SemaOverload.cpp revision d9842d0e6da0e28b6913b464e37d9a4dc5ec73b9
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 "clang/Basic/Diagnostic.h" 16#include "clang/Lex/Preprocessor.h" 17#include "clang/AST/ASTContext.h" 18#include "clang/AST/CXXInheritance.h" 19#include "clang/AST/Expr.h" 20#include "clang/AST/ExprCXX.h" 21#include "clang/AST/TypeOrdering.h" 22#include "clang/Basic/PartialDiagnostic.h" 23#include "llvm/ADT/SmallPtrSet.h" 24#include "llvm/ADT/STLExtras.h" 25#include "llvm/Support/Compiler.h" 26#include <algorithm> 27#include <cstdio> 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_Qualification_Adjustment, 42 ICC_Promotion, 43 ICC_Promotion, 44 ICC_Promotion, 45 ICC_Conversion, 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 }; 56 return Category[(int)Kind]; 57} 58 59/// GetConversionRank - Retrieve the implicit conversion rank 60/// corresponding to the given implicit conversion kind. 61ImplicitConversionRank GetConversionRank(ImplicitConversionKind Kind) { 62 static const ImplicitConversionRank 63 Rank[(int)ICK_Num_Conversion_Kinds] = { 64 ICR_Exact_Match, 65 ICR_Exact_Match, 66 ICR_Exact_Match, 67 ICR_Exact_Match, 68 ICR_Exact_Match, 69 ICR_Promotion, 70 ICR_Promotion, 71 ICR_Promotion, 72 ICR_Conversion, 73 ICR_Conversion, 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 }; 83 return Rank[(int)Kind]; 84} 85 86/// GetImplicitConversionName - Return the name of this kind of 87/// implicit conversion. 88const char* GetImplicitConversionName(ImplicitConversionKind Kind) { 89 static const char* Name[(int)ICK_Num_Conversion_Kinds] = { 90 "No conversion", 91 "Lvalue-to-rvalue", 92 "Array-to-pointer", 93 "Function-to-pointer", 94 "Qualification", 95 "Integral promotion", 96 "Floating point promotion", 97 "Complex promotion", 98 "Integral conversion", 99 "Floating conversion", 100 "Complex conversion", 101 "Floating-integral conversion", 102 "Complex-real conversion", 103 "Pointer conversion", 104 "Pointer-to-member conversion", 105 "Boolean conversion", 106 "Compatible-types conversion", 107 "Derived-to-base conversion" 108 }; 109 return Name[Kind]; 110} 111 112/// StandardConversionSequence - Set the standard conversion 113/// sequence to the identity conversion. 114void StandardConversionSequence::setAsIdentityConversion() { 115 First = ICK_Identity; 116 Second = ICK_Identity; 117 Third = ICK_Identity; 118 Deprecated = false; 119 ReferenceBinding = false; 120 DirectBinding = false; 121 RRefBinding = false; 122 CopyConstructor = 0; 123} 124 125/// getRank - Retrieve the rank of this standard conversion sequence 126/// (C++ 13.3.3.1.1p3). The rank is the largest rank of each of the 127/// implicit conversions. 128ImplicitConversionRank StandardConversionSequence::getRank() const { 129 ImplicitConversionRank Rank = ICR_Exact_Match; 130 if (GetConversionRank(First) > Rank) 131 Rank = GetConversionRank(First); 132 if (GetConversionRank(Second) > Rank) 133 Rank = GetConversionRank(Second); 134 if (GetConversionRank(Third) > Rank) 135 Rank = GetConversionRank(Third); 136 return Rank; 137} 138 139/// isPointerConversionToBool - Determines whether this conversion is 140/// a conversion of a pointer or pointer-to-member to bool. This is 141/// used as part of the ranking of standard conversion sequences 142/// (C++ 13.3.3.2p4). 143bool StandardConversionSequence::isPointerConversionToBool() const { 144 QualType FromType = QualType::getFromOpaquePtr(FromTypePtr); 145 QualType ToType = QualType::getFromOpaquePtr(ToTypePtr); 146 147 // 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 (ToType->isBooleanType() && 152 (FromType->isPointerType() || FromType->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 = QualType::getFromOpaquePtr(FromTypePtr); 167 QualType ToType = QualType::getFromOpaquePtr(ToTypePtr); 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) 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 bool PrintedSomething = false; 186 if (First != ICK_Identity) { 187 fprintf(stderr, "%s", GetImplicitConversionName(First)); 188 PrintedSomething = true; 189 } 190 191 if (Second != ICK_Identity) { 192 if (PrintedSomething) { 193 fprintf(stderr, " -> "); 194 } 195 fprintf(stderr, "%s", GetImplicitConversionName(Second)); 196 197 if (CopyConstructor) { 198 fprintf(stderr, " (by copy constructor)"); 199 } else if (DirectBinding) { 200 fprintf(stderr, " (direct reference binding)"); 201 } else if (ReferenceBinding) { 202 fprintf(stderr, " (reference binding)"); 203 } 204 PrintedSomething = true; 205 } 206 207 if (Third != ICK_Identity) { 208 if (PrintedSomething) { 209 fprintf(stderr, " -> "); 210 } 211 fprintf(stderr, "%s", GetImplicitConversionName(Third)); 212 PrintedSomething = true; 213 } 214 215 if (!PrintedSomething) { 216 fprintf(stderr, "No conversions required"); 217 } 218} 219 220/// DebugPrint - Print this user-defined conversion sequence to standard 221/// error. Useful for debugging overloading issues. 222void UserDefinedConversionSequence::DebugPrint() const { 223 if (Before.First || Before.Second || Before.Third) { 224 Before.DebugPrint(); 225 fprintf(stderr, " -> "); 226 } 227 fprintf(stderr, "'%s'", ConversionFunction->getNameAsString().c_str()); 228 if (After.First || After.Second || After.Third) { 229 fprintf(stderr, " -> "); 230 After.DebugPrint(); 231 } 232} 233 234/// DebugPrint - Print this implicit conversion sequence to standard 235/// error. Useful for debugging overloading issues. 236void ImplicitConversionSequence::DebugPrint() const { 237 switch (ConversionKind) { 238 case StandardConversion: 239 fprintf(stderr, "Standard conversion: "); 240 Standard.DebugPrint(); 241 break; 242 case UserDefinedConversion: 243 fprintf(stderr, "User-defined conversion: "); 244 UserDefined.DebugPrint(); 245 break; 246 case EllipsisConversion: 247 fprintf(stderr, "Ellipsis conversion"); 248 break; 249 case BadConversion: 250 fprintf(stderr, "Bad conversion"); 251 break; 252 } 253 254 fprintf(stderr, "\n"); 255} 256 257// IsOverload - Determine whether the given New declaration is an 258// overload of the Old declaration. This routine returns false if New 259// and Old cannot be overloaded, e.g., if they are functions with the 260// same signature (C++ 1.3.10) or if the Old declaration isn't a 261// function (or overload set). When it does return false and Old is an 262// OverloadedFunctionDecl, MatchedDecl will be set to point to the 263// FunctionDecl that New cannot be overloaded with. 264// 265// Example: Given the following input: 266// 267// void f(int, float); // #1 268// void f(int, int); // #2 269// int f(int, int); // #3 270// 271// When we process #1, there is no previous declaration of "f", 272// so IsOverload will not be used. 273// 274// When we process #2, Old is a FunctionDecl for #1. By comparing the 275// parameter types, we see that #1 and #2 are overloaded (since they 276// have different signatures), so this routine returns false; 277// MatchedDecl is unchanged. 278// 279// When we process #3, Old is an OverloadedFunctionDecl containing #1 280// and #2. We compare the signatures of #3 to #1 (they're overloaded, 281// so we do nothing) and then #3 to #2. Since the signatures of #3 and 282// #2 are identical (return types of functions are not part of the 283// signature), IsOverload returns false and MatchedDecl will be set to 284// point to the FunctionDecl for #2. 285bool 286Sema::IsOverload(FunctionDecl *New, Decl* OldD, 287 OverloadedFunctionDecl::function_iterator& MatchedDecl) { 288 if (OverloadedFunctionDecl* Ovl = dyn_cast<OverloadedFunctionDecl>(OldD)) { 289 // Is this new function an overload of every function in the 290 // overload set? 291 OverloadedFunctionDecl::function_iterator Func = Ovl->function_begin(), 292 FuncEnd = Ovl->function_end(); 293 for (; Func != FuncEnd; ++Func) { 294 if (!IsOverload(New, *Func, MatchedDecl)) { 295 MatchedDecl = Func; 296 return false; 297 } 298 } 299 300 // This function overloads every function in the overload set. 301 return true; 302 } else if (FunctionTemplateDecl *Old = dyn_cast<FunctionTemplateDecl>(OldD)) 303 return IsOverload(New, Old->getTemplatedDecl(), MatchedDecl); 304 else if (FunctionDecl* Old = dyn_cast<FunctionDecl>(OldD)) { 305 FunctionTemplateDecl *OldTemplate = Old->getDescribedFunctionTemplate(); 306 FunctionTemplateDecl *NewTemplate = New->getDescribedFunctionTemplate(); 307 308 // C++ [temp.fct]p2: 309 // A function template can be overloaded with other function templates 310 // and with normal (non-template) functions. 311 if ((OldTemplate == 0) != (NewTemplate == 0)) 312 return true; 313 314 // Is the function New an overload of the function Old? 315 QualType OldQType = Context.getCanonicalType(Old->getType()); 316 QualType NewQType = Context.getCanonicalType(New->getType()); 317 318 // Compare the signatures (C++ 1.3.10) of the two functions to 319 // determine whether they are overloads. If we find any mismatch 320 // in the signature, they are overloads. 321 322 // If either of these functions is a K&R-style function (no 323 // prototype), then we consider them to have matching signatures. 324 if (isa<FunctionNoProtoType>(OldQType.getTypePtr()) || 325 isa<FunctionNoProtoType>(NewQType.getTypePtr())) 326 return false; 327 328 FunctionProtoType* OldType = cast<FunctionProtoType>(OldQType); 329 FunctionProtoType* NewType = cast<FunctionProtoType>(NewQType); 330 331 // The signature of a function includes the types of its 332 // parameters (C++ 1.3.10), which includes the presence or absence 333 // of the ellipsis; see C++ DR 357). 334 if (OldQType != NewQType && 335 (OldType->getNumArgs() != NewType->getNumArgs() || 336 OldType->isVariadic() != NewType->isVariadic() || 337 !std::equal(OldType->arg_type_begin(), OldType->arg_type_end(), 338 NewType->arg_type_begin()))) 339 return true; 340 341 // C++ [temp.over.link]p4: 342 // The signature of a function template consists of its function 343 // signature, its return type and its template parameter list. The names 344 // of the template parameters are significant only for establishing the 345 // relationship between the template parameters and the rest of the 346 // signature. 347 // 348 // We check the return type and template parameter lists for function 349 // templates first; the remaining checks follow. 350 if (NewTemplate && 351 (!TemplateParameterListsAreEqual(NewTemplate->getTemplateParameters(), 352 OldTemplate->getTemplateParameters(), 353 false, false, SourceLocation()) || 354 OldType->getResultType() != NewType->getResultType())) 355 return true; 356 357 // If the function is a class member, its signature includes the 358 // cv-qualifiers (if any) on the function itself. 359 // 360 // As part of this, also check whether one of the member functions 361 // is static, in which case they are not overloads (C++ 362 // 13.1p2). While not part of the definition of the signature, 363 // this check is important to determine whether these functions 364 // can be overloaded. 365 CXXMethodDecl* OldMethod = dyn_cast<CXXMethodDecl>(Old); 366 CXXMethodDecl* NewMethod = dyn_cast<CXXMethodDecl>(New); 367 if (OldMethod && NewMethod && 368 !OldMethod->isStatic() && !NewMethod->isStatic() && 369 OldMethod->getTypeQualifiers() != NewMethod->getTypeQualifiers()) 370 return true; 371 372 // The signatures match; this is not an overload. 373 return false; 374 } else { 375 // (C++ 13p1): 376 // Only function declarations can be overloaded; object and type 377 // declarations cannot be overloaded. 378 return false; 379 } 380} 381 382/// TryImplicitConversion - Attempt to perform an implicit conversion 383/// from the given expression (Expr) to the given type (ToType). This 384/// function returns an implicit conversion sequence that can be used 385/// to perform the initialization. Given 386/// 387/// void f(float f); 388/// void g(int i) { f(i); } 389/// 390/// this routine would produce an implicit conversion sequence to 391/// describe the initialization of f from i, which will be a standard 392/// conversion sequence containing an lvalue-to-rvalue conversion (C++ 393/// 4.1) followed by a floating-integral conversion (C++ 4.9). 394// 395/// Note that this routine only determines how the conversion can be 396/// performed; it does not actually perform the conversion. As such, 397/// it will not produce any diagnostics if no conversion is available, 398/// but will instead return an implicit conversion sequence of kind 399/// "BadConversion". 400/// 401/// If @p SuppressUserConversions, then user-defined conversions are 402/// not permitted. 403/// If @p AllowExplicit, then explicit user-defined conversions are 404/// permitted. 405/// If @p ForceRValue, then overloading is performed as if From was an rvalue, 406/// no matter its actual lvalueness. 407/// If @p UserCast, the implicit conversion is being done for a user-specified 408/// cast. 409ImplicitConversionSequence 410Sema::TryImplicitConversion(Expr* From, QualType ToType, 411 bool SuppressUserConversions, 412 bool AllowExplicit, bool ForceRValue, 413 bool InOverloadResolution, 414 bool UserCast) { 415 ImplicitConversionSequence ICS; 416 OverloadCandidateSet Conversions; 417 OverloadingResult UserDefResult = OR_Success; 418 if (IsStandardConversion(From, ToType, InOverloadResolution, ICS.Standard)) 419 ICS.ConversionKind = ImplicitConversionSequence::StandardConversion; 420 else if (getLangOptions().CPlusPlus && 421 (UserDefResult = IsUserDefinedConversion(From, ToType, 422 ICS.UserDefined, 423 Conversions, 424 !SuppressUserConversions, AllowExplicit, 425 ForceRValue, UserCast)) == OR_Success) { 426 ICS.ConversionKind = ImplicitConversionSequence::UserDefinedConversion; 427 // C++ [over.ics.user]p4: 428 // A conversion of an expression of class type to the same class 429 // type is given Exact Match rank, and a conversion of an 430 // expression of class type to a base class of that type is 431 // given Conversion rank, in spite of the fact that a copy 432 // constructor (i.e., a user-defined conversion function) is 433 // called for those cases. 434 if (CXXConstructorDecl *Constructor 435 = dyn_cast<CXXConstructorDecl>(ICS.UserDefined.ConversionFunction)) { 436 QualType FromCanon 437 = Context.getCanonicalType(From->getType().getUnqualifiedType()); 438 QualType ToCanon = Context.getCanonicalType(ToType).getUnqualifiedType(); 439 if (FromCanon == ToCanon || IsDerivedFrom(FromCanon, ToCanon)) { 440 // Turn this into a "standard" conversion sequence, so that it 441 // gets ranked with standard conversion sequences. 442 ICS.ConversionKind = ImplicitConversionSequence::StandardConversion; 443 ICS.Standard.setAsIdentityConversion(); 444 ICS.Standard.FromTypePtr = From->getType().getAsOpaquePtr(); 445 ICS.Standard.ToTypePtr = ToType.getAsOpaquePtr(); 446 ICS.Standard.CopyConstructor = Constructor; 447 if (ToCanon != FromCanon) 448 ICS.Standard.Second = ICK_Derived_To_Base; 449 } 450 } 451 452 // C++ [over.best.ics]p4: 453 // However, when considering the argument of a user-defined 454 // conversion function that is a candidate by 13.3.1.3 when 455 // invoked for the copying of the temporary in the second step 456 // of a class copy-initialization, or by 13.3.1.4, 13.3.1.5, or 457 // 13.3.1.6 in all cases, only standard conversion sequences and 458 // ellipsis conversion sequences are allowed. 459 if (SuppressUserConversions && 460 ICS.ConversionKind == ImplicitConversionSequence::UserDefinedConversion) 461 ICS.ConversionKind = ImplicitConversionSequence::BadConversion; 462 } else { 463 ICS.ConversionKind = ImplicitConversionSequence::BadConversion; 464 if (UserDefResult == OR_Ambiguous) { 465 for (OverloadCandidateSet::iterator Cand = Conversions.begin(); 466 Cand != Conversions.end(); ++Cand) 467 if (Cand->Viable) 468 ICS.ConversionFunctionSet.push_back(Cand->Function); 469 } 470 } 471 472 return ICS; 473} 474 475/// IsStandardConversion - Determines whether there is a standard 476/// conversion sequence (C++ [conv], C++ [over.ics.scs]) from the 477/// expression From to the type ToType. Standard conversion sequences 478/// only consider non-class types; for conversions that involve class 479/// types, use TryImplicitConversion. If a conversion exists, SCS will 480/// contain the standard conversion sequence required to perform this 481/// conversion and this routine will return true. Otherwise, this 482/// routine will return false and the value of SCS is unspecified. 483bool 484Sema::IsStandardConversion(Expr* From, QualType ToType, 485 bool InOverloadResolution, 486 StandardConversionSequence &SCS) { 487 QualType FromType = From->getType(); 488 489 // Standard conversions (C++ [conv]) 490 SCS.setAsIdentityConversion(); 491 SCS.Deprecated = false; 492 SCS.IncompatibleObjC = false; 493 SCS.FromTypePtr = FromType.getAsOpaquePtr(); 494 SCS.CopyConstructor = 0; 495 496 // There are no standard conversions for class types in C++, so 497 // abort early. When overloading in C, however, we do permit 498 if (FromType->isRecordType() || ToType->isRecordType()) { 499 if (getLangOptions().CPlusPlus) 500 return false; 501 502 // When we're overloading in C, we allow, as standard conversions, 503 } 504 505 // The first conversion can be an lvalue-to-rvalue conversion, 506 // array-to-pointer conversion, or function-to-pointer conversion 507 // (C++ 4p1). 508 509 // Lvalue-to-rvalue conversion (C++ 4.1): 510 // An lvalue (3.10) of a non-function, non-array type T can be 511 // converted to an rvalue. 512 Expr::isLvalueResult argIsLvalue = From->isLvalue(Context); 513 if (argIsLvalue == Expr::LV_Valid && 514 !FromType->isFunctionType() && !FromType->isArrayType() && 515 Context.getCanonicalType(FromType) != Context.OverloadTy) { 516 SCS.First = ICK_Lvalue_To_Rvalue; 517 518 // If T is a non-class type, the type of the rvalue is the 519 // cv-unqualified version of T. Otherwise, the type of the rvalue 520 // is T (C++ 4.1p1). C++ can't get here with class types; in C, we 521 // just strip the qualifiers because they don't matter. 522 523 // FIXME: Doesn't see through to qualifiers behind a typedef! 524 FromType = FromType.getUnqualifiedType(); 525 } else if (FromType->isArrayType()) { 526 // Array-to-pointer conversion (C++ 4.2) 527 SCS.First = ICK_Array_To_Pointer; 528 529 // An lvalue or rvalue of type "array of N T" or "array of unknown 530 // bound of T" can be converted to an rvalue of type "pointer to 531 // T" (C++ 4.2p1). 532 FromType = Context.getArrayDecayedType(FromType); 533 534 if (IsStringLiteralToNonConstPointerConversion(From, ToType)) { 535 // This conversion is deprecated. (C++ D.4). 536 SCS.Deprecated = true; 537 538 // For the purpose of ranking in overload resolution 539 // (13.3.3.1.1), this conversion is considered an 540 // array-to-pointer conversion followed by a qualification 541 // conversion (4.4). (C++ 4.2p2) 542 SCS.Second = ICK_Identity; 543 SCS.Third = ICK_Qualification; 544 SCS.ToTypePtr = ToType.getAsOpaquePtr(); 545 return true; 546 } 547 } else if (FromType->isFunctionType() && argIsLvalue == Expr::LV_Valid) { 548 // Function-to-pointer conversion (C++ 4.3). 549 SCS.First = ICK_Function_To_Pointer; 550 551 // An lvalue of function type T can be converted to an rvalue of 552 // type "pointer to T." The result is a pointer to the 553 // function. (C++ 4.3p1). 554 FromType = Context.getPointerType(FromType); 555 } else if (FunctionDecl *Fn 556 = ResolveAddressOfOverloadedFunction(From, ToType, false)) { 557 // Address of overloaded function (C++ [over.over]). 558 SCS.First = ICK_Function_To_Pointer; 559 560 // We were able to resolve the address of the overloaded function, 561 // so we can convert to the type of that function. 562 FromType = Fn->getType(); 563 if (ToType->isLValueReferenceType()) 564 FromType = Context.getLValueReferenceType(FromType); 565 else if (ToType->isRValueReferenceType()) 566 FromType = Context.getRValueReferenceType(FromType); 567 else if (ToType->isMemberPointerType()) { 568 // Resolve address only succeeds if both sides are member pointers, 569 // but it doesn't have to be the same class. See DR 247. 570 // Note that this means that the type of &Derived::fn can be 571 // Ret (Base::*)(Args) if the fn overload actually found is from the 572 // base class, even if it was brought into the derived class via a 573 // using declaration. The standard isn't clear on this issue at all. 574 CXXMethodDecl *M = cast<CXXMethodDecl>(Fn); 575 FromType = Context.getMemberPointerType(FromType, 576 Context.getTypeDeclType(M->getParent()).getTypePtr()); 577 } else 578 FromType = Context.getPointerType(FromType); 579 } else { 580 // We don't require any conversions for the first step. 581 SCS.First = ICK_Identity; 582 } 583 584 // The second conversion can be an integral promotion, floating 585 // point promotion, integral conversion, floating point conversion, 586 // floating-integral conversion, pointer conversion, 587 // pointer-to-member conversion, or boolean conversion (C++ 4p1). 588 // For overloading in C, this can also be a "compatible-type" 589 // conversion. 590 bool IncompatibleObjC = false; 591 if (Context.hasSameUnqualifiedType(FromType, ToType)) { 592 // The unqualified versions of the types are the same: there's no 593 // conversion to do. 594 SCS.Second = ICK_Identity; 595 } else if (IsIntegralPromotion(From, FromType, ToType)) { 596 // Integral promotion (C++ 4.5). 597 SCS.Second = ICK_Integral_Promotion; 598 FromType = ToType.getUnqualifiedType(); 599 } else if (IsFloatingPointPromotion(FromType, ToType)) { 600 // Floating point promotion (C++ 4.6). 601 SCS.Second = ICK_Floating_Promotion; 602 FromType = ToType.getUnqualifiedType(); 603 } else if (IsComplexPromotion(FromType, ToType)) { 604 // Complex promotion (Clang extension) 605 SCS.Second = ICK_Complex_Promotion; 606 FromType = ToType.getUnqualifiedType(); 607 } else if ((FromType->isIntegralType() || FromType->isEnumeralType()) && 608 (ToType->isIntegralType() && !ToType->isEnumeralType())) { 609 // Integral conversions (C++ 4.7). 610 // FIXME: isIntegralType shouldn't be true for enums in C++. 611 SCS.Second = ICK_Integral_Conversion; 612 FromType = ToType.getUnqualifiedType(); 613 } else if (FromType->isFloatingType() && ToType->isFloatingType()) { 614 // Floating point conversions (C++ 4.8). 615 SCS.Second = ICK_Floating_Conversion; 616 FromType = ToType.getUnqualifiedType(); 617 } else if (FromType->isComplexType() && ToType->isComplexType()) { 618 // Complex conversions (C99 6.3.1.6) 619 SCS.Second = ICK_Complex_Conversion; 620 FromType = ToType.getUnqualifiedType(); 621 } else if ((FromType->isFloatingType() && 622 ToType->isIntegralType() && (!ToType->isBooleanType() && 623 !ToType->isEnumeralType())) || 624 ((FromType->isIntegralType() || FromType->isEnumeralType()) && 625 ToType->isFloatingType())) { 626 // Floating-integral conversions (C++ 4.9). 627 // FIXME: isIntegralType shouldn't be true for enums in C++. 628 SCS.Second = ICK_Floating_Integral; 629 FromType = ToType.getUnqualifiedType(); 630 } else if ((FromType->isComplexType() && ToType->isArithmeticType()) || 631 (ToType->isComplexType() && FromType->isArithmeticType())) { 632 // Complex-real conversions (C99 6.3.1.7) 633 SCS.Second = ICK_Complex_Real; 634 FromType = ToType.getUnqualifiedType(); 635 } else if (IsPointerConversion(From, FromType, ToType, InOverloadResolution, 636 FromType, IncompatibleObjC)) { 637 // Pointer conversions (C++ 4.10). 638 SCS.Second = ICK_Pointer_Conversion; 639 SCS.IncompatibleObjC = IncompatibleObjC; 640 } else if (IsMemberPointerConversion(From, FromType, ToType, 641 InOverloadResolution, FromType)) { 642 // Pointer to member conversions (4.11). 643 SCS.Second = ICK_Pointer_Member; 644 } else if (ToType->isBooleanType() && 645 (FromType->isArithmeticType() || 646 FromType->isEnumeralType() || 647 FromType->isPointerType() || 648 FromType->isBlockPointerType() || 649 FromType->isMemberPointerType() || 650 FromType->isNullPtrType())) { 651 // Boolean conversions (C++ 4.12). 652 SCS.Second = ICK_Boolean_Conversion; 653 FromType = Context.BoolTy; 654 } else if (!getLangOptions().CPlusPlus && 655 Context.typesAreCompatible(ToType, FromType)) { 656 // Compatible conversions (Clang extension for C function overloading) 657 SCS.Second = ICK_Compatible_Conversion; 658 } else { 659 // No second conversion required. 660 SCS.Second = ICK_Identity; 661 } 662 663 QualType CanonFrom; 664 QualType CanonTo; 665 // The third conversion can be a qualification conversion (C++ 4p1). 666 if (IsQualificationConversion(FromType, ToType)) { 667 SCS.Third = ICK_Qualification; 668 FromType = ToType; 669 CanonFrom = Context.getCanonicalType(FromType); 670 CanonTo = Context.getCanonicalType(ToType); 671 } else { 672 // No conversion required 673 SCS.Third = ICK_Identity; 674 675 // C++ [over.best.ics]p6: 676 // [...] Any difference in top-level cv-qualification is 677 // subsumed by the initialization itself and does not constitute 678 // a conversion. [...] 679 CanonFrom = Context.getCanonicalType(FromType); 680 CanonTo = Context.getCanonicalType(ToType); 681 if (CanonFrom.getUnqualifiedType() == CanonTo.getUnqualifiedType() && 682 CanonFrom.getCVRQualifiers() != CanonTo.getCVRQualifiers()) { 683 FromType = ToType; 684 CanonFrom = CanonTo; 685 } 686 } 687 688 // If we have not converted the argument type to the parameter type, 689 // this is a bad conversion sequence. 690 if (CanonFrom != CanonTo) 691 return false; 692 693 SCS.ToTypePtr = FromType.getAsOpaquePtr(); 694 return true; 695} 696 697/// IsIntegralPromotion - Determines whether the conversion from the 698/// expression From (whose potentially-adjusted type is FromType) to 699/// ToType is an integral promotion (C++ 4.5). If so, returns true and 700/// sets PromotedType to the promoted type. 701bool Sema::IsIntegralPromotion(Expr *From, QualType FromType, QualType ToType) { 702 const BuiltinType *To = ToType->getAs<BuiltinType>(); 703 // All integers are built-in. 704 if (!To) { 705 return false; 706 } 707 708 // An rvalue of type char, signed char, unsigned char, short int, or 709 // unsigned short int can be converted to an rvalue of type int if 710 // int can represent all the values of the source type; otherwise, 711 // the source rvalue can be converted to an rvalue of type unsigned 712 // int (C++ 4.5p1). 