just to be safe, assume the worst case. 3409 VRQuals.addVolatile(); 3410 VRQuals.addRestrict(); 3411 return VRQuals; 3412 } 3413 3414 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 3415 if (!ClassDecl->hasDefinition()) 3416 return VRQuals; 3417 3418 const UnresolvedSetImpl *Conversions = 3419 ClassDecl->getVisibleConversionFunctions(); 3420 3421 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 3422 E = Conversions->end(); I != E; ++I) { 3423 if (CXXConversionDecl *Conv = dyn_cast<CXXConversionDecl>(*I)) { 3424 QualType CanTy = Context.getCanonicalType(Conv->getConversionType()); 3425 if (const ReferenceType *ResTypeRef = CanTy->getAs<ReferenceType>()) 3426 CanTy = ResTypeRef->getPointeeType(); 3427 // Need to go down the pointer/mempointer chain and add qualifiers 3428 // as see them. 3429 bool done = false; 3430 while (!done) { 3431 if (const PointerType *ResTypePtr = CanTy->getAs<PointerType>()) 3432 CanTy = ResTypePtr->getPointeeType(); 3433 else if (const MemberPointerType *ResTypeMPtr = 3434 CanTy->getAs<MemberPointerType>()) 3435 CanTy = ResTypeMPtr->getPointeeType(); 3436 else 3437 done = true; 3438 if (CanTy.isVolatileQualified()) 3439 VRQuals.addVolatile(); 3440 if (CanTy.isRestrictQualified()) 3441 VRQuals.addRestrict(); 3442 if (VRQuals.hasRestrict() && VRQuals.hasVolatile()) 3443 return VRQuals; 3444 } 3445 } 3446 } 3447 return VRQuals; 3448} 3449 3450/// AddBuiltinOperatorCandidates - Add the appropriate built-in 3451/// operator overloads to the candidate set (C++ [over.built]), based 3452/// on the operator @p Op and the arguments given. For example, if the 3453/// operator is a binary '+', this routine might add "int 3454/// operator+(int, int)" to cover integer addition. 3455void 3456Sema::AddBuiltinOperatorCandidates(OverloadedOperatorKind Op, 3457 SourceLocation OpLoc, 3458 Expr **Args, unsigned NumArgs, 3459 OverloadCandidateSet& CandidateSet) { 3460 // The set of "promoted arithmetic types", which are the arithmetic 3461 // types are that preserved by promotion (C++ [over.built]p2). Note 3462 // that the first few of these types are the promoted integral 3463 // types; these types need to be first. 3464 // FIXME: What about complex? 3465 const unsigned FirstIntegralType = 0; 3466 const unsigned LastIntegralType = 13; 3467 const unsigned FirstPromotedIntegralType = 7, 3468 LastPromotedIntegralType = 13; 3469 const unsigned FirstPromotedArithmeticType = 7, 3470 LastPromotedArithmeticType = 16; 3471 const unsigned NumArithmeticTypes = 16; 3472 QualType ArithmeticTypes[NumArithmeticTypes] = { 3473 Context.BoolTy, Context.CharTy, Context.WCharTy, 3474// FIXME: Context.Char16Ty, Context.Char32Ty, 3475 Context.SignedCharTy, Context.ShortTy, 3476 Context.UnsignedCharTy, Context.UnsignedShortTy, 3477 Context.IntTy, Context.LongTy, Context.LongLongTy, 3478 Context.UnsignedIntTy, Context.UnsignedLongTy, Context.UnsignedLongLongTy, 3479 Context.FloatTy, Context.DoubleTy, Context.LongDoubleTy 3480 }; 3481 assert(ArithmeticTypes[FirstPromotedIntegralType] == Context.IntTy && 3482 "Invalid first promoted integral type"); 3483 assert(ArithmeticTypes[LastPromotedIntegralType - 1] 3484 == Context.UnsignedLongLongTy && 3485 "Invalid last promoted integral type"); 3486 assert(ArithmeticTypes[FirstPromotedArithmeticType] == Context.IntTy && 3487 "Invalid first promoted arithmetic type"); 3488 assert(ArithmeticTypes[LastPromotedArithmeticType - 1] 3489 == Context.LongDoubleTy && 3490 "Invalid last promoted arithmetic type"); 3491 3492 // Find all of the types that the arguments can convert to, but only 3493 // if the operator we're looking at has built-in operator candidates 3494 // that make use of these types. 3495 Qualifiers VisibleTypeConversionsQuals; 3496 VisibleTypeConversionsQuals.addConst(); 3497 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 3498 VisibleTypeConversionsQuals += CollectVRQualifiers(Context, Args[ArgIdx]); 3499 3500 BuiltinCandidateTypeSet CandidateTypes(*this); 3501 if (Op == OO_Less || Op == OO_Greater || Op == OO_LessEqual || 3502 Op == OO_GreaterEqual || Op == OO_EqualEqual || Op == OO_ExclaimEqual || 3503 Op == OO_Plus || (Op == OO_Minus && NumArgs == 2) || Op == OO_Equal || 3504 Op == OO_PlusEqual || Op == OO_MinusEqual || Op == OO_Subscript || 3505 Op == OO_ArrowStar || Op == OO_PlusPlus || Op == OO_MinusMinus || 3506 (Op == OO_Star && NumArgs == 1) || Op == OO_Conditional) { 3507 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 3508 CandidateTypes.AddTypesConvertedFrom(Args[ArgIdx]->getType(), 3509 OpLoc, 3510 true, 3511 (Op == OO_Exclaim || 3512 Op == OO_AmpAmp || 3513 Op == OO_PipePipe), 3514 VisibleTypeConversionsQuals); 3515 } 3516 3517 bool isComparison = false; 3518 switch (Op) { 3519 case OO_None: 3520 case NUM_OVERLOADED_OPERATORS: 3521 assert(false && "Expected an overloaded operator"); 3522 break; 3523 3524 case OO_Star: // '*' is either unary or binary 3525 if (NumArgs == 1) 3526 goto UnaryStar; 3527 else 3528 goto BinaryStar; 3529 break; 3530 3531 case OO_Plus: // '+' is either unary or binary 3532 if (NumArgs == 1) 3533 goto UnaryPlus; 3534 else 3535 goto BinaryPlus; 3536 break; 3537 3538 case OO_Minus: // '-' is either unary or binary 3539 if (NumArgs == 1) 3540 goto UnaryMinus; 3541 else 3542 goto BinaryMinus; 3543 break; 3544 3545 case OO_Amp: // '&' is either unary or binary 3546 if (NumArgs == 1) 3547 goto UnaryAmp; 3548 else 3549 goto BinaryAmp; 3550 3551 case OO_PlusPlus: 3552 case OO_MinusMinus: 3553 // C++ [over.built]p3: 3554 // 3555 // For every pair (T, VQ), where T is an arithmetic type, and VQ 3556 // is either volatile or empty, there exist candidate operator 3557 // functions of the form 3558 // 3559 // VQ T& operator++(VQ T&); 3560 // T operator++(VQ T&, int); 3561 // 3562 // C++ [over.built]p4: 3563 // 3564 // For every pair (T, VQ), where T is an arithmetic type other 3565 // than bool, and VQ is either volatile or empty, there exist 3566 // candidate operator functions of the form 3567 // 3568 // VQ T& operator--(VQ T&); 3569 // T operator--(VQ T&, int); 3570 for (unsigned Arith = (Op == OO_PlusPlus? 0 : 1); 3571 Arith < NumArithmeticTypes; ++Arith) { 3572 QualType ArithTy = ArithmeticTypes[Arith]; 3573 QualType ParamTypes[2] 3574 = { Context.getLValueReferenceType(ArithTy), Context.IntTy }; 3575 3576 // Non-volatile version. 3577 if (NumArgs == 1) 3578 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3579 else 3580 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 3581 // heuristic to reduce number of builtin candidates in the set. 3582 // Add volatile version only if there are conversions to a volatile type. 3583 if (VisibleTypeConversionsQuals.hasVolatile()) { 3584 // Volatile version 3585 ParamTypes[0] 3586 = Context.getLValueReferenceType(Context.getVolatileType(ArithTy)); 3587 if (NumArgs == 1) 3588 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3589 else 3590 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 3591 } 3592 } 3593 3594 // C++ [over.built]p5: 3595 // 3596 // For every pair (T, VQ), where T is a cv-qualified or 3597 // cv-unqualified object type, and VQ is either volatile or 3598 // empty, there exist candidate operator functions of the form 3599 // 3600 // T*VQ& operator++(T*VQ&); 3601 // T*VQ& operator--(T*VQ&); 3602 // T* operator++(T*VQ&, int); 3603 // T* operator--(T*VQ&, int); 3604 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3605 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3606 // Skip pointer types that aren't pointers to object types. 3607 if (!(*Ptr)->getAs<PointerType>()->getPointeeType()->isObjectType()) 3608 continue; 3609 3610 QualType ParamTypes[2] = { 3611 Context.getLValueReferenceType(*Ptr), Context.IntTy 3612 }; 3613 3614 // Without volatile 3615 if (NumArgs == 1) 3616 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3617 else 3618 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3619 3620 if (!Context.getCanonicalType(*Ptr).isVolatileQualified() && 3621 VisibleTypeConversionsQuals.hasVolatile()) { 3622 // With volatile 3623 ParamTypes[0] 3624 = Context.getLValueReferenceType(Context.getVolatileType(*Ptr)); 3625 if (NumArgs == 1) 3626 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3627 else 3628 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3629 } 3630 } 3631 break; 3632 3633 UnaryStar: 3634 // C++ [over.built]p6: 3635 // For every cv-qualified or cv-unqualified object type T, there 3636 // exist candidate operator functions of the form 3637 // 3638 // T& operator*(T*); 3639 // 3640 // C++ [over.built]p7: 3641 // For every function type T, there exist candidate operator 3642 // functions of the form 3643 // T& operator*(T*); 3644 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3645 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3646 QualType ParamTy = *Ptr; 3647 QualType PointeeTy = ParamTy->getAs<PointerType>()->getPointeeType(); 3648 AddBuiltinCandidate(Context.getLValueReferenceType(PointeeTy), 3649 &ParamTy, Args, 1, CandidateSet); 3650 } 3651 break; 3652 3653 UnaryPlus: 3654 // C++ [over.built]p8: 3655 // For every type T, there exist candidate operator functions of 3656 // the form 3657 // 3658 // T* operator+(T*); 3659 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3660 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3661 QualType ParamTy = *Ptr; 3662 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet); 3663 } 3664 3665 // Fall through 3666 3667 UnaryMinus: 3668 // C++ [over.built]p9: 3669 // For every promoted arithmetic type T, there exist candidate 3670 // operator functions of the form 3671 // 3672 // T operator+(T); 3673 // T operator-(T); 3674 for (unsigned Arith = FirstPromotedArithmeticType; 3675 Arith < LastPromotedArithmeticType; ++Arith) { 3676 QualType ArithTy = ArithmeticTypes[Arith]; 3677 AddBuiltinCandidate(ArithTy, &ArithTy, Args, 1, CandidateSet); 3678 } 3679 break; 3680 3681 case OO_Tilde: 3682 // C++ [over.built]p10: 3683 // For every promoted integral type T, there exist candidate 3684 // operator functions of the form 3685 // 3686 // T operator~(T); 3687 for (unsigned Int = FirstPromotedIntegralType; 3688 Int < LastPromotedIntegralType; ++Int) { 3689 QualType IntTy = ArithmeticTypes[Int]; 3690 AddBuiltinCandidate(IntTy, &IntTy, Args, 1, CandidateSet); 3691 } 3692 break; 3693 3694 case OO_New: 3695 case OO_Delete: 3696 case OO_Array_New: 3697 case OO_Array_Delete: 3698 case OO_Call: 3699 assert(false && "Special operators don't use AddBuiltinOperatorCandidates"); 3700 break; 3701 3702 case OO_Comma: 3703 UnaryAmp: 3704 case OO_Arrow: 3705 // C++ [over.match.oper]p3: 3706 // -- For the operator ',', the unary operator '&', or the 3707 // operator '->', the built-in candidates set is empty. 3708 break; 3709 3710 case OO_EqualEqual: 3711 case OO_ExclaimEqual: 3712 // C++ [over.match.oper]p16: 3713 // For every pointer to member type T, there exist candidate operator 3714 // functions of the form 3715 // 3716 // bool operator==(T,T); 3717 // bool operator!=(T,T); 3718 for (BuiltinCandidateTypeSet::iterator 3719 MemPtr = CandidateTypes.member_pointer_begin(), 3720 MemPtrEnd = CandidateTypes.member_pointer_end(); 3721 MemPtr != MemPtrEnd; 3722 ++MemPtr) { 3723 QualType ParamTypes[2] = { *MemPtr, *MemPtr }; 3724 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 3725 } 3726 3727 // Fall through 3728 3729 case OO_Less: 3730 case OO_Greater: 3731 case OO_LessEqual: 3732 case OO_GreaterEqual: 3733 // C++ [over.built]p15: 3734 // 3735 // For every pointer or enumeration type T, there exist 3736 // candidate operator functions of the form 3737 // 3738 // bool operator<(T, T); 3739 // bool operator>(T, T); 3740 // bool operator<=(T, T); 3741 // bool operator>=(T, T); 3742 // bool operator==(T, T); 3743 // bool operator!=(T, T); 3744 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3745 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3746 QualType ParamTypes[2] = { *Ptr, *Ptr }; 3747 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 3748 } 3749 for (BuiltinCandidateTypeSet::iterator Enum 3750 = CandidateTypes.enumeration_begin(); 3751 Enum != CandidateTypes.enumeration_end(); ++Enum) { 3752 QualType ParamTypes[2] = { *Enum, *Enum }; 3753 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 3754 } 3755 3756 // Fall through. 3757 isComparison = true; 3758 3759 BinaryPlus: 3760 BinaryMinus: 3761 if (!isComparison) { 3762 // We didn't fall through, so we must have OO_Plus or OO_Minus. 3763 3764 // C++ [over.built]p13: 3765 // 3766 // For every cv-qualified or cv-unqualified object type T 3767 // there exist candidate operator functions of the form 3768 // 3769 // T* operator+(T*, ptrdiff_t); 3770 // T& operator[](T*, ptrdiff_t); [BELOW] 3771 // T* operator-(T*, ptrdiff_t); 3772 // T* operator+(ptrdiff_t, T*); 3773 // T& operator[](ptrdiff_t, T*); [BELOW] 3774 // 3775 // C++ [over.built]p14: 3776 // 3777 // For every T, where T is a pointer to object type, there 3778 // exist candidate operator functions of the form 3779 // 3780 // ptrdiff_t operator-(T, T); 3781 for (BuiltinCandidateTypeSet::iterator Ptr 3782 = CandidateTypes.pointer_begin(); 3783 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3784 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 3785 3786 // operator+(T*, ptrdiff_t) or operator-(T*, ptrdiff_t) 3787 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3788 3789 if (Op == OO_Plus) { 3790 // T* operator+(ptrdiff_t, T*); 3791 ParamTypes[0] = ParamTypes[1]; 3792 ParamTypes[1] = *Ptr; 3793 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3794 } else { 3795 // ptrdiff_t operator-(T, T); 3796 ParamTypes[1] = *Ptr; 3797 AddBuiltinCandidate(Context.getPointerDiffType(), ParamTypes, 3798 Args, 2, CandidateSet); 3799 } 3800 } 3801 } 3802 // Fall through 3803 3804 case OO_Slash: 3805 BinaryStar: 3806 Conditional: 3807 // C++ [over.built]p12: 3808 // 3809 // For every pair of promoted arithmetic types L and R, there 3810 // exist candidate operator functions of the form 3811 // 3812 // LR operator*(L, R); 3813 // LR operator/(L, R); 3814 // LR operator+(L, R); 3815 // LR operator-(L, R); 3816 // bool operator<(L, R); 3817 // bool operator>(L, R); 3818 // bool operator<=(L, R); 3819 // bool operator>=(L, R); 3820 // bool operator==(L, R); 3821 // bool operator!=(L, R); 3822 // 3823 // where LR is the result of the usual arithmetic conversions 3824 // between types L and R. 3825 // 3826 // C++ [over.built]p24: 3827 // 3828 // For every pair of promoted arithmetic types L and R, there exist 3829 // candidate operator functions of the form 3830 // 3831 // LR operator?(bool, L, R); 3832 // 3833 // where LR is the result of the usual arithmetic conversions 3834 // between types L and R. 3835 // Our candidates ignore the first parameter. 