SemaOverload.cpp revision 739d8283149d999f598a7514c6ec2b42598f51d3
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 "SemaInherit.h" 16#include "clang/Basic/Diagnostic.h" 17#include "clang/Lex/Preprocessor.h" 18#include "clang/AST/ASTContext.h" 19#include "clang/AST/Expr.h" 20#include "clang/AST/ExprCXX.h" 21#include "clang/AST/TypeOrdering.h" 22#include "clang/Basic/PartialDiagnostic.h" 23#include "llvm/ADT/SmallPtrSet.h" 24#include "llvm/ADT/STLExtras.h" 25#include "llvm/Support/Compiler.h" 26#include <algorithm> 27#include <cstdio> 28 29namespace clang { 30 31/// GetConversionCategory - Retrieve the implicit conversion 32/// category corresponding to the given implicit conversion kind. 33ImplicitConversionCategory 34GetConversionCategory(ImplicitConversionKind Kind) { 35 static const ImplicitConversionCategory 36 Category[(int)ICK_Num_Conversion_Kinds] = { 37 ICC_Identity, 38 ICC_Lvalue_Transformation, 39 ICC_Lvalue_Transformation, 40 ICC_Lvalue_Transformation, 41 ICC_Qualification_Adjustment, 42 ICC_Promotion, 43 ICC_Promotion, 44 ICC_Promotion, 45 ICC_Conversion, 46 ICC_Conversion, 47 ICC_Conversion, 48 ICC_Conversion, 49 ICC_Conversion, 50 ICC_Conversion, 51 ICC_Conversion, 52 ICC_Conversion, 53 ICC_Conversion, 54 ICC_Conversion 55 }; 56 return Category[(int)Kind]; 57} 58 59/// GetConversionRank - Retrieve the implicit conversion rank 60/// corresponding to the given implicit conversion kind. 61ImplicitConversionRank GetConversionRank(ImplicitConversionKind Kind) { 62 static const ImplicitConversionRank 63 Rank[(int)ICK_Num_Conversion_Kinds] = { 64 ICR_Exact_Match, 65 ICR_Exact_Match, 66 ICR_Exact_Match, 67 ICR_Exact_Match, 68 ICR_Exact_Match, 69 ICR_Promotion, 70 ICR_Promotion, 71 ICR_Promotion, 72 ICR_Conversion, 73 ICR_Conversion, 74 ICR_Conversion, 75 ICR_Conversion, 76 ICR_Conversion, 77 ICR_Conversion, 78 ICR_Conversion, 79 ICR_Conversion, 80 ICR_Conversion, 81 ICR_Conversion 82 }; 83 return Rank[(int)Kind]; 84} 85 86/// GetImplicitConversionName - Return the name of this kind of 87/// implicit conversion. 88const char* GetImplicitConversionName(ImplicitConversionKind Kind) { 89 static const char* Name[(int)ICK_Num_Conversion_Kinds] = { 90 "No conversion", 91 "Lvalue-to-rvalue", 92 "Array-to-pointer", 93 "Function-to-pointer", 94 "Qualification", 95 "Integral promotion", 96 "Floating point promotion", 97 "Complex promotion", 98 "Integral conversion", 99 "Floating conversion", 100 "Complex conversion", 101 "Floating-integral conversion", 102 "Complex-real conversion", 103 "Pointer conversion", 104 "Pointer-to-member conversion", 105 "Boolean conversion", 106 "Compatible-types conversion", 107 "Derived-to-base conversion" 108 }; 109 return Name[Kind]; 110} 111 112/// StandardConversionSequence - Set the standard conversion 113/// sequence to the identity conversion. 114void StandardConversionSequence::setAsIdentityConversion() { 115 First = ICK_Identity; 116 Second = ICK_Identity; 117 Third = ICK_Identity; 118 Deprecated = false; 119 ReferenceBinding = false; 120 DirectBinding = false; 121 RRefBinding = false; 122 CopyConstructor = 0; 123} 124 125/// getRank - Retrieve the rank of this standard conversion sequence 126/// (C++ 13.3.3.1.1p3). The rank is the largest rank of each of the 127/// implicit conversions. 128ImplicitConversionRank StandardConversionSequence::getRank() const { 129 ImplicitConversionRank Rank = ICR_Exact_Match; 130 if (GetConversionRank(First) > Rank) 131 Rank = GetConversionRank(First); 132 if (GetConversionRank(Second) > Rank) 133 Rank = GetConversionRank(Second); 134 if (GetConversionRank(Third) > Rank) 135 Rank = GetConversionRank(Third); 136 return Rank; 137} 138 139/// isPointerConversionToBool - Determines whether this conversion is 140/// a conversion of a pointer or pointer-to-member to bool. This is 141/// used as part of the ranking of standard conversion sequences 142/// (C++ 13.3.3.2p4). 143bool StandardConversionSequence::isPointerConversionToBool() const { 144 QualType FromType = QualType::getFromOpaquePtr(FromTypePtr); 145 QualType ToType = QualType::getFromOpaquePtr(ToTypePtr); 146 147 // Note that FromType has not necessarily been transformed by the 148 // array-to-pointer or function-to-pointer implicit conversions, so 149 // check for their presence as well as checking whether FromType is 150 // a pointer. 151 if (ToType->isBooleanType() && 152 (FromType->isPointerType() || FromType->isBlockPointerType() || 153 First == ICK_Array_To_Pointer || First == ICK_Function_To_Pointer)) 154 return true; 155 156 return false; 157} 158 159/// isPointerConversionToVoidPointer - Determines whether this 160/// conversion is a conversion of a pointer to a void pointer. This is 161/// used as part of the ranking of standard conversion sequences (C++ 162/// 13.3.3.2p4). 163bool 164StandardConversionSequence:: 165isPointerConversionToVoidPointer(ASTContext& Context) const { 166 QualType FromType = QualType::getFromOpaquePtr(FromTypePtr); 167 QualType ToType = QualType::getFromOpaquePtr(ToTypePtr); 168 169 // Note that FromType has not necessarily been transformed by the 170 // array-to-pointer implicit conversion, so check for its presence 171 // and redo the conversion to get a pointer. 172 if (First == ICK_Array_To_Pointer) 173 FromType = Context.getArrayDecayedType(FromType); 174 175 if (Second == ICK_Pointer_Conversion) 176 if (const PointerType* ToPtrType = ToType->getAs<PointerType>()) 177 return ToPtrType->getPointeeType()->isVoidType(); 178 179 return false; 180} 181 182/// DebugPrint - Print this standard conversion sequence to standard 183/// error. Useful for debugging overloading issues. 184void StandardConversionSequence::DebugPrint() const { 185 bool PrintedSomething = false; 186 if (First != ICK_Identity) { 187 fprintf(stderr, "%s", GetImplicitConversionName(First)); 188 PrintedSomething = true; 189 } 190 191 if (Second != ICK_Identity) { 192 if (PrintedSomething) { 193 fprintf(stderr, " -> "); 194 } 195 fprintf(stderr, "%s", GetImplicitConversionName(Second)); 196 197 if (CopyConstructor) { 198 fprintf(stderr, " (by copy constructor)"); 199 } else if (DirectBinding) { 200 fprintf(stderr, " (direct reference binding)"); 201 } else if (ReferenceBinding) { 202 fprintf(stderr, " (reference binding)"); 203 } 204 PrintedSomething = true; 205 } 206 207 if (Third != ICK_Identity) { 208 if (PrintedSomething) { 209 fprintf(stderr, " -> "); 210 } 211 fprintf(stderr, "%s", GetImplicitConversionName(Third)); 212 PrintedSomething = true; 213 } 214 215 if (!PrintedSomething) { 216 fprintf(stderr, "No conversions required"); 217 } 218} 219 220/// DebugPrint - Print this user-defined conversion sequence to standard 221/// error. Useful for debugging overloading issues. 222void UserDefinedConversionSequence::DebugPrint() const { 223 if (Before.First || Before.Second || Before.Third) { 224 Before.DebugPrint(); 225 fprintf(stderr, " -> "); 226 } 227 fprintf(stderr, "'%s'", ConversionFunction->getNameAsString().c_str()); 228 if (After.First || After.Second || After.Third) { 229 fprintf(stderr, " -> "); 230 After.DebugPrint(); 231 } 232} 233 234/// DebugPrint - Print this implicit conversion sequence to standard 235/// error. Useful for debugging overloading issues. 236void ImplicitConversionSequence::DebugPrint() const { 237 switch (ConversionKind) { 238 case StandardConversion: 239 fprintf(stderr, "Standard conversion: "); 240 Standard.DebugPrint(); 241 break; 242 case UserDefinedConversion: 243 fprintf(stderr, "User-defined conversion: "); 244 UserDefined.DebugPrint(); 245 break; 246 case EllipsisConversion: 247 fprintf(stderr, "Ellipsis conversion"); 248 break; 249 case BadConversion: 250 fprintf(stderr, "Bad conversion"); 251 break; 252 } 253 254 fprintf(stderr, "\n"); 255} 256 257// IsOverload - Determine whether the given New declaration is an 258// overload of the Old declaration. This routine returns false if New 259// and Old cannot be overloaded, e.g., if they are functions with the 260// same signature (C++ 1.3.10) or if the Old declaration isn't a 261// function (or overload set). When it does return false and Old is an 262// OverloadedFunctionDecl, MatchedDecl will be set to point to the 263// FunctionDecl that New cannot be overloaded with. 264// 265// Example: Given the following input: 266// 267// void f(int, float); // #1 268// void f(int, int); // #2 269// int f(int, int); // #3 270// 271// When we process #1, there is no previous declaration of "f", 272// so IsOverload will not be used. 273// 274// When we process #2, Old is a FunctionDecl for #1. By comparing the 275// parameter types, we see that #1 and #2 are overloaded (since they 276// have different signatures), so this routine returns false; 277// MatchedDecl is unchanged. 278// 279// When we process #3, Old is an OverloadedFunctionDecl containing #1 280// and #2. We compare the signatures of #3 to #1 (they're overloaded, 281// so we do nothing) and then #3 to #2. Since the signatures of #3 and 282// #2 are identical (return types of functions are not part of the 283// signature), IsOverload returns false and MatchedDecl will be set to 284// point to the FunctionDecl for #2. 285bool 286Sema::IsOverload(FunctionDecl *New, Decl* OldD, 287 OverloadedFunctionDecl::function_iterator& MatchedDecl) { 288 if (OverloadedFunctionDecl* Ovl = dyn_cast<OverloadedFunctionDecl>(OldD)) { 289 // Is this new function an overload of every function in the 290 // overload set? 291 OverloadedFunctionDecl::function_iterator Func = Ovl->function_begin(), 292 FuncEnd = Ovl->function_end(); 293 for (; Func != FuncEnd; ++Func) { 294 if (!IsOverload(New, *Func, MatchedDecl)) { 295 MatchedDecl = Func; 296 return false; 297 } 298 } 299 300 // This function overloads every function in the overload set. 301 return true; 302 } else if (FunctionTemplateDecl *Old = dyn_cast<FunctionTemplateDecl>(OldD)) 303 return IsOverload(New, Old->getTemplatedDecl(), MatchedDecl); 304 else if (FunctionDecl* Old = dyn_cast<FunctionDecl>(OldD)) { 305 FunctionTemplateDecl *OldTemplate = Old->getDescribedFunctionTemplate(); 306 FunctionTemplateDecl *NewTemplate = New->getDescribedFunctionTemplate(); 307 308 // C++ [temp.fct]p2: 309 // A function template can be overloaded with other function templates 310 // and with normal (non-template) functions. 311 if ((OldTemplate == 0) != (NewTemplate == 0)) 312 return true; 313 314 // Is the function New an overload of the function Old? 315 QualType OldQType = Context.getCanonicalType(Old->getType()); 316 QualType NewQType = Context.getCanonicalType(New->getType()); 317 318 // Compare the signatures (C++ 1.3.10) of the two functions to 319 // determine whether they are overloads. If we find any mismatch 320 // in the signature, they are overloads. 321 322 // If either of these functions is a K&R-style function (no 323 // prototype), then we consider them to have matching signatures. 324 if (isa<FunctionNoProtoType>(OldQType.getTypePtr()) || 325 isa<FunctionNoProtoType>(NewQType.getTypePtr())) 326 return false; 327 328 FunctionProtoType* OldType = cast<FunctionProtoType>(OldQType); 329 FunctionProtoType* NewType = cast<FunctionProtoType>(NewQType); 330 331 // The signature of a function includes the types of its 332 // parameters (C++ 1.3.10), which includes the presence or absence 333 // of the ellipsis; see C++ DR 357). 334 if (OldQType != NewQType && 335 (OldType->getNumArgs() != NewType->getNumArgs() || 336 OldType->isVariadic() != NewType->isVariadic() || 337 !std::equal(OldType->arg_type_begin(), OldType->arg_type_end(), 338 NewType->arg_type_begin()))) 339 return true; 340 341 // C++ [temp.over.link]p4: 342 // The signature of a function template consists of its function 343 // signature, its return type and its template parameter list. The names 344 // of the template parameters are significant only for establishing the 345 // relationship between the template parameters and the rest of the 346 // signature. 347 // 348 // We check the return type and template parameter lists for function 349 // templates first; the remaining checks follow. 350 if (NewTemplate && 351 (!TemplateParameterListsAreEqual(NewTemplate->getTemplateParameters(), 352 OldTemplate->getTemplateParameters(), 353 false, false, SourceLocation()) || 354 OldType->getResultType() != NewType->getResultType())) 355 return true; 356 357 // If the function is a class member, its signature includes the 358 // cv-qualifiers (if any) on the function itself. 359 // 360 // As part of this, also check whether one of the member functions 361 // is static, in which case they are not overloads (C++ 362 // 13.1p2). While not part of the definition of the signature, 363 // this check is important to determine whether these functions 364 // can be overloaded. 365 CXXMethodDecl* OldMethod = dyn_cast<CXXMethodDecl>(Old); 366 CXXMethodDecl* NewMethod = dyn_cast<CXXMethodDecl>(New); 367 if (OldMethod && NewMethod && 368 !OldMethod->isStatic() && !NewMethod->isStatic() && 369 OldMethod->getTypeQualifiers() != NewMethod->getTypeQualifiers()) 370 return true; 371 372 // The signatures match; this is not an overload. 373 return false; 374 } else { 375 // (C++ 13p1): 376 // Only function declarations can be overloaded; object and type 377 // declarations cannot be overloaded. 378 return false; 379 } 380} 381 382/// TryImplicitConversion - Attempt to perform an implicit conversion 383/// from the given expression (Expr) to the given type (ToType). This 384/// function returns an implicit conversion sequence that can be used 385/// to perform the initialization. Given 386/// 387/// void f(float f); 388/// void g(int i) { f(i); } 389/// 390/// this routine would produce an implicit conversion sequence to 391/// describe the initialization of f from i, which will be a standard 392/// conversion sequence containing an lvalue-to-rvalue conversion (C++ 393/// 4.1) followed by a floating-integral conversion (C++ 4.9). 394// 395/// Note that this routine only determines how the conversion can be 396/// performed; it does not actually perform the conversion. As such, 397/// it will not produce any diagnostics if no conversion is available, 398/// but will instead return an implicit conversion sequence of kind 399/// "BadConversion". 400/// 401/// If @p SuppressUserConversions, then user-defined conversions are 402/// not permitted. 403/// If @p AllowExplicit, then explicit user-defined conversions are 404/// permitted. 405/// If @p ForceRValue, then overloading is performed as if From was an rvalue, 406/// no matter its actual lvalueness. 407ImplicitConversionSequence 408Sema::TryImplicitConversion(Expr* From, QualType ToType, 409 bool SuppressUserConversions, 410 bool AllowExplicit, bool ForceRValue, 411 bool InOverloadResolution) { 412 ImplicitConversionSequence ICS; 413 OverloadCandidateSet Conversions; 414 OverloadingResult UserDefResult = OR_Success; 415 if (IsStandardConversion(From, ToType, InOverloadResolution, ICS.Standard)) 416 ICS.ConversionKind = ImplicitConversionSequence::StandardConversion; 417 else if (getLangOptions().CPlusPlus && 418 (UserDefResult = IsUserDefinedConversion(From, ToType, 419 ICS.UserDefined, 420 Conversions, 421 !SuppressUserConversions, AllowExplicit, 422 ForceRValue)) == OR_Success) { 423 ICS.ConversionKind = ImplicitConversionSequence::UserDefinedConversion; 424 // C++ [over.ics.user]p4: 425 // A conversion of an expression of class type to the same class 426 // type is given Exact Match rank, and a conversion of an 427 // expression of class type to a base class of that type is 428 // given Conversion rank, in spite of the fact that a copy 429 // constructor (i.e., a user-defined conversion function) is 430 // called for those cases. 431 if (CXXConstructorDecl *Constructor 432 = dyn_cast<CXXConstructorDecl>(ICS.UserDefined.ConversionFunction)) { 433 QualType FromCanon 434 = Context.getCanonicalType(From->getType().getUnqualifiedType()); 435 QualType ToCanon = Context.getCanonicalType(ToType).getUnqualifiedType(); 436 if (FromCanon == ToCanon || IsDerivedFrom(FromCanon, ToCanon)) { 437 // Turn this into a "standard" conversion sequence, so that it 438 // gets ranked with standard conversion sequences. 439 ICS.ConversionKind = ImplicitConversionSequence::StandardConversion; 440 ICS.Standard.setAsIdentityConversion(); 441 ICS.Standard.FromTypePtr = From->getType().getAsOpaquePtr(); 442 ICS.Standard.ToTypePtr = ToType.getAsOpaquePtr(); 443 ICS.Standard.CopyConstructor = Constructor; 444 if (ToCanon != FromCanon) 445 ICS.Standard.Second = ICK_Derived_To_Base; 446 } 447 } 448 449 // C++ [over.best.ics]p4: 450 // However, when considering the argument of a user-defined 451 // conversion function that is a candidate by 13.3.1.3 when 452 // invoked for the copying of the temporary in the second step 453 // of a class copy-initialization, or by 13.3.1.4, 13.3.1.5, or 454 // 13.3.1.6 in all cases, only standard conversion sequences and 455 // ellipsis conversion sequences are allowed. 456 if (SuppressUserConversions && 457 ICS.ConversionKind == ImplicitConversionSequence::UserDefinedConversion) 458 ICS.ConversionKind = ImplicitConversionSequence::BadConversion; 459 } else { 460 ICS.ConversionKind = ImplicitConversionSequence::BadConversion; 461 if (UserDefResult == OR_Ambiguous) { 462 for (OverloadCandidateSet::iterator Cand = Conversions.begin(); 463 Cand != Conversions.end(); ++Cand) 464 ICS.ConversionFunctionSet.push_back(Cand->Function); 465 } 466 } 467 468 return ICS; 469} 470 471/// IsStandardConversion - Determines whether there is a standard 472/// conversion sequence (C++ [conv], C++ [over.ics.scs]) from the 473/// expression From to the type ToType. Standard conversion sequences 474/// only consider non-class types; for conversions that involve class 475/// types, use TryImplicitConversion. If a conversion exists, SCS will 476/// contain the standard conversion sequence required to perform this 477/// conversion and this routine will return true. Otherwise, this 478/// routine will return false and the value of SCS is unspecified. 479bool 480Sema::IsStandardConversion(Expr* From, QualType ToType, 481 bool InOverloadResolution, 482 StandardConversionSequence &SCS) { 483 QualType FromType = From->getType(); 484 485 // Standard conversions (C++ [conv]) 486 SCS.setAsIdentityConversion(); 487 SCS.Deprecated = false; 488 SCS.IncompatibleObjC = false; 489 SCS.FromTypePtr = FromType.getAsOpaquePtr(); 490 SCS.CopyConstructor = 0; 491 492 // There are no standard conversions for class types in C++, so 493 // abort early. When overloading in C, however, we do permit 494 if (FromType->isRecordType() || ToType->isRecordType()) { 495 if (getLangOptions().CPlusPlus) 496 return false; 497 498 // When we're overloading in C, we allow, as standard conversions, 499 } 500 501 // The first conversion can be an lvalue-to-rvalue conversion, 502 // array-to-pointer conversion, or function-to-pointer conversion 503 // (C++ 4p1). 504 505 // Lvalue-to-rvalue conversion (C++ 4.1): 506 // An lvalue (3.10) of a non-function, non-array type T can be 507 // converted to an rvalue. 508 Expr::isLvalueResult argIsLvalue = From->isLvalue(Context); 509 if (argIsLvalue == Expr::LV_Valid && 510 !FromType->isFunctionType() && !FromType->isArrayType() && 511 Context.getCanonicalType(FromType) != Context.OverloadTy) { 512 SCS.First = ICK_Lvalue_To_Rvalue; 513 514 // If T is a non-class type, the type of the rvalue is the 515 // cv-unqualified version of T. Otherwise, the type of the rvalue 516 // is T (C++ 4.1p1). C++ can't get here with class types; in C, we 517 // just strip the qualifiers because they don't matter. 518 519 // FIXME: Doesn't see through to qualifiers behind a typedef! 520 FromType = FromType.getUnqualifiedType(); 521 } else if (FromType->isArrayType()) { 522 // Array-to-pointer conversion (C++ 4.2) 523 SCS.First = ICK_Array_To_Pointer; 524 525 // An lvalue or rvalue of type "array of N T" or "array of unknown 526 // bound of T" can be converted to an rvalue of type "pointer to 527 // T" (C++ 4.2p1). 528 FromType = Context.getArrayDecayedType(FromType); 529 530 if (IsStringLiteralToNonConstPointerConversion(From, ToType)) { 531 // This conversion is deprecated. (C++ D.4). 532 SCS.Deprecated = true; 533 534 // For the purpose of ranking in overload resolution 535 // (13.3.3.1.1), this conversion is considered an 536 // array-to-pointer conversion followed by a qualification 537 // conversion (4.4). (C++ 4.2p2) 538 SCS.Second = ICK_Identity; 539 SCS.Third = ICK_Qualification; 540 SCS.ToTypePtr = ToType.getAsOpaquePtr(); 541 return true; 542 } 543 } else if (FromType->isFunctionType() && argIsLvalue == Expr::LV_Valid) { 544 // Function-to-pointer conversion (C++ 4.3). 545 SCS.First = ICK_Function_To_Pointer; 546 547 // An lvalue of function type T can be converted to an rvalue of 548 // type "pointer to T." The result is a pointer to the 549 // function. (C++ 4.3p1). 550 FromType = Context.getPointerType(FromType); 551 } else if (FunctionDecl *Fn 552 = ResolveAddressOfOverloadedFunction(From, ToType, false)) { 553 // Address of overloaded function (C++ [over.over]). 554 SCS.First = ICK_Function_To_Pointer; 555 556 // We were able to resolve the address of the overloaded function, 557 // so we can convert to the type of that function. 558 FromType = Fn->getType(); 559 if (ToType->isLValueReferenceType()) 560 FromType = Context.getLValueReferenceType(FromType); 561 else if (ToType->isRValueReferenceType()) 562 FromType = Context.getRValueReferenceType(FromType); 563 else if (ToType->isMemberPointerType()) { 564 // Resolve address only succeeds if both sides are member pointers, 565 // but it doesn't have to be the same class. See DR 247. 566 // Note that this means that the type of &Derived::fn can be 567 // Ret (Base::*)(Args) if the fn overload actually found is from the 568 // base class, even if it was brought into the derived class via a 569 // using declaration. The standard isn't clear on this issue at all. 570 CXXMethodDecl *M = cast<CXXMethodDecl>(Fn); 571 FromType = Context.getMemberPointerType(FromType, 572 Context.getTypeDeclType(M->getParent()).getTypePtr()); 573 } else 574 FromType = Context.getPointerType(FromType); 575 } else { 576 // We don't require any conversions for the first step. 577 SCS.First = ICK_Identity; 578 } 579 580 // The second conversion can be an integral promotion, floating 581 // point promotion, integral conversion, floating point conversion, 582 // floating-integral conversion, pointer conversion, 583 // pointer-to-member conversion, or boolean conversion (C++ 4p1). 584 // For overloading in C, this can also be a "compatible-type" 585 // conversion. 586 bool IncompatibleObjC = false; 587 if (Context.hasSameUnqualifiedType(FromType, ToType)) { 588 // The unqualified versions of the types are the same: there's no 589 // conversion to do. 590 SCS.Second = ICK_Identity; 591 } else if (IsIntegralPromotion(From, FromType, ToType)) { 592 // Integral promotion (C++ 4.5). 593 SCS.Second = ICK_Integral_Promotion; 594 FromType = ToType.getUnqualifiedType(); 595 } else if (IsFloatingPointPromotion(FromType, ToType)) { 596 // Floating point promotion (C++ 4.6). 597 SCS.Second = ICK_Floating_Promotion; 598 FromType = ToType.getUnqualifiedType(); 599 } else if (IsComplexPromotion(FromType, ToType)) { 600 // Complex promotion (Clang extension) 601 SCS.Second = ICK_Complex_Promotion; 602 FromType = ToType.getUnqualifiedType(); 603 } else if ((FromType->isIntegralType() || FromType->isEnumeralType()) && 604 (ToType->isIntegralType() && !ToType->isEnumeralType())) { 605 // Integral conversions (C++ 4.7). 606 // FIXME: isIntegralType shouldn't be true for enums in C++. 607 SCS.Second = ICK_Integral_Conversion; 608 FromType = ToType.getUnqualifiedType(); 609 } else if (FromType->isFloatingType() && ToType->isFloatingType()) { 610 // Floating point conversions (C++ 4.8). 611 SCS.Second = ICK_Floating_Conversion; 612 FromType = ToType.getUnqualifiedType(); 613 } else if (FromType->isComplexType() && ToType->isComplexType()) { 614 // Complex conversions (C99 6.3.1.6) 615 SCS.Second = ICK_Complex_Conversion; 616 FromType = ToType.getUnqualifiedType(); 617 } else if ((FromType->isFloatingType() && 618 ToType->isIntegralType() && (!ToType->isBooleanType() && 619 !ToType->isEnumeralType())) || 620 ((FromType->isIntegralType() || FromType->isEnumeralType()) && 621 ToType->isFloatingType())) { 622 // Floating-integral conversions (C++ 4.9). 623 // FIXME: isIntegralType shouldn't be true for enums in C++. 624 SCS.Second = ICK_Floating_Integral; 625 FromType = ToType.getUnqualifiedType(); 626 } else if ((FromType->isComplexType() && ToType->isArithmeticType()) || 627 (ToType->isComplexType() && FromType->isArithmeticType())) { 628 // Complex-real conversions (C99 6.3.1.7) 629 SCS.Second = ICK_Complex_Real; 630 FromType = ToType.getUnqualifiedType(); 631 } else if (IsPointerConversion(From, FromType, ToType, InOverloadResolution, 632 FromType, IncompatibleObjC)) { 633 // Pointer conversions (C++ 4.10). 634 SCS.Second = ICK_Pointer_Conversion; 635 SCS.IncompatibleObjC = IncompatibleObjC; 636 } else if (IsMemberPointerConversion(From, FromType, ToType, FromType)) { 637 // Pointer to member conversions (4.11). 638 SCS.Second = ICK_Pointer_Member; 639 } else if (ToType->isBooleanType() && 640 (FromType->isArithmeticType() || 641 FromType->isEnumeralType() || 642 FromType->isPointerType() || 643 FromType->isBlockPointerType() || 644 FromType->isMemberPointerType() || 645 FromType->isNullPtrType())) { 646 // Boolean conversions (C++ 4.12). 