713 if (FromType->isPromotableIntegerType() && !FromType->isBooleanType()) { 714 if (// We can promote any signed, promotable integer type to an int 715 (FromType->isSignedIntegerType() || 716 // We can promote any unsigned integer type whose size is 717 // less than int to an int. 718 (!FromType->isSignedIntegerType() && 719 Context.getTypeSize(FromType) < Context.getTypeSize(ToType)))) { 720 return To->getKind() == BuiltinType::Int; 721 } 722 723 return To->getKind() == BuiltinType::UInt; 724 } 725 726 // An rvalue of type wchar_t (3.9.1) or an enumeration type (7.2) 727 // can be converted to an rvalue of the first of the following types 728 // that can represent all the values of its underlying type: int, 729 // unsigned int, long, or unsigned long (C++ 4.5p2). 730 if ((FromType->isEnumeralType() || FromType->isWideCharType()) 731 && ToType->isIntegerType()) { 732 // Determine whether the type we're converting from is signed or 733 // unsigned. 734 bool FromIsSigned; 735 uint64_t FromSize = Context.getTypeSize(FromType); 736 if (const EnumType *FromEnumType = FromType->getAs<EnumType>()) { 737 QualType UnderlyingType = FromEnumType->getDecl()->getIntegerType(); 738 FromIsSigned = UnderlyingType->isSignedIntegerType(); 739 } else { 740 // FIXME: Is wchar_t signed or unsigned? We assume it's signed for now. 741 FromIsSigned = true; 742 } 743 744 // The types we'll try to promote to, in the appropriate 745 // order. Try each of these types. 746 QualType PromoteTypes[6] = { 747 Context.IntTy, Context.UnsignedIntTy, 748 Context.LongTy, Context.UnsignedLongTy , 749 Context.LongLongTy, Context.UnsignedLongLongTy 750 }; 751 for (int Idx = 0; Idx < 6; ++Idx) { 752 uint64_t ToSize = Context.getTypeSize(PromoteTypes[Idx]); 753 if (FromSize < ToSize || 754 (FromSize == ToSize && 755 FromIsSigned == PromoteTypes[Idx]->isSignedIntegerType())) { 756 // We found the type that we can promote to. If this is the 757 // type we wanted, we have a promotion. Otherwise, no 758 // promotion. 759 return Context.getCanonicalType(ToType).getUnqualifiedType() 760 == Context.getCanonicalType(PromoteTypes[Idx]).getUnqualifiedType(); 761 } 762 } 763 } 764 765 // An rvalue for an integral bit-field (9.6) can be converted to an 766 // rvalue of type int if int can represent all the values of the 767 // bit-field; otherwise, it can be converted to unsigned int if 768 // unsigned int can represent all the values of the bit-field. If 769 // the bit-field is larger yet, no integral promotion applies to 770 // it. If the bit-field has an enumerated type, it is treated as any 771 // other value of that type for promotion purposes (C++ 4.5p3). 772 // FIXME: We should delay checking of bit-fields until we actually perform the 773 // conversion. 774 using llvm::APSInt; 775 if (From) 776 if (FieldDecl *MemberDecl = From->getBitField()) { 777 APSInt BitWidth; 778 if (FromType->isIntegralType() && !FromType->isEnumeralType() && 779 MemberDecl->getBitWidth()->isIntegerConstantExpr(BitWidth, Context)) { 780 APSInt ToSize(BitWidth.getBitWidth(), BitWidth.isUnsigned()); 781 ToSize = Context.getTypeSize(ToType); 782 783 // Are we promoting to an int from a bitfield that fits in an int? 784 if (BitWidth < ToSize || 785 (FromType->isSignedIntegerType() && BitWidth <= ToSize)) { 786 return To->getKind() == BuiltinType::Int; 787 } 788 789 // Are we promoting to an unsigned int from an unsigned bitfield 790 // that fits into an unsigned int? 791 if (FromType->isUnsignedIntegerType() && BitWidth <= ToSize) { 792 return To->getKind() == BuiltinType::UInt; 793 } 794 795 return false; 796 } 797 } 798 799 // An rvalue of type bool can be converted to an rvalue of type int, 800 // with false becoming zero and true becoming one (C++ 4.5p4). 801 if (FromType->isBooleanType() && To->getKind() == BuiltinType::Int) { 802 return true; 803 } 804 805 return false; 806} 807 808/// IsFloatingPointPromotion - Determines whether the conversion from 809/// FromType to ToType is a floating point promotion (C++ 4.6). If so, 810/// returns true and sets PromotedType to the promoted type. 811bool Sema::IsFloatingPointPromotion(QualType FromType, QualType ToType) { 812 /// An rvalue of type float can be converted to an rvalue of type 813 /// double. (C++ 4.6p1). 814 if (const BuiltinType *FromBuiltin = FromType->getAs<BuiltinType>()) 815 if (const BuiltinType *ToBuiltin = ToType->getAs<BuiltinType>()) { 816 if (FromBuiltin->getKind() == BuiltinType::Float && 817 ToBuiltin->getKind() == BuiltinType::Double) 818 return true; 819 820 // C99 6.3.1.5p1: 821 // When a float is promoted to double or long double, or a 822 // double is promoted to long double [...]. 823 if (!getLangOptions().CPlusPlus && 824 (FromBuiltin->getKind() == BuiltinType::Float || 825 FromBuiltin->getKind() == BuiltinType::Double) && 826 (ToBuiltin->getKind() == BuiltinType::LongDouble)) 827 return true; 828 } 829 830 return false; 831} 832 833/// \brief Determine if a conversion is a complex promotion. 834/// 835/// A complex promotion is defined as a complex -> complex conversion 836/// where the conversion between the underlying real types is a 837/// floating-point or integral promotion. 838bool Sema::IsComplexPromotion(QualType FromType, QualType ToType) { 839 const ComplexType *FromComplex = FromType->getAs<ComplexType>(); 840 if (!FromComplex) 841 return false; 842 843 const ComplexType *ToComplex = ToType->getAs<ComplexType>(); 844 if (!ToComplex) 845 return false; 846 847 return IsFloatingPointPromotion(FromComplex->getElementType(), 848 ToComplex->getElementType()) || 849 IsIntegralPromotion(0, FromComplex->getElementType(), 850 ToComplex->getElementType()); 851} 852 853/// BuildSimilarlyQualifiedPointerType - In a pointer conversion from 854/// the pointer type FromPtr to a pointer to type ToPointee, with the 855/// same type qualifiers as FromPtr has on its pointee type. ToType, 856/// if non-empty, will be a pointer to ToType that may or may not have 857/// the right set of qualifiers on its pointee. 858static QualType 859BuildSimilarlyQualifiedPointerType(const PointerType *FromPtr, 860 QualType ToPointee, QualType ToType, 861 ASTContext &Context) { 862 QualType CanonFromPointee = Context.getCanonicalType(FromPtr->getPointeeType()); 863 QualType CanonToPointee = Context.getCanonicalType(ToPointee); 864 Qualifiers Quals = CanonFromPointee.getQualifiers(); 865 866 // Exact qualifier match -> return the pointer type we're converting to. 867 if (CanonToPointee.getQualifiers() == Quals) { 868 // ToType is exactly what we need. Return it. 869 if (!ToType.isNull()) 870 return ToType; 871 872 // Build a pointer to ToPointee. It has the right qualifiers 873 // already. 874 return Context.getPointerType(ToPointee); 875 } 876 877 // Just build a canonical type that has the right qualifiers. 878 return Context.getPointerType( 879 Context.getQualifiedType(CanonToPointee.getUnqualifiedType(), Quals)); 880} 881 882static bool isNullPointerConstantForConversion(Expr *Expr, 883 bool InOverloadResolution, 884 ASTContext &Context) { 885 // Handle value-dependent integral null pointer constants correctly. 886 // http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#903 887 if (Expr->isValueDependent() && !Expr->isTypeDependent() && 888 Expr->getType()->isIntegralType()) 889 return !InOverloadResolution; 890 891 return Expr->isNullPointerConstant(Context, 892 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull 893 : Expr::NPC_ValueDependentIsNull); 894} 895 896/// IsPointerConversion - Determines whether the conversion of the 897/// expression From, which has the (possibly adjusted) type FromType, 898/// can be converted to the type ToType via a pointer conversion (C++ 899/// 4.10). If so, returns true and places the converted type (that 900/// might differ from ToType in its cv-qualifiers at some level) into 901/// ConvertedType. 902/// 903/// This routine also supports conversions to and from block pointers 904/// and conversions with Objective-C's 'id', 'id<protocols...>', and 905/// pointers to interfaces. FIXME: Once we've determined the 906/// appropriate overloading rules for Objective-C, we may want to 907/// split the Objective-C checks into a different routine; however, 908/// GCC seems to consider all of these conversions to be pointer 909/// conversions, so for now they live here. IncompatibleObjC will be 910/// set if the conversion is an allowed Objective-C conversion that 911/// should result in a warning. 912bool Sema::IsPointerConversion(Expr *From, QualType FromType, QualType ToType, 913 bool InOverloadResolution, 914 QualType& ConvertedType, 915 bool &IncompatibleObjC) { 916 IncompatibleObjC = false; 917 if (isObjCPointerConversion(FromType, ToType, ConvertedType, IncompatibleObjC)) 918 return true; 919 920 // Conversion from a null pointer constant to any Objective-C pointer type. 921 if (ToType->isObjCObjectPointerType() && 922 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 923 ConvertedType = ToType; 924 return true; 925 } 926 927 // Blocks: Block pointers can be converted to void*. 928 if (FromType->isBlockPointerType() && ToType->isPointerType() && 929 ToType->getAs<PointerType>()->getPointeeType()->isVoidType()) { 930 ConvertedType = ToType; 931 return true; 932 } 933 // Blocks: A null pointer constant can be converted to a block 934 // pointer type. 935 if (ToType->isBlockPointerType() && 936 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 937 ConvertedType = ToType; 938 return true; 939 } 940 941 // If the left-hand-side is nullptr_t, the right side can be a null 942 // pointer constant. 943 if (ToType->isNullPtrType() && 944 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 945 ConvertedType = ToType; 946 return true; 947 } 948 949 const PointerType* ToTypePtr = ToType->getAs<PointerType>(); 950 if (!ToTypePtr) 951 return false; 952 953 // A null pointer constant can be converted to a pointer type (C++ 4.10p1). 954 if (isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 955 ConvertedType = ToType; 956 return true; 957 } 958 959 // Beyond this point, both types need to be pointers. 960 const PointerType *FromTypePtr = FromType->getAs<PointerType>(); 961 if (!FromTypePtr) 962 return false; 963 964 QualType FromPointeeType = FromTypePtr->getPointeeType(); 965 QualType ToPointeeType = ToTypePtr->getPointeeType(); 966 967 // An rvalue of type "pointer to cv T," where T is an object type, 968 // can be converted to an rvalue of type "pointer to cv void" (C++ 969 // 4.10p2). 970 if (FromPointeeType->isObjectType() && ToPointeeType->isVoidType()) { 971 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 972 ToPointeeType, 973 ToType, Context); 974 return true; 975 } 976 977 // When we're overloading in C, we allow a special kind of pointer 978 // conversion for compatible-but-not-identical pointee types. 979 if (!getLangOptions().CPlusPlus && 980 Context.typesAreCompatible(FromPointeeType, ToPointeeType)) { 981 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 982 ToPointeeType, 983 ToType, Context); 984 return true; 985 } 986 987 // C++ [conv.ptr]p3: 988 // 989 // An rvalue of type "pointer to cv D," where D is a class type, 990 // can be converted to an rvalue of type "pointer to cv B," where 991 // B is a base class (clause 10) of D. If B is an inaccessible 992 // (clause 11) or ambiguous (10.2) base class of D, a program that 993 // necessitates this conversion is ill-formed. The result of the 994 // conversion is a pointer to the base class sub-object of the 995 // derived class object. The null pointer value is converted to 996 // the null pointer value of the destination type. 997 // 998 // Note that we do not check for ambiguity or inaccessibility 999 // here. That is handled by CheckPointerConversion. 1000 if (getLangOptions().CPlusPlus && 1001 FromPointeeType->isRecordType() && ToPointeeType->isRecordType() && 1002 IsDerivedFrom(FromPointeeType, ToPointeeType)) { 1003 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1004 ToPointeeType, 1005 ToType, Context); 1006 return true; 1007 } 1008 1009 return false; 1010} 1011 1012/// isObjCPointerConversion - Determines whether this is an 1013/// Objective-C pointer conversion. Subroutine of IsPointerConversion, 1014/// with the same arguments and return values. 1015bool Sema::isObjCPointerConversion(QualType FromType, QualType ToType, 1016 QualType& ConvertedType, 1017 bool &IncompatibleObjC) { 1018 if (!getLangOptions().ObjC1) 1019 return false; 1020 1021 // First, we handle all conversions on ObjC object pointer types. 1022 const ObjCObjectPointerType* ToObjCPtr = ToType->getAs<ObjCObjectPointerType>(); 1023 const ObjCObjectPointerType *FromObjCPtr = 1024 FromType->getAs<ObjCObjectPointerType>(); 1025 1026 if (ToObjCPtr && FromObjCPtr) { 1027 // Objective C++: We're able to convert between "id" or "Class" and a 1028 // pointer to any interface (in both directions). 1029 if (ToObjCPtr->isObjCBuiltinType() && FromObjCPtr->isObjCBuiltinType()) { 1030 ConvertedType = ToType; 1031 return true; 1032 } 1033 // Conversions with Objective-C's id<...>. 1034 if ((FromObjCPtr->isObjCQualifiedIdType() || 1035 ToObjCPtr->isObjCQualifiedIdType()) && 1036 Context.ObjCQualifiedIdTypesAreCompatible(ToType, FromType, 1037 /*compare=*/false)) { 1038 ConvertedType = ToType; 1039 return true; 1040 } 1041 // Objective C++: We're able to convert from a pointer to an 1042 // interface to a pointer to a different interface. 1043 if (Context.canAssignObjCInterfaces(ToObjCPtr, FromObjCPtr)) { 1044 ConvertedType = ToType; 1045 return true; 1046 } 1047 1048 if (Context.canAssignObjCInterfaces(FromObjCPtr, ToObjCPtr)) { 1049 // Okay: this is some kind of implicit downcast of Objective-C 1050 // interfaces, which is permitted. However, we're going to 1051 // complain about it. 1052 IncompatibleObjC = true; 1053 ConvertedType = FromType; 1054 return true; 1055 } 1056 } 1057 // Beyond this point, both types need to be C pointers or block pointers. 1058 QualType ToPointeeType; 1059 if (const PointerType *ToCPtr = ToType->getAs<PointerType>()) 1060 ToPointeeType = ToCPtr->getPointeeType(); 1061 else if (const BlockPointerType *ToBlockPtr = ToType->getAs<BlockPointerType>()) 1062 ToPointeeType = ToBlockPtr->getPointeeType(); 1063 else 1064 return false; 1065 1066 QualType FromPointeeType; 1067 if (const PointerType *FromCPtr = FromType->getAs<PointerType>()) 1068 FromPointeeType = FromCPtr->getPointeeType(); 1069 else if (const BlockPointerType *FromBlockPtr = FromType->getAs<BlockPointerType>()) 1070 FromPointeeType = FromBlockPtr->getPointeeType(); 1071 else 1072 return false; 1073 1074 // If we have pointers to pointers, recursively check whether this 1075 // is an Objective-C conversion. 1076 if (FromPointeeType->isPointerType() && ToPointeeType->isPointerType() && 1077 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, 1078 IncompatibleObjC)) { 1079 // We always complain about this conversion. 1080 IncompatibleObjC = true; 1081 ConvertedType = ToType; 1082 return true; 1083 } 1084 // If we have pointers to functions or blocks, check whether the only 1085 // differences in the argument and result types are in Objective-C 1086 // pointer conversions. If so, we permit the conversion (but 1087 // complain about it). 1088 const FunctionProtoType *FromFunctionType 1089 = FromPointeeType->getAs<FunctionProtoType>(); 1090 const FunctionProtoType *ToFunctionType 1091 = ToPointeeType->getAs<FunctionProtoType>(); 1092 if (FromFunctionType && ToFunctionType) { 1093 // If the function types are exactly the same, this isn't an 1094 // Objective-C pointer conversion. 1095 if (Context.getCanonicalType(FromPointeeType) 1096 == Context.getCanonicalType(ToPointeeType)) 1097 return false; 1098 1099 // Perform the quick checks that will tell us whether these 1100 // function types are obviously different. 1101 if (FromFunctionType->getNumArgs() != ToFunctionType->getNumArgs() || 1102 FromFunctionType->isVariadic() != ToFunctionType->isVariadic() || 1103 FromFunctionType->getTypeQuals() != ToFunctionType->getTypeQuals()) 1104 return false; 1105 1106 bool HasObjCConversion = false; 1107 if (Context.getCanonicalType(FromFunctionType->getResultType()) 1108 == Context.getCanonicalType(ToFunctionType->getResultType())) { 1109 // Okay, the types match exactly. Nothing to do. 1110 } else if (isObjCPointerConversion(FromFunctionType->getResultType(), 1111 ToFunctionType->getResultType(), 1112 ConvertedType, IncompatibleObjC)) { 1113 // Okay, we have an Objective-C pointer conversion. 1114 HasObjCConversion = true; 1115 } else { 1116 // Function types are too different. Abort. 1117 return false; 1118 } 1119 1120 // Check argument types. 1121 for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumArgs(); 1122 ArgIdx != NumArgs; ++ArgIdx) { 1123 QualType FromArgType = FromFunctionType->getArgType(ArgIdx); 1124 QualType ToArgType = ToFunctionType->getArgType(ArgIdx); 1125 if (Context.getCanonicalType(FromArgType) 1126 == Context.getCanonicalType(ToArgType)) { 1127 // Okay, the types match exactly. Nothing to do. 1128 } else if (isObjCPointerConversion(FromArgType, ToArgType, 1129 ConvertedType, IncompatibleObjC)) { 1130 // Okay, we have an Objective-C pointer conversion. 1131 HasObjCConversion = true; 1132 } else { 1133 // Argument types are too different. Abort. 1134 return false; 1135 } 1136 } 1137 1138 if (HasObjCConversion) { 1139 // We had an Objective-C conversion. Allow this pointer 1140 // conversion, but complain about it. 1141 ConvertedType = ToType; 1142 IncompatibleObjC = true; 1143 return true; 1144 } 1145 } 1146 1147 return false; 1148} 1149 1150/// CheckPointerConversion - Check the pointer conversion from the 1151/// expression From to the type ToType. This routine checks for 1152/// ambiguous or inaccessible derived-to-base pointer 1153/// conversions for which IsPointerConversion has already returned 1154/// true. It returns true and produces a diagnostic if there was an 1155/// error, or returns false otherwise. 1156bool Sema::CheckPointerConversion(Expr *From, QualType ToType, 1157 CastExpr::CastKind &Kind) { 1158 QualType FromType = From->getType(); 1159 1160 if (const PointerType *FromPtrType = FromType->getAs<PointerType>()) 1161 if (const PointerType *ToPtrType = ToType->getAs<PointerType>()) { 1162 QualType FromPointeeType = FromPtrType->getPointeeType(), 1163 ToPointeeType = ToPtrType->getPointeeType(); 1164 1165 if (FromPointeeType->isRecordType() && 1166 ToPointeeType->isRecordType()) { 1167 // We must have a derived-to-base conversion. Check an 1168 // ambiguous or inaccessible conversion. 1169 if (CheckDerivedToBaseConversion(FromPointeeType, ToPointeeType, 1170 From->getExprLoc(), 1171 From->getSourceRange())) 1172 return true; 1173 1174 // The conversion was successful. 1175 Kind = CastExpr::CK_DerivedToBase; 1176 } 1177 } 1178 if (const ObjCObjectPointerType *FromPtrType = 1179 FromType->getAs<ObjCObjectPointerType>()) 1180 if (const ObjCObjectPointerType *ToPtrType = 1181 ToType->getAs<ObjCObjectPointerType>()) { 1182 // Objective-C++ conversions are always okay. 1183 // FIXME: We should have a different class of conversions for the 1184 // Objective-C++ implicit conversions. 1185 if (FromPtrType->isObjCBuiltinType() || ToPtrType->isObjCBuiltinType()) 1186 return false; 1187 1188 } 1189 return false; 1190} 1191 1192/// IsMemberPointerConversion - Determines whether the conversion of the 1193/// expression From, which has the (possibly adjusted) type FromType, can be 1194/// converted to the type ToType via a member pointer conversion (C++ 4.11). 1195/// If so, returns true and places the converted type (that might differ from 1196/// ToType in its cv-qualifiers at some level) into ConvertedType. 1197bool Sema::IsMemberPointerConversion(Expr *From, QualType FromType, 1198 QualType ToType, 1199 bool InOverloadResolution, 1200 QualType &ConvertedType) { 1201 const MemberPointerType *ToTypePtr = ToType->getAs<MemberPointerType>(); 1202 if (!ToTypePtr) 1203 return false; 1204 1205 // A null pointer constant can be converted to a member pointer (C++ 4.11p1) 1206 if (From->isNullPointerConstant(Context, 1207 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull 1208 : Expr::NPC_ValueDependentIsNull)) { 1209 ConvertedType = ToType; 1210 return true; 1211 } 1212 1213 // Otherwise, both types have to be member pointers. 1214 const MemberPointerType *FromTypePtr = FromType->getAs<MemberPointerType>(); 1215 if (!FromTypePtr) 1216 return false; 1217 1218 // A pointer to member of B can be converted to a pointer to member of D, 1219 // where D is derived from B (C++ 4.11p2). 1220 QualType FromClass(FromTypePtr->getClass(), 0); 1221 QualType ToClass(ToTypePtr->getClass(), 0); 1222 // FIXME: What happens when these are dependent? Is this function even called? 1223 1224 if (IsDerivedFrom(ToClass, FromClass)) { 1225 ConvertedType = Context.getMemberPointerType(FromTypePtr->getPointeeType(), 1226 ToClass.getTypePtr()); 1227 return true; 1228 } 1229 1230 return false; 1231} 1232 1233/// CheckMemberPointerConversion - Check the member pointer conversion from the 1234/// expression From to the type ToType. This routine checks for ambiguous or 1235/// virtual (FIXME: or inaccessible) base-to-derived member pointer conversions 1236/// for which IsMemberPointerConversion has already returned true. It returns 1237/// true and produces a diagnostic if there was an error, or returns false 1238/// otherwise. 1239bool Sema::CheckMemberPointerConversion(Expr *From, QualType ToType, 1240 CastExpr::CastKind &Kind) { 1241 QualType FromType = From->getType(); 1242 const MemberPointerType *FromPtrType = FromType->getAs<MemberPointerType>(); 1243 if (!FromPtrType) { 1244 // This must be a null pointer to member pointer conversion 1245 assert(From->isNullPointerConstant(Context, 1246 Expr::NPC_ValueDependentIsNull) && 1247 "Expr must be null pointer constant!"); 1248 Kind = CastExpr::CK_NullToMemberPointer; 1249 return false; 1250 } 1251 1252 const MemberPointerType *ToPtrType = ToType->getAs<MemberPointerType>(); 1253 assert(ToPtrType && "No member pointer cast has a target type " 1254 "that is not a member pointer."); 1255 1256 QualType FromClass = QualType(FromPtrType->getClass(), 0); 1257 QualType ToClass = QualType(ToPtrType->getClass(), 0); 1258 1259 // FIXME: What about dependent types? 1260 assert(FromClass->isRecordType() && "Pointer into non-class."); 1261 assert(ToClass->isRecordType() && "Pointer into non-class."); 1262 1263 CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/false, 1264 /*DetectVirtual=*/true); 1265 bool DerivationOkay = IsDerivedFrom(ToClass, FromClass, Paths); 1266 assert(DerivationOkay && 1267 "Should not have been called if derivation isn't OK."); 1268 (void)DerivationOkay; 1269 1270 if (Paths.isAmbiguous(Context.getCanonicalType(FromClass). 1271 getUnqualifiedType())) { 1272 // Derivation is ambiguous. Redo the check to find the exact paths. 1273 Paths.clear(); 1274 Paths.setRecordingPaths(true); 1275 bool StillOkay = IsDerivedFrom(ToClass, FromClass, Paths); 1276 assert(StillOkay && "Derivation changed due to quantum fluctuation."); 1277 (void)StillOkay; 1278 1279 std::string PathDisplayStr = getAmbiguousPathsDisplayString(Paths); 1280 Diag(From->getExprLoc(), diag::err_ambiguous_memptr_conv) 1281 << 0 << FromClass << ToClass << PathDisplayStr << From->getSourceRange(); 1282 return true; 1283 } 1284 1285 if (const RecordType *VBase = Paths.getDetectedVirtual()) { 1286 Diag(From->getExprLoc(), diag::err_memptr_conv_via_virtual) 1287 << FromClass << ToClass << QualType(VBase, 0) 1288 << From->getSourceRange(); 1289 return true; 1290 } 1291 1292 // Must be a base to derived member conversion. 1293 Kind = CastExpr::CK_BaseToDerivedMemberPointer; 1294 return false; 1295} 1296 1297/// IsQualificationConversion - Determines whether the conversion from 1298/// an rvalue of type FromType to ToType is a qualification conversion 1299/// (C++ 4.4). 1300bool 1301Sema::IsQualificationConversion(QualType FromType, QualType ToType) { 1302 FromType = Context.getCanonicalType(FromType); 1303 ToType = Context.getCanonicalType(ToType); 1304 1305 // If FromType and ToType are the same type, this is not a 1306 // qualification conversion. 1307 if (FromType == ToType) 1308 return false; 1309 1310 // (C++ 4.4p4): 1311 // A conversion can add cv-qualifiers at levels other than the first 1312 // in multi-level pointers, subject to the following rules: [...] 1313 bool PreviousToQualsIncludeConst = true; 1314 bool UnwrappedAnyPointer = false; 1315 while (UnwrapSimilarPointerTypes(FromType, ToType)) { 1316 // Within each iteration of the loop, we check the qualifiers to 1317 // determine if this still looks like a qualification 1318 // conversion. Then, if all is well, we unwrap one more level of 1319 // pointers or pointers-to-members and do it all again 1320 // until there are no more pointers or pointers-to-members left to 1321 // unwrap. 1322 UnwrappedAnyPointer = true; 1323 1324 // -- for every j > 0, if const is in cv 1,j then const is in cv 1325 // 2,j, and similarly for volatile. 1326 if (!ToType.isAtLeastAsQualifiedAs(FromType)) 1327 return false; 1328 1329 // -- if the cv 1,j and cv 2,j are different, then const is in 1330 // every cv for 0 < k < j. 1331 if (FromType.getCVRQualifiers() != ToType.getCVRQualifiers() 1332 && !PreviousToQualsIncludeConst) 1333 return false; 1334 1335 // Keep track of whether all prior cv-qualifiers in the "to" type 1336 // include const. 1337 PreviousToQualsIncludeConst 1338 = PreviousToQualsIncludeConst && ToType.isConstQualified(); 1339 } 1340 1341 // We are left with FromType and ToType being the pointee types 1342 // after unwrapping the original FromType and ToType the same number 1343 // of types. If we unwrapped any pointers, and if FromType and 1344 // ToType have the same unqualified type (since we checked 1345 // qualifiers above), then this is a qualification conversion. 