SemaOverload.cpp revision f8c3ad7653697ae91634bda56cb0e3d6eac2ef45
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. 407/// If @p UserCast, the implicit conversion is being done for a user-specified 408/// cast. 409ImplicitConversionSequence 410Sema::TryImplicitConversion(Expr* From, QualType ToType, 411 bool SuppressUserConversions, 412 bool AllowExplicit, bool ForceRValue, 413 bool InOverloadResolution, 414 bool UserCast) { 415 ImplicitConversionSequence ICS; 416 OverloadCandidateSet Conversions; 417 OverloadingResult UserDefResult = OR_Success; 418 if (IsStandardConversion(From, ToType, InOverloadResolution, ICS.Standard)) 419 ICS.ConversionKind = ImplicitConversionSequence::StandardConversion; 420 else if (getLangOptions().CPlusPlus && 421 (UserDefResult = IsUserDefinedConversion(From, ToType, 422 ICS.UserDefined, 423 Conversions, 424 !SuppressUserConversions, AllowExplicit, 425 ForceRValue, UserCast)) == OR_Success) { 426 ICS.ConversionKind = ImplicitConversionSequence::UserDefinedConversion; 427 // C++ [over.ics.user]p4: 428 // A conversion of an expression of class type to the same class 429 // type is given Exact Match rank, and a conversion of an 430 // expression of class type to a base class of that type is 431 // given Conversion rank, in spite of the fact that a copy 432 // constructor (i.e., a user-defined conversion function) is 433 // called for those cases. 434 if (CXXConstructorDecl *Constructor 435 = dyn_cast<CXXConstructorDecl>(ICS.UserDefined.ConversionFunction)) { 436 QualType FromCanon 437 = Context.getCanonicalType(From->getType().getUnqualifiedType()); 438 QualType ToCanon = Context.getCanonicalType(ToType).getUnqualifiedType(); 439 if (FromCanon == ToCanon || IsDerivedFrom(FromCanon, ToCanon)) { 440 // Turn this into a "standard" conversion sequence, so that it 441 // gets ranked with standard conversion sequences. 442 ICS.ConversionKind = ImplicitConversionSequence::StandardConversion; 443 ICS.Standard.setAsIdentityConversion(); 444 ICS.Standard.FromTypePtr = From->getType().getAsOpaquePtr(); 445 ICS.Standard.ToTypePtr = ToType.getAsOpaquePtr(); 446 ICS.Standard.CopyConstructor = Constructor; 447 if (ToCanon != FromCanon) 448 ICS.Standard.Second = ICK_Derived_To_Base; 449 } 450 } 451 452 // C++ [over.best.ics]p4: 453 // However, when considering the argument of a user-defined 454 // conversion function that is a candidate by 13.3.1.3 when 455 // invoked for the copying of the temporary in the second step 456 // of a class copy-initialization, or by 13.3.1.4, 13.3.1.5, or 457 // 13.3.1.6 in all cases, only standard conversion sequences and 458 // ellipsis conversion sequences are allowed. 459 if (SuppressUserConversions && 460 ICS.ConversionKind == ImplicitConversionSequence::UserDefinedConversion) 461 ICS.ConversionKind = ImplicitConversionSequence::BadConversion; 462 } else { 463 ICS.ConversionKind = ImplicitConversionSequence::BadConversion; 464 if (UserDefResult == OR_Ambiguous) { 465 for (OverloadCandidateSet::iterator Cand = Conversions.begin(); 466 Cand != Conversions.end(); ++Cand) 467 ICS.ConversionFunctionSet.push_back(Cand->Function); 468 } 469 } 470 471 return ICS; 472} 473 474/// IsStandardConversion - Determines whether there is a standard 475/// conversion sequence (C++ [conv], C++ [over.ics.scs]) from the 476/// expression From to the type ToType. Standard conversion sequences 477/// only consider non-class types; for conversions that involve class 478/// types, use TryImplicitConversion. If a conversion exists, SCS will 479/// contain the standard conversion sequence required to perform this 480/// conversion and this routine will return true. Otherwise, this 481/// routine will return false and the value of SCS is unspecified. 482bool 483Sema::IsStandardConversion(Expr* From, QualType ToType, 484 bool InOverloadResolution, 485 StandardConversionSequence &SCS) { 486 QualType FromType = From->getType(); 487 488 // Standard conversions (C++ [conv]) 489 SCS.setAsIdentityConversion(); 490 SCS.Deprecated = false; 491 SCS.IncompatibleObjC = false; 492 SCS.FromTypePtr = FromType.getAsOpaquePtr(); 493 SCS.CopyConstructor = 0; 494 495 // There are no standard conversions for class types in C++, so 496 // abort early. When overloading in C, however, we do permit 497 if (FromType->isRecordType() || ToType->isRecordType()) { 498 if (getLangOptions().CPlusPlus) 499 return false; 500 501 // When we're overloading in C, we allow, as standard conversions, 502 } 503 504 // The first conversion can be an lvalue-to-rvalue conversion, 505 // array-to-pointer conversion, or function-to-pointer conversion 506 // (C++ 4p1). 507 508 // Lvalue-to-rvalue conversion (C++ 4.1): 509 // An lvalue (3.10) of a non-function, non-array type T can be 510 // converted to an rvalue. 511 Expr::isLvalueResult argIsLvalue = From->isLvalue(Context); 512 if (argIsLvalue == Expr::LV_Valid && 513 !FromType->isFunctionType() && !FromType->isArrayType() && 514 Context.getCanonicalType(FromType) != Context.OverloadTy) { 515 SCS.First = ICK_Lvalue_To_Rvalue; 516 517 // If T is a non-class type, the type of the rvalue is the 518 // cv-unqualified version of T. Otherwise, the type of the rvalue 519 // is T (C++ 4.1p1). C++ can't get here with class types; in C, we 520 // just strip the qualifiers because they don't matter. 521 522 // FIXME: Doesn't see through to qualifiers behind a typedef! 523 FromType = FromType.getUnqualifiedType(); 524 } else if (FromType->isArrayType()) { 525 // Array-to-pointer conversion (C++ 4.2) 526 SCS.First = ICK_Array_To_Pointer; 527 528 // An lvalue or rvalue of type "array of N T" or "array of unknown 529 // bound of T" can be converted to an rvalue of type "pointer to 530 // T" (C++ 4.2p1). 531 FromType = Context.getArrayDecayedType(FromType); 532 533 if (IsStringLiteralToNonConstPointerConversion(From, ToType)) { 534 // This conversion is deprecated. (C++ D.4). 535 SCS.Deprecated = true; 536 537 // For the purpose of ranking in overload resolution 538 // (13.3.3.1.1), this conversion is considered an 539 // array-to-pointer conversion followed by a qualification 540 // conversion (4.4). (C++ 4.2p2) 541 SCS.Second = ICK_Identity; 542 SCS.Third = ICK_Qualification; 543 SCS.ToTypePtr = ToType.getAsOpaquePtr(); 544 return true; 545 } 546 } else if (FromType->isFunctionType() && argIsLvalue == Expr::LV_Valid) { 547 // Function-to-pointer conversion (C++ 4.3). 548 SCS.First = ICK_Function_To_Pointer; 549 550 // An lvalue of function type T can be converted to an rvalue of 551 // type "pointer to T." The result is a pointer to the 552 // function. (C++ 4.3p1). 553 FromType = Context.getPointerType(FromType); 554 } else if (FunctionDecl *Fn 555 = ResolveAddressOfOverloadedFunction(From, ToType, false)) { 556 // Address of overloaded function (C++ [over.over]). 557 SCS.First = ICK_Function_To_Pointer; 558 559 // We were able to resolve the address of the overloaded function, 560 // so we can convert to the type of that function. 561 FromType = Fn->getType(); 562 if (ToType->isLValueReferenceType()) 563 FromType = Context.getLValueReferenceType(FromType); 564 else if (ToType->isRValueReferenceType()) 565 FromType = Context.getRValueReferenceType(FromType); 566 else if (ToType->isMemberPointerType()) { 567 // Resolve address only succeeds if both sides are member pointers, 568 // but it doesn't have to be the same class. See DR 247. 569 // Note that this means that the type of &Derived::fn can be 570 // Ret (Base::*)(Args) if the fn overload actually found is from the 571 // base class, even if it was brought into the derived class via a 572 // using declaration. The standard isn't clear on this issue at all. 573 CXXMethodDecl *M = cast<CXXMethodDecl>(Fn); 574 FromType = Context.getMemberPointerType(FromType, 575 Context.getTypeDeclType(M->getParent()).getTypePtr()); 576 } else 577 FromType = Context.getPointerType(FromType); 578 } else { 579 // We don't require any conversions for the first step. 580 SCS.First = ICK_Identity; 581 } 582 583 // The second conversion can be an integral promotion, floating 584 // point promotion, integral conversion, floating point conversion, 585 // floating-integral conversion, pointer conversion, 586 // pointer-to-member conversion, or boolean conversion (C++ 4p1). 587 // For overloading in C, this can also be a "compatible-type" 588 // conversion. 589 bool IncompatibleObjC = false; 590 if (Context.hasSameUnqualifiedType(FromType, ToType)) { 591 // The unqualified versions of the types are the same: there's no 592 // conversion to do. 593 SCS.Second = ICK_Identity; 594 } else if (IsIntegralPromotion(From, FromType, ToType)) { 595 // Integral promotion (C++ 4.5). 596 SCS.Second = ICK_Integral_Promotion; 597 FromType = ToType.getUnqualifiedType(); 598 } else if (IsFloatingPointPromotion(FromType, ToType)) { 599 // Floating point promotion (C++ 4.6). 600 SCS.Second = ICK_Floating_Promotion; 601 FromType = ToType.getUnqualifiedType(); 602 } else if (IsComplexPromotion(FromType, ToType)) { 603 // Complex promotion (Clang extension) 604 SCS.Second = ICK_Complex_Promotion; 605 FromType = ToType.getUnqualifiedType(); 606 } else if ((FromType->isIntegralType() || FromType->isEnumeralType()) && 607 (ToType->isIntegralType() && !ToType->isEnumeralType())) { 608 // Integral conversions (C++ 4.7). 609 // FIXME: isIntegralType shouldn't be true for enums in C++. 610 SCS.Second = ICK_Integral_Conversion; 611 FromType = ToType.getUnqualifiedType(); 612 } else if (FromType->isFloatingType() && ToType->isFloatingType()) { 613 // Floating point conversions (C++ 4.8). 614 SCS.Second = ICK_Floating_Conversion; 615 FromType = ToType.getUnqualifiedType(); 616 } else if (FromType->isComplexType() && ToType->isComplexType()) { 617 // Complex conversions (C99 6.3.1.6) 618 SCS.Second = ICK_Complex_Conversion; 619 FromType = ToType.getUnqualifiedType(); 620 } else if ((FromType->isFloatingType() && 621 ToType->isIntegralType() && (!ToType->isBooleanType() && 622 !ToType->isEnumeralType())) || 623 ((FromType->isIntegralType() || FromType->isEnumeralType()) && 624 ToType->isFloatingType())) { 625 // Floating-integral conversions (C++ 4.9). 626 // FIXME: isIntegralType shouldn't be true for enums in C++. 627 SCS.Second = ICK_Floating_Integral; 628 FromType = ToType.getUnqualifiedType(); 629 } else if ((FromType->isComplexType() && ToType->isArithmeticType()) || 630 (ToType->isComplexType() && FromType->isArithmeticType())) { 631 // Complex-real conversions (C99 6.3.1.7) 632 SCS.Second = ICK_Complex_Real; 633 FromType = ToType.getUnqualifiedType(); 634 } else if (IsPointerConversion(From, FromType, ToType, InOverloadResolution, 635 FromType, IncompatibleObjC)) { 636 // Pointer conversions (C++ 4.10). 637 SCS.Second = ICK_Pointer_Conversion; 638 SCS.IncompatibleObjC = IncompatibleObjC; 639 } else if (IsMemberPointerConversion(From, FromType, ToType, 640 InOverloadResolution, FromType)) { 641 // Pointer to member conversions (4.11). 642 SCS.Second = ICK_Pointer_Member; 643 } else if (ToType->isBooleanType() && 644 (FromType->isArithmeticType() || 645 FromType->isEnumeralType() || 646 FromType->isPointerType() || 647 FromType->isBlockPointerType() || 648 FromType->isMemberPointerType() || 649 FromType->isNullPtrType())) { 650 // Boolean conversions (C++ 4.12). 651 SCS.Second = ICK_Boolean_Conversion; 652 FromType = Context.BoolTy; 653 } else if (!getLangOptions().CPlusPlus && 654 Context.typesAreCompatible(ToType, FromType)) { 655 // Compatible conversions (Clang extension for C function overloading) 656 SCS.Second = ICK_Compatible_Conversion; 657 } else { 658 // No second conversion required. 659 SCS.Second = ICK_Identity; 660 } 661 662 QualType CanonFrom; 663 QualType CanonTo; 664 // The third conversion can be a qualification conversion (C++ 4p1). 665 if (IsQualificationConversion(FromType, ToType)) { 666 SCS.Third = ICK_Qualification; 667 FromType = ToType; 668 CanonFrom = Context.getCanonicalType(FromType); 669 CanonTo = Context.getCanonicalType(ToType); 670 } else { 671 // No conversion required 672 SCS.Third = ICK_Identity; 673 674 // C++ [over.best.ics]p6: 675 // [...] Any difference in top-level cv-qualification is 676 // subsumed by the initialization itself and does not constitute 677 // a conversion. [...] 678 CanonFrom = Context.getCanonicalType(FromType); 679 CanonTo = Context.getCanonicalType(ToType); 680 if (CanonFrom.getUnqualifiedType() == CanonTo.getUnqualifiedType() && 681 CanonFrom.getCVRQualifiers() != CanonTo.getCVRQualifiers()) { 682 FromType = ToType; 683 CanonFrom = CanonTo; 684 } 685 } 686 687 // If we have not converted the argument type to the parameter type, 688 // this is a bad conversion sequence. 689 if (CanonFrom != CanonTo) 690 return false; 691 692 SCS.ToTypePtr = FromType.getAsOpaquePtr(); 693 return true; 694} 695 696/// IsIntegralPromotion - Determines whether the conversion from the 697/// expression From (whose potentially-adjusted type is FromType) to 698/// ToType is an integral promotion (C++ 4.5). If so, returns true and 699/// sets PromotedType to the promoted type. 700bool Sema::IsIntegralPromotion(Expr *From, QualType FromType, QualType ToType) { 701 const BuiltinType *To = ToType->getAs<BuiltinType>(); 702 // All integers are built-in. 703 if (!To) { 704 return false; 705 } 706 707 // An rvalue of type char, signed char, unsigned char, short int, or 708 // unsigned short int can be converted to an rvalue of type int if 709 // int can represent all the values of the source type; otherwise, 710 // the source rvalue can be converted to an rvalue of type unsigned 711 // int (C++ 4.5p1). 712 if (FromType->isPromotableIntegerType() && !FromType->isBooleanType()) { 713 if (// We can promote any signed, promotable integer type to an int 714 (FromType->isSignedIntegerType() || 715 // We can promote any unsigned integer type whose size is 716 // less than int to an int. 717 (!FromType->isSignedIntegerType() && 718 Context.getTypeSize(FromType) < Context.getTypeSize(ToType)))) { 719 return To->getKind() == BuiltinType::Int; 720 } 721 722 return To->getKind() == BuiltinType::UInt; 723 } 724 725 // An rvalue of type wchar_t (3.9.1) or an enumeration type (7.2) 726 // can be converted to an rvalue of the first of the following types 727 // that can represent all the values of its underlying type: int, 728 // unsigned int, long, or unsigned long (C++ 4.5p2). 729 if ((FromType->isEnumeralType() || FromType->isWideCharType()) 730 && ToType->isIntegerType()) { 731 // Determine whether the type we're converting from is signed or 732 // unsigned. 733 bool FromIsSigned; 734 uint64_t FromSize = Context.getTypeSize(FromType); 735 if (const EnumType *FromEnumType = FromType->getAs<EnumType>()) { 736 QualType UnderlyingType = FromEnumType->getDecl()->getIntegerType(); 737 FromIsSigned = UnderlyingType->isSignedIntegerType(); 738 } else { 739 // FIXME: Is wchar_t signed or unsigned? We assume it's signed for now. 740 FromIsSigned = true; 741 } 742 743 // The types we'll try to promote to, in the appropriate 744 // order. Try each of these types. 745 QualType PromoteTypes[6] = { 746 Context.IntTy, Context.UnsignedIntTy, 747 Context.LongTy, Context.UnsignedLongTy , 748 Context.LongLongTy, Context.UnsignedLongLongTy 749 }; 750 for (int Idx = 0; Idx < 6; ++Idx) { 751 uint64_t ToSize = Context.getTypeSize(PromoteTypes[Idx]); 752 if (FromSize < ToSize || 753 (FromSize == ToSize && 754 FromIsSigned == PromoteTypes[Idx]->isSignedIntegerType())) { 755 // We found the type that we can promote to. If this is the 756 // type we wanted, we have a promotion. Otherwise, no 757 // promotion. 758 return Context.getCanonicalType(ToType).getUnqualifiedType() 759 == Context.getCanonicalType(PromoteTypes[Idx]).getUnqualifiedType(); 760 } 761 } 762 } 763 764 // An rvalue for an integral bit-field (9.6) can be converted to an 765 // rvalue of type int if int can represent all the values of the 766 // bit-field; otherwise, it can be converted to unsigned int if 767 // unsigned int can represent all the values of the bit-field. If 768 // the bit-field is larger yet, no integral promotion applies to 769 // it. If the bit-field has an enumerated type, it is treated as any 770 // other value of that type for promotion purposes (C++ 4.5p3). 771 // FIXME: We should delay checking of bit-fields until we actually perform the 772 // conversion. 773 using llvm::APSInt; 774 if (From) 775 if (FieldDecl *MemberDecl = From->getBitField()) { 776 APSInt BitWidth; 777 if (FromType->isIntegralType() && !FromType->isEnumeralType() && 778 MemberDecl->getBitWidth()->isIntegerConstantExpr(BitWidth, Context)) { 779 APSInt ToSize(BitWidth.getBitWidth(), BitWidth.isUnsigned()); 780 ToSize = Context.getTypeSize(ToType); 781 782 // Are we promoting to an int from a bitfield that fits in an int? 783 if (BitWidth < ToSize || 784 (FromType->isSignedIntegerType() && BitWidth <= ToSize)) { 785 return To->getKind() == BuiltinType::Int; 786 } 787 788 // Are we promoting to an unsigned int from an unsigned bitfield 789 // that fits into an unsigned int? 790 if (FromType->isUnsignedIntegerType() && BitWidth <= ToSize) { 791 return To->getKind() == BuiltinType::UInt; 792 } 793 794 return false; 795 } 796 } 797 798 // An rvalue of type bool can be converted to an rvalue of type int, 799 // with false becoming zero and true becoming one (C++ 4.5p4). 800 if (FromType->isBooleanType() && To->getKind() == BuiltinType::Int) { 801 return true; 802 } 803 804 return false; 805} 806 807/// IsFloatingPointPromotion - Determines whether the conversion from 808/// FromType to ToType is a floating point promotion (C++ 4.6). If so, 809/// returns true and sets PromotedType to the promoted type. 810bool Sema::IsFloatingPointPromotion(QualType FromType, QualType ToType) { 811 /// An rvalue of type float can be converted to an rvalue of type 812 /// double. (C++ 4.6p1). 813 if (const BuiltinType *FromBuiltin = FromType->getAs<BuiltinType>()) 814 if (const BuiltinType *ToBuiltin = ToType->getAs<BuiltinType>()) { 815 if (FromBuiltin->getKind() == BuiltinType::Float && 816 ToBuiltin->getKind() == BuiltinType::Double) 817 return true; 818 819 // C99 6.3.1.5p1: 820 // When a float is promoted to double or long double, or a 821 // double is promoted to long double [...]. 822 if (!getLangOptions().CPlusPlus && 823 (FromBuiltin->getKind() == BuiltinType::Float || 824 FromBuiltin->getKind() == BuiltinType::Double) && 825 (ToBuiltin->getKind() == BuiltinType::LongDouble)) 826 return true; 827 } 828 829 return false; 830} 831 832/// \brief Determine if a conversion is a complex promotion. 833/// 834/// A complex promotion is defined as a complex -> complex conversion 835/// where the conversion between the underlying real types is a 836/// floating-point or integral promotion. 837bool Sema::IsComplexPromotion(QualType FromType, QualType ToType) { 838 const ComplexType *FromComplex = FromType->getAs<ComplexType>(); 839 if (!FromComplex) 840 return false; 841 842 const ComplexType *ToComplex = ToType->getAs<ComplexType>(); 843 if (!ToComplex) 844 return false; 845 846 return IsFloatingPointPromotion(FromComplex->getElementType(), 847 ToComplex->getElementType()) || 848 IsIntegralPromotion(0, FromComplex->getElementType(), 849 ToComplex->getElementType()); 850} 851 852/// BuildSimilarlyQualifiedPointerType - In a pointer conversion from 853/// the pointer type FromPtr to a pointer to type ToPointee, with the 854/// same type qualifiers as FromPtr has on its pointee type. ToType, 855/// if non-empty, will be a pointer to ToType that may or may not have 856/// the right set of qualifiers on its pointee. 857static QualType 858BuildSimilarlyQualifiedPointerType(const PointerType *FromPtr, 859 QualType ToPointee, QualType ToType, 860 ASTContext &Context) { 861 QualType CanonFromPointee = Context.getCanonicalType(FromPtr->getPointeeType()); 862 QualType CanonToPointee = Context.getCanonicalType(ToPointee); 863 Qualifiers Quals = CanonFromPointee.getQualifiers(); 864 865 // Exact qualifier match -> return the pointer type we're converting to. 866 if (CanonToPointee.getQualifiers() == Quals) { 867 // ToType is exactly what we need. Return it. 868 if (!ToType.isNull()) 869 return ToType; 870 871 // Build a pointer to ToPointee. It has the right qualifiers 872 // already. 873 return Context.getPointerType(ToPointee); 874 } 875 876 // Just build a canonical type that has the right qualifiers. 877 return Context.getPointerType( 878 Context.getQualifiedType(CanonToPointee.getUnqualifiedType(), Quals)); 879} 880 881static bool isNullPointerConstantForConversion(Expr *Expr, 882 bool InOverloadResolution, 883 ASTContext &Context) { 884 // Handle value-dependent integral null pointer constants correctly. 885 // http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#903 886 if (Expr->isValueDependent() && !Expr->isTypeDependent() && 887 Expr->getType()->isIntegralType()) 888 return !InOverloadResolution; 889 890 if (Expr->getType()->isEnumeralType()) 891 return !InOverloadResolution; 892 893 return Expr->isNullPointerConstant(Context, 894 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull 895 : Expr::NPC_ValueDependentIsNull); 896} 897 898/// IsPointerConversion - Determines whether the conversion of the 899/// expression From, which has the (possibly adjusted) type FromType, 900/// can be converted to the type ToType via a pointer conversion (C++ 901/// 4.10). If so, returns true and places the converted type (that 902/// might differ from ToType in its cv-qualifiers at some level) into 903/// ConvertedType. 904/// 905/// This routine also supports conversions to and from block pointers 906/// and conversions with Objective-C's 'id', 'id<protocols...>', and 907/// pointers to interfaces. FIXME: Once we've determined the 908/// appropriate overloading rules for Objective-C, we may want to 909/// split the Objective-C checks into a different routine; however, 910/// GCC seems to consider all of these conversions to be pointer 911/// conversions, so for now they live here. IncompatibleObjC will be 912/// set if the conversion is an allowed Objective-C conversion that 913/// should result in a warning. 914bool Sema::IsPointerConversion(Expr *From, QualType FromType, QualType ToType, 915 bool InOverloadResolution, 916 QualType& ConvertedType, 917 bool &IncompatibleObjC) { 918 IncompatibleObjC = false; 919 if (isObjCPointerConversion(FromType, ToType, ConvertedType, IncompatibleObjC)) 920 return true; 921 922 // Conversion from a null pointer constant to any Objective-C pointer type. 923 if (ToType->isObjCObjectPointerType() && 924 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 925 ConvertedType = ToType; 926 return true; 927 } 928 929 // Blocks: Block pointers can be converted to void*. 930 if (FromType->isBlockPointerType() && ToType->isPointerType() && 931 ToType->getAs<PointerType>()->getPointeeType()->isVoidType()) { 932 ConvertedType = ToType; 933 return true; 934 } 935 // Blocks: A null pointer constant can be converted to a block 936 // pointer type. 937 if (ToType->isBlockPointerType() && 938 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 939 ConvertedType = ToType; 940 return true; 941 } 942 943 // If the left-hand-side is nullptr_t, the right side can be a null 944 // pointer constant. 945 if (ToType->isNullPtrType() && 946 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 947 ConvertedType = ToType; 948 return true; 949 } 950 951 const PointerType* ToTypePtr = ToType->getAs<PointerType>(); 952 if (!ToTypePtr) 953 return false; 954 955 // A null pointer constant can be converted to a pointer type (C++ 4.10p1). 956 if (isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 957 ConvertedType = ToType; 958 return true; 959 } 960 961 // Beyond this point, both types need to be pointers. 962 const PointerType *FromTypePtr = FromType->getAs<PointerType>(); 963 if (!FromTypePtr) 964 return false; 965 966 QualType FromPointeeType = FromTypePtr->getPointeeType(); 967 QualType ToPointeeType = ToTypePtr->getPointeeType(); 968 969 // An rvalue of type "pointer to cv T," where T is an object type, 970 // can be converted to an rvalue of type "pointer to cv void" (C++ 971 // 4.10p2). 