647 SCS.Second = ICK_Boolean_Conversion; 648 FromType = Context.BoolTy; 649 } else if (!getLangOptions().CPlusPlus && 650 Context.typesAreCompatible(ToType, FromType)) { 651 // Compatible conversions (Clang extension for C function overloading) 652 SCS.Second = ICK_Compatible_Conversion; 653 } else { 654 // No second conversion required. 655 SCS.Second = ICK_Identity; 656 } 657 658 QualType CanonFrom; 659 QualType CanonTo; 660 // The third conversion can be a qualification conversion (C++ 4p1). 661 if (IsQualificationConversion(FromType, ToType)) { 662 SCS.Third = ICK_Qualification; 663 FromType = ToType; 664 CanonFrom = Context.getCanonicalType(FromType); 665 CanonTo = Context.getCanonicalType(ToType); 666 } else { 667 // No conversion required 668 SCS.Third = ICK_Identity; 669 670 // C++ [over.best.ics]p6: 671 // [...] Any difference in top-level cv-qualification is 672 // subsumed by the initialization itself and does not constitute 673 // a conversion. [...] 674 CanonFrom = Context.getCanonicalType(FromType); 675 CanonTo = Context.getCanonicalType(ToType); 676 if (CanonFrom.getUnqualifiedType() == CanonTo.getUnqualifiedType() && 677 CanonFrom.getCVRQualifiers() != CanonTo.getCVRQualifiers()) { 678 FromType = ToType; 679 CanonFrom = CanonTo; 680 } 681 } 682 683 // If we have not converted the argument type to the parameter type, 684 // this is a bad conversion sequence. 685 if (CanonFrom != CanonTo) 686 return false; 687 688 SCS.ToTypePtr = FromType.getAsOpaquePtr(); 689 return true; 690} 691 692/// IsIntegralPromotion - Determines whether the conversion from the 693/// expression From (whose potentially-adjusted type is FromType) to 694/// ToType is an integral promotion (C++ 4.5). If so, returns true and 695/// sets PromotedType to the promoted type. 696bool Sema::IsIntegralPromotion(Expr *From, QualType FromType, QualType ToType) { 697 const BuiltinType *To = ToType->getAs<BuiltinType>(); 698 // All integers are built-in. 699 if (!To) { 700 return false; 701 } 702 703 // An rvalue of type char, signed char, unsigned char, short int, or 704 // unsigned short int can be converted to an rvalue of type int if 705 // int can represent all the values of the source type; otherwise, 706 // the source rvalue can be converted to an rvalue of type unsigned 707 // int (C++ 4.5p1). 708 if (FromType->isPromotableIntegerType() && !FromType->isBooleanType()) { 709 if (// We can promote any signed, promotable integer type to an int 710 (FromType->isSignedIntegerType() || 711 // We can promote any unsigned integer type whose size is 712 // less than int to an int. 713 (!FromType->isSignedIntegerType() && 714 Context.getTypeSize(FromType) < Context.getTypeSize(ToType)))) { 715 return To->getKind() == BuiltinType::Int; 716 } 717 718 return To->getKind() == BuiltinType::UInt; 719 } 720 721 // An rvalue of type wchar_t (3.9.1) or an enumeration type (7.2) 722 // can be converted to an rvalue of the first of the following types 723 // that can represent all the values of its underlying type: int, 724 // unsigned int, long, or unsigned long (C++ 4.5p2). 725 if ((FromType->isEnumeralType() || FromType->isWideCharType()) 726 && ToType->isIntegerType()) { 727 // Determine whether the type we're converting from is signed or 728 // unsigned. 729 bool FromIsSigned; 730 uint64_t FromSize = Context.getTypeSize(FromType); 731 if (const EnumType *FromEnumType = FromType->getAs<EnumType>()) { 732 QualType UnderlyingType = FromEnumType->getDecl()->getIntegerType(); 733 FromIsSigned = UnderlyingType->isSignedIntegerType(); 734 } else { 735 // FIXME: Is wchar_t signed or unsigned? We assume it's signed for now. 736 FromIsSigned = true; 737 } 738 739 // The types we'll try to promote to, in the appropriate 740 // order. Try each of these types. 741 QualType PromoteTypes[6] = { 742 Context.IntTy, Context.UnsignedIntTy, 743 Context.LongTy, Context.UnsignedLongTy , 744 Context.LongLongTy, Context.UnsignedLongLongTy 745 }; 746 for (int Idx = 0; Idx < 6; ++Idx) { 747 uint64_t ToSize = Context.getTypeSize(PromoteTypes[Idx]); 748 if (FromSize < ToSize || 749 (FromSize == ToSize && 750 FromIsSigned == PromoteTypes[Idx]->isSignedIntegerType())) { 751 // We found the type that we can promote to. If this is the 752 // type we wanted, we have a promotion. Otherwise, no 753 // promotion. 754 return Context.getCanonicalType(ToType).getUnqualifiedType() 755 == Context.getCanonicalType(PromoteTypes[Idx]).getUnqualifiedType(); 756 } 757 } 758 } 759 760 // An rvalue for an integral bit-field (9.6) can be converted to an 761 // rvalue of type int if int can represent all the values of the 762 // bit-field; otherwise, it can be converted to unsigned int if 763 // unsigned int can represent all the values of the bit-field. If 764 // the bit-field is larger yet, no integral promotion applies to 765 // it. If the bit-field has an enumerated type, it is treated as any 766 // other value of that type for promotion purposes (C++ 4.5p3). 767 // FIXME: We should delay checking of bit-fields until we actually perform the 768 // conversion. 769 using llvm::APSInt; 770 if (From) 771 if (FieldDecl *MemberDecl = From->getBitField()) { 772 APSInt BitWidth; 773 if (FromType->isIntegralType() && !FromType->isEnumeralType() && 774 MemberDecl->getBitWidth()->isIntegerConstantExpr(BitWidth, Context)) { 775 APSInt ToSize(BitWidth.getBitWidth(), BitWidth.isUnsigned()); 776 ToSize = Context.getTypeSize(ToType); 777 778 // Are we promoting to an int from a bitfield that fits in an int? 779 if (BitWidth < ToSize || 780 (FromType->isSignedIntegerType() && BitWidth <= ToSize)) { 781 return To->getKind() == BuiltinType::Int; 782 } 783 784 // Are we promoting to an unsigned int from an unsigned bitfield 785 // that fits into an unsigned int? 786 if (FromType->isUnsignedIntegerType() && BitWidth <= ToSize) { 787 return To->getKind() == BuiltinType::UInt; 788 } 789 790 return false; 791 } 792 } 793 794 // An rvalue of type bool can be converted to an rvalue of type int, 795 // with false becoming zero and true becoming one (C++ 4.5p4). 796 if (FromType->isBooleanType() && To->getKind() == BuiltinType::Int) { 797 return true; 798 } 799 800 return false; 801} 802 803/// IsFloatingPointPromotion - Determines whether the conversion from 804/// FromType to ToType is a floating point promotion (C++ 4.6). If so, 805/// returns true and sets PromotedType to the promoted type. 806bool Sema::IsFloatingPointPromotion(QualType FromType, QualType ToType) { 807 /// An rvalue of type float can be converted to an rvalue of type 808 /// double. (C++ 4.6p1). 809 if (const BuiltinType *FromBuiltin = FromType->getAs<BuiltinType>()) 810 if (const BuiltinType *ToBuiltin = ToType->getAs<BuiltinType>()) { 811 if (FromBuiltin->getKind() == BuiltinType::Float && 812 ToBuiltin->getKind() == BuiltinType::Double) 813 return true; 814 815 // C99 6.3.1.5p1: 816 // When a float is promoted to double or long double, or a 817 // double is promoted to long double [...]. 818 if (!getLangOptions().CPlusPlus && 819 (FromBuiltin->getKind() == BuiltinType::Float || 820 FromBuiltin->getKind() == BuiltinType::Double) && 821 (ToBuiltin->getKind() == BuiltinType::LongDouble)) 822 return true; 823 } 824 825 return false; 826} 827 828/// \brief Determine if a conversion is a complex promotion. 829/// 830/// A complex promotion is defined as a complex -> complex conversion 831/// where the conversion between the underlying real types is a 832/// floating-point or integral promotion. 833bool Sema::IsComplexPromotion(QualType FromType, QualType ToType) { 834 const ComplexType *FromComplex = FromType->getAs<ComplexType>(); 835 if (!FromComplex) 836 return false; 837 838 const ComplexType *ToComplex = ToType->getAs<ComplexType>(); 839 if (!ToComplex) 840 return false; 841 842 return IsFloatingPointPromotion(FromComplex->getElementType(), 843 ToComplex->getElementType()) || 844 IsIntegralPromotion(0, FromComplex->getElementType(), 845 ToComplex->getElementType()); 846} 847 848/// BuildSimilarlyQualifiedPointerType - In a pointer conversion from 849/// the pointer type FromPtr to a pointer to type ToPointee, with the 850/// same type qualifiers as FromPtr has on its pointee type. ToType, 851/// if non-empty, will be a pointer to ToType that may or may not have 852/// the right set of qualifiers on its pointee. 853static QualType 854BuildSimilarlyQualifiedPointerType(const PointerType *FromPtr, 855 QualType ToPointee, QualType ToType, 856 ASTContext &Context) { 857 QualType CanonFromPointee = Context.getCanonicalType(FromPtr->getPointeeType()); 858 QualType CanonToPointee = Context.getCanonicalType(ToPointee); 859 unsigned Quals = CanonFromPointee.getCVRQualifiers(); 860 861 // Exact qualifier match -> return the pointer type we're converting to. 862 if (CanonToPointee.getCVRQualifiers() == Quals) { 863 // ToType is exactly what we need. Return it. 864 if (ToType.getTypePtr()) 865 return ToType; 866 867 // Build a pointer to ToPointee. It has the right qualifiers 868 // already. 869 return Context.getPointerType(ToPointee); 870 } 871 872 // Just build a canonical type that has the right qualifiers. 873 return Context.getPointerType(CanonToPointee.getQualifiedType(Quals)); 874} 875 876static bool isNullPointerConstantForConversion(Expr *Expr, 877 bool InOverloadResolution, 878 ASTContext &Context) { 879 // Handle value-dependent integral null pointer constants correctly. 880 // http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#903 881 if (Expr->isValueDependent() && !Expr->isTypeDependent() && 882 Expr->getType()->isIntegralType()) 883 return !InOverloadResolution; 884 885 return Expr->isNullPointerConstant(Context); 886} 887 888/// IsPointerConversion - Determines whether the conversion of the 889/// expression From, which has the (possibly adjusted) type FromType, 890/// can be converted to the type ToType via a pointer conversion (C++ 891/// 4.10). If so, returns true and places the converted type (that 892/// might differ from ToType in its cv-qualifiers at some level) into 893/// ConvertedType. 894/// 895/// This routine also supports conversions to and from block pointers 896/// and conversions with Objective-C's 'id', 'id<protocols...>', and 897/// pointers to interfaces. FIXME: Once we've determined the 898/// appropriate overloading rules for Objective-C, we may want to 899/// split the Objective-C checks into a different routine; however, 900/// GCC seems to consider all of these conversions to be pointer 901/// conversions, so for now they live here. IncompatibleObjC will be 902/// set if the conversion is an allowed Objective-C conversion that 903/// should result in a warning. 904bool Sema::IsPointerConversion(Expr *From, QualType FromType, QualType ToType, 905 bool InOverloadResolution, 906 QualType& ConvertedType, 907 bool &IncompatibleObjC) { 908 IncompatibleObjC = false; 909 if (isObjCPointerConversion(FromType, ToType, ConvertedType, IncompatibleObjC)) 910 return true; 911 912 // Conversion from a null pointer constant to any Objective-C pointer type. 913 if (ToType->isObjCObjectPointerType() && 914 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 915 ConvertedType = ToType; 916 return true; 917 } 918 919 // Blocks: Block pointers can be converted to void*. 920 if (FromType->isBlockPointerType() && ToType->isPointerType() && 921 ToType->getAs<PointerType>()->getPointeeType()->isVoidType()) { 922 ConvertedType = ToType; 923 return true; 924 } 925 // Blocks: A null pointer constant can be converted to a block 926 // pointer type. 927 if (ToType->isBlockPointerType() && 928 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 929 ConvertedType = ToType; 930 return true; 931 } 932 933 // If the left-hand-side is nullptr_t, the right side can be a null 934 // pointer constant. 935 if (ToType->isNullPtrType() && 936 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 937 ConvertedType = ToType; 938 return true; 939 } 940 941 const PointerType* ToTypePtr = ToType->getAs<PointerType>(); 942 if (!ToTypePtr) 943 return false; 944 945 // A null pointer constant can be converted to a pointer type (C++ 4.10p1). 946 if (isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 947 ConvertedType = ToType; 948 return true; 949 } 950 951 // Beyond this point, both types need to be pointers. 952 const PointerType *FromTypePtr = FromType->getAs<PointerType>(); 953 if (!FromTypePtr) 954 return false; 955 956 QualType FromPointeeType = FromTypePtr->getPointeeType(); 957 QualType ToPointeeType = ToTypePtr->getPointeeType(); 958 959 // An rvalue of type "pointer to cv T," where T is an object type, 960 // can be converted to an rvalue of type "pointer to cv void" (C++ 961 // 4.10p2). 962 if (FromPointeeType->isObjectType() && ToPointeeType->isVoidType()) { 963 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 964 ToPointeeType, 965 ToType, Context); 966 return true; 967 } 968 969 // When we're overloading in C, we allow a special kind of pointer 970 // conversion for compatible-but-not-identical pointee types. 971 if (!getLangOptions().CPlusPlus && 972 Context.typesAreCompatible(FromPointeeType, ToPointeeType)) { 973 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 974 ToPointeeType, 975 ToType, Context); 976 return true; 977 } 978 979 // C++ [conv.ptr]p3: 980 // 981 // An rvalue of type "pointer to cv D," where D is a class type, 982 // can be converted to an rvalue of type "pointer to cv B," where 983 // B is a base class (clause 10) of D. If B is an inaccessible 984 // (clause 11) or ambiguous (10.2) base class of D, a program that 985 // necessitates this conversion is ill-formed. The result of the 986 // conversion is a pointer to the base class sub-object of the 987 // derived class object. The null pointer value is converted to 988 // the null pointer value of the destination type. 989 // 990 // Note that we do not check for ambiguity or inaccessibility 991 // here. That is handled by CheckPointerConversion. 992 if (getLangOptions().CPlusPlus && 993 FromPointeeType->isRecordType() && ToPointeeType->isRecordType() && 994 IsDerivedFrom(FromPointeeType, ToPointeeType)) { 995 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 996 ToPointeeType, 997 ToType, Context); 998 return true; 999 } 1000 1001 return false; 1002} 1003 1004/// isObjCPointerConversion - Determines whether this is an 1005/// Objective-C pointer conversion. Subroutine of IsPointerConversion, 1006/// with the same arguments and return values. 1007bool Sema::isObjCPointerConversion(QualType FromType, QualType ToType, 1008 QualType& ConvertedType, 1009 bool &IncompatibleObjC) { 1010 if (!getLangOptions().ObjC1) 1011 return false; 1012 1013 // First, we handle all conversions on ObjC object pointer types. 1014 const ObjCObjectPointerType* ToObjCPtr = ToType->getAs<ObjCObjectPointerType>(); 1015 const ObjCObjectPointerType *FromObjCPtr = 1016 FromType->getAs<ObjCObjectPointerType>(); 1017 1018 if (ToObjCPtr && FromObjCPtr) { 1019 // Objective C++: We're able to convert between "id" or "Class" and a 1020 // pointer to any interface (in both directions). 1021 if (ToObjCPtr->isObjCBuiltinType() && FromObjCPtr->isObjCBuiltinType()) { 1022 ConvertedType = ToType; 1023 return true; 1024 } 1025 // Conversions with Objective-C's id<...>. 1026 if ((FromObjCPtr->isObjCQualifiedIdType() || 1027 ToObjCPtr->isObjCQualifiedIdType()) && 1028 Context.ObjCQualifiedIdTypesAreCompatible(ToType, FromType, 1029 /*compare=*/false)) { 1030 ConvertedType = ToType; 1031 return true; 1032 } 1033 // Objective C++: We're able to convert from a pointer to an 1034 // interface to a pointer to a different interface. 1035 if (Context.canAssignObjCInterfaces(ToObjCPtr, FromObjCPtr)) { 1036 ConvertedType = ToType; 1037 return true; 1038 } 1039 1040 if (Context.canAssignObjCInterfaces(FromObjCPtr, ToObjCPtr)) { 1041 // Okay: this is some kind of implicit downcast of Objective-C 1042 // interfaces, which is permitted. However, we're going to 1043 // complain about it. 1044 IncompatibleObjC = true; 1045 ConvertedType = FromType; 1046 return true; 1047 } 1048 } 1049 // Beyond this point, both types need to be C pointers or block pointers. 1050 QualType ToPointeeType; 1051 if (const PointerType *ToCPtr = ToType->getAs<PointerType>()) 1052 ToPointeeType = ToCPtr->getPointeeType(); 1053 else if (const BlockPointerType *ToBlockPtr = ToType->getAs<BlockPointerType>()) 1054 ToPointeeType = ToBlockPtr->getPointeeType(); 1055 else 1056 return false; 1057 1058 QualType FromPointeeType; 1059 if (const PointerType *FromCPtr = FromType->getAs<PointerType>()) 1060 FromPointeeType = FromCPtr->getPointeeType(); 1061 else if (const BlockPointerType *FromBlockPtr = FromType->getAs<BlockPointerType>()) 1062 FromPointeeType = FromBlockPtr->getPointeeType(); 1063 else 1064 return false; 1065 1066 // If we have pointers to pointers, recursively check whether this 1067 // is an Objective-C conversion. 1068 if (FromPointeeType->isPointerType() && ToPointeeType->isPointerType() && 1069 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, 1070 IncompatibleObjC)) { 1071 // We always complain about this conversion. 1072 IncompatibleObjC = true; 1073 ConvertedType = ToType; 1074 return true; 1075 } 1076 // If we have pointers to functions or blocks, check whether the only 1077 // differences in the argument and result types are in Objective-C 1078 // pointer conversions. If so, we permit the conversion (but 1079 // complain about it). 1080 const FunctionProtoType *FromFunctionType 1081 = FromPointeeType->getAs<FunctionProtoType>(); 1082 const FunctionProtoType *ToFunctionType 1083 = ToPointeeType->getAs<FunctionProtoType>(); 1084 if (FromFunctionType && ToFunctionType) { 1085 // If the function types are exactly the same, this isn't an 1086 // Objective-C pointer conversion. 1087 if (Context.getCanonicalType(FromPointeeType) 1088 == Context.getCanonicalType(ToPointeeType)) 1089 return false; 1090 1091 // Perform the quick checks that will tell us whether these 1092 // function types are obviously different. 1093 if (FromFunctionType->getNumArgs() != ToFunctionType->getNumArgs() || 1094 FromFunctionType->isVariadic() != ToFunctionType->isVariadic() || 1095 FromFunctionType->getTypeQuals() != ToFunctionType->getTypeQuals()) 1096 return false; 1097 1098 bool HasObjCConversion = false; 1099 if (Context.getCanonicalType(FromFunctionType->getResultType()) 1100 == Context.getCanonicalType(ToFunctionType->getResultType())) { 1101 // Okay, the types match exactly. Nothing to do. 1102 } else if (isObjCPointerConversion(FromFunctionType->getResultType(), 1103 ToFunctionType->getResultType(), 1104 ConvertedType, IncompatibleObjC)) { 1105 // Okay, we have an Objective-C pointer conversion. 1106 HasObjCConversion = true; 1107 } else { 1108 // Function types are too different. Abort. 1109 return false; 1110 } 1111 1112 // Check argument types. 1113 for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumArgs(); 1114 ArgIdx != NumArgs; ++ArgIdx) { 1115 QualType FromArgType = FromFunctionType->getArgType(ArgIdx); 1116 QualType ToArgType = ToFunctionType->getArgType(ArgIdx); 1117 if (Context.getCanonicalType(FromArgType) 1118 == Context.getCanonicalType(ToArgType)) { 1119 // Okay, the types match exactly. Nothing to do. 1120 } else if (isObjCPointerConversion(FromArgType, ToArgType, 1121 ConvertedType, IncompatibleObjC)) { 1122 // Okay, we have an Objective-C pointer conversion. 1123 HasObjCConversion = true; 1124 } else { 1125 // Argument types are too different. Abort. 1126 return false; 1127 } 1128 } 1129 1130 if (HasObjCConversion) { 1131 // We had an Objective-C conversion. Allow this pointer 1132 // conversion, but complain about it. 1133 ConvertedType = ToType; 1134 IncompatibleObjC = true; 1135 return true; 1136 } 1137 } 1138 1139 return false; 1140} 1141 1142/// CheckPointerConversion - Check the pointer conversion from the 1143/// expression From to the type ToType. This routine checks for 1144/// ambiguous or inaccessible derived-to-base pointer 1145/// conversions for which IsPointerConversion has already returned 1146/// true. It returns true and produces a diagnostic if there was an 1147/// error, or returns false otherwise. 1148bool Sema::CheckPointerConversion(Expr *From, QualType ToType, 1149 CastExpr::CastKind &Kind) { 1150 QualType FromType = From->getType(); 1151 1152 if (const PointerType *FromPtrType = FromType->getAs<PointerType>()) 1153 if (const PointerType *ToPtrType = ToType->getAs<PointerType>()) { 1154 QualType FromPointeeType = FromPtrType->getPointeeType(), 1155 ToPointeeType = ToPtrType->getPointeeType(); 1156 1157 if (FromPointeeType->isRecordType() && 1158 ToPointeeType->isRecordType()) { 1159 // We must have a derived-to-base conversion. Check an 1160 // ambiguous or inaccessible conversion. 1161 if (CheckDerivedToBaseConversion(FromPointeeType, ToPointeeType, 1162 From->getExprLoc(), 1163 From->getSourceRange())) 1164 return true; 1165 1166 // The conversion was successful. 1167 Kind = CastExpr::CK_DerivedToBase; 1168 } 1169 } 1170 if (const ObjCObjectPointerType *FromPtrType = 1171 FromType->getAs<ObjCObjectPointerType>()) 1172 if (const ObjCObjectPointerType *ToPtrType = 1173 ToType->getAs<ObjCObjectPointerType>()) { 1174 // Objective-C++ conversions are always okay. 1175 // FIXME: We should have a different class of conversions for the 1176 // Objective-C++ implicit conversions. 1177 if (FromPtrType->isObjCBuiltinType() || ToPtrType->isObjCBuiltinType()) 1178 return false; 1179 1180 } 1181 return false; 1182} 1183 1184/// IsMemberPointerConversion - Determines whether the conversion of the 1185/// expression From, which has the (possibly adjusted) type FromType, can be 1186/// converted to the type ToType via a member pointer conversion (C++ 4.11). 1187/// If so, returns true and places the converted type (that might differ from 1188/// ToType in its cv-qualifiers at some level) into ConvertedType. 1189bool Sema::IsMemberPointerConversion(Expr *From, QualType FromType, 1190 QualType ToType, QualType &ConvertedType) { 1191 const MemberPointerType *ToTypePtr = ToType->getAs<MemberPointerType>(); 1192 if (!ToTypePtr) 1193 return false; 1194 1195 // A null pointer constant can be converted to a member pointer (C++ 4.11p1) 1196 if (From->isNullPointerConstant(Context)) { 1197 ConvertedType = ToType; 1198 return true; 1199 } 1200 1201 // Otherwise, both types have to be member pointers. 1202 const MemberPointerType *FromTypePtr = FromType->getAs<MemberPointerType>(); 1203 if (!FromTypePtr) 1204 return false; 1205 1206 // A pointer to member of B can be converted to a pointer to member of D, 1207 // where D is derived from B (C++ 4.11p2). 1208 QualType FromClass(FromTypePtr->getClass(), 0); 1209 QualType ToClass(ToTypePtr->getClass(), 0); 1210 // FIXME: What happens when these are dependent? Is this function even called? 1211 1212 if (IsDerivedFrom(ToClass, FromClass)) { 1213 ConvertedType = Context.getMemberPointerType(FromTypePtr->getPointeeType(), 1214 ToClass.getTypePtr()); 1215 return true; 1216 } 1217 1218 return false; 1219} 1220 1221/// CheckMemberPointerConversion - Check the member pointer conversion from the 1222/// expression From to the type ToType. This routine checks for ambiguous or 1223/// virtual (FIXME: or inaccessible) base-to-derived member pointer conversions 1224/// for which IsMemberPointerConversion has already returned true. It returns 1225/// true and produces a diagnostic if there was an error, or returns false 1226/// otherwise. 1227bool Sema::CheckMemberPointerConversion(Expr *From, QualType ToType, 1228 CastExpr::CastKind &Kind) { 1229 QualType FromType = From->getType(); 1230 const MemberPointerType *FromPtrType = FromType->getAs<MemberPointerType>(); 1231 if (!FromPtrType) { 1232 // This must be a null pointer to member pointer conversion 1233 assert(From->isNullPointerConstant(Context) && 1234 "Expr must be null pointer constant!"); 1235 Kind = CastExpr::CK_NullToMemberPointer; 1236 return false; 1237 } 1238 1239 const MemberPointerType *ToPtrType = ToType->getAs<MemberPointerType>(); 1240 assert(ToPtrType && "No member pointer cast has a target type " 1241 "that is not a member pointer."); 1242 1243 QualType FromClass = QualType(FromPtrType->getClass(), 0); 1244 QualType ToClass = QualType(ToPtrType->getClass(), 0); 1245 1246 // FIXME: What about dependent types? 1247 assert(FromClass->isRecordType() && "Pointer into non-class."); 1248 assert(ToClass->isRecordType() && "Pointer into non-class."); 1249 1250 BasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/false, 1251 /*DetectVirtual=*/true); 1252 bool DerivationOkay = IsDerivedFrom(ToClass, FromClass, Paths); 1253 assert(DerivationOkay && 1254 "Should not have been called if derivation isn't OK."); 1255 (void)DerivationOkay; 1256 1257 if (Paths.isAmbiguous(Context.getCanonicalType(FromClass). 1258 getUnqualifiedType())) { 1259 // Derivation is ambiguous. Redo the check to find the exact paths. 1260 Paths.clear(); 1261 Paths.setRecordingPaths(true); 1262 bool StillOkay = IsDerivedFrom(ToClass, FromClass, Paths); 1263 assert(StillOkay && "Derivation changed due to quantum fluctuation."); 1264 (void)StillOkay; 1265 1266 std::string PathDisplayStr = getAmbiguousPathsDisplayString(Paths); 1267 Diag(From->getExprLoc(), diag::err_ambiguous_memptr_conv) 1268 << 0 << FromClass << ToClass << PathDisplayStr << From->getSourceRange(); 1269 return true; 1270 } 1271 1272 if (const RecordType *VBase = Paths.getDetectedVirtual()) { 1273 Diag(From->getExprLoc(), diag::err_memptr_conv_via_virtual) 1274 << FromClass << ToClass << QualType(VBase, 0) 1275 << From->getSourceRange(); 1276 return true; 1277 } 1278 1279 // Must be a base to derived member conversion. 