1346 return UnwrappedAnyPointer && 1347 FromType.getUnqualifiedType() == ToType.getUnqualifiedType(); 1348} 1349 1350/// \brief Given a function template or function, extract the function template 1351/// declaration (if any) and the underlying function declaration. 1352template<typename T> 1353static void GetFunctionAndTemplate(AnyFunctionDecl Orig, T *&Function, 1354 FunctionTemplateDecl *&FunctionTemplate) { 1355 FunctionTemplate = dyn_cast<FunctionTemplateDecl>(Orig); 1356 if (FunctionTemplate) 1357 Function = cast<T>(FunctionTemplate->getTemplatedDecl()); 1358 else 1359 Function = cast<T>(Orig); 1360} 1361 1362/// Determines whether there is a user-defined conversion sequence 1363/// (C++ [over.ics.user]) that converts expression From to the type 1364/// ToType. If such a conversion exists, User will contain the 1365/// user-defined conversion sequence that performs such a conversion 1366/// and this routine will return true. Otherwise, this routine returns 1367/// false and User is unspecified. 1368/// 1369/// \param AllowConversionFunctions true if the conversion should 1370/// consider conversion functions at all. If false, only constructors 1371/// will be considered. 1372/// 1373/// \param AllowExplicit true if the conversion should consider C++0x 1374/// "explicit" conversion functions as well as non-explicit conversion 1375/// functions (C++0x [class.conv.fct]p2). 1376/// 1377/// \param ForceRValue true if the expression should be treated as an rvalue 1378/// for overload resolution. 1379/// \param UserCast true if looking for user defined conversion for a static 1380/// cast. 1381Sema::OverloadingResult Sema::IsUserDefinedConversion( 1382 Expr *From, QualType ToType, 1383 UserDefinedConversionSequence& User, 1384 OverloadCandidateSet& CandidateSet, 1385 bool AllowConversionFunctions, 1386 bool AllowExplicit, bool ForceRValue, 1387 bool UserCast) { 1388 if (const RecordType *ToRecordType = ToType->getAs<RecordType>()) { 1389 if (CXXRecordDecl *ToRecordDecl 1390 = dyn_cast<CXXRecordDecl>(ToRecordType->getDecl())) { 1391 // C++ [over.match.ctor]p1: 1392 // When objects of class type are direct-initialized (8.5), or 1393 // copy-initialized from an expression of the same or a 1394 // derived class type (8.5), overload resolution selects the 1395 // constructor. [...] For copy-initialization, the candidate 1396 // functions are all the converting constructors (12.3.1) of 1397 // that class. The argument list is the expression-list within 1398 // the parentheses of the initializer. 1399 DeclarationName ConstructorName 1400 = Context.DeclarationNames.getCXXConstructorName( 1401 Context.getCanonicalType(ToType).getUnqualifiedType()); 1402 DeclContext::lookup_iterator Con, ConEnd; 1403 for (llvm::tie(Con, ConEnd) 1404 = ToRecordDecl->lookup(ConstructorName); 1405 Con != ConEnd; ++Con) { 1406 // Find the constructor (which may be a template). 1407 CXXConstructorDecl *Constructor = 0; 1408 FunctionTemplateDecl *ConstructorTmpl 1409 = dyn_cast<FunctionTemplateDecl>(*Con); 1410 if (ConstructorTmpl) 1411 Constructor 1412 = cast<CXXConstructorDecl>(ConstructorTmpl->getTemplatedDecl()); 1413 else 1414 Constructor = cast<CXXConstructorDecl>(*Con); 1415 1416 if (!Constructor->isInvalidDecl() && 1417 Constructor->isConvertingConstructor(AllowExplicit)) { 1418 if (ConstructorTmpl) 1419 AddTemplateOverloadCandidate(ConstructorTmpl, false, 0, 0, &From, 1420 1, CandidateSet, 1421 /*SuppressUserConversions=*/!UserCast, 1422 ForceRValue); 1423 else 1424 // Allow one user-defined conversion when user specifies a 1425 // From->ToType conversion via an static cast (c-style, etc). 1426 AddOverloadCandidate(Constructor, &From, 1, CandidateSet, 1427 /*SuppressUserConversions=*/!UserCast, 1428 ForceRValue); 1429 } 1430 } 1431 } 1432 } 1433 1434 if (!AllowConversionFunctions) { 1435 // Don't allow any conversion functions to enter the overload set. 1436 } else if (RequireCompleteType(From->getLocStart(), From->getType(), 1437 PDiag(0) 1438 << From->getSourceRange())) { 1439 // No conversion functions from incomplete types. 1440 } else if (const RecordType *FromRecordType 1441 = From->getType()->getAs<RecordType>()) { 1442 if (CXXRecordDecl *FromRecordDecl 1443 = dyn_cast<CXXRecordDecl>(FromRecordType->getDecl())) { 1444 // Add all of the conversion functions as candidates. 1445 OverloadedFunctionDecl *Conversions 1446 = FromRecordDecl->getVisibleConversionFunctions(); 1447 for (OverloadedFunctionDecl::function_iterator Func 1448 = Conversions->function_begin(); 1449 Func != Conversions->function_end(); ++Func) { 1450 CXXConversionDecl *Conv; 1451 FunctionTemplateDecl *ConvTemplate; 1452 GetFunctionAndTemplate(*Func, Conv, ConvTemplate); 1453 if (ConvTemplate) 1454 Conv = dyn_cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 1455 else 1456 Conv = dyn_cast<CXXConversionDecl>(*Func); 1457 1458 if (AllowExplicit || !Conv->isExplicit()) { 1459 if (ConvTemplate) 1460 AddTemplateConversionCandidate(ConvTemplate, From, ToType, 1461 CandidateSet); 1462 else 1463 AddConversionCandidate(Conv, From, ToType, CandidateSet); 1464 } 1465 } 1466 } 1467 } 1468 1469 OverloadCandidateSet::iterator Best; 1470 switch (BestViableFunction(CandidateSet, From->getLocStart(), Best)) { 1471 case OR_Success: 1472 // Record the standard conversion we used and the conversion function. 1473 if (CXXConstructorDecl *Constructor 1474 = dyn_cast<CXXConstructorDecl>(Best->Function)) { 1475 // C++ [over.ics.user]p1: 1476 // If the user-defined conversion is specified by a 1477 // constructor (12.3.1), the initial standard conversion 1478 // sequence converts the source type to the type required by 1479 // the argument of the constructor. 1480 // 1481 // FIXME: What about ellipsis conversions? 1482 QualType ThisType = Constructor->getThisType(Context); 1483 User.Before = Best->Conversions[0].Standard; 1484 User.ConversionFunction = Constructor; 1485 User.After.setAsIdentityConversion(); 1486 User.After.FromTypePtr 1487 = ThisType->getAs<PointerType>()->getPointeeType().getAsOpaquePtr(); 1488 User.After.ToTypePtr = ToType.getAsOpaquePtr(); 1489 return OR_Success; 1490 } else if (CXXConversionDecl *Conversion 1491 = dyn_cast<CXXConversionDecl>(Best->Function)) { 1492 // C++ [over.ics.user]p1: 1493 // 1494 // [...] If the user-defined conversion is specified by a 1495 // conversion function (12.3.2), the initial standard 1496 // conversion sequence converts the source type to the 1497 // implicit object parameter of the conversion function. 1498 User.Before = Best->Conversions[0].Standard; 1499 User.ConversionFunction = Conversion; 1500 1501 // C++ [over.ics.user]p2: 1502 // The second standard conversion sequence converts the 1503 // result of the user-defined conversion to the target type 1504 // for the sequence. Since an implicit conversion sequence 1505 // is an initialization, the special rules for 1506 // initialization by user-defined conversion apply when 1507 // selecting the best user-defined conversion for a 1508 // user-defined conversion sequence (see 13.3.3 and 1509 // 13.3.3.1). 1510 User.After = Best->FinalConversion; 1511 return OR_Success; 1512 } else { 1513 assert(false && "Not a constructor or conversion function?"); 1514 return OR_No_Viable_Function; 1515 } 1516 1517 case OR_No_Viable_Function: 1518 return OR_No_Viable_Function; 1519 case OR_Deleted: 1520 // No conversion here! We're done. 1521 return OR_Deleted; 1522 1523 case OR_Ambiguous: 1524 return OR_Ambiguous; 1525 } 1526 1527 return OR_No_Viable_Function; 1528} 1529 1530bool 1531Sema::DiagnoseAmbiguousUserDefinedConversion(Expr *From, QualType ToType) { 1532 ImplicitConversionSequence ICS; 1533 OverloadCandidateSet CandidateSet; 1534 OverloadingResult OvResult = 1535 IsUserDefinedConversion(From, ToType, ICS.UserDefined, 1536 CandidateSet, true, false, false); 1537 if (OvResult != OR_Ambiguous) 1538 return false; 1539 Diag(From->getSourceRange().getBegin(), 1540 diag::err_typecheck_ambiguous_condition) 1541 << From->getType() << ToType << From->getSourceRange(); 1542 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 1543 return true; 1544} 1545 1546/// CompareImplicitConversionSequences - Compare two implicit 1547/// conversion sequences to determine whether one is better than the 1548/// other or if they are indistinguishable (C++ 13.3.3.2). 1549ImplicitConversionSequence::CompareKind 1550Sema::CompareImplicitConversionSequences(const ImplicitConversionSequence& ICS1, 1551 const ImplicitConversionSequence& ICS2) 1552{ 1553 // (C++ 13.3.3.2p2): When comparing the basic forms of implicit 1554 // conversion sequences (as defined in 13.3.3.1) 1555 // -- a standard conversion sequence (13.3.3.1.1) is a better 1556 // conversion sequence than a user-defined conversion sequence or 1557 // an ellipsis conversion sequence, and 1558 // -- a user-defined conversion sequence (13.3.3.1.2) is a better 1559 // conversion sequence than an ellipsis conversion sequence 1560 // (13.3.3.1.3). 1561 // 1562 if (ICS1.ConversionKind < ICS2.ConversionKind) 1563 return ImplicitConversionSequence::Better; 1564 else if (ICS2.ConversionKind < ICS1.ConversionKind) 1565 return ImplicitConversionSequence::Worse; 1566 1567 // Two implicit conversion sequences of the same form are 1568 // indistinguishable conversion sequences unless one of the 1569 // following rules apply: (C++ 13.3.3.2p3): 1570 if (ICS1.ConversionKind == ImplicitConversionSequence::StandardConversion) 1571 return CompareStandardConversionSequences(ICS1.Standard, ICS2.Standard); 1572 else if (ICS1.ConversionKind == 1573 ImplicitConversionSequence::UserDefinedConversion) { 1574 // User-defined conversion sequence U1 is a better conversion 1575 // sequence than another user-defined conversion sequence U2 if 1576 // they contain the same user-defined conversion function or 1577 // constructor and if the second standard conversion sequence of 1578 // U1 is better than the second standard conversion sequence of 1579 // U2 (C++ 13.3.3.2p3). 1580 if (ICS1.UserDefined.ConversionFunction == 1581 ICS2.UserDefined.ConversionFunction) 1582 return CompareStandardConversionSequences(ICS1.UserDefined.After, 1583 ICS2.UserDefined.After); 1584 } 1585 1586 return ImplicitConversionSequence::Indistinguishable; 1587} 1588 1589/// CompareStandardConversionSequences - Compare two standard 1590/// conversion sequences to determine whether one is better than the 1591/// other or if they are indistinguishable (C++ 13.3.3.2p3). 1592ImplicitConversionSequence::CompareKind 1593Sema::CompareStandardConversionSequences(const StandardConversionSequence& SCS1, 1594 const StandardConversionSequence& SCS2) 1595{ 1596 // Standard conversion sequence S1 is a better conversion sequence 1597 // than standard conversion sequence S2 if (C++ 13.3.3.2p3): 1598 1599 // -- S1 is a proper subsequence of S2 (comparing the conversion 1600 // sequences in the canonical form defined by 13.3.3.1.1, 1601 // excluding any Lvalue Transformation; the identity conversion 1602 // sequence is considered to be a subsequence of any 1603 // non-identity conversion sequence) or, if not that, 1604 if (SCS1.Second == SCS2.Second && SCS1.Third == SCS2.Third) 1605 // Neither is a proper subsequence of the other. Do nothing. 1606 ; 1607 else if ((SCS1.Second == ICK_Identity && SCS1.Third == SCS2.Third) || 1608 (SCS1.Third == ICK_Identity && SCS1.Second == SCS2.Second) || 1609 (SCS1.Second == ICK_Identity && 1610 SCS1.Third == ICK_Identity)) 1611 // SCS1 is a proper subsequence of SCS2. 1612 return ImplicitConversionSequence::Better; 1613 else if ((SCS2.Second == ICK_Identity && SCS2.Third == SCS1.Third) || 1614 (SCS2.Third == ICK_Identity && SCS2.Second == SCS1.Second) || 1615 (SCS2.Second == ICK_Identity && 1616 SCS2.Third == ICK_Identity)) 1617 // SCS2 is a proper subsequence of SCS1. 1618 return ImplicitConversionSequence::Worse; 1619 1620 // -- the rank of S1 is better than the rank of S2 (by the rules 1621 // defined below), or, if not that, 1622 ImplicitConversionRank Rank1 = SCS1.getRank(); 1623 ImplicitConversionRank Rank2 = SCS2.getRank(); 1624 if (Rank1 < Rank2) 1625 return ImplicitConversionSequence::Better; 1626 else if (Rank2 < Rank1) 1627 return ImplicitConversionSequence::Worse; 1628 1629 // (C++ 13.3.3.2p4): Two conversion sequences with the same rank 1630 // are indistinguishable unless one of the following rules 1631 // applies: 1632 1633 // A conversion that is not a conversion of a pointer, or 1634 // pointer to member, to bool is better than another conversion 1635 // that is such a conversion. 1636 if (SCS1.isPointerConversionToBool() != SCS2.isPointerConversionToBool()) 1637 return SCS2.isPointerConversionToBool() 1638 ? ImplicitConversionSequence::Better 1639 : ImplicitConversionSequence::Worse; 1640 1641 // C++ [over.ics.rank]p4b2: 1642 // 1643 // If class B is derived directly or indirectly from class A, 1644 // conversion of B* to A* is better than conversion of B* to 1645 // void*, and conversion of A* to void* is better than conversion 1646 // of B* to void*. 1647 bool SCS1ConvertsToVoid 1648 = SCS1.isPointerConversionToVoidPointer(Context); 1649 bool SCS2ConvertsToVoid 1650 = SCS2.isPointerConversionToVoidPointer(Context); 1651 if (SCS1ConvertsToVoid != SCS2ConvertsToVoid) { 1652 // Exactly one of the conversion sequences is a conversion to 1653 // a void pointer; it's the worse conversion. 1654 return SCS2ConvertsToVoid ? ImplicitConversionSequence::Better 1655 : ImplicitConversionSequence::Worse; 1656 } else if (!SCS1ConvertsToVoid && !SCS2ConvertsToVoid) { 1657 // Neither conversion sequence converts to a void pointer; compare 1658 // their derived-to-base conversions. 1659 if (ImplicitConversionSequence::CompareKind DerivedCK 1660 = CompareDerivedToBaseConversions(SCS1, SCS2)) 1661 return DerivedCK; 1662 } else if (SCS1ConvertsToVoid && SCS2ConvertsToVoid) { 1663 // Both conversion sequences are conversions to void 1664 // pointers. Compare the source types to determine if there's an 1665 // inheritance relationship in their sources. 1666 QualType FromType1 = QualType::getFromOpaquePtr(SCS1.FromTypePtr); 1667 QualType FromType2 = QualType::getFromOpaquePtr(SCS2.FromTypePtr); 1668 1669 // Adjust the types we're converting from via the array-to-pointer 1670 // conversion, if we need to. 1671 if (SCS1.First == ICK_Array_To_Pointer) 1672 FromType1 = Context.getArrayDecayedType(FromType1); 1673 if (SCS2.First == ICK_Array_To_Pointer) 1674 FromType2 = Context.getArrayDecayedType(FromType2); 1675 1676 QualType FromPointee1 1677 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1678 QualType FromPointee2 1679 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1680 1681 if (IsDerivedFrom(FromPointee2, FromPointee1)) 1682 return ImplicitConversionSequence::Better; 1683 else if (IsDerivedFrom(FromPointee1, FromPointee2)) 1684 return ImplicitConversionSequence::Worse; 1685 1686 // Objective-C++: If one interface is more specific than the 1687 // other, it is the better one. 1688 const ObjCInterfaceType* FromIface1 = FromPointee1->getAs<ObjCInterfaceType>(); 1689 const ObjCInterfaceType* FromIface2 = FromPointee2->getAs<ObjCInterfaceType>(); 1690 if (FromIface1 && FromIface1) { 1691 if (Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 1692 return ImplicitConversionSequence::Better; 1693 else if (Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 1694 return ImplicitConversionSequence::Worse; 1695 } 1696 } 1697 1698 // Compare based on qualification conversions (C++ 13.3.3.2p3, 1699 // bullet 3). 1700 if (ImplicitConversionSequence::CompareKind QualCK 1701 = CompareQualificationConversions(SCS1, SCS2)) 1702 return QualCK; 1703 1704 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding) { 1705 // C++0x [over.ics.rank]p3b4: 1706 // -- S1 and S2 are reference bindings (8.5.3) and neither refers to an 1707 // implicit object parameter of a non-static member function declared 1708 // without a ref-qualifier, and S1 binds an rvalue reference to an 1709 // rvalue and S2 binds an lvalue reference. 1710 // FIXME: We don't know if we're dealing with the implicit object parameter, 1711 // or if the member function in this case has a ref qualifier. 1712 // (Of course, we don't have ref qualifiers yet.) 1713 if (SCS1.RRefBinding != SCS2.RRefBinding) 1714 return SCS1.RRefBinding ? ImplicitConversionSequence::Better 1715 : ImplicitConversionSequence::Worse; 1716 1717 // C++ [over.ics.rank]p3b4: 1718 // -- S1 and S2 are reference bindings (8.5.3), and the types to 1719 // which the references refer are the same type except for 1720 // top-level cv-qualifiers, and the type to which the reference 1721 // initialized by S2 refers is more cv-qualified than the type 1722 // to which the reference initialized by S1 refers. 1723 QualType T1 = QualType::getFromOpaquePtr(SCS1.ToTypePtr); 1724 QualType T2 = QualType::getFromOpaquePtr(SCS2.ToTypePtr); 1725 T1 = Context.getCanonicalType(T1); 1726 T2 = Context.getCanonicalType(T2); 1727 if (T1.getUnqualifiedType() == T2.getUnqualifiedType()) { 1728 if (T2.isMoreQualifiedThan(T1)) 1729 return ImplicitConversionSequence::Better; 1730 else if (T1.isMoreQualifiedThan(T2)) 1731 return ImplicitConversionSequence::Worse; 1732 } 1733 } 1734 1735 return ImplicitConversionSequence::Indistinguishable; 1736} 1737 1738/// CompareQualificationConversions - Compares two standard conversion 1739/// sequences to determine whether they can be ranked based on their 1740/// qualification conversions (C++ 13.3.3.2p3 bullet 3). 1741ImplicitConversionSequence::CompareKind 1742Sema::CompareQualificationConversions(const StandardConversionSequence& SCS1, 1743 const StandardConversionSequence& SCS2) { 1744 // C++ 13.3.3.2p3: 1745 // -- S1 and S2 differ only in their qualification conversion and 1746 // yield similar types T1 and T2 (C++ 4.4), respectively, and the 1747 // cv-qualification signature of type T1 is a proper subset of 1748 // the cv-qualification signature of type T2, and S1 is not the 1749 // deprecated string literal array-to-pointer conversion (4.2). 1750 if (SCS1.First != SCS2.First || SCS1.Second != SCS2.Second || 1751 SCS1.Third != SCS2.Third || SCS1.Third != ICK_Qualification) 1752 return ImplicitConversionSequence::Indistinguishable; 1753 1754 // FIXME: the example in the standard doesn't use a qualification 1755 // conversion (!) 1756 QualType T1 = QualType::getFromOpaquePtr(SCS1.ToTypePtr); 1757 QualType T2 = QualType::getFromOpaquePtr(SCS2.ToTypePtr); 1758 T1 = Context.getCanonicalType(T1); 1759 T2 = Context.getCanonicalType(T2); 1760 1761 // If the types are the same, we won't learn anything by unwrapped 1762 // them. 1763 if (T1.getUnqualifiedType() == T2.getUnqualifiedType()) 1764 return ImplicitConversionSequence::Indistinguishable; 1765 1766 ImplicitConversionSequence::CompareKind Result 1767 = ImplicitConversionSequence::Indistinguishable; 1768 while (UnwrapSimilarPointerTypes(T1, T2)) { 1769 // Within each iteration of the loop, we check the qualifiers to 1770 // determine if this still looks like a qualification 1771 // conversion. Then, if all is well, we unwrap one more level of 1772 // pointers or pointers-to-members and do it all again 1773 // until there are no more pointers or pointers-to-members left 1774 // to unwrap. This essentially mimics what 1775 // IsQualificationConversion does, but here we're checking for a 1776 // strict subset of qualifiers. 1777 if (T1.getCVRQualifiers() == T2.getCVRQualifiers()) 1778 // The qualifiers are the same, so this doesn't tell us anything 1779 // about how the sequences rank. 1780 ; 1781 else if (T2.isMoreQualifiedThan(T1)) { 1782 // T1 has fewer qualifiers, so it could be the better sequence. 1783 if (Result == ImplicitConversionSequence::Worse) 1784 // Neither has qualifiers that are a subset of the other's 1785 // qualifiers. 1786 return ImplicitConversionSequence::Indistinguishable; 1787 1788 Result = ImplicitConversionSequence::Better; 1789 } else if (T1.isMoreQualifiedThan(T2)) { 1790 // T2 has fewer qualifiers, so it could be the better sequence. 1791 if (Result == ImplicitConversionSequence::Better) 1792 // Neither has qualifiers that are a subset of the other's 1793 // qualifiers. 1794 return ImplicitConversionSequence::Indistinguishable; 1795 1796 Result = ImplicitConversionSequence::Worse; 1797 } else { 1798 // Qualifiers are disjoint. 1799 return ImplicitConversionSequence::Indistinguishable; 1800 } 1801 1802 // If the types after this point are equivalent, we're done. 1803 if (T1.getUnqualifiedType() == T2.getUnqualifiedType()) 1804 break; 1805 } 1806 1807 // Check that the winning standard conversion sequence isn't using 1808 // the deprecated string literal array to pointer conversion. 1809 switch (Result) { 1810 case ImplicitConversionSequence::Better: 1811 if (SCS1.Deprecated) 1812 Result = ImplicitConversionSequence::Indistinguishable; 1813 break; 1814 1815 case ImplicitConversionSequence::Indistinguishable: 1816 break; 1817 1818 case ImplicitConversionSequence::Worse: 1819 if (SCS2.Deprecated) 1820 Result = ImplicitConversionSequence::Indistinguishable; 1821 break; 1822 } 1823 1824 return Result; 1825} 1826 1827/// CompareDerivedToBaseConversions - Compares two standard conversion 1828/// sequences to determine whether they can be ranked based on their 1829/// various kinds of derived-to-base conversions (C++ 1830/// [over.ics.rank]p4b3). As part of these checks, we also look at 1831/// conversions between Objective-C interface types. 1832ImplicitConversionSequence::CompareKind 1833Sema::CompareDerivedToBaseConversions(const StandardConversionSequence& SCS1, 1834 const StandardConversionSequence& SCS2) { 1835 QualType FromType1 = QualType::getFromOpaquePtr(SCS1.FromTypePtr); 1836 QualType ToType1 = QualType::getFromOpaquePtr(SCS1.ToTypePtr); 1837 QualType FromType2 = QualType::getFromOpaquePtr(SCS2.FromTypePtr); 1838 QualType ToType2 = QualType::getFromOpaquePtr(SCS2.ToTypePtr); 1839 1840 // Adjust the types we're converting from via the array-to-pointer 1841 // conversion, if we need to. 1842 if (SCS1.First == ICK_Array_To_Pointer) 1843 FromType1 = Context.getArrayDecayedType(FromType1); 1844 if (SCS2.First == ICK_Array_To_Pointer) 1845 FromType2 = Context.getArrayDecayedType(FromType2); 1846 1847 // Canonicalize all of the types. 1848 FromType1 = Context.getCanonicalType(FromType1); 1849 ToType1 = Context.getCanonicalType(ToType1); 1850 FromType2 = Context.getCanonicalType(FromType2); 1851 ToType2 = Context.getCanonicalType(ToType2); 1852 1853 // C++ [over.ics.rank]p4b3: 1854 // 1855 // If class B is derived directly or indirectly from class A and 1856 // class C is derived directly or indirectly from B, 1857 // 1858 // For Objective-C, we let A, B, and C also be Objective-C 1859 // interfaces. 1860 1861 // Compare based on pointer conversions. 1862 if (SCS1.Second == ICK_Pointer_Conversion && 1863 SCS2.Second == ICK_Pointer_Conversion && 1864 /*FIXME: Remove if Objective-C id conversions get their own rank*/ 1865 FromType1->isPointerType() && FromType2->isPointerType() && 1866 ToType1->isPointerType() && ToType2->isPointerType()) { 1867 QualType FromPointee1 1868 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1869 QualType ToPointee1 1870 = ToType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1871 QualType FromPointee2 1872 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1873 QualType ToPointee2 1874 = ToType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1875 1876 const ObjCInterfaceType* FromIface1 = FromPointee1->getAs<ObjCInterfaceType>(); 1877 const ObjCInterfaceType* FromIface2 = FromPointee2->getAs<ObjCInterfaceType>(); 1878 const ObjCInterfaceType* ToIface1 = ToPointee1->getAs<ObjCInterfaceType>(); 1879 const ObjCInterfaceType* ToIface2 = ToPointee2->getAs<ObjCInterfaceType>(); 1880 1881 // -- conversion of C* to B* is better than conversion of C* to A*, 1882 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 1883 if (IsDerivedFrom(ToPointee1, ToPointee2)) 1884 return ImplicitConversionSequence::Better; 1885 else if (IsDerivedFrom(ToPointee2, ToPointee1)) 1886 return ImplicitConversionSequence::Worse; 1887 1888 if (ToIface1 && ToIface2) { 1889 if (Context.canAssignObjCInterfaces(ToIface2, ToIface1)) 1890 return ImplicitConversionSequence::Better; 1891 else if (Context.canAssignObjCInterfaces(ToIface1, ToIface2)) 1892 return ImplicitConversionSequence::Worse; 1893 } 1894 } 1895 1896 // -- conversion of B* to A* is better than conversion of C* to A*, 1897 if (FromPointee1 != FromPointee2 && ToPointee1 == ToPointee2) { 1898 if (IsDerivedFrom(FromPointee2, FromPointee1)) 1899 return ImplicitConversionSequence::Better; 1900 else if (IsDerivedFrom(FromPointee1, FromPointee2)) 1901 return ImplicitConversionSequence::Worse; 1902 1903 if (FromIface1 && FromIface2) { 1904 if (Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 1905 return ImplicitConversionSequence::Better; 1906 else if (Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 1907 return ImplicitConversionSequence::Worse; 1908 } 1909 } 1910 } 1911 1912 // Compare based on reference bindings. 