SemaOverload.cpp revision 65bdbfa6ca6b9a1170e052cc567d098d0f99cdae
1//===--- SemaOverload.cpp - C++ Overloading ---------------------*- C++ -*-===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This file provides Sema routines for C++ overloading. 11// 12//===----------------------------------------------------------------------===// 13 14#include "Sema.h" 15#include "Lookup.h" 16#include "clang/Basic/Diagnostic.h" 17#include "clang/Lex/Preprocessor.h" 18#include "clang/AST/ASTContext.h" 19#include "clang/AST/CXXInheritance.h" 20#include "clang/AST/Expr.h" 21#include "clang/AST/ExprCXX.h" 22#include "clang/AST/TypeOrdering.h" 23#include "clang/Basic/PartialDiagnostic.h" 24#include "llvm/ADT/SmallPtrSet.h" 25#include "llvm/ADT/STLExtras.h" 26#include "llvm/Support/Compiler.h" 27#include <algorithm> 28#include <cstdio> 29 30namespace clang { 31 32/// GetConversionCategory - Retrieve the implicit conversion 33/// category corresponding to the given implicit conversion kind. 34ImplicitConversionCategory 35GetConversionCategory(ImplicitConversionKind Kind) { 36 static const ImplicitConversionCategory 37 Category[(int)ICK_Num_Conversion_Kinds] = { 38 ICC_Identity, 39 ICC_Lvalue_Transformation, 40 ICC_Lvalue_Transformation, 41 ICC_Lvalue_Transformation, 42 ICC_Qualification_Adjustment, 43 ICC_Promotion, 44 ICC_Promotion, 45 ICC_Promotion, 46 ICC_Conversion, 47 ICC_Conversion, 48 ICC_Conversion, 49 ICC_Conversion, 50 ICC_Conversion, 51 ICC_Conversion, 52 ICC_Conversion, 53 ICC_Conversion, 54 ICC_Conversion, 55 ICC_Conversion 56 }; 57 return Category[(int)Kind]; 58} 59 60/// GetConversionRank - Retrieve the implicit conversion rank 61/// corresponding to the given implicit conversion kind. 62ImplicitConversionRank GetConversionRank(ImplicitConversionKind Kind) { 63 static const ImplicitConversionRank 64 Rank[(int)ICK_Num_Conversion_Kinds] = { 65 ICR_Exact_Match, 66 ICR_Exact_Match, 67 ICR_Exact_Match, 68 ICR_Exact_Match, 69 ICR_Exact_Match, 70 ICR_Promotion, 71 ICR_Promotion, 72 ICR_Promotion, 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 ICR_Conversion 83 }; 84 return Rank[(int)Kind]; 85} 86 87/// GetImplicitConversionName - Return the name of this kind of 88/// implicit conversion. 89const char* GetImplicitConversionName(ImplicitConversionKind Kind) { 90 static const char* Name[(int)ICK_Num_Conversion_Kinds] = { 91 "No conversion", 92 "Lvalue-to-rvalue", 93 "Array-to-pointer", 94 "Function-to-pointer", 95 "Qualification", 96 "Integral promotion", 97 "Floating point promotion", 98 "Complex promotion", 99 "Integral conversion", 100 "Floating conversion", 101 "Complex conversion", 102 "Floating-integral conversion", 103 "Complex-real conversion", 104 "Pointer conversion", 105 "Pointer-to-member conversion", 106 "Boolean conversion", 107 "Compatible-types conversion", 108 "Derived-to-base conversion" 109 }; 110 return Name[Kind]; 111} 112 113/// StandardConversionSequence - Set the standard conversion 114/// sequence to the identity conversion. 115void StandardConversionSequence::setAsIdentityConversion() { 116 First = ICK_Identity; 117 Second = ICK_Identity; 118 Third = ICK_Identity; 119 Deprecated = false; 120 ReferenceBinding = false; 121 DirectBinding = false; 122 RRefBinding = false; 123 CopyConstructor = 0; 124} 125 126/// getRank - Retrieve the rank of this standard conversion sequence 127/// (C++ 13.3.3.1.1p3). The rank is the largest rank of each of the 128/// implicit conversions. 129ImplicitConversionRank StandardConversionSequence::getRank() const { 130 ImplicitConversionRank Rank = ICR_Exact_Match; 131 if (GetConversionRank(First) > Rank) 132 Rank = GetConversionRank(First); 133 if (GetConversionRank(Second) > Rank) 134 Rank = GetConversionRank(Second); 135 if (GetConversionRank(Third) > Rank) 136 Rank = GetConversionRank(Third); 137 return Rank; 138} 139 140/// isPointerConversionToBool - Determines whether this conversion is 141/// a conversion of a pointer or pointer-to-member to bool. This is 142/// used as part of the ranking of standard conversion sequences 143/// (C++ 13.3.3.2p4). 144bool StandardConversionSequence::isPointerConversionToBool() const { 145 QualType FromType = QualType::getFromOpaquePtr(FromTypePtr); 146 QualType ToType = QualType::getFromOpaquePtr(ToTypePtr); 147 148 // Note that FromType has not necessarily been transformed by the 149 // array-to-pointer or function-to-pointer implicit conversions, so 150 // check for their presence as well as checking whether FromType is 151 // a pointer. 152 if (ToType->isBooleanType() && 153 (FromType->isPointerType() || FromType->isBlockPointerType() || 154 First == ICK_Array_To_Pointer || First == ICK_Function_To_Pointer)) 155 return true; 156 157 return false; 158} 159 160/// isPointerConversionToVoidPointer - Determines whether this 161/// conversion is a conversion of a pointer to a void pointer. This is 162/// used as part of the ranking of standard conversion sequences (C++ 163/// 13.3.3.2p4). 164bool 165StandardConversionSequence:: 166isPointerConversionToVoidPointer(ASTContext& Context) const { 167 QualType FromType = QualType::getFromOpaquePtr(FromTypePtr); 168 QualType ToType = QualType::getFromOpaquePtr(ToTypePtr); 169 170 // Note that FromType has not necessarily been transformed by the 171 // array-to-pointer implicit conversion, so check for its presence 172 // and redo the conversion to get a pointer. 173 if (First == ICK_Array_To_Pointer) 174 FromType = Context.getArrayDecayedType(FromType); 175 176 if (Second == ICK_Pointer_Conversion) 177 if (const PointerType* ToPtrType = ToType->getAs<PointerType>()) 178 return ToPtrType->getPointeeType()->isVoidType(); 179 180 return false; 181} 182 183/// DebugPrint - Print this standard conversion sequence to standard 184/// error. Useful for debugging overloading issues. 185void StandardConversionSequence::DebugPrint() const { 186 bool PrintedSomething = false; 187 if (First != ICK_Identity) { 188 fprintf(stderr, "%s", GetImplicitConversionName(First)); 189 PrintedSomething = true; 190 } 191 192 if (Second != ICK_Identity) { 193 if (PrintedSomething) { 194 fprintf(stderr, " -> "); 195 } 196 fprintf(stderr, "%s", GetImplicitConversionName(Second)); 197 198 if (CopyConstructor) { 199 fprintf(stderr, " (by copy constructor)"); 200 } else if (DirectBinding) { 201 fprintf(stderr, " (direct reference binding)"); 202 } else if (ReferenceBinding) { 203 fprintf(stderr, " (reference binding)"); 204 } 205 PrintedSomething = true; 206 } 207 208 if (Third != ICK_Identity) { 209 if (PrintedSomething) { 210 fprintf(stderr, " -> "); 211 } 212 fprintf(stderr, "%s", GetImplicitConversionName(Third)); 213 PrintedSomething = true; 214 } 215 216 if (!PrintedSomething) { 217 fprintf(stderr, "No conversions required"); 218 } 219} 220 221/// DebugPrint - Print this user-defined conversion sequence to standard 222/// error. Useful for debugging overloading issues. 223void UserDefinedConversionSequence::DebugPrint() const { 224 if (Before.First || Before.Second || Before.Third) { 225 Before.DebugPrint(); 226 fprintf(stderr, " -> "); 227 } 228 fprintf(stderr, "'%s'", ConversionFunction->getNameAsString().c_str()); 229 if (After.First || After.Second || After.Third) { 230 fprintf(stderr, " -> "); 231 After.DebugPrint(); 232 } 233} 234 235/// DebugPrint - Print this implicit conversion sequence to standard 236/// error. Useful for debugging overloading issues. 237void ImplicitConversionSequence::DebugPrint() const { 238 switch (ConversionKind) { 239 case StandardConversion: 240 fprintf(stderr, "Standard conversion: "); 241 Standard.DebugPrint(); 242 break; 243 case UserDefinedConversion: 244 fprintf(stderr, "User-defined conversion: "); 245 UserDefined.DebugPrint(); 246 break; 247 case EllipsisConversion: 248 fprintf(stderr, "Ellipsis conversion"); 249 break; 250 case BadConversion: 251 fprintf(stderr, "Bad conversion"); 252 break; 253 } 254 255 fprintf(stderr, "\n"); 256} 257 258// IsOverload - Determine whether the given New declaration is an 259// overload of the Old declaration. This routine returns false if New 260// and Old cannot be overloaded, e.g., if they are functions with the 261// same signature (C++ 1.3.10) or if the Old declaration isn't a 262// function (or overload set). When it does return false and Old is an 263// OverloadedFunctionDecl, MatchedDecl will be set to point to the 264// FunctionDecl that New cannot be overloaded with. 265// 266// Example: Given the following input: 267// 268// void f(int, float); // #1 269// void f(int, int); // #2 270// int f(int, int); // #3 271// 272// When we process #1, there is no previous declaration of "f", 273// so IsOverload will not be used. 274// 275// When we process #2, Old is a FunctionDecl for #1. By comparing the 276// parameter types, we see that #1 and #2 are overloaded (since they 277// have different signatures), so this routine returns false; 278// MatchedDecl is unchanged. 279// 280// When we process #3, Old is an OverloadedFunctionDecl containing #1 281// and #2. We compare the signatures of #3 to #1 (they're overloaded, 282// so we do nothing) and then #3 to #2. Since the signatures of #3 and 283// #2 are identical (return types of functions are not part of the 284// signature), IsOverload returns false and MatchedDecl will be set to 285// point to the FunctionDecl for #2. 286bool 287Sema::IsOverload(FunctionDecl *New, Decl* OldD, 288 OverloadedFunctionDecl::function_iterator& MatchedDecl) { 289 if (OverloadedFunctionDecl* Ovl = dyn_cast<OverloadedFunctionDecl>(OldD)) { 290 // Is this new function an overload of every function in the 291 // overload set? 292 OverloadedFunctionDecl::function_iterator Func = Ovl->function_begin(), 293 FuncEnd = Ovl->function_end(); 294 for (; Func != FuncEnd; ++Func) { 295 if (!IsOverload(New, *Func, MatchedDecl)) { 296 MatchedDecl = Func; 297 return false; 298 } 299 } 300 301 // This function overloads every function in the overload set. 302 return true; 303 } else if (FunctionTemplateDecl *Old = dyn_cast<FunctionTemplateDecl>(OldD)) 304 return IsOverload(New, Old->getTemplatedDecl(), MatchedDecl); 305 else if (FunctionDecl* Old = dyn_cast<FunctionDecl>(OldD)) { 306 FunctionTemplateDecl *OldTemplate = Old->getDescribedFunctionTemplate(); 307 FunctionTemplateDecl *NewTemplate = New->getDescribedFunctionTemplate(); 308 309 // C++ [temp.fct]p2: 310 // A function template can be overloaded with other function templates 311 // and with normal (non-template) functions. 312 if ((OldTemplate == 0) != (NewTemplate == 0)) 313 return true; 314 315 // Is the function New an overload of the function Old? 316 QualType OldQType = Context.getCanonicalType(Old->getType()); 317 QualType NewQType = Context.getCanonicalType(New->getType()); 318 319 // Compare the signatures (C++ 1.3.10) of the two functions to 320 // determine whether they are overloads. If we find any mismatch 321 // in the signature, they are overloads. 322 323 // If either of these functions is a K&R-style function (no 324 // prototype), then we consider them to have matching signatures. 325 if (isa<FunctionNoProtoType>(OldQType.getTypePtr()) || 326 isa<FunctionNoProtoType>(NewQType.getTypePtr())) 327 return false; 328 329 FunctionProtoType* OldType = cast<FunctionProtoType>(OldQType); 330 FunctionProtoType* NewType = cast<FunctionProtoType>(NewQType); 331 332 // The signature of a function includes the types of its 333 // parameters (C++ 1.3.10), which includes the presence or absence 334 // of the ellipsis; see C++ DR 357). 335 if (OldQType != NewQType && 336 (OldType->getNumArgs() != NewType->getNumArgs() || 337 OldType->isVariadic() != NewType->isVariadic() || 338 !std::equal(OldType->arg_type_begin(), OldType->arg_type_end(), 339 NewType->arg_type_begin()))) 340 return true; 341 342 // C++ [temp.over.link]p4: 343 // The signature of a function template consists of its function 344 // signature, its return type and its template parameter list. The names 345 // of the template parameters are significant only for establishing the 346 // relationship between the template parameters and the rest of the 347 // signature. 348 // 349 // We check the return type and template parameter lists for function 350 // templates first; the remaining checks follow. 351 if (NewTemplate && 352 (!TemplateParameterListsAreEqual(NewTemplate->getTemplateParameters(), 353 OldTemplate->getTemplateParameters(), 354 false, TPL_TemplateMatch) || 355 OldType->getResultType() != NewType->getResultType())) 356 return true; 357 358 // If the function is a class member, its signature includes the 359 // cv-qualifiers (if any) on the function itself. 360 // 361 // As part of this, also check whether one of the member functions 362 // is static, in which case they are not overloads (C++ 363 // 13.1p2). While not part of the definition of the signature, 364 // this check is important to determine whether these functions 365 // can be overloaded. 366 CXXMethodDecl* OldMethod = dyn_cast<CXXMethodDecl>(Old); 367 CXXMethodDecl* NewMethod = dyn_cast<CXXMethodDecl>(New); 368 if (OldMethod && NewMethod && 369 !OldMethod->isStatic() && !NewMethod->isStatic() && 370 OldMethod->getTypeQualifiers() != NewMethod->getTypeQualifiers()) 371 return true; 372 373 // The signatures match; this is not an overload. 374 return false; 375 } else { 376 // (C++ 13p1): 377 // Only function declarations can be overloaded; object and type 378 // declarations cannot be overloaded. 379 return false; 380 } 381} 382 383/// TryImplicitConversion - Attempt to perform an implicit conversion 384/// from the given expression (Expr) to the given type (ToType). This 385/// function returns an implicit conversion sequence that can be used 386/// to perform the initialization. Given 387/// 388/// void f(float f); 389/// void g(int i) { f(i); } 390/// 391/// this routine would produce an implicit conversion sequence to 392/// describe the initialization of f from i, which will be a standard 393/// conversion sequence containing an lvalue-to-rvalue conversion (C++ 394/// 4.1) followed by a floating-integral conversion (C++ 4.9). 395// 396/// Note that this routine only determines how the conversion can be 397/// performed; it does not actually perform the conversion. As such, 398/// it will not produce any diagnostics if no conversion is available, 399/// but will instead return an implicit conversion sequence of kind 400/// "BadConversion". 401/// 402/// If @p SuppressUserConversions, then user-defined conversions are 403/// not permitted. 404/// If @p AllowExplicit, then explicit user-defined conversions are 405/// permitted. 406/// If @p ForceRValue, then overloading is performed as if From was an rvalue, 407/// no matter its actual lvalueness. 408/// If @p UserCast, the implicit conversion is being done for a user-specified 409/// cast. 410ImplicitConversionSequence 411Sema::TryImplicitConversion(Expr* From, QualType ToType, 412 bool SuppressUserConversions, 413 bool AllowExplicit, bool ForceRValue, 414 bool InOverloadResolution, 415 bool UserCast) { 416 ImplicitConversionSequence ICS; 417 OverloadCandidateSet Conversions; 418 OverloadingResult UserDefResult = OR_Success; 419 if (IsStandardConversion(From, ToType, InOverloadResolution, ICS.Standard)) 420 ICS.ConversionKind = ImplicitConversionSequence::StandardConversion; 421 else if (getLangOptions().CPlusPlus && 422 (UserDefResult = IsUserDefinedConversion(From, ToType, 423 ICS.UserDefined, 424 Conversions, 425 !SuppressUserConversions, AllowExplicit, 426 ForceRValue, UserCast)) == OR_Success) { 427 ICS.ConversionKind = ImplicitConversionSequence::UserDefinedConversion; 428 // C++ [over.ics.user]p4: 429 // A conversion of an expression of class type to the same class 430 // type is given Exact Match rank, and a conversion of an 431 // expression of class type to a base class of that type is 432 // given Conversion rank, in spite of the fact that a copy 433 // constructor (i.e., a user-defined conversion function) is 434 // called for those cases. 435 if (CXXConstructorDecl *Constructor 436 = dyn_cast<CXXConstructorDecl>(ICS.UserDefined.ConversionFunction)) { 437 QualType FromCanon 438 = Context.getCanonicalType(From->getType().getUnqualifiedType()); 439 QualType ToCanon = Context.getCanonicalType(ToType).getUnqualifiedType(); 440 if (FromCanon == ToCanon || IsDerivedFrom(FromCanon, ToCanon)) { 441 // Turn this into a "standard" conversion sequence, so that it 442 // gets ranked with standard conversion sequences. 443 ICS.ConversionKind = ImplicitConversionSequence::StandardConversion; 444 ICS.Standard.setAsIdentityConversion(); 445 ICS.Standard.FromTypePtr = From->getType().getAsOpaquePtr(); 446 ICS.Standard.ToTypePtr = ToType.getAsOpaquePtr(); 447 ICS.Standard.CopyConstructor = Constructor; 448 if (ToCanon != FromCanon) 449 ICS.Standard.Second = ICK_Derived_To_Base; 450 } 451 } 452 453 // C++ [over.best.ics]p4: 454 // However, when considering the argument of a user-defined 455 // conversion function that is a candidate by 13.3.1.3 when 456 // invoked for the copying of the temporary in the second step 457 // of a class copy-initialization, or by 13.3.1.4, 13.3.1.5, or 458 // 13.3.1.6 in all cases, only standard conversion sequences and 459 // ellipsis conversion sequences are allowed. 460 if (SuppressUserConversions && 461 ICS.ConversionKind == ImplicitConversionSequence::UserDefinedConversion) 462 ICS.ConversionKind = ImplicitConversionSequence::BadConversion; 463 } else { 464 ICS.ConversionKind = ImplicitConversionSequence::BadConversion; 465 if (UserDefResult == OR_Ambiguous) { 466 for (OverloadCandidateSet::iterator Cand = Conversions.begin(); 467 Cand != Conversions.end(); ++Cand) 468 if (Cand->Viable) 469 ICS.ConversionFunctionSet.push_back(Cand->Function); 470 } 471 } 472 473 return ICS; 474} 475 476/// IsStandardConversion - Determines whether there is a standard 477/// conversion sequence (C++ [conv], C++ [over.ics.scs]) from the 478/// expression From to the type ToType. Standard conversion sequences 479/// only consider non-class types; for conversions that involve class 480/// types, use TryImplicitConversion. If a conversion exists, SCS will 481/// contain the standard conversion sequence required to perform this 482/// conversion and this routine will return true. Otherwise, this 483/// routine will return false and the value of SCS is unspecified. 484bool 485Sema::IsStandardConversion(Expr* From, QualType ToType, 486 bool InOverloadResolution, 487 StandardConversionSequence &SCS) { 488 QualType FromType = From->getType(); 489 490 // Standard conversions (C++ [conv]) 491 SCS.setAsIdentityConversion(); 492 SCS.Deprecated = false; 493 SCS.IncompatibleObjC = false; 494 SCS.FromTypePtr = FromType.getAsOpaquePtr(); 495 SCS.CopyConstructor = 0; 496 497 // There are no standard conversions for class types in C++, so 498 // abort early. When overloading in C, however, we do permit 499 if (FromType->isRecordType() || ToType->isRecordType()) { 500 if (getLangOptions().CPlusPlus) 501 return false; 502 503 // When we're overloading in C, we allow, as standard conversions, 504 } 505 506 // The first conversion can be an lvalue-to-rvalue conversion, 507 // array-to-pointer conversion, or function-to-pointer conversion 508 // (C++ 4p1). 509 510 // Lvalue-to-rvalue conversion (C++ 4.1): 511 // An lvalue (3.10) of a non-function, non-array type T can be 512 // converted to an rvalue. 513 Expr::isLvalueResult argIsLvalue = From->isLvalue(Context); 514 if (argIsLvalue == Expr::LV_Valid && 515 !FromType->isFunctionType() && !FromType->isArrayType() && 516 Context.getCanonicalType(FromType) != Context.OverloadTy) { 517 SCS.First = ICK_Lvalue_To_Rvalue; 518 519 // If T is a non-class type, the type of the rvalue is the 520 // cv-unqualified version of T. Otherwise, the type of the rvalue 521 // is T (C++ 4.1p1). C++ can't get here with class types; in C, we 522 // just strip the qualifiers because they don't matter. 523 FromType = FromType.getUnqualifiedType(); 524 } else if (FromType->isArrayType()) { 525 // Array-to-pointer conversion (C++ 4.2) 526 SCS.First = ICK_Array_To_Pointer; 527 528 // An lvalue or rvalue of type "array of N T" or "array of unknown 529 // bound of T" can be converted to an rvalue of type "pointer to 530 // T" (C++ 4.2p1). 531 FromType = Context.getArrayDecayedType(FromType); 532 533 if (IsStringLiteralToNonConstPointerConversion(From, ToType)) { 534 // This conversion is deprecated. (C++ D.4). 535 SCS.Deprecated = true; 536 537 // For the purpose of ranking in overload resolution 538 // (13.3.3.1.1), this conversion is considered an 539 // array-to-pointer conversion followed by a qualification 540 // conversion (4.4). (C++ 4.2p2) 541 SCS.Second = ICK_Identity; 542 SCS.Third = ICK_Qualification; 543 SCS.ToTypePtr = ToType.getAsOpaquePtr(); 544 return true; 545 } 546 } else if (FromType->isFunctionType() && argIsLvalue == Expr::LV_Valid) { 547 // Function-to-pointer conversion (C++ 4.3). 548 SCS.First = ICK_Function_To_Pointer; 549 550 // An lvalue of function type T can be converted to an rvalue of 551 // type "pointer to T." The result is a pointer to the 552 // function. (C++ 4.3p1). 553 FromType = Context.getPointerType(FromType); 554 } else if (FunctionDecl *Fn 555 = ResolveAddressOfOverloadedFunction(From, ToType, false)) { 556 // Address of overloaded function (C++ [over.over]). 557 SCS.First = ICK_Function_To_Pointer; 558 559 // We were able to resolve the address of the overloaded function, 560 // so we can convert to the type of that function. 561 FromType = Fn->getType(); 562 if (ToType->isLValueReferenceType()) 563 FromType = Context.getLValueReferenceType(FromType); 564 else if (ToType->isRValueReferenceType()) 565 FromType = Context.getRValueReferenceType(FromType); 566 else if (ToType->isMemberPointerType()) { 567 // Resolve address only succeeds if both sides are member pointers, 568 // but it doesn't have to be the same class. See DR 247. 569 // Note that this means that the type of &Derived::fn can be 570 // Ret (Base::*)(Args) if the fn overload actually found is from the 571 // base class, even if it was brought into the derived class via a 572 // using declaration. The standard isn't clear on this issue at all. 573 CXXMethodDecl *M = cast<CXXMethodDecl>(Fn); 574 FromType = Context.getMemberPointerType(FromType, 575 Context.getTypeDeclType(M->getParent()).getTypePtr()); 576 } else 577 FromType = Context.getPointerType(FromType); 578 } else { 579 // We don't require any conversions for the first step. 580 SCS.First = ICK_Identity; 581 } 582 583 // The second conversion can be an integral promotion, floating 584 // point promotion, integral conversion, floating point conversion, 585 // floating-integral conversion, pointer conversion, 586 // pointer-to-member conversion, or boolean conversion (C++ 4p1). 587 // For overloading in C, this can also be a "compatible-type" 588 // conversion. 589 bool IncompatibleObjC = false; 590 if (Context.hasSameUnqualifiedType(FromType, ToType)) { 591 // The unqualified versions of the types are the same: there's no 592 // conversion to do. 593 SCS.Second = ICK_Identity; 594 } else if (IsIntegralPromotion(From, FromType, ToType)) { 595 // Integral promotion (C++ 4.5). 596 SCS.Second = ICK_Integral_Promotion; 597 FromType = ToType.getUnqualifiedType(); 598 } else if (IsFloatingPointPromotion(FromType, ToType)) { 599 // Floating point promotion (C++ 4.6). 600 SCS.Second = ICK_Floating_Promotion; 601 FromType = ToType.getUnqualifiedType(); 602 } else if (IsComplexPromotion(FromType, ToType)) { 603 // Complex promotion (Clang extension) 604 SCS.Second = ICK_Complex_Promotion; 605 FromType = ToType.getUnqualifiedType(); 606 } else if ((FromType->isIntegralType() || FromType->isEnumeralType()) && 607 (ToType->isIntegralType() && !ToType->isEnumeralType())) { 608 // Integral conversions (C++ 4.7). 609 // FIXME: isIntegralType shouldn't be true for enums in C++. 610 SCS.Second = ICK_Integral_Conversion; 611 FromType = ToType.getUnqualifiedType(); 612 } else if (FromType->isFloatingType() && ToType->isFloatingType()) { 613 // Floating point conversions (C++ 4.8). 614 SCS.Second = ICK_Floating_Conversion; 615 FromType = ToType.getUnqualifiedType(); 616 } else if (FromType->isComplexType() && ToType->isComplexType()) { 617 // Complex conversions (C99 6.3.1.6) 618 SCS.Second = ICK_Complex_Conversion; 619 FromType = ToType.getUnqualifiedType(); 620 } else if ((FromType->isFloatingType() && 621 ToType->isIntegralType() && (!ToType->isBooleanType() && 622 !ToType->isEnumeralType())) || 623 ((FromType->isIntegralType() || FromType->isEnumeralType()) && 624 ToType->isFloatingType())) { 625 // Floating-integral conversions (C++ 4.9). 626 // FIXME: isIntegralType shouldn't be true for enums in C++. 627 SCS.Second = ICK_Floating_Integral; 628 FromType = ToType.getUnqualifiedType(); 629 } else if ((FromType->isComplexType() && ToType->isArithmeticType()) || 630 (ToType->isComplexType() && FromType->isArithmeticType())) { 631 // Complex-real conversions (C99 6.3.1.7) 632 SCS.Second = ICK_Complex_Real; 633 FromType = ToType.getUnqualifiedType(); 634 } else if (IsPointerConversion(From, FromType, ToType, InOverloadResolution, 635 FromType, IncompatibleObjC)) { 636 // Pointer conversions (C++ 4.10). 637 SCS.Second = ICK_Pointer_Conversion; 638 SCS.IncompatibleObjC = IncompatibleObjC; 639 } else if (IsMemberPointerConversion(From, FromType, ToType, 640 InOverloadResolution, FromType)) { 641 // Pointer to member conversions (4.11). 642 SCS.Second = ICK_Pointer_Member; 643 } else if (ToType->isBooleanType() && 644 (FromType->isArithmeticType() || 645 FromType->isEnumeralType() || 646 FromType->isPointerType() || 647 FromType->isBlockPointerType() || 648 FromType->isMemberPointerType() || 649 FromType->isNullPtrType())) { 650 // Boolean conversions (C++ 4.12). 651 SCS.Second = ICK_Boolean_Conversion; 652 FromType = Context.BoolTy; 653 } else if (!getLangOptions().CPlusPlus && 654 Context.typesAreCompatible(ToType, FromType)) { 655 // Compatible conversions (Clang extension for C function overloading) 656 SCS.Second = ICK_Compatible_Conversion; 657 } else { 658 // No second conversion required. 659 SCS.Second = ICK_Identity; 660 } 661 662 QualType CanonFrom; 663 QualType CanonTo; 664 // The third conversion can be a qualification conversion (C++ 4p1). 665 if (IsQualificationConversion(FromType, ToType)) { 666 SCS.Third = ICK_Qualification; 667 FromType = ToType; 668 CanonFrom = Context.getCanonicalType(FromType); 669 CanonTo = Context.getCanonicalType(ToType); 670 } else { 671 // No conversion required 672 SCS.Third = ICK_Identity; 673 674 // C++ [over.best.ics]p6: 675 // [...] Any difference in top-level cv-qualification is 676 // subsumed by the initialization itself and does not constitute 677 // a conversion. [...] 678 CanonFrom = Context.getCanonicalType(FromType); 679 CanonTo = Context.getCanonicalType(ToType); 680 if (CanonFrom.getLocalUnqualifiedType() 681 == CanonTo.getLocalUnqualifiedType() && 682 CanonFrom.getLocalCVRQualifiers() != CanonTo.getLocalCVRQualifiers()) { 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.hasSameUnqualifiedType(ToType, PromoteTypes[Idx]); 760 } 761 } 762 } 763 764 // An rvalue for an integral bit-field (9.6) can be converted to an 765 // rvalue of type int if int can represent all the values of the 766 // bit-field; otherwise, it can be converted to unsigned int if 767 // unsigned int can represent all the values of the bit-field. If 768 // the bit-field is larger yet, no integral promotion applies to 769 // it. If the bit-field has an enumerated type, it is treated as any 770 // other value of that type for promotion purposes (C++ 4.5p3). 