1280 Kind = CastExpr::CK_BaseToDerivedMemberPointer; 1281 return false; 1282} 1283 1284/// IsQualificationConversion - Determines whether the conversion from 1285/// an rvalue of type FromType to ToType is a qualification conversion 1286/// (C++ 4.4). 1287bool 1288Sema::IsQualificationConversion(QualType FromType, QualType ToType) { 1289 FromType = Context.getCanonicalType(FromType); 1290 ToType = Context.getCanonicalType(ToType); 1291 1292 // If FromType and ToType are the same type, this is not a 1293 // qualification conversion. 1294 if (FromType == ToType) 1295 return false; 1296 1297 // (C++ 4.4p4): 1298 // A conversion can add cv-qualifiers at levels other than the first 1299 // in multi-level pointers, subject to the following rules: [...] 1300 bool PreviousToQualsIncludeConst = true; 1301 bool UnwrappedAnyPointer = false; 1302 while (UnwrapSimilarPointerTypes(FromType, ToType)) { 1303 // Within each iteration of the loop, we check the qualifiers to 1304 // determine if this still looks like a qualification 1305 // conversion. Then, if all is well, we unwrap one more level of 1306 // pointers or pointers-to-members and do it all again 1307 // until there are no more pointers or pointers-to-members left to 1308 // unwrap. 1309 UnwrappedAnyPointer = true; 1310 1311 // -- for every j > 0, if const is in cv 1,j then const is in cv 1312 // 2,j, and similarly for volatile. 1313 if (!ToType.isAtLeastAsQualifiedAs(FromType)) 1314 return false; 1315 1316 // -- if the cv 1,j and cv 2,j are different, then const is in 1317 // every cv for 0 < k < j. 1318 if (FromType.getCVRQualifiers() != ToType.getCVRQualifiers() 1319 && !PreviousToQualsIncludeConst) 1320 return false; 1321 1322 // Keep track of whether all prior cv-qualifiers in the "to" type 1323 // include const. 1324 PreviousToQualsIncludeConst 1325 = PreviousToQualsIncludeConst && ToType.isConstQualified(); 1326 } 1327 1328 // We are left with FromType and ToType being the pointee types 1329 // after unwrapping the original FromType and ToType the same number 1330 // of types. If we unwrapped any pointers, and if FromType and 1331 // ToType have the same unqualified type (since we checked 1332 // qualifiers above), then this is a qualification conversion. 1333 return UnwrappedAnyPointer && 1334 FromType.getUnqualifiedType() == ToType.getUnqualifiedType(); 1335} 1336 1337/// \brief Given a function template or function, extract the function template 1338/// declaration (if any) and the underlying function declaration. 1339template<typename T> 1340static void GetFunctionAndTemplate(AnyFunctionDecl Orig, T *&Function, 1341 FunctionTemplateDecl *&FunctionTemplate) { 1342 FunctionTemplate = dyn_cast<FunctionTemplateDecl>(Orig); 1343 if (FunctionTemplate) 1344 Function = cast<T>(FunctionTemplate->getTemplatedDecl()); 1345 else 1346 Function = cast<T>(Orig); 1347} 1348 1349/// Determines whether there is a user-defined conversion sequence 1350/// (C++ [over.ics.user]) that converts expression From to the type 1351/// ToType. If such a conversion exists, User will contain the 1352/// user-defined conversion sequence that performs such a conversion 1353/// and this routine will return true. Otherwise, this routine returns 1354/// false and User is unspecified. 1355/// 1356/// \param AllowConversionFunctions true if the conversion should 1357/// consider conversion functions at all. If false, only constructors 1358/// will be considered. 1359/// 1360/// \param AllowExplicit true if the conversion should consider C++0x 1361/// "explicit" conversion functions as well as non-explicit conversion 1362/// functions (C++0x [class.conv.fct]p2). 1363/// 1364/// \param ForceRValue true if the expression should be treated as an rvalue 1365/// for overload resolution. 1366Sema::OverloadingResult Sema::IsUserDefinedConversion( 1367 Expr *From, QualType ToType, 1368 UserDefinedConversionSequence& User, 1369 OverloadCandidateSet& CandidateSet, 1370 bool AllowConversionFunctions, 1371 bool AllowExplicit, bool ForceRValue) { 1372 if (const RecordType *ToRecordType = ToType->getAs<RecordType>()) { 1373 if (CXXRecordDecl *ToRecordDecl 1374 = dyn_cast<CXXRecordDecl>(ToRecordType->getDecl())) { 1375 // C++ [over.match.ctor]p1: 1376 // When objects of class type are direct-initialized (8.5), or 1377 // copy-initialized from an expression of the same or a 1378 // derived class type (8.5), overload resolution selects the 1379 // constructor. [...] For copy-initialization, the candidate 1380 // functions are all the converting constructors (12.3.1) of 1381 // that class. The argument list is the expression-list within 1382 // the parentheses of the initializer. 1383 DeclarationName ConstructorName 1384 = Context.DeclarationNames.getCXXConstructorName( 1385 Context.getCanonicalType(ToType).getUnqualifiedType()); 1386 DeclContext::lookup_iterator Con, ConEnd; 1387 for (llvm::tie(Con, ConEnd) 1388 = ToRecordDecl->lookup(ConstructorName); 1389 Con != ConEnd; ++Con) { 1390 // Find the constructor (which may be a template). 1391 CXXConstructorDecl *Constructor = 0; 1392 FunctionTemplateDecl *ConstructorTmpl 1393 = dyn_cast<FunctionTemplateDecl>(*Con); 1394 if (ConstructorTmpl) 1395 Constructor 1396 = cast<CXXConstructorDecl>(ConstructorTmpl->getTemplatedDecl()); 1397 else 1398 Constructor = cast<CXXConstructorDecl>(*Con); 1399 1400 if (!Constructor->isInvalidDecl() && 1401 Constructor->isConvertingConstructor(AllowExplicit)) { 1402 if (ConstructorTmpl) 1403 AddTemplateOverloadCandidate(ConstructorTmpl, false, 0, 0, &From, 1404 1, CandidateSet, 1405 /*SuppressUserConversions=*/true, 1406 ForceRValue); 1407 else 1408 AddOverloadCandidate(Constructor, &From, 1, CandidateSet, 1409 /*SuppressUserConversions=*/true, ForceRValue); 1410 } 1411 } 1412 } 1413 } 1414 1415 if (!AllowConversionFunctions) { 1416 // Don't allow any conversion functions to enter the overload set. 1417 } else if (RequireCompleteType(From->getLocStart(), From->getType(), 1418 PDiag(0) 1419 << From->getSourceRange())) { 1420 // No conversion functions from incomplete types. 1421 } else if (const RecordType *FromRecordType 1422 = From->getType()->getAs<RecordType>()) { 1423 if (CXXRecordDecl *FromRecordDecl 1424 = dyn_cast<CXXRecordDecl>(FromRecordType->getDecl())) { 1425 // Add all of the conversion functions as candidates. 1426 OverloadedFunctionDecl *Conversions 1427 = FromRecordDecl->getVisibleConversionFunctions(); 1428 for (OverloadedFunctionDecl::function_iterator Func 1429 = Conversions->function_begin(); 1430 Func != Conversions->function_end(); ++Func) { 1431 CXXConversionDecl *Conv; 1432 FunctionTemplateDecl *ConvTemplate; 1433 GetFunctionAndTemplate(*Func, Conv, ConvTemplate); 1434 if (ConvTemplate) 1435 Conv = dyn_cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 1436 else 1437 Conv = dyn_cast<CXXConversionDecl>(*Func); 1438 1439 if (AllowExplicit || !Conv->isExplicit()) { 1440 if (ConvTemplate) 1441 AddTemplateConversionCandidate(ConvTemplate, From, ToType, 1442 CandidateSet); 1443 else 1444 AddConversionCandidate(Conv, From, ToType, CandidateSet); 1445 } 1446 } 1447 } 1448 } 1449 1450 OverloadCandidateSet::iterator Best; 1451 switch (BestViableFunction(CandidateSet, From->getLocStart(), Best)) { 1452 case OR_Success: 1453 // Record the standard conversion we used and the conversion function. 1454 if (CXXConstructorDecl *Constructor 1455 = dyn_cast<CXXConstructorDecl>(Best->Function)) { 1456 // C++ [over.ics.user]p1: 1457 // If the user-defined conversion is specified by a 1458 // constructor (12.3.1), the initial standard conversion 1459 // sequence converts the source type to the type required by 1460 // the argument of the constructor. 1461 // 1462 // FIXME: What about ellipsis conversions? 1463 QualType ThisType = Constructor->getThisType(Context); 1464 User.Before = Best->Conversions[0].Standard; 1465 User.ConversionFunction = Constructor; 1466 User.After.setAsIdentityConversion(); 1467 User.After.FromTypePtr 1468 = ThisType->getAs<PointerType>()->getPointeeType().getAsOpaquePtr(); 1469 User.After.ToTypePtr = ToType.getAsOpaquePtr(); 1470 return OR_Success; 1471 } else if (CXXConversionDecl *Conversion 1472 = dyn_cast<CXXConversionDecl>(Best->Function)) { 1473 // C++ [over.ics.user]p1: 1474 // 1475 // [...] If the user-defined conversion is specified by a 1476 // conversion function (12.3.2), the initial standard 1477 // conversion sequence converts the source type to the 1478 // implicit object parameter of the conversion function. 1479 User.Before = Best->Conversions[0].Standard; 1480 User.ConversionFunction = Conversion; 1481 1482 // C++ [over.ics.user]p2: 1483 // The second standard conversion sequence converts the 1484 // result of the user-defined conversion to the target type 1485 // for the sequence. Since an implicit conversion sequence 1486 // is an initialization, the special rules for 1487 // initialization by user-defined conversion apply when 1488 // selecting the best user-defined conversion for a 1489 // user-defined conversion sequence (see 13.3.3 and 1490 // 13.3.3.1). 1491 User.After = Best->FinalConversion; 1492 return OR_Success; 1493 } else { 1494 assert(false && "Not a constructor or conversion function?"); 1495 return OR_No_Viable_Function; 1496 } 1497 1498 case OR_No_Viable_Function: 1499 return OR_No_Viable_Function; 1500 case OR_Deleted: 1501 // No conversion here! We're done. 1502 return OR_Deleted; 1503 1504 case OR_Ambiguous: 1505 // FIXME: See C++ [over.best.ics]p10 for the handling of 1506 // ambiguous conversion sequences. 1507 return OR_Ambiguous; 1508 } 1509 1510 return OR_No_Viable_Function; 1511} 1512 1513bool 1514Sema::DiagnoseAmbiguousUserDefinedConversion(Expr *From, QualType ToType) { 1515 ImplicitConversionSequence ICS; 1516 OverloadCandidateSet CandidateSet; 1517 OverloadingResult OvResult = 1518 IsUserDefinedConversion(From, ToType, ICS.UserDefined, 1519 CandidateSet, true, false, false); 1520 if (OvResult != OR_Ambiguous) 1521 return false; 1522 Diag(From->getSourceRange().getBegin(), 1523 diag::err_typecheck_ambiguous_condition) 1524 << From->getType() << ToType << From->getSourceRange(); 1525 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 1526 return true; 1527} 1528 1529/// CompareImplicitConversionSequences - Compare two implicit 1530/// conversion sequences to determine whether one is better than the 1531/// other or if they are indistinguishable (C++ 13.3.3.2). 1532ImplicitConversionSequence::CompareKind 1533Sema::CompareImplicitConversionSequences(const ImplicitConversionSequence& ICS1, 1534 const ImplicitConversionSequence& ICS2) 1535{ 1536 // (C++ 13.3.3.2p2): When comparing the basic forms of implicit 1537 // conversion sequences (as defined in 13.3.3.1) 1538 // -- a standard conversion sequence (13.3.3.1.1) is a better 1539 // conversion sequence than a user-defined conversion sequence or 1540 // an ellipsis conversion sequence, and 1541 // -- a user-defined conversion sequence (13.3.3.1.2) is a better 1542 // conversion sequence than an ellipsis conversion sequence 1543 // (13.3.3.1.3). 1544 // 1545 if (ICS1.ConversionKind < ICS2.ConversionKind) 1546 return ImplicitConversionSequence::Better; 1547 else if (ICS2.ConversionKind < ICS1.ConversionKind) 1548 return ImplicitConversionSequence::Worse; 1549 1550 // Two implicit conversion sequences of the same form are 1551 // indistinguishable conversion sequences unless one of the 1552 // following rules apply: (C++ 13.3.3.2p3): 1553 if (ICS1.ConversionKind == ImplicitConversionSequence::StandardConversion) 1554 return CompareStandardConversionSequences(ICS1.Standard, ICS2.Standard); 1555 else if (ICS1.ConversionKind == 1556 ImplicitConversionSequence::UserDefinedConversion) { 1557 // User-defined conversion sequence U1 is a better conversion 1558 // sequence than another user-defined conversion sequence U2 if 1559 // they contain the same user-defined conversion function or 1560 // constructor and if the second standard conversion sequence of 1561 // U1 is better than the second standard conversion sequence of 1562 // U2 (C++ 13.3.3.2p3). 1563 if (ICS1.UserDefined.ConversionFunction == 1564 ICS2.UserDefined.ConversionFunction) 1565 return CompareStandardConversionSequences(ICS1.UserDefined.After, 1566 ICS2.UserDefined.After); 1567 } 1568 1569 return ImplicitConversionSequence::Indistinguishable; 1570} 1571 1572/// CompareStandardConversionSequences - Compare two standard 1573/// conversion sequences to determine whether one is better than the 1574/// other or if they are indistinguishable (C++ 13.3.3.2p3). 1575ImplicitConversionSequence::CompareKind 1576Sema::CompareStandardConversionSequences(const StandardConversionSequence& SCS1, 1577 const StandardConversionSequence& SCS2) 1578{ 1579 // Standard conversion sequence S1 is a better conversion sequence 1580 // than standard conversion sequence S2 if (C++ 13.3.3.2p3): 1581 1582 // -- S1 is a proper subsequence of S2 (comparing the conversion 1583 // sequences in the canonical form defined by 13.3.3.1.1, 1584 // excluding any Lvalue Transformation; the identity conversion 1585 // sequence is considered to be a subsequence of any 1586 // non-identity conversion sequence) or, if not that, 1587 if (SCS1.Second == SCS2.Second && SCS1.Third == SCS2.Third) 1588 // Neither is a proper subsequence of the other. Do nothing. 1589 ; 1590 else if ((SCS1.Second == ICK_Identity && SCS1.Third == SCS2.Third) || 1591 (SCS1.Third == ICK_Identity && SCS1.Second == SCS2.Second) || 1592 (SCS1.Second == ICK_Identity && 1593 SCS1.Third == ICK_Identity)) 1594 // SCS1 is a proper subsequence of SCS2. 1595 return ImplicitConversionSequence::Better; 1596 else if ((SCS2.Second == ICK_Identity && SCS2.Third == SCS1.Third) || 1597 (SCS2.Third == ICK_Identity && SCS2.Second == SCS1.Second) || 1598 (SCS2.Second == ICK_Identity && 1599 SCS2.Third == ICK_Identity)) 1600 // SCS2 is a proper subsequence of SCS1. 1601 return ImplicitConversionSequence::Worse; 1602 1603 // -- the rank of S1 is better than the rank of S2 (by the rules 1604 // defined below), or, if not that, 1605 ImplicitConversionRank Rank1 = SCS1.getRank(); 1606 ImplicitConversionRank Rank2 = SCS2.getRank(); 1607 if (Rank1 < Rank2) 1608 return ImplicitConversionSequence::Better; 1609 else if (Rank2 < Rank1) 1610 return ImplicitConversionSequence::Worse; 1611 1612 // (C++ 13.3.3.2p4): Two conversion sequences with the same rank 1613 // are indistinguishable unless one of the following rules 1614 // applies: 1615 1616 // A conversion that is not a conversion of a pointer, or 1617 // pointer to member, to bool is better than another conversion 1618 // that is such a conversion. 1619 if (SCS1.isPointerConversionToBool() != SCS2.isPointerConversionToBool()) 1620 return SCS2.isPointerConversionToBool() 1621 ? ImplicitConversionSequence::Better 1622 : ImplicitConversionSequence::Worse; 1623 1624 // C++ [over.ics.rank]p4b2: 1625 // 1626 // If class B is derived directly or indirectly from class A, 1627 // conversion of B* to A* is better than conversion of B* to 1628 // void*, and conversion of A* to void* is better than conversion 1629 // of B* to void*. 1630 bool SCS1ConvertsToVoid 1631 = SCS1.isPointerConversionToVoidPointer(Context); 1632 bool SCS2ConvertsToVoid 1633 = SCS2.isPointerConversionToVoidPointer(Context); 1634 if (SCS1ConvertsToVoid != SCS2ConvertsToVoid) { 1635 // Exactly one of the conversion sequences is a conversion to 1636 // a void pointer; it's the worse conversion. 1637 return SCS2ConvertsToVoid ? ImplicitConversionSequence::Better 1638 : ImplicitConversionSequence::Worse; 1639 } else if (!SCS1ConvertsToVoid && !SCS2ConvertsToVoid) { 1640 // Neither conversion sequence converts to a void pointer; compare 1641 // their derived-to-base conversions. 1642 if (ImplicitConversionSequence::CompareKind DerivedCK 1643 = CompareDerivedToBaseConversions(SCS1, SCS2)) 1644 return DerivedCK; 1645 } else if (SCS1ConvertsToVoid && SCS2ConvertsToVoid) { 1646 // Both conversion sequences are conversions to void 1647 // pointers. Compare the source types to determine if there's an 1648 // inheritance relationship in their sources. 1649 QualType FromType1 = QualType::getFromOpaquePtr(SCS1.FromTypePtr); 1650 QualType FromType2 = QualType::getFromOpaquePtr(SCS2.FromTypePtr); 1651 1652 // Adjust the types we're converting from via the array-to-pointer 1653 // conversion, if we need to. 1654 if (SCS1.First == ICK_Array_To_Pointer) 1655 FromType1 = Context.getArrayDecayedType(FromType1); 1656 if (SCS2.First == ICK_Array_To_Pointer) 1657 FromType2 = Context.getArrayDecayedType(FromType2); 1658 1659 QualType FromPointee1 1660 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1661 QualType FromPointee2 1662 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1663 1664 if (IsDerivedFrom(FromPointee2, FromPointee1)) 1665 return ImplicitConversionSequence::Better; 1666 else if (IsDerivedFrom(FromPointee1, FromPointee2)) 1667 return ImplicitConversionSequence::Worse; 1668 1669 // Objective-C++: If one interface is more specific than the 1670 // other, it is the better one. 1671 const ObjCInterfaceType* FromIface1 = FromPointee1->getAs<ObjCInterfaceType>(); 1672 const ObjCInterfaceType* FromIface2 = FromPointee2->getAs<ObjCInterfaceType>(); 1673 if (FromIface1 && FromIface1) { 1674 if (Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 1675 return ImplicitConversionSequence::Better; 1676 else if (Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 1677 return ImplicitConversionSequence::Worse; 1678 } 1679 } 1680 1681 // Compare based on qualification conversions (C++ 13.3.3.2p3, 1682 // bullet 3). 1683 if (ImplicitConversionSequence::CompareKind QualCK 1684 = CompareQualificationConversions(SCS1, SCS2)) 1685 return QualCK; 1686 1687 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding) { 1688 // C++0x [over.ics.rank]p3b4: 1689 // -- S1 and S2 are reference bindings (8.5.3) and neither refers to an 1690 // implicit object parameter of a non-static member function declared 1691 // without a ref-qualifier, and S1 binds an rvalue reference to an 1692 // rvalue and S2 binds an lvalue reference. 1693 // FIXME: We don't know if we're dealing with the implicit object parameter, 1694 // or if the member function in this case has a ref qualifier. 1695 // (Of course, we don't have ref qualifiers yet.) 1696 if (SCS1.RRefBinding != SCS2.RRefBinding) 1697 return SCS1.RRefBinding ? ImplicitConversionSequence::Better 1698 : ImplicitConversionSequence::Worse; 1699 1700 // C++ [over.ics.rank]p3b4: 1701 // -- S1 and S2 are reference bindings (8.5.3), and the types to 1702 // which the references refer are the same type except for 1703 // top-level cv-qualifiers, and the type to which the reference 1704 // initialized by S2 refers is more cv-qualified than the type 1705 // to which the reference initialized by S1 refers. 1706 QualType T1 = QualType::getFromOpaquePtr(SCS1.ToTypePtr); 1707 QualType T2 = QualType::getFromOpaquePtr(SCS2.ToTypePtr); 1708 T1 = Context.getCanonicalType(T1); 1709 T2 = Context.getCanonicalType(T2); 1710 if (T1.getUnqualifiedType() == T2.getUnqualifiedType()) { 1711 if (T2.isMoreQualifiedThan(T1)) 1712 return ImplicitConversionSequence::Better; 1713 else if (T1.isMoreQualifiedThan(T2)) 1714 return ImplicitConversionSequence::Worse; 1715 } 1716 } 1717 1718 return ImplicitConversionSequence::Indistinguishable; 1719} 1720 1721/// CompareQualificationConversions - Compares two standard conversion 1722/// sequences to determine whether they can be ranked based on their 1723/// qualification conversions (C++ 13.3.3.2p3 bullet 3). 1724ImplicitConversionSequence::CompareKind 1725Sema::CompareQualificationConversions(const StandardConversionSequence& SCS1, 1726 const StandardConversionSequence& SCS2) { 1727 // C++ 13.3.3.2p3: 1728 // -- S1 and S2 differ only in their qualification conversion and 1729 // yield similar types T1 and T2 (C++ 4.4), respectively, and the 1730 // cv-qualification signature of type T1 is a proper subset of 1731 // the cv-qualification signature of type T2, and S1 is not the 1732 // deprecated string literal array-to-pointer conversion (4.2). 1733 if (SCS1.First != SCS2.First || SCS1.Second != SCS2.Second || 1734 SCS1.Third != SCS2.Third || SCS1.Third != ICK_Qualification) 1735 return ImplicitConversionSequence::Indistinguishable; 1736 1737 // FIXME: the example in the standard doesn't use a qualification 1738 // conversion (!) 1739 QualType T1 = QualType::getFromOpaquePtr(SCS1.ToTypePtr); 1740 QualType T2 = QualType::getFromOpaquePtr(SCS2.ToTypePtr); 1741 T1 = Context.getCanonicalType(T1); 1742 T2 = Context.getCanonicalType(T2); 1743 1744 // If the types are the same, we won't learn anything by unwrapped 1745 // them. 1746 if (T1.getUnqualifiedType() == T2.getUnqualifiedType()) 1747 return ImplicitConversionSequence::Indistinguishable; 1748 1749 ImplicitConversionSequence::CompareKind Result 1750 = ImplicitConversionSequence::Indistinguishable; 1751 while (UnwrapSimilarPointerTypes(T1, T2)) { 1752 // Within each iteration of the loop, we check the qualifiers to 1753 // determine if this still looks like a qualification 1754 // conversion. Then, if all is well, we unwrap one more level of 1755 // pointers or pointers-to-members and do it all again 1756 // until there are no more pointers or pointers-to-members left 1757 // to unwrap. This essentially mimics what 1758 // IsQualificationConversion does, but here we're checking for a 1759 // strict subset of qualifiers. 1760 if (T1.getCVRQualifiers() == T2.getCVRQualifiers()) 1761 // The qualifiers are the same, so this doesn't tell us anything 1762 // about how the sequences rank. 1763 ; 1764 else if (T2.isMoreQualifiedThan(T1)) { 1765 // T1 has fewer qualifiers, so it could be the better sequence. 1766 if (Result == ImplicitConversionSequence::Worse) 1767 // Neither has qualifiers that are a subset of the other's 1768 // qualifiers. 1769 return ImplicitConversionSequence::Indistinguishable; 1770 1771 Result = ImplicitConversionSequence::Better; 1772 } else if (T1.isMoreQualifiedThan(T2)) { 1773 // T2 has fewer qualifiers, so it could be the better sequence. 1774 if (Result == ImplicitConversionSequence::Better) 1775 // Neither has qualifiers that are a subset of the other's 1776 // qualifiers. 1777 return ImplicitConversionSequence::Indistinguishable; 1778 1779 Result = ImplicitConversionSequence::Worse; 1780 } else { 1781 // Qualifiers are disjoint. 1782 return ImplicitConversionSequence::Indistinguishable; 1783 } 1784 1785 // If the types after this point are equivalent, we're done. 1786 if (T1.getUnqualifiedType() == T2.getUnqualifiedType()) 1787 break; 1788 } 1789 1790 // Check that the winning standard conversion sequence isn't using 1791 // the deprecated string literal array to pointer conversion. 1792 switch (Result) { 1793 case ImplicitConversionSequence::Better: 1794 if (SCS1.Deprecated) 1795 Result = ImplicitConversionSequence::Indistinguishable; 1796 break; 1797 1798 case ImplicitConversionSequence::Indistinguishable: 1799 break; 1800 1801 case ImplicitConversionSequence::Worse: 1802 if (SCS2.Deprecated) 1803 Result = ImplicitConversionSequence::Indistinguishable; 1804 break; 1805 } 1806 1807 return Result; 1808} 1809 1810/// CompareDerivedToBaseConversions - Compares two standard conversion 1811/// sequences to determine whether they can be ranked based on their 1812/// various kinds of derived-to-base conversions (C++ 1813/// [over.ics.rank]p4b3). As part of these checks, we also look at 1814/// conversions between Objective-C interface types. 1815ImplicitConversionSequence::CompareKind 1816Sema::CompareDerivedToBaseConversions(const StandardConversionSequence& SCS1, 1817 const StandardConversionSequence& SCS2) { 1818 QualType FromType1 = QualType::getFromOpaquePtr(SCS1.FromTypePtr); 1819 QualType ToType1 = QualType::getFromOpaquePtr(SCS1.ToTypePtr); 1820 QualType FromType2 = QualType::getFromOpaquePtr(SCS2.FromTypePtr); 1821 QualType ToType2 = QualType::getFromOpaquePtr(SCS2.ToTypePtr); 1822 1823 // Adjust the types we're converting from via the array-to-pointer 1824 // conversion, if we need to. 1825 if (SCS1.First == ICK_Array_To_Pointer) 1826 FromType1 = Context.getArrayDecayedType(FromType1); 1827 if (SCS2.First == ICK_Array_To_Pointer) 1828 FromType2 = Context.getArrayDecayedType(FromType2); 1829 1830 // Canonicalize all of the types. 1831 FromType1 = Context.getCanonicalType(FromType1); 1832 ToType1 = Context.getCanonicalType(ToType1); 1833 FromType2 = Context.getCanonicalType(FromType2); 1834 ToType2 = Context.getCanonicalType(ToType2); 1835 1836 // C++ [over.ics.rank]p4b3: 1837 // 1838 // If class B is derived directly or indirectly from class A and 1839 // class C is derived directly or indirectly from B, 1840 // 1841 // For Objective-C, we let A, B, and C also be Objective-C 1842 // interfaces. 1843 1844 // Compare based on pointer conversions. 