3836 for (unsigned Left = FirstPromotedArithmeticType; 3837 Left < LastPromotedArithmeticType; ++Left) { 3838 for (unsigned Right = FirstPromotedArithmeticType; 3839 Right < LastPromotedArithmeticType; ++Right) { 3840 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 3841 QualType Result 3842 = isComparison 3843 ? Context.BoolTy 3844 : Context.UsualArithmeticConversionsType(LandR[0], LandR[1]); 3845 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 3846 } 3847 } 3848 break; 3849 3850 case OO_Percent: 3851 BinaryAmp: 3852 case OO_Caret: 3853 case OO_Pipe: 3854 case OO_LessLess: 3855 case OO_GreaterGreater: 3856 // C++ [over.built]p17: 3857 // 3858 // For every pair of promoted integral types L and R, there 3859 // exist candidate operator functions of the form 3860 // 3861 // LR operator%(L, R); 3862 // LR operator&(L, R); 3863 // LR operator^(L, R); 3864 // LR operator|(L, R); 3865 // L operator<<(L, R); 3866 // L operator>>(L, R); 3867 // 3868 // where LR is the result of the usual arithmetic conversions 3869 // between types L and R. 3870 for (unsigned Left = FirstPromotedIntegralType; 3871 Left < LastPromotedIntegralType; ++Left) { 3872 for (unsigned Right = FirstPromotedIntegralType; 3873 Right < LastPromotedIntegralType; ++Right) { 3874 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 3875 QualType Result = (Op == OO_LessLess || Op == OO_GreaterGreater) 3876 ? LandR[0] 3877 : Context.UsualArithmeticConversionsType(LandR[0], LandR[1]); 3878 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 3879 } 3880 } 3881 break; 3882 3883 case OO_Equal: 3884 // C++ [over.built]p20: 3885 // 3886 // For every pair (T, VQ), where T is an enumeration or 3887 // pointer to member type and VQ is either volatile or 3888 // empty, there exist candidate operator functions of the form 3889 // 3890 // VQ T& operator=(VQ T&, T); 3891 for (BuiltinCandidateTypeSet::iterator 3892 Enum = CandidateTypes.enumeration_begin(), 3893 EnumEnd = CandidateTypes.enumeration_end(); 3894 Enum != EnumEnd; ++Enum) 3895 AddBuiltinAssignmentOperatorCandidates(*this, *Enum, Args, 2, 3896 CandidateSet); 3897 for (BuiltinCandidateTypeSet::iterator 3898 MemPtr = CandidateTypes.member_pointer_begin(), 3899 MemPtrEnd = CandidateTypes.member_pointer_end(); 3900 MemPtr != MemPtrEnd; ++MemPtr) 3901 AddBuiltinAssignmentOperatorCandidates(*this, *MemPtr, Args, 2, 3902 CandidateSet); 3903 // Fall through. 3904 3905 case OO_PlusEqual: 3906 case OO_MinusEqual: 3907 // C++ [over.built]p19: 3908 // 3909 // For every pair (T, VQ), where T is any type and VQ is either 3910 // volatile or empty, there exist candidate operator functions 3911 // of the form 3912 // 3913 // T*VQ& operator=(T*VQ&, T*); 3914 // 3915 // C++ [over.built]p21: 3916 // 3917 // For every pair (T, VQ), where T is a cv-qualified or 3918 // cv-unqualified object type and VQ is either volatile or 3919 // empty, there exist candidate operator functions of the form 3920 // 3921 // T*VQ& operator+=(T*VQ&, ptrdiff_t); 3922 // T*VQ& operator-=(T*VQ&, ptrdiff_t); 3923 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3924 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3925 QualType ParamTypes[2]; 3926 ParamTypes[1] = (Op == OO_Equal)? *Ptr : Context.getPointerDiffType(); 3927 3928 // non-volatile version 3929 ParamTypes[0] = Context.getLValueReferenceType(*Ptr); 3930 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3931 /*IsAssigmentOperator=*/Op == OO_Equal); 3932 3933 if (!Context.getCanonicalType(*Ptr).isVolatileQualified() && 3934 VisibleTypeConversionsQuals.hasVolatile()) { 3935 // volatile version 3936 ParamTypes[0] 3937 = Context.getLValueReferenceType(Context.getVolatileType(*Ptr)); 3938 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3939 /*IsAssigmentOperator=*/Op == OO_Equal); 3940 } 3941 } 3942 // Fall through. 3943 3944 case OO_StarEqual: 3945 case OO_SlashEqual: 3946 // C++ [over.built]p18: 3947 // 3948 // For every triple (L, VQ, R), where L is an arithmetic type, 3949 // VQ is either volatile or empty, and R is a promoted 3950 // arithmetic type, there exist candidate operator functions of 3951 // the form 3952 // 3953 // VQ L& operator=(VQ L&, R); 3954 // VQ L& operator*=(VQ L&, R); 3955 // VQ L& operator/=(VQ L&, R); 3956 // VQ L& operator+=(VQ L&, R); 3957 // VQ L& operator-=(VQ L&, R); 3958 for (unsigned Left = 0; Left < NumArithmeticTypes; ++Left) { 3959 for (unsigned Right = FirstPromotedArithmeticType; 3960 Right < LastPromotedArithmeticType; ++Right) { 3961 QualType ParamTypes[2]; 3962 ParamTypes[1] = ArithmeticTypes[Right]; 3963 3964 // Add this built-in operator as a candidate (VQ is empty). 3965 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 3966 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3967 /*IsAssigmentOperator=*/Op == OO_Equal); 3968 3969 // Add this built-in operator as a candidate (VQ is 'volatile'). 3970 if (VisibleTypeConversionsQuals.hasVolatile()) { 3971 ParamTypes[0] = Context.getVolatileType(ArithmeticTypes[Left]); 3972 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 3973 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3974 /*IsAssigmentOperator=*/Op == OO_Equal); 3975 } 3976 } 3977 } 3978 break; 3979 3980 case OO_PercentEqual: 3981 case OO_LessLessEqual: 3982 case OO_GreaterGreaterEqual: 3983 case OO_AmpEqual: 3984 case OO_CaretEqual: 3985 case OO_PipeEqual: 3986 // C++ [over.built]p22: 3987 // 3988 // For every triple (L, VQ, R), where L is an integral type, VQ 3989 // is either volatile or empty, and R is a promoted integral 3990 // type, there exist candidate operator functions of the form 3991 // 3992 // VQ L& operator%=(VQ L&, R); 3993 // VQ L& operator<<=(VQ L&, R); 3994 // VQ L& operator>>=(VQ L&, R); 3995 // VQ L& operator&=(VQ L&, R); 3996 // VQ L& operator^=(VQ L&, R); 3997 // VQ L& operator|=(VQ L&, R); 3998 for (unsigned Left = FirstIntegralType; Left < LastIntegralType; ++Left) { 3999 for (unsigned Right = FirstPromotedIntegralType; 4000 Right < LastPromotedIntegralType; ++Right) { 4001 QualType ParamTypes[2]; 4002 ParamTypes[1] = ArithmeticTypes[Right]; 4003 4004 // Add this built-in operator as a candidate (VQ is empty). 4005 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 4006 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 4007 if (VisibleTypeConversionsQuals.hasVolatile()) { 4008 // Add this built-in operator as a candidate (VQ is 'volatile'). 4009 ParamTypes[0] = ArithmeticTypes[Left]; 4010 ParamTypes[0] = Context.getVolatileType(ParamTypes[0]); 4011 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 4012 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 4013 } 4014 } 4015 } 4016 break; 4017 4018 case OO_Exclaim: { 4019 // C++ [over.operator]p23: 4020 // 4021 // There also exist candidate operator functions of the form 4022 // 4023 // bool operator!(bool); 4024 // bool operator&&(bool, bool); [BELOW] 4025 // bool operator||(bool, bool); [BELOW] 4026 QualType ParamTy = Context.BoolTy; 4027 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet, 4028 /*IsAssignmentOperator=*/false, 4029 /*NumContextualBoolArguments=*/1); 4030 break; 4031 } 4032 4033 case OO_AmpAmp: 4034 case OO_PipePipe: { 4035 // C++ [over.operator]p23: 4036 // 4037 // There also exist candidate operator functions of the form 4038 // 4039 // bool operator!(bool); [ABOVE] 4040 // bool operator&&(bool, bool); 4041 // bool operator||(bool, bool); 4042 QualType ParamTypes[2] = { Context.BoolTy, Context.BoolTy }; 4043 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet, 4044 /*IsAssignmentOperator=*/false, 4045 /*NumContextualBoolArguments=*/2); 4046 break; 4047 } 4048 4049 case OO_Subscript: 4050 // C++ [over.built]p13: 4051 // 4052 // For every cv-qualified or cv-unqualified object type T there 4053 // exist candidate operator functions of the form 4054 // 4055 // T* operator+(T*, ptrdiff_t); [ABOVE] 4056 // T& operator[](T*, ptrdiff_t); 4057 // T* operator-(T*, ptrdiff_t); [ABOVE] 4058 // T* operator+(ptrdiff_t, T*); [ABOVE] 4059 // T& operator[](ptrdiff_t, T*); 4060 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 4061 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4062 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 4063 QualType PointeeType = (*Ptr)->getAs<PointerType>()->getPointeeType(); 4064 QualType ResultTy = Context.getLValueReferenceType(PointeeType); 4065 4066 // T& operator[](T*, ptrdiff_t) 4067 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 4068 4069 // T& operator[](ptrdiff_t, T*); 4070 ParamTypes[0] = ParamTypes[1]; 4071 ParamTypes[1] = *Ptr; 4072 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 4073 } 4074 break; 4075 4076 case OO_ArrowStar: 4077 // C++ [over.built]p11: 4078 // For every quintuple (C1, C2, T, CV1, CV2), where C2 is a class type, 4079 // C1 is the same type as C2 or is a derived class of C2, T is an object 4080 // type or a function type, and CV1 and CV2 are cv-qualifier-seqs, 4081 // there exist candidate operator functions of the form 4082 // CV12 T& operator->*(CV1 C1*, CV2 T C2::*); 4083 // where CV12 is the union of CV1 and CV2. 4084 { 4085 for (BuiltinCandidateTypeSet::iterator Ptr = 4086 CandidateTypes.pointer_begin(); 4087 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4088 QualType C1Ty = (*Ptr); 4089 QualType C1; 4090 QualifierCollector Q1; 4091 if (const PointerType *PointerTy = C1Ty->getAs<PointerType>()) { 4092 C1 = QualType(Q1.strip(PointerTy->getPointeeType()), 0); 4093 if (!isa<RecordType>(C1)) 4094 continue; 4095 // heuristic to reduce number of builtin candidates in the set. 4096 // Add volatile/restrict version only if there are conversions to a 4097 // volatile/restrict type. 4098 if (!VisibleTypeConversionsQuals.hasVolatile() && Q1.hasVolatile()) 4099 continue; 4100 if (!VisibleTypeConversionsQuals.hasRestrict() && Q1.hasRestrict()) 4101 continue; 4102 } 4103 for (BuiltinCandidateTypeSet::iterator 4104 MemPtr = CandidateTypes.member_pointer_begin(), 4105 MemPtrEnd = CandidateTypes.member_pointer_end(); 4106 MemPtr != MemPtrEnd; ++MemPtr) { 4107 const MemberPointerType *mptr = cast<MemberPointerType>(*MemPtr); 4108 QualType C2 = QualType(mptr->getClass(), 0); 4109 C2 = C2.getUnqualifiedType(); 4110 if (C1 != C2 && !IsDerivedFrom(C1, C2)) 4111 break; 4112 QualType ParamTypes[2] = { *Ptr, *MemPtr }; 4113 // build CV12 T& 4114 QualType T = mptr->getPointeeType(); 4115 if (!VisibleTypeConversionsQuals.hasVolatile() && 4116 T.isVolatileQualified()) 4117 continue; 4118 if (!VisibleTypeConversionsQuals.hasRestrict() && 4119 T.isRestrictQualified()) 4120 continue; 4121 T = Q1.apply(T); 4122 QualType ResultTy = Context.getLValueReferenceType(T); 4123 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 4124 } 4125 } 4126 } 4127 break; 4128 4129 case OO_Conditional: 4130 // Note that we don't consider the first argument, since it has been 4131 // contextually converted to bool long ago. The candidates below are 4132 // therefore added as binary. 4133 // 4134 // C++ [over.built]p24: 4135 // For every type T, where T is a pointer or pointer-to-member type, 4136 // there exist candidate operator functions of the form 4137 // 4138 // T operator?(bool, T, T); 4139 // 4140 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(), 4141 E = CandidateTypes.pointer_end(); Ptr != E; ++Ptr) { 4142 QualType ParamTypes[2] = { *Ptr, *Ptr }; 4143 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 4144 } 4145 for (BuiltinCandidateTypeSet::iterator Ptr = 4146 CandidateTypes.member_pointer_begin(), 4147 E = CandidateTypes.member_pointer_end(); Ptr != E; ++Ptr) { 4148 QualType ParamTypes[2] = { *Ptr, *Ptr }; 4149 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 4150 } 4151 goto Conditional; 4152 } 4153} 4154 4155/// \brief Add function candidates found via argument-dependent lookup 4156/// to the set of overloading candidates. 4157/// 4158/// This routine performs argument-dependent name lookup based on the 4159/// given function name (which may also be an operator name) and adds 4160/// all of the overload candidates found by ADL to the overload 4161/// candidate set (C++ [basic.lookup.argdep]). 4162void 4163Sema::AddArgumentDependentLookupCandidates(DeclarationName Name, 4164 bool Operator, 4165 Expr **Args, unsigned NumArgs, 4166 const TemplateArgumentListInfo *ExplicitTemplateArgs, 4167 OverloadCandidateSet& CandidateSet, 4168 bool PartialOverloading) { 4169 ADLResult Fns; 4170 4171 // FIXME: This approach for uniquing ADL results (and removing 4172 // redundant candidates from the set) relies on pointer-equality, 4173 // which means we need to key off the canonical decl. However, 4174 // always going back to the canonical decl might not get us the 4175 // right set of default arguments. What default arguments are 4176 // we supposed to consider on ADL candidates, anyway? 4177 4178 // FIXME: Pass in the explicit template arguments? 4179 ArgumentDependentLookup(Name, Operator, Args, NumArgs, Fns); 4180 4181 // Erase all of the candidates we already knew about. 4182 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 4183 CandEnd = CandidateSet.end(); 4184 Cand != CandEnd; ++Cand) 4185 if (Cand->Function) { 4186 Fns.erase(Cand->Function); 4187 if (FunctionTemplateDecl *FunTmpl = Cand->Function->getPrimaryTemplate()) 4188 Fns.erase(FunTmpl); 4189 } 4190 4191 // For each of the ADL candidates we found, add it to the overload 4192 // set. 4193 for (ADLResult::iterator I = Fns.begin(), E = Fns.end(); I != E; ++I) { 4194 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*I)) { 4195 if (ExplicitTemplateArgs) 4196 continue; 4197 4198 AddOverloadCandidate(FD, AS_none, Args, NumArgs, CandidateSet, 4199 false, false, PartialOverloading); 4200 } else 4201 AddTemplateOverloadCandidate(cast<FunctionTemplateDecl>(*I), 4202 AS_none, ExplicitTemplateArgs, 4203 Args, NumArgs, CandidateSet); 4204 } 4205} 4206 4207/// isBetterOverloadCandidate - Determines whether the first overload 4208/// candidate is a better candidate than the second (C++ 13.3.3p1). 4209bool 4210Sema::isBetterOverloadCandidate(const OverloadCandidate& Cand1, 4211 const OverloadCandidate& Cand2, 4212 SourceLocation Loc) { 4213 // Define viable functions to be better candidates than non-viable 4214 // functions. 4215 if (!Cand2.Viable) 4216 return Cand1.Viable; 4217 else if (!Cand1.Viable) 4218 return false; 4219 4220 // C++ [over.match.best]p1: 4221 // 4222 // -- if F is a static member function, ICS1(F) is defined such 4223 // that ICS1(F) is neither better nor worse than ICS1(G) for 4224 // any function G, and, symmetrically, ICS1(G) is neither 4225 // better nor worse than ICS1(F). 4226 unsigned StartArg = 0; 4227 if (Cand1.IgnoreObjectArgument || Cand2.IgnoreObjectArgument) 4228 StartArg = 1; 4229 4230 // C++ [over.match.best]p1: 4231 // A viable function F1 is defined to be a better function than another 4232 // viable function F2 if for all arguments i, ICSi(F1) is not a worse 4233 // conversion sequence than ICSi(F2), and then... 4234 unsigned NumArgs = Cand1.Conversions.size(); 4235 assert(Cand2.Conversions.size() == NumArgs && "Overload candidate mismatch"); 4236 bool HasBetterConversion = false; 4237 for (unsigned ArgIdx = StartArg; ArgIdx < NumArgs; ++ArgIdx) { 4238 switch (CompareImplicitConversionSequences(Cand1.Conversions[ArgIdx], 4239 Cand2.Conversions[ArgIdx])) { 4240 case ImplicitConversionSequence::Better: 4241 // Cand1 has a better conversion sequence. 