SemaOverload.cpp revision 8621d01b253e3f36976d75dd999bdc0f21d9e5d9
1//===--- SemaOverload.cpp - C++ Overloading ---------------------*- C++ -*-===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This file provides Sema routines for C++ overloading. 11// 12//===----------------------------------------------------------------------===// 13 14#include "Sema.h" 15#include "clang/Basic/Diagnostic.h" 16#include "clang/Lex/Preprocessor.h" 17#include "clang/AST/ASTContext.h" 18#include "clang/AST/CXXInheritance.h" 19#include "clang/AST/Expr.h" 20#include "clang/AST/ExprCXX.h" 21#include "clang/AST/TypeOrdering.h" 22#include "clang/Basic/PartialDiagnostic.h" 23#include "llvm/ADT/SmallPtrSet.h" 24#include "llvm/ADT/STLExtras.h" 25#include "llvm/Support/Compiler.h" 26#include <algorithm> 27#include <cstdio> 28 29namespace clang { 30 31/// GetConversionCategory - Retrieve the implicit conversion 32/// category corresponding to the given implicit conversion kind. 33ImplicitConversionCategory 34GetConversionCategory(ImplicitConversionKind Kind) { 35 static const ImplicitConversionCategory 36 Category[(int)ICK_Num_Conversion_Kinds] = { 37 ICC_Identity, 38 ICC_Lvalue_Transformation, 39 ICC_Lvalue_Transformation, 40 ICC_Lvalue_Transformation, 41 ICC_Qualification_Adjustment, 42 ICC_Promotion, 43 ICC_Promotion, 44 ICC_Promotion, 45 ICC_Conversion, 46 ICC_Conversion, 47 ICC_Conversion, 48 ICC_Conversion, 49 ICC_Conversion, 50 ICC_Conversion, 51 ICC_Conversion, 52 ICC_Conversion, 53 ICC_Conversion, 54 ICC_Conversion 55 }; 56 return Category[(int)Kind]; 57} 58 59/// GetConversionRank - Retrieve the implicit conversion rank 60/// corresponding to the given implicit conversion kind. 61ImplicitConversionRank GetConversionRank(ImplicitConversionKind Kind) { 62 static const ImplicitConversionRank 63 Rank[(int)ICK_Num_Conversion_Kinds] = { 64 ICR_Exact_Match, 65 ICR_Exact_Match, 66 ICR_Exact_Match, 67 ICR_Exact_Match, 68 ICR_Exact_Match, 69 ICR_Promotion, 70 ICR_Promotion, 71 ICR_Promotion, 72 ICR_Conversion, 73 ICR_Conversion, 74 ICR_Conversion, 75 ICR_Conversion, 76 ICR_Conversion, 77 ICR_Conversion, 78 ICR_Conversion, 79 ICR_Conversion, 80 ICR_Conversion, 81 ICR_Conversion 82 }; 83 return Rank[(int)Kind]; 84} 85 86/// GetImplicitConversionName - Return the name of this kind of 87/// implicit conversion. 88const char* GetImplicitConversionName(ImplicitConversionKind Kind) { 89 static const char* Name[(int)ICK_Num_Conversion_Kinds] = { 90 "No conversion", 91 "Lvalue-to-rvalue", 92 "Array-to-pointer", 93 "Function-to-pointer", 94 "Qualification", 95 "Integral promotion", 96 "Floating point promotion", 97 "Complex promotion", 98 "Integral conversion", 99 "Floating conversion", 100 "Complex conversion", 101 "Floating-integral conversion", 102 "Complex-real conversion", 103 "Pointer conversion", 104 "Pointer-to-member conversion", 105 "Boolean conversion", 106 "Compatible-types conversion", 107 "Derived-to-base conversion" 108 }; 109 return Name[Kind]; 110} 111 112/// StandardConversionSequence - Set the standard conversion 113/// sequence to the identity conversion. 114void StandardConversionSequence::setAsIdentityConversion() { 115 First = ICK_Identity; 116 Second = ICK_Identity; 117 Third = ICK_Identity; 118 Deprecated = false; 119 ReferenceBinding = false; 120 DirectBinding = false; 121 RRefBinding = false; 122 CopyConstructor = 0; 123} 124 125/// getRank - Retrieve the rank of this standard conversion sequence 126/// (C++ 13.3.3.1.1p3). The rank is the largest rank of each of the 127/// implicit conversions. 128ImplicitConversionRank StandardConversionSequence::getRank() const { 129 ImplicitConversionRank Rank = ICR_Exact_Match; 130 if (GetConversionRank(First) > Rank) 131 Rank = GetConversionRank(First); 132 if (GetConversionRank(Second) > Rank) 133 Rank = GetConversionRank(Second); 134 if (GetConversionRank(Third) > Rank) 135 Rank = GetConversionRank(Third); 136 return Rank; 137} 138 139/// isPointerConversionToBool - Determines whether this conversion is 140/// a conversion of a pointer or pointer-to-member to bool. This is 141/// used as part of the ranking of standard conversion sequences 142/// (C++ 13.3.3.2p4). 143bool StandardConversionSequence::isPointerConversionToBool() const { 144 QualType FromType = QualType::getFromOpaquePtr(FromTypePtr); 145 QualType ToType = QualType::getFromOpaquePtr(ToTypePtr); 146 147 // Note that FromType has not necessarily been transformed by the 148 // array-to-pointer or function-to-pointer implicit conversions, so 149 // check for their presence as well as checking whether FromType is 150 // a pointer. 151 if (ToType->isBooleanType() && 152 (FromType->isPointerType() || FromType->isBlockPointerType() || 153 First == ICK_Array_To_Pointer || First == ICK_Function_To_Pointer)) 154 return true; 155 156 return false; 157} 158 159/// isPointerConversionToVoidPointer - Determines whether this 160/// conversion is a conversion of a pointer to a void pointer. This is 161/// used as part of the ranking of standard conversion sequences (C++ 162/// 13.3.3.2p4). 163bool 164StandardConversionSequence:: 165isPointerConversionToVoidPointer(ASTContext& Context) const { 166 QualType FromType = QualType::getFromOpaquePtr(FromTypePtr); 167 QualType ToType = QualType::getFromOpaquePtr(ToTypePtr); 168 169 // Note that FromType has not necessarily been transformed by the 170 // array-to-pointer implicit conversion, so check for its presence 171 // and redo the conversion to get a pointer. 172 if (First == ICK_Array_To_Pointer) 173 FromType = Context.getArrayDecayedType(FromType); 174 175 if (Second == ICK_Pointer_Conversion) 176 if (const PointerType* ToPtrType = ToType->getAs<PointerType>()) 177 return ToPtrType->getPointeeType()->isVoidType(); 178 179 return false; 180} 181 182/// DebugPrint - Print this standard conversion sequence to standard 183/// error. Useful for debugging overloading issues. 184void StandardConversionSequence::DebugPrint() const { 185 bool PrintedSomething = false; 186 if (First != ICK_Identity) { 187 fprintf(stderr, "%s", GetImplicitConversionName(First)); 188 PrintedSomething = true; 189 } 190 191 if (Second != ICK_Identity) { 192 if (PrintedSomething) { 193 fprintf(stderr, " -> "); 194 } 195 fprintf(stderr, "%s", GetImplicitConversionName(Second)); 196 197 if (CopyConstructor) { 198 fprintf(stderr, " (by copy constructor)"); 199 } else if (DirectBinding) { 200 fprintf(stderr, " (direct reference binding)"); 201 } else if (ReferenceBinding) { 202 fprintf(stderr, " (reference binding)"); 203 } 204 PrintedSomething = true; 205 } 206 207 if (Third != ICK_Identity) { 208 if (PrintedSomething) { 209 fprintf(stderr, " -> "); 210 } 211 fprintf(stderr, "%s", GetImplicitConversionName(Third)); 212 PrintedSomething = true; 213 } 214 215 if (!PrintedSomething) { 216 fprintf(stderr, "No conversions required"); 217 } 218} 219 220/// DebugPrint - Print this user-defined conversion sequence to standard 221/// error. Useful for debugging overloading issues. 222void UserDefinedConversionSequence::DebugPrint() const { 223 if (Before.First || Before.Second || Before.Third) { 224 Before.DebugPrint(); 225 fprintf(stderr, " -> "); 226 } 227 fprintf(stderr, "'%s'", ConversionFunction->getNameAsString().c_str()); 228 if (After.First || After.Second || After.Third) { 229 fprintf(stderr, " -> "); 230 After.DebugPrint(); 231 } 232} 233 234/// DebugPrint - Print this implicit conversion sequence to standard 235/// error. Useful for debugging overloading issues. 236void ImplicitConversionSequence::DebugPrint() const { 237 switch (ConversionKind) { 238 case StandardConversion: 239 fprintf(stderr, "Standard conversion: "); 240 Standard.DebugPrint(); 241 break; 242 case UserDefinedConversion: 243 fprintf(stderr, "User-defined conversion: "); 244 UserDefined.DebugPrint(); 245 break; 246 case EllipsisConversion: 247 fprintf(stderr, "Ellipsis conversion"); 248 break; 249 case BadConversion: 250 fprintf(stderr, "Bad conversion"); 251 break; 252 } 253 254 fprintf(stderr, "\n"); 255} 256 257// IsOverload - Determine whether the given New declaration is an 258// overload of the Old declaration. This routine returns false if New 259// and Old cannot be overloaded, e.g., if they are functions with the 260// same signature (C++ 1.3.10) or if the Old declaration isn't a 261// function (or overload set). When it does return false and Old is an 262// OverloadedFunctionDecl, MatchedDecl will be set to point to the 263// FunctionDecl that New cannot be overloaded with. 264// 265// Example: Given the following input: 266// 267// void f(int, float); // #1 268// void f(int, int); // #2 269// int f(int, int); // #3 270// 271// When we process #1, there is no previous declaration of "f", 272// so IsOverload will not be used. 273// 274// When we process #2, Old is a FunctionDecl for #1. By comparing the 275// parameter types, we see that #1 and #2 are overloaded (since they 276// have different signatures), so this routine returns false; 277// MatchedDecl is unchanged. 278// 279// When we process #3, Old is an OverloadedFunctionDecl containing #1 280// and #2. We compare the signatures of #3 to #1 (they're overloaded, 281// so we do nothing) and then #3 to #2. Since the signatures of #3 and 282// #2 are identical (return types of functions are not part of the 283// signature), IsOverload returns false and MatchedDecl will be set to 284// point to the FunctionDecl for #2. 285bool 286Sema::IsOverload(FunctionDecl *New, Decl* OldD, 287 OverloadedFunctionDecl::function_iterator& MatchedDecl) { 288 if (OverloadedFunctionDecl* Ovl = dyn_cast<OverloadedFunctionDecl>(OldD)) { 289 // Is this new function an overload of every function in the 290 // overload set? 291 OverloadedFunctionDecl::function_iterator Func = Ovl->function_begin(), 292 FuncEnd = Ovl->function_end(); 293 for (; Func != FuncEnd; ++Func) { 294 if (!IsOverload(New, *Func, MatchedDecl)) { 295 MatchedDecl = Func; 296 return false; 297 } 298 } 299 300 // This function overloads every function in the overload set. 301 return true; 302 } else if (FunctionTemplateDecl *Old = dyn_cast<FunctionTemplateDecl>(OldD)) 303 return IsOverload(New, Old->getTemplatedDecl(), MatchedDecl); 304 else if (FunctionDecl* Old = dyn_cast<FunctionDecl>(OldD)) { 305 FunctionTemplateDecl *OldTemplate = Old->getDescribedFunctionTemplate(); 306 FunctionTemplateDecl *NewTemplate = New->getDescribedFunctionTemplate(); 307 308 // C++ [temp.fct]p2: 309 // A function template can be overloaded with other function templates 310 // and with normal (non-template) functions. 311 if ((OldTemplate == 0) != (NewTemplate == 0)) 312 return true; 313 314 // Is the function New an overload of the function Old? 315 QualType OldQType = Context.getCanonicalType(Old->getType()); 316 QualType NewQType = Context.getCanonicalType(New->getType()); 317 318 // Compare the signatures (C++ 1.3.10) of the two functions to 319 // determine whether they are overloads. If we find any mismatch 320 // in the signature, they are overloads. 321 322 // If either of these functions is a K&R-style function (no 323 // prototype), then we consider them to have matching signatures. 324 if (isa<FunctionNoProtoType>(OldQType.getTypePtr()) || 325 isa<FunctionNoProtoType>(NewQType.getTypePtr())) 326 return false; 327 328 FunctionProtoType* OldType = cast<FunctionProtoType>(OldQType); 329 FunctionProtoType* NewType = cast<FunctionProtoType>(NewQType); 330 331 // The signature of a function includes the types of its 332 // parameters (C++ 1.3.10), which includes the presence or absence 333 // of the ellipsis; see C++ DR 357). 334 if (OldQType != NewQType && 335 (OldType->getNumArgs() != NewType->getNumArgs() || 336 OldType->isVariadic() != NewType->isVariadic() || 337 !std::equal(OldType->arg_type_begin(), OldType->arg_type_end(), 338 NewType->arg_type_begin()))) 339 return true; 340 341 // C++ [temp.over.link]p4: 342 // The signature of a function template consists of its function 343 // signature, its return type and its template parameter list. The names 344 // of the template parameters are significant only for establishing the 345 // relationship between the template parameters and the rest of the 346 // signature. 347 // 348 // We check the return type and template parameter lists for function 349 // templates first; the remaining checks follow. 350 if (NewTemplate && 351 (!TemplateParameterListsAreEqual(NewTemplate->getTemplateParameters(), 352 OldTemplate->getTemplateParameters(), 353 false, false, SourceLocation()) || 354 OldType->getResultType() != NewType->getResultType())) 355 return true; 356 357 // If the function is a class member, its signature includes the 358 // cv-qualifiers (if any) on the function itself. 359 // 360 // As part of this, also check whether one of the member functions 361 // is static, in which case they are not overloads (C++ 362 // 13.1p2). While not part of the definition of the signature, 363 // this check is important to determine whether these functions 364 // can be overloaded. 365 CXXMethodDecl* OldMethod = dyn_cast<CXXMethodDecl>(Old); 366 CXXMethodDecl* NewMethod = dyn_cast<CXXMethodDecl>(New); 367 if (OldMethod && NewMethod && 368 !OldMethod->isStatic() && !NewMethod->isStatic() && 369 OldMethod->getTypeQualifiers() != NewMethod->getTypeQualifiers()) 370 return true; 371 372 // The signatures match; this is not an overload. 373 return false; 374 } else { 375 // (C++ 13p1): 376 // Only function declarations can be overloaded; object and type 377 // declarations cannot be overloaded. 378 return false; 379 } 380} 381 382/// TryImplicitConversion - Attempt to perform an implicit conversion 383/// from the given expression (Expr) to the given type (ToType). This 384/// function returns an implicit conversion sequence that can be used 385/// to perform the initialization. Given 386/// 387/// void f(float f); 388/// void g(int i) { f(i); } 389/// 390/// this routine would produce an implicit conversion sequence to 391/// describe the initialization of f from i, which will be a standard 392/// conversion sequence containing an lvalue-to-rvalue conversion (C++ 393/// 4.1) followed by a floating-integral conversion (C++ 4.9). 394// 395/// Note that this routine only determines how the conversion can be 396/// performed; it does not actually perform the conversion. As such, 397/// it will not produce any diagnostics if no conversion is available, 398/// but will instead return an implicit conversion sequence of kind 399/// "BadConversion". 400/// 401/// If @p SuppressUserConversions, then user-defined conversions are 402/// not permitted. 403/// If @p AllowExplicit, then explicit user-defined conversions are 404/// permitted. 405/// If @p ForceRValue, then overloading is performed as if From was an rvalue, 406/// no matter its actual lvalueness. 407/// If @p UserCast, the implicit conversion is being done for a user-specified 408/// cast. 409ImplicitConversionSequence 410Sema::TryImplicitConversion(Expr* From, QualType ToType, 411 bool SuppressUserConversions, 412 bool AllowExplicit, bool ForceRValue, 413 bool InOverloadResolution, 414 bool UserCast) { 415 ImplicitConversionSequence ICS; 416 OverloadCandidateSet Conversions; 417 OverloadingResult UserDefResult = OR_Success; 418 if (IsStandardConversion(From, ToType, InOverloadResolution, ICS.Standard)) 419 ICS.ConversionKind = ImplicitConversionSequence::StandardConversion; 420 else if (getLangOptions().CPlusPlus && 421 (UserDefResult = IsUserDefinedConversion(From, ToType, 422 ICS.UserDefined, 423 Conversions, 424 !SuppressUserConversions, AllowExplicit, 425 ForceRValue, UserCast)) == OR_Success) { 426 ICS.ConversionKind = ImplicitConversionSequence::UserDefinedConversion; 427 // C++ [over.ics.user]p4: 428 // A conversion of an expression of class type to the same class 429 // type is given Exact Match rank, and a conversion of an 430 // expression of class type to a base class of that type is 431 // given Conversion rank, in spite of the fact that a copy 432 // constructor (i.e., a user-defined conversion function) is 433 // called for those cases. 434 if (CXXConstructorDecl *Constructor 435 = dyn_cast<CXXConstructorDecl>(ICS.UserDefined.ConversionFunction)) { 436 QualType FromCanon 437 = Context.getCanonicalType(From->getType().getUnqualifiedType()); 438 QualType ToCanon = Context.getCanonicalType(ToType).getUnqualifiedType(); 439 if (FromCanon == ToCanon || IsDerivedFrom(FromCanon, ToCanon)) { 440 // Turn this into a "standard" conversion sequence, so that it 441 // gets ranked with standard conversion sequences. 442 ICS.ConversionKind = ImplicitConversionSequence::StandardConversion; 443 ICS.Standard.setAsIdentityConversion(); 444 ICS.Standard.FromTypePtr = From->getType().getAsOpaquePtr(); 445 ICS.Standard.ToTypePtr = ToType.getAsOpaquePtr(); 446 ICS.Standard.CopyConstructor = Constructor; 447 if (ToCanon != FromCanon) 448 ICS.Standard.Second = ICK_Derived_To_Base; 449 } 450 } 451 452 // C++ [over.best.ics]p4: 453 // However, when considering the argument of a user-defined 454 // conversion function that is a candidate by 13.3.1.3 when 455 // invoked for the copying of the temporary in the second step 456 // of a class copy-initialization, or by 13.3.1.4, 13.3.1.5, or 457 // 13.3.1.6 in all cases, only standard conversion sequences and 458 // ellipsis conversion sequences are allowed. 459 if (SuppressUserConversions && 460 ICS.ConversionKind == ImplicitConversionSequence::UserDefinedConversion) 461 ICS.ConversionKind = ImplicitConversionSequence::BadConversion; 462 } else { 463 ICS.ConversionKind = ImplicitConversionSequence::BadConversion; 464 if (UserDefResult == OR_Ambiguous) { 465 for (OverloadCandidateSet::iterator Cand = Conversions.begin(); 466 Cand != Conversions.end(); ++Cand) 467 if (Cand->Viable) 468 ICS.ConversionFunctionSet.push_back(Cand->Function); 469 } 470 } 471 472 return ICS; 473} 474 475/// IsStandardConversion - Determines whether there is a standard 476/// conversion sequence (C++ [conv], C++ [over.ics.scs]) from the 477/// expression From to the type ToType. Standard conversion sequences 478/// only consider non-class types; for conversions that involve class 479/// types, use TryImplicitConversion. If a conversion exists, SCS will 480/// contain the standard conversion sequence required to perform this 481/// conversion and this routine will return true. Otherwise, this 482/// routine will return false and the value of SCS is unspecified. 483bool 484Sema::IsStandardConversion(Expr* From, QualType ToType, 485 bool InOverloadResolution, 486 StandardConversionSequence &SCS) { 487 QualType FromType = From->getType(); 488 489 // Standard conversions (C++ [conv]) 490 SCS.setAsIdentityConversion(); 491 SCS.Deprecated = false; 492 SCS.IncompatibleObjC = false; 493 SCS.FromTypePtr = FromType.getAsOpaquePtr(); 494 SCS.CopyConstructor = 0; 495 496 // There are no standard conversions for class types in C++, so 497 // abort early. When overloading in C, however, we do permit 498 if (FromType->isRecordType() || ToType->isRecordType()) { 499 if (getLangOptions().CPlusPlus) 500 return false; 501 502 // When we're overloading in C, we allow, as standard conversions, 503 } 504 505 // The first conversion can be an lvalue-to-rvalue conversion, 506 // array-to-pointer conversion, or function-to-pointer conversion 507 // (C++ 4p1). 508 509 // Lvalue-to-rvalue conversion (C++ 4.1): 510 // An lvalue (3.10) of a non-function, non-array type T can be 511 // converted to an rvalue. 512 Expr::isLvalueResult argIsLvalue = From->isLvalue(Context); 513 if (argIsLvalue == Expr::LV_Valid && 514 !FromType->isFunctionType() && !FromType->isArrayType() && 515 Context.getCanonicalType(FromType) != Context.OverloadTy) { 516 SCS.First = ICK_Lvalue_To_Rvalue; 517 518 // If T is a non-class type, the type of the rvalue is the 519 // cv-unqualified version of T. Otherwise, the type of the rvalue 520 // is T (C++ 4.1p1). C++ can't get here with class types; in C, we 521 // just strip the qualifiers because they don't matter. 522 523 // FIXME: Doesn't see through to qualifiers behind a typedef! 524 FromType = FromType.getUnqualifiedType(); 525 } else if (FromType->isArrayType()) { 526 // Array-to-pointer conversion (C++ 4.2) 527 SCS.First = ICK_Array_To_Pointer; 528 529 // An lvalue or rvalue of type "array of N T" or "array of unknown 530 // bound of T" can be converted to an rvalue of type "pointer to 531 // T" (C++ 4.2p1). 532 FromType = Context.getArrayDecayedType(FromType); 533 534 if (IsStringLiteralToNonConstPointerConversion(From, ToType)) { 535 // This conversion is deprecated. (C++ D.4). 536 SCS.Deprecated = true; 537 538 // For the purpose of ranking in overload resolution 539 // (13.3.3.1.1), this conversion is considered an 540 // array-to-pointer conversion followed by a qualification 541 // conversion (4.4). (C++ 4.2p2) 542 SCS.Second = ICK_Identity; 543 SCS.Third = ICK_Qualification; 544 SCS.ToTypePtr = ToType.getAsOpaquePtr(); 545 return true; 546 } 547 } else if (FromType->isFunctionType() && argIsLvalue == Expr::LV_Valid) { 548 // Function-to-pointer conversion (C++ 4.3). 549 SCS.First = ICK_Function_To_Pointer; 550 551 // An lvalue of function type T can be converted to an rvalue of 552 // type "pointer to T." The result is a pointer to the 553 // function. (C++ 4.3p1). 554 FromType = Context.getPointerType(FromType); 555 } else if (FunctionDecl *Fn 556 = ResolveAddressOfOverloadedFunction(From, ToType, false)) { 557 // Address of overloaded function (C++ [over.over]). 558 SCS.First = ICK_Function_To_Pointer; 559 560 // We were able to resolve the address of the overloaded function, 561 // so we can convert to the type of that function. 562 FromType = Fn->getType(); 563 if (ToType->isLValueReferenceType()) 564 FromType = Context.getLValueReferenceType(FromType); 565 else if (ToType->isRValueReferenceType()) 566 FromType = Context.getRValueReferenceType(FromType); 567 else if (ToType->isMemberPointerType()) { 568 // Resolve address only succeeds if both sides are member pointers, 569 // but it doesn't have to be the same class. See DR 247. 570 // Note that this means that the type of &Derived::fn can be 571 // Ret (Base::*)(Args) if the fn overload actually found is from the 572 // base class, even if it was brought into the derived class via a 573 // using declaration. The standard isn't clear on this issue at all. 574 CXXMethodDecl *M = cast<CXXMethodDecl>(Fn); 575 FromType = Context.getMemberPointerType(FromType, 576 Context.getTypeDeclType(M->getParent()).getTypePtr()); 577 } else 578 FromType = Context.getPointerType(FromType); 579 } else { 580 // We don't require any conversions for the first step. 581 SCS.First = ICK_Identity; 582 } 583 584 // The second conversion can be an integral promotion, floating 585 // point promotion, integral conversion, floating point conversion, 586 // floating-integral conversion, pointer conversion, 587 // pointer-to-member conversion, or boolean conversion (C++ 4p1). 588 // For overloading in C, this can also be a "compatible-type" 589 // conversion. 590 bool IncompatibleObjC = false; 591 if (Context.hasSameUnqualifiedType(FromType, ToType)) { 592 // The unqualified versions of the types are the same: there's no 593 // conversion to do. 594 SCS.Second = ICK_Identity; 595 } else if (IsIntegralPromotion(From, FromType, ToType)) { 596 // Integral promotion (C++ 4.5). 597 SCS.Second = ICK_Integral_Promotion; 598 FromType = ToType.getUnqualifiedType(); 599 } else if (IsFloatingPointPromotion(FromType, ToType)) { 600 // Floating point promotion (C++ 4.6). 601 SCS.Second = ICK_Floating_Promotion; 602 FromType = ToType.getUnqualifiedType(); 603 } else if (IsComplexPromotion(FromType, ToType)) { 604 // Complex promotion (Clang extension) 605 SCS.Second = ICK_Complex_Promotion; 606 FromType = ToType.getUnqualifiedType(); 607 } else if ((FromType->isIntegralType() || FromType->isEnumeralType()) && 608 (ToType->isIntegralType() && !ToType->isEnumeralType())) { 609 // Integral conversions (C++ 4.7). 610 // FIXME: isIntegralType shouldn't be true for enums in C++. 611 SCS.Second = ICK_Integral_Conversion; 612 FromType = ToType.getUnqualifiedType(); 613 } else if (FromType->isFloatingType() && ToType->isFloatingType()) { 614 // Floating point conversions (C++ 4.8). 615 SCS.Second = ICK_Floating_Conversion; 616 FromType = ToType.getUnqualifiedType(); 617 } else if (FromType->isComplexType() && ToType->isComplexType()) { 618 // Complex conversions (C99 6.3.1.6) 619 SCS.Second = ICK_Complex_Conversion; 620 FromType = ToType.getUnqualifiedType(); 621 } else if ((FromType->isFloatingType() && 622 ToType->isIntegralType() && (!ToType->isBooleanType() && 623 !ToType->isEnumeralType())) || 624 ((FromType->isIntegralType() || FromType->isEnumeralType()) && 625 ToType->isFloatingType())) { 626 // Floating-integral conversions (C++ 4.9). 627 // FIXME: isIntegralType shouldn't be true for enums in C++. 628 SCS.Second = ICK_Floating_Integral; 629 FromType = ToType.getUnqualifiedType(); 630 } else if ((FromType->isComplexType() && ToType->isArithmeticType()) || 631 (ToType->isComplexType() && FromType->isArithmeticType())) { 632 // Complex-real conversions (C99 6.3.1.7) 633 SCS.Second = ICK_Complex_Real; 634 FromType = ToType.getUnqualifiedType(); 635 } else if (IsPointerConversion(From, FromType, ToType, InOverloadResolution, 636 FromType, IncompatibleObjC)) { 637 // Pointer conversions (C++ 4.10). 638 SCS.Second = ICK_Pointer_Conversion; 639 SCS.IncompatibleObjC = IncompatibleObjC; 640 } else if (IsMemberPointerConversion(From, FromType, ToType, 641 InOverloadResolution, FromType)) { 642 // Pointer to member conversions (4.11). 643 SCS.Second = ICK_Pointer_Member; 644 } else if (ToType->isBooleanType() && 645 (FromType->isArithmeticType() || 646 FromType->isEnumeralType() || 647 FromType->isPointerType() || 648 FromType->isBlockPointerType() || 649 FromType->isMemberPointerType() || 650 FromType->isNullPtrType())) { 651 // Boolean conversions (C++ 4.12). 652 SCS.Second = ICK_Boolean_Conversion; 653 FromType = Context.BoolTy; 654 } else if (!getLangOptions().CPlusPlus && 655 Context.typesAreCompatible(ToType, FromType)) { 656 // Compatible conversions (Clang extension for C function overloading) 657 SCS.Second = ICK_Compatible_Conversion; 658 } else { 659 // No second conversion required. 660 SCS.Second = ICK_Identity; 661 } 662 663 QualType CanonFrom; 664 QualType CanonTo; 665 // The third conversion can be a qualification conversion (C++ 4p1). 666 if (IsQualificationConversion(FromType, ToType)) { 667 SCS.Third = ICK_Qualification; 668 FromType = ToType; 669 CanonFrom = Context.getCanonicalType(FromType); 670 CanonTo = Context.getCanonicalType(ToType); 671 } else { 672 // No conversion required 673 SCS.Third = ICK_Identity; 674 675 // C++ [over.best.ics]p6: 676 // [...] Any difference in top-level cv-qualification is 677 // subsumed by the initialization itself and does not constitute 678 // a conversion. [...] 