972 if (FromPointeeType->isObjectType() && ToPointeeType->isVoidType()) { 973 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 974 ToPointeeType, 975 ToType, Context); 976 return true; 977 } 978 979 // When we're overloading in C, we allow a special kind of pointer 980 // conversion for compatible-but-not-identical pointee types. 981 if (!getLangOptions().CPlusPlus && 982 Context.typesAreCompatible(FromPointeeType, ToPointeeType)) { 983 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 984 ToPointeeType, 985 ToType, Context); 986 return true; 987 } 988 989 // C++ [conv.ptr]p3: 990 // 991 // An rvalue of type "pointer to cv D," where D is a class type, 992 // can be converted to an rvalue of type "pointer to cv B," where 993 // B is a base class (clause 10) of D. If B is an inaccessible 994 // (clause 11) or ambiguous (10.2) base class of D, a program that 995 // necessitates this conversion is ill-formed. The result of the 996 // conversion is a pointer to the base class sub-object of the 997 // derived class object. The null pointer value is converted to 998 // the null pointer value of the destination type. 999 // 1000 // Note that we do not check for ambiguity or inaccessibility 1001 // here. That is handled by CheckPointerConversion. 1002 if (getLangOptions().CPlusPlus && 1003 FromPointeeType->isRecordType() && ToPointeeType->isRecordType() && 1004 IsDerivedFrom(FromPointeeType, ToPointeeType)) { 1005 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1006 ToPointeeType, 1007 ToType, Context); 1008 return true; 1009 } 1010 1011 return false; 1012} 1013 1014/// isObjCPointerConversion - Determines whether this is an 1015/// Objective-C pointer conversion. Subroutine of IsPointerConversion, 1016/// with the same arguments and return values. 1017bool Sema::isObjCPointerConversion(QualType FromType, QualType ToType, 1018 QualType& ConvertedType, 1019 bool &IncompatibleObjC) { 1020 if (!getLangOptions().ObjC1) 1021 return false; 1022 1023 // First, we handle all conversions on ObjC object pointer types. 1024 const ObjCObjectPointerType* ToObjCPtr = ToType->getAs<ObjCObjectPointerType>(); 1025 const ObjCObjectPointerType *FromObjCPtr = 1026 FromType->getAs<ObjCObjectPointerType>(); 1027 1028 if (ToObjCPtr && FromObjCPtr) { 1029 // Objective C++: We're able to convert between "id" or "Class" and a 1030 // pointer to any interface (in both directions). 1031 if (ToObjCPtr->isObjCBuiltinType() && FromObjCPtr->isObjCBuiltinType()) { 1032 ConvertedType = ToType; 1033 return true; 1034 } 1035 // Conversions with Objective-C's id<...>. 1036 if ((FromObjCPtr->isObjCQualifiedIdType() || 1037 ToObjCPtr->isObjCQualifiedIdType()) && 1038 Context.ObjCQualifiedIdTypesAreCompatible(ToType, FromType, 1039 /*compare=*/false)) { 1040 ConvertedType = ToType; 1041 return true; 1042 } 1043 // Objective C++: We're able to convert from a pointer to an 1044 // interface to a pointer to a different interface. 1045 if (Context.canAssignObjCInterfaces(ToObjCPtr, FromObjCPtr)) { 1046 ConvertedType = ToType; 1047 return true; 1048 } 1049 1050 if (Context.canAssignObjCInterfaces(FromObjCPtr, ToObjCPtr)) { 1051 // Okay: this is some kind of implicit downcast of Objective-C 1052 // interfaces, which is permitted. However, we're going to 1053 // complain about it. 1054 IncompatibleObjC = true; 1055 ConvertedType = FromType; 1056 return true; 1057 } 1058 } 1059 // Beyond this point, both types need to be C pointers or block pointers. 1060 QualType ToPointeeType; 1061 if (const PointerType *ToCPtr = ToType->getAs<PointerType>()) 1062 ToPointeeType = ToCPtr->getPointeeType(); 1063 else if (const BlockPointerType *ToBlockPtr = ToType->getAs<BlockPointerType>()) 1064 ToPointeeType = ToBlockPtr->getPointeeType(); 1065 else 1066 return false; 1067 1068 QualType FromPointeeType; 1069 if (const PointerType *FromCPtr = FromType->getAs<PointerType>()) 1070 FromPointeeType = FromCPtr->getPointeeType(); 1071 else if (const BlockPointerType *FromBlockPtr = FromType->getAs<BlockPointerType>()) 1072 FromPointeeType = FromBlockPtr->getPointeeType(); 1073 else 1074 return false; 1075 1076 // If we have pointers to pointers, recursively check whether this 1077 // is an Objective-C conversion. 1078 if (FromPointeeType->isPointerType() && ToPointeeType->isPointerType() && 1079 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, 1080 IncompatibleObjC)) { 1081 // We always complain about this conversion. 1082 IncompatibleObjC = true; 1083 ConvertedType = ToType; 1084 return true; 1085 } 1086 // If we have pointers to functions or blocks, check whether the only 1087 // differences in the argument and result types are in Objective-C 1088 // pointer conversions. If so, we permit the conversion (but 1089 // complain about it). 1090 const FunctionProtoType *FromFunctionType 1091 = FromPointeeType->getAs<FunctionProtoType>(); 1092 const FunctionProtoType *ToFunctionType 1093 = ToPointeeType->getAs<FunctionProtoType>(); 1094 if (FromFunctionType && ToFunctionType) { 1095 // If the function types are exactly the same, this isn't an 1096 // Objective-C pointer conversion. 1097 if (Context.getCanonicalType(FromPointeeType) 1098 == Context.getCanonicalType(ToPointeeType)) 1099 return false; 1100 1101 // Perform the quick checks that will tell us whether these 1102 // function types are obviously different. 1103 if (FromFunctionType->getNumArgs() != ToFunctionType->getNumArgs() || 1104 FromFunctionType->isVariadic() != ToFunctionType->isVariadic() || 1105 FromFunctionType->getTypeQuals() != ToFunctionType->getTypeQuals()) 1106 return false; 1107 1108 bool HasObjCConversion = false; 1109 if (Context.getCanonicalType(FromFunctionType->getResultType()) 1110 == Context.getCanonicalType(ToFunctionType->getResultType())) { 1111 // Okay, the types match exactly. Nothing to do. 1112 } else if (isObjCPointerConversion(FromFunctionType->getResultType(), 1113 ToFunctionType->getResultType(), 1114 ConvertedType, IncompatibleObjC)) { 1115 // Okay, we have an Objective-C pointer conversion. 1116 HasObjCConversion = true; 1117 } else { 1118 // Function types are too different. Abort. 1119 return false; 1120 } 1121 1122 // Check argument types. 1123 for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumArgs(); 1124 ArgIdx != NumArgs; ++ArgIdx) { 1125 QualType FromArgType = FromFunctionType->getArgType(ArgIdx); 1126 QualType ToArgType = ToFunctionType->getArgType(ArgIdx); 1127 if (Context.getCanonicalType(FromArgType) 1128 == Context.getCanonicalType(ToArgType)) { 1129 // Okay, the types match exactly. Nothing to do. 1130 } else if (isObjCPointerConversion(FromArgType, ToArgType, 1131 ConvertedType, IncompatibleObjC)) { 1132 // Okay, we have an Objective-C pointer conversion. 1133 HasObjCConversion = true; 1134 } else { 1135 // Argument types are too different. Abort. 1136 return false; 1137 } 1138 } 1139 1140 if (HasObjCConversion) { 1141 // We had an Objective-C conversion. Allow this pointer 1142 // conversion, but complain about it. 1143 ConvertedType = ToType; 1144 IncompatibleObjC = true; 1145 return true; 1146 } 1147 } 1148 1149 return false; 1150} 1151 1152/// CheckPointerConversion - Check the pointer conversion from the 1153/// expression From to the type ToType. This routine checks for 1154/// ambiguous or inaccessible derived-to-base pointer 1155/// conversions for which IsPointerConversion has already returned 1156/// true. It returns true and produces a diagnostic if there was an 1157/// error, or returns false otherwise. 1158bool Sema::CheckPointerConversion(Expr *From, QualType ToType, 1159 CastExpr::CastKind &Kind) { 1160 QualType FromType = From->getType(); 1161 1162 if (const PointerType *FromPtrType = FromType->getAs<PointerType>()) 1163 if (const PointerType *ToPtrType = ToType->getAs<PointerType>()) { 1164 QualType FromPointeeType = FromPtrType->getPointeeType(), 1165 ToPointeeType = ToPtrType->getPointeeType(); 1166 1167 if (FromPointeeType->isRecordType() && 1168 ToPointeeType->isRecordType()) { 1169 // We must have a derived-to-base conversion. Check an 1170 // ambiguous or inaccessible conversion. 1171 if (CheckDerivedToBaseConversion(FromPointeeType, ToPointeeType, 1172 From->getExprLoc(), 1173 From->getSourceRange())) 1174 return true; 1175 1176 // The conversion was successful. 1177 Kind = CastExpr::CK_DerivedToBase; 1178 } 1179 } 1180 if (const ObjCObjectPointerType *FromPtrType = 1181 FromType->getAs<ObjCObjectPointerType>()) 1182 if (const ObjCObjectPointerType *ToPtrType = 1183 ToType->getAs<ObjCObjectPointerType>()) { 1184 // Objective-C++ conversions are always okay. 1185 // FIXME: We should have a different class of conversions for the 1186 // Objective-C++ implicit conversions. 1187 if (FromPtrType->isObjCBuiltinType() || ToPtrType->isObjCBuiltinType()) 1188 return false; 1189 1190 } 1191 return false; 1192} 1193 1194/// IsMemberPointerConversion - Determines whether the conversion of the 1195/// expression From, which has the (possibly adjusted) type FromType, can be 1196/// converted to the type ToType via a member pointer conversion (C++ 4.11). 1197/// If so, returns true and places the converted type (that might differ from 1198/// ToType in its cv-qualifiers at some level) into ConvertedType. 1199bool Sema::IsMemberPointerConversion(Expr *From, QualType FromType, 1200 QualType ToType, 1201 bool InOverloadResolution, 1202 QualType &ConvertedType) { 1203 const MemberPointerType *ToTypePtr = ToType->getAs<MemberPointerType>(); 1204 if (!ToTypePtr) 1205 return false; 1206 1207 // A null pointer constant can be converted to a member pointer (C++ 4.11p1) 1208 if (From->isNullPointerConstant(Context, 1209 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull 1210 : Expr::NPC_ValueDependentIsNull)) { 1211 ConvertedType = ToType; 1212 return true; 1213 } 1214 1215 // Otherwise, both types have to be member pointers. 1216 const MemberPointerType *FromTypePtr = FromType->getAs<MemberPointerType>(); 1217 if (!FromTypePtr) 1218 return false; 1219 1220 // A pointer to member of B can be converted to a pointer to member of D, 1221 // where D is derived from B (C++ 4.11p2). 1222 QualType FromClass(FromTypePtr->getClass(), 0); 1223 QualType ToClass(ToTypePtr->getClass(), 0); 1224 // FIXME: What happens when these are dependent? Is this function even called? 1225 1226 if (IsDerivedFrom(ToClass, FromClass)) { 1227 ConvertedType = Context.getMemberPointerType(FromTypePtr->getPointeeType(), 1228 ToClass.getTypePtr()); 1229 return true; 1230 } 1231 1232 return false; 1233} 1234 1235/// CheckMemberPointerConversion - Check the member pointer conversion from the 1236/// expression From to the type ToType. This routine checks for ambiguous or 1237/// virtual (FIXME: or inaccessible) base-to-derived member pointer conversions 1238/// for which IsMemberPointerConversion has already returned true. It returns 1239/// true and produces a diagnostic if there was an error, or returns false 1240/// otherwise. 1241bool Sema::CheckMemberPointerConversion(Expr *From, QualType ToType, 1242 CastExpr::CastKind &Kind) { 1243 QualType FromType = From->getType(); 1244 const MemberPointerType *FromPtrType = FromType->getAs<MemberPointerType>(); 1245 if (!FromPtrType) { 1246 // This must be a null pointer to member pointer conversion 1247 assert(From->isNullPointerConstant(Context, 1248 Expr::NPC_ValueDependentIsNull) && 1249 "Expr must be null pointer constant!"); 1250 Kind = CastExpr::CK_NullToMemberPointer; 1251 return false; 1252 } 1253 1254 const MemberPointerType *ToPtrType = ToType->getAs<MemberPointerType>(); 1255 assert(ToPtrType && "No member pointer cast has a target type " 1256 "that is not a member pointer."); 1257 1258 QualType FromClass = QualType(FromPtrType->getClass(), 0); 1259 QualType ToClass = QualType(ToPtrType->getClass(), 0); 1260 1261 // FIXME: What about dependent types? 1262 assert(FromClass->isRecordType() && "Pointer into non-class."); 1263 assert(ToClass->isRecordType() && "Pointer into non-class."); 1264 1265 BasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/false, 1266 /*DetectVirtual=*/true); 1267 bool DerivationOkay = IsDerivedFrom(ToClass, FromClass, Paths); 1268 assert(DerivationOkay && 1269 "Should not have been called if derivation isn't OK."); 1270 (void)DerivationOkay; 1271 1272 if (Paths.isAmbiguous(Context.getCanonicalType(FromClass). 1273 getUnqualifiedType())) { 1274 // Derivation is ambiguous. Redo the check to find the exact paths. 1275 Paths.clear(); 1276 Paths.setRecordingPaths(true); 1277 bool StillOkay = IsDerivedFrom(ToClass, FromClass, Paths); 1278 assert(StillOkay && "Derivation changed due to quantum fluctuation."); 1279 (void)StillOkay; 1280 1281 std::string PathDisplayStr = getAmbiguousPathsDisplayString(Paths); 1282 Diag(From->getExprLoc(), diag::err_ambiguous_memptr_conv) 1283 << 0 << FromClass << ToClass << PathDisplayStr << From->getSourceRange(); 1284 return true; 1285 } 1286 1287 if (const RecordType *VBase = Paths.getDetectedVirtual()) { 1288 Diag(From->getExprLoc(), diag::err_memptr_conv_via_virtual) 1289 << FromClass << ToClass << QualType(VBase, 0) 1290 << From->getSourceRange(); 1291 return true; 1292 } 1293 1294 // Must be a base to derived member conversion. 1295 Kind = CastExpr::CK_BaseToDerivedMemberPointer; 1296 return false; 1297} 1298 1299/// IsQualificationConversion - Determines whether the conversion from 1300/// an rvalue of type FromType to ToType is a qualification conversion 1301/// (C++ 4.4). 1302bool 1303Sema::IsQualificationConversion(QualType FromType, QualType ToType) { 1304 FromType = Context.getCanonicalType(FromType); 1305 ToType = Context.getCanonicalType(ToType); 1306 1307 // If FromType and ToType are the same type, this is not a 1308 // qualification conversion. 1309 if (FromType == ToType) 1310 return false; 1311 1312 // (C++ 4.4p4): 1313 // A conversion can add cv-qualifiers at levels other than the first 1314 // in multi-level pointers, subject to the following rules: [...] 1315 bool PreviousToQualsIncludeConst = true; 1316 bool UnwrappedAnyPointer = false; 1317 while (UnwrapSimilarPointerTypes(FromType, ToType)) { 1318 // Within each iteration of the loop, we check the qualifiers to 1319 // determine if this still looks like a qualification 1320 // conversion. Then, if all is well, we unwrap one more level of 1321 // pointers or pointers-to-members and do it all again 1322 // until there are no more pointers or pointers-to-members left to 1323 // unwrap. 1324 UnwrappedAnyPointer = true; 1325 1326 // -- for every j > 0, if const is in cv 1,j then const is in cv 1327 // 2,j, and similarly for volatile. 1328 if (!ToType.isAtLeastAsQualifiedAs(FromType)) 1329 return false; 1330 1331 // -- if the cv 1,j and cv 2,j are different, then const is in 1332 // every cv for 0 < k < j. 1333 if (FromType.getCVRQualifiers() != ToType.getCVRQualifiers() 1334 && !PreviousToQualsIncludeConst) 1335 return false; 1336 1337 // Keep track of whether all prior cv-qualifiers in the "to" type 1338 // include const. 1339 PreviousToQualsIncludeConst 1340 = PreviousToQualsIncludeConst && ToType.isConstQualified(); 1341 } 1342 1343 // We are left with FromType and ToType being the pointee types 1344 // after unwrapping the original FromType and ToType the same number 1345 // of types. If we unwrapped any pointers, and if FromType and 1346 // ToType have the same unqualified type (since we checked 1347 // qualifiers above), then this is a qualification conversion. 1348 return UnwrappedAnyPointer && 1349 FromType.getUnqualifiedType() == ToType.getUnqualifiedType(); 1350} 1351 1352/// \brief Given a function template or function, extract the function template 1353/// declaration (if any) and the underlying function declaration. 1354template<typename T> 1355static void GetFunctionAndTemplate(AnyFunctionDecl Orig, T *&Function, 1356 FunctionTemplateDecl *&FunctionTemplate) { 1357 FunctionTemplate = dyn_cast<FunctionTemplateDecl>(Orig); 1358 if (FunctionTemplate) 1359 Function = cast<T>(FunctionTemplate->getTemplatedDecl()); 1360 else 1361 Function = cast<T>(Orig); 1362} 1363 1364/// Determines whether there is a user-defined conversion sequence 1365/// (C++ [over.ics.user]) that converts expression From to the type 1366/// ToType. If such a conversion exists, User will contain the 1367/// user-defined conversion sequence that performs such a conversion 1368/// and this routine will return true. Otherwise, this routine returns 1369/// false and User is unspecified. 1370/// 1371/// \param AllowConversionFunctions true if the conversion should 1372/// consider conversion functions at all. If false, only constructors 1373/// will be considered. 1374/// 1375/// \param AllowExplicit true if the conversion should consider C++0x 1376/// "explicit" conversion functions as well as non-explicit conversion 1377/// functions (C++0x [class.conv.fct]p2). 1378/// 1379/// \param ForceRValue true if the expression should be treated as an rvalue 1380/// for overload resolution. 1381/// \param UserCast true if looking for user defined conversion for a static 1382/// cast. 1383Sema::OverloadingResult Sema::IsUserDefinedConversion( 1384 Expr *From, QualType ToType, 1385 UserDefinedConversionSequence& User, 1386 OverloadCandidateSet& CandidateSet, 1387 bool AllowConversionFunctions, 1388 bool AllowExplicit, bool ForceRValue, 1389 bool UserCast) { 1390 if (const RecordType *ToRecordType = ToType->getAs<RecordType>()) { 1391 if (CXXRecordDecl *ToRecordDecl 1392 = dyn_cast<CXXRecordDecl>(ToRecordType->getDecl())) { 1393 // C++ [over.match.ctor]p1: 1394 // When objects of class type are direct-initialized (8.5), or 1395 // copy-initialized from an expression of the same or a 1396 // derived class type (8.5), overload resolution selects the 1397 // constructor. [...] For copy-initialization, the candidate 1398 // functions are all the converting constructors (12.3.1) of 1399 // that class. The argument list is the expression-list within 1400 // the parentheses of the initializer. 1401 DeclarationName ConstructorName 1402 = Context.DeclarationNames.getCXXConstructorName( 1403 Context.getCanonicalType(ToType).getUnqualifiedType()); 1404 DeclContext::lookup_iterator Con, ConEnd; 1405 for (llvm::tie(Con, ConEnd) 1406 = ToRecordDecl->lookup(ConstructorName); 1407 Con != ConEnd; ++Con) { 1408 // Find the constructor (which may be a template). 1409 CXXConstructorDecl *Constructor = 0; 1410 FunctionTemplateDecl *ConstructorTmpl 1411 = dyn_cast<FunctionTemplateDecl>(*Con); 1412 if (ConstructorTmpl) 1413 Constructor 1414 = cast<CXXConstructorDecl>(ConstructorTmpl->getTemplatedDecl()); 1415 else 1416 Constructor = cast<CXXConstructorDecl>(*Con); 1417 1418 if (!Constructor->isInvalidDecl() && 1419 Constructor->isConvertingConstructor(AllowExplicit)) { 1420 if (ConstructorTmpl) 1421 AddTemplateOverloadCandidate(ConstructorTmpl, false, 0, 0, &From, 1422 1, CandidateSet, 1423 /*SuppressUserConversions=*/!UserCast, 1424 ForceRValue); 1425 else 1426 // Allow one user-defined conversion when user specifies a 1427 // From->ToType conversion via an static cast (c-style, etc). 1428 AddOverloadCandidate(Constructor, &From, 1, CandidateSet, 1429 /*SuppressUserConversions=*/!UserCast, 1430 ForceRValue); 1431 } 1432 } 1433 } 1434 } 1435 1436 if (!AllowConversionFunctions) { 1437 // Don't allow any conversion functions to enter the overload set. 1438 } else if (RequireCompleteType(From->getLocStart(), From->getType(), 1439 PDiag(0) 1440 << From->getSourceRange())) { 1441 // No conversion functions from incomplete types. 1442 } else if (const RecordType *FromRecordType 1443 = From->getType()->getAs<RecordType>()) { 1444 if (CXXRecordDecl *FromRecordDecl 1445 = dyn_cast<CXXRecordDecl>(FromRecordType->getDecl())) { 1446 // Add all of the conversion functions as candidates. 1447 OverloadedFunctionDecl *Conversions 1448 = FromRecordDecl->getVisibleConversionFunctions(); 1449 for (OverloadedFunctionDecl::function_iterator Func 1450 = Conversions->function_begin(); 1451 Func != Conversions->function_end(); ++Func) { 1452 CXXConversionDecl *Conv; 1453 FunctionTemplateDecl *ConvTemplate; 1454 GetFunctionAndTemplate(*Func, Conv, ConvTemplate); 1455 if (ConvTemplate) 1456 Conv = dyn_cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 1457 else 1458 Conv = dyn_cast<CXXConversionDecl>(*Func); 1459 1460 if (AllowExplicit || !Conv->isExplicit()) { 1461 if (ConvTemplate) 1462 AddTemplateConversionCandidate(ConvTemplate, From, ToType, 1463 CandidateSet); 1464 else 1465 AddConversionCandidate(Conv, From, ToType, CandidateSet); 1466 } 1467 } 1468 } 1469 } 1470 1471 OverloadCandidateSet::iterator Best; 1472 switch (BestViableFunction(CandidateSet, From->getLocStart(), Best)) { 1473 case OR_Success: 1474 // Record the standard conversion we used and the conversion function. 1475 if (CXXConstructorDecl *Constructor 1476 = dyn_cast<CXXConstructorDecl>(Best->Function)) { 1477 // C++ [over.ics.user]p1: 1478 // If the user-defined conversion is specified by a 1479 // constructor (12.3.1), the initial standard conversion 1480 // sequence converts the source type to the type required by 1481 // the argument of the constructor. 1482 // 1483 // FIXME: What about ellipsis conversions? 1484 QualType ThisType = Constructor->getThisType(Context); 1485 User.Before = Best->Conversions[0].Standard; 1486 User.ConversionFunction = Constructor; 1487 User.After.setAsIdentityConversion(); 1488 User.After.FromTypePtr 1489 = ThisType->getAs<PointerType>()->getPointeeType().getAsOpaquePtr(); 1490 User.After.ToTypePtr = ToType.getAsOpaquePtr(); 1491 return OR_Success; 1492 } else if (CXXConversionDecl *Conversion 1493 = dyn_cast<CXXConversionDecl>(Best->Function)) { 1494 // C++ [over.ics.user]p1: 1495 // 1496 // [...] If the user-defined conversion is specified by a 1497 // conversion function (12.3.2), the initial standard 1498 // conversion sequence converts the source type to the 1499 // implicit object parameter of the conversion function. 1500 User.Before = Best->Conversions[0].Standard; 1501 User.ConversionFunction = Conversion; 1502 1503 // C++ [over.ics.user]p2: 1504 // The second standard conversion sequence converts the 1505 // result of the user-defined conversion to the target type 1506 // for the sequence. Since an implicit conversion sequence 1507 // is an initialization, the special rules for 1508 // initialization by user-defined conversion apply when 1509 // selecting the best user-defined conversion for a 1510 // user-defined conversion sequence (see 13.3.3 and 1511 // 13.3.3.1). 1512 User.After = Best->FinalConversion; 1513 return OR_Success; 1514 } else { 1515 assert(false && "Not a constructor or conversion function?"); 1516 return OR_No_Viable_Function; 1517 } 1518 1519 case OR_No_Viable_Function: 1520 return OR_No_Viable_Function; 1521 case OR_Deleted: 1522 // No conversion here! We're done. 1523 return OR_Deleted; 1524 1525 case OR_Ambiguous: 1526 return OR_Ambiguous; 1527 } 1528 1529 return OR_No_Viable_Function; 1530} 1531 1532bool 1533Sema::DiagnoseAmbiguousUserDefinedConversion(Expr *From, QualType ToType) { 1534 ImplicitConversionSequence ICS; 1535 OverloadCandidateSet CandidateSet; 1536 OverloadingResult OvResult = 1537 IsUserDefinedConversion(From, ToType, ICS.UserDefined, 1538 CandidateSet, true, false, false); 1539 if (OvResult != OR_Ambiguous) 1540 return false; 1541 Diag(From->getSourceRange().getBegin(), 1542 diag::err_typecheck_ambiguous_condition) 1543 << From->getType() << ToType << From->getSourceRange(); 1544 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 1545 return true; 1546} 1547 1548/// CompareImplicitConversionSequences - Compare two implicit 1549/// conversion sequences to determine whether one is better than the 1550/// other or if they are indistinguishable (C++ 13.3.3.2). 