4242 HasBetterConversion = true; 4243 break; 4244 4245 case ImplicitConversionSequence::Worse: 4246 // Cand1 can't be better than Cand2. 4247 return false; 4248 4249 case ImplicitConversionSequence::Indistinguishable: 4250 // Do nothing. 4251 break; 4252 } 4253 } 4254 4255 // -- for some argument j, ICSj(F1) is a better conversion sequence than 4256 // ICSj(F2), or, if not that, 4257 if (HasBetterConversion) 4258 return true; 4259 4260 // - F1 is a non-template function and F2 is a function template 4261 // specialization, or, if not that, 4262 if (Cand1.Function && !Cand1.Function->getPrimaryTemplate() && 4263 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 4264 return true; 4265 4266 // -- F1 and F2 are function template specializations, and the function 4267 // template for F1 is more specialized than the template for F2 4268 // according to the partial ordering rules described in 14.5.5.2, or, 4269 // if not that, 4270 if (Cand1.Function && Cand1.Function->getPrimaryTemplate() && 4271 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 4272 if (FunctionTemplateDecl *BetterTemplate 4273 = getMoreSpecializedTemplate(Cand1.Function->getPrimaryTemplate(), 4274 Cand2.Function->getPrimaryTemplate(), 4275 Loc, 4276 isa<CXXConversionDecl>(Cand1.Function)? TPOC_Conversion 4277 : TPOC_Call)) 4278 return BetterTemplate == Cand1.Function->getPrimaryTemplate(); 4279 4280 // -- the context is an initialization by user-defined conversion 4281 // (see 8.5, 13.3.1.5) and the standard conversion sequence 4282 // from the return type of F1 to the destination type (i.e., 4283 // the type of the entity being initialized) is a better 4284 // conversion sequence than the standard conversion sequence 4285 // from the return type of F2 to the destination type. 4286 if (Cand1.Function && Cand2.Function && 4287 isa<CXXConversionDecl>(Cand1.Function) && 4288 isa<CXXConversionDecl>(Cand2.Function)) { 4289 switch (CompareStandardConversionSequences(Cand1.FinalConversion, 4290 Cand2.FinalConversion)) { 4291 case ImplicitConversionSequence::Better: 4292 // Cand1 has a better conversion sequence. 4293 return true; 4294 4295 case ImplicitConversionSequence::Worse: 4296 // Cand1 can't be better than Cand2. 4297 return false; 4298 4299 case ImplicitConversionSequence::Indistinguishable: 4300 // Do nothing 4301 break; 4302 } 4303 } 4304 4305 return false; 4306} 4307 4308/// \brief Computes the best viable function (C++ 13.3.3) 4309/// within an overload candidate set. 4310/// 4311/// \param CandidateSet the set of candidate functions. 4312/// 4313/// \param Loc the location of the function name (or operator symbol) for 4314/// which overload resolution occurs. 4315/// 4316/// \param Best f overload resolution was successful or found a deleted 4317/// function, Best points to the candidate function found. 4318/// 4319/// \returns The result of overload resolution. 4320OverloadingResult Sema::BestViableFunction(OverloadCandidateSet& CandidateSet, 4321 SourceLocation Loc, 4322 OverloadCandidateSet::iterator& Best) { 4323 // Find the best viable function. 4324 Best = CandidateSet.end(); 4325 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 4326 Cand != CandidateSet.end(); ++Cand) { 4327 if (Cand->Viable) { 4328 if (Best == CandidateSet.end() || 4329 isBetterOverloadCandidate(*Cand, *Best, Loc)) 4330 Best = Cand; 4331 } 4332 } 4333 4334 // If we didn't find any viable functions, abort. 4335 if (Best == CandidateSet.end()) 4336 return OR_No_Viable_Function; 4337 4338 // Make sure that this function is better than every other viable 4339 // function. If not, we have an ambiguity. 4340 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 4341 Cand != CandidateSet.end(); ++Cand) { 4342 if (Cand->Viable && 4343 Cand != Best && 4344 !isBetterOverloadCandidate(*Best, *Cand, Loc)) { 4345 Best = CandidateSet.end(); 4346 return OR_Ambiguous; 4347 } 4348 } 4349 4350 // Best is the best viable function. 4351 if (Best->Function && 4352 (Best->Function->isDeleted() || 4353 Best->Function->getAttr<UnavailableAttr>())) 4354 return OR_Deleted; 4355 4356 // C++ [basic.def.odr]p2: 4357 // An overloaded function is used if it is selected by overload resolution 4358 // when referred to from a potentially-evaluated expression. [Note: this 4359 // covers calls to named functions (5.2.2), operator overloading 4360 // (clause 13), user-defined conversions (12.3.2), allocation function for 4361 // placement new (5.3.4), as well as non-default initialization (8.5). 4362 if (Best->Function) 4363 MarkDeclarationReferenced(Loc, Best->Function); 4364 return OR_Success; 4365} 4366 4367namespace { 4368 4369enum OverloadCandidateKind { 4370 oc_function, 4371 oc_method, 4372 oc_constructor, 4373 oc_function_template, 4374 oc_method_template, 4375 oc_constructor_template, 4376 oc_implicit_default_constructor, 4377 oc_implicit_copy_constructor, 4378 oc_implicit_copy_assignment 4379}; 4380 4381OverloadCandidateKind ClassifyOverloadCandidate(Sema &S, 4382 FunctionDecl *Fn, 4383 std::string &Description) { 4384 bool isTemplate = false; 4385 4386 if (FunctionTemplateDecl *FunTmpl = Fn->getPrimaryTemplate()) { 4387 isTemplate = true; 4388 Description = S.getTemplateArgumentBindingsText( 4389 FunTmpl->getTemplateParameters(), *Fn->getTemplateSpecializationArgs()); 4390 } 4391 4392 if (CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(Fn)) { 4393 if (!Ctor->isImplicit()) 4394 return isTemplate ? oc_constructor_template : oc_constructor; 4395 4396 return Ctor->isCopyConstructor() ? oc_implicit_copy_constructor 4397 : oc_implicit_default_constructor; 4398 } 4399 4400 if (CXXMethodDecl *Meth = dyn_cast<CXXMethodDecl>(Fn)) { 4401 // This actually gets spelled 'candidate function' for now, but 4402 // it doesn't hurt to split it out. 4403 if (!Meth->isImplicit()) 4404 return isTemplate ? oc_method_template : oc_method; 4405 4406 assert(Meth->isCopyAssignment() 4407 && "implicit method is not copy assignment operator?"); 4408 return oc_implicit_copy_assignment; 4409 } 4410 4411 return isTemplate ? oc_function_template : oc_function; 4412} 4413 4414} // end anonymous namespace 4415 4416// Notes the location of an overload candidate. 4417void Sema::NoteOverloadCandidate(FunctionDecl *Fn) { 4418 std::string FnDesc; 4419 OverloadCandidateKind K = ClassifyOverloadCandidate(*this, Fn, FnDesc); 4420 Diag(Fn->getLocation(), diag::note_ovl_candidate) 4421 << (unsigned) K << FnDesc; 4422} 4423 4424/// Diagnoses an ambiguous conversion. The partial diagnostic is the 4425/// "lead" diagnostic; it will be given two arguments, the source and 4426/// target types of the conversion. 4427void Sema::DiagnoseAmbiguousConversion(const ImplicitConversionSequence &ICS, 4428 SourceLocation CaretLoc, 4429 const PartialDiagnostic &PDiag) { 4430 Diag(CaretLoc, PDiag) 4431 << ICS.Ambiguous.getFromType() << ICS.Ambiguous.getToType(); 4432 for (AmbiguousConversionSequence::const_iterator 4433 I = ICS.Ambiguous.begin(), E = ICS.Ambiguous.end(); I != E; ++I) { 4434 NoteOverloadCandidate(*I); 4435 } 4436} 4437 4438namespace { 4439 4440void DiagnoseBadConversion(Sema &S, OverloadCandidate *Cand, unsigned I) { 4441 const ImplicitConversionSequence &Conv = Cand->Conversions[I]; 4442 assert(Conv.isBad()); 4443 assert(Cand->Function && "for now, candidate must be a function"); 4444 FunctionDecl *Fn = Cand->Function; 4445 4446 // There's a conversion slot for the object argument if this is a 4447 // non-constructor method. Note that 'I' corresponds the 4448 // conversion-slot index. 4449 bool isObjectArgument = false; 4450 if (isa<CXXMethodDecl>(Fn) && !isa<CXXConstructorDecl>(Fn)) { 4451 if (I == 0) 4452 isObjectArgument = true; 4453 else 4454 I--; 4455 } 4456 4457 std::string FnDesc; 4458 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, FnDesc); 4459 4460 Expr *FromExpr = Conv.Bad.FromExpr; 4461 QualType FromTy = Conv.Bad.getFromType(); 4462 QualType ToTy = Conv.Bad.getToType(); 4463 4464 if (FromTy == S.Context.OverloadTy) { 4465 assert(FromExpr); 4466 Expr *E = FromExpr->IgnoreParens(); 4467 if (isa<UnaryOperator>(E)) 4468 E = cast<UnaryOperator>(E)->getSubExpr()->IgnoreParens(); 4469 DeclarationName Name = cast<OverloadExpr>(E)->getName(); 4470 4471 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_overload) 4472 << (unsigned) FnKind << FnDesc 4473 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 4474 << ToTy << Name << I+1; 4475 return; 4476 } 4477 4478 // Do some hand-waving analysis to see if the non-viability is due 4479 // to a qualifier mismatch. 4480 CanQualType CFromTy = S.Context.getCanonicalType(FromTy); 4481 CanQualType CToTy = S.Context.getCanonicalType(ToTy); 4482 if (CanQual<ReferenceType> RT = CToTy->getAs<ReferenceType>()) 4483 CToTy = RT->getPointeeType(); 4484 else { 4485 // TODO: detect and diagnose the full richness of const mismatches. 4486 if (CanQual<PointerType> FromPT = CFromTy->getAs<PointerType>()) 4487 if (CanQual<PointerType> ToPT = CToTy->getAs<PointerType>()) 4488 CFromTy = FromPT->getPointeeType(), CToTy = ToPT->getPointeeType(); 4489 } 4490 4491 if (CToTy.getUnqualifiedType() == CFromTy.getUnqualifiedType() && 4492 !CToTy.isAtLeastAsQualifiedAs(CFromTy)) { 4493 // It is dumb that we have to do this here. 4494 while (isa<ArrayType>(CFromTy)) 4495 CFromTy = CFromTy->getAs<ArrayType>()->getElementType(); 4496 while (isa<ArrayType>(CToTy)) 4497 CToTy = CFromTy->getAs<ArrayType>()->getElementType(); 4498 4499 Qualifiers FromQs = CFromTy.getQualifiers(); 4500 Qualifiers ToQs = CToTy.getQualifiers(); 4501 4502 if (FromQs.getAddressSpace() != ToQs.getAddressSpace()) { 4503 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_addrspace) 4504 << (unsigned) FnKind << FnDesc 4505 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 4506 << FromTy 4507 << FromQs.getAddressSpace() << ToQs.getAddressSpace() 4508 << (unsigned) isObjectArgument << I+1; 4509 return; 4510 } 4511 4512 unsigned CVR = FromQs.getCVRQualifiers() & ~ToQs.getCVRQualifiers(); 4513 assert(CVR && "unexpected qualifiers mismatch"); 4514 4515 if (isObjectArgument) { 4516 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr_this) 4517 << (unsigned) FnKind << FnDesc 4518 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 4519 << FromTy << (CVR - 1); 4520 } else { 4521 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr) 4522 << (unsigned) FnKind << FnDesc 4523 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 4524 << FromTy << (CVR - 1) << I+1; 4525 } 4526 return; 4527 } 4528 4529 // Diagnose references or pointers to incomplete types differently, 4530 // since it's far from impossible that the incompleteness triggered 4531 // the failure. 4532 QualType TempFromTy = FromTy.getNonReferenceType(); 4533 if (const PointerType *PTy = TempFromTy->getAs<PointerType>()) 4534 TempFromTy = PTy->getPointeeType(); 4535 if (TempFromTy->isIncompleteType()) { 4536 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_conv_incomplete) 4537 << (unsigned) FnKind << FnDesc 4538 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 4539 << FromTy << ToTy << (unsigned) isObjectArgument << I+1; 4540 return; 4541 } 4542 4543 // TODO: specialize more based on the kind of mismatch 4544 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_conv) 4545 << (unsigned) FnKind << FnDesc 4546 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 4547 << FromTy << ToTy << (unsigned) isObjectArgument << I+1; 4548} 4549 4550void DiagnoseArityMismatch(Sema &S, OverloadCandidate *Cand, 4551 unsigned NumFormalArgs) { 4552 // TODO: treat calls to a missing default constructor as a special case 4553 4554 FunctionDecl *Fn = Cand->Function; 4555 const FunctionProtoType *FnTy = Fn->getType()->getAs<FunctionProtoType>(); 4556 4557 unsigned MinParams = Fn->getMinRequiredArguments(); 4558 4559 // at least / at most / exactly 4560 unsigned mode, modeCount; 4561 if (NumFormalArgs < MinParams) { 4562 assert(Cand->FailureKind == ovl_fail_too_few_arguments); 4563 if (MinParams != FnTy->getNumArgs() || FnTy->isVariadic()) 4564 mode = 0; // "at least" 4565 else 4566 mode = 2; // "exactly" 4567 modeCount = MinParams; 4568 } else { 4569 assert(Cand->FailureKind == ovl_fail_too_many_arguments); 4570 if (MinParams != FnTy->getNumArgs()) 4571 mode = 1; // "at most" 4572 else 4573 mode = 2; // "exactly" 4574 modeCount = FnTy->getNumArgs(); 4575 } 4576 4577 std::string Description; 4578 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, Description); 4579 4580 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_arity) 4581 << (unsigned) FnKind << Description << mode << modeCount << NumFormalArgs; 4582} 4583 4584/// Diagnose a failed template-argument deduction. 4585void DiagnoseBadDeduction(Sema &S, OverloadCandidate *Cand, 4586 Expr **Args, unsigned NumArgs) { 4587 FunctionDecl *Fn = Cand->Function; // pattern 4588 4589 TemplateParameter Param = TemplateParameter::getFromOpaqueValue( 4590 Cand->DeductionFailure.TemplateParameter); 4591 4592 switch (Cand->DeductionFailure.Result) { 4593 case Sema::TDK_Success: 4594 llvm_unreachable("TDK_success while diagnosing bad deduction"); 4595 4596 case Sema::TDK_Incomplete: { 4597 NamedDecl *ParamD; 4598 (ParamD = Param.dyn_cast<TemplateTypeParmDecl*>()) || 4599 (ParamD = Param.dyn_cast<NonTypeTemplateParmDecl*>()) || 4600 (ParamD = Param.dyn_cast<TemplateTemplateParmDecl*>()); 4601 assert(ParamD && "no parameter found for incomplete deduction result"); 4602 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_incomplete_deduction) 4603 << ParamD->getDeclName(); 4604 return; 4605 } 4606 4607 // TODO: diagnose these individually, then kill off 4608 // note_ovl_candidate_bad_deduction, which is uselessly vague. 4609 case Sema::TDK_InstantiationDepth: 4610 case Sema::TDK_Inconsistent: 4611 case Sema::TDK_InconsistentQuals: 4612 case Sema::TDK_SubstitutionFailure: 4613 case Sema::TDK_NonDeducedMismatch: 4614 case Sema::TDK_TooManyArguments: 4615 case Sema::TDK_TooFewArguments: 4616 case Sema::TDK_InvalidExplicitArguments: 4617 case Sema::TDK_FailedOverloadResolution: 4618 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_deduction); 4619 return; 4620 } 4621} 4622 4623/// Generates a 'note' diagnostic for an overload candidate. We've 4624/// already generated a primary error at the call site. 4625/// 4626/// It really does need to be a single diagnostic with its caret 4627/// pointed at the candidate declaration. Yes, this creates some 4628/// major challenges of technical writing. Yes, this makes pointing 4629/// out problems with specific arguments quite awkward. It's still 4630/// better than generating twenty screens of text for every failed 4631/// overload. 