679 CanonFrom = Context.getCanonicalType(FromType); 680 CanonTo = Context.getCanonicalType(ToType); 681 if (CanonFrom.getUnqualifiedType() == CanonTo.getUnqualifiedType() && 682 CanonFrom.getCVRQualifiers() != CanonTo.getCVRQualifiers()) { 683 FromType = ToType; 684 CanonFrom = CanonTo; 685 } 686 } 687 688 // If we have not converted the argument type to the parameter type, 689 // this is a bad conversion sequence. 690 if (CanonFrom != CanonTo) 691 return false; 692 693 SCS.ToTypePtr = FromType.getAsOpaquePtr(); 694 return true; 695} 696 697/// IsIntegralPromotion - Determines whether the conversion from the 698/// expression From (whose potentially-adjusted type is FromType) to 699/// ToType is an integral promotion (C++ 4.5). If so, returns true and 700/// sets PromotedType to the promoted type. 701bool Sema::IsIntegralPromotion(Expr *From, QualType FromType, QualType ToType) { 702 const BuiltinType *To = ToType->getAs<BuiltinType>(); 703 // All integers are built-in. 704 if (!To) { 705 return false; 706 } 707 708 // An rvalue of type char, signed char, unsigned char, short int, or 709 // unsigned short int can be converted to an rvalue of type int if 710 // int can represent all the values of the source type; otherwise, 711 // the source rvalue can be converted to an rvalue of type unsigned 712 // int (C++ 4.5p1). 713 if (FromType->isPromotableIntegerType() && !FromType->isBooleanType()) { 714 if (// We can promote any signed, promotable integer type to an int 715 (FromType->isSignedIntegerType() || 716 // We can promote any unsigned integer type whose size is 717 // less than int to an int. 718 (!FromType->isSignedIntegerType() && 719 Context.getTypeSize(FromType) < Context.getTypeSize(ToType)))) { 720 return To->getKind() == BuiltinType::Int; 721 } 722 723 return To->getKind() == BuiltinType::UInt; 724 } 725 726 // An rvalue of type wchar_t (3.9.1) or an enumeration type (7.2) 727 // can be converted to an rvalue of the first of the following types 728 // that can represent all the values of its underlying type: int, 729 // unsigned int, long, or unsigned long (C++ 4.5p2). 730 if ((FromType->isEnumeralType() || FromType->isWideCharType()) 731 && ToType->isIntegerType()) { 732 // Determine whether the type we're converting from is signed or 733 // unsigned. 734 bool FromIsSigned; 735 uint64_t FromSize = Context.getTypeSize(FromType); 736 if (const EnumType *FromEnumType = FromType->getAs<EnumType>()) { 737 QualType UnderlyingType = FromEnumType->getDecl()->getIntegerType(); 738 FromIsSigned = UnderlyingType->isSignedIntegerType(); 739 } else { 740 // FIXME: Is wchar_t signed or unsigned? We assume it's signed for now. 741 FromIsSigned = true; 742 } 743 744 // The types we'll try to promote to, in the appropriate 745 // order. Try each of these types. 746 QualType PromoteTypes[6] = { 747 Context.IntTy, Context.UnsignedIntTy, 748 Context.LongTy, Context.UnsignedLongTy , 749 Context.LongLongTy, Context.UnsignedLongLongTy 750 }; 751 for (int Idx = 0; Idx < 6; ++Idx) { 752 uint64_t ToSize = Context.getTypeSize(PromoteTypes[Idx]); 753 if (FromSize < ToSize || 754 (FromSize == ToSize && 755 FromIsSigned == PromoteTypes[Idx]->isSignedIntegerType())) { 756 // We found the type that we can promote to. If this is the 757 // type we wanted, we have a promotion. Otherwise, no 758 // promotion. 759 return Context.getCanonicalType(ToType).getUnqualifiedType() 760 == Context.getCanonicalType(PromoteTypes[Idx]).getUnqualifiedType(); 761 } 762 } 763 } 764 765 // An rvalue for an integral bit-field (9.6) can be converted to an 766 // rvalue of type int if int can represent all the values of the 767 // bit-field; otherwise, it can be converted to unsigned int if 768 // unsigned int can represent all the values of the bit-field. If 769 // the bit-field is larger yet, no integral promotion applies to 770 // it. If the bit-field has an enumerated type, it is treated as any 771 // other value of that type for promotion purposes (C++ 4.5p3). 772 // FIXME: We should delay checking of bit-fields until we actually perform the 773 // conversion. 774 using llvm::APSInt; 775 if (From) 776 if (FieldDecl *MemberDecl = From->getBitField()) { 777 APSInt BitWidth; 778 if (FromType->isIntegralType() && !FromType->isEnumeralType() && 779 MemberDecl->getBitWidth()->isIntegerConstantExpr(BitWidth, Context)) { 780 APSInt ToSize(BitWidth.getBitWidth(), BitWidth.isUnsigned()); 781 ToSize = Context.getTypeSize(ToType); 782 783 // Are we promoting to an int from a bitfield that fits in an int? 784 if (BitWidth < ToSize || 785 (FromType->isSignedIntegerType() && BitWidth <= ToSize)) { 786 return To->getKind() == BuiltinType::Int; 787 } 788 789 // Are we promoting to an unsigned int from an unsigned bitfield 790 // that fits into an unsigned int? 791 if (FromType->isUnsignedIntegerType() && BitWidth <= ToSize) { 792 return To->getKind() == BuiltinType::UInt; 793 } 794 795 return false; 796 } 797 } 798 799 // An rvalue of type bool can be converted to an rvalue of type int, 800 // with false becoming zero and true becoming one (C++ 4.5p4). 801 if (FromType->isBooleanType() && To->getKind() == BuiltinType::Int) { 802 return true; 803 } 804 805 return false; 806} 807 808/// IsFloatingPointPromotion - Determines whether the conversion from 809/// FromType to ToType is a floating point promotion (C++ 4.6). If so, 810/// returns true and sets PromotedType to the promoted type. 811bool Sema::IsFloatingPointPromotion(QualType FromType, QualType ToType) { 812 /// An rvalue of type float can be converted to an rvalue of type 813 /// double. (C++ 4.6p1). 814 if (const BuiltinType *FromBuiltin = FromType->getAs<BuiltinType>()) 815 if (const BuiltinType *ToBuiltin = ToType->getAs<BuiltinType>()) { 816 if (FromBuiltin->getKind() == BuiltinType::Float && 817 ToBuiltin->getKind() == BuiltinType::Double) 818 return true; 819 820 // C99 6.3.1.5p1: 821 // When a float is promoted to double or long double, or a 822 // double is promoted to long double [...]. 823 if (!getLangOptions().CPlusPlus && 824 (FromBuiltin->getKind() == BuiltinType::Float || 825 FromBuiltin->getKind() == BuiltinType::Double) && 826 (ToBuiltin->getKind() == BuiltinType::LongDouble)) 827 return true; 828 } 829 830 return false; 831} 832 833/// \brief Determine if a conversion is a complex promotion. 834/// 835/// A complex promotion is defined as a complex -> complex conversion 836/// where the conversion between the underlying real types is a 837/// floating-point or integral promotion. 838bool Sema::IsComplexPromotion(QualType FromType, QualType ToType) { 839 const ComplexType *FromComplex = FromType->getAs<ComplexType>(); 840 if (!FromComplex) 841 return false; 842 843 const ComplexType *ToComplex = ToType->getAs<ComplexType>(); 844 if (!ToComplex) 845 return false; 846 847 return IsFloatingPointPromotion(FromComplex->getElementType(), 848 ToComplex->getElementType()) || 849 IsIntegralPromotion(0, FromComplex->getElementType(), 850 ToComplex->getElementType()); 851} 852 853/// BuildSimilarlyQualifiedPointerType - In a pointer conversion from 854/// the pointer type FromPtr to a pointer to type ToPointee, with the 855/// same type qualifiers as FromPtr has on its pointee type. ToType, 856/// if non-empty, will be a pointer to ToType that may or may not have 857/// the right set of qualifiers on its pointee. 858static QualType 859BuildSimilarlyQualifiedPointerType(const PointerType *FromPtr, 860 QualType ToPointee, QualType ToType, 861 ASTContext &Context) { 862 QualType CanonFromPointee = Context.getCanonicalType(FromPtr->getPointeeType()); 863 QualType CanonToPointee = Context.getCanonicalType(ToPointee); 864 Qualifiers Quals = CanonFromPointee.getQualifiers(); 865 866 // Exact qualifier match -> return the pointer type we're converting to. 867 if (CanonToPointee.getQualifiers() == Quals) { 868 // ToType is exactly what we need. Return it. 869 if (!ToType.isNull()) 870 return ToType; 871 872 // Build a pointer to ToPointee. It has the right qualifiers 873 // already. 874 return Context.getPointerType(ToPointee); 875 } 876 877 // Just build a canonical type that has the right qualifiers. 878 return Context.getPointerType( 879 Context.getQualifiedType(CanonToPointee.getUnqualifiedType(), Quals)); 880} 881 882static bool isNullPointerConstantForConversion(Expr *Expr, 883 bool InOverloadResolution, 884 ASTContext &Context) { 885 // Handle value-dependent integral null pointer constants correctly. 886 // http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#903 887 if (Expr->isValueDependent() && !Expr->isTypeDependent() && 888 Expr->getType()->isIntegralType()) 889 return !InOverloadResolution; 890 891 return Expr->isNullPointerConstant(Context, 892 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull 893 : Expr::NPC_ValueDependentIsNull); 894} 895 896/// IsPointerConversion - Determines whether the conversion of the 897/// expression From, which has the (possibly adjusted) type FromType, 898/// can be converted to the type ToType via a pointer conversion (C++ 899/// 4.10). If so, returns true and places the converted type (that 900/// might differ from ToType in its cv-qualifiers at some level) into 901/// ConvertedType. 902/// 903/// This routine also supports conversions to and from block pointers 904/// and conversions with Objective-C's 'id', 'id<protocols...>', and 905/// pointers to interfaces. FIXME: Once we've determined the 906/// appropriate overloading rules for Objective-C, we may want to 907/// split the Objective-C checks into a different routine; however, 908/// GCC seems to consider all of these conversions to be pointer 909/// conversions, so for now they live here. IncompatibleObjC will be 910/// set if the conversion is an allowed Objective-C conversion that 911/// should result in a warning. 912bool Sema::IsPointerConversion(Expr *From, QualType FromType, QualType ToType, 913 bool InOverloadResolution, 914 QualType& ConvertedType, 915 bool &IncompatibleObjC) { 916 IncompatibleObjC = false; 917 if (isObjCPointerConversion(FromType, ToType, ConvertedType, IncompatibleObjC)) 918 return true; 919 920 // Conversion from a null pointer constant to any Objective-C pointer type. 921 if (ToType->isObjCObjectPointerType() && 922 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 923 ConvertedType = ToType; 924 return true; 925 } 926 927 // Blocks: Block pointers can be converted to void*. 928 if (FromType->isBlockPointerType() && ToType->isPointerType() && 929 ToType->getAs<PointerType>()->getPointeeType()->isVoidType()) { 930 ConvertedType = ToType; 931 return true; 932 } 933 // Blocks: A null pointer constant can be converted to a block 934 // pointer type. 935 if (ToType->isBlockPointerType() && 936 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 937 ConvertedType = ToType; 938 return true; 939 } 940 941 // If the left-hand-side is nullptr_t, the right side can be a null 942 // pointer constant. 943 if (ToType->isNullPtrType() && 944 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 945 ConvertedType = ToType; 946 return true; 947 } 948 949 const PointerType* ToTypePtr = ToType->getAs<PointerType>(); 950 if (!ToTypePtr) 951 return false; 952 953 // A null pointer constant can be converted to a pointer type (C++ 4.10p1). 954 if (isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 955 ConvertedType = ToType; 956 return true; 957 } 958 959 // Beyond this point, both types need to be pointers. 960 const PointerType *FromTypePtr = FromType->getAs<PointerType>(); 961 if (!FromTypePtr) 962 return false; 963 964 QualType FromPointeeType = FromTypePtr->getPointeeType(); 965 QualType ToPointeeType = ToTypePtr->getPointeeType(); 966 967 // An rvalue of type "pointer to cv T," where T is an object type, 968 // can be converted to an rvalue of type "pointer to cv void" (C++ 969 // 4.10p2). 970 if (FromPointeeType->isObjectType() && ToPointeeType->isVoidType()) { 971 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 972 ToPointeeType, 973 ToType, Context); 974 return true; 975 } 976 977 // When we're overloading in C, we allow a special kind of pointer 978 // conversion for compatible-but-not-identical pointee types. 979 if (!getLangOptions().CPlusPlus && 980 Context.typesAreCompatible(FromPointeeType, ToPointeeType)) { 981 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 982 ToPointeeType, 983 ToType, Context); 984 return true; 985 } 986 987 // C++ [conv.ptr]p3: 988 // 989 // An rvalue of type "pointer to cv D," where D is a class type, 990 // can be converted to an rvalue of type "pointer to cv B," where 991 // B is a base class (clause 10) of D. If B is an inaccessible 992 // (clause 11) or ambiguous (10.2) base class of D, a program that 993 // necessitates this conversion is ill-formed. The result of the 994 // conversion is a pointer to the base class sub-object of the 995 // derived class object. The null pointer value is converted to 996 // the null pointer value of the destination type. 997 // 998 // Note that we do not check for ambiguity or inaccessibility 999 // here. That is handled by CheckPointerConversion. 1000 if (getLangOptions().CPlusPlus && 1001 FromPointeeType->isRecordType() && ToPointeeType->isRecordType() && 1002 IsDerivedFrom(FromPointeeType, ToPointeeType)) { 1003 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1004 ToPointeeType, 1005 ToType, Context); 1006 return true; 1007 } 1008 1009 return false; 1010} 1011 1012/// isObjCPointerConversion - Determines whether this is an 1013/// Objective-C pointer conversion. Subroutine of IsPointerConversion, 1014/// with the same arguments and return values. 1015bool Sema::isObjCPointerConversion(QualType FromType, QualType ToType, 1016 QualType& ConvertedType, 1017 bool &IncompatibleObjC) { 1018 if (!getLangOptions().ObjC1) 1019 return false; 1020 1021 // First, we handle all conversions on ObjC object pointer types. 1022 const ObjCObjectPointerType* ToObjCPtr = ToType->getAs<ObjCObjectPointerType>(); 1023 const ObjCObjectPointerType *FromObjCPtr = 1024 FromType->getAs<ObjCObjectPointerType>(); 1025 1026 if (ToObjCPtr && FromObjCPtr) { 1027 // Objective C++: We're able to convert between "id" or "Class" and a 1028 // pointer to any interface (in both directions). 1029 if (ToObjCPtr->isObjCBuiltinType() && FromObjCPtr->isObjCBuiltinType()) { 1030 ConvertedType = ToType; 1031 return true; 1032 } 1033 // Conversions with Objective-C's id<...>. 1034 if ((FromObjCPtr->isObjCQualifiedIdType() || 1035 ToObjCPtr->isObjCQualifiedIdType()) && 1036 Context.ObjCQualifiedIdTypesAreCompatible(ToType, FromType, 1037 /*compare=*/false)) { 1038 ConvertedType = ToType; 1039 return true; 1040 } 1041 // Objective C++: We're able to convert from a pointer to an 1042 // interface to a pointer to a different interface. 1043 if (Context.canAssignObjCInterfaces(ToObjCPtr, FromObjCPtr)) { 1044 ConvertedType = ToType; 1045 return true; 1046 } 1047 1048 if (Context.canAssignObjCInterfaces(FromObjCPtr, ToObjCPtr)) { 1049 // Okay: this is some kind of implicit downcast of Objective-C 1050 // interfaces, which is permitted. However, we're going to 1051 // complain about it. 1052 IncompatibleObjC = true; 1053 ConvertedType = FromType; 1054 return true; 1055 } 1056 } 1057 // Beyond this point, both types need to be C pointers or block pointers. 1058 QualType ToPointeeType; 1059 if (const PointerType *ToCPtr = ToType->getAs<PointerType>()) 1060 ToPointeeType = ToCPtr->getPointeeType(); 1061 else if (const BlockPointerType *ToBlockPtr = ToType->getAs<BlockPointerType>()) 1062 ToPointeeType = ToBlockPtr->getPointeeType(); 1063 else 1064 return false; 1065 1066 QualType FromPointeeType; 1067 if (const PointerType *FromCPtr = FromType->getAs<PointerType>()) 1068 FromPointeeType = FromCPtr->getPointeeType(); 1069 else if (const BlockPointerType *FromBlockPtr = FromType->getAs<BlockPointerType>()) 1070 FromPointeeType = FromBlockPtr->getPointeeType(); 1071 else 1072 return false; 1073 1074 // If we have pointers to pointers, recursively check whether this 1075 // is an Objective-C conversion. 1076 if (FromPointeeType->isPointerType() && ToPointeeType->isPointerType() && 1077 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, 1078 IncompatibleObjC)) { 1079 // We always complain about this conversion. 1080 IncompatibleObjC = true; 1081 ConvertedType = ToType; 1082 return true; 1083 } 1084 // If we have pointers to functions or blocks, check whether the only 1085 // differences in the argument and result types are in Objective-C 1086 // pointer conversions. If so, we permit the conversion (but 1087 // complain about it). 1088 const FunctionProtoType *FromFunctionType 1089 = FromPointeeType->getAs<FunctionProtoType>(); 1090 const FunctionProtoType *ToFunctionType 1091 = ToPointeeType->getAs<FunctionProtoType>(); 1092 if (FromFunctionType && ToFunctionType) { 1093 // If the function types are exactly the same, this isn't an 1094 // Objective-C pointer conversion. 1095 if (Context.getCanonicalType(FromPointeeType) 1096 == Context.getCanonicalType(ToPointeeType)) 1097 return false; 1098 1099 // Perform the quick checks that will tell us whether these 1100 // function types are obviously different. 1101 if (FromFunctionType->getNumArgs() != ToFunctionType->getNumArgs() || 1102 FromFunctionType->isVariadic() != ToFunctionType->isVariadic() || 1103 FromFunctionType->getTypeQuals() != ToFunctionType->getTypeQuals()) 1104 return false; 1105 1106 bool HasObjCConversion = false; 1107 if (Context.getCanonicalType(FromFunctionType->getResultType()) 1108 == Context.getCanonicalType(ToFunctionType->getResultType())) { 1109 // Okay, the types match exactly. Nothing to do. 1110 } else if (isObjCPointerConversion(FromFunctionType->getResultType(), 1111 ToFunctionType->getResultType(), 1112 ConvertedType, IncompatibleObjC)) { 1113 // Okay, we have an Objective-C pointer conversion. 1114 HasObjCConversion = true; 1115 } else { 1116 // Function types are too different. Abort. 1117 return false; 1118 } 1119 1120 // Check argument types. 1121 for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumArgs(); 1122 ArgIdx != NumArgs; ++ArgIdx) { 1123 QualType FromArgType = FromFunctionType->getArgType(ArgIdx); 1124 QualType ToArgType = ToFunctionType->getArgType(ArgIdx); 1125 if (Context.getCanonicalType(FromArgType) 1126 == Context.getCanonicalType(ToArgType)) { 1127 // Okay, the types match exactly. Nothing to do. 1128 } else if (isObjCPointerConversion(FromArgType, ToArgType, 1129 ConvertedType, IncompatibleObjC)) { 1130 // Okay, we have an Objective-C pointer conversion. 1131 HasObjCConversion = true; 1132 } else { 1133 // Argument types are too different. Abort. 1134 return false; 1135 } 1136 } 1137 1138 if (HasObjCConversion) { 1139 // We had an Objective-C conversion. Allow this pointer 1140 // conversion, but complain about it. 1141 ConvertedType = ToType; 1142 IncompatibleObjC = true; 1143 return true; 1144 } 1145 } 1146 1147 return false; 1148} 1149 1150/// CheckPointerConversion - Check the pointer conversion from the 1151/// expression From to the type ToType. This routine checks for 1152/// ambiguous or inaccessible derived-to-base pointer 1153/// conversions for which IsPointerConversion has already returned 1154/// true. It returns true and produces a diagnostic if there was an 1155/// error, or returns false otherwise. 1156bool Sema::CheckPointerConversion(Expr *From, QualType ToType, 1157 CastExpr::CastKind &Kind) { 1158 QualType FromType = From->getType(); 1159 1160 if (const PointerType *FromPtrType = FromType->getAs<PointerType>()) 1161 if (const PointerType *ToPtrType = ToType->getAs<PointerType>()) { 1162 QualType FromPointeeType = FromPtrType->getPointeeType(), 1163 ToPointeeType = ToPtrType->getPointeeType(); 1164 1165 if (FromPointeeType->isRecordType() && 1166 ToPointeeType->isRecordType()) { 1167 // We must have a derived-to-base conversion. Check an 1168 // ambiguous or inaccessible conversion. 1169 if (CheckDerivedToBaseConversion(FromPointeeType, ToPointeeType, 1170 From->getExprLoc(), 1171 From->getSourceRange())) 1172 return true; 1173 1174 // The conversion was successful. 1175 Kind = CastExpr::CK_DerivedToBase; 1176 } 1177 } 1178 if (const ObjCObjectPointerType *FromPtrType = 1179 FromType->getAs<ObjCObjectPointerType>()) 1180 if (const ObjCObjectPointerType *ToPtrType = 1181 ToType->getAs<ObjCObjectPointerType>()) { 1182 // Objective-C++ conversions are always okay. 1183 // FIXME: We should have a different class of conversions for the 1184 // Objective-C++ implicit conversions. 1185 if (FromPtrType->isObjCBuiltinType() || ToPtrType->isObjCBuiltinType()) 1186 return false; 1187 1188 } 1189 return false; 1190} 1191 1192/// IsMemberPointerConversion - Determines whether the conversion of the 1193/// expression From, which has the (possibly adjusted) type FromType, can be 1194/// converted to the type ToType via a member pointer conversion (C++ 4.11). 1195/// If so, returns true and places the converted type (that might differ from 1196/// ToType in its cv-qualifiers at some level) into ConvertedType. 1197bool Sema::IsMemberPointerConversion(Expr *From, QualType FromType, 1198 QualType ToType, 1199 bool InOverloadResolution, 1200 QualType &ConvertedType) { 1201 const MemberPointerType *ToTypePtr = ToType->getAs<MemberPointerType>(); 1202 if (!ToTypePtr) 1203 return false; 1204 1205 // A null pointer constant can be converted to a member pointer (C++ 4.11p1) 1206 if (From->isNullPointerConstant(Context, 1207 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull 1208 : Expr::NPC_ValueDependentIsNull)) { 1209 ConvertedType = ToType; 1210 return true; 1211 } 1212 1213 // Otherwise, both types have to be member pointers. 1214 const MemberPointerType *FromTypePtr = FromType->getAs<MemberPointerType>(); 1215 if (!FromTypePtr) 1216 return false; 1217 1218 // A pointer to member of B can be converted to a pointer to member of D, 1219 // where D is derived from B (C++ 4.11p2). 1220 QualType FromClass(FromTypePtr->getClass(), 0); 1221 QualType ToClass(ToTypePtr->getClass(), 0); 1222 // FIXME: What happens when these are dependent? Is this function even called? 1223 1224 if (IsDerivedFrom(ToClass, FromClass)) { 1225 ConvertedType = Context.getMemberPointerType(FromTypePtr->getPointeeType(), 1226 ToClass.getTypePtr()); 1227 return true; 1228 } 1229 1230 return false; 1231} 1232 1233/// CheckMemberPointerConversion - Check the member pointer conversion from the 1234/// expression From to the type ToType. This routine checks for ambiguous or 1235/// virtual (FIXME: or inaccessible) base-to-derived member pointer conversions 1236/// for which IsMemberPointerConversion has already returned true. It returns 1237/// true and produces a diagnostic if there was an error, or returns false 1238/// otherwise. 1239bool Sema::CheckMemberPointerConversion(Expr *From, QualType ToType, 1240 CastExpr::CastKind &Kind) { 1241 QualType FromType = From->getType(); 1242 const MemberPointerType *FromPtrType = FromType->getAs<MemberPointerType>(); 1243 if (!FromPtrType) { 1244 // This must be a null pointer to member pointer conversion 1245 assert(From->isNullPointerConstant(Context, 1246 Expr::NPC_ValueDependentIsNull) && 1247 "Expr must be null pointer constant!"); 1248 Kind = CastExpr::CK_NullToMemberPointer; 1249 return false; 1250 } 1251 1252 const MemberPointerType *ToPtrType = ToType->getAs<MemberPointerType>(); 1253 assert(ToPtrType && "No member pointer cast has a target type " 1254 "that is not a member pointer."); 1255 1256 QualType FromClass = QualType(FromPtrType->getClass(), 0); 1257 QualType ToClass = QualType(ToPtrType->getClass(), 0); 1258 1259 // FIXME: What about dependent types? 1260 assert(FromClass->isRecordType() && "Pointer into non-class."); 1261 assert(ToClass->isRecordType() && "Pointer into non-class."); 1262 1263 CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/false, 1264 /*DetectVirtual=*/true); 1265 bool DerivationOkay = IsDerivedFrom(ToClass, FromClass, Paths); 1266 assert(DerivationOkay && 1267 "Should not have been called if derivation isn't OK."); 1268 (void)DerivationOkay; 1269 1270 if (Paths.isAmbiguous(Context.getCanonicalType(FromClass). 1271 getUnqualifiedType())) { 1272 // Derivation is ambiguous. Redo the check to find the exact paths. 1273 Paths.clear(); 1274 Paths.setRecordingPaths(true); 1275 bool StillOkay = IsDerivedFrom(ToClass, FromClass, Paths); 1276 assert(StillOkay && "Derivation changed due to quantum fluctuation."); 1277 (void)StillOkay; 1278 1279 std::string PathDisplayStr = getAmbiguousPathsDisplayString(Paths); 1280 Diag(From->getExprLoc(), diag::err_ambiguous_memptr_conv) 1281 << 0 << FromClass << ToClass << PathDisplayStr << From->getSourceRange(); 1282 return true; 1283 } 1284 1285 if (const RecordType *VBase = Paths.getDetectedVirtual()) { 1286 Diag(From->getExprLoc(), diag::err_memptr_conv_via_virtual) 1287 << FromClass << ToClass << QualType(VBase, 0) 1288 << From->getSourceRange(); 1289 return true; 1290 } 1291 1292 // Must be a base to derived member conversion. 1293 Kind = CastExpr::CK_BaseToDerivedMemberPointer; 1294 return false; 1295} 1296 1297/// IsQualificationConversion - Determines whether the conversion from 1298/// an rvalue of type FromType to ToType is a qualification conversion 1299/// (C++ 4.4). 1300bool 1301Sema::IsQualificationConversion(QualType FromType, QualType ToType) { 1302 FromType = Context.getCanonicalType(FromType); 1303 ToType = Context.getCanonicalType(ToType); 1304 1305 // If FromType and ToType are the same type, this is not a 1306 // qualification conversion. 1307 if (FromType == ToType) 1308 return false; 1309 1310 // (C++ 4.4p4): 1311 // A conversion can add cv-qualifiers at levels other than the first 1312 // in multi-level pointers, subject to the following rules: [...] 1313 bool PreviousToQualsIncludeConst = true; 1314 bool UnwrappedAnyPointer = false; 1315 while (UnwrapSimilarPointerTypes(FromType, ToType)) { 1316 // Within each iteration of the loop, we check the qualifiers to 1317 // determine if this still looks like a qualification 1318 // conversion. Then, if all is well, we unwrap one more level of 1319 // pointers or pointers-to-members and do it all again 1320 // until there are no more pointers or pointers-to-members left to 1321 // unwrap. 1322 UnwrappedAnyPointer = true; 1323 1324 // -- for every j > 0, if const is in cv 1,j then const is in cv 1325 // 2,j, and similarly for volatile. 1326 if (!ToType.isAtLeastAsQualifiedAs(FromType)) 1327 return false; 1328 1329 // -- if the cv 1,j and cv 2,j are different, then const is in 1330 // every cv for 0 < k < j. 1331 if (FromType.getCVRQualifiers() != ToType.getCVRQualifiers() 1332 && !PreviousToQualsIncludeConst) 1333 return false; 1334 1335 // Keep track of whether all prior cv-qualifiers in the "to" type 1336 // include const. 