1845 if (SCS1.Second == ICK_Pointer_Conversion && 1846 SCS2.Second == ICK_Pointer_Conversion && 1847 /*FIXME: Remove if Objective-C id conversions get their own rank*/ 1848 FromType1->isPointerType() && FromType2->isPointerType() && 1849 ToType1->isPointerType() && ToType2->isPointerType()) { 1850 QualType FromPointee1 1851 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1852 QualType ToPointee1 1853 = ToType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1854 QualType FromPointee2 1855 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1856 QualType ToPointee2 1857 = ToType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1858 1859 const ObjCInterfaceType* FromIface1 = FromPointee1->getAs<ObjCInterfaceType>(); 1860 const ObjCInterfaceType* FromIface2 = FromPointee2->getAs<ObjCInterfaceType>(); 1861 const ObjCInterfaceType* ToIface1 = ToPointee1->getAs<ObjCInterfaceType>(); 1862 const ObjCInterfaceType* ToIface2 = ToPointee2->getAs<ObjCInterfaceType>(); 1863 1864 // -- conversion of C* to B* is better than conversion of C* to A*, 1865 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 1866 if (IsDerivedFrom(ToPointee1, ToPointee2)) 1867 return ImplicitConversionSequence::Better; 1868 else if (IsDerivedFrom(ToPointee2, ToPointee1)) 1869 return ImplicitConversionSequence::Worse; 1870 1871 if (ToIface1 && ToIface2) { 1872 if (Context.canAssignObjCInterfaces(ToIface2, ToIface1)) 1873 return ImplicitConversionSequence::Better; 1874 else if (Context.canAssignObjCInterfaces(ToIface1, ToIface2)) 1875 return ImplicitConversionSequence::Worse; 1876 } 1877 } 1878 1879 // -- conversion of B* to A* is better than conversion of C* to A*, 1880 if (FromPointee1 != FromPointee2 && ToPointee1 == ToPointee2) { 1881 if (IsDerivedFrom(FromPointee2, FromPointee1)) 1882 return ImplicitConversionSequence::Better; 1883 else if (IsDerivedFrom(FromPointee1, FromPointee2)) 1884 return ImplicitConversionSequence::Worse; 1885 1886 if (FromIface1 && FromIface2) { 1887 if (Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 1888 return ImplicitConversionSequence::Better; 1889 else if (Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 1890 return ImplicitConversionSequence::Worse; 1891 } 1892 } 1893 } 1894 1895 // Compare based on reference bindings. 1896 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding && 1897 SCS1.Second == ICK_Derived_To_Base) { 1898 // -- binding of an expression of type C to a reference of type 1899 // B& is better than binding an expression of type C to a 1900 // reference of type A&, 1901 if (FromType1.getUnqualifiedType() == FromType2.getUnqualifiedType() && 1902 ToType1.getUnqualifiedType() != ToType2.getUnqualifiedType()) { 1903 if (IsDerivedFrom(ToType1, ToType2)) 1904 return ImplicitConversionSequence::Better; 1905 else if (IsDerivedFrom(ToType2, ToType1)) 1906 return ImplicitConversionSequence::Worse; 1907 } 1908 1909 // -- binding of an expression of type B to a reference of type 1910 // A& is better than binding an expression of type C to a 1911 // reference of type A&, 1912 if (FromType1.getUnqualifiedType() != FromType2.getUnqualifiedType() && 1913 ToType1.getUnqualifiedType() == ToType2.getUnqualifiedType()) { 1914 if (IsDerivedFrom(FromType2, FromType1)) 1915 return ImplicitConversionSequence::Better; 1916 else if (IsDerivedFrom(FromType1, FromType2)) 1917 return ImplicitConversionSequence::Worse; 1918 } 1919 } 1920 1921 1922 // FIXME: conversion of A::* to B::* is better than conversion of 1923 // A::* to C::*, 1924 1925 // FIXME: conversion of B::* to C::* is better than conversion of 1926 // A::* to C::*, and 1927 1928 if (SCS1.CopyConstructor && SCS2.CopyConstructor && 1929 SCS1.Second == ICK_Derived_To_Base) { 1930 // -- conversion of C to B is better than conversion of C to A, 1931 if (FromType1.getUnqualifiedType() == FromType2.getUnqualifiedType() && 1932 ToType1.getUnqualifiedType() != ToType2.getUnqualifiedType()) { 1933 if (IsDerivedFrom(ToType1, ToType2)) 1934 return ImplicitConversionSequence::Better; 1935 else if (IsDerivedFrom(ToType2, ToType1)) 1936 return ImplicitConversionSequence::Worse; 1937 } 1938 1939 // -- conversion of B to A is better than conversion of C to A. 1940 if (FromType1.getUnqualifiedType() != FromType2.getUnqualifiedType() && 1941 ToType1.getUnqualifiedType() == ToType2.getUnqualifiedType()) { 1942 if (IsDerivedFrom(FromType2, FromType1)) 1943 return ImplicitConversionSequence::Better; 1944 else if (IsDerivedFrom(FromType1, FromType2)) 1945 return ImplicitConversionSequence::Worse; 1946 } 1947 } 1948 1949 return ImplicitConversionSequence::Indistinguishable; 1950} 1951 1952/// TryCopyInitialization - Try to copy-initialize a value of type 1953/// ToType from the expression From. Return the implicit conversion 1954/// sequence required to pass this argument, which may be a bad 1955/// conversion sequence (meaning that the argument cannot be passed to 1956/// a parameter of this type). If @p SuppressUserConversions, then we 1957/// do not permit any user-defined conversion sequences. If @p ForceRValue, 1958/// then we treat @p From as an rvalue, even if it is an lvalue. 1959ImplicitConversionSequence 1960Sema::TryCopyInitialization(Expr *From, QualType ToType, 1961 bool SuppressUserConversions, bool ForceRValue, 1962 bool InOverloadResolution) { 1963 if (ToType->isReferenceType()) { 1964 ImplicitConversionSequence ICS; 1965 CheckReferenceInit(From, ToType, 1966 /*FIXME:*/From->getLocStart(), 1967 SuppressUserConversions, 1968 /*AllowExplicit=*/false, 1969 ForceRValue, 1970 &ICS); 1971 return ICS; 1972 } else { 1973 return TryImplicitConversion(From, ToType, 1974 SuppressUserConversions, 1975 /*AllowExplicit=*/false, 1976 ForceRValue, 1977 InOverloadResolution); 1978 } 1979} 1980 1981/// PerformCopyInitialization - Copy-initialize an object of type @p ToType with 1982/// the expression @p From. Returns true (and emits a diagnostic) if there was 1983/// an error, returns false if the initialization succeeded. Elidable should 1984/// be true when the copy may be elided (C++ 12.8p15). Overload resolution works 1985/// differently in C++0x for this case. 1986bool Sema::PerformCopyInitialization(Expr *&From, QualType ToType, 1987 const char* Flavor, bool Elidable) { 1988 if (!getLangOptions().CPlusPlus) { 1989 // In C, argument passing is the same as performing an assignment. 1990 QualType FromType = From->getType(); 1991 1992 AssignConvertType ConvTy = 1993 CheckSingleAssignmentConstraints(ToType, From); 1994 if (ConvTy != Compatible && 1995 CheckTransparentUnionArgumentConstraints(ToType, From) == Compatible) 1996 ConvTy = Compatible; 1997 1998 return DiagnoseAssignmentResult(ConvTy, From->getLocStart(), ToType, 1999 FromType, From, Flavor); 2000 } 2001 2002 if (ToType->isReferenceType()) 2003 return CheckReferenceInit(From, ToType, 2004 /*FIXME:*/From->getLocStart(), 2005 /*SuppressUserConversions=*/false, 2006 /*AllowExplicit=*/false, 2007 /*ForceRValue=*/false); 2008 2009 if (!PerformImplicitConversion(From, ToType, Flavor, 2010 /*AllowExplicit=*/false, Elidable)) 2011 return false; 2012 if (!DiagnoseAmbiguousUserDefinedConversion(From, ToType)) 2013 return Diag(From->getSourceRange().getBegin(), 2014 diag::err_typecheck_convert_incompatible) 2015 << ToType << From->getType() << Flavor << From->getSourceRange(); 2016 return true; 2017} 2018 2019/// TryObjectArgumentInitialization - Try to initialize the object 2020/// parameter of the given member function (@c Method) from the 2021/// expression @p From. 2022ImplicitConversionSequence 2023Sema::TryObjectArgumentInitialization(Expr *From, CXXMethodDecl *Method) { 2024 QualType ClassType = Context.getTypeDeclType(Method->getParent()); 2025 unsigned MethodQuals = Method->getTypeQualifiers(); 2026 QualType ImplicitParamType = ClassType.getQualifiedType(MethodQuals); 2027 2028 // Set up the conversion sequence as a "bad" conversion, to allow us 2029 // to exit early. 2030 ImplicitConversionSequence ICS; 2031 ICS.Standard.setAsIdentityConversion(); 2032 ICS.ConversionKind = ImplicitConversionSequence::BadConversion; 2033 2034 // We need to have an object of class type. 2035 QualType FromType = From->getType(); 2036 if (const PointerType *PT = FromType->getAs<PointerType>()) 2037 FromType = PT->getPointeeType(); 2038 2039 assert(FromType->isRecordType()); 2040 2041 // The implicit object parmeter is has the type "reference to cv X", 2042 // where X is the class of which the function is a member 2043 // (C++ [over.match.funcs]p4). However, when finding an implicit 2044 // conversion sequence for the argument, we are not allowed to 2045 // create temporaries or perform user-defined conversions 2046 // (C++ [over.match.funcs]p5). We perform a simplified version of 2047 // reference binding here, that allows class rvalues to bind to 2048 // non-constant references. 2049 2050 // First check the qualifiers. We don't care about lvalue-vs-rvalue 2051 // with the implicit object parameter (C++ [over.match.funcs]p5). 2052 QualType FromTypeCanon = Context.getCanonicalType(FromType); 2053 if (ImplicitParamType.getCVRQualifiers() != FromType.getCVRQualifiers() && 2054 !ImplicitParamType.isAtLeastAsQualifiedAs(FromType)) 2055 return ICS; 2056 2057 // Check that we have either the same type or a derived type. It 2058 // affects the conversion rank. 2059 QualType ClassTypeCanon = Context.getCanonicalType(ClassType); 2060 if (ClassTypeCanon == FromTypeCanon.getUnqualifiedType()) 2061 ICS.Standard.Second = ICK_Identity; 2062 else if (IsDerivedFrom(FromType, ClassType)) 2063 ICS.Standard.Second = ICK_Derived_To_Base; 2064 else 2065 return ICS; 2066 2067 // Success. Mark this as a reference binding. 2068 ICS.ConversionKind = ImplicitConversionSequence::StandardConversion; 2069 ICS.Standard.FromTypePtr = FromType.getAsOpaquePtr(); 2070 ICS.Standard.ToTypePtr = ImplicitParamType.getAsOpaquePtr(); 2071 ICS.Standard.ReferenceBinding = true; 2072 ICS.Standard.DirectBinding = true; 2073 ICS.Standard.RRefBinding = false; 2074 return ICS; 2075} 2076 2077/// PerformObjectArgumentInitialization - Perform initialization of 2078/// the implicit object parameter for the given Method with the given 2079/// expression. 2080bool 2081Sema::PerformObjectArgumentInitialization(Expr *&From, CXXMethodDecl *Method) { 2082 QualType FromRecordType, DestType; 2083 QualType ImplicitParamRecordType = 2084 Method->getThisType(Context)->getAs<PointerType>()->getPointeeType(); 2085 2086 if (const PointerType *PT = From->getType()->getAs<PointerType>()) { 2087 FromRecordType = PT->getPointeeType(); 2088 DestType = Method->getThisType(Context); 2089 } else { 2090 FromRecordType = From->getType(); 2091 DestType = ImplicitParamRecordType; 2092 } 2093 2094 ImplicitConversionSequence ICS 2095 = TryObjectArgumentInitialization(From, Method); 2096 if (ICS.ConversionKind == ImplicitConversionSequence::BadConversion) 2097 return Diag(From->getSourceRange().getBegin(), 2098 diag::err_implicit_object_parameter_init) 2099 << ImplicitParamRecordType << FromRecordType << From->getSourceRange(); 2100 2101 if (ICS.Standard.Second == ICK_Derived_To_Base && 2102 CheckDerivedToBaseConversion(FromRecordType, 2103 ImplicitParamRecordType, 2104 From->getSourceRange().getBegin(), 2105 From->getSourceRange())) 2106 return true; 2107 2108 ImpCastExprToType(From, DestType, CastExpr::CK_DerivedToBase, 2109 /*isLvalue=*/true); 2110 return false; 2111} 2112 2113/// TryContextuallyConvertToBool - Attempt to contextually convert the 2114/// expression From to bool (C++0x [conv]p3). 2115ImplicitConversionSequence Sema::TryContextuallyConvertToBool(Expr *From) { 2116 return TryImplicitConversion(From, Context.BoolTy, 2117 // FIXME: Are these flags correct? 2118 /*SuppressUserConversions=*/false, 2119 /*AllowExplicit=*/true, 2120 /*ForceRValue=*/false, 2121 /*InOverloadResolution=*/false); 2122} 2123 2124/// PerformContextuallyConvertToBool - Perform a contextual conversion 2125/// of the expression From to bool (C++0x [conv]p3). 2126bool Sema::PerformContextuallyConvertToBool(Expr *&From) { 2127 ImplicitConversionSequence ICS = TryContextuallyConvertToBool(From); 2128 if (!PerformImplicitConversion(From, Context.BoolTy, ICS, "converting")) 2129 return false; 2130 2131 if (!DiagnoseAmbiguousUserDefinedConversion(From, Context.BoolTy)) 2132 return Diag(From->getSourceRange().getBegin(), 2133 diag::err_typecheck_bool_condition) 2134 << From->getType() << From->getSourceRange(); 2135 return true; 2136} 2137 2138/// AddOverloadCandidate - Adds the given function to the set of 2139/// candidate functions, using the given function call arguments. If 2140/// @p SuppressUserConversions, then don't allow user-defined 2141/// conversions via constructors or conversion operators. 2142/// If @p ForceRValue, treat all arguments as rvalues. This is a slightly 2143/// hacky way to implement the overloading rules for elidable copy 2144/// initialization in C++0x (C++0x 12.8p15). 2145/// 2146/// \para PartialOverloading true if we are performing "partial" overloading 2147/// based on an incomplete set of function arguments. This feature is used by 2148/// code completion. 2149void 2150Sema::AddOverloadCandidate(FunctionDecl *Function, 2151 Expr **Args, unsigned NumArgs, 2152 OverloadCandidateSet& CandidateSet, 2153 bool SuppressUserConversions, 2154 bool ForceRValue, 2155 bool PartialOverloading) { 2156 const FunctionProtoType* Proto 2157 = dyn_cast<FunctionProtoType>(Function->getType()->getAs<FunctionType>()); 2158 assert(Proto && "Functions without a prototype cannot be overloaded"); 2159 assert(!isa<CXXConversionDecl>(Function) && 2160 "Use AddConversionCandidate for conversion functions"); 2161 assert(!Function->getDescribedFunctionTemplate() && 2162 "Use AddTemplateOverloadCandidate for function templates"); 2163 2164 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Function)) { 2165 if (!isa<CXXConstructorDecl>(Method)) { 2166 // If we get here, it's because we're calling a member function 2167 // that is named without a member access expression (e.g., 2168 // "this->f") that was either written explicitly or created 2169 // implicitly. This can happen with a qualified call to a member 2170 // function, e.g., X::f(). We use a NULL object as the implied 2171 // object argument (C++ [over.call.func]p3). 2172 AddMethodCandidate(Method, 0, Args, NumArgs, CandidateSet, 2173 SuppressUserConversions, ForceRValue); 2174 return; 2175 } 2176 // We treat a constructor like a non-member function, since its object 2177 // argument doesn't participate in overload resolution. 2178 } 2179 2180 2181 // Add this candidate 2182 CandidateSet.push_back(OverloadCandidate()); 2183 OverloadCandidate& Candidate = CandidateSet.back(); 2184 Candidate.Function = Function; 2185 Candidate.Viable = true; 2186 Candidate.IsSurrogate = false; 2187 Candidate.IgnoreObjectArgument = false; 2188 2189 unsigned NumArgsInProto = Proto->getNumArgs(); 2190 2191 // (C++ 13.3.2p2): A candidate function having fewer than m 2192 // parameters is viable only if it has an ellipsis in its parameter 2193 // list (8.3.5). 2194 if ((NumArgs + (PartialOverloading && NumArgs)) > NumArgsInProto && 2195 !Proto->isVariadic()) { 2196 Candidate.Viable = false; 2197 return; 2198 } 2199 2200 // (C++ 13.3.2p2): A candidate function having more than m parameters 2201 // is viable only if the (m+1)st parameter has a default argument 2202 // (8.3.6). For the purposes of overload resolution, the 2203 // parameter list is truncated on the right, so that there are 2204 // exactly m parameters. 2205 unsigned MinRequiredArgs = Function->getMinRequiredArguments(); 2206 if (NumArgs < MinRequiredArgs && !PartialOverloading) { 2207 // Not enough arguments. 2208 Candidate.Viable = false; 2209 return; 2210 } 2211 2212 // Determine the implicit conversion sequences for each of the 2213 // arguments. 2214 Candidate.Conversions.resize(NumArgs); 2215 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2216 if (ArgIdx < NumArgsInProto) { 2217 // (C++ 13.3.2p3): for F to be a viable function, there shall 2218 // exist for each argument an implicit conversion sequence 2219 // (13.3.3.1) that converts that argument to the corresponding 2220 // parameter of F. 2221 QualType ParamType = Proto->getArgType(ArgIdx); 2222 Candidate.Conversions[ArgIdx] 2223 = TryCopyInitialization(Args[ArgIdx], ParamType, 2224 SuppressUserConversions, ForceRValue, 2225 /*InOverloadResolution=*/true); 2226 if (Candidate.Conversions[ArgIdx].ConversionKind 2227 == ImplicitConversionSequence::BadConversion) { 2228 Candidate.Viable = false; 2229 break; 2230 } 2231 } else { 2232 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2233 // argument for which there is no corresponding parameter is 2234 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2235 Candidate.Conversions[ArgIdx].ConversionKind 2236 = ImplicitConversionSequence::EllipsisConversion; 2237 } 2238 } 2239} 2240 2241/// \brief Add all of the function declarations in the given function set to 2242/// the overload canddiate set. 2243void Sema::AddFunctionCandidates(const FunctionSet &Functions, 2244 Expr **Args, unsigned NumArgs, 2245 OverloadCandidateSet& CandidateSet, 2246 bool SuppressUserConversions) { 2247 for (FunctionSet::const_iterator F = Functions.begin(), 2248 FEnd = Functions.end(); 2249 F != FEnd; ++F) { 2250 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*F)) 2251 AddOverloadCandidate(FD, Args, NumArgs, CandidateSet, 2252 SuppressUserConversions); 2253 else 2254 AddTemplateOverloadCandidate(cast<FunctionTemplateDecl>(*F), 2255 /*FIXME: explicit args */false, 0, 0, 2256 Args, NumArgs, CandidateSet, 2257 SuppressUserConversions); 2258 } 2259} 2260 2261/// AddMethodCandidate - Adds the given C++ member function to the set 2262/// of candidate functions, using the given function call arguments 2263/// and the object argument (@c Object). For example, in a call 2264/// @c o.f(a1,a2), @c Object will contain @c o and @c Args will contain 2265/// both @c a1 and @c a2. If @p SuppressUserConversions, then don't 2266/// allow user-defined conversions via constructors or conversion 2267/// operators. If @p ForceRValue, treat all arguments as rvalues. This is 2268/// a slightly hacky way to implement the overloading rules for elidable copy 2269/// initialization in C++0x (C++0x 12.8p15). 2270void 2271Sema::AddMethodCandidate(CXXMethodDecl *Method, Expr *Object, 2272 Expr **Args, unsigned NumArgs, 2273 OverloadCandidateSet& CandidateSet, 2274 bool SuppressUserConversions, bool ForceRValue) { 2275 const FunctionProtoType* Proto 2276 = dyn_cast<FunctionProtoType>(Method->getType()->getAs<FunctionType>()); 2277 assert(Proto && "Methods without a prototype cannot be overloaded"); 2278 assert(!isa<CXXConversionDecl>(Method) && 2279 "Use AddConversionCandidate for conversion functions"); 2280 assert(!isa<CXXConstructorDecl>(Method) && 2281 "Use AddOverloadCandidate for constructors"); 2282 2283 // Add this candidate 2284 CandidateSet.push_back(OverloadCandidate()); 2285 OverloadCandidate& Candidate = CandidateSet.back(); 2286 Candidate.Function = Method; 2287 Candidate.IsSurrogate = false; 2288 Candidate.IgnoreObjectArgument = false; 2289 2290 unsigned NumArgsInProto = Proto->getNumArgs(); 2291 2292 // (C++ 13.3.2p2): A candidate function having fewer than m 2293 // parameters is viable only if it has an ellipsis in its parameter 2294 // list (8.3.5). 2295 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 2296 Candidate.Viable = false; 2297 return; 2298 } 2299 2300 // (C++ 13.3.2p2): A candidate function having more than m parameters 2301 // is viable only if the (m+1)st parameter has a default argument 2302 // (8.3.6). For the purposes of overload resolution, the 2303 // parameter list is truncated on the right, so that there are 2304 // exactly m parameters. 2305 unsigned MinRequiredArgs = Method->getMinRequiredArguments(); 2306 if (NumArgs < MinRequiredArgs) { 2307 // Not enough arguments. 2308 Candidate.Viable = false; 2309 return; 2310 } 2311 2312 Candidate.Viable = true; 2313 Candidate.Conversions.resize(NumArgs + 1); 2314 2315 if (Method->isStatic() || !Object) 2316 // The implicit object argument is ignored. 2317 Candidate.IgnoreObjectArgument = true; 2318 else { 2319 // Determine the implicit conversion sequence for the object 2320 // parameter. 2321 Candidate.Conversions[0] = TryObjectArgumentInitialization(Object, Method); 2322 if (Candidate.Conversions[0].ConversionKind 2323 == ImplicitConversionSequence::BadConversion) { 2324 Candidate.Viable = false; 2325 return; 2326 } 2327 } 2328 2329 // Determine the implicit conversion sequences for each of the 2330 // arguments. 2331 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2332 if (ArgIdx < NumArgsInProto) { 2333 // (C++ 13.3.2p3): for F to be a viable function, there shall 2334 // exist for each argument an implicit conversion sequence 2335 // (13.3.3.1) that converts that argument to the corresponding 2336 // parameter of F. 2337 QualType ParamType = Proto->getArgType(ArgIdx); 2338 Candidate.Conversions[ArgIdx + 1] 2339 = TryCopyInitialization(Args[ArgIdx], ParamType, 2340 SuppressUserConversions, ForceRValue, 2341 /*InOverloadResolution=*/true); 2342 if (Candidate.Conversions[ArgIdx + 1].ConversionKind 2343 == ImplicitConversionSequence::BadConversion) { 2344 Candidate.Viable = false; 2345 break; 2346 } 2347 } else { 2348 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2349 // argument for which there is no corresponding parameter is 2350 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2351 Candidate.Conversions[ArgIdx + 1].ConversionKind 2352 = ImplicitConversionSequence::EllipsisConversion; 2353 } 2354 } 2355} 2356 2357/// \brief Add a C++ member function template as a candidate to the candidate 2358/// set, using template argument deduction to produce an appropriate member 2359/// function template specialization. 2360void 2361Sema::AddMethodTemplateCandidate(FunctionTemplateDecl *MethodTmpl, 2362 bool HasExplicitTemplateArgs, 2363 const TemplateArgument *ExplicitTemplateArgs, 2364 unsigned NumExplicitTemplateArgs, 2365 Expr *Object, Expr **Args, unsigned NumArgs, 2366 OverloadCandidateSet& CandidateSet, 2367 bool SuppressUserConversions, 2368 bool ForceRValue) { 2369 // C++ [over.match.funcs]p7: 2370 // In each case where a candidate is a function template, candidate 2371 // function template specializations are generated using template argument 2372 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 2373 // candidate functions in the usual way.113) A given name can refer to one 2374 // or more function templates and also to a set of overloaded non-template 2375 // functions. In such a case, the candidate functions generated from each 2376 // function template are combined with the set of non-template candidate 2377 // functions. 2378 TemplateDeductionInfo Info(Context); 2379 FunctionDecl *Specialization = 0; 2380 if (TemplateDeductionResult Result 2381 = DeduceTemplateArguments(MethodTmpl, HasExplicitTemplateArgs, 2382 ExplicitTemplateArgs, NumExplicitTemplateArgs, 2383 Args, NumArgs, Specialization, Info)) { 2384 // FIXME: Record what happened with template argument deduction, so 2385 // that we can give the user a beautiful diagnostic. 2386 (void)Result; 2387 return; 2388 } 2389 2390 // Add the function template specialization produced by template argument 2391 // deduction as a candidate. 2392 assert(Specialization && "Missing member function template specialization?"); 2393 assert(isa<CXXMethodDecl>(Specialization) && 2394 "Specialization is not a member function?"); 2395 AddMethodCandidate(cast<CXXMethodDecl>(Specialization), Object, Args, NumArgs, 2396 CandidateSet, SuppressUserConversions, ForceRValue); 2397} 2398 2399/// \brief Add a C++ function template specialization as a candidate 2400/// in the candidate set, using template argument deduction to produce 2401/// an appropriate function template specialization. 2402void 2403Sema::AddTemplateOverloadCandidate(FunctionTemplateDecl *FunctionTemplate, 2404 bool HasExplicitTemplateArgs, 2405 const TemplateArgument *ExplicitTemplateArgs, 2406 unsigned NumExplicitTemplateArgs, 2407 Expr **Args, unsigned NumArgs, 2408 OverloadCandidateSet& CandidateSet, 2409 bool SuppressUserConversions, 2410 bool ForceRValue) { 2411 // C++ [over.match.funcs]p7: 2412 // In each case where a candidate is a function template, candidate 2413 // function template specializations are generated using template argument 2414 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 2415 // candidate functions in the usual way.113) A given name can refer to one 2416 // or more function templates and also to a set of overloaded non-template 2417 // functions. In such a case, the candidate functions generated from each 2418 // function template are combined with the set of non-template candidate 2419 // functions. 2420 TemplateDeductionInfo Info(Context); 2421 FunctionDecl *Specialization = 0; 2422 if (TemplateDeductionResult Result 2423 = DeduceTemplateArguments(FunctionTemplate, HasExplicitTemplateArgs, 2424 ExplicitTemplateArgs, NumExplicitTemplateArgs, 2425 Args, NumArgs, Specialization, Info)) { 2426 // FIXME: Record what happened with template argument deduction, so 2427 // that we can give the user a beautiful diagnostic. 2428 (void)Result; 2429 return; 2430 } 2431 2432 // Add the function template specialization produced by template argument 2433 // deduction as a candidate. 2434 assert(Specialization && "Missing function template specialization?"); 2435 AddOverloadCandidate(Specialization, Args, NumArgs, CandidateSet, 2436 SuppressUserConversions, ForceRValue); 2437} 2438 2439/// AddConversionCandidate - Add a C++ conversion function as a 2440/// candidate in the candidate set (C++ [over.match.conv], 2441/// C++ [over.match.copy]). From is the expression we're converting from, 2442/// and ToType is the type that we're eventually trying to convert to 2443/// (which may or may not be the same type as the type that the 2444/// conversion function produces). 