4632/// 4633/// It would be great to be able to express per-candidate problems 4634/// more richly for those diagnostic clients that cared, but we'd 4635/// still have to be just as careful with the default diagnostics. 4636void NoteFunctionCandidate(Sema &S, OverloadCandidate *Cand, 4637 Expr **Args, unsigned NumArgs) { 4638 FunctionDecl *Fn = Cand->Function; 4639 4640 // Note deleted candidates, but only if they're viable. 4641 if (Cand->Viable && (Fn->isDeleted() || Fn->hasAttr<UnavailableAttr>())) { 4642 std::string FnDesc; 4643 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, FnDesc); 4644 4645 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_deleted) 4646 << FnKind << FnDesc << Fn->isDeleted(); 4647 return; 4648 } 4649 4650 // We don't really have anything else to say about viable candidates. 4651 if (Cand->Viable) { 4652 S.NoteOverloadCandidate(Fn); 4653 return; 4654 } 4655 4656 switch (Cand->FailureKind) { 4657 case ovl_fail_too_many_arguments: 4658 case ovl_fail_too_few_arguments: 4659 return DiagnoseArityMismatch(S, Cand, NumArgs); 4660 4661 case ovl_fail_bad_deduction: 4662 return DiagnoseBadDeduction(S, Cand, Args, NumArgs); 4663 4664 case ovl_fail_trivial_conversion: 4665 case ovl_fail_bad_final_conversion: 4666 return S.NoteOverloadCandidate(Fn); 4667 4668 case ovl_fail_bad_conversion: 4669 for (unsigned I = 0, N = Cand->Conversions.size(); I != N; ++I) 4670 if (Cand->Conversions[I].isBad()) 4671 return DiagnoseBadConversion(S, Cand, I); 4672 4673 // FIXME: this currently happens when we're called from SemaInit 4674 // when user-conversion overload fails. Figure out how to handle 4675 // those conditions and diagnose them well. 4676 return S.NoteOverloadCandidate(Fn); 4677 } 4678} 4679 4680void NoteSurrogateCandidate(Sema &S, OverloadCandidate *Cand) { 4681 // Desugar the type of the surrogate down to a function type, 4682 // retaining as many typedefs as possible while still showing 4683 // the function type (and, therefore, its parameter types). 4684 QualType FnType = Cand->Surrogate->getConversionType(); 4685 bool isLValueReference = false; 4686 bool isRValueReference = false; 4687 bool isPointer = false; 4688 if (const LValueReferenceType *FnTypeRef = 4689 FnType->getAs<LValueReferenceType>()) { 4690 FnType = FnTypeRef->getPointeeType(); 4691 isLValueReference = true; 4692 } else if (const RValueReferenceType *FnTypeRef = 4693 FnType->getAs<RValueReferenceType>()) { 4694 FnType = FnTypeRef->getPointeeType(); 4695 isRValueReference = true; 4696 } 4697 if (const PointerType *FnTypePtr = FnType->getAs<PointerType>()) { 4698 FnType = FnTypePtr->getPointeeType(); 4699 isPointer = true; 4700 } 4701 // Desugar down to a function type. 4702 FnType = QualType(FnType->getAs<FunctionType>(), 0); 4703 // Reconstruct the pointer/reference as appropriate. 4704 if (isPointer) FnType = S.Context.getPointerType(FnType); 4705 if (isRValueReference) FnType = S.Context.getRValueReferenceType(FnType); 4706 if (isLValueReference) FnType = S.Context.getLValueReferenceType(FnType); 4707 4708 S.Diag(Cand->Surrogate->getLocation(), diag::note_ovl_surrogate_cand) 4709 << FnType; 4710} 4711 4712void NoteBuiltinOperatorCandidate(Sema &S, 4713 const char *Opc, 4714 SourceLocation OpLoc, 4715 OverloadCandidate *Cand) { 4716 assert(Cand->Conversions.size() <= 2 && "builtin operator is not binary"); 4717 std::string TypeStr("operator"); 4718 TypeStr += Opc; 4719 TypeStr += "("; 4720 TypeStr += Cand->BuiltinTypes.ParamTypes[0].getAsString(); 4721 if (Cand->Conversions.size() == 1) { 4722 TypeStr += ")"; 4723 S.Diag(OpLoc, diag::note_ovl_builtin_unary_candidate) << TypeStr; 4724 } else { 4725 TypeStr += ", "; 4726 TypeStr += Cand->BuiltinTypes.ParamTypes[1].getAsString(); 4727 TypeStr += ")"; 4728 S.Diag(OpLoc, diag::note_ovl_builtin_binary_candidate) << TypeStr; 4729 } 4730} 4731 4732void NoteAmbiguousUserConversions(Sema &S, SourceLocation OpLoc, 4733 OverloadCandidate *Cand) { 4734 unsigned NoOperands = Cand->Conversions.size(); 4735 for (unsigned ArgIdx = 0; ArgIdx < NoOperands; ++ArgIdx) { 4736 const ImplicitConversionSequence &ICS = Cand->Conversions[ArgIdx]; 4737 if (ICS.isBad()) break; // all meaningless after first invalid 4738 if (!ICS.isAmbiguous()) continue; 4739 4740 S.DiagnoseAmbiguousConversion(ICS, OpLoc, 4741 PDiag(diag::note_ambiguous_type_conversion)); 4742 } 4743} 4744 4745SourceLocation GetLocationForCandidate(const OverloadCandidate *Cand) { 4746 if (Cand->Function) 4747 return Cand->Function->getLocation(); 4748 if (Cand->IsSurrogate) 4749 return Cand->Surrogate->getLocation(); 4750 return SourceLocation(); 4751} 4752 4753struct CompareOverloadCandidatesForDisplay { 4754 Sema &S; 4755 CompareOverloadCandidatesForDisplay(Sema &S) : S(S) {} 4756 4757 bool operator()(const OverloadCandidate *L, 4758 const OverloadCandidate *R) { 4759 // Fast-path this check. 4760 if (L == R) return false; 4761 4762 // Order first by viability. 4763 if (L->Viable) { 4764 if (!R->Viable) return true; 4765 4766 // TODO: introduce a tri-valued comparison for overload 4767 // candidates. Would be more worthwhile if we had a sort 4768 // that could exploit it. 4769 if (S.isBetterOverloadCandidate(*L, *R, SourceLocation())) return true; 4770 if (S.isBetterOverloadCandidate(*R, *L, SourceLocation())) return false; 4771 } else if (R->Viable) 4772 return false; 4773 4774 assert(L->Viable == R->Viable); 4775 4776 // Criteria by which we can sort non-viable candidates: 4777 if (!L->Viable) { 4778 // 1. Arity mismatches come after other candidates. 4779 if (L->FailureKind == ovl_fail_too_many_arguments || 4780 L->FailureKind == ovl_fail_too_few_arguments) 4781 return false; 4782 if (R->FailureKind == ovl_fail_too_many_arguments || 4783 R->FailureKind == ovl_fail_too_few_arguments) 4784 return true; 4785 4786 // 2. Bad conversions come first and are ordered by the number 4787 // of bad conversions and quality of good conversions. 4788 if (L->FailureKind == ovl_fail_bad_conversion) { 4789 if (R->FailureKind != ovl_fail_bad_conversion) 4790 return true; 4791 4792 // If there's any ordering between the defined conversions... 4793 // FIXME: this might not be transitive. 4794 assert(L->Conversions.size() == R->Conversions.size()); 4795 4796 int leftBetter = 0; 4797 for (unsigned I = 0, E = L->Conversions.size(); I != E; ++I) { 4798 switch (S.CompareImplicitConversionSequences(L->Conversions[I], 4799 R->Conversions[I])) { 4800 case ImplicitConversionSequence::Better: 4801 leftBetter++; 4802 break; 4803 4804 case ImplicitConversionSequence::Worse: 4805 leftBetter--; 4806 break; 4807 4808 case ImplicitConversionSequence::Indistinguishable: 4809 break; 4810 } 4811 } 4812 if (leftBetter > 0) return true; 4813 if (leftBetter < 0) return false; 4814 4815 } else if (R->FailureKind == ovl_fail_bad_conversion) 4816 return false; 4817 4818 // TODO: others? 4819 } 4820 4821 // Sort everything else by location. 4822 SourceLocation LLoc = GetLocationForCandidate(L); 4823 SourceLocation RLoc = GetLocationForCandidate(R); 4824 4825 // Put candidates without locations (e.g. builtins) at the end. 4826 if (LLoc.isInvalid()) return false; 4827 if (RLoc.isInvalid()) return true; 4828 4829 return S.SourceMgr.isBeforeInTranslationUnit(LLoc, RLoc); 4830 } 4831}; 4832 4833/// CompleteNonViableCandidate - Normally, overload resolution only 4834/// computes up to the first 4835void CompleteNonViableCandidate(Sema &S, OverloadCandidate *Cand, 4836 Expr **Args, unsigned NumArgs) { 4837 assert(!Cand->Viable); 4838 4839 // Don't do anything on failures other than bad conversion. 4840 if (Cand->FailureKind != ovl_fail_bad_conversion) return; 4841 4842 // Skip forward to the first bad conversion. 4843 unsigned ConvIdx = 0; 4844 unsigned ConvCount = Cand->Conversions.size(); 4845 while (true) { 4846 assert(ConvIdx != ConvCount && "no bad conversion in candidate"); 4847 ConvIdx++; 4848 if (Cand->Conversions[ConvIdx - 1].isBad()) 4849 break; 4850 } 4851 4852 if (ConvIdx == ConvCount) 4853 return; 4854 4855 // FIXME: these should probably be preserved from the overload 4856 // operation somehow. 4857 bool SuppressUserConversions = false; 4858 bool ForceRValue = false; 4859 4860 const FunctionProtoType* Proto; 4861 unsigned ArgIdx = ConvIdx; 4862 4863 if (Cand->IsSurrogate) { 4864 QualType ConvType 4865 = Cand->Surrogate->getConversionType().getNonReferenceType(); 4866 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 4867 ConvType = ConvPtrType->getPointeeType(); 4868 Proto = ConvType->getAs<FunctionProtoType>(); 4869 ArgIdx--; 4870 } else if (Cand->Function) { 4871 Proto = Cand->Function->getType()->getAs<FunctionProtoType>(); 4872 if (isa<CXXMethodDecl>(Cand->Function) && 4873 !isa<CXXConstructorDecl>(Cand->Function)) 4874 ArgIdx--; 4875 } else { 4876 // Builtin binary operator with a bad first conversion. 4877 assert(ConvCount <= 3); 4878 for (; ConvIdx != ConvCount; ++ConvIdx) 4879 Cand->Conversions[ConvIdx] 4880 = S.TryCopyInitialization(Args[ConvIdx], 4881 Cand->BuiltinTypes.ParamTypes[ConvIdx], 4882 SuppressUserConversions, ForceRValue, 4883 /*InOverloadResolution*/ true); 4884 return; 4885 } 4886 4887 // Fill in the rest of the conversions. 4888 unsigned NumArgsInProto = Proto->getNumArgs(); 4889 for (; ConvIdx != ConvCount; ++ConvIdx, ++ArgIdx) { 4890 if (ArgIdx < NumArgsInProto) 4891 Cand->Conversions[ConvIdx] 4892 = S.TryCopyInitialization(Args[ArgIdx], Proto->getArgType(ArgIdx), 4893 SuppressUserConversions, ForceRValue, 4894 /*InOverloadResolution=*/true); 4895 else 4896 Cand->Conversions[ConvIdx].setEllipsis(); 4897 } 4898} 4899 4900} // end anonymous namespace 4901 4902/// PrintOverloadCandidates - When overload resolution fails, prints 4903/// diagnostic messages containing the candidates in the candidate 4904/// set. 4905void 4906Sema::PrintOverloadCandidates(OverloadCandidateSet& CandidateSet, 4907 OverloadCandidateDisplayKind OCD, 4908 Expr **Args, unsigned NumArgs, 4909 const char *Opc, 4910 SourceLocation OpLoc) { 4911 // Sort the candidates by viability and position. Sorting directly would 4912 // be prohibitive, so we make a set of pointers and sort those. 4913 llvm::SmallVector<OverloadCandidate*, 32> Cands; 4914 if (OCD == OCD_AllCandidates) Cands.reserve(CandidateSet.size()); 4915 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 4916 LastCand = CandidateSet.end(); 4917 Cand != LastCand; ++Cand) { 4918 if (Cand->Viable) 4919 Cands.push_back(Cand); 4920 else if (OCD == OCD_AllCandidates) { 4921 CompleteNonViableCandidate(*this, Cand, Args, NumArgs); 4922 Cands.push_back(Cand); 4923 } 4924 } 4925 4926 std::sort(Cands.begin(), Cands.end(), 4927 CompareOverloadCandidatesForDisplay(*this)); 4928 4929 bool ReportedAmbiguousConversions = false; 4930 4931 llvm::SmallVectorImpl<OverloadCandidate*>::iterator I, E; 4932 for (I = Cands.begin(), E = Cands.end(); I != E; ++I) { 4933 OverloadCandidate *Cand = *I; 4934 4935 if (Cand->Function) 4936 NoteFunctionCandidate(*this, Cand, Args, NumArgs); 4937 else if (Cand->IsSurrogate) 4938 NoteSurrogateCandidate(*this, Cand); 4939 4940 // This a builtin candidate. We do not, in general, want to list 4941 // every possible builtin candidate. 4942 else if (Cand->Viable) { 4943 // Generally we only see ambiguities including viable builtin 4944 // operators if overload resolution got screwed up by an 4945 // ambiguous user-defined conversion. 4946 // 4947 // FIXME: It's quite possible for different conversions to see 4948 // different ambiguities, though. 4949 if (!ReportedAmbiguousConversions) { 4950 NoteAmbiguousUserConversions(*this, OpLoc, Cand); 4951 ReportedAmbiguousConversions = true; 4952 } 4953 4954 // If this is a viable builtin, print it. 4955 NoteBuiltinOperatorCandidate(*this, Opc, OpLoc, Cand); 4956 } 4957 } 4958} 4959 4960static bool CheckUnresolvedAccess(Sema &S, OverloadExpr *E, NamedDecl *D, 4961 AccessSpecifier AS) { 4962 if (isa<UnresolvedLookupExpr>(E)) 4963 return S.CheckUnresolvedLookupAccess(cast<UnresolvedLookupExpr>(E), D, AS); 4964 4965 return S.CheckUnresolvedMemberAccess(cast<UnresolvedMemberExpr>(E), D, AS); 4966} 4967 4968/// ResolveAddressOfOverloadedFunction - Try to resolve the address of 4969/// an overloaded function (C++ [over.over]), where @p From is an 4970/// expression with overloaded function type and @p ToType is the type 4971/// we're trying to resolve to. For example: 4972/// 4973/// @code 4974/// int f(double); 4975/// int f(int); 4976/// 4977/// int (*pfd)(double) = f; // selects f(double) 4978/// @endcode 4979/// 4980/// This routine returns the resulting FunctionDecl if it could be 4981/// resolved, and NULL otherwise. When @p Complain is true, this 4982/// routine will emit diagnostics if there is an error. 4983FunctionDecl * 4984Sema::ResolveAddressOfOverloadedFunction(Expr *From, QualType ToType, 4985 bool Complain) { 4986 QualType FunctionType = ToType; 4987 bool IsMember = false; 4988 if (const PointerType *ToTypePtr = ToType->getAs<PointerType>()) 4989 FunctionType = ToTypePtr->getPointeeType(); 4990 else if (const ReferenceType *ToTypeRef = ToType->getAs<ReferenceType>()) 4991 FunctionType = ToTypeRef->getPointeeType(); 4992 else if (const MemberPointerType *MemTypePtr = 4993 ToType->getAs<MemberPointerType>()) { 4994 FunctionType = MemTypePtr->getPointeeType(); 4995 IsMember = true; 4996 } 4997 4998 // We only look at pointers or references to functions. 4999 FunctionType = Context.getCanonicalType(FunctionType).getUnqualifiedType(); 5000 if (!FunctionType->isFunctionType()) 5001 return 0; 5002 5003 // Find the actual overloaded function declaration. 5004 if (From->getType() != Context.OverloadTy) 5005 return 0; 5006 5007 // C++ [over.over]p1: 5008 // [...] [Note: any redundant set of parentheses surrounding the 5009 // overloaded function name is ignored (5.1). ] 5010 // C++ [over.over]p1: 5011 // [...] The overloaded function name can be preceded by the & 5012 // operator. 5013 OverloadExpr *OvlExpr = OverloadExpr::find(From).getPointer(); 5014 TemplateArgumentListInfo ETABuffer, *ExplicitTemplateArgs = 0; 5015 if (OvlExpr->hasExplicitTemplateArgs()) { 5016 OvlExpr->getExplicitTemplateArgs().copyInto(ETABuffer); 5017 ExplicitTemplateArgs = &ETABuffer; 5018 } 5019 5020 // Look through all of the overloaded functions, searching for one 5021 // whose type matches exactly. 5022 UnresolvedSet<4> Matches; // contains only FunctionDecls 5023 bool FoundNonTemplateFunction = false; 5024 for (UnresolvedSetIterator I = OvlExpr->decls_begin(), 5025 E = OvlExpr->decls_end(); I != E; ++I) { 5026 // Look through any using declarations to find the underlying function. 5027 NamedDecl *Fn = (*I)->getUnderlyingDecl(); 5028 5029 // C++ [over.over]p3: 5030 // Non-member functions and static member functions match 5031 // targets of type "pointer-to-function" or "reference-to-function." 