1337 PreviousToQualsIncludeConst 1338 = PreviousToQualsIncludeConst && ToType.isConstQualified(); 1339 } 1340 1341 // We are left with FromType and ToType being the pointee types 1342 // after unwrapping the original FromType and ToType the same number 1343 // of types. If we unwrapped any pointers, and if FromType and 1344 // ToType have the same unqualified type (since we checked 1345 // qualifiers above), then this is a qualification conversion. 1346 return UnwrappedAnyPointer && 1347 FromType.getUnqualifiedType() == ToType.getUnqualifiedType(); 1348} 1349 1350/// \brief Given a function template or function, extract the function template 1351/// declaration (if any) and the underlying function declaration. 1352template<typename T> 1353static void GetFunctionAndTemplate(AnyFunctionDecl Orig, T *&Function, 1354 FunctionTemplateDecl *&FunctionTemplate) { 1355 FunctionTemplate = dyn_cast<FunctionTemplateDecl>(Orig); 1356 if (FunctionTemplate) 1357 Function = cast<T>(FunctionTemplate->getTemplatedDecl()); 1358 else 1359 Function = cast<T>(Orig); 1360} 1361 1362/// Determines whether there is a user-defined conversion sequence 1363/// (C++ [over.ics.user]) that converts expression From to the type 1364/// ToType. If such a conversion exists, User will contain the 1365/// user-defined conversion sequence that performs such a conversion 1366/// and this routine will return true. Otherwise, this routine returns 1367/// false and User is unspecified. 1368/// 1369/// \param AllowConversionFunctions true if the conversion should 1370/// consider conversion functions at all. If false, only constructors 1371/// will be considered. 1372/// 1373/// \param AllowExplicit true if the conversion should consider C++0x 1374/// "explicit" conversion functions as well as non-explicit conversion 1375/// functions (C++0x [class.conv.fct]p2). 1376/// 1377/// \param ForceRValue true if the expression should be treated as an rvalue 1378/// for overload resolution. 1379/// \param UserCast true if looking for user defined conversion for a static 1380/// cast. 1381Sema::OverloadingResult Sema::IsUserDefinedConversion( 1382 Expr *From, QualType ToType, 1383 UserDefinedConversionSequence& User, 1384 OverloadCandidateSet& CandidateSet, 1385 bool AllowConversionFunctions, 1386 bool AllowExplicit, bool ForceRValue, 1387 bool UserCast) { 1388 if (const RecordType *ToRecordType = ToType->getAs<RecordType>()) { 1389 if (CXXRecordDecl *ToRecordDecl 1390 = dyn_cast<CXXRecordDecl>(ToRecordType->getDecl())) { 1391 // C++ [over.match.ctor]p1: 1392 // When objects of class type are direct-initialized (8.5), or 1393 // copy-initialized from an expression of the same or a 1394 // derived class type (8.5), overload resolution selects the 1395 // constructor. [...] For copy-initialization, the candidate 1396 // functions are all the converting constructors (12.3.1) of 1397 // that class. The argument list is the expression-list within 1398 // the parentheses of the initializer. 1399 DeclarationName ConstructorName 1400 = Context.DeclarationNames.getCXXConstructorName( 1401 Context.getCanonicalType(ToType).getUnqualifiedType()); 1402 DeclContext::lookup_iterator Con, ConEnd; 1403 for (llvm::tie(Con, ConEnd) 1404 = ToRecordDecl->lookup(ConstructorName); 1405 Con != ConEnd; ++Con) { 1406 // Find the constructor (which may be a template). 1407 CXXConstructorDecl *Constructor = 0; 1408 FunctionTemplateDecl *ConstructorTmpl 1409 = dyn_cast<FunctionTemplateDecl>(*Con); 1410 if (ConstructorTmpl) 1411 Constructor 1412 = cast<CXXConstructorDecl>(ConstructorTmpl->getTemplatedDecl()); 1413 else 1414 Constructor = cast<CXXConstructorDecl>(*Con); 1415 1416 if (!Constructor->isInvalidDecl() && 1417 Constructor->isConvertingConstructor(AllowExplicit)) { 1418 if (ConstructorTmpl) 1419 AddTemplateOverloadCandidate(ConstructorTmpl, false, 0, 0, &From, 1420 1, CandidateSet, 1421 /*SuppressUserConversions=*/!UserCast, 1422 ForceRValue); 1423 else 1424 // Allow one user-defined conversion when user specifies a 1425 // From->ToType conversion via an static cast (c-style, etc). 1426 AddOverloadCandidate(Constructor, &From, 1, CandidateSet, 1427 /*SuppressUserConversions=*/!UserCast, 1428 ForceRValue); 1429 } 1430 } 1431 } 1432 } 1433 1434 if (!AllowConversionFunctions) { 1435 // Don't allow any conversion functions to enter the overload set. 1436 } else if (RequireCompleteType(From->getLocStart(), From->getType(), 1437 PDiag(0) 1438 << From->getSourceRange())) { 1439 // No conversion functions from incomplete types. 1440 } else if (const RecordType *FromRecordType 1441 = From->getType()->getAs<RecordType>()) { 1442 if (CXXRecordDecl *FromRecordDecl 1443 = dyn_cast<CXXRecordDecl>(FromRecordType->getDecl())) { 1444 // Add all of the conversion functions as candidates. 1445 OverloadedFunctionDecl *Conversions 1446 = FromRecordDecl->getVisibleConversionFunctions(); 1447 for (OverloadedFunctionDecl::function_iterator Func 1448 = Conversions->function_begin(); 1449 Func != Conversions->function_end(); ++Func) { 1450 CXXConversionDecl *Conv; 1451 FunctionTemplateDecl *ConvTemplate; 1452 GetFunctionAndTemplate(*Func, Conv, ConvTemplate); 1453 if (ConvTemplate) 1454 Conv = dyn_cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 1455 else 1456 Conv = dyn_cast<CXXConversionDecl>(*Func); 1457 1458 if (AllowExplicit || !Conv->isExplicit()) { 1459 if (ConvTemplate) 1460 AddTemplateConversionCandidate(ConvTemplate, From, ToType, 1461 CandidateSet); 1462 else 1463 AddConversionCandidate(Conv, From, ToType, CandidateSet); 1464 } 1465 } 1466 } 1467 } 1468 1469 OverloadCandidateSet::iterator Best; 1470 switch (BestViableFunction(CandidateSet, From->getLocStart(), Best)) { 1471 case OR_Success: 1472 // Record the standard conversion we used and the conversion function. 1473 if (CXXConstructorDecl *Constructor 1474 = dyn_cast<CXXConstructorDecl>(Best->Function)) { 1475 // C++ [over.ics.user]p1: 1476 // If the user-defined conversion is specified by a 1477 // constructor (12.3.1), the initial standard conversion 1478 // sequence converts the source type to the type required by 1479 // the argument of the constructor. 1480 // 1481 // FIXME: What about ellipsis conversions? 1482 QualType ThisType = Constructor->getThisType(Context); 1483 User.Before = Best->Conversions[0].Standard; 1484 User.ConversionFunction = Constructor; 1485 User.After.setAsIdentityConversion(); 1486 User.After.FromTypePtr 1487 = ThisType->getAs<PointerType>()->getPointeeType().getAsOpaquePtr(); 1488 User.After.ToTypePtr = ToType.getAsOpaquePtr(); 1489 return OR_Success; 1490 } else if (CXXConversionDecl *Conversion 1491 = dyn_cast<CXXConversionDecl>(Best->Function)) { 1492 // C++ [over.ics.user]p1: 1493 // 1494 // [...] If the user-defined conversion is specified by a 1495 // conversion function (12.3.2), the initial standard 1496 // conversion sequence converts the source type to the 1497 // implicit object parameter of the conversion function. 1498 User.Before = Best->Conversions[0].Standard; 1499 User.ConversionFunction = Conversion; 1500 1501 // C++ [over.ics.user]p2: 1502 // The second standard conversion sequence converts the 1503 // result of the user-defined conversion to the target type 1504 // for the sequence. Since an implicit conversion sequence 1505 // is an initialization, the special rules for 1506 // initialization by user-defined conversion apply when 1507 // selecting the best user-defined conversion for a 1508 // user-defined conversion sequence (see 13.3.3 and 1509 // 13.3.3.1). 1510 User.After = Best->FinalConversion; 1511 return OR_Success; 1512 } else { 1513 assert(false && "Not a constructor or conversion function?"); 1514 return OR_No_Viable_Function; 1515 } 1516 1517 case OR_No_Viable_Function: 1518 return OR_No_Viable_Function; 1519 case OR_Deleted: 1520 // No conversion here! We're done. 1521 return OR_Deleted; 1522 1523 case OR_Ambiguous: 1524 return OR_Ambiguous; 1525 } 1526 1527 return OR_No_Viable_Function; 1528} 1529 1530bool 1531Sema::DiagnoseAmbiguousUserDefinedConversion(Expr *From, QualType ToType) { 1532 ImplicitConversionSequence ICS; 1533 OverloadCandidateSet CandidateSet; 1534 OverloadingResult OvResult = 1535 IsUserDefinedConversion(From, ToType, ICS.UserDefined, 1536 CandidateSet, true, false, false); 1537 if (OvResult != OR_Ambiguous) 1538 return false; 1539 Diag(From->getSourceRange().getBegin(), 1540 diag::err_typecheck_ambiguous_condition) 1541 << From->getType() << ToType << From->getSourceRange(); 1542 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 1543 return true; 1544} 1545 1546/// CompareImplicitConversionSequences - Compare two implicit 1547/// conversion sequences to determine whether one is better than the 1548/// other or if they are indistinguishable (C++ 13.3.3.2). 1549ImplicitConversionSequence::CompareKind 1550Sema::CompareImplicitConversionSequences(const ImplicitConversionSequence& ICS1, 1551 const ImplicitConversionSequence& ICS2) 1552{ 1553 // (C++ 13.3.3.2p2): When comparing the basic forms of implicit 1554 // conversion sequences (as defined in 13.3.3.1) 1555 // -- a standard conversion sequence (13.3.3.1.1) is a better 1556 // conversion sequence than a user-defined conversion sequence or 1557 // an ellipsis conversion sequence, and 1558 // -- a user-defined conversion sequence (13.3.3.1.2) is a better 1559 // conversion sequence than an ellipsis conversion sequence 1560 // (13.3.3.1.3). 1561 // 1562 if (ICS1.ConversionKind < ICS2.ConversionKind) 1563 return ImplicitConversionSequence::Better; 1564 else if (ICS2.ConversionKind < ICS1.ConversionKind) 1565 return ImplicitConversionSequence::Worse; 1566 1567 // Two implicit conversion sequences of the same form are 1568 // indistinguishable conversion sequences unless one of the 1569 // following rules apply: (C++ 13.3.3.2p3): 1570 if (ICS1.ConversionKind == ImplicitConversionSequence::StandardConversion) 1571 return CompareStandardConversionSequences(ICS1.Standard, ICS2.Standard); 1572 else if (ICS1.ConversionKind == 1573 ImplicitConversionSequence::UserDefinedConversion) { 1574 // User-defined conversion sequence U1 is a better conversion 1575 // sequence than another user-defined conversion sequence U2 if 1576 // they contain the same user-defined conversion function or 1577 // constructor and if the second standard conversion sequence of 1578 // U1 is better than the second standard conversion sequence of 1579 // U2 (C++ 13.3.3.2p3). 1580 if (ICS1.UserDefined.ConversionFunction == 1581 ICS2.UserDefined.ConversionFunction) 1582 return CompareStandardConversionSequences(ICS1.UserDefined.After, 1583 ICS2.UserDefined.After); 1584 } 1585 1586 return ImplicitConversionSequence::Indistinguishable; 1587} 1588 1589/// CompareStandardConversionSequences - Compare two standard 1590/// conversion sequences to determine whether one is better than the 1591/// other or if they are indistinguishable (C++ 13.3.3.2p3). 1592ImplicitConversionSequence::CompareKind 1593Sema::CompareStandardConversionSequences(const StandardConversionSequence& SCS1, 1594 const StandardConversionSequence& SCS2) 1595{ 1596 // Standard conversion sequence S1 is a better conversion sequence 1597 // than standard conversion sequence S2 if (C++ 13.3.3.2p3): 1598 1599 // -- S1 is a proper subsequence of S2 (comparing the conversion 1600 // sequences in the canonical form defined by 13.3.3.1.1, 1601 // excluding any Lvalue Transformation; the identity conversion 1602 // sequence is considered to be a subsequence of any 1603 // non-identity conversion sequence) or, if not that, 1604 if (SCS1.Second == SCS2.Second && SCS1.Third == SCS2.Third) 1605 // Neither is a proper subsequence of the other. Do nothing. 1606 ; 1607 else if ((SCS1.Second == ICK_Identity && SCS1.Third == SCS2.Third) || 1608 (SCS1.Third == ICK_Identity && SCS1.Second == SCS2.Second) || 1609 (SCS1.Second == ICK_Identity && 1610 SCS1.Third == ICK_Identity)) 1611 // SCS1 is a proper subsequence of SCS2. 1612 return ImplicitConversionSequence::Better; 1613 else if ((SCS2.Second == ICK_Identity && SCS2.Third == SCS1.Third) || 1614 (SCS2.Third == ICK_Identity && SCS2.Second == SCS1.Second) || 1615 (SCS2.Second == ICK_Identity && 1616 SCS2.Third == ICK_Identity)) 1617 // SCS2 is a proper subsequence of SCS1. 1618 return ImplicitConversionSequence::Worse; 1619 1620 // -- the rank of S1 is better than the rank of S2 (by the rules 1621 // defined below), or, if not that, 1622 ImplicitConversionRank Rank1 = SCS1.getRank(); 1623 ImplicitConversionRank Rank2 = SCS2.getRank(); 1624 if (Rank1 < Rank2) 1625 return ImplicitConversionSequence::Better; 1626 else if (Rank2 < Rank1) 1627 return ImplicitConversionSequence::Worse; 1628 1629 // (C++ 13.3.3.2p4): Two conversion sequences with the same rank 1630 // are indistinguishable unless one of the following rules 1631 // applies: 1632 1633 // A conversion that is not a conversion of a pointer, or 1634 // pointer to member, to bool is better than another conversion 1635 // that is such a conversion. 1636 if (SCS1.isPointerConversionToBool() != SCS2.isPointerConversionToBool()) 1637 return SCS2.isPointerConversionToBool() 1638 ? ImplicitConversionSequence::Better 1639 : ImplicitConversionSequence::Worse; 1640 1641 // C++ [over.ics.rank]p4b2: 1642 // 1643 // If class B is derived directly or indirectly from class A, 1644 // conversion of B* to A* is better than conversion of B* to 1645 // void*, and conversion of A* to void* is better than conversion 1646 // of B* to void*. 1647 bool SCS1ConvertsToVoid 1648 = SCS1.isPointerConversionToVoidPointer(Context); 1649 bool SCS2ConvertsToVoid 1650 = SCS2.isPointerConversionToVoidPointer(Context); 1651 if (SCS1ConvertsToVoid != SCS2ConvertsToVoid) { 1652 // Exactly one of the conversion sequences is a conversion to 1653 // a void pointer; it's the worse conversion. 1654 return SCS2ConvertsToVoid ? ImplicitConversionSequence::Better 1655 : ImplicitConversionSequence::Worse; 1656 } else if (!SCS1ConvertsToVoid && !SCS2ConvertsToVoid) { 1657 // Neither conversion sequence converts to a void pointer; compare 1658 // their derived-to-base conversions. 1659 if (ImplicitConversionSequence::CompareKind DerivedCK 1660 = CompareDerivedToBaseConversions(SCS1, SCS2)) 1661 return DerivedCK; 1662 } else if (SCS1ConvertsToVoid && SCS2ConvertsToVoid) { 1663 // Both conversion sequences are conversions to void 1664 // pointers. Compare the source types to determine if there's an 1665 // inheritance relationship in their sources. 1666 QualType FromType1 = QualType::getFromOpaquePtr(SCS1.FromTypePtr); 1667 QualType FromType2 = QualType::getFromOpaquePtr(SCS2.FromTypePtr); 1668 1669 // Adjust the types we're converting from via the array-to-pointer 1670 // conversion, if we need to. 1671 if (SCS1.First == ICK_Array_To_Pointer) 1672 FromType1 = Context.getArrayDecayedType(FromType1); 1673 if (SCS2.First == ICK_Array_To_Pointer) 1674 FromType2 = Context.getArrayDecayedType(FromType2); 1675 1676 QualType FromPointee1 1677 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1678 QualType FromPointee2 1679 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1680 1681 if (IsDerivedFrom(FromPointee2, FromPointee1)) 1682 return ImplicitConversionSequence::Better; 1683 else if (IsDerivedFrom(FromPointee1, FromPointee2)) 1684 return ImplicitConversionSequence::Worse; 1685 1686 // Objective-C++: If one interface is more specific than the 1687 // other, it is the better one. 1688 const ObjCInterfaceType* FromIface1 = FromPointee1->getAs<ObjCInterfaceType>(); 1689 const ObjCInterfaceType* FromIface2 = FromPointee2->getAs<ObjCInterfaceType>(); 1690 if (FromIface1 && FromIface1) { 1691 if (Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 1692 return ImplicitConversionSequence::Better; 1693 else if (Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 1694 return ImplicitConversionSequence::Worse; 1695 } 1696 } 1697 1698 // Compare based on qualification conversions (C++ 13.3.3.2p3, 1699 // bullet 3). 1700 if (ImplicitConversionSequence::CompareKind QualCK 1701 = CompareQualificationConversions(SCS1, SCS2)) 1702 return QualCK; 1703 1704 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding) { 1705 // C++0x [over.ics.rank]p3b4: 1706 // -- S1 and S2 are reference bindings (8.5.3) and neither refers to an 1707 // implicit object parameter of a non-static member function declared 1708 // without a ref-qualifier, and S1 binds an rvalue reference to an 1709 // rvalue and S2 binds an lvalue reference. 1710 // FIXME: We don't know if we're dealing with the implicit object parameter, 1711 // or if the member function in this case has a ref qualifier. 1712 // (Of course, we don't have ref qualifiers yet.) 1713 if (SCS1.RRefBinding != SCS2.RRefBinding) 1714 return SCS1.RRefBinding ? ImplicitConversionSequence::Better 1715 : ImplicitConversionSequence::Worse; 1716 1717 // C++ [over.ics.rank]p3b4: 1718 // -- S1 and S2 are reference bindings (8.5.3), and the types to 1719 // which the references refer are the same type except for 1720 // top-level cv-qualifiers, and the type to which the reference 1721 // initialized by S2 refers is more cv-qualified than the type 1722 // to which the reference initialized by S1 refers. 1723 QualType T1 = QualType::getFromOpaquePtr(SCS1.ToTypePtr); 1724 QualType T2 = QualType::getFromOpaquePtr(SCS2.ToTypePtr); 1725 T1 = Context.getCanonicalType(T1); 1726 T2 = Context.getCanonicalType(T2); 1727 if (T1.getUnqualifiedType() == T2.getUnqualifiedType()) { 1728 if (T2.isMoreQualifiedThan(T1)) 1729 return ImplicitConversionSequence::Better; 1730 else if (T1.isMoreQualifiedThan(T2)) 1731 return ImplicitConversionSequence::Worse; 1732 } 1733 } 1734 1735 return ImplicitConversionSequence::Indistinguishable; 1736} 1737 1738/// CompareQualificationConversions - Compares two standard conversion 1739/// sequences to determine whether they can be ranked based on their 1740/// qualification conversions (C++ 13.3.3.2p3 bullet 3). 1741ImplicitConversionSequence::CompareKind 1742Sema::CompareQualificationConversions(const StandardConversionSequence& SCS1, 1743 const StandardConversionSequence& SCS2) { 1744 // C++ 13.3.3.2p3: 1745 // -- S1 and S2 differ only in their qualification conversion and 1746 // yield similar types T1 and T2 (C++ 4.4), respectively, and the 1747 // cv-qualification signature of type T1 is a proper subset of 1748 // the cv-qualification signature of type T2, and S1 is not the 1749 // deprecated string literal array-to-pointer conversion (4.2). 1750 if (SCS1.First != SCS2.First || SCS1.Second != SCS2.Second || 1751 SCS1.Third != SCS2.Third || SCS1.Third != ICK_Qualification) 1752 return ImplicitConversionSequence::Indistinguishable; 1753 1754 // FIXME: the example in the standard doesn't use a qualification 1755 // conversion (!) 1756 QualType T1 = QualType::getFromOpaquePtr(SCS1.ToTypePtr); 1757 QualType T2 = QualType::getFromOpaquePtr(SCS2.ToTypePtr); 1758 T1 = Context.getCanonicalType(T1); 1759 T2 = Context.getCanonicalType(T2); 1760 1761 // If the types are the same, we won't learn anything by unwrapped 1762 // them. 1763 if (T1.getUnqualifiedType() == T2.getUnqualifiedType()) 1764 return ImplicitConversionSequence::Indistinguishable; 1765 1766 ImplicitConversionSequence::CompareKind Result 1767 = ImplicitConversionSequence::Indistinguishable; 1768 while (UnwrapSimilarPointerTypes(T1, T2)) { 1769 // Within each iteration of the loop, we check the qualifiers to 1770 // determine if this still looks like a qualification 1771 // conversion. Then, if all is well, we unwrap one more level of 1772 // pointers or pointers-to-members and do it all again 1773 // until there are no more pointers or pointers-to-members left 1774 // to unwrap. This essentially mimics what 1775 // IsQualificationConversion does, but here we're checking for a 1776 // strict subset of qualifiers. 1777 if (T1.getCVRQualifiers() == T2.getCVRQualifiers()) 1778 // The qualifiers are the same, so this doesn't tell us anything 1779 // about how the sequences rank. 1780 ; 1781 else if (T2.isMoreQualifiedThan(T1)) { 1782 // T1 has fewer qualifiers, so it could be the better sequence. 1783 if (Result == ImplicitConversionSequence::Worse) 1784 // Neither has qualifiers that are a subset of the other's 1785 // qualifiers. 1786 return ImplicitConversionSequence::Indistinguishable; 1787 1788 Result = ImplicitConversionSequence::Better; 1789 } else if (T1.isMoreQualifiedThan(T2)) { 1790 // T2 has fewer qualifiers, so it could be the better sequence. 1791 if (Result == ImplicitConversionSequence::Better) 1792 // Neither has qualifiers that are a subset of the other's 1793 // qualifiers. 1794 return ImplicitConversionSequence::Indistinguishable; 1795 1796 Result = ImplicitConversionSequence::Worse; 1797 } else { 1798 // Qualifiers are disjoint. 1799 return ImplicitConversionSequence::Indistinguishable; 1800 } 1801 1802 // If the types after this point are equivalent, we're done. 1803 if (T1.getUnqualifiedType() == T2.getUnqualifiedType()) 1804 break; 1805 } 1806 1807 // Check that the winning standard conversion sequence isn't using 1808 // the deprecated string literal array to pointer conversion. 1809 switch (Result) { 1810 case ImplicitConversionSequence::Better: 1811 if (SCS1.Deprecated) 1812 Result = ImplicitConversionSequence::Indistinguishable; 1813 break; 1814 1815 case ImplicitConversionSequence::Indistinguishable: 1816 break; 1817 1818 case ImplicitConversionSequence::Worse: 1819 if (SCS2.Deprecated) 1820 Result = ImplicitConversionSequence::Indistinguishable; 1821 break; 1822 } 1823 1824 return Result; 1825} 1826 1827/// CompareDerivedToBaseConversions - Compares two standard conversion 1828/// sequences to determine whether they can be ranked based on their 1829/// various kinds of derived-to-base conversions (C++ 1830/// [over.ics.rank]p4b3). As part of these checks, we also look at 1831/// conversions between Objective-C interface types. 1832ImplicitConversionSequence::CompareKind 1833Sema::CompareDerivedToBaseConversions(const StandardConversionSequence& SCS1, 1834 const StandardConversionSequence& SCS2) { 1835 QualType FromType1 = QualType::getFromOpaquePtr(SCS1.FromTypePtr); 1836 QualType ToType1 = QualType::getFromOpaquePtr(SCS1.ToTypePtr); 1837 QualType FromType2 = QualType::getFromOpaquePtr(SCS2.FromTypePtr); 1838 QualType ToType2 = QualType::getFromOpaquePtr(SCS2.ToTypePtr); 1839 1840 // Adjust the types we're converting from via the array-to-pointer 1841 // conversion, if we need to. 1842 if (SCS1.First == ICK_Array_To_Pointer) 1843 FromType1 = Context.getArrayDecayedType(FromType1); 1844 if (SCS2.First == ICK_Array_To_Pointer) 1845 FromType2 = Context.getArrayDecayedType(FromType2); 1846 1847 // Canonicalize all of the types. 1848 FromType1 = Context.getCanonicalType(FromType1); 1849 ToType1 = Context.getCanonicalType(ToType1); 1850 FromType2 = Context.getCanonicalType(FromType2); 1851 ToType2 = Context.getCanonicalType(ToType2); 1852 1853 // C++ [over.ics.rank]p4b3: 1854 // 1855 // If class B is derived directly or indirectly from class A and 1856 // class C is derived directly or indirectly from B, 1857 // 1858 // For Objective-C, we let A, B, and C also be Objective-C 1859 // interfaces. 1860 1861 // Compare based on pointer conversions. 1862 if (SCS1.Second == ICK_Pointer_Conversion && 1863 SCS2.Second == ICK_Pointer_Conversion && 1864 /*FIXME: Remove if Objective-C id conversions get their own rank*/ 1865 FromType1->isPointerType() && FromType2->isPointerType() && 1866 ToType1->isPointerType() && ToType2->isPointerType()) { 1867 QualType FromPointee1 1868 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1869 QualType ToPointee1 1870 = ToType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1871 QualType FromPointee2 1872 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1873 QualType ToPointee2 1874 = ToType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 1875 1876 const ObjCInterfaceType* FromIface1 = FromPointee1->getAs<ObjCInterfaceType>(); 1877 const ObjCInterfaceType* FromIface2 = FromPointee2->getAs<ObjCInterfaceType>(); 1878 const ObjCInterfaceType* ToIface1 = ToPointee1->getAs<ObjCInterfaceType>(); 1879 const ObjCInterfaceType* ToIface2 = ToPointee2->getAs<ObjCInterfaceType>(); 1880 1881 // -- conversion of C* to B* is better than conversion of C* to A*, 1882 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 1883 if (IsDerivedFrom(ToPointee1, ToPointee2)) 1884 return ImplicitConversionSequence::Better; 1885 else if (IsDerivedFrom(ToPointee2, ToPointee1)) 1886 return ImplicitConversionSequence::Worse; 1887 1888 if (ToIface1 && ToIface2) { 1889 if (Context.canAssignObjCInterfaces(ToIface2, ToIface1)) 1890 return ImplicitConversionSequence::Better; 1891 else if (Context.canAssignObjCInterfaces(ToIface1, ToIface2)) 1892 return ImplicitConversionSequence::Worse; 1893 } 1894 } 1895 1896 // -- conversion of B* to A* is better than conversion of C* to A*, 1897 if (FromPointee1 != FromPointee2 && ToPointee1 == ToPointee2) { 1898 if (IsDerivedFrom(FromPointee2, FromPointee1)) 1899 return ImplicitConversionSequence::Better; 1900 else if (IsDerivedFrom(FromPointee1, FromPointee2)) 1901 return ImplicitConversionSequence::Worse; 1902 1903 if (FromIface1 && FromIface2) { 1904 if (Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 1905 return ImplicitConversionSequence::Better; 1906 else if (Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 1907 return ImplicitConversionSequence::Worse; 1908 } 1909 } 1910 } 1911 1912 // Compare based on reference bindings. 1913 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding && 1914 SCS1.Second == ICK_Derived_To_Base) { 1915 // -- binding of an expression of type C to a reference of type 1916 // B& is better than binding an expression of type C to a 1917 // reference of type A&, 1918 if (FromType1.getUnqualifiedType() == FromType2.getUnqualifiedType() && 1919 ToType1.getUnqualifiedType() != ToType2.getUnqualifiedType()) { 1920 if (IsDerivedFrom(ToType1, ToType2)) 1921 return ImplicitConversionSequence::Better; 1922 else if (IsDerivedFrom(ToType2, ToType1)) 1923 return ImplicitConversionSequence::Worse; 1924 } 1925 1926 // -- binding of an expression of type B to a reference of type 1927 // A& is better than binding an expression of type C to a 1928 // reference of type A&, 1929 if (FromType1.getUnqualifiedType() != FromType2.getUnqualifiedType() && 1930 ToType1.getUnqualifiedType() == ToType2.getUnqualifiedType()) { 1931 if (IsDerivedFrom(FromType2, FromType1)) 1932 return ImplicitConversionSequence::Better; 1933 else if (IsDerivedFrom(FromType1, FromType2)) 1934 return ImplicitConversionSequence::Worse; 1935 } 1936 } 1937 1938 1939 // FIXME: conversion of A::* to B::* is better than conversion of 1940 // A::* to C::*, 1941 1942 // FIXME: conversion of B::* to C::* is better than conversion of 1943 // A::* to C::*, and 1944 1945 if (SCS1.CopyConstructor && SCS2.CopyConstructor && 1946 SCS1.Second == ICK_Derived_To_Base) { 1947 // -- conversion of C to B is better than conversion of C to A, 1948 if (FromType1.getUnqualifiedType() == FromType2.getUnqualifiedType() && 1949 ToType1.getUnqualifiedType() != ToType2.getUnqualifiedType()) { 1950 if (IsDerivedFrom(ToType1, ToType2)) 1951 return ImplicitConversionSequence::Better; 1952 else if (IsDerivedFrom(ToType2, ToType1)) 1953 return ImplicitConversionSequence::Worse; 1954 } 1955 1956 // -- conversion of B to A is better than conversion of C to A. 1957 if (FromType1.getUnqualifiedType() != FromType2.getUnqualifiedType() && 1958 ToType1.getUnqualifiedType() == ToType2.getUnqualifiedType()) { 1959 if (IsDerivedFrom(FromType2, FromType1)) 1960 return ImplicitConversionSequence::Better; 1961 else if (IsDerivedFrom(FromType1, FromType2)) 1962 return ImplicitConversionSequence::Worse; 1963 } 1964 } 1965 1966 return ImplicitConversionSequence::Indistinguishable; 1967} 1968 1969/// TryCopyInitialization - Try to copy-initialize a value of type 1970/// ToType from the expression From. Return the implicit conversion 1971/// sequence required to pass this argument, which may be a bad 1972/// conversion sequence (meaning that the argument cannot be passed to 1973/// a parameter of this type). If @p SuppressUserConversions, then we 1974/// do not permit any user-defined conversion sequences. If @p ForceRValue, 1975/// then we treat @p From as an rvalue, even if it is an lvalue. 