2445void 2446Sema::AddConversionCandidate(CXXConversionDecl *Conversion, 2447 Expr *From, QualType ToType, 2448 OverloadCandidateSet& CandidateSet) { 2449 assert(!Conversion->getDescribedFunctionTemplate() && 2450 "Conversion function templates use AddTemplateConversionCandidate"); 2451 2452 // Add this candidate 2453 CandidateSet.push_back(OverloadCandidate()); 2454 OverloadCandidate& Candidate = CandidateSet.back(); 2455 Candidate.Function = Conversion; 2456 Candidate.IsSurrogate = false; 2457 Candidate.IgnoreObjectArgument = false; 2458 Candidate.FinalConversion.setAsIdentityConversion(); 2459 Candidate.FinalConversion.FromTypePtr 2460 = Conversion->getConversionType().getAsOpaquePtr(); 2461 Candidate.FinalConversion.ToTypePtr = ToType.getAsOpaquePtr(); 2462 2463 // Determine the implicit conversion sequence for the implicit 2464 // object parameter. 2465 Candidate.Viable = true; 2466 Candidate.Conversions.resize(1); 2467 Candidate.Conversions[0] = TryObjectArgumentInitialization(From, Conversion); 2468 // Conversion functions to a different type in the base class is visible in 2469 // the derived class. So, a derived to base conversion should not participate 2470 // in overload resolution. 2471 if (Candidate.Conversions[0].Standard.Second == ICK_Derived_To_Base) 2472 Candidate.Conversions[0].Standard.Second = ICK_Identity; 2473 if (Candidate.Conversions[0].ConversionKind 2474 == ImplicitConversionSequence::BadConversion) { 2475 Candidate.Viable = false; 2476 return; 2477 } 2478 2479 // To determine what the conversion from the result of calling the 2480 // conversion function to the type we're eventually trying to 2481 // convert to (ToType), we need to synthesize a call to the 2482 // conversion function and attempt copy initialization from it. This 2483 // makes sure that we get the right semantics with respect to 2484 // lvalues/rvalues and the type. Fortunately, we can allocate this 2485 // call on the stack and we don't need its arguments to be 2486 // well-formed. 2487 DeclRefExpr ConversionRef(Conversion, Conversion->getType(), 2488 SourceLocation()); 2489 ImplicitCastExpr ConversionFn(Context.getPointerType(Conversion->getType()), 2490 CastExpr::CK_Unknown, 2491 &ConversionRef, false); 2492 2493 // Note that it is safe to allocate CallExpr on the stack here because 2494 // there are 0 arguments (i.e., nothing is allocated using ASTContext's 2495 // allocator). 2496 CallExpr Call(Context, &ConversionFn, 0, 0, 2497 Conversion->getConversionType().getNonReferenceType(), 2498 SourceLocation()); 2499 ImplicitConversionSequence ICS = 2500 TryCopyInitialization(&Call, ToType, 2501 /*SuppressUserConversions=*/true, 2502 /*ForceRValue=*/false, 2503 /*InOverloadResolution=*/false); 2504 2505 switch (ICS.ConversionKind) { 2506 case ImplicitConversionSequence::StandardConversion: 2507 Candidate.FinalConversion = ICS.Standard; 2508 break; 2509 2510 case ImplicitConversionSequence::BadConversion: 2511 Candidate.Viable = false; 2512 break; 2513 2514 default: 2515 assert(false && 2516 "Can only end up with a standard conversion sequence or failure"); 2517 } 2518} 2519 2520/// \brief Adds a conversion function template specialization 2521/// candidate to the overload set, using template argument deduction 2522/// to deduce the template arguments of the conversion function 2523/// template from the type that we are converting to (C++ 2524/// [temp.deduct.conv]). 2525void 2526Sema::AddTemplateConversionCandidate(FunctionTemplateDecl *FunctionTemplate, 2527 Expr *From, QualType ToType, 2528 OverloadCandidateSet &CandidateSet) { 2529 assert(isa<CXXConversionDecl>(FunctionTemplate->getTemplatedDecl()) && 2530 "Only conversion function templates permitted here"); 2531 2532 TemplateDeductionInfo Info(Context); 2533 CXXConversionDecl *Specialization = 0; 2534 if (TemplateDeductionResult Result 2535 = DeduceTemplateArguments(FunctionTemplate, ToType, 2536 Specialization, Info)) { 2537 // FIXME: Record what happened with template argument deduction, so 2538 // that we can give the user a beautiful diagnostic. 2539 (void)Result; 2540 return; 2541 } 2542 2543 // Add the conversion function template specialization produced by 2544 // template argument deduction as a candidate. 2545 assert(Specialization && "Missing function template specialization?"); 2546 AddConversionCandidate(Specialization, From, ToType, CandidateSet); 2547} 2548 2549/// AddSurrogateCandidate - Adds a "surrogate" candidate function that 2550/// converts the given @c Object to a function pointer via the 2551/// conversion function @c Conversion, and then attempts to call it 2552/// with the given arguments (C++ [over.call.object]p2-4). Proto is 2553/// the type of function that we'll eventually be calling. 2554void Sema::AddSurrogateCandidate(CXXConversionDecl *Conversion, 2555 const FunctionProtoType *Proto, 2556 Expr *Object, Expr **Args, unsigned NumArgs, 2557 OverloadCandidateSet& CandidateSet) { 2558 CandidateSet.push_back(OverloadCandidate()); 2559 OverloadCandidate& Candidate = CandidateSet.back(); 2560 Candidate.Function = 0; 2561 Candidate.Surrogate = Conversion; 2562 Candidate.Viable = true; 2563 Candidate.IsSurrogate = true; 2564 Candidate.IgnoreObjectArgument = false; 2565 Candidate.Conversions.resize(NumArgs + 1); 2566 2567 // Determine the implicit conversion sequence for the implicit 2568 // object parameter. 2569 ImplicitConversionSequence ObjectInit 2570 = TryObjectArgumentInitialization(Object, Conversion); 2571 if (ObjectInit.ConversionKind == ImplicitConversionSequence::BadConversion) { 2572 Candidate.Viable = false; 2573 return; 2574 } 2575 2576 // The first conversion is actually a user-defined conversion whose 2577 // first conversion is ObjectInit's standard conversion (which is 2578 // effectively a reference binding). Record it as such. 2579 Candidate.Conversions[0].ConversionKind 2580 = ImplicitConversionSequence::UserDefinedConversion; 2581 Candidate.Conversions[0].UserDefined.Before = ObjectInit.Standard; 2582 Candidate.Conversions[0].UserDefined.ConversionFunction = Conversion; 2583 Candidate.Conversions[0].UserDefined.After 2584 = Candidate.Conversions[0].UserDefined.Before; 2585 Candidate.Conversions[0].UserDefined.After.setAsIdentityConversion(); 2586 2587 // Find the 2588 unsigned NumArgsInProto = Proto->getNumArgs(); 2589 2590 // (C++ 13.3.2p2): A candidate function having fewer than m 2591 // parameters is viable only if it has an ellipsis in its parameter 2592 // list (8.3.5). 2593 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 2594 Candidate.Viable = false; 2595 return; 2596 } 2597 2598 // Function types don't have any default arguments, so just check if 2599 // we have enough arguments. 2600 if (NumArgs < NumArgsInProto) { 2601 // Not enough arguments. 2602 Candidate.Viable = false; 2603 return; 2604 } 2605 2606 // Determine the implicit conversion sequences for each of the 2607 // arguments. 2608 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2609 if (ArgIdx < NumArgsInProto) { 2610 // (C++ 13.3.2p3): for F to be a viable function, there shall 2611 // exist for each argument an implicit conversion sequence 2612 // (13.3.3.1) that converts that argument to the corresponding 2613 // parameter of F. 2614 QualType ParamType = Proto->getArgType(ArgIdx); 2615 Candidate.Conversions[ArgIdx + 1] 2616 = TryCopyInitialization(Args[ArgIdx], ParamType, 2617 /*SuppressUserConversions=*/false, 2618 /*ForceRValue=*/false, 2619 /*InOverloadResolution=*/false); 2620 if (Candidate.Conversions[ArgIdx + 1].ConversionKind 2621 == ImplicitConversionSequence::BadConversion) { 2622 Candidate.Viable = false; 2623 break; 2624 } 2625 } else { 2626 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2627 // argument for which there is no corresponding parameter is 2628 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2629 Candidate.Conversions[ArgIdx + 1].ConversionKind 2630 = ImplicitConversionSequence::EllipsisConversion; 2631 } 2632 } 2633} 2634 2635// FIXME: This will eventually be removed, once we've migrated all of the 2636// operator overloading logic over to the scheme used by binary operators, which 2637// works for template instantiation. 2638void Sema::AddOperatorCandidates(OverloadedOperatorKind Op, Scope *S, 2639 SourceLocation OpLoc, 2640 Expr **Args, unsigned NumArgs, 2641 OverloadCandidateSet& CandidateSet, 2642 SourceRange OpRange) { 2643 2644 FunctionSet Functions; 2645 2646 QualType T1 = Args[0]->getType(); 2647 QualType T2; 2648 if (NumArgs > 1) 2649 T2 = Args[1]->getType(); 2650 2651 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 2652 if (S) 2653 LookupOverloadedOperatorName(Op, S, T1, T2, Functions); 2654 ArgumentDependentLookup(OpName, Args, NumArgs, Functions); 2655 AddFunctionCandidates(Functions, Args, NumArgs, CandidateSet); 2656 AddMemberOperatorCandidates(Op, OpLoc, Args, NumArgs, CandidateSet, OpRange); 2657 AddBuiltinOperatorCandidates(Op, Args, NumArgs, CandidateSet); 2658} 2659 2660/// \brief Add overload candidates for overloaded operators that are 2661/// member functions. 2662/// 2663/// Add the overloaded operator candidates that are member functions 2664/// for the operator Op that was used in an operator expression such 2665/// as "x Op y". , Args/NumArgs provides the operator arguments, and 2666/// CandidateSet will store the added overload candidates. (C++ 2667/// [over.match.oper]). 2668void Sema::AddMemberOperatorCandidates(OverloadedOperatorKind Op, 2669 SourceLocation OpLoc, 2670 Expr **Args, unsigned NumArgs, 2671 OverloadCandidateSet& CandidateSet, 2672 SourceRange OpRange) { 2673 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 2674 2675 // C++ [over.match.oper]p3: 2676 // For a unary operator @ with an operand of a type whose 2677 // cv-unqualified version is T1, and for a binary operator @ with 2678 // a left operand of a type whose cv-unqualified version is T1 and 2679 // a right operand of a type whose cv-unqualified version is T2, 2680 // three sets of candidate functions, designated member 2681 // candidates, non-member candidates and built-in candidates, are 2682 // constructed as follows: 2683 QualType T1 = Args[0]->getType(); 2684 QualType T2; 2685 if (NumArgs > 1) 2686 T2 = Args[1]->getType(); 2687 2688 // -- If T1 is a class type, the set of member candidates is the 2689 // result of the qualified lookup of T1::operator@ 2690 // (13.3.1.1.1); otherwise, the set of member candidates is 2691 // empty. 2692 if (const RecordType *T1Rec = T1->getAs<RecordType>()) { 2693 // Complete the type if it can be completed. Otherwise, we're done. 2694 if (RequireCompleteType(OpLoc, T1, PartialDiagnostic(0))) 2695 return; 2696 2697 LookupResult Operators = LookupQualifiedName(T1Rec->getDecl(), OpName, 2698 LookupOrdinaryName, false); 2699 for (LookupResult::iterator Oper = Operators.begin(), 2700 OperEnd = Operators.end(); 2701 Oper != OperEnd; 2702 ++Oper) 2703 AddMethodCandidate(cast<CXXMethodDecl>(*Oper), Args[0], 2704 Args+1, NumArgs - 1, CandidateSet, 2705 /*SuppressUserConversions=*/false); 2706 } 2707} 2708 2709/// AddBuiltinCandidate - Add a candidate for a built-in 2710/// operator. ResultTy and ParamTys are the result and parameter types 2711/// of the built-in candidate, respectively. Args and NumArgs are the 2712/// arguments being passed to the candidate. IsAssignmentOperator 2713/// should be true when this built-in candidate is an assignment 2714/// operator. NumContextualBoolArguments is the number of arguments 2715/// (at the beginning of the argument list) that will be contextually 2716/// converted to bool. 2717void Sema::AddBuiltinCandidate(QualType ResultTy, QualType *ParamTys, 2718 Expr **Args, unsigned NumArgs, 2719 OverloadCandidateSet& CandidateSet, 2720 bool IsAssignmentOperator, 2721 unsigned NumContextualBoolArguments) { 2722 // Add this candidate 2723 CandidateSet.push_back(OverloadCandidate()); 2724 OverloadCandidate& Candidate = CandidateSet.back(); 2725 Candidate.Function = 0; 2726 Candidate.IsSurrogate = false; 2727 Candidate.IgnoreObjectArgument = false; 2728 Candidate.BuiltinTypes.ResultTy = ResultTy; 2729 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 2730 Candidate.BuiltinTypes.ParamTypes[ArgIdx] = ParamTys[ArgIdx]; 2731 2732 // Determine the implicit conversion sequences for each of the 2733 // arguments. 2734 Candidate.Viable = true; 2735 Candidate.Conversions.resize(NumArgs); 2736 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2737 // C++ [over.match.oper]p4: 2738 // For the built-in assignment operators, conversions of the 2739 // left operand are restricted as follows: 2740 // -- no temporaries are introduced to hold the left operand, and 2741 // -- no user-defined conversions are applied to the left 2742 // operand to achieve a type match with the left-most 2743 // parameter of a built-in candidate. 2744 // 2745 // We block these conversions by turning off user-defined 2746 // conversions, since that is the only way that initialization of 2747 // a reference to a non-class type can occur from something that 2748 // is not of the same type. 2749 if (ArgIdx < NumContextualBoolArguments) { 2750 assert(ParamTys[ArgIdx] == Context.BoolTy && 2751 "Contextual conversion to bool requires bool type"); 2752 Candidate.Conversions[ArgIdx] = TryContextuallyConvertToBool(Args[ArgIdx]); 2753 } else { 2754 Candidate.Conversions[ArgIdx] 2755 = TryCopyInitialization(Args[ArgIdx], ParamTys[ArgIdx], 2756 ArgIdx == 0 && IsAssignmentOperator, 2757 /*ForceRValue=*/false, 2758 /*InOverloadResolution=*/false); 2759 } 2760 if (Candidate.Conversions[ArgIdx].ConversionKind 2761 == ImplicitConversionSequence::BadConversion) { 2762 Candidate.Viable = false; 2763 break; 2764 } 2765 } 2766} 2767 2768/// BuiltinCandidateTypeSet - A set of types that will be used for the 2769/// candidate operator functions for built-in operators (C++ 2770/// [over.built]). The types are separated into pointer types and 2771/// enumeration types. 2772class BuiltinCandidateTypeSet { 2773 /// TypeSet - A set of types. 2774 typedef llvm::SmallPtrSet<QualType, 8> TypeSet; 2775 2776 /// PointerTypes - The set of pointer types that will be used in the 2777 /// built-in candidates. 2778 TypeSet PointerTypes; 2779 2780 /// MemberPointerTypes - The set of member pointer types that will be 2781 /// used in the built-in candidates. 2782 TypeSet MemberPointerTypes; 2783 2784 /// EnumerationTypes - The set of enumeration types that will be 2785 /// used in the built-in candidates. 2786 TypeSet EnumerationTypes; 2787 2788 /// Sema - The semantic analysis instance where we are building the 2789 /// candidate type set. 2790 Sema &SemaRef; 2791 2792 /// Context - The AST context in which we will build the type sets. 2793 ASTContext &Context; 2794 2795 bool AddPointerWithMoreQualifiedTypeVariants(QualType Ty); 2796 bool AddMemberPointerWithMoreQualifiedTypeVariants(QualType Ty); 2797 2798public: 2799 /// iterator - Iterates through the types that are part of the set. 2800 typedef TypeSet::iterator iterator; 2801 2802 BuiltinCandidateTypeSet(Sema &SemaRef) 2803 : SemaRef(SemaRef), Context(SemaRef.Context) { } 2804 2805 void AddTypesConvertedFrom(QualType Ty, bool AllowUserConversions, 2806 bool AllowExplicitConversions); 2807 2808 /// pointer_begin - First pointer type found; 2809 iterator pointer_begin() { return PointerTypes.begin(); } 2810 2811 /// pointer_end - Past the last pointer type found; 2812 iterator pointer_end() { return PointerTypes.end(); } 2813 2814 /// member_pointer_begin - First member pointer type found; 2815 iterator member_pointer_begin() { return MemberPointerTypes.begin(); } 2816 2817 /// member_pointer_end - Past the last member pointer type found; 2818 iterator member_pointer_end() { return MemberPointerTypes.end(); } 2819 2820 /// enumeration_begin - First enumeration type found; 2821 iterator enumeration_begin() { return EnumerationTypes.begin(); } 2822 2823 /// enumeration_end - Past the last enumeration type found; 2824 iterator enumeration_end() { return EnumerationTypes.end(); } 2825}; 2826 2827/// AddPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty to 2828/// the set of pointer types along with any more-qualified variants of 2829/// that type. For example, if @p Ty is "int const *", this routine 2830/// will add "int const *", "int const volatile *", "int const 2831/// restrict *", and "int const volatile restrict *" to the set of 2832/// pointer types. Returns true if the add of @p Ty itself succeeded, 2833/// false otherwise. 2834bool 2835BuiltinCandidateTypeSet::AddPointerWithMoreQualifiedTypeVariants(QualType Ty) { 2836 // Insert this type. 2837 if (!PointerTypes.insert(Ty)) 2838 return false; 2839 2840 if (const PointerType *PointerTy = Ty->getAs<PointerType>()) { 2841 QualType PointeeTy = PointerTy->getPointeeType(); 2842 // FIXME: Optimize this so that we don't keep trying to add the same types. 2843 2844 // FIXME: Do we have to add CVR qualifiers at *all* levels to deal with all 2845 // pointer conversions that don't cast away constness? 2846 if (!PointeeTy.isConstQualified()) 2847 AddPointerWithMoreQualifiedTypeVariants 2848 (Context.getPointerType(PointeeTy.withConst())); 2849 if (!PointeeTy.isVolatileQualified()) 2850 AddPointerWithMoreQualifiedTypeVariants 2851 (Context.getPointerType(PointeeTy.withVolatile())); 2852 if (!PointeeTy.isRestrictQualified()) 2853 AddPointerWithMoreQualifiedTypeVariants 2854 (Context.getPointerType(PointeeTy.withRestrict())); 2855 } 2856 2857 return true; 2858} 2859 2860/// AddMemberPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty 2861/// to the set of pointer types along with any more-qualified variants of 2862/// that type. For example, if @p Ty is "int const *", this routine 2863/// will add "int const *", "int const volatile *", "int const 2864/// restrict *", and "int const volatile restrict *" to the set of 2865/// pointer types. Returns true if the add of @p Ty itself succeeded, 2866/// false otherwise. 2867bool 2868BuiltinCandidateTypeSet::AddMemberPointerWithMoreQualifiedTypeVariants( 2869 QualType Ty) { 2870 // Insert this type. 2871 if (!MemberPointerTypes.insert(Ty)) 2872 return false; 2873 2874 if (const MemberPointerType *PointerTy = Ty->getAs<MemberPointerType>()) { 2875 QualType PointeeTy = PointerTy->getPointeeType(); 2876 const Type *ClassTy = PointerTy->getClass(); 2877 // FIXME: Optimize this so that we don't keep trying to add the same types. 2878 2879 if (!PointeeTy.isConstQualified()) 2880 AddMemberPointerWithMoreQualifiedTypeVariants 2881 (Context.getMemberPointerType(PointeeTy.withConst(), ClassTy)); 2882 if (!PointeeTy.isVolatileQualified()) 2883 AddMemberPointerWithMoreQualifiedTypeVariants 2884 (Context.getMemberPointerType(PointeeTy.withVolatile(), ClassTy)); 2885 if (!PointeeTy.isRestrictQualified()) 2886 AddMemberPointerWithMoreQualifiedTypeVariants 2887 (Context.getMemberPointerType(PointeeTy.withRestrict(), ClassTy)); 2888 } 2889 2890 return true; 2891} 2892 2893/// AddTypesConvertedFrom - Add each of the types to which the type @p 2894/// Ty can be implicit converted to the given set of @p Types. We're 2895/// primarily interested in pointer types and enumeration types. We also 2896/// take member pointer types, for the conditional operator. 2897/// AllowUserConversions is true if we should look at the conversion 2898/// functions of a class type, and AllowExplicitConversions if we 2899/// should also include the explicit conversion functions of a class 2900/// type. 2901void 2902BuiltinCandidateTypeSet::AddTypesConvertedFrom(QualType Ty, 2903 bool AllowUserConversions, 2904 bool AllowExplicitConversions) { 2905 // Only deal with canonical types. 2906 Ty = Context.getCanonicalType(Ty); 2907 2908 // Look through reference types; they aren't part of the type of an 2909 // expression for the purposes of conversions. 2910 if (const ReferenceType *RefTy = Ty->getAs<ReferenceType>()) 2911 Ty = RefTy->getPointeeType(); 2912 2913 // We don't care about qualifiers on the type. 2914 Ty = Ty.getUnqualifiedType(); 2915 2916 if (const PointerType *PointerTy = Ty->getAs<PointerType>()) { 2917 QualType PointeeTy = PointerTy->getPointeeType(); 2918 2919 // Insert our type, and its more-qualified variants, into the set 2920 // of types. 2921 if (!AddPointerWithMoreQualifiedTypeVariants(Ty)) 2922 return; 2923 2924 // Add 'cv void*' to our set of types. 2925 if (!Ty->isVoidType()) { 2926 QualType QualVoid 2927 = Context.VoidTy.getQualifiedType(PointeeTy.getCVRQualifiers()); 2928 AddPointerWithMoreQualifiedTypeVariants(Context.getPointerType(QualVoid)); 2929 } 2930 2931 // If this is a pointer to a class type, add pointers to its bases 2932 // (with the same level of cv-qualification as the original 2933 // derived class, of course). 2934 if (const RecordType *PointeeRec = PointeeTy->getAs<RecordType>()) { 2935 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(PointeeRec->getDecl()); 2936 for (CXXRecordDecl::base_class_iterator Base = ClassDecl->bases_begin(); 2937 Base != ClassDecl->bases_end(); ++Base) { 2938 QualType BaseTy = Context.getCanonicalType(Base->getType()); 2939 BaseTy = BaseTy.getQualifiedType(PointeeTy.getCVRQualifiers()); 2940 2941 // Add the pointer type, recursively, so that we get all of 2942 // the indirect base classes, too. 2943 AddTypesConvertedFrom(Context.getPointerType(BaseTy), false, false); 2944 } 2945 } 2946 } else if (Ty->isMemberPointerType()) { 2947 // Member pointers are far easier, since the pointee can't be converted. 2948 if (!AddMemberPointerWithMoreQualifiedTypeVariants(Ty)) 2949 return; 2950 } else if (Ty->isEnumeralType()) { 2951 EnumerationTypes.insert(Ty); 2952 } else if (AllowUserConversions) { 2953 if (const RecordType *TyRec = Ty->getAs<RecordType>()) { 2954 if (SemaRef.RequireCompleteType(SourceLocation(), Ty, 0)) { 2955 // No conversion functions in incomplete types. 2956 return; 2957 } 2958 2959 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 2960 // FIXME: Visit conversion functions in the base classes, too. 2961 OverloadedFunctionDecl *Conversions 2962 = ClassDecl->getConversionFunctions(); 2963 for (OverloadedFunctionDecl::function_iterator Func 2964 = Conversions->function_begin(); 2965 Func != Conversions->function_end(); ++Func) { 2966 CXXConversionDecl *Conv; 2967 FunctionTemplateDecl *ConvTemplate; 2968 GetFunctionAndTemplate(*Func, Conv, ConvTemplate); 2969 2970 // Skip conversion function templates; they don't tell us anything 2971 // about which builtin types we can convert to. 2972 if (ConvTemplate) 2973 continue; 2974 2975 if (AllowExplicitConversions || !Conv->isExplicit()) 2976 AddTypesConvertedFrom(Conv->getConversionType(), false, false); 2977 } 2978 } 2979 } 2980} 2981 2982/// \brief Helper function for AddBuiltinOperatorCandidates() that adds 2983/// the volatile- and non-volatile-qualified assignment operators for the 2984/// given type to the candidate set. 2985static void AddBuiltinAssignmentOperatorCandidates(Sema &S, 2986 QualType T, 2987 Expr **Args, 2988 unsigned NumArgs, 2989 OverloadCandidateSet &CandidateSet) { 2990 QualType ParamTypes[2]; 2991 2992 // T& operator=(T&, T) 2993 ParamTypes[0] = S.Context.getLValueReferenceType(T); 2994 ParamTypes[1] = T; 2995 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 2996 /*IsAssignmentOperator=*/true); 2997 2998 if (!S.Context.getCanonicalType(T).isVolatileQualified()) { 2999 // volatile T& operator=(volatile T&, T) 3000 ParamTypes[0] = S.Context.getLValueReferenceType(T.withVolatile()); 3001 ParamTypes[1] = T; 3002 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3003 /*IsAssignmentOperator=*/true); 3004 } 3005} 3006 3007/// AddBuiltinOperatorCandidates - Add the appropriate built-in 3008/// operator overloads to the candidate set (C++ [over.built]), based 3009/// on the operator @p Op and the arguments given. For example, if the 3010/// operator is a binary '+', this routine might add "int 3011/// operator+(int, int)" to cover integer addition. 3012void 3013Sema::AddBuiltinOperatorCandidates(OverloadedOperatorKind Op, 3014 Expr **Args, unsigned NumArgs, 3015 OverloadCandidateSet& CandidateSet) { 3016 // The set of "promoted arithmetic types", which are the arithmetic 3017 // types are that preserved by promotion (C++ [over.built]p2). Note 3018 // that the first few of these types are the promoted integral 3019 // types; these types need to be first. 3020 // FIXME: What about complex? 3021 const unsigned FirstIntegralType = 0; 3022 const unsigned LastIntegralType = 13; 3023 const unsigned FirstPromotedIntegralType = 7, 3024 LastPromotedIntegralType = 13; 3025 const unsigned FirstPromotedArithmeticType = 7, 3026 LastPromotedArithmeticType = 16; 3027 const unsigned NumArithmeticTypes = 16; 3028 QualType ArithmeticTypes[NumArithmeticTypes] = { 3029 Context.BoolTy, Context.CharTy, Context.WCharTy, 3030// FIXME: Context.Char16Ty, Context.Char32Ty, 3031 Context.SignedCharTy, Context.ShortTy, 3032 Context.UnsignedCharTy, Context.UnsignedShortTy, 3033 Context.IntTy, Context.LongTy, Context.LongLongTy, 3034 Context.UnsignedIntTy, Context.UnsignedLongTy, Context.UnsignedLongLongTy, 3035 Context.FloatTy, Context.DoubleTy, Context.LongDoubleTy 3036 }; 3037 3038 // Find all of the types that the arguments can convert to, but only 3039 // if the operator we're looking at has built-in operator candidates 3040 // that make use of these types. 