5032 // Nonstatic member functions match targets of 5033 // type "pointer-to-member-function." 5034 // Note that according to DR 247, the containing class does not matter. 5035 5036 if (FunctionTemplateDecl *FunctionTemplate 5037 = dyn_cast<FunctionTemplateDecl>(Fn)) { 5038 if (CXXMethodDecl *Method 5039 = dyn_cast<CXXMethodDecl>(FunctionTemplate->getTemplatedDecl())) { 5040 // Skip non-static function templates when converting to pointer, and 5041 // static when converting to member pointer. 5042 if (Method->isStatic() == IsMember) 5043 continue; 5044 } else if (IsMember) 5045 continue; 5046 5047 // C++ [over.over]p2: 5048 // If the name is a function template, template argument deduction is 5049 // done (14.8.2.2), and if the argument deduction succeeds, the 5050 // resulting template argument list is used to generate a single 5051 // function template specialization, which is added to the set of 5052 // overloaded functions considered. 5053 // FIXME: We don't really want to build the specialization here, do we? 5054 FunctionDecl *Specialization = 0; 5055 TemplateDeductionInfo Info(Context, OvlExpr->getNameLoc()); 5056 if (TemplateDeductionResult Result 5057 = DeduceTemplateArguments(FunctionTemplate, ExplicitTemplateArgs, 5058 FunctionType, Specialization, Info)) { 5059 // FIXME: make a note of the failed deduction for diagnostics. 5060 (void)Result; 5061 } else { 5062 // FIXME: If the match isn't exact, shouldn't we just drop this as 5063 // a candidate? Find a testcase before changing the code. 5064 assert(FunctionType 5065 == Context.getCanonicalType(Specialization->getType())); 5066 Matches.addDecl(cast<FunctionDecl>(Specialization->getCanonicalDecl()), 5067 I.getAccess()); 5068 } 5069 5070 continue; 5071 } 5072 5073 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 5074 // Skip non-static functions when converting to pointer, and static 5075 // when converting to member pointer. 5076 if (Method->isStatic() == IsMember) 5077 continue; 5078 5079 // If we have explicit template arguments, skip non-templates. 5080 if (OvlExpr->hasExplicitTemplateArgs()) 5081 continue; 5082 } else if (IsMember) 5083 continue; 5084 5085 if (FunctionDecl *FunDecl = dyn_cast<FunctionDecl>(Fn)) { 5086 QualType ResultTy; 5087 if (Context.hasSameUnqualifiedType(FunctionType, FunDecl->getType()) || 5088 IsNoReturnConversion(Context, FunDecl->getType(), FunctionType, 5089 ResultTy)) { 5090 Matches.addDecl(cast<FunctionDecl>(FunDecl->getCanonicalDecl()), 5091 I.getAccess()); 5092 FoundNonTemplateFunction = true; 5093 } 5094 } 5095 } 5096 5097 // If there were 0 or 1 matches, we're done. 5098 if (Matches.empty()) 5099 return 0; 5100 else if (Matches.size() == 1) { 5101 FunctionDecl *Result = cast<FunctionDecl>(*Matches.begin()); 5102 MarkDeclarationReferenced(From->getLocStart(), Result); 5103 if (Complain) 5104 CheckUnresolvedAccess(*this, OvlExpr, Result, Matches.begin().getAccess()); 5105 return Result; 5106 } 5107 5108 // C++ [over.over]p4: 5109 // If more than one function is selected, [...] 5110 if (!FoundNonTemplateFunction) { 5111 // [...] and any given function template specialization F1 is 5112 // eliminated if the set contains a second function template 5113 // specialization whose function template is more specialized 5114 // than the function template of F1 according to the partial 5115 // ordering rules of 14.5.5.2. 5116 5117 // The algorithm specified above is quadratic. We instead use a 5118 // two-pass algorithm (similar to the one used to identify the 5119 // best viable function in an overload set) that identifies the 5120 // best function template (if it exists). 5121 5122 UnresolvedSetIterator Result = 5123 getMostSpecialized(Matches.begin(), Matches.end(), 5124 TPOC_Other, From->getLocStart(), 5125 PDiag(), 5126 PDiag(diag::err_addr_ovl_ambiguous) 5127 << Matches[0]->getDeclName(), 5128 PDiag(diag::note_ovl_candidate) 5129 << (unsigned) oc_function_template); 5130 assert(Result != Matches.end() && "no most-specialized template"); 5131 MarkDeclarationReferenced(From->getLocStart(), *Result); 5132 if (Complain) 5133 CheckUnresolvedAccess(*this, OvlExpr, *Result, Result.getAccess()); 5134 return cast<FunctionDecl>(*Result); 5135 } 5136 5137 // [...] any function template specializations in the set are 5138 // eliminated if the set also contains a non-template function, [...] 5139 for (unsigned I = 0, N = Matches.size(); I != N; ) { 5140 if (cast<FunctionDecl>(Matches[I].getDecl())->getPrimaryTemplate() == 0) 5141 ++I; 5142 else { 5143 Matches.erase(I); 5144 --N; 5145 } 5146 } 5147 5148 // [...] After such eliminations, if any, there shall remain exactly one 5149 // selected function. 5150 if (Matches.size() == 1) { 5151 UnresolvedSetIterator Match = Matches.begin(); 5152 MarkDeclarationReferenced(From->getLocStart(), *Match); 5153 if (Complain) 5154 CheckUnresolvedAccess(*this, OvlExpr, *Match, Match.getAccess()); 5155 return cast<FunctionDecl>(*Match); 5156 } 5157 5158 // FIXME: We should probably return the same thing that BestViableFunction 5159 // returns (even if we issue the diagnostics here). 5160 Diag(From->getLocStart(), diag::err_addr_ovl_ambiguous) 5161 << Matches[0]->getDeclName(); 5162 for (UnresolvedSetIterator I = Matches.begin(), 5163 E = Matches.end(); I != E; ++I) 5164 NoteOverloadCandidate(cast<FunctionDecl>(*I)); 5165 return 0; 5166} 5167 5168/// \brief Given an expression that refers to an overloaded function, try to 5169/// resolve that overloaded function expression down to a single function. 5170/// 5171/// This routine can only resolve template-ids that refer to a single function 5172/// template, where that template-id refers to a single template whose template 5173/// arguments are either provided by the template-id or have defaults, 5174/// as described in C++0x [temp.arg.explicit]p3. 5175FunctionDecl *Sema::ResolveSingleFunctionTemplateSpecialization(Expr *From) { 5176 // C++ [over.over]p1: 5177 // [...] [Note: any redundant set of parentheses surrounding the 5178 // overloaded function name is ignored (5.1). ] 5179 // C++ [over.over]p1: 5180 // [...] The overloaded function name can be preceded by the & 5181 // operator. 5182 5183 if (From->getType() != Context.OverloadTy) 5184 return 0; 5185 5186 OverloadExpr *OvlExpr = OverloadExpr::find(From).getPointer(); 5187 5188 // If we didn't actually find any template-ids, we're done. 5189 if (!OvlExpr->hasExplicitTemplateArgs()) 5190 return 0; 5191 5192 TemplateArgumentListInfo ExplicitTemplateArgs; 5193 OvlExpr->getExplicitTemplateArgs().copyInto(ExplicitTemplateArgs); 5194 5195 // Look through all of the overloaded functions, searching for one 5196 // whose type matches exactly. 5197 FunctionDecl *Matched = 0; 5198 for (UnresolvedSetIterator I = OvlExpr->decls_begin(), 5199 E = OvlExpr->decls_end(); I != E; ++I) { 5200 // C++0x [temp.arg.explicit]p3: 5201 // [...] In contexts where deduction is done and fails, or in contexts 5202 // where deduction is not done, if a template argument list is 5203 // specified and it, along with any default template arguments, 5204 // identifies a single function template specialization, then the 5205 // template-id is an lvalue for the function template specialization. 5206 FunctionTemplateDecl *FunctionTemplate = cast<FunctionTemplateDecl>(*I); 5207 5208 // C++ [over.over]p2: 5209 // If the name is a function template, template argument deduction is 5210 // done (14.8.2.2), and if the argument deduction succeeds, the 5211 // resulting template argument list is used to generate a single 5212 // function template specialization, which is added to the set of 5213 // overloaded functions considered. 5214 FunctionDecl *Specialization = 0; 5215 TemplateDeductionInfo Info(Context, OvlExpr->getNameLoc()); 5216 if (TemplateDeductionResult Result 5217 = DeduceTemplateArguments(FunctionTemplate, &ExplicitTemplateArgs, 5218 Specialization, Info)) { 5219 // FIXME: make a note of the failed deduction for diagnostics. 5220 (void)Result; 5221 continue; 5222 } 5223 5224 // Multiple matches; we can't resolve to a single declaration. 5225 if (Matched) 5226 return 0; 5227 5228 Matched = Specialization; 5229 } 5230 5231 return Matched; 5232} 5233 5234/// \brief Add a single candidate to the overload set. 5235static void AddOverloadedCallCandidate(Sema &S, 5236 NamedDecl *Callee, 5237 AccessSpecifier Access, 5238 const TemplateArgumentListInfo *ExplicitTemplateArgs, 5239 Expr **Args, unsigned NumArgs, 5240 OverloadCandidateSet &CandidateSet, 5241 bool PartialOverloading) { 5242 if (isa<UsingShadowDecl>(Callee)) 5243 Callee = cast<UsingShadowDecl>(Callee)->getTargetDecl(); 5244 5245 if (FunctionDecl *Func = dyn_cast<FunctionDecl>(Callee)) { 5246 assert(!ExplicitTemplateArgs && "Explicit template arguments?"); 5247 S.AddOverloadCandidate(Func, Access, Args, NumArgs, CandidateSet, 5248 false, false, PartialOverloading); 5249 return; 5250 } 5251 5252 if (FunctionTemplateDecl *FuncTemplate 5253 = dyn_cast<FunctionTemplateDecl>(Callee)) { 5254 S.AddTemplateOverloadCandidate(FuncTemplate, Access, ExplicitTemplateArgs, 5255 Args, NumArgs, CandidateSet); 5256 return; 5257 } 5258 5259 assert(false && "unhandled case in overloaded call candidate"); 5260 5261 // do nothing? 5262} 5263 5264/// \brief Add the overload candidates named by callee and/or found by argument 5265/// dependent lookup to the given overload set. 5266void Sema::AddOverloadedCallCandidates(UnresolvedLookupExpr *ULE, 5267 Expr **Args, unsigned NumArgs, 5268 OverloadCandidateSet &CandidateSet, 5269 bool PartialOverloading) { 5270 5271#ifndef NDEBUG 5272 // Verify that ArgumentDependentLookup is consistent with the rules 5273 // in C++0x [basic.lookup.argdep]p3: 5274 // 5275 // Let X be the lookup set produced by unqualified lookup (3.4.1) 5276 // and let Y be the lookup set produced by argument dependent 5277 // lookup (defined as follows). If X contains 5278 // 5279 // -- a declaration of a class member, or 5280 // 5281 // -- a block-scope function declaration that is not a 5282 // using-declaration, or 5283 // 5284 // -- a declaration that is neither a function or a function 5285 // template 5286 // 5287 // then Y is empty. 5288 5289 if (ULE->requiresADL()) { 5290 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(), 5291 E = ULE->decls_end(); I != E; ++I) { 5292 assert(!(*I)->getDeclContext()->isRecord()); 5293 assert(isa<UsingShadowDecl>(*I) || 5294 !(*I)->getDeclContext()->isFunctionOrMethod()); 5295 assert((*I)->getUnderlyingDecl()->isFunctionOrFunctionTemplate()); 5296 } 5297 } 5298#endif 5299 5300 // It would be nice to avoid this copy. 5301 TemplateArgumentListInfo TABuffer; 5302 const TemplateArgumentListInfo *ExplicitTemplateArgs = 0; 5303 if (ULE->hasExplicitTemplateArgs()) { 5304 ULE->copyTemplateArgumentsInto(TABuffer); 5305 ExplicitTemplateArgs = &TABuffer; 5306 } 5307 5308 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(), 5309 E = ULE->decls_end(); I != E; ++I) 5310 AddOverloadedCallCandidate(*this, *I, I.getAccess(), ExplicitTemplateArgs, 5311 Args, NumArgs, CandidateSet, 5312 PartialOverloading); 5313 5314 if (ULE->requiresADL()) 5315 AddArgumentDependentLookupCandidates(ULE->getName(), /*Operator*/ false, 5316 Args, NumArgs, 5317 ExplicitTemplateArgs, 5318 CandidateSet, 5319 PartialOverloading); 5320} 5321 5322static Sema::OwningExprResult Destroy(Sema &SemaRef, Expr *Fn, 5323 Expr **Args, unsigned NumArgs) { 5324 Fn->Destroy(SemaRef.Context); 5325 for (unsigned Arg = 0; Arg < NumArgs; ++Arg) 5326 Args[Arg]->Destroy(SemaRef.Context); 5327 return SemaRef.ExprError(); 5328} 5329 5330/// Attempts to recover from a call where no functions were found. 5331/// 5332/// Returns true if new candidates were found. 5333static Sema::OwningExprResult 5334BuildRecoveryCallExpr(Sema &SemaRef, Expr *Fn, 5335 UnresolvedLookupExpr *ULE, 5336 SourceLocation LParenLoc, 5337 Expr **Args, unsigned NumArgs, 5338 SourceLocation *CommaLocs, 5339 SourceLocation RParenLoc) { 5340 5341 CXXScopeSpec SS; 5342 if (ULE->getQualifier()) { 5343 SS.setScopeRep(ULE->getQualifier()); 5344 SS.setRange(ULE->getQualifierRange()); 5345 } 5346 5347 TemplateArgumentListInfo TABuffer; 5348 const TemplateArgumentListInfo *ExplicitTemplateArgs = 0; 5349 if (ULE->hasExplicitTemplateArgs()) { 5350 ULE->copyTemplateArgumentsInto(TABuffer); 5351 ExplicitTemplateArgs = &TABuffer; 5352 } 5353 5354 LookupResult R(SemaRef, ULE->getName(), ULE->getNameLoc(), 5355 Sema::LookupOrdinaryName); 5356 if (SemaRef.DiagnoseEmptyLookup(/*Scope=*/0, SS, R)) 5357 return Destroy(SemaRef, Fn, Args, NumArgs); 5358 5359 assert(!R.empty() && "lookup results empty despite recovery"); 5360 5361 // Build an implicit member call if appropriate. Just drop the 5362 // casts and such from the call, we don't really care. 5363 Sema::OwningExprResult NewFn = SemaRef.ExprError(); 5364 if ((*R.begin())->isCXXClassMember()) 5365 NewFn = SemaRef.BuildPossibleImplicitMemberExpr(SS, R, ExplicitTemplateArgs); 5366 else if (ExplicitTemplateArgs) 5367 NewFn = SemaRef.BuildTemplateIdExpr(SS, R, false, *ExplicitTemplateArgs); 5368 else 5369 NewFn = SemaRef.BuildDeclarationNameExpr(SS, R, false); 5370 5371 if (NewFn.isInvalid()) 5372 return Destroy(SemaRef, Fn, Args, NumArgs); 5373 5374 Fn->Destroy(SemaRef.Context); 5375 5376 // This shouldn't cause an infinite loop because we're giving it 5377 // an expression with non-empty lookup results, which should never 5378 // end up here. 5379 return SemaRef.ActOnCallExpr(/*Scope*/ 0, move(NewFn), LParenLoc, 5380 Sema::MultiExprArg(SemaRef, (void**) Args, NumArgs), 5381 CommaLocs, RParenLoc); 5382} 5383 5384/// ResolveOverloadedCallFn - Given the call expression that calls Fn 5385/// (which eventually refers to the declaration Func) and the call 5386/// arguments Args/NumArgs, attempt to resolve the function call down 5387/// to a specific function. If overload resolution succeeds, returns 5388/// the function declaration produced by overload 5389/// resolution. Otherwise, emits diagnostics, deletes all of the 5390/// arguments and Fn, and returns NULL. 5391Sema::OwningExprResult 5392Sema::BuildOverloadedCallExpr(Expr *Fn, UnresolvedLookupExpr *ULE, 5393 SourceLocation LParenLoc, 5394 Expr **Args, unsigned NumArgs, 5395 SourceLocation *CommaLocs, 5396 SourceLocation RParenLoc) { 5397#ifndef NDEBUG 5398 if (ULE->requiresADL()) { 5399 // To do ADL, we must have found an unqualified name. 5400 assert(!ULE->getQualifier() && "qualified name with ADL"); 5401 5402 // We don't perform ADL for implicit declarations of builtins. 5403 // Verify that this was correctly set up. 5404 FunctionDecl *F; 5405 if (ULE->decls_begin() + 1 == ULE->decls_end() && 5406 (F = dyn_cast<FunctionDecl>(*ULE->decls_begin())) && 5407 F->getBuiltinID() && F->isImplicit()) 5408 assert(0 && "performing ADL for builtin"); 5409 5410 // We don't perform ADL in C. 5411 assert(getLangOptions().CPlusPlus && "ADL enabled in C"); 5412 } 5413#endif 5414 5415 OverloadCandidateSet CandidateSet(Fn->getExprLoc()); 5416 5417 // Add the functions denoted by the callee to the set of candidate 5418 // functions, including those from argument-dependent lookup. 