1976ImplicitConversionSequence 1977Sema::TryCopyInitialization(Expr *From, QualType ToType, 1978 bool SuppressUserConversions, bool ForceRValue, 1979 bool InOverloadResolution) { 1980 if (ToType->isReferenceType()) { 1981 ImplicitConversionSequence ICS; 1982 CheckReferenceInit(From, ToType, 1983 /*FIXME:*/From->getLocStart(), 1984 SuppressUserConversions, 1985 /*AllowExplicit=*/false, 1986 ForceRValue, 1987 &ICS); 1988 return ICS; 1989 } else { 1990 return TryImplicitConversion(From, ToType, 1991 SuppressUserConversions, 1992 /*AllowExplicit=*/false, 1993 ForceRValue, 1994 InOverloadResolution); 1995 } 1996} 1997 1998/// PerformCopyInitialization - Copy-initialize an object of type @p ToType with 1999/// the expression @p From. Returns true (and emits a diagnostic) if there was 2000/// an error, returns false if the initialization succeeded. Elidable should 2001/// be true when the copy may be elided (C++ 12.8p15). Overload resolution works 2002/// differently in C++0x for this case. 2003bool Sema::PerformCopyInitialization(Expr *&From, QualType ToType, 2004 const char* Flavor, bool Elidable) { 2005 if (!getLangOptions().CPlusPlus) { 2006 // In C, argument passing is the same as performing an assignment. 2007 QualType FromType = From->getType(); 2008 2009 AssignConvertType ConvTy = 2010 CheckSingleAssignmentConstraints(ToType, From); 2011 if (ConvTy != Compatible && 2012 CheckTransparentUnionArgumentConstraints(ToType, From) == Compatible) 2013 ConvTy = Compatible; 2014 2015 return DiagnoseAssignmentResult(ConvTy, From->getLocStart(), ToType, 2016 FromType, From, Flavor); 2017 } 2018 2019 if (ToType->isReferenceType()) 2020 return CheckReferenceInit(From, ToType, 2021 /*FIXME:*/From->getLocStart(), 2022 /*SuppressUserConversions=*/false, 2023 /*AllowExplicit=*/false, 2024 /*ForceRValue=*/false); 2025 2026 if (!PerformImplicitConversion(From, ToType, Flavor, 2027 /*AllowExplicit=*/false, Elidable)) 2028 return false; 2029 if (!DiagnoseAmbiguousUserDefinedConversion(From, ToType)) 2030 return Diag(From->getSourceRange().getBegin(), 2031 diag::err_typecheck_convert_incompatible) 2032 << ToType << From->getType() << Flavor << From->getSourceRange(); 2033 return true; 2034} 2035 2036/// TryObjectArgumentInitialization - Try to initialize the object 2037/// parameter of the given member function (@c Method) from the 2038/// expression @p From. 2039ImplicitConversionSequence 2040Sema::TryObjectArgumentInitialization(Expr *From, CXXMethodDecl *Method) { 2041 QualType ClassType = Context.getTypeDeclType(Method->getParent()); 2042 QualType ImplicitParamType 2043 = Context.getCVRQualifiedType(ClassType, Method->getTypeQualifiers()); 2044 2045 // Set up the conversion sequence as a "bad" conversion, to allow us 2046 // to exit early. 2047 ImplicitConversionSequence ICS; 2048 ICS.Standard.setAsIdentityConversion(); 2049 ICS.ConversionKind = ImplicitConversionSequence::BadConversion; 2050 2051 // We need to have an object of class type. 2052 QualType FromType = From->getType(); 2053 if (const PointerType *PT = FromType->getAs<PointerType>()) 2054 FromType = PT->getPointeeType(); 2055 2056 assert(FromType->isRecordType()); 2057 2058 // The implicit object parmeter is has the type "reference to cv X", 2059 // where X is the class of which the function is a member 2060 // (C++ [over.match.funcs]p4). However, when finding an implicit 2061 // conversion sequence for the argument, we are not allowed to 2062 // create temporaries or perform user-defined conversions 2063 // (C++ [over.match.funcs]p5). We perform a simplified version of 2064 // reference binding here, that allows class rvalues to bind to 2065 // non-constant references. 2066 2067 // First check the qualifiers. We don't care about lvalue-vs-rvalue 2068 // with the implicit object parameter (C++ [over.match.funcs]p5). 2069 QualType FromTypeCanon = Context.getCanonicalType(FromType); 2070 if (ImplicitParamType.getCVRQualifiers() != FromType.getCVRQualifiers() && 2071 !ImplicitParamType.isAtLeastAsQualifiedAs(FromType)) 2072 return ICS; 2073 2074 // Check that we have either the same type or a derived type. It 2075 // affects the conversion rank. 2076 QualType ClassTypeCanon = Context.getCanonicalType(ClassType); 2077 if (ClassTypeCanon == FromTypeCanon.getUnqualifiedType()) 2078 ICS.Standard.Second = ICK_Identity; 2079 else if (IsDerivedFrom(FromType, ClassType)) 2080 ICS.Standard.Second = ICK_Derived_To_Base; 2081 else 2082 return ICS; 2083 2084 // Success. Mark this as a reference binding. 2085 ICS.ConversionKind = ImplicitConversionSequence::StandardConversion; 2086 ICS.Standard.FromTypePtr = FromType.getAsOpaquePtr(); 2087 ICS.Standard.ToTypePtr = ImplicitParamType.getAsOpaquePtr(); 2088 ICS.Standard.ReferenceBinding = true; 2089 ICS.Standard.DirectBinding = true; 2090 ICS.Standard.RRefBinding = false; 2091 return ICS; 2092} 2093 2094/// PerformObjectArgumentInitialization - Perform initialization of 2095/// the implicit object parameter for the given Method with the given 2096/// expression. 2097bool 2098Sema::PerformObjectArgumentInitialization(Expr *&From, CXXMethodDecl *Method) { 2099 QualType FromRecordType, DestType; 2100 QualType ImplicitParamRecordType = 2101 Method->getThisType(Context)->getAs<PointerType>()->getPointeeType(); 2102 2103 if (const PointerType *PT = From->getType()->getAs<PointerType>()) { 2104 FromRecordType = PT->getPointeeType(); 2105 DestType = Method->getThisType(Context); 2106 } else { 2107 FromRecordType = From->getType(); 2108 DestType = ImplicitParamRecordType; 2109 } 2110 2111 ImplicitConversionSequence ICS 2112 = TryObjectArgumentInitialization(From, Method); 2113 if (ICS.ConversionKind == ImplicitConversionSequence::BadConversion) 2114 return Diag(From->getSourceRange().getBegin(), 2115 diag::err_implicit_object_parameter_init) 2116 << ImplicitParamRecordType << FromRecordType << From->getSourceRange(); 2117 2118 if (ICS.Standard.Second == ICK_Derived_To_Base && 2119 CheckDerivedToBaseConversion(FromRecordType, 2120 ImplicitParamRecordType, 2121 From->getSourceRange().getBegin(), 2122 From->getSourceRange())) 2123 return true; 2124 2125 ImpCastExprToType(From, DestType, CastExpr::CK_DerivedToBase, 2126 /*isLvalue=*/true); 2127 return false; 2128} 2129 2130/// TryContextuallyConvertToBool - Attempt to contextually convert the 2131/// expression From to bool (C++0x [conv]p3). 2132ImplicitConversionSequence Sema::TryContextuallyConvertToBool(Expr *From) { 2133 return TryImplicitConversion(From, Context.BoolTy, 2134 // FIXME: Are these flags correct? 2135 /*SuppressUserConversions=*/false, 2136 /*AllowExplicit=*/true, 2137 /*ForceRValue=*/false, 2138 /*InOverloadResolution=*/false); 2139} 2140 2141/// PerformContextuallyConvertToBool - Perform a contextual conversion 2142/// of the expression From to bool (C++0x [conv]p3). 2143bool Sema::PerformContextuallyConvertToBool(Expr *&From) { 2144 ImplicitConversionSequence ICS = TryContextuallyConvertToBool(From); 2145 if (!PerformImplicitConversion(From, Context.BoolTy, ICS, "converting")) 2146 return false; 2147 2148 if (!DiagnoseAmbiguousUserDefinedConversion(From, Context.BoolTy)) 2149 return Diag(From->getSourceRange().getBegin(), 2150 diag::err_typecheck_bool_condition) 2151 << From->getType() << From->getSourceRange(); 2152 return true; 2153} 2154 2155/// AddOverloadCandidate - Adds the given function to the set of 2156/// candidate functions, using the given function call arguments. If 2157/// @p SuppressUserConversions, then don't allow user-defined 2158/// conversions via constructors or conversion operators. 2159/// If @p ForceRValue, treat all arguments as rvalues. This is a slightly 2160/// hacky way to implement the overloading rules for elidable copy 2161/// initialization in C++0x (C++0x 12.8p15). 2162/// 2163/// \para PartialOverloading true if we are performing "partial" overloading 2164/// based on an incomplete set of function arguments. This feature is used by 2165/// code completion. 2166void 2167Sema::AddOverloadCandidate(FunctionDecl *Function, 2168 Expr **Args, unsigned NumArgs, 2169 OverloadCandidateSet& CandidateSet, 2170 bool SuppressUserConversions, 2171 bool ForceRValue, 2172 bool PartialOverloading) { 2173 const FunctionProtoType* Proto 2174 = dyn_cast<FunctionProtoType>(Function->getType()->getAs<FunctionType>()); 2175 assert(Proto && "Functions without a prototype cannot be overloaded"); 2176 assert(!isa<CXXConversionDecl>(Function) && 2177 "Use AddConversionCandidate for conversion functions"); 2178 assert(!Function->getDescribedFunctionTemplate() && 2179 "Use AddTemplateOverloadCandidate for function templates"); 2180 2181 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Function)) { 2182 if (!isa<CXXConstructorDecl>(Method)) { 2183 // If we get here, it's because we're calling a member function 2184 // that is named without a member access expression (e.g., 2185 // "this->f") that was either written explicitly or created 2186 // implicitly. This can happen with a qualified call to a member 2187 // function, e.g., X::f(). We use a NULL object as the implied 2188 // object argument (C++ [over.call.func]p3). 2189 AddMethodCandidate(Method, 0, Args, NumArgs, CandidateSet, 2190 SuppressUserConversions, ForceRValue); 2191 return; 2192 } 2193 // We treat a constructor like a non-member function, since its object 2194 // argument doesn't participate in overload resolution. 2195 } 2196 2197 if (!CandidateSet.isNewCandidate(Function)) 2198 return; 2199 2200 // Add this candidate 2201 CandidateSet.push_back(OverloadCandidate()); 2202 OverloadCandidate& Candidate = CandidateSet.back(); 2203 Candidate.Function = Function; 2204 Candidate.Viable = true; 2205 Candidate.IsSurrogate = false; 2206 Candidate.IgnoreObjectArgument = false; 2207 2208 unsigned NumArgsInProto = Proto->getNumArgs(); 2209 2210 // (C++ 13.3.2p2): A candidate function having fewer than m 2211 // parameters is viable only if it has an ellipsis in its parameter 2212 // list (8.3.5). 2213 if ((NumArgs + (PartialOverloading && NumArgs)) > NumArgsInProto && 2214 !Proto->isVariadic()) { 2215 Candidate.Viable = false; 2216 return; 2217 } 2218 2219 // (C++ 13.3.2p2): A candidate function having more than m parameters 2220 // is viable only if the (m+1)st parameter has a default argument 2221 // (8.3.6). For the purposes of overload resolution, the 2222 // parameter list is truncated on the right, so that there are 2223 // exactly m parameters. 2224 unsigned MinRequiredArgs = Function->getMinRequiredArguments(); 2225 if (NumArgs < MinRequiredArgs && !PartialOverloading) { 2226 // Not enough arguments. 2227 Candidate.Viable = false; 2228 return; 2229 } 2230 2231 // Determine the implicit conversion sequences for each of the 2232 // arguments. 2233 Candidate.Conversions.resize(NumArgs); 2234 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2235 if (ArgIdx < NumArgsInProto) { 2236 // (C++ 13.3.2p3): for F to be a viable function, there shall 2237 // exist for each argument an implicit conversion sequence 2238 // (13.3.3.1) that converts that argument to the corresponding 2239 // parameter of F. 2240 QualType ParamType = Proto->getArgType(ArgIdx); 2241 Candidate.Conversions[ArgIdx] 2242 = TryCopyInitialization(Args[ArgIdx], ParamType, 2243 SuppressUserConversions, ForceRValue, 2244 /*InOverloadResolution=*/true); 2245 if (Candidate.Conversions[ArgIdx].ConversionKind 2246 == ImplicitConversionSequence::BadConversion) { 2247 // 13.3.3.1-p10 If several different sequences of conversions exist that 2248 // each convert the argument to the parameter type, the implicit conversion 2249 // sequence associated with the parameter is defined to be the unique conversion 2250 // sequence designated the ambiguous conversion sequence. For the purpose of 2251 // ranking implicit conversion sequences as described in 13.3.3.2, the ambiguous 2252 // conversion sequence is treated as a user-defined sequence that is 2253 // indistinguishable from any other user-defined conversion sequence 2254 if (!Candidate.Conversions[ArgIdx].ConversionFunctionSet.empty()) { 2255 Candidate.Conversions[ArgIdx].ConversionKind = 2256 ImplicitConversionSequence::UserDefinedConversion; 2257 // Set the conversion function to one of them. As due to ambiguity, 2258 // they carry the same weight and is needed for overload resolution 2259 // later. 2260 Candidate.Conversions[ArgIdx].UserDefined.ConversionFunction = 2261 Candidate.Conversions[ArgIdx].ConversionFunctionSet[0]; 2262 } 2263 else { 2264 Candidate.Viable = false; 2265 break; 2266 } 2267 } 2268 } else { 2269 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2270 // argument for which there is no corresponding parameter is 2271 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2272 Candidate.Conversions[ArgIdx].ConversionKind 2273 = ImplicitConversionSequence::EllipsisConversion; 2274 } 2275 } 2276} 2277 2278/// \brief Add all of the function declarations in the given function set to 2279/// the overload canddiate set. 2280void Sema::AddFunctionCandidates(const FunctionSet &Functions, 2281 Expr **Args, unsigned NumArgs, 2282 OverloadCandidateSet& CandidateSet, 2283 bool SuppressUserConversions) { 2284 for (FunctionSet::const_iterator F = Functions.begin(), 2285 FEnd = Functions.end(); 2286 F != FEnd; ++F) { 2287 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*F)) { 2288 if (isa<CXXMethodDecl>(FD) && !cast<CXXMethodDecl>(FD)->isStatic()) 2289 AddMethodCandidate(cast<CXXMethodDecl>(FD), 2290 Args[0], Args + 1, NumArgs - 1, 2291 CandidateSet, SuppressUserConversions); 2292 else 2293 AddOverloadCandidate(FD, Args, NumArgs, CandidateSet, 2294 SuppressUserConversions); 2295 } else { 2296 FunctionTemplateDecl *FunTmpl = cast<FunctionTemplateDecl>(*F); 2297 if (isa<CXXMethodDecl>(FunTmpl->getTemplatedDecl()) && 2298 !cast<CXXMethodDecl>(FunTmpl->getTemplatedDecl())->isStatic()) 2299 AddMethodTemplateCandidate(FunTmpl, 2300 /*FIXME: explicit args */false, 0, 0, 2301 Args[0], Args + 1, NumArgs - 1, 2302 CandidateSet, 2303 SuppressUserConversions); 2304 else 2305 AddTemplateOverloadCandidate(FunTmpl, 2306 /*FIXME: explicit args */false, 0, 0, 2307 Args, NumArgs, CandidateSet, 2308 SuppressUserConversions); 2309 } 2310 } 2311} 2312 2313/// AddMethodCandidate - Adds the given C++ member function to the set 2314/// of candidate functions, using the given function call arguments 2315/// and the object argument (@c Object). For example, in a call 2316/// @c o.f(a1,a2), @c Object will contain @c o and @c Args will contain 2317/// both @c a1 and @c a2. If @p SuppressUserConversions, then don't 2318/// allow user-defined conversions via constructors or conversion 2319/// operators. If @p ForceRValue, treat all arguments as rvalues. This is 2320/// a slightly hacky way to implement the overloading rules for elidable copy 2321/// initialization in C++0x (C++0x 12.8p15). 2322void 2323Sema::AddMethodCandidate(CXXMethodDecl *Method, Expr *Object, 2324 Expr **Args, unsigned NumArgs, 2325 OverloadCandidateSet& CandidateSet, 2326 bool SuppressUserConversions, bool ForceRValue) { 2327 const FunctionProtoType* Proto 2328 = dyn_cast<FunctionProtoType>(Method->getType()->getAs<FunctionType>()); 2329 assert(Proto && "Methods without a prototype cannot be overloaded"); 2330 assert(!isa<CXXConversionDecl>(Method) && 2331 "Use AddConversionCandidate for conversion functions"); 2332 assert(!isa<CXXConstructorDecl>(Method) && 2333 "Use AddOverloadCandidate for constructors"); 2334 2335 if (!CandidateSet.isNewCandidate(Method)) 2336 return; 2337 2338 // Add this candidate 2339 CandidateSet.push_back(OverloadCandidate()); 2340 OverloadCandidate& Candidate = CandidateSet.back(); 2341 Candidate.Function = Method; 2342 Candidate.IsSurrogate = false; 2343 Candidate.IgnoreObjectArgument = false; 2344 2345 unsigned NumArgsInProto = Proto->getNumArgs(); 2346 2347 // (C++ 13.3.2p2): A candidate function having fewer than m 2348 // parameters is viable only if it has an ellipsis in its parameter 2349 // list (8.3.5). 2350 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 2351 Candidate.Viable = false; 2352 return; 2353 } 2354 2355 // (C++ 13.3.2p2): A candidate function having more than m parameters 2356 // is viable only if the (m+1)st parameter has a default argument 2357 // (8.3.6). For the purposes of overload resolution, the 2358 // parameter list is truncated on the right, so that there are 2359 // exactly m parameters. 2360 unsigned MinRequiredArgs = Method->getMinRequiredArguments(); 2361 if (NumArgs < MinRequiredArgs) { 2362 // Not enough arguments. 2363 Candidate.Viable = false; 2364 return; 2365 } 2366 2367 Candidate.Viable = true; 2368 Candidate.Conversions.resize(NumArgs + 1); 2369 2370 if (Method->isStatic() || !Object) 2371 // The implicit object argument is ignored. 2372 Candidate.IgnoreObjectArgument = true; 2373 else { 2374 // Determine the implicit conversion sequence for the object 2375 // parameter. 2376 Candidate.Conversions[0] = TryObjectArgumentInitialization(Object, Method); 2377 if (Candidate.Conversions[0].ConversionKind 2378 == ImplicitConversionSequence::BadConversion) { 2379 Candidate.Viable = false; 2380 return; 2381 } 2382 } 2383 2384 // Determine the implicit conversion sequences for each of the 2385 // arguments. 2386 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2387 if (ArgIdx < NumArgsInProto) { 2388 // (C++ 13.3.2p3): for F to be a viable function, there shall 2389 // exist for each argument an implicit conversion sequence 2390 // (13.3.3.1) that converts that argument to the corresponding 2391 // parameter of F. 2392 QualType ParamType = Proto->getArgType(ArgIdx); 2393 Candidate.Conversions[ArgIdx + 1] 2394 = TryCopyInitialization(Args[ArgIdx], ParamType, 2395 SuppressUserConversions, ForceRValue, 2396 /*InOverloadResolution=*/true); 2397 if (Candidate.Conversions[ArgIdx + 1].ConversionKind 2398 == ImplicitConversionSequence::BadConversion) { 2399 Candidate.Viable = false; 2400 break; 2401 } 2402 } else { 2403 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2404 // argument for which there is no corresponding parameter is 2405 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2406 Candidate.Conversions[ArgIdx + 1].ConversionKind 2407 = ImplicitConversionSequence::EllipsisConversion; 2408 } 2409 } 2410} 2411 2412/// \brief Add a C++ member function template as a candidate to the candidate 2413/// set, using template argument deduction to produce an appropriate member 2414/// function template specialization. 2415void 2416Sema::AddMethodTemplateCandidate(FunctionTemplateDecl *MethodTmpl, 2417 bool HasExplicitTemplateArgs, 2418 const TemplateArgument *ExplicitTemplateArgs, 2419 unsigned NumExplicitTemplateArgs, 2420 Expr *Object, Expr **Args, unsigned NumArgs, 2421 OverloadCandidateSet& CandidateSet, 2422 bool SuppressUserConversions, 2423 bool ForceRValue) { 2424 if (!CandidateSet.isNewCandidate(MethodTmpl)) 2425 return; 2426 2427 // C++ [over.match.funcs]p7: 2428 // In each case where a candidate is a function template, candidate 2429 // function template specializations are generated using template argument 2430 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 2431 // candidate functions in the usual way.113) A given name can refer to one 2432 // or more function templates and also to a set of overloaded non-template 2433 // functions. In such a case, the candidate functions generated from each 2434 // function template are combined with the set of non-template candidate 2435 // functions. 2436 TemplateDeductionInfo Info(Context); 2437 FunctionDecl *Specialization = 0; 2438 if (TemplateDeductionResult Result 2439 = DeduceTemplateArguments(MethodTmpl, HasExplicitTemplateArgs, 2440 ExplicitTemplateArgs, NumExplicitTemplateArgs, 2441 Args, NumArgs, Specialization, Info)) { 2442 // FIXME: Record what happened with template argument deduction, so 2443 // that we can give the user a beautiful diagnostic. 2444 (void)Result; 2445 return; 2446 } 2447 2448 // Add the function template specialization produced by template argument 2449 // deduction as a candidate. 2450 assert(Specialization && "Missing member function template specialization?"); 2451 assert(isa<CXXMethodDecl>(Specialization) && 2452 "Specialization is not a member function?"); 2453 AddMethodCandidate(cast<CXXMethodDecl>(Specialization), Object, Args, NumArgs, 2454 CandidateSet, SuppressUserConversions, ForceRValue); 2455} 2456 2457/// \brief Add a C++ function template specialization as a candidate 2458/// in the candidate set, using template argument deduction to produce 2459/// an appropriate function template specialization. 2460void 2461Sema::AddTemplateOverloadCandidate(FunctionTemplateDecl *FunctionTemplate, 2462 bool HasExplicitTemplateArgs, 2463 const TemplateArgument *ExplicitTemplateArgs, 2464 unsigned NumExplicitTemplateArgs, 2465 Expr **Args, unsigned NumArgs, 2466 OverloadCandidateSet& CandidateSet, 2467 bool SuppressUserConversions, 2468 bool ForceRValue) { 2469 if (!CandidateSet.isNewCandidate(FunctionTemplate)) 2470 return; 2471 2472 // C++ [over.match.funcs]p7: 2473 // In each case where a candidate is a function template, candidate 2474 // function template specializations are generated using template argument 2475 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 2476 // candidate functions in the usual way.113) A given name can refer to one 2477 // or more function templates and also to a set of overloaded non-template 2478 // functions. In such a case, the candidate functions generated from each 2479 // function template are combined with the set of non-template candidate 2480 // functions. 2481 TemplateDeductionInfo Info(Context); 2482 FunctionDecl *Specialization = 0; 2483 if (TemplateDeductionResult Result 2484 = DeduceTemplateArguments(FunctionTemplate, HasExplicitTemplateArgs, 2485 ExplicitTemplateArgs, NumExplicitTemplateArgs, 2486 Args, NumArgs, Specialization, Info)) { 2487 // FIXME: Record what happened with template argument deduction, so 2488 // that we can give the user a beautiful diagnostic. 2489 (void)Result; 2490 return; 2491 } 2492 2493 // Add the function template specialization produced by template argument 2494 // deduction as a candidate. 2495 assert(Specialization && "Missing function template specialization?"); 2496 AddOverloadCandidate(Specialization, Args, NumArgs, CandidateSet, 2497 SuppressUserConversions, ForceRValue); 2498} 2499 2500/// AddConversionCandidate - Add a C++ conversion function as a 2501/// candidate in the candidate set (C++ [over.match.conv], 2502/// C++ [over.match.copy]). From is the expression we're converting from, 2503/// and ToType is the type that we're eventually trying to convert to 2504/// (which may or may not be the same type as the type that the 2505/// conversion function produces). 2506void 2507Sema::AddConversionCandidate(CXXConversionDecl *Conversion, 2508 Expr *From, QualType ToType, 2509 OverloadCandidateSet& CandidateSet) { 2510 assert(!Conversion->getDescribedFunctionTemplate() && 2511 "Conversion function templates use AddTemplateConversionCandidate"); 2512 2513 if (!CandidateSet.isNewCandidate(Conversion)) 2514 return; 2515 2516 // Add this candidate 2517 CandidateSet.push_back(OverloadCandidate()); 2518 OverloadCandidate& Candidate = CandidateSet.back(); 2519 Candidate.Function = Conversion; 2520 Candidate.IsSurrogate = false; 2521 Candidate.IgnoreObjectArgument = false; 2522 Candidate.FinalConversion.setAsIdentityConversion(); 2523 Candidate.FinalConversion.FromTypePtr 2524 = Conversion->getConversionType().getAsOpaquePtr(); 2525 Candidate.FinalConversion.ToTypePtr = ToType.getAsOpaquePtr(); 2526 2527 // Determine the implicit conversion sequence for the implicit 2528 // object parameter. 2529 Candidate.Viable = true; 2530 Candidate.Conversions.resize(1); 2531 Candidate.Conversions[0] = TryObjectArgumentInitialization(From, Conversion); 2532 // Conversion functions to a different type in the base class is visible in 2533 // the derived class. So, a derived to base conversion should not participate 2534 // in overload resolution. 2535 if (Candidate.Conversions[0].Standard.Second == ICK_Derived_To_Base) 2536 Candidate.Conversions[0].Standard.Second = ICK_Identity; 2537 if (Candidate.Conversions[0].ConversionKind 2538 == ImplicitConversionSequence::BadConversion) { 2539 Candidate.Viable = false; 2540 return; 2541 } 2542 2543 // We won't go through a user-define type conversion function to convert a 2544 // derived to base as such conversions are given Conversion Rank. They only 2545 // go through a copy constructor. 13.3.3.1.2-p4 [over.ics.user] 2546 QualType FromCanon 2547 = Context.getCanonicalType(From->getType().getUnqualifiedType()); 2548 QualType ToCanon = Context.getCanonicalType(ToType).getUnqualifiedType(); 2549 if (FromCanon == ToCanon || IsDerivedFrom(FromCanon, ToCanon)) { 2550 Candidate.Viable = false; 2551 return; 2552 } 2553 2554 2555 // To determine what the conversion from the result of calling the 2556 // conversion function to the type we're eventually trying to 2557 // convert to (ToType), we need to synthesize a call to the 2558 // conversion function and attempt copy initialization from it. This 2559 // makes sure that we get the right semantics with respect to 2560 // lvalues/rvalues and the type. Fortunately, we can allocate this 2561 // call on the stack and we don't need its arguments to be 2562 // well-formed. 2563 DeclRefExpr ConversionRef(Conversion, Conversion->getType(), 2564 SourceLocation()); 2565 ImplicitCastExpr ConversionFn(Context.getPointerType(Conversion->getType()), 2566 CastExpr::CK_Unknown, 2567 &ConversionRef, false); 2568 2569 // Note that it is safe to allocate CallExpr on the stack here because 2570 // there are 0 arguments (i.e., nothing is allocated using ASTContext's 2571 // allocator). 