1551ImplicitConversionSequence::CompareKind 1552Sema::CompareImplicitConversionSequences(const ImplicitConversionSequence& ICS1, 1553 const ImplicitConversionSequence& ICS2) 1554{ 1555 // (C++ 13.3.3.2p2): When comparing the basic forms of implicit 1556 // conversion sequences (as defined in 13.3.3.1) 1557 // -- a standard conversion sequence (13.3.3.1.1) is a better 1558 // conversion sequence than a user-defined conversion sequence or 1559 // an ellipsis conversion sequence, and 1560 // -- a user-defined conversion sequence (13.3.3.1.2) is a better 1561 // conversion sequence than an ellipsis conversion sequence 1562 // (13.3.3.1.3). 1563 // 1564 if (ICS1.ConversionKind < ICS2.ConversionKind) 1565 return ImplicitConversionSequence::Better; 1566 else if (ICS2.ConversionKind < ICS1.ConversionKind) 1567 return ImplicitConversionSequence::Worse; 1568 1569 // Two implicit conversion sequences of the same form are 1570 // indistinguishable conversion sequences unless one of the 1571 // following rules apply: (C++ 13.3.3.2p3): 1572 if (ICS1.ConversionKind == ImplicitConversionSequence::StandardConversion) 1573 return CompareStandardConversionSequences(ICS1.Standard, ICS2.Standard); 1574 else if (ICS1.ConversionKind == 1575 ImplicitConversionSequence::UserDefinedConversion) { 1576 // User-defined conversion sequence U1 is a better conversion 1577 // sequence than another user-defined conversion sequence U2 if 1578 // they contain the same user-defined conversion function or 1579 // constructor and if the second standard conversion sequence of 1580 // U1 is better than the second standard conversion sequence of 1581 // U2 (C++ 13.3.3.2p3). 1582 if (ICS1.UserDefined.ConversionFunction == 1583 ICS2.UserDefined.ConversionFunction) 1584 return CompareStandardConversionSequences(ICS1.UserDefined.After, 1585 ICS2.UserDefined.After); 1586 } 1587 1588 return ImplicitConversionSequence::Indistinguishable; 1589} 1590 1591/// CompareStandardConversionSequences - Compare two standard 1592/// conversion sequences to determine whether one is better than the 1593/// other or if they are indistinguishable (C++ 13.3.3.2p3). 1594ImplicitConversionSequence::CompareKind 1595Sema::CompareStandardConversionSequences(const StandardConversionSequence& SCS1, 1596 const StandardConversionSequence& SCS2) 1597{ 1598 // Standard conversion sequence S1 is a better conversion sequence 1599 // than standard conversion sequence S2 if (C++ 13.3.3.2p3): 1600 1601 // -- S1 is a proper subsequence of S2 (comparing the conversion 1602 // sequences in the canonical form defined by 13.3.3.1.1, 1603 // excluding any Lvalue Transformation; the identity conversion 1604 // sequence is considered to be a subsequence of any 1605 // non-identity conversion sequence) or, if not that, 1606 if (SCS1.Second == SCS2.Second && SCS1.Third == SCS2.Third) 1607 // Neither is a proper subsequence of the other. Do nothing. 1608 ; 1609 else if ((SCS1.Second == ICK_Identity && SCS1.Third == SCS2.Third) || 1610 (SCS1.Third == ICK_Identity && SCS1.Second == SCS2.Second) || 1611 (SCS1.Second == ICK_Identity && 1612 SCS1.Third == ICK_Identity)) 1613 // SCS1 is a proper subsequence of SCS2. 1614 return ImplicitConversionSequence::Better; 1615 else if ((SCS2.Second == ICK_Identity && SCS2.Third == SCS1.Third) || 1616 (SCS2.Third == ICK_Identity && SCS2.Second == SCS1.Second) || 1617 (SCS2.Second == ICK_Identity && 1618 SCS2.Third == ICK_Identity)) 1619 // SCS2 is a proper subsequence of SCS1. 1620 return ImplicitConversionSequence::Worse; 1621 1622 // -- the rank of S1 is better than the rank of S2 (by the rules 1623 // defined below), or, if not that, 1624 ImplicitConversionRank Rank1 = SCS1.getRank(); 1625 ImplicitConversionRank Rank2 = SCS2.getRank(); 1626 if (Rank1 < Rank2) 1627 return ImplicitConversionSequence::Better; 1628 else if (Rank2 < Rank1) 1629 return ImplicitConversionSequence::Worse; 1630 1631 // (C++ 13.3.3.2p4): Two conversion sequences with the same rank 1632 // are indistinguishable unless one of the following rules 1633 // applies: 1634 1635 // A conversion that is not a conversion of a pointer, or 1636 // pointer to member, to bool is better than another conversion 1637 // that is such a conversion. 1638 if (SCS1.isPointerConversionToBool() != SCS2.isPointerConversionToBool()) 1639 return SCS2.isPointerConversionToBool() 1640 ? ImplicitConversionSequence::Better 1641 : ImplicitConversionSequence::Worse; 1642 1643 // C++ [over.ics.rank]p4b2: 1644 // 1645 // If class B is derived directly or indirectly from class A, 1646 // conversion of B* to A* is better than conversion of B* to 1647 // void*, and conversion of A* to void* is better than conversion 1648 // of B* to void*. 1649 bool SCS1ConvertsToVoid 1650 = SCS1.isPointerConversionToVoidPointer(Context); 1651 bool SCS2ConvertsToVoid 1652 = SCS2.isPointerConversionToVoidPointer(Context); 1653 if (SCS1ConvertsToVoid != SCS2ConvertsToVoid) { 1654 // Exactly one of the conversion sequences is a conversion to 1655 // a void pointer; it's the worse conversion. 1656 return SCS2ConvertsToVoid ? ImplicitConversionSequence::Better 1657 : ImplicitConversionSequence::Worse; 1658 } else if (!SCS1ConvertsToVoid && !SCS2ConvertsToVoid) { 1659 // Neither conversion sequence converts to a void pointer; compare 1660 // their derived-to-base conversions. 1661 if (ImplicitConversionSequence::CompareKind DerivedCK 1662 = CompareDerivedToBaseConversions(SCS1, SCS2)) 1663 return DerivedCK; 1664 } else if (SCS1ConvertsToVoid && SCS2ConvertsToVoid) { 1665 // Both conversion sequences are conversions to void 1666 // pointers. Compare the source types to determine if there's an 1667 // inheritance relationship in their sources. 1668 QualType FromType1 = QualType::getFromOpaquePtr(SCS1.FromTypePtr); 1669 QualType FromType2 = QualType::getFromOpaquePtr(SCS2.FromTypePtr); 1670 1671 // Adjust the types we're converting from via the array-to-pointer 1672 // conversion, if we need to. 1673 if (SCS1.First == ICK_Array_To_Pointer) 1674 FromType1 = Context.getArrayDecayedType(FromType1); 1675 if (SCS2.First == ICK_Array_To_Pointer) 1676 FromType2 = Context.getArrayDecayedType(FromType2); 1677 1678 QualType FromPointee1 1679 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1680 QualType FromPointee2 1681 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1682 1683 if (IsDerivedFrom(FromPointee2, FromPointee1)) 1684 return ImplicitConversionSequence::Better; 1685 else if (IsDerivedFrom(FromPointee1, FromPointee2)) 1686 return ImplicitConversionSequence::Worse; 1687 1688 // Objective-C++: If one interface is more specific than the 1689 // other, it is the better one. 1690 const ObjCInterfaceType* FromIface1 = FromPointee1->getAs<ObjCInterfaceType>(); 1691 const ObjCInterfaceType* FromIface2 = FromPointee2->getAs<ObjCInterfaceType>(); 1692 if (FromIface1 && FromIface1) { 1693 if (Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 1694 return ImplicitConversionSequence::Better; 1695 else if (Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 1696 return ImplicitConversionSequence::Worse; 1697 } 1698 } 1699 1700 // Compare based on qualification conversions (C++ 13.3.3.2p3, 1701 // bullet 3). 1702 if (ImplicitConversionSequence::CompareKind QualCK 1703 = CompareQualificationConversions(SCS1, SCS2)) 1704 return QualCK; 1705 1706 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding) { 1707 // C++0x [over.ics.rank]p3b4: 1708 // -- S1 and S2 are reference bindings (8.5.3) and neither refers to an 1709 // implicit object parameter of a non-static member function declared 1710 // without a ref-qualifier, and S1 binds an rvalue reference to an 1711 // rvalue and S2 binds an lvalue reference. 1712 // FIXME: We don't know if we're dealing with the implicit object parameter, 1713 // or if the member function in this case has a ref qualifier. 1714 // (Of course, we don't have ref qualifiers yet.) 1715 if (SCS1.RRefBinding != SCS2.RRefBinding) 1716 return SCS1.RRefBinding ? ImplicitConversionSequence::Better 1717 : ImplicitConversionSequence::Worse; 1718 1719 // C++ [over.ics.rank]p3b4: 1720 // -- S1 and S2 are reference bindings (8.5.3), and the types to 1721 // which the references refer are the same type except for 1722 // top-level cv-qualifiers, and the type to which the reference 1723 // initialized by S2 refers is more cv-qualified than the type 1724 // to which the reference initialized by S1 refers. 1725 QualType T1 = QualType::getFromOpaquePtr(SCS1.ToTypePtr); 1726 QualType T2 = QualType::getFromOpaquePtr(SCS2.ToTypePtr); 1727 T1 = Context.getCanonicalType(T1); 1728 T2 = Context.getCanonicalType(T2); 1729 if (T1.getUnqualifiedType() == T2.getUnqualifiedType()) { 1730 if (T2.isMoreQualifiedThan(T1)) 1731 return ImplicitConversionSequence::Better; 1732 else if (T1.isMoreQualifiedThan(T2)) 1733 return ImplicitConversionSequence::Worse; 1734 } 1735 } 1736 1737 return ImplicitConversionSequence::Indistinguishable; 1738} 1739 1740/// CompareQualificationConversions - Compares two standard conversion 1741/// sequences to determine whether they can be ranked based on their 1742/// qualification conversions (C++ 13.3.3.2p3 bullet 3). 1743ImplicitConversionSequence::CompareKind 1744Sema::CompareQualificationConversions(const StandardConversionSequence& SCS1, 1745 const StandardConversionSequence& SCS2) { 1746 // C++ 13.3.3.2p3: 1747 // -- S1 and S2 differ only in their qualification conversion and 1748 // yield similar types T1 and T2 (C++ 4.4), respectively, and the 1749 // cv-qualification signature of type T1 is a proper subset of 1750 // the cv-qualification signature of type T2, and S1 is not the 1751 // deprecated string literal array-to-pointer conversion (4.2). 1752 if (SCS1.First != SCS2.First || SCS1.Second != SCS2.Second || 1753 SCS1.Third != SCS2.Third || SCS1.Third != ICK_Qualification) 1754 return ImplicitConversionSequence::Indistinguishable; 1755 1756 // FIXME: the example in the standard doesn't use a qualification 1757 // conversion (!) 1758 QualType T1 = QualType::getFromOpaquePtr(SCS1.ToTypePtr); 1759 QualType T2 = QualType::getFromOpaquePtr(SCS2.ToTypePtr); 1760 T1 = Context.getCanonicalType(T1); 1761 T2 = Context.getCanonicalType(T2); 1762 1763 // If the types are the same, we won't learn anything by unwrapped 1764 // them. 1765 if (T1.getUnqualifiedType() == T2.getUnqualifiedType()) 1766 return ImplicitConversionSequence::Indistinguishable; 1767 1768 ImplicitConversionSequence::CompareKind Result 1769 = ImplicitConversionSequence::Indistinguishable; 1770 while (UnwrapSimilarPointerTypes(T1, T2)) { 1771 // Within each iteration of the loop, we check the qualifiers to 1772 // determine if this still looks like a qualification 1773 // conversion. Then, if all is well, we unwrap one more level of 1774 // pointers or pointers-to-members and do it all again 1775 // until there are no more pointers or pointers-to-members left 1776 // to unwrap. This essentially mimics what 1777 // IsQualificationConversion does, but here we're checking for a 1778 // strict subset of qualifiers. 1779 if (T1.getCVRQualifiers() == T2.getCVRQualifiers()) 1780 // The qualifiers are the same, so this doesn't tell us anything 1781 // about how the sequences rank. 1782 ; 1783 else if (T2.isMoreQualifiedThan(T1)) { 1784 // T1 has fewer qualifiers, so it could be the better sequence. 1785 if (Result == ImplicitConversionSequence::Worse) 1786 // Neither has qualifiers that are a subset of the other's 1787 // qualifiers. 1788 return ImplicitConversionSequence::Indistinguishable; 1789 1790 Result = ImplicitConversionSequence::Better; 1791 } else if (T1.isMoreQualifiedThan(T2)) { 1792 // T2 has fewer qualifiers, so it could be the better sequence. 1793 if (Result == ImplicitConversionSequence::Better) 1794 // Neither has qualifiers that are a subset of the other's 1795 // qualifiers. 1796 return ImplicitConversionSequence::Indistinguishable; 1797 1798 Result = ImplicitConversionSequence::Worse; 1799 } else { 1800 // Qualifiers are disjoint. 1801 return ImplicitConversionSequence::Indistinguishable; 1802 } 1803 1804 // If the types after this point are equivalent, we're done. 1805 if (T1.getUnqualifiedType() == T2.getUnqualifiedType()) 1806 break; 1807 } 1808 1809 // Check that the winning standard conversion sequence isn't using 1810 // the deprecated string literal array to pointer conversion. 1811 switch (Result) { 1812 case ImplicitConversionSequence::Better: 1813 if (SCS1.Deprecated) 1814 Result = ImplicitConversionSequence::Indistinguishable; 1815 break; 1816 1817 case ImplicitConversionSequence::Indistinguishable: 1818 break; 1819 1820 case ImplicitConversionSequence::Worse: 1821 if (SCS2.Deprecated) 1822 Result = ImplicitConversionSequence::Indistinguishable; 1823 break; 1824 } 1825 1826 return Result; 1827} 1828 1829/// CompareDerivedToBaseConversions - Compares two standard conversion 1830/// sequences to determine whether they can be ranked based on their 1831/// various kinds of derived-to-base conversions (C++ 1832/// [over.ics.rank]p4b3). As part of these checks, we also look at 1833/// conversions between Objective-C interface types. 1834ImplicitConversionSequence::CompareKind 1835Sema::CompareDerivedToBaseConversions(const StandardConversionSequence& SCS1, 1836 const StandardConversionSequence& SCS2) { 1837 QualType FromType1 = QualType::getFromOpaquePtr(SCS1.FromTypePtr); 1838 QualType ToType1 = QualType::getFromOpaquePtr(SCS1.ToTypePtr); 1839 QualType FromType2 = QualType::getFromOpaquePtr(SCS2.FromTypePtr); 1840 QualType ToType2 = QualType::getFromOpaquePtr(SCS2.ToTypePtr); 1841 1842 // Adjust the types we're converting from via the array-to-pointer 1843 // conversion, if we need to. 1844 if (SCS1.First == ICK_Array_To_Pointer) 1845 FromType1 = Context.getArrayDecayedType(FromType1); 1846 if (SCS2.First == ICK_Array_To_Pointer) 1847 FromType2 = Context.getArrayDecayedType(FromType2); 1848 1849 // Canonicalize all of the types. 1850 FromType1 = Context.getCanonicalType(FromType1); 1851 ToType1 = Context.getCanonicalType(ToType1); 1852 FromType2 = Context.getCanonicalType(FromType2); 1853 ToType2 = Context.getCanonicalType(ToType2); 1854 1855 // C++ [over.ics.rank]p4b3: 1856 // 1857 // If class B is derived directly or indirectly from class A and 1858 // class C is derived directly or indirectly from B, 1859 // 1860 // For Objective-C, we let A, B, and C also be Objective-C 1861 // interfaces. 1862 1863 // Compare based on pointer conversions. 1864 if (SCS1.Second == ICK_Pointer_Conversion && 1865 SCS2.Second == ICK_Pointer_Conversion && 1866 /*FIXME: Remove if Objective-C id conversions get their own rank*/ 1867 FromType1->isPointerType() && FromType2->isPointerType() && 1868 ToType1->isPointerType() && ToType2->isPointerType()) { 1869 QualType FromPointee1 1870 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1871 QualType ToPointee1 1872 = ToType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1873 QualType FromPointee2 1874 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1875 QualType ToPointee2 1876 = ToType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1877 1878 const ObjCInterfaceType* FromIface1 = FromPointee1->getAs<ObjCInterfaceType>(); 1879 const ObjCInterfaceType* FromIface2 = FromPointee2->getAs<ObjCInterfaceType>(); 1880 const ObjCInterfaceType* ToIface1 = ToPointee1->getAs<ObjCInterfaceType>(); 1881 const ObjCInterfaceType* ToIface2 = ToPointee2->getAs<ObjCInterfaceType>(); 1882 1883 // -- conversion of C* to B* is better than conversion of C* to A*, 1884 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 1885 if (IsDerivedFrom(ToPointee1, ToPointee2)) 1886 return ImplicitConversionSequence::Better; 1887 else if (IsDerivedFrom(ToPointee2, ToPointee1)) 1888 return ImplicitConversionSequence::Worse; 1889 1890 if (ToIface1 && ToIface2) { 1891 if (Context.canAssignObjCInterfaces(ToIface2, ToIface1)) 1892 return ImplicitConversionSequence::Better; 1893 else if (Context.canAssignObjCInterfaces(ToIface1, ToIface2)) 1894 return ImplicitConversionSequence::Worse; 1895 } 1896 } 1897 1898 // -- conversion of B* to A* is better than conversion of C* to A*, 1899 if (FromPointee1 != FromPointee2 && ToPointee1 == ToPointee2) { 1900 if (IsDerivedFrom(FromPointee2, FromPointee1)) 1901 return ImplicitConversionSequence::Better; 1902 else if (IsDerivedFrom(FromPointee1, FromPointee2)) 1903 return ImplicitConversionSequence::Worse; 1904 1905 if (FromIface1 && FromIface2) { 1906 if (Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 1907 return ImplicitConversionSequence::Better; 1908 else if (Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 1909 return ImplicitConversionSequence::Worse; 1910 } 1911 } 1912 } 1913 1914 // Compare based on reference bindings. 1915 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding && 1916 SCS1.Second == ICK_Derived_To_Base) { 1917 // -- binding of an expression of type C to a reference of type 1918 // B& is better than binding an expression of type C to a 1919 // reference of type A&, 1920 if (FromType1.getUnqualifiedType() == FromType2.getUnqualifiedType() && 1921 ToType1.getUnqualifiedType() != ToType2.getUnqualifiedType()) { 1922 if (IsDerivedFrom(ToType1, ToType2)) 1923 return ImplicitConversionSequence::Better; 1924 else if (IsDerivedFrom(ToType2, ToType1)) 1925 return ImplicitConversionSequence::Worse; 1926 } 1927 1928 // -- binding of an expression of type B to a reference of type 1929 // A& is better than binding an expression of type C to a 1930 // reference of type A&, 1931 if (FromType1.getUnqualifiedType() != FromType2.getUnqualifiedType() && 1932 ToType1.getUnqualifiedType() == ToType2.getUnqualifiedType()) { 1933 if (IsDerivedFrom(FromType2, FromType1)) 1934 return ImplicitConversionSequence::Better; 1935 else if (IsDerivedFrom(FromType1, FromType2)) 1936 return ImplicitConversionSequence::Worse; 1937 } 1938 } 1939 1940 1941 // FIXME: conversion of A::* to B::* is better than conversion of 1942 // A::* to C::*, 1943 1944 // FIXME: conversion of B::* to C::* is better than conversion of 1945 // A::* to C::*, and 1946 1947 if (SCS1.CopyConstructor && SCS2.CopyConstructor && 1948 SCS1.Second == ICK_Derived_To_Base) { 1949 // -- conversion of C to B is better than conversion of C to A, 1950 if (FromType1.getUnqualifiedType() == FromType2.getUnqualifiedType() && 1951 ToType1.getUnqualifiedType() != ToType2.getUnqualifiedType()) { 1952 if (IsDerivedFrom(ToType1, ToType2)) 1953 return ImplicitConversionSequence::Better; 1954 else if (IsDerivedFrom(ToType2, ToType1)) 1955 return ImplicitConversionSequence::Worse; 1956 } 1957 1958 // -- conversion of B to A is better than conversion of C to A. 1959 if (FromType1.getUnqualifiedType() != FromType2.getUnqualifiedType() && 1960 ToType1.getUnqualifiedType() == ToType2.getUnqualifiedType()) { 1961 if (IsDerivedFrom(FromType2, FromType1)) 1962 return ImplicitConversionSequence::Better; 1963 else if (IsDerivedFrom(FromType1, FromType2)) 1964 return ImplicitConversionSequence::Worse; 1965 } 1966 } 1967 1968 return ImplicitConversionSequence::Indistinguishable; 1969} 1970 1971/// TryCopyInitialization - Try to copy-initialize a value of type 1972/// ToType from the expression From. Return the implicit conversion 1973/// sequence required to pass this argument, which may be a bad 1974/// conversion sequence (meaning that the argument cannot be passed to 1975/// a parameter of this type). If @p SuppressUserConversions, then we 1976/// do not permit any user-defined conversion sequences. If @p ForceRValue, 1977/// then we treat @p From as an rvalue, even if it is an lvalue. 1978ImplicitConversionSequence 1979Sema::TryCopyInitialization(Expr *From, QualType ToType, 1980 bool SuppressUserConversions, bool ForceRValue, 1981 bool InOverloadResolution) { 1982 if (ToType->isReferenceType()) { 1983 ImplicitConversionSequence ICS; 1984 CheckReferenceInit(From, ToType, 1985 /*FIXME:*/From->getLocStart(), 1986 SuppressUserConversions, 1987 /*AllowExplicit=*/false, 1988 ForceRValue, 1989 &ICS); 1990 return ICS; 1991 } else { 1992 return TryImplicitConversion(From, ToType, 1993 SuppressUserConversions, 1994 /*AllowExplicit=*/false, 1995 ForceRValue, 1996 InOverloadResolution); 1997 } 1998} 1999 2000/// PerformCopyInitialization - Copy-initialize an object of type @p ToType with 2001/// the expression @p From. Returns true (and emits a diagnostic) if there was 2002/// an error, returns false if the initialization succeeded. Elidable should 2003/// be true when the copy may be elided (C++ 12.8p15). Overload resolution works 2004/// differently in C++0x for this case. 2005bool Sema::PerformCopyInitialization(Expr *&From, QualType ToType, 2006 const char* Flavor, bool Elidable) { 2007 if (!getLangOptions().CPlusPlus) { 2008 // In C, argument passing is the same as performing an assignment. 2009 QualType FromType = From->getType(); 2010 2011 AssignConvertType ConvTy = 2012 CheckSingleAssignmentConstraints(ToType, From); 2013 if (ConvTy != Compatible && 2014 CheckTransparentUnionArgumentConstraints(ToType, From) == Compatible) 2015 ConvTy = Compatible; 2016 2017 return DiagnoseAssignmentResult(ConvTy, From->getLocStart(), ToType, 2018 FromType, From, Flavor); 2019 } 2020 2021 if (ToType->isReferenceType()) 2022 return CheckReferenceInit(From, ToType, 2023 /*FIXME:*/From->getLocStart(), 2024 /*SuppressUserConversions=*/false, 2025 /*AllowExplicit=*/false, 2026 /*ForceRValue=*/false); 2027 2028 if (!PerformImplicitConversion(From, ToType, Flavor, 2029 /*AllowExplicit=*/false, Elidable)) 2030 return false; 2031 if (!DiagnoseAmbiguousUserDefinedConversion(From, ToType)) 2032 return Diag(From->getSourceRange().getBegin(), 2033 diag::err_typecheck_convert_incompatible) 2034 << ToType << From->getType() << Flavor << From->getSourceRange(); 2035 return true; 2036} 2037 2038/// TryObjectArgumentInitialization - Try to initialize the object 2039/// parameter of the given member function (@c Method) from the 2040/// expression @p From. 2041ImplicitConversionSequence 2042Sema::TryObjectArgumentInitialization(Expr *From, CXXMethodDecl *Method) { 2043 QualType ClassType = Context.getTypeDeclType(Method->getParent()); 2044 QualType ImplicitParamType 2045 = Context.getCVRQualifiedType(ClassType, Method->getTypeQualifiers()); 2046 2047 // Set up the conversion sequence as a "bad" conversion, to allow us 2048 // to exit early. 2049 ImplicitConversionSequence ICS; 2050 ICS.Standard.setAsIdentityConversion(); 2051 ICS.ConversionKind = ImplicitConversionSequence::BadConversion; 2052 2053 // We need to have an object of class type. 2054 QualType FromType = From->getType(); 2055 if (const PointerType *PT = FromType->getAs<PointerType>()) 2056 FromType = PT->getPointeeType(); 2057 2058 assert(FromType->isRecordType()); 2059 2060 // The implicit object parmeter is has the type "reference to cv X", 2061 // where X is the class of which the function is a member 2062 // (C++ [over.match.funcs]p4). However, when finding an implicit 2063 // conversion sequence for the argument, we are not allowed to 2064 // create temporaries or perform user-defined conversions 2065 // (C++ [over.match.funcs]p5). We perform a simplified version of 2066 // reference binding here, that allows class rvalues to bind to 2067 // non-constant references. 2068 2069 // First check the qualifiers. We don't care about lvalue-vs-rvalue 2070 // with the implicit object parameter (C++ [over.match.funcs]p5). 2071 QualType FromTypeCanon = Context.getCanonicalType(FromType); 2072 if (ImplicitParamType.getCVRQualifiers() != FromType.getCVRQualifiers() && 2073 !ImplicitParamType.isAtLeastAsQualifiedAs(FromType)) 2074 return ICS; 2075 2076 // Check that we have either the same type or a derived type. It 2077 // affects the conversion rank. 2078 QualType ClassTypeCanon = Context.getCanonicalType(ClassType); 2079 if (ClassTypeCanon == FromTypeCanon.getUnqualifiedType()) 2080 ICS.Standard.Second = ICK_Identity; 2081 else if (IsDerivedFrom(FromType, ClassType)) 2082 ICS.Standard.Second = ICK_Derived_To_Base; 2083 else 2084 return ICS; 2085 2086 // Success. Mark this as a reference binding. 