1913 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding && 1914 SCS1.Second == ICK_Derived_To_Base) { 1915 // -- binding of an expression of type C to a reference of type 1916 // B& is better than binding an expression of type C to a 1917 // reference of type A&, 1918 if (FromType1.getUnqualifiedType() == FromType2.getUnqualifiedType() && 1919 ToType1.getUnqualifiedType() != ToType2.getUnqualifiedType()) { 1920 if (IsDerivedFrom(ToType1, ToType2)) 1921 return ImplicitConversionSequence::Better; 1922 else if (IsDerivedFrom(ToType2, ToType1)) 1923 return ImplicitConversionSequence::Worse; 1924 } 1925 1926 // -- binding of an expression of type B to a reference of type 1927 // A& is better than binding an expression of type C to a 1928 // reference of type A&, 1929 if (FromType1.getUnqualifiedType() != FromType2.getUnqualifiedType() && 1930 ToType1.getUnqualifiedType() == ToType2.getUnqualifiedType()) { 1931 if (IsDerivedFrom(FromType2, FromType1)) 1932 return ImplicitConversionSequence::Better; 1933 else if (IsDerivedFrom(FromType1, FromType2)) 1934 return ImplicitConversionSequence::Worse; 1935 } 1936 } 1937 1938 1939 // FIXME: conversion of A::* to B::* is better than conversion of 1940 // A::* to C::*, 1941 1942 // FIXME: conversion of B::* to C::* is better than conversion of 1943 // A::* to C::*, and 1944 1945 if (SCS1.CopyConstructor && SCS2.CopyConstructor && 1946 SCS1.Second == ICK_Derived_To_Base) { 1947 // -- conversion of C to B is better than conversion of C to A, 1948 if (FromType1.getUnqualifiedType() == FromType2.getUnqualifiedType() && 1949 ToType1.getUnqualifiedType() != ToType2.getUnqualifiedType()) { 1950 if (IsDerivedFrom(ToType1, ToType2)) 1951 return ImplicitConversionSequence::Better; 1952 else if (IsDerivedFrom(ToType2, ToType1)) 1953 return ImplicitConversionSequence::Worse; 1954 } 1955 1956 // -- conversion of B to A is better than conversion of C to A. 1957 if (FromType1.getUnqualifiedType() != FromType2.getUnqualifiedType() && 1958 ToType1.getUnqualifiedType() == ToType2.getUnqualifiedType()) { 1959 if (IsDerivedFrom(FromType2, FromType1)) 1960 return ImplicitConversionSequence::Better; 1961 else if (IsDerivedFrom(FromType1, FromType2)) 1962 return ImplicitConversionSequence::Worse; 1963 } 1964 } 1965 1966 return ImplicitConversionSequence::Indistinguishable; 1967} 1968 1969/// TryCopyInitialization - Try to copy-initialize a value of type 1970/// ToType from the expression From. Return the implicit conversion 1971/// sequence required to pass this argument, which may be a bad 1972/// conversion sequence (meaning that the argument cannot be passed to 1973/// a parameter of this type). If @p SuppressUserConversions, then we 1974/// do not permit any user-defined conversion sequences. If @p ForceRValue, 1975/// then we treat @p From as an rvalue, even if it is an lvalue. 1976ImplicitConversionSequence 1977Sema::TryCopyInitialization(Expr *From, QualType ToType, 1978 bool SuppressUserConversions, bool ForceRValue, 1979 bool InOverloadResolution) { 1980 if (ToType->isReferenceType()) { 1981 ImplicitConversionSequence ICS; 1982 CheckReferenceInit(From, ToType, 1983 /*FIXME:*/From->getLocStart(), 1984 SuppressUserConversions, 1985 /*AllowExplicit=*/false, 1986 ForceRValue, 1987 &ICS); 1988 return ICS; 1989 } else { 1990 return TryImplicitConversion(From, ToType, 1991 SuppressUserConversions, 1992 /*AllowExplicit=*/false, 1993 ForceRValue, 1994 InOverloadResolution); 1995 } 1996} 1997 1998/// PerformCopyInitialization - Copy-initialize an object of type @p ToType with 1999/// the expression @p From. Returns true (and emits a diagnostic) if there was 2000/// an error, returns false if the initialization succeeded. Elidable should 2001/// be true when the copy may be elided (C++ 12.8p15). Overload resolution works 2002/// differently in C++0x for this case. 2003bool Sema::PerformCopyInitialization(Expr *&From, QualType ToType, 2004 const char* Flavor, bool Elidable) { 2005 if (!getLangOptions().CPlusPlus) { 2006 // In C, argument passing is the same as performing an assignment. 2007 QualType FromType = From->getType(); 2008 2009 AssignConvertType ConvTy = 2010 CheckSingleAssignmentConstraints(ToType, From); 2011 if (ConvTy != Compatible && 2012 CheckTransparentUnionArgumentConstraints(ToType, From) == Compatible) 2013 ConvTy = Compatible; 2014 2015 return DiagnoseAssignmentResult(ConvTy, From->getLocStart(), ToType, 2016 FromType, From, Flavor); 2017 } 2018 2019 if (ToType->isReferenceType()) 2020 return CheckReferenceInit(From, ToType, 2021 /*FIXME:*/From->getLocStart(), 2022 /*SuppressUserConversions=*/false, 2023 /*AllowExplicit=*/false, 2024 /*ForceRValue=*/false); 2025 2026 if (!PerformImplicitConversion(From, ToType, Flavor, 2027 /*AllowExplicit=*/false, Elidable)) 2028 return false; 2029 if (!DiagnoseAmbiguousUserDefinedConversion(From, ToType)) 2030 return Diag(From->getSourceRange().getBegin(), 2031 diag::err_typecheck_convert_incompatible) 2032 << ToType << From->getType() << Flavor << From->getSourceRange(); 2033 return true; 2034} 2035 2036/// TryObjectArgumentInitialization - Try to initialize the object 2037/// parameter of the given member function (@c Method) from the 2038/// expression @p From. 2039ImplicitConversionSequence 2040Sema::TryObjectArgumentInitialization(Expr *From, CXXMethodDecl *Method) { 2041 QualType ClassType = Context.getTypeDeclType(Method->getParent()); 2042 QualType ImplicitParamType 2043 = Context.getCVRQualifiedType(ClassType, Method->getTypeQualifiers()); 2044 2045 // Set up the conversion sequence as a "bad" conversion, to allow us 2046 // to exit early. 2047 ImplicitConversionSequence ICS; 2048 ICS.Standard.setAsIdentityConversion(); 2049 ICS.ConversionKind = ImplicitConversionSequence::BadConversion; 2050 2051 // We need to have an object of class type. 2052 QualType FromType = From->getType(); 2053 if (const PointerType *PT = FromType->getAs<PointerType>()) 2054 FromType = PT->getPointeeType(); 2055 2056 assert(FromType->isRecordType()); 2057 2058 // The implicit object parmeter is has the type "reference to cv X", 2059 // where X is the class of which the function is a member 2060 // (C++ [over.match.funcs]p4). However, when finding an implicit 2061 // conversion sequence for the argument, we are not allowed to 2062 // create temporaries or perform user-defined conversions 2063 // (C++ [over.match.funcs]p5). We perform a simplified version of 2064 // reference binding here, that allows class rvalues to bind to 2065 // non-constant references. 2066 2067 // First check the qualifiers. We don't care about lvalue-vs-rvalue 2068 // with the implicit object parameter (C++ [over.match.funcs]p5). 2069 QualType FromTypeCanon = Context.getCanonicalType(FromType); 2070 if (ImplicitParamType.getCVRQualifiers() != FromType.getCVRQualifiers() && 2071 !ImplicitParamType.isAtLeastAsQualifiedAs(FromType)) 2072 return ICS; 2073 2074 // Check that we have either the same type or a derived type. It 2075 // affects the conversion rank. 2076 QualType ClassTypeCanon = Context.getCanonicalType(ClassType); 2077 if (ClassTypeCanon == FromTypeCanon.getUnqualifiedType()) 2078 ICS.Standard.Second = ICK_Identity; 2079 else if (IsDerivedFrom(FromType, ClassType)) 2080 ICS.Standard.Second = ICK_Derived_To_Base; 2081 else 2082 return ICS; 2083 2084 // Success. Mark this as a reference binding. 2085 ICS.ConversionKind = ImplicitConversionSequence::StandardConversion; 2086 ICS.Standard.FromTypePtr = FromType.getAsOpaquePtr(); 2087 ICS.Standard.ToTypePtr = ImplicitParamType.getAsOpaquePtr(); 2088 ICS.Standard.ReferenceBinding = true; 2089 ICS.Standard.DirectBinding = true; 2090 ICS.Standard.RRefBinding = false; 2091 return ICS; 2092} 2093 2094/// PerformObjectArgumentInitialization - Perform initialization of 2095/// the implicit object parameter for the given Method with the given 2096/// expression. 2097bool 2098Sema::PerformObjectArgumentInitialization(Expr *&From, CXXMethodDecl *Method) { 2099 QualType FromRecordType, DestType; 2100 QualType ImplicitParamRecordType = 2101 Method->getThisType(Context)->getAs<PointerType>()->getPointeeType(); 2102 2103 if (const PointerType *PT = From->getType()->getAs<PointerType>()) { 2104 FromRecordType = PT->getPointeeType(); 2105 DestType = Method->getThisType(Context); 2106 } else { 2107 FromRecordType = From->getType(); 2108 DestType = ImplicitParamRecordType; 2109 } 2110 2111 ImplicitConversionSequence ICS 2112 = TryObjectArgumentInitialization(From, Method); 2113 if (ICS.ConversionKind == ImplicitConversionSequence::BadConversion) 2114 return Diag(From->getSourceRange().getBegin(), 2115 diag::err_implicit_object_parameter_init) 2116 << ImplicitParamRecordType << FromRecordType << From->getSourceRange(); 2117 2118 if (ICS.Standard.Second == ICK_Derived_To_Base && 2119 CheckDerivedToBaseConversion(FromRecordType, 2120 ImplicitParamRecordType, 2121 From->getSourceRange().getBegin(), 2122 From->getSourceRange())) 2123 return true; 2124 2125 ImpCastExprToType(From, DestType, CastExpr::CK_DerivedToBase, 2126 /*isLvalue=*/true); 2127 return false; 2128} 2129 2130/// TryContextuallyConvertToBool - Attempt to contextually convert the 2131/// expression From to bool (C++0x [conv]p3). 2132ImplicitConversionSequence Sema::TryContextuallyConvertToBool(Expr *From) { 2133 return TryImplicitConversion(From, Context.BoolTy, 2134 // FIXME: Are these flags correct? 2135 /*SuppressUserConversions=*/false, 2136 /*AllowExplicit=*/true, 2137 /*ForceRValue=*/false, 2138 /*InOverloadResolution=*/false); 2139} 2140 2141/// PerformContextuallyConvertToBool - Perform a contextual conversion 2142/// of the expression From to bool (C++0x [conv]p3). 2143bool Sema::PerformContextuallyConvertToBool(Expr *&From) { 2144 ImplicitConversionSequence ICS = TryContextuallyConvertToBool(From); 2145 if (!PerformImplicitConversion(From, Context.BoolTy, ICS, "converting")) 2146 return false; 2147 2148 if (!DiagnoseAmbiguousUserDefinedConversion(From, Context.BoolTy)) 2149 return Diag(From->getSourceRange().getBegin(), 2150 diag::err_typecheck_bool_condition) 2151 << From->getType() << From->getSourceRange(); 2152 return true; 2153} 2154 2155/// AddOverloadCandidate - Adds the given function to the set of 2156/// candidate functions, using the given function call arguments. If 2157/// @p SuppressUserConversions, then don't allow user-defined 2158/// conversions via constructors or conversion operators. 2159/// If @p ForceRValue, treat all arguments as rvalues. This is a slightly 2160/// hacky way to implement the overloading rules for elidable copy 2161/// initialization in C++0x (C++0x 12.8p15). 2162/// 2163/// \para PartialOverloading true if we are performing "partial" overloading 2164/// based on an incomplete set of function arguments. This feature is used by 2165/// code completion. 2166void 2167Sema::AddOverloadCandidate(FunctionDecl *Function, 2168 Expr **Args, unsigned NumArgs, 2169 OverloadCandidateSet& CandidateSet, 2170 bool SuppressUserConversions, 2171 bool ForceRValue, 2172 bool PartialOverloading) { 2173 const FunctionProtoType* Proto 2174 = dyn_cast<FunctionProtoType>(Function->getType()->getAs<FunctionType>()); 2175 assert(Proto && "Functions without a prototype cannot be overloaded"); 2176 assert(!isa<CXXConversionDecl>(Function) && 2177 "Use AddConversionCandidate for conversion functions"); 2178 assert(!Function->getDescribedFunctionTemplate() && 2179 "Use AddTemplateOverloadCandidate for function templates"); 2180 2181 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Function)) { 2182 if (!isa<CXXConstructorDecl>(Method)) { 2183 // If we get here, it's because we're calling a member function 2184 // that is named without a member access expression (e.g., 2185 // "this->f") that was either written explicitly or created 2186 // implicitly. This can happen with a qualified call to a member 2187 // function, e.g., X::f(). We use a NULL object as the implied 2188 // object argument (C++ [over.call.func]p3). 2189 AddMethodCandidate(Method, 0, Args, NumArgs, CandidateSet, 2190 SuppressUserConversions, ForceRValue); 2191 return; 2192 } 2193 // We treat a constructor like a non-member function, since its object 2194 // argument doesn't participate in overload resolution. 2195 } 2196 2197 if (!CandidateSet.isNewCandidate(Function)) 2198 return; 2199 2200 // Add this candidate 2201 CandidateSet.push_back(OverloadCandidate()); 2202 OverloadCandidate& Candidate = CandidateSet.back(); 2203 Candidate.Function = Function; 2204 Candidate.Viable = true; 2205 Candidate.IsSurrogate = false; 2206 Candidate.IgnoreObjectArgument = false; 2207 2208 unsigned NumArgsInProto = Proto->getNumArgs(); 2209 2210 // (C++ 13.3.2p2): A candidate function having fewer than m 2211 // parameters is viable only if it has an ellipsis in its parameter 2212 // list (8.3.5). 2213 if ((NumArgs + (PartialOverloading && NumArgs)) > NumArgsInProto && 2214 !Proto->isVariadic()) { 2215 Candidate.Viable = false; 2216 return; 2217 } 2218 2219 // (C++ 13.3.2p2): A candidate function having more than m parameters 2220 // is viable only if the (m+1)st parameter has a default argument 2221 // (8.3.6). For the purposes of overload resolution, the 2222 // parameter list is truncated on the right, so that there are 2223 // exactly m parameters. 2224 unsigned MinRequiredArgs = Function->getMinRequiredArguments(); 2225 if (NumArgs < MinRequiredArgs && !PartialOverloading) { 2226 // Not enough arguments. 2227 Candidate.Viable = false; 2228 return; 2229 } 2230 2231 // Determine the implicit conversion sequences for each of the 2232 // arguments. 2233 Candidate.Conversions.resize(NumArgs); 2234 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2235 if (ArgIdx < NumArgsInProto) { 2236 // (C++ 13.3.2p3): for F to be a viable function, there shall 2237 // exist for each argument an implicit conversion sequence 2238 // (13.3.3.1) that converts that argument to the corresponding 2239 // parameter of F. 2240 QualType ParamType = Proto->getArgType(ArgIdx); 2241 Candidate.Conversions[ArgIdx] 2242 = TryCopyInitialization(Args[ArgIdx], ParamType, 2243 SuppressUserConversions, ForceRValue, 2244 /*InOverloadResolution=*/true); 2245 if (Candidate.Conversions[ArgIdx].ConversionKind 2246 == ImplicitConversionSequence::BadConversion) { 2247 // 13.3.3.1-p10 If several different sequences of conversions exist that 2248 // each convert the argument to the parameter type, the implicit conversion 2249 // sequence associated with the parameter is defined to be the unique conversion 2250 // sequence designated the ambiguous conversion sequence. For the purpose of 2251 // ranking implicit conversion sequences as described in 13.3.3.2, the ambiguous 2252 // conversion sequence is treated as a user-defined sequence that is 2253 // indistinguishable from any other user-defined conversion sequence 2254 if (!Candidate.Conversions[ArgIdx].ConversionFunctionSet.empty()) { 2255 Candidate.Conversions[ArgIdx].ConversionKind = 2256 ImplicitConversionSequence::UserDefinedConversion; 2257 // Set the conversion function to one of them. As due to ambiguity, 2258 // they carry the same weight and is needed for overload resolution 2259 // later. 2260 Candidate.Conversions[ArgIdx].UserDefined.ConversionFunction = 2261 Candidate.Conversions[ArgIdx].ConversionFunctionSet[0]; 2262 } 2263 else { 2264 Candidate.Viable = false; 2265 break; 2266 } 2267 } 2268 } else { 2269 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2270 // argument for which there is no corresponding parameter is 2271 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2272 Candidate.Conversions[ArgIdx].ConversionKind 2273 = ImplicitConversionSequence::EllipsisConversion; 2274 } 2275 } 2276} 2277 2278/// \brief Add all of the function declarations in the given function set to 2279/// the overload canddiate set. 2280void Sema::AddFunctionCandidates(const FunctionSet &Functions, 2281 Expr **Args, unsigned NumArgs, 2282 OverloadCandidateSet& CandidateSet, 2283 bool SuppressUserConversions) { 2284 for (FunctionSet::const_iterator F = Functions.begin(), 2285 FEnd = Functions.end(); 2286 F != FEnd; ++F) { 2287 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*F)) { 2288 if (isa<CXXMethodDecl>(FD) && !cast<CXXMethodDecl>(FD)->isStatic()) 2289 AddMethodCandidate(cast<CXXMethodDecl>(FD), 2290 Args[0], Args + 1, NumArgs - 1, 2291 CandidateSet, SuppressUserConversions); 2292 else 2293 AddOverloadCandidate(FD, Args, NumArgs, CandidateSet, 2294 SuppressUserConversions); 2295 } else { 2296 FunctionTemplateDecl *FunTmpl = cast<FunctionTemplateDecl>(*F); 2297 if (isa<CXXMethodDecl>(FunTmpl->getTemplatedDecl()) && 2298 !cast<CXXMethodDecl>(FunTmpl->getTemplatedDecl())->isStatic()) 2299 AddMethodTemplateCandidate(FunTmpl, 2300 /*FIXME: explicit args */false, 0, 0, 2301 Args[0], Args + 1, NumArgs - 1, 2302 CandidateSet, 2303 SuppressUserConversions); 2304 else 2305 AddTemplateOverloadCandidate(FunTmpl, 2306 /*FIXME: explicit args */false, 0, 0, 2307 Args, NumArgs, CandidateSet, 2308 SuppressUserConversions); 2309 } 2310 } 2311} 2312 2313/// AddMethodCandidate - Adds the given C++ member function to the set 2314/// of candidate functions, using the given function call arguments 2315/// and the object argument (@c Object). For example, in a call 2316/// @c o.f(a1,a2), @c Object will contain @c o and @c Args will contain 2317/// both @c a1 and @c a2. If @p SuppressUserConversions, then don't 2318/// allow user-defined conversions via constructors or conversion 2319/// operators. If @p ForceRValue, treat all arguments as rvalues. This is 2320/// a slightly hacky way to implement the overloading rules for elidable copy 2321/// initialization in C++0x (C++0x 12.8p15). 2322void 2323Sema::AddMethodCandidate(CXXMethodDecl *Method, Expr *Object, 2324 Expr **Args, unsigned NumArgs, 2325 OverloadCandidateSet& CandidateSet, 2326 bool SuppressUserConversions, bool ForceRValue) { 2327 const FunctionProtoType* Proto 2328 = dyn_cast<FunctionProtoType>(Method->getType()->getAs<FunctionType>()); 2329 assert(Proto && "Methods without a prototype cannot be overloaded"); 2330 assert(!isa<CXXConversionDecl>(Method) && 2331 "Use AddConversionCandidate for conversion functions"); 2332 assert(!isa<CXXConstructorDecl>(Method) && 2333 "Use AddOverloadCandidate for constructors"); 2334 2335 if (!CandidateSet.isNewCandidate(Method)) 2336 return; 2337 2338 // Add this candidate 2339 CandidateSet.push_back(OverloadCandidate()); 2340 OverloadCandidate& Candidate = CandidateSet.back(); 2341 Candidate.Function = Method; 2342 Candidate.IsSurrogate = false; 2343 Candidate.IgnoreObjectArgument = false; 2344 2345 unsigned NumArgsInProto = Proto->getNumArgs(); 2346 2347 // (C++ 13.3.2p2): A candidate function having fewer than m 2348 // parameters is viable only if it has an ellipsis in its parameter 2349 // list (8.3.5). 2350 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 2351 Candidate.Viable = false; 2352 return; 2353 } 2354 2355 // (C++ 13.3.2p2): A candidate function having more than m parameters 2356 // is viable only if the (m+1)st parameter has a default argument 2357 // (8.3.6). For the purposes of overload resolution, the 2358 // parameter list is truncated on the right, so that there are 2359 // exactly m parameters. 2360 unsigned MinRequiredArgs = Method->getMinRequiredArguments(); 2361 if (NumArgs < MinRequiredArgs) { 2362 // Not enough arguments. 2363 Candidate.Viable = false; 2364 return; 2365 } 2366 2367 Candidate.Viable = true; 2368 Candidate.Conversions.resize(NumArgs + 1); 2369 2370 if (Method->isStatic() || !Object) 2371 // The implicit object argument is ignored. 2372 Candidate.IgnoreObjectArgument = true; 2373 else { 2374 // Determine the implicit conversion sequence for the object 2375 // parameter. 2376 Candidate.Conversions[0] = TryObjectArgumentInitialization(Object, Method); 2377 if (Candidate.Conversions[0].ConversionKind 2378 == ImplicitConversionSequence::BadConversion) { 2379 Candidate.Viable = false; 2380 return; 2381 } 2382 } 2383 2384 // Determine the implicit conversion sequences for each of the 2385 // arguments. 2386 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2387 if (ArgIdx < NumArgsInProto) { 2388 // (C++ 13.3.2p3): for F to be a viable function, there shall 2389 // exist for each argument an implicit conversion sequence 2390 // (13.3.3.1) that converts that argument to the corresponding 2391 // parameter of F. 2392 QualType ParamType = Proto->getArgType(ArgIdx); 2393 Candidate.Conversions[ArgIdx + 1] 2394 = TryCopyInitialization(Args[ArgIdx], ParamType, 2395 SuppressUserConversions, ForceRValue, 2396 /*InOverloadResolution=*/true); 2397 if (Candidate.Conversions[ArgIdx + 1].ConversionKind 2398 == ImplicitConversionSequence::BadConversion) { 2399 Candidate.Viable = false; 2400 break; 2401 } 2402 } else { 2403 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2404 // argument for which there is no corresponding parameter is 2405 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2406 Candidate.Conversions[ArgIdx + 1].ConversionKind 2407 = ImplicitConversionSequence::EllipsisConversion; 2408 } 2409 } 2410} 2411 2412/// \brief Add a C++ member function template as a candidate to the candidate 2413/// set, using template argument deduction to produce an appropriate member 2414/// function template specialization. 2415void 2416Sema::AddMethodTemplateCandidate(FunctionTemplateDecl *MethodTmpl, 2417 bool HasExplicitTemplateArgs, 2418 const TemplateArgument *ExplicitTemplateArgs, 2419 unsigned NumExplicitTemplateArgs, 2420 Expr *Object, Expr **Args, unsigned NumArgs, 2421 OverloadCandidateSet& CandidateSet, 2422 bool SuppressUserConversions, 2423 bool ForceRValue) { 2424 if (!CandidateSet.isNewCandidate(MethodTmpl)) 2425 return; 2426 2427 // C++ [over.match.funcs]p7: 2428 // In each case where a candidate is a function template, candidate 2429 // function template specializations are generated using template argument 2430 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 2431 // candidate functions in the usual way.113) A given name can refer to one 2432 // or more function templates and also to a set of overloaded non-template 2433 // functions. In such a case, the candidate functions generated from each 2434 // function template are combined with the set of non-template candidate 2435 // functions. 2436 TemplateDeductionInfo Info(Context); 2437 FunctionDecl *Specialization = 0; 2438 if (TemplateDeductionResult Result 2439 = DeduceTemplateArguments(MethodTmpl, HasExplicitTemplateArgs, 2440 ExplicitTemplateArgs, NumExplicitTemplateArgs, 2441 Args, NumArgs, Specialization, Info)) { 2442 // FIXME: Record what happened with template argument deduction, so 2443 // that we can give the user a beautiful diagnostic. 2444 (void)Result; 2445 return; 2446 } 2447 2448 // Add the function template specialization produced by template argument 2449 // deduction as a candidate. 2450 assert(Specialization && "Missing member function template specialization?"); 2451 assert(isa<CXXMethodDecl>(Specialization) && 2452 "Specialization is not a member function?"); 2453 AddMethodCandidate(cast<CXXMethodDecl>(Specialization), Object, Args, NumArgs, 2454 CandidateSet, SuppressUserConversions, ForceRValue); 2455} 2456 2457/// \brief Add a C++ function template specialization as a candidate 2458/// in the candidate set, using template argument deduction to produce 2459/// an appropriate function template specialization. 2460void 2461Sema::AddTemplateOverloadCandidate(FunctionTemplateDecl *FunctionTemplate, 2462 bool HasExplicitTemplateArgs, 2463 const TemplateArgument *ExplicitTemplateArgs, 2464 unsigned NumExplicitTemplateArgs, 2465 Expr **Args, unsigned NumArgs, 2466 OverloadCandidateSet& CandidateSet, 2467 bool SuppressUserConversions, 2468 bool ForceRValue) { 2469 if (!CandidateSet.isNewCandidate(FunctionTemplate)) 2470 return; 2471 2472 // C++ [over.match.funcs]p7: 2473 // In each case where a candidate is a function template, candidate 2474 // function template specializations are generated using template argument 2475 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 2476 // candidate functions in the usual way.113) A given name can refer to one 2477 // or more function templates and also to a set of overloaded non-template 2478 // functions. In such a case, the candidate functions generated from each 2479 // function template are combined with the set of non-template candidate 2480 // functions. 2481 TemplateDeductionInfo Info(Context); 2482 FunctionDecl *Specialization = 0; 2483 if (TemplateDeductionResult Result 2484 = DeduceTemplateArguments(FunctionTemplate, HasExplicitTemplateArgs, 2485 ExplicitTemplateArgs, NumExplicitTemplateArgs, 2486 Args, NumArgs, Specialization, Info)) { 2487 // FIXME: Record what happened with template argument deduction, so 2488 // that we can give the user a beautiful diagnostic. 2489 (void)Result; 2490 return; 2491 } 2492 2493 // Add the function template specialization produced by template argument 2494 // deduction as a candidate. 2495 assert(Specialization && "Missing function template specialization?"); 2496 AddOverloadCandidate(Specialization, Args, NumArgs, CandidateSet, 2497 SuppressUserConversions, ForceRValue); 2498} 2499 2500/// AddConversionCandidate - Add a C++ conversion function as a 2501/// candidate in the candidate set (C++ [over.match.conv], 2502/// C++ [over.match.copy]). From is the expression we're converting from, 2503/// and ToType is the type that we're eventually trying to convert to 2504/// (which may or may not be the same type as the type that the 2505/// conversion function produces). 2506void 2507Sema::AddConversionCandidate(CXXConversionDecl *Conversion, 2508 Expr *From, QualType ToType, 2509 OverloadCandidateSet& CandidateSet) { 2510 assert(!Conversion->getDescribedFunctionTemplate() && 2511 "Conversion function templates use AddTemplateConversionCandidate"); 2512 2513 if (!CandidateSet.isNewCandidate(Conversion)) 2514 return; 2515 2516 // Add this candidate 2517 CandidateSet.push_back(OverloadCandidate()); 2518 OverloadCandidate& Candidate = CandidateSet.back(); 2519 Candidate.Function = Conversion; 2520 Candidate.IsSurrogate = false; 2521 Candidate.IgnoreObjectArgument = false; 2522 Candidate.FinalConversion.setAsIdentityConversion(); 2523 Candidate.FinalConversion.FromTypePtr 2524 = Conversion->getConversionType().getAsOpaquePtr(); 2525 Candidate.FinalConversion.ToTypePtr = ToType.getAsOpaquePtr(); 2526 2527 // Determine the implicit conversion sequence for the implicit 2528 // object parameter. 2529 Candidate.Viable = true; 2530 Candidate.Conversions.resize(1); 2531 Candidate.Conversions[0] = TryObjectArgumentInitialization(From, Conversion); 2532 // Conversion functions to a different type in the base class is visible in 2533 // the derived class. So, a derived to base conversion should not participate 2534 // in overload resolution. 