2572 CallExpr Call(Context, &ConversionFn, 0, 0, 2573 Conversion->getConversionType().getNonReferenceType(), 2574 SourceLocation()); 2575 ImplicitConversionSequence ICS = 2576 TryCopyInitialization(&Call, ToType, 2577 /*SuppressUserConversions=*/true, 2578 /*ForceRValue=*/false, 2579 /*InOverloadResolution=*/false); 2580 2581 switch (ICS.ConversionKind) { 2582 case ImplicitConversionSequence::StandardConversion: 2583 Candidate.FinalConversion = ICS.Standard; 2584 break; 2585 2586 case ImplicitConversionSequence::BadConversion: 2587 Candidate.Viable = false; 2588 break; 2589 2590 default: 2591 assert(false && 2592 "Can only end up with a standard conversion sequence or failure"); 2593 } 2594} 2595 2596/// \brief Adds a conversion function template specialization 2597/// candidate to the overload set, using template argument deduction 2598/// to deduce the template arguments of the conversion function 2599/// template from the type that we are converting to (C++ 2600/// [temp.deduct.conv]). 2601void 2602Sema::AddTemplateConversionCandidate(FunctionTemplateDecl *FunctionTemplate, 2603 Expr *From, QualType ToType, 2604 OverloadCandidateSet &CandidateSet) { 2605 assert(isa<CXXConversionDecl>(FunctionTemplate->getTemplatedDecl()) && 2606 "Only conversion function templates permitted here"); 2607 2608 if (!CandidateSet.isNewCandidate(FunctionTemplate)) 2609 return; 2610 2611 TemplateDeductionInfo Info(Context); 2612 CXXConversionDecl *Specialization = 0; 2613 if (TemplateDeductionResult Result 2614 = DeduceTemplateArguments(FunctionTemplate, ToType, 2615 Specialization, Info)) { 2616 // FIXME: Record what happened with template argument deduction, so 2617 // that we can give the user a beautiful diagnostic. 2618 (void)Result; 2619 return; 2620 } 2621 2622 // Add the conversion function template specialization produced by 2623 // template argument deduction as a candidate. 2624 assert(Specialization && "Missing function template specialization?"); 2625 AddConversionCandidate(Specialization, From, ToType, CandidateSet); 2626} 2627 2628/// AddSurrogateCandidate - Adds a "surrogate" candidate function that 2629/// converts the given @c Object to a function pointer via the 2630/// conversion function @c Conversion, and then attempts to call it 2631/// with the given arguments (C++ [over.call.object]p2-4). Proto is 2632/// the type of function that we'll eventually be calling. 2633void Sema::AddSurrogateCandidate(CXXConversionDecl *Conversion, 2634 const FunctionProtoType *Proto, 2635 Expr *Object, Expr **Args, unsigned NumArgs, 2636 OverloadCandidateSet& CandidateSet) { 2637 if (!CandidateSet.isNewCandidate(Conversion)) 2638 return; 2639 2640 CandidateSet.push_back(OverloadCandidate()); 2641 OverloadCandidate& Candidate = CandidateSet.back(); 2642 Candidate.Function = 0; 2643 Candidate.Surrogate = Conversion; 2644 Candidate.Viable = true; 2645 Candidate.IsSurrogate = true; 2646 Candidate.IgnoreObjectArgument = false; 2647 Candidate.Conversions.resize(NumArgs + 1); 2648 2649 // Determine the implicit conversion sequence for the implicit 2650 // object parameter. 2651 ImplicitConversionSequence ObjectInit 2652 = TryObjectArgumentInitialization(Object, Conversion); 2653 if (ObjectInit.ConversionKind == ImplicitConversionSequence::BadConversion) { 2654 Candidate.Viable = false; 2655 return; 2656 } 2657 2658 // The first conversion is actually a user-defined conversion whose 2659 // first conversion is ObjectInit's standard conversion (which is 2660 // effectively a reference binding). Record it as such. 2661 Candidate.Conversions[0].ConversionKind 2662 = ImplicitConversionSequence::UserDefinedConversion; 2663 Candidate.Conversions[0].UserDefined.Before = ObjectInit.Standard; 2664 Candidate.Conversions[0].UserDefined.ConversionFunction = Conversion; 2665 Candidate.Conversions[0].UserDefined.After 2666 = Candidate.Conversions[0].UserDefined.Before; 2667 Candidate.Conversions[0].UserDefined.After.setAsIdentityConversion(); 2668 2669 // Find the 2670 unsigned NumArgsInProto = Proto->getNumArgs(); 2671 2672 // (C++ 13.3.2p2): A candidate function having fewer than m 2673 // parameters is viable only if it has an ellipsis in its parameter 2674 // list (8.3.5). 2675 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 2676 Candidate.Viable = false; 2677 return; 2678 } 2679 2680 // Function types don't have any default arguments, so just check if 2681 // we have enough arguments. 2682 if (NumArgs < NumArgsInProto) { 2683 // Not enough arguments. 2684 Candidate.Viable = false; 2685 return; 2686 } 2687 2688 // Determine the implicit conversion sequences for each of the 2689 // arguments. 2690 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2691 if (ArgIdx < NumArgsInProto) { 2692 // (C++ 13.3.2p3): for F to be a viable function, there shall 2693 // exist for each argument an implicit conversion sequence 2694 // (13.3.3.1) that converts that argument to the corresponding 2695 // parameter of F. 2696 QualType ParamType = Proto->getArgType(ArgIdx); 2697 Candidate.Conversions[ArgIdx + 1] 2698 = TryCopyInitialization(Args[ArgIdx], ParamType, 2699 /*SuppressUserConversions=*/false, 2700 /*ForceRValue=*/false, 2701 /*InOverloadResolution=*/false); 2702 if (Candidate.Conversions[ArgIdx + 1].ConversionKind 2703 == ImplicitConversionSequence::BadConversion) { 2704 Candidate.Viable = false; 2705 break; 2706 } 2707 } else { 2708 // (C++ 13.3.2p2): For the purposes of overload resolution, any 2709 // argument for which there is no corresponding parameter is 2710 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 2711 Candidate.Conversions[ArgIdx + 1].ConversionKind 2712 = ImplicitConversionSequence::EllipsisConversion; 2713 } 2714 } 2715} 2716 2717// FIXME: This will eventually be removed, once we've migrated all of the 2718// operator overloading logic over to the scheme used by binary operators, which 2719// works for template instantiation. 2720void Sema::AddOperatorCandidates(OverloadedOperatorKind Op, Scope *S, 2721 SourceLocation OpLoc, 2722 Expr **Args, unsigned NumArgs, 2723 OverloadCandidateSet& CandidateSet, 2724 SourceRange OpRange) { 2725 FunctionSet Functions; 2726 2727 QualType T1 = Args[0]->getType(); 2728 QualType T2; 2729 if (NumArgs > 1) 2730 T2 = Args[1]->getType(); 2731 2732 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 2733 if (S) 2734 LookupOverloadedOperatorName(Op, S, T1, T2, Functions); 2735 ArgumentDependentLookup(OpName, Args, NumArgs, Functions); 2736 AddFunctionCandidates(Functions, Args, NumArgs, CandidateSet); 2737 AddMemberOperatorCandidates(Op, OpLoc, Args, NumArgs, CandidateSet, OpRange); 2738 AddBuiltinOperatorCandidates(Op, Args, NumArgs, CandidateSet); 2739} 2740 2741/// \brief Add overload candidates for overloaded operators that are 2742/// member functions. 2743/// 2744/// Add the overloaded operator candidates that are member functions 2745/// for the operator Op that was used in an operator expression such 2746/// as "x Op y". , Args/NumArgs provides the operator arguments, and 2747/// CandidateSet will store the added overload candidates. (C++ 2748/// [over.match.oper]). 2749void Sema::AddMemberOperatorCandidates(OverloadedOperatorKind Op, 2750 SourceLocation OpLoc, 2751 Expr **Args, unsigned NumArgs, 2752 OverloadCandidateSet& CandidateSet, 2753 SourceRange OpRange) { 2754 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 2755 2756 // C++ [over.match.oper]p3: 2757 // For a unary operator @ with an operand of a type whose 2758 // cv-unqualified version is T1, and for a binary operator @ with 2759 // a left operand of a type whose cv-unqualified version is T1 and 2760 // a right operand of a type whose cv-unqualified version is T2, 2761 // three sets of candidate functions, designated member 2762 // candidates, non-member candidates and built-in candidates, are 2763 // constructed as follows: 2764 QualType T1 = Args[0]->getType(); 2765 QualType T2; 2766 if (NumArgs > 1) 2767 T2 = Args[1]->getType(); 2768 2769 // -- If T1 is a class type, the set of member candidates is the 2770 // result of the qualified lookup of T1::operator@ 2771 // (13.3.1.1.1); otherwise, the set of member candidates is 2772 // empty. 2773 if (const RecordType *T1Rec = T1->getAs<RecordType>()) { 2774 // Complete the type if it can be completed. Otherwise, we're done. 2775 if (RequireCompleteType(OpLoc, T1, PDiag())) 2776 return; 2777 2778 LookupResult Operators; 2779 LookupQualifiedName(Operators, T1Rec->getDecl(), OpName, 2780 LookupOrdinaryName, false); 2781 for (LookupResult::iterator Oper = Operators.begin(), 2782 OperEnd = Operators.end(); 2783 Oper != OperEnd; 2784 ++Oper) { 2785 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(*Oper)) { 2786 AddMethodCandidate(Method, Args[0], Args+1, NumArgs - 1, CandidateSet, 2787 /*SuppressUserConversions=*/false); 2788 continue; 2789 } 2790 2791 assert(isa<FunctionTemplateDecl>(*Oper) && 2792 isa<CXXMethodDecl>(cast<FunctionTemplateDecl>(*Oper) 2793 ->getTemplatedDecl()) && 2794 "Expected a member function template"); 2795 AddMethodTemplateCandidate(cast<FunctionTemplateDecl>(*Oper), false, 0, 0, 2796 Args[0], Args+1, NumArgs - 1, CandidateSet, 2797 /*SuppressUserConversions=*/false); 2798 } 2799 } 2800} 2801 2802/// AddBuiltinCandidate - Add a candidate for a built-in 2803/// operator. ResultTy and ParamTys are the result and parameter types 2804/// of the built-in candidate, respectively. Args and NumArgs are the 2805/// arguments being passed to the candidate. IsAssignmentOperator 2806/// should be true when this built-in candidate is an assignment 2807/// operator. NumContextualBoolArguments is the number of arguments 2808/// (at the beginning of the argument list) that will be contextually 2809/// converted to bool. 2810void Sema::AddBuiltinCandidate(QualType ResultTy, QualType *ParamTys, 2811 Expr **Args, unsigned NumArgs, 2812 OverloadCandidateSet& CandidateSet, 2813 bool IsAssignmentOperator, 2814 unsigned NumContextualBoolArguments) { 2815 // Add this candidate 2816 CandidateSet.push_back(OverloadCandidate()); 2817 OverloadCandidate& Candidate = CandidateSet.back(); 2818 Candidate.Function = 0; 2819 Candidate.IsSurrogate = false; 2820 Candidate.IgnoreObjectArgument = false; 2821 Candidate.BuiltinTypes.ResultTy = ResultTy; 2822 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 2823 Candidate.BuiltinTypes.ParamTypes[ArgIdx] = ParamTys[ArgIdx]; 2824 2825 // Determine the implicit conversion sequences for each of the 2826 // arguments. 2827 Candidate.Viable = true; 2828 Candidate.Conversions.resize(NumArgs); 2829 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 2830 // C++ [over.match.oper]p4: 2831 // For the built-in assignment operators, conversions of the 2832 // left operand are restricted as follows: 2833 // -- no temporaries are introduced to hold the left operand, and 2834 // -- no user-defined conversions are applied to the left 2835 // operand to achieve a type match with the left-most 2836 // parameter of a built-in candidate. 2837 // 2838 // We block these conversions by turning off user-defined 2839 // conversions, since that is the only way that initialization of 2840 // a reference to a non-class type can occur from something that 2841 // is not of the same type. 2842 if (ArgIdx < NumContextualBoolArguments) { 2843 assert(ParamTys[ArgIdx] == Context.BoolTy && 2844 "Contextual conversion to bool requires bool type"); 2845 Candidate.Conversions[ArgIdx] = TryContextuallyConvertToBool(Args[ArgIdx]); 2846 } else { 2847 Candidate.Conversions[ArgIdx] 2848 = TryCopyInitialization(Args[ArgIdx], ParamTys[ArgIdx], 2849 ArgIdx == 0 && IsAssignmentOperator, 2850 /*ForceRValue=*/false, 2851 /*InOverloadResolution=*/false); 2852 } 2853 if (Candidate.Conversions[ArgIdx].ConversionKind 2854 == ImplicitConversionSequence::BadConversion) { 2855 Candidate.Viable = false; 2856 break; 2857 } 2858 } 2859} 2860 2861/// BuiltinCandidateTypeSet - A set of types that will be used for the 2862/// candidate operator functions for built-in operators (C++ 2863/// [over.built]). The types are separated into pointer types and 2864/// enumeration types. 2865class BuiltinCandidateTypeSet { 2866 /// TypeSet - A set of types. 2867 typedef llvm::SmallPtrSet<QualType, 8> TypeSet; 2868 2869 /// PointerTypes - The set of pointer types that will be used in the 2870 /// built-in candidates. 2871 TypeSet PointerTypes; 2872 2873 /// MemberPointerTypes - The set of member pointer types that will be 2874 /// used in the built-in candidates. 2875 TypeSet MemberPointerTypes; 2876 2877 /// EnumerationTypes - The set of enumeration types that will be 2878 /// used in the built-in candidates. 2879 TypeSet EnumerationTypes; 2880 2881 /// Sema - The semantic analysis instance where we are building the 2882 /// candidate type set. 2883 Sema &SemaRef; 2884 2885 /// Context - The AST context in which we will build the type sets. 2886 ASTContext &Context; 2887 2888 bool AddPointerWithMoreQualifiedTypeVariants(QualType Ty, 2889 const Qualifiers &VisibleQuals); 2890 bool AddMemberPointerWithMoreQualifiedTypeVariants(QualType Ty); 2891 2892public: 2893 /// iterator - Iterates through the types that are part of the set. 2894 typedef TypeSet::iterator iterator; 2895 2896 BuiltinCandidateTypeSet(Sema &SemaRef) 2897 : SemaRef(SemaRef), Context(SemaRef.Context) { } 2898 2899 void AddTypesConvertedFrom(QualType Ty, bool AllowUserConversions, 2900 bool AllowExplicitConversions, 2901 const Qualifiers &VisibleTypeConversionsQuals); 2902 2903 /// pointer_begin - First pointer type found; 2904 iterator pointer_begin() { return PointerTypes.begin(); } 2905 2906 /// pointer_end - Past the last pointer type found; 2907 iterator pointer_end() { return PointerTypes.end(); } 2908 2909 /// member_pointer_begin - First member pointer type found; 2910 iterator member_pointer_begin() { return MemberPointerTypes.begin(); } 2911 2912 /// member_pointer_end - Past the last member pointer type found; 2913 iterator member_pointer_end() { return MemberPointerTypes.end(); } 2914 2915 /// enumeration_begin - First enumeration type found; 2916 iterator enumeration_begin() { return EnumerationTypes.begin(); } 2917 2918 /// enumeration_end - Past the last enumeration type found; 2919 iterator enumeration_end() { return EnumerationTypes.end(); } 2920}; 2921 2922/// AddPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty to 2923/// the set of pointer types along with any more-qualified variants of 2924/// that type. For example, if @p Ty is "int const *", this routine 2925/// will add "int const *", "int const volatile *", "int const 2926/// restrict *", and "int const volatile restrict *" to the set of 2927/// pointer types. Returns true if the add of @p Ty itself succeeded, 2928/// false otherwise. 2929/// 2930/// FIXME: what to do about extended qualifiers? 2931bool 2932BuiltinCandidateTypeSet::AddPointerWithMoreQualifiedTypeVariants(QualType Ty 2933 ,const Qualifiers &VisibleQuals) { 2934 2935 // Insert this type. 2936 if (!PointerTypes.insert(Ty)) 2937 return false; 2938 2939 const PointerType *PointerTy = Ty->getAs<PointerType>(); 2940 assert(PointerTy && "type was not a pointer type!"); 2941 2942 QualType PointeeTy = PointerTy->getPointeeType(); 2943 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 2944 bool hasVolatile = VisibleQuals.hasVolatile(); 2945 bool hasRestrict = VisibleQuals.hasRestrict(); 2946 2947 // Iterate through all strict supersets of BaseCVR. 2948 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 2949 if ((CVR | BaseCVR) != CVR) continue; 2950 // Skip over Volatile/Restrict if no Volatile/Restrict found anywhere 2951 // in the types. 2952 if ((CVR & Qualifiers::Volatile) && !hasVolatile) continue; 2953 if ((CVR & Qualifiers::Restrict) && !hasRestrict) continue; 2954 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 2955 PointerTypes.insert(Context.getPointerType(QPointeeTy)); 2956 } 2957 2958 return true; 2959} 2960 2961/// AddMemberPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty 2962/// to the set of pointer types along with any more-qualified variants of 2963/// that type. For example, if @p Ty is "int const *", this routine 2964/// will add "int const *", "int const volatile *", "int const 2965/// restrict *", and "int const volatile restrict *" to the set of 2966/// pointer types. Returns true if the add of @p Ty itself succeeded, 2967/// false otherwise. 2968/// 2969/// FIXME: what to do about extended qualifiers? 2970bool 2971BuiltinCandidateTypeSet::AddMemberPointerWithMoreQualifiedTypeVariants( 2972 QualType Ty) { 2973 // Insert this type. 2974 if (!MemberPointerTypes.insert(Ty)) 2975 return false; 2976 2977 const MemberPointerType *PointerTy = Ty->getAs<MemberPointerType>(); 2978 assert(PointerTy && "type was not a member pointer type!"); 2979 2980 QualType PointeeTy = PointerTy->getPointeeType(); 2981 const Type *ClassTy = PointerTy->getClass(); 2982 2983 // Iterate through all strict supersets of the pointee type's CVR 2984 // qualifiers. 2985 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 2986 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 2987 if ((CVR | BaseCVR) != CVR) continue; 2988 2989 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 2990 MemberPointerTypes.insert(Context.getMemberPointerType(QPointeeTy, ClassTy)); 2991 } 2992 2993 return true; 2994} 2995 2996/// AddTypesConvertedFrom - Add each of the types to which the type @p 2997/// Ty can be implicit converted to the given set of @p Types. We're 2998/// primarily interested in pointer types and enumeration types. We also 2999/// take member pointer types, for the conditional operator. 3000/// AllowUserConversions is true if we should look at the conversion 3001/// functions of a class type, and AllowExplicitConversions if we 3002/// should also include the explicit conversion functions of a class 3003/// type. 3004void 3005BuiltinCandidateTypeSet::AddTypesConvertedFrom(QualType Ty, 3006 bool AllowUserConversions, 3007 bool AllowExplicitConversions, 3008 const Qualifiers &VisibleQuals) { 3009 // Only deal with canonical types. 3010 Ty = Context.getCanonicalType(Ty); 3011 3012 // Look through reference types; they aren't part of the type of an 3013 // expression for the purposes of conversions. 3014 if (const ReferenceType *RefTy = Ty->getAs<ReferenceType>()) 3015 Ty = RefTy->getPointeeType(); 3016 3017 // We don't care about qualifiers on the type. 3018 Ty = Ty.getUnqualifiedType(); 3019 3020 if (const PointerType *PointerTy = Ty->getAs<PointerType>()) { 3021 QualType PointeeTy = PointerTy->getPointeeType(); 3022 3023 // Insert our type, and its more-qualified variants, into the set 3024 // of types. 3025 if (!AddPointerWithMoreQualifiedTypeVariants(Ty, VisibleQuals)) 3026 return; 3027 3028 // Add 'cv void*' to our set of types. 3029 if (!Ty->isVoidType()) { 3030 QualType QualVoid 3031 = Context.getCVRQualifiedType(Context.VoidTy, 3032 PointeeTy.getCVRQualifiers()); 3033 AddPointerWithMoreQualifiedTypeVariants(Context.getPointerType(QualVoid), 3034 VisibleQuals); 3035 } 3036 3037 // If this is a pointer to a class type, add pointers to its bases 3038 // (with the same level of cv-qualification as the original 3039 // derived class, of course). 3040 if (const RecordType *PointeeRec = PointeeTy->getAs<RecordType>()) { 3041 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(PointeeRec->getDecl()); 3042 for (CXXRecordDecl::base_class_iterator Base = ClassDecl->bases_begin(); 3043 Base != ClassDecl->bases_end(); ++Base) { 3044 QualType BaseTy = Context.getCanonicalType(Base->getType()); 3045 BaseTy = Context.getCVRQualifiedType(BaseTy.getUnqualifiedType(), 3046 PointeeTy.getCVRQualifiers()); 3047 // Add the pointer type, recursively, so that we get all of 3048 // the indirect base classes, too. 3049 AddTypesConvertedFrom(Context.getPointerType(BaseTy), false, false, 3050 VisibleQuals); 3051 } 3052 } 3053 } else if (Ty->isMemberPointerType()) { 3054 // Member pointers are far easier, since the pointee can't be converted. 3055 if (!AddMemberPointerWithMoreQualifiedTypeVariants(Ty)) 3056 return; 3057 } else if (Ty->isEnumeralType()) { 3058 EnumerationTypes.insert(Ty); 3059 } else if (AllowUserConversions) { 3060 if (const RecordType *TyRec = Ty->getAs<RecordType>()) { 3061 if (SemaRef.RequireCompleteType(SourceLocation(), Ty, 0)) { 3062 // No conversion functions in incomplete types. 3063 return; 3064 } 3065 3066 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 3067 OverloadedFunctionDecl *Conversions 3068 = ClassDecl->getVisibleConversionFunctions(); 3069 for (OverloadedFunctionDecl::function_iterator Func 3070 = Conversions->function_begin(); 3071 Func != Conversions->function_end(); ++Func) { 3072 CXXConversionDecl *Conv; 3073 FunctionTemplateDecl *ConvTemplate; 3074 GetFunctionAndTemplate(*Func, Conv, ConvTemplate); 3075 3076 // Skip conversion function templates; they don't tell us anything 3077 // about which builtin types we can convert to. 3078 if (ConvTemplate) 3079 continue; 3080 3081 if (AllowExplicitConversions || !Conv->isExplicit()) { 3082 AddTypesConvertedFrom(Conv->getConversionType(), false, false, 3083 VisibleQuals); 3084 } 3085 } 3086 } 3087 } 3088} 3089 3090/// \brief Helper function for AddBuiltinOperatorCandidates() that adds 3091/// the volatile- and non-volatile-qualified assignment operators for the 3092/// given type to the candidate set. 3093static void AddBuiltinAssignmentOperatorCandidates(Sema &S, 3094 QualType T, 3095 Expr **Args, 3096 unsigned NumArgs, 3097 OverloadCandidateSet &CandidateSet) { 3098 QualType ParamTypes[2]; 3099 3100 // T& operator=(T&, T) 3101 ParamTypes[0] = S.Context.getLValueReferenceType(T); 3102 ParamTypes[1] = T; 3103 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3104 /*IsAssignmentOperator=*/true); 3105 3106 if (!S.Context.getCanonicalType(T).isVolatileQualified()) { 3107 // volatile T& operator=(volatile T&, T) 3108 ParamTypes[0] 3109 = S.Context.getLValueReferenceType(S.Context.getVolatileType(T)); 3110 ParamTypes[1] = T; 3111 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3112 /*IsAssignmentOperator=*/true); 3113 } 3114} 3115 3116/// CollectVRQualifiers - This routine returns Volatile/Restrict qualifiers 3117/// , if any, found in visible type conversion functions found in ArgExpr's 3118/// type. 3119static Qualifiers CollectVRQualifiers(ASTContext &Context, Expr* ArgExpr) { 3120 Qualifiers VRQuals; 3121 const RecordType *TyRec; 3122 if (const MemberPointerType *RHSMPType = 3123 ArgExpr->getType()->getAs<MemberPointerType>()) 3124 TyRec = cast<RecordType>(RHSMPType->getClass()); 3125 else 3126 TyRec = ArgExpr->getType()->getAs<RecordType>(); 3127 if (!TyRec) { 3128 // Just to be safe, assume the worst case. 3129 VRQuals.addVolatile(); 3130 VRQuals.addRestrict(); 3131 return VRQuals; 3132 } 3133 3134 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 3135 OverloadedFunctionDecl *Conversions = 3136 ClassDecl->getVisibleConversionFunctions(); 3137 3138 for (OverloadedFunctionDecl::function_iterator Func 3139 = Conversions->function_begin(); 3140 Func != Conversions->function_end(); ++Func) { 3141 if (CXXConversionDecl *Conv = dyn_cast<CXXConversionDecl>(*Func)) { 3142 QualType CanTy = Context.getCanonicalType(Conv->getConversionType()); 3143 if (const ReferenceType *ResTypeRef = CanTy->getAs<ReferenceType>()) 3144 CanTy = ResTypeRef->getPointeeType(); 3145 // Need to go down the pointer/mempointer chain and add qualifiers 3146 // as see them. 3147 bool done = false; 3148 while (!done) { 3149 if (const PointerType *ResTypePtr = CanTy->getAs<PointerType>()) 3150 CanTy = ResTypePtr->getPointeeType(); 3151 else if (const MemberPointerType *ResTypeMPtr = 3152 CanTy->getAs<MemberPointerType>()) 3153 CanTy = ResTypeMPtr->getPointeeType(); 3154 else 3155 done = true; 3156 if (CanTy.isVolatileQualified()) 3157 VRQuals.addVolatile(); 3158 if (CanTy.isRestrictQualified()) 3159 VRQuals.addRestrict(); 3160 if (VRQuals.hasRestrict() && VRQuals.hasVolatile()) 3161 return VRQuals; 3162 } 3163 } 3164 } 3165 return VRQuals; 3166} 3167 3168/// AddBuiltinOperatorCandidates - Add the appropriate built-in 3169/// operator overloads to the candidate set (C++ [over.built]), based 3170/// on the operator @p Op and the arguments given. For example, if the 3171/// operator is a binary '+', this routine might add "int 3172/// operator+(int, int)" to cover integer addition. 3173void 3174Sema::AddBuiltinOperatorCandidates(OverloadedOperatorKind Op, 3175 Expr **Args, unsigned NumArgs, 3176 OverloadCandidateSet& CandidateSet) { 3177 // The set of "promoted arithmetic types", which are the arithmetic 3178 // types are that preserved by promotion (C++ [over.built]p2). Note 3179 // that the first few of these types are the promoted integral 3180 // types; these types need to be first. 3181 // FIXME: What about complex? 3182 const unsigned FirstIntegralType = 0; 3183 const unsigned LastIntegralType = 13; 3184 const unsigned FirstPromotedIntegralType = 7, 3185 LastPromotedIntegralType = 13; 3186 const unsigned FirstPromotedArithmeticType = 7, 3187 LastPromotedArithmeticType = 16; 3188 const unsigned NumArithmeticTypes = 16; 3189 QualType ArithmeticTypes[NumArithmeticTypes] = { 3190 Context.BoolTy, Context.CharTy, Context.WCharTy, 3191// FIXME: Context.Char16Ty, Context.Char32Ty, 3192 Context.SignedCharTy, Context.ShortTy, 3193 Context.UnsignedCharTy, Context.UnsignedShortTy, 3194 Context.IntTy, Context.LongTy, Context.LongLongTy, 3195 Context.UnsignedIntTy, Context.UnsignedLongTy, Context.UnsignedLongLongTy, 3196 Context.FloatTy, Context.DoubleTy, Context.LongDoubleTy 3197 }; 3198 3199 // Find all of the types that the arguments can convert to, but only 3200 // if the operator we're looking at has built-in operator candidates 3201 // that make use of these types. 