2087 ICS.ConversionKind = ImplicitConversionSequence::StandardConversion; 2088 ICS.Standard.FromTypePtr = FromType.getAsOpaquePtr(); 2089 ICS.Standard.ToTypePtr = ImplicitParamType.getAsOpaquePtr(); 2090 ICS.Standard.ReferenceBinding = true; 2091 ICS.Standard.DirectBinding = true; 2092 ICS.Standard.RRefBinding = false; 2093 return ICS; 2094} 2095 2096/// PerformObjectArgumentInitialization - Perform initialization of 2097/// the implicit object parameter for the given Method with the given 2098/// expression. 2099bool 2100Sema::PerformObjectArgumentInitialization(Expr *&From, CXXMethodDecl *Method) { 2101 QualType FromRecordType, DestType; 2102 QualType ImplicitParamRecordType = 2103 Method->getThisType(Context)->getAs<PointerType>()->getPointeeType(); 2104 2105 if (const PointerType *PT = From->getType()->getAs<PointerType>()) { 2106 FromRecordType = PT->getPointeeType(); 2107 DestType = Method->getThisType(Context); 2108 } else { 2109 FromRecordType = From->getType(); 2110 DestType = ImplicitParamRecordType; 2111 } 2112 2113 ImplicitConversionSequence ICS 2114 = TryObjectArgumentInitialization(From, Method); 2115 if (ICS.ConversionKind == ImplicitConversionSequence::BadConversion) 2116 return Diag(From->getSourceRange().getBegin(), 2117 diag::err_implicit_object_parameter_init) 2118 << ImplicitParamRecordType << FromRecordType << From->getSourceRange(); 2119 2120 if (ICS.Standard.Second == ICK_Derived_To_Base && 2121 CheckDerivedToBaseConversion(FromRecordType, 2122 ImplicitParamRecordType, 2123 From->getSourceRange().getBegin(), 2124 From->getSourceRange())) 2125 return true; 2126 2127 ImpCastExprToType(From, DestType, CastExpr::CK_DerivedToBase, 2128 /*isLvalue=*/true); 2129 return false; 2130} 2131 2132/// TryContextuallyConvertToBool - Attempt to contextually convert the 2133/// expression From to bool (C++0x [conv]p3). 2134ImplicitConversionSequence Sema::TryContextuallyConvertToBool(Expr *From) { 2135 return TryImplicitConversion(From, Context.BoolTy, 2136 // FIXME: Are these flags correct? 2137 /*SuppressUserConversions=*/false, 2138 /*AllowExplicit=*/true, 2139 /*ForceRValue=*/false, 2140 /*InOverloadResolution=*/false); 2141} 2142 2143/// PerformContextuallyConvertToBool - Perform a contextual conversion 2144/// of the expression From to bool (C++0x [conv]p3). 2145bool Sema::PerformContextuallyConvertToBool(Expr *&From) { 2146 ImplicitConversionSequence ICS = TryContextuallyConvertToBool(From); 2147 if (!PerformImplicitConversion(From, Context.BoolTy, ICS, "converting")) 2148 return false; 2149 2150 if (!DiagnoseAmbiguousUserDefinedConversion(From, Context.BoolTy)) 2151 return Diag(From->getSourceRange().getBegin(), 2152 diag::err_typecheck_bool_condition) 2153 << From->getType() << From->getSourceRange(); 2154 return true; 2155} 2156 2157/// AddOverloadCandidate - Adds the given function to the set of 2158/// candidate functions, using the given function call arguments. If 2159/// @p SuppressUserConversions, then don't allow user-defined 2160/// conversions via constructors or conversion operators. 2161/// If @p ForceRValue, treat all arguments as rvalues. This is a slightly 2162/// hacky way to implement the overloading rules for elidable copy 2163/// initialization in C++0x (C++0x 12.8p15). 2164/// 2165/// \para PartialOverloading true if we are performing "partial" overloading 2166/// based on an incomplete set of function arguments. This feature is used by 2167/// code completion. 2168void 2169Sema::AddOverloadCandidate(FunctionDecl *Function, 2170 Expr **Args, unsigned NumArgs, 2171 OverloadCandidateSet& CandidateSet, 2172 bool SuppressUserConversions, 2173 bool ForceRValue, 2174 bool PartialOverloading) { 2175 const FunctionProtoType* Proto 2176 = dyn_cast<FunctionProtoType>(Function->getType()->getAs<FunctionType>()); 2177 assert(Proto && "Functions without a prototype cannot be overloaded"); 2178 assert(!isa<CXXConversionDecl>(Function) && 2179 "Use AddConversionCandidate for conversion functions"); 2180 assert(!Function->getDescribedFunctionTemplate() && 2181 "Use AddTemplateOverloadCandidate for function templates"); 2182 2183 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Function)) { 2184 if (!isa<CXXConstructorDecl>(Method)) { 2185 // If we get here, it's because we're calling a member function 2186 // that is named without a member access expression (e.g., 2187 // "this->f") that was either written explicitly or created 2188 // implicitly. This can happen with a qualified call to a member 2189 // function, e.g., X::f(). We use a NULL object as the implied 2190 // object argument (C++ [over.call.func]p3). 2191 AddMethodCandidate(Method, 0, Args, NumArgs, CandidateSet, 2192 SuppressUserConversions, ForceRValue); 2193 return; 2194 } 2195 // We treat a constructor like a non-member function, since its object 2196 // argument doesn't participate in overload resolution. 2197 } 2198 2199 if (!CandidateSet.isNewCandidate(Function)) 2200 return; 2201 2202 // Add this candidate 2203 CandidateSet.push_back(OverloadCandidate()); 2204 OverloadCandidate& Candidate = CandidateSet.back(); 2205 Candidate.Function = Function; 2206 Candidate.Viable = true; 2207 Candidate.IsSurrogate = false; 2208 Candidate.IgnoreObjectArgument = false; 2209 2210 unsigned NumArgsInProto = Proto->getNumArgs(); 2211 2212 // (C++ 13.3.2p2): A candidate function having fewer than m 2213 // parameters is viable only if it has an ellipsis in its parameter 2214 // list (8.3.5). 2215 if ((NumArgs + (PartialOverloading && NumArgs)) > NumArgsInProto && 2216 !Proto->isVariadic()) { 2217 Candidate.Viable = false; 2218 return; 2219 } 2220 2221 // (C++ 13.3.2p2): A candidate function having more than m parameters 2222 // is viable only if the (m+1)st parameter has a default argument 2223 // (8.3.6). For the purposes of overload resolution, the 2224 // parameter list is truncated on the right, so that there are 2225 // exactly m parameters. 2226 unsigned MinRequiredArgs = Function->getMinRequiredArguments(); 2227 if (NumArgs < MinRequiredArgs && !PartialOverloading) { 2228 // Not enough arguments. 2229 Candidate.Viable = false; 2230 return; 2231 } 2232 2233 // Determine the implicit conversion sequences for each of the 2234 // arguments. 2235 Candidate.Conversions.resize(NumArgs); 2236 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2237 if (ArgIdx < NumArgsInProto) { 2238 // (C++ 13.3.2p3): for F to be a viable function, there shall 2239 // exist for each argument an implicit conversion sequence 2240 // (13.3.3.1) that converts that argument to the corresponding 2241 // parameter of F. 2242 QualType ParamType = Proto->getArgType(ArgIdx); 2243 Candidate.Conversions[ArgIdx] 2244 = TryCopyInitialization(Args[ArgIdx], ParamType, 2245 SuppressUserConversions, ForceRValue, 2246 /*InOverloadResolution=*/true); 2247 if (Candidate.Conversions[ArgIdx].ConversionKind 2248 == ImplicitConversionSequence::BadConversion) { 2249 // 13.3.3.1-p10 If several different sequences of conversions exist that 2250 // each convert the argument to the parameter type, the implicit conversion 2251 // sequence associated with the parameter is defined to be the unique conversion 2252 // sequence designated the ambiguous conversion sequence. For the purpose of 2253 // ranking implicit conversion sequences as described in 13.3.3.2, the ambiguous 2254 // conversion sequence is treated as a user-defined sequence that is 2255 // indistinguishable from any other user-defined conversion sequence 2256 if (!Candidate.Conversions[ArgIdx].ConversionFunctionSet.empty()) { 2257 Candidate.Conversions[ArgIdx].ConversionKind = 2258 ImplicitConversionSequence::UserDefinedConversion; 2259 // Set the conversion function to one of them. As due to ambiguity, 2260 // they carry the same weight and is needed for overload resolution 2261 // later. 2262 Candidate.Conversions[ArgIdx].UserDefined.ConversionFunction = 2263 Candidate.Conversions[ArgIdx].ConversionFunctionSet[0]; 2264 } 2265 else { 2266 Candidate.Viable = false; 2267 break; 2268 } 2269 } 2270 } else { 2271 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2272 // argument for which there is no corresponding parameter is 2273 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2274 Candidate.Conversions[ArgIdx].ConversionKind 2275 = ImplicitConversionSequence::EllipsisConversion; 2276 } 2277 } 2278} 2279 2280/// \brief Add all of the function declarations in the given function set to 2281/// the overload canddiate set. 2282void Sema::AddFunctionCandidates(const FunctionSet &Functions, 2283 Expr **Args, unsigned NumArgs, 2284 OverloadCandidateSet& CandidateSet, 2285 bool SuppressUserConversions) { 2286 for (FunctionSet::const_iterator F = Functions.begin(), 2287 FEnd = Functions.end(); 2288 F != FEnd; ++F) { 2289 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*F)) { 2290 if (isa<CXXMethodDecl>(FD) && !cast<CXXMethodDecl>(FD)->isStatic()) 2291 AddMethodCandidate(cast<CXXMethodDecl>(FD), 2292 Args[0], Args + 1, NumArgs - 1, 2293 CandidateSet, SuppressUserConversions); 2294 else 2295 AddOverloadCandidate(FD, Args, NumArgs, CandidateSet, 2296 SuppressUserConversions); 2297 } else { 2298 FunctionTemplateDecl *FunTmpl = cast<FunctionTemplateDecl>(*F); 2299 if (isa<CXXMethodDecl>(FunTmpl->getTemplatedDecl()) && 2300 !cast<CXXMethodDecl>(FunTmpl->getTemplatedDecl())->isStatic()) 2301 AddMethodTemplateCandidate(FunTmpl, 2302 /*FIXME: explicit args */false, 0, 0, 2303 Args[0], Args + 1, NumArgs - 1, 2304 CandidateSet, 2305 SuppressUserConversions); 2306 else 2307 AddTemplateOverloadCandidate(FunTmpl, 2308 /*FIXME: explicit args */false, 0, 0, 2309 Args, NumArgs, CandidateSet, 2310 SuppressUserConversions); 2311 } 2312 } 2313} 2314 2315/// AddMethodCandidate - Adds the given C++ member function to the set 2316/// of candidate functions, using the given function call arguments 2317/// and the object argument (@c Object). For example, in a call 2318/// @c o.f(a1,a2), @c Object will contain @c o and @c Args will contain 2319/// both @c a1 and @c a2. If @p SuppressUserConversions, then don't 2320/// allow user-defined conversions via constructors or conversion 2321/// operators. If @p ForceRValue, treat all arguments as rvalues. This is 2322/// a slightly hacky way to implement the overloading rules for elidable copy 2323/// initialization in C++0x (C++0x 12.8p15). 2324void 2325Sema::AddMethodCandidate(CXXMethodDecl *Method, Expr *Object, 2326 Expr **Args, unsigned NumArgs, 2327 OverloadCandidateSet& CandidateSet, 2328 bool SuppressUserConversions, bool ForceRValue) { 2329 const FunctionProtoType* Proto 2330 = dyn_cast<FunctionProtoType>(Method->getType()->getAs<FunctionType>()); 2331 assert(Proto && "Methods without a prototype cannot be overloaded"); 2332 assert(!isa<CXXConversionDecl>(Method) && 2333 "Use AddConversionCandidate for conversion functions"); 2334 assert(!isa<CXXConstructorDecl>(Method) && 2335 "Use AddOverloadCandidate for constructors"); 2336 2337 if (!CandidateSet.isNewCandidate(Method)) 2338 return; 2339 2340 // Add this candidate 2341 CandidateSet.push_back(OverloadCandidate()); 2342 OverloadCandidate& Candidate = CandidateSet.back(); 2343 Candidate.Function = Method; 2344 Candidate.IsSurrogate = false; 2345 Candidate.IgnoreObjectArgument = false; 2346 2347 unsigned NumArgsInProto = Proto->getNumArgs(); 2348 2349 // (C++ 13.3.2p2): A candidate function having fewer than m 2350 // parameters is viable only if it has an ellipsis in its parameter 2351 // list (8.3.5). 2352 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 2353 Candidate.Viable = false; 2354 return; 2355 } 2356 2357 // (C++ 13.3.2p2): A candidate function having more than m parameters 2358 // is viable only if the (m+1)st parameter has a default argument 2359 // (8.3.6). For the purposes of overload resolution, the 2360 // parameter list is truncated on the right, so that there are 2361 // exactly m parameters. 2362 unsigned MinRequiredArgs = Method->getMinRequiredArguments(); 2363 if (NumArgs < MinRequiredArgs) { 2364 // Not enough arguments. 2365 Candidate.Viable = false; 2366 return; 2367 } 2368 2369 Candidate.Viable = true; 2370 Candidate.Conversions.resize(NumArgs + 1); 2371 2372 if (Method->isStatic() || !Object) 2373 // The implicit object argument is ignored. 2374 Candidate.IgnoreObjectArgument = true; 2375 else { 2376 // Determine the implicit conversion sequence for the object 2377 // parameter. 2378 Candidate.Conversions[0] = TryObjectArgumentInitialization(Object, Method); 2379 if (Candidate.Conversions[0].ConversionKind 2380 == ImplicitConversionSequence::BadConversion) { 2381 Candidate.Viable = false; 2382 return; 2383 } 2384 } 2385 2386 // Determine the implicit conversion sequences for each of the 2387 // arguments. 2388 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2389 if (ArgIdx < NumArgsInProto) { 2390 // (C++ 13.3.2p3): for F to be a viable function, there shall 2391 // exist for each argument an implicit conversion sequence 2392 // (13.3.3.1) that converts that argument to the corresponding 2393 // parameter of F. 2394 QualType ParamType = Proto->getArgType(ArgIdx); 2395 Candidate.Conversions[ArgIdx + 1] 2396 = TryCopyInitialization(Args[ArgIdx], ParamType, 2397 SuppressUserConversions, ForceRValue, 2398 /*InOverloadResolution=*/true); 2399 if (Candidate.Conversions[ArgIdx + 1].ConversionKind 2400 == ImplicitConversionSequence::BadConversion) { 2401 Candidate.Viable = false; 2402 break; 2403 } 2404 } else { 2405 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2406 // argument for which there is no corresponding parameter is 2407 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2408 Candidate.Conversions[ArgIdx + 1].ConversionKind 2409 = ImplicitConversionSequence::EllipsisConversion; 2410 } 2411 } 2412} 2413 2414/// \brief Add a C++ member function template as a candidate to the candidate 2415/// set, using template argument deduction to produce an appropriate member 2416/// function template specialization. 2417void 2418Sema::AddMethodTemplateCandidate(FunctionTemplateDecl *MethodTmpl, 2419 bool HasExplicitTemplateArgs, 2420 const TemplateArgument *ExplicitTemplateArgs, 2421 unsigned NumExplicitTemplateArgs, 2422 Expr *Object, Expr **Args, unsigned NumArgs, 2423 OverloadCandidateSet& CandidateSet, 2424 bool SuppressUserConversions, 2425 bool ForceRValue) { 2426 if (!CandidateSet.isNewCandidate(MethodTmpl)) 2427 return; 2428 2429 // C++ [over.match.funcs]p7: 2430 // In each case where a candidate is a function template, candidate 2431 // function template specializations are generated using template argument 2432 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 2433 // candidate functions in the usual way.113) A given name can refer to one 2434 // or more function templates and also to a set of overloaded non-template 2435 // functions. In such a case, the candidate functions generated from each 2436 // function template are combined with the set of non-template candidate 2437 // functions. 2438 TemplateDeductionInfo Info(Context); 2439 FunctionDecl *Specialization = 0; 2440 if (TemplateDeductionResult Result 2441 = DeduceTemplateArguments(MethodTmpl, HasExplicitTemplateArgs, 2442 ExplicitTemplateArgs, NumExplicitTemplateArgs, 2443 Args, NumArgs, Specialization, Info)) { 2444 // FIXME: Record what happened with template argument deduction, so 2445 // that we can give the user a beautiful diagnostic. 2446 (void)Result; 2447 return; 2448 } 2449 2450 // Add the function template specialization produced by template argument 2451 // deduction as a candidate. 2452 assert(Specialization && "Missing member function template specialization?"); 2453 assert(isa<CXXMethodDecl>(Specialization) && 2454 "Specialization is not a member function?"); 2455 AddMethodCandidate(cast<CXXMethodDecl>(Specialization), Object, Args, NumArgs, 2456 CandidateSet, SuppressUserConversions, ForceRValue); 2457} 2458 2459/// \brief Add a C++ function template specialization as a candidate 2460/// in the candidate set, using template argument deduction to produce 2461/// an appropriate function template specialization. 2462void 2463Sema::AddTemplateOverloadCandidate(FunctionTemplateDecl *FunctionTemplate, 2464 bool HasExplicitTemplateArgs, 2465 const TemplateArgument *ExplicitTemplateArgs, 2466 unsigned NumExplicitTemplateArgs, 2467 Expr **Args, unsigned NumArgs, 2468 OverloadCandidateSet& CandidateSet, 2469 bool SuppressUserConversions, 2470 bool ForceRValue) { 2471 if (!CandidateSet.isNewCandidate(FunctionTemplate)) 2472 return; 2473 2474 // C++ [over.match.funcs]p7: 2475 // In each case where a candidate is a function template, candidate 2476 // function template specializations are generated using template argument 2477 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 2478 // candidate functions in the usual way.113) A given name can refer to one 2479 // or more function templates and also to a set of overloaded non-template 2480 // functions. In such a case, the candidate functions generated from each 2481 // function template are combined with the set of non-template candidate 2482 // functions. 2483 TemplateDeductionInfo Info(Context); 2484 FunctionDecl *Specialization = 0; 2485 if (TemplateDeductionResult Result 2486 = DeduceTemplateArguments(FunctionTemplate, HasExplicitTemplateArgs, 2487 ExplicitTemplateArgs, NumExplicitTemplateArgs, 2488 Args, NumArgs, Specialization, Info)) { 2489 // FIXME: Record what happened with template argument deduction, so 2490 // that we can give the user a beautiful diagnostic. 2491 (void)Result; 2492 return; 2493 } 2494 2495 // Add the function template specialization produced by template argument 2496 // deduction as a candidate. 2497 assert(Specialization && "Missing function template specialization?"); 2498 AddOverloadCandidate(Specialization, Args, NumArgs, CandidateSet, 2499 SuppressUserConversions, ForceRValue); 2500} 2501 2502/// AddConversionCandidate - Add a C++ conversion function as a 2503/// candidate in the candidate set (C++ [over.match.conv], 2504/// C++ [over.match.copy]). From is the expression we're converting from, 2505/// and ToType is the type that we're eventually trying to convert to 2506/// (which may or may not be the same type as the type that the 2507/// conversion function produces). 2508void 2509Sema::AddConversionCandidate(CXXConversionDecl *Conversion, 2510 Expr *From, QualType ToType, 2511 OverloadCandidateSet& CandidateSet) { 2512 assert(!Conversion->getDescribedFunctionTemplate() && 2513 "Conversion function templates use AddTemplateConversionCandidate"); 2514 2515 if (!CandidateSet.isNewCandidate(Conversion)) 2516 return; 2517 2518 // Add this candidate 2519 CandidateSet.push_back(OverloadCandidate()); 2520 OverloadCandidate& Candidate = CandidateSet.back(); 2521 Candidate.Function = Conversion; 2522 Candidate.IsSurrogate = false; 2523 Candidate.IgnoreObjectArgument = false; 2524 Candidate.FinalConversion.setAsIdentityConversion(); 2525 Candidate.FinalConversion.FromTypePtr 2526 = Conversion->getConversionType().getAsOpaquePtr(); 2527 Candidate.FinalConversion.ToTypePtr = ToType.getAsOpaquePtr(); 2528 2529 // Determine the implicit conversion sequence for the implicit 2530 // object parameter. 2531 Candidate.Viable = true; 2532 Candidate.Conversions.resize(1); 2533 Candidate.Conversions[0] = TryObjectArgumentInitialization(From, Conversion); 2534 // Conversion functions to a different type in the base class is visible in 2535 // the derived class. So, a derived to base conversion should not participate 2536 // in overload resolution. 2537 if (Candidate.Conversions[0].Standard.Second == ICK_Derived_To_Base) 2538 Candidate.Conversions[0].Standard.Second = ICK_Identity; 2539 if (Candidate.Conversions[0].ConversionKind 2540 == ImplicitConversionSequence::BadConversion) { 2541 Candidate.Viable = false; 2542 return; 2543 } 2544 2545 // To determine what the conversion from the result of calling the 2546 // conversion function to the type we're eventually trying to 2547 // convert to (ToType), we need to synthesize a call to the 2548 // conversion function and attempt copy initialization from it. This 2549 // makes sure that we get the right semantics with respect to 2550 // lvalues/rvalues and the type. Fortunately, we can allocate this 2551 // call on the stack and we don't need its arguments to be 2552 // well-formed. 2553 DeclRefExpr ConversionRef(Conversion, Conversion->getType(), 2554 SourceLocation()); 2555 ImplicitCastExpr ConversionFn(Context.getPointerType(Conversion->getType()), 2556 CastExpr::CK_Unknown, 2557 &ConversionRef, false); 2558 2559 // Note that it is safe to allocate CallExpr on the stack here because 2560 // there are 0 arguments (i.e., nothing is allocated using ASTContext's 2561 // allocator). 2562 CallExpr Call(Context, &ConversionFn, 0, 0, 2563 Conversion->getConversionType().getNonReferenceType(), 2564 SourceLocation()); 2565 ImplicitConversionSequence ICS = 2566 TryCopyInitialization(&Call, ToType, 2567 /*SuppressUserConversions=*/true, 2568 /*ForceRValue=*/false, 2569 /*InOverloadResolution=*/false); 2570 2571 switch (ICS.ConversionKind) { 2572 case ImplicitConversionSequence::StandardConversion: 2573 Candidate.FinalConversion = ICS.Standard; 2574 break; 2575 2576 case ImplicitConversionSequence::BadConversion: 2577 Candidate.Viable = false; 2578 break; 2579 2580 default: 2581 assert(false && 2582 "Can only end up with a standard conversion sequence or failure"); 2583 } 2584} 2585 2586/// \brief Adds a conversion function template specialization 2587/// candidate to the overload set, using template argument deduction 2588/// to deduce the template arguments of the conversion function 2589/// template from the type that we are converting to (C++ 2590/// [temp.deduct.conv]). 2591void 2592Sema::AddTemplateConversionCandidate(FunctionTemplateDecl *FunctionTemplate, 2593 Expr *From, QualType ToType, 2594 OverloadCandidateSet &CandidateSet) { 2595 assert(isa<CXXConversionDecl>(FunctionTemplate->getTemplatedDecl()) && 2596 "Only conversion function templates permitted here"); 2597 2598 if (!CandidateSet.isNewCandidate(FunctionTemplate)) 2599 return; 2600 2601 TemplateDeductionInfo Info(Context); 2602 CXXConversionDecl *Specialization = 0; 2603 if (TemplateDeductionResult Result 2604 = DeduceTemplateArguments(FunctionTemplate, ToType, 2605 Specialization, Info)) { 2606 // FIXME: Record what happened with template argument deduction, so 2607 // that we can give the user a beautiful diagnostic. 2608 (void)Result; 2609 return; 2610 } 2611 2612 // Add the conversion function template specialization produced by 2613 // template argument deduction as a candidate. 2614 assert(Specialization && "Missing function template specialization?"); 2615 AddConversionCandidate(Specialization, From, ToType, CandidateSet); 2616} 2617 2618/// AddSurrogateCandidate - Adds a "surrogate" candidate function that 2619/// converts the given @c Object to a function pointer via the 2620/// conversion function @c Conversion, and then attempts to call it 2621/// with the given arguments (C++ [over.call.object]p2-4). Proto is 2622/// the type of function that we'll eventually be calling. 2623void Sema::AddSurrogateCandidate(CXXConversionDecl *Conversion, 2624 const FunctionProtoType *Proto, 2625 Expr *Object, Expr **Args, unsigned NumArgs, 2626 OverloadCandidateSet& CandidateSet) { 2627 if (!CandidateSet.isNewCandidate(Conversion)) 2628 return; 2629 2630 CandidateSet.push_back(OverloadCandidate()); 2631 OverloadCandidate& Candidate = CandidateSet.back(); 2632 Candidate.Function = 0; 2633 Candidate.Surrogate = Conversion; 2634 Candidate.Viable = true; 2635 Candidate.IsSurrogate = true; 2636 Candidate.IgnoreObjectArgument = false; 2637 Candidate.Conversions.resize(NumArgs + 1); 2638 2639 // Determine the implicit conversion sequence for the implicit 2640 // object parameter. 