3041 BuiltinCandidateTypeSet CandidateTypes(*this); 3042 if (Op == OO_Less || Op == OO_Greater || Op == OO_LessEqual || 3043 Op == OO_GreaterEqual || Op == OO_EqualEqual || Op == OO_ExclaimEqual || 3044 Op == OO_Plus || (Op == OO_Minus && NumArgs == 2) || Op == OO_Equal || 3045 Op == OO_PlusEqual || Op == OO_MinusEqual || Op == OO_Subscript || 3046 Op == OO_ArrowStar || Op == OO_PlusPlus || Op == OO_MinusMinus || 3047 (Op == OO_Star && NumArgs == 1) || Op == OO_Conditional) { 3048 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 3049 CandidateTypes.AddTypesConvertedFrom(Args[ArgIdx]->getType(), 3050 true, 3051 (Op == OO_Exclaim || 3052 Op == OO_AmpAmp || 3053 Op == OO_PipePipe)); 3054 } 3055 3056 bool isComparison = false; 3057 switch (Op) { 3058 case OO_None: 3059 case NUM_OVERLOADED_OPERATORS: 3060 assert(false && "Expected an overloaded operator"); 3061 break; 3062 3063 case OO_Star: // '*' is either unary or binary 3064 if (NumArgs == 1) 3065 goto UnaryStar; 3066 else 3067 goto BinaryStar; 3068 break; 3069 3070 case OO_Plus: // '+' is either unary or binary 3071 if (NumArgs == 1) 3072 goto UnaryPlus; 3073 else 3074 goto BinaryPlus; 3075 break; 3076 3077 case OO_Minus: // '-' is either unary or binary 3078 if (NumArgs == 1) 3079 goto UnaryMinus; 3080 else 3081 goto BinaryMinus; 3082 break; 3083 3084 case OO_Amp: // '&' is either unary or binary 3085 if (NumArgs == 1) 3086 goto UnaryAmp; 3087 else 3088 goto BinaryAmp; 3089 3090 case OO_PlusPlus: 3091 case OO_MinusMinus: 3092 // C++ [over.built]p3: 3093 // 3094 // For every pair (T, VQ), where T is an arithmetic type, and VQ 3095 // is either volatile or empty, there exist candidate operator 3096 // functions of the form 3097 // 3098 // VQ T& operator++(VQ T&); 3099 // T operator++(VQ T&, int); 3100 // 3101 // C++ [over.built]p4: 3102 // 3103 // For every pair (T, VQ), where T is an arithmetic type other 3104 // than bool, and VQ is either volatile or empty, there exist 3105 // candidate operator functions of the form 3106 // 3107 // VQ T& operator--(VQ T&); 3108 // T operator--(VQ T&, int); 3109 for (unsigned Arith = (Op == OO_PlusPlus? 0 : 1); 3110 Arith < NumArithmeticTypes; ++Arith) { 3111 QualType ArithTy = ArithmeticTypes[Arith]; 3112 QualType ParamTypes[2] 3113 = { Context.getLValueReferenceType(ArithTy), Context.IntTy }; 3114 3115 // Non-volatile version. 3116 if (NumArgs == 1) 3117 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3118 else 3119 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 3120 3121 // Volatile version 3122 ParamTypes[0] = Context.getLValueReferenceType(ArithTy.withVolatile()); 3123 if (NumArgs == 1) 3124 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3125 else 3126 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 3127 } 3128 3129 // C++ [over.built]p5: 3130 // 3131 // For every pair (T, VQ), where T is a cv-qualified or 3132 // cv-unqualified object type, and VQ is either volatile or 3133 // empty, there exist candidate operator functions of the form 3134 // 3135 // T*VQ& operator++(T*VQ&); 3136 // T*VQ& operator--(T*VQ&); 3137 // T* operator++(T*VQ&, int); 3138 // T* operator--(T*VQ&, int); 3139 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3140 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3141 // Skip pointer types that aren't pointers to object types. 3142 if (!(*Ptr)->getAs<PointerType>()->getPointeeType()->isObjectType()) 3143 continue; 3144 3145 QualType ParamTypes[2] = { 3146 Context.getLValueReferenceType(*Ptr), Context.IntTy 3147 }; 3148 3149 // Without volatile 3150 if (NumArgs == 1) 3151 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3152 else 3153 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3154 3155 if (!Context.getCanonicalType(*Ptr).isVolatileQualified()) { 3156 // With volatile 3157 ParamTypes[0] = Context.getLValueReferenceType((*Ptr).withVolatile()); 3158 if (NumArgs == 1) 3159 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3160 else 3161 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3162 } 3163 } 3164 break; 3165 3166 UnaryStar: 3167 // C++ [over.built]p6: 3168 // For every cv-qualified or cv-unqualified object type T, there 3169 // exist candidate operator functions of the form 3170 // 3171 // T& operator*(T*); 3172 // 3173 // C++ [over.built]p7: 3174 // For every function type T, there exist candidate operator 3175 // functions of the form 3176 // T& operator*(T*); 3177 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3178 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3179 QualType ParamTy = *Ptr; 3180 QualType PointeeTy = ParamTy->getAs<PointerType>()->getPointeeType(); 3181 AddBuiltinCandidate(Context.getLValueReferenceType(PointeeTy), 3182 &ParamTy, Args, 1, CandidateSet); 3183 } 3184 break; 3185 3186 UnaryPlus: 3187 // C++ [over.built]p8: 3188 // For every type T, there exist candidate operator functions of 3189 // the form 3190 // 3191 // T* operator+(T*); 3192 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3193 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3194 QualType ParamTy = *Ptr; 3195 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet); 3196 } 3197 3198 // Fall through 3199 3200 UnaryMinus: 3201 // C++ [over.built]p9: 3202 // For every promoted arithmetic type T, there exist candidate 3203 // operator functions of the form 3204 // 3205 // T operator+(T); 3206 // T operator-(T); 3207 for (unsigned Arith = FirstPromotedArithmeticType; 3208 Arith < LastPromotedArithmeticType; ++Arith) { 3209 QualType ArithTy = ArithmeticTypes[Arith]; 3210 AddBuiltinCandidate(ArithTy, &ArithTy, Args, 1, CandidateSet); 3211 } 3212 break; 3213 3214 case OO_Tilde: 3215 // C++ [over.built]p10: 3216 // For every promoted integral type T, there exist candidate 3217 // operator functions of the form 3218 // 3219 // T operator~(T); 3220 for (unsigned Int = FirstPromotedIntegralType; 3221 Int < LastPromotedIntegralType; ++Int) { 3222 QualType IntTy = ArithmeticTypes[Int]; 3223 AddBuiltinCandidate(IntTy, &IntTy, Args, 1, CandidateSet); 3224 } 3225 break; 3226 3227 case OO_New: 3228 case OO_Delete: 3229 case OO_Array_New: 3230 case OO_Array_Delete: 3231 case OO_Call: 3232 assert(false && "Special operators don't use AddBuiltinOperatorCandidates"); 3233 break; 3234 3235 case OO_Comma: 3236 UnaryAmp: 3237 case OO_Arrow: 3238 // C++ [over.match.oper]p3: 3239 // -- For the operator ',', the unary operator '&', or the 3240 // operator '->', the built-in candidates set is empty. 3241 break; 3242 3243 case OO_EqualEqual: 3244 case OO_ExclaimEqual: 3245 // C++ [over.match.oper]p16: 3246 // For every pointer to member type T, there exist candidate operator 3247 // functions of the form 3248 // 3249 // bool operator==(T,T); 3250 // bool operator!=(T,T); 3251 for (BuiltinCandidateTypeSet::iterator 3252 MemPtr = CandidateTypes.member_pointer_begin(), 3253 MemPtrEnd = CandidateTypes.member_pointer_end(); 3254 MemPtr != MemPtrEnd; 3255 ++MemPtr) { 3256 QualType ParamTypes[2] = { *MemPtr, *MemPtr }; 3257 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 3258 } 3259 3260 // Fall through 3261 3262 case OO_Less: 3263 case OO_Greater: 3264 case OO_LessEqual: 3265 case OO_GreaterEqual: 3266 // C++ [over.built]p15: 3267 // 3268 // For every pointer or enumeration type T, there exist 3269 // candidate operator functions of the form 3270 // 3271 // bool operator<(T, T); 3272 // bool operator>(T, T); 3273 // bool operator<=(T, T); 3274 // bool operator>=(T, T); 3275 // bool operator==(T, T); 3276 // bool operator!=(T, T); 3277 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3278 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3279 QualType ParamTypes[2] = { *Ptr, *Ptr }; 3280 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 3281 } 3282 for (BuiltinCandidateTypeSet::iterator Enum 3283 = CandidateTypes.enumeration_begin(); 3284 Enum != CandidateTypes.enumeration_end(); ++Enum) { 3285 QualType ParamTypes[2] = { *Enum, *Enum }; 3286 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 3287 } 3288 3289 // Fall through. 3290 isComparison = true; 3291 3292 BinaryPlus: 3293 BinaryMinus: 3294 if (!isComparison) { 3295 // We didn't fall through, so we must have OO_Plus or OO_Minus. 3296 3297 // C++ [over.built]p13: 3298 // 3299 // For every cv-qualified or cv-unqualified object type T 3300 // there exist candidate operator functions of the form 3301 // 3302 // T* operator+(T*, ptrdiff_t); 3303 // T& operator[](T*, ptrdiff_t); [BELOW] 3304 // T* operator-(T*, ptrdiff_t); 3305 // T* operator+(ptrdiff_t, T*); 3306 // T& operator[](ptrdiff_t, T*); [BELOW] 3307 // 3308 // C++ [over.built]p14: 3309 // 3310 // For every T, where T is a pointer to object type, there 3311 // exist candidate operator functions of the form 3312 // 3313 // ptrdiff_t operator-(T, T); 3314 for (BuiltinCandidateTypeSet::iterator Ptr 3315 = CandidateTypes.pointer_begin(); 3316 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3317 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 3318 3319 // operator+(T*, ptrdiff_t) or operator-(T*, ptrdiff_t) 3320 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3321 3322 if (Op == OO_Plus) { 3323 // T* operator+(ptrdiff_t, T*); 3324 ParamTypes[0] = ParamTypes[1]; 3325 ParamTypes[1] = *Ptr; 3326 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3327 } else { 3328 // ptrdiff_t operator-(T, T); 3329 ParamTypes[1] = *Ptr; 3330 AddBuiltinCandidate(Context.getPointerDiffType(), ParamTypes, 3331 Args, 2, CandidateSet); 3332 } 3333 } 3334 } 3335 // Fall through 3336 3337 case OO_Slash: 3338 BinaryStar: 3339 Conditional: 3340 // C++ [over.built]p12: 3341 // 3342 // For every pair of promoted arithmetic types L and R, there 3343 // exist candidate operator functions of the form 3344 // 3345 // LR operator*(L, R); 3346 // LR operator/(L, R); 3347 // LR operator+(L, R); 3348 // LR operator-(L, R); 3349 // bool operator<(L, R); 3350 // bool operator>(L, R); 3351 // bool operator<=(L, R); 3352 // bool operator>=(L, R); 3353 // bool operator==(L, R); 3354 // bool operator!=(L, R); 3355 // 3356 // where LR is the result of the usual arithmetic conversions 3357 // between types L and R. 3358 // 3359 // C++ [over.built]p24: 3360 // 3361 // For every pair of promoted arithmetic types L and R, there exist 3362 // candidate operator functions of the form 3363 // 3364 // LR operator?(bool, L, R); 3365 // 3366 // where LR is the result of the usual arithmetic conversions 3367 // between types L and R. 3368 // Our candidates ignore the first parameter. 3369 for (unsigned Left = FirstPromotedArithmeticType; 3370 Left < LastPromotedArithmeticType; ++Left) { 3371 for (unsigned Right = FirstPromotedArithmeticType; 3372 Right < LastPromotedArithmeticType; ++Right) { 3373 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 3374 QualType Result 3375 = isComparison 3376 ? Context.BoolTy 3377 : Context.UsualArithmeticConversionsType(LandR[0], LandR[1]); 3378 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 3379 } 3380 } 3381 break; 3382 3383 case OO_Percent: 3384 BinaryAmp: 3385 case OO_Caret: 3386 case OO_Pipe: 3387 case OO_LessLess: 3388 case OO_GreaterGreater: 3389 // C++ [over.built]p17: 3390 // 3391 // For every pair of promoted integral types L and R, there 3392 // exist candidate operator functions of the form 3393 // 3394 // LR operator%(L, R); 3395 // LR operator&(L, R); 3396 // LR operator^(L, R); 3397 // LR operator|(L, R); 3398 // L operator<<(L, R); 3399 // L operator>>(L, R); 3400 // 3401 // where LR is the result of the usual arithmetic conversions 3402 // between types L and R. 3403 for (unsigned Left = FirstPromotedIntegralType; 3404 Left < LastPromotedIntegralType; ++Left) { 3405 for (unsigned Right = FirstPromotedIntegralType; 3406 Right < LastPromotedIntegralType; ++Right) { 3407 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 3408 QualType Result = (Op == OO_LessLess || Op == OO_GreaterGreater) 3409 ? LandR[0] 3410 : Context.UsualArithmeticConversionsType(LandR[0], LandR[1]); 3411 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 3412 } 3413 } 3414 break; 3415 3416 case OO_Equal: 3417 // C++ [over.built]p20: 3418 // 3419 // For every pair (T, VQ), where T is an enumeration or 3420 // pointer to member type and VQ is either volatile or 3421 // empty, there exist candidate operator functions of the form 3422 // 3423 // VQ T& operator=(VQ T&, T); 3424 for (BuiltinCandidateTypeSet::iterator 3425 Enum = CandidateTypes.enumeration_begin(), 3426 EnumEnd = CandidateTypes.enumeration_end(); 3427 Enum != EnumEnd; ++Enum) 3428 AddBuiltinAssignmentOperatorCandidates(*this, *Enum, Args, 2, 3429 CandidateSet); 3430 for (BuiltinCandidateTypeSet::iterator 3431 MemPtr = CandidateTypes.member_pointer_begin(), 3432 MemPtrEnd = CandidateTypes.member_pointer_end(); 3433 MemPtr != MemPtrEnd; ++MemPtr) 3434 AddBuiltinAssignmentOperatorCandidates(*this, *MemPtr, Args, 2, 3435 CandidateSet); 3436 // Fall through. 3437 3438 case OO_PlusEqual: 3439 case OO_MinusEqual: 3440 // C++ [over.built]p19: 3441 // 3442 // For every pair (T, VQ), where T is any type and VQ is either 3443 // volatile or empty, there exist candidate operator functions 3444 // of the form 3445 // 3446 // T*VQ& operator=(T*VQ&, T*); 3447 // 3448 // C++ [over.built]p21: 3449 // 3450 // For every pair (T, VQ), where T is a cv-qualified or 3451 // cv-unqualified object type and VQ is either volatile or 3452 // empty, there exist candidate operator functions of the form 3453 // 3454 // T*VQ& operator+=(T*VQ&, ptrdiff_t); 3455 // T*VQ& operator-=(T*VQ&, ptrdiff_t); 3456 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3457 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3458 QualType ParamTypes[2]; 3459 ParamTypes[1] = (Op == OO_Equal)? *Ptr : Context.getPointerDiffType(); 3460 3461 // non-volatile version 3462 ParamTypes[0] = Context.getLValueReferenceType(*Ptr); 3463 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3464 /*IsAssigmentOperator=*/Op == OO_Equal); 3465 3466 if (!Context.getCanonicalType(*Ptr).isVolatileQualified()) { 3467 // volatile version 3468 ParamTypes[0] = Context.getLValueReferenceType((*Ptr).withVolatile()); 3469 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3470 /*IsAssigmentOperator=*/Op == OO_Equal); 3471 } 3472 } 3473 // Fall through. 3474 3475 case OO_StarEqual: 3476 case OO_SlashEqual: 3477 // C++ [over.built]p18: 3478 // 3479 // For every triple (L, VQ, R), where L is an arithmetic type, 3480 // VQ is either volatile or empty, and R is a promoted 3481 // arithmetic type, there exist candidate operator functions of 3482 // the form 3483 // 3484 // VQ L& operator=(VQ L&, R); 3485 // VQ L& operator*=(VQ L&, R); 3486 // VQ L& operator/=(VQ L&, R); 3487 // VQ L& operator+=(VQ L&, R); 3488 // VQ L& operator-=(VQ L&, R); 3489 for (unsigned Left = 0; Left < NumArithmeticTypes; ++Left) { 3490 for (unsigned Right = FirstPromotedArithmeticType; 3491 Right < LastPromotedArithmeticType; ++Right) { 3492 QualType ParamTypes[2]; 3493 ParamTypes[1] = ArithmeticTypes[Right]; 3494 3495 // Add this built-in operator as a candidate (VQ is empty). 3496 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 3497 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3498 /*IsAssigmentOperator=*/Op == OO_Equal); 3499 3500 // Add this built-in operator as a candidate (VQ is 'volatile'). 3501 ParamTypes[0] = ArithmeticTypes[Left].withVolatile(); 3502 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 3503 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3504 /*IsAssigmentOperator=*/Op == OO_Equal); 3505 } 3506 } 3507 break; 3508 3509 case OO_PercentEqual: 3510 case OO_LessLessEqual: 3511 case OO_GreaterGreaterEqual: 3512 case OO_AmpEqual: 3513 case OO_CaretEqual: 3514 case OO_PipeEqual: 3515 // C++ [over.built]p22: 3516 // 3517 // For every triple (L, VQ, R), where L is an integral type, VQ 3518 // is either volatile or empty, and R is a promoted integral 3519 // type, there exist candidate operator functions of the form 3520 // 3521 // VQ L& operator%=(VQ L&, R); 3522 // VQ L& operator<<=(VQ L&, R); 3523 // VQ L& operator>>=(VQ L&, R); 3524 // VQ L& operator&=(VQ L&, R); 3525 // VQ L& operator^=(VQ L&, R); 3526 // VQ L& operator|=(VQ L&, R); 3527 for (unsigned Left = FirstIntegralType; Left < LastIntegralType; ++Left) { 3528 for (unsigned Right = FirstPromotedIntegralType; 3529 Right < LastPromotedIntegralType; ++Right) { 3530 QualType ParamTypes[2]; 3531 ParamTypes[1] = ArithmeticTypes[Right]; 3532 3533 // Add this built-in operator as a candidate (VQ is empty). 3534 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 3535 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 3536 3537 // Add this built-in operator as a candidate (VQ is 'volatile'). 3538 ParamTypes[0] = ArithmeticTypes[Left]; 3539 ParamTypes[0].addVolatile(); 3540 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 3541 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 3542 } 3543 } 3544 break; 3545 3546 case OO_Exclaim: { 3547 // C++ [over.operator]p23: 3548 // 3549 // There also exist candidate operator functions of the form 3550 // 3551 // bool operator!(bool); 3552 // bool operator&&(bool, bool); [BELOW] 3553 // bool operator||(bool, bool); [BELOW] 3554 QualType ParamTy = Context.BoolTy; 3555 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet, 3556 /*IsAssignmentOperator=*/false, 3557 /*NumContextualBoolArguments=*/1); 3558 break; 3559 } 3560 3561 case OO_AmpAmp: 3562 case OO_PipePipe: { 3563 // C++ [over.operator]p23: 3564 // 3565 // There also exist candidate operator functions of the form 3566 // 3567 // bool operator!(bool); [ABOVE] 3568 // bool operator&&(bool, bool); 3569 // bool operator||(bool, bool); 3570 QualType ParamTypes[2] = { Context.BoolTy, Context.BoolTy }; 3571 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet, 3572 /*IsAssignmentOperator=*/false, 3573 /*NumContextualBoolArguments=*/2); 3574 break; 3575 } 3576 3577 case OO_Subscript: 3578 // C++ [over.built]p13: 3579 // 3580 // For every cv-qualified or cv-unqualified object type T there 3581 // exist candidate operator functions of the form 3582 // 3583 // T* operator+(T*, ptrdiff_t); [ABOVE] 3584 // T& operator[](T*, ptrdiff_t); 3585 // T* operator-(T*, ptrdiff_t); [ABOVE] 3586 // T* operator+(ptrdiff_t, T*); [ABOVE] 3587 // T& operator[](ptrdiff_t, T*); 3588 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3589 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3590 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 3591 QualType PointeeType = (*Ptr)->getAs<PointerType>()->getPointeeType(); 3592 QualType ResultTy = Context.getLValueReferenceType(PointeeType); 3593 3594 // T& operator[](T*, ptrdiff_t) 3595 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 3596 3597 // T& operator[](ptrdiff_t, T*); 3598 ParamTypes[0] = ParamTypes[1]; 3599 ParamTypes[1] = *Ptr; 3600 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 3601 } 3602 break; 3603 3604 case OO_ArrowStar: 3605 // FIXME: No support for pointer-to-members yet. 3606 break; 3607 3608 case OO_Conditional: 3609 // Note that we don't consider the first argument, since it has been 3610 // contextually converted to bool long ago. The candidates below are 3611 // therefore added as binary. 3612 // 3613 // C++ [over.built]p24: 3614 // For every type T, where T is a pointer or pointer-to-member type, 3615 // there exist candidate operator functions of the form 3616 // 3617 // T operator?(bool, T, T); 3618 // 3619 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(), 3620 E = CandidateTypes.pointer_end(); Ptr != E; ++Ptr) { 3621 QualType ParamTypes[2] = { *Ptr, *Ptr }; 3622 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3623 } 3624 for (BuiltinCandidateTypeSet::iterator Ptr = 3625 CandidateTypes.member_pointer_begin(), 3626 E = CandidateTypes.member_pointer_end(); Ptr != E; ++Ptr) { 3627 QualType ParamTypes[2] = { *Ptr, *Ptr }; 3628 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3629 } 3630 goto Conditional; 3631 } 3632} 3633 3634/// \brief Add function candidates found via argument-dependent lookup 3635/// to the set of overloading candidates. 3636/// 3637/// This routine performs argument-dependent name lookup based on the 3638/// given function name (which may also be an operator name) and adds 3639/// all of the overload candidates found by ADL to the overload 3640/// candidate set (C++ [basic.lookup.argdep]). 3641void 3642Sema::AddArgumentDependentLookupCandidates(DeclarationName Name, 3643 Expr **Args, unsigned NumArgs, 3644 bool HasExplicitTemplateArgs, 3645 const TemplateArgument *ExplicitTemplateArgs, 3646 unsigned NumExplicitTemplateArgs, 3647 OverloadCandidateSet& CandidateSet, 3648 bool PartialOverloading) { 3649 FunctionSet Functions; 3650 3651 // FIXME: Should we be trafficking in canonical function decls throughout? 3652 3653 // Record all of the function candidates that we've already 3654 // added to the overload set, so that we don't add those same 3655 // candidates a second time. 3656 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 3657 CandEnd = CandidateSet.end(); 3658 Cand != CandEnd; ++Cand) 3659 if (Cand->Function) { 3660 Functions.insert(Cand->Function); 3661 if (FunctionTemplateDecl *FunTmpl = Cand->Function->getPrimaryTemplate()) 3662 Functions.insert(FunTmpl); 3663 } 3664 3665 // FIXME: Pass in the explicit template arguments? 3666 ArgumentDependentLookup(Name, Args, NumArgs, Functions); 3667 3668 // Erase all of the candidates we already knew about. 3669 // FIXME: This is suboptimal. Is there a better way? 3670 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 3671 CandEnd = CandidateSet.end(); 3672 Cand != CandEnd; ++Cand) 3673 if (Cand->Function) { 3674 Functions.erase(Cand->Function); 3675 if (FunctionTemplateDecl *FunTmpl = Cand->Function->getPrimaryTemplate()) 3676 Functions.erase(FunTmpl); 3677 } 3678 3679 // For each of the ADL candidates we found, add it to the overload 3680 // set. 3681 for (FunctionSet::iterator Func = Functions.begin(), 3682 FuncEnd = Functions.end(); 3683 Func != FuncEnd; ++Func) { 3684 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*Func)) { 3685 if (HasExplicitTemplateArgs) 3686 continue; 3687 3688 AddOverloadCandidate(FD, Args, NumArgs, CandidateSet, 3689 false, false, PartialOverloading); 3690 } else 3691 AddTemplateOverloadCandidate(cast<FunctionTemplateDecl>(*Func), 3692 HasExplicitTemplateArgs, 3693 ExplicitTemplateArgs, 3694 NumExplicitTemplateArgs, 3695 Args, NumArgs, CandidateSet); 3696 } 3697} 3698 3699/// isBetterOverloadCandidate - Determines whether the first overload 3700/// candidate is a better candidate than the second (C++ 13.3.3p1). 3701bool 3702Sema::isBetterOverloadCandidate(const OverloadCandidate& Cand1, 3703 const OverloadCandidate& Cand2) { 3704 // Define viable functions to be better candidates than non-viable 3705 // functions. 3706 if (!Cand2.Viable) 3707 return Cand1.Viable; 3708 else if (!Cand1.Viable) 3709 return false; 3710 3711 // C++ [over.match.best]p1: 3712 // 3713 // -- if F is a static member function, ICS1(F) is defined such 3714 // that ICS1(F) is neither better nor worse than ICS1(G) for 3715 // any function G, and, symmetrically, ICS1(G) is neither 3716 // better nor worse than ICS1(F). 3717 unsigned StartArg = 0; 3718 if (Cand1.IgnoreObjectArgument || Cand2.IgnoreObjectArgument) 3719 StartArg = 1; 3720 3721 // C++ [over.match.best]p1: 3722 // A viable function F1 is defined to be a better function than another 3723 // viable function F2 if for all arguments i, ICSi(F1) is not a worse 3724 // conversion sequence than ICSi(F2), and then... 3725 unsigned NumArgs = Cand1.Conversions.size(); 3726 assert(Cand2.Conversions.size() == NumArgs && "Overload candidate mismatch"); 3727 bool HasBetterConversion = false; 3728 for (unsigned ArgIdx = StartArg; ArgIdx < NumArgs; ++ArgIdx) { 3729 switch (CompareImplicitConversionSequences(Cand1.Conversions[ArgIdx], 3730 Cand2.Conversions[ArgIdx])) { 3731 case ImplicitConversionSequence::Better: 3732 // Cand1 has a better conversion sequence. 3733 HasBetterConversion = true; 3734 break; 3735 3736 case ImplicitConversionSequence::Worse: 3737 // Cand1 can't be better than Cand2. 3738 return false; 3739 3740 case ImplicitConversionSequence::Indistinguishable: 3741 // Do nothing. 3742 break; 3743 } 3744 } 3745 3746 // -- for some argument j, ICSj(F1) is a better conversion sequence than 3747 // ICSj(F2), or, if not that, 3748 if (HasBetterConversion) 3749 return true; 3750 3751 // - F1 is a non-template function and F2 is a function template 3752 // specialization, or, if not that, 3753 if (Cand1.Function && !Cand1.Function->getPrimaryTemplate() && 3754 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 3755 return true; 3756 3757 // -- F1 and F2 are function template specializations, and the function 3758 // template for F1 is more specialized than the template for F2 3759 // according to the partial ordering rules described in 14.5.5.2, or, 3760 // if not that, 3761 if (Cand1.Function && Cand1.Function->getPrimaryTemplate() && 3762 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 3763 if (FunctionTemplateDecl *BetterTemplate 3764 = getMoreSpecializedTemplate(Cand1.Function->getPrimaryTemplate(), 3765 Cand2.Function->getPrimaryTemplate(), 3766 isa<CXXConversionDecl>(Cand1.Function)? TPOC_Conversion 3767 : TPOC_Call)) 3768 return BetterTemplate == Cand1.Function->getPrimaryTemplate(); 3769 3770 // -- the context is an initialization by user-defined conversion 3771 // (see 8.5, 13.3.1.5) and the standard conversion sequence 3772 // from the return type of F1 to the destination type (i.e., 3773 // the type of the entity being initialized) is a better 3774 // conversion sequence than the standard conversion sequence 3775 // from the return type of F2 to the destination type. 3776 if (Cand1.Function && Cand2.Function && 3777 isa<CXXConversionDecl>(Cand1.Function) && 3778 isa<CXXConversionDecl>(Cand2.Function)) { 3779 switch (CompareStandardConversionSequences(Cand1.FinalConversion, 3780 Cand2.FinalConversion)) { 3781 case ImplicitConversionSequence::Better: 3782 // Cand1 has a better conversion sequence. 