771 // FIXME: We should delay checking of bit-fields until we actually perform the 772 // conversion. 773 using llvm::APSInt; 774 if (From) 775 if (FieldDecl *MemberDecl = From->getBitField()) { 776 APSInt BitWidth; 777 if (FromType->isIntegralType() && !FromType->isEnumeralType() && 778 MemberDecl->getBitWidth()->isIntegerConstantExpr(BitWidth, Context)) { 779 APSInt ToSize(BitWidth.getBitWidth(), BitWidth.isUnsigned()); 780 ToSize = Context.getTypeSize(ToType); 781 782 // Are we promoting to an int from a bitfield that fits in an int? 783 if (BitWidth < ToSize || 784 (FromType->isSignedIntegerType() && BitWidth <= ToSize)) { 785 return To->getKind() == BuiltinType::Int; 786 } 787 788 // Are we promoting to an unsigned int from an unsigned bitfield 789 // that fits into an unsigned int? 790 if (FromType->isUnsignedIntegerType() && BitWidth <= ToSize) { 791 return To->getKind() == BuiltinType::UInt; 792 } 793 794 return false; 795 } 796 } 797 798 // An rvalue of type bool can be converted to an rvalue of type int, 799 // with false becoming zero and true becoming one (C++ 4.5p4). 800 if (FromType->isBooleanType() && To->getKind() == BuiltinType::Int) { 801 return true; 802 } 803 804 return false; 805} 806 807/// IsFloatingPointPromotion - Determines whether the conversion from 808/// FromType to ToType is a floating point promotion (C++ 4.6). If so, 809/// returns true and sets PromotedType to the promoted type. 810bool Sema::IsFloatingPointPromotion(QualType FromType, QualType ToType) { 811 /// An rvalue of type float can be converted to an rvalue of type 812 /// double. (C++ 4.6p1). 813 if (const BuiltinType *FromBuiltin = FromType->getAs<BuiltinType>()) 814 if (const BuiltinType *ToBuiltin = ToType->getAs<BuiltinType>()) { 815 if (FromBuiltin->getKind() == BuiltinType::Float && 816 ToBuiltin->getKind() == BuiltinType::Double) 817 return true; 818 819 // C99 6.3.1.5p1: 820 // When a float is promoted to double or long double, or a 821 // double is promoted to long double [...]. 822 if (!getLangOptions().CPlusPlus && 823 (FromBuiltin->getKind() == BuiltinType::Float || 824 FromBuiltin->getKind() == BuiltinType::Double) && 825 (ToBuiltin->getKind() == BuiltinType::LongDouble)) 826 return true; 827 } 828 829 return false; 830} 831 832/// \brief Determine if a conversion is a complex promotion. 833/// 834/// A complex promotion is defined as a complex -> complex conversion 835/// where the conversion between the underlying real types is a 836/// floating-point or integral promotion. 837bool Sema::IsComplexPromotion(QualType FromType, QualType ToType) { 838 const ComplexType *FromComplex = FromType->getAs<ComplexType>(); 839 if (!FromComplex) 840 return false; 841 842 const ComplexType *ToComplex = ToType->getAs<ComplexType>(); 843 if (!ToComplex) 844 return false; 845 846 return IsFloatingPointPromotion(FromComplex->getElementType(), 847 ToComplex->getElementType()) || 848 IsIntegralPromotion(0, FromComplex->getElementType(), 849 ToComplex->getElementType()); 850} 851 852/// BuildSimilarlyQualifiedPointerType - In a pointer conversion from 853/// the pointer type FromPtr to a pointer to type ToPointee, with the 854/// same type qualifiers as FromPtr has on its pointee type. ToType, 855/// if non-empty, will be a pointer to ToType that may or may not have 856/// the right set of qualifiers on its pointee. 857static QualType 858BuildSimilarlyQualifiedPointerType(const PointerType *FromPtr, 859 QualType ToPointee, QualType ToType, 860 ASTContext &Context) { 861 QualType CanonFromPointee = Context.getCanonicalType(FromPtr->getPointeeType()); 862 QualType CanonToPointee = Context.getCanonicalType(ToPointee); 863 Qualifiers Quals = CanonFromPointee.getQualifiers(); 864 865 // Exact qualifier match -> return the pointer type we're converting to. 866 if (CanonToPointee.getLocalQualifiers() == Quals) { 867 // ToType is exactly what we need. Return it. 868 if (!ToType.isNull()) 869 return ToType; 870 871 // Build a pointer to ToPointee. It has the right qualifiers 872 // already. 873 return Context.getPointerType(ToPointee); 874 } 875 876 // Just build a canonical type that has the right qualifiers. 877 return Context.getPointerType( 878 Context.getQualifiedType(CanonToPointee.getLocalUnqualifiedType(), 879 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 !RequireCompleteType(From->getLocStart(), FromPointeeType, PDiag()) && 1003 IsDerivedFrom(FromPointeeType, ToPointeeType)) { 1004 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1005 ToPointeeType, 1006 ToType, Context); 1007 return true; 1008 } 1009 1010 return false; 1011} 1012 1013/// isObjCPointerConversion - Determines whether this is an 1014/// Objective-C pointer conversion. Subroutine of IsPointerConversion, 1015/// with the same arguments and return values. 1016bool Sema::isObjCPointerConversion(QualType FromType, QualType ToType, 1017 QualType& ConvertedType, 1018 bool &IncompatibleObjC) { 1019 if (!getLangOptions().ObjC1) 1020 return false; 1021 1022 // First, we handle all conversions on ObjC object pointer types. 1023 const ObjCObjectPointerType* ToObjCPtr = ToType->getAs<ObjCObjectPointerType>(); 1024 const ObjCObjectPointerType *FromObjCPtr = 1025 FromType->getAs<ObjCObjectPointerType>(); 1026 1027 if (ToObjCPtr && FromObjCPtr) { 1028 // Objective C++: We're able to convert between "id" or "Class" and a 1029 // pointer to any interface (in both directions). 1030 if (ToObjCPtr->isObjCBuiltinType() && FromObjCPtr->isObjCBuiltinType()) { 1031 ConvertedType = ToType; 1032 return true; 1033 } 1034 // Conversions with Objective-C's id<...>. 1035 if ((FromObjCPtr->isObjCQualifiedIdType() || 1036 ToObjCPtr->isObjCQualifiedIdType()) && 1037 Context.ObjCQualifiedIdTypesAreCompatible(ToType, FromType, 1038 /*compare=*/false)) { 1039 ConvertedType = ToType; 1040 return true; 1041 } 1042 // Objective C++: We're able to convert from a pointer to an 1043 // interface to a pointer to a different interface. 1044 if (Context.canAssignObjCInterfaces(ToObjCPtr, FromObjCPtr)) { 1045 ConvertedType = ToType; 1046 return true; 1047 } 1048 1049 if (Context.canAssignObjCInterfaces(FromObjCPtr, ToObjCPtr)) { 1050 // Okay: this is some kind of implicit downcast of Objective-C 1051 // interfaces, which is permitted. However, we're going to 1052 // complain about it. 1053 IncompatibleObjC = true; 1054 ConvertedType = FromType; 1055 return true; 1056 } 1057 } 1058 // Beyond this point, both types need to be C pointers or block pointers. 1059 QualType ToPointeeType; 1060 if (const PointerType *ToCPtr = ToType->getAs<PointerType>()) 1061 ToPointeeType = ToCPtr->getPointeeType(); 1062 else if (const BlockPointerType *ToBlockPtr = ToType->getAs<BlockPointerType>()) 1063 ToPointeeType = ToBlockPtr->getPointeeType(); 1064 else 1065 return false; 1066 1067 QualType FromPointeeType; 1068 if (const PointerType *FromCPtr = FromType->getAs<PointerType>()) 1069 FromPointeeType = FromCPtr->getPointeeType(); 1070 else if (const BlockPointerType *FromBlockPtr = FromType->getAs<BlockPointerType>()) 1071 FromPointeeType = FromBlockPtr->getPointeeType(); 1072 else 1073 return false; 1074 1075 // If we have pointers to pointers, recursively check whether this 1076 // is an Objective-C conversion. 1077 if (FromPointeeType->isPointerType() && ToPointeeType->isPointerType() && 1078 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, 1079 IncompatibleObjC)) { 1080 // We always complain about this conversion. 1081 IncompatibleObjC = true; 1082 ConvertedType = ToType; 1083 return true; 1084 } 1085 // If we have pointers to functions or blocks, check whether the only 1086 // differences in the argument and result types are in Objective-C 1087 // pointer conversions. If so, we permit the conversion (but 1088 // complain about it). 1089 const FunctionProtoType *FromFunctionType 1090 = FromPointeeType->getAs<FunctionProtoType>(); 1091 const FunctionProtoType *ToFunctionType 1092 = ToPointeeType->getAs<FunctionProtoType>(); 1093 if (FromFunctionType && ToFunctionType) { 1094 // If the function types are exactly the same, this isn't an 1095 // Objective-C pointer conversion. 1096 if (Context.getCanonicalType(FromPointeeType) 1097 == Context.getCanonicalType(ToPointeeType)) 1098 return false; 1099 1100 // Perform the quick checks that will tell us whether these 1101 // function types are obviously different. 1102 if (FromFunctionType->getNumArgs() != ToFunctionType->getNumArgs() || 1103 FromFunctionType->isVariadic() != ToFunctionType->isVariadic() || 1104 FromFunctionType->getTypeQuals() != ToFunctionType->getTypeQuals()) 1105 return false; 1106 1107 bool HasObjCConversion = false; 1108 if (Context.getCanonicalType(FromFunctionType->getResultType()) 1109 == Context.getCanonicalType(ToFunctionType->getResultType())) { 1110 // Okay, the types match exactly. Nothing to do. 1111 } else if (isObjCPointerConversion(FromFunctionType->getResultType(), 1112 ToFunctionType->getResultType(), 1113 ConvertedType, IncompatibleObjC)) { 1114 // Okay, we have an Objective-C pointer conversion. 1115 HasObjCConversion = true; 1116 } else { 1117 // Function types are too different. Abort. 1118 return false; 1119 } 1120 1121 // Check argument types. 1122 for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumArgs(); 1123 ArgIdx != NumArgs; ++ArgIdx) { 1124 QualType FromArgType = FromFunctionType->getArgType(ArgIdx); 1125 QualType ToArgType = ToFunctionType->getArgType(ArgIdx); 1126 if (Context.getCanonicalType(FromArgType) 1127 == Context.getCanonicalType(ToArgType)) { 1128 // Okay, the types match exactly. Nothing to do. 1129 } else if (isObjCPointerConversion(FromArgType, ToArgType, 1130 ConvertedType, IncompatibleObjC)) { 1131 // Okay, we have an Objective-C pointer conversion. 1132 HasObjCConversion = true; 1133 } else { 1134 // Argument types are too different. Abort. 1135 return false; 1136 } 1137 } 1138 1139 if (HasObjCConversion) { 1140 // We had an Objective-C conversion. Allow this pointer 1141 // conversion, but complain about it. 1142 ConvertedType = ToType; 1143 IncompatibleObjC = true; 1144 return true; 1145 } 1146 } 1147 1148 return false; 1149} 1150 1151/// CheckPointerConversion - Check the pointer conversion from the 1152/// expression From to the type ToType. This routine checks for 1153/// ambiguous or inaccessible derived-to-base pointer 1154/// conversions for which IsPointerConversion has already returned 1155/// true. It returns true and produces a diagnostic if there was an 1156/// error, or returns false otherwise. 1157bool Sema::CheckPointerConversion(Expr *From, QualType ToType, 1158 CastExpr::CastKind &Kind, 1159 bool IgnoreBaseAccess) { 1160 QualType FromType = From->getType(); 1161 1162 if (const PointerType *FromPtrType = FromType->getAs<PointerType>()) 1163 if (const PointerType *ToPtrType = ToType->getAs<PointerType>()) { 1164 QualType FromPointeeType = FromPtrType->getPointeeType(), 1165 ToPointeeType = ToPtrType->getPointeeType(); 1166 1167 if (FromPointeeType->isRecordType() && 1168 ToPointeeType->isRecordType()) { 1169 // We must have a derived-to-base conversion. Check an 1170 // ambiguous or inaccessible conversion. 1171 if (CheckDerivedToBaseConversion(FromPointeeType, ToPointeeType, 1172 From->getExprLoc(), 1173 From->getSourceRange(), 1174 IgnoreBaseAccess)) 1175 return true; 1176 1177 // The conversion was successful. 1178 Kind = CastExpr::CK_DerivedToBase; 1179 } 1180 } 1181 if (const ObjCObjectPointerType *FromPtrType = 1182 FromType->getAs<ObjCObjectPointerType>()) 1183 if (const ObjCObjectPointerType *ToPtrType = 1184 ToType->getAs<ObjCObjectPointerType>()) { 1185 // Objective-C++ conversions are always okay. 1186 // FIXME: We should have a different class of conversions for the 1187 // Objective-C++ implicit conversions. 1188 if (FromPtrType->isObjCBuiltinType() || ToPtrType->isObjCBuiltinType()) 1189 return false; 1190 1191 } 1192 return false; 1193} 1194 1195/// IsMemberPointerConversion - Determines whether the conversion of the 1196/// expression From, which has the (possibly adjusted) type FromType, can be 1197/// converted to the type ToType via a member pointer conversion (C++ 4.11). 1198/// If so, returns true and places the converted type (that might differ from 1199/// ToType in its cv-qualifiers at some level) into ConvertedType. 1200bool Sema::IsMemberPointerConversion(Expr *From, QualType FromType, 1201 QualType ToType, 1202 bool InOverloadResolution, 1203 QualType &ConvertedType) { 1204 const MemberPointerType *ToTypePtr = ToType->getAs<MemberPointerType>(); 1205 if (!ToTypePtr) 1206 return false; 1207 1208 // A null pointer constant can be converted to a member pointer (C++ 4.11p1) 1209 if (From->isNullPointerConstant(Context, 1210 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull 1211 : Expr::NPC_ValueDependentIsNull)) { 1212 ConvertedType = ToType; 1213 return true; 1214 } 1215 1216 // Otherwise, both types have to be member pointers. 1217 const MemberPointerType *FromTypePtr = FromType->getAs<MemberPointerType>(); 1218 if (!FromTypePtr) 1219 return false; 1220 1221 // A pointer to member of B can be converted to a pointer to member of D, 1222 // where D is derived from B (C++ 4.11p2). 1223 QualType FromClass(FromTypePtr->getClass(), 0); 1224 QualType ToClass(ToTypePtr->getClass(), 0); 1225 // FIXME: What happens when these are dependent? Is this function even called? 1226 1227 if (IsDerivedFrom(ToClass, FromClass)) { 1228 ConvertedType = Context.getMemberPointerType(FromTypePtr->getPointeeType(), 1229 ToClass.getTypePtr()); 1230 return true; 1231 } 1232 1233 return false; 1234} 1235 1236/// CheckMemberPointerConversion - Check the member pointer conversion from the 1237/// expression From to the type ToType. This routine checks for ambiguous or 1238/// virtual (FIXME: or inaccessible) base-to-derived member pointer conversions 1239/// for which IsMemberPointerConversion has already returned true. It returns 1240/// true and produces a diagnostic if there was an error, or returns false 1241/// otherwise. 1242bool Sema::CheckMemberPointerConversion(Expr *From, QualType ToType, 1243 CastExpr::CastKind &Kind, 1244 bool IgnoreBaseAccess) { 1245 (void)IgnoreBaseAccess; 1246 QualType FromType = From->getType(); 1247 const MemberPointerType *FromPtrType = FromType->getAs<MemberPointerType>(); 1248 if (!FromPtrType) { 1249 // This must be a null pointer to member pointer conversion 1250 assert(From->isNullPointerConstant(Context, 1251 Expr::NPC_ValueDependentIsNull) && 1252 "Expr must be null pointer constant!"); 1253 Kind = CastExpr::CK_NullToMemberPointer; 1254 return false; 1255 } 1256 1257 const MemberPointerType *ToPtrType = ToType->getAs<MemberPointerType>(); 1258 assert(ToPtrType && "No member pointer cast has a target type " 1259 "that is not a member pointer."); 1260 1261 QualType FromClass = QualType(FromPtrType->getClass(), 0); 1262 QualType ToClass = QualType(ToPtrType->getClass(), 0); 1263 1264 // FIXME: What about dependent types? 1265 assert(FromClass->isRecordType() && "Pointer into non-class."); 1266 assert(ToClass->isRecordType() && "Pointer into non-class."); 1267 1268 CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/false, 1269 /*DetectVirtual=*/true); 1270 bool DerivationOkay = IsDerivedFrom(ToClass, FromClass, Paths); 1271 assert(DerivationOkay && 1272 "Should not have been called if derivation isn't OK."); 1273 (void)DerivationOkay; 1274 1275 if (Paths.isAmbiguous(Context.getCanonicalType(FromClass). 1276 getUnqualifiedType())) { 1277 // Derivation is ambiguous. Redo the check to find the exact paths. 1278 Paths.clear(); 1279 Paths.setRecordingPaths(true); 1280 bool StillOkay = IsDerivedFrom(ToClass, FromClass, Paths); 1281 assert(StillOkay && "Derivation changed due to quantum fluctuation."); 1282 (void)StillOkay; 1283 1284 std::string PathDisplayStr = getAmbiguousPathsDisplayString(Paths); 1285 Diag(From->getExprLoc(), diag::err_ambiguous_memptr_conv) 1286 << 0 << FromClass << ToClass << PathDisplayStr << From->getSourceRange(); 1287 return true; 1288 } 1289 1290 if (const RecordType *VBase = Paths.getDetectedVirtual()) { 1291 Diag(From->getExprLoc(), diag::err_memptr_conv_via_virtual) 1292 << FromClass << ToClass << QualType(VBase, 0) 1293 << From->getSourceRange(); 1294 return true; 1295 } 1296 1297 // Must be a base to derived member conversion. 1298 Kind = CastExpr::CK_BaseToDerivedMemberPointer; 1299 return false; 1300} 1301 1302/// IsQualificationConversion - Determines whether the conversion from 1303/// an rvalue of type FromType to ToType is a qualification conversion 1304/// (C++ 4.4). 1305bool 1306Sema::IsQualificationConversion(QualType FromType, QualType ToType) { 1307 FromType = Context.getCanonicalType(FromType); 1308 ToType = Context.getCanonicalType(ToType); 1309 1310 // If FromType and ToType are the same type, this is not a 1311 // qualification conversion. 1312 if (FromType == ToType) 1313 return false; 1314 1315 // (C++ 4.4p4): 1316 // A conversion can add cv-qualifiers at levels other than the first 1317 // in multi-level pointers, subject to the following rules: [...] 1318 bool PreviousToQualsIncludeConst = true; 1319 bool UnwrappedAnyPointer = false; 1320 while (UnwrapSimilarPointerTypes(FromType, ToType)) { 1321 // Within each iteration of the loop, we check the qualifiers to 1322 // determine if this still looks like a qualification 1323 // conversion. Then, if all is well, we unwrap one more level of 1324 // pointers or pointers-to-members and do it all again 1325 // until there are no more pointers or pointers-to-members left to 1326 // unwrap. 1327 UnwrappedAnyPointer = true; 1328 1329 // -- for every j > 0, if const is in cv 1,j then const is in cv 1330 // 2,j, and similarly for volatile. 1331 if (!ToType.isAtLeastAsQualifiedAs(FromType)) 1332 return false; 1333 1334 // -- if the cv 1,j and cv 2,j are different, then const is in 1335 // every cv for 0 < k < j. 1336 if (FromType.getCVRQualifiers() != ToType.getCVRQualifiers() 1337 && !PreviousToQualsIncludeConst) 1338 return false; 1339 1340 // Keep track of whether all prior cv-qualifiers in the "to" type 1341 // include const. 1342 PreviousToQualsIncludeConst 1343 = PreviousToQualsIncludeConst && ToType.isConstQualified(); 1344 } 1345 1346 // We are left with FromType and ToType being the pointee types 1347 // after unwrapping the original FromType and ToType the same number 1348 // of types. If we unwrapped any pointers, and if FromType and 1349 // ToType have the same unqualified type (since we checked 1350 // qualifiers above), then this is a qualification conversion. 1351 return UnwrappedAnyPointer && Context.hasSameUnqualifiedType(FromType,ToType); 1352} 1353 1354/// \brief Given a function template or function, extract the function template 1355/// declaration (if any) and the underlying function declaration. 1356template<typename T> 1357static void GetFunctionAndTemplate(AnyFunctionDecl Orig, T *&Function, 1358 FunctionTemplateDecl *&FunctionTemplate) { 1359 FunctionTemplate = dyn_cast<FunctionTemplateDecl>(Orig); 1360 if (FunctionTemplate) 1361 Function = cast<T>(FunctionTemplate->getTemplatedDecl()); 1362 else 1363 Function = cast<T>(Orig); 1364} 1365 1366/// Determines whether there is a user-defined conversion sequence 1367/// (C++ [over.ics.user]) that converts expression From to the type 1368/// ToType. If such a conversion exists, User will contain the 1369/// user-defined conversion sequence that performs such a conversion 1370/// and this routine will return true. Otherwise, this routine returns 1371/// false and User is unspecified. 1372/// 1373/// \param AllowConversionFunctions true if the conversion should 1374/// consider conversion functions at all. If false, only constructors 1375/// will be considered. 1376/// 1377/// \param AllowExplicit true if the conversion should consider C++0x 1378/// "explicit" conversion functions as well as non-explicit conversion 1379/// functions (C++0x [class.conv.fct]p2). 1380/// 1381/// \param ForceRValue true if the expression should be treated as an rvalue 1382/// for overload resolution. 1383/// \param UserCast true if looking for user defined conversion for a static 1384/// cast. 1385Sema::OverloadingResult Sema::IsUserDefinedConversion( 1386 Expr *From, QualType ToType, 1387 UserDefinedConversionSequence& User, 1388 OverloadCandidateSet& CandidateSet, 1389 bool AllowConversionFunctions, 1390 bool AllowExplicit, bool ForceRValue, 1391 bool UserCast) { 1392 if (const RecordType *ToRecordType = ToType->getAs<RecordType>()) { 1393 if (RequireCompleteType(From->getLocStart(), ToType, PDiag())) { 1394 // We're not going to find any constructors. 1395 } else if (CXXRecordDecl *ToRecordDecl 1396 = dyn_cast<CXXRecordDecl>(ToRecordType->getDecl())) { 1397 // C++ [over.match.ctor]p1: 1398 // When objects of class type are direct-initialized (8.5), or 1399 // copy-initialized from an expression of the same or a 1400 // derived class type (8.5), overload resolution selects the 1401 // constructor. [...] For copy-initialization, the candidate 1402 // functions are all the converting constructors (12.3.1) of 1403 // that class. The argument list is the expression-list within 1404 // the parentheses of the initializer. 1405 bool SuppressUserConversions = !UserCast; 1406 if (Context.hasSameUnqualifiedType(ToType, From->getType()) || 1407 IsDerivedFrom(From->getType(), ToType)) { 1408 SuppressUserConversions = false; 1409 AllowConversionFunctions = false; 1410 } 1411 1412 DeclarationName ConstructorName 1413 = Context.DeclarationNames.getCXXConstructorName( 1414 Context.getCanonicalType(ToType).getUnqualifiedType()); 1415 DeclContext::lookup_iterator Con, ConEnd; 1416 for (llvm::tie(Con, ConEnd) 1417 = ToRecordDecl->lookup(ConstructorName); 1418 Con != ConEnd; ++Con) { 1419 // Find the constructor (which may be a template). 1420 CXXConstructorDecl *Constructor = 0; 1421 FunctionTemplateDecl *ConstructorTmpl 1422 = dyn_cast<FunctionTemplateDecl>(*Con); 1423 if (ConstructorTmpl) 1424 Constructor 1425 = cast<CXXConstructorDecl>(ConstructorTmpl->getTemplatedDecl()); 1426 else 1427 Constructor = cast<CXXConstructorDecl>(*Con); 1428 1429 if (!Constructor->isInvalidDecl() && 1430 Constructor->isConvertingConstructor(AllowExplicit)) { 1431 if (ConstructorTmpl) 1432 AddTemplateOverloadCandidate(ConstructorTmpl, false, 0, 0, &From, 1433 1, CandidateSet, 1434 SuppressUserConversions, ForceRValue); 1435 else 1436 // Allow one user-defined conversion when user specifies a 1437 // From->ToType conversion via an static cast (c-style, etc). 1438 AddOverloadCandidate(Constructor, &From, 1, CandidateSet, 1439 SuppressUserConversions, ForceRValue); 1440 } 1441 } 1442 } 1443 } 1444 1445 if (!AllowConversionFunctions) { 1446 // Don't allow any conversion functions to enter the overload set. 1447 } else if (RequireCompleteType(From->getLocStart(), From->getType(), 1448 PDiag(0) 1449 << From->getSourceRange())) { 1450 // No conversion functions from incomplete types. 1451 } else if (const RecordType *FromRecordType 1452 = From->getType()->getAs<RecordType>()) { 1453 if (CXXRecordDecl *FromRecordDecl 1454 = dyn_cast<CXXRecordDecl>(FromRecordType->getDecl())) { 1455 // Add all of the conversion functions as candidates. 1456 OverloadedFunctionDecl *Conversions 1457 = FromRecordDecl->getVisibleConversionFunctions(); 1458 for (OverloadedFunctionDecl::function_iterator Func 1459 = Conversions->function_begin(); 1460 Func != Conversions->function_end(); ++Func) { 1461 CXXConversionDecl *Conv; 1462 FunctionTemplateDecl *ConvTemplate; 1463 GetFunctionAndTemplate(*Func, Conv, ConvTemplate); 1464 if (ConvTemplate) 1465 Conv = dyn_cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 1466 else 1467 Conv = dyn_cast<CXXConversionDecl>(*Func); 1468 1469 if (AllowExplicit || !Conv->isExplicit()) { 1470 if (ConvTemplate) 1471 AddTemplateConversionCandidate(ConvTemplate, From, ToType, 1472 CandidateSet); 1473 else 1474 AddConversionCandidate(Conv, From, ToType, CandidateSet); 1475 } 1476 } 1477 } 1478 } 1479 1480 OverloadCandidateSet::iterator Best; 1481 switch (BestViableFunction(CandidateSet, From->getLocStart(), Best)) { 1482 case OR_Success: 1483 // Record the standard conversion we used and the conversion function. 1484 if (CXXConstructorDecl *Constructor 1485 = dyn_cast<CXXConstructorDecl>(Best->Function)) { 1486 // C++ [over.ics.user]p1: 1487 // If the user-defined conversion is specified by a 1488 // constructor (12.3.1), the initial standard conversion 1489 // sequence converts the source type to the type required by 1490 // the argument of the constructor. 1491 // 1492 QualType ThisType = Constructor->getThisType(Context); 1493 if (Best->Conversions[0].ConversionKind == 1494 ImplicitConversionSequence::EllipsisConversion) 1495 User.EllipsisConversion = true; 1496 else { 1497 User.Before = Best->Conversions[0].Standard; 1498 User.EllipsisConversion = false; 1499 } 1500 User.ConversionFunction = Constructor; 1501 User.After.setAsIdentityConversion(); 1502 User.After.FromTypePtr 1503 = ThisType->getAs<PointerType>()->getPointeeType().getAsOpaquePtr(); 1504 User.After.ToTypePtr = ToType.getAsOpaquePtr(); 1505 return OR_Success; 1506 } else if (CXXConversionDecl *Conversion 1507 = dyn_cast<CXXConversionDecl>(Best->Function)) { 1508 // C++ [over.ics.user]p1: 1509 // 1510 // [...] If the user-defined conversion is specified by a 1511 // conversion function (12.3.2), the initial standard 1512 // conversion sequence converts the source type to the 1513 // implicit object parameter of the conversion function. 1514 User.Before = Best->Conversions[0].Standard; 1515 User.ConversionFunction = Conversion; 1516 User.EllipsisConversion = false; 1517 1518 // C++ [over.ics.user]p2: 1519 // The second standard conversion sequence converts the 1520 // result of the user-defined conversion to the target type 1521 // for the sequence. Since an implicit conversion sequence 1522 // is an initialization, the special rules for 1523 // initialization by user-defined conversion apply when 1524 // selecting the best user-defined conversion for a 1525 // user-defined conversion sequence (see 13.3.3 and 1526 // 13.3.3.1). 1527 User.After = Best->FinalConversion; 1528 return OR_Success; 1529 } else { 1530 assert(false && "Not a constructor or conversion function?"); 1531 return OR_No_Viable_Function; 1532 } 1533 1534 case OR_No_Viable_Function: 1535 return OR_No_Viable_Function; 1536 case OR_Deleted: 1537 // No conversion here! We're done. 1538 return OR_Deleted; 1539 1540 case OR_Ambiguous: 1541 return OR_Ambiguous; 1542 } 1543 1544 return OR_No_Viable_Function; 1545} 1546 1547bool 1548Sema::DiagnoseMultipleUserDefinedConversion(Expr *From, QualType ToType) { 1549 ImplicitConversionSequence ICS; 1550 OverloadCandidateSet CandidateSet; 1551 OverloadingResult OvResult = 1552 IsUserDefinedConversion(From, ToType, ICS.UserDefined, 1553 CandidateSet, true, false, false); 1554 if (OvResult == OR_Ambiguous) 1555 Diag(From->getSourceRange().getBegin(), 1556 diag::err_typecheck_ambiguous_condition) 1557 << From->getType() << ToType << From->getSourceRange(); 1558 else if (OvResult == OR_No_Viable_Function && !CandidateSet.empty()) 1559 Diag(From->getSourceRange().getBegin(), 1560 diag::err_typecheck_nonviable_condition) 1561 << From->getType() << ToType << From->getSourceRange(); 1562 else 1563 return false; 1564 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 1565 return true; 1566} 1567 1568/// CompareImplicitConversionSequences - Compare two implicit 1569/// conversion sequences to determine whether one is better than the 1570/// other or if they are indistinguishable (C++ 13.3.3.2). 