3202 Qualifiers VisibleTypeConversionsQuals; 3203 VisibleTypeConversionsQuals.addConst(); 3204 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 3205 VisibleTypeConversionsQuals += CollectVRQualifiers(Context, Args[ArgIdx]); 3206 3207 BuiltinCandidateTypeSet CandidateTypes(*this); 3208 if (Op == OO_Less || Op == OO_Greater || Op == OO_LessEqual || 3209 Op == OO_GreaterEqual || Op == OO_EqualEqual || Op == OO_ExclaimEqual || 3210 Op == OO_Plus || (Op == OO_Minus && NumArgs == 2) || Op == OO_Equal || 3211 Op == OO_PlusEqual || Op == OO_MinusEqual || Op == OO_Subscript || 3212 Op == OO_ArrowStar || Op == OO_PlusPlus || Op == OO_MinusMinus || 3213 (Op == OO_Star && NumArgs == 1) || Op == OO_Conditional) { 3214 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 3215 CandidateTypes.AddTypesConvertedFrom(Args[ArgIdx]->getType(), 3216 true, 3217 (Op == OO_Exclaim || 3218 Op == OO_AmpAmp || 3219 Op == OO_PipePipe), 3220 VisibleTypeConversionsQuals); 3221 } 3222 3223 bool isComparison = false; 3224 switch (Op) { 3225 case OO_None: 3226 case NUM_OVERLOADED_OPERATORS: 3227 assert(false && "Expected an overloaded operator"); 3228 break; 3229 3230 case OO_Star: // '*' is either unary or binary 3231 if (NumArgs == 1) 3232 goto UnaryStar; 3233 else 3234 goto BinaryStar; 3235 break; 3236 3237 case OO_Plus: // '+' is either unary or binary 3238 if (NumArgs == 1) 3239 goto UnaryPlus; 3240 else 3241 goto BinaryPlus; 3242 break; 3243 3244 case OO_Minus: // '-' is either unary or binary 3245 if (NumArgs == 1) 3246 goto UnaryMinus; 3247 else 3248 goto BinaryMinus; 3249 break; 3250 3251 case OO_Amp: // '&' is either unary or binary 3252 if (NumArgs == 1) 3253 goto UnaryAmp; 3254 else 3255 goto BinaryAmp; 3256 3257 case OO_PlusPlus: 3258 case OO_MinusMinus: 3259 // C++ [over.built]p3: 3260 // 3261 // For every pair (T, VQ), where T is an arithmetic type, and VQ 3262 // is either volatile or empty, there exist candidate operator 3263 // functions of the form 3264 // 3265 // VQ T& operator++(VQ T&); 3266 // T operator++(VQ T&, int); 3267 // 3268 // C++ [over.built]p4: 3269 // 3270 // For every pair (T, VQ), where T is an arithmetic type other 3271 // than bool, and VQ is either volatile or empty, there exist 3272 // candidate operator functions of the form 3273 // 3274 // VQ T& operator--(VQ T&); 3275 // T operator--(VQ T&, int); 3276 for (unsigned Arith = (Op == OO_PlusPlus? 0 : 1); 3277 Arith < NumArithmeticTypes; ++Arith) { 3278 QualType ArithTy = ArithmeticTypes[Arith]; 3279 QualType ParamTypes[2] 3280 = { Context.getLValueReferenceType(ArithTy), Context.IntTy }; 3281 3282 // Non-volatile version. 3283 if (NumArgs == 1) 3284 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3285 else 3286 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 3287 // heuristic to reduce number of builtin candidates in the set. 3288 // Add volatile version only if there are conversions to a volatile type. 3289 if (VisibleTypeConversionsQuals.hasVolatile()) { 3290 // Volatile version 3291 ParamTypes[0] 3292 = Context.getLValueReferenceType(Context.getVolatileType(ArithTy)); 3293 if (NumArgs == 1) 3294 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3295 else 3296 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 3297 } 3298 } 3299 3300 // C++ [over.built]p5: 3301 // 3302 // For every pair (T, VQ), where T is a cv-qualified or 3303 // cv-unqualified object type, and VQ is either volatile or 3304 // empty, there exist candidate operator functions of the form 3305 // 3306 // T*VQ& operator++(T*VQ&); 3307 // T*VQ& operator--(T*VQ&); 3308 // T* operator++(T*VQ&, int); 3309 // T* operator--(T*VQ&, int); 3310 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3311 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3312 // Skip pointer types that aren't pointers to object types. 3313 if (!(*Ptr)->getAs<PointerType>()->getPointeeType()->isObjectType()) 3314 continue; 3315 3316 QualType ParamTypes[2] = { 3317 Context.getLValueReferenceType(*Ptr), Context.IntTy 3318 }; 3319 3320 // Without volatile 3321 if (NumArgs == 1) 3322 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3323 else 3324 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3325 3326 if (!Context.getCanonicalType(*Ptr).isVolatileQualified() && 3327 VisibleTypeConversionsQuals.hasVolatile()) { 3328 // With volatile 3329 ParamTypes[0] 3330 = Context.getLValueReferenceType(Context.getVolatileType(*Ptr)); 3331 if (NumArgs == 1) 3332 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 3333 else 3334 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3335 } 3336 } 3337 break; 3338 3339 UnaryStar: 3340 // C++ [over.built]p6: 3341 // For every cv-qualified or cv-unqualified object type T, there 3342 // exist candidate operator functions of the form 3343 // 3344 // T& operator*(T*); 3345 // 3346 // C++ [over.built]p7: 3347 // For every function type T, there exist candidate operator 3348 // functions of the form 3349 // T& operator*(T*); 3350 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3351 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3352 QualType ParamTy = *Ptr; 3353 QualType PointeeTy = ParamTy->getAs<PointerType>()->getPointeeType(); 3354 AddBuiltinCandidate(Context.getLValueReferenceType(PointeeTy), 3355 &ParamTy, Args, 1, CandidateSet); 3356 } 3357 break; 3358 3359 UnaryPlus: 3360 // C++ [over.built]p8: 3361 // For every type T, there exist candidate operator functions of 3362 // the form 3363 // 3364 // T* operator+(T*); 3365 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3366 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3367 QualType ParamTy = *Ptr; 3368 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet); 3369 } 3370 3371 // Fall through 3372 3373 UnaryMinus: 3374 // C++ [over.built]p9: 3375 // For every promoted arithmetic type T, there exist candidate 3376 // operator functions of the form 3377 // 3378 // T operator+(T); 3379 // T operator-(T); 3380 for (unsigned Arith = FirstPromotedArithmeticType; 3381 Arith < LastPromotedArithmeticType; ++Arith) { 3382 QualType ArithTy = ArithmeticTypes[Arith]; 3383 AddBuiltinCandidate(ArithTy, &ArithTy, Args, 1, CandidateSet); 3384 } 3385 break; 3386 3387 case OO_Tilde: 3388 // C++ [over.built]p10: 3389 // For every promoted integral type T, there exist candidate 3390 // operator functions of the form 3391 // 3392 // T operator~(T); 3393 for (unsigned Int = FirstPromotedIntegralType; 3394 Int < LastPromotedIntegralType; ++Int) { 3395 QualType IntTy = ArithmeticTypes[Int]; 3396 AddBuiltinCandidate(IntTy, &IntTy, Args, 1, CandidateSet); 3397 } 3398 break; 3399 3400 case OO_New: 3401 case OO_Delete: 3402 case OO_Array_New: 3403 case OO_Array_Delete: 3404 case OO_Call: 3405 assert(false && "Special operators don't use AddBuiltinOperatorCandidates"); 3406 break; 3407 3408 case OO_Comma: 3409 UnaryAmp: 3410 case OO_Arrow: 3411 // C++ [over.match.oper]p3: 3412 // -- For the operator ',', the unary operator '&', or the 3413 // operator '->', the built-in candidates set is empty. 3414 break; 3415 3416 case OO_EqualEqual: 3417 case OO_ExclaimEqual: 3418 // C++ [over.match.oper]p16: 3419 // For every pointer to member type T, there exist candidate operator 3420 // functions of the form 3421 // 3422 // bool operator==(T,T); 3423 // bool operator!=(T,T); 3424 for (BuiltinCandidateTypeSet::iterator 3425 MemPtr = CandidateTypes.member_pointer_begin(), 3426 MemPtrEnd = CandidateTypes.member_pointer_end(); 3427 MemPtr != MemPtrEnd; 3428 ++MemPtr) { 3429 QualType ParamTypes[2] = { *MemPtr, *MemPtr }; 3430 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 3431 } 3432 3433 // Fall through 3434 3435 case OO_Less: 3436 case OO_Greater: 3437 case OO_LessEqual: 3438 case OO_GreaterEqual: 3439 // C++ [over.built]p15: 3440 // 3441 // For every pointer or enumeration type T, there exist 3442 // candidate operator functions of the form 3443 // 3444 // bool operator<(T, T); 3445 // bool operator>(T, T); 3446 // bool operator<=(T, T); 3447 // bool operator>=(T, T); 3448 // bool operator==(T, T); 3449 // bool operator!=(T, T); 3450 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3451 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3452 QualType ParamTypes[2] = { *Ptr, *Ptr }; 3453 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 3454 } 3455 for (BuiltinCandidateTypeSet::iterator Enum 3456 = CandidateTypes.enumeration_begin(); 3457 Enum != CandidateTypes.enumeration_end(); ++Enum) { 3458 QualType ParamTypes[2] = { *Enum, *Enum }; 3459 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 3460 } 3461 3462 // Fall through. 3463 isComparison = true; 3464 3465 BinaryPlus: 3466 BinaryMinus: 3467 if (!isComparison) { 3468 // We didn't fall through, so we must have OO_Plus or OO_Minus. 3469 3470 // C++ [over.built]p13: 3471 // 3472 // For every cv-qualified or cv-unqualified object type T 3473 // there exist candidate operator functions of the form 3474 // 3475 // T* operator+(T*, ptrdiff_t); 3476 // T& operator[](T*, ptrdiff_t); [BELOW] 3477 // T* operator-(T*, ptrdiff_t); 3478 // T* operator+(ptrdiff_t, T*); 3479 // T& operator[](ptrdiff_t, T*); [BELOW] 3480 // 3481 // C++ [over.built]p14: 3482 // 3483 // For every T, where T is a pointer to object type, there 3484 // exist candidate operator functions of the form 3485 // 3486 // ptrdiff_t operator-(T, T); 3487 for (BuiltinCandidateTypeSet::iterator Ptr 3488 = CandidateTypes.pointer_begin(); 3489 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3490 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 3491 3492 // operator+(T*, ptrdiff_t) or operator-(T*, ptrdiff_t) 3493 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3494 3495 if (Op == OO_Plus) { 3496 // T* operator+(ptrdiff_t, T*); 3497 ParamTypes[0] = ParamTypes[1]; 3498 ParamTypes[1] = *Ptr; 3499 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3500 } else { 3501 // ptrdiff_t operator-(T, T); 3502 ParamTypes[1] = *Ptr; 3503 AddBuiltinCandidate(Context.getPointerDiffType(), ParamTypes, 3504 Args, 2, CandidateSet); 3505 } 3506 } 3507 } 3508 // Fall through 3509 3510 case OO_Slash: 3511 BinaryStar: 3512 Conditional: 3513 // C++ [over.built]p12: 3514 // 3515 // For every pair of promoted arithmetic types L and R, there 3516 // exist candidate operator functions of the form 3517 // 3518 // LR operator*(L, R); 3519 // LR operator/(L, R); 3520 // LR operator+(L, R); 3521 // LR operator-(L, R); 3522 // bool operator<(L, R); 3523 // bool operator>(L, R); 3524 // bool operator<=(L, R); 3525 // bool operator>=(L, R); 3526 // bool operator==(L, R); 3527 // bool operator!=(L, R); 3528 // 3529 // where LR is the result of the usual arithmetic conversions 3530 // between types L and R. 3531 // 3532 // C++ [over.built]p24: 3533 // 3534 // For every pair of promoted arithmetic types L and R, there exist 3535 // candidate operator functions of the form 3536 // 3537 // LR operator?(bool, L, R); 3538 // 3539 // where LR is the result of the usual arithmetic conversions 3540 // between types L and R. 3541 // Our candidates ignore the first parameter. 3542 for (unsigned Left = FirstPromotedArithmeticType; 3543 Left < LastPromotedArithmeticType; ++Left) { 3544 for (unsigned Right = FirstPromotedArithmeticType; 3545 Right < LastPromotedArithmeticType; ++Right) { 3546 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 3547 QualType Result 3548 = isComparison 3549 ? Context.BoolTy 3550 : Context.UsualArithmeticConversionsType(LandR[0], LandR[1]); 3551 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 3552 } 3553 } 3554 break; 3555 3556 case OO_Percent: 3557 BinaryAmp: 3558 case OO_Caret: 3559 case OO_Pipe: 3560 case OO_LessLess: 3561 case OO_GreaterGreater: 3562 // C++ [over.built]p17: 3563 // 3564 // For every pair of promoted integral types L and R, there 3565 // exist candidate operator functions of the form 3566 // 3567 // LR operator%(L, R); 3568 // LR operator&(L, R); 3569 // LR operator^(L, R); 3570 // LR operator|(L, R); 3571 // L operator<<(L, R); 3572 // L operator>>(L, R); 3573 // 3574 // where LR is the result of the usual arithmetic conversions 3575 // between types L and R. 3576 for (unsigned Left = FirstPromotedIntegralType; 3577 Left < LastPromotedIntegralType; ++Left) { 3578 for (unsigned Right = FirstPromotedIntegralType; 3579 Right < LastPromotedIntegralType; ++Right) { 3580 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 3581 QualType Result = (Op == OO_LessLess || Op == OO_GreaterGreater) 3582 ? LandR[0] 3583 : Context.UsualArithmeticConversionsType(LandR[0], LandR[1]); 3584 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 3585 } 3586 } 3587 break; 3588 3589 case OO_Equal: 3590 // C++ [over.built]p20: 3591 // 3592 // For every pair (T, VQ), where T is an enumeration or 3593 // pointer to member type and VQ is either volatile or 3594 // empty, there exist candidate operator functions of the form 3595 // 3596 // VQ T& operator=(VQ T&, T); 3597 for (BuiltinCandidateTypeSet::iterator 3598 Enum = CandidateTypes.enumeration_begin(), 3599 EnumEnd = CandidateTypes.enumeration_end(); 3600 Enum != EnumEnd; ++Enum) 3601 AddBuiltinAssignmentOperatorCandidates(*this, *Enum, Args, 2, 3602 CandidateSet); 3603 for (BuiltinCandidateTypeSet::iterator 3604 MemPtr = CandidateTypes.member_pointer_begin(), 3605 MemPtrEnd = CandidateTypes.member_pointer_end(); 3606 MemPtr != MemPtrEnd; ++MemPtr) 3607 AddBuiltinAssignmentOperatorCandidates(*this, *MemPtr, Args, 2, 3608 CandidateSet); 3609 // Fall through. 3610 3611 case OO_PlusEqual: 3612 case OO_MinusEqual: 3613 // C++ [over.built]p19: 3614 // 3615 // For every pair (T, VQ), where T is any type and VQ is either 3616 // volatile or empty, there exist candidate operator functions 3617 // of the form 3618 // 3619 // T*VQ& operator=(T*VQ&, T*); 3620 // 3621 // C++ [over.built]p21: 3622 // 3623 // For every pair (T, VQ), where T is a cv-qualified or 3624 // cv-unqualified object type and VQ is either volatile or 3625 // empty, there exist candidate operator functions of the form 3626 // 3627 // T*VQ& operator+=(T*VQ&, ptrdiff_t); 3628 // T*VQ& operator-=(T*VQ&, ptrdiff_t); 3629 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3630 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3631 QualType ParamTypes[2]; 3632 ParamTypes[1] = (Op == OO_Equal)? *Ptr : Context.getPointerDiffType(); 3633 3634 // non-volatile version 3635 ParamTypes[0] = Context.getLValueReferenceType(*Ptr); 3636 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3637 /*IsAssigmentOperator=*/Op == OO_Equal); 3638 3639 if (!Context.getCanonicalType(*Ptr).isVolatileQualified() && 3640 VisibleTypeConversionsQuals.hasVolatile()) { 3641 // volatile version 3642 ParamTypes[0] 3643 = Context.getLValueReferenceType(Context.getVolatileType(*Ptr)); 3644 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3645 /*IsAssigmentOperator=*/Op == OO_Equal); 3646 } 3647 } 3648 // Fall through. 3649 3650 case OO_StarEqual: 3651 case OO_SlashEqual: 3652 // C++ [over.built]p18: 3653 // 3654 // For every triple (L, VQ, R), where L is an arithmetic type, 3655 // VQ is either volatile or empty, and R is a promoted 3656 // arithmetic type, there exist candidate operator functions of 3657 // the form 3658 // 3659 // VQ L& operator=(VQ L&, R); 3660 // VQ L& operator*=(VQ L&, R); 3661 // VQ L& operator/=(VQ L&, R); 3662 // VQ L& operator+=(VQ L&, R); 3663 // VQ L& operator-=(VQ L&, R); 3664 for (unsigned Left = 0; Left < NumArithmeticTypes; ++Left) { 3665 for (unsigned Right = FirstPromotedArithmeticType; 3666 Right < LastPromotedArithmeticType; ++Right) { 3667 QualType ParamTypes[2]; 3668 ParamTypes[1] = ArithmeticTypes[Right]; 3669 3670 // Add this built-in operator as a candidate (VQ is empty). 3671 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 3672 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3673 /*IsAssigmentOperator=*/Op == OO_Equal); 3674 3675 // Add this built-in operator as a candidate (VQ is 'volatile'). 3676 if (VisibleTypeConversionsQuals.hasVolatile()) { 3677 ParamTypes[0] = Context.getVolatileType(ArithmeticTypes[Left]); 3678 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 3679 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 3680 /*IsAssigmentOperator=*/Op == OO_Equal); 3681 } 3682 } 3683 } 3684 break; 3685 3686 case OO_PercentEqual: 3687 case OO_LessLessEqual: 3688 case OO_GreaterGreaterEqual: 3689 case OO_AmpEqual: 3690 case OO_CaretEqual: 3691 case OO_PipeEqual: 3692 // C++ [over.built]p22: 3693 // 3694 // For every triple (L, VQ, R), where L is an integral type, VQ 3695 // is either volatile or empty, and R is a promoted integral 3696 // type, there exist candidate operator functions of the form 3697 // 3698 // VQ L& operator%=(VQ L&, R); 3699 // VQ L& operator<<=(VQ L&, R); 3700 // VQ L& operator>>=(VQ L&, R); 3701 // VQ L& operator&=(VQ L&, R); 3702 // VQ L& operator^=(VQ L&, R); 3703 // VQ L& operator|=(VQ L&, R); 3704 for (unsigned Left = FirstIntegralType; Left < LastIntegralType; ++Left) { 3705 for (unsigned Right = FirstPromotedIntegralType; 3706 Right < LastPromotedIntegralType; ++Right) { 3707 QualType ParamTypes[2]; 3708 ParamTypes[1] = ArithmeticTypes[Right]; 3709 3710 // Add this built-in operator as a candidate (VQ is empty). 3711 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 3712 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 3713 3714 // Add this built-in operator as a candidate (VQ is 'volatile'). 3715 ParamTypes[0] = ArithmeticTypes[Left]; 3716 ParamTypes[0] = Context.getVolatileType(ParamTypes[0]); 3717 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 3718 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 3719 } 3720 } 3721 break; 3722 3723 case OO_Exclaim: { 3724 // C++ [over.operator]p23: 3725 // 3726 // There also exist candidate operator functions of the form 3727 // 3728 // bool operator!(bool); 3729 // bool operator&&(bool, bool); [BELOW] 3730 // bool operator||(bool, bool); [BELOW] 3731 QualType ParamTy = Context.BoolTy; 3732 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet, 3733 /*IsAssignmentOperator=*/false, 3734 /*NumContextualBoolArguments=*/1); 3735 break; 3736 } 3737 3738 case OO_AmpAmp: 3739 case OO_PipePipe: { 3740 // C++ [over.operator]p23: 3741 // 3742 // There also exist candidate operator functions of the form 3743 // 3744 // bool operator!(bool); [ABOVE] 3745 // bool operator&&(bool, bool); 3746 // bool operator||(bool, bool); 3747 QualType ParamTypes[2] = { Context.BoolTy, Context.BoolTy }; 3748 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet, 3749 /*IsAssignmentOperator=*/false, 3750 /*NumContextualBoolArguments=*/2); 3751 break; 3752 } 3753 3754 case OO_Subscript: 3755 // C++ [over.built]p13: 3756 // 3757 // For every cv-qualified or cv-unqualified object type T there 3758 // exist candidate operator functions of the form 3759 // 3760 // T* operator+(T*, ptrdiff_t); [ABOVE] 3761 // T& operator[](T*, ptrdiff_t); 3762 // T* operator-(T*, ptrdiff_t); [ABOVE] 3763 // T* operator+(ptrdiff_t, T*); [ABOVE] 3764 // T& operator[](ptrdiff_t, T*); 3765 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 3766 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3767 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 3768 QualType PointeeType = (*Ptr)->getAs<PointerType>()->getPointeeType(); 3769 QualType ResultTy = Context.getLValueReferenceType(PointeeType); 3770 3771 // T& operator[](T*, ptrdiff_t) 3772 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 3773 3774 // T& operator[](ptrdiff_t, T*); 3775 ParamTypes[0] = ParamTypes[1]; 3776 ParamTypes[1] = *Ptr; 3777 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 3778 } 3779 break; 3780 3781 case OO_ArrowStar: 3782 // C++ [over.built]p11: 3783 // For every quintuple (C1, C2, T, CV1, CV2), where C2 is a class type, 3784 // C1 is the same type as C2 or is a derived class of C2, T is an object 3785 // type or a function type, and CV1 and CV2 are cv-qualifier-seqs, 3786 // there exist candidate operator functions of the form 3787 // CV12 T& operator->*(CV1 C1*, CV2 T C2::*); 3788 // where CV12 is the union of CV1 and CV2. 3789 { 3790 for (BuiltinCandidateTypeSet::iterator Ptr = 3791 CandidateTypes.pointer_begin(); 3792 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 3793 QualType C1Ty = (*Ptr); 3794 QualType C1; 3795 QualifierCollector Q1; 3796 if (const PointerType *PointerTy = C1Ty->getAs<PointerType>()) { 3797 C1 = QualType(Q1.strip(PointerTy->getPointeeType()), 0); 3798 if (!isa<RecordType>(C1)) 3799 continue; 3800 // heuristic to reduce number of builtin candidates in the set. 3801 // Add volatile/restrict version only if there are conversions to a 3802 // volatile/restrict type. 3803 if (!VisibleTypeConversionsQuals.hasVolatile() && Q1.hasVolatile()) 3804 continue; 3805 if (!VisibleTypeConversionsQuals.hasRestrict() && Q1.hasRestrict()) 3806 continue; 3807 } 3808 for (BuiltinCandidateTypeSet::iterator 3809 MemPtr = CandidateTypes.member_pointer_begin(), 3810 MemPtrEnd = CandidateTypes.member_pointer_end(); 3811 MemPtr != MemPtrEnd; ++MemPtr) { 3812 const MemberPointerType *mptr = cast<MemberPointerType>(*MemPtr); 3813 QualType C2 = QualType(mptr->getClass(), 0); 3814 C2 = C2.getUnqualifiedType(); 3815 if (C1 != C2 && !IsDerivedFrom(C1, C2)) 3816 break; 3817 QualType ParamTypes[2] = { *Ptr, *MemPtr }; 3818 // build CV12 T& 3819 QualType T = mptr->getPointeeType(); 3820 if (!VisibleTypeConversionsQuals.hasVolatile() && 3821 T.isVolatileQualified()) 3822 continue; 3823 if (!VisibleTypeConversionsQuals.hasRestrict() && 3824 T.isRestrictQualified()) 3825 continue; 3826 T = Q1.apply(T); 3827 QualType ResultTy = Context.getLValueReferenceType(T); 3828 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 3829 } 3830 } 3831 } 3832 break; 3833 3834 case OO_Conditional: 3835 // Note that we don't consider the first argument, since it has been 3836 // contextually converted to bool long ago. The candidates below are 3837 // therefore added as binary. 3838 // 3839 // C++ [over.built]p24: 3840 // For every type T, where T is a pointer or pointer-to-member type, 3841 // there exist candidate operator functions of the form 3842 // 3843 // T operator?(bool, T, T); 3844 // 3845 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(), 3846 E = CandidateTypes.pointer_end(); Ptr != E; ++Ptr) { 3847 QualType ParamTypes[2] = { *Ptr, *Ptr }; 3848 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3849 } 3850 for (BuiltinCandidateTypeSet::iterator Ptr = 3851 CandidateTypes.member_pointer_begin(), 3852 E = CandidateTypes.member_pointer_end(); Ptr != E; ++Ptr) { 3853 QualType ParamTypes[2] = { *Ptr, *Ptr }; 3854 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 3855 } 3856 goto Conditional; 3857 } 3858} 3859 3860/// \brief Add function candidates found via argument-dependent lookup 3861/// to the set of overloading candidates. 3862/// 3863/// This routine performs argument-dependent name lookup based on the 3864/// given function name (which may also be an operator name) and adds 3865/// all of the overload candidates found by ADL to the overload 3866/// candidate set (C++ [basic.lookup.argdep]). 3867void 3868Sema::AddArgumentDependentLookupCandidates(DeclarationName Name, 3869 Expr **Args, unsigned NumArgs, 3870 bool HasExplicitTemplateArgs, 3871 const TemplateArgument *ExplicitTemplateArgs, 3872 unsigned NumExplicitTemplateArgs, 3873 OverloadCandidateSet& CandidateSet, 3874 bool PartialOverloading) { 3875 FunctionSet Functions; 3876 3877 // FIXME: Should we be trafficking in canonical function decls throughout? 3878 3879 // Record all of the function candidates that we've already 3880 // added to the overload set, so that we don't add those same 3881 // candidates a second time. 3882 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 3883 CandEnd = CandidateSet.end(); 3884 Cand != CandEnd; ++Cand) 3885 if (Cand->Function) { 3886 Functions.insert(Cand->Function); 3887 if (FunctionTemplateDecl *FunTmpl = Cand->Function->getPrimaryTemplate()) 3888 Functions.insert(FunTmpl); 3889 } 3890 3891 // FIXME: Pass in the explicit template arguments? 3892 ArgumentDependentLookup(Name, Args, NumArgs, Functions); 3893 3894 // Erase all of the candidates we already knew about. 3895 // FIXME: This is suboptimal. Is there a better way? 3896 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 3897 CandEnd = CandidateSet.end(); 3898 Cand != CandEnd; ++Cand) 3899 if (Cand->Function) { 3900 Functions.erase(Cand->Function); 3901 if (FunctionTemplateDecl *FunTmpl = Cand->Function->getPrimaryTemplate()) 3902 Functions.erase(FunTmpl); 3903 } 3904 3905 // For each of the ADL candidates we found, add it to the overload 3906 // set. 3907 for (FunctionSet::iterator Func = Functions.begin(), 3908 FuncEnd = Functions.end(); 3909 Func != FuncEnd; ++Func) { 3910 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*Func)) { 3911 if (HasExplicitTemplateArgs) 3912 continue; 3913 3914 AddOverloadCandidate(FD, Args, NumArgs, CandidateSet, 3915 false, false, PartialOverloading); 3916 } else 3917 AddTemplateOverloadCandidate(cast<FunctionTemplateDecl>(*Func), 3918 HasExplicitTemplateArgs, 3919 ExplicitTemplateArgs, 3920 NumExplicitTemplateArgs, 3921 Args, NumArgs, CandidateSet); 3922 } 3923} 3924 3925/// isBetterOverloadCandidate - Determines whether the first overload 3926/// candidate is a better candidate than the second (C++ 13.3.3p1). 3927bool 3928Sema::isBetterOverloadCandidate(const OverloadCandidate& Cand1, 3929 const OverloadCandidate& Cand2) { 3930 // Define viable functions to be better candidates than non-viable 3931 // functions. 3932 if (!Cand2.Viable) 3933 return Cand1.Viable; 3934 else if (!Cand1.Viable) 3935 return false; 3936 3937 // C++ [over.match.best]p1: 3938 // 3939 // -- if F is a static member function, ICS1(F) is defined such 3940 // that ICS1(F) is neither better nor worse than ICS1(G) for 3941 // any function G, and, symmetrically, ICS1(G) is neither 3942 // better nor worse than ICS1(F). 3943 unsigned StartArg = 0; 3944 if (Cand1.IgnoreObjectArgument || Cand2.IgnoreObjectArgument) 3945 StartArg = 1; 3946 3947 // C++ [over.match.best]p1: 3948 // A viable function F1 is defined to be a better function than another 3949 // viable function F2 if for all arguments i, ICSi(F1) is not a worse 3950 // conversion sequence than ICSi(F2), and then... 3951 unsigned NumArgs = Cand1.Conversions.size(); 3952 assert(Cand2.Conversions.size() == NumArgs && "Overload candidate mismatch"); 3953 bool HasBetterConversion = false; 3954 for (unsigned ArgIdx = StartArg; ArgIdx < NumArgs; ++ArgIdx) { 3955 switch (CompareImplicitConversionSequences(Cand1.Conversions[ArgIdx], 3956 Cand2.Conversions[ArgIdx])) { 3957 case ImplicitConversionSequence::Better: 3958 // Cand1 has a better conversion sequence. 3959 HasBetterConversion = true; 3960 break; 3961 3962 case ImplicitConversionSequence::Worse: 3963 // Cand1 can't be better than Cand2. 3964 return false; 3965 3966 case ImplicitConversionSequence::Indistinguishable: 3967 // Do nothing. 3968 break; 3969 } 3970 } 3971 3972 // -- for some argument j, ICSj(F1) is a better conversion sequence than 3973 // ICSj(F2), or, if not that, 3974 if (HasBetterConversion) 3975 return true; 3976 3977 // - F1 is a non-template function and F2 is a function template 3978 // specialization, or, if not that, 3979 if (Cand1.Function && !Cand1.Function->getPrimaryTemplate() && 3980 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 3981 return true; 3982 3983 // -- F1 and F2 are function template specializations, and the function 3984 // template for F1 is more specialized than the template for F2 3985 // according to the partial ordering rules described in 14.5.5.2, or, 3986 // if not that, 3987 if (Cand1.Function && Cand1.Function->getPrimaryTemplate() && 3988 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 3989 if (FunctionTemplateDecl *BetterTemplate 3990 = getMoreSpecializedTemplate(Cand1.Function->getPrimaryTemplate(), 3991 Cand2.Function->getPrimaryTemplate(), 3992 isa<CXXConversionDecl>(Cand1.Function)? TPOC_Conversion 3993 : TPOC_Call)) 3994 return BetterTemplate == Cand1.Function->getPrimaryTemplate(); 3995 3996 // -- the context is an initialization by user-defined conversion 3997 // (see 8.5, 13.3.1.5) and the standard conversion sequence 3998 // from the return type of F1 to the destination type (i.e., 3999 // the type of the entity being initialized) is a better 4000 // conversion sequence than the standard conversion sequence 4001 // from the return type of F2 to the destination type. 4002 if (Cand1.Function && Cand2.Function && 4003 isa<CXXConversionDecl>(Cand1.Function) && 4004 isa<CXXConversionDecl>(Cand2.Function)) { 4005 switch (CompareStandardConversionSequences(Cand1.FinalConversion, 4006 Cand2.FinalConversion)) { 4007 case ImplicitConversionSequence::Better: 4008 // Cand1 has a better conversion sequence. 