SemaOverload.cpp revision 249ceade4942a2a5d7888541c547abeda5bb85b4
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 return Expr->isNullPointerConstant(Context, 891 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull 892 : Expr::NPC_ValueDependentIsNull); 893} 894 895/// IsPointerConversion - Determines whether the conversion of the 896/// expression From, which has the (possibly adjusted) type FromType, 897/// can be converted to the type ToType via a pointer conversion (C++ 898/// 4.10). If so, returns true and places the converted type (that 899/// might differ from ToType in its cv-qualifiers at some level) into 900/// ConvertedType. 901/// 902/// This routine also supports conversions to and from block pointers 903/// and conversions with Objective-C's 'id', 'id<protocols...>', and 904/// pointers to interfaces. FIXME: Once we've determined the 905/// appropriate overloading rules for Objective-C, we may want to 906/// split the Objective-C checks into a different routine; however, 907/// GCC seems to consider all of these conversions to be pointer 908/// conversions, so for now they live here. IncompatibleObjC will be 909/// set if the conversion is an allowed Objective-C conversion that 910/// should result in a warning. 911bool Sema::IsPointerConversion(Expr *From, QualType FromType, QualType ToType, 912 bool InOverloadResolution, 913 QualType& ConvertedType, 914 bool &IncompatibleObjC) { 915 IncompatibleObjC = false; 916 if (isObjCPointerConversion(FromType, ToType, ConvertedType, IncompatibleObjC)) 917 return true; 918 919 // Conversion from a null pointer constant to any Objective-C pointer type. 920 if (ToType->isObjCObjectPointerType() && 921 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 922 ConvertedType = ToType; 923 return true; 924 } 925 926 // Blocks: Block pointers can be converted to void*. 927 if (FromType->isBlockPointerType() && ToType->isPointerType() && 928 ToType->getAs<PointerType>()->getPointeeType()->isVoidType()) { 929 ConvertedType = ToType; 930 return true; 931 } 932 // Blocks: A null pointer constant can be converted to a block 933 // pointer type. 934 if (ToType->isBlockPointerType() && 935 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 936 ConvertedType = ToType; 937 return true; 938 } 939 940 // If the left-hand-side is nullptr_t, the right side can be a null 941 // pointer constant. 942 if (ToType->isNullPtrType() && 943 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 944 ConvertedType = ToType; 945 return true; 946 } 947 948 const PointerType* ToTypePtr = ToType->getAs<PointerType>(); 949 if (!ToTypePtr) 950 return false; 951 952 // A null pointer constant can be converted to a pointer type (C++ 4.10p1). 953 if (isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 954 ConvertedType = ToType; 955 return true; 956 } 957 958 // Beyond this point, both types need to be pointers. 959 const PointerType *FromTypePtr = FromType->getAs<PointerType>(); 960 if (!FromTypePtr) 961 return false; 962 963 QualType FromPointeeType = FromTypePtr->getPointeeType(); 964 QualType ToPointeeType = ToTypePtr->getPointeeType(); 965 966 // An rvalue of type "pointer to cv T," where T is an object type, 967 // can be converted to an rvalue of type "pointer to cv void" (C++ 968 // 4.10p2). 969 if (FromPointeeType->isObjectType() && ToPointeeType->isVoidType()) { 970 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 971 ToPointeeType, 972 ToType, Context); 973 return true; 974 } 975 976 // When we're overloading in C, we allow a special kind of pointer 977 // conversion for compatible-but-not-identical pointee types. 978 if (!getLangOptions().CPlusPlus && 979 Context.typesAreCompatible(FromPointeeType, ToPointeeType)) { 980 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 981 ToPointeeType, 982 ToType, Context); 983 return true; 984 } 985 986 // C++ [conv.ptr]p3: 987 // 988 // An rvalue of type "pointer to cv D," where D is a class type, 989 // can be converted to an rvalue of type "pointer to cv B," where 990 // B is a base class (clause 10) of D. If B is an inaccessible 991 // (clause 11) or ambiguous (10.2) base class of D, a program that 992 // necessitates this conversion is ill-formed. The result of the 993 // conversion is a pointer to the base class sub-object of the 994 // derived class object. The null pointer value is converted to 995 // the null pointer value of the destination type. 996 // 997 // Note that we do not check for ambiguity or inaccessibility 998 // here. That is handled by CheckPointerConversion. 999 if (getLangOptions().CPlusPlus && 1000 FromPointeeType->isRecordType() && ToPointeeType->isRecordType() && 1001 IsDerivedFrom(FromPointeeType, ToPointeeType)) { 1002 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1003 ToPointeeType, 1004 ToType, Context); 1005 return true; 1006 } 1007 1008 return false; 1009} 1010 1011/// isObjCPointerConversion - Determines whether this is an 1012/// Objective-C pointer conversion. Subroutine of IsPointerConversion, 1013/// with the same arguments and return values. 1014bool Sema::isObjCPointerConversion(QualType FromType, QualType ToType, 1015 QualType& ConvertedType, 1016 bool &IncompatibleObjC) { 1017 if (!getLangOptions().ObjC1) 1018 return false; 1019 1020 // First, we handle all conversions on ObjC object pointer types. 1021 const ObjCObjectPointerType* ToObjCPtr = ToType->getAs<ObjCObjectPointerType>(); 1022 const ObjCObjectPointerType *FromObjCPtr = 1023 FromType->getAs<ObjCObjectPointerType>(); 1024 1025 if (ToObjCPtr && FromObjCPtr) { 1026 // Objective C++: We're able to convert between "id" or "Class" and a 1027 // pointer to any interface (in both directions). 1028 if (ToObjCPtr->isObjCBuiltinType() && FromObjCPtr->isObjCBuiltinType()) { 1029 ConvertedType = ToType; 1030 return true; 1031 } 1032 // Conversions with Objective-C's id<...>. 1033 if ((FromObjCPtr->isObjCQualifiedIdType() || 1034 ToObjCPtr->isObjCQualifiedIdType()) && 1035 Context.ObjCQualifiedIdTypesAreCompatible(ToType, FromType, 1036 /*compare=*/false)) { 1037 ConvertedType = ToType; 1038 return true; 1039 } 1040 // Objective C++: We're able to convert from a pointer to an 1041 // interface to a pointer to a different interface. 1042 if (Context.canAssignObjCInterfaces(ToObjCPtr, FromObjCPtr)) { 1043 ConvertedType = ToType; 1044 return true; 1045 } 1046 1047 if (Context.canAssignObjCInterfaces(FromObjCPtr, ToObjCPtr)) { 1048 // Okay: this is some kind of implicit downcast of Objective-C 1049 // interfaces, which is permitted. However, we're going to 1050 // complain about it. 1051 IncompatibleObjC = true; 1052 ConvertedType = FromType; 1053 return true; 1054 } 1055 } 1056 // Beyond this point, both types need to be C pointers or block pointers. 1057 QualType ToPointeeType; 1058 if (const PointerType *ToCPtr = ToType->getAs<PointerType>()) 1059 ToPointeeType = ToCPtr->getPointeeType(); 1060 else if (const BlockPointerType *ToBlockPtr = ToType->getAs<BlockPointerType>()) 1061 ToPointeeType = ToBlockPtr->getPointeeType(); 1062 else 1063 return false; 1064 1065 QualType FromPointeeType; 1066 if (const PointerType *FromCPtr = FromType->getAs<PointerType>()) 1067 FromPointeeType = FromCPtr->getPointeeType(); 1068 else if (const BlockPointerType *FromBlockPtr = FromType->getAs<BlockPointerType>()) 1069 FromPointeeType = FromBlockPtr->getPointeeType(); 1070 else 1071 return false; 1072 1073 // If we have pointers to pointers, recursively check whether this 1074 // is an Objective-C conversion. 1075 if (FromPointeeType->isPointerType() && ToPointeeType->isPointerType() && 1076 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, 1077 IncompatibleObjC)) { 1078 // We always complain about this conversion. 1079 IncompatibleObjC = true; 1080 ConvertedType = ToType; 1081 return true; 1082 } 1083 // If we have pointers to functions or blocks, check whether the only 1084 // differences in the argument and result types are in Objective-C 1085 // pointer conversions. If so, we permit the conversion (but 1086 // complain about it). 1087 const FunctionProtoType *FromFunctionType 1088 = FromPointeeType->getAs<FunctionProtoType>(); 1089 const FunctionProtoType *ToFunctionType 1090 = ToPointeeType->getAs<FunctionProtoType>(); 1091 if (FromFunctionType && ToFunctionType) { 1092 // If the function types are exactly the same, this isn't an 1093 // Objective-C pointer conversion. 1094 if (Context.getCanonicalType(FromPointeeType) 1095 == Context.getCanonicalType(ToPointeeType)) 1096 return false; 1097 1098 // Perform the quick checks that will tell us whether these 1099 // function types are obviously different. 1100 if (FromFunctionType->getNumArgs() != ToFunctionType->getNumArgs() || 1101 FromFunctionType->isVariadic() != ToFunctionType->isVariadic() || 1102 FromFunctionType->getTypeQuals() != ToFunctionType->getTypeQuals()) 1103 return false; 1104 1105 bool HasObjCConversion = false; 1106 if (Context.getCanonicalType(FromFunctionType->getResultType()) 1107 == Context.getCanonicalType(ToFunctionType->getResultType())) { 1108 // Okay, the types match exactly. Nothing to do. 1109 } else if (isObjCPointerConversion(FromFunctionType->getResultType(), 1110 ToFunctionType->getResultType(), 1111 ConvertedType, IncompatibleObjC)) { 1112 // Okay, we have an Objective-C pointer conversion. 1113 HasObjCConversion = true; 1114 } else { 1115 // Function types are too different. Abort. 1116 return false; 1117 } 1118 1119 // Check argument types. 1120 for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumArgs(); 1121 ArgIdx != NumArgs; ++ArgIdx) { 1122 QualType FromArgType = FromFunctionType->getArgType(ArgIdx); 1123 QualType ToArgType = ToFunctionType->getArgType(ArgIdx); 1124 if (Context.getCanonicalType(FromArgType) 1125 == Context.getCanonicalType(ToArgType)) { 1126 // Okay, the types match exactly. Nothing to do. 1127 } else if (isObjCPointerConversion(FromArgType, ToArgType, 1128 ConvertedType, IncompatibleObjC)) { 1129 // Okay, we have an Objective-C pointer conversion. 1130 HasObjCConversion = true; 1131 } else { 1132 // Argument types are too different. Abort. 1133 return false; 1134 } 1135 } 1136 1137 if (HasObjCConversion) { 1138 // We had an Objective-C conversion. Allow this pointer 1139 // conversion, but complain about it. 1140 ConvertedType = ToType; 1141 IncompatibleObjC = true; 1142 return true; 1143 } 1144 } 1145 1146 return false; 1147} 1148 1149/// CheckPointerConversion - Check the pointer conversion from the 1150/// expression From to the type ToType. This routine checks for 1151/// ambiguous or inaccessible derived-to-base pointer 1152/// conversions for which IsPointerConversion has already returned 1153/// true. It returns true and produces a diagnostic if there was an 1154/// error, or returns false otherwise. 1155bool Sema::CheckPointerConversion(Expr *From, QualType ToType, 1156 CastExpr::CastKind &Kind) { 1157 QualType FromType = From->getType(); 1158 1159 if (const PointerType *FromPtrType = FromType->getAs<PointerType>()) 1160 if (const PointerType *ToPtrType = ToType->getAs<PointerType>()) { 1161 QualType FromPointeeType = FromPtrType->getPointeeType(), 1162 ToPointeeType = ToPtrType->getPointeeType(); 1163 1164 if (FromPointeeType->isRecordType() && 1165 ToPointeeType->isRecordType()) { 1166 // We must have a derived-to-base conversion. Check an 1167 // ambiguous or inaccessible conversion. 1168 if (CheckDerivedToBaseConversion(FromPointeeType, ToPointeeType, 1169 From->getExprLoc(), 1170 From->getSourceRange())) 1171 return true; 1172 1173 // The conversion was successful. 1174 Kind = CastExpr::CK_DerivedToBase; 1175 } 1176 } 1177 if (const ObjCObjectPointerType *FromPtrType = 1178 FromType->getAs<ObjCObjectPointerType>()) 1179 if (const ObjCObjectPointerType *ToPtrType = 1180 ToType->getAs<ObjCObjectPointerType>()) { 1181 // Objective-C++ conversions are always okay. 1182 // FIXME: We should have a different class of conversions for the 1183 // Objective-C++ implicit conversions. 1184 if (FromPtrType->isObjCBuiltinType() || ToPtrType->isObjCBuiltinType()) 1185 return false; 1186 1187 } 1188 return false; 1189} 1190 1191/// IsMemberPointerConversion - Determines whether the conversion of the 1192/// expression From, which has the (possibly adjusted) type FromType, can be 1193/// converted to the type ToType via a member pointer conversion (C++ 4.11). 1194/// If so, returns true and places the converted type (that might differ from 1195/// ToType in its cv-qualifiers at some level) into ConvertedType. 1196bool Sema::IsMemberPointerConversion(Expr *From, QualType FromType, 1197 QualType ToType, 1198 bool InOverloadResolution, 1199 QualType &ConvertedType) { 1200 const MemberPointerType *ToTypePtr = ToType->getAs<MemberPointerType>(); 1201 if (!ToTypePtr) 1202 return false; 1203 1204 // A null pointer constant can be converted to a member pointer (C++ 4.11p1) 1205 if (From->isNullPointerConstant(Context, 1206 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull 1207 : Expr::NPC_ValueDependentIsNull)) { 1208 ConvertedType = ToType; 1209 return true; 1210 } 1211 1212 // Otherwise, both types have to be member pointers. 1213 const MemberPointerType *FromTypePtr = FromType->getAs<MemberPointerType>(); 1214 if (!FromTypePtr) 1215 return false; 1216 1217 // A pointer to member of B can be converted to a pointer to member of D, 1218 // where D is derived from B (C++ 4.11p2). 1219 QualType FromClass(FromTypePtr->getClass(), 0); 1220 QualType ToClass(ToTypePtr->getClass(), 0); 1221 // FIXME: What happens when these are dependent? Is this function even called? 1222 1223 if (IsDerivedFrom(ToClass, FromClass)) { 1224 ConvertedType = Context.getMemberPointerType(FromTypePtr->getPointeeType(), 1225 ToClass.getTypePtr()); 1226 return true; 1227 } 1228 1229 return false; 1230} 1231 1232/// CheckMemberPointerConversion - Check the member pointer conversion from the 1233/// expression From to the type ToType. This routine checks for ambiguous or 1234/// virtual (FIXME: or inaccessible) base-to-derived member pointer conversions 1235/// for which IsMemberPointerConversion has already returned true. It returns 1236/// true and produces a diagnostic if there was an error, or returns false 1237/// otherwise. 1238bool Sema::CheckMemberPointerConversion(Expr *From, QualType ToType, 1239 CastExpr::CastKind &Kind) { 1240 QualType FromType = From->getType(); 1241 const MemberPointerType *FromPtrType = FromType->getAs<MemberPointerType>(); 1242 if (!FromPtrType) { 1243 // This must be a null pointer to member pointer conversion 1244 assert(From->isNullPointerConstant(Context, 1245 Expr::NPC_ValueDependentIsNull) && 1246 "Expr must be null pointer constant!"); 1247 Kind = CastExpr::CK_NullToMemberPointer; 1248 return false; 1249 } 1250 1251 const MemberPointerType *ToPtrType = ToType->getAs<MemberPointerType>(); 1252 assert(ToPtrType && "No member pointer cast has a target type " 1253 "that is not a member pointer."); 1254 1255 QualType FromClass = QualType(FromPtrType->getClass(), 0); 1256 QualType ToClass = QualType(ToPtrType->getClass(), 0); 1257 1258 // FIXME: What about dependent types? 1259 assert(FromClass->isRecordType() && "Pointer into non-class."); 1260 assert(ToClass->isRecordType() && "Pointer into non-class."); 1261 1262 BasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/false, 1263 /*DetectVirtual=*/true); 1264 bool DerivationOkay = IsDerivedFrom(ToClass, FromClass, Paths); 1265 assert(DerivationOkay && 1266 "Should not have been called if derivation isn't OK."); 1267 (void)DerivationOkay; 1268 1269 if (Paths.isAmbiguous(Context.getCanonicalType(FromClass). 1270 getUnqualifiedType())) { 1271 // Derivation is ambiguous. Redo the check to find the exact paths. 1272 Paths.clear(); 1273 Paths.setRecordingPaths(true); 1274 bool StillOkay = IsDerivedFrom(ToClass, FromClass, Paths); 1275 assert(StillOkay && "Derivation changed due to quantum fluctuation."); 1276 (void)StillOkay; 1277 1278 std::string PathDisplayStr = getAmbiguousPathsDisplayString(Paths); 1279 Diag(From->getExprLoc(), diag::err_ambiguous_memptr_conv) 1280 << 0 << FromClass << ToClass << PathDisplayStr << From->getSourceRange(); 1281 return true; 1282 } 1283 1284 if (const RecordType *VBase = Paths.getDetectedVirtual()) { 1285 Diag(From->getExprLoc(), diag::err_memptr_conv_via_virtual) 1286 << FromClass << ToClass << QualType(VBase, 0) 1287 << From->getSourceRange(); 1288 return true; 1289 } 1290 1291 // Must be a base to derived member conversion. 1292 Kind = CastExpr::CK_BaseToDerivedMemberPointer; 1293 return false; 1294} 1295 1296/// IsQualificationConversion - Determines whether the conversion from 1297/// an rvalue of type FromType to ToType is a qualification conversion 1298/// (C++ 4.4). 1299bool 1300Sema::IsQualificationConversion(QualType FromType, QualType ToType) { 1301 FromType = Context.getCanonicalType(FromType); 1302 ToType = Context.getCanonicalType(ToType); 1303 1304 // If FromType and ToType are the same type, this is not a 1305 // qualification conversion. 1306 if (FromType == ToType) 1307 return false; 1308 1309 // (C++ 4.4p4): 1310 // A conversion can add cv-qualifiers at levels other than the first 1311 // in multi-level pointers, subject to the following rules: [...] 1312 bool PreviousToQualsIncludeConst = true; 1313 bool UnwrappedAnyPointer = false; 1314 while (UnwrapSimilarPointerTypes(FromType, ToType)) { 1315 // Within each iteration of the loop, we check the qualifiers to 1316 // determine if this still looks like a qualification 1317 // conversion. Then, if all is well, we unwrap one more level of 1318 // pointers or pointers-to-members and do it all again 1319 // until there are no more pointers or pointers-to-members left to 1320 // unwrap. 1321 UnwrappedAnyPointer = true; 1322 1323 // -- for every j > 0, if const is in cv 1,j then const is in cv 1324 // 2,j, and similarly for volatile. 1325 if (!ToType.isAtLeastAsQualifiedAs(FromType)) 1326 return false; 1327 1328 // -- if the cv 1,j and cv 2,j are different, then const is in 1329 // every cv for 0 < k < j. 1330 if (FromType.getCVRQualifiers() != ToType.getCVRQualifiers() 1331 && !PreviousToQualsIncludeConst) 1332 return false; 1333 1334 // Keep track of whether all prior cv-qualifiers in the "to" type 1335 // include const. 1336 PreviousToQualsIncludeConst 1337 = PreviousToQualsIncludeConst && ToType.isConstQualified(); 1338 } 1339 1340 // We are left with FromType and ToType being the pointee types 1341 // after unwrapping the original FromType and ToType the same number 1342 // of types. If we unwrapped any pointers, and if FromType and 1343 // ToType have the same unqualified type (since we checked 1344 // qualifiers above), then this is a qualification conversion. 1345 return UnwrappedAnyPointer && 1346 FromType.getUnqualifiedType() == ToType.getUnqualifiedType(); 1347} 1348 1349/// \brief Given a function template or function, extract the function template 1350/// declaration (if any) and the underlying function declaration. 1351template<typename T> 1352static void GetFunctionAndTemplate(AnyFunctionDecl Orig, T *&Function, 1353 FunctionTemplateDecl *&FunctionTemplate) { 1354 FunctionTemplate = dyn_cast<FunctionTemplateDecl>(Orig); 1355 if (FunctionTemplate) 1356 Function = cast<T>(FunctionTemplate->getTemplatedDecl()); 1357 else 1358 Function = cast<T>(Orig); 1359} 1360 1361/// Determines whether there is a user-defined conversion sequence 1362/// (C++ [over.ics.user]) that converts expression From to the type 1363/// ToType. If such a conversion exists, User will contain the 1364/// user-defined conversion sequence that performs such a conversion 1365/// and this routine will return true. Otherwise, this routine returns 1366/// false and User is unspecified. 1367/// 1368/// \param AllowConversionFunctions true if the conversion should 1369/// consider conversion functions at all. If false, only constructors 1370/// will be considered. 1371/// 1372/// \param AllowExplicit true if the conversion should consider C++0x 1373/// "explicit" conversion functions as well as non-explicit conversion 1374/// functions (C++0x [class.conv.fct]p2). 1375/// 1376/// \param ForceRValue true if the expression should be treated as an rvalue 1377/// for overload resolution. 1378/// \param UserCast true if looking for user defined conversion for a static 1379/// cast. 1380Sema::OverloadingResult Sema::IsUserDefinedConversion( 1381 Expr *From, QualType ToType, 1382 UserDefinedConversionSequence& User, 1383 OverloadCandidateSet& CandidateSet, 1384 bool AllowConversionFunctions, 1385 bool AllowExplicit, bool ForceRValue, 1386 bool UserCast) { 1387 if (const RecordType *ToRecordType = ToType->getAs<RecordType>()) { 1388 if (CXXRecordDecl *ToRecordDecl 1389 = dyn_cast<CXXRecordDecl>(ToRecordType->getDecl())) { 1390 // C++ [over.match.ctor]p1: 1391 // When objects of class type are direct-initialized (8.5), or 1392 // copy-initialized from an expression of the same or a 1393 // derived class type (8.5), overload resolution selects the 1394 // constructor. [...] For copy-initialization, the candidate 1395 // functions are all the converting constructors (12.3.1) of 1396 // that class. The argument list is the expression-list within 1397 // the parentheses of the initializer. 