1571ImplicitConversionSequence::CompareKind 1572Sema::CompareImplicitConversionSequences(const ImplicitConversionSequence& ICS1, 1573 const ImplicitConversionSequence& ICS2) 1574{ 1575 // (C++ 13.3.3.2p2): When comparing the basic forms of implicit 1576 // conversion sequences (as defined in 13.3.3.1) 1577 // -- a standard conversion sequence (13.3.3.1.1) is a better 1578 // conversion sequence than a user-defined conversion sequence or 1579 // an ellipsis conversion sequence, and 1580 // -- a user-defined conversion sequence (13.3.3.1.2) is a better 1581 // conversion sequence than an ellipsis conversion sequence 1582 // (13.3.3.1.3). 1583 // 1584 if (ICS1.ConversionKind < ICS2.ConversionKind) 1585 return ImplicitConversionSequence::Better; 1586 else if (ICS2.ConversionKind < ICS1.ConversionKind) 1587 return ImplicitConversionSequence::Worse; 1588 1589 // Two implicit conversion sequences of the same form are 1590 // indistinguishable conversion sequences unless one of the 1591 // following rules apply: (C++ 13.3.3.2p3): 1592 if (ICS1.ConversionKind == ImplicitConversionSequence::StandardConversion) 1593 return CompareStandardConversionSequences(ICS1.Standard, ICS2.Standard); 1594 else if (ICS1.ConversionKind == 1595 ImplicitConversionSequence::UserDefinedConversion) { 1596 // User-defined conversion sequence U1 is a better conversion 1597 // sequence than another user-defined conversion sequence U2 if 1598 // they contain the same user-defined conversion function or 1599 // constructor and if the second standard conversion sequence of 1600 // U1 is better than the second standard conversion sequence of 1601 // U2 (C++ 13.3.3.2p3). 1602 if (ICS1.UserDefined.ConversionFunction == 1603 ICS2.UserDefined.ConversionFunction) 1604 return CompareStandardConversionSequences(ICS1.UserDefined.After, 1605 ICS2.UserDefined.After); 1606 } 1607 1608 return ImplicitConversionSequence::Indistinguishable; 1609} 1610 1611/// CompareStandardConversionSequences - Compare two standard 1612/// conversion sequences to determine whether one is better than the 1613/// other or if they are indistinguishable (C++ 13.3.3.2p3). 1614ImplicitConversionSequence::CompareKind 1615Sema::CompareStandardConversionSequences(const StandardConversionSequence& SCS1, 1616 const StandardConversionSequence& SCS2) 1617{ 1618 // Standard conversion sequence S1 is a better conversion sequence 1619 // than standard conversion sequence S2 if (C++ 13.3.3.2p3): 1620 1621 // -- S1 is a proper subsequence of S2 (comparing the conversion 1622 // sequences in the canonical form defined by 13.3.3.1.1, 1623 // excluding any Lvalue Transformation; the identity conversion 1624 // sequence is considered to be a subsequence of any 1625 // non-identity conversion sequence) or, if not that, 1626 if (SCS1.Second == SCS2.Second && SCS1.Third == SCS2.Third) 1627 // Neither is a proper subsequence of the other. Do nothing. 1628 ; 1629 else if ((SCS1.Second == ICK_Identity && SCS1.Third == SCS2.Third) || 1630 (SCS1.Third == ICK_Identity && SCS1.Second == SCS2.Second) || 1631 (SCS1.Second == ICK_Identity && 1632 SCS1.Third == ICK_Identity)) 1633 // SCS1 is a proper subsequence of SCS2. 1634 return ImplicitConversionSequence::Better; 1635 else if ((SCS2.Second == ICK_Identity && SCS2.Third == SCS1.Third) || 1636 (SCS2.Third == ICK_Identity && SCS2.Second == SCS1.Second) || 1637 (SCS2.Second == ICK_Identity && 1638 SCS2.Third == ICK_Identity)) 1639 // SCS2 is a proper subsequence of SCS1. 1640 return ImplicitConversionSequence::Worse; 1641 1642 // -- the rank of S1 is better than the rank of S2 (by the rules 1643 // defined below), or, if not that, 1644 ImplicitConversionRank Rank1 = SCS1.getRank(); 1645 ImplicitConversionRank Rank2 = SCS2.getRank(); 1646 if (Rank1 < Rank2) 1647 return ImplicitConversionSequence::Better; 1648 else if (Rank2 < Rank1) 1649 return ImplicitConversionSequence::Worse; 1650 1651 // (C++ 13.3.3.2p4): Two conversion sequences with the same rank 1652 // are indistinguishable unless one of the following rules 1653 // applies: 1654 1655 // A conversion that is not a conversion of a pointer, or 1656 // pointer to member, to bool is better than another conversion 1657 // that is such a conversion. 1658 if (SCS1.isPointerConversionToBool() != SCS2.isPointerConversionToBool()) 1659 return SCS2.isPointerConversionToBool() 1660 ? ImplicitConversionSequence::Better 1661 : ImplicitConversionSequence::Worse; 1662 1663 // C++ [over.ics.rank]p4b2: 1664 // 1665 // If class B is derived directly or indirectly from class A, 1666 // conversion of B* to A* is better than conversion of B* to 1667 // void*, and conversion of A* to void* is better than conversion 1668 // of B* to void*. 1669 bool SCS1ConvertsToVoid 1670 = SCS1.isPointerConversionToVoidPointer(Context); 1671 bool SCS2ConvertsToVoid 1672 = SCS2.isPointerConversionToVoidPointer(Context); 1673 if (SCS1ConvertsToVoid != SCS2ConvertsToVoid) { 1674 // Exactly one of the conversion sequences is a conversion to 1675 // a void pointer; it's the worse conversion. 1676 return SCS2ConvertsToVoid ? ImplicitConversionSequence::Better 1677 : ImplicitConversionSequence::Worse; 1678 } else if (!SCS1ConvertsToVoid && !SCS2ConvertsToVoid) { 1679 // Neither conversion sequence converts to a void pointer; compare 1680 // their derived-to-base conversions. 1681 if (ImplicitConversionSequence::CompareKind DerivedCK 1682 = CompareDerivedToBaseConversions(SCS1, SCS2)) 1683 return DerivedCK; 1684 } else if (SCS1ConvertsToVoid && SCS2ConvertsToVoid) { 1685 // Both conversion sequences are conversions to void 1686 // pointers. Compare the source types to determine if there's an 1687 // inheritance relationship in their sources. 1688 QualType FromType1 = QualType::getFromOpaquePtr(SCS1.FromTypePtr); 1689 QualType FromType2 = QualType::getFromOpaquePtr(SCS2.FromTypePtr); 1690 1691 // Adjust the types we're converting from via the array-to-pointer 1692 // conversion, if we need to. 1693 if (SCS1.First == ICK_Array_To_Pointer) 1694 FromType1 = Context.getArrayDecayedType(FromType1); 1695 if (SCS2.First == ICK_Array_To_Pointer) 1696 FromType2 = Context.getArrayDecayedType(FromType2); 1697 1698 QualType FromPointee1 1699 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1700 QualType FromPointee2 1701 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1702 1703 if (IsDerivedFrom(FromPointee2, FromPointee1)) 1704 return ImplicitConversionSequence::Better; 1705 else if (IsDerivedFrom(FromPointee1, FromPointee2)) 1706 return ImplicitConversionSequence::Worse; 1707 1708 // Objective-C++: If one interface is more specific than the 1709 // other, it is the better one. 1710 const ObjCInterfaceType* FromIface1 = FromPointee1->getAs<ObjCInterfaceType>(); 1711 const ObjCInterfaceType* FromIface2 = FromPointee2->getAs<ObjCInterfaceType>(); 1712 if (FromIface1 && FromIface1) { 1713 if (Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 1714 return ImplicitConversionSequence::Better; 1715 else if (Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 1716 return ImplicitConversionSequence::Worse; 1717 } 1718 } 1719 1720 // Compare based on qualification conversions (C++ 13.3.3.2p3, 1721 // bullet 3). 1722 if (ImplicitConversionSequence::CompareKind QualCK 1723 = CompareQualificationConversions(SCS1, SCS2)) 1724 return QualCK; 1725 1726 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding) { 1727 // C++0x [over.ics.rank]p3b4: 1728 // -- S1 and S2 are reference bindings (8.5.3) and neither refers to an 1729 // implicit object parameter of a non-static member function declared 1730 // without a ref-qualifier, and S1 binds an rvalue reference to an 1731 // rvalue and S2 binds an lvalue reference. 1732 // FIXME: We don't know if we're dealing with the implicit object parameter, 1733 // or if the member function in this case has a ref qualifier. 1734 // (Of course, we don't have ref qualifiers yet.) 1735 if (SCS1.RRefBinding != SCS2.RRefBinding) 1736 return SCS1.RRefBinding ? ImplicitConversionSequence::Better 1737 : ImplicitConversionSequence::Worse; 1738 1739 // C++ [over.ics.rank]p3b4: 1740 // -- S1 and S2 are reference bindings (8.5.3), and the types to 1741 // which the references refer are the same type except for 1742 // top-level cv-qualifiers, and the type to which the reference 1743 // initialized by S2 refers is more cv-qualified than the type 1744 // to which the reference initialized by S1 refers. 1745 QualType T1 = QualType::getFromOpaquePtr(SCS1.ToTypePtr); 1746 QualType T2 = QualType::getFromOpaquePtr(SCS2.ToTypePtr); 1747 T1 = Context.getCanonicalType(T1); 1748 T2 = Context.getCanonicalType(T2); 1749 if (Context.hasSameUnqualifiedType(T1, T2)) { 1750 if (T2.isMoreQualifiedThan(T1)) 1751 return ImplicitConversionSequence::Better; 1752 else if (T1.isMoreQualifiedThan(T2)) 1753 return ImplicitConversionSequence::Worse; 1754 } 1755 } 1756 1757 return ImplicitConversionSequence::Indistinguishable; 1758} 1759 1760/// CompareQualificationConversions - Compares two standard conversion 1761/// sequences to determine whether they can be ranked based on their 1762/// qualification conversions (C++ 13.3.3.2p3 bullet 3). 1763ImplicitConversionSequence::CompareKind 1764Sema::CompareQualificationConversions(const StandardConversionSequence& SCS1, 1765 const StandardConversionSequence& SCS2) { 1766 // C++ 13.3.3.2p3: 1767 // -- S1 and S2 differ only in their qualification conversion and 1768 // yield similar types T1 and T2 (C++ 4.4), respectively, and the 1769 // cv-qualification signature of type T1 is a proper subset of 1770 // the cv-qualification signature of type T2, and S1 is not the 1771 // deprecated string literal array-to-pointer conversion (4.2). 1772 if (SCS1.First != SCS2.First || SCS1.Second != SCS2.Second || 1773 SCS1.Third != SCS2.Third || SCS1.Third != ICK_Qualification) 1774 return ImplicitConversionSequence::Indistinguishable; 1775 1776 // FIXME: the example in the standard doesn't use a qualification 1777 // conversion (!) 1778 QualType T1 = QualType::getFromOpaquePtr(SCS1.ToTypePtr); 1779 QualType T2 = QualType::getFromOpaquePtr(SCS2.ToTypePtr); 1780 T1 = Context.getCanonicalType(T1); 1781 T2 = Context.getCanonicalType(T2); 1782 1783 // If the types are the same, we won't learn anything by unwrapped 1784 // them. 1785 if (Context.hasSameUnqualifiedType(T1, T2)) 1786 return ImplicitConversionSequence::Indistinguishable; 1787 1788 ImplicitConversionSequence::CompareKind Result 1789 = ImplicitConversionSequence::Indistinguishable; 1790 while (UnwrapSimilarPointerTypes(T1, T2)) { 1791 // Within each iteration of the loop, we check the qualifiers to 1792 // determine if this still looks like a qualification 1793 // conversion. Then, if all is well, we unwrap one more level of 1794 // pointers or pointers-to-members and do it all again 1795 // until there are no more pointers or pointers-to-members left 1796 // to unwrap. This essentially mimics what 1797 // IsQualificationConversion does, but here we're checking for a 1798 // strict subset of qualifiers. 1799 if (T1.getCVRQualifiers() == T2.getCVRQualifiers()) 1800 // The qualifiers are the same, so this doesn't tell us anything 1801 // about how the sequences rank. 1802 ; 1803 else if (T2.isMoreQualifiedThan(T1)) { 1804 // T1 has fewer qualifiers, so it could be the better sequence. 1805 if (Result == ImplicitConversionSequence::Worse) 1806 // Neither has qualifiers that are a subset of the other's 1807 // qualifiers. 1808 return ImplicitConversionSequence::Indistinguishable; 1809 1810 Result = ImplicitConversionSequence::Better; 1811 } else if (T1.isMoreQualifiedThan(T2)) { 1812 // T2 has fewer qualifiers, so it could be the better sequence. 1813 if (Result == ImplicitConversionSequence::Better) 1814 // Neither has qualifiers that are a subset of the other's 1815 // qualifiers. 1816 return ImplicitConversionSequence::Indistinguishable; 1817 1818 Result = ImplicitConversionSequence::Worse; 1819 } else { 1820 // Qualifiers are disjoint. 1821 return ImplicitConversionSequence::Indistinguishable; 1822 } 1823 1824 // If the types after this point are equivalent, we're done. 1825 if (Context.hasSameUnqualifiedType(T1, T2)) 1826 break; 1827 } 1828 1829 // Check that the winning standard conversion sequence isn't using 1830 // the deprecated string literal array to pointer conversion. 1831 switch (Result) { 1832 case ImplicitConversionSequence::Better: 1833 if (SCS1.Deprecated) 1834 Result = ImplicitConversionSequence::Indistinguishable; 1835 break; 1836 1837 case ImplicitConversionSequence::Indistinguishable: 1838 break; 1839 1840 case ImplicitConversionSequence::Worse: 1841 if (SCS2.Deprecated) 1842 Result = ImplicitConversionSequence::Indistinguishable; 1843 break; 1844 } 1845 1846 return Result; 1847} 1848 1849/// CompareDerivedToBaseConversions - Compares two standard conversion 1850/// sequences to determine whether they can be ranked based on their 1851/// various kinds of derived-to-base conversions (C++ 1852/// [over.ics.rank]p4b3). As part of these checks, we also look at 1853/// conversions between Objective-C interface types. 1854ImplicitConversionSequence::CompareKind 1855Sema::CompareDerivedToBaseConversions(const StandardConversionSequence& SCS1, 1856 const StandardConversionSequence& SCS2) { 1857 QualType FromType1 = QualType::getFromOpaquePtr(SCS1.FromTypePtr); 1858 QualType ToType1 = QualType::getFromOpaquePtr(SCS1.ToTypePtr); 1859 QualType FromType2 = QualType::getFromOpaquePtr(SCS2.FromTypePtr); 1860 QualType ToType2 = QualType::getFromOpaquePtr(SCS2.ToTypePtr); 1861 1862 // Adjust the types we're converting from via the array-to-pointer 1863 // conversion, if we need to. 1864 if (SCS1.First == ICK_Array_To_Pointer) 1865 FromType1 = Context.getArrayDecayedType(FromType1); 1866 if (SCS2.First == ICK_Array_To_Pointer) 1867 FromType2 = Context.getArrayDecayedType(FromType2); 1868 1869 // Canonicalize all of the types. 1870 FromType1 = Context.getCanonicalType(FromType1); 1871 ToType1 = Context.getCanonicalType(ToType1); 1872 FromType2 = Context.getCanonicalType(FromType2); 1873 ToType2 = Context.getCanonicalType(ToType2); 1874 1875 // C++ [over.ics.rank]p4b3: 1876 // 1877 // If class B is derived directly or indirectly from class A and 1878 // class C is derived directly or indirectly from B, 1879 // 1880 // For Objective-C, we let A, B, and C also be Objective-C 1881 // interfaces. 1882 1883 // Compare based on pointer conversions. 1884 if (SCS1.Second == ICK_Pointer_Conversion && 1885 SCS2.Second == ICK_Pointer_Conversion && 1886 /*FIXME: Remove if Objective-C id conversions get their own rank*/ 1887 FromType1->isPointerType() && FromType2->isPointerType() && 1888 ToType1->isPointerType() && ToType2->isPointerType()) { 1889 QualType FromPointee1 1890 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1891 QualType ToPointee1 1892 = ToType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1893 QualType FromPointee2 1894 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1895 QualType ToPointee2 1896 = ToType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1897 1898 const ObjCInterfaceType* FromIface1 = FromPointee1->getAs<ObjCInterfaceType>(); 1899 const ObjCInterfaceType* FromIface2 = FromPointee2->getAs<ObjCInterfaceType>(); 1900 const ObjCInterfaceType* ToIface1 = ToPointee1->getAs<ObjCInterfaceType>(); 1901 const ObjCInterfaceType* ToIface2 = ToPointee2->getAs<ObjCInterfaceType>(); 1902 1903 // -- conversion of C* to B* is better than conversion of C* to A*, 1904 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 1905 if (IsDerivedFrom(ToPointee1, ToPointee2)) 1906 return ImplicitConversionSequence::Better; 1907 else if (IsDerivedFrom(ToPointee2, ToPointee1)) 1908 return ImplicitConversionSequence::Worse; 1909 1910 if (ToIface1 && ToIface2) { 1911 if (Context.canAssignObjCInterfaces(ToIface2, ToIface1)) 1912 return ImplicitConversionSequence::Better; 1913 else if (Context.canAssignObjCInterfaces(ToIface1, ToIface2)) 1914 return ImplicitConversionSequence::Worse; 1915 } 1916 } 1917 1918 // -- conversion of B* to A* is better than conversion of C* to A*, 1919 if (FromPointee1 != FromPointee2 && ToPointee1 == ToPointee2) { 1920 if (IsDerivedFrom(FromPointee2, FromPointee1)) 1921 return ImplicitConversionSequence::Better; 1922 else if (IsDerivedFrom(FromPointee1, FromPointee2)) 1923 return ImplicitConversionSequence::Worse; 1924 1925 if (FromIface1 && FromIface2) { 1926 if (Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 1927 return ImplicitConversionSequence::Better; 1928 else if (Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 1929 return ImplicitConversionSequence::Worse; 1930 } 1931 } 1932 } 1933 1934 // Compare based on reference bindings. 1935 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding && 1936 SCS1.Second == ICK_Derived_To_Base) { 1937 // -- binding of an expression of type C to a reference of type 1938 // B& is better than binding an expression of type C to a 1939 // reference of type A&, 1940 if (Context.hasSameUnqualifiedType(FromType1, FromType2) && 1941 !Context.hasSameUnqualifiedType(ToType1, ToType2)) { 1942 if (IsDerivedFrom(ToType1, ToType2)) 1943 return ImplicitConversionSequence::Better; 1944 else if (IsDerivedFrom(ToType2, ToType1)) 1945 return ImplicitConversionSequence::Worse; 1946 } 1947 1948 // -- binding of an expression of type B to a reference of type 1949 // A& is better than binding an expression of type C to a 1950 // reference of type A&, 1951 if (!Context.hasSameUnqualifiedType(FromType1, FromType2) && 1952 Context.hasSameUnqualifiedType(ToType1, ToType2)) { 1953 if (IsDerivedFrom(FromType2, FromType1)) 1954 return ImplicitConversionSequence::Better; 1955 else if (IsDerivedFrom(FromType1, FromType2)) 1956 return ImplicitConversionSequence::Worse; 1957 } 1958 } 1959 1960 // Ranking of member-pointer types. 1961 if (SCS1.Second == ICK_Pointer_Member && SCS2.Second == ICK_Pointer_Member && 1962 FromType1->isMemberPointerType() && FromType2->isMemberPointerType() && 1963 ToType1->isMemberPointerType() && ToType2->isMemberPointerType()) { 1964 const MemberPointerType * FromMemPointer1 = 1965 FromType1->getAs<MemberPointerType>(); 1966 const MemberPointerType * ToMemPointer1 = 1967 ToType1->getAs<MemberPointerType>(); 1968 const MemberPointerType * FromMemPointer2 = 1969 FromType2->getAs<MemberPointerType>(); 1970 const MemberPointerType * ToMemPointer2 = 1971 ToType2->getAs<MemberPointerType>(); 1972 const Type *FromPointeeType1 = FromMemPointer1->getClass(); 1973 const Type *ToPointeeType1 = ToMemPointer1->getClass(); 1974 const Type *FromPointeeType2 = FromMemPointer2->getClass(); 1975 const Type *ToPointeeType2 = ToMemPointer2->getClass(); 1976 QualType FromPointee1 = QualType(FromPointeeType1, 0).getUnqualifiedType(); 1977 QualType ToPointee1 = QualType(ToPointeeType1, 0).getUnqualifiedType(); 1978 QualType FromPointee2 = QualType(FromPointeeType2, 0).getUnqualifiedType(); 1979 QualType ToPointee2 = QualType(ToPointeeType2, 0).getUnqualifiedType(); 1980 // conversion of A::* to B::* is better than conversion of A::* to C::*, 1981 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 1982 if (IsDerivedFrom(ToPointee1, ToPointee2)) 1983 return ImplicitConversionSequence::Worse; 1984 else if (IsDerivedFrom(ToPointee2, ToPointee1)) 1985 return ImplicitConversionSequence::Better; 1986 } 1987 // conversion of B::* to C::* is better than conversion of A::* to C::* 1988 if (ToPointee1 == ToPointee2 && FromPointee1 != FromPointee2) { 1989 if (IsDerivedFrom(FromPointee1, FromPointee2)) 1990 return ImplicitConversionSequence::Better; 1991 else if (IsDerivedFrom(FromPointee2, FromPointee1)) 1992 return ImplicitConversionSequence::Worse; 1993 } 1994 } 1995 1996 if (SCS1.CopyConstructor && SCS2.CopyConstructor && 1997 SCS1.Second == ICK_Derived_To_Base) { 1998 // -- conversion of C to B is better than conversion of C to A, 1999 if (Context.hasSameUnqualifiedType(FromType1, FromType2) && 2000 !Context.hasSameUnqualifiedType(ToType1, ToType2)) { 2001 if (IsDerivedFrom(ToType1, ToType2)) 2002 return ImplicitConversionSequence::Better; 2003 else if (IsDerivedFrom(ToType2, ToType1)) 2004 return ImplicitConversionSequence::Worse; 2005 } 2006 2007 // -- conversion of B to A is better than conversion of C to A. 2008 if (!Context.hasSameUnqualifiedType(FromType1, FromType2) && 2009 Context.hasSameUnqualifiedType(ToType1, ToType2)) { 2010 if (IsDerivedFrom(FromType2, FromType1)) 2011 return ImplicitConversionSequence::Better; 2012 else if (IsDerivedFrom(FromType1, FromType2)) 2013 return ImplicitConversionSequence::Worse; 2014 } 2015 } 2016 2017 return ImplicitConversionSequence::Indistinguishable; 2018} 2019 2020/// TryCopyInitialization - Try to copy-initialize a value of type 2021/// ToType from the expression From. Return the implicit conversion 2022/// sequence required to pass this argument, which may be a bad 2023/// conversion sequence (meaning that the argument cannot be passed to 2024/// a parameter of this type). If @p SuppressUserConversions, then we 2025/// do not permit any user-defined conversion sequences. If @p ForceRValue, 2026/// then we treat @p From as an rvalue, even if it is an lvalue. 2027ImplicitConversionSequence 2028Sema::TryCopyInitialization(Expr *From, QualType ToType, 2029 bool SuppressUserConversions, bool ForceRValue, 2030 bool InOverloadResolution) { 2031 if (ToType->isReferenceType()) { 2032 ImplicitConversionSequence ICS; 2033 CheckReferenceInit(From, ToType, 2034 /*FIXME:*/From->getLocStart(), 2035 SuppressUserConversions, 2036 /*AllowExplicit=*/false, 2037 ForceRValue, 2038 &ICS); 2039 return ICS; 2040 } else { 2041 return TryImplicitConversion(From, ToType, 2042 SuppressUserConversions, 2043 /*AllowExplicit=*/false, 2044 ForceRValue, 2045 InOverloadResolution); 2046 } 2047} 2048 2049/// PerformCopyInitialization - Copy-initialize an object of type @p ToType with 2050/// the expression @p From. Returns true (and emits a diagnostic) if there was 2051/// an error, returns false if the initialization succeeded. Elidable should 2052/// be true when the copy may be elided (C++ 12.8p15). Overload resolution works 2053/// differently in C++0x for this case. 2054bool Sema::PerformCopyInitialization(Expr *&From, QualType ToType, 2055 const char* Flavor, bool Elidable) { 2056 if (!getLangOptions().CPlusPlus) { 2057 // In C, argument passing is the same as performing an assignment. 2058 QualType FromType = From->getType(); 2059 2060 AssignConvertType ConvTy = 2061 CheckSingleAssignmentConstraints(ToType, From); 2062 if (ConvTy != Compatible && 2063 CheckTransparentUnionArgumentConstraints(ToType, From) == Compatible) 2064 ConvTy = Compatible; 2065 2066 return DiagnoseAssignmentResult(ConvTy, From->getLocStart(), ToType, 2067 FromType, From, Flavor); 2068 } 2069 2070 if (ToType->isReferenceType()) 2071 return CheckReferenceInit(From, ToType, 2072 /*FIXME:*/From->getLocStart(), 2073 /*SuppressUserConversions=*/false, 2074 /*AllowExplicit=*/false, 2075 /*ForceRValue=*/false); 2076 2077 if (!PerformImplicitConversion(From, ToType, Flavor, 2078 /*AllowExplicit=*/false, Elidable)) 2079 return false; 2080 if (!DiagnoseMultipleUserDefinedConversion(From, ToType)) 2081 return Diag(From->getSourceRange().getBegin(), 2082 diag::err_typecheck_convert_incompatible) 2083 << ToType << From->getType() << Flavor << From->getSourceRange(); 2084 return true; 2085} 2086 2087/// TryObjectArgumentInitialization - Try to initialize the object 2088/// parameter of the given member function (@c Method) from the 2089/// expression @p From. 2090ImplicitConversionSequence 2091Sema::TryObjectArgumentInitialization(Expr *From, CXXMethodDecl *Method) { 2092 QualType ClassType = Context.getTypeDeclType(Method->getParent()); 2093 // [class.dtor]p2: A destructor can be invoked for a const, volatile or 2094 // const volatile object. 2095 unsigned Quals = isa<CXXDestructorDecl>(Method) ? 2096 Qualifiers::Const | Qualifiers::Volatile : Method->getTypeQualifiers(); 2097 QualType ImplicitParamType = Context.getCVRQualifiedType(ClassType, Quals); 2098 2099 // Set up the conversion sequence as a "bad" conversion, to allow us 2100 // to exit early. 2101 ImplicitConversionSequence ICS; 2102 ICS.Standard.setAsIdentityConversion(); 2103 ICS.ConversionKind = ImplicitConversionSequence::BadConversion; 2104 2105 // We need to have an object of class type. 2106 QualType FromType = From->getType(); 2107 if (const PointerType *PT = FromType->getAs<PointerType>()) 2108 FromType = PT->getPointeeType(); 2109 2110 assert(FromType->isRecordType()); 2111 2112 // The implicit object parameter is has the type "reference to cv X", 2113 // where X is the class of which the function is a member 2114 // (C++ [over.match.funcs]p4). However, when finding an implicit 2115 // conversion sequence for the argument, we are not allowed to 2116 // create temporaries or perform user-defined conversions 2117 // (C++ [over.match.funcs]p5). We perform a simplified version of 2118 // reference binding here, that allows class rvalues to bind to 2119 // non-constant references. 2120 2121 // First check the qualifiers. We don't care about lvalue-vs-rvalue 2122 // with the implicit object parameter (C++ [over.match.funcs]p5). 2123 QualType FromTypeCanon = Context.getCanonicalType(FromType); 2124 if (ImplicitParamType.getCVRQualifiers() 2125 != FromTypeCanon.getLocalCVRQualifiers() && 2126 !ImplicitParamType.isAtLeastAsQualifiedAs(FromTypeCanon)) 2127 return ICS; 2128 2129 // Check that we have either the same type or a derived type. It 2130 // affects the conversion rank. 2131 QualType ClassTypeCanon = Context.getCanonicalType(ClassType); 2132 if (ClassTypeCanon == FromTypeCanon.getLocalUnqualifiedType()) 2133 ICS.Standard.Second = ICK_Identity; 2134 else if (IsDerivedFrom(FromType, ClassType)) 2135 ICS.Standard.Second = ICK_Derived_To_Base; 2136 else 2137 return ICS; 2138 2139 // Success. Mark this as a reference binding. 2140 ICS.ConversionKind = ImplicitConversionSequence::StandardConversion; 2141 ICS.Standard.FromTypePtr = FromType.getAsOpaquePtr(); 2142 ICS.Standard.ToTypePtr = ImplicitParamType.getAsOpaquePtr(); 2143 ICS.Standard.ReferenceBinding = true; 2144 ICS.Standard.DirectBinding = true; 2145 ICS.Standard.RRefBinding = false; 2146 return ICS; 2147} 2148 2149/// PerformObjectArgumentInitialization - Perform initialization of 2150/// the implicit object parameter for the given Method with the given 2151/// expression. 