SemaOverload.cpp revision 74e386e8ead6654fade7f8661e28e10100dd4005
1//===--- SemaOverload.cpp - C++ Overloading ---------------------*- C++ -*-===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This file provides Sema routines for C++ overloading. 11// 12//===----------------------------------------------------------------------===// 13 14#include "Sema.h" 15#include "Lookup.h" 16#include "SemaInit.h" 17#include "clang/Basic/Diagnostic.h" 18#include "clang/Lex/Preprocessor.h" 19#include "clang/AST/ASTContext.h" 20#include "clang/AST/CXXInheritance.h" 21#include "clang/AST/Expr.h" 22#include "clang/AST/ExprCXX.h" 23#include "clang/AST/TypeOrdering.h" 24#include "clang/Basic/PartialDiagnostic.h" 25#include "llvm/ADT/SmallPtrSet.h" 26#include "llvm/ADT/STLExtras.h" 27#include <algorithm> 28 29namespace clang { 30 31/// GetConversionCategory - Retrieve the implicit conversion 32/// category corresponding to the given implicit conversion kind. 33ImplicitConversionCategory 34GetConversionCategory(ImplicitConversionKind Kind) { 35 static const ImplicitConversionCategory 36 Category[(int)ICK_Num_Conversion_Kinds] = { 37 ICC_Identity, 38 ICC_Lvalue_Transformation, 39 ICC_Lvalue_Transformation, 40 ICC_Lvalue_Transformation, 41 ICC_Identity, 42 ICC_Qualification_Adjustment, 43 ICC_Promotion, 44 ICC_Promotion, 45 ICC_Promotion, 46 ICC_Conversion, 47 ICC_Conversion, 48 ICC_Conversion, 49 ICC_Conversion, 50 ICC_Conversion, 51 ICC_Conversion, 52 ICC_Conversion, 53 ICC_Conversion, 54 ICC_Conversion, 55 ICC_Conversion 56 }; 57 return Category[(int)Kind]; 58} 59 60/// GetConversionRank - Retrieve the implicit conversion rank 61/// corresponding to the given implicit conversion kind. 62ImplicitConversionRank GetConversionRank(ImplicitConversionKind Kind) { 63 static const ImplicitConversionRank 64 Rank[(int)ICK_Num_Conversion_Kinds] = { 65 ICR_Exact_Match, 66 ICR_Exact_Match, 67 ICR_Exact_Match, 68 ICR_Exact_Match, 69 ICR_Exact_Match, 70 ICR_Exact_Match, 71 ICR_Promotion, 72 ICR_Promotion, 73 ICR_Promotion, 74 ICR_Conversion, 75 ICR_Conversion, 76 ICR_Conversion, 77 ICR_Conversion, 78 ICR_Conversion, 79 ICR_Conversion, 80 ICR_Conversion, 81 ICR_Conversion, 82 ICR_Conversion, 83 ICR_Complex_Real_Conversion 84 }; 85 return Rank[(int)Kind]; 86} 87 88/// GetImplicitConversionName - Return the name of this kind of 89/// implicit conversion. 90const char* GetImplicitConversionName(ImplicitConversionKind Kind) { 91 static const char* const Name[(int)ICK_Num_Conversion_Kinds] = { 92 "No conversion", 93 "Lvalue-to-rvalue", 94 "Array-to-pointer", 95 "Function-to-pointer", 96 "Noreturn adjustment", 97 "Qualification", 98 "Integral promotion", 99 "Floating point promotion", 100 "Complex promotion", 101 "Integral conversion", 102 "Floating conversion", 103 "Complex conversion", 104 "Floating-integral conversion", 105 "Complex-real conversion", 106 "Pointer conversion", 107 "Pointer-to-member conversion", 108 "Boolean conversion", 109 "Compatible-types conversion", 110 "Derived-to-base conversion" 111 }; 112 return Name[Kind]; 113} 114 115/// StandardConversionSequence - Set the standard conversion 116/// sequence to the identity conversion. 117void StandardConversionSequence::setAsIdentityConversion() { 118 First = ICK_Identity; 119 Second = ICK_Identity; 120 Third = ICK_Identity; 121 DeprecatedStringLiteralToCharPtr = false; 122 ReferenceBinding = false; 123 DirectBinding = false; 124 RRefBinding = false; 125 CopyConstructor = 0; 126} 127 128/// getRank - Retrieve the rank of this standard conversion sequence 129/// (C++ 13.3.3.1.1p3). The rank is the largest rank of each of the 130/// implicit conversions. 131ImplicitConversionRank StandardConversionSequence::getRank() const { 132 ImplicitConversionRank Rank = ICR_Exact_Match; 133 if (GetConversionRank(First) > Rank) 134 Rank = GetConversionRank(First); 135 if (GetConversionRank(Second) > Rank) 136 Rank = GetConversionRank(Second); 137 if (GetConversionRank(Third) > Rank) 138 Rank = GetConversionRank(Third); 139 return Rank; 140} 141 142/// isPointerConversionToBool - Determines whether this conversion is 143/// a conversion of a pointer or pointer-to-member to bool. This is 144/// used as part of the ranking of standard conversion sequences 145/// (C++ 13.3.3.2p4). 146bool StandardConversionSequence::isPointerConversionToBool() const { 147 // Note that FromType has not necessarily been transformed by the 148 // array-to-pointer or function-to-pointer implicit conversions, so 149 // check for their presence as well as checking whether FromType is 150 // a pointer. 151 if (getToType(1)->isBooleanType() && 152 (getFromType()->isPointerType() || getFromType()->isBlockPointerType() || 153 First == ICK_Array_To_Pointer || First == ICK_Function_To_Pointer)) 154 return true; 155 156 return false; 157} 158 159/// isPointerConversionToVoidPointer - Determines whether this 160/// conversion is a conversion of a pointer to a void pointer. This is 161/// used as part of the ranking of standard conversion sequences (C++ 162/// 13.3.3.2p4). 163bool 164StandardConversionSequence:: 165isPointerConversionToVoidPointer(ASTContext& Context) const { 166 QualType FromType = getFromType(); 167 QualType ToType = getToType(1); 168 169 // Note that FromType has not necessarily been transformed by the 170 // array-to-pointer implicit conversion, so check for its presence 171 // and redo the conversion to get a pointer. 172 if (First == ICK_Array_To_Pointer) 173 FromType = Context.getArrayDecayedType(FromType); 174 175 if (Second == ICK_Pointer_Conversion && FromType->isPointerType()) 176 if (const PointerType* ToPtrType = ToType->getAs<PointerType>()) 177 return ToPtrType->getPointeeType()->isVoidType(); 178 179 return false; 180} 181 182/// DebugPrint - Print this standard conversion sequence to standard 183/// error. Useful for debugging overloading issues. 184void StandardConversionSequence::DebugPrint() const { 185 llvm::raw_ostream &OS = llvm::errs(); 186 bool PrintedSomething = false; 187 if (First != ICK_Identity) { 188 OS << GetImplicitConversionName(First); 189 PrintedSomething = true; 190 } 191 192 if (Second != ICK_Identity) { 193 if (PrintedSomething) { 194 OS << " -> "; 195 } 196 OS << GetImplicitConversionName(Second); 197 198 if (CopyConstructor) { 199 OS << " (by copy constructor)"; 200 } else if (DirectBinding) { 201 OS << " (direct reference binding)"; 202 } else if (ReferenceBinding) { 203 OS << " (reference binding)"; 204 } 205 PrintedSomething = true; 206 } 207 208 if (Third != ICK_Identity) { 209 if (PrintedSomething) { 210 OS << " -> "; 211 } 212 OS << GetImplicitConversionName(Third); 213 PrintedSomething = true; 214 } 215 216 if (!PrintedSomething) { 217 OS << "No conversions required"; 218 } 219} 220 221/// DebugPrint - Print this user-defined conversion sequence to standard 222/// error. Useful for debugging overloading issues. 223void UserDefinedConversionSequence::DebugPrint() const { 224 llvm::raw_ostream &OS = llvm::errs(); 225 if (Before.First || Before.Second || Before.Third) { 226 Before.DebugPrint(); 227 OS << " -> "; 228 } 229 OS << "'" << ConversionFunction->getNameAsString() << "'"; 230 if (After.First || After.Second || After.Third) { 231 OS << " -> "; 232 After.DebugPrint(); 233 } 234} 235 236/// DebugPrint - Print this implicit conversion sequence to standard 237/// error. Useful for debugging overloading issues. 238void ImplicitConversionSequence::DebugPrint() const { 239 llvm::raw_ostream &OS = llvm::errs(); 240 switch (ConversionKind) { 241 case StandardConversion: 242 OS << "Standard conversion: "; 243 Standard.DebugPrint(); 244 break; 245 case UserDefinedConversion: 246 OS << "User-defined conversion: "; 247 UserDefined.DebugPrint(); 248 break; 249 case EllipsisConversion: 250 OS << "Ellipsis conversion"; 251 break; 252 case AmbiguousConversion: 253 OS << "Ambiguous conversion"; 254 break; 255 case BadConversion: 256 OS << "Bad conversion"; 257 break; 258 } 259 260 OS << "\n"; 261} 262 263void AmbiguousConversionSequence::construct() { 264 new (&conversions()) ConversionSet(); 265} 266 267void AmbiguousConversionSequence::destruct() { 268 conversions().~ConversionSet(); 269} 270 271void 272AmbiguousConversionSequence::copyFrom(const AmbiguousConversionSequence &O) { 273 FromTypePtr = O.FromTypePtr; 274 ToTypePtr = O.ToTypePtr; 275 new (&conversions()) ConversionSet(O.conversions()); 276} 277 278 279// IsOverload - Determine whether the given New declaration is an 280// overload of the declarations in Old. This routine returns false if 281// New and Old cannot be overloaded, e.g., if New has the same 282// signature as some function in Old (C++ 1.3.10) or if the Old 283// declarations aren't functions (or function templates) at all. When 284// it does return false, MatchedDecl will point to the decl that New 285// cannot be overloaded with. This decl may be a UsingShadowDecl on 286// top of the underlying declaration. 287// 288// Example: Given the following input: 289// 290// void f(int, float); // #1 291// void f(int, int); // #2 292// int f(int, int); // #3 293// 294// When we process #1, there is no previous declaration of "f", 295// so IsOverload will not be used. 296// 297// When we process #2, Old contains only the FunctionDecl for #1. By 298// comparing the parameter types, we see that #1 and #2 are overloaded 299// (since they have different signatures), so this routine returns 300// false; MatchedDecl is unchanged. 301// 302// When we process #3, Old is an overload set containing #1 and #2. We 303// compare the signatures of #3 to #1 (they're overloaded, so we do 304// nothing) and then #3 to #2. Since the signatures of #3 and #2 are 305// identical (return types of functions are not part of the 306// signature), IsOverload returns false and MatchedDecl will be set to 307// point to the FunctionDecl for #2. 308Sema::OverloadKind 309Sema::CheckOverload(FunctionDecl *New, const LookupResult &Old, 310 NamedDecl *&Match) { 311 for (LookupResult::iterator I = Old.begin(), E = Old.end(); 312 I != E; ++I) { 313 NamedDecl *OldD = (*I)->getUnderlyingDecl(); 314 if (FunctionTemplateDecl *OldT = dyn_cast<FunctionTemplateDecl>(OldD)) { 315 if (!IsOverload(New, OldT->getTemplatedDecl())) { 316 Match = *I; 317 return Ovl_Match; 318 } 319 } else if (FunctionDecl *OldF = dyn_cast<FunctionDecl>(OldD)) { 320 if (!IsOverload(New, OldF)) { 321 Match = *I; 322 return Ovl_Match; 323 } 324 } else if (isa<UsingDecl>(OldD) || isa<TagDecl>(OldD)) { 325 // We can overload with these, which can show up when doing 326 // redeclaration checks for UsingDecls. 327 assert(Old.getLookupKind() == LookupUsingDeclName); 328 } else if (isa<UnresolvedUsingValueDecl>(OldD)) { 329 // Optimistically assume that an unresolved using decl will 330 // overload; if it doesn't, we'll have to diagnose during 331 // template instantiation. 332 } else { 333 // (C++ 13p1): 334 // Only function declarations can be overloaded; object and type 335 // declarations cannot be overloaded. 336 Match = *I; 337 return Ovl_NonFunction; 338 } 339 } 340 341 return Ovl_Overload; 342} 343 344bool Sema::IsOverload(FunctionDecl *New, FunctionDecl *Old) { 345 FunctionTemplateDecl *OldTemplate = Old->getDescribedFunctionTemplate(); 346 FunctionTemplateDecl *NewTemplate = New->getDescribedFunctionTemplate(); 347 348 // C++ [temp.fct]p2: 349 // A function template can be overloaded with other function templates 350 // and with normal (non-template) functions. 351 if ((OldTemplate == 0) != (NewTemplate == 0)) 352 return true; 353 354 // Is the function New an overload of the function Old? 355 QualType OldQType = Context.getCanonicalType(Old->getType()); 356 QualType NewQType = Context.getCanonicalType(New->getType()); 357 358 // Compare the signatures (C++ 1.3.10) of the two functions to 359 // determine whether they are overloads. If we find any mismatch 360 // in the signature, they are overloads. 361 362 // If either of these functions is a K&R-style function (no 363 // prototype), then we consider them to have matching signatures. 364 if (isa<FunctionNoProtoType>(OldQType.getTypePtr()) || 365 isa<FunctionNoProtoType>(NewQType.getTypePtr())) 366 return false; 367 368 FunctionProtoType* OldType = cast<FunctionProtoType>(OldQType); 369 FunctionProtoType* NewType = cast<FunctionProtoType>(NewQType); 370 371 // The signature of a function includes the types of its 372 // parameters (C++ 1.3.10), which includes the presence or absence 373 // of the ellipsis; see C++ DR 357). 374 if (OldQType != NewQType && 375 (OldType->getNumArgs() != NewType->getNumArgs() || 376 OldType->isVariadic() != NewType->isVariadic() || 377 !std::equal(OldType->arg_type_begin(), OldType->arg_type_end(), 378 NewType->arg_type_begin()))) 379 return true; 380 381 // C++ [temp.over.link]p4: 382 // The signature of a function template consists of its function 383 // signature, its return type and its template parameter list. The names 384 // of the template parameters are significant only for establishing the 385 // relationship between the template parameters and the rest of the 386 // signature. 387 // 388 // We check the return type and template parameter lists for function 389 // templates first; the remaining checks follow. 390 if (NewTemplate && 391 (!TemplateParameterListsAreEqual(NewTemplate->getTemplateParameters(), 392 OldTemplate->getTemplateParameters(), 393 false, TPL_TemplateMatch) || 394 OldType->getResultType() != NewType->getResultType())) 395 return true; 396 397 // If the function is a class member, its signature includes the 398 // cv-qualifiers (if any) on the function itself. 399 // 400 // As part of this, also check whether one of the member functions 401 // is static, in which case they are not overloads (C++ 402 // 13.1p2). While not part of the definition of the signature, 403 // this check is important to determine whether these functions 404 // can be overloaded. 405 CXXMethodDecl* OldMethod = dyn_cast<CXXMethodDecl>(Old); 406 CXXMethodDecl* NewMethod = dyn_cast<CXXMethodDecl>(New); 407 if (OldMethod && NewMethod && 408 !OldMethod->isStatic() && !NewMethod->isStatic() && 409 OldMethod->getTypeQualifiers() != NewMethod->getTypeQualifiers()) 410 return true; 411 412 // The signatures match; this is not an overload. 413 return false; 414} 415 416/// TryImplicitConversion - Attempt to perform an implicit conversion 417/// from the given expression (Expr) to the given type (ToType). This 418/// function returns an implicit conversion sequence that can be used 419/// to perform the initialization. Given 420/// 421/// void f(float f); 422/// void g(int i) { f(i); } 423/// 424/// this routine would produce an implicit conversion sequence to 425/// describe the initialization of f from i, which will be a standard 426/// conversion sequence containing an lvalue-to-rvalue conversion (C++ 427/// 4.1) followed by a floating-integral conversion (C++ 4.9). 428// 429/// Note that this routine only determines how the conversion can be 430/// performed; it does not actually perform the conversion. As such, 431/// it will not produce any diagnostics if no conversion is available, 432/// but will instead return an implicit conversion sequence of kind 433/// "BadConversion". 434/// 435/// If @p SuppressUserConversions, then user-defined conversions are 436/// not permitted. 437/// If @p AllowExplicit, then explicit user-defined conversions are 438/// permitted. 439/// If @p UserCast, the implicit conversion is being done for a user-specified 440/// cast. 441ImplicitConversionSequence 442Sema::TryImplicitConversion(Expr* From, QualType ToType, 443 bool SuppressUserConversions, 444 bool AllowExplicit, 445 bool InOverloadResolution, 446 bool UserCast) { 447 ImplicitConversionSequence ICS; 448 if (IsStandardConversion(From, ToType, InOverloadResolution, ICS.Standard)) { 449 ICS.setStandard(); 450 return ICS; 451 } 452 453 if (!getLangOptions().CPlusPlus) { 454 ICS.setBad(BadConversionSequence::no_conversion, From, ToType); 455 return ICS; 456 } 457 458 OverloadCandidateSet Conversions(From->getExprLoc()); 459 OverloadingResult UserDefResult 460 = IsUserDefinedConversion(From, ToType, ICS.UserDefined, Conversions, 461 !SuppressUserConversions, AllowExplicit, 462 UserCast); 463 464 if (UserDefResult == OR_Success) { 465 ICS.setUserDefined(); 466 // C++ [over.ics.user]p4: 467 // A conversion of an expression of class type to the same class 468 // type is given Exact Match rank, and a conversion of an 469 // expression of class type to a base class of that type is 470 // given Conversion rank, in spite of the fact that a copy 471 // constructor (i.e., a user-defined conversion function) is 472 // called for those cases. 473 if (CXXConstructorDecl *Constructor 474 = dyn_cast<CXXConstructorDecl>(ICS.UserDefined.ConversionFunction)) { 475 QualType FromCanon 476 = Context.getCanonicalType(From->getType().getUnqualifiedType()); 477 QualType ToCanon = Context.getCanonicalType(ToType).getUnqualifiedType(); 478 if (Constructor->isCopyConstructor() && 479 (FromCanon == ToCanon || IsDerivedFrom(FromCanon, ToCanon))) { 480 // Turn this into a "standard" conversion sequence, so that it 481 // gets ranked with standard conversion sequences. 482 ICS.setStandard(); 483 ICS.Standard.setAsIdentityConversion(); 484 ICS.Standard.setFromType(From->getType()); 485 ICS.Standard.setAllToTypes(ToType); 486 ICS.Standard.CopyConstructor = Constructor; 487 if (ToCanon != FromCanon) 488 ICS.Standard.Second = ICK_Derived_To_Base; 489 } 490 } 491 492 // C++ [over.best.ics]p4: 493 // However, when considering the argument of a user-defined 494 // conversion function that is a candidate by 13.3.1.3 when 495 // invoked for the copying of the temporary in the second step 496 // of a class copy-initialization, or by 13.3.1.4, 13.3.1.5, or 497 // 13.3.1.6 in all cases, only standard conversion sequences and 498 // ellipsis conversion sequences are allowed. 499 if (SuppressUserConversions && ICS.isUserDefined()) { 500 ICS.setBad(BadConversionSequence::suppressed_user, From, ToType); 501 } 502 } else if (UserDefResult == OR_Ambiguous && !SuppressUserConversions) { 503 ICS.setAmbiguous(); 504 ICS.Ambiguous.setFromType(From->getType()); 505 ICS.Ambiguous.setToType(ToType); 506 for (OverloadCandidateSet::iterator Cand = Conversions.begin(); 507 Cand != Conversions.end(); ++Cand) 508 if (Cand->Viable) 509 ICS.Ambiguous.addConversion(Cand->Function); 510 } else { 511 ICS.setBad(BadConversionSequence::no_conversion, From, ToType); 512 } 513 514 return ICS; 515} 516 517/// \brief Determine whether the conversion from FromType to ToType is a valid 518/// conversion that strips "noreturn" off the nested function type. 519static bool IsNoReturnConversion(ASTContext &Context, QualType FromType, 520 QualType ToType, QualType &ResultTy) { 521 if (Context.hasSameUnqualifiedType(FromType, ToType)) 522 return false; 523 524 // Strip the noreturn off the type we're converting from; noreturn can 525 // safely be removed. 526 FromType = Context.getNoReturnType(FromType, false); 527 if (!Context.hasSameUnqualifiedType(FromType, ToType)) 528 return false; 529 530 ResultTy = FromType; 531 return true; 532} 533 534/// IsStandardConversion - Determines whether there is a standard 535/// conversion sequence (C++ [conv], C++ [over.ics.scs]) from the 536/// expression From to the type ToType. Standard conversion sequences 537/// only consider non-class types; for conversions that involve class 538/// types, use TryImplicitConversion. If a conversion exists, SCS will 539/// contain the standard conversion sequence required to perform this 540/// conversion and this routine will return true. Otherwise, this 541/// routine will return false and the value of SCS is unspecified. 542bool 543Sema::IsStandardConversion(Expr* From, QualType ToType, 544 bool InOverloadResolution, 545 StandardConversionSequence &SCS) { 546 QualType FromType = From->getType(); 547 548 // Standard conversions (C++ [conv]) 549 SCS.setAsIdentityConversion(); 550 SCS.DeprecatedStringLiteralToCharPtr = false; 551 SCS.IncompatibleObjC = false; 552 SCS.setFromType(FromType); 553 SCS.CopyConstructor = 0; 554 555 // There are no standard conversions for class types in C++, so 556 // abort early. When overloading in C, however, we do permit 557 if (FromType->isRecordType() || ToType->isRecordType()) { 558 if (getLangOptions().CPlusPlus) 559 return false; 560 561 // When we're overloading in C, we allow, as standard conversions, 562 } 563 564 // The first conversion can be an lvalue-to-rvalue conversion, 565 // array-to-pointer conversion, or function-to-pointer conversion 566 // (C++ 4p1). 567 568 DeclAccessPair AccessPair; 569 570 // Lvalue-to-rvalue conversion (C++ 4.1): 571 // An lvalue (3.10) of a non-function, non-array type T can be 572 // converted to an rvalue. 573 Expr::isLvalueResult argIsLvalue = From->isLvalue(Context); 574 if (argIsLvalue == Expr::LV_Valid && 575 !FromType->isFunctionType() && !FromType->isArrayType() && 576 Context.getCanonicalType(FromType) != Context.OverloadTy) { 577 SCS.First = ICK_Lvalue_To_Rvalue; 578 579 // If T is a non-class type, the type of the rvalue is the 580 // cv-unqualified version of T. Otherwise, the type of the rvalue 581 // is T (C++ 4.1p1). C++ can't get here with class types; in C, we 582 // just strip the qualifiers because they don't matter. 583 FromType = FromType.getUnqualifiedType(); 584 } else if (FromType->isArrayType()) { 585 // Array-to-pointer conversion (C++ 4.2) 586 SCS.First = ICK_Array_To_Pointer; 587 588 // An lvalue or rvalue of type "array of N T" or "array of unknown 589 // bound of T" can be converted to an rvalue of type "pointer to 590 // T" (C++ 4.2p1). 591 FromType = Context.getArrayDecayedType(FromType); 592 593 if (IsStringLiteralToNonConstPointerConversion(From, ToType)) { 594 // This conversion is deprecated. (C++ D.4). 595 SCS.DeprecatedStringLiteralToCharPtr = true; 596 597 // For the purpose of ranking in overload resolution 598 // (13.3.3.1.1), this conversion is considered an 599 // array-to-pointer conversion followed by a qualification 600 // conversion (4.4). (C++ 4.2p2) 601 SCS.Second = ICK_Identity; 602 SCS.Third = ICK_Qualification; 603 SCS.setAllToTypes(FromType); 604 return true; 605 } 606 } else if (FromType->isFunctionType() && argIsLvalue == Expr::LV_Valid) { 607 // Function-to-pointer conversion (C++ 4.3). 608 SCS.First = ICK_Function_To_Pointer; 609 610 // An lvalue of function type T can be converted to an rvalue of 611 // type "pointer to T." The result is a pointer to the 612 // function. (C++ 4.3p1). 613 FromType = Context.getPointerType(FromType); 614 } else if (From->getType() == Context.OverloadTy) { 615 if (FunctionDecl *Fn 616 = ResolveAddressOfOverloadedFunction(From, ToType, false, 617 AccessPair)) { 618 // Address of overloaded function (C++ [over.over]). 619 SCS.First = ICK_Function_To_Pointer; 620 621 // We were able to resolve the address of the overloaded function, 622 // so we can convert to the type of that function. 623 FromType = Fn->getType(); 624 if (ToType->isLValueReferenceType()) 625 FromType = Context.getLValueReferenceType(FromType); 626 else if (ToType->isRValueReferenceType()) 627 FromType = Context.getRValueReferenceType(FromType); 628 else if (ToType->isMemberPointerType()) { 629 // Resolve address only succeeds if both sides are member pointers, 630 // but it doesn't have to be the same class. See DR 247. 631 // Note that this means that the type of &Derived::fn can be 632 // Ret (Base::*)(Args) if the fn overload actually found is from the 633 // base class, even if it was brought into the derived class via a 634 // using declaration. The standard isn't clear on this issue at all. 635 CXXMethodDecl *M = cast<CXXMethodDecl>(Fn); 636 FromType = Context.getMemberPointerType(FromType, 637 Context.getTypeDeclType(M->getParent()).getTypePtr()); 638 } else { 639 FromType = Context.getPointerType(FromType); 640 } 641 } else { 642 return false; 643 } 644 } else { 645 // We don't require any conversions for the first step. 646 SCS.First = ICK_Identity; 647 } 648 SCS.setToType(0, FromType); 649 650 // The second conversion can be an integral promotion, floating 651 // point promotion, integral conversion, floating point conversion, 652 // floating-integral conversion, pointer conversion, 653 // pointer-to-member conversion, or boolean conversion (C++ 4p1). 654 // For overloading in C, this can also be a "compatible-type" 655 // conversion. 656 bool IncompatibleObjC = false; 657 if (Context.hasSameUnqualifiedType(FromType, ToType)) { 658 // The unqualified versions of the types are the same: there's no 659 // conversion to do. 660 SCS.Second = ICK_Identity; 661 } else if (IsIntegralPromotion(From, FromType, ToType)) { 662 // Integral promotion (C++ 4.5). 663 SCS.Second = ICK_Integral_Promotion; 664 FromType = ToType.getUnqualifiedType(); 665 } else if (IsFloatingPointPromotion(FromType, ToType)) { 666 // Floating point promotion (C++ 4.6). 667 SCS.Second = ICK_Floating_Promotion; 668 FromType = ToType.getUnqualifiedType(); 669 } else if (IsComplexPromotion(FromType, ToType)) { 670 // Complex promotion (Clang extension) 671 SCS.Second = ICK_Complex_Promotion; 672 FromType = ToType.getUnqualifiedType(); 673 } else if ((FromType->isIntegralType() || FromType->isEnumeralType()) && 674 (ToType->isIntegralType() && !ToType->isEnumeralType())) { 675 // Integral conversions (C++ 4.7). 676 SCS.Second = ICK_Integral_Conversion; 677 FromType = ToType.getUnqualifiedType(); 678 } else if (FromType->isComplexType() && ToType->isComplexType()) { 679 // Complex conversions (C99 6.3.1.6) 680 SCS.Second = ICK_Complex_Conversion; 681 FromType = ToType.getUnqualifiedType(); 682 } else if ((FromType->isComplexType() && ToType->isArithmeticType()) || 683 (ToType->isComplexType() && FromType->isArithmeticType())) { 684 // Complex-real conversions (C99 6.3.1.7) 685 SCS.Second = ICK_Complex_Real; 686 FromType = ToType.getUnqualifiedType(); 687 } else if (FromType->isFloatingType() && ToType->isFloatingType()) { 688 // Floating point conversions (C++ 4.8). 689 SCS.Second = ICK_Floating_Conversion; 690 FromType = ToType.getUnqualifiedType(); 691 } else if ((FromType->isFloatingType() && 692 ToType->isIntegralType() && (!ToType->isBooleanType() && 693 !ToType->isEnumeralType())) || 694 ((FromType->isIntegralType() || FromType->isEnumeralType()) && 695 ToType->isFloatingType())) { 696 // Floating-integral conversions (C++ 4.9). 697 SCS.Second = ICK_Floating_Integral; 698 FromType = ToType.getUnqualifiedType(); 699 } else if (IsPointerConversion(From, FromType, ToType, InOverloadResolution, 700 FromType, IncompatibleObjC)) { 701 // Pointer conversions (C++ 4.10). 702 SCS.Second = ICK_Pointer_Conversion; 703 SCS.IncompatibleObjC = IncompatibleObjC; 704 } else if (IsMemberPointerConversion(From, FromType, ToType, 705 InOverloadResolution, FromType)) { 706 // Pointer to member conversions (4.11). 707 SCS.Second = ICK_Pointer_Member; 708 } else if (ToType->isBooleanType() && 709 (FromType->isArithmeticType() || 710 FromType->isEnumeralType() || 711 FromType->isAnyPointerType() || 712 FromType->isBlockPointerType() || 713 FromType->isMemberPointerType() || 714 FromType->isNullPtrType())) { 715 // Boolean conversions (C++ 4.12). 716 SCS.Second = ICK_Boolean_Conversion; 717 FromType = Context.BoolTy; 718 } else if (!getLangOptions().CPlusPlus && 719 Context.typesAreCompatible(ToType, FromType)) { 720 // Compatible conversions (Clang extension for C function overloading) 721 SCS.Second = ICK_Compatible_Conversion; 722 } else if (IsNoReturnConversion(Context, FromType, ToType, FromType)) { 723 // Treat a conversion that strips "noreturn" as an identity conversion. 724 SCS.Second = ICK_NoReturn_Adjustment; 725 } else { 726 // No second conversion required. 727 SCS.Second = ICK_Identity; 728 } 729 SCS.setToType(1, FromType); 730 731 QualType CanonFrom; 732 QualType CanonTo; 733 // The third conversion can be a qualification conversion (C++ 4p1). 734 if (IsQualificationConversion(FromType, ToType)) { 735 SCS.Third = ICK_Qualification; 736 FromType = ToType; 737 CanonFrom = Context.getCanonicalType(FromType); 738 CanonTo = Context.getCanonicalType(ToType); 739 } else { 740 // No conversion required 741 SCS.Third = ICK_Identity; 742 743 // C++ [over.best.ics]p6: 744 // [...] Any difference in top-level cv-qualification is 745 // subsumed by the initialization itself and does not constitute 746 // a conversion. [...] 747 CanonFrom = Context.getCanonicalType(FromType); 748 CanonTo = Context.getCanonicalType(ToType); 749 if (CanonFrom.getLocalUnqualifiedType() 750 == CanonTo.getLocalUnqualifiedType() && 751 CanonFrom.getLocalCVRQualifiers() != CanonTo.getLocalCVRQualifiers()) { 752 FromType = ToType; 753 CanonFrom = CanonTo; 754 } 755 } 756 SCS.setToType(2, FromType); 757 758 // If we have not converted the argument type to the parameter type, 759 // this is a bad conversion sequence. 760 if (CanonFrom != CanonTo) 761 return false; 762 763 return true; 764} 765 766/// IsIntegralPromotion - Determines whether the conversion from the 767/// expression From (whose potentially-adjusted type is FromType) to 768/// ToType is an integral promotion (C++ 4.5). If so, returns true and 769/// sets PromotedType to the promoted type. 770bool Sema::IsIntegralPromotion(Expr *From, QualType FromType, QualType ToType) { 771 const BuiltinType *To = ToType->getAs<BuiltinType>(); 772 // All integers are built-in. 773 if (!To) { 774 return false; 775 } 776 777 // An rvalue of type char, signed char, unsigned char, short int, or 778 // unsigned short int can be converted to an rvalue of type int if 779 // int can represent all the values of the source type; otherwise, 780 // the source rvalue can be converted to an rvalue of type unsigned 781 // int (C++ 4.5p1). 782 if (FromType->isPromotableIntegerType() && !FromType->isBooleanType() && 783 !FromType->isEnumeralType()) { 784 if (// We can promote any signed, promotable integer type to an int 785 (FromType->isSignedIntegerType() || 786 // We can promote any unsigned integer type whose size is 787 // less than int to an int. 788 (!FromType->isSignedIntegerType() && 789 Context.getTypeSize(FromType) < Context.getTypeSize(ToType)))) { 790 return To->getKind() == BuiltinType::Int; 791 } 792 793 return To->getKind() == BuiltinType::UInt; 794 } 795 796 // An rvalue of type wchar_t (3.9.1) or an enumeration type (7.2) 797 // can be converted to an rvalue of the first of the following types 798 // that can represent all the values of its underlying type: int, 799 // unsigned int, long, or unsigned long (C++ 4.5p2). 800 801 // We pre-calculate the promotion type for enum types. 802 if (const EnumType *FromEnumType = FromType->getAs<EnumType>()) 803 if (ToType->isIntegerType()) 804 return Context.hasSameUnqualifiedType(ToType, 805 FromEnumType->getDecl()->getPromotionType()); 806 807 if (FromType->isWideCharType() && ToType->isIntegerType()) { 808 // Determine whether the type we're converting from is signed or 809 // unsigned. 810 bool FromIsSigned; 811 uint64_t FromSize = Context.getTypeSize(FromType); 812 813 // FIXME: Is wchar_t signed or unsigned? We assume it's signed for now. 814 FromIsSigned = true; 815 816 // The types we'll try to promote to, in the appropriate 817 // order. Try each of these types. 818 QualType PromoteTypes[6] = { 819 Context.IntTy, Context.UnsignedIntTy, 820 Context.LongTy, Context.UnsignedLongTy , 821 Context.LongLongTy, Context.UnsignedLongLongTy 822 }; 823 for (int Idx = 0; Idx < 6; ++Idx) { 824 uint64_t ToSize = Context.getTypeSize(PromoteTypes[Idx]); 825 if (FromSize < ToSize || 826 (FromSize == ToSize && 827 FromIsSigned == PromoteTypes[Idx]->isSignedIntegerType())) { 828 // We found the type that we can promote to. If this is the 829 // type we wanted, we have a promotion. Otherwise, no 830 // promotion. 831 return Context.hasSameUnqualifiedType(ToType, PromoteTypes[Idx]); 832 } 833 } 834 } 835 836 // An rvalue for an integral bit-field (9.6) can be converted to an 837 // rvalue of type int if int can represent all the values of the 838 // bit-field; otherwise, it can be converted to unsigned int if 839 // unsigned int can represent all the values of the bit-field. If 840 // the bit-field is larger yet, no integral promotion applies to 841 // it. If the bit-field has an enumerated type, it is treated as any 842 // other value of that type for promotion purposes (C++ 4.5p3). 843 // FIXME: We should delay checking of bit-fields until we actually perform the 844 // conversion. 845 using llvm::APSInt; 846 if (From) 847 if (FieldDecl *MemberDecl = From->getBitField()) { 848 APSInt BitWidth; 849 if (FromType->isIntegralType() && !FromType->isEnumeralType() && 850 MemberDecl->getBitWidth()->isIntegerConstantExpr(BitWidth, Context)) { 851 APSInt ToSize(BitWidth.getBitWidth(), BitWidth.isUnsigned()); 852 ToSize = Context.getTypeSize(ToType); 853 854 // Are we promoting to an int from a bitfield that fits in an int? 855 if (BitWidth < ToSize || 856 (FromType->isSignedIntegerType() && BitWidth <= ToSize)) { 857 return To->getKind() == BuiltinType::Int; 858 } 859 860 // Are we promoting to an unsigned int from an unsigned bitfield 861 // that fits into an unsigned int? 862 if (FromType->isUnsignedIntegerType() && BitWidth <= ToSize) { 863 return To->getKind() == BuiltinType::UInt; 864 } 865 866 return false; 867 } 868 } 869 870 // An rvalue of type bool can be converted to an rvalue of type int, 871 // with false becoming zero and true becoming one (C++ 4.5p4). 872 if (FromType->isBooleanType() && To->getKind() == BuiltinType::Int) { 873 return true; 874 } 875 876 return false; 877} 878 879/// IsFloatingPointPromotion - Determines whether the conversion from 880/// FromType to ToType is a floating point promotion (C++ 4.6). If so, 881/// returns true and sets PromotedType to the promoted type. 882bool Sema::IsFloatingPointPromotion(QualType FromType, QualType ToType) { 883 /// An rvalue of type float can be converted to an rvalue of type 884 /// double. (C++ 4.6p1). 