2535 if (Candidate.Conversions[0].Standard.Second == ICK_Derived_To_Base) 2536 Candidate.Conversions[0].Standard.Second = ICK_Identity; 2537 if (Candidate.Conversions[0].ConversionKind 2538 == ImplicitConversionSequence::BadConversion) { 2539 Candidate.Viable = false; 2540 return; 2541 } 2542 2543 // To determine what the conversion from the result of calling the 2544 // conversion function to the type we're eventually trying to 2545 // convert to (ToType), we need to synthesize a call to the 2546 // conversion function and attempt copy initialization from it. This 2547 // makes sure that we get the right semantics with respect to 2548 // lvalues/rvalues and the type. Fortunately, we can allocate this 2549 // call on the stack and we don't need its arguments to be 2550 // well-formed. 2551 DeclRefExpr ConversionRef(Conversion, Conversion->getType(), 2552 SourceLocation()); 2553 ImplicitCastExpr ConversionFn(Context.getPointerType(Conversion->getType()), 2554 CastExpr::CK_Unknown, 2555 &ConversionRef, false); 2556 2557 // Note that it is safe to allocate CallExpr on the stack here because 2558 // there are 0 arguments (i.e., nothing is allocated using ASTContext's 2559 // allocator). 2560 CallExpr Call(Context, &ConversionFn, 0, 0, 2561 Conversion->getConversionType().getNonReferenceType(), 2562 SourceLocation()); 2563 ImplicitConversionSequence ICS = 2564 TryCopyInitialization(&Call, ToType, 2565 /*SuppressUserConversions=*/true, 2566 /*ForceRValue=*/false, 2567 /*InOverloadResolution=*/false); 2568 2569 switch (ICS.ConversionKind) { 2570 case ImplicitConversionSequence::StandardConversion: 2571 Candidate.FinalConversion = ICS.Standard; 2572 break; 2573 2574 case ImplicitConversionSequence::BadConversion: 2575 Candidate.Viable = false; 2576 break; 2577 2578 default: 2579 assert(false && 2580 "Can only end up with a standard conversion sequence or failure"); 2581 } 2582} 2583 2584/// \brief Adds a conversion function template specialization 2585/// candidate to the overload set, using template argument deduction 2586/// to deduce the template arguments of the conversion function 2587/// template from the type that we are converting to (C++ 2588/// [temp.deduct.conv]). 2589void 2590Sema::AddTemplateConversionCandidate(FunctionTemplateDecl *FunctionTemplate, 2591 Expr *From, QualType ToType, 2592 OverloadCandidateSet &CandidateSet) { 2593 assert(isa<CXXConversionDecl>(FunctionTemplate->getTemplatedDecl()) && 2594 "Only conversion function templates permitted here"); 2595 2596 if (!CandidateSet.isNewCandidate(FunctionTemplate)) 2597 return; 2598 2599 TemplateDeductionInfo Info(Context); 2600 CXXConversionDecl *Specialization = 0; 2601 if (TemplateDeductionResult Result 2602 = DeduceTemplateArguments(FunctionTemplate, ToType, 2603 Specialization, Info)) { 2604 // FIXME: Record what happened with template argument deduction, so 2605 // that we can give the user a beautiful diagnostic. 2606 (void)Result; 2607 return; 2608 } 2609 2610 // Add the conversion function template specialization produced by 2611 // template argument deduction as a candidate. 2612 assert(Specialization && "Missing function template specialization?"); 2613 AddConversionCandidate(Specialization, From, ToType, CandidateSet); 2614} 2615 2616/// AddSurrogateCandidate - Adds a "surrogate" candidate function that 2617/// converts the given @c Object to a function pointer via the 2618/// conversion function @c Conversion, and then attempts to call it 2619/// with the given arguments (C++ [over.call.object]p2-4). Proto is 2620/// the type of function that we'll eventually be calling. 2621void Sema::AddSurrogateCandidate(CXXConversionDecl *Conversion, 2622 const FunctionProtoType *Proto, 2623 Expr *Object, Expr **Args, unsigned NumArgs, 2624 OverloadCandidateSet& CandidateSet) { 2625 if (!CandidateSet.isNewCandidate(Conversion)) 2626 return; 2627 2628 CandidateSet.push_back(OverloadCandidate()); 2629 OverloadCandidate& Candidate = CandidateSet.back(); 2630 Candidate.Function = 0; 2631 Candidate.Surrogate = Conversion; 2632 Candidate.Viable = true; 2633 Candidate.IsSurrogate = true; 2634 Candidate.IgnoreObjectArgument = false; 2635 Candidate.Conversions.resize(NumArgs + 1); 2636 2637 // Determine the implicit conversion sequence for the implicit 2638 // object parameter. 2639 ImplicitConversionSequence ObjectInit 2640 = TryObjectArgumentInitialization(Object, Conversion); 2641 if (ObjectInit.ConversionKind == ImplicitConversionSequence::BadConversion) { 2642 Candidate.Viable = false; 2643 return; 2644 } 2645 2646 // The first conversion is actually a user-defined conversion whose 2647 // first conversion is ObjectInit's standard conversion (which is 2648 // effectively a reference binding). Record it as such. 2649 Candidate.Conversions[0].ConversionKind 2650 = ImplicitConversionSequence::UserDefinedConversion; 2651 Candidate.Conversions[0].UserDefined.Before = ObjectInit.Standard; 2652 Candidate.Conversions[0].UserDefined.ConversionFunction = Conversion; 2653 Candidate.Conversions[0].UserDefined.After 2654 = Candidate.Conversions[0].UserDefined.Before; 2655 Candidate.Conversions[0].UserDefined.After.setAsIdentityConversion(); 2656 2657 // Find the 2658 unsigned NumArgsInProto = Proto->getNumArgs(); 2659 2660 // (C++ 13.3.2p2): A candidate function having fewer than m 2661 // parameters is viable only if it has an ellipsis in its parameter 2662 // list (8.3.5). 2663 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 2664 Candidate.Viable = false; 2665 return; 2666 } 2667 2668 // Function types don't have any default arguments, so just check if 2669 // we have enough arguments. 2670 if (NumArgs < NumArgsInProto) { 2671 // Not enough arguments. 2672 Candidate.Viable = false; 2673 return; 2674 } 2675 2676 // Determine the implicit conversion sequences for each of the 2677 // arguments. 2678 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2679 if (ArgIdx < NumArgsInProto) { 2680 // (C++ 13.3.2p3): for F to be a viable function, there shall 2681 // exist for each argument an implicit conversion sequence 2682 // (13.3.3.1) that converts that argument to the corresponding 2683 // parameter of F. 2684 QualType ParamType = Proto->getArgType(ArgIdx); 2685 Candidate.Conversions[ArgIdx + 1] 2686 = TryCopyInitialization(Args[ArgIdx], ParamType, 2687 /*SuppressUserConversions=*/false, 2688 /*ForceRValue=*/false, 2689 /*InOverloadResolution=*/false); 2690 if (Candidate.Conversions[ArgIdx + 1].ConversionKind 2691 == ImplicitConversionSequence::BadConversion) { 2692 Candidate.Viable = false; 2693 break; 2694 } 2695 } else { 2696 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2697 // argument for which there is no corresponding parameter is 2698 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2699 Candidate.Conversions[ArgIdx + 1].ConversionKind 2700 = ImplicitConversionSequence::EllipsisConversion; 2701 } 2702 } 2703} 2704 2705// FIXME: This will eventually be removed, once we've migrated all of the 2706// operator overloading logic over to the scheme used by binary operators, which 2707// works for template instantiation. 2708void Sema::AddOperatorCandidates(OverloadedOperatorKind Op, Scope *S, 2709 SourceLocation OpLoc, 2710 Expr **Args, unsigned NumArgs, 2711 OverloadCandidateSet& CandidateSet, 2712 SourceRange OpRange) { 2713 FunctionSet Functions; 2714 2715 QualType T1 = Args[0]->getType(); 2716 QualType T2; 2717 if (NumArgs > 1) 2718 T2 = Args[1]->getType(); 2719 2720 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 2721 if (S) 2722 LookupOverloadedOperatorName(Op, S, T1, T2, Functions); 2723 ArgumentDependentLookup(OpName, Args, NumArgs, Functions); 2724 AddFunctionCandidates(Functions, Args, NumArgs, CandidateSet); 2725 AddMemberOperatorCandidates(Op, OpLoc, Args, NumArgs, CandidateSet, OpRange); 2726 AddBuiltinOperatorCandidates(Op, Args, NumArgs, CandidateSet); 2727} 2728 2729/// \brief Add overload candidates for overloaded operators that are 2730/// member functions. 2731/// 2732/// Add the overloaded operator candidates that are member functions 2733/// for the operator Op that was used in an operator expression such 2734/// as "x Op y". , Args/NumArgs provides the operator arguments, and 2735/// CandidateSet will store the added overload candidates. (C++ 2736/// [over.match.oper]). 2737void Sema::AddMemberOperatorCandidates(OverloadedOperatorKind Op, 2738 SourceLocation OpLoc, 2739 Expr **Args, unsigned NumArgs, 2740 OverloadCandidateSet& CandidateSet, 2741 SourceRange OpRange) { 2742 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 2743 2744 // C++ [over.match.oper]p3: 2745 // For a unary operator @ with an operand of a type whose 2746 // cv-unqualified version is T1, and for a binary operator @ with 2747 // a left operand of a type whose cv-unqualified version is T1 and 2748 // a right operand of a type whose cv-unqualified version is T2, 2749 // three sets of candidate functions, designated member 2750 // candidates, non-member candidates and built-in candidates, are 2751 // constructed as follows: 2752 QualType T1 = Args[0]->getType(); 2753 QualType T2; 2754 if (NumArgs > 1) 2755 T2 = Args[1]->getType(); 2756 2757 // -- If T1 is a class type, the set of member candidates is the 2758 // result of the qualified lookup of T1::operator@ 2759 // (13.3.1.1.1); otherwise, the set of member candidates is 2760 // empty. 2761 if (const RecordType *T1Rec = T1->getAs<RecordType>()) { 2762 // Complete the type if it can be completed. Otherwise, we're done. 2763 if (RequireCompleteType(OpLoc, T1, PDiag())) 2764 return; 2765 2766 LookupResult Operators; 2767 LookupQualifiedName(Operators, T1Rec->getDecl(), OpName, 2768 LookupOrdinaryName, false); 2769 for (LookupResult::iterator Oper = Operators.begin(), 2770 OperEnd = Operators.end(); 2771 Oper != OperEnd; 2772 ++Oper) { 2773 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(*Oper)) { 2774 AddMethodCandidate(Method, Args[0], Args+1, NumArgs - 1, CandidateSet, 2775 /*SuppressUserConversions=*/false); 2776 continue; 2777 } 2778 2779 assert(isa<FunctionTemplateDecl>(*Oper) && 2780 isa<CXXMethodDecl>(cast<FunctionTemplateDecl>(*Oper) 2781 ->getTemplatedDecl()) && 2782 "Expected a member function template"); 2783 AddMethodTemplateCandidate(cast<FunctionTemplateDecl>(*Oper), false, 0, 0, 2784 Args[0], Args+1, NumArgs - 1, CandidateSet, 2785 /*SuppressUserConversions=*/false); 2786 } 2787 } 2788} 2789 2790/// AddBuiltinCandidate - Add a candidate for a built-in 2791/// operator. ResultTy and ParamTys are the result and parameter types 2792/// of the built-in candidate, respectively. Args and NumArgs are the 2793/// arguments being passed to the candidate. IsAssignmentOperator 2794/// should be true when this built-in candidate is an assignment 2795/// operator. NumContextualBoolArguments is the number of arguments 2796/// (at the beginning of the argument list) that will be contextually 2797/// converted to bool. 2798void Sema::AddBuiltinCandidate(QualType ResultTy, QualType *ParamTys, 2799 Expr **Args, unsigned NumArgs, 2800 OverloadCandidateSet& CandidateSet, 2801 bool IsAssignmentOperator, 2802 unsigned NumContextualBoolArguments) { 2803 // Add this candidate 2804 CandidateSet.push_back(OverloadCandidate()); 2805 OverloadCandidate& Candidate = CandidateSet.back(); 2806 Candidate.Function = 0; 2807 Candidate.IsSurrogate = false; 2808 Candidate.IgnoreObjectArgument = false; 2809 Candidate.BuiltinTypes.ResultTy = ResultTy; 2810 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 2811 Candidate.BuiltinTypes.ParamTypes[ArgIdx] = ParamTys[ArgIdx]; 2812 2813 // Determine the implicit conversion sequences for each of the 2814 // arguments. 2815 Candidate.Viable = true; 2816 Candidate.Conversions.resize(NumArgs); 2817 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2818 // C++ [over.match.oper]p4: 2819 // For the built-in assignment operators, conversions of the 2820 // left operand are restricted as follows: 2821 // -- no temporaries are introduced to hold the left operand, and 2822 // -- no user-defined conversions are applied to the left 2823 // operand to achieve a type match with the left-most 2824 // parameter of a built-in candidate. 2825 // 2826 // We block these conversions by turning off user-defined 2827 // conversions, since that is the only way that initialization of 2828 // a reference to a non-class type can occur from something that 2829 // is not of the same type. 2830 if (ArgIdx < NumContextualBoolArguments) { 2831 assert(ParamTys[ArgIdx] == Context.BoolTy && 2832 "Contextual conversion to bool requires bool type"); 2833 Candidate.Conversions[ArgIdx] = TryContextuallyConvertToBool(Args[ArgIdx]); 2834 } else { 2835 Candidate.Conversions[ArgIdx] 2836 = TryCopyInitialization(Args[ArgIdx], ParamTys[ArgIdx], 2837 ArgIdx == 0 && IsAssignmentOperator, 2838 /*ForceRValue=*/false, 2839 /*InOverloadResolution=*/false); 2840 } 2841 if (Candidate.Conversions[ArgIdx].ConversionKind 2842 == ImplicitConversionSequence::BadConversion) { 2843 Candidate.Viable = false; 2844 break; 2845 } 2846 } 2847} 2848 2849/// BuiltinCandidateTypeSet - A set of types that will be used for the 2850/// candidate operator functions for built-in operators (C++ 2851/// [over.built]). The types are separated into pointer types and 2852/// enumeration types. 2853class BuiltinCandidateTypeSet { 2854 /// TypeSet - A set of types. 2855 typedef llvm::SmallPtrSet<QualType, 8> TypeSet; 2856 2857 /// PointerTypes - The set of pointer types that will be used in the 2858 /// built-in candidates. 2859 TypeSet PointerTypes; 2860 2861 /// MemberPointerTypes - The set of member pointer types that will be 2862 /// used in the built-in candidates. 2863 TypeSet MemberPointerTypes; 2864 2865 /// EnumerationTypes - The set of enumeration types that will be 2866 /// used in the built-in candidates. 2867 TypeSet EnumerationTypes; 2868 2869 /// Sema - The semantic analysis instance where we are building the 2870 /// candidate type set. 2871 Sema &SemaRef; 2872 2873 /// Context - The AST context in which we will build the type sets. 2874 ASTContext &Context; 2875 2876 bool AddPointerWithMoreQualifiedTypeVariants(QualType Ty); 2877 bool AddMemberPointerWithMoreQualifiedTypeVariants(QualType Ty); 2878 2879public: 2880 /// iterator - Iterates through the types that are part of the set. 2881 typedef TypeSet::iterator iterator; 2882 2883 BuiltinCandidateTypeSet(Sema &SemaRef) 2884 : SemaRef(SemaRef), Context(SemaRef.Context) { } 2885 2886 void AddTypesConvertedFrom(QualType Ty, bool AllowUserConversions, 2887 bool AllowExplicitConversions); 2888 2889 /// pointer_begin - First pointer type found; 2890 iterator pointer_begin() { return PointerTypes.begin(); } 2891 2892 /// pointer_end - Past the last pointer type found; 2893 iterator pointer_end() { return PointerTypes.end(); } 2894 2895 /// member_pointer_begin - First member pointer type found; 2896 iterator member_pointer_begin() { return MemberPointerTypes.begin(); } 2897 2898 /// member_pointer_end - Past the last member pointer type found; 2899 iterator member_pointer_end() { return MemberPointerTypes.end(); } 2900 2901 /// enumeration_begin - First enumeration type found; 2902 iterator enumeration_begin() { return EnumerationTypes.begin(); } 2903 2904 /// enumeration_end - Past the last enumeration type found; 2905 iterator enumeration_end() { return EnumerationTypes.end(); } 2906}; 2907 2908/// AddPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty to 2909/// the set of pointer types along with any more-qualified variants of 2910/// that type. For example, if @p Ty is "int const *", this routine 2911/// will add "int const *", "int const volatile *", "int const 2912/// restrict *", and "int const volatile restrict *" to the set of 2913/// pointer types. Returns true if the add of @p Ty itself succeeded, 2914/// false otherwise. 2915/// 2916/// FIXME: what to do about extended qualifiers? 2917bool 2918BuiltinCandidateTypeSet::AddPointerWithMoreQualifiedTypeVariants(QualType Ty) { 2919 2920 // Insert this type. 2921 if (!PointerTypes.insert(Ty)) 2922 return false; 2923 2924 const PointerType *PointerTy = Ty->getAs<PointerType>(); 2925 assert(PointerTy && "type was not a pointer type!"); 2926 2927 QualType PointeeTy = PointerTy->getPointeeType(); 2928 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 2929 2930 // Iterate through all strict supersets of BaseCVR. 2931 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 2932 if ((CVR | BaseCVR) != CVR) continue; 2933 2934 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 2935 PointerTypes.insert(Context.getPointerType(QPointeeTy)); 2936 } 2937 2938 return true; 2939} 2940 2941/// AddMemberPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty 2942/// to the set of pointer types along with any more-qualified variants of 2943/// that type. For example, if @p Ty is "int const *", this routine 2944/// will add "int const *", "int const volatile *", "int const 2945/// restrict *", and "int const volatile restrict *" to the set of 2946/// pointer types. Returns true if the add of @p Ty itself succeeded, 2947/// false otherwise. 2948/// 2949/// FIXME: what to do about extended qualifiers? 2950bool 2951BuiltinCandidateTypeSet::AddMemberPointerWithMoreQualifiedTypeVariants( 2952 QualType Ty) { 2953 // Insert this type. 2954 if (!MemberPointerTypes.insert(Ty)) 2955 return false; 2956 2957 const MemberPointerType *PointerTy = Ty->getAs<MemberPointerType>(); 2958 assert(PointerTy && "type was not a member pointer type!"); 2959 2960 QualType PointeeTy = PointerTy->getPointeeType(); 2961 const Type *ClassTy = PointerTy->getClass(); 2962 2963 // Iterate through all strict supersets of the pointee type's CVR 2964 // qualifiers. 2965 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 2966 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 2967 if ((CVR | BaseCVR) != CVR) continue; 2968 2969 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 2970 MemberPointerTypes.insert(Context.getMemberPointerType(QPointeeTy, ClassTy)); 2971 } 2972 2973 return true; 2974} 2975 2976/// AddTypesConvertedFrom - Add each of the types to which the type @p 2977/// Ty can be implicit converted to the given set of @p Types. We're 2978/// primarily interested in pointer types and enumeration types. We also 2979/// take member pointer types, for the conditional operator. 2980/// AllowUserConversions is true if we should look at the conversion 2981/// functions of a class type, and AllowExplicitConversions if we 2982/// should also include the explicit conversion functions of a class 2983/// type. 2984void 2985BuiltinCandidateTypeSet::AddTypesConvertedFrom(QualType Ty, 2986 bool AllowUserConversions, 2987 bool AllowExplicitConversions) { 2988 // Only deal with canonical types. 2989 Ty = Context.getCanonicalType(Ty); 2990 2991 // Look through reference types; they aren't part of the type of an 2992 // expression for the purposes of conversions. 2993 if (const ReferenceType *RefTy = Ty->getAs<ReferenceType>()) 2994 Ty = RefTy->getPointeeType(); 2995 2996 // We don't care about qualifiers on the type. 2997 Ty = Ty.getUnqualifiedType(); 2998 2999 if (const PointerType *PointerTy = Ty->getAs<PointerType>()) { 3000 QualType PointeeTy = PointerTy->getPointeeType(); 3001 3002 // Insert our type, and its more-qualified variants, into the set 3003 // of types. 3004 if (!AddPointerWithMoreQualifiedTypeVariants(Ty)) 3005 return; 3006 3007 // Add 'cv void*' to our set of types. 3008 if (!Ty->isVoidType()) { 3009 QualType QualVoid 3010 = Context.getCVRQualifiedType(Context.VoidTy, 3011 PointeeTy.getCVRQualifiers()); 3012 AddPointerWithMoreQualifiedTypeVariants(Context.getPointerType(QualVoid)); 3013 } 3014 3015 // If this is a pointer to a class type, add pointers to its bases 3016 // (with the same level of cv-qualification as the original 3017 // derived class, of course). 3018 if (const RecordType *PointeeRec = PointeeTy->getAs<RecordType>()) { 3019 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(PointeeRec->getDecl()); 3020 for (CXXRecordDecl::base_class_iterator Base = ClassDecl->bases_begin(); 3021 Base != ClassDecl->bases_end(); ++Base) { 3022 QualType BaseTy = Context.getCanonicalType(Base->getType()); 3023 BaseTy = Context.getCVRQualifiedType(BaseTy.getUnqualifiedType(), 3024 PointeeTy.getCVRQualifiers()); 3025 3026 // Add the pointer type, recursively, so that we get all of 3027 // the indirect base classes, too. 3028 AddTypesConvertedFrom(Context.getPointerType(BaseTy), false, false); 3029 } 3030 } 3031 } else if (Ty->isMemberPointerType()) { 3032 // Member pointers are far easier, since the pointee can't be converted. 3033 if (!AddMemberPointerWithMoreQualifiedTypeVariants(Ty)) 3034 return; 3035 } else if (Ty->isEnumeralType()) { 3036 EnumerationTypes.insert(Ty); 3037 } else if (AllowUserConversions) { 3038 if (const RecordType *TyRec = Ty->getAs<RecordType>()) { 3039 if (SemaRef.RequireCompleteType(SourceLocation(), Ty, 0)) { 3040 // No conversion functions in incomplete types. 3041 return; 3042 } 3043 3044 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 3045 OverloadedFunctionDecl *Conversions 3046 = ClassDecl->getVisibleConversionFunctions(); 3047 for (OverloadedFunctionDecl::function_iterator Func 3048 = Conversions->function_begin(); 3049 Func != Conversions->function_end(); ++Func) { 3050 CXXConversionDecl *Conv; 3051 FunctionTemplateDecl *ConvTemplate; 3052 GetFunctionAndTemplate(*Func, Conv, ConvTemplate); 3053 3054 // Skip conversion function templates; they don't tell us anything 3055 // about which builtin types we can convert to. 3056 if (ConvTemplate) 3057 continue; 3058 3059 if (AllowExplicitConversions || !Conv->isExplicit()) 3060 AddTypesConvertedFrom(Conv->getConversionType(), false, false); 3061 } 3062 } 3063 } 3064} 3065 3066/// \brief Helper function for AddBuiltinOperatorCandidates() that adds 3067/// the volatile- and non-volatile-qualified assignment operators for the 3068/// given type to the candidate set. 3069static void AddBuiltinAssignmentOperatorCandidates(Sema &S, 3070 QualType T, 3071 Expr **Args, 3072 unsigned NumArgs, 3073 OverloadCandidateSet &CandidateSet) { 3074 QualType ParamTypes[2]; 3075 3076 // T& operator=(T&, T) 3077 ParamTypes[0] = S.Context.getLValueReferenceType(T); 3078 ParamTypes[1] = T; 3079 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3080 /*IsAssignmentOperator=*/true); 3081 3082 if (!S.Context.getCanonicalType(T).isVolatileQualified()) { 3083 // volatile T& operator=(volatile T&, T) 3084 ParamTypes[0] 3085 = S.Context.getLValueReferenceType(S.Context.getVolatileType(T)); 3086 ParamTypes[1] = T; 3087 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3088 /*IsAssignmentOperator=*/true); 3089 } 3090} 3091 3092/// AddBuiltinOperatorCandidates - Add the appropriate built-in 3093/// operator overloads to the candidate set (C++ [over.built]), based 3094/// on the operator @p Op and the arguments given. For example, if the 3095/// operator is a binary '+', this routine might add "int 3096/// operator+(int, int)" to cover integer addition. 3097void 3098Sema::AddBuiltinOperatorCandidates(OverloadedOperatorKind Op, 3099 Expr **Args, unsigned NumArgs, 3100 OverloadCandidateSet& CandidateSet) { 3101 // The set of "promoted arithmetic types", which are the arithmetic 3102 // types are that preserved by promotion (C++ [over.built]p2). Note 3103 // that the first few of these types are the promoted integral 3104 // types; these types need to be first. 3105 // FIXME: What about complex? 3106 const unsigned FirstIntegralType = 0; 3107 const unsigned LastIntegralType = 13; 3108 const unsigned FirstPromotedIntegralType = 7, 3109 LastPromotedIntegralType = 13; 3110 const unsigned FirstPromotedArithmeticType = 7, 3111 LastPromotedArithmeticType = 16; 3112 const unsigned NumArithmeticTypes = 16; 3113 QualType ArithmeticTypes[NumArithmeticTypes] = { 3114 Context.BoolTy, Context.CharTy, Context.WCharTy, 3115// FIXME: Context.Char16Ty, Context.Char32Ty, 3116 Context.SignedCharTy, Context.ShortTy, 3117 Context.UnsignedCharTy, Context.UnsignedShortTy, 3118 Context.IntTy, Context.LongTy, Context.LongLongTy, 3119 Context.UnsignedIntTy, Context.UnsignedLongTy, Context.UnsignedLongLongTy, 3120 Context.FloatTy, Context.DoubleTy, Context.LongDoubleTy 3121 }; 3122 3123 // Find all of the types that the arguments can convert to, but only 3124 // if the operator we're looking at has built-in operator candidates 3125 // that make use of these types. 3126 BuiltinCandidateTypeSet CandidateTypes(*this); 3127 if (Op == OO_Less || Op == OO_Greater || Op == OO_LessEqual || 3128 Op == OO_GreaterEqual || Op == OO_EqualEqual || Op == OO_ExclaimEqual || 3129 Op == OO_Plus || (Op == OO_Minus && NumArgs == 2) || Op == OO_Equal || 3130 Op == OO_PlusEqual || Op == OO_MinusEqual || Op == OO_Subscript || 3131 Op == OO_ArrowStar || Op == OO_PlusPlus || Op == OO_MinusMinus || 3132 (Op == OO_Star && NumArgs == 1) || Op == OO_Conditional) { 3133 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 3134 CandidateTypes.AddTypesConvertedFrom(Args[ArgIdx]->getType(), 3135 true, 3136 (Op == OO_Exclaim || 3137 Op == OO_AmpAmp || 3138 Op == OO_PipePipe)); 3139 } 3140 3141 bool isComparison = false; 3142 switch (Op) { 3143 case OO_None: 3144 case NUM_OVERLOADED_OPERATORS: 3145 assert(false && "Expected an overloaded operator"); 3146 break; 3147 3148 case OO_Star: // '*' is either unary or binary 3149 if (NumArgs == 1) 3150 goto UnaryStar; 3151 else 3152 goto BinaryStar; 3153 break; 3154 3155 case OO_Plus: // '+' is either unary or binary 3156 if (NumArgs == 1) 3157 goto UnaryPlus; 3158 else 3159 goto BinaryPlus; 3160 break; 3161 3162 case OO_Minus: // '-' is either unary or binary 3163 if (NumArgs == 1) 3164 goto UnaryMinus; 3165 else 3166 goto BinaryMinus; 3167 break; 3168 3169 case OO_Amp: // '&' is either unary or binary 3170 if (NumArgs == 1) 3171 goto UnaryAmp; 3172 else 3173 goto BinaryAmp; 3174 3175 case OO_PlusPlus: 3176 case OO_MinusMinus: 3177 // C++ [over.built]p3: 3178 // 3179 // For every pair (T, VQ), where T is an arithmetic type, and VQ 3180 // is either volatile or empty, there exist candidate operator 3181 // functions of the form 3182 // 3183 // VQ T& operator++(VQ T&); 3184 // T operator++(VQ T&, int); 3185 // 3186 // C++ [over.built]p4: 3187 // 3188 // For every pair (T, VQ), where T is an arithmetic type other 3189 // than bool, and VQ is either volatile or empty, there exist 3190 // candidate operator functions of the form 3191 // 3192 // VQ T& operator--(VQ T&); 3193 // T operator--(VQ T&, int); 3194 for (unsigned Arith = (Op == OO_PlusPlus? 