2641 ImplicitConversionSequence ObjectInit 2642 = TryObjectArgumentInitialization(Object, Conversion); 2643 if (ObjectInit.ConversionKind == ImplicitConversionSequence::BadConversion) { 2644 Candidate.Viable = false; 2645 return; 2646 } 2647 2648 // The first conversion is actually a user-defined conversion whose 2649 // first conversion is ObjectInit's standard conversion (which is 2650 // effectively a reference binding). Record it as such. 2651 Candidate.Conversions[0].ConversionKind 2652 = ImplicitConversionSequence::UserDefinedConversion; 2653 Candidate.Conversions[0].UserDefined.Before = ObjectInit.Standard; 2654 Candidate.Conversions[0].UserDefined.ConversionFunction = Conversion; 2655 Candidate.Conversions[0].UserDefined.After 2656 = Candidate.Conversions[0].UserDefined.Before; 2657 Candidate.Conversions[0].UserDefined.After.setAsIdentityConversion(); 2658 2659 // Find the 2660 unsigned NumArgsInProto = Proto->getNumArgs(); 2661 2662 // (C++ 13.3.2p2): A candidate function having fewer than m 2663 // parameters is viable only if it has an ellipsis in its parameter 2664 // list (8.3.5). 2665 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 2666 Candidate.Viable = false; 2667 return; 2668 } 2669 2670 // Function types don't have any default arguments, so just check if 2671 // we have enough arguments. 2672 if (NumArgs < NumArgsInProto) { 2673 // Not enough arguments. 2674 Candidate.Viable = false; 2675 return; 2676 } 2677 2678 // Determine the implicit conversion sequences for each of the 2679 // arguments. 2680 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2681 if (ArgIdx < NumArgsInProto) { 2682 // (C++ 13.3.2p3): for F to be a viable function, there shall 2683 // exist for each argument an implicit conversion sequence 2684 // (13.3.3.1) that converts that argument to the corresponding 2685 // parameter of F. 2686 QualType ParamType = Proto->getArgType(ArgIdx); 2687 Candidate.Conversions[ArgIdx + 1] 2688 = TryCopyInitialization(Args[ArgIdx], ParamType, 2689 /*SuppressUserConversions=*/false, 2690 /*ForceRValue=*/false, 2691 /*InOverloadResolution=*/false); 2692 if (Candidate.Conversions[ArgIdx + 1].ConversionKind 2693 == ImplicitConversionSequence::BadConversion) { 2694 Candidate.Viable = false; 2695 break; 2696 } 2697 } else { 2698 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2699 // argument for which there is no corresponding parameter is 2700 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2701 Candidate.Conversions[ArgIdx + 1].ConversionKind 2702 = ImplicitConversionSequence::EllipsisConversion; 2703 } 2704 } 2705} 2706 2707// FIXME: This will eventually be removed, once we've migrated all of the 2708// operator overloading logic over to the scheme used by binary operators, which 2709// works for template instantiation. 2710void Sema::AddOperatorCandidates(OverloadedOperatorKind Op, Scope *S, 2711 SourceLocation OpLoc, 2712 Expr **Args, unsigned NumArgs, 2713 OverloadCandidateSet& CandidateSet, 2714 SourceRange OpRange) { 2715 FunctionSet Functions; 2716 2717 QualType T1 = Args[0]->getType(); 2718 QualType T2; 2719 if (NumArgs > 1) 2720 T2 = Args[1]->getType(); 2721 2722 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 2723 if (S) 2724 LookupOverloadedOperatorName(Op, S, T1, T2, Functions); 2725 ArgumentDependentLookup(OpName, Args, NumArgs, Functions); 2726 AddFunctionCandidates(Functions, Args, NumArgs, CandidateSet); 2727 AddMemberOperatorCandidates(Op, OpLoc, Args, NumArgs, CandidateSet, OpRange); 2728 AddBuiltinOperatorCandidates(Op, Args, NumArgs, CandidateSet); 2729} 2730 2731/// \brief Add overload candidates for overloaded operators that are 2732/// member functions. 2733/// 2734/// Add the overloaded operator candidates that are member functions 2735/// for the operator Op that was used in an operator expression such 2736/// as "x Op y". , Args/NumArgs provides the operator arguments, and 2737/// CandidateSet will store the added overload candidates. (C++ 2738/// [over.match.oper]). 2739void Sema::AddMemberOperatorCandidates(OverloadedOperatorKind Op, 2740 SourceLocation OpLoc, 2741 Expr **Args, unsigned NumArgs, 2742 OverloadCandidateSet& CandidateSet, 2743 SourceRange OpRange) { 2744 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 2745 2746 // C++ [over.match.oper]p3: 2747 // For a unary operator @ with an operand of a type whose 2748 // cv-unqualified version is T1, and for a binary operator @ with 2749 // a left operand of a type whose cv-unqualified version is T1 and 2750 // a right operand of a type whose cv-unqualified version is T2, 2751 // three sets of candidate functions, designated member 2752 // candidates, non-member candidates and built-in candidates, are 2753 // constructed as follows: 2754 QualType T1 = Args[0]->getType(); 2755 QualType T2; 2756 if (NumArgs > 1) 2757 T2 = Args[1]->getType(); 2758 2759 // -- If T1 is a class type, the set of member candidates is the 2760 // result of the qualified lookup of T1::operator@ 2761 // (13.3.1.1.1); otherwise, the set of member candidates is 2762 // empty. 2763 if (const RecordType *T1Rec = T1->getAs<RecordType>()) { 2764 // Complete the type if it can be completed. Otherwise, we're done. 2765 if (RequireCompleteType(OpLoc, T1, PartialDiagnostic(0))) 2766 return; 2767 2768 LookupResult Operators = LookupQualifiedName(T1Rec->getDecl(), OpName, 2769 LookupOrdinaryName, false); 2770 for (LookupResult::iterator Oper = Operators.begin(), 2771 OperEnd = Operators.end(); 2772 Oper != OperEnd; 2773 ++Oper) 2774 AddMethodCandidate(cast<CXXMethodDecl>(*Oper), Args[0], 2775 Args+1, NumArgs - 1, CandidateSet, 2776 /*SuppressUserConversions=*/false); 2777 } 2778} 2779 2780/// AddBuiltinCandidate - Add a candidate for a built-in 2781/// operator. ResultTy and ParamTys are the result and parameter types 2782/// of the built-in candidate, respectively. Args and NumArgs are the 2783/// arguments being passed to the candidate. IsAssignmentOperator 2784/// should be true when this built-in candidate is an assignment 2785/// operator. NumContextualBoolArguments is the number of arguments 2786/// (at the beginning of the argument list) that will be contextually 2787/// converted to bool. 2788void Sema::AddBuiltinCandidate(QualType ResultTy, QualType *ParamTys, 2789 Expr **Args, unsigned NumArgs, 2790 OverloadCandidateSet& CandidateSet, 2791 bool IsAssignmentOperator, 2792 unsigned NumContextualBoolArguments) { 2793 // Add this candidate 2794 CandidateSet.push_back(OverloadCandidate()); 2795 OverloadCandidate& Candidate = CandidateSet.back(); 2796 Candidate.Function = 0; 2797 Candidate.IsSurrogate = false; 2798 Candidate.IgnoreObjectArgument = false; 2799 Candidate.BuiltinTypes.ResultTy = ResultTy; 2800 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 2801 Candidate.BuiltinTypes.ParamTypes[ArgIdx] = ParamTys[ArgIdx]; 2802 2803 // Determine the implicit conversion sequences for each of the 2804 // arguments. 2805 Candidate.Viable = true; 2806 Candidate.Conversions.resize(NumArgs); 2807 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2808 // C++ [over.match.oper]p4: 2809 // For the built-in assignment operators, conversions of the 2810 // left operand are restricted as follows: 2811 // -- no temporaries are introduced to hold the left operand, and 2812 // -- no user-defined conversions are applied to the left 2813 // operand to achieve a type match with the left-most 2814 // parameter of a built-in candidate. 2815 // 2816 // We block these conversions by turning off user-defined 2817 // conversions, since that is the only way that initialization of 2818 // a reference to a non-class type can occur from something that 2819 // is not of the same type. 2820 if (ArgIdx < NumContextualBoolArguments) { 2821 assert(ParamTys[ArgIdx] == Context.BoolTy && 2822 "Contextual conversion to bool requires bool type"); 2823 Candidate.Conversions[ArgIdx] = TryContextuallyConvertToBool(Args[ArgIdx]); 2824 } else { 2825 Candidate.Conversions[ArgIdx] 2826 = TryCopyInitialization(Args[ArgIdx], ParamTys[ArgIdx], 2827 ArgIdx == 0 && IsAssignmentOperator, 2828 /*ForceRValue=*/false, 2829 /*InOverloadResolution=*/false); 2830 } 2831 if (Candidate.Conversions[ArgIdx].ConversionKind 2832 == ImplicitConversionSequence::BadConversion) { 2833 Candidate.Viable = false; 2834 break; 2835 } 2836 } 2837} 2838 2839/// BuiltinCandidateTypeSet - A set of types that will be used for the 2840/// candidate operator functions for built-in operators (C++ 2841/// [over.built]). The types are separated into pointer types and 2842/// enumeration types. 2843class BuiltinCandidateTypeSet { 2844 /// TypeSet - A set of types. 2845 typedef llvm::SmallPtrSet<QualType, 8> TypeSet; 2846 2847 /// PointerTypes - The set of pointer types that will be used in the 2848 /// built-in candidates. 2849 TypeSet PointerTypes; 2850 2851 /// MemberPointerTypes - The set of member pointer types that will be 2852 /// used in the built-in candidates. 2853 TypeSet MemberPointerTypes; 2854 2855 /// EnumerationTypes - The set of enumeration types that will be 2856 /// used in the built-in candidates. 2857 TypeSet EnumerationTypes; 2858 2859 /// Sema - The semantic analysis instance where we are building the 2860 /// candidate type set. 2861 Sema &SemaRef; 2862 2863 /// Context - The AST context in which we will build the type sets. 2864 ASTContext &Context; 2865 2866 bool AddPointerWithMoreQualifiedTypeVariants(QualType Ty); 2867 bool AddMemberPointerWithMoreQualifiedTypeVariants(QualType Ty); 2868 2869public: 2870 /// iterator - Iterates through the types that are part of the set. 2871 typedef TypeSet::iterator iterator; 2872 2873 BuiltinCandidateTypeSet(Sema &SemaRef) 2874 : SemaRef(SemaRef), Context(SemaRef.Context) { } 2875 2876 void AddTypesConvertedFrom(QualType Ty, bool AllowUserConversions, 2877 bool AllowExplicitConversions); 2878 2879 /// pointer_begin - First pointer type found; 2880 iterator pointer_begin() { return PointerTypes.begin(); } 2881 2882 /// pointer_end - Past the last pointer type found; 2883 iterator pointer_end() { return PointerTypes.end(); } 2884 2885 /// member_pointer_begin - First member pointer type found; 2886 iterator member_pointer_begin() { return MemberPointerTypes.begin(); } 2887 2888 /// member_pointer_end - Past the last member pointer type found; 2889 iterator member_pointer_end() { return MemberPointerTypes.end(); } 2890 2891 /// enumeration_begin - First enumeration type found; 2892 iterator enumeration_begin() { return EnumerationTypes.begin(); } 2893 2894 /// enumeration_end - Past the last enumeration type found; 2895 iterator enumeration_end() { return EnumerationTypes.end(); } 2896}; 2897 2898/// AddPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty to 2899/// the set of pointer types along with any more-qualified variants of 2900/// that type. For example, if @p Ty is "int const *", this routine 2901/// will add "int const *", "int const volatile *", "int const 2902/// restrict *", and "int const volatile restrict *" to the set of 2903/// pointer types. Returns true if the add of @p Ty itself succeeded, 2904/// false otherwise. 2905/// 2906/// FIXME: what to do about extended qualifiers? 2907bool 2908BuiltinCandidateTypeSet::AddPointerWithMoreQualifiedTypeVariants(QualType Ty) { 2909 2910 // Insert this type. 2911 if (!PointerTypes.insert(Ty)) 2912 return false; 2913 2914 const PointerType *PointerTy = Ty->getAs<PointerType>(); 2915 assert(PointerTy && "type was not a pointer type!"); 2916 2917 QualType PointeeTy = PointerTy->getPointeeType(); 2918 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 2919 2920 // Iterate through all strict supersets of BaseCVR. 2921 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 2922 if ((CVR | BaseCVR) != CVR) continue; 2923 2924 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 2925 PointerTypes.insert(Context.getPointerType(QPointeeTy)); 2926 } 2927 2928 return true; 2929} 2930 2931/// AddMemberPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty 2932/// to the set of pointer types along with any more-qualified variants of 2933/// that type. For example, if @p Ty is "int const *", this routine 2934/// will add "int const *", "int const volatile *", "int const 2935/// restrict *", and "int const volatile restrict *" to the set of 2936/// pointer types. Returns true if the add of @p Ty itself succeeded, 2937/// false otherwise. 2938/// 2939/// FIXME: what to do about extended qualifiers? 2940bool 2941BuiltinCandidateTypeSet::AddMemberPointerWithMoreQualifiedTypeVariants( 2942 QualType Ty) { 2943 // Insert this type. 2944 if (!MemberPointerTypes.insert(Ty)) 2945 return false; 2946 2947 const MemberPointerType *PointerTy = Ty->getAs<MemberPointerType>(); 2948 assert(PointerTy && "type was not a member pointer type!"); 2949 2950 QualType PointeeTy = PointerTy->getPointeeType(); 2951 const Type *ClassTy = PointerTy->getClass(); 2952 2953 // Iterate through all strict supersets of the pointee type's CVR 2954 // qualifiers. 2955 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 2956 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 2957 if ((CVR | BaseCVR) != CVR) continue; 2958 2959 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 2960 MemberPointerTypes.insert(Context.getMemberPointerType(QPointeeTy, ClassTy)); 2961 } 2962 2963 return true; 2964} 2965 2966/// AddTypesConvertedFrom - Add each of the types to which the type @p 2967/// Ty can be implicit converted to the given set of @p Types. We're 2968/// primarily interested in pointer types and enumeration types. We also 2969/// take member pointer types, for the conditional operator. 2970/// AllowUserConversions is true if we should look at the conversion 2971/// functions of a class type, and AllowExplicitConversions if we 2972/// should also include the explicit conversion functions of a class 2973/// type. 2974void 2975BuiltinCandidateTypeSet::AddTypesConvertedFrom(QualType Ty, 2976 bool AllowUserConversions, 2977 bool AllowExplicitConversions) { 2978 // Only deal with canonical types. 2979 Ty = Context.getCanonicalType(Ty); 2980 2981 // Look through reference types; they aren't part of the type of an 2982 // expression for the purposes of conversions. 2983 if (const ReferenceType *RefTy = Ty->getAs<ReferenceType>()) 2984 Ty = RefTy->getPointeeType(); 2985 2986 // We don't care about qualifiers on the type. 2987 Ty = Ty.getUnqualifiedType(); 2988 2989 if (const PointerType *PointerTy = Ty->getAs<PointerType>()) { 2990 QualType PointeeTy = PointerTy->getPointeeType(); 2991 2992 // Insert our type, and its more-qualified variants, into the set 2993 // of types. 2994 if (!AddPointerWithMoreQualifiedTypeVariants(Ty)) 2995 return; 2996 2997 // Add 'cv void*' to our set of types. 2998 if (!Ty->isVoidType()) { 2999 QualType QualVoid 3000 = Context.getCVRQualifiedType(Context.VoidTy, 3001 PointeeTy.getCVRQualifiers()); 3002 AddPointerWithMoreQualifiedTypeVariants(Context.getPointerType(QualVoid)); 3003 } 3004 3005 // If this is a pointer to a class type, add pointers to its bases 3006 // (with the same level of cv-qualification as the original 3007 // derived class, of course). 3008 if (const RecordType *PointeeRec = PointeeTy->getAs<RecordType>()) { 3009 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(PointeeRec->getDecl()); 3010 for (CXXRecordDecl::base_class_iterator Base = ClassDecl->bases_begin(); 3011 Base != ClassDecl->bases_end(); ++Base) { 3012 QualType BaseTy = Context.getCanonicalType(Base->getType()); 3013 BaseTy = Context.getCVRQualifiedType(BaseTy.getUnqualifiedType(), 3014 PointeeTy.getCVRQualifiers()); 3015 3016 // Add the pointer type, recursively, so that we get all of 3017 // the indirect base classes, too. 3018 AddTypesConvertedFrom(Context.getPointerType(BaseTy), false, false); 3019 } 3020 } 3021 } else if (Ty->isMemberPointerType()) { 3022 // Member pointers are far easier, since the pointee can't be converted. 3023 if (!AddMemberPointerWithMoreQualifiedTypeVariants(Ty)) 3024 return; 3025 } else if (Ty->isEnumeralType()) { 3026 EnumerationTypes.insert(Ty); 3027 } else if (AllowUserConversions) { 3028 if (const RecordType *TyRec = Ty->getAs<RecordType>()) { 3029 if (SemaRef.RequireCompleteType(SourceLocation(), Ty, 0)) { 3030 // No conversion functions in incomplete types. 3031 return; 3032 } 3033 3034 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 3035 // FIXME: Visit conversion functions in the base classes, too. 3036 OverloadedFunctionDecl *Conversions 3037 = ClassDecl->getConversionFunctions(); 3038 for (OverloadedFunctionDecl::function_iterator Func 3039 = Conversions->function_begin(); 3040 Func != Conversions->function_end(); ++Func) { 3041 CXXConversionDecl *Conv; 3042 FunctionTemplateDecl *ConvTemplate; 3043 GetFunctionAndTemplate(*Func, Conv, ConvTemplate); 3044 3045 // Skip conversion function templates; they don't tell us anything 3046 // about which builtin types we can convert to. 3047 if (ConvTemplate) 3048 continue; 3049 3050 if (AllowExplicitConversions || !Conv->isExplicit()) 3051 AddTypesConvertedFrom(Conv->getConversionType(), false, false); 3052 } 3053 } 3054 } 3055} 3056 3057/// \brief Helper function for AddBuiltinOperatorCandidates() that adds 3058/// the volatile- and non-volatile-qualified assignment operators for the 3059/// given type to the candidate set. 3060static void AddBuiltinAssignmentOperatorCandidates(Sema &S, 3061 QualType T, 3062 Expr **Args, 3063 unsigned NumArgs, 3064 OverloadCandidateSet &CandidateSet) { 3065 QualType ParamTypes[2]; 3066 3067 // T& operator=(T&, T) 3068 ParamTypes[0] = S.Context.getLValueReferenceType(T); 3069 ParamTypes[1] = T; 3070 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3071 /*IsAssignmentOperator=*/true); 3072 3073 if (!S.Context.getCanonicalType(T).isVolatileQualified()) { 3074 // volatile T& operator=(volatile T&, T) 3075 ParamTypes[0] 3076 = S.Context.getLValueReferenceType(S.Context.getVolatileType(T)); 3077 ParamTypes[1] = T; 3078 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3079 /*IsAssignmentOperator=*/true); 3080 } 3081} 3082 3083/// AddBuiltinOperatorCandidates - Add the appropriate built-in 3084/// operator overloads to the candidate set (C++ [over.built]), based 3085/// on the operator @p Op and the arguments given. For example, if the 3086/// operator is a binary '+', this routine might add "int 3087/// operator+(int, int)" to cover integer addition. 3088void 3089Sema::AddBuiltinOperatorCandidates(OverloadedOperatorKind Op, 3090 Expr **Args, unsigned NumArgs, 3091 OverloadCandidateSet& CandidateSet) { 3092 // The set of "promoted arithmetic types", which are the arithmetic 3093 // types are that preserved by promotion (C++ [over.built]p2). Note 3094 // that the first few of these types are the promoted integral 3095 // types; these types need to be first. 3096 // FIXME: What about complex? 3097 const unsigned FirstIntegralType = 0; 3098 const unsigned LastIntegralType = 13; 3099 const unsigned FirstPromotedIntegralType = 7, 3100 LastPromotedIntegralType = 13; 3101 const unsigned FirstPromotedArithmeticType = 7, 3102 LastPromotedArithmeticType = 16; 3103 const unsigned NumArithmeticTypes = 16; 3104 QualType ArithmeticTypes[NumArithmeticTypes] = { 3105 Context.BoolTy, Context.CharTy, Context.WCharTy, 3106// FIXME: Context.Char16Ty, Context.Char32Ty, 3107 Context.SignedCharTy, Context.ShortTy, 3108 Context.UnsignedCharTy, Context.UnsignedShortTy, 3109 Context.IntTy, Context.LongTy, Context.LongLongTy, 3110 Context.UnsignedIntTy, Context.UnsignedLongTy, Context.UnsignedLongLongTy, 3111 Context.FloatTy, Context.DoubleTy, Context.LongDoubleTy 3112 }; 3113 3114 // Find all of the types that the arguments can convert to, but only 3115 // if the operator we're looking at has built-in operator candidates 3116 // that make use of these types. 3117 BuiltinCandidateTypeSet CandidateTypes(*this); 3118 if (Op == OO_Less || Op == OO_Greater || Op == OO_LessEqual || 3119 Op == OO_GreaterEqual || Op == OO_EqualEqual || Op == OO_ExclaimEqual || 3120 Op == OO_Plus || (Op == OO_Minus && NumArgs == 2) || Op == OO_Equal || 3121 Op == OO_PlusEqual || Op == OO_MinusEqual || Op == OO_Subscript || 3122 Op == OO_ArrowStar || Op == OO_PlusPlus || Op == OO_MinusMinus || 3123 (Op == OO_Star && NumArgs == 1) || Op == OO_Conditional) { 3124 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 3125 CandidateTypes.AddTypesConvertedFrom(Args[ArgIdx]->getType(), 3126 true, 3127 (Op == OO_Exclaim || 3128 Op == OO_AmpAmp || 3129 Op == OO_PipePipe)); 3130 } 3131 3132 bool isComparison = false; 3133 switch (Op) { 3134 case OO_None: 3135 case NUM_OVERLOADED_OPERATORS: 3136 assert(false && "Expected an overloaded operator"); 3137 break; 3138 3139 case OO_Star: // '*' is either unary or binary 3140 if (NumArgs == 1) 3141 goto UnaryStar; 3142 else 3143 goto BinaryStar; 3144 break; 3145 3146 case OO_Plus: // '+' is either unary or binary 3147 if (NumArgs == 1) 3148 goto UnaryPlus; 3149 else 3150 goto BinaryPlus; 3151 break; 3152 3153 case OO_Minus: // '-' is either unary or binary 3154 if (NumArgs == 1) 3155 goto UnaryMinus; 3156 else 3157 goto BinaryMinus; 3158 break; 3159 3160 case OO_Amp: // '&' is either unary or binary 3161 if (NumArgs == 1) 3162 goto UnaryAmp; 3163 else 3164 goto BinaryAmp; 3165 3166 case OO_PlusPlus: 3167 case OO_MinusMinus: 3168 // C++ [over.built]p3: 3169 // 3170 // For every pair (T, VQ), where T is an arithmetic type, and VQ 3171 // is either volatile or empty, there exist candidate operator 3172 // functions of the form 3173 // 3174 // VQ T& operator++(VQ T&); 3175 // T operator++(VQ T&, int); 3176 // 3177 // C++ [over.built]p4: 3178 // 3179 // For every pair (T, VQ), where T is an arithmetic type other 3180 // than bool, and VQ is either volatile or empty, there exist 3181 // candidate operator functions of the form 3182 // 3183 // VQ T& operator--(VQ T&); 3184 // T operator--(VQ T&, int); 3185 for (unsigned Arith = (Op == OO_PlusPlus? 0 : 1); 3186 Arith < NumArithmeticTypes; ++Arith) { 3187 QualType ArithTy = ArithmeticTypes[Arith]; 3188 QualType ParamTypes[2] 3189 = { Context.getLValueReferenceType(ArithTy), Context.IntTy }; 3190 3191 // Non-volatile version. 3192 if (NumArgs == 1) 3193 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3194 else 3195 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 3196 3197 // Volatile version 3198 ParamTypes[0] 3199 = Context.getLValueReferenceType(Context.getVolatileType(ArithTy)); 3200 if (NumArgs == 1) 3201 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3202 else 3203 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 3204 } 3205 3206 // C++ [over.built]p5: 3207 // 3208 // For every pair (T, VQ), where T is a cv-qualified or 3209 // cv-unqualified object type, and VQ is either volatile or 3210 // empty, there exist candidate operator functions of the form 3211 // 3212 // T*VQ& operator++(T*VQ&); 3213 // T*VQ& operator--(T*VQ&); 3214 // T* operator++(T*VQ&, int); 3215 // T* operator--(T*VQ&, int); 3216 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3217 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3218 // Skip pointer types that aren't pointers to object types. 3219 if (!