1398 DeclarationName ConstructorName 1399 = Context.DeclarationNames.getCXXConstructorName( 1400 Context.getCanonicalType(ToType).getUnqualifiedType()); 1401 DeclContext::lookup_iterator Con, ConEnd; 1402 for (llvm::tie(Con, ConEnd) 1403 = ToRecordDecl->lookup(ConstructorName); 1404 Con != ConEnd; ++Con) { 1405 // Find the constructor (which may be a template). 1406 CXXConstructorDecl *Constructor = 0; 1407 FunctionTemplateDecl *ConstructorTmpl 1408 = dyn_cast<FunctionTemplateDecl>(*Con); 1409 if (ConstructorTmpl) 1410 Constructor 1411 = cast<CXXConstructorDecl>(ConstructorTmpl->getTemplatedDecl()); 1412 else 1413 Constructor = cast<CXXConstructorDecl>(*Con); 1414 1415 if (!Constructor->isInvalidDecl() && 1416 Constructor->isConvertingConstructor(AllowExplicit)) { 1417 if (ConstructorTmpl) 1418 AddTemplateOverloadCandidate(ConstructorTmpl, false, 0, 0, &From, 1419 1, CandidateSet, 1420 /*SuppressUserConversions=*/!UserCast, 1421 ForceRValue); 1422 else 1423 // Allow one user-defined conversion when user specifies a 1424 // From->ToType conversion via an static cast (c-style, etc). 1425 AddOverloadCandidate(Constructor, &From, 1, CandidateSet, 1426 /*SuppressUserConversions=*/!UserCast, 1427 ForceRValue); 1428 } 1429 } 1430 } 1431 } 1432 1433 if (!AllowConversionFunctions) { 1434 // Don't allow any conversion functions to enter the overload set. 1435 } else if (RequireCompleteType(From->getLocStart(), From->getType(), 1436 PDiag(0) 1437 << From->getSourceRange())) { 1438 // No conversion functions from incomplete types. 1439 } else if (const RecordType *FromRecordType 1440 = From->getType()->getAs<RecordType>()) { 1441 if (CXXRecordDecl *FromRecordDecl 1442 = dyn_cast<CXXRecordDecl>(FromRecordType->getDecl())) { 1443 // Add all of the conversion functions as candidates. 1444 OverloadedFunctionDecl *Conversions 1445 = FromRecordDecl->getVisibleConversionFunctions(); 1446 for (OverloadedFunctionDecl::function_iterator Func 1447 = Conversions->function_begin(); 1448 Func != Conversions->function_end(); ++Func) { 1449 CXXConversionDecl *Conv; 1450 FunctionTemplateDecl *ConvTemplate; 1451 GetFunctionAndTemplate(*Func, Conv, ConvTemplate); 1452 if (ConvTemplate) 1453 Conv = dyn_cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 1454 else 1455 Conv = dyn_cast<CXXConversionDecl>(*Func); 1456 1457 if (AllowExplicit || !Conv->isExplicit()) { 1458 if (ConvTemplate) 1459 AddTemplateConversionCandidate(ConvTemplate, From, ToType, 1460 CandidateSet); 1461 else 1462 AddConversionCandidate(Conv, From, ToType, CandidateSet); 1463 } 1464 } 1465 } 1466 } 1467 1468 OverloadCandidateSet::iterator Best; 1469 switch (BestViableFunction(CandidateSet, From->getLocStart(), Best)) { 1470 case OR_Success: 1471 // Record the standard conversion we used and the conversion function. 1472 if (CXXConstructorDecl *Constructor 1473 = dyn_cast<CXXConstructorDecl>(Best->Function)) { 1474 // C++ [over.ics.user]p1: 1475 // If the user-defined conversion is specified by a 1476 // constructor (12.3.1), the initial standard conversion 1477 // sequence converts the source type to the type required by 1478 // the argument of the constructor. 1479 // 1480 // FIXME: What about ellipsis conversions? 1481 QualType ThisType = Constructor->getThisType(Context); 1482 User.Before = Best->Conversions[0].Standard; 1483 User.ConversionFunction = Constructor; 1484 User.After.setAsIdentityConversion(); 1485 User.After.FromTypePtr 1486 = ThisType->getAs<PointerType>()->getPointeeType().getAsOpaquePtr(); 1487 User.After.ToTypePtr = ToType.getAsOpaquePtr(); 1488 return OR_Success; 1489 } else if (CXXConversionDecl *Conversion 1490 = dyn_cast<CXXConversionDecl>(Best->Function)) { 1491 // C++ [over.ics.user]p1: 1492 // 1493 // [...] If the user-defined conversion is specified by a 1494 // conversion function (12.3.2), the initial standard 1495 // conversion sequence converts the source type to the 1496 // implicit object parameter of the conversion function. 1497 User.Before = Best->Conversions[0].Standard; 1498 User.ConversionFunction = Conversion; 1499 1500 // C++ [over.ics.user]p2: 1501 // The second standard conversion sequence converts the 1502 // result of the user-defined conversion to the target type 1503 // for the sequence. Since an implicit conversion sequence 1504 // is an initialization, the special rules for 1505 // initialization by user-defined conversion apply when 1506 // selecting the best user-defined conversion for a 1507 // user-defined conversion sequence (see 13.3.3 and 1508 // 13.3.3.1). 1509 User.After = Best->FinalConversion; 1510 return OR_Success; 1511 } else { 1512 assert(false && "Not a constructor or conversion function?"); 1513 return OR_No_Viable_Function; 1514 } 1515 1516 case OR_No_Viable_Function: 1517 return OR_No_Viable_Function; 1518 case OR_Deleted: 1519 // No conversion here! We're done. 1520 return OR_Deleted; 1521 1522 case OR_Ambiguous: 1523 return OR_Ambiguous; 1524 } 1525 1526 return OR_No_Viable_Function; 1527} 1528 1529bool 1530Sema::DiagnoseAmbiguousUserDefinedConversion(Expr *From, QualType ToType) { 1531 ImplicitConversionSequence ICS; 1532 OverloadCandidateSet CandidateSet; 1533 OverloadingResult OvResult = 1534 IsUserDefinedConversion(From, ToType, ICS.UserDefined, 1535 CandidateSet, true, false, false); 1536 if (OvResult != OR_Ambiguous) 1537 return false; 1538 Diag(From->getSourceRange().getBegin(), 1539 diag::err_typecheck_ambiguous_condition) 1540 << From->getType() << ToType << From->getSourceRange(); 1541 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 1542 return true; 1543} 1544 1545/// CompareImplicitConversionSequences - Compare two implicit 1546/// conversion sequences to determine whether one is better than the 1547/// other or if they are indistinguishable (C++ 13.3.3.2). 1548ImplicitConversionSequence::CompareKind 1549Sema::CompareImplicitConversionSequences(const ImplicitConversionSequence& ICS1, 1550 const ImplicitConversionSequence& ICS2) 1551{ 1552 // (C++ 13.3.3.2p2): When comparing the basic forms of implicit 1553 // conversion sequences (as defined in 13.3.3.1) 1554 // -- a standard conversion sequence (13.3.3.1.1) is a better 1555 // conversion sequence than a user-defined conversion sequence or 1556 // an ellipsis conversion sequence, and 1557 // -- a user-defined conversion sequence (13.3.3.1.2) is a better 1558 // conversion sequence than an ellipsis conversion sequence 1559 // (13.3.3.1.3). 1560 // 1561 if (ICS1.ConversionKind < ICS2.ConversionKind) 1562 return ImplicitConversionSequence::Better; 1563 else if (ICS2.ConversionKind < ICS1.ConversionKind) 1564 return ImplicitConversionSequence::Worse; 1565 1566 // Two implicit conversion sequences of the same form are 1567 // indistinguishable conversion sequences unless one of the 1568 // following rules apply: (C++ 13.3.3.2p3): 1569 if (ICS1.ConversionKind == ImplicitConversionSequence::StandardConversion) 1570 return CompareStandardConversionSequences(ICS1.Standard, ICS2.Standard); 1571 else if (ICS1.ConversionKind == 1572 ImplicitConversionSequence::UserDefinedConversion) { 1573 // User-defined conversion sequence U1 is a better conversion 1574 // sequence than another user-defined conversion sequence U2 if 1575 // they contain the same user-defined conversion function or 1576 // constructor and if the second standard conversion sequence of 1577 // U1 is better than the second standard conversion sequence of 1578 // U2 (C++ 13.3.3.2p3). 1579 if (ICS1.UserDefined.ConversionFunction == 1580 ICS2.UserDefined.ConversionFunction) 1581 return CompareStandardConversionSequences(ICS1.UserDefined.After, 1582 ICS2.UserDefined.After); 1583 } 1584 1585 return ImplicitConversionSequence::Indistinguishable; 1586} 1587 1588/// CompareStandardConversionSequences - Compare two standard 1589/// conversion sequences to determine whether one is better than the 1590/// other or if they are indistinguishable (C++ 13.3.3.2p3). 1591ImplicitConversionSequence::CompareKind 1592Sema::CompareStandardConversionSequences(const StandardConversionSequence& SCS1, 1593 const StandardConversionSequence& SCS2) 1594{ 1595 // Standard conversion sequence S1 is a better conversion sequence 1596 // than standard conversion sequence S2 if (C++ 13.3.3.2p3): 1597 1598 // -- S1 is a proper subsequence of S2 (comparing the conversion 1599 // sequences in the canonical form defined by 13.3.3.1.1, 1600 // excluding any Lvalue Transformation; the identity conversion 1601 // sequence is considered to be a subsequence of any 1602 // non-identity conversion sequence) or, if not that, 1603 if (SCS1.Second == SCS2.Second && SCS1.Third == SCS2.Third) 1604 // Neither is a proper subsequence of the other. Do nothing. 1605 ; 1606 else if ((SCS1.Second == ICK_Identity && SCS1.Third == SCS2.Third) || 1607 (SCS1.Third == ICK_Identity && SCS1.Second == SCS2.Second) || 1608 (SCS1.Second == ICK_Identity && 1609 SCS1.Third == ICK_Identity)) 1610 // SCS1 is a proper subsequence of SCS2. 1611 return ImplicitConversionSequence::Better; 1612 else if ((SCS2.Second == ICK_Identity && SCS2.Third == SCS1.Third) || 1613 (SCS2.Third == ICK_Identity && SCS2.Second == SCS1.Second) || 1614 (SCS2.Second == ICK_Identity && 1615 SCS2.Third == ICK_Identity)) 1616 // SCS2 is a proper subsequence of SCS1. 1617 return ImplicitConversionSequence::Worse; 1618 1619 // -- the rank of S1 is better than the rank of S2 (by the rules 1620 // defined below), or, if not that, 1621 ImplicitConversionRank Rank1 = SCS1.getRank(); 1622 ImplicitConversionRank Rank2 = SCS2.getRank(); 1623 if (Rank1 < Rank2) 1624 return ImplicitConversionSequence::Better; 1625 else if (Rank2 < Rank1) 1626 return ImplicitConversionSequence::Worse; 1627 1628 // (C++ 13.3.3.2p4): Two conversion sequences with the same rank 1629 // are indistinguishable unless one of the following rules 1630 // applies: 1631 1632 // A conversion that is not a conversion of a pointer, or 1633 // pointer to member, to bool is better than another conversion 1634 // that is such a conversion. 1635 if (SCS1.isPointerConversionToBool() != SCS2.isPointerConversionToBool()) 1636 return SCS2.isPointerConversionToBool() 1637 ? ImplicitConversionSequence::Better 1638 : ImplicitConversionSequence::Worse; 1639 1640 // C++ [over.ics.rank]p4b2: 1641 // 1642 // If class B is derived directly or indirectly from class A, 1643 // conversion of B* to A* is better than conversion of B* to 1644 // void*, and conversion of A* to void* is better than conversion 1645 // of B* to void*. 1646 bool SCS1ConvertsToVoid 1647 = SCS1.isPointerConversionToVoidPointer(Context); 1648 bool SCS2ConvertsToVoid 1649 = SCS2.isPointerConversionToVoidPointer(Context); 1650 if (SCS1ConvertsToVoid != SCS2ConvertsToVoid) { 1651 // Exactly one of the conversion sequences is a conversion to 1652 // a void pointer; it's the worse conversion. 1653 return SCS2ConvertsToVoid ? ImplicitConversionSequence::Better 1654 : ImplicitConversionSequence::Worse; 1655 } else if (!SCS1ConvertsToVoid && !SCS2ConvertsToVoid) { 1656 // Neither conversion sequence converts to a void pointer; compare 1657 // their derived-to-base conversions. 1658 if (ImplicitConversionSequence::CompareKind DerivedCK 1659 = CompareDerivedToBaseConversions(SCS1, SCS2)) 1660 return DerivedCK; 1661 } else if (SCS1ConvertsToVoid && SCS2ConvertsToVoid) { 1662 // Both conversion sequences are conversions to void 1663 // pointers. Compare the source types to determine if there's an 1664 // inheritance relationship in their sources. 1665 QualType FromType1 = QualType::getFromOpaquePtr(SCS1.FromTypePtr); 1666 QualType FromType2 = QualType::getFromOpaquePtr(SCS2.FromTypePtr); 1667 1668 // Adjust the types we're converting from via the array-to-pointer 1669 // conversion, if we need to. 1670 if (SCS1.First == ICK_Array_To_Pointer) 1671 FromType1 = Context.getArrayDecayedType(FromType1); 1672 if (SCS2.First == ICK_Array_To_Pointer) 1673 FromType2 = Context.getArrayDecayedType(FromType2); 1674 1675 QualType FromPointee1 1676 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1677 QualType FromPointee2 1678 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1679 1680 if (IsDerivedFrom(FromPointee2, FromPointee1)) 1681 return ImplicitConversionSequence::Better; 1682 else if (IsDerivedFrom(FromPointee1, FromPointee2)) 1683 return ImplicitConversionSequence::Worse; 1684 1685 // Objective-C++: If one interface is more specific than the 1686 // other, it is the better one. 1687 const ObjCInterfaceType* FromIface1 = FromPointee1->getAs<ObjCInterfaceType>(); 1688 const ObjCInterfaceType* FromIface2 = FromPointee2->getAs<ObjCInterfaceType>(); 1689 if (FromIface1 && FromIface1) { 1690 if (Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 1691 return ImplicitConversionSequence::Better; 1692 else if (Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 1693 return ImplicitConversionSequence::Worse; 1694 } 1695 } 1696 1697 // Compare based on qualification conversions (C++ 13.3.3.2p3, 1698 // bullet 3). 1699 if (ImplicitConversionSequence::CompareKind QualCK 1700 = CompareQualificationConversions(SCS1, SCS2)) 1701 return QualCK; 1702 1703 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding) { 1704 // C++0x [over.ics.rank]p3b4: 1705 // -- S1 and S2 are reference bindings (8.5.3) and neither refers to an 1706 // implicit object parameter of a non-static member function declared 1707 // without a ref-qualifier, and S1 binds an rvalue reference to an 1708 // rvalue and S2 binds an lvalue reference. 1709 // FIXME: We don't know if we're dealing with the implicit object parameter, 1710 // or if the member function in this case has a ref qualifier. 1711 // (Of course, we don't have ref qualifiers yet.) 1712 if (SCS1.RRefBinding != SCS2.RRefBinding) 1713 return SCS1.RRefBinding ? ImplicitConversionSequence::Better 1714 : ImplicitConversionSequence::Worse; 1715 1716 // C++ [over.ics.rank]p3b4: 1717 // -- S1 and S2 are reference bindings (8.5.3), and the types to 1718 // which the references refer are the same type except for 1719 // top-level cv-qualifiers, and the type to which the reference 1720 // initialized by S2 refers is more cv-qualified than the type 1721 // to which the reference initialized by S1 refers. 1722 QualType T1 = QualType::getFromOpaquePtr(SCS1.ToTypePtr); 1723 QualType T2 = QualType::getFromOpaquePtr(SCS2.ToTypePtr); 1724 T1 = Context.getCanonicalType(T1); 1725 T2 = Context.getCanonicalType(T2); 1726 if (T1.getUnqualifiedType() == T2.getUnqualifiedType()) { 1727 if (T2.isMoreQualifiedThan(T1)) 1728 return ImplicitConversionSequence::Better; 1729 else if (T1.isMoreQualifiedThan(T2)) 1730 return ImplicitConversionSequence::Worse; 1731 } 1732 } 1733 1734 return ImplicitConversionSequence::Indistinguishable; 1735} 1736 1737/// CompareQualificationConversions - Compares two standard conversion 1738/// sequences to determine whether they can be ranked based on their 1739/// qualification conversions (C++ 13.3.3.2p3 bullet 3). 1740ImplicitConversionSequence::CompareKind 1741Sema::CompareQualificationConversions(const StandardConversionSequence& SCS1, 1742 const StandardConversionSequence& SCS2) { 1743 // C++ 13.3.3.2p3: 1744 // -- S1 and S2 differ only in their qualification conversion and 1745 // yield similar types T1 and T2 (C++ 4.4), respectively, and the 1746 // cv-qualification signature of type T1 is a proper subset of 1747 // the cv-qualification signature of type T2, and S1 is not the 1748 // deprecated string literal array-to-pointer conversion (4.2). 1749 if (SCS1.First != SCS2.First || SCS1.Second != SCS2.Second || 1750 SCS1.Third != SCS2.Third || SCS1.Third != ICK_Qualification) 1751 return ImplicitConversionSequence::Indistinguishable; 1752 1753 // FIXME: the example in the standard doesn't use a qualification 1754 // conversion (!) 1755 QualType T1 = QualType::getFromOpaquePtr(SCS1.ToTypePtr); 1756 QualType T2 = QualType::getFromOpaquePtr(SCS2.ToTypePtr); 1757 T1 = Context.getCanonicalType(T1); 1758 T2 = Context.getCanonicalType(T2); 1759 1760 // If the types are the same, we won't learn anything by unwrapped 1761 // them. 1762 if (T1.getUnqualifiedType() == T2.getUnqualifiedType()) 1763 return ImplicitConversionSequence::Indistinguishable; 1764 1765 ImplicitConversionSequence::CompareKind Result 1766 = ImplicitConversionSequence::Indistinguishable; 1767 while (UnwrapSimilarPointerTypes(T1, T2)) { 1768 // Within each iteration of the loop, we check the qualifiers to 1769 // determine if this still looks like a qualification 1770 // conversion. Then, if all is well, we unwrap one more level of 1771 // pointers or pointers-to-members and do it all again 1772 // until there are no more pointers or pointers-to-members left 1773 // to unwrap. This essentially mimics what 1774 // IsQualificationConversion does, but here we're checking for a 1775 // strict subset of qualifiers. 1776 if (T1.getCVRQualifiers() == T2.getCVRQualifiers()) 1777 // The qualifiers are the same, so this doesn't tell us anything 1778 // about how the sequences rank. 1779 ; 1780 else if (T2.isMoreQualifiedThan(T1)) { 1781 // T1 has fewer qualifiers, so it could be the better sequence. 1782 if (Result == ImplicitConversionSequence::Worse) 1783 // Neither has qualifiers that are a subset of the other's 1784 // qualifiers. 1785 return ImplicitConversionSequence::Indistinguishable; 1786 1787 Result = ImplicitConversionSequence::Better; 1788 } else if (T1.isMoreQualifiedThan(T2)) { 1789 // T2 has fewer qualifiers, so it could be the better sequence. 1790 if (Result == ImplicitConversionSequence::Better) 1791 // Neither has qualifiers that are a subset of the other's 1792 // qualifiers. 1793 return ImplicitConversionSequence::Indistinguishable; 1794 1795 Result = ImplicitConversionSequence::Worse; 1796 } else { 1797 // Qualifiers are disjoint. 1798 return ImplicitConversionSequence::Indistinguishable; 1799 } 1800 1801 // If the types after this point are equivalent, we're done. 1802 if (T1.getUnqualifiedType() == T2.getUnqualifiedType()) 1803 break; 1804 } 1805 1806 // Check that the winning standard conversion sequence isn't using 1807 // the deprecated string literal array to pointer conversion. 1808 switch (Result) { 1809 case ImplicitConversionSequence::Better: 1810 if (SCS1.Deprecated) 1811 Result = ImplicitConversionSequence::Indistinguishable; 1812 break; 1813 1814 case ImplicitConversionSequence::Indistinguishable: 1815 break; 1816 1817 case ImplicitConversionSequence::Worse: 1818 if (SCS2.Deprecated) 1819 Result = ImplicitConversionSequence::Indistinguishable; 1820 break; 1821 } 1822 1823 return Result; 1824} 1825 1826/// CompareDerivedToBaseConversions - Compares two standard conversion 1827/// sequences to determine whether they can be ranked based on their 1828/// various kinds of derived-to-base conversions (C++ 1829/// [over.ics.rank]p4b3). As part of these checks, we also look at 1830/// conversions between Objective-C interface types. 1831ImplicitConversionSequence::CompareKind 1832Sema::CompareDerivedToBaseConversions(const StandardConversionSequence& SCS1, 1833 const StandardConversionSequence& SCS2) { 1834 QualType FromType1 = QualType::getFromOpaquePtr(SCS1.FromTypePtr); 1835 QualType ToType1 = QualType::getFromOpaquePtr(SCS1.ToTypePtr); 1836 QualType FromType2 = QualType::getFromOpaquePtr(SCS2.FromTypePtr); 1837 QualType ToType2 = QualType::getFromOpaquePtr(SCS2.ToTypePtr); 1838 1839 // Adjust the types we're converting from via the array-to-pointer 1840 // conversion, if we need to. 1841 if (SCS1.First == ICK_Array_To_Pointer) 1842 FromType1 = Context.getArrayDecayedType(FromType1); 1843 if (SCS2.First == ICK_Array_To_Pointer) 1844 FromType2 = Context.getArrayDecayedType(FromType2); 1845 1846 // Canonicalize all of the types. 1847 FromType1 = Context.getCanonicalType(FromType1); 1848 ToType1 = Context.getCanonicalType(ToType1); 1849 FromType2 = Context.getCanonicalType(FromType2); 1850 ToType2 = Context.getCanonicalType(ToType2); 1851 1852 // C++ [over.ics.rank]p4b3: 1853 // 1854 // If class B is derived directly or indirectly from class A and 1855 // class C is derived directly or indirectly from B, 1856 // 1857 // For Objective-C, we let A, B, and C also be Objective-C 1858 // interfaces. 1859 1860 // Compare based on pointer conversions. 1861 if (SCS1.Second == ICK_Pointer_Conversion && 1862 SCS2.Second == ICK_Pointer_Conversion && 1863 /*FIXME: Remove if Objective-C id conversions get their own rank*/ 1864 FromType1->isPointerType() && FromType2->isPointerType() && 1865 ToType1->isPointerType() && ToType2->isPointerType()) { 1866 QualType FromPointee1 1867 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1868 QualType ToPointee1 1869 = ToType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1870 QualType FromPointee2 1871 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1872 QualType ToPointee2 1873 = ToType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1874 1875 const ObjCInterfaceType* FromIface1 = FromPointee1->getAs<ObjCInterfaceType>(); 1876 const ObjCInterfaceType* FromIface2 = FromPointee2->getAs<ObjCInterfaceType>(); 1877 const ObjCInterfaceType* ToIface1 = ToPointee1->getAs<ObjCInterfaceType>(); 1878 const ObjCInterfaceType* ToIface2 = ToPointee2->getAs<ObjCInterfaceType>(); 1879 1880 // -- conversion of C* to B* is better than conversion of C* to A*, 1881 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 1882 if (IsDerivedFrom(ToPointee1, ToPointee2)) 1883 return ImplicitConversionSequence::Better; 1884 else if (IsDerivedFrom(ToPointee2, ToPointee1)) 1885 return ImplicitConversionSequence::Worse; 1886 1887 if (ToIface1 && ToIface2) { 1888 if (Context.canAssignObjCInterfaces(ToIface2, ToIface1)) 1889 return ImplicitConversionSequence::Better; 1890 else if (Context.canAssignObjCInterfaces(ToIface1, ToIface2)) 1891 return ImplicitConversionSequence::Worse; 1892 } 1893 } 1894 1895 // -- conversion of B* to A* is better than conversion of C* to A*, 1896 if (FromPointee1 != FromPointee2 && ToPointee1 == ToPointee2) { 1897 if (IsDerivedFrom(FromPointee2, FromPointee1)) 1898 return ImplicitConversionSequence::Better; 1899 else if (IsDerivedFrom(FromPointee1, FromPointee2)) 1900 return ImplicitConversionSequence::Worse; 1901 1902 if (FromIface1 && FromIface2) { 1903 if (Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 1904 return ImplicitConversionSequence::Better; 1905 else if (Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 1906 return ImplicitConversionSequence::Worse; 1907 } 1908 } 1909 } 1910 1911 // Compare based on reference bindings. 