0 : 1); 3195 Arith < NumArithmeticTypes; ++Arith) { 3196 QualType ArithTy = ArithmeticTypes[Arith]; 3197 QualType ParamTypes[2] 3198 = { Context.getLValueReferenceType(ArithTy), Context.IntTy }; 3199 3200 // Non-volatile version. 3201 if (NumArgs == 1) 3202 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3203 else 3204 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 3205 3206 // Volatile version 3207 ParamTypes[0] 3208 = Context.getLValueReferenceType(Context.getVolatileType(ArithTy)); 3209 if (NumArgs == 1) 3210 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3211 else 3212 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 3213 } 3214 3215 // C++ [over.built]p5: 3216 // 3217 // For every pair (T, VQ), where T is a cv-qualified or 3218 // cv-unqualified object type, and VQ is either volatile or 3219 // empty, there exist candidate operator functions of the form 3220 // 3221 // T*VQ& operator++(T*VQ&); 3222 // T*VQ& operator--(T*VQ&); 3223 // T* operator++(T*VQ&, int); 3224 // T* operator--(T*VQ&, int); 3225 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3226 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3227 // Skip pointer types that aren't pointers to object types. 3228 if (!(*Ptr)->getAs<PointerType>()->getPointeeType()->isObjectType()) 3229 continue; 3230 3231 QualType ParamTypes[2] = { 3232 Context.getLValueReferenceType(*Ptr), Context.IntTy 3233 }; 3234 3235 // Without volatile 3236 if (NumArgs == 1) 3237 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3238 else 3239 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3240 3241 if (!Context.getCanonicalType(*Ptr).isVolatileQualified()) { 3242 // With volatile 3243 ParamTypes[0] 3244 = Context.getLValueReferenceType(Context.getVolatileType(*Ptr)); 3245 if (NumArgs == 1) 3246 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3247 else 3248 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3249 } 3250 } 3251 break; 3252 3253 UnaryStar: 3254 // C++ [over.built]p6: 3255 // For every cv-qualified or cv-unqualified object type T, there 3256 // exist candidate operator functions of the form 3257 // 3258 // T& operator*(T*); 3259 // 3260 // C++ [over.built]p7: 3261 // For every function type T, there exist candidate operator 3262 // functions of the form 3263 // T& operator*(T*); 3264 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3265 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3266 QualType ParamTy = *Ptr; 3267 QualType PointeeTy = ParamTy->getAs<PointerType>()->getPointeeType(); 3268 AddBuiltinCandidate(Context.getLValueReferenceType(PointeeTy), 3269 &ParamTy, Args, 1, CandidateSet); 3270 } 3271 break; 3272 3273 UnaryPlus: 3274 // C++ [over.built]p8: 3275 // For every type T, there exist candidate operator functions of 3276 // the form 3277 // 3278 // T* operator+(T*); 3279 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3280 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3281 QualType ParamTy = *Ptr; 3282 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet); 3283 } 3284 3285 // Fall through 3286 3287 UnaryMinus: 3288 // C++ [over.built]p9: 3289 // For every promoted arithmetic type T, there exist candidate 3290 // operator functions of the form 3291 // 3292 // T operator+(T); 3293 // T operator-(T); 3294 for (unsigned Arith = FirstPromotedArithmeticType; 3295 Arith < LastPromotedArithmeticType; ++Arith) { 3296 QualType ArithTy = ArithmeticTypes[Arith]; 3297 AddBuiltinCandidate(ArithTy, &ArithTy, Args, 1, CandidateSet); 3298 } 3299 break; 3300 3301 case OO_Tilde: 3302 // C++ [over.built]p10: 3303 // For every promoted integral type T, there exist candidate 3304 // operator functions of the form 3305 // 3306 // T operator~(T); 3307 for (unsigned Int = FirstPromotedIntegralType; 3308 Int < LastPromotedIntegralType; ++Int) { 3309 QualType IntTy = ArithmeticTypes[Int]; 3310 AddBuiltinCandidate(IntTy, &IntTy, Args, 1, CandidateSet); 3311 } 3312 break; 3313 3314 case OO_New: 3315 case OO_Delete: 3316 case OO_Array_New: 3317 case OO_Array_Delete: 3318 case OO_Call: 3319 assert(false && "Special operators don't use AddBuiltinOperatorCandidates"); 3320 break; 3321 3322 case OO_Comma: 3323 UnaryAmp: 3324 case OO_Arrow: 3325 // C++ [over.match.oper]p3: 3326 // -- For the operator ',', the unary operator '&', or the 3327 // operator '->', the built-in candidates set is empty. 3328 break; 3329 3330 case OO_EqualEqual: 3331 case OO_ExclaimEqual: 3332 // C++ [over.match.oper]p16: 3333 // For every pointer to member type T, there exist candidate operator 3334 // functions of the form 3335 // 3336 // bool operator==(T,T); 3337 // bool operator!=(T,T); 3338 for (BuiltinCandidateTypeSet::iterator 3339 MemPtr = CandidateTypes.member_pointer_begin(), 3340 MemPtrEnd = CandidateTypes.member_pointer_end(); 3341 MemPtr != MemPtrEnd; 3342 ++MemPtr) { 3343 QualType ParamTypes[2] = { *MemPtr, *MemPtr }; 3344 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 3345 } 3346 3347 // Fall through 3348 3349 case OO_Less: 3350 case OO_Greater: 3351 case OO_LessEqual: 3352 case OO_GreaterEqual: 3353 // C++ [over.built]p15: 3354 // 3355 // For every pointer or enumeration type T, there exist 3356 // candidate operator functions of the form 3357 // 3358 // bool operator<(T, T); 3359 // bool operator>(T, T); 3360 // bool operator<=(T, T); 3361 // bool operator>=(T, T); 3362 // bool operator==(T, T); 3363 // bool operator!=(T, T); 3364 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3365 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3366 QualType ParamTypes[2] = { *Ptr, *Ptr }; 3367 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 3368 } 3369 for (BuiltinCandidateTypeSet::iterator Enum 3370 = CandidateTypes.enumeration_begin(); 3371 Enum != CandidateTypes.enumeration_end(); ++Enum) { 3372 QualType ParamTypes[2] = { *Enum, *Enum }; 3373 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 3374 } 3375 3376 // Fall through. 3377 isComparison = true; 3378 3379 BinaryPlus: 3380 BinaryMinus: 3381 if (!isComparison) { 3382 // We didn't fall through, so we must have OO_Plus or OO_Minus. 3383 3384 // C++ [over.built]p13: 3385 // 3386 // For every cv-qualified or cv-unqualified object type T 3387 // there exist candidate operator functions of the form 3388 // 3389 // T* operator+(T*, ptrdiff_t); 3390 // T& operator[](T*, ptrdiff_t); [BELOW] 3391 // T* operator-(T*, ptrdiff_t); 3392 // T* operator+(ptrdiff_t, T*); 3393 // T& operator[](ptrdiff_t, T*); [BELOW] 3394 // 3395 // C++ [over.built]p14: 3396 // 3397 // For every T, where T is a pointer to object type, there 3398 // exist candidate operator functions of the form 3399 // 3400 // ptrdiff_t operator-(T, T); 3401 for (BuiltinCandidateTypeSet::iterator Ptr 3402 = CandidateTypes.pointer_begin(); 3403 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3404 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 3405 3406 // operator+(T*, ptrdiff_t) or operator-(T*, ptrdiff_t) 3407 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3408 3409 if (Op == OO_Plus) { 3410 // T* operator+(ptrdiff_t, T*); 3411 ParamTypes[0] = ParamTypes[1]; 3412 ParamTypes[1] = *Ptr; 3413 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3414 } else { 3415 // ptrdiff_t operator-(T, T); 3416 ParamTypes[1] = *Ptr; 3417 AddBuiltinCandidate(Context.getPointerDiffType(), ParamTypes, 3418 Args, 2, CandidateSet); 3419 } 3420 } 3421 } 3422 // Fall through 3423 3424 case OO_Slash: 3425 BinaryStar: 3426 Conditional: 3427 // C++ [over.built]p12: 3428 // 3429 // For every pair of promoted arithmetic types L and R, there 3430 // exist candidate operator functions of the form 3431 // 3432 // LR operator*(L, R); 3433 // LR operator/(L, R); 3434 // LR operator+(L, R); 3435 // LR operator-(L, R); 3436 // bool operator<(L, R); 3437 // bool operator>(L, R); 3438 // bool operator<=(L, R); 3439 // bool operator>=(L, R); 3440 // bool operator==(L, R); 3441 // bool operator!=(L, R); 3442 // 3443 // where LR is the result of the usual arithmetic conversions 3444 // between types L and R. 3445 // 3446 // C++ [over.built]p24: 3447 // 3448 // For every pair of promoted arithmetic types L and R, there exist 3449 // candidate operator functions of the form 3450 // 3451 // LR operator?(bool, L, R); 3452 // 3453 // where LR is the result of the usual arithmetic conversions 3454 // between types L and R. 3455 // Our candidates ignore the first parameter. 3456 for (unsigned Left = FirstPromotedArithmeticType; 3457 Left < LastPromotedArithmeticType; ++Left) { 3458 for (unsigned Right = FirstPromotedArithmeticType; 3459 Right < LastPromotedArithmeticType; ++Right) { 3460 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 3461 QualType Result 3462 = isComparison 3463 ? Context.BoolTy 3464 : Context.UsualArithmeticConversionsType(LandR[0], LandR[1]); 3465 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 3466 } 3467 } 3468 break; 3469 3470 case OO_Percent: 3471 BinaryAmp: 3472 case OO_Caret: 3473 case OO_Pipe: 3474 case OO_LessLess: 3475 case OO_GreaterGreater: 3476 // C++ [over.built]p17: 3477 // 3478 // For every pair of promoted integral types L and R, there 3479 // exist candidate operator functions of the form 3480 // 3481 // LR operator%(L, R); 3482 // LR operator&(L, R); 3483 // LR operator^(L, R); 3484 // LR operator|(L, R); 3485 // L operator<<(L, R); 3486 // L operator>>(L, R); 3487 // 3488 // where LR is the result of the usual arithmetic conversions 3489 // between types L and R. 3490 for (unsigned Left = FirstPromotedIntegralType; 3491 Left < LastPromotedIntegralType; ++Left) { 3492 for (unsigned Right = FirstPromotedIntegralType; 3493 Right < LastPromotedIntegralType; ++Right) { 3494 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 3495 QualType Result = (Op == OO_LessLess || Op == OO_GreaterGreater) 3496 ? LandR[0] 3497 : Context.UsualArithmeticConversionsType(LandR[0], LandR[1]); 3498 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 3499 } 3500 } 3501 break; 3502 3503 case OO_Equal: 3504 // C++ [over.built]p20: 3505 // 3506 // For every pair (T, VQ), where T is an enumeration or 3507 // pointer to member type and VQ is either volatile or 3508 // empty, there exist candidate operator functions of the form 3509 // 3510 // VQ T& operator=(VQ T&, T); 3511 for (BuiltinCandidateTypeSet::iterator 3512 Enum = CandidateTypes.enumeration_begin(), 3513 EnumEnd = CandidateTypes.enumeration_end(); 3514 Enum != EnumEnd; ++Enum) 3515 AddBuiltinAssignmentOperatorCandidates(*this, *Enum, Args, 2, 3516 CandidateSet); 3517 for (BuiltinCandidateTypeSet::iterator 3518 MemPtr = CandidateTypes.member_pointer_begin(), 3519 MemPtrEnd = CandidateTypes.member_pointer_end(); 3520 MemPtr != MemPtrEnd; ++MemPtr) 3521 AddBuiltinAssignmentOperatorCandidates(*this, *MemPtr, Args, 2, 3522 CandidateSet); 3523 // Fall through. 3524 3525 case OO_PlusEqual: 3526 case OO_MinusEqual: 3527 // C++ [over.built]p19: 3528 // 3529 // For every pair (T, VQ), where T is any type and VQ is either 3530 // volatile or empty, there exist candidate operator functions 3531 // of the form 3532 // 3533 // T*VQ& operator=(T*VQ&, T*); 3534 // 3535 // C++ [over.built]p21: 3536 // 3537 // For every pair (T, VQ), where T is a cv-qualified or 3538 // cv-unqualified object type and VQ is either volatile or 3539 // empty, there exist candidate operator functions of the form 3540 // 3541 // T*VQ& operator+=(T*VQ&, ptrdiff_t); 3542 // T*VQ& operator-=(T*VQ&, ptrdiff_t); 3543 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3544 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3545 QualType ParamTypes[2]; 3546 ParamTypes[1] = (Op == OO_Equal)? *Ptr : Context.getPointerDiffType(); 3547 3548 // non-volatile version 3549 ParamTypes[0] = Context.getLValueReferenceType(*Ptr); 3550 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3551 /*IsAssigmentOperator=*/Op == OO_Equal); 3552 3553 if (!Context.getCanonicalType(*Ptr).isVolatileQualified()) { 3554 // volatile version 3555 ParamTypes[0] 3556 = Context.getLValueReferenceType(Context.getVolatileType(*Ptr)); 3557 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3558 /*IsAssigmentOperator=*/Op == OO_Equal); 3559 } 3560 } 3561 // Fall through. 3562 3563 case OO_StarEqual: 3564 case OO_SlashEqual: 3565 // C++ [over.built]p18: 3566 // 3567 // For every triple (L, VQ, R), where L is an arithmetic type, 3568 // VQ is either volatile or empty, and R is a promoted 3569 // arithmetic type, there exist candidate operator functions of 3570 // the form 3571 // 3572 // VQ L& operator=(VQ L&, R); 3573 // VQ L& operator*=(VQ L&, R); 3574 // VQ L& operator/=(VQ L&, R); 3575 // VQ L& operator+=(VQ L&, R); 3576 // VQ L& operator-=(VQ L&, R); 3577 for (unsigned Left = 0; Left < NumArithmeticTypes; ++Left) { 3578 for (unsigned Right = FirstPromotedArithmeticType; 3579 Right < LastPromotedArithmeticType; ++Right) { 3580 QualType ParamTypes[2]; 3581 ParamTypes[1] = ArithmeticTypes[Right]; 3582 3583 // Add this built-in operator as a candidate (VQ is empty). 3584 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 3585 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3586 /*IsAssigmentOperator=*/Op == OO_Equal); 3587 3588 // Add this built-in operator as a candidate (VQ is 'volatile'). 3589 ParamTypes[0] = Context.getVolatileType(ArithmeticTypes[Left]); 3590 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 3591 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3592 /*IsAssigmentOperator=*/Op == OO_Equal); 3593 } 3594 } 3595 break; 3596 3597 case OO_PercentEqual: 3598 case OO_LessLessEqual: 3599 case OO_GreaterGreaterEqual: 3600 case OO_AmpEqual: 3601 case OO_CaretEqual: 3602 case OO_PipeEqual: 3603 // C++ [over.built]p22: 3604 // 3605 // For every triple (L, VQ, R), where L is an integral type, VQ 3606 // is either volatile or empty, and R is a promoted integral 3607 // type, there exist candidate operator functions of the form 3608 // 3609 // VQ L& operator%=(VQ L&, R); 3610 // VQ L& operator<<=(VQ L&, R); 3611 // VQ L& operator>>=(VQ L&, R); 3612 // VQ L& operator&=(VQ L&, R); 3613 // VQ L& operator^=(VQ L&, R); 3614 // VQ L& operator|=(VQ L&, R); 3615 for (unsigned Left = FirstIntegralType; Left < LastIntegralType; ++Left) { 3616 for (unsigned Right = FirstPromotedIntegralType; 3617 Right < LastPromotedIntegralType; ++Right) { 3618 QualType ParamTypes[2]; 3619 ParamTypes[1] = ArithmeticTypes[Right]; 3620 3621 // Add this built-in operator as a candidate (VQ is empty). 3622 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 3623 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 3624 3625 // Add this built-in operator as a candidate (VQ is 'volatile'). 3626 ParamTypes[0] = ArithmeticTypes[Left]; 3627 ParamTypes[0] = Context.getVolatileType(ParamTypes[0]); 3628 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 3629 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 3630 } 3631 } 3632 break; 3633 3634 case OO_Exclaim: { 3635 // C++ [over.operator]p23: 3636 // 3637 // There also exist candidate operator functions of the form 3638 // 3639 // bool operator!(bool); 3640 // bool operator&&(bool, bool); [BELOW] 3641 // bool operator||(bool, bool); [BELOW] 3642 QualType ParamTy = Context.BoolTy; 3643 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet, 3644 /*IsAssignmentOperator=*/false, 3645 /*NumContextualBoolArguments=*/1); 3646 break; 3647 } 3648 3649 case OO_AmpAmp: 3650 case OO_PipePipe: { 3651 // C++ [over.operator]p23: 3652 // 3653 // There also exist candidate operator functions of the form 3654 // 3655 // bool operator!(bool); [ABOVE] 3656 // bool operator&&(bool, bool); 3657 // bool operator||(bool, bool); 3658 QualType ParamTypes[2] = { Context.BoolTy, Context.BoolTy }; 3659 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet, 3660 /*IsAssignmentOperator=*/false, 3661 /*NumContextualBoolArguments=*/2); 3662 break; 3663 } 3664 3665 case OO_Subscript: 3666 // C++ [over.built]p13: 3667 // 3668 // For every cv-qualified or cv-unqualified object type T there 3669 // exist candidate operator functions of the form 3670 // 3671 // T* operator+(T*, ptrdiff_t); [ABOVE] 3672 // T& operator[](T*, ptrdiff_t); 3673 // T* operator-(T*, ptrdiff_t); [ABOVE] 3674 // T* operator+(ptrdiff_t, T*); [ABOVE] 3675 // T& operator[](ptrdiff_t, T*); 3676 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3677 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3678 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 3679 QualType PointeeType = (*Ptr)->getAs<PointerType>()->getPointeeType(); 3680 QualType ResultTy = Context.getLValueReferenceType(PointeeType); 3681 3682 // T& operator[](T*, ptrdiff_t) 3683 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 3684 3685 // T& operator[](ptrdiff_t, T*); 3686 ParamTypes[0] = ParamTypes[1]; 3687 ParamTypes[1] = *Ptr; 3688 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 3689 } 3690 break; 3691 3692 case OO_ArrowStar: 3693 // C++ [over.built]p11: 3694 // For every quintuple (C1, C2, T, CV1, CV2), where C2 is a class type, 3695 // C1 is the same type as C2 or is a derived class of C2, T is an object 3696 // type or a function type, and CV1 and CV2 are cv-qualifier-seqs, 3697 // there exist candidate operator functions of the form 3698 // CV12 T& operator->*(CV1 C1*, CV2 T C2::*); 3699 // where CV12 is the union of CV1 and CV2. 3700 { 3701 for (BuiltinCandidateTypeSet::iterator Ptr = 3702 CandidateTypes.pointer_begin(); 3703 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3704 QualType C1Ty = (*Ptr); 3705 QualType C1; 3706 QualifierCollector Q1; 3707 if (const PointerType *PointerTy = C1Ty->getAs<PointerType>()) { 3708 C1 = QualType(Q1.strip(PointerTy->getPointeeType()), 0); 3709 if (!isa<RecordType>(C1)) 3710 continue; 3711 } 3712 for (BuiltinCandidateTypeSet::iterator 3713 MemPtr = CandidateTypes.member_pointer_begin(), 3714 MemPtrEnd = CandidateTypes.member_pointer_end(); 3715 MemPtr != MemPtrEnd; ++MemPtr) { 3716 const MemberPointerType *mptr = cast<MemberPointerType>(*MemPtr); 3717 QualType C2 = QualType(mptr->getClass(), 0); 3718 C2 = C2.getUnqualifiedType(); 3719 if (C1 != C2 && !IsDerivedFrom(C1, C2)) 3720 break; 3721 QualType ParamTypes[2] = { *Ptr, *MemPtr }; 3722 // build CV12 T& 3723 QualType T = mptr->getPointeeType(); 3724 T = Q1.apply(T); 3725 QualType ResultTy = Context.getLValueReferenceType(T); 3726 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 3727 } 3728 } 3729 } 3730 break; 3731 3732 case OO_Conditional: 3733 // Note that we don't consider the first argument, since it has been 3734 // contextually converted to bool long ago. The candidates below are 3735 // therefore added as binary. 3736 // 3737 // C++ [over.built]p24: 3738 // For every type T, where T is a pointer or pointer-to-member type, 3739 // there exist candidate operator functions of the form 3740 // 3741 // T operator?(bool, T, T); 3742 // 3743 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(), 3744 E = CandidateTypes.pointer_end(); Ptr != E; ++Ptr) { 3745 QualType ParamTypes[2] = { *Ptr, *Ptr }; 3746 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3747 } 3748 for (BuiltinCandidateTypeSet::iterator Ptr = 3749 CandidateTypes.member_pointer_begin(), 3750 E = CandidateTypes.member_pointer_end(); Ptr != E; ++Ptr) { 3751 QualType ParamTypes[2] = { *Ptr, *Ptr }; 3752 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3753 } 3754 goto Conditional; 3755 } 3756} 3757 3758/// \brief Add function candidates found via argument-dependent lookup 3759/// to the set of overloading candidates. 3760/// 3761/// This routine performs argument-dependent name lookup based on the 3762/// given function name (which may also be an operator name) and adds 3763/// all of the overload candidates found by ADL to the overload 3764/// candidate set (C++ [basic.lookup.argdep]). 3765void 3766Sema::AddArgumentDependentLookupCandidates(DeclarationName Name, 3767 Expr **Args, unsigned NumArgs, 3768 bool HasExplicitTemplateArgs, 3769 const TemplateArgument *ExplicitTemplateArgs, 3770 unsigned NumExplicitTemplateArgs, 3771 OverloadCandidateSet& CandidateSet, 3772 bool PartialOverloading) { 3773 FunctionSet Functions; 3774 3775 // FIXME: Should we be trafficking in canonical function decls throughout? 3776 3777 // Record all of the function candidates that we've already 3778 // added to the overload set, so that we don't add those same 3779 // candidates a second time. 3780 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 3781 CandEnd = CandidateSet.end(); 3782 Cand != CandEnd; ++Cand) 3783 if (Cand->Function) { 3784 Functions.insert(Cand->Function); 3785 if (FunctionTemplateDecl *FunTmpl = Cand->Function->getPrimaryTemplate()) 3786 Functions.insert(FunTmpl); 3787 } 3788 3789 // FIXME: Pass in the explicit template arguments? 3790 ArgumentDependentLookup(Name, Args, NumArgs, Functions); 3791 3792 // Erase all of the candidates we already knew about. 3793 // FIXME: This is suboptimal. Is there a better way? 3794 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 3795 CandEnd = CandidateSet.end(); 3796 Cand != CandEnd; ++Cand) 3797 if (Cand->Function) { 3798 Functions.erase(Cand->Function); 3799 if (FunctionTemplateDecl *FunTmpl = Cand->Function->getPrimaryTemplate()) 3800 Functions.erase(FunTmpl); 3801 } 3802 3803 // For each of the ADL candidates we found, add it to the overload 3804 // set. 3805 for (FunctionSet::iterator Func = Functions.begin(), 3806 FuncEnd = Functions.end(); 3807 Func != FuncEnd; ++Func) { 3808 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*Func)) { 3809 if (HasExplicitTemplateArgs) 3810 continue; 3811 3812 AddOverloadCandidate(FD, Args, NumArgs, CandidateSet, 3813 false, false, PartialOverloading); 3814 } else 3815 AddTemplateOverloadCandidate(cast<FunctionTemplateDecl>(*Func), 3816 HasExplicitTemplateArgs, 3817 ExplicitTemplateArgs, 3818 NumExplicitTemplateArgs, 3819 Args, NumArgs, CandidateSet); 3820 } 3821} 3822 3823/// isBetterOverloadCandidate - Determines whether the first overload 3824/// candidate is a better candidate than the second (C++ 13.3.3p1). 3825bool 3826Sema::isBetterOverloadCandidate(const OverloadCandidate& Cand1, 3827 const OverloadCandidate& Cand2) { 3828 // Define viable functions to be better candidates than non-viable 3829 // functions. 3830 if (!Cand2.Viable) 3831 return Cand1.Viable; 3832 else if (!Cand1.Viable) 3833 return false; 3834 3835 // C++ [over.match.best]p1: 3836 // 3837 // -- if F is a static member function, ICS1(F) is defined such 3838 // that ICS1(F) is neither better nor worse than ICS1(G) for 3839 // any function G, and, symmetrically, ICS1(G) is neither 3840 // better nor worse than ICS1(F). 3841 unsigned StartArg = 0; 3842 if (Cand1.IgnoreObjectArgument || Cand2.IgnoreObjectArgument) 3843 StartArg = 1; 3844 3845 // C++ [over.match.best]p1: 3846 // A viable function F1 is defined to be a better function than another 3847 // viable function F2 if for all arguments i, ICSi(F1) is not a worse 3848 // conversion sequence than ICSi(F2), and then... 3849 unsigned NumArgs = Cand1.Conversions.size(); 3850 assert(Cand2.Conversions.size() == NumArgs && "Overload candidate mismatch"); 3851 bool HasBetterConversion = false; 3852 for (unsigned ArgIdx = StartArg; ArgIdx < NumArgs; ++ArgIdx) { 3853 switch (CompareImplicitConversionSequences(Cand1.Conversions[ArgIdx], 3854 Cand2.Conversions[ArgIdx])) { 3855 case ImplicitConversionSequence::Better: 3856 // Cand1 has a better conversion sequence. 3857 HasBetterConversion = true; 3858 break; 3859 3860 case ImplicitConversionSequence::Worse: 3861 // Cand1 can't be better than Cand2. 3862 return false; 3863 3864 case ImplicitConversionSequence::Indistinguishable: 3865 // Do nothing. 3866 break; 3867 } 3868 } 3869 3870 // -- for some argument j, ICSj(F1) is a better conversion sequence than 3871 // ICSj(F2), or, if not that, 3872 if (HasBetterConversion) 3873 return true; 3874 3875 // - F1 is a non-template function and F2 is a function template 3876 // specialization, or, if not that, 3877 if (Cand1.Function && !Cand1.Function->getPrimaryTemplate() && 3878 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 3879 return true; 3880 3881 // -- F1 and F2 are function template specializations, and the function 3882 // template for F1 is more specialized than the template for F2 3883 // according to the partial ordering rules described in 14.5.5.2, or, 3884 // if not that, 3885 if (Cand1.Function && Cand1.Function->getPrimaryTemplate() && 3886 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 3887 if (FunctionTemplateDecl *BetterTemplate 3888 = getMoreSpecializedTemplate(Cand1.Function->getPrimaryTemplate(), 3889 Cand2.Function->getPrimaryTemplate(), 3890 isa<CXXConversionDecl>(Cand1.Function)? TPOC_Conversion 3891 : TPOC_Call)) 3892 return BetterTemplate == Cand1.Function->getPrimaryTemplate(); 3893 3894 // -- the context is an initialization by user-defined conversion 3895 // (see 8.5, 13.3.1.5) and the standard conversion sequence 3896 // from the return type of F1 to the destination type (i.e., 3897 // the type of the entity being initialized) is a better 3898 // conversion sequence than the standard conversion sequence 3899 // from the return type of F2 to the destination type. 3900 if (Cand1.Function && Cand2.Function && 3901 isa<CXXConversionDecl>(Cand1.Function) && 3902 isa<CXXConversionDecl>(Cand2.Function)) { 3903 switch (CompareStandardConversionSequences(Cand1.FinalConversion, 3904 Cand2.FinalConversion)) { 3905 case ImplicitConversionSequence::Better: 3906 // Cand1 has a better conversion sequence. 3907 return true; 3908 3909 case ImplicitConversionSequence::Worse: 3910 // Cand1 can't be better than Cand2. 