3783 return true; 3784 3785 case ImplicitConversionSequence::Worse: 3786 // Cand1 can't be better than Cand2. 3787 return false; 3788 3789 case ImplicitConversionSequence::Indistinguishable: 3790 // Do nothing 3791 break; 3792 } 3793 } 3794 3795 return false; 3796} 3797 3798/// \brief Computes the best viable function (C++ 13.3.3) 3799/// within an overload candidate set. 3800/// 3801/// \param CandidateSet the set of candidate functions. 3802/// 3803/// \param Loc the location of the function name (or operator symbol) for 3804/// which overload resolution occurs. 3805/// 3806/// \param Best f overload resolution was successful or found a deleted 3807/// function, Best points to the candidate function found. 3808/// 3809/// \returns The result of overload resolution. 3810Sema::OverloadingResult 3811Sema::BestViableFunction(OverloadCandidateSet& CandidateSet, 3812 SourceLocation Loc, 3813 OverloadCandidateSet::iterator& Best) { 3814 // Find the best viable function. 3815 Best = CandidateSet.end(); 3816 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 3817 Cand != CandidateSet.end(); ++Cand) { 3818 if (Cand->Viable) { 3819 if (Best == CandidateSet.end() || isBetterOverloadCandidate(*Cand, *Best)) 3820 Best = Cand; 3821 } 3822 } 3823 3824 // If we didn't find any viable functions, abort. 3825 if (Best == CandidateSet.end()) 3826 return OR_No_Viable_Function; 3827 3828 // Make sure that this function is better than every other viable 3829 // function. If not, we have an ambiguity. 3830 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 3831 Cand != CandidateSet.end(); ++Cand) { 3832 if (Cand->Viable && 3833 Cand != Best && 3834 !isBetterOverloadCandidate(*Best, *Cand)) { 3835 Best = CandidateSet.end(); 3836 return OR_Ambiguous; 3837 } 3838 } 3839 3840 // Best is the best viable function. 3841 if (Best->Function && 3842 (Best->Function->isDeleted() || 3843 Best->Function->getAttr<UnavailableAttr>())) 3844 return OR_Deleted; 3845 3846 // C++ [basic.def.odr]p2: 3847 // An overloaded function is used if it is selected by overload resolution 3848 // when referred to from a potentially-evaluated expression. [Note: this 3849 // covers calls to named functions (5.2.2), operator overloading 3850 // (clause 13), user-defined conversions (12.3.2), allocation function for 3851 // placement new (5.3.4), as well as non-default initialization (8.5). 3852 if (Best->Function) 3853 MarkDeclarationReferenced(Loc, Best->Function); 3854 return OR_Success; 3855} 3856 3857/// PrintOverloadCandidates - When overload resolution fails, prints 3858/// diagnostic messages containing the candidates in the candidate 3859/// set. If OnlyViable is true, only viable candidates will be printed. 3860void 3861Sema::PrintOverloadCandidates(OverloadCandidateSet& CandidateSet, 3862 bool OnlyViable) { 3863 OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 3864 LastCand = CandidateSet.end(); 3865 for (; Cand != LastCand; ++Cand) { 3866 if (Cand->Viable || !OnlyViable) { 3867 if (Cand->Function) { 3868 if (Cand->Function->isDeleted() || 3869 Cand->Function->getAttr<UnavailableAttr>()) { 3870 // Deleted or "unavailable" function. 3871 Diag(Cand->Function->getLocation(), diag::err_ovl_candidate_deleted) 3872 << Cand->Function->isDeleted(); 3873 } else if (FunctionTemplateDecl *FunTmpl 3874 = Cand->Function->getPrimaryTemplate()) { 3875 // Function template specialization 3876 // FIXME: Give a better reason! 3877 Diag(Cand->Function->getLocation(), diag::err_ovl_template_candidate) 3878 << getTemplateArgumentBindingsText(FunTmpl->getTemplateParameters(), 3879 *Cand->Function->getTemplateSpecializationArgs()); 3880 } else { 3881 // Normal function 3882 bool errReported = false; 3883 if (!Cand->Viable && Cand->Conversions.size() > 0) { 3884 for (int i = Cand->Conversions.size()-1; i >= 0; i--) { 3885 const ImplicitConversionSequence &Conversion = 3886 Cand->Conversions[i]; 3887 if ((Conversion.ConversionKind != 3888 ImplicitConversionSequence::BadConversion) || 3889 Conversion.ConversionFunctionSet.size() == 0) 3890 continue; 3891 Diag(Cand->Function->getLocation(), 3892 diag::err_ovl_candidate_not_viable) << (i+1); 3893 errReported = true; 3894 for (int j = Conversion.ConversionFunctionSet.size()-1; 3895 j >= 0; j--) { 3896 FunctionDecl *Func = Conversion.ConversionFunctionSet[j]; 3897 Diag(Func->getLocation(), diag::err_ovl_candidate); 3898 } 3899 } 3900 } 3901 if (!errReported) 3902 Diag(Cand->Function->getLocation(), diag::err_ovl_candidate); 3903 } 3904 } else if (Cand->IsSurrogate) { 3905 // Desugar the type of the surrogate down to a function type, 3906 // retaining as many typedefs as possible while still showing 3907 // the function type (and, therefore, its parameter types). 3908 QualType FnType = Cand->Surrogate->getConversionType(); 3909 bool isLValueReference = false; 3910 bool isRValueReference = false; 3911 bool isPointer = false; 3912 if (const LValueReferenceType *FnTypeRef = 3913 FnType->getAs<LValueReferenceType>()) { 3914 FnType = FnTypeRef->getPointeeType(); 3915 isLValueReference = true; 3916 } else if (const RValueReferenceType *FnTypeRef = 3917 FnType->getAs<RValueReferenceType>()) { 3918 FnType = FnTypeRef->getPointeeType(); 3919 isRValueReference = true; 3920 } 3921 if (const PointerType *FnTypePtr = FnType->getAs<PointerType>()) { 3922 FnType = FnTypePtr->getPointeeType(); 3923 isPointer = true; 3924 } 3925 // Desugar down to a function type. 3926 FnType = QualType(FnType->getAs<FunctionType>(), 0); 3927 // Reconstruct the pointer/reference as appropriate. 3928 if (isPointer) FnType = Context.getPointerType(FnType); 3929 if (isRValueReference) FnType = Context.getRValueReferenceType(FnType); 3930 if (isLValueReference) FnType = Context.getLValueReferenceType(FnType); 3931 3932 Diag(Cand->Surrogate->getLocation(), diag::err_ovl_surrogate_cand) 3933 << FnType; 3934 } else { 3935 // FIXME: We need to get the identifier in here 3936 // FIXME: Do we want the error message to point at the operator? 3937 // (built-ins won't have a location) 3938 QualType FnType 3939 = Context.getFunctionType(Cand->BuiltinTypes.ResultTy, 3940 Cand->BuiltinTypes.ParamTypes, 3941 Cand->Conversions.size(), 3942 false, 0); 3943 3944 Diag(SourceLocation(), diag::err_ovl_builtin_candidate) << FnType; 3945 } 3946 } 3947 } 3948} 3949 3950/// ResolveAddressOfOverloadedFunction - Try to resolve the address of 3951/// an overloaded function (C++ [over.over]), where @p From is an 3952/// expression with overloaded function type and @p ToType is the type 3953/// we're trying to resolve to. For example: 3954/// 3955/// @code 3956/// int f(double); 3957/// int f(int); 3958/// 3959/// int (*pfd)(double) = f; // selects f(double) 3960/// @endcode 3961/// 3962/// This routine returns the resulting FunctionDecl if it could be 3963/// resolved, and NULL otherwise. When @p Complain is true, this 3964/// routine will emit diagnostics if there is an error. 3965FunctionDecl * 3966Sema::ResolveAddressOfOverloadedFunction(Expr *From, QualType ToType, 3967 bool Complain) { 3968 QualType FunctionType = ToType; 3969 bool IsMember = false; 3970 if (const PointerType *ToTypePtr = ToType->getAs<PointerType>()) 3971 FunctionType = ToTypePtr->getPointeeType(); 3972 else if (const ReferenceType *ToTypeRef = ToType->getAs<ReferenceType>()) 3973 FunctionType = ToTypeRef->getPointeeType(); 3974 else if (const MemberPointerType *MemTypePtr = 3975 ToType->getAs<MemberPointerType>()) { 3976 FunctionType = MemTypePtr->getPointeeType(); 3977 IsMember = true; 3978 } 3979 3980 // We only look at pointers or references to functions. 3981 FunctionType = Context.getCanonicalType(FunctionType).getUnqualifiedType(); 3982 if (!FunctionType->isFunctionType()) 3983 return 0; 3984 3985 // Find the actual overloaded function declaration. 3986 OverloadedFunctionDecl *Ovl = 0; 3987 3988 // C++ [over.over]p1: 3989 // [...] [Note: any redundant set of parentheses surrounding the 3990 // overloaded function name is ignored (5.1). ] 3991 Expr *OvlExpr = From->IgnoreParens(); 3992 3993 // C++ [over.over]p1: 3994 // [...] The overloaded function name can be preceded by the & 3995 // operator. 3996 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(OvlExpr)) { 3997 if (UnOp->getOpcode() == UnaryOperator::AddrOf) 3998 OvlExpr = UnOp->getSubExpr()->IgnoreParens(); 3999 } 4000 4001 // Try to dig out the overloaded function. 4002 FunctionTemplateDecl *FunctionTemplate = 0; 4003 if (DeclRefExpr *DR = dyn_cast<DeclRefExpr>(OvlExpr)) { 4004 Ovl = dyn_cast<OverloadedFunctionDecl>(DR->getDecl()); 4005 FunctionTemplate = dyn_cast<FunctionTemplateDecl>(DR->getDecl()); 4006 } 4007 4008 // If there's no overloaded function declaration or function template, 4009 // we're done. 4010 if (!Ovl && !FunctionTemplate) 4011 return 0; 4012 4013 OverloadIterator Fun; 4014 if (Ovl) 4015 Fun = Ovl; 4016 else 4017 Fun = FunctionTemplate; 4018 4019 // Look through all of the overloaded functions, searching for one 4020 // whose type matches exactly. 4021 llvm::SmallPtrSet<FunctionDecl *, 4> Matches; 4022 4023 bool FoundNonTemplateFunction = false; 4024 for (OverloadIterator FunEnd; Fun != FunEnd; ++Fun) { 4025 // C++ [over.over]p3: 4026 // Non-member functions and static member functions match 4027 // targets of type "pointer-to-function" or "reference-to-function." 4028 // Nonstatic member functions match targets of 4029 // type "pointer-to-member-function." 4030 // Note that according to DR 247, the containing class does not matter. 4031 4032 if (FunctionTemplateDecl *FunctionTemplate 4033 = dyn_cast<FunctionTemplateDecl>(*Fun)) { 4034 if (CXXMethodDecl *Method 4035 = dyn_cast<CXXMethodDecl>(FunctionTemplate->getTemplatedDecl())) { 4036 // Skip non-static function templates when converting to pointer, and 4037 // static when converting to member pointer. 4038 if (Method->isStatic() == IsMember) 4039 continue; 4040 } else if (IsMember) 4041 continue; 4042 4043 // C++ [over.over]p2: 4044 // If the name is a function template, template argument deduction is 4045 // done (14.8.2.2), and if the argument deduction succeeds, the 4046 // resulting template argument list is used to generate a single 4047 // function template specialization, which is added to the set of 4048 // overloaded functions considered. 4049 FunctionDecl *Specialization = 0; 4050 TemplateDeductionInfo Info(Context); 4051 if (TemplateDeductionResult Result 4052 = DeduceTemplateArguments(FunctionTemplate, /*FIXME*/false, 4053 /*FIXME:*/0, /*FIXME:*/0, 4054 FunctionType, Specialization, Info)) { 4055 // FIXME: make a note of the failed deduction for diagnostics. 4056 (void)Result; 4057 } else { 4058 assert(FunctionType 4059 == Context.getCanonicalType(Specialization->getType())); 4060 Matches.insert( 4061 cast<FunctionDecl>(Specialization->getCanonicalDecl())); 4062 } 4063 } 4064 4065 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(*Fun)) { 4066 // Skip non-static functions when converting to pointer, and static 4067 // when converting to member pointer. 4068 if (Method->isStatic() == IsMember) 4069 continue; 4070 } else if (IsMember) 4071 continue; 4072 4073 if (FunctionDecl *FunDecl = dyn_cast<FunctionDecl>(*Fun)) { 4074 if (FunctionType == Context.getCanonicalType(FunDecl->getType())) { 4075 Matches.insert(cast<FunctionDecl>(Fun->getCanonicalDecl())); 4076 FoundNonTemplateFunction = true; 4077 } 4078 } 4079 } 4080 4081 // If there were 0 or 1 matches, we're done. 4082 if (Matches.empty()) 4083 return 0; 4084 else if (Matches.size() == 1) 4085 return *Matches.begin(); 4086 4087 // C++ [over.over]p4: 4088 // If more than one function is selected, [...] 4089 llvm::SmallVector<FunctionDecl *, 4> RemainingMatches; 4090 typedef llvm::SmallPtrSet<FunctionDecl *, 4>::iterator MatchIter; 4091 if (FoundNonTemplateFunction) { 4092 // [...] any function template specializations in the set are 4093 // eliminated if the set also contains a non-template function, [...] 4094 for (MatchIter M = Matches.begin(), MEnd = Matches.end(); M != MEnd; ++M) 4095 if ((*M)->getPrimaryTemplate() == 0) 4096 RemainingMatches.push_back(*M); 4097 } else { 4098 // [...] and any given function template specialization F1 is 4099 // eliminated if the set contains a second function template 4100 // specialization whose function template is more specialized 4101 // than the function template of F1 according to the partial 4102 // ordering rules of 14.5.5.2. 4103 4104 // The algorithm specified above is quadratic. We instead use a 4105 // two-pass algorithm (similar to the one used to identify the 4106 // best viable function in an overload set) that identifies the 4107 // best function template (if it exists). 4108 MatchIter Best = Matches.begin(); 4109 MatchIter M = Best, MEnd = Matches.end(); 4110 // Find the most specialized function. 4111 for (++M; M != MEnd; ++M) 4112 if (getMoreSpecializedTemplate((*M)->getPrimaryTemplate(), 4113 (*Best)->getPrimaryTemplate(), 4114 TPOC_Other) 4115 == (*M)->getPrimaryTemplate()) 4116 Best = M; 4117 4118 // Determine whether this function template is more specialized 4119 // that all of the others. 4120 bool Ambiguous = false; 4121 for (M = Matches.begin(); M != MEnd; ++M) { 4122 if (M != Best && 4123 getMoreSpecializedTemplate((*M)->getPrimaryTemplate(), 4124 (*Best)->getPrimaryTemplate(), 4125 TPOC_Other) 4126 != (*Best)->getPrimaryTemplate()) { 4127 Ambiguous = true; 4128 break; 4129 } 4130 } 4131 4132 // If one function template was more specialized than all of the 4133 // others, return it. 4134 if (!Ambiguous) 4135 return *Best; 4136 4137 // We could not find a most-specialized function template, which 4138 // is equivalent to having a set of function templates with more 4139 // than one such template. So, we place all of the function 4140 // templates into the set of remaining matches and produce a 4141 // diagnostic below. FIXME: we could perform the quadratic 4142 // algorithm here, pruning the result set to limit the number of 4143 // candidates output later. 4144 RemainingMatches.append(Matches.begin(), Matches.end()); 4145 } 4146 4147 // [...] After such eliminations, if any, there shall remain exactly one 4148 // selected function. 4149 if (RemainingMatches.size() == 1) 4150 return RemainingMatches.front(); 4151 4152 // FIXME: We should probably return the same thing that BestViableFunction 4153 // returns (even if we issue the diagnostics here). 4154 Diag(From->getLocStart(), diag::err_addr_ovl_ambiguous) 4155 << RemainingMatches[0]->getDeclName(); 4156 for (unsigned I = 0, N = RemainingMatches.size(); I != N; ++I) 4157 Diag(RemainingMatches[I]->getLocation(), diag::err_ovl_candidate); 4158 return 0; 4159} 4160 4161/// \brief Add a single candidate to the overload set. 4162static void AddOverloadedCallCandidate(Sema &S, 4163 AnyFunctionDecl Callee, 4164 bool &ArgumentDependentLookup, 4165 bool HasExplicitTemplateArgs, 4166 const TemplateArgument *ExplicitTemplateArgs, 4167 unsigned NumExplicitTemplateArgs, 4168 Expr **Args, unsigned NumArgs, 4169 OverloadCandidateSet &CandidateSet, 4170 bool PartialOverloading) { 4171 if (FunctionDecl *Func = dyn_cast<FunctionDecl>(Callee)) { 4172 assert(!HasExplicitTemplateArgs && "Explicit template arguments?"); 4173 S.AddOverloadCandidate(Func, Args, NumArgs, CandidateSet, false, false, 4174 PartialOverloading); 4175 4176 if (Func->getDeclContext()->isRecord() || 4177 Func->getDeclContext()->isFunctionOrMethod()) 4178 ArgumentDependentLookup = false; 4179 return; 4180 } 4181 4182 FunctionTemplateDecl *FuncTemplate = cast<FunctionTemplateDecl>(Callee); 4183 S.AddTemplateOverloadCandidate(FuncTemplate, HasExplicitTemplateArgs, 4184 ExplicitTemplateArgs, 4185 NumExplicitTemplateArgs, 4186 Args, NumArgs, CandidateSet); 4187 4188 if (FuncTemplate->getDeclContext()->isRecord()) 4189 ArgumentDependentLookup = false; 4190} 4191 4192/// \brief Add the overload candidates named by callee and/or found by argument 4193/// dependent lookup to the given overload set. 4194void Sema::AddOverloadedCallCandidates(NamedDecl *Callee, 4195 DeclarationName &UnqualifiedName, 4196 bool &ArgumentDependentLookup, 4197 bool HasExplicitTemplateArgs, 4198 const TemplateArgument *ExplicitTemplateArgs, 4199 unsigned NumExplicitTemplateArgs, 4200 Expr **Args, unsigned NumArgs, 4201 OverloadCandidateSet &CandidateSet, 4202 bool PartialOverloading) { 4203 // Add the functions denoted by Callee to the set of candidate 4204 // functions. While we're doing so, track whether argument-dependent 4205 // lookup still applies, per: 4206 // 4207 // C++0x [basic.lookup.argdep]p3: 4208 // Let X be the lookup set produced by unqualified lookup (3.4.1) 4209 // and let Y be the lookup set produced by argument dependent 4210 // lookup (defined as follows). If X contains 4211 // 4212 // -- a declaration of a class member, or 4213 // 4214 // -- a block-scope function declaration that is not a 4215 // using-declaration (FIXME: check for using declaration), or 4216 // 4217 // -- a declaration that is neither a function or a function 4218 // template 4219 // 4220 // then Y is empty. 4221 if (!Callee) { 4222 // Nothing to do. 4223 } else if (OverloadedFunctionDecl *Ovl 4224 = dyn_cast<OverloadedFunctionDecl>(Callee)) { 4225 for (OverloadedFunctionDecl::function_iterator Func = Ovl->function_begin(), 4226 FuncEnd = Ovl->function_end(); 4227 Func != FuncEnd; ++Func) 4228 AddOverloadedCallCandidate(*this, *Func, ArgumentDependentLookup, 4229 HasExplicitTemplateArgs, 4230 ExplicitTemplateArgs, NumExplicitTemplateArgs, 4231 Args, NumArgs, CandidateSet, 4232 PartialOverloading); 4233 } else if (isa<FunctionDecl>(Callee) || isa<FunctionTemplateDecl>(Callee)) 4234 AddOverloadedCallCandidate(*this, 4235 AnyFunctionDecl::getFromNamedDecl(Callee), 4236 ArgumentDependentLookup, 4237 HasExplicitTemplateArgs, 4238 ExplicitTemplateArgs, NumExplicitTemplateArgs, 4239 Args, NumArgs, CandidateSet, 4240 PartialOverloading); 4241 // FIXME: assert isa<FunctionDecl> || isa<FunctionTemplateDecl> rather than 4242 // checking dynamically. 4243 4244 if (Callee) 4245 UnqualifiedName = Callee->getDeclName(); 4246 4247 if (ArgumentDependentLookup) 4248 AddArgumentDependentLookupCandidates(UnqualifiedName, Args, NumArgs, 4249 HasExplicitTemplateArgs, 4250 ExplicitTemplateArgs, 4251 NumExplicitTemplateArgs, 4252 CandidateSet, 4253 PartialOverloading); 4254} 4255 4256/// ResolveOverloadedCallFn - Given the call expression that calls Fn 4257/// (which eventually refers to the declaration Func) and the call 4258/// arguments Args/NumArgs, attempt to resolve the function call down 4259/// to a specific function. If overload resolution succeeds, returns 4260/// the function declaration produced by overload 4261/// resolution. Otherwise, emits diagnostics, deletes all of the 4262/// arguments and Fn, and returns NULL. 4263FunctionDecl *Sema::ResolveOverloadedCallFn(Expr *Fn, NamedDecl *Callee, 4264 DeclarationName UnqualifiedName, 4265 bool HasExplicitTemplateArgs, 4266 const TemplateArgument *ExplicitTemplateArgs, 4267 unsigned NumExplicitTemplateArgs, 4268 SourceLocation LParenLoc, 4269 Expr **Args, unsigned NumArgs, 4270 SourceLocation *CommaLocs, 4271 SourceLocation RParenLoc, 4272 bool &ArgumentDependentLookup) { 4273 OverloadCandidateSet CandidateSet; 4274 4275 // Add the functions denoted by Callee to the set of candidate 4276 // functions. 4277 AddOverloadedCallCandidates(Callee, UnqualifiedName, ArgumentDependentLookup, 4278 HasExplicitTemplateArgs, ExplicitTemplateArgs, 4279 NumExplicitTemplateArgs, Args, NumArgs, 4280 CandidateSet); 4281 OverloadCandidateSet::iterator Best; 4282 switch (BestViableFunction(CandidateSet, Fn->getLocStart(), Best)) { 4283 case OR_Success: 4284 return Best->Function; 4285 4286 case OR_No_Viable_Function: 4287 Diag(Fn->getSourceRange().getBegin(), 4288 diag::err_ovl_no_viable_function_in_call) 4289 << UnqualifiedName << Fn->getSourceRange(); 4290 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4291 break; 4292 4293 case OR_Ambiguous: 4294 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_ambiguous_call) 4295 << UnqualifiedName << Fn->getSourceRange(); 4296 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4297 break; 4298 4299 case OR_Deleted: 4300 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_deleted_call) 4301 << Best->Function->isDeleted() 4302 << UnqualifiedName 4303 << Fn->getSourceRange(); 4304 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4305 break; 4306 } 4307 4308 // Overload resolution failed. Destroy all of the subexpressions and 4309 // return NULL. 4310 Fn->Destroy(Context); 4311 for (unsigned Arg = 0; Arg < NumArgs; ++Arg) 4312 Args[Arg]->Destroy(Context); 4313 return 0; 4314} 4315 4316/// \brief Create a unary operation that may resolve to an overloaded 4317/// operator. 4318/// 4319/// \param OpLoc The location of the operator itself (e.g., '*'). 4320/// 4321/// \param OpcIn The UnaryOperator::Opcode that describes this 4322/// operator. 4323/// 4324/// \param Functions The set of non-member functions that will be 4325/// considered by overload resolution. The caller needs to build this 4326/// set based on the context using, e.g., 4327/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 4328/// set should not contain any member functions; those will be added 4329/// by CreateOverloadedUnaryOp(). 4330/// 4331/// \param input The input argument. 4332Sema::OwningExprResult Sema::CreateOverloadedUnaryOp(SourceLocation OpLoc, 4333 unsigned OpcIn, 4334 FunctionSet &Functions, 4335 ExprArg input) { 4336 UnaryOperator::Opcode Opc = static_cast<UnaryOperator::Opcode>(OpcIn); 4337 Expr *Input = (Expr *)input.get(); 4338 4339 OverloadedOperatorKind Op = UnaryOperator::getOverloadedOperator(Opc); 4340 assert(Op != OO_None && "Invalid opcode for overloaded unary operator"); 4341 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 4342 4343 Expr *Args[2] = { Input, 0 }; 4344 unsigned NumArgs = 1; 4345 4346 // For post-increment and post-decrement, add the implicit '0' as 4347 // the second argument, so that we know this is a post-increment or 4348 // post-decrement. 4349 if (Opc == UnaryOperator::PostInc || Opc == UnaryOperator::PostDec) { 4350 llvm::APSInt Zero(Context.getTypeSize(Context.IntTy), false); 4351 Args[1] = new (Context) IntegerLiteral(Zero, Context.IntTy, 4352 SourceLocation()); 4353 NumArgs = 2; 4354 } 4355 4356 if (Input->isTypeDependent()) { 4357 OverloadedFunctionDecl *Overloads 4358 = OverloadedFunctionDecl::Create(Context, CurContext, OpName); 4359 for (FunctionSet::iterator Func = Functions.begin(), 4360 FuncEnd = Functions.end(); 4361 Func != FuncEnd; ++Func) 4362 Overloads->addOverload(*Func); 4363 4364 DeclRefExpr *Fn = new (Context) DeclRefExpr(Overloads, Context.OverloadTy, 4365 OpLoc, false, false); 4366 4367 input.release(); 4368 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 4369 &Args[0], NumArgs, 4370 Context.DependentTy, 4371 OpLoc)); 4372 } 4373 4374 // Build an empty overload set. 4375 OverloadCandidateSet CandidateSet; 4376 4377 // Add the candidates from the given function set. 4378 AddFunctionCandidates(Functions, &Args[0], NumArgs, CandidateSet, false); 4379 4380 // Add operator candidates that are member functions. 4381 AddMemberOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 4382 4383 // Add builtin operator candidates. 4384 AddBuiltinOperatorCandidates(Op, &Args[0], NumArgs, CandidateSet); 4385 4386 // Perform overload resolution. 4387 OverloadCandidateSet::iterator Best; 4388 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 4389 case OR_Success: { 4390 // We found a built-in operator or an overloaded operator. 4391 FunctionDecl *FnDecl = Best->Function; 4392 4393 if (FnDecl) { 4394 // We matched an overloaded operator. Build a call to that 4395 // operator. 4396 4397 // Convert the arguments. 4398 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 4399 if (PerformObjectArgumentInitialization(Input, Method)) 4400 return ExprError(); 4401 } else { 4402 // Convert the arguments. 