1912 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding && 1913 SCS1.Second == ICK_Derived_To_Base) { 1914 // -- binding of an expression of type C to a reference of type 1915 // B& is better than binding an expression of type C to a 1916 // reference of type A&, 1917 if (FromType1.getUnqualifiedType() == FromType2.getUnqualifiedType() && 1918 ToType1.getUnqualifiedType() != ToType2.getUnqualifiedType()) { 1919 if (IsDerivedFrom(ToType1, ToType2)) 1920 return ImplicitConversionSequence::Better; 1921 else if (IsDerivedFrom(ToType2, ToType1)) 1922 return ImplicitConversionSequence::Worse; 1923 } 1924 1925 // -- binding of an expression of type B to a reference of type 1926 // A& is better than binding an expression of type C to a 1927 // reference of type A&, 1928 if (FromType1.getUnqualifiedType() != FromType2.getUnqualifiedType() && 1929 ToType1.getUnqualifiedType() == ToType2.getUnqualifiedType()) { 1930 if (IsDerivedFrom(FromType2, FromType1)) 1931 return ImplicitConversionSequence::Better; 1932 else if (IsDerivedFrom(FromType1, FromType2)) 1933 return ImplicitConversionSequence::Worse; 1934 } 1935 } 1936 1937 1938 // FIXME: conversion of A::* to B::* is better than conversion of 1939 // A::* to C::*, 1940 1941 // FIXME: conversion of B::* to C::* is better than conversion of 1942 // A::* to C::*, and 1943 1944 if (SCS1.CopyConstructor && SCS2.CopyConstructor && 1945 SCS1.Second == ICK_Derived_To_Base) { 1946 // -- conversion of C to B is better than conversion of C to A, 1947 if (FromType1.getUnqualifiedType() == FromType2.getUnqualifiedType() && 1948 ToType1.getUnqualifiedType() != ToType2.getUnqualifiedType()) { 1949 if (IsDerivedFrom(ToType1, ToType2)) 1950 return ImplicitConversionSequence::Better; 1951 else if (IsDerivedFrom(ToType2, ToType1)) 1952 return ImplicitConversionSequence::Worse; 1953 } 1954 1955 // -- conversion of B to A is better than conversion of C to A. 1956 if (FromType1.getUnqualifiedType() != FromType2.getUnqualifiedType() && 1957 ToType1.getUnqualifiedType() == ToType2.getUnqualifiedType()) { 1958 if (IsDerivedFrom(FromType2, FromType1)) 1959 return ImplicitConversionSequence::Better; 1960 else if (IsDerivedFrom(FromType1, FromType2)) 1961 return ImplicitConversionSequence::Worse; 1962 } 1963 } 1964 1965 return ImplicitConversionSequence::Indistinguishable; 1966} 1967 1968/// TryCopyInitialization - Try to copy-initialize a value of type 1969/// ToType from the expression From. Return the implicit conversion 1970/// sequence required to pass this argument, which may be a bad 1971/// conversion sequence (meaning that the argument cannot be passed to 1972/// a parameter of this type). If @p SuppressUserConversions, then we 1973/// do not permit any user-defined conversion sequences. If @p ForceRValue, 1974/// then we treat @p From as an rvalue, even if it is an lvalue. 1975ImplicitConversionSequence 1976Sema::TryCopyInitialization(Expr *From, QualType ToType, 1977 bool SuppressUserConversions, bool ForceRValue, 1978 bool InOverloadResolution) { 1979 if (ToType->isReferenceType()) { 1980 ImplicitConversionSequence ICS; 1981 CheckReferenceInit(From, ToType, 1982 /*FIXME:*/From->getLocStart(), 1983 SuppressUserConversions, 1984 /*AllowExplicit=*/false, 1985 ForceRValue, 1986 &ICS); 1987 return ICS; 1988 } else { 1989 return TryImplicitConversion(From, ToType, 1990 SuppressUserConversions, 1991 /*AllowExplicit=*/false, 1992 ForceRValue, 1993 InOverloadResolution); 1994 } 1995} 1996 1997/// PerformCopyInitialization - Copy-initialize an object of type @p ToType with 1998/// the expression @p From. Returns true (and emits a diagnostic) if there was 1999/// an error, returns false if the initialization succeeded. Elidable should 2000/// be true when the copy may be elided (C++ 12.8p15). Overload resolution works 2001/// differently in C++0x for this case. 2002bool Sema::PerformCopyInitialization(Expr *&From, QualType ToType, 2003 const char* Flavor, bool Elidable) { 2004 if (!getLangOptions().CPlusPlus) { 2005 // In C, argument passing is the same as performing an assignment. 2006 QualType FromType = From->getType(); 2007 2008 AssignConvertType ConvTy = 2009 CheckSingleAssignmentConstraints(ToType, From); 2010 if (ConvTy != Compatible && 2011 CheckTransparentUnionArgumentConstraints(ToType, From) == Compatible) 2012 ConvTy = Compatible; 2013 2014 return DiagnoseAssignmentResult(ConvTy, From->getLocStart(), ToType, 2015 FromType, From, Flavor); 2016 } 2017 2018 if (ToType->isReferenceType()) 2019 return CheckReferenceInit(From, ToType, 2020 /*FIXME:*/From->getLocStart(), 2021 /*SuppressUserConversions=*/false, 2022 /*AllowExplicit=*/false, 2023 /*ForceRValue=*/false); 2024 2025 if (!PerformImplicitConversion(From, ToType, Flavor, 2026 /*AllowExplicit=*/false, Elidable)) 2027 return false; 2028 if (!DiagnoseAmbiguousUserDefinedConversion(From, ToType)) 2029 return Diag(From->getSourceRange().getBegin(), 2030 diag::err_typecheck_convert_incompatible) 2031 << ToType << From->getType() << Flavor << From->getSourceRange(); 2032 return true; 2033} 2034 2035/// TryObjectArgumentInitialization - Try to initialize the object 2036/// parameter of the given member function (@c Method) from the 2037/// expression @p From. 2038ImplicitConversionSequence 2039Sema::TryObjectArgumentInitialization(Expr *From, CXXMethodDecl *Method) { 2040 QualType ClassType = Context.getTypeDeclType(Method->getParent()); 2041 QualType ImplicitParamType 2042 = Context.getCVRQualifiedType(ClassType, Method->getTypeQualifiers()); 2043 2044 // Set up the conversion sequence as a "bad" conversion, to allow us 2045 // to exit early. 2046 ImplicitConversionSequence ICS; 2047 ICS.Standard.setAsIdentityConversion(); 2048 ICS.ConversionKind = ImplicitConversionSequence::BadConversion; 2049 2050 // We need to have an object of class type. 2051 QualType FromType = From->getType(); 2052 if (const PointerType *PT = FromType->getAs<PointerType>()) 2053 FromType = PT->getPointeeType(); 2054 2055 assert(FromType->isRecordType()); 2056 2057 // The implicit object parmeter is has the type "reference to cv X", 2058 // where X is the class of which the function is a member 2059 // (C++ [over.match.funcs]p4). However, when finding an implicit 2060 // conversion sequence for the argument, we are not allowed to 2061 // create temporaries or perform user-defined conversions 2062 // (C++ [over.match.funcs]p5). We perform a simplified version of 2063 // reference binding here, that allows class rvalues to bind to 2064 // non-constant references. 2065 2066 // First check the qualifiers. We don't care about lvalue-vs-rvalue 2067 // with the implicit object parameter (C++ [over.match.funcs]p5). 2068 QualType FromTypeCanon = Context.getCanonicalType(FromType); 2069 if (ImplicitParamType.getCVRQualifiers() != FromType.getCVRQualifiers() && 2070 !ImplicitParamType.isAtLeastAsQualifiedAs(FromType)) 2071 return ICS; 2072 2073 // Check that we have either the same type or a derived type. It 2074 // affects the conversion rank. 2075 QualType ClassTypeCanon = Context.getCanonicalType(ClassType); 2076 if (ClassTypeCanon == FromTypeCanon.getUnqualifiedType()) 2077 ICS.Standard.Second = ICK_Identity; 2078 else if (IsDerivedFrom(FromType, ClassType)) 2079 ICS.Standard.Second = ICK_Derived_To_Base; 2080 else 2081 return ICS; 2082 2083 // Success. Mark this as a reference binding. 2084 ICS.ConversionKind = ImplicitConversionSequence::StandardConversion; 2085 ICS.Standard.FromTypePtr = FromType.getAsOpaquePtr(); 2086 ICS.Standard.ToTypePtr = ImplicitParamType.getAsOpaquePtr(); 2087 ICS.Standard.ReferenceBinding = true; 2088 ICS.Standard.DirectBinding = true; 2089 ICS.Standard.RRefBinding = false; 2090 return ICS; 2091} 2092 2093/// PerformObjectArgumentInitialization - Perform initialization of 2094/// the implicit object parameter for the given Method with the given 2095/// expression. 2096bool 2097Sema::PerformObjectArgumentInitialization(Expr *&From, CXXMethodDecl *Method) { 2098 QualType FromRecordType, DestType; 2099 QualType ImplicitParamRecordType = 2100 Method->getThisType(Context)->getAs<PointerType>()->getPointeeType(); 2101 2102 if (const PointerType *PT = From->getType()->getAs<PointerType>()) { 2103 FromRecordType = PT->getPointeeType(); 2104 DestType = Method->getThisType(Context); 2105 } else { 2106 FromRecordType = From->getType(); 2107 DestType = ImplicitParamRecordType; 2108 } 2109 2110 ImplicitConversionSequence ICS 2111 = TryObjectArgumentInitialization(From, Method); 2112 if (ICS.ConversionKind == ImplicitConversionSequence::BadConversion) 2113 return Diag(From->getSourceRange().getBegin(), 2114 diag::err_implicit_object_parameter_init) 2115 << ImplicitParamRecordType << FromRecordType << From->getSourceRange(); 2116 2117 if (ICS.Standard.Second == ICK_Derived_To_Base && 2118 CheckDerivedToBaseConversion(FromRecordType, 2119 ImplicitParamRecordType, 2120 From->getSourceRange().getBegin(), 2121 From->getSourceRange())) 2122 return true; 2123 2124 ImpCastExprToType(From, DestType, CastExpr::CK_DerivedToBase, 2125 /*isLvalue=*/true); 2126 return false; 2127} 2128 2129/// TryContextuallyConvertToBool - Attempt to contextually convert the 2130/// expression From to bool (C++0x [conv]p3). 2131ImplicitConversionSequence Sema::TryContextuallyConvertToBool(Expr *From) { 2132 return TryImplicitConversion(From, Context.BoolTy, 2133 // FIXME: Are these flags correct? 2134 /*SuppressUserConversions=*/false, 2135 /*AllowExplicit=*/true, 2136 /*ForceRValue=*/false, 2137 /*InOverloadResolution=*/false); 2138} 2139 2140/// PerformContextuallyConvertToBool - Perform a contextual conversion 2141/// of the expression From to bool (C++0x [conv]p3). 2142bool Sema::PerformContextuallyConvertToBool(Expr *&From) { 2143 ImplicitConversionSequence ICS = TryContextuallyConvertToBool(From); 2144 if (!PerformImplicitConversion(From, Context.BoolTy, ICS, "converting")) 2145 return false; 2146 2147 if (!DiagnoseAmbiguousUserDefinedConversion(From, Context.BoolTy)) 2148 return Diag(From->getSourceRange().getBegin(), 2149 diag::err_typecheck_bool_condition) 2150 << From->getType() << From->getSourceRange(); 2151 return true; 2152} 2153 2154/// AddOverloadCandidate - Adds the given function to the set of 2155/// candidate functions, using the given function call arguments. If 2156/// @p SuppressUserConversions, then don't allow user-defined 2157/// conversions via constructors or conversion operators. 2158/// If @p ForceRValue, treat all arguments as rvalues. This is a slightly 2159/// hacky way to implement the overloading rules for elidable copy 2160/// initialization in C++0x (C++0x 12.8p15). 2161/// 2162/// \para PartialOverloading true if we are performing "partial" overloading 2163/// based on an incomplete set of function arguments. This feature is used by 2164/// code completion. 2165void 2166Sema::AddOverloadCandidate(FunctionDecl *Function, 2167 Expr **Args, unsigned NumArgs, 2168 OverloadCandidateSet& CandidateSet, 2169 bool SuppressUserConversions, 2170 bool ForceRValue, 2171 bool PartialOverloading) { 2172 const FunctionProtoType* Proto 2173 = dyn_cast<FunctionProtoType>(Function->getType()->getAs<FunctionType>()); 2174 assert(Proto && "Functions without a prototype cannot be overloaded"); 2175 assert(!isa<CXXConversionDecl>(Function) && 2176 "Use AddConversionCandidate for conversion functions"); 2177 assert(!Function->getDescribedFunctionTemplate() && 2178 "Use AddTemplateOverloadCandidate for function templates"); 2179 2180 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Function)) { 2181 if (!isa<CXXConstructorDecl>(Method)) { 2182 // If we get here, it's because we're calling a member function 2183 // that is named without a member access expression (e.g., 2184 // "this->f") that was either written explicitly or created 2185 // implicitly. This can happen with a qualified call to a member 2186 // function, e.g., X::f(). We use a NULL object as the implied 2187 // object argument (C++ [over.call.func]p3). 2188 AddMethodCandidate(Method, 0, Args, NumArgs, CandidateSet, 2189 SuppressUserConversions, ForceRValue); 2190 return; 2191 } 2192 // We treat a constructor like a non-member function, since its object 2193 // argument doesn't participate in overload resolution. 2194 } 2195 2196 if (!CandidateSet.isNewCandidate(Function)) 2197 return; 2198 2199 // Add this candidate 2200 CandidateSet.push_back(OverloadCandidate()); 2201 OverloadCandidate& Candidate = CandidateSet.back(); 2202 Candidate.Function = Function; 2203 Candidate.Viable = true; 2204 Candidate.IsSurrogate = false; 2205 Candidate.IgnoreObjectArgument = false; 2206 2207 unsigned NumArgsInProto = Proto->getNumArgs(); 2208 2209 // (C++ 13.3.2p2): A candidate function having fewer than m 2210 // parameters is viable only if it has an ellipsis in its parameter 2211 // list (8.3.5). 2212 if ((NumArgs + (PartialOverloading && NumArgs)) > NumArgsInProto && 2213 !Proto->isVariadic()) { 2214 Candidate.Viable = false; 2215 return; 2216 } 2217 2218 // (C++ 13.3.2p2): A candidate function having more than m parameters 2219 // is viable only if the (m+1)st parameter has a default argument 2220 // (8.3.6). For the purposes of overload resolution, the 2221 // parameter list is truncated on the right, so that there are 2222 // exactly m parameters. 2223 unsigned MinRequiredArgs = Function->getMinRequiredArguments(); 2224 if (NumArgs < MinRequiredArgs && !PartialOverloading) { 2225 // Not enough arguments. 2226 Candidate.Viable = false; 2227 return; 2228 } 2229 2230 // Determine the implicit conversion sequences for each of the 2231 // arguments. 2232 Candidate.Conversions.resize(NumArgs); 2233 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2234 if (ArgIdx < NumArgsInProto) { 2235 // (C++ 13.3.2p3): for F to be a viable function, there shall 2236 // exist for each argument an implicit conversion sequence 2237 // (13.3.3.1) that converts that argument to the corresponding 2238 // parameter of F. 2239 QualType ParamType = Proto->getArgType(ArgIdx); 2240 Candidate.Conversions[ArgIdx] 2241 = TryCopyInitialization(Args[ArgIdx], ParamType, 2242 SuppressUserConversions, ForceRValue, 2243 /*InOverloadResolution=*/true); 2244 if (Candidate.Conversions[ArgIdx].ConversionKind 2245 == ImplicitConversionSequence::BadConversion) { 2246 // 13.3.3.1-p10 If several different sequences of conversions exist that 2247 // each convert the argument to the parameter type, the implicit conversion 2248 // sequence associated with the parameter is defined to be the unique conversion 2249 // sequence designated the ambiguous conversion sequence. For the purpose of 2250 // ranking implicit conversion sequences as described in 13.3.3.2, the ambiguous 2251 // conversion sequence is treated as a user-defined sequence that is 2252 // indistinguishable from any other user-defined conversion sequence 2253 if (!Candidate.Conversions[ArgIdx].ConversionFunctionSet.empty()) { 2254 Candidate.Conversions[ArgIdx].ConversionKind = 2255 ImplicitConversionSequence::UserDefinedConversion; 2256 // Set the conversion function to one of them. As due to ambiguity, 2257 // they carry the same weight and is needed for overload resolution 2258 // later. 2259 Candidate.Conversions[ArgIdx].UserDefined.ConversionFunction = 2260 Candidate.Conversions[ArgIdx].ConversionFunctionSet[0]; 2261 } 2262 else { 2263 Candidate.Viable = false; 2264 break; 2265 } 2266 } 2267 } else { 2268 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2269 // argument for which there is no corresponding parameter is 2270 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2271 Candidate.Conversions[ArgIdx].ConversionKind 2272 = ImplicitConversionSequence::EllipsisConversion; 2273 } 2274 } 2275} 2276 2277/// \brief Add all of the function declarations in the given function set to 2278/// the overload canddiate set. 2279void Sema::AddFunctionCandidates(const FunctionSet &Functions, 2280 Expr **Args, unsigned NumArgs, 2281 OverloadCandidateSet& CandidateSet, 2282 bool SuppressUserConversions) { 2283 for (FunctionSet::const_iterator F = Functions.begin(), 2284 FEnd = Functions.end(); 2285 F != FEnd; ++F) { 2286 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*F)) { 2287 if (isa<CXXMethodDecl>(FD) && !cast<CXXMethodDecl>(FD)->isStatic()) 2288 AddMethodCandidate(cast<CXXMethodDecl>(FD), 2289 Args[0], Args + 1, NumArgs - 1, 2290 CandidateSet, SuppressUserConversions); 2291 else 2292 AddOverloadCandidate(FD, Args, NumArgs, CandidateSet, 2293 SuppressUserConversions); 2294 } else { 2295 FunctionTemplateDecl *FunTmpl = cast<FunctionTemplateDecl>(*F); 2296 if (isa<CXXMethodDecl>(FunTmpl->getTemplatedDecl()) && 2297 !cast<CXXMethodDecl>(FunTmpl->getTemplatedDecl())->isStatic()) 2298 AddMethodTemplateCandidate(FunTmpl, 2299 /*FIXME: explicit args */false, 0, 0, 2300 Args[0], Args + 1, NumArgs - 1, 2301 CandidateSet, 2302 SuppressUserConversions); 2303 else 2304 AddTemplateOverloadCandidate(FunTmpl, 2305 /*FIXME: explicit args */false, 0, 0, 2306 Args, NumArgs, CandidateSet, 2307 SuppressUserConversions); 2308 } 2309 } 2310} 2311 2312/// AddMethodCandidate - Adds the given C++ member function to the set 2313/// of candidate functions, using the given function call arguments 2314/// and the object argument (@c Object). For example, in a call 2315/// @c o.f(a1,a2), @c Object will contain @c o and @c Args will contain 2316/// both @c a1 and @c a2. If @p SuppressUserConversions, then don't 2317/// allow user-defined conversions via constructors or conversion 2318/// operators. If @p ForceRValue, treat all arguments as rvalues. This is 2319/// a slightly hacky way to implement the overloading rules for elidable copy 2320/// initialization in C++0x (C++0x 12.8p15). 2321void 2322Sema::AddMethodCandidate(CXXMethodDecl *Method, Expr *Object, 2323 Expr **Args, unsigned NumArgs, 2324 OverloadCandidateSet& CandidateSet, 2325 bool SuppressUserConversions, bool ForceRValue) { 2326 const FunctionProtoType* Proto 2327 = dyn_cast<FunctionProtoType>(Method->getType()->getAs<FunctionType>()); 2328 assert(Proto && "Methods without a prototype cannot be overloaded"); 2329 assert(!isa<CXXConversionDecl>(Method) && 2330 "Use AddConversionCandidate for conversion functions"); 2331 assert(!isa<CXXConstructorDecl>(Method) && 2332 "Use AddOverloadCandidate for constructors"); 2333 2334 if (!CandidateSet.isNewCandidate(Method)) 2335 return; 2336 2337 // Add this candidate 2338 CandidateSet.push_back(OverloadCandidate()); 2339 OverloadCandidate& Candidate = CandidateSet.back(); 2340 Candidate.Function = Method; 2341 Candidate.IsSurrogate = false; 2342 Candidate.IgnoreObjectArgument = false; 2343 2344 unsigned NumArgsInProto = Proto->getNumArgs(); 2345 2346 // (C++ 13.3.2p2): A candidate function having fewer than m 2347 // parameters is viable only if it has an ellipsis in its parameter 2348 // list (8.3.5). 2349 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 2350 Candidate.Viable = false; 2351 return; 2352 } 2353 2354 // (C++ 13.3.2p2): A candidate function having more than m parameters 2355 // is viable only if the (m+1)st parameter has a default argument 2356 // (8.3.6). For the purposes of overload resolution, the 2357 // parameter list is truncated on the right, so that there are 2358 // exactly m parameters. 2359 unsigned MinRequiredArgs = Method->getMinRequiredArguments(); 2360 if (NumArgs < MinRequiredArgs) { 2361 // Not enough arguments. 2362 Candidate.Viable = false; 2363 return; 2364 } 2365 2366 Candidate.Viable = true; 2367 Candidate.Conversions.resize(NumArgs + 1); 2368 2369 if (Method->isStatic() || !Object) 2370 // The implicit object argument is ignored. 2371 Candidate.IgnoreObjectArgument = true; 2372 else { 2373 // Determine the implicit conversion sequence for the object 2374 // parameter. 2375 Candidate.Conversions[0] = TryObjectArgumentInitialization(Object, Method); 2376 if (Candidate.Conversions[0].ConversionKind 2377 == ImplicitConversionSequence::BadConversion) { 2378 Candidate.Viable = false; 2379 return; 2380 } 2381 } 2382 2383 // Determine the implicit conversion sequences for each of the 2384 // arguments. 