4009 return true; 4010 4011 case ImplicitConversionSequence::Worse: 4012 // Cand1 can't be better than Cand2. 4013 return false; 4014 4015 case ImplicitConversionSequence::Indistinguishable: 4016 // Do nothing 4017 break; 4018 } 4019 } 4020 4021 return false; 4022} 4023 4024/// \brief Computes the best viable function (C++ 13.3.3) 4025/// within an overload candidate set. 4026/// 4027/// \param CandidateSet the set of candidate functions. 4028/// 4029/// \param Loc the location of the function name (or operator symbol) for 4030/// which overload resolution occurs. 4031/// 4032/// \param Best f overload resolution was successful or found a deleted 4033/// function, Best points to the candidate function found. 4034/// 4035/// \returns The result of overload resolution. 4036Sema::OverloadingResult 4037Sema::BestViableFunction(OverloadCandidateSet& CandidateSet, 4038 SourceLocation Loc, 4039 OverloadCandidateSet::iterator& Best) { 4040 // Find the best viable function. 4041 Best = CandidateSet.end(); 4042 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 4043 Cand != CandidateSet.end(); ++Cand) { 4044 if (Cand->Viable) { 4045 if (Best == CandidateSet.end() || isBetterOverloadCandidate(*Cand, *Best)) 4046 Best = Cand; 4047 } 4048 } 4049 4050 // If we didn't find any viable functions, abort. 4051 if (Best == CandidateSet.end()) 4052 return OR_No_Viable_Function; 4053 4054 // Make sure that this function is better than every other viable 4055 // function. If not, we have an ambiguity. 4056 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 4057 Cand != CandidateSet.end(); ++Cand) { 4058 if (Cand->Viable && 4059 Cand != Best && 4060 !isBetterOverloadCandidate(*Best, *Cand)) { 4061 Best = CandidateSet.end(); 4062 return OR_Ambiguous; 4063 } 4064 } 4065 4066 // Best is the best viable function. 4067 if (Best->Function && 4068 (Best->Function->isDeleted() || 4069 Best->Function->getAttr<UnavailableAttr>())) 4070 return OR_Deleted; 4071 4072 // C++ [basic.def.odr]p2: 4073 // An overloaded function is used if it is selected by overload resolution 4074 // when referred to from a potentially-evaluated expression. [Note: this 4075 // covers calls to named functions (5.2.2), operator overloading 4076 // (clause 13), user-defined conversions (12.3.2), allocation function for 4077 // placement new (5.3.4), as well as non-default initialization (8.5). 4078 if (Best->Function) 4079 MarkDeclarationReferenced(Loc, Best->Function); 4080 return OR_Success; 4081} 4082 4083/// PrintOverloadCandidates - When overload resolution fails, prints 4084/// diagnostic messages containing the candidates in the candidate 4085/// set. If OnlyViable is true, only viable candidates will be printed. 4086void 4087Sema::PrintOverloadCandidates(OverloadCandidateSet& CandidateSet, 4088 bool OnlyViable, 4089 const char *Opc, 4090 SourceLocation OpLoc) { 4091 OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 4092 LastCand = CandidateSet.end(); 4093 bool Reported = false; 4094 for (; Cand != LastCand; ++Cand) { 4095 if (Cand->Viable || !OnlyViable) { 4096 if (Cand->Function) { 4097 if (Cand->Function->isDeleted() || 4098 Cand->Function->getAttr<UnavailableAttr>()) { 4099 // Deleted or "unavailable" function. 4100 Diag(Cand->Function->getLocation(), diag::err_ovl_candidate_deleted) 4101 << Cand->Function->isDeleted(); 4102 } else if (FunctionTemplateDecl *FunTmpl 4103 = Cand->Function->getPrimaryTemplate()) { 4104 // Function template specialization 4105 // FIXME: Give a better reason! 4106 Diag(Cand->Function->getLocation(), diag::err_ovl_template_candidate) 4107 << getTemplateArgumentBindingsText(FunTmpl->getTemplateParameters(), 4108 *Cand->Function->getTemplateSpecializationArgs()); 4109 } else { 4110 // Normal function 4111 bool errReported = false; 4112 if (!Cand->Viable && Cand->Conversions.size() > 0) { 4113 for (int i = Cand->Conversions.size()-1; i >= 0; i--) { 4114 const ImplicitConversionSequence &Conversion = 4115 Cand->Conversions[i]; 4116 if ((Conversion.ConversionKind != 4117 ImplicitConversionSequence::BadConversion) || 4118 Conversion.ConversionFunctionSet.size() == 0) 4119 continue; 4120 Diag(Cand->Function->getLocation(), 4121 diag::err_ovl_candidate_not_viable) << (i+1); 4122 errReported = true; 4123 for (int j = Conversion.ConversionFunctionSet.size()-1; 4124 j >= 0; j--) { 4125 FunctionDecl *Func = Conversion.ConversionFunctionSet[j]; 4126 Diag(Func->getLocation(), diag::err_ovl_candidate); 4127 } 4128 } 4129 } 4130 if (!errReported) 4131 Diag(Cand->Function->getLocation(), diag::err_ovl_candidate); 4132 } 4133 } else if (Cand->IsSurrogate) { 4134 // Desugar the type of the surrogate down to a function type, 4135 // retaining as many typedefs as possible while still showing 4136 // the function type (and, therefore, its parameter types). 4137 QualType FnType = Cand->Surrogate->getConversionType(); 4138 bool isLValueReference = false; 4139 bool isRValueReference = false; 4140 bool isPointer = false; 4141 if (const LValueReferenceType *FnTypeRef = 4142 FnType->getAs<LValueReferenceType>()) { 4143 FnType = FnTypeRef->getPointeeType(); 4144 isLValueReference = true; 4145 } else if (const RValueReferenceType *FnTypeRef = 4146 FnType->getAs<RValueReferenceType>()) { 4147 FnType = FnTypeRef->getPointeeType(); 4148 isRValueReference = true; 4149 } 4150 if (const PointerType *FnTypePtr = FnType->getAs<PointerType>()) { 4151 FnType = FnTypePtr->getPointeeType(); 4152 isPointer = true; 4153 } 4154 // Desugar down to a function type. 4155 FnType = QualType(FnType->getAs<FunctionType>(), 0); 4156 // Reconstruct the pointer/reference as appropriate. 4157 if (isPointer) FnType = Context.getPointerType(FnType); 4158 if (isRValueReference) FnType = Context.getRValueReferenceType(FnType); 4159 if (isLValueReference) FnType = Context.getLValueReferenceType(FnType); 4160 4161 Diag(Cand->Surrogate->getLocation(), diag::err_ovl_surrogate_cand) 4162 << FnType; 4163 } else if (OnlyViable) { 4164 assert(Cand->Conversions.size() <= 2 && 4165 "builtin-binary-operator-not-binary"); 4166 std::string TypeStr("operator"); 4167 TypeStr += Opc; 4168 TypeStr += "("; 4169 TypeStr += Cand->BuiltinTypes.ParamTypes[0].getAsString(); 4170 if (Cand->Conversions.size() == 1) { 4171 TypeStr += ")"; 4172 Diag(OpLoc, diag::err_ovl_builtin_unary_candidate) << TypeStr; 4173 } 4174 else { 4175 TypeStr += ", "; 4176 TypeStr += Cand->BuiltinTypes.ParamTypes[1].getAsString(); 4177 TypeStr += ")"; 4178 Diag(OpLoc, diag::err_ovl_builtin_binary_candidate) << TypeStr; 4179 } 4180 } 4181 else if (!Cand->Viable && !Reported) { 4182 // Non-viability might be due to ambiguous user-defined conversions, 4183 // needed for built-in operators. Report them as well, but only once 4184 // as we have typically many built-in candidates. 4185 unsigned NoOperands = Cand->Conversions.size(); 4186 for (unsigned ArgIdx = 0; ArgIdx < NoOperands; ++ArgIdx) { 4187 const ImplicitConversionSequence &ICS = Cand->Conversions[ArgIdx]; 4188 if (ICS.ConversionKind != ImplicitConversionSequence::BadConversion || 4189 ICS.ConversionFunctionSet.empty()) 4190 continue; 4191 if (CXXConversionDecl *Func = dyn_cast<CXXConversionDecl>( 4192 Cand->Conversions[ArgIdx].ConversionFunctionSet[0])) { 4193 QualType FromTy = 4194 QualType( 4195 static_cast<Type*>(ICS.UserDefined.Before.FromTypePtr),0); 4196 Diag(OpLoc,diag::note_ambiguous_type_conversion) 4197 << FromTy << Func->getConversionType(); 4198 } 4199 for (unsigned j = 0; j < ICS.ConversionFunctionSet.size(); j++) { 4200 FunctionDecl *Func = 4201 Cand->Conversions[ArgIdx].ConversionFunctionSet[j]; 4202 Diag(Func->getLocation(),diag::err_ovl_candidate); 4203 } 4204 } 4205 Reported = true; 4206 } 4207 } 4208 } 4209} 4210 4211/// ResolveAddressOfOverloadedFunction - Try to resolve the address of 4212/// an overloaded function (C++ [over.over]), where @p From is an 4213/// expression with overloaded function type and @p ToType is the type 4214/// we're trying to resolve to. For example: 4215/// 4216/// @code 4217/// int f(double); 4218/// int f(int); 4219/// 4220/// int (*pfd)(double) = f; // selects f(double) 4221/// @endcode 4222/// 4223/// This routine returns the resulting FunctionDecl if it could be 4224/// resolved, and NULL otherwise. When @p Complain is true, this 4225/// routine will emit diagnostics if there is an error. 4226FunctionDecl * 4227Sema::ResolveAddressOfOverloadedFunction(Expr *From, QualType ToType, 4228 bool Complain) { 4229 QualType FunctionType = ToType; 4230 bool IsMember = false; 4231 if (const PointerType *ToTypePtr = ToType->getAs<PointerType>()) 4232 FunctionType = ToTypePtr->getPointeeType(); 4233 else if (const ReferenceType *ToTypeRef = ToType->getAs<ReferenceType>()) 4234 FunctionType = ToTypeRef->getPointeeType(); 4235 else if (const MemberPointerType *MemTypePtr = 4236 ToType->getAs<MemberPointerType>()) { 4237 FunctionType = MemTypePtr->getPointeeType(); 4238 IsMember = true; 4239 } 4240 4241 // We only look at pointers or references to functions. 4242 FunctionType = Context.getCanonicalType(FunctionType).getUnqualifiedType(); 4243 if (!FunctionType->isFunctionType()) 4244 return 0; 4245 4246 // Find the actual overloaded function declaration. 4247 OverloadedFunctionDecl *Ovl = 0; 4248 4249 // C++ [over.over]p1: 4250 // [...] [Note: any redundant set of parentheses surrounding the 4251 // overloaded function name is ignored (5.1). ] 4252 Expr *OvlExpr = From->IgnoreParens(); 4253 4254 // C++ [over.over]p1: 4255 // [...] The overloaded function name can be preceded by the & 4256 // operator. 4257 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(OvlExpr)) { 4258 if (UnOp->getOpcode() == UnaryOperator::AddrOf) 4259 OvlExpr = UnOp->getSubExpr()->IgnoreParens(); 4260 } 4261 4262 // Try to dig out the overloaded function. 4263 FunctionTemplateDecl *FunctionTemplate = 0; 4264 if (DeclRefExpr *DR = dyn_cast<DeclRefExpr>(OvlExpr)) { 4265 Ovl = dyn_cast<OverloadedFunctionDecl>(DR->getDecl()); 4266 FunctionTemplate = dyn_cast<FunctionTemplateDecl>(DR->getDecl()); 4267 } else if (MemberExpr *ME = dyn_cast<MemberExpr>(OvlExpr)) { 4268 Ovl = dyn_cast<OverloadedFunctionDecl>(ME->getMemberDecl()); 4269 FunctionTemplate = dyn_cast<FunctionTemplateDecl>(ME->getMemberDecl()); 4270 // FIXME: Explicit template arguments 4271 } 4272 // FIXME: TemplateIdRefExpr? 4273 4274 // If there's no overloaded function declaration or function template, 4275 // we're done. 4276 if (!Ovl && !FunctionTemplate) 4277 return 0; 4278 4279 OverloadIterator Fun; 4280 if (Ovl) 4281 Fun = Ovl; 4282 else 4283 Fun = FunctionTemplate; 4284 4285 // Look through all of the overloaded functions, searching for one 4286 // whose type matches exactly. 4287 llvm::SmallPtrSet<FunctionDecl *, 4> Matches; 4288 bool FoundNonTemplateFunction = false; 4289 for (OverloadIterator FunEnd; Fun != FunEnd; ++Fun) { 4290 // C++ [over.over]p3: 4291 // Non-member functions and static member functions match 4292 // targets of type "pointer-to-function" or "reference-to-function." 4293 // Nonstatic member functions match targets of 4294 // type "pointer-to-member-function." 4295 // Note that according to DR 247, the containing class does not matter. 4296 4297 if (FunctionTemplateDecl *FunctionTemplate 4298 = dyn_cast<FunctionTemplateDecl>(*Fun)) { 4299 if (CXXMethodDecl *Method 4300 = dyn_cast<CXXMethodDecl>(FunctionTemplate->getTemplatedDecl())) { 4301 // Skip non-static function templates when converting to pointer, and 4302 // static when converting to member pointer. 4303 if (Method->isStatic() == IsMember) 4304 continue; 4305 } else if (IsMember) 4306 continue; 4307 4308 // C++ [over.over]p2: 4309 // If the name is a function template, template argument deduction is 4310 // done (14.8.2.2), and if the argument deduction succeeds, the 4311 // resulting template argument list is used to generate a single 4312 // function template specialization, which is added to the set of 4313 // overloaded functions considered. 4314 // FIXME: We don't really want to build the specialization here, do we? 4315 FunctionDecl *Specialization = 0; 4316 TemplateDeductionInfo Info(Context); 4317 if (TemplateDeductionResult Result 4318 = DeduceTemplateArguments(FunctionTemplate, /*FIXME*/false, 4319 /*FIXME:*/0, /*FIXME:*/0, 4320 FunctionType, Specialization, Info)) { 4321 // FIXME: make a note of the failed deduction for diagnostics. 4322 (void)Result; 4323 } else { 4324 // FIXME: If the match isn't exact, shouldn't we just drop this as 4325 // a candidate? Find a testcase before changing the code. 4326 assert(FunctionType 4327 == Context.getCanonicalType(Specialization->getType())); 4328 Matches.insert( 4329 cast<FunctionDecl>(Specialization->getCanonicalDecl())); 4330 } 4331 } 4332 4333 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(*Fun)) { 4334 // Skip non-static functions when converting to pointer, and static 4335 // when converting to member pointer. 4336 if (Method->isStatic() == IsMember) 4337 continue; 4338 } else if (IsMember) 4339 continue; 4340 4341 if (FunctionDecl *FunDecl = dyn_cast<FunctionDecl>(*Fun)) { 4342 if (FunctionType == Context.getCanonicalType(FunDecl->getType())) { 4343 Matches.insert(cast<FunctionDecl>(Fun->getCanonicalDecl())); 4344 FoundNonTemplateFunction = true; 4345 } 4346 } 4347 } 4348 4349 // If there were 0 or 1 matches, we're done. 4350 if (Matches.empty()) 4351 return 0; 4352 else if (Matches.size() == 1) { 4353 FunctionDecl *Result = *Matches.begin(); 4354 MarkDeclarationReferenced(From->getLocStart(), Result); 4355 return Result; 4356 } 4357 4358 // C++ [over.over]p4: 4359 // If more than one function is selected, [...] 4360 typedef llvm::SmallPtrSet<FunctionDecl *, 4>::iterator MatchIter; 4361 if (!FoundNonTemplateFunction) { 4362 // [...] and any given function template specialization F1 is 4363 // eliminated if the set contains a second function template 4364 // specialization whose function template is more specialized 4365 // than the function template of F1 according to the partial 4366 // ordering rules of 14.5.5.2. 4367 4368 // The algorithm specified above is quadratic. We instead use a 4369 // two-pass algorithm (similar to the one used to identify the 4370 // best viable function in an overload set) that identifies the 4371 // best function template (if it exists). 4372 llvm::SmallVector<FunctionDecl *, 8> TemplateMatches(Matches.begin(), 4373 Matches.end()); 4374 FunctionDecl *Result = 4375 getMostSpecialized(TemplateMatches.data(), TemplateMatches.size(), 4376 TPOC_Other, From->getLocStart(), 4377 PDiag(), 4378 PDiag(diag::err_addr_ovl_ambiguous) 4379 << TemplateMatches[0]->getDeclName(), 4380 PDiag(diag::err_ovl_template_candidate)); 4381 MarkDeclarationReferenced(From->getLocStart(), Result); 4382 return Result; 4383 } 4384 4385 // [...] any function template specializations in the set are 4386 // eliminated if the set also contains a non-template function, [...] 4387 llvm::SmallVector<FunctionDecl *, 4> RemainingMatches; 4388 for (MatchIter M = Matches.begin(), MEnd = Matches.end(); M != MEnd; ++M) 4389 if ((*M)->getPrimaryTemplate() == 0) 4390 RemainingMatches.push_back(*M); 4391 4392 // [...] After such eliminations, if any, there shall remain exactly one 4393 // selected function. 4394 if (RemainingMatches.size() == 1) { 4395 FunctionDecl *Result = RemainingMatches.front(); 4396 MarkDeclarationReferenced(From->getLocStart(), Result); 4397 return Result; 4398 } 4399 4400 // FIXME: We should probably return the same thing that BestViableFunction 4401 // returns (even if we issue the diagnostics here). 4402 Diag(From->getLocStart(), diag::err_addr_ovl_ambiguous) 4403 << RemainingMatches[0]->getDeclName(); 4404 for (unsigned I = 0, N = RemainingMatches.size(); I != N; ++I) 4405 Diag(RemainingMatches[I]->getLocation(), diag::err_ovl_candidate); 4406 return 0; 4407} 4408 4409/// \brief Add a single candidate to the overload set. 4410static void AddOverloadedCallCandidate(Sema &S, 4411 AnyFunctionDecl Callee, 4412 bool &ArgumentDependentLookup, 4413 bool HasExplicitTemplateArgs, 4414 const TemplateArgument *ExplicitTemplateArgs, 4415 unsigned NumExplicitTemplateArgs, 4416 Expr **Args, unsigned NumArgs, 4417 OverloadCandidateSet &CandidateSet, 4418 bool PartialOverloading) { 4419 if (FunctionDecl *Func = dyn_cast<FunctionDecl>(Callee)) { 4420 assert(!HasExplicitTemplateArgs && "Explicit template arguments?"); 4421 S.AddOverloadCandidate(Func, Args, NumArgs, CandidateSet, false, false, 4422 PartialOverloading); 4423 4424 if (Func->getDeclContext()->isRecord() || 4425 Func->getDeclContext()->isFunctionOrMethod()) 4426 ArgumentDependentLookup = false; 4427 return; 4428 } 4429 4430 FunctionTemplateDecl *FuncTemplate = cast<FunctionTemplateDecl>(Callee); 4431 S.AddTemplateOverloadCandidate(FuncTemplate, HasExplicitTemplateArgs, 4432 ExplicitTemplateArgs, 4433 NumExplicitTemplateArgs, 4434 Args, NumArgs, CandidateSet); 4435 4436 if (FuncTemplate->getDeclContext()->isRecord()) 4437 ArgumentDependentLookup = false; 4438} 4439 4440/// \brief Add the overload candidates named by callee and/or found by argument 4441/// dependent lookup to the given overload set. 4442void Sema::AddOverloadedCallCandidates(NamedDecl *Callee, 4443 DeclarationName &UnqualifiedName, 4444 bool &ArgumentDependentLookup, 4445 bool HasExplicitTemplateArgs, 4446 const TemplateArgument *ExplicitTemplateArgs, 4447 unsigned NumExplicitTemplateArgs, 4448 Expr **Args, unsigned NumArgs, 4449 OverloadCandidateSet &CandidateSet, 4450 bool PartialOverloading) { 4451 // Add the functions denoted by Callee to the set of candidate 4452 // functions. While we're doing so, track whether argument-dependent 4453 // lookup still applies, per: 4454 // 4455 // C++0x [basic.lookup.argdep]p3: 4456 // Let X be the lookup set produced by unqualified lookup (3.4.1) 4457 // and let Y be the lookup set produced by argument dependent 4458 // lookup (defined as follows). If X contains 4459 // 4460 // -- a declaration of a class member, or 4461 // 4462 // -- a block-scope function declaration that is not a 4463 // using-declaration (FIXME: check for using declaration), or 4464 // 4465 // -- a declaration that is neither a function or a function 4466 // template 4467 // 4468 // then Y is empty. 4469 if (!Callee) { 4470 // Nothing to do. 4471 } else if (OverloadedFunctionDecl *Ovl 4472 = dyn_cast<OverloadedFunctionDecl>(Callee)) { 4473 for (OverloadedFunctionDecl::function_iterator Func = Ovl->function_begin(), 4474 FuncEnd = Ovl->function_end(); 4475 Func != FuncEnd; ++Func) 4476 AddOverloadedCallCandidate(*this, *Func, ArgumentDependentLookup, 4477 HasExplicitTemplateArgs, 4478 ExplicitTemplateArgs, NumExplicitTemplateArgs, 4479 Args, NumArgs, CandidateSet, 4480 PartialOverloading); 4481 } else if (isa<FunctionDecl>(Callee) || isa<FunctionTemplateDecl>(Callee)) 4482 AddOverloadedCallCandidate(*this, 4483 AnyFunctionDecl::getFromNamedDecl(Callee), 4484 ArgumentDependentLookup, 4485 HasExplicitTemplateArgs, 4486 ExplicitTemplateArgs, NumExplicitTemplateArgs, 4487 Args, NumArgs, CandidateSet, 4488 PartialOverloading); 4489 // FIXME: assert isa<FunctionDecl> || isa<FunctionTemplateDecl> rather than 4490 // checking dynamically. 4491 4492 if (Callee) 4493 UnqualifiedName = Callee->getDeclName(); 4494 4495 if (ArgumentDependentLookup) 4496 AddArgumentDependentLookupCandidates(UnqualifiedName, Args, NumArgs, 4497 HasExplicitTemplateArgs, 4498 ExplicitTemplateArgs, 4499 NumExplicitTemplateArgs, 4500 CandidateSet, 4501 PartialOverloading); 4502} 4503 4504/// ResolveOverloadedCallFn - Given the call expression that calls Fn 4505/// (which eventually refers to the declaration Func) and the call 4506/// arguments Args/NumArgs, attempt to resolve the function call down 4507/// to a specific function. If overload resolution succeeds, returns 4508/// the function declaration produced by overload 4509/// resolution. Otherwise, emits diagnostics, deletes all of the 4510/// arguments and Fn, and returns NULL. 4511FunctionDecl *Sema::ResolveOverloadedCallFn(Expr *Fn, NamedDecl *Callee, 4512 DeclarationName UnqualifiedName, 4513 bool HasExplicitTemplateArgs, 4514 const TemplateArgument *ExplicitTemplateArgs, 4515 unsigned NumExplicitTemplateArgs, 4516 SourceLocation LParenLoc, 4517 Expr **Args, unsigned NumArgs, 4518 SourceLocation *CommaLocs, 4519 SourceLocation RParenLoc, 4520 bool &ArgumentDependentLookup) { 4521 OverloadCandidateSet CandidateSet; 4522 4523 // Add the functions denoted by Callee to the set of candidate 4524 // functions. 4525 AddOverloadedCallCandidates(Callee, UnqualifiedName, ArgumentDependentLookup, 4526 HasExplicitTemplateArgs, ExplicitTemplateArgs, 4527 NumExplicitTemplateArgs, Args, NumArgs, 4528 CandidateSet); 4529 OverloadCandidateSet::iterator Best; 4530 switch (BestViableFunction(CandidateSet, Fn->getLocStart(), Best)) { 4531 case OR_Success: 4532 return Best->Function; 4533 4534 case OR_No_Viable_Function: 4535 Diag(Fn->getSourceRange().getBegin(), 4536 diag::err_ovl_no_viable_function_in_call) 4537 << UnqualifiedName << Fn->getSourceRange(); 4538 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4539 break; 4540 4541 case OR_Ambiguous: 4542 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_ambiguous_call) 4543 << UnqualifiedName << Fn->getSourceRange(); 4544 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4545 break; 4546 4547 case OR_Deleted: 4548 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_deleted_call) 4549 << Best->Function->isDeleted() 4550 << UnqualifiedName 4551 << Fn->getSourceRange(); 4552 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4553 break; 4554 } 4555 4556 // Overload resolution failed. Destroy all of the subexpressions and 4557 // return NULL. 4558 Fn->Destroy(Context); 4559 for (unsigned Arg = 0; Arg < NumArgs; ++Arg) 4560 Args[Arg]->Destroy(Context); 4561 return 0; 4562} 4563 4564/// \brief Create a unary operation that may resolve to an overloaded 4565/// operator. 4566/// 4567/// \param OpLoc The location of the operator itself (e.g., '*'). 4568/// 4569/// \param OpcIn The UnaryOperator::Opcode that describes this 4570/// operator. 4571/// 4572/// \param Functions The set of non-member functions that will be 4573/// considered by overload resolution. The caller needs to build this 4574/// set based on the context using, e.g., 4575/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 4576/// set should not contain any member functions; those will be added 4577/// by CreateOverloadedUnaryOp(). 4578/// 4579/// \param input The input argument. 4580Sema::OwningExprResult Sema::CreateOverloadedUnaryOp(SourceLocation OpLoc, 4581 unsigned OpcIn, 4582 FunctionSet &Functions, 4583 ExprArg input) { 4584 UnaryOperator::Opcode Opc = static_cast<UnaryOperator::Opcode>(OpcIn); 4585 Expr *Input = (Expr *)input.get(); 4586 4587 OverloadedOperatorKind Op = UnaryOperator::getOverloadedOperator(Opc); 4588 assert(Op != OO_None && "Invalid opcode for overloaded unary operator"); 4589 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 4590 4591 Expr *Args[2] = { Input, 0 }; 4592 unsigned NumArgs = 1; 4593 4594 // For post-increment and post-decrement, add the implicit '0' as 4595 // the second argument, so that we know this is a post-increment or 4596 // post-decrement. 4597 if (Opc == UnaryOperator::PostInc || Opc == UnaryOperator::PostDec) { 4598 llvm::APSInt Zero(Context.getTypeSize(Context.IntTy), false); 4599 Args[1] = new (Context) IntegerLiteral(Zero, Context.IntTy, 4600 SourceLocation()); 4601 NumArgs = 2; 4602 } 4603 4604 if (Input->isTypeDependent()) { 4605 OverloadedFunctionDecl *Overloads 4606 = OverloadedFunctionDecl::Create(Context, CurContext, OpName); 4607 for (FunctionSet::iterator Func = Functions.begin(), 4608 FuncEnd = Functions.end(); 4609 Func != FuncEnd; ++Func) 4610 Overloads->addOverload(*Func); 4611 4612 DeclRefExpr *Fn = new (Context) DeclRefExpr(Overloads, Context.OverloadTy, 4613 OpLoc, false, false); 4614 4615 input.release(); 4616 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 4617 &Args[0], NumArgs, 4618 Context.DependentTy, 4619 OpLoc)); 4620 } 4621 4622 // Build an empty overload set. 4623 OverloadCandidateSet CandidateSet; 4624 4625 // Add the candidates from the given function set. 4626 AddFunctionCandidates(Functions, &Args[0], NumArgs, CandidateSet, false); 4627 4628 // Add operator candidates that are member functions. 4629 AddMemberOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 4630 4631 // Add builtin operator candidates. 4632 AddBuiltinOperatorCandidates(Op, &Args[0], NumArgs, CandidateSet); 4633 4634 // Perform overload resolution. 4635 OverloadCandidateSet::iterator Best; 4636 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 4637 case OR_Success: { 4638 // We found a built-in operator or an overloaded operator. 4639 FunctionDecl *FnDecl = Best->Function; 4640 4641 if (FnDecl) { 4642 // We matched an overloaded operator. Build a call to that 4643 // operator. 4644 4645 // Convert the arguments. 4646 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 4647 if (PerformObjectArgumentInitialization(Input, Method)) 4648 return ExprError(); 4649 } else { 4650 // Convert the arguments. 