(*Ptr)->getAs<PointerType>()->getPointeeType()->isObjectType()) 3220 continue; 3221 3222 QualType ParamTypes[2] = { 3223 Context.getLValueReferenceType(*Ptr), Context.IntTy 3224 }; 3225 3226 // Without volatile 3227 if (NumArgs == 1) 3228 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3229 else 3230 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3231 3232 if (!Context.getCanonicalType(*Ptr).isVolatileQualified()) { 3233 // With volatile 3234 ParamTypes[0] 3235 = Context.getLValueReferenceType(Context.getVolatileType(*Ptr)); 3236 if (NumArgs == 1) 3237 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3238 else 3239 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3240 } 3241 } 3242 break; 3243 3244 UnaryStar: 3245 // C++ [over.built]p6: 3246 // For every cv-qualified or cv-unqualified object type T, there 3247 // exist candidate operator functions of the form 3248 // 3249 // T& operator*(T*); 3250 // 3251 // C++ [over.built]p7: 3252 // For every function type T, there exist candidate operator 3253 // functions of the form 3254 // T& operator*(T*); 3255 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3256 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3257 QualType ParamTy = *Ptr; 3258 QualType PointeeTy = ParamTy->getAs<PointerType>()->getPointeeType(); 3259 AddBuiltinCandidate(Context.getLValueReferenceType(PointeeTy), 3260 &ParamTy, Args, 1, CandidateSet); 3261 } 3262 break; 3263 3264 UnaryPlus: 3265 // C++ [over.built]p8: 3266 // For every type T, there exist candidate operator functions of 3267 // the form 3268 // 3269 // T* operator+(T*); 3270 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3271 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3272 QualType ParamTy = *Ptr; 3273 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet); 3274 } 3275 3276 // Fall through 3277 3278 UnaryMinus: 3279 // C++ [over.built]p9: 3280 // For every promoted arithmetic type T, there exist candidate 3281 // operator functions of the form 3282 // 3283 // T operator+(T); 3284 // T operator-(T); 3285 for (unsigned Arith = FirstPromotedArithmeticType; 3286 Arith < LastPromotedArithmeticType; ++Arith) { 3287 QualType ArithTy = ArithmeticTypes[Arith]; 3288 AddBuiltinCandidate(ArithTy, &ArithTy, Args, 1, CandidateSet); 3289 } 3290 break; 3291 3292 case OO_Tilde: 3293 // C++ [over.built]p10: 3294 // For every promoted integral type T, there exist candidate 3295 // operator functions of the form 3296 // 3297 // T operator~(T); 3298 for (unsigned Int = FirstPromotedIntegralType; 3299 Int < LastPromotedIntegralType; ++Int) { 3300 QualType IntTy = ArithmeticTypes[Int]; 3301 AddBuiltinCandidate(IntTy, &IntTy, Args, 1, CandidateSet); 3302 } 3303 break; 3304 3305 case OO_New: 3306 case OO_Delete: 3307 case OO_Array_New: 3308 case OO_Array_Delete: 3309 case OO_Call: 3310 assert(false && "Special operators don't use AddBuiltinOperatorCandidates"); 3311 break; 3312 3313 case OO_Comma: 3314 UnaryAmp: 3315 case OO_Arrow: 3316 // C++ [over.match.oper]p3: 3317 // -- For the operator ',', the unary operator '&', or the 3318 // operator '->', the built-in candidates set is empty. 3319 break; 3320 3321 case OO_EqualEqual: 3322 case OO_ExclaimEqual: 3323 // C++ [over.match.oper]p16: 3324 // For every pointer to member type T, there exist candidate operator 3325 // functions of the form 3326 // 3327 // bool operator==(T,T); 3328 // bool operator!=(T,T); 3329 for (BuiltinCandidateTypeSet::iterator 3330 MemPtr = CandidateTypes.member_pointer_begin(), 3331 MemPtrEnd = CandidateTypes.member_pointer_end(); 3332 MemPtr != MemPtrEnd; 3333 ++MemPtr) { 3334 QualType ParamTypes[2] = { *MemPtr, *MemPtr }; 3335 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 3336 } 3337 3338 // Fall through 3339 3340 case OO_Less: 3341 case OO_Greater: 3342 case OO_LessEqual: 3343 case OO_GreaterEqual: 3344 // C++ [over.built]p15: 3345 // 3346 // For every pointer or enumeration type T, there exist 3347 // candidate operator functions of the form 3348 // 3349 // bool operator<(T, T); 3350 // bool operator>(T, T); 3351 // bool operator<=(T, T); 3352 // bool operator>=(T, T); 3353 // bool operator==(T, T); 3354 // bool operator!=(T, T); 3355 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3356 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3357 QualType ParamTypes[2] = { *Ptr, *Ptr }; 3358 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 3359 } 3360 for (BuiltinCandidateTypeSet::iterator Enum 3361 = CandidateTypes.enumeration_begin(); 3362 Enum != CandidateTypes.enumeration_end(); ++Enum) { 3363 QualType ParamTypes[2] = { *Enum, *Enum }; 3364 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 3365 } 3366 3367 // Fall through. 3368 isComparison = true; 3369 3370 BinaryPlus: 3371 BinaryMinus: 3372 if (!isComparison) { 3373 // We didn't fall through, so we must have OO_Plus or OO_Minus. 3374 3375 // C++ [over.built]p13: 3376 // 3377 // For every cv-qualified or cv-unqualified object type T 3378 // there exist candidate operator functions of the form 3379 // 3380 // T* operator+(T*, ptrdiff_t); 3381 // T& operator[](T*, ptrdiff_t); [BELOW] 3382 // T* operator-(T*, ptrdiff_t); 3383 // T* operator+(ptrdiff_t, T*); 3384 // T& operator[](ptrdiff_t, T*); [BELOW] 3385 // 3386 // C++ [over.built]p14: 3387 // 3388 // For every T, where T is a pointer to object type, there 3389 // exist candidate operator functions of the form 3390 // 3391 // ptrdiff_t operator-(T, T); 3392 for (BuiltinCandidateTypeSet::iterator Ptr 3393 = CandidateTypes.pointer_begin(); 3394 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3395 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 3396 3397 // operator+(T*, ptrdiff_t) or operator-(T*, ptrdiff_t) 3398 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3399 3400 if (Op == OO_Plus) { 3401 // T* operator+(ptrdiff_t, T*); 3402 ParamTypes[0] = ParamTypes[1]; 3403 ParamTypes[1] = *Ptr; 3404 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3405 } else { 3406 // ptrdiff_t operator-(T, T); 3407 ParamTypes[1] = *Ptr; 3408 AddBuiltinCandidate(Context.getPointerDiffType(), ParamTypes, 3409 Args, 2, CandidateSet); 3410 } 3411 } 3412 } 3413 // Fall through 3414 3415 case OO_Slash: 3416 BinaryStar: 3417 Conditional: 3418 // C++ [over.built]p12: 3419 // 3420 // For every pair of promoted arithmetic types L and R, there 3421 // exist candidate operator functions of the form 3422 // 3423 // LR operator*(L, R); 3424 // LR operator/(L, R); 3425 // LR operator+(L, R); 3426 // LR operator-(L, R); 3427 // bool operator<(L, R); 3428 // bool operator>(L, R); 3429 // bool operator<=(L, R); 3430 // bool operator>=(L, R); 3431 // bool operator==(L, R); 3432 // bool operator!=(L, R); 3433 // 3434 // where LR is the result of the usual arithmetic conversions 3435 // between types L and R. 3436 // 3437 // C++ [over.built]p24: 3438 // 3439 // For every pair of promoted arithmetic types L and R, there exist 3440 // candidate operator functions of the form 3441 // 3442 // LR operator?(bool, L, R); 3443 // 3444 // where LR is the result of the usual arithmetic conversions 3445 // between types L and R. 3446 // Our candidates ignore the first parameter. 3447 for (unsigned Left = FirstPromotedArithmeticType; 3448 Left < LastPromotedArithmeticType; ++Left) { 3449 for (unsigned Right = FirstPromotedArithmeticType; 3450 Right < LastPromotedArithmeticType; ++Right) { 3451 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 3452 QualType Result 3453 = isComparison 3454 ? Context.BoolTy 3455 : Context.UsualArithmeticConversionsType(LandR[0], LandR[1]); 3456 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 3457 } 3458 } 3459 break; 3460 3461 case OO_Percent: 3462 BinaryAmp: 3463 case OO_Caret: 3464 case OO_Pipe: 3465 case OO_LessLess: 3466 case OO_GreaterGreater: 3467 // C++ [over.built]p17: 3468 // 3469 // For every pair of promoted integral types L and R, there 3470 // exist candidate operator functions of the form 3471 // 3472 // LR operator%(L, R); 3473 // LR operator&(L, R); 3474 // LR operator^(L, R); 3475 // LR operator|(L, R); 3476 // L operator<<(L, R); 3477 // L operator>>(L, R); 3478 // 3479 // where LR is the result of the usual arithmetic conversions 3480 // between types L and R. 3481 for (unsigned Left = FirstPromotedIntegralType; 3482 Left < LastPromotedIntegralType; ++Left) { 3483 for (unsigned Right = FirstPromotedIntegralType; 3484 Right < LastPromotedIntegralType; ++Right) { 3485 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 3486 QualType Result = (Op == OO_LessLess || Op == OO_GreaterGreater) 3487 ? LandR[0] 3488 : Context.UsualArithmeticConversionsType(LandR[0], LandR[1]); 3489 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 3490 } 3491 } 3492 break; 3493 3494 case OO_Equal: 3495 // C++ [over.built]p20: 3496 // 3497 // For every pair (T, VQ), where T is an enumeration or 3498 // pointer to member type and VQ is either volatile or 3499 // empty, there exist candidate operator functions of the form 3500 // 3501 // VQ T& operator=(VQ T&, T); 3502 for (BuiltinCandidateTypeSet::iterator 3503 Enum = CandidateTypes.enumeration_begin(), 3504 EnumEnd = CandidateTypes.enumeration_end(); 3505 Enum != EnumEnd; ++Enum) 3506 AddBuiltinAssignmentOperatorCandidates(*this, *Enum, Args, 2, 3507 CandidateSet); 3508 for (BuiltinCandidateTypeSet::iterator 3509 MemPtr = CandidateTypes.member_pointer_begin(), 3510 MemPtrEnd = CandidateTypes.member_pointer_end(); 3511 MemPtr != MemPtrEnd; ++MemPtr) 3512 AddBuiltinAssignmentOperatorCandidates(*this, *MemPtr, Args, 2, 3513 CandidateSet); 3514 // Fall through. 3515 3516 case OO_PlusEqual: 3517 case OO_MinusEqual: 3518 // C++ [over.built]p19: 3519 // 3520 // For every pair (T, VQ), where T is any type and VQ is either 3521 // volatile or empty, there exist candidate operator functions 3522 // of the form 3523 // 3524 // T*VQ& operator=(T*VQ&, T*); 3525 // 3526 // C++ [over.built]p21: 3527 // 3528 // For every pair (T, VQ), where T is a cv-qualified or 3529 // cv-unqualified object type and VQ is either volatile or 3530 // empty, there exist candidate operator functions of the form 3531 // 3532 // T*VQ& operator+=(T*VQ&, ptrdiff_t); 3533 // T*VQ& operator-=(T*VQ&, ptrdiff_t); 3534 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3535 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3536 QualType ParamTypes[2]; 3537 ParamTypes[1] = (Op == OO_Equal)? *Ptr : Context.getPointerDiffType(); 3538 3539 // non-volatile version 3540 ParamTypes[0] = Context.getLValueReferenceType(*Ptr); 3541 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3542 /*IsAssigmentOperator=*/Op == OO_Equal); 3543 3544 if (!Context.getCanonicalType(*Ptr).isVolatileQualified()) { 3545 // volatile version 3546 ParamTypes[0] 3547 = Context.getLValueReferenceType(Context.getVolatileType(*Ptr)); 3548 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3549 /*IsAssigmentOperator=*/Op == OO_Equal); 3550 } 3551 } 3552 // Fall through. 3553 3554 case OO_StarEqual: 3555 case OO_SlashEqual: 3556 // C++ [over.built]p18: 3557 // 3558 // For every triple (L, VQ, R), where L is an arithmetic type, 3559 // VQ is either volatile or empty, and R is a promoted 3560 // arithmetic type, there exist candidate operator functions of 3561 // the form 3562 // 3563 // VQ L& operator=(VQ L&, R); 3564 // VQ L& operator*=(VQ L&, R); 3565 // VQ L& operator/=(VQ L&, R); 3566 // VQ L& operator+=(VQ L&, R); 3567 // VQ L& operator-=(VQ L&, R); 3568 for (unsigned Left = 0; Left < NumArithmeticTypes; ++Left) { 3569 for (unsigned Right = FirstPromotedArithmeticType; 3570 Right < LastPromotedArithmeticType; ++Right) { 3571 QualType ParamTypes[2]; 3572 ParamTypes[1] = ArithmeticTypes[Right]; 3573 3574 // Add this built-in operator as a candidate (VQ is empty). 3575 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 3576 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3577 /*IsAssigmentOperator=*/Op == OO_Equal); 3578 3579 // Add this built-in operator as a candidate (VQ is 'volatile'). 3580 ParamTypes[0] = Context.getVolatileType(ArithmeticTypes[Left]); 3581 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 3582 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3583 /*IsAssigmentOperator=*/Op == OO_Equal); 3584 } 3585 } 3586 break; 3587 3588 case OO_PercentEqual: 3589 case OO_LessLessEqual: 3590 case OO_GreaterGreaterEqual: 3591 case OO_AmpEqual: 3592 case OO_CaretEqual: 3593 case OO_PipeEqual: 3594 // C++ [over.built]p22: 3595 // 3596 // For every triple (L, VQ, R), where L is an integral type, VQ 3597 // is either volatile or empty, and R is a promoted integral 3598 // type, there exist candidate operator functions of the form 3599 // 3600 // VQ L& operator%=(VQ L&, R); 3601 // VQ L& operator<<=(VQ L&, R); 3602 // VQ L& operator>>=(VQ L&, R); 3603 // VQ L& operator&=(VQ L&, R); 3604 // VQ L& operator^=(VQ L&, R); 3605 // VQ L& operator|=(VQ L&, R); 3606 for (unsigned Left = FirstIntegralType; Left < LastIntegralType; ++Left) { 3607 for (unsigned Right = FirstPromotedIntegralType; 3608 Right < LastPromotedIntegralType; ++Right) { 3609 QualType ParamTypes[2]; 3610 ParamTypes[1] = ArithmeticTypes[Right]; 3611 3612 // Add this built-in operator as a candidate (VQ is empty). 3613 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 3614 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 3615 3616 // Add this built-in operator as a candidate (VQ is 'volatile'). 3617 ParamTypes[0] = ArithmeticTypes[Left]; 3618 ParamTypes[0] = Context.getVolatileType(ParamTypes[0]); 3619 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 3620 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 3621 } 3622 } 3623 break; 3624 3625 case OO_Exclaim: { 3626 // C++ [over.operator]p23: 3627 // 3628 // There also exist candidate operator functions of the form 3629 // 3630 // bool operator!(bool); 3631 // bool operator&&(bool, bool); [BELOW] 3632 // bool operator||(bool, bool); [BELOW] 3633 QualType ParamTy = Context.BoolTy; 3634 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet, 3635 /*IsAssignmentOperator=*/false, 3636 /*NumContextualBoolArguments=*/1); 3637 break; 3638 } 3639 3640 case OO_AmpAmp: 3641 case OO_PipePipe: { 3642 // C++ [over.operator]p23: 3643 // 3644 // There also exist candidate operator functions of the form 3645 // 3646 // bool operator!(bool); [ABOVE] 3647 // bool operator&&(bool, bool); 3648 // bool operator||(bool, bool); 3649 QualType ParamTypes[2] = { Context.BoolTy, Context.BoolTy }; 3650 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet, 3651 /*IsAssignmentOperator=*/false, 3652 /*NumContextualBoolArguments=*/2); 3653 break; 3654 } 3655 3656 case OO_Subscript: 3657 // C++ [over.built]p13: 3658 // 3659 // For every cv-qualified or cv-unqualified object type T there 3660 // exist candidate operator functions of the form 3661 // 3662 // T* operator+(T*, ptrdiff_t); [ABOVE] 3663 // T& operator[](T*, ptrdiff_t); 3664 // T* operator-(T*, ptrdiff_t); [ABOVE] 3665 // T* operator+(ptrdiff_t, T*); [ABOVE] 3666 // T& operator[](ptrdiff_t, T*); 3667 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3668 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3669 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 3670 QualType PointeeType = (*Ptr)->getAs<PointerType>()->getPointeeType(); 3671 QualType ResultTy = Context.getLValueReferenceType(PointeeType); 3672 3673 // T& operator[](T*, ptrdiff_t) 3674 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 3675 3676 // T& operator[](ptrdiff_t, T*); 3677 ParamTypes[0] = ParamTypes[1]; 3678 ParamTypes[1] = *Ptr; 3679 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 3680 } 3681 break; 3682 3683 case OO_ArrowStar: 3684 // FIXME: No support for pointer-to-members yet. 3685 break; 3686 3687 case OO_Conditional: 3688 // Note that we don't consider the first argument, since it has been 3689 // contextually converted to bool long ago. The candidates below are 3690 // therefore added as binary. 3691 // 3692 // C++ [over.built]p24: 3693 // For every type T, where T is a pointer or pointer-to-member type, 3694 // there exist candidate operator functions of the form 3695 // 3696 // T operator?(bool, T, T); 3697 // 3698 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(), 3699 E = CandidateTypes.pointer_end(); Ptr != E; ++Ptr) { 3700 QualType ParamTypes[2] = { *Ptr, *Ptr }; 3701 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3702 } 3703 for (BuiltinCandidateTypeSet::iterator Ptr = 3704 CandidateTypes.member_pointer_begin(), 3705 E = CandidateTypes.member_pointer_end(); Ptr != E; ++Ptr) { 3706 QualType ParamTypes[2] = { *Ptr, *Ptr }; 3707 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3708 } 3709 goto Conditional; 3710 } 3711} 3712 3713/// \brief Add function candidates found via argument-dependent lookup 3714/// to the set of overloading candidates. 3715/// 3716/// This routine performs argument-dependent name lookup based on the 3717/// given function name (which may also be an operator name) and adds 3718/// all of the overload candidates found by ADL to the overload 3719/// candidate set (C++ [basic.lookup.argdep]). 3720void 3721Sema::AddArgumentDependentLookupCandidates(DeclarationName Name, 3722 Expr **Args, unsigned NumArgs, 3723 bool HasExplicitTemplateArgs, 3724 const TemplateArgument *ExplicitTemplateArgs, 3725 unsigned NumExplicitTemplateArgs, 3726 OverloadCandidateSet& CandidateSet, 3727 bool PartialOverloading) { 3728 FunctionSet Functions; 3729 3730 // FIXME: Should we be trafficking in canonical function decls throughout? 3731 3732 // Record all of the function candidates that we've already 3733 // added to the overload set, so that we don't add those same 3734 // candidates a second time. 3735 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 3736 CandEnd = CandidateSet.end(); 3737 Cand != CandEnd; ++Cand) 3738 if (Cand->Function) { 3739 Functions.insert(Cand->Function); 3740 if (FunctionTemplateDecl *FunTmpl = Cand->Function->getPrimaryTemplate()) 3741 Functions.insert(FunTmpl); 3742 } 3743 3744 // FIXME: Pass in the explicit template arguments? 3745 ArgumentDependentLookup(Name, Args, NumArgs, Functions); 3746 3747 // Erase all of the candidates we already knew about. 3748 // FIXME: This is suboptimal. Is there a better way? 3749 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 3750 CandEnd = CandidateSet.end(); 3751 Cand != CandEnd; ++Cand) 3752 if (Cand->Function) { 3753 Functions.erase(Cand->Function); 3754 if (FunctionTemplateDecl *FunTmpl = Cand->Function->getPrimaryTemplate()) 3755 Functions.erase(FunTmpl); 3756 } 3757 3758 // For each of the ADL candidates we found, add it to the overload 3759 // set. 3760 for (FunctionSet::iterator Func = Functions.begin(), 3761 FuncEnd = Functions.end(); 3762 Func != FuncEnd; ++Func) { 3763 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*Func)) { 3764 if (HasExplicitTemplateArgs) 3765 continue; 3766 3767 AddOverloadCandidate(FD, Args, NumArgs, CandidateSet, 3768 false, false, PartialOverloading); 3769 } else 3770 AddTemplateOverloadCandidate(cast<FunctionTemplateDecl>(*Func), 3771 HasExplicitTemplateArgs, 3772 ExplicitTemplateArgs, 3773 NumExplicitTemplateArgs, 3774 Args, NumArgs, CandidateSet); 3775 } 3776} 3777 3778/// isBetterOverloadCandidate - Determines whether the first overload 3779/// candidate is a better candidate than the second (C++ 13.3.3p1). 3780bool 3781Sema::isBetterOverloadCandidate(const OverloadCandidate& Cand1, 3782 const OverloadCandidate& Cand2) { 3783 // Define viable functions to be better candidates than non-viable 3784 // functions. 3785 if (!Cand2.Viable) 3786 return Cand1.Viable; 3787 else if (!Cand1.Viable) 3788 return false; 3789 3790 // C++ [over.match.best]p1: 3791 // 3792 // -- if F is a static member function, ICS1(F) is defined such 3793 // that ICS1(F) is neither better nor worse than ICS1(G) for 3794 // any function G, and, symmetrically, ICS1(G) is neither 3795 // better nor worse than ICS1(F). 3796 unsigned StartArg = 0; 3797 if (Cand1.IgnoreObjectArgument || Cand2.IgnoreObjectArgument) 3798 StartArg = 1; 3799 3800 // C++ [over.match.best]p1: 3801 // A viable function F1 is defined to be a better function than another 3802 // viable function F2 if for all arguments i, ICSi(F1) is not a worse 3803 // conversion sequence than ICSi(F2), and then... 3804 unsigned NumArgs = Cand1.Conversions.size(); 3805 assert(Cand2.Conversions.size() == NumArgs && "Overload candidate mismatch"); 3806 bool HasBetterConversion = false; 3807 for (unsigned ArgIdx = StartArg; ArgIdx < NumArgs; ++ArgIdx) { 3808 switch (CompareImplicitConversionSequences(Cand1.Conversions[ArgIdx], 3809 Cand2.Conversions[ArgIdx])) { 3810 case ImplicitConversionSequence::Better: 3811 // Cand1 has a better conversion sequence. 3812 HasBetterConversion = true; 3813 break; 3814 3815 case ImplicitConversionSequence::Worse: 3816 // Cand1 can't be better than Cand2. 3817 return false; 3818 3819 case ImplicitConversionSequence::Indistinguishable: 3820 // Do nothing. 3821 break; 3822 } 3823 } 3824 3825 // -- for some argument j, ICSj(F1) is a better conversion sequence than 3826 // ICSj(F2), or, if not that, 3827 if (HasBetterConversion) 3828 return true; 3829 3830 // - F1 is a non-template function and F2 is a function template 3831 // specialization, or, if not that, 3832 if (Cand1.Function && !Cand1.Function->getPrimaryTemplate() && 3833 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 3834 return true; 3835 3836 // -- F1 and F2 are function template specializations, and the function 3837 // template for F1 is more specialized than the template for F2 3838 // according to the partial ordering rules described in 14.5.5.2, or, 3839 // if not that, 3840 if (Cand1.Function && Cand1.Function->getPrimaryTemplate() && 3841 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 3842 if (FunctionTemplateDecl *BetterTemplate 3843 = getMoreSpecializedTemplate(Cand1.Function->getPrimaryTemplate(), 3844 Cand2.Function->getPrimaryTemplate(), 3845 isa<CXXConversionDecl>(Cand1.Function)? TPOC_Conversion 3846 : TPOC_Call)) 3847 return BetterTemplate == Cand1.Function->getPrimaryTemplate(); 3848 3849 // -- the context is an initialization by user-defined conversion 3850 // (see 8.5, 13.3.1.5) and the standard conversion sequence 3851 // from the return type of F1 to the destination type (i.e., 3852 // the type of the entity being initialized) is a better 3853 // conversion sequence than the standard conversion sequence 3854 // from the return type of F2 to the destination type. 3855 if (Cand1.Function && Cand2.Function && 3856 isa<CXXConversionDecl>(Cand1.Function) && 3857 isa<CXXConversionDecl>(Cand2.Function)) { 3858 switch (CompareStandardConversionSequences(Cand1.FinalConversion, 3859 Cand2.FinalConversion)) { 3860 case ImplicitConversionSequence::Better: 3861 // Cand1 has a better conversion sequence. 3862 return true; 3863 3864 case ImplicitConversionSequence::Worse: 3865 // Cand1 can't be better than Cand2. 3866 return false; 3867 3868 case ImplicitConversionSequence::Indistinguishable: 3869 // Do nothing 3870 break; 3871 } 3872 } 3873 3874 return false; 3875} 3876 3877/// \brief Computes the best viable function (C++ 13.3.3) 3878/// within an overload candidate set. 3879/// 3880/// \param CandidateSet the set of candidate functions. 3881/// 3882/// \param Loc the location of the function name (or operator symbol) for 3883/// which overload resolution occurs. 3884/// 3885/// \param Best f overload resolution was successful or found a deleted 3886/// function, Best points to the candidate function found. 3887/// 3888/// \returns The result of overload resolution. 3889Sema::OverloadingResult 3890Sema::BestViableFunction(OverloadCandidateSet& CandidateSet, 3891 SourceLocation Loc, 3892 OverloadCandidateSet::iterator& Best) { 3893 // Find the best viable function. 3894 Best = CandidateSet.end(); 3895 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 3896 Cand != CandidateSet.end(); ++Cand) { 3897 if (Cand->Viable) { 3898 if (Best == CandidateSet.end() || isBetterOverloadCandidate(*Cand, *Best)) 3899 Best = Cand; 3900 } 3901 } 3902 3903 // If we didn't find any viable functions, abort. 3904 if (Best == CandidateSet.end()) 3905 return OR_No_Viable_Function; 3906 3907 // Make sure that this function is better than every other viable 3908 // function. If not, we have an ambiguity. 3909 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 3910 Cand != CandidateSet.end(); ++Cand) { 3911 if (Cand->Viable && 3912 Cand != Best && 3913 !isBetterOverloadCandidate(*Best, *Cand)) { 3914 Best = CandidateSet.end(); 3915 return OR_Ambiguous; 3916 } 3917 } 3918 3919 // Best is the best viable function. 