2385 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2386 if (ArgIdx < NumArgsInProto) { 2387 // (C++ 13.3.2p3): for F to be a viable function, there shall 2388 // exist for each argument an implicit conversion sequence 2389 // (13.3.3.1) that converts that argument to the corresponding 2390 // parameter of F. 2391 QualType ParamType = Proto->getArgType(ArgIdx); 2392 Candidate.Conversions[ArgIdx + 1] 2393 = TryCopyInitialization(Args[ArgIdx], ParamType, 2394 SuppressUserConversions, ForceRValue, 2395 /*InOverloadResolution=*/true); 2396 if (Candidate.Conversions[ArgIdx + 1].ConversionKind 2397 == ImplicitConversionSequence::BadConversion) { 2398 Candidate.Viable = false; 2399 break; 2400 } 2401 } else { 2402 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2403 // argument for which there is no corresponding parameter is 2404 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2405 Candidate.Conversions[ArgIdx + 1].ConversionKind 2406 = ImplicitConversionSequence::EllipsisConversion; 2407 } 2408 } 2409} 2410 2411/// \brief Add a C++ member function template as a candidate to the candidate 2412/// set, using template argument deduction to produce an appropriate member 2413/// function template specialization. 2414void 2415Sema::AddMethodTemplateCandidate(FunctionTemplateDecl *MethodTmpl, 2416 bool HasExplicitTemplateArgs, 2417 const TemplateArgument *ExplicitTemplateArgs, 2418 unsigned NumExplicitTemplateArgs, 2419 Expr *Object, Expr **Args, unsigned NumArgs, 2420 OverloadCandidateSet& CandidateSet, 2421 bool SuppressUserConversions, 2422 bool ForceRValue) { 2423 if (!CandidateSet.isNewCandidate(MethodTmpl)) 2424 return; 2425 2426 // C++ [over.match.funcs]p7: 2427 // In each case where a candidate is a function template, candidate 2428 // function template specializations are generated using template argument 2429 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 2430 // candidate functions in the usual way.113) A given name can refer to one 2431 // or more function templates and also to a set of overloaded non-template 2432 // functions. In such a case, the candidate functions generated from each 2433 // function template are combined with the set of non-template candidate 2434 // functions. 2435 TemplateDeductionInfo Info(Context); 2436 FunctionDecl *Specialization = 0; 2437 if (TemplateDeductionResult Result 2438 = DeduceTemplateArguments(MethodTmpl, HasExplicitTemplateArgs, 2439 ExplicitTemplateArgs, NumExplicitTemplateArgs, 2440 Args, NumArgs, Specialization, Info)) { 2441 // FIXME: Record what happened with template argument deduction, so 2442 // that we can give the user a beautiful diagnostic. 2443 (void)Result; 2444 return; 2445 } 2446 2447 // Add the function template specialization produced by template argument 2448 // deduction as a candidate. 2449 assert(Specialization && "Missing member function template specialization?"); 2450 assert(isa<CXXMethodDecl>(Specialization) && 2451 "Specialization is not a member function?"); 2452 AddMethodCandidate(cast<CXXMethodDecl>(Specialization), Object, Args, NumArgs, 2453 CandidateSet, SuppressUserConversions, ForceRValue); 2454} 2455 2456/// \brief Add a C++ function template specialization as a candidate 2457/// in the candidate set, using template argument deduction to produce 2458/// an appropriate function template specialization. 2459void 2460Sema::AddTemplateOverloadCandidate(FunctionTemplateDecl *FunctionTemplate, 2461 bool HasExplicitTemplateArgs, 2462 const TemplateArgument *ExplicitTemplateArgs, 2463 unsigned NumExplicitTemplateArgs, 2464 Expr **Args, unsigned NumArgs, 2465 OverloadCandidateSet& CandidateSet, 2466 bool SuppressUserConversions, 2467 bool ForceRValue) { 2468 if (!CandidateSet.isNewCandidate(FunctionTemplate)) 2469 return; 2470 2471 // C++ [over.match.funcs]p7: 2472 // In each case where a candidate is a function template, candidate 2473 // function template specializations are generated using template argument 2474 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 2475 // candidate functions in the usual way.113) A given name can refer to one 2476 // or more function templates and also to a set of overloaded non-template 2477 // functions. In such a case, the candidate functions generated from each 2478 // function template are combined with the set of non-template candidate 2479 // functions. 2480 TemplateDeductionInfo Info(Context); 2481 FunctionDecl *Specialization = 0; 2482 if (TemplateDeductionResult Result 2483 = DeduceTemplateArguments(FunctionTemplate, HasExplicitTemplateArgs, 2484 ExplicitTemplateArgs, NumExplicitTemplateArgs, 2485 Args, NumArgs, Specialization, Info)) { 2486 // FIXME: Record what happened with template argument deduction, so 2487 // that we can give the user a beautiful diagnostic. 2488 (void)Result; 2489 return; 2490 } 2491 2492 // Add the function template specialization produced by template argument 2493 // deduction as a candidate. 2494 assert(Specialization && "Missing function template specialization?"); 2495 AddOverloadCandidate(Specialization, Args, NumArgs, CandidateSet, 2496 SuppressUserConversions, ForceRValue); 2497} 2498 2499/// AddConversionCandidate - Add a C++ conversion function as a 2500/// candidate in the candidate set (C++ [over.match.conv], 2501/// C++ [over.match.copy]). From is the expression we're converting from, 2502/// and ToType is the type that we're eventually trying to convert to 2503/// (which may or may not be the same type as the type that the 2504/// conversion function produces). 2505void 2506Sema::AddConversionCandidate(CXXConversionDecl *Conversion, 2507 Expr *From, QualType ToType, 2508 OverloadCandidateSet& CandidateSet) { 2509 assert(!Conversion->getDescribedFunctionTemplate() && 2510 "Conversion function templates use AddTemplateConversionCandidate"); 2511 2512 if (!CandidateSet.isNewCandidate(Conversion)) 2513 return; 2514 2515 // Add this candidate 2516 CandidateSet.push_back(OverloadCandidate()); 2517 OverloadCandidate& Candidate = CandidateSet.back(); 2518 Candidate.Function = Conversion; 2519 Candidate.IsSurrogate = false; 2520 Candidate.IgnoreObjectArgument = false; 2521 Candidate.FinalConversion.setAsIdentityConversion(); 2522 Candidate.FinalConversion.FromTypePtr 2523 = Conversion->getConversionType().getAsOpaquePtr(); 2524 Candidate.FinalConversion.ToTypePtr = ToType.getAsOpaquePtr(); 2525 2526 // Determine the implicit conversion sequence for the implicit 2527 // object parameter. 2528 Candidate.Viable = true; 2529 Candidate.Conversions.resize(1); 2530 Candidate.Conversions[0] = TryObjectArgumentInitialization(From, Conversion); 2531 // Conversion functions to a different type in the base class is visible in 2532 // the derived class. So, a derived to base conversion should not participate 2533 // in overload resolution. 2534 if (Candidate.Conversions[0].Standard.Second == ICK_Derived_To_Base) 2535 Candidate.Conversions[0].Standard.Second = ICK_Identity; 2536 if (Candidate.Conversions[0].ConversionKind 2537 == ImplicitConversionSequence::BadConversion) { 2538 Candidate.Viable = false; 2539 return; 2540 } 2541 2542 // To determine what the conversion from the result of calling the 2543 // conversion function to the type we're eventually trying to 2544 // convert to (ToType), we need to synthesize a call to the 2545 // conversion function and attempt copy initialization from it. This 2546 // makes sure that we get the right semantics with respect to 2547 // lvalues/rvalues and the type. Fortunately, we can allocate this 2548 // call on the stack and we don't need its arguments to be 2549 // well-formed. 2550 DeclRefExpr ConversionRef(Conversion, Conversion->getType(), 2551 SourceLocation()); 2552 ImplicitCastExpr ConversionFn(Context.getPointerType(Conversion->getType()), 2553 CastExpr::CK_Unknown, 2554 &ConversionRef, false); 2555 2556 // Note that it is safe to allocate CallExpr on the stack here because 2557 // there are 0 arguments (i.e., nothing is allocated using ASTContext's 2558 // allocator). 2559 CallExpr Call(Context, &ConversionFn, 0, 0, 2560 Conversion->getConversionType().getNonReferenceType(), 2561 SourceLocation()); 2562 ImplicitConversionSequence ICS = 2563 TryCopyInitialization(&Call, ToType, 2564 /*SuppressUserConversions=*/true, 2565 /*ForceRValue=*/false, 2566 /*InOverloadResolution=*/false); 2567 2568 switch (ICS.ConversionKind) { 2569 case ImplicitConversionSequence::StandardConversion: 2570 Candidate.FinalConversion = ICS.Standard; 2571 break; 2572 2573 case ImplicitConversionSequence::BadConversion: 2574 Candidate.Viable = false; 2575 break; 2576 2577 default: 2578 assert(false && 2579 "Can only end up with a standard conversion sequence or failure"); 2580 } 2581} 2582 2583/// \brief Adds a conversion function template specialization 2584/// candidate to the overload set, using template argument deduction 2585/// to deduce the template arguments of the conversion function 2586/// template from the type that we are converting to (C++ 2587/// [temp.deduct.conv]). 2588void 2589Sema::AddTemplateConversionCandidate(FunctionTemplateDecl *FunctionTemplate, 2590 Expr *From, QualType ToType, 2591 OverloadCandidateSet &CandidateSet) { 2592 assert(isa<CXXConversionDecl>(FunctionTemplate->getTemplatedDecl()) && 2593 "Only conversion function templates permitted here"); 2594 2595 if (!CandidateSet.isNewCandidate(FunctionTemplate)) 2596 return; 2597 2598 TemplateDeductionInfo Info(Context); 2599 CXXConversionDecl *Specialization = 0; 2600 if (TemplateDeductionResult Result 2601 = DeduceTemplateArguments(FunctionTemplate, ToType, 2602 Specialization, Info)) { 2603 // FIXME: Record what happened with template argument deduction, so 2604 // that we can give the user a beautiful diagnostic. 2605 (void)Result; 2606 return; 2607 } 2608 2609 // Add the conversion function template specialization produced by 2610 // template argument deduction as a candidate. 2611 assert(Specialization && "Missing function template specialization?"); 2612 AddConversionCandidate(Specialization, From, ToType, CandidateSet); 2613} 2614 2615/// AddSurrogateCandidate - Adds a "surrogate" candidate function that 2616/// converts the given @c Object to a function pointer via the 2617/// conversion function @c Conversion, and then attempts to call it 2618/// with the given arguments (C++ [over.call.object]p2-4). Proto is 2619/// the type of function that we'll eventually be calling. 2620void Sema::AddSurrogateCandidate(CXXConversionDecl *Conversion, 2621 const FunctionProtoType *Proto, 2622 Expr *Object, Expr **Args, unsigned NumArgs, 2623 OverloadCandidateSet& CandidateSet) { 2624 if (!CandidateSet.isNewCandidate(Conversion)) 2625 return; 2626 2627 CandidateSet.push_back(OverloadCandidate()); 2628 OverloadCandidate& Candidate = CandidateSet.back(); 2629 Candidate.Function = 0; 2630 Candidate.Surrogate = Conversion; 2631 Candidate.Viable = true; 2632 Candidate.IsSurrogate = true; 2633 Candidate.IgnoreObjectArgument = false; 2634 Candidate.Conversions.resize(NumArgs + 1); 2635 2636 // Determine the implicit conversion sequence for the implicit 2637 // object parameter. 2638 ImplicitConversionSequence ObjectInit 2639 = TryObjectArgumentInitialization(Object, Conversion); 2640 if (ObjectInit.ConversionKind == ImplicitConversionSequence::BadConversion) { 2641 Candidate.Viable = false; 2642 return; 2643 } 2644 2645 // The first conversion is actually a user-defined conversion whose 2646 // first conversion is ObjectInit's standard conversion (which is 2647 // effectively a reference binding). Record it as such. 2648 Candidate.Conversions[0].ConversionKind 2649 = ImplicitConversionSequence::UserDefinedConversion; 2650 Candidate.Conversions[0].UserDefined.Before = ObjectInit.Standard; 2651 Candidate.Conversions[0].UserDefined.ConversionFunction = Conversion; 2652 Candidate.Conversions[0].UserDefined.After 2653 = Candidate.Conversions[0].UserDefined.Before; 2654 Candidate.Conversions[0].UserDefined.After.setAsIdentityConversion(); 2655 2656 // Find the 2657 unsigned NumArgsInProto = Proto->getNumArgs(); 2658 2659 // (C++ 13.3.2p2): A candidate function having fewer than m 2660 // parameters is viable only if it has an ellipsis in its parameter 2661 // list (8.3.5). 2662 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 2663 Candidate.Viable = false; 2664 return; 2665 } 2666 2667 // Function types don't have any default arguments, so just check if 2668 // we have enough arguments. 2669 if (NumArgs < NumArgsInProto) { 2670 // Not enough arguments. 2671 Candidate.Viable = false; 2672 return; 2673 } 2674 2675 // Determine the implicit conversion sequences for each of the 2676 // arguments. 2677 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2678 if (ArgIdx < NumArgsInProto) { 2679 // (C++ 13.3.2p3): for F to be a viable function, there shall 2680 // exist for each argument an implicit conversion sequence 2681 // (13.3.3.1) that converts that argument to the corresponding 2682 // parameter of F. 2683 QualType ParamType = Proto->getArgType(ArgIdx); 2684 Candidate.Conversions[ArgIdx + 1] 2685 = TryCopyInitialization(Args[ArgIdx], ParamType, 2686 /*SuppressUserConversions=*/false, 2687 /*ForceRValue=*/false, 2688 /*InOverloadResolution=*/false); 2689 if (Candidate.Conversions[ArgIdx + 1].ConversionKind 2690 == ImplicitConversionSequence::BadConversion) { 2691 Candidate.Viable = false; 2692 break; 2693 } 2694 } else { 2695 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2696 // argument for which there is no corresponding parameter is 2697 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2698 Candidate.Conversions[ArgIdx + 1].ConversionKind 2699 = ImplicitConversionSequence::EllipsisConversion; 2700 } 2701 } 2702} 2703 2704// FIXME: This will eventually be removed, once we've migrated all of the 2705// operator overloading logic over to the scheme used by binary operators, which 2706// works for template instantiation. 2707void Sema::AddOperatorCandidates(OverloadedOperatorKind Op, Scope *S, 2708 SourceLocation OpLoc, 2709 Expr **Args, unsigned NumArgs, 2710 OverloadCandidateSet& CandidateSet, 2711 SourceRange OpRange) { 2712 FunctionSet Functions; 2713 2714 QualType T1 = Args[0]->getType(); 2715 QualType T2; 2716 if (NumArgs > 1) 2717 T2 = Args[1]->getType(); 2718 2719 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 2720 if (S) 2721 LookupOverloadedOperatorName(Op, S, T1, T2, Functions); 2722 ArgumentDependentLookup(OpName, Args, NumArgs, Functions); 2723 AddFunctionCandidates(Functions, Args, NumArgs, CandidateSet); 2724 AddMemberOperatorCandidates(Op, OpLoc, Args, NumArgs, CandidateSet, OpRange); 2725 AddBuiltinOperatorCandidates(Op, Args, NumArgs, CandidateSet); 2726} 2727 2728/// \brief Add overload candidates for overloaded operators that are 2729/// member functions. 2730/// 2731/// Add the overloaded operator candidates that are member functions 2732/// for the operator Op that was used in an operator expression such 2733/// as "x Op y". , Args/NumArgs provides the operator arguments, and 2734/// CandidateSet will store the added overload candidates. (C++ 2735/// [over.match.oper]). 2736void Sema::AddMemberOperatorCandidates(OverloadedOperatorKind Op, 2737 SourceLocation OpLoc, 2738 Expr **Args, unsigned NumArgs, 2739 OverloadCandidateSet& CandidateSet, 2740 SourceRange OpRange) { 2741 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 2742 2743 // C++ [over.match.oper]p3: 2744 // For a unary operator @ with an operand of a type whose 2745 // cv-unqualified version is T1, and for a binary operator @ with 2746 // a left operand of a type whose cv-unqualified version is T1 and 2747 // a right operand of a type whose cv-unqualified version is T2, 2748 // three sets of candidate functions, designated member 2749 // candidates, non-member candidates and built-in candidates, are 2750 // constructed as follows: 2751 QualType T1 = Args[0]->getType(); 2752 QualType T2; 2753 if (NumArgs > 1) 2754 T2 = Args[1]->getType(); 2755 2756 // -- If T1 is a class type, the set of member candidates is the 2757 // result of the qualified lookup of T1::operator@ 2758 // (13.3.1.1.1); otherwise, the set of member candidates is 2759 // empty. 2760 if (const RecordType *T1Rec = T1->getAs<RecordType>()) { 2761 // Complete the type if it can be completed. Otherwise, we're done. 2762 if (RequireCompleteType(OpLoc, T1, PartialDiagnostic(0))) 2763 return; 2764 2765 LookupResult Operators = LookupQualifiedName(T1Rec->getDecl(), OpName, 2766 LookupOrdinaryName, false); 2767 for (LookupResult::iterator Oper = Operators.begin(), 2768 OperEnd = Operators.end(); 2769 Oper != OperEnd; 2770 ++Oper) 2771 AddMethodCandidate(cast<CXXMethodDecl>(*Oper), Args[0], 2772 Args+1, NumArgs - 1, CandidateSet, 2773 /*SuppressUserConversions=*/false); 2774 } 2775} 2776 2777/// AddBuiltinCandidate - Add a candidate for a built-in 2778/// operator. ResultTy and ParamTys are the result and parameter types 2779/// of the built-in candidate, respectively. Args and NumArgs are the 2780/// arguments being passed to the candidate. IsAssignmentOperator 2781/// should be true when this built-in candidate is an assignment 2782/// operator. NumContextualBoolArguments is the number of arguments 2783/// (at the beginning of the argument list) that will be contextually 2784/// converted to bool. 2785void Sema::AddBuiltinCandidate(QualType ResultTy, QualType *ParamTys, 2786 Expr **Args, unsigned NumArgs, 2787 OverloadCandidateSet& CandidateSet, 2788 bool IsAssignmentOperator, 2789 unsigned NumContextualBoolArguments) { 2790 // Add this candidate 2791 CandidateSet.push_back(OverloadCandidate()); 2792 OverloadCandidate& Candidate = CandidateSet.back(); 2793 Candidate.Function = 0; 2794 Candidate.IsSurrogate = false; 2795 Candidate.IgnoreObjectArgument = false; 2796 Candidate.BuiltinTypes.ResultTy = ResultTy; 2797 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 2798 Candidate.BuiltinTypes.ParamTypes[ArgIdx] = ParamTys[ArgIdx]; 2799 2800 // Determine the implicit conversion sequences for each of the 2801 // arguments. 2802 Candidate.Viable = true; 2803 Candidate.Conversions.resize(NumArgs); 2804 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2805 // C++ [over.match.oper]p4: 2806 // For the built-in assignment operators, conversions of the 2807 // left operand are restricted as follows: 2808 // -- no temporaries are introduced to hold the left operand, and 2809 // -- no user-defined conversions are applied to the left 2810 // operand to achieve a type match with the left-most 2811 // parameter of a built-in candidate. 2812 // 2813 // We block these conversions by turning off user-defined 2814 // conversions, since that is the only way that initialization of 2815 // a reference to a non-class type can occur from something that 2816 // is not of the same type. 2817 if (ArgIdx < NumContextualBoolArguments) { 2818 assert(ParamTys[ArgIdx] == Context.BoolTy && 2819 "Contextual conversion to bool requires bool type"); 2820 Candidate.Conversions[ArgIdx] = TryContextuallyConvertToBool(Args[ArgIdx]); 2821 } else { 2822 Candidate.Conversions[ArgIdx] 2823 = TryCopyInitialization(Args[ArgIdx], ParamTys[ArgIdx], 2824 ArgIdx == 0 && IsAssignmentOperator, 2825 /*ForceRValue=*/false, 2826 /*InOverloadResolution=*/false); 2827 } 2828 if (Candidate.Conversions[ArgIdx].ConversionKind 2829 == ImplicitConversionSequence::BadConversion) { 2830 Candidate.Viable = false; 2831 break; 2832 } 2833 } 2834} 2835 2836/// BuiltinCandidateTypeSet - A set of types that will be used for the 2837/// candidate operator functions for built-in operators (C++ 2838/// [over.built]). The types are separated into pointer types and 2839/// enumeration types. 2840class BuiltinCandidateTypeSet { 2841 /// TypeSet - A set of types. 2842 typedef llvm::SmallPtrSet<QualType, 8> TypeSet; 2843 2844 /// PointerTypes - The set of pointer types that will be used in the 2845 /// built-in candidates. 2846 TypeSet PointerTypes; 2847 2848 /// MemberPointerTypes - The set of member pointer types that will be 2849 /// used in the built-in candidates. 2850 TypeSet MemberPointerTypes; 2851 2852 /// EnumerationTypes - The set of enumeration types that will be 2853 /// used in the built-in candidates. 2854 TypeSet EnumerationTypes; 2855 2856 /// Sema - The semantic analysis instance where we are building the 2857 /// candidate type set. 2858 Sema &SemaRef; 2859 2860 /// Context - The AST context in which we will build the type sets. 2861 ASTContext &Context; 2862 2863 bool AddPointerWithMoreQualifiedTypeVariants(QualType Ty); 2864 bool AddMemberPointerWithMoreQualifiedTypeVariants(QualType Ty); 2865 2866public: 2867 /// iterator - Iterates through the types that are part of the set. 2868 typedef TypeSet::iterator iterator; 2869 2870 BuiltinCandidateTypeSet(Sema &SemaRef) 2871 : SemaRef(SemaRef), Context(SemaRef.Context) { } 2872 2873 void AddTypesConvertedFrom(QualType Ty, bool AllowUserConversions, 2874 bool AllowExplicitConversions); 2875 2876 /// pointer_begin - First pointer type found; 2877 iterator pointer_begin() { return PointerTypes.begin(); } 2878 2879 /// pointer_end - Past the last pointer type found; 2880 iterator pointer_end() { return PointerTypes.end(); } 2881 2882 /// member_pointer_begin - First member pointer type found; 2883 iterator member_pointer_begin() { return MemberPointerTypes.begin(); } 2884 2885 /// member_pointer_end - Past the last member pointer type found; 2886 iterator member_pointer_end() { return MemberPointerTypes.end(); } 2887 2888 /// enumeration_begin - First enumeration type found; 2889 iterator enumeration_begin() { return EnumerationTypes.begin(); } 2890 2891 /// enumeration_end - Past the last enumeration type found; 2892 iterator enumeration_end() { return EnumerationTypes.end(); } 2893}; 2894 2895/// AddPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty to 2896/// the set of pointer types along with any more-qualified variants of 2897/// that type. For example, if @p Ty is "int const *", this routine 2898/// will add "int const *", "int const volatile *", "int const 2899/// restrict *", and "int const volatile restrict *" to the set of 2900/// pointer types. Returns true if the add of @p Ty itself succeeded, 2901/// false otherwise. 