2152bool 2153Sema::PerformObjectArgumentInitialization(Expr *&From, CXXMethodDecl *Method) { 2154 QualType FromRecordType, DestType; 2155 QualType ImplicitParamRecordType = 2156 Method->getThisType(Context)->getAs<PointerType>()->getPointeeType(); 2157 2158 if (const PointerType *PT = From->getType()->getAs<PointerType>()) { 2159 FromRecordType = PT->getPointeeType(); 2160 DestType = Method->getThisType(Context); 2161 } else { 2162 FromRecordType = From->getType(); 2163 DestType = ImplicitParamRecordType; 2164 } 2165 2166 ImplicitConversionSequence ICS 2167 = TryObjectArgumentInitialization(From, Method); 2168 if (ICS.ConversionKind == ImplicitConversionSequence::BadConversion) 2169 return Diag(From->getSourceRange().getBegin(), 2170 diag::err_implicit_object_parameter_init) 2171 << ImplicitParamRecordType << FromRecordType << From->getSourceRange(); 2172 2173 if (ICS.Standard.Second == ICK_Derived_To_Base && 2174 CheckDerivedToBaseConversion(FromRecordType, 2175 ImplicitParamRecordType, 2176 From->getSourceRange().getBegin(), 2177 From->getSourceRange())) 2178 return true; 2179 2180 ImpCastExprToType(From, DestType, CastExpr::CK_DerivedToBase, 2181 /*isLvalue=*/true); 2182 return false; 2183} 2184 2185/// TryContextuallyConvertToBool - Attempt to contextually convert the 2186/// expression From to bool (C++0x [conv]p3). 2187ImplicitConversionSequence Sema::TryContextuallyConvertToBool(Expr *From) { 2188 return TryImplicitConversion(From, Context.BoolTy, 2189 // FIXME: Are these flags correct? 2190 /*SuppressUserConversions=*/false, 2191 /*AllowExplicit=*/true, 2192 /*ForceRValue=*/false, 2193 /*InOverloadResolution=*/false); 2194} 2195 2196/// PerformContextuallyConvertToBool - Perform a contextual conversion 2197/// of the expression From to bool (C++0x [conv]p3). 2198bool Sema::PerformContextuallyConvertToBool(Expr *&From) { 2199 ImplicitConversionSequence ICS = TryContextuallyConvertToBool(From); 2200 if (!PerformImplicitConversion(From, Context.BoolTy, ICS, "converting")) 2201 return false; 2202 2203 if (!DiagnoseMultipleUserDefinedConversion(From, Context.BoolTy)) 2204 return Diag(From->getSourceRange().getBegin(), 2205 diag::err_typecheck_bool_condition) 2206 << From->getType() << From->getSourceRange(); 2207 return true; 2208} 2209 2210/// AddOverloadCandidate - Adds the given function to the set of 2211/// candidate functions, using the given function call arguments. If 2212/// @p SuppressUserConversions, then don't allow user-defined 2213/// conversions via constructors or conversion operators. 2214/// If @p ForceRValue, treat all arguments as rvalues. This is a slightly 2215/// hacky way to implement the overloading rules for elidable copy 2216/// initialization in C++0x (C++0x 12.8p15). 2217/// 2218/// \para PartialOverloading true if we are performing "partial" overloading 2219/// based on an incomplete set of function arguments. This feature is used by 2220/// code completion. 2221void 2222Sema::AddOverloadCandidate(FunctionDecl *Function, 2223 Expr **Args, unsigned NumArgs, 2224 OverloadCandidateSet& CandidateSet, 2225 bool SuppressUserConversions, 2226 bool ForceRValue, 2227 bool PartialOverloading) { 2228 const FunctionProtoType* Proto 2229 = dyn_cast<FunctionProtoType>(Function->getType()->getAs<FunctionType>()); 2230 assert(Proto && "Functions without a prototype cannot be overloaded"); 2231 assert(!isa<CXXConversionDecl>(Function) && 2232 "Use AddConversionCandidate for conversion functions"); 2233 assert(!Function->getDescribedFunctionTemplate() && 2234 "Use AddTemplateOverloadCandidate for function templates"); 2235 2236 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Function)) { 2237 if (!isa<CXXConstructorDecl>(Method)) { 2238 // If we get here, it's because we're calling a member function 2239 // that is named without a member access expression (e.g., 2240 // "this->f") that was either written explicitly or created 2241 // implicitly. This can happen with a qualified call to a member 2242 // function, e.g., X::f(). We use a NULL object as the implied 2243 // object argument (C++ [over.call.func]p3). 2244 AddMethodCandidate(Method, 0, Args, NumArgs, CandidateSet, 2245 SuppressUserConversions, ForceRValue); 2246 return; 2247 } 2248 // We treat a constructor like a non-member function, since its object 2249 // argument doesn't participate in overload resolution. 2250 } 2251 2252 if (!CandidateSet.isNewCandidate(Function)) 2253 return; 2254 2255 if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(Function)){ 2256 // C++ [class.copy]p3: 2257 // A member function template is never instantiated to perform the copy 2258 // of a class object to an object of its class type. 2259 QualType ClassType = Context.getTypeDeclType(Constructor->getParent()); 2260 if (NumArgs == 1 && 2261 Constructor->isCopyConstructorLikeSpecialization() && 2262 Context.hasSameUnqualifiedType(ClassType, Args[0]->getType())) 2263 return; 2264 } 2265 2266 // Add this candidate 2267 CandidateSet.push_back(OverloadCandidate()); 2268 OverloadCandidate& Candidate = CandidateSet.back(); 2269 Candidate.Function = Function; 2270 Candidate.Viable = true; 2271 Candidate.IsSurrogate = false; 2272 Candidate.IgnoreObjectArgument = false; 2273 2274 unsigned NumArgsInProto = Proto->getNumArgs(); 2275 2276 // (C++ 13.3.2p2): A candidate function having fewer than m 2277 // parameters is viable only if it has an ellipsis in its parameter 2278 // list (8.3.5). 2279 if ((NumArgs + (PartialOverloading && NumArgs)) > NumArgsInProto && 2280 !Proto->isVariadic()) { 2281 Candidate.Viable = false; 2282 return; 2283 } 2284 2285 // (C++ 13.3.2p2): A candidate function having more than m parameters 2286 // is viable only if the (m+1)st parameter has a default argument 2287 // (8.3.6). For the purposes of overload resolution, the 2288 // parameter list is truncated on the right, so that there are 2289 // exactly m parameters. 2290 unsigned MinRequiredArgs = Function->getMinRequiredArguments(); 2291 if (NumArgs < MinRequiredArgs && !PartialOverloading) { 2292 // Not enough arguments. 2293 Candidate.Viable = false; 2294 return; 2295 } 2296 2297 // Determine the implicit conversion sequences for each of the 2298 // arguments. 2299 Candidate.Conversions.resize(NumArgs); 2300 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2301 if (ArgIdx < NumArgsInProto) { 2302 // (C++ 13.3.2p3): for F to be a viable function, there shall 2303 // exist for each argument an implicit conversion sequence 2304 // (13.3.3.1) that converts that argument to the corresponding 2305 // parameter of F. 2306 QualType ParamType = Proto->getArgType(ArgIdx); 2307 Candidate.Conversions[ArgIdx] 2308 = TryCopyInitialization(Args[ArgIdx], ParamType, 2309 SuppressUserConversions, ForceRValue, 2310 /*InOverloadResolution=*/true); 2311 if (Candidate.Conversions[ArgIdx].ConversionKind 2312 == ImplicitConversionSequence::BadConversion) { 2313 // 13.3.3.1-p10 If several different sequences of conversions exist that 2314 // each convert the argument to the parameter type, the implicit conversion 2315 // sequence associated with the parameter is defined to be the unique conversion 2316 // sequence designated the ambiguous conversion sequence. For the purpose of 2317 // ranking implicit conversion sequences as described in 13.3.3.2, the ambiguous 2318 // conversion sequence is treated as a user-defined sequence that is 2319 // indistinguishable from any other user-defined conversion sequence 2320 if (!Candidate.Conversions[ArgIdx].ConversionFunctionSet.empty()) { 2321 Candidate.Conversions[ArgIdx].ConversionKind = 2322 ImplicitConversionSequence::UserDefinedConversion; 2323 // Set the conversion function to one of them. As due to ambiguity, 2324 // they carry the same weight and is needed for overload resolution 2325 // later. 2326 Candidate.Conversions[ArgIdx].UserDefined.ConversionFunction = 2327 Candidate.Conversions[ArgIdx].ConversionFunctionSet[0]; 2328 } 2329 else { 2330 Candidate.Viable = false; 2331 break; 2332 } 2333 } 2334 } else { 2335 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2336 // argument for which there is no corresponding parameter is 2337 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2338 Candidate.Conversions[ArgIdx].ConversionKind 2339 = ImplicitConversionSequence::EllipsisConversion; 2340 } 2341 } 2342} 2343 2344/// \brief Add all of the function declarations in the given function set to 2345/// the overload canddiate set. 2346void Sema::AddFunctionCandidates(const FunctionSet &Functions, 2347 Expr **Args, unsigned NumArgs, 2348 OverloadCandidateSet& CandidateSet, 2349 bool SuppressUserConversions) { 2350 for (FunctionSet::const_iterator F = Functions.begin(), 2351 FEnd = Functions.end(); 2352 F != FEnd; ++F) { 2353 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*F)) { 2354 if (isa<CXXMethodDecl>(FD) && !cast<CXXMethodDecl>(FD)->isStatic()) 2355 AddMethodCandidate(cast<CXXMethodDecl>(FD), 2356 Args[0], Args + 1, NumArgs - 1, 2357 CandidateSet, SuppressUserConversions); 2358 else 2359 AddOverloadCandidate(FD, Args, NumArgs, CandidateSet, 2360 SuppressUserConversions); 2361 } else { 2362 FunctionTemplateDecl *FunTmpl = cast<FunctionTemplateDecl>(*F); 2363 if (isa<CXXMethodDecl>(FunTmpl->getTemplatedDecl()) && 2364 !cast<CXXMethodDecl>(FunTmpl->getTemplatedDecl())->isStatic()) 2365 AddMethodTemplateCandidate(FunTmpl, 2366 /*FIXME: explicit args */false, 0, 0, 2367 Args[0], Args + 1, NumArgs - 1, 2368 CandidateSet, 2369 SuppressUserConversions); 2370 else 2371 AddTemplateOverloadCandidate(FunTmpl, 2372 /*FIXME: explicit args */false, 0, 0, 2373 Args, NumArgs, CandidateSet, 2374 SuppressUserConversions); 2375 } 2376 } 2377} 2378 2379/// AddMethodCandidate - Adds a named decl (which is some kind of 2380/// method) as a method candidate to the given overload set. 2381void Sema::AddMethodCandidate(NamedDecl *Decl, Expr *Object, 2382 Expr **Args, unsigned NumArgs, 2383 OverloadCandidateSet& CandidateSet, 2384 bool SuppressUserConversions, bool ForceRValue) { 2385 2386 // FIXME: use this 2387 //DeclContext *ActingContext = Decl->getDeclContext(); 2388 2389 if (isa<UsingShadowDecl>(Decl)) 2390 Decl = cast<UsingShadowDecl>(Decl)->getTargetDecl(); 2391 2392 if (FunctionTemplateDecl *TD = dyn_cast<FunctionTemplateDecl>(Decl)) { 2393 assert(isa<CXXMethodDecl>(TD->getTemplatedDecl()) && 2394 "Expected a member function template"); 2395 AddMethodTemplateCandidate(TD, false, 0, 0, 2396 Object, Args, NumArgs, 2397 CandidateSet, 2398 SuppressUserConversions, 2399 ForceRValue); 2400 } else { 2401 AddMethodCandidate(cast<CXXMethodDecl>(Decl), Object, Args, NumArgs, 2402 CandidateSet, SuppressUserConversions, ForceRValue); 2403 } 2404} 2405 2406/// AddMethodCandidate - Adds the given C++ member function to the set 2407/// of candidate functions, using the given function call arguments 2408/// and the object argument (@c Object). For example, in a call 2409/// @c o.f(a1,a2), @c Object will contain @c o and @c Args will contain 2410/// both @c a1 and @c a2. If @p SuppressUserConversions, then don't 2411/// allow user-defined conversions via constructors or conversion 2412/// operators. If @p ForceRValue, treat all arguments as rvalues. This is 2413/// a slightly hacky way to implement the overloading rules for elidable copy 2414/// initialization in C++0x (C++0x 12.8p15). 2415void 2416Sema::AddMethodCandidate(CXXMethodDecl *Method, Expr *Object, 2417 Expr **Args, unsigned NumArgs, 2418 OverloadCandidateSet& CandidateSet, 2419 bool SuppressUserConversions, bool ForceRValue) { 2420 const FunctionProtoType* Proto 2421 = dyn_cast<FunctionProtoType>(Method->getType()->getAs<FunctionType>()); 2422 assert(Proto && "Methods without a prototype cannot be overloaded"); 2423 assert(!isa<CXXConversionDecl>(Method) && 2424 "Use AddConversionCandidate for conversion functions"); 2425 assert(!isa<CXXConstructorDecl>(Method) && 2426 "Use AddOverloadCandidate for constructors"); 2427 2428 if (!CandidateSet.isNewCandidate(Method)) 2429 return; 2430 2431 // Add this candidate 2432 CandidateSet.push_back(OverloadCandidate()); 2433 OverloadCandidate& Candidate = CandidateSet.back(); 2434 Candidate.Function = Method; 2435 Candidate.IsSurrogate = false; 2436 Candidate.IgnoreObjectArgument = false; 2437 2438 unsigned NumArgsInProto = Proto->getNumArgs(); 2439 2440 // (C++ 13.3.2p2): A candidate function having fewer than m 2441 // parameters is viable only if it has an ellipsis in its parameter 2442 // list (8.3.5). 2443 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 2444 Candidate.Viable = false; 2445 return; 2446 } 2447 2448 // (C++ 13.3.2p2): A candidate function having more than m parameters 2449 // is viable only if the (m+1)st parameter has a default argument 2450 // (8.3.6). For the purposes of overload resolution, the 2451 // parameter list is truncated on the right, so that there are 2452 // exactly m parameters. 2453 unsigned MinRequiredArgs = Method->getMinRequiredArguments(); 2454 if (NumArgs < MinRequiredArgs) { 2455 // Not enough arguments. 2456 Candidate.Viable = false; 2457 return; 2458 } 2459 2460 Candidate.Viable = true; 2461 Candidate.Conversions.resize(NumArgs + 1); 2462 2463 if (Method->isStatic() || !Object) 2464 // The implicit object argument is ignored. 2465 Candidate.IgnoreObjectArgument = true; 2466 else { 2467 // Determine the implicit conversion sequence for the object 2468 // parameter. 2469 Candidate.Conversions[0] = TryObjectArgumentInitialization(Object, Method); 2470 if (Candidate.Conversions[0].ConversionKind 2471 == ImplicitConversionSequence::BadConversion) { 2472 Candidate.Viable = false; 2473 return; 2474 } 2475 } 2476 2477 // Determine the implicit conversion sequences for each of the 2478 // arguments. 2479 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2480 if (ArgIdx < NumArgsInProto) { 2481 // (C++ 13.3.2p3): for F to be a viable function, there shall 2482 // exist for each argument an implicit conversion sequence 2483 // (13.3.3.1) that converts that argument to the corresponding 2484 // parameter of F. 2485 QualType ParamType = Proto->getArgType(ArgIdx); 2486 Candidate.Conversions[ArgIdx + 1] 2487 = TryCopyInitialization(Args[ArgIdx], ParamType, 2488 SuppressUserConversions, ForceRValue, 2489 /*InOverloadResolution=*/true); 2490 if (Candidate.Conversions[ArgIdx + 1].ConversionKind 2491 == ImplicitConversionSequence::BadConversion) { 2492 Candidate.Viable = false; 2493 break; 2494 } 2495 } else { 2496 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2497 // argument for which there is no corresponding parameter is 2498 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2499 Candidate.Conversions[ArgIdx + 1].ConversionKind 2500 = ImplicitConversionSequence::EllipsisConversion; 2501 } 2502 } 2503} 2504 2505/// \brief Add a C++ member function template as a candidate to the candidate 2506/// set, using template argument deduction to produce an appropriate member 2507/// function template specialization. 2508void 2509Sema::AddMethodTemplateCandidate(FunctionTemplateDecl *MethodTmpl, 2510 bool HasExplicitTemplateArgs, 2511 const TemplateArgumentLoc *ExplicitTemplateArgs, 2512 unsigned NumExplicitTemplateArgs, 2513 Expr *Object, Expr **Args, unsigned NumArgs, 2514 OverloadCandidateSet& CandidateSet, 2515 bool SuppressUserConversions, 2516 bool ForceRValue) { 2517 if (!CandidateSet.isNewCandidate(MethodTmpl)) 2518 return; 2519 2520 // C++ [over.match.funcs]p7: 2521 // In each case where a candidate is a function template, candidate 2522 // function template specializations are generated using template argument 2523 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 2524 // candidate functions in the usual way.113) A given name can refer to one 2525 // or more function templates and also to a set of overloaded non-template 2526 // functions. In such a case, the candidate functions generated from each 2527 // function template are combined with the set of non-template candidate 2528 // functions. 2529 TemplateDeductionInfo Info(Context); 2530 FunctionDecl *Specialization = 0; 2531 if (TemplateDeductionResult Result 2532 = DeduceTemplateArguments(MethodTmpl, HasExplicitTemplateArgs, 2533 ExplicitTemplateArgs, NumExplicitTemplateArgs, 2534 Args, NumArgs, Specialization, Info)) { 2535 // FIXME: Record what happened with template argument deduction, so 2536 // that we can give the user a beautiful diagnostic. 2537 (void)Result; 2538 return; 2539 } 2540 2541 // Add the function template specialization produced by template argument 2542 // deduction as a candidate. 2543 assert(Specialization && "Missing member function template specialization?"); 2544 assert(isa<CXXMethodDecl>(Specialization) && 2545 "Specialization is not a member function?"); 2546 AddMethodCandidate(cast<CXXMethodDecl>(Specialization), Object, Args, NumArgs, 2547 CandidateSet, SuppressUserConversions, ForceRValue); 2548} 2549 2550/// \brief Add a C++ function template specialization as a candidate 2551/// in the candidate set, using template argument deduction to produce 2552/// an appropriate function template specialization. 2553void 2554Sema::AddTemplateOverloadCandidate(FunctionTemplateDecl *FunctionTemplate, 2555 bool HasExplicitTemplateArgs, 2556 const TemplateArgumentLoc *ExplicitTemplateArgs, 2557 unsigned NumExplicitTemplateArgs, 2558 Expr **Args, unsigned NumArgs, 2559 OverloadCandidateSet& CandidateSet, 2560 bool SuppressUserConversions, 2561 bool ForceRValue) { 2562 if (!CandidateSet.isNewCandidate(FunctionTemplate)) 2563 return; 2564 2565 // C++ [over.match.funcs]p7: 2566 // In each case where a candidate is a function template, candidate 2567 // function template specializations are generated using template argument 2568 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 2569 // candidate functions in the usual way.113) A given name can refer to one 2570 // or more function templates and also to a set of overloaded non-template 2571 // functions. In such a case, the candidate functions generated from each 2572 // function template are combined with the set of non-template candidate 2573 // functions. 2574 TemplateDeductionInfo Info(Context); 2575 FunctionDecl *Specialization = 0; 2576 if (TemplateDeductionResult Result 2577 = DeduceTemplateArguments(FunctionTemplate, HasExplicitTemplateArgs, 2578 ExplicitTemplateArgs, NumExplicitTemplateArgs, 2579 Args, NumArgs, Specialization, Info)) { 2580 // FIXME: Record what happened with template argument deduction, so 2581 // that we can give the user a beautiful diagnostic. 2582 (void)Result; 2583 return; 2584 } 2585 2586 // Add the function template specialization produced by template argument 2587 // deduction as a candidate. 2588 assert(Specialization && "Missing function template specialization?"); 2589 AddOverloadCandidate(Specialization, Args, NumArgs, CandidateSet, 2590 SuppressUserConversions, ForceRValue); 2591} 2592 2593/// AddConversionCandidate - Add a C++ conversion function as a 2594/// candidate in the candidate set (C++ [over.match.conv], 2595/// C++ [over.match.copy]). From is the expression we're converting from, 2596/// and ToType is the type that we're eventually trying to convert to 2597/// (which may or may not be the same type as the type that the 2598/// conversion function produces). 2599void 2600Sema::AddConversionCandidate(CXXConversionDecl *Conversion, 2601 Expr *From, QualType ToType, 2602 OverloadCandidateSet& CandidateSet) { 2603 assert(!Conversion->getDescribedFunctionTemplate() && 2604 "Conversion function templates use AddTemplateConversionCandidate"); 2605 2606 if (!CandidateSet.isNewCandidate(Conversion)) 2607 return; 2608 2609 // Add this candidate 2610 CandidateSet.push_back(OverloadCandidate()); 2611 OverloadCandidate& Candidate = CandidateSet.back(); 2612 Candidate.Function = Conversion; 2613 Candidate.IsSurrogate = false; 2614 Candidate.IgnoreObjectArgument = false; 2615 Candidate.FinalConversion.setAsIdentityConversion(); 2616 Candidate.FinalConversion.FromTypePtr 2617 = Conversion->getConversionType().getAsOpaquePtr(); 2618 Candidate.FinalConversion.ToTypePtr = ToType.getAsOpaquePtr(); 2619 2620 // Determine the implicit conversion sequence for the implicit 2621 // object parameter. 2622 Candidate.Viable = true; 2623 Candidate.Conversions.resize(1); 2624 Candidate.Conversions[0] = TryObjectArgumentInitialization(From, Conversion); 2625 // Conversion functions to a different type in the base class is visible in 2626 // the derived class. So, a derived to base conversion should not participate 2627 // in overload resolution. 2628 if (Candidate.Conversions[0].Standard.Second == ICK_Derived_To_Base) 2629 Candidate.Conversions[0].Standard.Second = ICK_Identity; 2630 if (Candidate.Conversions[0].ConversionKind 2631 == ImplicitConversionSequence::BadConversion) { 2632 Candidate.Viable = false; 2633 return; 2634 } 2635 2636 // We won't go through a user-define type conversion function to convert a 2637 // derived to base as such conversions are given Conversion Rank. They only 2638 // go through a copy constructor. 13.3.3.1.2-p4 [over.ics.user] 2639 QualType FromCanon 2640 = Context.getCanonicalType(From->getType().getUnqualifiedType()); 2641 QualType ToCanon = Context.getCanonicalType(ToType).getUnqualifiedType(); 2642 if (FromCanon == ToCanon || IsDerivedFrom(FromCanon, ToCanon)) { 2643 Candidate.Viable = false; 2644 return; 2645 } 2646 2647 2648 // To determine what the conversion from the result of calling the 2649 // conversion function to the type we're eventually trying to 2650 // convert to (ToType), we need to synthesize a call to the 2651 // conversion function and attempt copy initialization from it. This 2652 // makes sure that we get the right semantics with respect to 2653 // lvalues/rvalues and the type. Fortunately, we can allocate this 2654 // call on the stack and we don't need its arguments to be 2655 // well-formed. 2656 DeclRefExpr ConversionRef(Conversion, Conversion->getType(), 2657 From->getLocStart()); 2658 ImplicitCastExpr ConversionFn(Context.getPointerType(Conversion->getType()), 2659 CastExpr::CK_FunctionToPointerDecay, 2660 &ConversionRef, false); 2661 2662 // Note that it is safe to allocate CallExpr on the stack here because 2663 // there are 0 arguments (i.e., nothing is allocated using ASTContext's 2664 // allocator). 2665 CallExpr Call(Context, &ConversionFn, 0, 0, 2666 Conversion->getConversionType().getNonReferenceType(), 2667 From->getLocStart()); 2668 ImplicitConversionSequence ICS = 2669 TryCopyInitialization(&Call, ToType, 2670 /*SuppressUserConversions=*/true, 2671 /*ForceRValue=*/false, 2672 /*InOverloadResolution=*/false); 2673 2674 switch (ICS.ConversionKind) { 2675 case ImplicitConversionSequence::StandardConversion: 2676 Candidate.FinalConversion = ICS.Standard; 2677 break; 2678 2679 case ImplicitConversionSequence::BadConversion: 2680 Candidate.Viable = false; 2681 break; 2682 2683 default: 2684 assert(false && 2685 "Can only end up with a standard conversion sequence or failure"); 2686 } 2687} 2688 2689/// \brief Adds a conversion function template specialization 2690/// candidate to the overload set, using template argument deduction 2691/// to deduce the template arguments of the conversion function 2692/// template from the type that we are converting to (C++ 2693/// [temp.deduct.conv]). 2694void 2695Sema::AddTemplateConversionCandidate(FunctionTemplateDecl *FunctionTemplate, 2696 Expr *From, QualType ToType, 2697 OverloadCandidateSet &CandidateSet) { 2698 assert(isa<CXXConversionDecl>(FunctionTemplate->getTemplatedDecl()) && 2699 "Only conversion function templates permitted here"); 2700 2701 if (!CandidateSet.isNewCandidate(FunctionTemplate)) 2702 return; 2703 2704 TemplateDeductionInfo Info(Context); 2705 CXXConversionDecl *Specialization = 0; 2706 if (TemplateDeductionResult Result 2707 = DeduceTemplateArguments(FunctionTemplate, ToType, 2708 Specialization, Info)) { 2709 // FIXME: Record what happened with template argument deduction, so 2710 // that we can give the user a beautiful diagnostic. 2711 (void)Result; 2712 return; 2713 } 2714 2715 // Add the conversion function template specialization produced by 2716 // template argument deduction as a candidate. 2717 assert(Specialization && "Missing function template specialization?"); 2718 AddConversionCandidate(Specialization, From, ToType, CandidateSet); 2719} 2720 2721/// AddSurrogateCandidate - Adds a "surrogate" candidate function that 2722/// converts the given @c Object to a function pointer via the 2723/// conversion function @c Conversion, and then attempts to call it 2724/// with the given arguments (C++ [over.call.object]p2-4). Proto is 2725/// the type of function that we'll eventually be calling. 2726void Sema::AddSurrogateCandidate(CXXConversionDecl *Conversion, 2727 const FunctionProtoType *Proto, 2728 Expr *Object, Expr **Args, unsigned NumArgs, 2729 OverloadCandidateSet& CandidateSet) { 2730 if (!CandidateSet.isNewCandidate(Conversion)) 2731 return; 2732 2733 CandidateSet.push_back(OverloadCandidate()); 2734 OverloadCandidate& Candidate = CandidateSet.back(); 2735 Candidate.Function = 0; 2736 Candidate.Surrogate = Conversion; 2737 Candidate.Viable = true; 2738 Candidate.IsSurrogate = true; 2739 Candidate.IgnoreObjectArgument = false; 2740 Candidate.Conversions.resize(NumArgs + 1); 2741 2742 // Determine the implicit conversion sequence for the implicit 2743 // object parameter. 2744 ImplicitConversionSequence ObjectInit 2745 = TryObjectArgumentInitialization(Object, Conversion); 2746 if (ObjectInit.ConversionKind == ImplicitConversionSequence::BadConversion) { 2747 Candidate.Viable = false; 2748 return; 2749 } 2750 2751 // The first conversion is actually a user-defined conversion whose 2752 // first conversion is ObjectInit's standard conversion (which is 2753 // effectively a reference binding). Record it as such. 2754 Candidate.Conversions[0].ConversionKind 2755 = ImplicitConversionSequence::UserDefinedConversion; 2756 Candidate.Conversions[0].UserDefined.Before = ObjectInit.Standard; 2757 Candidate.Conversions[0].UserDefined.EllipsisConversion = false; 2758 Candidate.Conversions[0].UserDefined.ConversionFunction = Conversion; 2759 Candidate.Conversions[0].UserDefined.After 2760 = Candidate.Conversions[0].UserDefined.Before; 2761 Candidate.Conversions[0].UserDefined.After.setAsIdentityConversion(); 2762 2763 // Find the 2764 unsigned NumArgsInProto = Proto->getNumArgs(); 2765 2766 // (C++ 13.3.2p2): A candidate function having fewer than m 2767 // parameters is viable only if it has an ellipsis in its parameter 2768 // list (8.3.5). 2769 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 2770 Candidate.Viable = false; 2771 return; 2772 } 2773 2774 // Function types don't have any default arguments, so just check if 2775 // we have enough arguments. 2776 if (NumArgs < NumArgsInProto) { 2777 // Not enough arguments. 2778 Candidate.Viable = false; 2779 return; 2780 } 2781 2782 // Determine the implicit conversion sequences for each of the 2783 // arguments. 2784 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2785 if (ArgIdx < NumArgsInProto) { 2786 // (C++ 13.3.2p3): for F to be a viable function, there shall 2787 // exist for each argument an implicit conversion sequence 2788 // (13.3.3.1) that converts that argument to the corresponding 2789 // parameter of F. 2790 QualType ParamType = Proto->getArgType(ArgIdx); 2791 Candidate.Conversions[ArgIdx + 1] 2792 = TryCopyInitialization(Args[ArgIdx], ParamType, 2793 /*SuppressUserConversions=*/false, 2794 /*ForceRValue=*/false, 2795 /*InOverloadResolution=*/false); 2796 if (Candidate.Conversions[ArgIdx + 1].ConversionKind 2797 == ImplicitConversionSequence::BadConversion) { 2798 Candidate.Viable = false; 2799 break; 2800 } 2801 } else { 2802 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2803 // argument for which there is no corresponding parameter is 2804 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2805 Candidate.Conversions[ArgIdx + 1].ConversionKind 2806 = ImplicitConversionSequence::EllipsisConversion; 2807 } 2808 } 2809} 2810 2811// FIXME: This will eventually be removed, once we've migrated all of the 2812// operator overloading logic over to the scheme used by binary operators, which 2813// works for template instantiation. 