885 if (const BuiltinType *FromBuiltin = FromType->getAs<BuiltinType>()) 886 if (const BuiltinType *ToBuiltin = ToType->getAs<BuiltinType>()) { 887 if (FromBuiltin->getKind() == BuiltinType::Float && 888 ToBuiltin->getKind() == BuiltinType::Double) 889 return true; 890 891 // C99 6.3.1.5p1: 892 // When a float is promoted to double or long double, or a 893 // double is promoted to long double [...]. 894 if (!getLangOptions().CPlusPlus && 895 (FromBuiltin->getKind() == BuiltinType::Float || 896 FromBuiltin->getKind() == BuiltinType::Double) && 897 (ToBuiltin->getKind() == BuiltinType::LongDouble)) 898 return true; 899 } 900 901 return false; 902} 903 904/// \brief Determine if a conversion is a complex promotion. 905/// 906/// A complex promotion is defined as a complex -> complex conversion 907/// where the conversion between the underlying real types is a 908/// floating-point or integral promotion. 909bool Sema::IsComplexPromotion(QualType FromType, QualType ToType) { 910 const ComplexType *FromComplex = FromType->getAs<ComplexType>(); 911 if (!FromComplex) 912 return false; 913 914 const ComplexType *ToComplex = ToType->getAs<ComplexType>(); 915 if (!ToComplex) 916 return false; 917 918 return IsFloatingPointPromotion(FromComplex->getElementType(), 919 ToComplex->getElementType()) || 920 IsIntegralPromotion(0, FromComplex->getElementType(), 921 ToComplex->getElementType()); 922} 923 924/// BuildSimilarlyQualifiedPointerType - In a pointer conversion from 925/// the pointer type FromPtr to a pointer to type ToPointee, with the 926/// same type qualifiers as FromPtr has on its pointee type. ToType, 927/// if non-empty, will be a pointer to ToType that may or may not have 928/// the right set of qualifiers on its pointee. 929static QualType 930BuildSimilarlyQualifiedPointerType(const PointerType *FromPtr, 931 QualType ToPointee, QualType ToType, 932 ASTContext &Context) { 933 QualType CanonFromPointee = Context.getCanonicalType(FromPtr->getPointeeType()); 934 QualType CanonToPointee = Context.getCanonicalType(ToPointee); 935 Qualifiers Quals = CanonFromPointee.getQualifiers(); 936 937 // Exact qualifier match -> return the pointer type we're converting to. 938 if (CanonToPointee.getLocalQualifiers() == Quals) { 939 // ToType is exactly what we need. Return it. 940 if (!ToType.isNull()) 941 return ToType; 942 943 // Build a pointer to ToPointee. It has the right qualifiers 944 // already. 945 return Context.getPointerType(ToPointee); 946 } 947 948 // Just build a canonical type that has the right qualifiers. 949 return Context.getPointerType( 950 Context.getQualifiedType(CanonToPointee.getLocalUnqualifiedType(), 951 Quals)); 952} 953 954/// BuildSimilarlyQualifiedObjCObjectPointerType - In a pointer conversion from 955/// the FromType, which is an objective-c pointer, to ToType, which may or may 956/// not have the right set of qualifiers. 957static QualType 958BuildSimilarlyQualifiedObjCObjectPointerType(QualType FromType, 959 QualType ToType, 960 ASTContext &Context) { 961 QualType CanonFromType = Context.getCanonicalType(FromType); 962 QualType CanonToType = Context.getCanonicalType(ToType); 963 Qualifiers Quals = CanonFromType.getQualifiers(); 964 965 // Exact qualifier match -> return the pointer type we're converting to. 966 if (CanonToType.getLocalQualifiers() == Quals) 967 return ToType; 968 969 // Just build a canonical type that has the right qualifiers. 970 return Context.getQualifiedType(CanonToType.getLocalUnqualifiedType(), Quals); 971} 972 973static bool isNullPointerConstantForConversion(Expr *Expr, 974 bool InOverloadResolution, 975 ASTContext &Context) { 976 // Handle value-dependent integral null pointer constants correctly. 977 // http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#903 978 if (Expr->isValueDependent() && !Expr->isTypeDependent() && 979 Expr->getType()->isIntegralType()) 980 return !InOverloadResolution; 981 982 return Expr->isNullPointerConstant(Context, 983 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull 984 : Expr::NPC_ValueDependentIsNull); 985} 986 987/// IsPointerConversion - Determines whether the conversion of the 988/// expression From, which has the (possibly adjusted) type FromType, 989/// can be converted to the type ToType via a pointer conversion (C++ 990/// 4.10). If so, returns true and places the converted type (that 991/// might differ from ToType in its cv-qualifiers at some level) into 992/// ConvertedType. 993/// 994/// This routine also supports conversions to and from block pointers 995/// and conversions with Objective-C's 'id', 'id<protocols...>', and 996/// pointers to interfaces. FIXME: Once we've determined the 997/// appropriate overloading rules for Objective-C, we may want to 998/// split the Objective-C checks into a different routine; however, 999/// GCC seems to consider all of these conversions to be pointer 1000/// conversions, so for now they live here. IncompatibleObjC will be 1001/// set if the conversion is an allowed Objective-C conversion that 1002/// should result in a warning. 1003bool Sema::IsPointerConversion(Expr *From, QualType FromType, QualType ToType, 1004 bool InOverloadResolution, 1005 QualType& ConvertedType, 1006 bool &IncompatibleObjC) { 1007 IncompatibleObjC = false; 1008 if (isObjCPointerConversion(FromType, ToType, ConvertedType, IncompatibleObjC)) 1009 return true; 1010 1011 // Conversion from a null pointer constant to any Objective-C pointer type. 1012 if (ToType->isObjCObjectPointerType() && 1013 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1014 ConvertedType = ToType; 1015 return true; 1016 } 1017 1018 // Blocks: Block pointers can be converted to void*. 1019 if (FromType->isBlockPointerType() && ToType->isPointerType() && 1020 ToType->getAs<PointerType>()->getPointeeType()->isVoidType()) { 1021 ConvertedType = ToType; 1022 return true; 1023 } 1024 // Blocks: A null pointer constant can be converted to a block 1025 // pointer type. 1026 if (ToType->isBlockPointerType() && 1027 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1028 ConvertedType = ToType; 1029 return true; 1030 } 1031 1032 // If the left-hand-side is nullptr_t, the right side can be a null 1033 // pointer constant. 1034 if (ToType->isNullPtrType() && 1035 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1036 ConvertedType = ToType; 1037 return true; 1038 } 1039 1040 const PointerType* ToTypePtr = ToType->getAs<PointerType>(); 1041 if (!ToTypePtr) 1042 return false; 1043 1044 // A null pointer constant can be converted to a pointer type (C++ 4.10p1). 1045 if (isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1046 ConvertedType = ToType; 1047 return true; 1048 } 1049 1050 // Beyond this point, both types need to be pointers 1051 // , including objective-c pointers. 1052 QualType ToPointeeType = ToTypePtr->getPointeeType(); 1053 if (FromType->isObjCObjectPointerType() && ToPointeeType->isVoidType()) { 1054 ConvertedType = BuildSimilarlyQualifiedObjCObjectPointerType(FromType, 1055 ToType, Context); 1056 return true; 1057 1058 } 1059 const PointerType *FromTypePtr = FromType->getAs<PointerType>(); 1060 if (!FromTypePtr) 1061 return false; 1062 1063 QualType FromPointeeType = FromTypePtr->getPointeeType(); 1064 1065 // An rvalue of type "pointer to cv T," where T is an object type, 1066 // can be converted to an rvalue of type "pointer to cv void" (C++ 1067 // 4.10p2). 1068 if (FromPointeeType->isObjectType() && ToPointeeType->isVoidType()) { 1069 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1070 ToPointeeType, 1071 ToType, Context); 1072 return true; 1073 } 1074 1075 // When we're overloading in C, we allow a special kind of pointer 1076 // conversion for compatible-but-not-identical pointee types. 1077 if (!getLangOptions().CPlusPlus && 1078 Context.typesAreCompatible(FromPointeeType, ToPointeeType)) { 1079 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1080 ToPointeeType, 1081 ToType, Context); 1082 return true; 1083 } 1084 1085 // C++ [conv.ptr]p3: 1086 // 1087 // An rvalue of type "pointer to cv D," where D is a class type, 1088 // can be converted to an rvalue of type "pointer to cv B," where 1089 // B is a base class (clause 10) of D. If B is an inaccessible 1090 // (clause 11) or ambiguous (10.2) base class of D, a program that 1091 // necessitates this conversion is ill-formed. The result of the 1092 // conversion is a pointer to the base class sub-object of the 1093 // derived class object. The null pointer value is converted to 1094 // the null pointer value of the destination type. 1095 // 1096 // Note that we do not check for ambiguity or inaccessibility 1097 // here. That is handled by CheckPointerConversion. 1098 if (getLangOptions().CPlusPlus && 1099 FromPointeeType->isRecordType() && ToPointeeType->isRecordType() && 1100 !Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType) && 1101 !RequireCompleteType(From->getLocStart(), FromPointeeType, PDiag()) && 1102 IsDerivedFrom(FromPointeeType, ToPointeeType)) { 1103 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1104 ToPointeeType, 1105 ToType, Context); 1106 return true; 1107 } 1108 1109 return false; 1110} 1111 1112/// isObjCPointerConversion - Determines whether this is an 1113/// Objective-C pointer conversion. Subroutine of IsPointerConversion, 1114/// with the same arguments and return values. 1115bool Sema::isObjCPointerConversion(QualType FromType, QualType ToType, 1116 QualType& ConvertedType, 1117 bool &IncompatibleObjC) { 1118 if (!getLangOptions().ObjC1) 1119 return false; 1120 1121 // First, we handle all conversions on ObjC object pointer types. 1122 const ObjCObjectPointerType* ToObjCPtr = ToType->getAs<ObjCObjectPointerType>(); 1123 const ObjCObjectPointerType *FromObjCPtr = 1124 FromType->getAs<ObjCObjectPointerType>(); 1125 1126 if (ToObjCPtr && FromObjCPtr) { 1127 // Objective C++: We're able to convert between "id" or "Class" and a 1128 // pointer to any interface (in both directions). 1129 if (ToObjCPtr->isObjCBuiltinType() && FromObjCPtr->isObjCBuiltinType()) { 1130 ConvertedType = ToType; 1131 return true; 1132 } 1133 // Conversions with Objective-C's id<...>. 1134 if ((FromObjCPtr->isObjCQualifiedIdType() || 1135 ToObjCPtr->isObjCQualifiedIdType()) && 1136 Context.ObjCQualifiedIdTypesAreCompatible(ToType, FromType, 1137 /*compare=*/false)) { 1138 ConvertedType = ToType; 1139 return true; 1140 } 1141 // Objective C++: We're able to convert from a pointer to an 1142 // interface to a pointer to a different interface. 1143 if (Context.canAssignObjCInterfaces(ToObjCPtr, FromObjCPtr)) { 1144 const ObjCInterfaceType* LHS = ToObjCPtr->getInterfaceType(); 1145 const ObjCInterfaceType* RHS = FromObjCPtr->getInterfaceType(); 1146 if (getLangOptions().CPlusPlus && LHS && RHS && 1147 !ToObjCPtr->getPointeeType().isAtLeastAsQualifiedAs( 1148 FromObjCPtr->getPointeeType())) 1149 return false; 1150 ConvertedType = ToType; 1151 return true; 1152 } 1153 1154 if (Context.canAssignObjCInterfaces(FromObjCPtr, ToObjCPtr)) { 1155 // Okay: this is some kind of implicit downcast of Objective-C 1156 // interfaces, which is permitted. However, we're going to 1157 // complain about it. 1158 IncompatibleObjC = true; 1159 ConvertedType = FromType; 1160 return true; 1161 } 1162 } 1163 // Beyond this point, both types need to be C pointers or block pointers. 1164 QualType ToPointeeType; 1165 if (const PointerType *ToCPtr = ToType->getAs<PointerType>()) 1166 ToPointeeType = ToCPtr->getPointeeType(); 1167 else if (const BlockPointerType *ToBlockPtr = 1168 ToType->getAs<BlockPointerType>()) { 1169 // Objective C++: We're able to convert from a pointer to any object 1170 // to a block pointer type. 1171 if (FromObjCPtr && FromObjCPtr->isObjCBuiltinType()) { 1172 ConvertedType = ToType; 1173 return true; 1174 } 1175 ToPointeeType = ToBlockPtr->getPointeeType(); 1176 } 1177 else if (FromType->getAs<BlockPointerType>() && 1178 ToObjCPtr && ToObjCPtr->isObjCBuiltinType()) { 1179 // Objective C++: We're able to convert from a block pointer type to a 1180 // pointer to any object. 1181 ConvertedType = ToType; 1182 return true; 1183 } 1184 else 1185 return false; 1186 1187 QualType FromPointeeType; 1188 if (const PointerType *FromCPtr = FromType->getAs<PointerType>()) 1189 FromPointeeType = FromCPtr->getPointeeType(); 1190 else if (const BlockPointerType *FromBlockPtr = FromType->getAs<BlockPointerType>()) 1191 FromPointeeType = FromBlockPtr->getPointeeType(); 1192 else 1193 return false; 1194 1195 // If we have pointers to pointers, recursively check whether this 1196 // is an Objective-C conversion. 1197 if (FromPointeeType->isPointerType() && ToPointeeType->isPointerType() && 1198 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, 1199 IncompatibleObjC)) { 1200 // We always complain about this conversion. 1201 IncompatibleObjC = true; 1202 ConvertedType = ToType; 1203 return true; 1204 } 1205 // Allow conversion of pointee being objective-c pointer to another one; 1206 // as in I* to id. 1207 if (FromPointeeType->getAs<ObjCObjectPointerType>() && 1208 ToPointeeType->getAs<ObjCObjectPointerType>() && 1209 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, 1210 IncompatibleObjC)) { 1211 ConvertedType = ToType; 1212 return true; 1213 } 1214 1215 // If we have pointers to functions or blocks, check whether the only 1216 // differences in the argument and result types are in Objective-C 1217 // pointer conversions. If so, we permit the conversion (but 1218 // complain about it). 1219 const FunctionProtoType *FromFunctionType 1220 = FromPointeeType->getAs<FunctionProtoType>(); 1221 const FunctionProtoType *ToFunctionType 1222 = ToPointeeType->getAs<FunctionProtoType>(); 1223 if (FromFunctionType && ToFunctionType) { 1224 // If the function types are exactly the same, this isn't an 1225 // Objective-C pointer conversion. 1226 if (Context.getCanonicalType(FromPointeeType) 1227 == Context.getCanonicalType(ToPointeeType)) 1228 return false; 1229 1230 // Perform the quick checks that will tell us whether these 1231 // function types are obviously different. 1232 if (FromFunctionType->getNumArgs() != ToFunctionType->getNumArgs() || 1233 FromFunctionType->isVariadic() != ToFunctionType->isVariadic() || 1234 FromFunctionType->getTypeQuals() != ToFunctionType->getTypeQuals()) 1235 return false; 1236 1237 bool HasObjCConversion = false; 1238 if (Context.getCanonicalType(FromFunctionType->getResultType()) 1239 == Context.getCanonicalType(ToFunctionType->getResultType())) { 1240 // Okay, the types match exactly. Nothing to do. 1241 } else if (isObjCPointerConversion(FromFunctionType->getResultType(), 1242 ToFunctionType->getResultType(), 1243 ConvertedType, IncompatibleObjC)) { 1244 // Okay, we have an Objective-C pointer conversion. 1245 HasObjCConversion = true; 1246 } else { 1247 // Function types are too different. Abort. 1248 return false; 1249 } 1250 1251 // Check argument types. 1252 for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumArgs(); 1253 ArgIdx != NumArgs; ++ArgIdx) { 1254 QualType FromArgType = FromFunctionType->getArgType(ArgIdx); 1255 QualType ToArgType = ToFunctionType->getArgType(ArgIdx); 1256 if (Context.getCanonicalType(FromArgType) 1257 == Context.getCanonicalType(ToArgType)) { 1258 // Okay, the types match exactly. Nothing to do. 1259 } else if (isObjCPointerConversion(FromArgType, ToArgType, 1260 ConvertedType, IncompatibleObjC)) { 1261 // Okay, we have an Objective-C pointer conversion. 1262 HasObjCConversion = true; 1263 } else { 1264 // Argument types are too different. Abort. 1265 return false; 1266 } 1267 } 1268 1269 if (HasObjCConversion) { 1270 // We had an Objective-C conversion. Allow this pointer 1271 // conversion, but complain about it. 1272 ConvertedType = ToType; 1273 IncompatibleObjC = true; 1274 return true; 1275 } 1276 } 1277 1278 return false; 1279} 1280 1281/// CheckPointerConversion - Check the pointer conversion from the 1282/// expression From to the type ToType. This routine checks for 1283/// ambiguous or inaccessible derived-to-base pointer 1284/// conversions for which IsPointerConversion has already returned 1285/// true. It returns true and produces a diagnostic if there was an 1286/// error, or returns false otherwise. 1287bool Sema::CheckPointerConversion(Expr *From, QualType ToType, 1288 CastExpr::CastKind &Kind, 1289 bool IgnoreBaseAccess) { 1290 QualType FromType = From->getType(); 1291 1292 if (const PointerType *FromPtrType = FromType->getAs<PointerType>()) 1293 if (const PointerType *ToPtrType = ToType->getAs<PointerType>()) { 1294 QualType FromPointeeType = FromPtrType->getPointeeType(), 1295 ToPointeeType = ToPtrType->getPointeeType(); 1296 1297 if (FromPointeeType->isRecordType() && ToPointeeType->isRecordType() && 1298 !Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType)) { 1299 // We must have a derived-to-base conversion. Check an 1300 // ambiguous or inaccessible conversion. 1301 if (CheckDerivedToBaseConversion(FromPointeeType, ToPointeeType, 1302 From->getExprLoc(), 1303 From->getSourceRange(), 1304 IgnoreBaseAccess)) 1305 return true; 1306 1307 // The conversion was successful. 1308 Kind = CastExpr::CK_DerivedToBase; 1309 } 1310 } 1311 if (const ObjCObjectPointerType *FromPtrType = 1312 FromType->getAs<ObjCObjectPointerType>()) 1313 if (const ObjCObjectPointerType *ToPtrType = 1314 ToType->getAs<ObjCObjectPointerType>()) { 1315 // Objective-C++ conversions are always okay. 1316 // FIXME: We should have a different class of conversions for the 1317 // Objective-C++ implicit conversions. 1318 if (FromPtrType->isObjCBuiltinType() || ToPtrType->isObjCBuiltinType()) 1319 return false; 1320 1321 } 1322 return false; 1323} 1324 1325/// IsMemberPointerConversion - Determines whether the conversion of the 1326/// expression From, which has the (possibly adjusted) type FromType, can be 1327/// converted to the type ToType via a member pointer conversion (C++ 4.11). 1328/// If so, returns true and places the converted type (that might differ from 1329/// ToType in its cv-qualifiers at some level) into ConvertedType. 1330bool Sema::IsMemberPointerConversion(Expr *From, QualType FromType, 1331 QualType ToType, 1332 bool InOverloadResolution, 1333 QualType &ConvertedType) { 1334 const MemberPointerType *ToTypePtr = ToType->getAs<MemberPointerType>(); 1335 if (!ToTypePtr) 1336 return false; 1337 1338 // A null pointer constant can be converted to a member pointer (C++ 4.11p1) 1339 if (From->isNullPointerConstant(Context, 1340 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull 1341 : Expr::NPC_ValueDependentIsNull)) { 1342 ConvertedType = ToType; 1343 return true; 1344 } 1345 1346 // Otherwise, both types have to be member pointers. 1347 const MemberPointerType *FromTypePtr = FromType->getAs<MemberPointerType>(); 1348 if (!FromTypePtr) 1349 return false; 1350 1351 // A pointer to member of B can be converted to a pointer to member of D, 1352 // where D is derived from B (C++ 4.11p2). 1353 QualType FromClass(FromTypePtr->getClass(), 0); 1354 QualType ToClass(ToTypePtr->getClass(), 0); 1355 // FIXME: What happens when these are dependent? Is this function even called? 1356 1357 if (IsDerivedFrom(ToClass, FromClass)) { 1358 ConvertedType = Context.getMemberPointerType(FromTypePtr->getPointeeType(), 1359 ToClass.getTypePtr()); 1360 return true; 1361 } 1362 1363 return false; 1364} 1365 1366/// CheckMemberPointerConversion - Check the member pointer conversion from the 1367/// expression From to the type ToType. This routine checks for ambiguous or 1368/// virtual or inaccessible base-to-derived member pointer conversions 1369/// for which IsMemberPointerConversion has already returned true. It returns 1370/// true and produces a diagnostic if there was an error, or returns false 1371/// otherwise. 1372bool Sema::CheckMemberPointerConversion(Expr *From, QualType ToType, 1373 CastExpr::CastKind &Kind, 1374 bool IgnoreBaseAccess) { 1375 QualType FromType = From->getType(); 1376 const MemberPointerType *FromPtrType = FromType->getAs<MemberPointerType>(); 1377 if (!FromPtrType) { 1378 // This must be a null pointer to member pointer conversion 1379 assert(From->isNullPointerConstant(Context, 1380 Expr::NPC_ValueDependentIsNull) && 1381 "Expr must be null pointer constant!"); 1382 Kind = CastExpr::CK_NullToMemberPointer; 1383 return false; 1384 } 1385 1386 const MemberPointerType *ToPtrType = ToType->getAs<MemberPointerType>(); 1387 assert(ToPtrType && "No member pointer cast has a target type " 1388 "that is not a member pointer."); 1389 1390 QualType FromClass = QualType(FromPtrType->getClass(), 0); 1391 QualType ToClass = QualType(ToPtrType->getClass(), 0); 1392 1393 // FIXME: What about dependent types? 1394 assert(FromClass->isRecordType() && "Pointer into non-class."); 1395 assert(ToClass->isRecordType() && "Pointer into non-class."); 1396 1397 CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/ true, 1398 /*DetectVirtual=*/true); 1399 bool DerivationOkay = IsDerivedFrom(ToClass, FromClass, Paths); 1400 assert(DerivationOkay && 1401 "Should not have been called if derivation isn't OK."); 1402 (void)DerivationOkay; 1403 1404 if (Paths.isAmbiguous(Context.getCanonicalType(FromClass). 1405 getUnqualifiedType())) { 1406 std::string PathDisplayStr = getAmbiguousPathsDisplayString(Paths); 1407 Diag(From->getExprLoc(), diag::err_ambiguous_memptr_conv) 1408 << 0 << FromClass << ToClass << PathDisplayStr << From->getSourceRange(); 1409 return true; 1410 } 1411 1412 if (const RecordType *VBase = Paths.getDetectedVirtual()) { 1413 Diag(From->getExprLoc(), diag::err_memptr_conv_via_virtual) 1414 << FromClass << ToClass << QualType(VBase, 0) 1415 << From->getSourceRange(); 1416 return true; 1417 } 1418 1419 if (!IgnoreBaseAccess) 1420 CheckBaseClassAccess(From->getExprLoc(), FromClass, ToClass, 1421 Paths.front(), 1422 diag::err_downcast_from_inaccessible_base); 1423 1424 // Must be a base to derived member conversion. 1425 Kind = CastExpr::CK_BaseToDerivedMemberPointer; 1426 return false; 1427} 1428 1429/// IsQualificationConversion - Determines whether the conversion from 1430/// an rvalue of type FromType to ToType is a qualification conversion 1431/// (C++ 4.4). 1432bool 1433Sema::IsQualificationConversion(QualType FromType, QualType ToType) { 1434 FromType = Context.getCanonicalType(FromType); 1435 ToType = Context.getCanonicalType(ToType); 1436 1437 // If FromType and ToType are the same type, this is not a 1438 // qualification conversion. 1439 if (FromType.getUnqualifiedType() == ToType.getUnqualifiedType()) 1440 return false; 1441 1442 // (C++ 4.4p4): 1443 // A conversion can add cv-qualifiers at levels other than the first 1444 // in multi-level pointers, subject to the following rules: [...] 1445 bool PreviousToQualsIncludeConst = true; 1446 bool UnwrappedAnyPointer = false; 1447 while (UnwrapSimilarPointerTypes(FromType, ToType)) { 1448 // Within each iteration of the loop, we check the qualifiers to 1449 // determine if this still looks like a qualification 1450 // conversion. Then, if all is well, we unwrap one more level of 1451 // pointers or pointers-to-members and do it all again 1452 // until there are no more pointers or pointers-to-members left to 1453 // unwrap. 1454 UnwrappedAnyPointer = true; 1455 1456 // -- for every j > 0, if const is in cv 1,j then const is in cv 1457 // 2,j, and similarly for volatile. 1458 if (!ToType.isAtLeastAsQualifiedAs(FromType)) 1459 return false; 1460 1461 // -- if the cv 1,j and cv 2,j are different, then const is in 1462 // every cv for 0 < k < j. 1463 if (FromType.getCVRQualifiers() != ToType.getCVRQualifiers() 1464 && !PreviousToQualsIncludeConst) 1465 return false; 1466 1467 // Keep track of whether all prior cv-qualifiers in the "to" type 1468 // include const. 1469 PreviousToQualsIncludeConst 1470 = PreviousToQualsIncludeConst && ToType.isConstQualified(); 1471 } 1472 1473 // We are left with FromType and ToType being the pointee types 1474 // after unwrapping the original FromType and ToType the same number 1475 // of types. If we unwrapped any pointers, and if FromType and 1476 // ToType have the same unqualified type (since we checked 1477 // qualifiers above), then this is a qualification conversion. 1478 return UnwrappedAnyPointer && Context.hasSameUnqualifiedType(FromType,ToType); 1479} 1480 1481/// Determines whether there is a user-defined conversion sequence 1482/// (C++ [over.ics.user]) that converts expression From to the type 1483/// ToType. If such a conversion exists, User will contain the 1484/// user-defined conversion sequence that performs such a conversion 1485/// and this routine will return true. Otherwise, this routine returns 1486/// false and User is unspecified. 1487/// 1488/// \param AllowConversionFunctions true if the conversion should 1489/// consider conversion functions at all. If false, only constructors 1490/// will be considered. 1491/// 1492/// \param AllowExplicit true if the conversion should consider C++0x 1493/// "explicit" conversion functions as well as non-explicit conversion 1494/// functions (C++0x [class.conv.fct]p2). 1495/// 1496/// \param UserCast true if looking for user defined conversion for a static 1497/// cast. 1498OverloadingResult Sema::IsUserDefinedConversion(Expr *From, QualType ToType, 1499 UserDefinedConversionSequence& User, 1500 OverloadCandidateSet& CandidateSet, 1501 bool AllowConversionFunctions, 1502 bool AllowExplicit, 1503 bool UserCast) { 1504 if (const RecordType *ToRecordType = ToType->getAs<RecordType>()) { 1505 if (RequireCompleteType(From->getLocStart(), ToType, PDiag())) { 1506 // We're not going to find any constructors. 1507 } else if (CXXRecordDecl *ToRecordDecl 1508 = dyn_cast<CXXRecordDecl>(ToRecordType->getDecl())) { 1509 // C++ [over.match.ctor]p1: 1510 // When objects of class type are direct-initialized (8.5), or 1511 // copy-initialized from an expression of the same or a 1512 // derived class type (8.5), overload resolution selects the 1513 // constructor. [...] For copy-initialization, the candidate 1514 // functions are all the converting constructors (12.3.1) of 1515 // that class. The argument list is the expression-list within 1516 // the parentheses of the initializer. 1517 bool SuppressUserConversions = !UserCast; 1518 if (Context.hasSameUnqualifiedType(ToType, From->getType()) || 1519 IsDerivedFrom(From->getType(), ToType)) { 1520 SuppressUserConversions = false; 1521 AllowConversionFunctions = false; 1522 } 1523 1524 DeclarationName ConstructorName 1525 = Context.DeclarationNames.getCXXConstructorName( 1526 Context.getCanonicalType(ToType).getUnqualifiedType()); 1527 DeclContext::lookup_iterator Con, ConEnd; 1528 for (llvm::tie(Con, ConEnd) 1529 = ToRecordDecl->lookup(ConstructorName); 1530 Con != ConEnd; ++Con) { 1531 NamedDecl *D = *Con; 1532 DeclAccessPair FoundDecl = DeclAccessPair::make(D, D->getAccess()); 1533 1534 // Find the constructor (which may be a template). 1535 CXXConstructorDecl *Constructor = 0; 1536 FunctionTemplateDecl *ConstructorTmpl 1537 = dyn_cast<FunctionTemplateDecl>(D); 1538 if (ConstructorTmpl) 1539 Constructor 1540 = cast<CXXConstructorDecl>(ConstructorTmpl->getTemplatedDecl()); 1541 else 1542 Constructor = cast<CXXConstructorDecl>(D); 1543 1544 if (!Constructor->isInvalidDecl() && 1545 Constructor->isConvertingConstructor(AllowExplicit)) { 1546 if (ConstructorTmpl) 1547 AddTemplateOverloadCandidate(ConstructorTmpl, FoundDecl, 1548 /*ExplicitArgs*/ 0, 1549 &From, 1, CandidateSet, 1550 SuppressUserConversions); 1551 else 1552 // Allow one user-defined conversion when user specifies a 1553 // From->ToType conversion via an static cast (c-style, etc). 1554 AddOverloadCandidate(Constructor, FoundDecl, 1555 &From, 1, CandidateSet, 1556 SuppressUserConversions); 1557 } 1558 } 1559 } 1560 } 1561 1562 if (!AllowConversionFunctions) { 1563 // Don't allow any conversion functions to enter the overload set. 1564 } else if (RequireCompleteType(From->getLocStart(), From->getType(), 1565 PDiag(0) 1566 << From->getSourceRange())) { 1567 // No conversion functions from incomplete types. 1568 } else if (const RecordType *FromRecordType 1569 = From->getType()->getAs<RecordType>()) { 1570 if (CXXRecordDecl *FromRecordDecl 1571 = dyn_cast<CXXRecordDecl>(FromRecordType->getDecl())) { 1572 // Add all of the conversion functions as candidates. 1573 const UnresolvedSetImpl *Conversions 1574 = FromRecordDecl->getVisibleConversionFunctions(); 1575 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 1576 E = Conversions->end(); I != E; ++I) { 1577 DeclAccessPair FoundDecl = I.getPair(); 1578 NamedDecl *D = FoundDecl.getDecl(); 1579 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext()); 1580 if (isa<UsingShadowDecl>(D)) 1581 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 1582 1583 CXXConversionDecl *Conv; 1584 FunctionTemplateDecl *ConvTemplate; 1585 if ((ConvTemplate = dyn_cast<FunctionTemplateDecl>(D))) 1586 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 1587 else 1588 Conv = cast<CXXConversionDecl>(D); 1589 1590 if (AllowExplicit || !Conv->isExplicit()) { 1591 if (ConvTemplate) 1592 AddTemplateConversionCandidate(ConvTemplate, FoundDecl, 1593 ActingContext, From, ToType, 1594 CandidateSet); 1595 else 1596 AddConversionCandidate(Conv, FoundDecl, ActingContext, 1597 From, ToType, CandidateSet); 1598 } 1599 } 1600 } 1601 } 1602 1603 OverloadCandidateSet::iterator Best; 1604 switch (BestViableFunction(CandidateSet, From->getLocStart(), Best)) { 1605 case OR_Success: 1606 // Record the standard conversion we used and the conversion function. 1607 if (CXXConstructorDecl *Constructor 1608 = dyn_cast<CXXConstructorDecl>(Best->Function)) { 1609 // C++ [over.ics.user]p1: 1610 // If the user-defined conversion is specified by a 1611 // constructor (12.3.1), the initial standard conversion 1612 // sequence converts the source type to the type required by 1613 // the argument of the constructor. 1614 // 1615 QualType ThisType = Constructor->getThisType(Context); 1616 if (Best->Conversions[0].isEllipsis()) 1617 User.EllipsisConversion = true; 1618 else { 1619 User.Before = Best->Conversions[0].Standard; 1620 User.EllipsisConversion = false; 1621 } 1622 User.ConversionFunction = Constructor; 1623 User.After.setAsIdentityConversion(); 1624 User.After.setFromType( 1625 ThisType->getAs<PointerType>()->getPointeeType()); 1626 User.After.setAllToTypes(ToType); 1627 return OR_Success; 1628 } else if (CXXConversionDecl *Conversion 1629 = dyn_cast<CXXConversionDecl>(Best->Function)) { 1630 // C++ [over.ics.user]p1: 1631 // 1632 // [...] If the user-defined conversion is specified by a 1633 // conversion function (12.3.2), the initial standard 1634 // conversion sequence converts the source type to the 1635 // implicit object parameter of the conversion function. 1636 User.Before = Best->Conversions[0].Standard; 1637 User.ConversionFunction = Conversion; 1638 User.EllipsisConversion = false; 1639 1640 // C++ [over.ics.user]p2: 1641 // The second standard conversion sequence converts the 1642 // result of the user-defined conversion to the target type 1643 // for the sequence. Since an implicit conversion sequence 1644 // is an initialization, the special rules for 1645 // initialization by user-defined conversion apply when 1646 // selecting the best user-defined conversion for a 1647 // user-defined conversion sequence (see 13.3.3 and 1648 // 13.3.3.1). 1649 User.After = Best->FinalConversion; 1650 return OR_Success; 1651 } else { 1652 assert(false && "Not a constructor or conversion function?"); 1653 return OR_No_Viable_Function; 1654 } 1655 1656 case OR_No_Viable_Function: 1657 return OR_No_Viable_Function; 1658 case OR_Deleted: 1659 // No conversion here! We're done. 1660 return OR_Deleted; 1661 1662 case OR_Ambiguous: 1663 return OR_Ambiguous; 1664 } 1665 1666 return OR_No_Viable_Function; 1667} 1668 1669bool 1670Sema::DiagnoseMultipleUserDefinedConversion(Expr *From, QualType ToType) { 1671 ImplicitConversionSequence ICS; 1672 OverloadCandidateSet CandidateSet(From->getExprLoc()); 1673 OverloadingResult OvResult = 1674 IsUserDefinedConversion(From, ToType, ICS.UserDefined, 1675 CandidateSet, true, false, false); 1676 if (OvResult == OR_Ambiguous) 1677 Diag(From->getSourceRange().getBegin(), 1678 diag::err_typecheck_ambiguous_condition) 1679 << From->getType() << ToType << From->getSourceRange(); 1680 else if (OvResult == OR_No_Viable_Function && !CandidateSet.empty()) 1681 Diag(From->getSourceRange().getBegin(), 1682 diag::err_typecheck_nonviable_condition) 1683 << From->getType() << ToType << From->getSourceRange(); 1684 else 1685 return false; 1686 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, &From, 1); 1687 return true; 1688} 1689 1690/// CompareImplicitConversionSequences - Compare two implicit 1691/// conversion sequences to determine whether one is better than the 1692/// other or if they are indistinguishable (C++ 13.3.3.2). 1693ImplicitConversionSequence::CompareKind 1694Sema::CompareImplicitConversionSequences(const ImplicitConversionSequence& ICS1, 1695 const ImplicitConversionSequence& ICS2) 1696{ 1697 // (C++ 13.3.3.2p2): When comparing the basic forms of implicit 1698 // conversion sequences (as defined in 13.3.3.1) 1699 // -- a standard conversion sequence (13.3.3.1.1) is a better 1700 // conversion sequence than a user-defined conversion sequence or 1701 // an ellipsis conversion sequence, and 1702 // -- a user-defined conversion sequence (13.3.3.1.2) is a better 1703 // conversion sequence than an ellipsis conversion sequence 1704 // (13.3.3.1.3). 1705 // 1706 // C++0x [over.best.ics]p10: 1707 // For the purpose of ranking implicit conversion sequences as 1708 // described in 13.3.3.2, the ambiguous conversion sequence is 1709 // treated as a user-defined sequence that is indistinguishable 1710 // from any other user-defined conversion sequence. 1711 if (ICS1.getKind() < ICS2.getKind()) { 1712 if (!(ICS1.isUserDefined() && ICS2.isAmbiguous())) 1713 return ImplicitConversionSequence::Better; 1714 } else if (ICS2.getKind() < ICS1.getKind()) { 1715 if (!