4403 if (PerformCopyInitialization(Input, 4404 FnDecl->getParamDecl(0)->getType(), 4405 "passing")) 4406 return ExprError(); 4407 } 4408 4409 // Determine the result type 4410 QualType ResultTy 4411 = FnDecl->getType()->getAs<FunctionType>()->getResultType(); 4412 ResultTy = ResultTy.getNonReferenceType(); 4413 4414 // Build the actual expression node. 4415 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 4416 SourceLocation()); 4417 UsualUnaryConversions(FnExpr); 4418 4419 input.release(); 4420 4421 Expr *CE = new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 4422 &Input, 1, ResultTy, OpLoc); 4423 return MaybeBindToTemporary(CE); 4424 } else { 4425 // We matched a built-in operator. Convert the arguments, then 4426 // break out so that we will build the appropriate built-in 4427 // operator node. 4428 if (PerformImplicitConversion(Input, Best->BuiltinTypes.ParamTypes[0], 4429 Best->Conversions[0], "passing")) 4430 return ExprError(); 4431 4432 break; 4433 } 4434 } 4435 4436 case OR_No_Viable_Function: 4437 // No viable function; fall through to handling this as a 4438 // built-in operator, which will produce an error message for us. 4439 break; 4440 4441 case OR_Ambiguous: 4442 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 4443 << UnaryOperator::getOpcodeStr(Opc) 4444 << Input->getSourceRange(); 4445 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4446 return ExprError(); 4447 4448 case OR_Deleted: 4449 Diag(OpLoc, diag::err_ovl_deleted_oper) 4450 << Best->Function->isDeleted() 4451 << UnaryOperator::getOpcodeStr(Opc) 4452 << Input->getSourceRange(); 4453 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4454 return ExprError(); 4455 } 4456 4457 // Either we found no viable overloaded operator or we matched a 4458 // built-in operator. In either case, fall through to trying to 4459 // build a built-in operation. 4460 input.release(); 4461 return CreateBuiltinUnaryOp(OpLoc, Opc, Owned(Input)); 4462} 4463 4464/// \brief Create a binary operation that may resolve to an overloaded 4465/// operator. 4466/// 4467/// \param OpLoc The location of the operator itself (e.g., '+'). 4468/// 4469/// \param OpcIn The BinaryOperator::Opcode that describes this 4470/// operator. 4471/// 4472/// \param Functions The set of non-member functions that will be 4473/// considered by overload resolution. The caller needs to build this 4474/// set based on the context using, e.g., 4475/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 4476/// set should not contain any member functions; those will be added 4477/// by CreateOverloadedBinOp(). 4478/// 4479/// \param LHS Left-hand argument. 4480/// \param RHS Right-hand argument. 4481Sema::OwningExprResult 4482Sema::CreateOverloadedBinOp(SourceLocation OpLoc, 4483 unsigned OpcIn, 4484 FunctionSet &Functions, 4485 Expr *LHS, Expr *RHS) { 4486 Expr *Args[2] = { LHS, RHS }; 4487 LHS=RHS=0; //Please use only Args instead of LHS/RHS couple 4488 4489 BinaryOperator::Opcode Opc = static_cast<BinaryOperator::Opcode>(OpcIn); 4490 OverloadedOperatorKind Op = BinaryOperator::getOverloadedOperator(Opc); 4491 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 4492 4493 // If either side is type-dependent, create an appropriate dependent 4494 // expression. 4495 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 4496 // .* cannot be overloaded. 4497 if (Opc == BinaryOperator::PtrMemD) 4498 return Owned(new (Context) BinaryOperator(Args[0], Args[1], Opc, 4499 Context.DependentTy, OpLoc)); 4500 4501 OverloadedFunctionDecl *Overloads 4502 = OverloadedFunctionDecl::Create(Context, CurContext, OpName); 4503 for (FunctionSet::iterator Func = Functions.begin(), 4504 FuncEnd = Functions.end(); 4505 Func != FuncEnd; ++Func) 4506 Overloads->addOverload(*Func); 4507 4508 DeclRefExpr *Fn = new (Context) DeclRefExpr(Overloads, Context.OverloadTy, 4509 OpLoc, false, false); 4510 4511 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 4512 Args, 2, 4513 Context.DependentTy, 4514 OpLoc)); 4515 } 4516 4517 // If this is the .* operator, which is not overloadable, just 4518 // create a built-in binary operator. 4519 if (Opc == BinaryOperator::PtrMemD) 4520 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 4521 4522 // If this is one of the assignment operators, we only perform 4523 // overload resolution if the left-hand side is a class or 4524 // enumeration type (C++ [expr.ass]p3). 4525 if (Opc >= BinaryOperator::Assign && Opc <= BinaryOperator::OrAssign && 4526 !Args[0]->getType()->isOverloadableType()) 4527 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 4528 4529 // Build an empty overload set. 4530 OverloadCandidateSet CandidateSet; 4531 4532 // Add the candidates from the given function set. 4533 AddFunctionCandidates(Functions, Args, 2, CandidateSet, false); 4534 4535 // Add operator candidates that are member functions. 4536 AddMemberOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 4537 4538 // Add builtin operator candidates. 4539 AddBuiltinOperatorCandidates(Op, Args, 2, CandidateSet); 4540 4541 // Perform overload resolution. 4542 OverloadCandidateSet::iterator Best; 4543 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 4544 case OR_Success: { 4545 // We found a built-in operator or an overloaded operator. 4546 FunctionDecl *FnDecl = Best->Function; 4547 4548 if (FnDecl) { 4549 // We matched an overloaded operator. Build a call to that 4550 // operator. 4551 4552 // Convert the arguments. 4553 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 4554 if (PerformObjectArgumentInitialization(Args[0], Method) || 4555 PerformCopyInitialization(Args[1], FnDecl->getParamDecl(0)->getType(), 4556 "passing")) 4557 return ExprError(); 4558 } else { 4559 // Convert the arguments. 4560 if (PerformCopyInitialization(Args[0], FnDecl->getParamDecl(0)->getType(), 4561 "passing") || 4562 PerformCopyInitialization(Args[1], FnDecl->getParamDecl(1)->getType(), 4563 "passing")) 4564 return ExprError(); 4565 } 4566 4567 // Determine the result type 4568 QualType ResultTy 4569 = FnDecl->getType()->getAs<FunctionType>()->getResultType(); 4570 ResultTy = ResultTy.getNonReferenceType(); 4571 4572 // Build the actual expression node. 4573 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 4574 OpLoc); 4575 UsualUnaryConversions(FnExpr); 4576 4577 Expr *CE = new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 4578 Args, 2, ResultTy, OpLoc); 4579 return MaybeBindToTemporary(CE); 4580 } else { 4581 // We matched a built-in operator. Convert the arguments, then 4582 // break out so that we will build the appropriate built-in 4583 // operator node. 4584 if (PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 4585 Best->Conversions[0], "passing") || 4586 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 4587 Best->Conversions[1], "passing")) 4588 return ExprError(); 4589 4590 break; 4591 } 4592 } 4593 4594 case OR_No_Viable_Function: 4595 // For class as left operand for assignment or compound assigment operator 4596 // do not fall through to handling in built-in, but report that no overloaded 4597 // assignment operator found 4598 if (Args[0]->getType()->isRecordType() && Opc >= BinaryOperator::Assign && Opc <= BinaryOperator::OrAssign) { 4599 Diag(OpLoc, diag::err_ovl_no_viable_oper) 4600 << BinaryOperator::getOpcodeStr(Opc) 4601 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 4602 return ExprError(); 4603 } 4604 // No viable function; fall through to handling this as a 4605 // built-in operator, which will produce an error message for us. 4606 break; 4607 4608 case OR_Ambiguous: 4609 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 4610 << BinaryOperator::getOpcodeStr(Opc) 4611 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 4612 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4613 return ExprError(); 4614 4615 case OR_Deleted: 4616 Diag(OpLoc, diag::err_ovl_deleted_oper) 4617 << Best->Function->isDeleted() 4618 << BinaryOperator::getOpcodeStr(Opc) 4619 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 4620 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4621 return ExprError(); 4622 } 4623 4624 // Either we found no viable overloaded operator or we matched a 4625 // built-in operator. In either case, try to build a built-in 4626 // operation. 4627 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 4628} 4629 4630/// BuildCallToMemberFunction - Build a call to a member 4631/// function. MemExpr is the expression that refers to the member 4632/// function (and includes the object parameter), Args/NumArgs are the 4633/// arguments to the function call (not including the object 4634/// parameter). The caller needs to validate that the member 4635/// expression refers to a member function or an overloaded member 4636/// function. 4637Sema::ExprResult 4638Sema::BuildCallToMemberFunction(Scope *S, Expr *MemExprE, 4639 SourceLocation LParenLoc, Expr **Args, 4640 unsigned NumArgs, SourceLocation *CommaLocs, 4641 SourceLocation RParenLoc) { 4642 // Dig out the member expression. This holds both the object 4643 // argument and the member function we're referring to. 4644 MemberExpr *MemExpr = 0; 4645 if (ParenExpr *ParenE = dyn_cast<ParenExpr>(MemExprE)) 4646 MemExpr = dyn_cast<MemberExpr>(ParenE->getSubExpr()); 4647 else 4648 MemExpr = dyn_cast<MemberExpr>(MemExprE); 4649 assert(MemExpr && "Building member call without member expression"); 4650 4651 // Extract the object argument. 4652 Expr *ObjectArg = MemExpr->getBase(); 4653 4654 CXXMethodDecl *Method = 0; 4655 if (isa<OverloadedFunctionDecl>(MemExpr->getMemberDecl()) || 4656 isa<FunctionTemplateDecl>(MemExpr->getMemberDecl())) { 4657 // Add overload candidates 4658 OverloadCandidateSet CandidateSet; 4659 DeclarationName DeclName = MemExpr->getMemberDecl()->getDeclName(); 4660 4661 for (OverloadIterator Func(MemExpr->getMemberDecl()), FuncEnd; 4662 Func != FuncEnd; ++Func) { 4663 if ((Method = dyn_cast<CXXMethodDecl>(*Func))) 4664 AddMethodCandidate(Method, ObjectArg, Args, NumArgs, CandidateSet, 4665 /*SuppressUserConversions=*/false); 4666 else 4667 AddMethodTemplateCandidate(cast<FunctionTemplateDecl>(*Func), 4668 MemExpr->hasExplicitTemplateArgumentList(), 4669 MemExpr->getTemplateArgs(), 4670 MemExpr->getNumTemplateArgs(), 4671 ObjectArg, Args, NumArgs, 4672 CandidateSet, 4673 /*SuppressUsedConversions=*/false); 4674 } 4675 4676 OverloadCandidateSet::iterator Best; 4677 switch (BestViableFunction(CandidateSet, MemExpr->getLocStart(), Best)) { 4678 case OR_Success: 4679 Method = cast<CXXMethodDecl>(Best->Function); 4680 break; 4681 4682 case OR_No_Viable_Function: 4683 Diag(MemExpr->getSourceRange().getBegin(), 4684 diag::err_ovl_no_viable_member_function_in_call) 4685 << DeclName << MemExprE->getSourceRange(); 4686 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4687 // FIXME: Leaking incoming expressions! 4688 return true; 4689 4690 case OR_Ambiguous: 4691 Diag(MemExpr->getSourceRange().getBegin(), 4692 diag::err_ovl_ambiguous_member_call) 4693 << DeclName << MemExprE->getSourceRange(); 4694 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4695 // FIXME: Leaking incoming expressions! 4696 return true; 4697 4698 case OR_Deleted: 4699 Diag(MemExpr->getSourceRange().getBegin(), 4700 diag::err_ovl_deleted_member_call) 4701 << Best->Function->isDeleted() 4702 << DeclName << MemExprE->getSourceRange(); 4703 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4704 // FIXME: Leaking incoming expressions! 4705 return true; 4706 } 4707 4708 FixOverloadedFunctionReference(MemExpr, Method); 4709 } else { 4710 Method = dyn_cast<CXXMethodDecl>(MemExpr->getMemberDecl()); 4711 } 4712 4713 assert(Method && "Member call to something that isn't a method?"); 4714 ExprOwningPtr<CXXMemberCallExpr> 4715 TheCall(this, new (Context) CXXMemberCallExpr(Context, MemExpr, Args, 4716 NumArgs, 4717 Method->getResultType().getNonReferenceType(), 4718 RParenLoc)); 4719 4720 // Convert the object argument (for a non-static member function call). 4721 if (!Method->isStatic() && 4722 PerformObjectArgumentInitialization(ObjectArg, Method)) 4723 return true; 4724 MemExpr->setBase(ObjectArg); 4725 4726 // Convert the rest of the arguments 4727 const FunctionProtoType *Proto = cast<FunctionProtoType>(Method->getType()); 4728 if (ConvertArgumentsForCall(&*TheCall, MemExpr, Method, Proto, Args, NumArgs, 4729 RParenLoc)) 4730 return true; 4731 4732 if (CheckFunctionCall(Method, TheCall.get())) 4733 return true; 4734 4735 return MaybeBindToTemporary(TheCall.release()).release(); 4736} 4737 4738/// BuildCallToObjectOfClassType - Build a call to an object of class 4739/// type (C++ [over.call.object]), which can end up invoking an 4740/// overloaded function call operator (@c operator()) or performing a 4741/// user-defined conversion on the object argument. 4742Sema::ExprResult 4743Sema::BuildCallToObjectOfClassType(Scope *S, Expr *Object, 4744 SourceLocation LParenLoc, 4745 Expr **Args, unsigned NumArgs, 4746 SourceLocation *CommaLocs, 4747 SourceLocation RParenLoc) { 4748 assert(Object->getType()->isRecordType() && "Requires object type argument"); 4749 const RecordType *Record = Object->getType()->getAs<RecordType>(); 4750 4751 // C++ [over.call.object]p1: 4752 // If the primary-expression E in the function call syntax 4753 // evaluates to a class object of type "cv T", then the set of 4754 // candidate functions includes at least the function call 4755 // operators of T. The function call operators of T are obtained by 4756 // ordinary lookup of the name operator() in the context of 4757 // (E).operator(). 4758 OverloadCandidateSet CandidateSet; 4759 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Call); 4760 DeclContext::lookup_const_iterator Oper, OperEnd; 4761 for (llvm::tie(Oper, OperEnd) = Record->getDecl()->lookup(OpName); 4762 Oper != OperEnd; ++Oper) 4763 AddMethodCandidate(cast<CXXMethodDecl>(*Oper), Object, Args, NumArgs, 4764 CandidateSet, /*SuppressUserConversions=*/false); 4765 4766 // C++ [over.call.object]p2: 4767 // In addition, for each conversion function declared in T of the 4768 // form 4769 // 4770 // operator conversion-type-id () cv-qualifier; 4771 // 4772 // where cv-qualifier is the same cv-qualification as, or a 4773 // greater cv-qualification than, cv, and where conversion-type-id 4774 // denotes the type "pointer to function of (P1,...,Pn) returning 4775 // R", or the type "reference to pointer to function of 4776 // (P1,...,Pn) returning R", or the type "reference to function 4777 // of (P1,...,Pn) returning R", a surrogate call function [...] 4778 // is also considered as a candidate function. Similarly, 4779 // surrogate call functions are added to the set of candidate 4780 // functions for each conversion function declared in an 4781 // accessible base class provided the function is not hidden 4782 // within T by another intervening declaration. 4783 4784 if (!RequireCompleteType(SourceLocation(), Object->getType(), 0)) { 4785 // FIXME: Look in base classes for more conversion operators! 4786 OverloadedFunctionDecl *Conversions 4787 = cast<CXXRecordDecl>(Record->getDecl())->getConversionFunctions(); 4788 for (OverloadedFunctionDecl::function_iterator 4789 Func = Conversions->function_begin(), 4790 FuncEnd = Conversions->function_end(); 4791 Func != FuncEnd; ++Func) { 4792 CXXConversionDecl *Conv; 4793 FunctionTemplateDecl *ConvTemplate; 4794 GetFunctionAndTemplate(*Func, Conv, ConvTemplate); 4795 4796 // Skip over templated conversion functions; they aren't 4797 // surrogates. 4798 if (ConvTemplate) 4799 continue; 4800 4801 // Strip the reference type (if any) and then the pointer type (if 4802 // any) to get down to what might be a function type. 4803 QualType ConvType = Conv->getConversionType().getNonReferenceType(); 4804 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 4805 ConvType = ConvPtrType->getPointeeType(); 4806 4807 if (const FunctionProtoType *Proto = ConvType->getAs<FunctionProtoType>()) 4808 AddSurrogateCandidate(Conv, Proto, Object, Args, NumArgs, CandidateSet); 4809 } 4810 } 4811 4812 // Perform overload resolution. 4813 OverloadCandidateSet::iterator Best; 4814 switch (BestViableFunction(CandidateSet, Object->getLocStart(), Best)) { 4815 case OR_Success: 4816 // Overload resolution succeeded; we'll build the appropriate call 4817 // below. 4818 break; 4819 4820 case OR_No_Viable_Function: 4821 Diag(Object->getSourceRange().getBegin(), 4822 diag::err_ovl_no_viable_object_call) 4823 << Object->getType() << Object->getSourceRange(); 4824 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4825 break; 4826 4827 case OR_Ambiguous: 4828 Diag(Object->getSourceRange().getBegin(), 4829 diag::err_ovl_ambiguous_object_call) 4830 << Object->getType() << Object->getSourceRange(); 4831 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4832 break; 4833 4834 case OR_Deleted: 4835 Diag(Object->getSourceRange().getBegin(), 4836 diag::err_ovl_deleted_object_call) 4837 << Best->Function->isDeleted() 4838 << Object->getType() << Object->getSourceRange(); 4839 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4840 break; 4841 } 4842 4843 if (Best == CandidateSet.end()) { 4844 // We had an error; delete all of the subexpressions and return 4845 // the error. 4846 Object->Destroy(Context); 4847 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 4848 Args[ArgIdx]->Destroy(Context); 4849 return true; 4850 } 4851 4852 if (Best->Function == 0) { 4853 // Since there is no function declaration, this is one of the 4854 // surrogate candidates. Dig out the conversion function. 4855 CXXConversionDecl *Conv 4856 = cast<CXXConversionDecl>( 4857 Best->Conversions[0].UserDefined.ConversionFunction); 4858 4859 // We selected one of the surrogate functions that converts the 4860 // object parameter to a function pointer. Perform the conversion 4861 // on the object argument, then let ActOnCallExpr finish the job. 4862 // FIXME: Represent the user-defined conversion in the AST! 4863 ImpCastExprToType(Object, 4864 Conv->getConversionType().getNonReferenceType(), 4865 CastExpr::CK_Unknown, 4866 Conv->getConversionType()->isLValueReferenceType()); 4867 return ActOnCallExpr(S, ExprArg(*this, Object), LParenLoc, 4868 MultiExprArg(*this, (ExprTy**)Args, NumArgs), 4869 CommaLocs, RParenLoc).release(); 4870 } 4871 4872 // We found an overloaded operator(). Build a CXXOperatorCallExpr 4873 // that calls this method, using Object for the implicit object 4874 // parameter and passing along the remaining arguments. 4875 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 4876 const FunctionProtoType *Proto = Method->getType()->getAs<FunctionProtoType>(); 4877 4878 unsigned NumArgsInProto = Proto->getNumArgs(); 4879 unsigned NumArgsToCheck = NumArgs; 4880 4881 // Build the full argument list for the method call (the 4882 // implicit object parameter is placed at the beginning of the 4883 // list). 4884 Expr **MethodArgs; 4885 if (NumArgs < NumArgsInProto) { 4886 NumArgsToCheck = NumArgsInProto; 4887 MethodArgs = new Expr*[NumArgsInProto + 1]; 4888 } else { 4889 MethodArgs = new Expr*[NumArgs + 1]; 4890 } 4891 MethodArgs[0] = Object; 4892 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 4893 MethodArgs[ArgIdx + 1] = Args[ArgIdx]; 4894 4895 Expr *NewFn = new (Context) DeclRefExpr(Method, Method->getType(), 4896 SourceLocation()); 4897 UsualUnaryConversions(NewFn); 4898 4899 // Once we've built TheCall, all of the expressions are properly 4900 // owned. 4901 QualType ResultTy = Method->getResultType().getNonReferenceType(); 4902 ExprOwningPtr<CXXOperatorCallExpr> 4903 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Call, NewFn, 4904 MethodArgs, NumArgs + 1, 4905 ResultTy, RParenLoc)); 4906 delete [] MethodArgs; 4907 4908 // We may have default arguments. If so, we need to allocate more 4909 // slots in the call for them. 4910 if (NumArgs < NumArgsInProto) 4911 TheCall->setNumArgs(Context, NumArgsInProto + 1); 4912 else if (NumArgs > NumArgsInProto) 4913 NumArgsToCheck = NumArgsInProto; 4914 4915 bool IsError = false; 4916 4917 // Initialize the implicit object parameter. 4918 IsError |= PerformObjectArgumentInitialization(Object, Method); 4919 TheCall->setArg(0, Object); 4920 4921 4922 // Check the argument types. 4923 for (unsigned i = 0; i != NumArgsToCheck; i++) { 4924 Expr *Arg; 4925 if (i < NumArgs) { 4926 Arg = Args[i]; 4927 4928 // Pass the argument. 4929 QualType ProtoArgType = Proto->getArgType(i); 4930 IsError |= PerformCopyInitialization(Arg, ProtoArgType, "passing"); 4931 } else { 4932 Arg = CXXDefaultArgExpr::Create(Context, Method->getParamDecl(i)); 4933 } 4934 4935 TheCall->setArg(i + 1, Arg); 4936 } 4937 4938 // If this is a variadic call, handle args passed through "...". 4939 if (Proto->isVariadic()) { 4940 // Promote the arguments (C99 6.5.2.2p7). 4941 for (unsigned i = NumArgsInProto; i != NumArgs; i++) { 4942 Expr *Arg = Args[i]; 4943 IsError |= DefaultVariadicArgumentPromotion(Arg, VariadicMethod); 4944 TheCall->setArg(i + 1, Arg); 4945 } 4946 } 4947 4948 if (IsError) return true; 4949 4950 if (CheckFunctionCall(Method, TheCall.get())) 4951 return true; 4952 4953 return MaybeBindToTemporary(TheCall.release()).release(); 4954} 4955 4956/// BuildOverloadedArrowExpr - Build a call to an overloaded @c operator-> 4957/// (if one exists), where @c Base is an expression of class type and 4958/// @c Member is the name of the member we're trying to find. 4959Sema::OwningExprResult 4960Sema::BuildOverloadedArrowExpr(Scope *S, ExprArg BaseIn, SourceLocation OpLoc) { 4961 Expr *Base = static_cast<Expr *>(BaseIn.get()); 4962 assert(Base->getType()->isRecordType() && "left-hand side must have class type"); 4963 4964 // C++ [over.ref]p1: 4965 // 4966 // [...] An expression x->m is interpreted as (x.operator->())->m 4967 // for a class object x of type T if T::operator->() exists and if 4968 // the operator is selected as the best match function by the 4969 // overload resolution mechanism (13.3). 4970 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Arrow); 4971 OverloadCandidateSet CandidateSet; 4972 const RecordType *BaseRecord = Base->getType()->getAs<RecordType>(); 4973 4974 LookupResult R = LookupQualifiedName(BaseRecord->getDecl(), OpName, 4975 LookupOrdinaryName); 4976 4977 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 4978 Oper != OperEnd; ++Oper) 4979 AddMethodCandidate(cast<CXXMethodDecl>(*Oper), Base, 0, 0, CandidateSet, 4980 /*SuppressUserConversions=*/false); 4981 4982 // Perform overload resolution. 4983 OverloadCandidateSet::iterator Best; 4984 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 4985 case OR_Success: 4986 // Overload resolution succeeded; we'll build the call below. 4987 break; 4988 4989 case OR_No_Viable_Function: 4990 if (CandidateSet.empty()) 4991 Diag(OpLoc, diag::err_typecheck_member_reference_arrow) 4992 << Base->getType() << Base->getSourceRange(); 4993 else 4994 Diag(OpLoc, diag::err_ovl_no_viable_oper) 4995 << "operator->" << Base->getSourceRange(); 4996 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4997 return ExprError(); 4998 4999 case OR_Ambiguous: 5000 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 5001 << "->" << Base->getSourceRange(); 5002 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 5003 return ExprError(); 5004 5005 case OR_Deleted: 5006 Diag(OpLoc, diag::err_ovl_deleted_oper) 5007 << Best->Function->isDeleted() 5008 << "->" << Base->getSourceRange(); 5009 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 5010 return ExprError(); 5011 } 5012 5013 // Convert the object parameter. 5014 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 5015 if (PerformObjectArgumentInitialization(Base, Method)) 5016 return ExprError(); 5017 5018 // No concerns about early exits now. 5019 BaseIn.release(); 5020 5021 // Build the operator call. 5022 Expr *FnExpr = new (Context) DeclRefExpr(Method, Method->getType(), 5023 SourceLocation()); 5024 UsualUnaryConversions(FnExpr); 5025 Base = new (Context) CXXOperatorCallExpr(Context, OO_Arrow, FnExpr, &Base, 1, 5026 Method->getResultType().getNonReferenceType(), 5027 OpLoc); 5028 return Owned(Base); 5029} 5030 5031/// FixOverloadedFunctionReference - E is an expression that refers to 5032/// a C++ overloaded function (possibly with some parentheses and 5033/// perhaps a '&' around it). We have resolved the overloaded function 5034/// to the function declaration Fn, so patch up the expression E to 5035/// refer (possibly indirectly) to Fn. 5036void Sema::FixOverloadedFunctionReference(Expr *E, FunctionDecl *Fn) { 5037 if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) { 5038 FixOverloadedFunctionReference(PE->getSubExpr(), Fn); 5039 E->setType(PE->getSubExpr()->getType()); 5040 } else if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(E)) { 5041 assert(UnOp->getOpcode() == UnaryOperator::AddrOf && 5042 "Can only take the address of an overloaded function"); 5043 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 5044 if (Method->isStatic()) { 5045 // Do nothing: static member functions aren't any different 5046 // from non-member functions. 5047 } else if (QualifiedDeclRefExpr *DRE 5048 = dyn_cast<QualifiedDeclRefExpr>(UnOp->getSubExpr())) { 5049 // We have taken the address of a pointer to member 5050 // function. Perform the computation here so that we get the 5051 // appropriate pointer to member type. 5052 DRE->setDecl(Fn); 5053 DRE->setType(Fn->getType()); 5054 QualType ClassType 5055 = Context.getTypeDeclType(cast<RecordDecl>(Method->getDeclContext())); 5056 E->setType(Context.getMemberPointerType(Fn->getType(), 5057 ClassType.getTypePtr())); 5058 return; 5059 } 5060 } 5061 FixOverloadedFunctionReference(UnOp->getSubExpr(), Fn); 5062 E->setType(Context.getPointerType(UnOp->getSubExpr()->getType())); 5063 } else if (DeclRefExpr *DR = dyn_cast<DeclRefExpr>(E)) { 5064 assert((isa<OverloadedFunctionDecl>(DR->getDecl()) || 5065 isa<FunctionTemplateDecl>(DR->getDecl())) && 5066 "Expected overloaded function or function template"); 5067 DR->setDecl(Fn); 5068 E->setType(Fn->getType()); 5069 } else if (MemberExpr *MemExpr = dyn_cast<MemberExpr>(E)) { 5070 MemExpr->setMemberDecl(Fn); 5071 E->setType(Fn->getType()); 5072 } else { 5073 assert(false && "Invalid reference to overloaded function"); 5074 } 5075} 5076 5077} // end namespace clang 5078