3920 if (Best->Function && 3921 (Best->Function->isDeleted() || 3922 Best->Function->getAttr<UnavailableAttr>())) 3923 return OR_Deleted; 3924 3925 // C++ [basic.def.odr]p2: 3926 // An overloaded function is used if it is selected by overload resolution 3927 // when referred to from a potentially-evaluated expression. [Note: this 3928 // covers calls to named functions (5.2.2), operator overloading 3929 // (clause 13), user-defined conversions (12.3.2), allocation function for 3930 // placement new (5.3.4), as well as non-default initialization (8.5). 3931 if (Best->Function) 3932 MarkDeclarationReferenced(Loc, Best->Function); 3933 return OR_Success; 3934} 3935 3936/// PrintOverloadCandidates - When overload resolution fails, prints 3937/// diagnostic messages containing the candidates in the candidate 3938/// set. If OnlyViable is true, only viable candidates will be printed. 3939void 3940Sema::PrintOverloadCandidates(OverloadCandidateSet& CandidateSet, 3941 bool OnlyViable) { 3942 OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 3943 LastCand = CandidateSet.end(); 3944 for (; Cand != LastCand; ++Cand) { 3945 if (Cand->Viable || !OnlyViable) { 3946 if (Cand->Function) { 3947 if (Cand->Function->isDeleted() || 3948 Cand->Function->getAttr<UnavailableAttr>()) { 3949 // Deleted or "unavailable" function. 3950 Diag(Cand->Function->getLocation(), diag::err_ovl_candidate_deleted) 3951 << Cand->Function->isDeleted(); 3952 } else if (FunctionTemplateDecl *FunTmpl 3953 = Cand->Function->getPrimaryTemplate()) { 3954 // Function template specialization 3955 // FIXME: Give a better reason! 3956 Diag(Cand->Function->getLocation(), diag::err_ovl_template_candidate) 3957 << getTemplateArgumentBindingsText(FunTmpl->getTemplateParameters(), 3958 *Cand->Function->getTemplateSpecializationArgs()); 3959 } else { 3960 // Normal function 3961 bool errReported = false; 3962 if (!Cand->Viable && Cand->Conversions.size() > 0) { 3963 for (int i = Cand->Conversions.size()-1; i >= 0; i--) { 3964 const ImplicitConversionSequence &Conversion = 3965 Cand->Conversions[i]; 3966 if ((Conversion.ConversionKind != 3967 ImplicitConversionSequence::BadConversion) || 3968 Conversion.ConversionFunctionSet.size() == 0) 3969 continue; 3970 Diag(Cand->Function->getLocation(), 3971 diag::err_ovl_candidate_not_viable) << (i+1); 3972 errReported = true; 3973 for (int j = Conversion.ConversionFunctionSet.size()-1; 3974 j >= 0; j--) { 3975 FunctionDecl *Func = Conversion.ConversionFunctionSet[j]; 3976 Diag(Func->getLocation(), diag::err_ovl_candidate); 3977 } 3978 } 3979 } 3980 if (!errReported) 3981 Diag(Cand->Function->getLocation(), diag::err_ovl_candidate); 3982 } 3983 } else if (Cand->IsSurrogate) { 3984 // Desugar the type of the surrogate down to a function type, 3985 // retaining as many typedefs as possible while still showing 3986 // the function type (and, therefore, its parameter types). 3987 QualType FnType = Cand->Surrogate->getConversionType(); 3988 bool isLValueReference = false; 3989 bool isRValueReference = false; 3990 bool isPointer = false; 3991 if (const LValueReferenceType *FnTypeRef = 3992 FnType->getAs<LValueReferenceType>()) { 3993 FnType = FnTypeRef->getPointeeType(); 3994 isLValueReference = true; 3995 } else if (const RValueReferenceType *FnTypeRef = 3996 FnType->getAs<RValueReferenceType>()) { 3997 FnType = FnTypeRef->getPointeeType(); 3998 isRValueReference = true; 3999 } 4000 if (const PointerType *FnTypePtr = FnType->getAs<PointerType>()) { 4001 FnType = FnTypePtr->getPointeeType(); 4002 isPointer = true; 4003 } 4004 // Desugar down to a function type. 4005 FnType = QualType(FnType->getAs<FunctionType>(), 0); 4006 // Reconstruct the pointer/reference as appropriate. 4007 if (isPointer) FnType = Context.getPointerType(FnType); 4008 if (isRValueReference) FnType = Context.getRValueReferenceType(FnType); 4009 if (isLValueReference) FnType = Context.getLValueReferenceType(FnType); 4010 4011 Diag(Cand->Surrogate->getLocation(), diag::err_ovl_surrogate_cand) 4012 << FnType; 4013 } else if (OnlyViable) { 4014 // FIXME: We need to get the identifier in here 4015 // FIXME: Do we want the error message to point at the operator? 4016 // (built-ins won't have a location) 4017 // FIXME: can we get some kind of stable location for this? 4018 QualType FnType 4019 = Context.getFunctionType(Cand->BuiltinTypes.ResultTy, 4020 Cand->BuiltinTypes.ParamTypes, 4021 Cand->Conversions.size(), 4022 false, 0); 4023 4024 Diag(SourceLocation(), diag::err_ovl_builtin_candidate) << FnType; 4025 } 4026 } 4027 } 4028} 4029 4030/// ResolveAddressOfOverloadedFunction - Try to resolve the address of 4031/// an overloaded function (C++ [over.over]), where @p From is an 4032/// expression with overloaded function type and @p ToType is the type 4033/// we're trying to resolve to. For example: 4034/// 4035/// @code 4036/// int f(double); 4037/// int f(int); 4038/// 4039/// int (*pfd)(double) = f; // selects f(double) 4040/// @endcode 4041/// 4042/// This routine returns the resulting FunctionDecl if it could be 4043/// resolved, and NULL otherwise. When @p Complain is true, this 4044/// routine will emit diagnostics if there is an error. 4045FunctionDecl * 4046Sema::ResolveAddressOfOverloadedFunction(Expr *From, QualType ToType, 4047 bool Complain) { 4048 QualType FunctionType = ToType; 4049 bool IsMember = false; 4050 if (const PointerType *ToTypePtr = ToType->getAs<PointerType>()) 4051 FunctionType = ToTypePtr->getPointeeType(); 4052 else if (const ReferenceType *ToTypeRef = ToType->getAs<ReferenceType>()) 4053 FunctionType = ToTypeRef->getPointeeType(); 4054 else if (const MemberPointerType *MemTypePtr = 4055 ToType->getAs<MemberPointerType>()) { 4056 FunctionType = MemTypePtr->getPointeeType(); 4057 IsMember = true; 4058 } 4059 4060 // We only look at pointers or references to functions. 4061 FunctionType = Context.getCanonicalType(FunctionType).getUnqualifiedType(); 4062 if (!FunctionType->isFunctionType()) 4063 return 0; 4064 4065 // Find the actual overloaded function declaration. 4066 OverloadedFunctionDecl *Ovl = 0; 4067 4068 // C++ [over.over]p1: 4069 // [...] [Note: any redundant set of parentheses surrounding the 4070 // overloaded function name is ignored (5.1). ] 4071 Expr *OvlExpr = From->IgnoreParens(); 4072 4073 // C++ [over.over]p1: 4074 // [...] The overloaded function name can be preceded by the & 4075 // operator. 4076 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(OvlExpr)) { 4077 if (UnOp->getOpcode() == UnaryOperator::AddrOf) 4078 OvlExpr = UnOp->getSubExpr()->IgnoreParens(); 4079 } 4080 4081 // Try to dig out the overloaded function. 4082 FunctionTemplateDecl *FunctionTemplate = 0; 4083 if (DeclRefExpr *DR = dyn_cast<DeclRefExpr>(OvlExpr)) { 4084 Ovl = dyn_cast<OverloadedFunctionDecl>(DR->getDecl()); 4085 FunctionTemplate = dyn_cast<FunctionTemplateDecl>(DR->getDecl()); 4086 } 4087 4088 // If there's no overloaded function declaration or function template, 4089 // we're done. 4090 if (!Ovl && !FunctionTemplate) 4091 return 0; 4092 4093 OverloadIterator Fun; 4094 if (Ovl) 4095 Fun = Ovl; 4096 else 4097 Fun = FunctionTemplate; 4098 4099 // Look through all of the overloaded functions, searching for one 4100 // whose type matches exactly. 4101 llvm::SmallPtrSet<FunctionDecl *, 4> Matches; 4102 bool FoundNonTemplateFunction = false; 4103 for (OverloadIterator FunEnd; Fun != FunEnd; ++Fun) { 4104 // C++ [over.over]p3: 4105 // Non-member functions and static member functions match 4106 // targets of type "pointer-to-function" or "reference-to-function." 4107 // Nonstatic member functions match targets of 4108 // type "pointer-to-member-function." 4109 // Note that according to DR 247, the containing class does not matter. 4110 4111 if (FunctionTemplateDecl *FunctionTemplate 4112 = dyn_cast<FunctionTemplateDecl>(*Fun)) { 4113 if (CXXMethodDecl *Method 4114 = dyn_cast<CXXMethodDecl>(FunctionTemplate->getTemplatedDecl())) { 4115 // Skip non-static function templates when converting to pointer, and 4116 // static when converting to member pointer. 4117 if (Method->isStatic() == IsMember) 4118 continue; 4119 } else if (IsMember) 4120 continue; 4121 4122 // C++ [over.over]p2: 4123 // If the name is a function template, template argument deduction is 4124 // done (14.8.2.2), and if the argument deduction succeeds, the 4125 // resulting template argument list is used to generate a single 4126 // function template specialization, which is added to the set of 4127 // overloaded functions considered. 4128 // FIXME: We don't really want to build the specialization here, do we? 4129 FunctionDecl *Specialization = 0; 4130 TemplateDeductionInfo Info(Context); 4131 if (TemplateDeductionResult Result 4132 = DeduceTemplateArguments(FunctionTemplate, /*FIXME*/false, 4133 /*FIXME:*/0, /*FIXME:*/0, 4134 FunctionType, Specialization, Info)) { 4135 // FIXME: make a note of the failed deduction for diagnostics. 4136 (void)Result; 4137 } else { 4138 // FIXME: If the match isn't exact, shouldn't we just drop this as 4139 // a candidate? Find a testcase before changing the code. 4140 assert(FunctionType 4141 == Context.getCanonicalType(Specialization->getType())); 4142 Matches.insert( 4143 cast<FunctionDecl>(Specialization->getCanonicalDecl())); 4144 } 4145 } 4146 4147 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(*Fun)) { 4148 // Skip non-static functions when converting to pointer, and static 4149 // when converting to member pointer. 4150 if (Method->isStatic() == IsMember) 4151 continue; 4152 } else if (IsMember) 4153 continue; 4154 4155 if (FunctionDecl *FunDecl = dyn_cast<FunctionDecl>(*Fun)) { 4156 if (FunctionType == Context.getCanonicalType(FunDecl->getType())) { 4157 Matches.insert(cast<FunctionDecl>(Fun->getCanonicalDecl())); 4158 FoundNonTemplateFunction = true; 4159 } 4160 } 4161 } 4162 4163 // If there were 0 or 1 matches, we're done. 4164 if (Matches.empty()) 4165 return 0; 4166 else if (Matches.size() == 1) 4167 return *Matches.begin(); 4168 4169 // C++ [over.over]p4: 4170 // If more than one function is selected, [...] 4171 typedef llvm::SmallPtrSet<FunctionDecl *, 4>::iterator MatchIter; 4172 if (!FoundNonTemplateFunction) { 4173 // [...] and any given function template specialization F1 is 4174 // eliminated if the set contains a second function template 4175 // specialization whose function template is more specialized 4176 // than the function template of F1 according to the partial 4177 // ordering rules of 14.5.5.2. 4178 4179 // The algorithm specified above is quadratic. We instead use a 4180 // two-pass algorithm (similar to the one used to identify the 4181 // best viable function in an overload set) that identifies the 4182 // best function template (if it exists). 4183 llvm::SmallVector<FunctionDecl *, 8> TemplateMatches(Matches.begin(), 4184 Matches.end()); 4185 return getMostSpecialized(TemplateMatches.data(), TemplateMatches.size(), 4186 TPOC_Other, From->getLocStart(), 4187 PartialDiagnostic(0), 4188 PartialDiagnostic(diag::err_addr_ovl_ambiguous) 4189 << TemplateMatches[0]->getDeclName(), 4190 PartialDiagnostic(diag::err_ovl_template_candidate)); 4191 } 4192 4193 // [...] any function template specializations in the set are 4194 // eliminated if the set also contains a non-template function, [...] 4195 llvm::SmallVector<FunctionDecl *, 4> RemainingMatches; 4196 for (MatchIter M = Matches.begin(), MEnd = Matches.end(); M != MEnd; ++M) 4197 if ((*M)->getPrimaryTemplate() == 0) 4198 RemainingMatches.push_back(*M); 4199 4200 // [...] After such eliminations, if any, there shall remain exactly one 4201 // selected function. 4202 if (RemainingMatches.size() == 1) 4203 return RemainingMatches.front(); 4204 4205 // FIXME: We should probably return the same thing that BestViableFunction 4206 // returns (even if we issue the diagnostics here). 4207 Diag(From->getLocStart(), diag::err_addr_ovl_ambiguous) 4208 << RemainingMatches[0]->getDeclName(); 4209 for (unsigned I = 0, N = RemainingMatches.size(); I != N; ++I) 4210 Diag(RemainingMatches[I]->getLocation(), diag::err_ovl_candidate); 4211 return 0; 4212} 4213 4214/// \brief Add a single candidate to the overload set. 4215static void AddOverloadedCallCandidate(Sema &S, 4216 AnyFunctionDecl Callee, 4217 bool &ArgumentDependentLookup, 4218 bool HasExplicitTemplateArgs, 4219 const TemplateArgument *ExplicitTemplateArgs, 4220 unsigned NumExplicitTemplateArgs, 4221 Expr **Args, unsigned NumArgs, 4222 OverloadCandidateSet &CandidateSet, 4223 bool PartialOverloading) { 4224 if (FunctionDecl *Func = dyn_cast<FunctionDecl>(Callee)) { 4225 assert(!HasExplicitTemplateArgs && "Explicit template arguments?"); 4226 S.AddOverloadCandidate(Func, Args, NumArgs, CandidateSet, false, false, 4227 PartialOverloading); 4228 4229 if (Func->getDeclContext()->isRecord() || 4230 Func->getDeclContext()->isFunctionOrMethod()) 4231 ArgumentDependentLookup = false; 4232 return; 4233 } 4234 4235 FunctionTemplateDecl *FuncTemplate = cast<FunctionTemplateDecl>(Callee); 4236 S.AddTemplateOverloadCandidate(FuncTemplate, HasExplicitTemplateArgs, 4237 ExplicitTemplateArgs, 4238 NumExplicitTemplateArgs, 4239 Args, NumArgs, CandidateSet); 4240 4241 if (FuncTemplate->getDeclContext()->isRecord()) 4242 ArgumentDependentLookup = false; 4243} 4244 4245/// \brief Add the overload candidates named by callee and/or found by argument 4246/// dependent lookup to the given overload set. 4247void Sema::AddOverloadedCallCandidates(NamedDecl *Callee, 4248 DeclarationName &UnqualifiedName, 4249 bool &ArgumentDependentLookup, 4250 bool HasExplicitTemplateArgs, 4251 const TemplateArgument *ExplicitTemplateArgs, 4252 unsigned NumExplicitTemplateArgs, 4253 Expr **Args, unsigned NumArgs, 4254 OverloadCandidateSet &CandidateSet, 4255 bool PartialOverloading) { 4256 // Add the functions denoted by Callee to the set of candidate 4257 // functions. While we're doing so, track whether argument-dependent 4258 // lookup still applies, per: 4259 // 4260 // C++0x [basic.lookup.argdep]p3: 4261 // Let X be the lookup set produced by unqualified lookup (3.4.1) 4262 // and let Y be the lookup set produced by argument dependent 4263 // lookup (defined as follows). If X contains 4264 // 4265 // -- a declaration of a class member, or 4266 // 4267 // -- a block-scope function declaration that is not a 4268 // using-declaration (FIXME: check for using declaration), or 4269 // 4270 // -- a declaration that is neither a function or a function 4271 // template 4272 // 4273 // then Y is empty. 4274 if (!Callee) { 4275 // Nothing to do. 4276 } else if (OverloadedFunctionDecl *Ovl 4277 = dyn_cast<OverloadedFunctionDecl>(Callee)) { 4278 for (OverloadedFunctionDecl::function_iterator Func = Ovl->function_begin(), 4279 FuncEnd = Ovl->function_end(); 4280 Func != FuncEnd; ++Func) 4281 AddOverloadedCallCandidate(*this, *Func, ArgumentDependentLookup, 4282 HasExplicitTemplateArgs, 4283 ExplicitTemplateArgs, NumExplicitTemplateArgs, 4284 Args, NumArgs, CandidateSet, 4285 PartialOverloading); 4286 } else if (isa<FunctionDecl>(Callee) || isa<FunctionTemplateDecl>(Callee)) 4287 AddOverloadedCallCandidate(*this, 4288 AnyFunctionDecl::getFromNamedDecl(Callee), 4289 ArgumentDependentLookup, 4290 HasExplicitTemplateArgs, 4291 ExplicitTemplateArgs, NumExplicitTemplateArgs, 4292 Args, NumArgs, CandidateSet, 4293 PartialOverloading); 4294 // FIXME: assert isa<FunctionDecl> || isa<FunctionTemplateDecl> rather than 4295 // checking dynamically. 4296 4297 if (Callee) 4298 UnqualifiedName = Callee->getDeclName(); 4299 4300 if (ArgumentDependentLookup) 4301 AddArgumentDependentLookupCandidates(UnqualifiedName, Args, NumArgs, 4302 HasExplicitTemplateArgs, 4303 ExplicitTemplateArgs, 4304 NumExplicitTemplateArgs, 4305 CandidateSet, 4306 PartialOverloading); 4307} 4308 4309/// ResolveOverloadedCallFn - Given the call expression that calls Fn 4310/// (which eventually refers to the declaration Func) and the call 4311/// arguments Args/NumArgs, attempt to resolve the function call down 4312/// to a specific function. If overload resolution succeeds, returns 4313/// the function declaration produced by overload 4314/// resolution. Otherwise, emits diagnostics, deletes all of the 4315/// arguments and Fn, and returns NULL. 4316FunctionDecl *Sema::ResolveOverloadedCallFn(Expr *Fn, NamedDecl *Callee, 4317 DeclarationName UnqualifiedName, 4318 bool HasExplicitTemplateArgs, 4319 const TemplateArgument *ExplicitTemplateArgs, 4320 unsigned NumExplicitTemplateArgs, 4321 SourceLocation LParenLoc, 4322 Expr **Args, unsigned NumArgs, 4323 SourceLocation *CommaLocs, 4324 SourceLocation RParenLoc, 4325 bool &ArgumentDependentLookup) { 4326 OverloadCandidateSet CandidateSet; 4327 4328 // Add the functions denoted by Callee to the set of candidate 4329 // functions. 4330 AddOverloadedCallCandidates(Callee, UnqualifiedName, ArgumentDependentLookup, 4331 HasExplicitTemplateArgs, ExplicitTemplateArgs, 4332 NumExplicitTemplateArgs, Args, NumArgs, 4333 CandidateSet); 4334 OverloadCandidateSet::iterator Best; 4335 switch (BestViableFunction(CandidateSet, Fn->getLocStart(), Best)) { 4336 case OR_Success: 4337 return Best->Function; 4338 4339 case OR_No_Viable_Function: 4340 Diag(Fn->getSourceRange().getBegin(), 4341 diag::err_ovl_no_viable_function_in_call) 4342 << UnqualifiedName << Fn->getSourceRange(); 4343 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4344 break; 4345 4346 case OR_Ambiguous: 4347 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_ambiguous_call) 4348 << UnqualifiedName << Fn->getSourceRange(); 4349 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4350 break; 4351 4352 case OR_Deleted: 4353 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_deleted_call) 4354 << Best->Function->isDeleted() 4355 << UnqualifiedName 4356 << Fn->getSourceRange(); 4357 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4358 break; 4359 } 4360 4361 // Overload resolution failed. Destroy all of the subexpressions and 4362 // return NULL. 4363 Fn->Destroy(Context); 4364 for (unsigned Arg = 0; Arg < NumArgs; ++Arg) 4365 Args[Arg]->Destroy(Context); 4366 return 0; 4367} 4368 4369/// \brief Create a unary operation that may resolve to an overloaded 4370/// operator. 4371/// 4372/// \param OpLoc The location of the operator itself (e.g., '*'). 4373/// 4374/// \param OpcIn The UnaryOperator::Opcode that describes this 4375/// operator. 4376/// 4377/// \param Functions The set of non-member functions that will be 4378/// considered by overload resolution. The caller needs to build this 4379/// set based on the context using, e.g., 4380/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 4381/// set should not contain any member functions; those will be added 4382/// by CreateOverloadedUnaryOp(). 4383/// 4384/// \param input The input argument. 4385Sema::OwningExprResult Sema::CreateOverloadedUnaryOp(SourceLocation OpLoc, 4386 unsigned OpcIn, 4387 FunctionSet &Functions, 4388 ExprArg input) { 4389 UnaryOperator::Opcode Opc = static_cast<UnaryOperator::Opcode>(OpcIn); 4390 Expr *Input = (Expr *)input.get(); 4391 4392 OverloadedOperatorKind Op = UnaryOperator::getOverloadedOperator(Opc); 4393 assert(Op != OO_None && "Invalid opcode for overloaded unary operator"); 4394 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 4395 4396 Expr *Args[2] = { Input, 0 }; 4397 unsigned NumArgs = 1; 4398 4399 // For post-increment and post-decrement, add the implicit '0' as 4400 // the second argument, so that we know this is a post-increment or 4401 // post-decrement. 4402 if (Opc == UnaryOperator::PostInc || Opc == UnaryOperator::PostDec) { 4403 llvm::APSInt Zero(Context.getTypeSize(Context.IntTy), false); 4404 Args[1] = new (Context) IntegerLiteral(Zero, Context.IntTy, 4405 SourceLocation()); 4406 NumArgs = 2; 4407 } 4408 4409 if (Input->isTypeDependent()) { 4410 OverloadedFunctionDecl *Overloads 4411 = OverloadedFunctionDecl::Create(Context, CurContext, OpName); 4412 for (FunctionSet::iterator Func = Functions.begin(), 4413 FuncEnd = Functions.end(); 4414 Func != FuncEnd; ++Func) 4415 Overloads->addOverload(*Func); 4416 4417 DeclRefExpr *Fn = new (Context) DeclRefExpr(Overloads, Context.OverloadTy, 4418 OpLoc, false, false); 4419 4420 input.release(); 4421 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 4422 &Args[0], NumArgs, 4423 Context.DependentTy, 4424 OpLoc)); 4425 } 4426 4427 // Build an empty overload set. 4428 OverloadCandidateSet CandidateSet; 4429 4430 // Add the candidates from the given function set. 4431 AddFunctionCandidates(Functions, &Args[0], NumArgs, CandidateSet, false); 4432 4433 // Add operator candidates that are member functions. 4434 AddMemberOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 4435 4436 // Add builtin operator candidates. 4437 AddBuiltinOperatorCandidates(Op, &Args[0], NumArgs, CandidateSet); 4438 4439 // Perform overload resolution. 4440 OverloadCandidateSet::iterator Best; 4441 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 4442 case OR_Success: { 4443 // We found a built-in operator or an overloaded operator. 4444 FunctionDecl *FnDecl = Best->Function; 4445 4446 if (FnDecl) { 4447 // We matched an overloaded operator. Build a call to that 4448 // operator. 4449 4450 // Convert the arguments. 4451 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 4452 if (PerformObjectArgumentInitialization(Input, Method)) 4453 return ExprError(); 4454 } else { 4455 // Convert the arguments. 4456 if (PerformCopyInitialization(Input, 4457 FnDecl->getParamDecl(0)->getType(), 4458 "passing")) 4459 return ExprError(); 4460 } 4461 4462 // Determine the result type 4463 QualType ResultTy 4464 = FnDecl->getType()->getAs<FunctionType>()->getResultType(); 4465 ResultTy = ResultTy.getNonReferenceType(); 4466 4467 // Build the actual expression node. 4468 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 4469 SourceLocation()); 4470 UsualUnaryConversions(FnExpr); 4471 4472 input.release(); 4473 4474 Expr *CE = new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 4475 &Input, 1, ResultTy, OpLoc); 4476 return MaybeBindToTemporary(CE); 4477 } else { 4478 // We matched a built-in operator. Convert the arguments, then 4479 // break out so that we will build the appropriate built-in 4480 // operator node. 4481 if (PerformImplicitConversion(Input, Best->BuiltinTypes.ParamTypes[0], 4482 Best->Conversions[0], "passing")) 4483 return ExprError(); 4484 4485 break; 4486 } 4487 } 4488 4489 case OR_No_Viable_Function: 4490 // No viable function; fall through to handling this as a 4491 // built-in operator, which will produce an error message for us. 4492 break; 4493 4494 case OR_Ambiguous: 4495 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 4496 << UnaryOperator::getOpcodeStr(Opc) 4497 << Input->getSourceRange(); 4498 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4499 return ExprError(); 4500 4501 case OR_Deleted: 4502 Diag(OpLoc, diag::err_ovl_deleted_oper) 4503 << Best->Function->isDeleted() 4504 << UnaryOperator::getOpcodeStr(Opc) 4505 << Input->getSourceRange(); 4506 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4507 return ExprError(); 4508 } 4509 4510 // Either we found no viable overloaded operator or we matched a 4511 // built-in operator. In either case, fall through to trying to 4512 // build a built-in operation. 4513 input.release(); 4514 return CreateBuiltinUnaryOp(OpLoc, Opc, Owned(Input)); 4515} 4516 4517/// \brief Create a binary operation that may resolve to an overloaded 4518/// operator. 4519/// 4520/// \param OpLoc The location of the operator itself (e.g., '+'). 4521/// 4522/// \param OpcIn The BinaryOperator::Opcode that describes this 4523/// operator. 4524/// 4525/// \param Functions The set of non-member functions that will be 4526/// considered by overload resolution. The caller needs to build this 4527/// set based on the context using, e.g., 4528/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 4529/// set should not contain any member functions; those will be added 4530/// by CreateOverloadedBinOp(). 4531/// 4532/// \param LHS Left-hand argument. 4533/// \param RHS Right-hand argument. 