(ICS2.isUserDefined() && ICS1.isAmbiguous())) 1716 return ImplicitConversionSequence::Worse; 1717 } 1718 1719 if (ICS1.isAmbiguous() || ICS2.isAmbiguous()) 1720 return ImplicitConversionSequence::Indistinguishable; 1721 1722 // Two implicit conversion sequences of the same form are 1723 // indistinguishable conversion sequences unless one of the 1724 // following rules apply: (C++ 13.3.3.2p3): 1725 if (ICS1.isStandard()) 1726 return CompareStandardConversionSequences(ICS1.Standard, ICS2.Standard); 1727 else if (ICS1.isUserDefined()) { 1728 // User-defined conversion sequence U1 is a better conversion 1729 // sequence than another user-defined conversion sequence U2 if 1730 // they contain the same user-defined conversion function or 1731 // constructor and if the second standard conversion sequence of 1732 // U1 is better than the second standard conversion sequence of 1733 // U2 (C++ 13.3.3.2p3). 1734 if (ICS1.UserDefined.ConversionFunction == 1735 ICS2.UserDefined.ConversionFunction) 1736 return CompareStandardConversionSequences(ICS1.UserDefined.After, 1737 ICS2.UserDefined.After); 1738 } 1739 1740 return ImplicitConversionSequence::Indistinguishable; 1741} 1742 1743// Per 13.3.3.2p3, compare the given standard conversion sequences to 1744// determine if one is a proper subset of the other. 1745static ImplicitConversionSequence::CompareKind 1746compareStandardConversionSubsets(ASTContext &Context, 1747 const StandardConversionSequence& SCS1, 1748 const StandardConversionSequence& SCS2) { 1749 ImplicitConversionSequence::CompareKind Result 1750 = ImplicitConversionSequence::Indistinguishable; 1751 1752 if (SCS1.Second != SCS2.Second) { 1753 if (SCS1.Second == ICK_Identity) 1754 Result = ImplicitConversionSequence::Better; 1755 else if (SCS2.Second == ICK_Identity) 1756 Result = ImplicitConversionSequence::Worse; 1757 else 1758 return ImplicitConversionSequence::Indistinguishable; 1759 } else if (!Context.hasSameType(SCS1.getToType(1), SCS2.getToType(1))) 1760 return ImplicitConversionSequence::Indistinguishable; 1761 1762 if (SCS1.Third == SCS2.Third) { 1763 return Context.hasSameType(SCS1.getToType(2), SCS2.getToType(2))? Result 1764 : ImplicitConversionSequence::Indistinguishable; 1765 } 1766 1767 if (SCS1.Third == ICK_Identity) 1768 return Result == ImplicitConversionSequence::Worse 1769 ? ImplicitConversionSequence::Indistinguishable 1770 : ImplicitConversionSequence::Better; 1771 1772 if (SCS2.Third == ICK_Identity) 1773 return Result == ImplicitConversionSequence::Better 1774 ? ImplicitConversionSequence::Indistinguishable 1775 : ImplicitConversionSequence::Worse; 1776 1777 return ImplicitConversionSequence::Indistinguishable; 1778} 1779 1780/// CompareStandardConversionSequences - Compare two standard 1781/// conversion sequences to determine whether one is better than the 1782/// other or if they are indistinguishable (C++ 13.3.3.2p3). 1783ImplicitConversionSequence::CompareKind 1784Sema::CompareStandardConversionSequences(const StandardConversionSequence& SCS1, 1785 const StandardConversionSequence& SCS2) 1786{ 1787 // Standard conversion sequence S1 is a better conversion sequence 1788 // than standard conversion sequence S2 if (C++ 13.3.3.2p3): 1789 1790 // -- S1 is a proper subsequence of S2 (comparing the conversion 1791 // sequences in the canonical form defined by 13.3.3.1.1, 1792 // excluding any Lvalue Transformation; the identity conversion 1793 // sequence is considered to be a subsequence of any 1794 // non-identity conversion sequence) or, if not that, 1795 if (ImplicitConversionSequence::CompareKind CK 1796 = compareStandardConversionSubsets(Context, SCS1, SCS2)) 1797 return CK; 1798 1799 // -- the rank of S1 is better than the rank of S2 (by the rules 1800 // defined below), or, if not that, 1801 ImplicitConversionRank Rank1 = SCS1.getRank(); 1802 ImplicitConversionRank Rank2 = SCS2.getRank(); 1803 if (Rank1 < Rank2) 1804 return ImplicitConversionSequence::Better; 1805 else if (Rank2 < Rank1) 1806 return ImplicitConversionSequence::Worse; 1807 1808 // (C++ 13.3.3.2p4): Two conversion sequences with the same rank 1809 // are indistinguishable unless one of the following rules 1810 // applies: 1811 1812 // A conversion that is not a conversion of a pointer, or 1813 // pointer to member, to bool is better than another conversion 1814 // that is such a conversion. 1815 if (SCS1.isPointerConversionToBool() != SCS2.isPointerConversionToBool()) 1816 return SCS2.isPointerConversionToBool() 1817 ? ImplicitConversionSequence::Better 1818 : ImplicitConversionSequence::Worse; 1819 1820 // C++ [over.ics.rank]p4b2: 1821 // 1822 // If class B is derived directly or indirectly from class A, 1823 // conversion of B* to A* is better than conversion of B* to 1824 // void*, and conversion of A* to void* is better than conversion 1825 // of B* to void*. 1826 bool SCS1ConvertsToVoid 1827 = SCS1.isPointerConversionToVoidPointer(Context); 1828 bool SCS2ConvertsToVoid 1829 = SCS2.isPointerConversionToVoidPointer(Context); 1830 if (SCS1ConvertsToVoid != SCS2ConvertsToVoid) { 1831 // Exactly one of the conversion sequences is a conversion to 1832 // a void pointer; it's the worse conversion. 1833 return SCS2ConvertsToVoid ? ImplicitConversionSequence::Better 1834 : ImplicitConversionSequence::Worse; 1835 } else if (!SCS1ConvertsToVoid && !SCS2ConvertsToVoid) { 1836 // Neither conversion sequence converts to a void pointer; compare 1837 // their derived-to-base conversions. 1838 if (ImplicitConversionSequence::CompareKind DerivedCK 1839 = CompareDerivedToBaseConversions(SCS1, SCS2)) 1840 return DerivedCK; 1841 } else if (SCS1ConvertsToVoid && SCS2ConvertsToVoid) { 1842 // Both conversion sequences are conversions to void 1843 // pointers. Compare the source types to determine if there's an 1844 // inheritance relationship in their sources. 1845 QualType FromType1 = SCS1.getFromType(); 1846 QualType FromType2 = SCS2.getFromType(); 1847 1848 // Adjust the types we're converting from via the array-to-pointer 1849 // conversion, if we need to. 1850 if (SCS1.First == ICK_Array_To_Pointer) 1851 FromType1 = Context.getArrayDecayedType(FromType1); 1852 if (SCS2.First == ICK_Array_To_Pointer) 1853 FromType2 = Context.getArrayDecayedType(FromType2); 1854 1855 QualType FromPointee1 1856 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1857 QualType FromPointee2 1858 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1859 1860 if (IsDerivedFrom(FromPointee2, FromPointee1)) 1861 return ImplicitConversionSequence::Better; 1862 else if (IsDerivedFrom(FromPointee1, FromPointee2)) 1863 return ImplicitConversionSequence::Worse; 1864 1865 // Objective-C++: If one interface is more specific than the 1866 // other, it is the better one. 1867 const ObjCInterfaceType* FromIface1 = FromPointee1->getAs<ObjCInterfaceType>(); 1868 const ObjCInterfaceType* FromIface2 = FromPointee2->getAs<ObjCInterfaceType>(); 1869 if (FromIface1 && FromIface1) { 1870 if (Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 1871 return ImplicitConversionSequence::Better; 1872 else if (Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 1873 return ImplicitConversionSequence::Worse; 1874 } 1875 } 1876 1877 // Compare based on qualification conversions (C++ 13.3.3.2p3, 1878 // bullet 3). 1879 if (ImplicitConversionSequence::CompareKind QualCK 1880 = CompareQualificationConversions(SCS1, SCS2)) 1881 return QualCK; 1882 1883 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding) { 1884 // C++0x [over.ics.rank]p3b4: 1885 // -- S1 and S2 are reference bindings (8.5.3) and neither refers to an 1886 // implicit object parameter of a non-static member function declared 1887 // without a ref-qualifier, and S1 binds an rvalue reference to an 1888 // rvalue and S2 binds an lvalue reference. 1889 // FIXME: We don't know if we're dealing with the implicit object parameter, 1890 // or if the member function in this case has a ref qualifier. 1891 // (Of course, we don't have ref qualifiers yet.) 1892 if (SCS1.RRefBinding != SCS2.RRefBinding) 1893 return SCS1.RRefBinding ? ImplicitConversionSequence::Better 1894 : ImplicitConversionSequence::Worse; 1895 1896 // C++ [over.ics.rank]p3b4: 1897 // -- S1 and S2 are reference bindings (8.5.3), and the types to 1898 // which the references refer are the same type except for 1899 // top-level cv-qualifiers, and the type to which the reference 1900 // initialized by S2 refers is more cv-qualified than the type 1901 // to which the reference initialized by S1 refers. 1902 QualType T1 = SCS1.getToType(2); 1903 QualType T2 = SCS2.getToType(2); 1904 T1 = Context.getCanonicalType(T1); 1905 T2 = Context.getCanonicalType(T2); 1906 Qualifiers T1Quals, T2Quals; 1907 QualType UnqualT1 = Context.getUnqualifiedArrayType(T1, T1Quals); 1908 QualType UnqualT2 = Context.getUnqualifiedArrayType(T2, T2Quals); 1909 if (UnqualT1 == UnqualT2) { 1910 // If the type is an array type, promote the element qualifiers to the type 1911 // for comparison. 1912 if (isa<ArrayType>(T1) && T1Quals) 1913 T1 = Context.getQualifiedType(UnqualT1, T1Quals); 1914 if (isa<ArrayType>(T2) && T2Quals) 1915 T2 = Context.getQualifiedType(UnqualT2, T2Quals); 1916 if (T2.isMoreQualifiedThan(T1)) 1917 return ImplicitConversionSequence::Better; 1918 else if (T1.isMoreQualifiedThan(T2)) 1919 return ImplicitConversionSequence::Worse; 1920 } 1921 } 1922 1923 return ImplicitConversionSequence::Indistinguishable; 1924} 1925 1926/// CompareQualificationConversions - Compares two standard conversion 1927/// sequences to determine whether they can be ranked based on their 1928/// qualification conversions (C++ 13.3.3.2p3 bullet 3). 1929ImplicitConversionSequence::CompareKind 1930Sema::CompareQualificationConversions(const StandardConversionSequence& SCS1, 1931 const StandardConversionSequence& SCS2) { 1932 // C++ 13.3.3.2p3: 1933 // -- S1 and S2 differ only in their qualification conversion and 1934 // yield similar types T1 and T2 (C++ 4.4), respectively, and the 1935 // cv-qualification signature of type T1 is a proper subset of 1936 // the cv-qualification signature of type T2, and S1 is not the 1937 // deprecated string literal array-to-pointer conversion (4.2). 1938 if (SCS1.First != SCS2.First || SCS1.Second != SCS2.Second || 1939 SCS1.Third != SCS2.Third || SCS1.Third != ICK_Qualification) 1940 return ImplicitConversionSequence::Indistinguishable; 1941 1942 // FIXME: the example in the standard doesn't use a qualification 1943 // conversion (!) 1944 QualType T1 = SCS1.getToType(2); 1945 QualType T2 = SCS2.getToType(2); 1946 T1 = Context.getCanonicalType(T1); 1947 T2 = Context.getCanonicalType(T2); 1948 Qualifiers T1Quals, T2Quals; 1949 QualType UnqualT1 = Context.getUnqualifiedArrayType(T1, T1Quals); 1950 QualType UnqualT2 = Context.getUnqualifiedArrayType(T2, T2Quals); 1951 1952 // If the types are the same, we won't learn anything by unwrapped 1953 // them. 1954 if (UnqualT1 == UnqualT2) 1955 return ImplicitConversionSequence::Indistinguishable; 1956 1957 // If the type is an array type, promote the element qualifiers to the type 1958 // for comparison. 1959 if (isa<ArrayType>(T1) && T1Quals) 1960 T1 = Context.getQualifiedType(UnqualT1, T1Quals); 1961 if (isa<ArrayType>(T2) && T2Quals) 1962 T2 = Context.getQualifiedType(UnqualT2, T2Quals); 1963 1964 ImplicitConversionSequence::CompareKind Result 1965 = ImplicitConversionSequence::Indistinguishable; 1966 while (UnwrapSimilarPointerTypes(T1, T2)) { 1967 // Within each iteration of the loop, we check the qualifiers to 1968 // determine if this still looks like a qualification 1969 // conversion. Then, if all is well, we unwrap one more level of 1970 // pointers or pointers-to-members and do it all again 1971 // until there are no more pointers or pointers-to-members left 1972 // to unwrap. This essentially mimics what 1973 // IsQualificationConversion does, but here we're checking for a 1974 // strict subset of qualifiers. 1975 if (T1.getCVRQualifiers() == T2.getCVRQualifiers()) 1976 // The qualifiers are the same, so this doesn't tell us anything 1977 // about how the sequences rank. 1978 ; 1979 else if (T2.isMoreQualifiedThan(T1)) { 1980 // T1 has fewer qualifiers, so it could be the better sequence. 1981 if (Result == ImplicitConversionSequence::Worse) 1982 // Neither has qualifiers that are a subset of the other's 1983 // qualifiers. 1984 return ImplicitConversionSequence::Indistinguishable; 1985 1986 Result = ImplicitConversionSequence::Better; 1987 } else if (T1.isMoreQualifiedThan(T2)) { 1988 // T2 has fewer qualifiers, so it could be the better sequence. 1989 if (Result == ImplicitConversionSequence::Better) 1990 // Neither has qualifiers that are a subset of the other's 1991 // qualifiers. 1992 return ImplicitConversionSequence::Indistinguishable; 1993 1994 Result = ImplicitConversionSequence::Worse; 1995 } else { 1996 // Qualifiers are disjoint. 1997 return ImplicitConversionSequence::Indistinguishable; 1998 } 1999 2000 // If the types after this point are equivalent, we're done. 2001 if (Context.hasSameUnqualifiedType(T1, T2)) 2002 break; 2003 } 2004 2005 // Check that the winning standard conversion sequence isn't using 2006 // the deprecated string literal array to pointer conversion. 2007 switch (Result) { 2008 case ImplicitConversionSequence::Better: 2009 if (SCS1.DeprecatedStringLiteralToCharPtr) 2010 Result = ImplicitConversionSequence::Indistinguishable; 2011 break; 2012 2013 case ImplicitConversionSequence::Indistinguishable: 2014 break; 2015 2016 case ImplicitConversionSequence::Worse: 2017 if (SCS2.DeprecatedStringLiteralToCharPtr) 2018 Result = ImplicitConversionSequence::Indistinguishable; 2019 break; 2020 } 2021 2022 return Result; 2023} 2024 2025/// CompareDerivedToBaseConversions - Compares two standard conversion 2026/// sequences to determine whether they can be ranked based on their 2027/// various kinds of derived-to-base conversions (C++ 2028/// [over.ics.rank]p4b3). As part of these checks, we also look at 2029/// conversions between Objective-C interface types. 2030ImplicitConversionSequence::CompareKind 2031Sema::CompareDerivedToBaseConversions(const StandardConversionSequence& SCS1, 2032 const StandardConversionSequence& SCS2) { 2033 QualType FromType1 = SCS1.getFromType(); 2034 QualType ToType1 = SCS1.getToType(1); 2035 QualType FromType2 = SCS2.getFromType(); 2036 QualType ToType2 = SCS2.getToType(1); 2037 2038 // Adjust the types we're converting from via the array-to-pointer 2039 // conversion, if we need to. 2040 if (SCS1.First == ICK_Array_To_Pointer) 2041 FromType1 = Context.getArrayDecayedType(FromType1); 2042 if (SCS2.First == ICK_Array_To_Pointer) 2043 FromType2 = Context.getArrayDecayedType(FromType2); 2044 2045 // Canonicalize all of the types. 2046 FromType1 = Context.getCanonicalType(FromType1); 2047 ToType1 = Context.getCanonicalType(ToType1); 2048 FromType2 = Context.getCanonicalType(FromType2); 2049 ToType2 = Context.getCanonicalType(ToType2); 2050 2051 // C++ [over.ics.rank]p4b3: 2052 // 2053 // If class B is derived directly or indirectly from class A and 2054 // class C is derived directly or indirectly from B, 2055 // 2056 // For Objective-C, we let A, B, and C also be Objective-C 2057 // interfaces. 2058 2059 // Compare based on pointer conversions. 2060 if (SCS1.Second == ICK_Pointer_Conversion && 2061 SCS2.Second == ICK_Pointer_Conversion && 2062 /*FIXME: Remove if Objective-C id conversions get their own rank*/ 2063 FromType1->isPointerType() && FromType2->isPointerType() && 2064 ToType1->isPointerType() && ToType2->isPointerType()) { 2065 QualType FromPointee1 2066 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2067 QualType ToPointee1 2068 = ToType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2069 QualType FromPointee2 2070 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2071 QualType ToPointee2 2072 = ToType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2073 2074 const ObjCInterfaceType* FromIface1 = FromPointee1->getAs<ObjCInterfaceType>(); 2075 const ObjCInterfaceType* FromIface2 = FromPointee2->getAs<ObjCInterfaceType>(); 2076 const ObjCInterfaceType* ToIface1 = ToPointee1->getAs<ObjCInterfaceType>(); 2077 const ObjCInterfaceType* ToIface2 = ToPointee2->getAs<ObjCInterfaceType>(); 2078 2079 // -- conversion of C* to B* is better than conversion of C* to A*, 2080 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 2081 if (IsDerivedFrom(ToPointee1, ToPointee2)) 2082 return ImplicitConversionSequence::Better; 2083 else if (IsDerivedFrom(ToPointee2, ToPointee1)) 2084 return ImplicitConversionSequence::Worse; 2085 2086 if (ToIface1 && ToIface2) { 2087 if (Context.canAssignObjCInterfaces(ToIface2, ToIface1)) 2088 return ImplicitConversionSequence::Better; 2089 else if (Context.canAssignObjCInterfaces(ToIface1, ToIface2)) 2090 return ImplicitConversionSequence::Worse; 2091 } 2092 } 2093 2094 // -- conversion of B* to A* is better than conversion of C* to A*, 2095 if (FromPointee1 != FromPointee2 && ToPointee1 == ToPointee2) { 2096 if (IsDerivedFrom(FromPointee2, FromPointee1)) 2097 return ImplicitConversionSequence::Better; 2098 else if (IsDerivedFrom(FromPointee1, FromPointee2)) 2099 return ImplicitConversionSequence::Worse; 2100 2101 if (FromIface1 && FromIface2) { 2102 if (Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 2103 return ImplicitConversionSequence::Better; 2104 else if (Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 2105 return ImplicitConversionSequence::Worse; 2106 } 2107 } 2108 } 2109 2110 // Ranking of member-pointer types. 2111 if (SCS1.Second == ICK_Pointer_Member && SCS2.Second == ICK_Pointer_Member && 2112 FromType1->isMemberPointerType() && FromType2->isMemberPointerType() && 2113 ToType1->isMemberPointerType() && ToType2->isMemberPointerType()) { 2114 const MemberPointerType * FromMemPointer1 = 2115 FromType1->getAs<MemberPointerType>(); 2116 const MemberPointerType * ToMemPointer1 = 2117 ToType1->getAs<MemberPointerType>(); 2118 const MemberPointerType * FromMemPointer2 = 2119 FromType2->getAs<MemberPointerType>(); 2120 const MemberPointerType * ToMemPointer2 = 2121 ToType2->getAs<MemberPointerType>(); 2122 const Type *FromPointeeType1 = FromMemPointer1->getClass(); 2123 const Type *ToPointeeType1 = ToMemPointer1->getClass(); 2124 const Type *FromPointeeType2 = FromMemPointer2->getClass(); 2125 const Type *ToPointeeType2 = ToMemPointer2->getClass(); 2126 QualType FromPointee1 = QualType(FromPointeeType1, 0).getUnqualifiedType(); 2127 QualType ToPointee1 = QualType(ToPointeeType1, 0).getUnqualifiedType(); 2128 QualType FromPointee2 = QualType(FromPointeeType2, 0).getUnqualifiedType(); 2129 QualType ToPointee2 = QualType(ToPointeeType2, 0).getUnqualifiedType(); 2130 // conversion of A::* to B::* is better than conversion of A::* to C::*, 2131 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 2132 if (IsDerivedFrom(ToPointee1, ToPointee2)) 2133 return ImplicitConversionSequence::Worse; 2134 else if (IsDerivedFrom(ToPointee2, ToPointee1)) 2135 return ImplicitConversionSequence::Better; 2136 } 2137 // conversion of B::* to C::* is better than conversion of A::* to C::* 2138 if (ToPointee1 == ToPointee2 && FromPointee1 != FromPointee2) { 2139 if (IsDerivedFrom(FromPointee1, FromPointee2)) 2140 return ImplicitConversionSequence::Better; 2141 else if (IsDerivedFrom(FromPointee2, FromPointee1)) 2142 return ImplicitConversionSequence::Worse; 2143 } 2144 } 2145 2146 if ((SCS1.ReferenceBinding || SCS1.CopyConstructor) && 2147 (SCS2.ReferenceBinding || SCS2.CopyConstructor) && 2148 SCS1.Second == ICK_Derived_To_Base) { 2149 // -- conversion of C to B is better than conversion of C to A, 2150 // -- binding of an expression of type C to a reference of type 2151 // B& is better than binding an expression of type C to a 2152 // reference of type A&, 2153 if (Context.hasSameUnqualifiedType(FromType1, FromType2) && 2154 !Context.hasSameUnqualifiedType(ToType1, ToType2)) { 2155 if (IsDerivedFrom(ToType1, ToType2)) 2156 return ImplicitConversionSequence::Better; 2157 else if (IsDerivedFrom(ToType2, ToType1)) 2158 return ImplicitConversionSequence::Worse; 2159 } 2160 2161 // -- conversion of B to A is better than conversion of C to A. 2162 // -- binding of an expression of type B to a reference of type 2163 // A& is better than binding an expression of type C to a 2164 // reference of type A&, 2165 if (!Context.hasSameUnqualifiedType(FromType1, FromType2) && 2166 Context.hasSameUnqualifiedType(ToType1, ToType2)) { 2167 if (IsDerivedFrom(FromType2, FromType1)) 2168 return ImplicitConversionSequence::Better; 2169 else if (IsDerivedFrom(FromType1, FromType2)) 2170 return ImplicitConversionSequence::Worse; 2171 } 2172 } 2173 2174 return ImplicitConversionSequence::Indistinguishable; 2175} 2176 2177/// CompareReferenceRelationship - Compare the two types T1 and T2 to 2178/// determine whether they are reference-related, 2179/// reference-compatible, reference-compatible with added 2180/// qualification, or incompatible, for use in C++ initialization by 2181/// reference (C++ [dcl.ref.init]p4). Neither type can be a reference 2182/// type, and the first type (T1) is the pointee type of the reference 2183/// type being initialized. 2184Sema::ReferenceCompareResult 2185Sema::CompareReferenceRelationship(SourceLocation Loc, 2186 QualType OrigT1, QualType OrigT2, 2187 bool& DerivedToBase) { 2188 assert(!OrigT1->isReferenceType() && 2189 "T1 must be the pointee type of the reference type"); 2190 assert(!OrigT2->isReferenceType() && "T2 cannot be a reference type"); 2191 2192 QualType T1 = Context.getCanonicalType(OrigT1); 2193 QualType T2 = Context.getCanonicalType(OrigT2); 2194 Qualifiers T1Quals, T2Quals; 2195 QualType UnqualT1 = Context.getUnqualifiedArrayType(T1, T1Quals); 2196 QualType UnqualT2 = Context.getUnqualifiedArrayType(T2, T2Quals); 2197 2198 // C++ [dcl.init.ref]p4: 2199 // Given types "cv1 T1" and "cv2 T2," "cv1 T1" is 2200 // reference-related to "cv2 T2" if T1 is the same type as T2, or 2201 // T1 is a base class of T2. 2202 if (UnqualT1 == UnqualT2) 2203 DerivedToBase = false; 2204 else if (!RequireCompleteType(Loc, OrigT1, PDiag()) && 2205 !RequireCompleteType(Loc, OrigT2, PDiag()) && 2206 IsDerivedFrom(UnqualT2, UnqualT1)) 2207 DerivedToBase = true; 2208 else 2209 return Ref_Incompatible; 2210 2211 // At this point, we know that T1 and T2 are reference-related (at 2212 // least). 2213 2214 // If the type is an array type, promote the element qualifiers to the type 2215 // for comparison. 2216 if (isa<ArrayType>(T1) && T1Quals) 2217 T1 = Context.getQualifiedType(UnqualT1, T1Quals); 2218 if (isa<ArrayType>(T2) && T2Quals) 2219 T2 = Context.getQualifiedType(UnqualT2, T2Quals); 2220 2221 // C++ [dcl.init.ref]p4: 2222 // "cv1 T1" is reference-compatible with "cv2 T2" if T1 is 2223 // reference-related to T2 and cv1 is the same cv-qualification 2224 // as, or greater cv-qualification than, cv2. For purposes of 2225 // overload resolution, cases for which cv1 is greater 2226 // cv-qualification than cv2 are identified as 2227 // reference-compatible with added qualification (see 13.3.3.2). 2228 if (T1Quals.getCVRQualifiers() == T2Quals.getCVRQualifiers()) 2229 return Ref_Compatible; 2230 else if (T1.isMoreQualifiedThan(T2)) 2231 return Ref_Compatible_With_Added_Qualification; 2232 else 2233 return Ref_Related; 2234} 2235 2236/// \brief Compute an implicit conversion sequence for reference 2237/// initialization. 2238static ImplicitConversionSequence 2239TryReferenceInit(Sema &S, Expr *&Init, QualType DeclType, 2240 SourceLocation DeclLoc, 2241 bool SuppressUserConversions, 2242 bool AllowExplicit) { 2243 assert(DeclType->isReferenceType() && "Reference init needs a reference"); 2244 2245 // Most paths end in a failed conversion. 2246 ImplicitConversionSequence ICS; 2247 ICS.setBad(BadConversionSequence::no_conversion, Init, DeclType); 2248 2249 QualType T1 = DeclType->getAs<ReferenceType>()->getPointeeType(); 2250 QualType T2 = Init->getType(); 2251 2252 // If the initializer is the address of an overloaded function, try 2253 // to resolve the overloaded function. If all goes well, T2 is the 2254 // type of the resulting function. 2255 if (S.Context.getCanonicalType(T2) == S.Context.OverloadTy) { 2256 DeclAccessPair Found; 2257 if (FunctionDecl *Fn = S.ResolveAddressOfOverloadedFunction(Init, DeclType, 2258 false, Found)) 2259 T2 = Fn->getType(); 2260 } 2261 2262 // Compute some basic properties of the types and the initializer. 2263 bool isRValRef = DeclType->isRValueReferenceType(); 2264 bool DerivedToBase = false; 2265 Expr::isLvalueResult InitLvalue = Init->isLvalue(S.Context); 2266 Sema::ReferenceCompareResult RefRelationship 2267 = S.CompareReferenceRelationship(DeclLoc, T1, T2, DerivedToBase); 2268 2269 // C++ [dcl.init.ref]p5: 2270 // A reference to type "cv1 T1" is initialized by an expression 2271 // of type "cv2 T2" as follows: 2272 2273 // -- If the initializer expression 2274 2275 // C++ [over.ics.ref]p3: 2276 // Except for an implicit object parameter, for which see 13.3.1, 2277 // a standard conversion sequence cannot be formed if it requires 2278 // binding an lvalue reference to non-const to an rvalue or 2279 // binding an rvalue reference to an lvalue. 2280 if (isRValRef && InitLvalue == Expr::LV_Valid) 2281 return ICS; 2282 2283 // -- is an lvalue (but is not a bit-field), and "cv1 T1" is 2284 // reference-compatible with "cv2 T2," or 2285 // 2286 // Per C++ [over.ics.ref]p4, we don't check the bit-field property here. 2287 if (InitLvalue == Expr::LV_Valid && 2288 RefRelationship >= Sema::Ref_Compatible_With_Added_Qualification) { 2289 // C++ [over.ics.ref]p1: 2290 // When a parameter of reference type binds directly (8.5.3) 2291 // to an argument expression, the implicit conversion sequence 2292 // is the identity conversion, unless the argument expression 2293 // has a type that is a derived class of the parameter type, 2294 // in which case the implicit conversion sequence is a 2295 // derived-to-base Conversion (13.3.3.1). 2296 ICS.setStandard(); 2297 ICS.Standard.First = ICK_Identity; 2298 ICS.Standard.Second = DerivedToBase? ICK_Derived_To_Base : ICK_Identity; 2299 ICS.Standard.Third = ICK_Identity; 2300 ICS.Standard.FromTypePtr = T2.getAsOpaquePtr(); 2301 ICS.Standard.setToType(0, T2); 2302 ICS.Standard.setToType(1, T1); 2303 ICS.Standard.setToType(2, T1); 2304 ICS.Standard.ReferenceBinding = true; 2305 ICS.Standard.DirectBinding = true; 2306 ICS.Standard.RRefBinding = false; 2307 ICS.Standard.CopyConstructor = 0; 2308 2309 // Nothing more to do: the inaccessibility/ambiguity check for 2310 // derived-to-base conversions is suppressed when we're 2311 // computing the implicit conversion sequence (C++ 2312 // [over.best.ics]p2). 2313 return ICS; 2314 } 2315 2316 // -- has a class type (i.e., T2 is a class type), where T1 is 2317 // not reference-related to T2, and can be implicitly 2318 // converted to an lvalue of type "cv3 T3," where "cv1 T1" 2319 // is reference-compatible with "cv3 T3" 92) (this 2320 // conversion is selected by enumerating the applicable 2321 // conversion functions (13.3.1.6) and choosing the best 2322 // one through overload resolution (13.3)), 2323 if (!isRValRef && !SuppressUserConversions && T2->isRecordType() && 2324 !S.RequireCompleteType(DeclLoc, T2, 0) && 2325 RefRelationship == Sema::Ref_Incompatible) { 2326 CXXRecordDecl *T2RecordDecl 2327 = dyn_cast<CXXRecordDecl>(T2->getAs<RecordType>()->getDecl()); 2328 2329 OverloadCandidateSet CandidateSet(DeclLoc); 2330 const UnresolvedSetImpl *Conversions 2331 = T2RecordDecl->getVisibleConversionFunctions(); 2332 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 2333 E = Conversions->end(); I != E; ++I) { 2334 NamedDecl *D = *I; 2335 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(D->getDeclContext()); 2336 if (isa<UsingShadowDecl>(D)) 2337 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 2338 2339 FunctionTemplateDecl *ConvTemplate 2340 = dyn_cast<FunctionTemplateDecl>(D); 2341 CXXConversionDecl *Conv; 2342 if (ConvTemplate) 2343 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 2344 else 2345 Conv = cast<CXXConversionDecl>(D); 2346 2347 // If the conversion function doesn't return a reference type, 2348 // it can't be considered for this conversion. 2349 if (Conv->getConversionType()->isLValueReferenceType() && 2350 (AllowExplicit || !Conv->isExplicit())) { 2351 if (ConvTemplate) 2352 S.AddTemplateConversionCandidate(ConvTemplate, I.getPair(), ActingDC, 2353 Init, DeclType, CandidateSet); 2354 else 2355 S.AddConversionCandidate(Conv, I.getPair(), ActingDC, Init, 2356 DeclType, CandidateSet); 2357 } 2358 } 2359 2360 OverloadCandidateSet::iterator Best; 2361 switch (S.BestViableFunction(CandidateSet, DeclLoc, Best)) { 2362 case OR_Success: 2363 // C++ [over.ics.ref]p1: 2364 // 2365 // [...] If the parameter binds directly to the result of 2366 // applying a conversion function to the argument 2367 // expression, the implicit conversion sequence is a 2368 // user-defined conversion sequence (13.3.3.1.2), with the 2369 // second standard conversion sequence either an identity 2370 // conversion or, if the conversion function returns an 2371 // entity of a type that is a derived class of the parameter 2372 // type, a derived-to-base Conversion. 2373 if (!Best->FinalConversion.DirectBinding) 2374 break; 2375 2376 ICS.setUserDefined(); 2377 ICS.UserDefined.Before = Best->Conversions[0].Standard; 2378 ICS.UserDefined.After = Best->FinalConversion; 2379 ICS.UserDefined.ConversionFunction = Best->Function; 2380 ICS.UserDefined.EllipsisConversion = false; 2381 assert(ICS.UserDefined.After.ReferenceBinding && 2382 ICS.UserDefined.After.DirectBinding && 2383 "Expected a direct reference binding!"); 2384 return ICS; 2385 2386 case OR_Ambiguous: 2387 ICS.setAmbiguous(); 2388 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 2389 Cand != CandidateSet.end(); ++Cand) 2390 if (Cand->Viable) 2391 ICS.Ambiguous.addConversion(Cand->Function); 2392 return ICS; 2393 2394 case OR_No_Viable_Function: 2395 case OR_Deleted: 2396 // There was no suitable conversion, or we found a deleted 2397 // conversion; continue with other checks. 2398 break; 2399 } 2400 } 2401 2402 // -- Otherwise, the reference shall be to a non-volatile const 2403 // type (i.e., cv1 shall be const), or the reference shall be an 2404 // rvalue reference and the initializer expression shall be an rvalue. 2405 if (!isRValRef && T1.getCVRQualifiers() != Qualifiers::Const) 2406 return ICS; 2407 2408 // -- If the initializer expression is an rvalue, with T2 a 2409 // class type, and "cv1 T1" is reference-compatible with 2410 // "cv2 T2," the reference is bound in one of the 2411 // following ways (the choice is implementation-defined): 2412 // 2413 // -- The reference is bound to the object represented by 2414 // the rvalue (see 3.10) or to a sub-object within that 2415 // object. 2416 // 2417 // -- A temporary of type "cv1 T2" [sic] is created, and 2418 // a constructor is called to copy the entire rvalue 2419 // object into the temporary. The reference is bound to 2420 // the temporary or to a sub-object within the 2421 // temporary. 2422 // 2423 // The constructor that would be used to make the copy 2424 // shall be callable whether or not the copy is actually 2425 // done. 2426 // 2427 // Note that C++0x [dcl.init.ref]p5 takes away this implementation 2428 // freedom, so we will always take the first option and never build 2429 // a temporary in this case. 2430 if (InitLvalue != Expr::LV_Valid && T2->isRecordType() && 2431 RefRelationship >= Sema::Ref_Compatible_With_Added_Qualification) { 2432 ICS.setStandard(); 2433 ICS.Standard.First = ICK_Identity; 2434 ICS.Standard.Second = DerivedToBase? ICK_Derived_To_Base : ICK_Identity; 2435 ICS.Standard.Third = ICK_Identity; 2436 ICS.Standard.FromTypePtr = T2.getAsOpaquePtr(); 2437 ICS.Standard.setToType(0, T2); 2438 ICS.Standard.setToType(1, T1); 2439 ICS.Standard.setToType(2, T1); 2440 ICS.Standard.ReferenceBinding = true; 2441 ICS.Standard.DirectBinding = false; 2442 ICS.Standard.RRefBinding = isRValRef; 2443 ICS.Standard.CopyConstructor = 0; 2444 return ICS; 2445 } 2446 2447 // -- Otherwise, a temporary of type "cv1 T1" is created and 2448 // initialized from the initializer expression using the 2449 // rules for a non-reference copy initialization (8.5). The 2450 // reference is then bound to the temporary. If T1 is 2451 // reference-related to T2, cv1 must be the same 2452 // cv-qualification as, or greater cv-qualification than, 2453 // cv2; otherwise, the program is ill-formed. 2454 if (RefRelationship == Sema::Ref_Related) { 2455 // If cv1 == cv2 or cv1 is a greater cv-qualified than cv2, then 2456 // we would be reference-compatible or reference-compatible with 2457 // added qualification. But that wasn't the case, so the reference 2458 // initialization fails. 2459 return ICS; 2460 } 2461 2462 // If at least one of the types is a class type, the types are not 2463 // related, and we aren't allowed any user conversions, the 2464 // reference binding fails. This case is important for breaking 2465 // recursion, since TryImplicitConversion below will attempt to 2466 // create a temporary through the use of a copy constructor. 2467 if (SuppressUserConversions && RefRelationship == Sema::Ref_Incompatible && 2468 (T1->isRecordType() || T2->isRecordType())) 2469 return ICS; 2470 2471 // C++ [over.ics.ref]p2: 2472 // 2473 // When a parameter of reference type is not bound directly to 2474 // an argument expression, the conversion sequence is the one 2475 // required to convert the argument expression to the 2476 // underlying type of the reference according to 2477 // 13.3.3.1. Conceptually, this conversion sequence corresponds 2478 // to copy-initializing a temporary of the underlying type with 2479 // the argument expression. Any difference in top-level 2480 // cv-qualification is subsumed by the initialization itself 2481 // and does not constitute a conversion. 2482 ICS = S.TryImplicitConversion(Init, T1, SuppressUserConversions, 2483 /*AllowExplicit=*/false, 2484 /*InOverloadResolution=*/false); 2485 2486 // Of course, that's still a reference binding. 