5419 AddOverloadedCallCandidates(ULE, Args, NumArgs, CandidateSet); 5420 5421 // If we found nothing, try to recover. 5422 // AddRecoveryCallCandidates diagnoses the error itself, so we just 5423 // bailout out if it fails. 5424 if (CandidateSet.empty()) 5425 return BuildRecoveryCallExpr(*this, Fn, ULE, LParenLoc, Args, NumArgs, 5426 CommaLocs, RParenLoc); 5427 5428 OverloadCandidateSet::iterator Best; 5429 switch (BestViableFunction(CandidateSet, Fn->getLocStart(), Best)) { 5430 case OR_Success: { 5431 FunctionDecl *FDecl = Best->Function; 5432 CheckUnresolvedLookupAccess(ULE, FDecl, Best->getAccess()); 5433 Fn = FixOverloadedFunctionReference(Fn, FDecl); 5434 return BuildResolvedCallExpr(Fn, FDecl, LParenLoc, Args, NumArgs, RParenLoc); 5435 } 5436 5437 case OR_No_Viable_Function: 5438 Diag(Fn->getSourceRange().getBegin(), 5439 diag::err_ovl_no_viable_function_in_call) 5440 << ULE->getName() << Fn->getSourceRange(); 5441 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 5442 break; 5443 5444 case OR_Ambiguous: 5445 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_ambiguous_call) 5446 << ULE->getName() << Fn->getSourceRange(); 5447 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, NumArgs); 5448 break; 5449 5450 case OR_Deleted: 5451 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_deleted_call) 5452 << Best->Function->isDeleted() 5453 << ULE->getName() 5454 << Fn->getSourceRange(); 5455 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 5456 break; 5457 } 5458 5459 // Overload resolution failed. Destroy all of the subexpressions and 5460 // return NULL. 5461 Fn->Destroy(Context); 5462 for (unsigned Arg = 0; Arg < NumArgs; ++Arg) 5463 Args[Arg]->Destroy(Context); 5464 return ExprError(); 5465} 5466 5467static bool IsOverloaded(const UnresolvedSetImpl &Functions) { 5468 return Functions.size() > 1 || 5469 (Functions.size() == 1 && isa<FunctionTemplateDecl>(*Functions.begin())); 5470} 5471 5472/// \brief Create a unary operation that may resolve to an overloaded 5473/// operator. 5474/// 5475/// \param OpLoc The location of the operator itself (e.g., '*'). 5476/// 5477/// \param OpcIn The UnaryOperator::Opcode that describes this 5478/// operator. 5479/// 5480/// \param Functions The set of non-member functions that will be 5481/// considered by overload resolution. The caller needs to build this 5482/// set based on the context using, e.g., 5483/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 5484/// set should not contain any member functions; those will be added 5485/// by CreateOverloadedUnaryOp(). 5486/// 5487/// \param input The input argument. 5488Sema::OwningExprResult 5489Sema::CreateOverloadedUnaryOp(SourceLocation OpLoc, unsigned OpcIn, 5490 const UnresolvedSetImpl &Fns, 5491 ExprArg input) { 5492 UnaryOperator::Opcode Opc = static_cast<UnaryOperator::Opcode>(OpcIn); 5493 Expr *Input = (Expr *)input.get(); 5494 5495 OverloadedOperatorKind Op = UnaryOperator::getOverloadedOperator(Opc); 5496 assert(Op != OO_None && "Invalid opcode for overloaded unary operator"); 5497 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 5498 5499 Expr *Args[2] = { Input, 0 }; 5500 unsigned NumArgs = 1; 5501 5502 // For post-increment and post-decrement, add the implicit '0' as 5503 // the second argument, so that we know this is a post-increment or 5504 // post-decrement. 5505 if (Opc == UnaryOperator::PostInc || Opc == UnaryOperator::PostDec) { 5506 llvm::APSInt Zero(Context.getTypeSize(Context.IntTy), false); 5507 Args[1] = new (Context) IntegerLiteral(Zero, Context.IntTy, 5508 SourceLocation()); 5509 NumArgs = 2; 5510 } 5511 5512 if (Input->isTypeDependent()) { 5513 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 5514 UnresolvedLookupExpr *Fn 5515 = UnresolvedLookupExpr::Create(Context, /*Dependent*/ true, NamingClass, 5516 0, SourceRange(), OpName, OpLoc, 5517 /*ADL*/ true, IsOverloaded(Fns)); 5518 Fn->addDecls(Fns.begin(), Fns.end()); 5519 5520 input.release(); 5521 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 5522 &Args[0], NumArgs, 5523 Context.DependentTy, 5524 OpLoc)); 5525 } 5526 5527 // Build an empty overload set. 5528 OverloadCandidateSet CandidateSet(OpLoc); 5529 5530 // Add the candidates from the given function set. 5531 AddFunctionCandidates(Fns, &Args[0], NumArgs, CandidateSet, false); 5532 5533 // Add operator candidates that are member functions. 5534 AddMemberOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 5535 5536 // Add candidates from ADL. 5537 AddArgumentDependentLookupCandidates(OpName, /*Operator*/ true, 5538 Args, NumArgs, 5539 /*ExplicitTemplateArgs*/ 0, 5540 CandidateSet); 5541 5542 // Add builtin operator candidates. 5543 AddBuiltinOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 5544 5545 // Perform overload resolution. 5546 OverloadCandidateSet::iterator Best; 5547 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 5548 case OR_Success: { 5549 // We found a built-in operator or an overloaded operator. 5550 FunctionDecl *FnDecl = Best->Function; 5551 5552 if (FnDecl) { 5553 // We matched an overloaded operator. Build a call to that 5554 // operator. 5555 5556 // Convert the arguments. 5557 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 5558 CheckMemberOperatorAccess(OpLoc, Args[0], Method, Best->getAccess()); 5559 5560 if (PerformObjectArgumentInitialization(Input, Method)) 5561 return ExprError(); 5562 } else { 5563 // Convert the arguments. 5564 OwningExprResult InputInit 5565 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 5566 FnDecl->getParamDecl(0)), 5567 SourceLocation(), 5568 move(input)); 5569 if (InputInit.isInvalid()) 5570 return ExprError(); 5571 5572 input = move(InputInit); 5573 Input = (Expr *)input.get(); 5574 } 5575 5576 // Determine the result type 5577 QualType ResultTy = FnDecl->getResultType().getNonReferenceType(); 5578 5579 // Build the actual expression node. 5580 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 5581 SourceLocation()); 5582 UsualUnaryConversions(FnExpr); 5583 5584 input.release(); 5585 Args[0] = Input; 5586 ExprOwningPtr<CallExpr> TheCall(this, 5587 new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 5588 Args, NumArgs, ResultTy, OpLoc)); 5589 5590 if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall.get(), 5591 FnDecl)) 5592 return ExprError(); 5593 5594 return MaybeBindToTemporary(TheCall.release()); 5595 } else { 5596 // We matched a built-in operator. Convert the arguments, then 5597 // break out so that we will build the appropriate built-in 5598 // operator node. 5599 if (PerformImplicitConversion(Input, Best->BuiltinTypes.ParamTypes[0], 5600 Best->Conversions[0], AA_Passing)) 5601 return ExprError(); 5602 5603 break; 5604 } 5605 } 5606 5607 case OR_No_Viable_Function: 5608 // No viable function; fall through to handling this as a 5609 // built-in operator, which will produce an error message for us. 5610 break; 5611 5612 case OR_Ambiguous: 5613 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 5614 << UnaryOperator::getOpcodeStr(Opc) 5615 << Input->getSourceRange(); 5616 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, NumArgs, 5617 UnaryOperator::getOpcodeStr(Opc), OpLoc); 5618 return ExprError(); 5619 5620 case OR_Deleted: 5621 Diag(OpLoc, diag::err_ovl_deleted_oper) 5622 << Best->Function->isDeleted() 5623 << UnaryOperator::getOpcodeStr(Opc) 5624 << Input->getSourceRange(); 5625 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 5626 return ExprError(); 5627 } 5628 5629 // Either we found no viable overloaded operator or we matched a 5630 // built-in operator. In either case, fall through to trying to 5631 // build a built-in operation. 5632 input.release(); 5633 return CreateBuiltinUnaryOp(OpLoc, Opc, Owned(Input)); 5634} 5635 5636/// \brief Create a binary operation that may resolve to an overloaded 5637/// operator. 5638/// 5639/// \param OpLoc The location of the operator itself (e.g., '+'). 5640/// 5641/// \param OpcIn The BinaryOperator::Opcode that describes this 5642/// operator. 5643/// 5644/// \param Functions The set of non-member functions that will be 5645/// considered by overload resolution. The caller needs to build this 5646/// set based on the context using, e.g., 5647/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 5648/// set should not contain any member functions; those will be added 5649/// by CreateOverloadedBinOp(). 5650/// 5651/// \param LHS Left-hand argument. 5652/// \param RHS Right-hand argument. 5653Sema::OwningExprResult 5654Sema::CreateOverloadedBinOp(SourceLocation OpLoc, 5655 unsigned OpcIn, 5656 const UnresolvedSetImpl &Fns, 5657 Expr *LHS, Expr *RHS) { 5658 Expr *Args[2] = { LHS, RHS }; 5659 LHS=RHS=0; //Please use only Args instead of LHS/RHS couple 5660 5661 BinaryOperator::Opcode Opc = static_cast<BinaryOperator::Opcode>(OpcIn); 5662 OverloadedOperatorKind Op = BinaryOperator::getOverloadedOperator(Opc); 5663 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 5664 5665 // If either side is type-dependent, create an appropriate dependent 5666 // expression. 5667 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 5668 if (Fns.empty()) { 5669 // If there are no functions to store, just build a dependent 5670 // BinaryOperator or CompoundAssignment. 5671 if (Opc <= BinaryOperator::Assign || Opc > BinaryOperator::OrAssign) 5672 return Owned(new (Context) BinaryOperator(Args[0], Args[1], Opc, 5673 Context.DependentTy, OpLoc)); 5674 5675 return Owned(new (Context) CompoundAssignOperator(Args[0], Args[1], Opc, 5676 Context.DependentTy, 5677 Context.DependentTy, 5678 Context.DependentTy, 5679 OpLoc)); 5680 } 5681 5682 // FIXME: save results of ADL from here? 5683 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 5684 UnresolvedLookupExpr *Fn 5685 = UnresolvedLookupExpr::Create(Context, /*Dependent*/ true, NamingClass, 5686 0, SourceRange(), OpName, OpLoc, 5687 /*ADL*/ true, IsOverloaded(Fns)); 5688 5689 Fn->addDecls(Fns.begin(), Fns.end()); 5690 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 5691 Args, 2, 5692 Context.DependentTy, 5693 OpLoc)); 5694 } 5695 5696 // If this is the .* operator, which is not overloadable, just 5697 // create a built-in binary operator. 5698 if (Opc == BinaryOperator::PtrMemD) 5699 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 5700 5701 // If this is the assignment operator, we only perform overload resolution 5702 // if the left-hand side is a class or enumeration type. This is actually 5703 // a hack. The standard requires that we do overload resolution between the 5704 // various built-in candidates, but as DR507 points out, this can lead to 5705 // problems. So we do it this way, which pretty much follows what GCC does. 5706 // Note that we go the traditional code path for compound assignment forms. 5707 if (Opc==BinaryOperator::Assign && !Args[0]->getType()->isOverloadableType()) 5708 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 5709 5710 // Build an empty overload set. 5711 OverloadCandidateSet CandidateSet(OpLoc); 5712 5713 // Add the candidates from the given function set. 5714 AddFunctionCandidates(Fns, Args, 2, CandidateSet, false); 5715 5716 // Add operator candidates that are member functions. 5717 AddMemberOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 5718 5719 // Add candidates from ADL. 5720 AddArgumentDependentLookupCandidates(OpName, /*Operator*/ true, 5721 Args, 2, 5722 /*ExplicitTemplateArgs*/ 0, 5723 CandidateSet); 5724 5725 // Add builtin operator candidates. 5726 AddBuiltinOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 5727 5728 // Perform overload resolution. 5729 OverloadCandidateSet::iterator Best; 5730 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 5731 case OR_Success: { 5732 // We found a built-in operator or an overloaded operator. 5733 FunctionDecl *FnDecl = Best->Function; 5734 5735 if (FnDecl) { 5736 // We matched an overloaded operator. Build a call to that 5737 // operator. 5738 5739 // Convert the arguments. 5740 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 5741 // Best->Access is only meaningful for class members. 5742 CheckMemberOperatorAccess(OpLoc, Args[0], Method, Best->getAccess()); 5743 5744 OwningExprResult Arg1 5745 = PerformCopyInitialization( 5746 InitializedEntity::InitializeParameter( 5747 FnDecl->getParamDecl(0)), 5748 SourceLocation(), 5749 Owned(Args[1])); 5750 if (Arg1.isInvalid()) 5751 return ExprError(); 5752 5753 if (PerformObjectArgumentInitialization(Args[0], Method)) 5754 return ExprError(); 5755 5756 Args[1] = RHS = Arg1.takeAs<Expr>(); 5757 } else { 5758 // Convert the arguments. 5759 OwningExprResult Arg0 5760 = PerformCopyInitialization( 5761 InitializedEntity::InitializeParameter( 5762 FnDecl->getParamDecl(0)), 5763 SourceLocation(), 5764 Owned(Args[0])); 5765 if (Arg0.isInvalid()) 5766 return ExprError(); 5767 5768 OwningExprResult Arg1 5769 = PerformCopyInitialization( 5770 InitializedEntity::InitializeParameter( 5771 FnDecl->getParamDecl(1)), 5772 SourceLocation(), 5773 Owned(Args[1])); 5774 if (Arg1.isInvalid()) 5775 return ExprError(); 5776 Args[0] = LHS = Arg0.takeAs<Expr>(); 5777 Args[1] = RHS = Arg1.takeAs<Expr>(); 5778 } 5779 5780 // Determine the result type 5781 QualType ResultTy 5782 = FnDecl->getType()->getAs<FunctionType>()->getResultType(); 5783 ResultTy = ResultTy.getNonReferenceType(); 5784 5785 // Build the actual expression node. 5786 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 5787 OpLoc); 5788 UsualUnaryConversions(FnExpr); 5789 5790 ExprOwningPtr<CXXOperatorCallExpr> 5791 TheCall(this, new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 5792 Args, 2, ResultTy, 5793 OpLoc)); 5794 5795 if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall.get(), 5796 FnDecl)) 5797 return ExprError(); 5798 5799 return MaybeBindToTemporary(TheCall.release()); 5800 } else { 5801 // We matched a built-in operator. Convert the arguments, then 5802 // break out so that we will build the appropriate built-in 5803 // operator node. 5804 if (PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 5805 Best->Conversions[0], AA_Passing) || 5806 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 5807 Best->Conversions[1], AA_Passing)) 5808 return ExprError(); 5809 5810 break; 5811 } 5812 } 5813 5814 case OR_No_Viable_Function: { 5815 // C++ [over.match.oper]p9: 5816 // If the operator is the operator , [...] and there are no 5817 // viable functions, then the operator is assumed to be the 5818 // built-in operator and interpreted according to clause 5. 