2814void Sema::AddOperatorCandidates(OverloadedOperatorKind Op, Scope *S, 2815 SourceLocation OpLoc, 2816 Expr **Args, unsigned NumArgs, 2817 OverloadCandidateSet& CandidateSet, 2818 SourceRange OpRange) { 2819 FunctionSet Functions; 2820 2821 QualType T1 = Args[0]->getType(); 2822 QualType T2; 2823 if (NumArgs > 1) 2824 T2 = Args[1]->getType(); 2825 2826 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 2827 if (S) 2828 LookupOverloadedOperatorName(Op, S, T1, T2, Functions); 2829 ArgumentDependentLookup(OpName, /*Operator*/true, Args, NumArgs, Functions); 2830 AddFunctionCandidates(Functions, Args, NumArgs, CandidateSet); 2831 AddMemberOperatorCandidates(Op, OpLoc, Args, NumArgs, CandidateSet, OpRange); 2832 AddBuiltinOperatorCandidates(Op, OpLoc, Args, NumArgs, CandidateSet); 2833} 2834 2835/// \brief Add overload candidates for overloaded operators that are 2836/// member functions. 2837/// 2838/// Add the overloaded operator candidates that are member functions 2839/// for the operator Op that was used in an operator expression such 2840/// as "x Op y". , Args/NumArgs provides the operator arguments, and 2841/// CandidateSet will store the added overload candidates. (C++ 2842/// [over.match.oper]). 2843void Sema::AddMemberOperatorCandidates(OverloadedOperatorKind Op, 2844 SourceLocation OpLoc, 2845 Expr **Args, unsigned NumArgs, 2846 OverloadCandidateSet& CandidateSet, 2847 SourceRange OpRange) { 2848 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 2849 2850 // C++ [over.match.oper]p3: 2851 // For a unary operator @ with an operand of a type whose 2852 // cv-unqualified version is T1, and for a binary operator @ with 2853 // a left operand of a type whose cv-unqualified version is T1 and 2854 // a right operand of a type whose cv-unqualified version is T2, 2855 // three sets of candidate functions, designated member 2856 // candidates, non-member candidates and built-in candidates, are 2857 // constructed as follows: 2858 QualType T1 = Args[0]->getType(); 2859 QualType T2; 2860 if (NumArgs > 1) 2861 T2 = Args[1]->getType(); 2862 2863 // -- If T1 is a class type, the set of member candidates is the 2864 // result of the qualified lookup of T1::operator@ 2865 // (13.3.1.1.1); otherwise, the set of member candidates is 2866 // empty. 2867 if (const RecordType *T1Rec = T1->getAs<RecordType>()) { 2868 // Complete the type if it can be completed. Otherwise, we're done. 2869 if (RequireCompleteType(OpLoc, T1, PDiag())) 2870 return; 2871 2872 LookupResult Operators(*this, OpName, OpLoc, LookupOrdinaryName); 2873 LookupQualifiedName(Operators, T1Rec->getDecl()); 2874 Operators.suppressDiagnostics(); 2875 2876 for (LookupResult::iterator Oper = Operators.begin(), 2877 OperEnd = Operators.end(); 2878 Oper != OperEnd; 2879 ++Oper) 2880 AddMethodCandidate(*Oper, Args[0], Args + 1, NumArgs - 1, CandidateSet, 2881 /* SuppressUserConversions = */ false); 2882 } 2883} 2884 2885/// AddBuiltinCandidate - Add a candidate for a built-in 2886/// operator. ResultTy and ParamTys are the result and parameter types 2887/// of the built-in candidate, respectively. Args and NumArgs are the 2888/// arguments being passed to the candidate. IsAssignmentOperator 2889/// should be true when this built-in candidate is an assignment 2890/// operator. NumContextualBoolArguments is the number of arguments 2891/// (at the beginning of the argument list) that will be contextually 2892/// converted to bool. 2893void Sema::AddBuiltinCandidate(QualType ResultTy, QualType *ParamTys, 2894 Expr **Args, unsigned NumArgs, 2895 OverloadCandidateSet& CandidateSet, 2896 bool IsAssignmentOperator, 2897 unsigned NumContextualBoolArguments) { 2898 // Add this candidate 2899 CandidateSet.push_back(OverloadCandidate()); 2900 OverloadCandidate& Candidate = CandidateSet.back(); 2901 Candidate.Function = 0; 2902 Candidate.IsSurrogate = false; 2903 Candidate.IgnoreObjectArgument = false; 2904 Candidate.BuiltinTypes.ResultTy = ResultTy; 2905 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 2906 Candidate.BuiltinTypes.ParamTypes[ArgIdx] = ParamTys[ArgIdx]; 2907 2908 // Determine the implicit conversion sequences for each of the 2909 // arguments. 2910 Candidate.Viable = true; 2911 Candidate.Conversions.resize(NumArgs); 2912 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2913 // C++ [over.match.oper]p4: 2914 // For the built-in assignment operators, conversions of the 2915 // left operand are restricted as follows: 2916 // -- no temporaries are introduced to hold the left operand, and 2917 // -- no user-defined conversions are applied to the left 2918 // operand to achieve a type match with the left-most 2919 // parameter of a built-in candidate. 2920 // 2921 // We block these conversions by turning off user-defined 2922 // conversions, since that is the only way that initialization of 2923 // a reference to a non-class type can occur from something that 2924 // is not of the same type. 2925 if (ArgIdx < NumContextualBoolArguments) { 2926 assert(ParamTys[ArgIdx] == Context.BoolTy && 2927 "Contextual conversion to bool requires bool type"); 2928 Candidate.Conversions[ArgIdx] = TryContextuallyConvertToBool(Args[ArgIdx]); 2929 } else { 2930 Candidate.Conversions[ArgIdx] 2931 = TryCopyInitialization(Args[ArgIdx], ParamTys[ArgIdx], 2932 ArgIdx == 0 && IsAssignmentOperator, 2933 /*ForceRValue=*/false, 2934 /*InOverloadResolution=*/false); 2935 } 2936 if (Candidate.Conversions[ArgIdx].ConversionKind 2937 == ImplicitConversionSequence::BadConversion) { 2938 Candidate.Viable = false; 2939 break; 2940 } 2941 } 2942} 2943 2944/// BuiltinCandidateTypeSet - A set of types that will be used for the 2945/// candidate operator functions for built-in operators (C++ 2946/// [over.built]). The types are separated into pointer types and 2947/// enumeration types. 2948class BuiltinCandidateTypeSet { 2949 /// TypeSet - A set of types. 2950 typedef llvm::SmallPtrSet<QualType, 8> TypeSet; 2951 2952 /// PointerTypes - The set of pointer types that will be used in the 2953 /// built-in candidates. 2954 TypeSet PointerTypes; 2955 2956 /// MemberPointerTypes - The set of member pointer types that will be 2957 /// used in the built-in candidates. 2958 TypeSet MemberPointerTypes; 2959 2960 /// EnumerationTypes - The set of enumeration types that will be 2961 /// used in the built-in candidates. 2962 TypeSet EnumerationTypes; 2963 2964 /// Sema - The semantic analysis instance where we are building the 2965 /// candidate type set. 2966 Sema &SemaRef; 2967 2968 /// Context - The AST context in which we will build the type sets. 2969 ASTContext &Context; 2970 2971 bool AddPointerWithMoreQualifiedTypeVariants(QualType Ty, 2972 const Qualifiers &VisibleQuals); 2973 bool AddMemberPointerWithMoreQualifiedTypeVariants(QualType Ty); 2974 2975public: 2976 /// iterator - Iterates through the types that are part of the set. 2977 typedef TypeSet::iterator iterator; 2978 2979 BuiltinCandidateTypeSet(Sema &SemaRef) 2980 : SemaRef(SemaRef), Context(SemaRef.Context) { } 2981 2982 void AddTypesConvertedFrom(QualType Ty, 2983 SourceLocation Loc, 2984 bool AllowUserConversions, 2985 bool AllowExplicitConversions, 2986 const Qualifiers &VisibleTypeConversionsQuals); 2987 2988 /// pointer_begin - First pointer type found; 2989 iterator pointer_begin() { return PointerTypes.begin(); } 2990 2991 /// pointer_end - Past the last pointer type found; 2992 iterator pointer_end() { return PointerTypes.end(); } 2993 2994 /// member_pointer_begin - First member pointer type found; 2995 iterator member_pointer_begin() { return MemberPointerTypes.begin(); } 2996 2997 /// member_pointer_end - Past the last member pointer type found; 2998 iterator member_pointer_end() { return MemberPointerTypes.end(); } 2999 3000 /// enumeration_begin - First enumeration type found; 3001 iterator enumeration_begin() { return EnumerationTypes.begin(); } 3002 3003 /// enumeration_end - Past the last enumeration type found; 3004 iterator enumeration_end() { return EnumerationTypes.end(); } 3005}; 3006 3007/// AddPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty to 3008/// the set of pointer types along with any more-qualified variants of 3009/// that type. For example, if @p Ty is "int const *", this routine 3010/// will add "int const *", "int const volatile *", "int const 3011/// restrict *", and "int const volatile restrict *" to the set of 3012/// pointer types. Returns true if the add of @p Ty itself succeeded, 3013/// false otherwise. 3014/// 3015/// FIXME: what to do about extended qualifiers? 3016bool 3017BuiltinCandidateTypeSet::AddPointerWithMoreQualifiedTypeVariants(QualType Ty, 3018 const Qualifiers &VisibleQuals) { 3019 3020 // Insert this type. 3021 if (!PointerTypes.insert(Ty)) 3022 return false; 3023 3024 const PointerType *PointerTy = Ty->getAs<PointerType>(); 3025 assert(PointerTy && "type was not a pointer type!"); 3026 3027 QualType PointeeTy = PointerTy->getPointeeType(); 3028 // Don't add qualified variants of arrays. For one, they're not allowed 3029 // (the qualifier would sink to the element type), and for another, the 3030 // only overload situation where it matters is subscript or pointer +- int, 3031 // and those shouldn't have qualifier variants anyway. 3032 if (PointeeTy->isArrayType()) 3033 return true; 3034 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 3035 if (const ConstantArrayType *Array =Context.getAsConstantArrayType(PointeeTy)) 3036 BaseCVR = Array->getElementType().getCVRQualifiers(); 3037 bool hasVolatile = VisibleQuals.hasVolatile(); 3038 bool hasRestrict = VisibleQuals.hasRestrict(); 3039 3040 // Iterate through all strict supersets of BaseCVR. 3041 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 3042 if ((CVR | BaseCVR) != CVR) continue; 3043 // Skip over Volatile/Restrict if no Volatile/Restrict found anywhere 3044 // in the types. 3045 if ((CVR & Qualifiers::Volatile) && !hasVolatile) continue; 3046 if ((CVR & Qualifiers::Restrict) && !hasRestrict) continue; 3047 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 3048 PointerTypes.insert(Context.getPointerType(QPointeeTy)); 3049 } 3050 3051 return true; 3052} 3053 3054/// AddMemberPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty 3055/// to the set of pointer types along with any more-qualified variants of 3056/// that type. For example, if @p Ty is "int const *", this routine 3057/// will add "int const *", "int const volatile *", "int const 3058/// restrict *", and "int const volatile restrict *" to the set of 3059/// pointer types. Returns true if the add of @p Ty itself succeeded, 3060/// false otherwise. 3061/// 3062/// FIXME: what to do about extended qualifiers? 3063bool 3064BuiltinCandidateTypeSet::AddMemberPointerWithMoreQualifiedTypeVariants( 3065 QualType Ty) { 3066 // Insert this type. 3067 if (!MemberPointerTypes.insert(Ty)) 3068 return false; 3069 3070 const MemberPointerType *PointerTy = Ty->getAs<MemberPointerType>(); 3071 assert(PointerTy && "type was not a member pointer type!"); 3072 3073 QualType PointeeTy = PointerTy->getPointeeType(); 3074 // Don't add qualified variants of arrays. For one, they're not allowed 3075 // (the qualifier would sink to the element type), and for another, the 3076 // only overload situation where it matters is subscript or pointer +- int, 3077 // and those shouldn't have qualifier variants anyway. 3078 if (PointeeTy->isArrayType()) 3079 return true; 3080 const Type *ClassTy = PointerTy->getClass(); 3081 3082 // Iterate through all strict supersets of the pointee type's CVR 3083 // qualifiers. 3084 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 3085 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 3086 if ((CVR | BaseCVR) != CVR) continue; 3087 3088 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 3089 MemberPointerTypes.insert(Context.getMemberPointerType(QPointeeTy, ClassTy)); 3090 } 3091 3092 return true; 3093} 3094 3095/// AddTypesConvertedFrom - Add each of the types to which the type @p 3096/// Ty can be implicit converted to the given set of @p Types. We're 3097/// primarily interested in pointer types and enumeration types. We also 3098/// take member pointer types, for the conditional operator. 3099/// AllowUserConversions is true if we should look at the conversion 3100/// functions of a class type, and AllowExplicitConversions if we 3101/// should also include the explicit conversion functions of a class 3102/// type. 3103void 3104BuiltinCandidateTypeSet::AddTypesConvertedFrom(QualType Ty, 3105 SourceLocation Loc, 3106 bool AllowUserConversions, 3107 bool AllowExplicitConversions, 3108 const Qualifiers &VisibleQuals) { 3109 // Only deal with canonical types. 3110 Ty = Context.getCanonicalType(Ty); 3111 3112 // Look through reference types; they aren't part of the type of an 3113 // expression for the purposes of conversions. 3114 if (const ReferenceType *RefTy = Ty->getAs<ReferenceType>()) 3115 Ty = RefTy->getPointeeType(); 3116 3117 // We don't care about qualifiers on the type. 3118 Ty = Ty.getLocalUnqualifiedType(); 3119 3120 // If we're dealing with an array type, decay to the pointer. 3121 if (Ty->isArrayType()) 3122 Ty = SemaRef.Context.getArrayDecayedType(Ty); 3123 3124 if (const PointerType *PointerTy = Ty->getAs<PointerType>()) { 3125 QualType PointeeTy = PointerTy->getPointeeType(); 3126 3127 // Insert our type, and its more-qualified variants, into the set 3128 // of types. 3129 if (!AddPointerWithMoreQualifiedTypeVariants(Ty, VisibleQuals)) 3130 return; 3131 } else if (Ty->isMemberPointerType()) { 3132 // Member pointers are far easier, since the pointee can't be converted. 3133 if (!AddMemberPointerWithMoreQualifiedTypeVariants(Ty)) 3134 return; 3135 } else if (Ty->isEnumeralType()) { 3136 EnumerationTypes.insert(Ty); 3137 } else if (AllowUserConversions) { 3138 if (const RecordType *TyRec = Ty->getAs<RecordType>()) { 3139 if (SemaRef.RequireCompleteType(Loc, Ty, 0)) { 3140 // No conversion functions in incomplete types. 3141 return; 3142 } 3143 3144 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 3145 OverloadedFunctionDecl *Conversions 3146 = ClassDecl->getVisibleConversionFunctions(); 3147 for (OverloadedFunctionDecl::function_iterator Func 3148 = Conversions->function_begin(); 3149 Func != Conversions->function_end(); ++Func) { 3150 CXXConversionDecl *Conv; 3151 FunctionTemplateDecl *ConvTemplate; 3152 GetFunctionAndTemplate(*Func, Conv, ConvTemplate); 3153 3154 // Skip conversion function templates; they don't tell us anything 3155 // about which builtin types we can convert to. 3156 if (ConvTemplate) 3157 continue; 3158 3159 if (AllowExplicitConversions || !Conv->isExplicit()) { 3160 AddTypesConvertedFrom(Conv->getConversionType(), Loc, false, false, 3161 VisibleQuals); 3162 } 3163 } 3164 } 3165 } 3166} 3167 3168/// \brief Helper function for AddBuiltinOperatorCandidates() that adds 3169/// the volatile- and non-volatile-qualified assignment operators for the 3170/// given type to the candidate set. 3171static void AddBuiltinAssignmentOperatorCandidates(Sema &S, 3172 QualType T, 3173 Expr **Args, 3174 unsigned NumArgs, 3175 OverloadCandidateSet &CandidateSet) { 3176 QualType ParamTypes[2]; 3177 3178 // T& operator=(T&, T) 3179 ParamTypes[0] = S.Context.getLValueReferenceType(T); 3180 ParamTypes[1] = T; 3181 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3182 /*IsAssignmentOperator=*/true); 3183 3184 if (!S.Context.getCanonicalType(T).isVolatileQualified()) { 3185 // volatile T& operator=(volatile T&, T) 3186 ParamTypes[0] 3187 = S.Context.getLValueReferenceType(S.Context.getVolatileType(T)); 3188 ParamTypes[1] = T; 3189 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3190 /*IsAssignmentOperator=*/true); 3191 } 3192} 3193 3194/// CollectVRQualifiers - This routine returns Volatile/Restrict qualifiers, 3195/// if any, found in visible type conversion functions found in ArgExpr's type. 3196static Qualifiers CollectVRQualifiers(ASTContext &Context, Expr* ArgExpr) { 3197 Qualifiers VRQuals; 3198 const RecordType *TyRec; 3199 if (const MemberPointerType *RHSMPType = 3200 ArgExpr->getType()->getAs<MemberPointerType>()) 3201 TyRec = cast<RecordType>(RHSMPType->getClass()); 3202 else 3203 TyRec = ArgExpr->getType()->getAs<RecordType>(); 3204 if (!TyRec) { 3205 // Just to be safe, assume the worst case. 3206 VRQuals.addVolatile(); 3207 VRQuals.addRestrict(); 3208 return VRQuals; 3209 } 3210 3211 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 3212 OverloadedFunctionDecl *Conversions = 3213 ClassDecl->getVisibleConversionFunctions(); 3214 3215 for (OverloadedFunctionDecl::function_iterator Func 3216 = Conversions->function_begin(); 3217 Func != Conversions->function_end(); ++Func) { 3218 if (CXXConversionDecl *Conv = dyn_cast<CXXConversionDecl>(*Func)) { 3219 QualType CanTy = Context.getCanonicalType(Conv->getConversionType()); 3220 if (const ReferenceType *ResTypeRef = CanTy->getAs<ReferenceType>()) 3221 CanTy = ResTypeRef->getPointeeType(); 3222 // Need to go down the pointer/mempointer chain and add qualifiers 3223 // as see them. 3224 bool done = false; 3225 while (!done) { 3226 if (const PointerType *ResTypePtr = CanTy->getAs<PointerType>()) 3227 CanTy = ResTypePtr->getPointeeType(); 3228 else if (const MemberPointerType *ResTypeMPtr = 3229 CanTy->getAs<MemberPointerType>()) 3230 CanTy = ResTypeMPtr->getPointeeType(); 3231 else 3232 done = true; 3233 if (CanTy.isVolatileQualified()) 3234 VRQuals.addVolatile(); 3235 if (CanTy.isRestrictQualified()) 3236 VRQuals.addRestrict(); 3237 if (VRQuals.hasRestrict() && VRQuals.hasVolatile()) 3238 return VRQuals; 3239 } 3240 } 3241 } 3242 return VRQuals; 3243} 3244 3245/// AddBuiltinOperatorCandidates - Add the appropriate built-in 3246/// operator overloads to the candidate set (C++ [over.built]), based 3247/// on the operator @p Op and the arguments given. For example, if the 3248/// operator is a binary '+', this routine might add "int 3249/// operator+(int, int)" to cover integer addition. 3250void 3251Sema::AddBuiltinOperatorCandidates(OverloadedOperatorKind Op, 3252 SourceLocation OpLoc, 3253 Expr **Args, unsigned NumArgs, 3254 OverloadCandidateSet& CandidateSet) { 3255 // The set of "promoted arithmetic types", which are the arithmetic 3256 // types are that preserved by promotion (C++ [over.built]p2). Note 3257 // that the first few of these types are the promoted integral 3258 // types; these types need to be first. 3259 // FIXME: What about complex? 3260 const unsigned FirstIntegralType = 0; 3261 const unsigned LastIntegralType = 13; 3262 const unsigned FirstPromotedIntegralType = 7, 3263 LastPromotedIntegralType = 13; 3264 const unsigned FirstPromotedArithmeticType = 7, 3265 LastPromotedArithmeticType = 16; 3266 const unsigned NumArithmeticTypes = 16; 3267 QualType ArithmeticTypes[NumArithmeticTypes] = { 3268 Context.BoolTy, Context.CharTy, Context.WCharTy, 3269// FIXME: Context.Char16Ty, Context.Char32Ty, 3270 Context.SignedCharTy, Context.ShortTy, 3271 Context.UnsignedCharTy, Context.UnsignedShortTy, 3272 Context.IntTy, Context.LongTy, Context.LongLongTy, 3273 Context.UnsignedIntTy, Context.UnsignedLongTy, Context.UnsignedLongLongTy, 3274 Context.FloatTy, Context.DoubleTy, Context.LongDoubleTy 3275 }; 3276 assert(ArithmeticTypes[FirstPromotedIntegralType] == Context.IntTy && 3277 "Invalid first promoted integral type"); 3278 assert(ArithmeticTypes[LastPromotedIntegralType - 1] 3279 == Context.UnsignedLongLongTy && 3280 "Invalid last promoted integral type"); 3281 assert(ArithmeticTypes[FirstPromotedArithmeticType] == Context.IntTy && 3282 "Invalid first promoted arithmetic type"); 3283 assert(ArithmeticTypes[LastPromotedArithmeticType - 1] 3284 == Context.LongDoubleTy && 3285 "Invalid last promoted arithmetic type"); 3286 3287 // Find all of the types that the arguments can convert to, but only 3288 // if the operator we're looking at has built-in operator candidates 3289 // that make use of these types. 3290 Qualifiers VisibleTypeConversionsQuals; 3291 VisibleTypeConversionsQuals.addConst(); 3292 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 3293 VisibleTypeConversionsQuals += CollectVRQualifiers(Context, Args[ArgIdx]); 3294 3295 BuiltinCandidateTypeSet CandidateTypes(*this); 3296 if (Op == OO_Less || Op == OO_Greater || Op == OO_LessEqual || 3297 Op == OO_GreaterEqual || Op == OO_EqualEqual || Op == OO_ExclaimEqual || 3298 Op == OO_Plus || (Op == OO_Minus && NumArgs == 2) || Op == OO_Equal || 3299 Op == OO_PlusEqual || Op == OO_MinusEqual || Op == OO_Subscript || 3300 Op == OO_ArrowStar || Op == OO_PlusPlus || Op == OO_MinusMinus || 3301 (Op == OO_Star && NumArgs == 1) || Op == OO_Conditional) { 3302 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 3303 CandidateTypes.AddTypesConvertedFrom(Args[ArgIdx]->getType(), 3304 OpLoc, 3305 true, 3306 (Op == OO_Exclaim || 3307 Op == OO_AmpAmp || 3308 Op == OO_PipePipe), 3309 VisibleTypeConversionsQuals); 3310 } 3311 3312 bool isComparison = false; 3313 switch (Op) { 3314 case OO_None: 3315 case NUM_OVERLOADED_OPERATORS: 3316 assert(false && "Expected an overloaded operator"); 3317 break; 3318 3319 case OO_Star: // '*' is either unary or binary 3320 if (NumArgs == 1) 3321 goto UnaryStar; 3322 else 3323 goto BinaryStar; 3324 break; 3325 3326 case OO_Plus: // '+' is either unary or binary 3327 if (NumArgs == 1) 3328 goto UnaryPlus; 3329 else 3330 goto BinaryPlus; 3331 break; 3332 3333 case OO_Minus: // '-' is either unary or binary 3334 if (NumArgs == 1) 3335 goto UnaryMinus; 3336 else 3337 goto BinaryMinus; 3338 break; 3339 3340 case OO_Amp: // '&' is either unary or binary 3341 if (NumArgs == 1) 3342 goto UnaryAmp; 3343 else 3344 goto BinaryAmp; 3345 3346 case OO_PlusPlus: 3347 case OO_MinusMinus: 3348 // C++ [over.built]p3: 3349 // 3350 // For every pair (T, VQ), where T is an arithmetic type, and VQ 3351 // is either volatile or empty, there exist candidate operator 3352 // functions of the form 3353 // 3354 // VQ T& operator++(VQ T&); 3355 // T operator++(VQ T&, int); 3356 // 3357 // C++ [over.built]p4: 3358 // 3359 // For every pair (T, VQ), where T is an arithmetic type other 3360 // than bool, and VQ is either volatile or empty, there exist 3361 // candidate operator functions of the form 3362 // 3363 // VQ T& operator--(VQ T&); 3364 // T operator--(VQ T&, int); 3365 for (unsigned Arith = (Op == OO_PlusPlus? 0 : 1); 3366 Arith < NumArithmeticTypes; ++Arith) { 3367 QualType ArithTy = ArithmeticTypes[Arith]; 3368 QualType ParamTypes[2] 3369 = { Context.getLValueReferenceType(ArithTy), Context.IntTy }; 3370 3371 // Non-volatile version. 3372 if (NumArgs == 1) 3373 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3374 else 3375 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 3376 // heuristic to reduce number of builtin candidates in the set. 3377 // Add volatile version only if there are conversions to a volatile type. 3378 if (VisibleTypeConversionsQuals.hasVolatile()) { 3379 // Volatile version 3380 ParamTypes[0] 3381 = Context.getLValueReferenceType(Context.getVolatileType(ArithTy)); 3382 if (NumArgs == 1) 3383 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3384 else 3385 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 3386 } 3387 } 3388 3389 // C++ [over.built]p5: 3390 // 3391 // For every pair (T, VQ), where T is a cv-qualified or 3392 // cv-unqualified object type, and VQ is either volatile or 3393 // empty, there exist candidate operator functions of the form 3394 // 3395 // T*VQ& operator++(T*VQ&); 3396 // T*VQ& operator--(T*VQ&); 3397 // T* operator++(T*VQ&, int); 3398 // T* operator--(T*VQ&, int); 3399 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3400 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3401 // Skip pointer types that aren't pointers to object types. 3402 if (!(*Ptr)->getAs<PointerType>()->getPointeeType()->isObjectType()) 3403 continue; 3404 3405 QualType ParamTypes[2] = { 3406 Context.getLValueReferenceType(*Ptr), Context.IntTy 3407 }; 3408 3409 // Without volatile 3410 if (NumArgs == 1) 3411 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3412 else 3413 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3414 3415 if (!Context.getCanonicalType(*Ptr).isVolatileQualified() && 3416 VisibleTypeConversionsQuals.hasVolatile()) { 3417 // With volatile 3418 ParamTypes[0] 3419 = Context.getLValueReferenceType(Context.getVolatileType(*Ptr)); 3420 if (NumArgs == 1) 3421 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3422 else 3423 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3424 } 3425 } 3426 break; 3427 3428 UnaryStar: 3429 // C++ [over.built]p6: 3430 // For every cv-qualified or cv-unqualified object type T, there 3431 // exist candidate operator functions of the form 3432 // 3433 // T& operator*(T*); 3434 // 3435 // C++ [over.built]p7: 3436 // For every function type T, there exist candidate operator 3437 // functions of the form 3438 // T& operator*(T*); 3439 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3440 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3441 QualType ParamTy = *Ptr; 3442 QualType PointeeTy = ParamTy->getAs<PointerType>()->getPointeeType(); 3443 AddBuiltinCandidate(Context.getLValueReferenceType(PointeeTy), 3444 &ParamTy, Args, 1, CandidateSet); 3445 } 3446 break; 3447 3448 UnaryPlus: 3449 // C++ [over.built]p8: 3450 // For every type T, there exist candidate operator functions of 3451 // the form 3452 // 3453 // T* operator+(T*); 3454 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3455 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3456 QualType ParamTy = *Ptr; 3457 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet); 3458 } 3459 3460 // Fall through 3461 3462 UnaryMinus: 3463 // C++ [over.built]p9: 3464 // For every promoted arithmetic type T, there exist candidate 3465 // operator functions of the form 3466 // 3467 // T operator+(T); 3468 // T operator-(T); 3469 for (unsigned Arith = FirstPromotedArithmeticType; 3470 Arith < LastPromotedArithmeticType; ++Arith) { 3471 QualType ArithTy = ArithmeticTypes[Arith]; 3472 AddBuiltinCandidate(ArithTy, &ArithTy, Args, 1, CandidateSet); 3473 } 3474 break; 3475 3476 case OO_Tilde: 3477 // C++ [over.built]p10: 3478 // For every promoted integral type T, there exist candidate 3479 // operator functions of the form 3480 // 3481 // T operator~(T); 3482 for (unsigned Int = FirstPromotedIntegralType; 3483 Int < LastPromotedIntegralType; ++Int) { 3484 QualType IntTy = ArithmeticTypes[Int]; 3485 AddBuiltinCandidate(IntTy, &IntTy, Args, 1, CandidateSet); 3486 } 3487 break; 3488 3489 case OO_New: 3490 case OO_Delete: 3491 case OO_Array_New: 3492 case OO_Array_Delete: 3493 case OO_Call: 3494 assert(false && "Special operators don't use AddBuiltinOperatorCandidates"); 3495 break; 3496 3497 case OO_Comma: 3498 UnaryAmp: 3499 case OO_Arrow: 3500 // C++ [over.match.oper]p3: 3501 // -- For the operator ',', the unary operator '&', or the 3502 // operator '->', the built-in candidates set is empty. 3503 break; 3504 3505 case OO_EqualEqual: 3506 case OO_ExclaimEqual: 3507 // C++ [over.match.oper]p16: 3508 // For every pointer to member type T, there exist candidate operator 3509 // functions of the form 3510 // 3511 // bool operator==(T,T); 3512 // bool operator!