2487 if (ICS.isStandard()) { 2488 ICS.Standard.ReferenceBinding = true; 2489 ICS.Standard.RRefBinding = isRValRef; 2490 } else if (ICS.isUserDefined()) { 2491 ICS.UserDefined.After.ReferenceBinding = true; 2492 ICS.UserDefined.After.RRefBinding = isRValRef; 2493 } 2494 return ICS; 2495} 2496 2497/// TryCopyInitialization - Try to copy-initialize a value of type 2498/// ToType from the expression From. Return the implicit conversion 2499/// sequence required to pass this argument, which may be a bad 2500/// conversion sequence (meaning that the argument cannot be passed to 2501/// a parameter of this type). If @p SuppressUserConversions, then we 2502/// do not permit any user-defined conversion sequences. 2503static ImplicitConversionSequence 2504TryCopyInitialization(Sema &S, Expr *From, QualType ToType, 2505 bool SuppressUserConversions, 2506 bool InOverloadResolution) { 2507 if (ToType->isReferenceType()) 2508 return TryReferenceInit(S, From, ToType, 2509 /*FIXME:*/From->getLocStart(), 2510 SuppressUserConversions, 2511 /*AllowExplicit=*/false); 2512 2513 return S.TryImplicitConversion(From, ToType, 2514 SuppressUserConversions, 2515 /*AllowExplicit=*/false, 2516 InOverloadResolution); 2517} 2518 2519/// TryObjectArgumentInitialization - Try to initialize the object 2520/// parameter of the given member function (@c Method) from the 2521/// expression @p From. 2522ImplicitConversionSequence 2523Sema::TryObjectArgumentInitialization(QualType OrigFromType, 2524 CXXMethodDecl *Method, 2525 CXXRecordDecl *ActingContext) { 2526 QualType ClassType = Context.getTypeDeclType(ActingContext); 2527 // [class.dtor]p2: A destructor can be invoked for a const, volatile or 2528 // const volatile object. 2529 unsigned Quals = isa<CXXDestructorDecl>(Method) ? 2530 Qualifiers::Const | Qualifiers::Volatile : Method->getTypeQualifiers(); 2531 QualType ImplicitParamType = Context.getCVRQualifiedType(ClassType, Quals); 2532 2533 // Set up the conversion sequence as a "bad" conversion, to allow us 2534 // to exit early. 2535 ImplicitConversionSequence ICS; 2536 2537 // We need to have an object of class type. 2538 QualType FromType = OrigFromType; 2539 if (const PointerType *PT = FromType->getAs<PointerType>()) 2540 FromType = PT->getPointeeType(); 2541 2542 assert(FromType->isRecordType()); 2543 2544 // The implicit object parameter is has the type "reference to cv X", 2545 // where X is the class of which the function is a member 2546 // (C++ [over.match.funcs]p4). However, when finding an implicit 2547 // conversion sequence for the argument, we are not allowed to 2548 // create temporaries or perform user-defined conversions 2549 // (C++ [over.match.funcs]p5). We perform a simplified version of 2550 // reference binding here, that allows class rvalues to bind to 2551 // non-constant references. 2552 2553 // First check the qualifiers. We don't care about lvalue-vs-rvalue 2554 // with the implicit object parameter (C++ [over.match.funcs]p5). 2555 QualType FromTypeCanon = Context.getCanonicalType(FromType); 2556 if (ImplicitParamType.getCVRQualifiers() 2557 != FromTypeCanon.getLocalCVRQualifiers() && 2558 !ImplicitParamType.isAtLeastAsQualifiedAs(FromTypeCanon)) { 2559 ICS.setBad(BadConversionSequence::bad_qualifiers, 2560 OrigFromType, ImplicitParamType); 2561 return ICS; 2562 } 2563 2564 // Check that we have either the same type or a derived type. It 2565 // affects the conversion rank. 2566 QualType ClassTypeCanon = Context.getCanonicalType(ClassType); 2567 ImplicitConversionKind SecondKind; 2568 if (ClassTypeCanon == FromTypeCanon.getLocalUnqualifiedType()) { 2569 SecondKind = ICK_Identity; 2570 } else if (IsDerivedFrom(FromType, ClassType)) 2571 SecondKind = ICK_Derived_To_Base; 2572 else { 2573 ICS.setBad(BadConversionSequence::unrelated_class, 2574 FromType, ImplicitParamType); 2575 return ICS; 2576 } 2577 2578 // Success. Mark this as a reference binding. 2579 ICS.setStandard(); 2580 ICS.Standard.setAsIdentityConversion(); 2581 ICS.Standard.Second = SecondKind; 2582 ICS.Standard.setFromType(FromType); 2583 ICS.Standard.setAllToTypes(ImplicitParamType); 2584 ICS.Standard.ReferenceBinding = true; 2585 ICS.Standard.DirectBinding = true; 2586 ICS.Standard.RRefBinding = false; 2587 return ICS; 2588} 2589 2590/// PerformObjectArgumentInitialization - Perform initialization of 2591/// the implicit object parameter for the given Method with the given 2592/// expression. 2593bool 2594Sema::PerformObjectArgumentInitialization(Expr *&From, 2595 NestedNameSpecifier *Qualifier, 2596 NamedDecl *FoundDecl, 2597 CXXMethodDecl *Method) { 2598 QualType FromRecordType, DestType; 2599 QualType ImplicitParamRecordType = 2600 Method->getThisType(Context)->getAs<PointerType>()->getPointeeType(); 2601 2602 if (const PointerType *PT = From->getType()->getAs<PointerType>()) { 2603 FromRecordType = PT->getPointeeType(); 2604 DestType = Method->getThisType(Context); 2605 } else { 2606 FromRecordType = From->getType(); 2607 DestType = ImplicitParamRecordType; 2608 } 2609 2610 // Note that we always use the true parent context when performing 2611 // the actual argument initialization. 2612 ImplicitConversionSequence ICS 2613 = TryObjectArgumentInitialization(From->getType(), Method, 2614 Method->getParent()); 2615 if (ICS.isBad()) 2616 return Diag(From->getSourceRange().getBegin(), 2617 diag::err_implicit_object_parameter_init) 2618 << ImplicitParamRecordType << FromRecordType << From->getSourceRange(); 2619 2620 if (ICS.Standard.Second == ICK_Derived_To_Base) 2621 return PerformObjectMemberConversion(From, Qualifier, FoundDecl, Method); 2622 2623 if (!Context.hasSameType(From->getType(), DestType)) 2624 ImpCastExprToType(From, DestType, CastExpr::CK_NoOp, 2625 /*isLvalue=*/!From->getType()->getAs<PointerType>()); 2626 return false; 2627} 2628 2629/// TryContextuallyConvertToBool - Attempt to contextually convert the 2630/// expression From to bool (C++0x [conv]p3). 2631ImplicitConversionSequence Sema::TryContextuallyConvertToBool(Expr *From) { 2632 return TryImplicitConversion(From, Context.BoolTy, 2633 // FIXME: Are these flags correct? 2634 /*SuppressUserConversions=*/false, 2635 /*AllowExplicit=*/true, 2636 /*InOverloadResolution=*/false); 2637} 2638 2639/// PerformContextuallyConvertToBool - Perform a contextual conversion 2640/// of the expression From to bool (C++0x [conv]p3). 2641bool Sema::PerformContextuallyConvertToBool(Expr *&From) { 2642 ImplicitConversionSequence ICS = TryContextuallyConvertToBool(From); 2643 if (!ICS.isBad()) 2644 return PerformImplicitConversion(From, Context.BoolTy, ICS, AA_Converting); 2645 2646 if (!DiagnoseMultipleUserDefinedConversion(From, Context.BoolTy)) 2647 return Diag(From->getSourceRange().getBegin(), 2648 diag::err_typecheck_bool_condition) 2649 << From->getType() << From->getSourceRange(); 2650 return true; 2651} 2652 2653/// AddOverloadCandidate - Adds the given function to the set of 2654/// candidate functions, using the given function call arguments. If 2655/// @p SuppressUserConversions, then don't allow user-defined 2656/// conversions via constructors or conversion operators. 2657/// 2658/// \para PartialOverloading true if we are performing "partial" overloading 2659/// based on an incomplete set of function arguments. This feature is used by 2660/// code completion. 2661void 2662Sema::AddOverloadCandidate(FunctionDecl *Function, 2663 DeclAccessPair FoundDecl, 2664 Expr **Args, unsigned NumArgs, 2665 OverloadCandidateSet& CandidateSet, 2666 bool SuppressUserConversions, 2667 bool PartialOverloading) { 2668 const FunctionProtoType* Proto 2669 = dyn_cast<FunctionProtoType>(Function->getType()->getAs<FunctionType>()); 2670 assert(Proto && "Functions without a prototype cannot be overloaded"); 2671 assert(!Function->getDescribedFunctionTemplate() && 2672 "Use AddTemplateOverloadCandidate for function templates"); 2673 2674 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Function)) { 2675 if (!isa<CXXConstructorDecl>(Method)) { 2676 // If we get here, it's because we're calling a member function 2677 // that is named without a member access expression (e.g., 2678 // "this->f") that was either written explicitly or created 2679 // implicitly. This can happen with a qualified call to a member 2680 // function, e.g., X::f(). We use an empty type for the implied 2681 // object argument (C++ [over.call.func]p3), and the acting context 2682 // is irrelevant. 2683 AddMethodCandidate(Method, FoundDecl, Method->getParent(), 2684 QualType(), Args, NumArgs, CandidateSet, 2685 SuppressUserConversions); 2686 return; 2687 } 2688 // We treat a constructor like a non-member function, since its object 2689 // argument doesn't participate in overload resolution. 2690 } 2691 2692 if (!CandidateSet.isNewCandidate(Function)) 2693 return; 2694 2695 // Overload resolution is always an unevaluated context. 2696 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 2697 2698 if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(Function)){ 2699 // C++ [class.copy]p3: 2700 // A member function template is never instantiated to perform the copy 2701 // of a class object to an object of its class type. 2702 QualType ClassType = Context.getTypeDeclType(Constructor->getParent()); 2703 if (NumArgs == 1 && 2704 Constructor->isCopyConstructorLikeSpecialization() && 2705 (Context.hasSameUnqualifiedType(ClassType, Args[0]->getType()) || 2706 IsDerivedFrom(Args[0]->getType(), ClassType))) 2707 return; 2708 } 2709 2710 // Add this candidate 2711 CandidateSet.push_back(OverloadCandidate()); 2712 OverloadCandidate& Candidate = CandidateSet.back(); 2713 Candidate.FoundDecl = FoundDecl; 2714 Candidate.Function = Function; 2715 Candidate.Viable = true; 2716 Candidate.IsSurrogate = false; 2717 Candidate.IgnoreObjectArgument = false; 2718 2719 unsigned NumArgsInProto = Proto->getNumArgs(); 2720 2721 // (C++ 13.3.2p2): A candidate function having fewer than m 2722 // parameters is viable only if it has an ellipsis in its parameter 2723 // list (8.3.5). 2724 if ((NumArgs + (PartialOverloading && NumArgs)) > NumArgsInProto && 2725 !Proto->isVariadic()) { 2726 Candidate.Viable = false; 2727 Candidate.FailureKind = ovl_fail_too_many_arguments; 2728 return; 2729 } 2730 2731 // (C++ 13.3.2p2): A candidate function having more than m parameters 2732 // is viable only if the (m+1)st parameter has a default argument 2733 // (8.3.6). For the purposes of overload resolution, the 2734 // parameter list is truncated on the right, so that there are 2735 // exactly m parameters. 2736 unsigned MinRequiredArgs = Function->getMinRequiredArguments(); 2737 if (NumArgs < MinRequiredArgs && !PartialOverloading) { 2738 // Not enough arguments. 2739 Candidate.Viable = false; 2740 Candidate.FailureKind = ovl_fail_too_few_arguments; 2741 return; 2742 } 2743 2744 // Determine the implicit conversion sequences for each of the 2745 // arguments. 2746 Candidate.Conversions.resize(NumArgs); 2747 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2748 if (ArgIdx < NumArgsInProto) { 2749 // (C++ 13.3.2p3): for F to be a viable function, there shall 2750 // exist for each argument an implicit conversion sequence 2751 // (13.3.3.1) that converts that argument to the corresponding 2752 // parameter of F. 2753 QualType ParamType = Proto->getArgType(ArgIdx); 2754 Candidate.Conversions[ArgIdx] 2755 = TryCopyInitialization(*this, Args[ArgIdx], ParamType, 2756 SuppressUserConversions, 2757 /*InOverloadResolution=*/true); 2758 if (Candidate.Conversions[ArgIdx].isBad()) { 2759 Candidate.Viable = false; 2760 Candidate.FailureKind = ovl_fail_bad_conversion; 2761 break; 2762 } 2763 } else { 2764 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2765 // argument for which there is no corresponding parameter is 2766 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2767 Candidate.Conversions[ArgIdx].setEllipsis(); 2768 } 2769 } 2770} 2771 2772/// \brief Add all of the function declarations in the given function set to 2773/// the overload canddiate set. 2774void Sema::AddFunctionCandidates(const UnresolvedSetImpl &Fns, 2775 Expr **Args, unsigned NumArgs, 2776 OverloadCandidateSet& CandidateSet, 2777 bool SuppressUserConversions) { 2778 for (UnresolvedSetIterator F = Fns.begin(), E = Fns.end(); F != E; ++F) { 2779 NamedDecl *D = F.getDecl()->getUnderlyingDecl(); 2780 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { 2781 if (isa<CXXMethodDecl>(FD) && !cast<CXXMethodDecl>(FD)->isStatic()) 2782 AddMethodCandidate(cast<CXXMethodDecl>(FD), F.getPair(), 2783 cast<CXXMethodDecl>(FD)->getParent(), 2784 Args[0]->getType(), Args + 1, NumArgs - 1, 2785 CandidateSet, SuppressUserConversions); 2786 else 2787 AddOverloadCandidate(FD, F.getPair(), Args, NumArgs, CandidateSet, 2788 SuppressUserConversions); 2789 } else { 2790 FunctionTemplateDecl *FunTmpl = cast<FunctionTemplateDecl>(D); 2791 if (isa<CXXMethodDecl>(FunTmpl->getTemplatedDecl()) && 2792 !cast<CXXMethodDecl>(FunTmpl->getTemplatedDecl())->isStatic()) 2793 AddMethodTemplateCandidate(FunTmpl, F.getPair(), 2794 cast<CXXRecordDecl>(FunTmpl->getDeclContext()), 2795 /*FIXME: explicit args */ 0, 2796 Args[0]->getType(), Args + 1, NumArgs - 1, 2797 CandidateSet, 2798 SuppressUserConversions); 2799 else 2800 AddTemplateOverloadCandidate(FunTmpl, F.getPair(), 2801 /*FIXME: explicit args */ 0, 2802 Args, NumArgs, CandidateSet, 2803 SuppressUserConversions); 2804 } 2805 } 2806} 2807 2808/// AddMethodCandidate - Adds a named decl (which is some kind of 2809/// method) as a method candidate to the given overload set. 2810void Sema::AddMethodCandidate(DeclAccessPair FoundDecl, 2811 QualType ObjectType, 2812 Expr **Args, unsigned NumArgs, 2813 OverloadCandidateSet& CandidateSet, 2814 bool SuppressUserConversions) { 2815 NamedDecl *Decl = FoundDecl.getDecl(); 2816 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(Decl->getDeclContext()); 2817 2818 if (isa<UsingShadowDecl>(Decl)) 2819 Decl = cast<UsingShadowDecl>(Decl)->getTargetDecl(); 2820 2821 if (FunctionTemplateDecl *TD = dyn_cast<FunctionTemplateDecl>(Decl)) { 2822 assert(isa<CXXMethodDecl>(TD->getTemplatedDecl()) && 2823 "Expected a member function template"); 2824 AddMethodTemplateCandidate(TD, FoundDecl, ActingContext, 2825 /*ExplicitArgs*/ 0, 2826 ObjectType, Args, NumArgs, 2827 CandidateSet, 2828 SuppressUserConversions); 2829 } else { 2830 AddMethodCandidate(cast<CXXMethodDecl>(Decl), FoundDecl, ActingContext, 2831 ObjectType, Args, NumArgs, 2832 CandidateSet, SuppressUserConversions); 2833 } 2834} 2835 2836/// AddMethodCandidate - Adds the given C++ member function to the set 2837/// of candidate functions, using the given function call arguments 2838/// and the object argument (@c Object). For example, in a call 2839/// @c o.f(a1,a2), @c Object will contain @c o and @c Args will contain 2840/// both @c a1 and @c a2. If @p SuppressUserConversions, then don't 2841/// allow user-defined conversions via constructors or conversion 2842/// operators. 2843void 2844Sema::AddMethodCandidate(CXXMethodDecl *Method, DeclAccessPair FoundDecl, 2845 CXXRecordDecl *ActingContext, QualType ObjectType, 2846 Expr **Args, unsigned NumArgs, 2847 OverloadCandidateSet& CandidateSet, 2848 bool SuppressUserConversions) { 2849 const FunctionProtoType* Proto 2850 = dyn_cast<FunctionProtoType>(Method->getType()->getAs<FunctionType>()); 2851 assert(Proto && "Methods without a prototype cannot be overloaded"); 2852 assert(!isa<CXXConstructorDecl>(Method) && 2853 "Use AddOverloadCandidate for constructors"); 2854 2855 if (!CandidateSet.isNewCandidate(Method)) 2856 return; 2857 2858 // Overload resolution is always an unevaluated context. 2859 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 2860 2861 // Add this candidate 2862 CandidateSet.push_back(OverloadCandidate()); 2863 OverloadCandidate& Candidate = CandidateSet.back(); 2864 Candidate.FoundDecl = FoundDecl; 2865 Candidate.Function = Method; 2866 Candidate.IsSurrogate = false; 2867 Candidate.IgnoreObjectArgument = false; 2868 2869 unsigned NumArgsInProto = Proto->getNumArgs(); 2870 2871 // (C++ 13.3.2p2): A candidate function having fewer than m 2872 // parameters is viable only if it has an ellipsis in its parameter 2873 // list (8.3.5). 2874 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 2875 Candidate.Viable = false; 2876 Candidate.FailureKind = ovl_fail_too_many_arguments; 2877 return; 2878 } 2879 2880 // (C++ 13.3.2p2): A candidate function having more than m parameters 2881 // is viable only if the (m+1)st parameter has a default argument 2882 // (8.3.6). For the purposes of overload resolution, the 2883 // parameter list is truncated on the right, so that there are 2884 // exactly m parameters. 2885 unsigned MinRequiredArgs = Method->getMinRequiredArguments(); 2886 if (NumArgs < MinRequiredArgs) { 2887 // Not enough arguments. 2888 Candidate.Viable = false; 2889 Candidate.FailureKind = ovl_fail_too_few_arguments; 2890 return; 2891 } 2892 2893 Candidate.Viable = true; 2894 Candidate.Conversions.resize(NumArgs + 1); 2895 2896 if (Method->isStatic() || ObjectType.isNull()) 2897 // The implicit object argument is ignored. 2898 Candidate.IgnoreObjectArgument = true; 2899 else { 2900 // Determine the implicit conversion sequence for the object 2901 // parameter. 2902 Candidate.Conversions[0] 2903 = TryObjectArgumentInitialization(ObjectType, Method, ActingContext); 2904 if (Candidate.Conversions[0].isBad()) { 2905 Candidate.Viable = false; 2906 Candidate.FailureKind = ovl_fail_bad_conversion; 2907 return; 2908 } 2909 } 2910 2911 // Determine the implicit conversion sequences for each of the 2912 // arguments. 2913 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2914 if (ArgIdx < NumArgsInProto) { 2915 // (C++ 13.3.2p3): for F to be a viable function, there shall 2916 // exist for each argument an implicit conversion sequence 2917 // (13.3.3.1) that converts that argument to the corresponding 2918 // parameter of F. 2919 QualType ParamType = Proto->getArgType(ArgIdx); 2920 Candidate.Conversions[ArgIdx + 1] 2921 = TryCopyInitialization(*this, Args[ArgIdx], ParamType, 2922 SuppressUserConversions, 2923 /*InOverloadResolution=*/true); 2924 if (Candidate.Conversions[ArgIdx + 1].isBad()) { 2925 Candidate.Viable = false; 2926 Candidate.FailureKind = ovl_fail_bad_conversion; 2927 break; 2928 } 2929 } else { 2930 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2931 // argument for which there is no corresponding parameter is 2932 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2933 Candidate.Conversions[ArgIdx + 1].setEllipsis(); 2934 } 2935 } 2936} 2937 2938/// \brief Add a C++ member function template as a candidate to the candidate 2939/// set, using template argument deduction to produce an appropriate member 2940/// function template specialization. 2941void 2942Sema::AddMethodTemplateCandidate(FunctionTemplateDecl *MethodTmpl, 2943 DeclAccessPair FoundDecl, 2944 CXXRecordDecl *ActingContext, 2945 const TemplateArgumentListInfo *ExplicitTemplateArgs, 2946 QualType ObjectType, 2947 Expr **Args, unsigned NumArgs, 2948 OverloadCandidateSet& CandidateSet, 2949 bool SuppressUserConversions) { 2950 if (!CandidateSet.isNewCandidate(MethodTmpl)) 2951 return; 2952 2953 // C++ [over.match.funcs]p7: 2954 // In each case where a candidate is a function template, candidate 2955 // function template specializations are generated using template argument 2956 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 2957 // candidate functions in the usual way.113) A given name can refer to one 2958 // or more function templates and also to a set of overloaded non-template 2959 // functions. In such a case, the candidate functions generated from each 2960 // function template are combined with the set of non-template candidate 2961 // functions. 2962 TemplateDeductionInfo Info(Context, CandidateSet.getLocation()); 2963 FunctionDecl *Specialization = 0; 2964 if (TemplateDeductionResult Result 2965 = DeduceTemplateArguments(MethodTmpl, ExplicitTemplateArgs, 2966 Args, NumArgs, Specialization, Info)) { 2967 // FIXME: Record what happened with template argument deduction, so 2968 // that we can give the user a beautiful diagnostic. 2969 (void)Result; 2970 return; 2971 } 2972 2973 // Add the function template specialization produced by template argument 2974 // deduction as a candidate. 2975 assert(Specialization && "Missing member function template specialization?"); 2976 assert(isa<CXXMethodDecl>(Specialization) && 2977 "Specialization is not a member function?"); 2978 AddMethodCandidate(cast<CXXMethodDecl>(Specialization), FoundDecl, 2979 ActingContext, ObjectType, Args, NumArgs, 2980 CandidateSet, SuppressUserConversions); 2981} 2982 2983/// \brief Add a C++ function template specialization as a candidate 2984/// in the candidate set, using template argument deduction to produce 2985/// an appropriate function template specialization. 2986void 2987Sema::AddTemplateOverloadCandidate(FunctionTemplateDecl *FunctionTemplate, 2988 DeclAccessPair FoundDecl, 2989 const TemplateArgumentListInfo *ExplicitTemplateArgs, 2990 Expr **Args, unsigned NumArgs, 2991 OverloadCandidateSet& CandidateSet, 2992 bool SuppressUserConversions) { 2993 if (!CandidateSet.isNewCandidate(FunctionTemplate)) 2994 return; 2995 2996 // C++ [over.match.funcs]p7: 2997 // In each case where a candidate is a function template, candidate 2998 // function template specializations are generated using template argument 2999 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 3000 // candidate functions in the usual way.113) A given name can refer to one 3001 // or more function templates and also to a set of overloaded non-template 3002 // functions. In such a case, the candidate functions generated from each 3003 // function template are combined with the set of non-template candidate 3004 // functions. 3005 TemplateDeductionInfo Info(Context, CandidateSet.getLocation()); 3006 FunctionDecl *Specialization = 0; 3007 if (TemplateDeductionResult Result 3008 = DeduceTemplateArguments(FunctionTemplate, ExplicitTemplateArgs, 3009 Args, NumArgs, Specialization, Info)) { 3010 CandidateSet.push_back(OverloadCandidate()); 3011 OverloadCandidate &Candidate = CandidateSet.back(); 3012 Candidate.FoundDecl = FoundDecl; 3013 Candidate.Function = FunctionTemplate->getTemplatedDecl(); 3014 Candidate.Viable = false; 3015 Candidate.FailureKind = ovl_fail_bad_deduction; 3016 Candidate.IsSurrogate = false; 3017 Candidate.IgnoreObjectArgument = false; 3018 3019 // TODO: record more information about failed template arguments 3020 Candidate.DeductionFailure.Result = Result; 3021 Candidate.DeductionFailure.TemplateParameter = Info.Param.getOpaqueValue(); 3022 return; 3023 } 3024 3025 // Add the function template specialization produced by template argument 3026 // deduction as a candidate. 3027 assert(Specialization && "Missing function template specialization?"); 3028 AddOverloadCandidate(Specialization, FoundDecl, Args, NumArgs, CandidateSet, 3029 SuppressUserConversions); 3030} 3031 3032/// AddConversionCandidate - Add a C++ conversion function as a 3033/// candidate in the candidate set (C++ [over.match.conv], 3034/// C++ [over.match.copy]). From is the expression we're converting from, 3035/// and ToType is the type that we're eventually trying to convert to 3036/// (which may or may not be the same type as the type that the 3037/// conversion function produces). 3038void 3039Sema::AddConversionCandidate(CXXConversionDecl *Conversion, 3040 DeclAccessPair FoundDecl, 3041 CXXRecordDecl *ActingContext, 3042 Expr *From, QualType ToType, 3043 OverloadCandidateSet& CandidateSet) { 3044 assert(!Conversion->getDescribedFunctionTemplate() && 3045 "Conversion function templates use AddTemplateConversionCandidate"); 3046 3047 if (!CandidateSet.isNewCandidate(Conversion)) 3048 return; 3049 3050 // Overload resolution is always an unevaluated context. 3051 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 3052 3053 // Add this candidate 3054 CandidateSet.push_back(OverloadCandidate()); 3055 OverloadCandidate& Candidate = CandidateSet.back(); 3056 Candidate.FoundDecl = FoundDecl; 3057 Candidate.Function = Conversion; 3058 Candidate.IsSurrogate = false; 3059 Candidate.IgnoreObjectArgument = false; 3060 Candidate.FinalConversion.setAsIdentityConversion(); 3061 Candidate.FinalConversion.setFromType(Conversion->getConversionType()); 3062 Candidate.FinalConversion.setAllToTypes(ToType); 3063 3064 // Determine the implicit conversion sequence for the implicit 3065 // object parameter. 3066 Candidate.Viable = true; 3067 Candidate.Conversions.resize(1); 3068 Candidate.Conversions[0] 3069 = TryObjectArgumentInitialization(From->getType(), Conversion, 3070 ActingContext); 3071 // Conversion functions to a different type in the base class is visible in 3072 // the derived class. So, a derived to base conversion should not participate 3073 // in overload resolution. 3074 if (Candidate.Conversions[0].Standard.Second == ICK_Derived_To_Base) 3075 Candidate.Conversions[0].Standard.Second = ICK_Identity; 3076 if (Candidate.Conversions[0].isBad()) { 3077 Candidate.Viable = false; 3078 Candidate.FailureKind = ovl_fail_bad_conversion; 3079 return; 3080 } 3081 3082 // We won't go through a user-define type conversion function to convert a 3083 // derived to base as such conversions are given Conversion Rank. They only 3084 // go through a copy constructor. 13.3.3.1.2-p4 [over.ics.user] 3085 QualType FromCanon 3086 = Context.getCanonicalType(From->getType().getUnqualifiedType()); 3087 QualType ToCanon = Context.getCanonicalType(ToType).getUnqualifiedType(); 3088 if (FromCanon == ToCanon || IsDerivedFrom(FromCanon, ToCanon)) { 3089 Candidate.Viable = false; 3090 Candidate.FailureKind = ovl_fail_trivial_conversion; 3091 return; 3092 } 3093 3094 3095 // To determine what the conversion from the result of calling the 3096 // conversion function to the type we're eventually trying to 3097 // convert to (ToType), we need to synthesize a call to the 3098 // conversion function and attempt copy initialization from it. This 3099 // makes sure that we get the right semantics with respect to 3100 // lvalues/rvalues and the type. Fortunately, we can allocate this 3101 // call on the stack and we don't need its arguments to be 3102 // well-formed. 3103 DeclRefExpr ConversionRef(Conversion, Conversion->getType(), 3104 From->getLocStart()); 3105 ImplicitCastExpr ConversionFn(Context.getPointerType(Conversion->getType()), 3106 CastExpr::CK_FunctionToPointerDecay, 3107 &ConversionRef, false); 3108 3109 // Note that it is safe to allocate CallExpr on the stack here because 3110 // there are 0 arguments (i.e., nothing is allocated using ASTContext's 3111 // allocator). 3112 CallExpr Call(Context, &ConversionFn, 0, 0, 3113 Conversion->getConversionType().getNonReferenceType(), 3114 From->getLocStart()); 3115 ImplicitConversionSequence ICS = 3116 TryCopyInitialization(*this, &Call, ToType, 3117 /*SuppressUserConversions=*/true, 3118 /*InOverloadResolution=*/false); 3119 3120 switch (ICS.getKind()) { 3121 case ImplicitConversionSequence::StandardConversion: 3122 Candidate.FinalConversion = ICS.Standard; 3123 3124 // C++ [over.ics.user]p3: 3125 // If the user-defined conversion is specified by a specialization of a 3126 // conversion function template, the second standard conversion sequence 3127 // shall have exact match rank. 3128 if (Conversion->getPrimaryTemplate() && 3129 GetConversionRank(ICS.Standard.Second) != ICR_Exact_Match) { 3130 Candidate.Viable = false; 3131 Candidate.FailureKind = ovl_fail_final_conversion_not_exact; 3132 } 3133 3134 break; 3135 3136 case ImplicitConversionSequence::BadConversion: 3137 Candidate.Viable = false; 3138 Candidate.FailureKind = ovl_fail_bad_final_conversion; 3139 break; 3140 3141 default: 3142 assert(false && 3143 "Can only end up with a standard conversion sequence or failure"); 3144 } 3145} 3146 3147/// \brief Adds a conversion function template specialization 3148/// candidate to the overload set, using template argument deduction 3149/// to deduce the template arguments of the conversion function 3150/// template from the type that we are converting to (C++ 3151/// [temp.deduct.conv]). 3152void 3153Sema::AddTemplateConversionCandidate(FunctionTemplateDecl *FunctionTemplate, 3154 DeclAccessPair FoundDecl, 3155 CXXRecordDecl *ActingDC, 3156 Expr *From, QualType ToType, 3157 OverloadCandidateSet &CandidateSet) { 3158 assert(isa<CXXConversionDecl>(FunctionTemplate->getTemplatedDecl()) && 3159 "Only conversion function templates permitted here"); 3160 3161 if (!CandidateSet.isNewCandidate(FunctionTemplate)) 3162 return; 3163 3164 TemplateDeductionInfo Info(Context, CandidateSet.getLocation()); 3165 CXXConversionDecl *Specialization = 0; 3166 if (TemplateDeductionResult Result 3167 = DeduceTemplateArguments(FunctionTemplate, ToType, 3168 Specialization, Info)) { 3169 // FIXME: Record what happened with template argument deduction, so 3170 // that we can give the user a beautiful diagnostic. 3171 (void)Result; 3172 return; 3173 } 3174 3175 // Add the conversion function template specialization produced by 3176 // template argument deduction as a candidate. 3177 assert(Specialization && "Missing function template specialization?"); 3178 AddConversionCandidate(Specialization, FoundDecl, ActingDC, From, ToType, 3179 CandidateSet); 3180} 3181 3182/// AddSurrogateCandidate - Adds a "surrogate" candidate function that 3183/// converts the given @c Object to a function pointer via the 3184/// conversion function @c Conversion, and then attempts to call it 3185/// with the given arguments (C++ [over.call.object]p2-4). Proto is 3186/// the type of function that we'll eventually be calling. 3187void Sema::AddSurrogateCandidate(CXXConversionDecl *Conversion, 3188 DeclAccessPair FoundDecl, 3189 CXXRecordDecl *ActingContext, 3190 const FunctionProtoType *Proto, 3191 QualType ObjectType, 3192 Expr **Args, unsigned NumArgs, 3193 OverloadCandidateSet& CandidateSet) { 3194 if (!CandidateSet.isNewCandidate(Conversion)) 3195 return; 3196 3197 // Overload resolution is always an unevaluated context. 3198 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 3199 3200 CandidateSet.push_back(OverloadCandidate()); 3201 OverloadCandidate& Candidate = CandidateSet.back(); 3202 Candidate.FoundDecl = FoundDecl; 3203 Candidate.Function = 0; 3204 Candidate.Surrogate = Conversion; 3205 Candidate.Viable = true; 3206 Candidate.IsSurrogate = true; 3207 Candidate.IgnoreObjectArgument = false; 3208 Candidate.Conversions.resize(NumArgs + 1); 3209 3210 // Determine the implicit conversion sequence for the implicit 3211 // object parameter. 3212 ImplicitConversionSequence ObjectInit 3213 = TryObjectArgumentInitialization(ObjectType, Conversion, ActingContext); 3214 if (ObjectInit.isBad()) { 3215 Candidate.Viable = false; 3216 Candidate.FailureKind = ovl_fail_bad_conversion; 3217 Candidate.Conversions[0] = ObjectInit; 3218 return; 3219 } 3220 3221 // The first conversion is actually a user-defined conversion whose 3222 // first conversion is ObjectInit's standard conversion (which is 3223 // effectively a reference binding). Record it as such. 3224 Candidate.Conversions[0].setUserDefined(); 3225 Candidate.Conversions[0].UserDefined.Before = ObjectInit.Standard; 3226 Candidate.Conversions[0].UserDefined.EllipsisConversion = false; 3227 Candidate.Conversions[0].UserDefined.ConversionFunction = Conversion; 3228 Candidate.Conversions[0].UserDefined.After 3229 = Candidate.Conversions[0].UserDefined.Before; 3230 Candidate.Conversions[0].UserDefined.After.setAsIdentityConversion(); 3231 3232 // Find the 3233 unsigned NumArgsInProto = Proto->getNumArgs(); 3234 3235 // (C++ 13.3.2p2): A candidate function having fewer than m 3236 // parameters is viable only if it has an ellipsis in its parameter 3237 // list (8.3.5). 3238 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 3239 Candidate.Viable = false; 3240 Candidate.FailureKind = ovl_fail_too_many_arguments; 3241 return; 3242 } 3243 3244 // Function types don't have any default arguments, so just check if 3245 // we have enough arguments. 3246 if (NumArgs < NumArgsInProto) { 3247 // Not enough arguments. 3248 Candidate.Viable = false; 3249 Candidate.FailureKind = ovl_fail_too_few_arguments; 3250 return; 3251 } 3252 3253 // Determine the implicit conversion sequences for each of the 3254 // arguments. 3255 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 3256 if (ArgIdx < NumArgsInProto) { 3257 // (C++ 13.3.2p3): for F to be a viable function, there shall 3258 // exist for each argument an implicit conversion sequence 3259 // (13.3.3.1) that converts that argument to the corresponding 3260 // parameter of F. 3261 QualType ParamType = Proto->getArgType(ArgIdx); 3262 Candidate.Conversions[ArgIdx + 1] 3263 = TryCopyInitialization(*this, Args[ArgIdx], ParamType, 3264 /*SuppressUserConversions=*/false, 3265 /*InOverloadResolution=*/false); 3266 if (Candidate.Conversions[ArgIdx + 1].isBad()) { 3267 Candidate.Viable = false; 3268 Candidate.FailureKind = ovl_fail_bad_conversion; 3269 break; 3270 } 3271 } else { 3272 // (C++ 13.3.2p2): For the purposes of overload resolution, any 3273 // argument for which there is no corresponding parameter is 3274 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 3275 Candidate.Conversions[ArgIdx + 1].setEllipsis(); 3276 } 3277 } 3278} 3279 3280// FIXME: This will eventually be removed, once we've migrated all of the 3281// operator overloading logic over to the scheme used by binary operators, which 3282// works for template instantiation. 3283void Sema::AddOperatorCandidates(OverloadedOperatorKind Op, Scope *S, 3284 SourceLocation OpLoc, 3285 Expr **Args, unsigned NumArgs, 3286 OverloadCandidateSet& CandidateSet, 3287 SourceRange OpRange) { 3288 UnresolvedSet<16> Fns; 3289 3290 QualType T1 = Args[0]->getType(); 3291 QualType T2; 3292 if (NumArgs > 1) 3293 T2 = Args[1]->getType(); 3294 3295 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 3296 if (S) 3297 LookupOverloadedOperatorName(Op, S, T1, T2, Fns); 3298 AddFunctionCandidates(Fns, Args, NumArgs, CandidateSet, false); 3299 AddArgumentDependentLookupCandidates(OpName, false, Args, NumArgs, 0, 3300 CandidateSet); 3301 AddMemberOperatorCandidates(Op, OpLoc, Args, NumArgs, CandidateSet, OpRange); 3302 AddBuiltinOperatorCandidates(Op, OpLoc, Args, NumArgs, CandidateSet); 3303} 3304 3305/// \brief Add overload candidates for overloaded operators that are 3306/// member functions. 