4534Sema::OwningExprResult 4535Sema::CreateOverloadedBinOp(SourceLocation OpLoc, 4536 unsigned OpcIn, 4537 FunctionSet &Functions, 4538 Expr *LHS, Expr *RHS) { 4539 Expr *Args[2] = { LHS, RHS }; 4540 LHS=RHS=0; //Please use only Args instead of LHS/RHS couple 4541 4542 BinaryOperator::Opcode Opc = static_cast<BinaryOperator::Opcode>(OpcIn); 4543 OverloadedOperatorKind Op = BinaryOperator::getOverloadedOperator(Opc); 4544 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 4545 4546 // If either side is type-dependent, create an appropriate dependent 4547 // expression. 4548 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 4549 // .* cannot be overloaded. 4550 if (Opc == BinaryOperator::PtrMemD) 4551 return Owned(new (Context) BinaryOperator(Args[0], Args[1], Opc, 4552 Context.DependentTy, OpLoc)); 4553 4554 OverloadedFunctionDecl *Overloads 4555 = OverloadedFunctionDecl::Create(Context, CurContext, OpName); 4556 for (FunctionSet::iterator Func = Functions.begin(), 4557 FuncEnd = Functions.end(); 4558 Func != FuncEnd; ++Func) 4559 Overloads->addOverload(*Func); 4560 4561 DeclRefExpr *Fn = new (Context) DeclRefExpr(Overloads, Context.OverloadTy, 4562 OpLoc, false, false); 4563 4564 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 4565 Args, 2, 4566 Context.DependentTy, 4567 OpLoc)); 4568 } 4569 4570 // If this is the .* operator, which is not overloadable, just 4571 // create a built-in binary operator. 4572 if (Opc == BinaryOperator::PtrMemD) 4573 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 4574 4575 // If this is one of the assignment operators, we only perform 4576 // overload resolution if the left-hand side is a class or 4577 // enumeration type (C++ [expr.ass]p3). 4578 if (Opc >= BinaryOperator::Assign && Opc <= BinaryOperator::OrAssign && 4579 !Args[0]->getType()->isOverloadableType()) 4580 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 4581 4582 // Build an empty overload set. 4583 OverloadCandidateSet CandidateSet; 4584 4585 // Add the candidates from the given function set. 4586 AddFunctionCandidates(Functions, Args, 2, CandidateSet, false); 4587 4588 // Add operator candidates that are member functions. 4589 AddMemberOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 4590 4591 // Add builtin operator candidates. 4592 AddBuiltinOperatorCandidates(Op, Args, 2, CandidateSet); 4593 4594 // Perform overload resolution. 4595 OverloadCandidateSet::iterator Best; 4596 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 4597 case OR_Success: { 4598 // We found a built-in operator or an overloaded operator. 4599 FunctionDecl *FnDecl = Best->Function; 4600 4601 if (FnDecl) { 4602 // We matched an overloaded operator. Build a call to that 4603 // operator. 4604 4605 // Convert the arguments. 4606 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 4607 if (PerformObjectArgumentInitialization(Args[0], Method) || 4608 PerformCopyInitialization(Args[1], FnDecl->getParamDecl(0)->getType(), 4609 "passing")) 4610 return ExprError(); 4611 } else { 4612 // Convert the arguments. 4613 if (PerformCopyInitialization(Args[0], FnDecl->getParamDecl(0)->getType(), 4614 "passing") || 4615 PerformCopyInitialization(Args[1], FnDecl->getParamDecl(1)->getType(), 4616 "passing")) 4617 return ExprError(); 4618 } 4619 4620 // Determine the result type 4621 QualType ResultTy 4622 = FnDecl->getType()->getAs<FunctionType>()->getResultType(); 4623 ResultTy = ResultTy.getNonReferenceType(); 4624 4625 // Build the actual expression node. 4626 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 4627 OpLoc); 4628 UsualUnaryConversions(FnExpr); 4629 4630 Expr *CE = new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 4631 Args, 2, ResultTy, OpLoc); 4632 return MaybeBindToTemporary(CE); 4633 } else { 4634 // We matched a built-in operator. Convert the arguments, then 4635 // break out so that we will build the appropriate built-in 4636 // operator node. 4637 if (PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 4638 Best->Conversions[0], "passing") || 4639 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 4640 Best->Conversions[1], "passing")) 4641 return ExprError(); 4642 4643 break; 4644 } 4645 } 4646 4647 case OR_No_Viable_Function: { 4648 // C++ [over.match.oper]p9: 4649 // If the operator is the operator , [...] and there are no 4650 // viable functions, then the operator is assumed to be the 4651 // built-in operator and interpreted according to clause 5. 4652 if (Opc == BinaryOperator::Comma) 4653 break; 4654 4655 // For class as left operand for assignment or compound assigment operator 4656 // do not fall through to handling in built-in, but report that no overloaded 4657 // assignment operator found 4658 OwningExprResult Result = ExprError(); 4659 if (Args[0]->getType()->isRecordType() && 4660 Opc >= BinaryOperator::Assign && Opc <= BinaryOperator::OrAssign) { 4661 Diag(OpLoc, diag::err_ovl_no_viable_oper) 4662 << BinaryOperator::getOpcodeStr(Opc) 4663 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 4664 } else { 4665 // No viable function; try to create a built-in operation, which will 4666 // produce an error. Then, show the non-viable candidates. 4667 Result = CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 4668 } 4669 assert(Result.isInvalid() && 4670 "C++ binary operator overloading is missing candidates!"); 4671 if (Result.isInvalid()) 4672 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4673 return move(Result); 4674 } 4675 4676 case OR_Ambiguous: 4677 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 4678 << BinaryOperator::getOpcodeStr(Opc) 4679 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 4680 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4681 return ExprError(); 4682 4683 case OR_Deleted: 4684 Diag(OpLoc, diag::err_ovl_deleted_oper) 4685 << Best->Function->isDeleted() 4686 << BinaryOperator::getOpcodeStr(Opc) 4687 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 4688 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4689 return ExprError(); 4690 } 4691 4692 // We matched a built-in operator; build it. 4693 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 4694} 4695 4696/// BuildCallToMemberFunction - Build a call to a member 4697/// function. MemExpr is the expression that refers to the member 4698/// function (and includes the object parameter), Args/NumArgs are the 4699/// arguments to the function call (not including the object 4700/// parameter). The caller needs to validate that the member 4701/// expression refers to a member function or an overloaded member 4702/// function. 4703Sema::ExprResult 4704Sema::BuildCallToMemberFunction(Scope *S, Expr *MemExprE, 4705 SourceLocation LParenLoc, Expr **Args, 4706 unsigned NumArgs, SourceLocation *CommaLocs, 4707 SourceLocation RParenLoc) { 4708 // Dig out the member expression. This holds both the object 4709 // argument and the member function we're referring to. 4710 MemberExpr *MemExpr = 0; 4711 if (ParenExpr *ParenE = dyn_cast<ParenExpr>(MemExprE)) 4712 MemExpr = dyn_cast<MemberExpr>(ParenE->getSubExpr()); 4713 else 4714 MemExpr = dyn_cast<MemberExpr>(MemExprE); 4715 assert(MemExpr && "Building member call without member expression"); 4716 4717 // Extract the object argument. 4718 Expr *ObjectArg = MemExpr->getBase(); 4719 4720 CXXMethodDecl *Method = 0; 4721 if (isa<OverloadedFunctionDecl>(MemExpr->getMemberDecl()) || 4722 isa<FunctionTemplateDecl>(MemExpr->getMemberDecl())) { 4723 // Add overload candidates 4724 OverloadCandidateSet CandidateSet; 4725 DeclarationName DeclName = MemExpr->getMemberDecl()->getDeclName(); 4726 4727 for (OverloadIterator Func(MemExpr->getMemberDecl()), FuncEnd; 4728 Func != FuncEnd; ++Func) { 4729 if ((Method = dyn_cast<CXXMethodDecl>(*Func))) 4730 AddMethodCandidate(Method, ObjectArg, Args, NumArgs, CandidateSet, 4731 /*SuppressUserConversions=*/false); 4732 else 4733 AddMethodTemplateCandidate(cast<FunctionTemplateDecl>(*Func), 4734 MemExpr->hasExplicitTemplateArgumentList(), 4735 MemExpr->getTemplateArgs(), 4736 MemExpr->getNumTemplateArgs(), 4737 ObjectArg, Args, NumArgs, 4738 CandidateSet, 4739 /*SuppressUsedConversions=*/false); 4740 } 4741 4742 OverloadCandidateSet::iterator Best; 4743 switch (BestViableFunction(CandidateSet, MemExpr->getLocStart(), Best)) { 4744 case OR_Success: 4745 Method = cast<CXXMethodDecl>(Best->Function); 4746 break; 4747 4748 case OR_No_Viable_Function: 4749 Diag(MemExpr->getSourceRange().getBegin(), 4750 diag::err_ovl_no_viable_member_function_in_call) 4751 << DeclName << MemExprE->getSourceRange(); 4752 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4753 // FIXME: Leaking incoming expressions! 4754 return true; 4755 4756 case OR_Ambiguous: 4757 Diag(MemExpr->getSourceRange().getBegin(), 4758 diag::err_ovl_ambiguous_member_call) 4759 << DeclName << MemExprE->getSourceRange(); 4760 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4761 // FIXME: Leaking incoming expressions! 4762 return true; 4763 4764 case OR_Deleted: 4765 Diag(MemExpr->getSourceRange().getBegin(), 4766 diag::err_ovl_deleted_member_call) 4767 << Best->Function->isDeleted() 4768 << DeclName << MemExprE->getSourceRange(); 4769 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4770 // FIXME: Leaking incoming expressions! 4771 return true; 4772 } 4773 4774 FixOverloadedFunctionReference(MemExpr, Method); 4775 } else { 4776 Method = dyn_cast<CXXMethodDecl>(MemExpr->getMemberDecl()); 4777 } 4778 4779 assert(Method && "Member call to something that isn't a method?"); 4780 ExprOwningPtr<CXXMemberCallExpr> 4781 TheCall(this, new (Context) CXXMemberCallExpr(Context, MemExpr, Args, 4782 NumArgs, 4783 Method->getResultType().getNonReferenceType(), 4784 RParenLoc)); 4785 4786 // Convert the object argument (for a non-static member function call). 4787 if (!Method->isStatic() && 4788 PerformObjectArgumentInitialization(ObjectArg, Method)) 4789 return true; 4790 MemExpr->setBase(ObjectArg); 4791 4792 // Convert the rest of the arguments 4793 const FunctionProtoType *Proto = cast<FunctionProtoType>(Method->getType()); 4794 if (ConvertArgumentsForCall(&*TheCall, MemExpr, Method, Proto, Args, NumArgs, 4795 RParenLoc)) 4796 return true; 4797 4798 if (CheckFunctionCall(Method, TheCall.get())) 4799 return true; 4800 4801 return MaybeBindToTemporary(TheCall.release()).release(); 4802} 4803 4804/// BuildCallToObjectOfClassType - Build a call to an object of class 4805/// type (C++ [over.call.object]), which can end up invoking an 4806/// overloaded function call operator (@c operator()) or performing a 4807/// user-defined conversion on the object argument. 4808Sema::ExprResult 4809Sema::BuildCallToObjectOfClassType(Scope *S, Expr *Object, 4810 SourceLocation LParenLoc, 4811 Expr **Args, unsigned NumArgs, 4812 SourceLocation *CommaLocs, 4813 SourceLocation RParenLoc) { 4814 assert(Object->getType()->isRecordType() && "Requires object type argument"); 4815 const RecordType *Record = Object->getType()->getAs<RecordType>(); 4816 4817 // C++ [over.call.object]p1: 4818 // If the primary-expression E in the function call syntax 4819 // evaluates to a class object of type "cv T", then the set of 4820 // candidate functions includes at least the function call 4821 // operators of T. The function call operators of T are obtained by 4822 // ordinary lookup of the name operator() in the context of 4823 // (E).operator(). 4824 OverloadCandidateSet CandidateSet; 4825 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Call); 4826 DeclContext::lookup_const_iterator Oper, OperEnd; 4827 for (llvm::tie(Oper, OperEnd) = Record->getDecl()->lookup(OpName); 4828 Oper != OperEnd; ++Oper) 4829 AddMethodCandidate(cast<CXXMethodDecl>(*Oper), Object, Args, NumArgs, 4830 CandidateSet, /*SuppressUserConversions=*/false); 4831 4832 // C++ [over.call.object]p2: 4833 // In addition, for each conversion function declared in T of the 4834 // form 4835 // 4836 // operator conversion-type-id () cv-qualifier; 4837 // 4838 // where cv-qualifier is the same cv-qualification as, or a 4839 // greater cv-qualification than, cv, and where conversion-type-id 4840 // denotes the type "pointer to function of (P1,...,Pn) returning 4841 // R", or the type "reference to pointer to function of 4842 // (P1,...,Pn) returning R", or the type "reference to function 4843 // of (P1,...,Pn) returning R", a surrogate call function [...] 4844 // is also considered as a candidate function. Similarly, 4845 // surrogate call functions are added to the set of candidate 4846 // functions for each conversion function declared in an 4847 // accessible base class provided the function is not hidden 4848 // within T by another intervening declaration. 4849 4850 if (!RequireCompleteType(SourceLocation(), Object->getType(), 0)) { 4851 // FIXME: Look in base classes for more conversion operators! 4852 OverloadedFunctionDecl *Conversions 4853 = cast<CXXRecordDecl>(Record->getDecl())->getConversionFunctions(); 4854 for (OverloadedFunctionDecl::function_iterator 4855 Func = Conversions->function_begin(), 4856 FuncEnd = Conversions->function_end(); 4857 Func != FuncEnd; ++Func) { 4858 CXXConversionDecl *Conv; 4859 FunctionTemplateDecl *ConvTemplate; 4860 GetFunctionAndTemplate(*Func, Conv, ConvTemplate); 4861 4862 // Skip over templated conversion functions; they aren't 4863 // surrogates. 4864 if (ConvTemplate) 4865 continue; 4866 4867 // Strip the reference type (if any) and then the pointer type (if 4868 // any) to get down to what might be a function type. 4869 QualType ConvType = Conv->getConversionType().getNonReferenceType(); 4870 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 4871 ConvType = ConvPtrType->getPointeeType(); 4872 4873 if (const FunctionProtoType *Proto = ConvType->getAs<FunctionProtoType>()) 4874 AddSurrogateCandidate(Conv, Proto, Object, Args, NumArgs, CandidateSet); 4875 } 4876 } 4877 4878 // Perform overload resolution. 4879 OverloadCandidateSet::iterator Best; 4880 switch (BestViableFunction(CandidateSet, Object->getLocStart(), Best)) { 4881 case OR_Success: 4882 // Overload resolution succeeded; we'll build the appropriate call 4883 // below. 4884 break; 4885 4886 case OR_No_Viable_Function: 4887 Diag(Object->getSourceRange().getBegin(), 4888 diag::err_ovl_no_viable_object_call) 4889 << Object->getType() << Object->getSourceRange(); 4890 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4891 break; 4892 4893 case OR_Ambiguous: 4894 Diag(Object->getSourceRange().getBegin(), 4895 diag::err_ovl_ambiguous_object_call) 4896 << Object->getType() << Object->getSourceRange(); 4897 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4898 break; 4899 4900 case OR_Deleted: 4901 Diag(Object->getSourceRange().getBegin(), 4902 diag::err_ovl_deleted_object_call) 4903 << Best->Function->isDeleted() 4904 << Object->getType() << Object->getSourceRange(); 4905 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4906 break; 4907 } 4908 4909 if (Best == CandidateSet.end()) { 4910 // We had an error; delete all of the subexpressions and return 4911 // the error. 4912 Object->Destroy(Context); 4913 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 4914 Args[ArgIdx]->Destroy(Context); 4915 return true; 4916 } 4917 4918 if (Best->Function == 0) { 4919 // Since there is no function declaration, this is one of the 4920 // surrogate candidates. Dig out the conversion function. 4921 CXXConversionDecl *Conv 4922 = cast<CXXConversionDecl>( 4923 Best->Conversions[0].UserDefined.ConversionFunction); 4924 4925 // We selected one of the surrogate functions that converts the 4926 // object parameter to a function pointer. Perform the conversion 4927 // on the object argument, then let ActOnCallExpr finish the job. 4928 4929 // Create an implicit member expr to refer to the conversion operator. 4930 // and then call it. 4931 CXXMemberCallExpr *CE = 4932 BuildCXXMemberCallExpr(Object, Conv); 4933 4934 return ActOnCallExpr(S, ExprArg(*this, CE), LParenLoc, 4935 MultiExprArg(*this, (ExprTy**)Args, NumArgs), 4936 CommaLocs, RParenLoc).release(); 4937 } 4938 4939 // We found an overloaded operator(). Build a CXXOperatorCallExpr 4940 // that calls this method, using Object for the implicit object 4941 // parameter and passing along the remaining arguments. 4942 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 4943 const FunctionProtoType *Proto = Method->getType()->getAs<FunctionProtoType>(); 4944 4945 unsigned NumArgsInProto = Proto->getNumArgs(); 4946 unsigned NumArgsToCheck = NumArgs; 4947 4948 // Build the full argument list for the method call (the 4949 // implicit object parameter is placed at the beginning of the 4950 // list). 4951 Expr **MethodArgs; 4952 if (NumArgs < NumArgsInProto) { 4953 NumArgsToCheck = NumArgsInProto; 4954 MethodArgs = new Expr*[NumArgsInProto + 1]; 4955 } else { 4956 MethodArgs = new Expr*[NumArgs + 1]; 4957 } 4958 MethodArgs[0] = Object; 4959 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 4960 MethodArgs[ArgIdx + 1] = Args[ArgIdx]; 4961 4962 Expr *NewFn = new (Context) DeclRefExpr(Method, Method->getType(), 4963 SourceLocation()); 4964 UsualUnaryConversions(NewFn); 4965 4966 // Once we've built TheCall, all of the expressions are properly 4967 // owned. 4968 QualType ResultTy = Method->getResultType().getNonReferenceType(); 4969 ExprOwningPtr<CXXOperatorCallExpr> 4970 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Call, NewFn, 4971 MethodArgs, NumArgs + 1, 4972 ResultTy, RParenLoc)); 4973 delete [] MethodArgs; 4974 4975 // We may have default arguments. If so, we need to allocate more 4976 // slots in the call for them. 4977 if (NumArgs < NumArgsInProto) 4978 TheCall->setNumArgs(Context, NumArgsInProto + 1); 4979 else if (NumArgs > NumArgsInProto) 4980 NumArgsToCheck = NumArgsInProto; 4981 4982 bool IsError = false; 4983 4984 // Initialize the implicit object parameter. 4985 IsError |= PerformObjectArgumentInitialization(Object, Method); 4986 TheCall->setArg(0, Object); 4987 4988 4989 // Check the argument types. 4990 for (unsigned i = 0; i != NumArgsToCheck; i++) { 4991 Expr *Arg; 4992 if (i < NumArgs) { 4993 Arg = Args[i]; 4994 4995 // Pass the argument. 4996 QualType ProtoArgType = Proto->getArgType(i); 4997 IsError |= PerformCopyInitialization(Arg, ProtoArgType, "passing"); 4998 } else { 4999 Arg = CXXDefaultArgExpr::Create(Context, Method->getParamDecl(i)); 5000 } 5001 5002 TheCall->setArg(i + 1, Arg); 5003 } 5004 5005 // If this is a variadic call, handle args passed through "...". 5006 if (Proto->isVariadic()) { 5007 // Promote the arguments (C99 6.5.2.2p7). 5008 for (unsigned i = NumArgsInProto; i != NumArgs; i++) { 5009 Expr *Arg = Args[i]; 5010 IsError |= DefaultVariadicArgumentPromotion(Arg, VariadicMethod); 5011 TheCall->setArg(i + 1, Arg); 5012 } 5013 } 5014 5015 if (IsError) return true; 5016 5017 if (CheckFunctionCall(Method, TheCall.get())) 5018 return true; 5019 5020 return MaybeBindToTemporary(TheCall.release()).release(); 5021} 5022 5023/// BuildOverloadedArrowExpr - Build a call to an overloaded @c operator-> 5024/// (if one exists), where @c Base is an expression of class type and 5025/// @c Member is the name of the member we're trying to find. 5026Sema::OwningExprResult 5027Sema::BuildOverloadedArrowExpr(Scope *S, ExprArg BaseIn, SourceLocation OpLoc) { 5028 Expr *Base = static_cast<Expr *>(BaseIn.get()); 5029 assert(Base->getType()->isRecordType() && "left-hand side must have class type"); 5030 5031 // C++ [over.ref]p1: 5032 // 5033 // [...] An expression x->m is interpreted as (x.operator->())->m 5034 // for a class object x of type T if T::operator->() exists and if 5035 // the operator is selected as the best match function by the 5036 // overload resolution mechanism (13.3). 5037 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Arrow); 5038 OverloadCandidateSet CandidateSet; 5039 const RecordType *BaseRecord = Base->getType()->getAs<RecordType>(); 5040 5041 LookupResult R = LookupQualifiedName(BaseRecord->getDecl(), OpName, 5042 LookupOrdinaryName); 5043 5044 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 5045 Oper != OperEnd; ++Oper) 5046 AddMethodCandidate(cast<CXXMethodDecl>(*Oper), Base, 0, 0, CandidateSet, 5047 /*SuppressUserConversions=*/false); 5048 5049 // Perform overload resolution. 5050 OverloadCandidateSet::iterator Best; 5051 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 5052 case OR_Success: 5053 // Overload resolution succeeded; we'll build the call below. 5054 break; 5055 5056 case OR_No_Viable_Function: 5057 if (CandidateSet.empty()) 5058 Diag(OpLoc, diag::err_typecheck_member_reference_arrow) 5059 << Base->getType() << Base->getSourceRange(); 5060 else 5061 Diag(OpLoc, diag::err_ovl_no_viable_oper) 5062 << "operator->" << Base->getSourceRange(); 5063 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 5064 return ExprError(); 5065 5066 case OR_Ambiguous: 5067 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 5068 << "->" << Base->getSourceRange(); 5069 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 5070 return ExprError(); 5071 5072 case OR_Deleted: 5073 Diag(OpLoc, diag::err_ovl_deleted_oper) 5074 << Best->Function->isDeleted() 5075 << "->" << Base->getSourceRange(); 5076 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 5077 return ExprError(); 5078 } 5079 5080 // Convert the object parameter. 5081 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 5082 if (PerformObjectArgumentInitialization(Base, Method)) 5083 return ExprError(); 5084 5085 // No concerns about early exits now. 5086 BaseIn.release(); 5087 5088 // Build the operator call. 5089 Expr *FnExpr = new (Context) DeclRefExpr(Method, Method->getType(), 5090 SourceLocation()); 5091 UsualUnaryConversions(FnExpr); 5092 Base = new (Context) CXXOperatorCallExpr(Context, OO_Arrow, FnExpr, &Base, 1, 5093 Method->getResultType().getNonReferenceType(), 5094 Method->getLocation()); 5095 return Owned(Base); 5096} 5097 5098/// FixOverloadedFunctionReference - E is an expression that refers to 5099/// a C++ overloaded function (possibly with some parentheses and 5100/// perhaps a '&' around it). We have resolved the overloaded function 5101/// to the function declaration Fn, so patch up the expression E to 5102/// refer (possibly indirectly) to Fn. 5103void Sema::FixOverloadedFunctionReference(Expr *E, FunctionDecl *Fn) { 5104 if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) { 5105 FixOverloadedFunctionReference(PE->getSubExpr(), Fn); 5106 E->setType(PE->getSubExpr()->getType()); 5107 } else if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(E)) { 5108 assert(UnOp->getOpcode() == UnaryOperator::AddrOf && 5109 "Can only take the address of an overloaded function"); 5110 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 5111 if (Method->isStatic()) { 5112 // Do nothing: static member functions aren't any different 5113 // from non-member functions. 5114 } else if (QualifiedDeclRefExpr *DRE 5115 = dyn_cast<QualifiedDeclRefExpr>(UnOp->getSubExpr())) { 5116 // We have taken the address of a pointer to member 5117 // function. Perform the computation here so that we get the 5118 // appropriate pointer to member type. 5119 DRE->setDecl(Fn); 5120 DRE->setType(Fn->getType()); 5121 QualType ClassType 5122 = Context.getTypeDeclType(cast<RecordDecl>(Method->getDeclContext())); 5123 E->setType(Context.getMemberPointerType(Fn->getType(), 5124 ClassType.getTypePtr())); 5125 return; 5126 } 5127 } 5128 FixOverloadedFunctionReference(UnOp->getSubExpr(), Fn); 5129 E->setType(Context.getPointerType(UnOp->getSubExpr()->getType())); 5130 } else if (DeclRefExpr *DR = dyn_cast<DeclRefExpr>(E)) { 5131 assert((isa<OverloadedFunctionDecl>(DR->getDecl()) || 5132 isa<FunctionTemplateDecl>(DR->getDecl())) && 5133 "Expected overloaded function or function template"); 5134 DR->setDecl(Fn); 5135 E->setType(Fn->getType()); 5136 } else if (MemberExpr *MemExpr = dyn_cast<MemberExpr>(E)) { 5137 MemExpr->setMemberDecl(Fn); 5138 E->setType(Fn->getType()); 5139 } else { 5140 assert(false && "Invalid reference to overloaded function"); 5141 } 5142} 5143 5144} // end namespace clang 5145