2902/// 2903/// FIXME: what to do about extended qualifiers? 2904bool 2905BuiltinCandidateTypeSet::AddPointerWithMoreQualifiedTypeVariants(QualType Ty) { 2906 2907 // Insert this type. 2908 if (!PointerTypes.insert(Ty)) 2909 return false; 2910 2911 const PointerType *PointerTy = Ty->getAs<PointerType>(); 2912 assert(PointerTy && "type was not a pointer type!"); 2913 2914 QualType PointeeTy = PointerTy->getPointeeType(); 2915 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 2916 2917 // Iterate through all strict supersets of BaseCVR. 2918 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 2919 if ((CVR | BaseCVR) != CVR) continue; 2920 2921 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 2922 PointerTypes.insert(Context.getPointerType(QPointeeTy)); 2923 } 2924 2925 return true; 2926} 2927 2928/// AddMemberPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty 2929/// to the set of pointer types along with any more-qualified variants of 2930/// that type. For example, if @p Ty is "int const *", this routine 2931/// will add "int const *", "int const volatile *", "int const 2932/// restrict *", and "int const volatile restrict *" to the set of 2933/// pointer types. Returns true if the add of @p Ty itself succeeded, 2934/// false otherwise. 2935/// 2936/// FIXME: what to do about extended qualifiers? 2937bool 2938BuiltinCandidateTypeSet::AddMemberPointerWithMoreQualifiedTypeVariants( 2939 QualType Ty) { 2940 // Insert this type. 2941 if (!MemberPointerTypes.insert(Ty)) 2942 return false; 2943 2944 const MemberPointerType *PointerTy = Ty->getAs<MemberPointerType>(); 2945 assert(PointerTy && "type was not a member pointer type!"); 2946 2947 QualType PointeeTy = PointerTy->getPointeeType(); 2948 const Type *ClassTy = PointerTy->getClass(); 2949 2950 // Iterate through all strict supersets of the pointee type's CVR 2951 // qualifiers. 2952 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 2953 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 2954 if ((CVR | BaseCVR) != CVR) continue; 2955 2956 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 2957 MemberPointerTypes.insert(Context.getMemberPointerType(QPointeeTy, ClassTy)); 2958 } 2959 2960 return true; 2961} 2962 2963/// AddTypesConvertedFrom - Add each of the types to which the type @p 2964/// Ty can be implicit converted to the given set of @p Types. We're 2965/// primarily interested in pointer types and enumeration types. We also 2966/// take member pointer types, for the conditional operator. 2967/// AllowUserConversions is true if we should look at the conversion 2968/// functions of a class type, and AllowExplicitConversions if we 2969/// should also include the explicit conversion functions of a class 2970/// type. 2971void 2972BuiltinCandidateTypeSet::AddTypesConvertedFrom(QualType Ty, 2973 bool AllowUserConversions, 2974 bool AllowExplicitConversions) { 2975 // Only deal with canonical types. 2976 Ty = Context.getCanonicalType(Ty); 2977 2978 // Look through reference types; they aren't part of the type of an 2979 // expression for the purposes of conversions. 2980 if (const ReferenceType *RefTy = Ty->getAs<ReferenceType>()) 2981 Ty = RefTy->getPointeeType(); 2982 2983 // We don't care about qualifiers on the type. 2984 Ty = Ty.getUnqualifiedType(); 2985 2986 if (const PointerType *PointerTy = Ty->getAs<PointerType>()) { 2987 QualType PointeeTy = PointerTy->getPointeeType(); 2988 2989 // Insert our type, and its more-qualified variants, into the set 2990 // of types. 2991 if (!AddPointerWithMoreQualifiedTypeVariants(Ty)) 2992 return; 2993 2994 // Add 'cv void*' to our set of types. 2995 if (!Ty->isVoidType()) { 2996 QualType QualVoid 2997 = Context.getCVRQualifiedType(Context.VoidTy, 2998 PointeeTy.getCVRQualifiers()); 2999 AddPointerWithMoreQualifiedTypeVariants(Context.getPointerType(QualVoid)); 3000 } 3001 3002 // If this is a pointer to a class type, add pointers to its bases 3003 // (with the same level of cv-qualification as the original 3004 // derived class, of course). 3005 if (const RecordType *PointeeRec = PointeeTy->getAs<RecordType>()) { 3006 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(PointeeRec->getDecl()); 3007 for (CXXRecordDecl::base_class_iterator Base = ClassDecl->bases_begin(); 3008 Base != ClassDecl->bases_end(); ++Base) { 3009 QualType BaseTy = Context.getCanonicalType(Base->getType()); 3010 BaseTy = Context.getCVRQualifiedType(BaseTy.getUnqualifiedType(), 3011 PointeeTy.getCVRQualifiers()); 3012 3013 // Add the pointer type, recursively, so that we get all of 3014 // the indirect base classes, too. 3015 AddTypesConvertedFrom(Context.getPointerType(BaseTy), false, false); 3016 } 3017 } 3018 } else if (Ty->isMemberPointerType()) { 3019 // Member pointers are far easier, since the pointee can't be converted. 3020 if (!AddMemberPointerWithMoreQualifiedTypeVariants(Ty)) 3021 return; 3022 } else if (Ty->isEnumeralType()) { 3023 EnumerationTypes.insert(Ty); 3024 } else if (AllowUserConversions) { 3025 if (const RecordType *TyRec = Ty->getAs<RecordType>()) { 3026 if (SemaRef.RequireCompleteType(SourceLocation(), Ty, 0)) { 3027 // No conversion functions in incomplete types. 3028 return; 3029 } 3030 3031 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 3032 // FIXME: Visit conversion functions in the base classes, too. 3033 OverloadedFunctionDecl *Conversions 3034 = ClassDecl->getConversionFunctions(); 3035 for (OverloadedFunctionDecl::function_iterator Func 3036 = Conversions->function_begin(); 3037 Func != Conversions->function_end(); ++Func) { 3038 CXXConversionDecl *Conv; 3039 FunctionTemplateDecl *ConvTemplate; 3040 GetFunctionAndTemplate(*Func, Conv, ConvTemplate); 3041 3042 // Skip conversion function templates; they don't tell us anything 3043 // about which builtin types we can convert to. 3044 if (ConvTemplate) 3045 continue; 3046 3047 if (AllowExplicitConversions || !Conv->isExplicit()) 3048 AddTypesConvertedFrom(Conv->getConversionType(), false, false); 3049 } 3050 } 3051 } 3052} 3053 3054/// \brief Helper function for AddBuiltinOperatorCandidates() that adds 3055/// the volatile- and non-volatile-qualified assignment operators for the 3056/// given type to the candidate set. 3057static void AddBuiltinAssignmentOperatorCandidates(Sema &S, 3058 QualType T, 3059 Expr **Args, 3060 unsigned NumArgs, 3061 OverloadCandidateSet &CandidateSet) { 3062 QualType ParamTypes[2]; 3063 3064 // T& operator=(T&, T) 3065 ParamTypes[0] = S.Context.getLValueReferenceType(T); 3066 ParamTypes[1] = T; 3067 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3068 /*IsAssignmentOperator=*/true); 3069 3070 if (!S.Context.getCanonicalType(T).isVolatileQualified()) { 3071 // volatile T& operator=(volatile T&, T) 3072 ParamTypes[0] 3073 = S.Context.getLValueReferenceType(S.Context.getVolatileType(T)); 3074 ParamTypes[1] = T; 3075 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3076 /*IsAssignmentOperator=*/true); 3077 } 3078} 3079 3080/// AddBuiltinOperatorCandidates - Add the appropriate built-in 3081/// operator overloads to the candidate set (C++ [over.built]), based 3082/// on the operator @p Op and the arguments given. For example, if the 3083/// operator is a binary '+', this routine might add "int 3084/// operator+(int, int)" to cover integer addition. 3085void 3086Sema::AddBuiltinOperatorCandidates(OverloadedOperatorKind Op, 3087 Expr **Args, unsigned NumArgs, 3088 OverloadCandidateSet& CandidateSet) { 3089 // The set of "promoted arithmetic types", which are the arithmetic 3090 // types are that preserved by promotion (C++ [over.built]p2). Note 3091 // that the first few of these types are the promoted integral 3092 // types; these types need to be first. 3093 // FIXME: What about complex? 3094 const unsigned FirstIntegralType = 0; 3095 const unsigned LastIntegralType = 13; 3096 const unsigned FirstPromotedIntegralType = 7, 3097 LastPromotedIntegralType = 13; 3098 const unsigned FirstPromotedArithmeticType = 7, 3099 LastPromotedArithmeticType = 16; 3100 const unsigned NumArithmeticTypes = 16; 3101 QualType ArithmeticTypes[NumArithmeticTypes] = { 3102 Context.BoolTy, Context.CharTy, Context.WCharTy, 3103// FIXME: Context.Char16Ty, Context.Char32Ty, 3104 Context.SignedCharTy, Context.ShortTy, 3105 Context.UnsignedCharTy, Context.UnsignedShortTy, 3106 Context.IntTy, Context.LongTy, Context.LongLongTy, 3107 Context.UnsignedIntTy, Context.UnsignedLongTy, Context.UnsignedLongLongTy, 3108 Context.FloatTy, Context.DoubleTy, Context.LongDoubleTy 3109 }; 3110 3111 // Find all of the types that the arguments can convert to, but only 3112 // if the operator we're looking at has built-in operator candidates 3113 // that make use of these types. 3114 BuiltinCandidateTypeSet CandidateTypes(*this); 3115 if (Op == OO_Less || Op == OO_Greater || Op == OO_LessEqual || 3116 Op == OO_GreaterEqual || Op == OO_EqualEqual || Op == OO_ExclaimEqual || 3117 Op == OO_Plus || (Op == OO_Minus && NumArgs == 2) || Op == OO_Equal || 3118 Op == OO_PlusEqual || Op == OO_MinusEqual || Op == OO_Subscript || 3119 Op == OO_ArrowStar || Op == OO_PlusPlus || Op == OO_MinusMinus || 3120 (Op == OO_Star && NumArgs == 1) || Op == OO_Conditional) { 3121 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 3122 CandidateTypes.AddTypesConvertedFrom(Args[ArgIdx]->getType(), 3123 true, 3124 (Op == OO_Exclaim || 3125 Op == OO_AmpAmp || 3126 Op == OO_PipePipe)); 3127 } 3128 3129 bool isComparison = false; 3130 switch (Op) { 3131 case OO_None: 3132 case NUM_OVERLOADED_OPERATORS: 3133 assert(false && "Expected an overloaded operator"); 3134 break; 3135 3136 case OO_Star: // '*' is either unary or binary 3137 if (NumArgs == 1) 3138 goto UnaryStar; 3139 else 3140 goto BinaryStar; 3141 break; 3142 3143 case OO_Plus: // '+' is either unary or binary 3144 if (NumArgs == 1) 3145 goto UnaryPlus; 3146 else 3147 goto BinaryPlus; 3148 break; 3149 3150 case OO_Minus: // '-' is either unary or binary 3151 if (NumArgs == 1) 3152 goto UnaryMinus; 3153 else 3154 goto BinaryMinus; 3155 break; 3156 3157 case OO_Amp: // '&' is either unary or binary 3158 if (NumArgs == 1) 3159 goto UnaryAmp; 3160 else 3161 goto BinaryAmp; 3162 3163 case OO_PlusPlus: 3164 case OO_MinusMinus: 3165 // C++ [over.built]p3: 3166 // 3167 // For every pair (T, VQ), where T is an arithmetic type, and VQ 3168 // is either volatile or empty, there exist candidate operator 3169 // functions of the form 3170 // 3171 // VQ T& operator++(VQ T&); 3172 // T operator++(VQ T&, int); 3173 // 3174 // C++ [over.built]p4: 3175 // 3176 // For every pair (T, VQ), where T is an arithmetic type other 3177 // than bool, and VQ is either volatile or empty, there exist 3178 // candidate operator functions of the form 3179 // 3180 // VQ T& operator--(VQ T&); 3181 // T operator--(VQ T&, int); 3182 for (unsigned Arith = (Op == OO_PlusPlus? 0 : 1); 3183 Arith < NumArithmeticTypes; ++Arith) { 3184 QualType ArithTy = ArithmeticTypes[Arith]; 3185 QualType ParamTypes[2] 3186 = { Context.getLValueReferenceType(ArithTy), Context.IntTy }; 3187 3188 // Non-volatile version. 3189 if (NumArgs == 1) 3190 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3191 else 3192 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 3193 3194 // Volatile version 3195 ParamTypes[0] 3196 = Context.getLValueReferenceType(Context.getVolatileType(ArithTy)); 3197 if (NumArgs == 1) 3198 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3199 else 3200 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 3201 } 3202 3203 // C++ [over.built]p5: 3204 // 3205 // For every pair (T, VQ), where T is a cv-qualified or 3206 // cv-unqualified object type, and VQ is either volatile or 3207 // empty, there exist candidate operator functions of the form 3208 // 3209 // T*VQ& operator++(T*VQ&); 3210 // T*VQ& operator--(T*VQ&); 3211 // T* operator++(T*VQ&, int); 3212 // T* operator--(T*VQ&, int); 3213 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3214 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3215 // Skip pointer types that aren't pointers to object types. 3216 if (!(*Ptr)->getAs<PointerType>()->getPointeeType()->isObjectType()) 3217 continue; 3218 3219 QualType ParamTypes[2] = { 3220 Context.getLValueReferenceType(*Ptr), Context.IntTy 3221 }; 3222 3223 // Without volatile 3224 if (NumArgs == 1) 3225 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3226 else 3227 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3228 3229 if (!Context.getCanonicalType(*Ptr).isVolatileQualified()) { 3230 // With volatile 3231 ParamTypes[0] 3232 = Context.getLValueReferenceType(Context.getVolatileType(*Ptr)); 3233 if (NumArgs == 1) 3234 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3235 else 3236 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3237 } 3238 } 3239 break; 3240 3241 UnaryStar: 3242 // C++ [over.built]p6: 3243 // For every cv-qualified or cv-unqualified object type T, there 3244 // exist candidate operator functions of the form 3245 // 3246 // T& operator*(T*); 3247 // 3248 // C++ [over.built]p7: 3249 // For every function type T, there exist candidate operator 3250 // functions of the form 3251 // T& operator*(T*); 3252 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3253 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3254 QualType ParamTy = *Ptr; 3255 QualType PointeeTy = ParamTy->getAs<PointerType>()->getPointeeType(); 3256 AddBuiltinCandidate(Context.getLValueReferenceType(PointeeTy), 3257 &ParamTy, Args, 1, CandidateSet); 3258 } 3259 break; 3260 3261 UnaryPlus: 3262 // C++ [over.built]p8: 3263 // For every type T, there exist candidate operator functions of 3264 // the form 3265 // 3266 // T* operator+(T*); 3267 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3268 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3269 QualType ParamTy = *Ptr; 3270 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet); 3271 } 3272 3273 // Fall through 3274 3275 UnaryMinus: 3276 // C++ [over.built]p9: 3277 // For every promoted arithmetic type T, there exist candidate 3278 // operator functions of the form 3279 // 3280 // T operator+(T); 3281 // T operator-(T); 3282 for (unsigned Arith = FirstPromotedArithmeticType; 3283 Arith < LastPromotedArithmeticType; ++Arith) { 3284 QualType ArithTy = ArithmeticTypes[Arith]; 3285 AddBuiltinCandidate(ArithTy, &ArithTy, Args, 1, CandidateSet); 3286 } 3287 break; 3288 3289 case OO_Tilde: 3290 // C++ [over.built]p10: 3291 // For every promoted integral type T, there exist candidate 3292 // operator functions of the form 3293 // 3294 // T operator~(T); 3295 for (unsigned Int = FirstPromotedIntegralType; 3296 Int < LastPromotedIntegralType; ++Int) { 3297 QualType IntTy = ArithmeticTypes[Int]; 3298 AddBuiltinCandidate(IntTy, &IntTy, Args, 1, CandidateSet); 3299 } 3300 break; 3301 3302 case OO_New: 3303 case OO_Delete: 3304 case OO_Array_New: 3305 case OO_Array_Delete: 3306 case OO_Call: 3307 assert(false && "Special operators don't use AddBuiltinOperatorCandidates"); 3308 break; 3309 3310 case OO_Comma: 3311 UnaryAmp: 3312 case OO_Arrow: 3313 // C++ [over.match.oper]p3: 3314 // -- For the operator ',', the unary operator '&', or the 3315 // operator '->', the built-in candidates set is empty. 3316 break; 3317 3318 case OO_EqualEqual: 3319 case OO_ExclaimEqual: 3320 // C++ [over.match.oper]p16: 3321 // For every pointer to member type T, there exist candidate operator 3322 // functions of the form 3323 // 3324 // bool operator==(T,T); 3325 // bool operator!=(T,T); 3326 for (BuiltinCandidateTypeSet::iterator 3327 MemPtr = CandidateTypes.member_pointer_begin(), 3328 MemPtrEnd = CandidateTypes.member_pointer_end(); 3329 MemPtr != MemPtrEnd; 3330 ++MemPtr) { 3331 QualType ParamTypes[2] = { *MemPtr, *MemPtr }; 3332 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 3333 } 3334 3335 // Fall through 3336 3337 case OO_Less: 3338 case OO_Greater: 3339 case OO_LessEqual: 3340 case OO_GreaterEqual: 3341 // C++ [over.built]p15: 3342 // 3343 // For every pointer or enumeration type T, there exist 3344 // candidate operator functions of the form 3345 // 3346 // bool operator<(T, T); 3347 // bool operator>(T, T); 3348 // bool operator<=(T, T); 3349 // bool operator>=(T, T); 3350 // bool operator==(T, T); 3351 // bool operator!=(T, T); 3352 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3353 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3354 QualType ParamTypes[2] = { *Ptr, *Ptr }; 3355 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 3356 } 3357 for (BuiltinCandidateTypeSet::iterator Enum 3358 = CandidateTypes.enumeration_begin(); 3359 Enum != CandidateTypes.enumeration_end(); ++Enum) { 3360 QualType ParamTypes[2] = { *Enum, *Enum }; 3361 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 3362 } 3363 3364 // Fall through. 3365 isComparison = true; 3366 3367 BinaryPlus: 3368 BinaryMinus: 3369 if (!isComparison) { 3370 // We didn't fall through, so we must have OO_Plus or OO_Minus. 3371 3372 // C++ [over.built]p13: 3373 // 3374 // For every cv-qualified or cv-unqualified object type T 3375 // there exist candidate operator functions of the form 3376 // 3377 // T* operator+(T*, ptrdiff_t); 3378 // T& operator[](T*, ptrdiff_t); [BELOW] 3379 // T* operator-(T*, ptrdiff_t); 3380 // T* operator+(ptrdiff_t, T*); 3381 // T& operator[](ptrdiff_t, T*); [BELOW] 3382 // 3383 // C++ [over.built]p14: 3384 // 3385 // For every T, where T is a pointer to object type, there 3386 // exist candidate operator functions of the form 3387 // 3388 // ptrdiff_t operator-(T, T); 3389 for (BuiltinCandidateTypeSet::iterator Ptr 3390 = CandidateTypes.pointer_begin(); 3391 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3392 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 3393 3394 // operator+(T*, ptrdiff_t) or operator-(T*, ptrdiff_t) 3395 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3396 3397 if (Op == OO_Plus) { 3398 // T* operator+(ptrdiff_t, T*); 3399 ParamTypes[0] = ParamTypes[1]; 3400 ParamTypes[1] = *Ptr; 3401 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3402 } else { 3403 // ptrdiff_t operator-(T, T); 3404 ParamTypes[1] = *Ptr; 3405 AddBuiltinCandidate(Context.getPointerDiffType(), ParamTypes, 3406 Args, 2, CandidateSet); 3407 } 3408 } 3409 } 3410 // Fall through 3411 3412 case OO_Slash: 3413 BinaryStar: 3414 Conditional: 3415 // C++ [over.built]p12: 3416 // 3417 // For every pair of promoted arithmetic types L and R, there 3418 // exist candidate operator functions of the form 3419 // 3420 // LR operator*(L, R); 3421 // LR operator/(L, R); 3422 // LR operator+(L, R); 3423 // LR operator-(L, R); 3424 // bool operator<(L, R); 3425 // bool operator>(L, R); 3426 // bool operator<=(L, R); 3427 // bool operator>=(L, R); 3428 // bool operator==(L, R); 3429 // bool operator!=(L, R); 3430 // 3431 // where LR is the result of the usual arithmetic conversions 3432 // between types L and R. 3433 // 3434 // C++ [over.built]p24: 3435 // 3436 // For every pair of promoted arithmetic types L and R, there exist 3437 // candidate operator functions of the form 3438 // 3439 // LR operator?(bool, L, R); 3440 // 3441 // where LR is the result of the usual arithmetic conversions 3442 // between types L and R. 3443 // Our candidates ignore the first parameter. 3444 for (unsigned Left = FirstPromotedArithmeticType; 3445 Left < LastPromotedArithmeticType; ++Left) { 3446 for (unsigned Right = FirstPromotedArithmeticType; 3447 Right < LastPromotedArithmeticType; ++Right) { 3448 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 3449 QualType Result 3450 = isComparison 3451 ? Context.BoolTy 3452 : Context.UsualArithmeticConversionsType(LandR[0], LandR[1]); 3453 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 3454 } 3455 } 3456 break; 3457 3458 case OO_Percent: 3459 BinaryAmp: 3460 case OO_Caret: 3461 case OO_Pipe: 3462 case OO_LessLess: 3463 case OO_GreaterGreater: 3464 // C++ [over.built]p17: 3465 // 3466 // For every pair of promoted integral types L and R, there 3467 // exist candidate operator functions of the form 3468 // 3469 // LR operator%(L, R); 3470 // LR operator&(L, R); 3471 // LR operator^(L, R); 3472 // LR operator|(L, R); 3473 // L operator<<(L, R); 3474 // L operator>>(L, R); 3475 // 3476 // where LR is the result of the usual arithmetic conversions 3477 // between types L and R. 3478 for (unsigned Left = FirstPromotedIntegralType; 3479 Left < LastPromotedIntegralType; ++Left) { 3480 for (unsigned Right = FirstPromotedIntegralType; 3481 Right < LastPromotedIntegralType; ++Right) { 3482 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 3483 QualType Result = (Op == OO_LessLess || Op == OO_GreaterGreater) 3484 ? LandR[0] 3485 : Context.UsualArithmeticConversionsType(LandR[0], LandR[1]); 3486 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 3487 } 3488 } 3489 break; 3490 3491 case OO_Equal: 3492 // C++ [over.built]p20: 3493 // 3494 // For every pair (T, VQ), where T is an enumeration or 3495 // pointer to member type and VQ is either volatile or 3496 // empty, there exist candidate operator functions of the form 3497 // 3498 // VQ T& operator=(VQ T&, T); 3499 for (BuiltinCandidateTypeSet::iterator 3500 Enum = CandidateTypes.enumeration_begin(), 3501 EnumEnd = CandidateTypes.enumeration_end(); 3502 Enum != EnumEnd; ++Enum) 3503 AddBuiltinAssignmentOperatorCandidates(*this, *Enum, Args, 2, 3504 CandidateSet); 3505 for (BuiltinCandidateTypeSet::iterator 3506 MemPtr = CandidateTypes.member_pointer_begin(), 3507 MemPtrEnd = CandidateTypes.member_pointer_end(); 3508 MemPtr != MemPtrEnd; ++MemPtr) 3509 AddBuiltinAssignmentOperatorCandidates(*this, *MemPtr, Args, 2, 3510 CandidateSet); 3511 // Fall through. 