3307/// 3308/// Add the overloaded operator candidates that are member functions 3309/// for the operator Op that was used in an operator expression such 3310/// as "x Op y". , Args/NumArgs provides the operator arguments, and 3311/// CandidateSet will store the added overload candidates. (C++ 3312/// [over.match.oper]). 3313void Sema::AddMemberOperatorCandidates(OverloadedOperatorKind Op, 3314 SourceLocation OpLoc, 3315 Expr **Args, unsigned NumArgs, 3316 OverloadCandidateSet& CandidateSet, 3317 SourceRange OpRange) { 3318 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 3319 3320 // C++ [over.match.oper]p3: 3321 // For a unary operator @ with an operand of a type whose 3322 // cv-unqualified version is T1, and for a binary operator @ with 3323 // a left operand of a type whose cv-unqualified version is T1 and 3324 // a right operand of a type whose cv-unqualified version is T2, 3325 // three sets of candidate functions, designated member 3326 // candidates, non-member candidates and built-in candidates, are 3327 // constructed as follows: 3328 QualType T1 = Args[0]->getType(); 3329 QualType T2; 3330 if (NumArgs > 1) 3331 T2 = Args[1]->getType(); 3332 3333 // -- If T1 is a class type, the set of member candidates is the 3334 // result of the qualified lookup of T1::operator@ 3335 // (13.3.1.1.1); otherwise, the set of member candidates is 3336 // empty. 3337 if (const RecordType *T1Rec = T1->getAs<RecordType>()) { 3338 // Complete the type if it can be completed. Otherwise, we're done. 3339 if (RequireCompleteType(OpLoc, T1, PDiag())) 3340 return; 3341 3342 LookupResult Operators(*this, OpName, OpLoc, LookupOrdinaryName); 3343 LookupQualifiedName(Operators, T1Rec->getDecl()); 3344 Operators.suppressDiagnostics(); 3345 3346 for (LookupResult::iterator Oper = Operators.begin(), 3347 OperEnd = Operators.end(); 3348 Oper != OperEnd; 3349 ++Oper) 3350 AddMethodCandidate(Oper.getPair(), Args[0]->getType(), 3351 Args + 1, NumArgs - 1, CandidateSet, 3352 /* SuppressUserConversions = */ false); 3353 } 3354} 3355 3356/// AddBuiltinCandidate - Add a candidate for a built-in 3357/// operator. ResultTy and ParamTys are the result and parameter types 3358/// of the built-in candidate, respectively. Args and NumArgs are the 3359/// arguments being passed to the candidate. IsAssignmentOperator 3360/// should be true when this built-in candidate is an assignment 3361/// operator. NumContextualBoolArguments is the number of arguments 3362/// (at the beginning of the argument list) that will be contextually 3363/// converted to bool. 3364void Sema::AddBuiltinCandidate(QualType ResultTy, QualType *ParamTys, 3365 Expr **Args, unsigned NumArgs, 3366 OverloadCandidateSet& CandidateSet, 3367 bool IsAssignmentOperator, 3368 unsigned NumContextualBoolArguments) { 3369 // Overload resolution is always an unevaluated context. 3370 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 3371 3372 // Add this candidate 3373 CandidateSet.push_back(OverloadCandidate()); 3374 OverloadCandidate& Candidate = CandidateSet.back(); 3375 Candidate.FoundDecl = DeclAccessPair::make(0, AS_none); 3376 Candidate.Function = 0; 3377 Candidate.IsSurrogate = false; 3378 Candidate.IgnoreObjectArgument = false; 3379 Candidate.BuiltinTypes.ResultTy = ResultTy; 3380 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 3381 Candidate.BuiltinTypes.ParamTypes[ArgIdx] = ParamTys[ArgIdx]; 3382 3383 // Determine the implicit conversion sequences for each of the 3384 // arguments. 3385 Candidate.Viable = true; 3386 Candidate.Conversions.resize(NumArgs); 3387 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 3388 // C++ [over.match.oper]p4: 3389 // For the built-in assignment operators, conversions of the 3390 // left operand are restricted as follows: 3391 // -- no temporaries are introduced to hold the left operand, and 3392 // -- no user-defined conversions are applied to the left 3393 // operand to achieve a type match with the left-most 3394 // parameter of a built-in candidate. 3395 // 3396 // We block these conversions by turning off user-defined 3397 // conversions, since that is the only way that initialization of 3398 // a reference to a non-class type can occur from something that 3399 // is not of the same type. 3400 if (ArgIdx < NumContextualBoolArguments) { 3401 assert(ParamTys[ArgIdx] == Context.BoolTy && 3402 "Contextual conversion to bool requires bool type"); 3403 Candidate.Conversions[ArgIdx] = TryContextuallyConvertToBool(Args[ArgIdx]); 3404 } else { 3405 Candidate.Conversions[ArgIdx] 3406 = TryCopyInitialization(*this, Args[ArgIdx], ParamTys[ArgIdx], 3407 ArgIdx == 0 && IsAssignmentOperator, 3408 /*InOverloadResolution=*/false); 3409 } 3410 if (Candidate.Conversions[ArgIdx].isBad()) { 3411 Candidate.Viable = false; 3412 Candidate.FailureKind = ovl_fail_bad_conversion; 3413 break; 3414 } 3415 } 3416} 3417 3418/// BuiltinCandidateTypeSet - A set of types that will be used for the 3419/// candidate operator functions for built-in operators (C++ 3420/// [over.built]). The types are separated into pointer types and 3421/// enumeration types. 3422class BuiltinCandidateTypeSet { 3423 /// TypeSet - A set of types. 3424 typedef llvm::SmallPtrSet<QualType, 8> TypeSet; 3425 3426 /// PointerTypes - The set of pointer types that will be used in the 3427 /// built-in candidates. 3428 TypeSet PointerTypes; 3429 3430 /// MemberPointerTypes - The set of member pointer types that will be 3431 /// used in the built-in candidates. 3432 TypeSet MemberPointerTypes; 3433 3434 /// EnumerationTypes - The set of enumeration types that will be 3435 /// used in the built-in candidates. 3436 TypeSet EnumerationTypes; 3437 3438 /// Sema - The semantic analysis instance where we are building the 3439 /// candidate type set. 3440 Sema &SemaRef; 3441 3442 /// Context - The AST context in which we will build the type sets. 3443 ASTContext &Context; 3444 3445 bool AddPointerWithMoreQualifiedTypeVariants(QualType Ty, 3446 const Qualifiers &VisibleQuals); 3447 bool AddMemberPointerWithMoreQualifiedTypeVariants(QualType Ty); 3448 3449public: 3450 /// iterator - Iterates through the types that are part of the set. 3451 typedef TypeSet::iterator iterator; 3452 3453 BuiltinCandidateTypeSet(Sema &SemaRef) 3454 : SemaRef(SemaRef), Context(SemaRef.Context) { } 3455 3456 void AddTypesConvertedFrom(QualType Ty, 3457 SourceLocation Loc, 3458 bool AllowUserConversions, 3459 bool AllowExplicitConversions, 3460 const Qualifiers &VisibleTypeConversionsQuals); 3461 3462 /// pointer_begin - First pointer type found; 3463 iterator pointer_begin() { return PointerTypes.begin(); } 3464 3465 /// pointer_end - Past the last pointer type found; 3466 iterator pointer_end() { return PointerTypes.end(); } 3467 3468 /// member_pointer_begin - First member pointer type found; 3469 iterator member_pointer_begin() { return MemberPointerTypes.begin(); } 3470 3471 /// member_pointer_end - Past the last member pointer type found; 3472 iterator member_pointer_end() { return MemberPointerTypes.end(); } 3473 3474 /// enumeration_begin - First enumeration type found; 3475 iterator enumeration_begin() { return EnumerationTypes.begin(); } 3476 3477 /// enumeration_end - Past the last enumeration type found; 3478 iterator enumeration_end() { return EnumerationTypes.end(); } 3479}; 3480 3481/// AddPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty to 3482/// the set of pointer types along with any more-qualified variants of 3483/// that type. For example, if @p Ty is "int const *", this routine 3484/// will add "int const *", "int const volatile *", "int const 3485/// restrict *", and "int const volatile restrict *" to the set of 3486/// pointer types. Returns true if the add of @p Ty itself succeeded, 3487/// false otherwise. 3488/// 3489/// FIXME: what to do about extended qualifiers? 3490bool 3491BuiltinCandidateTypeSet::AddPointerWithMoreQualifiedTypeVariants(QualType Ty, 3492 const Qualifiers &VisibleQuals) { 3493 3494 // Insert this type. 3495 if (!PointerTypes.insert(Ty)) 3496 return false; 3497 3498 const PointerType *PointerTy = Ty->getAs<PointerType>(); 3499 assert(PointerTy && "type was not a pointer type!"); 3500 3501 QualType PointeeTy = PointerTy->getPointeeType(); 3502 // Don't add qualified variants of arrays. For one, they're not allowed 3503 // (the qualifier would sink to the element type), and for another, the 3504 // only overload situation where it matters is subscript or pointer +- int, 3505 // and those shouldn't have qualifier variants anyway. 3506 if (PointeeTy->isArrayType()) 3507 return true; 3508 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 3509 if (const ConstantArrayType *Array =Context.getAsConstantArrayType(PointeeTy)) 3510 BaseCVR = Array->getElementType().getCVRQualifiers(); 3511 bool hasVolatile = VisibleQuals.hasVolatile(); 3512 bool hasRestrict = VisibleQuals.hasRestrict(); 3513 3514 // Iterate through all strict supersets of BaseCVR. 3515 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 3516 if ((CVR | BaseCVR) != CVR) continue; 3517 // Skip over Volatile/Restrict if no Volatile/Restrict found anywhere 3518 // in the types. 3519 if ((CVR & Qualifiers::Volatile) && !hasVolatile) continue; 3520 if ((CVR & Qualifiers::Restrict) && !hasRestrict) continue; 3521 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 3522 PointerTypes.insert(Context.getPointerType(QPointeeTy)); 3523 } 3524 3525 return true; 3526} 3527 3528/// AddMemberPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty 3529/// to the set of pointer types along with any more-qualified variants of 3530/// that type. For example, if @p Ty is "int const *", this routine 3531/// will add "int const *", "int const volatile *", "int const 3532/// restrict *", and "int const volatile restrict *" to the set of 3533/// pointer types. Returns true if the add of @p Ty itself succeeded, 3534/// false otherwise. 3535/// 3536/// FIXME: what to do about extended qualifiers? 3537bool 3538BuiltinCandidateTypeSet::AddMemberPointerWithMoreQualifiedTypeVariants( 3539 QualType Ty) { 3540 // Insert this type. 3541 if (!MemberPointerTypes.insert(Ty)) 3542 return false; 3543 3544 const MemberPointerType *PointerTy = Ty->getAs<MemberPointerType>(); 3545 assert(PointerTy && "type was not a member pointer type!"); 3546 3547 QualType PointeeTy = PointerTy->getPointeeType(); 3548 // Don't add qualified variants of arrays. For one, they're not allowed 3549 // (the qualifier would sink to the element type), and for another, the 3550 // only overload situation where it matters is subscript or pointer +- int, 3551 // and those shouldn't have qualifier variants anyway. 3552 if (PointeeTy->isArrayType()) 3553 return true; 3554 const Type *ClassTy = PointerTy->getClass(); 3555 3556 // Iterate through all strict supersets of the pointee type's CVR 3557 // qualifiers. 3558 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 3559 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 3560 if ((CVR | BaseCVR) != CVR) continue; 3561 3562 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 3563 MemberPointerTypes.insert(Context.getMemberPointerType(QPointeeTy, ClassTy)); 3564 } 3565 3566 return true; 3567} 3568 3569/// AddTypesConvertedFrom - Add each of the types to which the type @p 3570/// Ty can be implicit converted to the given set of @p Types. We're 3571/// primarily interested in pointer types and enumeration types. We also 3572/// take member pointer types, for the conditional operator. 3573/// AllowUserConversions is true if we should look at the conversion 3574/// functions of a class type, and AllowExplicitConversions if we 3575/// should also include the explicit conversion functions of a class 3576/// type. 3577void 3578BuiltinCandidateTypeSet::AddTypesConvertedFrom(QualType Ty, 3579 SourceLocation Loc, 3580 bool AllowUserConversions, 3581 bool AllowExplicitConversions, 3582 const Qualifiers &VisibleQuals) { 3583 // Only deal with canonical types. 3584 Ty = Context.getCanonicalType(Ty); 3585 3586 // Look through reference types; they aren't part of the type of an 3587 // expression for the purposes of conversions. 3588 if (const ReferenceType *RefTy = Ty->getAs<ReferenceType>()) 3589 Ty = RefTy->getPointeeType(); 3590 3591 // We don't care about qualifiers on the type. 3592 Ty = Ty.getLocalUnqualifiedType(); 3593 3594 // If we're dealing with an array type, decay to the pointer. 3595 if (Ty->isArrayType()) 3596 Ty = SemaRef.Context.getArrayDecayedType(Ty); 3597 3598 if (const PointerType *PointerTy = Ty->getAs<PointerType>()) { 3599 QualType PointeeTy = PointerTy->getPointeeType(); 3600 3601 // Insert our type, and its more-qualified variants, into the set 3602 // of types. 3603 if (!AddPointerWithMoreQualifiedTypeVariants(Ty, VisibleQuals)) 3604 return; 3605 } else if (Ty->isMemberPointerType()) { 3606 // Member pointers are far easier, since the pointee can't be converted. 3607 if (!AddMemberPointerWithMoreQualifiedTypeVariants(Ty)) 3608 return; 3609 } else if (Ty->isEnumeralType()) { 3610 EnumerationTypes.insert(Ty); 3611 } else if (AllowUserConversions) { 3612 if (const RecordType *TyRec = Ty->getAs<RecordType>()) { 3613 if (SemaRef.RequireCompleteType(Loc, Ty, 0)) { 3614 // No conversion functions in incomplete types. 3615 return; 3616 } 3617 3618 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 3619 const UnresolvedSetImpl *Conversions 3620 = ClassDecl->getVisibleConversionFunctions(); 3621 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 3622 E = Conversions->end(); I != E; ++I) { 3623 NamedDecl *D = I.getDecl(); 3624 if (isa<UsingShadowDecl>(D)) 3625 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 3626 3627 // Skip conversion function templates; they don't tell us anything 3628 // about which builtin types we can convert to. 3629 if (isa<FunctionTemplateDecl>(D)) 3630 continue; 3631 3632 CXXConversionDecl *Conv = cast<CXXConversionDecl>(D); 3633 if (AllowExplicitConversions || !Conv->isExplicit()) { 3634 AddTypesConvertedFrom(Conv->getConversionType(), Loc, false, false, 3635 VisibleQuals); 3636 } 3637 } 3638 } 3639 } 3640} 3641 3642/// \brief Helper function for AddBuiltinOperatorCandidates() that adds 3643/// the volatile- and non-volatile-qualified assignment operators for the 3644/// given type to the candidate set. 3645static void AddBuiltinAssignmentOperatorCandidates(Sema &S, 3646 QualType T, 3647 Expr **Args, 3648 unsigned NumArgs, 3649 OverloadCandidateSet &CandidateSet) { 3650 QualType ParamTypes[2]; 3651 3652 // T& operator=(T&, T) 3653 ParamTypes[0] = S.Context.getLValueReferenceType(T); 3654 ParamTypes[1] = T; 3655 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3656 /*IsAssignmentOperator=*/true); 3657 3658 if (!S.Context.getCanonicalType(T).isVolatileQualified()) { 3659 // volatile T& operator=(volatile T&, T) 3660 ParamTypes[0] 3661 = S.Context.getLValueReferenceType(S.Context.getVolatileType(T)); 3662 ParamTypes[1] = T; 3663 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3664 /*IsAssignmentOperator=*/true); 3665 } 3666} 3667 3668/// CollectVRQualifiers - This routine returns Volatile/Restrict qualifiers, 3669/// if any, found in visible type conversion functions found in ArgExpr's type. 3670static Qualifiers CollectVRQualifiers(ASTContext &Context, Expr* ArgExpr) { 3671 Qualifiers VRQuals; 3672 const RecordType *TyRec; 3673 if (const MemberPointerType *RHSMPType = 3674 ArgExpr->getType()->getAs<MemberPointerType>()) 3675 TyRec = cast<RecordType>(RHSMPType->getClass()); 3676 else 3677 TyRec = ArgExpr->getType()->getAs<RecordType>(); 3678 if (!TyRec) { 3679 // Just to be safe, assume the worst case. 3680 VRQuals.addVolatile(); 3681 VRQuals.addRestrict(); 3682 return VRQuals; 3683 } 3684 3685 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 3686 if (!ClassDecl->hasDefinition()) 3687 return VRQuals; 3688 3689 const UnresolvedSetImpl *Conversions = 3690 ClassDecl->getVisibleConversionFunctions(); 3691 3692 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 3693 E = Conversions->end(); I != E; ++I) { 3694 NamedDecl *D = I.getDecl(); 3695 if (isa<UsingShadowDecl>(D)) 3696 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 3697 if (CXXConversionDecl *Conv = dyn_cast<CXXConversionDecl>(D)) { 3698 QualType CanTy = Context.getCanonicalType(Conv->getConversionType()); 3699 if (const ReferenceType *ResTypeRef = CanTy->getAs<ReferenceType>()) 3700 CanTy = ResTypeRef->getPointeeType(); 3701 // Need to go down the pointer/mempointer chain and add qualifiers 3702 // as see them. 3703 bool done = false; 3704 while (!done) { 3705 if (const PointerType *ResTypePtr = CanTy->getAs<PointerType>()) 3706 CanTy = ResTypePtr->getPointeeType(); 3707 else if (const MemberPointerType *ResTypeMPtr = 3708 CanTy->getAs<MemberPointerType>()) 3709 CanTy = ResTypeMPtr->getPointeeType(); 3710 else 3711 done = true; 3712 if (CanTy.isVolatileQualified()) 3713 VRQuals.addVolatile(); 3714 if (CanTy.isRestrictQualified()) 3715 VRQuals.addRestrict(); 3716 if (VRQuals.hasRestrict() && VRQuals.hasVolatile()) 3717 return VRQuals; 3718 } 3719 } 3720 } 3721 return VRQuals; 3722} 3723 3724/// AddBuiltinOperatorCandidates - Add the appropriate built-in 3725/// operator overloads to the candidate set (C++ [over.built]), based 3726/// on the operator @p Op and the arguments given. For example, if the 3727/// operator is a binary '+', this routine might add "int 3728/// operator+(int, int)" to cover integer addition. 3729void 3730Sema::AddBuiltinOperatorCandidates(OverloadedOperatorKind Op, 3731 SourceLocation OpLoc, 3732 Expr **Args, unsigned NumArgs, 3733 OverloadCandidateSet& CandidateSet) { 3734 // The set of "promoted arithmetic types", which are the arithmetic 3735 // types are that preserved by promotion (C++ [over.built]p2). Note 3736 // that the first few of these types are the promoted integral 3737 // types; these types need to be first. 3738 // FIXME: What about complex? 3739 const unsigned FirstIntegralType = 0; 3740 const unsigned LastIntegralType = 13; 3741 const unsigned FirstPromotedIntegralType = 7, 3742 LastPromotedIntegralType = 13; 3743 const unsigned FirstPromotedArithmeticType = 7, 3744 LastPromotedArithmeticType = 16; 3745 const unsigned NumArithmeticTypes = 16; 3746 QualType ArithmeticTypes[NumArithmeticTypes] = { 3747 Context.BoolTy, Context.CharTy, Context.WCharTy, 3748// FIXME: Context.Char16Ty, Context.Char32Ty, 3749 Context.SignedCharTy, Context.ShortTy, 3750 Context.UnsignedCharTy, Context.UnsignedShortTy, 3751 Context.IntTy, Context.LongTy, Context.LongLongTy, 3752 Context.UnsignedIntTy, Context.UnsignedLongTy, Context.UnsignedLongLongTy, 3753 Context.FloatTy, Context.DoubleTy, Context.LongDoubleTy 3754 }; 3755 assert(ArithmeticTypes[FirstPromotedIntegralType] == Context.IntTy && 3756 "Invalid first promoted integral type"); 3757 assert(ArithmeticTypes[LastPromotedIntegralType - 1] 3758 == Context.UnsignedLongLongTy && 3759 "Invalid last promoted integral type"); 3760 assert(ArithmeticTypes[FirstPromotedArithmeticType] == Context.IntTy && 3761 "Invalid first promoted arithmetic type"); 3762 assert(ArithmeticTypes[LastPromotedArithmeticType - 1] 3763 == Context.LongDoubleTy && 3764 "Invalid last promoted arithmetic type"); 3765 3766 // Find all of the types that the arguments can convert to, but only 3767 // if the operator we're looking at has built-in operator candidates 3768 // that make use of these types. 3769 Qualifiers VisibleTypeConversionsQuals; 3770 VisibleTypeConversionsQuals.addConst(); 3771 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 3772 VisibleTypeConversionsQuals += CollectVRQualifiers(Context, Args[ArgIdx]); 3773 3774 BuiltinCandidateTypeSet CandidateTypes(*this); 3775 if (Op == OO_Less || Op == OO_Greater || Op == OO_LessEqual || 3776 Op == OO_GreaterEqual || Op == OO_EqualEqual || Op == OO_ExclaimEqual || 3777 Op == OO_Plus || (Op == OO_Minus && NumArgs == 2) || Op == OO_Equal || 3778 Op == OO_PlusEqual || Op == OO_MinusEqual || Op == OO_Subscript || 3779 Op == OO_ArrowStar || Op == OO_PlusPlus || Op == OO_MinusMinus || 3780 (Op == OO_Star && NumArgs == 1) || Op == OO_Conditional) { 3781 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 3782 CandidateTypes.AddTypesConvertedFrom(Args[ArgIdx]->getType(), 3783 OpLoc, 3784 true, 3785 (Op == OO_Exclaim || 3786 Op == OO_AmpAmp || 3787 Op == OO_PipePipe), 3788 VisibleTypeConversionsQuals); 3789 } 3790 3791 bool isComparison = false; 3792 switch (Op) { 3793 case OO_None: 3794 case NUM_OVERLOADED_OPERATORS: 3795 assert(false && "Expected an overloaded operator"); 3796 break; 3797 3798 case OO_Star: // '*' is either unary or binary 3799 if (NumArgs == 1) 3800 goto UnaryStar; 3801 else 3802 goto BinaryStar; 3803 break; 3804 3805 case OO_Plus: // '+' is either unary or binary 3806 if (NumArgs == 1) 3807 goto UnaryPlus; 3808 else 3809 goto BinaryPlus; 3810 break; 3811 3812 case OO_Minus: // '-' is either unary or binary 3813 if (NumArgs == 1) 3814 goto UnaryMinus; 3815 else 3816 goto BinaryMinus; 3817 break; 3818 3819 case OO_Amp: // '&' is either unary or binary 3820 if (NumArgs == 1) 3821 goto UnaryAmp; 3822 else 3823 goto BinaryAmp; 3824 3825 case OO_PlusPlus: 3826 case OO_MinusMinus: 3827 // C++ [over.built]p3: 3828 // 3829 // For every pair (T, VQ), where T is an arithmetic type, and VQ 3830 // is either volatile or empty, there exist candidate operator 3831 // functions of the form 3832 // 3833 // VQ T& operator++(VQ T&); 3834 // T operator++(VQ T&, int); 3835 // 3836 // C++ [over.built]p4: 3837 // 3838 // For every pair (T, VQ), where T is an arithmetic type other 3839 // than bool, and VQ is either volatile or empty, there exist 3840 // candidate operator functions of the form 3841 // 3842 // VQ T& operator--(VQ T&); 3843 // T operator--(VQ T&, int); 3844 for (unsigned Arith = (Op == OO_PlusPlus? 0 : 1); 3845 Arith < NumArithmeticTypes; ++Arith) { 3846 QualType ArithTy = ArithmeticTypes[Arith]; 3847 QualType ParamTypes[2] 3848 = { Context.getLValueReferenceType(ArithTy), Context.IntTy }; 3849 3850 // Non-volatile version. 3851 if (NumArgs == 1) 3852 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3853 else 3854 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 3855 // heuristic to reduce number of builtin candidates in the set. 3856 // Add volatile version only if there are conversions to a volatile type. 3857 if (VisibleTypeConversionsQuals.hasVolatile()) { 3858 // Volatile version 3859 ParamTypes[0] 3860 = Context.getLValueReferenceType(Context.getVolatileType(ArithTy)); 3861 if (NumArgs == 1) 3862 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3863 else 3864 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 3865 } 3866 } 3867 3868 // C++ [over.built]p5: 3869 // 3870 // For every pair (T, VQ), where T is a cv-qualified or 3871 // cv-unqualified object type, and VQ is either volatile or 3872 // empty, there exist candidate operator functions of the form 3873 // 3874 // T*VQ& operator++(T*VQ&); 3875 // T*VQ& operator--(T*VQ&); 3876 // T* operator++(T*VQ&, int); 3877 // T* operator--(T*VQ&, int); 3878 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3879 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3880 // Skip pointer types that aren't pointers to object types. 3881 if (!(*Ptr)->getAs<PointerType>()->getPointeeType()->isObjectType()) 3882 continue; 3883 3884 QualType ParamTypes[2] = { 3885 Context.getLValueReferenceType(*Ptr), Context.IntTy 3886 }; 3887 3888 // Without volatile 3889 if (NumArgs == 1) 3890 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3891 else 3892 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3893 3894 if (!Context.getCanonicalType(*Ptr).isVolatileQualified() && 3895 VisibleTypeConversionsQuals.hasVolatile()) { 3896 // With volatile 3897 ParamTypes[0] 3898 = Context.getLValueReferenceType(Context.getVolatileType(*Ptr)); 3899 if (NumArgs == 1) 3900 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3901 else 3902 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3903 } 3904 } 3905 break; 3906 3907 UnaryStar: 3908 // C++ [over.built]p6: 3909 // For every cv-qualified or cv-unqualified object type T, there 3910 // exist candidate operator functions of the form 3911 // 3912 // T& operator*(T*); 3913 // 3914 // C++ [over.built]p7: 3915 // For every function type T, there exist candidate operator 3916 // functions of the form 3917 // T& operator*(T*); 3918 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3919 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3920 QualType ParamTy = *Ptr; 3921 QualType PointeeTy = ParamTy->getAs<PointerType>()->getPointeeType(); 3922 AddBuiltinCandidate(Context.getLValueReferenceType(PointeeTy), 3923 &ParamTy, Args, 1, CandidateSet); 3924 } 3925 break; 3926 3927 UnaryPlus: 3928 // C++ [over.built]p8: 3929 // For every type T, there exist candidate operator functions of 3930 // the form 3931 // 3932 // T* operator+(T*); 3933 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3934 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3935 QualType ParamTy = *Ptr; 3936 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet); 3937 } 3938 3939 // Fall through 3940 3941 UnaryMinus: 3942 // C++ [over.built]p9: 3943 // For every promoted arithmetic type T, there exist candidate 3944 // operator functions of the form 3945 // 3946 // T operator+(T); 3947 // T operator-(T); 3948 for (unsigned Arith = FirstPromotedArithmeticType; 3949 Arith < LastPromotedArithmeticType; ++Arith) { 3950 QualType ArithTy = ArithmeticTypes[Arith]; 3951 AddBuiltinCandidate(ArithTy, &ArithTy, Args, 1, CandidateSet); 3952 } 3953 break; 3954 3955 case OO_Tilde: 3956 // C++ [over.built]p10: 3957 // For every promoted integral type T, there exist candidate 3958 // operator functions of the form 3959 // 3960 // T operator~(T); 3961 for (unsigned Int = FirstPromotedIntegralType; 3962 Int < LastPromotedIntegralType; ++Int) { 3963 QualType IntTy = ArithmeticTypes[Int]; 3964 AddBuiltinCandidate(IntTy, &IntTy, Args, 1, CandidateSet); 3965 } 3966 break; 3967 3968 case OO_New: 3969 case OO_Delete: 3970 case OO_Array_New: 3971 case OO_Array_Delete: 3972 case OO_Call: 3973 assert(false && "Special operators don't use AddBuiltinOperatorCandidates"); 3974 break; 3975 3976 case OO_Comma: 3977 UnaryAmp: 3978 case OO_Arrow: 3979 // C++ [over.match.oper]p3: 3980 // -- For the operator ',', the unary operator '&', or the 3981 // operator '->', the built-in candidates set is empty. 3982 break; 3983 3984 case OO_EqualEqual: 3985 case OO_ExclaimEqual: 3986 // C++ [over.match.oper]p16: 3987 // For every pointer to member type T, there exist candidate operator 3988 // functions of the form 3989 // 3990 // bool operator==(T,T); 3991 // bool operator!=(T,T); 3992 for (BuiltinCandidateTypeSet::iterator 3993 MemPtr = CandidateTypes.member_pointer_begin(), 3994 MemPtrEnd = CandidateTypes.member_pointer_end(); 3995 MemPtr != MemPtrEnd; 3996 ++MemPtr) { 3997 QualType ParamTypes[2] = { *MemPtr, *MemPtr }; 3998 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 3999 } 4000 4001 // Fall through 4002 4003 case OO_Less: 4004 case OO_Greater: 4005 case OO_LessEqual: 4006 case OO_GreaterEqual: 4007 // C++ [over.built]p15: 4008 // 4009 // For every pointer or enumeration type T, there exist 4010 // candidate operator functions of the form 4011 // 4012 // bool operator<(T, T); 4013 // bool operator>(T, T); 4014 // bool operator<=(T, T); 4015 // bool operator>=(T, T); 4016 // bool operator==(T, T); 4017 // bool operator!=(T, T); 4018 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 4019 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4020 QualType ParamTypes[2] = { *Ptr, *Ptr }; 4021 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 4022 } 4023 for (BuiltinCandidateTypeSet::iterator Enum 4024 = CandidateTypes.enumeration_begin(); 4025 Enum != CandidateTypes.enumeration_end(); ++Enum) { 4026 QualType ParamTypes[2] = { *Enum, *Enum }; 4027 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 4028 } 4029 4030 // Fall through. 4031 isComparison = true; 4032 4033 BinaryPlus: 4034 BinaryMinus: 4035 if (!isComparison) { 4036 // We didn't fall through, so we must have OO_Plus or OO_Minus. 4037 4038 // C++ [over.built]p13: 4039 // 4040 // For every cv-qualified or cv-unqualified object type T 4041 // there exist candidate operator functions of the form 4042 // 4043 // T* operator+(T*, ptrdiff_t); 4044 // T& operator[](T*, ptrdiff_t); [BELOW] 4045 // T* operator-(T*, ptrdiff_t); 4046 // T* operator+(ptrdiff_t, T*); 4047 // T& operator[](ptrdiff_t, T*); [BELOW] 4048 // 4049 // C++ [over.built]p14: 4050 // 4051 // For every T, where T is a pointer to object type, there 4052 // exist candidate operator functions of the form 4053 // 4054 // ptrdiff_t operator-(T, T); 4055 for (BuiltinCandidateTypeSet::iterator Ptr 4056 = CandidateTypes.pointer_begin(); 4057 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4058 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 4059 4060 // operator+(T*, ptrdiff_t) or operator-(T*, ptrdiff_t) 4061 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 4062 4063 if (Op == OO_Plus) { 4064 // T* operator+(ptrdiff_t, T*); 4065 ParamTypes[0] = ParamTypes[1]; 4066 ParamTypes[1] = *Ptr; 4067 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 4068 } else { 4069 // ptrdiff_t operator-(T, T); 4070 ParamTypes[1] = *Ptr; 4071 AddBuiltinCandidate(Context.getPointerDiffType(), ParamTypes, 4072 Args, 2, CandidateSet); 4073 } 4074 } 4075 } 4076 // Fall through 4077 4078 case OO_Slash: 4079 BinaryStar: 4080 Conditional: 4081 // C++ [over.built]p12: 4082 // 4083 // For every pair of promoted arithmetic types L and R, there 4084 // exist candidate operator functions of the form 4085 // 4086 // LR operator*(L, R); 4087 // LR operator/(L, R); 4088 // LR operator+(L, R); 4089 // LR operator-(L, R); 4090 // bool operator<(L, R); 4091 // bool operator>(L, R); 4092 // bool operator<=(L, R); 4093 // bool operator>=(L, R); 4094 // bool operator==(L, R); 4095 // bool operator!=(L, R); 4096 // 4097 // where LR is the result of the usual arithmetic conversions 4098 // between types L and R. 4099 // 4100 // C++ [over.built]p24: 4101 // 4102 // For every pair of promoted arithmetic types L and R, there exist 4103 // candidate operator functions of the form 4104 // 4105 // LR operator?(bool, L, R); 4106 // 4107 // where LR is the result of the usual arithmetic conversions 4108 // between types L and R. 4109 // Our candidates ignore the first parameter. 4110 for (unsigned Left = FirstPromotedArithmeticType; 4111 Left < LastPromotedArithmeticType; ++Left) { 4112 for (unsigned Right = FirstPromotedArithmeticType; 4113 Right < LastPromotedArithmeticType; ++Right) { 4114 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 4115 QualType Result 4116 = isComparison 4117 ? Context.BoolTy 4118 : Context.UsualArithmeticConversionsType(LandR[0], LandR[1]); 4119 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 4120 } 4121 } 4122 break; 4123 4124 case OO_Percent: 4125 BinaryAmp: 4126 case OO_Caret: 4127 case OO_Pipe: 4128 case OO_LessLess: 4129 case OO_GreaterGreater: 4130 // C++ [over.built]p17: 4131 // 4132 // For every pair of promoted integral types L and R, there 4133 // exist candidate operator functions of the form 4134 // 4135 // LR operator%(L, R); 4136 // LR operator&(L, R); 4137 // LR operator^(L, R); 4138 // LR operator|(L, R); 4139 // L operator<<(L, R); 4140 // L operator>>(L, R); 4141 // 4142 // where LR is the result of the usual arithmetic conversions 4143 // between types L and R. 4144 for (unsigned Left = FirstPromotedIntegralType; 4145 Left < LastPromotedIntegralType; ++Left) { 4146 for (unsigned Right = FirstPromotedIntegralType; 4147 Right < LastPromotedIntegralType; ++Right) { 4148 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 4149 QualType Result = (Op == OO_LessLess || Op == OO_GreaterGreater) 4150 ? LandR[0] 4151 : Context.UsualArithmeticConversionsType(LandR[0], LandR[1]); 4152 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 4153 } 4154 } 4155 break; 4156 4157 case OO_Equal: 4158 // C++ [over.built]p20: 4159 // 4160 // For every pair (T, VQ), where T is an enumeration or 4161 // pointer to member type and VQ is either volatile or 4162 // empty, there exist candidate operator functions of the form 4163 // 4164 // VQ T& operator=(VQ T&, T); 4165 for (BuiltinCandidateTypeSet::iterator 4166 Enum = CandidateTypes.enumeration_begin(), 4167 EnumEnd = CandidateTypes.enumeration_end(); 4168 Enum != EnumEnd; ++Enum) 4169 AddBuiltinAssignmentOperatorCandidates(*this, *Enum, Args, 2, 4170 CandidateSet); 4171 for (BuiltinCandidateTypeSet::iterator 4172 MemPtr = CandidateTypes.member_pointer_begin(), 4173 MemPtrEnd = CandidateTypes.member_pointer_end(); 4174 MemPtr != MemPtrEnd; ++MemPtr) 4175 AddBuiltinAssignmentOperatorCandidates(*this, *MemPtr, Args, 2, 4176 CandidateSet); 4177 // Fall through. 4178 4179 case OO_PlusEqual: 4180 case OO_MinusEqual: 4181 // C++ [over.built]p19: 4182 // 4183 // For every pair (T, VQ), where T is any type and VQ is either 4184 // volatile or empty, there exist candidate operator functions 4185 // of the form 4186 // 4187 // T*VQ& operator=(T*VQ&, T*); 4188 // 4189 // C++ [over.built]p21: 4190 // 4191 // For every pair (T, VQ), where T is a cv-qualified or 4192 // cv-unqualified object type and VQ is either volatile or 4193 // empty, there exist candidate operator functions of the form 4194 // 4195 // T*VQ& operator+=(T*VQ&, ptrdiff_t); 4196 // T*VQ& operator-=(T*VQ&, ptrdiff_t); 4197 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 4198 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4199 QualType ParamTypes[2]; 4200 ParamTypes[1] = (Op == OO_Equal)? *Ptr : Context.getPointerDiffType(); 4201 4202 // non-volatile version 4203 ParamTypes[0] = Context.getLValueReferenceType(*Ptr); 4204 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4205 /*IsAssigmentOperator=*/Op == OO_Equal); 4206 4207 if (!Context.getCanonicalType(*Ptr).isVolatileQualified() && 4208 VisibleTypeConversionsQuals.hasVolatile()) { 4209 // volatile version 4210 ParamTypes[0] 4211 = Context.getLValueReferenceType(Context.getVolatileType(*Ptr)); 4212 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4213 /*IsAssigmentOperator=*/Op == OO_Equal); 4214 } 4215 } 4216 // Fall through. 