5819 if (Opc == BinaryOperator::Comma) 5820 break; 5821 5822 // For class as left operand for assignment or compound assigment operator 5823 // do not fall through to handling in built-in, but report that no overloaded 5824 // assignment operator found 5825 OwningExprResult Result = ExprError(); 5826 if (Args[0]->getType()->isRecordType() && 5827 Opc >= BinaryOperator::Assign && Opc <= BinaryOperator::OrAssign) { 5828 Diag(OpLoc, diag::err_ovl_no_viable_oper) 5829 << BinaryOperator::getOpcodeStr(Opc) 5830 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 5831 } else { 5832 // No viable function; try to create a built-in operation, which will 5833 // produce an error. Then, show the non-viable candidates. 5834 Result = CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 5835 } 5836 assert(Result.isInvalid() && 5837 "C++ binary operator overloading is missing candidates!"); 5838 if (Result.isInvalid()) 5839 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2, 5840 BinaryOperator::getOpcodeStr(Opc), OpLoc); 5841 return move(Result); 5842 } 5843 5844 case OR_Ambiguous: 5845 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 5846 << BinaryOperator::getOpcodeStr(Opc) 5847 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 5848 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, 2, 5849 BinaryOperator::getOpcodeStr(Opc), OpLoc); 5850 return ExprError(); 5851 5852 case OR_Deleted: 5853 Diag(OpLoc, diag::err_ovl_deleted_oper) 5854 << Best->Function->isDeleted() 5855 << BinaryOperator::getOpcodeStr(Opc) 5856 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 5857 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2); 5858 return ExprError(); 5859 } 5860 5861 // We matched a built-in operator; build it. 5862 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 5863} 5864 5865Action::OwningExprResult 5866Sema::CreateOverloadedArraySubscriptExpr(SourceLocation LLoc, 5867 SourceLocation RLoc, 5868 ExprArg Base, ExprArg Idx) { 5869 Expr *Args[2] = { static_cast<Expr*>(Base.get()), 5870 static_cast<Expr*>(Idx.get()) }; 5871 DeclarationName OpName = 5872 Context.DeclarationNames.getCXXOperatorName(OO_Subscript); 5873 5874 // If either side is type-dependent, create an appropriate dependent 5875 // expression. 5876 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 5877 5878 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 5879 UnresolvedLookupExpr *Fn 5880 = UnresolvedLookupExpr::Create(Context, /*Dependent*/ true, NamingClass, 5881 0, SourceRange(), OpName, LLoc, 5882 /*ADL*/ true, /*Overloaded*/ false); 5883 // Can't add any actual overloads yet 5884 5885 Base.release(); 5886 Idx.release(); 5887 return Owned(new (Context) CXXOperatorCallExpr(Context, OO_Subscript, Fn, 5888 Args, 2, 5889 Context.DependentTy, 5890 RLoc)); 5891 } 5892 5893 // Build an empty overload set. 5894 OverloadCandidateSet CandidateSet(LLoc); 5895 5896 // Subscript can only be overloaded as a member function. 5897 5898 // Add operator candidates that are member functions. 5899 AddMemberOperatorCandidates(OO_Subscript, LLoc, Args, 2, CandidateSet); 5900 5901 // Add builtin operator candidates. 5902 AddBuiltinOperatorCandidates(OO_Subscript, LLoc, Args, 2, CandidateSet); 5903 5904 // Perform overload resolution. 5905 OverloadCandidateSet::iterator Best; 5906 switch (BestViableFunction(CandidateSet, LLoc, Best)) { 5907 case OR_Success: { 5908 // We found a built-in operator or an overloaded operator. 5909 FunctionDecl *FnDecl = Best->Function; 5910 5911 if (FnDecl) { 5912 // We matched an overloaded operator. Build a call to that 5913 // operator. 5914 5915 CheckMemberOperatorAccess(LLoc, Args[0], FnDecl, Best->getAccess()); 5916 5917 // Convert the arguments. 5918 CXXMethodDecl *Method = cast<CXXMethodDecl>(FnDecl); 5919 if (PerformObjectArgumentInitialization(Args[0], Method)) 5920 return ExprError(); 5921 5922 // Convert the arguments. 5923 OwningExprResult InputInit 5924 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 5925 FnDecl->getParamDecl(0)), 5926 SourceLocation(), 5927 Owned(Args[1])); 5928 if (InputInit.isInvalid()) 5929 return ExprError(); 5930 5931 Args[1] = InputInit.takeAs<Expr>(); 5932 5933 // Determine the result type 5934 QualType ResultTy 5935 = FnDecl->getType()->getAs<FunctionType>()->getResultType(); 5936 ResultTy = ResultTy.getNonReferenceType(); 5937 5938 // Build the actual expression node. 5939 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 5940 LLoc); 5941 UsualUnaryConversions(FnExpr); 5942 5943 Base.release(); 5944 Idx.release(); 5945 ExprOwningPtr<CXXOperatorCallExpr> 5946 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Subscript, 5947 FnExpr, Args, 2, 5948 ResultTy, RLoc)); 5949 5950 if (CheckCallReturnType(FnDecl->getResultType(), LLoc, TheCall.get(), 5951 FnDecl)) 5952 return ExprError(); 5953 5954 return MaybeBindToTemporary(TheCall.release()); 5955 } else { 5956 // We matched a built-in operator. Convert the arguments, then 5957 // break out so that we will build the appropriate built-in 5958 // operator node. 5959 if (PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 5960 Best->Conversions[0], AA_Passing) || 5961 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 5962 Best->Conversions[1], AA_Passing)) 5963 return ExprError(); 5964 5965 break; 5966 } 5967 } 5968 5969 case OR_No_Viable_Function: { 5970 if (CandidateSet.empty()) 5971 Diag(LLoc, diag::err_ovl_no_oper) 5972 << Args[0]->getType() << /*subscript*/ 0 5973 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 5974 else 5975 Diag(LLoc, diag::err_ovl_no_viable_subscript) 5976 << Args[0]->getType() 5977 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 5978 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2, 5979 "[]", LLoc); 5980 return ExprError(); 5981 } 5982 5983 case OR_Ambiguous: 5984 Diag(LLoc, diag::err_ovl_ambiguous_oper) 5985 << "[]" << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 5986 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, 2, 5987 "[]", LLoc); 5988 return ExprError(); 5989 5990 case OR_Deleted: 5991 Diag(LLoc, diag::err_ovl_deleted_oper) 5992 << Best->Function->isDeleted() << "[]" 5993 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 5994 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2, 5995 "[]", LLoc); 5996 return ExprError(); 5997 } 5998 5999 // We matched a built-in operator; build it. 6000 Base.release(); 6001 Idx.release(); 6002 return CreateBuiltinArraySubscriptExpr(Owned(Args[0]), LLoc, 6003 Owned(Args[1]), RLoc); 6004} 6005 6006/// BuildCallToMemberFunction - Build a call to a member 6007/// function. MemExpr is the expression that refers to the member 6008/// function (and includes the object parameter), Args/NumArgs are the 6009/// arguments to the function call (not including the object 6010/// parameter). The caller needs to validate that the member 6011/// expression refers to a member function or an overloaded member 6012/// function. 6013Sema::OwningExprResult 6014Sema::BuildCallToMemberFunction(Scope *S, Expr *MemExprE, 6015 SourceLocation LParenLoc, Expr **Args, 6016 unsigned NumArgs, SourceLocation *CommaLocs, 6017 SourceLocation RParenLoc) { 6018 // Dig out the member expression. This holds both the object 6019 // argument and the member function we're referring to. 6020 Expr *NakedMemExpr = MemExprE->IgnoreParens(); 6021 6022 MemberExpr *MemExpr; 6023 CXXMethodDecl *Method = 0; 6024 if (isa<MemberExpr>(NakedMemExpr)) { 6025 MemExpr = cast<MemberExpr>(NakedMemExpr); 6026 Method = cast<CXXMethodDecl>(MemExpr->getMemberDecl()); 6027 } else { 6028 UnresolvedMemberExpr *UnresExpr = cast<UnresolvedMemberExpr>(NakedMemExpr); 6029 6030 QualType ObjectType = UnresExpr->getBaseType(); 6031 6032 // Add overload candidates 6033 OverloadCandidateSet CandidateSet(UnresExpr->getMemberLoc()); 6034 6035 // FIXME: avoid copy. 6036 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 6037 if (UnresExpr->hasExplicitTemplateArgs()) { 6038 UnresExpr->copyTemplateArgumentsInto(TemplateArgsBuffer); 6039 TemplateArgs = &TemplateArgsBuffer; 6040 } 6041 6042 for (UnresolvedMemberExpr::decls_iterator I = UnresExpr->decls_begin(), 6043 E = UnresExpr->decls_end(); I != E; ++I) { 6044 6045 NamedDecl *Func = *I; 6046 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(Func->getDeclContext()); 6047 if (isa<UsingShadowDecl>(Func)) 6048 Func = cast<UsingShadowDecl>(Func)->getTargetDecl(); 6049 6050 if ((Method = dyn_cast<CXXMethodDecl>(Func))) { 6051 // If explicit template arguments were provided, we can't call a 6052 // non-template member function. 6053 if (TemplateArgs) 6054 continue; 6055 6056 AddMethodCandidate(Method, I.getAccess(), ActingDC, ObjectType, 6057 Args, NumArgs, 6058 CandidateSet, /*SuppressUserConversions=*/false); 6059 } else { 6060 AddMethodTemplateCandidate(cast<FunctionTemplateDecl>(Func), 6061 I.getAccess(), ActingDC, TemplateArgs, 6062 ObjectType, Args, NumArgs, 6063 CandidateSet, 6064 /*SuppressUsedConversions=*/false); 6065 } 6066 } 6067 6068 DeclarationName DeclName = UnresExpr->getMemberName(); 6069 6070 OverloadCandidateSet::iterator Best; 6071 switch (BestViableFunction(CandidateSet, UnresExpr->getLocStart(), Best)) { 6072 case OR_Success: 6073 Method = cast<CXXMethodDecl>(Best->Function); 6074 CheckUnresolvedMemberAccess(UnresExpr, Method, Best->getAccess()); 6075 break; 6076 6077 case OR_No_Viable_Function: 6078 Diag(UnresExpr->getMemberLoc(), 6079 diag::err_ovl_no_viable_member_function_in_call) 6080 << DeclName << MemExprE->getSourceRange(); 6081 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6082 // FIXME: Leaking incoming expressions! 6083 return ExprError(); 6084 6085 case OR_Ambiguous: 6086 Diag(UnresExpr->getMemberLoc(), diag::err_ovl_ambiguous_member_call) 6087 << DeclName << MemExprE->getSourceRange(); 6088 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6089 // FIXME: Leaking incoming expressions! 6090 return ExprError(); 6091 6092 case OR_Deleted: 6093 Diag(UnresExpr->getMemberLoc(), diag::err_ovl_deleted_member_call) 6094 << Best->Function->isDeleted() 6095 << DeclName << MemExprE->getSourceRange(); 6096 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6097 // FIXME: Leaking incoming expressions! 6098 return ExprError(); 6099 } 6100 6101 MemExprE = FixOverloadedFunctionReference(MemExprE, Method); 6102 6103 // If overload resolution picked a static member, build a 6104 // non-member call based on that function. 6105 if (Method->isStatic()) { 6106 return BuildResolvedCallExpr(MemExprE, Method, LParenLoc, 6107 Args, NumArgs, RParenLoc); 6108 } 6109 6110 MemExpr = cast<MemberExpr>(MemExprE->IgnoreParens()); 6111 } 6112 6113 assert(Method && "Member call to something that isn't a method?"); 6114 ExprOwningPtr<CXXMemberCallExpr> 6115 TheCall(this, new (Context) CXXMemberCallExpr(Context, MemExprE, Args, 6116 NumArgs, 6117 Method->getResultType().getNonReferenceType(), 6118 RParenLoc)); 6119 6120 // Check for a valid return type. 6121 if (CheckCallReturnType(Method->getResultType(), MemExpr->getMemberLoc(), 6122 TheCall.get(), Method)) 6123 return ExprError(); 6124 6125 // Convert the object argument (for a non-static member function call). 6126 Expr *ObjectArg = MemExpr->getBase(); 6127 if (!Method->isStatic() && 6128 PerformObjectArgumentInitialization(ObjectArg, Method)) 6129 return ExprError(); 6130 MemExpr->setBase(ObjectArg); 6131 6132 // Convert the rest of the arguments 6133 const FunctionProtoType *Proto = cast<FunctionProtoType>(Method->getType()); 6134 if (ConvertArgumentsForCall(&*TheCall, MemExpr, Method, Proto, Args, NumArgs, 6135 RParenLoc)) 6136 return ExprError(); 6137 6138 if (CheckFunctionCall(Method, TheCall.get())) 6139 return ExprError(); 6140 6141 return MaybeBindToTemporary(TheCall.release()); 6142} 6143 6144/// BuildCallToObjectOfClassType - Build a call to an object of class 6145/// type (C++ [over.call.object]), which can end up invoking an 6146/// overloaded function call operator (@c operator()) or performing a 6147/// user-defined conversion on the object argument. 6148Sema::ExprResult 6149Sema::BuildCallToObjectOfClassType(Scope *S, Expr *Object, 6150 SourceLocation LParenLoc, 6151 Expr **Args, unsigned NumArgs, 6152 SourceLocation *CommaLocs, 6153 SourceLocation RParenLoc) { 6154 assert(Object->getType()->isRecordType() && "Requires object type argument"); 6155 const RecordType *Record = Object->getType()->getAs<RecordType>(); 6156 6157 // C++ [over.call.object]p1: 6158 // If the primary-expression E in the function call syntax 6159 // evaluates to a class object of type "cv T", then the set of 6160 // candidate functions includes at least the function call 6161 // operators of T. The function call operators of T are obtained by 6162 // ordinary lookup of the name operator() in the context of 6163 // (E).operator(). 6164 OverloadCandidateSet CandidateSet(LParenLoc); 6165 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Call); 6166 6167 if (RequireCompleteType(LParenLoc, Object->getType(), 6168 PartialDiagnostic(diag::err_incomplete_object_call) 6169 << Object->getSourceRange())) 6170 return true; 6171 6172 LookupResult R(*this, OpName, LParenLoc, LookupOrdinaryName); 6173 LookupQualifiedName(R, Record->getDecl()); 6174 R.suppressDiagnostics(); 6175 6176 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 6177 Oper != OperEnd; ++Oper) { 6178 AddMethodCandidate(*Oper, Oper.getAccess(), Object->getType(), 6179 Args, NumArgs, CandidateSet, 6180 /*SuppressUserConversions=*/ false); 6181 } 6182 6183 // C++ [over.call.object]p2: 6184 // In addition, for each conversion function declared in T of the 6185 // form 6186 // 6187 // operator conversion-type-id () cv-qualifier; 6188 // 6189 // where cv-qualifier is the same cv-qualification as, or a 6190 // greater cv-qualification than, cv, and where conversion-type-id 6191 // denotes the type "pointer to function of (P1,...,Pn) returning 6192 // R", or the type "reference to pointer to function of 6193 // (P1,...,Pn) returning R", or the type "reference to function 6194 // of (P1,...,Pn) returning R", a surrogate call function [...] 6195 // is also considered as a candidate function. Similarly, 6196 // surrogate call functions are added to the set of candidate 6197 // functions for each conversion function declared in an 6198 // accessible base class provided the function is not hidden 6199 // within T by another intervening declaration. 6200 const UnresolvedSetImpl *Conversions 6201 = cast<CXXRecordDecl>(Record->getDecl())->getVisibleConversionFunctions(); 6202 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 6203 E = Conversions->end(); I != E; ++I) { 6204 NamedDecl *D = *I; 6205 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext()); 6206 if (isa<UsingShadowDecl>(D)) 6207 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 6208 6209 // Skip over templated conversion functions; they aren't 6210 // surrogates. 