=(T,T); 3513 for (BuiltinCandidateTypeSet::iterator 3514 MemPtr = CandidateTypes.member_pointer_begin(), 3515 MemPtrEnd = CandidateTypes.member_pointer_end(); 3516 MemPtr != MemPtrEnd; 3517 ++MemPtr) { 3518 QualType ParamTypes[2] = { *MemPtr, *MemPtr }; 3519 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 3520 } 3521 3522 // Fall through 3523 3524 case OO_Less: 3525 case OO_Greater: 3526 case OO_LessEqual: 3527 case OO_GreaterEqual: 3528 // C++ [over.built]p15: 3529 // 3530 // For every pointer or enumeration type T, there exist 3531 // candidate operator functions of the form 3532 // 3533 // bool operator<(T, T); 3534 // bool operator>(T, T); 3535 // bool operator<=(T, T); 3536 // bool operator>=(T, T); 3537 // bool operator==(T, T); 3538 // bool operator!=(T, T); 3539 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3540 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3541 QualType ParamTypes[2] = { *Ptr, *Ptr }; 3542 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 3543 } 3544 for (BuiltinCandidateTypeSet::iterator Enum 3545 = CandidateTypes.enumeration_begin(); 3546 Enum != CandidateTypes.enumeration_end(); ++Enum) { 3547 QualType ParamTypes[2] = { *Enum, *Enum }; 3548 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 3549 } 3550 3551 // Fall through. 3552 isComparison = true; 3553 3554 BinaryPlus: 3555 BinaryMinus: 3556 if (!isComparison) { 3557 // We didn't fall through, so we must have OO_Plus or OO_Minus. 3558 3559 // C++ [over.built]p13: 3560 // 3561 // For every cv-qualified or cv-unqualified object type T 3562 // there exist candidate operator functions of the form 3563 // 3564 // T* operator+(T*, ptrdiff_t); 3565 // T& operator[](T*, ptrdiff_t); [BELOW] 3566 // T* operator-(T*, ptrdiff_t); 3567 // T* operator+(ptrdiff_t, T*); 3568 // T& operator[](ptrdiff_t, T*); [BELOW] 3569 // 3570 // C++ [over.built]p14: 3571 // 3572 // For every T, where T is a pointer to object type, there 3573 // exist candidate operator functions of the form 3574 // 3575 // ptrdiff_t operator-(T, T); 3576 for (BuiltinCandidateTypeSet::iterator Ptr 3577 = CandidateTypes.pointer_begin(); 3578 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3579 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 3580 3581 // operator+(T*, ptrdiff_t) or operator-(T*, ptrdiff_t) 3582 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3583 3584 if (Op == OO_Plus) { 3585 // T* operator+(ptrdiff_t, T*); 3586 ParamTypes[0] = ParamTypes[1]; 3587 ParamTypes[1] = *Ptr; 3588 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3589 } else { 3590 // ptrdiff_t operator-(T, T); 3591 ParamTypes[1] = *Ptr; 3592 AddBuiltinCandidate(Context.getPointerDiffType(), ParamTypes, 3593 Args, 2, CandidateSet); 3594 } 3595 } 3596 } 3597 // Fall through 3598 3599 case OO_Slash: 3600 BinaryStar: 3601 Conditional: 3602 // C++ [over.built]p12: 3603 // 3604 // For every pair of promoted arithmetic types L and R, there 3605 // exist candidate operator functions of the form 3606 // 3607 // LR operator*(L, R); 3608 // LR operator/(L, R); 3609 // LR operator+(L, R); 3610 // LR operator-(L, R); 3611 // bool operator<(L, R); 3612 // bool operator>(L, R); 3613 // bool operator<=(L, R); 3614 // bool operator>=(L, R); 3615 // bool operator==(L, R); 3616 // bool operator!=(L, R); 3617 // 3618 // where LR is the result of the usual arithmetic conversions 3619 // between types L and R. 3620 // 3621 // C++ [over.built]p24: 3622 // 3623 // For every pair of promoted arithmetic types L and R, there exist 3624 // candidate operator functions of the form 3625 // 3626 // LR operator?(bool, L, R); 3627 // 3628 // where LR is the result of the usual arithmetic conversions 3629 // between types L and R. 3630 // Our candidates ignore the first parameter. 3631 for (unsigned Left = FirstPromotedArithmeticType; 3632 Left < LastPromotedArithmeticType; ++Left) { 3633 for (unsigned Right = FirstPromotedArithmeticType; 3634 Right < LastPromotedArithmeticType; ++Right) { 3635 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 3636 QualType Result 3637 = isComparison 3638 ? Context.BoolTy 3639 : Context.UsualArithmeticConversionsType(LandR[0], LandR[1]); 3640 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 3641 } 3642 } 3643 break; 3644 3645 case OO_Percent: 3646 BinaryAmp: 3647 case OO_Caret: 3648 case OO_Pipe: 3649 case OO_LessLess: 3650 case OO_GreaterGreater: 3651 // C++ [over.built]p17: 3652 // 3653 // For every pair of promoted integral types L and R, there 3654 // exist candidate operator functions of the form 3655 // 3656 // LR operator%(L, R); 3657 // LR operator&(L, R); 3658 // LR operator^(L, R); 3659 // LR operator|(L, R); 3660 // L operator<<(L, R); 3661 // L operator>>(L, R); 3662 // 3663 // where LR is the result of the usual arithmetic conversions 3664 // between types L and R. 3665 for (unsigned Left = FirstPromotedIntegralType; 3666 Left < LastPromotedIntegralType; ++Left) { 3667 for (unsigned Right = FirstPromotedIntegralType; 3668 Right < LastPromotedIntegralType; ++Right) { 3669 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 3670 QualType Result = (Op == OO_LessLess || Op == OO_GreaterGreater) 3671 ? LandR[0] 3672 : Context.UsualArithmeticConversionsType(LandR[0], LandR[1]); 3673 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 3674 } 3675 } 3676 break; 3677 3678 case OO_Equal: 3679 // C++ [over.built]p20: 3680 // 3681 // For every pair (T, VQ), where T is an enumeration or 3682 // pointer to member type and VQ is either volatile or 3683 // empty, there exist candidate operator functions of the form 3684 // 3685 // VQ T& operator=(VQ T&, T); 3686 for (BuiltinCandidateTypeSet::iterator 3687 Enum = CandidateTypes.enumeration_begin(), 3688 EnumEnd = CandidateTypes.enumeration_end(); 3689 Enum != EnumEnd; ++Enum) 3690 AddBuiltinAssignmentOperatorCandidates(*this, *Enum, Args, 2, 3691 CandidateSet); 3692 for (BuiltinCandidateTypeSet::iterator 3693 MemPtr = CandidateTypes.member_pointer_begin(), 3694 MemPtrEnd = CandidateTypes.member_pointer_end(); 3695 MemPtr != MemPtrEnd; ++MemPtr) 3696 AddBuiltinAssignmentOperatorCandidates(*this, *MemPtr, Args, 2, 3697 CandidateSet); 3698 // Fall through. 3699 3700 case OO_PlusEqual: 3701 case OO_MinusEqual: 3702 // C++ [over.built]p19: 3703 // 3704 // For every pair (T, VQ), where T is any type and VQ is either 3705 // volatile or empty, there exist candidate operator functions 3706 // of the form 3707 // 3708 // T*VQ& operator=(T*VQ&, T*); 3709 // 3710 // C++ [over.built]p21: 3711 // 3712 // For every pair (T, VQ), where T is a cv-qualified or 3713 // cv-unqualified object type and VQ is either volatile or 3714 // empty, there exist candidate operator functions of the form 3715 // 3716 // T*VQ& operator+=(T*VQ&, ptrdiff_t); 3717 // T*VQ& operator-=(T*VQ&, ptrdiff_t); 3718 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3719 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3720 QualType ParamTypes[2]; 3721 ParamTypes[1] = (Op == OO_Equal)? *Ptr : Context.getPointerDiffType(); 3722 3723 // non-volatile version 3724 ParamTypes[0] = Context.getLValueReferenceType(*Ptr); 3725 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3726 /*IsAssigmentOperator=*/Op == OO_Equal); 3727 3728 if (!Context.getCanonicalType(*Ptr).isVolatileQualified() && 3729 VisibleTypeConversionsQuals.hasVolatile()) { 3730 // volatile version 3731 ParamTypes[0] 3732 = Context.getLValueReferenceType(Context.getVolatileType(*Ptr)); 3733 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3734 /*IsAssigmentOperator=*/Op == OO_Equal); 3735 } 3736 } 3737 // Fall through. 3738 3739 case OO_StarEqual: 3740 case OO_SlashEqual: 3741 // C++ [over.built]p18: 3742 // 3743 // For every triple (L, VQ, R), where L is an arithmetic type, 3744 // VQ is either volatile or empty, and R is a promoted 3745 // arithmetic type, there exist candidate operator functions of 3746 // the form 3747 // 3748 // VQ L& operator=(VQ L&, R); 3749 // VQ L& operator*=(VQ L&, R); 3750 // VQ L& operator/=(VQ L&, R); 3751 // VQ L& operator+=(VQ L&, R); 3752 // VQ L& operator-=(VQ L&, R); 3753 for (unsigned Left = 0; Left < NumArithmeticTypes; ++Left) { 3754 for (unsigned Right = FirstPromotedArithmeticType; 3755 Right < LastPromotedArithmeticType; ++Right) { 3756 QualType ParamTypes[2]; 3757 ParamTypes[1] = ArithmeticTypes[Right]; 3758 3759 // Add this built-in operator as a candidate (VQ is empty). 3760 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 3761 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3762 /*IsAssigmentOperator=*/Op == OO_Equal); 3763 3764 // Add this built-in operator as a candidate (VQ is 'volatile'). 3765 if (VisibleTypeConversionsQuals.hasVolatile()) { 3766 ParamTypes[0] = Context.getVolatileType(ArithmeticTypes[Left]); 3767 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 3768 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3769 /*IsAssigmentOperator=*/Op == OO_Equal); 3770 } 3771 } 3772 } 3773 break; 3774 3775 case OO_PercentEqual: 3776 case OO_LessLessEqual: 3777 case OO_GreaterGreaterEqual: 3778 case OO_AmpEqual: 3779 case OO_CaretEqual: 3780 case OO_PipeEqual: 3781 // C++ [over.built]p22: 3782 // 3783 // For every triple (L, VQ, R), where L is an integral type, VQ 3784 // is either volatile or empty, and R is a promoted integral 3785 // type, there exist candidate operator functions of the form 3786 // 3787 // VQ L& operator%=(VQ L&, R); 3788 // VQ L& operator<<=(VQ L&, R); 3789 // VQ L& operator>>=(VQ L&, R); 3790 // VQ L& operator&=(VQ L&, R); 3791 // VQ L& operator^=(VQ L&, R); 3792 // VQ L& operator|=(VQ L&, R); 3793 for (unsigned Left = FirstIntegralType; Left < LastIntegralType; ++Left) { 3794 for (unsigned Right = FirstPromotedIntegralType; 3795 Right < LastPromotedIntegralType; ++Right) { 3796 QualType ParamTypes[2]; 3797 ParamTypes[1] = ArithmeticTypes[Right]; 3798 3799 // Add this built-in operator as a candidate (VQ is empty). 3800 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 3801 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 3802 if (VisibleTypeConversionsQuals.hasVolatile()) { 3803 // Add this built-in operator as a candidate (VQ is 'volatile'). 3804 ParamTypes[0] = ArithmeticTypes[Left]; 3805 ParamTypes[0] = Context.getVolatileType(ParamTypes[0]); 3806 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 3807 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 3808 } 3809 } 3810 } 3811 break; 3812 3813 case OO_Exclaim: { 3814 // C++ [over.operator]p23: 3815 // 3816 // There also exist candidate operator functions of the form 3817 // 3818 // bool operator!(bool); 3819 // bool operator&&(bool, bool); [BELOW] 3820 // bool operator||(bool, bool); [BELOW] 3821 QualType ParamTy = Context.BoolTy; 3822 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet, 3823 /*IsAssignmentOperator=*/false, 3824 /*NumContextualBoolArguments=*/1); 3825 break; 3826 } 3827 3828 case OO_AmpAmp: 3829 case OO_PipePipe: { 3830 // C++ [over.operator]p23: 3831 // 3832 // There also exist candidate operator functions of the form 3833 // 3834 // bool operator!(bool); [ABOVE] 3835 // bool operator&&(bool, bool); 3836 // bool operator||(bool, bool); 3837 QualType ParamTypes[2] = { Context.BoolTy, Context.BoolTy }; 3838 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet, 3839 /*IsAssignmentOperator=*/false, 3840 /*NumContextualBoolArguments=*/2); 3841 break; 3842 } 3843 3844 case OO_Subscript: 3845 // C++ [over.built]p13: 3846 // 3847 // For every cv-qualified or cv-unqualified object type T there 3848 // exist candidate operator functions of the form 3849 // 3850 // T* operator+(T*, ptrdiff_t); [ABOVE] 3851 // T& operator[](T*, ptrdiff_t); 3852 // T* operator-(T*, ptrdiff_t); [ABOVE] 3853 // T* operator+(ptrdiff_t, T*); [ABOVE] 3854 // T& operator[](ptrdiff_t, T*); 3855 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3856 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3857 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 3858 QualType PointeeType = (*Ptr)->getAs<PointerType>()->getPointeeType(); 3859 QualType ResultTy = Context.getLValueReferenceType(PointeeType); 3860 3861 // T& operator[](T*, ptrdiff_t) 3862 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 3863 3864 // T& operator[](ptrdiff_t, T*); 3865 ParamTypes[0] = ParamTypes[1]; 3866 ParamTypes[1] = *Ptr; 3867 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 3868 } 3869 break; 3870 3871 case OO_ArrowStar: 3872 // C++ [over.built]p11: 3873 // For every quintuple (C1, C2, T, CV1, CV2), where C2 is a class type, 3874 // C1 is the same type as C2 or is a derived class of C2, T is an object 3875 // type or a function type, and CV1 and CV2 are cv-qualifier-seqs, 3876 // there exist candidate operator functions of the form 3877 // CV12 T& operator->*(CV1 C1*, CV2 T C2::*); 3878 // where CV12 is the union of CV1 and CV2. 3879 { 3880 for (BuiltinCandidateTypeSet::iterator Ptr = 3881 CandidateTypes.pointer_begin(); 3882 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3883 QualType C1Ty = (*Ptr); 3884 QualType C1; 3885 QualifierCollector Q1; 3886 if (const PointerType *PointerTy = C1Ty->getAs<PointerType>()) { 3887 C1 = QualType(Q1.strip(PointerTy->getPointeeType()), 0); 3888 if (!isa<RecordType>(C1)) 3889 continue; 3890 // heuristic to reduce number of builtin candidates in the set. 3891 // Add volatile/restrict version only if there are conversions to a 3892 // volatile/restrict type. 3893 if (!VisibleTypeConversionsQuals.hasVolatile() && Q1.hasVolatile()) 3894 continue; 3895 if (!VisibleTypeConversionsQuals.hasRestrict() && Q1.hasRestrict()) 3896 continue; 3897 } 3898 for (BuiltinCandidateTypeSet::iterator 3899 MemPtr = CandidateTypes.member_pointer_begin(), 3900 MemPtrEnd = CandidateTypes.member_pointer_end(); 3901 MemPtr != MemPtrEnd; ++MemPtr) { 3902 const MemberPointerType *mptr = cast<MemberPointerType>(*MemPtr); 3903 QualType C2 = QualType(mptr->getClass(), 0); 3904 C2 = C2.getUnqualifiedType(); 3905 if (C1 != C2 && !IsDerivedFrom(C1, C2)) 3906 break; 3907 QualType ParamTypes[2] = { *Ptr, *MemPtr }; 3908 // build CV12 T& 3909 QualType T = mptr->getPointeeType(); 3910 if (!VisibleTypeConversionsQuals.hasVolatile() && 3911 T.isVolatileQualified()) 3912 continue; 3913 if (!VisibleTypeConversionsQuals.hasRestrict() && 3914 T.isRestrictQualified()) 3915 continue; 3916 T = Q1.apply(T); 3917 QualType ResultTy = Context.getLValueReferenceType(T); 3918 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 3919 } 3920 } 3921 } 3922 break; 3923 3924 case OO_Conditional: 3925 // Note that we don't consider the first argument, since it has been 3926 // contextually converted to bool long ago. The candidates below are 3927 // therefore added as binary. 3928 // 3929 // C++ [over.built]p24: 3930 // For every type T, where T is a pointer or pointer-to-member type, 3931 // there exist candidate operator functions of the form 3932 // 3933 // T operator?(bool, T, T); 3934 // 3935 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(), 3936 E = CandidateTypes.pointer_end(); Ptr != E; ++Ptr) { 3937 QualType ParamTypes[2] = { *Ptr, *Ptr }; 3938 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3939 } 3940 for (BuiltinCandidateTypeSet::iterator Ptr = 3941 CandidateTypes.member_pointer_begin(), 3942 E = CandidateTypes.member_pointer_end(); Ptr != E; ++Ptr) { 3943 QualType ParamTypes[2] = { *Ptr, *Ptr }; 3944 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3945 } 3946 goto Conditional; 3947 } 3948} 3949 3950/// \brief Add function candidates found via argument-dependent lookup 3951/// to the set of overloading candidates. 3952/// 3953/// This routine performs argument-dependent name lookup based on the 3954/// given function name (which may also be an operator name) and adds 3955/// all of the overload candidates found by ADL to the overload 3956/// candidate set (C++ [basic.lookup.argdep]). 3957void 3958Sema::AddArgumentDependentLookupCandidates(DeclarationName Name, 3959 Expr **Args, unsigned NumArgs, 3960 bool HasExplicitTemplateArgs, 3961 const TemplateArgumentLoc *ExplicitTemplateArgs, 3962 unsigned NumExplicitTemplateArgs, 3963 OverloadCandidateSet& CandidateSet, 3964 bool PartialOverloading) { 3965 FunctionSet Functions; 3966 3967 // FIXME: Should we be trafficking in canonical function decls throughout? 3968 3969 // Record all of the function candidates that we've already 3970 // added to the overload set, so that we don't add those same 3971 // candidates a second time. 3972 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 3973 CandEnd = CandidateSet.end(); 3974 Cand != CandEnd; ++Cand) 3975 if (Cand->Function) { 3976 Functions.insert(Cand->Function); 3977 if (FunctionTemplateDecl *FunTmpl = Cand->Function->getPrimaryTemplate()) 3978 Functions.insert(FunTmpl); 3979 } 3980 3981 // FIXME: Pass in the explicit template arguments? 3982 ArgumentDependentLookup(Name, /*Operator*/false, Args, NumArgs, Functions); 3983 3984 // Erase all of the candidates we already knew about. 3985 // FIXME: This is suboptimal. Is there a better way? 3986 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 3987 CandEnd = CandidateSet.end(); 3988 Cand != CandEnd; ++Cand) 3989 if (Cand->Function) { 3990 Functions.erase(Cand->Function); 3991 if (FunctionTemplateDecl *FunTmpl = Cand->Function->getPrimaryTemplate()) 3992 Functions.erase(FunTmpl); 3993 } 3994 3995 // For each of the ADL candidates we found, add it to the overload 3996 // set. 3997 for (FunctionSet::iterator Func = Functions.begin(), 3998 FuncEnd = Functions.end(); 3999 Func != FuncEnd; ++Func) { 4000 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*Func)) { 4001 if (HasExplicitTemplateArgs) 4002 continue; 4003 4004 AddOverloadCandidate(FD, Args, NumArgs, CandidateSet, 4005 false, false, PartialOverloading); 4006 } else 4007 AddTemplateOverloadCandidate(cast<FunctionTemplateDecl>(*Func), 4008 HasExplicitTemplateArgs, 4009 ExplicitTemplateArgs, 4010 NumExplicitTemplateArgs, 4011 Args, NumArgs, CandidateSet); 4012 } 4013} 4014 4015/// isBetterOverloadCandidate - Determines whether the first overload 4016/// candidate is a better candidate than the second (C++ 13.3.3p1). 4017bool 4018Sema::isBetterOverloadCandidate(const OverloadCandidate& Cand1, 4019 const OverloadCandidate& Cand2) { 4020 // Define viable functions to be better candidates than non-viable 4021 // functions. 4022 if (!Cand2.Viable) 4023 return Cand1.Viable; 4024 else if (!Cand1.Viable) 4025 return false; 4026 4027 // C++ [over.match.best]p1: 4028 // 4029 // -- if F is a static member function, ICS1(F) is defined such 4030 // that ICS1(F) is neither better nor worse than ICS1(G) for 4031 // any function G, and, symmetrically, ICS1(G) is neither 4032 // better nor worse than ICS1(F). 4033 unsigned StartArg = 0; 4034 if (Cand1.IgnoreObjectArgument || Cand2.IgnoreObjectArgument) 4035 StartArg = 1; 4036 4037 // C++ [over.match.best]p1: 4038 // A viable function F1 is defined to be a better function than another 4039 // viable function F2 if for all arguments i, ICSi(F1) is not a worse 4040 // conversion sequence than ICSi(F2), and then... 4041 unsigned NumArgs = Cand1.Conversions.size(); 4042 assert(Cand2.Conversions.size() == NumArgs && "Overload candidate mismatch"); 4043 bool HasBetterConversion = false; 4044 for (unsigned ArgIdx = StartArg; ArgIdx < NumArgs; ++ArgIdx) { 4045 switch (CompareImplicitConversionSequences(Cand1.Conversions[ArgIdx], 4046 Cand2.Conversions[ArgIdx])) { 4047 case ImplicitConversionSequence::Better: 4048 // Cand1 has a better conversion sequence. 4049 HasBetterConversion = true; 4050 break; 4051 4052 case ImplicitConversionSequence::Worse: 4053 // Cand1 can't be better than Cand2. 4054 return false; 4055 4056 case ImplicitConversionSequence::Indistinguishable: 4057 // Do nothing. 4058 break; 4059 } 4060 } 4061 4062 // -- for some argument j, ICSj(F1) is a better conversion sequence than 4063 // ICSj(F2), or, if not that, 4064 if (HasBetterConversion) 4065 return true; 4066 4067 // - F1 is a non-template function and F2 is a function template 4068 // specialization, or, if not that, 4069 if (Cand1.Function && !Cand1.Function->getPrimaryTemplate() && 4070 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 4071 return true; 4072 4073 // -- F1 and F2 are function template specializations, and the function 4074 // template for F1 is more specialized than the template for F2 4075 // according to the partial ordering rules described in 14.5.5.2, or, 4076 // if not that, 4077 if (Cand1.Function && Cand1.Function->getPrimaryTemplate() && 4078 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 4079 if (FunctionTemplateDecl *BetterTemplate 4080 = getMoreSpecializedTemplate(Cand1.Function->getPrimaryTemplate(), 4081 Cand2.Function->getPrimaryTemplate(), 4082 isa<CXXConversionDecl>(Cand1.Function)? TPOC_Conversion 4083 : TPOC_Call)) 4084 return BetterTemplate == Cand1.Function->getPrimaryTemplate(); 4085 4086 // -- the context is an initialization by user-defined conversion 4087 // (see 8.5, 13.3.1.5) and the standard conversion sequence 4088 // from the return type of F1 to the destination type (i.e., 4089 // the type of the entity being initialized) is a better 4090 // conversion sequence than the standard conversion sequence 4091 // from the return type of F2 to the destination type. 4092 if (Cand1.Function && Cand2.Function && 4093 isa<CXXConversionDecl>(Cand1.Function) && 4094 isa<CXXConversionDecl>(Cand2.Function)) { 4095 switch (CompareStandardConversionSequences(Cand1.FinalConversion, 4096 Cand2.FinalConversion)) { 4097 case ImplicitConversionSequence::Better: 4098 // Cand1 has a better conversion sequence. 4099 return true; 4100 4101 case ImplicitConversionSequence::Worse: 4102 // Cand1 can't be better than Cand2. 4103 return false; 4104 4105 case ImplicitConversionSequence::Indistinguishable: 4106 // Do nothing 4107 break; 4108 } 4109 } 4110 4111 return false; 4112} 4113 4114/// \brief Computes the best viable function (C++ 13.3.3) 4115/// within an overload candidate set. 4116/// 4117/// \param CandidateSet the set of candidate functions. 4118/// 4119/// \param Loc the location of the function name (or operator symbol) for 4120/// which overload resolution occurs. 4121/// 4122/// \param Best f overload resolution was successful or found a deleted 4123/// function, Best points to the candidate function found. 4124/// 4125/// \returns The result of overload resolution. 4126Sema::OverloadingResult 4127Sema::BestViableFunction(OverloadCandidateSet& CandidateSet, 4128 SourceLocation Loc, 4129 OverloadCandidateSet::iterator& Best) { 4130 // Find the best viable function. 4131 Best = CandidateSet.end(); 4132 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 4133 Cand != CandidateSet.end(); ++Cand) { 4134 if (Cand->Viable) { 4135 if (Best == CandidateSet.end() || isBetterOverloadCandidate(*Cand, *Best)) 4136 Best = Cand; 4137 } 4138 } 4139 4140 // If we didn't find any viable functions, abort. 4141 if (Best == CandidateSet.end()) 4142 return OR_No_Viable_Function; 4143 4144 // Make sure that this function is better than every other viable 4145 // function. If not, we have an ambiguity. 4146 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 4147 Cand != CandidateSet.end(); ++Cand) { 4148 if (Cand->Viable && 4149 Cand != Best && 4150 !isBetterOverloadCandidate(*Best, *Cand)) { 4151 Best = CandidateSet.end(); 4152 return OR_Ambiguous; 4153 } 4154 } 4155 4156 // Best is the best viable function. 4157 if (Best->Function && 4158 (Best->Function->isDeleted() || 4159 Best->Function->getAttr<UnavailableAttr>())) 4160 return OR_Deleted; 4161 4162 // C++ [basic.def.odr]p2: 4163 // An overloaded function is used if it is selected by overload resolution 4164 // when referred to from a potentially-evaluated expression. [Note: this 4165 // covers calls to named functions (5.2.2), operator overloading 4166 // (clause 13), user-defined conversions (12.3.2), allocation function for 4167 // placement new (5.3.4), as well as non-default initialization (8.5). 4168 if (Best->Function) 4169 MarkDeclarationReferenced(Loc, Best->Function); 4170 return OR_Success; 4171} 4172 4173/// PrintOverloadCandidates - When overload resolution fails, prints 4174/// diagnostic messages containing the candidates in the candidate 4175/// set. If OnlyViable is true, only viable candidates will be printed. 4176void 4177Sema::PrintOverloadCandidates(OverloadCandidateSet& CandidateSet, 4178 bool OnlyViable, 4179 const char *Opc, 4180 SourceLocation OpLoc) { 4181 OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 4182 LastCand = CandidateSet.end(); 4183 bool Reported = false; 4184 for (; Cand != LastCand; ++Cand) { 4185 if (Cand->Viable || !OnlyViable) { 4186 if (Cand->Function) { 4187 if (Cand->Function->isDeleted() || 4188 Cand->Function->getAttr<UnavailableAttr>()) { 4189 // Deleted or "unavailable" function. 4190 Diag(Cand->Function->getLocation(), diag::err_ovl_candidate_deleted) 4191 << Cand->Function->isDeleted(); 4192 } else if (FunctionTemplateDecl *FunTmpl 4193 = Cand->Function->getPrimaryTemplate()) { 4194 // Function template specialization 4195 // FIXME: Give a better reason! 4196 Diag(Cand->Function->getLocation(), diag::err_ovl_template_candidate) 4197 << getTemplateArgumentBindingsText(FunTmpl->getTemplateParameters(), 4198 *Cand->Function->getTemplateSpecializationArgs()); 4199 } else { 4200 // Normal function 4201 bool errReported = false; 4202 if (!Cand->Viable && Cand->Conversions.size() > 0) { 4203 for (int i = Cand->Conversions.size()-1; i >= 0; i--) { 4204 const ImplicitConversionSequence &Conversion = 4205 Cand->Conversions[i]; 4206 if ((Conversion.ConversionKind != 4207 ImplicitConversionSequence::BadConversion) || 4208 Conversion.ConversionFunctionSet.size() == 0) 4209 continue; 4210 Diag(Cand->Function->getLocation(), 4211 diag::err_ovl_candidate_not_viable) << (i+1); 4212 errReported = true; 4213 for (int j = Conversion.ConversionFunctionSet.size()-1; 4214 j >= 0; j--) { 4215 FunctionDecl *Func = Conversion.ConversionFunctionSet[j]; 4216 Diag(Func->getLocation(), diag::err_ovl_candidate); 4217 } 4218 } 4219 } 4220 if (!errReported) 4221 Diag(Cand->Function->getLocation(), diag::err_ovl_candidate); 4222 } 4223 } else if (Cand->IsSurrogate) { 4224 // Desugar the type of the surrogate down to a function type, 4225 // retaining as many typedefs as possible while still showing 4226 // the function type (and, therefore, its parameter types). 4227 QualType FnType = Cand->Surrogate->getConversionType(); 4228 bool isLValueReference = false; 4229 bool isRValueReference = false; 4230 bool isPointer = false; 4231 if (const LValueReferenceType *FnTypeRef = 4232 FnType->getAs<LValueReferenceType>()) { 4233 FnType = FnTypeRef->getPointeeType(); 4234 isLValueReference = true; 4235 } else if (const RValueReferenceType *FnTypeRef = 4236 FnType->getAs<RValueReferenceType>()) { 4237 FnType = FnTypeRef->getPointeeType(); 4238 isRValueReference = true; 4239 } 4240 if (const PointerType *FnTypePtr = FnType->getAs<PointerType>()) { 4241 FnType = FnTypePtr->getPointeeType(); 4242 isPointer = true; 4243 } 4244 // Desugar down to a function type. 4245 FnType = QualType(FnType->getAs<FunctionType>(), 0); 4246 // Reconstruct the pointer/reference as appropriate. 