4217 4218 case OO_StarEqual: 4219 case OO_SlashEqual: 4220 // C++ [over.built]p18: 4221 // 4222 // For every triple (L, VQ, R), where L is an arithmetic type, 4223 // VQ is either volatile or empty, and R is a promoted 4224 // arithmetic type, there exist candidate operator functions of 4225 // the form 4226 // 4227 // VQ L& operator=(VQ L&, R); 4228 // VQ L& operator*=(VQ L&, R); 4229 // VQ L& operator/=(VQ L&, R); 4230 // VQ L& operator+=(VQ L&, R); 4231 // VQ L& operator-=(VQ L&, R); 4232 for (unsigned Left = 0; Left < NumArithmeticTypes; ++Left) { 4233 for (unsigned Right = FirstPromotedArithmeticType; 4234 Right < LastPromotedArithmeticType; ++Right) { 4235 QualType ParamTypes[2]; 4236 ParamTypes[1] = ArithmeticTypes[Right]; 4237 4238 // Add this built-in operator as a candidate (VQ is empty). 4239 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 4240 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4241 /*IsAssigmentOperator=*/Op == OO_Equal); 4242 4243 // Add this built-in operator as a candidate (VQ is 'volatile'). 4244 if (VisibleTypeConversionsQuals.hasVolatile()) { 4245 ParamTypes[0] = Context.getVolatileType(ArithmeticTypes[Left]); 4246 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 4247 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4248 /*IsAssigmentOperator=*/Op == OO_Equal); 4249 } 4250 } 4251 } 4252 break; 4253 4254 case OO_PercentEqual: 4255 case OO_LessLessEqual: 4256 case OO_GreaterGreaterEqual: 4257 case OO_AmpEqual: 4258 case OO_CaretEqual: 4259 case OO_PipeEqual: 4260 // C++ [over.built]p22: 4261 // 4262 // For every triple (L, VQ, R), where L is an integral type, VQ 4263 // is either volatile or empty, and R is a promoted integral 4264 // type, there exist candidate operator functions of the form 4265 // 4266 // VQ L& operator%=(VQ L&, R); 4267 // VQ L& operator<<=(VQ L&, R); 4268 // VQ L& operator>>=(VQ L&, R); 4269 // VQ L& operator&=(VQ L&, R); 4270 // VQ L& operator^=(VQ L&, R); 4271 // VQ L& operator|=(VQ L&, R); 4272 for (unsigned Left = FirstIntegralType; Left < LastIntegralType; ++Left) { 4273 for (unsigned Right = FirstPromotedIntegralType; 4274 Right < LastPromotedIntegralType; ++Right) { 4275 QualType ParamTypes[2]; 4276 ParamTypes[1] = ArithmeticTypes[Right]; 4277 4278 // Add this built-in operator as a candidate (VQ is empty). 4279 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 4280 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 4281 if (VisibleTypeConversionsQuals.hasVolatile()) { 4282 // Add this built-in operator as a candidate (VQ is 'volatile'). 4283 ParamTypes[0] = ArithmeticTypes[Left]; 4284 ParamTypes[0] = Context.getVolatileType(ParamTypes[0]); 4285 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 4286 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 4287 } 4288 } 4289 } 4290 break; 4291 4292 case OO_Exclaim: { 4293 // C++ [over.operator]p23: 4294 // 4295 // There also exist candidate operator functions of the form 4296 // 4297 // bool operator!(bool); 4298 // bool operator&&(bool, bool); [BELOW] 4299 // bool operator||(bool, bool); [BELOW] 4300 QualType ParamTy = Context.BoolTy; 4301 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet, 4302 /*IsAssignmentOperator=*/false, 4303 /*NumContextualBoolArguments=*/1); 4304 break; 4305 } 4306 4307 case OO_AmpAmp: 4308 case OO_PipePipe: { 4309 // C++ [over.operator]p23: 4310 // 4311 // There also exist candidate operator functions of the form 4312 // 4313 // bool operator!(bool); [ABOVE] 4314 // bool operator&&(bool, bool); 4315 // bool operator||(bool, bool); 4316 QualType ParamTypes[2] = { Context.BoolTy, Context.BoolTy }; 4317 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet, 4318 /*IsAssignmentOperator=*/false, 4319 /*NumContextualBoolArguments=*/2); 4320 break; 4321 } 4322 4323 case OO_Subscript: 4324 // C++ [over.built]p13: 4325 // 4326 // For every cv-qualified or cv-unqualified object type T there 4327 // exist candidate operator functions of the form 4328 // 4329 // T* operator+(T*, ptrdiff_t); [ABOVE] 4330 // T& operator[](T*, ptrdiff_t); 4331 // T* operator-(T*, ptrdiff_t); [ABOVE] 4332 // T* operator+(ptrdiff_t, T*); [ABOVE] 4333 // T& operator[](ptrdiff_t, T*); 4334 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 4335 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4336 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 4337 QualType PointeeType = (*Ptr)->getAs<PointerType>()->getPointeeType(); 4338 QualType ResultTy = Context.getLValueReferenceType(PointeeType); 4339 4340 // T& operator[](T*, ptrdiff_t) 4341 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 4342 4343 // T& operator[](ptrdiff_t, T*); 4344 ParamTypes[0] = ParamTypes[1]; 4345 ParamTypes[1] = *Ptr; 4346 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 4347 } 4348 break; 4349 4350 case OO_ArrowStar: 4351 // C++ [over.built]p11: 4352 // For every quintuple (C1, C2, T, CV1, CV2), where C2 is a class type, 4353 // C1 is the same type as C2 or is a derived class of C2, T is an object 4354 // type or a function type, and CV1 and CV2 are cv-qualifier-seqs, 4355 // there exist candidate operator functions of the form 4356 // CV12 T& operator->*(CV1 C1*, CV2 T C2::*); 4357 // where CV12 is the union of CV1 and CV2. 4358 { 4359 for (BuiltinCandidateTypeSet::iterator Ptr = 4360 CandidateTypes.pointer_begin(); 4361 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4362 QualType C1Ty = (*Ptr); 4363 QualType C1; 4364 QualifierCollector Q1; 4365 if (const PointerType *PointerTy = C1Ty->getAs<PointerType>()) { 4366 C1 = QualType(Q1.strip(PointerTy->getPointeeType()), 0); 4367 if (!isa<RecordType>(C1)) 4368 continue; 4369 // heuristic to reduce number of builtin candidates in the set. 4370 // Add volatile/restrict version only if there are conversions to a 4371 // volatile/restrict type. 4372 if (!VisibleTypeConversionsQuals.hasVolatile() && Q1.hasVolatile()) 4373 continue; 4374 if (!VisibleTypeConversionsQuals.hasRestrict() && Q1.hasRestrict()) 4375 continue; 4376 } 4377 for (BuiltinCandidateTypeSet::iterator 4378 MemPtr = CandidateTypes.member_pointer_begin(), 4379 MemPtrEnd = CandidateTypes.member_pointer_end(); 4380 MemPtr != MemPtrEnd; ++MemPtr) { 4381 const MemberPointerType *mptr = cast<MemberPointerType>(*MemPtr); 4382 QualType C2 = QualType(mptr->getClass(), 0); 4383 C2 = C2.getUnqualifiedType(); 4384 if (C1 != C2 && !IsDerivedFrom(C1, C2)) 4385 break; 4386 QualType ParamTypes[2] = { *Ptr, *MemPtr }; 4387 // build CV12 T& 4388 QualType T = mptr->getPointeeType(); 4389 if (!VisibleTypeConversionsQuals.hasVolatile() && 4390 T.isVolatileQualified()) 4391 continue; 4392 if (!VisibleTypeConversionsQuals.hasRestrict() && 4393 T.isRestrictQualified()) 4394 continue; 4395 T = Q1.apply(T); 4396 QualType ResultTy = Context.getLValueReferenceType(T); 4397 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 4398 } 4399 } 4400 } 4401 break; 4402 4403 case OO_Conditional: 4404 // Note that we don't consider the first argument, since it has been 4405 // contextually converted to bool long ago. The candidates below are 4406 // therefore added as binary. 4407 // 4408 // C++ [over.built]p24: 4409 // For every type T, where T is a pointer or pointer-to-member type, 4410 // there exist candidate operator functions of the form 4411 // 4412 // T operator?(bool, T, T); 4413 // 4414 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(), 4415 E = CandidateTypes.pointer_end(); Ptr != E; ++Ptr) { 4416 QualType ParamTypes[2] = { *Ptr, *Ptr }; 4417 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 4418 } 4419 for (BuiltinCandidateTypeSet::iterator Ptr = 4420 CandidateTypes.member_pointer_begin(), 4421 E = CandidateTypes.member_pointer_end(); Ptr != E; ++Ptr) { 4422 QualType ParamTypes[2] = { *Ptr, *Ptr }; 4423 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 4424 } 4425 goto Conditional; 4426 } 4427} 4428 4429/// \brief Add function candidates found via argument-dependent lookup 4430/// to the set of overloading candidates. 4431/// 4432/// This routine performs argument-dependent name lookup based on the 4433/// given function name (which may also be an operator name) and adds 4434/// all of the overload candidates found by ADL to the overload 4435/// candidate set (C++ [basic.lookup.argdep]). 4436void 4437Sema::AddArgumentDependentLookupCandidates(DeclarationName Name, 4438 bool Operator, 4439 Expr **Args, unsigned NumArgs, 4440 const TemplateArgumentListInfo *ExplicitTemplateArgs, 4441 OverloadCandidateSet& CandidateSet, 4442 bool PartialOverloading) { 4443 ADLResult Fns; 4444 4445 // FIXME: This approach for uniquing ADL results (and removing 4446 // redundant candidates from the set) relies on pointer-equality, 4447 // which means we need to key off the canonical decl. However, 4448 // always going back to the canonical decl might not get us the 4449 // right set of default arguments. What default arguments are 4450 // we supposed to consider on ADL candidates, anyway? 4451 4452 // FIXME: Pass in the explicit template arguments? 4453 ArgumentDependentLookup(Name, Operator, Args, NumArgs, Fns); 4454 4455 // Erase all of the candidates we already knew about. 4456 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 4457 CandEnd = CandidateSet.end(); 4458 Cand != CandEnd; ++Cand) 4459 if (Cand->Function) { 4460 Fns.erase(Cand->Function); 4461 if (FunctionTemplateDecl *FunTmpl = Cand->Function->getPrimaryTemplate()) 4462 Fns.erase(FunTmpl); 4463 } 4464 4465 // For each of the ADL candidates we found, add it to the overload 4466 // set. 4467 for (ADLResult::iterator I = Fns.begin(), E = Fns.end(); I != E; ++I) { 4468 DeclAccessPair FoundDecl = DeclAccessPair::make(*I, AS_none); 4469 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*I)) { 4470 if (ExplicitTemplateArgs) 4471 continue; 4472 4473 AddOverloadCandidate(FD, FoundDecl, Args, NumArgs, CandidateSet, 4474 false, PartialOverloading); 4475 } else 4476 AddTemplateOverloadCandidate(cast<FunctionTemplateDecl>(*I), 4477 FoundDecl, ExplicitTemplateArgs, 4478 Args, NumArgs, CandidateSet); 4479 } 4480} 4481 4482/// isBetterOverloadCandidate - Determines whether the first overload 4483/// candidate is a better candidate than the second (C++ 13.3.3p1). 4484bool 4485Sema::isBetterOverloadCandidate(const OverloadCandidate& Cand1, 4486 const OverloadCandidate& Cand2, 4487 SourceLocation Loc) { 4488 // Define viable functions to be better candidates than non-viable 4489 // functions. 4490 if (!Cand2.Viable) 4491 return Cand1.Viable; 4492 else if (!Cand1.Viable) 4493 return false; 4494 4495 // C++ [over.match.best]p1: 4496 // 4497 // -- if F is a static member function, ICS1(F) is defined such 4498 // that ICS1(F) is neither better nor worse than ICS1(G) for 4499 // any function G, and, symmetrically, ICS1(G) is neither 4500 // better nor worse than ICS1(F). 4501 unsigned StartArg = 0; 4502 if (Cand1.IgnoreObjectArgument || Cand2.IgnoreObjectArgument) 4503 StartArg = 1; 4504 4505 // C++ [over.match.best]p1: 4506 // A viable function F1 is defined to be a better function than another 4507 // viable function F2 if for all arguments i, ICSi(F1) is not a worse 4508 // conversion sequence than ICSi(F2), and then... 4509 unsigned NumArgs = Cand1.Conversions.size(); 4510 assert(Cand2.Conversions.size() == NumArgs && "Overload candidate mismatch"); 4511 bool HasBetterConversion = false; 4512 for (unsigned ArgIdx = StartArg; ArgIdx < NumArgs; ++ArgIdx) { 4513 switch (CompareImplicitConversionSequences(Cand1.Conversions[ArgIdx], 4514 Cand2.Conversions[ArgIdx])) { 4515 case ImplicitConversionSequence::Better: 4516 // Cand1 has a better conversion sequence. 4517 HasBetterConversion = true; 4518 break; 4519 4520 case ImplicitConversionSequence::Worse: 4521 // Cand1 can't be better than Cand2. 4522 return false; 4523 4524 case ImplicitConversionSequence::Indistinguishable: 4525 // Do nothing. 4526 break; 4527 } 4528 } 4529 4530 // -- for some argument j, ICSj(F1) is a better conversion sequence than 4531 // ICSj(F2), or, if not that, 4532 if (HasBetterConversion) 4533 return true; 4534 4535 // - F1 is a non-template function and F2 is a function template 4536 // specialization, or, if not that, 4537 if (Cand1.Function && !Cand1.Function->getPrimaryTemplate() && 4538 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 4539 return true; 4540 4541 // -- F1 and F2 are function template specializations, and the function 4542 // template for F1 is more specialized than the template for F2 4543 // according to the partial ordering rules described in 14.5.5.2, or, 4544 // if not that, 4545 if (Cand1.Function && Cand1.Function->getPrimaryTemplate() && 4546 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 4547 if (FunctionTemplateDecl *BetterTemplate 4548 = getMoreSpecializedTemplate(Cand1.Function->getPrimaryTemplate(), 4549 Cand2.Function->getPrimaryTemplate(), 4550 Loc, 4551 isa<CXXConversionDecl>(Cand1.Function)? TPOC_Conversion 4552 : TPOC_Call)) 4553 return BetterTemplate == Cand1.Function->getPrimaryTemplate(); 4554 4555 // -- the context is an initialization by user-defined conversion 4556 // (see 8.5, 13.3.1.5) and the standard conversion sequence 4557 // from the return type of F1 to the destination type (i.e., 4558 // the type of the entity being initialized) is a better 4559 // conversion sequence than the standard conversion sequence 4560 // from the return type of F2 to the destination type. 4561 if (Cand1.Function && Cand2.Function && 4562 isa<CXXConversionDecl>(Cand1.Function) && 4563 isa<CXXConversionDecl>(Cand2.Function)) { 4564 switch (CompareStandardConversionSequences(Cand1.FinalConversion, 4565 Cand2.FinalConversion)) { 4566 case ImplicitConversionSequence::Better: 4567 // Cand1 has a better conversion sequence. 4568 return true; 4569 4570 case ImplicitConversionSequence::Worse: 4571 // Cand1 can't be better than Cand2. 4572 return false; 4573 4574 case ImplicitConversionSequence::Indistinguishable: 4575 // Do nothing 4576 break; 4577 } 4578 } 4579 4580 return false; 4581} 4582 4583/// \brief Computes the best viable function (C++ 13.3.3) 4584/// within an overload candidate set. 4585/// 4586/// \param CandidateSet the set of candidate functions. 4587/// 4588/// \param Loc the location of the function name (or operator symbol) for 4589/// which overload resolution occurs. 4590/// 4591/// \param Best f overload resolution was successful or found a deleted 4592/// function, Best points to the candidate function found. 4593/// 4594/// \returns The result of overload resolution. 4595OverloadingResult Sema::BestViableFunction(OverloadCandidateSet& CandidateSet, 4596 SourceLocation Loc, 4597 OverloadCandidateSet::iterator& Best) { 4598 // Find the best viable function. 4599 Best = CandidateSet.end(); 4600 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 4601 Cand != CandidateSet.end(); ++Cand) { 4602 if (Cand->Viable) { 4603 if (Best == CandidateSet.end() || 4604 isBetterOverloadCandidate(*Cand, *Best, Loc)) 4605 Best = Cand; 4606 } 4607 } 4608 4609 // If we didn't find any viable functions, abort. 4610 if (Best == CandidateSet.end()) 4611 return OR_No_Viable_Function; 4612 4613 // Make sure that this function is better than every other viable 4614 // function. If not, we have an ambiguity. 4615 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 4616 Cand != CandidateSet.end(); ++Cand) { 4617 if (Cand->Viable && 4618 Cand != Best && 4619 !isBetterOverloadCandidate(*Best, *Cand, Loc)) { 4620 Best = CandidateSet.end(); 4621 return OR_Ambiguous; 4622 } 4623 } 4624 4625 // Best is the best viable function. 4626 if (Best->Function && 4627 (Best->Function->isDeleted() || 4628 Best->Function->getAttr<UnavailableAttr>())) 4629 return OR_Deleted; 4630 4631 // C++ [basic.def.odr]p2: 4632 // An overloaded function is used if it is selected by overload resolution 4633 // when referred to from a potentially-evaluated expression. [Note: this 4634 // covers calls to named functions (5.2.2), operator overloading 4635 // (clause 13), user-defined conversions (12.3.2), allocation function for 4636 // placement new (5.3.4), as well as non-default initialization (8.5). 4637 if (Best->Function) 4638 MarkDeclarationReferenced(Loc, Best->Function); 4639 return OR_Success; 4640} 4641 4642namespace { 4643 4644enum OverloadCandidateKind { 4645 oc_function, 4646 oc_method, 4647 oc_constructor, 4648 oc_function_template, 4649 oc_method_template, 4650 oc_constructor_template, 4651 oc_implicit_default_constructor, 4652 oc_implicit_copy_constructor, 4653 oc_implicit_copy_assignment 4654}; 4655 4656OverloadCandidateKind ClassifyOverloadCandidate(Sema &S, 4657 FunctionDecl *Fn, 4658 std::string &Description) { 4659 bool isTemplate = false; 4660 4661 if (FunctionTemplateDecl *FunTmpl = Fn->getPrimaryTemplate()) { 4662 isTemplate = true; 4663 Description = S.getTemplateArgumentBindingsText( 4664 FunTmpl->getTemplateParameters(), *Fn->getTemplateSpecializationArgs()); 4665 } 4666 4667 if (CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(Fn)) { 4668 if (!Ctor->isImplicit()) 4669 return isTemplate ? oc_constructor_template : oc_constructor; 4670 4671 return Ctor->isCopyConstructor() ? oc_implicit_copy_constructor 4672 : oc_implicit_default_constructor; 4673 } 4674 4675 if (CXXMethodDecl *Meth = dyn_cast<CXXMethodDecl>(Fn)) { 4676 // This actually gets spelled 'candidate function' for now, but 4677 // it doesn't hurt to split it out. 4678 if (!Meth->isImplicit()) 4679 return isTemplate ? oc_method_template : oc_method; 4680 4681 assert(Meth->isCopyAssignment() 4682 && "implicit method is not copy assignment operator?"); 4683 return oc_implicit_copy_assignment; 4684 } 4685 4686 return isTemplate ? oc_function_template : oc_function; 4687} 4688 4689} // end anonymous namespace 4690 4691// Notes the location of an overload candidate. 4692void Sema::NoteOverloadCandidate(FunctionDecl *Fn) { 4693 std::string FnDesc; 4694 OverloadCandidateKind K = ClassifyOverloadCandidate(*this, Fn, FnDesc); 4695 Diag(Fn->getLocation(), diag::note_ovl_candidate) 4696 << (unsigned) K << FnDesc; 4697} 4698 4699/// Diagnoses an ambiguous conversion. The partial diagnostic is the 4700/// "lead" diagnostic; it will be given two arguments, the source and 4701/// target types of the conversion. 4702void Sema::DiagnoseAmbiguousConversion(const ImplicitConversionSequence &ICS, 4703 SourceLocation CaretLoc, 4704 const PartialDiagnostic &PDiag) { 4705 Diag(CaretLoc, PDiag) 4706 << ICS.Ambiguous.getFromType() << ICS.Ambiguous.getToType(); 4707 for (AmbiguousConversionSequence::const_iterator 4708 I = ICS.Ambiguous.begin(), E = ICS.Ambiguous.end(); I != E; ++I) { 4709 NoteOverloadCandidate(*I); 4710 } 4711} 4712 4713namespace { 4714 4715void DiagnoseBadConversion(Sema &S, OverloadCandidate *Cand, unsigned I) { 4716 const ImplicitConversionSequence &Conv = Cand->Conversions[I]; 4717 assert(Conv.isBad()); 4718 assert(Cand->Function && "for now, candidate must be a function"); 4719 FunctionDecl *Fn = Cand->Function; 4720 4721 // There's a conversion slot for the object argument if this is a 4722 // non-constructor method. Note that 'I' corresponds the 4723 // conversion-slot index. 4724 bool isObjectArgument = false; 4725 if (isa<CXXMethodDecl>(Fn) && !isa<CXXConstructorDecl>(Fn)) { 4726 if (I == 0) 4727 isObjectArgument = true; 4728 else 4729 I--; 4730 } 4731 4732 std::string FnDesc; 4733 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, FnDesc); 4734 4735 Expr *FromExpr = Conv.Bad.FromExpr; 4736 QualType FromTy = Conv.Bad.getFromType(); 4737 QualType ToTy = Conv.Bad.getToType(); 4738 4739 if (FromTy == S.Context.OverloadTy) { 4740 assert(FromExpr && "overload set argument came from implicit argument?"); 4741 Expr *E = FromExpr->IgnoreParens(); 4742 if (isa<UnaryOperator>(E)) 4743 E = cast<UnaryOperator>(E)->getSubExpr()->IgnoreParens(); 4744 DeclarationName Name = cast<OverloadExpr>(E)->getName(); 4745 4746 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_overload) 4747 << (unsigned) FnKind << FnDesc 4748 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 4749 << ToTy << Name << I+1; 4750 return; 4751 } 4752 4753 // Do some hand-waving analysis to see if the non-viability is due 4754 // to a qualifier mismatch. 4755 CanQualType CFromTy = S.Context.getCanonicalType(FromTy); 4756 CanQualType CToTy = S.Context.getCanonicalType(ToTy); 4757 if (CanQual<ReferenceType> RT = CToTy->getAs<ReferenceType>()) 4758 CToTy = RT->getPointeeType(); 4759 else { 4760 // TODO: detect and diagnose the full richness of const mismatches. 4761 if (CanQual<PointerType> FromPT = CFromTy->getAs<PointerType>()) 4762 if (CanQual<PointerType> ToPT = CToTy->getAs<PointerType>()) 4763 CFromTy = FromPT->getPointeeType(), CToTy = ToPT->getPointeeType(); 4764 } 4765 4766 if (CToTy.getUnqualifiedType() == CFromTy.getUnqualifiedType() && 4767 !CToTy.isAtLeastAsQualifiedAs(CFromTy)) { 4768 // It is dumb that we have to do this here. 4769 while (isa<ArrayType>(CFromTy)) 4770 CFromTy = CFromTy->getAs<ArrayType>()->getElementType(); 4771 while (isa<ArrayType>(CToTy)) 4772 CToTy = CFromTy->getAs<ArrayType>()->getElementType(); 4773 4774 Qualifiers FromQs = CFromTy.getQualifiers(); 4775 Qualifiers ToQs = CToTy.getQualifiers(); 4776 4777 if (FromQs.getAddressSpace() != ToQs.getAddressSpace()) { 4778 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_addrspace) 4779 << (unsigned) FnKind << FnDesc 4780 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 4781 << FromTy 4782 << FromQs.getAddressSpace() << ToQs.getAddressSpace() 4783 << (unsigned) isObjectArgument << I+1; 4784 return; 4785 } 4786 4787 unsigned CVR = FromQs.getCVRQualifiers() & ~ToQs.getCVRQualifiers(); 4788 assert(CVR && "unexpected qualifiers mismatch"); 4789 4790 if (isObjectArgument) { 4791 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr_this) 4792 << (unsigned) FnKind << FnDesc 4793 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 4794 << FromTy << (CVR - 1); 4795 } else { 4796 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr) 4797 << (unsigned) FnKind << FnDesc 4798 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 4799 << FromTy << (CVR - 1) << I+1; 4800 } 4801 return; 4802 } 4803 4804 // Diagnose references or pointers to incomplete types differently, 4805 // since it's far from impossible that the incompleteness triggered 4806 // the failure. 4807 QualType TempFromTy = FromTy.getNonReferenceType(); 4808 if (const PointerType *PTy = TempFromTy->getAs<PointerType>()) 4809 TempFromTy = PTy->getPointeeType(); 4810 if (TempFromTy->isIncompleteType()) { 4811 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_conv_incomplete) 4812 << (unsigned) FnKind << FnDesc 4813 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 4814 << FromTy << ToTy << (unsigned) isObjectArgument << I+1; 4815 return; 4816 } 4817 4818 // TODO: specialize more based on the kind of mismatch 4819 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_conv) 4820 << (unsigned) FnKind << FnDesc 4821 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 4822 << FromTy << ToTy << (unsigned) isObjectArgument << I+1; 4823} 4824 4825void DiagnoseArityMismatch(Sema &S, OverloadCandidate *Cand, 4826 unsigned NumFormalArgs) { 4827 // TODO: treat calls to a missing default constructor as a special case 4828 4829 FunctionDecl *Fn = Cand->Function; 4830 const FunctionProtoType *FnTy = Fn->getType()->getAs<FunctionProtoType>(); 4831 4832 unsigned MinParams = Fn->getMinRequiredArguments(); 4833 4834 // at least / at most / exactly 4835 unsigned mode, modeCount; 4836 if (NumFormalArgs < MinParams) { 4837 assert(Cand->FailureKind == ovl_fail_too_few_arguments); 4838 if (MinParams != FnTy->getNumArgs() || FnTy->isVariadic()) 4839 mode = 0; // "at least" 4840 else 4841 mode = 2; // "exactly" 4842 modeCount = MinParams; 4843 } else { 4844 assert(Cand->FailureKind == ovl_fail_too_many_arguments); 4845 if (MinParams != FnTy->getNumArgs()) 4846 mode = 1; // "at most" 4847 else 4848 mode = 2; // "exactly" 4849 modeCount = FnTy->getNumArgs(); 4850 } 4851 4852 std::string Description; 4853 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, Description); 4854 4855 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_arity) 4856 << (unsigned) FnKind << Description << mode << modeCount << NumFormalArgs; 4857} 4858 4859/// Diagnose a failed template-argument deduction. 4860void DiagnoseBadDeduction(Sema &S, OverloadCandidate *Cand, 4861 Expr **Args, unsigned NumArgs) { 4862 FunctionDecl *Fn = Cand->Function; // pattern 4863 4864 TemplateParameter Param = TemplateParameter::getFromOpaqueValue( 4865 Cand->DeductionFailure.TemplateParameter); 4866 4867 switch (Cand->DeductionFailure.Result) { 4868 case Sema::TDK_Success: 4869 llvm_unreachable("TDK_success while diagnosing bad deduction"); 4870 4871 case Sema::TDK_Incomplete: { 4872 NamedDecl *ParamD; 4873 (ParamD = Param.dyn_cast<TemplateTypeParmDecl*>()) || 4874 (ParamD = Param.dyn_cast<NonTypeTemplateParmDecl*>()) || 4875 (ParamD = Param.dyn_cast<TemplateTemplateParmDecl*>()); 4876 assert(ParamD && "no parameter found for incomplete deduction result"); 4877 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_incomplete_deduction) 4878 << ParamD->getDeclName(); 4879 return; 4880 } 4881 4882 // TODO: diagnose these individually, then kill off 4883 // note_ovl_candidate_bad_deduction, which is uselessly vague. 4884 case Sema::TDK_InstantiationDepth: 4885 case Sema::TDK_Inconsistent: 4886 case Sema::TDK_InconsistentQuals: 4887 case Sema::TDK_SubstitutionFailure: 4888 case Sema::TDK_NonDeducedMismatch: 4889 case Sema::TDK_TooManyArguments: 4890 case Sema::TDK_TooFewArguments: 4891 case Sema::TDK_InvalidExplicitArguments: 4892 case Sema::TDK_FailedOverloadResolution: 4893 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_deduction); 4894 return; 4895 } 4896} 4897 4898/// Generates a 'note' diagnostic for an overload candidate. We've 4899/// already generated a primary error at the call site. 4900/// 4901/// It really does need to be a single diagnostic with its caret 4902/// pointed at the candidate declaration. Yes, this creates some 4903/// major challenges of technical writing. Yes, this makes pointing 4904/// out problems with specific arguments quite awkward. It's still 4905/// better than generating twenty screens of text for every failed 4906/// overload. 4907/// 4908/// It would be great to be able to express per-candidate problems 4909/// more richly for those diagnostic clients that cared, but we'd 4910/// still have to be just as careful with the default diagnostics. 4911void NoteFunctionCandidate(Sema &S, OverloadCandidate *Cand, 4912 Expr **Args, unsigned NumArgs) { 4913 FunctionDecl *Fn = Cand->Function; 4914 4915 // Note deleted candidates, but only if they're viable. 4916 if (Cand->Viable && (Fn->isDeleted() || Fn->hasAttr<UnavailableAttr>())) { 4917 std::string FnDesc; 4918 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, FnDesc); 4919 4920 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_deleted) 4921 << FnKind << FnDesc << Fn->isDeleted(); 4922 return; 4923 } 4924 4925 // We don't really have anything else to say about viable candidates. 4926 if (Cand->Viable) { 4927 S.NoteOverloadCandidate(Fn); 4928 return; 4929 } 4930 4931 switch (Cand->FailureKind) { 4932 case ovl_fail_too_many_arguments: 4933 case ovl_fail_too_few_arguments: 4934 return DiagnoseArityMismatch(S, Cand, NumArgs); 4935 4936 case ovl_fail_bad_deduction: 4937 return DiagnoseBadDeduction(S, Cand, Args, NumArgs); 4938 4939 case ovl_fail_trivial_conversion: 4940 case ovl_fail_bad_final_conversion: 4941 case ovl_fail_final_conversion_not_exact: 4942 return S.NoteOverloadCandidate(Fn); 4943 4944 case ovl_fail_bad_conversion: { 4945 unsigned I = (Cand->IgnoreObjectArgument ? 1 : 0); 4946 for (unsigned N = Cand->Conversions.size(); I != N; ++I) 4947 if (Cand->Conversions[I].isBad()) 4948 return DiagnoseBadConversion(S, Cand, I); 4949 4950 // FIXME: this currently happens when we're called from SemaInit 4951 // when user-conversion overload fails. Figure out how to handle 4952 // those conditions and diagnose them well. 4953 return S.NoteOverloadCandidate(Fn); 4954 } 4955 } 4956} 4957 4958void NoteSurrogateCandidate(Sema &S, OverloadCandidate *Cand) { 4959 // Desugar the type of the surrogate down to a function type, 4960 // retaining as many typedefs as possible while still showing 4961 // the function type (and, therefore, its parameter types). 4962 QualType FnType = Cand->Surrogate->getConversionType(); 4963 bool isLValueReference = false; 4964 bool isRValueReference = false; 4965 bool isPointer = false; 4966 if (const LValueReferenceType *FnTypeRef = 4967 FnType->getAs<LValueReferenceType>()) { 4968 FnType = FnTypeRef->getPointeeType(); 4969 isLValueReference = true; 4970 } else if (const RValueReferenceType *FnTypeRef = 4971 FnType->getAs<RValueReferenceType>()) { 4972 FnType = FnTypeRef->getPointeeType(); 4973 isRValueReference = true; 4974 } 4975 if (const PointerType *FnTypePtr = FnType->getAs<PointerType>()) { 4976 FnType = FnTypePtr->getPointeeType(); 4977 isPointer = true; 4978 } 4979 // Desugar down to a function type. 4980 FnType = QualType(FnType->getAs<FunctionType>(), 0); 4981 // Reconstruct the pointer/reference as appropriate. 4982 if (isPointer) FnType = S.Context.getPointerType(FnType); 4983 if (isRValueReference) FnType = S.Context.getRValueReferenceType(FnType); 4984 if (isLValueReference) FnType = S.Context.getLValueReferenceType(FnType); 4985 4986 S.Diag(Cand->Surrogate->getLocation(), diag::note_ovl_surrogate_cand) 4987 << FnType; 4988} 4989 4990void NoteBuiltinOperatorCandidate(Sema &S, 4991 const char *Opc, 4992 SourceLocation OpLoc, 4993 OverloadCandidate *Cand) { 4994 assert(Cand->Conversions.size() <= 2 && "builtin operator is not binary"); 4995 std::string TypeStr("operator"); 4996 TypeStr += Opc; 4997 TypeStr += "("; 4998 TypeStr += Cand->BuiltinTypes.ParamTypes[0].getAsString(); 4999 if (Cand->Conversions.size() == 1) { 5000 TypeStr += ")"; 5001 S.Diag(OpLoc, diag::note_ovl_builtin_unary_candidate) << TypeStr; 5002 } else { 5003 TypeStr += ", "; 5004 TypeStr += Cand->BuiltinTypes.ParamTypes[1].getAsString(); 5005 TypeStr += ")"; 5006 S.Diag(OpLoc, diag::note_ovl_builtin_binary_candidate) << TypeStr; 5007 } 5008} 5009 5010void NoteAmbiguousUserConversions(Sema &S, SourceLocation OpLoc, 5011 OverloadCandidate *Cand) { 5012 unsigned NoOperands = Cand->Conversions.size(); 5013 for (unsigned ArgIdx = 0; ArgIdx < NoOperands; ++ArgIdx) { 5014 const ImplicitConversionSequence &ICS = Cand->Conversions[ArgIdx]; 5015 if (ICS.isBad()) break; // all meaningless after first invalid 5016 if (!ICS.isAmbiguous()) continue; 5017 5018 S.DiagnoseAmbiguousConversion(ICS, OpLoc, 5019 S.PDiag(diag::note_ambiguous_type_conversion)); 5020 } 5021} 5022 5023SourceLocation GetLocationForCandidate(const OverloadCandidate *Cand) { 5024 if (Cand->Function) 5025 return Cand->Function->getLocation(); 5026 if (Cand->IsSurrogate) 5027 return Cand->Surrogate->getLocation(); 5028 return SourceLocation(); 5029} 5030 5031struct CompareOverloadCandidatesForDisplay { 5032 Sema &S; 5033 CompareOverloadCandidatesForDisplay(Sema &S) : S(S) {} 5034 5035 bool operator()(const OverloadCandidate *L, 5036 const OverloadCandidate *R) { 5037 // Fast-path this check. 5038 if (L == R) return false; 5039 5040 // Order first by viability. 5041 if (L->Viable) { 5042 if (!R->Viable) return true; 5043 5044 // TODO: introduce a tri-valued comparison for overload 5045 // candidates. Would be more worthwhile if we had a sort 5046 // that could exploit it. 5047 if (S.isBetterOverloadCandidate(*L, *R, SourceLocation())) return true; 5048 if (S.isBetterOverloadCandidate(*R, *L, SourceLocation())) return false; 5049 } else if (R->Viable) 5050 return false; 5051 5052 assert(L->Viable == R->Viable); 5053 5054 // Criteria by which we can sort non-viable candidates: 5055 if (!L->Viable) { 5056 // 1. Arity mismatches come after other candidates. 5057 if (L->FailureKind == ovl_fail_too_many_arguments || 5058 L->FailureKind == ovl_fail_too_few_arguments) 5059 return false; 5060 if (R->FailureKind == ovl_fail_too_many_arguments || 5061 R->FailureKind == ovl_fail_too_few_arguments) 5062 return true; 5063 5064 // 2. Bad conversions come first and are ordered by the number 5065 // of bad conversions and quality of good conversions. 5066 if (L->FailureKind == ovl_fail_bad_conversion) { 5067 if (R->FailureKind != ovl_fail_bad_conversion) 5068 return true; 5069 5070 // If there's any ordering between the defined conversions... 5071 // FIXME: this might not be transitive. 5072 assert(L->Conversions.size() == R->Conversions.size()); 5073 5074 int leftBetter = 0; 5075 unsigned I = (L->IgnoreObjectArgument || R->IgnoreObjectArgument); 5076 for (unsigned E = L->Conversions.size(); I != E; ++I) { 5077 switch (S.CompareImplicitConversionSequences(L->Conversions[I], 5078 R->Conversions[I])) { 5079 case ImplicitConversionSequence::Better: 5080 leftBetter++; 5081 break; 5082 5083 case ImplicitConversionSequence::Worse: 5084 leftBetter--; 5085 break; 5086 5087 case ImplicitConversionSequence::Indistinguishable: 5088 break; 5089 } 5090 } 5091 if (leftBetter > 0) return true; 5092 if (leftBetter < 0) return false; 5093 5094 } else if (R->FailureKind == ovl_fail_bad_conversion) 5095 return false; 5096 5097 // TODO: others? 5098 } 5099 5100 // Sort everything else by location. 5101 SourceLocation LLoc = GetLocationForCandidate(L); 5102 SourceLocation RLoc = GetLocationForCandidate(R); 5103 5104 // Put candidates without locations (e.g. builtins) at the end. 5105 if (LLoc.isInvalid()) return false; 5106 if (RLoc.isInvalid()) return true; 5107 5108 return S.SourceMgr.isBeforeInTranslationUnit(LLoc, RLoc); 5109 } 5110}; 5111 5112/// CompleteNonViableCandidate - Normally, overload resolution only 5113/// computes up to the first 5114void CompleteNonViableCandidate(Sema &S, OverloadCandidate *Cand, 5115 Expr **Args, unsigned NumArgs) { 5116 assert(!Cand->Viable); 5117 5118 // Don't do anything on failures other than bad conversion. 