3911 return false; 3912 3913 case ImplicitConversionSequence::Indistinguishable: 3914 // Do nothing 3915 break; 3916 } 3917 } 3918 3919 return false; 3920} 3921 3922/// \brief Computes the best viable function (C++ 13.3.3) 3923/// within an overload candidate set. 3924/// 3925/// \param CandidateSet the set of candidate functions. 3926/// 3927/// \param Loc the location of the function name (or operator symbol) for 3928/// which overload resolution occurs. 3929/// 3930/// \param Best f overload resolution was successful or found a deleted 3931/// function, Best points to the candidate function found. 3932/// 3933/// \returns The result of overload resolution. 3934Sema::OverloadingResult 3935Sema::BestViableFunction(OverloadCandidateSet& CandidateSet, 3936 SourceLocation Loc, 3937 OverloadCandidateSet::iterator& Best) { 3938 // Find the best viable function. 3939 Best = CandidateSet.end(); 3940 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 3941 Cand != CandidateSet.end(); ++Cand) { 3942 if (Cand->Viable) { 3943 if (Best == CandidateSet.end() || isBetterOverloadCandidate(*Cand, *Best)) 3944 Best = Cand; 3945 } 3946 } 3947 3948 // If we didn't find any viable functions, abort. 3949 if (Best == CandidateSet.end()) 3950 return OR_No_Viable_Function; 3951 3952 // Make sure that this function is better than every other viable 3953 // function. If not, we have an ambiguity. 3954 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 3955 Cand != CandidateSet.end(); ++Cand) { 3956 if (Cand->Viable && 3957 Cand != Best && 3958 !isBetterOverloadCandidate(*Best, *Cand)) { 3959 Best = CandidateSet.end(); 3960 return OR_Ambiguous; 3961 } 3962 } 3963 3964 // Best is the best viable function. 3965 if (Best->Function && 3966 (Best->Function->isDeleted() || 3967 Best->Function->getAttr<UnavailableAttr>())) 3968 return OR_Deleted; 3969 3970 // C++ [basic.def.odr]p2: 3971 // An overloaded function is used if it is selected by overload resolution 3972 // when referred to from a potentially-evaluated expression. [Note: this 3973 // covers calls to named functions (5.2.2), operator overloading 3974 // (clause 13), user-defined conversions (12.3.2), allocation function for 3975 // placement new (5.3.4), as well as non-default initialization (8.5). 3976 if (Best->Function) 3977 MarkDeclarationReferenced(Loc, Best->Function); 3978 return OR_Success; 3979} 3980 3981/// PrintOverloadCandidates - When overload resolution fails, prints 3982/// diagnostic messages containing the candidates in the candidate 3983/// set. If OnlyViable is true, only viable candidates will be printed. 3984void 3985Sema::PrintOverloadCandidates(OverloadCandidateSet& CandidateSet, 3986 bool OnlyViable, 3987 const char *Opc, 3988 SourceLocation OpLoc) { 3989 OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 3990 LastCand = CandidateSet.end(); 3991 bool Reported = false; 3992 for (; Cand != LastCand; ++Cand) { 3993 if (Cand->Viable || !OnlyViable) { 3994 if (Cand->Function) { 3995 if (Cand->Function->isDeleted() || 3996 Cand->Function->getAttr<UnavailableAttr>()) { 3997 // Deleted or "unavailable" function. 3998 Diag(Cand->Function->getLocation(), diag::err_ovl_candidate_deleted) 3999 << Cand->Function->isDeleted(); 4000 } else if (FunctionTemplateDecl *FunTmpl 4001 = Cand->Function->getPrimaryTemplate()) { 4002 // Function template specialization 4003 // FIXME: Give a better reason! 4004 Diag(Cand->Function->getLocation(), diag::err_ovl_template_candidate) 4005 << getTemplateArgumentBindingsText(FunTmpl->getTemplateParameters(), 4006 *Cand->Function->getTemplateSpecializationArgs()); 4007 } else { 4008 // Normal function 4009 bool errReported = false; 4010 if (!Cand->Viable && Cand->Conversions.size() > 0) { 4011 for (int i = Cand->Conversions.size()-1; i >= 0; i--) { 4012 const ImplicitConversionSequence &Conversion = 4013 Cand->Conversions[i]; 4014 if ((Conversion.ConversionKind != 4015 ImplicitConversionSequence::BadConversion) || 4016 Conversion.ConversionFunctionSet.size() == 0) 4017 continue; 4018 Diag(Cand->Function->getLocation(), 4019 diag::err_ovl_candidate_not_viable) << (i+1); 4020 errReported = true; 4021 for (int j = Conversion.ConversionFunctionSet.size()-1; 4022 j >= 0; j--) { 4023 FunctionDecl *Func = Conversion.ConversionFunctionSet[j]; 4024 Diag(Func->getLocation(), diag::err_ovl_candidate); 4025 } 4026 } 4027 } 4028 if (!errReported) 4029 Diag(Cand->Function->getLocation(), diag::err_ovl_candidate); 4030 } 4031 } else if (Cand->IsSurrogate) { 4032 // Desugar the type of the surrogate down to a function type, 4033 // retaining as many typedefs as possible while still showing 4034 // the function type (and, therefore, its parameter types). 4035 QualType FnType = Cand->Surrogate->getConversionType(); 4036 bool isLValueReference = false; 4037 bool isRValueReference = false; 4038 bool isPointer = false; 4039 if (const LValueReferenceType *FnTypeRef = 4040 FnType->getAs<LValueReferenceType>()) { 4041 FnType = FnTypeRef->getPointeeType(); 4042 isLValueReference = true; 4043 } else if (const RValueReferenceType *FnTypeRef = 4044 FnType->getAs<RValueReferenceType>()) { 4045 FnType = FnTypeRef->getPointeeType(); 4046 isRValueReference = true; 4047 } 4048 if (const PointerType *FnTypePtr = FnType->getAs<PointerType>()) { 4049 FnType = FnTypePtr->getPointeeType(); 4050 isPointer = true; 4051 } 4052 // Desugar down to a function type. 4053 FnType = QualType(FnType->getAs<FunctionType>(), 0); 4054 // Reconstruct the pointer/reference as appropriate. 4055 if (isPointer) FnType = Context.getPointerType(FnType); 4056 if (isRValueReference) FnType = Context.getRValueReferenceType(FnType); 4057 if (isLValueReference) FnType = Context.getLValueReferenceType(FnType); 4058 4059 Diag(Cand->Surrogate->getLocation(), diag::err_ovl_surrogate_cand) 4060 << FnType; 4061 } else if (OnlyViable) { 4062 assert(Cand->Conversions.size() <= 2 && 4063 "builtin-binary-operator-not-binary"); 4064 if (Cand->Conversions.size() == 1) 4065 Diag(OpLoc, diag::err_ovl_builtin_unary_candidate) 4066 << Opc << Cand->BuiltinTypes.ParamTypes[0]; 4067 else 4068 Diag(OpLoc, diag::err_ovl_builtin_binary_candidate) 4069 << Opc << Cand->BuiltinTypes.ParamTypes[0] 4070 << Cand->BuiltinTypes.ParamTypes[1]; 4071 } 4072 else if (!Cand->Viable && !Reported) { 4073 // Non-viability might be due to ambiguous user-defined conversions, 4074 // needed for built-in operators. Report them as well, but only once 4075 // as we have typically many built-in candidates. 4076 unsigned NoOperands = Cand->Conversions.size(); 4077 for (unsigned ArgIdx = 0; ArgIdx < NoOperands; ++ArgIdx) { 4078 const ImplicitConversionSequence &ICS = Cand->Conversions[ArgIdx]; 4079 if (ICS.ConversionKind != ImplicitConversionSequence::BadConversion || 4080 ICS.ConversionFunctionSet.empty()) 4081 continue; 4082 if (CXXConversionDecl *Func = dyn_cast<CXXConversionDecl>( 4083 Cand->Conversions[ArgIdx].ConversionFunctionSet[0])) { 4084 QualType FromTy = 4085 QualType( 4086 static_cast<Type*>(ICS.UserDefined.Before.FromTypePtr),0); 4087 Diag(OpLoc,diag::note_ambiguous_type_conversion) 4088 << FromTy << Func->getConversionType(); 4089 } 4090 for (unsigned j = 0; j < ICS.ConversionFunctionSet.size(); j++) { 4091 FunctionDecl *Func = 4092 Cand->Conversions[ArgIdx].ConversionFunctionSet[j]; 4093 Diag(Func->getLocation(),diag::err_ovl_candidate); 4094 } 4095 } 4096 Reported = true; 4097 } 4098 } 4099 } 4100} 4101 4102/// ResolveAddressOfOverloadedFunction - Try to resolve the address of 4103/// an overloaded function (C++ [over.over]), where @p From is an 4104/// expression with overloaded function type and @p ToType is the type 4105/// we're trying to resolve to. For example: 4106/// 4107/// @code 4108/// int f(double); 4109/// int f(int); 4110/// 4111/// int (*pfd)(double) = f; // selects f(double) 4112/// @endcode 4113/// 4114/// This routine returns the resulting FunctionDecl if it could be 4115/// resolved, and NULL otherwise. When @p Complain is true, this 4116/// routine will emit diagnostics if there is an error. 4117FunctionDecl * 4118Sema::ResolveAddressOfOverloadedFunction(Expr *From, QualType ToType, 4119 bool Complain) { 4120 QualType FunctionType = ToType; 4121 bool IsMember = false; 4122 if (const PointerType *ToTypePtr = ToType->getAs<PointerType>()) 4123 FunctionType = ToTypePtr->getPointeeType(); 4124 else if (const ReferenceType *ToTypeRef = ToType->getAs<ReferenceType>()) 4125 FunctionType = ToTypeRef->getPointeeType(); 4126 else if (const MemberPointerType *MemTypePtr = 4127 ToType->getAs<MemberPointerType>()) { 4128 FunctionType = MemTypePtr->getPointeeType(); 4129 IsMember = true; 4130 } 4131 4132 // We only look at pointers or references to functions. 4133 FunctionType = Context.getCanonicalType(FunctionType).getUnqualifiedType(); 4134 if (!FunctionType->isFunctionType()) 4135 return 0; 4136 4137 // Find the actual overloaded function declaration. 4138 OverloadedFunctionDecl *Ovl = 0; 4139 4140 // C++ [over.over]p1: 4141 // [...] [Note: any redundant set of parentheses surrounding the 4142 // overloaded function name is ignored (5.1). ] 4143 Expr *OvlExpr = From->IgnoreParens(); 4144 4145 // C++ [over.over]p1: 4146 // [...] The overloaded function name can be preceded by the & 4147 // operator. 4148 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(OvlExpr)) { 4149 if (UnOp->getOpcode() == UnaryOperator::AddrOf) 4150 OvlExpr = UnOp->getSubExpr()->IgnoreParens(); 4151 } 4152 4153 // Try to dig out the overloaded function. 4154 FunctionTemplateDecl *FunctionTemplate = 0; 4155 if (DeclRefExpr *DR = dyn_cast<DeclRefExpr>(OvlExpr)) { 4156 Ovl = dyn_cast<OverloadedFunctionDecl>(DR->getDecl()); 4157 FunctionTemplate = dyn_cast<FunctionTemplateDecl>(DR->getDecl()); 4158 } else if (MemberExpr *ME = dyn_cast<MemberExpr>(OvlExpr)) { 4159 Ovl = dyn_cast<OverloadedFunctionDecl>(ME->getMemberDecl()); 4160 FunctionTemplate = dyn_cast<FunctionTemplateDecl>(ME->getMemberDecl()); 4161 // FIXME: Explicit template arguments 4162 } 4163 // FIXME: TemplateIdRefExpr? 4164 4165 // If there's no overloaded function declaration or function template, 4166 // we're done. 4167 if (!Ovl && !FunctionTemplate) 4168 return 0; 4169 4170 OverloadIterator Fun; 4171 if (Ovl) 4172 Fun = Ovl; 4173 else 4174 Fun = FunctionTemplate; 4175 4176 // Look through all of the overloaded functions, searching for one 4177 // whose type matches exactly. 4178 llvm::SmallPtrSet<FunctionDecl *, 4> Matches; 4179 bool FoundNonTemplateFunction = false; 4180 for (OverloadIterator FunEnd; Fun != FunEnd; ++Fun) { 4181 // C++ [over.over]p3: 4182 // Non-member functions and static member functions match 4183 // targets of type "pointer-to-function" or "reference-to-function." 4184 // Nonstatic member functions match targets of 4185 // type "pointer-to-member-function." 4186 // Note that according to DR 247, the containing class does not matter. 4187 4188 if (FunctionTemplateDecl *FunctionTemplate 4189 = dyn_cast<FunctionTemplateDecl>(*Fun)) { 4190 if (CXXMethodDecl *Method 4191 = dyn_cast<CXXMethodDecl>(FunctionTemplate->getTemplatedDecl())) { 4192 // Skip non-static function templates when converting to pointer, and 4193 // static when converting to member pointer. 4194 if (Method->isStatic() == IsMember) 4195 continue; 4196 } else if (IsMember) 4197 continue; 4198 4199 // C++ [over.over]p2: 4200 // If the name is a function template, template argument deduction is 4201 // done (14.8.2.2), and if the argument deduction succeeds, the 4202 // resulting template argument list is used to generate a single 4203 // function template specialization, which is added to the set of 4204 // overloaded functions considered. 4205 // FIXME: We don't really want to build the specialization here, do we? 4206 FunctionDecl *Specialization = 0; 4207 TemplateDeductionInfo Info(Context); 4208 if (TemplateDeductionResult Result 4209 = DeduceTemplateArguments(FunctionTemplate, /*FIXME*/false, 4210 /*FIXME:*/0, /*FIXME:*/0, 4211 FunctionType, Specialization, Info)) { 4212 // FIXME: make a note of the failed deduction for diagnostics. 4213 (void)Result; 4214 } else { 4215 // FIXME: If the match isn't exact, shouldn't we just drop this as 4216 // a candidate? Find a testcase before changing the code. 4217 assert(FunctionType 4218 == Context.getCanonicalType(Specialization->getType())); 4219 Matches.insert( 4220 cast<FunctionDecl>(Specialization->getCanonicalDecl())); 4221 } 4222 } 4223 4224 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(*Fun)) { 4225 // Skip non-static functions when converting to pointer, and static 4226 // when converting to member pointer. 4227 if (Method->isStatic() == IsMember) 4228 continue; 4229 } else if (IsMember) 4230 continue; 4231 4232 if (FunctionDecl *FunDecl = dyn_cast<FunctionDecl>(*Fun)) { 4233 if (FunctionType == Context.getCanonicalType(FunDecl->getType())) { 4234 Matches.insert(cast<FunctionDecl>(Fun->getCanonicalDecl())); 4235 FoundNonTemplateFunction = true; 4236 } 4237 } 4238 } 4239 4240 // If there were 0 or 1 matches, we're done. 4241 if (Matches.empty()) 4242 return 0; 4243 else if (Matches.size() == 1) 4244 return *Matches.begin(); 4245 4246 // C++ [over.over]p4: 4247 // If more than one function is selected, [...] 4248 typedef llvm::SmallPtrSet<FunctionDecl *, 4>::iterator MatchIter; 4249 if (!FoundNonTemplateFunction) { 4250 // [...] and any given function template specialization F1 is 4251 // eliminated if the set contains a second function template 4252 // specialization whose function template is more specialized 4253 // than the function template of F1 according to the partial 4254 // ordering rules of 14.5.5.2. 4255 4256 // The algorithm specified above is quadratic. We instead use a 4257 // two-pass algorithm (similar to the one used to identify the 4258 // best viable function in an overload set) that identifies the 4259 // best function template (if it exists). 4260 llvm::SmallVector<FunctionDecl *, 8> TemplateMatches(Matches.begin(), 4261 Matches.end()); 4262 return getMostSpecialized(TemplateMatches.data(), TemplateMatches.size(), 4263 TPOC_Other, From->getLocStart(), 4264 PDiag(), 4265 PDiag(diag::err_addr_ovl_ambiguous) 4266 << TemplateMatches[0]->getDeclName(), 4267 PDiag(diag::err_ovl_template_candidate)); 4268 } 4269 4270 // [...] any function template specializations in the set are 4271 // eliminated if the set also contains a non-template function, [...] 4272 llvm::SmallVector<FunctionDecl *, 4> RemainingMatches; 4273 for (MatchIter M = Matches.begin(), MEnd = Matches.end(); M != MEnd; ++M) 4274 if ((*M)->getPrimaryTemplate() == 0) 4275 RemainingMatches.push_back(*M); 4276 4277 // [...] After such eliminations, if any, there shall remain exactly one 4278 // selected function. 4279 if (RemainingMatches.size() == 1) 4280 return RemainingMatches.front(); 4281 4282 // FIXME: We should probably return the same thing that BestViableFunction 4283 // returns (even if we issue the diagnostics here). 4284 Diag(From->getLocStart(), diag::err_addr_ovl_ambiguous) 4285 << RemainingMatches[0]->getDeclName(); 4286 for (unsigned I = 0, N = RemainingMatches.size(); I != N; ++I) 4287 Diag(RemainingMatches[I]->getLocation(), diag::err_ovl_candidate); 4288 return 0; 4289} 4290 4291/// \brief Add a single candidate to the overload set. 4292static void AddOverloadedCallCandidate(Sema &S, 4293 AnyFunctionDecl Callee, 4294 bool &ArgumentDependentLookup, 4295 bool HasExplicitTemplateArgs, 4296 const TemplateArgument *ExplicitTemplateArgs, 4297 unsigned NumExplicitTemplateArgs, 4298 Expr **Args, unsigned NumArgs, 4299 OverloadCandidateSet &CandidateSet, 4300 bool PartialOverloading) { 4301 if (FunctionDecl *Func = dyn_cast<FunctionDecl>(Callee)) { 4302 assert(!HasExplicitTemplateArgs && "Explicit template arguments?"); 4303 S.AddOverloadCandidate(Func, Args, NumArgs, CandidateSet, false, false, 4304 PartialOverloading); 4305 4306 if (Func->getDeclContext()->isRecord() || 4307 Func->getDeclContext()->isFunctionOrMethod()) 4308 ArgumentDependentLookup = false; 4309 return; 4310 } 4311 4312 FunctionTemplateDecl *FuncTemplate = cast<FunctionTemplateDecl>(Callee); 4313 S.AddTemplateOverloadCandidate(FuncTemplate, HasExplicitTemplateArgs, 4314 ExplicitTemplateArgs, 4315 NumExplicitTemplateArgs, 4316 Args, NumArgs, CandidateSet); 4317 4318 if (FuncTemplate->getDeclContext()->isRecord()) 4319 ArgumentDependentLookup = false; 4320} 4321 4322/// \brief Add the overload candidates named by callee and/or found by argument 4323/// dependent lookup to the given overload set. 4324void Sema::AddOverloadedCallCandidates(NamedDecl *Callee, 4325 DeclarationName &UnqualifiedName, 4326 bool &ArgumentDependentLookup, 4327 bool HasExplicitTemplateArgs, 4328 const TemplateArgument *ExplicitTemplateArgs, 4329 unsigned NumExplicitTemplateArgs, 4330 Expr **Args, unsigned NumArgs, 4331 OverloadCandidateSet &CandidateSet, 4332 bool PartialOverloading) { 4333 // Add the functions denoted by Callee to the set of candidate 4334 // functions. While we're doing so, track whether argument-dependent 4335 // lookup still applies, per: 4336 // 4337 // C++0x [basic.lookup.argdep]p3: 4338 // Let X be the lookup set produced by unqualified lookup (3.4.1) 4339 // and let Y be the lookup set produced by argument dependent 4340 // lookup (defined as follows). If X contains 4341 // 4342 // -- a declaration of a class member, or 4343 // 4344 // -- a block-scope function declaration that is not a 4345 // using-declaration (FIXME: check for using declaration), or 4346 // 4347 // -- a declaration that is neither a function or a function 4348 // template 4349 // 4350 // then Y is empty. 4351 if (!Callee) { 4352 // Nothing to do. 4353 } else if (OverloadedFunctionDecl *Ovl 4354 = dyn_cast<OverloadedFunctionDecl>(Callee)) { 4355 for (OverloadedFunctionDecl::function_iterator Func = Ovl->function_begin(), 4356 FuncEnd = Ovl->function_end(); 4357 Func != FuncEnd; ++Func) 4358 AddOverloadedCallCandidate(*this, *Func, ArgumentDependentLookup, 4359 HasExplicitTemplateArgs, 4360 ExplicitTemplateArgs, NumExplicitTemplateArgs, 4361 Args, NumArgs, CandidateSet, 4362 PartialOverloading); 4363 } else if (isa<FunctionDecl>(Callee) || isa<FunctionTemplateDecl>(Callee)) 4364 AddOverloadedCallCandidate(*this, 4365 AnyFunctionDecl::getFromNamedDecl(Callee), 4366 ArgumentDependentLookup, 4367 HasExplicitTemplateArgs, 4368 ExplicitTemplateArgs, NumExplicitTemplateArgs, 4369 Args, NumArgs, CandidateSet, 4370 PartialOverloading); 4371 // FIXME: assert isa<FunctionDecl> || isa<FunctionTemplateDecl> rather than 4372 // checking dynamically. 4373 4374 if (Callee) 4375 UnqualifiedName = Callee->getDeclName(); 4376 4377 if (ArgumentDependentLookup) 4378 AddArgumentDependentLookupCandidates(UnqualifiedName, Args, NumArgs, 4379 HasExplicitTemplateArgs, 4380 ExplicitTemplateArgs, 4381 NumExplicitTemplateArgs, 4382 CandidateSet, 4383 PartialOverloading); 4384} 4385 4386/// ResolveOverloadedCallFn - Given the call expression that calls Fn 4387/// (which eventually refers to the declaration Func) and the call 4388/// arguments Args/NumArgs, attempt to resolve the function call down 4389/// to a specific function. If overload resolution succeeds, returns 4390/// the function declaration produced by overload 4391/// resolution. Otherwise, emits diagnostics, deletes all of the 4392/// arguments and Fn, and returns NULL. 4393FunctionDecl *Sema::ResolveOverloadedCallFn(Expr *Fn, NamedDecl *Callee, 4394 DeclarationName UnqualifiedName, 4395 bool HasExplicitTemplateArgs, 4396 const TemplateArgument *ExplicitTemplateArgs, 4397 unsigned NumExplicitTemplateArgs, 4398 SourceLocation LParenLoc, 4399 Expr **Args, unsigned NumArgs, 4400 SourceLocation *CommaLocs, 4401 SourceLocation RParenLoc, 4402 bool &ArgumentDependentLookup) { 4403 OverloadCandidateSet CandidateSet; 4404 4405 // Add the functions denoted by Callee to the set of candidate 4406 // functions. 4407 AddOverloadedCallCandidates(Callee, UnqualifiedName, ArgumentDependentLookup, 4408 HasExplicitTemplateArgs, ExplicitTemplateArgs, 4409 NumExplicitTemplateArgs, Args, NumArgs, 4410 CandidateSet); 4411 OverloadCandidateSet::iterator Best; 4412 switch (BestViableFunction(CandidateSet, Fn->getLocStart(), Best)) { 4413 case OR_Success: 4414 return Best->Function; 4415 4416 case OR_No_Viable_Function: 4417 Diag(Fn->getSourceRange().getBegin(), 4418 diag::err_ovl_no_viable_function_in_call) 4419 << UnqualifiedName << Fn->getSourceRange(); 4420 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4421 break; 4422 4423 case OR_Ambiguous: 4424 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_ambiguous_call) 4425 << UnqualifiedName << Fn->getSourceRange(); 4426 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4427 break; 4428 4429 case OR_Deleted: 4430 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_deleted_call) 4431 << Best->Function->isDeleted() 4432 << UnqualifiedName 4433 << Fn->getSourceRange(); 4434 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4435 break; 4436 } 4437 4438 // Overload resolution failed. Destroy all of the subexpressions and 4439 // return NULL. 4440 Fn->Destroy(Context); 4441 for (unsigned Arg = 0; Arg < NumArgs; ++Arg) 4442 Args[Arg]->Destroy(Context); 4443 return 0; 4444} 4445 4446/// \brief Create a unary operation that may resolve to an overloaded 4447/// operator. 4448/// 4449/// \param OpLoc The location of the operator itself (e.g., '*'). 4450/// 4451/// \param OpcIn The UnaryOperator::Opcode that describes this 4452/// operator. 4453/// 4454/// \param Functions The set of non-member functions that will be 4455/// considered by overload resolution. The caller needs to build this 4456/// set based on the context using, e.g., 4457/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 4458/// set should not contain any member functions; those will be added 4459/// by CreateOverloadedUnaryOp(). 4460/// 4461/// \param input The input argument. 4462Sema::OwningExprResult Sema::CreateOverloadedUnaryOp(SourceLocation OpLoc, 4463 unsigned OpcIn, 4464 FunctionSet &Functions, 4465 ExprArg input) { 4466 UnaryOperator::Opcode Opc = static_cast<UnaryOperator::Opcode>(OpcIn); 4467 Expr *Input = (Expr *)input.get(); 4468 4469 OverloadedOperatorKind Op = UnaryOperator::getOverloadedOperator(Opc); 4470 assert(Op != OO_None && "Invalid opcode for overloaded unary operator"); 4471 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 4472 4473 Expr *Args[2] = { Input, 0 }; 4474 unsigned NumArgs = 1; 4475 4476 // For post-increment and post-decrement, add the implicit '0' as 4477 // the second argument, so that we know this is a post-increment or 4478 // post-decrement. 4479 if (Opc == UnaryOperator::PostInc || Opc == UnaryOperator::PostDec) { 4480 llvm::APSInt Zero(Context.getTypeSize(Context.IntTy), false); 4481 Args[1] = new (Context) IntegerLiteral(Zero, Context.IntTy, 4482 SourceLocation()); 4483 NumArgs = 2; 4484 } 4485 4486 if (Input->isTypeDependent()) { 4487 OverloadedFunctionDecl *Overloads 4488 = OverloadedFunctionDecl::Create(Context, CurContext, OpName); 4489 for (FunctionSet::iterator Func = Functions.begin(), 4490 FuncEnd = Functions.end(); 4491 Func != FuncEnd; ++Func) 4492 Overloads->addOverload(*Func); 4493 4494 DeclRefExpr *Fn = new (Context) DeclRefExpr(Overloads, Context.OverloadTy, 4495 OpLoc, false, false); 4496 4497 input.release(); 4498 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 4499 &Args[0], NumArgs, 4500 Context.DependentTy, 4501 OpLoc)); 4502 } 4503 4504 // Build an empty overload set. 4505 OverloadCandidateSet CandidateSet; 4506 4507 // Add the candidates from the given function set. 4508 AddFunctionCandidates(Functions, &Args[0], NumArgs, CandidateSet, false); 4509 4510 // Add operator candidates that are member functions. 4511 AddMemberOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 4512 4513 // Add builtin operator candidates. 4514 AddBuiltinOperatorCandidates(Op, &Args[0], NumArgs, CandidateSet); 4515 4516 // Perform overload resolution. 4517 OverloadCandidateSet::iterator Best; 4518 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 4519 case OR_Success: { 4520 // We found a built-in operator or an overloaded operator. 4521 FunctionDecl *FnDecl = Best->Function; 4522 4523 if (FnDecl) { 4524 // We matched an overloaded operator. Build a call to that 4525 // operator. 4526 4527 // Convert the arguments. 4528 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 4529 if (PerformObjectArgumentInitialization(Input, Method)) 4530 return ExprError(); 4531 } else { 4532 // Convert the arguments. 4533 if (PerformCopyInitialization(Input, 4534 FnDecl->getParamDecl(0)->getType(), 4535 "passing")) 4536 return ExprError(); 4537 } 4538 4539 // Determine the result type 4540 QualType ResultTy = FnDecl->getResultType().getNonReferenceType(); 4541 4542 // Build the actual expression node. 4543 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 4544 SourceLocation()); 4545 UsualUnaryConversions(FnExpr); 4546 4547 input.release(); 4548 4549 ExprOwningPtr<CallExpr> TheCall(this, 4550 new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 4551 &Input, 1, ResultTy, OpLoc)); 4552 4553 if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall.get(), 4554 FnDecl)) 4555 return ExprError(); 4556 4557 return MaybeBindToTemporary(TheCall.release()); 4558 } else { 4559 // We matched a built-in operator. Convert the arguments, then 4560 // break out so that we will build the appropriate built-in 4561 // operator node. 4562 if (PerformImplicitConversion(Input, Best->BuiltinTypes.ParamTypes[0], 4563 Best->Conversions[0], "passing")) 4564 return ExprError(); 4565 4566 break; 4567 } 4568 } 4569 4570 case OR_No_Viable_Function: 4571 // No viable function; fall through to handling this as a 4572 // built-in operator, which will produce an error message for us. 4573 break; 4574 4575 case OR_Ambiguous: 4576 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 4577 << UnaryOperator::getOpcodeStr(Opc) 4578 << Input->getSourceRange(); 4579 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true, 4580 UnaryOperator::getOpcodeStr(Opc), OpLoc); 4581 return ExprError(); 4582 4583 case OR_Deleted: 4584 Diag(OpLoc, diag::err_ovl_deleted_oper) 4585 << Best->Function->isDeleted() 4586 << UnaryOperator::getOpcodeStr(Opc) 4587 << Input->getSourceRange(); 4588 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4589 return ExprError(); 4590 } 4591 4592 // Either we found no viable overloaded operator or we matched a 4593 // built-in operator. In either case, fall through to trying to 4594 // build a built-in operation. 