4247 if (isPointer) FnType = Context.getPointerType(FnType); 4248 if (isRValueReference) FnType = Context.getRValueReferenceType(FnType); 4249 if (isLValueReference) FnType = Context.getLValueReferenceType(FnType); 4250 4251 Diag(Cand->Surrogate->getLocation(), diag::err_ovl_surrogate_cand) 4252 << FnType; 4253 } else if (OnlyViable) { 4254 assert(Cand->Conversions.size() <= 2 && 4255 "builtin-binary-operator-not-binary"); 4256 std::string TypeStr("operator"); 4257 TypeStr += Opc; 4258 TypeStr += "("; 4259 TypeStr += Cand->BuiltinTypes.ParamTypes[0].getAsString(); 4260 if (Cand->Conversions.size() == 1) { 4261 TypeStr += ")"; 4262 Diag(OpLoc, diag::err_ovl_builtin_unary_candidate) << TypeStr; 4263 } 4264 else { 4265 TypeStr += ", "; 4266 TypeStr += Cand->BuiltinTypes.ParamTypes[1].getAsString(); 4267 TypeStr += ")"; 4268 Diag(OpLoc, diag::err_ovl_builtin_binary_candidate) << TypeStr; 4269 } 4270 } 4271 else if (!Cand->Viable && !Reported) { 4272 // Non-viability might be due to ambiguous user-defined conversions, 4273 // needed for built-in operators. Report them as well, but only once 4274 // as we have typically many built-in candidates. 4275 unsigned NoOperands = Cand->Conversions.size(); 4276 for (unsigned ArgIdx = 0; ArgIdx < NoOperands; ++ArgIdx) { 4277 const ImplicitConversionSequence &ICS = Cand->Conversions[ArgIdx]; 4278 if (ICS.ConversionKind != ImplicitConversionSequence::BadConversion || 4279 ICS.ConversionFunctionSet.empty()) 4280 continue; 4281 if (CXXConversionDecl *Func = dyn_cast<CXXConversionDecl>( 4282 Cand->Conversions[ArgIdx].ConversionFunctionSet[0])) { 4283 QualType FromTy = 4284 QualType( 4285 static_cast<Type*>(ICS.UserDefined.Before.FromTypePtr),0); 4286 Diag(OpLoc,diag::note_ambiguous_type_conversion) 4287 << FromTy << Func->getConversionType(); 4288 } 4289 for (unsigned j = 0; j < ICS.ConversionFunctionSet.size(); j++) { 4290 FunctionDecl *Func = 4291 Cand->Conversions[ArgIdx].ConversionFunctionSet[j]; 4292 Diag(Func->getLocation(),diag::err_ovl_candidate); 4293 } 4294 } 4295 Reported = true; 4296 } 4297 } 4298 } 4299} 4300 4301/// ResolveAddressOfOverloadedFunction - Try to resolve the address of 4302/// an overloaded function (C++ [over.over]), where @p From is an 4303/// expression with overloaded function type and @p ToType is the type 4304/// we're trying to resolve to. For example: 4305/// 4306/// @code 4307/// int f(double); 4308/// int f(int); 4309/// 4310/// int (*pfd)(double) = f; // selects f(double) 4311/// @endcode 4312/// 4313/// This routine returns the resulting FunctionDecl if it could be 4314/// resolved, and NULL otherwise. When @p Complain is true, this 4315/// routine will emit diagnostics if there is an error. 4316FunctionDecl * 4317Sema::ResolveAddressOfOverloadedFunction(Expr *From, QualType ToType, 4318 bool Complain) { 4319 QualType FunctionType = ToType; 4320 bool IsMember = false; 4321 if (const PointerType *ToTypePtr = ToType->getAs<PointerType>()) 4322 FunctionType = ToTypePtr->getPointeeType(); 4323 else if (const ReferenceType *ToTypeRef = ToType->getAs<ReferenceType>()) 4324 FunctionType = ToTypeRef->getPointeeType(); 4325 else if (const MemberPointerType *MemTypePtr = 4326 ToType->getAs<MemberPointerType>()) { 4327 FunctionType = MemTypePtr->getPointeeType(); 4328 IsMember = true; 4329 } 4330 4331 // We only look at pointers or references to functions. 4332 FunctionType = Context.getCanonicalType(FunctionType).getUnqualifiedType(); 4333 if (!FunctionType->isFunctionType()) 4334 return 0; 4335 4336 // Find the actual overloaded function declaration. 4337 OverloadedFunctionDecl *Ovl = 0; 4338 4339 // C++ [over.over]p1: 4340 // [...] [Note: any redundant set of parentheses surrounding the 4341 // overloaded function name is ignored (5.1). ] 4342 Expr *OvlExpr = From->IgnoreParens(); 4343 4344 // C++ [over.over]p1: 4345 // [...] The overloaded function name can be preceded by the & 4346 // operator. 4347 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(OvlExpr)) { 4348 if (UnOp->getOpcode() == UnaryOperator::AddrOf) 4349 OvlExpr = UnOp->getSubExpr()->IgnoreParens(); 4350 } 4351 4352 bool HasExplicitTemplateArgs = false; 4353 const TemplateArgumentLoc *ExplicitTemplateArgs = 0; 4354 unsigned NumExplicitTemplateArgs = 0; 4355 4356 // Try to dig out the overloaded function. 4357 FunctionTemplateDecl *FunctionTemplate = 0; 4358 if (DeclRefExpr *DR = dyn_cast<DeclRefExpr>(OvlExpr)) { 4359 Ovl = dyn_cast<OverloadedFunctionDecl>(DR->getDecl()); 4360 FunctionTemplate = dyn_cast<FunctionTemplateDecl>(DR->getDecl()); 4361 HasExplicitTemplateArgs = DR->hasExplicitTemplateArgumentList(); 4362 ExplicitTemplateArgs = DR->getTemplateArgs(); 4363 NumExplicitTemplateArgs = DR->getNumTemplateArgs(); 4364 } else if (MemberExpr *ME = dyn_cast<MemberExpr>(OvlExpr)) { 4365 Ovl = dyn_cast<OverloadedFunctionDecl>(ME->getMemberDecl()); 4366 FunctionTemplate = dyn_cast<FunctionTemplateDecl>(ME->getMemberDecl()); 4367 HasExplicitTemplateArgs = ME->hasExplicitTemplateArgumentList(); 4368 ExplicitTemplateArgs = ME->getTemplateArgs(); 4369 NumExplicitTemplateArgs = ME->getNumTemplateArgs(); 4370 } else if (TemplateIdRefExpr *TIRE = dyn_cast<TemplateIdRefExpr>(OvlExpr)) { 4371 TemplateName Name = TIRE->getTemplateName(); 4372 Ovl = Name.getAsOverloadedFunctionDecl(); 4373 FunctionTemplate = 4374 dyn_cast_or_null<FunctionTemplateDecl>(Name.getAsTemplateDecl()); 4375 4376 HasExplicitTemplateArgs = true; 4377 ExplicitTemplateArgs = TIRE->getTemplateArgs(); 4378 NumExplicitTemplateArgs = TIRE->getNumTemplateArgs(); 4379 } 4380 4381 // If there's no overloaded function declaration or function template, 4382 // we're done. 4383 if (!Ovl && !FunctionTemplate) 4384 return 0; 4385 4386 OverloadIterator Fun; 4387 if (Ovl) 4388 Fun = Ovl; 4389 else 4390 Fun = FunctionTemplate; 4391 4392 // Look through all of the overloaded functions, searching for one 4393 // whose type matches exactly. 4394 llvm::SmallPtrSet<FunctionDecl *, 4> Matches; 4395 bool FoundNonTemplateFunction = false; 4396 for (OverloadIterator FunEnd; Fun != FunEnd; ++Fun) { 4397 // C++ [over.over]p3: 4398 // Non-member functions and static member functions match 4399 // targets of type "pointer-to-function" or "reference-to-function." 4400 // Nonstatic member functions match targets of 4401 // type "pointer-to-member-function." 4402 // Note that according to DR 247, the containing class does not matter. 4403 4404 if (FunctionTemplateDecl *FunctionTemplate 4405 = dyn_cast<FunctionTemplateDecl>(*Fun)) { 4406 if (CXXMethodDecl *Method 4407 = dyn_cast<CXXMethodDecl>(FunctionTemplate->getTemplatedDecl())) { 4408 // Skip non-static function templates when converting to pointer, and 4409 // static when converting to member pointer. 4410 if (Method->isStatic() == IsMember) 4411 continue; 4412 } else if (IsMember) 4413 continue; 4414 4415 // C++ [over.over]p2: 4416 // If the name is a function template, template argument deduction is 4417 // done (14.8.2.2), and if the argument deduction succeeds, the 4418 // resulting template argument list is used to generate a single 4419 // function template specialization, which is added to the set of 4420 // overloaded functions considered. 4421 // FIXME: We don't really want to build the specialization here, do we? 4422 FunctionDecl *Specialization = 0; 4423 TemplateDeductionInfo Info(Context); 4424 if (TemplateDeductionResult Result 4425 = DeduceTemplateArguments(FunctionTemplate, HasExplicitTemplateArgs, 4426 ExplicitTemplateArgs, 4427 NumExplicitTemplateArgs, 4428 FunctionType, Specialization, Info)) { 4429 // FIXME: make a note of the failed deduction for diagnostics. 4430 (void)Result; 4431 } else { 4432 // FIXME: If the match isn't exact, shouldn't we just drop this as 4433 // a candidate? Find a testcase before changing the code. 4434 assert(FunctionType 4435 == Context.getCanonicalType(Specialization->getType())); 4436 Matches.insert( 4437 cast<FunctionDecl>(Specialization->getCanonicalDecl())); 4438 } 4439 } 4440 4441 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(*Fun)) { 4442 // Skip non-static functions when converting to pointer, and static 4443 // when converting to member pointer. 4444 if (Method->isStatic() == IsMember) 4445 continue; 4446 4447 // If we have explicit template arguments, skip non-templates. 4448 if (HasExplicitTemplateArgs) 4449 continue; 4450 } else if (IsMember) 4451 continue; 4452 4453 if (FunctionDecl *FunDecl = dyn_cast<FunctionDecl>(*Fun)) { 4454 if (FunctionType == Context.getCanonicalType(FunDecl->getType())) { 4455 Matches.insert(cast<FunctionDecl>(Fun->getCanonicalDecl())); 4456 FoundNonTemplateFunction = true; 4457 } 4458 } 4459 } 4460 4461 // If there were 0 or 1 matches, we're done. 4462 if (Matches.empty()) 4463 return 0; 4464 else if (Matches.size() == 1) { 4465 FunctionDecl *Result = *Matches.begin(); 4466 MarkDeclarationReferenced(From->getLocStart(), Result); 4467 return Result; 4468 } 4469 4470 // C++ [over.over]p4: 4471 // If more than one function is selected, [...] 4472 typedef llvm::SmallPtrSet<FunctionDecl *, 4>::iterator MatchIter; 4473 if (!FoundNonTemplateFunction) { 4474 // [...] and any given function template specialization F1 is 4475 // eliminated if the set contains a second function template 4476 // specialization whose function template is more specialized 4477 // than the function template of F1 according to the partial 4478 // ordering rules of 14.5.5.2. 4479 4480 // The algorithm specified above is quadratic. We instead use a 4481 // two-pass algorithm (similar to the one used to identify the 4482 // best viable function in an overload set) that identifies the 4483 // best function template (if it exists). 4484 llvm::SmallVector<FunctionDecl *, 8> TemplateMatches(Matches.begin(), 4485 Matches.end()); 4486 FunctionDecl *Result = 4487 getMostSpecialized(TemplateMatches.data(), TemplateMatches.size(), 4488 TPOC_Other, From->getLocStart(), 4489 PDiag(), 4490 PDiag(diag::err_addr_ovl_ambiguous) 4491 << TemplateMatches[0]->getDeclName(), 4492 PDiag(diag::err_ovl_template_candidate)); 4493 MarkDeclarationReferenced(From->getLocStart(), Result); 4494 return Result; 4495 } 4496 4497 // [...] any function template specializations in the set are 4498 // eliminated if the set also contains a non-template function, [...] 4499 llvm::SmallVector<FunctionDecl *, 4> RemainingMatches; 4500 for (MatchIter M = Matches.begin(), MEnd = Matches.end(); M != MEnd; ++M) 4501 if ((*M)->getPrimaryTemplate() == 0) 4502 RemainingMatches.push_back(*M); 4503 4504 // [...] After such eliminations, if any, there shall remain exactly one 4505 // selected function. 4506 if (RemainingMatches.size() == 1) { 4507 FunctionDecl *Result = RemainingMatches.front(); 4508 MarkDeclarationReferenced(From->getLocStart(), Result); 4509 return Result; 4510 } 4511 4512 // FIXME: We should probably return the same thing that BestViableFunction 4513 // returns (even if we issue the diagnostics here). 4514 Diag(From->getLocStart(), diag::err_addr_ovl_ambiguous) 4515 << RemainingMatches[0]->getDeclName(); 4516 for (unsigned I = 0, N = RemainingMatches.size(); I != N; ++I) 4517 Diag(RemainingMatches[I]->getLocation(), diag::err_ovl_candidate); 4518 return 0; 4519} 4520 4521/// \brief Add a single candidate to the overload set. 4522static void AddOverloadedCallCandidate(Sema &S, 4523 AnyFunctionDecl Callee, 4524 bool &ArgumentDependentLookup, 4525 bool HasExplicitTemplateArgs, 4526 const TemplateArgumentLoc *ExplicitTemplateArgs, 4527 unsigned NumExplicitTemplateArgs, 4528 Expr **Args, unsigned NumArgs, 4529 OverloadCandidateSet &CandidateSet, 4530 bool PartialOverloading) { 4531 if (FunctionDecl *Func = dyn_cast<FunctionDecl>(Callee)) { 4532 assert(!HasExplicitTemplateArgs && "Explicit template arguments?"); 4533 S.AddOverloadCandidate(Func, Args, NumArgs, CandidateSet, false, false, 4534 PartialOverloading); 4535 4536 if (Func->getDeclContext()->isRecord() || 4537 Func->getDeclContext()->isFunctionOrMethod()) 4538 ArgumentDependentLookup = false; 4539 return; 4540 } 4541 4542 FunctionTemplateDecl *FuncTemplate = cast<FunctionTemplateDecl>(Callee); 4543 S.AddTemplateOverloadCandidate(FuncTemplate, HasExplicitTemplateArgs, 4544 ExplicitTemplateArgs, 4545 NumExplicitTemplateArgs, 4546 Args, NumArgs, CandidateSet); 4547 4548 if (FuncTemplate->getDeclContext()->isRecord()) 4549 ArgumentDependentLookup = false; 4550} 4551 4552/// \brief Add the overload candidates named by callee and/or found by argument 4553/// dependent lookup to the given overload set. 4554void Sema::AddOverloadedCallCandidates(NamedDecl *Callee, 4555 DeclarationName &UnqualifiedName, 4556 bool &ArgumentDependentLookup, 4557 bool HasExplicitTemplateArgs, 4558 const TemplateArgumentLoc *ExplicitTemplateArgs, 4559 unsigned NumExplicitTemplateArgs, 4560 Expr **Args, unsigned NumArgs, 4561 OverloadCandidateSet &CandidateSet, 4562 bool PartialOverloading) { 4563 // Add the functions denoted by Callee to the set of candidate 4564 // functions. While we're doing so, track whether argument-dependent 4565 // lookup still applies, per: 4566 // 4567 // C++0x [basic.lookup.argdep]p3: 4568 // Let X be the lookup set produced by unqualified lookup (3.4.1) 4569 // and let Y be the lookup set produced by argument dependent 4570 // lookup (defined as follows). If X contains 4571 // 4572 // -- a declaration of a class member, or 4573 // 4574 // -- a block-scope function declaration that is not a 4575 // using-declaration (FIXME: check for using declaration), or 4576 // 4577 // -- a declaration that is neither a function or a function 4578 // template 4579 // 4580 // then Y is empty. 4581 if (!Callee) { 4582 // Nothing to do. 4583 } else if (OverloadedFunctionDecl *Ovl 4584 = dyn_cast<OverloadedFunctionDecl>(Callee)) { 4585 for (OverloadedFunctionDecl::function_iterator Func = Ovl->function_begin(), 4586 FuncEnd = Ovl->function_end(); 4587 Func != FuncEnd; ++Func) 4588 AddOverloadedCallCandidate(*this, *Func, ArgumentDependentLookup, 4589 HasExplicitTemplateArgs, 4590 ExplicitTemplateArgs, NumExplicitTemplateArgs, 4591 Args, NumArgs, CandidateSet, 4592 PartialOverloading); 4593 } else if (isa<FunctionDecl>(Callee) || isa<FunctionTemplateDecl>(Callee)) 4594 AddOverloadedCallCandidate(*this, 4595 AnyFunctionDecl::getFromNamedDecl(Callee), 4596 ArgumentDependentLookup, 4597 HasExplicitTemplateArgs, 4598 ExplicitTemplateArgs, NumExplicitTemplateArgs, 4599 Args, NumArgs, CandidateSet, 4600 PartialOverloading); 4601 // FIXME: assert isa<FunctionDecl> || isa<FunctionTemplateDecl> rather than 4602 // checking dynamically. 4603 4604 if (Callee) 4605 UnqualifiedName = Callee->getDeclName(); 4606 4607 if (ArgumentDependentLookup) 4608 AddArgumentDependentLookupCandidates(UnqualifiedName, Args, NumArgs, 4609 HasExplicitTemplateArgs, 4610 ExplicitTemplateArgs, 4611 NumExplicitTemplateArgs, 4612 CandidateSet, 4613 PartialOverloading); 4614} 4615 4616/// ResolveOverloadedCallFn - Given the call expression that calls Fn 4617/// (which eventually refers to the declaration Func) and the call 4618/// arguments Args/NumArgs, attempt to resolve the function call down 4619/// to a specific function. If overload resolution succeeds, returns 4620/// the function declaration produced by overload 4621/// resolution. Otherwise, emits diagnostics, deletes all of the 4622/// arguments and Fn, and returns NULL. 4623FunctionDecl *Sema::ResolveOverloadedCallFn(Expr *Fn, NamedDecl *Callee, 4624 DeclarationName UnqualifiedName, 4625 bool HasExplicitTemplateArgs, 4626 const TemplateArgumentLoc *ExplicitTemplateArgs, 4627 unsigned NumExplicitTemplateArgs, 4628 SourceLocation LParenLoc, 4629 Expr **Args, unsigned NumArgs, 4630 SourceLocation *CommaLocs, 4631 SourceLocation RParenLoc, 4632 bool &ArgumentDependentLookup) { 4633 OverloadCandidateSet CandidateSet; 4634 4635 // Add the functions denoted by Callee to the set of candidate 4636 // functions. 4637 AddOverloadedCallCandidates(Callee, UnqualifiedName, ArgumentDependentLookup, 4638 HasExplicitTemplateArgs, ExplicitTemplateArgs, 4639 NumExplicitTemplateArgs, Args, NumArgs, 4640 CandidateSet); 4641 OverloadCandidateSet::iterator Best; 4642 switch (BestViableFunction(CandidateSet, Fn->getLocStart(), Best)) { 4643 case OR_Success: 4644 return Best->Function; 4645 4646 case OR_No_Viable_Function: 4647 Diag(Fn->getSourceRange().getBegin(), 4648 diag::err_ovl_no_viable_function_in_call) 4649 << UnqualifiedName << Fn->getSourceRange(); 4650 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4651 break; 4652 4653 case OR_Ambiguous: 4654 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_ambiguous_call) 4655 << UnqualifiedName << Fn->getSourceRange(); 4656 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4657 break; 4658 4659 case OR_Deleted: 4660 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_deleted_call) 4661 << Best->Function->isDeleted() 4662 << UnqualifiedName 4663 << Fn->getSourceRange(); 4664 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4665 break; 4666 } 4667 4668 // Overload resolution failed. Destroy all of the subexpressions and 4669 // return NULL. 4670 Fn->Destroy(Context); 4671 for (unsigned Arg = 0; Arg < NumArgs; ++Arg) 4672 Args[Arg]->Destroy(Context); 4673 return 0; 4674} 4675 4676/// \brief Create a unary operation that may resolve to an overloaded 4677/// operator. 4678/// 4679/// \param OpLoc The location of the operator itself (e.g., '*'). 4680/// 4681/// \param OpcIn The UnaryOperator::Opcode that describes this 4682/// operator. 4683/// 4684/// \param Functions The set of non-member functions that will be 4685/// considered by overload resolution. The caller needs to build this 4686/// set based on the context using, e.g., 4687/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 4688/// set should not contain any member functions; those will be added 4689/// by CreateOverloadedUnaryOp(). 4690/// 4691/// \param input The input argument. 4692Sema::OwningExprResult Sema::CreateOverloadedUnaryOp(SourceLocation OpLoc, 4693 unsigned OpcIn, 4694 FunctionSet &Functions, 4695 ExprArg input) { 4696 UnaryOperator::Opcode Opc = static_cast<UnaryOperator::Opcode>(OpcIn); 4697 Expr *Input = (Expr *)input.get(); 4698 4699 OverloadedOperatorKind Op = UnaryOperator::getOverloadedOperator(Opc); 4700 assert(Op != OO_None && "Invalid opcode for overloaded unary operator"); 4701 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 4702 4703 Expr *Args[2] = { Input, 0 }; 4704 unsigned NumArgs = 1; 4705 4706 // For post-increment and post-decrement, add the implicit '0' as 4707 // the second argument, so that we know this is a post-increment or 4708 // post-decrement. 4709 if (Opc == UnaryOperator::PostInc || Opc == UnaryOperator::PostDec) { 4710 llvm::APSInt Zero(Context.getTypeSize(Context.IntTy), false); 4711 Args[1] = new (Context) IntegerLiteral(Zero, Context.IntTy, 4712 SourceLocation()); 4713 NumArgs = 2; 4714 } 4715 4716 if (Input->isTypeDependent()) { 4717 OverloadedFunctionDecl *Overloads 4718 = OverloadedFunctionDecl::Create(Context, CurContext, OpName); 4719 for (FunctionSet::iterator Func = Functions.begin(), 4720 FuncEnd = Functions.end(); 4721 Func != FuncEnd; ++Func) 4722 Overloads->addOverload(*Func); 4723 4724 DeclRefExpr *Fn = new (Context) DeclRefExpr(Overloads, Context.OverloadTy, 4725 OpLoc, false, false); 4726 4727 input.release(); 4728 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 4729 &Args[0], NumArgs, 4730 Context.DependentTy, 4731 OpLoc)); 4732 } 4733 4734 // Build an empty overload set. 4735 OverloadCandidateSet CandidateSet; 4736 4737 // Add the candidates from the given function set. 4738 AddFunctionCandidates(Functions, &Args[0], NumArgs, CandidateSet, false); 4739 4740 // Add operator candidates that are member functions. 4741 AddMemberOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 4742 4743 // Add builtin operator candidates. 4744 AddBuiltinOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 4745 4746 // Perform overload resolution. 4747 OverloadCandidateSet::iterator Best; 4748 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 4749 case OR_Success: { 4750 // We found a built-in operator or an overloaded operator. 4751 FunctionDecl *FnDecl = Best->Function; 4752 4753 if (FnDecl) { 4754 // We matched an overloaded operator. Build a call to that 4755 // operator. 4756 4757 // Convert the arguments. 4758 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 4759 if (PerformObjectArgumentInitialization(Input, Method)) 4760 return ExprError(); 4761 } else { 4762 // Convert the arguments. 4763 if (PerformCopyInitialization(Input, 4764 FnDecl->getParamDecl(0)->getType(), 4765 "passing")) 4766 return ExprError(); 4767 } 4768 4769 // Determine the result type 4770 QualType ResultTy = FnDecl->getResultType().getNonReferenceType(); 4771 4772 // Build the actual expression node. 4773 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 4774 SourceLocation()); 4775 UsualUnaryConversions(FnExpr); 4776 4777 input.release(); 4778 Args[0] = Input; 4779 ExprOwningPtr<CallExpr> TheCall(this, 4780 new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 4781 Args, NumArgs, ResultTy, OpLoc)); 4782 4783 if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall.get(), 4784 FnDecl)) 4785 return ExprError(); 4786 4787 return MaybeBindToTemporary(TheCall.release()); 4788 } else { 4789 // We matched a built-in operator. Convert the arguments, then 4790 // break out so that we will build the appropriate built-in 4791 // operator node. 4792 if (PerformImplicitConversion(Input, Best->BuiltinTypes.ParamTypes[0], 4793 Best->Conversions[0], "passing")) 4794 return ExprError(); 4795 4796 break; 4797 } 4798 } 4799 4800 case OR_No_Viable_Function: 4801 // No viable function; fall through to handling this as a 4802 // built-in operator, which will produce an error message for us. 4803 break; 4804 4805 case OR_Ambiguous: 4806 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 4807 << UnaryOperator::getOpcodeStr(Opc) 4808 << Input->getSourceRange(); 4809 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true, 4810 UnaryOperator::getOpcodeStr(Opc), OpLoc); 4811 return ExprError(); 4812 4813 case OR_Deleted: 4814 Diag(OpLoc, diag::err_ovl_deleted_oper) 4815 << Best->Function->isDeleted() 4816 << UnaryOperator::getOpcodeStr(Opc) 4817 << Input->getSourceRange(); 4818 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4819 return ExprError(); 4820 } 4821 4822 // Either we found no viable overloaded operator or we matched a 4823 // built-in operator. In either case, fall through to trying to 4824 // build a built-in operation. 4825 input.release(); 4826 return CreateBuiltinUnaryOp(OpLoc, Opc, Owned(Input)); 4827} 4828 4829/// \brief Create a binary operation that may resolve to an overloaded 4830/// operator. 4831/// 4832/// \param OpLoc The location of the operator itself (e.g., '+'). 4833/// 4834/// \param OpcIn The BinaryOperator::Opcode that describes this 4835/// operator. 4836/// 4837/// \param Functions The set of non-member functions that will be 4838/// considered by overload resolution. The caller needs to build this 4839/// set based on the context using, e.g., 4840/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 4841/// set should not contain any member functions; those will be added 4842/// by CreateOverloadedBinOp(). 4843/// 4844/// \param LHS Left-hand argument. 4845/// \param RHS Right-hand argument. 4846Sema::OwningExprResult 4847Sema::CreateOverloadedBinOp(SourceLocation OpLoc, 4848 unsigned OpcIn, 4849 FunctionSet &Functions, 4850 Expr *LHS, Expr *RHS) { 4851 Expr *Args[2] = { LHS, RHS }; 4852 LHS=RHS=0; //Please use only Args instead of LHS/RHS couple 4853 4854 BinaryOperator::Opcode Opc = static_cast<BinaryOperator::Opcode>(OpcIn); 4855 OverloadedOperatorKind Op = BinaryOperator::getOverloadedOperator(Opc); 4856 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 4857 4858 // If either side is type-dependent, create an appropriate dependent 4859 // expression. 4860 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 4861 if (Functions.empty()) { 4862 // If there are no functions to store, just build a dependent 4863 // BinaryOperator or CompoundAssignment. 4864 if (Opc <= BinaryOperator::Assign || Opc > BinaryOperator::OrAssign) 4865 return Owned(new (Context) BinaryOperator(Args[0], Args[1], Opc, 4866 Context.DependentTy, OpLoc)); 4867 4868 return Owned(new (Context) CompoundAssignOperator(Args[0], Args[1], Opc, 4869 Context.DependentTy, 4870 Context.DependentTy, 4871 Context.DependentTy, 4872 OpLoc)); 4873 } 4874 4875 OverloadedFunctionDecl *Overloads 4876 = OverloadedFunctionDecl::Create(Context, CurContext, OpName); 4877 for (FunctionSet::iterator Func = Functions.begin(), 4878 FuncEnd = Functions.end(); 4879 Func != FuncEnd; ++Func) 4880 Overloads->addOverload(*Func); 4881 4882 DeclRefExpr *Fn = new (Context) DeclRefExpr(Overloads, Context.OverloadTy, 4883 OpLoc, false, false); 4884 4885 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 4886 Args, 2, 4887 Context.DependentTy, 4888 OpLoc)); 4889 } 4890 4891 // If this is the .* operator, which is not overloadable, just 4892 // create a built-in binary operator. 4893 if (Opc == BinaryOperator::PtrMemD) 4894 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 4895 4896 // If this is one of the assignment operators, we only perform 4897 // overload resolution if the left-hand side is a class or 4898 // enumeration type (C++ [expr.ass]p3). 4899 if (Opc >= BinaryOperator::Assign && Opc <= BinaryOperator::OrAssign && 4900 !Args[0]->getType()->isOverloadableType()) 4901 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 4902 4903 // Build an empty overload set. 4904 OverloadCandidateSet CandidateSet; 4905 4906 // Add the candidates from the given function set. 4907 AddFunctionCandidates(Functions, Args, 2, CandidateSet, false); 4908 4909 // Add operator candidates that are member functions. 4910 AddMemberOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 4911 4912 // Add builtin operator candidates. 4913 AddBuiltinOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 4914 4915 // Perform overload resolution. 4916 OverloadCandidateSet::iterator Best; 4917 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 4918 case OR_Success: { 4919 // We found a built-in operator or an overloaded operator. 4920 FunctionDecl *FnDecl = Best->Function; 4921 4922 if (FnDecl) { 4923 // We matched an overloaded operator. Build a call to that 4924 // operator. 4925 4926 // Convert the arguments. 4927 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 4928 if (PerformObjectArgumentInitialization(Args[0], Method) || 4929 PerformCopyInitialization(Args[1], FnDecl->getParamDecl(0)->getType(), 4930 "passing")) 4931 return ExprError(); 4932 } else { 4933 // Convert the arguments. 