5119 if (Cand->FailureKind != ovl_fail_bad_conversion) return; 5120 5121 // Skip forward to the first bad conversion. 5122 unsigned ConvIdx = (Cand->IgnoreObjectArgument ? 1 : 0); 5123 unsigned ConvCount = Cand->Conversions.size(); 5124 while (true) { 5125 assert(ConvIdx != ConvCount && "no bad conversion in candidate"); 5126 ConvIdx++; 5127 if (Cand->Conversions[ConvIdx - 1].isBad()) 5128 break; 5129 } 5130 5131 if (ConvIdx == ConvCount) 5132 return; 5133 5134 assert(!Cand->Conversions[ConvIdx].isInitialized() && 5135 "remaining conversion is initialized?"); 5136 5137 // FIXME: this should probably be preserved from the overload 5138 // operation somehow. 5139 bool SuppressUserConversions = false; 5140 5141 const FunctionProtoType* Proto; 5142 unsigned ArgIdx = ConvIdx; 5143 5144 if (Cand->IsSurrogate) { 5145 QualType ConvType 5146 = Cand->Surrogate->getConversionType().getNonReferenceType(); 5147 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 5148 ConvType = ConvPtrType->getPointeeType(); 5149 Proto = ConvType->getAs<FunctionProtoType>(); 5150 ArgIdx--; 5151 } else if (Cand->Function) { 5152 Proto = Cand->Function->getType()->getAs<FunctionProtoType>(); 5153 if (isa<CXXMethodDecl>(Cand->Function) && 5154 !isa<CXXConstructorDecl>(Cand->Function)) 5155 ArgIdx--; 5156 } else { 5157 // Builtin binary operator with a bad first conversion. 5158 assert(ConvCount <= 3); 5159 for (; ConvIdx != ConvCount; ++ConvIdx) 5160 Cand->Conversions[ConvIdx] 5161 = TryCopyInitialization(S, Args[ConvIdx], 5162 Cand->BuiltinTypes.ParamTypes[ConvIdx], 5163 SuppressUserConversions, 5164 /*InOverloadResolution*/ true); 5165 return; 5166 } 5167 5168 // Fill in the rest of the conversions. 5169 unsigned NumArgsInProto = Proto->getNumArgs(); 5170 for (; ConvIdx != ConvCount; ++ConvIdx, ++ArgIdx) { 5171 if (ArgIdx < NumArgsInProto) 5172 Cand->Conversions[ConvIdx] 5173 = TryCopyInitialization(S, Args[ArgIdx], Proto->getArgType(ArgIdx), 5174 SuppressUserConversions, 5175 /*InOverloadResolution=*/true); 5176 else 5177 Cand->Conversions[ConvIdx].setEllipsis(); 5178 } 5179} 5180 5181} // end anonymous namespace 5182 5183/// PrintOverloadCandidates - When overload resolution fails, prints 5184/// diagnostic messages containing the candidates in the candidate 5185/// set. 5186void 5187Sema::PrintOverloadCandidates(OverloadCandidateSet& CandidateSet, 5188 OverloadCandidateDisplayKind OCD, 5189 Expr **Args, unsigned NumArgs, 5190 const char *Opc, 5191 SourceLocation OpLoc) { 5192 // Sort the candidates by viability and position. Sorting directly would 5193 // be prohibitive, so we make a set of pointers and sort those. 5194 llvm::SmallVector<OverloadCandidate*, 32> Cands; 5195 if (OCD == OCD_AllCandidates) Cands.reserve(CandidateSet.size()); 5196 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 5197 LastCand = CandidateSet.end(); 5198 Cand != LastCand; ++Cand) { 5199 if (Cand->Viable) 5200 Cands.push_back(Cand); 5201 else if (OCD == OCD_AllCandidates) { 5202 CompleteNonViableCandidate(*this, Cand, Args, NumArgs); 5203 Cands.push_back(Cand); 5204 } 5205 } 5206 5207 std::sort(Cands.begin(), Cands.end(), 5208 CompareOverloadCandidatesForDisplay(*this)); 5209 5210 bool ReportedAmbiguousConversions = false; 5211 5212 llvm::SmallVectorImpl<OverloadCandidate*>::iterator I, E; 5213 for (I = Cands.begin(), E = Cands.end(); I != E; ++I) { 5214 OverloadCandidate *Cand = *I; 5215 5216 if (Cand->Function) 5217 NoteFunctionCandidate(*this, Cand, Args, NumArgs); 5218 else if (Cand->IsSurrogate) 5219 NoteSurrogateCandidate(*this, Cand); 5220 5221 // This a builtin candidate. We do not, in general, want to list 5222 // every possible builtin candidate. 5223 else if (Cand->Viable) { 5224 // Generally we only see ambiguities including viable builtin 5225 // operators if overload resolution got screwed up by an 5226 // ambiguous user-defined conversion. 5227 // 5228 // FIXME: It's quite possible for different conversions to see 5229 // different ambiguities, though. 5230 if (!ReportedAmbiguousConversions) { 5231 NoteAmbiguousUserConversions(*this, OpLoc, Cand); 5232 ReportedAmbiguousConversions = true; 5233 } 5234 5235 // If this is a viable builtin, print it. 5236 NoteBuiltinOperatorCandidate(*this, Opc, OpLoc, Cand); 5237 } 5238 } 5239} 5240 5241static bool CheckUnresolvedAccess(Sema &S, OverloadExpr *E, DeclAccessPair D) { 5242 if (isa<UnresolvedLookupExpr>(E)) 5243 return S.CheckUnresolvedLookupAccess(cast<UnresolvedLookupExpr>(E), D); 5244 5245 return S.CheckUnresolvedMemberAccess(cast<UnresolvedMemberExpr>(E), D); 5246} 5247 5248/// ResolveAddressOfOverloadedFunction - Try to resolve the address of 5249/// an overloaded function (C++ [over.over]), where @p From is an 5250/// expression with overloaded function type and @p ToType is the type 5251/// we're trying to resolve to. For example: 5252/// 5253/// @code 5254/// int f(double); 5255/// int f(int); 5256/// 5257/// int (*pfd)(double) = f; // selects f(double) 5258/// @endcode 5259/// 5260/// This routine returns the resulting FunctionDecl if it could be 5261/// resolved, and NULL otherwise. When @p Complain is true, this 5262/// routine will emit diagnostics if there is an error. 5263FunctionDecl * 5264Sema::ResolveAddressOfOverloadedFunction(Expr *From, QualType ToType, 5265 bool Complain, 5266 DeclAccessPair &FoundResult) { 5267 QualType FunctionType = ToType; 5268 bool IsMember = false; 5269 if (const PointerType *ToTypePtr = ToType->getAs<PointerType>()) 5270 FunctionType = ToTypePtr->getPointeeType(); 5271 else if (const ReferenceType *ToTypeRef = ToType->getAs<ReferenceType>()) 5272 FunctionType = ToTypeRef->getPointeeType(); 5273 else if (const MemberPointerType *MemTypePtr = 5274 ToType->getAs<MemberPointerType>()) { 5275 FunctionType = MemTypePtr->getPointeeType(); 5276 IsMember = true; 5277 } 5278 5279 // C++ [over.over]p1: 5280 // [...] [Note: any redundant set of parentheses surrounding the 5281 // overloaded function name is ignored (5.1). ] 5282 // C++ [over.over]p1: 5283 // [...] The overloaded function name can be preceded by the & 5284 // operator. 5285 OverloadExpr *OvlExpr = OverloadExpr::find(From).getPointer(); 5286 TemplateArgumentListInfo ETABuffer, *ExplicitTemplateArgs = 0; 5287 if (OvlExpr->hasExplicitTemplateArgs()) { 5288 OvlExpr->getExplicitTemplateArgs().copyInto(ETABuffer); 5289 ExplicitTemplateArgs = &ETABuffer; 5290 } 5291 5292 // We expect a pointer or reference to function, or a function pointer. 5293 FunctionType = Context.getCanonicalType(FunctionType).getUnqualifiedType(); 5294 if (!FunctionType->isFunctionType()) { 5295 if (Complain) 5296 Diag(From->getLocStart(), diag::err_addr_ovl_not_func_ptrref) 5297 << OvlExpr->getName() << ToType; 5298 5299 return 0; 5300 } 5301 5302 assert(From->getType() == Context.OverloadTy); 5303 5304 // Look through all of the overloaded functions, searching for one 5305 // whose type matches exactly. 5306 llvm::SmallVector<std::pair<DeclAccessPair, FunctionDecl*>, 4> Matches; 5307 llvm::SmallVector<FunctionDecl *, 4> NonMatches; 5308 5309 bool FoundNonTemplateFunction = false; 5310 for (UnresolvedSetIterator I = OvlExpr->decls_begin(), 5311 E = OvlExpr->decls_end(); I != E; ++I) { 5312 // Look through any using declarations to find the underlying function. 5313 NamedDecl *Fn = (*I)->getUnderlyingDecl(); 5314 5315 // C++ [over.over]p3: 5316 // Non-member functions and static member functions match 5317 // targets of type "pointer-to-function" or "reference-to-function." 5318 // Nonstatic member functions match targets of 5319 // type "pointer-to-member-function." 5320 // Note that according to DR 247, the containing class does not matter. 5321 5322 if (FunctionTemplateDecl *FunctionTemplate 5323 = dyn_cast<FunctionTemplateDecl>(Fn)) { 5324 if (CXXMethodDecl *Method 5325 = dyn_cast<CXXMethodDecl>(FunctionTemplate->getTemplatedDecl())) { 5326 // Skip non-static function templates when converting to pointer, and 5327 // static when converting to member pointer. 5328 if (Method->isStatic() == IsMember) 5329 continue; 5330 } else if (IsMember) 5331 continue; 5332 5333 // C++ [over.over]p2: 5334 // If the name is a function template, template argument deduction is 5335 // done (14.8.2.2), and if the argument deduction succeeds, the 5336 // resulting template argument list is used to generate a single 5337 // function template specialization, which is added to the set of 5338 // overloaded functions considered. 5339 // FIXME: We don't really want to build the specialization here, do we? 5340 FunctionDecl *Specialization = 0; 5341 TemplateDeductionInfo Info(Context, OvlExpr->getNameLoc()); 5342 if (TemplateDeductionResult Result 5343 = DeduceTemplateArguments(FunctionTemplate, ExplicitTemplateArgs, 5344 FunctionType, Specialization, Info)) { 5345 // FIXME: make a note of the failed deduction for diagnostics. 5346 (void)Result; 5347 } else { 5348 // FIXME: If the match isn't exact, shouldn't we just drop this as 5349 // a candidate? Find a testcase before changing the code. 5350 assert(FunctionType 5351 == Context.getCanonicalType(Specialization->getType())); 5352 Matches.push_back(std::make_pair(I.getPair(), 5353 cast<FunctionDecl>(Specialization->getCanonicalDecl()))); 5354 } 5355 5356 continue; 5357 } 5358 5359 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 5360 // Skip non-static functions when converting to pointer, and static 5361 // when converting to member pointer. 5362 if (Method->isStatic() == IsMember) 5363 continue; 5364 5365 // If we have explicit template arguments, skip non-templates. 5366 if (OvlExpr->hasExplicitTemplateArgs()) 5367 continue; 5368 } else if (IsMember) 5369 continue; 5370 5371 if (FunctionDecl *FunDecl = dyn_cast<FunctionDecl>(Fn)) { 5372 QualType ResultTy; 5373 if (Context.hasSameUnqualifiedType(FunctionType, FunDecl->getType()) || 5374 IsNoReturnConversion(Context, FunDecl->getType(), FunctionType, 5375 ResultTy)) { 5376 Matches.push_back(std::make_pair(I.getPair(), 5377 cast<FunctionDecl>(FunDecl->getCanonicalDecl()))); 5378 FoundNonTemplateFunction = true; 5379 } 5380 } 5381 } 5382 5383 // If there were 0 or 1 matches, we're done. 5384 if (Matches.empty()) { 5385 if (Complain) { 5386 Diag(From->getLocStart(), diag::err_addr_ovl_no_viable) 5387 << OvlExpr->getName() << FunctionType; 5388 for (UnresolvedSetIterator I = OvlExpr->decls_begin(), 5389 E = OvlExpr->decls_end(); 5390 I != E; ++I) 5391 if (FunctionDecl *F = dyn_cast<FunctionDecl>((*I)->getUnderlyingDecl())) 5392 NoteOverloadCandidate(F); 5393 } 5394 5395 return 0; 5396 } else if (Matches.size() == 1) { 5397 FunctionDecl *Result = Matches[0].second; 5398 FoundResult = Matches[0].first; 5399 MarkDeclarationReferenced(From->getLocStart(), Result); 5400 if (Complain) 5401 CheckAddressOfMemberAccess(OvlExpr, Matches[0].first); 5402 return Result; 5403 } 5404 5405 // C++ [over.over]p4: 5406 // If more than one function is selected, [...] 5407 if (!FoundNonTemplateFunction) { 5408 // [...] and any given function template specialization F1 is 5409 // eliminated if the set contains a second function template 5410 // specialization whose function template is more specialized 5411 // than the function template of F1 according to the partial 5412 // ordering rules of 14.5.5.2. 5413 5414 // The algorithm specified above is quadratic. We instead use a 5415 // two-pass algorithm (similar to the one used to identify the 5416 // best viable function in an overload set) that identifies the 5417 // best function template (if it exists). 5418 5419 UnresolvedSet<4> MatchesCopy; // TODO: avoid! 5420 for (unsigned I = 0, E = Matches.size(); I != E; ++I) 5421 MatchesCopy.addDecl(Matches[I].second, Matches[I].first.getAccess()); 5422 5423 UnresolvedSetIterator Result = 5424 getMostSpecialized(MatchesCopy.begin(), MatchesCopy.end(), 5425 TPOC_Other, From->getLocStart(), 5426 PDiag(), 5427 PDiag(diag::err_addr_ovl_ambiguous) 5428 << Matches[0].second->getDeclName(), 5429 PDiag(diag::note_ovl_candidate) 5430 << (unsigned) oc_function_template); 5431 assert(Result != MatchesCopy.end() && "no most-specialized template"); 5432 MarkDeclarationReferenced(From->getLocStart(), *Result); 5433 FoundResult = Matches[Result - MatchesCopy.begin()].first; 5434 if (Complain) 5435 CheckUnresolvedAccess(*this, OvlExpr, FoundResult); 5436 return cast<FunctionDecl>(*Result); 5437 } 5438 5439 // [...] any function template specializations in the set are 5440 // eliminated if the set also contains a non-template function, [...] 5441 for (unsigned I = 0, N = Matches.size(); I != N; ) { 5442 if (Matches[I].second->getPrimaryTemplate() == 0) 5443 ++I; 5444 else { 5445 Matches[I] = Matches[--N]; 5446 Matches.set_size(N); 5447 } 5448 } 5449 5450 // [...] After such eliminations, if any, there shall remain exactly one 5451 // selected function. 5452 if (Matches.size() == 1) { 5453 MarkDeclarationReferenced(From->getLocStart(), Matches[0].second); 5454 FoundResult = Matches[0].first; 5455 if (Complain) 5456 CheckUnresolvedAccess(*this, OvlExpr, Matches[0].first); 5457 return cast<FunctionDecl>(Matches[0].second); 5458 } 5459 5460 // FIXME: We should probably return the same thing that BestViableFunction 5461 // returns (even if we issue the diagnostics here). 5462 Diag(From->getLocStart(), diag::err_addr_ovl_ambiguous) 5463 << Matches[0].second->getDeclName(); 5464 for (unsigned I = 0, E = Matches.size(); I != E; ++I) 5465 NoteOverloadCandidate(Matches[I].second); 5466 return 0; 5467} 5468 5469/// \brief Given an expression that refers to an overloaded function, try to 5470/// resolve that overloaded function expression down to a single function. 5471/// 5472/// This routine can only resolve template-ids that refer to a single function 5473/// template, where that template-id refers to a single template whose template 5474/// arguments are either provided by the template-id or have defaults, 5475/// as described in C++0x [temp.arg.explicit]p3. 5476FunctionDecl *Sema::ResolveSingleFunctionTemplateSpecialization(Expr *From) { 5477 // C++ [over.over]p1: 5478 // [...] [Note: any redundant set of parentheses surrounding the 5479 // overloaded function name is ignored (5.1). ] 5480 // C++ [over.over]p1: 5481 // [...] The overloaded function name can be preceded by the & 5482 // operator. 5483 5484 if (From->getType() != Context.OverloadTy) 5485 return 0; 5486 5487 OverloadExpr *OvlExpr = OverloadExpr::find(From).getPointer(); 5488 5489 // If we didn't actually find any template-ids, we're done. 5490 if (!OvlExpr->hasExplicitTemplateArgs()) 5491 return 0; 5492 5493 TemplateArgumentListInfo ExplicitTemplateArgs; 5494 OvlExpr->getExplicitTemplateArgs().copyInto(ExplicitTemplateArgs); 5495 5496 // Look through all of the overloaded functions, searching for one 5497 // whose type matches exactly. 5498 FunctionDecl *Matched = 0; 5499 for (UnresolvedSetIterator I = OvlExpr->decls_begin(), 5500 E = OvlExpr->decls_end(); I != E; ++I) { 5501 // C++0x [temp.arg.explicit]p3: 5502 // [...] In contexts where deduction is done and fails, or in contexts 5503 // where deduction is not done, if a template argument list is 5504 // specified and it, along with any default template arguments, 5505 // identifies a single function template specialization, then the 5506 // template-id is an lvalue for the function template specialization. 5507 FunctionTemplateDecl *FunctionTemplate = cast<FunctionTemplateDecl>(*I); 5508 5509 // C++ [over.over]p2: 5510 // If the name is a function template, template argument deduction is 5511 // done (14.8.2.2), and if the argument deduction succeeds, the 5512 // resulting template argument list is used to generate a single 5513 // function template specialization, which is added to the set of 5514 // overloaded functions considered. 5515 FunctionDecl *Specialization = 0; 5516 TemplateDeductionInfo Info(Context, OvlExpr->getNameLoc()); 5517 if (TemplateDeductionResult Result 5518 = DeduceTemplateArguments(FunctionTemplate, &ExplicitTemplateArgs, 5519 Specialization, Info)) { 5520 // FIXME: make a note of the failed deduction for diagnostics. 5521 (void)Result; 5522 continue; 5523 } 5524 5525 // Multiple matches; we can't resolve to a single declaration. 5526 if (Matched) 5527 return 0; 5528 5529 Matched = Specialization; 5530 } 5531 5532 return Matched; 5533} 5534 5535/// \brief Add a single candidate to the overload set. 5536static void AddOverloadedCallCandidate(Sema &S, 5537 DeclAccessPair FoundDecl, 5538 const TemplateArgumentListInfo *ExplicitTemplateArgs, 5539 Expr **Args, unsigned NumArgs, 5540 OverloadCandidateSet &CandidateSet, 5541 bool PartialOverloading) { 5542 NamedDecl *Callee = FoundDecl.getDecl(); 5543 if (isa<UsingShadowDecl>(Callee)) 5544 Callee = cast<UsingShadowDecl>(Callee)->getTargetDecl(); 5545 5546 if (FunctionDecl *Func = dyn_cast<FunctionDecl>(Callee)) { 5547 assert(!ExplicitTemplateArgs && "Explicit template arguments?"); 5548 S.AddOverloadCandidate(Func, FoundDecl, Args, NumArgs, CandidateSet, 5549 false, PartialOverloading); 5550 return; 5551 } 5552 5553 if (FunctionTemplateDecl *FuncTemplate 5554 = dyn_cast<FunctionTemplateDecl>(Callee)) { 5555 S.AddTemplateOverloadCandidate(FuncTemplate, FoundDecl, 5556 ExplicitTemplateArgs, 5557 Args, NumArgs, CandidateSet); 5558 return; 5559 } 5560 5561 assert(false && "unhandled case in overloaded call candidate"); 5562 5563 // do nothing? 5564} 5565 5566/// \brief Add the overload candidates named by callee and/or found by argument 5567/// dependent lookup to the given overload set. 5568void Sema::AddOverloadedCallCandidates(UnresolvedLookupExpr *ULE, 5569 Expr **Args, unsigned NumArgs, 5570 OverloadCandidateSet &CandidateSet, 5571 bool PartialOverloading) { 5572 5573#ifndef NDEBUG 5574 // Verify that ArgumentDependentLookup is consistent with the rules 5575 // in C++0x [basic.lookup.argdep]p3: 5576 // 5577 // Let X be the lookup set produced by unqualified lookup (3.4.1) 5578 // and let Y be the lookup set produced by argument dependent 5579 // lookup (defined as follows). If X contains 5580 // 5581 // -- a declaration of a class member, or 5582 // 5583 // -- a block-scope function declaration that is not a 5584 // using-declaration, or 5585 // 5586 // -- a declaration that is neither a function or a function 5587 // template 5588 // 5589 // then Y is empty. 5590 5591 if (ULE->requiresADL()) { 5592 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(), 5593 E = ULE->decls_end(); I != E; ++I) { 5594 assert(!(*I)->getDeclContext()->isRecord()); 5595 assert(isa<UsingShadowDecl>(*I) || 5596 !(*I)->getDeclContext()->isFunctionOrMethod()); 5597 assert((*I)->getUnderlyingDecl()->isFunctionOrFunctionTemplate()); 5598 } 5599 } 5600#endif 5601 5602 // It would be nice to avoid this copy. 5603 TemplateArgumentListInfo TABuffer; 5604 const TemplateArgumentListInfo *ExplicitTemplateArgs = 0; 5605 if (ULE->hasExplicitTemplateArgs()) { 5606 ULE->copyTemplateArgumentsInto(TABuffer); 5607 ExplicitTemplateArgs = &TABuffer; 5608 } 5609 5610 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(), 5611 E = ULE->decls_end(); I != E; ++I) 5612 AddOverloadedCallCandidate(*this, I.getPair(), ExplicitTemplateArgs, 5613 Args, NumArgs, CandidateSet, 5614 PartialOverloading); 5615 5616 if (ULE->requiresADL()) 5617 AddArgumentDependentLookupCandidates(ULE->getName(), /*Operator*/ false, 5618 Args, NumArgs, 5619 ExplicitTemplateArgs, 5620 CandidateSet, 5621 PartialOverloading); 5622} 5623 5624static Sema::OwningExprResult Destroy(Sema &SemaRef, Expr *Fn, 5625 Expr **Args, unsigned NumArgs) { 5626 Fn->Destroy(SemaRef.Context); 5627 for (unsigned Arg = 0; Arg < NumArgs; ++Arg) 5628 Args[Arg]->Destroy(SemaRef.Context); 5629 return SemaRef.ExprError(); 5630} 5631 5632/// Attempts to recover from a call where no functions were found. 5633/// 5634/// Returns true if new candidates were found. 5635static Sema::OwningExprResult 5636BuildRecoveryCallExpr(Sema &SemaRef, Scope *S, Expr *Fn, 5637 UnresolvedLookupExpr *ULE, 5638 SourceLocation LParenLoc, 5639 Expr **Args, unsigned NumArgs, 5640 SourceLocation *CommaLocs, 5641 SourceLocation RParenLoc) { 5642 5643 CXXScopeSpec SS; 5644 if (ULE->getQualifier()) { 5645 SS.setScopeRep(ULE->getQualifier()); 5646 SS.setRange(ULE->getQualifierRange()); 5647 } 5648 5649 TemplateArgumentListInfo TABuffer; 5650 const TemplateArgumentListInfo *ExplicitTemplateArgs = 0; 5651 if (ULE->hasExplicitTemplateArgs()) { 5652 ULE->copyTemplateArgumentsInto(TABuffer); 5653 ExplicitTemplateArgs = &TABuffer; 5654 } 5655 5656 LookupResult R(SemaRef, ULE->getName(), ULE->getNameLoc(), 5657 Sema::LookupOrdinaryName); 5658 if (SemaRef.DiagnoseEmptyLookup(S, SS, R)) 5659 return Destroy(SemaRef, Fn, Args, NumArgs); 5660 5661 assert(!R.empty() && "lookup results empty despite recovery"); 5662 5663 // Build an implicit member call if appropriate. Just drop the 5664 // casts and such from the call, we don't really care. 5665 Sema::OwningExprResult NewFn = SemaRef.ExprError(); 5666 if ((*R.begin())->isCXXClassMember()) 5667 NewFn = SemaRef.BuildPossibleImplicitMemberExpr(SS, R, ExplicitTemplateArgs); 5668 else if (ExplicitTemplateArgs) 5669 NewFn = SemaRef.BuildTemplateIdExpr(SS, R, false, *ExplicitTemplateArgs); 5670 else 5671 NewFn = SemaRef.BuildDeclarationNameExpr(SS, R, false); 5672 5673 if (NewFn.isInvalid()) 5674 return Destroy(SemaRef, Fn, Args, NumArgs); 5675 5676 Fn->Destroy(SemaRef.Context); 5677 5678 // This shouldn't cause an infinite loop because we're giving it 5679 // an expression with non-empty lookup results, which should never 5680 // end up here. 5681 return SemaRef.ActOnCallExpr(/*Scope*/ 0, move(NewFn), LParenLoc, 5682 Sema::MultiExprArg(SemaRef, (void**) Args, NumArgs), 5683 CommaLocs, RParenLoc); 5684} 5685 5686/// ResolveOverloadedCallFn - Given the call expression that calls Fn 5687/// (which eventually refers to the declaration Func) and the call 5688/// arguments Args/NumArgs, attempt to resolve the function call down 5689/// to a specific function. If overload resolution succeeds, returns 5690/// the function declaration produced by overload 5691/// resolution. Otherwise, emits diagnostics, deletes all of the 5692/// arguments and Fn, and returns NULL. 5693Sema::OwningExprResult 5694Sema::BuildOverloadedCallExpr(Scope *S, Expr *Fn, UnresolvedLookupExpr *ULE, 5695 SourceLocation LParenLoc, 5696 Expr **Args, unsigned NumArgs, 5697 SourceLocation *CommaLocs, 5698 SourceLocation RParenLoc) { 5699#ifndef NDEBUG 5700 if (ULE->requiresADL()) { 5701 // To do ADL, we must have found an unqualified name. 5702 assert(!ULE->getQualifier() && "qualified name with ADL"); 5703 5704 // We don't perform ADL for implicit declarations of builtins. 5705 // Verify that this was correctly set up. 5706 FunctionDecl *F; 5707 if (ULE->decls_begin() + 1 == ULE->decls_end() && 5708 (F = dyn_cast<FunctionDecl>(*ULE->decls_begin())) && 5709 F->getBuiltinID() && F->isImplicit()) 5710 assert(0 && "performing ADL for builtin"); 5711 5712 // We don't perform ADL in C. 5713 assert(getLangOptions().CPlusPlus && "ADL enabled in C"); 5714 } 5715#endif 5716 5717 OverloadCandidateSet CandidateSet(Fn->getExprLoc()); 5718 5719 // Add the functions denoted by the callee to the set of candidate 5720 // functions, including those from argument-dependent lookup. 5721 AddOverloadedCallCandidates(ULE, Args, NumArgs, CandidateSet); 5722 5723 // If we found nothing, try to recover. 5724 // AddRecoveryCallCandidates diagnoses the error itself, so we just 5725 // bailout out if it fails. 5726 if (CandidateSet.empty()) 5727 return BuildRecoveryCallExpr(*this, S, Fn, ULE, LParenLoc, Args, NumArgs, 5728 CommaLocs, RParenLoc); 5729 5730 OverloadCandidateSet::iterator Best; 5731 switch (BestViableFunction(CandidateSet, Fn->getLocStart(), Best)) { 5732 case OR_Success: { 5733 FunctionDecl *FDecl = Best->Function; 5734 CheckUnresolvedLookupAccess(ULE, Best->FoundDecl); 5735 Fn = FixOverloadedFunctionReference(Fn, Best->FoundDecl, FDecl); 5736 return BuildResolvedCallExpr(Fn, FDecl, LParenLoc, Args, NumArgs, RParenLoc); 5737 } 5738 5739 case OR_No_Viable_Function: 5740 Diag(Fn->getSourceRange().getBegin(), 5741 diag::err_ovl_no_viable_function_in_call) 5742 << ULE->getName() << Fn->getSourceRange(); 5743 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 5744 break; 5745 5746 case OR_Ambiguous: 5747 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_ambiguous_call) 5748 << ULE->getName() << Fn->getSourceRange(); 5749 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, NumArgs); 5750 break; 5751 5752 case OR_Deleted: 5753 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_deleted_call) 5754 << Best->Function->isDeleted() 5755 << ULE->getName() 5756 << Fn->getSourceRange(); 5757 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 5758 break; 5759 } 5760 5761 // Overload resolution failed. Destroy all of the subexpressions and 5762 // return NULL. 5763 Fn->Destroy(Context); 5764 for (unsigned Arg = 0; Arg < NumArgs; ++Arg) 5765 Args[Arg]->Destroy(Context); 5766 return ExprError(); 5767} 5768 5769static bool IsOverloaded(const UnresolvedSetImpl &Functions) { 5770 return Functions.size() > 1 || 5771 (Functions.size() == 1 && isa<FunctionTemplateDecl>(*Functions.begin())); 5772} 5773 5774/// \brief Create a unary operation that may resolve to an overloaded 5775/// operator. 5776/// 5777/// \param OpLoc The location of the operator itself (e.g., '*'). 5778/// 5779/// \param OpcIn The UnaryOperator::Opcode that describes this 5780/// operator. 5781/// 5782/// \param Functions The set of non-member functions that will be 5783/// considered by overload resolution. The caller needs to build this 5784/// set based on the context using, e.g., 5785/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 5786/// set should not contain any member functions; those will be added 5787/// by CreateOverloadedUnaryOp(). 5788/// 5789/// \param input The input argument. 5790Sema::OwningExprResult 5791Sema::CreateOverloadedUnaryOp(SourceLocation OpLoc, unsigned OpcIn, 5792 const UnresolvedSetImpl &Fns, 5793 ExprArg input) { 5794 UnaryOperator::Opcode Opc = static_cast<UnaryOperator::Opcode>(OpcIn); 5795 Expr *Input = (Expr *)input.get(); 5796 5797 OverloadedOperatorKind Op = UnaryOperator::getOverloadedOperator(Opc); 5798 assert(Op != OO_None && "Invalid opcode for overloaded unary operator"); 5799 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 5800 5801 Expr *Args[2] = { Input, 0 }; 5802 unsigned NumArgs = 1; 5803 5804 // For post-increment and post-decrement, add the implicit '0' as 5805 // the second argument, so that we know this is a post-increment or 5806 // post-decrement. 5807 if (Opc == UnaryOperator::PostInc || Opc == UnaryOperator::PostDec) { 5808 llvm::APSInt Zero(Context.getTypeSize(Context.IntTy), false); 5809 Args[1] = new (Context) IntegerLiteral(Zero, Context.IntTy, 5810 SourceLocation()); 5811 NumArgs = 2; 5812 } 5813 5814 if (Input->isTypeDependent()) { 5815 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 5816 UnresolvedLookupExpr *Fn 5817 = UnresolvedLookupExpr::Create(Context, /*Dependent*/ true, NamingClass, 5818 0, SourceRange(), OpName, OpLoc, 5819 /*ADL*/ true, IsOverloaded(Fns)); 5820 Fn->addDecls(Fns.begin(), Fns.end()); 5821 5822 input.release(); 5823 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 5824 &Args[0], NumArgs, 5825 Context.DependentTy, 5826 OpLoc)); 5827 } 5828 5829 // Build an empty overload set. 5830 OverloadCandidateSet CandidateSet(OpLoc); 5831 5832 // Add the candidates from the given function set. 5833 AddFunctionCandidates(Fns, &Args[0], NumArgs, CandidateSet, false); 5834 5835 // Add operator candidates that are member functions. 5836 AddMemberOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 5837 5838 // Add candidates from ADL. 5839 AddArgumentDependentLookupCandidates(OpName, /*Operator*/ true, 5840 Args, NumArgs, 5841 /*ExplicitTemplateArgs*/ 0, 5842 CandidateSet); 5843 5844 // Add builtin operator candidates. 5845 AddBuiltinOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 5846 5847 // Perform overload resolution. 5848 OverloadCandidateSet::iterator Best; 5849 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 5850 case OR_Success: { 5851 // We found a built-in operator or an overloaded operator. 5852 FunctionDecl *FnDecl = Best->Function; 5853 5854 if (FnDecl) { 5855 // We matched an overloaded operator. Build a call to that 5856 // operator. 5857 5858 // Convert the arguments. 5859 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 5860 CheckMemberOperatorAccess(OpLoc, Args[0], 0, Best->FoundDecl); 5861 5862 if (PerformObjectArgumentInitialization(Input, /*Qualifier=*/0, 5863 Best->FoundDecl, Method)) 5864 return ExprError(); 5865 } else { 5866 // Convert the arguments. 5867 OwningExprResult InputInit 5868 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 5869 FnDecl->getParamDecl(0)), 5870 SourceLocation(), 5871 move(input)); 5872 if (InputInit.isInvalid()) 5873 return ExprError(); 5874 5875 input = move(InputInit); 5876 Input = (Expr *)input.get(); 5877 } 5878 5879 // Determine the result type 5880 QualType ResultTy = FnDecl->getResultType().getNonReferenceType(); 5881 5882 // Build the actual expression node. 5883 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 5884 SourceLocation()); 5885 UsualUnaryConversions(FnExpr); 5886 5887 input.release(); 5888 Args[0] = Input; 5889 ExprOwningPtr<CallExpr> TheCall(this, 5890 new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 5891 Args, NumArgs, ResultTy, OpLoc)); 5892 5893 if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall.get(), 5894 FnDecl)) 5895 return ExprError(); 5896 5897 return MaybeBindToTemporary(TheCall.release()); 5898 } else { 5899 // We matched a built-in operator. Convert the arguments, then 5900 // break out so that we will build the appropriate built-in 5901 // operator node. 5902 if (PerformImplicitConversion(Input, Best->BuiltinTypes.ParamTypes[0], 5903 Best->Conversions[0], AA_Passing)) 5904 return ExprError(); 5905 5906 break; 5907 } 5908 } 5909 5910 case OR_No_Viable_Function: 5911 // No viable function; fall through to handling this as a 5912 // built-in operator, which will produce an error message for us. 5913 break; 5914 5915 case OR_Ambiguous: 5916 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 5917 << UnaryOperator::getOpcodeStr(Opc) 5918 << Input->getSourceRange(); 5919 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, NumArgs, 5920 UnaryOperator::getOpcodeStr(Opc), OpLoc); 5921 return ExprError(); 5922 5923 case OR_Deleted: 5924 Diag(OpLoc, diag::err_ovl_deleted_oper) 5925 << Best->Function->isDeleted() 5926 << UnaryOperator::getOpcodeStr(Opc) 5927 << Input->getSourceRange(); 5928 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 5929 return ExprError(); 5930 } 5931 5932 // Either we found no viable overloaded operator or we matched a 5933 // built-in operator. In either case, fall through to trying to 5934 // build a built-in operation. 5935 input.release(); 5936 return CreateBuiltinUnaryOp(OpLoc, Opc, Owned(Input)); 5937} 5938 5939/// \brief Create a binary operation that may resolve to an overloaded 5940/// operator. 5941/// 5942/// \param OpLoc The location of the operator itself (e.g., '+'). 5943/// 5944/// \param OpcIn The BinaryOperator::Opcode that describes this 5945/// operator. 5946/// 5947/// \param Functions The set of non-member functions that will be 5948/// considered by overload resolution. The caller needs to build this 5949/// set based on the context using, e.g., 5950/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 5951/// set should not contain any member functions; those will be added 5952/// by CreateOverloadedBinOp(). 5953/// 5954/// \param LHS Left-hand argument. 5955/// \param RHS Right-hand argument. 5956Sema::OwningExprResult 5957Sema::CreateOverloadedBinOp(SourceLocation OpLoc, 5958 unsigned OpcIn, 5959 const UnresolvedSetImpl &Fns, 5960 Expr *LHS, Expr *RHS) { 5961 Expr *Args[2] = { LHS, RHS }; 5962 LHS=RHS=0; //Please use only Args instead of LHS/RHS couple 5963 5964 BinaryOperator::Opcode Opc = static_cast<BinaryOperator::Opcode>(OpcIn); 5965 OverloadedOperatorKind Op = BinaryOperator::getOverloadedOperator(Opc); 5966 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 5967 5968 // If either side is type-dependent, create an appropriate dependent 5969 // expression. 5970 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 5971 if (Fns.empty()) { 5972 // If there are no functions to store, just build a dependent 5973 // BinaryOperator or CompoundAssignment. 5974 if (Opc <= BinaryOperator::Assign || Opc > BinaryOperator::OrAssign) 5975 return Owned(new (Context) BinaryOperator(Args[0], Args[1], Opc, 5976 Context.DependentTy, OpLoc)); 5977 5978 return Owned(new (Context) CompoundAssignOperator(Args[0], Args[1], Opc, 5979 Context.DependentTy, 5980 Context.DependentTy, 5981 Context.DependentTy, 5982 OpLoc)); 5983 } 5984 5985 // FIXME: save results of ADL from here? 5986 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 5987 UnresolvedLookupExpr *Fn 5988 = UnresolvedLookupExpr::Create(Context, /*Dependent*/ true, NamingClass, 5989 0, SourceRange(), OpName, OpLoc, 5990 /*ADL*/ true, IsOverloaded(Fns)); 5991 5992 Fn->addDecls(Fns.begin(), Fns.end()); 5993 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 5994 Args, 2, 5995 Context.DependentTy, 5996 OpLoc)); 5997 } 5998 5999 // If this is the .* operator, which is not overloadable, just 6000 // create a built-in binary operator. 6001 if (Opc == BinaryOperator::PtrMemD) 6002 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 6003 6004 // If this is the assignment operator, we only perform overload resolution 6005 // if the left-hand side is a class or enumeration type. This is actually 6006 // a hack. The standard requires that we do overload resolution between the 6007 // various built-in candidates, but as DR507 points out, this can lead to 6008 // problems. So we do it this way, which pretty much follows what GCC does. 6009 // Note that we go the traditional code path for compound assignment forms. 