4651 if (PerformCopyInitialization(Input, 4652 FnDecl->getParamDecl(0)->getType(), 4653 "passing")) 4654 return ExprError(); 4655 } 4656 4657 // Determine the result type 4658 QualType ResultTy = FnDecl->getResultType().getNonReferenceType(); 4659 4660 // Build the actual expression node. 4661 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 4662 SourceLocation()); 4663 UsualUnaryConversions(FnExpr); 4664 4665 input.release(); 4666 4667 ExprOwningPtr<CallExpr> TheCall(this, 4668 new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 4669 &Input, 1, ResultTy, OpLoc)); 4670 4671 if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall.get(), 4672 FnDecl)) 4673 return ExprError(); 4674 4675 return MaybeBindToTemporary(TheCall.release()); 4676 } else { 4677 // We matched a built-in operator. Convert the arguments, then 4678 // break out so that we will build the appropriate built-in 4679 // operator node. 4680 if (PerformImplicitConversion(Input, Best->BuiltinTypes.ParamTypes[0], 4681 Best->Conversions[0], "passing")) 4682 return ExprError(); 4683 4684 break; 4685 } 4686 } 4687 4688 case OR_No_Viable_Function: 4689 // No viable function; fall through to handling this as a 4690 // built-in operator, which will produce an error message for us. 4691 break; 4692 4693 case OR_Ambiguous: 4694 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 4695 << UnaryOperator::getOpcodeStr(Opc) 4696 << Input->getSourceRange(); 4697 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true, 4698 UnaryOperator::getOpcodeStr(Opc), OpLoc); 4699 return ExprError(); 4700 4701 case OR_Deleted: 4702 Diag(OpLoc, diag::err_ovl_deleted_oper) 4703 << Best->Function->isDeleted() 4704 << UnaryOperator::getOpcodeStr(Opc) 4705 << Input->getSourceRange(); 4706 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4707 return ExprError(); 4708 } 4709 4710 // Either we found no viable overloaded operator or we matched a 4711 // built-in operator. In either case, fall through to trying to 4712 // build a built-in operation. 4713 input.release(); 4714 return CreateBuiltinUnaryOp(OpLoc, Opc, Owned(Input)); 4715} 4716 4717/// \brief Create a binary operation that may resolve to an overloaded 4718/// operator. 4719/// 4720/// \param OpLoc The location of the operator itself (e.g., '+'). 4721/// 4722/// \param OpcIn The BinaryOperator::Opcode that describes this 4723/// operator. 4724/// 4725/// \param Functions The set of non-member functions that will be 4726/// considered by overload resolution. The caller needs to build this 4727/// set based on the context using, e.g., 4728/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 4729/// set should not contain any member functions; those will be added 4730/// by CreateOverloadedBinOp(). 4731/// 4732/// \param LHS Left-hand argument. 4733/// \param RHS Right-hand argument. 4734Sema::OwningExprResult 4735Sema::CreateOverloadedBinOp(SourceLocation OpLoc, 4736 unsigned OpcIn, 4737 FunctionSet &Functions, 4738 Expr *LHS, Expr *RHS) { 4739 Expr *Args[2] = { LHS, RHS }; 4740 LHS=RHS=0; //Please use only Args instead of LHS/RHS couple 4741 4742 BinaryOperator::Opcode Opc = static_cast<BinaryOperator::Opcode>(OpcIn); 4743 OverloadedOperatorKind Op = BinaryOperator::getOverloadedOperator(Opc); 4744 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 4745 4746 // If either side is type-dependent, create an appropriate dependent 4747 // expression. 4748 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 4749 // .* cannot be overloaded. 4750 if (Opc == BinaryOperator::PtrMemD) 4751 return Owned(new (Context) BinaryOperator(Args[0], Args[1], Opc, 4752 Context.DependentTy, OpLoc)); 4753 4754 OverloadedFunctionDecl *Overloads 4755 = OverloadedFunctionDecl::Create(Context, CurContext, OpName); 4756 for (FunctionSet::iterator Func = Functions.begin(), 4757 FuncEnd = Functions.end(); 4758 Func != FuncEnd; ++Func) 4759 Overloads->addOverload(*Func); 4760 4761 DeclRefExpr *Fn = new (Context) DeclRefExpr(Overloads, Context.OverloadTy, 4762 OpLoc, false, false); 4763 4764 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 4765 Args, 2, 4766 Context.DependentTy, 4767 OpLoc)); 4768 } 4769 4770 // If this is the .* operator, which is not overloadable, just 4771 // create a built-in binary operator. 4772 if (Opc == BinaryOperator::PtrMemD) 4773 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 4774 4775 // If this is one of the assignment operators, we only perform 4776 // overload resolution if the left-hand side is a class or 4777 // enumeration type (C++ [expr.ass]p3). 4778 if (Opc >= BinaryOperator::Assign && Opc <= BinaryOperator::OrAssign && 4779 !Args[0]->getType()->isOverloadableType()) 4780 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 4781 4782 // Build an empty overload set. 4783 OverloadCandidateSet CandidateSet; 4784 4785 // Add the candidates from the given function set. 4786 AddFunctionCandidates(Functions, Args, 2, CandidateSet, false); 4787 4788 // Add operator candidates that are member functions. 4789 AddMemberOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 4790 4791 // Add builtin operator candidates. 4792 AddBuiltinOperatorCandidates(Op, Args, 2, CandidateSet); 4793 4794 // Perform overload resolution. 4795 OverloadCandidateSet::iterator Best; 4796 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 4797 case OR_Success: { 4798 // We found a built-in operator or an overloaded operator. 4799 FunctionDecl *FnDecl = Best->Function; 4800 4801 if (FnDecl) { 4802 // We matched an overloaded operator. Build a call to that 4803 // operator. 4804 4805 // Convert the arguments. 4806 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 4807 if (PerformObjectArgumentInitialization(Args[0], Method) || 4808 PerformCopyInitialization(Args[1], FnDecl->getParamDecl(0)->getType(), 4809 "passing")) 4810 return ExprError(); 4811 } else { 4812 // Convert the arguments. 4813 if (PerformCopyInitialization(Args[0], FnDecl->getParamDecl(0)->getType(), 4814 "passing") || 4815 PerformCopyInitialization(Args[1], FnDecl->getParamDecl(1)->getType(), 4816 "passing")) 4817 return ExprError(); 4818 } 4819 4820 // Determine the result type 4821 QualType ResultTy 4822 = FnDecl->getType()->getAs<FunctionType>()->getResultType(); 4823 ResultTy = ResultTy.getNonReferenceType(); 4824 4825 // Build the actual expression node. 4826 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 4827 OpLoc); 4828 UsualUnaryConversions(FnExpr); 4829 4830 ExprOwningPtr<CXXOperatorCallExpr> 4831 TheCall(this, new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 4832 Args, 2, ResultTy, 4833 OpLoc)); 4834 4835 if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall.get(), 4836 FnDecl)) 4837 return ExprError(); 4838 4839 return MaybeBindToTemporary(TheCall.release()); 4840 } else { 4841 // We matched a built-in operator. Convert the arguments, then 4842 // break out so that we will build the appropriate built-in 4843 // operator node. 4844 if (PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 4845 Best->Conversions[0], "passing") || 4846 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 4847 Best->Conversions[1], "passing")) 4848 return ExprError(); 4849 4850 break; 4851 } 4852 } 4853 4854 case OR_No_Viable_Function: { 4855 // C++ [over.match.oper]p9: 4856 // If the operator is the operator , [...] and there are no 4857 // viable functions, then the operator is assumed to be the 4858 // built-in operator and interpreted according to clause 5. 4859 if (Opc == BinaryOperator::Comma) 4860 break; 4861 4862 // For class as left operand for assignment or compound assigment operator 4863 // do not fall through to handling in built-in, but report that no overloaded 4864 // assignment operator found 4865 OwningExprResult Result = ExprError(); 4866 if (Args[0]->getType()->isRecordType() && 4867 Opc >= BinaryOperator::Assign && Opc <= BinaryOperator::OrAssign) { 4868 Diag(OpLoc, diag::err_ovl_no_viable_oper) 4869 << BinaryOperator::getOpcodeStr(Opc) 4870 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 4871 } else { 4872 // No viable function; try to create a built-in operation, which will 4873 // produce an error. Then, show the non-viable candidates. 4874 Result = CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 4875 } 4876 assert(Result.isInvalid() && 4877 "C++ binary operator overloading is missing candidates!"); 4878 if (Result.isInvalid()) 4879 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false, 4880 BinaryOperator::getOpcodeStr(Opc), OpLoc); 4881 return move(Result); 4882 } 4883 4884 case OR_Ambiguous: 4885 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 4886 << BinaryOperator::getOpcodeStr(Opc) 4887 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 4888 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true, 4889 BinaryOperator::getOpcodeStr(Opc), OpLoc); 4890 return ExprError(); 4891 4892 case OR_Deleted: 4893 Diag(OpLoc, diag::err_ovl_deleted_oper) 4894 << Best->Function->isDeleted() 4895 << BinaryOperator::getOpcodeStr(Opc) 4896 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 4897 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 4898 return ExprError(); 4899 } 4900 4901 // We matched a built-in operator; build it. 4902 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 4903} 4904 4905/// BuildCallToMemberFunction - Build a call to a member 4906/// function. MemExpr is the expression that refers to the member 4907/// function (and includes the object parameter), Args/NumArgs are the 4908/// arguments to the function call (not including the object 4909/// parameter). The caller needs to validate that the member 4910/// expression refers to a member function or an overloaded member 4911/// function. 4912Sema::ExprResult 4913Sema::BuildCallToMemberFunction(Scope *S, Expr *MemExprE, 4914 SourceLocation LParenLoc, Expr **Args, 4915 unsigned NumArgs, SourceLocation *CommaLocs, 4916 SourceLocation RParenLoc) { 4917 // Dig out the member expression. This holds both the object 4918 // argument and the member function we're referring to. 4919 MemberExpr *MemExpr = 0; 4920 if (ParenExpr *ParenE = dyn_cast<ParenExpr>(MemExprE)) 4921 MemExpr = dyn_cast<MemberExpr>(ParenE->getSubExpr()); 4922 else 4923 MemExpr = dyn_cast<MemberExpr>(MemExprE); 4924 assert(MemExpr && "Building member call without member expression"); 4925 4926 // Extract the object argument. 4927 Expr *ObjectArg = MemExpr->getBase(); 4928 4929 CXXMethodDecl *Method = 0; 4930 if (isa<OverloadedFunctionDecl>(MemExpr->getMemberDecl()) || 4931 isa<FunctionTemplateDecl>(MemExpr->getMemberDecl())) { 4932 // Add overload candidates 4933 OverloadCandidateSet CandidateSet; 4934 DeclarationName DeclName = MemExpr->getMemberDecl()->getDeclName(); 4935 4936 for (OverloadIterator Func(MemExpr->getMemberDecl()), FuncEnd; 4937 Func != FuncEnd; ++Func) { 4938 if ((Method = dyn_cast<CXXMethodDecl>(*Func))) 4939 AddMethodCandidate(Method, ObjectArg, Args, NumArgs, CandidateSet, 4940 /*SuppressUserConversions=*/false); 4941 else 4942 AddMethodTemplateCandidate(cast<FunctionTemplateDecl>(*Func), 4943 MemExpr->hasExplicitTemplateArgumentList(), 4944 MemExpr->getTemplateArgs(), 4945 MemExpr->getNumTemplateArgs(), 4946 ObjectArg, Args, NumArgs, 4947 CandidateSet, 4948 /*SuppressUsedConversions=*/false); 4949 } 4950 4951 OverloadCandidateSet::iterator Best; 4952 switch (BestViableFunction(CandidateSet, MemExpr->getLocStart(), Best)) { 4953 case OR_Success: 4954 Method = cast<CXXMethodDecl>(Best->Function); 4955 break; 4956 4957 case OR_No_Viable_Function: 4958 Diag(MemExpr->getSourceRange().getBegin(), 4959 diag::err_ovl_no_viable_member_function_in_call) 4960 << DeclName << MemExprE->getSourceRange(); 4961 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4962 // FIXME: Leaking incoming expressions! 4963 return true; 4964 4965 case OR_Ambiguous: 4966 Diag(MemExpr->getSourceRange().getBegin(), 4967 diag::err_ovl_ambiguous_member_call) 4968 << DeclName << MemExprE->getSourceRange(); 4969 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4970 // FIXME: Leaking incoming expressions! 4971 return true; 4972 4973 case OR_Deleted: 4974 Diag(MemExpr->getSourceRange().getBegin(), 4975 diag::err_ovl_deleted_member_call) 4976 << Best->Function->isDeleted() 4977 << DeclName << MemExprE->getSourceRange(); 4978 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 4979 // FIXME: Leaking incoming expressions! 4980 return true; 4981 } 4982 4983 FixOverloadedFunctionReference(MemExpr, Method); 4984 } else { 4985 Method = dyn_cast<CXXMethodDecl>(MemExpr->getMemberDecl()); 4986 } 4987 4988 assert(Method && "Member call to something that isn't a method?"); 4989 ExprOwningPtr<CXXMemberCallExpr> 4990 TheCall(this, new (Context) CXXMemberCallExpr(Context, MemExpr, Args, 4991 NumArgs, 4992 Method->getResultType().getNonReferenceType(), 4993 RParenLoc)); 4994 4995 // Check for a valid return type. 4996 if (CheckCallReturnType(Method->getResultType(), MemExpr->getMemberLoc(), 4997 TheCall.get(), Method)) 4998 return true; 4999 5000 // Convert the object argument (for a non-static member function call). 5001 if (!Method->isStatic() && 5002 PerformObjectArgumentInitialization(ObjectArg, Method)) 5003 return true; 5004 MemExpr->setBase(ObjectArg); 5005 5006 // Convert the rest of the arguments 5007 const FunctionProtoType *Proto = cast<FunctionProtoType>(Method->getType()); 5008 if (ConvertArgumentsForCall(&*TheCall, MemExpr, Method, Proto, Args, NumArgs, 5009 RParenLoc)) 5010 return true; 5011 5012 if (CheckFunctionCall(Method, TheCall.get())) 5013 return true; 5014 5015 return MaybeBindToTemporary(TheCall.release()).release(); 5016} 5017 5018/// BuildCallToObjectOfClassType - Build a call to an object of class 5019/// type (C++ [over.call.object]), which can end up invoking an 5020/// overloaded function call operator (@c operator()) or performing a 5021/// user-defined conversion on the object argument. 5022Sema::ExprResult 5023Sema::BuildCallToObjectOfClassType(Scope *S, Expr *Object, 5024 SourceLocation LParenLoc, 5025 Expr **Args, unsigned NumArgs, 5026 SourceLocation *CommaLocs, 5027 SourceLocation RParenLoc) { 5028 assert(Object->getType()->isRecordType() && "Requires object type argument"); 5029 const RecordType *Record = Object->getType()->getAs<RecordType>(); 5030 5031 // C++ [over.call.object]p1: 5032 // If the primary-expression E in the function call syntax 5033 // evaluates to a class object of type "cv T", then the set of 5034 // candidate functions includes at least the function call 5035 // operators of T. The function call operators of T are obtained by 5036 // ordinary lookup of the name operator() in the context of 5037 // (E).operator(). 5038 OverloadCandidateSet CandidateSet; 5039 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Call); 5040 DeclContext::lookup_const_iterator Oper, OperEnd; 5041 for (llvm::tie(Oper, OperEnd) = Record->getDecl()->lookup(OpName); 5042 Oper != OperEnd; ++Oper) 5043 AddMethodCandidate(cast<CXXMethodDecl>(*Oper), Object, Args, NumArgs, 5044 CandidateSet, /*SuppressUserConversions=*/false); 5045 5046 // C++ [over.call.object]p2: 5047 // In addition, for each conversion function declared in T of the 5048 // form 5049 // 5050 // operator conversion-type-id () cv-qualifier; 5051 // 5052 // where cv-qualifier is the same cv-qualification as, or a 5053 // greater cv-qualification than, cv, and where conversion-type-id 5054 // denotes the type "pointer to function of (P1,...,Pn) returning 5055 // R", or the type "reference to pointer to function of 5056 // (P1,...,Pn) returning R", or the type "reference to function 5057 // of (P1,...,Pn) returning R", a surrogate call function [...] 5058 // is also considered as a candidate function. Similarly, 5059 // surrogate call functions are added to the set of candidate 5060 // functions for each conversion function declared in an 5061 // accessible base class provided the function is not hidden 5062 // within T by another intervening declaration. 5063 5064 if (!RequireCompleteType(SourceLocation(), Object->getType(), 0)) { 5065 // FIXME: Look in base classes for more conversion operators! 5066 OverloadedFunctionDecl *Conversions 5067 = cast<CXXRecordDecl>(Record->getDecl())->getConversionFunctions(); 5068 for (OverloadedFunctionDecl::function_iterator 5069 Func = Conversions->function_begin(), 5070 FuncEnd = Conversions->function_end(); 5071 Func != FuncEnd; ++Func) { 5072 CXXConversionDecl *Conv; 5073 FunctionTemplateDecl *ConvTemplate; 5074 GetFunctionAndTemplate(*Func, Conv, ConvTemplate); 5075 5076 // Skip over templated conversion functions; they aren't 5077 // surrogates. 5078 if (ConvTemplate) 5079 continue; 5080 5081 // Strip the reference type (if any) and then the pointer type (if 5082 // any) to get down to what might be a function type. 5083 QualType ConvType = Conv->getConversionType().getNonReferenceType(); 5084 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 5085 ConvType = ConvPtrType->getPointeeType(); 5086 5087 if (const FunctionProtoType *Proto = ConvType->getAs<FunctionProtoType>()) 5088 AddSurrogateCandidate(Conv, Proto, Object, Args, NumArgs, CandidateSet); 5089 } 5090 } 5091 5092 // Perform overload resolution. 5093 OverloadCandidateSet::iterator Best; 5094 switch (BestViableFunction(CandidateSet, Object->getLocStart(), Best)) { 5095 case OR_Success: 5096 // Overload resolution succeeded; we'll build the appropriate call 5097 // below. 5098 break; 5099 5100 case OR_No_Viable_Function: 5101 Diag(Object->getSourceRange().getBegin(), 5102 diag::err_ovl_no_viable_object_call) 5103 << Object->getType() << Object->getSourceRange(); 5104 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 5105 break; 5106 5107 case OR_Ambiguous: 5108 Diag(Object->getSourceRange().getBegin(), 5109 diag::err_ovl_ambiguous_object_call) 5110 << Object->getType() << Object->getSourceRange(); 5111 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 5112 break; 5113 5114 case OR_Deleted: 5115 Diag(Object->getSourceRange().getBegin(), 5116 diag::err_ovl_deleted_object_call) 5117 << Best->Function->isDeleted() 5118 << Object->getType() << Object->getSourceRange(); 5119 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 5120 break; 5121 } 5122 5123 if (Best == CandidateSet.end()) { 5124 // We had an error; delete all of the subexpressions and return 5125 // the error. 5126 Object->Destroy(Context); 5127 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 5128 Args[ArgIdx]->Destroy(Context); 5129 return true; 5130 } 5131 5132 if (Best->Function == 0) { 5133 // Since there is no function declaration, this is one of the 5134 // surrogate candidates. Dig out the conversion function. 5135 CXXConversionDecl *Conv 5136 = cast<CXXConversionDecl>( 5137 Best->Conversions[0].UserDefined.ConversionFunction); 5138 5139 // We selected one of the surrogate functions that converts the 5140 // object parameter to a function pointer. Perform the conversion 5141 // on the object argument, then let ActOnCallExpr finish the job. 5142 5143 // Create an implicit member expr to refer to the conversion operator. 5144 // and then call it. 5145 CXXMemberCallExpr *CE = 5146 BuildCXXMemberCallExpr(Object, Conv); 5147 5148 return ActOnCallExpr(S, ExprArg(*this, CE), LParenLoc, 5149 MultiExprArg(*this, (ExprTy**)Args, NumArgs), 5150 CommaLocs, RParenLoc).release(); 5151 } 5152 5153 // We found an overloaded operator(). Build a CXXOperatorCallExpr 5154 // that calls this method, using Object for the implicit object 5155 // parameter and passing along the remaining arguments. 5156 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 5157 const FunctionProtoType *Proto = Method->getType()->getAs<FunctionProtoType>(); 5158 5159 unsigned NumArgsInProto = Proto->getNumArgs(); 5160 unsigned NumArgsToCheck = NumArgs; 5161 5162 // Build the full argument list for the method call (the 5163 // implicit object parameter is placed at the beginning of the 5164 // list). 5165 Expr **MethodArgs; 5166 if (NumArgs < NumArgsInProto) { 5167 NumArgsToCheck = NumArgsInProto; 5168 MethodArgs = new Expr*[NumArgsInProto + 1]; 5169 } else { 5170 MethodArgs = new Expr*[NumArgs + 1]; 5171 } 5172 MethodArgs[0] = Object; 5173 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 5174 MethodArgs[ArgIdx + 1] = Args[ArgIdx]; 5175 5176 Expr *NewFn = new (Context) DeclRefExpr(Method, Method->getType(), 5177 SourceLocation()); 5178 UsualUnaryConversions(NewFn); 5179 5180 // Once we've built TheCall, all of the expressions are properly 5181 // owned. 5182 QualType ResultTy = Method->getResultType().getNonReferenceType(); 5183 ExprOwningPtr<CXXOperatorCallExpr> 5184 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Call, NewFn, 5185 MethodArgs, NumArgs + 1, 5186 ResultTy, RParenLoc)); 5187 delete [] MethodArgs; 5188 5189 if (CheckCallReturnType(Method->getResultType(), LParenLoc, TheCall.get(), 5190 Method)) 5191 return true; 5192 5193 // We may have default arguments. If so, we need to allocate more 5194 // slots in the call for them. 5195 if (NumArgs < NumArgsInProto) 5196 TheCall->setNumArgs(Context, NumArgsInProto + 1); 5197 else if (NumArgs > NumArgsInProto) 5198 NumArgsToCheck = NumArgsInProto; 5199 5200 bool IsError = false; 5201 5202 // Initialize the implicit object parameter. 5203 IsError |= PerformObjectArgumentInitialization(Object, Method); 5204 TheCall->setArg(0, Object); 5205 5206 5207 // Check the argument types. 5208 for (unsigned i = 0; i != NumArgsToCheck; i++) { 5209 Expr *Arg; 5210 if (i < NumArgs) { 5211 Arg = Args[i]; 5212 5213 // Pass the argument. 5214 QualType ProtoArgType = Proto->getArgType(i); 5215 IsError |= PerformCopyInitialization(Arg, ProtoArgType, "passing"); 5216 } else { 5217 Arg = CXXDefaultArgExpr::Create(Context, Method->getParamDecl(i)); 5218 } 5219 5220 TheCall->setArg(i + 1, Arg); 5221 } 5222 5223 // If this is a variadic call, handle args passed through "...". 5224 if (Proto->isVariadic()) { 5225 // Promote the arguments (C99 6.5.2.2p7). 5226 for (unsigned i = NumArgsInProto; i != NumArgs; i++) { 5227 Expr *Arg = Args[i]; 5228 IsError |= DefaultVariadicArgumentPromotion(Arg, VariadicMethod); 5229 TheCall->setArg(i + 1, Arg); 5230 } 5231 } 5232 5233 if (IsError) return true; 5234 5235 if (CheckFunctionCall(Method, TheCall.get())) 5236 return true; 5237 5238 return MaybeBindToTemporary(TheCall.release()).release(); 5239} 5240 5241/// BuildOverloadedArrowExpr - Build a call to an overloaded @c operator-> 5242/// (if one exists), where @c Base is an expression of class type and 5243/// @c Member is the name of the member we're trying to find. 5244Sema::OwningExprResult 5245Sema::BuildOverloadedArrowExpr(Scope *S, ExprArg BaseIn, SourceLocation OpLoc) { 5246 Expr *Base = static_cast<Expr *>(BaseIn.get()); 5247 assert(Base->getType()->isRecordType() && "left-hand side must have class type"); 5248 5249 // C++ [over.ref]p1: 5250 // 5251 // [...] An expression x->m is interpreted as (x.operator->())->m 5252 // for a class object x of type T if T::operator->() exists and if 5253 // the operator is selected as the best match function by the 5254 // overload resolution mechanism (13.3). 5255 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Arrow); 5256 OverloadCandidateSet CandidateSet; 5257 const RecordType *BaseRecord = Base->getType()->getAs<RecordType>(); 5258 5259 LookupResult R; 5260 LookupQualifiedName(R, BaseRecord->getDecl(), OpName, LookupOrdinaryName); 5261 5262 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 5263 Oper != OperEnd; ++Oper) 5264 AddMethodCandidate(cast<CXXMethodDecl>(*Oper), Base, 0, 0, CandidateSet, 5265 /*SuppressUserConversions=*/false); 5266 5267 // Perform overload resolution. 5268 OverloadCandidateSet::iterator Best; 5269 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 5270 case OR_Success: 5271 // Overload resolution succeeded; we'll build the call below. 5272 break; 5273 5274 case OR_No_Viable_Function: 5275 if (CandidateSet.empty()) 5276 Diag(OpLoc, diag::err_typecheck_member_reference_arrow) 5277 << Base->getType() << Base->getSourceRange(); 5278 else 5279 Diag(OpLoc, diag::err_ovl_no_viable_oper) 5280 << "operator->" << Base->getSourceRange(); 5281 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/false); 5282 return ExprError(); 5283 5284 case OR_Ambiguous: 5285 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 5286 << "->" << Base->getSourceRange(); 5287 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 5288 return ExprError(); 5289 5290 case OR_Deleted: 5291 Diag(OpLoc, diag::err_ovl_deleted_oper) 5292 << Best->Function->isDeleted() 5293 << "->" << Base->getSourceRange(); 5294 PrintOverloadCandidates(CandidateSet, /*OnlyViable=*/true); 5295 return ExprError(); 5296 } 5297 5298 // Convert the object parameter. 5299 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 5300 if (PerformObjectArgumentInitialization(Base, Method)) 5301 return ExprError(); 5302 5303 // No concerns about early exits now. 5304 BaseIn.release(); 5305 5306 // Build the operator call. 5307 Expr *FnExpr = new (Context) DeclRefExpr(Method, Method->getType(), 5308 SourceLocation()); 5309 UsualUnaryConversions(FnExpr); 5310 5311 QualType ResultTy = Method->getResultType().getNonReferenceType(); 5312 ExprOwningPtr<CXXOperatorCallExpr> 5313 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Arrow, FnExpr, 5314 &Base, 1, ResultTy, OpLoc)); 5315 5316 if (CheckCallReturnType(Method->getResultType(), OpLoc, TheCall.get(), 5317 Method)) 5318 return ExprError(); 5319 return move(TheCall); 5320} 5321 5322/// FixOverloadedFunctionReference - E is an expression that refers to 5323/// a C++ overloaded function (possibly with some parentheses and 5324/// perhaps a '&' around it). We have resolved the overloaded function 5325/// to the function declaration Fn, so patch up the expression E to 5326/// refer (possibly indirectly) to Fn. 5327/// Returns true if the function reference used an explicit address-of operator. 5328bool Sema::FixOverloadedFunctionReference(Expr *E, FunctionDecl *Fn) { 5329 if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) { 5330 bool ret = FixOverloadedFunctionReference(PE->getSubExpr(), Fn); 5331 E->setType(PE->getSubExpr()->getType()); 5332 return ret; 5333 } else if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(E)) { 5334 assert(UnOp->getOpcode() == UnaryOperator::AddrOf && 5335 "Can only take the address of an overloaded function"); 5336 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 5337 if (Method->isStatic()) { 5338 // Do nothing: static member functions aren't any different 5339 // from non-member functions. 5340 } else if (QualifiedDeclRefExpr *DRE 5341 = dyn_cast<QualifiedDeclRefExpr>(UnOp->getSubExpr())) { 5342 // We have taken the address of a pointer to member 5343 // function. Perform the computation here so that we get the 5344 // appropriate pointer to member type. 5345 DRE->setDecl(Fn); 5346 DRE->setType(Fn->getType()); 5347 QualType ClassType 5348 = Context.getTypeDeclType(cast<RecordDecl>(Method->getDeclContext())); 5349 E->setType(Context.getMemberPointerType(Fn->getType(), 5350 ClassType.getTypePtr())); 5351 return true; 5352 } 5353 } 5354 FixOverloadedFunctionReference(UnOp->getSubExpr(), Fn); 5355 E->setType(Context.getPointerType(UnOp->getSubExpr()->getType())); 5356 return true; 5357 } else if (DeclRefExpr *DR = dyn_cast<DeclRefExpr>(E)) { 5358 assert((isa<OverloadedFunctionDecl>(DR->getDecl()) || 5359 isa<FunctionTemplateDecl>(DR->getDecl())) && 5360 "Expected overloaded function or function template"); 5361 DR->setDecl(Fn); 5362 E->setType(Fn->getType()); 5363 } else if (MemberExpr *MemExpr = dyn_cast<MemberExpr>(E)) { 5364 MemExpr->setMemberDecl(Fn); 5365 E->setType(Fn->getType()); 5366 } else { 5367 assert(false && "Invalid reference to overloaded function"); 5368 } 5369 return false; 5370} 5371 5372} // end namespace clang 5373