3512 3513 case OO_PlusEqual: 3514 case OO_MinusEqual: 3515 // C++ [over.built]p19: 3516 // 3517 // For every pair (T, VQ), where T is any type and VQ is either 3518 // volatile or empty, there exist candidate operator functions 3519 // of the form 3520 // 3521 // T*VQ& operator=(T*VQ&, T*); 3522 // 3523 // C++ [over.built]p21: 3524 // 3525 // For every pair (T, VQ), where T is a cv-qualified or 3526 // cv-unqualified object type and VQ is either volatile or 3527 // empty, there exist candidate operator functions of the form 3528 // 3529 // T*VQ& operator+=(T*VQ&, ptrdiff_t); 3530 // T*VQ& operator-=(T*VQ&, ptrdiff_t); 3531 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3532 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3533 QualType ParamTypes[2]; 3534 ParamTypes[1] = (Op == OO_Equal)? *Ptr : Context.getPointerDiffType(); 3535 3536 // non-volatile version 3537 ParamTypes[0] = Context.getLValueReferenceType(*Ptr); 3538 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3539 /*IsAssigmentOperator=*/Op == OO_Equal); 3540 3541 if (!Context.getCanonicalType(*Ptr).isVolatileQualified()) { 3542 // volatile version 3543 ParamTypes[0] 3544 = Context.getLValueReferenceType(Context.getVolatileType(*Ptr)); 3545 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3546 /*IsAssigmentOperator=*/Op == OO_Equal); 3547 } 3548 } 3549 // Fall through. 3550 3551 case OO_StarEqual: 3552 case OO_SlashEqual: 3553 // C++ [over.built]p18: 3554 // 3555 // For every triple (L, VQ, R), where L is an arithmetic type, 3556 // VQ is either volatile or empty, and R is a promoted 3557 // arithmetic type, there exist candidate operator functions of 3558 // the form 3559 // 3560 // VQ L& operator=(VQ L&, R); 3561 // VQ L& operator*=(VQ L&, R); 3562 // VQ L& operator/=(VQ L&, R); 3563 // VQ L& operator+=(VQ L&, R); 3564 // VQ L& operator-=(VQ L&, R); 3565 for (unsigned Left = 0; Left < NumArithmeticTypes; ++Left) { 3566 for (unsigned Right = FirstPromotedArithmeticType; 3567 Right < LastPromotedArithmeticType; ++Right) { 3568 QualType ParamTypes[2]; 3569 ParamTypes[1] = ArithmeticTypes[Right]; 3570 3571 // Add this built-in operator as a candidate (VQ is empty). 3572 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 3573 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3574 /*IsAssigmentOperator=*/Op == OO_Equal); 3575 3576 // Add this built-in operator as a candidate (VQ is 'volatile'). 3577 ParamTypes[0] = Context.getVolatileType(ArithmeticTypes[Left]); 3578 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 3579 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3580 /*IsAssigmentOperator=*/Op == OO_Equal); 3581 } 3582 } 3583 break; 3584 3585 case OO_PercentEqual: 3586 case OO_LessLessEqual: 3587 case OO_GreaterGreaterEqual: 3588 case OO_AmpEqual: 3589 case OO_CaretEqual: 3590 case OO_PipeEqual: 3591 // C++ [over.built]p22: 3592 // 3593 // For every triple (L, VQ, R), where L is an integral type, VQ 3594 // is either volatile or empty, and R is a promoted integral 3595 // type, there exist candidate operator functions of the form 3596 // 3597 // VQ L& operator%=(VQ L&, R); 3598 // VQ L& operator<<=(VQ L&, R); 3599 // VQ L& operator>>=(VQ L&, R); 3600 // VQ L& operator&=(VQ L&, R); 3601 // VQ L& operator^=(VQ L&, R); 3602 // VQ L& operator|=(VQ L&, R); 3603 for (unsigned Left = FirstIntegralType; Left < LastIntegralType; ++Left) { 3604 for (unsigned Right = FirstPromotedIntegralType; 3605 Right < LastPromotedIntegralType; ++Right) { 3606 QualType ParamTypes[2]; 3607 ParamTypes[1] = ArithmeticTypes[Right]; 3608 3609 // Add this built-in operator as a candidate (VQ is empty). 3610 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 3611 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 3612 3613 // Add this built-in operator as a candidate (VQ is 'volatile'). 3614 ParamTypes[0] = ArithmeticTypes[Left]; 3615 ParamTypes[0] = Context.getVolatileType(ParamTypes[0]); 3616 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 3617 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 3618 } 3619 } 3620 break; 3621 3622 case OO_Exclaim: { 3623 // C++ [over.operator]p23: 3624 // 3625 // There also exist candidate operator functions of the form 3626 // 3627 // bool operator!(bool); 3628 // bool operator&&(bool, bool); [BELOW] 3629 // bool operator||(bool, bool); [BELOW] 3630 QualType ParamTy = Context.BoolTy; 3631 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet, 3632 /*IsAssignmentOperator=*/false, 3633 /*NumContextualBoolArguments=*/1); 3634 break; 3635 } 3636 3637 case OO_AmpAmp: 3638 case OO_PipePipe: { 3639 // C++ [over.operator]p23: 3640 // 3641 // There also exist candidate operator functions of the form 3642 // 3643 // bool operator!(bool); [ABOVE] 3644 // bool operator&&(bool, bool); 3645 // bool operator||(bool, bool); 3646 QualType ParamTypes[2] = { Context.BoolTy, Context.BoolTy }; 3647 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet, 3648 /*IsAssignmentOperator=*/false, 3649 /*NumContextualBoolArguments=*/2); 3650 break; 3651 } 3652 3653 case OO_Subscript: 3654 // C++ [over.built]p13: 3655 // 3656 // For every cv-qualified or cv-unqualified object type T there 3657 // exist candidate operator functions of the form 3658 // 3659 // T* operator+(T*, ptrdiff_t); [ABOVE] 3660 // T& operator[](T*, ptrdiff_t); 3661 // T* operator-(T*, ptrdiff_t); [ABOVE] 3662 // T* operator+(ptrdiff_t, T*); [ABOVE] 3663 // T& operator[](ptrdiff_t, T*); 3664 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3665 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3666 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 3667 QualType PointeeType = (*Ptr)->getAs<PointerType>()->getPointeeType(); 3668 QualType ResultTy = Context.getLValueReferenceType(PointeeType); 3669 3670 // T& operator[](T*, ptrdiff_t) 3671 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 3672 3673 // T& operator[](ptrdiff_t, T*); 3674 ParamTypes[0] = ParamTypes[1]; 3675 ParamTypes[1] = *Ptr; 3676 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 3677 } 3678 break; 3679 3680 case OO_ArrowStar: 3681 // FIXME: No support for pointer-to-members yet. 3682 break; 3683 3684 case OO_Conditional: 3685 // Note that we don't consider the first argument, since it has been 3686 // contextually converted to bool long ago. The candidates below are 3687 // therefore added as binary. 3688 // 3689 // C++ [over.built]p24: 3690 // For every type T, where T is a pointer or pointer-to-member type, 3691 // there exist candidate operator functions of the form 3692 // 3693 // T operator?(bool, T, T); 3694 // 3695 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(), 3696 E = CandidateTypes.pointer_end(); Ptr != E; ++Ptr) { 3697 QualType ParamTypes[2] = { *Ptr, *Ptr }; 3698 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3699 } 3700 for (BuiltinCandidateTypeSet::iterator Ptr = 3701 CandidateTypes.member_pointer_begin(), 3702 E = CandidateTypes.member_pointer_end(); Ptr != E; ++Ptr) { 3703 QualType ParamTypes[2] = { *Ptr, *Ptr }; 3704 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3705 } 3706 goto Conditional; 3707 } 3708} 3709 3710/// \brief Add function candidates found via argument-dependent lookup 3711/// to the set of overloading candidates. 3712/// 3713/// This routine performs argument-dependent name lookup based on the 3714/// given function name (which may also be an operator name) and adds 3715/// all of the overload candidates found by ADL to the overload 3716/// candidate set (C++ [basic.lookup.argdep]). 3717void 3718Sema::AddArgumentDependentLookupCandidates(DeclarationName Name, 3719 Expr **Args, unsigned NumArgs, 3720 bool HasExplicitTemplateArgs, 3721 const TemplateArgument *ExplicitTemplateArgs, 3722 unsigned NumExplicitTemplateArgs, 3723 OverloadCandidateSet& CandidateSet, 3724 bool PartialOverloading) { 3725 FunctionSet Functions; 3726 3727 // FIXME: Should we be trafficking in canonical function decls throughout? 3728 3729 // Record all of the function candidates that we've already 3730 // added to the overload set, so that we don't add those same 3731 // candidates a second time. 3732 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 3733 CandEnd = CandidateSet.end(); 3734 Cand != CandEnd; ++Cand) 3735 if (Cand->Function) { 3736 Functions.insert(Cand->Function); 3737 if (FunctionTemplateDecl *FunTmpl = Cand->Function->getPrimaryTemplate()) 3738 Functions.insert(FunTmpl); 3739 } 3740 3741 // FIXME: Pass in the explicit template arguments? 3742 ArgumentDependentLookup(Name, Args, NumArgs, Functions); 3743 3744 // Erase all of the candidates we already knew about. 3745 // FIXME: This is suboptimal. Is there a better way? 3746 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 3747 CandEnd = CandidateSet.end(); 3748 Cand != CandEnd; ++Cand) 3749 if (Cand->Function) { 3750 Functions.erase(Cand->Function); 3751 if (FunctionTemplateDecl *FunTmpl = Cand->Function->getPrimaryTemplate()) 3752 Functions.erase(FunTmpl); 3753 } 3754 3755 // For each of the ADL candidates we found, add it to the overload 3756 // set. 3757 for (FunctionSet::iterator Func = Functions.begin(), 3758 FuncEnd = Functions.end(); 3759 Func != FuncEnd; ++Func) { 3760 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*Func)) { 3761 if (HasExplicitTemplateArgs) 3762 continue; 3763 3764 AddOverloadCandidate(FD, Args, NumArgs, CandidateSet, 3765 false, false, PartialOverloading); 3766 } else 3767 AddTemplateOverloadCandidate(cast<FunctionTemplateDecl>(*Func), 3768 HasExplicitTemplateArgs, 3769 ExplicitTemplateArgs, 3770 NumExplicitTemplateArgs, 3771 Args, NumArgs, CandidateSet); 3772 } 3773} 3774 3775/// isBetterOverloadCandidate - Determines whether the first overload 3776/// candidate is a better candidate than the second (C++ 13.3.3p1). 3777bool 3778Sema::isBetterOverloadCandidate(const OverloadCandidate& Cand1, 3779 const OverloadCandidate& Cand2) { 3780 // Define viable functions to be better candidates than non-viable 3781 // functions. 3782 if (!Cand2.Viable) 3783 return Cand1.Viable; 3784 else if (!Cand1.Viable) 3785 return false; 3786 3787 // C++ [over.match.best]p1: 3788 // 3789 // -- if F is a static member function, ICS1(F) is defined such 3790 // that ICS1(F) is neither better nor worse than ICS1(G) for 3791 // any function G, and, symmetrically, ICS1(G) is neither 3792 // better nor worse than ICS1(F). 3793 unsigned StartArg = 0; 3794 if (Cand1.IgnoreObjectArgument || Cand2.IgnoreObjectArgument) 3795 StartArg = 1; 3796 3797 // C++ [over.match.best]p1: 3798 // A viable function F1 is defined to be a better function than another 3799 // viable function F2 if for all arguments i, ICSi(F1) is not a worse 3800 // conversion sequence than ICSi(F2), and then... 3801 unsigned NumArgs = Cand1.Conversions.size(); 3802 assert(Cand2.Conversions.size() == NumArgs && "Overload candidate mismatch"); 3803 bool HasBetterConversion = false; 3804 for (unsigned ArgIdx = StartArg; ArgIdx < NumArgs; ++ArgIdx) { 3805 switch (CompareImplicitConversionSequences(Cand1.Conversions[ArgIdx], 3806 Cand2.Conversions[ArgIdx])) { 3807 case ImplicitConversionSequence::Better: 3808 // Cand1 has a better conversion sequence. 3809 HasBetterConversion = true; 3810 break; 3811 3812 case ImplicitConversionSequence::Worse: 3813 // Cand1 can't be better than Cand2. 3814 return false; 3815 3816 case ImplicitConversionSequence::Indistinguishable: 3817 // Do nothing. 3818 break; 3819 } 3820 } 3821 3822 // -- for some argument j, ICSj(F1) is a better conversion sequence than 3823 // ICSj(F2), or, if not that, 3824 if (HasBetterConversion) 3825 return true; 3826 3827 // - F1 is a non-template function and F2 is a function template 3828 // specialization, or, if not that, 3829 if (Cand1.Function && !Cand1.Function->getPrimaryTemplate() && 3830 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 3831 return true; 3832 3833 // -- F1 and F2 are function template specializations, and the function 3834 // template for F1 is more specialized than the template for F2 3835 // according to the partial ordering rules described in 14.5.5.2, or, 3836 // if not that, 3837 if (Cand1.Function && Cand1.Function->getPrimaryTemplate() && 3838 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 3839 if (FunctionTemplateDecl *BetterTemplate 3840 = getMoreSpecializedTemplate(Cand1.Function->getPrimaryTemplate(), 3841 Cand2.Function->getPrimaryTemplate(), 3842 isa<CXXConversionDecl>(Cand1.Function)? TPOC_Conversion 3843 : TPOC_Call)) 3844 return BetterTemplate == Cand1.Function->getPrimaryTemplate(); 3845 3846 // -- the context is an initialization by user-defined conversion 3847 // (see 8.5, 13.3.1.5) and the standard conversion sequence 3848 // from the return type of F1 to the destination type (i.e., 3849 // the type of the entity being initialized) is a better 3850 // conversion sequence than the standard conversion sequence 3851 // from the return type of F2 to the destination type. 3852 if (Cand1.Function && Cand2.Function && 3853 isa<CXXConversionDecl>(Cand1.Function) && 3854 isa<CXXConversionDecl>(Cand2.Function)) { 3855 switch (CompareStandardConversionSequences(Cand1.FinalConversion, 3856 Cand2.FinalConversion)) { 3857 case ImplicitConversionSequence::Better: 3858 // Cand1 has a better conversion sequence. 3859 return true; 3860 3861 case ImplicitConversionSequence::Worse: 3862 // Cand1 can't be better than Cand2. 3863 return false; 3864 3865 case ImplicitConversionSequence::Indistinguishable: 3866 // Do nothing 3867 break; 3868 } 3869 } 3870 3871 return false; 3872} 3873 3874/// \brief Computes the best viable function (C++ 13.3.3) 3875/// within an overload candidate set. 3876/// 3877/// \param CandidateSet the set of candidate functions. 3878/// 3879/// \param Loc the location of the function name (or operator symbol) for 3880/// which overload resolution occurs. 3881/// 3882/// \param Best f overload resolution was successful or found a deleted 3883/// function, Best points to the candidate function found. 3884/// 3885/// \returns The result of overload resolution. 3886Sema::OverloadingResult 3887Sema::BestViableFunction(OverloadCandidateSet& CandidateSet, 3888 SourceLocation Loc, 3889 OverloadCandidateSet::iterator& Best) { 3890 // Find the best viable function. 3891 Best = CandidateSet.end(); 3892 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 3893 Cand != CandidateSet.end(); ++Cand) { 3894 if (Cand->Viable) { 3895 if (Best == CandidateSet.end() || isBetterOverloadCandidate(*Cand, *Best)) 3896 Best = Cand; 3897 } 3898 } 3899 3900 // If we didn't find any viable functions, abort. 3901 if (Best == CandidateSet.end()) 3902 return OR_No_Viable_Function; 3903 3904 // Make sure that this function is better than every other viable 3905 // function. If not, we have an ambiguity. 3906 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 3907 Cand != CandidateSet.end(); ++Cand) { 3908 if (Cand->Viable && 3909 Cand != Best && 3910 !isBetterOverloadCandidate(*Best, *Cand)) { 3911 Best = CandidateSet.end(); 3912 return OR_Ambiguous; 3913 } 3914 } 3915 3916 // Best is the best viable function. 3917 if (Best->Function && 3918 (Best->Function->isDeleted() || 3919 Best->Function->getAttr<UnavailableAttr>())) 3920 return OR_Deleted; 3921 3922 // C++ [basic.def.odr]p2: 3923 // An overloaded function is used if it is selected by overload resolution 3924 // when referred to from a potentially-evaluated expression. [Note: this 3925 // covers calls to named functions (5.2.2), operator overloading 3926 // (clause 13), user-defined conversions (12.3.2), allocation function for 3927 // placement new (5.3.4), as well as non-default initialization (8.5). 3928 if (Best->Function) 3929 MarkDeclarationReferenced(Loc, Best->Function); 3930 return OR_Success; 3931} 3932 3933/// PrintOverloadCandidates - When overload resolution fails, prints 3934/// diagnostic messages containing the candidates in the candidate 3935/// set. If OnlyViable is true, only viable candidates will be printed. 3936void 3937Sema::PrintOverloadCandidates(OverloadCandidateSet& CandidateSet, 3938 bool OnlyViable) { 3939 OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 3940 LastCand = CandidateSet.end(); 3941 for (; Cand != LastCand; ++Cand) { 3942 if (Cand->Viable || !OnlyViable) { 3943 if (Cand->Function) { 3944 if (Cand->Function->isDeleted() || 3945 Cand->Function->getAttr<UnavailableAttr>()) { 3946 // Deleted or "unavailable" function. 3947 Diag(Cand->Function->getLocation(), diag::err_ovl_candidate_deleted) 3948 << Cand->Function->isDeleted(); 3949 } else if (FunctionTemplateDecl *FunTmpl 3950 = Cand->Function->getPrimaryTemplate()) { 3951 // Function template specialization 3952 // FIXME: Give a better reason! 3953 Diag(Cand->Function->getLocation(), diag::err_ovl_template_candidate) 3954 << getTemplateArgumentBindingsText(FunTmpl->getTemplateParameters(), 3955 *Cand->Function->getTemplateSpecializationArgs()); 3956 } else { 3957 // Normal function 3958 bool errReported = false; 3959 if (!Cand->Viable && Cand->Conversions.size() > 0) { 3960 for (int i = Cand->Conversions.size()-1; i >= 0; i--) { 3961 const ImplicitConversionSequence &Conversion = 3962 Cand->Conversions[i]; 3963 if ((Conversion.ConversionKind != 3964 ImplicitConversionSequence::BadConversion) || 3965 Conversion.ConversionFunctionSet.size() == 0) 3966 continue; 3967 Diag(Cand->Function->getLocation(), 3968 diag::err_ovl_candidate_not_viable) << (i+1); 3969 errReported = true; 3970 for (int j = Conversion.ConversionFunctionSet.size()-1; 3971 j >= 0; j--) { 3972 FunctionDecl *Func = Conversion.ConversionFunctionSet[j]; 3973 Diag(Func->getLocation(), diag::err_ovl_candidate); 3974 } 3975 } 3976 } 3977 if (!errReported) 3978 Diag(Cand->Function->getLocation(), diag::err_ovl_candidate); 3979 } 3980 } else if (Cand->IsSurrogate) { 3981 // Desugar the type of the surrogate down to a function type, 3982 // retaining as many typedefs as possible while still showing 3983 // the function type (and, therefore, its parameter types). 3984 QualType FnType = Cand->Surrogate->getConversionType(); 3985 bool isLValueReference = false; 3986 bool isRValueReference = false; 3987 bool isPointer = false; 3988 if (const LValueReferenceType *FnTypeRef = 3989 FnType->getAs<LValueReferenceType>()) { 3990 FnType = FnTypeRef->getPointeeType(); 3991 isLValueReference = true; 3992 } else if (const RValueReferenceType *FnTypeRef = 3993 FnType->getAs<RValueReferenceType>()) { 3994 FnType = FnTypeRef->getPointeeType(); 3995 isRValueReference = true; 3996 } 3997 if (const PointerType *FnTypePtr = FnType->getAs<PointerType>()) { 3998 FnType = FnTypePtr->getPointeeType(); 3999 isPointer = true; 4000 } 4001 // Desugar down to a function type. 4002 FnType = QualType(FnType->getAs<FunctionType>(), 0); 4003 // Reconstruct the pointer/reference as appropriate. 4004 if (isPointer) FnType = Context.getPointerType(FnType); 4005 if (isRValueReference) FnType = Context.getRValueReferenceType(FnType); 4006 if (isLValueReference) FnType = Context.getLValueReferenceType(FnType); 4007 4008 Diag(Cand->Surrogate->getLocation(), diag::err_ovl_surrogate_cand) 4009 << FnType; 4010 } else if (OnlyViable) { 4011 // FIXME: We need to get the identifier in here 4012 // FIXME: Do we want the error message to point at the operator? 4013 // (built-ins won't have a location) 4014 // FIXME: can we get some kind of stable location for this? 4015 QualType FnType 4016 = Context.getFunctionType(Cand->BuiltinTypes.ResultTy, 4017 Cand->BuiltinTypes.ParamTypes, 4018 Cand->Conversions.size(), 4019 false, 0); 4020 4021 Diag(SourceLocation(), diag::err_ovl_builtin_candidate) << FnType; 4022 } 4023 } 4024 } 4025} 4026 4027/// ResolveAddressOfOverloadedFunction - Try to resolve the address of 4028/// an overloaded function (C++ [over.over]), where @p From is an 4029/// expression with overloaded function type and @p ToType is the type 4030/// we're trying to resolve to. For example: 4031/// 4032/// @code 4033/// int f(double); 4034/// int f(int); 4035/// 4036/// int (*pfd)(double) = f; // selects f(double) 4037/// @endcode 4038/// 4039/// This routine returns the resulting FunctionDecl if it could be 4040/// resolved, and NULL otherwise. When @p Complain is true, this 4041/// routine will emit diagnostics if there is an error. 