6010 if (Opc==BinaryOperator::Assign && !Args[0]->getType()->isOverloadableType()) 6011 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 6012 6013 // Build an empty overload set. 6014 OverloadCandidateSet CandidateSet(OpLoc); 6015 6016 // Add the candidates from the given function set. 6017 AddFunctionCandidates(Fns, Args, 2, CandidateSet, false); 6018 6019 // Add operator candidates that are member functions. 6020 AddMemberOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 6021 6022 // Add candidates from ADL. 6023 AddArgumentDependentLookupCandidates(OpName, /*Operator*/ true, 6024 Args, 2, 6025 /*ExplicitTemplateArgs*/ 0, 6026 CandidateSet); 6027 6028 // Add builtin operator candidates. 6029 AddBuiltinOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 6030 6031 // Perform overload resolution. 6032 OverloadCandidateSet::iterator Best; 6033 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 6034 case OR_Success: { 6035 // We found a built-in operator or an overloaded operator. 6036 FunctionDecl *FnDecl = Best->Function; 6037 6038 if (FnDecl) { 6039 // We matched an overloaded operator. Build a call to that 6040 // operator. 6041 6042 // Convert the arguments. 6043 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 6044 // Best->Access is only meaningful for class members. 6045 CheckMemberOperatorAccess(OpLoc, Args[0], Args[1], Best->FoundDecl); 6046 6047 OwningExprResult Arg1 6048 = PerformCopyInitialization( 6049 InitializedEntity::InitializeParameter( 6050 FnDecl->getParamDecl(0)), 6051 SourceLocation(), 6052 Owned(Args[1])); 6053 if (Arg1.isInvalid()) 6054 return ExprError(); 6055 6056 if (PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/0, 6057 Best->FoundDecl, Method)) 6058 return ExprError(); 6059 6060 Args[1] = RHS = Arg1.takeAs<Expr>(); 6061 } else { 6062 // Convert the arguments. 6063 OwningExprResult Arg0 6064 = PerformCopyInitialization( 6065 InitializedEntity::InitializeParameter( 6066 FnDecl->getParamDecl(0)), 6067 SourceLocation(), 6068 Owned(Args[0])); 6069 if (Arg0.isInvalid()) 6070 return ExprError(); 6071 6072 OwningExprResult Arg1 6073 = PerformCopyInitialization( 6074 InitializedEntity::InitializeParameter( 6075 FnDecl->getParamDecl(1)), 6076 SourceLocation(), 6077 Owned(Args[1])); 6078 if (Arg1.isInvalid()) 6079 return ExprError(); 6080 Args[0] = LHS = Arg0.takeAs<Expr>(); 6081 Args[1] = RHS = Arg1.takeAs<Expr>(); 6082 } 6083 6084 // Determine the result type 6085 QualType ResultTy 6086 = FnDecl->getType()->getAs<FunctionType>()->getResultType(); 6087 ResultTy = ResultTy.getNonReferenceType(); 6088 6089 // Build the actual expression node. 6090 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 6091 OpLoc); 6092 UsualUnaryConversions(FnExpr); 6093 6094 ExprOwningPtr<CXXOperatorCallExpr> 6095 TheCall(this, new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 6096 Args, 2, ResultTy, 6097 OpLoc)); 6098 6099 if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall.get(), 6100 FnDecl)) 6101 return ExprError(); 6102 6103 return MaybeBindToTemporary(TheCall.release()); 6104 } else { 6105 // We matched a built-in operator. Convert the arguments, then 6106 // break out so that we will build the appropriate built-in 6107 // operator node. 6108 if (PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 6109 Best->Conversions[0], AA_Passing) || 6110 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 6111 Best->Conversions[1], AA_Passing)) 6112 return ExprError(); 6113 6114 break; 6115 } 6116 } 6117 6118 case OR_No_Viable_Function: { 6119 // C++ [over.match.oper]p9: 6120 // If the operator is the operator , [...] and there are no 6121 // viable functions, then the operator is assumed to be the 6122 // built-in operator and interpreted according to clause 5. 6123 if (Opc == BinaryOperator::Comma) 6124 break; 6125 6126 // For class as left operand for assignment or compound assigment operator 6127 // do not fall through to handling in built-in, but report that no overloaded 6128 // assignment operator found 6129 OwningExprResult Result = ExprError(); 6130 if (Args[0]->getType()->isRecordType() && 6131 Opc >= BinaryOperator::Assign && Opc <= BinaryOperator::OrAssign) { 6132 Diag(OpLoc, diag::err_ovl_no_viable_oper) 6133 << BinaryOperator::getOpcodeStr(Opc) 6134 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 6135 } else { 6136 // No viable function; try to create a built-in operation, which will 6137 // produce an error. Then, show the non-viable candidates. 6138 Result = CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 6139 } 6140 assert(Result.isInvalid() && 6141 "C++ binary operator overloading is missing candidates!"); 6142 if (Result.isInvalid()) 6143 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2, 6144 BinaryOperator::getOpcodeStr(Opc), OpLoc); 6145 return move(Result); 6146 } 6147 6148 case OR_Ambiguous: 6149 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 6150 << BinaryOperator::getOpcodeStr(Opc) 6151 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 6152 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, 2, 6153 BinaryOperator::getOpcodeStr(Opc), OpLoc); 6154 return ExprError(); 6155 6156 case OR_Deleted: 6157 Diag(OpLoc, diag::err_ovl_deleted_oper) 6158 << Best->Function->isDeleted() 6159 << BinaryOperator::getOpcodeStr(Opc) 6160 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 6161 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2); 6162 return ExprError(); 6163 } 6164 6165 // We matched a built-in operator; build it. 6166 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 6167} 6168 6169Action::OwningExprResult 6170Sema::CreateOverloadedArraySubscriptExpr(SourceLocation LLoc, 6171 SourceLocation RLoc, 6172 ExprArg Base, ExprArg Idx) { 6173 Expr *Args[2] = { static_cast<Expr*>(Base.get()), 6174 static_cast<Expr*>(Idx.get()) }; 6175 DeclarationName OpName = 6176 Context.DeclarationNames.getCXXOperatorName(OO_Subscript); 6177 6178 // If either side is type-dependent, create an appropriate dependent 6179 // expression. 6180 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 6181 6182 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 6183 UnresolvedLookupExpr *Fn 6184 = UnresolvedLookupExpr::Create(Context, /*Dependent*/ true, NamingClass, 6185 0, SourceRange(), OpName, LLoc, 6186 /*ADL*/ true, /*Overloaded*/ false); 6187 // Can't add any actual overloads yet 6188 6189 Base.release(); 6190 Idx.release(); 6191 return Owned(new (Context) CXXOperatorCallExpr(Context, OO_Subscript, Fn, 6192 Args, 2, 6193 Context.DependentTy, 6194 RLoc)); 6195 } 6196 6197 // Build an empty overload set. 6198 OverloadCandidateSet CandidateSet(LLoc); 6199 6200 // Subscript can only be overloaded as a member function. 6201 6202 // Add operator candidates that are member functions. 6203 AddMemberOperatorCandidates(OO_Subscript, LLoc, Args, 2, CandidateSet); 6204 6205 // Add builtin operator candidates. 6206 AddBuiltinOperatorCandidates(OO_Subscript, LLoc, Args, 2, CandidateSet); 6207 6208 // Perform overload resolution. 6209 OverloadCandidateSet::iterator Best; 6210 switch (BestViableFunction(CandidateSet, LLoc, Best)) { 6211 case OR_Success: { 6212 // We found a built-in operator or an overloaded operator. 6213 FunctionDecl *FnDecl = Best->Function; 6214 6215 if (FnDecl) { 6216 // We matched an overloaded operator. Build a call to that 6217 // operator. 6218 6219 CheckMemberOperatorAccess(LLoc, Args[0], Args[1], Best->FoundDecl); 6220 6221 // Convert the arguments. 6222 CXXMethodDecl *Method = cast<CXXMethodDecl>(FnDecl); 6223 if (PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/0, 6224 Best->FoundDecl, Method)) 6225 return ExprError(); 6226 6227 // Convert the arguments. 6228 OwningExprResult InputInit 6229 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 6230 FnDecl->getParamDecl(0)), 6231 SourceLocation(), 6232 Owned(Args[1])); 6233 if (InputInit.isInvalid()) 6234 return ExprError(); 6235 6236 Args[1] = InputInit.takeAs<Expr>(); 6237 6238 // Determine the result type 6239 QualType ResultTy 6240 = FnDecl->getType()->getAs<FunctionType>()->getResultType(); 6241 ResultTy = ResultTy.getNonReferenceType(); 6242 6243 // Build the actual expression node. 6244 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 6245 LLoc); 6246 UsualUnaryConversions(FnExpr); 6247 6248 Base.release(); 6249 Idx.release(); 6250 ExprOwningPtr<CXXOperatorCallExpr> 6251 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Subscript, 6252 FnExpr, Args, 2, 6253 ResultTy, RLoc)); 6254 6255 if (CheckCallReturnType(FnDecl->getResultType(), LLoc, TheCall.get(), 6256 FnDecl)) 6257 return ExprError(); 6258 6259 return MaybeBindToTemporary(TheCall.release()); 6260 } else { 6261 // We matched a built-in operator. Convert the arguments, then 6262 // break out so that we will build the appropriate built-in 6263 // operator node. 6264 if (PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 6265 Best->Conversions[0], AA_Passing) || 6266 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 6267 Best->Conversions[1], AA_Passing)) 6268 return ExprError(); 6269 6270 break; 6271 } 6272 } 6273 6274 case OR_No_Viable_Function: { 6275 if (CandidateSet.empty()) 6276 Diag(LLoc, diag::err_ovl_no_oper) 6277 << Args[0]->getType() << /*subscript*/ 0 6278 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 6279 else 6280 Diag(LLoc, diag::err_ovl_no_viable_subscript) 6281 << Args[0]->getType() 6282 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 6283 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2, 6284 "[]", LLoc); 6285 return ExprError(); 6286 } 6287 6288 case OR_Ambiguous: 6289 Diag(LLoc, diag::err_ovl_ambiguous_oper) 6290 << "[]" << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 6291 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, 2, 6292 "[]", LLoc); 6293 return ExprError(); 6294 6295 case OR_Deleted: 6296 Diag(LLoc, diag::err_ovl_deleted_oper) 6297 << Best->Function->isDeleted() << "[]" 6298 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 6299 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2, 6300 "[]", LLoc); 6301 return ExprError(); 6302 } 6303 6304 // We matched a built-in operator; build it. 6305 Base.release(); 6306 Idx.release(); 6307 return CreateBuiltinArraySubscriptExpr(Owned(Args[0]), LLoc, 6308 Owned(Args[1]), RLoc); 6309} 6310 6311/// BuildCallToMemberFunction - Build a call to a member 6312/// function. MemExpr is the expression that refers to the member 6313/// function (and includes the object parameter), Args/NumArgs are the 6314/// arguments to the function call (not including the object 6315/// parameter). The caller needs to validate that the member 6316/// expression refers to a member function or an overloaded member 6317/// function. 6318Sema::OwningExprResult 6319Sema::BuildCallToMemberFunction(Scope *S, Expr *MemExprE, 6320 SourceLocation LParenLoc, Expr **Args, 6321 unsigned NumArgs, SourceLocation *CommaLocs, 6322 SourceLocation RParenLoc) { 6323 // Dig out the member expression. This holds both the object 6324 // argument and the member function we're referring to. 6325 Expr *NakedMemExpr = MemExprE->IgnoreParens(); 6326 6327 MemberExpr *MemExpr; 6328 CXXMethodDecl *Method = 0; 6329 DeclAccessPair FoundDecl = DeclAccessPair::make(0, AS_public); 6330 NestedNameSpecifier *Qualifier = 0; 6331 if (isa<MemberExpr>(NakedMemExpr)) { 6332 MemExpr = cast<MemberExpr>(NakedMemExpr); 6333 Method = cast<CXXMethodDecl>(MemExpr->getMemberDecl()); 6334 FoundDecl = MemExpr->getFoundDecl(); 6335 Qualifier = MemExpr->getQualifier(); 6336 } else { 6337 UnresolvedMemberExpr *UnresExpr = cast<UnresolvedMemberExpr>(NakedMemExpr); 6338 Qualifier = UnresExpr->getQualifier(); 6339 6340 QualType ObjectType = UnresExpr->getBaseType(); 6341 6342 // Add overload candidates 6343 OverloadCandidateSet CandidateSet(UnresExpr->getMemberLoc()); 6344 6345 // FIXME: avoid copy. 6346 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 6347 if (UnresExpr->hasExplicitTemplateArgs()) { 6348 UnresExpr->copyTemplateArgumentsInto(TemplateArgsBuffer); 6349 TemplateArgs = &TemplateArgsBuffer; 6350 } 6351 6352 for (UnresolvedMemberExpr::decls_iterator I = UnresExpr->decls_begin(), 6353 E = UnresExpr->decls_end(); I != E; ++I) { 6354 6355 NamedDecl *Func = *I; 6356 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(Func->getDeclContext()); 6357 if (isa<UsingShadowDecl>(Func)) 6358 Func = cast<UsingShadowDecl>(Func)->getTargetDecl(); 6359 6360 if ((Method = dyn_cast<CXXMethodDecl>(Func))) { 6361 // If explicit template arguments were provided, we can't call a 6362 // non-template member function. 6363 if (TemplateArgs) 6364 continue; 6365 6366 AddMethodCandidate(Method, I.getPair(), ActingDC, ObjectType, 6367 Args, NumArgs, 6368 CandidateSet, /*SuppressUserConversions=*/false); 6369 } else { 6370 AddMethodTemplateCandidate(cast<FunctionTemplateDecl>(Func), 6371 I.getPair(), ActingDC, TemplateArgs, 6372 ObjectType, Args, NumArgs, 6373 CandidateSet, 6374 /*SuppressUsedConversions=*/false); 6375 } 6376 } 6377 6378 DeclarationName DeclName = UnresExpr->getMemberName(); 6379 6380 OverloadCandidateSet::iterator Best; 6381 switch (BestViableFunction(CandidateSet, UnresExpr->getLocStart(), Best)) { 6382 case OR_Success: 6383 Method = cast<CXXMethodDecl>(Best->Function); 6384 FoundDecl = Best->FoundDecl; 6385 CheckUnresolvedMemberAccess(UnresExpr, Best->FoundDecl); 6386 break; 6387 6388 case OR_No_Viable_Function: 6389 Diag(UnresExpr->getMemberLoc(), 6390 diag::err_ovl_no_viable_member_function_in_call) 6391 << DeclName << MemExprE->getSourceRange(); 6392 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6393 // FIXME: Leaking incoming expressions! 6394 return ExprError(); 6395 6396 case OR_Ambiguous: 6397 Diag(UnresExpr->getMemberLoc(), diag::err_ovl_ambiguous_member_call) 6398 << DeclName << MemExprE->getSourceRange(); 6399 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6400 // FIXME: Leaking incoming expressions! 6401 return ExprError(); 6402 6403 case OR_Deleted: 6404 Diag(UnresExpr->getMemberLoc(), diag::err_ovl_deleted_member_call) 6405 << Best->Function->isDeleted() 6406 << DeclName << MemExprE->getSourceRange(); 6407 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6408 // FIXME: Leaking incoming expressions! 6409 return ExprError(); 6410 } 6411 6412 MemExprE = FixOverloadedFunctionReference(MemExprE, FoundDecl, Method); 6413 6414 // If overload resolution picked a static member, build a 6415 // non-member call based on that function. 6416 if (Method->isStatic()) { 6417 return BuildResolvedCallExpr(MemExprE, Method, LParenLoc, 6418 Args, NumArgs, RParenLoc); 6419 } 6420 6421 MemExpr = cast<MemberExpr>(MemExprE->IgnoreParens()); 6422 } 6423 6424 assert(Method && "Member call to something that isn't a method?"); 6425 ExprOwningPtr<CXXMemberCallExpr> 6426 TheCall(this, new (Context) CXXMemberCallExpr(Context, MemExprE, Args, 6427 NumArgs, 6428 Method->getResultType().getNonReferenceType(), 6429 RParenLoc)); 6430 6431 // Check for a valid return type. 6432 if (CheckCallReturnType(Method->getResultType(), MemExpr->getMemberLoc(), 6433 TheCall.get(), Method)) 6434 return ExprError(); 6435 6436 // Convert the object argument (for a non-static member function call). 6437 // We only need to do this if there was actually an overload; otherwise 6438 // it was done at lookup. 6439 Expr *ObjectArg = MemExpr->getBase(); 6440 if (!Method->isStatic() && 6441 PerformObjectArgumentInitialization(ObjectArg, Qualifier, 6442 FoundDecl, Method)) 6443 return ExprError(); 6444 MemExpr->setBase(ObjectArg); 6445 6446 // Convert the rest of the arguments 6447 const FunctionProtoType *Proto = cast<FunctionProtoType>(Method->getType()); 6448 if (ConvertArgumentsForCall(&*TheCall, MemExpr, Method, Proto, Args, NumArgs, 6449 RParenLoc)) 6450 return ExprError(); 6451 6452 if (CheckFunctionCall(Method, TheCall.get())) 6453 return ExprError(); 6454 6455 return MaybeBindToTemporary(TheCall.release()); 6456} 6457 6458/// BuildCallToObjectOfClassType - Build a call to an object of class 6459/// type (C++ [over.call.object]), which can end up invoking an 6460/// overloaded function call operator (@c operator()) or performing a 6461/// user-defined conversion on the object argument. 6462Sema::ExprResult 6463Sema::BuildCallToObjectOfClassType(Scope *S, Expr *Object, 6464 SourceLocation LParenLoc, 6465 Expr **Args, unsigned NumArgs, 6466 SourceLocation *CommaLocs, 6467 SourceLocation RParenLoc) { 6468 assert(Object->getType()->isRecordType() && "Requires object type argument"); 6469 const RecordType *Record = Object->getType()->getAs<RecordType>(); 6470 6471 // C++ [over.call.object]p1: 6472 // If the primary-expression E in the function call syntax 6473 // evaluates to a class object of type "cv T", then the set of 6474 // candidate functions includes at least the function call 6475 // operators of T. The function call operators of T are obtained by 6476 // ordinary lookup of the name operator() in the context of 6477 // (E).operator(). 6478 OverloadCandidateSet CandidateSet(LParenLoc); 6479 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Call); 6480 6481 if (RequireCompleteType(LParenLoc, Object->getType(), 6482 PDiag(diag::err_incomplete_object_call) 6483 << Object->getSourceRange())) 6484 return true; 6485 6486 LookupResult R(*this, OpName, LParenLoc, LookupOrdinaryName); 6487 LookupQualifiedName(R, Record->getDecl()); 6488 R.suppressDiagnostics(); 6489 6490 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 6491 Oper != OperEnd; ++Oper) { 6492 AddMethodCandidate(Oper.getPair(), Object->getType(), 6493 Args, NumArgs, CandidateSet, 6494 /*SuppressUserConversions=*/ false); 6495 } 6496 6497 // C++ [over.call.object]p2: 6498 // In addition, for each conversion function declared in T of the 6499 // form 6500 // 6501 // operator conversion-type-id () cv-qualifier; 6502 // 6503 // where cv-qualifier is the same cv-qualification as, or a 6504 // greater cv-qualification than, cv, and where conversion-type-id 6505 // denotes the type "pointer to function of (P1,...,Pn) returning 6506 // R", or the type "reference to pointer to function of 6507 // (P1,...,Pn) returning R", or the type "reference to function 6508 // of (P1,...,Pn) returning R", a surrogate call function [...] 6509 // is also considered as a candidate function. Similarly, 6510 // surrogate call functions are added to the set of candidate 6511 // functions for each conversion function declared in an 6512 // accessible base class provided the function is not hidden 6513 // within T by another intervening declaration. 6514 const UnresolvedSetImpl *Conversions 6515 = cast<CXXRecordDecl>(Record->getDecl())->getVisibleConversionFunctions(); 6516 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 6517 E = Conversions->end(); I != E; ++I) { 6518 NamedDecl *D = *I; 6519 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext()); 6520 if (isa<UsingShadowDecl>(D)) 6521 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 6522 6523 // Skip over templated conversion functions; they aren't 6524 // surrogates. 6525 if (isa<FunctionTemplateDecl>(D)) 6526 continue; 6527 6528 CXXConversionDecl *Conv = cast<CXXConversionDecl>(D); 6529 6530 // Strip the reference type (if any) and then the pointer type (if 6531 // any) to get down to what might be a function type. 6532 QualType ConvType = Conv->getConversionType().getNonReferenceType(); 6533 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 6534 ConvType = ConvPtrType->getPointeeType(); 6535 6536 if (const FunctionProtoType *Proto = ConvType->getAs<FunctionProtoType>()) 6537 AddSurrogateCandidate(Conv, I.getPair(), ActingContext, Proto, 6538 Object->getType(), Args, NumArgs, 6539 CandidateSet); 6540 } 6541 6542 // Perform overload resolution. 6543 OverloadCandidateSet::iterator Best; 6544 switch (BestViableFunction(CandidateSet, Object->getLocStart(), Best)) { 6545 case OR_Success: 6546 // Overload resolution succeeded; we'll build the appropriate call 6547 // below. 6548 break; 6549 6550 case OR_No_Viable_Function: 6551 if (CandidateSet.empty()) 6552 Diag(Object->getSourceRange().getBegin(), diag::err_ovl_no_oper) 6553 << Object->getType() << /*call*/ 1 6554 << Object->getSourceRange(); 6555 else 6556 Diag(Object->getSourceRange().getBegin(), 6557 diag::err_ovl_no_viable_object_call) 6558 << Object->getType() << Object->getSourceRange(); 6559 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6560 break; 6561 6562 case OR_Ambiguous: 6563 Diag(Object->getSourceRange().getBegin(), 6564 diag::err_ovl_ambiguous_object_call) 6565 << Object->getType() << Object->getSourceRange(); 6566 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, NumArgs); 6567 break; 6568 6569 case OR_Deleted: 6570 Diag(Object->getSourceRange().getBegin(), 6571 diag::err_ovl_deleted_object_call) 6572 << Best->Function->isDeleted() 6573 << Object->getType() << Object->getSourceRange(); 6574 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6575 break; 6576 } 6577 6578 if (Best == CandidateSet.end()) { 6579 // We had an error; delete all of the subexpressions and return 6580 // the error. 6581 Object->Destroy(Context); 6582 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 6583 Args[ArgIdx]->Destroy(Context); 6584 return true; 6585 } 6586 6587 if (Best->Function == 0) { 6588 // Since there is no function declaration, this is one of the 6589 // surrogate candidates. Dig out the conversion function. 6590 CXXConversionDecl *Conv 6591 = cast<CXXConversionDecl>( 6592 Best->Conversions[0].UserDefined.ConversionFunction); 6593 6594 CheckMemberOperatorAccess(LParenLoc, Object, 0, Best->FoundDecl); 6595 6596 // We selected one of the surrogate functions that converts the 6597 // object parameter to a function pointer. Perform the conversion 6598 // on the object argument, then let ActOnCallExpr finish the job. 6599 6600 // Create an implicit member expr to refer to the conversion operator. 6601 // and then call it. 6602 CXXMemberCallExpr *CE = BuildCXXMemberCallExpr(Object, Best->FoundDecl, 6603 Conv); 6604 6605 return ActOnCallExpr(S, ExprArg(*this, CE), LParenLoc, 6606 MultiExprArg(*this, (ExprTy**)Args, NumArgs), 6607 CommaLocs, RParenLoc).result(); 6608 } 6609 6610 CheckMemberOperatorAccess(LParenLoc, Object, 0, Best->FoundDecl); 6611 6612 // We found an overloaded operator(). Build a CXXOperatorCallExpr 6613 // that calls this method, using Object for the implicit object 6614 // parameter and passing along the remaining arguments. 6615 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 6616 const FunctionProtoType *Proto = Method->getType()->getAs<FunctionProtoType>(); 6617 6618 unsigned NumArgsInProto = Proto->getNumArgs(); 6619 unsigned NumArgsToCheck = NumArgs; 6620 6621 // Build the full argument list for the method call (the 6622 // implicit object parameter is placed at the beginning of the 6623 // list). 6624 Expr **MethodArgs; 6625 if (NumArgs < NumArgsInProto) { 6626 NumArgsToCheck = NumArgsInProto; 6627 MethodArgs = new Expr*[NumArgsInProto + 1]; 6628 } else { 6629 MethodArgs = new Expr*[NumArgs + 1]; 6630 } 6631 MethodArgs[0] = Object; 6632 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 6633 MethodArgs[ArgIdx + 1] = Args[ArgIdx]; 6634 6635 Expr *NewFn = new (Context) DeclRefExpr(Method, Method->getType(), 6636 SourceLocation()); 6637 UsualUnaryConversions(NewFn); 6638 6639 // Once we've built TheCall, all of the expressions are properly 6640 // owned. 6641 QualType ResultTy = Method->getResultType().getNonReferenceType(); 6642 ExprOwningPtr<CXXOperatorCallExpr> 6643 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Call, NewFn, 6644 MethodArgs, NumArgs + 1, 6645 ResultTy, RParenLoc)); 6646 delete [] MethodArgs; 6647 6648 if (CheckCallReturnType(Method->getResultType(), LParenLoc, TheCall.get(), 6649 Method)) 6650 return true; 6651 6652 // We may have default arguments. If so, we need to allocate more 6653 // slots in the call for them. 6654 if (NumArgs < NumArgsInProto) 6655 TheCall->setNumArgs(Context, NumArgsInProto + 1); 6656 else if (NumArgs > NumArgsInProto) 6657 NumArgsToCheck = NumArgsInProto; 6658 6659 bool IsError = false; 6660 6661 // Initialize the implicit object parameter. 6662 IsError |= PerformObjectArgumentInitialization(Object, /*Qualifier=*/0, 6663 Best->FoundDecl, Method); 6664 TheCall->setArg(0, Object); 6665 6666 6667 // Check the argument types. 6668 for (unsigned i = 0; i != NumArgsToCheck; i++) { 6669 Expr *Arg; 6670 if (i < NumArgs) { 6671 Arg = Args[i]; 6672 6673 // Pass the argument. 6674 6675 OwningExprResult InputInit 6676 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 6677 Method->getParamDecl(i)), 6678 SourceLocation(), Owned(Arg)); 6679 6680 IsError |= InputInit.isInvalid(); 6681 Arg = InputInit.takeAs<Expr>(); 6682 } else { 6683 OwningExprResult DefArg 6684 = BuildCXXDefaultArgExpr(LParenLoc, Method, Method->getParamDecl(i)); 6685 if (DefArg.isInvalid()) { 6686 IsError = true; 6687 break; 6688 } 6689 6690 Arg = DefArg.takeAs<Expr>(); 6691 } 6692 6693 TheCall->setArg(i + 1, Arg); 6694 } 6695 6696 // If this is a variadic call, handle args passed through "...". 6697 if (Proto->isVariadic()) { 6698 // Promote the arguments (C99 6.5.2.2p7). 6699 for (unsigned i = NumArgsInProto; i != NumArgs; i++) { 6700 Expr *Arg = Args[i]; 6701 IsError |= DefaultVariadicArgumentPromotion(Arg, VariadicMethod); 6702 TheCall->setArg(i + 1, Arg); 6703 } 6704 } 6705 6706 if (IsError) return true; 6707 6708 if (CheckFunctionCall(Method, TheCall.get())) 6709 return true; 6710 6711 return MaybeBindToTemporary(TheCall.release()).result(); 6712} 6713 6714/// BuildOverloadedArrowExpr - Build a call to an overloaded @c operator-> 6715/// (if one exists), where @c Base is an expression of class type and 6716/// @c Member is the name of the member we're trying to find. 6717Sema::OwningExprResult 6718Sema::BuildOverloadedArrowExpr(Scope *S, ExprArg BaseIn, SourceLocation OpLoc) { 6719 Expr *Base = static_cast<Expr *>(BaseIn.get()); 6720 assert(Base->getType()->isRecordType() && "left-hand side must have class type"); 6721 6722 SourceLocation Loc = Base->getExprLoc(); 6723 6724 // C++ [over.ref]p1: 6725 // 6726 // [...] An expression x->m is interpreted as (x.operator->())->m 6727 // for a class object x of type T if T::operator->() exists and if 6728 // the operator is selected as the best match function by the 6729 // overload resolution mechanism (13.3). 6730 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Arrow); 6731 OverloadCandidateSet CandidateSet(Loc); 6732 const RecordType *BaseRecord = Base->getType()->getAs<RecordType>(); 6733 6734 if (RequireCompleteType(Loc, Base->getType(), 6735 PDiag(diag::err_typecheck_incomplete_tag) 6736 << Base->getSourceRange())) 6737 return ExprError(); 6738 6739 LookupResult R(*this, OpName, OpLoc, LookupOrdinaryName); 6740 LookupQualifiedName(R, BaseRecord->getDecl()); 6741 R.suppressDiagnostics(); 6742 6743 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 6744 Oper != OperEnd; ++Oper) { 6745 AddMethodCandidate(Oper.getPair(), Base->getType(), 0, 0, CandidateSet, 6746 /*SuppressUserConversions=*/false); 6747 } 6748 6749 // Perform overload resolution. 6750 OverloadCandidateSet::iterator Best; 6751 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 6752 case OR_Success: 6753 // Overload resolution succeeded; we'll build the call below. 6754 break; 6755 6756 case OR_No_Viable_Function: 6757 if (CandidateSet.empty()) 6758 Diag(OpLoc, diag::err_typecheck_member_reference_arrow) 6759 << Base->getType() << Base->getSourceRange(); 6760 else 6761 Diag(OpLoc, diag::err_ovl_no_viable_oper) 6762 << "operator->" << Base->getSourceRange(); 6763 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, &Base, 1); 6764 return ExprError(); 6765 6766 case OR_Ambiguous: 6767 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 6768 << "->" << Base->getSourceRange(); 6769 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, &Base, 1); 6770 return ExprError(); 6771 6772 case OR_Deleted: 6773 Diag(OpLoc, diag::err_ovl_deleted_oper) 6774 << Best->Function->isDeleted() 6775 << "->" << Base->getSourceRange(); 6776 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, &Base, 1); 6777 return ExprError(); 6778 } 6779 6780 CheckMemberOperatorAccess(OpLoc, Base, 0, Best->FoundDecl); 6781 6782 // Convert the object parameter. 6783 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 6784 if (PerformObjectArgumentInitialization(Base, /*Qualifier=*/0, 6785 Best->FoundDecl, Method)) 6786 return ExprError(); 6787 6788 // No concerns about early exits now. 6789 BaseIn.release(); 6790 6791 // Build the operator call. 6792 Expr *FnExpr = new (Context) DeclRefExpr(Method, Method->getType(), 6793 SourceLocation()); 6794 UsualUnaryConversions(FnExpr); 6795 6796 QualType ResultTy = Method->getResultType().getNonReferenceType(); 6797 ExprOwningPtr<CXXOperatorCallExpr> 6798 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Arrow, FnExpr, 6799 &Base, 1, ResultTy, OpLoc)); 6800 6801 if (CheckCallReturnType(Method->getResultType(), OpLoc, TheCall.get(), 6802 Method)) 6803 return ExprError(); 6804 return move(TheCall); 6805} 6806 6807/// FixOverloadedFunctionReference - E is an expression that refers to 6808/// a C++ overloaded function (possibly with some parentheses and 6809/// perhaps a '&' around it). We have resolved the overloaded function 6810/// to the function declaration Fn, so patch up the expression E to 6811/// refer (possibly indirectly) to Fn. Returns the new expr. 6812Expr *Sema::FixOverloadedFunctionReference(Expr *E, DeclAccessPair Found, 6813 FunctionDecl *Fn) { 6814 if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) { 6815 Expr *SubExpr = FixOverloadedFunctionReference(PE->getSubExpr(), 6816 Found, Fn); 6817 if (SubExpr == PE->getSubExpr()) 6818 return PE->Retain(); 6819 6820 return new (Context) ParenExpr(PE->getLParen(), PE->getRParen(), SubExpr); 6821 } 6822 6823 if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) { 6824 Expr *SubExpr = FixOverloadedFunctionReference(ICE->getSubExpr(), 6825 Found, Fn); 6826 assert(Context.hasSameType(ICE->getSubExpr()->getType(), 6827 SubExpr->getType()) && 6828 "Implicit cast type cannot be determined from overload"); 6829 if (SubExpr == ICE->getSubExpr()) 6830 return ICE->Retain(); 6831 6832 return new (Context) ImplicitCastExpr(ICE->getType(), 6833 ICE->getCastKind(), 6834 SubExpr, 6835 ICE->isLvalueCast()); 6836 } 6837 6838 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(E)) { 6839 assert(UnOp->getOpcode() == UnaryOperator::AddrOf && 6840 "Can only take the address of an overloaded function"); 6841 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 6842 if (Method->isStatic()) { 6843 // Do nothing: static member functions aren't any different 6844 // from non-member functions. 6845 } else { 6846 // Fix the sub expression, which really has to be an 6847 // UnresolvedLookupExpr holding an overloaded member function 6848 // or template. 6849 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(), 6850 Found, Fn); 6851 if (SubExpr == UnOp->getSubExpr()) 6852 return UnOp->Retain(); 6853 6854 assert(isa<DeclRefExpr>(SubExpr) 6855 && "fixed to something other than a decl ref"); 6856 assert(cast<DeclRefExpr>(SubExpr)->getQualifier() 6857 && "fixed to a member ref with no nested name qualifier"); 6858 6859 // We have taken the address of a pointer to member 6860 // function. Perform the computation here so that we get the 6861 // appropriate pointer to member type. 6862 QualType ClassType 6863 = Context.getTypeDeclType(cast<RecordDecl>(Method->getDeclContext())); 6864 QualType MemPtrType 6865 = Context.getMemberPointerType(Fn->getType(), ClassType.getTypePtr()); 6866 6867 return new (Context) UnaryOperator(SubExpr, UnaryOperator::AddrOf, 6868 MemPtrType, UnOp->getOperatorLoc()); 6869 } 6870 } 6871 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(), 6872 Found, Fn); 6873 if (SubExpr == UnOp->getSubExpr()) 6874 return UnOp->Retain(); 6875 6876 return new (Context) UnaryOperator(SubExpr, UnaryOperator::AddrOf, 6877 Context.getPointerType(SubExpr->getType()), 6878 UnOp->getOperatorLoc()); 6879 } 6880 6881 if (UnresolvedLookupExpr *ULE = dyn_cast<UnresolvedLookupExpr>(E)) { 6882 // FIXME: avoid copy. 6883 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 6884 if (ULE->hasExplicitTemplateArgs()) { 6885 ULE->copyTemplateArgumentsInto(TemplateArgsBuffer); 6886 TemplateArgs = &TemplateArgsBuffer; 6887 } 6888 6889 return DeclRefExpr::Create(Context, 6890 ULE->getQualifier(), 6891 ULE->getQualifierRange(), 6892 Fn, 6893 ULE->getNameLoc(), 6894 Fn->getType(), 6895 TemplateArgs); 6896 } 6897 6898 if (UnresolvedMemberExpr *MemExpr = dyn_cast<UnresolvedMemberExpr>(E)) { 6899 // FIXME: avoid copy. 6900 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 6901 if (MemExpr->hasExplicitTemplateArgs()) { 6902 MemExpr->copyTemplateArgumentsInto(TemplateArgsBuffer); 6903 TemplateArgs = &TemplateArgsBuffer; 6904 } 6905 6906 Expr *Base; 6907 6908 // If we're filling in 6909 if (MemExpr->isImplicitAccess()) { 6910 if (cast<CXXMethodDecl>(Fn)->isStatic()) { 6911 return DeclRefExpr::Create(Context, 6912 MemExpr->getQualifier(), 6913 MemExpr->getQualifierRange(), 6914 Fn, 6915 MemExpr->getMemberLoc(), 6916 Fn->getType(), 6917 TemplateArgs); 6918 } else { 6919 SourceLocation Loc = MemExpr->getMemberLoc(); 6920 if (MemExpr->getQualifier()) 6921 Loc = MemExpr->getQualifierRange().getBegin(); 6922 Base = new (Context) CXXThisExpr(Loc, 6923 MemExpr->getBaseType(), 6924 /*isImplicit=*/true); 6925 } 6926 } else 6927 Base = MemExpr->getBase()->Retain(); 6928 6929 return MemberExpr::Create(Context, Base, 6930 MemExpr->isArrow(), 6931 MemExpr->getQualifier(), 6932 MemExpr->getQualifierRange(), 6933 Fn, 6934 Found, 6935 MemExpr->getMemberLoc(), 6936 TemplateArgs, 6937 Fn->getType()); 6938 } 6939 6940 assert(false && "Invalid reference to overloaded function"); 6941 return E->Retain(); 6942} 6943 6944Sema::OwningExprResult Sema::FixOverloadedFunctionReference(OwningExprResult E, 6945 DeclAccessPair Found, 6946 FunctionDecl *Fn) { 6947 return Owned(FixOverloadedFunctionReference((Expr *)E.get(), Found, Fn)); 6948} 6949 6950} // end namespace clang 6951