4934 if (PerformCopyInitialization(Args[0], FnDecl->getParamDecl(0)->getType(), 4935 "passing") || 4936 PerformCopyInitialization(Args[1], FnDecl->getParamDecl(1)->getType(), 4937 "passing")) 4938 return ExprError(); 4939 } 4940 4941 // Determine the result type 4942 QualType ResultTy 4943 = FnDecl->getType()->getAs<FunctionType>()->getResultType(); 4944 ResultTy = ResultTy.getNonReferenceType(); 4945 4946 // Build the actual expression node. 4947 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 4948 OpLoc); 4949 UsualUnaryConversions(FnExpr); 4950 4951 ExprOwningPtr<CXXOperatorCallExpr> 4952 TheCall(this, new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 4953 Args, 2, ResultTy, 4954 OpLoc)); 4955 4956 if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall.get(), 4957 FnDecl)) 4958 return ExprError(); 4959 4960 return MaybeBindToTemporary(TheCall.release()); 4961 } else { 4962 // We matched a built-in operator. Convert the arguments, then 4963 // break out so that we will build the appropriate built-in 4964 // operator node. 4965 if (PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 4966 Best->Conversions[0], "passing") || 4967 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 4968 Best->Conversions[1], "passing")) 4969 return ExprError(); 4970 4971 break; 4972 } 4973 } 4974 4975 case OR_No_Viable_Function: { 4976 // C++ [over.match.oper]p9: 4977 // If the operator is the operator , [...] and there are no 4978 // viable functions, then the operator is assumed to be the 4979 // built-in operator and interpreted according to clause 5. 4980 if (Opc == BinaryOperator::Comma) 4981 break; 4982 4983 // For class as left operand for assignment or compound assigment operator 4984 // do not fall through to handling in built-in, but report that no overloaded 4985 // assignment operator found 4986 OwningExprResult Result = ExprError(); 4987 if (Args[0]->getType()->isRecordType() && 4988 Opc >= BinaryOperator::Assign && Opc <= BinaryOperator::OrAssign) { 4989 Diag(OpLoc, diag::err_ovl_no_viable_oper) 4990 << BinaryOperator::getOpcodeStr(Opc) 4991 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 4992 } else { 4993 // No viable function; try to create a built-in operation, which will 4994 // produce an error. Then, show the non-viable candidates. 4995 Result = CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 4996 } 4997 assert(Result.isInvalid() && 4998 "C++ binary operator overloading is missing candidates!"); 4999 if (Result.isInvalid()) 5000 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false, 5001 BinaryOperator::getOpcodeStr(Opc), OpLoc); 5002 return move(Result); 5003 } 5004 5005 case OR_Ambiguous: 5006 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 5007 << BinaryOperator::getOpcodeStr(Opc) 5008 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 5009 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true, 5010 BinaryOperator::getOpcodeStr(Opc), OpLoc); 5011 return ExprError(); 5012 5013 case OR_Deleted: 5014 Diag(OpLoc, diag::err_ovl_deleted_oper) 5015 << Best->Function->isDeleted() 5016 << BinaryOperator::getOpcodeStr(Opc) 5017 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 5018 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 5019 return ExprError(); 5020 } 5021 5022 // We matched a built-in operator; build it. 5023 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 5024} 5025 5026Action::OwningExprResult 5027Sema::CreateOverloadedArraySubscriptExpr(SourceLocation LLoc, 5028 SourceLocation RLoc, 5029 ExprArg Base, ExprArg Idx) { 5030 Expr *Args[2] = { static_cast<Expr*>(Base.get()), 5031 static_cast<Expr*>(Idx.get()) }; 5032 DeclarationName OpName = 5033 Context.DeclarationNames.getCXXOperatorName(OO_Subscript); 5034 5035 // If either side is type-dependent, create an appropriate dependent 5036 // expression. 5037 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 5038 5039 OverloadedFunctionDecl *Overloads 5040 = OverloadedFunctionDecl::Create(Context, CurContext, OpName); 5041 5042 DeclRefExpr *Fn = new (Context) DeclRefExpr(Overloads, Context.OverloadTy, 5043 LLoc, false, false); 5044 5045 Base.release(); 5046 Idx.release(); 5047 return Owned(new (Context) CXXOperatorCallExpr(Context, OO_Subscript, Fn, 5048 Args, 2, 5049 Context.DependentTy, 5050 RLoc)); 5051 } 5052 5053 // Build an empty overload set. 5054 OverloadCandidateSet CandidateSet; 5055 5056 // Subscript can only be overloaded as a member function. 5057 5058 // Add operator candidates that are member functions. 5059 AddMemberOperatorCandidates(OO_Subscript, LLoc, Args, 2, CandidateSet); 5060 5061 // Add builtin operator candidates. 5062 AddBuiltinOperatorCandidates(OO_Subscript, LLoc, Args, 2, CandidateSet); 5063 5064 // Perform overload resolution. 5065 OverloadCandidateSet::iterator Best; 5066 switch (BestViableFunction(CandidateSet, LLoc, Best)) { 5067 case OR_Success: { 5068 // We found a built-in operator or an overloaded operator. 5069 FunctionDecl *FnDecl = Best->Function; 5070 5071 if (FnDecl) { 5072 // We matched an overloaded operator. Build a call to that 5073 // operator. 5074 5075 // Convert the arguments. 5076 CXXMethodDecl *Method = cast<CXXMethodDecl>(FnDecl); 5077 if (PerformObjectArgumentInitialization(Args[0], Method) || 5078 PerformCopyInitialization(Args[1], 5079 FnDecl->getParamDecl(0)->getType(), 5080 "passing")) 5081 return ExprError(); 5082 5083 // Determine the result type 5084 QualType ResultTy 5085 = FnDecl->getType()->getAs<FunctionType>()->getResultType(); 5086 ResultTy = ResultTy.getNonReferenceType(); 5087 5088 // Build the actual expression node. 5089 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 5090 LLoc); 5091 UsualUnaryConversions(FnExpr); 5092 5093 Base.release(); 5094 Idx.release(); 5095 ExprOwningPtr<CXXOperatorCallExpr> 5096 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Subscript, 5097 FnExpr, Args, 2, 5098 ResultTy, RLoc)); 5099 5100 if (CheckCallReturnType(FnDecl->getResultType(), LLoc, TheCall.get(), 5101 FnDecl)) 5102 return ExprError(); 5103 5104 return MaybeBindToTemporary(TheCall.release()); 5105 } else { 5106 // We matched a built-in operator. Convert the arguments, then 5107 // break out so that we will build the appropriate built-in 5108 // operator node. 5109 if (PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 5110 Best->Conversions[0], "passing") || 5111 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 5112 Best->Conversions[1], "passing")) 5113 return ExprError(); 5114 5115 break; 5116 } 5117 } 5118 5119 case OR_No_Viable_Function: { 5120 // No viable function; try to create a built-in operation, which will 5121 // produce an error. Then, show the non-viable candidates. 5122 OwningExprResult Result = 5123 CreateBuiltinArraySubscriptExpr(move(Base), LLoc, move(Idx), RLoc); 5124 assert(Result.isInvalid() && 5125 "C++ subscript operator overloading is missing candidates!"); 5126 if (Result.isInvalid()) 5127 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false, 5128 "[]", LLoc); 5129 return move(Result); 5130 } 5131 5132 case OR_Ambiguous: 5133 Diag(LLoc, diag::err_ovl_ambiguous_oper) 5134 << "[]" << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 5135 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true, 5136 "[]", LLoc); 5137 return ExprError(); 5138 5139 case OR_Deleted: 5140 Diag(LLoc, diag::err_ovl_deleted_oper) 5141 << Best->Function->isDeleted() << "[]" 5142 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 5143 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 5144 return ExprError(); 5145 } 5146 5147 // We matched a built-in operator; build it. 5148 Base.release(); 5149 Idx.release(); 5150 return CreateBuiltinArraySubscriptExpr(Owned(Args[0]), LLoc, 5151 Owned(Args[1]), RLoc); 5152} 5153 5154/// BuildCallToMemberFunction - Build a call to a member 5155/// function. MemExpr is the expression that refers to the member 5156/// function (and includes the object parameter), Args/NumArgs are the 5157/// arguments to the function call (not including the object 5158/// parameter). The caller needs to validate that the member 5159/// expression refers to a member function or an overloaded member 5160/// function. 5161Sema::ExprResult 5162Sema::BuildCallToMemberFunction(Scope *S, Expr *MemExprE, 5163 SourceLocation LParenLoc, Expr **Args, 5164 unsigned NumArgs, SourceLocation *CommaLocs, 5165 SourceLocation RParenLoc) { 5166 // Dig out the member expression. This holds both the object 5167 // argument and the member function we're referring to. 5168 MemberExpr *MemExpr = 0; 5169 if (ParenExpr *ParenE = dyn_cast<ParenExpr>(MemExprE)) 5170 MemExpr = dyn_cast<MemberExpr>(ParenE->getSubExpr()); 5171 else 5172 MemExpr = dyn_cast<MemberExpr>(MemExprE); 5173 assert(MemExpr && "Building member call without member expression"); 5174 5175 // Extract the object argument. 5176 Expr *ObjectArg = MemExpr->getBase(); 5177 5178 CXXMethodDecl *Method = 0; 5179 if (isa<OverloadedFunctionDecl>(MemExpr->getMemberDecl()) || 5180 isa<FunctionTemplateDecl>(MemExpr->getMemberDecl())) { 5181 // Add overload candidates 5182 OverloadCandidateSet CandidateSet; 5183 DeclarationName DeclName = MemExpr->getMemberDecl()->getDeclName(); 5184 5185 for (OverloadIterator Func(MemExpr->getMemberDecl()), FuncEnd; 5186 Func != FuncEnd; ++Func) { 5187 if ((Method = dyn_cast<CXXMethodDecl>(*Func))) { 5188 // If explicit template arguments were provided, we can't call a 5189 // non-template member function. 5190 if (MemExpr->hasExplicitTemplateArgumentList()) 5191 continue; 5192 5193 AddMethodCandidate(Method, ObjectArg, Args, NumArgs, CandidateSet, 5194 /*SuppressUserConversions=*/false); 5195 } else 5196 AddMethodTemplateCandidate(cast<FunctionTemplateDecl>(*Func), 5197 MemExpr->hasExplicitTemplateArgumentList(), 5198 MemExpr->getTemplateArgs(), 5199 MemExpr->getNumTemplateArgs(), 5200 ObjectArg, Args, NumArgs, 5201 CandidateSet, 5202 /*SuppressUsedConversions=*/false); 5203 } 5204 5205 OverloadCandidateSet::iterator Best; 5206 switch (BestViableFunction(CandidateSet, MemExpr->getLocStart(), Best)) { 5207 case OR_Success: 5208 Method = cast<CXXMethodDecl>(Best->Function); 5209 break; 5210 5211 case OR_No_Viable_Function: 5212 Diag(MemExpr->getSourceRange().getBegin(), 5213 diag::err_ovl_no_viable_member_function_in_call) 5214 << DeclName << MemExprE->getSourceRange(); 5215 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 5216 // FIXME: Leaking incoming expressions! 5217 return true; 5218 5219 case OR_Ambiguous: 5220 Diag(MemExpr->getSourceRange().getBegin(), 5221 diag::err_ovl_ambiguous_member_call) 5222 << DeclName << MemExprE->getSourceRange(); 5223 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 5224 // FIXME: Leaking incoming expressions! 5225 return true; 5226 5227 case OR_Deleted: 5228 Diag(MemExpr->getSourceRange().getBegin(), 5229 diag::err_ovl_deleted_member_call) 5230 << Best->Function->isDeleted() 5231 << DeclName << MemExprE->getSourceRange(); 5232 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 5233 // FIXME: Leaking incoming expressions! 5234 return true; 5235 } 5236 5237 FixOverloadedFunctionReference(MemExpr, Method); 5238 } else { 5239 Method = dyn_cast<CXXMethodDecl>(MemExpr->getMemberDecl()); 5240 } 5241 5242 assert(Method && "Member call to something that isn't a method?"); 5243 ExprOwningPtr<CXXMemberCallExpr> 5244 TheCall(this, new (Context) CXXMemberCallExpr(Context, MemExpr, Args, 5245 NumArgs, 5246 Method->getResultType().getNonReferenceType(), 5247 RParenLoc)); 5248 5249 // Check for a valid return type. 5250 if (CheckCallReturnType(Method->getResultType(), MemExpr->getMemberLoc(), 5251 TheCall.get(), Method)) 5252 return true; 5253 5254 // Convert the object argument (for a non-static member function call). 5255 if (!Method->isStatic() && 5256 PerformObjectArgumentInitialization(ObjectArg, Method)) 5257 return true; 5258 MemExpr->setBase(ObjectArg); 5259 5260 // Convert the rest of the arguments 5261 const FunctionProtoType *Proto = cast<FunctionProtoType>(Method->getType()); 5262 if (ConvertArgumentsForCall(&*TheCall, MemExpr, Method, Proto, Args, NumArgs, 5263 RParenLoc)) 5264 return true; 5265 5266 if (CheckFunctionCall(Method, TheCall.get())) 5267 return true; 5268 5269 return MaybeBindToTemporary(TheCall.release()).release(); 5270} 5271 5272/// BuildCallToObjectOfClassType - Build a call to an object of class 5273/// type (C++ [over.call.object]), which can end up invoking an 5274/// overloaded function call operator (@c operator()) or performing a 5275/// user-defined conversion on the object argument. 5276Sema::ExprResult 5277Sema::BuildCallToObjectOfClassType(Scope *S, Expr *Object, 5278 SourceLocation LParenLoc, 5279 Expr **Args, unsigned NumArgs, 5280 SourceLocation *CommaLocs, 5281 SourceLocation RParenLoc) { 5282 assert(Object->getType()->isRecordType() && "Requires object type argument"); 5283 const RecordType *Record = Object->getType()->getAs<RecordType>(); 5284 5285 // C++ [over.call.object]p1: 5286 // If the primary-expression E in the function call syntax 5287 // evaluates to a class object of type "cv T", then the set of 5288 // candidate functions includes at least the function call 5289 // operators of T. The function call operators of T are obtained by 5290 // ordinary lookup of the name operator() in the context of 5291 // (E).operator(). 5292 OverloadCandidateSet CandidateSet; 5293 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Call); 5294 5295 if (RequireCompleteType(LParenLoc, Object->getType(), 5296 PartialDiagnostic(diag::err_incomplete_object_call) 5297 << Object->getSourceRange())) 5298 return true; 5299 5300 LookupResult R(*this, OpName, LParenLoc, LookupOrdinaryName); 5301 LookupQualifiedName(R, Record->getDecl()); 5302 R.suppressDiagnostics(); 5303 5304 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 5305 Oper != OperEnd; ++Oper) { 5306 AddMethodCandidate(*Oper, Object, Args, NumArgs, CandidateSet, 5307 /*SuppressUserConversions=*/ false); 5308 } 5309 5310 // C++ [over.call.object]p2: 5311 // In addition, for each conversion function declared in T of the 5312 // form 5313 // 5314 // operator conversion-type-id () cv-qualifier; 5315 // 5316 // where cv-qualifier is the same cv-qualification as, or a 5317 // greater cv-qualification than, cv, and where conversion-type-id 5318 // denotes the type "pointer to function of (P1,...,Pn) returning 5319 // R", or the type "reference to pointer to function of 5320 // (P1,...,Pn) returning R", or the type "reference to function 5321 // of (P1,...,Pn) returning R", a surrogate call function [...] 5322 // is also considered as a candidate function. Similarly, 5323 // surrogate call functions are added to the set of candidate 5324 // functions for each conversion function declared in an 5325 // accessible base class provided the function is not hidden 5326 // within T by another intervening declaration. 5327 // FIXME: Look in base classes for more conversion operators! 5328 OverloadedFunctionDecl *Conversions 5329 = cast<CXXRecordDecl>(Record->getDecl())->getConversionFunctions(); 5330 for (OverloadedFunctionDecl::function_iterator 5331 Func = Conversions->function_begin(), 5332 FuncEnd = Conversions->function_end(); 5333 Func != FuncEnd; ++Func) { 5334 CXXConversionDecl *Conv; 5335 FunctionTemplateDecl *ConvTemplate; 5336 GetFunctionAndTemplate(*Func, Conv, ConvTemplate); 5337 5338 // Skip over templated conversion functions; they aren't 5339 // surrogates. 5340 if (ConvTemplate) 5341 continue; 5342 5343 // Strip the reference type (if any) and then the pointer type (if 5344 // any) to get down to what might be a function type. 5345 QualType ConvType = Conv->getConversionType().getNonReferenceType(); 5346 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 5347 ConvType = ConvPtrType->getPointeeType(); 5348 5349 if (const FunctionProtoType *Proto = ConvType->getAs<FunctionProtoType>()) 5350 AddSurrogateCandidate(Conv, Proto, Object, Args, NumArgs, CandidateSet); 5351 } 5352 5353 // Perform overload resolution. 5354 OverloadCandidateSet::iterator Best; 5355 switch (BestViableFunction(CandidateSet, Object->getLocStart(), Best)) { 5356 case OR_Success: 5357 // Overload resolution succeeded; we'll build the appropriate call 5358 // below. 5359 break; 5360 5361 case OR_No_Viable_Function: 5362 Diag(Object->getSourceRange().getBegin(), 5363 diag::err_ovl_no_viable_object_call) 5364 << Object->getType() << Object->getSourceRange(); 5365 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 5366 break; 5367 5368 case OR_Ambiguous: 5369 Diag(Object->getSourceRange().getBegin(), 5370 diag::err_ovl_ambiguous_object_call) 5371 << Object->getType() << Object->getSourceRange(); 5372 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 5373 break; 5374 5375 case OR_Deleted: 5376 Diag(Object->getSourceRange().getBegin(), 5377 diag::err_ovl_deleted_object_call) 5378 << Best->Function->isDeleted() 5379 << Object->getType() << Object->getSourceRange(); 5380 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 5381 break; 5382 } 5383 5384 if (Best == CandidateSet.end()) { 5385 // We had an error; delete all of the subexpressions and return 5386 // the error. 5387 Object->Destroy(Context); 5388 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 5389 Args[ArgIdx]->Destroy(Context); 5390 return true; 5391 } 5392 5393 if (Best->Function == 0) { 5394 // Since there is no function declaration, this is one of the 5395 // surrogate candidates. Dig out the conversion function. 5396 CXXConversionDecl *Conv 5397 = cast<CXXConversionDecl>( 5398 Best->Conversions[0].UserDefined.ConversionFunction); 5399 5400 // We selected one of the surrogate functions that converts the 5401 // object parameter to a function pointer. Perform the conversion 5402 // on the object argument, then let ActOnCallExpr finish the job. 5403 5404 // Create an implicit member expr to refer to the conversion operator. 5405 // and then call it. 5406 CXXMemberCallExpr *CE = 5407 BuildCXXMemberCallExpr(Object, Conv); 5408 5409 return ActOnCallExpr(S, ExprArg(*this, CE), LParenLoc, 5410 MultiExprArg(*this, (ExprTy**)Args, NumArgs), 5411 CommaLocs, RParenLoc).release(); 5412 } 5413 5414 // We found an overloaded operator(). Build a CXXOperatorCallExpr 5415 // that calls this method, using Object for the implicit object 5416 // parameter and passing along the remaining arguments. 5417 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 5418 const FunctionProtoType *Proto = Method->getType()->getAs<FunctionProtoType>(); 5419 5420 unsigned NumArgsInProto = Proto->getNumArgs(); 5421 unsigned NumArgsToCheck = NumArgs; 5422 5423 // Build the full argument list for the method call (the 5424 // implicit object parameter is placed at the beginning of the 5425 // list). 5426 Expr **MethodArgs; 5427 if (NumArgs < NumArgsInProto) { 5428 NumArgsToCheck = NumArgsInProto; 5429 MethodArgs = new Expr*[NumArgsInProto + 1]; 5430 } else { 5431 MethodArgs = new Expr*[NumArgs + 1]; 5432 } 5433 MethodArgs[0] = Object; 5434 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 5435 MethodArgs[ArgIdx + 1] = Args[ArgIdx]; 5436 5437 Expr *NewFn = new (Context) DeclRefExpr(Method, Method->getType(), 5438 SourceLocation()); 5439 UsualUnaryConversions(NewFn); 5440 5441 // Once we've built TheCall, all of the expressions are properly 5442 // owned. 5443 QualType ResultTy = Method->getResultType().getNonReferenceType(); 5444 ExprOwningPtr<CXXOperatorCallExpr> 5445 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Call, NewFn, 5446 MethodArgs, NumArgs + 1, 5447 ResultTy, RParenLoc)); 5448 delete [] MethodArgs; 5449 5450 if (CheckCallReturnType(Method->getResultType(), LParenLoc, TheCall.get(), 5451 Method)) 5452 return true; 5453 5454 // We may have default arguments. If so, we need to allocate more 5455 // slots in the call for them. 5456 if (NumArgs < NumArgsInProto) 5457 TheCall->setNumArgs(Context, NumArgsInProto + 1); 5458 else if (NumArgs > NumArgsInProto) 5459 NumArgsToCheck = NumArgsInProto; 5460 5461 bool IsError = false; 5462 5463 // Initialize the implicit object parameter. 5464 IsError |= PerformObjectArgumentInitialization(Object, Method); 5465 TheCall->setArg(0, Object); 5466 5467 5468 // Check the argument types. 5469 for (unsigned i = 0; i != NumArgsToCheck; i++) { 5470 Expr *Arg; 5471 if (i < NumArgs) { 5472 Arg = Args[i]; 5473 5474 // Pass the argument. 5475 QualType ProtoArgType = Proto->getArgType(i); 5476 IsError |= PerformCopyInitialization(Arg, ProtoArgType, "passing"); 5477 } else { 5478 OwningExprResult DefArg 5479 = BuildCXXDefaultArgExpr(LParenLoc, Method, Method->getParamDecl(i)); 5480 if (DefArg.isInvalid()) { 5481 IsError = true; 5482 break; 5483 } 5484 5485 Arg = DefArg.takeAs<Expr>(); 5486 } 5487 5488 TheCall->setArg(i + 1, Arg); 5489 } 5490 5491 // If this is a variadic call, handle args passed through "...". 5492 if (Proto->isVariadic()) { 5493 // Promote the arguments (C99 6.5.2.2p7). 5494 for (unsigned i = NumArgsInProto; i != NumArgs; i++) { 5495 Expr *Arg = Args[i]; 5496 IsError |= DefaultVariadicArgumentPromotion(Arg, VariadicMethod); 5497 TheCall->setArg(i + 1, Arg); 5498 } 5499 } 5500 5501 if (IsError) return true; 5502 5503 if (CheckFunctionCall(Method, TheCall.get())) 5504 return true; 5505 5506 return MaybeBindToTemporary(TheCall.release()).release(); 5507} 5508 5509/// BuildOverloadedArrowExpr - Build a call to an overloaded @c operator-> 5510/// (if one exists), where @c Base is an expression of class type and 5511/// @c Member is the name of the member we're trying to find. 5512Sema::OwningExprResult 5513Sema::BuildOverloadedArrowExpr(Scope *S, ExprArg BaseIn, SourceLocation OpLoc) { 5514 Expr *Base = static_cast<Expr *>(BaseIn.get()); 5515 assert(Base->getType()->isRecordType() && "left-hand side must have class type"); 5516 5517 // C++ [over.ref]p1: 5518 // 5519 // [...] An expression x->m is interpreted as (x.operator->())->m 5520 // for a class object x of type T if T::operator->() exists and if 5521 // the operator is selected as the best match function by the 5522 // overload resolution mechanism (13.3). 5523 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Arrow); 5524 OverloadCandidateSet CandidateSet; 5525 const RecordType *BaseRecord = Base->getType()->getAs<RecordType>(); 5526 5527 if (RequireCompleteType(Base->getLocStart(), Base->getType(), 5528 PDiag(diag::err_typecheck_incomplete_tag) 5529 << Base->getSourceRange())) 5530 return ExprError(); 5531 5532 LookupResult R(*this, OpName, OpLoc, LookupOrdinaryName); 5533 LookupQualifiedName(R, BaseRecord->getDecl()); 5534 R.suppressDiagnostics(); 5535 5536 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 5537 Oper != OperEnd; ++Oper) 5538 AddMethodCandidate(cast<CXXMethodDecl>(*Oper), Base, 0, 0, CandidateSet, 5539 /*SuppressUserConversions=*/false); 5540 5541 // Perform overload resolution. 5542 OverloadCandidateSet::iterator Best; 5543 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 5544 case OR_Success: 5545 // Overload resolution succeeded; we'll build the call below. 5546 break; 5547 5548 case OR_No_Viable_Function: 5549 if (CandidateSet.empty()) 5550 Diag(OpLoc, diag::err_typecheck_member_reference_arrow) 5551 << Base->getType() << Base->getSourceRange(); 5552 else 5553 Diag(OpLoc, diag::err_ovl_no_viable_oper) 5554 << "operator->" << Base->getSourceRange(); 5555 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 5556 return ExprError(); 5557 5558 case OR_Ambiguous: 5559 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 5560 << "->" << Base->getSourceRange(); 5561 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 5562 return ExprError(); 5563 5564 case OR_Deleted: 5565 Diag(OpLoc, diag::err_ovl_deleted_oper) 5566 << Best->Function->isDeleted() 5567 << "->" << Base->getSourceRange(); 5568 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 5569 return ExprError(); 5570 } 5571 5572 // Convert the object parameter. 5573 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 5574 if (PerformObjectArgumentInitialization(Base, Method)) 5575 return ExprError(); 5576 5577 // No concerns about early exits now. 5578 BaseIn.release(); 5579 5580 // Build the operator call. 5581 Expr *FnExpr = new (Context) DeclRefExpr(Method, Method->getType(), 5582 SourceLocation()); 5583 UsualUnaryConversions(FnExpr); 5584 5585 QualType ResultTy = Method->getResultType().getNonReferenceType(); 5586 ExprOwningPtr<CXXOperatorCallExpr> 5587 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Arrow, FnExpr, 5588 &Base, 1, ResultTy, OpLoc)); 5589 5590 if (CheckCallReturnType(Method->getResultType(), OpLoc, TheCall.get(), 5591 Method)) 5592 return ExprError(); 5593 return move(TheCall); 5594} 5595 5596/// FixOverloadedFunctionReference - E is an expression that refers to 5597/// a C++ overloaded function (possibly with some parentheses and 5598/// perhaps a '&' around it). We have resolved the overloaded function 5599/// to the function declaration Fn, so patch up the expression E to 5600/// refer (possibly indirectly) to Fn. Returns the new expr. 5601Expr *Sema::FixOverloadedFunctionReference(Expr *E, FunctionDecl *Fn) { 5602 if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) { 5603 Expr *NewExpr = FixOverloadedFunctionReference(PE->getSubExpr(), Fn); 5604 PE->setSubExpr(NewExpr); 5605 PE->setType(NewExpr->getType()); 5606 } else if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) { 5607 Expr *NewExpr = FixOverloadedFunctionReference(ICE->getSubExpr(), Fn); 5608 assert(Context.hasSameType(ICE->getSubExpr()->getType(), 5609 NewExpr->getType()) && 5610 "Implicit cast type cannot be determined from overload"); 5611 ICE->setSubExpr(NewExpr); 5612 } else if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(E)) { 5613 assert(UnOp->getOpcode() == UnaryOperator::AddrOf && 5614 "Can only take the address of an overloaded function"); 5615 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 5616 if (Method->isStatic()) { 5617 // Do nothing: static member functions aren't any different 5618 // from non-member functions. 5619 } else if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(UnOp->getSubExpr())) { 5620 if (DRE->getQualifier()) { 5621 // We have taken the address of a pointer to member 5622 // function. Perform the computation here so that we get the 5623 // appropriate pointer to member type. 5624 DRE->setDecl(Fn); 5625 DRE->setType(Fn->getType()); 5626 QualType ClassType 5627 = Context.getTypeDeclType(cast<RecordDecl>(Method->getDeclContext())); 5628 E->setType(Context.getMemberPointerType(Fn->getType(), 5629 ClassType.getTypePtr())); 5630 return E; 5631 } 5632 } 5633 // FIXME: TemplateIdRefExpr referring to a member function template 5634 // specialization! 5635 } 5636 Expr *NewExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(), Fn); 5637 UnOp->setSubExpr(NewExpr); 5638 UnOp->setType(Context.getPointerType(NewExpr->getType())); 5639 5640 return UnOp; 5641 } else if (DeclRefExpr *DR = dyn_cast<DeclRefExpr>(E)) { 5642 assert((isa<OverloadedFunctionDecl>(DR->getDecl()) || 5643 isa<FunctionTemplateDecl>(DR->getDecl()) || 5644 isa<FunctionDecl>(DR->getDecl())) && 5645 "Expected function or function template"); 5646 DR->setDecl(Fn); 5647 E->setType(Fn->getType()); 5648 } else if (MemberExpr *MemExpr = dyn_cast<MemberExpr>(E)) { 5649 MemExpr->setMemberDecl(Fn); 5650 E->setType(Fn->getType()); 5651 } else if (TemplateIdRefExpr *TID = dyn_cast<TemplateIdRefExpr>(E)) { 5652 E = DeclRefExpr::Create(Context, 5653 TID->getQualifier(), TID->getQualifierRange(), 5654 Fn, TID->getTemplateNameLoc(), 5655 true, 5656 TID->getLAngleLoc(), 5657 TID->getTemplateArgs(), 5658 TID->getNumTemplateArgs(), 5659 TID->getRAngleLoc(), 5660 Fn->getType(), 5661 /*FIXME?*/false, /*FIXME?*/false); 5662 5663 // FIXME: Don't destroy TID here, since we need its template arguments 5664 // to survive. 5665 // TID->Destroy(Context); 5666 } else if (isa<UnresolvedFunctionNameExpr>(E)) { 5667 return DeclRefExpr::Create(Context, 5668 /*Qualifier=*/0, 5669 /*QualifierRange=*/SourceRange(), 5670 Fn, E->getLocStart(), 5671 Fn->getType(), false, false); 5672 } else { 5673 assert(false && "Invalid reference to overloaded function"); 5674 } 5675 5676 return E; 5677} 5678 5679} // end namespace clang 5680