4042FunctionDecl * 4043Sema::ResolveAddressOfOverloadedFunction(Expr *From, QualType ToType, 4044 bool Complain) { 4045 QualType FunctionType = ToType; 4046 bool IsMember = false; 4047 if (const PointerType *ToTypePtr = ToType->getAs<PointerType>()) 4048 FunctionType = ToTypePtr->getPointeeType(); 4049 else if (const ReferenceType *ToTypeRef = ToType->getAs<ReferenceType>()) 4050 FunctionType = ToTypeRef->getPointeeType(); 4051 else if (const MemberPointerType *MemTypePtr = 4052 ToType->getAs<MemberPointerType>()) { 4053 FunctionType = MemTypePtr->getPointeeType(); 4054 IsMember = true; 4055 } 4056 4057 // We only look at pointers or references to functions. 4058 FunctionType = Context.getCanonicalType(FunctionType).getUnqualifiedType(); 4059 if (!FunctionType->isFunctionType()) 4060 return 0; 4061 4062 // Find the actual overloaded function declaration. 4063 OverloadedFunctionDecl *Ovl = 0; 4064 4065 // C++ [over.over]p1: 4066 // [...] [Note: any redundant set of parentheses surrounding the 4067 // overloaded function name is ignored (5.1). ] 4068 Expr *OvlExpr = From->IgnoreParens(); 4069 4070 // C++ [over.over]p1: 4071 // [...] The overloaded function name can be preceded by the & 4072 // operator. 4073 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(OvlExpr)) { 4074 if (UnOp->getOpcode() == UnaryOperator::AddrOf) 4075 OvlExpr = UnOp->getSubExpr()->IgnoreParens(); 4076 } 4077 4078 // Try to dig out the overloaded function. 4079 FunctionTemplateDecl *FunctionTemplate = 0; 4080 if (DeclRefExpr *DR = dyn_cast<DeclRefExpr>(OvlExpr)) { 4081 Ovl = dyn_cast<OverloadedFunctionDecl>(DR->getDecl()); 4082 FunctionTemplate = dyn_cast<FunctionTemplateDecl>(DR->getDecl()); 4083 } 4084 4085 // If there's no overloaded function declaration or function template, 4086 // we're done. 4087 if (!Ovl && !FunctionTemplate) 4088 return 0; 4089 4090 OverloadIterator Fun; 4091 if (Ovl) 4092 Fun = Ovl; 4093 else 4094 Fun = FunctionTemplate; 4095 4096 // Look through all of the overloaded functions, searching for one 4097 // whose type matches exactly. 4098 llvm::SmallPtrSet<FunctionDecl *, 4> Matches; 4099 bool FoundNonTemplateFunction = false; 4100 for (OverloadIterator FunEnd; Fun != FunEnd; ++Fun) { 4101 // C++ [over.over]p3: 4102 // Non-member functions and static member functions match 4103 // targets of type "pointer-to-function" or "reference-to-function." 4104 // Nonstatic member functions match targets of 4105 // type "pointer-to-member-function." 4106 // Note that according to DR 247, the containing class does not matter. 4107 4108 if (FunctionTemplateDecl *FunctionTemplate 4109 = dyn_cast<FunctionTemplateDecl>(*Fun)) { 4110 if (CXXMethodDecl *Method 4111 = dyn_cast<CXXMethodDecl>(FunctionTemplate->getTemplatedDecl())) { 4112 // Skip non-static function templates when converting to pointer, and 4113 // static when converting to member pointer. 4114 if (Method->isStatic() == IsMember) 4115 continue; 4116 } else if (IsMember) 4117 continue; 4118 4119 // C++ [over.over]p2: 4120 // If the name is a function template, template argument deduction is 4121 // done (14.8.2.2), and if the argument deduction succeeds, the 4122 // resulting template argument list is used to generate a single 4123 // function template specialization, which is added to the set of 4124 // overloaded functions considered. 4125 // FIXME: We don't really want to build the specialization here, do we? 4126 FunctionDecl *Specialization = 0; 4127 TemplateDeductionInfo Info(Context); 4128 if (TemplateDeductionResult Result 4129 = DeduceTemplateArguments(FunctionTemplate, /*FIXME*/false, 4130 /*FIXME:*/0, /*FIXME:*/0, 4131 FunctionType, Specialization, Info)) { 4132 // FIXME: make a note of the failed deduction for diagnostics. 4133 (void)Result; 4134 } else { 4135 // FIXME: If the match isn't exact, shouldn't we just drop this as 4136 // a candidate? Find a testcase before changing the code. 4137 assert(FunctionType 4138 == Context.getCanonicalType(Specialization->getType())); 4139 Matches.insert( 4140 cast<FunctionDecl>(Specialization->getCanonicalDecl())); 4141 } 4142 } 4143 4144 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(*Fun)) { 4145 // Skip non-static functions when converting to pointer, and static 4146 // when converting to member pointer. 4147 if (Method->isStatic() == IsMember) 4148 continue; 4149 } else if (IsMember) 4150 continue; 4151 4152 if (FunctionDecl *FunDecl = dyn_cast<FunctionDecl>(*Fun)) { 4153 if (FunctionType == Context.getCanonicalType(FunDecl->getType())) { 4154 Matches.insert(cast<FunctionDecl>(Fun->getCanonicalDecl())); 4155 FoundNonTemplateFunction = true; 4156 } 4157 } 4158 } 4159 4160 // If there were 0 or 1 matches, we're done. 4161 if (Matches.empty()) 4162 return 0; 4163 else if (Matches.size() == 1) 4164 return *Matches.begin(); 4165 4166 // C++ [over.over]p4: 4167 // If more than one function is selected, [...] 4168 typedef llvm::SmallPtrSet<FunctionDecl *, 4>::iterator MatchIter; 4169 if (!FoundNonTemplateFunction) { 4170 // [...] and any given function template specialization F1 is 4171 // eliminated if the set contains a second function template 4172 // specialization whose function template is more specialized 4173 // than the function template of F1 according to the partial 4174 // ordering rules of 14.5.5.2. 4175 4176 // The algorithm specified above is quadratic. We instead use a 4177 // two-pass algorithm (similar to the one used to identify the 4178 // best viable function in an overload set) that identifies the 4179 // best function template (if it exists). 4180 llvm::SmallVector<FunctionDecl *, 8> TemplateMatches(Matches.begin(), 4181 Matches.end()); 4182 return getMostSpecialized(TemplateMatches.data(), TemplateMatches.size(), 4183 TPOC_Other, From->getLocStart(), 4184 PartialDiagnostic(0), 4185 PartialDiagnostic(diag::err_addr_ovl_ambiguous) 4186 << TemplateMatches[0]->getDeclName(), 4187 PartialDiagnostic(diag::err_ovl_template_candidate)); 4188 } 4189 4190 // [...] any function template specializations in the set are 4191 // eliminated if the set also contains a non-template function, [...] 4192 llvm::SmallVector<FunctionDecl *, 4> RemainingMatches; 4193 for (MatchIter M = Matches.begin(), MEnd = Matches.end(); M != MEnd; ++M) 4194 if ((*M)->getPrimaryTemplate() == 0) 4195 RemainingMatches.push_back(*M); 4196 4197 // [...] After such eliminations, if any, there shall remain exactly one 4198 // selected function. 4199 if (RemainingMatches.size() == 1) 4200 return RemainingMatches.front(); 4201 4202 // FIXME: We should probably return the same thing that BestViableFunction 4203 // returns (even if we issue the diagnostics here). 4204 Diag(From->getLocStart(), diag::err_addr_ovl_ambiguous) 4205 << RemainingMatches[0]->getDeclName(); 4206 for (unsigned I = 0, N = RemainingMatches.size(); I != N; ++I) 4207 Diag(RemainingMatches[I]->getLocation(), diag::err_ovl_candidate); 4208 return 0; 4209} 4210 4211/// \brief Add a single candidate to the overload set. 4212static void AddOverloadedCallCandidate(Sema &S, 4213 AnyFunctionDecl Callee, 4214 bool &ArgumentDependentLookup, 4215 bool HasExplicitTemplateArgs, 4216 const TemplateArgument *ExplicitTemplateArgs, 4217 unsigned NumExplicitTemplateArgs, 4218 Expr **Args, unsigned NumArgs, 4219 OverloadCandidateSet &CandidateSet, 4220 bool PartialOverloading) { 4221 if (FunctionDecl *Func = dyn_cast<FunctionDecl>(Callee)) { 4222 assert(!HasExplicitTemplateArgs && "Explicit template arguments?"); 4223 S.AddOverloadCandidate(Func, Args, NumArgs, CandidateSet, false, false, 4224 PartialOverloading); 4225 4226 if (Func->getDeclContext()->isRecord() || 4227 Func->getDeclContext()->isFunctionOrMethod()) 4228 ArgumentDependentLookup = false; 4229 return; 4230 } 4231 4232 FunctionTemplateDecl *FuncTemplate = cast<FunctionTemplateDecl>(Callee); 4233 S.AddTemplateOverloadCandidate(FuncTemplate, HasExplicitTemplateArgs, 4234 ExplicitTemplateArgs, 4235 NumExplicitTemplateArgs, 4236 Args, NumArgs, CandidateSet); 4237 4238 if (FuncTemplate->getDeclContext()->isRecord()) 4239 ArgumentDependentLookup = false; 4240} 4241 4242/// \brief Add the overload candidates named by callee and/or found by argument 4243/// dependent lookup to the given overload set. 4244void Sema::AddOverloadedCallCandidates(NamedDecl *Callee, 4245 DeclarationName &UnqualifiedName, 4246 bool &ArgumentDependentLookup, 4247 bool HasExplicitTemplateArgs, 4248 const TemplateArgument *ExplicitTemplateArgs, 4249 unsigned NumExplicitTemplateArgs, 4250 Expr **Args, unsigned NumArgs, 4251 OverloadCandidateSet &CandidateSet, 4252 bool PartialOverloading) { 4253 // Add the functions denoted by Callee to the set of candidate 4254 // functions. While we're doing so, track whether argument-dependent 4255 // lookup still applies, per: 4256 // 4257 // C++0x [basic.lookup.argdep]p3: 4258 // Let X be the lookup set produced by unqualified lookup (3.4.1) 4259 // and let Y be the lookup set produced by argument dependent 4260 // lookup (defined as follows). If X contains 4261 // 4262 // -- a declaration of a class member, or 4263 // 4264 // -- a block-scope function declaration that is not a 4265 // using-declaration (FIXME: check for using declaration), or 4266 // 4267 // -- a declaration that is neither a function or a function 4268 // template 4269 // 4270 // then Y is empty. 4271 if (!Callee) { 4272 // Nothing to do. 4273 } else if (OverloadedFunctionDecl *Ovl 4274 = dyn_cast<OverloadedFunctionDecl>(Callee)) { 4275 for (OverloadedFunctionDecl::function_iterator Func = Ovl->function_begin(), 4276 FuncEnd = Ovl->function_end(); 4277 Func != FuncEnd; ++Func) 4278 AddOverloadedCallCandidate(*this, *Func, ArgumentDependentLookup, 4279 HasExplicitTemplateArgs, 4280 ExplicitTemplateArgs, NumExplicitTemplateArgs, 4281 Args, NumArgs, CandidateSet, 4282 PartialOverloading); 4283 } else if (isa<FunctionDecl>(Callee) || isa<FunctionTemplateDecl>(Callee)) 4284 AddOverloadedCallCandidate(*this, 4285 AnyFunctionDecl::getFromNamedDecl(Callee), 4286 ArgumentDependentLookup, 4287 HasExplicitTemplateArgs, 4288 ExplicitTemplateArgs, NumExplicitTemplateArgs, 4289 Args, NumArgs, CandidateSet, 4290 PartialOverloading); 4291 // FIXME: assert isa<FunctionDecl> || isa<FunctionTemplateDecl> rather than 4292 // checking dynamically. 4293 4294 if (Callee) 4295 UnqualifiedName = Callee->getDeclName(); 4296 4297 if (ArgumentDependentLookup) 4298 AddArgumentDependentLookupCandidates(UnqualifiedName, Args, NumArgs, 4299 HasExplicitTemplateArgs, 4300 ExplicitTemplateArgs, 4301 NumExplicitTemplateArgs, 4302 CandidateSet, 4303 PartialOverloading); 4304} 4305 4306/// ResolveOverloadedCallFn - Given the call expression that calls Fn 4307/// (which eventually refers to the declaration Func) and the call 4308/// arguments Args/NumArgs, attempt to resolve the function call down 4309/// to a specific function. If overload resolution succeeds, returns 4310/// the function declaration produced by overload 4311/// resolution. Otherwise, emits diagnostics, deletes all of the 4312/// arguments and Fn, and returns NULL. 4313FunctionDecl *Sema::ResolveOverloadedCallFn(Expr *Fn, NamedDecl *Callee, 4314 DeclarationName UnqualifiedName, 4315 bool HasExplicitTemplateArgs, 4316 const TemplateArgument *ExplicitTemplateArgs, 4317 unsigned NumExplicitTemplateArgs, 4318 SourceLocation LParenLoc, 4319 Expr **Args, unsigned NumArgs, 4320 SourceLocation *CommaLocs, 4321 SourceLocation RParenLoc, 4322 bool &ArgumentDependentLookup) { 4323 OverloadCandidateSet CandidateSet; 4324 4325 // Add the functions denoted by Callee to the set of candidate 4326 // functions. 4327 AddOverloadedCallCandidates(Callee, UnqualifiedName, ArgumentDependentLookup, 4328 HasExplicitTemplateArgs, ExplicitTemplateArgs, 4329 NumExplicitTemplateArgs, Args, NumArgs, 4330 CandidateSet); 4331 OverloadCandidateSet::iterator Best; 4332 switch (BestViableFunction(CandidateSet, Fn->getLocStart(), Best)) { 4333 case OR_Success: 4334 return Best->Function; 4335 4336 case OR_No_Viable_Function: 4337 Diag(Fn->getSourceRange().getBegin(), 4338 diag::err_ovl_no_viable_function_in_call) 4339 << UnqualifiedName << Fn->getSourceRange(); 4340 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4341 break; 4342 4343 case OR_Ambiguous: 4344 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_ambiguous_call) 4345 << UnqualifiedName << Fn->getSourceRange(); 4346 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4347 break; 4348 4349 case OR_Deleted: 4350 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_deleted_call) 4351 << Best->Function->isDeleted() 4352 << UnqualifiedName 4353 << Fn->getSourceRange(); 4354 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4355 break; 4356 } 4357 4358 // Overload resolution failed. Destroy all of the subexpressions and 4359 // return NULL. 4360 Fn->Destroy(Context); 4361 for (unsigned Arg = 0; Arg < NumArgs; ++Arg) 4362 Args[Arg]->Destroy(Context); 4363 return 0; 4364} 4365 4366/// \brief Create a unary operation that may resolve to an overloaded 4367/// operator. 4368/// 4369/// \param OpLoc The location of the operator itself (e.g., '*'). 4370/// 4371/// \param OpcIn The UnaryOperator::Opcode that describes this 4372/// operator. 4373/// 4374/// \param Functions The set of non-member functions that will be 4375/// considered by overload resolution. The caller needs to build this 4376/// set based on the context using, e.g., 4377/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 4378/// set should not contain any member functions; those will be added 4379/// by CreateOverloadedUnaryOp(). 4380/// 4381/// \param input The input argument. 4382Sema::OwningExprResult Sema::CreateOverloadedUnaryOp(SourceLocation OpLoc, 4383 unsigned OpcIn, 4384 FunctionSet &Functions, 4385 ExprArg input) { 4386 UnaryOperator::Opcode Opc = static_cast<UnaryOperator::Opcode>(OpcIn); 4387 Expr *Input = (Expr *)input.get(); 4388 4389 OverloadedOperatorKind Op = UnaryOperator::getOverloadedOperator(Opc); 4390 assert(Op != OO_None && "Invalid opcode for overloaded unary operator"); 4391 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 4392 4393 Expr *Args[2] = { Input, 0 }; 4394 unsigned NumArgs = 1; 4395 4396 // For post-increment and post-decrement, add the implicit '0' as 4397 // the second argument, so that we know this is a post-increment or 4398 // post-decrement. 4399 if (Opc == UnaryOperator::PostInc || Opc == UnaryOperator::PostDec) { 4400 llvm::APSInt Zero(Context.getTypeSize(Context.IntTy), false); 4401 Args[1] = new (Context) IntegerLiteral(Zero, Context.IntTy, 4402 SourceLocation()); 4403 NumArgs = 2; 4404 } 4405 4406 if (Input->isTypeDependent()) { 4407 OverloadedFunctionDecl *Overloads 4408 = OverloadedFunctionDecl::Create(Context, CurContext, OpName); 4409 for (FunctionSet::iterator Func = Functions.begin(), 4410 FuncEnd = Functions.end(); 4411 Func != FuncEnd; ++Func) 4412 Overloads->addOverload(*Func); 4413 4414 DeclRefExpr *Fn = new (Context) DeclRefExpr(Overloads, Context.OverloadTy, 4415 OpLoc, false, false); 4416 4417 input.release(); 4418 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 4419 &Args[0], NumArgs, 4420 Context.DependentTy, 4421 OpLoc)); 4422 } 4423 4424 // Build an empty overload set. 4425 OverloadCandidateSet CandidateSet; 4426 4427 // Add the candidates from the given function set. 4428 AddFunctionCandidates(Functions, &Args[0], NumArgs, CandidateSet, false); 4429 4430 // Add operator candidates that are member functions. 4431 AddMemberOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 4432 4433 // Add builtin operator candidates. 4434 AddBuiltinOperatorCandidates(Op, &Args[0], NumArgs, CandidateSet); 4435 4436 // Perform overload resolution. 4437 OverloadCandidateSet::iterator Best; 4438 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 4439 case OR_Success: { 4440 // We found a built-in operator or an overloaded operator. 4441 FunctionDecl *FnDecl = Best->Function; 4442 4443 if (FnDecl) { 4444 // We matched an overloaded operator. Build a call to that 4445 // operator. 4446 4447 // Convert the arguments. 4448 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 4449 if (PerformObjectArgumentInitialization(Input, Method)) 4450 return ExprError(); 4451 } else { 4452 // Convert the arguments. 4453 if (PerformCopyInitialization(Input, 4454 FnDecl->getParamDecl(0)->getType(), 4455 "passing")) 4456 return ExprError(); 4457 } 4458 4459 // Determine the result type 4460 QualType ResultTy 4461 = FnDecl->getType()->getAs<FunctionType>()->getResultType(); 4462 ResultTy = ResultTy.getNonReferenceType(); 4463 4464 // Build the actual expression node. 4465 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 4466 SourceLocation()); 4467 UsualUnaryConversions(FnExpr); 4468 4469 input.release(); 4470 4471 Expr *CE = new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 4472 &Input, 1, ResultTy, OpLoc); 4473 return MaybeBindToTemporary(CE); 4474 } else { 4475 // We matched a built-in operator. Convert the arguments, then 4476 // break out so that we will build the appropriate built-in 4477 // operator node. 4478 if (PerformImplicitConversion(Input, Best->BuiltinTypes.ParamTypes[0], 4479 Best->Conversions[0], "passing")) 4480 return ExprError(); 4481 4482 break; 4483 } 4484 } 4485 4486 case OR_No_Viable_Function: 4487 // No viable function; fall through to handling this as a 4488 // built-in operator, which will produce an error message for us. 4489 break; 4490 4491 case OR_Ambiguous: 4492 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 4493 << UnaryOperator::getOpcodeStr(Opc) 4494 << Input->getSourceRange(); 4495 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4496 return ExprError(); 4497 4498 case OR_Deleted: 4499 Diag(OpLoc, diag::err_ovl_deleted_oper) 4500 << Best->Function->isDeleted() 4501 << UnaryOperator::getOpcodeStr(Opc) 4502 << Input->getSourceRange(); 4503 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4504 return ExprError(); 4505 } 4506 4507 // Either we found no viable overloaded operator or we matched a 4508 // built-in operator. In either case, fall through to trying to 4509 // build a built-in operation. 4510 input.release(); 4511 return CreateBuiltinUnaryOp(OpLoc, Opc, Owned(Input)); 4512} 4513 4514/// \brief Create a binary operation that may resolve to an overloaded 4515/// operator. 4516/// 4517/// \param OpLoc The location of the operator itself (e.g., '+'). 4518/// 4519/// \param OpcIn The BinaryOperator::Opcode that describes this 4520/// operator. 4521/// 4522/// \param Functions The set of non-member functions that will be 4523/// considered by overload resolution. The caller needs to build this 4524/// set based on the context using, e.g., 4525/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 4526/// set should not contain any member functions; those will be added 4527/// by CreateOverloadedBinOp(). 4528/// 4529/// \param LHS Left-hand argument. 4530/// \param RHS Right-hand argument. 4531Sema::OwningExprResult 4532Sema::CreateOverloadedBinOp(SourceLocation OpLoc, 4533 unsigned OpcIn, 4534 FunctionSet &Functions, 4535 Expr *LHS, Expr *RHS) { 4536 Expr *Args[2] = { LHS, RHS }; 4537 LHS=RHS=0; //Please use only Args instead of LHS/RHS couple 4538 4539 BinaryOperator::Opcode Opc = static_cast<BinaryOperator::Opcode>(OpcIn); 4540 OverloadedOperatorKind Op = BinaryOperator::getOverloadedOperator(Opc); 4541 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 4542 4543 // If either side is type-dependent, create an appropriate dependent 4544 // expression. 4545 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 4546 // .* cannot be overloaded. 4547 if (Opc == BinaryOperator::PtrMemD) 4548 return Owned(new (Context) BinaryOperator(Args[0], Args[1], Opc, 4549 Context.DependentTy, OpLoc)); 4550 4551 OverloadedFunctionDecl *Overloads 4552 = OverloadedFunctionDecl::Create(Context, CurContext, OpName); 4553 for (FunctionSet::iterator Func = Functions.begin(), 4554 FuncEnd = Functions.end(); 4555 Func != FuncEnd; ++Func) 4556 Overloads->addOverload(*Func); 4557 4558 DeclRefExpr *Fn = new (Context) DeclRefExpr(Overloads, Context.OverloadTy, 4559 OpLoc, false, false); 4560 4561 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 4562 Args, 2, 4563 Context.DependentTy, 4564 OpLoc)); 4565 } 4566 4567 // If this is the .* operator, which is not overloadable, just 4568 // create a built-in binary operator. 4569 if (Opc == BinaryOperator::PtrMemD) 4570 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 4571 4572 // If this is one of the assignment operators, we only perform 4573 // overload resolution if the left-hand side is a class or 4574 // enumeration type (C++ [expr.ass]p3). 4575 if (Opc >= BinaryOperator::Assign && Opc <= BinaryOperator::OrAssign && 4576 !Args[0]->getType()->isOverloadableType()) 4577 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 4578 4579 // Build an empty overload set. 4580 OverloadCandidateSet CandidateSet; 4581 4582 // Add the candidates from the given function set. 4583 AddFunctionCandidates(Functions, Args, 2, CandidateSet, false); 4584 4585 // Add operator candidates that are member functions. 4586 AddMemberOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 4587 4588 // Add builtin operator candidates. 4589 AddBuiltinOperatorCandidates(Op, Args, 2, CandidateSet); 4590 4591 // Perform overload resolution. 4592 OverloadCandidateSet::iterator Best; 4593 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 4594 case OR_Success: { 4595 // We found a built-in operator or an overloaded operator. 4596 FunctionDecl *FnDecl = Best->Function; 4597 4598 if (FnDecl) { 4599 // We matched an overloaded operator. Build a call to that 4600 // operator. 