6211 if (isa<FunctionTemplateDecl>(D)) 6212 continue; 6213 6214 CXXConversionDecl *Conv = cast<CXXConversionDecl>(D); 6215 6216 // Strip the reference type (if any) and then the pointer type (if 6217 // any) to get down to what might be a function type. 6218 QualType ConvType = Conv->getConversionType().getNonReferenceType(); 6219 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 6220 ConvType = ConvPtrType->getPointeeType(); 6221 6222 if (const FunctionProtoType *Proto = ConvType->getAs<FunctionProtoType>()) 6223 AddSurrogateCandidate(Conv, I.getAccess(), ActingContext, Proto, 6224 Object->getType(), Args, NumArgs, 6225 CandidateSet); 6226 } 6227 6228 // Perform overload resolution. 6229 OverloadCandidateSet::iterator Best; 6230 switch (BestViableFunction(CandidateSet, Object->getLocStart(), Best)) { 6231 case OR_Success: 6232 // Overload resolution succeeded; we'll build the appropriate call 6233 // below. 6234 break; 6235 6236 case OR_No_Viable_Function: 6237 if (CandidateSet.empty()) 6238 Diag(Object->getSourceRange().getBegin(), diag::err_ovl_no_oper) 6239 << Object->getType() << /*call*/ 1 6240 << Object->getSourceRange(); 6241 else 6242 Diag(Object->getSourceRange().getBegin(), 6243 diag::err_ovl_no_viable_object_call) 6244 << Object->getType() << Object->getSourceRange(); 6245 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6246 break; 6247 6248 case OR_Ambiguous: 6249 Diag(Object->getSourceRange().getBegin(), 6250 diag::err_ovl_ambiguous_object_call) 6251 << Object->getType() << Object->getSourceRange(); 6252 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, NumArgs); 6253 break; 6254 6255 case OR_Deleted: 6256 Diag(Object->getSourceRange().getBegin(), 6257 diag::err_ovl_deleted_object_call) 6258 << Best->Function->isDeleted() 6259 << Object->getType() << Object->getSourceRange(); 6260 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6261 break; 6262 } 6263 6264 if (Best == CandidateSet.end()) { 6265 // We had an error; delete all of the subexpressions and return 6266 // the error. 6267 Object->Destroy(Context); 6268 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 6269 Args[ArgIdx]->Destroy(Context); 6270 return true; 6271 } 6272 6273 if (Best->Function == 0) { 6274 // Since there is no function declaration, this is one of the 6275 // surrogate candidates. Dig out the conversion function. 6276 CXXConversionDecl *Conv 6277 = cast<CXXConversionDecl>( 6278 Best->Conversions[0].UserDefined.ConversionFunction); 6279 6280 CheckMemberOperatorAccess(LParenLoc, Object, Conv, Best->getAccess()); 6281 6282 // We selected one of the surrogate functions that converts the 6283 // object parameter to a function pointer. Perform the conversion 6284 // on the object argument, then let ActOnCallExpr finish the job. 6285 6286 // Create an implicit member expr to refer to the conversion operator. 6287 // and then call it. 6288 CXXMemberCallExpr *CE = BuildCXXMemberCallExpr(Object, Conv); 6289 6290 return ActOnCallExpr(S, ExprArg(*this, CE), LParenLoc, 6291 MultiExprArg(*this, (ExprTy**)Args, NumArgs), 6292 CommaLocs, RParenLoc).release(); 6293 } 6294 6295 CheckMemberOperatorAccess(LParenLoc, Object, 6296 Best->Function, Best->getAccess()); 6297 6298 // We found an overloaded operator(). Build a CXXOperatorCallExpr 6299 // that calls this method, using Object for the implicit object 6300 // parameter and passing along the remaining arguments. 6301 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 6302 const FunctionProtoType *Proto = Method->getType()->getAs<FunctionProtoType>(); 6303 6304 unsigned NumArgsInProto = Proto->getNumArgs(); 6305 unsigned NumArgsToCheck = NumArgs; 6306 6307 // Build the full argument list for the method call (the 6308 // implicit object parameter is placed at the beginning of the 6309 // list). 6310 Expr **MethodArgs; 6311 if (NumArgs < NumArgsInProto) { 6312 NumArgsToCheck = NumArgsInProto; 6313 MethodArgs = new Expr*[NumArgsInProto + 1]; 6314 } else { 6315 MethodArgs = new Expr*[NumArgs + 1]; 6316 } 6317 MethodArgs[0] = Object; 6318 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 6319 MethodArgs[ArgIdx + 1] = Args[ArgIdx]; 6320 6321 Expr *NewFn = new (Context) DeclRefExpr(Method, Method->getType(), 6322 SourceLocation()); 6323 UsualUnaryConversions(NewFn); 6324 6325 // Once we've built TheCall, all of the expressions are properly 6326 // owned. 6327 QualType ResultTy = Method->getResultType().getNonReferenceType(); 6328 ExprOwningPtr<CXXOperatorCallExpr> 6329 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Call, NewFn, 6330 MethodArgs, NumArgs + 1, 6331 ResultTy, RParenLoc)); 6332 delete [] MethodArgs; 6333 6334 if (CheckCallReturnType(Method->getResultType(), LParenLoc, TheCall.get(), 6335 Method)) 6336 return true; 6337 6338 // We may have default arguments. If so, we need to allocate more 6339 // slots in the call for them. 6340 if (NumArgs < NumArgsInProto) 6341 TheCall->setNumArgs(Context, NumArgsInProto + 1); 6342 else if (NumArgs > NumArgsInProto) 6343 NumArgsToCheck = NumArgsInProto; 6344 6345 bool IsError = false; 6346 6347 // Initialize the implicit object parameter. 6348 IsError |= PerformObjectArgumentInitialization(Object, Method); 6349 TheCall->setArg(0, Object); 6350 6351 6352 // Check the argument types. 6353 for (unsigned i = 0; i != NumArgsToCheck; i++) { 6354 Expr *Arg; 6355 if (i < NumArgs) { 6356 Arg = Args[i]; 6357 6358 // Pass the argument. 6359 6360 OwningExprResult InputInit 6361 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 6362 Method->getParamDecl(i)), 6363 SourceLocation(), Owned(Arg)); 6364 6365 IsError |= InputInit.isInvalid(); 6366 Arg = InputInit.takeAs<Expr>(); 6367 } else { 6368 OwningExprResult DefArg 6369 = BuildCXXDefaultArgExpr(LParenLoc, Method, Method->getParamDecl(i)); 6370 if (DefArg.isInvalid()) { 6371 IsError = true; 6372 break; 6373 } 6374 6375 Arg = DefArg.takeAs<Expr>(); 6376 } 6377 6378 TheCall->setArg(i + 1, Arg); 6379 } 6380 6381 // If this is a variadic call, handle args passed through "...". 6382 if (Proto->isVariadic()) { 6383 // Promote the arguments (C99 6.5.2.2p7). 6384 for (unsigned i = NumArgsInProto; i != NumArgs; i++) { 6385 Expr *Arg = Args[i]; 6386 IsError |= DefaultVariadicArgumentPromotion(Arg, VariadicMethod); 6387 TheCall->setArg(i + 1, Arg); 6388 } 6389 } 6390 6391 if (IsError) return true; 6392 6393 if (CheckFunctionCall(Method, TheCall.get())) 6394 return true; 6395 6396 return MaybeBindToTemporary(TheCall.release()).release(); 6397} 6398 6399/// BuildOverloadedArrowExpr - Build a call to an overloaded @c operator-> 6400/// (if one exists), where @c Base is an expression of class type and 6401/// @c Member is the name of the member we're trying to find. 6402Sema::OwningExprResult 6403Sema::BuildOverloadedArrowExpr(Scope *S, ExprArg BaseIn, SourceLocation OpLoc) { 6404 Expr *Base = static_cast<Expr *>(BaseIn.get()); 6405 assert(Base->getType()->isRecordType() && "left-hand side must have class type"); 6406 6407 SourceLocation Loc = Base->getExprLoc(); 6408 6409 // C++ [over.ref]p1: 6410 // 6411 // [...] An expression x->m is interpreted as (x.operator->())->m 6412 // for a class object x of type T if T::operator->() exists and if 6413 // the operator is selected as the best match function by the 6414 // overload resolution mechanism (13.3). 6415 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Arrow); 6416 OverloadCandidateSet CandidateSet(Loc); 6417 const RecordType *BaseRecord = Base->getType()->getAs<RecordType>(); 6418 6419 if (RequireCompleteType(Loc, Base->getType(), 6420 PDiag(diag::err_typecheck_incomplete_tag) 6421 << Base->getSourceRange())) 6422 return ExprError(); 6423 6424 LookupResult R(*this, OpName, OpLoc, LookupOrdinaryName); 6425 LookupQualifiedName(R, BaseRecord->getDecl()); 6426 R.suppressDiagnostics(); 6427 6428 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 6429 Oper != OperEnd; ++Oper) { 6430 NamedDecl *D = *Oper; 6431 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext()); 6432 if (isa<UsingShadowDecl>(D)) 6433 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 6434 6435 AddMethodCandidate(cast<CXXMethodDecl>(D), Oper.getAccess(), ActingContext, 6436 Base->getType(), 0, 0, CandidateSet, 6437 /*SuppressUserConversions=*/false); 6438 } 6439 6440 // Perform overload resolution. 6441 OverloadCandidateSet::iterator Best; 6442 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 6443 case OR_Success: 6444 // Overload resolution succeeded; we'll build the call below. 6445 break; 6446 6447 case OR_No_Viable_Function: 6448 if (CandidateSet.empty()) 6449 Diag(OpLoc, diag::err_typecheck_member_reference_arrow) 6450 << Base->getType() << Base->getSourceRange(); 6451 else 6452 Diag(OpLoc, diag::err_ovl_no_viable_oper) 6453 << "operator->" << Base->getSourceRange(); 6454 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, &Base, 1); 6455 return ExprError(); 6456 6457 case OR_Ambiguous: 6458 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 6459 << "->" << Base->getSourceRange(); 6460 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, &Base, 1); 6461 return ExprError(); 6462 6463 case OR_Deleted: 6464 Diag(OpLoc, diag::err_ovl_deleted_oper) 6465 << Best->Function->isDeleted() 6466 << "->" << Base->getSourceRange(); 6467 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, &Base, 1); 6468 return ExprError(); 6469 } 6470 6471 // Convert the object parameter. 6472 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 6473 if (PerformObjectArgumentInitialization(Base, Method)) 6474 return ExprError(); 6475 6476 // No concerns about early exits now. 6477 BaseIn.release(); 6478 6479 // Build the operator call. 6480 Expr *FnExpr = new (Context) DeclRefExpr(Method, Method->getType(), 6481 SourceLocation()); 6482 UsualUnaryConversions(FnExpr); 6483 6484 QualType ResultTy = Method->getResultType().getNonReferenceType(); 6485 ExprOwningPtr<CXXOperatorCallExpr> 6486 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Arrow, FnExpr, 6487 &Base, 1, ResultTy, OpLoc)); 6488 6489 if (CheckCallReturnType(Method->getResultType(), OpLoc, TheCall.get(), 6490 Method)) 6491 return ExprError(); 6492 return move(TheCall); 6493} 6494 6495/// FixOverloadedFunctionReference - E is an expression that refers to 6496/// a C++ overloaded function (possibly with some parentheses and 6497/// perhaps a '&' around it). We have resolved the overloaded function 6498/// to the function declaration Fn, so patch up the expression E to 6499/// refer (possibly indirectly) to Fn. Returns the new expr. 6500Expr *Sema::FixOverloadedFunctionReference(Expr *E, FunctionDecl *Fn) { 6501 if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) { 6502 Expr *SubExpr = FixOverloadedFunctionReference(PE->getSubExpr(), Fn); 6503 if (SubExpr == PE->getSubExpr()) 6504 return PE->Retain(); 6505 6506 return new (Context) ParenExpr(PE->getLParen(), PE->getRParen(), SubExpr); 6507 } 6508 6509 if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) { 6510 Expr *SubExpr = FixOverloadedFunctionReference(ICE->getSubExpr(), Fn); 6511 assert(Context.hasSameType(ICE->getSubExpr()->getType(), 6512 SubExpr->getType()) && 6513 "Implicit cast type cannot be determined from overload"); 6514 if (SubExpr == ICE->getSubExpr()) 6515 return ICE->Retain(); 6516 6517 return new (Context) ImplicitCastExpr(ICE->getType(), 6518 ICE->getCastKind(), 6519 SubExpr, 6520 ICE->isLvalueCast()); 6521 } 6522 6523 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(E)) { 6524 assert(UnOp->getOpcode() == UnaryOperator::AddrOf && 6525 "Can only take the address of an overloaded function"); 6526 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 6527 if (Method->isStatic()) { 6528 // Do nothing: static member functions aren't any different 6529 // from non-member functions. 6530 } else { 6531 // Fix the sub expression, which really has to be an 6532 // UnresolvedLookupExpr holding an overloaded member function 6533 // or template. 6534 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(), Fn); 6535 if (SubExpr == UnOp->getSubExpr()) 6536 return UnOp->Retain(); 6537 6538 assert(isa<DeclRefExpr>(SubExpr) 6539 && "fixed to something other than a decl ref"); 6540 assert(cast<DeclRefExpr>(SubExpr)->getQualifier() 6541 && "fixed to a member ref with no nested name qualifier"); 6542 6543 // We have taken the address of a pointer to member 6544 // function. Perform the computation here so that we get the 6545 // appropriate pointer to member type. 6546 QualType ClassType 6547 = Context.getTypeDeclType(cast<RecordDecl>(Method->getDeclContext())); 6548 QualType MemPtrType 6549 = Context.getMemberPointerType(Fn->getType(), ClassType.getTypePtr()); 6550 6551 return new (Context) UnaryOperator(SubExpr, UnaryOperator::AddrOf, 6552 MemPtrType, UnOp->getOperatorLoc()); 6553 } 6554 } 6555 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(), Fn); 6556 if (SubExpr == UnOp->getSubExpr()) 6557 return UnOp->Retain(); 6558 6559 return new (Context) UnaryOperator(SubExpr, UnaryOperator::AddrOf, 6560 Context.getPointerType(SubExpr->getType()), 6561 UnOp->getOperatorLoc()); 6562 } 6563 6564 if (UnresolvedLookupExpr *ULE = dyn_cast<UnresolvedLookupExpr>(E)) { 6565 // FIXME: avoid copy. 6566 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 6567 if (ULE->hasExplicitTemplateArgs()) { 6568 ULE->copyTemplateArgumentsInto(TemplateArgsBuffer); 6569 TemplateArgs = &TemplateArgsBuffer; 6570 } 6571 6572 return DeclRefExpr::Create(Context, 6573 ULE->getQualifier(), 6574 ULE->getQualifierRange(), 6575 Fn, 6576 ULE->getNameLoc(), 6577 Fn->getType(), 6578 TemplateArgs); 6579 } 6580 6581 if (UnresolvedMemberExpr *MemExpr = dyn_cast<UnresolvedMemberExpr>(E)) { 6582 // FIXME: avoid copy. 6583 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 6584 if (MemExpr->hasExplicitTemplateArgs()) { 6585 MemExpr->copyTemplateArgumentsInto(TemplateArgsBuffer); 6586 TemplateArgs = &TemplateArgsBuffer; 6587 } 6588 6589 Expr *Base; 6590 6591 // If we're filling in 6592 if (MemExpr->isImplicitAccess()) { 6593 if (cast<CXXMethodDecl>(Fn)->isStatic()) { 6594 return DeclRefExpr::Create(Context, 6595 MemExpr->getQualifier(), 6596 MemExpr->getQualifierRange(), 6597 Fn, 6598 MemExpr->getMemberLoc(), 6599 Fn->getType(), 6600 TemplateArgs); 6601 } else { 6602 SourceLocation Loc = MemExpr->getMemberLoc(); 6603 if (MemExpr->getQualifier()) 6604 Loc = MemExpr->getQualifierRange().getBegin(); 6605 Base = new (Context) CXXThisExpr(Loc, 6606 MemExpr->getBaseType(), 6607 /*isImplicit=*/true); 6608 } 6609 } else 6610 Base = MemExpr->getBase()->Retain(); 6611 6612 return MemberExpr::Create(Context, Base, 6613 MemExpr->isArrow(), 6614 MemExpr->getQualifier(), 6615 MemExpr->getQualifierRange(), 6616 Fn, 6617 MemExpr->getMemberLoc(), 6618 TemplateArgs, 6619 Fn->getType()); 6620 } 6621 6622 assert(false && "Invalid reference to overloaded function"); 6623 return E->Retain(); 6624} 6625 6626Sema::OwningExprResult Sema::FixOverloadedFunctionReference(OwningExprResult E, 6627 FunctionDecl *Fn) { 6628 return Owned(FixOverloadedFunctionReference((Expr *)E.get(), Fn)); 6629} 6630 6631} // end namespace clang 6632