4595 input.release(); 4596 return CreateBuiltinUnaryOp(OpLoc, Opc, Owned(Input)); 4597} 4598 4599/// \brief Create a binary operation that may resolve to an overloaded 4600/// operator. 4601/// 4602/// \param OpLoc The location of the operator itself (e.g., '+'). 4603/// 4604/// \param OpcIn The BinaryOperator::Opcode that describes this 4605/// operator. 4606/// 4607/// \param Functions The set of non-member functions that will be 4608/// considered by overload resolution. The caller needs to build this 4609/// set based on the context using, e.g., 4610/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 4611/// set should not contain any member functions; those will be added 4612/// by CreateOverloadedBinOp(). 4613/// 4614/// \param LHS Left-hand argument. 4615/// \param RHS Right-hand argument. 4616Sema::OwningExprResult 4617Sema::CreateOverloadedBinOp(SourceLocation OpLoc, 4618 unsigned OpcIn, 4619 FunctionSet &Functions, 4620 Expr *LHS, Expr *RHS) { 4621 Expr *Args[2] = { LHS, RHS }; 4622 LHS=RHS=0; //Please use only Args instead of LHS/RHS couple 4623 4624 BinaryOperator::Opcode Opc = static_cast<BinaryOperator::Opcode>(OpcIn); 4625 OverloadedOperatorKind Op = BinaryOperator::getOverloadedOperator(Opc); 4626 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 4627 4628 // If either side is type-dependent, create an appropriate dependent 4629 // expression. 4630 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 4631 // .* cannot be overloaded. 4632 if (Opc == BinaryOperator::PtrMemD) 4633 return Owned(new (Context) BinaryOperator(Args[0], Args[1], Opc, 4634 Context.DependentTy, OpLoc)); 4635 4636 OverloadedFunctionDecl *Overloads 4637 = OverloadedFunctionDecl::Create(Context, CurContext, OpName); 4638 for (FunctionSet::iterator Func = Functions.begin(), 4639 FuncEnd = Functions.end(); 4640 Func != FuncEnd; ++Func) 4641 Overloads->addOverload(*Func); 4642 4643 DeclRefExpr *Fn = new (Context) DeclRefExpr(Overloads, Context.OverloadTy, 4644 OpLoc, false, false); 4645 4646 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 4647 Args, 2, 4648 Context.DependentTy, 4649 OpLoc)); 4650 } 4651 4652 // If this is the .* operator, which is not overloadable, just 4653 // create a built-in binary operator. 4654 if (Opc == BinaryOperator::PtrMemD) 4655 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 4656 4657 // If this is one of the assignment operators, we only perform 4658 // overload resolution if the left-hand side is a class or 4659 // enumeration type (C++ [expr.ass]p3). 4660 if (Opc >= BinaryOperator::Assign && Opc <= BinaryOperator::OrAssign && 4661 !Args[0]->getType()->isOverloadableType()) 4662 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 4663 4664 // Build an empty overload set. 4665 OverloadCandidateSet CandidateSet; 4666 4667 // Add the candidates from the given function set. 4668 AddFunctionCandidates(Functions, Args, 2, CandidateSet, false); 4669 4670 // Add operator candidates that are member functions. 4671 AddMemberOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 4672 4673 // Add builtin operator candidates. 4674 AddBuiltinOperatorCandidates(Op, Args, 2, CandidateSet); 4675 4676 // Perform overload resolution. 4677 OverloadCandidateSet::iterator Best; 4678 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 4679 case OR_Success: { 4680 // We found a built-in operator or an overloaded operator. 4681 FunctionDecl *FnDecl = Best->Function; 4682 4683 if (FnDecl) { 4684 // We matched an overloaded operator. Build a call to that 4685 // operator. 4686 4687 // Convert the arguments. 4688 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 4689 if (PerformObjectArgumentInitialization(Args[0], Method) || 4690 PerformCopyInitialization(Args[1], FnDecl->getParamDecl(0)->getType(), 4691 "passing")) 4692 return ExprError(); 4693 } else { 4694 // Convert the arguments. 4695 if (PerformCopyInitialization(Args[0], FnDecl->getParamDecl(0)->getType(), 4696 "passing") || 4697 PerformCopyInitialization(Args[1], FnDecl->getParamDecl(1)->getType(), 4698 "passing")) 4699 return ExprError(); 4700 } 4701 4702 // Determine the result type 4703 QualType ResultTy 4704 = FnDecl->getType()->getAs<FunctionType>()->getResultType(); 4705 ResultTy = ResultTy.getNonReferenceType(); 4706 4707 // Build the actual expression node. 4708 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 4709 OpLoc); 4710 UsualUnaryConversions(FnExpr); 4711 4712 ExprOwningPtr<CXXOperatorCallExpr> 4713 TheCall(this, new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 4714 Args, 2, ResultTy, 4715 OpLoc)); 4716 4717 if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall.get(), 4718 FnDecl)) 4719 return ExprError(); 4720 4721 return MaybeBindToTemporary(TheCall.release()); 4722 } else { 4723 // We matched a built-in operator. Convert the arguments, then 4724 // break out so that we will build the appropriate built-in 4725 // operator node. 4726 if (PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 4727 Best->Conversions[0], "passing") || 4728 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 4729 Best->Conversions[1], "passing")) 4730 return ExprError(); 4731 4732 break; 4733 } 4734 } 4735 4736 case OR_No_Viable_Function: { 4737 // C++ [over.match.oper]p9: 4738 // If the operator is the operator , [...] and there are no 4739 // viable functions, then the operator is assumed to be the 4740 // built-in operator and interpreted according to clause 5. 4741 if (Opc == BinaryOperator::Comma) 4742 break; 4743 4744 // For class as left operand for assignment or compound assigment operator 4745 // do not fall through to handling in built-in, but report that no overloaded 4746 // assignment operator found 4747 OwningExprResult Result = ExprError(); 4748 if (Args[0]->getType()->isRecordType() && 4749 Opc >= BinaryOperator::Assign && Opc <= BinaryOperator::OrAssign) { 4750 Diag(OpLoc, diag::err_ovl_no_viable_oper) 4751 << BinaryOperator::getOpcodeStr(Opc) 4752 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 4753 } else { 4754 // No viable function; try to create a built-in operation, which will 4755 // produce an error. Then, show the non-viable candidates. 4756 Result = CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 4757 } 4758 assert(Result.isInvalid() && 4759 "C++ binary operator overloading is missing candidates!"); 4760 if (Result.isInvalid()) 4761 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false, 4762 BinaryOperator::getOpcodeStr(Opc), OpLoc); 4763 return move(Result); 4764 } 4765 4766 case OR_Ambiguous: 4767 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 4768 << BinaryOperator::getOpcodeStr(Opc) 4769 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 4770 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true, 4771 BinaryOperator::getOpcodeStr(Opc), OpLoc); 4772 return ExprError(); 4773 4774 case OR_Deleted: 4775 Diag(OpLoc, diag::err_ovl_deleted_oper) 4776 << Best->Function->isDeleted() 4777 << BinaryOperator::getOpcodeStr(Opc) 4778 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 4779 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4780 return ExprError(); 4781 } 4782 4783 // We matched a built-in operator; build it. 4784 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 4785} 4786 4787/// BuildCallToMemberFunction - Build a call to a member 4788/// function. MemExpr is the expression that refers to the member 4789/// function (and includes the object parameter), Args/NumArgs are the 4790/// arguments to the function call (not including the object 4791/// parameter). The caller needs to validate that the member 4792/// expression refers to a member function or an overloaded member 4793/// function. 4794Sema::ExprResult 4795Sema::BuildCallToMemberFunction(Scope *S, Expr *MemExprE, 4796 SourceLocation LParenLoc, Expr **Args, 4797 unsigned NumArgs, SourceLocation *CommaLocs, 4798 SourceLocation RParenLoc) { 4799 // Dig out the member expression. This holds both the object 4800 // argument and the member function we're referring to. 4801 MemberExpr *MemExpr = 0; 4802 if (ParenExpr *ParenE = dyn_cast<ParenExpr>(MemExprE)) 4803 MemExpr = dyn_cast<MemberExpr>(ParenE->getSubExpr()); 4804 else 4805 MemExpr = dyn_cast<MemberExpr>(MemExprE); 4806 assert(MemExpr && "Building member call without member expression"); 4807 4808 // Extract the object argument. 4809 Expr *ObjectArg = MemExpr->getBase(); 4810 4811 CXXMethodDecl *Method = 0; 4812 if (isa<OverloadedFunctionDecl>(MemExpr->getMemberDecl()) || 4813 isa<FunctionTemplateDecl>(MemExpr->getMemberDecl())) { 4814 // Add overload candidates 4815 OverloadCandidateSet CandidateSet; 4816 DeclarationName DeclName = MemExpr->getMemberDecl()->getDeclName(); 4817 4818 for (OverloadIterator Func(MemExpr->getMemberDecl()), FuncEnd; 4819 Func != FuncEnd; ++Func) { 4820 if ((Method = dyn_cast<CXXMethodDecl>(*Func))) 4821 AddMethodCandidate(Method, ObjectArg, Args, NumArgs, CandidateSet, 4822 /*SuppressUserConversions=*/false); 4823 else 4824 AddMethodTemplateCandidate(cast<FunctionTemplateDecl>(*Func), 4825 MemExpr->hasExplicitTemplateArgumentList(), 4826 MemExpr->getTemplateArgs(), 4827 MemExpr->getNumTemplateArgs(), 4828 ObjectArg, Args, NumArgs, 4829 CandidateSet, 4830 /*SuppressUsedConversions=*/false); 4831 } 4832 4833 OverloadCandidateSet::iterator Best; 4834 switch (BestViableFunction(CandidateSet, MemExpr->getLocStart(), Best)) { 4835 case OR_Success: 4836 Method = cast<CXXMethodDecl>(Best->Function); 4837 break; 4838 4839 case OR_No_Viable_Function: 4840 Diag(MemExpr->getSourceRange().getBegin(), 4841 diag::err_ovl_no_viable_member_function_in_call) 4842 << DeclName << MemExprE->getSourceRange(); 4843 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4844 // FIXME: Leaking incoming expressions! 4845 return true; 4846 4847 case OR_Ambiguous: 4848 Diag(MemExpr->getSourceRange().getBegin(), 4849 diag::err_ovl_ambiguous_member_call) 4850 << DeclName << MemExprE->getSourceRange(); 4851 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4852 // FIXME: Leaking incoming expressions! 4853 return true; 4854 4855 case OR_Deleted: 4856 Diag(MemExpr->getSourceRange().getBegin(), 4857 diag::err_ovl_deleted_member_call) 4858 << Best->Function->isDeleted() 4859 << DeclName << MemExprE->getSourceRange(); 4860 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4861 // FIXME: Leaking incoming expressions! 4862 return true; 4863 } 4864 4865 FixOverloadedFunctionReference(MemExpr, Method); 4866 } else { 4867 Method = dyn_cast<CXXMethodDecl>(MemExpr->getMemberDecl()); 4868 } 4869 4870 assert(Method && "Member call to something that isn't a method?"); 4871 ExprOwningPtr<CXXMemberCallExpr> 4872 TheCall(this, new (Context) CXXMemberCallExpr(Context, MemExpr, Args, 4873 NumArgs, 4874 Method->getResultType().getNonReferenceType(), 4875 RParenLoc)); 4876 4877 // Check for a valid return type. 4878 if (CheckCallReturnType(Method->getResultType(), MemExpr->getMemberLoc(), 4879 TheCall.get(), Method)) 4880 return true; 4881 4882 // Convert the object argument (for a non-static member function call). 4883 if (!Method->isStatic() && 4884 PerformObjectArgumentInitialization(ObjectArg, Method)) 4885 return true; 4886 MemExpr->setBase(ObjectArg); 4887 4888 // Convert the rest of the arguments 4889 const FunctionProtoType *Proto = cast<FunctionProtoType>(Method->getType()); 4890 if (ConvertArgumentsForCall(&*TheCall, MemExpr, Method, Proto, Args, NumArgs, 4891 RParenLoc)) 4892 return true; 4893 4894 if (CheckFunctionCall(Method, TheCall.get())) 4895 return true; 4896 4897 return MaybeBindToTemporary(TheCall.release()).release(); 4898} 4899 4900/// BuildCallToObjectOfClassType - Build a call to an object of class 4901/// type (C++ [over.call.object]), which can end up invoking an 4902/// overloaded function call operator (@c operator()) or performing a 4903/// user-defined conversion on the object argument. 4904Sema::ExprResult 4905Sema::BuildCallToObjectOfClassType(Scope *S, Expr *Object, 4906 SourceLocation LParenLoc, 4907 Expr **Args, unsigned NumArgs, 4908 SourceLocation *CommaLocs, 4909 SourceLocation RParenLoc) { 4910 assert(Object->getType()->isRecordType() && "Requires object type argument"); 4911 const RecordType *Record = Object->getType()->getAs<RecordType>(); 4912 4913 // C++ [over.call.object]p1: 4914 // If the primary-expression E in the function call syntax 4915 // evaluates to a class object of type "cv T", then the set of 4916 // candidate functions includes at least the function call 4917 // operators of T. The function call operators of T are obtained by 4918 // ordinary lookup of the name operator() in the context of 4919 // (E).operator(). 4920 OverloadCandidateSet CandidateSet; 4921 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Call); 4922 DeclContext::lookup_const_iterator Oper, OperEnd; 4923 for (llvm::tie(Oper, OperEnd) = Record->getDecl()->lookup(OpName); 4924 Oper != OperEnd; ++Oper) 4925 AddMethodCandidate(cast<CXXMethodDecl>(*Oper), Object, Args, NumArgs, 4926 CandidateSet, /*SuppressUserConversions=*/false); 4927 4928 // C++ [over.call.object]p2: 4929 // In addition, for each conversion function declared in T of the 4930 // form 4931 // 4932 // operator conversion-type-id () cv-qualifier; 4933 // 4934 // where cv-qualifier is the same cv-qualification as, or a 4935 // greater cv-qualification than, cv, and where conversion-type-id 4936 // denotes the type "pointer to function of (P1,...,Pn) returning 4937 // R", or the type "reference to pointer to function of 4938 // (P1,...,Pn) returning R", or the type "reference to function 4939 // of (P1,...,Pn) returning R", a surrogate call function [...] 4940 // is also considered as a candidate function. Similarly, 4941 // surrogate call functions are added to the set of candidate 4942 // functions for each conversion function declared in an 4943 // accessible base class provided the function is not hidden 4944 // within T by another intervening declaration. 4945 4946 if (!RequireCompleteType(SourceLocation(), Object->getType(), 0)) { 4947 // FIXME: Look in base classes for more conversion operators! 4948 OverloadedFunctionDecl *Conversions 4949 = cast<CXXRecordDecl>(Record->getDecl())->getConversionFunctions(); 4950 for (OverloadedFunctionDecl::function_iterator 4951 Func = Conversions->function_begin(), 4952 FuncEnd = Conversions->function_end(); 4953 Func != FuncEnd; ++Func) { 4954 CXXConversionDecl *Conv; 4955 FunctionTemplateDecl *ConvTemplate; 4956 GetFunctionAndTemplate(*Func, Conv, ConvTemplate); 4957 4958 // Skip over templated conversion functions; they aren't 4959 // surrogates. 4960 if (ConvTemplate) 4961 continue; 4962 4963 // Strip the reference type (if any) and then the pointer type (if 4964 // any) to get down to what might be a function type. 4965 QualType ConvType = Conv->getConversionType().getNonReferenceType(); 4966 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 4967 ConvType = ConvPtrType->getPointeeType(); 4968 4969 if (const FunctionProtoType *Proto = ConvType->getAs<FunctionProtoType>()) 4970 AddSurrogateCandidate(Conv, Proto, Object, Args, NumArgs, CandidateSet); 4971 } 4972 } 4973 4974 // Perform overload resolution. 4975 OverloadCandidateSet::iterator Best; 4976 switch (BestViableFunction(CandidateSet, Object->getLocStart(), Best)) { 4977 case OR_Success: 4978 // Overload resolution succeeded; we'll build the appropriate call 4979 // below. 4980 break; 4981 4982 case OR_No_Viable_Function: 4983 Diag(Object->getSourceRange().getBegin(), 4984 diag::err_ovl_no_viable_object_call) 4985 << Object->getType() << Object->getSourceRange(); 4986 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4987 break; 4988 4989 case OR_Ambiguous: 4990 Diag(Object->getSourceRange().getBegin(), 4991 diag::err_ovl_ambiguous_object_call) 4992 << Object->getType() << Object->getSourceRange(); 4993 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4994 break; 4995 4996 case OR_Deleted: 4997 Diag(Object->getSourceRange().getBegin(), 4998 diag::err_ovl_deleted_object_call) 4999 << Best->Function->isDeleted() 5000 << Object->getType() << Object->getSourceRange(); 5001 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 5002 break; 5003 } 5004 5005 if (Best == CandidateSet.end()) { 5006 // We had an error; delete all of the subexpressions and return 5007 // the error. 5008 Object->Destroy(Context); 5009 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 5010 Args[ArgIdx]->Destroy(Context); 5011 return true; 5012 } 5013 5014 if (Best->Function == 0) { 5015 // Since there is no function declaration, this is one of the 5016 // surrogate candidates. Dig out the conversion function. 5017 CXXConversionDecl *Conv 5018 = cast<CXXConversionDecl>( 5019 Best->Conversions[0].UserDefined.ConversionFunction); 5020 5021 // We selected one of the surrogate functions that converts the 5022 // object parameter to a function pointer. Perform the conversion 5023 // on the object argument, then let ActOnCallExpr finish the job. 5024 5025 // Create an implicit member expr to refer to the conversion operator. 5026 // and then call it. 5027 CXXMemberCallExpr *CE = 5028 BuildCXXMemberCallExpr(Object, Conv); 5029 5030 return ActOnCallExpr(S, ExprArg(*this, CE), LParenLoc, 5031 MultiExprArg(*this, (ExprTy**)Args, NumArgs), 5032 CommaLocs, RParenLoc).release(); 5033 } 5034 5035 // We found an overloaded operator(). Build a CXXOperatorCallExpr 5036 // that calls this method, using Object for the implicit object 5037 // parameter and passing along the remaining arguments. 5038 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 5039 const FunctionProtoType *Proto = Method->getType()->getAs<FunctionProtoType>(); 5040 5041 unsigned NumArgsInProto = Proto->getNumArgs(); 5042 unsigned NumArgsToCheck = NumArgs; 5043 5044 // Build the full argument list for the method call (the 5045 // implicit object parameter is placed at the beginning of the 5046 // list). 5047 Expr **MethodArgs; 5048 if (NumArgs < NumArgsInProto) { 5049 NumArgsToCheck = NumArgsInProto; 5050 MethodArgs = new Expr*[NumArgsInProto + 1]; 5051 } else { 5052 MethodArgs = new Expr*[NumArgs + 1]; 5053 } 5054 MethodArgs[0] = Object; 5055 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 5056 MethodArgs[ArgIdx + 1] = Args[ArgIdx]; 5057 5058 Expr *NewFn = new (Context) DeclRefExpr(Method, Method->getType(), 5059 SourceLocation()); 5060 UsualUnaryConversions(NewFn); 5061 5062 // Once we've built TheCall, all of the expressions are properly 5063 // owned. 5064 QualType ResultTy = Method->getResultType().getNonReferenceType(); 5065 ExprOwningPtr<CXXOperatorCallExpr> 5066 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Call, NewFn, 5067 MethodArgs, NumArgs + 1, 5068 ResultTy, RParenLoc)); 5069 delete [] MethodArgs; 5070 5071 if (CheckCallReturnType(Method->getResultType(), LParenLoc, TheCall.get(), 5072 Method)) 5073 return true; 5074 5075 // We may have default arguments. If so, we need to allocate more 5076 // slots in the call for them. 5077 if (NumArgs < NumArgsInProto) 5078 TheCall->setNumArgs(Context, NumArgsInProto + 1); 5079 else if (NumArgs > NumArgsInProto) 5080 NumArgsToCheck = NumArgsInProto; 5081 5082 bool IsError = false; 5083 5084 // Initialize the implicit object parameter. 5085 IsError |= PerformObjectArgumentInitialization(Object, Method); 5086 TheCall->setArg(0, Object); 5087 5088 5089 // Check the argument types. 5090 for (unsigned i = 0; i != NumArgsToCheck; i++) { 5091 Expr *Arg; 5092 if (i < NumArgs) { 5093 Arg = Args[i]; 5094 5095 // Pass the argument. 5096 QualType ProtoArgType = Proto->getArgType(i); 5097 IsError |= PerformCopyInitialization(Arg, ProtoArgType, "passing"); 5098 } else { 5099 Arg = CXXDefaultArgExpr::Create(Context, Method->getParamDecl(i)); 5100 } 5101 5102 TheCall->setArg(i + 1, Arg); 5103 } 5104 5105 // If this is a variadic call, handle args passed through "...". 5106 if (Proto->isVariadic()) { 5107 // Promote the arguments (C99 6.5.2.2p7). 5108 for (unsigned i = NumArgsInProto; i != NumArgs; i++) { 5109 Expr *Arg = Args[i]; 5110 IsError |= DefaultVariadicArgumentPromotion(Arg, VariadicMethod); 5111 TheCall->setArg(i + 1, Arg); 5112 } 5113 } 5114 5115 if (IsError) return true; 5116 5117 if (CheckFunctionCall(Method, TheCall.get())) 5118 return true; 5119 5120 return MaybeBindToTemporary(TheCall.release()).release(); 5121} 5122 5123/// BuildOverloadedArrowExpr - Build a call to an overloaded @c operator-> 5124/// (if one exists), where @c Base is an expression of class type and 5125/// @c Member is the name of the member we're trying to find. 5126Sema::OwningExprResult 5127Sema::BuildOverloadedArrowExpr(Scope *S, ExprArg BaseIn, SourceLocation OpLoc) { 5128 Expr *Base = static_cast<Expr *>(BaseIn.get()); 5129 assert(Base->getType()->isRecordType() && "left-hand side must have class type"); 5130 5131 // C++ [over.ref]p1: 5132 // 5133 // [...] An expression x->m is interpreted as (x.operator->())->m 5134 // for a class object x of type T if T::operator->() exists and if 5135 // the operator is selected as the best match function by the 5136 // overload resolution mechanism (13.3). 5137 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Arrow); 5138 OverloadCandidateSet CandidateSet; 5139 const RecordType *BaseRecord = Base->getType()->getAs<RecordType>(); 5140 5141 LookupResult R; 5142 LookupQualifiedName(R, BaseRecord->getDecl(), OpName, LookupOrdinaryName); 5143 5144 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 5145 Oper != OperEnd; ++Oper) 5146 AddMethodCandidate(cast<CXXMethodDecl>(*Oper), Base, 0, 0, CandidateSet, 5147 /*SuppressUserConversions=*/false); 5148 5149 // Perform overload resolution. 5150 OverloadCandidateSet::iterator Best; 5151 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 5152 case OR_Success: 5153 // Overload resolution succeeded; we'll build the call below. 5154 break; 5155 5156 case OR_No_Viable_Function: 5157 if (CandidateSet.empty()) 5158 Diag(OpLoc, diag::err_typecheck_member_reference_arrow) 5159 << Base->getType() << Base->getSourceRange(); 5160 else 5161 Diag(OpLoc, diag::err_ovl_no_viable_oper) 5162 << "operator->" << Base->getSourceRange(); 5163 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 5164 return ExprError(); 5165 5166 case OR_Ambiguous: 5167 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 5168 << "->" << Base->getSourceRange(); 5169 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 5170 return ExprError(); 5171 5172 case OR_Deleted: 5173 Diag(OpLoc, diag::err_ovl_deleted_oper) 5174 << Best->Function->isDeleted() 5175 << "->" << Base->getSourceRange(); 5176 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 5177 return ExprError(); 5178 } 5179 5180 // Convert the object parameter. 5181 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 5182 if (PerformObjectArgumentInitialization(Base, Method)) 5183 return ExprError(); 5184 5185 // No concerns about early exits now. 5186 BaseIn.release(); 5187 5188 // Build the operator call. 5189 Expr *FnExpr = new (Context) DeclRefExpr(Method, Method->getType(), 5190 SourceLocation()); 5191 UsualUnaryConversions(FnExpr); 5192 5193 QualType ResultTy = Method->getResultType().getNonReferenceType(); 5194 ExprOwningPtr<CXXOperatorCallExpr> 5195 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Arrow, FnExpr, 5196 &Base, 1, ResultTy, OpLoc)); 5197 5198 if (CheckCallReturnType(Method->getResultType(), OpLoc, TheCall.get(), 5199 Method)) 5200 return ExprError(); 5201 return move(TheCall); 5202} 5203 5204/// FixOverloadedFunctionReference - E is an expression that refers to 5205/// a C++ overloaded function (possibly with some parentheses and 5206/// perhaps a '&' around it). We have resolved the overloaded function 5207/// to the function declaration Fn, so patch up the expression E to 5208/// refer (possibly indirectly) to Fn. 5209void Sema::FixOverloadedFunctionReference(Expr *E, FunctionDecl *Fn) { 5210 if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) { 5211 FixOverloadedFunctionReference(PE->getSubExpr(), Fn); 5212 E->setType(PE->getSubExpr()->getType()); 5213 } else if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(E)) { 5214 assert(UnOp->getOpcode() == UnaryOperator::AddrOf && 5215 "Can only take the address of an overloaded function"); 5216 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 5217 if (Method->isStatic()) { 5218 // Do nothing: static member functions aren't any different 5219 // from non-member functions. 5220 } else if (QualifiedDeclRefExpr *DRE 5221 = dyn_cast<QualifiedDeclRefExpr>(UnOp->getSubExpr())) { 5222 // We have taken the address of a pointer to member 5223 // function. Perform the computation here so that we get the 5224 // appropriate pointer to member type. 5225 DRE->setDecl(Fn); 5226 DRE->setType(Fn->getType()); 5227 QualType ClassType 5228 = Context.getTypeDeclType(cast<RecordDecl>(Method->getDeclContext())); 5229 E->setType(Context.getMemberPointerType(Fn->getType(), 5230 ClassType.getTypePtr())); 5231 return; 5232 } 5233 } 5234 FixOverloadedFunctionReference(UnOp->getSubExpr(), Fn); 5235 E->setType(Context.getPointerType(UnOp->getSubExpr()->getType())); 5236 } else if (DeclRefExpr *DR = dyn_cast<DeclRefExpr>(E)) { 5237 assert((isa<OverloadedFunctionDecl>(DR->getDecl()) || 5238 isa<FunctionTemplateDecl>(DR->getDecl())) && 5239 "Expected overloaded function or function template"); 5240 DR->setDecl(Fn); 5241 E->setType(Fn->getType()); 5242 } else if (MemberExpr *MemExpr = dyn_cast<MemberExpr>(E)) { 5243 MemExpr->setMemberDecl(Fn); 5244 E->setType(Fn->getType()); 5245 } else { 5246 assert(false && "Invalid reference to overloaded function"); 5247 } 5248} 5249 5250} // end namespace clang 5251