4601 4602 // Convert the arguments. 4603 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 4604 if (PerformObjectArgumentInitialization(Args[0], Method) || 4605 PerformCopyInitialization(Args[1], FnDecl->getParamDecl(0)->getType(), 4606 "passing")) 4607 return ExprError(); 4608 } else { 4609 // Convert the arguments. 4610 if (PerformCopyInitialization(Args[0], FnDecl->getParamDecl(0)->getType(), 4611 "passing") || 4612 PerformCopyInitialization(Args[1], FnDecl->getParamDecl(1)->getType(), 4613 "passing")) 4614 return ExprError(); 4615 } 4616 4617 // Determine the result type 4618 QualType ResultTy 4619 = FnDecl->getType()->getAs<FunctionType>()->getResultType(); 4620 ResultTy = ResultTy.getNonReferenceType(); 4621 4622 // Build the actual expression node. 4623 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 4624 OpLoc); 4625 UsualUnaryConversions(FnExpr); 4626 4627 Expr *CE = new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 4628 Args, 2, ResultTy, OpLoc); 4629 return MaybeBindToTemporary(CE); 4630 } else { 4631 // We matched a built-in operator. Convert the arguments, then 4632 // break out so that we will build the appropriate built-in 4633 // operator node. 4634 if (PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 4635 Best->Conversions[0], "passing") || 4636 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 4637 Best->Conversions[1], "passing")) 4638 return ExprError(); 4639 4640 break; 4641 } 4642 } 4643 4644 case OR_No_Viable_Function: { 4645 // C++ [over.match.oper]p9: 4646 // If the operator is the operator , [...] and there are no 4647 // viable functions, then the operator is assumed to be the 4648 // built-in operator and interpreted according to clause 5. 4649 if (Opc == BinaryOperator::Comma) 4650 break; 4651 4652 // For class as left operand for assignment or compound assigment operator 4653 // do not fall through to handling in built-in, but report that no overloaded 4654 // assignment operator found 4655 OwningExprResult Result = ExprError(); 4656 if (Args[0]->getType()->isRecordType() && 4657 Opc >= BinaryOperator::Assign && Opc <= BinaryOperator::OrAssign) { 4658 Diag(OpLoc, diag::err_ovl_no_viable_oper) 4659 << BinaryOperator::getOpcodeStr(Opc) 4660 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 4661 } else { 4662 // No viable function; try to create a built-in operation, which will 4663 // produce an error. Then, show the non-viable candidates. 4664 Result = CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 4665 } 4666 assert(Result.isInvalid() && 4667 "C++ binary operator overloading is missing candidates!"); 4668 if (Result.isInvalid()) 4669 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4670 return move(Result); 4671 } 4672 4673 case OR_Ambiguous: 4674 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 4675 << BinaryOperator::getOpcodeStr(Opc) 4676 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 4677 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4678 return ExprError(); 4679 4680 case OR_Deleted: 4681 Diag(OpLoc, diag::err_ovl_deleted_oper) 4682 << Best->Function->isDeleted() 4683 << BinaryOperator::getOpcodeStr(Opc) 4684 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 4685 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4686 return ExprError(); 4687 } 4688 4689 // We matched a built-in operator; build it. 4690 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 4691} 4692 4693/// BuildCallToMemberFunction - Build a call to a member 4694/// function. MemExpr is the expression that refers to the member 4695/// function (and includes the object parameter), Args/NumArgs are the 4696/// arguments to the function call (not including the object 4697/// parameter). The caller needs to validate that the member 4698/// expression refers to a member function or an overloaded member 4699/// function. 4700Sema::ExprResult 4701Sema::BuildCallToMemberFunction(Scope *S, Expr *MemExprE, 4702 SourceLocation LParenLoc, Expr **Args, 4703 unsigned NumArgs, SourceLocation *CommaLocs, 4704 SourceLocation RParenLoc) { 4705 // Dig out the member expression. This holds both the object 4706 // argument and the member function we're referring to. 4707 MemberExpr *MemExpr = 0; 4708 if (ParenExpr *ParenE = dyn_cast<ParenExpr>(MemExprE)) 4709 MemExpr = dyn_cast<MemberExpr>(ParenE->getSubExpr()); 4710 else 4711 MemExpr = dyn_cast<MemberExpr>(MemExprE); 4712 assert(MemExpr && "Building member call without member expression"); 4713 4714 // Extract the object argument. 4715 Expr *ObjectArg = MemExpr->getBase(); 4716 4717 CXXMethodDecl *Method = 0; 4718 if (isa<OverloadedFunctionDecl>(MemExpr->getMemberDecl()) || 4719 isa<FunctionTemplateDecl>(MemExpr->getMemberDecl())) { 4720 // Add overload candidates 4721 OverloadCandidateSet CandidateSet; 4722 DeclarationName DeclName = MemExpr->getMemberDecl()->getDeclName(); 4723 4724 for (OverloadIterator Func(MemExpr->getMemberDecl()), FuncEnd; 4725 Func != FuncEnd; ++Func) { 4726 if ((Method = dyn_cast<CXXMethodDecl>(*Func))) 4727 AddMethodCandidate(Method, ObjectArg, Args, NumArgs, CandidateSet, 4728 /*SuppressUserConversions=*/false); 4729 else 4730 AddMethodTemplateCandidate(cast<FunctionTemplateDecl>(*Func), 4731 MemExpr->hasExplicitTemplateArgumentList(), 4732 MemExpr->getTemplateArgs(), 4733 MemExpr->getNumTemplateArgs(), 4734 ObjectArg, Args, NumArgs, 4735 CandidateSet, 4736 /*SuppressUsedConversions=*/false); 4737 } 4738 4739 OverloadCandidateSet::iterator Best; 4740 switch (BestViableFunction(CandidateSet, MemExpr->getLocStart(), Best)) { 4741 case OR_Success: 4742 Method = cast<CXXMethodDecl>(Best->Function); 4743 break; 4744 4745 case OR_No_Viable_Function: 4746 Diag(MemExpr->getSourceRange().getBegin(), 4747 diag::err_ovl_no_viable_member_function_in_call) 4748 << DeclName << MemExprE->getSourceRange(); 4749 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4750 // FIXME: Leaking incoming expressions! 4751 return true; 4752 4753 case OR_Ambiguous: 4754 Diag(MemExpr->getSourceRange().getBegin(), 4755 diag::err_ovl_ambiguous_member_call) 4756 << DeclName << MemExprE->getSourceRange(); 4757 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4758 // FIXME: Leaking incoming expressions! 4759 return true; 4760 4761 case OR_Deleted: 4762 Diag(MemExpr->getSourceRange().getBegin(), 4763 diag::err_ovl_deleted_member_call) 4764 << Best->Function->isDeleted() 4765 << DeclName << MemExprE->getSourceRange(); 4766 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4767 // FIXME: Leaking incoming expressions! 4768 return true; 4769 } 4770 4771 FixOverloadedFunctionReference(MemExpr, Method); 4772 } else { 4773 Method = dyn_cast<CXXMethodDecl>(MemExpr->getMemberDecl()); 4774 } 4775 4776 assert(Method && "Member call to something that isn't a method?"); 4777 ExprOwningPtr<CXXMemberCallExpr> 4778 TheCall(this, new (Context) CXXMemberCallExpr(Context, MemExpr, Args, 4779 NumArgs, 4780 Method->getResultType().getNonReferenceType(), 4781 RParenLoc)); 4782 4783 // Convert the object argument (for a non-static member function call). 4784 if (!Method->isStatic() && 4785 PerformObjectArgumentInitialization(ObjectArg, Method)) 4786 return true; 4787 MemExpr->setBase(ObjectArg); 4788 4789 // Convert the rest of the arguments 4790 const FunctionProtoType *Proto = cast<FunctionProtoType>(Method->getType()); 4791 if (ConvertArgumentsForCall(&*TheCall, MemExpr, Method, Proto, Args, NumArgs, 4792 RParenLoc)) 4793 return true; 4794 4795 if (CheckFunctionCall(Method, TheCall.get())) 4796 return true; 4797 4798 return MaybeBindToTemporary(TheCall.release()).release(); 4799} 4800 4801/// BuildCallToObjectOfClassType - Build a call to an object of class 4802/// type (C++ [over.call.object]), which can end up invoking an 4803/// overloaded function call operator (@c operator()) or performing a 4804/// user-defined conversion on the object argument. 4805Sema::ExprResult 4806Sema::BuildCallToObjectOfClassType(Scope *S, Expr *Object, 4807 SourceLocation LParenLoc, 4808 Expr **Args, unsigned NumArgs, 4809 SourceLocation *CommaLocs, 4810 SourceLocation RParenLoc) { 4811 assert(Object->getType()->isRecordType() && "Requires object type argument"); 4812 const RecordType *Record = Object->getType()->getAs<RecordType>(); 4813 4814 // C++ [over.call.object]p1: 4815 // If the primary-expression E in the function call syntax 4816 // evaluates to a class object of type "cv T", then the set of 4817 // candidate functions includes at least the function call 4818 // operators of T. The function call operators of T are obtained by 4819 // ordinary lookup of the name operator() in the context of 4820 // (E).operator(). 4821 OverloadCandidateSet CandidateSet; 4822 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Call); 4823 DeclContext::lookup_const_iterator Oper, OperEnd; 4824 for (llvm::tie(Oper, OperEnd) = Record->getDecl()->lookup(OpName); 4825 Oper != OperEnd; ++Oper) 4826 AddMethodCandidate(cast<CXXMethodDecl>(*Oper), Object, Args, NumArgs, 4827 CandidateSet, /*SuppressUserConversions=*/false); 4828 4829 // C++ [over.call.object]p2: 4830 // In addition, for each conversion function declared in T of the 4831 // form 4832 // 4833 // operator conversion-type-id () cv-qualifier; 4834 // 4835 // where cv-qualifier is the same cv-qualification as, or a 4836 // greater cv-qualification than, cv, and where conversion-type-id 4837 // denotes the type "pointer to function of (P1,...,Pn) returning 4838 // R", or the type "reference to pointer to function of 4839 // (P1,...,Pn) returning R", or the type "reference to function 4840 // of (P1,...,Pn) returning R", a surrogate call function [...] 4841 // is also considered as a candidate function. Similarly, 4842 // surrogate call functions are added to the set of candidate 4843 // functions for each conversion function declared in an 4844 // accessible base class provided the function is not hidden 4845 // within T by another intervening declaration. 4846 4847 if (!RequireCompleteType(SourceLocation(), Object->getType(), 0)) { 4848 // FIXME: Look in base classes for more conversion operators! 4849 OverloadedFunctionDecl *Conversions 4850 = cast<CXXRecordDecl>(Record->getDecl())->getConversionFunctions(); 4851 for (OverloadedFunctionDecl::function_iterator 4852 Func = Conversions->function_begin(), 4853 FuncEnd = Conversions->function_end(); 4854 Func != FuncEnd; ++Func) { 4855 CXXConversionDecl *Conv; 4856 FunctionTemplateDecl *ConvTemplate; 4857 GetFunctionAndTemplate(*Func, Conv, ConvTemplate); 4858 4859 // Skip over templated conversion functions; they aren't 4860 // surrogates. 4861 if (ConvTemplate) 4862 continue; 4863 4864 // Strip the reference type (if any) and then the pointer type (if 4865 // any) to get down to what might be a function type. 4866 QualType ConvType = Conv->getConversionType().getNonReferenceType(); 4867 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 4868 ConvType = ConvPtrType->getPointeeType(); 4869 4870 if (const FunctionProtoType *Proto = ConvType->getAs<FunctionProtoType>()) 4871 AddSurrogateCandidate(Conv, Proto, Object, Args, NumArgs, CandidateSet); 4872 } 4873 } 4874 4875 // Perform overload resolution. 4876 OverloadCandidateSet::iterator Best; 4877 switch (BestViableFunction(CandidateSet, Object->getLocStart(), Best)) { 4878 case OR_Success: 4879 // Overload resolution succeeded; we'll build the appropriate call 4880 // below. 4881 break; 4882 4883 case OR_No_Viable_Function: 4884 Diag(Object->getSourceRange().getBegin(), 4885 diag::err_ovl_no_viable_object_call) 4886 << Object->getType() << Object->getSourceRange(); 4887 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4888 break; 4889 4890 case OR_Ambiguous: 4891 Diag(Object->getSourceRange().getBegin(), 4892 diag::err_ovl_ambiguous_object_call) 4893 << Object->getType() << Object->getSourceRange(); 4894 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4895 break; 4896 4897 case OR_Deleted: 4898 Diag(Object->getSourceRange().getBegin(), 4899 diag::err_ovl_deleted_object_call) 4900 << Best->Function->isDeleted() 4901 << Object->getType() << Object->getSourceRange(); 4902 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4903 break; 4904 } 4905 4906 if (Best == CandidateSet.end()) { 4907 // We had an error; delete all of the subexpressions and return 4908 // the error. 4909 Object->Destroy(Context); 4910 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 4911 Args[ArgIdx]->Destroy(Context); 4912 return true; 4913 } 4914 4915 if (Best->Function == 0) { 4916 // Since there is no function declaration, this is one of the 4917 // surrogate candidates. Dig out the conversion function. 4918 CXXConversionDecl *Conv 4919 = cast<CXXConversionDecl>( 4920 Best->Conversions[0].UserDefined.ConversionFunction); 4921 4922 // We selected one of the surrogate functions that converts the 4923 // object parameter to a function pointer. Perform the conversion 4924 // on the object argument, then let ActOnCallExpr finish the job. 4925 4926 // Create an implicit member expr to refer to the conversion operator. 4927 // and then call it. 4928 CXXMemberCallExpr *CE = 4929 BuildCXXMemberCallExpr(Object, Conv); 4930 4931 return ActOnCallExpr(S, ExprArg(*this, CE), LParenLoc, 4932 MultiExprArg(*this, (ExprTy**)Args, NumArgs), 4933 CommaLocs, RParenLoc).release(); 4934 } 4935 4936 // We found an overloaded operator(). Build a CXXOperatorCallExpr 4937 // that calls this method, using Object for the implicit object 4938 // parameter and passing along the remaining arguments. 4939 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 4940 const FunctionProtoType *Proto = Method->getType()->getAs<FunctionProtoType>(); 4941 4942 unsigned NumArgsInProto = Proto->getNumArgs(); 4943 unsigned NumArgsToCheck = NumArgs; 4944 4945 // Build the full argument list for the method call (the 4946 // implicit object parameter is placed at the beginning of the 4947 // list). 4948 Expr **MethodArgs; 4949 if (NumArgs < NumArgsInProto) { 4950 NumArgsToCheck = NumArgsInProto; 4951 MethodArgs = new Expr*[NumArgsInProto + 1]; 4952 } else { 4953 MethodArgs = new Expr*[NumArgs + 1]; 4954 } 4955 MethodArgs[0] = Object; 4956 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 4957 MethodArgs[ArgIdx + 1] = Args[ArgIdx]; 4958 4959 Expr *NewFn = new (Context) DeclRefExpr(Method, Method->getType(), 4960 SourceLocation()); 4961 UsualUnaryConversions(NewFn); 4962 4963 // Once we've built TheCall, all of the expressions are properly 4964 // owned. 4965 QualType ResultTy = Method->getResultType().getNonReferenceType(); 4966 ExprOwningPtr<CXXOperatorCallExpr> 4967 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Call, NewFn, 4968 MethodArgs, NumArgs + 1, 4969 ResultTy, RParenLoc)); 4970 delete [] MethodArgs; 4971 4972 // We may have default arguments. If so, we need to allocate more 4973 // slots in the call for them. 4974 if (NumArgs < NumArgsInProto) 4975 TheCall->setNumArgs(Context, NumArgsInProto + 1); 4976 else if (NumArgs > NumArgsInProto) 4977 NumArgsToCheck = NumArgsInProto; 4978 4979 bool IsError = false; 4980 4981 // Initialize the implicit object parameter. 4982 IsError |= PerformObjectArgumentInitialization(Object, Method); 4983 TheCall->setArg(0, Object); 4984 4985 4986 // Check the argument types. 4987 for (unsigned i = 0; i != NumArgsToCheck; i++) { 4988 Expr *Arg; 4989 if (i < NumArgs) { 4990 Arg = Args[i]; 4991 4992 // Pass the argument. 4993 QualType ProtoArgType = Proto->getArgType(i); 4994 IsError |= PerformCopyInitialization(Arg, ProtoArgType, "passing"); 4995 } else { 4996 Arg = CXXDefaultArgExpr::Create(Context, Method->getParamDecl(i)); 4997 } 4998 4999 TheCall->setArg(i + 1, Arg); 5000 } 5001 5002 // If this is a variadic call, handle args passed through "...". 5003 if (Proto->isVariadic()) { 5004 // Promote the arguments (C99 6.5.2.2p7). 5005 for (unsigned i = NumArgsInProto; i != NumArgs; i++) { 5006 Expr *Arg = Args[i]; 5007 IsError |= DefaultVariadicArgumentPromotion(Arg, VariadicMethod); 5008 TheCall->setArg(i + 1, Arg); 5009 } 5010 } 5011 5012 if (IsError) return true; 5013 5014 if (CheckFunctionCall(Method, TheCall.get())) 5015 return true; 5016 5017 return MaybeBindToTemporary(TheCall.release()).release(); 5018} 5019 5020/// BuildOverloadedArrowExpr - Build a call to an overloaded @c operator-> 5021/// (if one exists), where @c Base is an expression of class type and 5022/// @c Member is the name of the member we're trying to find. 5023Sema::OwningExprResult 5024Sema::BuildOverloadedArrowExpr(Scope *S, ExprArg BaseIn, SourceLocation OpLoc) { 5025 Expr *Base = static_cast<Expr *>(BaseIn.get()); 5026 assert(Base->getType()->isRecordType() && "left-hand side must have class type"); 5027 5028 // C++ [over.ref]p1: 5029 // 5030 // [...] An expression x->m is interpreted as (x.operator->())->m 5031 // for a class object x of type T if T::operator->() exists and if 5032 // the operator is selected as the best match function by the 5033 // overload resolution mechanism (13.3). 5034 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Arrow); 5035 OverloadCandidateSet CandidateSet; 5036 const RecordType *BaseRecord = Base->getType()->getAs<RecordType>(); 5037 5038 LookupResult R = LookupQualifiedName(BaseRecord->getDecl(), OpName, 5039 LookupOrdinaryName); 5040 5041 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 5042 Oper != OperEnd; ++Oper) 5043 AddMethodCandidate(cast<CXXMethodDecl>(*Oper), Base, 0, 0, CandidateSet, 5044 /*SuppressUserConversions=*/false); 5045 5046 // Perform overload resolution. 5047 OverloadCandidateSet::iterator Best; 5048 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 5049 case OR_Success: 5050 // Overload resolution succeeded; we'll build the call below. 5051 break; 5052 5053 case OR_No_Viable_Function: 5054 if (CandidateSet.empty()) 5055 Diag(OpLoc, diag::err_typecheck_member_reference_arrow) 5056 << Base->getType() << Base->getSourceRange(); 5057 else 5058 Diag(OpLoc, diag::err_ovl_no_viable_oper) 5059 << "operator->" << Base->getSourceRange(); 5060 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 5061 return ExprError(); 5062 5063 case OR_Ambiguous: 5064 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 5065 << "->" << Base->getSourceRange(); 5066 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 5067 return ExprError(); 5068 5069 case OR_Deleted: 5070 Diag(OpLoc, diag::err_ovl_deleted_oper) 5071 << Best->Function->isDeleted() 5072 << "->" << Base->getSourceRange(); 5073 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 5074 return ExprError(); 5075 } 5076 5077 // Convert the object parameter. 5078 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 5079 if (PerformObjectArgumentInitialization(Base, Method)) 5080 return ExprError(); 5081 5082 // No concerns about early exits now. 5083 BaseIn.release(); 5084 5085 // Build the operator call. 5086 Expr *FnExpr = new (Context) DeclRefExpr(Method, Method->getType(), 5087 SourceLocation()); 5088 UsualUnaryConversions(FnExpr); 5089 Base = new (Context) CXXOperatorCallExpr(Context, OO_Arrow, FnExpr, &Base, 1, 5090 Method->getResultType().getNonReferenceType(), 5091 Method->getLocation()); 5092 return Owned(Base); 5093} 5094 5095/// FixOverloadedFunctionReference - E is an expression that refers to 5096/// a C++ overloaded function (possibly with some parentheses and 5097/// perhaps a '&' around it). We have resolved the overloaded function 5098/// to the function declaration Fn, so patch up the expression E to 5099/// refer (possibly indirectly) to Fn. 5100void Sema::FixOverloadedFunctionReference(Expr *E, FunctionDecl *Fn) { 5101 if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) { 5102 FixOverloadedFunctionReference(PE->getSubExpr(), Fn); 5103 E->setType(PE->getSubExpr()->getType()); 5104 } else if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(E)) { 5105 assert(UnOp->getOpcode() == UnaryOperator::AddrOf && 5106 "Can only take the address of an overloaded function"); 5107 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 5108 if (Method->isStatic()) { 5109 // Do nothing: static member functions aren't any different 5110 // from non-member functions. 5111 } else if (QualifiedDeclRefExpr *DRE 5112 = dyn_cast<QualifiedDeclRefExpr>(UnOp->getSubExpr())) { 5113 // We have taken the address of a pointer to member 5114 // function. Perform the computation here so that we get the 5115 // appropriate pointer to member type. 5116 DRE->setDecl(Fn); 5117 DRE->setType(Fn->getType()); 5118 QualType ClassType 5119 = Context.getTypeDeclType(cast<RecordDecl>(Method->getDeclContext())); 5120 E->setType(Context.getMemberPointerType(Fn->getType(), 5121 ClassType.getTypePtr())); 5122 return; 5123 } 5124 } 5125 FixOverloadedFunctionReference(UnOp->getSubExpr(), Fn); 5126 E->setType(Context.getPointerType(UnOp->getSubExpr()->getType())); 5127 } else if (DeclRefExpr *DR = dyn_cast<DeclRefExpr>(E)) { 5128 assert((isa<OverloadedFunctionDecl>(DR->getDecl()) || 5129 isa<FunctionTemplateDecl>(DR->getDecl())) && 5130 "Expected overloaded function or function template"); 5131 DR->setDecl(Fn); 5132 E->setType(Fn->getType()); 5133 } else if (MemberExpr *MemExpr = dyn_cast<MemberExpr>(E)) { 5134 MemExpr->setMemberDecl(Fn); 5135 E->setType(Fn->getType()); 5136 } else { 5137 assert(false && "Invalid reference to overloaded function"); 5138 } 5139} 5140 5141} // end namespace clang 5142